A number of studies have found little economic impact of board gender diversity on firm performance. We return to this issue in the context of large European firms. Our contribution is twofold. ...First, using information on the gender of CEOs children as a source of exogenous variation in female director appointments, we demonstrate a robust positive effect of female board representation on firm performance. Second, while previous work has considered female representation broadly, we focus on membership of board committees as a proxy for active involvement in corporate governance. We demonstrate economically meaningful positive effects on performance of female representation on board committees. Our evidence is supportive of an economic rationale for increased female representation on corporate boards.
Abstract
In alkaline and neutral MEA CO
2
electrolyzers, CO
2
rapidly converts to (bi)carbonate, imposing a significant energy penalty arising from separating CO
2
from the anode gas outlets. Here we ...report a CO
2
electrolyzer uses a bipolar membrane (BPM) to convert (bi)carbonate back to CO
2
, preventing crossover; and that surpasses the single-pass utilization (SPU) limit (25% for multi-carbon products, C
2+
) suffered by previous neutral-media electrolyzers. We employ a stationary unbuffered catholyte layer between BPM and cathode to promote C
2+
products while ensuring that (bi)carbonate is converted back, in situ, to CO
2
near the cathode. We develop a model that enables the design of the catholyte layer, finding that limiting the diffusion path length of reverted CO
2
to ~10 μm balances the CO
2
diffusion flux with the regeneration rate. We report a single-pass CO
2
utilization of 78%, which lowers the energy associated with downstream separation of CO
2
by 10× compared with past systems.
Summary Background Physician burnout has reached epidemic levels, as documented in national studies of both physicians in training and practising physicians. The consequences are negative effects on ...patient care, professionalism, physicians' own care and safety, and the viability of health-care systems. A more complete understanding than at present of the quality and outcomes of the literature on approaches to prevent and reduce burnout is necessary. Methods In this systematic review and meta-analysis, we searched MEDLINE, Embase, PsycINFO, Scopus, Web of Science, and the Education Resources Information Center from inception to Jan 15, 2016, for studies of interventions to prevent and reduce physician burnout, including single-arm pre-post comparison studies. We required studies to provide physician-specific burnout data using burnout measures with validity support from commonly accepted sources of evidence. We excluded studies of medical students and non-physician health-care providers. We considered potential eligibility of the abstracts and extracted data from eligible studies using a standardised form. Outcomes were changes in overall burnout, emotional exhaustion score (and high emotional exhaustion), and depersonalisation score (and high depersonalisation). We used random-effects models to calculate pooled mean difference estimates for changes in each outcome. Findings We identified 2617 articles, of which 15 randomised trials including 716 physicians and 37 cohort studies including 2914 physicians met inclusion criteria. Overall burnout decreased from 54% to 44% (difference 10% 95% CI 5–14; p<0·0001; I2 =15%; 14 studies), emotional exhaustion score decreased from 23·82 points to 21·17 points (2·65 points 1·67–3·64; p<0·0001; I2 =82%; 40 studies), and depersonalisation score decreased from 9·05 to 8·41 (0·64 points 0·15–1·14; p=0·01; I2 =58%; 36 studies). High emotional exhaustion decreased from 38% to 24% (14% 11–18; p<0·0001; I2 =0%; 21 studies) and high depersonalisation decreased from 38% to 34% (4% 0–8; p=0·04; I2 =0%; 16 studies). Interpretation The literature indicates that both individual-focused and structural or organisational strategies can result in clinically meaningful reductions in burnout among physicians. Further research is needed to establish which interventions are most effective in specific populations, as well as how individual and organisational solutions might be combined to deliver even greater improvements in physician wellbeing than those achieved with individual solutions. Funding Arnold P Gold Foundation Research Institute.
U-net is an image segmentation technique developed primarily for image segmentation tasks. These traits provide U-net with a high utility within the medical imaging community and have resulted in ...extensive adoption of U-net as the primary tool for segmentation tasks in medical imaging. The success of U-net is evident in its widespread use in nearly all major image modalities, from CT scans and MRI to X-rays and microscopy. Furthermore, while U-net is largely a segmentation tool, there have been instances of the use of U-net in other applications. Given that U-net's potential is still increasing, this narrative literature review examines the numerous developments and breakthroughs in the U-net architecture and provides observations on recent trends. We also discuss the many innovations that have advanced in deep learning and discuss how these tools facilitate U-net. In addition, we review the different image modalities and application areas that have been enhanced by U-net.
Abstract
The electrochemical conversion of CO
2
to methane provides a means to store intermittent renewable electricity in the form of a carbon-neutral hydrocarbon fuel that benefits from an ...established global distribution network. The stability and selectivity of reported approaches reside below technoeconomic-related requirements. Membrane electrode assembly-based reactors offer a known path to stability; however, highly alkaline conditions on the cathode favour C-C coupling and multi-carbon products. In computational studies herein, we find that copper in a low coordination number favours methane even under highly alkaline conditions. Experimentally, we develop a carbon nanoparticle moderator strategy that confines a copper-complex catalyst when employed in a membrane electrode assembly. In-situ XAS measurements confirm that increased carbon nanoparticle loadings can reduce the metallic copper coordination number. At a copper coordination number of 4.2 we demonstrate a CO
2
-to-methane selectivity of 62%, a methane partial current density of 136 mA cm
−2
, and > 110 hours of stable operation.
