529 research outputs found

    Toward a feminist political ecology of household food and water security during drought in northern Nicaragua

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    Few studies assess the relationship between food and water access, despite global concerns about people’s inability to maintain access to both food and water. We conducted a mixed-methods comparative case study in northern Nicaragua, with smallholders from two neighboring communities that differed in water availability and institutional strength, using a feminist political ecology framework and food and water security definitions that focus on access, availability, use, and stability. We adopted a participatory approach that included: a sex-disaggregated survey in 2016; interviews, participant observation, and community-based water quality testing from 2014 to 2019; and analysis of a severe drought that occurred from 2014 to 2017. Our results suggest that uneven power relations, biophysical conditions, gender, and institutions shape food and water access, and indicate that households across both communities average 2 months of drinking water insecurity during the dry season followed by an average of 2.5 months of food insecurity early in the growing season. The average duration of lean food months was similar across communities and sex, but water insecurity lasted longer in the community that had weaker local institutions and less surface water availability. Ethnographic research helped to document uneven and gendered experiences of water access and to illustrate how they were also shaped by conflicts over water for irrigation vs. domestic uses and cross-scalar limitations in water and land governance. Although we found that gender and institutions were not strong predictors of several food and water insecurity indicators on their own, both factors influenced the terms of access, conflict, and cooperative governance needed to secure resources and well-being. Our study highlights the need for theory, methods, and field research that integrate the analysis of food and water security, and it contributes to developing a feminist political ecology approach that unifies this analysis with a focus on gender

    Modifying the Einstein Equations off the Constraint Hypersuface

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    A new technique is presented for modifying the Einstein evolution equations off the constraint hypersurface. With this approach the evolution equations for the constraints can be specified freely. The equations of motion for the gravitational field variables are modified by the addition of terms that are linear and nonlocal in the constraints. These terms are obtained from solutions of the linearized Einstein constraints.Comment: 4 pages, 1 figure, uses REVTe

    Long-term Weight Gain in Response to High-fat Feeding in CD-1 mice

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    Background. Excessive weight gain is known to cause numerous health related consequences in humans and rodents. Due to ethical issues, it is not appropriate to cause weight gain in humans. From an experimental design prospective, murine models are often used to measure the effect of weight gain. Despite the validity of murine models, there is little published information concerning long-term weight gain when mice consume a high-fat (60% of calories from fat) diet. The purpose of this study was to examine weight gain during high-fat feeding in wild type CD-1 male mice. Methods. This study utilized data collected during the completion of four separate experiments. These experiments were selected so that we could compare: 1) the effects of husbandry type (i.e. individual vs. small groups), 2) weight gain following discontinuation of aerobic exercise training, and 3) the effect of changing to a high-fat diet following long-term acclimation to a stock diet. Two separate data sets were used for experiment 1 (N=120 and N=36). The data set used for experiment 2 demonstrates the long-term effects of the discontinuation of an exercise program (N=24). The data set for experiment 3 allows us to examine the effects of switching diets after an extended period of time (N=36). Change data was analyzed using separate linear mixed models (LMM) for weight gain and food intake. Results. Weight gain was similar over time between mice housed in groups or individually (experiment one). Following discontinuation of an aerobic exercise-training program, mice gained weight similar to that of sedentary controls that did not exercise (experiment two). When mice are switched to a high-fat diet at 25 weeks of age, they gain less weight than when they eat a high-fat diet at 6 weeks of age (experiment three). Conclusions. The results our investigation document long-term changes in mouse weight gain during ad libitum consumption of a high-fat diet. These findings will be useful to future researchers interested in using murine weight gain models

    Aerobic Exercise Training May Not Offset the Pro-inflammatory Effects of a High Fat Feeding

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    Aerobic Exercise Training May Not Offset the Pro-inflammatory Effects of a High Fat Feeding. Katie C. Carpenter, Lisa Esposito, Kelley A. Strohacker, Richard J. Simpson, Brian K. McFarlin. University of Houston, Houston, TX Increased adiposity is associated with an increase in systemic inflammation, which is involved in the pathophysiology of various disease states. A current hypothesis in our laboratory suggests that the toll-like receptor 4 (TLR4) pathway may link physical activity and systemic inflammation. PURPOSE: The primary purpose was to determine if 6-weeks of aerobic exercise training (5 days per week, 1 hour per day. 21-22m/min) would limit the increase in systemic inflammation resulting from high-fat (60% of calories from fat) feeding. A secondary purpose was to determine if changes in cell-surface TLR4 expression would account for observed differences in inflammatory status between mice which exercise and those that remain sedentary. METHODS: 36 CD-1 male mice were randomly assigned to one of three groups (N=12/group): HF (remained sedentary and consumed a high-fat chow (60% fat)), HF-EX (consumed the high-fat chow and underwent an aerobic exercise intervention (running 4.56±0.08 h/week for 6 weeks, or LF (sedentary and consumed a low-fat chow (10% fat)). Key outcome measurements were made on weekly saphenous vein blood samples (~40 uL) using 3-color flow cytometry. Blood glucose and cholesterol concentration were analyzed by an enzymatic assay. RESULTS: Absolute and percent body weight gain over 6-weeks was similar between HF and HF-EX, but significantly greater than LF (P\u3c0.001). HF and HF-EX had 66% more leukocytes than LF at weeks 3-5 (P\u3c0.0001). HF and HF-EX had 145% greater CD11b+/14+/TLR4+ cells than LF (P=0.001). There was no difference in the concentration of CD11b+ cells expressing IL-6 or TNF-alpha following LPS-stimulation between HF and HF-EX. No significant difference was found for blood glucose and cholesterol concentrations between groups. CONCLUSIONS: Exercise training did not prevent weight gain during 6-weeks of high fat feeding. Since HF and HF+EX gained a similar amount of weight, they did not differ with regarding to blood monocytes expressing TLR4. Both HF and HF+EX were elevated above LF. More research is needed to determine how changes in the blood relate to changes in peripheral tissue compartments

