A New Hand‐Held Indirect Calorimeter to Measure Postprandial Energy Expenditure

Objective: To verify the accuracy of a new hand‐held metabolic rate measuring device (MedGem) in quantifying postprandial energy expenditure (PP EE). MedGem measurements were compared to measurements obtained with a conventional indirect calorimeter (Delta‐Trac). Research Methods and Procedures: The resting metabolic rate of 15 healthy subjects was measured for 20 minutes using Delta‐Trac followed by a 10‐minute measurement period using MedGem. EE was again measured for 7 hours after consumption of a 2510‐kJ breakfast. Measurements were read from the Delta‐Trac for the initial 50 minutes of each hour followed by a single reading from the MedGem after 5 to 10 minutes of measurement. Measured EE was calculated as the average of the total measurement period for Delta‐Trac and for eight readings using MedGem; PP EE was calculated as the average of all measurements obtained after breakfast consumption. Results: There was no difference in resting metabolic rate between the two methods (6455.1 ± 417.6 vs. 6468.5 ± 337.2 kJ/d for Delta‐Trac and MedGem, respectively). Measured EE and PP EE values with Delta‐Trac (7019.1 ± 400.8 and 7099.8 ± 399.2 kJ/d, respectively) and MedGem (6775.6 ± 372.0 and 6819.5 ± 379.9 kJ/d, respectively) were not significantly different. There was no bias detected in any of the measurements made with MedGem compared with those of Delta‐Trac. Discussion: The new hand‐held EE measuring device can accurately track PP EE relative to a conventional indirect calorimetry system and, therefore, provides a new opportunity to assess PP EE in research settings and large‐scale trials.     

Arg64β3‐Adrenoceptor Variant and the Components of Energy Expenditure

Objective: To determine Trp64Arg β₃‐adrenoceptor genotype‐specific differences in the components of energy expenditure. Hypothesis: We hypothesized that resting metabolic rate (RMR) and physical activity levels would be lower and that thermic effect of feeding (TEF) would be higher in those with the Arg64 allele. Research Methods and Procedures: RMR and TEF were measured by indirect calorimetry, physical activity by questionnaire, and total energy expenditure by the doubly labeled water method. Genotype‐specific measures were compared using ANOVA and analysis of covariance (ANCOVA). Results: RMR in Arg64 homozygotes was significantly lower than in Trp64 homozygotes [Arg64, 1373 ± 259 kcal/d (n = 15) vs. Trp64Arg, 1538 ± 238 kcal/d (n = 25) vs. Trp64, 1607 ± 290 kcal/d (n = 22); p < 0.01]. TEF was significantly higher in Arg64 homozygotes compared with Trp64 homozygotes (Arg64, 359 ± 28 kcal/d; Trp64Arg, 322 ± 22 kcal/d; and Trp64, 279 ± 23 kcal/d; p < 0.05). No differences were identified between genotypes in physical activity or in total energy expenditure. Discussion: Our results suggest that the Arg64 β₃‐adrenoceptor allele contributes significantly to the genetic variability in both RMR and TEF.     

Contribution of Different Mechanisms to Compensation for Energy Restriction in the Mouse

Objective: Restriction of energy intake produces weight loss, but the rate of loss is seldom sustained. This is presumed to be a consequence of compensatory reductions in energy expenditure, although the exact contributions of different components to the energy budget remain uncertain. We examined the compensatory responses of mice to a 20% dietary restriction. Research Methods and Procedures: We measured body mass, body fatness, body temperature, and the components of daily energy expenditure for 50 MF1 mice. Forty mice were then placed on a restricted diet at 80% of their ad libitum intake for 50 days. The remaining 10 mice continued to feed ad libitum. Ten days before the end of the restriction period, the same measurements were taken. Results: There were no significant differences between the control and restricted groups in any parameters before restriction. During the restriction period, body mass increased in both the control and restricted groups, but at a slower rate in the restricted mice. The control group increased in both fat and fat free mass; however, although the restricted group increased fat to the same extent as the controls, fat free mass increased to a lesser extent. The contributions of the different components of the expended energy to compensate for the reduced energy intake were energy deposition, 2.2%; resting metabolic rate, 22.3%; and activity, 75.5%. Discussion: Mice were able to compensate almost completely for the restricted energy intake that was achieved by altering the amount of energy required for each component of the energy budget except digestive efficiency.     

