539 research outputs found
Bidirectional association between physical activity and muscular strength in older adults: Results from the UK Biobank study.
BACKGROUND: The relationship between physical activity and muscular strength has not been examined in detail among older adults. The objective of this study was to examine the associations between physical activity and hand grip strength among adults aged ≥ 60 years. METHODS: Using data from the UK Biobank study, we included 66 582 men and women with complete baseline data and 6599 with 4.5 years of follow-up data. We used multiple linear regression models to examine the cross-sectional, longitudinal and bidirectional associations between moderate-to-vigorous physical activity (MVPA) and grip strength, adjusting for potential confounding by age, sex, height, weight, health status, education level, smoking status, Townsend deprivation index and retirement status. RESULTS: In cross-sectional analyses, grip strength and MVPA were linearly and positively associated with each other. Longitudinally, baseline MVPA was not associated with grip strength at follow-up {difference between quintile [Q] 5 and Q1 = 0.40 [95% confidence interval (CI): -0.14, 0.94]kg}, whereas baseline grip strength was associated with MVPA at follow-up [Q5 vs Q1 = 7.15 (1.18, 13.12) min/day]. People who maintained/increased time spent in MVPA did not experience any benefit in grip strength [0.08 (-0.20, 0.37) kg] whereas those who increased their grip strength spent 3.69 (0.20, 7.17) min/day extra in MVPA. CONCLUSION: Promotion of strength-training activities may enable and maintain participation in regular physical activity among older adults.This work was supported by the Medical Research Council [Programme number: MC_UU_12015/4] and has been conducted using the UK Biobank Resource.This is the final version of the article. It first appeared from Oxford University Press via https://doi.org/10.1093/ije/dyw05
Gross-Neveu Models, Nonlinear Dirac Equations, Surfaces and Strings
Recent studies of the thermodynamic phase diagrams of the Gross-Neveu model
(GN2), and its chiral cousin, the NJL2 model, have shown that there are phases
with inhomogeneous crystalline condensates. These (static) condensates can be
found analytically because the relevant Hartree-Fock and gap equations can be
reduced to the nonlinear Schr\"odinger equation, whose deformations are
governed by the mKdV and AKNS integrable hierarchies, respectively. Recently,
Thies et al have shown that time-dependent Hartree-Fock solutions describing
baryon scattering in the massless GN2 model satisfy the Sinh-Gordon equation,
and can be mapped directly to classical string solutions in AdS3. Here we
propose a geometric perspective for this result, based on the generalized
Weierstrass spinor representation for the embedding of 2d surfaces into 3d
spaces, which explains why these well-known integrable systems underlie these
various Gross-Neveu gap equations, and why there should be a connection to
classical string theory solutions. This geometric viewpoint may be useful for
higher dimensional models, where the relevant integrable hierarchies include
the Davey-Stewartson and Novikov-Veselov systems.Comment: 27 pages, 1 figur
Transmutations and spectral parameter power series in eigenvalue problems
We give an overview of recent developments in Sturm-Liouville theory
concerning operators of transmutation (transformation) and spectral parameter
power series (SPPS). The possibility to write down the dispersion
(characteristic) equations corresponding to a variety of spectral problems
related to Sturm-Liouville equations in an analytic form is an attractive
feature of the SPPS method. It is based on a computation of certain systems of
recursive integrals. Considered as families of functions these systems are
complete in the -space and result to be the images of the nonnegative
integer powers of the independent variable under the action of a corresponding
transmutation operator. This recently revealed property of the Delsarte
transmutations opens the way to apply the transmutation operator even when its
integral kernel is unknown and gives the possibility to obtain further
interesting properties concerning the Darboux transformed Schr\"{o}dinger
operators.
