theory

Has Wheat Changed for the Worse? | Earth Wise

September 11, 2020 By EarthWise Leave a Comment

In recent years, the number of people affected by celiac disease, wheat allergies, or gluten or wheat sensitivity has increased dramatically. Why this should be is not well understood. One theory is that modern wheat varieties contain more immunoreactive protein than those used in the past. Researchers at two German research institutions investigated this issue in detail.

Wheat grains contain about 70% starch. Proteins constitute 10 to 12% of wheat, and nearly 80% of that protein is gluten. Gluten is a compound mixture of two types of protein subgroups: gliadins and glutenins.

The researchers investigated the protein content of 60 preferred wheat varieties in use during the period between 1891 and 2010, making use of an extensive seed archive. They selected 5 leading wheat varieties for each decade over that 120-year period and cultivated the plants under the same geographical and climate conditions.

The results were that the modern wheat varieties actually contain slightly less protein than old ones. Gluten content itself has been essentially constant over the 120 years, although the proportion of gliadins (which are the prime suspect for causing undesired immune responses) was actually 18% lower while the proportion of glutenins was 25% higher.

Overall, they found no evidence that the immunoreactive potential of wheat has changed over the years as a result of the cultivation factors.

The researchers note that some of the other, less significant proteins in wheat have not been investigated with regard to their physiological effects, so there is more work to be done. But so far, the culprit for increasing wheat sensitivity has not been found.

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Is modern wheat off the hook?

Photo, posted July 3, 2009, courtesy of Clare Black via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why The Arctic Is Warming So Fast | Earth Wise

April 7, 2020 By EarthWise Leave a Comment

The Arctic has been warming at the fastest rate of any place on Earth. There have long been observations of amplification of Arctic warming, meaning that its temperature increases have been well above what would be expected from the global temperature rise.

Many climate models have attributed this warming to the melting of sea ice. As the bright white ice disappears for longer periods of the year, the dark surface waters that are exposed absorb sunlight rather than reflecting it back into space the way the ice does. This is known as the ice-albedo feedback. But it does not entirely explain the amount of warming in the Arctic.

Researchers at the Scripps Institution of Oceanography have developed a new theory that helps to explain what is going on.

In the areas of the Arctic Ocean where there is sea ice, the water is actually warmer at depth and colder near the surface. The deeper waters are fed by the relatively warm Pacific and Atlantic Oceans while the surface water is cooled by the ice. The increasing temperature difference between surface and deeper water causes a greater upward flow of heat. This was first observed in research cruises that revealed evidence that the Arctic Ocean water was becoming more turbulent over time.

According to computer modeling, this phenomenon is responsible for about 20% of the amplification of global warming that occurs in the Arctic.

There are multiple ongoing studies looking at the Arctic warming trend. Other factors that have contributed over time are the presence of chlorfluorocarbons in the atmosphere. That contribution is waning since the use of CFCs has been phasing out over time.

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Researchers Find New Reason Why Arctic is Warming So Fast

Photo, posted April 19, 2017, courtesy of Markus Trienke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Science And False Beliefs

January 21, 2019 By EarthWise Leave a Comment

There are sizeable numbers of people who hold to beliefs that run counter to overwhelming contrary evidence. Flat Earthers and Holocaust deniers are well-known examples and, more recently, people – some of them in high places – who reject the evidence for climate change.

New research published in the journal Open Mind by developmental psychologists at UC Berkeley suggest that feedback, rather than hard evidence, boosts people’s sense of certainty when learning new things or trying to tell right from wrong. People’s beliefs are more likely to be reinforced by the positive or negative reactions they are exposed to than by logic, reasoning, and scientific data.

People’s learning habits can limit one’s intellectual horizons. According to the study, if you think you know a lot about something, even though you don’t, you’re less likely to be curious enough to explore the topic further and will fail to learn how little you know.

This phenomenon plays out in social media and cable-news echo chambers and explains how some people are easily duped by charlatans. Receiving positive feedback for what they are saying can make people believe they know more than they actually do. This confidence makes them less likely to seek out and learn more information about the subject, as well as take into account contradicting opinions or facts.

Another factor is that what influences people’s certainty is that their confidence tends to depend on what they heard most recently rather than on long-term cumulative data. A few pieces of recent information tend to get much more attention than an extensive body of data. If a crazy theory is able to make a correct prediction a few times, people tend to get fixed in their belief in that theory and be less open to other information.

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