Measuring Free‐Living Energy Expenditure and Physical Activity with Triaxial Accelerometry

Objective: To investigate the ability of a newly developed triaxial accelerometer to predict total energy expenditure (EE) (TEE) and activity‐related EE (AEE) in free‐living conditions. Research Methods and Procedures: Subjects were 29 healthy subjects between the ages of 18 and 40. The Triaxial Accelerometer for Movement Registration (Tracmor) was worn for 15 consecutive days. Tracmor output was defined as activity counts per day (ACD) for the sum of all three axes or each axis separately (ACD‐X, ACD‐Y, ACD‐Z). TEE was measured with the doubly labeled water technique. Sleeping metabolic rate (SMR) was measured during an overnight stay in a respiration chamber. The physical activity level was calculated as TEE × SMR^?1, and AEE was calculated as [(0.9 × TEE) ? SMR]. Body composition was calculated from body weight, body volume, and total body water using Siri's three‐compartment model. Results: Age, height, body mass, and ACD explained 83% of the variation in TEE [standard error of estimate (SEE) = 1.00 MJ/d] and 81% of the variation in AEE (SEE = 0.70 MJ/d). The partial correlations for ACD were 0.73 (p < 0.001) and 0.79 (p < 0.001) with TEE and AEE, respectively. When data on SMR or body composition were used with ACD, the explained variation in TEE was 90% (SEE = 0.74 and 0.77 MJ/d, respectively). The increase in the explained variation using three axes instead of one axis (vertical) was 5% (p < 0.05). Discussion: The correlations between Tracmor output and EE measures are the highest reported so far. To measure daily life activities, the use of triaxial accelerometry seems beneficial to uniaxial.     

Hour‐by‐Hour Analysis for Increased Accuracy of Greenhouse Gas Emissions for a Low‐Energy Condominium Design

The seasonal and hourly variation of electricity grid emissions and building operational energy use are generally not accounted for in carbon footprint analyses of buildings. This work presents a technique for and results of such an analysis and quantifies the errors that can be encountered when these variations are not appropriately addressed. The study consists of an hour‐by‐hour analysis of the energy used by four different variations of a five‐story condominium building, with a gross floor area of approximately 9,290 square meters (m²), planned for construction in Markham, Ontario, Canada. The results of the case studied indicate that failure to account for variation can, for example, cause a 4% error in the carbon footprint of a building where ground source heat pumps are used and a 6% and 8% error in accounting for the carbon savings of wind and photovoltaic systems, respectively. After the building envelope was enhanced and sources of alternative energy were incorporated, the embodied greenhouse gas (GHG) emissions were more than 50% of the building's operational emissions. This work illustrates the importance of short‐time‐scale GHG analysis for buildings.     

Effect of a High‐fat Diet on 24‐Hour Pattern of Circulating Adipocytokines in Rats

We have shown a significant disruption of 24‐h pattern of plasma pituitary, adrenal, and gonadal hormones in high‐fat‐fed rats. Our objective was to assess the effect of a high‐fat diet (35% fat) on mean levels and 24‐h pattern of several adipocytokines in rats. A normal diet–fed rats (4% fat) were used as controls. When body weight of high‐fat‐fed rats attained values about 25% higher than controls (after 66 days of treatment), the animals were killed at six different time intervals throughout a 24‐h cycle. Plasma concentrations of insulin, adiponectin, interleukin (IL)‐1, leptin, ghrelin, plasminogen activator inhibitor‐1 (PAI‐1), and monocyte chemoattractant protein‐1 (MCP‐1) were measured in a multianalyte profiling by using the Luminex‐100 system. Tumor necrosis factor α (TNFα) and IL‐6 were measured by enzyme‐linked immunosorbent assay. A significant hyperglycemia developed in high‐fat‐fed rats, together with a significant increase in plasma insulin. Mean levels of plasma adiponectin, IL‐1, IL‐6, TNFα, and leptin augmented, and ghrelin decreased, in high‐fat‐fed rats. The normal daily pattern of plasma insulin, adiponectin, IL‐1, IL‐6, TNFα, leptin, ghrelin, and MCP‐1 became disrupted in high‐fat‐fed rats. The results indicate that a high‐fat diet may bring about signs of insulin resistance and mild inflammation in rats, together with the disruption in daily variations of circulating insulin and ghrelin, and of several adipocytokines including leptin, adiponectin, IL‐1, IL‐6, TNFα, and MCP‐1.     

