Energetic costs of activity by lizards in the field

The doubly labeled water (DLW) technique and indirect calorimetry enable measurement of an animal’s daily energy expenditure (DEE, kJ/day), resting metabolic rate (RMR, kJ/d), sustained metabolic scope (SusMS), body fat content (BF, %) as well as water turnover (WTO, ml/day), and water economy index (ml/kJ). Small mammals have been the primary focus of many of the DLW studies to date. From large multi-species analyses of the energetics and water flux of aboveground small mammals, well-defined trends have been observed. These trends mainly refer to an adaptive advantage for lower RMR, DEE, SusMS, WTO and WEI in more ariddwelling animals to increase water and energy savings under low and unpredictable resource availability. The study of the subterranean rodent family Bathyergidae (African mole-rats) has been of particular interest with regards to field metabolic rate and metabolic studies. Although a great deal of research has been conducted on the Bathyergidae, a complete overview and multi-species analysis of the energetics and water flux of this family is lacking. Consequently, we assessed DEE, RMR, SusMS, BF, WTO and WEI across several different species of bathyergids from various climatic regions, and compared these to the established patterns of energetics and water flux for aboveground rodents. There was notable variation across the Bathyergidae inhabiting areas with different aridities, often contrary to the variations observed in above-ground species. These include increased DEE and WEI in arid-dwelling bathyergid species. While the climate was not a clear factor when predicting the SusMS of a bathyergid species, rather the degree of group living was a strong driver of SusMS, with solitary species possessing the highest SusMS compared to the socially living species. We conclude that the constraints of the underground lifestyle and the consequent spectrum of social behaviors possessed by the family Bathyergidae are most likely to be more crucial to their energetics and water flux than their habitat; however other important unstudied factors may still be at play. More so, this study provides evidence that often unreported parameters, measured through use of the DLW technique (such as BF and WEI) can enable species to be identified that might be at particular risk to climate change.

A seasonal difference of daily energy expenditure in a free-living subterranean rodent, the silvery mole-rat ( Heliophobius argenteocinereus; Bathyergidae)

Time-averaged sustained metabolic rates (SusMRs) of humans and wild animals have been observed not to exceed about seven times basal metabolic rate (BMR), which suggests a possible ceiling on sustained metabolic scope. We tested experimentally for such a ceiling by subtracting or adding pups to vary the litter size of lactating mother mice between five and 26 pups. Mothers could regularly wean 14pups but not more (natural litter size is 8-10). Although food intake at peak lactation increased to as much as 3.4 times virgin values and increased with litter size, digestive efficiency remained constant The mass of the small intestine and of other gut compartments increased up to severalfold at peak lactation, and as a consequence so did the intestine's brush-border uptake capacities for glucose and for proline. Time-averaged sustained metabolic rate at peak lactation reached 7.2 times BMR; this ratio is evidently close to a ceiling on sustained metabolic scope. Estimates of intestinal nutrient uptake capaciti...

Hummingbirds (family Trochilidae) represent an extreme outcome in vertebrate physiological design and are the only birds capable of sustained hovering. The giant hummingbird (Patagona gigas) is the largest trochilid, with a mass of ~20 g, and is found over an altitudinal range from 0 to 4,500 m above sea level. We report here measurements of daily, basal, and hovering rates of oxygen consumption in the giant hummingbird; compare these values with data from smaller hummingbirds; and assess overall metabolic and allometric limits to trochilid body size. The sustained metabolic scope (i.e., the ratio of daily energy expenditure to basal metabolic rate) in the giant hummingbird is higher than that in smaller hummingbirds but lies below a proposed theoretical maximum value for endotherms. Scaling exponents in the allometric relationships for different modes of energetic expenditure were comparable, suggesting that the giant hummingbird, although a clear outlier in terms of body size, does not obviously deviate from metabolic relationships derived from other trochilid taxa.

