scholarly journals Trapping horizon and negative energy

2019 ◽  
Vol 2019 (6) ◽  
Author(s):  
Pei-Ming Ho ◽  
Yoshinori Matsuo
1997 ◽  
Vol 78 (5) ◽  
pp. 805-813 ◽  
Author(s):  
Kjell Holtenius ◽  
Paul Holtenius

The metabolic effects of a phlorizin-induced drainage of glucose were studied in six lactating ewes with or without peroral alanine drenches in a study of crossover design. Phlorizin gave rise to a small, but significant, elevation of plasma β-hydroxybutyrate. The plasma level of alanine decreased by about 30 % due to the phlorizin injections and alanine was negatively correlated to β-hydroxybutyrate. The plasma level of free fatty acids increased due to phlorizin. Plasma insulin and glucose concentrations were not significantly affected by phlorizin while glucagon level showed a small but significant increase. Peroral alanine drenches to phlorizin-treated ewes gave rise to a transitory elevation of alanine in plasma. The plasma level of free fatty acids was about 40 % lower in phlorizin-treated ewes receiving alanine and β-hydroxybutyrate tended to be lower (P < 0.08). We suggest that β-hydroxybutyrate, apart from its function as an oxidative fuel, might play an important role by limiting glucose oxidation and protein degradation in skeletal muscles during periods of negative energy balance in ruminants. Furthermore, it is suggested that alanine supplementation decreases lipolysis and ketogenesis in lactating ewes.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 309
Author(s):  
Deise Aline Knob ◽  
André Thaler Neto ◽  
Helen Schweizer ◽  
Anna C. Weigand ◽  
Roberto Kappes ◽  
...  

Crossbreeding in dairy cattle has been used to improve functional traits, milk composition, and efficiency of Holstein herds. The objective of the study was to compare indicators of the metabolic energy balance, nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, body condition score (BCS) back fat thickness (BFT), as well as milk yield and milk composition of Holstein and Simmental cows, and their crosses from the prepartum period until the 100th day of lactation at the Livestock Center of the Ludwig Maximilians University (Munich, Germany). In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; n = 9), R1-Hol (51–99% Holstein; n = 30), first generation (F1) crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). The study took place between April 2018 and August 2019. BCS, BFT blood parameters, such as BHBA, glucose, and NEFA were recorded weekly. A mixed model analysis with fixed effects breed, week (relative to calving), the interaction of breed and week, parity, calving year, calving season, milking season, and the repeated measure effect of cow was used. BCS increased with the Simmental proportion. All genetic groups lost BCS and BFT after calving. Simmental cows showed lower NEFA values. BHBA and glucose did not differ among genetic groups, but they differed depending on the week relative to calving. Simmental and R1-Sim cows showed a smaller effect than the other genetic groups regarding changes in body weight, BCS, or back fat thickness after a period of a negative energy balance after calving. There was no significant difference for milk yield among genetic groups, although Simmental cows showed a lower milk yield after the third week after calving. Generally, Simmental and R1-Simmental cows seemed to deal better with a negative energy balance after calving than purebred Holstein and the other crossbred lines. Based on a positive heterosis effect of 10.06% for energy corrected milk (ECM), the F1, however, was the most efficient crossbred line.


2021 ◽  
Vol 13 (14) ◽  
pp. 7713
Author(s):  
Juan De Dios Benítez-Sillero ◽  
Luis Manuel Martínez-Aranda ◽  
Manuel Sanz-Matesanz ◽  
Marta Domínguez-Escribano

Within the determining factors of psychological performance, mental toughness is considered a multidimensional factor, comprising cognitive, affective, and behavioural components together with self-confidence, which is related to success in sports performance as well as psychological health and well-being. The aim of this study was to analyse the relationship between different factors composing mental toughness and age categories in young football players, in order to determine the presence of specific psychological skills in their formative progression. A total of 118 male players (16.91 ± 2.42 years old) completed the Spanish version by Cernuda (1988) of the original Psychological Performance Inventory (PPI) by Loher (1982, 1986). The results indicated significant differences in four variables (negative energy control, attention control, visual and image control, motivational level) on three different age categories, where the U19 category showed the best results for all the variables, decreasing afterwards in the semi-professional category. Significant correlations were established between mental toughness variables and age categories, where the age category variable was significantly correlated in a positive way with attention control, visual and image control, and motivational level. In the same line, the variable self-confidence correlated positively with negative energy control, attention control, motivational level, attention control, and positive energy. The assessment of psychological variables such as mental toughness, taking into account the formative stage, may be helpful for both coaches and players when selecting adequate mental skill training for improving competitive performance and sporting success, as well as for positive and healthy psychological development and well-being.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 303
Author(s):  
Lingdi Tang ◽  
Shouqi Yuan ◽  
Yue Tang ◽  
Zhijun Gao

