Associations amongst sedentary and active behaviours, energy expenditure, body fat and appetite dysregulation

Purpose The objective was to investigate whether measures of appetite dysregulation were associated with sedentary time, physical activity, energy expenditure or fat mass. Cross-sectional and prospective studies indicate sedentary behaviour is associated with obesity. Most studies use questionnaire based self-report measures of sedentary time. In contrast, this study employed an innovative device that measured motion, galvanic skin response, skin temperature and heat flux. Methods Thirty demographically diverse participants (8men, 22women; age: 49.1±14.2years; BMI: 26.8±4.9kg/m2) took part in this cross-sectional study. Measures of body composition (Bodpod), health markers, cardiovascular fitness and resting metabolic rate (indirect calorimetry), and appetite dysregulation (Three-Factor Eating Questionnaire and Binge Eating Scale) were taken as well as 6-7days measurement of free-living physical activity (light 1.5-3METs; moderate 3-6METs; and vigorous >6METs) and sedentary behaviour (<1.5METs) with the SenseWear Armband (BodyMedia). Active energy expenditure was calculated by subtracting measured resting metabolic rate from total measured energy expenditure calculated by the Armband. Results A minimum of 6 full days (>22h/day) were analysed for each participant (7days: n=14; 6days: n=16). Average wear-time of the SenseWear Armband was 98±1.3% of total possible wear-time. Sedentary behaviour was positively correlated with multiple indices of adiposity including fat mass (r=.39,p3 METs) was negatively associated with fat mass (r=-.69,p<.001), body fat percentage (r=-.70,p<.001) and waist circumference (r=-.65,p<.001). Physical activity and sedentary behaviour were not associated with indices of appetite dysregulation. TFEQ Disinhibition and Binge Eating were positively associated with BMI (r=.75,p<.001;r=.57,p=.001), fat mass (r=.70,p<.001;r=.58,p=.001), body fat percentage (r=.63,p<.001;r=.45,p<.05) and waist circumference (r=.69,p<.001;r=.58,p=.001) but not with lean mass (r=.24(ns);r=.13(ns)). Active energy expenditure was negatively associated with sedentary time (r=.-43,p<.05) and positively associated with moderate-to-vigorous physical activity (r=.45, p<.05). Conclusion Sedentary time was associated with low energy expenditure and higher adiposity whereas MVPA was associated with higher energy expenditure and lower adiposity. Higher adiposity (but not sedentary time, physical activity or low energy expenditure) was associated with Disinhibition and Binge Eating (appetite dysregulation)

Effect of Drugs on Rabbit Retina

The adverse effects of drugs in the eye are not easily detected, and the underlying pathogenesis not fully understood. The effects of four different kinds of drugs have been investigated in the rabbit eye, using electroretinography, ocular examination and histochemical methods. Rifabutin is a broad spectrum antibiotic with known ocular adverse effects (corneal opacities, uveitis and vascular retinopathy) in the human eye. In the rabbit eye rifabutin causes lens discoloration and it significantly reduces both total rod-cone function and isolated cone function, but it does not affect retinal morphology. Ranibizumab, bevacizumab, and pegaptanib are inhibitors of the cytokine vascular endothelial growth factor. Pegaptanib and ranibizumab are approved for injection into the vitreous. Bevacizumab is a cancer drug injected off-label intravitreally. In rabbit rod-mediated function was found depressed 8 weeks after a single injection of all three VEGF inhibitors. Rod bipolar cells were affected in the groups injected with pegaptanib and ranibizumab, but not with bevacizumab. Triamcinolone acetonide is a corticosteroid with depot properties, used for intramuscular and intraarticular injections. In Europe, triamcinolone is commercially available only in combination with the preservative benzyl alcohol, and is not approved for intraocular use. Triamcinolone has been and is extensively used off-label for injections into the vitreous body. Intravitreal injection of triamcinolone and benzyl alcohol, separately and in combination, affected both retinal function and histology. Adalimumab, a monoclonal antibody against the pro-inflammatory cytokine tumor necrosis factor α is approved for subcutaneous injection in autoimmune diseases. The level of TNFα is raised in ocular inflammatory conditions. No functional disturbances were found on examination with ffERG after injection into the vitreous body of rabbits. Retinal histology was found to be intact. These studies have shown that drugs may affect both retinal function and histology in the rabbit eye, and that retinal electrophysiology combined with histochemistry can detect the retinal level and the cell type involved in these processes, or exclude retinal damage by the drug. This knowledge should alert ophthalmologists to perform extensive investigations in patients on medication who present with unaccountable visual symptoms

