4,676 research outputs found
Signal regeneration techniques for advanced modulation formats
We review recent results on all-optical regeneration of phase encoded signals based on phase sensitive amplification achieved by avoiding phase-to-amplitude conversion in order to facilitate the regeneration of amplitude/phase encoded (QAM) signals
On the Rate of Synthesis of Individual Proteins within and between Different Striated Muscles of the Rat
The turnover of muscle protein is responsive to different (patho)-physiological conditions but little is known about the rate of synthesis at the level of individual proteins or whether this varies between different muscles. We investigated the synthesis rate of eight proteins (actin, albumin, ATP synthase alpha, beta enolase, creatine kinase, myosin essential light chain, myosin regulatory light chain and tropomyosin) in the extensor digitorum longus, diaphragm, heart and soleus of male Wistar rats (352 ± 30 g body weight). Animals were assigned to four groups (n = 3, in each), including a control and groups that received deuterium oxide (2H2O) for 4 days, 7 days or 14 days. Deuterium labelling was initiated by an intraperitoneal injection of 10 μL/g body weight of 99.9% 2H2O-saline, and was maintained by administration of 5% (v/v) 2H2O in drinking water provided ad libitum. Homogenates of the isolated muscles were analysed by 2-dimensional gel electrophoresis and matrix-assisted laser desorption ionisation time of flight mass spectrometry. Proteins were identified against the SwissProt database using peptide mass fingerprinting. For each of the eight proteins investigated, the molar percent enrichment (MPE) of 2H and rate constant (k) of protein synthesis was calculated from the mass isotopomer distribution of peptides based on the amino acid sequence and predicted number of exchangeable C–H bonds. The average MPE (2.14% ± 0.2%) was as expected and was consistent across muscles harvested at different times (i.e., steady state enrichment was achieved). The synthesis rate of individual proteins differed markedly within each muscle and the rank-order of synthesis rates differed among the muscles studied. After 14 days the fraction of albumin synthesised (23% ± 5%) was significantly (p < 0.05) greater than for other muscle proteins. These data represent the first attempt to study the synthesis rates of individual proteins across a number of different striated muscles
Inter-individual variation in nucleotide excision repair in young adults: effects of age, adiposity, micronutrient supplementation and genotype
Nucleotide excision repair (NER) is responsible for repairing bulky helix-distorting DNA lesions and is essential for the maintenance of genomic integrity. Severe hereditary impairment of NER leads to cancers such as those in xeroderma pigmentosum, and more moderate reductions in NER capacity have been associated with an increased cancer risk. Diet is a proven modifier of cancer risk but few studies have investigated the potential relationships between diet and NER. In the present study, the plasmid-based host cell reactivation assay was used to measure the NER capacity in peripheral blood mononuclear cells from fifty-seven volunteers aged 18–30 years before and after 6 weeks of supplementation with micronutrients (selenium and vitamins A, C and E). As a control, nine individuals remained unsupplemented over the same period. Volunteers were genotyped for the following polymorphisms in NER genes: ERCC5 Asp1104His (rs17655); XPC Lys939Gln (rs2228001); ERCC2 Lys751Gnl (rs13181); XPC PAT (an 83 bp poly A/T insertion–deletion polymorphism in the XPC gene). NER capacity varied 11-fold between individuals and was inversely associated with age and endogenous DNA strand breaks. For the first time, we observed an inverse association between adiposity and NER. No single polymorphism was associated with the NER capacity, although significant gene–gene interactions were observed between XPC Lys939Gln and ERCC5 Asp1104His and XPC Lys939Gln and ERCC2 Lys751Gnl. While there was no detectable effect of micronutrient supplementation on NER capacity, there was evidence that the effect of fruit intake on the NER capacity may be modulated by the ERCC2 Lys751Gnl single nucleotide polymorphism
Invited letter to editor in response to: Finland’s handling of selenium is a model in these times of coronavirus infections.
