350 research outputs found
An optical spectroscopic H-R diagram for low-mass stars and brown dwarfs in Orion
The masses and temperatures of young low mass stars and brown dwarfs in star-
forming regions are not yet well established because of uncertainties in the
age of individual objects and the spectral type vs. temperature scale
appropriate for objects with ages of only a few Myr. Using multi-object optical
spectroscopy, 45 low-mass stars and brown dwarfs in the Trapezium Cluster in
Orion have been classified and 44 of these confirmed as bona fide cluster
members. The spectral types obtained have been converted to effective
temperatures using a temperature scale intermediate between those of dwarfs and
giants, which is suitable for young pre-main sequence objects. The objects have
been placed on an H-R diagram overlaid with theoretical isochrones. The low
mass stars and the higher mass substellar objects are found to be clustered
around the 1 Myr isochrone, while many of the lower mass substellar objects are
located well above this isochrone. An average age of 1 Myr is found for the
majority of the objects. Assuming coevality of the sources and an average age
of 1 Myr, the masses of the objects have been estimated and range from 0.018 to
0.44Msun. The spectra also allow an investigation of the surface gravity of the
objects by measurement of the sodium doublet equivalent width. With one
possible exception, all objects have low gravities, in line with young ages,
and the Na indices for the Trapezium objects lie systematically below those of
young stars and brown dwarfs in Chamaeleon, suggesting that the 820 nm Na index
may provide a sensitive means of estimating ages in young clusters.Comment: 19 pages, accepted by MNRA
Toward actionable practice parameters for dual diagnosis : Principles of assessment and management for co-occurring psychiatric and intellectual/developmental disability
PURPOSE OF REVIEW: Although treatment algorithms and parameters for best practice are readily available for all major syndromes of psychiatric impairment, the occurrence of psychiatric syndromes in individuals with intellectual and developmental disability (IDD) invokes serious contextual challenges for interpretation of symptoms, diagnosis, and optimization of treatment, both for clinicians and for the service sectors in which care and support of individuals with IDD are delivered. Recognizing that there exist very few definitive resources for best practice under the circumstance of this form of dual diagnosis, the Missouri Department of Mental Health convened an expert panel to conduct a focused review and synthesis of the relevant scientific literature from which to develop guidance in the form of decision support to clinicians. This article summarizes the findings for three of the most common and impairing clusters of psychiatric symptoms that co-occur with IDD-aggression, depression, and addictions.
RECENT FINDINGS: Individuals with IDD are at high risk for the development of psychiatric symptoms (PS), which often manifest uniquely in IDD and for which evidence for effective intervention is steadily accruing. Interventions that are commonly implemented in the IDD service sector (e.g., functional communication training and positive behavioral support planning) are capable of mitigating severe behavioral impairment, yet rarely invoked when dual diagnosis patients are seen in the psychiatric service sector. Conversely, state-of-the-art interventions for traumatic stress, pharmacotherapy, and psychotherapy have proven capable of improving behavioral impairments in IDD but are typically restricted to the psychiatric service sector, where there exist significant barriers to access for patients with IDD, including limitations imposed by diagnostic eligibility and practitioner experience. Bridging these gaps in knowledge and clinical capacity across the respective IDD and PS service sectors should be of very high priority in strategizing the care and support of IDD patients with serious co-occurring psychiatric conditions
Viral Transduction of Human Rod Opsin or Channelrhodopsin Variants to Mouse ON Bipolar Cells Does Not Impact Retinal Anatomy or Cause Measurable Death in the Targeted Cells
From MDPI via Jisc Publications RouterHistory: accepted 2021-12-01, pub-electronic 2021-12-03Publication status: PublishedFunder: Fight for Sight; Grant(s): 5047/5048Funder: Medical Research Council; Grant(s): MR/N012992/1, MR/S026266/1The viral gene delivery of optogenetic actuators to the surviving inner retina has been proposed as a strategy for restoring vision in advanced retinal degeneration. We investigated the safety of ectopic expression of human rod opsin (hRHO), and two channelrhodopsins (enhanced sensitivity CoChR-3M and red-shifted ReaChR) by viral gene delivery in ON bipolar cells of the mouse retina. Adult Grm6Cre mice were bred to be retinally degenerate or non-retinally degenerate (homozygous and heterozygous for the rd1Pde6b mutation, respectively) and intravitreally injected with recombinant adeno-associated virus AAV2/2(quad Y-F) serotype containing a double-floxed inverted transgene comprising one of the opsins of interest under a CMV promoter. None of the opsins investigated caused changes in retinal thickness; induced apoptosis in the retina or in transgene expressing cells; or reduced expression of PKCα (a specific bipolar cell marker). No increase in retinal inflammation at the level of gene expression (IBA1/AIF1) was found within the treated mice compared to controls. The expression of hRHO, CoChR or ReaChR under a strong constitutive promoter in retinal ON bipolar cells following intravitreal delivery via AAV2 does not cause either gross changes in retinal health, or have a measurable impact on the survival of targeted cells
