679 research outputs found

    Soil carbon insures arable crop production against increasing adverse weather due to climate change

    Get PDF
    Intensification of arable crop production degrades soil health and production potential through loss of soil organic carbon. This, potentially, reduces agriculture's resilience to climate change and thus food security. Furthermore, the expected increase in frequency of adverse and extreme weather events due to climate change are likely to affect crop yields differently, depending on when in the growing season they occur. We show that soil carbon provides farmers with a natural insurance against climate change through a gain in yield stability and more resilient production. To do this, we combined yield observations from 12 sites and 54 years of Swedish long-term agricultural experiments with historical weather data. To account for heterogenous climate effects, we partitioned the growing season into four representative phases for two major cereal crops. Thereby, we provide evidence that higher soil carbon increases yield gains from favourable conditions and reduces yield losses due to adverse weather events and how this occurs over different stages of the growing season. However, agricultural management practices that restore the soil carbon stock, thus contributing to climate change mitigation and adaptation, usually come at the cost of foregone yield for the farmer in the short term. To halt soil degradation and make arable crop production more resilient to climate change, we need agricultural policies that address the public benefits of soil conservation and restoration

    Study of ventilation with different inspired oxygen concentration on lung ischaemia-reperfusion injury in rats

    Get PDF
    PURPOSE: To evaluate the FiO2 effect at 0,21, 0,40 and 1,00 on the lung ischaemia-reperfusion injury. METHODS: Forty Wistar rats were randomly allocated in 4 groups. The group I was the control one, and in groups II, III, IV rats were ventilated during the ischaemia-reperfusion at 0,21, 0,40 and 1.00 FiO2 respectively. The ischaemia time was 30 minutes and the reperfusion time was 10 minutes. The model used was normothermic ischaemia-reperfusion, in situ. As assessment parameters, the systemic average arterial pressure (PAM), the oxygen arterial partial pressure/ inspired oxygen fraction relation (PO2/FiO2), the level of reduced glutathione (GSH) and barbituric acid substances reactive measure (TBARS) in the lung tissue and the lung wet/dry weight ratio were used. RESULTS: The results showed that the ventilation with FiO2 at 0,21, when compared with the ventilation at 0,40 and 1,00 FiO2 during the ischaemia-reperfusion period, presented lower PAM, better PO2/FiO2 relation, higher values in the reduced glutathione measures, lower production of the TBARS and lower formation of lung edema. CONCLUSION: The ventilation with low FiO2 (0.21) showed better results when compared to those performed with higher FiO2 (0,40 and 1,00) on the lung ischaemia-reperfusion injury.OBJETIVO: Estudar o efeito das fraçÔes inspiradas de oxigĂȘnio (FiO2) a 0,21, 0,40 e 1,00 na isquemia-reperfusĂŁo pulmonar. MÉTODOS: Foram utilizados 40 ratos Wistar, distribuĂ­dos aleatoriamente em quatro grupos. O grupo I foi o controle e, nos grupos II, III e IV, os animais foram ventilados durante a isquemia-reperfusĂŁo com FiO2 a 0,21, 0,40 e 1,00 respectivamente. O modelo utilizado foi de isquemia-reperfusĂŁo normotĂ©rmica, in situ. O tempo de isquemia foi de 30 minutos e o de reperfusĂŁo, de 10 minutos. Como parĂąmetros de avaliação, utilizou-se a pressĂŁo arterial mĂ©dia sistĂȘmica (PAM), a relação entre a pressĂŁo parcial de oxigĂȘnio e a fração inspirada de oxigĂȘnio (PO2/FiO2), a dosagem da glutationa reduzida (GSH) e das substĂąncias reativas ao ĂĄcido tiobarbitĂșrico (TBARS) no tecido pulmonar e a relação entre o peso pulmonar Ășmido e o peso pulmonar seco. RESULTADOS: Os resultados mostraram que a ventilação com FiO2 a 0,21, quando comparada Ă  ventilação com FiO2 a 0,40 e 1,00, durante o perĂ­odo de isquemia-reperfusĂŁo, apresentou menor diminuição da PAM, melhor relação PO2/FiO2, maior valor na medida da GSH, menor produção das TBARS e menor formação de edema pulmonar. CONCLUSÃO: A ventilação com baixa FiO2 (0,21) mostrou melhores resultados quando comparada Ă quelas realizadas com FiO2 mais elevadas (0,40 e 1,00) na isquemia-reperfusĂŁo pulmonar.Secretaria Estadual de SaĂșde de Santa CatarinaUniversidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de Santa Catarina Escola Paulista de Medicina Departamento de CirurgiaUniversidade Federal de Santa Catarina Departamento de ClĂ­nica CirĂșrgicaUniversidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de Medicina Departamento de CirurgiaUNIFESP, EPMUniversidade Federal de Santa Catarina Escola Paulista de Medicina Depto. de CirurgiaUNIFESP, EPM, Depto. de CirurgiaSciEL

