Research Blogging - All Topics - English

Nutrition and protein: training, performance and long-term health.

2012-05-25T20:18:03Z

These are interwoven issues. The aim of training is improve the body’s ability to perform certain tasks (and in the case of CrossFit it is to achieve a high degree of effectiveness and competence in a wide range of skills and efforts). The goal of nutrition in training is to help the body (the entire thing) adapt and remodel, or at least maintain what you have and can do. Bodies like efficiency. Your body will see no point in maintaining bone or muscle that does not look like it’s going to be used any time soon and will let it go. That’s why people who have been ill and disabled for a long time become so frail. When challenged your body (which means here not only muscle and bone, but brain, nerves, biochemical pathways and efficiency, cell proliferation and organelle numbers and function, and neurotransmitters) changes to meet that particular challenge. Protein is important here for repair, strengthen and reinforcement of stressed tissue. Strength-oriented athletes have traditionally made efforts to increase protein intake and there is some evidence that this is effective in increasing muscle mass. There is also evidence that increasing protein intake can reduce the rate of loss of muscle mass seen in aged people. Not all of the protein you can consume will be used to increase mass. Your body will use what it needs, or what it anticipates needing in the near future (in case you persist in doing all those squats, jerks, kettle bell swings and pushups.) Consuming a lot of protein will probably not hurt you. Not consuming enough will slow repair and limit your ability to adapt to physiological and mechanical stress. Endurance athletes have long been encouraged to eat plenty of carbohydrates since availability of carbs can be a limiting factor in performance. This is why consuming dilute fruit juice (or sugar water) can delay exhaustion and allow an athlete to continue to run, bike or whatever longer than they would if they had been drinking plain water. However if you are always running on carbohydrates you may not adapt biochemically speaking. Normally, if you are low on carbohydrates (or glycogen) your body will attempt to increase the rate at which is uses its own fat stores for energy. Being habitually low on carbs will increase your ability to generate energy by other means. You will probably be uncomfortable for at least a while, but you should improve at this the longer you train. So . . . while training, remember that you are training more than muscles. A lot of people involved with CrossFit advocate some interesting dietary approaches. It probably won't hurt you, and for a lot of people it will be better than what they were eating before. Keeping with the program helps people bond and gives them a sense of control. That can be very good, as long as it doesn't get too rigid or ridiculous. There are really too many unknowns floating around at present to know exactly what is best. What is best probably varies by individual, situation, stage of life, and training goals. New information becomes available. We'll see how things fall out. Churchward - Venne, T., Burd, N., Phillips, S., & Research Group, E. (2012). Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism Nutrition & Metabolism, 9 (1) DOI: 10.1186/1743-7075-9-40 Logan-Sprenger, H., Heigenhauser, G., Killian, K., & Spriet, L. (2012). The effects of dehydration during cycling on skeletal muscle metabolism in females Medicine & Science in Sports & Exercise DOI: 10.1249/MSS.0b013e31825abc7c Symonsi, T., Sheffield-Moore, M., Mamerow, M., Wolfe, R., & Paddon-Jones, D. (2010). The anabolic response to resistance exercise and a protein-rich meal is not diminished by age The journal of nutrition, health & aging, 15 (5), 376-381 DOI: 10.1007/s12603-010-0319-z...

Churchward - Venne, T., Burd, N., Phillips, S., & Research Group, E. (2012) Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutrition , 9(1), 40. DOI: 10.1186/1743-7075-9-40

Logan-Sprenger, H., Heigenhauser, G., Killian, K., & Spriet, L. (2012) The effects of dehydration during cycling on skeletal muscle metabolism in females. Medicine , 1. DOI: 10.1249/MSS.0b013e31825abc7c

Symonsi, T., Sheffield-Moore, M., Mamerow, M., Wolfe, R., & Paddon-Jones, D. (2010) The anabolic response to resistance exercise and a protein-rich meal is not diminished by age. The journal of nutrition, health , 15(5), 376-381. DOI: 10.1007/s12603-010-0319-z

