Abstract Winter energy management in small passerines living year-round in boreal or alpine areas presumably results in strong selective pressure since they need to find food, at a time when natural resources diminish and become less available, and energy requirements increase dramatically. In this thesis energy management during the non-breeding season was studied in three species of tits (Parus spp.), from three different populations: Coll de Pal (Spanish Pyrenees), Lund (Southern Sweden) and Oulu (Northern Finland). Energy management strategies vary significantly between species and among populations and individuals of the same species. Such differences may depend on several environmental factors, food predictability and individual characteristics. Birds from the studied populations appear to react to energetic challenges on a short-term basis and in a highly flexible way. The coal tit (Parus ater) in Coll de Pal and the willow tit (Parus montanus) in Oulu, both hoarding species, relied mostly on short-term management of energy for winter survival. Social and residence status appeared to be the most important factors in determining the level of energy reserves, underlining the importance of food predictability for energy management in wintering tits. Further studies were carried out on two distinct populations of great tit (Parus major) exposed to different winter hardiness. Birds from both populations increased their resting metabolic rate (MR) with experimentally decreasing ambient temperatures. Birds from Oulu maintained higher expenditures than birds from Lund in all cases, but also experienced higher energetic cost of thermoregulation at the lowest temperatures. The differences probably did not arise from a differential insulation capacity between populations, despite the differences in plumage structure found, but from a differential metabolic acclimatization. Birds from Lund probably became hypothermic at the lowest temperatures, which may have exceeded the levels they were acclimatized for. The observed differences in basal MR in laboratory conditions were consistent in wild birds throughout the non-breeding season. Birds from both populations experienced similar patterns of variation in basal MR, with expenditures increasing with mass but decreasing with day length, size and age. Great tits modulate their energy expenditure in a flexible way as a means for surviving the non-breeding season. Further, despite such flexibility, populations appear to be locally adapted for such metabolic acclimatization. These results may have important implications on their life-history and distribution. Winter acclimatization appears to be a complex set of entangled strategies that are based on a metabolic adjustment to cope with changing energy requirements. Other mechanisms that apparently play a secondary role, for example the long term management of reserves through fattening or hoarding, or conserving heat through hypothermia and by developing a better insulative plumage, are certainly important emergency strategies that in natural conditions may explain how some populations can endure winter conditions.

