2,155 research outputs found
Support for midlife anxiety diagnosis as an independent risk factor for dementia: a systematic review
OBJECTIVES: Anxiety is an increasingly recognised predictor of cognitive deterioration in older adults and in those with mild cognitive impairment. Often believed to be a prodromal feature of neurodegenerative disease, anxiety may also be an independent risk factor for dementia, operationally defined here as preceding dementia diagnosis by ≥10 years. DESIGN: A systematic review of the literature on anxiety diagnosis and long-term risk for dementia was performed following published guidelines. SETTING AND PARTICIPANTS: Medline, PsycINFO and Embase were searched for peer-reviewed journals until 8 March 2017. Publications reporting HR/OR for all-cause dementia based on clinical criteria from prospective cohort or case-control studies were selected. Included studies measured clinically significant anxiety in isolation or after controlling for symptoms of depression, and reported a mean interval between anxiety assessment and dementia diagnosis of at least 10 years. Methodological quality assessments were performed using the Newcastle-Ottawa Scale. OUTCOME MEASURE: HR/OR for all-cause dementia. RESULTS: Searches yielded 3510 articles, of which 4 (0.02%) were eligible. The studies had a combined sample size of 29 819, and all studies found a positive association between clinically significant anxiety and future dementia. Due to the heterogeneity between studies, a meta-analysis was not conducted. CONCLUSIONS: Clinically significant anxiety in midlife was associated with an increased risk of dementia over an interval of at least 10 years. These findings indicate that anxiety may be a risk factor for late-life dementia, excluding anxiety that is related to prodromal cognitive decline. With increasing focus on identifying modifiable risk factors for dementia, more high-quality prospective studies are required to clarify whether clinical anxiety is a risk factor for dementia, separate from a prodromal symptom
PXRF analysis of a yellow ochre quarry and rock art motifs in the Central Pilbara
The significance of ochre in Indigenous Australia is well documented. Several large, well-known quarries containing ochre that is highly sought after have been described in the archaeological literature, however less attention has been paid to smaller, regionally and locally significant quarries. In this paper a small yellow ochre quarry (VSTA_20140611_1) from the Central Pilbara, where evidence of paint preparation is preserved in the form of residues in two in situ grinding hollows, is described in order to address this oversight. Portable XRF (pXRF) analysis of the pigment in the quarry itself and the paint in the hollows was undertaken to understand the chemistry of the pigmentaceous minerals, to explore the taphonomy of the ochre seam, and to gauge variation within the source. Chemistry indicates that the VSTA_20140611_1 quarry is composed of an iron mineral (likely a hydroxide such as goethite), with Fe abundances consistently between 10.7 and 30%. Typical of the regional geology, the yellow pigment is consistently siliceous, with an Si abundance of between 5.8 and 20.4%. As there are no painted motifs in the rockshelter containing the VSTA_20140611_1 quarry, nor on the suitable BIF surfaces nearby, it is considered highly likely that the surviving paint produced on-site was used for either body decoration or the adornment of artefacts, rather than for rock art production. Nevertheless, the similarity in chemical composition between the VSTA_20140611_1 pigments and that of motifs painted in sites a few kilometres away suggests that, in addition to immediate processing and use at the site, ochre from this quarry may have been transported to rockshelters in the vicinity and used for rock art production
Bioinformatic analysis of Entamoeba histolytica SINE1 elements
BACKGROUND: Invasive amoebiasis, caused by infection with the human parasite Entamoeba histolytica remains a major cause of morbidity and mortality in some less-developed countries. Genetically E. histolytica exhibits a number of unusual features including having approximately 20% of its genome comprised of repetitive elements. These include a number of families of SINEs - non-autonomous elements which can, however, move with the help of partner LINEs. In many eukaryotes SINE mobility has had a profound effect on gene expression; in this study we concentrated on one such element - EhSINE1, looking in particular for evidence of recent transposition. RESULTS: EhSINE1s were detected in the newly reassembled E. histolytica genome by searching with a Hidden Markov Model developed to encapsulate the key features of this element; 393 were detected. Examination of their sequences revealed that some had an internal structure showing one to four 26-27 nt repeats. Members of the different classes differ in a number of ways and in particular those with two internal repeats show the properties expected of fairly recently transposed SINEs - they are the most homogeneous in length and sequence, they have the longest (i.e. the least decayed) target site duplications and are the most likely to show