Abnormal brain development in mice with region- and cell-type-specific inactivation of ST8SIA2

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Quantification of heat-stress related mortality hazard, vulnerability and risk in Berlin, Germany

Many studies have addressed the challenge of heat stress for human health in recent years. However, appropriate concepts and methods for quantifying heat-stress hazards, vulnerabilities and risks are yet under development. The objective of this study is to test the applicability of a risk concept and associated event-based risk-analysis method for quantifying heat-stress related mortality. The study reveals that about 5 % of all deaths between 2001 and 2010 in Ber­lin can statistically be related to elevated air temperatures. Most of the affected people are 65 years or older, while the mortality of people below 65 years shows only weak statistical correlation to air temperature. Mean daily air tempera­ture was best suitable for risk analysis. The results demonstrate that the novel approach for quantitative risk analysis delivers statistically highly significant results on the city scale when analysing heat stress on an event basis. Performing the risk analysis on a spatially distributed data basis for city districts would allow to account for spatial variations of ur­ban climates and demographic properties. Using indoor climate data is expected to provide new insight into heat-stress related mortality risks, particularly for highly vulnerable persons like elderly persons or patients residing in hospitals

Developments in marine pCO2 measurement technology; towards sustained in situ observations

The oceanic uptake of anthropogenic CO2 causes pronounced changes to the marine carbonate system. High quality pCO2 measurements with good temporal and spatial coverage are required to monitor the oceanic uptake, identify regions with pronounced carbonate system changes, and observe the effectiveness of CO2 emission mitigation strategies. There are currently several instruments available, but many are unsuitable for autonomous deployments on in situ platforms such as gliders, moorings and Argo floats. We assess currently available technology on its suitability for in situ deployment, with a focus on optode technology developments. Optodes for pCO2 measurements provide a promising new technological approach, and were successfully calibrated over the range of 280–480 μatm applying modified time-domain dual lifetime referencing. A laboratory precision of 0.8 μatm (n = 10) and a response time (τ90) of 165 s were achieved, and with further development pCO2 optodes may become as widely used as their oxygen counterparts

Impact of physical and biological processes on temporal variations of the ocean carbon sink in the mid-latitude North Atlantic (2002–2016)

The ocean is currently a significant net sink for anthropogenically remobilised CO2, taking up around 24% of global emissions. Numerical models predict a diversity of responses of the ocean carbon sink to increased atmospheric concentrations in a warmer world. Here, we tested the hypothesis that increased atmospheric forcing is causing a change in the ocean carbon sink using a high frequency observational dataset derived from underway pCO2 (carbon dioxide partial pressure) instruments on ships of opportunity (SOO) and a fixed-point mooring between 2002 and 2016. We calculated an average carbon flux of 0.013 Pg yr−1 into the ocean at the Porcupine Abyssal Plain (PAP) site, consistent with past estimates. In spite of the increase in atmospheric pCO2, monthly average seawater pCO2 did not show a statistically significant increasing trend, but a higher annual variability, likely due to the decreasing buffer capacity of the system. The increasing led to an increasing trend in the estimated CO2 flux into the ocean of 0.19 ± 0.03 mmol m−2 day−1 per year across the entire 15 year time series, making the study area a stronger carbon sink. Seawater pCO2 variability is mostly influenced by temperature, alkalinity and dissolved inorganic carbon (DIC) changes, with 77% of the annual seawater pCO2 changes explained by these terms. DIC is in turn influenced by gas exchange and biological production. In an average year, the DIC drawdown by biological production, as determined from nitrate uptake, was higher than the DIC increase due to atmospheric CO2 dissolution into the surface ocean. This effect was enhanced in years with high nutrient input or shallow mixed layers. Using the rate of change of DIC and nitrate, we observed Redfieldian carbon consumption during the spring bloom at a C:N ratio of 6.2 ± 1.6. A comparison between SOO and PAP sustained observatory data revealed a strong agreement for pCO2 and DIC. This work demonstrates that the study area has continued to absorb atmospheric CO2 in recent years with this sink enhancing over time. Furthermore, the change in pCO2 per unit nitrate became larger as surface buffer capacity changed

