328 research outputs found

    The Spatial Dynamics of High School Dropout: The Case of Rural Louisiana

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    This study uses data from the Louisiana Department of Education to conduct a spatial analysis of high school dropout. The paper suggests school-level factors influence dropout rates not only within their schools, but also more widely across schools in close proximity. These claims are tested in two distinct ways: (1) by comparing spatial cluster maps of dropout to measures of school processes, effectiveness, and structure and (2) by conducting spatial regression analysis to test whether spatial influences remain after considering school-level predictors of dropout. The findings show school processes, effectiveness, and structure all influence dropout rates. Moreover, findings demonstrate spatial patterns in rural high school dropout in Louisiana, suggesting the mechanisms driving dropout extend beyond the school level. These mechanisms may be related to rural labor market structures. Future research should focus more specifically on the link between shifting rural labor markets and high school outcome

    Vandenberg Air Force Base Upper Level Wind Launch Weather Constraints

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    The 30th Operational Support Squadron Weather Flight (30 OSSWF) provides comprehensive weather services to the space program at Vandenberg Air Force Base (VAFB) in California. One of their responsibilities is to monitor upper-level winds to ensure safe launch operations of the Minuteman III ballistic missile. The 30 OSSWF tasked the Applied Meteorology Unit (AMU) to analyze VAFB sounding data with the goal of determining the probability of violating (PoV) their upper-level thresholds for wind speed and shear constraints specific to this launch vehicle, and to develop a tool that will calculate the PoV of each constraint on the day of launch. In order to calculate the probability of exceeding each constraint, the AMU collected and analyzed historical data from VAFB. The historical sounding data were retrieved from the National Oceanic and Atmospheric Administration Earth System Research Laboratory archive for the years 1994-2011 and then stratified into four sub-seasons: January-March, April-June, July-September, and October-December. The maximum wind speed and 1000-ft shear values for each sounding in each subseason were determined. To accurately calculate the PoV, the AMU determined the theoretical distributions that best fit the maximum wind speed and maximum shear datasets. Ultimately it was discovered that the maximum wind speeds follow a Gaussian distribution while the maximum shear values follow a lognormal distribution. These results were applied when calculating the averages and standard deviations needed for the historical and real-time PoV calculations. In addition to the requirements outlined in the original task plan, the AMU also included forecast sounding data from the Rapid Refresh model. This information provides further insight for the launch weather officers (LWOs) when determining if a wind constraint violation will occur over the next few hours on day of launch. The interactive graphical user interface (GUI) for this project was developed in Microsoft Excel using Visual Basic for Applications. The GUI displays the critical sounding data easily and quickly for the LWOs on day of launch. This tool will replace the existing one used by the 30 OSSWF, assist the LWOs in determining the probability of exceeding specific wind threshold values, and help to improve the overall upper winds forecast for the launch customer

    The role of scientists and scientific information in public policy decisions: The case of drought planning.

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    In addition to general interaction between the two communities, differences within elements of the communities also are highlighted. Scientists interact with policy-makers and the public at-large through several different roles, driven by their perceptions of how information is used in the policy process and their style of engagement. Policy-makers were found to have different roles, determined principally by their location in the state organizational hierarchy.The study was conducted between the summer of 2004 and spring of 2005. More than fifty individuals, representing both the scientific and state-level policy communities, were interviewed. Questions focused upon how scientists conducted and communicated their research, and information sources upon which policy-makers draw advice on creating state drought plans. The study uses a communications model, consisting of a sender (scientists), a message, and a receiver (policy-makers). An additional component, intermediary organizations and technical staff that help to integrate and reformat information, is included. This communication process takes place in an environment filled with competing messages, often detached from their sources, and noise.Does a cultural divide separate scientists from the broader community in which they live? This concept, proposed by C. P. Snow in 1964, has driven studies and reform movements within the scientific community for more than two decades. Calls to make science more relevant and to bridge barriers have been made. This study explores the concept of a cultural divide in the context of drought policy. Its goal is to examine whether such a cultural divide exists and if so, what mechanisms facilitate interaction across this divide.Findings suggest that these intermediary organizations are a key component in facilitating interaction between the two communities. Scientists, intermediary organizations, and technical staff from state agencies operate together in knowledge communities, in which information is shared for development of state policy. Scientific and technical information is integrated and formatted for easy access and inclusion into the state drought policy-making process. Scientists were willing to fashion information into usable contexts and policy-makers had little difficulty accessing or using information.This process has been effective at getting scientific information into plans, but has yet to yield many instances of successful implementation. Much of the scientists' involvement focuses on aspects of monitoring drought conditions. This is largely a technical question and avoids many of the difficult normative issues involved in mitigating exposure to drought. Because of this, state drought plans have improved in their abilities to serve as early-warning indicators, but have not yielded substantive changes in community behavior. In order to bridge the implementation barrier, scientists must become more involved in addressing the normative aspects of drought management