evidence (in a cDNA library) of active transcription. Furthermore we were able to identify 15 EhSINE1s (6 pairs and one triplet) which appeared to be identical or very nearly so but inserted into different sites in the genome; these provide good evidence that if mobility has now ceased it has only done so very recently. CONCLUSIONS: Of the many families of repetitive elements present in the genome of E. histolytica we have examined in detail just one - EhSINE1. We have shown that there is evidence for waves of transposition at different points in the past and no evidence that mobility has entirely ceased. There are many aspects of the biology of this parasite which are not understood, in particular why it is pathogenic while the closely related species E. dispar is not, the great genetic diversity found amongst patient isolates and the fact, which may be related, that only a small proportion of those infected develop clinical invasive amoebiasis. Mobile genetic elements, with their ability to alter gene expression may well be important in unravelling these puzzles
Smoothing effect and delocalization of interacting Bose-Einstein condensates in random potentials
We theoretically investigate the physics of interacting Bose-Einstein
condensates at equilibrium in a weak (possibly random) potential. We develop a
perturbation approach to derive the condensate wavefunction for an amplitude of
the potential smaller than the chemical potential of the condensate and for an
arbitrary spatial variation scale of the potential. Applying this theory to
disordered potentials, we find in particular that, if the healing length is
smaller than the correlation length of the disorder, the condensate assumes a
delocalized Thomas-Fermi profile. In the opposite situation where the
correlation length is smaller than the healing length, we show that the random
potential can be significantly smoothed and, in the meanfield regime, the
condensate wavefunction can remain delocalized, even for very small correlation
lengths of the disorder.Comment: The word "screening" has been changed to "smoothing" to avoid
confusions with other effects discussed in the literature. This does not
affect the content of paper, nor the results, nor the physical discussio
A Study of Degenerate Four-quark states in SU(2) Lattice Monte Carlo
The energies of four-quark states are calculated for geometries in which the
quarks are situated on the corners of a series of tetrahedra and also for
geometries that correspond to gradually distorting these tetrahedra into a
plane. The interest in tetrahedra arises because they are composed of {\bf
three } degenerate partitions of the four quarks into two two-quark colour
singlets. This is an extension of earlier work showing that geometries with
{\bf two} degenerate partitions (e.g.\ squares) experience a large binding
energy. It is now found that even larger binding energies do not result, but
that for the tetrahedra the ground and first excited states become degenerate
in energy. The calculation is carried out using SU(2) for static quarks in the
quenched approximation with on a lattice. The
results are analysed using the correlation matrix between different euclidean
times and the implications of these results are discussed for a model based on
two-quark potentials.Comment: Original Raw PS file replace by a tarred, compressed and uuencoded PS
fil
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Submesoscale Kinematic Properties in Summer and Winter Surface Flows in the Northern Gulf of Mexico
Statistical properties of near-surface horizontal velocity gradients are obtained from four drifter experiments conducted in the Gulf of Mexico during Summer 2012 and Winter 2016. The data density provided by the near-simultaneous deployments of 90-326 surface drifters in each allows direct, drifter-based estimates of the scale dependence of velocity gradients at separation scales ranging from 200 m to 5 km. The robustness of these estimates, derived from uniquley sampled, nearly equilateral triplets, is confirmed by comparisons with estimates produced from larger drifter clusters, and with estimates based on concurrent Eulerian X-band radar observations. The winter launches were deployed above a ∼80 m deep mixed layer, one in a region with nearly homogeneous horizontal density structure, the other in a region of strong surface density gradients associated with filaments of fresh Mississippi River water. The summer launches occurred in a shallow (10m) mixed layer, one launched across a mesoscale frontal jet separating regions of horizontally homogeneous density and the other, similar to the corresponding winter launch, also in a region filamented by shallow lenses of cold, fresh water. Seasonal differences are observed, with larger velocity fluctuations and greater variance in divergence and vorticity, especially at the smallest scales, in winter. Differences between same-season launches are, however, as large as seasonal differences. In both seasons, observations sampling regions directly impacted by fresh water fluxes show strongly skewed vorticity distributions, with cyclonic vorticity dominating strain. For the other launches, one in each season, strain dominated minimally skewed vorticity
