4,430 research outputs found
Strategies Employed by Community-Based Service Providers to Address HIV-Associated Neurocognitive Challenges: A Qualitative Study
Background: HIV-associated neurocognitive disorders and other causes of neurocognitive challenges experienced by people living with HIV (PLWH) persist as public health concerns in developed countries. Consequently, PLWH who experience neurocognitive challenges increasingly require social support and mental health services from community-based providers in the HIV sector. Methods: Thirty-three providers from 22 AIDS service organizations across Ontario, Canada, were interviewed to determine the strategies they used to support PLWH experiencing neurocognitive difficulties. Thematic analysis was conducted to determine key themes from the interview data. Results: Three types of strategies were identified: (a) intrapersonal, (b) interpersonal, and (c) organizational. Intrapersonal strategies involved learning and staying informed about causes of neurocognitive challenges. Interpersonal strategies included providing practical assistance, information, counseling, and/or referrals to PLWH. Organizational strategies included creating dedicated support groups for PLWH experiencing neurocognitive challenges, partnering with other organizations with services not available within their own organization, and advocating for greater access to services with expertise and experience working with PLWH. Conclusion: Through concerted efforts in the future, it is likely that empirically investigating, developing, and customizing these strategies specifically to address HIV-associated neurocognitive challenges will yield improved social support and mental health outcomes for PLWH
Electric field inside a "Rossky cavity" in uniformly polarized water
Electric field produced inside a solute by a uniformly polarized liquid is
strongly affected by dipolar polarization of the liquid at the interface. We
show, by numerical simulations, that the electric "cavity" field inside a
hydrated non-polar solute does not follow the predictions of standard Maxwell's
electrostatics of dielectrics. Instead, the field inside the solute tends, with
increasing solute size, to the limit predicted by the Lorentz virtual cavity.
The standard paradigm fails because of its reliance on the surface charge
density at the dielectric interface determined by the boundary conditions of
the Maxwell dielectric. The interface of a polar liquid instead carries a
preferential in-plane orientation of the surface dipoles thus producing
virtually no surface charge. The resulting boundary conditions for
electrostatic problems differ from the traditional recipes, affecting the
microscopic and macroscopic fields based on them. We show that relatively small
differences in cavity fields propagate into significant differences in the
dielectric constant of an ideal mixture. The slope of the dielectric increment
of the mixture versus the solute concentration depends strongly on which
polarization scenario at the interface is realized. A much steeper slope found
in the case of Lorentz polarization also implies a higher free energy penalty
for polarizing such mixtures.Comment: 9 pages, 8 figure
Design of a Direct-Detection Wind and Aerosol Lidar for Mars Orbit
The present knowledge of the Mars atmosphere is greatly limited by a lack of global measurements of winds and aerosols. Hence, measurements of height-resolved wind and aerosol profiles are a priority for new Mars orbiting missions. We have designed a direct-detection lidar (MARLI) to provide global measurements of dust, winds and water ice profiles from Mars orbit. From a 400-km polar orbit, the instrument is designed to provide wind and backscatter measurements with a vertical resolution of 2 km and with resolution of 2 in latitude along track. The instrument uses a single-frequency, seeded Nd:YAG laser that emits 4 mJ pulses at 1064 nm at a 250 Hz pulse rate. The receiver utilizes a 50-cm diameter telescope and a double edge Fabry-Prot etalon as a frequency discriminator to measure the Doppler shift of the aerosol-backscatter profiles. The receiver also includes a polarization-sensitive channel to detect the cross-polarized backscatter profiles from water ice. The receiver uses a sensitive 4 4 pixel HgCdTe avalanche photodiode array as a detector for all signals. Here we describe the measurement concept, instrument design, and calculate its performance for several cases of Mars atmospheric conditions. The calculations show that under a range of atmospheric conditions MARLI is capable of measuring wind speed profiles with random error of 24 m/s within the first three scale heights, enabling vertically resolved mapping of transport processes in this important region of the atmosphere
OdreÄivanje duĆŸine korijenskog kanala: procjena CDRÂź intraoralnog radiografskog sustava in vivo