The impulse water turbine is a promising energy conversion device that can be used as mechanical power or a micro hydro generator, and its application can effectively ease the current energy crisis. This paper aims to clarify the mechanism of liquid acting on runner blades, the hydraulic performance, and energy conversion characteristics in the runner domain of an impulse water turbine with a splitter blade by using experimental tests and numerical simulations. The runner was divided into seven areas along the flow direction, and the power variation in the runner domain was analyzed to reflect its energy conversion characteristics. The obtained results indicate that the critical area of the runner for doing the work is in the front half of the blades, while the rear area of the blades does relatively little work and even consumes the mechanical energy of the runner to produce negative work. The high energy area is concentrated in the flow passage facing the nozzle. The energy is gradually evenly distributed from the runner inlet to the runner outlet, and the negative energy caused by flow separation with high probability is gradually reduced. The clarification of the energy conversion performance is of great significance to improve the design of impulse water turbines.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Vengala Rao Yenuganti ◽  
Dirk Koczan ◽  
Jens Vanselow

Abstract Background Metabolic stress, as negative energy balance on one hand or obesity on the other hand can lead to increased levels of free fatty acids in the plasma and follicular fluid of animals and humans. In an earlier study, we showed that increased oleic acid (OA) concentrations affected the function of cultured bovine granulosa cells (GCs). Here, we focus on genome wide effects of increased OA concentrations. Results Our data showed that 413 genes were affected, of which 197 were down- and 216 up-regulated. Specifically, the expression of FSH-regulated functional key genes, CCND2, LHCGR, INHA and CYP19A1 and 17-β-estradiol (E2) production were reduced by OA treatment, whereas the expression of the fatty acid transporter CD36 was increased and the morphology of the cells was changed due to lipid droplet accumulation. Bioinformatic analysis revealed that associated pathways of the putative upstream regulators “FSH” and “Cg (choriogonadotropin)” were inhibited and activated, respectively. Down-regulated genes are over-represented in GO terms “reproductive structure/system development”, “ovulation cycle process”, and “(positive) regulation of gonadotropin secretion”, whereas up-regulated genes are involved in “circulatory system development”, “vasculature development”, “angiogenesis” or “extracellular matrix/structure organization”. Conclusions From these data we conclude that besides inhibiting GC functionality, increased OA levels seemingly promote angiogenesis and tissue remodelling, thus suggestively initiating a premature fulliculo-luteal transition. In vivo this may lead to impeded folliculogenesis and ovulation, and cause sub-fertility.


Proceedings ◽  
2020 ◽  
Vol 73 (1) ◽  
pp. 9
Author(s):  
Deise Aline Knob ◽  
André Thaler Neto ◽  
Helen Schweizer ◽  
Anna Weigand ◽  
Roberto Kappes ◽  
...  