Neuroscientists should study Zombie Ants

2012-05-25T15:32:00Z

Zombie ant controlled by fungus (source)The fungus-controlled zombie ant is one of natures' greatest wonders. A fungus (e.g. O. Unilateralis) is inhaled by an ant (e.g. Camponotus Leonardi), and begins to grow inside its body. Eventually the fungus infests the brain of the ant, causing it to drunkenly wander, periodically convulse, climb up a leaf and clamp down on its ridge. Once the ant is securely in place, the fungus devours the brain and innards of the ant and grows out the back of its head often (but not always) releasing its spores onto the ground below. Un-freaking-believable, right?As if this wasn't amazing enough, it's not like it is only one fungus species that infects only one ant species. There are many of these fungi and they infect many different kinds of insect, but somehow maintain a species specificity. In other words, fungus#1 can infect SpeciesX, but not SpeciesY, and Fungus#2 infects SpeciesY, but not SpeciesQ, and so forth. So WHY does this happen? and HOW has no one looked at the brain cells of these ants? Though no one has looked at the brains of these ants, Last year a paper painstakingly characterized their behavior under 'fungi control'. The most interesting characteristics are:The ants display a 'drunkard's walk' (the author's words)The ants periodically spasm and fall down (if they are above ground level)The ants clamp down on the underside main vein of a leaf (never the side of the leaf, never the top) Interestingly they all bite down on the leaf around solar noon.Figure 1, Hughes et al., 2011This figure shows the behavior of several ants. Each ant was observed during the time of the horizontal blue bar. The black vertical lines and 'spasms' which caused the ants to fall down (gray stars), and the red triangles are when the ant bit down on the leaf ridge. Because we have no idea how the fungus is manipulating the ant, let's wildly speculate.1. The Drunken Walk:Why: The reason for this is not clear. The ant doesn't go far, so the non-directional walking could be to keep it close to more ants.How: The mechanism is also not clear, but usually an ants directional walking could be following a pheromone trail. The fungus could presumably cause random walking by confusing the ants ability to sense pheromones. It could possibly even cause 'hallucinatory' pheromone sensing.2. The Periodic Spasms: Why: The authors speculate that the purpose of these spasms is to keep the ant near the ground. The infect ants spend much more time on the ground level than the uninfected ants, and the spasms are often followed by a fall.How:A fungus could essentially cause a seizure in the ants brain by manipulating potassium or calcium channels. On the other hand, I suppose the fungus could be acting directly on the muscles, causing them to twitch in an uncontrolled way. 3. The Clamping: Why: This has an obvious function, to root the ant for ultimate fungal growth and dispersion. How: First of all, biting and even walking on leaves is not something these ants normally do. So the fungus isn't just hijacking a behavior that the ant already has, it's basically creating a new one. The correlation with solar noon indicates that a light or heat signal could contribute to the trigger, but basically nothing else is known about it. Interestingly, the clamping does not always have to be one single event either. A few of the ants clamped down on the leaf vein more than once. The authors of this paper spend time discussing fungi's direct effect on the mandible muscles of the ant.Figure 3 Hughes et al., 2011They show that the mandible muscles of the normal ant are fat and healthy (B), but the muscles of the infected ant are separated and reduced in size (C). Though this image is of an ant at the moment of biting, the authors suggests that the deterioration of the mandible muscle might be to prevent re-opening of the clamp. They do not speculate on how the clamp is initiated in the first place, or why it occurs at noon. So please, fellow neuroscientists, somebody stain these brains! It's just too fascinating to resist exploration. What proteins are altered? What is the receptor composition of behaviorally-specific neurons? Are the dendrites differently shaped? And who knows what sort of great advances might be hidden in these brain-controlling fungi. The magic of optogenetics comes from lowly light-sensitive bacteria, just think of the possibilities hidden in brain-controlling fungus. To be fair, some neuroscience has been done on parasitic brain control, but it is very limited. In fact it is limited to basically one histological study about parasitic worms who infest crickets and cause them to drown themselves (the subject of a future blog post). However, suicide-crickets are no zombie-ants and the exact mechanisms of the interaction © TheCellularScaleHughes DP, Andersen SB, Hywel-Jones NL, Himaman W, Billen J, & Boomsma JJ (2011). Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection. BMC ecology, 11 (1) PMID: 21554670...

