2,769 research outputs found

    GEOGRAFIA HUMANA E DETERMINAÇÃO

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    doi: 10.12957/geouerj.2012.4749   RESUMO A noção de indeterminação e de geografias possíveis possui uma longa história na GeografiaHumana. Ela tem sido pensada em termos de um número de diferentes contrastes típicos,como os de indeterminação/determinação; contingência/necessidade; agenciamento/estrutura;composição/contexto. Este artigo provê, primeiro, uma revisão sobre como a questão foienquadrado desde a revolução quantitativa espacial. Ela procede com os trabalhos iniciais deautores como Hagerstrand e Curry até chegar a trabalhos mais recentes, como sobre odesenvolvimento encaminhado, ou sobre as justaposições de chance de Massey. Ascontinuidades e complementaridades entre estas diferentes abordagens são focalizadas. Oartigo conclui discutindo como se pode pensar a indeterminancia na geografia humana deforma mais defensiva, e como o materialismo histórico geográfico permite nos movermospara além destes binômios. Palavras chave Indeterminancia. Justaposição por chance. Desenvolvimento dependente deencaminhamento. Geografias históricas. Materialismo histórico geográfico. ABSTRACT. The notion of indeterminacy and possible geographies has a long history in human geography.It has typically been thought of in terms of a number of different contrasts:indeterminacy/determinacy; contingent/necessary; agency/structure; composition/context. Inthe first place this paper provides a review of how the question has been framed since thespatial-quantitative revolution. This proceeds from the early works of people like Hagerstrandand Curry through the more recent work on path dependent development and Massey’schance juxtapositions. The continuities and complementarities between these differentapproaches are highlighted. The paper concludes with a discussion of how we might moredefensible think about indeterminacy in human geography and how historical geographicalmaterialism allows us to move beyond these binaries Key Words: indeterminacy; chance juxtaposition; path dependent development; geographicalhistories; historical geographical materialism

    Developing a Suitable Methodology for Integrated Supply Chain Analysis in the Australian Beef Industries: a Research Proposal

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    The Australian Beef Supply Chain is the chain or sequence of all activities from the breeding property to the domestic or overseas consumers. The objective of this research is to describe beef supply chains in Australia and to explore and measure the performance of such chains (i.e. efficiency, effectiveness, and productivity). In addition to this it is to suggest alternative configurations for these supply chains that enhance performance of the businesses concerned and to develop a new design methodology for integrated supply chains based on process modeling, performance analysis and optimization of production and inventory distribution networks

    Tracking Cyber Adversaries with Adaptive Indicators of Compromise

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    A forensics investigation after a breach often uncovers network and host indicators of compromise (IOCs) that can be deployed to sensors to allow early detection of the adversary in the future. Over time, the adversary will change tactics, techniques, and procedures (TTPs), which will also change the data generated. If the IOCs are not kept up-to-date with the adversary's new TTPs, the adversary will no longer be detected once all of the IOCs become invalid. Tracking the Known (TTK) is the problem of keeping IOCs, in this case regular expressions (regexes), up-to-date with a dynamic adversary. Our framework solves the TTK problem in an automated, cyclic fashion to bracket a previously discovered adversary. This tracking is accomplished through a data-driven approach of self-adapting a given model based on its own detection capabilities. In our initial experiments, we found that the true positive rate (TPR) of the adaptive solution degrades much less significantly over time than the naive solution, suggesting that self-updating the model allows the continued detection of positives (i.e., adversaries). The cost for this performance is in the false positive rate (FPR), which increases over time for the adaptive solution, but remains constant for the naive solution. However, the difference in overall detection performance, as measured by the area under the curve (AUC), between the two methods is negligible. This result suggests that self-updating the model over time should be done in practice to continue to detect known, evolving adversaries.Comment: This was presented at the 4th Annual Conf. on Computational Science & Computational Intelligence (CSCI'17) held Dec 14-16, 2017 in Las Vegas, Nevada, US

    Information-Based Physics: An Observer-Centric Foundation

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    It is generally believed that physical laws, reflecting an inherent order in the universe, are ordained by nature. However, in modern physics the observer plays a central role raising questions about how an observer-centric physics can result in laws apparently worthy of a universal nature-centric physics. Over the last decade, we have found that the consistent apt quantification of algebraic and order-theoretic structures results in calculi that possess constraint equations taking the form of what are often considered to be physical laws. I review recent derivations of the formal relations among relevant variables central to special relativity, probability theory and quantum mechanics in this context by considering a problem where two observers form consistent descriptions of and make optimal inferences about a free particle that simply influences them. I show that this approach to describing such a particle based only on available information leads to the mathematics of relativistic quantum mechanics as well as a description of a free particle that reproduces many of the basic properties of a fermion. The result is an approach to foundational physics where laws derive from both consistent descriptions and optimal information-based inferences made by embedded observers.Comment: To be published in Contemporary Physics. The manuscript consists of 43 pages and 9 Figure

