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Beetroot juice (BRJ) has become increasingly popular amongst athletes aiming to improve sport performances. BRJ contains high concentrations of nitrate, which can be converted into nitric oxide (NO) after consumption. NO has various functions in the human body, including a vasodilatory effect, which reduces blood pressure and increases oxygen- and nutrient delivery to various organs. These effects indicate that BRJ may have relevant applications in prevention and treatment of cardiovascular disease. Furthermore, the consumption of BRJ also has an impact on oxygen delivery to skeletal muscles, muscle efficiency, tolerance and endurance and may thus have a positive impact on sports performances. Aside from the beneficial aspects of BRJ consumption, there may also be potential health risks. Drinking BRJ may easily increase nitrate intake above the acceptable daily intake, which is known to stimulate the endogenous formation of N-nitroso compounds (NOC's), a class of compounds that is known to be carcinogenic and that may also induce several other adverse effects. Compared to studies on the beneficial effects, the amount of data and literature on the negative effects of BRJ is rather limited, and should be increased in order to perform a balanced risk assessment.

Since the full development of the ex vivo dual perfusion model of the human placenta cotyledon, the technique has provided essential insight into how nutrients, lipids, gases, immunoglobulins, endocrine agents, pharma-ceuticals, chemicals, nanoparticles, micro-organisms and parasites might traverse the maternofetal barrier. Additionally, the model has been instrumental in gaining a better understanding of the regulation of vascular tone, endocrinology and metabolism within this organ. The human placenta is unique amongst species in its anatomy and transfer modalities. This orthologous diversity therefore requires an appropriate consideration of placental transfer rates of compounds, particles and micro-organisms specific to humans. Different research centres have adapted this model with a wide variation in perfusion parameters, including in the establishment of perfusion, perfusate composition, gassing regime, cannulation method, flow rates, perfused tissue mass, and also in the application of quality control measures. The requirement to harmonise and stan-dardise perfusion practice between centres is largely driven by the need to obtain consistency in our under -standing of placental function, but also in the qualification of the model for acceptance by regulatory agencies in drug and toxicology testing. A pilot study is proposed, aiming to describe how existing inter-centre variation in perfusion methodology affects placental metabolism, protein synthesis, oxygen consumption, the materno-fetal transfer of key molecular markers, and placental structure.

Offshore windfarms (OWFs) offer part of the solution for the energy transition which is urgently needed to mitigate effects of climate change. Marine life has rapidly exploited the new habitat offered by windfarm structures, resulting in increased opportunities for filter- and suspension feeding organisms. In this study, we investigated the effects of organic matter (OM) deposition in the form of fecal pellets expelled by filtering epifauna in OWFs, on mineralization processes in the sediment. OM deposition fluxes produced in a 3D hydrodynamic model of the Southern Bight of the North Sea were used as input in a model of early diagenesis. Two scenarios of OWF development in the Belgian Part of the North Sea (BPNS) and its surrounding waters were calculated and compared to a no-OWF baseline simulation. The first including constructed OWFs as of 2021, the second containing additional planned OWFs by 2026. Our results show increased total mineralization rates within OWFs (27–30%) in correspondence with increased deposition of reactive organic carbon (OC) encapsulated in the OM. This leads to a buildup of OC in the upper sediment layers (increase by ∼10%) and an increase of anoxic mineralization processes. Similarly, denitrification rates within the OWFs increased, depending on the scenario, by 2–3%. Effects were not limited to the OWF itself: clear changes were noticed in sediments outside of the OWFs, which were mostly opposite to the “within-OWF” effects. This contrast generated relatively small changes when averaging values over the full modeling domain, however, certain changes, such as for example the increased storage of OC in sediments, may be of significant value for national / regional carbon management inventories. Our results add to expectations of ecosystem-wide effects of windfarms in the marine environments, which need to be researched further given the rapid rate of expansion of OWFs.

Orientador: Vera Aparecida Madruga Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica Resumo: O presente estudo analisou as respostas dos indicadores de força, densidade mineral óssea (DMO), taxa metabólica de repouso (TMR), composição corporal e capacidade aeróbia (O2 máximo e limiar anaeróbio) após intervenção de 16 semanas de treinamento com pesos (TP). Participaram desta pesquisa 22 voluntárias, na pós-menopausa (12 meses sem menstruações) subdivididas em dois grupos: grupo treinado (GT n=12) e grupo controle (GC n=10). O programa de TP teve freqüência de três sessões semanais em dias alternados, compreendendo 10 exercícios para membros superiores, inferiores e tronco, sendo realizado três séries de 10 repetições máximas (RM) na etapa 1 e três séries de 8 RM na etapa 2. Os níveis de força foram mensurados pelo teste de 1-RM, a composição corporal foi obtida pelo método de espessura de dobras cutâneas, a avaliação da DMO foi realizada por Densitometria Radiológica de Dupla Energia nas regiões da coluna lombar e colo do fêmur, a TMR e o O2 máximo foram obtidos por meio de calorimetria indireta, sendo a TMR calculada por meio da equação de Weir (1949). O O2 máximo foi obtido durante teste de esforço progressivo em esteira até a exaustão. Para análise dos dados foi utilizado o teste de Kruskal-Wallis, para avaliar os efeitos do TP intra e intergrupos e a correlação de Spearman nas correlações utilizadas. Os resultados encontrados mostraram aumentos com diferenças estatisticamente significantes para as cargas levantadas nos testes de 1-RM para supino e leg press no GT e nenhuma modificação foi encontrada para o GC. Não foram obtidas diferenças significantes para os valores de DMO, tanto da coluna quanto do fêmur, da TMR e do O2 pico e limiar anaeróbio em ambos os grupos. O treinamento com pesos foi eficaz para aumentar a força muscular, entretanto 16 semanas de intervenção não foram suficientes para provocar alterações significantes na DMO, na TMR e na capacidade aeróbia. Abstract: This study examined the adaptive responses of indicators of strength, bone mineral density (BMD), the resting metabolic rate (RMR) and aerobic capacity (O2 max and anaerobic threshold ) after 16 weeks intervention resistance training program (RT). Participated 22 postmenopausal women (12 months without menstruation), subdivided in two groups: trained group (GT n = 12) and control group (GC n = 10). The RT period had frequency of three sessions per week on alternate days, with 10 exercises for upper limbs and lower limbs, and performed three sets of 10 repetitions maximum (RM) in step 1 and three sets of 8 RM in step 2. The levels of strength were measured by the 1-RM test, body composition was obtained by the method of skinfolds, the assessment of BMD was performed by densitometry of Radiological Dual Energy in the regions of lumbar spine and the femoral neck, and the RMR and O2 max were obtained by indirect calorimetry and the RMR calculated using equation of Weir (1949). The O2 max was obtained during progressive test on a treadmill until exhaustion. For statistical analysis we used the Kruskal-Wallis test to assess the effects of intra and inter RT and the Spearman correlation to the correlations used. The results showed statistically significant differences increase for the load being strength in the 1-RM tests and supine leg press for the GT and no change was found to GC. No significant differences were obtained for the BMD of the spine on both the femur, O2 peak and the TMR in both groups. RT was effective to increase muscle strength, but 16 weeks were not sufficient to cause changes in BMD, in TMR and aerobic capacity. Mestrado Atividade Física, Adaptação e Saúde Mestre em Educação Física

