Decrease in resting heart rate measured using smartphone apps to verify abstinence from smoking: an exploratory study

INTRODUCTION: Verifying self-reports of smoking abstinence is challenging in studies that involve remote data collection. Resting heart rate (HR) decreases during smoking abstinence. This study assessed whether a decrease in resting HR measured using freely available smartphone apps could potentially be used to verify smoking abstinence. METHODS: This study involved a repeated measures experimental design, with data collection in natural setting. Participants were 18 adult, daily smokers. They recorded resting HR in beats per minute (bpm) using freely available smartphone apps during five time points (two in the morning and three post-noon) on each of three days. The outcome measure was the mean of the post-noon HR recordings. The experimental condition for each of the three days (counterbalanced order) was: 1) smoking as usual, 2) not smoking without nicotine replacement therapy (NRT), or 3) not smoking but using NRT. Abstinence was verified using expired-air carbon monoxide (CO) concentration. RESULTS: Compared with the smoking as usual condition, mean HR was 13.4 bpm lower (95%CI=5.4-21.4,p=0.001) in the not smoking without NRT condition and 10.4 bpm lower (95%CI=3.1-17.8, p=0.004) in the not smoking with NRT condition. There was no statistically significant difference in HR between the two not smoking conditions (p=0.39). Abstinence during not smoking days without and with NRT was CO-verified in 18/18 and in 16/18 cases, respectively. CONCLUSIONS: Self-recording of resting heart rate in natural setting using smartphone apps shows a reliable decrease in response to smoking abstinence and may provide a basis for remote verification in smoking cessation studies. IMPLICATIONS: Remote verification of self-reported abstinence in smoking cessation studies remains challenging. Smoking abstinence has been shown to decrease resting heart rate under laboratory conditions. This study demonstrated that self-recording using freely available smartphone apps shows reliable decreases in resting heart rate during smoking abstinence and may provide a basis for inexpensive remote verification of smoking abstinence

Rapid Neutrophil Response Controls Fast-Replicating Intracellular Bacteria but Not Slow-Replicating Mycobacterium tuberculosis

Being one of the first cells to invade the site of infection, neutrophils play an important role in the control of various bacterial and viral infections. In the present work, the contribution of neutrophils to the control of infection with different intracellular bacteria was investigated. Mice were treated with the neutrophil-depleting monoclonal antibody RB6-8C5, and the time course of infection in treated and untreated mice was compared by using intracellular bacterial species and strains varying in virulence and replication rate. The results indicate that neutrophils are crucial for the control of fast-replicating intracellular bacteria, whereas early neutrophil effector mechanisms are dispensable for the control of the slow-replicating Mycobacterium tuberculosi

Structured smoking cessation training for health professionals on cardiology wards: a prospective study.

Background: Smoking is a major cardiovascular risk factor, and smoking cessation is imperative for patients hospitalised with a cardiovascular event. This study aimed to evaluate a systems-based approach to helping hospitalised smokers quit and to identify implementation barriers. Design: Prospective intervention study followed by qualitative analysis of staff interviews Methods: The prospective intervention study assessed the effects of implementing standard operating procedures (SOPs) for the provision of counselling and pharmacotherapy to smokers admitted to cardiology wards on counselling frequency. In addition, a qualitative analysis of staff interviews was undertaken to examine determinants of physician and nurse behaviour; this sought to understand barriers in terms of motivation, capability and/or opportunity. Results: A total of 150 smoking patients were included in the study (75 before and 75 after SOP implementation). Before the implementation of SOPs, the proportion of patients reporting to have received cessation counselling from physicians and nurses was 6.7% and 1.3%, respectively. Following SOP implementation, these proportions increased to 38.7% (p < 0.001) and 2.7% (p = 0.56), respectively. Qualitative analysis revealed that lack of motivation, e.g. role incongruence, appeared to be a major barrier. Conclusions: Introduction of a set of standard operating procedures for smoking cessation advice was effective with physicians but not nurses. Analysis of barriers to implementation highlighted lack of motivation rather than capability or opportunity as a major factor that would need to be addressed

Turbulent Friction in Rough Pipes and the Energy Spectrum of the Phenomenological Theory

The classical experiments on turbulent friction in rough pipes were performed by J. Nikuradse in the 1930's. Seventy years later, they continue to defy theory. Here we model Nikuradse's experiments using the phenomenological theory of Kolmog\'orov, a theory that is widely thought to be applicable only to highly idealized flows. Our results include both the empirical scalings of Blasius and Strickler, and are otherwise in minute qualitative agreement with the experiments; they suggest that the phenomenological theory may be relevant to other flows of practical interest; and they unveil the existence of close ties between two milestones of experimental and theoretical turbulence.Comment: Accepted for publication in PRL; 4 pages, 4 figures; revised versio

Retention time and dispersion associated with submerged aquatic canopies

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Water Resources Research 43 (2007): W04422, doi:10.1029/2006WR005362.The shear layer at the top of a submerged canopy generates coherent vortices that control exchange between the canopy and the overflowing water. Unlike free shear layers, the vortices in a canopy shear layer do not grow continuously downstream but reach and maintain a finite scale determined by a balance between shear production and canopy dissipation. This balance defines the length scale of vortex penetration into the canopy, δ e , and the region of rapid exchange between the canopy and overflow. Deeper within the canopy, transport is constrained by smaller turbulence scales. A two-box canopy model is proposed on the basis of the length scale δ e . Using diffusivity and exchange rates defined in previous studies, the model predicts the timescale required to flush the canopy through vertical exchange over a range of canopy density and height. The predicted canopy retention times, which range from minutes to an hour, are consistent with canopy retention inferred from tracer observations in the field and comparable to retention times for some hyporheic regions. The timescale for vertical exchange, along with the in-canopy velocity, determines the minimum canopy length for which vertical exchange dominates water renewal. Shorter canopies renew interior water through longitudinal advection. Finally, canopy water retention influences longitudinal dispersion through a transient storage process. When vertical exchange controls canopy retention, the transient storage dispersion increases with canopy height. When longitudinal advection controls water renewal, dispersion increases with canopy patch length.This material is based upon work supported by the National Science Foundation under grant EAR0309188

