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Talk:Unary numeral system

Multiplication and Division
The article asserts that "Multiplication and division are more cumbersome"
 * Addition and subtraction are particularly simple in the unary system, as they involve little more than string concatenation. Multiplication and division are more cumbersome, however.

They seem pretty trivial to me. There is no citation for this assertion. If Addition is "little more than string concatenation", then surely multiplication is simply "repeated concatenation". Division is a little odd, but I would not call it cumbersome. —Preceding unsigned comment added by Kwerle (talk • contribs) 17:20, 4 February 2010 (UTC)

Unary 8 image
er... the bottom graphic for '8' seems to actually be 9... the tally on the left has 5 vertical bars and 1 horizontal, instead of 4 vertical and 1 horizontal. Someone might want to fix that.

 * Image:Unary_numeral_eight.png fixed --Henrygb 03:24, 18 Mar 2005 (UTC)

 * Whoa. I got to this article just as you made that change. It was five when I got the article, and four when I got to the image page. - Vague | Rant 12:51, Mar 18, 2005 (UTC)
 * Well, judging by the timestamps, I'd say I actually arrived as the cache was being cleared. Same difference. - Vague | Rant 12:52, Mar 18, 2005 (UTC)

0 in unary
I am top-posting. Sorry if anyone is offended. The notion of zero is a relatively recent one - see http://en.wikipedia.org/wiki/Zero#History. There is no zero in unary. Kwerle (talk) 03:20, 22 November 2010 (UTC)

Am I correct in assuming the unary numeral system is incapable of showing 0? Negative numbers work by putting a minus-sign in front of the digits, just like with any other system, but 0 doesn't seem possible. Of course you'd sort of expect unary's first digit to be the 0, just like every other system's, but that obviously wouldn't work either. :) So, can anyone with the proper knowhow add something sensible about 0 (and negative numbers) to the article? Thanks! Retodon8 18:19, 13 October 2005 (UTC)

 * This whole page is inaccurate since following the pattern set by other bases (the first digit in the set of available digits being 0) would lead to any unary system equating to zero (0, 00, 000, 0000, ... all equal zero). ThomasWinwood 12:11, 26 October 2005 (UTC)

 * Well, since n in all other n-ary bases is represented as 10, it could possibly be 0, 10, 100, 1000. But... that's be retarded. I think a problem here is that, in all other n-ary bases, adding a zero to the end of a number multiplies it by n. In my above attempt at consistency with other bases, adding a 0 would add 1, it wouldn't multiply by 1 (since that gets you nowhere). There doesn't seem to be any way to make it rationally system with the other systems. It seems that, due to the explicitly multiplicative nature of a position number system, there's no way to make a consistent base 1 system; 2 is the smallest integer that can be used multiplicatively.98.95.203.214 (talk) 03:54, 29 September 2011 (UTC)

 * Yes, that's (part of) what I said, but how does that make this page inaccurate? I'd call it incomplete, because I'd like to see the 0 thing talked about. It does make unary an exceptional base system. Basically it is another symptom for the problem my question was about... how to show the value 0 in unary. I guess it's really as simple as I assumed... it's just not possible. Retodon8 17:35, 26 October 2005 (UTC)

 * Unary is basically the system of using strike marks. If you try to write zero in strike marks -- well, you're basically done before you start.  "|" is one.  "||" is two.  || - || = nothing, or null, or the null symbol.  But it is not "0" in that you can't do the usual things you can do with a zero.  You can not write "||0" and mean twenty; if you do, it really is not unary.

I Don't see why there wouldn't be a zero in unary. 68.118.248.157

 * Well, I don't know another way to explain. Maybe... try figuring out how you would write zero if you only have the "1" character" (or "|" or whatever), and you'll reach the same conclusion. You can't. You can just not write anything at all, but not having a character for zero disallows a lot of useful stuff in calculations. Retodon8 23:07, 4 January 2006 (UTC)

 * For example? Kwerle (talk) 03:20, 22 November 2010 (UTC)

The thing is, 'the unary numeral system' is a misnomer. It's something that doesn't exist. For any numeral system, you need an origin (zero) and a unit (one). Your 'digits' go from the origin to the number of the base minus one. A number is the summation of each digit times the base to the power of the position of the digit, where the last digit has position zero. So '||||' in unary is 0 * 1^3 + 0 * 1^2 + 0 * 1^1 + 0 * 1^0. Therefore, the smallest possible base is 2. Talking about zero or negative numbers doesn't make sense, because the 'unary' system doesn't make mathematical sense to begin with. SeverityOne 21:06, 6 February 2006 (UTC)

 * You are off by one - though I don't know that your definition is required for unary. So '||||' in unary is 1 * 1^4 + 1 * 1^3 + 1*1^2 + 1*1^1 + 1*1^0 = 5 (base 10).  So by your definition, unary works just fine.  -1 in unary is just "-|".  Nothing in unary is null or nothing.  "" Kwerle (talk) 03:20, 22 November 2010 (UTC)

Further to your point, if "unary" is defined as a base system with only one mark, what is the correct name for a positional base-1 system following the normal rules of positional notation?
 * Decimal: value of digit n in position x = n×10^x
 * Binary: value of digit n in position x = n×2^x
 * Base 1: value of digit n in position x = n×1^x
 * Phinary: value of digit n in position x = n×φ^x

If Phinary can allow 0 and 1 as standard digits, why can't base 1 have them? --Slashme (talk) 01:31, 18 July 2011 (UTC)

Perhaps the difficulty in representing zero in a system like this can be a possible explanation of the late arrival of the concept of zero. Non-positional systems don't need a zero. it wasn't invented until the numbers being counted grew so large that a non-positional system was unfeasible. Any body know of a similar conjecture in a reliable source? Cliff (talk) 04:25, 29 September 2011 (UTC)

Here is a Unary Radix Positional System that makes sense of both Zero and Fractions, but i saw no place to insert it in an article as yet.

First: Invent a Unary Point.

One might use u for such, but when it is assumed that we are using radix unary, good old. will do just fine.

Every digit position x left of a Unary Point has a value of

For x = 0,1,2,3... 1^x = 1

So this Is a positional radix system.

There is an infinite number of ways to represent each Integer:

111. = 1011. = 110. = 111000. = 00010110. etc.

Though we might make it an Unary Convention to Eliminate all Zeros to show a Unary number in its most compact form, unless otherwise required.

Fractions are Entirely A Comvention; An Abbreviated Unary Fraction.

Omitting a Unary point as redundant for Integers, we have:

1111 ÷ 1111 = 4/4 0111 ÷ 1111 = 3/4 0011 ÷ 1111 = 2/4 0001 ÷ 1111 = 1/4 0000 ÷ 1111 = 0/4

All are Proper Unary Fractions, although 4/4 would by convention be handled by placing another 1 nearest left of Unary Point, and 0 can be simply shown as 0 if desired.

Also:

.1111 ÷ 1111 = 4/4 = 1 .0111 ÷ 1111 = 3/4 .0011 ÷ 1111 = 2/4 = 1/2 .0001 ÷ 1111 = 1/4 .0000 ÷ 1111 = 0/4 = 0

If by Convention we always choose this above form for Every Unary fraction:

.00111 ÷ 11111 = 3/5 .00000001 ÷ 11111111 = 1/8 Etc.

We observe that each denominator has as many 1s in it as its rightmost position value [1^-x], Simply x.

So we can by Convention omit all denominators.

111.001 = 3+1/3 = 3.3333...

Now There is a curious result:

A Terminating Unary Fraction that represents a Repeating Decimal Fraction.

So Why Not ?

I don't see this as damaging Foundations of Mathematics.

Do you ?

🐱🐱🐱 FritzYCat (talk) 23:17, 22 February 2020 (UTC)

A decent integer representation of Pi is 3+16/113 = 3.14159292035... just 2.6676... units high in y 7th decimal place.

Approximately Pi in Unary: 111.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111111111111

There, it's been did.

