This study explores the effectiveness of shape-memory-alloy (SMA)-based self-centring energy-dissipation bays (SCEDBs) for enhancing the seismic performance of high-strength-steel (HSS) frames. The ...work commences with the development of an ensemble of prototype HSS frames equipped with SCEDBs, known as HSSF-SCEDB structures. The prototype systems are examined using cyclic-pushover and nonlinear-response-history analyses (NL-RHAs). According to the analysis database, it is found that the cyclic-pushover responses generally show a typical flag shape over a wide deformation range and that the post-earthquake residual deformations are below 0.5%, even following maximum interstorey drifts beyond the codified deformation threshold (i.e. 2%). To offer a practical tool to engineers for damage-control behaviour evaluation and seismic demand estimation, we develop a multimodal nonlinear static procedure based on a modified energy-balance concept. Conventional procedures relating to the fundamental vibration mode are also revisited. The results indicate that a medium-rise HSSF-SCEDB may be appreciably influenced by higher vibration modes. The difference between the average maximum interstorey drifts calculated by NL-RHAs and those obtained using the proposed procedure for an ensemble of earthquake motions is generally below 5%, and the adequacy of the proposed method is confirmed.
Sepsis is a major contributor to the global burden of disease. The majority of sepsis cases and deaths are estimated to occur in low and middle-income countries. Barriers to reducing the global ...burden of sepsis include difficulty quantifying attributable morbidity and mortality, low awareness, poverty and health inequity, and under-resourced and low-resilience public health and acute health care delivery systems. Important differences in the populations at risk, infecting pathogens, and clinical capacity to manage sepsis in high and low-resource settings necessitate context-specific approaches to this significant problem. We review these challenges and propose strategies to overcome them. These strategies include strengthening health systems, accurately identifying and quantifying sepsis cases, conducting inclusive research, establishing data-driven and context-specific management guidelines, promoting creative clinical interventions, and advocacy.
IMPORTANCE: Estimates from claims-based analyses suggest that the incidence of sepsis is increasing and mortality rates from sepsis are decreasing. However, estimates from claims data may lack ...clinical fidelity and can be affected by changing diagnosis and coding practices over time. OBJECTIVE: To estimate the US national incidence of sepsis and trends using detailed clinical data from the electronic health record (EHR) systems of diverse hospitals. DESIGN, SETTING, AND POPULATION: Retrospective cohort study of adult patients admitted to 409 academic, community, and federal hospitals from 2009-2014. EXPOSURES: Sepsis was identified using clinical indicators of presumed infection and concurrent acute organ dysfunction, adapting Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) criteria for objective and consistent EHR-based surveillance. MAIN OUTCOMES AND MEASURES: Sepsis incidence, outcomes, and trends from 2009-2014 were calculated using regression models and compared with claims-based estimates using International Classification of Diseases, Ninth Revision, Clinical Modification codes for severe sepsis or septic shock. Case-finding criteria were validated against Sepsis-3 criteria using medical record reviews. RESULTS: A total of 173 690 sepsis cases (mean age, 66.5 SD, 15.5 y; 77 660 42.4% women) were identified using clinical criteria among 2 901 019 adults admitted to study hospitals in 2014 (6.0% incidence). Of these, 26 061 (15.0%) died in the hospital and 10 731 (6.2%) were discharged to hospice. From 2009-2014, sepsis incidence using clinical criteria was stable (+0.6% relative change/y 95% CI, −2.3% to 3.5%, P = .67) whereas incidence per claims increased (+10.3%/y 95% CI, 7.2% to 13.3%, P < .001). In-hospital mortality using clinical criteria declined (−3.3%/y 95% CI, −5.6% to −1.0%, P = .004), but there was no significant change in the combined outcome of death or discharge to hospice (−1.3%/y 95% CI, −3.2% to 0.6%, P = .19). In contrast, mortality using claims declined significantly (−7.0%/y 95% CI, −8.8% to −5.2%, P < .001), as did death or discharge to hospice (−4.5%/y 95% CI, −6.1% to −2.8%, P < .001). Clinical criteria were more sensitive in identifying sepsis than claims (69.7% 95% CI, 52.9% to 92.0% vs 32.3% 95% CI, 24.4% to 43.0%, P < .001), with comparable positive predictive value (70.4% 95% CI, 64.0% to 76.8% vs 75.2% 95% CI, 69.8% to 80.6%, P = .23). CONCLUSIONS AND RELEVANCE: In clinical data from 409 hospitals, sepsis was present in 6% of adult hospitalizations, and in contrast to claims-based analyses, neither the incidence of sepsis nor the combined outcome of death or discharge to hospice changed significantly between 2009-2014. The findings also suggest that EHR-based clinical data provide more objective estimates than claims-based data for sepsis surveillance.
We present Hubble Space Telescope (HST) Wide Field Camera 3 UV and near-IR (nIR) imaging of 21 Superluminous Supernovae (SLSNe) host galaxies, providing a sensitive probe of star formation and ...stellar mass within the hosts. Comparing the photometric and morphological properties of these host galaxies with those of core-collapse supernovae (CCSNe) and long-duration gamma-ray bursts (LGRBs), we find SLSN hosts are fainter and more compact at both UV and nIR wavelengths, in some cases we barely recover hosts with absolute magnitude around MV ≈ −14. With the addition of ground based optical observations and archival results, we produce spectral energy distribution fits to these hosts, and show that SLSN hosts possess lower stellar mass and star formation rates. This is most pronounced for the hydrogen deficient Type-I SLSN hosts, although Type-II H-rich SLSN host galaxies remain distinct from the bulk of CCSNe, spanning a remarkably broad range of absolute magnitudes, with ∼30 per cent of SLSNe-II arising from galaxies fainter than M
nIR ∼ −14. The detection of our faintest SLSN hosts increases the confidence that SLSNe-I hosts are distinct from those of LGRBs in star formation rate and stellar mass, and suggests that apparent similarities in metallicity may be due to the limited fraction of hosts for which emission line metallicity measurements are feasible. The broad range of luminosities of SLSN-II hosts is difficult to describe by metallicity cuts, and does not match the expectations of any reasonable UV-weighted luminosity function, suggesting additional environmental constraints are likely necessary to yield hydrogen rich SLSNe.
