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At least 469 records · Page 26Linked to original sources
PubMed1990

Little influence on tooth position from playing a wind instrument.

The morphology of the face and dentition of 62 adult professional wind instrument musicians was recorded with roentgencephalometry and dental casts. The musician group was comprised of 31 brass instrument players, and 31 reed instrument or flute players. The results were compared between the two subgroups and between these and a control group. The few differences found between groups were small. Overbite and upper dental arch width at the canines were smaller in the musicians than in the control group. Width at the maxillary and mandibular molars was somewhat smaller in the reed instrument and flute players than in the control group. No difference in overjet was found. Cephalometric analysis showed similar, normal facial morphology in all groups. The range of variables recorded was large in all groups.

Adolescent↗
PubMed1999

Stimulus-function, wind-up and modulation by diffuse noxious inhibitory controls of responses of convergent neurons of the spinal trigeminal nucleus oralis.

Extracellular unitary recordings were made from 53 spinal trigeminal nucleus oralis (Sp5O) convergent neurons in halothane-anaesthetized rats. The neurons had an ipsilateral receptive field including mainly oral or perioral regions. They responded to percutaneous electrical stimulation with two peaks of activation. The first had a short latency (4.3 +/- 0.3 ms) and low threshold (0.35 +/- 0.04 mA), whereas the second had a longer latency (68.1 +/- 3.4 ms) and higher threshold (7.3 +/- 0.5 mA). Intracutaneous injection of capsaicin (0.1%) produced a strong and rapid reduction of the long-latency responses of Sp5O convergent neurons with little effect on the short-latency responses. In most cases (73%), the long-latency responses exhibited a wind-up phenomenon during repetitive (0.66 Hz) suprathreshold electrical stimulation. These results suggest that C-fibres mediate the long-latency response of Sp5O convergent neurons. Regarding the C-fibre-evoked responses, a linear relationship between the intensity of the applied current and the magnitude of the response was found within the one to three times threshold range. The Sp5O convergent neurons also encoded the intensity of mechanical stimuli applied to the skin or mucosa in the 5-50 g ranges. The evoked activity of Sp5O convergent neurons could be suppressed by noxious heat applied to the tail (52 degrees C) and long-lasting poststimulus effects followed this. These findings show that convergent neurons in the Sp5O resemble those in the deep laminae of the spinal dorsal horn and spinal trigeminal nucleus caudalis, and further support that the Sp5O plays a part in the processing of nociceptive information from the orofacial region.

Action Potentials↗
PubMed1990

Prediction of oxygen uptake on a bicycle wind-loaded simulator.

The primary purpose of this study was to determine the accuracy of estimating oxygen uptake (VO2) from the flywheel revolution rate of a bicycle wind-loaded simulator. VO2 at four different flywheel revolution rates was measured on a Findlay Road Machine (FRM). Ten male trained cyclists, 10 male untrained cyclists, 10 female trained cyclists and 10 female untrained cyclists served as subjects. Significant curvilinear relationships (P less than 0.01) were found between road speed estimated from flywheel revolution rate and VO2 expressed as 1.min-1, ml.kg-1.min-1, 1.min-1.m-2 (r = 0.97, 0.96, 0.98, respectively). The absolute standard error of the mean VO2 was 0.21 l.min-1 (9.6%), 3.71 ml.kg-1.min-1 (11.5%) and 0.10 l.min-1.m-2 (7.9%), respectively. The relationship between VO2 and speed was similar to that reported during road cycling. To determine the magnitude of between-machine differences in VO2, six subjects randomly performed cycling using two different FMR. Significant (P less than 0.05) differences between machines were found at only the highest speed. The present study indicates that it is possible to accurately predict VO2 from flywheel revolution rate using a FRM. Since the FRM appears to approximate the resistance a cyclist experiences on the road and allows cyclists to use their own bicycle, it provides a good alternative to traditional laboratory ergometers.

Bicycling↗
PubMed1992

Winding number formula for Maslov indices.

A formula for the Maslov index of closed curves on Lagrangian manifolds is derived. The index is expressed as the number of times the plane tangent to the curve winds around it. Applications include unstable periodic orbits, in which case the Lagrangian manifolds are the stable or unstable manifolds of the orbits, and cycles on the invariant tori of integrable systems, in which case the manifolds are the tori themselves.

Journal Article↗
PubMed1994

Characteristic zonal winds and long-lived vortices in the atmospheres of the outer planets.

