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To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 µm (PM2.5) in the US, we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use, and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We developed air quality simulations using the Community Multiscale Air Quality Model (CMAQ) chemical transport model for two nested domains with 220 and 36 km horizontal grid cell resolution for a semi-hemispheric domain and a continental United States (US) domain, respectively. The semi-hemispheric domain was used to evaluate the impact of projected Asian emissions changes on US air quality. WRF meteorological fields were used to calculate current (2000s) and future (2050s) biogenic emissions using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). For the semi-hemispheric domain CMAQ simulations, present-day global emissions inventories were used and projected to the 2050s based on the IPCC A1B scenario. Regional anthropogenic emissions were obtained from the US Environmental Protection Agency National Emission Inventory 2002 (EPA NEI2002) and projected to the future using the MARKet ALlocation (MARKAL) energy system model assuming a business as usual scenario that extends current decade emission regulations through 2050. Our results suggest that daily maximum 8h average ozone (DM8O) concentrations will increase in a range between 2 to 12ppb across most of the continental US, with the highest increase in the South, Central, and Midwest regions of the US, due to increases in temperature, enhanced biogenic emissions, and changes in land use. The effects of these factors are only partially offset by reductions in DM8O associated with decreasing US anthropogenic emissions. Increases in PM2.5 levels between 2 and 4 µg m-3 in the Northeast, Southeast, and South regions are mostly a result of enhanced biogenic emissions and land use changes. Little change in PM2.5 in the Central, Northwest, and Southwest regions was found, even when PM precursors are reduced with regulatory curtailment. Changes in temperature, relative humidity, and boundary conditions shift the composition but do not alter overall PM2.5 mass concentrations. [ABSTRACT FROM AUTHOR]

The CMAQ model in combination with observations for INTEX-NA/ICARTT 2004 are used to evaluate recent advances in isoprene oxidation chemistry and provide constraints on isoprene nitrate yields, isoprene nitrate lifetimes, and NOx recycling rates. We incorporate recent advances in isoprene oxidation chemistry into the SAPRC-07 chemical mechanism within the US EPA Community Multiscale Air Quality (CMAQ) model. The results show improved model performance for a range of species compared against aircraft observations from the INTEX-NA/ICARTT 2004 field campaign. We further investigate the key processes in isoprene nitrate chemistry and evaluate the impact of uncertainties in the isoprene nitrate yield, NOx (NOx =NO+NO2) recycling efficiency, dry deposition velocity, and RO2 +HO2 reaction rates. We focus our examination in the Southeastern United States, which is impacted by both abundant isoprene emissions and high levels of anthropogenic pollutants. We find that NOx concentrations increase by 4-9% as a result of reduced removal by isoprene nitrate chemistry. O3 increases by 2 ppbv as a result of changes in NOx. OH concentrations increase by 30%, which can be primarily attributed to greater HOx production. We find that the model can capture observed total alkyl and multifunctional nitrates ( ΣANs) and their relationship with O3, by assuming either an isoprene nitrate yield of 6% and daytime lifetime of 6 h or a yield of 12% and lifetime of 4 h. Uncertainties in the isoprene nitrates can impact ozone production by 10% and OH concentrations by 6%. The uncertainties in NOx recycling efficiency appear to have larger effects than uncertainties in isoprene nitrate yield and dry deposition velocity. Further progress depends on improved understanding of isoprene oxidation pathways, the rate of NOx recycling from isoprene nitrates, and the fate of the secondary, tertiary, and further oxidation products of isoprene. [ABSTRACT FROM AUTHOR]

The thalamus comprises numerous nuclei that can be grouped into five major functional domains: (1) the reticular and intralaminar nuclei influence arousal and nociception, (2) sensory nuclei handle afferent pathways, (3) the effector nuclei are involved in motor function and language, (4) associative nuclei participate in higher cognitive functions and (5) limbic nuclei influence mood and motivation. The thalamic nuclei are mainly supplied by the following four cerebral arteries: paramedian artery, anterior thalamoperforating artery, thalamogeniculate artery and posterior choroidal artery (lateral branches). Occlusions of these arteries affect the thalamic nuclei to varying degrees and produce partly characteristic and partly overlapping deficits. This article describes the clinical pictures. [ABSTRACT FROM AUTHOR]

The article discusses a research study which introduces the Market Allocation (MARKAL) method for anthropogenic emission scenarios. The said approach focuses on energy use and production because these factors are the main sources of air pollution and uses two emission scenarios. Findings reveal that both scenarios demonstrate significant reductions in air pollutant emissions.

