About 62,000 dead or dying common murres (Uria aalge), the trophically dominant fish-eating seabird of the North Pacific, washed ashore between summer 2015 and spring 2016 on beaches from California ...to Alaska. Most birds were severely emaciated and, so far, no evidence for anything other than starvation was found to explain this mass mortality. Three-quarters of murres were found in the Gulf of Alaska and the remainder along the West Coast. Studies show that only a fraction of birds that die at sea typically wash ashore, and we estimate that total mortality approached 1 million birds. About two-thirds of murres killed were adults, a substantial blow to breeding populations. Additionally, 22 complete reproductive failures were observed at multiple colonies region-wide during (2015) and after (2016-2017) the mass mortality event. Die-offs and breeding failures occur sporadically in murres, but the magnitude, duration and spatial extent of this die-off, associated with multi-colony and multi-year reproductive failures, is unprecedented and astonishing. These events co-occurred with the most powerful marine heatwave on record that persisted through 2014-2016 and created an enormous volume of ocean water (the "Blob") from California to Alaska with temperatures that exceeded average by 2-3 standard deviations. Other studies indicate that this prolonged heatwave reduced phytoplankton biomass and restructured zooplankton communities in favor of lower-calorie species, while it simultaneously increased metabolically driven food demands of ectothermic forage fish. In response, forage fish quality and quantity diminished. Similarly, large ectothermic groundfish were thought to have increased their demand for forage fish, resulting in greater top-predator demands for diminished forage fish resources. We hypothesize that these bottom-up and top-down forces created an "ectothermic vise" on forage species leading to their system-wide scarcity and resulting in mass mortality of murres and many other fish, bird and mammal species in the region during 2014-2017.
Venture capital (VC) firms spent over $25billion funding clean energy technology (cleantech) start-ups from 2006 to 2011. Less than half of that capital was returned; as a result, funding has dried ...up in the cleantech sector. But as the International Energy Agency warns, without new energy technologies, the world cannot cost-effectively confront climate change. In this article, we present the most comprehensive account to date of the cleantech VC boom and bust. Our results aggregate hundreds of investments to calculate the risk and return profile of cleantech, and we compare the outcomes with those of medical and software technology investments. Cleantech posed high risks and yielded low returns to VCs. We conclude that among cleantech investments, “deep technology” investments—in companies developing new hardware, materials, chemistries, or manufacturing processes—consumed the most capital and yielded the lowest returns. We propose that broader support from policymakers, corporations, and investors is needed to underpin new innovation pathways for cleantech.
•A venture capital boom in clean energy technology went bust in 2008.•Cleantech offered high risk and low returns to investors.•Poor performance due to long development time for materials and chemicals.•Breakthrough energy innovations are often not a match for venture capital.•More research on alternative financing and support for cleantech is needed.
Minimising the transport of corrosive reactants such as carbon dioxide, hydrogen sulfide and chloride ions to the surfaces of carbon steel pipes by the use of polymer barrier layers is of major ...interest in the oil and gas sector. In these applications, there is a requirement to assess the performance of these barrier layers although it is difficult to perform long-term predictions of barrier properties from the results of short-term measurements. New methodologies have been successfully developed to study the permeability of carbon dioxide (CO
) and hydrogen sulfide (H
S) through polymer layers under variable conditions of elevated temperatures of 100 °C and pressures of the order of 400 barg. In situ variation of the temperature and the inlet pressure of the gas (or gas mixture) allowed the activation energy and pressure dependence of the permeability to be determined without outgassing of the specimen. These methodologies have been applied to the measurement of the permeability of moulded polyphenylene sulfide (PPS) to supercritical CO
in the presence of H
S. The diffusion coefficients of sodium chloride and potassium chloride through both PPS and polyether ether ketone (PEEK) at ambient temperature and pressure have also been measured.
In the past decade, the perovskite solar cell (PSC) has attracted tremendous attention thanks to the substantial efforts in improving the power conversion efficiency from 3.8% to 25.5% for ...single‐junction devices and even perovskite‐silicon tandems have reached 29.15%. This is a result of improvement in composition, solvent, interface, and dimensionality engineering. Furthermore, the long‐term stability of PSCs has also been significantly improved. Such rapid developments have made PSCs a competitive candidate for next‐generation photovoltaics. The electron transport layer (ETL) is one of the most important functional layers in PSCs, due to its crucial role in contributing to the overall performance of devices. This review provides an up‐to‐date summary of the developments in inorganic electron transport materials (ETMs) for PSCs. The three most prevalent inorganic ETMs (TiO2, SnO2, and ZnO) are examined with a focus on the effects of synthesis and preparation methods, as well as an introduction to their application in tandem devices. The emerging trends in inorganic ETMs used for PSC research are also reviewed. Finally, strategies to optimize the performance of ETL in PSCs, effects the ETL has on J–V hysteresis phenomenon and long‐term stability with an outlook on current challenges and further development are discussed.
In the past decade, the perovskite solar cell (PSC) has attracted tremendous attention. The electron transport layer (ETL) is one of the most important functional layers in PSCs. This review provides an up‐to‐date summary of the developments in inorganic electron transport materials for PSCs. Strategies to optimize the ETL, an outlook on current challenges and further development are discussed.
