Inflammatory cytokines, high-sensitivity C-reactive protein, and risk of one-year vascular events, death, and poor functional outcome after stroke and transient ischemic attack.

BACKGROUND: Inflammation driven by pro-inflammatory cytokines is a new therapeutic target in coronary disease. Few data exist on the association of key upstream cytokines and post-stroke recurrence. In a prospective cohort study, we investigated the association between pivotal cytokines, high-sensitivity C-reactive protein (hsCRP) and one-year outcomes. METHODS: BIO-STROKETIA is a multi-center prospective cohort study of non-severe ischemic stroke (modified Rankin score ≤ 3) and transient ischemic attack. Controls were patients with transient symptoms attending transient ischemic attack clinics with non-ischemic final diagnosis. Exclusion criteria were severe stroke, infection, and other pro-inflammatory disease; hsCRP and cytokines (interleukin (IL) 6, IL-1ß, IL-8, IL-10, IL-12, interferon-γ (IFN-γ), tumor-necrosis factor-α (TNF-α)) were measured. The primary outcome was one-year recurrent stroke/coronary events (fatal and non-fatal). RESULTS: In this study, 680 patients (439 stroke, 241 transient ischemic attack) and 68 controls were included. IL-6, IL-1ß, IL-8, IFN-γ, TNF-α, and hsCRP were higher in stroke/transient ischemic attack cases (p ≤ 0.01 for all). On multivariable Cox regression, IL-6, IL-8, and hsCRP independently predicted one-year recurrent vascular events (adjusted hazard ratios (aHR) per-quartile increase IL-6 1.31, confidence interval (CI) 1.02-1.68, p = 0.03; IL-8 1.47, CI 1.15-1.89, p = 0.002; hsCRP 1.28, CI 1.01-1.62, p = 0.04). IL-6 (aHR 1.98, CI 1.26-3.14, p = 0.003) and hsCRP (aHR 1.81, CI 1.20-2.74, p = 0.005) independently predicted one-year fatality. IL-6 and hsCRP (adjusted odds ratio per-unit increase 1.02, CI 1.01-1.04) predicted poor functional outcome, with a trend for IL-1ß (p = 0.054). CONCLUSION: Baseline inflammatory cytokines independently predicted late recurrence, supporting a rationale for randomized trials of anti-inflammatory agents for prevention after stroke and suggesting that targeted therapy to high-risk patients with high baseline inflammation may be beneficial.

Correction: A novel scaling methodology to reduce the biases associated with missing data from commercial activity monitors.

[This corrects the article DOI: 10.1371/journal.pone.0235144.].

A novel scaling methodology to reduce the biases associated with missing data from commercial activity monitors.

BACKGROUND: Commercial physical activity monitors have wide utility in the assessment of physical activity in research and clinical settings, however, the removal of devices results in missing data and has the potential to bias study conclusions. This study aimed to evaluate methods to address missingness in data collected from commercial activity monitors. METHODS: This study utilised 1526 days of near complete data from 109 adults participating in a European weight loss maintenance study (NoHoW). We conducted simulation experiments to test a novel scaling methodology (NoHoW method) and alternative imputation strategies (overall/individual mean imputation, overall/individual multiple imputation, Kalman imputation and random forest imputation). Methods were compared for hourly, daily and 14-day physical activity estimates for steps, total daily energy expenditure (TDEE) and time in physical activity categories. In a second simulation study, individual multiple imputation, Kalman imputation and the NoHoW method were tested at different positions and quantities of missingness. Equivalence testing and root mean squared error (RMSE) were used to evaluate the ability of each of the strategies relative to the true data. RESULTS: The NoHoW method, Kalman imputation and multiple imputation methods remained statistically equivalent (p<0.05) for all physical activity metrics at the 14-day level. In the second simulation study, RMSE tended to increase with increased missingness. Multiple imputation showed the smallest RMSE for Steps and TDEE at lower levels of missingness (<19%) and the Kalman and NoHoW methods were generally superior for imputing time in physical activity categories. CONCLUSION: Individual centred imputation approaches (NoHoW method, Kalman imputation and individual Multiple imputation) offer an effective means to reduce the biases associated with missing data from activity monitors and maximise data retention.

