205 research outputs found
Exocytosis from permeabilized bovine adrenal chromaffin cells is differently modulated by guanosine 5'-[gamma-thio]triphosphate and guanosine 5'-[beta gamma-imido]triphosphate
1. In bovine adrenal chromaffin cells made permeable either to molecules less than or equal to 3 kDa with alphatoxin or to proteins less than or equal to 150 kDa with streptolysin O, the GTP analogues guanosine 5'-[beta gamma-imido]triphosphate (p[NH]ppG) and guanosine 5'-[gamma-thio]triphosphate (GTP[S]) differently modulated Ca(2+)-stimulated exocytosis. 2. In alphatoxin-permeabilized cells, p[NH]ppG up to 20 microM activated Ca(2+)-stimulated exocytosis. Higher concentrations had little or no effect. At a free Ca2+ concentration of 5 microM, 7 microM-p[NH]ppG stimulated exocytosis 6-fold. Increasing the free Ca2+ concentration reduced the effect of p[NH]ppG. Pretreatment of the cells with pertussis toxin prevented the activation of the Ca(2+)-stimulated exocytosis by p[NH]ppG. 3. In streptolysin O-permeabilized cells, p[NH]ppG did not activate, but rather inhibited Ca(2+)-dependent catecholamine release under all conditions studied. In the soluble cytoplasmic material that escaped during permeabilization with streptolysin O, different G-protein alpha-subunits were detected using an appropriate antibody. Around 15% of the cellular alpha-subunits were detected in the supernatant of permeabilized control cells. p[NH]ppG or GTP[S] stimulated the release of alpha-subunits 2-fold, causing a loss of about 30% of the cellular G-protein alpha-subunits under these conditions. Two of the alpha-subunits in the supernatant belonged to the G(o) type, as revealed by an antibody specific for G(o) alpha. 4. GTP[S], when present alone during stimulation with Ca2+, activated exocytosis in a similar manner to p[NH]ppG. Upon prolonged incubation, GTP[S], in contrast to p[NH]ppG, inhibited Ca(2+)-induced exocytosis from cells permeabilized by either of the pore-forming toxins. This effect was resistant to pertussin toxin. 5. The p[NH]ppG-induced activation of Ca(2+)-stimulated release from alphatoxin-permeabilized chromaffin cells may be attributed to one of the heterotrimeric G-proteins lost during permeabilization with streptolysin O. The inhibitory effect of GTP[S] on exocytosis is apparently not mediated by G-protein alpha-subunits, but by another GTP-dependent process still occurring after permeabilization with streptolysin O
Alternative fuels from forest residues for passenger cars - an assessment under German framework conditions
Background
Due to the available volumes, biogenic residues are a promising resource for renewable fuels for passenger cars to reduce greenhouse gas (GHG) emissions. In this study, we compare three fuels from forest residues under German framework conditions: biogenic electricity, substitute natural gas (SNG), and Fischer-Tropsch (FT) diesel.
Methods
Fuels from forest residues are compared with regard to their technical efficiency (here defined as ‘pkm per kg biomass’), costs, and environmental impacts with a focus on GHG emissions. We took into consideration the real-life driving conditions and corresponding car classes as well as market penetration scenarios for electric and gaseous fuel cars.
Results
Our results show that the technical efficiency of biogenic electricity is high, while the economic and environmental results strongly depend on the car size and market penetration assumptions. Furthermore, it is essential to clearly define the main goal of introducing fuels from forest residues. If the goal is to reduce GHG emissions at the lowest cost, SNG (and natural gas) in bigger cars is preferable. For high GHG reductions at the lowest forest residue consumption, biogenic electricity in smaller commuter-type cars are found to be a good solution. This also proves true for the aggregated environmental impact score ReCiPe Total.
