524 research outputs found
Practitioners’ understanding of barriers to accessing specialist support by family carers of people with dementia in distress
Distressing symptoms in dementia are hard to manage for many family carers. This article explores practitioners' perceptions of the barriers to accessing skilled behaviour management support encountered by carers. A survey of cases referred to the English National Health Service (n = 5,360) was followed by in-depth group discussions and practitioner interviews. Data revealed that practitioners focused on care home residents or older people with mental health problems other than dementia, rather than community-dwelling people with dementia and families. Barriers to access included misperceptions about the nature of distressing behaviour affecting carers and structural limitations in the capacity of specialist services to respond to carers
Synthesis of atropisomeric phosphino-triazoles and their corresponding gold(i) complexes
The synthesis of atropisomeric phoshino-triazoles is disclosed. It was found that the introduction of a phosphine functionality onto the 5-position of a 1,2,3-triazole ring could be highly restrictive towards the rotation around a triazole-aryl bond. VT NMR and chiral HPLC studies demonstrated that rotation was restricted even at high temperatures. Gold(I) chloride complexes of single-enantiomer phosphines were prepared and again demonstrated to be conformationally stable
Water in HD 209458b's atmosphere from 3.6 - 8 microns IRAC photometric observations in primary transit
The hot Jupiter HD 209458b was observed during primary transit at 3.6, 4.5,
5.8 and 8.0 microns using the Infrared Array Camera (IRAC) on the Spitzer Space
Telescope. We detail here the procedures we adopted to correct for the
systematic trends present in the IRAC data. The light curves were fitted
including limb darkening effects and fitted using Markov Chain Monte Carlo and
prayer-bead Monte Carlo techniques, finding almost identical results. The final
depth measurements obtained by a combined Markov Chain Monte Carlo fit are at
3.6 microns, 1.469 +- 0.013 % and 1.448 +- 0.013 %; at 4.5 microns, 1.478 +-
0.017 % ; at 5.8 microns, 1.549 +- 0.015 % and at 8.0 microns 1.535 +- 0.011 %.
Our results clearly indicate the presence of water in the planetary atmosphere.
Our broad band photometric measurements with IRAC prevent us from determining
the additional presence of other other molecules such as CO, CO2 and methane
for which spectroscopy is needed. While water vapour with a mixing ratio of
10^-4-10^-3 combined with thermal profiles retrieved from the day-side may
provide a very good fit to our observations, this data set alone is unable to
resolve completely the degeneracy between water abundance and atmospheric
thermal profile.Comment: 14 pages, 6 tables, 10 figures, Accepted for publication in MNRA
An ingress and a complete transit of HD 80606 b
We have used four telescopes at different longitudes to obtain
near-continuous lightcurve coverage of the star HD 80606 as it was transited by
its \sim 4-MJup planet. The observations were performed during the predicted
transit windows around the 25th of October 2008 and the 14th of February 2009.
Our data set is unique in that it simultaneously constrains the duration of the
transit and the planet's period. Our Markov-Chain Monte Carlo analysis of the
light curves, combined with constraints from radial-velocity data, yields
system parameters consistent with previously reported values. We find a
planet-to-star radius ratio marginally smaller than previously reported,
corresponding to a planet radius of Rp = 0.921 \pm 0.036RJup .Comment: 6 pages, 2 figures, MNRAS accepte
Line-profile tomography of exoplanet transits -- II. A gas-giant planet transiting a rapidly-rotating A5 star
Most of our knowledge of extrasolar planets rests on precise radial-velocity
measurements, either for direct detection or for confirmation of the planetary
origin of photometric transit signals. This has limited our exploration of the
parameter space of exoplanet hosts to solar- and later-type, sharp-lined stars.