Social, temporal and situational influences on meat consumption in the UK population.

The amount of meat consumed is having a negative impact on both health and the environment. This study investigated the probability of eating meat and the amount eaten at a meal within different social, temporal and situational contexts. Dietary intake data from 4-day diet diaries of adults (19 years and above) taken from the UK National Diet and Nutrition Survey (2008/9-2013/14) were used for the analysis. Individual eating occasions were identified and the effects of where the food was eaten, with whom, day of the week, age and gender on the probability of eating meat and amount of meat eaten were modelled using general linear mixed models. Each factor showed distinctive effects on the probability of eating meat and the amount consumed. The amount of meat eaten was greater when eating with family members compared to when alone or with other companions. Both the probability and amount of meat eaten in a single eating occasion were higher on Sundays compared to the rest of the week. Eating out (e.g. restaurants/cafes) increased the probability of consuming meat and the amount compared to other situations (e.g. home, work). When considering the factors influencing meat consumption, attention must be paid to the effects of social, temporal, and situational factors as they all work to shape consumption behaviour. This information should be used in the design of interventions and development of policies for the most effective way to reduce meat consumption.

A randomised controlled trial comparing a dietary antiplatelet, the water-soluble tomato extract Fruitflow, with 75 mg aspirin in healthy subjects.

BACKGROUND/OBJECTIVES: Increasing numbers of food ingredients are gaining acknowledgement, via regulated health claims, of benefits to human health. One such is a water-soluble tomato extract, Fruitflow (FF), a dietary antiplatelet. We examined relative platelet responses to FF and to 75 mg aspirin (ASA) in healthy subjects. SUBJECTS/METHODS: A total of 47 healthy subjects completed a double-blinded randomised controlled trial following a crossover design. Acute and 7-day treatments with 75 mg ASA were compared with control with and without concomitant FF, over a 5-h timecourse. Platelet aggregation response agonist, platelet thromboxane A2 release, plasma clotting times and time to form a primary haemostatic clot (PFA-100 closure time, TTC) were measured. RESULTS: Administration of all treatments lowered platelet function and thromboxane A2 generation, and extended the TTC, relative to baseline (P<0.001) and to control (P<0.001). Plasma clotting times were not affected. A single 75 mg dose of ASA showed approximately equal efficacy to a dose of FF, whereas daily 75 mg ASA was approximately three times as effective after 7 days (P=0.002). Platelet responses were heterogenous with distinct weak and strong responder groups. Weak ASA responders retained a functional platelet response to collagen agonist and were responsive to FF. Concomitant FF and ASA did not lead to significant additive effects. CONCLUSIONS: The suppression of platelet function observed after consuming FF is approximately one-third that of daily 75 mg ASA. The reversible action of FF renders it less likely to overextend the time to form a primary haemostatic clot than ASA, an important safety consideration for primary prevention.

Modelling the associations between fat-free mass, resting metabolic rate and energy intake in the context of total energy balance.

