Статті в журналах: "Gain en puissance maximal"

1

Dekerle, Jeanne, Bertrand Baron, L. Dupont, Jacques Vanvelcenaher, H. Robin, and P. Pelayo. "Puissance critique, seuils ventilatoires et état stable maximal de la lactatémie." Les Cahiers de l'INSEP 33, no. 1 (2002): 203–13. http://dx.doi.org/10.3406/insep.2002.1698.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

RÖSCH, FELIX. "Pouvoir,puissance, and politics: Hans Morgenthau's dualistic concept of power?" Review of International Studies 40, no. 2 (April 23, 2013): 349–65. http://dx.doi.org/10.1017/s0260210513000065.

Повний текст джерела

Анотація:

AbstractHans Morgenthau's concept of power is widely debated among scholars of International Relations. Superficial accounts present Morgenthau's concept of power in the Hobbesian tradition as a means of self-preservation; however, more thorough investigations demonstrate Morgenthau's psychogenic and praxeological understanding. By referring to Sigmund Freud and Max Weber, such accounts identify Morgenthauian power as the ability to dominate others. This article contributes to this discourse by demonstrating that Morgenthau separated power into two dualistic conceptualisations. Although analytically Morgenthau worked with a concept of power understood as domination, normatively – in reference to Friedrich Nietzsche and Hannah Arendt – he promoted a concept of power that focused on the will and ability to act together. Elaborating this dualistic concept has wider implications for current International Relations because it reminds scholars to be self-reflexive. In addition, it is argued that a Morgenthauian scholarship helps scholars to gain a more profound understanding of depoliticising tendencies in Western democracies.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Arsénio, Diogo, and Nader Masmoudi. "Maximal gain of regularity in velocity averaging lemmas." Analysis & PDE 12, no. 2 (January 1, 2019): 333–88. http://dx.doi.org/10.2140/apde.2019.12.333.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Geiselhart, Roman, and Fabian Wirth. "On Maximal Gains Guaranteeing a Small-Gain Condition." SIAM Journal on Control and Optimization 53, no. 1 (January 2015): 262–86. http://dx.doi.org/10.1137/130924755.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Frolov, Andrei N. "On asymptotics of the maximal gain without losses." Statistics & Probability Letters 63, no. 1 (May 2003): 13–23. http://dx.doi.org/10.1016/s0167-7152(02)00420-0.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Pan, Yijin, Cunhua Pan, Zhaohui Yang, Ming Chen, and Jiangzhou Wang. "A Caching Strategy Towards Maximal D2D Assisted Offloading Gain." IEEE Transactions on Mobile Computing 19, no. 11 (November 1, 2020): 2489–504. http://dx.doi.org/10.1109/tmc.2019.2933843.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Frolov, Andrei, Alexander Martikainen, and Josef Steinebach. "Strong laws for the maximal gain over increasing runs." Statistics & Probability Letters 50, no. 3 (November 2000): 305–12. http://dx.doi.org/10.1016/s0167-7152(00)00119-x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Rocher, P., and C. Cavelier. "Production d'éléments orbitaux de comètes sur PC." Symposium - International Astronomical Union 172 (1996): 357–60. http://dx.doi.org/10.1017/s0074180900127688.

Повний текст джерела

Анотація:

La puissance de calcul des ordinateurs PC actuels permet leur utilisation pour des travaux qui étaient, jusqu'à ces dernières années, effectués exclusivement sur de gros ordinateurs. Le mode interactif utilisé pour la gestion et la saisie des données, facilement mis en œuvre sur les PC, permet un gain de temps important par rapport au travail classique en traitement par lot (batch). Nous présentons ici un logiciel PC, permettant le calcul et l'amélioration des éléments orbitaux des comètes. Une bonne connaissance de ces éléments est indispensable pour le calcul des éphémérides, notamment pour la redécouverte des comètes périodiques.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Piskorski, Ł., L. Frasunkiewicz, and R. P. Sarzała. "Comparative analysis of GaAs- and GaSb-based active regions emitting in the mid-infrared wavelength range." Bulletin of the Polish Academy of Sciences Technical Sciences 63, no. 3 (September 1, 2015): 597–603. http://dx.doi.org/10.1515/bpasts-2015-0070.

Повний текст джерела

Анотація:

Abstract In the present paper the results of the computer analysis of the GaAs-based and GaSb-based active regions that can be applied in compact semiconductor laser sources of radiation at mid-infrared wavelengths are presented. Quantum well material contents and strain dependencies on the maximal gain are investigated. It is shown that above 3 μm the maximal gain obtained for GaInNAs/AlGaInAs active region is high only for thick, highly-strained GaInNAs QWs with N concentration higher than 2%. Much higher gain in this wavelength range can be obtained for GaInAsSb/AlGaAsSb active region, which offers relatively high gain even at 4.5 μm when the Sb content in GaInAsSb and compressive strain in this layer are equal to 50% and − 2%, respectively.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Richard, Lenaïg, Pierre-Philippe Blanc, Vincent Rigolet, Sadasivam J. Kaushik, and Inge Geurden. "Maintenance and growth requirements for nitrogen, lysine and methionine and their utilisation efficiencies in juvenile black tiger shrimp, Penaeus monodon, using a factorial approach." British Journal of Nutrition 103, no. 7 (November 30, 2009): 984–95. http://dx.doi.org/10.1017/s0007114509992844.

Повний текст джерела

Анотація:

We used a factorial approach to distinguish maintenance from growth requirements for protein, lysine and methionine in the black tiger shrimp, Penaeus monodon. Juvenile P. monodon (initial weight 2·4 g) were fed during 6 weeks one of ten semi-purified diets based on casein and purified amino acids (AA) as N source. The diets contained four levels of crude protein (CP, from 5 to 54 % DM diet) with two levels (% CP) of lysine or methionine (normal or 30 % deficient). Requirements were determined using linear and non-linear regression models. We could thus obtain the first ever data on maintenance (N equilibrium) requirements for CP and AA in P. monodon. CP requirements for maintenance (4·5 g/kg body weight (BW) per d) represented approximately 19 % of the CP requirement for maximal N gain (23·9 g/kg BW per d). The marginal efficiency of utilisation reached a maximum of 38 % for N, 0·77 for lysine and 1·62 for methionine using N gain as response. Lysine requirements were 0·20 g/kg BW per d for N maintenance and 1·40 g/kg BW per d for maximal N gain. Methionine requirements were 0·11 g/kg BW per d for N maintenance and 0·70 g/kg BW per d for maximal N gain. The lysine (5·8 %) and methionine (2·9 %) requirements for maximal N gain, expressed as percentage of protein requirement, agree with literature data using a dose–response technique with smaller P. monodon. The observed interaction between dietary CP and methionine for N gain demonstrates that requirements for indispensable AA (expressed as % CP) cannot be evaluated separately from CP requirements.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

S., Soulayman. "Dual Axis and Single Axis Sun Tracking Maximal Energy Gain." Energy Research 1, no. 1 (2017): 22. http://dx.doi.org/10.31058/j.er.2017.11003.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Tuzlukov, V. P. "DIVERSITY SIGNAL PROCESSING OVER WEIBULL FADING CHANNELS." Doklady BGUIR, no. 7-8 (December 29, 2019): 13–21. http://dx.doi.org/10.35596/1729-7648-2019-126-8-13-21.

