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Everything posted by SMF

  1. After I lost my access to a university library I find this problem to be very frustrating. It seems that because we all pay, with our taxes, for most of the basic science being done, we should have free access to the published research results. I realize that this is a sticky problem because scientific journals have to be able to cover their costs, but there should be some way to deal with this. I would be willing to pay more in my taxes to get free access, but this is unlikely to come to pass. I always thought that some of the big freeloaders using this system, the various high tech industries that use tax supported research findings at no cost to make new products for profit, might cover the expense. And, so it goes. SM
  2. This is very interesting. If I correctly interpret what Swansont is saying, the bouncing magnet would continue to bounce for a while without any more energy input, but the bounce would eventually damp out. I wonder how long this would take if done in a vacuum. I also presume that this would be the only "friction" loss in rare earth maglev bearings being contemplated for very low wind, vertical shaft, wind generators and other devices. SM
  3. JohnB: You continue to cast aspersions at Dr. Trenberth without providing any credible evidence of what he actually said regarding recent Australian weather. Can't you come up with any source to support your complaints so that the readers here can see what he said in context? I am not interested in with what you think he said, I want to know what he actually said. Why are you so reluctant to provide this information? What I have seen are nicely reasoned statements regarding how the, relatively small, addition of global warming to weather has probably affected some recent events. All very reasonable, as I would expect from a successful scientist. Be careful, all of his public statements are on the record. A simple addition that makes me wonder about your objectivity. A private e-mail is not casting aspersions at somebody, it is a private conversation that, in this case, was illegally stolen and illegally exposed to the general public. Are your private conversations about individuals, such as Dr. Trenberth, casting aspersions or are they just your personal and private opinions. Further, if you were to actually read the UK freedom of information act (I have) you would easily be able to see that the data requests, made public in the UEA hack, were not legal. This has been supported in several investigations, but the outcome was obvious if one knows the law. SM
  4. JohnB: Your assessment of my knowledge regarding climate issues on the basis of two short paragraphs is demeaning. Your multiple negative references to what Kevin Trenberth, a highly respected climate scientist, has said have been asserted without any reference to what he actually said, where he said it, and the full context within which he said it. This is highly inappropriate in a science forum, don’t you think? Finally, I will reassert that you are putting too much emphasis on the shape of the shaft of the hockey stick. There is quite a bit of information about it that can be jiggled up and down a little as research continues, but it is the blade that should be the center of attention. SM
  5. An important corollary of science is that correlation is not causation. Because there is, as yet, no mechanism identified that mediates an anti cancer effect of aspirin, this finding is in a sort of scientific limbo. Until there is a causal mechanism there are a variety of other explanations that should be treated as plausible. An example might be that people who are regularly taking aspirin are those who are more concerned about their health or have been advised by their physician to take it for the cardiovascular benefits. This group might be much more concerned about their health and therefore also doing other healthful behaviors and/or have good health care that would involve advising them on healthy activities. The finding is very interesting and I am looking forward to where it will lead. SM
  6. JohnB. You are, admittedly, using local weather to make arguments about global climate. This doesn’t seem to be appropriate. Finding specific local regions that differ from the global mean, or predictions resulting from warming, is a non-issue. Also, all of the big factors that affect climate are pretty much known and this is why the current warming is well researched. What specific combination of these known factors that caused local or global changes in the past, prior to the instrumental record, are less sure, although there are some pretty good hypotheses that have support. It doesn’t seem that knowing exactly how warm or cold Europe was from the paleoclimate data, for example, is very relevant to the current situation. SM
  7. Needimprovement. If the definition of mind is the sum of our conscious experience, then the idea of mind affecting matter is quite simple. For example, as I sit here I am reading your post and thinking about it (a process of the mind), and then typing this on my computer, a physical act that influences matter. Besides this, I am not sure what you are asking. The mind is an epiphenomenon of the brain and is a component of the brain. The one thing that is different about all nervous systems and computers, for that matter, is that they manipulate information. Information is dependent upon matter, but not necessarily dependent on any particular type of matter. Mrs Zeta. Following my statement above, stress is an information state in brains that sets a critter up for dealing with the cause of the stress by automatically adjusting different body systems, which is matter manipulation. We beans (humin beans) have inappropriate stress responses because our evolutionary past tuned us up for a completely different environment. What is called mind-body therapy is actually mind influencing mind. One’s mind can influence cancer by deciding to get therapy, but otherwise these therapies help patients deal with the disease in a psychological sense. I don’t get the epigenetic reference at all. SM
  8. The country that is least likely to record suicides as a cause of death would come out number one. This question might be more answerable if it were restricted to countries that keep good records. Also, how do you define happiness in this context. Someone could argue that having control of ones own life could lead to more happiness. Sorry to mess up an interesting question, but ... SM
