Pharmacokinetics of detomidine administered to horses at rest and after maximal exercise.

PubMed

Hubbell, J A E; Sams, R A; Schmall, L M; Robertson, J T; Hinchcliff, K W; Muir, W W

2009-05-01

Increased doses of detomidine are required to produce sedation in horses after maximal exercise compared to calm or resting horses. To determine if the pharmacokinetics of detomidine in Thoroughbred horses are different when the drug is given during recuperation from a brief period of maximal exercise compared to administration at rest. Six Thoroughbred horses were preconditioned by exercising them on a treadmill. Each horse ran a simulated race at a treadmill speed that caused it to exercise at 120% of its maximal oxygen consumption. One minute after the end of exercise, horses were treated with detomidine. Each horse was treated with the same dose of detomidine on a second occasion a minimum of 14 days later while standing in a stocks. Samples of heparinised blood were obtained at various time points on both occasions. Plasma detomidine concentrations were determined by liquid chromatography-mass spectrometry. The plasma concentration vs. time data were analysed by nonlinear regression analysis. Median back-extrapolated time zero plasma concentration was significantly lower and median plasma half-life and median mean residence time were significantly longer when detomidine was administered after exercise compared to administration at rest. Median volume of distribution was significantly higher after exercise but median plasma clearance was not different between the 2 administrations. Detomidine i.v. is more widely distributed when administered to horses immediately after exercise compared to administration at rest resulting in lower peak plasma concentrations and a slower rate of elimination. The dose requirement to produce an equivalent effect may be higher in horses after exercise than in resting horses and less frequent subsequent doses may be required to produce a sustained effect.

Reversible increase in maximal cortisol secretion rate in septic shock.

PubMed

Dorin, Richard I; Qualls, Clifford R; Torpy, David J; Schrader, Ronald M; Urban, Frank K

2015-03-01

Cortisol clearance is reduced in sepsis and may contribute to the development of impaired adrenocortical function that is thought to contribute to the pathophysiology of critical illness-related corticosteroid insufficiency. We sought to assess adrenocortical function using computer-assisted numerical modeling methodology to characterize and compare maximal cortisol secretion rate and free cortisol half-life in septic shock, sepsis, and healthy control subjects. Post hoc analysis of previously published total cortisol, free cortisol, corticosteroid-binding globulin, and albumin concentration data. Single academic medical center. Subjects included septic shock (n = 45), sepsis (n = 25), and healthy controls (n = 10). I.v. cosyntropin (250 μg). Solutions for maximal cortisol secretion rate and free cortisol half-life were obtained by least squares solution of simultaneous, nonlinear differential equations that account for free cortisol appearance and elimination as well as reversible binding to corticosteroid-binding globulin and albumin. Maximal cortisol secretion rate was significantly greater in septic shock (0.83 nM/s [0.44, 1.58 nM/s] reported as median [lower quartile, upper quartile]) compared with sepsis (0.51 nM/s [0.36, 0.62 nM/s]; p = 0.007) and controls (0.49 nM/s [0.42, 0.62 nM/s]; p = 0.04). The variance of maximal cortisol secretion rate in septic shock was also greater than that of sepsis or control groups (F test, p < 0.001). Free cortisol half-life was significantly increased in septic shock (4.6 min [2.2, 6.3 min]) and sepsis (3.0 min [2.3, 4.8 min] when compared with controls (2.0 min [1.2, 2.6 min]) (both p < 0.004). Results obtained by numerical modeling are consistent with comparable measures obtained by the gold standard stable isotope dilution method. Septic shock is associated with generally not only higher levels but also greater variance of maximal cortisol secretion rate when compared with control and sepsis groups. Additional studies

Pharmacokinetics and Concentration-Effect Relationship of Oral LSD in Humans.

PubMed

Dolder, Patrick C; Schmid, Yasmin; Haschke, Manuel; Rentsch, Katharina M; Liechti, Matthias E

2015-06-24

The pharmacokinetics of oral lysergic acid diethylamide are unknown despite its common recreational use and renewed interest in its use in psychiatric research and practice. We characterized the pharmacokinetic profile, pharmacokinetic-pharmacodynamic relationship, and urine recovery of lysergic acid diethylamide and its main metabolite after administration of a single oral dose of lysergic acid diethylamide (200 μg) in 8 male and 8 female healthy subjects. Plasma lysergic acid diethylamide concentrations were quantifiable (>0.1 ng/mL) in all the subjects up to 12 hours after administration. Maximal concentrations of lysergic acid diethylamide (mean±SD: 4.5±1.4 ng/mL) were reached (median, range) 1.5 (0.5-4) hours after administration. Concentrations then decreased following first-order kinetics with a half-life of 3.6±0.9 hours up to 12 hours and slower elimination thereafter with a terminal half-life of 8.9±5.9 hours. One percent of the orally administered lysergic acid diethylamide was eliminated in urine as lysergic acid diethylamide, and 13% was eliminated as 2-oxo-3-hydroxy-lysergic acid diethylamide within 24 hours. No sex differences were observed in the pharmacokinetic profiles of lysergic acid diethylamide. The acute subjective and sympathomimetic responses to lysergic acid diethylamide lasted up to 12 hours and were closely associated with the concentrations in plasma over time and exhibited no acute tolerance. These first data on the pharmacokinetics and concentration-effect relationship of oral lysergic acid diethylamide are relevant for further clinical studies and serve as a reference for the assessment of intoxication with lysergic acid diethylamide. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Pharmacokinetics and Concentration-Effect Relationship of Oral LSD in Humans

PubMed Central

Dolder, Patrick C.; Schmid, Yasmin; Haschke, Manuel; Rentsch, Katharina M.

2016-01-01

Background: The pharmacokinetics of oral lysergic acid diethylamide are unknown despite its common recreational use and renewed interest in its use in psychiatric research and practice. Methods: We characterized the pharmacokinetic profile, pharmacokinetic-pharmacodynamic relationship, and urine recovery of lysergic acid diethylamide and its main metabolite after administration of a single oral dose of lysergic acid diethylamide (200 μg) in 8 male and 8 female healthy subjects. Results: Plasma lysergic acid diethylamide concentrations were quantifiable (>0.1ng/mL) in all the subjects up to 12 hours after administration. Maximal concentrations of lysergic acid diethylamide (mean±SD: 4.5±1.4ng/mL) were reached (median, range) 1.5 (0.5–4) hours after administration. Concentrations then decreased following first-order kinetics with a half-life of 3.6±0.9 hours up to 12 hours and slower elimination thereafter with a terminal half-life of 8.9±5.9 hours. One percent of the orally administered lysergic acid diethylamide was eliminated in urine as lysergic acid diethylamide, and 13% was eliminated as 2-oxo-3-hydroxy-lysergic acid diethylamide within 24 hours. No sex differences were observed in the pharmacokinetic profiles of lysergic acid diethylamide. The acute subjective and sympathomimetic responses to lysergic acid diethylamide lasted up to 12 hours and were closely associated with the concentrations in plasma over time and exhibited no acute tolerance. Conclusions: These first data on the pharmacokinetics and concentration-effect relationship of oral lysergic acid diethylamide are relevant for further clinical studies and serve as a reference for the assessment of intoxication with lysergic acid diethylamide. PMID:26108222

Intermittent Drug Dosing Intervals Guided by the Operational Multiple Dosing Half Lives for Predictable Plasma Accumulation and Fluctuation

PubMed Central

Grover, Anita; Benet, Leslie Z.

2013-01-01

Intermittent drug dosing intervals are usually initially guided by the terminal pharmacokinetic half life and are dependent on drug formulation. For chronic multiple dosing and for extended release dosage forms, the terminal half life often does not predict the plasma drug accumulation or fluctuation observed. We define and advance applications for the operational multiple dosing half lives for drug accumulation and fluctuation after multiple oral dosing at steady-state. Using Monte Carlo simulation, our results predict a way to maximize the operational multiple dosing half lives relative to the terminal half life by using a first-order absorption rate constant close to the terminal elimination rate constant in the design of extended release dosage forms. In this way, drugs that may be eliminated early in the development pipeline due to a relatively short half life can be formulated to be dosed at intervals three times the terminal half life, maximizing compliance, while maintaining tight plasma concentration accumulation and fluctuation ranges. We also present situations in which the operational multiple dosing half lives will be especially relevant in the determination of dosing intervals, including for drugs that follow a direct PKPD model and have a narrow therapeutic index, as the rate of concentration decrease after chronic multiple dosing (that is not the terminal half life) can be determined via simulation. These principles are illustrated with case studies on valproic acid, diazepam, and anti-hypertensives. PMID:21499748

Alternative trailer configurations for maximizing payloads

Treesearch

Jason D. Thompson; Dana Mitchell; John Klepac

2017-01-01

In order for harvesting contractors to stay ahead of increasing costs, it is imperative that they employ all options to maximize productivity and efficiency. Transportation can account for half the cost to deliver wood to a mill. Contractors seek to maximize truck payload to increase productivity. The Forest Operations Research Unit, Southern Research Station, USDA...

Comparison of cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine spontaneously breathing 50% or maximal oxygen concentrations.

PubMed

Karrasch, Nicole M; Hubbell, John A E; Aarnes, Turi K; Bednarski, Richard M; Lerche, Phillip

2015-04-01

This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pressures, and tidal volume were measured. Arterial and mixed-venous blood samples were collected prior to sedation (baseline), during 30 minutes of anesthesia, 10 minutes after disconnection from O2, and 30 minutes after standing. Shunt fraction, O2 delivery, and alveolar-arterial O2 partial pressures difference [P(A-a)O2] were calculated. Recovery times were recorded. There were no significant differences between groups in cardiorespiratory parameters or in P(A-a)O2 at baseline or 30 minutes after standing. Oxygen partial pressure difference in the 50% group was significantly less than in the maximal O2 group during anesthesia.

Comparison of cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine spontaneously breathing 50% or maximal oxygen concentrations

PubMed Central

Karrasch, Nicole M.; Hubbell, John A.E.; Aarnes, Turi K.; Bednarski, Richard M.; Lerche, Phillip

2015-01-01

This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pressures, and tidal volume were measured. Arterial and mixed-venous blood samples were collected prior to sedation (baseline), during 30 minutes of anesthesia, 10 minutes after disconnection from O2, and 30 minutes after standing. Shunt fraction, O2 delivery, and alveolar-arterial O2 partial pressures difference [P(A-a)O2] were calculated. Recovery times were recorded. There were no significant differences between groups in cardiorespiratory parameters or in P(A-a)O2 at baseline or 30 minutes after standing. Oxygen partial pressure difference in the 50% group was significantly less than in the maximal O2 group during anesthesia. PMID:25829559

Relationship between sensitizer concentration and resist performance of chemically amplified extreme ultraviolet resists in sub-10 nm half-pitch resolution region

NASA Astrophysics Data System (ADS)

Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

2017-01-01

The development of lithography processes with sub-10 nm resolution is challenging. Stochastic phenomena such as line width roughness (LWR) are significant problems. In this study, the feasibility of sub-10 nm fabrication using chemically amplified extreme ultraviolet resists with photodecomposable quenchers was investigated from the viewpoint of the suppression of LWR. The relationship between sensitizer concentration (the sum of acid generator and photodecomposable quencher concentrations) and resist performance was clarified, using the simulation based on the sensitization and reaction mechanisms of chemically amplified resists. For the total sensitizer concentration of 0.5 nm-3 and the effective reaction radius for the deprotection of 0.1 nm, the reachable half-pitch while maintaining 10% critical dimension (CD) LWR was 11 nm. The reachable half-pitch was 7 nm for 20% CD LWR. The increase in the effective reaction radius is required to realize the sub-10 nm fabrication with 10% CD LWR.

Studying the hopping parameters of half-Heusler NaAuS using maximally localized Wannier function

NASA Astrophysics Data System (ADS)

Sihi, Antik; Lal, Sohan; Pandey, Sudhir K.

2018-04-01

Here, the electronic behavior of half-Heusler NaAuS is studied using PBEsol exchange correlation functional by plotting the band structure curve. These bands are reproduced using maximally localized Wannier function using WANNIER90. Tight-binding bands are nicely matched with density functional theory bands. By fitting the tight-binding model, hopping parameter for NaAuS is obtained by including Na 2s, 2p, Au 6s, 5p, 5d and S 3s, 3p orbitals within the energy interval of -5 to 16 eV around the Fermi level. In present study, hopping integrals for NaAuS are computed for the first primitive unit cell atoms as well as the first nearest neighbor primitive unit cell. The most dominating hopping integrals are found for Na (3s) - S (3s), Na (2px) - S (2px), Au (6s) - S (3px), Au (6s) - S (3py) and Au (6s) - S (3pz) orbitals. The hopping integrals for the first nearest neighbor primitive unit cell are also discussed in this manuscript. In future, these hopping integrals are very important to find the topological invariant for NaAuS compound.

Relationship among aqueous copper half-lives and responses of Pimephales promelas to a series of copper sulfate pentahydrate concentrations.

PubMed

Calomeni, Alyssa J; Kinley, Ciera M; Geer, Tyler D; Iwinski, Kyla J; Hendrikse, Maas; Rodgers, John H

2018-04-01

Copper algaecide exposures in situ are often of shorter duration than exposures for static toxicity experiments because aqueous concentrations in situ dissipate as a function of site-specific fate processes. Consequently, responses of organisms to static copper exposures may overestimate effects following in situ exposures. To understand the role of exposure duration for altering responses, Pimephales promelas survival was compared following static (96 h) and pulse (1.5, 4, 8, and 15 h half-lives) exposures of CuSO 4 •5H 2 O. Copper concentrations sorbed by fry indicated a consequence of different exposures. Responses of P. promelas to static exposures resulted in 96 h LC 50 s of 166 µgCu/L (95% confidence interval [CI], 142-189 µgCu/L) as soluble copper and 162 µgCu/L (CI, 140-183 µgCu/L) as acid soluble copper. Relative to static 96 h LC 50 s, exposures with half-lives of 1.5, 4 and 8 h resulted in LC 50 s 10, 3 and 2 times greater, respectively, for responses measured 96 h after exposure initiation. Copper concentrations extracted from fry exposed for 1.5, 4 and 8 h half-lives were less than the static experiment. However, copper sorbed by fry in the 15 h half-life experiment was not different than the static experiment. The relationship between 96 h LC 50 and 1/half-life was expressed using the equations y = 116 + 1360 × (R 2  = 0.97) for soluble copper and y = 147 + 1620 × (R 2  = 0.98) for acid soluble copper. Incorporation of exposure duration for predictions of P. promelas responses to copper pulse exposures increases prediction accuracy by an order of magnitude.

Effect of TPA on ion fluxes and DNA synthesis in vascular smooth muscle cells

PubMed Central

1985-01-01

Previous reports have suggested that phorbol esters can decrease the affinity of epidermal growth factor (EGF) for its cellular receptors. Investigations of the consequences of the interaction between phorbol esters and EGF, however, have been limited to EGF-stimulated Na/H exchange in A431 cells (Whitely, B., D. Cassel, Y.-X. Zuang, and L. Glaser, 1984, J. Cell Biol., 99:1162-1166). In the present study, the effect of the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) on EGF-stimulated ion transport and DNA synthesis was determined in cultured vascular smooth muscle cells (A7r5). It was found that TPA stimulated Na/H exchange when added alone (half-maximal stimulatory concentration, 25 nM). However, when cells were pretreated with TPA and then challenged with EGF, TPA significantly inhibited EGF-stimulated Na/H exchange (78%; half-maximal inhibition [Ki] at 2.5 nM). Subsequently the effects of TPA on Na/K/Cl co-transport were measured. TPA was observed to inhibit Na/K/Cl co-transport (half-maximal inhibitory concentration, 50 nM) and also to inhibit EGF-stimulated Na/K/Cl co-transport (100%; Ki at 5 nM). Finally, the effects of TPA on DNA synthesis were assessed. TPA had a modest stimulatory effect on DNA synthesis (half-maximal stimulatory concentration, 6 nM), but had a significant inhibitory effect on EGF-stimulated DNA synthesis (56%; Ki at 5 nM). These findings suggest that the inhibitory effect of TPA on EGF-receptor functions goes beyond previously reported effects on Na/H exchange in A431 cells and extends to EGF-stimulation of Na/K/Cl co- transport and DNA synthesis in vascular smooth muscle cells. PMID:2410432

Calculation of pressure half-time.

PubMed

Oyama, Mark A; Weidman, Jess A; Cole, Steven G

2008-06-01

Doppler echocardiography is useful in assessing the severity of obstructive cardiac lesions, such as mitral valve stenosis. The Doppler study can be used to calculate pressure half-time (PHT), which is defined as the time required for the pressure gradient across an obstruction to decrease to half of its maximal value. Thus, PHT increases as the severity of stenosis increases. In this report, we describe the methodology involved in measuring PHT in a dog with mitral valve stenosis before and after balloon valvuloplasty.

All half-lives are wrong, but some half-lives are useful.

PubMed

Wright, J G; Boddy, A V

2001-01-01

The half-life of a drug, which expresses a change in concentration in units of time, is perhaps the most easily understood pharmacokinetic parameter and provides a succinct description of many concentration-time profiles. The calculation of a half-life implies a linear, first-order, time-invariant process. No drug perfectly obeys such assumptions, although in practise this is often a valid approximation and provides invaluable quantitative information. Nevertheless, the physiological processes underlying half-life should not be forgotten. The concept of clearance facilitates the interpretation of factors affecting drug elimination, such as enzyme inhibition or renal impairment. Relating clearance to the observed concentration-time profile is not as naturally intuitive as is the case with half-life. As such, these 2 approaches to parameterising a linear pharmacokinetic model should be viewed as complementary rather than alternatives. The interpretation of pharmacokinetic parameters when there are multiple disposition phases is more challenging. Indeed, in any pharmacokinetic model, the half-lives are only one component of the parameters required to specify the concentration-time profile. Furthermore, pharmacokinetic parameters are of little use without a dose history. Other factors influencing the relevance of each disposition phase to clinical end-points must also be considered. In summarising the pharmacokinetics of a drug, statistical aspects of the estimation of a half-life are often overlooked. Half-lives are rarely reported with confidence intervals or measures of variability in the population, and some approaches to this problem are suggested. Half-life is an important summary statistic in pharmacokinetics, but care must be taken to employ it appropriately in the context of dose history and clinically relevant pharmacodynamic end-points.

The effect of lactate concentration on the handgrip strength during judo bouts.

PubMed

Bonitch-Góngora, Juan G; Bonitch-Domínguez, Juan G; Padial, Paulino; Feriche, Belen

2012-07-01

Judo is a combat sport in which the athletes attempt to hold and control their adversary through gripping techniques (kumi-kata) to apply opportune throwing techniques (nage-waza). Twelve male judo athletes, representing national teams, were recruited to investigate the changes in the maximal isometric strength in both hands before (pre) and after (post) 4 judo bouts and its relationship with the maximal blood lactic acid concentration. The subjects performed a maximal isometric contraction with each hand immediately before and after each bout. A blood sample was taken at 1, 3, and 14 minutes after each bout, and the lactic acid concentration was determined. An overall effect of the successive bouts on the maximal isometric handgrip strength of prebouts was observed for both hands (p < 0.05) but not in that of postbouts (p > 0.05). The dominant hand showed an overall decrease in the maximal isometric strength because of the bout, with the decrease being significant for the first, third, and fourth bouts (p < 0.05). The nondominant hand only showed a significant decrease in the first prebout and postbout (p < 0.05). We observed an inverse relationship between the maximal isometric handgrip strength of postbouts and maximum lactic acid concentration (Lacmax), and between the maximal isometric handgrip strength of postbouts and the lactic acid concentration at minute 14 of the recovery period (Lac14) (p < 0.05). These results show that successive judo bouts significantly reduce the maximal isometric strength of both hands and may suggest that fatigue of each hand depends on different factors. An enhanced understanding of the behavior of the isometric handgrip strength, and the factors that affect grip fatigue during judo bouts in the dominant and nondominant hands, can aid coaches in developing optimal training and exercise interventions that are aimed at mitigating decreases in the capacity of judo athletes to perform a grip.

Effect of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of classical antiepileptic drugs against maximal electroshock-induced seizures in mice.

PubMed

Zagaja, Miroslaw; Pyrka, Daniel; Skalicka-Wozniak, Krystyna; Glowniak, Kazimierz; Florek-Luszczki, Magdalena; Glensk, Michał; Luszczki, Jarogniew J

2015-09-01

The effects of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of four classical antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) were studied in the mouse maximal electroshock seizure model. Tonic hind limb extension (seizure activity) was evoked in adult male albino Swiss mice by a current (25 mA, 500 V, 50 Hz, 0.2 s stimulus duration) delivered via auricular electrodes. Total brain concentrations of antiepileptic drugs were measured by fluorescence polarization immunoassay to ascertain any pharmacokinetic contribution to the observed anticonvulsant effects. Results indicate that xanthotoxin (50 and 100 mg/kg, i.p.) significantly potentiated the anticonvulsant activity of carbamazepine against maximal electroshock-induced seizures (P<0.05 and P<0.001, respectively). Similarly, xanthotoxin (100 mg/kg, i.p.) markedly enhanced the anticonvulsant action of valproate in the maximal electroshock seizure test (P<0.001). In contrast, xanthotoxin (100 mg/kg, i.p.) did not affect the protective action of phenobarbital and phenytoin against maximal electroshock-induced seizures in mice. Moreover, xanthotoxin (100 mg/kg, i.p.) significantly increased total brain concentrations of carbamazepine (P<0.001) and valproate (P<0.05), but not those of phenytoin and phenobarbital, indicating pharmacokinetic nature of interactions between drugs. In conclusion, the combinations of xanthotoxin with carbamazepine and valproate, despite their beneficial effects in terms of seizure suppression in mice, were probably due to a pharmacokinetic increase in total brain concentrations of these antiepileptic drugs in experimental animals. Copyright © 2015. Published by Elsevier B.V.

Excretion Profiles and Half-Lives of Ten Urinary Polycyclic Aromatic Hydrocarbon Metabolites after Dietary Exposure

PubMed Central

Li, Zheng; Romanoff, Lovisa; Bartell, Scott; Pittman, Erin N.; Trinidad, Debra A.; McClean, Michael; Webster, Thomas F.; Sjödin, Andreas

2015-01-01

Human exposure to polycyclic aromatic hydrocarbons (PAHs) can be assessed by biomonitoring of their urinary mono-hydroxylated metabolites (OH-PAHs). Limited information exists on the human pharmacokinetics of OH-PAHs. This study aimed to investigate the excretion half-life of 1-hydroxypyrene (1-PYR), the most used biomarker for PAH exposure, and 9 other OH-PAHs following a dietary exposure in 9 non-smoking volunteers with no occupational exposure to PAHs. Each person avoided food with known high PAH-content during the study period, except for a high PAH-containing lunch (barbecued chicken) on the first day. Individual urine samples (n = 217) were collected from 15 hours before to 60 hours following the dietary exposure. Levels of all OH-PAHs in all subjects increased rapidly by 9–141 fold after the exposure, followed by a decrease consistent with first order kinetics, and returned to background levels 24–48 hours after the exposure. The average time to reach maximal concentration ranged from 3.1 h (1-naphthol) to 5.5 h (1-PYR). Creatinine-adjusted urine concentrations for each metabolite were analyzed using a non-linear mixed effects model including a term to estimate background exposure. The background-adjusted half-life estimate was 3.9 h for 1-PYR and ranged 2.5–6.1 h for the other 9 OH-PAHs, which in general, were shorter than those previously reported. The maximum concentrations after the barbecued chicken consumption were comparable to the levels found in reported occupational settings with known high PAH exposures. It is essential to consider the relatively short half-life, the timing of samples relative to exposures, and the effect of diet when conducting PAH exposure biomonitoring studies. PMID:22663094

Predictors of 25(OH)D half-life and plasma 25(OH)D concentration in The Gambia and the UK.

PubMed

Jones, K S; Assar, S; Vanderschueren, D; Bouillon, R; Prentice, A; Schoenmakers, I

2015-03-01

Predictors of 25(OH)D3 half-life were factors associated with vitamin D metabolism, but were different between people in The Gambia and the UK. Country was the strongest predictor of plasma 25(OH)D concentration, probably as a marker of UVB exposure. 25(OH)D3 half-life may be applied as a tool to investigate vitamin D expenditure. The aim of this study was to investigate predictors of 25(OH)D3 half-life and plasma 25(OH)D concentration. Plasma half-life of an oral tracer dose of deuterated-25(OH)D3 was measured in healthy men aged 24-39 years, resident in The Gambia, West Africa (n = 18) and in the UK during the winter (n = 18), countries that differ in calcium intake and vitamin D status. Plasma and urinary markers of vitamin D, calcium, phosphate and bone metabolism, nutrient intakes and anthropometry were measured. Normally distributed data are presented as mean (SD) and non-normal data as geometric mean (95% CI). Gambian compared to UK men had higher plasma concentrations of 25(OH)D (69 (13) vs. 29 (11) nmol/L; P < 0.0001); 1,25(OH)2D (181 (165, 197) vs. 120 (109, 132) pmol/L; P < 0.01); and parathyroid hormone (PTH) (50 (42, 60) vs. 33 (27, 39); P < 0.0001). There was no difference in 25(OH)D3 half-life (14.7 (3.5) days vs. 15.6 (2.5) days) between countries (P = 0.2). In multivariate analyses, 25(OH)D, 1,25(OH)2D, vitamin D binding protein and albumin-adjusted calcium (Caalb) explained 79% of variance in 25(OH)D3 half-life in Gambians, but no significant predictors were found in UK participants. For the countries combined, Caalb, PTH and plasma phosphate explained 39 % of half-life variability. 1,25(OH)2D, weight, PTH and country explained 81% of variability in 25(OH)D concentration; however, country alone explained 74%. Factors known to affect 25(OH)D metabolism predict 25(OH)D3 half-life, but these differed between countries. Country predicted 25(OH)D, probably as a proxy measure for UVB exposure and vitamin D supply. This study supports the use of 25(OH

Muscle Damage and Its Relationship with Muscle Fatigue During a Half-Iron Triathlon

PubMed Central

Coso, Juan Del; González-Millán, Cristina; Salinero, Juan José; Abián-Vicén, Javier; Soriano, Lidón; Garde, Sergio; Pérez-González, Benito

2012-01-01

Background To investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon. Methodology/Principal Findings We recruited 25 trained triathletes (36±7 yr; 75.1±9.8 kg) for the study. Before and just after the race, jump height and leg muscle power output were measured during a countermovement jump on a force platform to determine leg muscle fatigue. Body weight, handgrip maximal force and blood and urine samples were also obtained before and after the race. Blood myoglobin and creatine kinase concentrations were determined as markers of muscle damage. Results Jump height (from 30.3±5.0 to 23.4±6.4 cm; P<0.05) and leg power output (from 25.6±2.9 to 20.7±4.6 W · kg−1; P<0.05) were significantly reduced after the race. However, handgrip maximal force was unaffected by the race (430±59 to 430±62 N). Mean dehydration after the race was 2.3±1.2% with high inter-individual variability in the responses. Blood myoglobin and creatine kinase concentration increased to 516±248 µg · L−1 and 442±204 U · L−1, respectively (P<0.05) after the race. Pre- to post-race jump change did not correlate with dehydration (r = 0.16; P>0.05) but significantly correlated with myoglobin concentration (r = 0.65; P<0.001) and creatine kinase concentration (r = 0.54; P<0.001). Conclusions/significance During a half-iron distance triathlon, the capacity of leg muscles to produce force was notably diminished while arm muscle force output remained unaffected. Leg muscle fatigue was correlated with blood markers of muscle damage suggesting that muscle breakdown is one of the most relevant sources of muscle fatigue during a triathlon. PMID:22900101

Optimal effect-site concentration of remifentanil when combined with dexmedetomidine in patients undergoing cystoscopy

PubMed Central

Heo, Bongha; Kim, Minsun; Lee, Hyunjung; Park, Sanghee

2014-01-01

Background Cystoscopic procedure is a very common practice in the field of urology due to its ability to survey the bladder for a variety of indications. However, patients who undergo cystoscopy feel intense pain and discomfort. This study investigated the half maximal effective concentration (EC50) of remifentanil in preventing cystoscope insertion pain under sedation using dexmedetomidine. Methods The study was prospectively conducted on 18 male patients, aged 18 to 65. Remifentail infusion was initiated together with dexmedetomidine, and started at a dose of 2.4 ng/ml on the first patient. The effect-site concentration (Ce) of remifentanil for each subsequent patient was determined by the previous patient's response using Dixon's up-and-down method with an interval of 0.3 ng/ml. Patients received a loading dose of 1.0 µg/kg dexmedetomidine over 10 minutes, followed by a maintenance dose of 0.6 µg/kg/hr. After the patient's OAA/S score (Observer's Assessment of Alertness/Sedation scale) reached 3-4, and the Ce of remifentanil reached target concentration, the urologist was allowed to insert the cystoscope and the pain responses were observed. Results The effect-site concentration of remifentanil required to prevent cystoscope insertion pain in 50% of patients under sedation using dexmedetomidine was 1.30 ± 0.12 ng/ml by Dixon's up-and-down method. The logistic regression curve of the probability of response showed that the EC50 and EC95 values (95% confidence limits) of remifentanil were 1.33 ng/ml (1.12-1.52 ng/ml) and 1.58 ng/ml (1.44-2.48 ng/ml), respectively. Conclusions Cystoscopic procedure can be carried out successfully without any pain or adverse effects by optimal remifentanil effect-site concentration (EC50, 1.33 ng/ml; EC95, 1.58 ng/ ml) combined with sedation using dexmedetomidine. PMID:24567812

Phenomenology of maximal and near-maximal lepton mixing

NASA Astrophysics Data System (ADS)

Gonzalez-Garcia, M. C.; Peña-Garay, Carlos; Nir, Yosef; Smirnov, Alexei Yu.

2001-01-01

The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other (x=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter ɛ≡1-2 sin2 θex and quantify the present experimental status for \\|ɛ\\|<0.3. We show that both probabilities and observables depend on ɛ quadratically when effects are due to vacuum oscillations and they depend on ɛ linearly if matter effects dominate. The most important information on νe mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10-8 eV2<~Δm2<~2×10-7 eV2. In the mass ranges Δm2>~1.5×10-5 eV2 and 4×10-10 eV2<~Δm2<~2×10-7 eV2 the full interval \\|ɛ\\|<0.3 is allowed within ~4σ (99.995% CL) We suggest ways to measure ɛ in future experiments. The observable that is most sensitive to ɛ is the rate [NC]/[CC] in combination with the day-night asymmetry in the SNO detector. With theoretical and statistical uncertainties, the expected accuracy after 5 years is Δɛ~0.07. We also discuss the effects of maximal and near-maximal νe mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay.

Carbohydrate Ingestion Before and During Soccer Match Play and Blood Glucose and Lactate Concentrations

PubMed Central

Russell, Mark; Benton, David; Kingsley, Michael

2014-01-01

Context: The ingestion of carbohydrate (CHO) before and during exercise and at halftime is commonly recommended to soccer players for maintaining blood glucose concentrations throughout match play. However, an exercise-induced rebound glycemic response has been observed in the early stages of the second half of simulated soccer-specific exercise when CHO-electrolyte beverages were consumed regularly. Therefore, the metabolic effects of CHO beverage consumption throughout soccer match play remain unclear. Objective: To investigate the blood glucose and blood lactate responses to CHOs ingested before and during soccer match play. Design: Crossover study. Setting: Applied research study. Patients or Other Participants: Ten male outfield academy soccer players (age = 15.6 ± 0.2 years, height = 1.74 ± 0.02 m, mass = 65.3 ± 1.9 kg, estimated maximal oxygen consumption = 58.4 ± 0.8 mL·kg−1·min−1). Intervention(s): Players received a 6% CHO-electrolyte solution or an electrolyte (placebo) solution 2 hours before kickoff, before each half (within 10 minutes), and every 15 minutes throughout exercise. Blood samples were obtained at rest, every 15 minutes during the match (first half: 0–15, 15–30, and 30–45 minutes; second half: 45–60, 60–75, and 75–90 minutes) and 10 minutes into the halftime break. Main Outcome Measure(s): Metabolic responses (blood glucose and blood lactate concentrations) and markers of exercise intensity (heart rate) were recorded. Results: Supplementation influenced the blood glucose response to exercise (time × treatment interaction effect: P ≤ .05), such that glucose concentrations were higher at 30 to 45 minutes in the CHO than in the placebo condition. However, in the second half, blood glucose concentrations were similar between conditions because of transient reductions from peak values occurring in both trials at halftime. Blood lactate concentrations were elevated above those at rest in the first 15 minutes of exercise

Carbohydrate ingestion before and during soccer match play and blood glucose and lactate concentrations.