ABSTRACTBackgroundFour models are commonly used to adjust for energy intake when estimating the causal effect of a dietary component on an outcome: 1) the “standard model” adjusts for total energy intake, 2) the “energy partition model” adjusts for remaining energy intake, 3) the “nutrient density model” rescales the exposure as a proportion of total energy, and 4) the “residual model” indirectly adjusts for total energy by using a residual. It remains underappreciated that each approach evaluates a different estimand and only partially accounts for confounding by common dietary causes.ObjectivesWe aimed to clarify the implied causal estimand and interpretation of each model and evaluate their performance in reducing dietary confounding.MethodsSemiparametric directed acyclic graphs and Monte Carlo simulations were used to identify the estimands and interpretations implied by each model and explore their performance in the absence or presence of dietary confounding.ResultsThe “standard model” and the mathematically identical “residual model” estimate the average relative causal effect (i.e., a “substitution” effect) but provide biased estimates even in the absence of confounding. The “energy partition model” estimates the total causal effect but only provides unbiased estimates in the absence of confounding or when all other nutrients have equal effects on the outcome. The “nutrient density model” has an obscure interpretation but attempts to estimate the average relative causal effect rescaled as a proportion of total energy. Accurate estimates of both the total and average relative causal effects may instead be derived by simultaneously adjusting for all dietary components, an approach we term the “all-components model.”ConclusionsLack of awareness of the estimand differences and accuracy of the 4 modeling approaches may explain some of the apparent heterogeneity among existing nutritional studies. This raises serious questions regarding the validity of meta-analyses where different estimands have been inappropriately pooled.

This study was conducted to examine the nutrient intake status of cancer survivors. A total of 5224 cancer survivors, 19,926 non-cancer individuals without comorbidities (non-cancer I), and 20,622 non-cancer individuals with comorbidities, matched by age, gender, and recruitment center location were included in the analysis. Generally, the proportion of total energy from carbohydrates was higher and the proportion from fat was lower in cancer survivors. The odds ratios (ORs) for total energy (OR = 0.92, 95% confidence interval (CI) = 0.86–0.99), proportion of total energy from fat (OR = 0.54, 95% CI = 0.35–0.83), and protein (OR = 0.85, 95% CI = 0.79–0.90) were significantly lower, and the OR for the proportion of total energy from carbohydrates was higher (OR = 1.21, 95% CI = 1.10–1.33) in the cancer survivors than in non-cancer I. Additionally, the cancer survivors’ protein, vitamin B1, vitamin B2, niacin, and phosphorus intakes were lower, whereas their vitamin C intake was higher. When divided by cancer type, the ORs for the carbohydrate percentages were significantly higher in the colon and breast cancer survivors, whereas protein intake was lower in gastric, breast, and cervical cancer survivors. The nutrient intake patterns in Asian cancer survivors are poor, with higher carbohydrate and lower fat and protein intakes.

Criteria that are important to determine the ability of agencies in managing households in the agency can be seen from its financial position. The financial position can be seen from the Budget Realization Report (LRA) that determines the amount of agency expenditure to finance all activities in each budget year. The purpose of this research is to know the Control of Budget of Forestry Service of East Kalimantan Province in 2016. Based on the results of analysis and discussion on research, then the conclusion Based on the results of analysis and discussion on research, the conclusions obtained are as follows: 1. Viewed Ratio of Growth Spending Budget Control of East Kalimantan Provincial Forestry Office 2016 Efficiency due to Expenditure in 2016 has increased. 2. Viewed Operating Expenditure Ratio Against Total Expenditure Budget Control of East Kalimantan Provincial Forestry Office 2016 Efficiency due to Actual Expenditure of Operations in 2016 decreased. 3. Capital Expenditure Ratio to Total Expenditure Budget Control of East Kalimantan Provincial Forestry Office 2016 Efficiency due to Actual Expenditure of Operations in 2016 decreased. 4. Direct Ratio of Direct Expenditure and Indirect Expenditure Budget Control of East Kalimantan Provincial Forestry Office 2016 Unstable due to Expenditure of Operations Expenditure in 2016 has increased. 5. Viewed Ratio of Efficiency of Expenditure Budget Control of East Kalimantan Provincial Forestry Office 2016 Enough Efficiency due to Realization of Expenditure in 2016 less than Budget. Based on the above conclusions of the East Kalimantan Provincial Forestry Service's Budget Control. It is reviewed from the Growth Ratio of Expenditure, the Ratio of Expenditure on Total Expenditure, the Ratio of Capital Expenditure to Total Expenditure, the Ratio of Direct Expenditure and Indirect Expenditure, the Efficient Easier Expense Ratio of 2016, Accepted