Hughes DP, Andersen SB, Hywel-Jones NL, Himaman W, Billen J, & Boomsma JJ. (2011) Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection. BMC ecology, 11(1), 13. PMID: 21554670

Once upon a time there was a star

2012-05-25T15:14:59Z

Why do we think that Population III stars exist? The term “Population III” could be assigned to two types of stars: “1) the ones which form out of the pristine gas left over after cosmological nucleosynthesis and generated the first metals; and 2) the ones which have been hypothesized to provide the dark matter in galactic halos” – Carr. The first type definitely exists, since we have metals in our disposal, and we know that elements heavier than H and He could only be generated through stellar nucleosynthesis. The second type, however, not necessarily exist, because first galactic halos could also be made of some ancient pre-atomic particles. I am going to discuss the first type of Population III stars. Note that both types of Population III stars might have formed during the first phase of galaxy formation or even before first galaxies were formed....

ResearchBlogging.org, & Bromm V. and Larson R. (2009) The First Stars in the Universe . Scientific American. info:/

Bromm, V. (2010) The Very First Stars: Formation and Reionization of the Universe. Proceedings of the International Astronomical Union, 5(S265), 27. DOI: 10.1017/S1743921310000116

Stacy, A., Greif, T., & Bromm, V. (2010) The first stars: formation of binaries and small multiple systems. Monthly Notices of the Royal Astronomical Society, 403(1), 45-60. DOI: 10.1111/j.1365-2966.2009.16113.x

Friday Fun: A Week in the Life of a Grad Student

2012-05-25T13:15:02Z

As a graduate student, I don't punch a clock or fill out a time card. Although I have a faculty advisor, I don't have a boss - no one is keeping count of my hours. Most of my work time is spent doing a variety of tasks related to research or teaching, and these often change from week to week. I love the freedom and diversity of the academic life, but the lack of structure means that at the end of the week I'm often unsure of how exactly I spent my time. I like to get a good nights' sleep, so that certainly helps... but for the other 15 or so hours in my day, what exactly am I doing? This question intrigues me and for the past several months I've been thinking I should keep a log of my happenings to see how my days are spent. So I finally did it back in April. I created a word doc dedicated to the cause, and updated it every time I changed tasks Monday through Friday. I also kept a quick count of how much time I spent working on the weekend. It wasn't the most ordinary week with canceled meetings and a weekend visit to my hometown. But really, is any week "ordinary"? So I figured I'd just go ahead and do it while I was motivated. Read More->...

Coker, B. (2011) Freedom to surf: the positive effects of workplace Internet leisure browsing. New Technology, Work and Employment, 26(3), 238-247. DOI: 10.1111/j.1468-005X.2011.00272.x

