Two statistical analysis procedures applied to multivariate smoking cessation data

The field of smoking cessation research is plagued by inconsistent findings, caused in part by inadequate methodological or statistical analysis procedures. These problems are more serious in the case of smoking cessation treatments administered to groups of individuals;The effectiveness of two treatments is compared: an aversive smoking procedure followed by a maintenance phase (AM); and a nicotine fading procedure followed by the same maintenance phase (NM). Also, the benefits of being randomly selected to treatment (RS) versus self-selecting treatment (SS) are compared. Treatment was administered to groups of individuals, and groups differed in size from 2 to 17 participants. Information on subjects\u27 subsequent smoking status (abstinent or smoking) was collected at several follow-up times;Two statistical analysis procedures are applied to these data. Repeated measures analysis of variance (ANOVA) was carried out using as the unit of analysis the proportion of subjects abstinent at each of the several follow-up intervals. Survival analysis was carried out using individual subject\u27s time to return to smoking as the unit of analysis;Results using the ANOVA methods revealed no significant differences between the two treatments or the methods of selection to treatment. In contrast, a survival analysis procedure using a limited failure population Weibull model, while not demonstrating any difference in effectiveness between the AM and NM treatments, did reveal a significant difference between the methods of selection to treatment in favor of self-selection to treatment. However, other differences between the RS and SS methods make interpretation of this finding difficult;Several factors point to the greater appropriateness and statistical power of the survival analysis methodology over that of analysis of variance. However, there is a need to adapt survival analysis methodology to take account of the possible presence of group effects. Possibilities such as bootstrapping are discussed;In the psychological arena, both the oversmoking and nicotine fading treatment strategies appear equally effective. The indications that self-selection of treatment is beneficial are potentially important and invite further study. It also appears that future improvements in success rate will depend on improved relapse prevention

Statistical averaging in position determination by holography under turbulence conditions

An investigation of several, disparate phenomena is conducted with the aim of developing a novel surveying system capable of overcoming the limitations imposed by turbulence in modern surveying. This method incorporates standard holographic techniques and time domain statistical averaging of survey data. Some pertinent characteristics of atmospheric turbulence are reviewed, and the restrictions imposed on standard surveying practices by such turbulence are identified. A model for the turbulent medium is proposed on the basis of previous work and several theoretical results are summarized and extended. On this basis the technical characteristics of the proposed technique are developed and each step analyzed in detail and design procedures established. A specific surveying task is selected and the new method is applied. Experimental verification of each of the techniques employed in the new surveying method is presented. To this end techniques for the laboratory production of the desired condition and for the analysis of the method for recording survey data under turbulence are developed and their validity tested. Statistical analysis of the recorded survey data is presented to verify the accuracy of the results. As a second application of the holography principles and techniques described, a novel methodology is proposed, capable of overcoming inherent restrictions of the miniature techniques presently used by the motion picture industry. The existing use of miniature techniques is reviewed and the benefits of the holographic techniques are identified. The process by which the new method is implemented is described. The mathematics for determining the dimensions of the miniature objects and the locations of all the components utilized in making the hologram and reconstructing and magnifying its image are presented. Sources of distortion are also discussed and methods for avoiding them are indicated. Experimental verification is cited

Plane of nutrition affects the phylogenetic diversity and relative abundance of transcriptionally active methanogens in the bovine rumen

peer-reviewedMethane generated during enteric fermentation in ruminant livestock species is a major contributor to global anthropogenic greenhouse gas emissions. A period of moderate feed restriction followed by ad libitum access to feed is widely applied in cattle management to exploit the animal’s compensatory growth potential and reduce feed costs. In the present study, we utilised microbial RNA from rumen digesta samples to assess the phylogenetic diversity of transcriptionally active methanogens from feed-restricted and non-restricted animals. To determine the contribution of different rumen methanogens to methanogenesis during dietary restriction of cattle, we conducted high-throughput mcrA cDNA amplicon sequencing on an Illumina MiSeq and analysed both the abundance and phylogenetic origin of different mcrA cDNA sequences. When compared to their unrestricted contemporaries, in feed-restricted animals, the methanogenic activity, based on mcrA transcript abundance, of Methanobrevibacter gottschalkii clade increased while the methanogenic activity of the Methanobrevibacter ruminantium clade and members of the Methanomassiliicoccaceae family decreased. This study shows that the quantity of feed consumed can evoke large effects on the composition of methanogenically active species in the rumen of cattle. These data potentially have major implications for targeted CH4 mitigation approaches such as anti-methanogen vaccines and/or tailored dietary management

