text:
Radiation Oncology/RT Techniques

Radiation Therapy Treatment Techniques

 * External Beam
 * Cranial stereotactic radiosurgery (SRS)
 * Stereotactic body radiation therapy (SBRT)
 * Whole brain RT (WBRT)
 * Cranio-Spinal Irradiation (CSI)
 * Total Body Irradiation (TBI)
 * Total Marrow Irradiation (TMI)
 * Total Scalp Irradiation (TSI)
 * Total skin electron beam therapy (TSEBT)
 * Three-dimensional conformal radiation therapy (3DCRT)
 * Intensity modulated radiation therapy (IMRT)

 * Image-guided radiotherapy (IGRT)
 * Volumetric modulated arc therapy (VMAT)
 * Helical Tomotherapy
 * Adaptive radiotherapy
 * FLASH radiotherapy (FLASH-RT)
 * /Superficial x-ray radiation therapy (SXRT)/
 * Brachytherapy
 * Image-Guided Brachytherapy (IGBT)
 * Intraoperative RT (IORT)
 * Unsealed sources
 * Radioimmunotherapy
 * Protons
 * Intensity Modulated Proton Therapy (IMPT)
 * Image-Guided Proton Therapy (IGPT)
 * Radiation Oncology/Protons/Proton Boron Capture Therapy (PBCT)
 * Proton Boron Fusion Therapy (PBFT)
 * Heavy Charged Particles
 * Pion Therapy
 * Neutrons
 * Boron Neutron Capture Therapy (BNCT)
 * Accelerator-Based BNCT (AB-BNCT)
 * Reactor-Based BNCT (RB-BNCT)
 * Gadolinium Neutron Capture Therapy (GdNCT)
 * Hyperthermia
 * Hyperbaric Oxygen
 * Photodynamic Therapy (PDT)
 * /High-Intensity Focused Ultrasound (HIFU)/
 * /Radiofrequency Ablation (RFA)/
 * /Cryotherapy/
 * /Laser Therapy/
 * Immobilization devices
 * Virtual Reality

title: Radiation Oncology/RT Techniques


text: User talk:217.64.29.200

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: User talk:217.64.29.200


text:
User:Guaka/hebrew

Some slang in Hebrew

 * bastard - מניאק maniak

 * son of a bitch - בן זונה ben zona

 * pussy - כוס kus

 * cock - זין zain

 * the best (litt: the end of the road) - סוף הדרך  sof haderech

 * the best, really great, not a waste of time (litt: a waste of time)  חבל על הזמן  chaval al hazman

title: User:Guaka/hebrew


text:
User talk:Permag~enwikibooks

Welcome message
Welcome, Permag!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 09:11, 13 April 2008 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Permag. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Permag~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:34, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 05:22, 19 April 2015 (UTC)

title: User talk:Permag~enwikibooks


text:
User talk:Nagyv

Welcome message
Welcome, Nagyv!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 09:12, 13 April 2008 (UTC)

title: User talk:Nagyv


text:
Talk:Embedded Control Systems Design/Learning from failure

Possible Improvements
Interesting article, but riddled with grammatical errors and a few technical inaccuracies. Patriot's problem had nothing to do with a missile - none were launched, because the target had been lost. And in the Mars article, priority inversion protection doesn't lead to all threads having elevated priorities, because in any correctly implemented priority promotion scheme, threads which are no longer contributing to the inversion get set back down to their original priority.

It's important to document these kinds of failures, but this needs to be tightened up. 199.46.198.230 (discuss) 15:55, 15 March 2012 (UTC)

Other Examples
Other interesting examples that can be treated in this section are: Wannes (talk) 10:14, 13 April 2008 (UTC)
 * The Patriot Missile Failure
 * Ariane 5
 * ParkShuttle: An automated peoplemover. This would be in line with the design example

 * You might also want to reference The Risks Digest, which regularly covers such failures. Webaware talk 10:18, 13 April 2008 (UTC)

The Wikipedia article on priority inversion has a failure example with the Mars rover Pathfinder. Bruyninc (talk) 07:04, 19 April 2008 (UTC)


text:
User:M-streeter97~enwikibooks

= GNU Free Documentation License = GNU Free Documentation License

Jet Black

title: User:M-streeter97~enwikibooks


text:
User talk:M-streeter97~enwikibooks

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called M-streeter97. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name M-streeter97~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:27, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 05:13, 19 April 2015 (UTC)

title: User talk:M-streeter97~enwikibooks


text: Template:Spanish/ES-grammar

title: Template:Spanish/ES-grammar


text:
User talk:Amie rice

Welcome message
Welcome, Amie rice!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 13:49, 13 April 2008 (UTC)

title: User talk:Amie rice


text:
Template:Bluedrop

Uses
The control is used mainly for text, though it can hold an image. An example of its use and the result is:

Limitations
If a table is used as the content, it should be an HTML table to avoid confusion over pipe symbols.

Table Level Options

 * tbgc:  table background color, grey
 * tha:  position on page, left
 * tw:  width, 300px
 * tb:  table border,1px double dimgray

Heading Level Options

 * hbgc: background color,grey
 * hfc:  font color, black
 * hp:  padding, 5px
 * hff: font family, Arial
 * hfs: font size, 10pt

Content Level Options

 * cbgc: background color,light blue
 * cfc:  font color, black
 * cp:  padding, 10px
 * cff: font family, Arial
 * cfs: font size, 10pt
 * clh: line height, 1.5em
 * cm:  margin, 10px
 * cb:  border, 1px solid lightgray
 * chta: text alignment, justify

title: Template:Bluedrop


text:
Talk:XForms/Folding Menus

This example doesn't work ! --Dom (talk) 14:37, 13 April 2008 (UTC)
 * I was using Firefox 2.0.0.7 with XForms module 8.5 --Dom (talk) 18:26, 21 April 2008 (UTC)

title: Talk:XForms/Folding Menus


text:
User talk:89.205.5.236

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
 * The use of a username of your choice
 * The ability to view all your contributions via a "My contributions" link
 * Your own user page
 * Your own talk page which, if you choose, also allows users to send you messages without knowing your e-mail address
 * The use of your own personal watchlist to which you can add articles that interest you
 * The ability to rename pages.
 * The ability to upload images
 * The ability to customize the appearance and behavior of the website
 * The eligibility to become an administrator
 * The right to be heard in votes and elections
 * Your IP address will no longer be visible to other users.

We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

Νεοπτόλεμος ( talk | email | contribs ) 15:47, 13 April 2008 (UTC)

title: User talk:89.205.5.236


text:
Macedonian/Dialects

Dialects
Based on a large group of features, the Macedonian dialects can be divided into Eastern and Western groups (the boundary runs approximately from Skopje and Skopska Crna Gora along the rivers Vardar and Crna). In addition, a more detailed classification can be based on the modern reflexes of the Proto-Slavonic reduced vowels ("yers"), vocalic sonorants and the back nasal (o). That classification distinguishes between the following 5 groups :

Western Dialects:

 * Ohrid - Prespa Group consisting of the Lower Prespa region, Ohrid, Struga, Radožda and Vevčani.
 * Debar Group consisting of the Drimkol - Golobrdo region, Debar, Mala Reka, Reka, Gora, and Skopska Crna Gora.
 * Polog Group consisting of Gostivar (Upper Polog), and Tetovo (Lower Polog), as well as the entire West Central region (Prilep, Kičevo, Bitola, Kruševo, Florina/Lerin)
 * Kostur - Korča Group consisting of KorçNestorioë (Korča), Kastoria (Kostur), and Nestorio (Nestram).

Eastern Dialects:

 * Eastern Group consisting of the entire eastern part of the Macedonian region including the Kumanovo - Kriva Palanka, Štip - Strumica, Tikveš - Mariovo, Maleševo - Pirin, Lower Vardar (Kilkis/Kukuš, Edessa/Voden-Pella/Postol, Thessaloniki/Solun), and the Serres/Ser - Gotse Delchev/Nevrokop subregions.

It must be noted that the Ser-Nevrokop group is in fact located mostly outside of the Republic of Macedonia (in Greece and Bulgaria, respectively) and hence its identification as a group of "Macedonian" dialects is an especially controversial issue. Bulgarian linguists regard both as East Bulgarian dialects, more specifically as part of a Rupski dialect group that stretches through Southern Thrace up to the Black Sea. In Greece, all Slavic varieties spoken in the northern part are referred to simply as slavic, except the local Macedonian population does call their local language "Makedonski"

Variation in vowels
The vocalic inventories of the West Central dialects consist of five vowels,. Most of the remaining dialects also have phonemic. In addition, phonemic, , and and vocalic  and  occur in various dialects.

Most dialects have from original ě (yat), but the Eastern region is characterised by the development of ě to  after : Eastern cal, Western cel (whole). Besides that, in easternmost Aegean Macedonia and the Blagoevgrad Province of Bulgaria ě gives or  under stress. In the dialects of Aegean Macedonia, this happens regardless of the environment, whereas the dialects of the Blagoevgrad province have (just like standard Bulgarian and its eastern dialects) if there is a back vowel in the following syllable, and  if there is a front vowel. For example, 'white' (sing. - plur.) sounds in the following way in these dialects: Serres-Drama: -, Suho and Visoka:  - , Nevrokop:  -. In Korca, ě becomes under stress.

Variation in consonants
As far as consonantal features are concerned, the entire Western region is distinguished from the East by loss of (except Tetovo, Gora and Korča) and the loss of  in the intervocalic position (except Mala Reka and parts of Kostur-Korča):  (head) =,  (heads) =. The Eastern region preserves (except Tikveš-Mariovo and Kumanovo-Kriva Palanka) and intervocalic. The East is also characterised by the development of epenthetic before original  where the West has epenthetic : Eastern  (coal) but Western. The diphonemic reflexes are most characteristic of the dialects of Aegean Macedonia and Blagoevgrad province, Kostur-Korča and Ohrid-Prespa. The Serres-Nevrokop dialects have a series of phonemically palatalised consonants.

