255 research outputs found
TKA patients with unsatisfying knee function show changes in neuromotor synergy pattern but not joint biomechanics
Nearly 20% of patients who have undergone total knee arthroplasty (TKA) report persistent poor knee function. This study explores the idea that, despite similar knee joint biomechanics, the neuro-motor synergies may be different between high-functional and low-functional TKA patients. We hypothesized that (1) high-functional TKA recruit a more complex neuro-motor synergy pattern compared to low-functional TKA and (2) high-functional TKA patients demonstrate more stride-to-stride variability (flexibility) in their synergies.
Gait and electromyography (EMG) data were collected during level walking for three groups of participants: (i) high-functional TKA patients (n = 13); (ii) low-functional TKA patients (n = 13) and (iii) non-operative controls (n = 18). Synergies were extracted from EMG data using non-negative matrix factorization. Analysis of variance and Spearman correlation analyses were used to investigate between-group differences in gait and neuro-motor synergies.
Results showed that synergy patterns were different among the three groups. Control subjects used 5–6 independent neural commands to execute a gait cycle. High functional TKA patients used 4–5 independent neural commands while low-functional TKA patients relied on only 2–3 independent neural commands to execute a gait cycle. Furthermore, stride-to-stride variability of muscles’ response to the neural commands was reduced up to 15% in low-functional TKAs compared to the other two groups
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Second Primary Malignant Neoplasms and Survival in Adolescent and Young Adult Cancer Survivors.
Importance: Although the increased incidence of second primary malignant neoplasms (SPMs) is a well-known late effect after cancer, few studies have compared survival after an SPM to survival of the same cancer occurring as first primary malignant neoplasm (PM) by age.
Objective: To assess the survival impact of SPMs in adolescents and young adults (AYAs) (15-39 years) compared with that of pediatric (\u3c15 \u3eyears) and older adult (≥40 years) patients with the same SPMs.
Design, Setting, and Participants: This was a population-based, retrospective cohort study of patients with cancer in 13 Surveillance, Epidemiology and End Results regions in the United States diagnosed from 1992 to 2008 and followed through 2013. Data analysis was performed between June 2016 and January 2017.
Main Outcomes and Measures: Five-year relative survival was calculated overall and for each cancer occurring as a PM or SPM by age at diagnosis. The impact of SPM status on cancer-specific death was examined using multivariable Cox proportional hazards regression.
Results: A total of 15 954 pediatric, 125 750 AYAs, and 878 370 older adult patients diagnosed as having 14 cancers occurring as a PM or SPM were included. Overall, 5-year survival after an SPM was 33.1% lower for children, 20.2% lower for AYAs, and 8.3% lower for older adults compared with a PM at the same age. For the most common SPMs in AYAs, the absolute difference in 5-year survival was 42% lower for secondary non-Hodgkin lymphoma, 19% for secondary breast carcinoma, 15% for secondary thyroid carcinoma, and 13% for secondary soft-tissue sarcoma. Survival by SPM status was significantly worse in younger vs older patients for thyroid, Hodgkin lymphoma, non-Hodgkin lymphoma, acute myeloid leukemia, soft-tissue sarcoma, and central nervous system cancer. Adolescents and young adults with secondary Hodgkin lymphoma (hazard ratio [95% CI], 3.5 [1.7-7.1]); soft-tissue sarcoma (2.8 [2.1-3.9]); breast carcinoma (2.1 [1.8-2.4]); acute myeloid leukemia (1.9 [1.5-2.4]); and central nervous system cancer (1.8 [1.2-2.8]) experienced worse survival compared with AYAs with the same PMs.
Conclusion and Relevance: The adverse impact of SPMs on survival is substantial for AYAs and may partially explain the relative lack of survival improvement in AYAs compared with other age groups. The impact of a particular SPM diagnosis on survival may inform age-specific prevention, screening, treatment, and survivorship recommendations
The ACS Survey of Galactic Globular Clusters: M54 and Young Populations in the Sagittarius Dwarf Spheroidal Galaxy
We present new Hubble Space Telescope photometry of the massive globular
cluster M54 (NGC 6715) and the superposed core of the tidally disrupted
Sagittarius (Sgr) dSph galaxy as part of the ACS Survey of Galactic Globular
Clusters. Our deep (F606W~26.5), high-precision photometry yields an
unprecedentedly detailed color-magnitude diagram showing the extended blue
horizontal branch and multiple main sequences of the M54+Sgr system. The
distance and reddening to M54 are revised usingboth isochrone and main-sequence
fitting to (m-M)_0=17.27 and E(B-V)=0.15. Preliminary assessment finds the
M54+Sgr field to be dominated by the old metal-poor populations of Sgr and the
globular cluster. Multiple turnoffs indicate the presence of at least two
intermediate-aged star formation epochs with 4 and 6 Gyr ages and [Fe/H]=-0.4
to -0.6. We also clearly show, for the first time, a prominent, 2.3 Gyr old Sgr
population of near-solar abundance. A trace population of even younger (0.1-0.8
Gyr old), more metal-rich ([Fe/H]\sim0.6) stars is also indicated. The Sgr
age-metallicity relation is consistent with a closed-box model and multiple
(4-5) star formation bursts over the entire life of the satellite, including
the time since Sgr began disrupting.Comment: Accepted to ApJ Letter; 11 pages, 2 figures; figure 1 uploaded as
jpg; paper in ApJ format with full-resolution figures available at:
http://www.astro.ufl.edu/~ata/public_hstgc/paperIV/paperIV.p
The Stride program: Feasibility and pre-to-post program change of an exercise service for university students experiencing mental distress