In Haiti, >90% of the population descended from African slaves. Of 7,147 Haitian pregnant women sampled, 44% of hepatitis B virus (HBV) infections were caused by genotype A1, which today is found mainly in eastern Africa. Twenty percent belong to a rare subgenotype, A5, which has been found only in the former Bight of Benin, a former primary slave trading post. Haitian A subgenotypes appear to have separated early from the African subgenotypes; the most prevalent genotype and subgenotype in West Africa today (E and A3, respectively) are rare in Haiti. This difference indicates that the dominant subgenotypes in Africa emerged in the general population only after the slave trade and explains the low genetic diversity of genotype E. The high prevalence of HBV genotype E in much of Africa further suggests that HBV hyperendemicity is a recent phenomenon, probably resulting from extensive use of unsafe needles. [ABSTRACT FROM AUTHOR]

A phosphorus (P) greenhouse experiment was carried out with maize (Zea Mays L.) using surface horizons of three contrasted acid soils from southern Cameroon. The objectives were (i) to assess causal factors of maize differential growth and P uptake and (ii) to explore plant-soil interactions in acid soils under increasing P supply. Shoot and root dry-matter yield and P uptake were significantly influenced by soil type and P rate (P<0.000), but the interaction was not significant. Soil properties that significantly (P<0.05) influenced maize growth variables were available P, soil pH, exchangeable bases [calcium (Ca), magnesium (Mg)], and exchangeable aluminium (Al). Data ordination through principal-component analysis highlighted a four-component model that accounted for 88.1% of total system variance (TSV) and summarized plant reaction in acid soil condition. The first component, associated with 36.1% of TSV, pointed at increasing root-shoot ratio with increasing soil acidity and exchangeable Al. The second component (24.6% of TSV) highlighted soil labile P pool increase as a function of P rate. The third and fourth components reflected nitrogen (N) accumulation in soils and soil texture variability, respectively. [ABSTRACT FROM AUTHOR]

Adherence to fluid restrictions and dietary and medication guidelines as well as attendance at prescribed hemodialysis sessions of a hemodialysis regimen are essential for adequate management of end-stage renal disease. A literature review was conducted to determine the prevalence and consequences of nonadherence to the different aspects of a hemodialysis regimen and the methodological obstacles in research on nonadherence. Nonadherence to the prescribed regimen is a common problem in hemodialysis and is associated with increased morbidity and mortality. Research on nonadherence is associated with 2 major obstacles: inconsistencies in definitions and invalid measurement methods. Further research is needed to validate measurement methods and to establish clinically relevant operational definitions of nonadherence. [ABSTRACT FROM AUTHOR]

Microglial cells are thought to serve as sensors for pathologic events in the brain. In the present study we demonstrate that these cells respond with an increase in intracellular calcium concentration ([Ca2+]i) to intracellular alkaline shifts induced by either application of NH3/NH4+ or by an extracellular alkaline shift. The cytoplasmic pH (pHi) and [Ca2+]i in cultured mouse microglial cells were studied employing the fluorescent probes BCECF and fura-2, respectively. Application of NH3/NH4+ caused an initial rapid alkalinization followed by a slow recovery towards the resting level, while application of alkaline (pH 8.2) solution triggered a slower rise in pHi. The [Ca2+]i elevation triggered by NH3/NH4+ and extracellular alkaline shift were caused by different mechanisms: extracellular alkalinization induced a transmembrane Ca2+ entry, whereas NH3/NH4+ triggered Ca2+ release from thapsigargin- and ATP-sensitive intracellular pools. The mobilization of intracellular Ca2+ caused by NH3/NH4+ was blocked by a specific inhibitor of phospholipase C, U-73122, but was not affected by an inhibitor of G-protein, pertussis toxin. This implies that NH3/NH4 interacts with phospholipase C and leads to an increase in the intracellular level of inositol 1,4,5-trisphosphate (InsP3). In contrast to a previous study using a microglial cell line, application of NH3/NH4+ did not result in a release of tumor necrosis factor α (TNF-α), a marker of microglial activation, in the primary microglial cells. This implies that ammonium does not lead to activation of microglia in the culture model. [ABSTRACT FROM AUTHOR]

Investigates whether endothelium-derived relaxing factor/nitric oxide (EDRF/NO) and prostaglandin I2 affected vasodilator-stimulated protein phosphorylation in washed human platelets injected in the coronaries of saline-perfused rabbit hearts. Effect of endothelial stimulator acetylcholine; Inhibition of EDRF/NO synthesis by NG-nitro-L-arginine.