Relationship Quality from the Perception of Romantic Partners of Narcissists

Research has recently taken a closer look at how narcissists behave in romantic relationships. The goal of this study was to see how relationship quality is perceived by their partners. Participants were asked a) to rate their partners on their levels of narcissism and their impressions about how their partners seek to get their way, b) about their relationship quality, and c) about their own levels of narcissism. Results revealed that perceiving partners as scoring higher on narcissistic rivalry and vulnerable narcissism was generally associated with lower relationship quality, while perceiving the partner as scoring higher on communal narcissism and narcissistic admiration was associated with higher relationship quality. When participants reported that their partners were more narcissistic (with regard to communal narcissism, narcissistic rivalry, and vulnerable narcissism), they reported their partners used less positive means to get their way (such as using manipulation, supplication, bullying, and disengagement). These strategies, in turn, predicted lower quality relationships. These findings help shed light on why relationships with narcissists might not last.No embargoAcademic Major: Psycholog

Characterization of the HIV-1 RNA associated proteome identifies Matrin 3 as a nuclear cofactor of Rev function

<p>Abstract</p> <p>Background</p> <p>Central to the fully competent replication cycle of the human immunodeficiency virus type 1 (HIV-1) is the nuclear export of unspliced and partially spliced RNAs mediated by the Rev posttranscriptional activator and the Rev response element (RRE).</p> <p>Results</p> <p>Here, we introduce a novel method to explore the proteome associated with the nuclear HIV-1 RNAs. At the core of the method is the generation of cell lines harboring an integrated provirus carrying RNA binding sites for the MS2 bacteriophage protein. Flag-tagged MS2 is then used for affinity purification of the viral RNA. By this approach we found that the viral RNA is associated with the host nuclear matrix component MATR3 (Matrin 3) and that its modulation affected Rev activity. Knockdown of MATR3 suppressed Rev/RRE function in the export of unspliced HIV-1 RNAs. However, MATR3 was able to associate with Rev only through the presence of RRE-containing viral RNA.</p> <p>Conclusions</p> <p>In this work, we exploited a novel proteomic method to identify MATR3 as a cellular cofactor of Rev activity. MATR3 binds viral RNA and is required for the Rev/RRE mediated nuclear export of unspliced HIV-1 RNAs.</p

Barrow and Gilt Vocalizations during a Human Approach Test

The objective of this study was to investigate differences between barrow and gilt vocalizations during a fear test. Twenty barrows and 20 gilts were tested over two consecutive weeks between 1300 and 1900 hours using a human approach test (HAT). Throughout the test, vocalizations were recorded. Gilts expressed a greater number of low calls compared to barrows; however, barrows expressed a greater number of high calls compared to gilts. Further research should be done to better understand vocalization differences between barrows and gilts during a HAT

Association of Vocalizations and Swine Behavior during a Human Approach Test

The objective of this study was to determine if the duration and total number of pig vocalizations when divided into low and high call categories was related to pig behaviors during a fear test. Twenty barrows and 20 gilts were tested over two consecutive weeks between 1300 and 1900 hours using a human approach test (HAT). Throughout the test, vocalizations and behavior were recorded. These results suggest that while high calls are typically the primary measure of stress vocalizations, low calls are also meaningful measures during the stressor of HAT

Structured, aerobic exercise reduces fat mass and is partially compensated through energy intake but not energy expenditure in women

Background Exercise-induced weight loss is often less than expected and highly variable in men and women. Behavioural compensation for the exercise-induced energy deficit could be through energy intake (EI), non-exercise physical activity (NEPA) or sedentary behaviour (SB). We investigated this issue in women. Methods Twenty-four overweight [body mass index (BMI) M = 27.9 kg/m2, SD = 2.7] women [age M = 33.1 years, SD = 11.7] completed 12-weeks of supervised exercise (5×500kcal per week) in a non-randomised pre-post intervention study. Body mass (BM), waist circumference (WC), body composition, resting metabolic rate (RMR), total daily EI, individual meals, appetite sensations and appetite-related peptides were measured at baseline (week 0) and post-intervention (week 12). Free-living physical activity (PA) and SB were measured (SenseWear) at baseline, week 1 and 10 of the exercise intervention, and at post-intervention (week 13). Results Following the 12-week exercise intervention BM [p = .04], BMI [p = .035], WC [p  .05]. There was no compensatory reduction in NEPA [p > .05] and no increase in SB, rather there was a decrease in SB during the exercise intervention [p = .03]. Conclusions Twelve-weeks of supervised aerobic exercise resulted in a significant reduction in FM and an increase in FFM. Exercise increased hunger and EI which only partially compensated for the increase in energy expenditure. There was no evidence for a compensatory reduction in NEPA or an increase in SB. Dietary intervention, as an adjunct to exercise, may offset the compensatory increase in EI and result in a greater reduction in BM

Is the presence of sedentary behaviour or the absence of physical activity responsible for fat mass and appetite dysregulation? Preliminary results from the DAPHNE project.