🐱🐱🐱 FritzYCat (talk) 00:13, 23 February 2020 (UTC)

Base26: (let Z = Zero = 0)

1 = A = .YYYYYYY...

Hex:

1 = .FFFFFFF...

Decimal:

1 = .9999999...

Octal:

1 = .7777777...

Bin:

1 = .1111111...

Unary:

1 = .1111111...

Looking better and better.

🐱🐱🐱 FritzYCat (talk) 00:51, 23 February 2020 (UTC)

I think a suitable neural net could learn to do nearly instant addition in this Unary system.

🐱🐱🐱 FritzYCat (talk) 01:55, 23 February 2020 (UTC)

How to indicate Zero; 0 in Conventional Unary ?

Simple !

Let me count ye ways:

.....Etc. 3 = 111. 2 = 11. 1 = 1.

0 = 0. = .0 = . =  =   =

1/1 =.1 = 1. = 1/1 = .1/1 1/2 = .01 = 1/11 = .1/11 2/2 = .11 = 11/11 = .1 = 1. 1/3 = .001 = 1/111 2/3 = .011 = .11/111 3/3 = .111 = .111/111 = .1 Etc......

Empty [Space] is Zero: 2 = 11 = 1 1 = 101 = 1 1 = 1001 ETC.

If you're Zero Key 0 is broken on your typewriter, Then. Alone implys Zero: No 1s, No Fractions, Unoccupied Space, Therefore 0 it Shall be.

A NonTautological Zero If you wish:

0 is Tautological because First one defines a Space, Then one puts a Null Symbol in that Space in order to Explicitly Indicate that There Is Nothing In This Space, Therefore Coincidentally Filling This Space.

One may Logically, then, Knowing that there is Nothing In This Space, Even though a 0 fills this Space, Ignore This Tautology.

0 x  = 0 x 0 = Space = 0

0 is Infinitely Tautological: An Infinitely Identical Identity

0 = 0 + 0 + 0 + 0 + 0 +...

0 = 0 x 0 x 0 x 0 x 0 x...

0 = 0^0 = 0^1 = 0^2 = 0^...

0 = 0/0 = / =/= 0/0 = 0/1 = 0/2 = 0/...

In Unary: O^0 is No Space is No 0 0^1 is 1 Space is 0 0^2 = 00 0^3 = 000 Etc.

Handy for anbreviating Long strings of 0 and 1 Because 0^N and 1^N have trivial meaning and little practical use, In Unary; if we so desire, We Shall use ^ Thusly within Unary Point Fractions:

Pi approx = 22/7 = 3 1/7

3 1/7 = 111.0000001 or

3 1/7 = 111.0^6,1 6 + 1 = 7

3 16/113 = 111.0^97,1^16

97 + 16 = 113

1 way of conceiving 0 is as Totally Independent of These Operators: Space. + - x / ^

Quoth Captain Picard:

Make It So.

So It Is.

There, it's been did.

🐱🐱🐱 FritzYCat (talk) 18:34, 29 February 2020 (UTC)

These are the 1-adic numbers!
The numeral system described here as "unary numeral system", but without 0, is rather the 1-adic numeral system. Consider —Adhemar 13:01, 21 February 2007 (UTC)
 * in the p-ary numeral system there are p number symbols, the first one with value 0, the last one with value p-1. As SeverityOne points out, it does not make sence below base 2. In the true unuary numeral system, the only number symbol would be 0. The only representable number would be zero as well, represented by all possible strings: 0, 00, 000, -0, -00, -000, etc.
 * in the p-adic numeral system there are p number symbols, the first one with value 1, the last one with value p. This would mean the only symbol in the 1-adic numeral system has value 1. This (and all the other properties of 1-adic numbers) are in accordance with the system described in this article.
 * I don't think that's quite accurate, p-adic numbers are usually considered to be expressions
 * $$ \sum_{i=k}^\infty a_i p^i $$
 * where $$a_i$$ are taken over the set {0, 1, ... p-1}. Thus there is still only 1 1-adic number, 0. Cheers, — sligocki (talk) 05:59, 26 October 2009 (UTC)
 * Cheers. But nobody is talking about p-adic numbers here. 1-adic numbers are k-adic or bijective numbers. — Preceding unsigned comment added by 77.169.168.165 (talk) 18:23, 2 December 2012 (UTC)

Non-standard positional numeral systems

 * I have addressed certain issues by creating the article Non-standard positional numeral systems, and making related changes to Unary numeral system, Golden ratio base, Quater-imaginary base, Positional notation, Base (mathematics), and Category:Positional numeral systems. I suggest further discussion of these issues takes place at talk:Non-standard positional numeral systems.--Niels Ø 14:30, 26 February 2006 (UTC)

Unary is not a positional system, even a nonstandard one (though the others you listed are). The "digits" in unary do not depend on position: five tally marks represent the number five, and will still unambiguously represent the number five if you write the same five tally marks in a different order. -- Milo

 * I initially held the same point of view, but others did consider unary a pos.num.syst., which basically is what made me create the non-std. article. I will now revert your changes; I think the matter should be discussed here first.--Niels Ø 07:41, 2 November 2006 (UTC)

 * The unary numeral system (base-1, a non-standard positional numeral system) ...

How is unary a positional system? -- Jao 11:43, 27 February 2006 (UTC)

 * Read the article Non-standard positional numeral systems. One can argue either way, hence non-standard. If you can find an elegant way of putting it, perhaps something like unary, arguably a non-standard positional..., please go ahead and edit accordingly.--Niels Ø 16:52, 27 February 2006 (UTC)

 * If it is truly "arguably" a positional system, then this is the place to start arguing for it. I have not seen any such arguments, so at the moment the statement is completely unfounded. Incidentally, Non-standard positional numeral systems argues that unary is a non-standard system (which is quite clear), but not that it is a positional system. -- Jao 14:23, 2 November 2006 (UTC)

 * From Non-standard positional numeral systems:
 * In a standard positional numeral system, the base b is a positive integer, and b different numerals are used to represent all non-negative integers. Each numeral represents one of the values 0, 1, 2, etc., up to b-1, but the value also depends on the position of the digit in a number. The value of a digit string like $$d_3d_2d_1d_0$$ in base b is
 * $$d_3\times b^3+d_2\times b^2+d_1\times b+d_0$$.
 * So what applies to unary, and what not? (Surely, not everything must apply; that's the whole point of considering it a "non-std." system.) The base b=1 is a positive integer; b different numreals are used to represent all non-negative integers (or at least the positive ones; zero only if you allow an null string to represent it); the numeral represents 1 instead b-1=0 as it "should"; the value does not depend on the position, but the equation above applies all the same - because all powers of b are 1. So, many of the standard features do apply, including the equation $$d_3\times b^3+d_2\times b^2+d_1\times b+d_0$$, but of course, your objections are caused by the fact that a feature that does not apply is the one implied by the word "position" in the name "positional numeral system". This is a strong argument, but consider that unary undeniably is the bijective numeration system base 1, and all the other bijective numeration systems are positional numeral systems. This proves nothing, but it means that Unary should remain closely linked to Positional numeral system and other related articles. Suppose pos.num.syst.s were called "weighted digit numeration systems" instead (as the digits are assigned weights depending on their position); then we could all agree to include unary as a special case where the weights happen to be all equal.
 * I suggest we leave unary in the non-std. category, but I also think it's a good idea to mention the doubts one may have about this classification in the article. If unary is not a positional system, it is at least intimately connected to the positional systems, and that must be reflected in our articles. Entirely deleting the section on unary from the article Non-standard positional numeral systems and deleting references to positional systems from Unary is not the way.--Niels Ø 15:00, 2 November 2006 (UTC)

One can consider uniary as a standard number system by noting that it does not require the number value zero. In other standard number systems the sybmol 0 is used for the value zero because it is used as a place holder (e.g. in the decimal number 105). This place holder requirement does not exist in unary so the glyph 0 is free to be used for the value 1. This yields a system using only the glyph 0 and is different from the marking system. 69.118.118.118 05:39, 29 January 2007 (UTC)

Unary in theoretical computer science
The article makes out the use of unary in theoretical computer science to be sneaky. I'm sure the reasons unary is used is nothing of the sort. It is used to make formal models of computation manageable. Try writing a Turing machine that multiplies together two numbers given in binary. It is not easy.

