95,381 research outputs found
Measuring movement fluency during the sit-to-walk task
Restoring movement fluency is a key focus for physical rehabilitation; it's measurement, however, lacks objectivity. The purpose of this study was to find whether measurable movement fluency variables differed between groups of adults with different movement abilities whilst performing the sit-to-walk (STW) movement. The movement fluency variables were: (1) hesitation during movement (reduction in forward velocity of the centre of mass; CoM), (2) coordination (percentage of temporal overlap of joint rotations) and (3) smoothness (number of inflections in the CoM jerk signal)
The Effect of Vehicle Traffic on Wildlife in Denali National Park
We recorded observations of caribou (Rangifer tarandus), grizzly bear (Ursus arctos), Dall sheep (Ovis dalli) and moose (Alces alces) along the Denali National Park and Preserve road corridor during 1995-97. We compared these observations to similar data from previous studies to evaluate the effect of an increase in traffic on the number of animals sighted and their behavior. Between 1972 and 1997, annual visitation to Denali National Park increased from about 45000 to 350000, with attendant increases in traffic on the park road. The mean number of caribou, grizzly bear, and Dall sheep observed did not decline (p > 0.301) from 1973 to 1997. The number of moose observed declined by more than 50% (RÂČ = 0.529, p < 0.001). The estimated population of moose also declined over the same period (RÂČ = 0.374, p = 0.002). The distance from the park road at which caribou and grizzly bears were sighted did not change (p > 0.787), but fewer moose (p < 0.031) were observed within 100 m of the road and fewer sheep (p < 0.011) were observed between 400 and 500 m from the road. Adverse behavioral responses to traffic (e.g., running from vehicles) occurred in less than 1.3% of observations for each species. Increased traffic on the park road apparently has not caused significant changes in abundance, distribution, or behavior of caribou, grizzly bear, Dall sheep, and moose in the park road corridor.De 1995 Ă 1997, on a rapportĂ© des observations du caribou (Rangifer tarandus), du grizzli (Ursus arctos), du mouflon de Dall (Ovis dalli) et de l'orignal (Alces alces) dans le corridor routier de la rĂ©serve et du parc national Denali. On a comparĂ© ces observations Ă des donnĂ©es similaires recueillies au cours d'Ă©tudes antĂ©rieures visant Ă Ă©valuer l'impact d'une augmentation du trafic sur le nombre d'animaux aperçus et sur leur comportement. Entre1972 et 1997, le nombre annuel de visiteurs au parc national Denali est passĂ© d'environ 45 000 Ă 350 000, ce qui a amenĂ© une augmentation de la circulation sur la route du parc. De 1973 Ă 1997, le nombre moyen de caribous, de grizzlis et de mouflons de Dall observĂ©s n'a pas diminuĂ© (p > 0,301). Le nombre d'orignaux observĂ©s a dĂ©clinĂ© de plus de 50 p. cent (RÂČ = 0,529, p < 0,001). La population d'orignaux estimĂ©e a aussi baissĂ© durant cette pĂ©riode (RÂČ = 0,374, p < 0,002). La distance, mesurĂ©e depuis la route du parc, Ă laquelle ont Ă©tĂ© aperçus les caribous et les grizzlis n'a pas changĂ© (p > 0,787), mais on a observĂ© moins d'orignaux (p < 0,031) Ă moins de 100 m de la route et moins de mouflons de Dall (p < 0,011) entre 400 et 500 m de la route. Des rĂ©actions comportementales nĂ©gatives au trafic (p. ex., fuite Ă l'approche de vĂ©hicules) ont eu lieu dans moins de 1,3 p. cent des cas observĂ©s pour chaque espĂšce. L'augmentation du trafic sur la route du parc ne semble pas avoir causĂ© de changements notables dans l'abondance, la distribution, ou le comportement du caribou, du grizzli, du mouflon de Dall et de l'orignal dans le corridor routier du parc
Unravelling the identity of Pandora species (Bivalvia: Pandoridae) from Southern South America
Four species of Pandora have been reported from southern South America: P. cistula Gould, 1850, P. braziliensis G. B. Sowerby II, 1874, P. diffissa Mabille & Rochebrune, 1889 and P. patagonica (Dall, 1915). The group has received little taxonomic attention in this area, resulting in arbitrary and wrong usage of these names, for which several contradictory synonymies have been proposed. This study provides the first revision of Pandora species living in southern South America, including photographs of the type material and descriptions of shells, gross anatomy and living animals. Out of the four species previously mentioned, P. braziliensis is here regarded as valid, including P. patagonica and P. diffissa as synonyms. The fourth species, P. cistula, remains known only from its type specimen. In addition, a new species, P. brevirostris, is described from the shallow waters of Argentina.Fil: GĂŒller, Marina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Zelaya, Diego Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y BiologĂa Experimental; Argentin