PubMed

Russell, Mark; Benton, David; Kingsley, Michael

2014-01-01

The ingestion of carbohydrate (CHO) before and during exercise and at halftime is commonly recommended to soccer players for maintaining blood glucose concentrations throughout match play. However, an exercise-induced rebound glycemic response has been observed in the early stages of the second half of simulated soccer-specific exercise when CHO-electrolyte beverages were consumed regularly. Therefore, the metabolic effects of CHO beverage consumption throughout soccer match play remain unclear. To investigate the blood glucose and blood lactate responses to CHOs ingested before and during soccer match play. Crossover study. Applied research study. Ten male outfield academy soccer players (age = 15.6 ± 0.2 years, height = 1.74 ± 0.02 m, mass = 65.3 ± 1.9 kg, estimated maximal oxygen consumption = 58.4 ± 0.8 mL·kg(-1)·min(-1)). Players received a 6% CHO-electrolyte solution or an electrolyte (placebo) solution 2 hours before kickoff, before each half (within 10 minutes), and every 15 minutes throughout exercise. Blood samples were obtained at rest, every 15 minutes during the match (first half: 0-15, 15-30, and 30-45 minutes; second half: 45-60, 60-75, and 75-90 minutes) and 10 minutes into the halftime break. Metabolic responses (blood glucose and blood lactate concentrations) and markers of exercise intensity (heart rate) were recorded. Supplementation influenced the blood glucose response to exercise (time × treatment interaction effect: P ≤ .05), such that glucose concentrations were higher at 30 to 45 minutes in the CHO than in the placebo condition. However, in the second half, blood glucose concentrations were similar between conditions because of transient reductions from peak values occurring in both trials at halftime. Blood lactate concentrations were elevated above those at rest in the first 15 minutes of exercise (time-of-sample effect: P < .001) and remained elevated throughout exercise. Supplementation did not influence the pattern of

Skeletal muscle fiber type composition and performance during repeated bouts of maximal, concentric contractions

NASA Technical Reports Server (NTRS)

Colliander, E. B.; Dudley, G. A.; Tesch, P. A.

1988-01-01

Force output and fatigue and recovery patterns were studied during intermittent short-term exercise. 27 men performed three bouts of 30 maximal unilateral knee extensions on 2 different occasions. Blood flow was maintained or occluded during recovery periods (60 s). Blood flow was restricted by inflating a pneumatic cuff placed around the proximal thigh. Muscle biopsies from vastus lateralis were analyzed for identification of fast twitch (FT) and slow twitch (ST) fibers and relative FT area. Peak torque decreased during each bout of exercise and more when blood flow was restricted during recovery. Initial peak torque (IPT) and average peak torque (APT) decreased over the three exercise bouts. This response was 3 fold greater without than with blood flow during recovery. IPT and APT decreased more in individuals with mainly FT fibers than in those with mainly ST fibers. It is suggested that performance during repeated bouts of maximal concentric contractions differs between individuals with different fiber type composition. Specifically, in high intensity, intermittent exercise with emphasis on anaerobic energy release a high FT composition may not necessarily be advantageous for performance.

Pharmacokinetic-based prediction of real-life dosing of extended half-life clotting factor concentrates on hemophilia

PubMed Central

Gherardini, Stefano

2018-01-01

The improvement of clotting factor concentrates (CFCs) has undergone an impressive boost during the last six years. Since 2010, several new recombinant factor (rF)VIII/IX concentrates entered phase I/II/III clinical trials. The improvements are related to the culture of human embryonic kidney (HEK) cells, post-translational glycosylation, PEGylation, and co-expression of the fragment crystallizable (Fc) region of immunoglobulin (Ig)G1 or albumin genes in the manufacturing procedures. The extended half-life (EHL) CFCs allow an increase of the interval between bolus administrations during prophylaxis, a very important advantage for patients with difficulties in venous access. Although the inhibitor risk has not been fully established, phase III studies have provided standard prophylaxis protocols, which, compared with on-demand treatment, have achieved very low annualized bleeding rates (ABRs). The key pharmacokinetics (PK) parameter to tailor patient therapy is clearance, which is more reliable than the half-life of CFCs; the clearance considers the decay rate of the drug concentration–time profile, while the half-life considers only the half concentration of the drug at a given time. To tailor the prophylaxis of hemophilia patients in real-life, we propose two formulae (expressed in terms of the clearance, trough and dose interval between prophylaxis), respectively based on the one- and two-compartmental models (CMs), for the prediction of the optimal single dose of EHL CFCs. Once the data from the time decay of the CFCs are fitted by the one- or two-CMs after an individual PK analysis, such formulae provide to the treater the optimal trade-off among trough and time-intervals between boluses. In this way, a sufficiently long time-interval between bolus administration could be guaranteed for a wider class of patients, with a preassigned level of the trough. Finally, a PK approach using repeated dosing is discussed, and some examples with new EHL CFCs are shown

Emotional Control and Instructional Effectiveness: Maximizing a Timeout

ERIC Educational Resources Information Center

Andrews, Staci R.

2015-01-01

This article provides recommendations for best practices for basketball coaches to maximize the instructional effectiveness of a timeout during competition. Practical applications are derived from research findings linking emotional intelligence to effective coaching behaviors. Additionally, recommendations are based on the implications of the…

Women show similar central and peripheral fatigue to men after half-marathon.

PubMed

Boccia, Gennaro; Dardanello, Davide; Tarperi, Cantor; Festa, Luca; La Torre, Antonio; Pellegrini, Barbara; Schena, Federico; Rainoldi, Alberto

2018-06-01

Women are known to be less fatigable than men in single-joint exercises, but fatigue induced by running has not been well understood. Here we investigated sex differences in central and peripheral fatigue and in rate of force development (RFD) in the knee extensors after a half-marathon run. Ten male and eight female amateur runners (aged 25-50 years) were evaluated before and immediately after a half-marathon race. Knee extensors forces were obtained under voluntary and electrically evoked isometric contractions. Maximal voluntary isometric contraction (MVC) force and peak RFD were recorded. Electrically doublet stimuli were delivered during the MVC and at rest to calculate the level of voluntary activation and the resting doublet twitch. After the race, decreases in MVC force (males: -11%, effect size [ES] 0.52; females: -11% ES 0.33), voluntary activation (males: -6%, ES 0.87; females: -4%, ES 0.72), and resting doublet twitch (males: -6%, ES 0.34; females: -8%, ES 0.30) were found to be similar between males and females. The decrease in peak RFD was found to be similar between males and females (males: -14%, ES 0.43; females: -15%, ES 0.14). Half-marathon run induced both central and peripheral fatigue, without any difference between men and women. The maximal and explosive strength loss was found similar between sexes. Together, these findings do not support the need of sex-specific training interventions to increase the tolerance to neuromuscular fatigue in half-marathoners.

Maximizing the Effective Use of Formative Assessments

ERIC Educational Resources Information Center

Riddell, Nancy B.

2016-01-01

In the current age of accountability, teachers must be able to produce tangible evidence of students' concept mastery. This article focuses on implementation of formative assessments before, during, and after instruction in order to maximize teachers' ability to effectively monitor student achievement. Suggested strategies are included to help…

Effect of Age and Other Factors on Maximal Heart Rate.

ERIC Educational Resources Information Center

Londeree, Ben R.; Moeschberger, Melvin L.

1982-01-01

To reduce confusion regarding reported effects of age on maximal exercise heart rate, a comprehensive review of the relevant English literature was conducted. Data on maximal heart rate after exercising with a bicycle, a treadmill, and after swimming were analyzed with regard to physical fitness and to age, sex, and racial differences. (Authors/PP)

The rate of lactate removal after maximal exercise: the effect of intensity during active recovery.

PubMed

Riganas, C S; Papadopoulou, Z; Psichas, N; Skoufas, D; Gissis, I; Sampanis, M; Paschalis, V; Vrabas, I S

2015-10-01

The aim of the present investigation was to determine the greater rate of lactate removal after a maximal rowing test using different intensities during active recovery. Thirty elite male rowers performed a simulated incremental exercise protocol on rowing ergometer to determine their maximal oxygen uptake and they divided into three equal sized group according to the type of the recovery that followed the assessment. The first group (N.=10) subjected to 20 min of passive recovery, while the second (N.=10) and the third (N.=10) groups performed 20 min of active recovery using the 25% and the 50% of each individual’s maximal power output, respectively. During the recovery period, every two min were performed measurements for the assessment of blood lactate, oxygen consumption and heart rate (HR). It was found that after 10 min of active recovery at 50% and 25% of maximal power output lactate concentration reduced by 43% and 15%, respectively, while during passive recovery lactate concentration found to be slightly elevated by 1%. It was also found that during recovery period, HR, oxygen consumption and pulmonary ventilation was significant elevated at higher exercise intensity compared to lower exercise intensity and passive recovery. It is concluded that in elite male rowers the active recovery provided higher rate of lactate removal compared to passive recovery. Moreover, active recovery at 50% of maximal power output had better results in lactate clearance compared to the active recovery of lower intensity (25% of maximal power output).

Effect of Interaction on the Majorana Zero Modes in the Kitaev Chain at Half Filling

NASA Astrophysics Data System (ADS)

Li, Zhidan; Han, Qiang

2018-04-01

The one dimension interacting Kitaev chain at half filling is studied. The symmetry of the Hamiltonian is examined by dual transformations and various physical quantities as functions of the fermion-fermion interaction $U$ are calculated systematically using the density matrix renormalization group method. A special value of interaction $U_p$ is revealed in the topological region of the phase diagram. We show that at $U_p$ the ground states are strictly two-fold degenerate even though the chain length is finite and the zero-energy peak due to the Majorana zero modes is maximally enhanced and exactly localized at the end sites. $U_p$ may be attractive or repulsive depending on other system parameters. We also give a qualitative understanding of the effect of interaction under the self-consistent mean field framework.

Rayleigh wave effects in an elastic half-space.

NASA Technical Reports Server (NTRS)

Aggarwal, H. R.

1972-01-01

Consideration of Rayleigh wave effects in a homogeneous isotropic linearly elastic half-space subject to an impulsive uniform disk pressure loading. An approximate formula is obtained for the Rayleigh wave effects. It is shown that the Rayleigh waves near the center of loading arise from the portion of the dilatational and shear waves moving toward the axis, after they originate at the edge of the load disk. A study is made of the vertical displacement due to Rayleigh waves at points on the axis near the surface of the elastic half-space.

Prophylactic Ankle Braces and the Kinematics and Kinetics of Half-Squat Parachute Landing.

PubMed

Wu, Di; Zheng, Chao; Wu, Ji; Hu, Tan; Huang, Rongrong; Wang, Lizhen; Fan, Yubo

2018-02-01

The objective of the study was to investigate the effects of dropping heights and prophylactic ankle braces on ankle joint biomechanics during half-squat parachute landing from two different heights. There were 30 male elite paratroopers with formal parachute landing training and more than 2 yr of parachute jumping experience who were recruited for this study. The subjects tested three different ankle brace conditions (no-brace, elastic brace, semirigid brace). Each subject was instructed to jump off a platform from two different heights of 0.4 m and 0.8 m, and land on a force plate in a half-squat posture. The Vicon 3D motion capture system and force plate were used to record and calculate kinematic and kinetic data. Dropping height had a significant effect on peak vertical ground reaction force (vGRF), maximum ankle angular displacement, and time to vGRF. As compared with the no-brace group, use of an elastic ankle brace significantly reduced peak vGRF by 18.57% and both braces significantly reduced the maximal angular displacements of dorsiflexion. The semirigid brace provided greater restriction against maximal angular displacement of inversion. The elastic and semirigid ankle braces both effectively restricted motion stability of the ankle joint in the sagittal plane, and the semirigid ankle brace prevented excessive inversion, although the comfort of this device should be improved overall.Wu D, Zheng C, Wu J, Hu T, Huang R, Wang L, Fan Y. Prophylactic ankle braces and the kinematics and kinetics of half-squat parachute landing. Aerosp Med Hum Perform. 2018; 89(2):141-146.

Changes in Serum Free Amino Acids and Muscle Fatigue Experienced during a Half-Ironman Triathlon

PubMed Central

Areces, Francisco; González-Millán, Cristina; Salinero, Juan José; Abian-Vicen, Javier; Lara, Beatriz; Gallo-Salazar, Cesar; Ruiz-Vicente, Diana; Del Coso, Juan

2015-01-01

The aim of this study was to investigate the relationship between changes in serum free amino acids, muscle fatigue and exercise-induced muscle damage during a half-ironman triathlon. Twenty-six experienced triathletes (age = 37.0 ± 6.8 yr; experience = 7.4 ± 3.0 yr) competed in a real half-ironman triathlon in which sector times and total race time were measured by means of chip timing. Before and after the race, a countermovement jump and a maximal isometric force test were performed, and blood samples were withdrawn to measure serum free amino acids concentrations, and serum creatine kinase levels as a blood marker of muscle damage. Total race time was 320 ± 37 min and jump height (-16.3 ± 15.2%, P < 0.001) and isometric force (-14.9 ± 9.8%; P = 0.007) were significantly reduced after the race in all participants. After the race, the serum concentration of creatine kinase increased by 368 ± 187% (P < 0.001). In contrast, the serum concentrations of essential (-27.1 ± 13.0%; P < 0.001) and non-essential amino acids (-24.4 ± 13.1%; P < 0.001) were significantly reduced after the race. The tryptophan/BCAA ratio increased by 42.7 ± 12.7% after the race. Pre-to-post changes in serum free amino acids did not correlate with muscle performance variables or post-race creatine kinase concentration. In summary, during a half-ironman triathlon, serum amino acids concentrations were reduced by > 20%. However, neither the changes in serum free amino acids nor the tryptophan/BCAA ratio were related muscle fatigue or muscle damage during the race. PMID:26372162

30-Second bound and pore water concentration mapping of cortical bone using 2D UTE with optimized half-pulses.

PubMed

Manhard, Mary Kate; Harkins, Kevin D; Gochberg, Daniel F; Nyman, Jeffry S; Does, Mark D

2017-03-01

MRI of cortical bone has the potential to offer new information about fracture risk. Current methods are typically performed with 3D acquisitions, which suffer from long scan times and are generally limited to extremities. This work proposes using 2D UTE with half pulses for quantitatively mapping bound and pore water in cortical bone. Half-pulse 2D UTE methods were implemented on a 3T Philips Achieva scanner using an optimized slice-select gradient waveform, with preparation pulses to selectively image bound or pore water. The 2D methods were quantitatively compared with previously implemented 3D methods in the tibia in five volunteers. The mean difference between bound and pore water concentration acquired from 3D and 2D sequences was 0.6 and 0.9 mol 1 H/L bone (3 and 12%, respectively). While 2D pore water methods tended to slightly overestimate concentrations relative to 3D methods, differences were less than scan-rescan uncertainty and expected differences between healthy and fracture-prone bones. Quantitative bound and pore water concentration mapping in cortical bone can be accelerated by 2 orders of magnitude using 2D protocols with optimized half-pulse excitation. Magn Reson Med 77:945-950, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Transient reaction of an elastic half-plane on a source of a concentrated boundary disturbance

NASA Astrophysics Data System (ADS)

Okonechnikov, A. S.; Tarlakovski, D. V.; Ul'yashina, A. N.; Fedotenkov, G. V.

2016-11-01

One of the key problems in studying the non-stationary processes of solid mechanics is obtaining of influence functions. These functions serve as solutions for the problems of effect of sudden concentrated loads on a body with linear elastic properties. Knowledge of the influence functions allows us to obtain the solutions for the problems with non-mixed boundary and initial conditions in the form of quadrature formulae with the help of superposition principle, as well as get the integral governing equations for the problems with mixed boundary and initial conditions. This paper offers explicit derivations for all nonstationary surface influence functions of an elastic half-plane in a plane strain condition. It is achieved with the help of combined inverse transform of a Fourier-Laplace integral transformation. The external disturbance is both dynamic and kinematic. The derived functions in xτ-domain are studied to find and describe singularities and are supplemented with graphs.

Thirty years after Chernobyl: Long-term determination of 137Cs effective half-life in the lichen Stereocaulon vesuvianum.

PubMed

Savino, F; Pugliese, M; Quarto, M; Adamo, P; Loffredo, F; De Cicco, F; Roca, V

2017-06-01

It has been widely shown that nuclear fallout includes substances, which accumulate in organisms such as crustaceans, fish, mushrooms and lichens, helping to evaluate the activity concentration of contaminants accumulated on a long time. In this context, radiocaesium deposited in soil following the Chernobyl accident on 26 April 1986 is known to have remained persistently available for plant uptake in many areas of Europe. Studies on the lichen Stereocaulon vesuvianum show the plant's high capacity to retain radionuclides from the substrate and the air. After the Chernobyl accident, starting from September 1986, at the Radioactivity Laboratory (LaRa) of the University of Naples Federico II, four monitoring campaigns to evaluate the activity concentration of four isotopes of the two elements caesium and ruthenium ( 134 Cs, 137 Cs, 103 Ru and 106 Ru) were carried out until 1999. This study allowed the effective half-life of 134 Cs and 137 Cs to be estimated. Twenty-eight years after the accident, in December 2014, a further sampling was carried out; only 137 Cs was revealed beyond the detection limits, measuring activity concentrations ranging from 20 to 40 Bq/kg, while the other radionuclides were no longer observed due to their shorter half-life. The last sampling allowed more precise determination of the effective half-life of 137 Cs (6.2 ± 0.1 year), due to the larger dataset on a large time period. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control

DOE PAGES

Datskos, Panos; Polizos, Georgios; Cullen, David A.; ...

2016-11-11

Role of water and ammonium hydroxide is investigated in evolution of shape of silica structures in the polyvinylpyrrolidone-pentanol emulsion droplet system. Shape control of silica structures is demonstrated by localization of the reagents. A uniform dispersion of reagents provided straight silica rods, while localization of the reagents at the emulsion droplet periphery provided a new type of structures half sphere-half funnel. The absence of water in the initial stages prompted a different nucleation process for the structure growth compared to when water was present in the intial stages. Effect of effective water concentration appeared to be related to the easemore » of diffusion of silica percursor inside the emulsion droplet,i.e., the higher the water concentration, the lower the silica precursor diffusion. Additionally, mixing the reagents in different combinations before adding to the reaction mixture also affected the silica structure thickness, length, and shape.« less

Synthesis of half-sphere/half-funnel-shaped silica structures by reagent localization and the role of water in shape control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datskos, Panos; Polizos, Georgios; Cullen, David A.

Role of water and ammonium hydroxide is investigated in evolution of shape of silica structures in the polyvinylpyrrolidone-pentanol emulsion droplet system. Shape control of silica structures is demonstrated by localization of the reagents. A uniform dispersion of reagents provided straight silica rods, while localization of the reagents at the emulsion droplet periphery provided a new type of structures half sphere-half funnel. The absence of water in the initial stages prompted a different nucleation process for the structure growth compared to when water was present in the intial stages. Effect of effective water concentration appeared to be related to the easemore » of diffusion of silica percursor inside the emulsion droplet,i.e., the higher the water concentration, the lower the silica precursor diffusion. Additionally, mixing the reagents in different combinations before adding to the reaction mixture also affected the silica structure thickness, length, and shape.« less

Effect of load, cadence, and fatigue on tibio-femoral joint force during a half squat.

PubMed

Hattin, H C; Pierrynowski, M R; Ball, K A

1989-10-01

Ten male university student volunteers were selected to investigate the 3D articular force at the tibio-femoral joint during a half squat exercise, as affected by cadence, different barbell loads, and fatigue. Each subject was required to perform a half squat exercise with a barbell weight centered across the shoulders at two different cadences (1 and 2 s intervals) and three different loads (15, 22 and 30% of the one repetition maximum). Fifty repetitions at each experimental condition were recorded with an active optoelectronic kinematic data capture system (WATSMART) and a force plate (Kistler). Processing the data involved a photogrammetric technique to obtain subject tailored anthropometric data. The findings of this study were: 1) the maximal antero-posterior shear and compressive force consistently occurred at the lowest position of the weight, and the forces were very symmetrically disposed on either side of this halfway point; 2) the medio-lateral shear forces were small over the squat cycle with few peaks and troughs; 3) cadence increased the antero-posterior shear (50%) and the compressive forces (28%); 4) as a subject fatigues, load had a significant effect on the antero-posterior shear force; 5) fatigue increased all articular force components but it did not manifest itself until about halfway through the 50 repetitions of the exercise; 6) the antero-posterior shear force was most affected by fatigue; 7) cadence had a significant effect on fatigue for the medio-lateral shear and compressive forces.

Optimal quantum error correcting codes from absolutely maximally entangled states

NASA Astrophysics Data System (ADS)

Raissi, Zahra; Gogolin, Christian; Riera, Arnau; Acín, Antonio

2018-02-01

Absolutely maximally entangled (AME) states are pure multi-partite generalizations of the bipartite maximally entangled states with the property that all reduced states of at most half the system size are in the maximally mixed state. AME states are of interest for multipartite teleportation and quantum secret sharing and have recently found new applications in the context of high-energy physics in toy models realizing the AdS/CFT-correspondence. We work out in detail the connection between AME states of minimal support and classical maximum distance separable (MDS) error correcting codes and, in particular, provide explicit closed form expressions for AME states of n parties with local dimension \

Effects of dexamethasone treatment on insulin-stimulated rates of glycolysis and glycogen synthesis in isolated incubated skeletal muscles of the rat.

PubMed Central

Leighton, B; Challiss, R A; Lozeman, F J; Newsholme, E A

1987-01-01

1. Rats were treated with dexamethasone for 4 days before measurement of the rates of lactate formation [which is an index of hexose transport; see Challiss, Lozeman, Leighton & Newsholme (1986) Biochem. J. 233, 377-381] and glycogen synthesis in response to various concentrations of insulin in isolated incubated soleus and extensor digitorum longus muscle preparations. 2. The concentration of insulin required to stimulate these processes half-maximally in soleus and extensor digitorum longus muscles isolated from control rats was about 100 muunits/ml. 3. Dexamethasone increases the concentration of insulin required to stimulate glycolysis half-maximally in soleus and extensor digitorum longus preparations to 250 and 300 muunits/ml respectively. The respective insulin concentrations necessary to stimulate glycogen synthesis half-maximally were about 430 and 370 muunits/ml for soleus and extensor digitorum longus muscle preparations isolated from steroid-treated rats. 5. Dexamethasone treatment did not change the amount of insulin bound to soleus muscle. PMID:3318810

The Physiological and Performance Effects of Caffeine Gum Consumed During A Simulated Half-Time By Professional Academy Rugby Union Players.

PubMed

M, Russell; N A, Reynolds; B T, Crewther; C J, Cook; L, Kilduff

2017-11-27

Despite the prevalence of caffeine as an ergogenic aid, few studies have examined the use of caffeinated gums, especially during half-time in team sports. The physiological (blood lactate, salivary hormone concentrations) and performance (repeated sprints, cognitive function) effects of consuming caffeine gum during a simulated half-time were examined. Professional academy rugby union players (n=14) completed this double-blind, randomized, counterbalanced study. Following pre-exercise measurements , players chewed a placebo (PL) gum for five min before a standardized warm-up and completing repeated sprint testing (RSSA1). Thereafter, during a 15 min simulated half-time period, players chewed either caffeine (CAF: 400 mg; 4.1 ± 0.5 mg·kg) or PL gum for five min before completing a second repeated sprint test (RSSA2). Blood lactate, salivary testosterone and cortisol concentrations, and indices of cognitive function (i.e., reaction time and Stroop test) were measured at baseline, pre-RSSA1, post-RSSA1, pre-RSSA2 and post-RSSA2. Sprint performance was not affected by CAF (P=0.995) despite slower sprint times following the first sprint of both RSSA tests (all P<0.002). Following half-time, salivary testosterone increased by 70% (+97±58 pg·mL) in CAF versus PLA (P<0.001) whereas salivary cortisol remained unchanged (P=0.307). Cognitive performance was unaffected by time and trial (all P>0.05). Although performance effects were absent, chewing caffeine gum increased the salivary testosterone concentrations of professional rugby union players over a simulated half-time. Practitioners may therefore choose to recommend caffeine gum between successive exercise bouts due to the increases in salivary testosterone observed; a variable associated with increased motivation and high-intensity exercise performance.

Compilation of selected marine radioecological data for the US Subseabed Program: Summaries of available radioecological concentration factors and biological half-lives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez, L.S.; Marietta, M.G.; Jackson, D.W.

1987-04-01

The US Subseabed Disposal Program has compiled an extensive concentration factor and biological half-life data base from the international marine radioecological literature. A microcomputer-based data management system has been implemented to provide statistical and graphic summaries of these data. The data base is constructed in a manner which allows subsets to be sorted using a number of interstudy variables such as organism category, tissue/organ category, geographic location (for in situ studies), and several laboratory-related conditions (e.g., exposure time and exposure concentration). This report updates earlier reviews and provides summaries of the tabulated data. In addition to the concentration factor/biological half-lifemore » data base, we provide an outline of other published marine radioecological works. Our goal is to present these data in a form that enables those concerned with predictive assessment of radiation dose in the marine environment to make a more judicious selection of data for a given application. 555 refs., 19 figs., 7 tabs.« less

Prehension of Half-Full and Half-Empty Glasses: Time and History Effects on Multi-Digit Coordination

PubMed Central

Sun, Yao; Zatsiorsky, Vladimir M.; Latash, Mark L.

2011-01-01

We explored how digit forces and indices of digit coordination depend on the history of getting to a particular set of task parameters during static prehension tasks. The participants held in the right hand an instrumented handle with a light-weight container attached on top of the handle. At the beginning of each trial, the container could be empty, filled to the half with water (0.4 l) or filled to the top (0.8 l). The water was pumped in/out of the container at a constant, slow rate over 10 s. At the end of each trial, the participants always held a half-filled container that has just been filled (Empty-Half), emptied (Full-Half), or stayed half-filled throughout the trial (Half-Only). Indices of co-variation (synergy indices) of elemental variables (forces and moments of force produced by individual digits) stabilizing such performance variables as total normal force, total tangetial force, and total moment of force were computed at two levels of an assumed control hierarchy. At the upper level, the task is shared between the thumb and virtual finger (an imagined digit with the mechanical action equal to that of the four fingers), while at the lower level, action of the virtual finger is shared among the actual four fingers. Filling or emptying the container led to a drop in the safety margin (proportion of grip force over the slipping threshold) below the values observed in the Half-Only condition. Synergy indices at both levels of the hierarchy showed changes over the Full-Half and Empty-Half condition. These changes could be monotonic (typical of moment of force and normal force) or non-monotonic (typical of tangential force). For both normal and tangential forces, higher synergy indices at the higher level of the hierarchy corresponded to lower indices at the lower level. Significant differences in synergy indices across conditions were seen at the final steady-state showing that digit coordination during steady holding an object is history dependent. The

Effect of repeated sprints on postprandial endothelial function and triacylglycerol concentrations in adolescent boys.

PubMed

Sedgwick, Matthew J; Morris, John G; Nevill, Mary E; Barrett, Laura A

2015-01-01

This study investigated whether repeated, very short duration sprints influenced endothelial function (indicated by flow-mediated dilation) and triacylglycerol concentrations following the ingestion of high-fat meals in adolescent boys. Nine adolescent boys completed two, 2-day main trials (control and exercise), in a counter-balanced, cross-over design. Participants were inactive on day 1 of the control trial but completed 40 × 6 s maximal cycle sprints on day 1 of the exercise trial. On day 2, capillary blood samples were collected and flow-mediated dilation measured prior to, and following, ingestion of a high-fat breakfast and lunch. Fasting flow-mediated dilation and plasma triacylglycerol concentration were similar in the control and exercise trial (P > 0.05). In the control trial, flow-mediated dilation was reduced by 20% and 27% following the high-fat breakfast and lunch; following exercise these reductions were negated (main effect trial, P < 0.05; interaction effect trial × time, P < 0.05). The total area under the plasma triacylglycerol concentration versus time curve was 13% lower on day 2 in the exercise trial compared to the control trial (8.65 (0.97) vs. 9.92 (1.16) mmol · l(-1) · 6.5 h, P < 0.05). These results demonstrate that repeated 6 s maximal cycle sprints can have beneficial effects on postprandial endothelial function and triacylglycerol concentrations in adolescent boys.

Practical Considerations for Determination of Glass Transition Temperature of a Maximally Freeze Concentrated Solution.

PubMed

Pansare, Swapnil K; Patel, Sajal Manubhai

2016-08-01

Glass transition temperature is a unique thermal characteristic of amorphous systems and is associated with changes in physical properties such as heat capacity, viscosity, electrical resistance, and molecular mobility. Glass transition temperature for amorphous solids is referred as (T g), whereas for maximally freeze concentrated solution, the notation is (T g'). This article is focused on the factors affecting determination of T g' for application to lyophilization process design and frozen storage stability. Also, this review provides a perspective on use of various types of solutes in protein formulation and their effect on T g'. Although various analytical techniques are used for determination of T g' based on the changes in physical properties associated with glass transition, the differential scanning calorimetry (DSC) is the most commonly used technique. In this article, an overview of DSC technique is provided along with brief discussion on the alternate analytical techniques for T g' determination. Additionally, challenges associated with T g' determination, using DSC for protein formulations, are discussed. The purpose of this review is to provide a practical industry perspective on determination of T g' for protein formulations as it relates to design and development of lyophilization process and/or for frozen storage; however, a comprehensive review of glass transition temperature (T g, T g'), in general, is outside the scope of this work.

Polyphenolic compounds with antioxidant potential and neuro-protective effect from Cimicifuga dahurica (Turcz.) Maxim.

PubMed

Qin, Rulan; Zhao, Ying; Zhao, Yudan; Zhou, Wanrong; Lv, Chongning; Lu, Jincai

2016-12-01

Three new phenolic compounds (1-3), along with five known compounds (4-8) were isolated from the rhizome of Cimicifuga dahurica (Turcz.) Maxim. Their structures were elucidated by spectroscopic methods including 1D-NMR, 2D-NMR and HR-MS techniques. DPPH method and protective effect on PC12 cells against H 2 O 2 -induced oxidative damage model were carried to evaluate the antioxidant capability of these compounds. Compound 5 showed significant antioxidant activity with IC 50 values 9.33μM in DPPH assay and compound 2 displayed marked neuro-protective effect with 87.65% cell viability at the concentration of 10μM. Additionally, the possible structure-activity relationships of these phenolic compounds were tentatively discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Glucose transporters and maximal transport are increased in endurance-trained rat soleus

NASA Technical Reports Server (NTRS)

Slentz, C. A.; Gulve, E. A.; Rodnick, K. J.; Henriksen, E. J.; Youn, J. H.; Holloszy, J. O.

1992-01-01

Voluntary wheel running induces an increase in the concentration of the regulatable glucose transporter (GLUT4) in rat plantaris muscle but not in soleus muscle (K. J. Rodnick, J. O. Holloszy, C. E. Mondon, and D. E. James. Diabetes 39: 1425-1429, 1990). Wheel running also causes hypertrophy of the soleus in rats. This study was undertaken to ascertain whether endurance training that induces enzymatic adaptations but no hypertrophy results in an increase in the concentration of GLUT4 protein in rat soleus (slow-twitch red) muscle and, if it does, to determine whether there is a concomitant increase in maximal glucose transport activity. Female rats were trained by treadmill running at 25 m/min up a 15% grade, 90 min/day, 6 days/wk for 3 wk. This training program induced increases of 52% in citrate synthase activity, 66% in hexokinase activity, and 47% in immunoreactive GLUT4 protein concentration in soleus muscles without causing hypertrophy. Glucose transport activity stimulated maximally with insulin plus contractile activity was increased to roughly the same extent (44%) as GLUT4 protein content in soleus muscle by the treadmill exercise training. In a second set of experiments, we examined whether a swim-training program increases glucose transport activity in the soleus in the presence of a maximally effective concentration of insulin. The swimming program induced a 44% increase in immunoreactive GLUT4 protein concentration. Glucose transport activity maximally stimulated with insulin was 62% greater in soleus muscle of the swimmers than in untrained controls. Training did not alter the basal rate of 2-deoxyglucose uptake.(ABSTRACT TRUNCATED AT 250 WORDS).

3 CFR - Maximizing the Effectiveness of Federal Programs and Functions Supporting Trade and Investment

Code of Federal Regulations, 2013 CFR

2013-01-01

... 3 The President 1 2013-01-01 2013-01-01 false Maximizing the Effectiveness of Federal Programs and Functions Supporting Trade and Investment Presidential Documents Other Presidential Documents Memorandum of February 17, 2012 Maximizing the Effectiveness of Federal Programs and Functions Supporting Trade and Investment Memorandum for the Heads of...

