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January 15 Information
194.114.146.227 ( talk) 07:06, 15 January 2014 (UTC)
- When people refer to " antibodies" they are typically referring specifically to proteins affected by V(D)J recombination, which cannot be inherited genetically (although a mother can pass some antibodies directly to her infant child). However, there are other components of the immune system, such as the complement system, which are heritable. In brief, the complement system is a set of genes that are pre-encoded to recognize and combat certain pathogenic microorganisms, although they still work better if accompanied by a typical antibody response. See also Pattern recognition receptor and antigen. Someguy1221 ( talk) 08:38, 15 January 2014 (UTC)
תודה על התשובה (Thank you for the answer) 5.28.161.105 ( talk) 11:31, 15 January 2014 (UTC)
- Another interesting feature, which is heritable but prone to variation, is human leukocyte antigen (which is the human version of the major histocompatibility complex). --— Cyclonenim | Chat 10:37, 16 January 2014 (UTC)
Why does the Systeme International use the Ampere, the unit of Current, as a base unit instead of the Coulomb, the unit of Charge? I would think that charge would be the basic fundamental quantity, comparable to length, time and mass, while current is simply charge/time. Inkan1969 ( talk) 16:33, 15 January 2014 (UTC)
- Arguably, electric charge is a more derived property and is more difficult to directly measure than electric current. Besides, you can have electric current even if no charge moves. S.I. defines electric current in terms of its mechanical effect, not in terms of its constituent motion of charge. Nimur ( talk) 16:45, 15 January 2014 (UTC)
- Inkan1969's question is a good one. I have often pondered the same thing. The formal definitions of the Ampere and the Coulomb establish that the Ampere is the fundamental unit, and the Coulomb is the derived unit. However, I imagine that it is easier for a young student to comprehend electric charge (the Coulomb) first; and then to comprehend electric current (the Ampere). I'm not a teacher, but if I were a teacher of physics to teenagers I would first introduce the concept of electronic charge and the Coulomb, and secondly introduce the concept of electric current and the Ampere and the properties associated with an electric current. Dolphin ( t) 05:16, 16 January 2014 (UTC)
- Which is considered the base unit may change with the proposed redefinition of SI base units. The "why" is probably more determined by measureability considerations than which could be consider more fundamental. — Quondum 07:14, 16 January 2014 (UTC)
- Yes - having worked in a metrology lab at one point I can confirm that the choice of base units has very little to do with the ease with which the concepts can be taught and is only somewhat related to how fundamental they are as concepts (basically you want to reduce the interdependence of the base units as much as practical, which does lead one towards more fundamental units in general). The main consideration is indeed measurability - specifically minimising the measurement uncertainty and ensuring the measured value is stable over time and between different laboratories (which is why there is so much effort going on to redefine the kilogram as something based on fundamental constants, rather than as the mass of a block of platinum-iridium in Paris). Equisetum ( talk | contributions) 14:01, 16 January 2014 (UTC)
- It would be logically more reasonable if the kilogram could be defined by counting some number of atoms of some particular isotope - and charge be defined by counting the number of excess electrons present. This would reduce those units to simple integer numbers with essentially perfect and unchanging precision. We've already done that with the definition of a second ("the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium133 atom"). The problem is in getting the required precision for normal use - and the theoretical reproducibility. Making a 1kg mass out of some specific number of 100% pure, single-isotope atoms is a lot harder than making a lump of metal that's more or less the same weight as some other lump of metal. Similar problems exist with dishing out some exact number of electrons to make a standard charge. So in many ways, we're constrained to definitions of units that are practically realizable - and that's more of a technological limitation than it is one of picking the best set of units and definitions conceptually. SteveBaker ( talk) 14:36, 16 January 2014 (UTC)
What is the scientific basis for the claim that studying individually is better than studying in a group?
What is the scientific basis for the claim that studying individually is better than studying in a group? And under what conditions is this so? 140.254.227.120 ( talk) 16:45, 15 January 2014 (UTC)
- Who makes this claim, and in what context? It seems like too much of a generalisation to make any 'scientific' assertions one way or another. AndyTheGrump ( talk) 16:52, 15 January 2014 (UTC)
- But a study has shown that that is the case! I just can't seem to find the actual article again. I swear it's not a dream! :( 140.254.227.120 ( talk) 17:08, 15 January 2014 (UTC)
- I was hoping I could find some support or doubts on that study, since scientific studies are usually tentative. 140.254.227.120 ( talk) 17:10, 15 January 2014 (UTC)
- When an article in the media starts with "A recent study shows", it's best to take it with a giant grain of salt. p value for "significance" was set intentionally low so that studies would pick up things worthy of further examination, NOT at all to determine if they are actually real or true. To do the latter, you have to independently replicate the results a few times. Actually having a quick look, the Misunderstandings section of our p value article seems to cover it pretty well. Vespine ( talk) 21:53, 15 January 2014 (UTC)
- I could certainly see both advantages and disadvantages to group study sessions:
- ADVANTAGES = Others can explain things to you which might be unclear from the lectures and/or book and/or labs.
