539 research outputs found

    Heroin Use and Street Gangs

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    A Pair of Compact Red Galaxies at Redshift 2.38, Immersed in a 100 kpc Scale Ly-alpha Nebula

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    We present Hubble Space Telescope (HST) and ground-based observations of a pair of galaxies at redshift 2.38, which are collectively known as 2142-4420 B1 (Francis et al. 1996). The two galaxies are both luminous extremely red objects (EROs), separated by 0.8 arcsec. They are embedded within a 100 kpc scale diffuse Ly-alpha nebula (or blob) of luminosity ~10^44 erg/s. The radial profiles and colors of both red objects are most naturally explained if they are young elliptical galaxies: the most distant yet found. It is not, however, possible to rule out a model in which they are abnormally compact, extremely dusty starbursting disk galaxies. If they are elliptical galaxies, their stellar populations have inferred masses of ~10^11 solar masses and ages of ~7x10^8 years. Both galaxies have color gradients: their centers are significantly bluer than their outer regions. The surface brightness of both galaxies is roughly an order of magnitude greater than would be predicted by the Kormendy relation. A chain of diffuse star formation extending 1 arcsec from the galaxies may be evidence that they are interacting or merging. The Ly-alpha nebula surrounding the galaxies shows apparent velocity substructure of amplitude ~ 700 km/s. We propose that the Ly-alpha emission from this nebula may be produced by fast shocks, powered either by a galactic superwind or by the release of gravitational potential energy.Comment: 33 pages, 9 figures, ApJ in press (to appear in Jun 10 issue

    The Lantern Vol. 41, No. 1, Fall 1974

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    • The Fable • Landscape - Clear Weather in the Valley • Josephine Palooka • Don\u27t Bark Twice - It\u27s All Right • Masks • Suicide Note From a Lemming • The Death of Dame Sexton • Come September • Leaves • Spruce Grove • The Class of \u2775 • The Promise • Images • Sixth Station • Borealis • To Gemhttps://digitalcommons.ursinus.edu/lantern/1105/thumbnail.jp

    Butterfly-parasitoid-hostplant interactions in Western Palaearctic Hesperiidae: a DNA barcoding reference library

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    The study of ecological interactions between plants, phytophagous insects and their natural enemies is an essential but challenging component for understanding ecosystem dynamics. Molecular methods such as DNA barcoding can help elucidate these interactions. In this study, we employed DNA barcoding to establish hostplant and parasitoid interactions with hesperiid butterflies, using a complete reference library for Hesperiidae of continental Europe and north-western Africa (53 species, 100% of those recorded) based on 2934 sequences from 38 countries. A total of 233 hostplant and parasitoid interactions are presented, some recovered by DNA barcoding larval remains or parasitoid cocoons. Combining DNA barcode results with other lines of evidence allowed 94% species-level identification for Hesperiidae, but success was lower for parasitoids, in part due to unresolved taxonomy. Potential cases of cryptic diversity, both in Hesperiidae and Microgastrinae, are discussed. We briefly analyse the resulting interaction networks. Future DNA barcoding initiatives in this region should focus attention on north-western Africa and on parasitoids, because in these cases barcode reference libraries and taxonomy are less well developed.Support for this research was provided by the Spanish National Research Council (CSIC) with a JAE-Intro fellowship for the introduction to research to ETD (reference numbers JAEINT_20_00248 and JAEINT20_EX_0638) and by projects PID2019-107078GB-I00/MCIN/AEI/10.13039/501100011033 and 2017-SGR-991 (Generalitat de Catalunya) to RV, and PID2020-117739GA-I00/MCIN/AEI/10.13039/501100011033 to GT. We thank the Rachadaphiseksomphot Fund, Graduate School, Chulalongkorn University, for the award of a Senior Postdoctoral Fellowship to DLJQ. Further support for this research was provided by the Academy of Finland (Academy Research Fellow, decision no. 328895) to VD. PDNH acknowledges support from Genome Canada through Ontario Genomics. BV has been funded by the CERCA Programme of the Generalitat de Catalunya and by the Grant RYC-22243-2017, whose PI is Josep Sardanyés. SV was supported by the Spanish Ministry of Economy and Competitiveness, grant PID2020-117822GB-I00 MINEICO/AEI/ FEDER and the European Union.INTRODUCTION MATERIAL AND METHODS RESULTS DISCUSSION CONCLUSION SUPPORTING INFORMATION ACKNOWLEDGEMENTS DATA AVAILABILITY REFERENCES Supplementary dat