Повний текст джерела

Анотація:

We present a moments-based approach to the performance analysis of L-branch equal-gain combining and maximal-ratio combining receivers, operating in independent or correlated, not necessarily identically distributed, Weibull fading. For both equal-gain combining and maximal-ratio combining receivers the moments of the output signal-to-noise ratio are obtained in closed-form. An accurate approximate expression is derived for the moment-generating function of the output signal-to-noise ratio of the equal-gain combining receiver utilizing the Padé approximants theory, while a closed-form expression for the corresponding MGF of the maximal-ratio combining receiver, is obtained. Significant performance criteria, such as average output signal-to-noise ratio, amount of fading and spectral efficiency at the low power regime, are extracted in closed-forms, using the moments of the output signal-to-noise ratio for both independent and correlative fading. Moreover, using the well-known moment-generating function approach, the outage and the average symbol error probability for several coherent, non-coherent, binary, and multilevel modulation schemes, are studied. The average symbol error probability of dual-branch equal-gain combining and maximal-ratio combining receivers is also obtained when correlative fading is considered in the diversity input branches. The proposed mathematical analysis is illustrated by various numerical results and validated by computer simulations.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Yquel, R. J., L. M. Arsac, E. Thiaudière, P. Canioni, and G. Manier. "Effets de l'ingestion de créatine sur la puissance musculaire pendant un exercice maximal intermittent : une étude en RMN 31P." Science & Sports 17, no. 3 (May 2002): 143–45. http://dx.doi.org/10.1016/s0765-1597(02)00144-2.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Hoshino, Osamu. "Balanced Crossmodal Excitation and Inhibition Essential for Maximizing Multisensory Gain." Neural Computation 26, no. 7 (July 2014): 1362–85. http://dx.doi.org/10.1162/neco_a_00606.

Повний текст джерела

Анотація:

We examined whether and how the balancing of crossmodal excitation and inhibition affects intersensory facilitation. A neural network model, comprising lower-order unimodal networks (X, Y) and a higher-order multimodal network (M), was simulated. Crossmodal excitation was made by direct activation of principal cells of the X network by the Y network. Crossmodal inhibition was made in an indirect manner: the Y network activated glial cells of the X network. This let glial plasma membrane transporters export GABA molecules into the extracellular space and increased the level of ambient GABA. The ambient GABA molecules were accepted by extrasynaptic GABAa receptors and tonically inhibited principal cells of the X network. Namely, crossmodal inhibition was made through GABAergic gliotransmission. Intersensory facilitation was assessed in terms of multisensory gain: the difference between the numbers of spikes evoked by multisensory (XY) stimulation and unisensory (X-alone) stimulation. The maximal multisensory gain (XY-X) could be achieved at an intermediate noise level by balancing crossmodal excitation and inhibition. This result supports an experimentally derived conclusion: intersensory facilitation under noisy environmental conditions is not necessarily in accord with the principle of inverse effectiveness; rather, multisensory gain is maximal at intermediate signal-to-noise ratio (SNR) levels. The maximal multisensory gain was available at the weakest signal if noise was not present, indicating that the principle of inverse effectiveness is a special case of the intersensory facilitation model proposed here. We suggest that the balancing of crossmodal excitation and inhibition may be crucial for intersensory facilitation. The GABAergic glio-transmission-mediated crossmodal inhibitory mechanism effectively works for intersensory facilitation and on determining the maximal multisensory gain in the entire SNR range between the two extremes: low and high SNRs.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Karagiannidis, G. K., D. A. Zogas, N. C. Sagias, S. A. Kotsopoulos, and G. S. Tombras. "Equal-gain and maximal-ratio combining over nonidentical Weibull fading channels." IEEE Transactions on Wireless Communications 4, no. 3 (May 2005): 841–46. http://dx.doi.org/10.1109/twc.2005.846982.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Altimiras, Jordi, and Dane A. Crossley. "Control of blood pressure mediated by baroreflex changes of heart rate in the chicken embryo (Gallus gallus)." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 278, no. 4 (April 1, 2000): R980—R986. http://dx.doi.org/10.1152/ajpregu.2000.278.4.r980.

Повний текст джерела

Анотація:

Pharmacological manipulation of peripheral resistance via sodium nitroprusside and phenylephrine was used to study baroreflex function over the latter two-thirds of incubation in embryonic chickens. From day 9 to day 19of incubation, there is a positive linear relation between heart rate and blood pressure, indicating the feedforward action of arterial pressure on heart rate. A reciprocal relationship between blood pressure and heart rate became pronounced during the last 3 days of incubation. For the purpose of the study, gain of the baroreflex was calculated as maximal gain (only those embryos that demonstrated the response) or average gain (all embryos). Maximal gain increased progressively from 13 ± 7 beats ⋅ min−1 ⋅ kPa−1at 18 days to 105 ± 83 beats ⋅ min−1 ⋅ kPa−1in 2-day-old hatchlings. The percentage of embryos older than 18 days with baroreflex responses increased from 33% on day 19 to 56% on day 21, indicating that baroreflex regulation begins late in incubation (∼90% incubation time), and the gain of this reflex exhibits a maturation over the final 3 days of incubation.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

FANG, JIAN, YUAN LU, PENG HUANG, GUANGQIANG HE, and GUIHUA ZENG. "DISCRETELY MODULATED CONTINUOUS-VARIABLE QUANTUM KEY DISTRIBUTION WITH A NONDETERMINISTIC NOISELESS AMPLIFIER." International Journal of Quantum Information 11, no. 04 (June 2013): 1350037. http://dx.doi.org/10.1142/s0219749913500378.

Повний текст джерела

Анотація:

In this paper, we first study a generalized protocol of discrete modulation for continuous-variable quantum key distribution with N coherent states in a Gaussian lossy and noisy channel and investigate its performance against collective attacks. We find that discrete modulation protocols with more than eight states do not perform better than the eight-state protocol. Then, we study the improvement of this protocol by using a nondeterministic noiseless linear amplifier (NLA) on Bob's detection stage. Results indicate that a NLA with gain g can extend the maximum transmission distance by 50 log 10g2 km and can increase the maximal tolerable excess noise. With the reconciliation efficiency β, we find the gain of NLA has a maximal value defined as g max and by adjusting the gain to about βg max one can have the best improvement on secret key rate.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Zhao, Shilei, Wanchun Chen, and Liang Yang. "Optimal Guidance Law with Impact-Angle Constraint and Acceleration Limit for Exo-Atmospheric Interception." Aerospace 8, no. 12 (November 23, 2021): 358. http://dx.doi.org/10.3390/aerospace8120358.