BACKGROUND: The relationship between body composition, energy expenditure and ad libitum energy intake (EI) has rarely been examined under conditions that allow any interplay between these variables to be disclosed. OBJECTIVE: The present study examined the relationships between body composition, energy expenditure and EI under controlled laboratory conditions in which the energy density and macronutrient content of the diet varied freely as a function of food choice. METHODS: Fifty-nine subjects (30 men: mean body mass index=26.7±4.0 kg m(-2); 29 women: mean body mass index=25.4±3.5 kg m(-)(2)) completed a 14-day stay in a residential feeding behaviour suite. During days 1 and 2, subjects consumed a fixed diet designed to maintain energy balance. On days 3-14, food intake was covertly measured in subjects who had ad libitum access to a wide variety of foods typical of their normal diets. Resting metabolic rate (RMR; respiratory exchange), total daily energy expenditure (doubly labelled water) and body composition (total body water estimated from deuterium dilution) were measured on days 3-14. RESULTS: Hierarchical multiple regression indicated that after controlling for age and sex, both fat-free mass (FFM; P<0.001) and RMR (P<0.001) predicted daily EI. However, a mediation model using path analysis indicated that the effect of FFM (and fat mass) on EI was fully mediated by RMR (P<0.001). CONCLUSIONS: These data indicate that RMR is a strong determinant of EI under controlled laboratory conditions where food choice is allowed to freely vary and subjects are close to energy balance. Therefore, the conventional adipocentric model of appetite control should be revised to reflect the influence of RMR.

Plausible self-reported dietary intakes in a residential facility are not necessarily reliable.

BACKGROUND/OBJECTIVES: Comparing reported energy intakes with estimated energy requirements as multiples of basal metabolic rate (Ein:BMR) is an established method of identifying implausible food intake records. The present study aimed to examine the validity of self-reported food intakes believed to be plausible. SUBJECTS/METHODS: One hundred and eighty men and women were provided with all food and beverages for two consecutive days in a residential laboratory setting. Subjects self-reported their food and beverage intakes using the weighed food diary method (WDR). Investigators covertly measured subjects' actual consumption over the same period. Subjects also reported intakes over four consecutive days at home. BMR was measured by indirect calorimetry. RESULTS: Average reported energy intakes were significantly lower than actual intakes (11.2 and 11.8 MJ/d, respectively, P<0.001). Two-thirds (121) of the WDR were under-reported to varying degrees. Only five of these were considered as implausible using an Ein:BMR cut-off value of 1.03*BMR. Under-reporting of food and beverage intakes, as measured by the difference between reported and actual intake, was evident at all levels of Ein;BMR. Reported energy intakes were lower still (10.2 MJ/d) while subjects were at home. CONCLUSIONS: Under-recording of self-reported food intake records was extensive but very few under-reported food intake records were identified as implausible using energy intake to BMR ratios. Under-recording was evident at all levels of energy intake.

Falls and fractures 2 years after acute stroke: the North Dublin Population Stroke Study.

BACKGROUND: Stroke patients are at increased risk of falls and fractures. The aim of this study was to determine the rate, predictors and consequences of falls within 2 years after stroke in a prospective population-based study in North Dublin, Ireland. DESIGN: Prospective population-based cohort study. SUBJECTS: 567 adults aged >18 years from the North Dublin Population Stroke Study. METHODS: Participants were enrolled from an Irish urban population of 294,592 individuals, according to recommended criteria. Patients were followed for 2 years. Outcome measures included death, modified Rankin Scale (mRS), fall and fracture rate. RESULTS: At 2 years, 23.5% (124/522) had fallen at least once since their stroke, 14.2% (74/522) had 2 or more falls and 5.4% (28/522) had a fracture. Of 332 survivors at 2 years, 107 (32.2%) had fallen, of whom 60.7% (65/107) had 2 or more falls and 23.4% (25/107) had fractured. In a multivariable model controlling for age and gender, independent risk factors for falling within the first 2 years of stroke included use of alpha-blocker medications for treatment of hypertension (P = 0.02). When mobility measured at Day 90 was included in the model, patients who were mobility impaired (mRS 2-3) were at the highest risk of falling within 2 years of stroke [odds ratio (OR) 2.30, P = 0.003] and those functionally dependent (mRS 4-5) displayed intermediate risk (OR 2.02, P = 0.03) when compared with independently mobile patients. CONCLUSION: Greater attention to falls risk, fall prevention strategies and bone health in the stroke population are required.

Experience and acceptability of diets of varying protein content and glycemic index in an obese cohort: results from the Diogenes trial.