    MIAME/Plant – adding value to plant microarrray experiments

    Get PDF
    Appropriate biological interpretation of microarray data calls for relevant experimental annotation. The widely accepted MIAME guidelines provide a generic, organism-independant standard for minimal information about microarray experiments. In its overall structure, MIAME is very general and specifications cover mostly technical aspects, while relevant organism-specific information useful to understand the underlying experiments is largely missing. If plant biologists want to use results from published microarray experiments, they need detailed information about biological aspects, such as growth conditions, harvesting time or harvested organ(s). Here, we propose MIAME/Plant, a standard describing which biological details to be captured for describing microarray experiments involving plants. We expect that a more detailed and more systematic annotation of microarray experiments will greatly increase the use of transcriptome data sets for the scientific community. The power and value of systematic annotation of microarray data is convincingly demonstrated by data warehouses such as Genevestigator(Âź )or NASCArrays, and better experimental annotation will make these applications even more powerful

    Climate change and ecological intensification of agriculture in sub-Saharan Africa-A systems approach to predict maize yield under push-pull technology

    Get PDF
    Assessing effects of climate change on agricultural systems and the potential for ecological intensification to increase food security in developing countries is essential to guide management, policy-making and future research. 'Push-pull' technology (PPT) is a poly-cropping design developed in eastern Africa that utilizes plant chemicals to mediate plant-insect interactions. PPT application yields significant increases in crop productivity, by reducing pest load and damage caused by arthropods and parasitic weeds, while also bolstering soil fertility. As climate change effects may be species-and/or context-specific, there is need to elucidate how, in interaction with biotic factors, projected climate conditions are likely to influence future functioning of PPT. Here, we first reviewed how changes in temperature, precipitation and atmospheric CO2 concentration can influence PPT components (i.e., land use, soils, crops, weeds, diseases, pests and their natural enemies) across sub-Saharan Africa (SSA). We then imposed these anticipated responses on a landscape-scale qualitative mathematical model of maize production under PPT in eastern Africa, to predict cumulative, structure-mediated impacts of climate change on maize yield. Our review suggests variable impacts of climate change on PPT components in SSA by the end of the 21st century, including reduced soil fertility, increased weed and arthropod pest pressure and increased prevalence of crop diseases, but also increased biological control by pests' natural enemies. Extrapolating empirical evidence of climate effects to predict responses to projected climate conditions is mainly limited by a lack of mechanistic understanding regarding single and interactive effects of climate variables on PPT components. Model predictions of maize yield responses to anticipated impacts of climate change in eastern Africa suggest predominantly negative future trends. Nevertheless, maize yields can be sustained or increased by favourable changes in system components with less certain future behaviour, including higher PPT adoption, preservation of field edge density and agricultural diversification beyond cereal crops

    Overnight Immune Regulation and Subjective Measures of Sleep: A Three Night Observational Study in Adolescent Track and Field Athletes