A New Look at the Impact of Maximizing on Unhappiness: Two Competing Mediating Effects

PubMed Central

Peng, Jiaxi; Zhang, Jiaxi; Zhang, Yan; Gong, Pinjia; Han, Bing; Sun, Hao; Cao, Fei; Miao, Danmin

2018-01-01

The current study aims to explore how the decision-making style of maximizing affects subjective well-being (SWB), which mainly focuses on the confirmation of the mediator role of regret and suppressing role of achievement motivation. A total of 402 Chinese undergraduate students participated in this study, in which they responded to the maximization, regret, and achievement motivation scales and SWB measures. Results suggested that maximizing significantly predicted SWB. Moreover, regret and achievement motivation (hope for success dimension) could completely mediate and suppress this effect. That is, two competing indirect pathways exist between maximizing and SWB. One pathway is through regret. Maximizing typically leads one to regret, which could negatively predict SWB. Alternatively, maximizing could lead to high levels of hope for success, which were positively correlated with SWB. Findings offered a complex method of thinking about the relationship between maximizing and SWB. PMID:29467694

Effect of Semirecumbent and Upright Body Position on Maximal and Submaximal Exercise Testing

ERIC Educational Resources Information Center

Scott, Alexander; Antonishen, Kevin; Johnston, Chris; Pearce, Terri; Ryan, Michael; Sheel, A. William; McKenzie, Don C.

2006-01-01

The study was designed to determine the effect of upright-posture (UP) versus semirecumbent (SR) cycling on commonly used measures of maximal and submaximal exercise capacity. Nine healthy, untrained men (M age = 27 years, SD = 4.8 years) underwent steady-state submaximal aerobic testing followed by a ramped test to determine maximal oxygen…

Using return on investment to maximize conservation effectiveness in Argentine grasslands

PubMed Central

Murdoch, William; Ranganathan, Jai; Polasky, Stephen; Regetz, James

2010-01-01

The rapid global loss of natural habitats and biodiversity, and limited resources, place a premium on maximizing the expected benefits of conservation actions. The scarcity of information on the fine-grained distribution of species of conservation concern, on risks of loss, and on costs of conservation actions, especially in developing countries, makes efficient conservation difficult. The distribution of ecosystem types (unique ecological communities) is typically better known than species and arguably better represents the entirety of biodiversity than do well-known taxa, so we use conserving the diversity of ecosystem types as our conservation goal. We define conservation benefit to include risk of conversion, spatial effects that reward clumping of habitat, and diminishing returns to investment in any one ecosystem type. Using Argentine grasslands as an example, we compare three strategies: protecting the cheapest land (“minimize cost”), maximizing conservation benefit regardless of cost (“maximize benefit”), and maximizing conservation benefit per dollar (“return on investment”). We first show that the widely endorsed goal of saving some percentage (typically 10%) of a country or habitat type, although it may inspire conservation, is a poor operational goal. It either leads to the accumulation of areas with low conservation benefit or requires infeasibly large sums of money, and it distracts from the real problem: maximizing conservation benefit given limited resources. Second, given realistic budgets, return on investment is superior to the other conservation strategies. Surprisingly, however, over a wide range of budgets, minimizing cost provides more conservation benefit than does the maximize-benefit strategy. PMID:21098281

Using return on investment to maximize conservation effectiveness in Argentine grasslands.

PubMed

Murdoch, William; Ranganathan, Jai; Polasky, Stephen; Regetz, James

2010-12-07

The rapid global loss of natural habitats and biodiversity, and limited resources, place a premium on maximizing the expected benefits of conservation actions. The scarcity of information on the fine-grained distribution of species of conservation concern, on risks of loss, and on costs of conservation actions, especially in developing countries, makes efficient conservation difficult. The distribution of ecosystem types (unique ecological communities) is typically better known than species and arguably better represents the entirety of biodiversity than do well-known taxa, so we use conserving the diversity of ecosystem types as our conservation goal. We define conservation benefit to include risk of conversion, spatial effects that reward clumping of habitat, and diminishing returns to investment in any one ecosystem type. Using Argentine grasslands as an example, we compare three strategies: protecting the cheapest land ("minimize cost"), maximizing conservation benefit regardless of cost ("maximize benefit"), and maximizing conservation benefit per dollar ("return on investment"). We first show that the widely endorsed goal of saving some percentage (typically 10%) of a country or habitat type, although it may inspire conservation, is a poor operational goal. It either leads to the accumulation of areas with low conservation benefit or requires infeasibly large sums of money, and it distracts from the real problem: maximizing conservation benefit given limited resources. Second, given realistic budgets, return on investment is superior to the other conservation strategies. Surprisingly, however, over a wide range of budgets, minimizing cost provides more conservation benefit than does the maximize-benefit strategy.

Partial agonists for α4β2 nicotinic receptors stimulate dopaminergic neuron firing with relatively enhanced maximal effects

PubMed Central

Chen, Ying; Broad, Lisa M; Phillips, Keith G; Zwart, Ruud

2012-01-01

BACKGROUND AND PURPOSE Partial agonists selective for α4β2 nicotinic ACh receptors have been developed for smoking cessation as they induce weak activation of native α4β2* receptors and inhibit effect of nicotine. However, it is unclear whether at brain functions there is an existence of receptor reserve that allows weak receptor activation to induce maximum physiological effects. We assessed the extent of α4β2 partial agonist-induced increase of firing rate in dopaminergic neurons and evaluated the influence of receptor reserve. EXPERIMENTAL APPROACH The relative maximal effects and potencies of six nicotinic agonists were assessed on recombinant human α4β2 and α7 receptors expressed in mammalian cell lines by measuring calcium influx. Agonist-induced increase of the spontaneous firing rate of dopaminergic neurons was recorded using microelectrodes in the ventral tegmental area of rat brain slices. KEY RESULTS All α4β2 partial and full agonists increased the firing rate concentration-dependently. Their sensitivity to subtype-selective antagonists showed predominant activation of native α4β2* receptors. However, partial agonists with relative maximal effects as low as 33% on α4β2 receptors maximally increased the firing rate and induced additional depolarization block of firing, demonstrating that partial activation of receptors caused the maximum increase in firing rate in the presence of a receptor reserve. CONCLUSIONS AND IMPLICATIONS Partial α4β2 agonists induced relatively enhanced effects on the firing rate of dopaminergic neurons, and the effect was mainly attributed to the existence of native α4β2* receptor reserve. The results have implications in the understanding of physiological effects and therapeutic efficacies of α4β2 partial agonists. PMID:21838750

Effects of In-Season Explosive Strength Training on Maximal Leg Strength, Jumping, Sprinting, and Intermittent Aerobic Performance in Male Handball Athletes.

PubMed

Hermassi, Souhail; Chelly, Mohamed Souhaiel; Fieseler, Georg; Bartels, Thomas; Schulze, Stephan; Delank, Karl-Stefan; Shephard, Roy J; Schwesig, René

2017-09-01

Background  Team handball is an intense ball sport with specific requirements on technical skills, tactical understanding, and physical performance. The ability of handball players to develop explosive efforts (e. g. sprinting, jumping, changing direction) is crucial to success. Objective  The purpose of this pilot study was to examine the effects of an in-season high-intensity strength training program on the physical performance of elite handball players. Materials and methods  Twenty-two handball players (a single national-level Tunisian team) were randomly assigned to a control group (CG; n = 10) or a training group (TG; n = 12). At the beginning of the pilot study, all subjects performed a battery of motor tests: one repetition maximum (1-RM) half-squat test, a repeated sprint test [6 × (2 × 15 m) shuttle sprints], squat jumps, counter movement jumps (CMJ), and the Yo-Yo intermittent recovery test level 1. The TG additionally performed a maximal leg strength program twice a week for 10 weeks immediately before engaging in regular handball training. Each strength training session included half-squat exercises to strengthen the lower limbs (80 - 95 % of 1-RM, 1 - 3 repetitions, 3 - 6 sets, 3 - 4 min rest between sets). The control group underwent no additional strength training. The motor test battery was repeated at the end of the study interventions. Results  In the TG, 3 parameters (maximal strength of lower limb: η² = 0.74; CMJ: η² = 0.70, and RSA best time: η² = 0.25) showed significant improvements, with large effect sizes (e. g. CMJ: d = 3.77). A reduction in performance for these same 3 parameters was observed in the CG (d = -0.24). Conclusions  The results support our hypothesis that additional strength training twice a week enhances the maximal strength of the lower limbs and jumping or repeated sprinting performance. There was no evidence of shuttle sprints ahead of regular

[Relation between dose, plasma concentration and therapeutic effect of theophylline in children with sleep apnea].

PubMed

Rodríguez-Palomares, C; Ugartechea, J C; Palma-Aguirre, J A; Juárez-Olguín, H; Calderón-Mandujano, B

1989-12-01

The plasma concentration of theophylline was determined in twelve children with infantile sleep apnea (average age 48.5 days). The purpose of the study was to correlate concentrations with the dosages given, the therapeutic response and any adverse effects which could arise. In addition, other pharmacokinetic values were found, half-life (t 1/2) and clearance concentrations (Clss). The oral maintenance dose used was 4 mg/kg/24 h. The serum concentration of theophylline was determined by a homogeneous immunoassay enzyme technique (EMIT). A bad correlation was found (r = 0.45) between the oral dosage given and the plasma concentrations found. This was probably due to variations in the clearance of the drug. Yet, plasma concentrations fell between 3.0 and 12.6 micrograms/mL, enough to satisfactorily control apneic episodes in all the children included in the study without undesirable side-effects. Only one patient had some trouble in falling asleep and showed signs of irritability. The half-life was 13.30 +/- 7.46 hours and Clss was 36.64 +/- 12.98 mL/h/kg. In general, our results correlate with those reported in the literature. The accuracy of the pharmacokinetic parameters with two samples is reliable, therefore avoiding the use of multiple sampling in this group of children.

Effect of maximal-intensity exercise on systemic nitro-oxidative stress in men and women.

PubMed

Wiecek, Magdalena; Maciejczyk, Marcin; Szymura, Jadwiga; Szygula, Zbigniew

2017-07-01

The aim of this study was to test the hypotheses: (1) there is a negative correlation between protein and lipid oxidative damage following maximal-intensity exercise, and oxygen uptake and work intensity (%VO 2max ) at the respiratory compensation point (RCP) in women and men; (2) nitro-oxidative stress following maximal-intensity exercise results from the intensification of anaerobic processes and muscle fibre micro-damage. Study participants comprised 20 women (21.34±1.57 years) and 20 men (21.97±1.41 years) who performed a treadmill incremental test (IT); VO 2max : 45.08 ± 0.91 and 57.38 ± 1.22 mL kg -1  min -1 for women and men, respectively. The oxidized low-density lipoprotein (ox-LDL), 3-nitrotyrosine (3-NT) concentration and creatine kinase (CK) as well as lactate dehydrogenase (LDH) activity were measured in the blood serum, and total antioxidative capacity (TAC) and lactate concentration (Lac) were determined in blood plasma before and after IT. After the IT, increases in ox-LDL, 3-NT, CK, and LDH were seen in both groups (P < 0.05). After the IT, an increase in the TAC was only observed in women (P < 0.05). The post-exercise-induced increase in Lac was significantly higher in men than in women. Only in the group of women was a positive correlation (P < 0.05) between the post-exercise increase in TAC and changes in CK activity and LDH found. The gain of ox-LDL and 3-NT following maximal-intensity exercise is independent of VO 2max , oxygen consumption and exercise intensity at RCP. This increase of ox-LDL and 3-NT is indicative of similar lipid and protein damage in women and men. A significant increase in TAC in women following maximal-intensity exercise is the result of muscle fibre micro-injuries.

Persistence and Effective Half-Life of Chemical Warfare Agent VX on Grass Foliage

DTIC Science & Technology

2017-08-01

obtain results applicable to VX- contaminated battlefields. The Effective Half-Life of VX on grass foliage was determined as the net effect of factors...Soldiers on VX- contaminated battlefields. 15. SUBJECT TERMS Chemical warfare agent (CWA) Agent–plant Echinochloa crus-galli Foliage Effective Half...The use of either trade or manufacturers ’ names in this report does not constitute an official endorsement of any commercial products. This report may

AUC-Maximizing Ensembles through Metalearning.

PubMed

LeDell, Erin; van der Laan, Mark J; Petersen, Maya

2016-05-01

Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree.

AUC-Maximizing Ensembles through Metalearning

PubMed Central

LeDell, Erin; van der Laan, Mark J.; Peterson, Maya

2016-01-01

Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree. PMID:27227721

Effects of WIN 55,212-2 mesylate on the anticonvulsant action of lamotrigine, oxcarbazepine, pregabalin and topiramate against maximal electroshock-induced seizures in mice.

PubMed

Luszczki, Jarogniew J; Wlaz, Aleksandra; Karwan, Slawomir; Florek-Luszczki, Magdalena; Czuczwar, Stanislaw J

2013-11-15

The aim of this study was to determine the effect of WIN 55,212-2 mesylate (WIN - a non-selective cannabinoid CB1 and CB2 receptor agonist) on the protective action of four second-generation antiepileptic drugs (lamotrigine, oxcarbazepine, pregabalin and topiramate) in the mouse maximal electroshock seizure model. Tonic hind limb extension (seizure activity) was evoked in adult male albino Swiss mice by a current (sine-wave, 25 mA, 500 V, 50 Hz, 0.2s stimulus duration) delivered via auricular electrodes. Drug-related adverse effects were ascertained by use of the chimney test (evaluating motor performance), the step-through passive avoidance task (assessing long-term memory) and the grip-strength test (evaluating skeletal muscular strength). Total brain concentrations of antiepileptic drugs were measured by high-pressure liquid chromatography to ascertain any pharmacokinetic contribution to the observed antiseizure effect. Results indicate that WIN (5mg/kg, i.p.) significantly enhanced the anticonvulsant action of lamotrigine (P<0.05), pregabalin (P<0.001) and topiramate (P<0.05), but not that of oxcarbazepine in the maximal electroshock-induced tonic seizure test in mice. Furthermore, none of the investigated combinations of WIN with antiepileptic drugs were associated with any concurrent adverse effects with regards to motor performance, long-term memory or muscular strength. Pharmacokinetic characterization revealed that WIN had no impact on total brain concentrations of lamotrigine, oxcarbazepine, pregabalin and topiramate in mice. These preclinical data would suggest that WIN in combination with lamotrigine, pregabalin and topiramate is associated with beneficial anticonvulsant pharmacodynamic interactions in the maximal electroshock-induced tonic seizure test. © 2013 Published by Elsevier B.V.

Effect of pH and nitrite concentration on nitrite oxidation rate.

PubMed

Jiménez, E; Giménez, J B; Ruano, M V; Ferrer, J; Serralta, J

2011-10-01

The effect of pH and nitrite concentration on the activity of the nitrite oxidizing bacteria (NOB) in an activated sludge reactor has been determined by means of laboratory batch experiments based on respirometric techniques. The bacterial activity was measured at different pH and at different total nitrite concentrations (TNO₂). The experimental results showed that the nitrite oxidation rate (NOR) depends on the TNO₂ concentration independently of the free nitrous acid (FNA) concentration, so FNA cannot be considered as the real substrate for NOB. NOB were strongly affected by low pH values (no activity was detected at pH 6.5) but no inhibition was observed at high pH values (activity was nearly the same for the pH range 7.5-9.95). A kinetic expression for nitrite oxidation process including switch functions to model the effect of TNO₂ concentration and pH inhibition is proposed. Substrate half saturation constant and pH inhibition constants have been obtained. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of maximal dynamic exercise on exhaled ethane and carbon monoxide levels in human, equine, and canine athletes.

PubMed

Wyse, Cathy; Cathcart, Andy; Sutherland, Rona; Ward, Susan; McMillan, Lesley; Gibson, Graham; Padgett, Miles; Skeldon, Kenneth

2005-06-01

Exercise-induced oxidative stress (EIOS) refers to a condition where the balance of free radical production and antioxidant systems is disturbed during exercise in favour of pro-oxidant free radicals. Breath ethane is a product of free radical-mediated oxidation of cell membrane lipids and is considered to be a reliable marker of oxidative stress. The heatshock protein, haem oxygenase, is induced by oxidative stress and degrades haemoglobin to bilirubin, with concurrent production of carbon monoxide (CO). The aim of this study was to investigate the effect of maximal exercise on exhaled ethane and CO in human, canine, and equine athletes. Human athletes (n = 8) performed a maximal exercise test on a treadmill, and canine (n = 12) and equine (n = 11) athletes exercised at gallop on a sand racetrack. Breath samples were taken at regular intervals during exercise in the human athletes, and immediately before and after exercise in the canine and equine athletes. Breath samples were stored in gas-impermeable bags for analysis of ethane by laser spectroscopy, and CO was measured directly using an electrochemical CO monitor. Maximal exercise was associated with significant increases in exhaled ethane in the human, equine, and canine athletes. Decreased concentrations of exhaled CO were detected after maximal exercise in the human athletes, but CO was rarely detectable in the canine and equine athletes. The ethane breath test allows non-invasive and real-time detection of oxidative stress, and this method will facilitate further investigation of the processes mediating EIOS in human and animal athletes.

Changes of glucose utilization by erythrocytes, lactic acid concentration in the serum and blood cells, and haematocrit value during one hour rest after maximal effort in individuals differing in physical efficiency.

PubMed

Tomasik, M

1982-01-01

Glucose utilization by the erythrocytes, lactic acid concentration in the blood and erythrocytes, and haematocrit value were determined before exercise and during one hour rest following maximal exercise in 97 individuals of either sex differing in physical efficiency. In the investigations reported by the author individuals with strikingly high physical fitness performed maximal work one-third greater than that performed by individuals with medium fitness. The serum concentration of lactic acid was in all individuals above the resting value still after 60 minutes of rest. On the other hand, this concentration returned to the normal level in the erythrocytes but only in individuals with strikingly high efficiency. Glucose utilization by the erythrocytes during the restitution period was highest immediately after the exercise in all studied individuals and showed a tendency for more rapid return to resting values again in individuals with highest efficiency. The investigation of very efficient individuals repeated twice demonstrated greater utilization of glucose by the erythrocytes at the time of greater maximal exercise. This was associated with greater lactic acid concentration in the serum and erythrocytes throughout the whole one-hour rest period. The observed facts suggest an active participation of erythrocytes in the process of adaptation of the organism to exercise.

The repeated bout effect of typical lower body strength training sessions on sub-maximal running performance and hormonal response.

PubMed

Doma, Kenji; Schumann, Moritz; Sinclair, Wade H; Leicht, Anthony S; Deakin, Glen B; Häkkinen, Keijo

2015-08-01

This study examined the effects of two typical strength training sessions performed 1 week apart (i.e. repeated bout effect) on sub-maximal running performance and hormonal. Fourteen resistance-untrained men (age 24.0 ± 3.9 years; height 1.83 ± 0.11 m; body mass 77.4 ± 14.0 kg; VOpeak 48.1 ± 6.1 M kg(-1) min(-1)) undertook two bouts of high-intensity strength training sessions (i.e. six-repetition maximum). Creatine kinase (CK), delayed-onset muscle soreness (DOMS), counter-movement jump (CMJ) as well as concentrations of serum testosterone, cortisol and testosterone/cortisol ratio (T/C) were examined prior to and immediately post, 24 (T24) and 48 (T48) h post each strength training bout. Sub-maximal running performance was also conducted at T24 and T48 of each bout. When measures were compared between bouts at T48, the degree of elevation in CK (-58.4 ± 55.6 %) and DOMS (-31.43 ± 42.9 %) and acute reduction in CMJ measures (4.1 ± 5.4 %) were attenuated (p < 0.05) following the second bout. Cortisol was increased until T24 (p < 0.05) although there were no differences between bouts and no differences were found for testosterone and T/C ratio (p > 0.05). Sub-maximal running performance was impaired until T24, although changes were not attenuated following the second bout. The initial bout appeared to provide protection against a number of muscle damage indicators suggesting a greater need for recovery following the initial session of typical lower body resistance exercises in resistance-untrained men although sub-maximal running should be avoided following the first two sessions.

Strategies for maximizing clinical effectiveness in the treatment of schizophrenia.

PubMed

Tandon, Rajiv; Targum, Steven D; Nasrallah, Henry A; Ross, Ruth

2006-11-01

The ultimate clinical objective in the treatment of schizophrenia is to enable affected individuals to lead maximally productive and personally meaningful lives. As with other chronic diseases that lack a definitive cure, the individual's service/recovery plan must include treatment interventions directed towards decreasing manifestations of the illness, rehabilitative services directed towards enhancing adaptive skills, and social support mobilization aimed at optimizing function and quality of life. In this review, we provide a conceptual framework for considering approaches for maximizing the effectiveness of the array of treatments and other services towards promoting recovery of persons with schizophrenia. We discuss pharmacological, psychological, and social strategies that decrease the burden of the disease of schizophrenia on affected individuals and their families while adding the least possible burden of treatment. In view of the multitude of treatments necessary to optimize outcomes for individuals with schizophrenia, effective coordination of these services is essential. In addition to providing best possible clinical assessment and pharmacological treatment, the psychiatrist must function as an effective leader of the treatment team. To do so, however, the psychiatrist must be knowledgeable about the range of available services, must have skills in clinical-administrative leadership, and must accept the responsibility of coordinating the planning and delivery of this multidimensional array of treatments and services. Finally, the effectiveness of providing optimal individualized treatment/rehabilitation is best gauged by measuring progress on multiple effectiveness domains. Approaches for efficient and reliable assessment are discussed.

Relationship between arterial oxygen desaturation and ventilation during maximal exercise.

PubMed

Miyachi, M; Tabata, I

1992-12-01

The purpose of the present study was to investigate the contribution of ventilation to arterial O2 desaturation during maximal exercise. Nine untrained subjects and 22 trained long-distance runners [age 18-36 yr, maximal O2 uptake (VO2max) 48-74 ml.min-1 x kg-1] volunteered to participate in the study. The subjects performed an incremental exhaustive cycle ergometry test at 70 rpm of pedaling frequency, during which arterial O2 saturation (SaO2) and ventilatory data were collected every minute. SaO2 was estimated with a pulse oximeter. A significant positive correlation was found between SaO2 and end-tidal PO2 (PETO2; r = 0.72, r2 = 0.52, P < 0.001) during maximal exercise. These statistical results suggest that approximately 50% of the variability of SaO2 can be accounted for by differences in PETO2, which reflects alveolar PO2. Furthermore, PETO2 was highly correlated with the ventilatory equivalent for O2 (VE/VO2; r = 0.91, P < 0.001), which indicates that PETO2 could be the result of ventilation stimulated by maximal exercise. Finally, SaO2 was positively related to VE/VO2 during maximal exercise (r = 0.74, r2 = 0.55, P < 0.001). Therefore, one-half of the arterial O2 desaturation occurring during maximal exercise may be explained by less hyperventilation, specifically for our subjects, who demonstrated a wide range of trained states. Furthermore, we found an indirect positive correlation between SaO2 and ventilatory response to CO2 at rest (r = 0.45, P < 0.05), which was mediated by ventilation during maximal exercise. These data also suggest that ventilation is an important factor for arterial O2 desaturation during maximal exercise.

Intrarater Reliability of Muscle Strength and Hamstring to Quadriceps Strength Imbalance Ratios During Concentric, Isometric, and Eccentric Maximal Voluntary Contractions Using the Isoforce Dynamometer.

PubMed

Mau-Moeller, Anett; Gube, Martin; Felser, Sabine; Feldhege, Frank; Weippert, Matthias; Husmann, Florian; Tischer, Thomas; Bader, Rainer; Bruhn, Sven; Behrens, Martin

2017-08-17

To determine intrasession and intersession reliability of strength measurements and hamstrings to quadriceps strength imbalance ratios (H/Q ratios) using the new isoforce dynamometer. Repeated measures. Exercise science laboratory. Thirty healthy subjects (15 females, 15 males, 27.8 years). Coefficient of variation (CV) and intraclass correlation coefficients (ICC) were calculated for (1) strength parameters, that is peak torque, mean work, and mean power for concentric and eccentric maximal voluntary contractions; isometric maximal voluntary torque (IMVT); rate of torque development (RTD), and (2) H/Q ratios, that is conventional concentric, eccentric, and isometric H/Q ratios (Hcon/Qcon at 60 deg/s, 120 deg/s, and 180 deg/s, Hecc/Qecc at -60 deg/s and Hiso/Qiso) and functional eccentric antagonist to concentric agonist H/Q ratios (Hecc/Qcon and Hcon/Qecc). High reliability: CV <10%, ICC >0.90; moderate reliability: CV between 10% and 20%, ICC between 0.80 and 0.90; low reliability: CV >20%, ICC <0.80. (1) Strength parameters: (a) high intrasession reliability for concentric, eccentric, and isometric measurements, (b) moderate-to-high intersession reliability for concentric and eccentric measurements and IMVT, and (c) moderate-to-high intrasession reliability but low intersession reliability for RTD. (2) H/Q ratios: (a) moderate-to-high intrasession reliability for conventional ratios, (b) high intrasession reliability for functional ratios, (c) higher intersession reliability for Hcon/Qcon and Hiso/Qiso (moderate to high) than Hecc/Qecc (low to moderate), and (d) higher intersession reliability for conventional H/Q ratios (low to high) than functional H/Q ratios (low to moderate). The results have confirmed the reliability of strength parameters and the most frequently used H/Q ratios.

Effect of gender on fatigue and recovery following maximal intensity repeated sprint performance.

PubMed

Laurent, C M; Green, J M; Bishop, P A; Sjökvist, J; Schumacker, R E; Richardson, M T; Curtner-Smith, M

2010-09-01

This study investigated the effects of gender on repeated, maximal-intensity intermittent sprint exercise following variable day-to-day recovery periods. Sixteen volunteers (8 men, 8 women) performed four trials of high-intensity intermittent sprint exercise consisting of three bouts of eight 30 m sprints (total of 24 sprints). Following completion of the baseline trial, in repeated-measures design, participants were assigned, in counter-balanced order, variable recovery periods of 24, 48, and 72 h whereupon they repeated an identical exercise trial. Results from a series of 4 (trial) x 3 (bout) repeated measures ANOVAs revealed men produced significantly (P < 0.01) faster times throughout all bouts and trials of repeated sprint exercise. Additionally, women exhibited significantly lower (P < 0.05) blood lactate concentration and significantly lower (P < 0.05) decrement in performance, indicating increased resistance to fatigue during repeated exercise sessions. There were no significant differences (P > 0.05) between genders for heart rate or rating of perceived exertion during or following trials. There were no significant differences for overall sprint performance within either gender among trials. These results indicate men, while able to produce higher absolute power outputs (i.e., lower sprint time), demonstrate higher decrement scores within a trial compared to women, thus suggesting women may recover faster and fatigue less. Also, gender differences affecting recovery within in a trial were observed to be diminished between trials (i.e., day-to-day recovery) of maximal intermittent sprint work evidenced by the observed stability of performance between trials following various recovery durations.

Effects of Variable Resistance Training on Maximal Strength: A Meta-Analysis.

PubMed

Soria-Gila, Miguel A; Chirosa, Ignacio J; Bautista, Iker J; Baena, Salvador; Chirosa, Luis J

2015-11-01

Variable resistance training (VRT) methods improve the rate of force development, coordination between antagonist and synergist muscles, the recruitment of motor units, and reduce the drop in force produced in the sticking region. However, the beneficial effects of long-term VRT on maximal strength both in athletes and untrained individuals have been much disputed. The purpose of this study was to compare in a meta-analysis the effects of a long-term (≥7 weeks) VRT program using chains or elastic bands and a similar constant resistance program in both trained adults practicing different sports and untrained individuals. Intervention effect sizes were compared among investigations meeting our selection and inclusion criteria using a random-effects model. The published studies considered were those addressing VRT effects on the 1 repetition maximum. Seven studies involving 235 subjects fulfilled the selection and inclusion criteria. Variable resistance training led to a significantly greater mean strength gain (weighted mean difference: 5.03 kg; 95% confidence interval: 2.26-7.80 kg; Z = 3.55; p < 0.001) than the gain recorded in response to conventional weight training. Long-term VRT training using chains or elastic bands attached to the barbell emerged as an effective evidence-based method of improving maximal strength both in athletes with different sports backgrounds and untrained subjects.

A Brief Review of Effective Teaching Practices That Maximize Student Engagement

ERIC Educational Resources Information Center

Harbour, Kristin E.; Evanovich, Lauren L.; Sweigart, Chris A.; Hughes, Lindsay E.

2015-01-01

What teachers do and how students perform intersect, making teachers a critical factor for determining student success. When teachers use effective practices, they maximize the probability that students will be actively engaged in instruction. Student engagement is one of the most well-established predictors of achievement; when students are more…

Maximization of beta-galactosidase production: a simultaneous investigation of agitation and aeration effects.

PubMed

Alves, Fernanda Germano; Filho, Francisco Maugeri; de Medeiros Burkert, Janaína Fernandes; Kalil, Susana Juliano

2010-03-01

In this work, the agitation and aeration effects in the maximization of the beta-galactosidase production from Kluyveromyces marxianus CCT 7082 were investigated simultaneously, in relation to the volumetric enzyme activity and the productivity, as well as the analysis of the lactose consumption and production of glucose, and galactose of this process. Agitation and aeration effects were studied in a 2 L batch stirred reactor. A central composite design (2(2) trials plus three central points) was carried out. Agitation speed varied from 200 to 500 rpm and aeration rate from 0.5 to 1.5 vvm. It has been shown in this study that the volumetric enzyme production was strongly influenced by mixing conditions, while aeration was shown to be less significant. Linear models for activity and productivity due to agitation and aeration were obtained. The favorable condition was 500 rpm and 1.5 vvm, which lead to the best production of 17 U mL(-1) for enzymatic activity, 1.2 U mL(-1) h(-1) for productivity in 14 h of process, a cellular concentration of 11 mg mL(-1), and a 167.2 h(-1) volumetric oxygen transfer coefficient.

Optimal technique for maximal forward rotating vaults in men's gymnastics.

PubMed

Hiley, Michael J; Jackson, Monique I; Yeadon, Maurice R

2015-08-01

In vaulting a gymnast must generate sufficient linear and angular momentum during the approach and table contact to complete the rotational requirements in the post-flight phase. This study investigated the optimization of table touchdown conditions and table contact technique for the maximization of rotation potential for forwards rotating vaults. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a handspring double somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to maximize post-flight rotation potential (the product of angular momentum and flight time) for a forwards rotating vault. It was found that the maximized rotation potential was sufficient to produce a handspring double piked somersault vault. The corresponding optimal touchdown configuration exhibited hip flexion in contrast to the hyperextended configuration required for maximal height. Increasing touchdown velocity and angular momentum lead to additional post-flight rotation potential. By increasing the horizontal velocity at table touchdown, within limits obtained from recorded performances, the handspring double somersault tucked with one and a half twists, and the handspring triple somersault tucked became theoretically possible. Copyright © 2015 Elsevier B.V. All rights reserved.

Predictive Variables of Half-Marathon Performance for Male Runners

PubMed Central

Gómez-Molina, Josué; Ogueta-Alday, Ana; Camara, Jesus; Stickley, Christoper; Rodríguez-Marroyo, José A.; García-López, Juan

2017-01-01

The aims of this study were to establish and validate various predictive equations of half-marathon performance. Seventy-eight half-marathon male runners participated in two different phases. Phase 1 (n = 48) was used to establish the equations for estimating half-marathon performance, and Phase 2 (n = 30) to validate these equations. Apart from half-marathon performance, training-related and anthropometric variables were recorded, and an incremental test on a treadmill was performed, in which physiological (VO2max, speed at the anaerobic threshold, peak speed) and biomechanical variables (contact and flight times, step length and step rate) were registered. In Phase 1, half-marathon performance could be predicted to 90.3% by variables related to training and anthropometry (Equation 1), 94.9% by physiological variables (Equation 2), 93.7% by biomechanical parameters (Equation 3) and 96.2% by a general equation (Equation 4). Using these equations, in Phase 2 the predicted time was significantly correlated with performance (r = 0.78, 0.92, 0.90 and 0.95, respectively). The proposed equations and their validation showed a high prediction of half-marathon performance in long distance male runners, considered from different approaches. Furthermore, they improved the prediction performance of previous studies, which makes them a highly practical application in the field of training and performance. Key points The present study obtained four equations involving anthropometric, training, physiological and biomechanical variables to estimate half-marathon performance. These equations were validated in a different population, demonstrating narrows ranges of prediction than previous studies and also their consistency. As a novelty, some biomechanical variables (i.e. step length and step rate at RCT, and maximal step length) have been related to half-marathon performance. PMID:28630571

Centromere Locations in Brassica A and C Genomes Revealed Through Half-Tetrad Analysis

PubMed Central

Mason, Annaliese S.; Rousseau-Gueutin, Mathieu; Morice, Jérôme; Bayer, Philipp E.; Besharat, Naghmeh; Cousin, Anouska; Pradhan, Aneeta; Parkin, Isobel A. P.; Chèvre, Anne-Marie; Batley, Jacqueline; Nelson, Matthew N.