Placental dysfunction underlies major obstetric diseases such as pre-eclampsia and fetal growth restriction (FGR). Whilst there has been a little progress in prophylaxis, there are still no ...treatments for placental dysfunction in normal obstetric practice. However, a combination of increasingly well-described
systems for studying the human placenta, together with the availability of more appropriate animal models of pre-eclampsia and FGR, has facilitated a recent surge in work aimed at repurposing drugs and therapies, developed for other conditions, as treatments for placental dysfunction. This review: (1) highlights potential candidate drug targets in the placenta - effectors of improved uteroplacental blood flow, anti-oxidants, heme oxygenase induction, inhibition of HIF, induction of cholesterol synthesis pathways, increasing insulin-like growth factor II availability; (2) proposes an experimental pathway for taking a potential drug or treatment for placental dysfunction from concept through to early phase clinical trials, utilizing techniques for studying the human placenta
and small animal models, particularly the mouse, for
studies; (3) describes the data underpinning sildenafil citrate and adenovirus expressing vascular endothelial growth as potential treatments for placental dysfunction and summarizes recent research on other potential treatments. The importance of sharing information from such studies even when no effect is found, or there is an adverse outcome, is highlighted. Finally, the use of adenoviral vectors or nanoparticle carriers coated with homing peptides to selectively target drugs to the placenta is highlighted: such delivery systems could improve efficacy and reduce the side effects of treating the dysfunctional placenta.
Aims. We aim to describe the pre-main-sequence and main-sequence evolution of X-ray and extreme-ultaviolet radiation of a solar-mass star based on its rotational evolution starting with a realistic ...range of initial rotation rates. Methods. We derive evolutionary tracks of X-ray radiation based on a rotational evolution model for solar-mass stars and the rotation-activity relation. We compare these tracks to X-ray luminosity distributions of stars in clusters with different ages. Results. We find agreement between the evolutionary tracks derived from rotation and the X-ray luminosity distributions from observations. Depending on the initial rotation rate, a star might remain at the X-ray saturation level for very different time periods, from ≈10 Myr to ≈300 Myr for slow and fast rotators, respectively. Conclusions. Rotational evolution with a spread of initial conditions leads to a particularly wide distribution of possible X-ray luminosities in the age range of 20–500 Myr, before rotational convergence and therefore X-ray luminosity convergence sets in. This age range is crucial for the evolution of young planetary atmospheres and may thus lead to very different planetary evolution histories.
Significance There is evidence that the 2007−2010 drought contributed to the conflict in Syria. It was the worst drought in the instrumental record, causing widespread crop failure and a mass ...migration of farming families to urban centers. Century-long observed trends in precipitation, temperature, and sea-level pressure, supported by climate model results, strongly suggest that anthropogenic forcing has increased the probability of severe and persistent droughts in this region, and made the occurrence of a 3-year drought as severe as that of 2007−2010 2 to 3 times more likely than by natural variability alone. We conclude that human influences on the climate system are implicated in the current Syrian conflict.
Before the Syrian uprising that began in 2011, the greater Fertile Crescent experienced the most severe drought in the instrumental record. For Syria, a country marked by poor governance and unsustainable agricultural and environmental policies, the drought had a catalytic effect, contributing to political unrest. We show that the recent decrease in Syrian precipitation is a combination of natural variability and a long-term drying trend, and the unusual severity of the observed drought is here shown to be highly unlikely without this trend. Precipitation changes in Syria are linked to rising mean sea-level pressure in the Eastern Mediterranean, which also shows a long-term trend. There has been also a long-term warming trend in the Eastern Mediterranean, adding to the drawdown of soil moisture. No natural cause is apparent for these trends, whereas the observed drying and warming are consistent with model studies of the response to increases in greenhouse gases. Furthermore, model studies show an increasingly drier and hotter future mean climate for the Eastern Mediterranean. Analyses of observations and model simulations indicate that a drought of the severity and duration of the recent Syrian drought, which is implicated in the current conflict, has become more than twice as likely as a consequence of human interference in the climate system.
Citizen cooperation with the police can have an important bearing on how effective the police are in performing their duties. Without cooperation, suspects disappear, leads unravel, arrests plummet, ...and cases fail to materialize. In those low-income communities where citizens tend not to report crime, the crime rate is nearly always high (La Vigne, Fontaine, & Dwivedi, 2017), whereas citizens who report victimization experiences to the police are less likely to be victimized in the future than those who do not report victimization experiences to the police (Ranapurwala, Berg, & Casteel, 2016). When victimization experiences are not reported to the police, criminals become emboldened and their inclination to believe they are above the law grows even stronger. Finding ways to encourage the public to cooperate with the police and other law enforcement officials is therefore of cardinal significance when it comes to improving police effectiveness. First, however, we must identify the factors that motivate the public to cooperate with the police. Two such factors, perceived police procedural justice and police legitimacy beliefs, were the focus of the current investigation. This investigation will use the meta-analytic method to examine the univariate associations between procedural justice, legitimacy beliefs, and cooperation with the police in studies conducted over the past 28 years.
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