566 research outputs found
Real-time flood inundation forecasting and mapping for key railway infrastructure: a UK case study
Flooding events that impede railway infrastructure can cause severe travel delays for the general public and large fines in delayed minutes for the rail industry. Early warnings of flood inundation can give more time to implement mitigation measures which help reduce cancellations, delays and fines. Initial work is reported on the development of a real-time flood inundation forecasting and mapping system for the Cowley Bridge track area near Exeter, UK. This location is on one of the main access routes to South West England and has suffered major floods in the past resulting in significant transport impacts. Flood forecasting systems in the UK mainly forecast river level/flow rather than extent and depth of flood inundation. Here, the development of a chain of coupled models is discussed that link rainfall to river flow, river level and flood extent for the rail track area relating to Cowley Bridge. Historical events are identified to test model performance in predicting inundation of railway infrastructure. The modelling system will operate alongside a series of in-situ sensors chosen to enhance the flood mapping forecasting system. Sensor data will support offline model calibration/verification and real-time data assimilation as well as monitoring flood conditions to inform track closure decisions
LunaNet: a Flexible and Extensible Lunar Exploration Communications and Navigation Infrastructure
NASA has set the ambitious goal of establishing a sustainable human presence on the Moon. Diverse commercial and international partners are engaged in this effort to catalyze scientific discovery, lunar resource utilization and economic development on both the Earth and at the Moon. Lunar development will serve as a critical proving ground for deeper exploration into the solar system. Space communications and navigation infrastructure will play an integral part in realizing this goal. This paper provides a high-level description of an extensible and scalable lunar communications and navigation architecture, known as LunaNet. LunaNet is a services network to enable lunar operations. Three LunaNet service types are defined: networking services, position, navigation and timing services, and science utilization services. The LunaNet architecture encompasses a wide variety of topology implementations, including surface and orbiting provider nodes. In this paper several systems engineering considerations within the service architecture are highlighted. Additionally, several alternative LunaNet instantiations are presented. Extensibility of the LunaNet architecture to the solar system internet is discussed
Distribution and Community Characteristics of Staging Shorebirds on the Northern Coast of Alaska
Avian studies conducted in the 1970s on Alaskaâs Arctic Coastal Plain (ACP) indicated that coastal littoral habitats are important to Arctic-breeding shorebirds for staging prior to fall migration. However, relatively little recent, broad-scale, or quantitative information exists on shorebird use of staging areas in this region. To locate possible shorebird concentration areas in the littoral zone of the ACP, we conducted aerial surveys from the southwest end of Kasegaluk Lagoon on the Chukchi Sea to Demarcation Point on the Beaufort Sea during the summers of 2005â07. These surveys identified persistent within- and between-year concentrations of staging shorebirds at Peard Bay, Point Barrow/Elson Lagoon, Cape Simpson, and Smith Bay to Cape Halkett. Among river deltas in the Beaufort Sea, the Sagavanirktok and Kongakut deltas had large concentrations of staging shorebirds. We also collected data on shorebird community characteristics, staging phenology, and habitat use in 2005 and 2006 by conducting land-based surveys at six camps: Kasegaluk Lagoon, Peard Bay, Point Barrow/Elson Lagoon, Colville Delta, Sagavanirktok Delta, and Okpilak Delta. The shorebird community was more even and diverse (evenness E and Shannon Weiner Hâ) along the Beaufort Sea compared to the Chukchi Sea and in 2005 versus 2006. Staging phenology varied by species and location and differed for several species from that reported in previous studies. Our results suggest the existence of three foraging habitat guilds among the shorebird species observed in this study: gravel beach, mudflat, and salt marsh/pond edge. A comparison to data collected in the mid-1970s suggests that these foraging associations are conserved through time. Results from this research will be useful to land managers for monitoring the effects of changing environmental conditions and human activity on shorebirds and their habitats in Arctic Alaska.Des Ă©tudes aviaires rĂ©alisĂ©es dans les annĂ©es 1970 sur la plaine cĂŽtiĂšre de