1,008 research outputs found

    Gap distribution of Farey fractions under some divisibility constraints

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    For a fixed positive integer d, we show the existence of the limiting gap distribution measure for the sets of Farey fractions a/q of order Q with a not divisible by d, and respectively with q relatively prime with d, as Q tends to infinity.Comment: 15 pages, revised versio

    Young people and sexting in Australia: ethics, representation and the law

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    The Young People and Sexting in Australia report presents the findings of a qualitative study of young people’s understandings of, and responses to, current Australian laws, media and educational resources that address sexting. The project, led by Dr Kath Albury involved a review of both international local and academic research as well as popular media addressing sexting, and a review of educational resources for young people. Three focus groups were conducted with young people aged 16 and 17 in 2012, and a working paper based on those findings was then distributed to adult stakeholders in the fields of law enforcement, youth and children’s legal support, education, criminology, media and communications, youth work, youth health care, counseling and youth health promotion

    Neuregulin 1-Beta cytoprotective role in AML 12 mouse hepatocytes exposed to pentachlorophenol.

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    Neuregulins are a family of growth factor domain proteins that are structurally related to the epidermal growth factor. Accumulating evidence has shown that neuregulins have cyto- and neuroprotective properties in various cell types. In particular, the neuregulin-1 Beta (NRG1-Beta) isoform is well documented for its antiinflammatory properties in rat brain after acute stroke episodes. Pentachlorophenol (PCP) is an organochlorine compound that has been widely used as a biocide in several industrial, agricultural, and domestic applications. Previous investigations from our laboratory have demonstrated that PCP exerts both cytotoxic and mitogenic effects in human liver carcinoma (HepG2) cells, primary catfish hepatocytes and AML 12 mouse hepatocytes. We have also shown that in HepG2 cells, PCP has the ability to induce stress genes that may play a role in the molecular events leading to toxicity and tumorigenesis. In the present study, we hypothesize that NRG1-Beta will exert its cytoprotective effects in PCP-treated AML 12 mouse hepatocytes by its ability to suppress the toxic effects of PCP. To test this hypothesis, we performed the MTT-cell respiration assay to assess cell viability, and Western-blot analysis to assess stress-related proteins as a consequence of PCP exposure. Data obtained from 48 h-viability studies demonstrated a biphasic response; showing a dose-dependent increase in cell viability within the range of 0 to 3.87 microg/mL, and a gradual decrease within the concentration range of 7.75 to 31.0 microg/mL in concomitant treatments of NRG1-Beta+PCP and PCP. Cell viability percentages indicated that NRG1-Beta+PCPtreated cells were not significantly impaired, while PCP-treated cells were appreciably affected; suggesting that NRG1-Beta has the ability to suppress the toxic effects of PCP. Western Blot analysis demonstrated the potential of PCP to induce oxidative stress and inflammatory response (c-fos), growth arrest and DNA damage (GADD153), proteotoxic effects (HSP70), cell cycle arrest as consequence of DNA damage (p53), mitogenic response (cyclin- D1), and apoptosis (caspase-3). NRG1-Beta exposure attenuated stress-related protein expression in PCP-treated AML 12 mouse hepatocytes. Here we provide clear evidence that NRG1-Beta exerts cytoprotective effects in AML 12 mouse hepatocytes exposed to PCP

    Los efectos de la asistencia externa sobre el crecimiento y otras variables en América Latina

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    Aborda el desarrollo económico de América Latina y las estrategias que se deben considerar para lograr el objetivo de que la economía se fortalezca a nivel regional.Trabajo de investigació

    The ingenuity of common workmen: and the invention of the computer

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    Since World War II, state support for scientific research has been assumed crucial to technological and economic progress. Governments accordingly spent tremendous sums to that end. Nothing epitomizes the alleged fruits of that involvement better than the electronic digital computer. The first such computer has been widely reputed to be the ENIAC, financed by the U.S. Army for the war but finished afterwards. Vastly improved computers followed, initially paid for in good share by the Federal Government of the United States, but with the private sector then dominating, both in development and use, and computers are of major significance.;Despite the supposed success of public-supported science, evidence is that computers would have evolved much the same without it but at less expense. Indeed, the foundations of modern computer theory and technology were articulated before World War II, both as a tool of applied mathematics and for information processing, and the computer was itself on the cusp of reality. Contrary to popular understanding, the ENIAC actually represented a movement backwards and a dead end.;Rather, modern computation derived more directly, for example, from the prewar work of John Vincent Atanasoff and Clifford Berry, a physics professor and graduate student, respectively, at Iowa State College (now University) in Ames, Iowa. They built the Atanasoff Berry Computer (ABC), which, although special purpose and inexpensive, heralded the efficient and elegant design of modern computers. Moreover, while no one foresaw commercialization of computers based on the ungainly and costly ENIAC, the commercial possibilities of the ABC were immediately evident, although unrealized due to war. Evidence indicates, furthermore, that the private sector was willing and able to develop computers beyond the ABC and could have done so more effectively than government, to the most sophisticated machines.;A full and inclusive history of computers suggests that Adam Smith, the eighteenth century Scottish philosopher, had it right. He believed that minimal and aloof government best served society, and that the inherent genius of citizens was itself enough to ensure the general prosperity

