Elk River Sediment Total Maximum Daily Load (TMDL) Summary and Implementation Framework and 2) Draft Basin Plan Amendment of Beneficial Uses

that you initiate the process for identifying external scientific peer reviewers for two proposed actions related to the assessment and control of sediment discharges in the Elk River watershed. These are described in the 1) Draft Upper Elk River Sediment Total Maximum Daily Load (TMDL) Summary and Implementation Framework and 2) the Draft Amendment of Beneficial Uses in Elk River, referred to herein as the TMDL Summary and Implementation Framework and the Beneficial Uses Amendment, respectively. The scientific basis for these two proposed actions is contained in the Staff Report for the Upper Elk River Sediment TMDL (Staff Report), which is the primary scientific document submitted for review. The secondary document submitted for review is Landslide Hazard in the Elk River Basin, Humboldt County, CA (Stillwater 2007)

The Phenotype-Fitness Map in Experimental Evolution of Phages

Evolutionary biologists commonly interpret adaptations of organisms by reference to a phenotype-fitness map, a model of how different states of a phenotype affect fitness. Notwithstanding the popularity of this approach, it remains difficult to directly test these mappings, both because the map often describes only a small subset of phenotypes contributing to total fitness and because direct measures of fitness are difficult to obtain and compare to the map. Both limitations can be overcome for bacterial viruses (phages) grown in the experimental condition of unlimited hosts. A complete accounting of fitness requires 3 easily measured phenotypes, and total fitness is also directly measurable for arbitrary genotypes. Yet despite the presumed transparency of this system, directly estimated fitnesses often differ from fitnesses calculated from the phenotype-fitness map. This study attempts to resolve these discrepancies, both by developing a more exact analytical phenotype-fitness map and by exploring the empirical foundations of direct fitness estimates. We derive an equation (the phenotype-fitness map) for exponential phage growth that allows an arbitrary distribution of lysis times and burst sizes. We also show that direct estimates of fitness are, in many cases, plausibly in error because the population has not attained stable age distribution and thus violates the model underlying the phenotype-fitness map. In conjunction with data provided here, the new understanding appears to resolve a discrepancy between the reported fitness of phage T7 and the substantially lower value calculated from its phenotype-fitness map

Stroke genetics: prospects for personalized medicine.

Epidemiologic evidence supports a genetic predisposition to stroke. Recent advances, primarily using the genome-wide association study approach, are transforming what we know about the genetics of multifactorial stroke, and are identifying novel stroke genes. The current findings are consistent with different stroke subtypes having different genetic architecture. These discoveries may identify novel pathways involved in stroke pathogenesis, and suggest new treatment approaches. However, the already identified genetic variants explain only a small proportion of overall stroke risk, and therefore are not currently useful in predicting risk for the individual patient. Such risk prediction may become a reality as identification of a greater number of stroke risk variants that explain the majority of genetic risk proceeds, and perhaps when information on rare variants, identified by whole-genome sequencing, is also incorporated into risk algorithms. Pharmacogenomics may offer the potential for earlier implementation of 'personalized genetic' medicine. Genetic variants affecting clopidogrel and warfarin metabolism may identify non-responders and reduce side-effects, but these approaches have not yet been widely adopted in clinical practice

Catchment-scale biogeography of riverine bacterioplankton

Lotic ecosystems such as rivers and streams are unique in that they represent a continuum of both space and time during the transition from headwaters to the river mouth. As microbes have very different controls over their ecology, distribution and dispersion compared with macrobiota, we wished to explore biogeographical patterns within a river catchment and uncover the major drivers structuring bacterioplankton communities. Water samples collected across the River Thames Basin, UK, covering the transition from headwater tributaries to the lower reaches of the main river channel were characterised using 16S rRNA gene pyrosequencing. This approach revealed an ecological succession in the bacterial community composition along the river continuum, moving from a community dominated by Bacteroidetes in the headwaters to Actinobacteria-dominated downstream. Location of the sampling point in the river network (measured as the cumulative water channel distance upstream) was found to be the most predictive spatial feature; inferring that ecological processes pertaining to temporal community succession are of prime importance in driving the assemblages of riverine bacterioplankton communities. A decrease in bacterial activity rates and an increase in the abundance of low nucleic acid bacteria relative to high nucleic acid bacteria were found to correspond with these downstream changes in community structure, suggesting corresponding functional changes. Our findings show that bacterial communities across the Thames basin exhibit an ecological succession along the river continuum, and that this is primarily driven by water residence time rather than the physiochemical status of the river

