Abstract
We compute the spherically averaged power spectrum from four seasons of data obtained for the Epoch of Reionization (EoR) project observed with the Murchison Widefield Array (MWA). We ...measure the EoR power spectrum over k = 0.07–3.0 h Mpc−1 at redshifts $z$ = 6.5–8.7. The largest aggregation of 110 h on EoR0 high band (3340 observations), yields a lowest measurement of (43 mK)2 = 1.8 × 103 mK2 at k = 0.14 h Mpc−1 and $z$ = 6.5 (2σ thermal noise plus sample variance). Using the Real-Time System to calibrate and the CHIPS pipeline to estimate power spectra, we select the best observations from the central five pointings within the 2013–2016 observing seasons, observing three independent fields and in two frequency bands. This yields 13 591 2-min snapshots (453 h), based on a quality assurance metric that measures ionospheric activity. We perform another cut to remove poorly calibrated data, based on power in the foreground-dominated and EoR-dominated regions of the two-dimensional power spectrum, reducing the set to 12 569 observations (419 h). These data are processed in groups of 20 observations, to retain the capacity to identify poor data, and used to analyse the evolution and structure of the data over field, frequency, and data quality. We subsequently choose the cleanest 8935 observations (298 h of data) to form integrated power spectra over the different fields, pointings, and redshift ranges.
New York City (NYC) bore the greatest burden of COVID-19 in the United States early in the pandemic. In this case series, we describe characteristics and outcomes of racially and ethnically diverse ...patients tested for and hospitalized with COVID-19 in New York City's public hospital system.
We reviewed the electronic health records of all patients who received a SARS-CoV-2 test between March 5 and April 9, 2020, with follow up through April 16, 2020. The primary outcomes were a positive test, hospitalization, and death. Demographics and comorbidities were also assessed.
22254 patients were tested for SARS-CoV-2. 13442 (61%) were positive; among those, the median age was 52.7 years (interquartile range IQR 39.5-64.5), 7481 (56%) were male, 3518 (26%) were Black, and 4593 (34%) were Hispanic. Nearly half (4669, 46%) had at least one chronic disease (27% diabetes, 30% hypertension, and 21% cardiovascular disease). Of those testing positive, 6248 (46%) were hospitalized. The median age was 61.6 years (IQR 49.7-72.9); 3851 (62%) were male, 1950 (31%) were Black, and 2102 (34%) were Hispanic. More than half (3269, 53%) had at least one chronic disease (33% diabetes, 37% hypertension, 24% cardiovascular disease, 11% chronic kidney disease). 1724 (28%) hospitalized patients died. The median age was 71.0 years (IQR 60.0, 80.9); 1087 (63%) were male, 506 (29%) were Black, and 528 (31%) were Hispanic. Chronic diseases were common (35% diabetes, 37% hypertension, 28% cardiovascular disease, 15% chronic kidney disease). Male sex, older age, diabetes, cardiac history, and chronic kidney disease were significantly associated with testing positive, hospitalization, and death. Racial/ethnic disparities were observed across all outcomes.
This is the largest and most racially/ethnically diverse case series of patients tested and hospitalized for COVID-19 in New York City to date. Our findings highlight disparities in outcomes that can inform prevention and testing recommendations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionized radio astronomy. Despite their construction ...from static, relatively simple dipoles, the sheer number of distinct elements introduces new, complicated instrumental effects. Their necessary remote locations exacerbate failure rates, while electronic interactions between the many adjacent receiving elements can lead to non-trivial instrumental effects. The Murchison Widefield Array (MWA) employs phased array antenna elements (tiles), which improve collecting area at the expense of complex beam shapes. Advanced electromagnetic simulations have produced the fully embedded element (FEE) simulated beam model which has been highly successful in describing the ideal beam response of MWA antennas. This work focuses on the relatively unexplored aspect of various in-situ, environmental perturbations to beam models and represents the first large-scale, in-situ, all-sky measurement of MWA beam shapes at multiple polarizations and pointings. Our satellite based beam measurement approach enables all-sky beam response measurements with a dynamic range of ∼50 dB, at 137 MHz.
ABSTRACT
Observations in the lowest Murchison Widefield Array (MWA) band between 75 and 100 MHz have the potential to constrain the distribution of neutral hydrogen in the intergalactic medium at ...redshift ∼13–17. Using 15 h of MWA data, we analyse systematics in this band such as radio-frequency interference (RFI), ionospheric and wide field effects. By updating the position of point sources, we mitigate the direction-independent calibration error due to ionospheric offsets. Our calibration strategy is optimized for the lowest frequency bands by reducing the number of direction-dependent calibrators and taking into account radio sources within a wider field of view. We remove data polluted by systematics based on the RFI occupancy and ionospheric conditions, finally selecting 5.5 h of the cleanest data. Using these data, we obtain 2σ upper limits on the 21 cm power spectrum in the range of $0.1~ h~{\mathrm{ Mpc}}^{-1}\lessapprox k \lessapprox 1 ~ ~h~{\mathrm{ Mpc}}^{-1}$ and at z = 14.2, 15.2, and 16.5, with the lowest limit being $6.3\times 10^6 ~\rm mK^2$ at $k=0.14 ~h~{\mathrm{ Mpc}}^{-1}$ and at z = 15.2 with a possibility of a few per cent of signal loss due to direction-independent calibration.
