466 research outputs found
Association between fast food purchasing and the local food environment
Objective: In this study, an instrument was created to measure the healthy and unhealthy characteristics of food environments and investigate associations between the whole of the food environment and fast food consumption.Design and subjects: In consultation with other academic researchers in this field, food stores were categorised to either healthy or unhealthy and weighted (between +10 and −10) by their likely contribution to healthy/unhealthy eating practices. A healthy and unhealthy food environment score (FES) was created using these weightings. Using a cross-sectional study design, multilevel multinomial regression was used to estimate the effects of the whole food environment on the fast food purchasing habits of 2547 individuals.Results: Respondents in areas with the highest tertile of the healthy FES had a lower likelihood of purchasing fast food both infrequently and frequently compared with respondents who never purchased, however only infrequent purchasing remained significant when simultaneously modelled with the unhealthy FES (odds ratio (OR) 0.52; 95% confidence interval (CI) 0.32–0.83). Although a lower likelihood of frequent fast food purchasing was also associated with living in the highest tertile of the unhealthy FES, no association remained once the healthy FES was included in the models. In our binary models, respondents living in areas with a higher unhealthy FES than healthy FES were more likely to purchase fast food infrequently (OR 1.35; 95% CI 1.00–1.82) however no association was found for frequent purchasing.Conclusion: Our study provides some evidence to suggest that healthier food environments may discourage fast food purchasing.<br /
Benefits and risks of the hormetic effects of dietary isothiocyanates on cancer prevention
The isothiocyanate (ITC) sulforaphane (SFN) was shown at low levels (1-5 µM) to promote cell proliferation to 120-143% of the controls in a number of human cell lines, whilst at high levels (10-40 µM) it inhibited such cell proliferation. Similar dose responses were observed for cell migration, i.e. SFN at 2.5 µM increased cell migration in bladder cancer T24 cells to 128% whilst high levels inhibited cell migration. This hormetic action was also found in an angiogenesis assay where SFN at 2.5 µM promoted endothelial tube formation (118% of the control), whereas at 10-20 µM it caused significant inhibition. The precise mechanism by which SFN influences promotion of cell growth and migration is not known, but probably involves activation of autophagy since an autophagy inhibitor, 3-methyladenine, abolished the effect of SFN on cell migration. Moreover, low doses of SFN offered a protective effect against free-radical mediated cell death, an effect that was enhanced by co-treatment with selenium. These results suggest that SFN may either prevent or promote tumour cell growth depending on the dose and the nature of the target cells. In normal cells, the promotion of cell growth may be of benefit, but in transformed or cancer cells it may be an undesirable risk factor. In summary, ITCs have a biphasic effect on cell growth and migration. The benefits and risks of ITCs are not only determined by the doses, but are affected by interactions with Se and the measured endpoint
The Reproducibility of Blood Acid Base Responses in Male Collegiate Athletes Following Individualised Doses of Sodium Bicarbonate: A Randomised Controlled Crossover Study
Background: Current evidence suggests sodium bicarbonate (NaHCO3) should be ingested based upon the individualised alkalotic peak of either blood pH or bicarbonate (HCO3−) because of large inter-individual variations (10–180 min). If such a strategy is to be practical, the blood analyte response needs to be reproducible. Objective: This study aimed to evaluate the degree of reproducibility of both time to peak (TTP) and absolute change in blood pH, HCO3− and sodium (Na+) following acute NaHCO3 ingestion. Methods: Male participants (n = 15) with backgrounds in rugby, football or sprinting completed six randomised treatments entailing ingestion of two doses of 0.2 g·kg−1 body mass (BM) NaHCO3 (SBC2a and b), two doses of 0.3 g·kg−1 BM NaHCO3 (SBC3a and b) or two control treatments (CON1a and b) on separate days. Blood analysis included pH, HCO3− and Na+ prior to and at regular time points following NaHCO3 ingestion over a 3-h period. Results: HCO3− displayed greater reproducibility than pH in intraclass correlation coefficient (ICC) analysis for both TTP (HCO3− SBC2 r = 0.77, P = 0.003; SBC3 r = 0.94, P < 0.001; pH SBC2 r = 0.62, P = 0.044; SBC3 r = 0.71, P = 0.016) and absolute change (HCO3− SBC2 r = 0.89, P < 0.001; SBC3 r = 0.76, P = 0.008; pH SBC2 r = 0.84, P = 0.001; SBC3 r = 0.62, P = 0.041). Conclusion: Our results indicate that both TTP and absolute change in HCO3− is more reliable than pH. As such, these data provide support for an individualised NaHCO3 ingestion strategy to consistently elicit peak alkalosis before exercise. Future work should utilise an individualised NaHCO3 ingestion strategy based on HCO3− responses and evaluate effects on exercise performance
Sodium bicarbonate supplementation improves severe-intensity intermittent exercise under moderate acute hypoxic conditions
Acute moderate hypoxic exposure can substantially impair exercise performance, which occurs with a concurrent exacerbated rise in hydrogen cation (H+) production. The purpose of this study was therefore, to alleviate this acidic stress through sodium bicarbonate (NaHCO3) supplementation and determine the corresponding effects on severe intensity intermittent exercise performance. Eleven recreationally active individuals participated in this randomised, double-blind, crossover study performed under acute normobaric hypoxic conditions (FiO2% = 14.5%). Pre-experimental trials involved the determination of time to attain peak bicarbonate anion concentrations ([HCO3-]) following NaHCO3 ingestion. The intermittent exercise tests involved repeated 60 s work in their severe intensity domain and 30 s recovery at 20 W to exhaustion. Participants ingested either 0.3 g·kg bm-1 of NaHCO3 or a matched placebo of 0.21 g·kg bm-1 of sodium chloride prior to exercise. Exercise tolerance (+110.9 ± 100.6 s; 95% CI: 43.3 to 178 s; g = 1.0) and work performed in the severe intensity domain (+5.8 ± 6.6 kJ; 95% CI: 1.3 to 9.9 kJ; g = 0.8) were enhanced with NaHCO3 supplementation. Furthermore, a larger post-exercise blood lactate concentration was reported in the experimental group (+4 ± 2.4 mmol·l-1; 95% CI: 2.2 to 5.9; g = 1.8), while blood [HCO3-] and pH remained elevated in the NaHCO3 condition throughout experimentation. In conclusion, this study reported a positive effect of NaHCO3 under acute moderate hypoxic conditions during intermittent exercise and therefore, may offer an ergogenic strategy to mitigate hypoxic induced declines in exercise performance
An outbreak of Japanese encephalitis in a non-endemic region of north-east India
Background There are few comprehensive reports of epidemic Japanese encephalitis in a previously unaffected region. We report our experience of a first-ever outbreak of it in Sonitpur District, Assam, India, with 45 laboratory-confirmed cases at a single hospital.
