Dynamic balance control during treadmill walking in chronic stroke survivors

Maintaining dynamic balance is an important component of walking function that is likely impaired in chronic stroke survivors, evidenced by an increased prevalence of falls. Dynamic balance control requires maintaining the center of mass (COM) within the base of support during movement. During walking, dynamic balance control is achieved largely by modifying foot placement to adjust the base of support. However, chronic stroke survivors have difficulty with both precision control of foot placement, as well as reduced control of COM movement. The objective of this dissertation was to characterize dynamic balance control strategies during walking in chronic stroke survivors. Additionally, we evaluated whether altered sensory feedback could be used to improve balance control in stroke survivors. Dynamic balance control was characterized during challenging walking conditions in stroke survivors and age-matched neurologically intact individuals. Adaptations to perturbations in frontal plane COM, induced using a custom cable-driven device, were used to further probe mechanisms of dynamic balance control. Despite larger amounts of COM movement and step widths, chronic stroke survivors produced a similar ratio of step width to COM sway, indicating that simply increasing step width does not produce a safer walking pattern for the stroke group. Placement of the paretic limb was unchanged in response to the external perturbations of trunk movement, which might underlie deficits in dynamic balance control. Augmented sensory feedback improved paretic foot placement and COM control, when applied during a stepping or treadmill walking task. These results provide insight into differences in dynamic balance control in stroke while also demonstrating that augmented sensory feedback signals might be used to improve balance control, and thus walking function for chronic stroke survivors

Deep Sea Incident: Oil Spill Response Capacity Enhancement using Local Volunteers

Drawing on lessons learned from retrieval of the sunken derelict vessel, the Deep Sea, in Penn Cove, Island County, Washington, June 2012, and anticipation of the potential for an oil spill resulting from the operation, this presentation reflects interdisciplinary collaboration among official responders and community volunteers to enhance spill response capacity, build shared responsibility, and leverage local knowledge and skills. WA DOE Spill Response Section Manager, David Byers, led the incident response team in collaboration with U.S. Coast Guard Federal On-Scene Coordinator, MSTI Jason Munoz. Island County Emergency Management staff led by Eric Brooks informed the response team that the county has a local pool of volunteers trained in nearshore issues through the Washington State University (WSU) Island County Extension Beach Watcher program. The team invited the WSU Island County Beach Watchers Program Coordinator to recruit from among the program’s trained volunteers for individuals willing and able to assist in monitoring for sheen during the retrieval, and able to meet requirements within 48 hours. Volunteers were required to be certified as Emergency Workers, complete a web-based FEMA ICS 100 course and participate in safety training provided by the U.S. Coast Guard. All volunteers had knowledge of the nearshore environment and a few had previous HAZWOPER training but none were actively certified at the time of the incident. Through creative and rapid response on the part of the Coast Guard trainers, the local Emergency Manager and WSU Island County Beach Watchers, 14 volunteers were deployed on the day of retrieval to work in teams led by Coast Guard personnel to monitor segments of the shore. Volunteer participation multiplied the monitoring capacity of Coast Guard personnel and provided practical local knowledge to the response team. Creative collaboration to identify qualified local volunteers and provide essential training in a just-in-time format quickly generated new resources to enhance spill response capacity. This deliberate effort to engage local volunteers in a model of shared responsibility contributed to execution of response itself, created a cadre of informed local volunteers positioned to enhance the community’s understanding of the incident and fostered a positive perception of the incident response

Stroke risk factors in an incident population in urban and rural Tanzania: a prospective, community-based, case-control study

Background The burden of stroke on health systems in low-income and middle-income countries is increasing. However, high-quality data for modifi able stroke risk factors in sub-Saharan Africa are scarce, with no communitybased, case-control studies previously published. We aimed to identify risk factors for stroke in an incident population from rural and urban Tanzania. Methods Stroke cases from urban Dar-es-Salaam and the rural Hai district were recruited in a wider study of stroke incidence between June 15, 2003, and June 15, 2006. We included cases with fi rst-ever and recurrent stroke. Community-acquired controls recruited from the background census populations of the two study regions were matched with cases for age and sex and were interviewed and assessed. Data relating to medical and social history were recorded and blood samples taken. Findings We included 200 stroke cases (69 from Dar-es-Salaam and 131 from Hai) and 398 controls (138 from Dar-es- Salaam and 260 from Hai). Risk factors were similar at both sites, with previous cardiac event (odds ratio [OR] 7·39, 95% CI 2·42–22·53; p<0·0001), HIV infection (5·61, 2·41–13·09; p<0·0001), a high ratio of total cholesterol to HDL cholesterol (4·54, 2·49–8·28; p<0·0001), smoking (2·72, 1·49–4·96; p=0·001), and hypertension (2·14, 1·09–4·17; p=0·026) identifi ed as signifi cant independent risk factors for stroke. In Hai, additional risk factors of diabetes (4·04, 1·29–12·64) and low HDL cholesterol (9·84, 4·06–23·84) were also signifi cant. Interpretation We have identifi ed many of the risk factors for stroke already reported for other world regions. HIV status was an independent risk factor for stroke within an antiretroviral-naive population. Clinicians should be aware of the increased risk of stroke in people with HIV, even in the absence of antiretroviral treatment

