160 research outputs found

    Cosmology of the selfaccelerating third order Galileon

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    In this paper we start from the original formulation of the galileon model with the original choice for couplings to gravity. Within this framework we find that there is still a subset of possible Lagrangians that give selfaccelerating solutions with stable spherically symmetric solutions. This is a certain constrained subset of the third order galileon which has not been explored before. We develop and explore the background cosmological evolution of this model drawing intuition from other even more restricted galileon models. The numerical results confirm the presence of selfacceleration, but also reveals a possible instability with respect to galileon perturbations.Comment: 30 pages, 24 figure

    A Three-Way Comparison of Tuberculin Skin Testing, QuantiFERON-TB Gold and T-SPOT.TB in Children

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    BACKGROUND: There are limited data comparing the performance of the two commercially available interferon gamma (IFN-gamma) release assays (IGRAs) for the diagnosis of tuberculosis (TB) in children. We compared QuantiFERON-TB gold In Tube (QFT-IT), T-SPOT.TB and the tuberculin skin test (TST) in children at risk for latent TB infection or TB disease. METHODS AND FINDINGS: The results of both IGRAs were compared with diagnosis assigned by TST-based criteria and assessed in relation to TB contact history. Results from the TST and at least one assay were available for 96 of 100 children. Agreement between QFT-IT and T-SPOT.TB was high (93% agreement, kappa = 0.83). QFT-IT and T-SPOT.TB tests were positive in 8 (89%) and 9 (100%) children with suspected active TB disease. There was moderate agreement between TST and either QFT-IT (75%, kappa = 0.50) or T-SPOT.TB (75%, kappa = 0.51). Among 38 children with TST-defined latent TB infection, QFT-IT gold and T-SPOT.TB assays were positive in 47% and 39% respectively. Three TST-negative children were positive by at least one IGRA. Children with a TB contact were more likely than children without a TB contact to have a positive IGRA (QFT-IT LR 3.9; T-SPOT.TB LR 3.9) and a positive TST (LR 1.4). Multivariate linear regression analysis showed that the magnitude of both TST induration and IGRA IFN-gamma responses was significantly influenced by TB contact history, but only the TST was influenced by age. CONCLUSIONS: Although a high level of agreement between the IGRAs was observed, they are commonly discordant with the TST. The correct interpretation of a negative assay in a child with a positive skin test in clinical practice remains challenging and highlights the need for longitudinal studies to determine the negative predictive value of IGRAs

    Cold gas accretion in galaxies

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    Evidence for the accretion of cold gas in galaxies has been rapidly accumulating in the past years. HI observations of galaxies and their environment have brought to light new facts and phenomena which are evidence of ongoing or recent accretion: 1) A large number of galaxies are accompanied by gas-rich dwarfs or are surrounded by HI cloud complexes, tails and filaments. It may be regarded as direct evidence of cold gas accretion in the local universe. It is probably the same kind of phenomenon of material infall as the stellar streams observed in the halos of our galaxy and M31. 2) Considerable amounts of extra-planar HI have been found in nearby spiral galaxies. While a large fraction of this gas is produced by galactic fountains, it is likely that a part of it is of extragalactic origin. 3) Spirals are known to have extended and warped outer layers of HI. It is not clear how these have formed, and how and for how long the warps can be sustained. Gas infall has been proposed as the origin. 4) The majority of galactic disks are lopsided in their morphology as well as in their kinematics. Also here recent accretion has been advocated as a possible cause. In our view, accretion takes place both through the arrival and merging of gas-rich satellites and through gas infall from the intergalactic medium (IGM). The infall may have observable effects on the disk such as bursts of star formation and lopsidedness. We infer a mean ``visible'' accretion rate of cold gas in galaxies of at least 0.2 Msol/yr. In order to reach the accretion rates needed to sustain the observed star formation (~1 Msol/yr), additional infall of large amounts of gas from the IGM seems to be required.Comment: To appear in Astronomy & Astrophysics Reviews. 34 pages. Full-resolution version available at http://www.astron.nl/~oosterlo/accretionRevie

    The PRO-RCC study:a long-term PROspective Renal Cell Carcinoma cohort in the Netherlands, providing an infrastructure for ‘Trial within Cohorts’ study designs

