434 research outputs found

    QCD Rescattering and High Energy Two-Body Photodisintegration of the Deuteron

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    Photon absorption by a quark in one nucleon followed by its high momentum transfer interaction with a quark in the other may produce two final-state nucleons with high relative momentum. We sum the relevant quark rescattering diagrams, to show that the scattering amplitude depends on a convolution between the large angle pnpn scattering amplitude, the hard photon-quark interaction vertex and the low-momentum deuteron wave function. The computed absolute values of the cross section are in reasonable agreement with the data.Comment: 4 pages, revised version to be published in Phys. Rev. Let

    Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

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    Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD

    The association of functional status with mortality and dialysis modality change : results from the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS)

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    BACKGROUND: Little is known about the prevalence of functional impairment in peritoneal dialysis (PD) patients, its variation by country, and its association with mortality or transfer to hemodialysis. METHODS: A prospective cohort study was conducted in PD patients from 7 countries in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) (2014 - 2017). Functional status (FS) was assessed by combining self-reports of 8 instrumental and 5 basic activities of daily living, using the Lawton-Brody and the Katz questionnaires. Summary FS scores, ranging from 1.25 (most dependent) to 13 (independent), were based on the patient's ability to perform each activity with or without assistance. Logistic regression was used to estimate the odds ratio (OR; 95% confidence interval [CI]) of a FS score < 11 comparing each country with the United States (US). Cox regression was used to estimate the hazard ratio (HR; 95% CI) for the effect of a low FS score on mortality and transfer to hemodialysis, adjusting for case mix. RESULTS: Of 2,593 patients with complete data on FS, 48% were fully independent (FS = 13), 32% had a FS score 11 to < 13, 14% had a FS score 8 to < 11, and 6% had a FS score < 8. Relative to the US, low FS scores (< 11; more dependent) were more frequent in Thailand (OR = 10.48, 5.90 - 18.60) and the United Kingdom (UK) (OR = 3.29, 1.77 - 6.08), but similar in other PDOPPS countries. The FS score was inversely and monotonically associated with mortality but not with transfer to hemodialysis; the HR, comparing a FS score < 8 vs 13, was 4.01 (2.44 - 6.61) for mortality and 0.91 (0.58 - 1.43) for transfer to hemodialysis. CONCLUSION: Regional differences in FS scores observed across PDOPPS countries may have been partly due to differences in regional patient selection for PD. Functional impairment was associated with mortality but not with permanent transfer to hemodialysis

    Surface processes recorded by rocks and soils on Meridiani Planum, Mars: Microscopic Imager observations during Opportunity's first three extended missions

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    The Microscopic Imager (MI) on the Mars Exploration Rover Opportunity has returned images of Mars with higher resolution than any previous camera system, allowing detailed petrographic and sedimentological studies of the rocks and soils at the Meridiani Planum landing site. Designed to simulate a geologist's hand lens, the MI is mounted on Opportunity's instrument arm and can resolve objects 0.1 mm across or larger. This paper provides an overview of MI operations, data calibration, and analysis of MI data returned during the first 900 sols (Mars days) of the Opportunity landed mission. Analyses of Opportunity MI data have helped to resolve major questions about the origin of observed textures and features. These studies support eolian sediment transport, rather than impact surge processes, as the dominant depositional mechanism for Burns formation strata. MI stereo observations of a rock outcrop near the rim of Erebus Crater support the previous interpretation of similar sedimentary structures in Eagle Crater as being formed by surficial flow of liquid water. Well-sorted spherules dominate ripple surfaces on the Meridiani plains, and the size of spherules between ripples decreases by about 1 mm from north to south along Opportunity's traverse between Endurance and Erebus craters

    May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension

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    Aims Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries. Methods and results Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension. Conclusion May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk

    The concurrent decline of soil lead and children’s blood lead in New Orleans

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    Lead (Pb) is extremely toxic and a major cause of chronic diseases worldwide. Pb is associated with health disparities, particularly within low-income populations. In biological systems, Pb mimics calcium and, among other effects, interrupts cell signaling. Furthermore, Pb exposure results in epigenetic changes that affect multigenerational gene expression. Exposure to Pb has decreased through primary prevention, including removal of Pb solder from canned food, regulating lead-based paint, and especially eliminating Pb additives in gasoline. While researchers observe a continuous decline in children’s blood lead (BPb), reservoirs of exposure persist in topsoil, which stores the legacy dust from leaded gasoline and other sources. Our surveys of metropolitan New Orleans reveal that median topsoil Pb in communities (n = 274) decreased 44% from 99 mg/kg to 54 mg/kg (P value of 2.09 × 10−08), with a median depletion rate of ∼2.4 mg·kg·y−1 over 15 y. From 2000 through 2005 to 2011 through 2016, children’s BPb declined from 3.6 μg/dL to 1.2 μg/dL or 64% (P value of 2.02 × 10−85), a decrease of ∼0.2 μg·dL·y−1 during a median of 12 y. Here, we explore the decline of children’s BPb by examining a metabolism of cities framework of inputs, transformations, storages, and outputs. Our findings indicate that decreasing Pb in topsoil is an important factor in the continuous decline of children’s BPb. Similar reductions are expected in other major US cities. The most contaminated urban communities, usually inhabited by vulnerable populations, require further reductions of topsoil Pb to fulfill primary prevention for the nation’s children

    Global nephrology workforce: gaps and opportunities toward a sustainable kidney care&nbsp;system

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    The health workforce is the cornerstone of any health care system. An adequately trained and sufficiently staffed workforce is essential to reach universal health coverage. In particular, a nephrology workforce is critical to meet the growing worldwide burden of kidney disease. Despite some attempts, the global nephrology workforce and training capacity remains widely unknown. This multinational cross-sectional survey was part of the Global Kidney Health Atlas project, a new initiative administered by the International Society of Nephrology (ISN). The objective of this study was to address the existing global nephrology workforce and training capacity. The questionnaire was administered online, and all data were analyzed and presented by ISN regions and World Bank country classification. Overall, 125 United Nations member states responded to the entire survey, with 121 countries responding to survey questions pertaining to the nephrology workforce. The global nephrologist density was 8.83 per million population (PMP); high-income countries reported a nephrologist density of 28.52 PMP compared with 0.31 PMP in low-income countries. Similarly, the global nephrologist trainee density was 1.87 PMP; high-income countries reported a 30 times greater nephrology trainee density than low-income countries (6.03 PMP vs. 0.18 PMP). Countries reported a shortage in all care providers in nephrology. A nephrology training program existed in 79% of countries, ranging from 97% in high-income countries to 41% in low-income countries. In countries with a training program, the majority (86%) of programs were 2 to 4 years, and the most common training structure (56%) was following general internal medicine. We found significant variation in the global density of nephrologists and nephrology trainees and shortages in all care providers in nephrology; the gap was more prominent in low-income countries, particularly in African and South Asian ISN regions. These findings point to significant gaps in the current nephrology workforce and opportunities for countries and regions to develop and maintain a sustainable workforce
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