I'm Older and I Have More Insurance

2012-05-25T13:02:48Z

If you've seen the 1991 movie Fried Green Tomatoes then you will remember this wonderful scene:Believe it or not, this scene actually relates to today's post about territorial behavior in parking lots.You are probably familiar with the concept of territorial behavior. In animals it typically involves occupying a defined territory and marking and defending it against interlopers. This territory is desirable because it contains resources (food, mates, etc.). However, there can be risk involved in defending this territory, risk that must be weighed in a sort of cost-benefit analysis. If the risk is low you defend the territory and if it is too high you flee it. Now what about public territories? Those places that do not belong to any one individual but instead an individual occupies a portion of it for a short period of time. In this case the territory is less important to the individual, and they only have minimal rights to occupy it. However, individuals occupying space in a public territory can show some territoriality. If you get a little more psychological with this train of thought then you start using terms such as "symbolic value," "identity," "control," and "competence." Basically, this is a way of explaining why an individual may defend a territory even if there is nothing to be protected or gained. And that is where we pick up the parking lot study.An older paper published in the Journal of Applied Social Psychology tested these territorial behaviors in people leaving parking lots. The video example is of Evelyn Couch entering a parking lot and looking for territory. Here, the researchers are interested in whether the occupants of parking spaces defended those spaces even though their task at the location was complete and the space/territory no longer served any purpose for them. As with many psychological papers, this was broken down into three studies.Study 1: Do departing drivers take longer to leave their parking spaces when someone is waiting for the space?Here, the researchers observed 200 drivers in a mall parking lot and timed how long it took them to leave their parking spaces. The spaces were of prime real estate, in terms of mall parking, being the closest 52 spaces (excluding handicapped spaces) to the mall entrance. They started timing from when the departing shopper opened their car door until they had completely left the parking space, also noting if another driver was waiting for the departing driver's space. They also noted if the departing driver turned their head toward the waiting driver. They found that departing drivers took longer to leave their parking spaces if someone else was waiting for it. From this study it is unclear as to why they took longer. Sure, it could have been territoriality, but it also could have been caution to prevent collisions, distraction, or all sorts of other reasons.Study 2: Do departing drivers take longer to leave their spaces because they are territorial or because of some other reason?To test this they looked at four intrusion conditions (intrusion being the waiting car) in comparison to a no-intrusion condition. They also tested the distraction hypothesis by having someone drive by the subjects, independent of whether there was a car waiting for the space or not. They also tested the level of intrusion by having someone honk or not honk their horns. This study also found that drivers took longer to leave their parking spaces when another driver was waiting, regardless of the added distraction of a another car passing by. These departing drivers also took longer when the waiting driver was honking at them versus when they were not honking. Additionally, they found that male drivers took longer to leave than female drivers if the waiting car was of lower status or value than theirs. All findings that suggest territorial behavior.Study 3: Are people aware of how a waiting driver affects how much time they take leaving a parking space?In this study, the researchers gave questionnaires to 100 people who had parked at a shopping mall. This questionnaire contained scales that allowed the drivers to rate how they would feel while leaving a parking lot under three conditions: with no one waiting, with one driver waiting, and with a driver waiting who honks their horn. They also rated their beliefs about how a driver waiting for their space and and honking driver waiting for their space would affect how long it would take them and others to leave. The survey results showed that people recognized their territorial behaviors but would leave faster if a car were waiting for them but not if that car honked at them.I gotta say that if someone was sitting behind my car honking their horn at me to move faster that I would take my sweet time too. I don't even like that slow, creepy-, stalker-follow people do when they see you walking to your car. I'm tempted to weave through the aisles just to get them to stop.Next I'd like to find a study that looks at how well people park between the lines in a parking space and how much space they leave on either side. If I have to crawl in through the passenger side of my car one more time I might start handing out tickets for parking like a jackass.Ruback, R., & Juieng, D. (1997). Territorial Defense in Parking Lots: Retaliation Against Waiting Drivers Journal of Applied Social Psychology, 27 (9), 821-834 DOI: 10.1111/j.1559-1816.1997.tb00661.x...

Ruback, R., & Juieng, D. (1997) Territorial Defense in Parking Lots: Retaliation Against Waiting Drivers. Journal of Applied Social Psychology, 27(9), 821-834. DOI: 10.1111/j.1559-1816.1997.tb00661.x