Neonicotinoids are primarily used in agriculture where they are applied as seed coatings, foliar sprays, and soil drenches or through drip irrigation. In urban areas neonicotinoids are used in home garden products and tree treatments. The maximum foraging ranges of honey bees are usually 10 – 15 km (median distances are 1 – 6 km) from the hive. Hence bee exposure to neonicotinoids is dependent upon the land use type within limited foraging distances from the hive. However, there are virtually no data showing levels of neonicotinoid use in urban areas and few studies have been done to compare urban and agricultural exposure. Several neonicotinoids have shown various toxic effects on pollinators and particularly honey bees. Honey bees have a limited arsenal of detoxification proteins to withstand neonicotinoid exposure, which makes them more sensitive and less able to develop tolerance to these insecticides compared to other insects. Sublethal exposure of honey bees to neonicotinoids can cause behavioral disturbances, orientation difficulties, impairment of social activities, and respiratory pattern changes. These behavioral changes can cause insufficient foraging behavior in honey bees due to the sublethal effect of neonicotinoids, thus putting the colony at risk of food shortage and eventually collapse. My objectives were to (1) develop a highly sensitive and selective, multi-residual analytical method for neonicotinoids in honey bee and pollen samples, (2) investigate the impacts of land use type (agriculture vs. urban) on the exposure of honey bees to neonicotinoid, (3) investigate the sublethal effect of imidacloprid on honey bees’ behavioral performance, and (4) investigate the sublethal effect of field-realistic concentrations of imidacloprid on honey bees’ metabolism at different ambient temperatures.To address my first objective (Chapter 2), I tested three sample cleanup methods (silica SPE, NH2-silica SPE, and Z-Sep SPE) based on solid phase extraction (SPE), which were investigated for determination of neonicotinoid insecticides and selected metabolites in honey bee and pollen samples by LC-MS/MS. Samples were extracted by hexane and ethyl acetate and then cleaned up with a SPE cartridge packed with silica gel, which showed a better cleanup efficiency compared to the aminopropyl silica SPE and zirconium-based sorbents method. Matrix effects of the three cleanup methods were evaluated and compared. Silica gel showed the highest analyte recoveries and method detection limit for this method were 2.0 to 9.1 μg/kg for honey bees and 2.4 to 4.7 μg/kg for pollen. Recovery studies were performed at three spiking levels (10, 60, and 120 μg/kg) and ranged from 78 to 140% with RSDs between 3 to 18% in honey bees and 83 to 124% with RSDs between 3 to 17% in pollen. The silica gel SPE cleanup method was then applied using honey bee and pollen samples that were collected from different apiaries. To address my second objective (Chapter 3), I analyzed honey bee and beebread (pollen) samples from apiaries in agricultural, developed, and undeveloped areas that were collected during two years in Virginia to assess if landscape type or county pesticide use were predictive of honey bee colony exposure to neonicotinoid insecticides. Trace concentrations of the neonicotinoid imidacloprid were detected in honey bees (3 out of 84 samples, 2.02 – 3.97 ng/g), while higher levels were detected in beebread (5 out of 84 samples, 4.68 – 11.5 ng/g) and pollen (3 out of 5 pollen trap samples, 7.86 – 12.6 ng/g). Imidacloprid was only detected in samples collected during July and August and were not detected in honey bees from hives where neonicotinoids were detected in pollen or beebread. Number of hives sampled at a site, county pesticide use, and landscape characteristics were not predictive of neonicotinoid detections in honey bees or beebread (all P>0.05). Because of the low detection rates, field surveys may underestimate honey bee exposure to field realistic levels of pesticides or the risk of exposure in different landscapes. Undetectably low levels of exposure or high levels of exposure that go undetected raise questions with regard to potential threats to honey bees and other pollinators. To address my third objective (Chapter 4), I investigated the effects of sub-lethal concentrations of imidacloprid on late fall forager honey bees’ behavior by accessing their activity levels and walking performance after being fed ad libitum with six different concentrations (2 – 125 μg/kg) of imidacloprid-dosed syrup for up to 48 hours in laboratory. Honey bee activity levels and motivation to move after being released into a UV light illuminated tunnel decreased significantly as dosages of neonicotinoid in their diet increased. However, their walking speeds were not significantly affected by imidacloprid. The behavioral changes I observed in honey bees chronically exposed to neonicotinoid via diet could negatively affect individual honey bee performance of their hive duties and consequently, colony survival during late fall and winter. To address my fourth objective (Chapter 5), I measured honey bee (Apis mellifera) foragers’ CO2 production rates at different temperatures (25, 30, or 35°C) after they consumed syrup dosed with a field realistic (5 μg/L) or high (20 μg/L) concentration of a neonicotinoid insecticide (i.e. imidacloprid) for 48h. We found that imidacloprid exposure significantly disrupted honey bees’ non-flight metabolic rates and there was a significant interaction between imidacloprid dosage and ambient temperature. Honey bee foragers dosed with 5 μg/L imidacloprid displayed higher average metabolic rates and those dosed with 20 μg/L imidacloprid displayed similar average metabolic rates compared to the corresponding control group across all temperatures. Exposure to field realistic concentrations of neonicotinoid may have a higher energetic cost for honey bees at 25℃ than at higher ambient temperatures. Disrupted energy costs in honey bees fed imidacloprid might be due to the thermoregulation, nerve excitation, or detoxification processes. Metabolic rate changes caused by pesticide exposure could result in less available energy for honey bees to perform hive duties and forage, which could negatively affect colony health.

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Mole-rats are placental mammals which are perfectly adapted to subterranean life. In this thesis I present novel findings on working metabolism and thermoregulatory physiology of mole-rats. These animals cope with low availability of food and have thus employed multiple strategies how to conserve energy and/or use it more effectively. Among other adaptations this resulted in lower resting body temperature, tolerance to increase in body temperature during exercise or while at rest, surprisingly efficient cooling while digging and precise diurnal and seasonal timing of activity with regards to environmental conditions. My focus in this work is on the digging metabolic rate and thermoregulation of social Fukomys mechowii and solitary Heliophobius argenteocinereus in soft and hard substrate, thermoregulatory abilities of Fukomys darlingi, seasonal changes of activity in free living Heliophobius argenteocinereus measured as daily energy expenditure and, finally, energetic consequences of the daily activity patterns of Fukomys anselli.

This study analyzed the acute effect of water consumption on resting metabolic rate (RMR). It was hypothesized that water would have a small, nonclinically significant effect on RMR. Men and women ages 18–40 years participated in a crossover study in which each participant received a No Water and Water condition (order determined randomly) with a 7-day washout period between each condition. Both conditions began with visual analog scales to gauge hunger and thirst levels, urine spectrometry to quantify hydration status, and height and weight measurements. The No Water condition consisted of a 30-minute rest period followed by 45 minutes of RMR testing. The Water condition was identical except for the administration of 500 ml of purified water at 3 °C 10 minutes prior to the beginning of the RMR measurement. Resting metabolic rate testing was done via indirect calorimetry. There was not a condition-by-time difference in 24-hour resting energy expenditure, oxygen consumption, or metabolic equivalents when including all data points and controlling for nonlinearity (ps > 0.0682). There was a significant difference in respiratory quotient (RQ) (F = 13.73; p = 0.0006) with the No Water condition showing a slightly higher RQ than the Water condition. The nonlinear pattern was primarily driven by the first several minutes of testing. Accordingly, we completed analyses without the first 5 minutes of data. The results persisted; that is, there was no condition-by-time effect in 24-hour resting energy expenditure, oxygen consumption, or metabolic equivalents (ps > 0.2435). Further, the RQ remained significantly different (F = 10.57; ps > 0.0023); however, it was slightly higher in the Water condition. This study did not support our hypothesis that consumption of 500 ml of water would have a measurable effect on RMR and fuel utilization compared to not consuming water. Rather, this study replicates other studies that suggest there is not an acute measurable effect of water consumption on RMR. Nevertheless, one positive application of these findings is that water may be a suitable control in RMR studies. In addition, these results should not discourage overall water consumption for healthy functioning. Further, consumption of water-rich foods over time could be an effective strategy for weight management (as shown in other studies). Future studies could attempt to determine if larger volumes of water or different temperatures of water have an effect on RMR.