The cameras on board the NASA Voyager spacecraft provided a survey of cloud systems within the atmospheres of the giant planets and allowed determination of zonal wind patterns, which constrain long-lived cloud systems. The basic atmospheric circulations are compared and long-lived cloud features are reviewed. The basic structure of the Great Red Spot is reviewed and the tendency of the spot to drift at -4 m s(-1) or -2 m s(-1) is presented.

Journal Article↗
PubMed1994

Fractal structure of large-scale variability of wind-driven waves according to laser-scanning data.

Results are presented for experimental laser-scanning investigations of the statistical characteristics of wind-driven ocean waves. The method involves counting the number of specular points during scanning of the sea surface by a narrow laser beam on a moving ship. The data analyzed are the set of specular points recorded along a track traced out by the laser beam as a result of the motion of the ship and the scanning beam. A prominent feature is the large-scale variability of the number of specular points and the self-similar nature of the process over a rather wide range of spatial scales. A fractal analysis of the process shows a clear power-law interval in the spatial spectrum of the distribution of specular points.

Journal Article↗
PubMed2004

Pollen limitation causes an Allee effect in a wind-pollinated invasive grass (Spartina alterniflora).

It is usually assumed that pollen availability does not limit reproduction in wind-pollinated plants. Little evidence either supporting or contradicting this assumption exists, despite the importance of seed production to population persistence and growth. We investigated the role of pollen limitation in an invasive estuarine grass (Spartina alterniflora), with a manipulative pollen supplementation and exclusion experiment in areas of high population density and at the low-density leading edge of the invasion. We also quantified pollen deposition rates on stigmas and pollen traps along a windward to leeward gradient. We found pollen impoverishment at the low-density leading edge of a large invasion, causing an 8-fold reduction in seed set. We found 9-fold more pollen on stigmas of high-density plants than on those of low-density plants. Pollen deposition rates on stigmas and traps did not increase downwind of low-density plants but did increase downwind of high-density plants and dropped off precipitously across a gap that lacked pollen donors. The delay of appreciable numbers of seed caused by pollen limitation persists for decades until vegetative growth coalesces plants into continuous meadows, and this Allee effect has slowed the rate of spread of the invasion.

Ecosystem↗
PubMed1980

Gaseous isotope separation using solar wind phenomena.

A large evacuated drum-like chamber fitted with supersonic nozzles in the center, with the chamber and the nozzles corotating, can separate gaseous fluids according to their molecular weights. The principle of separation is essentially the same as that of the solar wind propagation, in which components of the plasma fluid are separated due to their difference in the time-of-flight. The process can inherently be very efficient, serving as a pump as well as a separator, and producing well over 10(5) separative work units (kg/year) for the hydrogen/deuterium mixture at high-velocity flows.

Journal Article↗
PubMed2004

Venlafaxine-induced depression of wind-up activity in mononeuropathic rats is potentiated by inhibition of brain 5-HT1A receptor expression in vivo.

Antinociceptive effects of inhibiting 5-HT1A receptor expression by intracerebroventricular administration of an antisense oligodeoxynucleotide were studied in mononeuropathic rats. A 7-day period of treatment with the antisense produced: (i) reduction of mechanical hyperalgesia in the neuropathic hindlimb starting from day 5 of treatment, (ii) decrease of the hypothermic effect of 8-OH-DPAT challenge on day 6 of treatment, and (iii) potentiation of the inhibitory effect of velafaxine on spinal wind-up activity on day 7 of treatment. Results suggest a counteracting role of somatodendritic 5-HT1A receptors of raphe nuclei neurons in the antinociceptive efficacy of antidepressants with serotonergic spectrum in neuropathic pain.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2001

A comparison of tailpipe, dilution tunnel, and wind tunnel data in measuring motor vehicle PM.

Comparison between particle size distributions recorded directly at the tailpipes of both diesel and gasoline vehicles and measurements made using a conventional dilution tunnel reveals two problems incurred when using the latter method for studying particle number emissions. One is the potential for particulate matter (PM) artifacts originating from hydrocarbon material stored in the transfer hose connecting the tailpipe to the dilution tunnel, and the other is the particle coagulation (as well as condensation and chemical changes) that occurs during the transport. Both are potentially generic to current PM emissions measurement practices. The artifacts typically occur as a nanoparticle mode (10-30 nm) that is 2-4 orders of magnitude larger than what is present in the vehicle exhaust and can easily be mistaken for a similar mode that can arise from the nucleation of hydrocarbon or SO4(2-) components in the exhaust under appropriate dilution rates. Wind tunnel measurements are in good agreement with those made directly from the tailpipe and substantiate the potential for artifacts. They reveal PM levels for the recent model port fuel injection (PFI) gasoline vehicles tested that are small compared with the ambient background particle level during steady-state driving. The PM emissions recorded for drive cycles such as the Federal Test Procedure (FTP) and US06 occur primarily during acceleration, as has been previously noted. Light-duty diesel vehicle emissions normally exhibit a single lognormal mode centered between 55 and 80 nm, although a nonartifact nanoparticle mode in some cases appears at a 70-mph cruise up a grade.

