70 research outputs found

    Office-based optical coherence tomographic imaging of human vocal cords

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    Optical coherence tomography (OCT) is an evolving noninvasive imaging modality and has been used to image the larynx during surgical endoscopy. The design of an OCT sampling device capable of capturing images of the human larynx during a typical office based laryngoscopy examination is discussed. Both patient’s and physician\u27s movements were addressed. In vivo OCT imaging of the human larynx is demonstrated. Though the long focal length limits the lateral resolution of the image, the basement membrane can still be readily distinguished. Office-based OCT has the potential to guide surgical biopsies, direct therapy, and monitor disease. This is a promising imaging modality to study the larynx

    Report on the May-June 2002 Englebright Lake deep coring campaign

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    This report describes the May-June 2002 Englebright Lake coring project. Englebright Lake is a 14-km-long reservoir on the Yuba River of northern California, impounded by Englebright Dam, which was completed in 1940. The sediments were cored to assess the current conditions in the reservoir as part of the California Bay-Delta Authority’s Upper Yuba River Studies Program. Sediment was collected using both hydraulic-piston and rotational coring equipment mounted on a floating drilling platform. Thirty boreholes were attempted at 7 sites spaced along the longitudinal axis of the reservoir. Complete sedimentary sections were recovered from 20 boreholes at 6 sites. In total, 335 m of sediment was cored, with 86% average recovery. The core sections (each up to 1.5 m long) were processed using a standard set of laboratory techniques, including geophysical logging of physical properties, splitting, visual descriptions, digital photography, and initial subsampling. This report presents the results of these analyses in a series of stratigraphic columns. Using the observed stratigraphy as a guide, several series of subsamples were collected for various sedimentologic, geochemical, and geochronological analyses. The results of laboratory analyses of most of these subsamples will be presented in future reports and articles

    HABITAT: A longitudinal multilevel study of physical activity change in mid-aged adults

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    Purpose. To explore the role of the neighborhood environment in supporting walking Design. Cross sectional study of 10,286 residents of 200 neighborhoods. Participants were selected using a stratified two-stage cluster design. Data were collected by mail survey (68.5% response rate). Setting. The Brisbane City Local Government Area, Australia, 2007. Subjects. Brisbane residents aged 40 to 65 years. Measures. Environmental: street connectivity, residential density, hilliness, tree coverage, bikeways, and street lights within a one kilometer circular buffer from each resident’s home; and network distance to nearest river or coast, public transport, shop, and park. Walking: minutes in the previous week categorized as < 30 minutes, ≥ 30 < 90 minutes, ≥ 90 < 150 minutes, ≥ 150 < 300 minutes, and ≥ 300 minutes. Analysis. The association between each neighborhood characteristic and walking was examined using multilevel multinomial logistic regression and the model parameters were estimated using Markov chain Monte Carlo simulation. Results. After adjustment for individual factors, the likelihood of walking for more than 300 minutes (relative to <30 minutes) was highest in areas with the most connectivity (OR=1.93, 99% CI 1.32-2.80), the greatest residential density (OR=1.47, 99% CI 1.02-2.12), the least tree coverage (OR=1.69, 99% CI 1.13-2.51), the most bikeways (OR=1.60, 99% CI 1.16-2.21), and the most street lights (OR=1.50, 99% CI 1.07-2.11). The likelihood of walking for more than 300 minutes was also higher among those who lived closest to a river or the coast (OR=2.06, 99% CI 1.41-3.02). Conclusion. The likelihood of meeting (and exceeding) physical activity recommendations on the basis of walking was higher in neighborhoods with greater street connectivity and residential density, more street lights and bikeways, closer proximity to waterways, and less tree coverage. Interventions targeting these neighborhood characteristics may lead to improved environmental quality as well as lower rates of overweight and obesity and associated chromic disease

    Retinoic Acid Restores Adult Hippocampal Neurogenesis and Reverses Spatial Memory Deficit in Vitamin A Deprived Rats

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    A dysfunction of retinoid hippocampal signaling pathway has been involved in the appearance of affective and cognitive disorders. However, the underlying neurobiological mechanisms remain unknown. Hippocampal granule neurons are generated throughout life and are involved in emotion and memory. Here, we investigated the effects of vitamin A deficiency (VAD) on neurogenesis and memory and the ability of retinoic acid (RA) treatment to prevent VAD-induced impairments. Adult retinoid-deficient rats were generated by a vitamin A-free diet from weaning in order to allow a normal development. The effects of VAD and/or RA administration were examined on hippocampal neurogenesis, retinoid target genes such as neurotrophin receptors and spatial reference memory measured in the water maze. Long-term VAD decreased neurogenesis and led to memory deficits. More importantly, these effects were reversed by 4 weeks of RA treatment. These beneficial effects may be in part related to an up-regulation of retinoid-mediated molecular events, such as the expression of the neurotrophin receptor TrkA. We have demonstrated for the first time that the effect of vitamin A deficient diet on the level of hippoccampal neurogenesis is reversible and that RA treatment is important for the maintenance of the hippocampal plasticity and function

    Randomised controlled trial of a secondary prevention program for myocardial infarction patients ('ProActive Heart'): study protocol. Secondary prevention program for myocardial infarction patients