We introduce the systems of recursive integrals and the SPPS approach,
explain some of its applications to spectral problems with numerical
illustrations, give the definition and basic properties of transmutation
operators, introduce a parametrized family of transmutation operators, study
their mapping properties and construct the transmutation operators for Darboux
transformed Schr\"{o}dinger operators.Comment: 30 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1111.444
Long-Term Opioid Contract Use for Chronic Pain Management in Primary Care Practice. A Five Year Experience
BACKGROUND: The use of opioid medications to manage chronic pain is complex and challenging, especially in primary care settings. Medication contracts are increasingly being used to monitor patient adherence, but little is known about the long-term outcomes of such contracts. OBJECTIVE: To describe the long-term outcomes of a medication contract agreement for patients receiving opioid medications in a primary care setting. DESIGN: Retrospective cohort study. SUBJECTS: All patients placed on a contract for opioid medication between 1998 and 2003 in an academic General Internal Medicine teaching clinic. MEASUREMENTS: Demographics, diagnoses, opiates prescribed, urine drug screens, and reasons for contract cancellation were recorded. The association of physician contract cancellation with patient factors and medication types were examined using the Chi-square test and multivariate logistic regression. RESULTS: A total of 330 patients constituting 4% of the clinic population were placed on contracts during the study period. Seventy percent were on indigent care programs. The majority had low back pain (38%) or fibromyalgia (23%). Contracts were discontinued in 37%. Only 17% were cancelled for substance abuse and noncompliance. Twenty percent discontinued contract voluntarily. Urine toxicology screens were obtained in 42% of patients of whom 38% were positive for illicit substances. CONCLUSIONS: Over 60% of patients adhered to the contract agreement for opioids with a median follow-up of 22.5 months. Our experience provides insight into establishing a systematic approach to opioid administration and monitoring in primary care practices. A more structured drug testing strategy is needed to identify nonadherent patients
Inhaled nitric oxide alleviates hyperoxia suppressed phosphatidylcholine synthesis in endotoxin-induced injury in mature rat lungs
BACKGROUND: We investigated efficacy of inhaled nitric oxide (NO) in modulation of metabolism of phosphatidylcholine (PC) of pulmonary surfactant and in anti-inflammatory mechanism of mature lungs with inflammatory injury. METHODS: Healthy adult rats were divided into a group of lung inflammation induced by i.v. lipopolysaccharides (LPS) or a normal control (C) for 24 h, and then exposed to: room air (Air), 95% oxygen (O), NO (20 parts per million, NO), both O and NO (ONO) as subgroups, whereas [(3)H]-choline was injected i.v. for incorporation into PC of the lungs which were processed subsequently at 10 min, 4, 8, 12 and 24 h, respectively, for measurement of PC synthesis and proinflammatory cytokine production. RESULTS: LPS-NO subgroup had the lowest level of labeled PC in total phospholipids and disaturated PC in bronchoalveolar lavage fluid and lung tissue (decreased by 46–59%), along with the lowest activity of cytidine triphosphate: phosphocholine cytidylyltransferase (-14–18%) in the lungs, compared to all other subgroups at 4 h (p < 0.01), but not at 8 and 12 h. After 24-h, all LPS-subgroups had lower labeled PC than the corresponding C-subgroups (p < 0.05). LPS-ONO had higher labeled PC in total phospholipids and disaturated PC, activity of cytidylyltransferase, and lower activity of nuclear transcription factor-κB and expression of proinflammatory cytokine mRNA, than that in the LPS-O subgroup (p < 0.05). CONCLUSION: In LPS-induced lung inflammation in association with hyperoxia, depressed PC synthesis and enhanced proinflammatory cytokine production may be alleviated by iNO. NO alone only transiently suppressed the PC synthesis as a result of lower activity of cytidylyltransferase
Simpson's Paradox and the Impact of Different DNMT3A Mutations on Outcome in Younger Adults With Acute Myeloid Leukemia
To evaluate the impact of DNMT3A mutations on outcome in younger patients with cytogenetic intermediate-risk acute myeloid leukemia
Structural and Mechanistic Studies of Measles Virus Illuminate Paramyxovirus Entry
