967 resultados para United States. Office of Scientific Research and Development.


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The WorldFish Center was tasked to undertake a study to access, collate and develop background materials to produce an internationally linked and Africa-wide perspective on sectorally relevant policy issues. The specific objective of the study was to assess and define conditions and impact pathways, in Africa or elsewhere, where markets, policies, resources and technologies have combined to promote steady and sustainable growth of aquaculture, and where have been clear direct impacts on food supply, income, employment and consumption opportunities, as well as increase in supply that has led to stabilised prices. The study was also aimed at providing guidelines for scaling up the implementation of the synthesis study via Afri-FishNet (CAADP Fish Expert Pools) at the national and regional levels.

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This paper describes the design considerations for a proposed aerodynamic characterization facility (ACF) for micro aerial vehicles (MAVs). This is a collaborative effort between the Air Force Research Laboratory Munitions Directorate (AFRL/MN) and the University of Florida Research and Engineering Education Facility (UF/REEF). The ACF is expected to provide a capability for the characterization of the aerodynamic performance of future MAVs. This includes the ability to gather the data necessary to devise control strategies as well as the potential to investigate aerodynamic 'problem areas' or specific failings. Since it is likely that future MAVs will incorporate advanced control strategies, the facility must enable researchers to critically assess such novel methods. Furthermore, the aerodynamic issues should not be seen (and tested) in isolation, but rather the facility should be able to also provide information on structural responses (such as aeroelasticity) as well as integration issues (say, thrust integration or sensor integration). Therefore the mission for the proposed facility ranges form fairly basic investigations of individual technical issues encountered by MAVs (for example an evaluation of wing shapes or control effectiveness) all the way to testing a fully integrated vehicle in a flight configuration for performance evaluation throughout the mission envelope.

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The topic of this thesis is an acoustic scattering technique for detennining the compressibility and density of individual particles. The particles, which have diameters on the order of 10 µm, are modeled as fluid spheres. Ultrasonic tone bursts of 2 µsec duration and 30 MHz center frequency scatter from individual particles as they traverse the focal region of two confocally positioned transducers. One transducer acts as a receiver while the other both transmits and receives acoustic signals. The resulting scattered bursts are detected at 90° and at 180° (backscattered). Using either the long wavelength (Rayleigh) or the weak scatterer (Born) approximations, it is possible to detennine the compressibility and density of the particle provided we possess a priori knowledge of the particle size and the host properties. The detected scattered signals are digitized and stored in computer memory. With this information we can compute the mean compressibility and density averaged over a population of particles ( typically 1000 particles) or display histograms of scattered amplitude statistics. An experiment was run first run to assess the feasibility of using polystyrene polymer microspheres to calibrate the instrument. A second study was performed on the buffy coat harvested from whole human blood. Finally, chinese hamster ovary cells which were subject to hyperthermia treatment were studied in order to see if the instrument could detect heat induced membrane blebbing.

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Background: Assessing child growth and development is complex. Delayed identification of growth or developmental problems until school entry has health, educational and social consequences for children and families. Health care professionals (HCPs), including Public Health Nurses work with parents to elicit and attend to their growth and development concerns. It is known that parents have concerns about their children’s growth and development which are not expressed in a timely manner. Measuring parental concern has not been fully effective to date and little is known about parents’ experiences of expressing concerns. Aim: To understand how parents make sense of child growth or development concerns. Method: The study was qualitative using Interpretative Phenomenological Analysis (IPA). A purposeful sample of 15 parents of pre-school children referred by their PHN to second tier services was used. Data were collected by semi-structured interviews. NVivo version 10 was used for data management purposes and IPA for analysis. Findings: Findings yielded two contextual themes which captured how parents described The Concern – ‘telling it as it is’ and their experiences of being Referred on. Four superordinate themes were found which encapsulated the Uncertainty – ‘a little bit not sure’ of parents as they made sense of the child’s growth and development problems. They were influenced by Parental Knowledge – ‘being and getting in the know’ which aided their sense-making before being prompted by Triggers to action. Parents then described Getting the child’s problem checked out as they went to express their concerns to HCPs. Conclusion and Implications: Parental expression of concerns about their child is a complex process that may not be readily understood by HCPs. A key implication of findings is to reappraise how parental concern is elicited and attended to in order to promote early referral and intervention of children who may have growth and development problems.

