DIFFERENTIATING BETWEEN LOW LEVEL ACTIVITIES IN SEDENTARY OCCUPATIONS UTILIZING FITBITS

Objective: Fitbits are popular devices used to track personal activity throughout the day. The potential usage of these devices in tracking sedentary activities in research studies rely on the validity and accuracy of the devices. The objectives of this study are to investigate if changes in daily activity is associated with changes in duration of standing time using a sit-to-stand workstation. Also to establish if an accelerometer may be used to detect differences between sitting and standing sedentary positions. Methods: Sixteen participants wore Fitbit accelerometers throughout the workday and were emailed surveys on a weekly basis to report their sitting and standing percentages. Spearman correlation was used to compare mean daily step counts and mean standing percentages. A subsample of seven participants wore Fitbit and completed log sheets detailing precise periods of sitting and standing while at work. The number of steps registered during sitting and standing periods was compared for each individual using a paired t-test. Results: No statistically significant correlation was found between a participant’s mean standing percentage and mean daily step count (p-value = 0.563). Paired t-test analysis of participants found no statistically significant difference between the total number of steps registered while sitting and the total number of steps registered while standing (p-value = 0.034). Conclusions: No observable association between daily activity and duration of standing time was found. The number of steps measured using a Fitbit accelerometer may not be a useful method to assess sit-to-stand workstation usage. Limitations with the study included possible selection bias, incomplete self-reporting surveys, low sample sizes and short study durations. Future studies accounting for these limitations may prove to yield more statistically significant results regarding the use of Fitbits in assessing sedentary activity

An investigation into the velocity-dependence of the coefficient of friction between concrete and maraging steel

This work investigates the velocity-dependent coefficient of friction between concrete and 300 Maraging steel over short displacements. A modified torsional Hopkinson bar is utilized for rotating thin-walled steel rings in contact with a concrete disk under static precompression. Rotational velocity is varied between tests to determine the velocity dependence of the friction coefficient. Normal force is varied between certain tests to determine the pressure dependence of the friction coefficient between the concrete and steel. Three different types of concrete are tested to deduce any composition effect on the friction coefficient. Dry and greased conditions’ impact on the friction coefficient are also evaluated. Lastly, the displacement dependence (fade) is considered for the concrete with regards to the steel. Discussion of the usefulness of this data in modeling and experimentation of impact between concrete and steel is disclosed

Effects of a Carbon-Plated Racing Shoe on Running Economy at Slower Running Speeds

Advancements in running shoe technology, such as the inclusion of a carbon-fiber plate along with new, thicker midsole foams, have been shown to improve running economy. Running economy can be defined as the oxygen consumption (VO2) or caloric expenditure at a fixed running speed. Specifically in the Nike Vaporfly line of racing shoes, running economy improvements have been shown in the 2.7-4.2% range at running speeds of 14-18 km·hr-1. These previously tested speeds are relevant for runners completing the marathon distance in 3 hours and faster. However, it is unclear if the same running economy benefits are conferred at slower running paces. PURPOSE: Determine the effects of the Nike Vaporfly Next% 2 (NVF2) on running economy at 10 and 12 km·hr-1. METHODS: NVF2 was compared to a mass-matched, control (CTRL) shoe, the Asics Hyper Speed. Sixteen runners (8 male: 29 ± 15 years, 68.8 ± 10.9 kg, 17.2 ± 4.7 % body fat, 5-km best: 19.1 ± 2.6 min; 8 female: 38 ± 7 years, 58.5 ± 7.4 kg, 23.6 ± 3.0 % body fat, 5-km best: 20.3 ± 2.2 min) completed 4 x 5-minute trials at 10 km‧hr-1, followed by another series of 4 x 5-minute trials at 12 km‧hr-1 on the same day. There was a 5-minute seated rest between trials. Each shoe was tested twice at each speed in a mirrored sequence with the order counterbalanced across subjects. Metabolic and running mechanics data were collected and averaged. Data were analyzed by a two-way (shoe x speed) repeated measures ANOVA. Significant interactions were followed up with paired sample t-tests. RESULTS: There was a significant shoe x speed interaction for VO2 (p = 0.021). At 12 km‧hr-1, VO2 (ml·kg-1·min-1) was lower (-1.4 ± 1.1%; p \u3c 0.001) for NVF2 (35.8 ± 1.7) relative to CTRL (36.4 ± 1.7). This was greater in magnitude than the differences observed at 10 km‧hr-1 (-0.9 ± 1.8%; p = 0.065) between NVF2 (29.4 ± 1.9) and CTRL (29.6 ± 1.9). Mechanics data showed main effects for shoe condition (p \u3c 0.05) with a decreased cadence (~1.1 step·min-1) and increased vertical oscillation (~0.17 cm) in NVF2 relative to CTRL. CONCLUSION: From these data, it appears that the NVF2 still provides benefits to running economy at 12 km‧hr-1 (~3.5-hour marathon pace), however these benefits may be smaller in magnitude (1.4%) compared to previous research (2.7-4.2%) at faster speeds of 14-18 km‧hr-1. These benefits may be reduced even further (0.9%) at 10 km‧hr-1 (~4.2-hour marathon pace)