Variation in word stress and its effects on vowels
The Western dialects generally have fixed stress, antepenultimate in the Republic of Macedonia, and penultimate in Greece and Albania. The Eastern region, along with the neighbouring Bulgarian dialects, has various non-fixed stress systems. In Lower Vardar and Serres-Nevrokop unstressed are reduced (raised) to. The reduction of unstressed vowels (as well as the aforementioned allophonic palatalisation of consonants) is characteristic of East Bulgarian as opposed to West Bulgarian dialects, so these dialects are regarded by Bulgarian linguists as transitional between East and West Bulgarian ..

title: Macedonian/Dialects


text:
User talk:L.djinevski

Welcome to Wikibooks, L.djinevski!

title: User talk:L.djinevski


text:
XRX/Dictionary Editor

Motivation
You want a simple application that saves one XML file per form. You want multiple users to each be editing individual records without conflict.

Design
We will put each term in a separate XML file, and the files will be numbered sequentially - 1.xml, 2.xml, and so on. Each file defines a single term, its acronym, and its definition.

Method

 * 1) Create a new eXist collection (aka Folder if you are using a WebDAV tool) called "dictionary"
 * 2) Create three collections called "data", "edit", and "views" within the "dictionary" collection.

data/2.xml
Your XForms application loads the data into an instance:

You pass the ID number to an XQuery "edit.xq" as a parameter in the URI, "id". "edit.xq" uses the ID parameter as a variable, "$id", to build the form.

Contents of edit/edit.xq
--- calling format: edit.xq?id=1 ---

Contents of views/list-terms.xq
As you save more and more terms, you will want to create a list of them. You can create an XQuery that list all terms. For each term you can include a link to view and edit each term.

edit.xq Header
The edit.xq takes parameters from the URI (i.e. in the form "edit.xq?id=2") and either puts a new element in the instance or it puts an existing element in the instance.

xforms.css
The following file can be linked into the form for formatting. [And which file might that be?]

Back: Configuration File Editor • Next: Regular Expression Builder

title: XRX/Dictionary Editor


text:
User:Quanticles

Please see http://en.wikipedia.org/wiki/User:Quanticles

title: User:Quanticles


text: User talk:76.67.2.104

title: User talk:76.67.2.104


text: Category:Book:Welsh

title: Category:Book:Welsh


text:
A-level Mathematics/MEI/S1/Discrete Random Variables

Discrete Random Variables
Discrete random variables are the models for the probabilities of particular results. They are represented by the notation, $$P(X = R)$$ (Where P is the probability of the Discrete Random Variable, X, taking on the result, R.). A discrete random variable can only take on the values r1,r2,r3...rn with the probabilities p1, p2, p3...pn respectively. Discrete random variables allow us to produce a Discrete Frequency Distribution. Discrete meaning that the value of the results can only take on positive whole integers. In S1, Discrete distributions are limited to a finite number of outcomes.

Exemplar Question
Questions often involve working with algebra in order to find the probabilities, in OCR(MEI), you will often have to work out the value of k in order to work out the probabilities.

'''The probability distribution of a discrete random variable, X, is given by

$$P(X = R) = \frac {kr}{8} R = 2, 4 ,6 ,8. $$  Find the value of k and tabulate the probability distribution.'''

To find the value of k, we need to tabulate our probabilities and substitute the values of R into the discrete random variable, X.

R || 2 | 4 | 6 | 8 || p(x=R)|| $$\frac {k2}{8}$$


text:
General Chemistry/Introduction to Kinetics

Chemical kinetics is the study of the rates of chemical reactions. You may know if a reaction is capable of happening, and you may know how far the reaction will proceed, but you don't know fast it will happen. Consider two reactions: the rusting of an iron nail and the combustion of propane. Both reactions will occur, and both will occur to completion. The rusting will take years to complete, but propane will combust in an instant. Furthermore, the nail will rust faster when it's moist, and slower in the presence of less oxygen. Obviously, there are factors that affect the rates of chemical reactions. The study of these factors and rates is chemical kinetics.

Reaction Rate
In summary, the reaction rate can be determined using a rate equation, which depends on (among other things) the concentration of the reactants. The reaction rate essentially measures the speed at which a reaction proceeds.

Collision Theory
Collision theory predicts that reactions occur when molecules collide. In order for reactants to form products, the reactant molecules must physically collide so that they can rearrange themselves into product molecules. Only some collisions are effective because the collision must involve enough energy to allow the reaction to occur. This is called activation energy, the energy needed to begin a reaction.

Activation energy explains why gasoline will not spontaneously ignite. First, a small spark or flame must be present. The heat generated by the spark gives the gasoline molecules enough energy to activate the reaction. Being highly exothermic, the combustion of gasoline releases a large amount of heat—more than enough to activate further reactions and create a fire.

Collision theory allows us to predict the rate constant $$k$$ for a rate equation (see above). At a given temperature $$T$$, the rate constant is: $$k = Z \rho e^{-E_a / (RT)}$$, where $$R$$ is the Universal Gas Constant, $$E_a$$ is the activation energy for the reaction, $$\rho$$ is a predicted-to-actual correction factor, and $$Z$$ is the collision factor. The collision factor can also be calculated mathematically. It is the average number of reactant particle collisions per unit time.

Factors Affecting Rate
The rate of a reaction is affected by many factors. These effects can be measured empirically or explained by collision theory.

Concentration
This is the most obvious factor affecting rate. Increasing the concentration of the reactants will increase the rate they react. This is the main purpose of writing a rate equation; the concentrations can be plugged in like variables and the rate can be solved mathematically. In a rate equation in the form $$r = k[\hbox{A}]^a[\hbox{B}]^b$$, the concentrations are the variables (raised to the powers of their coefficients in the reaction). All other factors that can affect rate are lumped into $$k$$, which is considered a constant.

Collision theory explains this. Higher concentrations means more molecules packed into a given space. Therefore, there will be more collisions and thus a faster reaction.

Pressure
In a reaction of gaseous reactants, the partial pressure of the gases has the same function as the concentration.

However, increasing the overall pressure (or decreasing the volume if you remember the gas laws) will also result in a greater reaction rate. The increased pressure causes the molecules to collide with more force. More collisions will be effective and therefore products will form faster.

Temperature
As you should already know, a molecule's kinetic energy is directly proportional to its temperature. By increasing the temperature, molecules collide more vigorously, and more collisions will be effective.

Stirring
In a heterogeneous reaction there are two or more phases of matter interacting, such as a solid dissolving into a liquid. Stirring or shaking the mixture will speed up the reaction rate. This is common sense. When you add sugar to a drink, you stir it because you know it will dissolve faster. Collision theory would predict this because the stirring would increase the number of collisions between reactant molecules.

In a similar manner, increasing the surface area of a solid reactant will increase the reaction rate.

Catalysts/Enzyme

A catalyst is a substance that helps a reaction proceed without being consumed. Catalysts have already been explored in this book. A Catalyst provides a reaction pathway with lower activation energy.

In biochemistry, an enzyme is a protein that serves as a catalyst.


text:
General Biology/Classification of Living Things/Viruses/Answers

1. No, since viruses target unique glycoproteins. The proteins act as a key and lock.

2. Lysogenic

3. Lysogenic

4. No, because the cold and flu are caused by viruses. Antibiotics are for bacteria.


text:
General Biology/Classification of Living Things/Eubacteria

Introduction
On this page, the Kingdom Eubacteria will be explored. Bacteria are omnipresent; they are in our bodies and in our foods. Bacteria are also prokaryotes; the great majority live as single cells, but they are able to produce colonies or link up in chains to form filaments.

Classifying bacteria
There are numerous ways to classify bacteria.

Shape
Since bacteria typically live by themselves, it is easy to distinguish them based on their shape. Bacterial cells have three main shapes:

1) cocci: round with bumps

2) bacilli: rod-shaped with lacerations

3) spirilli: spiral-shaped with grooves

A bacterium's shape can give the bacterium some advantages. For example, spiral bacteria can move through fluids more easily than can cocci or bacilli bacteria.

Furthermore, bacteria can be classified by their growth characteristic patterns (Groupings). The prefix diplo- denotes cells arranged in pairs. The prefix staphylo- describes bacteria arranged in clusters like grapes. The prefix strepto- denotes bacteria arranged in a chain.

Cell Wall Structure
1) Gram-positive: Gram-positive bacteria have simple cell walls, composed of only one layer of peptidoglycan before the plasma membrane. When stained with violet and red dye, gram-positive bacteria appear purple. Sometimes blue, depending on the temperature. The large amount of peptidoglycan in these bacteria traps the violet dye in the cytoplasm, masking the red dye.

2) Gram-negative: Gram-negative bacteria have more complex cell walls, consisting of one layer of a lipopolysaccharide membrane and a peptidoglycan layer. Gram-negative bacteria appear red.

Carbon and Energy Sources
Organisms need energy to do work and carry out metabolism and carbon to build organic cellular structures.

1) Photoautotrophs - Energy and carbon are both obtained from photosynthesis.

2) Photoheterotophic - Energy is obtained from photosynthesis, but carbon must be obtained from food.

3) Autotrophic - Energy must be obtained from consuming food, while carbon is obtained from photosynthesis.

4) Heterotrophic - Both energy and carbon must be obtained from food.

Asexual reproduction
Typically, bacteria reproduce asexually. They are not able to reproduce by mitosis or meiosis because they lack nuclei. Instead, they undergo binary fission:

1. The bacterium duplicates its original, single chromosome.

2. With two copies of its original, single chromosome, the cell elongates (stretches) to separate the two chromosomes.

3. A septum (divider) begins to form between the two copies of chromosomes.

4. The septum finishes forming and divides the one bacterium in two parts.

5. The bacterium separates into two daughter bacteria.

Sexual reproduction
In unfavourable conditions, bacteria can reproduce sexually through a process of conjugation:

1. A pilus (a bridging structure) forms between two bacteria as a link.

2. One bacterium of the two transfers all or some of its chromosome to the other across the pilus.

3. With the new genetic content, the receiving bacterium then undergoes binary fusion to produce more cells with the same genetic composition.

Spore formation
If the surrounding environment is unfavourable for a bacteria, they may enter a dormant phase so they can protect themselves. In this case, the bacteria develops a tough outer coating surrounding their DNA and a small amount of cytoplasm. This forms small seedlike structures called endospores. The endospores disintegrate when the living environment becomes favourable again.

