Archive for the 'General Science' Category

Apr 20 2017

Retreat of the Cryosphere

glacier-retreatPatrick Burkhart and his colleagues recently published a review of their research on the cryosphere, which is a collective term for all the ice on the surface of the Earth. In addition to their review of the science, the new information they add is a photographic project documenting the retreat of glaciers around the globe.

The retreat of the cryosphere is one of the many lines of evidence supporting the idea that the earth has been warming over the last half-century. There are several different ways to look at this. You can look at each pole to see the extent of ice coverage at their peak in winter and minimum in summer. You can look at specific ice sheets, like Greenland. You can look at glaciers. And you can look at total global ice, the cryosphere, which of course is the best single measure.

With regard to glaciers, the authors point out that there are many variables affecting the current size of any individual glacier. It is possible but difficult to account for all these variables and isolate one as a primary cause of melting. However, you can survey glaciers from around the world, which is a good way to control for local variables. When we do this we find there is a significant trend toward glacial retreat.

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Mar 20 2017

The Need for Publicly Funded Science

Trump-ScienceThe American scientific community is in a bit of a panic over Trump’s first proposed budget. The budget calls for an 18% decrease ($5.8 billion) for the National Institutes of Health (NIH). There are deep cuts in energy research and Earth science as well.

The reaction of the scientific community has been consistent – such cuts would be disastrous.

It probably comes as no surprise that science is expensive. This is despite the fact that scientists are generally paid very little, especially when compared to their years of training. Science is a career of passion. But maintaining a lab or conductive field research can be very expensive. Research often requires expensive equipment and materials, lab space, support staff, and lots of time.

Research is not just something that scientists do – it requires extensive infrastructure. That infrastructure needs to be maintained mostly with one-off grants. The vast majority of scientific research will not directly generate profits for the researchers, the lab, or the supporting institution. Keeping a lab going is like keeping plates spinning, the researchers are constantly applying for grants and weaving together the funding they need.

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Mar 16 2017

Does Glyphosate Cause Cancer?

Published by under General Science

glyphosate-effects-fbGlyphosate, the active ingredient in Roundup, is the most popular herbicide used in the world. It has gained particular attention because several of the more commonly used GMOs are glyphosate tolerant, and therefore are intended to be used with the herbicide. Glyphosate is also manufactured by Monsanto (although it is off patent and there are generic versions available).

The question of the safety of glyphosate is in the news again after the New York Times did an article about a recent court case against Monsanto and the documents revealed through discovery and made public by the judge. Unfortunately, in my opinion the NYTs article is poorly done, and reveals significant bias – anti biotech bias is nothing new for the NYTs or the author of this article, Danny Hakim.

Last year I wrote about another article that Hakim wrote in the NYTs about GMOs, concluding:

In my opinion Hakim’s article in the Times was a hack piece with a biased narrative that is nothing more than a rehash of tired anti-GMO tropes that have already been widely deconstructed. He is entering this conversation late, and isn’t up to speed.

There are essentially two questions raised by Hakim’s latest article. The first concerns the behavior of Monsanto. Hakim alleges that they ghostwrote scientific articles for academics and used political pressure to shut down EPA reviews of glyphosate’s safety. I would not assume this assessment is true, and certainly don’t trust Hakim’s journalism given his history. The academics in question deny the allegations, and Monsanto claims these e-mails are taken out of context. We have certainly seen that before.

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Mar 14 2017

GM Corn To Prevent Deadly Toxin

aflatoxin-cornAflatoxin is a serious food contaminant that causes both acute and chronic illness in animals and humans. It was first discovered in 1960 when 100,000 turkeys in the UK died over the course of a few months. Their deaths were tracked to a nut-based feed that was contaminated with a newly discovered toxin, named aflatoxin.

