1,168 research outputs found
On Infrared Excesses Associated With Li-Rich K Giants
Infrared (IR) excesses around K-type red giants (RGs) have previously been
discovered using IRAS data, and past studies have suggested a link between RGs
with overabundant Li and IR excesses, implying the ejection of circumstellar
shells or disks. We revisit the question of IR excesses around RGs using higher
spatial resolution IR data, primarily from WISE. Our goal was to elucidate the
link between three unusual RG properties: fast rotation, enriched Li, and IR
excess. We have 316 targets thought to be K giants, about 40% of which we take
to be Li-rich. In 24 cases with previous detections of IR excess at low spatial
resolution, we believe that source confusion is playing a role, in that either
(a) the source that is bright in the optical is not responsible for the IR
flux, or (b) there is more than one source responsible for the IR flux as
measured in IRAS. We looked for IR excesses in the remaining sources,
identifying 28 that have significant IR excesses by ~20 um (with possible
excesses for 2 additional sources). There appears to be an intriguing
correlation in that the largest IR excesses are all in Li-rich K giants, though
very few Li-rich K giants have IR excesses (large or small). These largest IR
excesses also tend to be found in the fastest rotators. There is no correlation
of IR excess with the carbon isotopic ratio, 12C/13C. IR excesses by 20 um,
though relatively rare, are at least twice as common among our sample of
Li-rich K giants. If dust shell production is a common by-product of Li
enrichment mechanisms, these observations suggest that the IR excess stage is
very short-lived, which is supported by theoretical calculations. Conversely,
the Li-enrichment mechanism may only occasionally produce dust, and an
additional parameter (e.g., rotation) may control whether or not a shell is
ejected.Comment: 73 pages, 21 figures (some of which substantially degraded to meet
arXiv file size requirements), accepted to AJ. Full table 1 (and full-res
figures) available upon request to the autho
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The impact of air-sea coupling and ocean biases on the seasonal cycle of southern West African precipitation
The biannual seasonal rainfall regime over the southern part of West Africa is characterised by two wet seasons, separated by the `Little Dry Season' in July-August. Lower rainfall totals during this intervening dry season may be detrimental for crop yields over a region with a dense population that depends on agricultural output. Coupled Model Intercomparison Project Phase 5 (CMIP5) models do not correctly capture this seasonal regime, and instead generate a single wet season, peaking at the observed timing of the Little Dry Season. Hence, the realism of future climate projections over this region is questionable. Here, the representation of the Little Dry Season in coupled model simulations is investigated, to elucidate factors leading to this misrepresentation. The Global Ocean Mixed Layer configuration of the Met Office Unified Model is particularly useful for exploring this misrepresentation, as it enables separating the effects of coupled model ocean biases in different ocean basins while maintaining air-sea coupling. Atlantic Ocean SST biases cause the incorrect seasonal regime over southern West Africa.Upper level descent in August reduces ascent along the coastline, which is associated with the observed reduction in rainfall during the Little Dry Season. When coupled model Atlantic Ocean biases are introduced, ascent over the coastline is deeper and rainfall totals are higher during July-August. Hence, this study indicates detrimental impacts introduced by Atlantic Ocean biases, and highlights an area of model development required for production of meaningful climate change projections over the West Africa region
VISIT-TS: A multimedia tool for population studies on tic disorder
Population-based assessment of Tourette syndrome (TS) and other tic disorders produces a paradox. On one hand, ideally diagnosis of tic disorders requires expert observation. In fact, diagnostic criteria for TS explicitly require expert assessment of tics for a definite diagnosis. On the other hand, large-scale population surveys with expert assessment of every subject are impracticable. True, several published studies have successfully used expert assessment to find tic prevalence in a representative population (e.g. all students in a school district). However, extending these studies to larger populations is daunting. We created a multimedia tool to demonstrate tics to a lay audience, discuss their defining and common attributes, and address features that differentiate tics from other movements and vocalizations. A first version was modified to improve clarity and to include a more diverse group in terms of age and ethnicity. The result is a tool intended for epidemiological research. It may also provide additional benefits, such as more representative minority recruitment for other TS studies and increased community awareness of TS
Hippocampal volume in Provisional Tic Disorder predicts tic severity at 12-month follow-up
Previous studies have investigated differences in the volumes of subcortical structures (e.g., caudate nucleus, putamen, thalamus, amygdala, and hippocampus) between individuals with and without Tourette syndrome (TS), as well as the relationships between these volumes and tic symptom severity. These volumes may also predict clinical outcome in Provisional Tic Disorder (PTD), but that hypothesis has never been tested. This study aimed to examine whether the volumes of subcortical structures measured shortly after tic onset can predict tic symptom severity at one-year post-tic onset, when TS can first be diagnosed. We obtained T1-weighted structural MRI scans from 41 children with PTD (25 with prospective motion correction (vNavs)) whose tics had begun less than 9 months (mean 4.04 months) prior to the first study visit (baseline). We re-examined them at the 12-month anniversary of their first tic (follow-up), assessing tic severity using the Yale Global Tic Severity Scale. We quantified the volumes of subcortical structures using volBrain software. Baseline hippocampal volume was correlated with tic severity at the 12-month follow-up, with a larger hippocampus at baseline predicting worse tic severity at follow-up. The volumes of other subcortical structures did not significantly predict tic severity at follow-up. Hippocampal volume may be an important marker in predicting prognosis in Provisional Tic Disorder
