Abstract
Using high-resolution (sub-kiloparsec scale) data obtained by ALMA, we analyse the star formation rate (SFR), gas content, and kinematics in SDP 81, a gravitationally lensed starburst galaxy ...at redshift 3. We estimate the SFR surface density (ΣSFR) in the brightest clump of this galaxy to be $357^{+135}_{-85}\, \mathrm{M}_{\odot }\, \mathrm{yr}^{-1}\, \mathrm{kpc}^{-2}$, over an area of 0.07 ± 0.02 kpc2. Using the intensity-weighted velocity of CO (5–4), we measure the turbulent velocity dispersion in the plane of the sky and find σv, turb = 37 ± 5 km s−1 for the clump, in good agreement with previous estimates along the line of sight. Our measurements of the gas surface density, freefall time, and turbulent Mach number allow us to compare the theoretical SFR from various star formation models with that observed, revealing that the role of turbulence is crucial to explaining the observed SFR in this clump. While the Kennicutt–Schmidt (KS) relation predicts an SFR surface density of ΣSFR, KS = 52 ± 17 M⊙ yr−1 kpc−2, the single-freefall model by Krumholz, Dekel, and McKee (KDM) predicts ΣSFR, KDM = 106 ± 37 M⊙ yr−1 kpc−2. In contrast, the multifreefall (turbulence) model by Salim, Federrath, and Kewley (SFK) gives $\Sigma _{\mathrm{SFR,SFK}} = 491^{+139 }_{-194}\, \mathrm{M}_{\odot }\, \mathrm{yr}^{-1}\, \mathrm{kpc}^{-2}$. Although the SFK relation overestimates the SFR in this clump (possibly due to the negligence of magnetic fields), it provides the best prediction among the available models. Finally, we compare the star formation and gas properties of this galaxy to local star-forming regions and find that the SFK relation provides the best estimates of SFR in both local and high-redshift galaxies.
Abstract
We present the first compelling evidence of shock-heated molecular clouds associated with the supernova remnant (SNR) N49 in the Large Magellanic Cloud (LMC). Using
12
CO(
J
= 2–1, 3–2) and
...13
CO(
J
= 2–1) line emission data taken with the Atacama Large Millimeter/Submillimeter Array, we derived the H
2
number density and kinetic temperature of eight
13
CO-detected clouds using the large velocity gradient approximation at a resolution of 3.″5 (∼0.8 pc at the LMC distance). The physical properties of the clouds are divided into two categories: three of them near the shock front show the highest temperatures of ∼50 K with densities of ∼500–700 cm
−3
, while other clouds slightly distant from the SNR have moderate temperatures of ∼20 K with densities of ∼800–1300 cm
−3
. The former clouds were heated by supernova shocks, but the latter were dominantly affected by the cosmic-ray heating. These findings are consistent with the efficient production of X-ray recombining plasma in N49 due to thermal conduction between the cold clouds and hot plasma. We also find that the gas pressure is roughly constant except for the three shock-engulfed clouds inside or on the SNR shell, suggesting that almost no clouds have evaporated within the short SNR age of ∼4800 yr. This result is compatible with the shock-interaction model with dense and clumpy clouds inside a low-density wind bubble.
SETTING: Bangalore city slums, India.OBJECTIVES: To ascertain 1) health-seeking behaviour patterns in persons with pulmonary symptoms; 2) pathways followed by pulmonary tuberculosis (PTB) cases until ...diagnosis and treatment; and 3) their knowledge about TB-symptoms, cause,
mode of transmission, diagnosis and treatment.METHODS: In selected slums, persons with pulmonary symptoms identified during house visits and residents with PTB were interviewed using pre-tested, semi-structured questionnaires. Visits to relevant health centres were made to obtain information
regarding their treatment.RESULTS: About 50% of the 124 persons with pulmonary symptoms interviewed had taken action for relief; of these, three quarters had first approached private health facilities. About 19% had undergone sputum microscopy and 27% chest X-ray. Of 47 PTB cases interviewed,
72% first approached private health facilities; about 50% visited two health facilities before diagnosis and 87% visited two or more facilities before initiating treatment; 42 initiated treatment at government health facilities and five who initiated treatment at private health facilities
were later referred to government health facilities. The majority of persons with pulmonary symptoms and PTB cases had poor knowledge about TB, and most of those with pulmonary symptoms were not aware of the availability of free anti-tuberculosis services at government health facilities.CONCLUSION:
Educational interventions targeted at slum dwellers and their health providers are needed.
