158 research outputs found
Effects of Gas Flaring on the Behavior of Night-migrating Birds at an Artificial Oil-production Island, Arctic Alaska
We studied movement rates and the general flight behavior of bird flocks seen on radar and recorded visually at Northstar Island, Arctic Alaska, from 13 to 27 September 2002. Most of this period (13 â 19 and 21 â 27 September) had no gas-flaring events, but a major gas-flaring event occurred on the night of 20 September. Movement rates of targets on radar and of bird flocks recorded visually in the first ~50% â 60% of the night were much lower during the non-flaring period than during the night of flaring, whereas rates in the last ~40% â 50% of the night were similar in all periods. The general flight behavior of birds also differed significantly, with higher percentages of both radar targets and bird flocks exhibiting straight-line (directional) flight behaviors during the non-flaring periods and higher percentages of radar targets and bird flocks exhibiting non-straight-line (erratic and circling) flight behaviors during the gas-flaring period. During the night of gas flaring, the bright illumination appeared to have an effect only after sunset, when flocks of birds circled the island after being drawn in from what appeared to be a substantial distance from the island. On both radar and visual sampling, the number of bird flocks approaching the island declined over the evening, and the attractiveness of the light from flaring appeared to decline. The visibility of the moon appeared to have little effect on the behavior of birds. Because illumination from extensive gas-flaring is such a strong attractant to migrating birds and because most bird flocks fly at low altitudes over the water, flaring booms on coastal and offshore oil-production platforms in Arctic Alaska should be positioned higher than the mean flight altitudes of migrating birds to reduce the chances of incineration.Nous avons Ă©tudiĂ© les taux de dĂ©placement et le comportement de vol gĂ©nĂ©ral des troupeaux dâoiseaux captĂ©s par radar ou consignĂ©s visuellement Ă lâĂźle Northstar, dans lâAlaska de lâArctique, du 13 au 27 septembre 2002. Pendant presque toute cette pĂ©riode (du 13 au 19 et du 21 au 27 septembre), il nây a pas eu de brĂ»lage de gaz Ă la torche, mais la nuit du 20 septembre, il y a eu un important brĂ»lage de gaz Ă la torche. Les taux de dĂ©placement des cibles radar et des troupeaux dâoiseaux consignĂ©s visuellement pendant la premiĂšre tranche dâenviron 50 % Ă 60 % de la nuit Ă©taient beaucoup moins Ă©levĂ©s pendant la pĂ©riode oĂč il nây avait pas de brĂ»lage Ă la torche que pendant la nuit oĂč il y a eu brĂ»lage Ă la torche, tandis que pendant la deuxiĂšme tranche dâenviron 40 % Ă 50 % de la nuit, les taux de dĂ©placement Ă©taient semblables pendant toutes les pĂ©riodes. Le comportement de vol gĂ©nĂ©ral des oiseaux a Ă©galement affichĂ© une diffĂ©rence considĂ©rable. De plus grands pourcentages de cibles radar et de troupeaux dâoiseaux adoptaient un comportement de vol rectiligne (direct) pendant les pĂ©riodes oĂč il nây avait pas de brĂ»lage Ă la torche, et de plus grands pourcentages de cibles radar et de troupeaux dâoiseaux affichaient un comportement de vol non rectiligne (erratique et indirect) pendant la pĂ©riode oĂč il y a eu brĂ»lage Ă la torche. La nuit du brĂ»lage Ă la torche, la vive illumination nâa semblĂ© avoir un effet quâaprĂšs le coucher du soleil, quand les troupeaux dâoiseaux encerclaient lâĂźle aprĂšs avoir Ă©tĂ© attirĂ©s depuis un endroit qui semblait trĂšs lointain. Tant pour lâĂ©chantillonnage prĂ©levĂ© par radar que par consignation visuelle, le nombre de troupeaux dâoiseaux sâapprochant de lâĂźle diminuait dans le courant de la soirĂ©e, et lâattrait de la lumiĂšre Ă©manant du brĂ»lage Ă la torche semblait Ă©galement diminuer. La visibilitĂ© de la lune semblait avoir peu dâeffet sur le comportement des oiseaux. Puisque lâillumination provenant du brĂ»lage prolongĂ© Ă la torche exerce une si grande force dâattraction chez les oiseaux migrateurs, et puisque la plupart des troupeaux dâoiseaux volent en basse altitude au-dessus de lâeau, le torchage effectuĂ© sur les plateformes pĂ©troliĂšres cĂŽtiĂšres et extracĂŽtiĂšres dans lâAlaska de lâArctique devrait ĂȘtre positionnĂ© plus haut que les altitudes moyennes de vol des oiseaux migrateurs afin de rĂ©duire les risques dâincinĂ©ration
