Effects of mass and body composition on fasting fuel utilisation in grey seal pups (Halichoerus grypus Fabricius): an experimental study using supplementary feeding

This study used supplementary feeding to test the hypothesis that fuel partitioning during the postweaning fast in grey seal pups is affected by size and composition of energy reserves at weaning, and by extra provisioning. Mass and body composition changes were measured during suckling and fasting to investigate the effect of natural differences in energy reserves at weaning on subsequent allocation of fat and protein to energy use. We fed seven pups for 5 days after weaning, to investigate the effect of increased fuel availability, and particularly protein, on fuel utilisation. After correcting for protein used during the moult, the proportional contribution of fat was 86–99% of total energy use. Pups with greater energy reserves, i.e. those that were heavier and fatter at weaning, had higher rates of fat and energy use. There was no significant relationship between adiposity at weaning and proportional contribution of fat to energy use, perhaps due to a limited sample size or range of body masses and adiposity. Supplemented individuals used energy, specifically fat, much faster and utilised proportionally less of their endogenous protein by departure than non-supplemented individuals. Fat metabolism contributed a similar percentage to daily energy use in both groups. These findings show that pups spare protein, even when energy use is dramatically increased. Pups that receive greater maternal provisioning and lay down more protein may have increased survival chances at sea. This study highlights the importance of protein reserves in first year survival of grey seal pups.

Energy efficient measures to reduce electrical energy use in commercial buildings in New York City

GEA Consulting Engineers, acting as the design engineers, was hired by the owner, East Village 207 Residential LLC2 for energy modeling for compliance with LEED NC V3 -- This report details the results of the energy simulation done with the 100% construction documents -- This report only refers to entities within the LEED3 project boundary -- The project consists of a new eight-story high-end residential condominium building with 81 units, as shown in illustration 1, and approximately 117,905 GSF, equivalent to 10,953.73 m2, is located at 211 E 13th Street in New York, NY -- The residential portion of the building will function 24-7 -- The design goal is to utilize energy efficient measures to reduce electrical energy use and aims to achieve LEED certification -- LEED EA Credit 14 requires a building to demonstrate a percentage improvement in the proposed building performance compared with the baseline building -- The Credit rewards 1 point for achieving 12% reduction in energy costs -- Additionally, the Credit rewards another point for each subsequent reduction of 2% in the building’s energy cost

Energy systems analysis of transboundary river basins in a nexus approach: the Sava river basin study case

Resource management policies are frequently designed and planned to target specific needs of particular sectors, without taking into account the interests of other sectors who share the same resources. In a climate of resource depletion, population growth, increase in energy demand and climate change awareness, it is of great importance to promote the assessment of intersectoral linkages and, by doing so, understand their effects and implications. This need is further augmented when common use of resources might not be solely relevant at national level, but also when the distribution of resources ranges over different nations. This dissertation focuses on the study of the energy systems of five south eastern European countries, which share the Sava River Basin, using a water-food(agriculture)-energy nexus approach. In the case of the electricity generation sector, the use of water is essential for the integrity of the energy systems, as the electricity production in the riparian countries relies on two major technologies dependent on water resources: hydro and thermal power plants. For example, in 2012, an average of 37% of the electricity production in the SRB countries was generated by hydropower and 61% in thermal power plants. Focusing on the SRB, in terms of existing installed capacities, the basin accommodates close to a tenth of all hydropower capacity while providing water for cooling to 42% of the net capacity of thermal power currently in operation in the basin. This energy-oriented nexus study explores the dependency on the basin’s water resources of the energy systems in the region for the period between 2015 and 2030. To do so, a multi-country electricity model was developed to provide a quantification ground to the analysis, using the open-source software modelling tool OSeMOSYS. Three main areas are subject to analysis: first, the impact of energy efficiency and renewable energy strategies in the electricity generation mix; secondly, the potential impacts of climate change under a moderate climate change projection scenario; and finally, deriving from the latter point, the cumulative impact of an increase in water demand in the agriculture sector, for irrigation. Additionally, electricity trade dynamics are compared across the different scenarios under scrutiny, as an effort to investigate the implications of the aforementioned factors in the electricity markets in the region.