The Computed Dental Radiolography SystemÂź (CDR: Schick Technologies, Long Island City, NY) is a CCD-based digital intraoral radiographic device which possesses a measurement software algorithm that can be adjusted with respect to an object of known dimension. This âcalibration â algorithm was compared to the CDRÂź preset mode and analog film using 30 root canals in vivo. The three measurement methods differed significantly from each other for 40% o f the canals sampled. Two o f the three differed significantly for 50% o f canals. No difference existed between the methods for 10% o f the canals. Estimates of tooth length using the calibrated mode differed from those obtained using a conventional radiographic technique by an average o f 1.2 mm, while those using the calibrated mode differed by 1.9 mm. The 1.2 mm average for the calibrated CDRÂź was judged to be an acceptable degree o f clinical error for most root canal procedures and indicates that the calibration function of the CDRÂź system should be used when measuring endodontic working lengths. The results demonstrated that calibration to a 15 mm probe when using the Schick CDRÂź system is more consistent with a comparable measurement, if film is used as the âgold standardâ, than are measurements of the tooth length using the CDRÂź without calibration.Sustav "Kompjuterizirane dentalne radiografije" (CDR: Schick Technologies. Long Island City. NY) je na CDD-u zasnovan ureÄaj za digitalnu intraoralnu radio grafiju koji posjeduje "Software-ski algoritam" za mjerenja koji se moĆŸe prilagoditi prema objektu poznate veliÄine. Ovaj "kalibracijski" algoritam usporeÄen je sa sustavom CDR (kompjutorizirane dentalne radiografije) bez mjernog algoritma i analognim filmom rabeÄi 30 korijenskih kanala in vivo. Tri postupka mjerenja znaÄajno su se razlikovali u 40% mjerenih korijenskih kanala. Dva od tri postupka razlikovala su se u 50% mjerenih kanala. Nikakve razlike izmeÄu postupaka nije bilo u 10% mjerenih korijenskih kanala. Procjena duljine zuba koriĆĄtenjem kalibriranog naÄina razlikovala se od procjene dobivene konvencionalnom (analognom) radio grafskom tehnikom za otprilike 1,2 mm, dok se od digitalnog sustava bez mjernog algoritma razlikovala za prosjeÄno 1,9 mm. Razlika od 1,2 mm za "kalibrirani
CDR" se procjenjuje kao prihvatljiva kliniÄka greĆĄka za veÄinu endodontskih postupaka i ukazuje da bi se "kalibracijski sustav CDRa" trebao rabiti pri mjerenju radne duljine korijenskog kanala. Rezultati ukazuju da je kalibracija sonde do 15 mm kad se rabi Schch-ov CDR sustav postojanija s usporednim mjerenjem ako se film koji se mjeri uzme kao "zlatni standard", nego je mjerenje duljine CDR sustavom bez kalibracije
Gauging the effect of supermassive black holes feedback on quasar host galaxies
In order to gauge the role that active galactic nuclei play in the evolution of galaxies via the effect of kinetic feedback in nearby QSOâ2âs (z ⌠0.3), we observed eight such objects with bolometric luminosities LbolâŒ1046ergsâ1 using Gemini Multi-Object Spectrograph-integral field units. The emission lines were fitted with at least two Gaussian curves, the broadest of which we attributed to gas kinetically disturbed by an outflow. We found that the maximum extent of the outflow ranges from âŒ1 to 8âkpc, being âŒ0.5±0.3 times the extent of the [OIII] ionized gas region. Our âdefaultâ assumptions for the gas density (obtained from the [SII] doublet) and outflow velocities resulted in peak mass outflow rates of MËdefoutâŒâ3â30âMâyrâ1 and outflow power of EËdefoutâŒ1041â1043ergsâ1â . The corresponding kinetic coupling efficiencies are Δdeff=EËdefout/LbolâŒ7Ă10â4â0.5âperâcent, with the average efficiency being only 0.06âperâcent (0.01âperâcent median), implying little feedback powers from ionized gas outflows in the host galaxies. We investigated the effects of varying assumptions and calculations on MËout and EËout regarding the ionized gas densities, velocities, masses, and inclinations of the outflow relative to the plane of the sky, resulting in average uncertainties of 1âdex. In particular, we found that better indicators of the [OIII] emitting gas density than the default [SII] line ratio, such as the [ArIV]âλλ4711,40 line ratio, result in almost an order of magnitude decrease in the Δf
Recommended from our members
Feasibility Evaluation and Retrofit Plan for Cold Crucible Induction Melter Deployment in the Defense Waste Processing Facility at Savannah River Site 8118
