2,123 research outputs found
The prevalence and experience of oral diseases in Adelaide nursing home residents
The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: The twenty-first century will see the evolution of a population of dentate older Australians with dental needs very different from those of older adults in past years. This study provided comprehensive information concerning oral disease prevalence in older South Australian nursing home residents. Methods: This paper presents cross-sectional baseline results. Results: Most of the 224 residents, from seven randomly selected nursing homes, were functionally dependent, medically compromised, cognitively impaired and behaviourally difficult older adults who presented many complex challenges to carers and to dental professionals. Two-thirds (66 per cent) were edentulous with many dental problems and treatment needs. Dentate residents had a mean of 11.9 teeth present, higher than previously reported. The prevalence and experience of coronal and root caries and plaque accumulation was very high in dentate residents; especially males, those admitted more than three years previously, those who ate fewer food types and those who were severely cognitively impaired. These residents had more retained roots, decayed teeth and missing teeth, and fewer filled teeth when compared with data for community-dwelling older adults. Conclusions: This study highlighted the poor oral health status of these nursing home residents and the great impact of dementia on their high levels of oral diseases.JM Chalmers, C Hodge, JM Fuss, AJ Spencer, KD Carte
Psychosocial functioning and intelligence both partly explain socioeconomic inequalities in premature death. A population-based male cohort study
The possible contributions of psychosocial functioning and intelligence differences to socioeconomic status (SES)-related inequalities in premature death were investigated. None of the previous studies focusing on inequalities in mortality has included measures of both psychosocial functioning and intelligence.The study was based on a cohort of 49 321 men born 1949-1951 from the general community in Sweden. Data on psychosocial functioning and intelligence from military conscription at ∼18 years of age were linked with register data on education, occupational class, and income at 35-39 years of age. Psychosocial functioning was rated by psychologists as a summary measure of differences in level of activity, power of initiative, independence, and emotional stability. Intelligence was measured through a multidimensional test. Causes of death between 40 and 57 years of age were followed in registers.The estimated inequalities in all-cause mortality by education and occupational class were attenuated with 32% (95% confidence interval: 20-45%) and 41% (29-52%) after adjustments for individual psychological differences; both psychosocial functioning and intelligence contributed to account for the inequalities. The inequalities in cardiovascular and injury mortality were attenuated by as much as 51% (24-76%) and 52% (35-68%) after the same adjustments, and the inequalities in alcohol-related mortality were attenuated by up to 33% (8-59%). Less of the inequalities were accounted for when those were measured by level of income, with which intelligence had a weaker correlation. The small SES-related inequalities in cancer mortality were not attenuated by adjustment for intelligence.Differences in psychosocial functioning and intelligence might both contribute to the explanation of observed SES-related inequalities in premature death, but the magnitude of their contributions likely varies with measure of socioeconomic status and cause of death. Both psychosocial functioning and intelligence should be considered in future studies
Visual ecology of aphids – a critical review on the role of colours in host finding
We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms.
Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region.
We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours
that are not likely to hold. Finally we also discuss the
implications for developing and optimising strategies
of aphid control and monitoring
Non-thermal emission processes in massive binaries
In this paper, I present a general discussion of several astrophysical
processes likely to play a role in the production of non-thermal emission in
massive stars, with emphasis on massive binaries. Even though the discussion
will start in the radio domain where the non-thermal emission was first
detected, the census of physical processes involved in the non-thermal emission
from massive stars shows that many spectral domains are concerned, from the
radio to the very high energies.
First, the theoretical aspects of the non-thermal emission from early-type
stars will be addressed. The main topics that will be discussed are
respectively the physics of individual stellar winds and their interaction in
binary systems, the acceleration of relativistic electrons, the magnetic field
of massive stars, and finally the non-thermal emission processes relevant to
the case of massive stars. Second, this general qualitative discussion will be
followed by a more quantitative one, devoted to the most probable scenario
where non-thermal radio emitters are massive binaries. I will show how several
stellar, wind and orbital parameters can be combined in order to make some
semi-quantitative predictions on the high-energy counterpart to the non-thermal
emission detected in the radio domain.
