77 research outputs found
\u3ci\u3eChlorella\u3c/i\u3e Viruses Evoke a Rapid Release of K\u3csup\u3e+\u3c/sup\u3e from Host Cells During the Early Phase of Infection
Infection of Chlorella NC64A cells by PBCV-1 produces a rapid depolarization of the host probably by incorporation of a viral-encoded K+ channel (Kcv) into the host membrane. To examine the effect of an elevated conductance, we monitored the virus-stimulated efflux of K+ from the Chlorella cells. The results indicate that all 8 Chlorella viruses tested evoked a host specific K+ efflux with a concomitant decrease in the intracellular K+. This K+ efflux is partially reduced by blockers of the Kcv channel. Qualitatively these results support the hypothesis that depolarization and K+ efflux are at least partially mediated by Kcv. The virus-triggered K+ efflux occurs in the same time frame as host cell wall degradation and ejection of viral DNA. Therefore, it is reasonable to postulate that loss of K+ and associated water fluxes from the host lower the pressure barrier to aid ejection of DNA from the virus particles into the host
Digital support of narrative writing skills for students with special educational needs. A systematic review
Die Fähigkeit, Gedanken schriftlich festzuhalten, ist für gesellschaftliche Teilhabe unabdingbar. Viele Schülerinnen und Schüler erwerben diese Kompetenz jedoch nicht in ausreichendem Maße und benötigen deswegen eine zusätzliche spezifische Förderung. Vor dem Hintergrund einer zunehmenden Bedeutung der Digitalisierung im Bildungsbereich stellt sich die Frage, welche wissenschaftlichen Erkenntnisse bezüglich digitaler Schreibinterventionen bei Schülerinnen und Schülern mit unterschiedlichen diagnostizierten Unterstützungsbedarfen existieren. Das vorliegende systematische Literatur-Review gibt einen Überblick über den gegenwärtigen internationalen Forschungsstand. Insgesamt wurden 40 Zeitschriftenartikel und 11 Dissertationen in die Beurteilung einbezogen. Es zeigt sich, dass digitale Förderung unabhängig vom Förderbedarf, vom Alter und von der Schulform dazu beitragen kann, die narrative Schreibkompetenz zu verbessern. Eine Zuordnung der genutzten digitalen Elemente anhand des SAMR-Modells (Puentedura, 2006) gibt einen Hinweis darauf, dass diese hauptsächlich die analogen Elemente ersetzen und erweitern und weniger der Umgestaltung der Aufgaben zuzuordnen sind. Trotz der Vielzahl an einschlägigen empirischen Arbeiten ist die Datenbasis im Hinblick auf hochwertige Studien allerdings noch zu gering, um verlässliche und allgemeingültige Aussagen über die Wirkungen treffen zu können. (DIPF/Orig.)The ability to capture thoughts in a written form is essential for social participation. However, many students develop this skill insufficiently and therefore require additional specific support. Digitalization in education is gaining in importance. The question therefore arises which scientific findings exist regarding digital writing interventions for students with different diagnosed educational needs. This systematic literature review provides an overview of the current state of international research. A total of 40 journal articles and 11 dissertations were included in the review. It is found that digital support is able to improve narrative writing skills regardless of diagnosed educational need, age, and school type. A categorization of the digital elements used based on the SAMR model (Puentedura, 2006) indicates that they mainly substitute and augment the analog elements and are less associated with modification and redefinition. However, despite the large amount of relevant empirical works, the data base in terms of high-quality studies is still too small to draw reliable and generalizable conclusions about the effects. (DIPF/Orig.