Income, Poverty, and Health Inequality Chokshi, Dave A
JAMA : the journal of the American Medical Association,
04/2018, Letnik:
319, Številka:
13
Journal Article
Recenzirano
The article discusses the relationship between low-income, poverty and health inequality and its prevalence even in the current environment. To improve health, the need is to take into account ...starkly different lived experiences across different geographic contexts. Clinicians who care about social determinants of health also need to pay attention to the costs of care as well.
ABSTRACT
Current attempts to measure the 21 cm power spectrum of neutral hydrogen during the epoch of reionization (EoR) are limited by systematics that produce measured upper limits above both the ...thermal noise and the expected cosmological signal. These systematics arise from a combination of observational, instrumental, and analysis effects. In order to further understand and mitigate these effects, it is instructive to explore different aspects of existing data sets. One such aspect is the choice of observing field. To date, MWA EoR observations have largely focused on the EoR0 field. In this work, we present a new detailed analysis of the EoR1 field. The EoR1 field is one of the coldest regions of the southern radio sky, but contains the very bright radio galaxy Fornax-A. The presence of this bright extended source in the primary beam of the interferometer makes the calibration and analysis of EoR1 particularly challenging. We demonstrate the effectiveness of a recently developed shapelet model of Fornax-A in improving the results from this field. We also describe and apply a series of data quality metrics that identify and remove systematically contaminated data. With substantially improved source models, upgraded analysis algorithms and enhanced data quality metrics, we determine EoR power spectrum upper limits based on analysis of the best ∼14-h data observed during 2015 and 2014 at redshifts 6.5, 6.8, and 7.1, with the lowest 2σ upper limit at z = 6.5 of Δ2 ≤ (73.78 mK)2 at k = 0.13 h Mpc−1, improving on previous EoR1 measurement results.
Noncommunicable diseases (NCDs)-largely comprising cardiovascular disease, cancer, chronic pulmonary disease, and diabetes-are the most important global health issues of the 21st century, as measured ...by both mortality and morbidity (1, 2). These diseases are as preventable across entire populations as are infectious diseases, but require a different approach-one that involves policy change to promote healthy behaviors.
Tensile experiments on a fine-grained single-phase Mg–Zn–Al alloy (AZ31) at 673
K revealed superplastic behavior with an elongation to failure of 475% at 1
×
10
−4
s
−1 and non-superplastic behavior ...with an elongation to failure of 160% at 1
×
10
−2
s
−1; the corresponding strain rate sensitivities under these conditions were ∼0.5 and ∼0.2, respectively. Measurements indicated that the grain boundary sliding (GBS) contribution to strain
ξ was ∼30% under non-superplastic conditions; there was also a significant sharpening in texture during such deformation. Under superplastic conditions,
ξ was ∼50% at both low and high elongations of ∼20% and 120%; the initial texture became more random under such conditions. In non-superplastic conditions, deformation occurred under steady-state conditions without grain growth before significant flow localization whereas, under superplastic conditions, there was grain growth during the early stages of deformation, leading to strain hardening. The grains retained equiaxed shapes under all experimental conditions. Superplastic deformation is attributed to GBS, while non-superplastic deformation is attributed to intragranular dislocation creep with some contribution from GBS. The retention of equiaxed grain shapes during dislocation creep is consistent with a model based on local recovery related to the disturbance of triple junctions.
In November of 2021, multiple factors converged to create a window of opportunity to open overdose prevention centers (OPCs) at two existing syringe service programs (SSPs) in New York City (NYC). ...Political will exists in NYC, particularly toward the end of the de Blasio administration’s term, and the NYC Health Department worked to garner additional support from local and state elected officials given the dire need to address the overdose crisis. This coincided with readiness on the part of one of the NYC SSP providers, OnPoint NYC, to open and operate OPC services. Legal risks were assessed by both the city and the provider. This case study outlines the sequence of events that resulted in NYC supporting OnPoint to open the first two publicly recognized OPCs in the nation, including lessons learned to inform other jurisdictions considering offering such services.
The authors describe the rapid expansion of retail clinics and urgent care centers in the United States, and they discuss their potential cost advantages and their potential threats to quality of ...care. They also review the current regulation of these new models of care.
Every year, 1.2 billion visits are made in ambulatory care settings, accounting for approximately one third of health care spending in the United States.
1
,
2
Although the vast majority of these visits take place in office-based clinics and emergency departments, an increasing number of patients are seeking care in nontraditional sites such as retail clinics and urgent care centers. Retail clinics are walk-in health clinics, typically located in pharmacies or supermarkets, that provide immediate care for a narrowly defined scope of services, such as the diagnosis and treatment of minor acute illnesses, as well as some preventive care and care . . .
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