86 research outputs found

    Effects of Fish Oil Supplementation on Post-Resistance Exercise Muscle Soreness in Untrained Females

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    The anti-inflammatory properties of omega-3 fatty acids contained in fish oil may help alleviate symptoms of delayed onset of muscle soreness (DOMS) and improve recovery from exercise. PURPOSE: To examine the effects of fish oil supplementation on the time-course of post-resistance exercise muscle soreness in young untrained females. METHODS: Seventeen non-resistance trained females (age 23.6 ± 3.0 y, % fat 27.4 ± 3.2, weight 60.2 ± 9.6 kg) were randomized into one of two groups: fish oil (6 g/d; 5:1 EPA:DHA) or placebo (6 g/d corn/soy oil). After consuming the supplements for one week, participants underwent a single bout of resistance exercise designed to induce muscle damage. Subjects performed 10 sets to failure of biceps curl machine and leg extensions using 50% of the previously measured 1-repetition maximum. Over the next week, subjective muscle soreness of the upper and lower body was measured via a grounded 10-cm visual analog scale. At 48 hours and 1 week post-exercise, subjects performed a test to determine soreness during functional movements. The comparison-wise error rate was set at p \u3c 0.10. RESULTS: Muscle soreness increased significantly in both groups and peaked at 48 hours post-exercise. The fish oil group perceived less muscle soreness in the lower body than the placebo group (p= 0.06), but there was no difference in the upper body (p= 0.27). The fish oil group reported less perceived soreness during functional movements (p= 0.07 for upper and lower body soreness). Effect sizes, indicating the reduction in muscle soreness that may be attributed to fish oil (Δ effect size between groups), was 0.75 (95% CI: -0.70 – 2.20) for the arms and 0.77 (-0.76 – 2.33) for the legs. The effect size for the functional tests was 0.63 (-0.71 – 1.97) for the arms and 0.57 (-0.85 – 1.99) for the legs. CONCLUSION: Supplementing the diet with 6 grams per day of fish oil may alleviate the muscle soreness experienced after resistance training in young untrained females, but additional studies with larger sample sizes should be conducted to confirm these findings

    Lack of phenotypic and evolutionary cross-resistance against parasitoids and pathogens in Drosophila melanogaster

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    BackgroundWhen organisms are attacked by multiple natural enemies, the evolution of a resistance mechanism to one natural enemy will be influenced by the degree of cross-resistance to another natural enemy. Cross-resistance can be positive, when a resistance mechanism against one natural enemy also offers resistance to another; or negative, in the form of a trade-off, when an increase in resistance against one natural enemy results in a decrease in resistance against another. Using Drosophila melanogaster, an important model system for the evolution of invertebrate immunity, we test for the existence of cross-resistance against parasites and pathogens, at both a phenotypic and evolutionary level.MethodsWe used a field strain of D. melanogaster to test whether surviving parasitism by the parasitoid Asobara tabida has an effect on the resistance against Beauveria bassiana, an entomopathogenic fungus; and whether infection with the microsporidian Tubulinosema kingi has an effect on the resistance against A. tabida. We used lines selected for increased resistance to A. tabida to test whether increased parasitoid resistance has an effect on resistance against B. bassiana and T. kingi. We used lines selected for increased tolerance against B. bassiana to test whether increased fungal resistance has an effect on resistance against A. tabida.Results/ConclusionsWe found no positive cross-resistance or trade-offs in the resistance to parasites and pathogens. This is an important finding, given the use of D. melanogaster as a model system for the evolution of invertebrate immunity. The lack of any cross-resistance to parasites and pathogens, at both the phenotypic and the evolutionary level, suggests that evolution of resistance against one class of natural enemies is largely independent of evolution of resistance against the other

    The UV-Optical Color Dependence of Galaxy Clustering in the Local Universe

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    We measure the UV-optical color dependence of galaxy clustering in the local universe. Using the clean separation of the red and blue sequences made possible by the NUV - r color-magnitude diagram, we segregate the galaxies into red, blue and intermediate "green" classes. We explore the clustering as a function of this segregation by removing the dependence on luminosity and by excluding edge-on galaxies as a means of a non-model dependent veto of highly extincted galaxies. We find that \xi (r_p, \pi) for both red and green galaxies shows strong redshift space distortion on small scales -- the "finger-of-God" effect, with green galaxies having a lower amplitude than is seen for the red sequence, and the blue sequence showing almost no distortion. On large scales, \xi (r_p, \pi) for all three samples show the effect of large-scale streaming from coherent infall. On scales 1 Mpc/h < r_p < 10 Mpc/h, the projected auto-correlation function w_p(r_p) for red and green galaxies fits a power-law with slope \gamma ~ 1.93 and amplitude r_0 ~ 7.5 and 5.3, compared with \gamma ~ 1.75 and r_0 ~ 3.9 Mpc/h for blue sequence galaxies. Compared to the clustering of a fiducial L* galaxy, the red, green, and blue have a relative bias of 1.5, 1.1, and 0.9 respectively. The w_p(r_p) for blue galaxies display an increase in convexity at ~ 1 Mpc/h, with an excess of large scale clustering. Our results suggest that the majority of blue galaxies are likely central galaxies in less massive halos, while red and green galaxies have larger satellite fractions, and preferentially reside in virialized structures. If blue sequence galaxies migrate to the red sequence via processes like mergers or quenching that take them through the green valley, such a transformation may be accompanied by a change in environment in addition to any change in luminosity and color.Comment: accepted by MNRA