Aflatoxin is a group of 20 toxins produced by a fungus, Aspergillus species. According to Food Safety Watch:

Aflatoxins may be present in a wide range of food commodities, particularly cereals, oilseeds, spices and tree nuts. Maize, groundnuts (peanuts), pistachios, brazils, chillies, black pepper, dried fruit and figs are all known to be high risk foods for aflatoxin contamination, but the toxins have also been detected in many other commodities. Milk, cheese and other dairy products are at risk of contamination by aflatoxin M. The highest levels are usually found in commodities from warmer regions of the world where there is a great deal of climatic variation.

Corn is perhaps the biggest source of aflatoxin contamination. It is estimated that 16 million tons of corn are disposed of each year due to aflatoxin contamination. The toxin is highly stable and can survive most types of food processing.

Acute toxicity can result in death when severe. Chronic toxicity is difficult to detect, and the most common effect is liver damage and increased risk for liver cancer.

Many techniques are used to minimize contamination, but even with these methods aflatoxin is a huge source of food waste and an important cause of human illness, especially in developing countries. Continue Reading »

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Mar 02 2017

Tucker Carlson vs Bill Nye on Climate Change

Published by under General Science

Nye vs CarlsonTucker Carlson of Fox News recently had Bill Nye on as a guest to discuss climate change. The entire interview is worth a listen because it nicely illustrates the strategies employed by denialists.

Here are some highlights:

Carlson pushes what is a very common denialist narrative, that they are skeptics who are just asking honest questions. Meanwhile the proponents of global warming are trying to shout them down, call them names, and are doing a disservice to science by trying to shut down debate.

The problem with this narrative (other than not being true) is that you can apply it to any position that denies established science. Flat-Earthers are just skeptics, stop shouting them down. Answer their honest questions.

The devil, of course, is in the details. Are climate change denier just asking honest questions? Ironically, Carlson himself demonstrates in the interview that he isn’t. He is playing rhetorical games to cast doubt on climate science.

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74 responses so far

Feb 28 2017

De-Extinction

Published by under General Science

Recently Harvard University geneticist Prof George Church announced that he and his team are close to making a mammoth-elephant hybrid. They have been reconstructing mammoth DNA from frozen remains.

They will not be able to make a 100% mammoth clone, but rather they are splicing mammoth genes into Indian elephant DNA and hope to grow a hybrid. The result would have, they hope, enough mammoth traits to be adapted to a colder environment, and therefore essentially spread the range of the Indian elephant north.

Such programs raise two question – can we actually achieve de-extinction with such techniques, and should we?

The answer to the first question is – we’re not even close yet. The reporting of Church’s announcement was highly sensationalized, with many outlets reporting that we will have mammoths in two year. The reality is that Church’s team has made 45 mammoth DNA inserts into the Indian elephant genome. This is insignificant.

Estimates of the differences between mammoth and elephant DNA indicate that several thousand genes are involved. In addition, there may be even more regulatory changes in the DNA outside of genes. You can make a lot of evolutionary change by turning on or off, or up or down, the expression of genes without changing the genes themselves.

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Feb 14 2017

Science – We Have a Reproducibility Problem

Published by under General Science

reproducibility-smallJohn Ioannidis has published an interesting commentary in JAMA about the current reproducibility crisis in basic and clinical scientific research. Ioannidis has built his career on examining the medical literature for overall patterns of quality. He is perhaps most famous for his study showing why most published research findings are wrong.

The goal here is to improve the science of science itself (or “metascience,” like “metacognition”). As science has progressed a few things have happened. The questions are getting deeper, more complex, and more subtle. Research methods have to be more rigorous in order to deal with these more subtle questions.

The institutions of science have also grown. Science is big business, which means that there are “market forces” which push institutions, scientists, and publishers into pathways of least resistance and maximal return. These pathways may not be optimal for quality research, however.