Orbitally excited and hybrid mesons from the lattice
We discuss in general the construction of gauge-invariant non-local meson
operators on the lattice. We use such operators to study the - and -wave
mesons as well as hybrid mesons in quenched QCD, with quark masses near the
strange quark mass. The resulting spectra are compared with experiment for the
orbital excitations. For the states produced by gluonic excitations (hybrid
mesons) we find evidence of mixing for non-exotic quantum numbers. We give
predictions for masses of the spin-exotic hybrid mesons with $J^{PC}=1^{-+},\
0^{+-}2^{+-}$.Comment: 31 pages, LATEX, 8 postscript figures. Reference adde
Hadronic Annihilation Decay Rates of P-wave Heavy Quarkonia with Both Relativistic and QCD Radiative Corrections
Hadronic annihilation decay rates of P-wave heavy quarkonia are given to
next-to-leading order in both and . They include ten
nonperturbative parameters, which can be rigorously defined as the matrix
elements of color-singlet and color-octet operators in NRQCD. We expect these
papameters will be determined from lattice calculations in future.Comment: 5 Pages RevTex. The paper is withdraw
How data visualisation using historical medical journals can contribute to current debates around antibiotic use and antimicrobial resistance in primary care
BackgroundThe early years of antibiotic use in primary care (c1950-1969) has received little attention. Medical journals provide a rich source for studying historic healthcare practitioners’ views and interests, with the potential to inform contemporary debate around issues of overuse and antimicrobial resistance. AimsPilot study to test the application of digital methods to interrogate historical medical journal data in relation to antibiotic use.Methods / ApproachMeta-data and scanned articles were extracted from the online British Journal of General Practice (BJGP) archive from inception (1953) to 1969. Searchable text was generated using an application called ABBYY optical character recognition, and Python used to generate data visualisations exploring (1) how BJGP changed during the period, (2) mentions of terms ‘antibiotic(s)’, ‘penicillin’, ‘resistance/resistant’ and mapping when and where they occurred.Results / EvaluationFrom 1953-1969, BJGP expanded in terms of number of annual issues (4 to 17) and annual pages (<25 to >1100). Heatmap visualisations were used to facilitate understanding of the frequency with which use of the term ‘antibiotic(s)’ occurred. By 1969 an article mentioning ‘antibiotic(s)’ was published monthly. Bigram searches found ‘treatment’ and ‘therapy’ to be the two most common terms that appeared with ‘antibiotic(s)’. The fourth and seventh most common terms were ‘resistant’ (first appearing in 1955) and ‘resistance’ (1962).ConclusionsThis pilot work shows that primary care publications increased considerably between 1953-1969. Articles on antibiotics featured frequently in relation to therapeutic intervention, and concerns around resistance occurred at an early stage. This approach provides new insights into how attitudes and behaviours around antibiotic use by primary care have evolved over time. It may also have the potential to inform study of the future use of antibiotics in primary care. <br/
Supportive care for men with prostate cancer:why are the trials not working? A systematic review and recommendations for future trials
Men with prostate cancer are likely to have a long illness and experience psychological distress for which supportive care may be helpful. This systematic review describes the evidence for effectiveness and cost-effectiveness of supportive care for men with prostate cancer, taking into account treatment pathway and components of interventions. MEDLINE, EMBASE, CINAHL, CENTRAL, and Psychinfo were searched from inception––July 2013 for randomized controlled trials and controlled trials. Two authors independently assessed risk of bias and extracted data. Twenty-six studies were included (2740 participants). Interventions were delivered pre and during (n = 12), short-term (n = 8), and longer term (18 months) (n = 5) after primary treatment. No interventions were delivered beyond this time. Few trials recruited ethnic minorities and none recruited men in same sex relationships. Intervention components included information, education, health professional discussion, homework, peer discussion, buddy support, cognitive behavioral therapy, cognitive restructuring, psychoeducation, Reiki and relaxation. Most interventions were delivered for 5–10 weeks. Risk of bias of trials was assessed as unclear for most domains due to lack of information. The majority of trials measuring quality of life and depression found no effect. Relatively few trials measured anxiety, coping skills and self-efficacy, and the majority found no effect. No cost data were available. Trials of supportive care for men with prostate cancer cover a range of interventions but are limited by population diversity, inconsistent measurement and reporting of outcomes, and inability to assess risk of bias. Recommendations on design and conduct of future trials are presented
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