2016-01-01

Locating centromeres on genome sequences can be challenging. The high density of repetitive elements in these regions makes sequence assembly problematic, especially when using short-read sequencing technologies. It can also be difficult to distinguish between active and recently extinct centromeres through sequence analysis. An effective solution is to identify genetically active centromeres (functional in meiosis) by half-tetrad analysis. This genetic approach involves detecting heterozygosity along chromosomes in segregating populations derived from gametes (half-tetrads). Unreduced gametes produced by first division restitution mechanisms comprise complete sets of nonsister chromatids. Along these chromatids, heterozygosity is maximal at the centromeres, and homologous recombination events result in homozygosity toward the telomeres. We genotyped populations of half-tetrad-derived individuals (from Brassica interspecific hybrids) using a high-density array of physically anchored SNP markers (Illumina Brassica 60K Infinium array). Mapping the distribution of heterozygosity in these half-tetrad individuals allowed the genetic mapping of all 19 centromeres of the Brassica A and C genomes to the reference Brassica napus genome. Gene and transposable element density across the B. napus genome were also assessed and corresponded well to previously reported genetic map positions. Known centromere-specific sequences were located in the reference genome, but mostly matched unanchored sequences, suggesting that the core centromeric regions may not yet be assembled into the pseudochromosomes of the reference genome. The increasing availability of genetic markers physically anchored to reference genomes greatly simplifies the genetic and physical mapping of centromeres using half-tetrad analysis. We discuss possible applications of this approach, including in species where half-tetrads are currently difficult to isolate. PMID:26614742

Centromere Locations in Brassica A and C Genomes Revealed Through Half-Tetrad Analysis.

PubMed

Mason, Annaliese S; Rousseau-Gueutin, Mathieu; Morice, Jérôme; Bayer, Philipp E; Besharat, Naghmeh; Cousin, Anouska; Pradhan, Aneeta; Parkin, Isobel A P; Chèvre, Anne-Marie; Batley, Jacqueline; Nelson, Matthew N

2016-02-01

Locating centromeres on genome sequences can be challenging. The high density of repetitive elements in these regions makes sequence assembly problematic, especially when using short-read sequencing technologies. It can also be difficult to distinguish between active and recently extinct centromeres through sequence analysis. An effective solution is to identify genetically active centromeres (functional in meiosis) by half-tetrad analysis. This genetic approach involves detecting heterozygosity along chromosomes in segregating populations derived from gametes (half-tetrads). Unreduced gametes produced by first division restitution mechanisms comprise complete sets of nonsister chromatids. Along these chromatids, heterozygosity is maximal at the centromeres, and homologous recombination events result in homozygosity toward the telomeres. We genotyped populations of half-tetrad-derived individuals (from Brassica interspecific hybrids) using a high-density array of physically anchored SNP markers (Illumina Brassica 60K Infinium array). Mapping the distribution of heterozygosity in these half-tetrad individuals allowed the genetic mapping of all 19 centromeres of the Brassica A and C genomes to the reference Brassica napus genome. Gene and transposable element density across the B. napus genome were also assessed and corresponded well to previously reported genetic map positions. Known centromere-specific sequences were located in the reference genome, but mostly matched unanchored sequences, suggesting that the core centromeric regions may not yet be assembled into the pseudochromosomes of the reference genome. The increasing availability of genetic markers physically anchored to reference genomes greatly simplifies the genetic and physical mapping of centromeres using half-tetrad analysis. We discuss possible applications of this approach, including in species where half-tetrads are currently difficult to isolate. Copyright © 2016 by the Genetics Society of America.

Influence of training and a maximal exercise test in analytical variability of muscular, hepatic, and cardiovascular biochemical variables.

PubMed

Romagnoli, Marco; Alis, Rafael; Aloe, Rosalia; Salvagno, Gian Luca; Basterra, Javier; Pareja-Galeano, Helios; Sanchis-Gomar, Fabian; Lippi, Giuseppe

2014-04-01

Short, middle, and long-term exercise, as well as the relative intensity of the physical effort, may influence a broad array of laboratory results, and it is thereby of pivotal importance to appropriately differentiate the 'physiologic' from the 'pathological' effects of exercise. Therefore, the values of some biomarkers in physically active subjects may be cautiously interpreted since the results may fall outside the conventional reference ranges. It has been demonstrated that middle and long-term endurance and/or strenuous exercise triggers transient elevations of muscular and cardiac biomarkers. However, no data have been published about the effect of short-term maximal exercise test on the most useful muscular, hepatic and cardiovascular biomarkers. The aim of the present study was to assess the baseline concentrations of muscular, hepatic, and cardiovascular makers between trained and untrained subjects, along with changes induced by maximal exercise test. We measured C reactive protein (CRP), procalcitonin (PCT), gamma glutamyltransferase (GGT), creatine kinase-MB isoenzyme (CK-MB), Hs-TnT, NT-proBNP, CK, LDH, AST, and ALT in serum samples of physically active (trained) and physically inactive (sedentary) male collected before, immediately after a maximal exercise test and after a 30-min recovery period. Trained subjects tend to have significantly raised base concentrations of CK, CK-MB, ALT, and LDH compared to sedentary individuals, and this can be clearly interpreted as a mild injury of skeletal muscle. A single maximal exercise was also effective to transiently increase the concentrations of NT-proBNP, but not those of Hs-TnT, thus suggesting that the cardiac involvement is mostly benign in nature.

Observation of orbital order in the half-filled 4 f Gd compound

DOE PAGES

Jang, H.; Kang, B. Y.; Cho, B. K.; ...

2016-11-18

Half-filled electron systems, even with the maximized spin angular moment, have been given little attention because of their zero-orbital angular moment according to Hund’s rule. Nevertheless, there are several measurements that show evidence of a nonzero orbital moment as well as spin-orbit coupling. Here we report for the first time the orbital order in a half-filled 4f-electron system GdB 4, using the resonant soft x-ray scattering at Gd M 4,5-edges. Furthermore, we discovered that the development of this orbital order is strongly coupled with the antiferromagnetic spin order. Lastly, these results clearly demonstrate that even in half-filled electron systems themore » orbital angular moment can be an important parameter to describe material properties, and may provide significant opportunities for tailoring new correlated electron systems.« less

Observation of orbital order in the half-filled 4 f Gd compound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jang, H.; Kang, B. Y.; Cho, B. K.

Half-filled electron systems, even with the maximized spin angular moment, have been given little attention because of their zero-orbital angular moment according to Hund’s rule. Nevertheless, there are several measurements that show evidence of a nonzero orbital moment as well as spin-orbit coupling. Here we report for the first time the orbital order in a half-filled 4f-electron system GdB 4, using the resonant soft x-ray scattering at Gd M 4,5-edges. Furthermore, we discovered that the development of this orbital order is strongly coupled with the antiferromagnetic spin order. Lastly, these results clearly demonstrate that even in half-filled electron systems themore » orbital angular moment can be an important parameter to describe material properties, and may provide significant opportunities for tailoring new correlated electron systems.« less

Relationships between maximal strength of lower limb, anthropometric characteristics and fundamental explosive performance in handball players.

PubMed

Hermassi, Souhail; Chelly, Mohamed Souhaiel; Wagner, Herbert; Fieseler, Georg; Schulze, Stephan; Delank, Karl-Stefan; Shephard, Roy J; Schwesig, René

2018-02-14

 The purpose of this study was to examine relationships between lower body muscular strength, anthropometric characteristics and several measures of explosive performance in elite team-handball players.  22 male elite team-handball players (age: 19.1 ± 1.7 years) were studied during the competitive season. Standard anthropometric and body composition measures included body mass index, lower limb and thigh muscle volume, and body fat percentage. Maximal leg strength was determined by a one-repetition maximum (1-RM) half back-squat. Vertical jump performance was assessed using a squat jump (SJ) and a counter movement jump (CMJ). Repeated shuttle-sprint ability (RSA) was tested by 6 (2 × 15 m) shuttle sprints with 20 s of active recovery intervals. The best time in a single shuttle sprint (30m; RSA best ), fastest total time (RSA TT ) and RSA test performance decrement (RSA dec ) were recorded. Agility was measured using a modified T-half test (MAT). Throwing velocities of jump shooting and 3-step throwing were recorded by digital video camera.  The explained variance of 1-RM half-back-squats ranged from 0.2 % (RSA% Fatigue Index) to 70.1 % (CMJ). Four out of 8 variables (RSA Best Time, CMJ, SJ, throwing velocity of jump shoot) demonstrated an r 2  > 0.5. Jump performances seemed closely related to 1-RM half-back-squats. Furthermore, 1-RM half-back-squats were positively correlated with leg and thigh muscle volumes (r = 0.652, r = 0.768).  The anthropometric characteristics and some physical performance tests are closely related to the maximal strength performance of handball players. Coaches should focus on maximal strength training programs for the lower limbs when seeking improvements in the throwing velocity and jump performance of handball players. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of clavulanic acid on minimal inhibitory concentrations of 16 antimicrobial agents tested against Legionella pneumophila.

PubMed Central

Pohlod, D J; Saravolatz, L D; Quinn, E L; Somerville, M M

1980-01-01

A total of 15 Legionella pneumophilia isolated were tested against 16 antimicrobial agents used singly and in combination with clavulanic acid. When combined with clavulanic acid, 4 of the 16 antimicrobial agents produced no enhanced effect. However, the minimal inhibitory concentrations of 12 of the antimicrobial agents were reduced by one-half to one-third when in combination with clavulanic acid. These reductions reflected only a one-dilution decrease, however, in the original minimal inhibitory concentrations. Thus, clavulanic acid combinations appear to be only nominally effective beta-lactamase inhibitors against L. pneumophilia. PMID:6969575

Maximal Oxygen Intake and Maximal Work Performance of Active College Women.

ERIC Educational Resources Information Center

Higgs, Susanne L.

Maximal oxygen intake and associated physiological variables were measured during strenuous exercise on women subjects (N=20 physical education majors). Following assessment of maximal oxygen intake, all subjects underwent a performance test at the work level which had elicited their maximal oxygen intake. Mean maximal oxygen intake was 41.32…

Effects of elevated ozone concentration on the degradation of dichlorprop in soil.

PubMed

Haberhauer, G; Temmel, B; Gerzabek, M H

1999-10-01

An aerobic degradation study was conducted to estimate possible effects of elevated ozone concentration in air on the behaviour of dichlorprop. An average ozone concentration of 80 nL L-1 was chosen, which often occurs close to congested areas during late spring and summer. A control soil and an ozone exposed soil were kept under same conditions such as temperature, air flow and soil humidity. The use of 14C-labelled dichlorprop allowed to examine the fate of dichlorprop and follow the degradation products in soil. Exhaustive extraction of both soils yielded several fractions containing dichlorprop residues. Half lives of dichlorprop of both treatments were 5 days. After 32 days most of the residues in soil remained in the non extractable fraction. The elevated ozone concentration showed no significant effects on the degradation behaviour of dichlorprop and its metabolites but significant differences were found for the behaviour of the nonextractable residues and of the release of carbon dioxide, which were higher for control soil in comparison to the ozone variant. These findings suggest that even moderately elevated ozone concentration in air can effect mineralisation and fixation processes of dichlorprop.

Solar concentrator with diffuser segments

NASA Astrophysics Data System (ADS)

Esparza, Diego; Moreno, Ivan

2011-08-01

Solar energy systems use concentrating optics with photovoltaic cells for optimizing the performance. Advanced concentrators are designed to maximize both the light collection and the spatial uniformity of radiation. This is important because irradiance uniformity is critical for all types of photovoltaic cells. This is difficult to achieve with traditional concentrators, which are built with polished optical surfaces. In this work we propose a new concept of solar concentrator which uses small diffuser segments in key points to increase the irradiation uniformity. We experimentally demonstrate this new concept by analyzing the effects on both efficiency and irradiance uniformity due to the incorporation of scattering ribbons in a compound parabolic concentrator.

The Affinity of D2-Like Dopamine Receptor Antagonists Determines the Time to Maximal Effect on Cocaine Self-Administration

PubMed Central

Tabet, Michael R.; Norman, Mantana K.; Fey, Brittney K.; Tsibulsky, Vladimir L.; Millard, Ronald W.

2011-01-01

Differences in the time to maximal effect (Tmax) of a series of dopamine receptor antagonists on the self-administration of cocaine are not consistent with their lipophilicity (octanol-water partition coefficients at pH 7.4) and expected rapid entry into the brain after intravenous injection. It was hypothesized that the Tmax reflects the time required for maximal occupancy of receptors, which would occur as equilibrium was approached. If so, the Tmax should be related to the affinity for the relevant receptor population. This hypothesis was tested using a series of nine antagonists having a 2500-fold range of Ki or Kd values for D2-like dopamine receptors. Rats self-administered cocaine at regular intervals and then were injected intravenously with a dose of antagonist, and the self-administration of cocaine was continued for 6 to 10 h. The level of cocaine at the time of every self-administration (satiety threshold) was calculated throughout the session. The satiety threshold was stable before the injection of antagonist and then increased approximately 3-fold over the baseline value at doses of antagonists selected to produce this approximately equivalent maximal magnitude of effect (maximum increase in the equiactive cocaine concentration, satiety threshold; Cmax). Despite the similar Cmax, the mean Tmax varied between 5 and 157 min across this series of antagonists. Furthermore, there was a strong and significant correlation between the in vivo Tmax values for each antagonist and the affinity for D2-like dopamine receptors measured in vitro. It is concluded that the cocaine self-administration paradigm offers a reliable and predictive bioassay for measuring the affinity of a competitive antagonist for D2-like dopamine receptors. PMID:21606176

Pharmacokinetic and pharmacodynamic analysis comparing diverse effects of detomidine, medetomidine, and dexmedetomidine in the horse: a population analysis.

PubMed

Grimsrud, K N; Ait-Oudhia, S; Durbin-Johnson, B P; Rocke, D M; Mama, K R; Rezende, M L; Stanley, S D; Jusko, W J

2015-02-01

The present study characterizes the pharmacokinetic (PK) and pharmacodynamic (PD) relationships of the α2-adrenergic receptor agonists detomidine (DET), medetomidine (MED) and dexmedetomidine (DEX) in parallel groups of horses from in vivo data after single bolus doses. Head height (HH), heart rate (HR), and blood glucose concentrations were measured over 6 h. Compartmental PK and minimal physiologically based PK (mPBPK) models were applied and incorporated into basic and extended indirect response models (IRM). Population PK/PD analysis was conducted using the Monolix software implementing the stochastic approximation expectation maximization algorithm. Marked reductions in HH and HR were found. The drug concentrations required to obtain inhibition at half-maximal effect (IC50 ) were approximately four times larger for DET than MED and DEX for both HH and HR. These effects were not gender dependent. Medetomidine had a greater influence on the increase in glucose concentration than DEX. The developed models demonstrate the use of mechanistic and mPBPK/PD models for the analysis of clinically obtainable in vivo data. © 2014 John Wiley & Sons Ltd.

Pharmacokinetic and pharmacodynamic analysis comparing diverse effects of detomidine, medetomidine, and dexmedetomidine in the horse: a population analysis

PubMed Central

Grimsrud, K. N.; Ait-Oudhia, S.; Durbin-Johnson, B. P.; Rocke, D. M.; Mama, K. R.; Rezende, M. L.; Stanley, S. D.; Jusko, W. J.

2014-01-01

The present study characterizes the pharmacokinetic (PK) and pharmacodynamic (PD) relationships of the α2-adrenergic receptor agonists detomidine (DET), medetomidine (MED) and dexmedetomidine (DEX) in parallel groups of horses from in vivo data after single bolus doses. Head height (HH), heart rate (HR), and blood glucose concentrations were measured over 6 h. Compartmental PK and minimal physiologically based PK (mPBPK) models were applied and incorporated into basic and extended indirect response models (IRM). Population PK/PD analysis was conducted using the Monolix software implementing the stochastic approximation expectation maximization algorithm. Marked reductions in HH and HR were found. The drug concentrations required to obtain inhibition at half-maximal effect (IC50) were approximately four times larger for DET than MED and DEX for both HH and HR. These effects were not gender dependent. Medetomidine had a greater influence on the increase in glucose concentration than DEX. The developed models demonstrate the use of mechanistic and mPBPK/PD models for the analysis of clinically obtainable in vivo data. PMID:25073816

Numerical investigation of the effect of particle concentration on particle measurement by digital holography

NASA Astrophysics Data System (ADS)

Zhao, Huafeng; Zhou, Binwu; Wu, Xuecheng; Wu, Yingchun; Gao, Xiang; Gréhan, Gérard; Cen, Kefa

2014-04-01

Digital holography plays a key role in particle field measurement, and appears to be a strong contender as the next-generation technology for diagnostics of 3D particle field. However, various recording parameters, such as the recording distance, the particle size, the wavelength, the size of the CCD chip, the pixel size and the particle concentration, will affect the results of the reconstruction, and may even determine the success or failure of a measurement. This paper presents a numerical investigation on the effect of particle concentration, the volume depth to evaluate the capability of digital holographic microscopy. Standard particles holograms with all known recording parameters are numerically generated by using a common procedure based on Lorenz-Mie scattering theory. Reconstruction of those holograms are then performed by a wavelet-transform based method. Results show that the reconstruction efficiency decreases quickly until particle concentration reaches 50×104 (mm-3), and decreases linearly with the increase of particle concentration from 50 × 104 (mm-3) to 860 × 104 (mm-3) in the same volume. The first half of the line waves larger than the second half. It also indicates that the increase of concentration leads the rise in average diameter error and z position error of particles. Besides, the volume depth also plays a key role in reconstruction.

Determinants of Maternal Sex Steroids During the First Half of Pregnancy

PubMed Central

Toriola, Adetunji T; Vääräsmäki, Marja; Lehtinen, Matti; Zeleniuch-Jacquotte, Anne; Lundin, Eva; Rodgers, Kenneth-Gary; Lakso, Hans-Ake; Chen, Tianhui; Schock, Helena; Hallmans, Goran; Pukkala, Eero; Toniolo, Paolo; Grankvist, Kjell; Surcel, Helja-Marja; Lukanova, Annekatrin

2011-01-01

Objective To examine the associations of maternal and child characteristics with early pregnancy maternal concentrations of testosterone, androstenedione, progesterone, 17-hydroxyprogesterone and estradiol. Methods We analyzed these hormones among 1,343 women with singleton pregnancies who donated serum samples to the Finnish Maternity Cohort from 1986 to 2006 during the first half of pregnancy (median, 11 weeks). The associations of maternal and child characteristics with hormone concentrations were investigated by correlation and multivariable regression. Results Women above age 30 had lower androgen and estradiol but higher progesterone concentrations than women below that age. Multiparous women had 14% lower testosterone, 11% lower androstenedione and 17-hydroxyprogesterone, 9% lower progesterone, and 16% lower estradiol concentrations compared to nulliparous women (all P<.05). Smoking mothers had 11%, 18%, and 8% higher testosterone, androstenedione, and 17-hydroxyprogesterone levels, respectively, but 10% lower progesterone compared to non-smoking women (all P<.05). Estradiol concentrations were 9% higher (P<0.05) among women with a female fetus compared to those with a male fetus. Conclusions Parity, smoking, and to a lesser extent maternal age and child gender are associated with sex steroid levels during the first half of a singleton pregnancy. The effects of smoking on the maternal hormonal environment and the possible long-term deleterious consequences on the fetus deserve further evaluation. PMID:22015870

Genetic variation in growth, carbon isotope discrimination, and foliar N concentration in Picea mariana: analyses from a half-diallel mating design using field-grown trees

Treesearch

Kurt H. Johnsen; Lawrence B. Flanagan; Dudley A. Huber; John E. Major

1999-01-01

The authors performed genetic analyses of growth, carbon isotope discrimination (?13C), and foliar N concentration using a half-diallel subset of a 7 × 7 complete diallel planted on three sites ranging in water availability. Trees were 22 years old. Heritabilities; general and...

Effects of spine flexion and erector spinae maximal force on vertical squat jump height: a computational simulation study.

PubMed

Blache, Yoann; Monteil, Karine

2015-03-01

The purpose of this study was to evaluate the single and combined effects of initial spine flexion and maximal isometric force of the erector spinae on maximal vertical jump height during maximal squat jumping. Seven initial flexions of the 'thorax-head-arm' segment (between 20.1° and 71.6°) and five maximal isometric forces of the erector spinae (between 5600 and 8600 N) were tested. Thus, 35 squat jumps were simulated using a 2D simulation model of the musculoskeletal system. Vertical jump height varied at most about 0.094 and 0.021 m when the initial flexion of the 'thorax-head-arm' segment and the maximal force of the erector spinae were, respectively, maximal. These results were explained for the most part by the variation of total muscle work. The latter was mainly influenced by the work produced by the erector spinae which increased at most about 57 and 110 J when the initial flexion of the 'thorax-head-arm' segment and the maximal force of the erector spinae were, respectively, maximal. It was concluded that the increase in the initial flexion of the 'thorax-head-arm' segment and in the maximal isometric force of the erector spinae enables an increase in maximal vertical jump height during maximal squat jumping.

Blood lactate clearance after maximal exercise depends on active recovery intensity.

PubMed

Devlin, J; Paton, B; Poole, L; Sun, W; Ferguson, C; Wilson, J; Kemi, O J

2014-06-01

High-intensity exercise is time-limited by onset of fatigue, marked by accumulation of blood lactate. This is accentuated at maximal, all-out exercise that rapidly accumulates high blood lactate. The optimal active recovery intensity for clearing lactate after such maximal, all-out exercise remains unknown. Thus, we studied the intensity-dependence of lactate clearance during active recovery after maximal exercise. We constructed a standardized maximal, all-out treadmill exercise protocol that predictably lead to voluntary exhaustion and blood lactate concentration>10 mM. Next, subjects ran series of all-out bouts that increased blood lactate concentration to 11.5±0.2 mM, followed by recovery exercises ranging 0% (passive)-100% of the lactate threshold. Repeated measurements showed faster lactate clearance during active versus passive recovery (P<0.01), and that active recovery at 60-100% of lactate threshold was more efficient for lactate clearance than lower intensity recovery (P<0.05). Active recovery at 80% of lactate threshold had the highest rate of and shortest time constant for lactate clearance (P<0.05), whereas the response during the other intensities was graded (100%=60%>40%>passive recovery, P<0.05). Active recovery after maximal all-out exercise clears accumulated blood lactate faster than passive recovery in an intensity-dependent manner, with maximum clearance occurring at active recovery of 80% of lactate threshold.

Effect of sonic driving on maximal aerobic performance.

PubMed

Brilla, L.R.; Hatcher, Stefanie

2000-07-01

The study purpose was to evaluate antecedent binaural stimulation (ABS) on maximal aerobic physical performance. Twenty-two healthy, physically active subjects, 21-34 years, randomly received one of two preparations for each session: 15 min of quiet (BLANK) or percussive sonic driving at 200+ beats per minute (bpm) using a recorded compact disc (FSS, Mill Valley, CA) with headphones (ABS). Baseline HR, blood pressure (BP), and breathing frequency (f(br)) were obtained. During each condition, HR and f(br) were recorded at 3-min intervals. The graded maximal treadmill testing was administered immediately postpreparation session on separate days, with at least 48 h rest between sessions. There were significant differences in the antecedent period means between the two conditions, ABS (HR: 70.2 +/- 10.7 bpm; f(br): 18.5 +/- 3.3 br min(-1); BP: 134.5/87.9 +/- 13.6/9.2 mm Hg) and BLANK (HR: 64.6 +/- 7.9; f(br): 14.3 +/- 2.9; BP: 126.7/80.3 +/- 12.1/8.6). Differences were noted for each 3-min interval and pre- postantecedent period. The maximal graded exercise test (GXT) results showed that there was a small but significant (P < 0.05), increase in maximal VO(2) in the ABS (49.8 +/- 6.8 ml. kg(-1). min(-1)) vs. BLANK (46.7 +/- 8.7) conditions. Related to that finding was a slight increase (0.5 min) in time to exhaustion (P < 0.05). There were no significant differences in HR or RPE (P > 0.05). There may be a latency to ABS related to entrainment or imagery-enhanced warm-up. Am. J. Hum. Biol. 12:558-565, 2000. Copyright 2000 Wiley-Liss, Inc.

Alpha-ketoisocaproate is not a true substrate for ATP production by pancreatic beta-cell mitochondria.

PubMed

Lembert, N; Idahl, L A

1998-03-01

The ability of alpha-ketoisocaproate (KIC) to induce ATP production in isolated mitochondria from pancreatic beta-cells was examined with a bioluminometric method. There was no ATP production from KIC when tested alone or in combination with malate (1 mmol/l), nor did DL-beta-hydroxybutyrate induce mitochondrial ATP production, whereas palmitoyl-carnitine and pyruvate were efficient stimulators of mitochondrial ATP production in the presence of an equimolar concentration of malate. However, KIC stimulated the mitochondrial ATP production when tested in combination with glutamate (10 mmol/l). The concentration necessary to obtain half-maximal stimulation was approximately 50 micromol/l KIC, and maximal activity, comparable to that obtained with fatty acids, was reached at 1 mmol/l KIC. Higher KIC concentrations inhibited the mitochondrial ATP production, whereas a plateau was attained at 1 mmol/l KIC in the presence of glutamine. Ca2+ stimulated the maximal mitochondrial ATP production induced by KIC. Maximal stimulation was obtained with 300 nmol/l Ca2+ in the presence of 0.3 mmol/l KIC. Ca2+ reduced the concentration of KIC necessary for half-maximal stimulation to <30 micromol/l. Leucine stimulated the mitochondrial ATP production in the presence of glutamate to the same extent as KIC. Half-maximal stimulation was observed with 2 mmol/l leucine. There were no additive effects on mitochondrial ATP production when KIC and leucine were tested in combination. The results demonstrate that KIC by itself is not a mitochondrial substrate for ATP production. KIC must transaminate with glutamate or glutamine to yield alpha-ketoglutarate and leucine. Since leucine allosterically activates glutamate dehydrogenase, which also produces alpha-ketoglutarate, the insulinogenic effect of KIC may in part be due to the intramitochondrial generation of alpha-ketoglutarate. Since KIC-induced ATP production reaches a plateau already at micromolar concentrations (i.e., far below the

Effects of maximal atorvastatin and rosuvastatin treatment on markers of glucose homeostasis and inflammation

USDA-ARS?s Scientific Manuscript database

Recent studies show that statin therapy, while effective at lowering the risk of cardiovascular disease (CVD), may be associated with an increased risk of diabetes. To test the effects of maximal dosages of rosuvastatin and atorvastatin (80mg/day and 40mg/day, respectively) we obtained frozen serum ...

Matching relations for optimal entanglement concentration and purification

PubMed Central

Kong, Fan-Zhen; Xia, Hui-Zhi; Yang, Ming; Yang, Qing; Cao, Zhuo-Liang

2016-01-01

The bilateral controlled NOT (CNOT) operation plays a key role in standard entanglement purification process, but the CNOT operation may not be the optimal joint operation in the sense that the output entanglement is maximized. In this paper, the CNOT operations in both the Schmidt-projection based entanglement concentration and the entanglement purification schemes are replaced with a general joint unitary operation, and the optimal matching relations between the entangling power of the joint unitary operation and the non-maximal entangled channel are found for optimizing the entanglement in- crement or the output entanglement. The result is somewhat counter-intuitive for entanglement concentration. The output entanglement is maximized when the entangling power of the joint unitary operation and the quantum channel satisfy certain relation. There exist a variety of joint operations with non-maximal entangling power that can induce a maximal output entanglement, which will greatly broaden the set of the potential joint operations in entanglement concentration. In addition, the entanglement increment in purification process is maximized only by the joint unitary operations (including CNOT) with maximal entangling power. PMID:27189800

Sex-Specific Impact of Ischemic Preconditioning on Tissue Oxygenation and Maximal Concentric Force.

PubMed

Paradis-Deschênes, Pénélope; Joanisse, Denis R; Billaut, François

2016-01-01

Prior peripheral hypoxia induced via remote ischemic preconditioning (IPC) can improve physical performance in male athletes through improved O 2 delivery and utilization. Since females may have an innate protective mechanism against ischemia-reperfusion injury, and since muscle metabolism during contraction differs between sexes, it is relevant to examine the impact of sex in response to IPC to determine whether it is also ergogenic in females. In a randomized, crossover, single-blind study, we investigated muscle performance, hemodynamic and O 2 uptake in strength-trained males ( n = 9) and females ( n = 8) performing five sets of 5 maximum voluntary knee extensions on an isokinetic dynamometer, preceded by either IPC (3 × 5-min ischemia/5-min reperfusion cycles at 200 mmHg) or SHAM (20 mmHg). Changes in deoxy-hemoglobin (Δ[HHb], expressed in percentage of arterial occlusion and considered an index of O 2 extraction), and total hemoglobin (Δ[THb]) concentrations of the vastus lateralis muscle were continuously monitored by near-infrared spectroscopy. The metabolic efficiency of the contractions was calculated as the average force/Δ[HHb] avg ratio. Cohen's effect sizes (ES) ± 90% confidence limits were used to estimate IPC-induced changes and sex differences. IPC increased total muscular force in males only (13.0%, ES 0.64, 0.37;0.90), and this change was greater than in females (10.4% difference, ES 0.40, 0.10;0.70). Percent force decrement was only attenuated in females (-19.8%, ES -0.38, -0.77;0.01), which was clearly different than males (sex difference: ES 0.45, -0.16;1.07). IPC also induced different changes between sexes for average muscle O 2 uptake in set 2 (males: 6.4% vs. females: -16.7%, ES 0.21, -0.18;0.60), set 3 (males: 7.0% vs. females: -44.4%, ES 0.56, -0.17;1.29), set 4 (males: 9.1% vs. females: -40.2%, ES 0.51, -0.10;1.13), and set 5 (males: 10.2% vs. females: -40.4%, ES 0.52, -0.04;1.09). However, metabolic efficiency was not meaningfully

Systemic inflammatory responses to maximal versus submaximal lengthening contractions of the elbow flexors.

PubMed

Peake, Jonathan M; Nosaka, Kazunori; Muthalib, Makii; Suzuki, Katsuhiko

2006-01-01

We compared changes in markers of muscle damage and systemic inflammation after submaximal and maximal lengthening muscle contractions of the elbow flexors. Using a cross-over design, 10 healthy young men not involved in resistance training completed a submaximal trial (10 sets of 60 lengthening contractions at 10% maximum isometric strength, 1 min rest between sets), followed by a maximal trial (10 sets of three lengthening contractions at 100% maximum isometric strength, 3 min rest between sets). Lengthening contractions were performed on an isokinetic dynamometer. Opposite arms were used for the submaximal and maximal trials, and the trials were separated by a minimum of two weeks. Blood was sampled before, immediately after, 1 h, 3 h, and 1-4 d after each trial. Total leukocyte and neutrophil numbers, and the serum concentration of soluble tumor necrosis factor-alpha receptor 1 were elevated after both trials (P < 0.01), but there were no differences between the trials. Serum IL-6 concentration was elevated 3 h after the submaximal contractions (P < 0.01). The concentrations of serum tumor necrosis factor-alpha, IL-1 receptor antagonist, IL-10, granulocyte-colony stimulating factor and plasma C-reactive protein remained unchanged following both trials. Maximum isometric strength and range of motion decreased significantly (P < 0.001) after both trials, and were lower from 1-4 days after the maximal contractions compared to the submaximal contractions. Plasma myoglobin concentration and creatine kinase activity, muscle soreness and upper arm circumference all increased after both trials (P < 0.01), but were not significantly different between the trials. Therefore, there were no differences in markers of systemic inflammation, despite evidence of greater muscle damage following maximal versus submaximal lengthening contractions of the elbow flexors.

Cardiovascular consequences of bed rest: effect on maximal oxygen uptake

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1997-01-01

Maximal oxygen uptake (VO2max) is reduced in healthy individuals confined to bed rest, suggesting it is independent of any disease state. The magnitude of reduction in VO2max is dependent on duration of bed rest and the initial level of aerobic fitness (VO2max), but it appears to be independent of age or gender. Bed rest induces an elevated maximal heart rate which, in turn, is associated with decreased cardiac vagal tone, increased sympathetic catecholamine secretion, and greater cardiac beta-receptor sensitivity. Despite the elevation in heart rate, VO2max is reduced primarily from decreased maximal stroke volume and cardiac output. An elevated ejection fraction during exercise following bed rest suggests that the lower stroke volume is not caused by ventricular dysfunction but is primarily the result of decreased venous return associated with lower circulating blood volume, reduced central venous pressure, and higher venous compliance in the lower extremities. VO2max, stroke volume, and cardiac output are further compromised by exercise in the upright posture. The contribution of hypovolemia to reduced cardiac output during exercise following bed rest is supported by the close relationship between the relative magnitude (% delta) and time course of change in blood volume and VO2max during bed rest, and also by the fact that retention of plasma volume is associated with maintenance of VO2max after bed rest. Arteriovenous oxygen difference during maximal exercise is not altered by bed rest, suggesting that peripheral mechanisms may not contribute significantly to the decreased VO2max. However reduction in baseline and maximal muscle blood flow, red blood cell volume, and capillarization in working muscles represent peripheral mechanisms that may contribute to limited oxygen delivery and, subsequently, lowered VO2max. Thus, alterations in cardiac and vascular functions induced by prolonged confinement to bed rest contribute to diminution of maximal oxygen uptake

A half-metallic half-Heusler alloy having the largest atomic-like magnetic moment at optimized lattice constant

DOE PAGES

Zhang, R. L.; Damewood, L.; Fong, C. Y.; ...