lâArctique en Alaska ont permis de constater que les habitats du littoral cĂŽtier revĂȘtent de lâimportance pour les oiseaux de rivage nicheurs de lâArctique en halte migratoire avant la migration dâautomne. Cependant, relativement peu dâinformation rĂ©cente, Ă grande Ă©chelle ou quantitative existe Ă propos de lâutilisation que font les oiseaux de rivage des haltes migratoires de cette rĂ©gion. Afin de localiser des zones de concentration possibles dâoiseaux de rivage dans la rĂ©gion littorale de la plaine cĂŽtiĂšre de lâArctique, nous avons effectuĂ© des levĂ©s aĂ©riens du sud-ouest de la lagune Kasegaluk dans la mer des Tchouktches jusquâĂ Demarcation Point dans la mer de Beaufort au cours des Ă©tĂ©s allant de 2005 Ă 2007. Ces levĂ©s ont permis de repĂ©rer des concentrations durables dâoiseaux de rivage en halte migratoire au cours dâune mĂȘme annĂ©e ainsi que dâune annĂ©e Ă lâautre Ă la baie Peard, Ă pointe Barrow et Ă la lagune Elson, au cap Simpson de mĂȘme que de la baie Smith jusquâau cap Halkett. Parmi les deltas de riviĂšres de la mer de Beaufort, les deltas Sagavanirktok et Kongakut comptaient de fortes concentrations dâoiseaux de rivage en halte migratoire. Nous avons Ă©galement recueilli des donnĂ©es sur les caractĂ©ristiques des populations dâoiseaux de rivage, sur la phĂ©nologie des haltes migratoires de mĂȘme que sur lâutilisation des habitats en 2005 et en 2006 au moyen de levĂ©s terrestres effectuĂ©s Ă six camps, soit celui de la lagune Kasegaluk, de la baie Peard, de la pointe Barrow et de la lagune Elson, du delta Colville, du delta Sagavanirktok et du delta Okpilak. La population dâoiseaux de rivage Ă©tait plus homogĂšne et diverse (homogĂ©nĂ©itĂ© E et Shannon Weiner Hâ) le long de la mer de Beaufort comparativement Ă la mer des Tchouktches, ainsi quâen 2005 par rapport Ă 2006. La phĂ©nologie en halte migratoire variait selon les espĂšces et les emplacements, et diffĂ©rait pour plusieurs espĂšces de celles signalĂ©es dans le cadre dâĂ©tudes ultĂ©rieures. Nos rĂ©sultats laissent croire Ă lâexistence de trois guildes dâhabitats de fourrage chez les espĂšces dâoiseaux de rivage observĂ©es dans cette Ă©tude : plage de gravier, vasiĂšre et marais salant ou bordure dâĂ©tang. La comparaison des donnĂ©es recueillies au milieu des annĂ©es 1970 laisse entendre que ces associations de fourrage se sont conservĂ©es au fil du temps. Les rĂ©sultats dĂ©coulant de cette recherche seront utiles aux gestionnaires de terres dans le cadre de la surveillance des effets des conditions environnementales changeantes et de lâactivitĂ© humaine sur les oiseaux de rivage et leurs habitats de lâArctique alaskien
Genetic Factors and Orofacial Motor Learning Selectively Influence Variability in Central Sulcus Morphology in Chimpanzees (Pan troglodytes)
International audienceCaptive chimpanzees (Pan troglodytes) have been shown to learn the use of novel attention-getting (AG) sounds to capture the attention of humans as a means of requesting or drawing their attention to a desired object or food. There are significant individual differences in the use of AG sounds by chimpanzees and, here, we examined whether changes in cortical organization of the central sulcus (CS) were associated with AG sound production. MRI scans were collected from 240 chimpanzees, including 122 that reliably produced AG sounds and 118 that did not. For each subject, the depth of CS was quantified along the superior-inferior plane with specific interest in the inferior portion corresponding to the region of the motor cortex where the mouth and orofacial movements are controlled. Results indicated that CS depth in the inferior, but not superior, portion was significantly greater in chimpanzees that reliably produced AG sounds compared with those who did not. Quantitative genetic analyses indicated that overall CS surface area and depth were significantly heritable, particularly in the superior regions, but less so in the inferior and central portions. Further, heritability in CS depth was altered as a function of acquisition of AG sounds. The collective results suggest that learning to produce AG sounds resulted in region-specific cortical reorganization within the inferior portion of the CS, a finding previously undocumented in chimpanzees or any nonhuman primate
Distribution of Breeding Shorebirds on the Arctic Coastal Plain of Alaska