Here we extend the realm of stars with known planetary companions to include
hot, fast-rotating stars. Planet-like transits have previously been reported in
the lightcurve obtained by the SuperWASP survey of the A5 star HD15082
(WASP-33; V=8.3, v sin i = 86 km/sec). Here we report further photometry and
time-series spectroscopy through three separate transits, which we use to
confirm the existence of a gas giant planet with an orbital period of 1.22d in
orbit around HD15082. From the photometry and the properties of the planet
signal travelling through the spectral line profiles during the transit we
directly derive the size of the planet, the inclination and obliquity of its
orbital plane, and its retrograde orbital motion relative to the spin of the
star. This kind of analysis opens the way to studying the formation of planets
around a whole new class of young, early-type stars, hence under different
physical conditions and generally in an earlier stage of formation than in
sharp-lined late-type stars. The reflex orbital motion of the star caused by
the transiting planet is small, yielding an upper mass limit of 4.1 Jupiter
masses on the planet. We also find evidence of a third body of sub-stellar mass
in the system, which may explain the unusual orbit of the transiting planet. In
HD 15082, the stellar line profiles also show evidence of non-radial
pulsations, clearly distinct from the planetary transit signal. This raises the
intriguing possibility that tides raised by the close-in planet may excite or
amplify the pulsations in such stars.Comment: 9 pages, 6 figures, accepted for publication in MNRA
Effects of mountain gorilla foraging activities on the productivity of their food plant species
Mountain gorillas subsist principally on foliage from the dense herbaceous understorey that is found throughout most of their habitat in the Virunga Volcanoes region. Their foraging activities cause considerable structural damage to this vegetation. Those plant species that are quantitatively most important in the gorillas' diet respond to this damage by increasing primary productivity. At a sample of spots at which gorillas had fed, these species showed significantly higher growth rates over a 6-month interval than they did at nearby spots that had not been touched by the gorillas. Stem densities of herbaceous food species at feeding spots increased markedly both in comparison to their original values and to values for the same species at untouched spots. As a result, spots at which gorillas have fed are likely to become very attractive as future feeding spots. It is unlikely that gorillas ‘manage’ their habitat in any specific fashion, largely because they do not have exclusive use of their home ranges. Their activities appear to maintain habitat productivity over the short term, on a time scale relevant to patterns of area revisits by social groups, and may contribute to long term beneficial alterations of regularly used areas, however. Effects of the type reported here may have been an important aspect of the adaptation by gorillas to terrestrial folivory. RÉSUMEÉ Les gorilles de montagne s'alimentent principalement de feuillages dans le sous-bois herbacÉ dense prÉsent presque partout dans leur habitat de la rÉgion des volcans Virunga. Leurs activitÉs alimentaires causent des dommages structurels considÉrables À cette vÉgÉtation. Les plantes des espÈces qui sont quantitativement les plus importants dans le rÉgime du gorille rÉagissent À ces dÉgats en augmentant leur productivitÉ primaire. Aux postes Échantillons oÙ les gorilles se sont nourris, ces espÈces prÉsentent des taux de croissance significantivement supÉrieurs sur un intervalle de six mois, par rapport aux postes voisins qui n'ont pas ÉtÉ touchÉs par les gorilles. Les densitÉs de tiges des espÈces herbacÉes appÉtÉes aux postes de nourrissage augmentent nettement aussi bien en comparaison avec leurs valeurs antÉrieures qu'avec celles de ces měmes espÈces dans des stations non touchÉes. En consÉquence, les postes oÙ les gorilles se sont nourris ont plus de chance de devenir des futurs postes de nourrissage trÈs attractifs. Il est peu probable que les gorilles ‘gÈrent’ leur habitat d'une quelconque faÇon, surtout parce qu'ils n'ont pas l'utilisation exclusive de leur domaine vital. Leurs activitÉs semblent maintenir À court terme la productivitÉ de leur habitat, sur une Échelle de temps comprenant les visites successives de groupes sociaux, et peuvent contribuer À long terme À des altÉrations bÉnÉfiques pour ces zones rÉguliÉrement frÉquentÉes. Des effets du type rapportÉ ici peuvent avoir ÉtÉ un ÉlÉment important de l'adaptation des gorilles À la folivorie terrestre.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75171/1/j.1365-2028.1987.tb01102.x.pd
Methane in the atmosphere of the transiting hot Neptune GJ436b?
We present an analysis of seven primary transit observations of the hot
Neptune GJ436b at 3.6, 4.5 and m obtained with the Infrared Array Camera
(IRAC) on the Spitzer Space Telescope. After correcting for systematic effects,
we fitted the light curves using the Markov Chain Monte Carlo technique.
Combining these new data with the EPOXI, HST and ground-based and
published observations, the range m can be covered. Due to
the low level of activity of GJ436, the effect of starspots on the combination
of transits at different epochs is negligible at the accuracy of the dataset.
Representative climate models were calculated by using a three-dimensional,
pseudo-spectral general circulation model with idealised thermal forcing.
