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Stars/Sun/Solar binary

A solar binary of the Sun and Jupiter may serve to establish an upper limit for interstellar cometary capture. The basic problem even with a passage through a molecular cloud of some 10 million years is the low relative velocity (~0.5 km s-1) required between the solar system and the cometary medium. Some of the captured bodies may localize in the Oort cloud, while others localize near the Sun or Jupiter.

As stars often occur as binaries or multiple star systems, it is likely that the Sun may have been a member of a binary system or even a multiple star system at some time in the past.

Solar twins
Solar twins have the following qualities:

 * Temperature within 50 K Solar (roughly 5720 to 5830 K)
 * Metallicity of 89—112% (± 0.05 dex) Solar, meaning the star's proplyd would have had almost exactly the same amount of dust for planetary formation
 * No stellar companion, because the Sun itself is solitary
 * An age within 1 billion years Solar (roughly 3.5 to 5.6 Ga)

A solar twin is more similar to the Sun than a solar analog.

Solar analogs
Solar analogs "are photometrically similar to the Sun, having the following qualities:"

 * Temperature within 500 K Solar (roughly 5200 to 6300 K)
 * Metallicity of 50—200% (± 0.3 dex) Solar, meaning the star's protoplanetary disk would have had similar amounts of dust from which planets could form
 * No close companion (orbital period of ten days or less), as such a companion stimulates stellar activity

Solar analog stars would have an effective surface temperature of ~5800 K.

Solar analogs not meeting the stricter solar twin criteria include, within 50 light years and in order of increasing distance:

Solar types
A solar-type star is less similar to the Sun than a solar analog star.

Solar-type stars "are main-sequence stars with a B-V color between 0.48 and 0.80, the Sun having a B-V color of 0.65. Alternatively, a definition based on spectral type can be used, such as F8 V through K2 V, which would correspond to B-V color of 0.50 to 1.00. This definition fits approximately 10% of stars".

"Solar-type stars show highly correlated behavior between their rotation rates and their chromospheric activity (e.g. Calcium H & K line emission) and coronal activity (e.g. X-ray emission). As solar-type stars spin-down during their main-sequence lifetimes due to magnetic braking, these correlations allow rough ages to be derived.

The following table shows a sample of solar-type stars within 50 light years that nearly satisfy the criteria for solar analogs, based on current measurements.

Solar binary theory
Uranus is named after the ancient Greek deity of the sky Uranus, the father of Cronus (Saturn) and grandfather of Zeus (Jupiter). Though it is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit.

Binary stars
Def. "[t]wo stars that appear to be one when seen with the naked eye, either because they orbit one another (binary stars) or happen to be in the same line of sight even though they are separated by a great distance> is called a double star.

Def. "[a] star that appears as a double due to an optical illusion; in reality, the stars may be far apart from each other> is called an optical double.

Def. two stars which form a stellar system, such that they orbit the point of equilibrium of their gravitational fields is called a double star.

Def. a stellar system that has two stars orbiting around each other is called a binary star.

A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, ... or secondary. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known.

Def. a binary star whose components can be visually resolved is called a visual binary.

Astrometric binaries
Astrometric binaries are relatively nearby stars which can be seen to wobble around a point in space, with no visible companion. The same mathematics used for ordinary binaries can be applied to infer the mass of the missing companion. The companion could be very dim, so that it is currently undetectable or masked by the glare of its primary, or it could be an object that emits little or no electromagnetic radiation.

The visible star's position is carefully measured and detected to vary, due to the gravitational influence from its counterpart. The position of the star is repeatedly measured relative to more distant stars, and then checked for periodic shifts in position. Typically this type of measurement can only be performed on nearby stars, such as those within 10 parsecs. Nearby stars often have a relatively high proper motion, so astrometric binaries will appear to follow a sinusoidal path across the sky.

Spectroscopic binaries
Sometimes, the only evidence of a binary star comes from the Doppler effect on its emitted light. In these cases, the binary consists of a pair of stars where the spectral lines in the light emitted from each star shifts first toward the blue, then toward the red, as each moves first toward us, and then away from us, during its motion about their common center of mass, with the period of their common orbit.

In these systems, the separation between the stars is usually very small, and the orbital velocity very high. Unless the plane of the orbit happens to be perpendicular to the line of sight, the orbital velocities will have components in the line of sight and the observed radial velocity of the system will vary periodically. Since radial velocity can be measured with a spectrometer by observing the Doppler shift of the stars' spectral lines, the binaries detected in this manner are known as spectroscopic binaries. Most of these cannot be resolved as a visual binary, even with telescopes of the highest existing resolving power.

Eclipsing binaries
An eclipsing binary star is a binary star in which the orbit plane of the two stars lies so nearly in the line of sight of the observer that the components undergo mutual eclipses. In the case where the binary is also a spectroscopic binary and the parallax of the system is known, the binary is quite valuable for stellar analysis. Algol is the best-known example of an eclipsing binary.

Eclipsing binary with matter transfer
Matter may transfer from one star to another through a process known as Roche Lobe overflow (RLOF) through an accretion disc. The mathematical point through which this transfer happens is called the first Lagrangian point. It is not uncommon that the accretion disc is the brightest (and thus sometimes the only visible) element of a binary star.

Detached binaries
For detached binaries each component is within its Roche lobe, i.e. the area where the gravitational pull of the star itself is larger than that of the other component. The stars have no major effect on each other, and essentially evolve separately. Most binaries belong to this class.

Semidetached binaries
A semidetached binary has “one of the components [filling] the binary star's Roche lobe and the other does not. Gas from the surface of the Roche-lobe-filling component (donor) is transferred to the other, accreting star. The mass transfer dominates the evolution of the system. In many cases, the inflowing gas forms an accretion disc around the accretor.

Contact binaries
In a contact binary both components fill their Roche lobes; i.e., they “are so close that they touch each other or have merged to share their gaseous envelopes.

When stars share an envelope the pair may be called an overcontact binary. “As the friction of the envelope brakes the orbital motion, the stars may eventually merge. A contact binary is a stable configuration [where the two stars touch,] with a typical lifetime of millions to billions of years. Almost all known contact binary systems are eclipsing binaries

Common envelope binaries
A common envelope (CE) binary refers to a short-lived (months to years) phase in the evolution of a binary star in which the largest of the two stars (the donor star) has initiated unstable mass transfer to its companion star. This [may become a run-away process in which] the [donor star’s] envelope [expands to] engulf the companion star. ... The [loss] of orbital energy [may] heat up and expand the envelope. The whole common-envelope phase ends when either the envelope is expelled into space, or the two objects inside the envelope merge and no more energy is available to expand or even expel the envelope. This phase of the shrinking of the orbit inside the common envelope is known as a spiral-in.

Chaos assisted capture
In a mechanism of chaos assisted capture (CAC), particles such as comets or those of sizes in the range of the irregular moons of Jupiter become entangled in chaotic layers which temporarily “extend the lifetimes of [these] particles within the Hill sphere, thereby providing the breathing space necessary for relatively weak dissipative forces (eg gas-drag) to effect permanent capture.” These objects of the Sun-Jupiter binary system may localize near Jupiter and become satellites, specifically the irregular moons.

Solar antapexes
In 1917 the solar antapex has an equatorial location of right ascension (RA) 6h declination (Dec) -34°.

Star fission
"Zero-age contact must be a consequence of star fission under critical angular momentum." When the angular momentum is too large, the star brakes into a detached binary. When the angular momentum is too small, the star remains as a single star. BH Centauri and V1010 Ophiuchi have zero-age radii and are zero-age contact systems. BH Centauri is an overcontact system.

Fragmentation of the molecular cloud during the formation of protostars is an acceptable explanation for the formation of a binary or multiple star system.

With respect to low-mass star formation, "fragmentation to form a binary star [may be] most simply achieved if collapse is initiated by an external impulse." "On its own, [the] process under which a dense molecular cloud core can collapse to form a binary, or multiple, star system would produce wide binaries". "[C]lose binaries [may be] formed because of mutual interactions between the protostellar discs surrounding the various fragments." "[T]he most likely collision which has an effect on the core is the one for which [the velocity change imparted by the impulse,] Δv ~ cs [(the internal sound speed),] induced by a clump of mass ~0.1Mʘ." "[T]he impulsive collapse of the cloud cores [requires] that they are not primarily magnetically supported in their central regions."

Electromagnetics
Consider an object of mass (m = 0.1M⊙) passing through the heliosphere of the Sun at a velocity of 20 km s-1 from a galactic location originally outside the heliosphere. There are no other large objects in orbit around the Sun at the time of this object's entry. Jupiter, Saturn, Uranus, and Neptune are not present.

The object has a surface negative charge of 0.2Q⊙ and an intrinsic magnetic field of 100 Gauss (G) directed vertically. A current of 5 e- per second is following along magnetic field lines toward the Sun from the object. A comparable number of protons are following magnetic field lines from the Sun to the object.

At t0 the object is at 1,000 AU. Its RA is 14h 30m Dec +46° 30'.

Let the Sun have a magnetic field of 1 G directed vertically. The charge on the Sun (Q⊙) is -3 x 1027 e.s.u.

Electrostatics
Coulomb's law states that the electrostatic force $$F_q$$ experienced by a charge, $$0.2Q_{\odot}$$ at position $$r_q$$, in the vicinity of another charge, $$Q_{\odot}$$ at position $$r_Q$$, in vacuum is equal to:

 * $$F_q = {0.2Q^2_{\odot}\over4\pi\varepsilon_0}{1\over {r^2}},$$

where $$\varepsilon_0$$ is the electric constant or the permittivity of free space and $$r$$ is the distance between the two charges and the constant $$\varepsilon_0$$ is in SI units of C2 m−2 N−1, where C is Coulombs.

ε0 ≈ 8.854 x 10-12 C2 m−2 N−1, or

ε0 ≈ 8.854 x 10-12 C2 10-6 km−2 N−1, then

ε0 ≈ 8.854 x 10-18 C2 km−2 N−1.

1 e.s.u. ≈ 3.34 x 10-10 C.

 * $$F_q = \frac{0.2}{4\pi} \frac{[(-3 \times 10^{27} e.s.u.) (3.34 \times 10^{-10} C/e.s.u.)]^2}{(8.854 \times 10^{-18} C^2 km^{-2} N^{-1}) [(1.5 \times 10^8) 10^3 km]^2}, $$

 * $$F_q = \frac{0.2 (-3)^2 (3.34)^2}{4\pi (8.854) (1.5)^2} \frac{(10^{27} \times 10^{-10})^2}{10^{-18} (10^8 \times 10^3)^2} \frac{[(e.s.u.) (C/e.s.u.)]^2}{C^2 km^{-2} N^{-1} km^2}, $$

 * $$F_q = 8.02 \times 10^{28} N.$$

Each of the constants used are approximates so Fq ≈ 8.02 x 1028 N.