Role of mitochondrial antioxidant defense systems in fatty acid β-oxidation defects

Mitochondrial fatty acid oxidation (FAO) plays a pivotal role in energy homeostasis, namely during periods of fasting or metabolic stress. FAO defects are a group of inherited metabolic disorders that encompass at least twelve distinct enzyme or transporter deficiencies, and can present with a wide range of clinical symptoms with various degrees of severity. Besides recent advances, many doubts still remain on the degree and characteristics of mitochondrial dysfunction on FAOD and its contribution to the clinical phenotype.

Impact of natural and/or chemical stressors on the freeze-tolerant and euryhaline enchytraeid, Enchytraeus albidus

Rapid climatic changes are taking place in Arctic, subarctic and cold temperate regions, where predictions point to an increase in freeze-thaw events, changes in precipitation, evaporation and salinity patterns. Climate change may therefore result in large impacts in ecosystem functioning and dynamics, especially in the presence of contaminants due to intense anthropogenic activities. Even though multiple stress approaches have received increasing interest in the last decades, the number of such studies is limited. In particular, knowledge on the effect of freezethaw events and salinity fluctuations on ecotoxicology of soil invertebrates is lacking, especially important when considering supralittoral species. Therefore, the aim of this thesis was to investigate the effects of low temperature and salinity fluctuations, singly and in combination with contaminants, in the freeze-tolerant and euryhaline enchytraeid Enchytraeus albidus. The assessment of population level endpoints (survival and reproduction), along with physiological and biochemical parameters such as levels of cryoprotectants, ice/water content, oxidative stress biomarkers, cellular energy allocation, and tissue concentration of chemicals (when applied), provided new and valuable knowledge on the effects of selected physical and chemical stressors in E. albidus, and allowed the understanding of adjustments in the primary response mechanisms that enable worms to maintain homeostasis and survival in harsh environments such as polar and temperate-cold regions. The presence of moderate levels of salinity significantly increased freeze-tolerance (mainly evaluated as survival, cryoprotection and ice fraction) and reproduction of E. albidus. Moreover, it contributed to the readjustments of cryoprotectant levels, restoration of antioxidant levels and changed singnificantly the effect and uptake of chemicals (copper cadmium, carbendazim and 4-nonylphenol). Temperature fluctuations (simulated as daily freeze-thaw cycles, between -2ºC and -4ºC) caused substancial negative effect on survival of worms previsouly exposed to non-lethal concentrations of 4-nonylphenol, as compared with constant freezing (-4ºC) and control temperature (2ºC). The decrease in cryoprotectants, increase in energy consumption and the highest concentration of 4-nonylphenol in the tissues have highlighted the high energy requirements and level of toxicity experienced by worms exposed to the combined effect of contaminants and freezing-thawing events. The findings reported on this thesis demonstrate that natural (physical) and chemical stressors, singly or in combination, may alter the dynamics of E. albidus, affecting not only their survival and reproduction (and consequent presence/distribution) but also their physiological and biochemical adaptations. These alterations may lead to severe consequences for the functioning of the ecosystems along the Arctic, subarctic and cold temperate regions, where they play an important role for decomposition of dead organic matter. This thesis provides a scientific basis for improving the setting of safety factors for natural soil ecosystems, and to underline the integration of similar investigations in ecotoxicology, and eventually in risk assessment of contaminants.

Energy and Antioxidant Responses of Pacific Oyster Exposed to Trace Levels of Pesticides