BACKGROUND/OBJECTIVES: To investigate acceptability and tolerability of diets of different protein and glycemic index (GI) content aimed at weight maintenance following a phase of rapid weight loss, as part of a large pan-European dietary intervention trial. SUBJECTS/METHODS: The Diogenes study (www.diogenes-eu.org) consisted of an initial 8-week rapid weight-loss phase (800-1000 kcal/day), followed by a 6-month weight maintenance intervention with five different diets varying in protein and GI content. Measurement of a range of outcomes relating to experience of the Diogenes diets in terms of acceptability, experience and mood were recorded via end of day questionnaires throughout the study. RESULTS: Weight change during the initial weight loss phase weakly, but positively correlated with acceptability of the programme (r range=-0.08 to 0.2, P 0.05, n=685 on four of five dimensions). Success at weight maintenance positively correlated with acceptance of the programme (r range=-0.21 to -0.34, P<0.001, n=540 for all five dimensions). The diets with higher protein content were more acceptable than the low protein (LP) diets, however, no differences between the high vs low GI diets were found concerning acceptability and tolerability. CONCLUSIONS: Results suggest that moderately high protein diets, compared with LP diets, are more acceptable diets for weight control in overweight individuals.

Gestational age, gender and parity specific centile charts for placental weight for singleton deliveries in Aberdeen, UK.

INTRODUCTION: The weight of the placenta is a crude but useful proxy for its function in vivo. Accordingly extremes of placental weight are associated with adverse pregnancy outcomes while even normal variations in placental size may impact lifelong health. Centile charts of placental weight for gestational age and gender are used to identify placental weight extremes but none report the effect of parity. Thus the objective was to produce gender and gestational age specific centile charts for placental weight in nulliparous and multiparous women. METHODS: Data was extracted from the Aberdeen Maternity and Neonatal Databank for all women delivering singleton babies in Aberdeen city and district after 24 weeks gestation. Gestational age specific centile charts for placental weight by gender and parity grouping (n = 88,649 deliveries over a 30 year period) were constructed using the LMS method after exclusion of outliers (0.63% of deliveries meeting study inclusion criteria). RESULTS: Tables and figures are presented for placental weight centiles according to gestational age, gender and parity grouping. Tables are additionally presented for the birth weight to placental weight ratio by gender. Placental weight and the fetal:placental weight ratio were higher in male versus female deliveries. Placental weight was greater in multiparous compared with nulliparous women. DISCUSSION: We present strong evidence that both gender and parity grouping influence placental weight centiles. The differences at any given gestational age are small and the effects of parity are greater overall than those of gender. In contrast the birth weight to placental weight ratio differs by gender only. CONCLUSION: These UK population specific centile charts may be useful in studies investigating the role of the placenta in mediating pregnancy outcome and lifelong health.

Placental weight and efficiency in relation to maternal body mass index and the risk of pregnancy complications in women delivering singleton babies.

Herein we report placental weight and efficiency in relation to maternal BMI and the risk of pregnancy complications in 55,105 pregnancies. Adjusted placental weight increased with increasing BMI through underweight, normal, overweight, obese and morbidly obese categories and accordingly underweight women were more likely to experience placental growth restriction [OR 1.69 (95% CI 1.46-1.95)], while placental hypertrophy was more common in overweight, obese and morbidly obese groups [OR 1.59 (95% CI 1.50-1.69), OR 1.97 (95% CI 1.81-2.15) and OR 2.34 (95% CI 2.08-2.63), respectively]. In contrast the ratio of fetal to placental weight (a proxy for placental efficiency) was lower (P < 0.001) in overweight, obese and morbidly obese than in both normal and underweight women which were equivalent. Relative to the middle tertile reference group (mean 622 g), placental weight in the lower tertile (mean 484 g) was associated with a higher risk of pre-eclampsia, induced labour, spontaneous preterm delivery, stillbirth and low birth weight (P < 0.001). Conversely placental weight in the upper tertile (mean 788 g) was associated with a higher risk of caesarean section, post-term delivery and high birth weight (P < 0.001). With respect to assumed placental efficiency a ratio in the lower tertile was associated with an increased risk of pre-eclampsia, induced labour, caesarean section and spontaneous preterm delivery (P < 0.001) and a ratio in both the lower and higher tertiles was associated with an increased risk of low birth weight (P < 0.001). Placental efficiency was not related to the risk of stillbirth or high birth weight. No interactions between maternal BMI and placental weight tertile were detected suggesting that both abnormal BMI and placental growth are independent risk factors for a range of pregnancy complications.