Depending on the breed or crossbreed line, cows have to cope with a more or less severe negative energy balance during the period of high milk yields in early lactation, which can be detected by beta-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFAs) in blood. Preventing cows from undergoing a severe negative energy balance by breeding and/or feeding measures is likely to be supported by the public and may help to improve the sustainability of milk production. The aim was to compare BHBA and NEFA concentrations in the blood of Holstein and Simmental cows and their crosses during the prepartum period until the end of lactation. In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; n = 9), R1-Hol (51–99% Holstein; n = 30), F1 crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). NEFA and BHBA were evaluated once a week between April 2018 and August 2019. A mixed model analysis with fixed effects breed, week (relative to calving), the interaction of breed and week, parity, calving year, calving season, milking season, and the repeated measure effect on cows was used. Holstein cows had higher NEFAs (0.196 ± 0.013 mmol/L), and Simmental cows had the lowest NEFA concentrations (0.147 ± 0.008 mmol/L, p = 0.03). R1-Sim, F1 and R1-Hol cows had intermediate values (0.166 ± 0.005, 0.165 ± 0.010, 0.162 ± 0.008 mmol/L; respectively). The highest NEFA value was found in the first week after calving (0.49 ± 0.013 mmol/L). BHBA did not differ among genetic groups (p = 0.1007). There was, however, an interaction between the genetic group and week (p = 0.03). While Simmental, R1-Sim and F1 cows had the highest BHBA value, the second week after calving (0.92 ± 0.07 and 1.05 ± 0.04, and 1.10 ± 0.10 mmol/L, respectively), R1-Hol and Holstein cows showed the BHBA peak at the fourth week after calving (1.16 ± 0.07 and 1.36 ± 0.12 mmol/L, respectively). Unexpectedly, Holstein cows had a high BHBA peak again at week 34 after calving (1.68 ± 0.21 mmol/L). The genetic composition of the cows affects NEFA and BHBA. Simmental and R1-Sim cows mobilize fewer body reserves after calving. Therefore, dairy cows with higher degrees of Simmental origin might be more sustainable in comparison with Holstein genetics in the present study.


Diabetologia ◽  
2021 ◽  
Author(s):  
Wilma S. Leslie ◽  
Eman Ali ◽  
Leanne Harris ◽  
C. Martina Messow ◽  
Naomi T. Brosnahan ◽  
...  

Abstract Aims/hypothesis Our aim was to evaluate the safety and efficacy of a planned therapeutic withdrawal of all antihypertensive and diuretic medications, on commencing a formula low-energy diet replacement, targeting remission of type 2 diabetes. Methods Post hoc analysis of changes in BP, antihypertensive medication prescriptions and symptoms during the initial total diet replacement phase was performed in the intervention arm of the Diabetes Remission Clinical Trial (n = 143) and in the subset (n = 69) who discontinued antihypertensive medications at the start of total diet replacement. The Counterweight-Plus total diet replacement provided about 3470 kJ/day (830 kcal) with automatic reductions in all nutrients, including sodium, to achieve marked negative energy balance and rapid weight loss over 12–20 weeks, with regular BP monitoring and an antihypertensive reintroduction protocol based on current clinical guidelines. Results Of 143 intervention group participants who commenced total diet replacement, 78 (55%) were on treatment for hypertension at baseline. The overall mean BP fell significantly from the start of total diet replacement (week 1) and was significantly lower at week 20, after total diet replacement finished, and also at 12 and 24 months. Of the 78 participants previously on treatment for hypertension, 65 (83%) stopped all antihypertensive and diuretic medications as per protocol, and four (5%) stopped some drugs. These 69 participants experienced no immediate (within the first week) change in BP, but their mean BP fell significantly from 9 weeks. No excessive rises in BP were recorded in individuals, but antihypertensive medications were reintroduced during total diet replacement to manage raised BP for 19/69 (27.5%) participants, mostly within the first 3–7 weeks, despite some weight loss. Reintroduction of antihypertensive medications was necessary for 5/19 participants previously on one drug, and for 14/19 previously on two or more drugs. Of the 69 who stopped antihypertensives, 19 (28%) remained off medications at 24 months. Among the 53 participants who achieved sustained remissions of diabetes at 24 months (with a mean weight loss of 11.4 kg), 31 had been previously treated for hypertension. Twenty-seven stopped medication at baseline, and 15/27 required reintroduction of antihypertensive medications. Mild to moderate dizziness, suggesting some postural hypotension, was reported during total diet replacement by 51 participants, 15 of whom had recorded dizziness at baseline prior to starting total diet replacement, with nine of these on antihypertensive or diuretic medications. Conclusions/interpretation Replacing antihypertensive medications with a 3470 kJ/day (830 kcal) diet to induce weight loss reduces BP substantially and may increase mild dizziness. It is safe to stop antihypertensives, but BP should be monitored regularly, particularly for those taking two or more antihypertensives, as over two-thirds will require reintroduction of some medications. Long-term support to maintain weight loss is vital. Trial registration ISRCTN registry, number 03267836. Graphical abstract


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