Transformations between 2MASS, SDSS and BVI photometric systems for late-type giants
We present colour transformations from Two Micron All Sky Survey (2MASS)
photometric system to Johnson-Cousins system and to Sloan Digital Sky Survey
(SDSS) system for late-type giants and vice versa. The giant star sample was
formed using surface gravity constraints () to Cayrel de
Strobel et al.\rq s (2001) spectroscopic catalogue. 2MASS, SDSS and
Johnson-Cousins photometric data was taken from Cutri et al. (2003), Ofek
(2008) and van Leeuwen (2007), respectively. The final sample was refined
applying the following steps: (1) the data were dereddened, (2) the sample
stars selected are of the highest photometric quality. We give two--colour
dependent transformations as a function of metallicity as well as independent
of metallicity. The transformations provide absolute magnitudes and distance
determinations which can be used in space density evaluations at relatively
short distances where some or all of the SDSS magnitudes of late-type giants
are saturated.Comment: The variables and "f" parameters in the equations 15-17 and 27-29
were change
Extraocular, rod-like photoreceptors in a flatworm express xenopsin photopigment
Animals detect light using opsin photopigments. Xenopsin, a recently classified subtype of opsin, challenges our views on opsin and photoreceptor evolution. Originally thought to belong to the Gαi-coupled ciliary opsins, xenopsins are now understood to have diverged from ciliary opsins in pre-bilaterian times, but little is known about the cells that deploy these proteins, or if they form a photopigment and drive phototransduction. We characterized xenopsin in a flatworm, Maritigrella crozieri, and found it expressed in ciliary cells of eyes in the larva, and in extraocular cells around the brain in the adult. These extraocular cells house hundreds of cilia in an intra-cellular vacuole (phaosome). Functional assays in human cells show Maritigrella xenopsin drives phototransduction primarily by coupling to Gαi. These findings highlight similarities between xenopsin and c-opsin and reveal a novel type of opsin-expressing cell that, like jawed vertebrate rods, encloses the ciliary membrane within their own plasma membrane
Deuterated formaldehyde in rho Ophiuchi A
From mapping observations of H2CO, HDCO, and D2CO, we have determined how the
degree of deuterium fractionation changes over the central 3'x3' region of rho
Oph A. The multi-transition data of the various H2CO isotopologues, as well as
from other molecules (e.g., CH3OH and N2D+) present in the observed bands, were
analysed using both the standard type rotation diagram analysis and, in
selected cases, a more elaborate method of solving the radiative transfer for
optically thick emission. In addition to molecular column densities, the
analysis also estimates the kinetic temperature and H2 density. Toward the SM1
core in rho Oph A, the H2CO deuterium fractionation is very high. In fact, the
observed D2CO/HDCO ratio is 1.34+/-0.19, while the HDCO/H2CO ratio is
0.107+/-0.015. This is the first time, to our knowledge, that the D2CO/HDCO
abundance ratio is observed to be greater than 1. The kinetic temperature is in
the range 20-30 K in the cores of rho Oph A, and the H2 density is (6-10)x10^5
cm-3. We estimate that the total H2 column density toward the deuterium peak is
(1-4)x10^23 cm-2. As depleted gas-phase chemistry is not adequate, we suggest
that grain chemistry, possibly due to abstraction and exchange reactions along
the reaction chain H2CO -> HDCO -> D2CO, is at work to produce the very high
deuterium levels observed.Comment: 17 pages, 11 figures, accepted for publication in Astronomy &
Astrophysic
The discovery of an M4+T8.5 binary system
The original article can be found at: http://www3.interscience.wiley.com Copyright Blackwell Publishing / Royal Astronomical Society. DOI: 10.1111/j.1365-2966.2009.14620.xWe report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. [Please see original online abstract for complete version with correct notation]Peer reviewe
Selection for Forage and Avoidance of Risk by Woodland Caribou (Rangifer Tarandus Caribou) at Coarse andLocal Scales