Повний текст джерела

Анотація:

This paper aims to develop an optimal guidance law for exo-atmospheric interception, in which impact-angle constraint and acceleration limit are considered. Firstly, an optimal control problem with constraints on terminal miss and impact-angle is formulated, in which the control energy performance index is weighted by a power function of the time-to-go. The closed-loop guidance command, which is expressed as a linear combination of zero-effort miss distance and the zero-effort angle error, is derived using a traditional order reduction transformation. Then, an analytical solution to the maximal acceleration during the flight is obtained by analyzing the boundary points and critical points of the guidance command curve. It is found that the maximal acceleration is a function of the weighted gain in the performance index. Therefore, the maximal acceleration can be efficiently limited by using the variable weighted gain. Furthermore, the relationship between the total control energy and the weighted gain is studied. As a result, a systematic method is proposed for selecting the weighted gain so as to meet the constraint of the acceleration while the total control energy is minimal. Nonlinear simulations have been carried out to test the performance of the proposed method. The results show that this method performs well in intercepting the maneuvering target with a negligible miss distance and intercept angle error. And it can tolerate a stricter acceleration limit in comparison with the typical method.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Yacoub, M. D., C. R. C. M. da Silva, and J. E. Vargas B. "Second-order statistics for equal gain and maximal ratio diversity-combining reception." Electronics Letters 36, no. 4 (2000): 382. http://dx.doi.org/10.1049/el:20000288.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

AAGAARD, ESBEN, CLAUS DONSLUND, ANN WENZEL, and IB SEWERIN. "Performance for obtaining maximal gain from a program for digital subtraction radiography." European Journal of Oral Sciences 99, no. 2 (April 1991): 166–72. http://dx.doi.org/10.1111/j.1600-0722.1991.tb01880.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

21

O'Hagan, Kathleen P., Kara A. Skogg, and Jennifer B. Stevenson. "AT1 receptor block does not affect arterial baroreflex during pregnancy in rabbits." American Journal of Physiology-Heart and Circulatory Physiology 280, no. 5 (May 1, 2001): H1996—H2005. http://dx.doi.org/10.1152/ajpheart.2001.280.5.h1996.

Повний текст джерела

Анотація:

The role of ANG II in the arterial baroreflex control of renal sympathetic nerve activity (RSNA) in eight term-pregnant (P) and eight nonpregnant (NP) conscious rabbits was assessed using sequential intracerebroventricular and intravenous infusions of losartan, an AT1 receptor antagonist. The blood pressure (BP)-RSNA relationship was generated by sequential inflations of aortic and vena caval perivascular occluders. Pregnant rabbits exhibited a lower maximal RSNA reflex gain (−44%) that was primarily due to a reduction in the maximal sympathetic response to hypotension (P, 248 ± 20% vs. NP, 357 ± 41% of rest RSNA, P < 0.05). Intracerebroventricular losartan decreased resting BP in P (by 9 ± 3 mmHg, P < 0.05) but not NP rabbits, and had no effect on the RSNA baroreflex in either group. Subsequent intravenous losartan decreased resting BP in NP and further decreased BP in P rabbits, but had no significant effect on the maximal RSNA reflex gain. ANG II may have an enhanced role in the tonic support of BP in pregnancy, but does not mediate the gestational depression in the arterial baroreflex control of RSNA in rabbits.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Drew, Rachel C., Cheryl A. Blaha, Michael D. Herr, Sean D. Stocker, and Lawrence I. Sinoway. "Healthy older humans exhibit augmented carotid-cardiac baroreflex sensitivity with aspirin during muscle mechanoreflex and metaboreflex activation." American Journal of Physiology-Heart and Circulatory Physiology 309, no. 8 (October 2015): H1361—H1369. http://dx.doi.org/10.1152/ajpheart.00444.2015.

Повний текст джерела

Анотація:

Low-dose aspirin inhibits thromboxane production and augments the sensitivity of carotid baroreflex (CBR) control of heart rate (HR) during concurrent muscle mechanoreflex and metaboreflex activation in healthy young humans. However, it is unknown how aging affects this response. Therefore, the effect of low-dose aspirin on carotid-cardiac baroreflex sensitivity during muscle mechanoreflex with and without metaboreflex activation in healthy older humans was examined. Twelve older subjects (6 men and 6 women, mean age: 62 ± 1 yr) performed two trials during two visits preceded by 7 days of low-dose aspirin (81 mg) or placebo. One trial involved 3 min of passive calf stretch (mechanoreflex) during 7.5 min of limb circulatory occlusion (CO). In another trial, CO was preceded by 1.5 min of 70% maximal voluntary contraction isometric calf exercise (mechanoreflex and metaboreflex). HR (ECG) and mean arterial blood pressure (MAP; Finometer) were recorded. CBR function was assessed using rapid neck pressure application (+40 to −80 mmHg). Aspirin significantly decreased baseline thromboxane B2 production by 83 ± 4% ( P < 0.05) but did not affect 6-keto-PGF1α. After aspirin, CBR-HR maximal gain and operating point gain were significantly higher during stretch with metabolite accumulation compared with placebo (maximal gain: −0.23 ± 0.03 vs. −0.14 ± 0.02 and operating point gain: −0.11 ± 0.03 vs. −0.04 ± 0.01 beats·min−1·mmHg−1 for aspirin and placebo, respectively, P < 0.05). In conclusion, these findings suggest that low-dose aspirin augments CBR-HR sensitivity during concurrent muscle mechanoreflex and metaboreflex activation in healthy older humans. This increased sensitivity appears linked to reduced thromboxane sensitization of muscle mechanoreceptors, which consequently improves CBR-HR control.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Cardelli, Luca, Mirco Tribastone, Max Tschaikowski, and Andrea Vandin. "Maximal aggregation of polynomial dynamical systems." Proceedings of the National Academy of Sciences 114, no. 38 (September 6, 2017): 10029–34. http://dx.doi.org/10.1073/pnas.1702697114.

Повний текст джерела

Анотація:

Ordinary differential equations (ODEs) with polynomial derivatives are a fundamental tool for understanding the dynamics of systems across many branches of science, but our ability to gain mechanistic insight and effectively conduct numerical evaluations is critically hindered when dealing with large models. Here we propose an aggregation technique that rests on two notions of equivalence relating ODE variables whenever they have the same solution (backward criterion) or if a self-consistent system can be written for describing the evolution of sums of variables in the same equivalence class (forward criterion). A key feature of our proposal is to encode a polynomial ODE system into a finitary structure akin to a formal chemical reaction network. This enables the development of a discrete algorithm to efficiently compute the largest equivalence, building on approaches rooted in computer science to minimize basic models of computation through iterative partition refinements. The physical interpretability of the aggregation is shown on polynomial ODE systems for biochemical reaction networks, gene regulatory networks, and evolutionary game theory.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Chen, Q. C., D. Cain, and P. H. Jen. "Sound pressure transformation at the pinna of Mus domesticus." Journal of Experimental Biology 198, no. 9 (September 1, 1995): 2007–23. http://dx.doi.org/10.1242/jeb.198.9.2007.

Повний текст джерела

Анотація:

Sound pressure transformation properties at the pinna of laboratory mice Mus domesticus were studied by measuring the sound pressure level of a continuous tone at a series of frequencies at the tympanic membrane as a function of the position of a sound source under free-field stimulation conditions. The spectral transformation, the interaural spectral difference, the isopressure contours and the interaural pressure difference contours were plotted. Sound pressure transformation functions showed some prominent spectral notches throughout the frequency range tested (10-80 kHz). However, the notch frequency did not appear to be systematically related to sound direction. The study of interaural pressure difference demonstrated that, when delivered from some angles within the ipsilateral frontal hemisphere, the sound pressure at the tympanic membrane of certain frequencies may be lower than that determined at the corresponding contralateral angles. For each sound frequency tested, there was an angle (the acoustic axis) within the ipsilateral frontal hemisphere from which the delivered sound reached a maximal pressure level at the tympanic membrane. However, the acoustic axis often changed to a new angle after removal of the ipsilateral pinna. In addition, sound delivered from the acoustic axis did not always generate a maximal pressure transformation. The isopressure contours determined within 2-5 dB of the maximal pressure were circumscribed, and their contained angular areas were found to decrease with increasing sound frequency. The 2 dB maximal pressure area may appear at more than one angular area for some test frequencies. Removal of the ipsilateral pinna or modification of pinna posture expanded isopressure contours irregularly and split the 2 dB maximal pressure area into several parts. The sound pressure difference determined between the angles of maximal and minimal sound pressure (the maximal directionality) increased with sound frequency regardless of pinna posture. Acoustic gain of the pinna at the acoustic axis reached 6-12 dB, depending upon sound frequency. However, the pinna gain was not always maximal at the acoustic axis for a given frequency.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Xu, Ling, John P. Collister, John W. Osborn, and Virginia L. Brooks. "Endogenous ANG II supports lumbar sympathetic activity in conscious sodium-deprived rats: role of area postrema." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 275, no. 1 (July 1, 1998): R46—R55. http://dx.doi.org/10.1152/ajpregu.1998.275.1.r46.

