246 research outputs found
Cyber Buddy is Better than No Buddy: A Test of the Köhler Motivation Effect in Exergames.
Objective: Although exergames are popular, few people take advantage of the potential of group dynamics to
motivate play (and achieve associated health bene?ts). One motivation gain phenomenon has shown promise for
motivating greater effort in partnered exergames: The Koehler effect (working at a task with a more capable partner
where one’s performance is indispensable to the group). This article examines whether a Koehler effect can be
demonstrated in an exergame by exercising with a moderately superior humanoid, software-generated partner.
Materials and Methods: Male and female (n = 120; mean age, 19.41 years) college students completed a series
of plank exercises using ‘‘CyBuddy Exercise,’’ a program developed speci?cally for this study. In a lab in an
academic building, participants completed the exercises individually and, after a rest, were randomly assigned
to complete the same exercises again, but with a ‘‘live’’ human partner (HP) presented virtually, a nearlyhuman-like,
humanoid partner (NHP), a hardly human-like, software-generated partner (HHP), or a no-partner
control condition (IC), with equal numbers in each group (i.e., n = 30). Exercise persistence, perceived exertion,
self-ef?cacy beliefs, enjoyment, and intentions to exercise were recorded and analyzed.
Results: A 4X2 analysis of variance on the (Block 2 – Block 1) difference scores showed that a signi?cant
Koehler motivation gain was observed in all partner conditions (compared with IC), but persistence was signi?cantly
greater with HPs than with either NHP or HHP humanoid partners (P < 0.05). By the conclusion of the
study, there were no signi?cant differences among the partnered conditions in perceived exertion, self-ef?cacy,
enjoyment, or future intentions to exercise.
Conclusions: These results suggest that a software-generated partner can elicit the Koehler motivation gain in
exergames, but not as strongly as a partner who is thought to be human
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Controllability Modulates the Anticipatory Response in the Human Ventromedial Prefrontal Cortex
Research has consistently shown that control is critical to psychological functioning, with perceived lack of control considered to play a crucial role in the manifestation of symptoms in psychiatric disorders. In a model of behavioral control based on non-human animal work, Maier et al. (2006) posited that the presence of control activates areas of the ventromedial prefrontal cortex (vmPFC), which in turn inhibit the normative stress response in the dorsal raphe nucleus and amygdala. To test Maier’s model in humans, we investigated the effects of control over potent aversive stimuli by presenting video clips of snakes to 21 snake phobics who were otherwise healthy with no comorbid psychopathologies. Based on prior research documenting that disrupted neural processing during the anticipation of adverse events can be influenced by different forms of cognitive processing such as perceptions of control, analyses focused on the anticipatory activity preceding the videos. We found that phobics exhibited greater vmPFC activity during the anticipation of snake videos when they had control over whether the videos were presented as compared to when they had no control over the presentation of the videos. In addition, observed functional connectivity between the vmPFC and the amygdala is consistent with previous work documenting vmPFC inhibition of the amygdala. Our results provide evidence to support the extension of Maier’s model of behavioral control to include anticipatory function in humans
Dimerization of ABCG2 Analysed by Bimolecular Fluorescence Complementation
ABCG2 is one of three human ATP binding cassette transporters that are functionally capable of exporting a diverse range of substrates from cells. The physiological consequence of ABCG2 multidrug transport activity in leukaemia, and some solid tumours is the acquisition of cancer multidrug resistance. ABCG2 has a primary structure that infers that a minimal functional transporting unit would be a homodimer. Here we investigated the ability of a bimolecular fluorescence complementation approach to examine ABCG2 dimers, and to probe the role of individual amino acid substitutions in dimer formation. ABCG2 was tagged with fragments of venus fluorescent protein (vYFP), and this tagging did not perturb trafficking or function. Co-expression of two proteins bearing N-terminal and C-terminal fragments of YFP resulted in their association and detection of dimerization by fluorescence microscopy and flow cytometry. Point mutations in ABCG2 which may affect dimer formation were examined for alterations in the magnitude of fluorescence complementation signal. Bimolecular fluorescence complementation (BiFC) demonstrated specific ABCG2 dimer formation, but no changes in dimer formation, resulting from single amino acid substitutions, were detected by BiFC analysis
Differences in satiety effects of alginate- and whey protein-based foods
Satiety is important in regulating food intake and has important public health significance in the control of obesity. Food containing protein and non-starch polysaccharides provides a satiety effect through various mechanisms but a comparison of the satiety effect on each has not previously been investigated. This study compared the satiety effect or reduction of hunger after consumption of (i) a whey proteinbased drink versus an alginate-based drink of the same viscosity where only the protein content differed, (ii) two alginate-based drinks differing in alginate type and viscosity, and (iii) a whey protein-based drink versus an alginate-based drink differing in protein content and viscosity. Fasted subjects assessed the effect of a drink on hunger that was one of three variants: a low viscosity whey protein drink (LVHP); a high viscosity low protein alginate-based drink (HVLP); or a low viscosity low protein alginate-based drink (LVLP) over the 240 min postprandial period using a Visual Analogue Scale (VAS). When protein differed and viscosity was the same, results showed subjects felt significantly less hungry after consuming the LVHP drink compared to the LVLP drink, so protein reduced hunger. Subjects reported reduced hunger from the HVLP drink compared to the LVLP drink where viscosity of drinks differed, suggesting viscosity and/or gelation reduced hunger. Subjects reported reduced hunger from the HVLP drink compared to LVHP drink where both protein and viscosity differed, suggesting that viscosity reduced hunger more than the protein effect. Results suggest the physical characteristics such as viscosity and/or gel strength and protein content reduce hunger. Further studies should investigate which of these parameters is more important