    Hubble Space Telescope Imaging of Lyman Alpha Emission at z=4.4

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    We present the highest redshift detections of resolved Lyman alpha emission, using Hubble Space Telescope/ACS F658N narrowband-imaging data taken in parallel with the Wide Field Camera 3 Early Release Science program in the GOODS CDF-S. We detect Lyman alpha emission from three spectroscopically confirmed z = 4.4 Lyman alpha emitting galaxies (LAEs), more than doubling the sample of LAEs with resolved Lyman alpha emission. Comparing the light distribution between the rest-frame ultraviolet continuum and narrowband images, we investigate the escape of Lyman alpha photons at high redshift. While our data do not support a positional offset between the Lyman alpha and rest-frame ultraviolet (UV) continuum emission, the half-light radii in two out of the three galaxies are significantly larger in Lyman alpha than in the rest-frame UV continuum. This result is confirmed when comparing object sizes in a stack of all objects in both bands. Additionally, the narrowband flux detected with HST is significantly less than observed in similar filters from the ground. These results together imply that the Lyman alpha emission is not strictly confined to its indigenous star-forming regions. Rather, the Lyman alpha emission is more extended, with the missing HST flux likely existing in a diffuse outer halo. This suggests that the radiative transfer of Lyman alpha photons in high-redshift LAEs is complicated, with the interstellar-medium geometry and/or outflows playing a significant role in galaxies at these redshifts.Comment: Submitted to the Astrophysical Journal. 11 pages, 10 figure

    Whole Earth Telescope Observations of the Helium Interacting Binary PG 1346+082 (CR Bootis)

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    We present our analysis of 240 hr of white-light, high-speed photometry of the dwarf nova-like helium variable PG 1346+082 (CR Boo). We identify two frequencies in the low-state power spectrum, at 679.670 ± 0.004 μHz and 669.887 ± 0.008 μHz. The 679.670 μHz variation is coherent over at least a 2 week time span, the first demonstration of a phase-coherent photometric variation in any dwarf nova-like interacting binary white dwarf system. The high-state power spectrum contains a complex fundamental with a frequency similar, but not identical, to the low-state spectrum, and a series of harmonics not detected in low state. We also uncover an unexpected dependence of the high-frequency power\u27s amplitude and frequency structure on overall system magnitude. We discuss these findings in light of the general AM CVn system model, particularly the implications of the high-order harmonics on future studies of disk structure, mass transfer, and disk viscosity

    Sex Differences in Severe Pulmonary Emphysema

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    Rationale: Limited data on sex differences in advanced COPD are available. Objectives: To compare male and female emphysema patients with severe disease. Methods: One thousand fifty-three patients (38.8% female) evaluated for lung volume reduction surgery as part of the National Emphysema Treatment Trial were analyzed. Measurements and Main Results: Detailed clinical, physiological, and radiological assessment, including quantitation of emphysema severity and distribution from helical chest computed tomography, was completed. In a subgroup (n = 101), airway size and thickness was determined by histological analyses of resected tissue. Women were younger and exhibited a lower bodymass index (BMI), shorter smoking history, less severe airflow obstruction, lower DLCO and arterial PO2, higher arterial PCO2, shorter six-minute walk distance, and lower maximal wattage during oxygen-supplemented cycle ergometry. For a given FEV1% predicted, age, number of packyears, and proportion of emphysema, women experienced greater dyspnea, higher modified BODE, more depression, lower SF-36 mental component score, and lower quality of well-being. Overall emphysema was less severe in women, with the difference from men most evident in the outer peel of the lung. Females had thicker small airway walls relative to luminal perimeters. Conclusions: In patients with severe COPD, women, relative to men, exhibit anatomically smaller airway lumens with disproportionately thicker airway walls, and emphysema that is less extensive and characterized by smaller hole size and less peripheral involvement.The National Emphysema Treatment Trial (NETT) was supported by contracts with the National Heart, Lung, and Blood Institute (N01HR76101, N01HR76102, N01HR76103, N01HR76104, N01HR76105, N01HR76106, N01HR76107, N01HR76108, N01HR76109, N01HR76110, N01HR76111, N01HR76112, N01HR76113, N01HR76114, N01HR76115, N01HR76116, N01HR76118, and N01HR76119); the Centers for Medicare and Medicaid Services (CMS; formerly the Health Care Financing Administration); and the Agency for Healthcare Research and Quality (AHRQ). J.L.C. is supported by funding from a Research Enhancement Award Program (REAP) from the Biomedical Laboratory Research & Development Service, Department of Veterans Affairs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91968/1/2007 Martinez AJRCCM Sex Differences in Empy.pd

