If you were born in the 1960′s and if you happen to do The Twist with your partner your heart would of course be racing! Thanks to G protein-coupled inwardly-rectifying potassium channels (GIRKs) your heart can beat back to normal levels. Ironically, the protein does a “twist” to slow down the heart. Go Figure!
GIRK is basically a potassium ion-transporter and found in cardiac cells. It regulates the membrane voltage after the GPCR activated G-beta and G-gamma bind to the transporter.
In this groundbreaking work, three structures were used to understand the dynamics of the transporter.... Read more »
Whorton, M., & MacKinnon, R. (2013) X-ray structure of the mammalian GIRK2–βγ G-protein complex. Nature. DOI: 10.1038/nature12241
I'm proud of my quite 'unusual' area of autism research interest focused primarily on whether diet might, in some way, shape or form, be linked to or impact on some cases of the autisms. It's not been a particularly popular area of research down the years it has to be said. Most of which I've put down to its links to areas far outside of the behavioural dyad (as its known these days). That and all the gastrointestinal (GI) baggage inevitably associated with diets like the gluten- and casein-free (GFCF) diet: leaky gut, gut bacteria, etc. which have been allied with other 'factors' leading to a sort of scientific death-by-association in some quarters.Penfold @Wikipedia Outside of the considerable politics, there is an evidence base to diet and autism. It's not a particularly strong scientific base it has to be said, but there are a few randomised controlled trials (RCTs) to be found, and in agreement with Tim Buie's latest take on gluten-free dietary intervention and autism* "There may be a subgroup of patients who might benefit from a gluten-free diet". Though we still don't know who.Dr Buie, by the way, has also talked about things like lactose (the sugar in milk) intolerance and gut dysbiosis in cases of autism extending the potential of a dietary link. Assuming you adhere to the notion of the autisms - with all their heterogeneity and comorbidity - you might be inclined to also think that autism might not just be a condition of the grey-pink matter floating in the skull. Or maybe not....Hopefully not being too 'me, me, me', I'm actually involved in writing a book about the area of diet and autism as we speak. It's been an interesting journey and allowed me to dig deep into the available science behind diet including some gems such as per this paper**. Outside of just GFCF diets, a variety of other food changes have also been on the research menu with autism in mind, including the ketogenic diet.I've talked about the ketogenic diet before - what it is and how it is starting to enter mainstream medicine when it comes to managing certain types of epilepsy. Briefly, it's all about high fat (no, not that Hai Fat) and low carbohydrates and putting the body into a state known as ketosis. Indeed how this state seems to affect seizure patterns for some people. Yes, I know a similar sort of diet, sorry nutritional approach, has also been suggested as a weight loss measure but I'm not really that interested in that sort of thing on this blog.With autism in mind and outside of any seizure-linked effect, there has been a suggestion, a small suggestion, that a ketogenic diet might also be able to affect certain behaviours linked to autism too as per the paper by Evangeliou and colleagues***. In a more case-study fashion, I'll also draw your attention to my fairly recent discussions on the paper by Martha Herbert and Julie Buckley (see here) on similar things. Other than that, we've got a bit of a scientific black hole when it comes to the question of whether such a very restrictive dietary intervention could 'help' where autism is present and who might be best responders.The paper by David Ruskin and colleagues**** (open-access) which I'm finally getting to after quite a long-winded introduction, represents an addition to that autism-ketogenic diet literature and their observations of the BTBR 'Dangermouse' when on a ketogenic diet. OK I've exaggerated slightly. The BTBR mouse model of autism is not really Dangermouse; just a name I've assigned from my mis-spent youth watching far too much TV (see this post). But it is still quite a good mouse model of autism despite some recent criticism.The Ruskin paper is open-access so I'm not going to go over the top with any description. It went something like: take several BTBR mice. House them with other mice (C57Bl/6). At 5 weeks of age, feed some of the mixed caged mice a ketogenic diet (KD) and others a control diet. Test mouse behaviour at 3-5 weeks of diet. Report results.The results: well, the KD mice were certainly showing signs of ketosis as per some blood chemistry results including some much lower blood glucose levels (interesting!