Marine mammal behavior: a review of conservation implications
This is the author accepted manuscript. The final version is available from Frontiers Media via the DOI in this record.The three orders which comprise the extant marine mammals exhibit a wide range of behaviors, varying social structures and differences in social information use. Human impacts on marine mammals and their environments are ubiquitous; from chemical and noise pollution, to marine debris, prey depletion and ocean acidification. As a result, no marine mammal populations remain entirely unaffected by human activities. Conservation may be hindered by an inadequate understanding of the behavioral ecology of some of these species. As a result of social structure, social information use, culture and even behavioral syndromes, marine mammal social groups and populations can be behaviorally heterogeneous. As a result responses to conservation initiatives, or exploitation, may be complex to predict. Previous commentators have highlighted the importance of incorporating behavioral data into conservation management and we review these considerations in light of the emerging science in this field for marine mammals. Since behavioral canalization may lead to vulnerability, whereas behavioral plasticity may provide opportunity for resilience, we argue that for many of these socially complex, cognitive species understanding their behavioral ecology, capacity for social learning and individual behavioral variation, may be a central tenant for their successful conservation.The lead authorâs research is funded by WDC (Whale and Dolphin Conservation)
New taxa and new synonymy in Muricidae (Neogastropoda: Pagodulinae, Trophoninae, Ocenebrinae) from the Northeast Pacific
The results of an extensive examination of northeast Pacific muricid gastropods ranging from Aleutian Islands, Alaska, to mid-Baja California, is presented. Two new genera and 26 new species are described: In Pagodulinae: Abyssotrophon fusiformis n. sp., A. newmani n. sp., Boreotrophon cascadiensis n. sp., B. cordellensis n. sp., B. cortesianus n. sp., B. obesus n. sp., B. subapolyonis n. sp., B. vancouverensis n. sp., B. aleuticus n. sp., B. pseudotripherus n. sp., B. santarosensis n. sp., B. tannerensis n. sp. In Trophoninae: Warenia, n. gen., Scabrotrophon buldirensis n. sp, S. kantori n. sp., S. lima n. sp., S. macleani n. sp., S. moresbyensis n. sp., S. norafosterae n. sp., S. trifidus n. sp., Nipponotrophon exquisitus n. sp. In Ocenebrinae: Paciocinebrina n. gen., Nucella angustior n. sp., Paciocinebrina benitoensis n. sp., P. macleani n. sp., P. neobarbarensis n. sp., P. pseudomunda n. sp., P. thelmacrowae n. sp. New synonymy: Boreotrophon kamchatkanus Dall, 1902 (+ Trophonopsis nanus Ergorov, 1994); Paciocinebrina atropurpurea (Carpenter, 1865) (+ Tritonalia interfossa var. clathrata Dall, 1919, Ocinebra rubra Baker, 1891, Tritonalia tracheia Dall, 1919); P. barbarensis (Gabb, 1865) (+ Tritonalia interfossa var. beta Dall, 1919, Ocenebra keenae Bormann, 1946); P. circumtexta (Stearns, 1871) (+ Ocinebra circumtexta var. aurantia Stearns, 1895, Tritonalia circumtexta var. citrica Dall, 1919, Tritonalia lurida var. rotunda Dall, 1919); P. foveolata (Hinds, 1844) (+Tritonalia epiphanea Dall, 1919, Tritonalia fusconotata Dall, 1919); P. gracillima (Stearns, 1871) (+ Tritonalia gracillima var. obesa Dall, 1919, Ocinebra stearnsi Hemphill, 1911); P. interfossa (Carpenter, 1864) (+ Tritonalia interfossa alpha Dall, 1921); P. lurida (Middendorff, 1848) (+ Vitularia aspera Baird, 1863), P. sclera (Dall, 1919) (+ Coralliophila (Pseudomurex) kincaidi Dall, 1919). Generic assignments are changed for the following taxa: Boreotrophon kamchatkanus Dall, 1902; Warenia elegantula (Dall, 1907); Scabrotrophon stuarti (E.A. Smith, 1880); Paciocinebrina atropurpurea (Carpenter, 1865), P. barbarensis (Gabb, 1865), P. circumtexta (Stearns, 1871), P. crispatissima (Berry, 1953), P. foveolata (Hinds, 1844), P. fraseri (Oldroyd, 1920), P. gracillima (Stearns, 1871), P. grippi (Dall, 1911), P. interfossa (Carpenter, 1864), P. lurida (Middendorff, 1848), P. minor (Dall, 1919), P. munda (Carpenter, 1864), P. seftoni (Chace, 1958), P. sclera (Dall, 1919). Boreotrophon alborostratus Taki, 1938, is reinstated. Abyssotrophon Egorov, 1993 and Nodulotrophon Habe & Ito, 1965 are here assigned to Pagodulinae Barco et al., 2012, based on radula morphology