Additive fiber-cerclages in proximal humeral fractures stabilized by locking plates: No effect on fracture stabilization and rotator cuff function in human shoulder specimens
Background and purpose The effect of additive fiber-cerclages in proximal humeral fractures stabilized by locking plates on fracture stabilization and rotator cuff function is unclear. Here it was assessed in a human cadaver study
Common characteristics of open source software development and applicability for drug discovery: a systematic review
<p>Abstract</p> <p>Background</p> <p>Innovation through an open source model has proven to be successful for software development. This success has led many to speculate if open source can be applied to other industries with similar success. We attempt to provide an understanding of open source software development characteristics for researchers, business leaders and government officials who may be interested in utilizing open source innovation in other contexts and with an emphasis on drug discovery.</p> <p>Methods</p> <p>A systematic review was performed by searching relevant, multidisciplinary databases to extract empirical research regarding the common characteristics and barriers of initiating and maintaining an open source software development project.</p> <p>Results</p> <p>Common characteristics to open source software development pertinent to open source drug discovery were extracted. The characteristics were then grouped into the areas of participant attraction, management of volunteers, control mechanisms, legal framework and physical constraints. Lastly, their applicability to drug discovery was examined.</p> <p>Conclusions</p> <p>We believe that the open source model is viable for drug discovery, although it is unlikely that it will exactly follow the form used in software development. Hybrids will likely develop that suit the unique characteristics of drug discovery. We suggest potential motivations for organizations to join an open source drug discovery project. We also examine specific differences between software and medicines, specifically how the need for laboratories and physical goods will impact the model as well as the effect of patents.</p
Long-term exposure to low-level air pollution and incidence of chronic obstructive pulmonary disease: The ELAPSE project.
BACKGROUND: Air pollution has been suggested as a risk factor for chronic obstructive pulmonary disease (COPD), but evidence is sparse and inconsistent. OBJECTIVES: We examined the association between long-term exposure to low-level air pollution and COPD incidence. METHODS: Within the 'Effects of Low-Level Air Pollution: A Study in Europe' (ELAPSE) study, we pooled data from three cohorts, from Denmark and Sweden, with information on COPD hospital discharge diagnoses. Hybrid land use regression models were used to estimate annual mean concentrations of particulate matter with a diameter < 2.5 µm (PM2.5), nitrogen dioxide (NO2), and black carbon (BC) in 2010 at participants' baseline residential addresses, which were analysed in relation to COPD incidence using Cox proportional hazards models. RESULTS: Of 98,058 participants, 4,928 developed COPD during 16.6 years mean follow-up. The adjusted hazard ratios (HRs) and 95% confidence intervals for associations with COPD incidence were 1.17 (1.06, 1.29) per 5 µg/m3 for PM2.5, 1.11 (1.06, 1.16) per 10 µg/m3 for NO2, and 1.11 (1.06, 1.15) per 0.5 10-5m-1 for BC. Associations persisted in subset participants with PM2.5 or NO2 levels below current EU and US limit values and WHO guidelines, with no evidence for a threshold. HRs for NO2 and BC remained unchanged in two-pollutant models with PM2.5, whereas the HR for PM2.5 was attenuated to unity with NO2 or BC. CONCLUSIONS: Long-term exposure to low-level air pollution is associated with the development of COPD, even below current EU and US limit values and possibly WHO guidelines. Traffic-related pollutants NO2 and BC may be the most relevant
Long-term low-level ambient air pollution exposure and risk of lung cancer - A pooled analysis of 7 European cohorts.
BACKGROUND/AIM: Ambient air pollution has been associated with lung cancer, but the shape of the exposure-response function - especially at low exposure levels - is not well described. The aim of this study was to address the relationship between long-term low-level air pollution exposure and lung cancer incidence. METHODS: The "Effects of Low-level Air Pollution: a Study in Europe" (ELAPSE) collaboration pools seven cohorts from across Europe. We developed hybrid models combining air pollution monitoring, land use data, satellite observations, and dispersion model estimates for nitrogen dioxide (NO2), fine particulate matter (PM2.5), black carbon (BC), and ozone (O3) to assign exposure to cohort participants' residential addresses in 100 m by 100 m grids. We applied stratified Cox proportional hazards models, adjusting for potential confounders (age, sex, calendar year, marital status, smoking, body mass index, employment status, and neighborhood-level socio-economic status). We fitted linear models, linear models in subsets, Shape-Constrained Health Impact Functions (SCHIF), and natural cubic spline models to assess the shape of the association between air pollution and lung cancer at concentrations below existing standards and guidelines. RESULTS: The analyses included 307,550 cohort participants. During a mean follow-up of 18.1 years, 3956 incident lung cancer cases occurred. Median (Q1, Q3) annual (2010) exposure levels of NO2, PM2.5, BC and O3 (warm season) were 24.2 µg/m3 (19.5, 29.7), 15.4 µg/m3 (12.8, 17.3), 1.6 10-5m-1 (1.3, 1.8), and 86.6 µg/m3 (78.5, 92.9), respectively. We observed a higher risk for lung cancer with higher exposure to PM2.5 (HR: 1.13, 95% CI: 1.05, 1.23 per 5 µg/m3). This association was robust to adjustment for other pollutants. The SCHIF, spline and subset analyses suggested a linear or supra-linear association with no evidence of a threshold. In subset analyses, risk estimates were clearly elevated for the subset of subjects with exposure below the EU limit value of 25 µg/m3. We did not observe associations between NO2, BC or O3 and lung cancer incidence. CONCLUSIONS: Long-term ambient PM2.5 exposure is associated with lung cancer incidence even at concentrations below current EU limit values and possibly WHO Air Quality Guidelines
ECLAIRE: Effects of Climate Change on Air Pollution Impacts and Response Strategies for European Ecosystems. Project final report
The central goal of ECLAIRE is to assess how climate change will alter the extent to which air pollutants threaten terrestrial ecosystems. Particular attention has been given to nitrogen compounds, especially nitrogen oxides (NOx) and ammonia (NH3), as well as Biogenic Volatile Organic Compounds (BVOCs) in relation to tropospheric ozone (O3) formation, including their interactions with aerosol components. ECLAIRE has combined a broad program of field and laboratory experimentation and modelling of pollution fluxes and ecosystem impacts, advancing both mechanistic understanding and providing support to European policy makers.