When bacteria are protected by endospores, they are more difficult to be killed. However, one reliable method is to subject the endospores to an autoclave, a container which contains highly pressurised steam.

Genetic Recombination
The genetic composition of a bacteria can be changed in three ways: transduction, transformation, and conjugation. Not all of bacteria's chromosomes are in the nucleoid of bacteria. Some of the bacteria's genes are contained in plasmids, which are small loops of DNA which are separate from the main chromosome. They contain one to a few genes, and they are often different from those found in the chromosome.

Transduction
Transduction occurs when a bacteriophage infects a bacterium and injects the phage's nucleic acid into the bacteria. The phage's nucleic acid then becomes part of the bacteria's DNA. For more information, please see the lesson on Viruses: General Biology/Classification of Living Things/Viruses.

Transformation
1. A bacterium encounters DNA from another dead or damaged bacterium.

2. The recipient bacterium accepts the nucleic acid.

3. The recipient and donor DNA are combined.

4. The recipient cell is now genetically different.

Conjugation
Please refer to Sexual Reproduction above.

Bacteria & Human Health
As with most things, there are good and bad bacteria. Some examples of good bacteria are nitrifying bacteria and members of the lactobacillus genus. Harmful bacteria can cause pnuemonia, botulism, infections, and many other diseases in the human body.

To stop unwanted bacteria growth in humans, antibiotics affect bacteria in many ways. Some prevent the bacteria from building or repairing cell walls or membranes, from making more RNA or DNA, or target certain organelles. Antibiotics generally kill bacteria directly or inhibit their growth to let the body's immune system finish the job.

To select the most effective, physicians must apply understanding and knowledge of bacteria. For example, cephalosporin antibiotics are more effective on gram-negative bacteria.

Eubacteria Practice Questions
1. Give two similarities between binary fission and mitosis.

2. Give two differences between binary fission and meiosis.

3. Classify the following as either photoautotrophic, photoheterotrophic, chemoautotrophic, or chemoheterophic:

 * a) sunflower

 * b) goldfish

 * c) human being

 * d) cyanobacteria

 * e) iron-oxidising bacteria

4. Between cocci, bacilli, and spirilli bacteria, which type would resist drying the best?

5. Bacteria can help other bacteria resist antibiotics by sharing genetic information.

 * a) In what part of the bacteria would such genetic information be located?

 * b) Which method of genetic transfer would bacteria most likely use for this purpose?

6. Would it be possible for some bacteria to remain in the endospore stage for hundreds of years? Support your argument.

Answers to Eubacteria Practice Questions


text:
Talk:Statistics/Distributions/F

"The mean and variance of the first sample are 124.67 and 16.80 respectively, and of the second sample 102.50 and 16.01." This is not variance, but rather the standard deviation, is it not?

title: Talk:Statistics/Distributions/F


text:
User:Radiomike5

Intro to psych

title: User:Radiomike5


text:
Futurebasic/Language/Reference/filesstr ffolder

Function
✔ Appearance ✔ Standard ✔ Console

Syntax
(See note below.)

Revised:  February 2002 (Release 6)

Description
This function prompts the user to select an existing folder. It does this by displaying the standard "Get File" dialog shown below (its appearance may be different on some systems). If the user selects a folder, then the folder's name is returned in, and a reference number for the folder is returned in   (which must be a short integer variable). If the selected folder is in a volume's root directory, the  will return a volume reference number; otherwise, it will return a working directory reference number. If the user cancels the dialog, then the function returns an empty (zero-length) string, and it sets  to zero.

The information contained in  is the correct name for the folder but is not of any real value except to determine that the user has selected Choose instead of Cancel. Only the volume reference number is necessary when using FB's file handling routines.

If the global variable  is non-zero, FB switches to the more modern Navigation Services dialog. If the FSSpec version of the call is used,  is assumed to be.

Image was here.

Note: If you are programming for Carbon, the  statement is required.


text:
Futurebasic/Language/Reference/filesstr fopen

Function
✔ Appearance ✔ Standard ✔ Console

Revised
February, 2002 (Release 6)

Description
This function prompts the user to select an existing file. It does this by displaying the standard "Get File" dialog shown below (its appearance may be different on some systems). If the user selects a file, then the file's name is returned in, and a reference number for the file's directory is returned in   (which must be a short integer variable). If the selected file is in a volume's root directory, the will return a volume reference number; otherwise, it will return a working directory reference number. If the user cancels the dialog, then the function returns an empty (zero-length) string, and it sets  to zero.

If the global variable  is non-zero, FB switches to the more modern Navigation Services dialog. If the one of the FSSpec version of the call is used,  is assumed to be.

You can limit the types of files that appear in the dialog by specifying up to four file types in. For example, is you pass the string " " in, then only files of type " " and type " " will be available for selection. If  is an empty string, or the parameter is omitted, then all file types will be available for selection.

Image was here

If you use the optional  (or   ) parameter, the standard files dialog may display a preview of the file currently selected.

Image was here.

Note: The ...  function does not actually open the selected file. Use the  statement if you need to open the file.

The reference number returned in  is a temporary number, which is only valid until your program quits. You cannot use this same number to refer to this folder at a later date. If you need to keep track of a file's location over time, create and save an alias record for the file.


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Futurebasic/Language/Reference/filesstr fsave

Function
✔ Appearance ✔ Standard ✔ Console

Revised
February, 2002 (Release 6)

Description
This function prompts the user to provide a file name, and to select a folder where the file may be saved. It does this by displaying the standard "Put File" dialog shown below (its appearance may be different on some systems). If the user selects a name, then the name is returned in, and a reference number for the selected directory is returned in   (which must be a short integer variable). If the selected directory is a volume's root directory, then  will return a volume reference number; otherwise, it will return a working directory reference number. If the user cancels the dialog, then the function returns an empty (zero-length) string, and it sets to zero.

The string (if any) that you provide in  will appear as a one-line prompt in the dialog. The string (if any) that you provide in  will appear initially in the file name edit field in the dialog.

If the global variable  is non-zero, FB switches to the more modern Navigation Services dialog.. If the one of the FSSpec version of the call is used,  is assumed to be.

Example: The statement:

will produce a dialog that looks something like this:

Image was here.

Note: The ...  function does not actually open or save a file. Use the statement if you need to open a file, and use output statements like   or   to save information into it.

The reference number returned in  is a temporary number, which is only valid until your program quits. You cannot use this same number to refer to this folder at a later date. If you need to keep track of a file's location over time, create and save an alias record for the file.


text:
Futurebasic/Language/Reference/filesstring function

Function
✔ Appearance ✔ Standard ✔ Console

Description
Returns the file type of the last file returned by the ...  function, as a 4-character string. If the user clicked "cancel" in response to the last File Open dialog, or if the ...  function has never yet been executed, then the  function returns an empty (zero-length) string.

Note: In some cases it's useful to express the file type as a 4-byte long integer rather than as a string. Use the  function and the   function to convert between these two forms.


text:
Futurebasic/Language/Reference/fill

Statement
✔ Appearance ✔ Standard ✔ Console

Description
This statement fills the area around pixel coordinates (in the current output window) with the current color and pen pattern. All the contiguous pixels which have a color equal to the original color at are included in the fill.

Example: This little program paints a red ring:

FB Lite behavior: When you use the "FB Lite" runtime,  switches to the Graphics Window before executing.

title: Futurebasic/Language/Reference/fill


text:
The Science of Programming/SwayPresentations/Objects/Examples5

Here's a switch using typical Sway syntax:

var x = 0; switch (x) {       case(3) { println("greater"); } case(2) { println("equal"); } else   { println("less"); } }

To implement switch, we start by defining the case function in anticipation of it being filtered.

function case(operand,$action,$) {       list(operand,$action,$); }

Remember, a filter takes each statement in turn, so as we saw with filtering pop, one line functions are the best to filter.

The strategy for switch:

 * create a filter with the switch expression in scope
 * have the filter throw a success exception
 * attach the filter to case
 * run the body of the switch, looking for success

function switch(expr,$actions) {       var result; function caseFilter(spec) {           var val; if (expr == spec[0]) {               throw(:success,force(spec[1])); }           else if (spec[2] != :null) {               throw(:success,force(spec[2][0])); }           }        case. filter = caseFilter; result = catch(force($actions)); if (error?(result)) {           if(result . type == :success,result . value,throw(result)); }       else {           :null; }       }

Next Previous Top


text:
General Biology/Classification of Living Things/Eubacteria/Answers

1. Answers may vary. Some possibilities are:

 * 1) Binary fission produces two identical daughter cells.

 * 2) Daughter cells have 2n chromosomes; the daughter cells have the same number of chromosomes as the parent cell.

 * 3) Binary fission commences with a duplicate of the original chromosome.

2. Answers may vary. Some possibilities:

 * 1) Binary fission produces only two identical daughter cells.

 * 2) Daughter bacterial cells have 2n chromosomes, unlike n chromosomes for gametes.

 * 3) Binary fission transpires only in bacteria, and not in gametes.

 * 4) Binary fission does not involve any spindle fibres or asters.

3.

 * a) photoautotrophic

 * b) chemoheterophic

 * c) chemoheterophic

 * d) photoautotrophic

 * e) chemoautotrophic

4. Cocci; least surface area.

5.

 * a) Plasmids

 * b) Conjugation.

6. Yes, because endospores are quite robust.


text:
User talk:Davidcarterphd

Welcome to Wikibooks, Davidcarterphd!

title: User talk:Davidcarterphd


text:
MediaWiki:Categoriespagetext

The following categories contain pages or media. You can explore the categories using [//en.wikibooks.org/wiki/Special:CategoryTree?target=Wikibooks&mode=categories&dotree=Visualization CategoryTree].

