As always, you should rate the articles, post notes and comments and send trackbacks when you blog about the papers. You can now also easily place articles on various social services (CiteULike, Mendeley, Connotea, Stumbleupon, Facebook and Digg) with just one click. Here are my own picks for the week – you go and look for your own favourites:
Fishery management has historically been an inexact and reactionary discipline, often taking action only after a critical stock suffers overfishing or collapse. The invertebrate ornamental fishery in the State of Florida, with increasing catches over a more diverse array of species, is poised for collapse. Current management is static and the lack of an adaptive strategy will not allow for adequate responses associated with managing this multi-species fishery. The last decade has seen aquarium hobbyists shift their display preference from fish-only tanks to miniature reef ecosystems that include many invertebrate species, creating increased demand without proper oversight. The once small ornamental fishery has become an invertebrate-dominated major industry supplying five continents. Here, we analyzed the Florida Marine Life Fishery (FLML) landing data from 1994 to 2007 for all invertebrate species. The data were organized to reflect both ecosystem purpose (in the wild) and ecosystem services (commodities) for each reported species to address the following question: Are ornamental invertebrates being exploited for their fundamental ecosystem services and economic value at the expense of reef resilience? We found that 9 million individuals were collected in 2007, 6 million of which were grazers. The number of grazers now exceeds, by two-fold, the number of specimens collected for curio and ornamental purposes altogether, representing a major categorical shift. In general, landings have increased 10-fold since 1994, though the number of licenses has been dramatically reduced. Thus, despite current management strategies, the FLML Fishery appears to be crawling to collapse.
Every year snake envenoming kills more people in the tropics than some of the world’s recognised neglected tropical diseases (NTDs), including schistosomiasis and leishmaniasis. While lacking the epidemic potential of an infectious/vector-borne disease, snake envenoming in rural tropical communities has as great a medical mortality, if not morbidity, as the NTDs. The recent categorisation of snake envenoming as an NTD is an important advance that hopefully will result in the wider recognition and allocation of resources, particularly since death from snake envenoming is preventable; antivenom is very effective when the appropriate antivenom is correctly administered. Snake envenoming urgently requires international support to instigate the epidemiological, health education, and effective treatment initiatives that proved so potent in addressing the medical burden of NTDs such as leprosy and dracunculosis. All the global estimates of snake envenoming and deaths from snakebite indicate that mortality is highest in the world’s tropical countries. Here we examined associations between the globally available data on (i) snakebite-induced mortality and (ii) socioeconomic markers of poverty. Our data unequivocally establishes that snake envenoming is globally associated with poverty, a distinctive characteristic of the neglected tropical diseases.
In most countries, tuberculosis (TB) notification is twice as high in men as in women.
Although there is clear evidence that socioeconomic and cultural factors leading to barriers in accessing health care may cause undernotification in women, particularly in developing countries, biological mechanisms may actually account for a significant part of this difference between male and female susceptibility to TB.
The role of biological gender has been determined in a number of infectious and noninfectious diseases. However, there is an absence of information on the role of biological gender in TB.
Thus, investigations should be conducted to clearly understand the role of sexual hormones, sex-related genetic background and genetic regulations, and metabolism, among other factors, in susceptibility differences between men and women.
This research may help not only to fully understand the obviously biased gender distribution among TB cases, but also to better adapt future intervention strategies at the community level. In this review, we expand on the various issues relating to TB notification and gender bias.
Amphibians are experiencing a panzootic of unprecedented proportions caused by the emergence of Batrachochytrium dendrobatidis (Bd). However, all species are not equally at risk of infection, and risk is further modified by environmental variables, specifically temperature. In order to understand how, and when, hosts mount a response to Bd we analysed infection dynamics and patterns of gene expression in the model amphibian species Silurana (Xenopus) tropicalis. Mathematical modelling of infection dynamics demonstrate the existence of a temperature-dependent protective response that is largely independent of the intrinsic growth-rate of Bd. Using temporal expression-profiling by microarrays and qRT-PCR, we characterise this response in the main amphibian lymphoid tissue, the spleen. We demonstrate that clearance of Bd at the host-optimal temperature is not clearly associated with an adaptive immune response, but rather is correlated with the induction of components of host innate immunity including the expression of genes that are associated with the production of the antimicrobial skin peptide preprocareulein (PPCP) as well as inflammatory responses. We find that adaptive immunity appears to be lacking at host-optimal temperatures. This suggests that either Bd does not stimulate, or suppresses, adaptive immunity, or that trade-offs exist between innate and adaptive limbs of the amphibian immune system. At cold temperatures, S. tropicalis loses the ability to mount a PPCP-based innate response, and instead manifests a more pronounced inflammatory reaction that is characterised by the production of proteases and higher pathogen burdens. This study demonstrates the temperature-dependency of the amphibian response to infection by Bd and indicates the influence that changing climates may exert on the ectothermic host response to pathogens.
