Author Archives: curiouscat

Webcast: Examining the Scientific Basis Around Exercise and Diet Claims

Tim Noakes is the Director of UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Science, University of Cape Town and Professor, Discovery Health Chair of Exercise and Sports Science, University of Cape Town.

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 He also discusses the outdated ideas related to lactic acid and muscles.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.”

As I have said before, scientific literacy is critical to allow us to make those judgements about what is credible evidence and what are outright lies, foolish claims or highly suspicious claims tainted by conflicts of interest.

Related: Can You Effectively Burn Calories by Drinking Cold Water? – Static Stretching Decreases Muscle Strength – Lack of Physical Activity Leads to 5.3 Million Early Deaths a Year – Science Continues to Explore Causes of Weight Gain – Study Finds Obesity as Teen as Deadly as Smoking

Clay Water Filters for Ghana

Pure Home Water, Ghana manufactures and distributes AfriClay Filters in an effort to bring clean water to 1 million people. So far they have delivered filters to provide 100,000 people clean water.

The process is simple. Water is placed in a clay filter and gravity pulls the water through the pores left in the clay during firing.

Sediment and bacteria are filtered out in several ways:

  • Physical straining: the particles are too large to fit through the pores in the clay
  • Sedimentation or adsorption: particles come to rest on or stick to the clay
  • Inertia: friction in the pores keeps the particles from passing through

Bacteria are also killed by a coating of colloidal silver (a disinfectant), which we apply to all filters that pass our quality control tests. While sediment and bacteria are filtered out, the molecules of water are small enough to pass through the pores in the clay.

The filters are sold to those who will use them. The effort has shown a willingness to pay by villagers in remote Northern Ghana (those earning < US$1/day). I imagine (I am just guessing) the prices are subsidized; in the last decade more (most?) appropriate technology solutions will have those benefiting pay something for the benefits they receive. My nephews are working on a similar effort in India, using bio sand filters, I plan to post more on that later. There is current a campaign to help fund the delivery of water filters to Indian villages.

Related: Solar Powered Water Jug to Purify Drinking Water – Electric Wind – Student Invents Solar-Powered Fridge – Reducing Poverty

Europe Bans Certain Pesticides, USA Just Keeps Looking, Bees Keep Dying

For years the bee colony collapse disorder has been showing the difficulty of the scientific inquiry process. And that difficulty often becomes more difficult if interests with lots of money at stake want to block certain conclusions.

One-Third of U.S. Honeybee Colonies Died Last Winter, Threatening Food Supply

Multiple factors — pesticides, fungicides, parasites, viruses and malnutrition — are believed to cause the losses, which were officially announced today by a consortium of academic researchers, beekeepers and Department of Agriculture scientists.

“We’re getting closer and closer to the point where we don’t have enough bees in this country to meet pollination demands,” said entomologist Dennis vanEngelstorp of the University of Maryland, who led the survey documenting the declines.

Beekeepers lost 31 percent of their colonies in late 2012 and early 2013, roughly double what’s considered acceptable attrition through natural causes. The losses are in keeping with rates documented since 2006, when beekeeper concerns prompted the first nationwide survey of honeybee health. Hopes raised by drop in rates of loss to 22 percent in 2011-2012 were wiped out by the new numbers.
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Most losses reported in the latest survey, however, don’t actually fit the CCD profile. And though CCD is largely undocumented in western Europe, honeybee losses there have also been dramatic. In fact, CCD seems to be declining, even as total losses mount. The honeybees are simply dying.

“Even if CCD went away, we’d still have tremendous losses,” said entomologist Diana Cox-Foster at Pennsylvania State University. “CCD losses are like the straw that breaks the camel’s back. The system has many other issues.”

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Given Tablets but No Teachers, Kids Teach Themselves – Having Never Seen Advanced Technology Before

In a repetition of an experiment I have posted about here on the Curious Cat Science and Engineering Blog before (Letting Children Learn – Hole in the Wall Computers): Given Tablets but No Teachers, Ethiopian Children Teach Themselves

The experiment is being done in two isolated rural villages with about 20 first-grade-aged children each, about 50 miles from Addis Ababa. One village is called Wonchi, on the rim of a volcanic crater at 11,000 feet; the other is called Wolonchete, in the Great Rift Valley. Children there had never previously seen printed materials, road signs, or even packaging that had words on them, Negroponte said.