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    Background: \ud Coronary heart disease (CHD) is a significant cause of health and economic burden. Secondary prevention programs play a pivotal role in the treatment and management of those affected by CHD although participation rates are poor due to patient, provider, health system and societal-level barriers. As such, there is a need to develop innovative secondary prevention programs to address the treatment gap. Telephone-delivered care is convenient, flexible and has been shown to improve behavioural and clinical outcomes following myocardial infarction (MI). This paper presents the design of a randomised controlled trial to evaluate the efficacy of a six-month telephone-delivered secondary prevention program for MI patients (ProActive Heart).\ud \ud Methods:\ud 550 adult MI patients have been recruited over a 14 month period (December 2007 to January 2009) through two Brisbane metropolitan hospitals, and randomised to an intervention or control group (n = 225 per group). The intervention commences within two weeks of hospital discharge delivered by study-trained health professionals ('health coaches') during up to 10 × 30 minute scripted telephone health coaching sessions. Participants also receive a ProActive Heart handbook and an educational resource to use during the health coaching sessions. The intervention focuses on appropriate modification of CHD risk factors, compliance with pharmacological management, and management of psychosocial issues. Data collection occurs at baseline or prior to commencement of the intervention (Time 1), six months follow-up or the completion of the intervention (Time 2), and at 12 months follow-up for longer term outcomes (Time 3). Primary outcome measures include quality of life (Short Form-36) and physical activity (Active Australia Survey). A cost-effective analysis of the costs and outcomes for patients in the intervention and control groups is being conducted from the perspective of health care costs to the government.\ud \ud Discussion: The results of this study will provide valuable new information about an innovative telephone-delivered cost-effective secondary prevention program for MI patients

    Effects of an eight-week supervised, structured lifestyle modification programme on anthropometric, metabolic and cardiovascular risk factors in severely obese adults

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    Background: Lifestyle modification is fundamental to obesity treatment, but few studies have described the effects of structured lifestyle programmes specifically in bariatric patients. We sought to describe changes in anthropometric and metabolic characteristics in a cohort of bariatric patients after participation in a nurse-led, structured lifestyle programme. Methods: We conducted a retrospective, observational cohort study of adults with a body mass index (BMI) ≥40 kgm−2 (or ≥35 kgm−2 with significant co-morbidity) who were attending a regional bariatric service and who completed a single centre, 8-week, nurse-led multidisciplinary lifestyle modification programme. Weight, height, waist circumference, blood pressure, HbA1c, fasting glucose and lipid profiles as well as functional capacity (Incremental Shuttle Walk Test) and questionnaire-based anxiety and depression scores before and after the programme were compared in per-protocol analyses. Results: Of 183 bariatric patients enrolled, 150 (81.9 %) completed the programme. Mean age of completers was 47.9 ± 11.2 years. 34.7 % were male. There were statistically significant reductions in weight (129.6 ± 25.9 v 126.9 ± 26.1 kg, p < 0.001), BMI (46.3 ± 8.3 v 44.9 ± 9.0 kgm−2, p < 0.001), waist circumference (133.0 ± 17.1 v 129.3 ± 17.5 cm in women and 143.8 ± 19.0 v 135.1 ± 17.9 cm in men, both p < 0.001) as well as anxiety and depression scores, total- and LDL-cholesterol and triglyceride levels, with an increase in functional capacity (5.9 ± 1.7 v 6.8 ± 2.1 metabolic equivalents of thermogenesis (METS), p < 0.001) in completers at the end of the programme compared to the start. Blood pressure improved, with reductions in systolic and diastolic blood pressure from 135 ± 16.2 to 131.6 ± 17.1 (p = 0.009) and 84.7 ± 10.2 to 81.4 ± 10.9 mmHg (p < 0.001), respectively. The proportion of patients achieving target blood pressure increased from 50.3 to 59.3 % (p = 0.04). The proportion of patients with diabetes achieving HbA1c <53 mmol/mol increased from 28.6 to 42.9 %, p = 0.02. (Continued on next page)Conclusions: Bariatric patients completing an 8 week, nurse-led structured lifestyle programme had improved adiposity, fitness, lipid profiles, psychosocial health, blood pressure and glycaemia. Further assessment of this programme in a pragmatic randomised controlled trial seems warranted. Keywords: Bariatric, Structured lifestyle modification, Cardiovascular risk, CLANN (Changing Lifestyle with Activity and Nutrition) Programme, Nurse-led, Diabete

    The influence of dog ownership on objective measures of free-living physical activity and sedentary behaviour in community-dwelling older adults : a longitudinal case-controlled study

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    Background: There is some evidence to suggest that dog ownership may improve physical activity (PA) among older adults, but to date, studies examining this, have either depended on self-report or incomplete datasets due to the type of activity monitor used to record physical activity. Additionally, the effect of dog ownership on sedentary behaviour (SB) has not been explored. The aim of the current study was to address these issues by using activPAL monitors to evaluate the influence of dog ownership on health enhancing PA and SB in a longitudinal study of independently-mobile, community-dwelling older adults. Methods: Study participants (43 pairs of dog owners and non-dog owners, matched on a range of demographic variables) wore an activPAL monitor continuously for three, one-week data collection periods over the course of a year. Participants also reported information about their own and their dog demographics, caring responsibilities, and completed a diary of wake times. Diary data was used to isolate waking times, and outcome measures of time spent walking, time spent walking at a moderate cadence (>100 steps/min), time spent standing, time spent sitting, number of sitting events (continuous periods of sitting), and the number of and of time spent sitting in prolonged events (>30 min). For each measure, a linear mixed effects model with dog ownership as a fixed effect, and a random effects structure of measurement point nested in participant nested in pair was used to assess the effect of dog ownership. Results: Owning a dog indicated a large, potentially health improving, average effect of 22 min additional time spent walking, 95%CI (12, 34), and 2760 additional steps per day, 95%CI (1667, 3991), with this additional walking undertaken at a moderate intensity cadence. Dog owners had significantly fewer sitting events. However, there were no significant differences between the groups for either the total time spent sitting, or the number or duration of prolonged sedentary events. Conclusions: The scale of the influence of dog ownership on PA found in this study, indicates that future research regarding PA in older adults should assess and report dog ownership and/or dog walking statu

    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M&gt;70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0&lt;e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
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