Brain Connectivity Alterations in OCD

2012-05-25T11:51:41Z

Obsessive compulsive disorder (OCD) is an anxiety disorder characterized by intrusive thoughts interfering with everyday activities. The prevalence of OCD is estimated to be between 1 to 2 percent of the population. Despite several approved drug treatments and the availability of behavioral therapy, many individuals with OCD find their symptoms resistant to treatment. A better understanding of the underlying pathophysiology of OCD is needed for the development of more effective treatment.A recent brain imaging study provides some additional insight into the connectivity alterations found in those with OCD. In this study, 30 subjects with OCD were compared to a group of 32 control subjects using functional magnetic resonance imaging. The subjects were studied for functional connectivity of the default mode network (DFM) as well as the fronto-parietal network (FPN).The default mode network is the working network of brain regions typically active "at rest" when no specific brain-related task is being performed. You might think of this as what brain regions are in synchronization with each other during rest. We know that individuals with OCD commonly find their resting brain state is disrupted by their intrusive obsessional thoughts. This makes study of the default mode network promising for understanding OCD.The key findings in OCD from this study were:Reduction in the typical negative correlation between the DFM and the FPNAltered connectivity between the anterior insula and multiple DFM regions including the parahippocampus, medial frontal cortex, posterior cingulate cortex, and the posterior inferior parietal lobeIncreased connectivity of the FPN with regions outside the DFM including the thalamus, lateral frontal cortex and somatosensory/motor brain regionsThe authors note "Though speculative, the current findings of attenuated negative connectivity between anterior insula and DMN suggest a potential neural basis for the difficulty OCD patients may have in efforts to disengage from internal mental processes in order to respond to more appropriately salient external information related to potential risk (such as that informing them that dreaded events have not or will not occur)."The authors also note their study may not represent findings specific to OCD but may be related to broader anxiety conditions. This will need to be explored by contrasting differences (and similarities) across OCD with other anxiety disorders such as generalized anxiety disorder, panic disorder, social anxiety disorder and PTSD.This study is indicative of the evolving conceptualization of many mental disorders. Many mental disorders appear to not be due to a single neurotransmitter abnormality or a localized brain lesion but appear to be abnormalities of brain circuitry. Functional brain connectivity imaging of the DMN holds promise as a tool to better understand these circuitry alterations.Photo of female adult black bear from Lake Istasca State Park from the author's files.Stern, E., Fitzgerald, K., Welsh, R., Abelson, J., & Taylor, S. (2012). Resting-State Functional Connectivity between Fronto-Parietal and Default Mode Networks in Obsessive-Compulsive Disorder PLoS ONE, 7 (5) DOI: 10.1371/journal.pone.0036356...

Stern, E., Fitzgerald, K., Welsh, R., Abelson, J., & Taylor, S. (2012) Resting-State Functional Connectivity between Fronto-Parietal and Default Mode Networks in Obsessive-Compulsive Disorder. PLoS ONE, 7(5). DOI: 10.1371/journal.pone.0036356

Octopuses Host a Masterclass on Hiding

2012-05-25T11:02:02Z

When you're surrounded by an ocean full of potential predators, the best way to avoid seeing the inside of one's stomach is to make sure none of them see you in the first place. Octopuses and some other cephalopods are experts at camouflage, manipulating the colors and textures of their skin to hide in plain sight. But their strategy, it turns out, has nothing to do with disappearing into the background. To learn the camouflaging secrets of the masters, researchers led by Noam Josef at Ben-Gurion University of the Negev in Israel went scuba diving. On reefs in the Red Sea and Tyrrhenian Sea, they snapped pictures of two octopus species (Octopus cyanea and O. vulgaris) whenever they saw an individual hiding—crouched low and motionless for a minute or longer. For the pictures to work in the team's digital image analysis, they had to be sunlit just so and taken from directly above. Over three years, they captured just 11 photos that fit their criteria. "These images are a bit hard to get," Josef said in an email. Not to mention the challenge of finding a camouflaged octopus in the first place. Hint: Look for the coral with tentacles. Each bird's-eye, or rather shark's-eye, photo was converted to a grayscale image. Researchers selected a rectangle showing the pattern on the octopus's mantle (the part that's not tentacles). Then a software algorithm compared the mantle sample to rectangles from everywhere else in the photo, shifting the frame one pixel at a time and searching for a match. The best matches to the octopuses' camouflage patterns were not to be found in the gravely ground beneath them. Instead, 10 out of the 11 octopuses had clearly mimicked a specific object nearby. They played coral, rock, weird sand blob, or algae patch. View this picture larger and you'll see that one coral has eyes on top. A camouflaged animal's best strategy depends on the viewpoint of its predators. Many fish have light-colored bellies that blend in with the sky when seen from below. Certain pygmy sharks take this trick a step further and emit a blue glow from their undersides. When viewed from above, fishes' darker-colored backs vanish into the background of the ocean. An octopus sitting on a reef has to worry about big fish hunting from above, as well as moray eels and other predators that creep up from the sides. Since these enemies approaching from different angles will see the octopus framed against different backdrops, maybe it makes sense for the octopus to forgo blending in altogether. It's stuck being obvious, so it may as well pose as an obvious object that's less edible. "Sometimes octopuses make an honest mistake and simply become conspicuous" by camouflaging, Josef says. "However, in a complex environment like the coral reef, acquiring key features of an object may serve the octopus better than just matching the general look of the reef." You can see a few of those convincing key details in the photos above, where octopuses have contorted themselves into the knobby branches of a coral or a shell's striped ridges. Scientists have discovered some of the specialized cells in octopus skin that help them pull off their elaborate imitations—pigment holders, reflectors, light scatterers. But Josef says there are still more questions than answers: "What visual cues are used by these animals? How do octopuses match their colors even though they're colorblind?" (Yes. Colorblind.) "What information is transmitted from the eye to the brain? And what does an octopus really see?" We're still "far from understanding" the camouflaging act of the octopus, Josef says. We'll have to keep hunting for scraps of information the cunning cephalopods let slip. That is, assuming we can find them first. Josef, N., Amodio, P., Fiorito, G., & Shashar, N. (2012). Camouflaging in a Complex Environment—Octopuses Use Specific Features of Their Surroundings for Background Matching PLoS ONE, 7 (5) DOI: 10.1371/journal.pone.0037579 Images: Top, Ms. Keren Levy. Middle and bottom, Mr. Zvika (Ziggy) Livnat....

