University of Hawaii at Manoa

About: University of Hawaii at Manoa is a education organization based out in Honolulu, Hawaii, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 13693 authors who have published 25161 publications receiving 1023924 citations.

Isokinetic Hamstrings:Quadriceps Ratios in Intercollegiate Athletes.

Abstract: OBJECTIVE: To compare the differences in the concentric hamstrings:quadriceps (H:Q) ratio among athletes in different sports at 3 velocities. DESIGN AND SETTING: We measured the H:Q ratio of both knees using the Biodex Pro Isokinetic Device. SUBJECTS: Eighty-one male and female collegiate athletes. MEASUREMENTS: We performed analyses for sport, velocity, and side of body for each sex. To compare the means of the concentric H:Q ratios for mean peak torque and mean total work, a 2 x 3 x 4 mixed-factorial analysis of variance was computed for women and a 2 x 2 x 3 mixed-factorial analysis of variance was computed for men. RESULTS: We observed no significant interactions for men and women for the concentric H:Q ratio for mean peak torque. There was a significant mean difference among velocity conditions and a significant difference for men with respect to velocity. No significant differences were found for side of body or sport. CONCLUSIONS: The H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body.

Vortex Rossby waves in a numerically simulated tropical cyclone. Part I: Overall structure, potential vorticity, and kinetic energy budgets

Abstract: The asymmetric structure in the inner core of a numerically simulated tropical cyclone is analyzed in this study. The simulated tropical cyclone is found to be highly asymmetric in the inner core. In the mid–lower troposphere, the asymmetry in the core is dominated by azimuthal wavenumber-1 and wavenumber-2 vortex Rossby waves. These waves propagate azimuthally upwind against the azimuthal mean cyclonic tangential flow around the eyewall, and thus have a much longer cyclonic rotation period (by a factor of 2) than the period of a parcel moving with the cyclonic mean tangential flow around the circumference. They also propagate outward against the boundary layer inflow of the azimuthal mean cyclone. The waves are only visible within a radius of about 60 km from the cyclone center. Beyond this distance, the radial gradient of potential vorticity (PV) of the azimuthal mean cyclone is too weak to support the vortex Rossby waves. Although the divergent motion remains strong, the geopotential height an...

The Ontong Java Plateau

Abstract: The Alaska-size Ontong Java Plateau (OJP) in the southwest Pacific is the largest of the world's large igneous provinces and formed entirely in an oceanic environment. Limited sampling of the upper levels of basaltic basement reveals strongly bimodal ages of122 Ma and 90 Ma. Geochemical signatures indicate two isotopically distinct, ocean-island-like mantle-source types for the 122 Ma basalts and that the 90 Ma source was almost identical to one of the 122 Ma sources, strongly suggesting that a single mantle plume caused both eruptive events. In the 125-90 Ma period, the OJP appears to have been located near the Pacific Plate Euler poles and thus moved little relative to a postulated hotspot at about 42°S, 159°W; the early phase of emplacement probably also occurred near a spreading center, but substantial volumes were emplaced off-axis. The eastern lobe of the plateau appears to have been rifted shortly after 90 Ma. Incompatible and major element data are consistent with 20-30% polybaric partial melting of a peridotite source, beginning in the garnet stability field and continuing in the spinel field. Most existing basaltic basement samples appear to have experienced 30-45% of crystal fractionation; the resulting cumulates would be wehrlitic to pyroxenitic in composition, with an average density of 3.25 g cm -3 . We conclude that these cumulates form much of the plateau's high velocity (7.6 km s -1 ) basal crustal layer. The relatively high density of this layer appears to have prevented emergence of much of the OJP above sea level despite a total crustal thickness exceeding 30 km. Although the deepest levels of the crust could be eclogitized (further increasing density), post-emplacement subsidence of the plateau has probably been tempered by the presence of a roughly 85-km-thick melt-depleted mantle root with a relatively low density (<3.25 g cm -3 ) for mantle material. Estimates of partial melting deduced from the apparent thickness of the mantle root imply that the OJP formed by 17-31% partial melting, in excellent agreement with geochemical modeling.