Повний текст джерела

Анотація:

This study tests the hypothesis that the area postrema (AP) is necessary for endogenous ANG II to chronically maintain lumbar sympathetic nerve activity (LSNA) and heart rate (HR) in conscious sodium-deprived rats. The effect of the ANG II type 1-receptor antagonist, losartan, on LSNA and HR was determined in rats that were either AP lesioned (APX) or sham lesioned. The sham rats were divided into groups, with (SFR) or without (SAL) food restriction, to control for the decreased food intake of APX rats. Before losartan, basal mean arterial pressure (MAP), HR, and baroreflex control of LSNA and HR were similar between groups, with the exception of lower maximal reflex LSNA and higher maximal gain of the HR-MAP curve in APX rats. In all groups, losartan similarly shifted ( P < 0.01) the LSNA-MAP curve to the left without altering maximal gain. Losartan also decreased ( P < 0.05) minimal LSNA in all groups, and suppressed ( P < 0.01) maximal LSNA (% of control) in SFR (240 ± 13 to 205 ± 15) and SAL (231 ± 21 to 197 ± 26) but not APX (193 ± 10 to 185 ± 8) rats. In general, losartan similarly shifted the HR-MAP curve to a lower MAP in all groups. The results suggest that the AP is not necessary for endogenous ANG II to chronically support LSNA and HR at basal and elevated MAP levels in sodium-deprived rats. However, the AP is required for endogenous ANG II to increase maximal reflex LSNA at low MAP levels.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Potts, J. T., X. Shi, and P. B. Raven. "Cardiopulmonary baroreceptors modulate carotid baroreflex control of heart rate during dynamic exercise in humans." American Journal of Physiology-Heart and Circulatory Physiology 268, no. 4 (April 1, 1995): H1567—H1576. http://dx.doi.org/10.1152/ajpheart.1995.268.4.h1567.

Повний текст джерела

Анотація:

Numerous studies have reported that, at rest, maximal carotid baroreflex gain is modulated by cardiopulmonary baroreceptors. The purpose of this study was to measure the maximal gain for carotid baroreflex control of heart rate (HR) and blood pressure [mean arterial pressure (MAP)] during dynamic exercise alone and when exercise was accompanied by two levels of cardiopulmonary baroreceptor unloading. Lower body negative pressure (LBNP) produced similar reductions in central venous pressure (CVP) at rest and during exercise. Baroreflex gain for HR at rest was not affected by low-level LBNP but was significantly increased by high-level LBNP [-0.31 +/- 0.05 to -0.57 +/- 0.23 beats.min-1.mmHg-1 carotid sinus pressure (CSP), no LBNP vs. high-level LBNP, P < 0.05]. Exercise combined with low- and high-level LBNP resulted in reflex HR gains (-0.83 +/- 0.44 and -0.83 +/- 0.17 beats.min-1.mmHg-1 CSP, low- vs. high-level LBNP, P < 0.05) that were significantly greater than the algebraic sum of the HR gain measured during exercise and LBNP alone. Neither exercise nor the two levels of LBNP significantly altered baroreflex gain for MAP. The slope relating HR gain to CVP at rest was significant (0.07 +/- 0.02 beats.min-1.mmHg CSP-1.mmHg CVP-1, P < 0.01) and increased 114% during exercise (P < 0.05). A similar analysis of MAP gain found no difference in slope between rest and exercise (P > 0.05). Together these data indicate 1) a tonic inhibitory interaction between cardiopulmonary baroreceptors and carotid baroreflex control of HR during exercise, and 2) a nonlinear relationship between deactivation of cardiopulmonary baroreceptors and changes in carotid baroreflex gain. This interaction may improve overall cardiovascular regulation when central blood volume and/or CVP is reduced, as has been reported during prolonged exercise in the heat.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Fraidenraich, G., J. C. S. Santos Filho, and M. D. Yacoub. "Second-order statistics of maximal-ratio and equal-gain combining in Hoyt fading." IEEE Communications Letters 9, no. 1 (January 2005): 19–21. http://dx.doi.org/10.1109/lcomm.2005.01012.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Fraidenraich, G., M. D. Yacoub, and J. C. S. Santos Filho. "Second-order statistics of maximal-ratio and equal-gain combining in Weibull fading." IEEE Communications Letters 9, no. 6 (2005): 499–501. http://dx.doi.org/10.1109/lcomm.2005.06001.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Fraidenraich, G., J. C. S. Santos Filho, and M. D. Yacoub. "Second-order statistics of maximal-ratio and equal-gain combining in hoyt fading." IEEE Communications Letters 9, no. 1 (January 2005): 19–21. http://dx.doi.org/10.1109/lcomm.2005.1375228.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Fraidenraich, G., M. D. Yacoub, and J. Candido S. Santos Filho. "Second-order statistics of maximal-ratio and equal-gain combining in Weibull fading." IEEE Communications Letters 9, no. 6 (June 2005): 499–501. http://dx.doi.org/10.1109/lcomm.2005.1437350.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Singh, Mr Prashant. "Improvement in Signal Quality with the use of Maximal Gain Combining Diversity Technique." International Journal of Engineering Trends and Technology 13, no. 3 (July 25, 2014): 101–2. http://dx.doi.org/10.14445/22315381/ijett-v13p221.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Yakushin, Sergei B., Theodore Raphan, and Bernard Cohen. "Gravity-Specific Adaptation of the Angular Vestibuloocular Reflex: Dependence on Head Orientation With Regard to Gravity." Journal of Neurophysiology 89, no. 1 (January 1, 2003): 571–86. http://dx.doi.org/10.1152/jn.00287.2002.

