Penetration depth of low-coherence enhanced backscattered light in sub-diffusion regime

The mechanisms of photon propagation in random media in the diffusive multiple scattering regime have been previously studied using diffusion approximation. However, similar understanding in the low-order (sub-diffusion) scattering regime is not complete due to difficulties in tracking photons that undergo very few scatterings events. Recent developments in low-coherence enhanced backscattering (LEBS) overcome these difficulties and enable probing photons that travel very short distances and undergo only a few scattering events. In LEBS, enhanced backscattering is observed under illumination with spatial coherence length L_sc less than the scattering mean free path l_s. In order to understand the mechanisms of photon propagation in LEBS in the subdiffusion regime, it is imperative to develop analytical and numerical models that describe the statistical properties of photon trajectories. Here we derive the probability distribution of penetration depth of LEBS photons and report Monte Carlo numerical simulations to support our analytical results. Our results demonstrate that, surprisingly, the transport of photons that undergo low-order scattering events has only weak dependence on the optical properties of the medium (l_s and anisotropy factor g) and strong dependence on the spatial coherence length of illumination, L_sc, relative to those in the diffusion regime. More importantly, these low order scattering photons typically penetrate less than l_s into the medium due to low spatial coherence length of illumination and their penetration depth is proportional to the one-third power of the coherence volume (i.e. [l_s \pi L_sc^2 ]^1/3).Comment: 32 pages(including 7 figures), modified version to appear in Phys. Rev.

Instantonic approach to triple well potential

By using a usual instanton method we obtain the energy splitting due to quantum tunneling through the triple well barrier. It is shown that the term related to the midpoint of the energy splitting in propagator is quite different from that of double well case, in that it is proportional to the algebraic average of the frequencies of the left and central wells.Comment: Revtex, 11 pages, Included one eps figur

Feasibility and Preliminary Efficacy of a Physical Activity Counseling Intervention Using Fitbit in People With Knee Osteoarthritis: The TRACK-OA Study Protocol

Background Physical activity (PA) reduces pain and improves functioning in people with knee osteoarthritis (OA), but few people with the condition meet recommended PA guidelines. Successful intervention strategies to increase PA include goal setting, action planning, self-monitoring, and follow-up feedback from a healthcare professional. Recently developed consumer wearable activity trackers allow users to set activity goals, self-monitor daily goal-progress, and provide feedback on goal attainment. It is hypothesized that a multi-component physiotherapist-led intervention that includes a short (40-min) education module, guided goal-setting and action planning, the use of a wristband activity tracker, and weekly follow-up phone calls will lead to increased PA outcomes. Methods/design Thirty-six participants will be recruited from the community for a two-group pilot randomized controlled trial with a stepped-wedge design using an intention-to-treat analysis. Computer-generated block randomization will be performed using varying block sizes and a 1:1 allocation ratio. The 4-week intervention will be delivered immediately (immediate-intervention group) or after a 5-week delay (delayed-intervention group). Outcome measures of pain and disability (Knee Injury and OA Outcome Score), disease self-management ability (Partners in Health Scale), and objective bouted moderate-to-vigorous PA and sedentary time (BodyMedia SenseWear Mini Armband) will be collected at baseline (week 0) and two follow-ups (weeks 5 and 10), for a total study duration of 11 weeks. Feasibility data relating to process, resource, management, and scientific elements of the trial will be collected. Outcome measure and feasibility data will be summarized, and an estimate of intervention efficacy will be obtained by regression model with planned comparisons. The trial began recruiting in February 2015. To date, 34 subjects have been recruited. Discussion This study will evaluate the feasibility and preliminary efficacy of a novel intervention to promote PA in people living with knee OA. The results will provide valuable information to inform a larger randomized trial to assess intervention effectiveness

Sleep Duration, Sleep Quality, and the Development of Nonalcoholic Fatty Liver Disease:A Cohort Study