Here, we assess the physiological effects induced by environmental concentrations of pesticides in Pacific oyster Crassostrea gigas. Oysters were exposed for 14 d to trace levels of metconazole (0.2 and 2 mu g/L), isoproturon (0.1 and 1 mu g/L), or both in a mixture (0.2 and 0.1 mu g/L, respectively). Exposure to trace levels of pesticides had no effect on the filtration rate, growth, and energy reserves of oysters. However, oysters exposed to metconazole and isoproturon showed an overactivation of the sensing-kinase AMP-activated protein kinase alpha (AMPK alpha), a key enzyme involved in energy metabolism and more particularly glycolysis. In the meantime, these exposed oysters showed a decrease in hexokinase and pyruvate kinase activities, whereas 2-DE proteomic revealed that fructose-1,6-bisphosphatase (F-1,6-BP), a key enzyme of gluconeogenesis, was upregulated. Activities of antioxidant enzymes were higher in oysters exposed to the highest pesticide concentrations. Both pesticides enhanced the superoxide dismutase activity of oysters. Isoproturon enhanced catalase activity, and metconazole enhanced peroxiredoxin activity. Overall, our results show that environmental concentrations of metconazole or isoproturon induced subtle changes in the energy and antioxidant metabolisms of oysters.

Influence of applied uniaxial stress upon the ultraviolet absorption bands in KBr and KI

The influence of uniaxial stress upon three types of imperfections occurring in the alkali halide crystal lattice has been investigated. The imperfections are the interstitial atom, the interstitial ion, and the negative ion vacancy. The interstitial atom, or H center, is a paraelastic defect which assumes a preferential crystal orientation in the field of an external mechanical stress. From the results of the reorientation kinetics - studies, it was possible to show that H centers are not stable in the KBr crystal lattice above 2SoK. At temperatures higher than 2SoK, the H centers are transformed into two new paraelastic defects, H(ii) and H(iii), possessing the same optical absorption band as the H center but differing both from the H' center and from each other in their reorientation kinetics. A study of the wavelength dependence of the H, H(ii), and VI (Na+) centers s~owed the 'existence of three similar-polarized transitions for each of these defects. One of these transitions, located at 230 run for all of the defects studied, was determined to be too high in energy to be explained by the simple X2 - level scheme. In addition, a comparison of various properties of the four defects indicates that the last three can be described as perturbed H centers. Dichroism measurements, performed as a function of temperature and wavelengt, h on the 230-nm I band in KBr, showed this band to be a composite of a band at 234 nm due to the I center and a band at 230 nm attributed to the H center. The I center dichroism was isolated and was observed under various experimental conditions. The results of these observations are consistent with a body-centered model for the I center in which the I-center absorption band is attributed to the excitation of a p-like electron on the interstitial Br- ion. Similar measurements were also perfonned on the a band in KI. The a-band dichroism measurements were found to be consistent with an electronic transition from an s-like ground state to a p-like excited state, indicating that the a center is best described as a quasi-molecule.

Immune function, gene expression, blood indices and performance in transition dairy cows affected by diet and inflammation

The transition period is associated with the peak incidence of production problems, metabolic disorders and infectious diseases in dairy cows (Drackley, 1999). During this time the cow’s immune system seems to be weakened; it is apparent that metabolic challenges associated with the onset of lactation are factors capable of affecting immune function. However, the reasons for this state are not entirely clear (Goff, 2006). The negative energy balance associated with parturition leads to extensive mobilization of fatty acids stored in adipose tissue, thus, causing marked elevations in blood non-esterified fatty acids (NEFA) and B-hydroxybutyrate (BHBA) concentrations (Drackley et al., 2001). Prepartal level of dietary energy can potentially affect adipose tissue deposition and, thus, the amount of NEFA released into blood and available for metabolism in liver (Drackley et al., 2005). The current feeding practices for pregnant non-lactating cows has been called into question because increasing amounts of moderate-to-high energy diets (i.e. those more similar to lactation diets in the content of energy) during the last 3 wk postpartum have largely failed to overcome peripartal health problems, excessive body condition loss after calving, or declining fertility (Beever, 2006). Current prepartal feeding practices can lead to elevated intakes of energy, which can increase fat deposition in the viscera and upon parturition lead to compromised liver metabolism (Beever, 2006, Drackley et al., 2005). Our general hypothesis was that overfeeding dietary energy during the dry period, accompanied by the metabolic challenges associated with the onset of lactation would render the cow’s immune function less responsive early postpartum. The chapters in this dissertation evaluated neutrophil function, metabolic and inflammation indices and gene expression affected by the plane of dietary energy prepartum and an early post-partum inflammatory challenge in dairy cows. The diet effect in this experiment was transcendental during the transition period and potentially during the entire lactation. Changes in energy balance were observed and provided a good model to study the challenges associated with the onset of lactation. Overall the LPS model provided a consistent response representing an inflammation incident; however the changes in metabolic indices were sudden and hard to detect in most of the cases during the days following the challenge. In general overfeeding dietary energy during the dry period resulted in a less responsive immune function during the early postpartum. In other words, controlling the dietary energy prepartum has more benefits for the dairy cow during transition.