Повний текст джерела

Анотація:

The gain of the vertical angular vestibuloocular reflex (aVOR) was adaptively altered by visual-vestibular mismatch during rotation about an interaural axis, using steps of velocity in three head orientations: upright, left-side down, and right-side down. Gains were decreased by rotating the animal and visual surround in the same direction and increased by visual and surround rotation in opposite directions. Gains were adapted in one head position (single-state adaptation) or decreased with one side down and increased with the other side down (dual-state adaptation). Animals were tested in darkness using sinusoidal rotation at 0.5 Hz about an interaural axis that was tilted from horizontal to vertical. They were also sinusoidally oscillated from 0.5 to 4 Hz about a spatial vertical axis in static tilt positions from yaw to pitch. After both single- and dual-state adaptation, gain changes were maximal when the monkeys were in the position in which the gain had been adapted, and the gain changes progressively declined as the head was tilted away from that position. We call this gravity-specific aVOR gain adaptation. The spatial distribution of the specific aVOR gain changes could be represented by a cosine function that was superimposed on a bias level, which we called gravity-independent gain adaptation. Maximal gravity-specific gain changes were produced by 2–4 h of adaptation for both single- and dual-state adaptations, and changes in gain were similar at all test frequencies. When adapted while upright, the magnitude and distribution of the gravity-specific adaptation was comparable to that when animals were adapted in side-down positions. Single-state adaptation also produced gain changes that were independent of head position re gravity particularly in association with gain reduction. There was no bias after dual-state adaptation. With this difference, fits to data obtained by altering the gain in separate sessions predicted the modulations in gain obtained from dual-state adaptations. These data show that the vertical aVOR gain changes dependent on head position with regard to gravity are continuous functions of head tilt, whose spatial phase depends on the position in which the gain was adapted. From their different characteristics, it is likely that gravity-specific and gravity-independent adaptive changes in gain are produced by separate neural processes. These data demonstrate that head orientation to gravity plays an important role in both orienting and tuning the gain of the vertical aVOR.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Phomsoupha, M., J. Jeuvrey, and G. Laffaye. "RADIO-ULNAR PRONATION VS FOREARM EXTENSION: WHICH THE BEST TO REACH THE MAXIMAL BADMINTON RACKET VELOCITY?" Human Sport Medicine 20, no. 2 (July 14, 2020): 99–107. http://dx.doi.org/10.14529/hsm200212.

Повний текст джерела

Анотація:

Aim. Forearm extension and radio-ulnar pronation are two common components of the final movement during each badminton smash stroke. By coordinating the forearm to produce both extension and pronation at the same time, racket head velocity can be increased. Thus, this study examined maximal velocity and racket deflection during both movements in regard with skill level. Materials and methods. Twenty-two players (8 experts and 14 novices) participated in this study. Wrist, handle and racket head velocity were recorded using high speed cameras (Vicon V8i at a frequency of 250 Hz). Results. The racket head velocity with radio-ulnar pronation was 16 % higher than with forearm extension. This higher velocity resulted from an 8 % higher acceleration and a 70 % higher maximal angular velocity of the end points of the forearm segments during radio-ulnar pronation. In each movement, experts’ maximal velocity was higher than that of novices (p < .001).The maximal velocity of the racket for novices was obtained with elbow extension (20.9 ± 4.8 m/s), with a gain of 47 %, whereas for experts, it was obtained with radio-ulnar pronation (33.9 ± 5.8 m/s), with a gain of 53 %. Conclusion. The difference between the best velocities in both samples is 39 %, obtained respectively by radio-ulnar pronation for experts and an elbow extension for novices. Forearm extension and radio-ulnar pronation acceleration on the handle led to an increase in racket head velocity.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Ueberschlag-Pitiot, Vanessa, Amalia Stantzou, Julien Messéant, Megane Lemaitre, Daniel J. Owens, Philippe Noirez, Pauline Roy, Onnik Agbulut, Daniel Metzger, and Arnaud Ferry. "Gonad-related factors promote muscle performance gain during postnatal development in male and female mice." American Journal of Physiology-Endocrinology and Metabolism 313, no. 1 (July 1, 2017): E12—E25. http://dx.doi.org/10.1152/ajpendo.00446.2016.

Повний текст джерела

Анотація:

To better define the role of male and female gonad-related factors (MGRF, presumably testosterone, and FGRF, presumably estradiol, respectively) on mouse hindlimb skeletal muscle contractile performance/function gain during postnatal development, we analyzed the effect of castration initiated before puberty in male and female mice. We found that muscle absolute and specific (normalized to muscle weight) maximal forces were decreased in 6-mo-old male and female castrated mice compared with age- and sex-matched intact mice, without alteration in neuromuscular transmission. Moreover, castration decreased absolute and specific maximal powers, another important aspect of muscle performance, in 6-mo-old males, but not in females. Absolute maximal force was similarly reduced by castration in 3-mo-old muscle fiber androgen receptor (AR)-deficient and wild-type male mice, indicating that the effect of MGRF was muscle fiber AR independent. Castration reduced the muscle weight gain in 3-mo mice of both sexes and in 6-mo females but not in males. We also found that bone morphogenetic protein signaling through Smad1/5/9 was not altered by castration in atrophic muscle of 3-mo-old mice of both sexes. Moreover, castration decreased the sexual dimorphism regarding muscle performance. Together, these results demonstrated that in the long term, MGRF and FGRF promote muscle performance gain in mice during postnatal development, independently of muscle growth in males, largely via improving muscle contractile quality (force and power normalized), and that MGFR and FGRF also contribute to sexual dimorphism. However, the mechanisms underlying MGFR and FGRF actions remain to be determined.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Hietanen, M. A., N. A. Crowder, and M. R. Ibbotson. "Contrast Gain Control Is Drift-Rate Dependent: An Informational Analysis." Journal of Neurophysiology 97, no. 2 (February 2007): 1078–87. http://dx.doi.org/10.1152/jn.00991.2006.

Повний текст джерела

Анотація:

Neurons in the visual cortex code relative changes in illumination (contrast) and adapt their sensitivities to the visual scene by centering the steepest regions of their sigmoidal contrast response functions (CRFs: spike rate as a function of contrast) on the prevailing contrast. The influence of this contrast gain control has not been reported at nonoptimal drift rates. We calculated the Fisher information contained in the CRFs of halothane-anesthetized cats. Fisher information gives a measure of the accuracy of contrast representations based on the ratio of the square of the steepness of the CRF and the spike-rate dependency of the spiking variance. Variance increases with spike rate, so Fisher information is maximal where the CRF is steep and spike rates are low. Here, we show that the contrast at which the maximal Fisher information (CMFI) occurs for each adapting drift rate is at a fixed level above the adapting contrast. For adapting contrasts of 0 to 0.32 the relationship between CMFI and adapting contrast is well described by a straight line with a slope close to 1. The intercept of this line on the CMFI-axis is drift-rate dependent, although the slope is not. At high drift rates relative to each cell's peak the CMFI offset is higher than that for low drift rates. The results show that the contrast coding strategy in visual cortex maximizes accuracy for contrasts above the prevailing contrast in the environment for all drift rates. We argue that tuning the system for accuracy at contrasts above the prevailing value is optimal for viewing natural scenes.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

O’Hagan, Kathleen P., and Susan M. Casey. "Arterial baroreflex during pregnancy and renal sympathetic nerve activity during parturition in rabbits." American Journal of Physiology-Heart and Circulatory Physiology 274, no. 5 (May 1, 1998): H1635—H1642. http://dx.doi.org/10.1152/ajpheart.1998.274.5.h1635.

Повний текст джерела

Анотація:

The arterial baroreflex control of renal sympathetic nerve activity (RSNA) was evaluated in nine term pregnant (P) and 12 nonpregnant (NP) conscious New Zealand White rabbits. In an additional four P rabbits, the RSNA response to spontaneous parturition was measured. The blood pressure (BP)-RSNA relationship was generated by sequential inflations of aortic and vena caval perivascular occluders. Rest BP (P: 61 ± 2 vs. NP: 73 ± 2 mmHg) and the centering point of the baroreflex (P: 57 ± 2 vs. NP: 70 ± 2 mmHg) were lower ( P < 0.05) in term pregnancy. Baroreflex range (P: 246 ± 14% vs. NP 263 ± 24% of rest RSNA) was not affected by pregnancy. However, maximal reflex gain was moderately depressed (−44%) in P rabbits (P: −15 ± 1 vs. NP: −27 ± 4% of rest RSNA/mmHg; P < 0.05) due to a significant reduction in the slope coefficient. Delivery of a fetus was associated with strong renal sympathoexcitation. Peak RSNA averaged 80 ± 37% of smoke-elicited RSNA or 1,221 ± 288% of rest RSNA (mean ± SD). These results suggest that, in contrast to rat pregnancy, depressed arterial baroreflex control of RSNA in rabbit pregnancy is due primarily to a reduction in maximal gain rather than a reduction in the maximal sympathetic response to hypotension.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Baratta, R., and M. Solomonow. "Dynamic performance of a load-moving skeletal muscle." Journal of Applied Physiology 71, no. 2 (August 1, 1991): 749–57. http://dx.doi.org/10.1152/jappl.1991.71.2.749.