Statuses
“The ... Larmor radius ... is the radius of the circular motion of a charged particle in the presence of a uniform magnetic field. “[F]or a particle of energy E in EeV and charge Z in a magnetic field B in µG [the Larmor radius (RL)] is roughly”

 * $$R_L = 1 kpc \frac{E}{Z B}$$

where
 * $$R_L \ $$ is the Larmor radius,
 * $$E\ $$ is the energy of the particle in EeV
 * $$Z \ $$ is the charge of the particle, and
 * $$B \ $$ is the constant magnetic field.

Or,

 * $$R_{Lm} = \frac{m v_{\perp}}{|q_m| B_{\odot}}$$

 * $$R_{L\odot} = \frac{M_{\odot} (-v_{\perp})}{|q_{\odot}| B_m}$$

where
 * $$R_L \ $$ is the Lamor or gyroradius,
 * $$m \ $$ is the mass of the charged particle,
 * $$v_{\perp}$$ is the velocity component perpendicular to the direction of the magnetic field,
 * $$q_m \ $$ is the charge of the particle, and
 * $$B_{\odot} \ $$ is the constant magnetic field for the Sun.

Larmor radii
For the object, as deflected by the Sun,

 * $$1G(Gauss) = \frac{1T(Tesla)}{10,000} = \frac{1Ns}{10^4 C 10^{-3} km} = \frac{1kg 10^{-3} km s^{-2} s}{10^4 C 10^{-3} km},$$

 * $$1G = \frac{1 kg}{10^4 C s}.$$

 * $$R_{Lm} = \frac{(0.1)(2 \times 10^{30} kg)(20 km/s)}{(0.2)(3 \times 10^{27} e.s.u.)(3.34 \times 10^{-10} C/e.s.u.) (1kg/(10^4 C s))},$$

 * $$R_{Lm} = \frac{(0.1)(2)(20)}{(0.2)(3)(3.34)(1)} \frac{10^{30} \times 10^4}{10^{27} \times 10^{-10}} \frac{kg km C s}{(e.s.u.)(C/e.s.u.)kg s},$$

 * $$R_{Lm} = 2 \times 10^{17} km.$$

Or,

 * $$R_{Lm} = 1.33 \times 10^9 AU.$$

For the Sun, as deflected by the object,

 * $$R_{L\odot} = \frac{(2 \times 10^{30} kg) (20 km/s)}{(3 \times 10^{27} e.s.u.) (3.34 \times 10^{-10} C/e.s.u.) (100 kg/(10^4 C s))},$$

 * $$R_{L\odot} = \frac{(2)(20)}{(3)(3.34)(100)} \frac{10^{30} \times 10^4}{10^{27} \times 10^{-10}} \frac{kg km C s}{(e.s.u.)(C/e.s.u.) kg s},$$

 * $$R_{L\odot} = 3.99 \times 10^{15} km.$$

Or,

 * $$R_{L\odot} = 2.66 \times 10^7 AU.$$

Electric orbits
In order for the object to have an orbit around the Sun, its approach velocity of 20 km/s must be reduced to below the Sun's escape velocity of 1.33 km/s.

The electrostatic force is the major available force of repulsion to slow down the object. As it continues to travel closer to the Sun, the forces increase. But, an estimate can be calculated of how much time is required to reduce the object's velocity to below the Sun's escape velocity.

 * $$v_1 = 20 km/s - (F_q/m)t < 1.33 km/s.$$

 * $$20 km/s < 1.33 km/s + (F_q/m)t,$$

 * $$(F_q/m)t > 20 km/s - 1.33 km/s,$$

 * $$t > \frac{20 km/s - 1.33 km/s}{F_q/m},$$

 * $$t > \frac{20 km/s - 1.33 km/s}{(8.02 \times 10^{28} kg 10^{-3}km/s^2)/((0.1)(2 \times 10^{30} kg))},$$

 * $$t > \frac{20 - 1.33}{8.02/((0.1)(2))} \frac{10^{30}}{10^{28} \times 10^{-3}} \frac{(km/s)kg}{kg (km/s^2)},$$

 * $$t > 4.66 \times 10^4 s.$$

Or,

 * $$t > 12.9 h.$$

Weak forces
"Some of the oddly skewed orbits of many alien worlds may be due to the twin stars they are often found circling [...] many of the exoplanets astronomers have discovered in the past two decades or so have mysteriously skewed orbits. They may be eccentric — that is, oval-shaped. They could also be inclined — tilted at an angle from the equators of their stars. One potential explanation for these skewed orbits might be the gravitational influence of a companion star near the host stars of those exoplanets. [...] most stars form in binary pairs, with both stars orbiting each other. In fact, there are many three-star systems as well, and even some that harbor up to seven stars."

For a solitary star, "the orbits of most planets are nearly circular, orbiting [their star']s equator."

X-rays
According to SIMBAD, Vega (alpha Lyrae) (delta Sct type variable) is an X-ray source in the first Einstein catalog (1E) and an ultraviolet source from the CEL, EUVE, and TD1 catalogs. It has not been detected as a gamma-ray source.

At one time (1932), Vega was listed as a double star. Also in 1963, Vega is listed as a visual double star. Again in 1983, it was listed as a double star. This was repeated in 1994. It is still listed as a double star in 1996. The update in 2001 also lists it. The star with Vega is 56.41 arcsec away and is designated as BD+38 3238D of unknown spectral class. That these two stars are undifferentiated between double star or binary star for some 70 years at only 25 lyrs away is remarkable.

Vega
The X-ray "counts observed from [...] Vega in the HRI are very likely to be due entirely to UV contamination from the photospheric emission, and hence the X-ray luminosities for [...] Vega [...] should be replaced by upper limits at least one order of magnitude lower, i.e., log LX, Vega < 26.6 [...] Thus the HRI observation of Vega is completely consistent with the upper limit obtained in the IPC, and the only remaining inconsistency concerning the X-ray emission from Vega is the rocket experiment by Topka et al. (1979), who report a detection of Vega in a 5 s pointing yielding 7 counts; however, in our opinion these authors do not convincingly rule out the possibility of UV contamination. Note in this context that the IPC's used for Topka et al.s' (1979) rocket flight and for the Einstein Observatory were not identical."

"Many types of main sequence stars emit in the X-ray portion of the spectra. In massive stars, strong stellar winds ripping through the extended atmosphere of the star create X-ray photons. On lower mass stars, magnetic fields twisting through the photosphere heat it sufficiently to produce X-rays. But between these two mechanisms, in the late B to mid A classes of stars, neither of these mechanisms should be sufficient to produce X-rays. Yet when X-ray telescopes examined these stars, many were found to produce X-rays just the same."

"The first exploration into the X-ray emission of this class of stars was the Einstein Observatory, launched in 1978 and deorbited in 1982. While the telescoped confirmed that these B and A stars had significantly less X-ray emission overall, seven of the 35 A type stars still had some emission. Four of these were confirmed as being in binary systems in which the secondary stars could be the source of the emission, leaving three of seven with unaccounted for X-rays."

"The German ROSAT satellite found similar results, detecting 232 X-ray stars in this range. Studies explored connections with irregularities in the spectra of these stars and rotational velocities, but found no correlation with either. The suspicion was that these stars simply hid undetected, lower mass companions."

Either "the main star truly is the source, or there are even more elusive, sub-arcsecond binaries skewing the data."

On July 27, 1977, at 05:41:48.1 UTC, an Aerobee 350 or boosted Black Brant launched from White Sands Missile Range using Vega as a reference by its star tracker to update its position while maneuvering between X-ray targets automatically observed Vega with its X-ray telescope for 4.8 s.

The quantity of detected photons (7) in the band 0.2-0.80 keV corresponds to an X-ray luminosity LX ≈ 3 x 1028 erg s-1.

"The ANS 3 σ upper limit for Vega (2.5 x 1028 ergs s-1) is only slightly lower than our flux measurement."

"Because the X-ray [luminosity] of Vega [is] much closer to that of the Sun than to the typical galactic X-ray sources which have been detected to date, it is natural to consider processes analogous to solar coronal activity as the explanation for the X-ray activity."

"Vega is thought to be a solitary star, and therefore noncoronal X-ray-producing mechanisms seem to be excluded".

"Vega is the first solitary main-sequence star beyond the Sun known to be an X-ray emitter".

Vega's "computed X-ray surface luminosity [...] is comparable to that of the quiet Sun [...] Note, however, that because of our very short exposure, the average level of coronal emission may vary significantly from our single measurement."

"Using estimates of the stellar [radius] derived from stelar structure calculations, we obtain [a] surface X-ray [luminosity] of ~6.4 x 104 ergs cm-2 s-1 for Vega [that falls] within the range of solar coronal X-ray emission, which can vary between ~8 x 103 ergs cm-2 s-1 in coronal holes and ~3 x 106 ergs cm-2 s-1 in active regions".

Magnetic "field activity, leading to coronal heating, may account for Vega's X-ray emission because of inhomogeneous distribution of surface magnetic flux and associated coronal activity."

That Vega is regarded as an X-ray source rests on one 4.8 s star-tracking observation by one sounding rocket flight carrying an X-ray detector flown on many flights that yields trustworthy results.

"Vega is a pole-on, highly oblate, rapid rotator [...] the star exhibits extreme limb darkening and a large decrement in effective temperature from pole to equator. [...] the best fittingmodel (Teff pole=10150 K, Teff eq = 7900 K, θ = 3.329 mas) has the pole inclined 5° to line of sight and rotates at 91% of the angular speed of break-up, resulting in a temperature drop of 2250 K from center to limb. [...] the total luminosity [...] is emitted in a highly non-homogeneous manner with five times more UV flux being emitted from the pole as is emitted in the equatorial plane, while the visible through near-IR flux is some 70% greater at the pole than that of the equatorial plane and 54% greater than that expected from a slow or non-rotating A0 V star."

A 'polar coronal hole' is a coronal hole that occurs above one or both rotational poles of a star that has a coronal cloud around it.

"The radiant emission from coronal holes is greatly diminished relative to other coronal regions".

The "emission is proportional to the integral of the square of the electron density along the line of sight [...] Data of this type are therefore heavily influenced by regions of high density along the line of sight--the low corona for disk observations, and denser structures surrounding coronal holes for limb observations."

An "analysis of the northern polar region during the period 1973 June 29 to July 13 [...] can be summarized as follows. The boundary of the hole is essentially axisymmetrc about the polar axis and is nearly radial from 3 to 6 R⊙. The boundary at these heights is located at 25° ± 5° latitude, although it is of much smaller extent (boundary ~65° latitude) as observed near the solar surface with the American Science and Engineering (AS&E) X-ray experiment on Skylab [...] the increase of the polar hole's cross sectional area from the surface to 3 R⊙ is approximately 7 times greater than for a purely radial boundary."

For α Lyr, log FX/FV = -6.79 (variable X-ray source), log LX 27.6 erg s-1 (variable X-ray source). Upper limits were log FX/FV = -7.4 and log LX 27.0 erg s-1.

A coronal cloud is not a diffuse, homogeneous hot atmosphere, but one or more strongly structured topologically closed features dominated by magnetic confinement.