ABSTRACT
We present measurements of the local core-collapse supernova (CCSN) rate using SN discoveries from the Palomar Transient Factory (PTF). We use a Monte Carlo simulation of hundreds of ...millions of SN light-curve realizations coupled with the detailed PTF survey detection efficiencies to forward model the SN rates in PTF. Using a sample of 86 CCSNe, including 26 stripped-envelope SNe (SESNe), we show that the overall CCSN volumetric rate is $r^\mathrm{CC}_v=9.10_{-1.27}^{+1.56}\times 10^{-5}\, \text{SNe yr}^{-1}\, \text{Mpc}^{-3}\, h_{70}^{3}$ at 〈z〉 = 0.028, and the SESN volumetric rate is $r^\mathrm{SE}_v=2.41_{-0.64}^{+0.81}\times 10^{-5}\, \text{SNe yr}^{-1}\, \text{Mpc}^{-3}\, h_{70}^{3}$. We further measure a volumetric rate for hydrogen-free superluminous SNe (SLSNe-I) using eight events at z ≤ 0.2 of $r^\mathrm{SLSN-I}_v=35_{-13}^{+25}\, \text{SNe yr}^{-1}\text{Gpc}^{-3}\, h_{70}^{3}$, which represents the most precise SLSN-I rate measurement to date. Using a simple cosmic star formation history to adjust these volumetric rate measurements to the same redshift, we measure a local ratio of SLSN-I to SESN of ${\sim}1/810^{+1500}_{-94}$, and of SLSN-I to all CCSN types of ${\sim}1/3500^{+2800}_{-720}$. However, using host galaxy stellar mass as a proxy for metallicity, we also show that this ratio is strongly metallicity dependent: in low-mass (logM* < 9.5 M⊙) galaxies, which are the only environments that host SLSN-I in our sample, we measure an SLSN-I to SESN fraction of $1/300^{+380}_{-170}$ and $1/1700^{+1800}_{-720}$ for all CCSN. We further investigate the SN rates a function of host galaxy stellar mass, and show that the specific rates of all CCSNe decrease with increasing stellar mass.
This survey provides a selective review of the literature on patent policy, innovation and economic growth. The patent system is a useful policy tool for stimulating innovation given its importance ...on technological progress and economic growth. However, the patent system is a multidimensional system, which features multiple patent policy instruments. In this survey, we review some of the commonly discussed patent policy instruments, such as patent length, patent breadth and blocking patents, and also use a canonical Schumpeterian growth model to demonstrate their different effects on innovation and the macroeconomy.
The tensions between evaluating treatments (learning) and just treating patients (doing) during the COVID-19 pandemic are described. The clinical research and practice communities are encouraged to ...support each other's imperatives, so that both can "learn from doing" in a more integrated patient care approach. Actions toward the realization of this goal are also proposed.
The epidemiology of chronic critical illness is not well characterized. We sought to determine the prevalence, outcomes, and associated costs of chronic critical illness in the United States.
...Population-based cohort study using data from the United States Healthcare Costs and Utilization Project from 2004 to 2009.
Acute care hospitals in Massachusetts, North Carolina, Nebraska, New York, and Washington.
Adult and pediatric patients meeting a consensus-derived definition for chronic critical illness, which included one of six eligible clinical conditions (prolonged acute mechanical ventilation, tracheotomy, stroke, traumatic brain injury, sepsis, or severe wounds) plus at least 8 days in an ICU.
None.
Out of 3,235,741 admissions to an ICU during the study period, 246,151 (7.6%) met the consensus definition for chronic critical illness. The most common eligibility conditions were prolonged acute mechanical ventilation (72.0% of eligible admissions) and sepsis (63.7% of eligible admissions). Among patients meeting chronic critical illness criteria through sepsis, the infections were community acquired in 48.5% and hospital acquired in 51.5%. In-hospital mortality was 30.9% with little change over the study period. The overall population-based prevalence was 34.4 per 100,000. The prevalence varied substantially with age, peaking at 82.1 per 100,000 individuals 75-79 years old but then declining coincident with a rise in mortality before day 8 in otherwise eligible patients. Extrapolating to the entire United States, for 2009, we estimated a total of 380,001 cases; 107,880 in-hospital deaths and $26 billion in hospital-related costs.
Using a consensus-based definition, the prevalence, hospital mortality, and costs of chronic critical illness are substantial. Chronic critical illness is particularly common in the elderly although in very old patients the prevalence declines, in part because of an increase in early mortality among potentially eligible patients.
R&D investment has well-known liquidity problems, with potentially important consequences. In this study, we analyze the effects of monetary policy on economic growth and social welfare in a ...Schumpeterian growth model with cash-in-advance (CIA) constraints on R&D investment, consumption, and manufacturing. Our main results can be summarized as follows. Under the CIA constraints on R&D and consumption (the CIA constraint on manufacturing), an increase in the nominal interest rate decreases (increases) R&D and economic growth. We also analyze the optimality of Friedman rule and find that Friedman rule can be suboptimal due to a unique feature of the Schumpeterian model.
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