Low Resting and Sleeping Energy Expenditure and Fat Use Do Not Contribute to Obesity in Women

Objective: Determine whether sleeping and resting energy expenditure and sleeping, resting, and 24‐hour fuel use distinguish obesity‐prone from obesity‐resistant women and whether these metabolic factors explain long‐term weight gain. Research Methods and Procedures: Forty‐nine previously overweight but currently normal‐weight women were compared with 49 never‐overweight controls. To date, 87% of the 98 women have been re‐evaluated after 1 year of follow‐up, without intervention, and 38% after 2 years. Subjects were studied at a General Clinical Research Center after 4 weeks of tightly controlled conditions of energy balance and macronutrient intake. Forty‐nine obesity‐prone weight‐reduced women were group‐matched with 49 never‐overweight obesity‐resistant controls. All were premenopausal, sedentary, and normoglycemic. Energy expenditure and fuel use were assessed using chamber calorimetry. Body composition was assessed using DXA. Results: At baseline, percent body fat was not different between the obesity‐prone and control women (33 ± 4% vs. 32 ± 5%, respectively; p = 0.22). Analysis of covariance results show that after adjusting for lean and fat mass, sleeping and resting energy expenditure of obesity‐prone women was within 2% of controls. Neither sleeping nor resting energy expenditure nor sleeping, resting, or 24‐hour fuel use was significantly different between the groups (p > 0.25). None of the metabolic variables contributed significantly to patterns of weight gain at 1 or 2 years of follow‐up. Discussion: The results suggest that when resting and sleeping energy expenditure and fuel use are assessed under tightly controlled conditions, these metabolic factors do not distinguish obesity‐prone from obesity‐resistant women or explain long‐term weight changes.     

Metabolic Differences in Response to a High-Fat vs. a High-Carbohydrate Diet

Energy expenditure was measured in a group of 7 subjects who received two isocaloric isonitrogenous diets for a period of 9–21 days with a 4–10-day break between diets. Diet 1 was a high-fat diet (83.5 ± 3.6% of total energy). Diet 2 was a high carbohydrate diet (83.1 ± 3.7% of total energy). Resting and postprandial resting metabolic rate were measured by open circuit indirect calorimetry 2–4 times during each metabolic period. Total energy expenditure (TEE) was measured by the doubly labeled water method over an 8–13-day period. The respiratory quotient was measured 2–4 hours after a meal during each metabolic period for the calculation of total energy expenditure by the doubly labeled water method. Levels of total T₃ (TT₃), T₃ uptake, free thyroid index and T₄ were measured at the end of each metabolic period. No significant changes in resting metabolic rate (RMR) were apparent on the two diets (1567 ± 426 kcal/d high-fat diet and 1503 ± 412 kcal/d high-carbohydrate diet n=7, p<0.15). Total energy expenditure measured in 5 subjects was significantly higher during the high-carbohydrate phase of the diet (2443 ± 422 vs. 2078 ± 482 kcal/d p<0.05). Activity estimated from TEE/RMR was greater on the high-carbohydrate diet but only approached statistical significance (p<0.06). Total T₃ was significantly lower and free thyroid index and T₃ uptake were significantly higher at the end of the high fat diet in comparison to the high-carbohydrate diet. These data suggest that individual tolerance to a high-fat diet varies considerably and may significantly lower TEE by changing levels of physical activity. The explanation for changes in thyroid hormone levels independent of changes in metabolic rate remains unclear.     