These theoretical considerations will be followed by a census of results
obtained so far, and related to this topic... (see paper for full abstract)Comment: 47 pages, 5 postscript figures, accepted for publication in Astronomy
and Astrophysics Review. Astronomy and Astrophysics Review, in pres
Development of a polymer endovascular prosthesis and its implantation in porcine arteries
A polyethylene-terephthalate braided mesh stent has been developed for application in the (coronary) arterial tree. In vitro measurements showed that the radial pressure delivered by this device was in the same range as that of a stainless steel stent. Hysteresis-like behavior, however, occurred after constraining the polyester stent for a period of only 15 minutes on a delivery system for percutaneous implantation. This implies that the polymer stent must be mounted on this delivery system immediately before the placement procedure, and that either a diameter in the unconstrained condition must be selected, which is considerably larger than the diameter of the target vessel, or stent expansion has to be enhanced by balloon expansion. Taking into account the results obtained during the in vitro studies, we investigated the angiographic patency and histologic features after implantation of this polyester stent in peripheral arteries of pigs. In four animals eight stents were placed. Except for heparin during the implantation procedure only, antithrombotic or antiplatelet drugs were not administered. After 4 weeks repeat angiography was performed. Angiography revealed that five of the six correctly placed stents were patent. At autopsy, two additional patent stents proved to be located in the aortic bifurcation, probably due to failure of the delivery system. Quantitative assessment showed that the mean luminal diameters of the site of stent placement were 3.3 +/- 0.2 mm before, 3.2 +/- 0.2 mm immediately after, and 3.1 +/- 0.3 mm at 4 weeks after implantation. Histology demonstrated an inflammatory reaction of variable severity around the stent fibers. Quantitative histologic measurements showed that the thickness of the neointima was 114 +/- 38 mum after 4 weeks. In conclusion, polyester stents can be constructed with mechanical properties similar to stainless steel stents. Hysteresis-like behavior of polyester stents, however, influences the selection of the nominal stent diameter as well as the forces exerted to the vessel wall. After implantation in porcine peripheral arteries, five of six correctly placed stents were patent at 4 weeks. The extent of neointimal proliferation was similar to that observed after placement of metal stents in swine, despite the presence of a more pronounced inflammatory reaction
Defending the genome from the enemy within:mechanisms of retrotransposon suppression in the mouse germline
The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
Small RNA populations revealed by blocking rRNA fragments in Drosophila melanogaster reproductive tissues
RNA interference (RNAi) is a complex and highly conserved regulatory mechanism mediated via small RNAs (sRNAs). Recent technical advances in high throughput sequencing have enabled an increasingly detailed analysis of sRNA abundances and profiles in specific body parts and tissues. This enables investigations of the localized roles of microRNAs (miRNAs) and small interfering RNAs (siRNAs). However, variation in the proportions of non-coding RNAs in the samples being compared can hinder these analyses. Specific tissues may vary significantly in the proportions of fragments of longer non-coding RNAs (such as ribosomal RNA or transfer RNA) present, potentially reflecting tissue-specific differences in biological functions. For example, in Drosophila, some tissues contain a highly abundant 30nt rRNA fragment (the 2S rRNA) as well as abundant 5’ and 3’ terminal rRNA fragments. These can pose difficulties for the construction of sRNA libraries as they can swamp the sequencing space and obscure sRNA abundances. Here we addressed this problem and present a modified “rRNA blocking” protocol for the construction of high-definition (HD) adapter sRNA libraries, in D. melanogaster reproductive tissues. The results showed that 2S rRNAs targeted by blocking oligos were reduced from >80% to < 0.01% total reads. In addition, the use of multiple rRNA blocking oligos to bind the most abundant rRNA fragments allowed us to reveal the underlying sRNA populations at increased resolution. Side-by-side comparisons of sequencing libraries of blocked and non-blocked samples revealed that rRNA blocking did not change the miRNA populations present, but instead enhanced their abundances. We suggest that this rRNA blocking procedure offers the potential to improve the in-depth analysis of differentially expressed sRNAs within and across different tissues
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