213 research outputs found

    Allowable Bending Strength Enhancement of 2 By 4 Lumber By Tension and Compression Proofloading

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    Simple 5th percentile and reliability analysis methods were used to evaluate increases in allowable bending strength from proofloading in tension and compression. The analysis included the use of realistic load data for residential roof and floor trusses, and combined stress present in truss chords was given consideration as part of the reliability analysis. Proofloading in tension or in compression both produced significant increases in allowable bending strength for 2 by 4 1650f-1.5E hem-fir. Proofloading in tension to a target 15% breakage level, or 2,838 psi, yielded for the survivors an increase of 72% in allowable bending strength. The allowable bending strength increased 60% because of compressive proofloading to a target 15% breakage level. Since relatively small sample sizes were used, the results are not definitive but provide justification for a comprehensive study

    Parent-reported multi-national study of the impact of congenital and childhood onset myotonic dystrophy

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    Aim: The frequency and impact of symptoms experienced by patients with congenital, childhood, and juvenile-onset myotonic dystrophy (CDM/ChDM/JDM) is not documented. This report identifies symptomatic areas with the greatest disease burden in an international population of patients with early-onset myotonic dystrophy type-1 (DM1). Method: We distributed surveys to parents of patients with CDM/ChDM/JDM. Patients with CDM/ChDM/JDM were members of the US National Registry of DM1 Patients and Family Members, the Canadian Neuromuscular Disease Registry, or the Swedish Health System. Surveys inquired about 325 symptoms and 20 themes associated with CDM/ChDM/JDM. Parents identified the importance of each symptom and theme to their affected child. The prevalence of each symptom and theme were compared across subgroups of patients. The statistical analysis was performed using Fisher\u27s exact and Kruskal–Wallis tests. Results: One hundred and fifty parents returned surveys. The most frequently reported symptomatic themes in children were issues involving communication (81.7%) and problems with hands or fingers (79.6%). Problems with communication and fatigue were the issues that were reported to have the greatest impact on childrens’ lives, while 24.1% of children reported cardiac disorders and 15.8% had problems with anesthesia. Interpretation: A range of symptoms contribute to the burden of disease faced by children with DM1. Many of these symptoms are under-recognized

    Disease Burden and Functional Outcomes in Congenital Myotonic Dystrophy: A Cross-Sectional Study

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    OBJECTIVE: Herein, we describe the disease burden and age-related changes of congenital-onset myotonic dystrophy (CDM) in childhood. METHODS: Children with CDM and age-matched controls aged 0 to 13 years were enrolled. Participants were divided into cohorts based on the following age groups: 0-2, 3-6, and 7-13 years. Each cohort received age-appropriate evaluations including functional testing, oral facial strength testing, neuropsychological testing, quality-of-life measurements, and ECG. Independent-samples t test or Wilcoxon 2-sample test was used to compare the differences between children with CDM and controls. Probability values less than 0.05 are reported as significant. RESULTS: Forty-one participants with CDM and 29 healthy controls were enrolled. The 6-minute walk was significantly different between CDM (258.3 m [SD 176.0]) and control participants (568.2 m [SD 73.2]). The mean lip force strength was significantly different in CDM (2.1 N [SD 2.8)] compared to control participants (17.8 N [SD 7.6]). In participants with CDM, the mean IQ (65.8; SD 18.4) was 3 SDs below the mean compared to standardized norms. Measurements of grip strength, sleep quality, and quality of life were also significantly different. Strength measures (oral facial strength, grip strength, and 6-minute walk) correlated with each other but not with participant IQ. CONCLUSIONS: This work identifies important phenotypes associated with CDM during childhood. Several measures of strength and function were significantly different between participants with CDM and controls and may be useful during future therapeutic trials

    Is Aquatic Life Correlated with an Increased Hematocrit in Snakes?