Incidentally, in the theory of computation, a modified unary system is often used. In this modified system, "1" means 0, "11" means 1, and so on, so that 0 is representable. CyborgTosser (Only half the battle) 14:04, 17 February 2006 (UTC)

definitely

Proposed merge of Tally mark into this article
Someone added merge tags to Unary numeral system and Tally mark, but failed (I think) to provide arguments or start a discussion, which I hereby do:

 * Oppose: While the things are closely related, I think it's reasonable to have separate articles. Tally marks are unary numeral systems all right, but they are more than that. They have a cultural history, and take different forms in different cultures.--Niels Ø (noe) (talk) 13:34, 19 November 2007 (UTC)

 * Oppose They are distinct, although related. Bubba73 (talk), 17:42, 11 January 2008 (UTC)

Does the Unary System even exist?
I'm not sure if it is possible to have a unary system, for when you try the unary system it always relies on a nothing to differentiate it between the something hence using 2 numerals. Does that make sense? It does to me anyway. —Preceding unsigned comment added by 65.30.72.135 (talk) 07:28, 4 June 2008 (UTC)
 * Unary is not a positional notation but a bijective notation. The base-1 positional notation doesn't exist.  The base-10 bijective goes like 1, 2, 3, 4, 5, 6, 7, 8, 9, A, 11, 12, ..., 19, 1A, 21, ..., 99, 9A, A1, ... - TAKASUGI Shinji (talk) 08:14, 4 June 2008 (UTC)
 * See Non-standard positional numeral systems.--Noe (talk) 16:00, 4 June 2008 (UTC)

 * I also agree on the fact that Base 1 is not even possible. Since Base 1 does not have a character "0", any number in Base 1 would equal to infinity because the number would continue on both the left and right sides of the number.  For example, the number 410 is equal to the number 00000000000000004.0000000000010 because the zeros go on infinitely on both the left and right sides of the number however, the extra zeros are cut off because they are irrelevant.  However, in Base 1, there is only one kind of number so therefore the number 111111111 in Base 1 is equal to 111111111111111111 and is also equivalent to 1 and is also equal to 1.11111111111(etc.).  If all numbers are equal to infinity then you cannot do math using Base 1.  If you cannot do math or represent numbers in a finite way than you really do not have a base at all.  Also, another way to think about Base 1 is to think of a blackboard.  A blank blackboard, in reality, is Base 1.  There is only one kind of color and therefore there is nothing you can do with a blank blackboard.  However, once you start to use chalk then you have two colors, black and white.(aka binary)--JavaBinaryUser (talk) 04:21, 15 August 2013 (UTC)

Simplest?
Really? From the number of confused asking questions here, it seems that many people find the system they learned in (usually denary) to be the simplest. I suggest removal of this term. Objections?Cliff (talk) 18:26, 14 February 2011 (UTC)
 * Of course it's the simplest; it is one-to-one: Three cows, three cats, three dollars, three points, three whatever, is represented by three (often indentical) glyphs. People may misunderstand or have questions about the explanations and other things in the article; they are not misunderstanding unary numbers. Does the simplicity have to be mentioned in the first sentence of the article? Perhaps not, but it certainly makes sense to me.--Nø (talk) 22:07, 14 February 2011 (UTC)

Base 1 Redirect
I feel Unary system is different from base 1 in many ways, for example not being base 1, therefore the redirect from Base 1 should be removed and an article created describing a numeral system in which only 0 may exist because the maximimum is 1. Does anyone object? Does anyone agree?--Sonez1113 (talk) 18:43, 15 March 2011 (UTC)

 * That does not sound like a notable system. The whole point of having number systems in the first place is to represent all numbers, why would you have one that represented only one number? Although this is not a positional number system, it is a base 1 bijective number system and AFAIK the only system commonly called base 1. Cheers, — sligocki (talk) 01:07, 16 March 2011 (UTC)

The redirect from Base 1 needs to be removed for several reasons. First, mentioned specifically in the Unary page is that Unary is a bijective base-1 numeral system. That is not the same thing as a base otherwise it would be mentioned that Unary was a base and not a bijective numeral system. Since Unary is not a base, then most definitely Base 1 should not be redirected to Unary. Second of all, I would argue that Base 1 does not exist, whereas, Unary does. A Base-1 chart is shown in the same fashion of a binary chart:

1^-3=1

1^-2=1

1^-1=1

1^0=1

1^1=1

1^2=1

1^3=1

1^4=1

Given the Base 1 chart and using one's reasoning skills, it can be seen that in Base 1 one cannot represent 0 in decimal or any other number in decimal that is not an integer. All other bases have an equal counterpart to any random number in another base. Following are some examples in case you are not following this: The number 10 in binary is equal to the number 2 in decimal. The number 10 in decimal is equal to "a" in hexadecimal. The number 20 in Octal is equal to the number 10 in hexadecimal. All bases have a number that is an equal counterpart to any random number of any other base. Yet, Base 1 fails to do so. For the number 10.5 in decimal, there is no Base 1 counterpart. Again, for the binary number 101.10110, there is no Base 1 counterpart. Once again, for the hexadecimal number 41.245, there is no Base 1 counterpart. Recalling upon the event upon which the now dwarf-planet Pluto was no longer accepted as a planet, what was the foundation reason for why Pluto was not longer accepted as a planet? The reason was that Pluto did not meet the requirements to be a planet. What were the requirements modeled after? They were modeled after our own planets. I take it that essentially the reason why it was not considered a planet any longer was because it was substantially different from the other planets. Is not Base 1 the same? In addition to Base 1 not being able to have a number equal to any random number of another base, Base 1 is clearly symmetrical based off the Base 1 Chart diagramed before, and Base 1 is infinite. I will further expound upon the other two reasons now to demonstrate my point. First of all, Base 1 is symmetrical. The Base 1 Chart clearly dictates that the Base 1 number 1111 is equivalent to the Base 1 number .1111, therefore making it symmetrical. Both numbers are equal to 4 in decimal because the addition of 1^1,1^2,1^3, and 1^4 is equal to 4 in decimal as is the addition of 1^-1,1^-2,1^-3, and 1^-4. Calling again upon the reasoning of the dwarf planet Pluto, no other base has numbers that when reflected about the "." are the same equivalent in decimal still. Secondly, Base 1 is infinite. In all other bases there is a number zero that can be left off when redundant, and at least another number that is greater than 0 making them numbers with value rather than just place holders. As mentioned in the "Does the Unary System even exist?" section later down on this page, if there are not any zeros, then the number would be forced to go on forever as each number greater than zero will never be redundant except to the point in saying that each number in Base 1 is infinite. (Seriously, if you have any arguments for me, post them on this page or cause there to be some way for me to see them. I have pondered this whole concept through immensely and I would rather hear counterarguments than have readers brush this off thinking that I don't know anything.) --JavaBinaryUser (talk) 22:25, 28 October 2013 (UTC)

 * Having a redirect from Base 1 does not mean it is equivalent to 'base 1': it simply means that this is the article that best covers that term. Any mention of 'base 1', even one explaining that it is not proper for indicating 'unary' makes it a good candidate for the redirect. I don't think any better target exists, nor that one is needed. Bcharles (talk) 22:32, 15 June 2014 (UTC)

trying to be too clever, you've introduced an inconsistency into these wiki pages
Bijective-unary is not "base 1". This business about "bijectivity" screws up the meaning of the word "radix / base". Bijectivity seems to remove "the symbol for zero" from the set of symbols, yet the definition of "radix / base" is itself based on including the symbol for zero. It's gotta be one way or the other; without rewriting all the definitions, you are going to have a problem if you "change the rules for base 1" and try to pretend it's consistent. Bijective-unary is not "base 1". 108.14.125.186 (talk) 19:15, 11 May 2013 (UTC)