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Groundwater and resilience to drought in the Ethiopian Highlands
During drought, groundwater is often relied on to provide secure drinking water, particularly in rural Africa where other options are limited. However, the technology chosen to access groundwater significantly affects local water security. Here we examine the performance of springs, hand-dug- wells and boreholes in northern Ethiopia through direct high frequency monitoring of water-levels (n=19) and water quality (n=48) over an 18-month period and gathering information on community impacts of declining water access during the El Niño 2015/2016 drought. We found that shallow boreholes equipped with handpumps were the most reliable water supply, recovering within hours to daily abstraction throughout all conditions. Recovery and performance of most hand-dug-wells and springs declined significantly throughout the extended dry season, although in specific aquifer conditions they were reliable. All sources types had negligible measured contamination from Thermo-tolerant Coliforms through the extended dry season, but were contaminated during the rains marking drought cessation. Boreholes were least affected, median 10 cfu/100ml, compared to 190 and 59 cfu/100ml for hand-dug-wells and springs respectively. Many communities who relied solely on springs, wells or rivers experienced severe water shortage in the El Niño drought with mean daily collection times up to 12 hours and volumes collected reducing to 3-5 litre- per-capita- per-day. This led to reports of violent conflict, missed meals, reduction in school attendance and farm activity and increased health impacts. From this study there is a clear case for improving resilience to drought by installing boreholes equipped with handpumps where feasible even if collection times are >30 minutes
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Subseasonal precipitation prediction for Africa: forecast evaluation and sources of predictability
This paper evaluates sub-seasonal precipitation forecasts for Africa using hindcasts from three models (ECMWF, UKMO, and NCEP) participating in the Subseasonal to Seasonal (S2S) prediction project. A variety of verification metrics are employed to assess weekly precipitation forecast quality at lead times of one to four weeks ahead (Weeks 1-4) during different seasons. Overall, forecast evaluation indicates more skilful predictions for ECMWF over other models and for East Africa over other regions. Deterministic forecasts show substantial skill reduction in Weeks 3-4 linked to lower association and larger underestimation of predicted variance compared to Weeks 1-2. Tercile-based probabilistic forecasts reveal similar characteristics for extreme categories and low quality in the near-normal category. Although discrimination is low in Weeks 3-4, probabilistic forecasts still have reasonable skill, especially in wet regions during particular rainy seasons. Forecasts are found to be over-confident for all weeks, indicating the need to apply calibration for more reliable predictions. Forecast quality within the ECMWF model is also linked to the strength of climate drivers’ teleconnections, namely El Niño-Southern Oscillation, Indian Ocean Dipole, and the Madden-Julian Oscillation. The impact of removing all driver-related precipitation regression patterns from observations and hindcasts shows reduction of forecast quality compared to including all drivers’ signals, with more robust effects in regions where the driver strongly relates to precipitation variability. Calibrating forecasts by adding observed regression patterns to hindcasts provides improved forecast associations particularly linked to the Madden-Julian Oscillation. Results from this study can be used to guide decision-makers and forecasters in disseminating valuable forecasting information for different societal activities in Africa
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Possible futures for groundwater in Burkina Faso under a changing climate
This narrative describes three possible future scenarios for water resources in Burkina Faso and the human and socio-economic impacts that might be experienced by people living in rural areas. The narratives aim to stimulate discussion towards realistic policy responses and the decision support tools needed to assist future planning needs. It is important to recognise that the scenarios do not represent every possible outcome projected by hydroclimate models, and resulting impacts will be contextualised by local circumstances. See here for information about BRAVE (www.walker.ac.uk) and the UPGro programme: upgro.org/consortium/brave2/
1973 Research Progress Reports, Fruit and Vegetable Processing and Food Technology
Evaluation of snap bean varieties for processing / Wilbur A. Gould -- Evaluation of tomato cultivars for processing / W. A. Gould, James Black, Emily Korensky, Ruth Stillabower, and Stanley Z. Berry -- Commercial tomato cultivar evaluation / Wilbur A. Gould, Jerry Wright, in cooperation with Stanley Berry, Marion White, Tip Top Canning Co., Beckman and Gast Company and Hirzel Canning Co. -- Relationship of USDA D6 tomato colorimeter to AGTRON E-5 / Wilbur A. Gould and Jerry Wright -- Effects of food additives on the quality of canned tomatoes / Wilbur A. Gould, Jacquelyn Gould, and James Black -- Effects of food additives on the quality of canned tomato juice / Wilbur A. Gould, Ruth Stillabower, Jacquelyn Gould and James Black -- Retention of ascorbic acid in fortified tomato juice ; Effect of storage time and temperature and added ascorbic acid on the total acid and pH of tomato juice / Gerald G. Pope and Wilbur A. Gould -- Cell wall components and tomato juice consistency / David E. Crean -- Lipid content of cabbage & sauerkraut / Andrew C. Peng -- Canned rice-tomatoes / Teung Chin and Wilbur A. Gould -- Development of a canned pecan pie filling / W. A. Gould and S. Perryman -- A new soybean food from tempeh / Nasruddin Iljas, Wilbur A. Gould and Andrew C. Peng -- Rehabilitation and recycling spend cucumber pickling brines / J. R. Geisman and R. E. Henne -- Evaluation of several grape cultivars for wine making / James F. Gallande
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