1,131 research outputs found
Acute and chronic effects of multivitamin/mineral supplementation on objective and subjective energy measures
Background: Vitamins and minerals play an essential role within many cellular processes including energy
production and metabolism. Previously, supplementation with a multivitamin/mineral (MVM) for ≥28 days resulted
in improvements to cognition and subjective state. We have also demonstrated shifts in metabolism during
cognitively demanding tasks following MVM in females, both acutely and following 8-week supplementation. The
current study aimed to assess these effects further in males and females using metabolically challenging exercise
and cognitive tasks.
Methods: The current randomised, placebo-controlled, parallel groups study investigated the effects of a MVM
complex in 82 healthy young (18-35y) exercisers. Subjective ratings and substrate metabolism were assessed during
30 min each of increasingly effortful incremental exercise and demanding cognitive tasks. Assessments took place
on acute study days following a single dose (Day 1) of MVM, containing 3 times recommended daily allowance of
water-soluble vitamins plus CoQ10, and following 4-week supplementation (Day 28).
Results: Energy expenditure (EE) was increased during cognitive tasks following MVM across Day 1 and Day 28,
with greater effects in males. In males, MVM also increased carbohydrate oxidation and energy expenditure during
exercise across Day 1 and Day 28. In females, mental tiredness was lower during exercise; increases in physical
tiredness following 30 min of exercise were attenuated; and stress ratings following cognitive tasks were reduced
following MVM. In males, MVM only lowered mental tiredness following 10 min of exercise. These effects were
apparent irrespective of day, but effects on mental tiredness were greater on Day 28. Ferritin levels were also higher
on Day 28 in those receiving MVM.
Conclusion: These findings extend on existing knowledge, demonstrating increased carbohydrate oxidation and
increased energy expenditure in males following MVM supplementation for the first time. Importantly, they show
modulation of energy expenditure and subjective tiredness following a single dose, providing further evidence for
acute effects of MVM. Differential effects in men and women suggest that sex may play an important role in the
effects of MVM on energy metabolism and should be considered in future research.
Trial registration: ClinicalTrials.gov, NCT03003442. Registered 22nd November 2016 – retrospectively registere
A New Numerical Approach to the Calibration and Interpretation of PEA Measurements
In this paper, a new approach for interpreting raw PEA signals is proposed. The theory behind acoustic wave propagation in ideal (no attenuation and no dispersion) materials and in real materials (with attenuation and dispersion) initially free of space charge is described. A simulation model has been developed for the following: (1) the acoustic signal formation in the PEA apparatus, the transmission of the acoustic waves, their attenuation/dispersion and detection; (2) the instrumental effects of having a capacitive piezoelectric sensor driving a 50 Ohm input impedance amplifier. The various layers of a PEA system were considered in the model and the effect of each layer on the acoustic wave propagation is analyzed. Since the model allowed raw PEA data to be simulated, it can be used to identify potential sources of error in interpreting real PEA measurement data, such as acoustic mismatch between PEA layers, electrode material effects, pulse voltage, etc. The results showed good agreement between the simulated and experimentally obtained data in the case of space charge free samples
Thalamocortical Inputs Show Post-Critical-Period Plasticity
SummaryExperience-dependent plasticity in the adult brain has clinical potential for functional rehabilitation following central and peripheral nerve injuries. Here, plasticity induced by unilateral infraorbital (IO) nerve resection in 4-week-old rats was mapped using MRI and synaptic mechanisms were elucidated by slice electrophysiology. Functional MRI demonstrates a cortical potentiation compared to thalamus 2Â weeks after IO nerve resection. Tracing thalamocortical (TC) projections with manganese-enhanced MRI revealed circuit changes in the spared layer 4 (L4) barrel cortex. Brain slice electrophysiology revealed TC input strengthening onto L4 stellate cells due to an increase in postsynaptic strength and the number of functional synapses. This work shows that the TC input is a site for robust plasticity after the end of the previously defined critical period for this input. Thus, TC inputs may represent a major site for adult plasticity in contrast to the consensus that adult plasticity mainly occurs at cortico-cortical connections
Conservation laws of scaling-invariant field equations
A simple conservation law formula for field equations with a scaling symmetry
is presented. The formula uses adjoint-symmetries of the given field equation
and directly generates all local conservation laws for any conserved quantities
having non-zero scaling weight. Applications to several soliton equations,
fluid flow and nonlinear wave equations, Yang-Mills equations and the Einstein
gravitational field equations are considered.Comment: 18 pages, published version in J. Phys. A:Math. and Gen. (2003).