Josef, N., Amodio, P., Fiorito, G., & Shashar, N. (2012) Camouflaging in a Complex Environment—Octopuses Use Specific Features of Their Surroundings for Background Matching. PLoS ONE, 7(5). DOI: 10.1371/journal.pone.0037579

DNA vaccines: a work in progress

2012-05-25T09:13:00Z

You are all familiar with the idea behind vaccines: an attenuated form of the pathogen stimulates the immune system to produce T-cells and antibodies specific to that particular antigen. These immune responses then become part of our T- and B-memory cells, cells that have previously encountered a certain antigen and have already specialized to recognize it. The challenge behind a vaccine is to use a form of antigen that's weak enough so not to cause the actual disease, but strong enough so to prompt the appropriate immune response. An efficient immune response has to be broad (it has to recognize all possible strains of the antigen) and strong (enough T-cells and antibodies have to be produced in order to clear the infection). First generation vaccines use the whole organism as an antigen. Unfortunately, weakened forms may still induce full infection in immunocompromised people. Second generation vaccines use portions of the organism. For example, in HIV, one protein that's been used a lot in vaccine trials is env, the envelope protein: this is the outer shell of the virus, and the part most visible to the immune system. The so called "DNA vaccines" are the third generation vaccines. The idea is to inject a circular molecule of DNA (plasmid) that encodes for the specific antigen proteins. DNA is rapidly absorbed by cells and, once inside, it can use the cell machinery to assemble the proteins it encodes for. Just like in a viral infection, these proteins are then displayed on the cell's surface and presented for recognition by the immune system. The advantage of a DNA vaccine is obvious: there is no risk that the DNA itself will trigger the actual disease. Furthermore, studies have so far shown that no anti-DNA antibodies are produced. Some DNA vaccines are already in use in veterinary medicine. In humans, though safe and well tolerated, they seem to have lower immunogenicity than other vaccines, and hence their potential hasn't been fully exploited yet. While the reason for this is still unknown, several studies have attempted to use other genes and proteins in combination with the vaccine to improve immunogenicity, in particular, genes and proteins that are involved in immune recognition pathways and cell-signaling pathways. "Advancements in antigen design, improved formulations, inclusion of molecular adjuvants, and physical methods of delivery have greatly enhanced the immunogenicity of DNA vaccines [1]." In [1] Ferraro et al. review the current studies in this field specifically for vaccines targeting influenza, human papilloma virus (HPV), and HIV. In the case of influenza, the appeal of a DNA vaccine is that it would considerably shorten the preparation time. In terms of immune responses, DNA vaccines have not been able to trigger good antibody responses, but, on the other hand, tend to perform well in triggering cellular responses (recruiting natural killer cells, T-cells, and phagocytes). In HIV in particular, both antibodies and T-cell responses are needed, both broad enough to cover the variability of the virus. Therefore, it is feasible and promising to combine a DNA vaccine with a protein one. "Combining a DNA prime and viral boost creates a synergistic enhancement in the magnitude of antigen-specific CD81 T-cell responses. A phase I trial that combined a multi-clade DNA vaccine prime with an Ad5 boost demonstrated that this strategy was capable of eliciting humoral responses in addition to cellular responses." [1] Ferraro, B., Morrow, M., Hutnick, N., Shin, T., Lucke, C., & Weiner, D. (2011). Clinical Applications of DNA Vaccines: Current Progress Clinical Infectious Diseases, 53 (3), 296-302 DOI: 10.1093/cid/cir334...