Evaluation of Recovery from High Intensity Functional Training

As the implementation of frequent high intensity functional training (HIFT) participation continues to grow among a variety of individuals, recovery between bouts of training is important to consider to prevent overtraining. PURPOSE: The purpose of this study was to determine effective measures of recovery following an acute HIFT training session. METHODS: Participants (22.0 ± 2.8 years old, 173.6 ± 30.5 lbs., and 26.2 ± 8.24% body fat) consisted of 5 females and 3 males (n = 8), who were recreationally trained (30+ minutes moderate-vigorous exercise 4+ times/week) and had previous experience with HIFT training. Participants conducted a 20-minute, as many rounds as possible (AMRAP) exercise session. Data was collected prior to the exercise session and recovery was monitored for 30-minutes immediately post- and at 24-hours post-exercise. Before exercise and 24-hours post-exercise heart rate (HR), heart rate variability (HRV), vertical jump (VJ), upper body power (UBP), perceptual measures (PM) of recovery/exertion, and Altman Self-Rating Mania Scale (ASMR) were recorded. During exercise, heart rate, rating of perceived exertion, and the number of rounds completed were recorded. Data were evaluated using a Paired Samples T-test and Wilcoxon Signed-Ranks Test with significance set at p £ 0.05 for all analysis. RESULTS: Paired samples T-tests did not indicate significant differences between pre- and post-exercise in HR, HRV, and UBP but did denote significant differences between pre- and post-exercise in VJ (21.4 ± 7.7 vs 19.9 ± 7.1 inches). Wilcoxon-Signed Ranks Tests did not demonstrate significant differences in PM or ASMR. CONCLUSION: Possible limitations of this research include the small sample size. Based on our data VJ and UBP were the only measures that demonstrated pre- to post-exercise differences and as a result these measurements appear to be parameters that are sensitive to detecting fatigue induced from an acute bout of HIFT

Virtual Canine Lameness: the development of a training tool

Lameness is commonly encountered in veterinary practice, however precise visual lameness detection requires experience. This skill is challenging to teach: exposure of students to many patients is needed to learn the necessary perceptual skills; however patients might not be readily available. Video recordings of patients can be useful, but depend on the quality of recording and variety of cases available. They are limited to two dimensional views which don’t fully replicate a real-life three dimensional examination. Following on the success of an equine lameness training tool (www.lamenesstrainer.com) developed at the Royal Veterinary College; a 3D virtual canine lameness tool is being developed to teach students to reliably recognize canine lameness. We collected 3D motion capture data from 10 non-lame Labrador retrievers at walk and trot on a treadmill. Data were captured using eight Oqus7 cameras (Qualisys, Sweden). The movement of these dogs was recorded based on 32 reflective markers positioned over key anatomical locations. Marker positions for twenty steady strides for one dog were averaged to drive the skeleton movement of a matching 3D dog model in Autodesk MotionBuilder. The final clips were rendered to show a realistic-looking shaded wireframe of the dog model at normal walk and trot. Varying types and degrees of lameness were then introduced to this animation based on previous kinematic studies. Next stages of work will involve the inclusion of this model in a tool to enable it to be used for veterinary education; once validated it will be released as an Open Educational Resource