Earlier this year, OLPC workers dropped off closed boxes containing the tablets, taped shut, with no instruction. “I thought the kids would play with the boxes. Within four minutes, one kid not only opened the box, found the on-off switch … powered it up. Within five days, they were using 47 apps per child, per day. Within two weeks, they were singing ABC songs in the village, and within five months, they had hacked Android,” Negroponte said. “Some idiot in our organization or in the Media Lab had disabled the camera, and they figured out the camera, and had hacked Android.”

Nicholas Negroponte has tendency to overstate the fact from what I remember. I don’t think what he claims as “hacking Android” here is what a real scientist would claim as than is a write up of the results of the experiment. He could well mean they updated a setting or some similar thing. It is a shame to mislead when the bare facts are so cool. And possibly he isn’t misleading – I just am worried he is.

Also what does 47 apps per day mean? I can’t understand how you can usefully (including entertainment do that in any sensible way) – I doubt I use 15 applications in a month and I use the computer hours every single day. Makes me worry that “using” is not a very enlightening piece of data – instead just trying to make it seem like using 47 must mean they are engaged; it seems more likely to me to mean they are not used successfully so they have to go try something else or they are counting “used” in ways we wouldn’t.

Once a week, a technician visits the villages and swaps out memory cards so that researchers can study how the machines were actually used.

These kinds of experiments are very cool. They show how intrinsically curious we are are. Sadly our schools often beat the curiosity out of kids instead of engaging it.

Related: What Kids can Learn (look at the same idea in 2006) – Providing Computer to Remote Students in Nepal (2009) – $100 Laptops for the World

The Wonderful Coconut

One of the treats of living in a tropical climate is drinking coconut water. I love drinking the water from fresh coconuts. This video provides insight into the many uses of all parts of the coconut tree.

The Truth About Coconut Water by Kathleen M. Zelman, MPH, RD, LD – WebMD

[coconut water] has fewer calories, less sodium, and more potassium than a sports drink. Ounce per ounce, most unflavored coconut water contains 5.45 calories, 1.3 grams sugar, 61 milligrams (mg) of potassium, and 5.45 mg of sodium compared to Gatorade, which has 6.25 calories, 1.75 grams of sugar, 3.75 mg of potassium, and 13.75 mg of sodium.
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There are some health benefits to consuming coconut water. It’s an all-natural way to hydrate, reduce sodium, and add potassium to diets. Most Americans don’t get enough potassium in their diets because they don’t eat enough fruits, vegetables, or dairy, so coconut water can help fill in the nutritional gaps.

Beyond that, the scientific literature does not support the hype that it will help with a laundry list of diseases. “There is a lot of hype about coconut water, yet the research is just not there to support many of the claims and much more research is needed,” says Cheung.

I have tried bottled coconut water which was pitiful. I don’t know if that was just a bad type and good options exist or the fresh stuff is just much much better. But I’ll stick to fresh coconut water as long as I can.

Related: Does Diet Soda Result in Weight Gain? – Can You Effectively Burn Calories by Drinking Cold Water? – How do Plants Grow Into the Sunlight? – Eat food. Not too much. Mostly plants.

Pew Science and Technology Knowledge Quiz

The Pew Science and Technology Knowledge Quiz is a simple 13 question quiz to get a very simple look at scientific understanding in society. Obviously these types of quizes are just extremely simple views, still it is interesting to see how you can do and what questions people struggle with.

graphic showing 13 of 13 answers correct

graph showing distribution of correct answers by those taking the quiz

I am surprised the fewer than 50% of the people got 2 true or false questions correct, including “Electrons are smaller than atoms. Is this statement…” Looking back at my previous post, I guess I shouldn’t be surprised, in the 2009 Pew Science Knowledge Quiz it is also the case that under 50% got the are electrons smaller than atoms question right.

They also provided a breakdown by demographic factors. Men had better percentages of correct answers, for the 2 true or false questions men were correct 55% of the time while women got 40% correct. The two other true of false questions had much higher correct answer rates 77% (83% for men 72% for women) and 66% (70 for men, 63 for women).

There was also a substantial tendency for the youngest ages to do better and the performance to decline for each age group. I am not surprised by the question answered incorrectly most often (only 20% got it right), see if you can guess which it is.

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Engineers Save a Life

photo of car resting in river

This photo was taken by the driver’s parents when they arrived. It doesn’t show much of what it went through to get there, but it gets most of the point across. The picture was taken 200 feet away and looking down from the road.

