6,193 research outputs found
Effect on smoking quit rate of telling patients their lung age: the Step2quit randomised controlled trial
Objective To evaluate the impact of telling patients their estimated spirometric lung age as an incentive to quit smoking.Design Randomised controlled trial.Setting Five general practices in Hertfordshire, England.Participants 561 current smokers aged over 35.Intervention All participants were offered spirometric assessment of lung function. Participants in intervention group received their results in terms of "lung age" (the age of the average healthy individual who would perform similar to them on spirometry). Those in the control group received a raw figure for forced expiratory volume at one second (FEV1). Both groups were advised to quit and offered referral to local NHS smoking cessation services.Main outcome measures The primary outcome measure was verified cessation of smoking by salivary cotinine testing 12 months after recruitment. Secondary outcomes were reported changes in daily consumption of cigarettes and identification of new diagnoses of chronic obstructive lung disease.Results Follow-up was 89%. Independently verified quit rates at 12 months in the intervention and control groups, respectively, were 13.6% and 6.4% (difference 7.2%, P=0.005, 95% confidence interval 2.2% to 12.1%; number needed to treat 14). People with worse spirometric lung age were no more likely to have quit than those with normal lung age in either group. Cost per successful quitter was estimated at 280 pound ((euro) 365, $556). A new diagnosis of obstructive lung disease was made in 17% in the intervention group and 14% in the control group; a total of 16% (89/561) of participants.Conclusion Telling smokers their lung age significantly improves the likelihood of them quitting smoking, but the mechanism by which this intervention achieves its effect is unclear.Trial registration National Research Register N0096173751
Description of the Vetra Project and its Application for the VELO Detector
Vetra is the LHCb data reconstruction project which emulates the performance of the TELL1 readout board processing algorithms. This project is required for monitoring and commissioning the LHCb silicon detectors. A bit-perfect emulation of the TELL1 processing algorithms is performed. This project allows raw data (non-zero suppressed) to be processed to produce the standard zero suppressed cluster data, used by the LHCb reconstruction project Brunel. The Vetra framework is used by the VELO and ST detectors in LHCb. This note provides a general description of Vetra but concentrates on the VELO usage. Vetra is used to monitor the performance of the detector and the data acquisition board algorithms. The parameters that control the data acquisition boards are determined and optimised using Vetra. The project is used widely in the VELO and is used for testbeam and laboratory tests, including production testing for the modules
Velo Event Model
This note presents the Velo Event Model, it describes the classes and data flow used in the Velo software for all stages up to and including the clusters. The description is provided for the classes used for both the real data and the simulation. This description includes the data classes used during the standard running and simulation of the experiment, and all classes defined for calibration and commissioning
Application of near infrared reflectance spectroscopy in screening of fresh cassava (Manihot esculenta crantz) storage roots for provitamin A carotenoids
A developed Near Infrared Reflectance Spectroscopy (NIRS) calibration equation was used for determining provitamin A carotenoids contents of different trials of fresh yellow root cassava genotypes using a total of 50 cassava genotypes scanned twice by NIRS from 400 nm to 2498 nm. The NIRS calibration equations were used to predict the β-cryptoxanthin, 13-cis β-carotene, trans β-carotene, 9-cis β -carotene, total β-carotene and total carotenoid concentrations of the samples. The predicted values for total carotenoids (TC-pred) ranged from 3.93 μg g–1 to 10.51 μg g–1 with mean of 7.07 ± 2.55 μg g–1 for International Collaborative Trials (ICT), 7.97–11.03 μg g–1 fresh weight with mean of 9.40 ± 0.76 μg g–1 for yellow root trial 8 (Multi-location Uniform Yield Trial) and 6.38–10.44 μg g–1 with mean of 8.74 ± 1.07 μg g–1 for yellow root trial 9 (Multilocation Advanced Yield Trial). Total carotenoids results using reference spectrophotometric method (TC-spec) ranged from 2.57 μg g–1 to 9.97 μg g–1 with mean of 5.66 ± 2.99 μg g–1 for ICT, 6.55–8.74 μg g–1 with mean of 7.74 ± 0.64 μg g–1 for yellow root trial 8 and 4.22–11.00 μg g–1 with mean of 7.57 ± 1.54 μg g–1 for yellow root trail 9. There is significant (P ≤ 0.001) positive correlation (r = 0.55) between TC-pred by NIRS and TC-spec. Also, significant (P ≤ 0.001) positive correlation (r = 0.52) exist between trans β-carotene predicted by NIRS and high-performance liquid chromatography reference. The developed NIRS calibration equations could be used to predict total carotenoids and trans β-carotene content of yellow root cassava and serve as rapid and cost-effective screening method for large cassava sample sets
Truthful Multi-unit Procurements with Budgets
We study procurement games where each seller supplies multiple units of his
item, with a cost per unit known only to him. The buyer can purchase any number
of units from each seller, values different combinations of the items
differently, and has a budget for his total payment.