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    Background: Physiological adaptations that allow air-breathing vertebrates to remain underwater for long periods mainly involve modifications of the respiratory system, essentially through increased oxygen reserves. Physiological constraints on dive duration tend to be less critical for ectotherms than for endotherms because the former have lower mass-specific metabolic rates. Moreover, comparative studies between marine and terrestrial ectotherms have yet to show overall distinct physiological differences specifically associated with oxygen reserves. Methodology/Principal Findings: We used phylogenetically informed statistical models to test if habitat affects hematocrit (an indicator of blood oxygen stores) in snakes, a lineage that varies widely in habitat use. Our results indicate that both phylogenetic position (clade) and especially habitat are significant predictors of hematocrit. Our analysis also confirms the peculiar respiratory physiology of the marine Acrochordus granulatus. Conclusion/Significance: Contrary to previous findings, marine snakes have significantly–albeit slightly–elevated hematocrit, which should facilitate increased aerobic dive times. Longer dives could have consequences for foraging, mate searching, and predation risks. Alternatively, but not exclusively, increased Hct in marine species might also help t

    Disparities in Postacute Rehabilitation Care for Stroke: An Analysis of the State Inpatient Databases

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    Abstract Freburger JK, Holmes GM, Ku L-JE, Cutchin MP, Heatwole-Shank K, Edwards LJ. Disparities in postacute rehabilitation care for stroke: an analysis of the state inpatient databases. Objective To determine the extent to which sociodemographic and geographic disparities exist in the use of postacute rehabilitation care (PARC) after stroke. Design Cross-sectional analysis of data for 2 years (2005–2006) from the State Inpatient Databases. Setting All short-term acute-care hospitals in 4 demographically and geographically diverse states. Participants Individuals (age, ≥45y; mean age, 72.6y) with a primary diagnosis of stroke who survived their inpatient stay (N=187,188). The sample was 52.4% women, 79.5% white, 11.4% black, and 9.1% Hispanic. Interventions Not applicable. Main Outcome Measures (1) Discharge to an institution versus home. (2) For those discharged to home, receipt of home health (HH) versus no HH care. (3) For those discharged to an institution, receipt of inpatient rehabilitation facility (IRF) or skilled nursing facility (SNF) care. Multilevel logistic regression analyses were conducted to identify sociodemographic and geographic disparities in PARC use, controlling for illness severity/comorbid conditions, hospital characteristics, and PARC supply. Results Blacks, women, older individuals, and those with lower incomes were more likely to receive institutional care; Hispanics and the uninsured were less likely. Racial minorities, women, older individuals, and those with lower incomes were more likely to receive HH care; uninsured individuals were less likely. Blacks, women, older individuals, the uninsured, and those with lower incomes were more likely to receive SNF versus IRF care. PARC use varied significantly by hospital and geographic location. Conclusions Several sociodemographic and geographic disparities in PARC use were identified

    Disparities in post-acute rehabilitation care for joint replacement

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    To determine the extent to which demographic and geographic disparities exist in the use of post-acute rehabilitation care (PARC) for joint replacement

    Feasibility and effects of preventive home visits for at-risk older people: Design of a randomized controlled trial

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    Abstract Background The search for preventive methods to mitigate functional decline and unwanted relocation by older adults living in the community is important. Preventive home visit (PHV) models use infrequent but regular visits to older adults by trained practitioners with the goal of maintaining function and quality of life. Evidence about PHV efficacy is mixed but generally supportive. Yet interventions have rarely combined a comprehensive (biopsychosocial) occupational therapy intervention protocol with a home visit to older adults. There is a particular need in the USA to create and examine such a protocol. Methods/Design The study is a single-blind randomized controlled pilot trial designed to assess the feasibility, and to obtain preliminary efficacy estimates, of an intervention consisting of preventive home visits to community-dwelling older adults. An occupational therapy-based preventive home visit (PHV) intervention was developed and is being implemented and evaluated using a repeated measures design. We recruited a sample of 110 from a population of older adults (75+) who were screened and found to be at-risk for functional decline. Participants are currently living in the community (not in assisted living or a skilled nursing facility) in one of three central North Carolina counties. After consent, participants were randomly assigned into experimental and comparison groups. The experimental group receives the intervention 4 times over a 12 month follow-up period while the comparison group receives a minimal intervention of mailed printed materials. Pre- and post-intervention measures are being gathered by questionnaires administered face-to-face by a treatment-blinded research associate. Key outcome measures include functional ability, participation, life satisfaction, self-rated health, and depression. Additional information is collected from participants in the experimental group during the intervention to assess the feasibility of the intervention and potential modifiers. Fidelity is being addressed and measured across several domains. Discussion Feasibility indications to date are positive. Although the protocol has some limitations, we expect to learn enough about the intervention, delivery and effects to support a larger trial with a more stringent design and enhanced statistical power. Trial Registration ClinicalTrials.gov ID NCT0098528

