2,556 research outputs found
Avian Use of Rural Roadsides with Cattail (Typha spp.)
We surveyed 30 roadsides in North Dakota’s Prairie Pothole Region for birds and active nests between May and July 2001–2002. Each roadside transect was 1608 m and had ≥200 linear meters of standing cattail (Typha spp.). We recorded 45 bird species; four species of Icteridae dominated the avifauna. Red-winged blackbirds (Agelaius phoeniceus) were both the most abundant species and most abundant nester, averaging 53 birds/10 ha (SE = 7.7) and 30 nests/10 ha (SE = 9.7). Among non-icterid species, song sparrow (Melospiza melodia) and common yellowthroat (Geothlypis trichas) ranked first and second consecutively in 2001 and 2002. Canonical correspondence analyses of species compositions indicated that species abundance was related to two roadside variables, length and water depth of cattail stands. Cattails added habitat diversity and acceptable conditions for wetland-dwelling avian species not typically found in rural roadsides outside of the Prairie Pothole Region. We documented use of roadsides by three species of grassland birds of national or regional conservation concern. Roadsides in North Dakota, although dominated mostly by generalist bird species with edge tolerance, may have some management potential for area-dependent grassland birds
Meteorological and oceanographic data collected during the ASREX 91 field experiment
The 1991 Acoustic Surface Reverberation Experiment (ASREX 91) took place in November and December off the coast of
British Columbia. As part of this experiment, three moorings were deployed to characterize the environmental background. The
moorings consisted of a meteorological/oceanographic mooring designed to measure surface meteorology, current and temperature
in the upper 120 meters, and nondirectional wave parameters and two wave moorings which were instrumented with pitch-roll
buoys to characterize the directional wave spectrum. This report presents results from these three moorings. The conditions seen
during the experiment were extremely rough, with wind speeds at 3.4m above the water surface reaching a maximum of 22 m/s
and wave heights reaching a maximum of over 10 meters. The air-sea flux of heat was strongly cooling, and the mixed layer
deepened over the course of the experiment from approximately 40 to approximately 70 meters. Spectra of the temperature showed
a strong semidiurnal tidal signal associated with temperature excursions of several degrees C. The velocity signal showed strong
inertial oscilations with amplitudes of 30-50 cm/s. Weaker low-frequency and semidiurnal tidal signals were also seen. The waves
were very strong with significant wave heights of 5-6 meters persisting for up to 2 weeks at a time. Waves were generally out of
the south or the west.Funding was provided by the Ocean Acoustics Program (Code 324OA) of the Office of Naval
Research under contract N00014-91-J-1891
Kinematic Analysis of Four Plyometric Push-Up Variations
International Journal of Exercise Science 5(4) : 334-343, 2012. Plyometric research in the upper extremity is limited, with the effects of open-chain plyometric exercises being studied most. Kinematic and ground reaction force data concerning closed-chain upper extremity plyometrics has yet to be examined. Twenty-one recreationally active male subjects performed four variations of plyometric push-ups in a counterbalanced order. These included box drop push-ups from 3.8 cm, 7.6 cm, 11.4 cm heights, and clap push-ups. Kinematics of the trunk, dominant extremity and both hands were collected to examine peak flight, elbow flexion at ground contact, elbow displacement, and hand separation. Additionally peak vertical ground reaction force was measured under the dominant extremity. The 11.4 cm and clap push-ups had significantly higher peak flight than the other variations (P\u3c.001). At ground contact, the elbow was in significantly greater flexion for the 3.8 cm and clap push-up compared to the other variations (P\u3c.001). The clap push-up had significantly more elbow displacement than the other variations (P\u3c.001) while hand separation was not significantly different between variations (P=.129). Peak vertical ground reaction force was significantly greater for the clap push-ups than for all other variations (P\u3c .001). Despite similar flight heights between the 11.4 cm and clap push-ups, the greater peak vertical ground reaction force and elbow displacement of the clap push-ups indicates the clap push-up is the most intense of the variations examined. Understanding the kinematic variables involved will aid in the creation of a closed chain upper-extremity plyometric progression
Return to Sport after Surgical Treatment of Lisfranc Injuries in Athletes: A Retrospective Case Series
Introduction
A Lisfranc injury can be a devastating injury in athletes,and if inadequately treated, may lead to chronic pain and lossof function. The purpose of this study was to determine the rate andtime until return to sport after surgical fixation for a ligamentous Lisfrancinjury. We hypothesized that open reduction and screw fixationof a ligamentous Lisfranc injury can be a successful treatment in theathletic population and allow patients to return to sport at close totheir preinjury level of play.
