Opioid misuse is a growing public health concern in the United States (U.S.). This problem continues to claim many lives and has affected the life expectancy of the U.S. population. In the past few ...years, the Black population has witnessed an increased rate of overdose deaths compared to their white counterparts. This review seeks to characterize recent trends in opioid prescription practices and overdose deaths among the Black population in the U.S. An integrative review was conducted with a literature search from CINHAL, MEDLINE, and PsycINFO databases. The literature search identified 11 articles for the analysis. All studies were quantitative. Six studies focused on overdose mortality and five on opioid prescription practices. The results indicate a rising trend in opioid overdose mortality among Black people due to the availability of synthetic opioids on the illegal drug market. Black people receive fewer opioid prescriptions and experience higher rates of opioid dose reduction compared to Whites. The Black population has experienced an increase in opioid overdose mortality compared to the White population within the last two decades. Opioid overdose deaths among Black people are highly associated with the proliferation of synthetic opioids, and Black men have been more affected than Black women. Black people experience lower rates of opioid prescription during E.R. visits compared to Whites. The issue of low opioid prescribing among Black people needs to be addressed since it affects their health outcomes and is a factor that contributes to the use of illicit synthetic opioids.
This article reviews literature on the use of virtual learning environments by highlighting their potential and the challenges of introducing the same in Tanzania. It introduces the concept of ...virtual learning environments by demonstrating their applications to support teaching and learning. The article discusses the use of virtual learning environments in teaching information literacy courses by highlighting the success of using such tools in facilitating the teaching of information literacy courses to library users. In this review, special emphasis is placed on attempts by Tanzanian institutions of higher learning to introduce web-based teaching of information literacy and the challenges faced. The review reveals the need for Tanzanian institutions of higher learning to develop virtual learning environments to facilitate the teaching of information literacy courses to students and faculty so as to reach many of those who may not manage to attend the face-to-face information literacy sessions that are offered by librarians on a regular basis.
Threshold Modernism reveals how changing ideas about gender and race in late nineteenth- and early twentieth-century Britain shaped - and were shaped by - London and its literature. Chapters address ...key sites, especially department stores, women's clubs, and city streets, that coevolved with controversial types of modern women. Interweaving cultural history, narrative theory, close reading, and spatial analysis, Threshold Modernism considers canonical figures such as George Gissing, Henry James, Dorothy Richardson, H. G. Wells, and Virginia Woolf alongside understudied British and colonial writers including Amy Levy, B. M. Malabari, A. B. C. Merriman-Labor, Duse Mohamed Ali, and Una Marson. Evans argues that these diverse authors employed the 'new public women' and their associated spaces to grapple with widespread cultural change and reflect on the struggle to describe new subjects, experiences, and ways of seeing in appropriately novel ways. For colonial writers of color, those women and spaces provided a means through which to claim their own places in imperial London.
The Landau-Lifshitz-Bloch equation is a formulation of dynamic micromagnetics valid at all temperatures, treating both the transverse and longitudinal relaxation components important for ...high-temperature applications. In this paper we discuss two stochastic forms of the Landau-Lifshitz-Bloch equation. Both of them are consistent with the fluctuation-dissipation theorem. We derive the corresponding Fokker-Planck equations and show that only the stochastic form of the Landau-Lifshitz-Bloch equation proposed in the present paper is consistent with the Boltzmann distribution at high temperatures. The previously used form does not satisfy this requirement in the vicinity of the Curie temperature. We discuss the stochastic properties of both equations and present numerical simulations for distribution functions and the average magnetization value as a function of temperature.
Abstract
Magnetic nanoparticles (MNPs) have become increasingly important in biomedical applications like magnetic imaging and hyperthermia based cancer treatment. Understanding their magnetic spin ...configurations is important for optimizing these applications. The measured magnetization of MNPs can be significantly lower than bulk counterparts, often due to canted spins. This has previously been presumed to be a surface effect, where reduced exchange allows spins closest to the nanoparticle surface to deviate locally from collinear structures. We demonstrate that intraparticle effects can induce spin canting throughout a MNP via the Dzyaloshinskii-Moriya interaction (DMI). We study ~7.4 nm diameter, core/shell Fe
3
O
4
/Mn
x
Fe
3−x
O
4
MNPs with a 0.5 nm Mn-ferrite shell. Mössbauer spectroscopy, x-ray absorption spectroscopy and x-ray magnetic circular dichroism are used to determine chemical structure of core and shell. Polarized small angle neutron scattering shows parallel and perpendicular magnetic correlations, suggesting multiparticle coherent spin canting in an applied field. Atomistic simulations reveal the underlying mechanism of the observed spin canting. These show that strong DMI can lead to magnetic frustration within the shell and cause canting of the net particle moment. These results illuminate how core/shell nanoparticle systems can be engineered for spin canting across the whole of the particle, rather than solely at the surface.