Association between Serum Leptin Levels and 24‐Hour Blood Pressure in Obese Women

Objective: To assess the relationship between serum leptin and 24‐hour blood pressure (BP) in obese women, according to body fat distribution. Research Methods and Procedures: A cross‐sectional study was carried out in a population of 70 nondiabetic, normotensive, obese women (40 with android and 30 with gynoid type of obesity) and 20 nonobese healthy women as a control group. All subjects underwent 24‐hour ambulatory BP monitoring. Blood samples were collected for serum leptin and plasma insulin measurements. Total cholesterol and high‐density lipoprotein cholesterol were also measured. Results: Serum leptin levels were significantly higher in obese subjects than in controls, and they were more elevated in android obese women than in gynoid ones. Leptin levels were positively related to body mass index (BMI), insulin, and waist and hip circumferences in the android group. Among gynoid subjects, leptin levels showed positive associations with BMI and insulin. In women with android obesity, strong positive correlations (p < 0.001) were found between leptin levels and 24‐hour systolic BP (SBP), daytime SBP, nighttime SBP, 24‐hour diastolic BP (DBP), and daytime DBP. Multiple regression analyses, including age, insulin and leptin concentrations, BMI, and waist and hip circumferences on 24‐hour and daytime SBP and DBP, showed that only leptin levels contributed to the variability of BP. Conclusions: Our study shows that serum leptin levels are directly related to 24‐hour BP levels in normotensive women with android fat distribution, independently of BMI.     

The measurement of resting metabolic rate in preschool children

Objective: This study examined the repeatability of measuring resting metabolic rate (RMR) in preschool children and the effect of different calculation protocols. Research Methods and Procedures: Eleven children (4 females and 7 males) participated in the project. They were recruited through advertisements in local schools and community centers. Resting metabolic rate was measured on 3 occasions over a 2‐week period, each after an overnight fast and each lasting ～20 to 25 minutes. Results were compared using repeated‐measures ANOVA to check for repeatability, and a number of methods of calculating RMR were assessed. Results: Repeatability of RMR measurements was good (coefficient of variation of replicates, 6.8%), with no significant difference between days of measurement. The lowest RMR measurement was obtained when the first 10 minutes were excluded and periods during which large activity was observed were excluded. This measurement was, on average, 4% lower than averaging the measurements after the first 5 minutes, including body movements. Discussion: This study suggests that RMR can be measured in preschool children and that the best method for calculating RMR in these subjects is to exclude periods when large body movements occur and the first 10 minutes of the measurement period. Only a single measurement of RMR is needed to obtain a reliable estimate.     

Self‐Selected Macronutrient Diet Affects Energy and Glucose Metabolism in Brown Fat‐Ablated Mice

Objective: Obese transgenic UCP‐DTA mice have largely ablated brown adipose tissue and develop obesity and diabetes, which are highly susceptible to a high‐fat diet. We investigated macronutrient self‐selection and its effect on development of obesity, diabetes, and energy homeostasis in UCP‐DTA mice. Research Methods and Procedures: UCP‐DTA and wild‐type littermates were fed a semisynthetic macronutrient choice diet (CD) ad libitum from weaning until 17 weeks. Energy homeostasis was assessed by measurement of food intake, food digestibility, body composition, and energy expenditure. Diabetes was assessed by blood glucose measurements and insulin tolerance test. Results: Wild‐type and UCP‐DTA mice showed a high fat preference and increased energy digestion on CD compared with a low‐fat standard diet. On CD, wild‐type mice accumulated less body fat (16.9%) than UCP‐DTA (32.6%) mice, although they had a higher overall energy intake. Compared with wild‐type mice, resting metabolic rate was reduced in UCP‐DTA mice irrespective of diet. UCP‐DTA mice progressively decreased their carbohydrate intake, resulting in an almost complete avoidance of carbohydrate. UCP‐DTA mice developed severe insulin resistance but showed decreased fed and fasted blood glucose on CD. Discussion: In contrast to wild‐type mice, UCP‐DTA mice were not able to reduce their weight gain efficiency on CD. This suggests that, because of the high fat preference of the background strain and the increased metabolic efficiency, brown adipose tissue‐deficient mice still develop obesity and insulin resistance on a macronutrient CD even when decreasing overall energy intake. Through the avoidance of carbohydrates, however, they are able to maintain normoglycemia.     