Measles virus (MeV), a member of the paramyxovirus family of enveloped RNA viruses and one of the most infectious viral pathogens identified, accounts for major pediatric morbidity and mortality worldwide although coordinated efforts to achieve global measles control are in place. Target cell entry is mediated by two viral envelope glycoproteins, the attachment (H) and fusion (F) proteins, which form a complex that achieves merger of the envelope with target cell membranes. Despite continually expanding knowledge of the entry strategies employed by enveloped viruses, our molecular insight into the organization of functional paramyxovirus fusion complexes and the mechanisms by which the receptor binding by the attachment protein triggers the required conformational rearrangements of the fusion protein remain incomplete. Recently reported crystal structures of the MeV attachment protein in complex with its cellular receptors CD46 or SLAM and newly developed functional assays have now illuminated some of the fundamental principles that govern cell entry by this archetype member of the paramyxovirus family. Here, we review these advances in our molecular understanding of MeV entry in the context of diverse entry strategies employed by other members of the paramyxovirus family
Optimal Management of the Patient with an Episode of Atrial Fibrillation In and Out of the Hospital
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75668/1/j.1540-8167.1999.tb00696.x.pd
The Formation and Evolution of the First Massive Black Holes
The first massive astrophysical black holes likely formed at high redshifts
(z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations.
These black holes grow by mergers and gas accretion, evolve into the population
of bright quasars observed at lower redshifts, and eventually leave the
supermassive black hole remnants that are ubiquitous at the centers of galaxies
in the nearby universe. The astrophysical processes responsible for the
formation of the earliest seed black holes are poorly understood. The purpose
of this review is threefold: (1) to describe theoretical expectations for the
formation and growth of the earliest black holes within the general paradigm of
hierarchical cold dark matter cosmologies, (2) to summarize several relevant
recent observations that have implications for the formation of the earliest
black holes, and (3) to look into the future and assess the power of
forthcoming observations to probe the physics of the first active galactic
nuclei.Comment: 39 pages, review for "Supermassive Black Holes in the Distant
Universe", Ed. A. J. Barger, Kluwer Academic Publisher
Creating Sources of Inspiration through eCollage, the FEA Model, and a Future Visioning Concept Design Project
This article presents an approach to creating sources of inspiration through a collabora-tive concept design that was developed and observed during a future visioning concept design project concerning the theme of “performance wear,” which was conducted at the University of Helsinki for second-year textile student teachers. During the project, the stu-dents created future scenarios; used the functional, expressive, and aesthetic (FEA) con-sumer needs model for apparel design (Lamb and Kallal in Cloth Text Res J 10(2):42–47, 1992) when considering what performance wear could be like in a future scenario; and cre-ated digital collages (eCollages) to present their concepts. In the course that followed the concept design project, the students designed and made actual clothes using the concepts developed during the concept design project as one of their sources of inspiration. The outcomes of the process are described in this article through four research questions: (1) What type of future scenarios did the teams create, what types of eCollages did the teams make, and how did the teams use information and communication technologies (ICT) in their collages? (2) How did the use of eCollages enrich the concept presentations? (3) How were the three dimensions of the FEA model utilized and presented in the eCollages and team presentations? (4) How did the future visions of the concepts and the eCollages act as sources of inspiration in the students’ clothing designs? Five of the six teams studied created a global future scenario that envisioned the world as a dystopia. The high level of technical and visual executions of all the eCollages was surprising. The ECollages played an important role in every team presentation and enriched them considerably. The FEA model, on the other hand, both provided a supporting framework for the concepts and guided the students to direct their attention to apparel within their future scenarios, as well as to consider different dimensions of it. The concepts especially inspired students to create aesthetic elements to their design and to consider the expressiveness and functionality of the garments from the concept’s perspective. The students also challenged themselves to find technical solutions to design ideas they created through being inspired by the concepts. Furthermore, the students often described gaining inspiration from the story or atmosphere of the concept or other non-visual elements of it, and thereby it seems that our approach indeed succeeded in promoting multi-sensory inspiration.Peer reviewe
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