[ Start] ·  [ 0-9]  ·  [ A] [ B] [ C] [ D] [ E] [ F] [ G] [ H] [ I] [ J] [ K] [ L] [ M] [ N] [ O] [ P] [ Q] [ R] [ S] [ T] [ U] [ V] [ W] [ X] [ Y] [ Z]

title: MediaWiki:Categoriespagetext


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Futurebasic/Language/Reference/nand

Syntax
result& = exprA {NAND | ^&} exprB

Description
Expression  and expression   are each interpreted as 32-bit integer quantities. The  operator sets each bit in   when the bit in   is set and the corresponding position in  is cleared. This can be thought of as a  expression. The result is another 32-bit quantity; each bit in the result is determined as follows:

INSERT IMAGE HERE!!!!!!!

title: Futurebasic/Language/Reference/nand


text:
Futurebasic/Language/Reference/nor

Syntax
result& = exprA {NOR | ^|} exprB

Description
Expression  and expression   are each interpreted as 32-bit integer quantities. The  operator sets each bit in   when the corresponding bits in both  and   are cleared or when the bit in   is set and the corresponding bit in   is cleared. This can be thought of as a  expression.The result is another 32-bit quantity; each bit in the result is determined as follows:

INSERT IMAGE HERE!!!!

title: Futurebasic/Language/Reference/nor


text:
Futurebasic/Language/Reference/not

Syntax
value = NOT expr

Description
The  operator interprets   as an integer, and returns another integer in whose internal bit pattern all the bits are flipped to their opposite state (i.e., all 1's are changed to 0; and all 0's are changed to 1). Coincidentally, because of the way that integers are stored in FB, the value returned by  equals:.

One common use for  is to reverse the sense of an expression whose value equals   (-1) or   (0). Note that  returns , and   returns. You must be careful when using  with "true" values other than -1. For example:

testValue = 35 IF testValue THEN BEEP 'This produces a beep statement, " " produces the value -36, which is still interpreted as "true" by the  statement.

Another common use for  is to help you set or reset individual bits in a bit pattern. For example:

ÊÊÊpattern& = pattern& AND NOT BIT(7)

This sets bit 7 in  to zero, and leaves all of  's other bits alone.

title: Futurebasic/Language/Reference/not


text: User talk:75.161.157.47

title: User talk:75.161.157.47


text: User talk:65.29.87.154

title: User talk:65.29.87.154


text:
The World of Peer-to-Peer (P2P)/Networks and Protocols/eDonkey

eDonkey
eDonkey the original client for the eDonkey network (also known as eDonkey2000 network or eD2k), was created and managed by MetaMachines (Sam Yagan and Jed McCaleh) based on the city of new York. It had a stable P2P community and the protocol was older than BitTorrent it was created in 2002 shortly after the closing of Napster and competed with the FastTrack network. In June of 2005, the entertainment industry gained a victory in the Supreme Court (USA) that stated that every file-sharing developer could be sued for copyright infringement if they induced such behavior. In September 2005 the Recording Industry Association of America (RIAA) sent several commercial P2P developer cease and desist letters including to MetaMachines and with no funds to battle the interpretation of the Supreme Court decision, Sam Yagan conceded defeat as he testified to the United States Senate Judiciary Committee.

On September 11, 2006 users could not get the eDonkey2000 client software, in September 12, 2006 MetaMachines settles for $30 Million (US) and the agreement closes any avenue MetaMachines had in dealing with any P2P technology in the future...

The eDonkey networks is centralized (as it depends on serves) to provide decentralized sharing of content (not stored on the servers), there are still many software implementations that support the network the most popular is eMule.

Protocol
"The eMule Protocol Specification" ( http://sourceforge.net/project/showfiles.php?group_id=53489&package_id=145950 ) by Yoram Kulbak and Danny Bickson DANSS (Distributed Algorithms, Networking and Secure Systems) Lab - School of Computer Science and Engineering - The Hebrew University of Jerusalem, Israel - January 20, 2005, PDF document provided by the Emule Project.

Kademlia
Started as the Overnet project by Jed McCaleb, the creator of eDonkey2000 to overcome the need of servers. Overnet implemented the Kademlia algorithm. In late 2006, Overnet and all Overnet-owned resources were taken down as a result of legal actions from the RIAA and others. However, since the core of Overnet is decentralized, Overnet clients are still able to function with limited functionality.

The KadC library (http://kadc.sourceforge.net/ ) provides an OpenSource C library to publishing and retrieving records in Kademlia-based Distributed Hash Tables.

A some what old paper named Kademlia: A Peer-to-peer Information System Based on the XOR Metric by Petar Maymounkov and David Mazières can also be a source of information about the protocol.

The network is now known as Kademlia and is supported by many of the implementations of the old eDonkey/Overnet clients, especially by the eMule project. Kademlia is a research effort to implement a full-featured peer-to-peer system based on the XOR metric routing. Of special interest are the objectives for efficient data storage and query; anonymity; network, content and user security and authentication.

eMule content database
( http://content.emule-project.net/ ) a service provided by the eMule project team for the eDonkey2000 and Kad network users, to make free content available for download and easy to find. The content database has been on line since around new years 2004.

Software Implementations

 * eMule ( http://www.emule-project.net/ ) a filesharing software implementation based on the eDonkey2000 network but offers more features than the standard client, open source C++/MFC and windows only, licensed under GPL ( http://sourceforge.net/projects/emule/ )
 * Xmod ( http://savannah.nongnu.org/projects/x-mod/ ) The Xmod is a Project is based on the eMule Client, OpenSource under the GPL.
 * xMule ( http://www.xmule.ws/ ), the X11 Mule, intended to bring a clone of eMule to virtually all the major Unix platforms, with a particular emphasis on Linux. C++ using wxWidgets for the GUI released as OpenSource under the GPL.
 * MLdonkey ( http://mldonkey.sourceforge.net ) is a multi-platform, multi-network P2P implementation. It supports several large networks such as eDonkey, Overnet, Kademlia, Bittorrent, Gnutella (Bearshare, Limewire, etc.), Gnutella2 (Shareaza), or Fasttrack (Kazaa, Imesh, Grobster). Networks can be enabled or disabled. Searches are performed in parallel on all enabled networks. For some networks, each file can be downloaded from multiple clients concurrently.
 * AMule ( http://www.amule.org/wiki/ ) this project is based on the eMule Client, using also C++ but also wxWidgets and crypto++. Opensource under the GPL, currently supports Linux, FreeBSD, OpenBSD, Windows, MacOS X and X-Box on both 32 and 64 bit computers.
 * eMule Bowlfish ( http://pwp.netcabo.pt/DeepSea/ ), another eMule based project that aims to provide an restricted Network solution.
 * Hydranode ( http://hydranode.com/ ) a modular, plugin-driven peer-to-peer client framework which is designed with true multi-network downloads in mind (Support for eDonkey2000 and Bittorrent networks). OpenSource under the GPL, supports Linux and Windows.
 * Shareaza ( multi-protocol, referenced on the Gnutella section )


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The World of Peer-to-Peer (P2P)/Networks and Protocols/Direct Connect

Direct Connect
Direct connect is a peer-to-peer file sharing protocol/network but it uses a central server, this reliance on a central point can also be seen on the old Napster network, in that each server build an independent network (not an hybrid like for instance with eMule). One should note that some clients are now also implementing DHTs that will result in unifying used networks. The Direct Connect protocol was originally developed by Jonathan Hess for use on the Neo-Modus Direct Connect (NMDC) v1, released September 2001 and partially in NMDC v2, released in July 2003.

Direct Connect defines the servers as HUBs. Clients connect to a central hub and that hub feature a list of clients or users connected to it. Users can then search for files to download, or as chat with other users present (on that server).

Direct Connect also implements Tiger tree hashing (TTH) for for file transfers.

NMDC Protocol
created by Jon Hess at Neo-modus protocol mirror ( http://www.teamfair.info/wiki/index.php )

ADC Protocol
The ADC protocol ( http://dcplusplus.sourceforge.net/ADC.html ) is similar to the Neo-Modus Direct Connect (NMDC) protocol. It consists of a text protocol for a client-server network, created with goal to be simple, yet extensible.

Jon Hess contributed to the creation of this protocol with the original Direct Connect idea through the Neo-Modus Direct Connect client / hub. Other major contributing source was Jan Vidar Krey's DCTNG draft that lead to subsequent work by Dustin Brody, Walter Doekes, Timmo Stange, Fredrik Ullner, Fredrik Stenberg and others.

HUB Software Implementations

 * DConnect Daemon ( http://www.dc.ds.pg.gda.pl/ ), an open source Direct Connect's hub (working as daemon) written in C. Works currently under GNU Linux and FreeBSD, but is planned to be able to work on all Unixes and Windows. As a daemon it works in background and does not require any Xwindow system. Supports a telnet administration console.

Client Software Implementations

 * NeoModus Direct Connect
 * DC++ ( http://dcpp.net/ or http://sourceforge.net/projects/dcplusplus/ ), a project aimed at producing a file sharing client using the ADC protocol. It also supports connecting to the Direct Connect network, open source under GPL, using C++/MFC running on Windows. It is developed primarily by Jacek Sieka, nicknamed arnetheduck.
 * BCDC++
 * RevConnect ( http://www.revconnect.com/ ), supports also Kademlia, Open Source under GPL, using C++/MFC running on Windows.
 * Strong DC++ ( http://strongdc.berlios.de/download.php?lang=eng ), Open Source under GPL, using C++/MFC running on Windows.
 * ApexDC++ ( http://www.peerwebdc.tk/ - http://sourceforge.net/projects/apexdc/ ), based on Strong DC++. It has numerous features such as a plugin to block IP addresses (uses PeerGuardian blocklist), super seeding, customization, themes, and a nice Vista-type general user, Open Source under GPL, using C++/MFC running on Windows.
 * TkDC++ ( http://tkdcpp.com ), Open Source under GPL, using C++/MFC running on Windows.
 * GtkDC (http://gna.org/projects/gtkdc/), a Direct Connect client written in C, based on a GIMP toolkit 2.0 GUI. It is intended to run on UNIX-based platforms, but with a little port it should be executable on Windows platform with Gtk libraries. Licensed under the GNU General Public License V2 or later.
 * FlylinkDC++ ( http://www.flylinkdc.com and http://www.flylinkdc.ru ), based on StrongDC++


text:
The World of Peer-to-Peer (P2P)/Networks and Protocols/Napster

Napster
The Napster network was created at application-level using a client-server protocol over point-to-point TCP. The server was in this case a centralized directory that would hold an index of all files offered (MP3/WMA). The clients would connect to the server, identify themselves to the server (users had an account on the server) and send a list of MP3/WMA files they were sharing to it enabling other clients to search that central repository for any file on the network and then request it from any available source. Napster protocol specifications

Software Implementation

 * OpenNap ( http://opennap.sourceforge.net ), a Napster based peer-to-peer, created as open source (GPL), in C using Win32, and so for Windows. Intended to extend the Napster protocol to allow sharing of any media type, and adding the ability to link servers together. Discontinued.
 * audioGnome ( http://www.audiognome.com ), closed source but as freeware for Windows.
 * JNerve ( http://jnerve.sourceforge.net ), an open source (GPL) Java Napster Server Protocol implementation with a goal of cross-platform compatibility.
 * Napsack ( http://napsack.sourceforge.net ) is a specialized multi-threaded client for broadcasting Napster queries across multiple servers; the list of target servers is retrieved from www.napigator.com, and is user-filterable (based on the number of users, files, or gigs indexed). Opensourced (GPL) using Java.


text:
The World of Peer-to-Peer (P2P)/Networks and Protocols/BitTorrent

BitTorrent
BitTorrent is a protocol ( BitTorrent Protocol Specification v1.0 ) created by Bram Cohen derived from the Gnutella concept, but primarily designed to distribute large computer files over the Internet and permit WEB integration, in fact it aimed to be a substitute for the old centralized HTTP downloads, not a full P2P network. As such it initially avoided the limitations of transmitting search request across the network, something that recently has been implemented with the adoption of a DHT similar to the eDonkey solution, that permits searches across a network. Making BitTorrent a two tiers P2P.