    Get PDF
    To ensure health maintenance of young athletes, immunological stress due to physical exercise has to be balanced for performance development and health maintenance. Sleep is an important influencing factor for immune regulation because of its regenerating effect. In an attempt to assess overnight immune regulation, this observational study aimed to examine associations between changes in capillary immunological blood markers and measures of sleep in adolescent athletes. Over a period of three nights, 12 male ( n = 6) and female ( n = 6) adolescent track and field athletes aged 16.4 ± 1.1 years were monitored for their sleep behavior (e.g., sleep duration, sleep depth) and immune regulation by using subjective (e.g., sleep) and objective (capillary blood markers) measurement tools. Over the 4 day (three nights), athletes followed their daily routines (school, homework, free time activities, and training). Training was performed for different disciplines (sprint, hurdles, and long-jump) following their daily training routines. Training included dynamic core stability training, coordination training, speed training, resistance training, and endurance training. Capillary blood samples were taken 30–45 min after the last training session (10:00–12:00 a.m. or 5:00–6:00 p.m.) and every morning between 7:00 and 10:00 a.m. Changes in capillary blood markers from post-training to the next morning and morning-to-morning fluctuations in capillary blood markers were analyzed over a three-night period using a generalized estimating equations (GEE) statistical approach. Associations of overnight changes with measures of sleep were analyzed using GEE. We found significant decreases in white blood cell count (WBC), granulocytes (GRAN), granulocytes% (GRAN%), monocytes (MID), and granulocyte-lymphocyte-ratio. In contrast, lymphocytes% (LYM%) increased significantly and systemic inflammation index showed no difference from post-training to the next morning. Furthermore, there was a significant decrease in WBC and GRAN between morning 1 and morning 3. At morning 4, values returned to baseline (morning 1), irrespective if athletes performed a training session or rested on day 3. Furthermore, sleep duration was significantly and negatively associated with changes in WBC (ÎČ z = −0.491) and lymphocytes (ÎČ z = −0.451). Our results indicate that overnight sleep duration is an important parameter of immunological overnight regulation for adolescent athletes

    The Structure of Ca2+ Sensor Case16 Reveals the Mechanism of Reaction to Low Ca2+ Concentrations

    Get PDF
    Here we report the first crystal structure of a high-contrast genetically encoded circularly permuted green fluorescent protein (cpGFP)-based Ca2+ sensor, Case16, in the presence of a low Ca2+ concentration. The structure reveals the positioning of the chromophore within Case16 at the first stage of the Ca2+-dependent response when only two out of four Ca2+-binding pockets of calmodulin (CaM) are occupied with Ca2+ ions. In such a “half Ca2+-bound state”, Case16 is characterized by an incomplete interaction between its CaM-/M13-domains. We also report the crystal structure of the related Ca2+ sensor Case12 at saturating Ca2+ concentration. Based on this structure, we postulate that cpGFP-based Ca2+ sensors can form non-functional homodimers where the CaM-domain of one sensor molecule binds symmetrically to the M13-peptide of the partner sensor molecule. Case12 and Case16 behavior upon addition of high concentrations of free CaM or M13-peptide reveals that the latter effectively blocks the fluorescent response of the sensor. We speculate that the demonstrated intermolecular interaction with endogenous substrates and homodimerization can impede proper functioning of this type of Ca2+ sensors in living cells

    Evolutionary games on graphs

    Full text link
    Game theory is one of the key paradigms behind many scientific disciplines from biology to behavioral sciences to economics. In its evolutionary form and especially when the interacting agents are linked in a specific social network the underlying solution concepts and methods are very similar to those applied in non-equilibrium statistical physics. This review gives a tutorial-type overview of the field for physicists. The first three sections introduce the necessary background in classical and evolutionary game theory from the basic definitions to the most important results. The fourth section surveys the topological complications implied by non-mean-field-type social network structures in general. The last three sections discuss in detail the dynamic behavior of three prominent classes of models: the Prisoner's Dilemma, the Rock-Scissors-Paper game, and Competing Associations. The major theme of the review is in what sense and how the graph structure of interactions can modify and enrich the picture of long term behavioral patterns emerging in evolutionary games.Comment: Review, final version, 133 pages, 65 figure

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

    Get PDF
    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
    • 

    corecore