Iowa State University

About: Iowa State University is a education organization based out in Ames, Iowa, United States. It is known for research contribution in the topics: Population & Gene. The organization has 50151 authors who have published 107716 publications receiving 3355909 citations. The organization is also known as: Iowa State University of Science and Technology & Iowa State College.

Exercise does not feel the same when you are overweight: the impact of self-selected and imposed intensity on affect and exertion

Abstract: Objective: The lower rates of adherence to physical activity commonly found among overweight adults compared to their normal-weight counterparts might be due to the activity being experienced as more laborious and less pleasant, particularly when its intensity is prescribed (or imposed) rather than self-selected. Design: Within-subject design, with two 20-min sessions of treadmill exercise, one at self-selected speed and one at imposed speed, 10% higher than the self-selected. Subjects: A total of 16 overweight (BMI: 31 kg/m 2 ) and 9 normal-weight (BMI: 22 kg/m 2 ) previously sedentary but healthy women (age: 43 years). Measurements: Heart rate, oxygen uptake relative to body weight, and ratings of perceived exertion and pleasure–displeasure were assessed every 5 min. Results: The overweight women showed higher oxygen uptake and perceived exertion than the normal-weight women during both sessions. Although the two groups did not differ in ratings of pleasure–displeasure during the session at self-selected speed, only the overweight women showed a significant decline when the speed was imposed. Conclusions: Imposing a speed that is just 10% higher than what overweight women would have self-selected led to a significant decline in reported pleasure. Over time, this could diminish the enjoyment of and intrinsic motivation for physical activity, reducing adherence. International Journal of Obesity (2006) 30, 652–660. doi:10.1038/sj.ijo.0803052; published online 30 August 2005

Ionic Liquids as Matrixes for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Abstract: Room-temperature ionic liquids are useful as solvents for organic synthesis, electrochemical studies, and separations. We wished to examine whether their high solubalizing power, negligible vapor pressure, and broad liquid temperature range are advantageous if they are used as matrixes for UV-MALDI. Several different ionic matrixes were synthesized and tested, using peptides, proteins, and poly(ethylene glycol) (PEG-2000). All ionic liquids tested have excellent solubilizing properties and vacuum stability compared to other commonly used liquid and solid matrixes. However, they varied widely in their ability to produce analyte gas-phase ions. Certain ionic matrixes, however, produce homogeneous solutions of greater vacuum stability, higher ion peak intensity, and equivalent or lower detection limits than currently used solid matrixes. Clearly, ionic liquids and their more amorphous solid analogues merit further investigation as MALDI matrixes.

Regional Dynamical Downscaling and the CORDEX Initiative

Abstract: We review the challenges and future perspectives of regional climate model (RCM), or dynamical downscaling, activities. Among the main technical issues in need of better understanding are those of selection and sensitivity to the model domain and resolution, techniques for providing lateral boundary conditions, and RCM internal variability. The added value (AV) obtained with the use of RCMs remains a central issue, which needs more rigorous and comprehensive analysis strategies. Within the context of regional climate projections, large ensembles of simulations are needed to better understand the models and characterize uncertainties. This has provided an impetus for the development of the Coordinated Regional Downscaling Experiment (CORDEX), the first international program offering a common protocol for downscaling experiments, and we discuss how CORDEX can address the key scientific challenges in downscaling research. Among the main future developments in RCM research, we highlight the development of cou...

Histochemical and enzymatic comparison of the gastrocnemius muscle of young and elderly men and women.

Abstract: To examine the effects of aging on human skeletal muscle, 10 men and 10 women, 64 +/- 1 yr old (Mean +/- SE), and 10 men and 10 women, 24 +/- 1 yr old, were studied. All subjects were sedentary nonsmokers who were carefully screened for latent cardiovascular, metabolic, or musculoskeletal disease. Needle biopsy samples were obtained from the lateral gastrocnemius muscle and examined using histochemical and biochemical techniques. The percentage of Type I, Type IIa, and Type IIb fibers did not differ with age. However, Type I fibers occupied a larger percent of total muscle area in the older men and women (60.6 +/- 2.6 vs 53.6 +/- 2.0%; p less than .05), because Type IIa and Type IIb fibers were 13-31% smaller (p less than .001) in these subjects. Muscle capillarization and mitochondrial enzyme (i.e., succinate dehydrogenase, citrate synthase, and beta-hydroxyacyl-CoA dehydrogenase) activities were also approximately 25% lower (p less than .001-.05) in the old subjects. Although it is difficult to determine whether these differences are due to aging itself or are simply due to inactivity, these structural and biochemical changes probably contribute to the decreases in muscle mass, strength, and endurance often observed in healthy but sedentary older men and women.