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44

Short answer: There is no benefit for their use in households. Long answer: These soaps (see here for the complete list) contain the so called quaternary ammonium compounds Benzalkonium chloride and Cetrimonium chloride which indeed have antimicrobial properties. While they do not promote resistance to these compounds (see reference 1), their use is still ...


22

Short version The heart has the ability to beat independently of the brain as long as it has oxygen. The heart will eventually stop beating as all bodily systems begin to stop working shortly after brain death. Remember the heart can beat, but your diaphragm and lungs wont. hence the cardiac muscles undergo asphyxiation and die off. However, immediately ...


17

Speaking of your DNA in general, you have alleles from all four of your grandparents. The 22 pairs of autosomes (non-sex chromosomes) can receive DNA from all four with random mixing. On a few chromosome pairs you may be missing alleles from one of your grandparents due to the randomness, but on average you will have about a quarter of your autosomes from ...


14

Chris has correctly identified the antibacterial agent in the hand soap depicted in the image in the question, and therefore his answer is superior as a direct answer. Nevertheless, other members of the Softsoap series of hand soap uses triclosan, 0.15% as their antibacterial agent, as seen in an image of their ingredient list on the reverse of the bottle. ...


13

One important point that you might not be considering is the heat of vaporization. You may be aware that while it normally takes 4.18 J (1 calorie) of heat to raise 1 gram of water 1 °C, it takes around 2250 J of heat to raise 1 g of water from liquid at 99.5 °C to gas at 100.5 °C, due to the energy needed to go from a liquid to a gas. - What you may not ...


9

Short answer Various inhalants, most notably organic solvents including those used in paint and glue suppress appetite. Background From the Division of Alcohol and Drug Abuse I learned the following: Initial effects [of various inhalants] include nausea [...], and a loss of appetite. And the Humanitarian Irin News reports the following on Nepali ...


9

Short answer People with androgen insensitivity syndrome do not have a functional uterus and cannot bear a child. Background Androgen-insensitive genetic males may develop female genitalia and internal female reproductive organs. However, in both partial androgen insensitivity syndrome (PAIS) and complete androgen insensitivity syndrome (CAIS) the uterus is ...


9

Developmentally, the urinary and genital systems (typically you will hear them referred to as "urogenital system") are derived from the same embryonic tissue, the intermediate mesoderm. The embryonic kidneys are drained by the mesonephric duct in both females and males. This embryonic tissue also gives rise to the ovaries and testes. The mesonephric duct ...


8

Sydney Ringer showed in 1882 that when the heart, when separated from the body and immersed in lactated Ringer's solution, or even isotonic saline solution, will beat because it has its own pacemaker systems at the level of the Sinoatrial node and Atrioventricular node. This activity will continue until there is insufficient ATP to support it energetically. ...


8

Short answer In terms of visual function, the low-tier primary visual cortex and high-tier frontal cortex are inactivated. The activity of the intermediate ventral stream and limbic regions are increased, apparently uncoupling low- and high-level vision processing from the system. Background The sleep stage where visualizations (dreaming) occur is called ...


7

The yellow color comes from the accumulation of Bilirubin in the body. Bilirubin is a breakdown product of hemoglobin (contained in erythrocytes, also known as red blood cells, and responsible for the oxygen transport in the body). (This is also the reason why bruises get colored, as the blood which was released into the skin gets removed.) As erythrocytes ...


6

This phenomena has nothing to do with any different kinds of receptors. When we are wet, we have lots of water on our surface. The evaporation of water causes cooling. Blowing wind tends to make evaporation faster. So, even if wind blows at normal temperature, we feel cold. If we are not wet, there is some water on our body surface. This water is low in ...


6

When our skin is exposed to the sun, this can cause some damage in the upper layers of skin. This activates DNA damage repair and also induces signalling towards the melanocytes (which produce the pigment). Signalling means the excretion of signalling molecules (mostly alpha-Melanocyte stimulating hormone, aMSH) which binds to the MC1R receptor (melanocortin ...


5

Both your linked fact from the University of Arkansas When you sneeze, the intrathoracic pressure in your body momentarily increases. This will decrease the blood flow back to the heart. The heart compensates for this by changing its regular heart beat momentarily to adjust. However, the electrical activity of the heart does not stop during the sneeze. ...


5

You may be interested to look into the Old friends hypothesis, since this is related to how the human immune system may respond to reduced biodiversity in the microbiota. The basic idea is that the human immune system is developed by exposture to the microbiota, and without exposture to organisms from our evolutionary past, immune system regulation might ...


