642 research outputs found
Gyrfalcon Feeding Behaviour during the Nestling Period in Central West Greenland
We studied gyrfalcon (Falco rusticolus) food delivery and feeding behavior during the nestling period in central West Greenland during the 2000 and 2001 field seasons. We used time-lapse video cameras installed at three nests to record 2677.25 hours of nestling video. Ptarmigan delivered to nests were usually plucked prior to delivery and included the breast and superior thoracic vertebrae. Arctic hare leverets were rarely plucked and often delivered in parts. The most commonly delivered leveret part was the hind legs attached to the lower back. Passerines were rarely plucked and usually delivered whole. After feeding the young, adults removed 20.9% of prey items from the nest, which included items both with and without obvious muscle still attached. Prey delivery rates were similar among nests and increased as nestlings aged. Prey delivery frequency peaked in the morning and evening, with a distinct lull in the late evening and early morning hours. Male and female adults delivered a similar number of prey, though males typically delivered smaller prey than females. Gyrfalcons cached and re-delivered at least 9.1% of all items delivered, and one item was cached and retrieved three times.Durant les campagnes sur le terrain de 2000 et 2001 dans le centre du Groenland occidental, on a étudié chez le faucon gerfaut (Falco rusticolus) l'apport en nourriture et le comportement alimentaire pendant le séjour au nid. À l'aide de caméras vidéo filmant à intervalles, installées à trois nids, on a enregistré 2677,25 heures de vidéo au nid. Les lagopèdes apportés au nid étaient en général plumés avant d'y être déposés et comprenaient la poitrine et les vertèbres supérieures du thorax. Les jeunes lièvres arctiques étaient rarement pelés et étaient souvent apportés en morceaux. La partie du levraut la plus communément apportée était les pattes arrière rattachées au bas du dos. Les passereaux étaient rarement plumés et étaient en général livrés entiers. Après avoir nourri leurs petits, les adultes enlevaient du nid environ 20,9 % des parties des proies, comprenant des morceaux qui pouvaient comporter ou non du tissu musculaire évident. Le rythme de l'apport des proies était semblable parmi les divers nids et augmentait avec l'âge des oisillons. La fréquence de l'apport des proies passait par un maximum le matin et le soir, avec une accalmie très nette tard dans la soirée et au petit matin. Les mâles et les femelles adultes apportaient le même nombre de proies, mais les mâles livraient en général de plus petites proies que les femelles. Les faucons gerfauts dissimulaient dans une cache puis ressortaient par la suite au moins 9,1 % de tous les morceaux apportés, et un morceau a été dissimulé et ressorti trois fois
Booster Obsolescence and Life Extension (BOLE) for Space Launch System (SLS)
A human mission to the moon and Mars is the stated space exploration goal of the United States and the international community. To achieve these goals, NASA is developing the Space Launch System (SLS) and the Orion crew capsule as key elements in the architecture for missions to the moon and Mars. As part of the SLS Booster Obsolescence and Life Extension (BOLE) program, Northrop Grumman Space Systems is working to address booster obsolescence issues in design and manufacturing. The upgraded boosters will also provide increased performance that will benefit future lunar campaigns, science missions, and the eventual Mars campaign
Wintering Bald Eagle Count Trends in the Conterminous United States, 1986-2010
We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles (Haliaeetus leucocephalus) within the conterminous 48 United States from 1986 to 2010. Using hierarchical mixed model methods, we report trends in counts from 11 729 surveys along 844 routes in 44 states. Nationwide Bald Eagle counts increased 0.6% per yr over the 25-yr period, compared to an estimate of 1.9% per yr from 1986 to 2000. Trend estimates for Bald Eagles were significant (P ≤ 0.05) and positive in the northeastern and northwestern U.S. (3.9% and 1.1%, respectively), while trend estimates for Bald Eagles were negative (P ≤ 0.05) in the southwestern U.S. (-2.2%). After accounting for potential biases resulting from temporal and regional differences in surveys, we believe trends reflect post-DDT recovery and subsequent early effects of density-dependent population regulation
Wintering Area DDE Source to Migratory White-Faced Ibis Revealed by Satellite Telemetry and Prey Sampling
Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyl-dichloroethylene (DDE) with no change, which is unusual, observed in egg concentrations between 1985 and 2000. About 45 to 63% of the earliest nesting segment shows reduced reproductive success correlated with elevated egg concentrations of \u3e 4 µg/g wet weight (ww). Local prey (primarily earthworms) near nests contained little DDE so we tracked the migration and wintering movements of 20 adult males during 2000-2004 to determine the possible source. At various wintering sites, we found a correlation (r2 = 0.518, P = 0.0125, N = 11) between DDE in earthworm composites and DDE in blood plasma of white-faced ibis wintering there, although the plasma was collected on their breeding grounds soon after arrival. The main source of DDE was wintering areas in the Mexicali Valley of Baja California Norte, Mexico, and probably the adjacent Imperial Valley, California, USA. This unusual continuing DDE problem for white-face ibis is associated with: the long-term persistence in soil of DDE; the earthworms’ ability to bioconcentrate DDE from soil; the proclivity of white-faced ibis to feed on earthworms in agricultural fields; the species extreme sensitivity to DDE in their eggs; and perhaps its life history strategy of being a “capital breeder”. We suggest surveying and sampling white-faced ibis eggs at nesting colonies, especially at Carson Lake, to monitor the continuing influence of DDE