Objective: The objective of this study was to determine the prevalence and estimate total costs for chronic health conditions in the U.S. workforce for the Dow Chemica Company (Dow). Methods: Using ...the Stanford Presenteeism Scale, information was collected from workers at five locations on work impairment and absenteeism based on self-reported "primary" chronic health conditions. Survey data were merged with employee demographics, medical and pharmaceutical claims, smoking status, biometric health risk factors, payroll records, and job type. Results: Almost 65% of respondents reported having one or more of the surveyed chronic conditions. The most common were allergies, arthritis/joint pain or stiffness, and back or neck disorders. The associated absenteeism by chronic condition ranged from 0.9 to 5.9 hours in a 4-week period, and on-the-job work impairment ranged from a 17.8% to 36.4% decrement in ability to function at work. The presence of a chronic condition was the most important determinant of the reported levels of work impairment and absence after adjusting for other factors (P < 0.000). The total cost of chronic conditions was estimated to be 10.7% of the total labor costs for Dow in the United States; 6.8% was attributable to work impairment alone. Conclusion: For all chronic conditions studied, the cost associated with performance based work loss or "presenteeism" greatly exceeded the combined costs of absenteeism and medical treatment combined.
The avascular nature of cartilage makes it a unique tissue
, but whether and how the absence of nutrient supply regulates chondrogenesis remain unknown. Here we show that obstruction of vascular ...invasion during bone healing favours chondrogenic over osteogenic differentiation of skeletal progenitor cells. Unexpectedly, this process is driven by a decreased availability of extracellular lipids. When lipids are scarce, skeletal progenitors activate forkhead box O (FOXO) transcription factors, which bind to the Sox9 promoter and increase its expression. Besides initiating chondrogenesis, SOX9 acts as a regulator of cellular metabolism by suppressing oxidation of fatty acids, and thus adapts the cells to an avascular life. Our results define lipid scarcity as an important determinant of chondrogenic commitment, reveal a role for FOXO transcription factors during lipid starvation, and identify SOX9 as a critical metabolic mediator. These data highlight the importance of the nutritional microenvironment in the specification of skeletal cell fate.
Health disparities across ethnic or racial groups are typically examined through single behavior at a time. The syndemics and multimorbidity health disparities have not been well examined by race. In ...this study, we study health disparities by identifying the networks of multimorbidities among individuals from seven population groups based on race, including White, African American, Asian, Hispanic, Native American, Bi- or Multi-racial and Pacific Islander. We examined a large electronic medical record (EMR) containing health records of more than 18.7 million patients and created multimorbidity networks considering their lifetime history from medical records in order to compare the network properties among seven population groups. In addition, the networks at organ system level depicting the relationship among disorders belonging to different organ systems are also compared. Our macro analysis at the organ-level indicates that African-Americans have a stronger multimorbidity network followed by Whites and Native Americans. The networks of Asians and Hispanics are sparse. Specifically, the relationship of infectious and parasitic disorders with respiratory, circulatory and genitourinary system disorders is stronger among African Americans than others. On the other hand, the relationship of mental disorders with respiratory, musculoskeletal system and connective tissue disorders is more prevalent in Whites. Similar other disparities are discussed. Recognition and explanation of such differences in multimorbidities inform the public health policies, and can inform clinical decisions as well. Our multimorbidity network analysis identifies specific differences in diagnoses among different population groups, and presents questions for biological, behavioral, clinical, social science, and policy research.