5

Short answer Water of 180 oF (82 oC) causes immediate scalding (thermal burn wounds). Background The severity of a scald injury depends on the temperature to which the skin is exposed, and for how long. Residential water heaters warm up tap water typically to 120 oF (48 oC). At this temperature, the skin of adults requires an average of five minutes of ...


5

It is logically clear that the ankle could only partly be analyzed in the group of joints that are below its height. There is no direct way to measure the pressure on ankle joint (on talus bone), but from the logic it is clear that it should be the point of highest pressure in the group of points lister in the question, however the pressure is distributed ...


5

These combination contraceptives contain two substances: Estrogen and progestin (a synthetic progesterone). Both are used together to overcome the negative effects of single substance drugs as acne or sickness. The risk for blood clots is know for quite a while (see reference 1 and 2) and is generally caused by raised levels of clotting factors (especially ...


5

As other answers and comments have stated the reason that you feel cooler when the wind is blowing (wind chill factor often gets talked about on the news) is because evaporation is speed up by the wind. The reason that this evaporation causes cooling (explained in more detail here) is because when water evaporates, that water takes its energy with it. That ...


4

Short answer Oxytocin release has been associated with the cutaneous low-threshold (CT) afferent fibers in hairy skin. Background Oxytocin is released from the paraventricular nucleus in the brain in response to low intensity stimulation of the skin, such as touch, stroking and warm temperatures. In a recent review Uvnäs-Moberg et al. (2015) report that ...


4

It's actually very simple. You misunderstood the term polymorph in this situation. A microsatellite is a sequence composed of a short repeated DNA motif. A polymorph satellite is then simply a microsatellite varying in length between individuals, i.e. composed of more or less repeats of the motif. The flanks of the microsatellite are the DNA sequences ...


4

I was wondering if a heart keeps beating if it is separated from the body? Yes, it does. Here's a video showing it (don't click if you're squeamish!): https://www.youtube.com/watch?v=NEuSCPifKhA It's a classical physiology experiment to remove a heart and keep it beating for some time in a jar with liquid solution. In fact, acetylcholine, the first ...


4

You don't get hydrated by breathing moist air. That may at best hydrate your respiratory tract. You should drink more water in dry weather because the body gets dehydrated more. Humid weather is not hotter, it just feels more uncomfortable but dry heat is actually more harmful because it dehydrates you (not in the sense of extreme heat).


3

There don't appear to be many robust studies on this, but this study by De Longe et al in 2004 suggests that, whilst the volume of the ejaculate is increased after 5-days of abstinence (in most participants), for many this did not increase further after 8-days [1]. Here are the 11 participant included (along the x-axis), and for each participant there are ...


3

In order to clear some issues with the question and answers I add this one. The question itself was "will a heart keeps beating if it is separated from the body?" The answer to this question as it was asked: No, the heart removed from the body "as is" will stop beating almost immediately. Denervation and stopping oxygen and electrolytes supply will cause ...


3

I think you pretty much nailed the problem. If I understand correctly, you are just confused about the approximation that your textbook does, an approximation that is correct but not needed. Let me restate the solution to the problem first. Resolution of the problem As you said the frequency of sick people $\frac{1}{300} = 2pq + q^2$ in this case, where $q ...


3

Short answer External stimuli can drive autonomic responses. Background The autonomic nervous system is a visceral sensory and motor system. The viscera are the internal organs. Virtually all visceral reflexes are mediated by local circuits in the brain stem or spinal cord (Fig. 1). It is one of two major subdivisions of the nervous system; the other being ...


3

Simethicone is one example. It is a mixture of silica gel and dimethicone (polydimethyl siloxane); they are individually inert too. Simethicone/dimethicone is used as antigas (they help the gas bubbles coalesce). It does have a laxative effect, though.


3

First, one should mention types of skin: skin type defines how the person will tan - Second, the solar radiation (UV) absorbed by sun defines the amount of melanin produced by melanocytes of the skin to protect the skin = melanogenesis (which in turn depends on skin type). When the solar exposure diminish, the natural repair processes causes ...


2

Let's consider all the options. X-linked recessive: I:2 is a carrier and II:5 is also a carrier, and I:1 is affected. Everyone who marries into this family(except for II:2, lucky guy. He better not have any sons though.) is a carrier for the same genetic disorder. While it does work, it's vastly less likely than the other options. Observe: II:4 is affected, ...



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