Characterizing the role of disparity information in alleviating visual crowding

The ability to identify a target is reduced by the presence of nearby objects, a phenomenon known as visual crowding. The extent to which crowding impairs our perception is generally governed by the degree of similarity between a target stimulus and its surrounding flankers. Here we investigated the influence of disparity differences between target and flankers on crowding. Orientation discrimination thresholds for a parafoveal target were first measured when the target and flankers were presented at the same depth to establish a flanker separation that induced a significant elevation in threshold for each individual. Flankers were subsequently fixed at this spatial separation while the disparity of the flankers relative to the target was altered. For all participants, thresholds showed a systematic decrease as flanker-target disparity increased. The resulting tuning function was asymmetric: Crowding was lower when the target was perceived to be in front of the flankers rather than behind. A series of control experiments confirmed that these effects were driven by disparity, as opposed to other factors such as flanker-target separation in three-dimensional (3-D) space or monocular positional offsets used to create disparity. When flankers were distributed over a range of crossed and uncrossed disparities, such that the mean was in the plane of the target, there was an equivalent or greater release of crowding compared to when all flankers were presented at the maximum disparity of that range. Overall, our results suggest that depth cues can reduce the effects of visual crowding, and that this reduction is unlikely to be caused by grouping of flankers or positional shifts in the monocular image

Fuel resource utilisation in landscapes of settlement

One little understood aspect of the settlement and colonisation of Iceland is fuel resource use. In this paper we identify fuel ash residues from temporally constrained middens at two contrasting settlement age sites in Mývatnssveit, northern Iceland, one high status, the other low status and ultimately abandoned. Fuel residues derived from experimental combustion of historically defined fuel resources are used to provide control for thin section micromorphology and complementary image analyses of fuel residue materials found in the midden deposits. The results suggest that fuel resources utilised at the time of settlement were for both low temperature and high temperature use, and included a mix of birch and willow wood, peat, mineral-based turf and cow dung. There are, however, marked variations in the mix of fuel resources utilised at the two sites. This is considered to reflect social regulation of fuel resources and socially driven changes to local and regional environments that may have contributed to the success or failure of early settlement sites in Iceland

Flow-enhanced detection of biological pathogens using piezoelectric microcantilever arrays

The piezoelectric microcantilever sensor (PEMS) is an all-electrical resonant oscillator biosensor system capable of in-situ and label-free detection. Immobilized receptors on the sensor surface enable real-time electrical measurement of the resonance frequency shift due to the binding of target antigens to the surface. With silane-based insulation methods and bifunctional linker antibody immobilization schemes, it is wellsuited for applications in sensitive, specific detection of biological pathogens with limits of detection on the order of relevant lethal infectious dosage concentrations. Initial PEMS implementation demonstrated biodetection of Bacillus anthracis (BA) spores at a concentration of just 36 total spores in 0.8 mL of liquid. While these results are exciting, concerns that cross reactivity between the antibody and closely related species of the target pathogens cast doubts on the usefulness of any antibody-based assays in terms of the specificity of pathogen detection.The goal of this dissertation is to develop the PEMS biosensor as a viable antibody-based assay for in-situ, label-free, water-borne pathogen detection with better limits of detection than current antibody-based methods as well as high sensitivity and specificity, by exploring array PEMS detection and specificity augmentation by engineered fluidics. In the detection of BA spores, controlled fluid flow experiments in an 8 mm wide flow channel at flow rates ranging from 0 to 14 mL/min led to a determination of optimal flow rates for discriminatory detection of BA spores among close cousins: B. cereus (BC), B. thuringiensis (BT) and B. subtilis (BS). It is shown that the detection signal of all such spores first increased with an increasing flow rate. The detection signals of BC, BT and BS eventually diminished with the increasing flow rate as the force of the flow overcame the interaction force of the BC, BT, and BS spores with the sensor surface. The optimal flow rate was determined to be 14 mL/min at which detection signals of BC, BT, and BS all fell to within the noise level of the sensor, while the detection BA was still nearly optimal. As a result, it was deduced that the interaction forces of BC, BT, and BS were about 100 pN.Design and implementation of array sensing systems enabled real-time simultaneous redundant biosensor assays and concurrent background determination by a reference PEMS. By virtue of this advance in PEMS technology, successful real-time detection of just 10 BA spores/mL was achieved and step-wise, single Cryptosporidium parvum (CP) oocyst detection at 0.1 oocysts/mL was accomplished with resonance frequency step-wise shifts of 290 Hz and signal to noise ratios greater than 5 per instance of oocyst detection. It was found that, in a 19 mm wide flow channel, optimal single oocyst detection efficiency was achieved at 2 mL/min, while optimal discrimination of CP from C. muris (CM) oocysts was achieved at 5 mL/min. At this flow rate the detection signal of CP was close to optimal with a signal to noise ratio of 5 per step-wise shift and that of CM was close to the noise level. The interaction forces of CP and CM oocysts with the biosensor surfaces were deduced to be 110 and 70 pN, respectively.Ph.D., Materials Science and Engineering -- Drexel University, 200

