25 research outputs found
Nonparametric Bayesian modelling of longitudinally integrated covariance functions on spheres
Taking into account axial symmetry in the covariance function of a Gaussian random field is essential when the purpose is modelling data defined over a large portion of the sphere representing our planet. Axially symmetric covariance functions admit a convoluted spectral representation that makes modelling and inference difficult. This motivates the interest in devising alternative strategies to attain axial symmetry, an appealing option being longitudinal integration of isotropic random fields on the sphere. This paper provides a comprehensive theoretical framework to model longitudinal integration on spheres through a nonparametric Bayesian approach. Longitudinally integrated covariances are treated as random objects, where the randomness is implied by the randomised spectrum associated with the covariance function. After investigating the topological support induced by our construction, we give the posterior distribution a thorough inspection. A Bayesian nonparametric model for the analysis of data defined on the sphere is described and implemented, its performance investigated by means of the analysis of both simulated and real data sets
Increased thiamine intake may be required to maintain thiamine status during weight loss in patients with type 2 diabetes
During weight loss, erythrocyte thiamine pyrophosphate (TPP) decreased (221 ± 52 to 195 ± 39 nmol/L, P < 0.05) on a diet with adequate thiamine (1.1 mg/day) but was unchanged (217 ± 55 vs 218 ± 52 nmol/L, NS) on a high thiamine diet (2.8 mg/day). Attention to thiamine status may be required in patients with diabetes after weight loss.Jennifer B. Keogh, X. Cleanthous, T.P. Wycherley, G.D. Brinkworth, M. Noakes, Peter M. Clifto
Weight loss maintenance in women 3 years after following a 12-week structured weight loss program
Crown copyright © 2007 Published by Elsevier on behalf of the Asia Oceania Association for the Study of ObesitySummaryStructured weight loss programs such as those using meal replacements are associated with both short-term and long-term weight loss, but the effectiveness of structured weight loss programs using whole foods has not been established. The primary aim of the present study was to retrospectively establish self-reported weight status in women, 3 years after participation in a 12-week food based structured weight loss program monitored by dietitians. The secondary aim was to determine which factors were associated with successful weight loss maintenance. Eighty-five of the 100 participants who completed the 12-week program participated in an 18-question telephone interview which included self-reported weight. Weight loss from baseline was 3.8 (S.D. 5.5) kg (4.4 (S.D. 6.1) %) (P < 0.001). Overall, 61% of participants weighed less than at baseline, 13% had gained weight, and the remaining 26% had maintained their baseline weight. From baseline, 37 (44%) participants had a clinically important weight loss of ≥ 5%, and were, on average, 9.8 (S.D. 4.2) % lighter (P < 0.001). The remaining 48 (56%) participants (weight loss < 5%) were not significantly different to their weight at baseline (P = 0.77). We conclude that a food based structured weight loss program monitored by dietitians, as defined by this intervention, was associated with long-term weight loss maintenance.:Xenia Cleanthous, Manny Noakes, Jennifer B. Keogh, Philip Mohr and Peter M. Cliftonhttp://www.elsevier.com/wps/find/journaldescription.cws_home/707820/description#descriptio
Timing of protein ingestion relative to resistance exercise training does not influence body composition, energy expenditure, glycaemic control or cardiometabolic risk factors in a hypocaloric, high protein diet in patients with type 2 diabetes
Aim: To investigate timing of protein ingestion relative to resistance exercise training (RT) on body composition, cardiometabolic risk factors, glycaemic control and resting energy expenditure (REE) during weight loss on a high-protein (HP) diet in overweight and obese patients with type 2 diabetes (T2DM).
Methods: Thirty-four men/women with T2DM (age 57 ± 7 years and body mass index 34.9 ± 4.2 kg m−2) were randomly assigned to the ingestion of a HP meal (860 kJ, 21 g protein, 0.7 g fat, 29.6 g carbohydrate) either immediately prior to RT or at least 2 h following RT. All participants followed a 16-week, energy-restricted (6-7 MJ day−1), HP diet (carbohydrate : protein : fat 43 : 33 : 22) and participated in supervised RT (3 day week−1). Outcomes were assessed pre- and postintervention at 16 weeks.