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    BACKGROUND: Ongoing research in the field of both localized, locally advanced and metastatic renal cell carcinoma has resulted in the availability of multiple treatment options. Hence, many questions are still unanswered and await further research. A nationwide collaborative registry allows to collect corresponding data. For this purpose, the Dutch PROspective Renal Cell Carcinoma cohort (PRO-RCC) has been founded, for the prospective collection of long-term clinical data, patient reported outcome measures (PROMs) and patient reported experience measures (PREMs).METHODS: PRO-RCC is designed as a multicenter cohort for all Dutch patients with renal cell carcinoma (RCC). Recruitment will start in the Netherlands in 2023. Importantly, participants may also consent to participation in a 'Trial within cohorts' studies (TwiCs). The TwiCs design provides a method to perform (randomized) interventional studies within the registry. The clinical data collection is embedded in the Netherlands Cancer Registry (NCR). Next to the standardly available data on RCC, additional clinical data will be collected. PROMS entail Health-Related Quality of Life (HRQoL), symptom monitoring with optional ecological momentary assessment (EMA) of pain and fatigue, and optional return to work- and/or nutrition questionnaires. PREMS entail satisfaction with care. Both PROMS and PREMS are collected through the PROFILES registry and are accessible for the patient and the treating physician.TRIAL REGISTRATION: Ethical board approval has been obtained (2021_218) and the study has been registered at ClinicalTrials.gov (NCT05326620).DISCUSSION: PRO-RCC is a nationwide long-term cohort for the collection of real-world clinical data, PROMS and PREMS. By facilitating an infrastructure for the collection of prospective data on RCC, PRO-RCC will contribute to observational research in a real-world study population and prove effectiveness in daily clinical practice. The infrastructure of this cohort also enables that interventional studies can be conducted with the TwiCs design, without the disadvantages of classic RCTs such as slow patient accrual and risk of dropping out after randomization.</p

    Healthcare expenditure on Indigenous and non-Indigenous Australians at high risk of cardiovascular disease

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    Background: In spite of bearing a heavier burden of death, disease and disability, there is mixed evidence as to whether Indigenous Australians utilise more or less healthcare services than other Australians given their elevated risk level. This study analyses the Medicare expenditure and its predictors in a cohort of Indigenous and non-Indigenous Australians at high risk of cardiovascular disease. Methods: The healthcare expenditure of participants of the Kanyini Guidelines Adherence with the Polypill (GAP) pragmatic randomised controlled trial was modelled using linear regression methods. 535 adult (48% Indigenous) participants at high risk of cardiovascular disease (CVD) were recruited through 33 primary healthcare services (including 12 Aboriginal Medical Services) across Australia. Results: There was no significant difference in the expenditure of Indigenous and non-Indigenous participants in non-remote areas following adjustment for individual characteristics. Indigenous individuals living in remote areas had lower MBS expenditure (932peryearP<0.001)thanotherindividuals.MBSexpenditurewasfoundtoincreasewithbeingagedover65years(932 per year P< 0.001) than other individuals. MBS expenditure was found to increase with being aged over 65 years (128, p=0.013), being female (472,p=0.003),lowerbaselinereportedqualityoflife(472, p=0.003), lower baseline reported quality of life (102 per 0.1 decrement of utility p=0.004) and a history of diabetes (324,p=0.001),gout(324, p=0.001), gout (631, p=0.022), chronic obstructive pulmonary disease (469,p=0.019)andestablishedCVDwhetherreceivingguideline−recommendedtreatmentpriortothetrial(469, p=0.019) and established CVD whether receiving guideline-recommended treatment prior to the trial (452, p=0.005) or not (483,p=0.04).Whencontrollingforallothercharacteristics,morbidlyobesepatientshadlowerMBSexpenditurethanotherindividuals(−483, p=0.04). When controlling for all other characteristics, morbidly obese patients had lower MBS expenditure than other individuals (-887, p=0.002). Conclusion: The findings suggest that for the majority of participants, once individuals are engaged with a primary care provider, factors other than whether they are Indigenous determine the level of Medicare expenditure for each person. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN 126080005833347

    Carbon sources of Antarctic nematodes as revealed by natural carbon isotope ratios and a pulse-chase experiment