*****). There were also some interesting differences recorded to elements of mouse behaviour as a function of the use of the KD or not and mouse strain: "the KD did not affect behavior in C57Bl/6 mice". Importantly "the beneficial behavioral effects of the KD are not secondary to its well-known efficacy against epilepsy and seizure activity".OK, it's another study of mouse behaviour and making the quite considerable leap from a proposed mouse model of autism to real-life autism. Mouse behaviour is not human behaviour (he says cleaning his whiskers). I'm no expert on how one goes about examining and testing mouse behaviour so I'll have to assume that the authors knew what they were doing and did it to the best of their abilities. I'm not necessarily expecting the Ruskin study to mark any substantial shift in opinion on how people view the research area of diet and autism it has to be said.What this study does offer though, is another potentially fascinating glimpse into how diet might be related to some cases of autism. Indeed, whether the whole or facets of the intervention are worthy of much greater study. For example, I earlier mentioned Tim Buie's work on carbs and autism. The question is whether the lower carbohydrate load attached to a ketogenic diet might be the more important variable over and above fat, bearing in mind that there might be issues there too? Similarly, the authors ask whether the ketogenic diet might be something to consider where autism and certain types of epilepsy exist; as per another quote: "a KD could offer dual benefits in this difficult clinical population". Bear in mind however, I offer nothing like medical or clinical evidence by suggesting all this. Just speculating.To close and paying homage to the era of Dangermouse (1980s), here's Neneh and Buffalo Stance.. ("know wot I mean?")----------* Buie T. The relationship of autism and gluten. Clin Ther. 2013; 35: 578-583.** Asperger H. Psychopathology of children with coeliac disease. Ann Paediatr. 1961; 197: 346-351.*** Evangeliou A. et al. Application of a ketogenic diet in children with autistic behavior: pilot study. J Child Neurol. 2003; 18: 113-118.**** Ruskin DN. et al. Ketogenic diet improves core symptoms of autism in BTBR mice. PLoS ONE. 2013; 8: e65021.****... Read more »
Ruskin, D., Svedova, J., Cote, J., Sandau, U., Rho, J., Kawamura, M., Boison, D., & Masino, S. (2013) Ketogenic Diet Improves Core Symptoms of Autism in BTBR Mice. PLoS ONE, 8(6). DOI: 10.1371/journal.pone.0065021
Los Alamos National Laboratory scientists have designed a new type of nanostructured-carbon-based catalyst that could pave the way for reliable, economical next-generation batteries and alkaline fuel cells, providing for practical use of wind- and solar-powered electricity, as well as enhanced hybrid electric vehicles.... Read more »
Chung, H., Won, J., & Zelenay, P. (2013) Active and stable carbon nanotube/nanoparticle composite electrocatalyst for oxygen reduction. Nature Communications, 1922. DOI: 10.1038/ncomms2944
Why do we connect and collaborate, deciding to "walk in the light of creative altruism" instead of the "darkness of destructive selfishness"? Is it because of subtle behavioral clues that make us "click" and consider the other person a part of the group? Or is it because it smells like team spirit? It very well might be. We (literally) smell love, victory, fear, along with chemicals that motivate us to cooperate. As was recently shown in double-blind placebo-controlled studies that quantitatively measured generosity and cooperation. Androstadienone, a rather unpleasant smelling molecule abundant in male sweat could make us more cooperative and more likely to think of the other person as "one of us". This molecule, created from male sex hormone testosterone possibly with the help of coryneform bacteria living under arms, was previously shown to have an effect on women - depending on social context and the time in their menstrual cycle. Even though androstadienone does not smell particularly plaasant - rather musky, with subtle urine-like and alcohol notes - merely smelling it is sufficient to maintain high levels of energy-boosting hormone cortisol - possibly by inhibiting an enzyme (the 11β-hydroxysteroid dehydrogenase type 1 aka 11β-HSD1) responsible for its reactivation from cortisone.AndrostadienoneAndrostadienone is related to another steroid estratetraenol found in the urine of pregnant women. Both molecules in large concentrations can affect mood - improving it in females (also increasing their feeling of being focused and sensitivity to pain) while suppressing males. High testosterone males might even get depressed. So it might not be a good idea to sweat too much, but the right amount of sweating is actually helpful. If you are a male. When it comes to men deciding to cooperate with women, chemistry alone is less helpful. As in the old monkey experiment (Michael and Zumpe, 1982) where the best female strategy was to block male's access to other female monkeys. So, don't sweat it ladies. Just be dominant.REFERENCESHuoviala P, & Rantala MJ (2013). A Putative Human Pheromone, Androstadienone, Increases Cooperation between Men. PloS one, 8 (5) PMID: 23717389Lundström JN, Hummel T, & Olsson MJ (2003). Individual differences in sensitivity to the odor of 4,16-androstadien-3-one. Chemical senses, 28 (7), 643-50 PMID: 14578126 Michael RP, Zumpe D. (1982) Influence of olfactory signals on the reproductive behaviour of social groups of rhesus monkeys (Macaca mulatta). J Endocrinol. 95(2):189-205. PMID: 7175415... Read more »
