2,397 research outputs found

    Multiaperture UBVRIzJHKUBVRIzJHK Photometry of Galaxies in the Coma Cluster

    Get PDF
    We present a set of UBVRIzJHKsUBVRIzJHK_s photometry for 745 J+HJ+H band selected objects in a 22.5′×29.2′22.5' \times 29.2' region centered on the core of the Coma cluster. This includes 516 galaxies and is at least 80% complete to H=16, with a spectroscopically complete sample of 111 cluster members (nearly all with morphological classification) for H<14.5H < 14.5. For each object we present total \cite{kron80} magnitudes and aperture photometry. As an example, we use these data to derive color-magnitude relations for Coma early-type galaxies, measure the intrinsic scatter of these relations and its dependence on galaxy mass, and address the issue of color gradients. We find that the color gradients are mild and that the intrinsic scatter about the color-magnitude relation is small (∼0.05\sim 0.05 mag in U−VU-V and less than ∼0.03\sim 0.03 in B−RB-R, V−IV-I or J−KJ-K). There is no evidence that the intrinsic scatter varies with galaxy luminosity, suggesting that the cluster red sequence is established at early epochs over a range of ∼100\sim 100 in stellar mass.Comment: 41 pages, 5 figures, 18 data tables attached to source files or available on request from R. De propris. Accepted for publication in Astrophysical Journal Supplement Serie

    Original Article Vascular hypercontractility and endothelial dysfunction before development of atherosclerosis in moderate dyslipidemia: role for nitric oxide and interleukin-6

    Get PDF
    Abstract: Atherosclerosis is a chronic disease that affects peripheral arteries and the aorta. Several inflammatory processes are required until the production of an atheroma. Before the atheroma appears, endothelial dysfunction is a key event. We hypothesized that endothelial dysfunction occurs in a mouse model of mild dyslipidemia, the mouse deficient in apolipoprotein E (apoE +/-). Using aortic rings preparation, we found that apoE +/-mice showed increased developed tension in response to KCl 60 mM when using a range a pre-loads from 0.5 to 2.0 grams (p = 0.038). Next, we tested the vasorelaxant capacity of apoE +/-aortas (pre-contracted with phenylephrine) in response to acetylcholine, an endothelium-dependent vasodilator. ApoE +/-aortas showed diminished vasorelaxation in a range of Ach concentrations (p = 0.0032). Next we assessed the levels of plasma NO metabolites, nitrite plus nitrate. These were significantly reduced, along with a significant decrease of the endothelial nitric oxide synthase in ApoE +/-mice. When we analyzed the morphology of the aortas in apoE +/-mice, these showed no signs of atheroma. In addition, we analyzed the levels of inflammatory cytokines, TNF-alpha, MCP-1 and interleukin 6 (Il-6). While TNFalpha was similar in both groups, (18.3 ± 2 pg/mL in wild type vs. 17.5 ± 2 pg/mL in apoE +/-), MCP-1 was increased in ApoE deficient mice (71.5 ± 0.8 pg/mL in wild type vs. 85.1 ± 7.4 pg/mL in ApoE +/-mice, p = 0.006), along with IL-6 (24.7 ± 1.7 pg/ml in wild type vs. 47.1 ± 12.5 in ApoE mice, p = 0.0055). These results suggest that mild dyslipidemia produces a pro-inflammatory state, associated with diminished NOS and NO production, which produces endothelial dysfunction

    High-Intensity Exercise Reduces Cardiac Fibrosis and Hypertrophy but Does Not Restore the Nitroso-Redox Imbalance in Diabetic Cardiomyopathy

