81 research outputs found
Incorporating velocity shear into the magneto-Boussinesq approximation
Motivated by consideration of the solar tachocline, we derive, via an asymptotic procedure, a new set of equations incorporating velocity shear and magnetic buoyancy into the Boussinesq approximation. We demonstrate, by increasing the magnetic field scale height, how these equations are linked to the magneto-Boussinesq equations of Spiegel and Weiss (Magnetic buoyancy and the Boussinesq approximation. Geophys. Astrophys. Fluid Dyn. 1982, 22, 219-234)
Openness in participation, assessment, and policy making upon issues of environment and environmental health: a review of literature and recent project results
Issues of environment and environmental health involve multiple interests regarding e.g. political, societal, economical, and public concerns represented by different kinds of organizations and individuals. Not surprisingly, stakeholder and public participation has become a major issue in environmental and environmental health policy and assessment. The need for participation has been discussed and reasoned by many, including environmental legislators around the world. In principle, participation is generally considered as desirable and the focus of most scholars and practitioners is on carrying out participation, and making participation more effective. In practice also doubts regarding the effectiveness and importance of participation exist among policy makers, assessors, and public, leading even to undermining participatory practices in policy making and assessment
A systematic review on the effect of sweeteners on glycemic response and clinically relevant outcomes
<p>Abstract</p> <p>Background</p> <p>The major metabolic complications of obesity and type 2 diabetes may be prevented and managed with dietary modification. The use of sweeteners that provide little or no calories may help to achieve this objective.</p> <p>Methods</p> <p>We did a systematic review and network meta-analysis of the comparative effectiveness of sweetener additives using Bayesian techniques. MEDLINE, EMBASE, CENTRAL and CAB Global were searched to January 2011. Randomized trials comparing sweeteners in obese, diabetic, and healthy populations were selected. Outcomes of interest included weight change, energy intake, lipids, glycated hemoglobin, markers of insulin resistance and glycemic response. Evidence-based items potentially indicating risk of bias were assessed.</p> <p>Results</p> <p>Of 3,666 citations, we identified 53 eligible randomized controlled trials with 1,126 participants. In diabetic participants, fructose reduced 2-hour blood glucose concentrations by 4.81 mmol/L (95% CI 3.29, 6.34) compared to glucose. Two-hour blood glucose concentration data comparing hypocaloric sweeteners to sucrose or high fructose corn syrup were inconclusive. Based on two â€10-week trials, we found that non-caloric sweeteners reduced energy intake compared to the sucrose groups by approximately 250-500 kcal/day (95% CI 153, 806). One trial found that participants in the non-caloric sweetener group had a decrease in body mass index compared to an increase in body mass index in the sucrose group (-0.40 vs 0.50 kg/m<sup>2</sup>, and -1.00 vs 1.60 kg/m<sup>2</sup>, respectively). No randomized controlled trials showed that high fructose corn syrup or fructose increased levels of cholesterol relative to other sweeteners.</p> <p>Conclusions</p> <p>Considering the public health importance of obesity and its consequences; the clearly relevant role of diet in the pathogenesis and maintenance of obesity; and the billions of dollars spent on non-caloric sweeteners, little high-quality clinical research has been done. Studies are needed to determine the role of hypocaloric sweeteners in a wider population health strategy to prevent, reduce and manage obesity and its consequences.</p
Can metabolic plasticity be a cause for cancer? WarburgâWaddington legacy revisited
Fermentation of glucose to lactate in the presence of sufficient oxygen, known as aerobic glycolysis or Warburg effect, is a universal phenotype of cancer cells. Understanding its origin and role in cellular immortalization and transformation has attracted considerable attention in the recent past. Intriguingly, while we now know that Warburg effect is essential for tumor growth and development, it is thought to arise because of genetic and/or epigenetic changes. In contrast to the above, we propose that Warburg effect can also arise due to normal biochemical fluctuations, independent of genetic and epigenetic changes. Cells that have acquired Warburg effect proliferate rapidly to give rise to a population of heterogeneous progenitors of cancer cells. Such cells also generate more lactate and alter the fitness landscape. This dynamic fitness landscape facilitates evolution of cancer cells from its progenitors, in a fashion analogous to Darwinian evolution. Thus, sporadic cancer can also occur first by the acquisition of Warburg effect, then followed by mutation and selection. The idea proposed here circumvents the inherent difficulties associated with the current understanding of tumorigenesis, and is also consistent with many experimental and epidemiological observations. We discuss this model in the context of epigenetics as originally enunciated by Waddington
Cancer metabolism: current perspectives and future directions