Повний текст джерела

Анотація:

The dynamic response of the tibialis anterior muscle of the cat was determined while it was subjected to sinusoidally varying orderly stimulation of motor units and to different isotonic loads in the range of 14–85% of the maximal isometric force. The dynamic response consisted of three major components: the displacement gain, the displacement attenuation, and a pure time delay. The displacement gain was dependent on the passive load applied to the muscle and the active force generated during contraction, which could be determined from the length-tension relationships and the corresponding shortening velocity. In general, the load displacement decreased as the load mass increased from 25 to 85% of the maximal isometric force. For loads less than 25% of the maximal isometric force, slight decrease in displacement was consistently observed. The displacement attenuation was dependent on the contraction frequency but uniform for all the load masses applied to the muscle. A pure time delay of 5 ms was present and accounted for various physiological processes such as conduction time in nerve and muscle, neuromuscular junction transmission, and excitation-contraction coupling. A quantitative equation was developed to describe the muscle's dynamic response under isotonic conditions and for a wide range of loads for use in various applications.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Ross, Sheldon M., and Zegang Zhu. "On the Structure of a Swing Contract's Optimal Value and Optimal Strategy." Journal of Applied Probability 45, no. 1 (March 2008): 1–15. http://dx.doi.org/10.1239/jap/1208358947.

Повний текст джерела

Анотація:

Consider a sales contract, called a swing contract, between a seller and a buyer concerning some underlying commodity, with the contract specifying that during some future time interval the buyer will purchase an amount of the commodity between some specified minimum and maximum values. The purchase price and capacity at each time point is also prespecified in the contract. Assuming a random market price process and ignoring the possibility of storage, we look for the maximal expected net gain for the buyer of such a contract, and the strategy that achieves this maximal expected net gain. We study the effects that various contract constraints and market price processes have on the optimal strategy and on the contract value. We show how we can reduce the general swing contract to a multiple exercising of American (Bermudan) style options. Also, in important special cases, we give explicit expressions for the optimal contract value function and the optimal strategy.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Ross, Sheldon M., and Zegang Zhu. "On the Structure of a Swing Contract's Optimal Value and Optimal Strategy." Journal of Applied Probability 45, no. 01 (March 2008): 1–15. http://dx.doi.org/10.1017/s0021900200003910.

Повний текст джерела

Анотація:

Consider a sales contract, called a swing contract, between a seller and a buyer concerning some underlying commodity, with the contract specifying that during some future time interval the buyer will purchase an amount of the commodity between some specified minimum and maximum values. The purchase price and capacity at each time point is also prespecified in the contract. Assuming a random market price process and ignoring the possibility of storage, we look for the maximal expected net gain for the buyer of such a contract, and the strategy that achieves this maximal expected net gain. We study the effects that various contract constraints and market price processes have on the optimal strategy and on the contract value. We show how we can reduce the general swing contract to a multiple exercising of American (Bermudan) style options. Also, in important special cases, we give explicit expressions for the optimal contract value function and the optimal strategy.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Cho, Sanghyun, and Young Hwan You. "On Sharp Hölder Estimates of the Cauchy-Riemann Equation on Pseudoconvex Domains inCnwith One Degenerate Eigenvalue." Abstract and Applied Analysis 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/731068.

Повний текст джерела

Анотація:

LetΩbe a smoothly bounded pseudoconvex domain inCnwith one degenerate eigenvalue and assume that there is a smooth holomorphic curveVwhose order of contact withbΩatz0∈bΩis larger than or equal toη. We show that the maximal gain in Hölder regularity for solutions of the∂¯-equation is at most1/η.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Treml, Benedikt, Hannes Gatterer, Johannes Burtscher, Axel Kleinsasser, and Martin Burtscher. "A Focused Review on the Maximal Exercise Responses in Hypo- and Normobaric Hypoxia: Divergent Oxygen Uptake and Ventilation Responses." International Journal of Environmental Research and Public Health 17, no. 14 (July 20, 2020): 5239. http://dx.doi.org/10.3390/ijerph17145239.

Повний текст джерела

Анотація:

The literature suggests that acute hypobaric (HH) and normobaric (NH) hypoxia exposure elicits different physiological responses. Only limited information is available on whether maximal cardiorespiratory exercise test outcomes, performed on either the treadmill or the cycle ergometer, are affected differently by NH and HH. A focused literature review was performed to identify relevant studies reporting cardiorespiratory responses in well-trained male athletes (individuals with a maximal oxygen uptake, VO2max > 50 mL/min/kg at sea level) to cycling or treadmill running in simulated acute HH or NH. Twenty-one studies were selected. The exercise tests in these studies were performed in HH (n = 90) or NH (n = 151) conditions, on a bicycle ergometer (n = 178) or on a treadmill (n = 63). Altitudes (simulated and terrestrial) varied between 2182 and 5400 m. Analyses (based on weighted group means) revealed that the decline in VO2max per 1000 m gain in altitude was more pronounced in acute NH vs. HH (−7.0 ± 1.4% vs. −5.6 ± 0.9%). Maximal minute ventilation (VEmax) increased in acute HH but decreased in NH with increasing simulated altitude (+1.9 ± 0.9% vs. −1.4 ± 1.8% per 1000 m gain in altitude). Treadmill running in HH caused larger decreases in arterial oxygen saturation and heart rate than ergometer cycling in acute HH, which was not the case in NH. These results indicate distinct differences between maximal cardiorespiratory responses to cycling and treadmill running in acute NH or HH. Such differences should be considered when interpreting exercise test results and/or monitoring athletic training.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Scislo, Tadeusz J., Robert A. Augustyniak, and Donal S. O’Leary. "Differential arterial baroreflex regulation of renal, lumbar, and adrenal sympathetic nerve activity in the rat." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 275, no. 4 (October 1, 1998): R995—R1002. http://dx.doi.org/10.1152/ajpregu.1998.275.4.r995.