    Get PDF
    Diabetic cardiomyopathy refers to the manifestations in the heart as a result of altered glucose homeostasis, reflected as fibrosis, cellular hypertrophy, increased oxidative stress, and apoptosis, leading to ventricular dysfunction. Since physical exercise has been indicated as cardioprotective, we tested the hypothesis that high-intensity exercise training could reverse the cardiac maladaptations produced by diabetes. For this, diabetes was induced in rats by a single dose of alloxan. Diabetic rats were randomly assigned to a sedentary group or submitted to a program of exercise on a treadmill for 4 weeks at 80% of maximal performance. Another group of normoglycemic rats was used as control. Diabetic rat hearts presented cardiomyocyte hypertrophy and interstitial fibrosis. Chronic exercise reduced both parameters but increased apoptosis. Diabetes increased the myocardial levels of the mRNA and proteins of NADPH oxidases NOX2 and NOX4. These altered levels were not reduced by exercise. Diabetes also increased the level of uncoupled endothelial nitric oxide synthase (eNOS) that was not reversed by exercise. Finally, diabetic rats showed a lower degree of phosphorylated phospholamban and reduced levels of SERCA2 that were not restored by high-intensity exercise. These results suggest that high-intensity chronic exercise was able to reverse remodeling in the diabetic heart but was unable to restore the nitroso-redox imbalance imposed by diabetes

    High-Intensity Exercise Reduces Cardiac Fibrosis and Hypertrophy but Does Not Restore the Nitroso-Redox Imbalance in Diabetic Cardiomyopathy

    Get PDF
    Diabetic cardiomyopathy refers to the manifestations in the heart as a result of altered glucose homeostasis, reflected as fibrosis, cellular hypertrophy, increased oxidative stress, and apoptosis, leading to ventricular dysfunction. Since physical exercise has been indicated as cardioprotective, we tested the hypothesis that high-intensity exercise training could reverse the cardiac maladaptations produced by diabetes. For this, diabetes was induced in rats by a single dose of alloxan. Diabetic rats were randomly assigned to a sedentary group or submitted to a program of exercise on a treadmill for 4 weeks at 80% of maximal performance. Another group of normoglycemic rats was used as control. Diabetic rat hearts presented cardiomyocyte hypertrophy and interstitial fibrosis. Chronic exercise reduced both parameters but increased apoptosis. Diabetes increased the myocardial levels of the mRNA and proteins of NADPH oxidases NOX2 and NOX4. These altered levels were not reduced by exercise. Diabetes also increased the level of uncoupled endothelial nitric oxide synthase (eNOS) that was not reversed by exercise. Finally, diabetic rats showed a lower degree of phosphorylated phospholamban and reduced levels of SERCA2 that were not restored by high-intensity exercise. These results suggest that high-intensity chronic exercise was able to reverse remodeling in the diabetic heart but was unable to restore the nitroso-redox imbalance imposed by diabetes

    Afterword: What\u27s Next? Into a Third Decade of Latcrit Theory, Community, and Praxis

    Get PDF
    In this multi-vocal Afterword, we reflect-personally and collectively to help chart renewed agendas toward and through a third decade of LatCrit theory, community, and praxis. This personal collective exercise illustrates and reconsiders the functions, guideposts, values, and postulates for our shared programmatic work a framework for our daily work as individuals and teams through our portfolio of projects, which in turn emerged as a reflection and projection of LatCrit theory, community and praxis. These early anchors expressly encompassed (1) a call to recognize and accept the inevitable political nature of U.S. legal scholarship; (2) a concomitant call toward anti-subordination praxis to connect theory to action; (3) a commitment to build both intra-Latinx communities and inter-group coalitions; (4) a commitment to find commonalities while respecting difference; (5) a recognition of past critical outsider scholarship in new applications; (6) a commitment to ongoing self-critique, individually and collectively; and (7) a recognition of specificity and diversity in constructing LatCrit theory, praxis, and community. These early guiding commitments were rooted in substantive values, and accompanied by working postulates, that we likewise made explicit to help anchor our programmatic initiatives, and our mutual aspirations, over time and its exigencies

    Afterword: What\u27s Next? Into a Third Decade of Latcrit Theory, Community, and Praxis