    Origin of Complex Quantum Amplitudes and Feynman's Rules

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    Complex numbers are an intrinsic part of the mathematical formalism of quantum theory, and are perhaps its most mysterious feature. In this paper, we show that the complex nature of the quantum formalism can be derived directly from the assumption that a pair of real numbers is associated with each sequence of measurement outcomes, with the probability of this sequence being a real-valued function of this number pair. By making use of elementary symmetry conditions, and without assuming that these real number pairs have any other algebraic structure, we show that these pairs must be manipulated according to the rules of complex arithmetic. We demonstrate that these complex numbers combine according to Feynman's sum and product rules, with the modulus-squared yielding the probability of a sequence of outcomes.Comment: v2: Clarifications, and minor corrections and modifications. Results unchanged. v3: Minor changes to introduction and conclusio

    Calculating the cost of work-related stress and psychosocial risks

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    Work-related stress is expensive. Tackling stress and psychosocial risks can be viewed as too costly, but the reality is that it costs more to ignore them. Stress affects performance and leads to absence from work. If prolonged it may result in serious health problems such as cardiovascular or musculoskeletal diseases. All this comes at a cost. This report summarises the studies focusing on calculating costs of work-related stress and psychosocial risks. The main costs for individuals relate to health impairment, lower income and reduced quality of life. Organisations are affected by costs related to absenteeism, presenteeism, reduced productivity or high staff turnover. Health care costs and poorer business outcomes ultimately affect national economies and society

    Health disparities in aging: Improving dementia care for Black women

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    In the United States, 80% of surveyed Black patients report experiencing barriers to healthcare for Alzheimer\u27s disease and related dementias (ADRD), delaying the time-sensitive treatment of a progressive neurodegenerative disease. According to the National Institute on Aging, Black study participants are 35% less likely to be given a diagnosis of ADRD than white participants, despite being twice as likely to suffer from ADRD than their white counterparts. Prior analysis of prevalence for sex, race, and ethnicity by the Centers for Disease Control indicated the highest incidence of ADRD in Black women. Older (≥65 years) Black women are at a disproportionately high risk for ADRD and yet these patients experience distinct inequities in obtaining clinical diagnosis and treatment for their condition. To that end, this perspective article will review a current understanding of biological and epidemiological factors that underlie the increased risk for ADRD in Black women. We will discuss the specific barriers Black women face in obtaining access to ADRD care, including healthcare prejudice, socioeconomic status, and other societal factors. This perspective also aims to evaluate the performance of intervention programs targeted toward this patient population and offer possible solutions to promote health equity

    Hypoxia-Induced Lysyl Oxidase Is a Critical Mediator of Bone Marrow Cell Recruitment to Form the Premetastatic Niche

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    SummaryTumor cell metastasis is facilitated by “premetastatic niches” formed in destination organs by invading bone marrow-derived cells (BMDCs). Lysyl oxidase (LOX) is critical for premetastatic niche formation. LOX secreted by hypoxic breast tumor cells accumulates at premetastatic sites, crosslinks collagen IV in the basement membrane, and is essential for CD11b+ myeloid cell recruitment. CD11b+ cells adhere to crosslinked collagen IV and produce matrix metalloproteinase-2, which cleaves collagen, enhancing the invasion and recruitment of BMDCs and metastasizing tumor cells. LOX inhibition prevents CD11b+ cell recruitment and metastatic growth. CD11b+ cells and LOX also colocalize in biopsies of human metastases. Our findings demonstrate a critical role for LOX in premetastatic niche formation and support targeting LOX for the treatment and prevention of metastatic disease

    A chemical model of the neutral envelope of the planetary nebula NGC 7027

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    In response to the recent molecular observations by ISO and millimeter-wave telescopes, we have developed a spherically symmetric, steady state chemical model for the planetary nebula NGC 7027. In our model, the neutral envelope consists of a geometrically thin, high-density shell of constant density and an outer stellar wind region with an inverse-square law density profile. The neutral envelope is subjected to ultraviolet (UV) radiation both from the central star and from the external interstellar field. Under an assumed visual extinction of 4 mag for the neutral envelope, the gas in our model is half molecular and half atomic. Simple molecules such as CH, CH +, OH are abundantly formed at an assumed gas temperature of 800 K in the partially molecular shell. The presence of molecular ions such as HCO + and CO + is well explained by photochemistry at high temperatures. The model CN/HCN ratio is almost constant at about 30 throughout the wind region and is 1-10 in the dense shell, comparable to observed values in planetary nebulae. Our model suggests that molecules are as efficiently formed with timescales shorter than 100 yr as they are photodissociated in the neutral envelope of NGC 7027 and probably in other young planetary nebulae.published_or_final_versio
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