Huoviala P, & Rantala MJ. (2013) A Putative Human Pheromone, Androstadienone, Increases Cooperation between Men. PloS one, 8(5). PMID: 23717389
Lundström JN, Hummel T, & Olsson MJ. (2003) Individual differences in sensitivity to the odor of 4,16-androstadien-3-one. Chemical senses, 28(7), 643-50. PMID: 14578126
The most commercially popular negative electrode material used in lithium-ion batteries is graphite. While silicone could be a much more efficient choice, all silicon-based designs have a major flaw—these structures tend to crack or break easily when they are used repeatedly.... Read more »
Wu, H., Yu, G., Pan, L., Liu, N., McDowell, M., Bao, Z., & Cui, Y. (2013) Stable Li-ion battery anodes by in-situ polymerization of conducting hydrogel to conformally coat silicon nanoparticles. Nature Communications. DOI: 10.1038/ncomms2941
Waking up thousands of miles from home was a normal occurrence in the summer months as a child. I was never the first awake, there was always one who was waiting for me. To say my grandfather was an early … Continue reading →... Read more »
Verbenko V. N., Kuznetsova L. V., Krupyan E. P., & Suslov A. V. (2009) Operator-constitutive mutation in the recA gene enhances radiation resistance of Escherichia coli. Russian Journal of Genetics, 45(8), 917-923. DOI: 10.1134/S1022795409080043
Slade Dea, Lindner Ariel B., Paul Gregory, & Radman Miroslav. (2009) Recombination and Replication in DNA Repair of Heavily Irradiated Deinococcus radiodurans. Cell, 136(6), 1044-1055. DOI: 10.1016/j.cell.2009.01.018
Howard-Flanders Paul, West Stephen C., & Stasiak Andrzej. (1984) Role of RecA protein spiral filaments in genetic recombination. Nature, 309(5965), 215-220. DOI: 10.1038/309215a0
Physicist Florian Nitze at the Umeå University, Sweden, has developed several new catalysts that improve the capacity of the fuel cells, making it possible to use relatively environmentally friendly formic acid in fuel cell powering your mobile phone or laptop.... Read more »
Nitze, F., Mazurkiewicz, M., Malolepszy, A., Mikolajczuk, A., Kędzierzawski, P., Tai, C., Hu, G., Kurzydłowski, K., Stobinski, L., Borodzinski, A.... (2012) Synthesis of palladium nanoparticles decorated helical carbon nanofiber as highly active anodic catalyst for direct formic acid fuel cells. Electrochimica Acta, 323-328. DOI: 10.1016/j.electacta.2011.12.104
Imagine if you could open up your brain and look inside. What you would see is a network of nerve cells called neurons, each with its own internal highway system for transporting essential materials between different parts of the cell. When this biological machinery is operating smoothly, tiny motor proteins ferry precious cargo up and … Read More →... Read more »
Gunawardena S, Yang G, & Goldstein LS. (2013) Presenilin controls kinesin-1 and dynein function during APP vesicle transport in vivo. Human molecular genetics. PMID: 23710041
University of Illinois at Urbana-Champaign researchers have developed a cradle and app for the iPhone that uses the phone’s built-in camera and processing power as a biosensor to detect toxins, proteins, bacteria, viruses and other molecules. Having such sensitive biosensing capabilities in the field could enable on-the-spot tracking of groundwater contamination, combine the phone’s GPS … Read More →... Read more »
Duke University engineers have developed a new safer method for catalytic hydrogen production. According to the authors of the study, it does not require high temperatures and produces smaller amounts of toxic chemicals than other industrial hydrogen production technologies.... Read more »
Shodiya, T., Schmidt, O., Peng, W., & Hotz, N. (2013) Novel nano-scale Au/α-Fe2O3 catalyst for the preferential oxidation of CO in biofuel reformate gas. Journal of Catalysis, 63-69. DOI: 10.1016/j.jcat.2012.12.027
Devices for artificial photosynthesis are often called “artificial leaves”. This leaves, however, are of no use unless you can create an “artificial forest” from them. Now, scientists with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory have reported the first fully integrated nanosystem for artificial photosynthesis.... Read more »
