G protein-coupled receptor signalling in astrocytes in health and disease: A focus on metabotropic glutamate receptors

Work published over the past 10–15 years has caused the neuroscience community to engage in a process of constant re-evaluation of the roles of glial cells in the mammalian central nervous system. Recent emerging evidence suggests that, in addition to carrying out various homeostatic functions within the CNS, astrocytes can also engage in a two-way dialogue with neurons. Astrocytes possess many of the receptors, and some of the ion channels, present in neurons endowing them with an ability to sense and respond to an array of neuronal signals. In addition, an expanding number of small molecules and proteins have been shown to be released by astrocytes in both health and disease. In this commentary we will highlight advances in our understanding of G protein-coupled receptor signalling in astrocytes, with a particular emphasis on metabotropic glutamate (mGlu) receptors. Discussion will focus on the major mGlu receptors expressed in astrocytes, mGlu3 and mGlu5, how these receptors can influence different aspects of astrocyte physiology, and how signalling by these G protein-coupled receptors might change under pathophysiological circumstances

RESPONSE OF PUBLIC LAND RANCHERS TO POLICY CHANGES

Policy analysis and planning requires that we know what the likely responses of affected parties to given policy changes. We conducted a random survey of ranchers holding 1998 public land grazing permits in all western states to determine the social and economic characteristics of permit holders, to assess their attitudes about public land policies, and to gauge their responses to three policies related to public land grazing. Respondents were asked how their operations would change due to three different levels of AUM reductions, three different grazing fee increases, and to changes in allowed season of use. The respondents were clustered into eight different types of ranchers using management objective, education, business organization, ranch size, labor, income, and financial aspects. Perceived ranching objectives included preserving family tradition, culture, and values; raising family in a rural setting; living closer to friends and family; earning a good return on investment; avoiding difficulty obtaining a job outside the ranch due to skills; protecting environmental resources; and planning to pass business on to children. Based on the clusters, different policy choices will have differential impacts depending on the type of rancher and individual management goals. Their responses to the various policy choices indicate that analysis using the refined clusters will lead to a different impact assessment compared to using average responses for the population.Agricultural and Food Policy, Land Economics/Use,

Federal Programs Available to Unemployed Workers

[Excerpt] Four groups of federal programs target unemployed workers: unemployment insurance, health care assistance, job search assistance, and training. This report presents information on federal programs targeted to unemployed workers specifically, but does not attempt to discuss means-tested programs (such as Medicaid or SSI) that are available regardless of employment status. This report will be updated with major new legislation

Robust estimates of value of a statistical life for developing economies

Environmental economists use the value-of-statistical-life (VSL) approach to value mortality changes resulting from environmental improvement. Because of scarce data, VSL estimates are unavailable for most developing countries. Using robust regression techniques, we conduct a meta-analysis of VSL studies in industrialized countries to derive a VSL prediction function for developing economies accounting for differences in risk, income, human capital levels, and other demographic characteristics of these economies. We apply our estimated VSL to assess the willingness to pay for reduction in mortality linked to air pollution in Santiago, Chile. We find willingness-to-pay estimates in the range of 1992 purchasing power parity (PPP) $519,000–675,000 per life

Genetic structure of community acquired methicillin-resistant Staphylococcus aureus USA300.

BackgroundCommunity-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a significant bacterial pathogen that poses considerable clinical and public health challenges. The majority of the CA-MRSA disease burden consists of skin and soft tissue infections (SSTI) not associated with significant morbidity; however, CA-MRSA also causes severe, invasive infections resulting in significant morbidity and mortality. The broad range of disease severity may be influenced by bacterial genetic variation.ResultsWe sequenced the complete genomes of 36 CA-MRSA clinical isolates from the predominant North American community acquired clonal type USA300 (18 SSTI and 18 severe infection-associated isolates). While all 36 isolates shared remarkable genetic similarity, we found greater overall time-dependent sequence diversity among SSTI isolates. In addition, pathway analysis of non-synonymous variations revealed increased sequence diversity in the putative virulence genes of SSTI isolates.ConclusionsHere we report the first whole genome survey of diverse clinical isolates of the USA300 lineage and describe the evolution of the pathogen over time within a defined geographic area. The results demonstrate the close relatedness of clinically independent CA-MRSA isolates, which carry implications for understanding CA-MRSA epidemiology and combating its spread

Effect of electrolyzed high-pH alkaline water on blood viscosity in healthy adults.

BACKGROUND: Previous research has shown fluid replacement beverages ingested after exercise can affect hydration biomarkers. No specific hydration marker is universally accepted as an ideal rehydration parameter following strenuous exercise. Currently, changes in body mass are used as a parameter during post-exercise hydration. Additional parameters are needed to fully appreciate and better understand rehydration following strenuous exercise. This randomized, double-blind, parallel-arm trial assessed the effect of high-pH water on four biomarkers after exercise-induced dehydration. METHODS: One hundred healthy adults (50 M/50 F, 31 ± 6 years of age) were enrolled at a single clinical research center in Camden, NJ and completed this study with no adverse events. All individuals exercised in a warm environment (30 °C, 70% relative humidity) until their weight was reduced by a normally accepted level of 2.0 ± 0.2% due to perspiration, reflecting the effects of exercise in producing mild dehydration. Participants were randomized to rehydrate with an electrolyzed, high-pH (alkaline) water or standard water of equal volume (2% body weight) and assessed for an additional 2-h recovery period following exercise in order to assess any potential variations in measured parameters. The following biomarkers were assessed at baseline and during their recovery period: blood viscosity at high and low shear rates, plasma osmolality, bioimpedance, and body mass, as well as monitoring vital signs. Furthermore, a mixed model analysis was performed for additional validation. RESULTS: After exercise-induced dehydration, consumption of the electrolyzed, high-pH water reduced high-shear viscosity by an average of 6.30% compared to 3.36% with standard purified water (p = 0.03). Other measured biomarkers (plasma osmolality, bioimpedance, and body mass change) revealed no significant difference between the two types of water for rehydration. However, a mixed model analysis validated the effect of high-pH water on high-shear viscosity when compared to standard purified water (p = 0.0213) after controlling for covariates such as age and baseline values. CONCLUSIONS: A significant difference in whole blood viscosity was detected in this study when assessing a high-pH, electrolyte water versus an acceptable standard purified water during the recovery phase following strenuous exercise-induced dehydration