Background Advanced glycation end products (AGEs) are associated with aging, diabetes mellitus (DM), and other chronic diseases. Recently, the accumulation of AGEs can be evaluated by skin autofluorescence (SAF). However, the relationship between SAF levels and exercise capacity in patients with cardiovascular disease (CVD) remains unclear. This study aimed to investigate the association between the tissue accumulation of AGEs and clinical characteristics, including exercise capacity, in patients with CVD. Methods We enrolled 319 consecutive CVD patients aged ≥40 years who underwent early phase II cardiac rehabilitation (CR) at our university hospital between November 2015 and September 2017. Patient background, clinical data, and the accumulation of AGEs assessed by SAF were recorded at the beginning of CR. Characteristics were compared between two patient groups divided according to the median SAF level (High SAF and Low SAF). Results The High SAF group was significantly older and exhibited a higher prevalence of DM than the Low SAF group. The sex ratio did not differ between the two groups. AGE levels showed significant negative correlations with peak oxygen uptake and ventilator efficiency (both P P P = 0.02). Conclusion High levels of tissue accumulated AGEs, as assessed by SAF, were significantly and independently associated with reduced exercise capacity. These data suggest that measuring the tissue accumulation of AGEs may be useful in patients who have undergone CR, irrespective of whether they have DM.

This systematic review evaluated which outcome variables and cut-off values of pretreatment exercise tests are associated with treatment complications in patients with stage I-III non-small cell lung cancer (NSCLC). PRISMA and Cochrane guidelines were followed. A total of 38 studies with adult patients undergoing treatment for stage I-III NSCLC who completed pretreatment exercise tests, and of whom treatment-related complications were recorded were included. A lower oxygen uptake at peak exercise amongst several other variables on the cardiopulmonary exercise test and a lower performance on field tests, such as the incremental shuttle walk test, stair-climb test, and 6-minute walk test, were associated with a higher risk for postoperative complications and/ or postoperative mortality. Cut-off values were reported in a limited number of studies and were inconsistent. Due to the variety in outcomes, further research is needed to evaluate which outcomes and cut-off values of physical exercise tests are most clinically relevant.

It is not clear how converting epidural analgesia for labour to epidural anaesthesia for emergency caesarean section affects either cutaneous vasomotor tone or mean body temperature. We hypothesised that topping up a labour epidural blocks active cutaneous vasodilation (cutaneous heat loss and skin blood flow decrease), and that as a result mean body temperature increases. Twenty women in established labour had body temperature, cutaneous heat loss and skin blood flow recorded before and after epidural top-up for emergency caesarean section. Changes over time were analysed with repeated measures ANOVA. Mean (SD) mean body temperature was 36.8 (0.5)°C at epidural top-up and 36.9 (0.6)°C at delivery. Between epidural top-up and delivery, the mean (SD) rate of increase in mean body temperature was 0.5 (0.5) °C.h-1 . Following epidural top-up, chest (p < 0.001) and forearm (p = 0.004) heat loss decreased, but head (p = 0.05), thigh (p = 0.79) and calf (p = 1.00) heat loss did not change. The mean (SD) decrease in heat loss was 15 (19) % (p < 0.001). Neither arm (p = 0.06) nor thigh (p = 0.10) skin blood flow changed following epidural top-up. Despite the lack of change in skin blood flow, the most plausible explanation for the reduction in heat loss and the increase in mean body temperature is blockade of active cutaneous vasodilation. It is possible that a similar mechanism is responsible for the hyperthermia associated with labour epidural analgesia.

Aims Regional myocardial work may be assessed by pressure–strain analysis using a non-invasive estimate of left ventricular pressure (LVP). Strain by speckle tracking echocardiography (STE) is not always accessible due to poor image quality. This study investigated the estimation of regional myocardial work from strain by feature tracking (FT) cardiac magnetic resonance (CMR) and non-invasive LVP. Methods and results Thirty-seven heart failure patients with reduced ejection fraction, left bundle branch block (LBBB), and no myocardial scar were compared to nine controls without LBBB. Circumferential strain was measured by FT-CMR in a mid-ventricular short-axis cine view, and longitudinal strain by STE. Segmental work was calculated by pressure–strain analysis. Twenty-five patients underwent 18F-fluorodeoxyglucose (FDG) positron emission tomography. Segmental values were reported as percentages of the segment with maximum myocardial FDG uptake. In LBBB patients, net CMR-derived work was 51 ± 537 (mean ± standard deviation) in septum vs. 1978 ± 1084 mmHg·% in the left ventricular (LV) lateral wall (P Conclusion FT-CMR in combination with non-invasive LVP demonstrated markedly reduced work in septum compared to the LV lateral wall in patients with LBBB. Work distribution correlated with STE-derived work and energy demand as reflected in FDG uptake. These results suggest that FT-CMR in combination with non-invasive LVP is a relevant clinical tool to measure regional myocardial work.