Magnetic field of Vega
An extensive convection zone is not required, and any star with magnetic field strengths and geometry similar to the Sun's will possess a corona.

Magnetic fields on the order of ~30 gauss have been reported for Vega (~1 gauss for the Sun), so perhaps these substantially higher average field strengths compensate for the expected reduced convective activity, resulting in surface X-ray luminosities comparable to the quiet Sun.

Using spectropolarimetry, a magnetic field has been detected on the surface of Vega by a team of astronomers at the Observatoire du Pic du Midi. They "report the detection of a magnetic field on Vega and argue that Vega is probably the first member of a new class of yet undetected magnetic A-type stars."

The "polarization [is] a Zeeman signature [that] leads to a value of [Bl =] -0.6 ± 0.3 G for the disk-averaged line-of-sight component of the surface magnetic field."

"The strength of Vega magnetic field is about 50 micro-tesla, which is close to that of the mean field on Earth and on the Sun."

Rotational velocity of Vega
"Vega rotates in less than a day, while the Sun's rotation period is 27 days."

Infrared analysis
"The infrared excesses are well modeled by two components, a warm belt close to the star, and a cooler belt farther out. The clear separation of the belts could be explained by the presence of planets clearing the gap."

The graph at left shows the clear separation of infrared belts for Vega. This separation may "be explained by the presence of planets clearing the gap."

Sun as an X-ray source
The photosphere of the Sun does not emit X-rays. The chromosphere and the transition region either emit ultraviolet, extreme ultraviolet, or X-rays (most likely soft X-rays). The coronal clouds around the Sun emit X-rays and sometimes gamma-rays, neutrinos, neutrals, protons, positrons, and electrons, among other solar cosmic-rays.

The X-ray characteristics of the Sun have been studied since the 1940s. The may be considered an X-ray variable star as its intensity corresponds to the sunspot cycle. This cycle may have its origins in the mechanisms that heat the photosphere and the coronal clouds around the Sun. An analysis of the X-ray characteristics of Vega suggest that it is a Sun-like X-ray star.

It has taken a number of decades to observe and describe the X-ray properties of Vega. Associated with these properties are a magnetic field comparable to the Sun and the possibility of a coronal hole over the pole facing Earth.

By scanning the available literature to ascertain the X-ray properties of Vega, several apparent conclusions may be drawn. The X-ray output of Vega falls between that of the Sun. The X-ray output of the Sun minimizes during the solar cycle quiet period and maximizes at the sunspot maximum.

Vega is considered an X-ray variable star with a corona and an X-ray output comparable to the Sun.

Vega characteristics
Vega is considered to be Sun-like in its X-ray output and variability. The peak of X-ray output may not be directly observable as the star has a pole facing Earth.

The photosphere of Vega has a diameter five times that of the Sun. Its apparent stellar system has similarities to the solar system but is scaled as approximately four times larger. Even with a pole temperature above 10,000 K Vega produces no detectable X-ray output from its photosphere, just like the Sun at 5,778 K. Vega is a visual spectral type A0V star which means it is transparent. The Sun is not considered transparent at visual wavelengths.

The physical size of the photosphere of Vega and its transparency may reflect more the cloud it formed from than anything else.

The above surface fusion that is occurring on the Sun may not be happening above the photosphere of Vega as no flares or gamma rays have been detected.

Vega is a Sun-like X-ray source.

The characteristics that allow Vega to be seen as a Sun-like X-ray source suggests that if the Sun's X-ray characteristics have not changed over time it may have been in a wide-orbit binary with any star whose X-ray characteristics allow the Sun to remain much as it is.

Sun
For comparison with other stars, the Sun has the following properties:
 * The effective temperature of the surface of the Sun's photosphere is 5,778 K.
 * Metallicity, Z = 0.0122, "lowest seismic estimate of solar metallicity is Z = 0.0187 [to the] highest is Z = 0.0239, with uncertainties in the range of 12%-19%."
 * Stellar companion: Jupiter at present, perhaps Uranus in some larger form previously
 * Age: 4.57 billion years
 * B-V = 0.656 ± 0.005
 * Rotation rate: 7.189 x 103 km h-1 (at the equator), equatorial circumference of 4,379,000 kilometres divided by sidereal rotation period of 609.12 hours

Metallicity
The hydrogen mass fraction is generally expressed as $$X\equiv \frac{m_\mathrm{H}}{M}$$ where $$M$$ is the total mass of the system and $$m_\mathrm{H}$$ the mass of the hydrogen it contains.

"[T]he helium mass fraction is denoted as $$Y\equiv \frac{m_\mathrm{He}}{M}$$.

The metallicity—the mass fraction of elements heavier than helium—can be calculated as

 * $$Z = \sum_{i>\mathrm{He}} \frac{m_i}{M} = 1 - X - Y.$$

 * $$X = 0.7393.$$

 * $$Y = 0.2485.$$

Sun-Jupiter binary
The Sun-Jupiter binary may serve to establish an upper limit for interstellar cometary capture when three bodies are extremely unequal in mass, such as the Sun, Jupiter, and a third body (potential comet) at a large distance from the binary. The basic problem with a capture scenario even from passage through “a cloud of some 10 million years, or from a medium enveloping the solar system, is the low relative velocity [~0.5 km s-1] required between the solar system and the cometary medium.” The capture of interstellar comets by Saturn, Uranus, and Neptune together cause about as many captures as Jupiter alone.

Saturn
"There is one God, greatest among gods and men, neither in shape nor in thought like unto mortals ... He abides ever in the same place motionless, and it befits him not to wander hither and thither."

"Saturn, the old man who lives at the north pole, and brings with him to the children of men a sprig of evergreen (the Christmas tree), is familiar to the little folks under the name Santa Claus, for he brings each winter the gift of a new year."

"The religions of all ancient nations ... associate the abode of the supreme God with the North Pole, the centre of heaven; or with the celestial space immediately surrounding it."

"Lenormant, speaking of Rome and Olympia, remarks, "It is impossible not to note that the Capitoline was first of all the Mount of Saturn, and that the Roman archaeologists established a complete affinity between the Capitoline and Mount Cronios in Olympia, from the standpoint of their traditions and religious origin (Dionysius Halicarn., i., 34). This Mount Cronios is, as it were, the Omphalos of the sacred city of Elis, the primitive centre of its worship. It sometimes receives the name Olympos."1 Here is not only symbolism in general, but also a symbolism pointing to the Arctic Eden, already shown to be the primeval mount of Kronos, the Omphalos of the whole earth.2"

"As an offshoot of these Hellenistic speculations we should place Tacitus, Histories V,2: "Iudaeos Creta insula profugos novissima Libyae insedisse memorant, qua tempestate Saturnus vi Jovis pulsus cesserit regnis" (quoted from Loeb Classical Library)." i.e., "Jews were fugitives from the island of Crete and settled in Libya recorded the time when Saturn was driven from his throne by force of Jupiter".

"The motif of Saturn handing over power to Jupiter derives, of course, from Hesiod's account of the succession of the gods in his Theogony, and his story of the five successive ages of men -- the first, or golden, age being under the reign of Kronos (Saturn) and the following ages being under the reign of Zeus (Jupiter) -- in his Works and Days (110ff.). These stories were often retold. Ovid, for example, combines in his Metamorphoses the stories in the Theogony and Works and Days, telling us how, "when Saturn was consigned to the darkness of Tartarus, and the world passed under the rule of Jove, the age of silver replaced that of gold."8"

Much of the legend surrounding this early Saturn suggests that it may have been in a binary star system with the Sun.

Pole stars
At the present time, the northern pole star, or North Star, is a moderately bright star with an apparent magnitude of 1.97 (variable), the brightest star in the Ursa Minor constellation (at the end of the or "handle" of the "Little Dipper" asterism). Its current (October 2012) declination is +89°19'8" (as per epoch J2000 it was +89°15'51.2"). Therefore it always appears due north in the sky to a precision better than one degree, and the angle it makes with respect to the horizon is equal to the latitude of the observer. It is consequently known as Polaris (from Latin stella polaris "pole star"). It also retains its older name, Cynosura, from a time before it was the pole star, from its Greek name meaning "dog's tail" (as the constellation of Ursa Minor was interpreted as a dog, not a bear, in antiquity).

Due to the precession of the equinoxes (as well as the stars' proper motions), the role of North Star passes from one star to another. The name stella polaris has been given to α Ursae Minoris since at least the 16th century, even though at that time it was still several degrees away from the celestial pole. Gemma Frisius determined this distance as 3°7' in the year 1547.

In the Roman era, the celestial pole was about equally distant from α Ursae Minoris (Cynosura) and β Ursae Minoris (Kochab). Before this, during the 1st millennium BC, β Ursae Minoris was the bright star closest to the celestial pole, but it was never close enough to be taken as marking the pole, and the Greek navigator Pytheas in ca. 320 BC described the celestial pole as devoid of stars. Polaris was described as αει φανης "always visible" by Stobaeus in the 5th century, when it was still removed from the celestial pole by about 8°. It was known as scip-steorra ("ship-star") in 10th-century Anglo-Saxon England, reflecting its use in navigation.

The precession of the equinoxes takes about 25,770 years to complete a cycle. Polaris' mean position (taking account of precession and proper motion) will reach a maximum declination of +89°32'23", so 1657" or 0.4603° from the celestial north pole, in February 2102. Its maximum apparent declination (taking account of nutation and aberration) will be +89°32'50.62", so 1629" or 0.4526° from the celestial north pole, on 24 March 2100.

In 3000 BC the faint star Thuban in the constellation Draco was the North Star. At magnitude 3.67 (fourth magnitude) it is only one-fifth as bright as Polaris, and today it is invisible in light-polluted urban skies.

The Celestial south pole is moving toward the Southern Cross, which has pointed to the south pole for the last 2,000 years or so. As a consequence, the constellation is no longer visible from subtropical northern latitudes, as it was in the time of the ancient Greeks.

There have been many pole stars throughout the millennia. Around 2000 BC, the star Eta Hydri was the nearest bright star to the Celestial south pole. Around 2800 BC, Achernar was only 8 degrees from the south pole.

Orbital poles
An orbital pole is either end of an imaginary line running through the center of an orbit perpendicular to the orbital plane, projected onto the celestial sphere. It is similar in concept to a celestial pole but based on the planet's orbit instead of the planet's rotation.

The north orbital pole of a celestial body is defined by the right-hand rule: If you curve the fingers of your right hand along the direction of orbital motion, with your thumb extended parallel to the orbital axis, the direction your thumb points is defined to be north.

At right is a snapshot of the planetary orbital poles. The field of view is about 30°. The yellow dot in the centre is the Sun's North pole. Off to the side, the orange dot is Jupiter's orbital pole. Clustered around it are the other planets: Mercury in pale blue (closer to the Sun than to Jupiter), Venus in green, the Earth in blue, Mars in red, Saturn in violet, Uranus in grey partly underneath Earth and Neptune in lavender. Dwarf planet Pluto is the dotless cross off in Cepheus.