    Get PDF
    In this multi-vocal Afterword, we reflect-personally and collectively to help chart renewed agendas toward and through a third decade of LatCrit theory, community, and praxis. This personal collective exercise illustrates and reconsiders the functions, guideposts, values, and postulates for our shared programmatic work a framework for our daily work as individuals and teams through our portfolio of projects, which in turn emerged as a reflection and projection of LatCrit theory, community and praxis. These early anchors expressly encompassed (1) a call to recognize and accept the inevitable political nature of U.S. legal scholarship; (2) a concomitant call toward anti-subordination praxis to connect theory to action; (3) a commitment to build both intra-Latinx communities and inter-group coalitions; (4) a commitment to find commonalities while respecting difference; (5) a recognition of past critical outsider scholarship in new applications; (6) a commitment to ongoing self-critique, individually and collectively; and (7) a recognition of specificity and diversity in constructing LatCrit theory, praxis, and community. These early guiding commitments were rooted in substantive values, and accompanied by working postulates, that we likewise made explicit to help anchor our programmatic initiatives, and our mutual aspirations, over time and its exigencies

    Reducing scattered light in LIGO\u27s third observing run

    Get PDF
    Noise due to scattered light has been a frequent disturbance in the advanced LIGO gravitational wave detectors, hindering the detection of gravitational waves. The non stationary scatter noise caused by low frequency motion can be recognized as arches in the time-frequency plane of the gravitational wave channel. In this paper, we characterize the scattering noise for LIGO and Virgo\u27s third observing run O3 from April, 2019 to March, 2020. We find at least two different populations of scattering noise and we investigate the multiple origins of one of them as well as its mitigation. We find that relative motion between two specific surfaces is strongly correlated with the presence of scattered light and we implement a technique to reduce this motion. We also present an algorithm using a witness channel to identify the times this noise can be present in the detecto

    Fisheries and Oceanography off Galicia, NW Spain: Mesoscale Spatial and Temporal Changes in Physical Processes and Resultant Patterns of Biological Productivity

    Get PDF
    The Galician shelf off NW Spain (43N degrees 9W degrees) exhibits mesoscale spatial and temporal changes in biological productivity associated with upwelling. Spatial heterogeneity results from local geomorphic and land-sea interactions superimposed on the large scale atmospheric processes that produce upwelling. Wind-induced upwelling events, commonly of short (i.e., week) duration, are more common in the summer than in the winter. A Series of cruises, including some time series sampling, and satellite imagery analysis showed that surface upwelling was more common and persistent on the northern coast compared with the western coast off the coastal embayments, the Rias Bajas. Nearshore off the rias, coastal runoff, which is greater in the rainy winter/spring versus the dry summer, affected upwelling. In early summer, upwelling less often reaches the surface because of increased water column stratification associated with lower surface salinities and thus upwelling is not detected by satellite imagery. Conversely, in late summer, upwelling more often reaches the surface because coastal runoff is reduced during the dry summer months and the water column tends to be less stratified. Plankton biomass and rate processes along the Galician shelf reflected both ambient hydrographic conditions as well as prior history of upwelling or downwelling. Phytoplankton and bacterioplankton were in greatest abundance during upwelling conditions (June through August); in contrast, both zooplankton and fish larvae exhibited highest abundances in March, when there were upwelling conditions prior to our cruise. Spatial differences in the duration and frequency of upwelling events, in combination with advection of water masses, are critical to the patterns of water column productivity and sardine fisheries production off the Galician coast. More persistent upwelling at this NW corner of the Iberian peninsula Supports large sardine fisheries because zooplankton and larval fish populations have time to respond to the higher primary production. Farther down the western Galician coast, the episodic upwelling and resultant intermittent primary production does not support a stable food supply needed to support fisheries. Times series sampling revealed mean response times of bacteria, phytoplankton, and zooplankton to be on the order of a day, days, and weeks, respectively. Sardines showed no spawning response in the relatively short time series sampling. The observed distributional patterns of fish eggs and larvae showed some offshore transport of fish larvae that were spawned inshore during upwelling periods and aggregation of larvae in a convergence zone northwest of Cabo Villano
    • …
    corecore