    Evolutionary conservation of lampbrush-like loops in drosophilids

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    <p>Abstract</p> <p>Background</p> <p>Loopin-1 is an abundant, male germ line specific protein of <it>Drosophila melanogaster</it>. The polyclonal antibody T53-F1 specifically recognizes Loopin-1 and enables its visualization on the Y-chromosome lampbrush-like loop named kl-3 during primary spermatocyte development, as well as on sperm tails. In order to test lampbrush-like loop evolutionary conservation, extensive phase-contrast microscopy and immunostaining with T53-F1 antibody was performed in other drosophilids scattered along their genealogical tree.</p> <p>Results</p> <p>In the male germ line of all species tested there are cells showing giant nuclei and intranuclear structures similar to those of <it>Drosophila melanogaster </it>primary spermatocytes. Moreover, the antibody T53-F1 recognizes intranuclear structures in primary spermatocytes of all drosophilids analyzed. Interestingly, the extent and conformation of the staining pattern is species-specific. In addition, the intense staining of sperm tails in all species suggests that the terminal localization of Loopin-1 and its orthologues is conserved. A comparison of these cytological data and the data coming from the literature about sperm length, amount of sperm tail entering the egg during fertilization, shape and extent of both loops and primary spermatocyte nuclei, seems to exclude direct relationships among these parameters.</p> <p>Conclusion</p> <p>Taken together, the data reported strongly suggest that lampbrush-like loops are a conserved feature of primary spermatocyte nuclei in many, if not all, drosophilids. Moreover, the conserved pattern of the T53-F1 immunostaining indicates that a Loopin-1-like protein is present in all the species analyzed, whose localization on lampbrush-like loops and sperm tails during spermatogenesis is evolutionary conserved.</p

    Differing impact of a major biogeographic barrier on genetic structure in two large kangaroos from the monsoon tropics of Northern Australia

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    Tropical savannas cover 20-30% of the world\u27s land surface and exhibit high levels of regional endemism, but the evolutionary histories of their biota remain poorly studied. The most extensive and unmodified tropical savannas occur in Northern Australia, and recent studies suggest this region supports high levels of previously undetected genetic diversity. To examine the importance of barriers to gene flow and the environmental history of Northern Australia in influencing patterns of diversity, we investigated the phylogeography of two closely related, large, vagile macropodid marsupials, the antilopine wallaroo (Macropus antilopinus; n&emsp;=&emsp;78), and the common wallaroo (Macropus robustus; n&emsp;=&emsp;21). Both species are widespread across the tropical savannas of Australia except across the Carpentarian Barrier (CB) where there is a break in the distribution of M.&emsp;antilopinus. We determined sequence variation in the hypervariable Domain I of the mitochondrial DNA control region and genotyped individuals at 12 polymorphic microsatellite loci to assess the historical and contemporary influence of the CB on these species. Surprisingly, we detected only limited differentiation between the disjunct Northern Territory and QueenslandM.&emsp;antilopinus populations. In contrast, the continuously distributedM.&emsp;robustus was highly divergent across the CB. Although unexpected, these contrasting responses appear related to minor differences in species biology. Our results suggest that vicariance may not explain well the phylogeographic patterns in Australia\u27s dynamic monsoonal environments. This is because Quaternary environmental changes in this region have been complex, and diverse individual species\u27 biologies have resulted in less predictable and idiosyncratic responses
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