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    δ13C of nematode communities in 27 sites was analyzed, spanning a large depth range (from 130 to 2,021 m) in five Antarctic regions, and compared to isotopic signatures of sediment organic matter. Sediment organic matter δ13C ranged from −24.4 to −21.9‰ without significant differences between regions, substrate types or depths. Nematode δ13C showed a larger range, from −34.6 to −19.3‰, and was more depleted than sediment organic matter typically by 1‰ and by up to 3‰ in silty substrata. These, and the isotopically heavy meiofauna at some stations, suggest substantial selectivity of some meiofauna for specific components of the sedimenting plankton. However, 13C-depletion in lipids and a potential contribution of chemoautotrophic carbon in the diet of the abundant genus Sabatieria may confound this interpretation. Carbon sources for Antarctic nematodes were also explored by means of an experiment in which the fate of a fresh pulse of labile carbon to the benthos was followed. This organic carbon was remineralized at a rate (11–20 mg C m−2 day−1) comparable to mineralization rates in continental slope sediments. There was no lag between sedimentation and mineralization; uptake by nematodes, however, did show such a lag. Nematodes contributed negligibly to benthic carbon mineralization

    Fear of hypoglycaemia: defining a minimum clinically important difference in patients with type 2 diabetes

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    <p>Abstract</p> <p>Background</p> <p>To explore the concept of the Minimum Clinically Important Difference (MID) of the Worry Scale of the Hypoglycaemia Fear Survey (HFS-II) and to quantify the clinical importance of different types of patient-reported hypoglycaemia.</p> <p>Methods</p> <p>An observational study was conducted in Germany with 392 patients with type 2 diabetes mellitus treated with combinations of oral anti-hyperglycaemic agents. Patients completed the HFS-II, the Treatment Satisfaction Questionnaire for Medication (TSQM), and reported on severity of hypoglycaemia. Distribution- and anchor-based methods were used to determine MID. In turn, MID was used to determine if hypoglycaemia with or without need for assistance was clinically meaningful compared to having had no hypoglycaemia.</p> <p>Results</p> <p>112 patients (28.6%) reported hypoglycaemic episodes, with 15 patients (3.8%) reporting episodes that required assistance from others. Distribution- and anchor-based methods resulted in MID between 2.0 and 5.8 and 3.6 and 3.9 for the HFS-II, respectively. Patients who reported hypoglycaemia with (21.6) and without (12.1) need for assistance scored higher on the HFS-II (range 0 to 72) than patients who did not report hypoglycaemia (6.0).</p> <p>Conclusion</p> <p>We provide MID for HFS-II. Our findings indicate that the differences between having reported no hypoglycaemia, hypoglycaemia without need for assistance, and hypoglycaemia with need for assistance appear to be clinically important in patients with type 2 diabetes mellitus treated with oral anti-hyperglycaemic agents.</p

    The effectiveness of pulsed electrical stimulation (E-PES) in the management of osteoarthritis of the knee: a protocol for a randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Osteoarthritis (OA) of the knee is one of the main causes of musculoskeletal disability in the western world. Current available management options provide symptomatic relief (exercise and self-management, medication and surgery) but do not, in general, address the disease process itself. Moreover, adverse effects and complications with some of these interventions (medication and surgery) and the presence of co-morbidities commonly restrict their use. There is clearly a need to investigate treatments that are more widely applicable for symptom management and which may also directly address the disease process itself.</p> <p>In two randomised controlled trials of four and 12 weeks duration, pulsed electrical stimulation was shown to be effective in managing the symptoms of OA of the knee. Laboratory and animal studies demonstrate the capacity of externally applied electric and electromagnetic fields to positively affect chondrocyte proliferation and extracellular matrix protein production. This latter evidence provides strong theoretical support for the use of electrical stimulation to maintain and repair cartilage in the clinical setting and highlights its potential as a disease-modifying modality.</p> <p>Methods/Design</p> <p>A double-blind, randomised, placebo-controlled, repeated measures trial to examine the effectiveness of pulsed electrical stimulation in providing symptomatic relief for people with OA of the knee over 26 weeks.</p> <p>Seventy people will be recruited and information regarding age, gender, body mass index and medication use will be recorded. The population will be stratified for age, gender and baseline pain levels.</p> <p>Outcome measures will include pain (100 mm VAS and WOMAC 3.1), function (WOMAC 3.1), stiffness (WOMAC 3.1), patient global assessment (100 mm VAS) and quality of life (SF-36). These outcomes will be measured at baseline, four, 16 and 26 weeks. Activity levels will be measured at baseline and 16 weeks using accelerometers and the Human Activity Profile questionnaire. A patient global perceived effect scale (11-point Likert) will be completed at 16 and 26 weeks.</p> <p>Discussion</p> <p>This paper describes the protocol for a randomised, double-blind, placebo-controlled trial that will contribute to the evidence regarding the use of sub-sensory pulsed electrical stimulation in the management of OA of the knee.</p> <p>Trial registration</p> <p>Australian Clinical Trials Registry ACTRN12607000492459.</p

