Identifying Trippers and Non-Trippers Based on Knee Kinematics During Obstacle-Free Walking

Trips are a major cause of falls. Sagittal-plane kinematics affect clearance between the foot and obstacles, however, it is unclear which kinematic measures during obstacle-free walking are associated with avoiding a trip when encountering an obstacle. The purpose of this study was to determine kinematic factors during obstacle-free walking that are related to obstacle avoidance ability. It was expected that successful obstacle avoidance would be associated with greater peak flexion/dorsiflexion and range of motion (ROM), and differences in timing of peak flexion/dorsiflexion during swing of obstacle-free walking for the hip, knee and ankle. Three-dimensional kinematics were recorded as 35 participants (young adults age 18–45 (N = 10), older adults age 65+ without a history of falls (N = 10), older adults age 65+ who had fallen in the last six months (N = 10), and individuals who had experienced a stroke more than six months earlier (N = 5)) walked on a treadmill, under obstacle-free walking conditions with kinematic features calculated for each stride. A separate obstacle avoidance task identified trippers (multiple obstacle contact) and non-trippers. Linear discriminant analysis with sequential feature selection classified trippers and non-trippers based on kinematics during obstacle-free walking. Differences in classification performance and selected features (knee ROM and timing of peak knee flexion during swing) were evaluated between trippers and non-trippers. Non-trippers had greater knee ROM (P = .001). There was no significant difference in classification performance (P = .193). Individuals with reduced knee ROM during obstacle-free walking may have greater difficulty avoiding obstacles

Custom-molded foot-orthosis intervention and multi-segment medial foot kinematics during walking

Context: Foot-orthosis (FO) intervention to prevent and treat numerous lower extremity injuries is widely accepted clinically. However, the results of quantitative gait analyses have been equivocal. The foot models used, participants receiving intervention, and orthoses used might contribute to the variability. Objective: To investigate the effect of a custom-molded FO intervention on multisegment medial foot kinematics during walking in participants with low-mobile foot posture. Design: Crossover study. Setting: University biomechanics and ergonomics laboratory. Patients or Other Participants: Sixteen participants with low-mobile foot posture (7 men, 9 women) were assigned randomly to 1 of 2 FO groups. Intervention(s): After a 2-week period to break in the FOs, individuals participated in a gait analysis that consisted of 5 successful walking trials (1.3 to 1.4 m/s) during no-FO and FO conditions. Main Outcome Measure(s): Three-dimensional displacements during 4 subphases of stance (loading response, mid- stance, terminal stance, preswing) were computed for each multisegment foot model articulation. Results: Repeated-measures analyses of variance (ANO- VAs) revealed that rearfoot complex dorsiflexion displacement during midstance was greater in the FO than the no-FO condition (F114 = 5.24, P=.O4, partial r|2 = 0.27). Terminal stance repeated-measures ANOVA results revealed insert-by-insert condition interactions for the first metatarsophalangeal ¡oint complex (F114=7.87, P=.O1, partial if = 0.36). However, additional follow-up analysis did not reveal differences between the no-FO and FO conditions for the balanced traditional ortho- sis (F, 14 = 4.32, P = .O8, partial if = 0.38) or full-contact orthosis (F1i14 = 4.10, P=.O8, partial if = 0.37). Conclusions: Greater rearfoot complex dorsiflexion during midstance associated with FO intervention may represent improved foot kinematics in people with low-mobile foot postures. Furthermore, FO intervention might partially correct dysfunctional kinematic patterns associated with low-mobile foot postures.

Available Resources of the Fire Clay Coal in Part of the Eastern Kentucky Coal Field

Available resources for the Fire Clay coal were calculated for a 15-quadrangle area in the Eastern Kentucky Coal Field. Original coal resources were estimated to be 1.8 billion tons (BT). Coal mined or lost in mining was estimated at 449 million tons (MT), leaving 1.3 BT of remaining Fire Clay resources in the study area. Of the remaining resources, 400 MT is restricted from mining, primarily because the coal is less than 28 in. thick, normally considered too thin to mine underground using present technology. The total coal available for mining in the study area is 911 MT, or 52 percent of the original resource. Of the 911 MT, 14.9 percent is thicker than 42 in., and only 6.1 percent is accessible by surface-mining methods. The largest block of available coal is in the Leatherwood quadrangle, is less than 42 in. thick, and mostly occurs below drainage

DNA end resection by Dna2–Sgs1–RPA and its stimulation by Top3–Rmi1 and Mre11–Rad50–Xrs2