Empty References section
Hey, i'm new to WP here. Is it proper to have an empty references section? Should it be removed or kept? Perhaps does the page deserve a missing refs templates? Scimonster (talk) 16:32, 5 March 2014 (UTC)
 * The article has references now so no need to remove the References section. Blackbombchu (talk) 03:50, 13 November 2014 (UTC)

Positional unary numeral system
By regualar numeral system, I meant Positional numeral system where you have a digit for all numbers from 0 to 1 less than the base as opposed to Bijective numeral where you have a digit for all numbers from 1 to the base. Maybe the sentence you removed should get added back in except for the phrase "regular numeral system" getting replaced by "positional numeral system". Blackbombchu (talk) 03:46, 13 November 2014 (UTC)
 * I don't think so. It seems a confusing and longwinded way of saying "this is not a positional number system". Since it isn't a positional number system, what do we care about how a nonexistent positional number system would behave? —David Eppstein (talk) 04:12, 13 November 2014 (UTC)

example of multiplication
"However, multiplication is more cumbersome", can somebody please add a numeral example? --Backinstadiums (talk) 14:50, 24 February 2019 (UTC)
 * Perhaps "cumbersome" is the wrong word. The procedure itself is very straightforward: for example, to multiply ||||| by |||||||, you take each | of ||||||| and replace it by ||||| (5 × 7 = 35). However, trying to apply this to numbers of any significant size should explain pretty well without words the disadvantages of the unary system. Double sharp (talk) 05:01, 25 February 2019 (UTC)

Tally marks
1. Please explain why you disagree with modification of the lead sentence on tally marks that I made here.

2. The removal of some narrative on the Chinese characters and lack of their relevance to the subject I already briefly explained in another edit summary - so if you separately disagree with that as well, please explain also.

These are two different topics. Please don't combine them in your explanation if you can :) cherkash (talk) 18:01, 22 January 2022 (UTC)
 * Tally marks are clearly a use of the unary number system and their long historical usage should not be removed from this article. As for whether the Chinese idiograms for 1, 2, 3 are an instance of this use, my opinion is only that we should follow what the reliable sources say, as I have no particular expertise in Chinese writing myself. Do you have a good reason to doubt the sources we are using for this claim? Or do you have sources that say the opposite, that the resemblance to tally marks for these characters is only coincidental? —David Eppstein (talk) 18:50, 22 January 2022 (UTC)
 * 1. Tally marks are only strenuously related to the unary system. Neither of them derives from the other: the tally marks are clearly just a pictorial indication of separate objects (no direct relation to the unary system), whereas the unary system comes to be a particular case of a base-n system (hence again, no direct relation to the tally marks). The fact they happen to resemble each other (especially when "1" is used as a digit) is just a coincidence. The world is full of such distant relations. So we should name them what they are: superficially related things.

 * 2. Now, based on 1 above, since any elaboration on Chinese (or any other characters) relates only to the tally marks (but not to the unary system), any mention of them better be left to the tally marks article. It doesn't need to be here. Generally, the article on X may (but doesn't have to) mention Y if it's somehow related to X. But it definitely shouldn't mention Z just because it relates to Y which in turn relates to X, without any direct link between X and Z - otherwise, we are stretching narrative too much in my opinion. cherkash (talk) 09:47, 23 January 2022 (UTC)
 * The unary system is not a base-n system. It derives from different principles, in fact the same principles as tally marks: one mark per unit. So your whole argument is based on a false premise. —David Eppstein (talk) 20:01, 23 January 2022 (UTC)

Quinary?
The section "Comparison with tally mark systems" states that (real-life) tally marks are a mix of unary and quinary because they group tallies in segments of five. I believe quinary is a positional system, and while the bijective positional system base 1 is identical to unary, there is nothing positional about the way the grouping in fives work. Therefore, I'm inclined to say it is not quinary at all. Perhaps, rather than removing the statement completely, we can find a way to state it in a more correct way ("a grouping in fives, but without the positionality of the quinary system", or sth like that).--Nø (talk) 10:16, 29 May 2022 (UTC)

 * While it is tempting to compare tally marks and quinary because they both group in 5’s, that’s where the similarities end. The argument falls apart after counting to 2510 (1005) where we don’t see a third “digit” added to the number. I think that tally mark groupings are for ease of reading, as we have in thousands separators. I’m reverting the edit that added this section; it was original research (admittedly so in the edit notes). —Bando26 (talk) 15:35, 3 July 2022 (UTC)

title: Talk:Unary numeral system


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Rm (Unix)

  (short for remove) is a basic command on Unix and Unix-like operating systems used to remove objects such as computer files, directories and symbolic links from file systems and also special files such as device nodes, pipes and sockets, similar to the  command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell.

Overview
The  command removes references to objects from the filesystem using the unlink system call, where those objects might have had multiple references (for example, a file with two different names), and the objects themselves are discarded only when all references have been removed and no programs still have open handles to the objects.

This allows for scenarios where a program can open a file, immediately remove it from the filesystem, and then use it for temporary space, knowing that the file's space will be reclaimed after the program exits, even if it exits by crashing.

The command generally does not destroy file data, since its purpose is really merely to unlink references, and the filesystem space freed may still contain leftover data from the removed file. This can be a security concern in some cases, and hardened versions sometimes provide for wiping out the data as the last link is being cut, and programs such as shred and srm are available which specifically provide data wiping capability.

is generally only seen on UNIX-derived operating systems, which typically do not provide for recovery of deleted files through a mechanism like the recycle bin, hence the tendency for users to enclose  in some kind of wrapper to limit accidental file deletion.

There are undelete utilities that will attempt to reconstruct the index and can bring the file back if the parts were not reused.

History
On some old versions of Unix, the  command would delete directories if they were empty. This behaviour can still be obtained in some versions of  with the   flag, e.g., the BSDs (such as FreeBSD, NetBSD, OpenBSD and macOS) derived from 4.4BSD-Lite2.

The version of  bundled in GNU coreutils was written by Paul Rubin, David MacKenzie, Richard Stallman, and Jim Meyering. This version also provides  option, to help with compatibility. The same functionality is provided by the standard  command.

The  option in Version 7 replaced , or "delete from switches", which debuted in Version 1. Doug McIlroy wrote that  "was a desperation tool designed to clean up files with unutterable names".

The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. KolibriOS includes an implementation of the rm command. The rm command has also been ported to the IBM i operating system.

Syntax
deletes the file specified after options are added. Users can use a full path or a relative file path to specify the files to delete. doesn't delete a directory by default. deletes the file "foo" in the directory the user is currently in.

, like other commands, uses options to specify how it will behave:

 *  , "recursive," which removes directories, removing the contents recursively beforehand (so as not to leave files without a directory to reside in).
 *  , "interactive" which asks for every deletion to be confirmed.
 *  , "force," which ignores non-existent files and overrides any confirmation prompts (effectively canceling ), although it will not remove files from a directory if the directory is write-protected.
 *  , "verbose," which prints what  is doing onto the terminal
 *  , "directory," which deletes an empty directory, and only works if the specified directory is empty.
 *  , only removes files on the same file system as the argument, and will ignore mounted file systems.

can be overlain by a shell alias (C shell alias, Bourne shell or Bash) function of " " so as to avoid accidental deletion of files. If a user still wishes to delete a large number of files without confirmation, they can manually cancel out the  argument by adding the   option (as the option specified later on the expanded command line " " takes precedence). Unfortunately this approach generates dangerous habits towards the use of wildcarding, leading to its own version of accidental removals.

(variously,,  , and others) is frequently used in jokes and anecdotes about Unix disasters, such as the loss of many files during the production of film Toy Story 2 at Pixar. The  variant of the command, if run by a superuser, would cause every file accessible from the present file system to be deleted from the machine.

is often used in conjunction with xargs to supply a list of files to delete:

Or, to remove all PNG images in all directories below the current one:

Permissions
Usually, on most filesystems, deleting a file requires write permission on the parent directory (and execute permission, in order to enter the directory in the first place). (Note that, confusingly for beginners, permissions on the file itself are irrelevant. However, GNU   asks for confirmation if a write-protected file is to be deleted, unless the -f option is used.)

