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Biomedical subjects

L S Hughes

Publications and source records attributed to L S Hughes.

4 recordsLinked to original sources
PubMed2004

Strength and endurance training of an individual with left upper and lower limb amputations.

PURPOSE: The purpose of this article is to describe the development of a strength and endurance training programme designed to prepare an individual with a left glenohumeral disarticulation and transtibial amputation for a bike trip across the USA. METHOD: The subject was scheduled for training three times per week over a two-month period followed by two times per week for an additional two months. Training consisted of a resistance training circuit using variable resistance machines, cycling using a recumbent stationary bike, and core stability training using stability ball exercises. Changes in strength were assessed using 10 RM tests on the resistance machines and changes in peak VO(2) were monitored utilizing the Cosmed K4b pulmonary function tester. RESULTS: The subject demonstrated a 30.3% gain in peak VO(2). The subject's 10 RM for left single limb leg press increased 36.8% and gains of at least 7.7% were seen for all other muscle groups tested. CONCLUSION: The strength and endurance training programme adapted to compensate for this subject's limb losses was effective in increasing both strength and peak VO(2). Adapting exercise programmes to compensate for limb loss may allow individuals with amputations to participate in physically challenging activities that otherwise may not be available to them.

Adult↗
PubMed2001

Emissions of size-segregated aerosols from on-road vehicles in the Caldecott tunnel.

Particulate matter emissions from the California in-use vehicle fleet were measured as 37,500 vehicles traveled through two bores of the Caldecott Tunnel located in the San Francisco Bay area. Microorifice cascade impactors and filter-based samplers were used to determine the particle chemical composition as a function of particle size. Ammonia emissions from the vehicle fleet were measured as well. Concentrations of aerosol mass, organic carbon, elemental carbon, sulfate ion, nitrate ion, and ammonium ion, as well as 13 elements are reported. The particle mass distribution peaks in the particle size range 0.1-0.18 microm aerodynamic diameter (Da). Elemental carbon and organic matter were the largest components of particle mass in all the size ranges studied. The Caldecott Tunnel bores studied include one which carries light-duty vehicle traffic and one which carries a mixture of light- and heavy-duty vehicle traffic. From experiments conducted in both bores, estimates are made of the size distribution and chemical composition of particulate matter emissions extrapolated to the 100% light-duty and 100% heavy-duty vehicle fleets. The heavy-duty vehicle fleet emitted 1285 +/- 237 mg of fine particulate matter (Da < 1.9 microm)/kg of C contained in the fuel burned (corresponding to approximately 430 +/- 79 mg/km driven). Light-duty vehicles emitted less than 85 +/- 6 mg/kg of C in the fuel burned (corresponding to less than approximately 5.5 +/- 0.4 mg/km driven). Emissions of gas-phase ammonia in the Caldecott Tunnel were measured to be 194 and 267 mg/L of gasoline-equivalent fuel burned in the tunnel. The ammonia emissions are attributed to automobiles that were equipped with 3-way catalysts and operating fuel rich.

Aerosols↗
PubMed2001

Quantification of ATOFMS data by multivariate methods.

Aerosol time-of-flight mass spectrometry (ATOFMS) is capable of measuring the sizes and chemical compositions of individual polydisperse aerosol particles in real time. A qualitative estimate of the particle composition is acquired in the form of a mass spectrum that must be subsequently interpreted in order to draw conclusions regarding atmospheric relevance. The actual problem involves developing a calibration that allows the mass spectral data to be transformed into estimates of the composition of the atmospheric aerosol. A properly calibrated ATOFMS system should be able to quantitatively determine atmospheric concentrations of various species. Ideally, it would be able to accomplish this more rapidly, accurately, with higher size and time resolution, and at a far lower marginal cost than the manual sampling methods that are currently employed. Attempts have already been made at using ATOFMS and similar techniques to extract the bulk chemical species concentration present in an ensemble of particles. This study represents the use of a multivariate calibration method, two-dimensional partial least-squares analysis, for calibrating single-particle mass spectral data. The method presented here is far less labor-intensive than the univariate methods attempted to date and allows for less observer bias. Because of the labor savings, this is also the most comprehensive calibration performed to date, resulting in the quantification of 44 different chemical species.

Aerosols↗