Abstract An antiferromagnet emits spin currents when time-reversal symmetry is broken. This is typically achieved by applying an external magnetic field below and above the spin-flop transition or by ...optical pumping. In this work we apply optical pump-THz emission spectroscopy to study picosecond spin pumping from metallic FeRh as a function of temperature. Intriguingly we find that in the low-temperature antiferromagnetic phase the laser pulse induces a large and coherent spin pumping, while not crossing into the ferromagnetic phase. With temperature and magnetic field dependent measurements combined with atomistic spin dynamics simulations we show that the antiferromagnetic spin-lattice is destabilised by the combined action of optical pumping and picosecond spin-biasing by the conduction electron population, which results in spin accumulation. We propose that the amplitude of the effect is inherent to the nature of FeRh, particularly the Rh atoms and their high spin susceptibility. We believe that the principles shown here could be used to produce more effective spin current emitters. Our results also corroborate the work of others showing that the magnetic phase transition begins on a very fast picosecond timescale, but this timescale is often hidden by measurements which are confounded by the slower domain dynamics.
Autotaxin (ATX) is a secreted glycoprotein that converts lysophosphatidylcholine (LPC) to the bioactive phospholipid lysophosphatidic acid (LPA) and is the major enzyme generating circulating LPA. ...Inhibition of LPA signaling has profound antifibrotic effects in multiple organ systems, including lung, kidney, skin, and peritoneum. However, other LPA-generating pathways exist, and the role of ATX in localized tissue LPA production and fibrosis remains unclear and controversial. In this study, we describe the preclinical pharmacologic, pharmacokinetic, and pharmacodynamic properties of a novel small-molecule ATX inhibitor, PAT-505 3-((6-chloro-2-cyclopropyl-1-(1-ethyl-1H-pyrazol-4-yl)-7-fluoro-1H-indol-3-yl) thio)-2-fluorobenzoic acid sodium salt. PAT-505 is a potent, selective, noncompetitive inhibitor that displays significant inhibition of ATX activity in plasma and liver tissue after oral administration. When dosed therapeutically in a Stelic Mouse Animal Model of nonalcoholic steatohepatitis (NASH), PAT-505 treatment resulted in a small but significant improvement in fibrosis with only minor improvements in hepatocellular ballooning and hepatic inflammation. In a choline-deficient, high-fat diet model of NASH, therapeutic treatment with PAT-505 robustly reduced liver fibrosis with no significant effect on steatosis, hepatocellular ballooning, or inflammation. These data demonstrate that inhibiting autotaxin is antifibrotic and may represent a novel therapeutic approach for the treatment of multiple fibrotic liver diseases, including NASH.
Objective We investigated the impact of preoperative pulmonary hypertension (PH) on early and late outcomes after mitral valve operation for mitral regurgitation. Methods Systolic pulmonary artery ...pressure (sPAP) was measured before operation in 873 consecutive patients who underwent mitral valve surgery for mitral regurgitation between January 2002 and January 2010. PH was classified as none (sPAP < 40 mm Hg), mild (40 ≤ sPAP < 50 mm Hg), moderate (50 ≤ sPAP < 60 mm Hg), or severe (sPAP ≥ 60 mm Hg). Results Increased preoperative sPAP was associated with greater left ventricular dysfunction and dilation, left atrial enlargement, more atrial fibrillation, and tricuspid regurgitation. Operative mortality was correlated with the degree of preoperative PH (2%, 3%, 8%, and 12% for none, mild, moderate, and severe PH, respectively, P < .0001). Long-term survival was related to preoperative sPAP (5-year survival: 88%, 79%, 65%, and 53% for none, mild, moderate, and severe PH, respectively; P < .0001). In multivariable analyses, sPAP was a predictor of both operative mortality (odds ratio, 1.023 per 1 mm Hg increase; 95% confidence interval, 1.003–1.044; P = .0270) and late death (hazard ratio, 1.018 per 1 mm Hg increase; 95% confidence interval, 1.007–1.028; P = .001). Among 284 patients with isolated degenerative mitral regurgitation due to leaflet prolapse, actuarial survival was 97.5%, 91.2%, and 80.5% for none, mild, and moderate to severe PH, respectively ( P = .0002). Conclusions Preoperative sPAP is a powerful predictor of early and late survival after mitral valve operation for mitral regurgitation. Even modest increases in sPAP adversely affect outcomes. Mitral valve operation should be performed before the development of PH.