Relationship between aerodynamic roughness length and bulk sedge leaf area index in a mixed-species boreal mire complex

Leaf area index (LAI) is an important parameter in natural ecosystems, representing the seasonal development of vegetation and photosynthetic potential. However, direct measurement techniques require labor-intensive field campaigns that are usually limited in time, while remote sensing approaches often do not yield reliable estimates. Here we propose that the bulk LAI of sedges (LAI(s)) can be estimated alternatively from a micrometeorological parameter, the aerodynamic roughness length for momentum (z(0)). z(0) can be readily calculated from high-response turbulence and other meteorological data, typically measured continuously and routinely available at ecosystem research sites. The regressions of LAI versus z(0) were obtained using the data from two Finnish natural sites representative of boreal fen and bog ecosystems. LAI(s) was found to be well correlated with z(0) and sedge canopy height. Superior method performance was demonstrated in the fen ecosystem where the sedges make a bigger contribution to overall surface roughness than in bogs.Peer reviewe

A clock network for geodesy and fundamental science

Leveraging the unrivaled performance of optical clocks in applications in fundamental physics beyond the standard model, in geo-sciences, and in astronomy requires comparing the frequency of distant optical clocks truthfully. Meeting this requirement, we report on the first comparison and agreement of fully independent optical clocks separated by 700 km being only limited by the uncertainties of the clocks themselves. This is achieved by a phase-coherent optical frequency transfer via a 1415 km long telecom fiber link that enables substantially better precision than classical means of frequency transfer. The fractional precision in comparing the optical clocks of three parts in $10^{17}$ was reached after only 1000 s averaging time, which is already 10 times better and more than four orders of magnitude faster than with any other existing frequency transfer method. The capability of performing high resolution international clock comparisons paves the way for a redefinition of the unit of time and an all-optical dissemination of the SI-second.Comment: 14 pages, 3 figures, 1 tabl

Quitting Without Reporting Having Tried: Findings From a National Survey

Background: It is assumed that smokers rarely quit without 'attempting' to do so but the assumption does not appear to have been adequately tested. This study assessed the prevalence of reporting having stopped without reporting a quit attempt and the reasons given for this discrepancy. Methods: Data were collected from ex-smokers who said they had quit within the last 12 months during nationally representative household surveys conducted monthly between 2006-12. Results: Of the 1,892 ex-smokers who said that they had quit within the last 12 months, 13.9% (95%CI = 12.4%-15.5%) reported having made no serious quit attempts in that period. In a sub-group of 24 smokers who were asked why they had reported stopping without also reporting an attempt, nine cited inconsistency over timing; three reported stopping without attempting to do so; four did not consider it an 'attempt' because they had succeeded; and six had not ruled out the occasional cigarette in the future. Conclusions: A substantial minority of people who report having stopped in the past year may fail to report a corresponding quit attempt. However, quitting smoking without considering that one has tried appears to be rare. Instead, the most common reason for the discrepancy is inconsistent reporting of the timing of quit attempts. Copyright © The Author(s), published by Cambridge University Press on behalf of Australian Academic Press Pty Ltd 2014

Association between exposure to environmental tobacco smoke and biomarkers of oxidative stress among patients hospitalised with acute myocardial infarction

Objective To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction.&lt;p&gt;&lt;/p&gt; Design An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction.&lt;p&gt;&lt;/p&gt; Setting Nine acute hospitals in Scotland.&lt;p&gt;&lt;/p&gt; Participants Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine ≥3.0 ng/mL) were compared with 60 never smokers who had not (admission serum cotinine ≤0.1 ng/mL).&lt;p&gt;&lt;/p&gt; Intervention None.&lt;p&gt;&lt;/p&gt; Main outcome measures Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA) and oxidised low-density lipoprotein (ox-LDL)) were measured on admission blood samples and adjusted for potential confounders.&lt;p&gt;&lt;/p&gt; Results After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031) and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001) but not ox-LDL (beta coefficient 2.14, 95% CI −8.94, 13.21, p = 0.703).&lt;p&gt;&lt;/p&gt; Conclusions Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.&lt;p&gt;&lt;/p&gt

Finite Temperature DMRG Investigation of the Spin-Peierls Transition in CuGeO3_3

We present a numerical study of thermodynamical properties of dimerized frustrated Heisenberg chains down to extremely low temperatures with applications to CuGeO$_3$. A variant of the finite temperature density matrix renormalization group (DMRG) allows the study of the dimerized phase previously unaccessible to ab initio calculations. We investigate static dimerized systems as well as the instability of the quantum chain towards lattice dimerization. The crossover from a quadratic response in the free energy to the distortion field at finite temperature to nonanalytic behavior at zero temperature is studied quantitatively. Various physical quantities are derived and compared with experimental data for CuGeO$_3$ such as magnetic dimerization, critical temperature, susceptibility and entropy.Comment: LaTeX, 5 pages, 5 eps figures include