Stroke recurrence within the time window recommended for carotid endarterectomy.

OBJECTIVE: In the North Dublin Population Stroke Study, we investigated the risk of recurrent stroke within the 14-day time window recommended for endarterectomy. METHODS: In a population-based prospective cohort study, all ischemic stroke patients were identified over 1 year and categorized into those with (CS-positive) and without (CS-negative) ipsilateral carotid stenosis (CS) (≥50% lumen narrowing). Nonprocedural stroke recurrence was determined at 72 hours and 7 and 14 days. RESULTS: Of 365 ischemic stroke patients with carotid imaging, 51 were excluded due to posterior circulation or nonlateralizing stroke, ipsilateral carotid occlusion, or intracranial stenosis, leaving 314 included for analysis (36 CS-positive and 278 CS-negative). Recurrent stroke occurred in 5.6% (2/36) CS-positive and 0.4% (1/278) CS-negative patients by 72 hours of symptom onset (p =0.003), 5.6% (2/36) CS-positive and 0.7% (2/278) CS-negative patients (p =0.01) by 7 days, and in 8.3% (3/36) CS-positive and 1.8% (5/278) CS-negative patients by 14 days (p =0.02). On multivariable Cox regression analysis, CS was the only independent predictor of recurrence at 72 hours (adjusted hazard ratio [HR] 36.1, 95% confidence interval [CI] 1.6-837.5, p =0.03), and 7 days (HR 9.1, 1.1-79.2, p =0.05), with a trend at 14 days (HR 4.6, 0.9-22.8, p =0.06). CONCLUSIONS: Although only a minority of patients with symptomatic CS had a recurrent stroke within 14 days, early recurrent stroke risk was high, particularly within the first 72 hours. Earlier carotid revascularization or improved acute medical treatment may reduce recurrence in this high-risk group.

The behaviour of a neutral model of weight regulated only by body mass.

While there are many mechanisms that may be involved in the regulation of body mass in humans and other animals, it is not so clear how much regulation is needed beyond the negative feedback effect of body mass itself. Here we model weight changes as a stochastic process, and show that it behaves approximately as an autoregressive process. Using published estimates of the energy cost of weight gain, the effect of weight on resting metabolic rate and the daily variation in intake and activity, we show that fluctuations in weight will be small. The effect of excess intake is also examined, and the assumptions and limitations of the model are discussed.

The relationship between BMI and percent body fat, measured by bioelectrical impedance, in a large adult sample is curvilinear and influenced by age and sex.

OBJECTIVE: The study aimed to establish the effects of age, gender and age-gender interactions on BMI-% fat relationships over a wide range of BMI and age. It also aimed to examine controversies regarding linear or curvilinear BMI-% fat relationships. METHODS: Body composition was measured using validated bio-impedance equipment (Bodystat) in a large self-selected sample of 23,627 UK adults aged 18-99 (99% ≤70) years, of which 11,582 were males with a mean BMI of 26.3±4.7 (sd) kg/m(2), and 12,044 females, with a mean BMI of 25.7±5.1 kg/m(2). Multiple regression analysis was used. RESULTS: BMI progressively increased with age in women and plateaued between 40 and 70 years in men. At a fixed BMI, body fat mass increased with age (1.9 kg/decade), as did % fat (1.1-1.4% per decade). The relationship between BMI and % fat was found to be curvilinear (quadratic) rather than linear, with a weaker association at lower BMI. There was also a small but significant age-gender interaction. CONCLUSION: The association between BMI and % body fat is not strong, particularly in the desirable BMI range, is curvilinear rather than linear, and is affected by age.