During migration, swimming in schools provides fish with a number of behavioural and ecological advantages, including increased food supply and reduced predation risk. Previous work shows that carangiform and tunniform swimming result in energetic advantages for individuals using a diamond swimming formation. However, little is known about the potential energetic advantage associated with schooling for anguilliform fish, such as European eel. European eels migrate over a long distance to their spawning area in the Sargasso Sea and may experience energetic advantages when swimming in schools. In this study the effect of group-wise swimming on the cost of transport was tested. In addition, the swimming pattern of eels swimming in groups was studied. Male silver eels were individually subjected to an increased velocity test (0.4–0.9 m s − 1 ) with increments of 0.1 m s − 1 every 2 h. Groups comprising of seven males were swum following the same protocol. Video recordings were obtained to analyse tail beat frequency at the various water speeds. At all swimming speeds the oxygen consumption was significantly lower in group-wise vs. individually swimming males. The cost of transport at the optimal swimming speed of group-wise swimming males was significantly lower than that of the individually swimming males (21.3 ± 3.2 vs. 32.0 ± 0.6 mg O 2 kg − 1 h − 1 , respectively). The optimal swimming speeds, however, were not significantly different (0.57 ± 0.02 and 0.52 ± 0.04 m s − 1 respectively). At speeds of 0.50 m s − 1 and above, tail beat frequency was lower in males swimming in groups than in males swimming individually (2.6 ± 0.1 and 3.8 ± 0.1, respectively). In contrast to the ‘diamond’ shape pattern of many group-wise swimming fish, eels tend to swim in a synchronized fashion parallel to each other, possibly reducing swimming costs by Karman gaiting. Although not an evidence, the present study provides support for the assumption of group migration in European eels.

The air-breathing fish Pangasianodon hypophthalmus has been shown to have highly plastic branchial surfaces whose area (SA) increases with temperature and aquatic hypoxia. This modulation occurs through development of inter-lamellar cell mass (ILCM). Paradoxically, in conditions where this fish has been shown capable of covering its entire aerobic scope from the water phase, it has been shown to have a very small branchial SA. To address this paradox, we measured the SA, harmonic mean diffusion distance (tau(h)) and calculated the anatomic diffusion factor (ADF) of the branchial and swim bladder surfaces in fish ranging from 3 to 1900 g at 27 degrees C in normoxia. Since the lamellae were distinguishable from the ILCM, we measured the actual SA as well as the potential SA if ILCM were lost. As a result of low tau(h), P. hypophthalmus has a high capacity for branchial oxygen uptake with or without ILCM. Actual and potential gill ADF were 361 and 1002 cm(2) mu m(-1) kg(-1), respectively, for a 100 g fish and the ADF of the swim bladder was found to be 308 cm(2) mu m(-1) kg(-1). By swimming fish to exhaustion at different temperatures, we show that modulation of this SA is rapid, indicating that the apparent paradox between previous studies is eliminated. Regression analysis of log-log plots of respiratory SA in relation to body mass shows that the gill scales with mass similarly to the SA in active water-breathing fish, whereas the swim bladder scales with mass more like the mammalian lung does. This fish presents a combination of respiratory surfaces not previously seen in air-breathing fish.

Background Necrotizing enterocolitis (NEC) is an important cause of mortality and morbidity in preterm infants. Aims To evaluate the effect of maternal preeclampsia on the development and severity of NEC in premature infants. Study design Prospective observational study in a tertiary neonatal intensive care unit. Subjects The preterm infants of ≤ 37 gestational age who were consecutively hospitalized were enrolled. The study group contained preterm infants born to a preeclamptic mother and the comparison group contained preterm infants born to a normotensive mother. Outcome measures The primary outcome was to determine the association between preeclampsia and NEC. Results A total of 88 infants had NEC diagnosis. The incidence of NEC in infants born to preeclamptic mothers (22.9%) was significantly higher compared with those born to normotensive mothers (14.6%). According to NEC stages, NEC was more advanced in preeclamptic mother infants. NEC developed significantly earlier in infants with NEC in the study group. The duration of NEC was also significantly longer in infants born to preeclamptic mothers. In multiple logistic regression model, preeclampsia was found to be predictive of NEC with an odds ratio of 1.74 (95% confidence interval 0.64–0.92). Conclusions Maternal preeclampsia may be an important risk factor for the development of NEC in premature infants as NEC incidence and severity of NEC were found to be significantly higher in premature infants born to preeclamptic mothers. The onset of NEC was significantly earlier and duration of NEC was longer in these infants.

Neuronal computation is energetically expensive. Consequently, the brain's limited energy supply imposes constraints on its information processing capability. Most brain energy is used on synaptic transmission, making it important to understand how energy is provided to and used by synapses. We describe how information transmission through presynaptic terminals and postsynaptic spines is related to their energy consumption, assess which mechanisms normally ensure an adequate supply of ATP to these structures, consider the influence of synaptic plasticity and changing brain state on synaptic energy use, and explain how disruption of the energy supply to synapses leads to neuropathology.