Prevalence of and Barriers to Dual-Contraceptive Methods Use among Married Men and Women Living with HIV in India

Objective. To describe the prevalence and correlates of dual-contraceptive methods use (condoms and an effective pregnancy prevention method) and barriers to their use among married persons living with HIV (PLHIV) in India. Methods. We conducted a quantitative survey (93 men, 97 women), 25 in-depth interviews, seven focus groups, and five key informant interviews. Results. Prevalence of dual- contraceptive method use increased from 5% before HIV diagnosis to 23% after diagnosis (P < 0.001). Condoms were the most common contraceptive method, with prevalence increasing from 13% before diagnosis to 92% after diagnosis (P < 0.001). Barriers to using noncondom contraceptives were lack of discussion about noncondom contraceptives by health care providers, lack of acceptability of noncondom contraceptives among PLHIV, and lack of involvement of husbands in family planning counseling. Conclusion. There is a need for interventions, including training of health care providers, to increase dual-contraceptive methods use among married PLHIV

Altered brain energetics induces mitochondrial fission arrest in Alzheimer's Disease.

Altered brain metabolism is associated with progression of Alzheimer's Disease (AD). Mitochondria respond to bioenergetic changes by continuous fission and fusion. To account for three dimensional architecture of the brain tissue and organelles, we applied 3-dimensional electron microscopy (3D EM) reconstruction to visualize mitochondrial structure in the brain tissue from patients and mouse models of AD. We identified a previously unknown mitochondrial fission arrest phenotype that results in elongated interconnected organelles, "mitochondria-on-a-string" (MOAS). Our data suggest that MOAS formation may occur at the final stages of fission process and was not associated with altered translocation of activated dynamin related protein 1 (Drp1) to mitochondria but with reduced GTPase activity. Since MOAS formation was also observed in the brain tissue of wild-type mice in response to hypoxia or during chronological aging, fission arrest may represent fundamental compensatory adaptation to bioenergetic stress providing protection against mitophagy that may preserve residual mitochondrial function. The discovery of novel mitochondrial phenotype that occurs in the brain tissue in response to energetic stress accurately detected only using 3D EM reconstruction argues for a major role of mitochondrial dynamics in regulating neuronal survival

Randomized clinical trial of a brief and extensive dyadic intervention for advanced cancer patients and their family caregivers

Background Few intervention programs assist patients and their family caregivers to manage advanced cancer and maintain their quality of life (QOL). This study examined (i) whether patient–caregiver dyads (i.e., pairs) randomly assigned to a brief or extensive dyadic intervention (the FOCUS Program) had better outcomes than dyads randomly assigned to usual care and (ii) whether patients' risk for distress and other factors moderated the effect of the brief or extensive program on outcomes. Methods Advanced cancer patients and their caregivers ( N  = 484 dyads) were stratified by patients' baseline risk for distress (high versus low), cancer type (lung, colorectal, breast, or prostate), and research site and then randomly assigned to a brief (three‐session) or extensive (six‐session) intervention or control. The interventions offered dyads information and support. Intermediary outcomes were appraisals (i.e., appraisal of illness/caregiving, uncertainty, and hopelessness) and resources (i.e., coping, interpersonal relationships, and self‐efficacy). The primary outcome was QOL. Data were collected prior to intervention and post‐intervention (3 and 6 months from baseline). The final sample was 302 dyads. Repeated measures MANCOVA was used to evaluate outcomes. Results Significant group by time interactions showed that there was an improvement in dyads' coping ( p  < 0.05), self‐efficacy ( p  < 0.05), and social QOL ( p  < 0.01) and in caregivers' emotional QOL ( p  < 0.05). Effects varied by intervention dose. Most effects were found at 3 months only. Risk for distress accounted for very few moderation effects. Conclusions Both brief and extensive programs had positive outcomes for patient–caregiver dyads, but few sustained effects. Patient–caregiver dyads benefit when viewed as the ‘unit of care’. Copyright © 2012 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96760/1/pon3036.pd