To delete a directory (with ), one must delete all of its contents recursively. This requires that one must have read and write and execute permission to that directory (if it's not empty) and all non-empty subdirectories recursively (if there are any). The read permissions are needed to list the contents of the directory in order to delete them. This sometimes leads to an odd situation where a non-empty directory cannot be deleted because one doesn't have write permission to it and so cannot delete its contents; but if the same directory were empty, one would be able to delete it.

If a file resides in a directory with the sticky bit set, then deleting the file requires one to be the owner of the file.

Protection of the filesystem root
Sun Microsystems introduced " " protection in Solaris 10, first released in 2005. Upon executing the command, the system now reports that the removal of / is not allowed. Shortly after, the same functionality was introduced into FreeBSD version of  utility. GNU  refuses to execute   if the   option is given, which has been the default since version 6.4 of GNU Core Utilities was released in 2006. In newer systems, this failsafe is always active, even without the option. To run the command, user must bypass the failsafe by adding the option, even if they are the superuser.

User-proofing
Systems administrators, designers, and even users often attempt to defend themselves against accidentally deleting files by creating an alias or function along the lines of:

This results in  asking the user to confirm on a file-by-file basis whether it should be deleted, by pressing the Y or N key. Unfortunately, this tends to train users to be careless about the wildcards they hand into their  commands, as well as encouraging a tendency to alternately pound   and the return key to affirm removes - until just past the one file they needed to keep. Users have even been seen going as far as " ", which automatically inserts "y" for each file.

A compromise that allows users to confirm just once, encourages proper wildcarding, and makes verification of the list easier can be achieved with something like:

It is important to note that this function should not be made into a shell script, which would run a risk of it being found ahead of the system  in the search path, nor should it be allowed in non-interactive shells where it could break batch jobs. Enclosing the definition in the  construct protects against the latter.

There exist third-party alternatives which prevent accidental deletion of important files, such as "safe-rm" or "trash".

Maximum command line argument limitation
GNU Core Utilities implementation used in multiple Linux distributions will be limited in command line arguments bytes number of pages that are allocated within the kernel for command-line arguments before kernel 2.6.23 Released on 9 October 2007 were defined at kernel compile time at variable   in   file but new kernels limits the maximum argument length to 25% of the maximum stack limit (ulimit -s). Error:  will prompt if command-line argument limit is exceed

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

title: Rm (Unix)


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User talk:Burgester

Test Yourself

We all are given disadvantages in life. Some more challenging than others but obstacles exist for all of us. It is the common man or woman, the common soul who chooses to yield to life's challenges and keep the status quo lifestyle. Why am I fat? Why do I procrastinate? Why can I not do this or that? Why do I think about improving myself yet continue to be frustrated by doing nothing? Why do I feel sad? Why Why Why!

One consistent theme exists - doing nothing or making a futile attempt only to yield to the circumstance at hand. True, some have it very hard. But also true is the fact that all individuals are responsible for themselves and their own well being. Their choices are none other than their own. You drive your own path in life!

Life is a test. Can I do this or that? Of course you can. It may take time but everyone is capable of overcoming obstacles. Whether it is anxiety or a simple mental block - these are tests. The way to overcome them is simple - test yourself. How you may ask - well take the worse case scenario and build off of that.

I am not trying to preach some self help advice or be a motivational speaker. I just want to tell you the concept that I believe in. If you test yourself on trying something - and you keep it up for as long as it takes - you will get there. Then what? You are one step closer to becoming a foundation of strength. So simple a concept.

Test yourself on something you find hard to accomplish or even unimaginable and then think of the common soul! The weak ones who do nothing yet you push yourself hard and blow away your enemies! You relish in the fact that you climbed some mountain over the weekend while the common soul sat on their couch sipping soda, eating chips and continuing to get fatter in front of the tv. You did someting! You worked hard to do it and you accomplished something no one can take away from you. You have built an anchor of strength.

Who cares what others think or the negative energy you feel - just freaking do it! Get out there and hit an extreme point and you'll realize the satisfaction that you can achieve!

Want to hear more?

The Burgester!

title: User talk:Burgester


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Byala

Byala may refer to:
 * Byala, Varna Province, a town in Varna Province in northeastern Bulgaria
 * Byala, Ruse Province, a town in Ruse Province in northern Bulgaria
 * Byala, Sliven Province, a village in Sliven Municipality in southeastern Bulgaria
 * Nawarupa - a mythical creature in Burmese and Arakanese mythology

title: Byala


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Swimming at the 1980 Summer Olympics

Swimming as usual was one of the three aquatics disciplines at the 1980 Summer Olympics—the other two being Water Polo and Diving. It was held in the Swimming Pool of the Olimpiysky Sports Complex between July 20 and July 27. There was a total of 333 participants from 41 countries competing.

Because the number of participants was reduced by the boycott, FINA broke format by doing away with the semifinals. Instead, the top 8 finishers from the heats qualified directly for the final, or final A as it was called. In events up to 400m, those that finished 9th to 16th in the heats would swim in Final B for the 9th place after the swimmers from Final A swam. This would continue as the Olympic format up to the 1996 Olympic Games.

Participating nations
333 swimmers from 41 nations competed.

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Men's events
 * Swimmers who participated in the heats only and received medals.

Women's events
 * Swimmers who participated in the heats only and received medals.

Gallery of the medalists
Some of the Olympic medalists in Moscow:

title: Swimming at the 1980 Summer Olympics


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Talk:Puddling furnace

Puddling v. pudding
"puddling seems to be more common on the Google poll, and is the form used in the OED. See User talk:Noisy for details. Shimmin 23:21, Feb 10, 2005 (UTC)

Comment
I have removed the desription of other processes. These do not belong here. Any one wanting to konw about them should follow the link. I am not sure to what extent puddled iron may have been the raw material for cementation process (for blister steel) and then for the production of crucible steel in the late 19th and early 20th centuries. It was almost certainly not before 1850, when the main raw material was imported Swedish (and sometimes Russian) iron. The ability to produce good steel depends on the iron being particularly free of phospherus, which iron from English ores is not. Peterkingiron 22:07, 10 April 2006 (UTC)

There is a separate page for 'puddling', which probably ought to be abolished, being merged with this one. Peterkingiron 22:17, 10 April 2006 (UTC)

I have now greatly expanded the article, adding a historical section and references. In doing so, I have deleted the following text as mistaken or misleading:
 * The puddling furnace was also used as the first step in making crucible steel as well (see cementation process).
 * It is the process of manually handling and stirring the iron during and after this process that gives us the name "wrought". Invented by Peter Onions and patented by Henry Cort in 1783–4, the puddling process, along with the blast furnace, led to a massive increase in the amount of iron being produced every year.

Peterkingiron 16:15, 1 May 2006 (UTC)

Merge Proposal with puddling (metallurgy)
Support. At present there are a lot of articles on different aspects of historical iron production. These need to be sorted out so that there is one main article gving an overview of the whole process with links (using the 'main' template to separate ones for each process and its associated plant. I have probably the expertise for this, but not necessarily the time.  Other articles to which this applies include blast furnace, and steel.  In some cases because the subject this not tightly enough defined, peripheral subjects have been brought in.  Over past months, I have removed a number of errors and incongruities, but the whole subject needs a thorough tidy up.   Peterkingiron 16:48, 30 September 2006 (UTC)
 * Support. Everything in the furnace article is describing the process and the text should be moved there. Obviously the furnace is not a technology by itself, it's a structure. -- Goldie (tell me) 13:55, 1 December 2006 (UTC)
 * As far as I am concerned you are welcome to go ahead and do this. I think there are puddling sections in other iron-related or steel-related articles.  These need to be trimmed down with a cross-references placed at the head of the section - see main article: ther is a template for doing this called 'main'.  Unfortunately I do not have the time to tackle this, as sorting out the iron and steel articles will be a major undertaking.  Peterkingiron 16:26, 3 December 2006 (UTC)

title: Talk:Puddling furnace


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Giant clam

Tridacna gigas, the giant clam, is the most well-known species of the giant clam genus Tridacna. Giant clams are the largest living bivalve mollusks. Several other species of "giant clams" in the genus Tridacna, are often misidentified as Tridacna gigas.