Added discussion of vorticity conservation laws for fluid flow; corrected
recursion formula and operator for vector mKdV conservation law
An ex vivo, assessor blind, randomised, parallel group, comparative efficacy trial of the ovicidal activity of three pediculicides after a single application - melaleuca oil and lavender oil, eucalyptus oil and lemon tea tree oil, and a "suffocation" pediculicide
Background: There are two components to the clinical efficacy of pediculicides: (i) efficacy against the crawling-stages (lousicidal efficacy); and (ii) efficacy against the eggs (ovicidal efficacy). Lousicidal efficacy and ovicidal efficacy are confounded in clinical trials. Here we report on a trial that was specially designed to rank the clinical ovicidal efficacy of pediculicides. Eggs were collected, pre-treatment and post-treatment, from subjects with different types of hair, different coloured hair and hair of different length.Method: Subjects with at least 20 live eggs of Pediculus capitis (head lice) were randomised to one of three treatment-groups: a melaleuca oil (commonly called tea tree oil) and lavender oil pediculicide (TTO/LO); a eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO); or a "suffocation" pediculicide. Pre-treatment: 10 to 22 live eggs were taken from the head by cutting the single hair with the live egg attached, before the treatment (total of 1,062 eggs). Treatment: The subjects then received a single treatment of one of the three pediculicides, according to the manufacturers' instructions. Post-treatment: 10 to 41 treated live eggs were taken from the head by cutting the single hair with the egg attached (total of 1,183 eggs). Eggs were incubated for 14 days. The proportion of eggs that had hatched after 14 days in the pre-treatment group was compared with the proportion of eggs that hatched in the post-treatment group. The primary outcome measure was % ovicidal efficacy for each of the three pediculicides.Results: 722 subjects were examined for the presence of eggs of head lice. 92 of these subjects were recruited and randomly assigned to: the "suffocation" pediculicide (n = 31); the melaleuca oil and lavender oil pediculicide (n = 31); and the eucalyptus oil and lemon tea tree oil pediculicide (n = 30 subjects). The group treated with eucalyptus oil and lemon tea tree oil had an ovicidal efficacy of 3.3% (SD 16%) whereas the group treated with melaleuca oil and lavender oil had an ovicidal efficacy of 44.4% (SD 23%) and the group treated with the "suffocation" pediculicide had an ovicidal efficacy of 68.3% (SD 38%).Conclusion: Ovicidal efficacy varied substantially among treatments, from 3.3% to 68.3%. The "suffocation" pediculicide and the melaleuca oil and lavender oil pediculicide (TTO/LO) were significantly more ovicidal than eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO) (P < 0.0001). Ranking: 1. "Suffocation" pediculicide (68.3% efficacy against eggs); 2. Melaleuca oil and lavender oil (44.4%) pediculicide; 3. Eucalyptus oil and lemon tea tree oil (3.3%) pediculicide. The "suffocation" pediculicide and TTO/LO are also highly efficacious against the crawling-stages. Thus, the "suffocation" pediculicide and TTO/LO should be recommended as first line treatments.Trial Registration: The study was listed at the Australian/New Zealand Clinical Trial Registry (ANZCTR): reg. no. 12609000884202
Predicting the long-term impact of antiretroviral therapy scale-up on population incidence of tuberculosis.