Cellular metabolism influences life and death decisions. An emerging theme in cancer biology is that metabolic regulation is intricately linked to cancer progression. In part, this is due to the fact that proliferation is tightly regulated by availability of nutrients. Mitogenic signals promote nutrient uptake and synthesis of DNA, RNA, proteins and lipids. Therefore, it seems straight-forward that oncogenes, that often promote proliferation, also promote metabolic changes. In this review we summarize our current understanding of how âmetabolic transformation' is linked to oncogenic transformation, and why inhibition of metabolism may prove a cancerâČs âAchilles' heel'. On one hand, mutation of metabolic enzymes and metabolic stress sensors confers synthetic lethality with inhibitors of metabolism. On the other hand, hyperactivation of oncogenic pathways makes tumors more susceptible to metabolic inhibition. Conversely, an adequate nutrient supply and active metabolism regulates Bcl-2 family proteins and inhibits susceptibility to apoptosis. Here, we provide an overview of the metabolic pathways that represent anti-cancer targets and the cell death pathways engaged by metabolic inhibitors. Additionally, we will detail the similarities between metabolism of cancer cells and metabolism of proliferating cells
Targeting cancer metabolism: a therapeutic window opens
Genetic events in cancer activate signalling pathways that alter cell metabolism. Clinical evidence has linked cell metabolism with cancer outcomes. Together, these observations have raised interest in targeting metabolic enzymes for cancer therapy, but they have also raised concerns that these therapies would have unacceptable effects on normal cells. However, some of the first cancer therapies that were developed target the specific metabolic needs of cancer cells and remain effective agents in the clinic today. Research into how changes in cell metabolism promote tumour growth has accelerated in recent years. This has refocused efforts to target metabolic dependencies of cancer cells as a selective anticancer strategy.Burroughs Wellcome FundSmith Family FoundationStarr Cancer ConsortiumDamon Runyon Cancer Research FoundationNational Institutes of Health (U.S.
Being lonely or using substances with friends? A cross-sectional study of Hungarian adolescentsâ health risk behaviours
BACKGROUND: Studying adolescents' health risk behaviours is oddly significant in Central and Eastern European countries, where the prevalence of smoking and drinking among 14-18 year old students is significantly high. The goal of our study is to examine the role of social psychological and social behavioural variables in health risk behaviours among Hungarian adolescents. METHODS: Our sample was comprised of three high schools of Debrecen (the second largest city of Hungary). In all, 501 students filled in the questionnaire from 22 classes (14-22 years old). Students aged above 18 years were excluded for the purpose of the study, giving a total sample size of 471 high school students. Descriptive statistics and binary logistic regression analyses were conducted. RESULTS: According to our results (1) social behavioural factors (namely, smoking and alcohol use of the best friend and peer group) proved to be better predictors of adolescents' health risk behaviours as compared to the included social psychological attributes (2); among the latter ones, loneliness and shyness were negatively related with both smoking and drinking, while competitiveness was a predictor of drinking prevalence among boys. CONCLUSIONS: The findings suggest that social behavioural factors, including smoking and drinking of friends, are oddly important predictors of Hungarian adolescents' health risk behaviours. According to our results, health policy should pay more attention to peer norms related to smoking and drinking during school health promotion. Developing health protective social norms may be an indispensable component of effective health promotion in high schools
Genomic reconstruction of the SARS-CoV-2 epidemic in England.
The evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021
The proportion of soil-borne pathogens increases with warming at the global scale
Understanding the present and future distribution of soil-borne plant pathogens is critical to supporting food and fibre production in a warmer world. Using data from a global field survey and a nine-year field experiment, we show that warmer temperatures increase the relative abundance of soil-borne potential fungal plant pathogens. Moreover, we provide a global atlas of these organisms along with future distribution projections under different climate change and land-use scenarios. These projections show an overall increase in the relative abundance of potential plant pathogens worldwide. This work advances our understanding of the global distribution of potential fungal plant pathogens and their sensitivity to ongoing climate and land-use changes, which is fundamental to reduce their incidence and impacts on terrestrial ecosystems globally.This project received funding from the European Unionâs Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 702057 and the European Research Council (ERC) grant agreements no. 242658 (BIOCOM) and no. 647038 (BIODESERT). M.D.-B. is supported by a RamĂłn y Cajal grant from the Spanish Government (agreement no. RYC2018-025483-I) and a MUSGONET grant (LRA17\1193) from the British Ecological Society. F.T.M. also acknowledges funding from Generalitat Valenciana (CIDEGENT/2018/041) and from sDiv, the synthesis centre of the German Centre for Integrative Biodiversity Research HalleâJenaâLeipzig (iDiv). Work on microbial distribution and colonization in the B.K.S. laboratory is funded by the Australian Research Council (DP190103714). B.K.S. also acknowledges a research award by the Humboldt Foundation. C.A.G. and N.E. acknowledge support from iDiv, funded by the German Research Foundation (DFG FZT118) through flexpool proposals 34600850 and 34600844. N.E. also acknowledges support from the ERC under the European Unionâs Horizon 2020 research and innovation programme (grant agreement no. 677232)
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