Liu, C., Tang, J., Chen, H., Liu, B., & Yang, P. (2013) A Fully Integrated Nanosystem of Semiconductor Nanowires for Direct Solar Water Splitting. Nano Letters, 2147483647. DOI: 10.1021/nl401615t
A new study shows how complex biochemical transformations may have been possible under conditions that existed when life began on the early Earth.... Read more »
Georgia Institute of Technology. (2013) RNA was capable of catalyzing electron transfer on early earth with iron's help, study shows. Georgia Institute of Technology. info:/
A new study by scientists at Duke University and the U.S. Geological Survey (USGS) finds no evidence of groundwater contamination from shale gas production in Arkansas.... Read more »
Warner, N., Kresse, T., Hays, P., Down, A., Karr, J., Jackson, R., & Vengosh, A. (2013) Geochemical and isotopic variations in shallow groundwater in areas of the Fayetteville shale development, north-central Arkansas. Applied Geochemistry. DOI: 10.1016/j.apgeochem.2013.04.013
Photosynthetic oxidation of water is one of the central processes of life on Earth, but it is still not completely understood. Now, a German-American team of scientists has set out to observe the intermediate stages of this complex catalytic reaction using ultrashort snap shots taken at light sources including BESSY II in Berlin and the Linac Coherent Light Source at Stanford.... Read more »
Kern, J., Alonso-Mori, R., Hellmich, J., Tran, R., Hattne, J., Laksmono, H., Glockner, C., Echols, N., Sierra, R., Sellberg, J.... (2012) Room temperature femtosecond X-ray diffraction of photosystem II microcrystals. Proceedings of the National Academy of Sciences, 109(25), 9721-9726. DOI: 10.1073/pnas.1204598109
A team of Canadian and UK researchers has discovered what may be some of the oldest pockets of water on the planet – and they may contain life.... Read more »
Kim Luke, University of Toronto, Office of Public Relations, McMaster University, Aeron Haworth, The University of Manchester, & Lancaster University, News. (2013) Water's secrets. Tracing Knowledge. info:/
Using a combination of microanalytic techniques that at the same time image photoelectric current and chemical reaction rates across a surface on a micrometer scale, researchers at the National Institute of Standards and Technology (NIST) have shed new light on what may become a cost-effective way to generate hydrogen gas directly from water and sunlight.... Read more »
Esposito, D., Levin, I., Moffat, T., & Talin, A. (2013) H2 evolution at Si-based metal–insulator–semiconductor photoelectrodes enhanced by inversion channel charge collection and H spillover. Nature Materials. DOI: 10.1038/nmat3626
"Simple" is often a compliment in the human world, used to describe low-fuss dinners or closet solutions. When scientists use "simple" to describe an animal, they mean something more like, "That sac of goo has no business acting clever." An especially simple creature—a sea slug—recently demonstrated that despite its humble resources, it can learn from experience and form new hunting strategies. Smaller goo sacs, beware.
Despite its squishy stature, the sea slug Pleurobranchaea californica is a killer. It roams the sea and swallows whatever appealing morsels are in its way. Being blind, it can't tell how tasty its prey looks—or doesn't.
It can't see, for example, the flashy coloration of the "Spanish shawl" nudibranch (Flabellina iodinea). If it could, it might guess that those bright pink and orange hues are a warning: Flabellina is not nice to eat. It steals stinging cells from its own prey (such as corals and anemones) and stores those stingers in its bristles.
Rhanor Gillette, a neuroscientist at the University of Illinois, Urbana-Champaign, observed that not only do Pleurobranchaea slugs spit out Spanish shawls, but they seem to remember and avoid the animals in the future. To study how well the predatory sea slugs learn their lesson after tasting Flabellina, he and graduate student Vanessa Noboa set up a meet-and-greet between the two species.
In tanks, the large, hungry sea slugs encountered the smaller nudibranchs. Researchers recorded how long it took for Pleurobranchaea to take a taste, then waited for the slugs to change their minds and turn away from their potential prey. (Here's a great video of a Pleurobranchaea attempting to Hoover up a Flabellina, then spitting the animal back out. While the big slug pivots away in disgust, the little one does its "Don't eat me" dance like nobody's watching, which is true.)
On the first day, this interaction happened five times. By the end, most of the Pleurobranchaea slugs were much slower to take a taste of the Spanish shawls, or were ignoring them altogether. Twenty-four hours later, the sea slugs were still reluctant to approach Flabellina. Even after 72 hours, they remembered what they'd learned. Gillette and Noboa report their results in the Journal of Experimental Biology.
