620 research outputs found
Applicability of trials in rheumatoid arthritis and osteoarthritis: A systematic review and meta-analysis of trial populations showing adequate proportion of women, but underrepresentation of elderly people
Objectives: To evaluate whether elderly people and women are adequately represented in randomized controlled trials (RCT) in rheumatoid arthritis (RA) and osteoarthritis (OA). Methods: Four systematic searches in MEDLINE yielded RCT in RA and OA on any intervention published in 2016 and 2017 and population-based studies (PBS) in RA and OA published between 2013 and 2017. Random effects meta-analyses estimated the pooled proportion of elderly people (defined as being ≥ 65 years old), the mean age, its standard deviation (SD), and the proportion of women stratified by disease (RA and OA) and study type (RCT and PBS). Stratified estimates were subsequently compared. Results: 265 RCT comprising 51,240 participants and 53 PBS comprising 523,630 participants were included. In both RA and OA, RCT included lower proportions of elderly people than PBS: RA –0.18 (95% confidence interval –0.22 to –0.13); OA –0.20 (–0.30 to –0.09); had lower mean ages: RA –5.2 years (–6.8 to –3.5); OA –4.7 years (–7.5 to –2.0); and smaller SD: RA –1.9 years (–2.6 to –1.3); OA –2.7 years (–4.2 to –1.2); (all comparisons: p ≤ 0.001). Proportions of women were comparable in RCT compared to PBS in both RA and OA. Conclusions: While women are adequately represented in RA and OA trials, the elderly are underrepresented, probably limiting applicability of current evidence to this growing subgroup. It is urgent to improve the inclusion of elderly people in clinical trials and study age as a determinant for outcome
The perfect action for non-degenerate staggered fermions
The perfect action of free staggered fermions is calculated by blocking from
the continuum for degenerate and non-degenerate flavor masses. The symmetry
structure, connecting flavor transformations and translations, is explained
directly from the blocking scheme. It is convenient to use a modified Fourier
transformation, respecting this connection, to treat the spin-flavor structure
of the blockspins. The perfect action remains local in the non-degenerate case;
it is explicitly calculated in two dimensions. I finally comment on the
relation of the blocking scheme to the transition from Dirac-K\"ahler fermions
to staggered fermions.Comment: 14 pages, Latex2e, 1 Latex figure, some minor changes and two
references adde
The risk associated with spinal manipulation:an overview of reviews
BACKGROUND: Spinal manipulative therapy (SMT) is a widely used manual treatment, but many reviews exist with conflicting conclusions about the safety of SMT. We performed an overview of reviews to elucidate and quantify the risk of serious adverse events (SAEs) associated with SMT. METHODS: We searched five electronic databases from inception to December 8, 2015. We included reviews on any type of studies, patients, and SMT technique. Our primary outcome was SAEs. Quality of the included reviews was assessed using a measurement tool to assess systematic reviews (AMSTAR). Since there were insufficient data for calculating incidence rates of SAEs, we used an alternative approach; the conclusions regarding safety of SMT were extracted for each review, and the communicated opinion were judged by two reviewers independently as safe, harmful, or neutral/unclear. Risk ratios (RRs) of a review communicating that SMT is safe and meeting the requirements for each AMSTAR item, were calculated. RESULTS: We identified 283 eligible reviews, but only 118 provided data for synthesis. The most frequently described adverse events (AEs) were stroke, headache, and vertebral artery dissection. Fifty-four reviews (46%) expressed that SMT is safe, 15 (13%) expressed that SMT is harmful, and 49 reviews (42%) were neutral or unclear. Thirteen reviews reported incidence estimates for SAEs, roughly ranging from 1 in 20,000 to 1 in 250,000,000 manipulations. Low methodological quality was present, with a median of 4 of 11 AMSTAR items met (interquartile range, 3 to 6). Reviews meeting the requirements for each of the AMSTAR items (i.e. good internal validity) had a higher chance of expressing that SMT is safe. CONCLUSIONS: It is currently not possible to provide an overall conclusion about the safety of SMT; however, the types of SAEs reported can indeed be significant, sustaining that some risk is present. High quality research and consistent reporting of AEs and SAEs are needed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015030068. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13643-017-0458-y) contains supplementary material, which is available to authorized users
Postpartum dysgalactia syndrome in sows: effects on behavior of sows and piglets
Background To investigate if specific sow and piglet behavioral characteristics could be used diagnostically, this case-cohort study of the behavior of sows and piglets during the periparturient period (from 24 h before the birth of first piglet to 24 h after the birth of last piglet) was conducted. Data included 32 sows diagnosed with PDS (PDS+) vs. 37 healthy matched controls (PDS-) and their litters. Results A significant change from active behavior with many postural changes to a more passive behavior was noted in connection with parturition. Sow nesting behavior was less frequent in PDS+ sows compared to PDS- sows during (p = 0.04) and after parturition (p = 0.0004). No difference was found between PDS+ and PDS- in the number of postural changes, interval from last time standing to the birth of the first piglet, interval from last time eating/drinking to the birth of the first piglet, interval from the birth