Influence of Soldiers’ Cardiorespiratory Fitness on Physiological Responses and Dropouts During a Loaded Long-distance March

ABSTRACT Introduction In military service, marching is an important, common, and physically demanding task. Minimizing dropouts, maintaining operational readiness during the march, and achieving a fast recovery are desirable because the soldiers have to be ready for duty, sometimes shortly after an exhausting task. The present field study investigated the influence of the soldiers’ cardiorespiratory fitness on physiological responses during a long-lasting and challenging 34 km march. Materials and Methods Heart rate (HR), body core temperature (BCT), total energy expenditure (TEE), energy intake, motivation, and pain sensation were investigated in 44 soldiers (20.3 ± 1.3 years, 178.5 ± 7.0 cm, 74.8 ± 9.8 kg, body mass index: 23.4 ± 2.7 kg × m−2, peak oxygen uptake ($\dot{\rm{V}}$O2peak): 54.2 ± 7.9 mL × kg−1 × min−1) during almost 8 hours of marching. All soldiers were equipped with a portable electrocardiogram to record HR and an accelerometer on the hip, all swallowed a telemetry pill to record BCT, and all filled out a pre- and post-march questionnaire. The influence of aerobic capacity on the physiological responses during the march was examined by dividing the soldiers into three fitness groups according to their $\dot{\rm{V}}$O2peak. Results The group with the lowest aerobic capacity ($\dot{\rm{V}}$O2peak: 44.9 ± 4.8 mL × kg−1 × min−1) compared to the group with the highest aerobic capacity ($\dot{\rm{V}}$O2peak: 61.7 ± 2.2 mL × kg−1 × min−1) showed a significantly higher (P < .05) mean HR (133 ± 9 bpm and 125 ± 8 bpm, respectively) as well as peak BCT (38.6 ± 0.3 and 38.4 ± 0.2 °C, respectively) during the march. In terms of recovery ability during the break, no significant differences could be identified between the three groups in either HR or BCT. The energy deficit during the march was remarkably high, as the soldiers could only replace 22%, 26%, and 36% of the total energy expenditure in the lower, middle, and higher fitness group, respectively. The cardiorespiratory fittest soldiers showed a significantly higher motivation to perform when compared to the least cardiorespiratory fit soldiers (P = .002; scale from 1 [not at all] to 10 [extremely]; scale difference of 2.3). A total of nine soldiers (16%) had to end marching early: four soldiers (21%) in the group with the lowest aerobic capacity, five (28%) in the middle group, and none in the highest group. Conclusion Soldiers with a high $\dot{\rm{V}}$O2peak showed a lower mean HR and peak BCT throughout the long-distance march, as well as higher performance motivation, no dropouts, and lower energy deficit. All soldiers showed an enormous energy deficit; therefore, corresponding nutritional strategies are recommended.

Influence of fat-free mass and resting metabolic rate on increased food reinforcement after exercise training

Purpose Models of appetite control have been largely based on negative feedback from gut and adipose signaling to central appetite centers. However, contemporary models posit that fat-free mass (FFM) or the energy demand of FFM [i.e., resting metabolic rate (RMR)] may play a primary role in the motivational drive for food intake (i.e., food reinforcement). The relative reinforcing value of food (RRVfood) is associated with energy intake (EI) and increases with an acute energy deficit. Chronic exercise-induced energy deficits lead to alterations in fat mass (FM), FFM, and RMR and provide an opportunity to test whether change in (∆) FM, ∆FFM, ∆usual EI, or ∆RMR are associated with ∆RRVfood. Methods Participants (n = 29, BMI = 25–35 kg/m2) engaged in aerobic exercise expending 300 or 600 kcal, 5 days/weeks for 12 weeks. The reinforcing value of food (PMaxfood) was measured via a computer-based operant responding task and RRVfood was calculated as the reinforcing value of food relative to non-eating sedentary behaviors. RMR was determined by indirect calorimetry and body composition by DXA. Results Post-training FFM correlated with usual post-training EI (rs = 0.41, p < 0.05), PMaxfood (rs=0.52, p < 0.01), and RMR (rs = 0.85, p < 0.0001). ∆RMR negatively correlated with ∆PMaxfood (rs = − 0.38, p < 0.05) and with ∆RRVfood (rs = − 0.37, p < 0.05). ∆PMaxfood and ∆RRVfood were not associated with ∆FFM (p = 0.71, p = 0.57, respectively). Conclusions Reductions in RMR with weight loss may increase food reinforcement as means of restoring FFM and RMR to pre-weight loss amounts. Limiting reductions in RMR during weight loss may benefit weight maintenance by restricting increases in food reinforcement after weight loss.