Calcium Intake in Elderly Australian Women Is Inadequate
The role of calcium in the prevention of bone loss in later life has been well established but little data exist on the adequacy of calcium intakes in elderly Australian women. The aim of this study was to compare the dietary intake including calcium of elderly Australian women with the Australian dietary recommendation, and to investigate the prevalence of calcium supplement use in this population. Community-dwelling women aged 70–80 years were randomly recruited using the Electoral Roll for a 2-year protein intervention study in Western Australia. Dietary intake was assessed at baseline by a 3-day weighed food record and analysed for energy, calcium and other nutrients. A total of 218 women were included in the analysis. Mean energy intake was 7,140 ± 1,518 kJ/day and protein provided 19 ± 4% of energy. Mean dietary calcium intake was 852 ± 298 mg/day, which is below Australian recommendations. Less than one quarter of women reported taking calcium supplements and only 3% reported taking vitamin D supplements. Calcium supplements by average provided calcium 122 ± 427 mg/day and when this was taken into account, total calcium intake increased to 955 ± 504 mg/day, which remained 13% lower than the Estimated Average Requirement (EAR, 1,100 mg/day) for women of this age group. The women taking calcium supplements had a higher calcium intake (1501 ± 573 mg) compared with the women on diet alone (813 ± 347 mg). The results of this study indicate that the majority of elderly women were not meeting their calcium requirements from diet alone. In order to achieve the recommended dietary calcium intake, better strategies for promoting increased calcium, from both diet and calcium supplements appears to be needed
Long-term effects of a protein-enriched diet on blood pressure in older women
Short-term randomised, controlled trials have found that dietary protein relative to carbohydrate can reduce blood pressure. Our objective was to investigate the effects on blood pressure of an increase in protein intake from whey over 2 years in women aged over 70 years. From the general population, 219 women aged between 70 and 80 years were recruited to a 2-year randomised, double-blind, placebo-controlled parallel-design trial: 181 women completed the trial to the end of year 2. Participants were randomly assigned to consume a daily whey protein-based beverage (protein) or an energy-matched low-protein high-carbohydrate beverage (control). Blood pressure measurements were performed at baseline, year 1 and year 2. For protein relative to control, the estimated mean net differences in protein and carbohydrate intakes were 18 (95 % CI 13, 23) and − 22 (95 % CI − 9, − 35) g/d at year 1, and 22 (95 % CI 17, 28) and − 18 (95 % CI − 6, − 31) g/d at year 2. Intention-to-treat analysis found no overall differences between groups in blood pressure (P>0.5). Net differences in systolic and diastolic blood pressure were – 2.3 (95 % CI – 5.3, 0.7) and – 1.5 (95 % CI – 3.6, 0.6) mmHg at year 1, and 1.6 (95 % CI – 1.5, 4.7) and 0.3 (95 % CI – 1.9, 2.4) mmHg at year 2. Similar differences in systolic and diastolic blood pressure at years 1 and 2 were observed with per-protocol analysis. Therefore, the present study did not provide evidence that a higher whey protein intake in older women can have prolonged effects on blood pressure
Dietary inflammatory index and the aging kidney in older women: a 10‑year prospective cohort study
Purpose: Chronic inflammation plays a role in the pathogenesis of age-related renal disease and the diet can moderate systemic inflammation. The primary objective of this study was to examine the associations between a dietary inflammatory index ( DII®) score and renal function, the trajectory of renal function decline, and renal disease-related hospitalizations and/or mortality over 10 years. Methods: The study was conducted in 1422 Western Australian women without prevalent chronic kidney disease and aged ≥ 70 years. Baseline dietary data, obtained from a validated food frequency questionnaire, were used to calculate a DII score for each individual. Results: In this cohort, the mean [range] DII score was 0.19 [− 6.14 to 6.39]. A higher DII score was associated with poorer renal function at baseline and a greater renal function decline over 10 years; after multivariable adjustments, a one unit higher DII score was associated with a 0.55 mL/min/1.73 m2 lower eGFR at baseline (p = 0.01) and a 0.06 mL/min/1.73 m2 greater annual decline in eGFR over 10 years (p = 0.05). Restricted cubic splines provide evidence of a non-linear association between baseline DII score and risk of a renal disease-related event. Compared to participants in the lowest quintile, those in the highest quintile of DII score were at a higher risk of experiencing a renal disease-related event (adjusted HR 2.06, 95% CI 0.97, 4.37). Conclusion: Recommending an increased consumption of foods with a higher anti-inflammatory potential could form part of a multifaceted approach to reduce the risk of renal disease through diet and lifestyle changes
Physical activity in relation to urban environments in 14 cities worldwide: a cross-sectional study
Background
Physical inactivity is a global pandemic responsible for over 5 million deaths annually through its effects on multiple non-communicable diseases. We aimed to document how objectively measured attributes of the urban environment are related to objectively measured physical activity, in an international sample of adults.