Simulated transit spectra of GJ436b were generated using line-by-line radiative
transfer models including the opacities of the molecular species expected to be
present in such a planetary atmosphere. A new, ab-initio calculated, linelist
for hot ammonia has been used for the first time. The photometric data observed
at multiple wavelengths can be interpreted with methane being the dominant
absorption after molecular hydrogen, possibly with minor contributions from
ammonia, water and other molecules. No clear evidence of carbon monoxide and
dioxide is found from transit photometry. We discuss this result in the light
of a recent paper where photochemical disequilibrium is hypothesised to
interpret secondary transit photometric data. We show that the emission
photometric data are not incompatible with the presence of abundant methane,
but further spectroscopic data are desirable to confirm this scenario.Comment: 19 pages, 10 figures, 1 table, Astrophysical Journal in pres
A cell cycle-coordinated Polymerase II transcription compartment encompasses gene expression before global genome activation
© 2019, The Author(s). Most metazoan embryos commence development with rapid, transcriptionally silent cell divisions, with genome activation delayed until the mid-blastula transition (MBT). However, a set of genes escapes global repression and gets activated before MBT. Here we describe the formation and the spatio-temporal dynamics of a pair of distinct transcription compartments, which encompasses the earliest gene expression in zebrafish. 4D imaging of pri-miR430 and zinc-finger-gene activities by a novel, native transcription imaging approach reveals transcriptional sharing of nuclear compartments, which are regulated by homologous chromosome organisation. These compartments carry the majority of nascent-RNAs and active Polymerase II, are chromatin-depleted and represent the main sites of detectable transcription before MBT. Transcription occurs during the S-phase of increasingly permissive cleavage cycles. It is proposed, that the transcription compartment is part of the regulatory architecture of embryonic nuclei and offers a transcriptionally competent environment to facilitate early escape from repression before global genome activation
Targeting the Ataxia Telangiectasia Mutated-null Phenotype in Chronic Lymphocytic Leukemia with Pro-oxidants
Inactivation of the Ataxia Telangiectasia Mutated gene in chronic lymphocytic leukemia results in resistance to p53-dependent apoptosis and inferior responses to treatment with DNA damaging agents. Hence, p53-independent strategies are required to target Ataxia
Telangiectasia Mutated-deficient chronic lymphocytic leukemia. As Ataxia Telangiectasia Mutated has been implicated in redox homeostasis, we investigated the effect of the Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia genotype on cellular responses to
oxidative stress with a view to therapeutic targeting. We found that in comparison to Ataxia Telangiectasia Mutated-wild type chronic lymphocytic leukemia, pro-oxidant treatment of Ataxia Telangiectasia Mutated-null cells led to reduced binding of NF-E2 p45-related factor-2 to antioxidant response elements and thus decreased expression of target genes. Furthermore, Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia cells contained lower levels of antioxidants and elevated mitochondrial reactive oxygen species. Consequently, Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia, but not tumours with 11q deletion or TP53 mutations, exhibited differentially increased sensitivity to pro-oxidants both in vitro and in vivo. We found that cell death was mediated by a p53- and caspase-independent mechanism associated with apoptosis inducing factor activity. Together, these data suggest that defective redox-homeostasis represents an attractive therapeutic target for Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia
Genetic analysis of the GLUT10 glucose transporter (SLC2A10) polymorphisms in Caucasian American type 2 diabetes
BACKGROUND: GLUT10 (gene symbol SLC2A10) is a facilitative glucose transporter within the type 2 diabetes (T2DM)-linked region on chromosome 20q12-13.1. Therefore, we evaluated GLUT10 as a positional candidate gene for T2DM in Caucasian Americans. METHODS: Twenty SNPs including 4 coding, 10 intronic and 6 5' and 3' to the coding sequence were genotyped across a 100 kb region containing the SLC2A10 gene in DNAs from 300 T2DM cases and 310 controls using the Sequenom MassArray Genotyping System. Allelic association was evaluated, and linkage disequilibrium (LD) and haplotype structure of SLC2A10 were also determined to assess whether any specific haplotypes were associated with T2DM. RESULTS: Of these variants, fifteen had heterozygosities greater than 0.80 and were analyzed further for association with T2DM. No evidence of significant association was observed for any variant with T2DM (all P ≥ 0.05), including Ala206Thr (rs2235491) which was previously reported to be associated with fasting insulin. Linkage disequilibrium analysis suggests that the SLC2A10 gene is contained in a single haplotype block of 14 kb. Haplotype association analysis with T2DM did not reveal any significant differences between haplotype frequencies in T2DM cases and controls. CONCLUSION: From our findings, we can conclude that sequence variants in or near GLUT10 are unlikely to contribute significantly to T2DM in Caucasian Americans
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