For a special class of procurement games, the {\em bounded knapsack} problem,
we show that no universally truthful budget-feasible mechanism can approximate
the optimal value of the buyer within , where is the total number of
units of all items available. We then construct a polynomial-time mechanism
that gives a -approximation for procurement games with {\em concave
additive valuations}, which include bounded knapsack as a special case. Our
mechanism is thus optimal up to a constant factor. Moreover, for the bounded
knapsack problem, given the well-known FPTAS, our results imply there is a
provable gap between the optimization domain and the mechanism design domain.
Finally, for procurement games with {\em sub-additive valuations}, we
construct a universally truthful budget-feasible mechanism that gives an
-approximation in polynomial time with a
demand oracle.Comment: To appear at WINE 201
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Adaptive Limited-Supply Online Auctions
We study a limited-supply online auction problem, in which an auctioneer has k goods to sell and bidders arrive and depart dynamically. We suppose that agent valuations are drawn independently from some unknown distribution and construct an adaptive auction that is nevertheless value- andtime-strategy proof. For the k=1 problem we have a strategyproof variant on the classic secretary problem. We present a 4-competitive (e-competitive) strategyproof online algorithm with respect to offline Vickrey for revenue (efficiency). We also show (in a model that slightly generalizes the assumption of independent valuations) that no mechanism can be better than 3/2-competitive (2-competitive) for revenue (efficiency). Our general approach considers a learning phase followed by an accepting phase, and is careful to handle incentive issues for agents that span the two phases. We extend to the k›1 case, by deriving strategyproof mechanisms which are constant-competitive for revenue and efficiency. Finally, we present some strategyproof competitive algorithms for the case in which adversary uses a distribution known to the mechanism.Engineering and Applied Science
A selected ion flow tube study of the ion-molecule reactions of monochloroethene, trichloroethene and tetrachloroethene
Data for the rate coefficients and product cations of the reactions of a large number of atomic and small molecular cations with monochloroethene, trichloroethene and tetrachloroethene in a selected ion flow tube at 298 K are reported. The recombination energy of the ions range from 6.27 eV (HO) through to 21.56 eV (Ne). Collisional rate coefficients are calculated by modified average dipole orientation theory and compared with experimental values. Thermochemistry and mass balance predict the most feasible neutral products. Together with previously reported results for the three isomers of dichloroethene (J. Phys. Chem. A., 2006, 110, 5760), the fragment ion branching ratios have been compared with those from threshold photoelectron photoion coincidence spectroscopy over the photon energy range 9-22 eV to determine the importance or otherwise of long-range charge transfer. For ions with recombination energy in excess of the ionisation energy of the chloroethene, charge transfer is energetically allowed. The similarity of the branching ratios from the two experiments suggest that long-range charge transfer is dominant. For ions with recombination energy less than the ionisation energy, charge transfer is not allowed; chemical reaction can only occur following formation of an ion-molecule complex, where steric effects are more significant. The products that are now formed and their percentage yield is a complex interplay between the number and position of the chlorine atoms with respect to the C=C bond, where inductive and conjugation effects can be important
The Effect of Training on Stride Duration in a Cohort of Two-Year-Old and Three-Year-Old Thoroughbred Racehorses
Objective gait monitoring is increasingly accessible to trainers. A more comprehensive understanding of ‘normal’ gait adaptations is required. Forty two-year-old thoroughbred racehorses were recruited when entering training and followed for 22 months. Gait analysis was performed by equipping each horse with an inertial measurement unit with inbuilt GPS (GPS-IMU) mounted on the dorsum. Horses were exercised as per their regular training regimen. Data were analysed using a linear mixed model. For two-year-old horses, there was a non-linear pattern of stride duration (SD) over time (p < 0.001) with SD decreasing initially and then ‘flattening off’ over time (linear and quadratic coefficients −0.29 ms/week and 0.006 ms/week2). Horses showed an increase in SD of 2.21 ms (p < 0.001) per 100 m galloped, and over time, SD decreased by 0.04 ms (p < 0.001) with each 100 m galloped per week. Three-year-old horses overall showed no change in SD over time (p = 0.52), but those that had a period of time off showed a decrease in SD of −0.59 ms per week (p = 0.02). They showed an increase in SD of 1.99 ms (p < 0.001) per 100 m galloped, and horses that had a period of time off showed an increase in stride duration of 1.05 ms per 100 m galloped (p = 0.01) compared to horses which did not have time off. Horses demonstrate an adaptation to high-speed exercise over time. SD decreases with training when other factors are controlled for in naïve horses
Threshold photoelectron photoion coincidence spectroscopy of trichloroethene and tetrachloroethene
The threshold photoelectron, the threshold photoelectron photoion coincidence and ion breakdown spectra of trichloroethene and tetrachloroethene have been recorded from 9 – 22 eV. Comparisons with the equivalent data for the three dichloroethene molecules and theoretical calculations highlight the nature of the orbitals involved during photoionisation in this energy range. The ground electronic state of CHCl (CCl) is bound, with excited valence states dissociating to CHCl (CCl) and CHCl (CCl). Appearance energies suggest that CHCl forms from CHCl by loss of two chlorine atoms, whereas CCl forms from CCl by loss of a Cl molecule. The translational kinetic energy release into CHCl (CCl) + Cl is determined as a function of energy. In both cases, the fraction of the available energy released into translational energy of the two products decreases as the photon energy increases
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