212 research outputs found

    Comparison of Metabolic Variables during the 2-Minute Walk Test and 6-Minute Walk Test

    Get PDF
    Assessing for functional mobility and fitness in deconditioned populations is common practice in many clinics. Comparison of the 2-minute walk test (2MWT) as a predictor for 6-minute walk test (6MWT) metabolic variables will save clinicians time and effort when performing baseline testing. PURPOSE: To determine if the 2MWT can be used as a viable means of accessing baseline fitness versus the 6MWT. METHODS: Ten subjects (48.3±15.7 yrs, 168.5±8.6 cm, 75.5±13.6 kg) reported on two separate days to perform the tests. Once fitted with a heart rate (HR) monitor and portable O2 analyzer, they performed either the 2MWT or 6MWT and on the second day performed the other. Repeated measures ANOVA were used to determine significant differences with pairwise comparisons utilizing the Bonferroni technique. Alpha was set at .05 for all tests. RESULTS: While there was no significant difference in VO2 between the 2-min time point of the 2MWT (16.9±4.6 ml/kg/min) and the 2-min time point of the 6-min walk test (17.1±5.6 ml/kg/min), p=1.0, there was a significant difference between the 2-min time point of the 2MWT and the 6-min time point of the 6MWT (21.4±4.6 ml/kg/min), p=. 007. There was no significant difference in HR between any of the time points (p\u3e.05). CONCLUSION: Caution should be taken if using the 2MWT as a measure of fitness since it seems participants are not yet in steady state at the 2-minute mar

    Farmers' perceived values in conventional and organic farming: A comparison between French, Irish and Swedish farmers using the Means-end chain approach

    Get PDF
    Values act as driving forces for individuals to behave in a certain way or to choose certain actions. They may explain current differences of converted organic land among EU countries. In this paper, we identified and compared the types of values, economic and other, that motivate farmers to choose certified organic or con-ventional production systems in France, Ireland and Sweden. To identify these values, we analysed and compared attribute-consequence-value representations of the choice of production systems among farmers, using a Means-end chain approach. Seventy-eight in-depth laddering interviews were conducted to explore how farmers characterised their choice, the consequences they perceived from these characteristics and the values they associated with these consequences. The uncovered values were classified along Rokeach's typology to distin-guish between instrumental and terminal values. Results indicate that both farmers with a conventional farm and farmers with a certified organic farm are driven by complex sets of financial, business, or productivity values and by non-financial, non-business, or non-productivity values. Findings are useful to policy makers and farm ad -visors, who can use these results to develop more efficient communication schemes to promote organic farming. The findings can also be communicated to consumers and the public in order to encourage consumption

    The role of earth observation in an integrated deprived area mapping “system” for low-to-middle income countries

    Get PDF
    Urbanization in the global South has been accompanied by the proliferation of vast informal and marginalized urban areas that lack access to essential services and infrastructure. UN-Habitat estimates that close to a billion people currently live in these deprived and informal urban settlements, generally grouped under the term of urban slums. Two major knowledge gaps undermine the efforts to monitor progress towards the corresponding sustainable development goal (i.e., SDG 11—Sustainable Cities and Communities). First, the data available for cities worldwide is patchy and insufficient to differentiate between the diversity of urban areas with respect to their access to essential services and their specific infrastructure needs. Second, existing approaches used to map deprived areas (i.e., aggregated household data, Earth observation (EO), and community-driven data collection) are mostly siloed, and, individually, they often lack transferability and scalability and fail to include the opinions of different interest groups. In particular, EO-based-deprived area mapping approaches are mostly top-down, with very little attention given to ground information and interaction with urban communities and stakeholders. Existing top-down methods should be complemented with bottom-up approaches to produce routinely updated, accurate, and timely deprived area maps. In this review, we first assess the strengths and limitations of existing deprived area mapping methods. We then propose an Integrated Deprived Area Mapping System (IDeAMapS) framework that leverages the strengths of EO- and community-based approaches. The proposed framework offers a way forward to map deprived areas globally, routinely, and with maximum accuracy to support SDG 11 monitoring and the needs of different interest groups

    Final Design and On-Sky Testing of the iLocater SX Acquisition Camera: Broadband Single-Mode Fiber Coupling