INTRODUCTION: The longitudinal relationship between sleep duration, sleep quality, and the risk of nonalcoholic fatty liver disease (NAFLD) is unknown. We aimed to examine the association between sleep duration, sleep quality, and NAFLD development.METHODS: Using the Pittsburgh Sleep Quality Index, sleep duration and quality were evaluated for 143,306 NAFLD-free Korean adults with a mean age of 36.6 years, who were followed for an average of 4.0 years. Hepatic steatosis (HS) was assessed using ultrasonography and liver fibrosis by the fibrosis-4 index (FIB-4) or the NAFLD fibrosis score. Flexible parametric proportional hazard models were used to determine the hazard ratios (HRs) and 95% confidence intervals.RESULTS: There were 27,817 subjects with incident HS, of whom 1,471 had incident HS plus intermediate/high FIB-4. Multivariable-adjusted HRs (95% confidence intervals) for incident HS comparing sleep durations of ≤5, 6, 8, and ≥ 9 hours with 7 hours were 1.19 (1.14-1.23), 1.07 (1.04-1.10), 0.98 (0.94-1.02), and 0.95 (0.87-1.03), respectively. The corresponding HRs for incident HS plus intermediate/high FIB-4 were 1.30 (1.11-1.54), 1.14 (1.01-1.29), 1.11 (0.93-1.33), and 1.08 (0.71-1.63). The association between sleep duration and HS plus intermediate/high FIB-4 was inverse in individuals with good sleep quality but tended to be U-shaped in those with poor sleep quality. The results were similar if FIB-4 was replaced by the NAFLD fibrosis score.DISCUSSION: In young adults, short sleep duration was independently associated with an increased risk of incident NAFLD with or without intermediate/high fibrosis score, suggesting a role for inadequate sleep quantity in NAFLD risk and severity.</p

Decrease in sleep duration and poor sleep quality over time is associated with an increased risk of incident non-alcoholic fatty liver disease

The impact of changes in sleep duration and sleep quality over time on the risk of nonalcoholic fatty liver disease (NAFLD) is not known. We investigated whether changes in sleep duration and in sleep quality between baseline and follow-up are associated with the risk of developing incident NAFLD. The cohort study included 86,530 Korean adults without NAFLD and with a low fibrosis score at baseline. The median follow-up was 3.6 years. Sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index. Hepatic steatosis (HS) and liver fibrosis were assessed using ultrasonography and the fibrosis-4 index (FIB-4). Cox proportional hazard models were used to determine hazard ratios (HRs) and 95% confidence intervals (Cis). A total of 12,127 subjects with incident HS and 559 with incident HS plus intermediate/high FIB-4 was identified. Comparing the decrease in sleep duration of &gt;1 h, with stable sleep duration, the multivariate-adjusted HR (95% CIs) for incident HS was 1.24 (1.15–1.35). The corresponding HRs for incident HS plus intermediate/high FIB-4 was 1.58 (1.10–2.29). Comparing persistently poor sleep quality with persistently good sleep quality, the multivariate-adjusted HR for incident HS was 1.13 (95% CI, 1.05–1.20). A decrease in sleep duration or poor sleep quality over time was associated with an increased risk of incident NAFLD, underscoring an important potential role for good sleep in preventing NAFLD risk.</p

Analysis of differentially expressed long non-coding RNAs in LPS-induced human HMC3 microglial cells

Abstract Background Long non-coding RNAs (lncRNAs) are emerging as key modulators of inflammatory gene expression, but their roles in neuroinflammation are poorly understood. Here, we identified the inflammation-related lncRNAs and correlated mRNAs of the lipopolysaccharide (LPS)-treated human microglial cell line HMC3. We explored their potential roles and interactions using bioinformatics tools such as gene ontology (GO), kyoto encyclopedia of genes and genomes (KEGG), and weighted gene co-expression network analysis (WGCNA). Results We identified 5 differentially expressed (DE) lncRNAs, 4 of which (AC083837.1, IRF1-AS1, LINC02605, and MIR3142HG) are novel for microglia. The DElncRNAs with their correlated DEmRNAs (99 total) fell into two network modules that both were enriched with inflammation-related RNAs. However, treatment with the anti-inflammatory agent JQ1, an inhibitor of the bromodomain and extra-terminal (BET) protein BRD4, neutralized the LPS effect in only one module, showing little or even enhancing effect on the other. Conclusions These results provide insight into, and a resource for studying, the regulation of microglia-mediated neuroinflammation and its potential therapy by small-molecule BET inhibitors