Methods
We based our analyses on the International Physical activity and Environment Network (IPEN) adult study, which was a coordinated, international, cross-sectional study. Participants were sampled from neighbourhoods with varied levels of walkability and socioeconomic status. The present analyses of data from the IPEN adult study included 6822 adults aged 18–66 years from 14 cities in ten countries on five continents. Indicators of walkability, public transport access, and park access were assessed in 1·0 km and 0·5 km street network buffers around each participant's residential address with geographic information systems. Mean daily minutes of moderate-to-vigorous-intensity physical activity were measured with 4–7 days of accelerometer monitoring. Associations between environmental attributes and physical activity were estimated using generalised additive mixed models with gamma variance and logarithmic link functions.
Results
Four of six environmental attributes were significantly, positively, and linearly related to physical activity in the single variable models: net residential density (exp[b] 1·006 [95% CI 1·003–1·009]; p=0·001), intersection density (1·069 [1·011–1·130]; p=0·019), public transport density (1·037 [1·018–1·056]; p=0·0007), and number of parks (1·146 [1·033–1·272]; p=0·010). Mixed land use and distance to nearest public transport point were not related to physical activity. The difference in physical activity between participants living in the most and least activity-friendly neighbourhoods ranged from 68 min/week to 89 min/week, which represents 45–59% of the 150 min/week recommended by guidelines.
Interpretation
Design of urban environments has the potential to contribute substantially to physical activity. Similarity of findings across cities suggests the promise of engaging urban planning, transportation, and parks sectors in efforts to reduce the health burden of the global physical inactivity pandemic.
Funding
Funding for coordination of the IPEN adult study, including the present analysis, was provided by the National Cancer Institute of National Institutes of Health (CA127296) with studies in each country funded by different sources
Novel Technologies for Assessing Dietary Intake: Evaluating the Usability of a Mobile Telephone Food Record Among Adults and Adolescents
The development of a mobile telephone food record has the potential to ameliorate much of the burden associated with current methods of dietary assessment. When using the mobile telephone food record, respondents capture an image of their foods and beverages before and after eating. Methods of image analysis and volume estimation allow for automatic identification and volume estimation of foods. To obtain a suitable image, all foods and beverages and a fiducial marker must be included in the image
Associations of built environment and proximity of food outlets with weight status:Analysis from 14 cities in 10 countries
The study aimed to examine associations of neighborhood built environments and proximity of food outlets (BE measures) with body weight status using pooled data from an international study (IPEN Adult). Objective BE measures were calculated using geographic information systems for 10,008 participants (4463 male, 45%) aged 16-66 years in 14 cities. Participants self-reported proximity to three types of food outlets. Outcomes were body mass index (BMI) and overweight/obesity status. Male and female weight status associations with BE measures were estimated by generalized additive mixed models. Proportion (95% CI) of overweight (BMI 25 to = 30) from 2.9% (1.3, 4.4) to 31.3% (27.7, 34.7), with Hong Kong being the lowest and Cuernavaca, Mexico highest for both proportions. Results differed by sex. Greater street intersection density, public transport density and perceived proximity to restaurants (males) were associated with lower odds of overweight/obesity (BMI >= 25). Proximity to public transport stops (females) was associated with higher odds of overweight/obesity. Composite BE measures were more strongly related to BMI and overweight/obesity status than single variables among men but not women. One standard deviation improvement in the composite measures of BE was associated with small reductions of 0.1-0.5% in BMI but meaningful reductions of 2.5-5.3% in the odds of overweight/obesity. Effects were linear and generalizable across cities. Neighborhoods designed to support public transport, with food outlets within walking distance, may contribute to global obesity control
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