1,526 research outputs found
The repeatability of the abbreviated (4-h) Oral Fat Tolerance Test and influence of prior acute aerobic exercise
© 2016 The Author(s) Purpose: The Oral Fat Tolerance Test (OFTT) is regarded as a repeatable measure used to assess postprandial triglyceride (TAG) levels, with higher levels observed in cardio-metabolic disorders. Acute aerobic exercise intervention before OFTT reduces the TAG response, but the repeatability of this effect is unknown. The aim of this study was to determine the repeatability of the abbreviated 4-h OFTT with and without immediate prior aerobic exercise. Methods: On four separate days, healthy adult male participants underwent two 4-h OFTT (n = 10) and another two 4-h OFTT with 1-h of standardised moderate intensity aerobic exercise performed immediately before meal ingestion (n = 11). The OFTT meal composition included 75.4 g total fat, 21.7 g carbohydrate and 13.7 g protein. Venous blood was sampled at baseline and hourly up to 4 h after the OFTT meal ingestion, and TAG area under the curve (AUC) was calculated. Results: Nonparametric Bland–Altman analysis of 4-h TAG AUC revealed that 9 of 10 repeat measurements fell within ±15 % of the median TAG AUC for the OFTT. By contrast, two of 11 repeat measurements fell within ±15 % of the median TAG AUC for the OFTT undertaken with 1-h prior aerobic exercise. Conclusions: The 4-h OFTT is a repeatable test of postprandial TAG responses in healthy men. However, aerobic exercise performed immediately before OFTT considerably increases the variability of TAG AUC. These findings have implications for interpretation of research studies investigating exercise intervention performed immediately before OFTT. Future studies should also investigate the repeatability of exercise performed 8–24 h before OFTT
Validity of Telemetric-Derived Measures of Heart Rate Variability : A Systematic Review
Validity of Telemetric-Derived Measures of Heart Rate Variability: A Systematic Review. JEPonline 2016;19(6):64-84. Heart rate variability (HRV) is a widely accepted indirect measure of autonomic function with widespread application across many settings. Although traditionally measured from the ‘gold standard’ criterion electrocardiography (ECG), the development of wireless telemetric heart rate monitors (HRMs) extends the scope of the HRV measurement. However, the validity of telemetric-derived data against the criterion ECG data is unclear. Thus, the purpose of this study was twofold: (a) to systematically review the validity of telemetric HRM devices to detect inter-beat intervals and aberrant beats; and (b) to determine the accuracy of HRV parameters computed from HRM-derived inter-beat interval time series data against criterion ECG-derived data in healthy adults aged 19 to 62 yrs. A systematic review of research evidence was conducted. Four electronic databases were accessed to obtain relevant articles (PubMed, EMBASE, MEDLINE and SPORTDiscus. Articles published in English between 1996 and 2016 were eligible for inclusion. Outcome measures included temporal and power spectral indices (Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology (1996). The review confirmed that modern HRMs (Polar® V800™ and Polar® RS800CX™) accurately detected inter-beat interval time-series data. The HRV parameters computed from the HRM-derived time series data were interchangeable with the ECG-derived data. The accuracy of the automatic in-built manufacturer error detection and the HRV algorithms were not established. Notwithstanding acknowledged limitations (a single reviewer, language bias, and the restricted selection of HRV parameters), we conclude that the modern Polar® HRMs offer a valid useful alternative to the ECG for the acquisition of inter-beat interval time series data, and the HRV parameters computed from Polar® HRM-derived inter-beat interval time series data accurately reflect ECG-derived HRV metrics, when inter-beat interval data are processed and analyzed using identical protocols, validated algorithms and software, particularly under controlled and stable conditions
Enteric viral co-infections: Pathogenesis and perspective
Enteric viral co-infections, infections involving more than one virus, have been reported for a diverse group of etiological agents, including rotavirus, norovirus, astrovirus, adenovirus, and enteroviruses. These pathogens are causative agents for acute gastroenteritis and diarrheal disease in immunocompetent and immunocompromised individuals of all ages globally. Despite virus-virus co-infection events in the intestine being increasingly detected, little is known about their impact on disease outcomes or human health. Here, we review what is currently known about the clinical prevalence of virus-virus co-infections and how co-infections may influence vaccine responses. While experimental investigations into enteric virus co-infections have been limited, we highlight in vivo and in vitro models with exciting potential to investigate viral co-infections. Many features of virus-virus co-infection mechanisms in the intestine remain unclear, and further research will be critical
Testosterone Trajectories and Reference Ranges in a Large Longitudinal Sample of Male Adolescents
Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development.We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant's testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years.The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty.The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics
Coupling Of The B1g Phonon To The Anti-Nodal Electronic States of Bi2Sr2Ca0.92Y0.08Cu2O(8+delta)
Angle-resolved photoemission spectroscopy (ARPES) on optimally doped
Bi2Sr2Ca0.92Y0.08Cu2O(8+delta) uncovers a coupling of the electronic bands to a
40 meV mode in an extended k-space region away from the nodal direction,
leading to a new interpretation of the strong renormalization of the electronic
structure seen in Bi2212. Phenomenological agreements with neutron and Raman
experiments suggest that this mode is the B1g oxygen bond-buckling phonon. A
theoretical calculation based on this assignment reproduces the electronic
renormalization seen in the data.Comment: 4 Pages, 4 Figures Updated Figures and Tex
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Plant layout for rehabilitation centers : a case study and general considerations
This paper approaches the problem of arranging
facilities and moving materials in a sheltered workshop,
or rehabilitation center, employing handicapped people.