Available information on the distribution of breeding shorebirds across the Arctic Coastal Plain of Alaska is dated, fragmented, and limited in scope. Herein, we describe the distribution of 19 shorebird species from data gathered at 407 study plots between 1998 and 2004. This information was collected using a single-visit rapid area search technique during territory establishment and early incubation periods, a time when social displays and vocalizations make the birds highly detectable. We describe the presence or absence of each species, as well as overall numbers of species, providing a regional perspective on shorebird distribution. We compare and contrast our shorebird distribution maps to those of prior studies and describe prominent patterns of shorebird distribution. Our examination of how shorebird distribution and numbers of species varied both latitudinally and longitudinally across the Arctic Coastal Plain of Alaska indicated that most shorebird species occur more frequently in the Beaufort Coastal Plain ecoregion (i.e., closer to the coast) than in the Brooks Foothills ecoregion (i.e., farther inland). Furthermore, the occurrence of several species indicated substantial longitudinal directionality. Species richness at surveyed sites was highest in the western portion of the Beaufort Coastal Plain ecoregion. The broad-scale distribution information we present here is valuable for evaluating potential effects of human development and climate change on Arctic-breeding shorebird populations.Les renseignements qui existent en matiĂšre de rĂ©partition des oiseaux de rivage en reproduction sur la plaine cĂŽtiĂšre de lâArctique en Alaska sont anciens, fragmentĂ©s et restreints. Ici, nous dĂ©crivons la rĂ©partition de 19 espĂšces dâoiseaux de rivage Ă partir de donnĂ©es recueillies Ă 407 lieux de recherche entre 1998 et 2004. Cette information a Ă©tĂ© recueillie grĂące Ă une technique de recherche consistant en une seule visite rapide durant les pĂ©riodes dâĂ©tablissement du territoire et de dĂ©but dâincubation, pĂ©riodes pendant lesquelles les comportements sociaux et les vocalisations permettent de bien repĂ©rer les oiseaux. Nous dĂ©crivons la prĂ©sence ou lâabsence de chaque espĂšce, de mĂȘme que le nombre gĂ©nĂ©ral dâespĂšces, ce qui procure une perspective rĂ©gionale de la rĂ©partition des oiseaux de rivage. Nous comparons et contrastons nos cartes de rĂ©partition des oiseaux de rivage Ă celles dâĂ©tudes antĂ©rieures, en plus de dĂ©crire les tendances les plus marquĂ©es en matiĂšre de rĂ©partition des oiseaux de rivage. Notre examen de la variation latitudinale et longitudinale en matiĂšre de rĂ©partition et de nombre dâespĂšces dâoiseaux de rivage Ă lâĂ©chelle de la plaine cĂŽtiĂšre arctique de lâAlaska nous a permis de constater que la plupart des espĂšces dâoiseaux de rivage se manifestaient plus souvent dans la rĂ©gion Ă©cologique de la plaine cĂŽtiĂšre de Beaufort (câest-Ă -dire plus proche de la cĂŽte) que dans la rĂ©gion Ă©cologique des contreforts de Brooks (câest-Ă -dire plus Ă lâintĂ©rieur des terres). Par ailleurs, lâoccurrence de plusieurs espĂšces indiquait une directionalitĂ© longitudinale substantielle. La richesse des espĂšces aux sites Ă lâĂ©tude Ă©tait Ă son meilleur dans la partie ouest de la rĂ©gion Ă©cologique de la plaine cĂŽtiĂšre de Beaufort. Les renseignements sur la rĂ©partition Ă grande Ă©chelle que nous prĂ©sentons ici jouent un rĂŽle dans lâĂ©valuation des effets Ă©ventuels des travaux de mise en valeur par lâĂȘtre humain et du changement climatique sur les populations dâoiseaux de rivage en reproduction de lâArctique
Marine geophysical investigation of the chain fracture zone in the equatorial Atlantic From the PIâLAB experiment
The Chain Fracture Zone is a 300âkmâlong transform fault that offsets the MidâAtlantic Ridge. We analyzed new multibeam bathymetry, backscatter, gravity, and magnetic data with 100% multibeam bathymetric data over the active transform valley and adjacent spreading segments as part of the Passive Imaging of the Lithosphere Asthenosphere Boundary (PIâLAB) Experiment. Analyses of these data sets allow us to determine the history and mode of crustal formation and the tectonic evolution of the transform system and adjacent ridges over the past 20 Myr. We model the total field magnetic anomaly to determine the age of the crust along the northern ridge segment to better establish the timing of the variations in the seafloor fabric and the tectonicâmagmatic history of the region. Within the active transform fault zone, we observe four distinct positive flower structures with several en Ă©chelon fault scarps visible in the backscatter data. We find up to â10 mGal residual Mantle Bouguer Anomaly in the region of the largest positive flower structure within the transform zone suggesting crustal thickening relative to the crustal thinning typically observed in fracture zones in the Atlantic. The extensional/compressional features observed in the Chain Transform are less pronounced than those observed further north in the Vema, St. Paul, and Romanche and may be due to local ridge segment adjustments
Community Health and Socioeconomic Issues Surrounding Concentrated Animal Feeding Operations