    Inverted orbital polarization in strained correlated oxide films

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    Manipulating the orbital occupation of valence electrons via epitaxial strain in an effort to induce new functional properties requires considerations of how changes in the local bonding environment affect the band structure at the Fermi level. Using synchrotron radiation to measure the x-ray linear dichroism of epitaxially strained films of the correlated oxide CaFeO3, we demonstrate that the orbital polarization of the Fe valence electrons is opposite from conventional understanding. Although the energetic ordering of the Fe 3d orbitals is confirmed by multiplet ligand field theory analysis to be consistent with previously reported strain-induced behavior, we find that the nominally higher energy orbital is more populated than the lower. We ascribe this inverted orbital polarization to an anisotropic bandwidth response to strain in a compound with nearly filled bands. These findings provide an important counterexample to the traditional understanding of strain-induced orbital polarization and reveal a new method to engineer otherwise unachievable orbital occupations in correlated oxides

    Neither dust nor black carbon causing apparent albedo decline in Greenland\u27s dry snow zone: Implications for MODIS C5 surface reflectance

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    Remote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light-absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving melt events. Analysis of Collection 5 Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data indicates that the decline and spectral shift in dry snow albedo contains important contributions from uncorrected Terra sensor degradation. Though discrepancies are mostly below the stated accuracy of MODIS products, they will require revisiting some prior conclusions with C6 data

    Juvenile Probation Officers Call for a New Response to Teen Drug and Alcohol Use and Dependency

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    Shares lessons learned from RWJF's Reclaiming Futures initiative from a juvenile justice practitioner's perspective. Discusses the need to reform the system's treatment services, the challenges faced at the ten project sites, and recommendations

    Copper(II)-Bis(Thiosemicarbazonato) Complexes as Antibacterial Agents: Insights into Their Mode of Action and Potential as Therapeutics

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    There is increasing interest in the use of lipophilic copper (Cu)-containing complexes to combat bacterial infections. In this work, we showed that Cu complexes with bis(thiosemicarbazone) ligands [Cu(btsc)] exert antibacterial activity against a range of medically significant pathogens. Previous work using Neisseria gonorrhoeae showed that Cu(btsc) complexes may act as inhibitors of respiratory dehydrogenases in the electron transport chain. We now show that these complexes are also toxic against pathogens that lack a respiratory chain. Respiration in Escherichia coli was slightly affected by Cu(btsc) complexes, but our results indicate that, in this model bacterium, the complexes act primarily as agents that deliver toxic Cu ions efficiently into the cytoplasm. Although the chemistry of Cu(btsc) complexes may dictate their mechanism of action, their efficacy depends heavily on bacterial physiology. This is linked to the ability of the target bacterium to tolerate Cu and, additionally, the susceptibility of the respiratory chain to direct inhibition by Cu(btsc) complexes. The physiology of N. gonorrhoeae, including multidrug-resistant strains, makes it highly susceptible to damage by Cu ions and Cu(btsc) complexes, highlighting the potential of Cu(btsc) complexes (and Cu-based therapeutics) as a promising treatment against this important bacterial pathogen

    Drought-Ready Communities: A Guide to Community Drought Preparedness

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    Table of Contents Introduction to Drought-Ready Communities........................................................ 4 Section 1. Getting Started: Invite the Community to Participate, Commit to the Process...................... 7 1.1 Establish a leadership team that includes individuals with responsibility for monitoring, communication, and implementation .............................................. 7 1.2 Identify stakeholders or groups in the community that may need additional resources to participate in the Drought-Ready Communities process .................... 8 1.3 Include government agencies and regulators ....................................... 9 1.4 Develop a contact list ................................................................ 9 1.5 Gather community perceptions of drought .................................................. 10 Section 2. Information Gathering: Understand Water Sources and Uses, Develop a Drought History . 11 2.1 Identify water sources and uses ....................................................... 11 2.2 Learn how drought has affected the community in the past ........................ 12 2.3 Gather data on water and climate ................................................................. 13 2.4 List factors that affect the severity of drought impacts ..................................... 1