    Towards smallholder food and water security: Climate variability in the context of multiple livelihood hazards in Nicaragua

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    Climate variability and change affect both food and water security, as do other hazards, such as shifting food prices, plant pathogens, and political economic changes. Although household food and water insecurity affect billions, most studies analyze them separately. This article develops a relational approach to explaining household access to food and water in a multi-hazard context. We identify pathways linking hazards to livelihood vulnerability and assess the relative importance of climate-related hazards. Analyzing longitudinal data collected from two surveys of the same 311 smallholder households in northern Nicaragua, conducted in 2014 and again in 2017, we find that peak seasons of food and water stress are asynchronous across the agricultural calendar, resulting in a total of five to six months of food and/or water stress. Across households, we find a significant positive relationship between water and food insecurity, even after adjusting for household fixed effects. Households experienced less food and water insecurity in 2017 than in 2014, due in part to the end of a severe drought in 2016, but remained concerned about damage from a severe coffee leaf rust outbreak and unfavorable agrifood prices that reduce income and threaten food security. Higher incomes and larger farm areas correlated with improved food and water security. We propose a generalizable approach for the joint assessment of household food and water security, which foregrounds the influence of seasonality and climate variability in the context of multiple hazards. This approach and our findings can contribute to developing integrated risk reduction strategies, building resilient livelihoods, and informing policy changes and partnerships with organized smallholders to improve resource access and sovereignty

    Early (and Later) LHC Search Strategies for Broad Dimuon Resonances

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    Resonance searches generally focus on narrow states that would produce a sharp peak rising over background. Early LHC running will, however, be sensitive primarily to broad resonances. In this paper we demonstrate that statistical methods should suffice to find broad resonances and distinguish them from both background and contact interactions over a large range of previously unexplored parameter space. We furthermore introduce an angular measure we call ellipticity, which measures how forward (or backward) the muon is in eta, and allows for discrimination between models with different parity violation early in the LHC running. We contrast this with existing angular observables and demonstrate that ellipticity is superior for discrimination based on parity violation, while others are better at spin determination.Comment: 31 pages, 19 figures. References added, minor modifications made to section

    Remittances and land change: A systematic review

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    Remittances—funds sent by migrants to family and friends back home—are an important source of global monetary flows, and they have implications for the maintenance and transformation of land systems. A number of published reviews have synthesized work on a variety of aspects of remittances (e.g., rural livelihoods, disasters, and economic development). To our knowledge, there are no reviews of work investigating the linkages between remittances and land change, broadly understood. This knowledge gap is important to address because researchers have recognized that remittances flows are a mechanism that helps to explain how migration can affect land change. Thus, understanding the specific roles remittances play in land system changes should help to clarify the multiple processes associated with migration and their independent and interactive effects. To address the state of knowledge about the connection between remittances and land systems, this paper conducts a systematic review. Our review of 51 journal articles finds that the linkages uncovered were commonly subtle and/or indirect. Very few studies looked at the direct connections between receipt of remittances and quantitative changes in land. Most commonly, the relationship between remittances and land change was found to occur through pathways from labor migration to household income to agricultural development and productivity. We find four non-exclusive pathways through which households spend remittances with consequent changes to land systems: (1) agricultural crops and livestock, (2) agricultural labor and technologies, (3) land purchases, and (4) non-agricultural purchases and consumables. In the papers reviewed, these expenditures are linked to various land system change outcomes, including land use change, soil degradation, pasture degradation, afforestation/deforestation/degradation, agricultural intensification/extensification/diversification, and no impact. These findings suggest four avenues for future research. One avenue is the use of the theoretical lens of telecoupling to understand how remittances may produce wider-scale changes in land systems. A second avenue is further examination of the impacts of shocks and disturbances to remittance flows on land change both in migrant sending and in remittance receiving areas. A third avenue is scholarship that examines the extent that household uses of remittances have a “ripple effect” on land uses in nearby interlinked systems. A fourth avenue for future work is the use of spatially explicit modeling that leverages land cover and land use data based on imagery and other geospatial information

    Pellino-1 Regulates the Responses of the Airway to Viral Infection

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    Exposure to respiratory pathogens is a leading cause of exacerbations of airway diseases such as asthma and chronic obstructive pulmonary disease (COPD). Pellino-1 is an E3 ubiquitin ligase known to regulate virally-induced inflammation. We wished to determine the role of Pellino-1 in the host response to respiratory viruses in health and disease. Pellino-1 expression was examined in bronchial sections from patients with GOLD stage two COPD and healthy controls. Primary bronchial epithelial cells (PBECs) in which Pellino-1 expression had been knocked down were extracellularly challenged with the TLR3 agonist poly(I:C). C57BL/6 Peli1-/- mice and wild type littermates were subjected to intranasal infection with clinically-relevant respiratory viruses: rhinovirus (RV1B) and influenza A. We found that Pellino-1 is expressed in the airways of normal subjects and those with COPD, and that Pellino-1 regulates TLR3 signaling and responses to airways viruses. In particular we observed that knockout of Pellino-1 in the murine lung resulted in increased production of proinflammatory cytokines IL-6 and TNFα upon viral infection, accompanied by enhanced recruitment of immune cells to the airways, without any change in viral replication. Pellino-1 therefore regulates inflammatory airway responses without altering replication of respiratory viruses.</p
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