Information Labour and Shame in Farmer and Chevli’s Abortion Eve

his article conducts the first in-depth political-aesthetic analysis of Joyce Farmer and Lyn Chevli's Abortion Eve. In this article, we argue that Abortion Eve uses its visual form in a way that cuts between the contexts of later forms of graphic medicine and feminist comix, and in so doing contributed to a political culture of feminist information sharing, through a self-published visual medium

Balloon Atrial Septostomy as Initial Therapy in Pediatric Pulmonary Hypertension

Balloon atrial septostomy is a palliative procedure currently used to bridge medically refractory pulmonary hypertension patients to lung transplantation. In the current report, we present balloon atrial septostomy as an initial therapy for high-risk pediatric pulmonary hypertension patients at our institution. Nineteen patients with median age of 4.3 years (range 0.1-14.3 years) underwent balloon atrial septostomy during initial admission for pulmonary hypertension. There were no procedural complications or deaths within 24 h of balloon atrial septostomy. Patients were followed for a median of 2.6 years (interquartile range 1.0-4.8 years). Three (16%) patients died, 3 (16%) underwent lung transplantation, and 1 (5%) underwent reverse Potts shunt. Transplant-free survival at 30 days, 1 year, and 3 years was 84%, 76%, and 67% respectively. This single-center experience suggests early-BAS in addition to pharmacotherapy is safe and warrants consideration in high-risk pediatric pulmonary hypertension patients

Information Labour and Shame in Farmer and Chevli’s Abortion Eve

This article conducts the first in-depth political-aesthetic analysis of Joyce Farmer and Lyn Chevli’s Abortion Eve. In this article we argue that Abortion Eve uses its visual form in a way that cuts between the contexts of later forms of graphic medicine and feminist comix, and in so doing contributed to a political culture of feminist information sharing, through a self-published visual medium

A comparison of CT-body composition measurements in non-cancer and cancer patients from a single UK centre

Objectives: Establish the prevalence of low skeletal muscle index and density in our population, by comparing age and sex matched cohorts of patients with and without cancer, using standardized methodology for CT-Body composition (CT-BC). Methods: A retrospective analysis of prospectively collected data. Patients admitted to our institution between 17th March 2020 - 1st May 2020, with confirmed coronavirus disease and imaging suitable for CT-BC (n=52), were age and sex matched with patients undergoing resection for colorectal cancer (n=52). Results: 104 patients were included in the final analysis. 43% (n=45) were male, 77% (n=80) were aged 65 years or older, 50% (n=50) were overweight (BMI ≥25) and 53% (n=55) were systemically inflamed (mGPS ≥1). The prevalence of a low SMI (56% vs. 65%) and low SMD (83% vs. 67%) was similar between cohorts. A low SMI and SMD were both associated with age (p<0.05 and p<0.01, respectively) on univariate analysis. On multivariate analysis, a low SMD was independently associated with age (OR 2.38 (1.34-4.22), p=0.003) and mGPS (OR 2.10 (1.20-3.68), p=0.01). Conclusions: In conclusion, the prevalence of a low SMI and low SMD was similar in non-cancer and cancer cohorts in our institution