Properties and Analysis of Thermally Aged Poly(ethylene oxide)

Recent studies have been performed into the use of polyethylene oxide (PEO) as a model system for observing the fundamental effects of adding micro and nano sized fillers to create polymeric composite systems. Many factors contribute to the successful creation of such a composite system, including dispersion of the filler and treatment of the material during creation. For example, while producing thin films of the materials for testing, high temperatures were used for short periods of time in open air to press the samples into small discs. It is well known that prolonged high temperature exposure can alter the chemistry and structure of polymeric materials and that small variations in the original chemistry, such as longer molecular weights or introduction of fillers, can reduce or possibly accelerate this 'ageing' effect. From these previous investigations many property changes were observed during addition of filler or variation of molecular weight, therefore to accurately attribute these changes to a cause the thermal ageing of the material should be observed. This investigation looks at the same 3 molecular weight PEO systems as those used in the previous investigations and analyses them for their vulnerability to thermal ageing. One thermally aged sample is then taken and tested alongside an unaged sample to observe the effects that the process has on the properties. This includes rheology in solution, differential scanning calorimetry (DSC), AC electrical breakdown, dielectric spectroscopy and Fourier transform infra-red (FTIR). By observing the property changes of aged samples it is possible to better understand the thermal ageing process occurring and possibly a way to reduce the effect, along with considering the effect with regard to the behaviour of the previously tested composite samples

Exercise Preferences Among Young Adults: Do Men and Women Want Different Things?

Background Young adult men are difficult to recruit and retain in lifestyle interventions. This may be in part to gender differences in exercise goals observed in men, but little is known about exercise preferences for young adults, specifically. The purpose of this study is to compare the exercise preferences of young men and women to inform future interventions in this area. We hypothesize that men will prefer strength training at higher rates than women, and that women will prefer supervised guidance at higher rates than men. Methods The sample included 288 young adults aged 18-25 (mean age=21.85, SD=2.2). Majority were women and within a normal BMI range (M=25.91, SD=5.3). An anonymous online survey study was completed. Participants were asked their preferred type of exercise (moderate intensity cardio, strength training, intense strength training, or a combination of cardio and strength training), and if they preferred to exercise at a clinic-based facility with supervised guidance or to exercise alone with guidance.Chi-square tests were conducted to determine if there are gender differences in preferences for exercise type and mode of delivery, accounting for BMI. Results Over two-third of young adults preferred a combination of moderate intensity cardio and strength training. Women and men differed significantly in their exercise preferences (p=\u3c .001). Less than 1% of women preferred intense strength training compared to the 15.3% of men. Women (17.4%) preferred moderate intensity cardio at higher rates than men (12.2%). However, when examining outcomes by BMI category, these results were only significantly different among individuals within a normal BMI (p=.000). Majority of young adults (67.7%) prefer exercising with their own with guidance from a program. Men and women did not differ in their preference to exercise with guidance or in a clinic-based program with supervision (p=.115). Conclusion Findings suggest that young adults overall prefer a combination of strength training and cardio, conducted on their own with guidance from a program. However, young men were more likely to prefer intense strength training; this was particularly true among men in a normal BMI range. These findings may be used to inform the tailoring of recruitment messaging and lifestyle interventions targeting this high-risk population.https://scholarscompass.vcu.edu/gradposters/1033/thumbnail.jp

Weight Loss and Self-Monitoring among Young Men in a Technology-Driven Weight Loss Intervention

Background Young men with obesity have double the mortality risk compared to young men with a healthy weight, but are notoriously challenging to recruit for behavioral weight loss (BWL) programs. Emerging evidence suggests that young men might prefer self-guided or low touch interventions, but limited data are available as to their effectiveness. To inform future efforts, we conducted a secondary analysis of young men’s performance in a technology-driven BWL trial developed specifically for young adults. Objectives were to: 1) examine young men’s enrollment rates; and 2) compare young men and women’s weight loss outcomes and self-regulation behaviors. Methods Data were drawn from an ongoing randomized controlled trial targeting young adults (18-25 years, body mass index 25-45 kg/m2) for weight loss. Participants (N=184, 60% racial / ethnic minority, BMI=33.2) were recruited using a multi-method approach and randomized to one of three arms, all of which received a 6-month technology mediated intervention with content adapted specifically for young adults. For the purposes of the present analysis, outcomes of interest included weight change at 3 months (objectively assessed in-clinic) and engagement with self-regulation behaviors (captured via Bluetooth scales and self-monitoring app). Treatment arm was included as a covariate in all outcome analyses. Descriptive statistics were computed to capture enrollment rates. GLM was used to compare men and women on percent weight change at 3-months, days of self-weighing, and days of dietary self-monitoring. Results Young men represented 17% of enrolled participants. At 3-months, men manifested greater weight losses compared to women (-4.8±5.1% vs. -2.5±4.1%, p=.008). Over the course of the 3-months, engagement with self-regulation behaviors was similar for men and women; men had a similar number of days of self-weighing (46.77±24.6 vs. 47.42±24.0, p=.88) and a lower number of days for tracking diet (36.87±24.3 vs. 43.42±22.6, p=.15) relative to women. Conclusion While enrollment was low among young men in this technology-driven BWL program, those men who enrolled lost double the weight compared to women—even though engagement with self-monitoring behaviors was similar or lower. These results suggest that a low touch and primarily self-guided weight loss program may be sufficient to produce clinically meaningful weight loss among young men. Findings are discussed in terms of implications for future work.https://scholarscompass.vcu.edu/gradposters/1041/thumbnail.jp

Examining gender differences in young men and women’s goals for a technology-driven weight loss intervention