Lawrence B. Slobodkin, a key figure in the development of the modern science of ecology, passed away on September 12, 2009, at age 81. His innovative thinking and research, provocative teaching, and visionary leadership helped transform ecology into a modern science, with deep links to evolution.
Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent “plagues”) and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900±15 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in the modern world, it is crucial that we understand past lethal outbreaks as fully as possible in order to prepare for future deadly pandemics.
Steps to facilitate inter-jurisdictional collaboration nationally and continentally have been critical for implementing and conducting coordinated wildlife rabies management programs that rely heavily on oral rabies vaccination (ORV). Formation of a national rabies management team has been pivotal for coordinated ORV programs in the United States of America. The signing of the North American Rabies Management Plan extended a collaborative framework for coordination of surveillance, control, and research in border areas among Canada, Mexico, and the US. Advances in enhanced surveillance have facilitated sampling of greater scope and intensity near ORV zones for improved rabies management decision-making in real time. The value of enhanced surveillance as a complement to public health surveillance was best illustrated in Ohio during 2007, where 19 rabies cases were detected that were critical for the formulation of focused contingency actions for controlling rabies in this strategically key area. Diverse complexities and challenges are commonplace when applying ORV to control rabies in wild meso-carnivores. Nevertheless, intervention has resulted in notable successes, including the elimination of an arctic fox (Vulpes lagopus) rabies virus variant in most of southern Ontario, Canada, with ancillary benefits of elimination extending into Quebec and the northeastern US. Progress continues with ORV toward preventing the spread and working toward elimination of a unique variant of gray fox (Urocyon cinereoargenteus) rabies in west central Texas. Elimination of rabies in coyotes (Canis latrans) through ORV contributed to the US being declared free of canine rabies in 2007. Raccoon (Procyon lotor) rabies control continues to present the greatest challenges among meso-carnivore rabies reservoirs, yet to date intervention has prevented this variant from gaining a broad geographic foothold beyond ORV zones designed to prevent its spread from the eastern US. Progress continues toward the development and testing of new bait-vaccine combinations that increase the chance for improved delivery and performance in the diverse meso-carnivore rabies reservoir complex in the US.
There is growing interest among scientists and science educators to include active learning approaches that allow students to appreciate how primary evidence is used to construct scientific knowledge ,. Indeed, the National Academies and others have recognized four essential objectives for science education at elementary, middle and high school, and undergraduate levels: (1) understanding and utilizing scientific explanations of the natural world, (2) knowing how to generate and evaluate scientific evidence, (3) understanding the nature and development of scientific knowledge, and (4) participating productively in scientific practices and discourse -. In the life sciences, both discovery-based research courses and journal clubs accomplish many of these learning goals with undergraduates -, although each has significant limitations. Hands-on research classes have proven to be a successful entry point for training new students in the process of scientific discovery, but, with the exception of bioinformatics-based classes , the heavy demand for space and resources constrains the scalability of these strategies. Journal clubs are logistically easier to run, but are only effective in small formats and are usually limited to more advanced students.
For the most part, publishing of research is a gratifying experience for journals and authors. Such publishing is predicated, above all, on trust. Authors need to trust that a journal’s reviewers and editors provide a fair review process of their papers. And of course journals need to trust authors to provide a fair, honest, and complete account of their work. Only then can readers have trust in the articles that are published.