Nutritional status of patients undergoing upper gastrointestinal cancer surgery: A cross-sectional study at a single centre

Malnutrition is closely related to the outcome of disease treatment, especially in digestive cancer surgery. The aim of this study was to assess the nutritional condition of pre-operative patients with upper digestive cancers (including stomach and oesophagus) at the Department of General Surgery, Bach Mai Hospital in 2016. We conducted a cross-sectional descriptive analysis of 76 malignancies of the upper gastrointestinal tract with surgical treatments. The results revealed that the weight loss rate of hospitalized patients with gastric cancer and esophageal cancer was 76.6% and 66.7%, respectively. The rate of weight loss above 10% of body weight was 19.7%. The prevalence of chronic energy deficit was 29.9%. The risk of malnutrition according to SGA was 77.6%, of which mild to moderate and severe was 67.2% and 10.4%, respectively. The rate of low blood albumin level (less than 35 g/L) was 36.5%. The average net nutritional value was 1146.3 ± 592.7 Kcal (range 246.7 – 3653.5), which equals to 55.7% of the necessary daily intake. Protein, lipid, and glucid contents reached 73.4%, 57.8%, and 52.1% of the recommended levels, respectively. Conclusion: malnutrition was still prevalent among patients undergoing upper gastrointestinal cancer surgery, and pre-operative nutritional status does not achieve recommended levels.

Sustained Energy Deficit Following Perinatal Asphyxia: A Shift towards the Fructose-2,6-bisphosphatase (TIGAR)-Dependent Pentose Phosphate Pathway and Postnatal Development

Labor and delivery entail a complex and sequential metabolic and physiologic cascade, culminating in most circumstances in successful childbirth, although delivery can be a risky episode if oxygen supply is interrupted, resulting in perinatal asphyxia (PA). PA causes an energy failure, leading to cell dysfunction and death if re-oxygenation is not promptly restored. PA is associated with long-term effects, challenging the ability of the brain to cope with stressors occurring along with life. We review here relevant targets responsible for metabolic cascades linked to neurodevelopmental impairments, that we have identified with a model of global PA in rats. Severe PA induces a sustained effect on redox homeostasis, increasing oxidative stress, decreasing metabolic and tissue antioxidant capacity in vulnerable brain regions, which remains weeks after the insult. Catalase activity is decreased in mesencephalon and hippocampus from PA-exposed (AS), compared to control neonates (CS), in parallel with increased cleaved caspase-3 levels, associated with decreased glutathione reductase and glutathione peroxidase activity, a shift towards the TIGAR-dependent pentose phosphate pathway, and delayed calpain-dependent cell death. The brain damage continues long after the re-oxygenation period, extending for weeks after PA, affecting neurons and glial cells, including myelination in grey and white matter. The resulting vulnerability was investigated with organotypic cultures built from AS and CS rat newborns, showing that substantia nigra TH-dopamine-positive cells from AS were more vulnerable to 1 mM of H2O2 than those from CS animals. Several therapeutic strategies are discussed, including hypothermia; N-acetylcysteine; memantine; nicotinamide, and intranasally administered mesenchymal stem cell secretomes, promising clinical translation.

