Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

Controlled Experiments of Hillslope Coevolution at the Biosphere 2 Landscape Evolution Observatory: Toward Prediction of Coupled Hydrological, Biogeochemical, and Ecological Change

Understanding the process interactions and feedbacks among water, porous geological media, microbes, and vascular plants is crucial for improving predictions of the response of Earth’s critical zone to future climatic conditions. However, the integrated coevolution of landscapes under change is notoriously difficult to investigate. Laboratory studies are limited in spatial and temporal scale, while field studies lack observational density and control. To bridge the gap between controlled laboratory and uncontrollable field studies, the University of Arizona built a macrocosm experiment of unprecedented scale: the Landscape Evolution Observatory (LEO). LEO comprises three replicated, heavily instrumented, hillslope-scale model landscapes within the environmentally controlled Biosphere 2 facility. The model landscapes were designed to initially be simple and purely abiotic, enabling scientists to observe each step in the landscapes’ evolution as they undergo physical, chemical, and biological changes over many years. This chapter describes the model systems and associated research facilities and illustrates how LEO allows for tracking of multiscale matter and energy fluxes at a level of detail impossible in field experiments. Initial sensor, sampler, and soil coring data are already providing insights into the tight linkages between water flow, weathering, and microbial community development. These interacting processes are anticipated to drive the model systems to increasingly complex states and will be impacted by the introduction of vascular plants and changes in climatic regimes over the years to come. By intensively monitoring the evolutionary trajectory, integrating data with mathematical models, and fostering community-wide collaborations, we envision that emergent landscape structures and functions can be linked, and significant progress can be made toward predicting the coupled hydro-biogeochemical and ecological responses to global change

Lignin and starch as potential inductors for biodegradation of films based on poly(vinyl alcohol) and protein hydrolysate

Cílem práce bylo studium biodegradace polymerních filmů PVA/bílkovinný hydrolyzát obsahující induktory biodegradace typu škrob a lignin pro zvýšení rychlosti biologického rozkladu samotného PVA při zachování nebo zlepšení technicko-uživatelských vlastností blendů.The objective of this work was to study the biodegradation of blow-moulded films of PVA/protein hydrolysate which contain biodegradation inductors of the starch and lignin types. These increase the biodegradation rate of PVA while preserving or improving the technical and usage properties of blends

Biodegradability and Mechanical Properties of Poly(vinyl alcohol)-Based Blend Plastics Prepared Through Extrusion Method

Plastic blend materials consisting of poly(vinyl alcohol), glycerol and xanthan or gellan were prepared through laboratory extrusion. Their base mechanical properties were compared with the properties of poly(vinyl alcohol) foil and their biodegradability in soil, compost and both activated and anaerobic sludge were assessed. In samples with lower polysaccharide content (10-21 %w/w) the tensile strength of 15-20 MPa was found; the elongation at break of all blends was relatively close to the parameter of poly(vinyl alcohol) foil. The biodegradability levels of the blends tested corresponded to the content of natural components, and the mineralization of the samples with the highest carbohydrate proportion (42 %) reached 50-78 %, depending on the type of the environment. Complete biodegradation of all samples occurred in activated sludge. © 2012 Springer Science+Business Media, LLC

Uncovering the hillslope scale flow and transport dynamics in an experimental hydrologic system

12 month embargo; first published: 18 August 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Influence of various starch types on PCL/starch blends anaerobic biodegradation

Research concentrated on the biodegradable capability of PCL blends with various types of starch in an anaerobic aqueous environment of mesophilic sludge from a municipal wastewater treatment plant. For blend preparation, use was made of a native starch Meritena from maize, another from Waxy - a genetically modified type of maize, as well as Gel Instant, a gelatinized starch, and an amaranth starch. Additional PCL/starch blends were prepared from the same starch types, but these were initially plasticized with glycerol. The biodegradability tests were supplemented with thermo gravimetric analysis (TGA), and differential scanning calorimetry (DSC); morphology was identified using scanning electron microscopy (SEM), plus mechanical properties were also tested. While mixtures of PCL with starches plasticized with glycerol exhibited improved mechanical properties and a higher degree of biodegradation in the anaerobic environment, mixtures of PCL with pure forms of starch were ascertained as rather resistant to the anaerobic aqueous environment. TGA and DSC analysis confirmed the removal of starch and glycerol from the PCL matrix. SEM then proved these results through the absence of starch grains in the samples following anaerobic biodegradation. © 2013 Elsevier Ltd. All rights reserved

Highly sampled measurements in a controlled atmosphere at the Biosphere 2 Landscape Evolution Observatory

Land-atmosphere interactions at different temporal and spatial scales are important for our understanding of the Earth system and its modeling. The Landscape Evolution Observatory (LEO) at Biosphere 2, managed by the University of Arizona, hosts three nearly identical artificial bare-soil hillslopes with dimensions of 11x30 m(2) (1m depth) in a controlled and highly monitored environment within three large greenhouses. These facilities provide a unique opportunity to explore these interactions. The dataset presented here is a subset of the measurements in each LEO's hillslopes, from 1 July 2015 to 30 June 2019 every 15minutes, consisting of temperature, water content and heat flux of the soil (at 5cm depth) for 12 co-located points; temperature, relative humidity and wind speed above ground at 5 locations and 5 different heights ranging from 0.25m to 9-10m; 3D wind at 1 location; the four components of radiation at 2 locations; spatially aggregated precipitation rates, total subsurface discharge, and relative water storage; and the measurements from a weather station outside the greenhouses.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Highly Sampled Measurements in a Controlled Atmosphere at the Biosphere 2 Landscape Evolution Observatory

Land-atmosphere interactions at different temporal and spatial scales are important for our understanding of the Earth system and its modeling. The Landscape Evolution Observatory (LEO) at Biosphere 2 managed by the University of Arizona host three nearly identical artificial bare-soil hillslopes with dimensions of 30m x 11m and 1m average depth in a controlled and highly monitored environment under a large greenhouse. These facilities provide a unique opportunity to explore these interactions. This dataset contains, for each one of the three replicate hillslopes, 15-minute measurements from July 1, 2015 to June 30, 2019 of temperature, water content and heat flux of the soil at a depth of 5cm for 12 co-located points; temperature, relative humidity and wind speed above ground at 5 different locations over each hillslope and 5 different heights ranging from 0.25m to 9-10m; 3D wind components at 1 location; the 4 components of radiation at 2 different locations; precipitation rates; and the measurements of an automatic weather station outside the greenhouse