2016-11-02

For half-Heusler alloys, the general formula is XYZ, where X can be a transition or alkali metal element, Y is another transition metal element, typically Mn or Cr, and Z is a group IV element or a pnicitide. The atomic arrangements within a unit-cell show three configurations. Before this study, most of the predictions of half-metallic properties of half-Heusler alloys at the lattice constants differing from their optimized lattice constant. Based on the electropositivity of X and electronegativity of Z for half-Heusler alloys, we found that one of the configurations of LiCrS exhibits half-metallic properties at its optimized lattice constantmore » of 5.803Å, and has the maximum atomic-like magnetic moment of 5μ B. In conclusion, the challenges of its growth and the effects of the spin-orbit effect in this alloy will be discussed.« less

Anxiety responses to maximal exercise testing.

PubMed Central

O'Connor, P J; Petruzzello, S J; Kubitz, K A; Robinson, T L

1995-01-01

The influence of maximal exercise testing on state anxiety was examined in three separate studies. Highly trained male distance runners (Study 1, n = 12) as well as college students with average (Study 2, n = 16) and below average (Study 3, n = 32) physical fitness levels completed graded maximal exercise tests. This last group was also randomly assigned to either a control or an 8 week training programme in order to determine the effect of increased fitness on the psychological responses to maximal exercise testing. Physical fitness was determined by the measurement of maximal oxygen uptake. State anxiety (State-Trait Anxiety Inventory) was assessed before and from 2-15 min following exercise. It was found that the state anxiety responses to maximal exercise testing were not influenced by re-testing or by 8 weeks of endurance training. Across the three study groups, the anxiety response was variable during the first 5 min following exercise testing; increases, decreases and no changes in anxiety were observed when compared to pre-exercise levels. The anxiety response to maximal exercise appeared to be dependent on the pre-exercise anxiety levels as well as the timing of the post-exercise assessments. It is concluded that maximal exercise testing can be associated with negative mood shifts during the first 5 min after exercise; however, this response is transitory and followed by positive mood shifts 10-15 min following such tests. PMID:7551769

The acute effects of moderately loaded concentric-only quarter squats on vertical jump performance.

PubMed

Crum, Aaron J; Kawamori, Naoki; Stone, Michael H; Haff, G Gregory

2012-04-01

Limited research exists examining the effect of moderately loaded conditioning activities that are employed as part of a strength-power potentiating complex (SPPC). Additionally, no studies to date have explored the effects of using a concentric-only quarter back squat protocol as part of an SPPC. Therefore, the purpose of this study was to examine the effects of a moderately loaded (50-65% of 1RM) concentric-only quarter back squat protocol on the occurrence of potentiation effects at various time points. Twenty men who could quarter back squat a minimum of 2.4 times their body mass (3.7 ± 0.7 kg·per body mass) participated in this investigation. All subjects participated in 3 conditions: control (CT), a 50% of 1RM trial (50POT), and a 65% of 1RM trial (65POT). One minute before each condition, a maximal countermovement vertical jump (CMJ) was performed. One minute later, the subject performed 1 of 3 conditions: CT condition, 50POT, or 65POT, followed by vertical jumps at 0.5, 3, 5, 10, and 15 minutes after conditioning activity. A force plate was used to quantify displacement, peak power output, peak force, and the rate of force development for each CMJ. There were no significant differences (p > 0.05) in any of the performance measures quantified during the CMJ trials when comparing the CT, 50POT, and 65POT treatment conditions. However, 48% of the subjects demonstrated some degree of potentiation at the 30 seconds after completing the 65POT trial, but this percent increase was not statistically significant. From a practical perspective, if the goal of the SPPC is to create a maximization of the potentiation effect, moderately loaded activities may not be the best alternative.

Preservation of bovine hide using less salt with low concentration of antiseptic, part I: effectiveness of developed formulations

USDA-ARS?s Scientific Manuscript database

Bovine raw hides are commercially cured either with high salt concentration of about half the weight of actual hide or 95% saturated brine solution. This conventional technique is very popular due to the availability of common salt (sodium chloride) and its cost effective procedure but it generates ...

The Effects of Multiple-Joint Isokinetic Resistance Training on Maximal Isokinetic and Dynamic Muscle Strength and Local Muscular Endurance.

PubMed

Ratamess, Nicholas A; Beller, Noah A; Gonzalez, Adam M; Spatz, Gregory E; Hoffman, Jay R; Ross, Ryan E; Faigenbaum, Avery D; Kang, Jie

2016-03-01

The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects' peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s(-1) [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey's post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key pointsMultiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women.Multiple-joint isokinetic resistance training increased 1RM strength in the bench press (by

The Effects of Multiple-Joint Isokinetic Resistance Training on Maximal Isokinetic and Dynamic Muscle Strength and Local Muscular Endurance

PubMed Central

Ratamess, Nicholas A.; Beller, Noah A.; Gonzalez, Adam M.; Spatz, Gregory E.; Hoffman, Jay R.; Ross, Ryan E.; Faigenbaum, Avery D.; Kang, Jie

2016-01-01

The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects’ peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s-1 [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey’s post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key points Multiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women. Multiple-joint isokinetic resistance training increased 1RM strength in the bench press

Stanol esters as a component of maximal dietary therapy in the National Cholesterol Education Program Adult Treatment Panel III report.

PubMed

Grundy, Scott M

2005-07-04

Use of plant stanols/sterols in forms that are sufficiently bioavailable for therapeutic effect should be a key element of maximal dietary therapy. This principle was recognized by National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) and has been amply confirmed by experimental studies in humans. Since the introduction of statins, dietary therapy for control of elevated low-density lipoprotein (LDL) cholesterol levels has received less attention. The time has come, however, to reassert the importance of maximal dietary therapy as a cost-effective means for treatment of elevated LDL concentrations and for lifetime prevention of coronary heart disease.

Radiocesium concentrations in the bark, sapwood and heartwood of three tree species collected at Fukushima forests half a year after the Fukushima Dai-ichi nuclear accident.

PubMed

Kuroda, Katsushi; Kagawa, Akira; Tonosaki, Mario

2013-08-01

Radiocesium ((134)Cs and (137)Cs) distribution in tree stems of Japanese cedar (aged 40-56 y), red pine (42 y), and oak (42 y) grown in Fukushima Prefecture were investigated approximately half a year after the Fukushima Dai-ichi nuclear accident. Japanese cedar, red pine, and oak were selected from five sites, one site, and one site, respectively. Three trees at each site were felled, and bark, sapwood (the outer layer of wood in the stem), and heartwood (the inner layer of wood in the stem) separately collected to study radiocesium concentrations measured by gamma-ray spectrometry. The radiocesium deposition densities at the five sites were within the range of 16-1020 kBq m(-2). The radiocesium was distributed in bark, sapwood, and heartwood in three tree species, indicating that very rapid translocation of radiocesium into the wood. The concentration of radiocesium in oak (deciduous angiosperm) bark was higher than that in the bark of Japanese cedar and red pine (evergreen gymnosperms). Both sapwood and heartwood contained radiocesium, and the values were much lower than that in the bark samples. The results suggest that radiocesium contamination half a year after the accident was mainly attributable to the direct radioactive deposition. The radiocesium concentrations in the Japanese cedar samples taken from five sites rose with the density of radiocesium accumulation on the ground surface. To predict the future dynamics of radiocesium in tree stems, the present results taken half a year after the accident are important, and continuous study of radiocesium in tree stems is necessary. Copyright © 2013 Elsevier Ltd. All rights reserved.

Half-and-Half Palatoplasty.

PubMed

Han, Hyun Ho; Kang, In Sook; Rhie, Jong Won

2014-08-01

A 14-month-old child was diagnosed with a Veau Class II cleft palate. Von Langenbeck palatoplasty was performed for the right palate, and V-Y pushback palatoplasty was performed for the left palate. The child did not have a special problem during the surgery, and the authors were able to elongate the cleft by 10 mm. Contrary to preoperative concerns regarding the hybrid use of palatoplasties, the uvula and midline incisions remained balanced in the middle. The authors named this combination method "half-and-half palatoplasty" and plan to conduct a long-term follow up study as a potential solution that minimizes the complications of palatoplasty.

Half-and-Half Palatoplasty

PubMed Central

Han, Hyun Ho; Kang, In Sook

2014-01-01

A 14-month-old child was diagnosed with a Veau Class II cleft palate. Von Langenbeck palatoplasty was performed for the right palate, and V-Y pushback palatoplasty was performed for the left palate. The child did not have a special problem during the surgery, and the authors were able to elongate the cleft by 10 mm. Contrary to preoperative concerns regarding the hybrid use of palatoplasties, the uvula and midline incisions remained balanced in the middle. The authors named this combination method "half-and-half palatoplasty" and plan to conduct a long-term follow up study as a potential solution that minimizes the complications of palatoplasty. PMID:28913201

Effective Educational Videos: Principles and Guidelines for Maximizing Student Learning from Video Content

ERIC Educational Resources Information Center

Brame, Cynthia J.

2016-01-01

Educational videos have become an important part of higher education, providing an important content-delivery tool in many flipped, blended, and online classes. Effective use of video as an educational tool is enhanced when instructors consider three elements: how to manage cognitive load of the video; how to maximize student engagement with the…

Concentric Split Flow Filter

NASA Technical Reports Server (NTRS)

Stapleton, Thomas J. (Inventor)

2015-01-01

A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

Effects of strong interactions in a half-metallic magnet: A determinant quantum Monte Carlo study

DOE PAGES

Jiang, M.; Pickett, W. E.; Scalettar, R. T.

2013-04-03

Understanding the effects of electron-electron interactions in half-metallic magnets (HMs), which have band structures with one gapped spin channel and one metallic channel, poses fundamental theoretical issues as well as having importance for their potential applications. Here we use determinant quantum Monte Carlo to study the impacts of an on-site Hubbard interaction U, finite temperature, and an external (Zeeman) magnetic field on a bilayer tight-binding model which is a half-metal in the absence of interactions, by calculating the spectral density, conductivity, spin polarization of carriers, and local magnetic properties. We quantify the effect of U on the degree of thermalmore » depolarization, and follow relative band shifts and monitor when significant gap states appear, each of which can degrade the HM character. For this model, Zeeman coupling induces, at fixed particle number, two successive transitions: compensated half-metal with spin-down band gap → metallic ferromagnet → saturated ferromagnetic insulator. However, over much of the more relevant parameter regime, the half-metallic properties are rather robust to U.« less

Nuclear isospin effect on α-decay half-lives

NASA Astrophysics Data System (ADS)

Akrawy, Dashty T.; Hassanabadi, H.; Hosseini, S. S.; Santhosh, K. P.

2018-07-01

The α-decay half-lives for the even-even, even-odd, odd-even and odd-odd of 356 nuclei in the range 52 ≤Zp ≤ 118 have been studied within the analytical formula of Royer and also within the modified analytical formula of Royer. We calculated the new coefficient of the Royer by fitting 356 isotopes. Also, we considered the Denisov and Khudenko formula and obtained the new coefficient for the modified Denisov and Khudenko formula. We calculated the standard deviation and the average deviation. Analytical results are compared with the experimental data. The results are in better agreement with the experimental data when the effect of the isospin considered for the parent nuclei.

Consideration on the Long Ecological Half-Life Component of (137)Cs in Demersal Fish Based on Field Observation Results Obtained after the Fukushima Accident.

PubMed

Tagami, Keiko; Uchida, Shigeo

2016-02-16

Radiocesium concentrations in most marine fish collected off the coast of Fukushima and surrounding prefectures have decreased with time, and four years after the Fukushima Daiichi Nuclear Power Plant accident occurred, radiocesium concentrations have generally fallen below the detectable level (ca. < 10 Bq kg(-1)-raw). Only in some demersal fish species have detectable concentration levels still been found, and even these species have showed slow radiocesium decreases. The food web was considered as the major factor causing this phenomenon; however, slow elimination rates of radiocesium from these fish species also could be the cause. The latter effect was examined by considering that the (137)Cs concentration decreasing trend in fish could be fit with a set of three exponentially decreasing components; that is, having short, intermediate, and long biological half-lives. The long ecological half-life component was calculated using a 400-1500 d period of monitoring results for Japanese rockfish (Sebastes cheni) and compared with previous reported laboratory results for biological half-life. The obtained ecological half-lives ranged from 274-365 d, and these values agreed with the biological half-life of this fish species. This result implied that the long biological half-lives of radiocesium in some demersal fish species made their radiocesium contamination periods longer.

Sex-Specific Impact of Ischemic Preconditioning on Tissue Oxygenation and Maximal Concentric Force

PubMed Central

Paradis-Deschênes, Pénélope; Joanisse, Denis R.; Billaut, François

2017-01-01

Prior peripheral hypoxia induced via remote ischemic preconditioning (IPC) can improve physical performance in male athletes through improved O2 delivery and utilization. Since females may have an innate protective mechanism against ischemia-reperfusion injury, and since muscle metabolism during contraction differs between sexes, it is relevant to examine the impact of sex in response to IPC to determine whether it is also ergogenic in females. In a randomized, crossover, single-blind study, we investigated muscle performance, hemodynamic and O2 uptake in strength-trained males (n = 9) and females (n = 8) performing five sets of 5 maximum voluntary knee extensions on an isokinetic dynamometer, preceded by either IPC (3 × 5-min ischemia/5-min reperfusion cycles at 200 mmHg) or SHAM (20 mmHg). Changes in deoxy-hemoglobin (Δ[HHb], expressed in percentage of arterial occlusion and considered an index of O2 extraction), and total hemoglobin (Δ[THb]) concentrations of the vastus lateralis muscle were continuously monitored by near-infrared spectroscopy. The metabolic efficiency of the contractions was calculated as the average force/Δ[HHb]avg ratio. Cohen's effect sizes (ES) ± 90% confidence limits were used to estimate IPC-induced changes and sex differences. IPC increased total muscular force in males only (13.0%, ES 0.64, 0.37;0.90), and this change was greater than in females (10.4% difference, ES 0.40, 0.10;0.70). Percent force decrement was only attenuated in females (−19.8%, ES −0.38, −0.77;0.01), which was clearly different than males (sex difference: ES 0.45, −0.16;1.07). IPC also induced different changes between sexes for average muscle O2 uptake in set 2 (males: 6.4% vs. females: −16.7%, ES 0.21, −0.18;0.60), set 3 (males: 7.0% vs. females: −44.4%, ES 0.56, −0.17;1.29), set 4 (males: 9.1% vs. females: −40.2%, ES 0.51, −0.10;1.13), and set 5 (males: 10.2% vs. females: −40.4%, ES 0.52, −0.04;1.09). However, metabolic efficiency was

Effects of intravenous temazepam. II. A study of the long-term reproducibility of pharmacokinetics, pharmacodynamics, and concentration-effect parameters.

PubMed

van Steveninck, A L; Schoemaker, H C; den Hartigh, J; Pieters, M S; Breimer, D D; Cohen, A F

1994-05-01

To evaluate the long-term reproducibility of pharmacokinetic, pharmacodynamic, and concentration-effect parameters after intravenous administration of temazepam. Nine healthy volunteers were studied. Temazepam, 0.4 mg/kg, was infused intravenously for 30 minutes on two occasions 6 months apart. Venous plasma concentrations of temazepam were measured by HPLC in samples obtained between 0 and 24 hours. Pharmacodynamic effects were evaluated up to 8 hours for saccadic peak velocity and electroencephalogram (EEG) beta amplitudes. Subjects' state and trait anxiety were assessed by use of the Spielberger anxiety inventory. Significant correlations between occasions were found for area under the plasma concentration-time curve (AUC) values (r = 0.91; p < 0.01) but not for maximum concentration and half-life. Significant correlations were also found for area under the effect-time curve (AUEC) values of peak velocity (r = 0.88; p < 0.01) but not for peak velocity (r = 0.48; p > 0.05). Significant differences between the slopes of concentration effect plots on different occasions were observed in two subjects for EEG beta and in three subjects for peak velocity, with one subject showing a similar change for both parameters. Trait anxiety scores were higher on the first occasion (33 +/- 7) than on the second occasion (29 +/- 7; p < 0.01). A negative correlation was found between trait anxiety scores and the slopes of concentration-effect plots for peak velocity (r = -0.63; p < 0.01). For AUC and AUEC values the results indicate a reasonable long-term reproducibility of differences between subjects in the pharmacokinetics and pharmacodynamics of temazepam. However, there were limitations to the predictive value of derived concentration-effect parameters.

Strategic Placement of Treatments (SPOTS): Maximizing the Effectiveness of Fuel and Vegetation Treatments on Problem Fire Behavior and Effects

Treesearch

Diane M. Gercke; Susan A. Stewart

2006-01-01

In 2005, eight U.S. Forest Service and Bureau of Land Management interdisciplinary teams participated in a test of strategic placement of treatments (SPOTS) techniques to maximize the effectiveness of fuel treatments in reducing problem fire behavior, adverse fire effects, and suppression costs. This interagency approach to standardizing the assessment of risks and...

Effects of maximal doses of atorvastatin versus rosuvastatin on small dense low-density lipoprotein cholesterol levels

USDA-ARS?s Scientific Manuscript database

Maximal doses of atorvastatin and rosuvastatin are highly effective in lowering low-density lipoprotein (LDL) cholesterol and triglyceride levels; however, rosuvastatin has been shown to be significantly more effective than atorvastatin in lowering LDL cholesterol and in increasing high-density lipo...

Effect of L-ornithine hydrochloride ingestion on intermittent maximal anaerobic cycle ergometer performance and fatigue recovery after exercise.

PubMed

Demura, Shinichi; Morishita, Koji; Yamada, Takayoshi; Yamaji, Shunsuke; Komatsu, Miho

2011-11-01

L-Ornithine plays an important role in ammonia metabolism via the urea cycle. This study aimed to examine the effect of L-ornithine hydrochloride ingestion on ammonia metabolism and performance after intermittent maximal anaerobic cycle ergometer exercise. Ten healthy young adults (age, 23.8 ± 3.9 year; height, 172.3 ± 5.5 cm; body mass, 67.7 ± 6.1 kg) with regular training experience ingested L-ornithine hydrochloride (0.1 g/kg, body mass) or placebo after 30 s of maximal cycling exercise. Five sets of the same maximal cycling exercise were conducted 60 min after ingestion, and maximal cycling exercise was conducted after a 15 min rest. The intensity of cycling exercise was based on each subject's body mass (0.74 N kg(-1)). Work volume (watt), peak rpm (rpm) before and after intermittent maximal ergometer exercise and the following serum parameters were measured before ingestion, immediately after exercise and 15 min after exercise: ornithine, ammonia, urea, lactic acid and glutamate. Peak rpm was significantly greater with L-ornithine hydrochloride ingestion than with placebo ingestion. Serum ornithine level was significantly greater with L-ornithine hydrochloride ingestion than with placebo ingestion immediately and 15 min after intermittent maximal cycle ergometer exercise. In conclusion, although maximal anaerobic performance may be improved by L-ornithine hydrochloride ingestion before intermittent maximal anaerobic cycle ergometer exercise, the above may not depend on increase of ammonia metabolism with L-ornithine hydrochloride.

Inhibitory Effect of Apigenin on Losartan Metabolism and CYP2C9 Activity in vitro.

PubMed

Wang, Zhe; Gong, Yun; Zeng, Da-Li; Chen, Lian-Guo; Lin, Gao-Tong; Huang, Cheng-Ke; Sun, Wei; Chen, Meng-Chun; Hu, Guo-Xin; Chen, Rui-Jie

2016-01-01

CYP2C9 is one of the most important phase I drug-metabolizing enzymes in liver. The objective of this work was to investigate the effects of apigenin on the metabolism of losartan and human CYP2C9 and rat CYP2C11 activity in vitro. Different concentrations of apigenin were added to a 100 mmol/l Tris-HCl reaction mixture containing 2 pmol/ml recombinant human CYP2C9.1, 0.25 mg/ml human liver microsomes or 0.5 mg/ml rat liver microsomes to determine the half maximal inhibition or a half-maximal inhibitory concentration (IC50) on the metabolism of losartan. In addition, diclofenac used as CYP2C9 substrate was performed to determine the effects of apigenin on CYP2C9. The results showed that apigenin has the inhibitory effect on the metabolism of losartan in vitro, the IC50 was 7.61, 4.10 and 11.07 μmol/l on recombinant CYP2C9 microsomes, human liver microsomes and rat liver microsomes, respectively. Meanwhile, apigenin's mode of action on human CYP2C9 activity was competitive for the substrate diclofenac. In contrast to its potent inhibition of CYP2C9 in humans (9.51 μmol/l), apigenin had lesser effects on CYP2C11 in rat (IC50 = 15.51 μmol/l). The observations imply that apigenin has the inhibitory effect on the metabolism of losartan and CYP2C9 activity in vitro. More attention should be paid as to when losartan should be administrated combined with apigenin. © 2016 S. Karger AG, Basel.

Effect of increasing bromide concentration on toxicity in treated drinking water.

PubMed

Sawade, Emma; Fabris, Rolando; Humpage, Andrew; Drikas, Mary

2016-04-01

Research is increasingly indicating the potential chronic health effects of brominated disinfection by-products (DBPs). This is likely to increase with elevated bromide concentrations resulting from the impacts of climate change, projected to include extended periods of drought and the sudden onset of water quality changes. This will demand more rigorous monitoring throughout distribution systems and improved water quality management at water treatment plants (WTPs). In this work the impact of increased bromide concentration on formation of DBPs following conventional treatment and chlorination was assessed for two water sources. Bioanalytical tests were utilised to determine cytotoxicity of the water post disinfection. Coagulation was shown to significantly reduce the cytotoxicity of the water, indicating that removal of natural organic matter DBP precursors continues to be an important factor in drinking water treatment. Most toxic species appear to form within the first half hour following disinfectant addition. Increasing bromide concentration across the two waters was shown to increase the formation of trihalomethanes and shifted the haloacetic acid species distribution from chlorinated to those with greater bromine substitution. This correlated with increasing cytotoxicity. This work demonstrates the challenges faced by WTPs and the possible effects increasing levels of bromide in source waters could have on public health.

Rivaroxaban and apixaban in orthopaedics: is there a difference in their plasma concentrations and anticoagulant effects?

PubMed Central

Freyburger, Geneviève; Macouillard, Gérard; Khennoufa, Karim; Labrouche, Sylvie; Molimard, Mathieu; Sztark, François

2015-01-01

The aim of this study was to improve knowledge of what happens in the coagulation of orthopaedic patients under rivaroxaban and apixaban, in order to finalize and cross-validate effective measurement methods and to provide arguments for helping to reference one or the other drug in our central pharmacy. One hundred and two patients undergoing total hip or knee replacement were included. Half of them received rivaroxaban and the other half received apixaban. Blood samples (n = 244 with each drug) were taken at Cmax preoperatively and twice a week, apart from the day of the patient's discharge, when Ctrough concentration was targeted. Routine coagulation parameters, and functional and liquid chromatography tandem mass spectrometry assays for measurement of circulating concentrations were studied. The LC-MS/MS assay and the functional assays carried out in patients under routine conditions were highly correlated, apart from low concentrations (<30 ng/ml), which were affected by the variable individual potential to inhibit the exogenous bovine Xa used in the functional assays. After 1 week of treatment, the drugs differed: Cmax and Ctrough were closer when apixaban was taken twice daily (83 ± 39 and 58 ± 17 ng/ml) than with rivaroxaban taken once a day (113 ± 67 and 13 ± 20 ng/ml). Rivaroxaban had a greater influence on routine coagulation tests and reduced the maximum thrombin concentration more efficiently, as assessed by the thrombin generation test. Although rivaroxaban and apixaban present apparently similar constant rates, they exhibit significant differences in their concentrations and anticoagulant effects when studied ex vivo in orthopedic patients. PMID:26258673

Male patients require higher optimal effect-site concentrations of propofol during i-gel insertion with dexmedetomidine 0.5 μg/kg.

PubMed

Choi, Jung Ju; Kim, Ji Young; Lee, Dongchul; Chang, Young Jin; Cho, Noo Ree; Kwak, Hyun Jeong

2016-03-22

The pharmacokinetics and pharmacodynamics of an anesthetic drug may be influenced by gender. The purpose of this study was to compare effect-site half maximal effective concentrations (EC50) of propofol in male and female patients during i-gel insertion with dexmedetomidine 0.5 μg/kg without muscle relaxants. Forty patients, aged 20-46 years of ASA physical status I or II, were allocated to one of two groups by gender (20 patients per group). After the infusion of dexmedetomidine 0.5 μg/kg over 2 min, anesthesia was induced with a pre-determined effect-site concentration of propofol by target controlled infusion. Effect-site EC50 values of propofol for successful i-gel insertion were determined using the modified Dixon's up-and-down method. Mean effect-site EC50 ± SD of propofol for successful i-gel insertion was significantly higher for men than women (5.46 ± 0.26 μg/ml vs. 3.82 ± 0.34 μg/ml, p < 0.01). The EC50 of propofol in men was approximately 40% higher than in women. Using isotonic regression with a bootstrapping approach, the estimated EC50 (95% confidence interval) of propofol was also higher in men [5.32 (4.45-6.20) μg/ml vs. 3.75 (3.05-4.43) μg/ml]. The estimated EC95 (95% confidence interval) of propofol in men and women were 5.93 (4.72-6.88) μg/ml and 4.52 (3.02-5.70) μg/ml, respectively. During i-gel insertion with dexmedetomidine 0.5 μg/kg without muscle relaxant, male patients had higher effect-site EC50 for propofol using Schnider's model. Based on the results of this study, patient gender should be considered when determining the optimal dose of propofol during supraglottic airway insertion. ClinicalTrials.gov identifier: NCT02268656. Registered August 26, 2014.

Concentration Addition, Independent Action and Generalized Concentration Addition Models for Mixture Effect Prediction of Sex Hormone Synthesis In Vitro

PubMed Central

Hadrup, Niels; Taxvig, Camilla; Pedersen, Mikael; Nellemann, Christine; Hass, Ulla; Vinggaard, Anne Marie

2013-01-01

Humans are concomitantly exposed to numerous chemicals. An infinite number of combinations and doses thereof can be imagined. For toxicological risk assessment the mathematical prediction of mixture effects, using knowledge on single chemicals, is therefore desirable. We investigated pros and cons of the concentration addition (CA), independent action (IA) and generalized concentration addition (GCA) models. First we measured effects of single chemicals and mixtures thereof on steroid synthesis in H295R cells. Then single chemical data were applied to the models; predictions of mixture effects were calculated and compared to the experimental mixture data. Mixture 1 contained environmental chemicals adjusted in ratio according to human exposure levels. Mixture 2 was a potency adjusted mixture containing five pesticides. Prediction of testosterone effects coincided with the experimental Mixture 1 data. In contrast, antagonism was observed for effects of Mixture 2 on this hormone. The mixtures contained chemicals exerting only limited maximal effects. This hampered prediction by the CA and IA models, whereas the GCA model could be used to predict a full dose response curve. Regarding effects on progesterone and estradiol, some chemicals were having stimulatory effects whereas others had inhibitory effects. The three models were not applicable in this situation and no predictions could be performed. Finally, the expected contributions of single chemicals to the mixture effects were calculated. Prochloraz was the predominant but not sole driver of the mixtures, suggesting that one chemical alone was not responsible for the mixture effects. In conclusion, the GCA model seemed to be superior to the CA and IA models for the prediction of testosterone effects. A situation with chemicals exerting opposing effects, for which the models could not be applied, was identified. In addition, the data indicate that in non-potency adjusted mixtures the effects cannot always be

Design, synthesis, and antimelanogenic effects of (2-substituted phenyl-1,3-dithiolan-4-yl)methanol derivatives

PubMed Central

Kim, Do Hyun; Kim, Su Jeong; Ullah, Sultan; Yun, Hwi Young; Chun, Pusoon; Moon, Hyung Ryong

2017-01-01

The authors designed and synthesized 17 (2-substituted phenyl-1,3-dithiolan-4-yl) methanol (PDTM) derivatives to find a new chemical scaffold, showing excellent tyrosinase-inhibitory activity. Their tyrosinase-inhibitory activities were evaluated against mushroom tyrosinase at 50 μM, and five of the PDTM derivatives (PDTM3, PDTM7–PDTM9, and PDTM13) were found to inhibit mushroom tyrosinase more than kojic acid or arbutin, the positive controls. Of seventeen PDTMs, PDTM3 (half-maximal inhibitory concentration 13.94±1.76 μM), with a 2,4-dihydroxyphenyl moiety, exhibited greatest inhibitory effects (kojic acid half-maximal inhibitory concentration 18.86±2.14 μM). Interestingly, PDTM compounds with no hydroxyl group, PDTM7–PDTM9, also had stronger inhibitory activities than kojic acid. In silico studies of interactions between tyrosinase and the five PDTMs suggested their binding affinities were closely related to their tyrosinase-inhibitory activities. Cell-based experiments performed using B16F10 mouse-skin melanoma cells showed that PDTM3 effectively inhibited melanogenesis and cellular tyrosinase activity. A cell-viability study conducted using B16F10 cells indicated that the antimelanogenic effect of PDTM3 was not attributable to its cytotoxicity. Kinetic studies showed PDTM3 competitively inhibited tyrosinase, indicating binding to the tyrosinase-active site. We found that PDTM3 with a new chemical scaffold could be a promising candidate for skin-whitening agents, and that the 1,3-dithiolane ring could be used as a chemical scaffold for potent tyrosinase inhibition. PMID:28352157

Effects of Hemopure on maximal oxygen uptake and endurance performance in healthy humans.

PubMed

Ashenden, M J; Schumacher, Y O; Sharpe, K; Varlet-Marie, E; Audran, M

2007-05-01

Haemoglobin-based oxygen carriers (HBOCs) such as Hemopure are touted as a tenable substitute for red blood cells and therefore potential doping agents, although the mechanisms of oxygen transport of HBOCs are incompletely understood. We investigated whether infusion of Hemopure increased maximal oxygen uptake (V.O 2max) and endurance performance in healthy subjects. Twelve male subjects performed two 4-minute submaximal exercise bouts equivalent to 60 % and 75 % of V.O (2max) on a cycle ergometer, followed by a ramped incremental protocol to elicit V.O (2max). A crossover design tested the effect of infusing either 30 g (6 subjects) or 45 g (6 subjects) of Hemopure versus a placebo. Under our study conditions, Hemopure did not increase V.O (2max) nor endurance performance. However, the infusion of Hemopure caused a decrease in heart rate of approximately 10 bpm (p=0.009) and an average increase in mean ( approximately 7 mmHg) and diastolic blood pressure ( approximately 8 mmHg) (p=0.046) at submaximal and maximal exercise intensities. Infusion of Hemopure did not bestow the same physiological advantages generally associated with infusion of red blood cells. It is conceivable that under exercise conditions, the hypertensive effects of Hemopure counter the performance-enhancing effect of improved blood oxygen carrying capacity.

Potentiation Effects of Half-Squats Performed in a Ballistic or Nonballistic Manner.

PubMed

Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

2016-06-01

This study examined and compared the acute effects of ballistic and nonballistic concentric-only half-squats (COHSs) on squat jump performance. Fifteen resistance-trained men performed a squat jump 2 minutes after a control protocol or 2 COHSs at 90% of their 1 repetition maximum (1RM) COHS performed in a ballistic or nonballistic manner. Jump height (JH), peak power (PP), and allometrically scaled peak power (PPa) were compared using three 3 × 2 repeated-measures analyses of variance. Statistically significant condition × time interaction effects existed for JH (p = 0.037), PP (p = 0.041), and PPa (p = 0.031). Post hoc analysis revealed that the ballistic condition produced statistically greater JH (p = 0.017 and p = 0.036), PP (p = 0.031 and p = 0.026), and PPa (p = 0.024 and p = 0.023) than the control and nonballistic conditions, respectively. Small effect sizes for JH, PP, and PPa existed during the ballistic condition (d = 0.28-0.44), whereas trivial effect sizes existed during the control (d = 0.0-0.18) and nonballistic (d = 0.0-0.17) conditions. Large statistically significant relationships existed between the JH potentiation response and the subject's relative back squat 1RM (r = 0.520; p = 0.047) and relative COHS 1RM (r = 0.569; p = 0.027) during the ballistic condition. In addition, large statistically significant relationship existed between JH potentiation response and the subject's relative back squat strength (r = 0.633; p = 0.011), whereas the moderate relationship with the subject's relative COHS strength trended toward significance (r = 0.483; p = 0.068). Ballistic COHS produced superior potentiation effects compared with COHS performed in a nonballistic manner. Relative strength may contribute to the elicited potentiation response after ballistic and nonballistic COHS.

