Arctic terrestrial ecosystems are major global sources of methane (CH 4 ); hence, it is important to understand the seasonal and climatic controls on CH 4 emissions from these systems. Here, we report year-round CH 4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥50% of the annual CH 4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the "zero curtain" period, when subsurface soil temperatures are poised near 0°C. The zero curtain may persist longer than the growing season, and CH 4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH 4 derived from aircraft data demonstrate the large spatial extent of late season CH 4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH 4 y −1 , ∼25% of global emissions from extratropical wetlands, or ∼6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH 4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.permafrost | aircraft | fall | winter | warming E missions of methane (CH 4 ) from Arctic terrestrial ecosystems could increase dramatically in response to climate change (1-3), a potentially significant positive feedback on climate warming. High latitudes have warmed at a rate almost two times faster than the Northern Hemisphere mean over the past century, with the most intense warming in the colder seasons (4) [up to 4°C in winter in 30 y (5)]. Poor understanding of controls on CH 4 emissions outside of the summer season (6-10) represents a large source of uncertainty for the Arctic CH 4 budget. Warmer air temperatures and increased snowfall can potentially increase soil temperatures and deepen the seasonal thawed layer, stimulating CH 4 and CO 2 emissions from the vast stores of labile organic matter in the Arctic (11). The overwhelming majority of prior studies of CH 4 fluxes in the Arctic have been carried out during the summer months (12-15). However, the fall, winter, and spring months represent 70-80% of the year in the Arctic and have been shown to have significant emissions of CO 2 (16-18). The few measurements of CH 4 fluxes in the Arctic that extend into the fall (6, 7, 9, 10) show complex patterns of CH 4 emissions, with a number indicating high fluxes (7, 10). Winter and early spring data appear to be absent in Arctic tundra over continuous permafrost.Beginning usually in late August or early September, the...

No abstract

COVID‐19 research from China suggests health care workers are at risk of distress, have specific concerns, and need support. It remains unknown whether findings are applicable to UK health care staff and whether psychological support based on generic approaches is effective. We administered an online survey at a leading neuroscience hospital in the UK to examine how individual staff characteristics contribute to distress, concerns, and interventions most valued during the COVID‐19 pandemic. We found a high incidence of distress, particularly in females and staff with previous mental health history. Concerns fell into three factors: ‘risk of infection’, ‘work challenges’, and ‘social change’, and were affected by professional role and contact with COVID‐19 patients. These three factors predicted distress. Psychological support and clear updates were deemed most useful, with specific needs affected by age, professional role, and contact with COVID‐19 patients. This is the first documentation of a high incidence of psychological distress predicted by three types of concerns in health care workers of a neuroscience hospital. Distress, concerns, and interventions most valued were all affected by individual staff characteristics. These findings highlight the importance of providing stratified, one to one support interventions, tailored to professional group, and background, rather than more generic approaches. Practitioner points The COVID‐19 pandemic has resulted in a high incidence of psychological distress in UK health care staff. Distress, concerns, and interventions most valued are influenced by individual staff characteristics. Stratified, one‐to‐one support interventions, tailored to professional group, and background, rather than more generic approaches for stress reduction and resilience, are crucial.

The Cognitive Estimation Test (CET) is widely used by clinicians and researchers to assess the ability to produce reasonable cognitive estimates. Although several studies have published normative data for versions of the CET, many of the items are now outdated and parallel forms of the test do not exist to allow cognitive estimation abilities to be assessed on more than one occasion. In the present study, we devised two new 9-item parallel forms of the CET. These versions were administered to 184 healthy male and female participants aged 18–79 years with 9–22 years of education. Increasing age and years of education were found to be associated with successful CET performance as well as gender, intellect, naming, arithmetic and semantic memory abilities. To validate that the parallel forms of the CET were sensitive to frontal lobe damage, both versions were administered to 24 patients with frontal lobe lesions and 48 age-, gender- and education-matched controls. The frontal patients’ error scores were significantly higher than the healthy controls on both versions of the task. This study provides normative data for parallel forms of the CET for adults which are also suitable for assessing frontal lobe dysfunction on more than one occasion without practice effects.

A long-standing ambition in ecosystem science has been to understand the relationship between ecosystem community composition, structure and function. Differential water use and hydraulic redistribution have been proposed as one mechanism that might allow for the coexistence of overstory woody plants and understory grasses. Here, we investigated how patterns of hydraulic redistribution influence overstory and understory ecophysiological function and how patterns vary across timescales of an individual precipitation event to an entire growing season. To this end, we linked measures of sap flux within lateral and tap roots, leaf-level photosynthesis, ecosystem-level carbon exchange and soil carbon dioxide efflux with local meteorology data. The hydraulic redistribution regime was characterized predominantly by hydraulic descent relative to hydraulic lift. We found only a competitive interaction between the overstory and understory, regardless of temporal time scale. Overstory trees used nearly all water lifted by the taproot to meet their own transpirational needs. Our work suggests that alleviating water stress is not the reason we find grasses growing in the understory of woody plants; rather, other stresses, such as excessive light and temperature, are being ameliorated. As such, both the two-layer model and stress gradient hypothesis need to be refined to account for this coexistence in drylands.

No abstract

Reduced inattentional blindness rates under load in ASD suggests higher perceptual capacity is a core feature, present from childhood and leading to superior performance in various measures of perception and attention.

This survey provides information about current case management practices for children with ABI in Australia. Detailing what case managers do is a first step towards developing controlled research designs which are required to demonstrate whether case management is effective in terms of clinical outcomes and cost-benefit.