4,723 research outputs found
Supervised Injection Facilities: Legal and Policy Reforms
The US Centers for Disease Control and Prevention reported that more than 70âŻ000 deaths from drug overdoses occurred in 2017, including prescription and illicit opioids, representing a 6-fold increase since 1999. Innovative harm-reduction solutions are imperative. Supervised injection facilities (SIFs) create safe places for drug injection, including overdose prevention, counseling, and treatment referral services. Supervised injection facilities neither provide illicit drugs nor do their personnel inject users. Supervised injection facilities are effective in reducing drug-related mortality, morbidity, and needle-borne infections. Yet their lawfulness remains uncertain. The Department of Justice (DOJ) recently threatened criminal prosecution for SIF operators, medical personnel, and patrons
Monitoring the Low-Energy Gamma-Ray Sky Using Earth Occultation with GLAST GBM
Long term all-sky monitoring of the 20 keV â 2 MeV gamma-ray sky using the Earth occultation technique was demonstrated by the BATSE instrument on the Compton Gamma Ray Observatory. The principles and techniques used for the development of an end-to-end earth occultation data analysis system for BATSE can be extended to the GLAST Burst Monitor (GBM), resulting in multiband light curves and time-resolved spectra in the energy range 8 keV to above 1 MeV for known gamma-ray sources and transient outbursts, as well as the discovery of new sources of gamma-ray emission. In this paper we describe the application of the technique to the GBM. We also present the expected sensitivity for the GBM
COVIDâs Counterpunch: State Legislative Assaults on PublicHealth Emergency Powers
Amid the most impactful health crisis in over a century, COVIDâs âcounterpunchâ entails aggressive efforts by numerous state legislatures to diminish state and local public health emergency powers. It is an incredulous movement facially supported by a need to appropriately balance economic interests and rights with communal health objectives. At its political core, however, is a âpower grabâ by legislatures to free their constituents from extensive emergency powers (e.g., social distancing, assembly limits, and business closures). Never mind the fact that these interventions, when used effectively and constitutionally, save lives and reduce morbidity. Public health agents and activists are understandably concerned about diminutions of their express and discretionary emergency powers. Yet affirmative and strategic uses of existing legal remedies examined in this brief commentary may blunt the impact of these legislative proposals
Expanded Very Large Arrays Observations of a Proto-Cluster of Molecular Gas-Rich Galaxies at z = 4.05
We present observations of the molecular gas in the GN20 proto-cluster of galaxies at z = 4.05 using the Expanded Very Large Array (EVLA). This group of galaxies is the ideal laboratory for studying the formation of massive galaxies via luminous, gas-rich starbursts within 1.6 Gyr of the big bang. We detect three galaxies in the proto-cluster in CO 2-1 emission, with gas masses (H_2) between 10^(10) and 10^(11) Ă (α/0.8) M_â. The emission from the brightest source, GN20, is resolved with a size ~2'' and has a clear north-south velocity gradient, possibly indicating ordered rotation. The gas mass in GN20 is comparable to the stellar mass (1.3 Ă 10^(11) Ă (α/0.8) M_â and 2.3 Ă 10^(11) M_â, respectively), and the sum of gas plus stellar mass is comparable to the dynamical mass of the system (~3.4 Ă 10^(11)[sin (i)/sin (45°)]^(â2) M_â), within a 5 kpc radius. There is also evidence for a tidal tail extending another 2'' north of the galaxy with a narrow velocity dispersion. GN20 may be a massive, gas-rich disk that is gravitationally disturbed, but not completely disrupted. There is one Lyman-break galaxy (BD29079) in the GN20 proto-cluster with an optical spectroscopic redshift within our search volume, and we set a 3Ï limit to the molecular gas mass of this galaxy of 1.1 Ă 10^(10) Ă (α/0.8) M_â
Evidence for a clumpy, rotating gas disk in a submillimeter galaxy at z=4
We present Karl G. Jansky Very Large Array (VLA) observations of the CO(2-1)
emission in the z=4.05 submillimeter galaxy (SMG) GN20. These high-resolution
data allow us to image the molecular gas at 1.3 kpc resolution just 1.6 Gyr
after the Big Bang. The data reveal a clumpy, extended gas reservoir, 14 +/- 4
kpc in diameter, in unprecedented detail. A dynamical analysis shows that the
data are consistent with a rotating disk of total dynamical mass 5.4 +/- 2.4 X
10^11 M_sun. We use this dynamical mass estimate to constrain the CO-to-H_2
mass conversion factor (alpha_CO), finding alpha_CO=1.1 +/- 0.6 M_sun (K km
s^-1 pc^2)^-1. We identify five distinct molecular gas clumps in the disk of
GN20 with masses a few percent of the total gas mass, brightness temperatures
of 16-31K, and surface densities of >3,200-4,500 X (alpha_CO/0.8) M_sun pc^-2.