Rates of mental illness are disproportionately high for young adult and higher education (e.g., university student) populations. As such, universities and tertiary institutions often devote significant efforts to services and programs that support and treat mental illness and/or mental distress. However, within that portfolio of treatment approaches, structured exercise has been relatively underutilised and greater research attention is needed to develop this evidence base. The Stride program is a structured 12-week exercise service for students experiencing mental distress. We aimed to explore the feasibility of the program and assess pre- and post-program change, through assessments of student health, lifestyle, and wellbeing outcomes. Drawing from feasibility and effectiveness-implementation hybrid design literatures, we conducted a non-randomised feasibility trial of the Stride program. Participants were recruited from the Stride program (N = 114, Mage = 24.21 years). Feasibility results indicated the program was perceived as acceptable and that participants reported positive perceptions of program components, personnel, and sessions. Participants’ pre-to-post program change in depressive symptomatology, physical activity levels, mental health-related quality of life, and various behavioural outcomes were found to be desirable. Our results provide support for the feasibility of the Stride program, and more broadly for the delivery and potential effectiveness of structured exercise programs to support university students experiencing mental distress
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Whole exome sequencing identifies a recurrent NAB2-STAT6 fusion in solitary fibrous tumors
Phylotastic! Making Tree-of-Life Knowledge Accessible, Reusable and Convenient
Scientists rarely reuse expert knowledge of phylogeny, in spite of years of effort to assemble a great "Tree of Life" (ToL). A notable exception involves the use of Phylomatic, which provides tools to generate custom phylogenies from a large, pre-computed, expert phylogeny of plant taxa. This suggests great potential for a more generalized system that, starting with a query consisting of a list of any known species, would rectify non-standard names, identify expert phylogenies containing the implicated taxa, prune away unneeded parts, and supply branch lengths and annotations, resulting in a custom phylogeny suited to the user's needs. Such a system could become a sustainable community resource if implemented as a distributed system of loosely coupled parts that interact through clearly defined interfaces. Results: With the aim of building such a "phylotastic" system, the NESCent Hackathons, Interoperability, Phylogenies (HIP) working group recruited 2 dozen scientist-programmers to a weeklong programming hackathon in June 2012. During the hackathon (and a three-month follow-up period), 5 teams produced designs, implementations, documentation, presentations, and tests including: (1) a generalized scheme for integrating components; (2) proof-of-concept pruners and controllers; (3) a meta-API for taxonomic name resolution services; (4) a system for storing, finding, and retrieving phylogenies using semantic web technologies for data exchange, storage, and querying; (5) an innovative new service, DateLife.org, which synthesizes pre-computed, time-calibrated phylogenies to assign ages to nodes; and (6) demonstration projects. These outcomes are accessible via a public code repository (GitHub.com), a website (www.phylotastic.org), and a server image. Conclusions: Approximately 9 person-months of effort (centered on a software development hackathon) resulted in the design and implementation of proof-of-concept software for 4 core phylotastic components, 3 controllers, and 3 end-user demonstration tools. While these products have substantial limitations, they suggest considerable potential for a distributed system that makes phylogenetic knowledge readily accessible in computable form. Widespread use of phylotastic systems will create an electronic marketplace for sharing phylogenetic knowledge that will spur innovation in other areas of the ToL enterprise, such as annotation of sources and methods and third-party methods of quality assessment.NESCent (the National Evolutionary Synthesis Center)NSF EF-0905606iPlant Collaborative (NSF) DBI-0735191Biodiversity Synthesis Center (BioSync) of the Encyclopedia of LifeComputer Science
Discovery of charge density wave in a correlated kagome lattice antiferromagnet
A hallmark of strongly correlated quantum materials is the rich phase diagram
resulting from competing and intertwined phases with nearly degenerate ground
state energies. A well-known example is the copper oxides, where a charge
density wave (CDW) is ordered well above and strongly coupled to the magnetic
order to form spin-charge separated stripes that compete with
superconductivity. Recently, such rich phase diagrams have also been revealed
in correlated topological materials. In two-dimensional kagome lattice metals
consisting of corner-sharing triangles, the geometry of the lattice can produce
flat bands with localized electrons, non-trivial topology, chiral magnetic
order, superconductivity and CDW order. While CDW has been found in weakly
electron correlated nonmagnetic AV3Sb5 (A = K, Rb, Cs), it has not yet been
observed in correlated magnetic ordered kagome lattice metals. Here we report
the discovery of CDW within the antiferromagnetic (AFM) ordered phase of kagome
lattice FeGe. The CDW in FeGe occurs at wavevectors identical to that of
AV3Sb5, enhances the AFM ordered moment, and induces an emergent anomalous Hall
effect. Our findings suggest that CDW in FeGe arises from the combination of
electron correlations-driven AFM order and van Hove singularities-driven
instability possibly associated with a chiral flux phase, in stark contrast to
strongly correlated copper oxides and nickelates, where the CDW precedes or
accompanies the magnetic order.Comment: 36 pages, 4 figures in main tex
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