Uranus
In the Chinese, Japanese, Korean, and Vietnamese languages, the planet's name is literally translated as the sky king star.

Uranus is named after the ancient Greek deity of the sky Uranus, the father of Cronus (Saturn) and grandfather of Zeus (Jupiter). Though it is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit.

Ouranos
“Uranus was the Sky in Greek mythology, which was thought to be dominated by the combined powers of the Sun and Mars.

“Uranus ..., Ouranos meaning "sky" or "heaven") was the primal Greek god personifying the sky. His equivalent in Roman mythology was Caelus. In Ancient Greek literature, Uranus or Father Sky was the son and husband of Gaia, Mother Earth. According to Hesiod's Theogony, Uranus was conceived by Gaia alone, but other sources cite Aether as his father.

Caelus
Caelus or Coelus was a primal god of the sky in Roman myth and theology, iconography, and literature (compare caelum, the Latin word for "sky" or "the heavens", hence English "celestial").

“The name of Caelus indicates that he was the Roman counterpart of the Greek god Uranus, who was of major importance in the theogonies of the Greeks. Varro couples him with Terra (Earth) as pater and mater (father and mother), and says that they are "great deities" (dei magni) in the theology of the mysteries at Samothrace.

According to Cicero and Hyginus, Caelus was the son of Aether and Dies ("Day" or "Daylight"). Caelus and Dies were in this tradition the parents of Mercury. Caelus was the father with Hecate of the distinctively Roman god Janus, as well as of Saturn and Ops. Caelus was also the father of one of the three forms of Jupiter, the other two fathers being Aether and Saturn.

Solar-like binaries
For a solar-like binary system, the primary has Teff ≲ 6000 K.

"TYC 4410-01037-1 [has] a mass of 1.07 ± 0.08 M⊙ and radius of 0.99 ± 0.18 R⊙. ... Teff = 5879 ± 29 K [and] [Fe/H] = -0.01 ± 0.05".

At right is a Keck adaptive optics image of TYC 4110-01037-1 in K′. A faint candidate tertiary companion (indicated by the arrow) with red colors is separated by 986 ± 4 mas from the primary star. If it is physically associated with the primary, it is most likely a dM3-dM4 star. The companion is designated MARVELS-3B.

Its "low-mass stellar companion [has a] small mass ratio [ q ≥ 0.087 ± 0.003] and short orbital period [78.994 ± 0.012 days, which] are atypical amongst solar-like ... binary systems. [The orbit has] an eccentricity of 0.1095 ± 0.0023, and a semi-amplitude of 4199 ± 11 m s-1. ... the minimum companion mass (if sin i = 1) [is] 97.7 ± 5.8 MJup."

"One possible way to create such a system would be if a triple-component stellar multiple broke up into a short period, low q binary during the cluster dispersal phase of its lifetime. A candidate tertiary body has been identified in the system via single-epoch, high contrast imagery. If this object is confirmed to be co-moving, ... it [may] be a dM4 star."

Binary twins
16 Cyg A and B are binary solar twins.

"16 Cygni or 16 Cyg is a triple star system approximately 69 light-years away from Earth in the constellation of Cygnus. It consists of two Sun-like yellow dwarf stars, 16 Cygni A and 16 Cygni B, together with a red dwarf, 16 Cygni C. In 1996 an extrasolar planet was discovered in an eccentric orbit around 16 Cygni B.

16 Cygni is a hierarchal triple system. Stars A and C form a close binary with a projected separation of 73 AU. The orbital elements of the A–C binary are currently unknown. At a distance of 860 AU from A is a third component designated 16 Cygni B.

"B orbits between 100 and 160 degrees inclination, that is against the A–C pole such that 90 degrees would be ecliptical.

"Both 16 Cygni A and 16 Cygni B are yellow dwarf stars like our Sun. According to data from the Geneva–Copenhagen survey, both stars have masses similar to the Sun. Age estimates for the two stars vary slightly, but 16 Cygni is likely to be much older than the Solar System, at around 10,000 million years old. 16 Cygni C is much fainter than either of these stars, and may be a red dwarf.

"Despite differing in Teff by only 35-40 K, the Li abundances of 16 Cyg A and B differ by a factor of ≥ 4.5. The solar photospheric abundance is intermediate to the two values. This intermediacy indicates that the Sun, whose highly depleted photospheric Li abundance is in gross conflict with standard stellar models, is not an isolated anomaly in its Li abundance evolution."

"In 1996 an extrasolar planet in an eccentric orbit was announced around the star 16 Cygni B. The planet's orbit takes 798.5 days to complete, with a semimajor axis of 1.68 AU.

""For the 16 Cyg B system, only particles inside of about 0.3 AU remained stable [within a million years of formation], leaving open the possibility of short-period planets". For them, observation rules out any such planet of over a Neptune mass.

Binary analogs
α Cen A and B are binary solar analogs.

"The two components α Cen A and B are separated by roughly 25 AU, with an orbital period of 80 years. The age of the system is thought to be slightly larger than that of the Sun, correspondingly both stars are also slow rotators (periods are 29 (A) and 42 (B) days) with a rather inactive corona."

"[F]ive XMM-Newton observations of the binary system α Centauri ... observed in snapshot like exposures of roughly two hours each during the last two years [has found that] the X-ray emission of the system is dominated by α Cen B, a K1 star. ... the optically brighter component α Cen A, a [G2V] star very similar to our Sun, [has] fainted in X-rays by at least an order of magnitude during the observation program, a behaviour never observed before on α Cen A, but rather similar to the X-ray behaviour observed with XMM-Newton on HD 81809."

Interstellar cometary captures
"NASA's Hubble Space Telescope has detected several comets diving toward a young star about 95 light-years from Earth."

"HD 172555 [...] represents the third extrasolar system where astronomers have detected such comets, [...] known as "exocomets" because they're outside Earth's solar system."

"The presence of comets falling toward HD 172555 was determined based on observations of nearby gases, which [...] are the vaporized remnants of disintegrated comets after they have ricocheted off unseen Jupiter-size planets. The massive planet's gravity catapults the comets into the star in a process known as "gravitational stirring." Similar processes can be seen in our own solar system when sungrazing comets plunge into the sun."

"Seeing these sun-grazing comets in our solar system and in three extrasolar systems means that this activity may be common in young star systems."

"This activity at its peak represents a star's active teenage years. Watching these events gives us insight into what probably went on in the early days of our solar system, when comets were pelting the inner solar system bodies, including Earth. In fact, these star-grazing comets may make life possible, because they carry water and other life-forming elements, such as carbon, to terrestrial planets."

"HD 172555 is part of a collection of stars known as the Beta Pictoris Moving Group. Another one of the stars, Beta Pictoris, is known to have a young gas-giant planet forming in its protoplanetary disk of dust and gas. This collection of stars is the closest star system to Earth and could be a breeding ground for terrestrial planets."

"Silicon and carbon-gas signatures were detected in the vicinity of HD 172555 using Hubble's Space Telescope Imaging Spectrograph (STIS) and the Cosmic Origins Spectrograph (COS)."

"The gas was moving at about 360,000 miles per hour across the face of the star. The most likely explanation for the speedy gas is that Hubble is seeing material from comet-like objects that broke apart after streaking across the star's disk."

"Hubble shows that these star-grazers look and move like comets, but until we determine their composition, we cannot confirm they are comets. We need additional data to establish whether our star-grazers are icy like comets or more rocky like asteroids."

"Nightly changes in the absorption strength of the Ca II K-line near the stellar radial velocity were observed in four of the stars (HD 21620, HD 110411, HD 145964 and HD 183324). This type of absorption variability indicates the presence of a circumstellar gas disk around these stars."

Weak "absorption features that sporadically appear with velocities in the range ± 100 km s-1 of the main circumstellar K-line in the spectra of HD 21620, HD 42111, HD 110411 and HD 145964 [plus] the known presence of both gas and dust disks surrounding these four stars, these transient absorption features are most probably associated with the presence of Falling Evaporated Bodies (FEBs, or exocomets) that are thought to liberate gas on their grazing trajectory toward and around the central star."

"This now [2013] brings the total number of A-type stars in which the evaporation of Ca II gas from protoplanetary bodies (i.e., exocomets) has been observed to vary on a nightly basis to 10 systems [including HD 256 (HR 10), HD 9672 (49 Ceti), HD 39060 (Beta Pictoris), HD 85905, HD 182919 (5 Vulpeculae), HD 217782 (2 Andromedae)]. A statistical analysis of the 10 A-stars showing FEB-activity near the Ca II K-line compared to 21 A-type stars that exhibit no measurable variability reveals that FEB-activity occurs in significantly younger stellar systems that also exhibit chemical peculiarities. The presence of FEB-activity does not appear to be associated with a strong mid-IR excess. This is probably linked to the disk inclination angle, since unless the viewing angle is favorable the detection of time-variable absorption may be unlikely. Additionally, if the systems are more evolved then the evaporation of gas due to FEB activity could have ceased, whereas the circumstellar dust disk may still remain."

Interstellar planet captures
The "hypothetical Planet Nine could have been lost by another solar system and then poached from the intergalactic wastes by our sun's gravity."

The "mysterious planet, if it does exist in the outermost reaches of the solar system, may have been a "rogue" that was captured by the sun's gravity."

Certain "gravitational anomalies in the outer solar system could be explained by a massive planet lurking beyond the observed reaches of the solar system, around 20 times farther than Neptune's average distance from the sun."

"A rogue planet is an object that formed like a planet from a disk around a star, like the planets in our own solar system. However, if the planet passed nearby a much more massive planet early in its formation, before the orbits in its home system settled down, it could get slingshot out of its solar system, and would now be wandering through interstellar space in the Milky Way among the stars."

The "rogue planet got tossed out of the system by gravitational forces in 60 percent of the simulations – but in the other 40 percent, it got captured by the sun."

"Imagine that the Sun was the size of an orange or an apple. Imagine the planets as maybe fruit flies buzzing around the apple-sized Sun. On this scale, the next closest star to the Sun, Proxima Centauri, would be another apple roughly 1,400 miles away! That's roughly Chicago to Tucson. Now imagine the chance of a fruit fly in Chicago making its way 1,400 miles and finding the apple in Tucson. It could happen, but it's not the way to bet."

"The 'classical' planets, Mercury, Venus, Mars, Jupiter, and Saturn are all easily visible to the naked eye and have been known for thousands and thousands of years. Because these objects changed their positions in the sky night after night compared to the background stars (which never seemed to change), god-like attributes were given to the planets. In fact, the name 'planet' comes from the Greek word for 'wanderer.'"

"Those [discoveries of later planets] served to show people how expansive the universe was and how much there was to learn. But it generally did not change the worldview of the civilizations that discovered them because those discoveries did not fundamentally change the picture of the universe they had, the way Copernicus and Galileo changed our understanding of the place of the Earth in the solar system, or the way Einstein changed our perceptions of space and time."

