575 research outputs found
High-altitude stream faunas in the Mt Pelion East-Mt Doris area of Tasmania
A survey was carried out of the aquatic fauna of the headwaters of two high-altitude 0170-1355 m) streams draining Mt Doris and two streams draining Mt Pelion East in Tasmania. Although the fauna above the treeline appeared to be characterised primarily by the loss of downstream fauna, three Trichoptera (Notoperata maculata, an unidentified genus from the Kokiriidae, and Plectrotarsus sp.) and one crustacean (Neoniphargus sp.) may form part of a specialised high-altitude fauna. The amphipod Neoniphargus sp. was collected from above the treeline only, whereas the other amphipod recorded, Antipodeus sp., was found at or below the treeline only. Cluster analyses enabled five habitat and three species groupings to be recognised. Since the habitat groupings were generally well defined by their physico-chemical characteristics as well as by the faunal groups, it is concluded that they reflect a genuine series of identifiable high-altitude stream habitats
Even Between-Lap Pacing Despite High Within-Lap Variation During Mountain Biking
Purpose: Given the paucity of research on pacing strategies during competitive events, this study examined
changes in dynamic high-resolution performance parameters to analyze pacing profiles during a multiple-lap
mountain-bike race over variable terrain. Methods: A global-positioning-system (GPS) unit (Garmin, Edge
305, USA) recorded velocity (m/s), distance (m), elevation (m), and heart rate at 1 Hz from 6 mountain-bike
riders (mean ± SD age = 27.2 ± 5.0 y, stature = 176.8 ± 8.1 cm, mass = 76.3 ± 11.7 kg, VO2max = 55.1 ± 6.0 mL
· kg–1 . min–1) competing in a multilap race. Lap-by-lap (interlap) pacing was analyzed using a 1-way ANOVA
for mean time and mean velocity. Velocity data were averaged every 100 m and plotted against race distance
and elevation to observe the presence of intralap variation. Results: There was no significant difference in lap times (P = .99) or lap velocity (P = .65) across the 5 laps. Within each lap, a high degree of oscillation in velocity was observed, which broadly reflected changes in terrain, but high-resolution data demonstrated additional
nonmonotonic variation not related to terrain. Conclusion: Participants adopted an even pace strategy across
the 5 laps despite rapid adjustments in velocity during each lap. While topographical and technical variations
of the course accounted for some of the variability in velocity, the additional rapid adjustments in velocity
may be associated with dynamic regulation of self-paced exercise
Gastrointestinal stromal tumour and hypoglycemia in a Fjord pony: Case report
<p>Abstract</p> <p>Background</p> <p>Neoplasia may cause hypoglycemia in different species including the horse, but hypoglycemia has not previously been reported in the horse associated with gastrointestinal stromal tumours.</p> <p>Case presentation</p> <p>A case of a gastrointestinal stromal tumour in a Fjord pony with severe recurrent hypoglycemia is presented. The mechanism causing the hypoglycemia was not established.</p> <p>Conclusion</p> <p>This case indicates that a gastrointestinal stromal tumour may cause hypoglycemia also in the horse.</p
Demographic and Psychological Predictors of Parent–Adolescent Communication About Sex: A Representative Statewide Analysis
Sexual communication is a principal means of transmitting sexual values, beliefs, expectations, and knowledge between parents and children. Although this area has received considerable research attention, more studies with representative samples are needed to assure that findings are reflective of populations of interest. A representative statewide sample of households with adolescents (N = 907) from a large and diverse state in the United States was employed to examine the content and extent of sexual communication between parents and their adolescents, and the influence of selected primary demographic (age and gender), socio-demographic (Hispanic ethnicity, education, and religious attendance), and psychological (self-reported comfort, knowledge, and sexual communication difficulties) factors on the number of topics discussed. More than two-thirds of the parents reported experiencing some type of sexual communication difficulty, such as developmental concerns and embarrassment. Hierarchical regression results indicated that self-reported comfort, knowledge, and sexual communication difficulties strongly predicted the number of topics discussed, beyond the effect of demographic variables. These findings reinforce the notion that sexual communication between parents and adolescents can be universally challenging, and parents of both genders, all ages, and all socio-demographic characteristics might benefit from education and support
Four Regional Marine Biodiversity Studies: Approaches and Contributions to Ecosystem-Based Management