Ionic composition of endolymph in teleosts: Origin and importance of endolymph alkalinity

Ionic (Na+, K+, Cl-, PO43-, pH), total CO2, total calcium and protein concentrations in the plasma and endolymph of the inner ear were compared in trout Oncorhynchus mykiss and turbot Scophthalmus maximus. In both species, saccular endolymph was characterized by high levels of K+ and total CO2 and in trout by an alkaline pH, The kinetic characteristics of proton secretion across the saccular epithelium of trout were investigated using a titration technique in which isolated saccules were mounted as closed sacs. The rate of proton secretion depends strongly on the pH of the Ringer's solution and secretion stops at a pH below 7.2, Proton secretion is driven by an energy-dependent mechanism involving basolateral ouabain-sensitive Na+/K+ exchangers. Proton secretion was partially inhibited by acetazolamide and completely inhibited in Na+-free Ringer or in the presence of 1 mmol l(-1) amiloride. A cellular model stressing the importance of proton exchange through the saccular epithelium is proposed to explain the regulation of endolymph pH, a crucial factor for the deposition of otolith calcium.

Developing strategies to mitigate the energy consumed by network infrastructures

The energy consumption by ICT (Information and Communication Technology) equipment is rapidly increasing which causes a significant economic and environmental problem. At present, the network infrastructure is becoming a large portion of the energy footprint in ICT. Thus the concept of energy efficient or green networking has been introduced. Now one of the main concerns of network industry is to minimize energy consumption of network infrastructure because of the potential economic benefits, ethical responsibility, and its environmental impact. In this paper, the energy management strategies to reduce the energy consumed by network switches in LAN (Local Area Network) have been developed. According to the lifecycle assessment of network switches, during usage phase, the highest amount of energy consumed. The study considers bandwidth, link load and traffic matrixes as input parameters which have the highest contribution in energy footprint of network switches during usage phase and energy consumption as output. Then with the objective of reducing energy usage of network infrastructure, the feasibility of putting Ethernet switches hibernate or sleep mode was investigated. After that, the network topology was reorganized using clustering method based on the spectral approach for putting network switches to hibernate or switched off mode considering the time and communications among them. Experimental results show the interest of this approach in terms of energy consumption

Effects in ultrafast laser micromachining PMMA-based optical fibre grating

Ultrafast laser owns extreme small beam size and high pulse intensity which enable spatial localised modification either on the surface or in the bulk of materials. Therefore, ultrafast laser has been widely used to micromachine optical fibres to alter optical structures. In order to do the precise control of the micromachining process to achieve the desired structure and modification, investigations on laser parameters control should be carried out to make better understanding of the effects in the laser micromachining process. These responses are important to laser machining, most of which are usually unknown during the process. In this work, we report the real time monitored results of the reflection of PMMA based optical fibre Bragg gratings (POFBGs) during excimer ultraviolet laser micromachining process. Photochemical and thermal effects have been observed during the process. The UV radiation was absorbed by the PMMA material, which consequently induced the modifications in both spatial structure and material properties of the POFBG. The POFBG showed a significant wavelength blue shift during laser micromachining. Part of it attributed to UV absorption converted thermal energy whilst the other did not disappear after POFBG cooling off, which attributed to UV induced photodegradation in POF.