BitTorrent is used to distribute legitimate content but in itself does not make any differentiation about the copyright status of the shared material, as any other decentralized network this permits infringement on a massive scale. Bram Cohen and Ashwin Navin founded on September 22, 2004, BitTorrent, Inc. headquartered in San Francisco, California, as a privately held American company that develops transformative technology and products to continue the advancement of a more efficient and open Internet also promotes development of the BitTorrent protocol through R&D and open specifications.

BitTorrent ( http://www.bittorrent.com ) is also the name of the original implementation of the protocol. It started as a Python ( source code and old versions ) application, now refereed as BitTorrent Mainline, that lead to a full featured commercial enterprise. BitTorrent.com part of BitTorrent Inc. is now a destination to download entertainment content using the BitTorrent protocol. The site provide fast, on-demand access to the most comprehensive licensed catalog of thousands of movies, TV shows, music and games, but it also provides content creators a publishing platform to list their works in high-quality alongside the most recognizable titles from major movie studios, TV networks, and record labels.

BitTorrent Inc. also contributes through more broadly focused standards bodies like the Internet Engineering Task Force (IETF) at the LEDBAT working group ( http://www.ietf.org/html.charters/ledbat-charter.html ). BitTorrent, Inc. owns the clients BitTorrent Mainline and µTorrent, as the BitTorrent DNA (Delivery Network Accelerator) which is a free content delivery service based on the BitTorrent protocol that brings the power of user-contributed bandwidth to traditional content publishers while leaving publishers in full control of their files.

The BitTorrent protocol is peer-to-peer in nature, its innovative approach in the beginning, was due to not be centered about the creation a real distributed network but around the specific shared resources, in this case files, preferably large files, as users connect to each other directly to send and receive portions of a large file from other peers who have also downloaded either the file or parts of the it. These pieces are then reassembled into the full file. Since the users are downloading from each other and not from one central server, the bandwidth load of downloading large files is divided between the many sources that the user is downloading from. This decreases the bandwidth cost for people hosting large files, and increases the download speeds for the people downloading large files, because the protocol makes use of the upstream bandwidth of every downloader to increase the effectiveness of the distribution as a whole, and to gain advantage on the part of the downloader. However, there is a central server (called a tracker) which coordinates the action of all such peers. The tracker only manages connections, it does not have any knowledge of the contents of the files being distributed, and therefore a large number of users can be supported with relatively limited tracker bandwidth.

The key philosophy of BitTorrent is that users should upload (transmit outbound) at the same time they are downloading (receiving inbound.) In this manner, network bandwidth is utilized as efficiently as possible. BitTorrent is designed to work better as the number of people interested in a certain file increases, in contrast to other file transfer protocols.

BitTorrent is redefining the way people share and search for content and is getting very popular for downloading movies, TV shows, full music albums and applications (it gains in performance with other alternatives) since it is very file specific and it gains on the "new" factor of P2P content, more users equals more speed, but it will not be the optimum solution to rare files or to distribute content that is not highly sought over.

To download files that are hosted using BitTorrent users must have a BitTorrent client and to publish a file one must run a tracker.

In November 2004, BitTorrent accounted for an astounding 35 percent of all the traffic on the Internet and in 2006 the BitTorrent protocol has risen to over 60 percent of all Internet traffic according to British Web analysis firm CacheLogic. Due to this some ISPs are doing traffic shaping also known as bandwidth throttling, meaning they are reducing the protocol priority inside their networks and reducing its overall performance this has resulted in two kind of responses, some ISPs are investing in upgrading their networks and provide local cache to the protocol and implementors of the protocol are starting to battle ISPs that refuse to adapt by encrypting and randomizing it, this kick need to adapt and the increasing popularity due to deviation from its creators vision is placing more and more its evolution on the hands of independent developers.

The BitTorrent system is highly dependent on active participation of peers since it only goal is the sharing of files. Rare and "old" content is not easy to find on the system, only highly sought after content benefit from this P2P implementation. Small files also don't fully benefit from it, since the needed time for replication is too short and in some extreme situations can even degrade the experience.

Content indexers
There are many different BitTorrent websites that index content, each providing information about files distributed via the BitTorrent protocol. They typically contain multiple torrent files and an index of those files. In a typical scenario, a user would enter such a site and browse or search for the content they desire, based on the torrent descriptions posted at the site by other users. If a torrent with the sought content is found, the user could download that torrent.

Legal Torrents ( http://www.legaltorrents.com ), a collection of Creative Commons-licensed, legally downloadable, freely distributable creator-approved files, from electronic/indie music to movies and books, which have been made available via BitTorrent. Everyone that grabs the BitTorrent client and downloads helps contribute more bandwidth.

There is also OpenBitTorrent ( http://openbittorrent.com ), OpenBitTorrent.kg ( http://www.openbittorrent.kg ), myTorrentTracker ( http://www.mytorrenttracker.com ) and trackhub ( http://trackhub.appspot.com ), all BitTorrent trackers free for anyone to use to share files. You don't need to register, upload or index a torrent anywhere, all you have to do is to include the tracker URL in the torrent file.

Other:
 * bt.etree.org ( http://bt.etree.org/ ), a site provided by the etree.org community for sharing the live concert recordings of trade friendly artists.
 * The Pirate Bay ( http://thepiratebay.org ).
 * mininova ( http://www.mininova.org/ ).

Such websites each have different features to facilitate the user's search. See Wikipedia's Comparison of BitTorrent sites page. Several of the larger BitTorrent tracker sites were shut down citing concerns about problems with copyright holders, mostly representatives of large business interests. While in short it does prevent large scale copyright infringement, it also creates difficulty to legal uses and there is the issue with false notifications, that is claiming infringement of rights over works they do not own. In the long run this does little to solve the problem and pressures the protocol to evolve in ways to avoid this type of disruption. One way people have adapted to this pressure is to create private trackers that are only available by invitation.

Protocol
As already discussed the BitTorrent is a protocol for distributing files. It identifies content by URL and is designed to integrate seamlessly with the web. Its advantage over plain HTTP is that when multiple downloads of the same file happen concurrently, where each downloaders upload to each other, making it possible for the file source to support very large numbers of downloaders with only a modest increase in its load. ( http://www.bittorrent.com/protocol.html ). BitTorrent share some of the nomenclature of other P2P protocols but also creates new ones (see Wikipedia's page BitTorrent vocabulary for an extended list).

 * Torrent:A torrent can mean either a  metadata file or all files described by it, depending on context. The torrent file, as defined in the BitTorrent specification, contains the URLs of multiple trackers, that coordinates communication between the peers in the swarm, and integrity metadata about all the files it makes down-loadable, including their names and sizes and checksums of all pieces in the torrent. It can also contain additional metadata defined in extensions to the BitTorrent specification, known as BitTorrent Enhancement Proposals. Examples of such proposals include metadata for stating who created the torrent, and when.

 * Index:An index is a list of .torrent files (usually including descriptions and other information) managed by a website and available for searches. An index website can also be sometimes refereed as a tracker, but as a "Torrent" tracked not BitTorrent tracker).

The protocol was partially dependent of centralized in do to the requirement of trackers.

 * Client:The program that enables p2p file sharing via the BitTorrent protocol. It denotes still the semi-centralized nature of the protocol, on the protocol definition sometimes the terms is substituted by Peer (ie: peer_id), for instance Gnutella refers to participants always as Peers or Nodes and to implementer as Vendor.

 * Tracker:A tracker is a server that keeps track of which seeds and peers are in the swarm. Clients report information to the tracker periodically and in exchange receive information about other clients to which they can connect. The tracker is not directly involved in the data transfer and does not have a copy of the file.

 * Scrape:This is when a client sends a request to the tracking server for information about the statistics of the torrent, such as with whom to share the file and how well those other users are sharing.

With the adoption of DHT (Distributed Hash Tables) the BitTorrent protocol starts to become more that a semi-centralized distribution network around a single resource, it becomes more decentralized and removes the static point of control, the tracker, this is done by relying in DHTs and the use of the PEX extension. Enabling the volatile Peer to operate also as a tracker, but even if this addressed the need for static tracker servers, there is still a centralization of the network around the content. Peers don't have any default ability to contact each other outside of that context.

 * Seeder:A seeder is a client that has a complete copy of the torrent and still offers it for upload. The more seeders there are, the better the chances of getting a higher download speed. If the seeder seeds the whole copy of the download they should get faster downloads

Seeding rules, like we will see with the special case of super-seeding, are variables and algorithms implemented locally by the client in a general configuration often open in some form to user control. These rules control and may serve to optimize the selection of what available torrent is seeded, instead of just starting the next one in the list, and sort torrents based on a Seeding Rank.