Looking back over the past year at PLoS, as well as across the broader landscape of academic publishing, it would be hard to conclude that this trusting relationship has not been shaken rather profoundly at times. Editors have sometimes been taken unawares by ghost and guest authors, manipulation of figures, lack of authors’ willingness to share data, failure to register trials, and salami-slicing of data to produce the “least publishable unit.” From an author’s perspective–reflected in our survey of authors earlier this year, for example–the relationship may not have been as rosy as it should have been. Long decision times, hypercritical reviewers, seemingly impossible demands at the production stage, and rejection after an extended review process are always hard for authors to bear.
So in the spirit of a soon-to-be New Year we’d like to gently offer some suggestions for resolutions for all authors, reviewers, readers, and editors to ponder. We hope that no one will take offence and trust that our choices will become clear as we explain.
African cichlid fish form new species faster than any other vertebrates, with hundreds of species evolving within the last 2 million years in Lake Malawi and within the last 120,000 years in Lake Victoria. This rapid speciation makes cichlids good models for elucidating the genetic mechanisms behind biodiversity. Vision may play a key role in cichlid evolution, adapting them to forage for new foods or colonize new habitats. Vertebrate retinas have two groups of light-sensitive proteins called opsins: those in rod photoreceptors, which are sensitive to dim light, and those in cone photoreceptors, which are sensitive to color. Changes in the visual system could be due to differences either in the expression of opsin genes or in their DNA sequences. A Research Article in this issue of PLoS Biology by Christopher Hofmann and colleagues suggests that both mechanisms underlie changes in visual sensitivity in cichlids.
Experience can alter how objects are represented in the visual cortex. But experience can take different forms. It is unknown whether the kind of visual experience systematically alters the nature of visual cortical object representations. We take advantage of different training regimens found to produce qualitatively different types of perceptual expertise behaviorally in order to contrast the neural changes that follow different kinds of visual experience with the same objects. Two groups of participants went through training regimens that required either subordinate-level individuation or basic-level categorization of a set of novel, artificial objects, called “Ziggerins”. fMRI activity of a region in the right fusiform gyrus increased after individuation training and was correlated with the magnitude of configural processing of the Ziggerins observed behaviorally. In contrast, categorization training caused distributed changes, with increased activity in the medial portion of the ventral occipito-temporal cortex relative to more lateral areas. Our results demonstrate that the kind of experience with a category of objects can systematically influence how those objects are represented in visual cortex. The demands of prior learning experience therefore appear to be one factor determining the organization of activity patterns in visual cortex.
Muscle contraction is controlled by receptors in the muscle cell membranes that respond to the neurotransmitter acetylcholine when it is released from motor neurons. Acetylcholine receptors are also found on neurons, where they perform a variety of important functions, including modulating cognition and addiction. In a new study in PLoS Biology, Yishi Jin and colleagues have identified and characterized a neuronal acetylcholine receptor in the Caenorhabditis elegans that allows the tiny worm to wriggle about. The receptor regulates the balance between excitation and inhibition in muscles, and thus contributes to the coordinated contraction and relaxation of muscles on opposite sides of the body that results in locomotion.
On any given night in eastern DRC, armed groups of men will overrun a village and divide into bands of three to five, forcing themselves into houses where they seize and serially rape women and young girls. Some mutilate female genitals with guns, pieces of glass, wood, or heated plastic. Some take their victims to the forest and torture them as sex slaves for days, months, or years.
To reach Dr. Narcis Kabatereine’s office at the Vector Control Division (VCD) of Uganda’s Ministry of Health in Kampala, you must first walk through a room full of lab technicians who are studiously looking down microscopes.
The atmosphere of quiet diligence is set by the softly spoken Dr. Kabatereine (Image 1) himself, a 56-year-old entomologist, who takes great pride in having trained this cadre of hard-working technicians. When I first meet him, he shows me photos on the bulletin board behind his desk of the young technicians who have died of AIDS–a sobering reminder of the country’s death toll. “AIDS hit Uganda hard,” he says. “At one point, every night we were going to a vigil for someone who died.”
The chemical complexity of the male ejaculate is truly extraordinary and every bit as remarkable as the most extravagant male plumage and courtship displays. This protein-rich seminal fluid delivers chemical messages that can enter the female brain and modify behaviour, stimulate muscle contractions in, and change the appearance of the female reproductive tract, and cause females to release reproductive hormones. In fact, these chemicals can collectively modify almost all aspects of female reproductive behaviour and physiology.