Methods
All patients who were analyzed underwent repair of aligamentous Lisfranc injury with open reduction and screw fixationby a single surgeon, were between 18 - 40 years old at time of theirfinal follow up, and were identified as being an athlete (either recreationalor competitive). Eligible patients were given a questionnairethat included if they were able to return to sport, time until return tosport, subjective percentage of pre-injury level of play, current pain(0 - 10), and complications.
Results
Eleven patients were identified as athletes. Ten (91%) wereavailable for follow-up with a mean of 36.5 months (range, 14 - 60).The average age was 25.4 years (range, 15 - 37) at time of surgery.Eighty percent (8/10) were able to return to sport. The average timeuntil return to sport was 29.4 weeks (range, 22 - 52) with an averagesubjective value of their pre-injury level of play of 87% (range, 70 -100%). However, 67% (6/9) of the athletes had occasional pain withsport with an average pain level of 2.1 (range, 0 - 5). Two patientshad complications, a superficial infection and a deep vein thrombosis.
Conclusion
Most athletes were able to return to sport after undergoingopen reduction and internal fixation of a ligamentous Lisfrancinjury by less than 30 weeks post-surgery with a subjective value of87% of their previous function. However, the majority of the patientsalso experienced some residual pain with their respective sport.These findings suggested that athletes with a ligamentous Lisfrancinjury can have reliably good outcomes with operative repair
An Atlas of Warm AGN and Starbursts from the IRAS Deep Fields
We present 180 AGN candidates based on color selection from the IRAS
slow-scan deep observations, with color criteria broadened from the initial
Point-Source Catalog samples to include similar objects with redshifts up to
z=1 and allowing for two-band detections. Spectroscopic identifications have
been obtained for 80 (44%); some additional ones are secure based on radio
detections or optical morphology, although yet unobserved spectroscopically.
These spectroscopic identifications include 13 Sy 1 galaxies, 17 Sy 2 Seyferts,
29 starbursts, 7 LINER systems, and 13 emission-line galaxies so heavily
reddened as to remain of ambiguous classification. The optical magnitudes range
from R=12.0-20.5; counts suggest that incompleteness is important fainter than
R=15.5. Redshifts extend to z=0.51, with a significant part of the sample at
z>0.2. The sample includes slightly more AGN than star-forming systems among
those where the spectra contain enough diagnostic feature to make the
distinction. The active nuclei include several broad-line objects with strong
Fe II emission, and composite objects with the absorption-line signatures of
fading starbursts. These AGN with warm far-IR colors have little overlap with
the "red AGN" identified with 2MASS; only a single Sy 1 was detected by 2MASS
with J-K > 2. Some reliable IRAS detections have either very faint optical
counterparts or only absorption-line galaxies, potentially being deeply
obscured AGN. The IRAS detections include a newly identified symbiotic star,
and several possible examples of the "Vega phenomenon", including dwarfs as
cool as type K. Appendices detail these candidate stars, and the
optical-identification content of a particularly deep set of high-latitude IRAS
scans (probing the limits of optical identification from IRAS data alone).Comment: ApJ Suppl, in press. Figures converted to JPEG/GIF for better
compression; PDF with full-resolution figures available before publication at
http://www.astr.ua.edu/keel/aoagn.pd
Earth Observations and Integrative Models in Support of Food and Water Security
Global food production depends upon many factors that Earth observing satellites routinely measure about water, energy, weather, and ecosystems. Increasingly sophisticated, publicly-available satellite data products can improve efficiencies in resource management and provide earlier indication of environmental disruption. Satellite remote sensing provides a consistent, long-term record that can be used effectively to detect large-scale features over time, such as a developing drought. Accuracy and capabilities have increased along with the range of Earth observations and derived products that can support food security decisions with actionable information. This paper highlights major capabilities facilitated by satellite observations and physical models that have been developed and validated using remotely-sensed observations. Although we primarily focus on variables relevant to agriculture, we also include a brief description of the growing use of Earth observations in support of aquaculture and fisheries
The Marine light - mixed layer experiment cruise and data report, R/V Endeavor : cruise EN-224, mooring deployment, 27 April-1 May 1991, cruise EN-227, mooring recovery, 5-23 September 1991
The Marine Light - Mixed Layer experiment took place in the sub-Arctic North Atlantic ocean, approximately 275 miles
south of Reykjavik, Iceland. The field program included a central surface mooring to document the temporal evolution of physical,
biological and optical properties. The surface mooring was deployed at approximately 59°N, 21°W on 29 April 1991 and recovered
on 6 September 1991. The Upper Ocean Processes Group of the Woods Hole Oceanographic Institution was responsible for design,
preparation, deployment, and recovery of the mooring. The Group's contrbution to the field measurements included four different
types of sensors: a meteorological observation package on the surface buoy, a string of 15 temperature sensors along the mooring