The repair of DNA double-strand breaks (DSBs) by homologous recombination requires processing of broken ends. For repair to start, the DSB must first be resected to generate a 3′-single-stranded DNA (ssDNA) overhang, which becomes a substrate for the DNA strand exchange protein, Rad51 (ref. 1). Genetic studies have implicated a multitude of proteins in the process, including helicases, nucleases and topoisomerases. Here we biochemically reconstitute elements of the resection process and reveal that it requires the nuclease Dna2, the RecQ-family helicase Sgs1 and the ssDNA-binding protein replication protein-A (RPA). We establish that Dna2, Sgs1 and RPA constitute a minimal protein complex capable of DNA resection in vitro. Sgs1 helicase unwinds the DNA to produce an intermediate that is digested by Dna2, and RPA stimulates DNA unwinding by Sgs1 in a species-specific manner. Interestingly, RPA is also required both to direct Dna2 nucleolytic activity to the 5′-terminated strand of the DNA break and to inhibit 3′ to 5′ degradation by Dna2, actions that generate and protect the 3′-ssDNA overhang, respectively. In addition to this core machinery, we establish that both the topoisomerase 3 (Top3) and Rmi1 complex and the Mre11–Rad50–Xrs2 complex (MRX) have important roles as stimulatory components. Stimulation of end resection by the Top3–Rmi1 heterodimer and the MRX proteins is by complex formation with Sgs1 (refs 5, 6), which unexpectedly stimulates DNA unwinding. We suggest that Top3–Rmi1 and MRX are important for recruitment of the Sgs1–Dna2 complex to DSBs. Our experiments provide a mechanistic framework for understanding the initial steps of recombinational DNA repair in eukaryotes

Public Managers, Media Influence, and Governance: Three Research Traditions Empirically Explored

Nowadays, media and media logic have become important and inherent elements in everyday practices of public administration and policy making. However, the logic of the media is often very different from, and conflicting with, the logic of political and administrative life. So the question of how public managers experience and deal with media attention is more relevant than ever. An analytical sketch of the literature on the relationship between public managers and media provides three main categories of literature (public relations, agenda, and mediatization tradition). These three categories are used to develop statements (so-called Q-sort statements) to capture the way public managers experience thei

Ikaros DNA-Binding Proteins as Integral Components of B Cell Developmental-Stage-Specific Regulatory Circuits

Ikaros DNA-binding proteins are critical for the development of lymphocytes and other hematopoietic lineages, but it remains unclear how they cooperate with other regulators of signaling and transcription to achieve ordered gene expression during development. Here, we show that Ikaros proteins regulate the pre-BCR component λ5 in a stage-specific manner. In pre-BI cells, Ikaros modulated λ5 expression in competition with the transcriptional activator EBF. This required Ikaros binding to the Igll1 (λ5) promoter and was abolished either by mutation of the Ikaros DNA-binding domain or by deletion of a single Ikaros site from the Igll1 promoter. At the transition from the pre-BI to pre-BII stage, the expression of the Ikaros family member Aiolos was upregulated and required for the efficient silencing of Igll1. Aiolos expression was controlled by pre-BCR signals via the adaptor protein SLP-65. Thus, pre-BCR signaling regulates Aiolos and the silencing of Igll1 via a developmental-stage-specific feedback loop

Neighborhood Influences on Perceived Social Support Among Parents: Findings from the Project on Human Development in Chicago Neighborhoods

Background: Social support is frequently linked to positive parenting behavior. Similarly, studies increasingly show a link between neighborhood residential environment and positive parenting behavior. However, less is known about how the residential environment influences parental social support. To address this gap, we examine the relationship between neighborhood concentrated disadvantage and collective efficacy and the level and change in parental caregiver perceptions of non-familial social support. Methodology/Principal Findings: The data for this study came from three data sources, the Project on Human Development in Chicago Neighborhoods (PHDCN) Study's Longitudinal Cohort Survey of caregivers and their offspring, a Community Survey of adult residents in these same neighborhoods and the 1990 Census. Social support is measured at Wave 1 and Wave 3 and neighborhood characteristics are measured at Wave 1. Multilevel linear regression models are fit. The results show that neighborhood collective efficacy is a significant ($\beta$ = .04; SE = .02; p = .03), predictor of the positive change in perceived social support over a 7 year period, however, not of the level of social support, adjusting for key compositional variables and neighborhood concentrated disadvantage. In contrast concentrated neighborhood disadvantage is not a significant predictor of either the level or change in social support. Conclusion: Our finding suggests that neighborhood collective efficacy may be important for inducing the perception of support from friends in parental caregivers over time

Comparison of the efficacy of a neutral wrist splint and wrist splint with lumbrical unit for the treatment of patients with carpal tunnel syndrome

Purpose: The purpose of this study was to compare the effect of a neutral wrist splint or a wrist splint with an additional metacarpophalangeal (MCP) unit on pain, function, grip and pinch strength in patients with mild-to-moderate carpal tunnel syndrome (CTS). Methods: Twenty four patients received conservative treatment using either the neutral wrist splint or wrist splint with the MCP unit for a period of 6 weeks. Primary outcome measures were pain, function, grip and pinch strength. Data was collected immediately before and after using the two types of splints at baseline (0 weeks) and 6 weeks. Statistical analysis was performed using the paired t-test and independent T-test. Results: Compared to baseline, both the neutral wrist splint and the wrist splint with an MCP unit significantly decreased pain, increased function and pinch and grip strength. Comparisons of the two types of splints for grip (P =0.675) and pinch strength (P =0.650) revealed that there were no significant differences between the two after 6 weeks of wear. However, there were significant differences in pain levels (P =0.022) and the DASH score (P =0.027) between the two types of splints from baseline to 6 weeks. Conclusion: The wrist splint with an MCP unit was more effective than the neutral wrist splint in pain reduction and improvement of function

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