465 research outputs found

    Adaptability of Irrigation to a Changing Monsoon in India: How far can we go?

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    Agriculture and the monsoon are inextricably linked in India. A large part of the steady rise in agricultural production since the onset of the Green Revolution in the 1960’s has been attributed to irrigation. Irrigation is used to supplement and buffer crops against precipitation shocks, but water availability for such use is itself sensitive to the erratic, seasonal and spatially heterogeneous nature of the monsoon. Most attention in the literature is given to crop yields (Guiteras, 2009; Fishman, 2012; Auffhammer et al, 2011) and their ability to withstand precipitation shocks, in the presence of irrigation (Fishman, 2012). However, there remains limited evidence about how natural weather variability and realized irrigation outcomes are related. We provide new evidence on the relationship between monsoon changes, irrigation variability and water availability by linking a process based hydrology model with an econometric model for one of the world’s most water stressed countries. India uses more groundwater for irrigation than any other country, and there is substantial evidence that this has led to depletion of groundwater aquifers. First, we build an econometric model of historical irrigation decisions using detailed crop-wise agriculture and weather data spanning 35 years from 1970-2004 for 311 districts across 19 major agricultural states in India. The source of agricultural data comes from the Village Dynamics in South Asia database at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT). Weather data is sourced from the only long term continental scale daily observationally gridded precipitation and temperature dataset called APHRODITE (Asian Precipitation- Highly Resolved Observational Data Integration Towards Evaluation of the Water Resources), that captures the spatial extent of the monsoon across the Himalayas, South and South-East Asia, and the Middle East in great detail. We use panel data approaches to control for unobserved and omitted variables that can confound the true impacts of weather variability on irrigation. Exploiting the exogenous inter-annual variability in the monsoon, our multivariate regression models reveal that for crops grown in the wet season, irrigation is sensitive to distribution and total monsoon rainfall but not to ground or surface water availability. For crops grown in the dry season, total monsoon rainfall matters most, and its effect is sensitive to groundwater availability but differentially so for shallow dug wells and deep tube wells. The historical estimates from the econometric model are used to calculate future irrigated areas using three different bias-corrected climate model projections of monsoon climate for the years 2010 – 2050 under the strongest warming scenario ( business as usual scenario) RCP-8.5 from the CMIP5 (Coupled Model Intercomparison Project) models. These projections are then used as input to a physical hydrology model, such as the Water Balance Model, that tracks water use and exchange between the ground, atmosphere, runoff and stream networks. This enables us to quantify supply of water required to meet irrigation needs from sustainable sources such as rechargeable shallow groundwater, rivers and reservoirs, as well as unsustainable sources such as non- rechargeable groundwater. Preliminary results show that the significant variation in monsoon projections lead to very different results. Crops grown in the dry season show particularly divergent trends between model projections, leading to very different groundwater resource requirements. By combining the strengths of the economic and hydrology components, this work highlights potential sustainable or unsustainable water use trajectories that different regions within India will face

    A solar cycle of spacecraft anomalies due to internal charging

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    International audienceIt is important to appreciate how the morphology of internal charging of spacecraft systems, due to penetrating electrons, differs from that of the more common surface charging, due to electrons with lower energy. A specific and recurrent anomaly on a geostationary communication satellite has been tracked for ten years so that solar cycle and seasonal dependencies can be clearly established. Concurrent measurements of sunspot number, solar wind speed and 2-day >2 MeV electron fluence are presented to highlight pertinent space weather relationships, and the importance of understanding the complex particle interaction processes involved

    Resilience: Protective Factors for Depression and Post Traumatic Stress Disorder among African American Women?

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    There is a great need to carefully examine issues that may elevate one’s risk for mental illness and develop strategies to mitigate risk and cultivate resilience.  African Americans, specifically African American women (AAW), are disproportionately affected by mental illness, including depression and post-traumatic stress disorder (PTSD).  Higher rates of PTSD among AAW may be explained by significant rates of trauma exposure.  Higher resiliency in individuals with mental illnesses is associated with better treatment response/outcomes.  An examination of two (2) promising psycho-educational curricula for AAW at risk for depression and PTSD supports consideration of resilience as a protective factor among this population.  Strengthening psychological resilience among diverse AAW at risk for depression and/or PTSD may serve as a protective factor for symptom severity.  Multidimensional prevention and intervention strategies should incorporate culturally-centered, gender-specific, and strengths-based (resilience) models of care to help encourage mental health help-seeking and promotion of wellness for AAW

    A model for the degradation of polyimides due to oxidation

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    Polyimides, due to their superior mechanical behavior at high temperatures, are used in a variety of applications that include aerospace, automobile and electronic packaging industries, as matrices for composites, as adhesives etc. In this paper, we extend our previous model in [S. Karra, K. R. Rajagopal, Modeling the non-linear viscoelastic response of high temperature polyimides, Mechanics of Materials, In press, doi:10.1016/j.mechmat.2010.09.006], to include oxidative degradation of these high temperature polyimides. Appropriate forms for the Helmholtz potential and the rate of dissipation are chosen to describe the degradation. The results for a specific boundary value problem, using our model compares well with the experimental creep data for PMR-15 resin that is aged in air.Comment: 13 pages, 2 figures, submitted to Mechanics of Time-dependent Material