The relationship between selection at coarse and fine spatiotemporal spatial scales is still poorly understood. Some authors claim that, to accommodate different needs at different scales, individuals should have contrasting selection patterns at different scales of selection, while others claim that coarse scale selection patterns should reflect fine scale selection decisions. Here we examine site selection by 110 woodland caribou equipped with GPS radio‐collars with respect to forage availability and predation risk across a broad gradient in availability of both variables in boreal forests of Northern Ontario. We tested whether caribou selection for forage and avoidance of risk was consistent between coarse (seasonal home range) and fine scales of selection. We found that local selection patterns predicted coarse scale selection patterns, indicating a close relationship between the drivers of selection at both spatial scales
Landscape-Level Wolf Space Use is Correlated With Prey Abundance, Ease of Mobility and the Distribution of Prey Habitat
Predator space use influences ecosystem dynamics, and a fundamental goal assumed for a foraging predator is to maximize encounter rate with prey. This can be achieved by disproportionately utilizing areas of high prey density or, where prey are mobile and therefore spatially unpredictable, utilizing patches of their prey\u27s preferred resources. A third, potentially complementary strategy is to increase mobility by using linear features like roads and/or frozen waterways. Here, we used novel population-level predator utilization distributions (termed localized density distributions ) in a single-predator (Wolf), two-prey (moose and caribou) system to evaluate these space-use hypotheses. The study was conducted in contrasting sections of a large boreal forest area in northern Ontario, Canada, with a spatial gradient of human disturbances and predator and prey densities. Our results indicated that wolves consistently used forest stands preferred by moose, their main prey species in this part of Ontario. Direct use of prey-rich areas was also significant but restricted to where there was a high local density of moose, whereas use of linear features was pronounced where local moose density was lower. These behaviors suggest that Wolf foraging decisions, while consistently influenced by spatially anchored patches of prey forage resources, were also determined by local ecological conditions, specifically prey density. Wolves appeared to utilize prey-rich areas when regional preferred prey density exceeded a threshold that made this profitable, whereas they disproportionately used linear features that promoted mobility when low prey density made directly tracking prey distribution unprofitable
Illness perceptions and explanatory models of viral hepatitis B & C among immigrants and refugees: a narrative systematic review.
© 2015 Owiti et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.BACKGROUND: Hepatitis B and C (HBV, HCV) infections are associated with high morbidity and mortality. Many countries with traditionally low prevalence (such as UK) are now planning interventions (screening, vaccination, and treatment) of high-risk immigrants from countries with high prevalence. This review aimed to synthesise the evidence on immigrants' knowledge of HBV and HCV that might influence the uptake of clinical interventions. The review was also used to inform the design and successful delivery of a randomised controlled trial of targeted screening and treatment. METHODS: Five databases (PubMed, CINHAL, SOCIOFILE, PsycINFO & Web of Science) were systematically searched, supplemented by reference tracking, searches of selected journals, and of relevant websites. We aimed to identify qualitative and quantitative studies that investigated knowledge of HBV and HCV among immigrants from high endemic areas to low endemic areas. Evidence, extracted according to a conceptual framework of Kleinman's explanatory model, was subjected to narrative synthesis. We adapted the PEN-3 model to categorise and analyse themes, and recommend strategies for interventions to influence help-seeking behaviour. RESULTS: We identified 51 publications including quantitative (n = 39), qualitative (n = 11), and mixed methods (n = 1) designs. Most of the quantitative studies included small samples and had heterogeneous methods and outcomes. The studies mainly concentrated on hepatitis B and ethnic groups of South East Asian immigrants residing in USA, Canada, and Australia. Many immigrants lacked adequate knowledge of aetiology, symptoms, transmission risk factors, prevention strategies, and treatment, of hepatitis HBV and HCV. Ethnicity, gender, better education, higher income, and English proficiency influenced variations in levels and forms of knowledge. CONCLUSION: Immigrants are vulnerable to HBV and HCV, and risk life-threatening complications from these infections because of poor knowledge and help-seeking behaviour. Primary studies in this area are extremely diverse and of variable quality precluding meta-analysis. Further research is needed outside North America and Australia
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