OBJECTIVE: To investigate the impact of antiretroviral therapy (ART) on long-term population-level tuberculosis disease (TB) incidence in sub-Saharan Africa. METHODS: We used a mathematical model to consider the effect of different assumptions about life expectancy and TB risk during long-term ART under alternative scenarios for trends in population HIV incidence and ART coverage. RESULTS: All the scenarios we explored predicted that the widespread introduction of ART would initially reduce population-level TB incidence. However, many modelled scenarios projected a rebound in population-level TB incidence after around 20 years. This rebound was predicted to exceed the TB incidence present before ART scale-up if decreases in HIV incidence during the same period were not sufficiently rapid or if the protective effect of ART on TB was not sustained. Nevertheless, most scenarios predicted a reduction in the cumulative TB incidence when accompanied by a relative decline in HIV incidence of more than 10% each year. CONCLUSIONS: Despite short-term benefits of ART scale-up on population TB incidence in sub-Saharan Africa, longer-term projections raise the possibility of a rebound in TB incidence. This highlights the importance of sustaining good adherence and immunologic response to ART and, crucially, the need for effective HIV preventive interventions, including early widespread implementation of ART
Mitochondrial Protein Lipoylation and the 2-Oxoglutarate Dehydrogenase Complex Controls HIF1α Stability in Aerobic Conditions.
Hypoxia-inducible transcription factors (HIFs) control adaptation to low oxygen environments by activating genes involved in metabolism, angiogenesis, and redox homeostasis. The finding that HIFs are also regulated by small molecule metabolites highlights the need to understand the complexity of their cellular regulation. Here we use a forward genetic screen in near-haploid human cells to identify genes that stabilize HIFs under aerobic conditions. We identify two mitochondrial genes, oxoglutarate dehydrogenase (OGDH) and lipoic acid synthase (LIAS), which when mutated stabilize HIF1α in a non-hydroxylated form. Disruption of OGDH complex activity in OGDH or LIAS mutants promotes L-2-hydroxyglutarate formation, which inhibits the activity of the HIFα prolyl hydroxylases (PHDs) and TET 2-oxoglutarate dependent dioxygenases. We also find that PHD activity is decreased in patients with homozygous germline mutations in lipoic acid synthesis, leading to HIF1 activation. Thus, mutations affecting OGDHC activity may have broad implications for epigenetic regulation and tumorigenesis.This work was supported by a Wellcome Trust Senior Clinical Research Fellowship to J.A.N. (102770/Z/13/Z), Wellcome Trust Principal Research Fellowship to P.J.L. (084957/Z/08/Z), and the Medical Research Council (A.S.H.C. and C.F.). The Cambridge Institute for Medical Research is in receipt of a Wellcome Trust Strategic Award (100140).This is the final version of the article. It first appeared from Elsevier (Cell Press) via https://doi.org/10.1016/j.cmet.2016.09.01
Mathematical modelling of antimicrobial resistance in agricultural waste highlights importance of gene transfer rate
Antimicrobial resistance is of global concern. Most antimicrobial use is in agriculture; manures and slurry are especially important because they contain a mix of bacteria, including potential pathogens, antimicrobial resistance genes and antimicrobials. In many countries, manures and slurry are stored, especially over winter, before spreading onto fields as organic fertilizer. Thus these are a potential location for gene exchange and selection for resistance. We develop and analyze a mathematical model to quantify the spread of antimicrobial resistance in stored agricultural waste. We use parameters from a slurry tank on a UK dairy farm as an exemplar. We show that the spread of resistance depends in a subtle way on the rates of gene transfer and antibiotic inflow. If the gene transfer rate is high, then its reduction controls resistance, while cutting antibiotic inflow has little impact. If the gene transfer rate is low, then reducing antibiotic inflow controls resistance. Reducing length of storage can also control spread of resistance. Bacterial growth rate, fitness costs of carrying antimicrobial resistance and proportion of resistant bacteria in animal faeces have little impact on spread of resistance. Therefore effective treatment strategies depend critically on knowledge of gene transfer rates
Vaginal progesterone prophylaxis for preterm birth (the OPPTIMUM study): a multicentre, randomised, double-blind trial
Efficacy and Mechanism Evaluation (EME) Programme, a Medical Research Council (MRC) and National
Institute for Health Research (NIHR) partnership. The EME Programme is funded by the MRC and NIHR, with
contributions from the Chief Scientist Office in Scotland and National Institute for Social Care and Research in Wales
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