Conclusions
It is important to include mobility patterns and a clear goal definition when comparing biogenic fuels. In Germany, biogenic electricity, SNG, and FT diesel can reduce GHG emissions at reduction costs of around 100 €/t CO2-Eq when used the right way
Comparison of NITAG policies and working processes in selected developed countries
BACKGROUND: Vaccines are specific medicines characterized by two country-specific market access processes: (1) a recommendation by National Immunization Technical Advisory Group (NITAG), and (2) a funding policy decision. OBJECTIVES: The objective of this study was to compare and analyze NITAGs of 13 developed countries by describing vaccination committees' bodies and working processes. METHODS: Information about NITAGs bodies and working processes was searched from official sources from June 2011 to November 2012. Retrieved information was completed from relevant articles identified through a systematic literature review and by information provided by direct contact with NITAGs or parent organizations. An expert panel was also conducted to discuss, validate, and provide additional input on obtained results. RESULTS: While complete information, defined as 100%, was retrieved only for the UK, at least 80% of data was retrieved for 9 countries out of the 13 selected countries. Terms of references were identified in 7 countries, and the main mission for all NITAGs was to provide advice for National immunization programs. However, these terms of references did not fully encompass all the actual missions of the NITAGs. Decision analysis frameworks were identified for 10 out of the 13, and all NITAGs considered at least four criteria for decision-making: disease burden, efficacy/effectiveness, safety and cost-effectiveness. Advices were published by most NITAGs, but few NITAGs published meeting agendas and minutes. Only the United States had open meetings. CONCLUSIONS: This study supports previous findings about the disparities in NITAGs processes which could potentially explain the disparity in access to vaccinations and immunization programs across Europe. With NITAGs recommendations being used by policy decision makers for implementation and funding of vaccine programs, guidances should be well-informed and transparent to ensure National Immunization Programs' (NIP) credibility among the public and health care professionals
A guided tour of asynchronous cellular automata
Research on asynchronous cellular automata has received a great amount of
attention these last years and has turned to a thriving field. We survey the
recent research that has been carried out on this topic and present a wide
state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat
Functional response of soil microbial communities to tillage, cover crops and nitrogen fertilization
© 2016 Elsevier B.V.Agricultural practices such as tillage, cover crops, and nitrogen (N) fertilization affect physico-chemical and biological soil parameters. However, these factors were often studied separately and their combined effects remain unclear, especially with respect to soil microbial functional diversity and carbon (C) and N content. Thereafter, we aim to assess the links between cropping systems and functional response of microbial communities by using a large range of soil chemical and biological measurements. A 5-yr field experiment was conducted in Northern France using a combination of three factors: i) no-till (NT) vs. conventional tillage (CT); ii) with or without winter cover crops (bare fallow; cover crops with a low prevalence of legumes; cover crop with a high prevalence of legumes); and iii) with or without N fertilization. C and N inputs from cover crops and crop residues, C and N content, enzyme activities, and microbial functional diversity in the topsoil (0–10 cm) were measured over an industrial crop rotation: wheat, pea, corn, wheat, flax. No-till combined with any of the cover crops was characterized by increased total soil organic C and N contents by more than 20% between 2010 and 2015. Dehydrogenase and urease activities were significantly greatest under NT, irrespective of the presence of cover crops. Cover crops without N fertilization under no-till led to higher microbial functional activity (faster carbohydrate and phenolic compound degradation) and diversity. Bare fallow had lower soil microbial functional diversity and C and N contents compared with soil under NT and cover crops. On the other hand, NT associated with cover crops allowed to maintain the soil in both C and N, and to promote microbial activities without N fertilization. In conclusion, winter cover crops and/or NT are sustainable agricultural practices resulting in a greater soil quality index. These results demonstrate that NT and use of standard cover crops or cover crops with legumes for 5 years under a low biomass return in industrial crop production have a positive effect on: i) upper soil C content and microbial enzymes, irrespective of N fertilization regime; ii) soil microbial functional diversity in the absence of N fertilization
Aseptic Meningitis in Children: Analysis of 506 Cases
BACKGROUND: Non-polio human enteroviruses are the leading cause of aseptic meningitis in children. The role of enterovirus PCR for diagnosis and management of aseptic meningitis has not been fully explored. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective study was conducted to determine the epidemiological, clinical, and laboratory characteristics of aseptic meningitis and to evaluate the role of enterovirus PCR for the diagnosis and management of this clinical entity. The medical records of children who had as discharge diagnosis aseptic or viral meningitis were reviewed. A total of 506 children, median age 5 years, were identified. The annual incidence rate was estimated to be 17/100,000 children less than 14 years of age. Most of the cases occurred during summer (38%) and autumn (24%). The dominant clinical symptoms were fever (98%), headache (94%) and vomiting (67%). Neck stiffness was noted in 60%, and irritation in 46% of the patients. The median number of CSF cell count was 201/mm(3) with polymorphonuclear predominance (>50%) in 58.3% of the cases. Enterovirus RNA was detected in CSF in 47 of 96 (48.9%) children tested. Children with positive enterovirus PCR had shorter hospitalization stay as compared to children who had negative PCR or to children who were not tested (P = 0.01). There were no serious complications or deaths. CONCLUSIONS: Enteroviruses accounted for approximately one half of cases of aseptic meningitis. PCR may reduce the length of hospitalization and plays important role in the diagnosis and management of children with aseptic meningitis
De novo variants in ATXN7L3 lead to developmental delay, hypotonia and distinctive facial features
Deubiquitination is critical for the proper functioning of numerous biological pathways such as DNA repair, cell cycle progression, transcription, signal transduction, and autophagy. Accordingly, pathogenic variants in deubiquitinating enzymes (DUBs) have been implicated in neurodevelopmental disorders (ND) and congenital abnormalities. ATXN7L3 is a component of the DUB module of the SAGA complex, and two other related DUB modules, and serves as an obligate adaptor protein of 3 ubiquitin-specific proteases (USP22, USP27X or USP51).