Investigation of the structure and magnetism in lanthanide ß-triketonate tetranuclear assemblies
The preparation of discrete tetranuclear lanthanide/alkali metal (Ae) assemblies bearing a tribenzoylmethane ligand (LH) is discussed. These assemblies have the general formula [Ln(Ae·HOEt)(L)4]2, where Ln3+ = Gd3+, Tb3+, Dy3+, Ho3+ and Ae+ = Na+, K+, Rb+. The coordination geometries of the lanthanide species were analyzed and compared, revealing a trend between an eight-coordinate square antiprism and triangular dodecahedron dependent on the nature of lanthanide, alkali metal, and lattice solvent. The potassium-containing analogs were also analyzed for their magnetic susceptibility
Anti-epileptic drugs and bone loss: phenytoin reduces pro-collagen I and alters the electrophoretic mobility of osteonectin in cultured bone cells.
Phenytoin is an antiepileptic drug used in the management of partial and tonic-clonic seizures. In previous studies we have shown that valproate, another antiepileptic drug, reduced the amount of two key bone proteins, pro-collagen I and osteonectin (SPARC, BM-40), in both skin fibroblasts and cultured osteoblast-like cells. Here we show that phenytoin also reduces pro-collagen I production in osteoblast-like cells, but does not appear to cause a decrease in osteonectin message or protein production. Instead, a 24h exposure to a clinically relevant concentration of phenytoin resulted in a dose-dependent change in electrophoretic mobility of osteonectin, which was suggestive of a change in post-translational modification status. The perturbation of these important bone proteins could be one of the mechanisms to explain the bone loss that has been reported following long-term treatment with phenytoin
Booster Obsolescence and Life Extension (BOLE) for Space Launch System (SLS)
A human mission to the moon and Mars is the stated space exploration goal of the United States and the international community. To achieve these goals, NASA is developing the Space Launch System (SLS) and the Orion crew capsule as key elements in the architecture for missions to the moon and Mars. As part of the SLS Booster Obsolescence and Life Extension (BOLE) program, Northrop Grumman Innovation Systems is working to address booster obsolescence issues in design and manufacturing. The upgraded boosters will also provide increased performance that will benefit future lunar campaigns, science missions, and the eventual Mars campaign
Theology, News and Notes - Vol. 47, No. 02
Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1140/thumbnail.jp
Low Mass Printable Devices for Energy Capture, Storage, and Use
The energy-efficient, environmentally friendly technology that will be presented is the result of a Space Act Agreement between NthDegree Technologies Worldwide, Inc., and the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC). The work combines semiconductor and printing technologies to advance lightweight electronic and photonic devices having excellent potential for commercial and exploration applications. Device development involves three projects that relate to energy generation and consumption: (1) a low-mass efficient (low power, low heat emission) micro light-emitting diode (LED) area lighting device; (2) a low-mass omni-directional efficient photovoltaic (PV) device with significantly improved energy capture; and (3) a new approach to building super-capacitors. These three technologies, energy capture, storage, and usage (e.g., lighting), represent a systematic approach for building efficient local micro-grids that are commercially feasible; furthermore, these same technologies, appropriately replacing lighting with lightweight power generation, will be useful for enabling inner planetary missions using smaller launch vehicles and to facilitate surface operations during lunar and planetary surface missions. The PV device model is a two sphere, light trapped sheet approximately 2-mm thick. The model suggests a significant improvement over current thin film systems. For lighting applications, all three technology components are printable in-line by printing sequential layers on a standard screen or flexographic direct impact press using the three-dimensional printing technique (3DFM) patented by NthDegree. One primary contribution to this work in the near term by the MSFC is to test the robustness of prototype devices in the harsh environments that prevail in space and on the lunar surface. It is anticipated that this composite device, of which the lighting component has passed off-gassing testing, will function appropriately in such environments consistent with NASA s exploration missions. Advanced technologies such as this show promise for both space flight and terrestrial applications
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