We investigated the cumulative effects of predation by piscivorous colonial waterbirds on the survival of multiple salmonid (Oncorhynchus spp.) populations listed under the U.S. Endangered Species ...Act (ESA) and determined what proportion of all sources of fish mortality (1 -survival) were due to birds in the Columbia River basin, USA. Anadromous juvenile salmonids (smolts) were exposed to predation by Caspian terns (Hydroprogne caspia), double-crested cormorants (Nannopterum auritum), California gulls (Larus californicus), and ring-billed gulls (L. delawarensis), birds known to consume both live and dead fish. Avian consumption and survival probabilities (proportion of available fish consumed or alive) were estimated for steelhead trout (O. mykiss), yearling Chinook salmon (O. tshawytscha), sub-yearling Chinook salmon, and sockeye salmon (O. nerka) during out-migration from the lower Snake River to the Pacific Ocean during an 11-year study period (2008-2018). Results indicated that probabilities of avian consumption varied greatly across salmonid populations, bird species, colony location, river reach, and year. Cumulative consumption probabilities (consumption by birds from all colonies combined) were consistently the highest for steelhead, with annual estimates ranging from 0.22 (95% credible interval = 0.20-0.26) to 0.51 (0.43-0.60) of available smolts. The cumulative effects of avian consumption were significantly lower for yearling and sub-yearling Chinook salmon, with consumption probabilities ranging annually from 0.04 (0.02-0.07) to 0.10 (0.07-0.15) and from 0.06 (0.3-0.09) to 0.15 (0.10-0.23), respectively. Avian consumption probabilities for sockeye salmon smolts was generally higher than for Chinook salmon smolts, but lower than for steelhead smolts, ranging annually from 0.08 (0.03-0.22) to 0.25 (0.14-0.44). Although annual consumption probabilities for birds from certain colonies were more than 0.20 of available smolts, probabilities from other colonies were less than 0.01 of available smolts, indicating that not all colonies of birds posed a substantial risk to smolt mortality. Consumption probabilities were lowest for small colonies and for colonies located a considerable distance from the Snake and Columbia rivers. Total mortality attributed to avian consumption was relatively small for Chinook salmon (less than 10%) but was the single greatest source of mortality for steelhead (greater than 50%) in all years evaluated. Results suggest that the potential benefits to salmonid populations of managing birds to reduce smolt mortality would vary widely depending on the salmonid population, the species of bird, and the size and location of the breeding colony.
ABSTRACT
We predict and compare the distributions and properties of hypervelocity stars (HVSs) ejected from the centres of the Milky Way (MW) and the Large Magellanic Cloud (LMC). In our model, HVSs ...are ejected at a constant rate – equal in both galaxies – via the Hills mechanism and are propagated in a combined potential, where the LMC orbits the MW on its first infall. By selecting $m \gt 2\, \mathrm{M_\odot }$ HVSs well separated from the Magellanic Clouds and Galactic mid-plane, we identify mock HVSs which would stand out from ordinary stars in the stellar halo in future data releases from the Gaia satellite and the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST). We find that in these deep surveys, LMC HVSs will outnumber MW ones by a factor of ∼2.5, as HVSs can more easily escape from the shallower potential of the LMC. At an assumed HVS ejection rate of $10^{-4} \, \mathrm{yr^{-1}}$, HVSs detectable in the final Gaia data release and LSST from the LMC (MW) will number $125_{-12}^{+11}$ ($50_{-8}^{+7}$) and $140_{-11}^{+10}$ ($42_{-7}^{+6}$), respectively. The MW and LMC HVS populations show different kinematics and spatial distributions. While LMC HVSs have more modest total velocities and larger Galactocentric distances clustered around those of the LMC itself, HVSs from the MW show broader distributions, including a prominent high-velocity tail above $500 \, \mathrm{km \ s^{-1}}$ that contains at least half of the stars. These predictions are robust against reasonable variation of the Galactic potential and of the LMC central black hole mass.
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