NET1-mediated RhoA activation facilitates lysophosphatidic acid-induced cell migration and invasion in gastric cancer.

The most lethal aspects of gastric adenocarcinoma (GA) are its invasive and metastatic properties. This aggressive phenotype remains poorly understood. We have recently identified neuroepithelial cell transforming gene 1 (NET1), a guanine exchange factor (GEF), as a novel GA-associated gene. Neuroepithelial cell transforming gene 1 expression is enhanced in GA and it is of functional importance in cell invasion. In this study, we demonstrate the activity of NET1 in driving cytoskeletal rearrangement, a key pathological mechanism in gastric tumour cell migration and invasion. Neuroepithelial cell transforming gene 1 expression was increased 10-fold in response to treatment with lysophosphatidic acid (LPA), resulting in an increase in active levels of RhoA and a 2-fold increase in cell invasion. Lysophosphatidic acid-induced cell invasion and migration were significantly inhibited using either NET1 siRNA or a RhoA inhibitor (C3 exoenzyme), thus indicating the activity of both NET1 and RhoA in gastric cancer progression. Furthermore, LPA-induced invasion and migration were also significantly reduced in the presence of cytochalasin D, an inhibitor of cytoskeletal rearrangements. Neuroepithelial cell transforming gene 1 knockdown resulted in AGS cell rounding and a loss of actin filament organisation, demonstrating the function of NET1 in actin organisation. These data highlight the importance of NET1 as a driver of tumour cell invasion, an activity mediated by RhoA activation and cytoskeletal reorganisation.

Assessment of body image in obesity using a digital morphing technique.

BACKGROUND: Historically, body image research has relied on generic, whole body outlines, which may not be suited to obese individuals. The development of computer generated, individualized digital images to represent body image may be more effective. METHODS: Sixty volunteers participated, with three categories of subject: lean, obese and lean regular exercisers. Body image was assessed using a digital morphing technique in comparison to two standard paper questionnaires. RESULTS: Using the novel digital morphing tool, obese subjects displayed poorer body awareness (perception) than their lean counterparts (P = 0.03), significantly over-estimating their actual body size. Both genders overestimated body size to a similar degree. For body satisfaction, females wished to be smaller and males to be larger, identifying gender-specific body regions (P < 0.001). Obese subjects showed greatest dissatisfaction (P < 0.001) with body image. There was significant correlation for body image dissatisfaction (P < 0.05) between the digital technique and the questionnaires, which was highest for the figural stimuli questionnaire (r = 0.80, P < 0.001). CONCLUSIONS: This method represents a novel and alternative approach to rating body image perception (IP) and satisfaction in obese subjects, particularly providing data on specific regional areas. Body image dissatisfaction appears to be both due to poor body IP compounded with the desire to be smaller.

Low-energy reporting and duration of recording period.

Three-day, rather than 7-day, food records are frequently used because mis-reporting of food intake is believed to increase with recording period. Data from the National Diet and Nutrition Survey of adults were used to explore trends in reported energy intake (REI) with day of recording and to compare average REIs from Thursday to Saturday and from Sunday to Tuesday to the complete 7-day record. Although REIs decreased from days 2 to 7, this was by a quantitatively insignificant 49 kJ per day (P=0.026) and well within the measurement error of recorded food intakes. Furthermore, REIs were lowest on the first recording day. The 3- and 7-day averages were similar (mean difference 0.039 (s.d.+/-1.0) MJ (NS), range -3.3 to +4.2 MJ). However, the difference was greater for those reporting higher than average energy intakes because of higher REIs on weekend days. Food intake reporting periods of longer than 3 days and ideally 7 days are preferable.