Pseudogap and Superconducting Gap in Y-123: A Raman Study

We present results of electronic Raman-scattering experiments in differently doped Y-123. In B2g symmetry, an analysis of the data in terms of a memory function approach is presented and dynamical relaxation rates $\Gamma(\omega,T)$ and mass-enhancement factors $1+\lambda(\omega,T)$ for the carriers are obtained. Starting from temperatures T > 180K, $\Gamma(\omega,T)$ and $1+\lambda(\omega,T)$ are extrapolated to lower temperatures and used to re-calculate Raman spectra. By comparison with our data, we find a loss of spectral weight between Tc < T < T* at all doping levels x. T* is comparable to the pseudogap temperature found in other experiments. Below Tc, the superconducting gap is observed. It depends on x and scales with Tc whereas the energy scale of the pseudogap remains the same.Comment: 5 pages, 5 EPS figures; MOS'99 Proceedings to appear in J. Low Temp. Phy

Polarization and relaxation of radon

Investigations of the polarization and relaxation of $^{209}$Rn by spin exchange with laser optically pumped rubidium are reported. On the order of one million atoms per shot were collected in coated and uncoated glass cells. Gamma-ray anisotropies were measured as a signal of the alignment (second order moment of the polarization) resulting from the combination of polarization and quadrupole relaxation at the cell walls. The temperature dependence over the range 130$^\circ$C to 220$^\circ$C shows the anisotropies increasing with increasing temperature as the ratio of the spin exchange polarization rate to the wall relaxation rate increases faster than the rubidium polarization decreases. Polarization relaxation rates for coated and uncoated cells are presented. In addition, improved limits on the multipole mixing ratios of some of the main gamma-ray transitions have been extracted. These results are promising for electric dipole moment measurements of octupole-deformed $^{223}$Rn and other isotopes, provided sufficient quantities of the rare isotopes can be produced.Comment: 4 pages, 4 figure

A Pilot Study to Determine Whether Disability and Disease Activity Are Different in African-American and Caucasian Patients with Rheumatoid Arthritis in

ABSTRACT. Objective. To compare the levels of disability and disease activity in African-Americans and Caucasians with rheumatoid arthritis (RA) in an academic medical center practice, and to determine whether the differences are independently associated with ethnicity. Methods. Data on socioeconomic, disease related, psychological, and behavioral variables were obtained from 100 outpatients (67 Caucasians, 33 African-Americans) with RA. Functional status was assessed with the Health Assessment Questionnaire (HAQ) and Disease Activity Score (DAS-28). Chi-square and Student t tests were used to test for differences between groups. Multiple regression analysis was used to determine whether ethnicity was associated with these differences independent of other factors known to influence disease outcome. Results. African-Americans and Caucasians did not differ with respect to age, sex, disease duration, rheumatoid factor positivity, and medication compliance. African-Americans had higher scores than Caucasians for HAQ (1.5 ± 0.8 vs 0.9 ± 0.7; p &lt; 0.001) and DAS-28 (5.5 ± 1.3 vs 4.3 ± 1.4; p &lt; 0.001). Regression models showed that ethnicity was not independently associated with the higher HAQ and DAS-28 scores when controlled for demographic, socioeconomic, psychological, and behavioral factors. Arthritis self-efficacy approaches significance in the regression model. Conclusion. HAQ disability and RA disease activity were higher in African-Americans than Caucasians in this sample from an academic medical center practice. However, ethnicity was not independently associated with these outcomes when socioeconomic and psychological factors were taken into account. Improvement in self-efficacy has the potential to improve outcome in AfricanAmericans with RA. (J Rheumatol 2005;32:602-8