Method Between 2 July and 11 August 2008, patients meeting the WHO definition of acute encephalitis syndrome were assessed in a single hospital and had tests including blood and cerebrospinal fluid for Japanese encephalitis antibody titres.
Results Ninety-six cases meeting the definition of acute encephalitis syndrome were identified with 45 cases of Japanese encephalitis confirmed by cerebrospinal fluid or blood results. For Japanese encephalitis positive patients, mean age was 36 (range 4–80). Of the 45, 11 (24%) died and a further 21 (47%) had significant residual deficits. Focal neurological signs (40%) and seizures (25%) were common.
Conclusion An effective Japanese encephalitis vaccine is the key intervention for limiting the population impact of this disease. Identification of these cases led to a district-wide mass vaccination campaign
Resolving the neural circuits of anxiety
Although anxiety disorders represent a major societal problem demanding new therapeutic targets, these efforts have languished in the absence of a mechanistic understanding of this subjective emotional state. While it is impossible to know with certainty the subjective experience of a rodent, rodent models hold promise in dissecting well-conserved limbic circuits. The application of modern approaches in neuroscience has already begun to unmask the neural circuit intricacies underlying anxiety by allowing direct examination of hypotheses drawn from existing psychological concepts. This information points toward an updated conceptual model for what neural circuit perturbations could give rise to pathological anxiety and thereby provides a roadmap for future therapeutic development.National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (NIH Director’s New Innovator Award DP2-DK-102256-01)National Institute of Mental Health (U.S.) (NIH) R01-MH102441-01)JPB Foundatio
A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome
Down syndrome, caused by an extra copy of chromosome 21, is associated with a greatly increased risk of early onset Alzheimer disease. It is thought that this risk is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP), an Alzheimer risk factor, although the possession of extra copies of other chromosome 21 genes may also play a role. Further study of the mechanisms underlying the development of Alzheimer disease in Down syndrome could provide insights into the mechanisms that cause dementia in the general population
Sublinear-Time Language Recognition and Decision by One-Dimensional Cellular Automata
After an apparent hiatus of roughly 30 years, we revisit a seemingly
neglected subject in the theory of (one-dimensional) cellular automata:
sublinear-time computation. The model considered is that of ACAs, which are
language acceptors whose acceptance condition depends on the states of all
cells in the automaton. We prove a time hierarchy theorem for sublinear-time
ACA classes, analyze their intersection with the regular languages, and,
finally, establish strict inclusions in the parallel computation classes
and (uniform) . As an addendum, we introduce and
investigate the concept of a decider ACA (DACA) as a candidate for a decider
counterpart to (acceptor) ACAs. We show the class of languages decidable in
constant time by DACAs equals the locally testable languages, and we also
determine as the (tight) time complexity threshold for DACAs
up to which no advantage compared to constant time is possible.Comment: 16 pages, 2 figures, to appear at DLT 202
Co-design of a personalised digital intervention to improve vegetable intake in adults living in Australian rural communities
\ua9 2024, The Author(s). Background: Diets low in vegetables are a main contributor to the health burden experienced by Australians living in rural communities. Given the ubiquity of smartphones and access to the Internet, digital interventions may offer an accessible delivery model for a dietary intervention in rural communities. However, no digital interventions to address low vegetable intake have been co-designed with adults living in rural areas. This paper describes the co-design of a digital intervention to improve vegetable intake with rural community members and research partners. Methods: Active participants in the co-design process were adults ≥ 18 years living in three rural Australian communities (total n = 57) and research partners (n = 4) representing three local rural governments and one peak non-government health organisation. An iterative co-design process was undertaken to understand the needs (pre-design phase) and ideas (generative phase) of the target population. Eight online workshops and a community survey were conducted between July and December 2021. The MoSCoW prioritisation method was used to help participants identify the ‘Must-have, Should-have, Could-have, and Won’t-have or will not have right now’ features and functions of the digital intervention. Workshops were transcribed and inductively analysed using NVivo. Convergent and divergent themes were identified between the workshops and community survey to identify how to implement the digital intervention in the community. Results: Consensus was reached on a concept for a digital intervention that addressed individual and food environment barriers to vegetable intake, specific to rural communities. Implementation recommendations centred on (i) food literacy approaches to improve skills via access to vegetable-rich recipes and healthy eating resources, (ii) access to personalisation options and behaviour change support, and (iii) improving the community food environment by providing information on and access to local food initiatives. Conclusions: Rural-dwelling adults expressed preferences for personalised intervention features that can enhance food literacy and engagement with community food environments. This research will inform the development of the prototyping (evaluation phase) and feasibility testing (post-design phase) of this intervention
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