21 CFR 131.180 - Half-and-half.

Code of Federal Regulations, 2010 CFR

2010-04-01

...). (ii) Natural and artificial food flavoring. (c) Methods of analysis. The milkfat content is determined... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Half-and-half. 131.180 Section 131.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

21 CFR 131.180 - Half-and-half.

Code of Federal Regulations, 2013 CFR

2013-04-01

...). (ii) Natural and artificial food flavoring. (c) Methods of analysis. The milkfat content is determined... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Half-and-half. 131.180 Section 131.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

21 CFR 131.180 - Half-and-half.

Code of Federal Regulations, 2014 CFR

2014-04-01

...). (ii) Natural and artificial food flavoring. (c) Methods of analysis. The milkfat content is determined... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Half-and-half. 131.180 Section 131.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

21 CFR 131.180 - Half-and-half.

Code of Federal Regulations, 2011 CFR

2011-04-01

...). (ii) Natural and artificial food flavoring. (c) Methods of analysis. The milkfat content is determined... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Half-and-half. 131.180 Section 131.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

21 CFR 131.180 - Half-and-half.

Code of Federal Regulations, 2012 CFR

2012-04-01

...). (ii) Natural and artificial food flavoring. (c) Methods of analysis. The milkfat content is determined... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Half-and-half. 131.180 Section 131.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

Are running speeds maximized with simple-spring stance mechanics?

PubMed

Clark, Kenneth P; Weyand, Peter G

2014-09-15

Are the fastest running speeds achieved using the simple-spring stance mechanics predicted by the classic spring-mass model? We hypothesized that a passive, linear-spring model would not account for the running mechanics that maximize ground force application and speed. We tested this hypothesis by comparing patterns of ground force application across athletic specialization (competitive sprinters vs. athlete nonsprinters, n = 7 each) and running speed (top speeds vs. slower ones). Vertical ground reaction forces at 5.0 and 7.0 m/s, and individual top speeds (n = 797 total footfalls) were acquired while subjects ran on a custom, high-speed force treadmill. The goodness of fit between measured vertical force vs. time waveform patterns and the patterns predicted by the spring-mass model were assessed using the R(2) statistic (where an R(2) of 1.00 = perfect fit). As hypothesized, the force application patterns of the competitive sprinters deviated significantly more from the simple-spring pattern than those of the athlete, nonsprinters across the three test speeds (R(2) <0.85 vs. R(2) ≥ 0.91, respectively), and deviated most at top speed (R(2) = 0.78 ± 0.02). Sprinters attained faster top speeds than nonsprinters (10.4 ± 0.3 vs. 8.7 ± 0.3 m/s) by applying greater vertical forces during the first half (2.65 ± 0.05 vs. 2.21 ± 0.05 body wt), but not the second half (1.71 ± 0.04 vs. 1.73 ± 0.04 body wt) of the stance phase. We conclude that a passive, simple-spring model has limited application to sprint running performance because the swiftest runners use an asymmetrical pattern of force application to maximize ground reaction forces and attain faster speeds. Copyright © 2014 the American Physiological Society.

Maximal amplitudes of finite-gap solutions for the focusing Nonlinear Schrödinger Equation

NASA Astrophysics Data System (ADS)

Bertola, M.; Tovbis, A.

2017-09-01

Finite-gap (algebro-geometric) solutions to the focusing Nonlinear Schrödinger Equation (fNLS) i ψ_t + ψ_{xx} + 2|ψ|^2ψ=0, are quasi-periodic solutions that represent nonlinear multi-phase waves. In general, a finite-gap solution for (0-1) is defined by a collection of Schwarz symmetrical spectral bands and of real constants (initial phases), associated with the corresponding bands. In this paper we prove an interesting new formula for the maximal amplitude of a finite-gap solution to the focusing Nonlinear Schrödinger equation with given spectral bands: the amplitude does not exceed the sum of the imaginary parts of all the endpoints in the upper half plane. In the case of the straight vertical bands, that amounts to the half of the sum of the length of all the bands. The maximal amplitude will be attained for certain choices of the initial phases. This result is an important part of a criterion for the potential presence of the rogue waves in finite-gap solutions with a given set of spectral endpoints, obtained in Bertola et al. (Proc R Soc A, 2016. doi: 10.1098/rspa.2016.0340). A similar result was also obtained for the defocusing Nonlinear Schrödinger equation.

Do children exploit the Maxim of Antecedent in order to interpret ambiguous descriptions?

PubMed

Surian, L

1991-06-01

Twenty Italian six-year-olds and 20 eight-year-olds were asked to interpret eight ambiguous and eight clear definite descriptions. All ambiguous descriptions could refer to three drawings, one of which had been described by the subjects immediately before the comprehension task. In half of the trials with ambiguous messages the children's interlocutor was present while the children were describing the drawings; in the other half he was absent. In both conditions subjects showed a preference for the referents they had already described, indicating that they applied egocentrically a comprehension strategy based on the Maxim of Antecedent (Jackson & Jacobs, 1982). Children's failures to differentiate their responses in the two conditions are considered to be due to difficulties in taking account of the given-new distinction for relevant information.

Effect-site half-time for burst suppression is longer than for hypnosis during anaesthesia with sevoflurane.

PubMed

Kennedy, R R; Minto, C; Seethepalli, A

2008-01-01

The relationship between measures of drug effect such as bispectral index (BIS) and end-tidal (ET) levels of anaesthetic agents is described by the 'effect site equilibrium half-time', t(1/2)(ke0). There are limited data available on sevoflurane t(1/2)(ke0) during routine anaesthesia and surgery. Preliminary observations suggested t(1/2)(ke0) for the degree of hypnosis as estimated by BIS is different from that for burst suppression of the electroencephalograph, occurring at 'deep' levels of anaesthesia. This study aimed to determine and compare t(1/2)(ke0) for these two 'effects'. Large changes in ET sevoflurane were produced in 13 subjects during surgery. ET sevoflurane, BIS, and burst suppression ratio (BSR) were recorded every 10 s. Data were divided into epochs with BIS>30 (BIS) or with BSR>10% (burst suppression). Using a non-parametric modelling technique, t(1/2)(ke0) was determined for each epoch. There were 36 'BIS' and 20 burst suppression zones. Mean (sd) t(1/2)(ke0) for BIS was 3.48 (1.12) min and for BSR 9.9 (6.4) min. In all subjects, t(1/2)(ke0) BISeffect-site sevoflurane concentration producing a BIS of 50 was 1.23 (sd 0.34) vol% and for a BSR of 50% was 3.3 (0.50) vol%. There were considerable intra- and inter-subject variabilities. The different values of t(1/2)(ke0) for these effects suggest different sites or mechanisms of action. These results also establish values of t(1/2)(ke0) which can be used to provide the real-time estimates of effect-site sevoflurane concentration in clinical practice.

The effect of dietary cation-anion difference concentration and cation source on milk production and feed efficiency in lactating dairy cows.

PubMed

Iwaniuk, M E; Weidman, A E; Erdman, R A

2015-03-01

Feed costs currently account for 55% or more of the total cost of milk production in US dairy herds, and dairy producers are looking for strategies to improve feed efficiency [FE; 3.5% fat-corrected milk (FCM) per dry matter (DM) intake]. Increasing dietary cation-anion difference [DCAD; Na+K-Cl (mEq/kg of DM)] has been shown to increase milk production, FCM, and FE. However, the optimal DCAD concentration for maximal FE has yet to be determined. The objectives of this research were to test the effects of DCAD concentration and cation source on dairy FE. Sixty Holstein dairy cows (20 cows per experiment) were used in three 4×4 Latin square design experiments with 3-wk experimental periods. In experiments 1 and 2, we tested the effect of DCAD concentration: cows were fed a basal diet containing ~250 mEq/kg of DM DCAD that was supplemented with potassium carbonate at 0, 50, 100, and 150 mEq/kg of DM or 0, 125, 250, and 375 mEq/kg of DM in experiments 1 and 2, respectively. In experiment 3, we tested the effect of cation source: sodium sesquicarbonate replaced 0, 33, 67, and 100% of the supplemental potassium carbonate (150 mEq/kg of DM DCAD). The DCAD concentration had no effect on milk production, milk protein concentration, or milk protein yield in experiments 1 and 2. Dry matter intake was not affected by DCAD concentration in experiment 1 or by cation source in experiment 3. However, DMI increased linearly with increasing DCAD in experiment 2. We detected a linear increase in milk fat concentration and yield with increasing DCAD in experiments 1 and 2 and by substituting sodium sesquicarbonate for potassium carbonate in experiment 3. Increased milk fat concentration with increasing DCAD led to increases in 3.5% FCM in experiments 1 and 2. Maximal dairy FE was achieved at a DCAD concentration of 426 mEq/kg of DM in experiments 1 and 2 and by substituting Na for K in experiment 3. The results of these experiments suggest that both DCAD concentration and the cation

Plasma concentration of ketorolac after local infiltration analgesia in hip arthroplasty.

PubMed

Affas, F; Eksborg, S; Wretenberg, P; Olofsson, C; Stephanson, N; Stiller, C-O

2014-10-01

Local infiltration analgesia (LIA) with local anaesthetic (ropivacaine), a nonsteroidal anti-inflammatory drug (ketorolac) and epinephrine after lower extremity arthroplasty has gained increasing popularity during the last decade. This method has certain advantages, which include minimal systemic side effects, faster post-operative mobilization, earlier post-operative discharge from hospital and less opioid consumption. However, information regarding plasma concentrations of ketorolac after LIA mixture is insufficient to predict the risk of renal impairment in patients subjected to arthroplasty. To determine the maximal plasma concentration and the exposure of ketorolac during the first 30 h following LIA in hip arthroplasty. Thirteen patients scheduled for primary total hip arthroplasty with LIA (ropivacaine 200 mg, ketorolac 30 mg and epinephrine 0.5 mg in a volume of 106 ml) were included. Plasma concentration of ketorolac was quantified by liquid chromatography-mass spectrometry. In addition, we assessed the effect of increasing age and decreasing glomerular filtration rate on the maximal plasma concentration and the total exposure to ketorolac during 30 h. The range of the maximal plasma concentration, 0.3-2.2 mg/l, was detected 30 min-4 h after completing the infiltration. Similar plasma levels have been reported after intramuscular injection of the same dose of ketorolac to healthy elderly volunteers. Exposure to ketorolac after LIA may be comparable to an intramuscular injection of the same dose. Decision of dose reduction should be based on clinical assessment of risk factors. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Effects of warm-up on vertical jump performance and muscle electrical activity using half-squats at low and moderate intensity.

PubMed

Sotiropoulos, Konstantinos; Smilios, Ilias; Christou, Marios; Barzouka, Karolina; Spaias, Angelos; Douda, Helen; Tokmakidis, Savvas P

2010-01-01

The purpose of this study was to determine the effects of a specific warm-up using half-squats at low and moderate intensity on vertical jump performance and electromyographic activity of the thigh muscles. The subjects were 26 men who were divided into a low intensity group (LIG; n = 13) and a moderate intensity group (MIG; n = 13). The LIG performed a specific warm-up protocol that included the explosive execution of half-squats with loads 25 and 35% of the one repetition maximum (1RM) and the MIG with loads 45 and 65% of the 1RM. The two groups performed a countermovement jump (CMJ) before and three minutes after the specific warm-up protocols. During the concentric phase of the CMJ a linear encoder connected to an A/D converter interfaced to a PC with a software for data acquisition and analysis allowed the calculation of average mechanical power. The electromyographic (EMG) activity of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) were recorded during the concentric phase of the jumps. The average quadriceps (Qc) activity (mean value of the VL, VM and RF) was also calculated. A two way ANOVA (protocols X time) with repeated measures on the second factor was used to analyze the data. Following the specific warm-up procedure both groups improved (p ≤ 0.05) CMJ performance and mechanical power by 3.5% and 6.3%, respectively, with no differences observed between the two groups. EMG activity of the Qc and VL increased (p ≤ 0.05) for both groups by 5.9% and 8.5%, respectively. It is concluded that the use of a specific warm-up that includes half-squats, performed explosively with low to moderate intensity, improves CMJ performance. This may be due to increased muscle activation as evaluated by the surface EMG. Key pointsThe inclusion of two sets of explosively performed half squats with low to moderate loads in the warm up procedure elicited an acute performance en-hancement.The performance was enhanced regardless of the load used in

Effects of Warm-Up on Vertical Jump Performance and Muscle Electrical Activity Using Half-Squats at Low and Moderate Intensity

PubMed Central

Sotiropoulos, Konstantinos; Smilios, Ilias; Christou, Marios; Barzouka, Karolina; Spaias, Angelos; Douda, Helen; Tokmakidis, Savvas p.

2010-01-01

The purpose of this study was to determine the effects of a specific warm-up using half-squats at low and moderate intensity on vertical jump performance and electromyographic activity of the thigh muscles. The subjects were 26 men who were divided into a low intensity group (LIG; n = 13) and a moderate intensity group (MIG; n = 13). The LIG performed a specific warm-up protocol that included the explosive execution of half-squats with loads 25 and 35% of the one repetition maximum (1RM) and the MIG with loads 45 and 65% of the 1RM. The two groups performed a countermovement jump (CMJ) before and three minutes after the specific warm-up protocols. During the concentric phase of the CMJ a linear encoder connected to an A/D converter interfaced to a PC with a software for data acquisition and analysis allowed the calculation of average mechanical power. The electromyographic (EMG) activity of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) were recorded during the concentric phase of the jumps. The average quadriceps (Qc) activity (mean value of the VL, VM and RF) was also calculated. A two way ANOVA (protocols X time) with repeated measures on the second factor was used to analyze the data. Following the specific warm-up procedure both groups improved (p ≤ 0.05) CMJ performance and mechanical power by 3.5% and 6.3%, respectively, with no differences observed between the two groups. EMG activity of the Qc and VL increased (p ≤ 0.05) for both groups by 5.9% and 8.5%, respectively. It is concluded that the use of a specific warm-up that includes half-squats, performed explosively with low to moderate intensity, improves CMJ performance. This may be due to increased muscle activation as evaluated by the surface EMG. Key points The inclusion of two sets of explosively performed half squats with low to moderate loads in the warm up procedure elicited an acute performance en-hancement. The performance was enhanced regardless of the load used in

Electroencephalographic patterns of lithium poisoning: a study of the effect/concentration relationships in the rat.

PubMed

Hanak, Anne-Sophie; Malissin, Isabelle; Poupon, Joël; Risède, Patricia; Chevillard, Lucie; Mégarbane, Bruno

2017-03-01

Lithium overdose may result in encephalopathy and electroencephalographic abnormalities. Three poisoning patterns have been identified based on the ingested dose, previous treatment duration and renal function. Whether the severity of lithium-induced encephalopathy depends on the poisoning pattern has not been established. We designed a rat study to investigate lithium-induced encephalopathy and correlate its severity to plasma, erythrocyte, cerebrospinal fluid and brain lithium concentrations previously determined in rat models mimicking human poisoning patterns. Lithium-induced encephalopathy was assessed and scored using continuous electroencephalography. We demonstrated that lithium overdose was consistently responsible for encephalopathy, the severity of which depended on the poisoning pattern. Acutely poisoned rats developed rapid-onset encephalopathy which reached a maximal grade of 2/5 at 6 h and disappeared at 24 h post-injection. Acute-on-chronically poisoned rats developed persistent and slightly fluctuating encephalopathy which reached a maximal grade of 3/5. Chronically poisoned rats developed rapid-onset but gradually increasing life-threatening encephalopathy which reached a maximal grade of 4/5. None of the acutely, 20% of the acute-on-chronically and 57% of the chronically lithium-poisoned rats developed seizures. The relationships between encephalopathy severity and lithium concentrations fitted a sigmoidal E max model based on cerebrospinal fluid concentrations in acute poisoning and brain concentrations in acute-on-chronic poisoning. In chronic poisoning, worsening of encephalopathy paralleled the increase in plasma lithium concentrations. The severity of lithium-induced encephalopathy is dependent on the poisoning pattern, which was previously shown to determine lithium accumulation in the brain. Our data support the proposition that electroencephalography is a sensitive tool for scoring lithium-related neurotoxicity. © 2017 John Wiley

Thermodynamic efficiency of nonimaging concentrators

NASA Astrophysics Data System (ADS)

Shatz, Narkis; Bortz, John; Winston, Roland

2009-08-01

The purpose of a nonimaging concentrator is to transfer maximal flux from the phase space of a source to that of a target. A concentrator's performance can be expressed relative to a thermodynamic reference. We discuss consequences of Fermat's principle of geometrical optics. We review étendue dilution and optical loss mechanisms associated with nonimaging concentrators, especially for the photovoltaic (PV) role. We introduce the concept of optical thermodynamic efficiency which is a performance metric combining the first and second laws of thermodynamics. The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. Examples are provided to illustrate the use of this new metric. In particular we discuss concentrating PV systems for solar power applications.

Maximal strength training improves work economy, rate of force development and maximal strength more than conventional strength training.

PubMed

Heggelund, Jørn; Fimland, Marius S; Helgerud, Jan; Hoff, Jan

2013-06-01

This study compared maximal strength training (MST) with equal training volume (kg × sets × repetitions) of conventional strength training (CON) primarily with regard to work economy, and second one repetition maximum (1RM) and rate of force development (RFD) of single leg knee extension. In an intra-individual design, one leg was randomized to knee-extension MST (4 or 5RM) and the other leg to CON (3 × 10RM) three times per week for 8 weeks. MST was performed with maximal concentric mobilization of force while CON was performed with moderate velocity. Eight untrained or moderately trained men (26 ± 1 years) completed the study. The improvement in gross work economy was -0.10 ± 0.08 L min(-1) larger after MST (P = 0.011, between groups). From pre- to post-test the MST and CON improved net work economy with 31 % (P < 0.001) and 18 % (P = 0.01), respectively. Compared with CON, the improvement in 1RM and dynamic RFD was 13.7 ± 8.4 kg (P = 0.002) and 587 ± 679 N s(-1) (P = 0.044) larger after MST, whereas isometric RFD was of borderline significance 3,028 ± 3,674 N s(-1) (P = 0.053). From pre- to post-test, MST improved 1RM and isometric RFD with 50 % (P < 0.001) and 155 % (P < 0.001), respectively whereas CON improved 1RM and isometric RFD with 35 % (P < 0.001) and 83 % (P = 0.028), respectively. Anthropometric measures of quadriceps femoris muscle mass and peak oxygen uptake did not change. In conclusion, 8 weeks of MST was more effective than CON for improving work economy, 1RM and RFD in untrained and moderately trained men. The advantageous effect of MST to improve work economy could be due to larger improvements in 1RM and RFD.

CO 2 water-alternating-gas injection for enhanced oil recovery: Optimal well controls and half-cycle lengths

DOE PAGES

Chen, Bailian; Reynolds, Albert C.

2018-03-11

We report that CO 2 water-alternating-gas (WAG) injection is an enhanced oil recovery method designed to improve sweep efficiency during CO 2 injection with the injected water to control the mobility of CO 2 and to stabilize the gas front. Optimization of CO 2 -WAG injection is widely regarded as a viable technique for controlling the CO 2 and oil miscible process. Poor recovery from CO 2 -WAG injection can be caused by inappropriately designed WAG parameters. In previous study (Chen and Reynolds, 2016), we proposed an algorithm to optimize the well controls which maximize the life-cycle net-present-value (NPV). However,more » the effect of injection half-cycle lengths for each injector on oil recovery or NPV has not been well investigated. In this paper, an optimization framework based on augmented Lagrangian method and the newly developed stochastic-simplex-approximate-gradient (StoSAG) algorithm is proposed to explore the possibility of simultaneous optimization of the WAG half-cycle lengths together with the well controls. Finally, the proposed framework is demonstrated with three reservoir examples.« less

CO 2 water-alternating-gas injection for enhanced oil recovery: Optimal well controls and half-cycle lengths

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Bailian; Reynolds, Albert C.

We report that CO 2 water-alternating-gas (WAG) injection is an enhanced oil recovery method designed to improve sweep efficiency during CO 2 injection with the injected water to control the mobility of CO 2 and to stabilize the gas front. Optimization of CO 2 -WAG injection is widely regarded as a viable technique for controlling the CO 2 and oil miscible process. Poor recovery from CO 2 -WAG injection can be caused by inappropriately designed WAG parameters. In previous study (Chen and Reynolds, 2016), we proposed an algorithm to optimize the well controls which maximize the life-cycle net-present-value (NPV). However,more » the effect of injection half-cycle lengths for each injector on oil recovery or NPV has not been well investigated. In this paper, an optimization framework based on augmented Lagrangian method and the newly developed stochastic-simplex-approximate-gradient (StoSAG) algorithm is proposed to explore the possibility of simultaneous optimization of the WAG half-cycle lengths together with the well controls. Finally, the proposed framework is demonstrated with three reservoir examples.« less

Occupation of the cytochrome P450 substrate pocket by diverse compounds at general anesthesia concentrations.

PubMed

LaBella, F S; Stein, D; Queen, G

1998-10-02

Each of a diverse array of compounds, at concentrations reported to effect general anesthesia, when added to liver microsomes, forms a complex with cytochromes P450 to generate, with reference to a cuvette containing microsomes only, a characteristic absorbance-difference spectrum. This spectrum results from a change in the electron-spin state of the heme iron atom induced upon entry by the anesthetic molecule into the enzyme catalytic pocket. The difference spectrum, representing the anesthetic-P450 complex, is characteristic of substances that are substrates for the enzyme. For the group of compounds as a whole, the magnitudes of the absorbance-difference spectra vary only about twofold, although the anesthetic potencies vary by several orders of magnitude. The dissociation constants (Ks), calculated from absorbance data and representing affinities of the anesthetics for P450, agree closely with the respective EC50 (concentration that effects anesthesia in 50% of individuals) values, and with the respective Ki (concentration that inhibits P450 catalytic activities half-maximally) values reported by us previously. The absorbance complex resulting from the occupation of the catalytic pocket by endogenous substrates, androstenedione and arachidonic acid, is inhibited, competitively, by anesthetics. Occupation of and perturbation of the heme catalytic pocket by anesthetic, as monitored by the absorbance-difference spectrum, is rapidly reversible. The presumed in vivo consequences of perturbation by general anesthetics of heme proteins is suppression of the generation of chemical signals that determine cell sensitivity and response.

Analysis of the negative inotropic effect of acetylcholine on frog atrial fibres.

PubMed

Nargeot, J; Garnier, D; Rougier, O

1981-03-01

Voltage-clamp experiments have been performed on frog atrial preparations in order to study the mechanism of the inotropic effect of acetylcholine (ACh) at various concentrations. The amplitude of the slow inward current (Is) is reduced even at low ACh concentrations; such low concentrations have little or no effect on potassium permeability. Dose-effect relationships for Is inhibition (Is/Is max) by ACh show a half amplitude dose (K0.5 around 8 X 10(-8) M ACh. The reduction of Is is attributed largely to a decrease of the maximal conductance of the slow channel (gs). Steady-state activation and inactivation parameters are not affected by ACh. Experiments in a Na-free solution (Na replaced by Li ions) or in a Ca-free solution (with EGTA) indicate that the "slow sodium current" is more sensitive to ACh than the "slow Ca current", although these two currents both seem to flow through the slow channel. The decrease of the phasic component of contraction observed in the presence of ACh is very well correlated with the decrease of Is (K0.5 = 8 X 10(-8) M ACh), while the increase of the tonic tension may be related to the outward potassium current induced by high concentrations of ACh. The significant difference between the half amplitude dose (K0.5) observed in the dose effect curves with ACh for Is inhibition (K0.5 = 8 X 10(-8) M) and for ACh-induced extra-current (K0.5 - 10(-6) M) may indicate the presence of two muscarinic receptors.

Relationships Between Potentiation Effects After Ballistic Half-Squats and Bilateral Symmetry.

PubMed

Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

2016-05-01

The purposes of this study were to examine the effect of ballistic concentric-only half-squats (COHS) on subsequent squat-jump (SJ) performances at various rest intervals and to examine the relationships between changes in SJ performance and bilateral symmetry at peak performance. Thirteen resistance-trained men performed an SJ immediately and every minute up to 10 min on dual force plates after 2 ballistic COHS repetitions at 90% of their 1-repetition-maximum COHS. SJ peak force, peak power, net impulse, and rate of force development (RFD) were compared using a series of 1-way repeated-measures ANOVAs. The percent change in performance at which peak performance occurred for each variable was correlated with the symmetry index scores at the corresponding time point using Pearson correlation coefficients. Statistical differences in peak power (P = .031) existed between rest intervals; however, no statistically significant pairwise comparisons were present (P > .05). No statistical differences in peak force (P = .201), net impulse (P = .064), and RFD (P = .477) were present between rest intervals. The relationships between changes in SJ performance and bilateral symmetry after the rest interval that produced the greatest performance for peak force (r = .300, P = .319), peak power (r = -.041, P = .894), net impulse (r = -.028, P = .927), and RFD (r = -.434, P = .138) were not statistically significant. Ballistic COHS may enhance SJ performance; however, the changes in performance were not related to bilateral symmetry.

Effects of volume-based overload plyometric training on maximal-intensity exercise adaptations in young basketball players.

PubMed

Asadi, Abbas; Ramirez-Campillo, Rodrigo; Meylan, Cesar; Nakamura, Fabio Y; Cañas-Jamett, Rodrigo; Izquierdo, Mikel

2017-12-01

The aim of the present study was to compare maximal-intensity exercise adaptations in young basketball players (who were strong individuals at baseline) participating in regular basketball training versus regular plus a volume-based plyometric training program in the pre-season period. Young basketball players were recruited and assigned either to a plyometric with regular basketball training group (experimental group [EG]; N.=8), or a basketball training only group (control group [CG]; N.=8). The athletes in EG performed periodized (i.e., from 117 to 183 jumps per session) plyometric training for eight weeks. Before and after the intervention, players were assessed in vertical and broad jump, change of direction, maximal strength and a 60-meter sprint test. No significant improvements were found in the CG, while the EG improved vertical jump (effect size [ES] 2.8), broad jump (ES=2.4), agility T test (ES=2.2), Illinois agility test (ES=1.4), maximal strength (ES=1.8), and 60-m sprint (ES=1.6) (P<0.05) after intervention, and the improvements were greater compared to the CG (P<0.05). Plyometric training in addition to regular basketball practice can lead to meaningful improvements in maximal-intensity exercise adaptations among young basketball players during the pre-season.

Estimating potency for the Emax-model without attaining maximal effects.

PubMed

Schoemaker, R C; van Gerven, J M; Cohen, A F

1998-10-01

The most widely applied model relating drug concentrations to effects is the Emax model. In practice, concentration-effect relationships often deviate from a simple linear relationship but without reaching a clear maximum because a further increase in concentration might be associated with unacceptable or distorting side effects. The parameters for the Emax model can only be estimated with reasonable precision if the curve shows sign of reaching a maximum, otherwise both EC50 and Emax estimates may be extremely imprecise. This paper provides a solution by introducing a new parameter (S0) equal to Emax/EC50 that can be used to characterize potency adequately even if there are no signs of a clear maximum. Simulations are presented to investigate the nature of the new parameter and published examples are used as illustration.

Effect of 29 days of simulated microgravity on maximal oxygen consumption and fat-free mass of rats

NASA Technical Reports Server (NTRS)

Woodman, Christopher R.; Stump, Craig S.; Stump, Jane A.; Rahman, Zia; Tipton, Charles M.

1991-01-01

Effects of a 29-days exposure to simulated microgravity on the values of maximal oxygen consumption and fat-free mass (FFM) and on the mechanical efficiency of running were investigated in rats randomly assigned to one of three regimens: head-down suspension (HDS) at 45 deg, horizontal suspension (HS), or cage control (CC). Before suspension and on days 7, 14, 21, and 28, five exercise performance tests were carried out, with measurements related to maximal oxygen consumption, treadmill run time, and mechanical efficiency. It was found that maximal oxygen consumption of both HDS and HS groups decreased significantly at day 7, after which the HDS rats remained decreased while the HS rats returned to presuspension values. Apparent mechanical efficiency in the HDS and HS groups decreased by 22-35 percent during the experimental period, and FFM decreased significantly.

[Acute physical exercise increases homocysteine concentrations in young trained male subjects].

PubMed

Maroto-Sánchez, Beatriz; Valtueña, Jara; Albers, Ulrike; Benito, Pedro J; González-Gross, Marcela

2013-01-01

High levels of homocysteine (Hcy) have been identified as a cardiovascular risk factor. Regarding physical exercise, the results are contradictory. The aim of this study was to determine the influence of maximal intensity exercise and submaximal constant exercise on total serum homocysteine concentrations (tHcy) and other related parameters. Ten physically active male subjects (mean age: 23.51 ± 1.84), performed two treadmill tests, a maximal test and a stable submaximal test at an intensity of 65% of maximal oxygen uptake (VO2max). Serum concentrations of tHcy, Folate, Vitamin B12 and creatinine were analysed before and after each test. Significant increase in serum tHcy concentrations after the maximal (p < 0.05) and submaximal (p < 0.01) tests were observed. Folate and vitamin B12 concentrations also increased significantly after both tests (p < 0.05). Creatinine levels increased only after the maximal test (p < 0.001). A statistically significant inverse relationship was found between folate and tHcy concentrations (p < 0.05) at all the measurement points. THcy levels increased significantly after acute exercise in both maximum and submaximal intensity exercises. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

Phosphate metabolite concentrations and ATP hydrolysis potential in normal and ischaemic hearts

PubMed Central

Wu, Fan; Zhang, Eric Y; Zhang, Jianyi; Bache, Robert J; Beard, Daniel A

2008-01-01

To understand how cardiac ATP and CrP remain stable with changes in work rate – a phenomenon that has eluded mechanistic explanation for decades – data from 31phosphate-magnetic resonance spectroscopy (31P-MRS) are analysed to estimate cytoplasmic and mitochondrial phosphate metabolite concentrations in the normal state, during high cardiac workstates, during acute ischaemia and reactive hyperaemic recovery. Analysis is based on simulating distributed heterogeneous oxygen transport in the myocardium integrated with a detailed model of cardiac energy metabolism. The model predicts that baseline myocardial free inorganic phosphate (Pi) concentration in the canine myocyte cytoplasm – a variable not accessible to direct non-invasive measurement – is approximately 0.29 mm and increases to 2.3 mm near maximal cardiac oxygen consumption. During acute ischaemia (from ligation of the left anterior descending artery) Pi increases to approximately 3.1 mm and ATP consumption in the ischaemic tissue is reduced quickly to less than half its baseline value before the creatine phosphate (CrP) pool is 18% depleted. It is determined from these experiments that the maximal rate of oxygen consumption of the heart is an emergent property and is limited not simply by the maximal rate of ATP synthesis, but by the maximal rate at which ATP can be synthesized at a potential at which it can be utilized. The critical free energy of ATP hydrolysis for cardiac contraction that is consistent with these findings is approximately −63.5 kJ mol−1. Based on theoretical findings, we hypothesize that inorganic phosphate is both the primary feedback signal for stimulating oxidative phosphorylation in vivo and also the most significant product of ATP hydrolysis in limiting the capacity of the heart to hydrolyse ATP in vivo. Due to the lack of precise quantification of Piin vivo, these hypotheses and associated model predictions remain to be carefully tested experimentally. PMID:18617566

Superior Effects of Eccentric to Concentric Knee Extensor Resistance Training on Physical Fitness, Insulin Sensitivity and Lipid Profiles of Elderly Men

PubMed Central

Chen, Trevor Chung-Ching; Tseng, Wei-Chin; Huang, Guan-Ling; Chen, Hsin-Lian; Tseng, Kuo-Wei; Nosaka, Kazunori

2017-01-01

It has been reported that eccentric training of knee extensors is effective for improving blood insulin sensitivity and lipid profiles to a greater extent than concentric training in young women. However, it is not known whether this is also the case for elderly individuals. Thus, the present study tested the hypothesis that eccentric training of the knee extensors would improve physical function and health parameters (e.g., blood lipid profiles) of older adults better than concentric training. Healthy elderly men (60–76 years) were assigned to either eccentric training or concentric training group (n = 13/group), and performed 30–60 eccentric or concentric contractions of knee extensors once a week. The intensity was progressively increased over 12 weeks from 10 to 100% of maximal concentric strength for eccentric training and from 50 to 100% for concentric training. Outcome measures were taken before and 4 days after the training period. The results showed that no sings of muscle damage were observed after any sessions. Functional physical fitness (e.g., 30-s chair stand) and maximal concentric contraction strength of the knee extensors increased greater (P ≤ 0.05) after eccentric training than concentric training. Homeostasis model assessment, oral glucose tolerance test and whole blood glycosylated hemoglobin showed improvement of insulin sensitivity only after eccentric training (P ≤ 0.05). Greater (P ≤ 0.05) decreases in fasting triacylglycerols, total, and low-density lipoprotein cholesterols were evident after eccentric training than concentric training, and high-density lipoprotein cholesterols increased only after eccentric training. These results support the hypothesis and suggest that it is better to focus on eccentric contractions in exercise medicine. PMID:28443029

Why Contextual Preference Reversals Maximize Expected Value

PubMed Central

2016-01-01

Contextual preference reversals occur when a preference for one option over another is reversed by the addition of further options. It has been argued that the occurrence of preference reversals in human behavior shows that people violate the axioms of rational choice and that people are not, therefore, expected value maximizers. In contrast, we demonstrate that if a person is only able to make noisy calculations of expected value and noisy observations of the ordinal relations among option features, then the expected value maximizing choice is influenced by the addition of new options and does give rise to apparent preference reversals. We explore the implications of expected value maximizing choice, conditioned on noisy observations, for a range of contextual preference reversal types—including attraction, compromise, similarity, and phantom effects. These preference reversal types have played a key role in the development of models of human choice. We conclude that experiments demonstrating contextual preference reversals are not evidence for irrationality. They are, however, a consequence of expected value maximization given noisy observations. PMID:27337391

From entropy-maximization to equality-maximization: Gauss, Laplace, Pareto, and Subbotin

NASA Astrophysics Data System (ADS)

Eliazar, Iddo

2014-12-01

The entropy-maximization paradigm of statistical physics is well known to generate the omnipresent Gauss law. In this paper we establish an analogous socioeconomic model which maximizes social equality, rather than physical disorder, in the context of the distributions of income and wealth in human societies. We show that-on a logarithmic scale-the Laplace law is the socioeconomic equality-maximizing counterpart of the physical entropy-maximizing Gauss law, and that this law manifests an optimized balance between two opposing forces: (i) the rich and powerful, striving to amass ever more wealth, and thus to increase social inequality; and (ii) the masses, struggling to form more egalitarian societies, and thus to increase social equality. Our results lead from log-Gauss statistics to log-Laplace statistics, yield Paretian power-law tails of income and wealth distributions, and show how the emergence of a middle-class depends on the underlying levels of socioeconomic inequality and variability. Also, in the context of asset-prices with Laplace-distributed returns, our results imply that financial markets generate an optimized balance between risk and predictability.