A prospective study of stroke sub-type from within an incident population in Tanzania

Objectives. We aimed to establish the pathological types of stroke in two incident populations in Tanzania, one rural and one urban, and to examine the clinical utility of the Siriraj and Allen scores in identifying stroke sub-types. Design. This prospective community-based study identified cases as part of a stroke incidence study. Each patient underwent a full assessment including recording demographic information, taking a medical and drug history, and physical examination. A computed tomography (CT) head scan was used to classify strokes as resulting from a cerebral haemorrhage or ischaemia. The results were compared with the Siriraj and Allen scores, obtained from clinical findings. Results. One hundred and thirty-two incident stroke cases were identified in the rural Hai demographic surveillance site (DSS) and 69 in the urban Dar-es-Salaam DSS; 63 patients with stroke due to ischaemia or cerebral haemorrhage from Hai and 17 from Dar-es-Salaam had a CT scan within 15 days of the stroke. Stroke was identified as due to ischaemia in 52 cases (82.5%) and to cerebral haemorrhage in 11 (17.5%) in Hai, and as due to ischaemia in 14 cases (82.4%) and to cerebral haemorrhage in 3 (17.6%) in Dar-es-Salaam. In both sites Siriraj and Allen scores were found to be of little value in predicting stroke sub-type. Conclusions. The ratio of ischaemic to haemorrhagic stroke is much higher in our cohort than previously reported in sub-Saharan Africa, and is closer to that in high-income countries

Spatiotemporal Variations in Ambient Ultrafine Particles and the Incidence of Childhood Asthma.

Rationale: Little is known regarding the impact of ambient ultrafine particles (UFPs; <0.1 μm) on childhood asthma development. Objectives: To examine the association between prenatal and early postnatal life exposure to UFPs and development of childhood asthma. Methods: A total of 160,641 singleton live births occurring in the City of Toronto, Canada between April 1, 2006, and March 31, 2012, were identified from a birth registry. Associations between exposure to ambient air pollutants and childhood asthma incidence (up to age 6) were estimated using random effects Cox proportional hazards models, adjusting for personal- and neighborhood-level covariates. We investigated both single-pollutant and multipollutant models accounting for coexposures to particulate matter ≤2.5 μm in aerodynamic diameter (PM2.5) and NO2. Measurements and Main Results: We identified 27,062 children with incident asthma diagnosis during the follow-up. In adjusted models, second-trimester exposure to UFPs (hazard ratio per interquartile range increase, 1.09; 95% confidence interval, 1.06-1.12) was associated with asthma incidence. In models additionally adjusted for PM2.5 and nitrogen dioxide, UFPs exposure during the second trimester of pregnancy remained positively associated with childhood asthma incidence (hazard ratio per interquartile range increase, 1.05; 95% confidence interval, 1.01-1.09). Conclusions: This is the first study to evaluate the association between perinatal exposure to UFPs and the incidence of childhood asthma. Exposure to UFPs during a critical period of lung development was linked to the onset of asthma in children, independent of PM2.5 and NO2

Patients with Inflammatory Bowel Disease Exhibit Dysregulated Responses to Microbial DNA

Background: A critical role for the gut epithelium lies in its ability to discriminate between pathogens and commensals and respond appropriately. Dysfunctional interactions between microbes and epithelia are believed to have a role in inflammatory bowel disease (IBD). In this study, we analyzed microbiota and gene expression in IBD patients and examined responses of mucosal biopsies to bacterial DNA. Methods: Biopsies were taken from non-inflamed areas of the colon in healthy controls (HC) and Crohn’s disease (CD) and ulcerative colitis (UC) patients in remission. Biopsies were snap-frozen or cultured with DNA from Lactobacillus plantarum (LP) or Salmonella dublin (SD). Gene expression was analyzed under basal conditions and in response to DNA. Gene networks were analyzed using Ingenuity Pathways software. Mucosal-associated microbiota was analyzed using terminal restriction fragment length polymorphism. Frequency of single nucleotide polymorphisms in NOD2 and TLR9 was assessed. Results: Patients with IBD had altered microbiota, enhanced expression of inflammatory genes, and increased correlations between specific gene expression and microbes. Principle component analysis showed CD and UC patients to cluster independently from healthy controls in both gene expression and microbial analysis. DNA from LP stimulated anti-inflammatory pathways in controls and UC patients, but induced an upregulation of IL17A in CD patients. There were no differences in SNP frequencies of TLR9 or NOD2 in the groups