Obstacle Crossing in Healthy Young and Older Individuals

Introduction: In the United States, the average population age is rising and will continue to increase in the coming years.With an older population comes increased risk of injury associated with falls. Falls are considered a leading cause of injury and death in older individuals, and many falls are caused by body imbalance or obstacle collision due to a clearly visible stationary object (e.g., rug, chair, branch). Older adults tend to cross obstacles with increased toe clearance in order to prevent tripping, but much of what is known about obstacle crossing in older adults is limited to artificial obstacles that are unique to the laboratory. Currently, there is little data about how older adults cross the varied types of obstacles that are likely encountered during community ambulation. Thus, this study compared measures of obstacle crossing between young and older adults. Methods: Fifteen healthy, older adults (68 ± 6 years) and fifteen healthy, young adults (23 ± 2 years) completed a series of obstructed walking trials within the lab while barefoot. A 3D motion capture system tracked participants while they completed at least ten trials of walking for each obstacle along an 8-meter walkway. Obstacles were presented in a randomized order. Participants were instructed to “walk at a comfortable pace, stepping over the obstacle along the way”. The obstacles were a branch and a parking curb, representing natural obstacles, and a dowel rod, the traditional obstacle in laboratory studies. Vertical and horizontal toe clearance was measured to assess crossing strategies. Results: Older individuals crossed the branch, the curb, and the dowel with increased margins of safety when compared to younger adults, which can be seen through the significantly higher foot clearance, specifically the lead toe clearance (p= .013), and trail toe clearance (p= .001). The curb had a smaller approach and landing distance due to the depth. Regardless of age, the dowel was crossed with a greater margin of safety than the branch and the curb, shown by higher leading and trailing limb toe clearances. The dowel also caused the greatest decrease in gait speed. Discussion: These results show that older individuals increase foot clearance in both the leading and trailing limbs to prevent tripping, supporting the idea that the obstacle is perceived as a greater risk by older individuals. Interestingly, the branch and the curb appear to be less threatening than the dowel rod based on toe clearances. The smaller approach distance and landing distance for the curb, which can be attributed to its depth, suggest step length is maintained across obstacle types, regardless of the increased risk of obstacle contact

Obstacle Crossing in Healthy Young and Older Individuals

Introduction: In the United States, the average population age is rising and will continue to increase in the coming years.With an older population comes increased risk of injury associated with falls. Falls are considered a leading cause of injury and death in older individuals, and many falls are caused by body imbalance or obstacle collision due to a clearly visible stationary object (e.g., rug, chair, branch). Older adults tend to cross obstacles with increased toe clearance in order to prevent tripping, but much of what is known about obstacle crossing in older adults is limited to artificial obstacles that are unique to the laboratory. Currently, there is little data about how older adults cross the varied types of obstacles that are likely encountered during community ambulation. Thus, this study compared measures of obstacle crossing between young and older adults. Methods: Fifteen healthy, older adults (68 ± 6 years) and fifteen healthy, young adults (23 ± 2 years) completed a series of obstructed walking trials within the lab while barefoot. A 3D motion capture system tracked participants while they completed at least ten trials of walking for each obstacle along an 8-meter walkway. Obstacles were presented in a randomized order. Participants were instructed to “walk at a comfortable pace, stepping over the obstacle along the way”. The obstacles were a branch and a parking curb, representing natural obstacles, and a dowel rod, the traditional obstacle in laboratory studies. Vertical and horizontal toe clearance was measured to assess crossing strategies. Results: Older individuals crossed the branch, the curb, and the dowel with increased margins of safety when compared to younger adults, which can be seen through the significantly higher foot clearance, specifically the lead toe clearance (p= .013), and trail toe clearance (p= .001). The curb had a smaller approach and landing distance due to the depth. Regardless of age, the dowel was crossed with a greater margin of safety than the branch and the curb, shown by higher leading and trailing limb toe clearances. The dowel also caused the greatest decrease in gait speed. Discussion: These results show that older individuals increase foot clearance in both the leading and trailing limbs to prevent tripping, supporting the idea that the obstacle is perceived as a greater risk by older individuals. Interestingly, the branch and the curb appear to be less threatening than the dowel rod based on toe clearances. The smaller approach distance and landing distance for the curb, which can be attributed to its depth, suggest step length is maintained across obstacle types, regardless of the increased risk of obstacle contact

SYNCHRONIZATION AND TOWING EFFECT ON ADULT ONE-DOG CANICROSS PERFORMANCE

Canicross is competitive team sport in which a human athlete is towed via a canine athlete on an elastic gangline. Although human performance factors play a role in the success of the canicross team, the interaction between human and canine athletes may also play a crucial role on the performance of the team. The purpose of this study was to assess the synchronization patterns across different locations in competitive canicross events and investigate the influences of canine mass on a timed trial event. Video was taken at five locations along the trail of two different competitive canicross events. Synchronization was mapped and a total synchronization score was given to each of the 19 canicross teams. The results of the current study suggest that neither synchronization score nor human to canine mass ratios were correlated with performance

Racial Conflict In Michael Punke’s The Revenant Novel (2002): A Sociological Perspective