Two prospective Li-based half-Heusler alloys for spintronic applications based on structural stability and spin–orbit effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, R. L.; Damewood, L.; Zeng, Y. J.

To search for half-metallic materials for spintronic applications, instead of using an expensive trial-and-error experimental scheme, it is more efficient to use first-principles calculations to design materials first, and then grow them. In particular, using a priori information of the structural stability and the effect of the spin–orbit interaction (SOI) enables experimentalists to focus on favorable properties that make growing half-metals easier. We suggest that using acoustic phonon spectra is the best way to address the stability of promising half-metallic materials. Additionally, by carrying out accurate first-principles calculations, we propose two criteria for neglecting the SOI so the half-metallicity persists.more » As a result, based on the mechanical stability and the negligible SOI, we identified two half-metals, β-LiCrAs and β-LiMnSi, as promising half-Heusler alloys worth growing.« less

Two prospective Li-based half-Heusler alloys for spintronic applications based on structural stability and spin–orbit effect

DOE PAGES

Zhang, R. L.; Damewood, L.; Zeng, Y. J.; ...

2017-07-07

To search for half-metallic materials for spintronic applications, instead of using an expensive trial-and-error experimental scheme, it is more efficient to use first-principles calculations to design materials first, and then grow them. In particular, using a priori information of the structural stability and the effect of the spin–orbit interaction (SOI) enables experimentalists to focus on favorable properties that make growing half-metals easier. We suggest that using acoustic phonon spectra is the best way to address the stability of promising half-metallic materials. Additionally, by carrying out accurate first-principles calculations, we propose two criteria for neglecting the SOI so the half-metallicity persists.more » As a result, based on the mechanical stability and the negligible SOI, we identified two half-metals, β-LiCrAs and β-LiMnSi, as promising half-Heusler alloys worth growing.« less

Influence of simulated weightlessness on maximal oxygen uptake of untrained rats

NASA Technical Reports Server (NTRS)

Overton, J. Michael; Tipton, Charles M.

1987-01-01

The purpose of this study was to determine the effect of hindlimb suspension on maximal oxygen uptake of rodents. Male Sprague-Dawley rats were assigned to head-down (HD) suspension, horizontal (HOZ) suspension, or cage (C) control for 6-9 days. Rats were tested for maximal oxygen uptake before and after surgical instrumentation (Doppler flow probes, carotid and jugular cannulae), and after suspension. Body weight was significantly decreased after suspension in both HD and HOZ groups, but was significantly increased in the C group. Absolute maximal O2 uptake (ml/min) was not different in the C group. However, because of their increased weight, relative maximal O2 uptake (ml/min per kg) was significantly reduced. In contrast, both relative and absolute maximal O2 uptake were significantly lower, following suspension, for the HD and HOZ groups. These preliminary results support the use of hindlimb suspension as an effective model to study the mechanism(s) of cardiovascular deconditioning.

Effects of a short-term personalized Intermittent Work Exercise Program (IWEP) on maximal cardio-respiratory function and endurance parameters among healthy young and older seniors.

PubMed

Vogel, T; Leprêtre, P-M; Brechat, P-H; Lonsdorfer, E; Benetos, A; Kaltenbach, G; Lonsdorfer, J

2011-12-01

The aim of this study was to evaluate the efficiency of a short-term Intermittent Work Exercise Program (IWEP) among healthy elderly subjects. This longitudinal prospective study took place at the Strasbourg University Hospital geriatric department. One hundred and fifty older volunteers, previously determined as being free from cardiac and pulmonary disease, were separated into two age groups: the "young senior" (60.2 ± 3.1 yr) and the "older senior" groups (70.8 ± 5.2 yr). These groups were then subdivided by gender into the "young female senior", "young male senior" "older female senior" and "older male senior" groups. Before and after the IWEP, all subjects were asked to perform an incremental cycle exercise to obtain their first ventilatory threshold (VT1), maximal tolerated power (MTP), peak oxygen uptake (VO2peak) and maximal minute ventilation (MMV). The IWEP consisted of a 30-min cycling exercise which took place twice a week, and was divided into six 5-min stages consisting of 4 min at VT1 intensity and 1 min at 90% MTP. An assessment was made of the effects of the IWEP on maximal cardio-respiratory function (MTP, VO2peak, MMV) and endurance parameters (VT1, heart rate [HR] measured at pretraining VT1 and lactate concentrations at pre-training MTP). This short-term training program resulted in a significant increase of MTP (from 13.2% to 20.6%), VO2peak (from 8.9% to 16.6%) and MMV (from 11.1% to 21.8%) in all groups (p<0.05). VT1 improved from 21% at pretraining to 27%, while HR at pre-training VT1 as well as lactate concentrations at pre-training MTP decreased significantly in all groups (p<0.05). The post-training values for VO2peak and MMV of the "older seniors" were not significantly different (p>0.05) from the "young seniors" pre-training values for the same parameters. The most striking finding in this study is that after only 9 weeks, our short-term "individually-tailored" IWEP significantly improved both maximal cardio-respiratory function and

Laboratory evaluation of the particle size effect on the performance of an elastomeric half-mask respirator against ultrafine combustion particles.

PubMed

He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; Yermakov, Michael; McKay, Roy; Haruta, Hiroki; Kimura, Kazushi

2013-08-01

This study quantified the particle size effect on the performance of elastomeric half-mask respirators, which are widely used by firefighters and first responders exposed to combustion aerosols. One type of elastomeric half-mask respirator equipped with two P-100 filters was donned on a breathing manikin while challenged with three combustion aerosols (originated by burning wood, paper, and plastic). Testing was conducted with respirators that were fully sealed, partially sealed (nose area only), or unsealed to the face of a breathing manikin to simulate different faceseal leakages. Three cyclic flows with mean inspiratory flow (MIF) rates of 30, 85, and 135 L/min were tested for each combination of sealing condition and combustion material. Additional testing was performed with plastic combustion particles at other cyclic and constant flows. Particle penetration was determined by measuring particle number concentrations inside and outside the respirator with size ranges from 20 to 200 nm. Breathing flow rate, particle size, and combustion material all had significant effects on the performance of the respirator. For the partially sealed and unsealed respirators, the penetration through the faceseal leakage reached maximum at particle sizes >100 nm when challenged with plastic aerosol, whereas no clear peaks were observed for wood and paper aerosols. The particles aerosolized by burning plastic penetrated more readily into the unsealed half-mask than those aerosolized by the combustion of wood and paper. The difference may be attributed to the fact that plastic combustion particles differ from wood and paper particles by physical characteristics such as charge, shape, and density. For the partially sealed respirator, the highest penetration values were obtained at MIF = 85 L/min. The unsealed respirator had approximately 10-fold greater penetration than the one partially sealed around the bridge of the nose, which indicates that the nose area was the primary leak

The effect of acute maximal exercise on postexercise hemodynamics and central arterial stiffness in obese and normal-weight individuals.

PubMed

Bunsawat, Kanokwan; Ranadive, Sushant M; Lane-Cordova, Abbi D; Yan, Huimin; Kappus, Rebecca M; Fernhall, Bo; Baynard, Tracy

2017-04-01

Central arterial stiffness is associated with incident hypertension and negative cardiovascular outcomes. Obese individuals have higher central blood pressure (BP) and central arterial stiffness than their normal-weight counterparts, but it is unclear whether obesity also affects hemodynamics and central arterial stiffness after maximal exercise. We evaluated central hemodynamics and arterial stiffness during recovery from acute maximal aerobic exercise in obese and normal-weight individuals. Forty-six normal-weight and twenty-one obese individuals underwent measurements of central BP and central arterial stiffness at rest and 15 and 30 min following acute maximal exercise. Central BP and normalized augmentation index (AIx@75) were derived from radial artery applanation tonometry, and central arterial stiffness was obtained via carotid-femoral pulse wave velocity (cPWV) and corrected for central mean arterial pressure (cPWV/cMAP). Central arterial stiffness increased in obese individuals but decreased in normal-weight individuals following acute maximal exercise, after adjusting for fitness. Obese individuals also exhibited an overall higher central BP ( P  <   0.05), with no exercise effect. The increase in heart rate was greater in obese versus normal-weight individuals following exercise ( P  <   0.05), but there was no group differences or exercise effect for AIx@75 In conclusion, obese (but not normal-weight) individuals increased central arterial stiffness following acute maximal exercise. An assessment of arterial stiffness response to acute exercise may serve as a useful detection tool for subclinical vascular dysfunction. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Maximal aerobic power in cycle ergometry in middle-aged men and women, active in sports, in relation to age and physical activity.

PubMed

Bovens, A M; van Baak, M A; Vrencken, J G; Wijnen, J A; Saris, W H; Verstappen, F T

1993-02-01

Reliable standards of maximal power output in middle-aged and physically active men and women are desirable in sports-medical practice. For this purpose maximal cycle ergometer tests were evaluated in 2038 men and 898 women over 40 years of age (46.8 +/- 6.1 years (mean +/- SD) and 47.5 +/- 6.6 years), who volunteered in a sports-medical check-up and all of whom were active in sports for at least three months in the year preceding the screening (4.3 +/- 3.1 hours/week respectively 3.6 +/- 2.5 hours/week). The range of maximal values for power output (Wmax), heart rate (HRmax), systolic blood pressure (SBPmax) and peak plasma lactate concentrations (PPLa) during progressive cycle ergometer testing are presented for males and females who were divided into groups with a 5-years age difference. Wmax varied with sex (male = 1, female = 0), age (year) and height (cm); Wmax = 65.3 x (sex) + 2.0 x (height) -1.9 x (age) - 67.9 (See = 38.2; r = 0.76). The weighing of different factors that influence performance was also studied by multiple regression analysis to provide improved precision in standards used to interpret exercise tests. In both men and women about half of the variation of Wmax could be explained by the independent variables age, body mass, body fat, smoking habits, vital capacity, heart rate, and physical activity parameters. It is concluded that active involvement in endurance sports and/or the use of the bicycle for transport, contributed substantially to cardiovascular fitness in healthy, middle-aged men and women.

Power Converters Maximize Outputs Of Solar Cell Strings

NASA Technical Reports Server (NTRS)

Frederick, Martin E.; Jermakian, Joel B.

1993-01-01

Microprocessor-controlled dc-to-dc power converters devised to maximize power transferred from solar photovoltaic strings to storage batteries and other electrical loads. Converters help in utilizing large solar photovoltaic arrays most effectively with respect to cost, size, and weight. Main points of invention are: single controller used to control and optimize any number of "dumb" tracker units and strings independently; power maximized out of converters; and controller in system is microprocessor.

Effect of micromolar Ca2+ on NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex and possible role of Ca2+ in signal amplification.

PubMed

Lawlis, V B; Roche, T E

1980-11-20

NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex was compared at 10 microM free Ca2+ or in the absence of Ca2+ (i.e., less than 1.0 nM free Ca2+). In the presence of Ca2+, NADH inhibition was appreciably decreased for a wide range of NADH:NAD+ ratios. A half-maximal decrease in NADH inhibition occurred at slightly less than 1 microM free Ca/+ (as determined with EGTA-Ca buffers). Of necessity this was observed on top of an effect of Ca2+ on the S0.5 for alpha-ketoglutarate which was decreased by Ca2+ with a half-maximal effect at a similar concentration. The effect of Ca2+ on NADH inhibition was not observed in assays of the dihydrolipoyl dehydrogenase component (using dihydrolipoamide as a substrate) or in assays of bovine kidney pyruvate dehydrogenase complex. This indicates that the overall reaction catalyzed by the alpha-ketoglutarate dehydrogenase complex is required to elicit the effect of Ca2+ on NADH inhibition. At a fixed alpha-ketoglutarate concentration (50 microM), removal of Ca2+ reduced the activity of the alpha-ketoglutarate dehydrogenase complex by 8.5-fold (due to an increase in S0.5 for alpha-ketoglutarate) and, in the presence of different NADH:NAD+ ratios, decreased the activity of the complex by 50 to 100-fold. Effects of the phosphate potential (ATP/ADPxPi) or a combination of the phosphate potential and NADH:NAD+ ratio are also described. The possibility that the level of intramitochondrial free Ca/+ serves as a signal amplifier normally coupled to the energy state of mitochondria is discussed.

Influence of variable resistance loading on subsequent free weight maximal back squat performance.

PubMed

Mina, Minas A; Blazevich, Anthony J; Giakas, Giannis; Kay, Anthony D

2014-10-01

The purpose of the study was to determine the potentiating effects of variable resistance (VR) exercise during a warm-up on subsequent free-weight resistance (FWR) maximal squat performance. In the first session, 16 recreationally active men (age = 26.0 ± 7.8 years; height = 1.7 ± 0.2 m; mass = 82.6 ± 12.7 kg) were familiarized with the experimental protocols and tested for 1 repetition maximum (1RM) squat lift. The subjects then visited the laboratory on 2 further occasions under either control or experimental conditions. During these conditions, 2 sets of 3 repetitions of either FWR (control) or VR (experimental) squat lifts at 85% of 1RM were performed; during the experimental condition, 35% of the load was generated from band tension. After a 5-minute rest, 1RM, 3D knee joint kinematics, and vastus medialis, vastus lateralis, rectus femoris, and semitendinosus electromyogram (EMG) signals were recorded simultaneously. No subject increased 1RM after FWR, however, 13 of 16 (81%) subjects increased 1RM after VR (mean = 7.7%; p < 0.01). Lower peak and mean eccentric (16-19%; p ≤ 0.05) and concentric (12-21%; p ≤ 0.05) knee angular velocities were observed during the 1RM following VR when compared with FWR, however, no differences in knee flexion angle (1.8°; p > 0.05) or EMG amplitudes (mean = 5.9%; p > 0.05) occurred. Preconditioning using VR significantly increased 1RM without detectable changes in knee extensor muscle activity or knee flexion angle, although eccentric and concentric velocities were reduced. Thus, VR seems to potentiate the neuromuscular system to enhance subsequent maximal lifting performance. Athletes could thus use VR during warm-up routines to maximize squat performance.

Weak overturning circulation and increased iron fertilization maximized carbon storage in the glacial ocean

NASA Astrophysics Data System (ADS)

Muglia, J.; Skinner, L.; Schmittner, A.

2017-12-01

Circulation changes have been suggested to play an important role in the sequestration of atmospheric CO2 in the glacial ocean. However, previous studies have resulted in contradictory results regarding the strength of the Atlantic Meridional Overturning Circulation (AMOC) and three-dimensional, quantitative reconstructions of the glacial ocean constrained by multiple proxies remain lacking. Here we simulate the modern and glacial ocean using a coupled, global, three-dimensional, physical-biogeochemical model constrained simultaneously by d13C, radiocarbon, and d15N to explore the effects of AMOC differences and Southern Ocean iron fertilization on the distributions of these isotopes and ocean carbon storage. We show that d13C and radiocarbon data sparsely sampled at the locations of existing glacial sediment cores can be used to reconstruct the modern AMOC accurately. Applying this method to the glacial ocean we find that a surprisingly weak (6-9 Sv or about half of today's) and shallow AMOC maximizes carbon storage and best reproduces the sediment data. Increasing the atmospheric soluble iron flux in the model's Southern Ocean intensifies export production, carbon storage, and improves agreement with d13C and d15N reconstructions. Our best fitting model is a significant improvement compared with previous studies. It suggests that a weak and shallow AMOC and enhanced iron fertilization conspired to maximize carbon storage in the glacial ocean.

Short-term effect of ammonia concentration and salinity on activity of ammonia oxidizing bacteria.

PubMed

Claros, J; Jiménez, E; Borrás, L; Aguado, D; Seco, A; Ferrer, J; Serralta, J

2010-01-01

A continuously aerated SHARON (single reactor high activity ammonia removal over nitrite) system has been operated to achieve partial nitritation. Two sets of batch experiments were carried out to study the effect of ammonia concentration and salinity on the activity of ammonia-oxidizing bacteria (AOB). Activity of AOB raised as free ammonia concentration was increased reaching its maximum value at 4.5 mg NH3-N l(-1). The half saturation constant for free ammonia was determined (K(NH3)=0.32 mg NH3-N l(-1)). Activity decreased at TAN (total ammonium-nitrogen) concentration over 2,000 mg NH4-N l(-1). No free ammonia inhibition was detected. The effect of salinity was studied by adding different concentrations of different salts to the biomass. No significant differences were observed between the experiments carried out with a salt containing or not containing NH4. These results support that AOB are inhibited by salinity, not by free ammonia. A mathematical expression to represent this inhibition is proposed. To compare substrate affinity and salinity inhibitory effect on different AOB populations, similar experiments were carried out with biomass from a biological nutrient removal pilot plant. The AOB activity reached its maximum value at 0.008 mg NH3-N l(-1) and decreased at TAN concentration over 400 mg NH4-N l(-1). These differences can be explained by the different AOB predominating species: Nitrosomonas europaea and N. eutropha in the SHARON biomass and Nitrosomonas oligotropha in the pilot plant.

Occulting Light Concentrators in Liquid Scintillator Neutrino Detectors

NASA Astrophysics Data System (ADS)

Buizza Avanzini, Margherita; Cabrera, Anatael; Dusini, Stefano; Grassi, Marco; He, Miao; Wu, Wenjie

2017-09-01

The experimental efforts characterizing the era of precision neutrino physics revolve around collecting high-statistics neutrino samples and attaining an excellent energy and position resolution. Next generation liquid-based neutrino detectors, such as JUNO, HyperKamiokande, etc, share the use of a large target mass, and the need of pushing light collection to the edge for maximal calorimetric information. Achieving high light collection implies considerable costs, especially when considering detector masses of several kt. A traditional strategy to maximize the effective photo-coverage with the minimum number of PMTs relies on Light Concentrators (LC), such as Winston Cones. In this paper, the authors introduce a novel concept called Occulting Light Concentrators (OLC), whereby a traditional LC gets tailored to a conventional PMT, by taking into account its single-photoelectron collection efficiency profile and thus occulting the worst performing portion of the photocathode. Thus, the OLC shape optimization takes into account not only the optical interface of the PMT, but also the maximization of the PMT detection performances. The light collection uniformity across the detector is another advantage of the OLC system. By considering the case of JUNO, we will show OLC capabilities in terms of light collection and energy resolution.

Comparison between the clot-protecting activity of a mutant plasminogen activator inhibitor-1 with a very long half-life and 6-aminocaproic acid.

PubMed

Kindell, Daniel Glenn; Keck, Rick Wayne; Jankun, Jerzy

2015-06-01

Plasminogen activator inhibitor (PAI)-1 is a serpin glycoprotein that can stabilize blood clots by inhibiting fibrinolysis. However, wild-type PAI-1 has the disadvantage of a short half-life of ∼2 h. A very long half-life (VLHL) PAI-1 mutant was developed previously with an active-form half-life of >700 h, making it a possible candidate for use in hemorrhagic therapy. Current treatments for mitigating hemorrhage, other than inducers of blood clotting, are limited to lysine analog antifibrinolytics, including 6-aminocaproic acid and tranexamic acid. VLHL PAI-1 has been previously demonstrated to limit bleeding; however, the efficacy of this protein compared with lysine analog antifibrinolytics has not been investigated. The aim of the current study was to compare the clot stabilizing properties of the novel antifibrinolytic VLHL PAI-1 with those of 6-aminocaproic acid in reference plasma. Using thromboelastographic analysis, VLHL PAI-1 exhibited an IC 50 (half maximal inhibitory concentration) of 8.8×10 -8 mol/l, while 6-aminocaproic acid showed an IC 50 of 1.6×10 -4 mol/l. However, at doses of >9.0×10 -7 mol/l, VLHL PAI-1 exhibited a delay in the onset of clot formation, which may be attributed to thrombin inhibition by excess PAI-1. The inhibition of tissue plasminogen activator by VLHL PAI-1 demonstrated improved efficacy over 6-aminocaproic acid in mitigating hemorrhage. In addition, patients with a PAI-1 deficiency, which causes blood clots to lyse rapidly resulting in profuse bleeding, may benefit from the application of VLHL PAI-1 as an antihemorrhagic therapy.

Comparison between the clot-protecting activity of a mutant plasminogen activator inhibitor-1 with a very long half-life and 6-aminocaproic acid

PubMed Central

KINDELL, DANIEL GLENN; KECK, RICK WAYNE; JANKUN, JERZY

2015-01-01

Plasminogen activator inhibitor (PAI)-1 is a serpin glycoprotein that can stabilize blood clots by inhibiting fibrinolysis. However, wild-type PAI-1 has the disadvantage of a short half-life of ∼2 h. A very long half-life (VLHL) PAI-1 mutant was developed previously with an active-form half-life of >700 h, making it a possible candidate for use in hemorrhagic therapy. Current treatments for mitigating hemorrhage, other than inducers of blood clotting, are limited to lysine analog antifibrinolytics, including 6-aminocaproic acid and tranexamic acid. VLHL PAI-1 has been previously demonstrated to limit bleeding; however, the efficacy of this protein compared with lysine analog antifibrinolytics has not been investigated. The aim of the current study was to compare the clot stabilizing properties of the novel antifibrinolytic VLHL PAI-1 with those of 6-aminocaproic acid in reference plasma. Using thromboelastographic analysis, VLHL PAI-1 exhibited an IC50 (half maximal inhibitory concentration) of 8.8×10−8 mol/l, while 6-aminocaproic acid showed an IC50 of 1.6×10−4 mol/l. However, at doses of >9.0×10−7 mol/l, VLHL PAI-1 exhibited a delay in the onset of clot formation, which may be attributed to thrombin inhibition by excess PAI-1. The inhibition of tissue plasminogen activator by VLHL PAI-1 demonstrated improved efficacy over 6-aminocaproic acid in mitigating hemorrhage. In addition, patients with a PAI-1 deficiency, which causes blood clots to lyse rapidly resulting in profuse bleeding, may benefit from the application of VLHL PAI-1 as an antihemorrhagic therapy. PMID:26136983

Effect of red bull energy drink on auditory reaction time and maximal voluntary contraction.

PubMed

Goel, Vartika; Manjunatha, S; Pai, Kirtana M

2014-01-01

The use of "Energy Drinks" (ED) is increasing in India. Students specially use these drinks to rejuvenate after strenuous exercises or as a stimulant during exam times. The most common ingredient in EDs is caffeine and a popular ED available and commonly used is Red Bull, containing 80 mg of caffeine in 250 ml bottle. The primary aim of this study was to investigate the effects of Red Bull energy drink on Auditory reaction time and Maximal voluntary contraction. A homogeneous group containing twenty medical students (10 males, 10 females) participated in a crossover study in which they were randomized to supplement with Red Bull (2 mg/kg body weight of caffeine) or isoenergetic isovolumetric noncaffeinated control drink (a combination of Appy Fizz, Cranberry juice and soda) separated by 7 days. Maximal voluntary contraction (MVC) was recorded as the highest of the 3 values of maximal isometric force generated from the dominant hand using hand grip dynamometer (Biopac systems). Auditory reaction time (ART) was the average of 10 values of the time interval between the click sound and response by pressing the push button using hand held switch (Biopac systems). The energy and control drinks after one hour of consumption significantly reduced the Auditory reaction time in males (ED 232 ± 59 Vs 204 ± 34 s and Control 223 ± 57 Vs 210 ± 51 s; p < 0.05) as well as in females (ED 227 ± 56 Vs 214 ± 48 s and Control 224 ± 45 Vs 215 ± 36 s; p < 0.05) but had no effect on MVC in either sex (males ED 381 ± 37 Vs 371 ± 36 and Control 375 ± 61 Vs 363 ± 36 Newton, females ED 227 ± 23 Vs 227 ± 32 and Control 234 ± 46 Vs 228 ± 37 Newton). When compared across the gender groups, there was no significant difference between males and females in the effects of any of the drinks on the ART but there was an overall significantly lower MVC in females compared to males. Both energy drink and the control drink significantly improve the reaction time but may not have any effect

Interference effects in phased beam tracing using exact half-space solutions.

PubMed

Boucher, Matthew A; Pluymers, Bert; Desmet, Wim

2016-12-01

Geometrical acoustics provides a correct solution to the wave equation for rectangular rooms with rigid boundaries and is an accurate approximation at high frequencies with nearly hard walls. When interference effects are important, phased geometrical acoustics is employed in order to account for phase shifts due to propagation and reflection. Error increases, however, with more absorption, complex impedance values, grazing incidence, smaller volumes and lower frequencies. Replacing the plane wave reflection coefficient with a spherical one reduces the error but results in slower convergence. Frequency-dependent stopping criteria are then applied to avoid calculating higher order reflections for frequencies that have already converged. Exact half-space solutions are used to derive two additional spherical wave reflection coefficients: (i) the Sommerfeld integral, consisting of a plane wave decomposition of a point source and (ii) a line of image sources located at complex coordinates. Phased beam tracing using exact half-space solutions agrees well with the finite element method for rectangular rooms with absorbing boundaries, at low frequencies and for rooms with different aspect ratios. Results are accurate even for long source-to-receiver distances. Finally, the crossover frequency between the plane and spherical wave reflection coefficients is discussed.

On the Relationship between Maximal Reliability and Maximal Validity of Linear Composites

ERIC Educational Resources Information Center

Penev, Spiridon; Raykov, Tenko

2006-01-01

A linear combination of a set of measures is often sought as an overall score summarizing subject performance. The weights in this composite can be selected to maximize its reliability or to maximize its validity, and the optimal choice of weights is in general not the same for these two optimality criteria. We explore several relationships…

Maximizing and minimizing investment concentration with constraints of budget and investment risk

NASA Astrophysics Data System (ADS)

Shinzato, Takashi

2018-01-01

In this paper, as a first step in examining the properties of a feasible portfolio subset that is characterized by budget and risk constraints, we assess the maximum and minimum of the investment concentration using replica analysis. To do this, we apply an analytical approach of statistical mechanics. We note that the optimization problem considered in this paper is the dual problem of the portfolio optimization problem discussed in the literature, and we verify that these optimal solutions are also dual. We also present numerical experiments, in which we use the method of steepest descent that is based on Lagrange's method of undetermined multipliers, and we compare the numerical results to those obtained by replica analysis in order to assess the effectiveness of our proposed approach.

Comparison of the effects of maximal dose atorvastatin and rosuvastatin therapy on cholesterol synthesis and absorption markers

USDA-ARS?s Scientific Manuscript database

We measured plasma markers of cholesterol synthesis (lathosterol) and absorption (campesterol, sitosterol, and cholestanol) in order to compare the effects of maximal doses of rosuvastatin with atorvastatin and investigate the basis for the significant individual variation in lipid lowering response...

[Effect of psychotropic drugs on activity of anticonvulsants in maximal electroshock test].

PubMed

Alikina, N A; Tregubov, A L; Kotegov, V P

2010-08-01

The effect ofpsychotropic drugs on the pharmacological properties of anticonvulsants was studied on white mice under maximal electroshock (ME) test conditions. Changes in the anticonvulsant effect of phenobarbital, diphenin, carbamazepine, hexamidine were traced upon their joint administration with psychotropic drugs, including piracetam, aminalon, amitriptyline, imizine, levomepromazine, and lithium oxybutyrate. An important result of research is the fact, that in no one of combinations the basic pharmacological effect of anticonvulsants was decreased. Based on the results of experiments, the most rational combinations of anticonvulsants with psychotropic preparations were revealed as manifested in the ME test. As criterion of rational combination was the increase in the activity of anticonvulsants and reduction of their toxicity in combination or at least invariance of this parameter. Rational combinations include (i) phenobarbital with piracetam, amitriptyline, levomepromazine, and lithium oxybutyrate; (ii) carbamazepine with piracetam; and (iii) hexamidine with amitriptyline, levomepromazine and imizine.

The cytochrome P4503A4 inhibitor clarithromycin increases the plasma concentrations and effects of repaglinide.

PubMed

Niemi, M; Neuvonen, P J; Kivistö, K T

2001-07-01

Our objective was to study the effects of the macrolide antibiotic clarithromycin on the pharmacokinetics and pharmacodynamics of repaglinide, a novel short-acting antidiabetic drug. In a randomized, double-blind, 2-phase crossover study, 9 healthy volunteers were treated for 4 days with 250 mg oral clarithromycin or placebo twice daily. On day 5 they received a single dose of 250 mg clarithromycin or placebo, and 1 hour later a single dose of 0.25 mg repaglinide was given orally. Plasma repaglinide, serum insulin, and blood glucose concentrations were measured up to 7 hours. Clarithromycin increased the mean total area under the concentration-time curve of repaglinide by 40% (P <.0001) and the peak plasma concentration by 67% (P <.005) compared with placebo. The mean elimination half-life of repaglinide was prolonged from 1.4 to 1.7 hours (P <.05) by clarithromycin. Clarithromycin increased the mean incremental area under the concentration-time curve from 0 to 3 hours of serum insulin by 51% (P <.05) and the maximum increase in the serum insulin concentration by 61% (P <.01) compared with placebo. No statistically significant differences were found in the blood glucose concentrations between the placebo and clarithromycin phases. Even low doses of the cytochrome P4503A4 (CYP3A4) inhibitor clarithromycin increase the plasma concentrations and effects of repaglinide. Concomitant use of clarithromycin or other potent inhibitors of CYP3A4 with repaglinide may enhance its blood glucose-lowering effect and increase the risk of hypoglycemia.

Effects of breathing frequency and flow rate on the total inward leakage of an elastomeric half-mask donned on an advanced manikin headform.

PubMed

He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; McKay, Roy; Bergman, Michael S; Zhuang, Ziqing

2014-03-01

The objective of this study was to investigate the effects of breathing frequency and flow rate on the total inward leakage (TIL) of an elastomeric half-mask donned on an advanced manikin headform and challenged with combustion aerosols. An elastomeric half-mask respirator equipped with P100 filters was donned on an advanced manikin headform covered with life-like soft skin and challenged with aerosols originated by burning three materials: wood, paper, and plastic (polyethylene). TIL was determined as the ratio of aerosol concentrations inside (C in) and outside (C out) of the respirator (C in/C out) measured with a nanoparticle spectrometer operating in the particle size range of 20-200nm. The testing was performed under three cyclic breathing flows [mean inspiratory flow (MIF) of 30, 55, and 85 l/min] and five breathing frequencies (10, 15, 20, 25, and 30 breaths/min). A completely randomized factorial study design was chosen with four replicates for each combination of breathing flow rate and frequency. Particle size, MIF, and combustion material had significant (P < 0.001) effects on TIL regardless of breathing frequency. Increasing breathing flow decreased TIL. Testing with plastic aerosol produced higher mean TIL values than wood and paper aerosols. The effect of the breathing frequency was complex. When analyzed using all combustion aerosols and MIFs (pooled data), breathing frequency did not significantly (P = 0.08) affect TIL. However, once the data were stratified according to combustion aerosol and MIF, the effect of breathing frequency became significant (P < 0.05) for all MIFs challenged with wood and paper combustion aerosols, and for MIF = 30 l/min only when challenged with plastic combustion aerosol. The effect of breathing frequency on TIL is less significant than the effects of combustion aerosol and breathing flow rate for the tested elastomeric half-mask respirator. The greatest TIL occurred when challenged with plastic aerosol at 30 l/min and

Does evolution lead to maximizing behavior?