Virial mass estimates indicate they could be self-gravitating, and we constrain
their CO-to-H_2 mass conversion factor to be <0.2-0.7 M_sun (K km s^-1
pc^2)^-1. A multiwavelength comparison demonstrates that the molecular gas is
concentrated in a region of the galaxy that is heavily obscured in the
rest-frame UV/optical. We investigate the spatially-resolved gas excitation and
find that the CO(6-5)/CO(2-1) ratio is constant with radius, consistent with
star formation occuring over a large portion of the disk. We discuss the
implications of our results in the context of different fueling scenarios for
SMGs.Comment: 15 pages, 9 figures, accepted for publication in Ap
Earth Occultation Imaging of the Low Energy Gamma-Ray Sky with GBM
The Earth Occultation Technique (EOT) has been applied to Fermi's Gamma-ray
Burst Monitor (GBM) to perform all-sky monitoring for a predetermined catalog
of hard X-ray/soft gamma-ray sources. In order to search for sources not in the
catalog, thus completing the catalog and reducing a source of systematic error
in EOT, an imaging method has been developed -- Imaging with a Differential
filter using the Earth Occultation Method (IDEOM). IDEOM is a tomographic
imaging method that takes advantage of the orbital precession of the Fermi
satellite. Using IDEOM, all-sky reconstructions have been generated for ~sim 4
years of GBM data in the 12-50 keV, 50-100 keV and 100-300 keV energy bands in
search of sources otherwise unmodeled by the GBM occultation analysis. IDEOM
analysis resulted in the detection of 57 sources in the 12-50 keV energy band,
23 sources in the 50-100 keV energy band, and 7 sources in the 100-300 keV
energy band. Seventeen sources were not present in the original GBM-EOT catalog
and have now been added. We also present the first joined averaged spectra for
four persistent sources detected by GBM using EOT and by the Large Area
Telescope (LAT) on Fermi: NGC 1275, 3C 273, Cen A, and the Crab
Novel hydrogel system eliminates subculturing and improves retention of nonsenescent mesenchymal stem cell populations
Aim: To compare the physiological behavior of mesenchymal stem/stromal cells (MSCs) within an expandable tissue-mimetic 3D system relative to in vitro expansion in a traditional 2D system.
Methods: Adipose-derived MSCs (ASCs) were continuously cultured for 6 weeks on either 2D culture plastic or in a 3D hydrogel system that eliminated subculturing. ASCs were assessed for senescence, âstem-likeâ MSC markers, and ability for their secretome to augment a secondary cell population.
Results: The 3D hydrogel system resulted in an enhanced retention of more regenerative, nonsenescent ASC populations that exhibited increased expression of âstem-likeâ MSC surface markers.
Conclusion: This study introduces a proof-of-concept design for a novel modular 3D system that can improve in vitro expansion of stem-like cell populations for future regenerative therapies
Tailoring the secretome composition of mesenchymal stem cells to augment specific functions of epidermal regeneration: an in vitro diabetic model
Introduction: Wound healing consists of a dynamic series of events that are highly dependent on paracrine factors for proper progression through the phases of wound healing. Inappropriate progression through the phases is associated with insufficient epidermal regeneration (i.e., re-epithelialization) of wounds and subsequent propagation of chronic wounds, such as diabetic ulcers, which are associated with increased patient morbidity. Recently, investigation into the dynamic secretome of Adipose-derived Mesenchymal Stem Cells (ASCs), have shown promise in augmenting the wound healing response of chronic diabetic wounds. However, currently utilized 2D culture techniques are known to drastically alter the regenerative phenotype of ASCs. In this study a novel tissue-mimetic 3D system was utilized as a means to culture ASCs.
Methods: The capacity for the ASC secretome to augment epidermal regeneration activity was then evaluated after exposure of ASCs to âwound priming stimuliâ in 2D and 3D. The priming stimuli consisted of coating the 2D and 3D systems with the wound matrix proteins, collagen type I, fibronectin, and fibrin. To understand the potential benefit of the ASC secretome in the context of diabetic wounds, keratinocytes (KCs) were exposed to super-physiological glucose levels to induce a diabetic-like phenotype (idKCs).
Results: Relative to KCs, idKC exhibited a 52% and 23% decline in proliferation and migration, respectively. Subsequently, analyses of the ASC secretome were performed. ASC conditioned media (ASC-CM) from tissue-mimetic culture demonstrated aâ>â50% increase secretion of proteins and a 2-fold increase in secreted EVs, relative to 2D culture. Interestingly, the different priming stimuli did not alter the total amount of protein or EVs secreted within the tissue-mimetic system. However, evaluation of specific soluble proteins via ELISA revealed significant differences in key epidermal regeneration factors, such as EGF, IGF-1, FGF-2, MMP-1, TIMP-1, and TGFÎČ-1. Additionally, the relative effect of ASC-EVs from the 2D and 3D system on idKCs epidermal regeneration functionality varied significantly, with EVs from 3D-Collagen culture providing the most significant benefit on idKC activity.
Discussion: Together, these data support the utilization of tissue-mimetic culture system to enhance the adaptability and secretory activity of MSC-like populations in order to generate tailored biologics, via priming stimuli, for specific wound healing applications
NASA rotor system research aircraft flight-test data report: Helicopter and compound configuration
The flight test activities of the Rotor System Research Aircraft (RSRA), NASA 740, from June 30, 1981 to August 5, 1982 are reported. Tests were conducted in both the helicopter and compound configurations. Compound tests reconfirmed the Sikorsky flight envelope except that main rotor blade bending loads reached endurance at a speed about 10 knots lower than previously. Wing incidence changes were made from 0 to 10 deg
WFPC2 Observations of Massive and Compact Young Star Clusters in M31
We present color magnitude diagrams of four blue massive and compact star
clusters in M31: G38, G44, G94, and G293. The diagrams of the four clusters
reveal a well-populated upper main sequence and various numbers of supergiants.
The U-B and B-V colors of the upper main sequence stars are used to determine
reddening estimates of the different lines of sight in the M31 disk. Reddening
values range from E(B-V) = 0.20 +/- 0.10 to 0.31 +/- 0.11. We statistically
remove field stars on the basis of completeness, magnitude and color. Isochrone
fits to the field-subtracted, reddening-corrected diagrams yield age estimates
ranging from 63 +/- 15 Myr to 160 +/- 60 Myr. Implications for the recent
evolution of the disk near NGC 206 are discussed.Comment: 17 pages, Latex, ApJ, in Pres
- âŠ