This response by the authors is in reply to a letter from Ulfberg and Stehlik (https://doi.org/10.1017/S0007114520003827) in comment to the authors' orginal article (https://doi.org/10.1017/S0007114520003128) that suggested that SE status was an important factor in determining the host response to viral infections
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Maternal dietary intake and physical activity habits during the postpartum period: associations with clinician advice in a sample of Australian first time mothers
Background
Numerous health benefits are associated with achieving optimal diet and physical activity behaviours during and after pregnancy. Understanding predictors of these behaviours is an important public health consideration, yet little is known regarding associations between clinician advice and diet and physical activity behaviours in postpartum women. The aims of this study were to compare the frequency of dietary and physical activity advice provided by clinicians during and after pregnancy and assess if this advice is associated with postpartum diet and physical activity behaviours.
Methods
First time mothers (n = 448) enrolled in the Melbourne InFANT Extend trial completed the Cancer Council of Australia’s Food Frequency Questionnaire when they were three to four months postpartum, which assessed usual fruit and vegetable intake (serves/day). Total physical activity time, time spent walking and time in both moderate and vigorous activity for the previous week (min/week) were assessed using the Active Australia Survey. Advice received during and following pregnancy were assessed by separate survey items, which asked whether a healthcare practitioner had discussed eating a healthy diet and being physically active. Linear and logistic regression assessed associations of advice with dietary intake and physical activity.
Results
In total, 8.6 % of women met guidelines for combined fruit and vegetable intake. Overall, mean total physical activity time was 350.9 ± 281.1 min/week. Time spent walking (251.97 ± 196.78 min/week), was greater than time spent in moderate (36.68 ± 88.58 min/week) or vigorous activity (61.74 ± 109.96 min/week) and 63.2 % of women were meeting physical activity recommendations. The majority of women reported they received advice regarding healthy eating (87.1 %) and physical activity (82.8 %) during pregnancy. Fewer women reported receiving healthy eating (47.5 %) and physical activity (51.9 %) advice by three months postpartum. There was no significant association found between provision of dietary and/or physical activity advice, and mother’s dietary intakes or physical activity levels.
Conclusions
Healthy diet and physical activity advice was received less after pregnancy than during pregnancy yet no association between receipt of advice and behaviour was observed. More intensive approaches than provision of advice may be required to promote healthy diet and physical activity behaviours in new mothers
Socioeconomic variation in diet and activity-related behaviours of Australian children and adolescents aged 2–16 years
BackgroundEvidence for age-related variation in the relationship between obesity-related behaviours and socioeconomic position may assist in the targeting of dietary and physical activity interventions among children.ObjectiveTo investigate the relationship between different indicators of socioeconomic position and obesity-related behaviours across childhood and adolescence.MethodsData were from 4487 children aged 2 to 16 years participating in the cross-sectional 2007 Australian National Children\u27s Nutrition and Physical Activity Survey. Socioeconomic position was defined by the highest education of the primary or secondary carer and parental income. Activity was assessed using recall methods with physical activity also assessed using pedometers. Intake of energy-dense drinks and snack foods, fruits and vegetables was assessed using 2 × 24-h dietary recalls.ResultsA socioeconomic gradient was evident for each dietary measure (although in age-specific analyses, not for energy-dense snacks in older children), as well as television viewing, but not physical activity. Whether each behaviour was most strongly related to parental income or education of the primary or secondary carer was age and sex dependent. The socioeconomic gradient was strongest for television viewing time and consumption of fruit and energy-dense drinks.ConclusionsA strong socioeconomic gradient in eating behaviours and television viewing time was observed. Relationships for particular behaviours differed by age, sex and how socioeconomic position was defined. Socioeconomic indicators define different population groups and represent different components of socioeconomic position. These findings may provide insights into who should be targeted in preventive health efforts at different life stages
Family history of non-communicable diseases and associations with weight and movement behaviours in Australian school-aged children: A prospective study