Süßholz (Glycyrrhiza glabra) - Extrakt zur Regulierung von Falschem Mehltau im Öko-Gemüseanbau

A raw extract of licorice (Glycyrrhiza glabra) was tested against downy mildew in vegetables under semi-commercial conditions. In two greenhouse trials in cucumber, efficacies of ca. 70% were achieved (3% extract concentration) in either 7 or 10-11 day application intervals. Under open field conditions, weekly treatments resulted in ca. 2 week retardation of disease. In open field trials in lettuce, efficacies after weekly application of 5% G. glabra extract were variable, depending on disease pressure. In contrast, on lettuce seedlings in climate chambers, the extract reduced disease incidence of Bremia lactucae by 66 to 100%. In onion, applications of the extract at 6% concentration failed to control Peronospora destructor, despite of high efficacies under controlled conditions in the greenhouse. Overall, the G. glabra raw extract was highly effective in protected vegetables. Under field conditions low efficacies were most likely due to reduced rain fastness or UV-stability

Net community production in the North Atlantic Ocean derived from Volunteer Observing Ship data

The magnitude of marine plankton net community production (NCP) is indicative of both the biologically driven exchange of carbon dioxide between the atmosphere and the surface ocean and the export of organic carbon from the surface ocean to the ocean interior. In this study the seasonal variability in the NCP of five biogeochemical regions in the North Atlantic was determined from measurements of surface water dissolved oxygen and dissolved inorganic carbon (DIC) sampled from a Volunteer Observing Ship (VOS). The magnitude of NCP derived from dissolved oxygen measurements (NCPinline image) was consistent with previous geochemical estimates of NCP in the North Atlantic, with an average annual NCPinline image of 9.5 ± 6.5 mmol O2 m−2 d−1. Annual NCPinline image did not vary significantly over 35° of latitude and was not significantly different from NCP derived from DIC measurements (NCPDIC). The relatively simple method described here is applicable to any VOS route on which surface water dissolved oxygen concentrations can be accurately measured, thus providing estimates of NCP at higher spatial and temporal resolution than currently achieved

Delta-like 4 is the essential, nonredundant ligand for Notch1 during thymic T cell lineage commitment

Thymic T cell lineage commitment is dependent on Notch1 (N1) receptor–mediated signaling. Although the physiological ligands that interact with N1 expressed on thymic precursors are currently unknown, in vitro culture systems point to Delta-like 1 (DL1) and DL4 as prime candidates. Using DL1- and DL4-lacZ reporter knock-in mice and novel monoclonal antibodies to DL1 and DL4, we show that DL4 is expressed on thymic epithelial cells (TECs), whereas DL1 is not detected. The function of DL4 was further explored in vivo by generating mice in which DL4 could be specifically inactivated in TECs or in hematopoietic progenitors. Although loss of DL4 in hematopoietic progenitors did not perturb thymus development, inactivation of DL4 in TECs led to a complete block in T cell development coupled with the ectopic appearance of immature B cells in the thymus. These immature B cells were phenotypically indistinguishable from those developing in the thymus of conditional N1 mutant mice. Collectively, our results demonstrate that DL4 is the essential and nonredundant N1 ligand responsible for T cell lineage commitment. Moreover, they strongly suggest that N1-expressing thymic progenitors interact with DL4-expressing TECs to suppress B lineage potential and to induce the first steps of intrathymic T cell development

Trends in anthropogenic CO2 in water masses of the Subtropical North Atlantic Ocean