Known to indigenous peoples in the area for thousands of years, Antonio Pigafetta also documented these in his journal as early as 1521. One of a number of large clam species native to the shallow coral reefs of the South Pacific and Indian oceans, they can weigh more than 200 kg, measure as much as 120 cm across and have an average lifespan in the wild of over 100 years. They are also found off the shores of the Philippines and in the South China Sea in the coral reefs of Malaysia.

The giant clam lives in flat coral sand or broken coral and can be found at depths of as much as 20 m (66 ft). Its range covers the Indo-Pacific, but populations are diminishing quickly, and the giant clam has become extinct in many areas where it was once common. The maxima clam has the largest geographical distribution among giant clam species; it can be found off high- or low-elevation islands, in lagoons or fringing reefs. Its rapid growth rate is likely due to its ability to cultivate algae in its body tissue.

Although larval clams are planktonic, they become sessile in adulthood. The creature's mantle tissues act as a habitat for the symbiotic single-celled dinoflagellate algae (zooxanthellae) from which the adult clams get most of their nutrition. By day, the clam opens its shell and extends its mantle tissue so that the algae receive the sunlight they need to photosynthesise.

Anatomy
Young T. gigas are difficult to distinguish from other species of Tridacninae. Adult T. gigas are the only giant clams unable to close their shells completely, allowing part of the brownish-yellow mantle to remain visible. Tridacna gigas has four or five vertical folds in its shell, which serves as the main characteristic differentiating it from the similar T. derasa, with six or seven vertical folds. Similar to coral matrices composed of calcium carbonate, giant clams grow their shells through the process of biomineralization, which is very sensitive to seasonal temperature. The isotopic ratio of oxygen in carbonate and the ratio between Strontium and Calcium together can be used to determine historical sea surface temperature.

The mantle border itself is covered in several hundred to several thousand pinhole eyespots about .5mm in diameter. Each one consists of a small cavity containing a pupil-like aperture and a base of 100 or more photoreceptors sensitive to three different ranges of light, including UV which may be unique among molluscs. These receptors allow T. gigas to partially close their shells in response to dimming of light, change in the direction of light, or the movement of an object. The optical system forms an image by sequential, local dimming of some eyes using pigment from the aperture.

Largest specimens
The largest known T. gigas specimen measured 137 cm, and it weighed 230 kg (510 lb) dead and estimated 250 kg (550 lb) alive. It was discovered around 1817 on the north western coast of Sumatra, Indonesia, and its shells are now on display in a museum in Northern Ireland. A heavier giant clam was found in 1956 off the Japanese island of Ishigaki. The shell's length was 115 cm, and it weighed 333 kg dead and estimated 340 kg alive.

Feeding
Giant clams are filter-feeders, yet 65-70 percent of their nutritional needs are supplied by zooxanthellae. This enables giant clams to grow as large as one meter in length even in nutrient-poor coral-reef waters. The clams cultivate algae in a special circulatory system which enables them to keep a substantially higher number of symbionts per unit of volume. The mantle's edges are packed with symbiotic zooxanthellae that presumably utilize carbon dioxide, phosphates, and nitrates supplied by the clam.

In very small clams—10 mg dry tissue weight—filter feeding provides about 65% of total carbon needed for respiration and growth; larger clams (10 g) acquire only 34% of carbon from this source. A single species of zooxenthellae may be symbionts of both giant clams and nearby reef–building (hermatypic) corals.

Reproduction
Tridacna gigas reproduce sexually and are hermaphrodites (producing both eggs and sperm). Self-fertilization is not possible, but this characteristic does allow them to reproduce with any other member of the species. This reduces the burden of finding a compatible mate, while simultaneously doubling the number of offspring produced by the process. As with all other forms of sexual reproduction, hermaphroditism ensures that new gene combinations be passed to further generations.

Since giant clams cannot move themselves, they adopt broadcast spawning, releasing sperm and eggs into the water. A transmitter substance called spawning induced substance (SIS) helps synchronize the release of sperm and eggs to ensure fertilization. The substance is released through a syphonal outlet. Other clams can detect SIS immediately. Incoming water passes chemoreceptors situated close to the incurrent syphon, which transmit the information directly to the cerebral ganglia, a simple form of brain.

Detection of SIS stimulates the giant clam to swell its mantle in the central region and to contract its adductor muscle. Each clam then fills its water chambers and closes the incurrent syphon. The shell contracts vigorously with the adductor's help, so the excurrent chamber's contents flows through the excurrent syphon. After a few contractions containing only water, eggs and sperm appear in the excurrent chamber and then pass through the excurrent syphon into the water. Female eggs have a diameter of 100 micrometre. Egg release initiates the reproductive process. An adult T. gigas can release more than 500 million eggs at a time.

Spawning seems to coincide with incoming tides near the second (full), third, and fourth (new) quarters of the moon phase. Spawning contractions occur every two or three minutes, with intense spawning ranging from thirty minutes to two and a half hours. Clams that do not respond to the spawning of neighboring clams may be reproductively inactive.

Development

The fertilized egg floats in the sea for about 12 hours until eventually a larva (trochophore) hatches. It then starts to produce a calcium carbonate shell. Two days after fertilization it measures 160 micrometre. Soon it develops a "foot," which is used to move on the ground; it can also swim to search for appropriate habitat.

At roughly one week of age, the clam settles on the ground, although it changes location frequently within the first few weeks. The larva does not yet have symbiotic algae, so it depends completely on plankton. Free floating zooxanthellae are also captured while filtering food. Eventually the front adductor muscle disappears and the rear muscle moves into the clam's center. Many small clams die at this stage. The clam is considered a juvenile when it reaches a length of 20 cm. It is difficult to observe the growth rate of T. gigas in the wild, but laboratory-reared giant clams have been observed to grow 12 cm a year.

The ability for Tridacna to grow to such large sizes with fleshy mantles that extend beyond the edges of their shells is considered to be the result of total reorganization of bivalve development and morphology. Two evolutionary explanations were historically suggested for this process. Sir Yonge suggested and maintained for many years that the visceral-pedal ganglia complex rotate 180 degrees relative to the shell, requiring that they develop and evolve independently. Stasek proposed instead that the growth occurs primarily in a posterior direction instead of the more typical direction of ventral in most bivalves, which is reflected in the transitional stages of alternative ways of growing that juveniles undergo.

Human relevance
The main reason that giant clams are becoming endangered is likely to be intensive exploitation by bivalve fishing vessels. Mainly large adults are killed, since they are the most profitable. The giant clam is considered a delicacy in Japan (known as himejako), France, Southeast Asia and many Pacific Islands. Some Asian foods include the meat from the muscles of clams. On the black market, giant clam shells are sold as decorative accoutrements. Large amounts of money are paid for the adductor muscle, which Chinese people believe to have aphrodisiac powers.

Legend
As is often the case with uncharacteristically large species, the giant clam has been historically misunderstood.

Even in countries where giant clams are easily seen, stories depict giant clams as aggressive beings. For instance, a Polynesian folk tale involves a monkey's hand being bitten off, and a Maori legend involves an attack on a canoe. Starting from the 18th century, claims of danger had surfaced to the western world. In 1920s, a reputable science magazine Popular Mechanics once claimed that the great mollusc had caused deaths; versions of the U.S. Navy Diving Manual even gave detailed instructions for releasing oneself from its grasp by severing the adductor muscles used to close its shell. In an account of the discovery of the Pearl of Lao Tzu, Wilburn Cobb said he was told that a Dyak diver was drowned when the Tridacna closed its shell on his arm. In practice, their abductor muscle's slow speed and the need to force water out of their shell prevents them from trapping a human.