Повний текст джерела

Анотація:

Lumbar (LSNA), renal (RSNA), or adrenal sympathetic nerve activity (ASNA) is most commonly used as an index of sympathetic nerve activity in investigations of arterial baroreflex control in the rat. Although differential regulation of sympathetic outputs to different organs has been extensively studied, no direct and simultaneous comparisons of the full range of baroreflex reactivity have been described for these sympathetic outputs. Therefore, we compared steady-state sigmoidal baroreflex stimulus-response curves (via phenylephrine-nitroprusside infusion) for RSNA recorded simultaneously with LSNA or ASNA in urethan-chloralose-anesthetized male Sprague-Dawley rats. Characteristics of the baroreflex curves differed significantly between all three sympathetic outputs. ASNA exhibited the greatest range of baroreflex regulation, the highest upper level of activity, and the widest distribution of the gain over a broad range of mean arterial pressure (MAP). RSNA exhibited greater gain than LSNA. LSNA showed the smallest range and maximal inhibition in comparison to other sympathetic outputs. However, all three nerves responded similarly to baroreflex stimulation and unloading in the range in MAP close to the operating point. We conclude that baroreflex regulation of sympathetic activity shows wide regional variability in gain, range, and maximal inhibition. Therefore, the entire stimulus-response relationship should be considered in comparing regional sympathetic responses.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Holm, J., M. Gamborg, S. Gammeltoft, L. Ward, B. Heitmann, and T. Soerensen. "Leptin increases during weight gain reach an upper maximal plateau: Longitudinal analysis in children." Acta Paediatrica 94 (June 1, 2005): 50b—50. http://dx.doi.org/10.1080/08035320510035500.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Holm, J. C., M. Gamborg, S. Gammeltoft, L. Ward, B. L. Heitmann, and T. IA Soerensen. "Leptin increases during weight gain reach an upper maximal plateau: Longitudinal analysis in children." Acta Paediatrica 94 (January 2, 2007): 50b—50. http://dx.doi.org/10.1111/j.1651-2227.2005.tb02135.x.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Daussin, Frédéric N., Joffrey Zoll, Stéphane P. Dufour, Elodie Ponsot, Evelyne Lonsdorfer-Wolf, Stéphane Doutreleau, Bertrand Mettauer, François Piquard, Bernard Geny, and Ruddy Richard. "Effect of interval versus continuous training on cardiorespiratory and mitochondrial functions: relationship to aerobic performance improvements in sedentary subjects." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 295, no. 1 (July 2008): R264—R272. http://dx.doi.org/10.1152/ajpregu.00875.2007.

Повний текст джерела

Анотація:

The goal of the study was to determine the effects of continuous (CT) vs. intermittent (IT) training yielding identical mechanical work and training duration on skeletal muscle and cardiorespiratory adaptations in sedentary subjects. Eleven subjects (6 men and 5 women, 45 ± 3 years) were randomly assigned to either of the two 8-wk training programs in a cross-over design, separated by 12 wk of detraining. Maximal oxygen uptake (V̇o2max) increased after both trainings (9% with CT vs. 15% with IT), whereas only IT was associated with faster V̇o2 kinetics (τ: 68.0 ± 1.6 vs. 54.9 ± 0.7 s, P < 0.05) measured during a test to exhaustion (TTE) and with improvements in maximal cardiac output (Qmax, from 18.1 ± 1.1 to 20.1 ± 1.2 l/min; P < 0.01). Skeletal muscle mitochondrial oxidative capacities ( Vmax) were only increased after IT (3.3 ± 0.4 before and 4.5 ± 0.6 μmol O2·min−1·g dw−1 after training; P < 0.05), whereas capillary density increased after both trainings, with a two-fold higher enhancement after CT (+21 ± 1% for IT and +40 ± 3% after CT, P < 0.05). The gain of Vmax was correlated with the gain of TTE and the gain of V̇o2max with IT. The gain of Qmax was also correlated with the gain of VO2max. These results suggest that fluctuations of workload and oxygen uptake during training sessions, rather than exercise duration or global energy expenditure, are key factors in improving muscle oxidative capacities. In an integrative view, IT seems optimal in maximizing both peripheral muscle and central cardiorespiratory adaptations, permitting significant functional improvement. These data support the symmorphosis concept in sedentary subjects.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Hunter, Steve, Julian Werth, Darren James, Yiannis Lambrianides, Kenton Smith, Kiros Karamanidis, and Gaspar Epro. "Reliability and Accuracy of a Time-Efficient Method for the Assessment of Achilles Tendon Mechanical Properties by Ultrasonography." Sensors 22, no. 7 (March 26, 2022): 2549. http://dx.doi.org/10.3390/s22072549.

Повний текст джерела

Анотація:

The assessment of the force–length relationship under mechanical loading is widely used to evaluate the mechanical properties of tendons and to gain information about their adaptation, function, and injury. This study aimed to provide a time-efficient ultrasound method for assessing Achilles tendon mechanical properties. On two days, eleven healthy young non-active adults performed eight maximal voluntary isometric ankle plantarflexion contractions on a dynamometer with simultaneous ultrasonographic recording. Maximal tendon elongation was assessed by digitizing ultrasound images at rest and at maximal tendon force. Achilles tendon stiffness index was calculated from the ratio of tendon force-to-strain. No within- and between-day differences were detected between the proposed method and manual frame by frame tracking in Achilles tendon maximal force, maximal elongation, maximal strain, and stiffness index. The overall coefficient of variation between trials ranged from 3.4% to 10.3% and average difference in tendon tracking between methods was less than 0.6% strain. Furthermore, an additional assessment demonstrated significant differences between elite athletes, healthy young, and older adults in Achilles tendon force and stiffness index. Hence, the analysis has the potential to reliably and accurately monitor changes in Achilles tendon mechanical properties due to aging and altered mechanical loading in a time-efficient manner.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Lavi, Ron, Or Sattath, and Aviv Zohar. "Redesigning Bitcoin’s Fee Market." ACM Transactions on Economics and Computation 10, no. 1 (March 31, 2022): 1–31. http://dx.doi.org/10.1145/3530799.

Повний текст джерела

Анотація:

The Bitcoin payment system involves two agent types: users that transact with the currency and pay fees and miners in charge of authorizing transactions and securing the system in return for these fees. Two of Bitcoin’s challenges are (i) securing sufficient miner revenues as block rewards decrease, and (ii) alleviating the throughput limitation due to a small maximal block size cap. These issues are strongly related as increasing the maximal block size may decrease revenue due to Bitcoin’s pay-your-bid approach. To decouple them, we analyze the “monopolistic auction” [ 16 ], showing (i) its revenue does not decrease as the maximal block size increases, (ii) it is resilient to an untrusted auctioneer (the miner), and (iii) simplicity for transaction issuers (bidders), as the average gain from strategic bid shading (relative to bidding one’s value) diminishes as the number of bids increases.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Areta, José L. "Case Study: Resumption of Eumenorrhea in Parallel With High Training Load After 4 Years of Menstrual Dysfunction: A 5-Year Follow-Up of an Elite Female Cyclist." International Journal of Sport Nutrition and Exercise Metabolism 30, no. 3 (May 1, 2020): 229–34. http://dx.doi.org/10.1123/ijsnem.2019-0284.

