1,355 research outputs found
Arctic HYCOS – 1st Workshop on Improved Monitoring, Accuracy and Data Availability in the Arctic Drainage Basin: Meeting Summary Report and Implementation Plan
The World Hydrological Cycle Observing System (WHYCOS) is a global programme, developed in response to the scarcity or absence of accurate, timely and accessible data and information in real or near real time on freshwater resources in many parts of the world. The programme is implemented through various components (HYCOSs) at the regional and/or basin scale. It is guided by the WHYCOS International Advisory Group (WIAG). The Arctic-HYCOS program is being promoted through this Workshop. For more information on the WHYCOS, please see http://www.whycos.org/cms/.
The main goal of the Arctic-HYCOS program is to improve monitoring, data accuracy, availability and dissemination of information in the pan-arctic drainage basin. This project is science-driven and is aimed at monitoring freshwater fluxes and pollutants into the Arctic Ocean with the objective of improving climate predictions in the Northern Hemisphere and assessing the pollution of the Arctic coastal areas and the open Arctic Ocean. Arctic-HYCOS is currently organized along three main activities.
1. Develop and optimal design fro hydro-meteorological monitoring networks to capture the essential variability of the Arctic hydrological system and to enable accurate and efficient assessment of change
2. Estimate uncertainty of available in situ and possible remote sensing data including analysis of accuracy and systematic errors of new observation technology
3. Develop an integrated pan-arctic data consolidation and analysis system for the water cycle uniting data from various in-situ and other sources
Bone and metal - an orthopaedic perspective on osseointegration of metals
The area of implant osseointegration is of major importance, given the predicted significant rise in the number of orthopaedic procedures and an increasingly ageing population. Osseointegration is a complex process involving a number of distinct mechanisms affected by the implant bulk properties and surface characteristics. Our understanding and ability to modify these mechanisms through alterations in implant design is continuously expanding. The following review considers the main aspects of material and surface alterations in metal implants, and the extent of their subsequent influence on osseointegration. Clinically, osseointegration results in asymptomatic stable durable fixation of orthopaedic implants. The complexity of achieving this outcome through incorporation and balance of contributory factors is highlighted through a clinical case report
Low cost, SPF aluminum cryogenic tank structure for ALS
Past production work has shown that cryogenic tank structure for the Shuttle Booster Rockets and the Titan system have very high life cycle costs for the fuel tank structure. The tanks are machined stiffener-skin combination that are subsequently formed into the required contour after machining. The material scrap rate for these configurations are usually high, and the loss of a tank panel due to forming or heat treatment problems is very costly. The idea of reducing the amount of scrap material and scrapped structural members has prompted the introduction of built-up structure for cryogenic tanks to be explored on the ALS program. A build-up structure approach that has shown improvements in life cycle cost over the conventional built-up approach is the use of superplastically formed (SPF) stiffened panels (reducing the overall part count and weight for the tank) resistance spot welded (RSW) to outer tank skin material. The stiffeners provide for general stability of the tank, while the skin material provides hoop direction continuity for the loads
Le contact forêt-savane en moyenne Côte d'Ivoire
Forest-savanna boundary in middle Ivory Coast.
An investigation concerning geomorphology-soils-vegetation relations has been undertaken in order to determine correlations between distribution of vegetable formations and environmental factors, while in the same time human investigations were trying to define man's relationship with natural environment.
Various observations seem to prove that distribution of Forest-Savanna mosaic, in the zone of study, resulted mainly from the preponderance of geomorphological evolution and accordingly of the soils which are deriving from it, over the distribution of vegetable formations. On the other hand, the present progression of forest, which has been observed in many points in spite of influence of bush fire, is partly dependent on the substratum : unfavourable edaphic characters of savanna soils are putting off dynamism.Une étude des relations géomorphologie-sol-végétation a été entreprise dans le dessein de déterminer les corrélations qui peuvent exister entre la répartition des formations végétales et les facteurs du milieu, tandis que dans le même temps des études humaines ont tenté de définir les rapports de l'homme avec le milieu naturel.