Other myths focus on giant clams huge size being associated with long age. While, giant clams do live a long time and can serve as a bio-metric for historic climatic conditions, their large size is more likely associated with fast growth.

Aquaculture
Mass culture of giant clams began at the Micronesian Mariculture Demonstration Center in Palau (Belau). A large Australian government-funded project from 1985 to 1992 mass-cultured giant clams, particularly T. gigas at James Cook University's Orpheus Island Research Station, and supported the development of hatcheries in the Pacific Islands and the Philippines. Seven of the ten known species of giant clams in the world are found in the coral reefs of the South China Sea.

Conservation status
There is concern among conservationists about whether those who use the species as a source of livelihood are overexploiting it. The numbers in the wild have been greatly reduced by extensive harvesting for food and the aquarium trade. The species is listed in Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning international trade (including in parts and derivatives) is regulated.

T. gigas has been reported as locally extinct in peninsular Malaysia, while T. derasa and Hippopus porcellanus are restricted to Eastern Malaysia. These recent local extinctions have resulted in the introduction of giant clams to Hawaii and Micronesia following maricultural advancements. Restocked individuals in the Philippines have successfully dispersed their own spawned larvae at least several hundred meters away after only 10 years.

title: Giant clam


text:
Vaginal bleeding

Vaginal bleeding is any expulsion of blood from the vagina. This bleeding may originate from the uterus, vaginal wall, or cervix. Generally, it is either part of a normal menstrual cycle or is caused by hormonal or other problems of the reproductive system, such as abnormal uterine bleeding.

Regular monthly vaginal bleeding during the reproductive years, menstruation, is a normal physiologic process. During the reproductive years, bleeding that is excessively heavy (menorrhagia or heavy menstrual bleeding), occurs between monthly menstrual periods (intermenstrual bleeding), occurs more frequently than every 21 days (abnormal uterine bleeding), occurs too infrequently (oligomenorrhea), or occurs after vaginal intercourse (postcoital bleeding) should be evaluated.

The causes of abnormal vaginal bleeding vary by age, and such bleeding can be a sign of specific medical conditions ranging from hormone imbalances or anovulation to malignancy (cervical cancer, vaginal cancer or uterine cancer). In young children, or elderly adults with cognitive impairment, the source of bleeding may not be obvious, and may be from the urinary tract (hematuria) or the rectum rather than the vagina, although most adult women can identify the site of bleeding. When vaginal bleeding occurs in prepubertal children or in postmenopausal women, it always needs medical attention.

Vaginal bleeding during pregnancy can be normal, especially in early pregnancy. However, bleeding may also indicate a pregnancy complication that needs to be medically addressed. During pregnancy bleeding is usually, but not always, related to the pregnancy itself.

The treatment of vaginal bleeding is dependent on the specific cause, which can often be determined through a thorough history, physical, and medical testing.

Etiology
The parameters for normal menstruation have been defined as a result of an international process designed to simplify terminologies and definitions for abnormalities of menstrual bleeding. The causes of abnormal vaginal bleeding vary by age.

Prepubertal
Bleeding in children is of concern if it occurs before the expected time of menarche and in the absence of appropriate pubertal development. Bleeding before the onset of pubertal development deserves evaluation. It could result from local causes or from hormonal factors. In children, it may be challenging to determine the source of bleeding, and "vaginal" bleeding may actually arise from the bladder or urethra, or from the rectum.

Vaginal bleeding in the first week of life after birth is a common observation, and pediatricians typically discuss this with new mothers at the time of hospital discharge. During childhood, one of the most common causes of vaginal bleeding is presence of a foreign body in the vagina which may be caused by normal self-exploration or can be indicative of sexual abuse. This is often associated with pelvic pain, foul discharge, or recurrent genitourinary infections. Other causes include trauma (either accidental or non accidental, i.e. child sexual abuse or molestation), urethral prolapse, vaginal infection (vaginitis), vulvar ulcers, vulvar skin conditions such as lichen sclerosus, and rarely, a tumor (benign or malignant vaginal tumors, or hormone-producing ovarian tumors). Hormonal causes include central precocious puberty, or peripheral precocious puberty (McCune–Albright syndrome), or primary hypothyroidism.

Genitourinary injury is also a common cause, and is often the most common cause of hospitalization or emergency department visits for prepubertal vaginal bleeding, comprising up to 45% of such cases. The most common genitourinary injury is the straddle injury, which often occurs during a fall, often on a sharp edge, and can cause lacerations between the labial folds.

While vaginal bleeding in children is typically alarming to parents, most causes are benign, although sexual abuse or tumor are particularly important to exclude. An examination under anesthesia (EUA) may be necessary to exclude a vaginal foreign body or tumor, although instruments designed for office hysteroscopy can sometimes be used in children with topical anesthesia for office vaginoscopy, precluding the need for sedation or general anesthesia and operating room time.

Background
In premenopausal women, bleeding can be from the uterus, from vulvar or vaginal lesions, or from the cervix. A gynecologic examination can be performed to determine the source of bleeding. Bleeding may also occur as a result of a pregnancy complication, such as a spontaneous abortion (miscarriage), ectopic pregnancy, or abnormal growth of the placenta, even if the woman is not aware of the pregnancy. This possibility must be kept in mind with regard to diagnosis and management.

Generally, the causes of abnormal uterine bleeding in premenopausal women who are not pregnant include fibroids, polyps, hormonal disorders such as polycystic ovary syndrome (PCOS), blood clotting disorders, and cancer. Infections such as cervicitis or pelvic inflammatory disease (PID) can also result in vaginal bleeding. Postcoital bleeding is bleeding that occurs after sexual intercourse. Lastly, a normal and common side effect of birth control includes vaginal spotting or bleeding.

Clinical guidelines (FIGO classification)
A more specific clinical guideline, called the PALM-COEIN system, has been developed by FIGO (International Federation of Gynecology and Obstetrics) to classify the causes of abnormal uterine bleeding. This acronym stands for Polyp, Adenomyosis, Leiomyoma, Malignancy and Hyperplasia, Coagulopathy, Ovulatory Disorders, Endometrial Disorders, Iatrogenic Causes, and Not Classified. The FIGO Menstrual Disorders Group, with input from international experts, recommended a simplified description of abnormal bleeding that discarded imprecise terms such as menorrhagia, metrorrhagia, hypermenorrhea, and dysfunctional uterine bleeding (DUB) in favor of plain English descriptions of bleeding that describe the vaginal bleeding in terms of cycle regularity, frequency, duration, and volume.

The PALM causes are related to uterine structural, anatomic, and histolopathologic causes that can be assessed with imaging techniques such as ultrasound or biopsy to view the histology of a lesion. The COEIN causes of abnormal bleeding are not related to structural causes.

PALM - Structural causes of uterine bleeding

 * Polyps: Endometrial polyps are benign growths that are typically detected during gynecologic ultrasonography and confirmed using saline infusion sonography or hysteroscopy, often in combination with an endometrial biopsy providing histopathologic confirmation. Endocervical polyps are visible at the time of a gynecologic examination using a vaginal speculum, and can often be removed with a minor office procedure.
 * Adenomyosis: Adenomyosis is a condition in which endometrial glands are present within the muscle of the uterus (myometrium), and the pathogenesis and mechanism by which it causes abnormal bleeding have been debated.
 * Leiomyoma (fibroids): Uterine leiomyoma, commonly termed uterine fibroids, are common, and most fibroids are asymptomatic. The presence of leiomyomas may not be the cause of abnormal bleeding, although fibroids that are submucosal in location are the most likely to cause abnormal bleeding.
 * Malignancy (pre-cancer and cancer): The Malignancy and Hyperplasia category of the PALM-COEIN system includes malignancies of the genital tract, including cancers of the vulva, the vagina, the cervix, and the uterus. Endometrial hyperplasia, included in this PALM category of abnormal bleeding, is more common in women who are obese or who have a history of chronic anovulation. When endometrial hyperplasia is associated with atypical cells, it can progress to cancer or occur concurrently with it. While endometrial hyperplasia and endometrial cancer occur most commonly among post-menopausal women, most patients with endometrial cancer have abnormal bleeding, and thus the diagnosis must be considered in women during the reproductive years.