Providing the direct experimental evidence for confirming active and stable phase in cobalt-based electrocatalysts for oxygen evolution reaction (OER) in alkaline medium is crucial to design and ...fabricate high-performance electrocatalysts. Herein, we report the in situ fabrication of pure cobalt oxyhydroxide (CoOOH) phase with highly porous structures during OER testing process, which exhibits outstanding performance for OER with a low overpotential of 245 mV at 10 mA cm−2 and retain stable catalytic activity for 250 h with no appreciable decay. Experimental characterizations revealed that the superior catalytic activity of as-formed CoOOH phase mainly arises from the highly porous structures, which endows the electrocatalyst with high specific surface area (∼200 m2 g−1), numerous accessible channels and abundant active sites. Evidence has been produced showing that the in situ formed pure CoOOH is the active and stable phase in cobalt-based electrocatalysts for OER in alkaline medium. In addition, the synthetic strategy applied here could provide a novel way to fabricate nanoporous structures under mild conditions using electrochemical oxidation method.
Pulmonary hypertension (PH) increases the work of the right ventricle (RV) and causes right-sided heart failure. This study examined RV mitochondrial function and ADP transfer in PH animals advancing ...to right heart failure, and investigated a potential therapy with the specific β1-adrenergic-blocker metoprolol. Adult Wistar rats (317 ± 4 g) were injected either with monocrotaline (MCT, 60 mg kg-1) to induce PH, or with an equivalent volume of saline for controls (CON). At three weeks post-injection the MCT rats began oral metoprolol (10 mg kg-1 day-1-) or placebo treatment until heart failure was observed in the MCT group. Mitochondrial function was then measured using high-resolution respirometry from permeabilised RV fibres. Relative to controls, MCT animals had impaired mitochondrial function but maintained coupling between myofibrillar ATPases and mitochondria, despite an increase in ADP diffusion distances. Cardiomyocytes from the RV of MCT rats were enlarged, primarily due to an increase in myofibrillar protein. The ratio of mitochondria per myofilament area was decreased in both MCT groups (p ≤ 0.05) in comparison to control (CON: 1.03 ± 0.04; MCT: 0.74 ± 0.04; MCT + BB: 0.74 ± 0.03). This not only implicates impaired energy production in PH, but also increases the diffusion distance for metabolites within the MCT cardiomyocytes, adding an additional hindrance to energy supply. Together, these changes may limit energy supply in MCT rat hearts, particularly at high cardiac workloads. Metoprolol treatment did not delay the onset of heart failure symptoms, improve mitochondrial function, or regress RV hypertrophy.
Summary
Patients with primary antibody deficiency syndromes such as X‐linked agammaglobulinemia (XLA) and common variable immunodeficiency (CVID) are at increased risk of severe and invasive ...infection. Viral infection in these populations has been of increasing interest as evidence mounts that viruses contribute significant morbidity and mortality: this is mediated both directly and via aberrant immune responses. We explain the importance of the humoral immune system in defence against viral pathogens before highlighting several significant viral syndromes in patients with antibody deficiency.
We explore historical cases of hepatitis C via contaminated immunoglobulin products, the predisposition to invasive enteroviral infections, prolonged excretion of vaccine‐derived poliovirus, the morbidity of chronic norovirus infection, and recent literature revealing the importance of respiratory viral infections. We discuss evidence that herpesviruses may play a role in driving the inflammatory disease seen in a subset of patients. We explore the phenomenon of within‐host evolution during chronic viral infection and the potential emergence of new pathogenic strains. We highlight novel and emerging viruses identified via deep sequencing techniques. We describe the treatment strategies that have been attempted in all these scenarios and the urgent outstanding questions for research.
The cardiac cytoskeletal components are integral to cardiomyocyte function and are responsible for contraction, sustaining cell structure, and providing scaffolding to direct signaling. Cytoskeletal ...components have been implicated in cardiac pathology; however, less attention has been paid to age-related modifications of cardiac cytoskeletal components and how these contribute to dysfunction with increased age. Moreover, significant sex differences in cardiac aging have been identified, but we still lack a complete understanding to the mechanisms behind these differences. This review summarizes what is known about how key cardiomyocyte cytoskeletal components are modified because of age, as well as reported sex-specific differences. Thorough consideration of both age and sex as integral players in cytoskeletal function may reveal potential avenues for more personalized therapeutics.
To estimate the global burden of nontyphoidal Salmonella gastroenteritis, we synthesized existing data from laboratory-based surveillance and special studies, with a hierarchical preference to (1) ...prospective population-based studies, (2) dquo;multiplier studies, dquo; (3) disease notifications, (4) returning traveler data, and (5) extrapolation. We applied incidence estimates to population projections for the 21 Global Burden of Disease regions to calculate regional numbers of cases, which were summed to provide a global number of cases. Uncertainty calculations were performed using Monte Carlo simulation. We estimated that 93.8 million cases (5th to 95th percentile, 61.8–131.6 million) of gastroenteritis due to Salmonella species occur globally each year, with 155,000 deaths (5th to 95th percentile, 39,000–303,000 deaths). Of these, we estimated 80.3 million cases were foodborne. Salmonella infection represents a considerable burden in both developing and developed countries. Efforts to reduce transmission of salmonellae by food and other routes must be implemented on a global scale.
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