Results: There was an overall reduction in bodyweight (−11.9 ± 6.1 kg), fat mass (−10.0 ± 4.4 kg), fat-free mass (−1.9 ± 3.1 kg), waist circumference (−12.1 ± 5.3 cm), REE (−742 ± 624 kJ day−1), glucose (−1.9 ± 1.7 mmol l−1), insulin (−6.1 ± 6.7 mU l−1) and glycosylated haemoglobin (−1.1 ± 0.1%), p ≤ 0.01 time for all variables, with no difference between groups (p ≥ 0.41 group effect). Strength improved and cardiometabolic risk factors were reduced similarly in both groups; single repetition maximum chest press 11.0 ± 8.7 kg, single repetition maximum lat pull down 9.9 ± 6.0 kg, total cholesterol −0.6 ± 0.5 mmol l−1, high-density lipoprotein cholesterol −0.1 ± 0.2 mmol l−1, low-density lipoprotein cholesterol −0.3 ± 0.5 mmol l−1, triglycerides −0.6 ± 0.7 mmol l−1, blood pressure (systolic/diastolic) −13 ± 10/−7 ± 7 mmHg (p ≤ 0.04 time effect, p ≥ 0.24 group effect).
Conclusion: A HP, energy-restricted diet with RT was effective in improving glycaemic control, body composition, strength and cardiometabolic risk factors in overweight/obese patients with T2DM irrespective of altering the timing of protein ingestion relative to RT.T. P. Wycherley, M. Noakes, P. M. Clifton, X. Cleanthous, J. B. Keogh & G. D. Brinkwort
Long-term follow-up using a higher target range for lamotrigine monitoring
The aims of the study were (1) to review the clinical application of the higher target plasma lamotrigine (LTG) concentration of 3-14 mg/L previously proposed by our therapeutic drug monitoring (TDM) laboratory following our initial study 7 years earlier, and (2) to survey clinical application of LTG assays by experienced neurologists (n = 11) who frequently use LTG. There was a 2.9-fold increase in LTG assay requests received by our laboratory from 1996 to 2003. By comparison, data for the number of LTG prescriptions filled throughout Australia were limited to the 4 years from 1997 to 2000, where a 1.7-fold increase was seen. LTG assay requests increased 1.5-fold in this same 4-year period (r2 = 0.97), indicating that the growth in assay requests paralleled the growth in prescriptions. The distribution of LTG concentrations measured in 2003 was compared with those for 1996 and 1997. This indicated there was a significantly increased (P < 0.01) clinical usage of the higher LTG target range. This result was reinforced by questionnaire responses. Respondents (100% of those surveyed), (1) considered the target LTG concentration (3-14 mg/L) to be one of the primary parameters applied in individualizing LTG dosage regimens, (2) were using target concentrations above 7 mg/L in 75% of patients, and (3) reported dose-limiting toxicities in some (but not all) patients typically at concentrations above, or well above, 13 mg/L. In conclusion, the growth in LTG assay requests received by our laboratory paralleled prescribing of this drug. The clinical use of the higher LTG target concentration range was increased during the 7 years since its introduction, indicating clinical acceptance and therapeutic benefit as well as the absence of long-term adverse effects associated with higher plasma LTG concentrations.Morris, Raymond G.; Lee, Michelle Y. Y.; Cleanthous, Xenia; Black, Andrew
A pilot comprehensive lifestyle intervention program (CLIP) - Comparison with qualitative lifestyle advice and simvastatin on cardiovascular risk factors in overweight hypercholesterolaemic individuals
Data source: Figures & tables, https://doi.org/10.1016/j.numecd.2009.09.002Background and Aims: Escalating costs of pharmaceuticals for cardiovascular management highlight the need to develop effective lifestyle intervention programs to reduce reliance on these agents. The aim of this pilot study was to evaluate the efficacy of a Comprehensive Lifestyle Intervention Program (CLIP) compared with qualitative lifestyle advice (L) and Simvastatin plus qualitative lifestyle (S + L) on cardiovascular risk factors.
Methods and Results: Sixty-five overweight adults with hypercholesterolemia were randomised to either L (qualitative advice on diet, exercise), S + L (20 mg/day Simvastatin plus L) or CLIP (6500 kJ structured menu plan: conventional and functional foods contributing 0.05, all). Blood pressure changes were not different between groups.