Evaluation of Stage-Wise Deficit Furrow Irrigation Application on Water Advance - Recession Time and Maize Yield Components at Koga Irrigation Scheme, Ethiopia
Well-organized irrigation management has an imperative role for integrated water resources management. Deficit irrigation water application is among the most effective water management solutions. This study was conducted with the aim of evaluating the performance of stage-wise deficit irrigation (DI) application on water advance - recession time and maize yield components. Maize (Melkassa-4 type) was selected as test crop as it is known to respond well to deficit irrigation. The experiment was conducted at Koga Irrigation Scheme, Blue Nile River Basin. The field experiment was arranged in randomized complete block design (RCBD) with three replications. The result showed that level of stage-wise deficit irrigation water application had a significant (P<0.05) impact on mean advance time. The maximum advance rate across growth stages (0.144 m/s) was noted during the development stage. Effect of stage-wise application level had a significant (P<0.05) effect on agronomic parameters. The maximum (147.3 cm) and minimum (4.3 cm) plant height were recorded during late season and first growing stage at full irrigation level (Dall,0 (T6)) and application of 0.25ETc (Dall,75 (T4)) throughout the growth stages, respectively. Maximum (8.55cm) and minimum (3.17 cm) stalk diameter at knee height were obtained in treatment Dall,0 (T6) and Dall,75 (T4). Maximum (2) and minimum (1.07) number of ears per plant were obtained in full irrigation treatment (Dall,0 (T6)) and 0.25ETc irrigation treatment (Dall,75 (T4)) throughout the growing season, respectively. The highest yield (58.92 qt/ha) was obtained when full irrigation was applied in all growth stages. The maximum (164.28 qt/ha) and minimum (130.34 qt/ha) aboveground biomass were obtained when 100% of ETc and 0.25 of ETc were applied starting from the first to the end growth stages. Keywords: Agronomic parameters, Deficit irrigation, Koga irrigation scheme, Stage-wise, Water advance - recession time
The Evolution of Dispersal in Random Environments and The Principle of Partial Control
McNamara and Dall (2011) identified novel relationships between the abundance
of a species in different environments, the temporal properties of
environmental change, and selection for or against dispersal. Here, the
mathematics underlying these relationships in their two-environment model are
investigated for arbitrary numbers of environments. The effect they described
is quantified as the fitness-abundance covariance. The phase in the life cycle
where the population is censused is crucial for the implications of the
fitness-abundance covariance. These relationships are shown to connect to the
population genetics literature on the Reduction Principle for the evolution of
genetic systems and migration. Conditions that produce selection for increased
unconditional dispersal are found to be new instances of departures from
reduction described by the "Principle of Partial Control" proposed for the
evolution of modifier genes. According to this principle, variation that only
partially controls the processes that transform the transmitted information of
organisms may be selected to increase these processes. Mathematical methods of
Karlin, Friedland, and Elsner, Johnson, and Neumann, are central in
generalizing the analysis. Analysis of the adaptive landscape of the model
shows that the evolution of conditional dispersal is very sensitive to the
spectrum of genetic variation the population is capable of producing, and
suggests that empirical study of particular species will require an evaluation
of its variational properties.Comment: Dedicated to the memory of Professor Michael Neumann, one of whose
many elegant theorems provides for a result presented here. 28 pages, 1
table, 1 figur
Immunology of the canine eye in health and disease: A concise review
The canine eye is an immune-privileged organ that is provided with systems to prevent and control
the local immune response, which could have a detrimental impact. The entry of blood-derived antigens is hindered
by the blood-ocular barriers and potential invading pathogens are tackled by local antimicrobial molecules.
Despite the existence of numerous immune-competent cells, the anterior chamber of the eye is characterised by
low responsiveness. This review is focused on the innate and adaptive immunity employed to control health and
disease in the canine eye
- âŠ