This study is about racial conflict reflected in Michael Punke’s The Revenant (2002). The purpose of this study is to reveal and analyze the issue of the racial conflict based on the Sociological in Literature perspective. The object of this study is The Revenant novel. This study use two kinds of data source: primary and secondary data source. The primary data source is The Revenant (2002) novel written by Michael Punke in English language version. The secondary data source is any references from books, journals, and articles that related to this study. The technique of collecting data is using library reasearch and note taking method. The data of this study are analyzed by using descriptive qualitative method. The result of this study showed that the conflict in this novel fulfilled two criterias of the conflict as the indication i.e. armed attack and victims. Based on the analysis, the racial conflict happened because of an attack started by Arikaras against RMF Company. It gives another conflict to the characters of the novel. Michael Punke wanted to show the conflict issue happened in the society in that time through the historical background of his works including The Revenant

Networked T Cell Death following Macrophage Infection by Mycobacterium tuberculosis

<div><h3>Background</h3><p>Depletion of T cells following infection by <em>Mycobacterium tuberculosis</em> (Mtb) impairs disease resolution, and interferes with clinical test performance that relies on cell-mediated immunity. A number of mechanisms contribute to this T cell suppression, such as activation-induced death and trafficking of T cells out of the peripheral circulation and into the diseased lungs. The extent to which Mtb infection of human macrophages affects T cell viability however, is not well characterised.</p> <h3>Methodology/Principal Findings</h3><p>We found that lymphopenia (<1.5×10⁹ cells/l) was prevalent among culture-positive tuberculosis patients, and lymphocyte counts significantly improved post-therapy. We previously reported that Mtb-infected human macrophages resulted in death of infected and uninfected bystander macrophages. In the current study, we sought to examine the influence of infected human alveolar macrophages on T cells. We infected primary human alveolar macrophages (the primary host cell for Mtb) or PMA-differentiated THP-1 cells with Mtb H37Ra, then prepared cell-free supernatants. The supernatants of Mtb-infected macrophages caused dose-dependent, caspase-dependent, T cell apoptosis. This toxic effect of infected macrophage secreted factors did not require TNF-α or Fas. The supernatant cytotoxic signal(s) were heat-labile and greater than 50 kDa in molecular size. Although ESAT-6 was toxic to T cells, other Mtb-secreted factors tested did not influence T cell viability; nor did macrophage-free Mtb bacilli or broth from Mtb cultures. Furthermore, supernatants from <em>Mycobacterium bovis</em> Bacille de Calmette et Guerin (BCG)- infected macrophages also elicited T cell death suggesting that ESAT-6 itself, although cytotoxic, was not the principal mediator of T cell death in our system.</p> <h3>Conclusions</h3><p>Mtb-Infected macrophages secrete heat-labile factors that are toxic to T cells, and may contribute to the immunosuppression seen in tuberculosis as well as interfere with microbial eradication in the granuloma.</p> </div

Vergleichende Betrachtungen von Pentacarbonylwolframcarbenkomplexen mit ihren organischen Analoga in der intramolekularen Diels-Alder-Reaktion

SIGLEAvailable from TIB Hannover: DW 6737 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A range-dependent analysis of acoustic transmission across a cold filament in the California Current.

CTD data were taken in a area where satellite imagery had detected a cold water filament to frequently recur in the California Current System in order to determine the temporal and spatial variability of the hydrographic and velocity fields. Sound speed profiles were constructed from this data and predicted sonar ranges (PSRs) were computed for passive sonar using a range-dependent parabolic equation model. Analysis of model results applied to tactical scenarios showed the acoustic advantage between two adversaries to change as their positions relative to the front and to each other were changed. An investigation of the acoustic mechanisms involved in the variation of PSRs showed that small variations in surface temperature were enough to cause significant changes in PSRs. Changes in temperature of sufficient magnitude to effect PSRs were found also in SST imagery of cold filaments in other eastern boundary currents around the world.http://archive.org/details/rangedependentan00jendLieutenant Commander, United States NavyApproved for public release; distribution is unlimited

Standardised work-up programme for fever of unknown origin and contribution of magnetic resonance imaging for the diagnosis of hidden systemic vasculitis

Background: Fever of unknown origin (FUO) is a diagnostic challenge. Rheumatologists are often in charge of patients with FUO because the vasculitides, especially, are potential and common causes of FUO. Objective: To evaluate the value of a standardised investigation to identify the cause of FUO. Methods: A standardised work-up programme for patients with FUO was started at the beginning of September 1999. The rate of identified causes of FUO was compared between all patients with FUO admitted to a tertiary care centre of rheumatology between January 1996 and August 1999 (control group) and September 1999 and January 2003 (work-up group). In January 2002 magnetic resonance imaging (MRI) was added to the investigation. Results: 67 patients with FUO were identified—32 before and 35 after institution of the work-up programme. Before implementation 25% of all patients with FUO remained undiagnosed, after implementation 37%. After institution of the investigation the percentage of patients with vasculitides increased significantly from 6% (n = 2) to 26% (n = 9, p = 0.047, Fisher's exact test). This increase could be attributed to the addition of MRI in 2002. When all patients with FUO before 2002 (n = 55) and thereafter (n = 12) were compared the prevalence of systemic vasculitis increased from 11% (n = 6) to 42% (n = 5, p = 0.021). Conclusion: Implementation of a standardised work-up programme for FUO did not improve the overall rate of diagnosis. Addition of MRI significantly increased the diagnosis of systemic vasculitis as the underlying cause of FUO. MRI should be included in the investigation of patients with FUO when vasculitis is suspected