874 research outputs found
KINETICS OF LOWER EXTREMITY DURING OVERGROUND HILL RUNNING IN FOREFOOT STRIKE RUNNERS
The aim of this study was to compare the lower extremity kinetics of forefoot strike (FFS) level ground running to those occurring during uphill and downhill running. Habitual FFS runners (n=5) completed overground trials during uphill and downhill conditions on a ramp set to 6? and 9? and during level running at a speed of 3 m/s ± 5%. Peak ground reaction forces (GRF), joint moment, and power absorption of lower limb were analyzed. GRF showed an absent impact transient in all conditions. Peak power absorptions did not change significantly during any of the hill running conditions compared to the level trial. Knee extension moment increased only during the 9? downhill condition. The findings suggest that running on hills with a FFS is characterized by an absent impact transient that is thought as a sign of less impact on the lower limb and may help to reduce injury risk
WRAPPING SURFACES TO CONTROL MOMENT ARM LENGTHS DURING A SQUAT TASK
Simulation of high flexion tasks such as squatting is hindered through invalid moment length estimation when using generic musculoskeletal (MSK) models. The purpose of this study was to examine the effect of wrapping surface (WS) at the knee and hip joints on the muscle moment arms calculated using a MSK model during squatting tasks. A generic full body model was modified by (1) increasing knee and hip flexion range of motion (ROM), (2) adjusting translation and size parameters of two WS, and (3) implementing three additional WS. Muscle moment-arm lengths were calculated in OpenSim using motion capture data. The WS prevent muscles to cross into the bones, and the moment arm length of several hip extensors reach a plateau after 85Âș of hip flexion. The use of the modified MSK that includes additional WS is suited for the analysis of high flexion tasks
Photocatalytic bleaching of p-nitrosodimethylaniline and a comparison to the performance of other AOP technologies
Commonalities of carbon dioxide exchange in semiarid regions with monsoon and Mediterranean climates
Comparing biosphereâatmosphere carbon exchange across monsoon (warm-season rainfall) and Mediterranean (cool-season rainfall) regimes can yield information about the interaction between energy and water limitation. Using data collected from eddy covariance towers over grass and shrub ecosystems in Arizona, USA and Almeria, Spain, we used net ecosystem carbon dioxide exchange (NEE), gross ecosystem production (GEP), and other meteorological variables to examine the effects of the different precipitation seasonality. Considerable crossover behavior occurred between the two rainfall regimes. As expected in these usually water-limited ecosystems, precipitation magnitude and timing were the dominant drivers of carbon exchange, but temperature and/or light also played an important role in regulating GEP and NEE at all sites. If significant rainfall occurred in the winter at the Arizona sites, their behavior was characteristically Mediterranean whereby the carbon flux responses were delayed till springtime. Likewise, the Spanish Mediterranean sites showed immediate pulse-like responses to rainfall events in non-winter periods. The observed site differences were likely due to differences in vegetation, soils, and climatology. Together, these results support a more unified conceptual model for which processes governing carbon cycling in semiarid ecosystems need not differ between warm-season and cool-season rainfall regimes.This paper is the result of a fellowship funded by the OECD Co-operative Research Programme: Biological Resource Management for Sustainable Agricultural Systems to R.L. Scott. This paper has been supported in part by the Andalusian regional government project GEOCARBO and GLOCHARID (P08-RNM-3721), European Union Funds (ERDF and ESF), the Spanish flux-tower network CARBORED-ES (Science Ministry project CGL2010-22193-C04-02), and the European Commission collaborative project GHG Europe (FP7/2007-2013; grant agreement 244122)
SmartAQnet 2020: A New Open Urban Air Quality Dataset from Heterogeneous PM Sensors
The increasing attention paid to urban air quality modeling places higher requirements on urban air quality datasets. This article introduces a new urban air quality datasetâthe SmartAQnet2020 datasetâwhich has a large span and high resolution in both time and space dimensions. The dataset contains 248,572,003 observations recorded by over 180 individual measurement devices, including ceilometers, Radio Acoustic Sounding System (RASS), mid- and low-cost stationary measuring equipment equipped with meteorological sensors and particle counters, and low-weight portable measuring equipment mounted on different platforms such as trolley, bike, and UAV
Differential limit on the extremely-high-energy cosmic neutrino flux in the presence of astrophysical background from nine years of IceCube data