Background Emerging adults (EA) are at high risk for weight gain and obesity yet are underrepresented in behavioral weight loss (BWL) programs and fare worse than their older counterparts when they join these programs. Further, even within BWL programs adapted specifically for this population, young men are particularly challenging to recruit, representing less than 20% of samples in recent trials. One hypothesis for the poor recruitment of men is that men’s goals for a weight loss program are not described in recruitment messages for these studies. Understanding whether men and women’s personal goals for participating in a weight loss program could be a key way to tailor recruitment messaging. As such, the objective of this study is to compare young men and women’s personal goals for a BWL program. Methods Participants (N=382; 21.9+1.2 years; 83% female; BMI=33.5+4.9 kg/m2) were recruited for a technology-driven weight loss intervention adapted for this age group. At baseline, participants ranked their top 3 personal goals from a list of 15 areas in which they wanted to see change during the program. The most commonly reported areas (n=8) were coded as yes or no if the goal was ranked as one of their top 3. Chi-square tests were conducted to compare men and women on the most commonly reported goals for the program; using Bonferroni correction to adjust for multiple comparisons (p\u3c.006). Results Overall, the most commonly reported areas for wanting to change in the program were: weight (62.7%), physical fitness (43.7%), body fat percentage (25.7%), body shape (25.1%), energy level (24.1%), clothing size (19.6%), confidence (18.8%), and self-esteem (18.0%). Weight was the most commonly ranked as a top goal (43.5%), followed by physical fitness (11.3%) and body fat percentage (8.9%). No significant differences were found between men and women for personal goals. Conclusion Emerging adults have a desire to lose weight and body fat, as well as improve physical fitness when it comes to personal goals for a weight loss program. While there were no gender differences in goals for a weight loss program, this could be due to enrollment of a treatment seeking sample. Coupled with differential enrollment of young men, it is possible the results may not be representative of non-treatment seeking young men. More research is needed to understand potential gender differences in goals for a weight loss program to improve recruitment messaging targeting young men.https://scholarscompass.vcu.edu/gradposters/1118/thumbnail.jp

A systematic review of weight-related communication trainings for physicians: What do we know and how can we inform future development of training programs?

It is reported that physicians lack training to address weight-related concerns with patients. To overcome this, training programs have been implemented in medical settings to prepare physicians to have conversations with patients. However, it is unclear the degree of consistency among existing training programs and factors associated with better outcomes. The objective of this study was to systematically review the existing literature in this area to determine differences in content, outcomes, and implementation of existing studies that test weight-related communication training programs for physicians. A systematic literature review of online databases including PubMed, PsycINFO, and Proquest was conducted with the assistance of a librarian. Search terms included: health communication, training, physician training, weight, and obesity. Studies were selected based on the following inclusion criteria: physicians are post-graduate medical doctors; trainings encompassed weight-related communication; and outcomes were tied to physician uptake of skills, knowledge, and self-efficacy, or patient-related outcomes. Two coders reviewed studies using detailed inclusion criteria. Disagreements were resolved by consensus among authors. Half of studies assessed outcomes in both patients and physicians. Trainings including motivational interviewing (MI) assessing patient outcomes found increases in patient knowledge, satisfaction, motivation, and weight loss, respectively. Whereas, non-MI trainings assessing patient outcomes found an increase in patient weight loss, confidence and motivation, or no changes in patient outcomes. This review was the first to examine programs aimed to teach physicians to communicate with patients about weight. Future studies should examine the effect of physician communication on BMI.https://scholarscompass.vcu.edu/gradposters/1025/thumbnail.jp

Enumeration of bigrassmannian permutations below a permutation in Bruhat order

In theory of Coxeter groups, bigrassmannian elements are well known as elements which have precisely one left descent and precisely one right descent. In this article, we prove formulas on enumeration of bigrassmannian permutations weakly below a permutation in Bruhat order in the symmetric groups. For the proof, we use equivalent characterizations of bigrassmannian permutations by Lascoux-Schutzenberger and Reading.Comment: 7 pages

Habitat use by smooth snakes on lowland heath managed using 'conservation grazing'

Heathland in the UK, and parts of mainland Europe, is being managed increasingly by landowners and statutory conservation bodies e.g., Natural England, using cattle grazing which is often referred to as 'conservation grazing' in an attempt to justify its use in the absence of any detailed prior research into its actual benefits for wildlife species whose individual habitat requirements are likely to vary. Over four years, between 2010 and 2013, cattle were excluded from six hectares of lowland heath that had been subject to annual summer cattle grazing between May 1997 and autumn 2009 and in which reptile numbers had been monitored annually since 1997. Changes in smooth snake (Coronella austriaca) numbers were recorded annually in the ungrazed area and in a four hectare area of heathland adjacent to it that continued to be grazed. The number of individual smooth snakes, and the total number of smooth snake captures, were significantly higher in the ungrazed heath than the grazed heath and were associated with increased habitat structure, resulting principally from tall heathers and grasses. The results of the study suggest that the use of cattle grazing as a management tool on lowland heath is detrimental to smooth snake populations and that their recovery, following the cessation of grazing, may take many years

Scanning optical pyrometer for measuring temperatures in hollow cathodes

Life-limiting processes in hollow cathodes are determined largely by the temperature of the electron emitter. To support cathode life assessment, a noncontact temperature measurement technique which employs a stepper motor-driven fiber optic probe was developed. The probe is driven inside the hollow cathode and collects light radiated by the hot interior surface of the emitter. Ratio pyrometry is used to determine the axial temperature profile. Thermocouples on the orifice plate provide measurements of the external temperature during cathode operation and are used to calibrate the pyrometer system in situ with a small oven enclosing the externally heated cathode. The diagnostic method and initial measurements of the temperature distribution in a hollow cathode are discussed

Evidence of micro-continent entrainment during crustal accretion

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