Introduction: The objective was to investigate whether measures of appetite dysregulation were associated with sedentary time, physical activity, energy expenditure or fat mass. Several studies indicate sedentary behaviour is associated with obesity but most use questionnaire-based self-report measures of sedentary time. The present study employed an innovative validated device for the objective measurement of sedentary and active behaviour. Methods: Thirty participants took part in this cross-sectional study. Measures of body composition, health markers, cardiovascular fitness and resting metabolic rate, and appetite dysregulation were taken as well as 7days measurement of free-living physical activity and sedentary behaviour with the SenseWear Armband. Active energy expenditure was calculated by subtracting measured resting metabolic rate from total measured energy expenditure from the Armband. Results: Sedentary behaviour was positively correlated with multiple indices of adiposity. These associations disappeared when controlling for moderate-to-vigorous physical activity (MVPA). MVPA was negatively associated with fat mass. Physical activity and sedentary behaviour were not associated with indices of appetite dysregulation. TFEQ Disinhibition and Binge Eating were positively associated with indices of adiposity but not with lean mass. Active energy expenditure was negatively associated with sedentary time and positively associated with moderate-to-vigorous physical activity. Conclusion: The results suggest that the lack of MVPA may be more important than total sedentary time for the accumulation of body fat. Higher adiposity (but not sedentary time, physical activity or low energy expenditure) was associated with Disinhibition and Binge Eating (appetite dysregulation)

Investigating the impact of sedentariness on appetite control: A multilevel platform linking energy intake and energy expenditure.

We have investigated appetite control within an energy balance framework and examined the impact of variations in physical activity on the appetite response for a number of years. These studies (and other research) have demonstrated reciprocal relationships between energy intake and energy expenditure as Edholm (1955) predicted more than 50years ago. Changing the level of physical activity influences the control of appetite, and adjusting food consumption influences activity energy expenditure. These investigations have been extended to examine the impact of sedentariness on appetite control recognising that under conditions of low energy expenditure the homeostatic control of food intake is weakened. These studies are incorporated within DAPHNE (data-as-a-service-platform-for-healthy-lifestyle-and-preventive-medicine) an EU framework 7 project under the ICT programme. This project is designed to establish quantitative relationships between sedentary behaviours and markers of poor health. These data will be generated using advanced sensors and the information will be made available through cloud-computing technology to permit the development of healthcare programmes based on behaviour change. The body of experimental work will use the Leeds multi-level platform which monitors daily profiles of sedentary and active behaviour, with the measurement of body composition, satiety physiology (gut peptides) and homeostatic and hedonic processes of appetite control. This ongoing programme of research (together with the EU Framework 7 SATIN project) provides opportunities for industry and academia to examine the impact of foods on appetite control under varying levels of sedentariness and activity. Using Sensewear Armband (Bodymedia) and tri-axial accelerometers (ActigraphGT3X) we will examine how large variations in daily activity (sitting to very vigorous) are related to the homeostatic control of satiety

Associations Among Free-Living Sedentary and Active Behaviours, Adiposity and Appetite Control Within an Energy Balance Framework

Background It was proposed over 60 years ago that “the differences between the intakes of food must originate in differences in the expenditure of energy” (Edholm et al., 1955). It was also proposed that a ‘U’ shaped function described the relationship between physical activity (PA) energy expenditure (EE) and dietary intake (Mayer et al., 1956); this relationship also involved body mass. These relationships served as the basis for the studies conducted for this thesis. The main objective was to examine the associations among free-living sedentary and active behaviours, adiposity and appetite control. The investigation was conducted within an energy balance framework. The main focus of the thesis was to extend understanding of the interaction between PA, sedentary behaviour (SB), adiposity and appetite. Methods The methodology was based on measurements of body composition together with anthropometric, physiological, behavioural and psychological variables and involved a combination of cross-sectional and medium-term (12-weeks) intervention studies. The thesis used state-of-the-art methodology for measuring free-living activity and aimed to detect a measure of SB based on both posture and activity intensity. Results Study 1 - SB was positively associated with adiposity and moderate-to-vigorous physical activity (MVPA) was negatively associated with adiposity. Study 2 - A procedure was developed to integrate data on two dimensions of free-living SB (posture and activity intensity) using two validated activity monitors. Study 3 - Posture alone (as a marker of SB) is not a good indicator of the tendency to accumulate fat mass (FM). Study 4 - Total EE and the metabolic contributors to total EE (fat-free mass (FFM) and resting metabolic rate (RMR)) were associated with subjective appetite sensations and EI, and provisionally can be regarded as drivers of appetite. Study 5 - The 12-week exercise intervention resulted in a significant (compensatory) increase in EI, however, there was no change in non-exercise physical activity (NEPA). Study 6 - Diet induced weight loss (mainly FM loss) did not lead to a compensatory reduction in PA or increase in SB. Conclusions These studies have extended the understanding of the associations among PA, SB, adiposity and appetite control. The outcomes of the studies have contributed to a theoretical framework for understanding the interactions between physiological and behavioural variables that contribute to energy balance and body mass (adiposity) regulation under realistic conditions. It could be deduced that a combination of increased EE (through exercise) and reduced EI are likely to produce greater weight loss and more favourable changes in body composition than either exercise or diet alone