47 research outputs found

    Investing in Cyber Defense: A Value-Focused Analysis of Investment Decisions for Microgrids

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    To mitigate disruptions to commercial power grids, and to achieve operational efficiencies by managing energy use, many organizations are fielding smaller, local, self-contained microgrids. The computer control systems that operate the microgrids create new vulnerabilities to a rapidly-escalating array of cyber attacks. This creates a tension between the need to improve energy assurance and efficiency through microgrids, and the need to protect against cyber attacks that can disrupt and damage the organization\u27s energy systems. Through a series of interviews with subject matter experts and end-users, this exploratory study surfaces the decision-makers\u27 important values in this decision space and develops a network of those values to guide decision-makers to make better decisions in balancing these competing needs

    Estimates of Energy and Prey Requirements of Wolverines

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    Wolverine (Gulo gulo) populations have decreased throughout much of their North American range and there is interest in establishing recovery programs in the Sierra Nevada of California and the Rocky Mountains of Colorado. Determining the sufficiency of prey resources is an important consideration for initiating wolverine recovery, yet there are limited data on resource availability and needs. Our goal is to estimate prey requirements based on wolverine caloric needs and the caloric content of prey likely to be available. We achieve this goal by modifying existing models to account for wolverine biology. Models show a male wolverine requires 5096 kJ/day (2925-7462 kJ) and a female wolverine requires 3645 kJ/day (2158-5439 kJ). This translates to an annual energy budget for males of 1.9 million kJ/yr that could be met by consuming the equivalent of approximately 8 mule deer/yr (Odocoileus hemionus) and 1.4 million kJ/yr for females that could be met by consuming the equivalent of less than 6 mule deer/yr. In light of published records of prey availability, these results suggest populations of wolverines could be sustained where recovery programs are being considered in Colorado and California. We suggest incorporating energetic needs of focal species, such as those calculated here for wolverines, into the assessment of resource availability before implementing recovery programs. Further, these estimates can be applied to management and conservation of wolverines throughtout their range

    How complex do models need to be to predict dispersal of threatened species through matrix habitats?

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    Persistence of species in fragmented landscapes depends on dispersal among suitable breeding sites, and dispersal is often influenced by the "matrix" habitats that lie between breeding sites. However, measuring effects of different matrix habitats on movement and incorporating those differences into spatially explicit models to predict dispersal is costly in terms of time and financial resources. Hence a key question for conservation managers is: Do more costly, complex movement models yield more accurate dispersal predictions? We compared the abilities of a range of movement models, from simple to complex, to predict the dispersal of an endangered butterfly, the Saint Francis' satyr (Neonympha mitchellii francisci). The value of more complex models differed depending on how value was assessed. Although the most complex model, based on detailed movement behaviors, best predicted observed dispersal rates, it was only slightly better than the simplest model, which was based solely on distance between sites. Consequently, a parsimony approach using information criteria favors the simplest model we examined. However, when we applied the models to a larger landscape that included proposed habitat restoration sites, in which the composition of the matrix was different than the matrix surrounding extant breeding sites, the simplest model failed to identify a potentially important dispersal barrier, open habitat that butterflies rarely enter, which may completely isolate some of the proposed restoration sites from other breeding sites. Finally, we found that, although the gain in predicting dispersal with increasing model complexity was small, so was the increase in financial cost. Furthermore, a greater fit continued to accrue with greater financial cost, and more complex models made substantially different predictions than simple models when applied to a novel landscape in which butterflies are to be reintroduced to bolster their populations. This suggests that more complex models might be justifiable on financial grounds. Our results caution against a pure parsimony approach to deciding how complex movement models need to be to accurately predict dispersal through the matrix, especially if the models are to be applied to novel or modified landscapes

    Concentrations of Pro-Inflammatory Cytokines Are Not Associated with Senescence Marker p16INK4a or Predictive of Intracellular Emtricitabine/Tenofovir Metabolite and Endogenous Nucleotide Exposures in Adults with HIV Infection

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    As the HIV-infected population ages, the role of cellular senescence and inflammation on co-morbid conditions and pharmacotherapy is increasingly of interest. p16INK4a expression, a marker for aging and senescence in T-cells, is associated with lower intracellular concentrations of endogenous nucleotides (EN) and nucleos(t)ide reverse transcriptase inhibitors (NRTIs). This study expands on these findings by determining whether inflammation is contributing to the association of p16INK4a expression with intracellular metabolite (IM) exposure and endogenous nucleotide concentrations

    Effect of cytomegalovirus infection on breastfeeding transmission of HIV and on the health of infants born to HIV-infected mothers

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    Cytomegalovirus (CMV) infection can be acquired in utero or postnatally through horizontal transmission and breastfeeding. The effect of postnatal CMV infection on postnatal HIV transmission is unknown

    Evaluating Nurses' Implementation of an Infant-Feeding Counseling Protocol for HIV-Infected Mothers: The Ban Study in Lilongwe, Malawi

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    A process evaluation of nurses’ implementation of an infant-feeding counseling protocol was conducted for the Breastfeeding, Antiretroviral and Nutrition (BAN) Study, a prevention of mother-to-child transmission of HIV clinical trial in Lilongwe, Malawi. Six trained nurses counseled HIV-infected mothers to exclusively breastfeed for 24 weeks postpartum and to stop breastfeeding within an additional four weeks. Implementation data were collected via direct observations of 123 infant feeding counseling sessions (30 antenatal and 93 postnatal) and interviews with each nurse. Analysis included calculating a percent adherence to checklists and conducting a content analysis for the observation and interview data. Nurses were implementing the protocol at an average adherence level of 90% or above. Although not detailed in the protocol, nurses appropriately counseled mothers on their actual or intended formula milk usage after weaning. Results indicate that nurses implemented the protocol as designed. Results will help to interpret the BAN Study’s outcomes

    Adherence to extended postpartum antiretrovirals is associated with decreased breast milk HIV-1 transmission

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    Estimate association between postpartum antiretroviral adherence and breastmilk HIV-1 transmissio

    Plasma Micronutrient Concentrations Are Altered by Antiretroviral Therapy and Lipid-Based Nutrient Supplements in Lactating HIV-Infected Malawian Women

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    Background: Little is known about the influence of antiretroviral therapy with or without micronutrient supplementation on the micronutrient concentrations of HIV-infected lactating women in resource-constrained settings

    The Evolving Private Military Sector: A Survey

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    Proceedings Paper (for Acquisition Research Program)The purpose of this research is to help the US Department of Defense and other government security communities better understand the evolving PM (private military) sector (Avant, 2005; Jager & Kummel, 2007; Singer, 2003). We anticipate our readers will be government agents, members of the international community, or others who wish to make informed decisions regarding the use of PMFs. This report discusses a beginning step in establishing a long-term program of research on the PM sector at NPS. It is expected that knowledge about the sector will be built incrementally through a series of individual studies; no one study will provide a complete picture of the relevant features of the sector. However, we believe a good starting point is to develop quantitative data about the industry, which this report attempts to do. We suggest three reasons why this is an appropriate place to begin.Naval Postgraduate School Acquisition Research ProgramApproved for public release; distribution is unlimited
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