    Flirting and friendship at the periphery of hook-up app research

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    &#x0D; &#x0D; &#x0D; The everyday intimacies of friendship and flirting are not typically exploredin hook-up app research, nor is there much reflection on the intimacies of researching these media. This paper considers flirting and friendship as practices and methods that broaden the scope of current hook-up app research. We ask what these intimacies can produce to expand research approaches (and thus knowledge) of hook-up apps. As users and researchers of these apps, we consider negotiations of flirting and friendship between researchers and research partici- pants by exploring what it means to research with intimacy. Attention is given to the connections, conversations, and intimate encounters within hook-up research that are mostly absent from existing presentations of research findings. We sug- gest that greater attention to peripheral and intimate communication between researchers and participants can offer valuable methods for queering otherwise stabilised ways of knowing, using, and researching these platforms. Adding to the queer ethnographic tradition, we demonstrate how a processual and affective approach to hook-up app use encourages researchers to make visible our connec- tions to the media we research, and how these connections relate to the intima- cies that hook-up apps foster.&#x0D; &#x0D; &#x0D; </jats:p

    Spatial distribution of energy deposited in nitrogen by electrons

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    The spatial distribution of the energy deposited by kilovolt electrons moving through gaseous molecular nitrogen was measured. The range of electrons of initial energy 300 eV to 5 keV was obtained and can be expressed by the formula R=K1+K2EA1−K3EA2, where R is the range, E is the initial energy of the electrons, and Ki,Ai are constants. The range, in this energy interval, is greater than that determined by previous measurements. A source of error, not previously discussed, is considered. The energy region (above 1 keV) where the simpler expression R=KEA holds is discussed. It is shown that this is the energy region where the energy and range dependence of the energy deposition curve can be removed and a normalized, characteristic energy deposition curve λ can be obtained. The efficiency of conversion of electron energy at 1 keV and 280 ÎŒ pressure to energy of photons at 3914 Å was measured to be (0.28±0.03) %.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69995/2/JCPSA6-64-2-743-1.pd

    Practicing sexual health: young people, sexual knowingness, and everyday intimacies

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    This thesis presents a discursive analysis of young people’s sexual health in contemporary Australia, engaging with data from health promotion, social sciences, and interviews with young people. Data comprises: Australian sexual health websites for young people (N=3); research papers on young people and chlamydia in Australia, published from 2005-2009 (N=18); and interviews with young people aged 18-25, from Sydney (N=12). Using Michel de Certeau’s theory of everyday practice (1988), I explore young people’s experiences and knowledges of sexual health and how these exceed formal health understandings. I demonstrate how risk-based approaches typically deny young people’s sexual health competencies and dismiss the value of friendship and social networks. I propose revision of this deficit understanding of young people through an everyday practice based approach to sexual health. This differs from behavioural science approaches that can abstract young people’s sex practices from the context of their socio-sexual relations. Considering young people’s competencies and tactics in negotiating sex, I argue that these can inform health promotion strategies, making them more relevant and useful to young people. Early chapters analyse discourses of young people’s experience, risk and knowledge in these data, as key terms that justify young people’s inclusion in Australian sexual health policy. Later chapters explore discourses of pleasure and intimacies, including friendship intimacies. These commonly feature in interview data where participants’ stories highlight the spatial aspects of sex practices and negotiations. These often extend beyond sexual scenarios and into friendships. My thesis demonstrates how young people’s negotiations of safety encompass and exceed formal notions of ‘safe sex’, and draws a parallel between negotiations of safety and pleasure. I argue that a focus on safety is more useful than risk-based approaches, as it incorporates shared values of young people, health promotion, and sexual health research. Young people do not share a deficit understanding of their skills and practices, but are invested in sexual safeties, with common interview discussions of intimacy and its affordances. Finally, a case study of young people’s social media practices is presented, further highlighting friendship’s value to young people’s sexual health negotiations
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