48 research outputs found

    Twenty-first century reversal of the surface ozone seasonal cycle over the northeastern United States

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    Changing emissions can alter the surface O3 seasonal cycle, as detected from northeastern U.S. (NE) observations during recent decades. Under continued regional precursor emission controls (>80% decreases in NE NOx by 2100), the NE surface O3 seasonal cycle reverses (to a winter maximum) in 21st century transient chemistry-climate simulations. Over polluted regions, regional NOx largely controls the shape of surface O3 seasonal cycles. In the absence of regional NOx controls, climate warming contributes to a higher surface O3 summertime peak over the NE. A doubling of the global CH4 abundance by 2100 partially offsets summertime surface O3 decreases attained via NOx reductions and contributes to raising surface O3 during December–March when the O3 lifetime is longer. The similarity between surface O3 seasonal cycles over the NE and the Intermountain West by 2100 indicates a NE transition to a region representative of baseline surface O3 conditions

    Adherence measurements and corrosion resistance in primer/hot-dip galvanized steel systems

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    This paper focuses on the adherence during ageing of a primer (made of polyester resins crosslinked with melamine) applied onto hot-dip galvanized (HDG) steel for coil coating application and its influence on corrosion protection. A chromium-free surface treatment, composed of fluorotitanic acid, phosphoric acid, manganese phosphate, and vinylphenol was applied on the HDG steel to obtain high corrosion resistance and high adherence of a polyester and melamine primer. The influence of the manganese phosphate on the corrosion and adherence was investigated. To measure the adherence between the metal and the primer, a three-point flexure test was set up. The adherence was then linked with corrosion resistance during ageing, using electrochemical impedance spectroscopy

    Two Chromogranin A-Derived Peptides Induce Calcium Entry in Human Neutrophils by Calmodulin-Regulated Calcium Independent Phospholipase A2

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    Background: Antimicrobial peptides derived from the natural processing of chromogranin A (CgA) are co-secreted with catecholamines upon stimulation of chromaffin cells. Since PMNs play a central role in innate immunity, we examine responses by PMNs following stimulation by two antimicrobial CgA-derived peptides. Methodology/Principal Findings: PMNs were treated with different concentrations of CgA-derived peptides in presence of several drugs. Calcium mobilization was observed by using flow cytometry and calcium imaging experiments. Immunocytochemistry and confocal microscopy have shown the intracellular localization of the peptides. The calmodulin-binding and iPLA2 activating properties of the peptides were shown by Surface Plasmon Resonance and iPLA2 activity assays. Finally, a proteomic analysis of the material released after PMNs treatment with CgA-derived peptides was performed by using HPLC and Nano-LC MS-MS. By using flow cytometry we first observed that after 15 s, in presence of extracellular calcium, Chromofungin (CHR) or Catestatin (CAT) induce a concentration-dependent transient increase of intracellular calcium. In contrast, in absence of extra cellular calcium the peptides are unable to induce calcium depletion from the stores after 10 minutes exposure. Treatment with 2-APB (2-aminoethoxydiphenyl borate), a store operated channels (SOCs) blocker, inhibits completely the calcium entry, as shown by calcium imaging. We also showed that they activate iPLA2 as the two CaM-binding factors (W7 and CMZ) and that the two sequences can be aligned with the two CaMbinding domains reported for iPLA2. We finally analyzed by HPLC and Nano-LC MS-MS the material released by PMNs following stimulation by CHR and CAT. We characterized several factors important for inflammation and innate immunity. Conclusions/Significance: For the first time, we demonstrate that CHR and CAT, penetrate into PMNs, inducing extracellular calcium entry by a CaM-regulated iPLA2 pathway. Our study highlights the role of two CgA-derived peptides in the active communication between neuroendocrine and immune systems

    Retroviral matrix and lipids, the intimate interaction

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    Retroviruses are enveloped viruses that assemble on the inner leaflet of cellular membranes. Improving biophysical techniques has recently unveiled many molecular aspects of the interaction between the retroviral structural protein Gag and the cellular membrane lipids. This interaction is driven by the N-terminal matrix domain of the protein, which probably undergoes important structural modifications during this process, and could induce membrane lipid distribution changes as well. This review aims at describing the molecular events occurring during MA-membrane interaction, and pointing out their consequences in terms of viral assembly. The striking conservation of the matrix membrane binding mode among retroviruses indicates that this particular step is most probably a relevant target for antiviral research

    Neonatal survival interventions in humanitarian emergencies: a survey of current practices and programs.

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    BACKGROUND: Neonatal deaths account for over 40% of all deaths in children younger than five years of age and neonatal mortality rates are highest in areas affected by humanitarian emergencies. Of the ten countries with the highest neonatal mortality rates globally, six are currently or recently affected by a humanitarian emergency. Yet, little is known about newborn care in crisis settings. Understanding current policies and practices for the care of newborns used by humanitarian aid organizations will inform efforts to improve care in these challenging settings. METHODS: Between August 18 and September 25, 2009, 56 respondents that work in humanitarian emergencies completed a web-based survey either in English or French. A snow ball sampling technique was used to identify organizations that provide health services during humanitarian emergencies to gather information on current practices for maternal and newborn care in these settings. Information was collected about continuum-of-care services for maternal, newborn and child health, referral services, training and capacity development, health information systems, policies and guidelines, and organizational priorities. Data were entered into MS Excel and frequencies and percentages were calculated. RESULTS: The majority of responding organizations reported implementing components of neonatal and maternal health interventions. However, multiple barriers exist in providing comprehensive care, including: funding shortages (63.3%), gaps in training (51.0%) and staff shortages and turnover (44.9%). CONCLUSIONS: Neonatal care is provided by most of the responding humanitarian organizations; however, the quality, breadth and consistency of this care are limited

    The SWISS-2DPAGE database of two-dimensional polyacrylamide gel electrophoresis, its status in 1995.

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    SWISS-2DPAGE is a database of proteins identified on two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The current release contains 343 entries of human, yeast (Saccharomyces cerevisiae) and Escherichia coli origin, as well as virtual entries for each of the protein sequences in the SWISS-PROT database
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