Model systems in SDHx-related pheochromocytoma/paraganglioma

Pheochromocytoma (PHEO) and paraganglioma (PGL) (together PPGL) are tumors with poor outcomes that arise from neuroendocrine cells in the adrenal gland, and sympathetic and parasympathetic ganglia outside the adrenal gland, respectively. Many follow germline mutations in genes coding for subunits of succinate dehydrogenase (SDH), a tetrameric enzyme in the tricarboxylic acid (TCA) cycle that both converts succinate to fumarate and participates in electron transport. Germline SDH subunit B (SDHB) mutations have a high metastatic potential. Herein, we review the spectrum of model organisms that have contributed hugely to our understanding of SDH dysfunction. In Saccharomyces cerevisiae (yeast), succinate accumulation inhibits alpha-ketoglutarate-dependent dioxygenase enzymes leading to DNA demethylation. In the worm Caenorhabditis elegans, mutated SDH creates developmental abnormalities, metabolic rewiring, an energy deficit and oxygen hypersensitivity (the latter is also found in Drosophila melanogaster). In the zebrafish Danio rerio, sdhb mutants display a shorter lifespan with defective energy metabolism. Recently, SDHB-deficient pheochromocytoma has been cultivated in xenografts and has generated cell lines, which can be traced back to a heterozygous SDHB-deficient rat. We propose that a combination of such models can be efficiently and effectively used in both pathophysiological studies and drug-screening projects in order to find novel strategies in PPGL treatment.

Depriving mice of sleep also deprives of food

Both sleep-wake behavior and circadian rhythms are tightly coupled to energy metabolism and food intake. Altered feeding times in mice are known to entrain clock-gene rhythms in brain and liver and sleep-deprived humans tend to eat more and gain weight. Previous observations in mice showing that sleep deprivation (SD) changes clock-gene expression might thus relate to altered food intake and not to the loss of sleep per se. Whether SD affects food intake in the mouse and how this might affect clock-gene expression is, however, unknown. We therefore quantified i) the cortical expression of the clock genes Per1, Per2, Dbp, and Cry1 in mice that had access to food or not during a 6h SD, and ii) food intake during baseline, SD, and recovery sleep. We found that food deprivation did not modify the SD-incurred clock-gene changes in the cortex. Moreover, we discovered that although food intake during SD did not differ from baseline, mice lost weight and increased food intake during subsequent recovery. We conclude that SD is associated with food deprivation and that the resulting energy deficit might contribute to the effects of SD that are commonly interpreted as a response to sleep loss.

Genetic and Mitochondrial Metabolic Analyses of an Atypical Form of Leigh Syndrome

In this study, we aimed to establish the mitochondrial etiology of the proband’s progressive neurodegenerative disease suggestive of an atypical Leigh syndrome, by determining the proband’s pathogenic variants. Brain MRI showed a constellation of multifocal temporally disparate lesions in the cerebral deep gray nuclei, brainstem, cerebellum, spinal cord along with rhombencephalic atrophy, and optic nerve atrophy. Single voxel 1H MRS performed concurrently over the left cerebral deep gray nuclei showed a small lactate peak, increased glutamate and citrate elevation, elevating suspicion of a mitochondrial etiology. Whole exome sequencing revealed three heterozygous nuclear variants mapping in three distinct genes known to cause Leigh syndrome. Our mitochondrial bioenergetic investigations revealed an impaired mitochondrial energy metabolism. The proband’s overall ATP deficit is further intensified by an ineffective metabolic reprogramming between oxidative phosphorylation and glycolysis. The deficient metabolic adaptability and global energy deficit correlate with the proband’s neurological symptoms congruent with an atypical Leigh syndrome. In conclusion, our study provides much needed insights to support the development of molecular diagnostic and therapeutic strategies for atypical Leigh syndrome.