COEIN - Non-structural causes of uterine bleeding
 * Coagulopathies (blood clotting disorders): Heavy menstrual bleeding can be related to coagulopathies. Von Willebrand disease is the most common coagulopathy, and most women with von Willebrand disease have heavy menstrual bleeding. Of women with heavy menstrual bleeding, up to 20% will have a bleeding disorder. Heavy menstrual bleeding since menarche is a common symptom for women with bleeding disorders, and in retrospective studies, bleeding disorders have been found in up to 62% of adolescents with heavy menstrual bleeding.
 * Ovulatory dysfunction: Ovulatory dysfunction or anovulation is a common cause of abnormal bleeding that may lead to irregular and unpredictable bleeding, as well as variations in the amount of flow including heavy bleeding. Endocrine, or hormonal, causes of ovulatory disorders include polycystic ovary syndrome (PCOS), thyroid disorders, hyperprolactinemia, obesity, eating disorders including anorexia nervosa or bulimia, or to an imbalance between exercise and caloric intake.
 * Endometrial: Endometrial causes of abnormal bleeding include infection of the endometrium, endometritis, which may occur after a miscarriage (spontaneous abortion) or a delivery, or may be related to a sexually-transmitted infection of the uterus, fallopian tubes or pelvis generally termed pelvic inflammatory disease (PID). Other endometrial causes of abnormal bleeding may relate to the ways that the endometrium heals itself or develops blood vessels.
 * Iatrogenic (caused by medical treatment or procedures): The most common Iatrogenic cause of abnormal bleeding relates to treatment with hormonal medications such as birth control pills, patches, rings, injections, implants, and intrauterine devices (IUDs). Hormone therapy for treatment of menopausal symptoms can also cause abnormal bleeding. Unscheduled bleeding that occurs during such hormonal treatment is termed "breakthrough bleeding" (BTB)  Breakthrough bleeding may result from inconsistent use of hormonal treatment, although in the initial months after initiation of a method, it may occur even with perfect use, and may ultimately affect adherence to the medication regimen.  The risk of breakthrough bleeding with oral contraceptives is greater if pills are missed.
 * Not classified: The Not Classified category of the PALM-COEIN system includes conditions that may be rare, or whose contribution to abnormal bleeding has not been well established or understood.

Pregnancy
Vaginal bleeding occurs during 15–25% of first trimester pregnancies. Of these, half go on to miscarry and half bring the fetus to term. There are a number of causes including complications to the placenta, such as placental abruption and placenta previa. Other causes include miscarriage, ectopic pregnancy, molar pregnancy, incompetent cervix, uterine rupture, and preterm labor. Bleeding in early pregnancy may be a sign of a threatened or incomplete miscarriage. In the second or third trimester a placenta previa (a placenta partially or completely overlying the cervix) may bleed quite severely. Placental abruption is often associated with uterine bleeding as well as uterine pain.

Vaginal bleeding during pregnancy can be normal, especially in early pregnancy. Light spotting early on in pregnancy can be a result of the fertilized egg implanting into the uterus. Additionally, during pregnancy, the blood supply to the cervix increases, which can cause the cervix to be more friable and bleed more easily than a non-pregnant woman's cervix. Because of this, some light spotting after intercourse can be normal. However, bleeding may also indicate a pregnancy complication that needs to be medically addressed and any vaginal bleeding during pregnancy should prompt a call to the patient's obstetric provider.

Perimenopausal
While many of the causes of premenopausal bleeding still apply to perimenopausal women, there is an additional cause of abnormal uterine bleeding in this category of women, which is the hormonal changes. Around age 40, women's hormones begin to change and this can cause variation in menstrual patterns. This can last for years, with menstrual periods lasting various lengths and coming at various intervals. Menopause is considered complete after a woman has gone 12 months without a menstrual period.

Postmenopausal
Endometrial atrophy, uterine fibroids, and endometrial cancer are common causes of postmenopausal vaginal bleeding. About 10% of cases are due to endometrial cancer. Uterine fibroids are benign tumors made of muscle cells and other tissues located in and around the wall of the uterus. Women with fibroids do not always have symptoms, but some experience vaginal bleeding between periods, pain during sex, and lower back pain.

Diagnostic evaluation
The cause of the bleeding can often be discerned on the basis of the bleeding history, physical examination, and other medical tests as appropriate. The physical examination for evaluating vaginal bleeding typically includes visualization of the cervix with a speculum, a bimanual exam, and a rectovaginal exam. These are focused on finding the source of the bleeding and looking for any abnormalities that could cause bleeding. In addition, the abdomen is examined and palpated to ascertain if the bleeding is abdominal in origin. Typically a pregnancy test is performed as well. If bleeding was excessive or prolonged, a CBC may be useful to check for anemia. Abnormal endometrium may have to be investigated by a hysteroscopy with a biopsy or a dilation and curettage.

In 2011, the International Federation of Gynaecology and Obstetrics (FIGO) recognized two systems designed to aid research, education, and clinical care of women with abnormal uterine bleeding (AUB) in the reproductive years. In postmenopausal vaginal bleeding, the primary goal of any diagnostic evaluations is to exclude endometrial hyperplasia and malignancy. Transvaginal ultrasonography and endometrial sampling are common methods for an initial evaluation. Guidelines from the American College of Obstetricians and Gynecologists (ACOG) recommend transvaginal ultrasonography as an appropriate first-line procedure to identify which patients are at higher risk of endometrial cancer. Endometrial sampling is indicated if having the following findings and/or symptoms:

 * Endometrial thickness greater than 4 mm
 * Diffuse or focal increased echogenicity (heterogeneity)
 * Failure to visualize the endometrium
 * Persistent or recurrent bleeding regardless of endometrial thickness

Endometrial sampling can be obtained either by an endometrial biopsy using an endometrium sampling device such as a pipelle or by dilation and curettage (D&C) with or without a hysteroscopy.

Complications
Severe acute bleeding, such as caused by ectopic pregnancy and post-partum hemorrhage, leads to hypovolemia (the depletion of blood from the circulation), progressing to shock. This is a medical emergency and requires hospital attendance and intravenous fluids, usually followed by blood transfusion. Once the circulating volume has been restored, investigations are performed to identify the source of bleeding and address it. Uncontrolled life-threatening bleeding may require uterine artery embolization (occlusion of the blood vessels supplying the uterus), laparotomy (surgical opening of the abdomen), occasionally leading to hysterectomy (removal of the uterus) as a last resort.

A possible complication from protracted vaginal blood loss is iron deficiency anemia, which can develop insidiously. Eliminating the cause will resolve the anemia, although some women require iron supplements or blood transfusions to improve the anemia.

Treatment
While many forms of vaginal bleeding are normal and do not require treatment, other forms will require medical attention. Hormonal management is usually the first option used to treat acute abnormal uterine bleeding. These hormonal medications include birth control pills, medroxyprogesterone acetate (brand name Depo-Provera), and conjugated equine estrogen. Long-term treatments include hormonal IUD insertion, birth control pills, progestin pills or progestin shots (Depo-Provera), and NSAIDs such as ibuprofen Certain medications may not be safe for certain women. Women with blood clotting disorders may also need to see a hematologist.

Surgical treatments may also be considered if the bleeding is severe or if there are reasons patients cannot take the hormonal medications listed above. These options include dilation & curettage, endometrial ablation, and hysterectomy (removal of the uterus). Hysterectomy will result in infertility, so surgical decisions will include women's preferences regarding future fertility when possible.

title: Vaginal bleeding


text: Category:Scottish surgeons

title: Category:Scottish surgeons