Comparison of Zinc Reduction with Platinum Reduction for Analysis of Deuterium‐Enriched Water Samples for the Doubly Labeled Water Technique

Objective: Isotope ratio mass spectrometry of hydrogen and oxygen is frequently used to determine total energy expenditure (TEE) using doubly labeled water. Conventionally, hydrogen isotope ratio is determined in hydrogen gas generated from water samples using zinc reduction. We compare this with a new automated platinum method to determine the ratios of hydrogen isotopes in deuterium‐enriched water samples. Research Methods and Procedures: The platinum method of sample preparation was compared with the zinc method in three ways: analytical variation in deuterium enrichment (within sample; n = 51), analytical variation in TEE estimates (within sample set; n = 10), and level of agreement of TEE estimates between both methods (n = 14). Results: For the zinc method, the standard deviation for multiple sets of triplicate ²H₂O sample analysis was ±4.36‰ and ±2.07‰ for platinum. The correlation between TEE estimates when sample sets were analyzed in duplicate was r = 0.89 for zinc and r = 0.83 for platinum. The intercept and slope of the regression line were significantly different from the line of identity for duplicate TEE estimates by zinc but were not different from the line of identity for platinum. After correction for the intra‐assay variation of each method, the correlation between zinc and platinum for TEE was 0.77, and the intercept, but not the slope, of the regression was significantly different from the line of identity. The mean difference between the zinc method and the platinum method was 56 kcal/day, and the 95% confidence interval was ?438 to 550 kcal/day. Discussion: These data suggest that the platinum method is at least as reliable as the zinc method as a sample preparation technique for isotope ratio mass spectrometry of deuterium‐enriched water samples. The platinum method is also less costly and less labor‐intensive than the zinc method.     

Assessment of Free‐Living Physical Activity in Humans: An Overview of Currently Available and Proposed New Measures

The number of physical activity measures and indexes used in the human literature is large and may result in some difficulty for the average investigator to choose the most appropriate measure. Accordingly, this review is intended to provide information on the utility and limitations of the various measures. Its primary focus is the objective assessment of free‐living physical activity in humans based on physiological and biomechanical methods. The physical activity measures have been classified into three categories:

• 1 . Measures based on energy expenditure or oxygen uptake, such as activity energy expenditure, activity‐related time equivalent, physical activity level, physical activity ratio, metabolic equivalent, and a new index of potential interest, daytime physical activity level.
• 2 . Measures based on heart rate monitoring, such as net heart rate, physical activity ratio heart rate, physical activity level heart rate, activity‐related time equivalent, and daytime physical activity level heart rate.
• 3 . Measures based on whole‐body accelerometry (counts/U time).

Quantification of the velocity and duration of displacement in outdoor conditions by satellites using the Differential Global Positioning System may constitute a surrogate for physical activity, because walking is the primary activity of man in free‐living conditions. A general outline of the measures and indexes described above is presented in tabular form, along with their respective definition, usual applications, advantages, and shortcomings. A practical example is given with typical values in obese and non‐obese subjects. The various factors to be considered in the selection of physical activity methods include experimental goals, sample size, budget, cultural and social/environmental factors, physical burden for the subject, and statistical factors, such as accuracy and precision. It is concluded that no single current technique is able to quantify all aspects of physical activity under free‐living conditions, requiring the use of complementary methods. In the future, physical activity sensors, which are of low‐cost, small‐sized, and convenient for subjects, investigators, and clinicians, are needed to reliably monitor, during extended periods in free‐living situations, small changes in movements and grade as well as duration and intensity of typical physical activities.     