Renewable Energy Sources as the Future of the Energy Sector and Climate in Poland—Truth or Myth in the Opinion of the Society

The electricity sector in the 21st century should be associated with renewable energy sources (RES), which the majority of society currently equates with solar photovoltaics, wind power, and hydroelectricity, with this energy being used mainly in households. Households consume only 20% of energy, with the remainder used in various sectors of the national economy. In these sectors, the possibilities of using renewable energy sources should be sought. Many experts express the opinion that myths about renewable energy sources exist only “in our minds and opinions, that we formed years ago”, mainly under pressure from the decreasing number of supporters of conventional energy sources. Currently, we observe much greater possibilities of using renewable energy sources globally, and all forecasts suggest that—by 2050—the economy, transport, and industry may become almost emission-free and rely on RES. Of course, we cannot present renewable energy sources only in terms of superlatives, because they also involve many unknowns and myths which we will present in the article. Considering the complexity of factors influencing the involvement of young people in shaping the socio-economic reality, a group of people aged between 18 and 40 was selected for the study. The aim of this study was to identify the attitudes of young inhabitants of south-eastern Poland regarding the issues of climate change and renewable energy, and to identify the level of acceptance for changes in Poland’s energy mix. The conducted research shows that the studied group of people appreciated the importance of climate change and considered the anthropogenic impact on this phenomenon to be of key importance. The perception of renewable energy was positive, and respondents saw the solution to the problems of the energy deficit in increasing the use of renewable energy sources. Respondents also showed significant support for nuclear energy and expected government support programs for activities related to energy conservation. The survey shall be repeated on a random sample at the time when the energy price changes caused by the transformation of the energy mix occur—i.e., around 2025.

Promoting the Solar Industry in Ghana through Effective Public-Private Partnership (PPP): Some Lessons from South Africa and Morocco

Over the past decades, solar energy has gained much attention in Ghana, especially after the 2012–2016 power crisis. The government through Public-Private Partnerships (PPPs) has attempted to increase the shares of solar generation to augment its efforts in reducing the energy deficit of the country, especially in remote and off-grid communities. However, the extent to which PPP has been utilized as a viable tool for solar sector development in Ghana is questionable. This study discusses the current state of PPPs in Ghana’s solar industry and compares how it has been efficiently used as a tool to promote the solar industry in South Africa and Morocco. Fundamental theories such as Altruism, Game, Principal-agent, and Pareto Optimality (PO) were used as analytical tools to examine how PPPs are handled in the selected cases. The study ascertains that the Game and PO are applicable theories that have guided SA and Morocco’s solar infrastructural development. This study discovered that PPP has been efficiently used in SA and Morocco to push its solar industry to be among the best in the world and Ghana can perfectly emulate it. The study further reveals that the Principal-agent analogy and altruistic intent of the Ghanaian government tend to discourage Private sector participation in the solar industry. It further suggests the Pareto Optimality, Game approach, and a win-win transparent attitude towards PPPs. This study recommends a well-developed PPP structure and law for Ghana. It encourages transparency and discourages partisan preferentialism to increase PPPs in Ghana’s solar industry.

Nutrients to Improve Mitochondrial Function to Reduce Brain Energy Deficit and Oxidative Stress in Migraine

The mechanisms of migraine pathogenesis are not completely clear, but 31P-nuclear magnetic resonance studies revealed brain energy deficit in migraineurs. As glycolysis is the main process of energy production in the brain, mitochondria may play an important role in migraine pathogenesis. Nutrition is an important aspect of migraine pathogenesis, as many migraineurs report food-related products as migraine triggers. Apart from approved anti-migraine drugs, many vitamins and supplements are considered in migraine prevention and therapy, but without strong supportive evidence. In this review, we summarize and update information about nutrients that may be important for mitochondrial functions, energy production, oxidative stress, and that are related to migraine. Additionally, we present a brief overview of caffeine and alcohol, as they are often reported to have ambiguous effects in migraineurs. The nutrients that can be considered to supplement the diet to prevent and/or ameliorate migraine are riboflavin, thiamine, magnesium ions, niacin, carnitine, coenzyme Q10, melatonin, lipoic acid, pyridoxine, folate, and cobalamin. They can supplement a normal, healthy diet, which should be adjusted to individual needs determined mainly by the physiological constitution of an organism. The intake of caffeine and alcohol should be fine-tuned to the history of their use, as withdrawal of these agents in regular users may become a migraine trigger.