The stakes are also getting higher. We now have professions and regulatory schemes that are supposed to be science-based. If we take medical products, for example, the public is best served is products are safe and effective and truthful in the claims made for them. We need scientific research to tell us this, and we need to know where to set the bar. How much scientific evidence is enough? We can only answer this critical question if we know how reliable different kinds of scientific evidence are.

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Feb 13 2017

Immigration and Crime

Prevalence-of-CrimeDoes legal or illegal immigration increase crime? That is an empirical question that should be answerable through rigorous research. Whatever the answer, it should inform our policy priorities and decisions. At the very least, if we are going to have a national conversation about immigration, the established facts should serve as common ground.

When you are done laughing (or crying) you might be interested to read about recent research into the correlation between patterns of immigration and various types of personal and property crime. Researchers have previously looked at this question by focusing on individuals – are immigrants more or less likely to commit crimes than native born Americans? Let’s consider that question first.

The research overwhelmingly shows that first generation immigrants, whether legal or illegal, are less likely to commit all types of crime at all ages than the native born. Interestingly, by second generation the statistics look more like native born crime rates, so it does not take long to assimilate in this regard. As an aside, this, of course, does not include crossing the boarder illegally itself, but it has been pointed out that being an undocumented immigrant is not a criminal offense, but a civil offence.

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142 responses so far

Feb 07 2017

New GM Wheat Trials Set

Published by under General Science

Wheat-field-against-blue-sky-1200x600Right now there are no genetically modified (GM) cultivars of wheat that are approved and on the market, so essentially there is no GM wheat. Wheat is an important staple crop responsible for about 21% of total calories consumed by humans in the world. Improving net yields of wheat could therefore have important impacts on our food production.

GM Wheat

Over the last century agricultural experts have used conventional breeding, including hybrids, to increase yields of major crops. Apparently conventional breeding is running up against diminishing returns, and some believe we are at or approaching the limit of wheat yield with conventional techniques.

However, improving the efficiency of photosynthesis, the process by which plants turn sunlight into biomass, is an unexploited strategy. Researchers are now applying for field trials of a GM variety of wheat that incorporates genes from  a closely related grass, the stiff brome.

Professor Christine Raines, Head of the School of Biological Sciences at the University of Essex and principal investigator for this research project, described the current modification:

 “In this project we have genetically modified wheat plants to increase the efficiency of the conversion of energy from sunlight into biomass. We have shown that these plants carry out photosynthesis more efficiently in glasshouse conditions. One of the steps in photosynthesis shown to limit this process is carried out by the enzyme. sedoheptulose-1,7-biphosphatase (SBPase). We have engineered GM wheat plants to produce increased levels of SBPase by introducing an SPBase gene from Brachypodium distachyon (common name stiff brome), a plant species related to wheat and used as a model in laboratory experiments.”

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Jan 27 2017

Scientists Create Metallic Hydrogen

jupiter-magnetic-fieldIt was just announced that for the first time scientists were able to create a small amount of metallic hydrogen in the lab. This is a significant breakthrough, and is sure to lead to further discovery, although it remains to be seen what specific practical applications may emerge.

Hydrogen, as most people know, is a gas at familiar temperatures and pressures. The universe is comprised of about 90% hydrogen. There is very little free hydrogen on the Earth, since it is a very light gas, but there is lots of hydrogen bound up in molecules, such as water.

In 1935, physicists Eugene Wigner and Hillard Bell Huntington hypothesized that under extreme pressure hydrogen atoms may form into a metal – metallic hydrogen. The point at which this happens was named the Wigner-Huntington transition, which explains the title of the recent paper. Metallic hydrogen can further be a liquid, in which the electrons and protons are free flowing, or they can form a crystalline structure and be a solid.

Astronomers infer that the core of Jupiter may be hot liquid hydrogen. We know that Jupiter is made mostly of hydrogen, and we can calculate that the pressure deep in Jupiter’s core must have millions of times the pressure on the surface of the Earth. That is sufficient pressure, according to theory, to compress hydrogen into its metallic form.

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