    The Formation of Dust Lanes: Implications for Galaxy Evolution

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    We find that disk galaxies show a sharp, mass-dependent transition in the structure of their dusty ISM. Dust lanes are a generic feature of massive disks with V_rot>120km/s, but are completely absent in galaxies with V_rot<120km/s. The transition reflects an increase in the scale height of the cold ISM in low mass galaxies, driven by larger turbulent velocities supporting the gas layer, rather than sharp drops in the gas surface density. We identify the V_rot=120km/s transition with the onset of gravitational instabilities in high mass galaxies. The instabilities lead to fragmentation and gravitational collapse along spiral arms, smaller gas scale heights, lower turbulent velocities, and thus to narrow dust lanes. The drop in velocity dispersion may be due either to a switch in the driving mechanism for turbulence or to a change in the response of the ISM to supernovae after the ISM has collapsed to a dense layer. The resulting smaller gas scale height can lead to significant increases in the star formation rate when disk instabilities are present, and may explain the Kennicutt surface density threshold for star formation. Our data suggest that star formation will be systematically less efficient in low mass disks with V_c<120km/s, leading to star formation timescales longer than the gas accretion timescale. This effect can suppress the metallicity and nucleosynthetic yields of low mass disks, and thus explain the disk mass-metallicity relationship without invoking galactic SN-driven outflows. The transitions in disk stability, dust structure, and/or star formation efficiency may also be responsible for observed changes in the slope of the Tully-Fisher relation, in the sharp increase in the thickness of dwarf galaxy disks, and in the onset of bulges in galaxies with V_rot>120km/s. (Abridged)Comment: 20 pages, Accepted by the Astrophysical Journa

    The Complement Anaphylatoxin C5a Induces Apoptosis in Adrenomedullary Cells during Experimental Sepsis

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    Sepsis remains a poorly understood, enigmatic disease. One of the cascades crucially involved in its pathogenesis is the complement system. Especially the anaphylatoxin C5a has been shown to have numerous harmful effects during sepsis. We have investigated the impact of high levels of C5a on the adrenal medulla following cecal ligation and puncture (CLP)-induced sepsis in rats as well as the role of C5a on catecholamine production from pheochromocytoma-derived PC12 cells. There was significant apoptosis of adrenal medulla cells in rats 24 hrs after CLP, as assessed by the TUNEL technique. These effects could be reversed by dual-blockade of the C5a receptors, C5aR and C5L2. When rats were subjected to CLP, levels of C5a and norepinephrine were found to be antipodal as a function of time. PC12 cell production of norepinephrine and dopamine was significantly blunted following exposure to recombinant rat C5a in a time-dependent and dose-dependent manner. This impaired production could be related to C5a-induced initiation of apoptosis as defined by binding of Annexin V and Propidium Iodine to PC12 cells. Collectively, we describe a C5a-dependent induction of apoptotic events in cells of adrenal medulla in vivo and pheochromocytoma PC12 cells in vitro. These data suggest that experimental sepsis induces apoptosis of adrenomedullary cells, which are responsible for the bulk of endogenous catecholamines. Septic shock may be linked to these events. Since blockade of both C5a receptors virtually abolished adrenomedullary apoptosis in vivo, C5aR and C5L2 become promising targets with implications on future complement-blocking strategies in the clinical setting of sepsis

    The Apache Point Observatory Galactic Evolution Experiment (APOGEE)

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    The Apache Point Observatory Galactic Evolution Experiment (APOGEE), one of the programs in the Sloan Digital Sky Survey III (SDSS-III), has now completed its systematic, homogeneous spectroscopic survey sampling all major populations of the Milky Way. After a three-year observing campaign on the Sloan 2.5 m Telescope, APOGEE has collected a half million high-resolution (R ~ 22,500), high signal-to-noise ratio (>100), infrared (1.51–1.70 μm) spectra for 146,000 stars, with time series information via repeat visits to most of these stars. This paper describes the motivations for the survey and its overall design—hardware, field placement, target selection, operations—and gives an overview of these aspects as well as the data reduction, analysis, and products. An index is also given to the complement of technical papers that describe various critical survey components in detail. Finally, we discuss the achieved survey performance and illustrate the variety of potential uses of the data products by way of a number of science demonstrations, which span from time series analysis of stellar spectral variations and radial velocity variations from stellar companions, to spatial maps of kinematics, metallicity, and abundance patterns across the Galaxy and as a function of age, to new views of the interstellar medium, the chemistry of star clusters, and the discovery of rare stellar species. As part of SDSS-III Data Release 12 and later releases, all of the APOGEE data products are publicly available

    Cold atoms in space: community workshop summary and proposed road-map

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    We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.publishedVersio

    Cold atoms in space: community workshop summary and proposed road-map

    Get PDF
    We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies
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