In the last decades the Lattice Boltzmann method (LB) has been successfully used to simulate a variety of processes. The LB model describes the microscopic processes occurring at the cellular level and the macroscopic processes occurring at the continuum level with a unique function, the probability distribution function. Recently, it has been tried to couple deterministic approaches with probabilistic cellular automata (probabilistic CA) methods with the aim to model temporal evolution of tumor growths and three dimensional spatial evolution, obtaining hybrid methodologies. Despite the good results attained by CA-PDE methods, there is one important issue which has not been completely solved: the intrinsic stochastic nature of the interactions at the interface between cellular (microscopic) and continuum (macroscopic) level. CA methods are able to cope with the stochastic phenomena because of their probabilistic nature, while PDE methods are fully deterministic. Even if the coupling is mathematically correct, there could be important statistical effects that could be missed by the PDE approach. For such a reason, to be able to develop and manage a model that takes into account all these three level of complexity (cellular, molecular and continuum), we believe that PDE should be replaced with a statistic and stochastic model based on the numerical discretization of the Boltzmann equation: The Lattice Boltzmann (LB) method. In this work we introduce a new hybrid method to simulate tumor growth and immune system, by applying Cellular Automata Lattice Boltzmann (CA-LB) approach. (c) 2011 Elsevier B.V. All rights reserved.

SUMMARY One route to gain insight into the causes and consequences of ecological differentiation is to understand the underlying physiological mechanisms. We explored the relationships between immunological and oxidative status and investigated how birds cope physiologically with the effects of immune-derived oxidative damage. We successively implemented two experimental manipulations to alter physiological status in a model bird species: the homing pigeon (Columba livia). The first manipulation, an immune supplementation, was achieved by oral administration of lysozyme, a naturally occurring and non-specific antimicrobial enzyme. The second manipulation, an immune challenge, took the form of an injection with lipopolysaccharide, a bacterial endotoxin. Between groups of lysozyme-treated and control birds, we compared lipopolysaccharide-induced changes in reactive oxygen metabolites, total antioxidant capacity, haptoglobin, oxygen consumption, body mass and cloacal temperature. Lysozyme supplementation intensified the lipopolysaccharide-induced inflammatory response and generated short-term oxidative and metabolic costs. We identified significant interactions between immune supplementation and immune challenge in terms of reactive oxygen metabolites, haptoglobin and oxygen consumption. Our study provides alternative interpretations of differences in oxidative and immunological indices and demonstrates that these indices can also fluctuate and interact across very short time scales, reflecting something akin to current ‘health status’ or ‘physiological condition’. These ephemeral effects highlight the need to broadly consider current physiological condition when drawing conclusions that relate physiology to ecology and evolution.

Introduced Pacific oysters Crassostrea gigas have expanded rapidly in the Dutch Oosterschelde estuary, while stocks of native bivalves declined slightly. As a consequence, total filtration pressure increased significantly, which may affect the mortality of bivalve larvae. Better escape abilities in Pacific oyster larvae might be a contributing factor to their rapid geographic expansion. To study whether C gigas larvae are filtered less than larvae of native bivalves, we investigated filtration and ingestion of the larvae of the native Mytilus edulis and introduced C. gigas by the adults of C gigas and M. edulis as well as the native Cerastoderma edule.We measured filtration rates of C gigas and M. edulis larvae by the adult bivalves (C gigas, M. edulis and C. edule), and compared these to filtration rates of algae. Additionally, we studied the fate of filtered larvae. All three adult species filtered both C gigas and M. edulis larvae. M. edulis larvae were filtered by all three bivalve species with the same filtration rates as algae, whereas filtration rates of C gigas larvae were roughly 50% lower than filtration rates of algae. This suggests that C. gigas larvae can somehow reduce their filtration risk, whereas larvae of M. edulis cannot. The majority of filtered C. gigas and M. edulis larvae were ingested. (C) 2008 Elsevier B.V. All rights reserved.

The burning of two species of pine needles: Pinus halepensis and Pinus pinaster, was studied to characterize the behavior of the forest floor in wildland fires. These fuels are representative of the Mediterranean ecosystem and have very different shapes and surface-to-volume ratios. Calorimetry was performed using the FM-global fire propagation apparatus (FPA). To better understand the effects of transport in the fuel beds, the standard sample holder was replaced by a holder that allowed for the porous properties of the fuel to be studied in a systematic manner. These holders were designed with holes on the surface to allow for different air flow rates to pass through the holder and into the fuel sample. These characteristics created different internal fuel bed conditions and were the first such tests that could be identified that examined transport on this level in these types of wildland fuels. Tests were conducted under natural convection and forced flow. The test series results were analyzed with respect to the direct values of the measured variables and calculated values of heat release rate. Discrete variables of time to ignition, duration of flaming combustion and peak heat release rate were compared using an analysis of variance method. As the experiments were conducted under well-ventilated conditions, the heat release rate calculated by calorimetry was compared to mass loss rate and heat of combustion. CO concentration in time proved to be a good indicator of the combustion dynamics in the fuel bed. Heat release rate, time to ignition and time to reach peak heat release rate indicated a strong dependence on flow conditions and on fuel specie. It was shown that the transport processes in the fuel beds had a significant effect on the burning characteristics.

The determination of the appropriate energy and nutritional requirements of a newborn infant requires a clear goal of the energy and other compounds to be administered, valid methods to measure energy balance and body composition, and knowledge of the neonatal metabolic capacities. Providing an appropriate amount of energy to newborn infants remains a challenge considering the great number of newborn infants who suffer in-hospital growth retardation. The energy requirements of a newborn infant are influenced by several factors - basal metabolism, growth, energy expenditure, and energy losses - which change continuously during development. Calculating the energy requirements of preterm infants is subject to error if general recommendations are applied without recognition of the large variation in factors that influence, for example, energy expenditure. Therefore, energy recommendations should be individualized and preferably based on measurements of energy expenditure. In particular, extremely low birth-weight and very low birth-weight infants are prone to develop negative energy and nutrient balances, due to Low energy intake, low energy reserves and high energy demands. Early energy accretion is not only essential for growth but also influences neurodevetopmental outcome and physical health in the tong term, thereby underlining the importance of adequate neonatal nutrition. (c) 2006 Elsevier Ltd. All rights reserved.