Conclusions: The structured CLIP program was more effective than qualitative lifestyle advice in improving weight, waist circumference and LDL-cholesterol without adverse effects on plasma carotenoids over a 6 week period. This program may therefore assist in comprehensive risk factor management, although the sustainability of these benefits needs confirmation.X. Cleanthous, M. Noakes, G.D. Brinkworth, J.B. Keogh, G. Williams, P.M. Clifto
A high-protein diet with resistance exercise training improves weight loss and body composition in overweight and obese patients with Type 2 diabetes
OBJECTIVE: To evaluate the effects of two low-fat hypocaloric diets differing in the carbohydrate-to-protein ratio, with and without resistance exercise training (RT), on weight loss, body composition, and cardiovascular disease (CVD) risk outcomes in overweight/obese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 83 men and women with type 2 diabetes (aged 56.1 ± 7.5 years, BMI 35.4 ± 4.6 kg/m2) were randomly assigned to an isocaloric, energy-restricted diet (female subjects 6 MJ/day, male subjects 7 MJ/day) of either standard carbohydrate (CON; carbohydrate:protein:fat 53:19:26) or high protein (HP; 43:33:22), with or without supervised RT (3 days/week) for 16 weeks. Body weight and composition, waist circumference (WC), and cardiometabolic risk markers were assessed. RESULTS: Fifty-nine participants completed the study. There was a significant group effect (P ≤ 0.04) for body weight, fat mass, and WC with the greatest reductions occuring in HP+RT (weight [CON: −8.6 ± 4.6 kg, HP: −9.0 ± 4.8 kg, CON+RT: −10.5 ± 5.1 kg, HP+RT: −13.8 ± 6.0 kg], fat mass [CON: −6.4 ± 3.4 kg, HP: −6.7 ± 4.0 kg, CON+RT: −7.9 ± 3.7 kg, HP+RT: −11.1 ± 3.7 kg], and WC [CON: −8.2 ± 4.6 cm, HP: −8.9 ± 3.9 cm, CON+RT: −11.3 ± 4.6 cm, HP+RT: −13.7 ± 4.6 cm]). There was an overall reduction (P < 0.001) in fat-free mass (−2.0 ± 2.3 kg), blood pressure (−15/8 ± 10/6 mmHg), glucose (−2.1 ± 2.2 mmol/l), insulin (−4.7 ± 5.4 mU/l), A1C (−1.25 ± 0.94%), triglycerides (−0.47 ± 0.81 mmol/l), total cholesterol (−0.67 ± 0.69 mmol/l), and LDL cholesterol (−0.37 ± 0.53 mmol/l), with no difference between groups (P ≥ 0.17). CONCLUSIONS: An energy-restricted HP diet combined with RT achieved greater weight loss and more favorable changes in body composition. All treatments had similar improvements in glycemic control and CVD risk markers.Thomas P. Wycherley, Manny Noakes, Peter M. Clifton, Xenia Cleanthous, Jennifer B. Keogh and Grant D. Brinkwort
Pseudodifferential operators on Mixed-Norm -modulation spaces
Mixed-norm -modulation spaces were introduced recently by Cleanthous and Georgiadis [Trans.\ Amer.\ Math.\ Soc.\ 373 (2020), no. 5, 3323-3356]. The mixed-norm spaces , , form a family of smoothness spaces that contain the mixed-norm Besov spaces as special cases. In this paper we prove that a pseudodifferential operator with symbol in the H\"ormander class extends to a bounded operator provided 0<\alpha\leq \rho\leq 1, , and $
Kernel and wavelet density estimators on manifolds and more general metric spaces
We consider the problem of estimating the density of observations taking values in classical or nonclassical spaces such as manifolds and more general metric spaces. Our setting is quite general but also sufficiently rich in allowing the development of smooth functional calculus with well localized spectral kernels, Besov regularity spaces, and wavelet type systems. Kernel and both linear and nonlinear wavelet density estimators are introduced and studied. Convergence rates for these estimators are established, which are analogous to the existing results in the classical setting of real-valued variables