 * Seeding Rank:Is a priority rating, resulting from the calculations based on the active seeding rules of the client, serving to prioritizes your torrents based on how needy they are. It generates a priority queue, where the available torrents are given use of the available open slots for transfer. Several consideration can contribute to the Seeding Rank:
 * Seed Ratio. The lower the ratio, the more scarce a the torrent is, the higher its Seeding Rank should be, giving priority to rare torrents.
 * Seed Count. Similar to Seed ratio but considers not only complete seeds but the number of any client interested in the torrent, works in reverse, giving preference to larger swarms and torrents in high demand.
 * Timed Rotation. Torrents will be rotated in and out of seeding mode. Each torrent is given a length of time they remain seeding.
 * Default. Each torrents will be seeded based on their order they are added to the seed list.

 * Announce:Similar to "Scrape", but means that the client also announces that it wants to join the swarm and that the server should add it to the list of peers in that swarm.

 * Availability (also known as Distributed copies.): This is a common word used on distributed systems, in this case it refers to the number of full copies of the file available to the client. Each seed adds 1.0 to this number, as they have one complete copy of the file. A connected peer with a fraction of the file available adds that fraction to the availability, if no other peer has this part of the file.
 * Example: a peer with 65.3% of the file downloaded increases the availability by 0.653. However, if two peers both have the same portion of the file downloaded - say 50% - and there is only one seeder, the availability is 1.5.

 * Interested:Describes a downloader who wishes to obtain pieces of a file the client has. For example, the uploading client would flag a downloading client as 'interested' if that client did not possess a piece that it did, and wished to obtain it.

 * Downloader:A downloader is any peer that does not have the entire file and is downloading the file. This term, used in Bram Cohen's Python implementation,  lacks the negative connotation attributed to leech.  Bram chose the term downloader over leech because BitTorrent's tit-for-tat ensures downloaders also upload and thus do not unfairly qualify as leeches.

 * Choked:Describes a client that has been refused file pieces. A client chokes another client in several situations:
 * The second client is a seed, in which case it does not want any pieces (i.e., it is completely uninterested)
 * The client is already uploading at its full capacity (it has reached the value of )
 * The second client has been blacklisted for being abusive or is using a blacklisted BitTorrent client.

 * Snubbed:An uploading client is flagged as snubbed if the downloading client has not received any data from it in over 60 seconds.

Extension protocol for BitTorrent
Created by Arvid Norberg and Ludvig Strigeus, (description http://www.rasterbar.com/products/libtorrent/extension_protocol.html ), it is an extension to the protocol that intends to provide a simple and thin transport for future extensions to the BitTorrent protocol. This protocol makes it easy to add new extensions without interfering with the standard bittorrent protocol or clients that don't support this extension.

The extension messages IDs are defined in the handshake is to avoid having a global registry of message IDs. Instead the names of the extension messages requires unique names, which is much easier to do without a global registry.

There seems also to be a concurrent implementation, or variation, by Vuze ( http://wiki.vuze.com/w/Azureus_messaging_protocol ) that is used both by Vuse and Transmission.

Peer exchange
Peer exchange or PEX is a communications protocol that augments the BitTorrent file sharing protocol. It allows a group of users (or peers) that are collaborating to share a given file to do so more swiftly and efficiently. PEX is implemented using one of two common extension protocols.

In the original design of the BitTorrent file sharing protocol clients, that users (Peers) in a file sharing group (known as a "swarm") relied upon a central computer server called a tracker to find each other and to maintain the swarm. PEX greatly reduces the reliance of peers on a tracker by allowing each peer to directly update others in the swarm as to which peers are currently in the swarm. By reducing dependency on a centralized tracker, PEX increases the speed, efficiency, and robustness of the BitTorrent protocol making it more decentralized.

As already explained, users wishing to obtain a copy of a file typically first download a .torrent file that describes the file(s) to be shared, as well as the URLs of one or more central computers called trackers that maintain a list of peers currently sharing the file(s) described in the .torrent file. In the original BitTorrent design, peers then depended on this central tracker to find each other and maintain the swarm. Later development of distributed hash tables (DHTs) meant that partial lists of peers could be held by other computers in the swarm and the load on the central tracker computer could be reduced. PEX allows peers in a swarm to exchange information about the swarm directly without asking (polling) a tracker computer or a DHT. By doing so, PEX leverages the knowledge of peers that a user is connected to by asking them for the addresses of peers that they are connected to. This is faster and more efficient than relying solely on a tracker and reduces the processing load on the tracker. It also keep swarms together when the tracker is down. In fact removing any control over the distribution once a peer keeps a complete copy of the file share.

Peer exchange cannot be used on its own to introduce a new peer to a swarm. To make initial contact with a swarm, each peer must either connect to a tracker using a ".torrent" file, or else use a router computer called a bootstrap node to find a distributed hash table (DHT) which describes a swarm's list of peers. For most BitTorrent users, DHT and PEX will start to work automatically after the user launches a BitTorrent client and opens a .torrent file. A notable exception is "private torrents" which are not freely available; these will disable DHT.

It was agreed between the Azureus and µTorrent developers that any clients which implement either of the mechanisms above try to obey the following limits when sending PEX messages:
 * There should be no more than 50 added peers and 50 removed peers sent in any given PEX message.
 * A peer exchange message should not be sent more frequently than once a minute.

Some clients may choose to enforce these limits and drop connections from clients that ignore these limits.

Permanent DHT tracking
With the PEX implementation and reliance on the distributed hash table (DHT), the evolution into creating a real P2P overlay network that is completely serverless was the next logical step, much like the eDonkey network has evolved as we have seen. The DHT works mostly the same way and will take information not only from old trackers by also from the PEX implementation, creating something like a distributed Database of shared torrents acting as backup tracker when all other trackers are down or can't deliver enough peers, as well as enabling trackerless torrents. The DHT acts and is added to torrents as a pseudo-tracker if the client has the option enabled and DHT trackers can be enabled and disabled per torrent just like regular trackers. Clients using this permanent DHT tracking are now a fully connected decentralized P2P network, they enter the DHT as a new node, this of course makes it necessary for private trackers (or non-public distributions) to exclude themselves from the participating.

Since the DHT is independent of any single tracker (and point of failure), the issue of how the DHT routing table is bootstrapped, the first time using DHT, has to be addressed. This is done in several ways:
 * Bootstrapping the DHT
 * 1) Manually entering a host name and port number of a DHT node.
 * 2) Connect to a tracker that has a .torrent file with a list of DHT nodes.
 * 3) Downloading any torrent with peers who advertise that they support DHT. Not fully supported by all clients as it requires clients to advertise in the BitTorrent handshake DHT support.

Traditionally, .torrent files are downloaded from torrent sites. But several clients also support the Magnet URI scheme. A magnet link can provide not only the torrent hash needed to seek the needed nodes sharing the file in the DHT but may include a tracker for the file.
 * Magnet links

BitTorrent Enhancement Proposal (BEP)
The BitTorrent Enhancement Proposal Process (BEP) is a process started by John Hoffman. The process is defined in the public domain document ( http://www.bittorrent.org/beps/bep_0001.html ).

List of BitTorrent Enhancement Proposals is available ( http://www.bittorrent.org/beps/bep_0000.html ).

A BEP is a design document providing information to the BitTorrent community, or describing a new feature for the BitTorrent protocols. BEPs should provide a concise technical specification of the feature and a rationale for the feature, and are intended to be the primary mechanisms for proposing new features, for collecting community input on an issue, and for documenting the design decisions that have gone into BitTorrent.

The BEP author is responsible for building consensus within the community and documenting dissenting opinions. Because the BEPs are maintained as re-structured text files in a versioned repository, their revision history is the historical record of the feature proposal.

Super-seeding
Super-seeding specified in BEP 16 ( http://www.bittorrent.org/beps/bep_0016.html ) is a extension to the BitTorrent protocol (implemented without changes to the protocol), intended to be used when there is only one seed, it permits to manage the scarcity of a resource.

In a situation when a seeder detects that it is the only source for a file, it will attempt to minimize the amount of data uploaded, as to guarantee external sharing and optimize access to the scarce resource, until it detects that other complete seeders exist. The feature was conceived by John Hoffman and first implemented in the BitTornado client in 2003.

uTP
uTP or µTP (sometimes also referred as Micro Transport Protocol ) is an open source cross-platform protocol, created to be implemented on top of UDP protocol a TCP-like implementation of LEDBAT (a TCP congestion avoidance algorithm).

µTP was developed within BitTorrent, Inc. with no input from either the networking or BitTorrent communities as to be provide reliable, ordered delivery while maintaining minimum extra delay as too automatically slow down the rate at which packets of data are transmitted between users of peer-to-peer file sharing torrents when it interferes with other applications. For example, the protocol should automatically allow the sharing of an ADSL line between a BitTorrent application and a web browser. It was first introduced in the µTorrent 1.8.x beta branches, and publicized in the alpha builds of µTorrent 1.9. as is now the primary transport protocol for uTorrent peer-to-peer connections.

uTP is documented as a BitTorrent extension, in BEP 29 ( http://bittorrent.org/beps/bep_0029.html ). BitTorrent, Inc. has made a C++ implementation available under the MIT license ( http://github.com/bittorrent/libutp ), but the external interface is strictly C (ANSI C89).

BitTorrent protocol encryption
As of January 2005, BitTorrent traffic made up more than a third of total residential Internet traffic. Some ISPs decided to take different measures control and event to subvert P2P traffic, as covered in Shadow play section of this book.

This created a need for providing a BitTorrent protocol encryption. Obfuscation and encryption makes traffic harder to detect and monitor and therefore harder to throttle. BitTorrent protocol encryption is not designed to provide anonymity or confidentiality, even if some solutions will it increase confidentiality by obfuscating the content.

Bram Cohen, the inventor of BitTorrent, opposed adding encryption to the BitTorrent protocol. Cohen stated he was worried that encryption could create incompatibility between clients, stressing the point that the majority of ISPs don't block the torrent protocol. Cohen wrote "I rather suspect that some developer has gotten rate limited by his ISP, and is more interested in trying to hack around his ISP's limitations than in the performance of the Internet as a whole". After some criticism for this position, Cohen later added the ability to receive but not originate encrypted connections on his Mainline client. Notably, when µTorrent was purchased by BitTorrent, Inc. and then became the next mainline release, the ability to originate encrypted connections was retained, but it became turned off by default.