Skeletal muscle mitochondria play a specific role in many disease pathologies. As such, the measurement of oxygen consumption as an indicator of mitochondrial function in this tissue has become more prevalent. Although many technologies and assays exist that measure mitochondrial respiratory pathways in a variety of cells, tissue and species, there is currently a void in the literature in regards to the compilation of these assays using isolated mitochondria from mouse skeletal muscle for use in microplate based technologies. Importantly, the use of microplate based respirometric assays is growing among mitochondrial biologists as it allows for high throughput measurements using minimal quantities of isolated mitochondria. Therefore, a collection of microplate based respirometric assays were developed that are able to assess mechanistic changes/adaptations in oxygen consumption in a commonly used animal model. The methods presented herein provide step-bystep instructions to perform these assays with an optimal amount of mitochondrial protein and reagents, and high precision as evidenced by the minimal variance across the dynamic range of each assay. Published version

Buoyancy is a major determinant of locomotory cost in diving animals. As seabirds have a large amount of air in their feathers and respiratory system, they should work hard against buoyancy to descend in the water column. Since buoyancy decreases with increasing hydrostatic pressure, shallow divers, especially, should work against buoyancy during both the descent and bottom phases of their dives. We deployed miniaturised depth and acceleration recorders on freeranging, foot-propelled divers (great cormorants Phalacrocorax carbo) and flipper-propelled divers (little penguins Eudyptula minor) foraging in shallow waters, where both are positively buoyant. We monitored the diving strategies of the birds to assess how they manage to counteract buoyancy using 2 alternative locomotory modes. Cormorants decreased the stroke frequency and surge amplitude during descent and maintained constant swim speed. In contrast, penguins did not change their stroke frequency or heave amplitude; as a result, their swim speed increased during the descent phase. During the bottom phase, cormorants had a low stroke frequency and tilted towards the bottom, while penguins actively stroked in a horizontal position. Furthermore, intensive acceleration periods during the bottom phase were often recorded for penguins, but rarely for cormorants. Great cormorants and little penguins used different strategies to feed underwater. Great cormorants, having lower specific buoyancy, were less active than little penguins, thus adopting an energysaving strategy. We conclude that both foot- and wing-propelled birds diving in shallow waters have developed efficient locomotory strategies to counteract buoyancy, these alternative characteristics being linked to different foraging niches.

Respiratory water loss in Starlings (Sturnus vulgaris) at rest and during flight at ambient temperatures (T-amb) between 6 and 25 degrees C was calculated from respiratory airflow and exhaled air temperature. At rest, breathing frequency f(1.4 +/- 0.3 Hz) and tidal volume V-t (1.9 +/- 0.4 ml) were independent of T-amb but negatively correlated with each other. Mean ventilation at rest was 156 +/- 28 ml min(-1) at all T-amb. Exhaled air temperature (T-exh) at rest increased with T-amb (T-exh=0.92 center dot T-amb+12.45). Respiratory water loss at rest averaged 0.18 +/- 0.09 ml h(-1) irrespective of T-amb. In flying Starlings f was 4.0 +/- 0.4 Hz and independent of T-amb. V-t during flight averaged 3.6 +/- 0.4 ml and increased with T-amb (V-t=0.06 center dot T-amb+2.83) as, correspondingly, did ventilation. T-exh during flight increased with T-amb (T-exh=0.85 center dot T-amb+17.29). Respiratory water loss during flight (average REWLf=0.74 +/- 0.22 ml h(-1)) was significantly higher than at rest and increased with T-amb. Our measurements suggest that respiratory evaporation accounts for most water loss in flying Starlings and increases more than cutaneous evaporation with rising ambient temperature. (c) 2006 Elsevier Inc. All rights reserved.

Objective: To characterize a long-term model of recovery from critical illness, with particular emphasis on cardiorespiratory, metabolic, and muscle function. Design: Randomized controlled animal study. Setting: University research laboratory. Subjects: Male Wistar rats. Interventions: Intraperitoneal injection of the fungal cell wall constituent, zymosan or n-saline. Measurements and Main Results: Following intervention, rats were followed for up to 2 weeks. Animals with zymosan peritonitis reached a clinical and biochemical nadir on day 2. Initial reductions were seen in body weight, total body protein and fat, and muscle mass. Leg muscle fiber diameter remained subnormal at 14 days with evidence of persisting myonecrosis, even though gene expression of regulators of muscle mass (e.g., MAFbx, MURF1, and myostatin) had peaked on days 2–4 but normalized by day 7. Treadmill exercise capacity, forelimb grip strength, and in vivo maximum tetanic force were also reduced. Food intake was minimal until day 4 but increased thereafter. This did not relate to appetite hormone levels with early (6 hr) rises in plasma insulin and leptin followed by persisting subnormal levels; ghrelin levels did not change. Serum interleukin-6 level peaked at 6 hours but had normalized by day 2, whereas interleukin-10 remained persistently elevated and high-density lipoprotein cholesterol persistently depressed. There was an early myocardial depression and rise in core temperature, yet reduced oxygen consumption and respiratory exchange ratio with a loss of diurnal rhythmicity that showed a gradual but incomplete recovery by day 7. Conclusions: This detailed physiological, metabolic, hormonal, functional, and histological muscle characterization of a model of critical illness and recovery reproduces many of the findings reported in human critical illness. It can be used to assess putative therapies that may attenuate loss, or enhance recovery, of muscle mass and function.