    Full text link
    Enabling efficient injection of light into single-mode fibers (SMFs) is a key requirement in realizing diffraction-limited astronomical spectroscopy on ground-based telescopes. SMF-fed spectrographs, facilitated by the use of adaptive optics (AO), offer distinct advantages over comparable seeing-limited designs, including higher spectral resolution within a compact and stable instrument volume, and a telescope independent spectrograph design. iLocater is an extremely precise radial velocity (EPRV) spectrograph being built for the Large Binocular Telescope (LBT). We have designed and built the front-end fiber injection system, or acquisition camera, for the SX (left) primary mirror of the LBT. The instrument was installed in 2019 and underwent on-sky commissioning and performance assessment. In this paper, we present the instrument requirements, acquisition camera design, as well as results from first-light measurements. Broadband single-mode fiber coupling in excess of 35% (absolute) in the near-infrared (0.97-1.31{\mu}m) was achieved across a range of target magnitudes, spectral types, and observing conditions. Successful demonstration of on-sky performance represents both a major milestone in the development of iLocater and in making efficient ground-based SMF-fed astronomical instruments a reality.Comment: 18 pages, 17 figures. Accepted for publication in MNRA

    Nautical Research Platform for Water-Bound Experiments

    Get PDF
    Conducting research in lakes and rivers requires large crews and heavy-duty equipment, making even simple tests more costly and time consuming. Newer research methods are evolving constantly as new technology enables more precise and accessible experiments to be conducted. The need for simple execution of water-bound experiments exists and must be addressed to aid our understanding of these environments. We at the Microgravity Undergraduate Research Team have taken our previous research in autonomous Unmanned Surface Vehicles (USVs) and applied our efforts to relieving this problem. Our current research aims to provide a universal platform for research and experiments to be conducted in lakes and rivers, where we can then expand our efforts to more broad applications. The design allows for remote-control navigation by one user and easy portability. To address precision in experimentation, we have integrated autonomous GPS waypoint navigation which removes user error in sensitive measurements. The most important factor in its design is modularity; the ability to accommodate a wide range of equipment for research. Our platform succeeds in making water-bound experiments more accessible and more precise for a multitude of potential applications

    Abrupt changes of temperature and water chemistry in the late Pleistocene and early Holocene Black Sea

    Get PDF
    Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q01004, doi:10.1029/2007GC001683.New Mg/Ca, Sr/Ca, and published stable oxygen isotope and 87Sr/86Sr data obtained on ostracods from gravity cores located on the northwestern Black Sea slope were used to infer changes in the Black Sea hydrology and water chemistry for the period between 30 to 8 ka B.P. (calibrated radiocarbon years). The period prior to 16.5 ka B.P. was characterized by stable conditions in all records until a distinct drop in δ 18O values combined with a sharp increase in 87Sr/86Sr occurred between 16.5 and 14.8 ka B.P. This event is attributed to an increased runoff from the northern drainage area of the Black Sea between Heinrich Event 1 and the onset of the Bølling warm period. While the Mg/Ca and Sr/Ca records remained rather unaffected by this inflow; they show an abrupt rise with the onset of the Bølling/Allerød warm period. This rise was caused by calcite precipitation in the surface water, which led to a sudden increase of the Sr/Ca and Mg/Ca ratios of the Black Sea water. The stable oxygen isotopes also start to increase around 15 ka B.P., although in a more gradual manner, due to isotopically enriched meteoric precipitation. While Sr/Ca remains constant during the following interval of the Younger Dryas cold period, a decrease in the Mg/Ca ratio implies that the intermediate water masses of the Black Sea temporarily cooled by 1–2°C during the Younger Dryas. The 87Sr/86Sr values drop after the cessation of the water inflow at 15 ka B.P. to a lower level until the Younger Dryas, where they reach values similar to those observed during the Last Glacial Maximum. This might point to a potential outflow to the Mediterranean Sea via the Sea of Marmara during this period. The inflow of Mediterranean water started around 9.3 ka B.P., which is clearly detectable in the abruptly increasing Mg/Ca, Sr/Ca, and 87Sr/86Sr values. The accompanying increase in the δ 18O record is less pronounced and would fit to an inflow lasting ∼100 a.This research was funded by the DFG grants LA 1273/2-1, LA 1273/2, and WE 992/47-3. RCOM 0517

    Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

    Get PDF
    Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology
    corecore