Encryption will not stop a traffic shaping system configured to universally slow down all encrypted, unidentifiable or unknown protocols using a method as simple as packet loss. Encrypting tracker communications prevents eavesdropping on peer lists and does not require upgrading both ends of peer-to-peer connections, but it requires imposing computational overhead on the tracker.

 * Protocol header encryption (PHE):Created by RnySmile and first implemented in BitComet version 0.60 on 8 September 2005. The specifications was neither published, nor is it compatible with MSE/PE, and there are claims that it was already reverse engineered, reducing its usefulness.

 * Message stream encryption (MSE)/Protocol encryption (PE):Developed by Azureus (now Vuze) in late January 2006, that later suffered several alterations permitting a broader acceptance by the creators of other BitTorrent clients.

 * As per the specifications ( http://wiki.vuze.com/w/Message_Stream_Encryption ), MSE/PE uses key exchange combined with the infohash of the torrent to establish an RC4 encryption key. The key exchange helps to minimize the risk of passive listeners, and the infohash helps avoid man-in-the-middle attacks. RC4 is chosen for its speed. The first kilobyte of the RC4 output is discarded to prevent a particular attack.

 * The specification allows for the users to choose between encrypting the headers only or the full connection. Encrypting the full connection provides more obfuscation but uses more CPU time. To ensure compatibility with other clients that don't support this specification, users may also choose whether unencrypted incoming or outgoing connections are still allowed. Supported clients propagate the fact that they have MSE/PE enabled through PEX and DHT.

 * Analysis of this method has shown that statistical measurements of packet sizes and packet directions of the first 100 packets in a TCP session can be used to identify the obfuscated protocol with over 96% accuracy, this makes this solution only effective against the efforts of ISPs that don't adopt state of the art traffic analysis, mostly smaller ISPs.

Various solutions exist to protect the BitTorrent network against attacks including encrypting both peer-to-tracker and peer-to-peer communication, using Microsoft's Teredo so that TCP connections are tunneled within UDP packets, filtering TCP resets before they reach the TCP layer in the end-host, or switching entirely from a TCP-based transport to a UDP-based transport. Each solution has its trade-offs. Filtering out attack TCP resets typically requires kernel access, and the participation of the remote peer since the attacker has to send the reset packet to the local and remote peers. Teredo is not available on all BitTorrent clients. Rewriting TCP reliability, in-order delivery and congestion control in a new UDP protocol represents a substantial engineering effort and would require upgrading both ends of any peer-to-peer connection.

Software Implementations
Wikipedia provides an some relevant information in articles like comparison of BitTorrent software and usage share of BitTorrent clients. The following list is given as to provide a general idea and comparison regarding the implementation details in relation to other P2P protocols. (This should not to be considered a complete list of BitTorrent clients, no special order was used. All links have been verified, special attention has been given to the programming language and licenses of the software. Last update 11 September 2010)

 * BitTorrent Queue Manager ( http://btqueue.sourceforge.net ), a console-based BitTorrent Client with built-in scheduler for handling multiple sessions. It is designed to manage sessions in queue easily without heavy-weight GUI. External module can search for new torrents in trackers and submit it automatically. OpenSource (Python Software Foundation License) project, using Python.
 * Vuze previously called Azureus ( http://azureus.sourceforge.net or http://www.vuze.com/ ), an open source BitTorrent client in Java, probably the more advanced peer for the network (multiple torrent downloads, queuing/priority systems, start/stop seeding options, embedded tracker, Mainline DHT and a lot more) but a known resource hog, consuming large quantities of memory and CPU power.
 * µTorrent ( http://utorrent.com ), a closed source, freeware BitTorrent client in C++, a very complete peer (includes bandwidth prioritization, scheduling, RSS auto-downloading and Mainline DHT and more) with a very low system footprint.
 * BitTornado ( http://bittornado.com ), an open source BitTorrent client in Python based on the original BitTorrent client.
 * BitComet ( http://www.bitcomet.com ), (originally named SimpleBT client from versions 0.11 to 0.37) is a closed source but freeware, BitTorrent client for the MS Windows OS only, it also supports HTTP/FTP download management.
 * ABC (Yet Another BitTorrent Client) ( http://pingpong-abc.sourceforge.net ), an open source BitTorrent client, based on BitTornado.
 * Transmission ( http://transmission.m0k.org/ ), an open source lightweight BitTorrent client with a simple graphic user interface on top of a cross-platform back-end. Transmission runs on Mac OS X with a Cocoa interface, Linux/NetBSD/FreeBSD/OpenBSD with a GTK+ interface, and BeOS with a native interface. Released under the MIT/X Consortium License.
 * Warez ( http://www.warezclient.com ), a closed source, MS Windows only BitTorrent client from Neoteric Ltd. (previously supporting the Ares Network Warez P2P client).
 * Bits on Wheels ( http://bitsonwheels.com ), a freeware but closed source, implementation, written in Objective-C and Cocoa for the Macintosh.
 * Vidora ( http://www.videora.com/ ), a closed source, freeware implementation that also support Really Simple Syndication (RSS) feeds.
 * sharktorrent ( http://sharktorrent.sourceforge.net/ ), an open source (GNU GPL) written in C++. This a cross-platform BitTorrent client uses QT, libtorrent and boost libraries.
 * ted [Torrent Episode Downloader] ( http://www.ted.nu/ ), an open source (GNU GPL) BitTorrent client coded in Java, it also support torrent RSS feeds.
 * rTorrent| ( http://libtorrent.rakshasa.no ) is a text-based ncurses BitTorrent client written in C++, based on the libTorrent libraries for Unix (not to be confused with libtorrent by Arvid Norberg/Rasterbar), whose author's goal is “a focus on high performance and good code. Both the client as the library are available under the GNU GPL.
 * libtorrent ( http://www.rasterbar.com/products/libtorrent/ ) from Rasterbar Software, an open source C++ library, implementing the BitTorrent protocol and core necessities for an application, using zlib and Boost libraries, specifically Boost.Asio and shares the Boost license. This library is also commonly used embedded in devices. The library also provides support for UPnP configuration. libtorrent is used by the following implementations:
 * Halite ( http://www.binarynotions.com/halite-bittorrent-client ), an open-source, under the Boost Software License, this BitTorrent client uses the libtorrent library. Coded in C++ using the Boost library and WTL (Windows only).
 * FireTorrent ( https://addons.mozilla.org/en-US/firefox/addon/10931 ) by Pete Collins, Radical Software Ltd, Jan Varga, Matthew Gertner, open source in JavaScript using the libtorrent library, Mozilla Public License FireFox extension/add-on to download torrents.
 * Folx ( http://www.mac-downloader.com/ ), closed source, using libtorrent library (Mac only).
 * qBittorrent ( http://www.qbittorrent.org/ ), open source GNU GPL, developed by a Ph.D student (Christophe Dumez), a Bittorrent client using C++ / libtorrent and a Qt4 Graphical User Interface.
 * Deluge ( http://deluge-torrent.org ), an open source, using Python and libtorrent, lightweight, cross-platform BitTorrent client in Python released under the GNU GPL license.
 * Limewire, already covered as a well known Gnutella implementation also support the BitTorrent protocol by using the libtorrent library.
 * BTG ( http://btg.berlios.de ), Bittorrent client implemented in C++ and using the Rasterbar Libtorrent library, released under the GNU GPL. Provides a Ncurses, SDL, Gtkmm and WWW GUI, which communicate with a common backend running the actual BitTorrent operation, available only for OSX, BSD and Linux.
 * Free Download Manager (FDM), ( http://www.freedownloadmanager.org ), C++ open source software distributed under GNU GPL using the libtorrent library (Windows only).
 * torrent2exe.com, a web tool, that reportedly converts .torrents into executables (Windows) for distribution, closed source using the libtorrent library.
 * Flush ( http://sourceforge.net/projects/flush ) GTK-based BitTorrent client for Linux, open source C++/GTK+ using the libtorrent library.
 * Pump ( http://www.vipeers.com ), a closed source video manager that supports the BitTorrent protocol by using the libtorrent library.
 * Lince ( http://lincetorrent.sourceforge.net ), open source C++/GTK+/libtorrent BitTorrent client, release under the GNU GPL (Linux/BSD/UNIX-like OSes).
 * Miro, previously known as Democracy Player and DTV ( http://getmiro.com ) is an designed to automatically download videos from RSS-based “channels”, manage them and play them. Open source in Python/GTK/libtorrent, released under the terms of the GNU General Public License.
 * tvitty ( http://tvitty.com ) closed source BitTorrent download add-in for vista media center using libtorrent (Windows only).
 * FatRat ( http://fatrat.dolezel.info ), is an open source download manager for Linux written in C++ using Qt4 and libtorrent libraries.
 * LeechCraft ( http://leechcraft.org ), open source BitTorrent client (supporting also HTTP/FTP downloads), create using C++, Qt and libtorrent. Released under the GNU General Public License.
 * MooPolice ( http://www.moopolice.de ), BitTorrent client for Windows, having an unorthodox GUI. Open source (without a specific license) C++ using MFC and libtorrent BitTorrent client library and MiniUPnP.
 * Linkage ( http://code.google.com/p/linkage ), a lightweight BitTorrent client written in C++ using gtkmm and libtorrent, open source under the GNU General Public License (no longer maintained).
 * Arctic Torrent ( http://int64.org/projects/arctic-torrent ), a small BitTorrent client for Windows (includes a 64bits version). Open Source C++ under the MIT License, using libtorrent.

Specific BitTorrent Papers

 * May 22, 2003 - Incentives Build Robustness in BitTorrent (PDF), Bram Cohen The BitTorrent ﬁle distribution system uses tit-for-tat as a method of seeking pareto eﬃciency. It achieves a higher level of robustness and resource utilization than any currently known cooperative technique. We explain what BitTorrent does, and how economic methods are used to achieve that goal.


text:
Bicycles/Maintenance and Repair/Frames

The frame is the solid part of the bicycle that interconnects the various components. Frames come in various materials, including steel, aluminum, titanium, and carbon fiber. The most popular types of frame are the double diamond and step through frames.