Great Knots (Calidris tenuirostris) make one of the longest migratory flights in the avian world, flying almost 5500 km from Australia to China during northward migration. We measured basal metabolic rate (BMR) and body composition in birds before and after this flight and found that BMR decreased 42%. The mass-specific BMR based on lean mass decreased 33%. We also starved a group of pre-migratory Great Knots in captivity to determine whether they showed the same reduction in BMR without having undergone the hard work of flight. The captive birds showed a similar range and reduction of BMR values as the wild birds. Exponents of relationships between BMR and body mass in different comparisons were high, indicating large changes in BMR as a function of body mass. Analysis of the body composition of ten wild and three captive birds found that the flight muscle mass and intestine mass positively correlated with BMR.La Tasa Metabolica Basal Disminuye durante Vuelos Migratorios de Larga Distancia en Calidris tenuirostrisResumen. Calidris tenuirostris realiza uno de los vuelos migratorios más largos entre las aves, volando desde Australia hasta China durante la migración al norte. Medimos la tasa metabólica basal (TMB) y la composición corporal en aves antes y después del vuelo y encontramos que TMB se reduce en 42%. La TMB específica por masa, o sea la TMB corregida por masa magra, se redujo en 33%. También expusimos un grupo premigratorio de Calidris tenuirostris a un periodo de ayuno en cautiverio, para determinar si mostraban una tasa de reducción similar en la TMB sin haber soportado la dura tarea de volar. Las aves en cautiverio mostraron un rango y una reducción de los valores de la TMB similares a los de las aves en libertad. Los exponentes de la relación entre TMB y masa corporal en diferentes comparaciones fueron altos, indicando grandes cambios de la TMB en función de la masa corporal. El análisis de la composición corporal de diez aves libres y tres en cautiverio mostró que la masa de los músculos del vuelo y la masa de los intestinos esta positivamente correlacionada con la TMB.

The pattern of cytosolic ADP recovery after exercise has not been fully characterized in human skeletal muscle. ADP recovery after brief, ischemic exercise was studied by 31phosphorus magnetic resonance spectroscopy in calf muscles of 33 normal control subjects, four patients with McArdle's disease and 13 patients with mitochondrial myopathy. In normal muscle, the half-time for the initial ADP decline was 0.18 +/- 0.07 min and was unaffected by the pH or the metabolic state at the end of exercise. ADP decreased to below rest values during the second min of recovery in 27 out of 33 control subjects. There was a significant (p < 0.001) linear correlation for both the size (r = 0.65) and duration (r = 0.64) of this ADP undershoot with intracellular pH. Phosphocreatine resynthesis continued during the ADP undershoot. ADP undershoot was also found in patients with mitochondrial diseases (in 11 out of 13), but not McArdle's disease (six patients). Thus ADP recovery follows a complex time course that is partly dependent on pH. Only the initial ADP recovery is independent of pH, which makes it suitable for comparative assessment of muscle mitochondrial function in vivo. As phosphocreatine recovery continues during the ADP undershoot, mitochondrial regulation must be different from that at the onset of recovery. These observations are consistent with variable, changing regulators of mitochondrial metabolism in human skeletal muscle.

Signaling and insulin secretion in beta cells have been reported to demonstrate oscillatory modes, with abnormal oscillations associated with type 2 diabetes. We investigated cellular glucose influx in beta cells with a self-referencing (SR) microbiosensor based on nanomaterials with enhanced performance. Dose-response analyses with glucose and metabolic inhibition studies were used to study oscillatory patterns and transporter kinetics. For the first time, we report a stable and regular oscillatory uptake of glucose (averaged period 2.9 +/- 0.6 min), which corresponds well with an oscillator model. This oscillatory behavior is part of the feedback control pathway involving oxygen, cytosolic Ca(2+)/ATP, and insulin secretion (periodicity approximately 3 min). Glucose stimulation experiments show that the net Michaelis-Menten constant (6.1 +/- 1.5 mM) is in between GLUT2 and GLUT9. Phloretin inhibition experiments show an EC(50) value of 28 +/- 1.6 mu M phloretin for class I GLUT proteins and a concentration of 40 +/- 0.6 mu M phloretin caused maximum inhibition with residual nonoscillating flux, suggesting that the transporters not inhibited by phloretin are likely responsible for the remaining nonoscillatory uptake, and that impaired uptake via GLUT2 may be the cause of the oscillation loss in type 2 diabetes. Transporter studies using the SR microbiosensor will contribute to diabetes research and therapy development by exploring the nature of oscillatory transport mechanisms. (C) 2010 Elsevier Inc. All rights reserved.

Freshwater planarians have a large totipotent stem cell population allowing high rates of cell renewal and morphological plasticity. It is often suggested that they are able to rejuvenate during fission, regeneration and starvation. These features, together with the rapidly expanding molecular toolset, make planarians such as Schmidtea polychroa and S. mediterranea interesting for ageing research. Yet, the basic demographic and physiological data are lacking or still based on fragmentary observations of one century ago.Here, we present the first longitudinal physiological study of the species S. polychroa. Survival, size and metabolic rate, measured by microcalorimetry, of a cohort of 28 individuals were followed over a period of three years. Sexual maturity was reached during the second month after which the worms continued growing up to 5 months. This initial growth phase was followed by alternating periods of synchronised growth and degrowth. Although mass-specific metabolic rates declined during the initial growth phase, no changes were found later in life. The absence of metabolic ageing may be explained by the very high rate of cell renewal during homeostasis and alternating phases of degrowth and growth during which tissues are renewed.Surprisingly, all deaths occurred in pairs of worms that were housed in the same culture recipient, suggesting that worms did not die from ageing. Taking into account the metabolic and demographic data, we suggest that S. polychroa shows negligible ageing.Detailed analyses of size and metabolic rate revealed a remarkable biphasic allometric scaling relation. During the initial growth phase (months 1-5) the allometric scaling exponent b was 0.86 while later in life, it increased to an unusually large value of 1.17, indicating that mass-specific metabolic rate increases with size in adult S. polychroa. (C) 2011 Elsevier Inc. All rights reserved.

