Bats are generally wonderful creatures and helpful to us. For example, they eat lots of insects that are annoying (like mosquitoes) and pollinate lots of plants. Of course, they also eat lots of good (for us humans) insects but the insects still seem to be able to fulfill their environmental niches so all is good.
And they are flying mammals which is, of course, cool.
But bats also transmit virus to us, which do us lots of damage. As the video explains as we have intruded into bat territory and chopped down their natural feeding spots we have come into contact with them more. And because bats evolved to be very resilient to virus and they live in large colonies (for easy transmission of the viruses to lots of bats) they can host viruses and survive long enough to infect lots of other bats, and to infect us if we meet them.
I actually didn’t know this (mentioned in the video): most viruses have a very difficult time surviving even with temperatures a bit above the normal human temperature (98 degrees Fahrenheit). Bats, while they fly, have internal temperatures that soar to 104 degrees (40 degrees centigrade) which kills off most viruses, but certain hardy viruses survive. This also explains why we run fevers when we are sick (which then can kill off viruses) – which I am sure I learned at some point but I forgot. But for the bat viruses that strategy doesn’t work.
This illustrated webcast introduces the microscopic arsenal of weapons and warriors that play a role in the battle for your health.
TED education has been putting out some good videos which is a wonderful thing to see. It is wonderful to let people everywhere (kids and adults) that are interested in learning (and that have internet access) can learn about the world around us. Traditional educational institutions have not done much with this opportunity to broaden their impact.
The video looks at the cells reaction to a virus infiltrating the cell.
The dopamine reaction to sugar leads us to seek out that good feeling. Sugars can lead us astray by encouraging us to seek more than is good for us.
A sensible explanation is that sugars provide high calories and were rare and so the more we could find the better. Evolution takes a long time to adjust though (and of course misses things that don’t affect passing on successful genes) so long (in our human timeframe, short in evolutionary timeframe) after we have far too much sugar available our brains our encouraging us to eat all we can find. This of course, at best, is a very oversimplified view.
Very cool site for learning about biology. I have tried the courses offered by Coursera but they are too structured for my taste. I want to be able to learn at my pace and dip into the areas I find interesting. Coursera is more like a real course, that has weekly assignments and the like.
Survivebio is a resources that matches my desires exactly. You can go and learn about whatever topics you desire, when you desire. The site offers webcasts, games, flashcards, chapter outlines, practice tests and a forum to discuss the ideas.
In this webcast, Paul Andersen discusses the specifics of phylogenetics. The evolutionary relationships of organisms are discovered through both morphological and molecular data.
The aim of the SurviveBio web site is to aid AP (and college) biology students. But it is also a great resource to learn about biology if you are interested in that topic. Hopefully they will add more webcasts. The site uses webcasts from Bozeman Science which has a huge number of very good videos on biology and also, chemistry, physics, earth science, statistics, anatomy and physiology.
Before you leave these portals to meet less fortunate mortals,
There’s just one final message I would give to you.
You all have learned reliance on the sacred teachings of science
So I hope through life you never will decline in spite of philistine defiance
To do what all good scientists do.
Make it your motto day and night.
Experiment and it will lead you to the light.
The apple on the top of the tree is never too high to achieve,
So take an example from Eve, experiment.
Be curious, though interfering friends may frown,
Get furious at each attempt to hold you down.
If this advice you only employ, the future can offer you infinite joy
Experiment and you’ll see.
To capture the interactions a full factorial requires an ever larger number of experimental runs to be complete. Assessing 4 factors requires 16 runs, 6 would require 64 and 8 would require 256. This can be expensive and time consuming. Obviously one method is to reduce the number of factors to experiment with. That is done (by having those knowledgable about the process include only those factors worth the effort), but if you still have, for example, 8 very important factors using a fractional factorial design can be very helpful.
And as George Box says “What you will often find is that there will be redundant factors… and don’t forget about those redundant factors. Knowing that something doesn’t matter is almost as important as knowing what does.” If you learn a factor isn’t having an affect you may be able to save money. And you can eliminate varying that factor in future experiments.
Tim examines some questions on science and exercise and health in the webcast. He shows the problem with drinking too much during exercise and the correlation of hospital admissions correlated to the sport drinks marketing and changing of the official drinking guidelines. He also discusses the outdated ideas related to lactic acid and muscles.
He is currently studying the science of food and human health and is skeptical of low fat health claims: “No evidence that dietary fat is related to heath disease.” He is certainly more knowledgable than I but I would still be cautious of completely accepting that premise. It does seem to me there is lots of evidence that claims of causation between eating a high fat diet and heart disease were too strong (many other factors were critical – such as weight, exercise, genetics, unsaturated fat v. saturated fat…).
Tim Noaks: “50% of what we teach is wrong; the problem is we don’t know which 50% it is. Our job as educated people is to spend our lifetime trying to figure out which 50% is which. Until it is disproven accept that for which the evidence appears solid and logical and is free of covert or overt conflicts of interest, because unfortunately industry is driving what you believe in many many things. But don’t ever dismis lightly that for which there is credible evidence… and there is such clear evidence the diets we are eating are horrendous.”
Interesting facts: I didn’t know that we require 13 minerals or that alcoholic beverages contain amounts of all the minerals we need. An amazing fact: the average person walks the equivalent of 3 times around the earth in a lifetime.
trace amounts needed
Cobalt (as Vitamin B12) – 2.4 mcg
Copper – 1,156 mcg
Iodine – 150 mcg
Iron – 8 mg
Manganese – 1.8 mg
Niacin – 14 mg
Riboflavin – 1.1 mg
Selenium – 55 mcg
Thiamin – 1.1 mg
Zinc – 8 mg
Chromium?, Molybdenum? Fluoride?
Frankly, in my quick looks around the internet I am not sure what they base the claim we need only 13 minerals on. It seems we need trace amounts of more minerals – did they just ignore those not in alcohol?
I couldn’t find good sources confirming just what minerals are needed. Many list some minerals but don’t list others. I am not really sure what the answer is. I am glad I seem to somehow get whatever I need just by eating somewhat healthfully. It is pretty cool we get these things that way. Of course if we didn’t our ancestors wouldn’t have survived to create descendants that finally became us – as they had a much harder time than me (who can just go the restaurant and grocery store and get all sorts of wonderful food).