427 research outputs found

    Talented, Yet Seen With Suspicion: Surveillance of International Students and Scholars in the United States

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    The attacks of September 11, 2001, put terrorism at the forefront of the American political landscape. Donald Trump played into these fears of terrorism through his political rhetoric during his presidency, particularly targeting international students as “threats” to the nation. However, we argue that the labeling of international students as security threats was not started after 9/11 nor invented by Trump. Through historical records and accounts across decades of policies related to this issue, we seek to answer two questions: How has the U.S. government monitored visa policies and programs for international students? How have U.S. national policies evolved to view international students as national security threats? We find that mistrust of this population has been embedded throughout U.S. immigration history and that federal tracking policies emerged incrementally from long-held security concerns. We discuss why the entire population of international students should not be scapegoated due to fear

    Spontaneous Charging of Drops on Lubricant-Infused Surfaces

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    [Image: see text] When a drop of a polar liquid slides over a hydrophobic surface, it acquires a charge. As a result, the surface charges oppositely. For applications such as the generation of electric energy, lubricant-infused surfaces (LIS) may be important because they show a low friction for drops. However, slide electrification on LIS has not been studied yet. Here, slide electrification on lubricant-infused surfaces was studied by measuring the charge generated by series of water drops sliding down inclined surfaces. As LIS, we used PDMS-coated glass with micrometer-thick silicone oil films on top. For PDMS-coated glass without lubricant, the charge for the first drop is highest. Then it decreases and saturates at a steady state charge per drop. With lubricant, the drop charge starts from 0, then it increases and reaches a maximum charge per drop. Afterward, it decreases again before reaching its steady-state value. This dependency is not a unique phenomenon for lubricant-infused PDMS; it also occurs on lubricant-infused micropillar surfaces. We attribute this dependency of charge on drop numbers to a change in surface conductivity and depletion of lubricant. These findings are helpful for understanding the charge process and optimizing solid–liquid nanogenerator devices in applications

    Mortality among young people seeking residential treatment for problematic drug and alcohol use: A data linkage study.

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    Background Young people with problematic alcohol and other drug (AOD) use are often referred to residential treatment. Subsequent mortality rates among this high-risk group is not known. This study estimates mortality rates and determines causes of death amongst young people referred to residential treatment in Sydney, Australia. Design Retrospective data linkage study. Data of young people (13–18 years) referred to a residential treatment service 2001–2015 (n = 3256) linked with Australian death registration data, and followed up to 16 years (2001–2016). Methods Mortality rates (CMRs) and standardised mortality ratios (SMRs, age-, gender-, calendar-year-adjusted) calculated using population mortality rates. Causes of death were analysed using ICD-10 codes for AOD-induced, AOD as contributory and non-AOD related causes. Results During follow-up of the cohort (28,838 person-years), 63 people died (71.4 % males; 48 % Indigenous; median age at death = 21.9 years; median follow-up = 5.1years), with 76 % dying before aged 25 years. Overall mortality (SMR = 4.91, 95 % CI: 3.8−6.2; CMR = 2.18/1000 person-years, 95 % CI: 1.7−2.8) was significantly higher than age-gender-matched general population, particularly in females (SMR = 9.55; males: SMR = 4.11; RR: 2.3, 95 % CI: 1.3–4.1). SMRs were not significantly different between treatment groups (SMRs>5.5) and non-attend group (SMR = 3.7) (p = 0.359). Two-thirds of deaths involved AOD, with AOD-induced deaths comprising 42 % and AOD as contributory for 22 % deaths. Overdose, mainly opioids (including opiates), suicide, and transport accidents were major causes of deaths. Conclusion Very high mortality rates, particularly among females, and the high incidence of overdose and suicide emphasise early screening for those at high-risk, targeted and culturally appropriate interventions, and maximised continuing after-care accessible to young people

    Charging of drops impacting onto superhydrophobic surfaces

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    When neutral water drops impact and rebound from superhydrophobic surfaces, they acquire a positive electrical charge. To measure the charge, we analyzed the trajectory of rebounding drops in an external electric field by high-speed video imaging. Although this charging phenomenon has been observed in the past, little is known about the controlling parameters for the amount of drop charging. Here we investigate the relative importance of five of these potential variables: impact speed, drop contact area, contact line retraction speed, drop size, and type of surface. We additionally apply our previously reported model for sliding drop electrification to the case of impacting drops, suggesting that the two cases contain the same charge separation mechanism at the contact line. Both our experimental results and our theoretical model indicate that maximum contact area is the dominant control parameter for charge separation

    Impact of air pollution on global burden of disease in 2019

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    Air pollution consisting of ambient air pollution and household air pollution (HAP) threatens health globally. Air pollution aggravates the health of vulnerable people such as infants, children, women, and the elderly as well as people with chronic diseases such as cardiorespiratory illnesses, little social support, and poor access to medical services. This study is aimed to estimate the impact of air pollution on global burden of disease (GBD). We extracted data about mortality and disability adjusted life years (DALYs) attributable to air pollution from 1990 to 2019. The extracted data were then organized and edited into a usable format using STATA version 15. Furthermore, we also estimated the impacts for three categories based on their socio-demographic index (SDI) as calculated by GBD study. The impacts of air pollution on overall burden of disease by SDI, gender, type of pollution, and type of disease is estimated and their trends over the period of 1990 to 2019 are presented. The attributable burden of ambient air pollution is increasing over the years while attributable burden of HAP is declining over the years, globally. The findings of this study will be useful for evidence-based planning for prevention and control of air pollution and reduction of burden of disease from air pollution at global, regional, and national levels

    Exploiting transient protein states for the design of small-molecule stabilizers of mutant p53

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    The destabilizing p53 cancer mutation Y220C creates an extended crevice on the surface of the protein that can be targeted by small-molecule stabilizers. Here, we identify different classes of small molecules that bind to this crevice and determine their binding modes by X-ray crystallography. These structures reveal two major conformational states of the pocket and a cryptic, transiently open hydrophobic subpocket that is modulated by Cys220. In one instance, specifically targeting this transient protein state by a pyrrole moiety resulted in a 40-fold increase in binding affinity. Molecular dynamics simulations showed that both open and closed states of this subsite were populated at comparable frequencies along the trajectories. Our data extend the framework for the design of high-affinity Y220C mutant binders for use in personalized anticancer therapy and, more generally, highlight the importance of implementing protein dynamics and hydration patterns in the drug-discovery process

    The double pendulum

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    Policy discourses posit an accountability deficit as an underlying cause of a “learning crisis” in many low-income countries. Many studies understand this perceived deficit from a principal-agent perspective, arguing that incentives facing teachers and schools often do not align to the interests of parents and students. Such perspectives underlie many randomized controlled trials, which associate interventions with outcomes, but which also produce varying or inconsistent results across contexts. This paper seeks to study the accountability of schools and teachers more directly, looking at how it varies across public and private schools and how it relates to students’ literacy and numeracy abilities. We report results from a mixed methods study conducted in Mumbai and Kathmandu. Our results show that there are some relationships between accountability and learning outcomes, but these appear to be specific to the context. Quantitative data also show that differences between public and private models of schooling are negligible when students’ social backgrounds and school composition are considered. Qualitative data show that accountability processes create a significant burden on staff time and embed complex power dynamics that are not always productive. Taken together, these results problematize policies that seek to improve learning through “demand-side” approaches such as privatization. They show that the dynamics of accountability are a complex system, like the motion of a “double pendulum,” and therefore simple conceptual approaches such as the principal-agent model are of limited academic and practical utility
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