    Growth hormone secretagogue increases muscle strength during immobilization after canine hindlimb immobilization

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    Summary: Twenty-two beagles were divided into two equal groups, and the right hindlimb of each animal was immobilized at 105" of knee flexion by external fixation. After 10 weeks of fixation, the device was removed, allowing free mobility for the following 5 weeks. Each day throughout the 1. 5 weeks, one group received a growth hormone secretagogue (treatment) at a dose of 5 mg/kg, and the other received a lactose placebo (control). A t weeks 0, 10, and 15, strength as indicated by maximum isometric extension torque was measured in the right hindlimb, biopsies of the vastus lateralis muscle were taken, and the dogs were weighed. Weekly blood samples were analyzed for insulin-like growth factor-1, blood urea nitrogen, and creatine phosphokinase. Between weeks 0 and 10, tetanic torque declined by about 60% (p < 0.001) in both groups, with no significant difference between the groups (p > 0.7). Between weeks 10 and 15, tetanic torque in the treated group increased by 0.81 Nm; this was significantly greater than the increase of 0.25 Nm in the placebo group (p < 0.05). The diameters of slow (type-1) and fast (type-2) fibers measured from the vastus lateralis muscle followed the same trend. At all time points, fiber diameter correlated strongly with torque; this argues against nonmuscular causes such as nerve injury for strength loss. The mean levels of insulin-like growth factor-1 increased 100% by week 4 in the treated group and remained elevated by about 60% throughout the experiment. Levels of insulin-like growth factor-1 in the placebo group decreased 30% within week 1 and remained depressed throughout the experiment. Our interpretation of these data suggests that the growth hormone secretagogue elevated levels of serum insulin-like growth factor-1, which in turn increased the size and strength of the quadriceps muscle during remobilization. These data may ultimately have therapeutic application to humans during rehabilitation after prolonged inactivity. - The strengthening of skeletal muscle after surgery or prolonged disuse remains a primary goal of rehabilitation. Many approaches -including electrical stimulation (lo), voluntary exercise (15), continuous passive motion (7), and hormone therapy (32) -have been used to strengthen atrophied muscles. In some cases, treatment modalities are limited by a patient's access to rehabilitation professionals or rehabilitation devices. Medical treatment of muscle atrophy with hormone therapy offers the advantage of requiring relatively little effort on the part of the patient to achieve the desired therapeutic result. There is ample evidence of hypertrophy of skeletal muscle in response to anabolic steroids. strong correlations were demonstrated between muscle strength and serum testosterone concentration in elderly men in whom a marked loss of muscle function was correlated with low testosterone levels relative to stronger age-matched controls (1). In related studies, the administration of testosterone to elderly men (to increase serum testosterone to a range observed in younger men) increased lean body mass (32) and grip strength (25). The effect of this hormone may be mediated, at least in part, by serum insulin-like growth factor-1 (IGF-1) (4). The anabolic effects on humans of I G F -1 administration have been well documented. For example, recombinant IGF-1 attenuated the catabolic effects of glucocorticoids (23) and increased muscle protein synthesis in young men (9). Similar results were obtained in vitro with other muscle growth factors such as fibroblast growth factor (FGF). At the cellular level, skeletal muscle myotubes grown in culture in the presence of FGF demonstrated a marked increase in protein synthesis. This effect was enhanced 51
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