Comparing different measures of energy expenditure in human subjects resident in a metabolic facility.

OBJECTIVE: To compare energy expenditure (EE) measured by doubly labeled water (DLW) with other measures, both physical and based on subjective questionnaires. DESIGN: A comparison of methods in a stratified sample of adult volunteers. SETTING: The feeding behaviour suite (FBS) at the Rowett Research Institute, Aberdeen. SUBJECTS: A total of 59 subjects, stratified for age, sex and body mass index (BMI). INTERVENTIONS: EE was assessed by DLW (validated using measurements of energy balance), heart rate monitor (HRM), activity monitor (Caltrac), 24-h physical activity diary (PAD) and 7-day physical activity recall. Energy intake was assessed using covert (investigator-weighed) food intake (EI). Data were collected over a 12-day period of residence in the Rowett's FBS. RESULTS: No methods correlated highly with physical activity assessed by DLW. Physical methods correlated more closely than did subjective recording. All methods (except EI) significantly underestimated EE, estimated by DLW. There were no significant differences in association between methods and sex, age, BMI or fat-free mass. CONCLUSION: EE is difficult to measure precisely or accurately with current approaches but physical methods are slightly better than subjective accounts.

Energy density and weight of food effect short-term caloric compensation in men.

OBJECTIVE: The purpose of the study was to examine the effect of energy density and food weight (volume) on subsequent intake. DESIGN: Sixteen lean men were each studied four times during a 2-d protocol at the Rowett's Human Nutrition Unit. On day 1, subjects were fed a mandatory diet at 1.6 x resting metabolic rate (RMR). On day 2, during the mandatory morning period (08.30-12.30) subjects consumed a fixed breakfast (08.30) plus a snack (10.30) in one of four treatments [with values in weight (kg), ED (kJ/100g), Energy (MJ)]: (i) zero intake, 0:0:0 (ii) low energy density (LED), 0.615: 400: 2.46; (iii) high energy density (HED), 0.615: 800: 4.92; (iv) 2 x LED, 1.225: 400: 4.91. From 12.30, throughout the remainder of the day, subjects had ad libitum access to 15 high-protein, 15 high-fat and 15 high-carbohydrate foods. Motivation to eat was tracked hourly using 100 mm line scales. RESULTS: ANOVA showed subjects were hungrier after the zero and LED treatments in the mandatory period (p<0.001). Lunch time EI was 5.0, 3.1, 4.2 and 3.2 MJ on the zero, HED, LED and 2 x LED treatments, respectively (p<0.001). Total ad libitum EI was 11.7, 9.6, 10.3 and 9.5 MJ/d, respectively (p=0.033). Total ad libitum plus mandatory intakes amounted to 11.7, 14.5, 12.6 and 14.4 MJ/d, respectively (p=0.001). Corresponding food intakes were 2.18, 2.39, 2.51 and 3.06 kg/d, respectively (p<0.001). CONCLUSIONS: The present study showed that subjects respond to both the amount of food eaten in the morning and to the energy density of those foods. However, compensation was only partial and short-term. Subjects only compensated EI by approximately 40% and that compensation only occurred at the next meal.

Optimising two-dye microarray designs for estimating associations with a quantitative trait.

We discuss how the samples should be arranged in two-dye microarray studies when the objective is to investigate associations between gene expression and quantitative traits measured on each sample. Because there is typically large between array variation, information about the association will come from the differences in traits and expression measurements between the two values hybridised to the two dyes on the same array. It is shown that within-slide correlation of trait values should be minimised. The arrangement of samples for which this occurs will depend on the trait values in question, and is a computationally demanding problem. An alternative is to minimise the rank correlation. We discuss this and related issues for different combinations of numbers of samples and arrays. Data analysis, including estimation of the variance components, is also described.