279 research outputs found
Economic Impacts of Aquatic Vegetation to Angling in Two South Carolina Reservoirs
Angler creel surveys and economic impact models were
used to evaluate potential expansion of aquatic vegetation in
Lakes Murray and Moultrie, South Carolina. (PDF contains 4 pages.
Development of an Oral Form of Azacytidine: 2′3′5′Triacetyl-5-Azacytidine
Myelodysplastic syndromes (MDSs) represent a group of incurable stem-cell malignancies which are predominantly treated by supportive care. Epigenetic silencing through promoter methylation of a number of genes is present in poor-risk subtypes of MDS and often predicts transformation to acute myelogenous leukemia (AML). Azacitidine and decitabine, two FDA-approved DNA methyltransferase (DNMT) inhibitors, are able to improve overall response although their oral bioavailability complicates their clinical use. This study evaluated 2′, 3′, 5′-triacetyl-5-azacitidine (TAC) as a potential prodrug for azacitidine. The prodrug demonstrated significant pharmacokinetic improvements in bioavailability, solubility, and stability over the parent compound. In vivo analyses indicated a lack of general toxicity coupled with significantly improved survival. Pharmacodynamic analyses confirmed its ability to suppress global methylation in vivo. These data indicate that esterified nucleoside derivatives may be effective prodrugs for azacitidine and encourages further investigation of TAC into its metabolism, activity, and possible clinical evaluation
Application of the levitation technique for investigation of metal alloys and phase equilibria in slags
Experimental methods, based on electromagnetic levitation, have been developed for preparation and investigation of copper-rich alloys, and for the determination of oxide-metal phase equilibria. These techniques involve high-temperature equilibration, rapid quenching and chemical analysis of the phases using electron probe X-ray microanalysis. The experiments can be carried out in the temperature range 1373-1873 K (= 1100 degrees C-1600 degrees C). A developed calibration method, using phase equilibria data in known oxide systems, was applied for pyrometric temperature measurements. Described methods of the application of the electro-magnetic levitations were used for in-situ formation of Cu-based alloys and for formation of Ca-ferrite slags equilibrated with metallic copper
A novel cellular pathway of antigen presentation and CD4 T cell activation in vivo
Dendritic cell activation of CD4 T cells in the lymph node draining a site of infection or vaccination is widely considered the central event in initiating adaptive immunity. The accepted dogma is that this occurs by stimulating local activation and antigen acquisition by dendritic cells, with subsequent lymph node migration, however the generalizability of this mechanism is unclear. Here we show that in some circumstances antigen can bypass the injection site inflammatory response, draining freely and rapidly to the lymph nodes where it interacts with subcapsular sinus (SCS) macrophages resulting in their death. Debris from these dying SCS macrophages is internalized by monocytes recruited from the circulation. This coordinated response leads to antigen presentation by monocytes and interactions with naïve CD4 T cells that can drive the initiation of T cell and B cell responses. These studies demonstrate an entirely novel pathway leading to initiation of adaptive immune responses in vivo
Effectiveness of Personal Protective Measures to Prevent Lyme Disease
Use of protective clothing and tick repellents on the skin or clothing while outdoors is 40% and 20% effective, respectively
Laser-initiated decomposition products of indocyanine green (ICG) and carbon black sensitized biological tissues
Organic dyes have found increasing use a s sensitizers in laser surgical procedures, due to their high optical absorbances. Little is known, however, about the nature of the degradation products formed when these dyes are irradiated with a laser. Previous work in our laboratories has shown that irradiation of polymeric and biological tissues with CO2 and Nd:YAG lasers produces a host of volatile and semivolatile by-products, some of which are known to be potential carcinogens. This work focuses on the identification of the chemical by-products formed by diode laser and Nd:YAG laser irradiation of indocyanine green (ICG) and carbon black based ink sensitized tissues, including bone, tendon and sheep\u27s teeth. Samples were mounted in a 0.5-L Pyrex sample chamber equipped with quartz optical windows, charcoal filtered air inlet and an outlet attached to an appropriate sample trap and a constant flow pump. By-products were analyzed by GC/MS and HPLC. Volatiles identified included benzene and formaldehyde. Semi-volatiles included traces of polycyclic aromatics, arising from the biological matrix and inks, as well as fragments of ICG and the carbon ink components. The significance of these results will be discussed, including the necessity of using appropriate evacuation devices when utilizing lasers for surgical procedures
Yard-Sale exchange on networks: Wealth sharing and wealth appropriation
Yard-Sale (YS) is a stochastic multiplicative wealth-exchange model with two
phases: a stable one where wealth is shared, and an unstable one where wealth
condenses onto one agent. YS is here studied numerically on 1d rings, 2d square
lattices, and random graphs with variable average coordination, comparing its
properties with those in mean field (MF). Equilibrium properties in the stable
phase are almost unaffected by the introduction of a network. Measurement of
decorrelation times in the stable phase allow us to determine the critical
interface with very good precision, and it turns out to be the same, for all
networks analyzed, as the one that can be analytically derived in MF. In the
unstable phase, on the other hand, dynamical as well as asymptotic properties
are strongly network-dependent. Wealth no longer condenses on a single agent,
as in MF, but onto an extensive set of agents, the properties of which depend
on the network. Connections with previous studies of coalescence of immobile
reactants are discussed, and their analytic predictions are successfully
compared with our numerical results.Comment: 10 pages, 7 figures. Submitted to JSTA
Discovery of a new Local Group Dwarf Galaxy Candidate in UNIONS: Bo\"otes V
We present the discovery of Bo\"otes V, a new ultra-faint dwarf galaxy
candidate. This satellite is detected as a resolved overdensity of stars during
an ongoing search for new Local Group dwarf galaxy candidates in the UNIONS
photometric dataset. It has a physical half-light radius of
26.9 pc, a -band magnitude of 4.5 0.4 mag, and
resides at a heliocentric distance of approximately 100 kpc. We use Gaia DR3
astrometry to identify member stars, characterize the systemic proper motion,
and confirm the reality of this faint stellar system. The brightest star in
this system was followed up using Gemini GMOS-N long-slit spectroscopy and is
measured to have a metallicity of [Fe/H] 2.85 0.10 dex and a
heliocentric radial velocity of = 5.1 13.4 km s. Bo\"otes V
is larger (in terms of scale radius), more distant, and more metal-poor than
the vast majority of globular clusters. It is likely that Bo\"otes V is an
ultra-faint dwarf galaxy, though future spectroscopic studies will be necessary
to definitively classify this object.Comment: 13 pages, 7 figures, 3 tables. Accepted for publication in the AAS
Journals. Please note that this paper was submitted in coordination with the
work of William Cerny et al. 2022. These authors independently discovered
this same satellite so our two research groups have coordinated the
submission of these discovery paper
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