Cold crucible induction melters (CCIM) have been proposed as an alternative technology for waste glass melting at the Defense Waste Processing Facility (DWPF) at Savannah River Site (SRS) as well as for other waste vitrification facilities. Proponents of this technology cite high temperature operation, high tolerance for noble metals and aluminum, high waste loading, high throughput capacity, and low equipment cost as the advantages over existing Joule Heated Melter (JHM) technology. The CCIM uses induction heating to maintain molten glass at high temperature. A water-cooled helical induction coil is connected to an AC current supply, typically operating at frequencies from 100 KHz to 5 MHz. The oscillating magnetic field generated by the oscillating current flow through the coil induces eddy currents in conductive materials within the coil. Those oscillating eddy currents, in turn, generate heat in the material. In the CCIM, the induction coil surrounds a 'Cold Crucible' which is formed by metal tubes, typically copper or stainless steel. The tubes are constructed such that the magnetic field does not couple with the crucible. Therefore, the field generated by the induction coil couples primarily with the conductive medium (hot glass) within. The crucible tubes are water cooled to maintain their temperature between 100 C to 200 C so that a protective layer of molten glass and/or batch material, referred to as a 'skull', forms between them and the hot, corrosive melt. Because the protective skull is the only material directly in contact with the molten glass, the CCIM doesn't have the temperature limitations of traditional refractory lined JHM. It can be operated at melt temperatures in excess of 2000 C, allowing processing of high waste loading batches and difficult-to-melt compounds. The CCIM is poured through a bottom drain, typically through a water-cooled slide valve that starts and stops the pour stream. To promote uniform temperature distribution and increase heat transfer to the slurry fed High Level Waste (HLW) sludge, the CCIM may be equipped with bubblers and/or water cooled mechanical agitators. The DWPF could benefit from use of CCIM technology, especially in light of our latest projections of waste volume to be vitrified. Increased waste loading and increased throughput could result in substantial life cycle cost reduction. In order to significantly surpass the waste throughput capability of the currently installed JHM, it may be necessary to install two 950 mm CCIMs in the DWPF Melt Cell. A cursory evaluation of system design requirements and modifications to the facility that may be required to support installation and operation of two 950 mm CCIMs was performed. Based on this evaluation, it appears technically feasible to position two CCIMs in the Melt Cell of the DWPF within the existing footprint of the current melter. Interfaces with support systems and controls including Melter Feed, Power, Melter Cooling Water, Melter Off-gas, and Canister Operations must be designed to support dual CCIM operations. This paper describes the CCIM technology and identifies technical challenges that must be addressed in order to implement CCIMs in the DWPF
Self-driving Multimodal Studies at User Facilities
Multimodal characterization is commonly required for understanding materials.
User facilities possess the infrastructure to perform these measurements,
albeit in serial over days to months. In this paper, we describe a unified
multimodal measurement of a single sample library at distant instruments,
driven by a concert of distributed agents that use analysis from each modality
to inform the direction of the other in real time. Powered by the Bluesky
project at the National Synchrotron Light Source II, this experiment is a
world's first for beamline science, and provides a blueprint for future
approaches to multimodal and multifidelity experiments at user facilities.Comment: 36th Conference on Neural Information Processing Systems (NeurIPS
2022). AI4Mat Worksho
Corporate Security Responsibility: Towards a Conceptual Framework for a Comparative Research Agenda
The political debate about the role of business in armed conflicts has increasingly raised expectations as to governance contributions by private corporations in the fields of conflict prevention, peace-keeping and postconflict peace-building. This political agenda seems far ahead of the research agenda, in which the negative image of business in conflicts, seen as fuelling, prolonging and taking commercial advantage of violent conflicts,still prevails. So far the scientific community has been reluctant to extend the scope of research on âcorporate social responsibilityâ to the area of security in general and to intra-state armed conflicts in particular. As a consequence, there is no basis from which systematic knowledge can be generated about the conditions and the extent to which private corporations can fulfil the role expected of them in the political discourse. The research on positive contributions of private corporations to security amounts to unconnected in-depth case studies of specific corporations in specific conflict settings. Given this state of research, we develop a framework for a comparative research agenda to address the question: Under which circumstances and to what extent can private corporations be expected to contribute to public security
- âŠ