- DISADVANTAGES = Not tailored to your own weaknesses. Presumably you will study more where you know you are deficient.
- In other cases, it might depend on the study group. One that encourages you to study when you want to stop would help, while a group that is always goofing off is not at all helpful. Also, I might apply the same rule I apply to learning chess, where I think it's best to play those who are just slightly better than you. They have something to teach you, yet are not too advanced to understand. Also, real experts often don't want to bother explaining "the obvious". StuRat ( talk) 22:14, 15 January 2014 (UTC)
- Citing the anonymous authority of a study someone might remember does not constitute a scientific approach. The result of such a study would itself be qualified by whether it was done by an individual or a group. A scientific method of studying the claim would be to design and carry out a Blind experiment that removes the influence of preconceived notions. This falls within the article about Educational research and a hypothesis that why one study method is better than another falls under Educational psychology. 84.209.89.214 ( talk) 22:26, 15 January 2014 (UTC)
- The trouble with this sort of study, for things that are as individual as study methods is that the study can usually only conclude that "on average" one method is better than the other for the population studied. This might just mean that method A is better for 40% of the study sample, for 30% of people it makes no detectable difference, and for 30% of people method B is better. Interpretation is further complicated by the fact that you can't guarantee, without close reading of the relevant paper, that the study is sampling a population of which you are a member - maybe the study was on humanities students, and you are a physics student. The results of these studies are potentially useful for schools and education authorities who need to find the approaches which are effective for the maximum number of people while being cheap enough to implement, but as an individual you are much better off trying different techniques and seeing which work best for you (ideally in a semi-formal manner to remove as many biases as possible). Equisetum ( talk | contributions) 12:15, 16 January 2014 (UTC)
| Science desk | ||
|---|---|---|
| < January 14 | << Dec | January | Feb >> | January 16 > |
| Welcome to the Wikipedia Science Reference Desk Archives |
|---|
| The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
January 15 Information
194.114.146.227 ( talk) 07:06, 15 January 2014 (UTC)
- When people refer to " antibodies" they are typically referring specifically to proteins affected by V(D)J recombination, which cannot be inherited genetically (although a mother can pass some antibodies directly to her infant child). However, there are other components of the immune system, such as the complement system, which are heritable. In brief, the complement system is a set of genes that are pre-encoded to recognize and combat certain pathogenic microorganisms, although they still work better if accompanied by a typical antibody response. See also Pattern recognition receptor and antigen. Someguy1221 ( talk) 08:38, 15 January 2014 (UTC)
תודה על התשובה (Thank you for the answer) 5.28.161.105 ( talk) 11:31, 15 January 2014 (UTC)
- Another interesting feature, which is heritable but prone to variation, is human leukocyte antigen (which is the human version of the major histocompatibility complex). --— Cyclonenim | Chat 10:37, 16 January 2014 (UTC)
Why does the Systeme International use the Ampere, the unit of Current, as a base unit instead of the Coulomb, the unit of Charge? I would think that charge would be the basic fundamental quantity, comparable to length, time and mass, while current is simply charge/time. Inkan1969 ( talk) 16:33, 15 January 2014 (UTC)
- Arguably, electric charge is a more derived property and is more difficult to directly measure than electric current. Besides, you can have electric current even if no charge moves. S.I. defines electric current in terms of its mechanical effect, not in terms of its constituent motion of charge. Nimur ( talk) 16:45, 15 January 2014 (UTC)
- Inkan1969's question is a good one. I have often pondered the same thing. The formal definitions of the Ampere and the Coulomb establish that the Ampere is the fundamental unit, and the Coulomb is the derived unit. However, I imagine that it is easier for a young student to comprehend electric charge (the Coulomb) first; and then to comprehend electric current (the Ampere). I'm not a teacher, but if I were a teacher of physics to teenagers I would first introduce the concept of electronic charge and the Coulomb, and secondly introduce the concept of electric current and the Ampere and the properties associated with an electric current. Dolphin ( t) 05:16, 16 January 2014 (UTC)
- Which is considered the base unit may change with the proposed redefinition of SI base units. The "why" is probably more determined by measureability considerations than which could be consider more fundamental. — Quondum 07:14, 16 January 2014 (UTC)