The stratum corneum of human skin is responsible for maintaining the epidermal permeability barrier. We have developed a bilayered skin culture (SC) which forms a corneum 35 ± 1 cell layers thick 21 days after being raised to the air-liquid (A/L) interface. By the 7th day after raising to the A/L interface the corneocytes were irregularly shaped and had cross-sectional areas (CSA) of ≧300 Μm. By the 21st day the corneocytes had assumed polygonal shapes and had a CSA (100-250 Μm) similar to that of human foreskin. The total lipid (TL) content of the corneum averaged 5-7% of the lyophilized weight. Ceramide content increased from 20% of TL at day 7 of A/L interface culture to 30% at day 21. Triglycerides decreased from 43% to 17% of TL during the same period. Free fatty acids comprised 5.5% of TL at day 21 of A/L interface culture. The intercorneocyte spaces contained stacks of lipid lamellae. However, the stacks lacked the Landmann unit repeat. Abnormal lamellar structures were observed in both the intra- and extracorneocyte spaces. Transepidermal water loss (TEWL) was >4 mg/cm per h throughout the culture period. Lipid supplementation of the culture medium and culturing in a low humidity environment improved barrier function by 50%. However, the effects were not additive. The SC developed a near-normal corneum, but did not achieve barrier competence, due at least partially to abnormalities in lipid composition and organization. Improvement of barrier function with lipid supplementation or low humidity indicates that modifications of the culture environment may facilitate the SC in assembling a permeability barrier equivalent to human skin. [ABSTRACT FROM AUTHOR]

The Kalman duality between the reachability and observability of finite-dimensional linear systems is generalized to adjoint systems (in the sense of Arbib-Manes). The theory includes previous results on infinite-dimensional linear systems and linear systems over rings, and yields new results for classes of nonlinear systems such as bilinear and polynomial systems. [ABSTRACT FROM AUTHOR]

This paper provides a synthesis of results that have emerged from recent modeling studies of the potential sensitivity of U.S. regional ozone (O3) concentrations to global climate change (ca. 2050). This research has been carried out under the auspices of an ongoing U.S. Environmental Protection Agency (EPA) assessment effort to increase scientific understanding of the multiple complex interactions among climate, emissions, atmospheric chemistry, and air quality. The ultimate goal is to enhance the ability of air quality managers to consider global change in their decisions through improved characterization of the potential effects of global change on air quality, including O3. The results discussed here are interim, representing the first phase of the EPA assessment. The aim in this first phase was to consider the effects of climate change alone on air quality, without accompanying changes in anthropogenic emissions of precursor pollutants. Across all of the modeling experiments carried out by the different groups, simulated global climate change causes increases of a few to several parts per billion (ppb) in summertime mean maximum daily 8-h average O3 concentrations over substantial regions of the country. The different modeling experiments in general do not, however, simulate the same regional patterns of change. These differences seem to result largely from variations in the simulated patterns of changes in key meteorological drivers, such as temperature and surface insolation. How isoprene nitrate chemistry is represented in the different modeling systems is an additional critical factor in the simulated O3 response to climate change., Engineering and Applied Sciences

Background: Currently, stroke patients with unknown time of symptom onset (UTOS) are excluded from therapy with intravenous tissue Plasminogen Activator. We hypothesized that MRI-based intravenous thrombolysis is safe in UTOS. Methods: We analyzed radiological and clinical data as well as outcomes of stroke patients (including UTOS) who received intravenous thrombolytic therapy after MRI. Results: Compared to patients with known time of symptom onset ( n = 131), UTOS ( n = 17) were older (81, 71-88 vs. 75 years, 66-82, P = 0.03), had a longer median time between last-seen-well and thrombolysis (12.3 h, IQR 11.5-15.2 h vs. 2.1 h, 1.8-2.8 h, P < 0.01), had a longer median door-to-needle time (86 min, 49-112 vs. 60 min, 49-76, P = 0.02), and a higher rate of arterial obstruction on MR-angiography (82.4% vs. 56.5%, P = 0.04). No symptomatic intracerebral hemorrhage occurred in UTOS. After 3 months, there was no significant difference between groups concerning good functional outcome (modified Rankin Scale 0-2; 35.3% vs. 49.6%, P = 0.26) or mortality (0% vs. 15.3%, P = 0.08). In multivariate analyses including age, gender, baseline NIHSS, and atrial fibrillation UTOS did not have an independent effect on good functional outcome after 3 months (OR 1.16; 0.32-4.12, P = 0.81). Conclusions: Thrombolysis after MRI seems safe and effective in UTOS. This observation may encourage those who plan prospective placebo-controlled trials of thrombolytics in this subgroup of stroke patients. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article related to takotsubo cardiomyopathy after ischemic stroke.