12 páginas, 4 figuras,1 tabla.-- Proyecto CarbochangeThe variability in the storage of the oceanic anthropogenic CO2 (Cant) on decadal timescales is evaluated within the main water masses of the Subtropical North Atlantic along 24.5°N. Inorganic carbon measurements on five cruises of the A05 section are used to assess the changes in Cant between 1992 and 2011, using four methods (ΔC∗, TrOCA, φCT0, TTD). We find good agreement between the Cant distribution and storage obtained using chlorofluorocarbons and CO2 measurements in both the vertical and horizontal scales. Cant distribution shows higher concentrations and greater decadal storage rates in the upper layers with both values decreasing with depth. The greatest enrichment is obserbed in the central water masses, with their upper limb showing a mean annual accumulation of about 1 μmol kg−1 yr−1 and the lower limb showing, on average, half that value. We detect zonal gradients in the accumulation of Cant. This finding is less clear in the upper waters, where greater variability exists between methods. In accordance with data from time series stations, greater accumulation of Cant is observed in the upper waters of the western basin of the North Atlantic Subtropical Gyre. In intermediate and deep layers, the zonal gradient in the storage of Cant is more robust between methods. The much lower mean storage rates found along the section (<0.25 μmol kg−1 yr−1) become more obvious when longitudinal differences in the Cant accumulation are considered. In particular, west of 70°W the ventilation by the Labrador Sea Water creates a noticeable accumulation rate up to ∼0.5 μmol kg−1 yr−1 between 1000 and 2500 dbar. If a Transient Stationary State of the Cant distributions is considered, significant bi-decadal trends in the Cant storage rates in the deepest North Atlantic waters are detected, in agreement with recent estimations.We acknowledge funding from the Spanish Ministry of Economy and Competitiveness through Grants CSD2008-00077 (Circumnavigation Expedition MALASPINA 2010 Project), CTM2009-08849 (ACDC Project) and CTM2012-32017 (MANIFEST Project). We also acknowledge funding from the EU FP7 project CARBOCHANGE under Grant Agreement No. 264879 and by the Marine Biogeochemistry and Global Change research group (Generalitat de Catalunya, 2014SGR1029). E.F. Guallart was funded through a JAE-Pre grant that was financed by the Spanish National Research Council Agency (Consejo Superior de Investigaciones Científicas, CSIC) and by the European Social Fund.Peer reviewe

Carbon dioxide and ocean acidification observations in UK waters. Synthesis report with a focus on 2010–2015

Key messages: 1.1 The process of ocean acidification is now relatively well-documented at the global scale as a long-term trend in the open ocean. However, short-term and spatial variability can be high. 1.2 New datasets made available since Charting Progress 2 make it possible to greatly improve the characterisation of CO2 and ocean acidification in UK waters. 3.1 Recent UK cruise data contribute to large gaps in national and global datasets. 3.2 The new UK measurements confirm that pH is highly variable, therefore it is important to measure consistently to determine any long term trends. 3.3 Over the past 30 years, North Sea pH has decreased at 0.0035±0.0014 pH units per year. 3.4 Upper ocean pH values are highest in spring, lowest in autumn. These changes reflect the seasonal cycles in photosynthesis, respiration (decomposition) and water mixing. 3.5 Carbonate saturation states are minimal in the winter, and lower in 7 more northerly, colder waters. This temperature-dependence could have implications for future warming of the seas. 3.6 Over the annual cycle, North-west European seas are net sinks of CO2. However, during late summer to autumn months, some coastal waters may be significant sources. 3.7 In seasonally-stratified waters, sea-floor organisms naturally experience lower pH and saturation states; they may therefore be more vulnerable to threshold changes. 3.8 Large pH changes (0.5 - 1.0 units) can occur in the top 1 cm of sediment; however, such effects are not well-documented. 3.9 A coupled forecast model estimates the decrease in pH trend within the North Sea to be -0.0036±0.00034 pH units per year, under a high greenhouse gas emissions scenario (RCP 8.5). 3.10 Seasonal estimates from the forecast model demonstrate areas of the North Sea that are particularly vulnerable to aragonite undersaturation