Jeff Danner

Wheat Belly?

The appeal of fad diets is easy to understand. It is increasingly clear that something has gone horribly awry with our health in the United States.   Obesity is on the rise and everywhere we look people are beset with diseases related to gastrointestinal system such as diabetes, irritable bowel syndrome, and an ever-increasing array of food allergies. In the face of these problems, it’s tempting to look for a silver bullet solution to them all. So, we cut carbs or meats or fats from our diets. We consider whether genetically modified foods are to blame and we worry about high-fructose corn syrup. Over the last couple of years, the villain of choice has been gluten, a protein contained in wheat, barley, and rye. As a result, millions of Americans have gone gluten free. Let’s explore whether we have finally found the silver bullet by starting with a simplified model of the gastrointestinal system. The primary jobs of your teeth and stomach are to grind up the food you eat into small pieces. These small pieces head to your small intestine where they are broken down further through the action of specialized proteins called enzymes. As it the case for all proteins, the enzymes that you make are determined by which genes you have. We will return to that point later. Specific types of enzymes break down specific types of...

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Can We Start Protecting Jordan Lake Now?

One of my motivations for writing this column is my hope that, at least in some small way, I am helping to inject more science into public policy decisions. Maintaining this hope can be especially challenging at times. The “experiment” to clean up Jordan Lake with larger mixers known as Solar Bees presents one of those challenges. Allow me to walk you through my frustration on this ill-fated and poorly-reasoned project. As local readers will likely know, Jordan Lake provides drinking water for over 300,000 people including the city of Raleigh. In addition, it provides fishing, boating, and swimming opportunities for thousands of people and a place to live for fish, birds, and a variety of other wildlife. For many years now, Jordan Lake has been consistently failing water quality standards for chlorophyll. Before discussing options to address this problem, let’s review how a lake comes to fail chlorophyll standards and why that is a problem. Chlorophyll is the molecule that makes plants green and that captures sunlight for photosynthesis. Chlorophyll in lake water comes primarily from algae, so a lake with too much chlorophyll has too much algae, a situation often referred to as an algae bloom. Algae blooms occur when a body of water accumulates high levels of nitrogen and phosphorous containing nutrients. These nutrients enter the watershed from run-off of fertilizers, primarily from residential and commercial...

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Wood Pellets, Bane or Boon for NC?: Part II

Last week in Part I of this series, I discussed the science of wood pellets and the drivers behind the dramatic increase in their production in the southeast United States. The majority of these wood pellets are being shipped to Europe, particularly, the United Kingdom where they are supplanting coal as a fuel source for electricity production. (This situation strikes me as particularly ironic, but in order to not throw of the thread of our discussion, I have included my observations on this as an endnote.) The wood pellet boom is having a noteworthy impact on North Carolina. Our forests are being harvested for the pellets, several existing and planned wood pellet production facilities are located in the Tar Heel State, and much of their production heads to Europe through the Port of Wilmington. So is this trend a boon or a bane to North Carolina? The topics we need to consider before answering this question are listed below. What are the greenhouse gas emissions impacts of wood pellets? What parts of the tree are being used to make the pellets? What is the impact on NC forests? What is the economic impact on the state of NC as well as the communities where logging and pellet production occur? In order to attempt to answer these questions, I have drawn from the website of the U.S. Industrial Pellet Association...

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Wood Pellets, Bane or Boon for NC?: Part I

Readers of this column may recall that I own 16 acres of property about 2 miles west of Carrboro that I operate as a hobby farm/pollinator reserve. Approximately 14 of these acres are wooded. Prior to 1992, this land was part of a 50-acre farm. There are stands of pine trees that have grown on the level areas that had been farmed prior to 1992, and there are mixed hardwoods on the sections that were too steep to have been used for crops. For the past several years I have received a steady stream of solicitations from timber companies asking if I would like for them to come harvest the trees. I have no interest in this, but let me try to explain why they do. It has a lot to do with wood pellets. Wood pellets are made by pressing sawdust into little cylinders that are approximately one inch long and a quarter inch in diameter. Pressing the pellets into these cylinders creates friction that heats the wood to a high temperature. The high temperature provides two advantages; it helps to dry the pellets, which improves their quality as a fuel source, and it causes the lignin within the wood to melt into a liquid, which then glues the pellets together as they are cooled. The timber industry has been making wood pellets for decades, as a way...

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Sunscreen, A New Threat to Coral?

If you try to stay up to date on science news, you may have notice a number of recent stories about coral reefs being damaged by sunscreen. After seeing several headlines to this effect, I decided to investigate. My initial assumption was that the likely proposed mechanism for this problem would be that dissolved sunscreen in the oceans was preventing sunlight from reaching the coral. It turns out that I was wrong. Before discussing the potential ill effects of sunscreen on coral, let’s review some key features of coral itself. Coral are small invertebrates, similar to clams or oysters, which secrete calcium carbonate exoskeletons. Unlike clams or oysters, coral join their exoskeletons together to form the large monolith that we call a reef. Most species of coral don’t actually “eat” but rather get their energy from a symbiotic relationship with a type of algae known as zooxanthellae. The algae generate sugars via photosynthesis and share some of this bounty with the coral. In exchange, the coral provides place for the algae to latch on and await the sunlight. When sunlight is limited due to polluted water, the algae suffer so the coral suffer. A healthy coral reef will look greenish-brown due to the algae and a dead coral reef will be bright white, the color of algae-free calcium carbonate. The reproductive habits of coral are fascinating. (There is a...

