647 research outputs found
Adaptability of Irrigation to a Changing Monsoon in India: How far can we go?
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
Examining the sources of occupational stress in an emergency department
Background
Previous work has established that health care staff, in particular emergency department (ED) personnel, experience significant occupational stress but the underlying stressors have not been well quantified. Such data inform interventions that can reduce cases of occupational mental illness, burnout, staff turnover and early retirement associated with cumulative stress.
Aims
To develop, implement and evaluate a questionnaire examining the origins of occupational stress in the ED.
Methods
A questionnaire co-designed by an occupational health practitioner and ED management administered to nursing, medical and support staff in the ED of a large English teaching hospital in 2015. The questionnaire assessed participants’ demographic characteristics and perceptions of stress across three dimensions (demand–control–support, effort–reward and organizational justice). Work-related stressors in ED staff were compared with those of an unmatched control group from the acute ear, nose and throat (ENT) and neurology directorate.
Results
A total of 104 (59%) ED staff returned questionnaires compared to 72 staff (67%) from the acute ENT/neurology directorate. The ED respondents indicated lower levels of job autonomy, management support and involvement in organizational change, but not work demand. High levels of effort–reward imbalance and organizational injustice were reported by both groups.
Conclusions
Our findings suggest that internal ED interventions to improve workers’ job control, increase support from management and involvement in organizational change may reduce work stress. The high levels of effort–reward imbalance and organizational injustice reported by both groups may indicate that wider interventions beyond the ED are also needed to address these issues
Invisible water, visible impact: How unsustainable groundwater use challenges sustainability of Indian agriculture under climate change
India is one of the world’s largest food producers, making the sustainability of its agricultural system of global significance. Groundwater irrigation underpins India’s agriculture, currently boosting crop production by enough to feed 170 million people. Groundwater overexploitation has led to drastic declines in groundwater levels, threatening to push this vital resource out of reach for millions of small-scale farmers who are the backbone of India’s food security. Historically, losing access to groundwater has decreased agricultural production and increased poverty. We take a multidisciplinary approach to assess climate change challenges facing India’s agricultural system, and to assess the effectiveness of large-scale water infrastructure projects designed to meet these challenges. We find that even in areas that experience climate change induced precipitation increases, expansion of irrigated agriculture will require increasing amounts of unsustainable groundwater. The large proposed national river linking project has limited capacity to alleviate groundwater stress. Thus, without intervention, poverty and food insecurity in rural India is likely to worsen
Resilience: Protective Factors for Depression and Post Traumatic Stress Disorder among African American Women?
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
Host and Distribution Lists of Chiggers (Trombiculidae and Leeuwenhoekiidae), of North American Wild Vertebrates North of Mexico
Information concerning chiggers found on wild vertebrates of North America north of Mexico is summarized. Included are lists a) of the chiggers organized taxonomically, b) hosts from which each species has been reported, and c) states and provinces with references for each separate recor
Highly Parallel Translation of DNA Sequences into Small Molecules
A large body of in vitro evolution work establishes the utility of biopolymer libraries comprising 1010 to 1015 distinct molecules for the discovery of nanomolar-affinity ligands to proteins.[1], [2], [3], [4], [5] Small-molecule libraries of comparable complexity will likely provide nanomolar-affinity small-molecule ligands.[6], [7] Unlike biopolymers, small molecules can offer the advantages of cell permeability, low immunogenicity, metabolic stability, rapid diffusion and inexpensive mass production. It is thought that such desirable in vivo behavior is correlated with the physical properties of small molecules, specifically a limited number of hydrogen bond donors and acceptors, a defined range of hydrophobicity, and most importantly, molecular weights less than 500 Daltons.[8] Creating a collection of 1010 to 1015 small molecules that meet these criteria requires the use of hundreds to thousands of diversity elements per step in a combinatorial synthesis of three to five steps. With this goal in mind, we have reported a set of mesofluidic devices that enable DNA-programmed combinatorial chemistry in a highly parallel 384-well plate format. Here, we demonstrate that these devices can translate DNA genes encoding 384 diversity elements per coding position into corresponding small-molecule gene products. This robust and efficient procedure yields small molecule-DNA conjugates suitable for in vitro evolution experiments
A model for the degradation of polyimides due to oxidation
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
Context Matters: A Community-Based Study of Urban Minority Parents’ Views on Child Health
Background: Among children, there are substantial ethno-racial minority disparities across a broad range of health-related behaviors, experiences, and outcomes. Addressing these disparities is important, as childhood and adolescence establish health trajectories that extend throughout life.
Methods: The current study employed a community-based participatory research approach to gain community insight on child health priorities and to frame an intervention aimed at improving the health of minority children. Eight focus groups were conducted among seventy-five African American parents in a Southeastern city. The current study was guided by an ecological theoretical framework.
Results: Although the focus of this investigation was on community identification of child health priorities, participants cited, as root determinants, contextual factors, which included lack of healthy food options, lack of spaces for physical activity, and community violence. These co-occurring factors were related to limited engagement in outdoor activities and physical activity, increased obesity, and poor mental health and coping. Poor parenting was cited as the most substantial barrier to improving child health outcomes, and quality parenting was identified as the most important issue to address for community programs focused on promoting the health and success of children. For improving health outcomes for children in their neighborhoods, establishment of positive social capital and constructive activities were also cited.
Conclusions: These results reinforce social determinants of health as influences on child health outcomes and describe how community engagement can address potential solutions through interventions that resonate with program participants
Mesofluidic Devices for DNA-Programmed Combinatorial Chemistry
Hybrid combinatorial chemistry strategies that use DNA as an information-carrying medium are proving to be powerful tools for molecular discovery. In order to extend these efforts, we present a highly parallel format for DNA-programmed chemical library synthesis. The new format uses a standard microwell plate footprint and is compatible with commercially available automation technology. It can accommodate a wide variety of combinatorial synthetic schemes with up to 384 different building blocks per chemical step. We demonstrate that fluidic routing of DNA populations in the highly parallel format occurs with excellent specificity, and that chemistry on DNA arrayed into 384 well plates proceeds robustly, two requirements for the high-fidelity translation and efficient in vitro evolution of small molecules
Reactivity-Dependent PCR: Direct, Solution-Phase in Vitro Selection for Bond Formation
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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