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Like many insects, beetles can walk upside down without falling due to the extremely sticky structures of their foot pads. Scientists James Bullock and Walter Federle from the University of Cambridge recently published a study in the journal Naturwissenschaften (The Nature of Science) that found different hair structures have different levels of stickiness. Their study is the first to measure the adhesive strength of a single seta, the adhesive hairs that are responsible for the “stickiness” of the beetle’s feet.
The researchers found there were three different structures of setae on the foot pads: pointed, flat (spatula-tipped) and disk-like. The three structures have different functions depending on the specific pattern they are arranged in. Each of these structures is made up of thousands of microscopic hairs and prior to this study there was no way to determine the adhesiveness of one individual hair due simply to their microscopic size.
By using an extremely fine glass cantilever and measuring the deflection of the cantilever with a microscope, the exact force needed to detach each hair was calculated. By use of this novel technique the researchers were able to calculate the exact stickiness of each hair, which are only 5 micrometers across.
Of the three different seta structures the disk like hairs had the greatest level of stickiness, followed by the spatula shaped hairs, with the pointed hairs coming in least sticky. The most sticky hairs were also the most stiff, most likely providing stability to the foot-pad. The researchers hypothesize it is these disk-like hairs that are particularly responsible for the strong adhesion the beetles have to smooth surfaces, such as the underside of a leaf.
This adhesion is also important during mating so that males can attach themselves to a female’s back. The other hair structures which aren’t as sticky are probably used for adhesion while running because they are quicker and easier to unstick.
This new understanding of the beetle’s sticky feet may one day lead to the creation of bio-inspired synthetic adhesives, such as extra sticky super glue.
As populations across the developed world age, policy-makers have become increasingly concerned with methods of controlling the rapid-rise of healthcare costs. Rising levels of insulin resistance, a physiological condition characterized by a decreased ability of the hormone insulin to lower blood sugar levels, and it’s associated maladies of obesity, increased blood lipid levels and diabetes increasingly present one of if not the greatest source of rising healthcare expenditures.
Presently aside from diet and exercise there are few widespread effective treatment for insulin resistance, a situation that has posed a concern for policymakers for quite sometime. However, recent research at the University of Western Ontario in partnership with the Ontario Heart and Stroke Foundation and Pfizer Canada’s Cardiovascular Research Program might just be the first step towards developing one.
The researchers have discovered that a flavonoid chemical, found in tangerines, known as Nobilitin when fed orally to genetically-engineered mice appeared to have helped them stave off the development of insulin resistance, as compared to a control group not given Nobilitin, when fed a high-fat/high-sugar diet.
After eating, a spike in blood-sugar levels leads to the secretion of insulin, a hormone used to control carbohydrate and fat metabolism in the body, specifically insulin slows down the use of stored fat-cells as an energy source and the body switches to glucose. In a healthy individual this process is self-regulating, after the food has been digested, insulin levels will drop and the body will once again resume using stored fat as an energy source. In individuals with pre-diabetes however, the insulin receptors become phosphorylated during the uptake of insulin rendering them inoperable. The body becomes less-effective at controlling blood-sugars, and levels can rise causing adverse health-effects.
Nobilitin appears to activate the same receptor-response mechanism as insulin without causing phosphorylation. Additionally Nobilitin prevents the release of VLDLs (very low density lipoproteins) an unhealthy fat associated with heart disease. When combined, these two factors appears to of prevented the mice from developing insulin-resistance and staved off the development of diabetes, obesity and coronary disease.
While a significant amount of further investigation remains to be done to determine if the findings are transferable to humans, this research is an exciting development nonetheless, towards a potential cure for insulin resistance and type-II diabetes mellitus.
Mulvihill, E. E., Assini, J. M., Lee, J. K., Allister, E. M., Sutherland, B. G., Koppes, J. B., . . . Huff, M. W. (2011). Nobiletin attenuates VLDL overproduction, dyslipidemia, and atherosclerosis in mice with diet-induced insulin resistance. Diabetes, doi:10.2337/db10-0589
NHS Choices. (2011). Tangerine chemical good for mice. Retrieved 04/06, 2011, from http://www.nhs.uk/news/2011/04April/Pages/tangerines-prevent-diabetes-obesity-claim.aspx
Research by a UBC PhD candidate Erika Eliason was recently covered in a number of news media.
The Chilko sockeye is the Michael Phelps of salmon.
This article is targeted for a more general audience is one of the best write ups I found. There is little jargon and the main results/ story are really clearly presented. It also stays true to the original research. Most of all I love the unique spin the author (Elizabeth Pennisi) put into the story with the Michael Phelps analogy.
The CBC’s coverage of the story is equally true to the research though I found the story they told to be less engaging than the Science news article. The CBC story is actually very similar to the UBC media release.
The CBC also featured the story on their radio show Quirks and Quarks (April 2, 2011).
Eliason was interveiwed for the show and overall did pretty well at sounding interesting and not using jargon. Bob Macdonald (the host) did a good job of getting her to better describe the ‘leads’ she used to measure the heartrate of the fish.
The Globe and Mail also covered the story, their article opened with:
Sockeye salmon in the Fraser River are facing such critically warm water in the summer that populations will either have to adapt or die as climate change pushes temperatures even higher, according to new research at the University of British Columbia.
With oceans, lakes and rivers warming worldwide, the study holds a warning that fish stocks are facing increasingly dire environmental challenges.
The globe and mail definitely presents a different main message than the other media. It seems the writer did not fully understand the results of the research or perhaps went too far trying to generalize the results and make a bigger story out of them.
This is probably an indication of where the reporters got their information, the differences in their stories.
Eliason’s paper is about how some Salmon are better suited to climate change, their hearts allow them to survive in warmer water where other species would have difficulty.
The spheres and colors represent the various species and trophic levels respectively, in Nevada Lakes, USA. (Picture Credits: Harper et al. 2005).
Numbers are numbing and data are messy. “Visualization tools can help untangle complexity,” says Eric Berlow—ecologist at Sierra Nevada Research Institute in California. Good visualizations can bring out the details, organize information, and allow scientists to see data in a different way. A computer model called “Niche Model” emerged in the year 2000. It was developed by researchers of the applied mathematics department at Cornell University, Williams and Martinez. Before the model, many ecologists base their theories on “sharply focused” ecosystems with less species, to avoid “clutters” in their study. However, this was problematic since it risks oversimplifying real-world phenomena.
Since 2000, Niche Model injected a healthy dose of complexity into the field of ecology and conservation biology research. By embracing the complexity, ecologists can now generate more accurate predictions that mimic real ecosystems.