Since the predatory slugs seem to sniff something in the water that makes them turn away, the researchers think the noxious Spanish shawls give off a distinctive warning odor.
Gillette says the sea slugs have a decent memory, considering their elementary nervous system. "In these experiments their memory is strong at 48 hours," he says, "and in unpublished work we've seen savings up to a week, so it's not bad." (Oddly, some slugs had to be removed from the experiment because they didn't mind the taste of the stinging Flabellina at all. They sucked it up just like any other food.)
Learning from an unpleasant taste experience, then using that memory to change one's hunting strategy, is "a real cognitive trait," Gillette says—in other words, a "goal-directed use of knowledge." The Pleurobranchaea slugs learned to avoid the smell of Flabellina, although they continued to eat a related, non-stinging species without hesitation.
Being able to change their feeding strategy is a good thing, since these slugs are generalists. Everything in the path of their oozing is a potential meal. "More specialized animals, say sea-slugs that may munch on a particular kind of sponge, may not need to employ such learning abilities," Gillette says. For a hunter like Pleurobranchaea, the decisions aren't so simple.
Noboa, V., & Gillette, R. (2013). Selective prey avoidance learning in the predatory sea-slug Pleurobranchaea californica Journal of Experimental Biology DOI: 10.1242/jeb.079384
Image: Rhanor Gillette.
... Read more »
Noboa, V., & Gillette, R. (2013) Selective prey avoidance learning in the predatory sea-slug Pleurobranchaea californica. Journal of Experimental Biology. DOI: 10.1242/jeb.079384
The newly-sequenced scarlet macaw genome will provide many important insights into avian and human biology, behaviours and genetics and will contribute to parrot conservation.... Read more »
Seabury Christopher M., Dowd Scot E., Seabury Paul M., Raudsepp Terje, Brightsmith Donald J., Liboriussen Poul, Halley Yvette, Fisher Colleen A., Owens Elaine, & Viswanathan Ganesh. (2013) A Multi-Platform Draft de novo Genome Assembly and Comparative Analysis for the Scarlet Macaw (Ara macao). PLoS ONE, 8(5). DOI: 10.1371/journal.pone.0062415.s019
Oleksyk Taras K, Pombert Jean-Francois, Siu Daniel, Mazo-Vargas Anyimilehidi, Ramos Brian, Guiblet Wilfried, Afanador Yashira, Ruiz-Rodriguez Christina T, Nickerson Michael L, & Logue David M. (2012) A locally funded Puerto Rican parrot (Amazona vittata) genome sequencing project increases avian data and advances young researcher education. GigaScience, 1(1), 14. DOI: 10.1186/2047-217X-1-14
Heavy metal poisoning is a major health concern across the world. Heavy metal ions frequently leak into the environment from industrial waste causing multiple health problems in humans, animals, and other organisms. While there is no universally accepted definition of … Continue reading →... Read more »
Bertin G., & Averbeck D. (2006) Cadmium: cellular effects, modifications of biomolecules, modulation of DNA repair and genotoxic consequences (a review). Biochimie, 88(11), 1549-1559. DOI: 10.1016/j.biochi.2006.10.001
Schwager Stephan, Lumjiaktase Putthapoom, Stöckli Martina, Weisskopf Laure, & Eberl Leo. (2012) The genetic basis of cadmium resistance of . Environmental Microbiology Reports, 4(5), 562-568. DOI: 10.1111/j.1758-2229.2012.00372.x
LEE JENNIFER G., ROBERTS SAMANTHA B., & MOREL FRANÇOIS M. M. (1995) Cadmium: A nutrient for the marine diatom Thalassiosira weissflogii. Limnology and Oceanography, 40(6), 1056-1063. DOI: 10.4319/lo.1922.214.171.1246
Our star, the Sun, provides most of the energy on this planet. (Essentially, all the energy except for nuclear, comes directly or indirectly from it.) Our current methods of converting solar radiation into electricity (photovoltaics) are not very efficient in comparison with plants. Researchers at the University of Georgia looked to nature for inspiration, and they are now developing a new technology that makes it possible to use plants to generate electricity.... Read more »
Calkins, J., Umasankar, Y., O'Neill, H., & Ramasamy, R. (2013) High photo-electrochemical activity of thylakoid–carbon nanotube composites for photosynthetic energy conversion. Energy . DOI: 10.1039/C3EE40634B
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