Ventricular fibrillation (VF) is the leading cause of sudden cardiac death. Yet, the mechanisms of VF remain elusive. Pixel-by-pixel spectral analysis of optical signals was carried out in video ...imaging experiments using a potentiometric dye in the Langendorff-perfused guinea pig heart. Dominant frequencies (peak with maximal power) were distributed throughout the ventricles in clearly demarcated domains. The fastest domain (25 to 32 Hz) was always on the anterior left ventricular (LV) wall and was shown to result from persistent rotor activity. Intermittent block and breakage of wavefronts at specific locations in the periphery of such rotors were responsible for the domain organization. Patch-clamping of ventricular myocytes from the LV and the right ventricle (RV) demonstrated an LV-to-RV drop in the amplitude of the outward component of the background rectifier current (IB). Computer simulations suggested that rotor stability in LV resulted from relatively small rectification of IB (presumably IK1), whereas instability, termination, and wavebreaks in RV were a consequence of strong rectification. This study provides new evidence in the isolated guinea pig heart that a persistent high-frequency rotor in the LV maintains VF, and that spatially distributed gradients in IK1 density represent a robust ionic mechanism for rotor stabilization and wavefront fragmentation.
Heat sink or heat exchanger is a passive cooling device used in electronic components to prolong their longevity, performance and reliability. All electronic components utilize current for the ...operational purposes and thus become prone to sharp increase in the temperature. The generated heat above the operating level becomes critical in-terms of failure component and hence, appropriate thermal management demands come into act. Finned or extended surface heat sinks are used to cool power electronic devices and components. The comparative results of plate-fin forms on the thermal performance of the heat-sink with inline arrangement is analyzed in this paper. Four forms of fins: Rectangular, One-side tapered, Inverted T section and I section with and without honeycomb perforations are designed on SOLIDWORKS® and analysed using ANSYS® software to identify a cooling solution for a CPU in terms of temperature and directional heat flux along x, y and z directions. The aluminium alloy 6063-T6 and natural graphite are selected as a base plate and fin materials respectively. The main objective of this paper is to contribute to this improving area of research by studying the effect of honeycomb perforations of plate fin heat sinks under natural convection using steady state thermal analysis at a constant heat flow of 20W and 40W in two different cases with air inlet temperature taken as 37.85° C. A total of 16 specimen were analysed. 8 specimen of plate fin heat sinks without perforations were compared with the rest 8 specimen with honeycomb perforations. It was evaluated from both the cases that inverted T sectional fin with perforations provided an improvement in thermal efficiency and better heat flux removal results among other plate fin profiles where as in terms of density and cost trade-offs one side perforated tapered fin outperformed other fins.
•A stepwise explainable deep learning formulation using linear regression (LR) and a recurrent neural network.•Facilitate quota-based planning to balance utilization rates between for-hire vehicles ...(FHVs) and traditional taxis.•Data analysis from New York City Taxi & Limousine Commission to observe the correlation between FHV and regular taxis.•Real-world data sets examined for coupled LR and long short-term memory (LSTM) framework.
As app-based ride-hailing services have been widely adopted within existing traditional taxi markets, researchers have been devoted to understand the important factors that influence the demand of the new mobility. Econometric models (EMs) are mainly utilized to interpret the significant factors of the demand, and deep neural networks (DNNs) have been recently used to improve the forecasting performance by capturing complex patterns in the large datasets. However, to mitigate possible (induced) traffic congestion and balance utilization rates for the current taxi drivers, an effective strategy of proactively managing a quota system for both emerging services and regular taxis is still critically needed. This paper aims to systematically design an explainable deep learning model capable of assessing the quota system balancing the demand volumes between two modes. A two-stage interpretable machine learning modeling framework was developed by a linear regression (LR) model, coupled with a neural network layered by long short-term memory (LSTM). The first stage investigates the correlation between the existing taxis and on-demand ride-hailing services while controlling for other explanatory variables. The second stage fulfills the long short-term memory (LSTM) network structure, capturing the residuals from the first estimation stage in order to enhance the forecasting performance. The proposed stepwise modeling approach (LR-LSTM) forecasts the demand of taxi rides, and it is implemented in the application of pick-up demand prediction using New York City (NYC) taxi data. The experiment result indicates that the integrated model can capture the inter-relationships between existing taxis and ride-hailing services as well as identify the influence of additional factors, namely, the day of the week, weather, and holidays. Overall, this modeling approach can be applied to construct an effective active demand management (ADM) for the short-term period as well as a quota control strategy between on-demand ride-hailing services and traditional taxis.
PDF