Frames can become cracked or bent and require repair or replacement.

Steel frames can be readily straightened, other materials can't generally be straightened. Tools exist for the straightening of frames, or many can be improvised.

Steel frames can be welded, other materials can't generally be welded.

The paint on a frame can become chipped, etc. and need to be repaired.

Sometimes components can become seized in the frame and require removal.

title: Bicycles/Maintenance and Repair/Frames


text: User talk:77.178.249.42

title: User talk:77.178.249.42


text:
Talk:Music Theory/The Physics of Music

Could you please explain the variable n in the formula mentioned?

title: Talk:Music Theory/The Physics of Music


text:
Bicycles/Maintenance and Repair/Cranks

= Cranks =

The term crank set refers to the cranks, or pedal arms, that connect the pedals to the bottom bracket. The term crankset refers somewhat ambiguously to both cranks and possibly the bottom bracket.

Types of Cranks
Cranks come in various forms.

One piece
In one piece cranksets, there is a single piece of metal bent into a Z shape that forms both cranks and the bottom bracket spindle. These types of cranks are usually found on lower end bikes and BMX bikes. The bottom bracket shell on one piece cranks is much larger than other for other bottom brackets.

Cottered Cranks
Cottered cranks are decidedly the older standard, but replacement parts are still available. Cottered cranks are held with a cotter pin to the bottom bracket spindle. Common repairs on cotter cranks involve the replacement or refacing of the cotter pins which often become worn over time, leading to slop in the cranks. For proper alignment the cotter pins on opposite sides of the bicycle must be pointed in opposite directions, otherwise the cranks will not be 180 degrees apart.

Cotterless
Cotterless cranks come in two main types:

Square Taper
Square taper cranks have a square taper in the mounting hole. The crank is held on primarily with friction, and fixed in place with a crank bolt or nut (depending on the type of bottom bracket). Be careful when ordering crank sets on the internet. The distance of the chain rings from the center of the bottom bracket can vary quite a bit, chain alignment might be completely off and derailleurs might not be able to reach the inner or outer ring. There seems to be no norm that defines this length.

Splined
Splined cranks use a multi-toothed spline to hold the crank. These come in various standards including ISIS and Shimano Octalink (V1 and V2). ISIS is an open standard that has been adopted by various manufacturers in response to the proprietary Shimano standard.

Hollowtech II
Two piece cranks where the drive side has a shaft bolted on which is then pushed through the frame (and bottom bracket)then non drive side attached. Bottom brackets for Hollowtech II are external and require a special tool to remove. Removal of cranks and bottom bracket with Hollowtech II takes around 2 minutes, because of this it does not require much bicycle knowledge.

--MtbEllis (talk) 12:56, 1 November 2009 (UTC)

Crank Removal

 * Cotter pin removal
 * Crank bolt/nut removal
 * Crank puller
 * Hollowtech II removal tool.
 * (details need to be completed)

Removal of Seized Cranks
It is common for cranks to be come seized (by corrosion) to the bottom bracket spindle. The removal of seized cranks is time intensive and can damage the cranks, the bottom bracket bearings and the frame, so caution is advised. Household ammonia can be used to dissolve corrosion between aluminum and steel. (details need to be completed) If bottom bracket is damaged it will need to be "Faced and Chased" at your local bike shop.

--MtbEllis (talk) 13:00, 1 November 2009 (UTC)

Crank Installation
While somewhat debatable, grease is generally recommended when installing cranks. The removal of seized cranks is time intensive and can damage the cranks, the bottom bracket bearings and the frame. (details need to be completed)

title: Bicycles/Maintenance and Repair/Cranks


text:
Music Theory/Baroque

Definition
Baroque music loosely refers to music from around 1600-1750. Baroque music has distinct features to it such as the use of counterpoint and polyphony.

Notable Features
Baroque music can often be characterised by a number of common features:

Sonority and Instrumentation

 * String instruments usually dominate the sonority. These were the primary instruments available at the time.
 * Later in the Baroque period, more woodwind instruments were used, such as the flute, oboe, and bassoon, but strings remained the dominant section.
 * Vocal parts. Vocal music was also very popular in the Baroque Era, especially that written for solo voice and SATB choirs.

Melody

 * Repetition. Phrases are often repeated. Indeed, the structure of many Baroque pieces enabled for repeats of sections
 * Extensive use of ornamentation. The Baroque period truly began the widespread use of ornamentation of melodies for dramatic effect.

Harmony

 * Diatonic harmony. Harmony is plain and simple, but can still be very effective and passionate. Chord choices are limited.
 * High rate of harmonic change. Keys change frequently, and chords are changed rapidly as Baroque pieces progress.

Tonality

 * Unlike in previous Eras, there was a move away from modal music. Major and minor tonalities are used completely.
 * The use of cadences became almost clichéd in the Baroque Era, particularly new cadences such as the Phrygian cadence.

Texture

 * 4-part textures for large scale works were a composer's "rite of passage". Every major composer wrote some works for 4 part choir or strings.
 * Polyphony was very developed. Fugal writing peaked during the Baroque Era.

Structure

 * Recitative continued to be popular. This would be a vocal part accompanied by interspersed continuo chords.
 * Aria. These would have various structures. Some would be in strophic form (verses), although new forms such as ternary (ABA) became popular.

Tempo, Rhythm, and Metre

 * All of tempo, rhythm, and metre were very varied. Often, composers took a particular style.

Composers
Notable composers include:-

 * Gregorio Allegri    (1582-1652)  Italy
 * Johann Pachelbel    (1653-1706)  Germany            Most famous work is the Canon in D
 * Arcangelo Corelli   (1653-1713)  Italy
 * Henry Purcell       (1659-1695)  English
 * Tomaso Albinoni     (1671-1751)  Italy
 * Antonio Vivaldi     (1678-1741)  Italy
 * G.P. Telemann       (1681-1767)  Germany
 * Jean-Philippe Rameau (1683-1764) France
 * Domenico Scarlatti  (1685-1757)  Italy
 * J.S.Bach            (1685-1750)  Germany            Very prolific composer
 * G.F. Handel         (1685-1759)  Germany            Most famous work is the Hallelujah chorus from the Messiah

title: Music Theory/Baroque


text:
User talk:71.212.117.82

Join Us!
--Webaware talk 04:21, 14 April 2008 (UTC)

title: User talk:71.212.117.82


text:
English Grammar/Basic Parts of Speech/Prepositions

A preposition connects the relationship between a noun, pronoun and phrase to other parts of the sentence. Whatever object or phrase the preposition is introducing is called the object of the preposition.

Each bold word in the following sentences are examples of prepositions:

The box is on the desk. The box is under the desk. The box is leaning against the desk. The box is beside the desk. He held the box over the desk. He looked at the box during lunch.

In each sentence a preposition is used to locate the box in time or space. People use prepositions every day without even realizing it. Think of a preposition as a way to relate the object to the rest of the sentence.

Object of the Preposition
The object of the preposition is always a noun, a pronoun or a noun equivalent.

Examples

 * 1) With poise, Gwyneth Paltrow walked to the stage and accepted her Academy Award. (The noun poise is the object of the preposition with.)
 * 2) The Palace welcomed the Prince of Monaco and scheduled a sightseeing tour for him. (The pronoun him is the object of the preposition for.)
 * 3) The director asked about proposing the summer programs for the University. (Proposing the summer programs for the University is a group of words functioning as noun or is a noun equivalent. It is the object of the preposition about.)

Prepositions Indicating Time

 * 1) Use on before days of the week, before months followed by the day or before the time indicating the day, month and year.
 * 2) Use in to indicate year, before months not followed by the day or before the month and year without the day.
 * 3) Use for to refer to a period of time stating the number of hours, days or weeks.
 * 4) Use during to refer to a period of time.
 * 5) Use since to refer to a period of time from the past to the present.

Prepositions Indicating Place or Position

 * 1) Use between when you speak of two persons, places or things.
 * 2) Use among when you speak of three or more persons, places or things.
 * 3) Use on in an address with only the name of the street.
 * 4) Use at when referring to places which indicate the general location.
 * 5) Use in when the given location is more specific.
 * 6) Use in when something is already inside.
 * 7) Use into when there is movement involved in the placement of something.


text: User talk:76.78.43.105

title: User talk:76.78.43.105


text: User talk:130.207.176.163

title: User talk:130.207.176.163


text:
User:Gnetter

I like userboxes.

title: User:Gnetter


text:
User talk:Gnetter

Welcome message
Welcome, Gnetter!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 08:28, 14 April 2008 (UTC)

title: User talk:Gnetter


text: User talk:125.63.90.7

title: User talk:125.63.90.7


text:
Talk:General Chemistry/Introduction to Kinetics

I have been contemplating the usefulness of using a quality wiki in resource in place of a general chemistry textbook. I found this wikibook and began this chapter to try and get a feel for the ins and outs of wiki authoring. I would be interested in continuIng to develop this chapter as a continuation of the that experiment and to work with the author(s) of this wikibook towards the goal of making this a truly usable resource.


text:
User talk:Jak

Welcome message
Welcome, Jak!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 13:53, 14 April 2008 (UTC)

title: User talk:Jak


text:
User talk:DrKay

Welcome to Wikibooks, DrKay! – Mike.lifeguard  | talk 14:42, 14 April 2008 (UTC)

title: User talk:DrKay


text: User talk:64.8.169.253

title: User talk:64.8.169.253


text:
User talk:Numediaweb

Welcome message
Welcome, Numediaweb!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 15:03, 14 April 2008 (UTC)

title: User talk:Numediaweb


text:
User talk:128.82.193.204

Join Us!
-- – Mike.lifeguard  | talk 15:39, 14 April 2008 (UTC)

title: User talk:128.82.193.204


text:
Chess Opening Theory/1. a4/1...a5

=Ware Opening - Symmetric Variation=

1...a5

 * This move is an unusual response to 1. a4, but it is not without merit. If an informed player is playing White, he will not try to develop the rook from a1 to a3 (as ...e5 will prevent it), but will instead wait for a chance to play a5 followed by Ra4. An early 1...a5 by Black prevents this tactic and helps to negate any value of playing 1. a4.

title: Chess Opening Theory/1. a4/1...a5