A consensus of the Workgroup on Community and Socioeconomic Issues was that improving and sustaining healthy rural communities depends on integrating socioeconomic development and environmental protection. The workgroup agreed that the World Health Organizationâs definition of health, âa state of complete physical, mental and social well-being and not merely the absence of disease or infirmity,â applies to rural communities. These principles are embodied in the following main points agreed upon by this workgroup. Healthy rural communities ensure a) the physical and mental health of individuals, b) financial security for individuals and the greater community, c) social well-being, d ) social and environmental justice, and e) political equity and access. This workgroup evaluated impacts of the proliferation of concentrated animal feeding operations (CAFOs) on sustaining the health of rural communities. Recommended policy changes include a more stringent process for issuing permits for CAFOs, considering bonding for manure storage basins, limiting animal density per watershed, enhancing local control, and mandating environmental impact statements
Quantitative magnetic resonance imaging predicts individual future liver performance after liver resection for cancer
The risk of poor post-operative outcome and the benefits of surgical resection as a curative therapy require careful assessment by the clinical care team for patients with primary and secondary liver cancer. Advances in surgical techniques have improved patient outcomes but identifying which individual patients are at greatest risk of poor post-operative liver performance remains a challenge. Here we report results from a multicentre observational clinical trial (ClinicalTrials.gov NCT03213314) which aimed to inform personalised pre-operative risk assessment in liver cancer surgery by evaluating liver health using quantitative multiparametric magnetic resonance imaging (MRI). We combined estimation of future liver remnant (FLR) volume with corrected T1 (cT1) of the liver parenchyma as a representation of liver health in 143 patients prior to treatment. Patients with an elevated preoperative liver cT1, indicative of fibroinflammation, had a longer post-operative hospital stay compared to those with a cT1 within the normal range (6.5 vs 5 days; p = 0.0053). A composite score combining FLR and cT1 predicted poor liver performance in the 5 days immediately following surgery (AUROC = 0.78). Furthermore, this composite score correlated with the regenerative performance of the liver in the 3 months following resection. This study highlights the utility of quantitative MRI for identifying patients at increased risk of poor post-operative liver performance and a longer stay in hospital. This approach has the potential to inform the assessment of individualised patient risk as part of the clinical decision-making process for liver cancer surgery
Chronicles of hypoxia: Time-series buoy observations reveal annually recurring seasonal basin-wide hypoxia in Muskegon Lake â A Great Lakes estuary
We chronicled the seasonally recurring hypolimnetic hypoxia in Muskegon Lake â a Great Lakes estuary over 3 years, and examined its causes and consequences. Muskegon Lake is a mesotrophic drowned river mouth that drains Michigan\u27s 2nd largest watershed into Lake Michigan. A buoy observatory tracked ecosystem changes in the Muskegon Lake Area of Concern (AOC), gathering vital time-series data on the lake\u27s water quality from early summer through late fall from 2011 to 2013 (www.gvsu.edu/buoy). Observatory-based measurements of dissolved oxygen (DO) tracked the gradual development, intensification and breakdown of hypoxia (mild hypoxia b4 mg DO/L, and severe hypoxia b2 mg DO/L) below the ~6 m thermocline in the lake, occurring in synchrony with changes in temperature and phytoplankton biomass in the water column during JulyâOctober. Time-series data suggest that proximal causes of the observed seasonal hypolimnetic DO dynamics are stratified summer water-column, reduced wind-driven mixing, longer summer residence time, episodic intrusions of cold DO-rich nearshore Lake Michigan water, nutrient run off from watershed, and phytoplankton blooms. Additional basin-wide water-column profiling (2011â2012) and ship-based seasonal surveys (2003â2013) confirmed that bottom water hypoxia is an annually recurring lake-wide condition. Volumetric hypolimnetic oxygen demand was high (0.07â0.15 mg DO/Liter/day) and comparable to other temperate eutrophic lakes. Over 3 years of intense monitoring, ~9â24% of Muskegon Lake\u27s volume experienced hypoxia for ~29â85 days/year â with the potential for hypolimnetic habitat degradation and sediment phosphorus release leading to further eutrophication. Thus, time-series observatories can provide penetrating insights into the inner workings of ecosystems and their external drivers
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