SummaryA comparison was made of the daily energy expenditure (DEE), resting metabolic rate (RMR) and water turnover (WTO) of two populations of Common Spiny MiceAcomys cahirinusfrom north‐ and south‐facing slopes (NFS and SFS) of the same valley, which represented ‘Mediterranean’ and ‘desert’ habitats, respectively.An examination was made as to whether these physiological characteristics differed between mice that had been in the laboratory (outdoor conditions) for 2 months compared with mice captured from the field.Mice from the field had greater RMR values than mice in the laboratory and NFS mice had greater RMR values than SFS mice. In the field, NFS individuals had greater DEE values than SFS individuals. Mass‐specific RMR values of SFS mice were 20% less than the allometrically predicted value, whereas those of NFS were not. WTO and sustained metabolic scope (DEE/RMR) were lower in the field than in the laboratory.The results indicate that physiological capabilities are phenotypically plastic, as differences exist between the field and laboratory and between NFS and SFS mice. Furthermore, they highlight the importance of using field studies for understanding the link between energetics and physiological adjustment to environmental conditions.

Differential energy costs of winter acclimatized common spiny mice Acomys cahirinus from two adjacent habitats

Sustained metabolic rates (SusMR) are time-averaged metabolic rates that are measured in free-ranging animals maintaining constant body mass over periods long enough that metabolism is fueled by food intake rather than by transient depletion of energy reserves. Many authors have suggested that SusMR of various wild animal species are only a few times resting (basal or standard) metabolic rates (RMR). We test this conclusion by analyzing all 37 species (humans, 31 other endothermic vertebrates, and 5 ectothermic vertebrates) for which SusMR and RMR had both been measured. For all species, the ratio of SusMR to RMR, which we term sustained metabolic scope, is less than 7; most values fall between 1.5 and 5. Some of these values, such as those for Tour de France cyclists and breeding birds, are surely close to sustainable metabolic ceilings for the species studied. That is, metabolic rates higher than 7 times RMR apparently cannot be sustained indefinitely. These observations pose several questions: whether the proximate physiological causes of metabolic ceilings reside in the digestive tract's ability to process food or in each tissue's metabolic capacity; whether ceiling values are independent of the mode of energy expenditure; whether ceilings are set by single limiting physiological capacities or by coadjusted clusters of capacities (symmorphosis); what the ultimate evolutionary causes of metabolic ceilings are; and how metabolic ceilings may limit animals' reproductive effort, foraging behavior, and geographic distribution.

We explored how morphological and physiological traits associated with energy expenditure over long periods of cold exposure would be integrated in a potential response to natural selection in a wild mammal, Phyllotis danwini. In particular, we studied sustained energy expenditure (SusMR), the rate of expenditure fueled by concurrent energy intake, basal metabolic rate (BMR), and sustained metabolic scope (SusMS = SusMR/BMR), a measure of the reserve for sustained work. We included the masses of different central processing organs as an underlying factor that could have a mechanistic link with whole animal traits. Only the liver had heritability statistically different from zero (0.73). Physiological and morphological traits had high levels of specific environmental variance (average 70%) and postnatal common environmental variance (average 30%) which could explain the low heritabilities estimates. Our results, (1) are in accordance with previous studies in mammals that report low heritabilities for metabolic traits (SusMR, BMR, SusMS), (2) but not completely with previous ones that report high heritabilities for morphological traits (masses of central organs), and (3) provide important evidence of the relevance of postnatal common environmental variance to sustained energy expenditure.

We measured the ontogeny of growth rate, food intake, metabolic rates, organ masses, and intestinal nutrient transporter and hydrolase activities in a wild bird for comparison with previous measurements of the same quantities in four domesticated or laboratory animals. Analysis of covariance with body mass as a covariate showed that body mass accounted for most of the age-related variation in all variables, but that age itself still had a significant effect on most variables. Among organs studied, the ceca exhibited the greatest mass increase with age. Energy intake and resting and basal metabolic rates increased with age, but digestive efficiency, cost of growth, and sustained metabolic scope were independent of age. Although intestinal brush-border glucose and proline uptakes and sucrase activity declined with age, the corresponding capacities increased with age because of compensating increases in intestinal mass. Intestinal passive permeability to glucose was undetectably low. Unlike the four domesticated animals studied to date, jungle fowl possess no intestinal reserve capacities (excesses of capacity over dietary nutrient intake). Cecal absorption may contribute significantly to glucose uptake capacity with increasing age.