Traditional plant layout and material handling principles,
along with human engineering principles, are used for
developing a layout for Open Door Incorporated, a
sheltered workshop located in Corvallis, Oregon. Experience
in developing this layout was used as a basis for
postulating general criteria which should be considered
in laying out any sheltered workshop. The study gives
primary consideration to safety of workers, flexibility
of operation, worker convenience and worker training.
It was found that traditional plant layout principles
required modifications and the human engineering factors
played a critical role in the design
Retrospective cohort study evaluating clinical, biochemical and pharmacological prognostic factors for prostate cancer progression using primary care data
Objectives To confirm the association of previously reported prognostic factors with future progression of localised prostate cancer using primary care data and identify new potential prognostic factors for further assessment in prognostic model development and validation.Design Retrospective cohort study, employing Cox proportional hazards regression controlling for age, prostate specific antigen (PSA), and Gleason score, was stratified by diagnostic stage.Setting Primary care in England.Participants Males with localised prostate cancer diagnosedbetween 01/01/1987 and 31/12/2016 within the Clinical Practice ResearchDatalink database, with linked data from the National Cancer Registration andAnalysis Service and Office for National Statistics.Primary and secondary outcomes Primary outcome measure was prostate cancer mortality. Secondary outcome measures were all-cause mortality and commencing systemic therapy. Up-staging after diagnosis was not used as a secondary outcome owing to significant missing data.Results 10 901 men (mean age 74.38±9.03 years) with localised prostate cancer were followed up for a mean of 14.12 (±6.36) years. 2331 (21.38%) men underwent systemic therapy and 3450 (31.65%) died, including 1250 (11.47%) from prostate cancer. Factors associated with an increased risk of prostate cancer mortality included age; high PSA; current or ex-smoker; ischaemic heart disease; high C reactive protein; high ferritin; low haemoglobin; high blood glucose and low albumin.Conclusions This study identified several new potential prognostic factors for prostate cancer progression, as well as confirming some known prognostic factors, in an independent primary care data set. Further research is needed to develop and validate a prognostic model for prostate cancer progression
Doping dependence of the coupling of electrons to bosonic modes in the single-layer high-temperature Bi2Sr2CuO6 superconductor
A recent highlight in the study of high-Tc superconductors is the observation
of band renormalization / self-energy effects on the quasiparticles. This is
seen in the form of kinks in the quasiparticle dispersions as measured by
photoemission and interpreted as signatures of collective bosonic modes
coupling to the electrons. Here we compare for the first time the self-energies
in an optimally doped and strongly overdoped, non-superconducting single-layer
Bi-cuprate (Bi2Sr2CuO6). Besides the appearance of a strong overall weakening,
we also find that weight of the self-energy in the overdoped system shifts to
higher energies. We present evidence that this is related to a change in the
coupling to c-axis phonons due to the rapid change of the c-axis screening in
this doping range.Comment: 4 pages, 3 figure
Quantitative analysis of Sr2RuO4 ARPES spectra: Many-body interactions in a model Fermi liquid
ARPES spectra hold a wealth of information about the many-body interactions
in a correlated material. However, the quantitative analysis of ARPES spectra
to extract the various coupling parameters in a consistent manner is extremely
challenging, even for a model Fermi liquid system. We propose a fitting
procedure which allows quantitative access to the intrinsic lineshape,
deconvolved of energy and momentum resolution effects, of the correlated
2-dimensional material Sr2RuO4. For the first time in correlated 2-dimensional
materials, we find an ARPES linewidth that is narrower than its binding energy,
a key property of quasiparticles within Fermi liquid theory. We also find that
when the electron-electron scattering component is separated from the
electron-phonon and impurity scattering terms it decreases with a functional
form compatible with Fermi liquid theory as the Fermi energy is approached. In
combination with the previously determined Fermi surface, these results give
the first complete picture of a Fermi liquid system via ARPES. Furthermore, we
show that the magnitude of the extracted imaginary part of the self-energy is
in remarkable agreement with DC transport measurements.Comment: 10 pages, 5 figure
A human STAT1 gain-of-function mutation impairs CD8 + T cell responses against gammaherpesvirus 68
Autosomal dominant STAT1 mutations in humans have been associated with chronic mucocutaneous candidiasis (CMC), as well as with increased susceptibility to herpesvirus infections. Prior studies have focused on mucosal and Th17-mediated immunity agains
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