Through exome sequencing and GeneMatching, we identified nine individuals with heterozygous variants in ATXN7L3. The core phenotype included global motor and language developmental delay, hypotonia, and distinctive facial characteristics including hypertelorism, epicanthal folds, blepharoptosis, a small nose and mouth, and low-set posteriorly rotated ears.
In order to assess pathogenicity, we investigated the effects of a recurrent nonsense variant [c.340C>T; p.(Arg114Ter)] in fibroblasts of an affected individual. ATXN7L3 protein levels were reduced, and deubiquitylation was impaired, as indicated by an increase in histone H2Bub1 levels.
This is consistent with the previous observation of increased H2Bub1 levels in Atxn7l3-null mouse embryos, which have developmental delay and embryonic lethality. In conclusion, we present clinical information and biochemical characterization supporting ATXN7L3 variants in the pathogenesis of a rare syndromic ND
Effects of experimental warming at the microhabitat scale on oak leaf traits and insect herbivory across a contrasting environmental gradient
10 páginas, 3 figuras, 2 tablasForest microclimatic variation can result in substantial temperature differences at local scales with concomitant impacts on plant defences and herbivory. Such microclimatic effects, however, may differ across abiotically contrasting sites depending on background environmental differences. To test these cross-scale effects shaping species ecological and evolutionary responses, we experimentally tested the effects of aboveground microhabitat warming on insect leaf herbivory and leaf defences (toughness, phenolic compounds) for saplings of sessile oak Quercus petraea across two abiotically contrasting sites spanning 9° latitude. We found higher levels of herbivory at the low-latitude site, but leaf traits showed mixed patterns across sites. Toughness and condensed tannins were higher at the high-latitude site, whereas hydrolysable tannins and hydroxycinnamic acids were higher at the low-latitude site. At the microhabitat scale, experimental warming increased herbivory, but did not affect any of the measured leaf traits. Condensed tannins were negatively correlated with herbivory, suggesting that they drive variation in leaf damage at both scales. Moreover, the effects of microhabitat warming on herbivory and leaf traits were consistent across sites, i.e. effects at the microhabitat scale play out similarly despite variation in factors acting at broader scales. These findings together suggest that herbivory responds to both microhabitat (warming) and broad-scale environmental factors, whereas leaf traits appear to respond more to environmental factors operating at broad scales (e.g. macroclimatic factors) than to warming at the microhabitat scale. In turn, leaf secondary chemistry (tannins) appears to drive both broad-scale and microhabitat-scale variation in herbivory. Further studies are needed using reciprocal transplants with more populations across a greater number of sites to tease apart plant plasticity from genetic differences contributing to leaf trait and associated herbivory responses across scales and, in doing so, better understand the potential for dynamics such as local adaptation and range expansion or contraction under shifting climatic regimes.This work was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (ERC Starting Grant FORMICA 757833, 2018, www.formica.ugent.be) to PDF, CM, KDP and PS, a grant from the Spanish National Research Council (2021AEP082) to XM, and a grant from the Regional Government of Galicia (IN607A 2021/03) to XM.Peer reviewe
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