"If [Planet Nine] really exists, and is confirmed and observed, it will likely tell us that the process of planet formation is more violent, and chaotic, than previously thought. And it would tell us that there is still a lot of space to explore where new discoveries may be lurking."

Hypotheses

 * 1) At some point, perhaps around 40,000 b2k, the Sun-Earth system was in a binary with a smaller star that was a pole star for the north geographic/rotational pole of the Earth.

For a solar binary, proof of concept is that the Sun and Jupiter together can act in some way like a stellar binary.

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User:Egm6322.s12.team1.zheng.zx/R11

Problem 6: Plot Function and Find non-zero coefficients
 Solved without assistance

Find: A & B
A) Plot the function given in Eq6.1 B) Find the first three non-zero coefficients of the Fourier-Legendre Series, if not analytically then numerically using GL Quadrature with $$ 10^6 \ $$ accuracy.

Solution:

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\displaystyle f(\theta)=\frac{1}{1+\sin^2(sin^2 \theta)} $$
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\displaystyle \mu:=\sin \theta $$
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\displaystyle F(\mu)=f(\theta)=\frac{1}{1+\sin^2(\mu^2)} $$
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\displaystyle F(\mu)=\sum_{j=0}^{\infty}A_jP_j(\mu) $$
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\displaystyle A_j=\frac{\langle P_j,F \rangle}{\langle P_j,P_j \rangle}=\frac{2j+1}{2} \int \limits_{\mu=-1}^{\mu=+1}P_j(\mu)F(\mu)d\mu $$
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The first several Legendre polynomials are:
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\displaystyle P_0(\mu)=1, \, P_1(\mu)=\mu $$
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\displaystyle P_2(\mu)=\frac{1}{2}(3\mu^2-1) $$
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\displaystyle P_3(\mu)=\frac{1}{2}(5\mu^3-3\mu) $$
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\displaystyle P_4(\mu)=\frac{1}{8}(35\mu^4-30\mu^2+3) $$
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\displaystyle A_0=\frac{1}{2}\int_{-1}^11\cdot \frac{1}{1+\sin^2(\mu^2)}d\mu $$
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For the equation above can't be integrated analytically, then we use GL quadrature.
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\displaystyle A_0=\frac{1}{2}\cdot \sum_{j=1}^{n}w_j\cdot g(x_j) $$
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Here we use three points for accuracy.
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\displaystyle \left\{\begin{matrix} x_1=-\sqrt{\frac{3}{5}}&w_1=\frac{5}{9} \\ x_2=0&w_2=\frac{8}{9} \\ x_3=\sqrt{\frac{3}{5}}&w_3=\frac{5}{9} \end{matrix}\right. $$
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then:
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\displaystyle \begin{align} A_0 &=\frac{1}{2}[w_1\cdot g(x_1)+w_2\cdot g(x_2)+w_3\cdot g(x_3)]\\ &=0.8657 \end{align} $$
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\displaystyle \begin{align} A_1 &=\frac{3}{2}\int_{-1}^{1}\mu \cdot \frac{1}{1+\sin^2(\mu^2)}d\mu \\ &=\frac{3}{2}\sum_{j=1}^n w_j\cdot g(x_j) \\ &=\frac{3}{2}[w_1\cdot g(x_1)+w_2\cdot g(x_2)+w_3\cdot g(x_3)]\\ &=0 \end{align} $$
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\displaystyle \begin{align} A_2 &=\frac{5}{2}\int_{-1}^1 P_2(\mu)F(\mu)d\mu\\ &=\frac{5}{2}\sum_{j=1}^n w_j\cdot g(x_j)\\ &=-0.2686 \end{align} $$
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\displaystyle \begin{align} A_3 &=\frac{7}{2}\int_{-1}^1 P_3(\mu)F(\mu)d\mu\\ &=\frac{7}{2}\sum_{j=1}^n w_j\cdot g(x_j)\\ &=0 \end{align} $$
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From A4, we begin to use five points for accuracy.
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\displaystyle \begin{align} A_4 &=\frac{9}{2}\sum_{j=1}^n w_j\cdot g(x_j)\\ &=-0.0707 \end{align} $$
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\displaystyle F(\mu)=\sum_{j=0}^{\infty} A_jP_j(\mu) $$
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\displaystyle f(\theta)=\sum_{j=0}^{\infty}A_jP_j(\sin\theta) $$ Plot the results(Fourier-Legendre series of function $$f(\theta)$$) using Matlab: for only one term: for three terms: for five terms: Comparing with the originally exact one: from the above results, we see that with the increase of number of terms, it shows the convergence toward the original function.
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Progress and Prospects in Parkinson's Research/Causes/Deficiencies

< Back to Causes

Background
A number of toxins have proved to be direct causative factors for Parkinson’s Disease (Paraquat, Maneb, Rotenone, MPTP etc.) but collectively they account only for small proportion of the known cases. The principal causative agencies such as environmental triggers await discovery. Yet, in spite of considerable effort and expenditure, nothing significant has come to light. The human cell is a complex chemical factory, ingesting all manner of proteins and molecules in order to fulfil its predestined role. It could be hypothesised therefore that some vital neurological ingredient might be missing and that PD is in fact a deficiency disease.

Deficiency diseases are by no means uncommon. Some examples are:- Diabetes (insulin), Goitre (iodine), Keshan disease (selenium) and Growth Disorder (zinc). The missing components are sometimes absent from diet, while others need to be manufactured within the body.

Some candidates are offered here for consideration.

Two of them viz Blood and Norepinephrine are noteworthy but cannot be taken as authoritative since:-

 * They have not been corroborated from any other source.
 * The observed effects may be secondary symptoms and not a primary cause.
 * No hypothesis is advanced to account for the results.

Two others, Zinc and Vitamin D, have attracted considerable attention, inspired a number of research projects and are the subject of clinical trials.

Research
2012

Kaasinen et al have found that the production of dopamine in the human brain varies according to the season and also the month of birth. The findings were based upon PET Scans of 109 PD patient.

" The patients scanned during fall and winter had 15% higher tracer uptake in the right putamen compared to patients scanned during spring and summer. Patients born during winter and spring had 10% higher dopamine synthesis capacity in the left caudate, 8% higher capacity in the right caudate and 16% higher capacity in the putamen contralateral to the side of predominant motor symptoms compared to patients born during summer and fall (after correcting for differences in age, sex, disease severity, scanner and season of scanning). "

Related Pages
Causes

Blood - Glutathione - Norepinephrine - Vitamin D - Zinc


text:
Progress and Prospects in Parkinson's Research/Causes

< Back to Progress and Prospects in Parkinson's Research

The hunt for the causes of Parkinson’s Disease

 Many diseases have a clear cut point of origin, but one of the more baffling features of Parkinson’s Disease is that it seems capable of being initiated in a host of different ways, yet all appear to produce a similar outcome.

This page describes some of the studies on clusters of Parkinson's cases where clues to causes can be discerned. This is preceded by some general comments on some noteworthy characteristics of the disease.

The PD Conundrum
Currently every attempt at a generalisation about the cause of the disease faces a contradiction, exception or counter-argument.

All diseases involve the destruction of or damage to cells. Cells may be ruptured by blows or pressure; they may be starved of nutrients or lose their energy supplies; they may be poisoned by toxins; they can self-destruct or malfunction through inherited defects; and they can be attacked by invaders such as bacteria, viruses or prions. All of these types of cause have been noted as contributing to the Parkinson’s condition, leading to speculation that it may be a collection of diseases which happen to produce common symptoms or alternatively one disease which requires a combination of initiating factors. What seems beyond contention is that the disease is not contagious. There are however occasional cases where both a husband and wife have contracted the disease (termed Conjugal Parkinsonism), but more often than not they are attributed to both individuals having been exposed to one of the known toxic causal risks such as pesticides.

There is no clinical test for the disease: no biomarker. Diagnosis is usually made by observation of four signature symptoms:- muscular stiffness, slow movement (bradykinesia), imbalance and resting tremor. There are a host of other symptoms, which vary from patient to patient. As a consequence cases of misdiagnosis are not uncommon. Other cases remain undiagnosed such as those in the pre-symptomatic (prodromal) phase of the disease.

There is also clear statistical evidence that the risk of contracting the disease increases with age (although early onset cases are by no means unknown). It could be argued that Parkinson’s is a natural by-product of the aging process and if everyone lived long enough they would all eventually succumb to the condition. Animals do not get the disease naturally. Even chimpanzees, who share 98.5% of human DNA, are not susceptible to PD. This may be a pointer to a defect in the human genetic make-up or may simply reflect the extended life expectancy of humans.

Having Parkinson's Disease is rather like being in charge of a chemical factory where the clocks in each department run at different speeds. Without a clear insight into cause and its consequences there can be no effective preventative action for the condition or a treatment which reverses the symptoms permanently, and this leads to a position where the best that can be achieved is the repair of the resultant damage once it has occurred, and at worst the palliative treatment of individual symptoms. Disease symptoms may be attributed directly to a point of origin, for example nasal infection with a norovirus produces runny noses and sneezing. But in many cases the cause starts a chain reaction around the body and the most affected organs are remote from the seat of the problem. This could be the case with Parkinson’s. The disease is most closely associated with movement disorders arising from a shortfall in the production of the neurotransmitter dopamine by a part of the brain called the substantia nigra. Dopamine replacement therapy is therefore currently the most effective form of palliative treatment. This does address the movement problems but there are many other non-motor symptoms such as impaired speech or disrupted sleep patterns, which are less responsive to this form of medication, leading to the supposition that many other organs are affected by the disease. Dopamine is produced in at least two other areas in the brain which seem to be unaffected by the disease.Dopamine#Functions in the brain

Cannon et al (2011) sum up the difficulties in finding an environmental cause for PD.

"Given the amount of research that has been conducted, the general conclusion that can be drawn is that outside of a few rare cases, it is highly unlikely that exposure to a single agent accounts for a significant number of cases. Much more likely, multiple hits over time from numerous compounds, in association with a background of genetic risk factors, are responsible for most cases."

and also:-

''Numerous other classes of environmental agents have been linked to PD, including organochlorines, organophosphates, and carbamates. However, currently, there is limited epidemiological evidence and chronic animal-based, laboratory-based research is mostly lacking.''

The Multiple Hits Hypothesis
Over the past 20+ years a wider view of PD has begun to emerge. No longer simply an unfortunate encounter between genetics and environment, PD reveals itself as a complex`interplay between a half-dozen body systems.

Clusters
Where clusters of the occurrence of a disease can be identified, this may provide a pointer as to its cause. Priyadarshi et al (2001) carried out a comprehensive review of previous epidemiological studies of the disease and found that there was clear evidence of increased risk associated with living in a rural area, farming, drinking well water and exposure to pesticides, fungicides and herbicides.