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The Healthy and Biologically Diverse Seas Evidence Group (HBDSEG) has been tasked with providing the technical advice for the implementation of the Marine Strategy Framework Directive (MSFD) with respect to descriptors linked to biodiversity. A workshop was held in London to address one of the Research and Development (R&D) proposals entitled: ‘Mapping the extent and distribution of habitats using acoustic and remote techniques, relevant to indicators for area/extent/habitat loss.’ The aim of the workshop was to identify, define and assess the feasibility of potential indicators of benthic habitat distribution and extent, and identify the R&D work which could be required to fully develop these indicators. The main points that came out of the workshop were: (i) There are many technical aspects of marine habitat mapping that still need to be resolved if cost-effective spatial indicators are to be developed. Many of the technical aspects that need addressing surround issues of consistency, confidence and repeatability. These areas should be tackled by the JNCC Habitat Mapping and Classification Working Group and the HBDSEG Seabed Mapping Working Group. (ii) There is a need for benthic ecologists (through the HBDSEG Benthic Habitats Subgroup and the JNCC Marine Indicators Group) to finalise the list of habitats for which extent and/or distribution indicators should be considered for development, building upon the recommendations from this report. When reviewing the list of indicators, benthic habitats could also be distinguished into those habitats that are defined/determined primarily by physical parameters (although including biological assemblages) (e.g. subtidal shallow sand) and those defined primarily by their biological assemblage (e.g. seagrass beds). This distinction is important as some anthropogenic pressures may influence the biological component of the ecosystem despite not having a quantifiable effect on the physical habitat distribution/extent. (iii) The scale and variety of UK benthic habitats makes any attempt to undertake comprehensive direct mapping exercises prohibitively expensive (especially where there is a need for repeat surveys for assessment). There is a clear need therefore to develop a risk-based approach that uses indirect indicators (e.g. modelling), such as habitats at risk from pressures caused by current human activities, to develop priorities for information gathering. The next steps that came out of the workshop were: (i) A combined approach should be developed by the JNCC Marine Indicators Group together with the HBDSEG Benthic Habitats Subgroup, which will compile and ultimately synthesise all the criteria used by the three different groups from the workshop. The agreed combined approach will be used to undertake a final review of the habitats considered during the workshop, and to evaluate any remaining habitats in order to produce a list of habitats for indicator development for which extent and/or distribution indicators could be appropriate. (ii) The points of advice raised at this workshop, alongside the combined approach aforementioned, and the final list of habitats for extent and/or distribution indicator development will be used to develop a prioritised list of actions to inform the next round of R&D proposals for benthic habitat indicator development in 2014. This will be done through technical discussions within JNCC and the relevant HBDSEG Subgroups. The preparation of recommendations by these groups should take into account existing work programmes, and consider the limited resources available to undertake any further R&D work.

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There is growing evidence that climate change could affect marine benthic systems. This review provides information of climate change‐related impacts on the marine benthos in the North Atlantic. We cover a number of related research aspects, mainly in connection to two key issues. First, is the relationship between different physical aspects of climate change and the marine benthos. This section covers: (a) the responses to changes in seawater temperature (biogeographic shifts and phenology); (b) altered Hydrodynamics; (c) ocean acidification (OA); and (d) sea‐level rise‐coastal squeeze. The second major issue addressed is the possible integrated impact of climate change on the benthos. This work is based on relationships between proxies for climate variability, notably the North Atlantic Oscillation (NAO) index, and the long‐term marine benthos. The final section of our review provides a series of conclusions and future directions to support climate change research on marine benthic systems. WIREs Clim Change 2015, 6:203–223. doi: 10.1002/wcc.330

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The hypothesis that rapid y-aminobutyric acid (GABA) accumulation is a plant defense against phytophagous insects was investigated. Simulation of mechanical damage resulting from phytophagous insect activity increased soybean (Glycine max L.) leaf GABA 10- to 25-fold within 1 to 4 min. Pulverizing leaf tissue resulted in a value of 2. 15 (±O. 11 SE) ~mol GABA per gram fresh weight. Increasing the GABA levels in a synthetic diet from 1.6 to 2.6 Jlffiol GABA per gram fresh weight reduced the growth rates, developmental rates, total biomass (50% reduction), and survival rates (30% reduction) of cultured Oblique banded leaf-roller (OBLR) (Choristonellra rosacealla Harris) larvae. In field experiments OBLR larvae were found predominantly on young terminal leaves which have a reduced capacity to produce GABA in response to mechanical damage. Glutamate decarboxylase (GAD) is a cytosolic enzyme which catalyses the decarboxylation of L-Glu to GABA. GAD is a calmodulin binding enzyme whose activity is stimulated dramatically by increased cytosolic H+ or Ca2 + ion concentrations. Phytophagous insect activity will disrupt the cellular compartmentation of H+ and Ca2 +, activate GAD and subsequent GABA accumulation. In animals GABA is a major inhibitory neurotransmitter. The possible mechanisms resulting in GABA inhibited growth and development of insects are discussed.

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Clipping from a Town Council meeting at which estimates of the costs of Railway Line no. 1 and Line no. 2 were submitted by the office of Port Dalhousie and Thorold Railway. The estimate was submitted by S.D. Woodruff and George Rykert, president. There is also a disclaimer in which Calvin Phelps claims to have resigned as director of the Port Dalhousie and Thorold Railway when he discovered that the company had no intention to adhere to the original plan for building and running the road, Aug. 1854.

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Letter (2 pages, handwritten) from the office of Hart, Ball and Hart of Buffalo, New York to William R. Allen of St. Catharines, Ont. proposing work to be done regarding the hot water heating of the building. The owner of the building is expected to pay the railway fare of the men and to pay their board while they are in St. Catharines, July 8, 1876.

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Letter (4 pages, handwritten) from the office of Hart, Ball and Hart of Buffalo, New York to William R. Allen of St. Catharines elaborating on the specifications of the hot water heating for the residence of Mr. Woodruff, July 17, 1876.