Thermal and energetic consequences of nest location and breeding times in Water Pipits (Anthus spinoletta)

Summary The thermal environment has pronounced effects on the energy costs of thermoregulation and affects an animal's allocation of energy to self-maintenance and parental care. Consequently, the selection of reproductive periods, breeding habitats and nest-sites with a favourable microclimate can be advantageous, especially for birds breeding in harsh environments. In this study on Alpine Water Pipits (Anthus spinoletta), we evaluate the importance of spatial and temporal factors on thermoregulatory costs by combining laboratory measurements of metabolic rates under various temperatures with standard operative temperatures (T_es) recorded in the field in different microhabitats. Using these measurements we estimate the thermal and energetic consequences of nest locality and timing of reproduction. Our results show: (1) In the morning, T_es values were much higher on the east-north-east (ENE) slope of a valley than on the west-south-west (WSW) slope; in the afternoon this pattern was reversed. As a consequence, energy costs (E_hour) for thermoregulation on the ENE slope were up to 0.6 RMR (resting metabolic rate at night) lower than on the WSW slope during morning hours and about 0.8 RMR higher during afternoon hours. (2) During the incubation and nestling phases of first and second broods, total energy expenditure for thermoregulation in the daytime (E_daytime) was 0.2–0.3 RMR higher on the ENE slope than on the WSW slope. (3) Within slopes, E_daytime was lower during second broods than during first broods, with differences of 0.06–0.07 RMR during incubation and of 0.32 RMR during nestling care. These differences correspond to the flying costs of females incubating eggs (0.09 RMR) and rearing nestlings (0.25 RMR). We conclude that nest placement in relation to microclimate can improve the female's energy budget, both in terms of the total daily expenditure and its diurnal pattern. From thermal considerations alone, delaying breeding into mid-summer would be advantageous, but this advantage is probably outweighed by the reduced chances for second and replacement clutches and by the necessity to complete moult before migration.

---

Thermische und energetische Konsequenzen von Brutplätzen und Brutzeiten bei Wasserpiepern (Anthus spinoletta)

Zusammenfassung Die Umgebungstemperatur beeinflusst den Energieaufwand für die Thermoregulation und bestimmt somit, wie viel Energie ein Tier für die Selbsterhaltung benötigt und wie viel es für Brutpflege aufwenden kann. Daher ist es vorteilhaft, für die Fortpflanzung Zeiten und Orte mit besonders günstigen mikroklimatischen Bedingungen zu wählen. Das gilt insbesondere für Vögel, die in unwirtlichen Biotopen wie z. B. alpinen Regionen brüten. Wir untersuchten den Einfluss von Brutzeit und -ort auf die energetischen Kosten der Thermoregulation am Beispiel einer Population des Wasserpiepers (Anthus spinoletta) im Dischmatal bei Davos (Schweiz). Dazu verknüpften wir drei verschiedene Datensätze: a) Ruhestoffwechsel (RMR), gemessen an gefangenen Vögeln unter verschiedenen Temperaturen, b) Umgebungs- und Nesttemperaturen im Freiland während der Brutzeit und c) standardisierte operative Temperaturen (T_es), ermittelt mit Kupfervögeln in verschiedenen Mikrohabitaten.Die Ergebnisse zeigen: (1) In den Morgenstunden sind T_es-Werte am Ost-Nord-Ost-Hang (ONO) deutlich höher als am West-Süd-West-Hang (WSW); am Nachmittag sind die Verhältnisse umgekehrt. Als Folge davon sind die Energiekosten (E_hour) der Thermoregulation am ONO-Hang in den Morgenstunden bis zu 0.6 RMR niedriger und nachmittags ca. 0.8 RMR höher als am WSW-Hang. (2) In der Bebrütungs- und Nestlingsphase von Erst-und Zweitbruten war der gesamte Energieaufwand für Thermoregulation während der Tagesstunden (E_daytime) am ONO-Hang 0.2–0.3 RMR höher als am WSW-Hang. (3) Innerhalb jedes Hanges war E_daytime bei Zweitbruten niedriger als bei Erstbruten: 0.06–0.07 RMR während der Bebrütung der Eier und 0.32 RMR während der Nestlingsphase. Diese Größenordnungen entsprechen den Flugkosten von Weibchen während der Bebrütungszeit (0.09 RMR) bzw. der Jungenaufzucht (0.25 RMR).Unsere Ergebnisse belegen, dass die Wahl von klimatisch günstigen Habitaten die Energiebilanz von Brutvögeln verbessern kann, sowohl in Hinblick auf den täglichen Gesamtaufwand als auch bezüglich der Verteilung des Energieverbrauchs über den Tag. Aus thermoregulatorischen Gründen wäre auch eine zeitliche Verlagerung des Brutgeschäfts in die Sommermonate (Juli, August) vorteilhaft. Das würde jedoch die Möglichkeiten für Ersatz-und Zweitbruten verringern und die Zeit für die Mauser vor dem Herbstzug verkürzen. Da in unserem Untersuchungsgebiet diese Faktoren für eine erfolgreiche Fortpflanzung eine größere Bedeutung haben als der Energieaufwand für die Thermoregulation, ist der frühe — energetisch 6–32 % teurere — Brutbeginn der Vögel sinnvoll.