Les diverses observations semblent montrer que la distribution en mosaïque forêt-savane, dans la zone étudiée, provient de la prépondérance de l'évolution géomorphologique, et par conséquent des sols en dérivant, sur la répartition des formations végétales. D'autre part, l'avancée actuelle de la forêt, constatée en de nombreux points malgré l'influence des feux de brousse, est en partie dépendante du substratum : le dynamisme est retardé par les caractères édaphiques défavorables des sols de savane.Avenard Jean-Michel, Bonvallot Jacques, Latham Marc, Renard-Dugerdil Marianne, Richard Jacques. Le contact forêt-savane en moyenne Côte-d'Ivoire. In: Annales de Géographie, t. 82, n°453, 1973. pp. 513-544
A Photometric Survey for Variables and Transits in the Field of Praesepe with KELT
The Kilodegree Extremely Little Telescope (KELT) project is a small aperture,
wide-angle search for planetary transits of solar-type stars. In this paper, we
present the results of a commissioning campaign with the KELT telescope to
observe the open cluster Praesepe for 34 nights in early 2005. Lightcurves were
obtained for 69,337 stars, out of which we identify 58 long period variables
and 152 periodic variables. Sixteen of these are previously known as variable,
yielding 194 newly discovered variable stars for which we provide properties
and lightcurves. We also searched for planetary-like transits, finding four
transit candidates. Follow-up observations indicate that two of the candidates
are astrophysical false positives, with two candidates remaining as potential
planetary transits.Comment: 45 pages, 16 figures. Submitted to AJ. PDF version with full
resolution figures located at
http://www.astronomy.ohio-state.edu/~pepper/kelt.pd
Sustainable Driven Grouse Shooting? A summary of the evidence
Driven grouse shooting is not a stand-alone activity. It exists as part of a complex system of integrated moorland management that delivers ecological, economic, and social impacts. The critical questions are whether these impacts deliver benefits to society and the environment, and whether alternative uses of the UK’s moorlands would deliver greater benefits. This review of the extant literature in this area seeks to explore the economic, social and environmental impacts of driven grouse shooting, in order to understand its role in the economy, communities and managing moorland areas
Examining the role of driven-game shooting as a psycho-social resource for older adults in rural areas: a mixed-methods study
This paper explores whether regular involvement in a rural, country sport, frequently practiced by older individuals, builds social capital and friendships, reduces loneliness and positively impacts individuals’ health and well-being. Taking a critical realist, mixed-methods approach, using a recognised social impact assessment methodology theoretically underpinned by social capital theory, this study identifies that driven game shooting (DGS) participation creates social impact via social capital creation and identity reinforcement. Results indicate a statistically significant, positive impact on mental health and well-being (n=2424), which varies by shoot size and/or type. The results are discussed in relation to implications for managing elderly health and wellbeing in rural areas
Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit
We report the discovery and initial characterization of Qatar-2b, a hot
Jupiter transiting a V = 13.3 mag K dwarf in a circular orbit with a short
period, P_ b = 1.34 days. The mass and radius of Qatar-2b are M_p = 2.49 M_j
and R_p = 1.14 R_j, respectively. Radial-velocity monitoring of Qatar-2 over a
span of 153 days revealed the presence of a second companion in an outer orbit.
The Systemic Console yielded plausible orbits for the outer companion, with
periods on the order of a year and a companion mass of at least several M_j.
Thus Qatar-2 joins the short but growing list of systems with a transiting hot
Jupiter and an outer companion with a much longer period. This system
architecture is in sharp contrast to that found by Kepler for multi-transiting
systems, which are dominated by objects smaller than Neptune, usually with
tightly spaced orbits that must be nearly coplanar
Regulation of two motor patterns enables the gradual adjustment of locomotion strategy in Caenorhabditis elegans
In animal locomotion a tradeoff exists between stereotypy and flexibility: fast long-distance travelling (LDT) requires coherent regular motions, while local sampling and area-restricted search (ARS) rely on flexible movements. We report here on a posture control system in C. elegans that coordinates these needs. Using quantitative posture analysis we explain worm locomotion as a composite of two modes: regular undulations versus flexible turning. Graded reciprocal regulation of both modes allows animals to flexibly adapt their locomotion strategy under sensory stimulation along a spectrum ranging from LDT to ARS. Using genetics and functional imaging of neural activity we characterize the counteracting interneurons AVK and DVA that utilize FLP-1 and NLP-12 neuropeptides to control both motor modes. Gradual regulation of behaviors via this system is required for spatial navigation during chemotaxis. This work shows how a nervous system controls simple elementary features of posture to generate complex movements for goal-directed locomotion strategies
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