4,436 research outputs found

    Underwater optical wireless communications : depth dependent variations in attenuation

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    Depth variations in the attenuation coefficient for light in the ocean were calculated using a one-parameter model based on the chlorophyll-a concentration Cc and experimentally-determined Gaussian chlorophyll-depth profiles. The depth profiles were related to surface chlorophyll levels for the range 0–4  mg/m2, representing clear, open ocean. The depth where Cc became negligible was calculated to be shallower for places of high surface chlorophyll; 111.5 m for surface chlorophyll 0.8<Cc<2.2  mg/m3 compared with 415.5 m for surface Cc<0.04  mg/m3. Below this depth is the absolute minimum attenuation for underwater ocean communication links, calculated to be 0.0092  m−1 at a wavelength of 430 nm. By combining this with satellite surface-chlorophyll data, it is possible to quantify the attenuation between any two locations in the ocean, with applications for low-noise or secure underwater communications and vertical links from the ocean surface

    GENDER DISCRIMINATION AND TITLE IX IMPLEMENTATION: LESSONS FROM THE OFFICE FOR CIVIL RIGHTS RESOLUTION LETTERS 1997-2011

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    Gender discrimination, such as sexual harassment, sexual assault and inequitable treatment has long been considered a prominent issue on higher education campuses and is regulated under the Patsy Takemoto Mink Equal Opportunity in Education Act, commonly known as Title IX. Title IX is enforced by the Department of Education’s Office for Civil Rights (OCR) who responds to gender discrimination complaints on campus through investigations resulting in what are called OCR Resolution Letters. These letters define numerous policies and procedures Institutions of Higher Education (IHE) must put in place pertaining to the prevention of gender discrimination. This qualitative study looks specifically at the ways that gender discrimination on campuses of higher education was defined by the OCR from 1997-2011. The study explores the research questions (1) How have the types of conduct determined to be gender discrimination changed over time? (2) How have expectations of IHE responsibilities for gender discrimination issues changed over time? and (3) What gender discrimination issues have surfaced as priorities in the implementation of Title IX, as reflected in OCR resolution letters? Analysis of the letters using a social construction framework demonstrates that while the definitions of specific types of gender discrimination remained constant, the context in which they occur and the types of behaviors determined to be gender discrimination have both expanded in response to societal attitudes. The OCR tends to take the stance of being an ally vs. a punishing body when aiding IHEs in implementing Title IX; however IHE’s required investment in addressing the problem in both response and preventive measures has grown. Finally, OCR Resolution letters demonstrate that student on student interactions have been less common than faculty on student interactions. Implications for IHE practices and future research are discussed

    Frontier of Injustice: Alaska Native Victims of Domestic Violence

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    Frontier of Injustice: Alaska Native Victims of Domestic Violence

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    Matrix attachment regions as targets for retroviral integration

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    BACKGROUND: The randomness of retroviral integration has been debated for many years. Recent evidence indicates that integration site selection is not random, and that it is influenced by both viral and cellular factors. To study the role of DNA structure in site selection, retroviral integration near matrix attachment regions (MARs) was analyzed for three different groups of retroviruses. The objective was to assess whether integration near MARs may be a factor for integration site selection. RESULTS: Results indicated that MLV, SL3-3 MuLV, HIV-1 and HTLV-1 integrate preferentially near MARs, specifically within 2-kilobases (kb). In addition, a preferential position and orientation relative to the adjacent MAR was observed for each virus. Further analysis of SL3-3 MuLV insertions in common integration sites (CISs) demonstrated a higher frequency of integration near MARs and an orientation preference that was not observed for integrations outside CISs. CONCLUSION: These findings contribute to a growing body of evidence indicating that retroviral integration is not random, that MARs influence integration site selection for some retroviruses, and that integration near MARs may have a role in the insertional activation of oncogenes by gammaretroviruses

    Toxoplasmosis in a patient who was immunocompetent: a case report

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    <p>Abstract</p> <p>Introduction</p> <p><it>Toxoplasma gondii </it>is an obligate intracellular protozoan that infects up to one-third of the world's population. Although this case is not the first of its kind, it is clinically important since it will help doctors keep a broad differential diagnosis in mind when attending to similar patients.</p> <p>Case presentation</p> <p>We present the case of a 20-year-old man of Middle Eastern heritage presenting with only generalized lymphadenopathy who was diagnosed with acute toxoplasmosis.</p> <p>Conclusion</p> <p>This case illustrates the important fact that toxoplasmosis can present with just simple lymphadenopathy, and thus can be confused with other infections such as Epstein-Barr virus and other mononucleosis-like illnesses such as cytomegalovirus, HIV with acute retroviral syndrome, cat scratch disease, leishmaniasis and syphilis. This case underlines why appropriate testing should be performed in confusing cases, and helps increase the knowledge about the diagnosis of this disease.</p

    Developing an Explicit Instruction Special Education Teacher Observation Rubric

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    In this study, we developed an Explicit Instruction special education teacher observation rubric that details the elements of explicit instruction, and tested its psychometric properties using many-faceted Rasch measurement (MFRM). Video observations of classroom instruction from 30 special education teachers across three states were collected. External raters (n = 15) were trained to observe and evaluate instruction using the rubric, and assigned scores of ‘implemented’, ‘partially implemented’ or ‘not implemented’ for each of the items. Analyses showed that the item, teacher, lesson and rater facets achieved high psychometric quality for the instrument. Implications for research and practice are discussed

    A Rigorous Approach to the Feynman-Vernon Influence Functional and its Applications. I

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    A rigorous representation of the Feynman-Vernon influence functional used to describe open quantum systems is given, based on the theory of infinite dimensional oscillatory integrals. An application to the case of the density matrices describing the Caldeira-Leggett model of two quantum systems with a quadratic interaction is treated

    Cultivating Compassion and Youth Action Around the Globe: A Preliminary Report on Jane Goodall’s Roots & Shoots Program

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    This paper describes a unique service-learning based environmental and humanitarian program for youth, The Jane Goodall Institute’s Roots and Shoots program (R&S). R&S aims to foster learning, personal growth and civic engagement among youth members through service activities and environmental education. Despite its promise as a youth development program and its rapid expansion into 100 countries, little is known about R&S’s impact on youth development. In this study, we explore R&S programs in China and Tanzania, two countries that are maximally different from the U.S. in important cultural and contextual factors. Through qualitative and quantitative methods we describe the programs, their practices, and perceptions of their impact on youths’ personal and social development (cognitive and social competence, leadership, self-efficacy, citizenship and social responsibility). Additionally, we highlight the importance of sociocultural and ecological factors when developing and evaluating youth programs
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