Effects of a Hazing-Light System on Migration and Collision Avoidance of Eiders at an Artificial Oil-Production Island, Arctic Alaska
During migration, Common and King Eiders (Somateria mollissima and S. spectabilis) cross the Beaufort and Chukchi Seas of Arctic Alaska. Because they may become attracted to lights, eiders are susceptible to collision with structures, including offshore oil facilities. We used ornithological radar in 2001 â 04 to characterize the behavior of eiders migrating past Northstar Island, an oil-production island near Prudhoe Bay, Alaska, and to assess the effects of a hazing-light system on migrating eiders. âEiderâ radar targets exhibited pulsed, irregular periods of movement; movement rates were higher when sea ice was present, without precipitation, and during tailwinds and crosswinds but were not affected by lights. Velocities (ground speeds) were higher when ice was present and with strong tailwinds. They were lower at night when the lights were on, but higher during the day when the lights were on. Radar targets exhibited little variation in flight behavior as they passed the island; the proportion of non-directional behavior was larger when ice was present, with tailwinds, with weak winds, and near the full moon when it was not visible. Lights had no effect on flight behavior. Birds tended to exhibit more course changes as they approached the island, greater angular changes when they changed course, and larger net increases in passing distance as a result of those course changes when the lights were on; however, none of these differences were statistically significant. Overall, the hazing lights at Northstar did not disrupt the birdsâ migratory movements but resulted in increased avoidance of the island.En pĂ©riode de migration, lâeider Ă duvet et lâeider Ă tĂȘte grise (Somateria mollissima et S. spectabilis) survolent la mer de Beaufort et la mer des Tchouktches dans lâAlaska de lâArctique. Comme ils sont attirĂ©s par les lumiĂšres, les eiders risquent dâentrer en collision avec des structures, y compris les installations pĂ©troliĂšres au large. De 2001 Ă 2004, nous avons utilisĂ© un radar ornithologique pour caractĂ©riser le comportement des eiders qui migrent au-delĂ de lâĂźle Northstar, une Ăźle de production pĂ©troliĂšre prĂšs de Prudhoe Bay, en Alaska, et pour Ă©valuer les effets dâun systĂšme dâĂ©clairage de dispersion sur les eiders en migration. Les « eiders » ciblĂ©s par le radar prĂ©sentaient des pĂ©riodes de mouvement pulsĂ©es et irrĂ©guliĂšres; les taux de mouvement Ă©taient plus importants en prĂ©sence de glace marine, en lâabsence de prĂ©cipitation et en prĂ©sence de vent arriĂšre et de vent latĂ©ral, mais nâĂ©taient pas touchĂ©s par les lumiĂšres. Les vĂ©locitĂ©s (vitesses au sol) Ă©taient plus Ă©levĂ©es en prĂ©sence de glace et de forts vents arriĂšre. Elles Ă©taient plus basses la nuit lorsque les lumiĂšres Ă©taient allumĂ©es, mais plus Ă©levĂ©es le jour lorsque les lumiĂšres Ă©taient allumĂ©es. Nous avons observĂ© peu de variation quant au comportement de vol des cibles atteintes par le radar pendant quâelles survolaient lâĂźle; la proportion de comportements de vol non directionnels Ă©tait plus importante en prĂ©sence de glace, de vent arriĂšre, de vent faible et lorsque la pleine lune nâĂ©tait pas visible. Les lumiĂšres nâont pas eu dâimpact sur le comportement de vol. Lorsque les lumiĂšres Ă©taient allumĂ©es, les oiseaux avaient tendance Ă changer de direction plus souvent durant leur vol Ă lâapproche de lâĂźle et Ă effectuer de plus grandes variations angulaires lorsquâils changeaient de direction, puis prĂ©sentaient une nette augmentation de la distance de passage Ă la suite de ces changements de direction. Toutefois, aucune de ces diffĂ©rences nâĂ©tait statistiquement importante. En gĂ©nĂ©ral, les lumiĂšres de dispersion de lâĂźle Northstar nâont pas nui aux mouvements migratoires des oiseaux, mais ces derniers ont davantage Ă©vitĂ© de voler prĂšs de lâĂźle
Human aquaporins: regulators of transcellular water flow
Background: Emerging evidence supports the view that (AQP) aquaporin water channels are regulators of transcellular
water flow. Consistentwith their expression in most tissues, AQPs are associatedwith diverse physiological
and pathophysiological processes.