The Amish, USA
The Amish are a sub group within the Christian church. They originated in the German-speaking parts of Switzerland. Amish communities are found in Pennsylvania, Indiana and parts of Canada and in total number some 250,000 individuals. The rules of the church demand strict adherence and include prohibitions or limitations on the use of power-line electricity, telephones, and machinery such as cars, as well as regulations on clothing and behaviour. Amish members will not buy insurance, accept social security payments or perform military service. The Amish communities are tightly knit and marriage outside the community is discouraged.

The Amish are also noteworthy for having the world’s highest prevalence of Parkinson’s Disease. This is 5,700 cases per 100,000 of the population over 60, and is two to three times the average. This has been widely cited as circumstantial evidence that genetic factors may be at work. This hypothesis was evaluated by Racette et al(2009).

They studied the pedigrees of a number of members of the Amish community with PD and found no evidence of a pattern of Mendelian heredity as a cause. The community is largely devoted to agriculture, which includes the spreading of modern pesticides by hand, and it seems possible that the prevalence of the disease is associated with pesticide toxicity.

As is so often the case with PD, contradictory evidence was not long in coming. Cummings et al (2011) studied the genomes of members of the Amish community and found statistical evidence to support the hypothesis that abnormalities in chromosome 6 might be the cause of the cluster.

Brescia, Italy
Brescia in Northern Italy also has a high prevalence of Parkinson’s Disease and in 2007 a total of 2,677 patients were identified in a population of 903,977 residents. Lucchini et al (2007) evaluated these and could find no evidence for Mendelian succession. When the cases were plotted geographically the clusters could be seen to coincide with the zones of fallout of manganese dust particles from the local ferroalloy industrial sites. Manganese has been recorded at several previous sites as a toxic originator of PD.

Manganese inhibits tyrosine hydroxylation, which is essential for the formation of dopamine. It has previously been implicated in the onset of PD in conjunction with welding and mining processes.

Sofia, Bulgaria
Negative clusters are very hard to detect, but Mlanov et al (2000) found that among gypsies in the Sofia region of Bulgaria the prevalence of Parkinson’s Disease was 16/100,000 (based on one case) compared with 137/100,000 for the rest of the Caucasian population. No hypothesis was advanced to explain this but the inference is that they form a racial sub-group and might be genetically protected from the disease.

Bombay, (Mumbai) India
Barucha et al (1988) carried out a door-to-door survey of a community of 14,010 Parsis living in the Bombay area and registered 46 PD cases. The Parsis practice a form of Zoroastrian religion, for which one of the ceremonies involves getting children to inhale the fumes from burning the leaves of aspand plants (Esfand sventa) in order to rid them of the Evil Eye. A Shi'a tradition states that there is an angel in each of the plant's leaves and seeds. Its root drives away sorrow and magic, and the devil stays a distance of seventy houses away from homes in which it is kept. Shi'a sources tell of the benefits of ingesting aspand or its juice. For instance, drinking a bit of aspand juice every day for forty mornings brings about wisdom in addition to fortifying the imbiber against seventy varieties of diseases. In practice aspand smoke contains two alkaloids, harmine and harmaline. These are inhibitors of the enzyme Monoamine oxidase which forms part of the metabolic sequence in the neurological processing of dopamine in humans.

Guam, Pacific
Cox et al (2003) have described the high incidence of amyotrophic lateral sclerosis/parkinsonism-dementia complex (AL-SPDC), a neurodegenerative disease which starts with Parkinsonian symptoms but rapidly progresses to dementia and death. It is found among the Chamorro people on the island with an occurrence of 50 – 100 times above normal. The research determined that this came about through a complex chain of circumstances. The island is populated by cycad trees (Cycas micronesica), the fleshy seeds of which secrete a neurotoxin nonprotein amino acid beta-methylamino-l-alanine (BMAA). Flying foxes (Pteropus mariannus) eat the seeds and accumulate BMAA, which does not seem to harm them. The flying foxes in turn are prized as a delicacy by the Chamorro, who boil them in coconut cream and eat the whole animal at fiestas and ceremonies. The researchers successfully linked the neurotoxin to the disease.

As a postscriopt to this it should be noted that the Australian aborigines have developed a method of rendering the cycad fruit edible by a process of leaching out the toxins.

Nebraska
The American Parkinson’s Disease Association has identified Nebraska as the US State with the highest prevalence of PD with 329.3 cases per 100,000 of the population. It is the only State to implement legislation to create a statutory register of cases. The State has intensive farming of cereal crops and the high prevalence is generally attributed to crop spraying with pesticides, fungicides and herbicides.

United States
Willis et al (2010) carried out a statistical survey of US Medicare beneficiaries aged 65 and older from the years 1995 and 2000–2005. Using over 450,000 Parkinson’s disease cases per year, they calculated PD prevalence and annual incidence by race, age, sex, and county.

Their findings showed that the incidence of the disease increased steadily with old age without reaching any plateau. They found that people of White ethnicity had a substantially greater risk of contracting the disease than Blacks and Asians, indicating that susceptibility was influenced by genetic factors. They also confirmed the existence of a PD belt in the Midwest and Northeast regions of the country suggesting that environmental factors (pesticides?) might be involved.

China
Fukushima et al (2011) recruited a cohort of PD patients and non-PD cases from an outpatients clinic in China and took blood and urine samples. They found that the serum iron, whole-blood manganese and urine iron and copper levels were significantly higher in the PD patients than in the controls. The correlation coefficient between serum and urine concentrations of iron in the PD patients was significant. The serum vitamin E/urine copper ratio was significantly lower in the PD patients than in the controls. Serum vitamin E was negatively correlated with serum copper and was positively correlated with urine copper in the PD patients. Serum vitamin B12 was positively correlated with serum zinc in the PD patients and was negatively correlated with urine zinc in the controls. Mineral intake from the local diet was thought to be a causative factor.

Taiwan
Chen et al (2009) carried out a study of the prevalence rates of PD in the urban areas of Keelung City and compared these with the rural area of Ilan County, Taiwan. The results were similar to those obtained in Sicily, Rotterdam, and 3 communities in China. They found that the prevalence rates of PD in the urban area studied were twice as high as those in the rural area.

Faroe Islands & Greenland
Wermuth et al (1997) studied the prevalence of PD in the Faroe Islands and found indications of a cluster of 102 patients with parkinsonism and 82 with PD versus the expected 53. Their conclusions state:-

"The high prevalence may be due to early diagnosis and a higher ascertainment of cases with mild disease. However, a high incidence cannot be excluded."

A follow-up study (2004) found a similar high prevalence among the Inuit of Greenland.

North America
Sasco and Paffenbarger (1985) conducted a survey of 50,002 men who attended Harvard College (Cambridge, MA) or the University of Pennsylvania (Philadelphia, PA) between 1916 and 1950 and who were followed into adulthood for morbidity and mortality data.

Cases of Parkinson's Disease were identified from responses to mailed questionnaires and death certificates through 1978. They found that there was a statistically significant lower risk of incurring Parkinson’s Disease among men who had been infected with the measles virus during childhood. Their conclusions stated "These data may also suggest a truly protective effect of measles, compatible with some complex interaction between measles virus and the virus of the 1918 influenza epidemic."

This unexpected finding raises the intriguing possibility that measles vaccines could be 'tweaked' to prevent the onset of Parkinson's Disease.

Canada (British Columbia)
Allyson-Jones et al (2012) measured the incidence of PD among elderly Canadians in the province of British Columbia and their cause of death. Statistics were compiled for persons aged 65 and over for the years 1991/92 to 2000/2001

"Over the nine year period, age standardized incidence for males ranged from 207 to 396 per 100,000 person-years and 127 to 259 per 100,000 person-years for females. Persons with PD were at a 43% greater risk of all-cause mortality and specifically, 51% greater risk of injury mortality."


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Progress and Prospects in Parkinson's Research/Causes/Deficiencies/Vitamin D

Background
The inhabitants of Alaska are in something of a ferment about Vitamin D. They can’t get enough of it. A petition in March 2011 to the State legislature calls upon them to “adopt a prevention model of public health by increasing awareness about vitamin D deficiency, testing and supplementation.”  A Vitamin D Wiki has also been set up to achieve this and it includes a video debate on the subject.

Vitamins are essential organic compounds, which are required as nutrients in tiny amounts by an organism, and trigger all sorts of metabolic activity. The first discovery was Vitamin A (Retinol) in 1913, and the last discovery was Vitamin B9 (Folic Acid) in 1941. Their function, daily recommended allowance and the health consequences of over or under intake are well documented. They are associated with a number of diseases.

For example too little of Vitamin A can result in Night Blindness or Hyperkeratosis or Keratomalacia. Too much of Vitamin B5 on the other hand can induce Diarrhoea or Nausea or Heartburn. The same cannot be said, however, about Vitamin D.

Vitamin D was isolated by an American researcher, Elmer McCollum in 1921. He called it Vitamin D because it was the fourth such compound to be identified. Nutritionally it is found in fish (particularly salmon and tuna) and in dairy products. It is also uniquely synthesised by the action of Ultra- Violet rays from sunlight on the skin. This last aspect introduces a number of deficiency risk factors:-

 * Diet. (Low consumption of Vitamin D nutrients and consequently greater reliance on skin absorption.)
 * Body Mass Index. (Large people have more skin and, being better insulated, tend to wear less clothing.)
 * Latitude. (The nearer individuals live to a pole, the shorter their winter UV exposure.)
 * Skin colour. (Dark skinned races evolved nearer to the equator, where there is an abundant supply of UV sunlight). They carry an in-built sun-screen. Whereas fair skinned races, who evolved nearer to the poles where UV sunlight is scarcer, have developed an enhanced skin capacity to absorb it.
 * Life style. (UV absorption is regulated by how much time people spend indoors and how much of their skin they cover up when they are outdoors.)

There are more than enough variables here to generate a deficiency disease of a personal and sporadic nature.

There does not seem to be a scientific consensus on what Vitamin D does and how much of it you need.

"Vitamin D prevents rickets in children and osteomalacia in adults, and, together with calcium, helps to protect older adults from osteoporosis. Vitamin D also affects neuromuscular function, inflammation, and influences the action of many genes that regulate the proliferation, differentiation and apoptosis of cells."

Source - Wikipedia

"Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. Although the current interest in vitamin D as a nutrient with broad and expanded benefits is understandable, it is not supported by the available evidence. The established function of vitamin D remains that of ensuring bone health, for which causal evidence across the life stages exists and has grown since the 1997 DRIs were established (IOM,1997). The conclusion that there is not sufficient evidence to establish a relationship between vitamin D and health outcomes other than bone health does not mean that future research will not reveal a compelling relationship between vitamin D and another health outcome. The question is open as to whether other relationships may be revealed in the future."

Source - The Institute of Medicine 1997

2013

Deluca et al examined the relationhship between Vitamin D and neurological disorders:-

"This review highlights the epidemiological, neuropathological, experimental, and molecular genetic evidence implicating vitamin D as a candidate in influencing susceptibility to a number of psychiatric and neurological diseases. The strength of evidence varies for schizophrenia, autism, Parkinson's disease, amyotrophic lateral sclerosis, Alzheimer's disease, and is especially strong for MS"

Research
Willis et al 2010 conducted a serial cross-sectional study of US PD patients who were Medicare beneficiaries aged 65 and over. Using over 450,000 Parkinson’s disease cases per year, they calculated Parkinson’s disease prevalence and annual incidence by race, age, sex, and county.