Ferraro, B., Morrow, M., Hutnick, N., Shin, T., Lucke, C., & Weiner, D. (2011) Clinical Applications of DNA Vaccines: Current Progress. Clinical Infectious Diseases, 53(3), 296-302. DOI: 10.1093/cid/cir334

When introductions go bad

2012-05-25T09:09:00Z

My first sighting of the red squirrel was in Camperdown Park in Dundee in 2003. I remember that scene vividly. I had since tried desperately to see this elusive animal again but to no avail, save a brief sighting, again in Camperdown Park, in Autumn 2010. This is because although red squirrel, which is native to UK and is protected in Europe, is outnumbered by its foreign relative, the grey squirrel that was introduced to the UK from America. Grey squirrel has several competitive advantages including its resistance to squirrel parapox virus which is fatal to the red (grey squirrels are vectors), increased fecundity, and greater ability to digest a wider variety of food. In fact, the future of the red squirrel in the British Isles is rather precarious. The Forestry Commission estimates that there there are only 140,000 red squirrels compared to over 2.5 million greys. Recently during a holiday near Lake Geneva, Switzerland, I encountered 2 red squirrels and 1 black squirrel (resembled the red squirrel with respect to the ear tufts, but with a black/grey rather than red coat). You can see a video here in Youtube: http://www.youtube.com/watch?v=g4SqcK9CME8 There is a lot of debate on how the introduction of alien species can affect the native species and tilt ecosystems, but studies indicate that certain ecosytems could be more vulnerable that others. As early as 1958, Charles Elton claimed that ecosystems with higher species diversity were less subject to invasive species as there are fewer available niches. A recent paper by Eisenhauer et al shows that species diversity could stabilise communities during invasions. It appears as if biodiversity of ecosystems provides increased resilience against onslaughts including that by foreign invaders. Caution should be exercised when foreign species are introduced. In light of these observations, a proposed law in Brazil is of importance. A recent correspondence in Nature by Vitule et al (May 2012) warns of the repecussions of a new law that, if approved, would allow farming of foreign fish species in cages. The fishes that are being considered for introduction are tilapia and carp. The authors warn that the indigenious aquatic ecosystem would be disrupted if these introduced species were to escape and would jeopardise the aquatic biodiversity which is already fragile due to human activities such as pollution and construction.References:Vitule JR (2012). Ecology: Preserve Brazil's aquatic biodiversity. Nature, 485 (7398) PMID: 22596145Eisenhauer N, Scheu S, & Jousset A (2012). Bacterial diversity stabilizes community productivity. PloS one, 7 (3) PMID: 22470577http://www.europeansquirrelinitiative.org/the_threat.htmlRed Squirrel image source: Sarah Stephen...

Vitule JR. (2012) Ecology: Preserve Brazil's aquatic biodiversity. Nature, 485(7398), 309. PMID: 22596145

Eisenhauer N, Scheu S, & Jousset A. (2012) Bacterial diversity stabilizes community productivity. PloS one, 7(3). PMID: 22470577

Cochrane and a Significantly Biased Review of Steroids for acute spinal cord injury

2012-05-25T08:00:00Z

An interesting relic of trauma care is the use of steroids for the treatment of acute spinal cord injury. As with The Golden Hour, there are people still promoting this idea. In the words of Monty Python, it’s not quite dead, yet. Who is promoting this idea? The Cochrane Collaboration. Here is a list of the papers evaluated in this 2012 update of the 2009 Cochrane Review, which was an update of the 2002 Cochrane Review. There has been no change in the references, since the most recent paper reviewed is from 2000....

Bracken MB. (2012) Steroids for acute spinal cord injury. Cochrane database of systematic reviews (Online). PMID: 22258943