7,892 research outputs found
Reactions of Large Groups of Caribou to a Pipeline Corridor on the Arctic Coastal Plain of Alaska
Two large groups of mosquito-harassed caribou (Rangifer tarandus granti) were followed for 8-12 h as they repeatedly attempted to cross an elevated pipeline in the Kuparuk Development Area near Prudhoe Bay, Alaska. In 1981, 46% of a group of 917 eventually crossed beneath elevated portions of the pipeline in 26 separate attempts, 13% crossed a section of buried pipe in two attempts, 22% trotted parallel to the pipeline for 32 km and did not cross, and 19% separated from the group and were not accounted for. In 1982, 26% of a group of 655 crossed under elevated portions of the pipeline in 36 attempts, 37% crossed at a buried section in one attempt, and 37% left the main group and could not be accounted for. The majority of crossing attempts occured near intersections of lakes with the road/pipeline complex, but crossing success was highest at a section of buried pipe isolated from the road traffic.Key words: caribou, pipeline, petroleum development, insect harassment, Kuparuk Oil FieldMots clés: caribou, pipe-line, développement pétrolifère, harcèlement par les moustiques, champ pétrolifère Kuparu
Effects of hybrid maturity and growth stage on yield and composition of forage and grain sorghums when harvested as silage
Thirteen sorghum hybrids chosen to represent a range of sorghum types
were evaluated in two separate trials. Each was harvested at three stages of grain
development: milk to early-dough, late-dough, and hard-grain.
Among the forage sorghums, there was a 26-day range in days to half bloom
from early to late maturing varieties. Harvest date did not affect crude protein
content. However, whole-plant DM yield was significantly lower at the last
harvest for the three latest maturing varieties. Grain yield increased over time in
the early and intermediate hybrids. Lodging increased significantly over time for
all varieties except DeKalb FS-25E.
Among the grain sorghums, there was only a 4-day range in days to half
bloom and very little difference in plant height. The forage sorghum was later
maturing and taller. Whole-plant DM yields for the grain sorghums were highest at
late-dough. Grain yields and grain to forage ratios generally increased with
maturity, except when there were losses due to birds. Grain sorghums started to
lodge by the hard-grain stage
Central Arctic Caribou and Petroleum Development: Distributional, Nutritional, and Reproductive Implications
We synthesize findings from cooperative research on effects of petroleum development on caribou (Rangifer tarandus granti) of the Central Arctic Herd (CAH). The CAH increased from about 6000 animals in 1978 to 23000 in 1992, declined to 18 000 by 1995, and again increased to 27 000 by 2000. Net calf production was consistent with changes in herd size. In the Kuparuk Development Area (KDA), west of Prudhoe Bay, abundance of calving caribou was less than expected within 4 km of roads and declined exponentially with road density. With increasing infrastructure, high-density calving shifted from the KDA to inland areas with lower forage biomass. During July and early August, caribou were relatively unsuccessful in crossing road/pipeline corridors in the KDA, particularly when in large, insect-harassed aggregations; and both abundance and movements of females were lower in the oil field complex at Prudhoe Bay than in other areas along the Arctic coast. Female caribou exposed to petroleum development west of the Sagavanirktok River may have consumed less forage during the calving period and experienced lower energy balance during the midsummer insect season than those under disturbance-free conditions east of the river. The probable consequences were poorer body condition at breeding and lower parturition rates for western females than for eastern females (e.g., 1988–94: 64% vs. 83% parturient, respectively; p = 0.003), which depressed the productivity of the herd. Assessments of cumulative effects of petroleum development on caribou must incorporate the complex interactions with a variable natural environment.On a procédé à une synthèse des résultats de travaux de recherche coopérative concernant les effets de l’exploitation pétrolière sur le caribou (Rangifer tarandus granti) formant la harde du centre de l’Arctique (HCA). La population de celle-ci est passée de 6000 têtes en 1978 à 23 000 en 1992, puis a diminué à 18 000 en 1995 pour augmenter de nouveau à 27 000 en 2000. La production nette des veaux allait de pair avec les changements dans la taille de la harde. Dans la zone de développement de Kuparuk (KDA), située à l’ouest de Prudhoe Bay, l’abondance des caribous qui mettaient bas était inférieure à celle prévue dans une bande de 4 km de part et d’autre des routes, et elle déclinait de façon exponentielle avec la densité routière. Avec une augmentation des infrastructures, on assistait à un déplacement du vêlage à forte densité de la KDA vers des zones de l’intérieur ayant une biomasse de fourrage moins importante. Durant juillet et au début d’août, il était assez rare que les caribous réussissent à traverser les corridors routiers/pipeliniers dans la KDA, surtout lorsqu’ils formaient de vastes agrégations harcelées par les insectes; l’abondance de même que les déplacements des femelles étaient en outre moindres au sein du complexe pétrolier de Prudhoe Bay qu’à d’autres endroits situés le long du rivage arctique. Il est possible que les femelles qui étaient exposées à l’exploitation pétrolière à l’ouest de la rivière Sagavanirktok aient consommé moins de fourrage au cours de la période de vêlage et que, durant la saison des insectes au milieu de l’été, elles aient connu une balance énergétique inférieure à celle des femelles vivant sans perturbations à l’est de la rivière. Les conséquences probables étaient un état corporel de qualité inférieure au moment de l’accouplement, et des taux de parturition plus faibles pour les femelles situées à l’ouest que pour celles situées à l’est (p. ex., de 1988 à 1994: 64 % c. 83 % de parturientes respectivement: p = 0,003), faisant ainsi baisser la productivité de la harde. Les évaluations des effets cumulatifs de l’exploitation pétrolière sur le caribou doivent intégrer les interactions complexes avec un environnement naturel variable