They found that over the 10 year period from 1995 to 2005 the incidence and prevalence of PD was stable. The overall prevalence among people aged 65 and over was 1.6%. Prevalence increased with age with no sign of a plateau. The highest prevalence was for white males and the lowest for Asian females. White people stood a 50% greater chance of contracting the disease than blacks or Asians. The incidence and prevalence of the disease in the Midwest- and Northeast regions was 2 to 10 times higher than in the Western and Southern counties. Prevalence was greater in urban than rural environments.

The relevance of this to Vitamin D is the indication that latitude and skin colour might be implicated as causative factors.

de Pedro-Cuesta et al 2009 plotted the prevalence of PD in Spain. The resultant map showed a notable similarity to the one prepared by Willis et al for the United States, with a marked gradient running from north to south.

Alaska has to endure a long, dark, Arctic winter and has therefore an interest in settling the matter. The index to the Vitamin D wiki links the compound to almost every known disease and it will be of no surprise to find that Parkinson’s Disease is listed. .

Is there any scientific evidence to support the contention?

Wermouth et al (2004) noted the high incidence of PD in the Faroe Islands (209 per 100,000 inhabitants) and in Greenland (187.5 per 100,000 inhabitants).

The hypothesis that Vitamin D deficiency and PD might be connected was proposed by Newmark and Newmark (2007), and states:-

"We hypothesize, based upon several lines of evidence, that documented chronically inadequate vitamin D intake in the United States, particularly in the northern states and particularly in the elderly, is a significant factor in the pathogenesis of PD. This hypothesis implies that dietary aid for prevention and therapy for PD is possible."

Vitamin D deficiency diseases are also of concern to the people of Finland. A Health Survey, Knecht et al (2008) was conducted in 1997/98 and a cohort of 3,173 people between the ages of 59 and 79 years and free of PD selected for a follow-up survey. During the next 29 years 50 of them were diagnosed with PD. Frozen serum samples taken at the baseline date were then assessed for Vitamin D levels. A key paragraph in the paper is:-

The vitamin D receptors and an enzyme responsible for the formation of the active form 1,25-hydroxyvitamin D have been found in high levels in the substantia nigra, the region of the brain affected most by Parkinson disease.

This raises the possibility that chronic inadequacy of vitamin D leads to the loss of dopaminergic neurons in the substantia nigra region and further Parkinson disease.

The conclusions of the study were:-

''Individuals with higher serum vitamin D concentrations showed a reduced risk of Parkinson disease. The relative risk between the highest and lowest quartiles was 0.33 (95% confidence interval, 0.14-0.80) after adjustment for sex, age, marital status, education, alcohol consumption, leisure-time physical activity, smoking, body mass index, and month of blood draw. The results are consistent with the suggestion that high vitamin D status provides protection against Parkinson disease. It cannot, however, be excluded that the finding is due to residual confounding and further studies are thus needed.''

Evatt et al 2008 selected three cohorts – 100 with PD, 100 with AD and 100 without either. They found that more than half of the PD participants (55%) had vitamin D insufficiency compared with approximately a third of the controls. ‘Vitamin D insufficiency’ was defined as less than 30 nanograms per millilitre of blood of the 25-hydroxy form (the major storage form) of the vitamin and ‘deficiency’ as less than 20 nanograms per millilitre.

Their report states:-

''The prevalence of vitamin D deficiency (25[OH]D, <20 ng/mL) in our PD cohort (23%) was slower than that previously observed in a Japanese PD cohort (50 of 71 patients with PD[85%]). Both insufficiency (36%) and deficiency (10%) in our control cohort were also less prevalent than reported in controls from a study of prostate cancer risk 20 (58% insufficient[<32 mg/mL] and 16% deficient [<20 ng/mL]). Because all our study participants resided in southern latitudes and were predominantly white and a greater proportion of our samples were collected in the summer to fall, a lower prevalence of hypovitaminosis D in all our cohorts is not unexpected. Also, the Japanese participants were drawn from a hospital population, whereas participants in this study were recruited from an outpatient clinic. Previous studies indicate that hospitalized patients have lower mean vitamin D levels than age matched participants recruited from the community. The higher prevalence of insufficiency in the PD cohorts compared with the control cohort is not unexpected given that PD may cause patients to have decreased activity levels and lower sunshine exposure.''

Evatt et al 2011 tested whether or not the high prevalence of Vitamin D deficiency in PD patients was the result of having a chronic disease causing reduced mobility. They examined 157 diagnosed PD patients in the early non-disabling stags of the disease. Their finding was :-

''The prevalence of vitamin D insufficiency in patients with early PD was similar to or higher than those reported in previous studies. Vitamin D concentrations did not decline during progression of PD.''

Collectively these findings mirror the analysis carried out by Simpson et al (2011) who demonstrated a clear relationship between the prevalence of multiple sclerosis and latitude, which they attributed to Vitamin D creation.

Ramagopalan et al 2010 published the results of a genomic study of Vitamin D.  They used new DNA sequencing technology to create a map of vitamin D receptor binding across the human genome. The vitamin D receptor is a protein activated by vitamin D, which attaches itself to DNA and thus influences what proteins are made from the genetic code.

They found 2,776 binding sites for the vitamin D receptor along the length of the genome. These were unusually concentrated near a number of genes associated with susceptibility to autoimmune conditions such as MS, Crohn's disease, systemic lupus erythematosus (or 'lupus') and rheumatoid arthritis, and to cancers such as chronic lymphocytic leukaemia and colorectal cancer.

They also showed that vitamin D had a significant effect on the activity of 229 genes including IRF8, previously associated with MS, and PTPN2, associated with Crohn's disease and type 1 diabetes.

The results appear to show that Vitamin D deficiencies coupled with variations in an individual’s genetic make-up have the capacity to initiate a number of sporadic disease conditions. 20 Vitamin D receptors were identified which had previously been shown by gene associaton tests to have a high risk for PD.

Derex and Trouillas 1997 describe the case of a 50 year old man who had been diagnosed with Parkinson’s Disease 13 years previously.

The disease had progressed to the point where he was admitted to hospital. His symptoms included “a slate of akinetic mutism, deep hypokinesia, masklike facies, extreme rigidity, inexhaustible blink reflex, and permanent severe resting tremor of four limbs.” The paper goes on to describe the treatment and outcone.

After the addition of 25-(OH) vitamin D3 (4,000 1U daily) and calcium supplements (1 g daily) to the ongoing conventional anti parkinsonian therapy, serum and urinary calcium and phosphorus values progressively normalized as well as serum 25-(OH) and 1,25-(OH)T vitamin D,.

''The parkinsonism improved significantly during, the following year with decreased rigidity and akinesta and the antiparkinsonian drugs could be restricted to levodopa 375 mg daily. At 1-year follow-up, neurological examination revealed moderate rigidity without tremor.''

2012

Gordon, P.H. et al calculated the prevalence of PD among American Indians and Alaskan Natives using data from 2002 to 2009. They found a crude prevalence of 143.8/100,000 – much higher than the national average. Prevalence increased with age through 84 years. The age-adjusted rate was 355.7 and was higher among men than women.

Khan and Lan evaluated the role of Vitamin D in Parkinson’s disease.

''Recent studies have highlighted a possible relationship between vitamin D and PD. Vitamin D may be beneficial in PD patients, as one patient showed improved rigidity and akinesia and was able to decrease their levodopa dosage after vitamin D therapy. Genetic studies have provided opportunities to determine what proteins may link vitamin D to PD pathology. Vitamin D can also act through a number of nongenomic mechanisms, including effects on protein expression, oxidative stress, inflammation, and cellular metabolism. Among the many forms of vitamin D, calcitriol (1,25-dihydroxyvitamin D3) is an attractive therapeutic candidate, because it is a particularly active metabolite, and its receptor is expressed in the CNS. ''

Summary
There is a growing number of indications that Vitamin D deficiency and the incidence and prevalence of Parkinson’s Disease are linked, but there is some polarisation of views as to whether this is a cause or an effect. To try to settle the matter a clinical study has been initiated by the Department of Veteran Affairs (USA), commencing in 2011 with the recruitment of a substantial cohort of PD patients. Participants will be given Vitamin D supplements or placebos and measurements taken of balance, gait, falls, strength, and cognition. The results are due to be published in 2015.

Further Reading and Viewing
< Outdoor Trades much less likely to get Parkinson disease http://www.vitamindwiki.com/tiki-index.php?page_id=1027>

< Video Dr. Marion Evatt on the relationship of Vitamin D levels to skin colour and latitude. http://www.youtube.com/watch?NR=1&v=adBTOTeFUjI>

< Video Dr. Marion Evatt on Finnish studies of Vitamin D.http://www.youtube.com/watch?v=WlG3fOdvPmw>

< Video Dr. Hollick on Vitamin D deficiencies.http://www.youtube.com/watch?v=9HHK6SAehzU>

< Video Dr. Cannell on recent Vitamin D research http://www.youtube.com/watch?v=sNIiNQ1AG9s>

< Press ReleaseDigital Journal 29 May 2014  Is inadequate Vitamin D implicated in Fibromyalgia, Multiple Sclerosis and Parkinson's?   http://www.digitaljournal.com/pr/1946966

 Further Research

Related Pages
Vitamin D,


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Progress and Prospects in Parkinson's Research/Therapy/Neuroprotection/Neuroprotective agents

"Very many compounds are being explored for their potential neuroprotective properties. Finding one that was truly effective in preventing or slowing down Parkinson's would represent a major breakthrough. The sub-pages in this Neuroprotection section report on research on the following substances:"

More candidate neuroprotective agents
"This page can also be used for references to new neuroprotective agents that could be expanded on in subpages to be developed later."

Rescue of PD-infected yeast cells by four compounds found by screening 100,000 compounds
Su et al carried out a series of experiments using genetically modified yeast.

They modelled many of the features of alpha synuclein pathology observed in PD cases. They identified the YPK9 gene, which is the yeast homolog of PARK9/ATP13A2, as a suppressor of α-synuclein toxicity, were able to reproduce abnormalities in mitochondria observed in PD affected nigral neurons and established that:-

"mitochondrial dysfunction elicited by α-syn is not due to specific mislocalization to mitochondria through a cryptic signalling sequence. Rather, it is the perturbation of other cellular pathways impinged on by α-synuclein that leads to mitochondrial dysfunction and the generation of reactive free radicals."

They then carried out a high-throughput chemical screen to identify single agents that might be capable of rescuing the robust toxicity of this strain using a library of 115,000 small compounds. To score positive in the screen, the compounds needed to be able to (1) enter cells, (2) avoid clearance by core metabolic pathways, (3) alleviate α-syn toxicity without causing toxicity on their own at the screening concentration and (4) protect against at least two different features of α-synuclein toxicity within the HiTox cells.