- Yes - having worked in a metrology lab at one point I can confirm that the choice of base units has very little to do with the ease with which the concepts can be taught and is only somewhat related to how fundamental they are as concepts (basically you want to reduce the interdependence of the base units as much as practical, which does lead one towards more fundamental units in general). The main consideration is indeed measurability - specifically minimising the measurement uncertainty and ensuring the measured value is stable over time and between different laboratories (which is why there is so much effort going on to redefine the kilogram as something based on fundamental constants, rather than as the mass of a block of platinum-iridium in Paris). Equisetum ( talk | contributions) 14:01, 16 January 2014 (UTC)
- It would be logically more reasonable if the kilogram could be defined by counting some number of atoms of some particular isotope - and charge be defined by counting the number of excess electrons present. This would reduce those units to simple integer numbers with essentially perfect and unchanging precision. We've already done that with the definition of a second ("the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium133 atom"). The problem is in getting the required precision for normal use - and the theoretical reproducibility. Making a 1kg mass out of some specific number of 100% pure, single-isotope atoms is a lot harder than making a lump of metal that's more or less the same weight as some other lump of metal. Similar problems exist with dishing out some exact number of electrons to make a standard charge. So in many ways, we're constrained to definitions of units that are practically realizable - and that's more of a technological limitation than it is one of picking the best set of units and definitions conceptually. SteveBaker ( talk) 14:36, 16 January 2014 (UTC)
What is the scientific basis for the claim that studying individually is better than studying in a group?
What is the scientific basis for the claim that studying individually is better than studying in a group? And under what conditions is this so? 140.254.227.120 ( talk) 16:45, 15 January 2014 (UTC)
- Who makes this claim, and in what context? It seems like too much of a generalisation to make any 'scientific' assertions one way or another. AndyTheGrump ( talk) 16:52, 15 January 2014 (UTC)
- But a study has shown that that is the case! I just can't seem to find the actual article again. I swear it's not a dream! :( 140.254.227.120 ( talk) 17:08, 15 January 2014 (UTC)
- I was hoping I could find some support or doubts on that study, since scientific studies are usually tentative. 140.254.227.120 ( talk) 17:10, 15 January 2014 (UTC)
- When an article in the media starts with "A recent study shows", it's best to take it with a giant grain of salt. p value for "significance" was set intentionally low so that studies would pick up things worthy of further examination, NOT at all to determine if they are actually real or true. To do the latter, you have to independently replicate the results a few times. Actually having a quick look, the Misunderstandings section of our p value article seems to cover it pretty well. Vespine ( talk) 21:53, 15 January 2014 (UTC)
- I could certainly see both advantages and disadvantages to group study sessions:
- ADVANTAGES = Others can explain things to you which might be unclear from the lectures and/or book and/or labs.
- DISADVANTAGES = Not tailored to your own weaknesses. Presumably you will study more where you know you are deficient.
- In other cases, it might depend on the study group. One that encourages you to study when you want to stop would help, while a group that is always goofing off is not at all helpful. Also, I might apply the same rule I apply to learning chess, where I think it's best to play those who are just slightly better than you. They have something to teach you, yet are not too advanced to understand. Also, real experts often don't want to bother explaining "the obvious". StuRat ( talk) 22:14, 15 January 2014 (UTC)
- Citing the anonymous authority of a study someone might remember does not constitute a scientific approach. The result of such a study would itself be qualified by whether it was done by an individual or a group. A scientific method of studying the claim would be to design and carry out a Blind experiment that removes the influence of preconceived notions. This falls within the article about Educational research and a hypothesis that why one study method is better than another falls under Educational psychology. 84.209.89.214 ( talk) 22:26, 15 January 2014 (UTC)
- The trouble with this sort of study, for things that are as individual as study methods is that the study can usually only conclude that "on average" one method is better than the other for the population studied. This might just mean that method A is better for 40% of the study sample, for 30% of people it makes no detectable difference, and for 30% of people method B is better. Interpretation is further complicated by the fact that you can't guarantee, without close reading of the relevant paper, that the study is sampling a population of which you are a member - maybe the study was on humanities students, and you are a physics student. The results of these studies are potentially useful for schools and education authorities who need to find the approaches which are effective for the maximum number of people while being cheap enough to implement, but as an individual you are much better off trying different techniques and seeing which work best for you (ideally in a semi-formal manner to remove as many biases as possible). Equisetum ( talk | contributions) 12:15, 16 January 2014 (UTC)