I got into a major accident today that I was able to somehow walk away from. I lost control of my car and went off of a cliff into boulders, and after flipping a few times, settled in the river. I walked away with cuts on my hands from the broken glass and a bruise that runs from my chest over my left shoulder where my seat belt held me in place.

I shouldn’t be alive discussion on Reddit.

swapsrox: Time to send a letter to the manufacturer thanking them for their safety design! I guarantee your letter will be put on an engineer’s wall, and they’ll know there is a reason they go to work every day.

cmdshftn: Great engineering saved your life. The vehicle’s safety systems from the seatbelt to the crumple zones to the design of the seat kept you safe and alive despite all hell going on around you. Please write a letter to the manufacturer thanking their design team, but above all, follow up with whoever you need to in that jurisdiction to find out why there isn’t a guard rail on that road! Vehicle safety helps, but great road design to prevent an accident like yours helps more!

Related: Electronic Stability Control Could Prevent 33% of Crash Deaths – Driver Thanks Engineer Who Hit Him on Purpose – Smokeless Stove Saves Lives – Toyota Scion iQ: 37 MPG – Engineer Tried to Save His Sister and Invented a Breakthrough Medical Device

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Can You Effectively Burn Calories by Drinking Cold Water?

Neil deGrasse Tyson stated on Twitter:

Wanna lose 1200 Calories a month? Drink a liter of ice water a day. You burn the energy just raising the water to body temp.

What if your body is trying to cool down? I would imagine we have to use energy to cool off (though I am no expert on this)? So if you drink cold water and your body has less need to cool off, couldn’t this actually end up “saving” your body needing to burn calories – and thus cause yourself to gain weight?

This model would be similar to a server room that was cooled with air conditioning and cold winter air to cool off the servers. If there was less cold air used then more electricity would be used running the air conditioner to cool down the servers. I don’t know if it is a decent analogy though – maybe that isn’t an usable model for how we cool off.

I know we cool off partially by pushing water out onto the exterior of our skin to have it evaporate and cool us off. I would think that takes energy to do.

I do get that it takes energy to raise the temperature of the water you consume. It does make sense to me that if you were cold (like say I was during the winter living in the house I grew up in) you would use energy raising the temperature of the water.

What the overall energy situation is if your body needs to cool down seems questionable to me. Please let me know your thoughts. In any event his statement is accurate. It is just that the implication may lead people astray; that you can consume 1,200 Calories extra to balance the 1,200 Calories drinking cold water uses (or loss weight by having reduced your excess Calories by 1,200 if you eat exactly the same things you would without the cold water).

Related: Why is it Colder at Higher Elevations? – Does Diet Soda Result in Weight Gain? – Why Does Hair Turn Grey as We Age? – How Corn Syrup Might Be Making Us Fat – Why Wasn’t the Earth Covered in Ice 4 Billion Years Ago (When the Sun was Dimmer)

Building A Better Bed Bug Trap Using Bean Leaves

Building A Better Bed Bug Trap

An old folk remedy involving hairy bean leaves strewn around the bedroom may have a new life as a modern bed bug trap, according to new research from the University of California, Irvine and the University of Kentucky.
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Although its mechanisms weren’t known at the time, the tactic dates back to at least 1678, when the English philosopher John Locke wrote of placing kidney bean leaves under the pillow or around the bed to keep bed bugs from biting as he traveled through Europe.

In the early twentieth century, the approach was also common throughout the Balkans, according to a 1927 report from the Imperial and Royal Austro-Hungarian Army. That report suggested the leaves stunned the bloodsucking bugs as they traveled from hiding places to their sleeping hosts during the night; in the morning, the bug-covered leaves were removed and burned.
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“The inconvenience of bean leaves is that not everyone wants them scattered around their bed room.” Synthetics mimicking the surface of the bean leaf, however, could be placed “as a ring around the bed legs, a floor mat at the door, a strip on the bed board, it could be something one put’s in one’s suitcase,”

Very cool. The chemical assault on bed buds is failing all over the world. A new vector to assist in the fight against bed bugs will be most welcome. It is interesting to learn the scientific reasons that explain why some folk remedies work.

Related: Bed Bugs, Science and the Media – Antibiotics Breed Superbugs Faster Than Expected – Pigs Instead of Pesticides