The reality of cross-disciplinary energy research in the United Kingdom:a social science perspective

Cross-disciplinary research is essential in understanding and reducing energy usage, however the reality of this collaboration comes with many challenges. This paper provides an insight into the integration of social science in energy research, drawing on the expertise and first hand experiences of a range of social science researchers (predominantly Early Career Researchers (ECRs)) working on UK cross-disciplinary projects in energy demand. These researchers, participants in a workshop dedicated to understanding the integration of social science in energy research, identified four groups of challenges to successful integration: Differing expectations of the role of social scientists; Working within academia; Feeling like a valued member of the team; and Communicating and comprehension between disciplines. Suggestions of how to negotiate those challenges included: Management and planning; Increasing contact; Sharing experience; and Understanding team roles. The paper offers a definition of ‘success’ in cross-disciplinary energy research from the perspective of social science ECRs, comprising external, internal and personal components. Using the logics of interdisciplinarity, this paper suggests that integration of the social sciences in the projects discussed may be partial at best and highlights a need to recognise the challenges ECRs face, in order to achieve full integration and equality of disciplines.

An empirical investigation of the impact of global energy transition on Nigerian oil and gas exports

18 months embargo on the thesis and check appendix for copy right materials

Energy performance comparison of three innovative HVAC systems for renovation through dynamic simulation

In this paper, dynamic simulation was used to compare the energy performance of three innovativeHVAC systems: (A) mechanical ventilation with heat recovery (MVHR) and micro heat pump, (B) exhaustventilation with exhaust air-to-water heat pump and ventilation radiators, and (C) exhaust ventilationwith air-to-water heat pump and ventilation radiators, to a reference system: (D) exhaust ventilation withair-to-water heat pump and panel radiators. System A was modelled in MATLAB Simulink and systems Band C in TRNSYS 17. The reference system was modelled in both tools, for comparison between the two.All systems were tested with a model of a renovated single family house for varying U-values, climates,infiltration and ventilation rates.It was found that A was the best system for lower heating demand, while for higher heating demandsystem B would be preferable. System C was better than the reference system, but not as good as A or B.The difference in energy consumption of the reference system was less than 2 kWh/(m2a) betweenSimulink and TRNSYS. This could be explained by the different ways of handling solar gains, but also bythe fact that the TRNSYS systems supplied slightly more than the ideal heating demand.

Investigating Angiotensin II in cardiac remodelling and the counter-regulatory actions of Angiotensin-(1-9)