Scope of review: AQP knockout studies suggest that the regulatory role of AQPs, rather than their action as passive
channels, is their critical function. Transport through all AQPs occurs by a common passive mechanism, but their
regulation and cellular distribution varies significantly depending on cell and tissue type; the role of AQPs in cell
volumeregulation (CVR) is particularly notable. This reviewexamines the regulatory role of AQPs in transcellular
water flow, especially in CVR.We focus on key systems of the human body, encompassing processes as diverse as
urine concentration in the kidney to clearance of brain oedema.
Major conclusions: AQPs are crucial for the regulation of water homeostasis, providing selective pores for the
rapidmovement ofwater across diverse cellmembranes and playing regulatory roles in CVR. Gatingmechanisms
have been proposed for human AQPs, but have only been reported for plant andmicrobial AQPs. Consequently, it
is likely that the distribution and abundance of AQPs in a particular membrane is the determinant of membrane
water permeability and a regulator of transcellular water flow.
General significance: Elucidating the mechanisms that regulate transcellular water flow will improve our understanding
of the human body in health and disease. The central role of specific AQPs in regulating water homeostasis
will provide routes to a range of novel therapies. This article is part of a Special Issue entitled Aquaporins
Rationalization of the color properties of fluorescein in the solid state: a combined computational and experimental study
Fluorescein is known to exist in three tautomeric forms defined as quinoid, zwitterionic and lactoid. In the solid state, the quinoid and zwitterionic forms give rise to red and yellow materials respectively. The lactoid form has not been crystallized pure, although its cocrystal and solvate forms exhibit colors ranging from yellow to green. An explanation for the observed colors of the crystals is found using a combination of UV/Vis spectroscopy and plane-wave DFT calculations. In addition, the role of cocrystal coformers in modifying crystal color is established. Several new crystal structures are determined using a combination of X-ray and electron diffraction, solid-state NMR and crystal structure prediction (CSP). The protocol presented herein may be used to predict color properties of materials prior to their synthesis.M.A. thanks EPSRC for a PhD studentship. M.D.E. acknowledges support from the Interreg V â2 Mers Seas ZeeĂ«nâ cross-border cooperation program. D.G.R. acknowledges financial support from the MRC. D.K.B. acknowledges University College London for an UCL Excellence Fellowship. A.J.M. acknowledges the support from the Winton Program for the Physics of Sustainability. G.M.D. thanks the Royal Society for funding. This work was performed using the Darwin Supercomputer of the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk/), provided by Dell Inc. using Strategic Research Infrastructure Funding from the Higher Education Funding Council for England and funding from the Science and Technology Facilities Council.This is the final version of the article. It first appeared from Wiley via https://doi.org/ 10.1002/chem.20160134
Spatial Transcriptomics. Digital Pathology to Investigate Intratumor Heterogeneity in Breast Cancer.
Non-randomised feasibility study testing a primary care intervention to promote engagement in an online health community for adults with troublesome asthma: protocol
Introduction: In the UK, approximately 4.3 million adults have asthma, with one-third experiencing poor asthma control, affecting their quality of life, and increasing their healthcare use. Interventions promoting emotional/behavioural self-management can improve asthma control and reduce comorbidities and mortality. Integration of online peer support into primary care services to foster self-management is a novel strategy. We aim to co-design and evaluate an intervention for primary care clinicians to promote engagement with an asthma online health community (OHC). Our protocol describes a âsurvey leading to a trialâ design as part of a mixed-methods, non-randomised feasibility study to test the feasibility and acceptability of the intervention. Methods and analysis: Adults on the asthma registers of six London general practices (~3000 patients) will be invited to an online survey, via text messages. The survey will collect data on attitudes towards seeking online peer support, asthma control, anxiety, depression, quality of life, information on the network of people providing support with asthma and demographics. Regression analyses of the survey data will identify correlates/predictors of attitudes/receptiveness towards online peer support. Patients with troublesome asthma, who (in the survey) expressed interest in online peer support, will be invited to receive the intervention, aiming to reach a recruitment target of 50 patients. Intervention will involve a one-off, face-to-face consultation with a practice clinician to introduce online peer support, sign patients up to an established asthma OHC, and encourage OHC engagement. Outcome measures will be collected at baseline and 3 months post intervention and analysed with primary care and OHC engagement data. Recruitment, intervention uptake, retention, collection of outcomes, and OHC engagement will be assessed. Interviews with clinicians and patients will explore experiences of the intervention. Ethics and dissemination: Ethical approval was obtained from a National Health Service Research Ethics Committee (reference: 22/NE/0182). Written consent will be obtained before intervention receipt and interview participation. Findings will be shared via dissemination to general practices, conference presentations and peer-reviewed publications. Trial registration number: NCT05829265
The principle of situated practice in literacy learning: studentsâ perspectives
O artigo resulta de uma investigação realizada no Ăąmbito de uma iniciativa governamental destinada a melhorar os nĂveis de literacia nas sĂ©ries iniciais do ensino fundamental em Portugal. A investigadora estudou as representaçÔes dos alunos sobre essa experiĂȘncia por meio da realização de entrevistas em grupo. Este artigo analisa os dados referentes Ă s representaçÔes dos alunos sobre uma das dimensĂ”es pedagĂłgicas centrais da aprendizagem da literacia, nomeadamente a constituĂda pela prĂĄtica situada. A anĂĄlise qualitativa revela representaçÔes muito positivas sobre a prĂĄtica que situou a aprendizagem, tendo os alunos expressado opiniĂ”es e sentimentos extremamente favorĂĄveis sobre a prĂĄtica de aprendizagem de literacia que experimentaram. A anĂĄlise dos dados desvelou ainda que o contexto que situou a aprendizagem foi ativo, lĂșdico, colaborativo e mediado pelas TIC. Esses resultados fundamentam, do ponto de vista Ășnico dos prĂłprios aprendentes, uma redefinição do entendimento atual do princĂpio da prĂĄtica situada da literacia nas sĂ©ries iniciais do ensino fundamental, no sentido do reconhecimento da centralidade da ludicidade nessa aprendizagem.This article derives from research developed in the context
of the implementation of a governmental initiative aimed to
enhance literacy learning in primary education in Portugal.