Air Movements↗
PubMed2000

High-Resolution Spectroscopy of the X-Ray-photoionized Wind in Cygnus X-3 with the Chandra High-Energy Transmission Grating Spectrometer.

We present a preliminary analysis of the 1-10 keV spectrum of the massive X-ray binary Cygnus X-3, obtained with the high-energy transmission grating spectrometer on the Chandra X-Ray Observatory. The source reveals a richly detailed discrete emission spectrum, with clear signatures of photoionization-driven excitation. Among the spectroscopic novelties in the data are the first astrophysical detections of a number of He-like "triplets" (Si, S, Ar) with emission-line ratios characteristic of photoionization equilibrium, fully resolved narrow radiative recombination continua of Mg, Si, and S, the presence of the H-like Fe Balmer series, and a clear detection of an approximately 800 km s-1 large-scale velocity field as well as an approximately 1500 km s-1 FWHM Doppler broadening in the source. We briefly touch on the implications of these findings for the structure of the Wolf-Rayet wind.

Journal Article↗
PubMed2000

Measurement of Charge Exchange and X-Ray Emission Cross Sections for Solar Wind-Comet Interactions.

X-ray emission from a comet was observed for the first time in 1996. One of the mechanisms believed to be contributing to this surprisingly strong emission is the interaction of highly charged solar wind ions with cometary gases. Reported herein are total absolute charge-exchange and normalized line-emission (X-ray) cross sections for collisions of high-charge state (+3 to +10) C, N, O, and Ne ions with the cometary species H2O and CO2. It is found that in several cases the double charge-exchange cross sections can be large, and in the case of C3+ they are equal to those for single charge exchange. Present results are compared to cross section values used in recent comet models. The importance of applying accurate cross sections, including double charge exchange, to obtain absolute line-emission intensities is emphasized.

Journal Article↗
PubMed2000

Ultra-High-Energy Cosmic Rays from Young Neutron Star Winds.

The long-held notion that the highest energy cosmic rays are of distant extragalactic origin is challenged by observations that events above approximately 1020 eV do not exhibit the expected high-energy cutoff from photopion production off the cosmic microwave background. We suggest that these unexpected ultra-high-energy events are due to iron nuclei accelerated from young strongly magnetized neutron stars through relativistic MHD winds. We find that neutron stars whose initial spin periods are shorter than approximately 10 ms and whose surface magnetic fields are in the 1012-1014 G range can accelerate iron cosmic rays to greater than approximately 1020 eV. These ions can pass through the remnant of the supernova explosion that produced the neutron star without suffering significant spallation reactions or energy loss. For plausible models of the Galactic magnetic field, the trajectories of the iron ions curve sufficiently to be consistent with the observed, largely isotropic arrival directions of the highest energy events.

Journal Article↗
PubMed2005

Wind, rain, flooding, and fear: coordinating military public health in the aftermath of Hurricane Katrina.

On 29 August 2005, a category 4 hurricane struck the Gulf Coast of Mississippi and southeast Louisiana, resulting in widespread destruction caused by winds in excess of 190 km/h (120 miles/h), heavy rain, and flooding. Communication, electricity, and fresh water supplies were disrupted throughout the region, rendering much of the area uninhabitable. Despite tremendous obstacles, the US military spearheaded the eventually successful rescue, recovery, and relief operations. This article describes the challenges of protecting the health and safety of these personnel in the immediate aftermath of Hurricane Katrina.

Disasters↗
PubMed2006

Flowering phenology and wind-pollination efficacy of heterodichogamous Juglans mandshurica (Juglandaceae).