Design and Test of Mixed-flow Impellers VIII : Comparison of Experimental Results for Three Impellers with Shroud Redesigned by Rapid Approximate Method
Redistribution of Calving Caribou in Response to Oil Field Development on the Arctic Slope of Alaska
Aerial surveys were conducted annually in June 1978-87 near Prudhoe Bay, Alaska, to determine changes in the distribution of calving caribou (Rangifer tarandus granti) that accompanied petroleum-related development. With construction of an oil field access road through a calving concentration area, mean caribou density (no./sq. km) decreased from 1.41 to 0.31 (P=0.05) with 1 km and increased from 1.41 to 4.53 (P=0.04) 5-6 km from the road. Concurrently, relative caribou use of the adjacent area declined (P<0.02), apparently in response to increasing surface development. We suggest that perturbed distribution associated with roads reduced the capacity of the nearby area to sustain parturient females and that insufficient spacing of roads may have depressed overall calving activity. Use of traditional calving grounds and of certain areas therein appears to favor calf survival, principally through lower predation risk and improved foraging conditions. Given the possible loss of those habitats through displacement and the crucial importance of the reproductive process, a cautious approach to petroleum development on the Arctic Slope is warranted.Key words: Alaska, calving, caribou, disturbance, oil fieldRÉSUMÉ. Des photographies aériennes ont été prises au mois de juin chaque année de 1978 à 1987 près de la baie Prudhoe en Alaska, en vue de déterminer les changements dans la distribution des caribous (Rangifer tarandus granti) qui mettaient bas, changements accompagnant les projets de mise en valeur reliés au pétrole. Avec la construction d’une route d’accès à un champ pétrolifère à travers une zone importante de mise bas, la densité moyenne du caribou (nombre d’individus/km2) diminuait de 1,41 à 0,31 (P = 0,OS) à moins d’1 km de la route et augmentait de 1,41 à 4,53 (P = 0,04) à une distance de 516 km de la route. En même temps, l’utilisation relative de la zone adjacente par le caribou diminuait (P < 0,02), apparemment enréponse à l’augmentation de la mise en valeur de surface. On suggère que la perturbation de la distribution associée à la construction de routes diminuait la capacité de la zone environnante à supporter des femelles parturientes et qu’un espacement insuffisant des routes aurait pu faire chuter l’activité générale de mise bas. L’utilisation de terrains traditionnels de mise bas ainsi que de certaines zones à l’intérieur de ces terrains semble favoriser la survie des veaux, en particulier grâce à une baisse de la prédation et à de meilleures conditions de pâturage. Étant donné que le caribou pourrait être évincé de cet habitat et vu l’importance cruciale du processus de reproduction, on recommande une approche prudente à l’exploitation du pétrole sur le versant arctique.Mots clés: Alaska, mise bas, caribou, perturbation, champ pétrolifèr
Population Variations of Cheiloscopy Patterns: A Cross-Sectional Observation Pilot Study
Purpose Lip prints are unique and have potential for use as a human identifier. The purpose of this study was to observe possible cheiloscopy differences of individuals with and without parafunctional oral habits such as smoking, vaping, playing a wind instrument or using an asthma inhaler. Methods This IRB approved blinded cross-sectional observation pilot study collected lip prints from sixty-six individuals, three of which were excluded. Participants cleansed their lips, then lipstick was applied to the vermillion zones of the upper and lower lips. Adhesive tape was applied to the lips and prints were transferred to white bond paper for viewing purposes. Each set of included lip prints was divided into quadrants and dichotomized into a group of those with an oral parafunctional habit or with no such habits. Each quadrant sample was then manually analyzed and classed according to the gold standard Suzuki and Tsuchihashi system. Results A total of 252 dichotomized lip print quadrants (with habits n=76, 30.2%, and without habits n=176, 69.8%) were analyzed. Type II patterns were the most common for examined quadrant samples; however, no statistically significant differences (Pearson’s chi-squared test, p=0.366) were observed between pattern classifications of samples with and without parafunctional oral habits. Conclusion There is no statistically significant difference of lip print patterns between individuals with and without parafunctional oral habits. Further research on populational variations is needed for cheiloscopy to aid in human identifications
The Replacement of Aromatic Hydroxyl by Chlorine
Some phenols, particularly those activated by nitro-, carboxyl, or other meta-directing groups in the ortho or para positions are known to react with phosphorus pentachloride with replacement of the phenolic hydroxyl by chlorine. This transformation has also been accomplished in some cases by treating the phenol with p-toluenesulfonyl chloride in the presence of a tertiary amine such as N,N-dimethylaniline. A notable example of the latter reaction is the conversion of 2,4-dinitro-naphthol to 2,4-dinitro-1-chloronaphthalene (1). We have studied the replacement of phenolic hydroxyl by chlorine in several different cases. Our results suggest that the nature of the reaction may be influenced both by the activating effect of the other ring substituents and also by the steric effects of the other substituents
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