Four compounds were identified that met these criteria.

The compounds were then used to treat PD-infected nematode worms and were found to rescue their affected nigral neurons.

"It is remarkable that brief treatment of adult worms with these compounds was neuroprotective well after the onset of α-synuclein expression, revealing that it is possible to arrest cell death even after the onset of toxicity."

The treatment was then tried out on mammalian cells using PD-infected neurons harvested from the embryos of rats and three of the compounds rescued these cells. Successful reversal of PD induced toxicity was achieved using cells that had been infected with rotenone.

Further results from this lab should be looked for and reported here or on a subpage as it emerges.

Anle138b - oligomer inhibitor
Wagner et al report an important breakthrough in the search for disease-modifying therapy for Parkinson’s and other neurological disorders. Parkinson’s disease is characterised by the formation of aggregates of the protein α-synuclein in the brain. Such oligomeric aggregations are presumed to be the key neurotoxic agents. In an article published on-line on 19 April 2013, in the journal Acta Neuropathologica, the research team describe work on Anle138b, an oligomer modulator, showing that in three different mouse models of PD, it strongly inhibits oligomer accumulation, neuronal degeneration and disease progression. Furthermore it has no detectable toxicity at therapeutic doses and an excellent bioavailability and blood-brain-barrier penetration.

This work needs to be monitored and reported on in a subpage as further results emerge.


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Progress and Prospects in Parkinson's Research/Therapy/Neuroprotection

< Back to: Therapy

While at present there are no substances that have proven neuroprotective properties for the treatment of Parkinson's, a number of substances and strategies are being researched with indications that it may be possible to slow down or halt the pathogenic process. A recent trial of Exendin-4, a drug already used for the treatment of diabetes, is an example of this. Almiles-Olmes, Iciar; Dickson, John; Kefalopoulou, Zinovia; Djamshidian, Atbin; Ell,Peter; soderlund,Therese; Whitton, Peter; Wyse, Richard; Isaacs, tom; Lees,Andrew; Limousin, Thomas and Foltynie (2013)  Full Text J.  Clin. Invest. doi:10.1172/JCI68295. Exenatide and the treatment of patients with Parkinson’s disease http://www.jci.org/articles/view/68295

See notes on page development on Talk page

Definition
‘Neuroprotection’ can imply that there are therapies which inhibit neurodegeneration from taking place. Alternatively, in cases where someone has been diagnosed as having a neural deficit, it means that the condition can be prevented from worsening. Either way it presents the researcher with the problem of proving a negative, i.e. of showing that something which would otherwise have happened did not happen.

This can be avoided in tests in vitro or with fast breeding animal models, but can present difficulties in assessing humans

One way of doing this is to collect information on a large group of people, to monitor their health over an extended timescale, and to identify differences between those that acquire a degenerative condition and those that do not. Distinctions may be made for gender, ethnicity, age, nutrition, location, diet, genetics, medical history and lifestyle choices.

Another is to assemble cohorts of patients and controls and get them to complete questionnaires deigned to isolate significant differences between the two groups.

The results obtained by both methods are questionable, but gain strength when repeated studies show the same result.

If the risk to patients is deemed minimal research can proceed to Clinical Trials, where cohorts of patients are given controlled amounts of medication and the effect on their disease is measured against a second cohort given a placebo.

Introducing new therapies
The process of proving a new therapy generally follows a set sequence:-

 * tests on cells in dishes (in vitro);

 * tests on laboratory animals with induced forms of the target disease;(in vivo)

 * tests on patients, generally involving larger and larger cohorts, with time to assess long term side effects and outcomes.

It is valuable if results can be corroborated at each stage by more than one independent project team.

Delays can occur for a number of reasons:-

 * obtaining the necessary funding for each stage in the process;

 * optimising the capabilities, experience and facilities of the laboratory;

 * the priorities assigned to unrelated projects:

 * maintaining continuity of staff and expertise.

Assuming that results arrive at a satisfactory outcome there are three more hurdles to overcome:-

 * publishing the results in a peer-reviewed scientific journal. As a general rule the more prestigious is the journal, the more stringent the review criteria and the longer the lead time on publication.

 * making a sound business case and carrying out a risk analysis by drug manufacturers in competition with other diseases.

 * meeting the requirements of national drug licencing bodies,

Parkinson's Disease tends to fare badly in this process because:-

 * There is no clinical diagnostic test for the disease.
 * There are not enough diagnosed cases compared to other diseases to justify a large investment in research.
 * The disease is idiosyncratic - patients have differing symptoms, rates of deterioration and varying responses to drugs, making 'one-size-fits-all' remedies harder to develop.
 * palliative drugs such as levadopa, which have to be taken continually in large quantities,have a greater potential profit margin than drugs which might reverse the symptoms.

It is not surprising then that many a promising hypthesis does cross the therapeutic boundary from academic research to commercial production. Contributors to patient forums show frustration at the slow progress of research and a willingness to self-medicate or experiment with alternative medicine.

Current Research
Of the recent research described in the following pages Rasagaline and Tolcapone have completed the research sequence and are prescribed. NSAIDs, Creatine and Vitamin D are available over the counter and Melatonin can be purchased via the internet.

2011

Seidl and Potashkin   Seidl,Stacey E. And Potashkin, Judith A. (2011) Full Text Front. Neurol. 2:68

The Promise of Neuroprotective Agents in Parkinson’s Disease

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3221408/ evaluated a number of promising potential neuroprotective agents

Boll et al Boll, Marie Catherine; Zubeldia,Mireya Alcaraz and Rios, Camilo (2011) Full Text: Curr. Neuropharmacol. 9 (2) 350 -359 Medical Management of Parkinson’s Disease: Focus on Neuroprotection.  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131725/?tool=pmcentrez  summarized the current PD neuroprotection scene

Detail of individual agents are given in the following pages and readers are invited to update these as more research comes to light.


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Problem Statement
Find n sufficiently high so that $$y_n(x_1), y'_n(x_1)$$ do not differ from the numerical solution by more than $$10^{-5}$$ at $$x_1=0.9$$

Solution
Using a program in MATLAB that iteratively added terms onto the taylor series of $$log(1+x)$$, terms were added until the error between the exact answer and the series was less than $$ 10^{-5}$$.

It was found after trial and error that $$ n=39 $$ for the error to be of a magnitude of $$ 10^{-5}$$. This error found was 9.7422e-005

Similarly, for $$y'_n(x_1)$$.

It was found after trial and error that $$ n=74 $$ for the error to be of a magnitude of $$ 10^{-5}$$. This error found was 9.3967e-005

Problem Statement
Develop $$log(1+x)$$ in Taylor series about $$\hat{x}=1$$ for $$ n=4,7,11$$ and plot these truncated series vs. the exact function. What is now the domain of convergence by observation?

Solution
A MATLAB program was created, which calculated the Taylor series of each n value, along with the exact function, then plotted these together to show the comparison of all the series. Below is the Taylor series for $$n=7$$ expanded at $$\hat{x}=1$$. $$\frac{x - 1}{2\, \ln\!\left(10\right)} - \frac{{\left(x - 1\right)}^2}{8\, \ln\!\left(10\right)} + \frac{{\left(x - 1\right)}^3}{24\, \ln\!\left(10\right)} - \frac{{\left(x - 1\right)}^4}{64\, \ln\!\left(10\right)} + \frac{{\left(x - 1\right)}^5}{160\, \ln\!\left(10\right)} - \frac{{\left(x - 1\right)}^6}{384\, \ln\!\left(10\right)} + \frac{\ln\!\left(2\right)}{\ln\!\left(10\right)} $$

It can be seen by observation that the domain of convergence has shifted to the right one unit. --egm4313.s12.team11.gooding (talk) 03:48, 14 March 2012 (UTC)


text:
University of Florida/Egm4313/s12.team11.perez.gp/R4.1

Problem Statement
Obtain equations (2), (3), (n-2), (n-1), (n), and set up the matrix A as in (1) p.7-21 for the general case, with the matrix coefficients for rows 1, 2, 3, (n-2), (n-1), n, filled in, as obtained from equations (1), (2), (3), (n-2), (n-1), (n).

Given
As shown in p.7-21, the first equation is:

$$ 2C_2+ac_1+bc_0=d_0 \! $$ (1) p.7-21

According to p.7-20, the general form of the series is:

$$ \sum_{j=0}^{n-2}[c_{j+2}(j+2)(j+1)+ac_{j+1}+bc_j]x^j+ac_nnx^{n-1}+b[c_{n-1}x^{n-1}+c_nx^n]=\sum_{j=0}^{n}d_jx^j \! $$ (2) p. 7-20

From (2) p.7-20, we can obtain n+1 equations for n+1 unknown coefficients $$ {c_0,..., c_n} \! $$.

After referring to p.7-22, it can be determined that the matrix to be set up is of the following form:

$$ A =\begin{bmatrix} X && X && X && 0 && 0 & 0\\ 0 && X && X && 0 && 0 & 0\\ 0 && 0 && X && 0 && 0 & 0\\ 0 && 0 && 0 && X && X & X \\ 0 && 0 && 0 && 0 && X & X\\ 0 && 0 && 0 && 0 && 0 & X \end{bmatrix} \! $$

where the rows signify the coefficients $$ c_0, c_1, c_2, c_{n-2}, c_{n-1}, c_n \! $$, and the columns signify $$ d_0, d_1, d_2, d_{n-2}, d_{n-1}, d_n \! $$.

Solution
Building the coefficient matrix as shown in p.7-22 of the class notes, we can begin to solve for the coefficients as follows:

Equation associated with $$ d_0 \! $$:

j=0: $$ d_0=2C_2+ac_1+bc_0 \! $$ (1)

Equation associated with $$ d_1 \! $$:

j=1: $$ d_1=6c_3+2ac_2+bc_1 \! $$ (2)

Equation associated with $$ d_2 \! $$:

j=2: $$ d_2=12c_4+3ac_3+bc_2 \! $$ (3)

Equation associated with $$ d_{n-2} \! $$:

j=n-2: $$ d_{n-2}=[c_n(n)(n-1)+ac_{n-1}(n-1)+bc_{n-2}] \! $$ (n-2)

Equation associated with $$ d_{n-1} \! $$:

j=n-1: $$ d_{n-1}=ac_nn+bc_{n-1} \! $$ (n-1)

Equation associated with $$ d_n \! $$:

j=n: $$ d_n=bc_n \! $$ (n)

Using all of the above equations, (1), (2), (3), (n-2), (n-1), (n), we can then determine the A matrix to be:

$$                              A =\begin{bmatrix} b && a && 2 && 0 && 0 & 0\\ 0 && b && 2a && 0 && 0 & 0\\ 0 && 0 && b && 0 && 0 & 0\\ 0 && 0 && 0 && b && a(n-1) & n(n-1) \\ 0 && 0 && 0 && 0 && b & an\\ 0 && 0 && 0 && 0 && 0 & b \end{bmatrix} \! $$


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