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Improving our Local Food Web: Part II

In Part I of this series, I noted that our local farmers, farmers markets, and restaurants in Orange County constitute a vibrant local food web that provides us with a number of important benefits including nutritious foods and a reduced environmental footprint. Nevertheless, we should always be looking for further improvements. My recommendations for an improved local food web draw heavily from the book Cooked: A Natural History of Transformation by Michael Pollan. Last week, I recommend that we develop the necessary network to allow for making bread from freshly-ground local wheat and that we ferment for vegetables from our local farms for both the nutritional benefits and the energy efficiency that fermentation enjoys over refrigeration/freezing for long-term storage.   I have two more recommendations this week and will conclude with my thoughts on how I would like to contribute to making these recommendations become reality. Beer We have an increasing number of local craft brewers, which is a positive development, but nearly all of their ingredients need to be shipped here from far away. Beer is made from barely, hops, water, and yeast. Most of the barely and hops used for beer production in the United States are grown in the northwest. The species of hops grown there are not well suited to our climate and soil and when grown in North Carolina tend to suffer from downy mildew...

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Improving our Local Food Web: Part I

In Orange County, North Carolina we take well-deserved pride in our local food web. We have innovative local farmers, numerous farmers markets and a host of local restaurants committed to using fresh, local ingredients. But we can, and should, keep striving for improvements. My recommendations for how we might do so, as you might expect, rely on a scientific perspective. To keep to my be-able-to-read-Common-Science-during-one-cup-of-coffee rule, I’ve broken the story into two parts. This week I will review the science and the first half of my recommendations. Next week I will finish my recommendations and conclude with a little dream of mine on how to help my recommendations comes to life. Although I will be drawing on a number of sources for this analysis, I should note that I will be relying heavily on Cooked: A Natural History of Transformation, by Michael Pollan. So, let me start with an extremely short summary of this excellent book. Cooked begins with an explanation of the key shortcoming of a raw food diet. If you limited you diet to just raw fruits, vegetables, and nuts you would expend a lot of time and energy chewing. Further, due to the large size and complex structure of many of the molecules in raw foods, your digestion process would not be able to access all of the nutrients contained within. Cooking, which Pollan defines as...

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Scientific American May 1987

When you are an engineer and the author of a weekly science column, it influences the gifts that you receive. This year for Father’s Day, my family gave me a copy of Scientific American® from May of 1987. What caught their eye was the cover story, Predicting the Earth’s Climate.  They knew I had often written about climate change and figured, correctly, that a comparison between what I had been writing recently and what Scientific American® had to say in 1987 would intrigue me. In addition to the climate story, there were a number of other topics covered in the magazine that seem worthy of a “then” versus “now” analysis. Before addressing the scientific issues, let’s have a walk down the 1987 memory lane to get oriented. In 1987, a gallon of gasoline cost 89 cents a gallon and a postage stamp was 24 cents. The Food and Drug Administration approved AZT as a treatment for HIV and Prozac to lessen our collective anxiety. The world watched the dramatic 58 hour rescue of baby Jessica McClure who fell down a well in Midland, TX and the stock market reminded us of the cycle of boom and bust with a 22% drop in value on October the 19th. Global population hit the five billion mark in 1987. Today there are more than seven billion of us! Scientific American® has always...

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Frozen Shoulder

In the summer of 2010, when I was 44 years old, I was clearing some brush and experienced a sharp and unfamiliar pain in my right shoulder. I have always been quite active, so I am accustomed to a wide variety of aches and pains and consider myself to have a high-degree of pain tolerance. This pain was unusual and too painful to push through. So I put away my tools and headed to the couch. At this point I made a poor decision, one I hope to help you to avoid. I assumed that after several days of rest, my shoulder would feel better. As days, then weeks, and then months passed, the situation deteriorated. Making certain motions with my arm caused severe pain. Furthermore, I was starting to experience the ill effects of sleep deprivation since rolling the wrong way in bed would wake me up several times a night. I was starting to get depressed thinking that this was a sign of age and perhaps would not get better. Finally, in January of 2011, a full six months later, I went to the doctor. I was diagnosed with a condition that I had never heard of before, frozen shoulder, also known as adhesive capsulitis. The shoulder is a ball and socket style joint. Its movements are lubricated with synovial fluid that is contained within a capsule...

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Cold Fusion Part III: Conclusion and Implications

This is the conclusion of a three-part series on cold fusion. Part I covered the science and Part II discussed the history of efforts to entice atomic nuclei to fuse a low temperature, a potential pathway to nearly limitless and clean energy. I would be pleased if you followed the links and started at the beginning of the series. However, if you don’t have the time or inclination, below is the nickel summary of Parts I and II. Fusion of smaller nuclei into larger ones is what powers both stars and hydrogen bombs. Since they contain positively-charged protons, repulsive forces make it extremely difficult to bring nuclei into close proximity. The repulsive force between nuclei is called the coulombic barrier.   If you are somehow able overcome the coulombic barrier and bring them close enough together, then an attractive force between the nuclei kicks in and they will fuse. The current laws of physics tell you that it is necessary to heat nuclei to millions of degrees to overcome this barrier with one rather fascinating caveat.  A phenomenon known as quantum tunneling can allow a nucleus, especially a small one such as a hydrogen nucleus, to “cheat” a bit and surmount the coulombic barrier even while having an insufficient, but still a rather high, level of energy. Despite the fact that the laws of physics say that it is impossible,...

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