of the first piglet to the sow standing after farrowing, interval from the birth of the last piglet until eating/drinking, occurrence of bar biting, or frequency or duration of eating/drinking during the observation period. Piglets of PDS+ sows stayed outside the creep areas more often than piglets of PDS- sows (p < 0.0001), but there was no difference in the mean number of piglets observed massaging the udder every 10 min. Conclusion These results confirm that sow behavior changes from active before parturition to more passive after parturition. Being diagnosed with PDS affected the periparturient behavior of sows as well as their piglets. The observed reduction in nesting behavior in PDS+ sows may suggest that a highly motivated piglet-oriented behavior was affected. However, classical sickness behaviors like lethargy and passivity seem to be poor markers for PDS
Processed meat intake and chronic disease morbidity and mortality:An overview of systematic reviews and meta-analyses
Despite the nutritional value of meat, a large volume of reviews and meta-analyses suggests that processed meat intake is associated with an increased risk of chronic diseases. However, assessments of the quality of these published reviews internal validity are generally lacking. We systematically reviewed and assessed the quality alongside summarizing the results of previously published systematic reviews and meta-analyses that examined the association between processed meat intake and cancers, type II diabetes (T2D), and cardiovascular diseases (CVD). Reviews and meta-analyses published until May 2018 were identified through a systematic literature search in the databases MEDLINE and EMBASE, and reference lists of included reviews. The quality of the systematic reviews and meta-analyses was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR). All eligible reviews had to comply with two quality requirements: providing sufficient information on quality assessment of the primary studies and a comprehensive search. The results were summarized for T2D, CVD, and each of the different cancer types. The certainty in the estimates of the individual outcomes was rated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method. In total, 22 systematic reviews were eligible and thus included in this review. More than 100 reviews were excluded because quality assessment of the primary studies had not been performed. The AMSTAR score of the included reviews ranged from 5 to 8 indicating moderate quality. Overall, the quality assessments of primary studies of the reviews are generally lacking; the scientific quality of the systematic reviews reporting positive associations between processed meat intake and risk of various cancers, T2D and CVD is moderate, and the results from case-control studies suggest more often a positive association than the results from cohort studies. The overall certainty in the evidence was very low across all individual outcomes, due to serious risk of bias and imprecision
A Perturbative Construction of Lattice Chiral Fermions
We perform a renormalization group transformation to construct a lattice
theory of chiral fermions. The field variables of the continuum theory are
averaged over hypercubes to define lattice fields. Integrating out the
continuum variables in perturbation theory we derive a chirally invariant
effective action for the lattice fields. This is consistent with the
Nielsen-Niniomiya theorem because the effective action is nonlocal. We also
construct the axial current on the lattice and we show that the axial anomaly
of the continuum theory is reproduced in the Schwinger model. This shows that
chiral fermions can be regularized on the lattice.Comment: 8 pages, LaTe
Speed of disentanglement in multi-qubit systems under depolarizing channel
We investigate the speed of disentanglement in the multiqubit systems under
the local depolarizing channel, in which each qubit is independently coupled to
the environment. We focus on the bipartition entanglement between one qubit and
the remaining qubits constituting the system, which is measured by the
negativity. For the two-qubit system, the speed for the pure state completely
depends on its entanglement. The upper and lower bounds of the speed for
arbitrary two-qubit states, and the necessary conditions for a state achieving
them, are obtained. For the three-qubit system, we study the speed for pure
states, whose entanglement properties can be completely described by five
local-unitary-transformation invariants. An analytical expression of the
relation between the speed and the invariants is derived. The speed is enhanced
by the the three-tangle which is the entanglement among the three qubits, but
reduced by the the two-qubit correlations outside of the concurrence. The decay
of the negativity can be restrained by the other two negativity with the
coequal sense. The unbalance between two qubits can reduce speed of
disentanglement of the remaining qubit in the system, even can retrieve the
entanglement partially. For the k-qubit systems in an arbitrary superposition
of GHZ state and W state, the speed depends almost entirely on the amount of
the negativity when k increases to five or six. An alternative quantitative
definition for the robustness of entanglement is presented based on the speed
of disentanglement, with comparison to the widely studied robustness measured
by the critical amount of noise parameter where the entanglement vanishes. In
the limit of large number of particles, the alternative robustness of the
GHZ-type states is inversely proportional to k, and the one of the W states
approaches 1/\sqrt{k}.Comment: 14 pages, 5 figures. to appear in Annals of Physic
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