1,748 research outputs found

    Verification in Staged Tile Self-Assembly

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    We prove the unique assembly and unique shape verification problems, benchmark measures of self-assembly model power, are coNPNP\mathrm{coNP}^{\mathrm{NP}}-hard and contained in PSPACE\mathrm{PSPACE} (and in Π2sP\mathrm{\Pi}^\mathrm{P}_{2s} for staged systems with ss stages). En route, we prove that unique shape verification problem in the 2HAM is coNPNP\mathrm{coNP}^{\mathrm{NP}}-complete.Comment: An abstract version will appear in the proceedings of UCNC 201

    Forecasting Periods of Strong Southward Magnetic Field Following Interplanetary Shocks

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    Long periods of strong southward magnetic fields are known to be the primary cause of intense geomagnetic storms. The majority of such events are caused by the passage over Earth of a magnetic ejecta. Irrespective of the interplanetary cause, fast-forward shocks often precede such strong southward Bz_{z} periods. Here, we first look at all long periods of strong southward magnetic fields as well as fast-forward shocks measured by the \textit{Wind} spacecraft in a 22.4-year span. We find that 76{\%} of strong southward Bz_{z} periods are preceded within 48 hours by at least a fast-forward shock but only about 23{\%} of all shocks are followed within 48 hours by strong southward Bz_{z} periods. Then, we devise a threshold-based probabilistic forecasting method based on the shock properties and the pre-shock near-Earth solar wind plasma and interplanetary magnetic field characteristics adopting a `superposed epoch analysis'-like approach. Our analysis shows that the solar wind conditions in the 30 minutes interval around the arrival of fast-forward shocks have a significant contribution to the prediction of long-duration southward Bz_{z} periods. This probabilistic model may provide on average a 14-hour warning time for an intense and long-duration southward Bz_{z} period. Evaluating the forecast capability of the model through a statistical and skill score-based approach reveals that it outperforms a coin-flipping forecast. By using the information provided by the arrival of a fast-forward shock at L1, this model represents a marked improvement over similar forecasting methods. We outline a number of future potential improvements.Comment: published in Space Weather, 22 Nov 201

    Scoping Review of Barriers and Facilitators to Recruitment of Black People With Cancer in Biospecimen-Based Research

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    The increasing focus on precision medicine to optimize cancer treatments and improve cancer outcomes is an opportunity to consider equitable engagement of people racialized as Black or African American (B/AA) in biospecimen-based cancer research. B/AA people have the highest cancer incidence and mortality rates compared with all other racial and ethnic groups in the United States, yet are under-represented in biospecimen-based research. A narrative scoping review was conducted to understand the current literature on barriers, facilitators, and evidence-based strategies associated with the engagement of B/AA people with cancer in biospecimen research. Three comprehensive searches of MEDLINE, CINAHL, Embase, and Scopus were conducted. Of 770 studies generated by the search, 10 met all inclusion criteria for this review. The most frequently reported barriers to engagement of B/AA people in biospecimen research were lack of biospecimen research awareness, fear of medical harm, and violation of personal health information privacy, resource constraints, and medical mistrust. Key facilitators included previous exposure to research, knowledge about underlying genetic causes of cancer, and altruism. Recommended strategies to increase participation of B/AA people in biospecimen-based research included community engagement, transparent communication, workforce diversity, education and training, and research participant incentives. Inclusion of B/AA people in biospecimen-based research has the potential to advance the promise of precision oncology for all patients and reduce racial disparities in cancer outcomes

    Contaminants in Coffee Could be Impacting Your Risk for Cardiovascular Disease

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    The purpose of this study is to explore a possible correlation between the consumption of coffee and an individual’s risk with cardiovascular disease. Coffee is an easily accessible stimulant that not many people think of as addictive, however, according to a study done by the Harvard School of Public Health, 54% of Americans over the age of 18 drink ~3.1 cups a day. Coffee/caffeine consumption has been linked to many diseases in epidemiologic studies. However, when looking at it from the atomic level, a contaminant called chlorogenic acid can be found. Recent studies show that this acid interacts with plasma homocysteine levels within the body. Homocysteine is an amino acid and breakdown product of protein metabolism that, when found in high concentrations, is correlated to an increased risk in cardiovascular disease. When in contact, it has been shown that chlorogenic acid raises homocysteine levels in plasma. Albeit causation is difficult to validate, this study observed 107 individuals and a 4 day average of their coffee/caffeine consumption in relation to their current cardiovascular state. A p-value of 0.056 indicated no correlation between these two variables. The individuals were also questioned about their family history of cardiovascular disease. Although nothing significant came from the maternal side, paternal histories of CVD and caffeine consumption had a p-value of ~0.095. While no correlation between the intake of coffee and cardiovascular disease was found, there is hope of future research. Taking a look at the exact contaminants within the coffee and how they interact with cardiovascular disease at a molecular level may be the key to understanding if cutting back on coffee may be the key to cutting back your risk of cardiovascular disease.Ope

    Girls’ and women’s education within Unesco and the World Bank, 1945–2000

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    By 2000, girls’ and women’s education was a priority for international development organisations. While studies have examined the impact of recent campaigns and programmes, there has been less exploration of ideas about girls’ and women’s education within development thought in the immediate post?colonial period, and the political mechanisms through which this came to be a global concern. Through a study of policy documents, this paper investigates how the education of girls and women came to be prioritised within the two principle UN agencies involved with education since 1945, the World Bank and Unesco. A shift in priorities is evident, from ensuring formal rights and improving the status of women, to expanding the productive capacities of women, fertility control and poverty reduction. While the ascendance of human capital theory provided a space for a new perception of the role of women’s education in development, in other policy arenas women’s education was central to exploring more substantive, rights?based notions of gender equality. Ultimately, the goal of improving girls’ and women’s education fitted into diverse development agendas, paving the way for it to become a global development priority
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