    HIV-1 Protease, Reverse Transcriptase, and Integrase Variation

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    ABSTRACT HIV-1 protease (PR), reverse transcriptase (RT), and integrase (IN) variability presents a challenge to laboratories performing genotypic resistance testing. This challenge will grow with increased sequencing of samples enriched for proviral DNA such as dried blood spots and increased use of next-generation sequencing (NGS) to detect low-abundance HIV-1 variants. We analyzed PR and RT sequences from >100,000 individuals and IN sequences from >10,000 individuals to characterize variation at each amino acid position, identify mutations indicating APOBEC-mediated G-to-A editing, and identify mutations resulting from selective drug pressure. Forty-seven percent of PR, 37% of RT, and 34% of IN positions had one or more amino acid variants with a prevalence of ≥1%. Seventy percent of PR, 60% of RT, and 60% of IN positions had one or more variants with a prevalence of ≥0.1%. Overall 201 PR, 636 RT, and 346 IN variants had a prevalence of ≥0.1%. The median intersubtype prevalence ratios were 2.9-, 2.1-, and 1.9-fold for these PR, RT, and IN variants, respectively. Only 5.0% of PR, 3.7% of RT, and 2.0% of IN variants had a median intersubtype prevalence ratio of ≥10-fold. Variants at lower prevalences were more likely to differ biochemically and to be part of an electrophoretic mixture compared to high-prevalence variants. There were 209 mutations indicative of APOBEC-mediated G-to-A editing and 326 mutations nonpolymorphic treatment selected. Identification of viruses with a high number of APOBEC-associated mutations will facilitate the quality control of dried blood spot sequencing. Identifying sequences with a high proportion of rare mutations will facilitate the quality control of NGS. IMPORTANCE Most antiretroviral drugs target three HIV-1 proteins: PR, RT, and IN. These proteins are highly variable: many different amino acids can be present at the same position in viruses from different individuals. Some of the amino acid variants cause drug resistance and occur mainly in individuals receiving antiretroviral drugs. Some variants result from a human cellular defense mechanism called APOBEC-mediated hypermutation. Many variants result from naturally occurring mutation. Some variants may represent technical artifacts. We studied PR and RT sequences from >100,000 individuals and IN sequences from >10,000 individuals to quantify variation at each amino acid position in these three HIV-1 proteins. We performed analyses to determine which amino acid variants resulted from antiretroviral drug selection pressure, APOBEC-mediated editing, and naturally occurring variation. Our results provide information essential to clinical, research, and public health laboratories performing genotypic resistance testing by sequencing HIV-1 PR, RT, and IN

    Evaluating the cytotoxicity of innate immune effector cells using the GrB ELISPOT assay

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    BACKGROUND: This study assessed the Granzyme B (GrB) ELISPOT as a viable alternative to the (51)Cr-release assay for measuring cytotoxic activity of innate immune effector cells. We strategically selected the GrB ELISPOT assay because GrB is a hallmark effector molecule of cell-mediated destruction of target cells. METHODS: We optimized the GrB ELISPOT assay using the human-derived TALL-104 cytotoxic cell line as effectors against K562 target cells. Titration studies were performed to assess whether the ELISPOT assay could accurately enumerate the number of GrB-secreting effector cells. TALL-104 were treated with various secretion inhibitors and utilized in the GrB ELISPOT to determine if GrB measured in the ELISPOT was due to degranulation of effector cells. Additionally, CD107a expression on effector cells after effector-target interaction was utilized to further confirm the mechanism of GrB release by TALL-104 and lymphokine-activated killer (LAK) cells. Direct comparisons between the GrB ELISPOT, the IFN-γ ELISPOT and the standard (51)Cr-release assays were made using human LAK cells. RESULTS: Titration studies demonstrated a strong correlation between the number of TALL-104 and LAK effector cells and the number of GrB spots per well. GrB secretion was detectable within 10 min of effector-target contact with optimal secretion observed at 3–4 h; in contrast, optimal IFN-γ secretion was not observed until 24 h. The protein secretion inhibitor, brefeldin A, did not inhibit the release of GrB but did abrogate IFN-γ production by TALL-104 cells. GrB secretion was abrogated by BAPTA-AM (1,2-bis-(2-aminophenoxy)ethane-N,N,N', N'-tetraacetic acid tetra(acetoxymethyl) ester), which sequesters intracellular Ca(2+), thereby preventing degranulation. The number of effector cells expressing the degranulation associated glycoprotein CD107a increased after interaction with target cells and correlated with the stimulated release of GrB measured in the ELISPOT assay. CONCLUSIONS: Because of its high sensitivity and ability to estimate cytotoxic effector cell frequency, the GrB ELISPOT assay is a viable alternative to the (51)Cr-release assay to measure MHC non-restricted cytotoxic activity of innate immune cells. Compared to the IFN-γ ELISPOT assay, the GrB ELISPOT may be a more direct measure of cytotoxic cell activity. Because GrB is one of the primary effector molecules in natural killer (NK) cell-mediated killing, detection and enumeration of GrB secreting effector cells can provide valuable insight with regards to innate immunological responses
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