    Utilization of a Community-based Participatory Approach to Design and Implement a Peer-led Parenting Pilot Intervention to Influence Child Nutritional and Physical Activity Behaviors

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    Parents and primary child guardians within the household play critical roles in shaping their children’s nutritional and physical activity behaviors, which are among the individual-level determinants of childhood obesity and other chronic conditions. There are well-established correlations between race, socioeconomic status and the risk for obesity calling for both contextually- and individual-centered interventions that are community-driven. The Using Quality Parenting (UQP) pilot intervention was a peer-led, parenting education intervention developed in collaboration with community residents in Atlanta, Georgia to influence child nutritional and physical activity behaviors in African American low socioeconomic status communities. A community-based participatory research (CBPR) framework was used to conduct a mixed-methods needs assessment designed to the UQP curriculum. The UQP program targeted parents of children ages 6-14. The overarching aim was to increase quality parenting and address community identified child obesity disparities and inequities in early and middle childhood. The topics pertaining to parenting to children’s health/well-being addressed by the UQP included nutrition, physical activity, socio-emotional development, positive parenting, coping skills, child advocacy, and community development. Analyses were conducted using PSAW 18 statistical software. Descriptive statistics, including frequencies, means, standard deviations, and ranges for the individual survey items were conducted. A t-test was performed comparing pre- and post-program participation. A repeated measure analysis of variance was conducted on the items that demonstrated a significant t-test. The analytic sample was composed of 46 African American parents, with over 50% of the sample earning an annual household income of $25,000 or less. Participating parents reported significantly higher levels of water consumption for their children post-program in comparison to pre-test reports (p = .010). Additionally, based on t-test analyses, parents reported that their children consumed significantly higher levels of proteins, grains, fruits and vegetables at each meal, post-program (p=0.03). These findings highlight the potential efficacy of community-informed, parent-led interventions in improving health disparities and related outcomes for children

    Environmental Forcings of Paleogene Southern Ocean Dinoflagellate Biogeography

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    Despite warm polar climates and low meridional temperature gradients, a number of different high-latitude plankton assemblages were, to varying extents, dominated by endemic species during most of the Paleogene. To better understand the evolution of Paleogene plankton endemism in the high southern latitudes, we investigate the spatiotemporal distribution of the fossil remains of dinoflagellates, i.e., organic-walled cysts (dinocysts), and their response to changes in regional sea surface temperature (SST). We show that Paleocene and early Eocene (∼65–50 Ma) Southern Ocean dinocyst assemblages were largely cosmopolitan in nature but that a distinct switch from cosmopolitan-dominated to endemic-dominated assemblages (the so-called “transantarctic flora”) occurred around the early-middle Eocene boundary (∼50 Ma). The spatial distribution and relative abundance patterns of this transantarctic flora correspond well with surface water circulation patterns as reconstructed through general circulation model experiments throughout the Eocene. We quantitatively compare dinocyst assemblages with previously published TEX86–based SST reconstructions through the early and middle Eocene from a key locality in the southwest Pacific Ocean, ODP Leg 189 Site 1172 on the East Tasman Plateau. We conclude that the middle Eocene onset of the proliferation of the transantarctic flora is not linearly correlated with regional SST records and that only after the transantarctic flora became fully established later in the middle Eocene, possibly triggered by large-scale changes in surface-ocean nutrient availability, were abundances of endemic dinocysts modulated by regional SST variations

    (Certified) Humane Violence? Animal Production, the Ambivalence of Humanizing the Inhumane, and What International Humanitarian Law Has to Do with It

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    The chapter draws a comparison with the self-certifying of production methods as ‘humane’ or animal-friendly in the labelling of animal products—that is, according to companies’ own self-imposed codes of conduct. It likens the idea of humanizing animal slaughter, factory farms, and other forms of production to the notion of humanizing warfare. Like international humanitarian law (IHL), animal welfare law is marked by the tension inherent in its attempt to humanize innately inhumane practices. Given these parallels, the analysis of animal welfare law might benefit from existing insights into the potential and limits of IHL. Both areas of law endorse a principle of ‘humanity’ while arguably facilitating and legitimizing the use of violence, and might thereby ultimately perpetuate the suffering of living beings. The implicit justification of violence percolating from the IHL-like animal ‘protection’ laws could only be outweighed by complementing this body of law with a ius contra bellum for animals

    Reactivity-Dependent PCR: Direct, Solution-Phase in Vitro Selection for Bond Formation

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    In vitro selection is a key component of efforts to discover functional nucleic acids and small molecules from libraries of DNA, RNA, and DNA-encoded small molecules. Such selections have been widely used to evolve RNA and DNA catalysts and, more recently, to discover new reactions from DNA-encoded libraries of potential substrates. While effective, current strategies for selections of bond-forming and bond-cleaving reactivity are generally indirect, require the synthesis of biotin-linked substrates, and involve multiple solution-phase and solid-phase manipulations. In this work we report the successful development and validation of reactivity-dependent PCR (RDPCR), a new method that more directly links bond formation or bond cleavage with the amplification of desired sequences and that obviates the need for solid-phase capture, washing, and elution steps. We show that RDPCR can be used to select for bond formation in the context of reaction discovery and for bond cleavage in the context of protease activity profiling.Chemistry and Chemical Biolog
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