Growth hormone and muscle function responses to skeletal muscle ischemia.

We examined the effects of ischemia (ISC) alone and with low-intensity exercise (ISC+EX) on growth hormone (GH) and muscle function responses. Nine men (22 +/- 0.7 yr) completed 3 study days: an ISC day (thigh cuff inflated five times, 5 min on, 3 min off), an ISC+EX day [knee extension at 20% maximal voluntary contraction (MVC) with ISC], and a control day.

Diabetes care in the San Francisco County Jail.

Chronic disease management is becoming increasingly important in correctional settings, especially diabetes. We conducted a retrospective chart review of diabetic inmates in San Francisco County Jail and examined the sociodemographic characteristics, markers of disease status, and compliance with jail-specific care guidelines within this setting. We found high rates of compliance with immediate-term care guidelines (e.

Spitzer spectral observations of the deep impact ejecta.

Spitzer Space Telescope imaging spectrometer observations of comet 9P/Tempel 1 during the Deep Impact encounter returned detailed, highly structured, 5- to 35-micrometer spectra of the ejecta. Emission signatures due to amorphous and crystalline silicates, amorphous carbon, carbonates, phyllosilicates, polycyclic aromatic hydrocarbons, water gas and ice, and sulfides were found. Good agreement is seen between the ejecta spectra and the material emitted from comet C/1995 O1 (Hale-Bopp) and the circumstellar material around the young stellar object HD100546.

Adaptations in human neuromuscular function following prolonged unweighting: I. Skeletal muscle contractile properties and applied ischemia efficacy.

Strength loss following disuse may result from alterations in muscle and/or neurological properties. In this paper, we report our findings on human plantar flexor muscle properties following 4 wk of limb suspension (unilateral lower limb suspension), along with the effect of applied ischemia (Isc) on these properties. In the companion paper (Part II), we report our findings on the changes in neurological properties.

Adaptations in human neuromuscular function following prolonged unweighting: II. Neurological properties and motor imagery efficacy.

Strength loss following disuse may result from alterations in muscle and/or neurological properties. In this paper, we report our findings on human plantar flexor neurological properties following 4 wk of limb suspension [unilateral lower limb suspension (ULLS)], along with the effect of motor imagery (MI) training on these properties. In the companion paper (Part I), we report our findings on the changes in skeletal muscle properties.

Reliability of techniques to assess human neuromuscular function in vivo.

The purpose of this study was to comprehensively evaluate the reliability of a large number of commonly utilized experimental tests of in vivo human neuromuscular function separated by 4-weeks. Numerous electrophysiological parameters (i.e.

A soft solid surface on Titan as revealed by the Huygens Surface Science Package.

The surface of Saturn's largest satellite--Titan--is largely obscured by an optically thick atmospheric haze, and so its nature has been the subject of considerable speculation and discussion. The Huygens probe entered Titan's atmosphere on 14 January 2005 and descended to the surface using a parachute system. Here we report measurements made just above and on the surface of Titan by the Huygens Surface Science Package.

The use of magnetic resonance imaging to evaluate lumbar muscle activity during trunk extension exercise at varying intensities.

Study Design: Descriptive, repeated measures analysis of exercise-induced changes in lumbar muscle transverse relaxation time (T2).

Objectives: To use muscle functional magnetic resonance imaging (MRI) to characterize the activity levels and recruitment patterns of the lumbar extensor muscles during trunk extension exercise over 3 intensities.

Summary Of Background Data: Contrast shifts in T2 are indicative of skeletal muscle activity during resistance exercise and are used to characterize the function of a variety of muscles.

Resistance and functional training reduces knee extensor position fluctuations in functionally limited older adults.

The purpose of this study was to determine the effect of task-specificity on knee extensor steadiness adaptations in functionally limited older adults. Twenty-four functionally limited older adults (74.6+/-7.

Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater.

Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and windblown 'global' dust.

An integrated view of the chemistry and mineralogy of martian soils.

The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could reflect either a global component or the general similarity in the compositions of the rocks from which they were derived.

Sex differences in muscle fatigability and activation patterns of the human quadriceps femoris.

The purposes of this study were to determine if the fatigability of the quadriceps femoris varies by biological sex under conditions of normal muscle blood flow and ischemia, and if differences in neuromuscular activation patterns exist. Young men and women (n = 11/group; age 20-39 years) performed a sustained knee extension contraction at 25% of maximal force under conditions of occluded (OCC) and normal muscle blood flow (NON-OCC). Electromyographic (EMG) activity was recorded from the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM) and biceps femoris (BF) muscles, and analyzed for fatigue-induced changes in the amplitude and burst rate and duration (transient changes in motor unit recruitment) of the signal.