BACKGROUND AND AIMS: Heterodichogamy differs from normal dichogamy, in that it involves two mating types (protogyny and protandry) that occur at a 1 : 1 ratio in a population. Flowering phases of the two mating types are synchronized and reciprocal, which was considered to ensure between-type outcrossing. This study aims to quantify the flowering pattern and pollination efficacy in Juglans mandshurica, a wind-pollinated heterodichogamous tree. METHODS: The pattern of flowering phenology was monitored within individual trees and pollen traps were used to measure air-borne pollen loads during the spring in 2003 and 2004. Pollen longevity was determined by staining technique. Also a pollen supplementation experiment was performed in 2004 to assess pollen limitation of fruit production. KEY RESULTS: There was no overlap between sexual functions within individual trees. Flowering periods of the two mating types were reciprocal and synchronous in both 2003 and 2004. Air-borne pollen loads were large, and protogynous and protandrous individuals each produced a high pollination peak, consistent with the two blooming periods. Maximum pollen longevity was about 4 h for protandrous individuals, and 3 h for protogynous individuals. Pollen supplementation did not increase fruit production in either protogynous or protandrous individuals. CONCLUSIONS: Heterodichogamous flowering in Juglans mandshurica effectively avoids selfing, promotes between-type outcrossing, and leads to efficient pollination in a natural population.

Breeding↗
PubMed1996

Large genetic change at small fitness cost in large populations of Drosophila melanogaster selected for wind tunnel flight: rethinking fitness surfaces.

The fitness effects of extreme genetic change by selection were studied in large populations subjected to prolonged, intense selection. Two replicate populations of Drosophila melanogaster, with estimated effective sizes 500 < or = Ne < or = 1000, were selected for increased performance in a wind tunnel, selecting on average the fastest 4.5% of flies. The mean apparent flying speed of both lines increased from approximately 2 to 170 cm/sec and continued to respond at diminishing rates, without reaching a plateau, for 100 generations. Competitive fitness tests in generations 50 and 85 showed minimal or no fitness loss in selected lines compared to controls. Sublines relaxed in generations 65 and 85 showed minimal or no regression in apparent flying speed. Hybrid lines, from a cross of selected x control lines in generation 75, responded to reselection saltationally, showing that the chromosomes of the selected lines had been assembled from alleles at many loci, from many different chromosomes in the base population. Thus, major genetic change was achieved, but without the costs usually associated with strong directional selection. Large population size has been interpreted, in opposing models, as either a brake or an accelerator in its effects on long-term change by selection. These results favor the second model, and challenge the concept of rugged fitness surfaces underlying the first model.

Animals↗
PubMed1993

Shoot dynamics of Pinus pumila in relation to altitudinal and wind exposure gradients on the Kiso mountain range, central Japan.

Seasonal shoot dynamics of Japanese mountain stone pine (Pinus pumila Regel.) growing at six sites with different altitudes and slope aspects on the Kiso mountain range in central Japan were investigated. The shoots followed a similar growth pattern at all sites; current shoots elongated rapidly during June and July, and the current needles grew during July and August. Final lengths of the current shoots and needles decreased with increasing altitude. Current-shoot lengths were also shorter at the windward sites than at the leeward sites. At all sites, leaf senescence occurred intensively between mid-August and mid-September. Needle longevity, i.e., the age of the oldest living needle attached to a shoot, increased with increasing altitude. Fascicle density, i.e., the number of current needle fascicles on a unit shoot length, was greater at higher altitudes and windward sites than at lower altitudes and leeward sites. Seasonal dynamics of the P. pumila shoots were characterized by simultaneous replacement of old needles with new needles in the early autumn, thus avoiding any loss of canopy photosynthetic production during the growing season. Increases in needle longevity and fascicle density were associated with declining air temperature and increasing wind exposure. Needle longevity and fascicle density were characteristics of adaptive plasticity in P. pumila that prevent a reduction in growth potential in the stressful conditions of alpine regions.

Journal Article↗
PubMed1985

A single fatal penetrating chest wound from shattered wind-blown glass.

The great majority of penetrating wounds of the thorax result from firearms and bladed weapons. Penetrating wounds of the heart and of the great vessels still have a high immediate mortality. While penetrating chest wounds occasionally result from fragments of glass; most severe and fatal wounds from glass result from one's falling into or through architectural (plate) glass, sustaining wounds of abdomen or extremities, or both. A single, fatal penetrating chest wound resulting from a wind-blown fragment of glass is distinctly uncommon. The unique case of this type reported herein is that of a 12-year-old youth who was struck in his home in the left anterior chest by a single, sharp, slender fragment of glass blown from a window which shattered in a thunderstorm. This resulted in a rapidly fatal penetrating wound involving thoracic viscera. The forensic pathologist must thoroughly investigate and document such accidental deaths, modifying his/her autopsy procedure as necessary for these purposes and to avoid accidental injury at the autopsy table.

Child↗