     

A New P2‐Type Layered Oxide Cathode with Extremely High Energy Density for Sodium‐Ion Batteries

Herein, a new P2‐type layered oxide is proposed as an outstanding intercalation cathode material for high energy density sodium‐ion batteries (SIBs). On the basis of the stoichiometry of sodium and transition metals, the P2‐type Na_0.55[Ni_0.1Fe_0.1Mn_0.8]O₂ cathode is synthesized without impurities phase by partially substituting Ni and Fe into the Mn sites. The partial substitution results in a smoothing of the electrochemical charge/discharge profiles and thus greatly improves the battery performance. The P2‐type Na_0.55[Ni_0.1Fe_0.1Mn_0.8]O₂ cathode delivers an extremely high discharge capacity of 221.5 mAh g^?1 with a high average potential of ≈2.9 V (vs Na/Na⁺) for SIBs. In addition, the fast Na‐ion transport in the P2‐type Na_0.55[Ni_0.1Fe_0.1Mn_0.8]O₂ cathode structure enables good power capability with an extremely high current density of 2400 mA g^?1 (full charge/discharge in 12 min) and long‐term cycling stability with ≈80% capacity retention after 500 cycles at 600 mA g^?1. A combination of electrochemical profiles, in operando synchrotron X‐ray diffraction analysis, and first‐principles calculations are used to understand the overall Na storage mechanism of P2‐type Na_0.55[Ni_0.1Fe_0.1Mn_0.8]O₂.     

Effect of One Morning Meal and a Bolus of Dexamethasone on 24‐Hour Variation of Serum Leptin Levels in Humans

Objective: We have previously shown that morning administration of dexamethasone in combination with food induces a doubling of serum leptin levels starting at 7 hours after dexamethasone administration, with a maximum effect at 10 hours, the latest time point that we have studied. However, dexamethasone given in the absence of food had no effect on serum leptin at 10 hours. The present experiment was undertaken to determine the duration of the effect of dexamethasone on 24‐hour serum leptin under fasted and fed conditions in humans. Research Methods and Procedures: Six healthy non‐obese male volunteers were studied under the following four conditions: 1) dexamethasone (2 mg intravenously, given at 0900 hours) with fasting; 2) dexamethasone with food (1700 kcal, 55% carbohydrate, 15% protein, and 30% fat, given in one meal 2 hours after dexamethasone administration at 1100 hours); 3) saline with food (same meal); 4) saline with fasting. Serum leptin, glucose, insulin, and cortisol were monitored every 30 minutes for 24 hours. Results: 1) Under the fasting condition, dexamethasone increased leptin nocturnal secretion between 2100 and 2400 hours. 2) A single meal (1700 kcal) at 1100 hours increased nocturnal leptin secretion when compared with the fasting condition. The peak increase of leptin was 123% over baseline between 2100 and 2400 hours, 10 to 14 hours after the meal. 3) In the fed + dexamethasone condition, leptin levels increased from baseline starting 8 hours after dexamethasone injection, reached a maximum increase of 260% between 2100 and 2400 hours, then decreased thereafter, remaining elevated compared to baseline for 16 hours. There was a correlation between 24‐hour leptin secretion and insulin secretion after a single morning meal. Discussion: A single bolus of dexamethasone, given before a single large meal, produces a delayed (6‐hour) but long‐lasting increase in serum leptin (over 16 hours). Under fasted conditions, dexamethasone does not increase daytime leptin but does increase leptin during the night.     

Impacts of “supermoon” events on the physiology of a wild bird

The position of the Moon in relation to the Earth and the Sun gives rise to several predictable cycles, and natural changes in nighttime light intensity are known to cause alterations to physiological processes and behaviors in many animals. The limited research undertaken to date on the physiological responses of animals to the lunar illumination has exclusively focused on the synodic lunar cycle (full moon to full moon, or moon phase) but the moon's orbit—its distance from the Earth—may also be relevant. Every month, the moon moves from apogee, its most distant point from Earth—and then to perigee, its closest point to Earth. Here, we studied wild barnacle geese (Branta leucopsis) to investigate the influence of multiple interacting lunar cycles on the physiology of diurnally active animals. Our study, which uses biologging technology to continually monitor body temperature and heart rate for an entire annual cycle, asks whether there is evidence for a physiological response to natural cycles in lunar brightness in wild birds, particularly “supermoon” phenomena, where perigee coincides with a full moon. There was a three‐way interaction between lunar phase, lunar distance, and cloud cover as predictors of nighttime mean body temperature, such that body temperature was highest on clear nights when the full moon coincided with perigee moon. Our study is the first to report the physiological responses of wild birds to “supermoon” events; the wild geese responded to the combination of two independent lunar cycles, by significantly increasing their body temperature at night. That wild birds respond to natural fluctuations in nighttime ambient light levels support the documented responses of many species to anthropogenic sources of artificial light, that birds seem unable to override. As most biological systems are arguably organized foremost by light, this suggests that any interactions between lunar cycles and local weather conditions could have significant impacts on the energy budgets of birds.     

Medium‐Chain Triglycerides Increase Energy Expenditure and Decrease Adiposity in Overweight Men

Objective: The objectives of this study were to compare the effects of diets rich in medium‐chain triglycerides (MCTs) or long‐chain triglycerides (LCTs) on body composition, energy expenditure, substrate oxidation, subjective appetite, and ad libitum energy intake in overweight men. Research Methods and Procedures: Twenty‐four healthy, overweight men with body mass indexes between 25 and 31 kg/m² consumed diets rich in MCT or LCT for 28 days each in a crossover randomized controlled trial. At baseline and after 4 weeks of each dietary intervention, energy expenditure was measured using indirect calorimetry, and body composition was analyzed using magnetic resonance imaging. Results: Upper body adipose tissue (AT) decreased to a greater extent (p < 0.05) with functional oil (FctO) compared with olive oil (OL) consumption (?0.67 ± 0.26 kg and ?0.02 ± 0.19 kg, respectively). There was a trend toward greater loss of whole‐body subcutaneous AT volume (p = 0.087) with FctO compared with OL consumption. Average energy expenditure was 0.04 ± 0.02 kcal/min greater (p < 0.05) on day 2 and 0.03 ± 0.02 kcal/min (not significant) on day 28 with FctO compared with OL consumption. Similarly, average fat oxidation was greater (p = 0.052) with FctO compared with OL intake on day 2 but not day 28. Discussion: Consumption of a diet rich in MCTs results in greater loss of AT compared with LCTs, perhaps due to increased energy expenditure and fat oxidation observed with MCT intake. Thus, MCTs may be considered as agents that aid in the prevention of obesity or potentially stimulate weight loss.