Is long-term sustained metabolic rate (SusMR) subject to a ceiling value? If so, what physiological or evolutionary factors impose that ceiling, and is the ceiling value independent of the type of energy stress? We determined food intake and daily digestible energy intake (DEI) as measures of SusMR, and resting metabolic rate (RMR), in mice that were energy stressed by being maintained at cold ambient temperatures. We compared these values with those from previous studies of mice that were energy stressed by peak lactation. We also measured intestinal brush-border nutrient uptakes, body lean and fat masses, and masses of the small intestine, heart, kidneys, and liver. Even with ad lib. quantities of a high-fat diet available, mice could not survive at temperatures below -15° C. Body mass declined at low temperatures because of depletion of body fat reserves. Food intake increased 2.5-fold, RMR 1.5-fold, and masses of the small intestine, heart, and kidneys by 30%-70% with a decrease in temperature from 23° C to -15° C. Intestinal hypertrophy served to restore the reserve capacity of intestinal nutrient transporters that would otherwise have been swamped by the increased food intake. The values reached by sustained metabolic scope (SusMR/RMR), food intake, and intestinal mass were still considerably below those of lactating mice, even though mice at temperatures below -15° C died in the presence of excess food. Thus, intestinal capacity was not the ultimate reason for an inability to survive at lower temperatures. Analysis of individual variation showed that those mice with unusually high food intake, DEI, or RMR tended to have unusually large hearts, kidneys, and intestines. Those organs are essentialfor high energy budgets (reflected in high DEIs), but they also incur large maintenance costs themselves (reflected in high RMRs).

Purpose: The aim of the present study was to identify the contribution of nutrition, physical activity (PA), and total energy intake and expenditure on body weight and composition in adolescents. Methods: Body composition, PA, and dietary intakes from 904 Greek adolescents (446 boys and 458 girls; Age: 14.6 ± 1.5 yrs), were evaluated. All participants were assigned into three groups according to their age-sex adjusted Fat Mass Index: (A) Normal weight (N; N = 503), (B) Overweight (OW; N = 253), and (C) Obese (O; N = 148). Results: Significant differences were found for body weight and composition, basal metabolic rate (BMR) expressed per kg of body mass (normal weight children exhibited the highest values), physical-total energy expenditure, and energy balances between the groups (η2: 0.138 to 0.657; p < .05). In contrast, no differences were found for macronutrients’ and total energy intakes, food consumption and quality (η2: 0.002 to 0.099; p > .05) between the three examined groups. Strong, negative correlations were observed between body weight, body fat percentage, PA, and total energy expenditure (r: −0.311 to −0.810; p < .001). Lower, negative correlations were found between body weight, body fat percentage, and macronutrients’ daily intakes (r:-0.235 to −0.432; p < .05). BMR and total energy expenditure had strong, negative relative strengths for the determination of body weight and fat percentage. Conclusions: In conclusion, it seems that BMR, PA, and total daily energy expenditure expressed per body weight and not the nutritional and total energy intakes, were the primary determinant parameters of body composition and weight in adolescents.

The revised guidelines from the Department of Health (DoH) in the UK state that mean population intakes of free sugars should be below 5% of the total energy (TE) consumption of the British population. However, very few studies have assessed the impact of this recommendation on diet quality in the UK. We explored the dietary patterns and intakes of micronutrients of British adolescents with low intakes of non-milk extrinsic sugars (NMES) (similar to free sugars but not equal, with slight differences in the categorisation of fruit sugars from dried, stewed or canned fruit and smoothies), using the National Diet and Nutrition Survey Rolling Programme, years 1–8 (NDNS RP). The sample included 2587 adolescents aged 11–18 years. Four percent (112) of adolescents reported consuming 5% or lower NMES as a proportion of TE. The odds of being categorised as a low-sugar consumer in adolescents (≤5% TE from NMES) were significantly lower with higher intakes of sweetened drinks, fruit juice, cakes, biscuits, sugar and sweet spreads, chocolate confectionery and sugar confectionery, and significantly higher with higher intakes of pasta and rice, wholemeal and brown bread, and fish. Across the five categories of NMES intakes, micronutrient intakes were lowest for those consuming either ≤5% TE or more than 20% TE from NMES, and optimal for those consuming between 10–15% of energy from NMES. These findings confirm the difficulties of meeting the free sugars recommended intake for adolescents. Care needs to be taken to ensure that an adequate consumption of micronutrients is achieved in those adhering to the revised guidelines on free sugars.