9,456 research outputs found

    Differences in oxygenation kinetics between the dominant and non-dominant flexor digitorum profundus in rock climbers

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    Purpose. This study examined differences in oxygenation kinetics in the non-dominant and dominant flexor digitorum profundus (FDP) of rock climbers. Methods. Participants consisted of 28 sport climbers with a range of on-sight abilities (6a+ to 8a French Sport). Using near infrared spectroscopy, oxygenation kinetics of the FDP was assessed by calculating the time to half recovery (t½ recovery) of the tissue saturation index (TSI) following 3-5 min of ischemia. Results. A 2-way mixed model ANOVA found a non-significant interaction (p =0.112) for TSI x sex. However, there was a significant the main effect (p =0.027) handedness (dominant vs. non-dominant FDP). The dominant forearm recovered 13.6% quicker (t½ recovery mean difference = 1.12 sec, 95% CI 0.13 to 2.10 sec) compared to the non-dominant FDP. This was not affected by 6-month on-sight climbing ability or sex (p =0.839, p =0.683). Conclusions. Significant intra-individual differences in oxygenation kinetics of the FDP were found. Improvements in oxygenation kinetics within the FDP are likely due to the abilities of the muscle to deliver, perfuse and consume oxygen. These enhancements may be due to structural adaptations in the microvasculature such as an increase in capillary density and an enhanced improvement in capillary filtration

    Sonochemically-induced spectral shift as a probe of green fluorescent protein release from nano capsules

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    Encapsulation in the form of micro and nanocapsules is an attractive route for controlling the delivery and release of active proteins and peptides. Many approaches exist to probe the morphology of such capsules as well as their mechanisms of formation. By contrast, the release of proteins from such components in a complex biological environment has been challenging to probe directly. In this paper we show that the spectral differences between green fluorescent protein (GFP) in capsules and in its free form can be used to monitor in situ the release of the protein from the confinement of capsules. These findings represent a new route towards engineering the spectral characteristics of GFP through physical rather than chemical means. We demonstrate the use of GFP protein capsules for monitoring in real time the release of protein in live cells by exposing rat L6 myotubes to protein capsules. The GFP spheres with a blue fluorescent signal dissociate inside the L6 myotubes to individual GFP molecules with a change in fluorescent signal from blue to green. These sensitive spectral characteristics enabled us to resolve the dissociation of capsules inside the cells in both time and space. We discuss the implications of our results for quantifying parameters crucial for the delivery of proteins in biological environments

    A single-molecule assay for telomerase structure-function analysis

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    The activity of the telomerase ribonucleoprotein enzyme is essential for the maintenance of genome stability and normal cell development. Despite the biomedical importance of telomerase activity, detailed structural models for the enzyme remain to be established. Here we report a single-molecule assay for direct structural analysis of catalytically active telomerase enzymes. In this assay, oligonucleotide hybridization was used to probe the primer-extension activity of individual telomerase enzymes with single nucleotide sensitivity, allowing precise discrimination between inactive, active and processive enzyme binding events. FRET signals from enzyme molecules during the active and processive binding events were then used to determine the global organization of telomerase RNA within catalytically active holoenzymes. Using this assay, we have identified an active conformation of telomerase among a heterogeneous population of enzymes with distinct structures

    Fungi in a Warmer World: Fungal Diversity in the Tropical Miocene Climate Optimum of the Clarkia Region of Idaho, USA

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    A knowledge gap associated with how fungal communities change in response to climate was identified in the 2018 State of the World Fungi report (Willis, 2018). While it is virtually impossible to test in the present, fungal assemblage changes can be studied in sediments from a warmer-than-present period such as the Miocene Climate Optimum (MCO) (Romero et al. 2021; O’Keefe 2017). The Fungi in a Warmer World project aims to generate and analyze a global-scale data set of fungal biodiversity, ecology, and associated flora from MCO sediments. This dataset will be used to model past fungal assemblage changes across the MCO and forecast future changes in line with IPCC RCP 4.5-8.5 warming.https://scholarworks.moreheadstate.edu/celebration_posters_2022/1003/thumbnail.jp

    Fungi in a Warmer World: Middle Miocene Fungal Assemblages and Diversity from Alum Bluff, Florida