Повний текст джерела

Анотація:

The female athlete triad is a condition where low energy availability is typically observed together with menstrual dysfunction and/or low bone mineral density. How this condition affects maximal work capacity in endurance athletes is not clear, and the recovery time course of menses with increased energy availability with concomitant high training load is unknown. This case study of an amenorrheic elite road cyclist reports resumption of normal menstrual function after weight gain during a 5-year period (2014–2019), while engaged in high training load and competition. The athlete ( 3.54 L/min, 64 ml·min−1·kg−1, aerobic peak power output 300 W, 5.4 W/kg) reported amenorrhea (2013–2015) and oligomenorrhea (2015–2018). Training load increased from 2014 to 2019 (584–818 hr/year and 26,707–41,945 training stress score/year). Regular menses (every 23–35 days) resumed in June 2018, ∼5–6 months after a weight gain episode. During the period of menstrual dysfunction, body mass was 51.3 ± 2.25 kg (mean ± 95% confidence limit) and fat percentage was 19% (dual-energy X-ray absorptiometry, 2016), and after weight gain, body mass was 56.8 ± 2.63 kg and fat percentage was 25% (dual-energy X-ray absorptiometry, 2019). Crank-based power meter data showed absolute mean maximal power (in watts) improvement over the 5 s to 4 hr range through the 2014–2019 period, while relative mean maximal power (in watts per kilogram) likely peaked in the 2015–2016 season for 5 min, 20 min, and 30 min, but remained mostly unchanged across seasons. Results suggest that (a) the best relative power output associated with aerobic capacity (5 min to 1 hr) can be achieved during menstrual dysfunction, (b) high performance achieved despite an increase in body mass, and (c) resumption of menses is achievable while maintaining high training loads when coupled with high energy availability.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Aboderin, O. J., O. O. Ojebiyi, A. J. Popoola, A. Oyewole, and N. T. Olaitan. "Growth performance of broiler starter chickens fed varying levels of five different vitamin-mineral premixes." Nigerian Journal of Animal Production 48, no. 6 (January 18, 2022): 121–29. http://dx.doi.org/10.51791/njap.v48i6.3285.

Повний текст джерела

Анотація:

Vitamin Mineral Premixes (VMPs) are the usual medium through which poultry diets are fortified to ensure better utilization of nutrients. Poultry ingredients could be low in some vitamins, thus the addition of premix to poultry diet is therefore a good insurance to protect birds from stress, diseases and disorder. Each manufacturer claimed superior effectiveness and potency without any cognate experimental evidence. Therefore, this research surveyed the available broiler VMPs in Ogbomoso and compared their potency through a feeding trial. A survey was carried out using structured questionnaire administered to feed millers and poultry farmers after which a feeding trial was conducted using the popular VMPs. Arbor acre broiler strains (n=330) day old chicks weighing 36.9±5.00g were randomly allotted diets without any VMP (control) while others were supplemented with five different VMPs at 0.20 and 0.25% to obtain diets 0.20VMP1, 0.20VMP2, 0.20VMP3, 0.20VMP4, 0.20VMP5, 0.25VMP1, 0.25VMP2, 0.25VMP3, 0.25VMP4 and 0.25VMP5 respectively in a completely randomized design using a 5x2 factorial arrangement and reared for 56 days. Daily feed intake, weight gain and feed to gain ratio were assessed. Data were analyzed using descriptive statistics and ANOVA at P<0.05. The study revealed 16.70% of the premixes surveyed were imported while 83.30% were produced in Nigeria. Also, 10.00% of the respondents bought himix, 36.70% optimix, 13.30% wrightmix, 10.00% aeromix, 5.00% duramix, 6.7% micromix, 5% livestovit and 13.3% agrited. The on-farm study showed that the final liveweight and daily weight gain were significantly higher in birds fed the control (649.33g, 21.75g respectively) compared with birds fed 0.20VMP4 having the lowest values for the starter phase (557.93, 19.95g). Feed cost per kg weight gain was higher (? 270.86) in birds fed 0.20VMP5 while the lowest (? 224.90) was observed in control. The daily feed intake ranged between 44.53g in 0.20VMP4 and 47.50g in 0.20VMP5.In conclusion, the commonest vitamin mineral premix used by broiler farmers in Ogbomoso was Optimix and the broiler chickens fed the control diet had the best growth performance and were the most economical diet. Les prémélanges vitaminiques et minéraux (PVM) sont le moyen habituel par lequel les régimes alimentaires des volailles sont enrichis pour assurer une meilleure utilisation des nutriments. Les ingrédients de la volaille peuvent être pauvres en certaines vitamines, donc l'ajout de prémélange à l'alimentation de la volaille est donc une bonne assurance pour protéger les oiseaux du stress, des maladies et des troubles. Chaque fabricant a revendiqué une efficacité et une puissance supérieures sans aucune preuve expérimentale apparentée. Par conséquent, cette recherche a étudié les PVM de poulets de chair disponibles à Ogbomoso et a comparé leur puissance au moyen d'un essai d'alimentation. Une enquête a été réalisée à l'aide d'un questionnaire structuré administré aux meuniers et aux éleveurs de volaille, après quoi un essai d'alimentation a été mené à l'aide des PVM populaires. Des souches de poulets de chair Arbor acre (n = 330) d'un jour pesant 36,9 ± 5,00 g ont reçu des régimes aléatoires sans aucun PVM (témoin) tandis que d'autres ont été supplémentés avec cinq PVM différents à 0,20 et 0,25 % pour obtenir des régimes 0,20PVM1, 0,20PVM2, 0,20PVM3, 0,20PVM4, 0,20PVM5, 0,25PVM1, 0,25PVM2, 0,25PVM3, 0,25PVM4 et 0,25PVM5 respectivement dans un plan complètement randomisé utilisant un arrangement factoriel 5x2 et élevés pendant 56 jours. La prise alimentaire quotidienne, le gain de poids et le rapport alimentation/gain ont été évalués. Les données ont été analysées à l'aide de statistiques descriptives et ANOVA à P<0,05. L'étude a révélé que 16,70 % des prémélanges étudiés étaient importés tandis que 83,30 % étaient produits au Nigeria. De plus, 10,00 % des personnes interrogées ont acheté himix, 36,70 % optimix, 13,30 % wrightmix, 10,00 % aeromix, 5,00 % duramix, 6,7 % micromix, 5 % livestovit et 13,3 % agrited. L'étude à la ferme a montré que le poids vif final et le gain de poids quotidien étaient significativement plus élevés chez les oiseaux nourris avec le témoin (649,33 g, 21,75 g respectivement) par rapport aux oiseaux nourris avec 0,20 PVM4 ayant les valeurs les plus faibles pour la phase de démarrage (557,93, 19,95 g) . Le coût des aliments par kg de gain de poids était plus élevé (? 270,86) chez les oiseaux nourris avec 0,20PVM5 tandis que le plus bas (? 224,90) a été observé chez les témoins. La prise alimentaire quotidienne variait entre 44,53 g dans 0,20VMP4 et 47,50 g dans 0,20PVM5 régime le plus économique.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Melnyk, R. B., and J. M. Martin. "Insulin and central regulation of spontaneous fattening and weight loss." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 249, no. 2 (August 1, 1985): R203—R208. http://dx.doi.org/10.1152/ajpregu.1985.249.2.r203.

Повний текст джерела

Анотація:

Insulin binding to receptors in a partially purified hypothalamic membrane preparation is altered by prolonged starvation. To define further the relationship between hypothalamic insulin binding and energy balance, we studied the Richardson's ground squirrel, a hibernator that exhibits spontaneous 6- to 8-mo body weight cycles when kept in constant conditions. Isolated pancreatic islets from squirrels killed during the weight gain phase had greater glucose-stimulated insulin secretion than those from weight loss phase animals, and adipocytes showed significantly greater glucose incorporation into total lipid in response to insulin. Differences in lipogenesis were not attributable to changes in insulin-binding capacity. Hypothalamic tissue from weight gain phase animals bound more insulin than that from weight loss phase animals. Maximal binding was correlated with pancreatic islet responsiveness and maximal insulin-stimulated lipogenesis. The strong positive correlation between peripheral metabolic events associated with spontaneous alterations in energy balance and the binding kinetics of hypothalamic insulin receptors suggests that insulin may play an important role in the central regulation of body weight.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Gain en puissance maximal"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями