2,953 research outputs found
The 'Lindholme Advance' and the extent of the Last Glacial Maximum in the Vale of York
The limits of the glacier that occupied the southwest part of the southern Vale of York at the Last Glacial Maximum are defined in relation to recent temporary exposures at Lindholme and previous regional mapping by Geoff Gaunt. Erratic content of associated diamicts indicates sources in the Yorkshire Dales, over Stainmore and along the Permo-Triassic outcrops on the west side of the Vale of York. The advance is dated to an episode associated with a high level of pro-glacial Lake Humber within the Last Glacial Maximum. Lidar imagery suggests that the northeastern ice limit is concealed beneath later alluvium of the rivers Ouse and Trent
Effect of risedronate on joint structure and symptoms of knee osteoarthritis: results of the BRISK randomized, controlled trial [ISRCTN01928173]
To determine the efficacy and safety of risedronate in patients with knee osteoarthritis (OA), the British study of risedronate in structure and symptoms of knee OA (BRISK), a 1-year prospective, double-blind, placebo-controlled study, enrolled patients (40–80 years of age) with mild to moderate OA of the medial compartment of the knee. The primary aims were to detect differences in symptoms and function. Patients were randomized to once-daily risedronate (5 mg or 15 mg) or placebo. Radiographs were taken at baseline and 1 year for assessment of joint-space width using a standardized radiographic method with fluoroscopic positioning of the joint. Pain, function, and stiffness were assessed using the Western Ontario and McMaster Universities (WOMAC) OA index. The patient global assessment and use of walking aids were measured and bone and cartilage markers were assessed. The intention-to-treat population consisted of 284 patients. Those receiving risedronate at 15 mg showed improvement of the WOMAC index, particularly of physical function, significant improvement of the patient global assessment (P < 0.001), and decreased use of walking aids relative to patients receiving the placebo (P = 0.009). A trend towards attenuation of joint-space narrowing was observed in the group receiving 15 mg risedronate. Eight percent (n = 7) of patients receiving placebo and 4% (n = 4) of patients receiving 5 mg risedronate exhibited detectable progression of disease (joint-space width ≥ 25% or ≥ 0.75 mm) versus 1% (n = 1) of patients receiving 15 mg risedronate (P = 0.067). Risedronate (15 mg) significantly reduced markers of cartilage degradation and bone resorption. Both doses of risedronate were well tolerated. In this study, clear trends towards improvement were observed in both joint structure and symptoms in patients with primary knee OA treated with risedronate
Optoacoustic solitons in Bragg gratings
Optical gap solitons, which exist due to a balance of nonlinearity and
dispersion due to a Bragg grating, can couple to acoustic waves through
electrostriction. This gives rise to a new species of ``gap-acoustic'' solitons
(GASs), for which we find exact analytic solutions. The GAS consists of an
optical pulse similar to the optical gap soliton, dressed by an accompanying
phonon pulse. Close to the speed of sound, the phonon component is large. In
subsonic (supersonic) solitons, the phonon pulse is a positive (negative)
density variation. Coupling to the acoustic field damps the solitons'
oscillatory instability, and gives rise to a distinct instability for
supersonic solitons, which may make the GAS decelerate and change direction,
ultimately making the soliton subsonic.Comment: 5 pages, 3 figure
Traditional Knowledge of the Ecology of Beluga Whales (Delphinapterus leucas) in the Eastern Chukchi and Northern Bering Seas, Alaska
Traditional ecological knowledge (TEK) has been used opportunistically in biological studies of beluga whales (Delphinapterus leucas) in Alaska, but no previous research has documented this knowledge systematically. This first such effort, which took place in Norton Bay, Buckland, and Point Lay, Alaska, provided descriptions of migratory and local movements, feeding, calving, ecological interactions, and human influences on distribution and behavior. The results are consistent with those of previous studies but add considerable detail, including descriptions of avoidance and habituation responses to anthropogenic noise, which appear to depend in part on association with hunting activities. Making greater use of TEK will benefit both research and management by providing better information and by expanding the collaborative process developed through co-management. On a utilisé le savoir écologique traditionnel (SET) quand l'occasion se présentait, dans le cadre des études biologiques portant sur le bélouga (Delphinapterus leucas) en Alaska, mais ce savoir n'a jamais fait l'objet d'une étude systématique. Cette première tentative en ce sens, qui a été réalisée à Norton Bay, Buckland et Point Lay, en Alaska, a fourni des descriptions de déplacements migratoires et locaux, de nutrition, de mise bas, d'interactions écologiques et d'influences humaines sur la distribution et le comportement. Les résultats concordent avec ceux d'études précédentes, mais apportent de nombreux détails, y compris la description des réactions d'évitement et d'accoutumance au bruit anthropique, qui semble dépendre en partie de l'association avec les activités cynégétiques. Une plus grande utilisation du SET profitera à la fois à la recherche et à la gestion en fournissant de meilleures informations et en développant plus à fond le processus de collaboration créé par la cogestion
Preliminary archaeoentomological analyses of permafrost-preserved cultural layers from the pre-contact Yup’ik Eskimo site of Nunalleq, Alaska : implications, potential and methodological considerations
Acknowledgements Site excavation and samples collection were conducted by archaeologists from the University of Aberdeen, with the help of archaeologists and student excavators from the University of Aberdeen University of Alaska Fairbanks and Bryn Mawr College, Kuskokwim Campus, College of Rural Alaska and residents of Quinhagak and Mekoryuk. This study is funded through AHRC grant to the project ‘Understanding Cultural Resilience and Climate Change on the Bering Sea through Yup’ik Ecological Knowledge, Lifeways, Learning and Archaeology’ to Rick Knecht, Kate Britton and Charlotta Hillderal (University of Aberdeen; AH/K006029/1). Thanks are due to Qanirtuuq Inc. and Quinhagak, Alaska for sampling permissions and to entomologists working at the CNC in Ottawa for allowing access to reference collections of beetles, lice and fleas. Yves Bousquet, Ales Smetana and Anthony E. Davies are specially acknowledged for their help with the identification of coleopteran specimens. Finally, we would also like to thank Scott Elias for useful comments on the original manuscript.Peer reviewedPublisher PD
Density and distribution of western chimpanzees around a bauxite deposit in the Boé Sector, Guinea-Bissau
Funding: partial support by CEAUL (funded by FCT - Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2019) (TAM).The Boé sector in southeast Guinea‐Bissau harbors a population of western chimpanzees (Pan troglodytes verus) that inhabits a mosaic of forest and savanna. The Boé sector contains a substantial bauxite deposit in a region called Ronde Hill, and there are plans for the construction of a mine, which may endanger the chimpanzee population. In 1‐week survey in May 2013, we used the standing crop nest counts method to obtain the number of chimpanzee nests and from that estimate the density and abundance of chimpanzees. We carried out five 1‐km line transects that covered the bauxite deposit and surrounding valleys. We used density surface modeling to analyze habitat preferences, then predicted chimpanzee nest density and distribution based on environmental variables. We found the projected location of the mine partially coincides with an area of high predicted abundances of chimpanzee nests and is surrounded by highly suitable areas for chimpanzees (northeast and southwest). We conclude the mine could have significant direct and indirect effects on this population of chimpanzees whose impacts must be carefully considered and properly mitigated if the mine is built.PostprintPeer reviewe
Interventions to promote exclusive breastfeeding among young mothers : a systematic review and meta-analysis
Background: Exclusive breastfeeding rates in many high-income countries are considerably lower than the World Health Organization recommendations. Younger mothers are less likely than older mothers to exclusively breastfeed or to exclusively breastfeed for a long duration. This systematic review explores interventions to increase the rate of exclusive breastfeeding among young mothers in high-income countries. Methods: A systematic search of the following databases was completed in August 2020: CINAHL, PubMed, MEDL INE, ProQuest, PsychInfo, Web of Science, Cochrane, Scopus and Embase. A manual search of the reference lists of all the included studies and published systematic reviews was also performed. The Cochrane Collaboration Risk of Bias Tool was used to assess the quality of the included studies. A random effects model meta-analyses was applied. Heterogeneity of outcomes between the studies was assessed using both the χ 2 test and the I2 statistic. Results: Of 955 records identified in the search, 392 duplicates were removed, and nine studies met the inclusion criteria. Seven studies were randomised controlled trial (RCTs) and two were quasi-experimental in design. Eight were conducted in the United States. The interventions included peer counselling, telephone support, massage, gift packs, financial incentive and antenatal education. Most studies included a combination of strategies, peer counselling being the most common. A meta-analysis of four of nine included studies did not detect a difference in rate of exclusive breastfeeding to 3 months postpartum (RR 1.44; 95% CI 0.82, 2.55; p = 0.204). This review is limited by the relatively few studies which met the inclusion criteria and the small sample sizes of most included studies. High rates of attrition and formula supplementation among the participants made it difficult to detect a statistically significant effect. Consistency in follow up times would enable more studies to be included in a meta-analysis. Conclusions: Peer counselling was the most promising strategy associated with higher rates of exclusive breastfeeding. However, further studies are needed to understand the breastfeeding experiences of young mothers. Young mothers should be targeted specifically in intervention studies
A revision of the British Chronostratigraphy within the Last Glacial-Interglacial Cycle based on new evidence from Arclid, Cheshire UK
Of the 24 Greenland interstadials (GI) in the Last Glacial-interglacial cycle (LGIC) only five are conventionally recognised in Britain. This paper aims to improve understanding of the LGIC in Britain from a site at Arclid, Cheshire. Sediments were characterised and luminescence used to establish a chronology. This found that the Chelford Sand Formation spans 77-47 ka with sand deposited initially by aeolian but later by fluvial transportation. Coleoptera and Diptera from the basal peat lens provided a reconstruction for a heather-rich heathland environment grazed by large herbivores, with summer temperatures between 13-18° C, and winter temperatures between -14 and 1°C. Flies included the earliest records of the blood-sucking horsefly Haematopota pluvialis, and the soldierfly Chloromyia formosa. The overlying Stockport Sand Formation was deposited fluvioglacially between 47-41 ka with the upper Stockport Till formed by the advance of the last British icesheet after ~33 ka. Stenothermic beetle analysis from Arclid indicate similarities with results from other British mid LGIC sites, some of which are at or beyond the limit of radiocarbon dating and may be of a similar age to Arclid. Basal organic sediments found at Arclid along with other reassigned sites are proposed as a new Arclid Interstadial. A revised British LGIC chronostratigraphy has the Wretton, Chelford and Brimpton Interstadials and the previously suggested but not widely recognised Cassington Interstadial. The Arclid Interstadial occurred after these, but prior to the Upton Warren Interstadial complex. This closes the previous gap in interstadials between the Brimpton Interstadial and the Upton Warren Interstadial complex within the British chronostratigraphy
Bioarchaeological and Climatological Evidence for the Fate of Norse Farmers in Medieval Greenland
Greenland, far north land of the Atlantic, has often been beyond the limit of European farming settlement. One of its Norse settlements, colonized just before AD 1000, is — astonishingly — not even at the southern tip, but a way up the west coast, the \u27Western Settlement\u27. Environmental studies show why its occupation came to an end within five centuries, leaving Greenland once more a place of Arctic-adapted hunters
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