We compare objectives and approaches of four regional studies of marine biodiversity: Gulf of Maine Area Census of Marine Life, Baltic Sea History of Marine Animal Populations, Great Barrier Reef Seabed Biodiversity Project, and Gulf of Mexico Biodiversity Project. Each program was designed as an "ecosystem" scale but was created independently and executed differently. Each lasted 8 to 10 years, including several years to refine program objectives, raise funding, and develop research networks. All resulted in improved baseline data and in new, or revised, data systems. Each contributed to the creation or evolution of interdisciplinary teams, and to regional, national, or international science-management linkages. To date, there have been differing extents of delivery and use of scientific information to and by management, with greatest integration by the program designed around specific management questions. We evaluate each research program's relative emphasis on three principal elements of biodiversity organization: composition, structure, and function. This approach is used to analyze existing ecosystem-wide biodiversity knowledge and to assess what is known and where gaps exist. In all four of these systems and studies, there is a relative paucity of investigation on functional elements of biodiversity, when compared with compositional and structural elements. This is symptomatic of the current state of the science. Substantial investment in understanding one or more biodiversity element(s) will allow issues to be addressed in a timely and more integrative fashion. Evaluating research needs and possible approaches across specific elements of biodiversity organization can facilitate planning of future studies and lead to more effective communication between scientists, managers, and stakeholders. Building a general approach that captures how various studies have focused on different biodiversity elements can also contribute to meta-analyses of worldwide experience in scientific research to support ecosystem-based management
Measurement of the Forward-Backward Asymmetry in the B -> K(*) mu+ mu- Decay and First Observation of the Bs -> phi mu+ mu- Decay
We reconstruct the rare decays , , and in a data sample
corresponding to collected in collisions at
by the CDF II detector at the Fermilab Tevatron
Collider. Using and decays we report the branching ratios. In addition, we report
the measurement of the differential branching ratio and the muon
forward-backward asymmetry in the and decay modes, and the
longitudinal polarization in the decay mode with respect to the squared
dimuon mass. These are consistent with the theoretical prediction from the
standard model, and most recent determinations from other experiments and of
comparable accuracy. We also report the first observation of the {\mathcal{B}}(B^0_s \to
\phi\mu^+\mu^-) = [1.44 \pm 0.33 \pm 0.46] \times 10^{-6}27 \pm 6B^0_s$ decay observed.Comment: 7 pages, 2 figures, 3 tables. Submitted to Phys. Rev. Let
Search for a New Heavy Gauge Boson Wprime with Electron + missing ET Event Signature in ppbar collisions at sqrt(s)=1.96 TeV
We present a search for a new heavy charged vector boson decaying
to an electron-neutrino pair in collisions at a center-of-mass
energy of 1.96\unit{TeV}. The data were collected with the CDF II detector
and correspond to an integrated luminosity of 5.3\unit{fb}^{-1}. No
significant excess above the standard model expectation is observed and we set
upper limits on . Assuming standard
model couplings to fermions and the neutrino from the boson decay to
be light, we exclude a boson with mass less than
1.12\unit{TeV/}c^2 at the 95\unit{%} confidence level.Comment: 7 pages, 2 figures Submitted to PR
Measurements of the properties of Lambda_c(2595), Lambda_c(2625), Sigma_c(2455), and Sigma_c(2520) baryons
We report measurements of the resonance properties of Lambda_c(2595)+ and
Lambda_c(2625)+ baryons in their decays to Lambda_c+ pi+ pi- as well as
Sigma_c(2455)++,0 and Sigma_c(2520)++,0 baryons in their decays to Lambda_c+
pi+/- final states. These measurements are performed using data corresponding
to 5.2/fb of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV,
collected with the CDF II detector at the Fermilab Tevatron. Exploiting the
largest available charmed baryon sample, we measure masses and decay widths
with uncertainties comparable to the world averages for Sigma_c states, and
significantly smaller uncertainties than the world averages for excited
Lambda_c+ states.Comment: added one reference and one table, changed order of figures, 17
pages, 15 figure
Order and Stochastic Dynamics in Drosophila Planar Cell Polarity
Cells in the wing blade of Drosophila melanogaster exhibit an in-plane polarization causing distal orientation of hairs. Establishment of the Planar Cell Polarity (PCP) involves intercellular interactions as well as a global orienting signal. Many of the genetic and molecular components underlying this process have been experimentally identified and a recently advanced system-level model has suggested that the observed mutant phenotypes can be understood in terms of intercellular interactions involving asymmetric localization of membrane bound proteins. Among key open questions in understanding the emergence of ordered polarization is the effect of stochasticity and the role of the global orienting signal. These issues relate closely to our understanding of ferromagnetism in physical systems. Here we pursue this analogy to understand the emergence of PCP order. To this end we develop a semi-phenomenological representation of the underlying molecular processes and define a “phase diagram” of the model which provides a global view of the dependence of the phenotype on parameters. We show that the dynamics of PCP has two regimes: rapid growth in the amplitude of local polarization followed by a slower process of alignment which progresses from small to large scales. We discuss the response of the tissue to various types of orienting signals and show that global PCP order can be achieved with a weak orienting signal provided that it acts during the early phase of the process. Finally we define and discuss some of the experimental predictions of the model
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