Abrasive, Silica Phytoliths and the Evolution of Thick Molar Enamel in Primates, with Implications for the Diet of Paranthropus boisei

Background: Primates—including fossil species of apes and hominins—show variation in their degree of molar enamel thickness, a trait long thought to reflect a diet of hard or tough foods. The early hominins demonstrated molar enamel thickness of moderate to extreme degrees, which suggested to most researchers that they ate hard foods obtained on or near the ground, such as nuts, seeds, tubers, and roots. We propose an alternative hypothesis—that the amount of phytoliths in foods correlates with the evolution of thick molar enamel in primates, although this effect is constrained by a species ’ degree of folivory. Methodology/Principal Findings: From a combination of dietary data and evidence for the levels of phytoliths in plant families in the literature, we calculated the percentage of plant foods rich in phytoliths in the diets of twelve extant primates with wide variation in their molar enamel thickness. Additional dietary data from the literature provided the percentage of each primate’s diet made up of plants and of leaves. A statistical analysis of these variables showed that the amount of abrasive silica phytoliths in the diets of our sample primates correlated positively with the thickness of their molar enamel, constrained by the amount of leaves in their diet (R 2 = 0.875; p,.0006). Conclusions/Significance: The need to resist abrasion from phytoliths appears to be a key selective force behind the evolution of thick molar enamel in primates. The extreme molar enamel thickness of the teeth of the East African homini

In vivo PET imaging of the neuroinflammatory response in rat spinal cord injury using the TSPO tracer [F-18]GE-180 and effect of docosahexaenoic acid

Centre for Trauma Sciences, funded by the Barts & The London Charity, GE Healthcare Ltd, the Experimental Medicine Awards from the Blizard Institute and the Imaging Centre at the Barts Cancer Institute

The genetic epidemiology of joint shape and the development of osteoarthritis

Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed

El desafío de la administración adecuada de antimicrobianos en pediatría.

Background: Antibiotics are among the drugs most commonly prescribed to children in hospitals and communities. Unfortunately, a great number of these prescriptions are unnecessary or inappropriate. Antibiotic abuse and misuse have several negative consequences, including drug-related adverse events, the emergence of multidrug resistant bacterial pathogens, the development of Clostridium difficile infection, the negative impact on microbiota, and undertreatment risks. In this paper, the principle of and strategies for paediatric antimicrobial stewardship (AS) programs, the effects of AS interventions and the common barriers to development and implementation of AS programs are discussed. Discussion: Over the last few years, there have been significant shortages in the development and availability of new antibiotics; therefore, the implementation of strategies to preserve the activity of existing antimicrobial agents has become an urgent public health priority. AS is one such approach. The need for formal AS programs in paediatrics was officially recognized only recently, considering the widespread use of antibiotics in children and the different antimicrobial resistance patterns that these subjects exhibit in comparison to adult and elderly patients. However, not all problems related to the implementation of AS programs among paediatric patients are solved. The most important remaining problems involve educating paediatricians, creating a multidisciplinary interprofessional AS team able to prepare guidelines, monitoring antibiotic prescriptions and defining corrective measures, and the availability of administrative consensuses with adequate financial support. Additionally, the problem of optimizing the duration of AS programs remains unsolved. Further studies are needed to solve the above mentioned problems. Conclusions: In paediatric patients, as in adults, the successful implementation of AS strategies has had a significant impact on reducing targeted- and nontargeted-antimicrobial use by improving the quality of care for hospitalized patients and preventing the emergence of resistance. Considering that rationalization of antibiotic misuse and abuse is the basis for reducing emergence of bacterial resistance and several clinical problems, all efforts must be made to develop multidisciplinary paediatric AS programs in hospital and community settings