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    Fungi play a key role in the terrestrial carbon cycle, soil formation, and overall plant growth as terrestrial decomposers (1, 2). Thus, the study of fungi, especially in the fossil record, is critical to understanding how fungal assemblages will react to future warming events. Fossil fungi provide a large-scale, long-term dataset unavailable from modern records, allowing for the generation of viable paleoclimate reconstructions and predictions (3, 4). Despite their importance and advantages in forming ecological and climatological interpretations, deep-time fungi have been underutilized (3). The Fungi in a Warmer World (FiaWW) project aims to deliver the first global view of fungal biodiversity, ecology, and biogeography for the Miocene Climate Optimum (MCO): the warmest interval of the last 23 MY. The MCO is a good proxy for near-future climate change scenarios because atmospheric CO2 concentrations ranged between current concentrations of ~400ppm and future projected concentrations for the end of this century (5, 6).https://scholarworks.moreheadstate.edu/celebration_posters_2022/1040/thumbnail.jp

    High-energy Particle Acceleration and Production of Ultra-high-energy Cosmic Rays in the Giant Lobes of Centaurus A

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    ‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2008.14265.xThe nearby radio galaxy Centaurus A is poorly studied at high frequencies with conventional radio telescopes because of its very large angular size, but is one of a very few extragalactic objects to be detected and resolved by the Wilkinson Microwave Anisotropy Probe (WMAP).We have used the five-year WMAP data for Cen A to constrain the high-frequency radio spectra of the 10-degree giant lobes and to search for spectral changes as a function of position along the lobes. We show that the high-frequency radio spectra of the northern and southern giant lobes are significantly different: the spectrum of the southern lobe steepens monotonically (and is steeper further from the active nucleus) whereas the spectrum of the northern lobe remains consistent with a power law. The inferred differences in the northern and southern giant lobes may be the result of real differences in their high-energy particle acceleration histories, perhaps due to the influence of the northern middle lobe, an intermediate-scale feature which has no detectable southern counterpart. In light of these results, we discuss the prospects for Gamma-ray Large Area Space Telescope (GLAST) detections of inverse-Compton emission from the giant lobes and the lobes’ possible role in the production of the ultra-high energy cosmic rays (UHECR) detected by the Pierre Auger Observatory. We show that the possibility of a GLAST detection depends sensitively on the physical conditions in the giant lobes, with the northern lobe more likely to be detected, and that any emission observed by GLAST is likely to be restricted to the soft end of the GLAST energy band. On the other hand we argue that the estimated conditions in the giant lobes imply that UHECRs can be accelerated there, with a potentially detectable -ray signature at GeV-TeV energies.Peer reviewe

    Effect of solvent and extraction temperatures on the antioxidant potential of traditional stoned table olives “alcaparras”

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    This paper reports the first approach to the antioxidant potential evaluation of traditional stoned table olives ‘‘alcaparras’’. This kind of olives are largely produced and consumed in Trás-os-Montes region (Northeast of Portugal). Different solvents and temperature extraction conditions were employed in order to achieve the best method to obtain phenolic compounds and a higher antioxidant activity. The optimum method (water at boiling temperature) was applied on 10 samples from the traditional market. The total phenol content ranged between 5.58mg gallic acid equivalents (GAE)/g and 29.88mg GAE/g and effective concentration (EC50) values were in the range 0.36–1.64 and 0.34–1.72 mg/mL for reducing power and radical scavenging effect, respectively. A significantly negative linear regression was observed between the total phenol content found in the samples and its antioxidant activity

    Decoherence of Schrodinger cat states in a Luttinger liquid

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    Schrodinger cat states built from quantum superpositions of left or right Luttinger fermions located at different positions in a spinless Luttinger liquid are considered. Their decoherence rates are computed within the bosonization approach using as environments the quantum electromagnetic field or two or three dimensionnal acoustic phonon baths. Emphasis is put on the differences between the electromagnetic and acoustic environments.Comment: 22 pages revtex4, 7 figures in a separate PS fil

    Disentangling the Effects of Applicant Defensive Impression Management Tactics in Job Interviews

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    This study explores (1) the effects that three kinds of applicant defensive impression management (IM) tactics (apologies, justifications, and excuses) have on interviewer evaluation and (2) the moderating effects that two types of interviewer negative concerns (competence-related and integrity-related concerns) have on the aforementioned relationship. Two hundred and one managers from Taiwan participated in this study by watching a simulated interview. Compared with the control group, applicants using defensive IM tactics received higher interviewer ratings when negative concerns surfaced. Moreover, the type of interviewer negative concern moderated the effects of defensive IM tactics. All three tactics had similar effects on interviewer evaluation when the concern was competence related. Apology was, however, the most effective tactic when the concern was integrity related.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79091/1/j.1468-2389.2010.00495.x.pd
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