Glucose is the central molecule in many biochemical pathways, and numerous approaches have been developed for fabricating micro biosensors designed to measure glucose concentration in/near cells and/or tissues. An inherent problem for microsensors used in physiological studies is a low signal-to-noise ratio, which is further complicated by concentration drift due to the metabolic activity of cells. A microsensor technique designed to filter extraneous electrical noise and provide direct quantification of active membrane transport is known as self-referencing. Self-referencing involves oscillation of a single microsensor via computer-controlled stepper motors within a stable gradient formed near cells/tissues (i.e., within the concentration boundary layer). The non-invasive technique provides direct measurement of trans-membrane (or trans-tissue) analyte flux. A glucose micro biosensor was fabricated using deposition of nanomaterials (platinum black, multiwalled carbon nanotubes, Nafion) and glucose oxidase on a platinum/iridium microelectrode. The highly sensitive/selective biosensor was used in the self-referencing modality for cell/tissue physiological transport studies. Detailed analysis of signal drift/noise filtering via phase sensitive detection (including a post-measurement analytical technique) are provided. Using this highly sensitive technique, physiological glucose uptake is demonstrated in a wide range of metabolic and pharmacological studies. Use of this technique is demonstrated for cancer cell physiology, bioenergetics, diabetes, and microbial biofilm physiology. This robust and versatile biosensor technique will provide much insight into biological transport in biomedical, environmental, and agricultural research applications. (C) 2010 Elsevier B.V. All rights reserved.

The successes of PET and fMRI in non-invasively localizing sensory functions had encouraged efforts to transform the subjective concepts of cognitive psychology into objective physical measures. The assumption was that mental functions could be decomposed into non-overlapping, context-independent modules that are operated on by separable areas of a computer-like brain. The failures of cognitive modularity and of a very localized phrenology are generally, but not universally, accepted; but in their place, and usually not distinguished from the original revolutionary hopes of clarification, experimental results are being interpreted in terms of rather flexible definitions of both cognitive concepts and the degree of localization. In an alternative approach, we have connected fMRI, (13)C MRS, and electrophysiology measurements of brain energy to connect with observable properties of mental life (i.e., awareness). We illustrate this approach with a sensory stimulation experiment; the degree of localization found in BOLD signals was related to the global energy of the brain which, when manipulated by anesthetics, affected the degree of awareness. The influence of brain energy upon functional imaging maps is changing the interpretations of neuroimaging experiments, from psychological concepts generating computer-like responses to empirical responses dominated by the high brain energy and signaling at rest. In our view "baseline" is an operational term, an adjective that defines a property of a state of the system before it is perturbed by a stimulus. Given the dependence of observable psychological properties upon the "baseline" energy, we believe that it is unnecessarily limiting to de. ne a particular state as the baseline. (C) 2008 Elsevier Inc. All rights reserved.

Most studies evaluating the growth of preterm infants use the so-called intrauterine growth curve and reference fetus as standards. These curves might not be the optimal standards, however, for several reasons. The curves were constructed from small numbers of infants with uncertainty about gestational age, reasons for preterm birth, and, for body-composition data, the reasons for the death of the infant. Second, preterm infants after birth are not comparable with fetuses, being in a completely different environment and receiving a completely different nutrition. For instance, a higher percentage of body fat in preterm infants might well be an adequate adaptation to their environment. To get preterm infants to adhere to their supposed growth curve percentile, catch-up growth is needed. Recent studies indicate that catch-up growth might be advantageous for brain development. It might at the same time increase the incidence of cardiovascular disease in later life. The use of intrauterine growth curves to evaluate postnatal growth needs a critical reevaluation.

Background: Although discontinuation of chronic ACE inhibitor (ACEi) therapy after myocardial infarction (MI) is common in clinical practice, some clinical studies reported an increased incidence of ischemia-related events after withdrawal. To further address this issue, we assessed hemodynamic, neurohormonal and vascular consequences of withdrawing long-term ACEi treatment after experimental MI.Methods: Rats were subjected to coronary ligation to induce MI, and received quinapril (15 mg/kg/day) from 2 weeks to 14 months post-MI. Subsequently, surviving rats were randomized to sacrifice at 0, 4, and 6 weeks after ACEi withdrawal. Rats were studied for signs of heart failure, hemodynamics and cardiac function, neurohormones, and vascular edothelial function.Results: After discontinuation of ACEi treatment, plasma aldosterone levels increased between 0-4 weeks without further increment thereafter, suggesting persistent RAAS activation. Acetylcholine-induced aortic relaxation was impaired at 4 and 6 weeks, indicating rapid and sustained development of endothelial vasodilator dysfunction after withdrawal. Moreover, 24% of the rats developed heart failure signs (edema, dyspnea), and 3 rats died, all within 4 weeks after withdrawal, Significantly increased N-ANP levels and lung weights at 4, but not at 6 weeks suggest a transient volume overload. Finally, LV/body weight ratios significantly increased between 0-4 as well as 4-6 weeks, indicating progressive LV hypertrophy.Conclusions: The observed alterations after withdrawing long-term post-MI quinapril treatment in the present study may account for an increased risk for ischemic events. Thus, our findings highlight the potentially harmful effects associated with abrupt discontinuation of long-term post-MI ACE inhibition, and imply careful clinical consideration in this matter. (c) 2005 European Society of Cardiology. Published by Elsevier B.V All rights reserved.

OBJECTIVES We performed positron emission tomography (PET) to evaluate myocardial ischemia in patients with idiopathic dilated cardiomyopathy (IDC). BACKGROUND Patients with IDC have anatomically normal coronary arteries, and it has been assumed that myocardial ischemia does not occur. METHODS We studied 22 patients with IDC and 22 control subjects using PET with nitrogen-13 ammonia to measure myocardial blood flow (MBF) at rest and during dipyridamole-induced hyperemia. To investigate glucose metabolism, fluorine-18 deoxyglucose ((18)FDG) was used. For imaging of oxygen consumption, carbon-ii acetate clearance rate constants (k(mono)) were assessed at rest and during submaximal dobutamine infusion (20 mu g/kg body weight per min). RESULTS Global MBF reserve (dipyridamole-induced) was impaired in patients with IDC versus control subjects (1.7 +/- 0.21 vs. 2.7 +/- 0.10, p

International audience; Background: Diapause is a developmental arrest present in annual killifish, whose eggs are able to survive long periods of desiccation when the temporary ponds they inhabit dry up. Diapause can occur in three different developmental stages. These differ, within and between species, in their responsiveness to different environmental cues. A role of developmental plasticity and genetic assimilation in diapause evolution has been previously suggested but not experimentally explored. We investigated whether plastic developmental delays or arrests provoked by an unusual and extreme environment could be the ancestral condition for diapause. This would be in agreement with plasticity evolution playing a role in the emergence of diapause in this group. We have used a comparative experimental approach and exposed embryos of non-annual killifish belonging to five different species from the former genus Rivulus to brief periods of desiccation. We have estimated effects on developmental and mortality rates during and after the desiccation treatment.Results: Embryos of these non-annual rivulids decreased their developmental rates in early stages of development in response to desiccation and this effect persisted after the treatment. Two pairs of two different species had sufficient sample sizes to investigate rates of development in later stages well. In one of these, we found cohorts of embryos in the latest stages of development that did not hatch over a period of more than 1 month without mortality. Several properties of this arrest are also used to characterize diapause III in annual killifish. Such a cohort is present in control conditions and increases in frequency in the desiccation treatment.Conclusions: The presence of plasticity for developmental timing and a prolonged developmental arrest in non-annual rivulids, suggest that a plastic developmental delay or diapause might have been present in the shared ancestor of annual and non-annual South American killifish and that the evolution of plasticity could have played a role in the emergence of the diapauses. Further comparative experimental studies and field research are needed to better understand how diapause and its plasticity evolved in this group.

Increased myocardial fatty acid uptake during acute exercise could adversely affect myocardial O2 consumption in lambs with left-to-right shunts, which would be unfavorable in view of their decreased coronary blood flow reserve. Therefore, we studied myocardial substrate uptake (glucose, lactate, pyruvate, free fatty acids, triglycerides, beta-hydroxybutyrate, and acetoacetate) in 10 7-wk-old lambs with an aortopulmonary left-to-right shunt [61 +/- 3% (SE) of left ventricular output] and 9 control lambs during strenuous treadmill exercise. The hemodynamic reaction to exercise was similar in shunt and control lambs. The peripheral metabolic response to exercise was also similar in the two groups: glucose free fatty acids, and, most prominently, lactate concentrations increased. Myocardial O2 consumption increased but less in shunt than in control lambs because of a smaller increase in heart rate. In both groups myocardial lactate uptake increased substantially at the cost of other substrates, providing the heart with 40% of its oxidative metabolism. Fatty acid uptake was not different between the two groups. In conclusion, our data reveal no essential differences in myocardial substrate uptake between shunt and control lambs during a substantial circulatory load.

To determine how much myocardial O2 consumption (VO2) would increase during an additional load on the heart in shunt as compared with control lambs, we studied 12 7-wk-old lambs with an aortopulmonary left-to-right shunt (59 +/- 3% of left ventricular output, mean +/- SE) and 11 control lambs during exercise at 80% of their predetermined peak VO2 (VO2peak), at 12 +/- 1 days after surgery. During exercise, systolic aortic pressure increased by 25% in the two groups. Left atrial pressure and left ventricular stroke volume did not change significantly and remained considerably higher in shunt than in control lambs. Heart rate, however, increased less in shunt than in control lambs (163 +/- 8 to 235 +/- 8 vs. 107 +/- 7 to 230 +/- 8 beats/min). The same was true for left ventricular myocardial blood flow (245 +/- 19 to 391 +/- 27 vs. 128 +/- 10 to 320 +/- 45 ml.min-1 x 100 g-1) and myocardial VO2 (847 +/- 101 to 1,692 +/- 136 vs. 528 +/- 58 to 1,579 +/- 178 mumol O2 x min-1 x 100 g-1). We conclude that, despite the volume load, myocardial VO2 of shunt lambs does not increase to a greater extent than in control lambs during a considerable additional load on the heart.

The purpose of this study was to investigate astrocytic oxidative metabolism using 1-(11)C-acetate. 1-(11)C-acetate kinetics were evaluated in the rat somatosensory cortex using a beta-scintillator during different manipulations (test-retest, infraorbital nerve stimulation, and administration of acetazolamide or dichloroacetate). In humans a visual activation paradigm was used and kinetics were measured with positron emission tomography. Data were analyzed using a one-tissue compartment model. The following features supported the hypothesis that washout of radiolabel (k(2)) is because of (11)C-CO(2) and therefore related to oxygen consumption (CMRO(2)): (1) the onset of (11)C washout was delayed; (2)k(2) was not affected by acetazolamide-induced blood flow increase; (3)k(2) demonstrated a significant increase during stimulation in rats (from 0.014+/-0.007 to 0.027+/-0.006 per minute) and humans (from 0.016+/-0.010 to 0.026+/-0.006 per minute); and (4) dichloroacetate led to a substantial decrease of k(2). In the test-retest experiments K(1) and k(2) were very stable. In summary, 1-(11)C-acetate seems a promising tracer to investigate astrocytic oxidative metabolism in vivo. If the washout rate indeed represents the production of (11)C-CO(2), then its increase during stimulation would point to a substantially higher astrocytic oxidative metabolism during brain activation. However, the quantitative relationship between k(2) and CMRO(2) needs to be determined in future experiments.

Energy expenditure of terrestrial locomotion on a linear treadmill was measured in five wader species: Turnstone Arenaria interpres, Knot Calidris canutus, Grey Plover Pluvialis squatarola, Oystercatcher Haematopus ostralegus and Bar-tailed Godwit Limosa lapponica. Additional data on Redshank Tringa totanus were taken from the literature. The cost of running in these waders, measured as the slope of the regression line of energy expenditure against speed of locomotion, is significantly less than an allometrically calculated slope for all bird species (Taylor et al. 1982). It is also less than in grouse species which, like waders, must walk to gather their food. Cost of running for a 100 g wader is 22% below the cost of a grouse, and 68% below the cost of a hypothetical penguin of similar mass. Intraindividual cost of running in relation to body mass of a Turnstone and interindividual cost of running in Knots reveal much stronger increases of running costs with increasing body mass than interspecific allometric relations would predict, and this elevated activity cost probably importantly influences the set point for body mass regulation in birds.