The researcher studied studentsâ representations about
their learning experience through group interviews. This
article focuses on data concerning studentsâ representations
about one of the central pedagogical dimensions of literacy
learning, namely situated practice. Qualitative analysis
revealed studentsâ very positive representations about the
practice which situated their learning, as they expressed
extremely favourable opinions and feelings. Data analysis
further unveiled that the context of learning was active,
playful, collaborative, and mediated by ICT. Such results
provide foundations for a theoretical redefinition of current
conceptions of situated practice by evidencing the centrality
of playfulness as learning practice in the education of the first
grades of primary education. This is an original contribution
made from the perspectives of learners themselves(undefined)info:eu-repo/semantics/publishedVersio
Identification and molecular mechanisms of the rapid tonicity-induced relocalization of the aquaporin 4 channel
The aquaporin family of integral membrane proteins is comprised of channels that mediate cellular water flow. Aquaporin 4 (AQP4) is highly expressed in the glial cells of the central nervous system and facilitates the osmotically-driven pathological brain swelling associated with stroke and traumatic brain injury. Here we show that AQP4 cell surface expression can be rapidly and reversibly regulated in response to changes of tonicity in primary cortical rat astrocytes and in transfected HEK293 cells. The translocation mechanism involves protein kinase A (PKA) activation, influx of extracellular calcium and activation of calmodulin. We identify five putative PKA phosphorylation sites and use site-directed mutagenesis to show that only phosphorylation at one of these sites, serine- 276, is necessary for the translocation response. We discuss our findings in the context of the identification of new therapeutic approaches to treating brain oedema
Children's Health in London and Luton (CHILL) cohort:a 12-month natural experimental study of the effects of the Ultra Low Emission Zone on children's travel to school
BACKGROUND: The Ultra-Low Emission Zone (ULEZ), introduced in Central London in April 2019, aims to enhance air quality and improve public health. The Children's Health in London and Luton (CHILL) study evaluates the impact of the ULEZ on children's health. This analysis focuses on the one-year impacts on the shift towards active travel to school.METHODS: CHILL is a prospective parallel cohort study of ethnically diverse children, aged 6-9 years attending 84 primary schools within or with catchment areas encompassing London's ULEZ (intervention) and Luton (non-intervention area). Baseline (2018/19) and one-year follow-up (2019/20) data were collected at school visits from 1992 (58%) children who reported their mode of travel to school 'today' (day of assessment). Multilevel logistic regressions were performed to analyse associations between the introduction of the ULEZ and the likelihood of switching from inactive to active travel modes, and vice-versa. Interactions between intervention group status and pre-specified effect modifiers were also explored.RESULTS: Among children who took inactive modes at baseline, 42% of children in London and 20% of children in Luton switched to active modes. For children taking active modes at baseline, 5% of children in London and 21% of children in Luton switched to inactive modes. Relative to the children in Luton, children in London were more likely to have switched from inactive to active modes (OR 3.64, 95% CI 1.21-10.92). Children in the intervention group were also less likely to switch from active to inactive modes (OR 0.11, 0.05-0.24). Moderator analyses showed that children living further from school were more likely to switch from inactive to active modes (OR 6.06,1.87-19.68) compared to those living closer (OR 1.43, 0.27-7.54).CONCLUSIONS: Implementation of clean air zones can increase uptake of active travel to school and was particularly associated with more sustainable and active travel in children living further from school.</p
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