Chemistry of rocks and soils at Meridiani Planum from the Alpha Particle X-ray Spectrometer.

The Alpha Particle X-ray Spectrometer on the Opportunity rover determined major and minor elements of soils and rocks in Meridiani Planum. Chemical compositions differentiate between basaltic rocks, evaporite-rich rocks, basaltic soils, and hematite-rich soils. Although soils are compositionally similar to those at previous landing sites, differences in iron and some minor element concentrations signify the addition of local components.

Soils of Eagle crater and Meridiani Planum at the Opportunity Rover landing site.

The soils at the Opportunity site are fine-grained basaltic sands mixed with dust and sulfate-rich outcrop debris. Hematite is concentrated in spherules eroded from the strata. Ongoing saltation exhumes the spherules and their fragments, concentrating them at the surface.

In situ evidence for an ancient aqueous environment at Meridiani Planum, Mars.

Sedimentary rocks at Eagle crater in Meridiani Planum are composed of fine-grained siliciclastic materials derived from weathering of basaltic rocks, sulfate minerals (including magnesium sulfate and jarosite) that constitute several tens of percent of the rock by weight, and hematite. Cross-stratification observed in rock outcrops indicates eolian and aqueous transport. Diagenetic features include hematite-rich concretions and crystal-mold vugs.

The Opportunity Rover's Athena science investigation at Meridiani Planum, Mars.

The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common.

Leg muscle activity during walking with assistive devices at varying levels of weight bearing.

Objective: To evaluate the muscle activation patterns at varying levels of weight-bearing forces during assisted walking with an axillary crutch and a recently designed device that allows weight transfer through the pelvic girdle (ED Walker).

Design: Descriptive, repeated measures.

Setting: University-based research laboratory.

Basaltic rocks analyzed by the Spirit Rover in Gusev Crater.

The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins.

Chemistry of rocks and soils in Gusev Crater from the alpha particle x-ray spectrometer.

The alpha particle x-ray spectrometer on the Spirit rover determined major and minor elements of soils and rocks in Gusev crater in order to unravel the crustal evolution of planet Mars. The composition of soils is similar to those at previous landing sites, as a result of global mixing and distribution by dust storms. Rocks (fresh surfaces exposed by the rock abrasion tool) resemble volcanic rocks of primitive basaltic composition with low intrinsic potassium contents.

The Spirit Rover's Athena science investigation at Gusev Crater, Mars.

The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport.

Dust measurements in the coma of comet 81P/Wild 2 by the Dust Flux Monitor Instrument.

We present measurements of the dust particle flux and mass distribution from the Stardust Dust Flux Monitor Instrument (DFMI) throughout the flyby of comet 81P/Wild 2. In the particle mass regime from 10(-14) to 10(-7) kilograms, the spacecraft encountered regions of intense swarms of particles, together with bursts of activity corresponding to clouds of particles only a few hundred meters across. This fine-scale structure can be explained by particle fragmentation.

The Cometary and Interstellar Dust Analyzer at comet 81P/Wild 2.

The CIDA (Cometary and Interstellar Dust Analyzer) instrument on the Stardust spacecraft is a time-of-flight mass spectrometer used to analyze ions formed when fast dust particles strike the instrument's target. In the spectra of 45 presumably interstellar particles, quinone derivates were identified as constituents in the organic component. The 29 spectra obtained during the flyby of Comet 81P/Wild 2 confirm the predominance of organic matter.

Surface of young Jupiter family comet 81P/Wild 2: view from the Stardust Spacecraft.

Images taken by the Stardust mission during its flyby of 81P/Wild 2 show the comet to be a 5-kilometer oblate body covered with remarkable topographic features, including unusual circular features that appear to be impact craters. The presence of high-angle slopes shows that the surface is cohesive and self-supporting. The comet does not appear to be a rubble pile, and its rounded shape is not directly consistent with the comet being a fragment of a larger body.

Gender differences in skeletal muscle fatigability are related to contraction type and EMG spectral compression.

The purposes of this study were 1) to evaluate gender differences in back extensor endurance capacity during isometric and isotonic muscular contractions, 2) to determine the relation between absolute load and endurance time, and 3) to compare men [n = 10, age 22.4 +/- 0.69 (SE) yr] and women (n = 10, age 21.

Derecruitment of the lumbar musculature with fatiguing trunk extension exercise.

Study Design: This was a descriptive study involving 20 healthy individuals.

Objectives: To evaluate the neuromuscular activation patterns of the lumbar paraspinal and hip extensor muscles during isotonic trunk extension exercise.

Summary Of Background Data: Few studies have evaluated the effect of muscle fatigue on the lumbar musculature during isotonic exercise.