Archive for the 'General Science' Category

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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24 responses so far

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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32 responses so far

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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39 responses so far

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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19 responses so far

Oct 31 2016

The Times Gets it Wrong on GMOs

Published by under General Science

Bt BringalIt is unfortunate that so many journalists begin with a narrative and then back fill the facts and points necessary to tell their narrative. I have encountered this many times when being interviewed for an article or documentary – more often than not the reporter or producer is simply hunting for quotes to plug into a story they have already written. I am not giving them information so much as filling a role, which could be that of expert or of token skeptic.

We are all familiar with this phenomenon when reading about political topics in outlets that have a clear editorial policy. If the policy is clear, we don’t even expect objectivity. When reading about non-political topics, however, I do think there is a general expectation of objectivity, but the motivated reasoning can be just as pronounced.

A recent New York Times article, in my opinion, is a good example of what happens when a journalist writes about a complex and contentious topic and allows their narrative to overtake the facts. The article, Doubts About the Promised Bounty of Genetically Modified Crops, declares the narrative in the headline (yes, I know journalists don’t write their own headlines, but they still may accurately reflect the tone of the article, as in this case).

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62 responses so far

Oct 14 2016

Science Is Not Colonialism

science-fallismThis Youtube video is making the rounds. Relax, tape a deep breath, and take a look at the video.

The core point that the primary speaker is making is this: Science is nothing but Western colonialism imposed upon the African people (and presumably others). The only solution is for science to “fall” – she would like to wipe away all of science and start with a blank slate, so that Africans can develop their own knowledge.

She gives as an example that Newton saw an apple fall, made up gravity, wrote down some equations, and now that is scientific truth imposed on the world forever (seriously, I am not exaggerating this one bit).

The other pillar of her position is that in Africa there are practitioners of black magic who can summon a lightening bolt at their enemy. This is not explainable by “Western” science, and yet this is African knowledge, and therefore is an example of Western colonialism suppressing indigenous wisdom.

After stating that practitioners can summon lightening, someone in the audience shouted “It’s not true.” While this might be considered rude, it is an understandable impulse. The response of the moderator was illuminating, in my opinion. She stood up, shamed the audience member, lectured him about the fact that he violated their safe space that is supposed to be free of antagonism, and then forced him to apologize.  Continue Reading »

72 responses so far

Oct 13 2016

GMOs and Horizontal Gene Transfer

Published by under General Science

horizontal-gene-transferPeople reject genetically modified organisms as food (GMOs) for a variety of reasons, but the single most cited reason is the false belief that they are unhealthy. That specific belief also represents the single greatest disconnect between the opinion of scientists and of the general public in a 2015 Pew poll, greater than evolution, climate change, or vaccine safety.

The reason for this disconnect is that the public is relying upon their intuition, rather than scientific knowledge, to arrive at their conclusion. Further, that intuition has been hijacked by a deliberate anti-GMO campaign orchestrated by misguided environmentalists and by the organic food lobby to help promote their brand.

As Stefaan Blancke and his coauthors argue in the above article:

This intuitive reasoning includes folk biology, teleological and intentional intuitions and disgust.

One of the primary “folk biology” talking points of the anti-GMO crowd is that it is “unnatural” to place genes from one species into a distant species. No further reasoning is offered to defend this position – just the invocation of what is “natural” seems to be enough. Those who defend the scientific position often point out that this irrelevant, just a manifestation of the appeal to nature fallacy. Whether or not something occurs in nature does not determine if it is good or bad for human health.

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