Obesity is a growing problem globally. Currently 2.3 billion adults are overweight, and this number is rising. The most common method for weight loss is calorie counting, in which to lose weight a person should be in a calorie deficit. Basal Metabolic Rate accounts for the majority of calories a person burns in a day and it is therefore a major contributor to accurate calorie counting. This paper uses a Dynamic Bayesian Network to estimate Basal Metabolic Rate (BMR) for a sample of 219 individuals from all Body Mass Index (BMI) categories. The data was collected through the Lifesum app. A comparison of the estimated BMR values was made with the commonly used Harris Benedict equation, finding that food journaling is a sufficient method to estimate BMR. Next day weight prediction was also computed based on the estimated BMR. The results stated that the Harris Benedict equation produced more accurate predictions than the metabolic model proposed, therefore more work is necessary to find a model that accurately estimates BMR.

Background: Cerebral Palsy is usually divided into three subgroups: ataxic, spastic and dyskinetic, where children and adolescents can, because of misestimation in nutrition and energy intake, suffer from weight problems. Aim: To compare calculations with equations with the individual's measured RMR in the subgroups, to see if any equation is more suitable. This could be used as a tool to calculate the resting metabolism at times when it is not possible to perform clinical measurements. Method: The RMR has been measured in 37 children and adolescents aged 3-15 years through indirect respiratory calorimetry. Those values have been compared with calculations from five equations. The results were then analyzed in order to find if any equation is better to apply for calculating resting metabolism for each subgroup. Results: The ataxic group was overestimated by 56.5% of the calculated values. WHO/FAO/UNU’s equation indicates a significantly strong correlation between the measured and calculated values (r=0.85, p<0.05). The spastic group was underestimated by 53.3%. There is significance for all equations, however it is a relatively low correlation (r=0.63–0.66, p=0.02–0.03). The dyskinetic group was underestimated by 95%. There was no significant association between clinically measured values and the calculated resting metabolism (r=0.21–0.45, p=0.26–0.61). Conclusion: The equations are not reliable for calculation of energy need for all subgroups. There is a substantial risk of over- and underestimation, therefore awareness of the equations insufficiency is needed. Studies should be performed with additional basic data, and with more equations. Especially equations including further variables that involves the body composition. / Bakgrund: Cerebral Pares brukar delas in i undergrupper: ataktisk, spastisk och dyskinetisk, där barn och ungdomar kan, beroende på felskattningar av näringsintag och energiberäkning, lida av över- eller undervikt. Syfte: Att jämföra uträkningar med ekvationer med individernas uppmätta vilometabolism i de tre undergrupperna, för att se om någon ekvation lämpar sig bättre. Detta skulle kunna ge ett verktyg för att kunna räkna ut vilometabolismen vid de tillfällen då det inte är möjligt att utföra kliniska mätningar. Metod: Mätningar av vilometabolismen har utförts på 37 barn och ungdomar i åldern 3-15 år genom indirekt respiratorisk kalorimetri. Värdena har jämförts med uträkningar från fem ekvationer. Resultatet har sedan analyserats, för att hitta någon ekvation som är bättre lämpad för att räkna ut vilometabolismen, för respektive undergrupp. Resultat: Den ataktiska gruppen överskattades i 56,5% av uträkningarna av vilometabolism. WHO/FAO/UNUs ekvation påvisar ett signifikant starkt samband mellan det uppmätta och uträknade värdena (r=0,85, p<0,05). Den spastiska gruppen underskattades 53,3% av de uträknade värdena. Det föreligger signifikans för alla ekvationer, dock ett relativt lågt samband (r=0,63–0,66, p=0,02–0,03). Den dyskinetiska gruppen underskattades i 95 %. Det förelåg inget signifikant samband mellan kliniskt uppmätt och uträknad vilometabolism (r=0,21–0,45, p=0,26–0,61). Slutsats: Ekvationerna är inte tillförlitliga för uträkning av energibehov för alla undergrupper. Risk för över- och underskattning är överhängande, och en ökad medvetenhet om ekvationernas ofullständighet måste belysas. Studier bör göras med större underlag och med fler ekvationer. Framförallt ekvationer med fler variabler som tar hänsyn till kroppssammansättning.