The central finding of ECLAIRE is that future climate change is expected to worsen the threat of air pollutants on Europe’s ecosystems.
Firstly, climate warming is expected to increase the emissions of many trace gases, such as agricultural NH3, the soil component of NOx emissions and key BVOCs. Experimental data and numerical models show how these effects will tend to increase atmospheric N deposition in future. By contrast, the net effect on tropospheric O3 is less clear. This is because parallel increases in atmospheric CO2 concentrations will offset the temperature-driven increase for some BVOCs, such as isoprene. By contrast, there is currently insufficient evidence to be confident that CO2 will offset anticipated climate increases in monoterpene emissions.
Secondly, climate warming is found to be likely to increase the vulnerability of ecosystems towards air pollutant exposure or atmospheric deposition. Such effects may occur as a consequence of combined perturbation, as well as through specific interactions, such as between drought, O3, N and aerosol exposure.
These combined effects of climate change are expected to offset part of the benefit of current emissions control policies. Unless decisive mitigation actions are taken, it is anticipated that ongoing climate warming will increase agricultural and other biogenic emissions, posing a challenge for national emissions ceilings and air quality objectives related to nitrogen and ozone pollution. The O3 effects will be further worsened if progress is not made to curb increases in methane (CH4) emissions in the northern hemisphere.
Other key findings of ECLAIRE are that: 1) N deposition and O3 have adverse synergistic effects. Exposure to ambient O3 concentrations was shown to reduce the Nitrogen Use Efficiency of plants, both decreasing agricultural production and posing an increased risk of other forms of nitrogen pollution, such as nitrate leaching (NO3-) and the greenhouse gas nitrous oxide (N2O); 2) within-canopy dynamics for volatile aerosol can increase dry deposition and shorten atmospheric lifetimes; 3) ambient aerosol levels reduce the ability of plants to conserve water under drought conditions; 4) low-resolution mapping studies tend to underestimate the extent of local critical loads exceedance; 5) new dose-response functions can be used to improve the assessment of costs, including estimation of the value of damage due to air pollution effects on ecosystems, 6) scenarios can be constructed that combine technical mitigation measures with dietary change options (reducing livestock products in food down to recommended levels for health criteria), with the balance between the two strategies being a matter for future societal discussion. ECLAIRE has supported the revision process for the National Emissions Ceilings Directive and will continue to deliver scientific underpinning into the future for the UNECE Convention on Long-range Transboundary Air Pollution
ECLAIRE third periodic report
The ÉCLAIRE project (Effects of Climate Change on Air Pollution Impacts and Response Strategies for European Ecosystems) is a four year (2011-2015) project funded by the EU's Seventh Framework Programme for Research and Technological Development (FP7)
Two Cases of Progressive Familial Intrahepatic Cholestasis Type 2 Presenting with Severe Coagulopathy without Jaundice
Progressive familial intrahepatic cholestasis (PFIC) type 2 results from a mutation in the bile salt exporter pump, impeding bile acid transport. Patients usually present with jaundice, pruritus, growth failure, and fat soluble vitamin deficiencies. We present two patients diagnosed with PFIC type 2 due to severe coagulopathy and bleeding without jaundice
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