    Prospective study of the primary evaluation of 1016 horses with clinical signs of abdominal pain by veterinary practitioners, and the differentiation of critical and non‑critical cases

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    Background: The majority of research on the evaluation of horses with colic is focused on referral hospital populations. Early identification of critical cases is important to optimise outcome and welfare. The aim of this prospective study was to survey the primary evaluation of horses with clinical signs of abdominal pain by veterinary practitioners, and compare the initial presentation of critical and non-critical cases. Results: Data from 1016 primary evaluations of horses presenting with clinical signs of colic were submitted by 167 veterinary practitioners across the United Kingdom over a 13 month period. The mean age of the study population was 13.5 years (median 12.0, range 0–42). Mean heart rate on primary presentation was 47 beats/min (median 44, range 18–125), mean respiratory rate was 20 breaths/min (median 16, range 6–100), and median gastrointestinal auscultation score (0–12, minimum–maximum) was 5 (range 0–12). Clinical signs assessed using a behavioural severity score (0–17, minimum–maximum), were between 0 and 6 in 70.4 % of cases, and 7 12 for 29.6 % of cases. Rectal examination was performed in 73.8 % of cases. Cases that responded positively to simple medical treatment were categorised retrospectively as ‘non-critical’; cases that required intensive medical treatment, surgical intervention, died or were euthanased were categorised as ‘critical’. Eight-hundred-and-twenty- two cases met these criteria; 76.4 % were ‘non-critical’ and 23.6 % were ‘critical’. Multivariable logistic regression was used to identify features of the clinical presentation associated with critical cases. Five variables were retained in the final multivariable model: combined pain score: (OR 1.19, P 2.5 s (OR 3.21, P = 0.046, 95 % CI 1.023–10.09), weak pulse character (OR 2.90, P = 0.004, 95 % CI 1.39–5.99) and absence of gut sounds in ≥1 quadrant (OR 3.65, P < 0.001, 95 % CI 2.08–6.41). Conclusions: This is the first study comparing the primary presentation of critical and non-critical cases of abdominal pain. Pain, heart rate, gastrointestinal borborygmi and simple indicators of hypovolaemia were significant indicators of critical cases, even at the primary veterinary examination, and should be considered essential components of the initial assessment and triage of horses presenting with colic

    Motion dazzle and camouflage as distinct anti-predator defenses.

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    BACKGROUND: Camouflage patterns that hinder detection and/or recognition by antagonists are widely studied in both human and animal contexts. Patterns of contrasting stripes that purportedly degrade an observer's ability to judge the speed and direction of moving prey ('motion dazzle') are, however, rarely investigated. This is despite motion dazzle having been fundamental to the appearance of warships in both world wars and often postulated as the selective agent leading to repeated patterns on many animals (such as zebra and many fish, snake, and invertebrate species). Such patterns often appear conspicuous, suggesting that protection while moving by motion dazzle might impair camouflage when stationary. However, the relationship between motion dazzle and camouflage is unclear because disruptive camouflage relies on high-contrast markings. In this study, we used a computer game with human subjects detecting and capturing either moving or stationary targets with different patterns, in order to provide the first empirical exploration of the interaction of these two protective coloration mechanisms. RESULTS: Moving targets with stripes were caught significantly less often and missed more often than targets with camouflage patterns. However, when stationary, targets with camouflage markings were captured less often and caused more false detections than those with striped patterns, which were readily detected. CONCLUSIONS: Our study provides the clearest evidence to date that some patterns inhibit the capture of moving targets, but that camouflage and motion dazzle are not complementary strategies. Therefore, the specific coloration that evolves in animals will depend on how the life history and ontogeny of each species influence the trade-off between the costs and benefits of motion dazzle and camouflage.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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