line, an acoustic Doppler current profiler, and four instruments for measuring mooring tension and accelerations. The observations
obtained from the mooring are sufficient to describe the air-sea fluxes and the local physical response to surface forcing. The
objective in the analysis phase will be to determine the factors controlling this physical response and to work towards an understanding
of the links among physical, biological, and optical processes. This report describes the deployment and recovery of the
mooring, the meteorological data, and the subsurface temperature and current data.Funding was provided by the Office of Naval Research under Contract N00014-89-J-1683
The Very Young Radio Pulsar J1357-6429
We report the discovery of a radio pulsar with a characteristic age of 7300 years, making it one of the 10 apparently youngest Galactic pulsars known. PSR J1357-6429, with a spin period of P = 166 ms and spin-down luminosity of 3.1e36 ergs/s, was detected during the Parkes multibeam survey of the Galactic plane. We have measured a large rotational glitch in this pulsar, with Delta P/P = -2.4e-6, similar in magnitude to those experienced occasionally by the Vela pulsar. At a nominal distance of only ~ 2.5 kpc, based on the measured free electron column density of 127 pc/cc and the electron distribution model of Cordes & Lazio, this may be, after the Crab, the nearest very young pulsar known. The pulsar is located near the radio supernova remnant candidate G309.8-2.6
Comprehensive comparative outcomes in children with congenital heart disease: The rationale for the Congenital Catheterization Research Collaborative
Clinical research in the treatment of patients with congenital heart disease (CHD) is limited by the wide variety of CHD manifestations and therapeutic options as well as the generally low incidence of CHD. The availability of comprehensive, contemporary outcomes studies is therefore limited. This inadequacy may result in a lack of data‐driven medical decision making. In 2013, clinician scientists at two centers began a research collaboration, the Congenital Catheterization Research Collaborative (CCRC). Over time, the CCRC has grown to include nine cardiac centers from across the United States, with a common data coordinating center. The CCRC seeks to generate high‐quality, contemporary, statistically robust, and generalizable outcomes research which can help address important clinical questions in the treatment of CHD. To date, the CCRC has reported on multicenter outcomes in: neonates with congenital aortic stenosis, infants undergoing right ventricular decompression for pulmonary atresia and intact ventricular septum, and infants with ductal‐dependent pulmonary blood flow. The CCRC has been successful at leveraging large multicenter cohorts of patients in a contemporary period to perform comparative studies. In the future, the CCRC plans to continue to perform hypothesis‐driven retrospective and prospective observational studies of CHD populations where controversy exists or where novel interventions or therapies have emerged. Quality improvement efforts including lesion‐specific registry development may be an additional potential future target.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149494/1/chd12737.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149494/2/chd12737_am.pd
The mysteries of mammatus clouds: Observations and formation mechanisms
Mammatus clouds are an intriguing enigma of atmospheric fluid dynamics and cloud physics. Most commonly observed on the underside of cumulonimbus anvils, mammatus also occur on the underside of cirrus, cirrocumulus, altocumulus, altostratus, and stratocumulus, as well as in contrails from jet aircraft and pyrocumulus ash clouds from volcanic eruptions. Despite their aesthetic appearance, mammatus have been the subject of few quantitative research studies. Observations of mammatus have been obtained largely through serendipitous opportunities with a single observing system (e.g., aircraft penetrations, visual observations, lidar, radar) or tangential observations from field programs with other objectives. Theories describing mammatus remain untested, as adequate measurements for validation do not exist because of the small distance scales and short time scales of mammatus. Modeling studies of mammatus are virtually nonexistent. As a result, relatively little is known about the environment, formation mechanisms, properties, microphysics, and dynamics of mammatus. This paper presents a review of mammatus clouds that addresses these mysteries. Previous observations of mammatus and proposed formation mechanisms are discussed. These hypothesized mechanisms are anvil subsidence, subcloud evaporation/sublimation, melting, hydrometeor fallout, cloud-base detrainment instability, radiative effects, gravity waves, Kelvin-Helmholtz instability, Rayleigh-Taylor instability, and Rayleigh-Bénard-like convection. Other issues addressed in this paper include whether mammatus are composed of ice or liquid water hydrometeors, why mammatus are smooth, what controls the temporal and spatial scales and organization of individual mammatus lobes, and what are the properties of volcanic ash clouds that produce mammatus? The similarities and differences between mammatus, virga, stalactites, and reticular clouds are also discussed. Finally, because much still remains to be learned, research opportunities are described for using mammatus as a window into the microphysical, turbulent, and dynamical processes occurring on the underside of clouds. © 2006 American Meteorological Society
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