Cardiovascular diseases (CVDs) including, hypertension, coronary heart disease and heart failure are the leading cause of death worldwide. Hypertension, a chronic increase in blood pressure above 140/90 mmHg, is the single main contributor to deaths due to heart disease and stroke. In the heart, hypertension results in adaptive cardiac remodelling, including LV hypertrophy to normalize wall stress and maintain cardiac contractile function. However, chronic increases in BP results in the development of hypertensive heart disease (HHD). HHD describes the maladaptive changes during cardiac remodelling which result in reduced systolic and diastolic function and eventually heart failure. This includes ventricular dilation due to eccentric hypertrophy, cardiac fibrosis which stiffens the ventricular wall and microvascular rarefaction resulting in a decrease in coronary blood flow albeit an increase in energy demand. Chronic activation of the renin-angiotensin-system (RAS) with its effector peptide angiotensin (Ang)II plays a key role in the development of hypertension and the maladaptive changes in HHD. Ang II acts via the angiotensin type 1 receptor (AT1R) to mediate most of its pathological actions during HHD, including stimulation of cardiomyocyte hypertrophy, activation of cardiac fibroblasts and increased collagen deposition. The counter-regulatory axis of the RAS which is centred on the ACE2/Ang-(1-7)/Mas axis has been demonstrated to counteract the pathological actions of Ang II in the heart and vasculature. Ang-(1-7) via the Mas receptor prevents Ang II-induced cardiac hypertrophy and fibrosis and improves cardiac contractile function in animal models of HHD. In contrast, less is known about Ang-(1-9) although evidence has demonstrated that Ang-(1-9) also antagonises Ang II and is anti-hypertrophic and anti-fibrotic in animal models of acute cardiac remodelling. However, so far it is not well documented whether Ang-(1-9) can reverse established cardiac dysfunction and remodelling and whether it is beneficial when administered chronically. Therefore, the main aim of this thesis was to assess the effects of chronic Ang-(1-9) administration on cardiac structure and function in a model of Ang II-induced cardiac remodelling. Furthermore, this thesis aimed to investigate novel pathways contributing to the pathological remodelling in response to Ang II. First, a mouse model of chronic Ang II infusion was established and characterised by comparing the structural and functional effects of the infusion of a low and high dose of Ang II after 6 weeks. Echocardiographic measurements demonstrated that low dose Ang II infusion resulted in a gradual decline in cardiac function while a high dose of Ang II induced acute cardiac contractile dysfunction. Both doses equally induced the development of cardiac hypertrophy and cardiac fibrosis characterised by an increase in the deposition of collagen I and collagen III. Moreover, increases in gene expression of fibrotic and hypertrophic markers could be detected following high dose Ang II infusion over 6 weeks. Following this characterisation, the high dose infusion model was used to assess the effects of Ang-(1-9) on cardiac structural and functional remodelling in established disease. Initially, it was evaluated whether Ang-(1-9) can reverse Ang II-induced cardiac disease by administering Ang-(1-9) for 2-4 weeks following an initial 2 week infusion of a high dose of Ang II to induce cardiac contractile dysfunction. The infusion of Ang-(1-9) for 2 weeks was associated with a significant improvement of LV fractional shortening compared to Ang II infusion. However, after 4 weeks fractional shortening declined to Ang II levels. Despite the transient improvement in cardiac contractile function, Ang-(1-9) did not modulate blood pressure, LV hypertrophy or cardiac fibrosis. To further investigate the direct cardiac effects of Ang-(1-9), cardiac contractile performance in response to Ang-(1-9) was evaluated in the isolated Langendorff-perfused rat heart. Perfusion of Ang-(1-9) in the paced and spontaneously beating rat heart mediated a positive inotropic effect characterised by an increase in LV developed pressure, cardiac contractility and relaxation. This was in contrast to Ang II and Ang-(1-7). Furthermore, the positive inotropic effect to Ang-(1-9) was blocked by the AT1R antagonist losartan and the protein kinase A inhibitor H89. Next, endothelial-to-mesenchymal transition (EndMT) as a novel pathway that may contribute to Ang II-induced cardiac remodelling was assessed in Ang II-infused mice in vivo and in human coronary artery endothelial cells (HCAEC) in vitro. Infusion of Ang II to mice for 2-6 weeks resulted in a significant decrease in myocardial capillary density and this was associated with the occurrence of dual labelling of endothelial cells for endothelial and mesenchymal markers. In vitro stimulation of HCAEC with TGFβ and Ang II revealed that Ang II exacerbated TGF-induced gene expression of mesenchymal markers. This was not correlated with any changes in SMAD2 or ERK1/2 phosphorylation with co-stimulation of TGFβ and Ang II. However, superoxide production was significantly increased in HCAEC stimulated with Ang II but not TGFβ. Finally, the role of Ang II in microvesicle (MV)-mediated cardiomyocyte hypertrophy was investigated. MVs purified from neonatal rat cardiac fibroblasts were found to contain detectable Ang II and this was increased by stimulation of fibroblasts with Ang II. Treatment of cardiomyocytes with MVs derived from Ang II-stimulated fibroblasts induced cardiomyocyte hypertrophy which could be blocked by the AT1R antagonist losartan and an inhibitor of MV synthesis and release brefeldin A. Furthermore, Ang II was found to be present in MVs isolated from serum and plasma of Ang II-infused mice and SHRSP and WKY rats. Overall, the findings of this thesis demonstrate for the first time that the actions of Ang-(1-9) in cardiac pathology are dependent on its time of administration and that Ang-(1-9) can reverse Ang II-induced cardiac contractile dysfunction by acting as a positive inotrope. Furthermore, this thesis demonstrates evidence for an involvement of EndMT and MV signalling as novel pathways contributing to Ang II-induced cardiac fibrosis and hypertrophy, respectively. These findings provide incentive to further investigate the therapeutic potential of Ang-(1-9) in the treatment of cardiac contractile dysfunction in heart disease, establish the importance of novel pathways in Ang II-mediated cardiac remodelling and evaluate the significance of the presence of Ang II in plasma-derived MVs.