We report a quasi-differential upper limit on the extremely-high-energy (EHE)
neutrino flux above GeV based on an analysis of nine years of
IceCube data. The astrophysical neutrino flux measured by IceCube extends to
PeV energies, and it is a background flux when searching for an independent
signal flux at higher energies, such as the cosmogenic neutrino signal. We have
developed a new method to place robust limits on the EHE neutrino flux in the
presence of an astrophysical background, whose spectrum has yet to be
understood with high precision at PeV energies. A distinct event with a
deposited energy above GeV was found in the new two-year sample, in
addition to the one event previously found in the seven-year EHE neutrino
search. These two events represent a neutrino flux that is incompatible with
predictions for a cosmogenic neutrino flux and are considered to be an
astrophysical background in the current study. The obtained limit is the most
stringent to date in the energy range between and GeV. This result constrains neutrino models predicting a three-flavor
neutrino flux of $E_\nu^2\phi_{\nu_e+\nu_\mu+\nu_\tau}\simeq2\times 10^{-8}\
{\rm GeV}/{\rm cm}^2\ \sec\ {\rm sr}10^9\ {\rm GeV}$. A significant part
of the parameter-space for EHE neutrino production scenarios assuming a
proton-dominated composition of ultra-high-energy cosmic rays is excluded.Comment: The version accepted for publication in Physical Review
SmartAQnet â neuer smarter Weg zur rĂ€umlichen Erfassung von Feinstaub
Mit dem Forschungsprojekt SmartAQnet wird ein smarter Weg zur rÀumlichen
Bestimmung von Feinstaub untersucht und am Modellstandort Augsburg erprobt. Forschungsansatz ist
die Erfassung und ZusammenfĂŒhrung unterschiedlicher QualitĂ€ten von Feinstaubmesswerten mit Fernerkundungsdaten.
Feinstaubmesswerte können hierbei von Jedermann (z. B. mit Ultra-Low-Cost-Sensoren)
bis hin zu offiziellen Messnetzen (mit hochprÀziser Messtechnik) in die Datenarchitektur eingespeist
werden. Eine neuartige Internet-of-Things-Analyseplattform soll Daten zur Anwendung sowohl
fĂŒr Planer als auch fĂŒr den BĂŒrger bieten, welche der nachhaltigen Gesundheitsvorsorge dienen können
(z. B. App fĂŒr eine luftqualitĂ€tsbezogene Navigation)
State Control and the Effects of Foreign Relations on Bilateral Trade
Do states use trade to reward and punish partners? WTO rules and the pressures of globalization restrict statesâ capacity to manipulate trade policies, but we argue that governments can link political goals with economic outcomes using less direct avenues of inïŹuence over ïŹrm behavior. Where governments intervene in markets, politicization of trade is likely to occur. In this paper, we examine one important form of government control: state ownership of ïŹrms. Taking China and India as examples, we use bilateral trade data by ïŹrm ownership type, as well as measures of bilateral political relations based on diplomatic events and UN voting to estimate the effect of political relations on import and export ïŹows. Our results support the hypothesis that imports controlled by state-owned enterprises (SOEs) exhibit stronger responsiveness to political relations than imports controlled by private enterprises. A more nuanced picture emerges for exports; while Indiaâs exports through SOEs are more responsive to political tensions than its ïŹows through private entities, the opposite is true for China. This research holds broader implications for how we should think about the relationship
between political and economic relations going forward, especially as a number of countries with partially state-controlled economies gain strength in the global economy
Colloidal Flower-Shaped Iron Oxide Nanoparticles: Synthesis Strategies and Coatings
The assembly of magnetic cores into regular structures may notably influence the properties displayed by a magnetic colloid. Here, key synthesis parameters driving the self-assembly process capable of organizing colloidal magnetic cores into highly regular and reproducible multi-core nanoparticles are determined. In addition, a self-consistent picture that explains the collective magnetic properties exhibited by these complex assemblies is achieved through structural, colloidal, and magnetic means. For this purpose, different strategies to obtain flower-shaped iron oxide assemblies in the size range 25-100 nm are examined. The routes are based on the partial oxidation of Fe(OH)(2), polyol-mediated synthesis or the reduction of iron acetylacetonate. The nanoparticles are functionalized either with dextran, citric acid, or alternatively embedded in polystyrene and their long-term stability is assessed. The core size is measured, calculated, and modeled using both structural and magnetic means, while the Debye model and multi-core extended model are used to study interparticle interactions. This is the first step toward standardized protocols of synthesis and characterization of flower-shaped nanoparticles
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