  9. What you need is a sound activated photographic flash unit. Activating it at 100 meters with a starter pistol should give you about a third of a second difference between the flash and sound. You can figure this pretty accurately for a specific distance, temperature, and air density. This sort of flash setup is rare but available. I would try talking to a professional photographer or to someone who is a gun hobbyist. They may know someone who can help you calibrate your device in real time. For a less accurate test you could use a camera to flash your device up close and then making a loud noise two seconds, or whatever, later. SM
  10. Anura, I am sorry, but your question was a bit vague. Vasa vasora mostly arise as small branches from the artery that is being supplied. This is required, for arteries (mostly), because the many smooth muscle and elastin layers in the media layer of arteries are designed to contain blood, and this blocks diffusion. Also, a component of capillary beds (not the ones in the lungs) is that they are leaky so that some proteins, immune molecules, and immune cells can gain access to all of the cells in the body. Vasa vasora for the wall structure of some large veins originate from the accompanying artery. Arteries and veins that are connected at their terminus by a capillary bed usually travel together side by side. SM Dragonstar57, yes the cells in the walls of alveoli get their O2 directly because the blood entering the lung alveolar capillary beds is deoxygenated. Lung tissue is pretty amazing. On the other hand the walls of bronchi and bronchioles, connective tissue, and large arteries and veins in the lung that present a much larger diffusion distance to the living cells and therefore require a separate blood supply that enters the lung separately. SM
  11. In light of this question it interesting to note that a hydroelectric dam is using gravity to make electricity. This is quite efficient because the sun does the lifting of the water for free. However, water batteries that involve pumping water up hill to a reservoir for later power generation are already in use. They are about 75% efficient, which is not bad. What makes this strategy cost effective is the fact that many power sources, such as nuclear or coal, are difficult to modulate according to changes in the load, so there is a lot of wasted power during off peak times. The off peak power can be stored by pumping water up hill. SM
  12. Windex works just fine for dirty or immersion oil covered slides. SM
  13. Ones heart pumps blood into arteries. The arteries branch and branch until they are small (arterioles). The blood flows from arterioles into a capillary bed. Capillaries are a very small vein and are where gasses (oxygen and carbon dioxide), nutrients, and waste products are exchanged between cells and the blood. Blood collected from capillary beds combine in larger and larger veins to return the blood to the heart to be pumped again. The heart is two separate pumps. One half pumps blood through the capillary beds in lung tissue to exchange gasses and oxygenate the blood, while the other half of the heart pumps oxygenated blood through the rest of the body. So Heart--> arteries --> capillaries --> veins --> heart. SM
  14. I presume that you already know that an action potential progresses down an axon incrementally as depolarization of a section of membrane initiates depolarization next door, and this triggers further depolarization. Membranes are usually negatively charged on the inside, relative to the outside, so depolarization makes the interior less negative, or even positively charged. Changes in membrane potential is produced by movement of ions across the membrane. Depolarization to a trigger point opens voltage sensitive sodium ion channels and this initiates an action potential whereby the entry of positive sodium ions, across the membrane, depolarizes it more (goes positive), and then potassium ion channels open to release potassium from the axon to recharge the membrane to a negative interior state. In myelinated axons the sections between the nodes are sealed off so that ions cannot cross the membrane. Instead the depolarization, carried by an ionic current, progresses longitudinally down the axon until the next small segment of node membrane, where ions can cross, and an action potential is initiated. This is a bit simplistic, but the deal is that the spread of depolarization down the axon to the next node is much faster than the progression of an action potential, so myelinated axons conduct information at a much higher speed. Said slightly differently-- in an unmyelinated axon the spread of depolarization of an action potential progresses from one house to the one next door, but in a mylelinated axon the spread of depolarization, between nodes, is a whole block to the next cross street. SM
  15. As a point of nomenclature, a "nerve" consists of a bundle of axons enclosed in a sheath. Both myelinated and unmyelinated axons are capable of conducting an action potential in both the orthodromic (also anterograde) and antidromic (also retrograde) directions. However, in almost all natural circumstances an action potential in both myelinated and unmyelinated axons progresses in the orthodromic direction, that is, from the neuron cell body down the axon to the synaptic terminal.SM
  16. Dermatome refers to the pattern of sensory innervation from the dorsal root of a particular spinal cord segment. The ventral motor root of the same segment joins with the sensory root to travel to the periphery. Some axons from adjacent dermatomes usually join in a peripheral nerve to reach nearby regions while smaller nerve branches divide off at appropriate points to supply their region with sensory and motor innervation. The L1 branch doesn't provide very much motor innervation. SM
  17. A nice piece in Physiological Reviews by John M. Russell (2000) on the pump/atpase has a section on discovery and characterization. Also the reference list should allow a reference evidence train to just about anything known about the pump and its relatives. It is full text online at- http://physrev.physiology.org/content/80/1/211.full
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