Objective: To assess differences in weight status and movement behaviour guideline compliance among children aged 5–12 years with and without a family history of non-communicable diseases (NCDs). Design: Prospective. Setting and participants: Women born between 1973 and 1978 were recruited to the Australian Longitudinal Study on Women’s Health (ALSWH) via the database of the Health Insurance Commission (now Medicare; Australia’s universal health insurance scheme). In 2016–2017, women in that cohort were invited to participate in the Mothers and their Children’s Health Study and reported on their three youngest children (aged <13 years). Data from children aged 5–12 years (n=4416) were analysed. Measures: Mothers reported their children’s height and weight, used to calculate body mass index (kg/m2), physical activity, screen time and sleep. In the 2015 ALSWH Survey, women reported diagnoses and family history of type 2 diabetes, heart disease and hypertension. Logistic regression models determined differences between outcomes for children with and without a family history of NCDs. Results: Boys with a family history of type 2 diabetes had 30% (95% CI: 0.51%–0.97%) and 43% lower odds (95% CI: 0.37%–0.88%) of meeting the sleep and combined guidelines, respectively, and 40% higher odds (95% CI: 1.01%– 1.95%) of being overweight/obese. Girls with a family history of hypertension had 27% lower odds (95% CI: 0.57%–0.93%) of meeting the screen time guidelines. No associations were observed for family history of heart disease. Conclusions: Children who have a family history of type 2 diabetes and hypertension may be at risk of poorer health behaviours from a young age. Mothers with a diagnosis or a family history of these NCDs may need additional support to help their children develop healthy movement behaviours and maintain healthy weight.</jats:sec
Describing objectively measured physical activity levels, patterns, and correlates in a cross sectional sample of infants and toddlers from South Africa.
BACKGROUND: Physical activity is considered to have health benefits across the lifespan but levels, patterns, and correlates have not been well described in infants and toddlers under the age of two years. METHODS: This study aimed to describe objectively and subjectively measured physical activity in a group of South African infants aged 3- to 24-months (n = 140), and to investigate individual and maternal correlates of physical activity in this sample. Infants' physical activity was measured using an Axivity AX3 wrist-worn accelerometer for one week and the mean vector magnitude was calculated. In addition, mothers reported the average amount of time their infant spent in various types of activities (including in front of the TV), their beliefs about infants' physical activity, access to equipment in the home environment, and ages of motor development milestone attainment. Analysis of variance (ANOVA) and pair-wise correlations were used to test age and sex differences and associations with potential correlates. RESULTS: There were significant age and sex effects on the distribution of time spent at different physical activity intensities (Wilks' lambda = 0.06, p < 0.01). In all cases, the trend was for boys to spend more time in higher intensity physical activity and less time in lower intensity activity than girls; and for time spent in higher intensity activities to be higher in older children. Time spent outside was higher in boys, and this reached significance at 18-months (F = 3.84, p = 0.02). Less concern around floor play was associated with higher physical activity at 12-months in females only (p = 0.03, r = 0.54), and no other maternal beliefs were correlated with physical activity. The majority (94%) of children were exceeding TV time recommendations. When controlling for age and sex, overall TV time was positively associated with BMI z-score (β=0.01, p = 0.05). CONCLUSION: This study is the first to show sex and age differences in the patterns of physical activity, and to report on objectively measured and maternal reported physical activity and sedentary behaviour in the first two years of life in South Africa infants. Infants and toddlers should be provided with as many opportunities to be active through play as possible, and TV time should be limited
Parents’ engagement in an Australian school- and home-based group RCT to reduce children’s sitting time and promote physical activity: Transform-Us!
Session - S34 Involvement of parents in multicomponent school-based interventions targeting energy balance related behaviours among children and adolescents: Lessons learned from process evaluation: abstract S34.2Conference Theme: Promoting Healthy Eating and Activity WorldwidePURPOSE: Transform-Us! was a 3-year group RCT aiming to determine the effectiveness of strategies to reduce 8-year old Australian children’s sedentary behaviour (SB) or promote their physical activity (PA), or both (PA+SB) compared with usual practice (C) at school and home. METHOD: Process evaluation data were collected at post--‐intervention (T3) Nov/Dec 2011. Nine newsletters per year were …postprin
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