PubMed

Lehmann, Laurent; Alger, Ingela; Weibull, Jörgen

2015-07-01

A long-standing question in biology and economics is whether individual organisms evolve to behave as if they were striving to maximize some goal function. We here formalize this "as if" question in a patch-structured population in which individuals obtain material payoffs from (perhaps very complex multimove) social interactions. These material payoffs determine personal fitness and, ultimately, invasion fitness. We ask whether individuals in uninvadable population states will appear to be maximizing conventional goal functions (with population-structure coefficients exogenous to the individual's behavior), when what is really being maximized is invasion fitness at the genetic level. We reach two broad conclusions. First, no simple and general individual-centered goal function emerges from the analysis. This stems from the fact that invasion fitness is a gene-centered multigenerational measure of evolutionary success. Second, when selection is weak, all multigenerational effects of selection can be summarized in a neutral type-distribution quantifying identity-by-descent between individuals within patches. Individuals then behave as if they were striving to maximize a weighted sum of material payoffs (own and others). At an uninvadable state it is as if individuals would freely choose their actions and play a Nash equilibrium of a game with a goal function that combines self-interest (own material payoff), group interest (group material payoff if everyone does the same), and local rivalry (material payoff differences). © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

The effective and environmental half-life of 137Cs at Coral Islands at the former US nuclear test site.

PubMed

Robison, William L; Conrado, Cynthia L; Bogen, Kenneth T; Stoker, A Carol

2003-01-01

The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the 137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr

Consistency of peak and mean concentric and eccentric force using a novel squat testing device.

PubMed

Stock, Matt S; Luera, Micheal J

2014-04-01

The ability to examine force curves from multiple-joint assessments combines many of the benefits of dynamic constant external resistance exercise and isokinetic dynamometry. The purpose of this investigation was to examine test-retest reliability statistics for peak and mean force using the Exerbotics eSQ during maximal concentric and eccentric squats. Seventeen resistance-trained men (mean±SD age=21±2 years) visited the laboratory on two occasions. For each trial, the subjects performed two maximal concentric and eccentric squats, and the muscle actions with the highest force values were analyzed. There were no mean differences between the trials (P>.05), and the effect sizes were <0.12. When the entire force curve was examined, the intraclass correlation coefficients (model 2,1) and standard errors of measurement, respectively, were concentric peak force=0.743 (8.8%); concentric mean force=0.804 (6.0%); eccentric peak force=0.696 (10.6%); eccentric mean force=0.736 (9.6%). These findings indicated moderate-to-high reliability for the peak and mean force values obtained from the Exerbotics eSQ during maximal squat testing. The analysis of force curves from multiple-joint testing provides researchers and practitioners with a reliable means of assessing performance, especially during concentric muscle actions.

Validation of Different Combination of Three Reversing Half-Hitches Alternating Posts (RHAPs) Effects on Arthroscopic Knot Integrity.

PubMed

Chong, Alexander Cm; Prohaska, Daniel J; Bye, Brian P

2017-05-01

With arthroscopic techniques being used, the importance of knot tying has been examined. Previous literature has examined the use of reversing half-hitches on alternating posts (RHAPs) on knot security. Separately, there has been research regarding different suture materials commonly used in the operating room. The specific aim of this study was to validate the effect of different stacked half-hitch configuration and different braided suture materials on arthroscopic knot integrity. Three different suture materials tied with five different RHAPs in arthroscopic knots were compared. A single load-to-failure test was performed and the mean ultimate clinical failure load was obtained. Significant knot holding strength improvement was found when one half-hitch was reversed as compared to baseline knot. When two of the half-hitches were reversed, there was a greater improvement with all knots having a mean ultimate clinical failure load greater than 150 newtons (N). Comparison of the suture materials demonstrated a higher mean ultimate clinical failure load when Force Fiber ® was used and at least one half-hitch was reversed. Knots tied with either Force Fiber ® or Orthocord ® showed 0% chance of knot slippage while knots tied with FiberWire ® or braided fishing line had about 10 and 30% knot slippage chances, respectively. A significant effect was observed in regards to both stacked half-hitch configuration and suture materials used on knot loop and knot security. Caution should be used with tying three RHAPs in arthroscopic surgery, particularly with a standard knot pusher and arthroscopic cannulas. The findings of this study indicated the importance of three RHAPs in performing arthroscopic knot tying and provided evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons, thereby leading to better surgical outcomes in the future.

Carnot cycle at finite power: attainability of maximal efficiency.

PubMed

Allahverdyan, Armen E; Hovhannisyan, Karen V; Melkikh, Alexey V; Gevorkian, Sasun G

2013-08-02

We want to understand whether and to what extent the maximal (Carnot) efficiency for heat engines can be reached at a finite power. To this end we generalize the Carnot cycle so that it is not restricted to slow processes. We show that for realistic (i.e., not purposefully designed) engine-bath interactions, the work-optimal engine performing the generalized cycle close to the maximal efficiency has a long cycle time and hence vanishing power. This aspect is shown to relate to the theory of computational complexity. A physical manifestation of the same effect is Levinthal's paradox in the protein folding problem. The resolution of this paradox for realistic proteins allows to construct engines that can extract at a finite power 40% of the maximally possible work reaching 90% of the maximal efficiency. For purposefully designed engine-bath interactions, the Carnot efficiency is achievable at a large power.

Two-step entanglement concentration for arbitrary electronic cluster state

NASA Astrophysics Data System (ADS)

Zhao, Sheng-Yang; Liu, Jiong; Zhou, Lan; Sheng, Yu-Bo

2013-12-01

We present an efficient protocol for concentrating an arbitrary four-electron less-entangled cluster state into a maximally entangled cluster state. As a two-step entanglement concentration protocol (ECP), it only needs one pair of less-entangled cluster state, which makes this ECP more economical. With the help of electronic polarization beam splitter (PBS) and the charge detection, the whole concentration process is essentially the quantum nondemolition (QND) measurement. Therefore, the concentrated maximally entangled state can be remained for further application. Moreover, the discarded terms in some traditional ECPs can be reused to obtain a high success probability. It is feasible and useful in current one-way quantum computation.

Understanding the factors that effect maximal fat oxidation.

PubMed

Purdom, Troy; Kravitz, Len; Dokladny, Karol; Mermier, Christine

2018-01-01

Lipids as a fuel source for energy supply during submaximal exercise originate from subcutaneous adipose tissue derived fatty acids (FA), intramuscular triacylglycerides (IMTG), cholesterol and dietary fat. These sources of fat contribute to fatty acid oxidation (FAox) in various ways. The regulation and utilization of FAs in a maximal capacity occur primarily at exercise intensities between 45 and 65% VO 2max , is known as maximal fat oxidation (MFO), and is measured in g/min. Fatty acid oxidation occurs during submaximal exercise intensities, but is also complimentary to carbohydrate oxidation (CHOox). Due to limitations within FA transport across the cell and mitochondrial membranes, FAox is limited at higher exercise intensities. The point at which FAox reaches maximum and begins to decline is referred to as the crossover point. Exercise intensities that exceed the crossover point (~65% VO 2max ) utilize CHO as the predominant fuel source for energy supply. Training status, exercise intensity, exercise duration, sex differences, and nutrition have all been shown to affect cellular expression responsible for FAox rate. Each stimulus affects the process of FAox differently, resulting in specific adaptions that influence endurance exercise performance. Endurance training, specifically long duration (>2 h) facilitate adaptations that alter both the origin of FAs and FAox rate. Additionally, the influence of sex and nutrition on FAox are discussed. Finally, the role of FAox in the improvement of performance during endurance training is discussed.

Effective Educational Videos: Principles and Guidelines for Maximizing Student Learning from Video Content

PubMed Central

Brame, Cynthia J.

2016-01-01

Educational videos have become an important part of higher education, providing an important content-delivery tool in many flipped, blended, and online classes. Effective use of video as an educational tool is enhanced when instructors consider three elements: how to manage cognitive load of the video; how to maximize student engagement with the video; and how to promote active learning from the video. This essay reviews literature relevant to each of these principles and suggests practical ways instructors can use these principles when using video as an educational tool. PMID:27789532

Effect of antiischemic therapy on coronary flow reserve and the pressure-maximal coronary flow relationship in anesthetized swine.

PubMed

McFalls, E O; Duncker, D J; Sassen, L M; Gho, B C; Verdouw, P D

1991-12-01

The effect of nifedipine (0.5, 1.0, and 2.0 micrograms/kg/min), metoprolol (0.1, 0.5, and 1.0 mg/kg), the beta 1-selective adrenoceptor partial agonist epanolol (10, 50, and 200 micrograms/kg), or equivalent volumes of isotonic saline (n = 6, in each group), on coronary blood flow capacity were studied in anesthetized swine. Intracoronary bolus injections of adenosine (20 micrograms/kg/0.2 ml) were administered without and during three levels of coronary stenosis, prior to and following each dose of drug, to obtain maximal coronary blood flows at different perfusion pressures in the autoregulatory range. Coronary perfusion pressures were varied by partial inflation of a balloon around the left anterior descending coronary artery. Special care was taken that the stenoses not lead to myocardial ischemia. Three indices of coronary blood flow capacity were used: absolute coronary flow reserve (ACFR, the ratio of maximal to resting coronary blood flow), the slope and the extrapolated pressure at zero flow (Pzf) of the pressure-maximal coronary flow (PMCF) relationship, and relative coronary flow reserve (RCFR, the ratio of maximal coronary blood flow with a stenosis to maximal coronary blood flow without a stenosis) at two of the three levels of stenosis. Nifedipine decreased ACFR from 4.5 +/- 1.9 to 1.9 +/- 0.3 (mean +/- SD; p less than 0.05), reflecting in part the increase in resting coronary blood flow. The nifedipine-induced changes in maximal coronary blood flow were not only due to a drop in perfusion pressure, as the slope of the PMCF relationship decreased from 2.27 +/- 0.49 ml/(min.mm Hg) to 1.54 +/- 0.51 ml/(min.mm Hg) (p less than 0.05), and Pzf decreased from 30 +/- 4 mm Hg to 20 +/- 7 mm Hg (p less than 0.05). Consequently, calculated maximal coronary blood flow was attenuated from 114 +/- 31 ml/min to 93 +/- 37 ml/min at 80 mm Hg, but was enhanced from 23 +/- 13 to 37 +/- 24 ml/min at 40 mm Hg coronary perfusion pressure. In concert with the change in the

Estrone and 17beta-estradiol concentrations in pasteurized-homogenized milk and commercial dairy products.

PubMed

Pape-Zambito, D A; Roberts, R F; Kensinger, R S

2010-06-01

Some individuals fear that estrogens in dairy products may stimulate growth of estrogen-sensitive cancers in humans. The presence of estrone (E(1)) and 17beta-estradiol (E(2)) in raw whole cow's milk has been demonstrated. The objectives of this study were to determine if pasteurization-homogenization affects E(2) concentration in milk and to quantify E(1) and E(2) concentrations in commercially available dairy products. The effects of pasteurization-homogenization were tested by collecting fresh raw milk, followed by pasteurization and homogenization at 1 of 2 homogenization pressures. All treated milks were tested for milk fat globule size, percentages of milk fat and solids, and E(2) concentrations. Estrone and E(2) were quantified from organic or conventional skim, 1%, 2%, and whole milks, as well as half-and-half, cream, and butter samples. Estrone and E(2) were quantified by RIA after organic solvent extractions and chromatography. Pasteurization-homogenization reduced fat globule size, but did not significantly affect E(2), milk fat, or milk solids concentrations. Estrone concentrations averaged 2.9, 4.2, 5.7, 7.9, 20.4, 54.1 pg/mL, and 118.9 pg/g in skim, 1%, 2%, and whole milks, half-and-half, cream, and butter samples, respectively. 17Beta-estradiol concentrations averaged 0.4, 0.6, 0.9, 1.1, 1.9, 6.0 pg/mL, and 15.8 pg/g in skim, 1%, 2%, whole milks, half-and-half, cream, and butter samples, respectively. The amount of fat in milk significantly affected E(1) and E(2) concentrations in milk. Organic and conventional dairy products did not have substantially different concentrations of E(1) and E(2). Compared with information cited in the literature, concentrations of E(1) and E(2) in bovine milk are small relative to endogenous production rates of E(1) and E(2) in humans. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Gemfibrozil markedly increases the plasma concentrations of montelukast: a previously unrecognized role for CYP2C8 in the metabolism of montelukast.

PubMed

Karonen, T; Filppula, A; Laitila, J; Niemi, M; Neuvonen, P J; Backman, J T

2010-08-01

According to available information, montelukast is metabolized by cytochrome P450 (CYP) 3A4 and 2C9. In order to study the significance of CYP2C8 in the pharmacokinetics of montelukast, 10 healthy subjects were administered gemfibrozil 600 mg or placebo twice daily for 3 days, and 10 mg montelukast on day 3, in a randomized, crossover study. Gemfibrozil increased the mean area under the plasma concentration-time curve (AUC)(0-infinity), peak plasma concentration (C(max)), and elimination half-life (t(1/2)) of montelukast 4.5-fold, 1.5-fold, and 3.0-fold, respectively (P < 0.001). After administration of gemfibrozil, the time to reach C(max) (t(max)) of the montelukast metabolite M6 was prolonged threefold (P = 0.005), its AUC(0-7) was reduced by 40% (P = 0.027), and the AUC(0-24) of the secondary metabolite M4 was reduced by >90% (P < 0.001). In human liver microsomes, gemfibrozil 1-O-beta glucuronide inhibited the formation of M6 (but not of M5) from montelukast 35-fold more potently than did gemfibrozil (half-maximal inhibitory concentration (IC(50)) 3.0 and 107 micromol/l, respectively). In conclusion, gemfibrozil markedly increases the plasma concentrations of montelukast, indicating that CYP2C8 is crucial in the elimination of montelukast.

Effects of High and Low Salt Concentration in Electrolytes at Lithium–Metal Anode Surfaces

DOE PAGES

Camacho-Forero, Luis E.; Smith, Taylor W.; Balbuena, Perla B.

2016-12-16

The use of high concentration salts in electrolyte solutions of lithium-sulfur (Li-S) batteries has been shown beneficial for mitigating some effects such as polysulfide shuttle and dendrite growth at the Li metal anode. Such complex solutions have structural, dynamical, and reactivity associated issues that need to be analyzed for a better understanding of the reasons behind such beneficial effects. A passivation interfacial layer known as solid-electrolyte interphase (SEI) is generated during battery cycling as a result of electron transfer from the metal anode causing electrolyte decomposition. Here in this work, we investigate using density functional theory and ab initio molecularmore » dynamics simulations the salt decomposition, solvation effects, interactions among intermediate products and other species, and potential components of the SEI layer as a function of chemical nature and concentration of the salt, for lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(fluorosulfonyl)imide (LiFSI) at 1M and 4M concentrations in dimethoxyethane. It is found that LiTFSI undergoes a less complete reduction and facilitates charge transfer from the anode, whereas LiFSI shows a more complete decomposition forming LiF as one of the main SEI products. In addition, the specific decomposition mechanisms of each salt clearly point to the initial SEI components and the potential main products derived from them. Finally, very complex networks are found among the salt and solvent molecules in their attempt to maximize Li ion solvation that is quantified through the determination of coordination numbers.« less

Influence of adipocyte size and adipose depot on the in vitro lipolytic activity and insulin sensitivity of adipose tissue in dairy cows at the end of the dry period.

PubMed

De Koster, J; Van den Broeck, W; Hulpio, L; Claeys, E; Van Eetvelde, M; Hermans, K; Hostens, M; Fievez, V; Opsomer, G

2016-03-01

The aim of the present research was to describe characteristics of adipose tissue lipolysis in dairy cows with a variable body condition score (BCS). Ten clinically healthy Holstein Friesian cows were selected based on BCS and euthanized 10 to 13 d before the expected parturition date. Immediately after euthanasia, adipose tissue samples were collected from subcutaneous and omental fat depots. In both depots, we observed an increase in adipocyte size with increasing BCS. Using an in vitro explant culture of subcutaneous and omental adipose tissue, we aimed to determine the influence of adipocyte size and localization of adipose depot on the lipolytic activity in basal conditions and after addition of isoproterenol (nonselective β-agonist) and insulin in different concentrations. Glycerol release in the medium was used as a measure for lipolytic activity. We observed that the basal lipolytic activity of subcutaneous and omental adipose tissue increased with adipocyte volume, meaning that larger fat cells have higher basal lipolytic activity independent of the location of the adipose depot. Dose-response curves were created between the concentration of isoproterenol or insulin and the amount of glycerol released. The shape of the dose-response curves is determined by the concentration of isoproterenol and insulin needed to elicit the half-maximal effect and the maximal amount of stimulated glycerol release or the maximal inhibitory effect of insulin. We observed that larger fat cells released more glycerol upon maximal stimulation with isoproterenol and this was more pronounced in subcutaneous adipose tissue. Additionally, larger fat cells had a higher sensitivity toward lipolytic signals. We observed a trend for larger adipocytes to be more resistant to the maximal antilipolytic effect of insulin. The insulin concentration needed to elicit the half-maximal inhibitory effect of insulin was within the physiological range of insulin and was not influenced by adipocyte

A Model of College Tuition Maximization

ERIC Educational Resources Information Center

Bosshardt, Donald I.; Lichtenstein, Larry; Zaporowski, Mark P.

2009-01-01

This paper develops a series of models for optimal tuition pricing for private colleges and universities. The university is assumed to be a profit maximizing, price discriminating monopolist. The enrollment decision of student's is stochastic in nature. The university offers an effective tuition rate, comprised of stipulated tuition less financial…

Maximally multipartite entangled states

NASA Astrophysics Data System (ADS)

Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

2008-06-01

We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

Maximally Symmetric Composite Higgs Models.

PubMed

Csáki, Csaba; Ma, Teng; Shu, Jing

2017-09-29

Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.

A coupled system of half-nitritation and ANAMMOX for mature landfill leachate nitrogen removal.

PubMed

Li, Yun; Li, Jun; Zhao, Baihang; Wang, Xiujie; Zhang, Yanzhuo; Wei, Jia; Bian, Wei

2017-09-01

A coupled system of membrane bioreactor-nitritation (MBR-nitritation) and up-flow anaerobic sludge blanket-anaerobic ammonium oxidation (UASB-ANAMMOX) was employed to treat mature landfill leachate containing high ammonia nitrogen and low C/N. MBR-nitritation was successfully realized for undiluted mature landfill leachate with initial concentrations of 900-1500 mg/L [Formula: see text] and 2000-4000 mg/L chemical oxygen demand. The effluent [Formula: see text] concentration and the [Formula: see text] accumulation efficiency were 889 mg/L and 97% at 125 d, respectively. Half-nitritation was quickly realized by adjustment of hydraulic retention time and dissolved oxygen (DO), and a low DO control strategy could allow long-term stable operation. The UASB-ANAMMOX system showed high effective nitrogen removal at a low concentration of mature landfill leachate. The nitrogen removal efficiency was inhibited at excessive influent substrate concentration and the nitrogen removal efficiency of the system decreased as the concentration of mature landfill leachate increased. The MBR-nitritation and UASB-ANAMMOX processes were coupled for mature landfill leachate treatment and together resulted in high effective nitrogen removal. The effluent average total nitrogen concentration and removal efficiency values were 176 mg/L and 83%, respectively. However, the average nitrogen removal load decreased from 2.16 to 0.77 g/(L d) at higher concentrations of mature landfill leachate.

Low concentrator PV optics optimization

NASA Astrophysics Data System (ADS)

Sharp, Leonard; Chang, Ben

2008-08-01

Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

Protein kinase C may regulate the tonic component of intestinal smooth muscle contraction in response to substance P.

PubMed

Holzer, P; Lippe, I T

1989-01-01

(1) The study investigated a possible involvement of protein kinase C (PKC) in the substance P-induced contraction of the longitudinal muscle of the guinea-pig isolated ileum. (2) The predominant effect of the PKC activator, phorbol-12,13-dibutyrate (PDB), was to change the time course of the response to substance P. While the initial peak contraction was hardly influenced by PDB, the fading of the contraction was accelerated to an extent that any tonic contraction which normally followed the initial peak response was prevented. This inhibitory effect of PDB on the tonic contraction was immediate in onset and related to its concentration (20-200 nM); responses to half-maximally (2-7 nM) or maximally effective (0.74 microM) concentrations of substance P were affected in the same manner. Tetrodotoxin (0.6 microM) did not alter the effect of PDB. Phorbol-13-monoacetate (2 microM), a phorbol ester which does not stimulate PKC, failed to change the time course of the substance P-induced contraction. (3) The tonic component of half-maximal contractile responses to histamine (0.2-0.4 microM) was also depressed by PDB (0.2 microM) whereas the tonic component of maximal responses to histamine (9 microM) was enhanced. (4) PDB (0.2 microM) reduced desensitization to substance P as judged by the reduction of the peak response to substance P (2-7 nM) following a 10-min exposure to a high concentration of the peptide (0.74 microM). (5) The PKC inhibitor, polymyxin B (0.1-0.3 mM), reduced the peak contractile response to substance P, slowed the fading of the contraction, and antagonized the inhibitory effect of PDB on the tonic contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Resist image quality control via acid diffusion constant and/or photodecomposable quencher concentration in the fabrication of 11 nm half-pitch line-and-space patterns using extreme-ultraviolet lithography

NASA Astrophysics Data System (ADS)

Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

2018-05-01

Extreme-ultraviolet (EUV) lithography will be applied to the high-volume production of semiconductor devices with 16 nm half-pitch resolution and is expected to be extended to that of devices with 11 nm half-pitch resolution. With the reduction in the feature sizes, the control of acid diffusion becomes a significant concern. In this study, the dependence of resist image quality on T PEB D acid and photodecomposable quencher concentration was investigated by the Monte Carlo method on the basis of the sensitization and reaction mechanisms of chemically amplified EUV resists. Here, T PEB and D acid are the postexposure baking (PEB) time and the acid diffusion constant, respectively. The resist image quality of 11 nm line-and-space patterns is discussed in terms of line edge roughness (LER) and stochastic defect generation. For the minimization of LER, it is necessary to design and control not only the photodecomposable quencher concentration but also T PEB D acid. In this case, D acid should be adjusted to be 0.3–1.5 nm2 s‑1 for a PEB time of 60 s with optimization of the balance among LER and stochastic pinching and bridging. Even if it is difficult to decrease D acid to the range of 0.3–1.5 nm2 s‑1, the image quality can still be controlled via only the photodecomposable quencher concentration, although LER and stochastic pinching and bridging are slightly increased. In this case, accurate control of the photodecomposable quencher concentration and the reduction in the initial standard deviation of the number of protected units are required.

In vitro effects of acetylcholinesterase reactivators on monoamine oxidase activity.

PubMed

Fišar, Zdeněk; Hroudová, Jana; Korábečný, Jan; Musílek, Kamil; Kuča, Kamil

2011-03-05

Administration of acetylcholinesterase (AChE) reactivators (oximes) is usually used in order to counteract the poisoning effects of nerve agents. The possibility was suggested that oximes may show some therapeutic and/or adverse effects through their action in central nervous system. There are no sufficient data about interaction of oximes with monoaminergic neurotransmitter's systems in the brain. Oxime-type AChE reactivators pralidoxime, obidoxime, trimedoxime, methoxime and HI-6 were tested for their potential to affect the activity of monoamine oxidase of type A (MAO-A) and type B (MAO-B) in crude mitochondrial fraction of pig brains. The compounds were found to inhibit fully MAO-A with half maximal inhibitory concentration (IC(50)) of 0.375 mmol/l (pralidoxime), 1.53 mmol/l (HI-6), 2.31 mmol/l (methoxime), 2.42 mmol/l (obidoxime) and 4.98 mmol/l (trimedoxime). Activity of MAO-B was fully inhibited by HI-6 and pralidoxime only with IC(50) 4.81 mmol/l and 11.01 mmol/l, respectively. Methoxime, obidoxime and trimedoxime displayed non-monotonic concentration dependent effect on MAO-B activity. Because oximes concentrations effective for MAO inhibition could not be achieved in vivo at the cerebral level, we suppose that oximes investigated do not interfere with brain MAO at therapeutically relevant concentrations. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Effect of emulsion size and shelf life of azadirachtin A on the bioefficacy of neem (Azadirachta indica A. Juss) emulsifiable concentrates.

PubMed

Kumar, L; Parmar, B S

2000-08-01

In a study of 33 recipes of neem oil based emulsifiable concentrates, the specific surface area of the emulsions and cream plus oil layer separation in emulsions at 24 h revealed a correlation of -0.6874 between them and correlations of -0.8940 and 0.6972, respectively, with bioefficacy (LC(50)) against the 3-day-old second-instar larvae of the Bihar hairy caterpillar, Spilosoma obliqua Walker. Nearly 96-99% of azadirachtin A in emulsifiable concentrates (aza-A content = 617.93-1149.65 ppm) degraded during the heat stability test at 54 +/- 1 degrees C for 14 days with half-lives ranging between 1.84 and 4.53 days. The LC(50) values against S. obliqua were, however, statistically at par in both the pre- and the post-heat-treated samples, suggesting a similar effect of azadirachtin A and its degradation products on the bioactivity. The half-life of azadirachtin A could be enhanced by storing the concentrates at lower temperatures. A low pH of the formulation solvent did not check the degradation of azadirachtin A, as reported with aqueous solutions in the literature.

Cardiorespiratory Coordination in Repeated Maximal Exercise

PubMed Central

Garcia-Retortillo, Sergi; Javierre, Casimiro; Hristovski, Robert; Ventura, Josep L.; Balagué, Natàlia

2017-01-01

Increases in cardiorespiratory coordination (CRC) after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC) analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate) was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1) were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax), maximal oxygen consumption (VO2 max), or ventilatory threshold (VT), an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08) was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43) in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT) between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC evaluation in

Basic principles of maximizing dental office productivity.

PubMed

Mamoun, John

2012-01-01

To maximize office productivity, dentists should focus on performing tasks that only they can perform and not spend office hours performing tasks that can be delegated to non-dentist personnel. An important element of maximizing productivity is to arrange the schedule so that multiple patients are seated simultaneously in different operatories. Doing so allows the dentist to work on one patient in one operatory without needing to wait for local anesthetic to take effect on another patient in another operatory, or for assistants to perform tasks (such as cleaning up, taking radiographs, performing prophylaxis, or transporting and preparing equipment and supplies) in other operatories. Another way to improve productivity is to structure procedures so that fewer steps are needed to set up and implement them. In addition, during procedures, four-handed dental passing methods can be used to provide the dentist with supplies or equipment when needed. This article reviews basic principles of maximizing dental office productivity, based on the author's observations of business logistics used by various dental offices.

Maximal and submaximal endurance performance in adults with severe haemophilia.

PubMed

Herbsleb, M; Hilberg, T

2009-01-01

Maximal exercise testing, including the determination of maximal performance and maximal oxygen uptake (VO(2max)), is considered the gold standard for assessing maximal endurance performance. The effectiveness of such testing is often reduced in haemophilic adults owing to musculoskeletal impairments or pain rather than because of cardiac exertion. The measurement of submaximal performance parameters overcomes many limitations of maximal exercise testing but a testing standard is still lacking. The aim of this study was to investigate maximal and particularly submaximal endurance performance of adult patients with severe haemophilia A and B. Eleven patients and 11 matched healthy controls were tested by spiroergometry with a specific treadmill test and the power was calculated in Watts. The haemophilic group achieved lower absolute (210 +/- 63 W) and weight-related (2.94 +/- 0.98 W kg(-1)) maximal endurance performance compared with the control group (287 +/- 50 W resp. 3.82 +/- 0.53 W kg(-1); P maximal and submaximal endurance performance, which can be easily measured by the described test procedure.

Online Farsi digit recognition using their upper half structure

NASA Astrophysics Data System (ADS)

Ghods, Vahid; Sohrabi, Mohammad Karim

2015-03-01

In this paper, we investigated the efficiency of upper half Farsi numerical digit structure. In other words, half of data (upper half of the digit shapes) was exploited for the recognition of Farsi numerical digits. This method can be used for both offline and online recognition. Half of data is more effective in speed process, data transfer and in this application accuracy. Hidden Markov model (HMM) was used to classify online Farsi digits. Evaluation was performed by TMU dataset. This dataset contains more than 1200 samples of online handwritten Farsi digits. The proposed method yielded more accuracy in recognition rate.

Influence of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of various novel antiepileptic drugs against maximal electroshock-induced seizures in mice.

PubMed

Zagaja, Mirosław; Andres-Mach, Marta; Patrzylas, Paweł; Pyrka, Daniel; Szpringer, Monika; Florek-Łuszczki, Magdalena; Żółkowska, Dorota; Skalicka-Woźniak, Krystyna; Łuszczki, Jarogniew J

2016-12-01

The aim of this study was to determine the effects of xanthotoxin (8-methoxypsoralen) on the protective action of 5 various second- and third-generation antiepileptic drugs (i.e., lacosamide, lamotrigine, oxcarbazepine, pregabalin and topiramate) in the mouse maximal electroshock-induced seizure model. Seizure activity was evoked in adult male albino Swiss mice by a current (25mA, 500V, 0.2s stimulus duration) delivered via auricular electrodes. Drug-related adverse effects were determined in the chimney, grip-strength and passive avoidance tests. Total brain antiepileptic drug concentrations were measured to confirm pharmacodynamic nature of observed interactions with xanthotoxin. Results indicate that xanthotoxin (100mg/kg, i.p.) significantly enhanced the anticonvulsant action of lacosamide (P<0.01), oxcarbazepine (P<0.05), pregabalin (P<0.01), and topiramate (P<0.001), but not that of lamotrigine in the maximal electroshock-induced seizure test. Moreover, xanthotoxin (50mg/kg) still significantly potentiated the anticonvulsant action of lacosamide (P<0.05), pregabalin (P<0.05), and topiramate (P<0.001) in this seizure test. Xanthotoxin had no significant impact on total brain concentrations of the studied antiepileptic drugs in mice. Furthermore, combinations of xanthotoxin with oxcarbazepine or topiramate produced no adverse effects. However, xanthotoxin in combination with lacosamide, lamotrigine or pregabalin significantly reduced muscular strength in mice in the grip-strength test. In the chimney test, only the combinations of xanthotoxin with pregabalin significantly impaired motor coordination in mice. In conclusion, the combinations of xanthotoxin with oxcarbazepine and topiramate produce beneficial anticonvulsant pharmacodynamic interactions in the maximal electroshock-induced seizure test. A special caution is advised when combining xanthotoxin with pregabalin due to appearance of acute adverse effects. Copyright © 2016 Elsevier B.V. All rights

Thermoelectric Transport Signatures of Dirac Composite Fermions in the Half-Filled Landau Level

NASA Astrophysics Data System (ADS)

Potter, Andrew C.; Serbyn, Maksym; Vishwanath, Ashvin

2016-07-01

The half-filled Landau level is expected to be approximately particle-hole symmetric, which requires an extension of the Halperin-Lee-Read (HLR) theory of the compressible state observed at this filling. Recent work indicates that, when particle-hole symmetry is preserved, the composite fermions experience a quantized π -Berry phase upon winding around the composite Fermi surface, analogous to Dirac fermions at the surface of a 3D topological insulator. In contrast, the effective low-energy theory of the composite fermion liquid originally proposed by HLR lacks particle-hole symmetry and has vanishing Berry phase. In this paper, we explain how thermoelectric transport measurements can be used to test the Dirac nature of the composite fermions by quantitatively extracting this Berry phase. First, we point out that longitudinal thermopower (Seebeck effect) is nonvanishing because of the unusual nature of particle-hole symmetry in this context and is not sensitive to the Berry phase. In contrast, we find that off-diagonal thermopower (Nernst effect) is directly related to the topological structure of the composite Fermi surface, vanishing for zero Berry phase and taking its maximal value for π Berry phase. In contrast, in purely electrical transport signatures, the Berry phase contributions appear as small corrections to a large background signal, making the Nernst effect a promising diagnostic of the Dirac nature of composite fermions.

Hour Glass Half-Full or Half-Empty? Future Time Perspective and Preoccupation with Negative Events Across the Life Span

PubMed Central

Strough, JoNell; de Bruin, Wändi Bruine; Parker, Andrew M.; Lemaster, Philip; Pichayayothin, Nipat; Delaney, Rebecca

2016-01-01

According to socioemotional selectivity theory, older adults' emotional well-being stems from having limited future time perspective that motivates them to maximize well-being in the “here and now.” Presumably, then, older adults' time horizons are associated with emotional competencies that boost positive affect and dampen negative affect, but little research has addressed this. Using a US national adult life-span sample (N= 3,933, 18-93 yrs), we found that a two-factor model of future time perspective (focus on future opportunities; focus on limited time) fit the data better than a one-factor model. Through middle age, people perceived the life-span hourglass as half full—they focused more on future opportunities than limited time. Around age 60, the balance changed to increasingly perceiving the life-span hourglass as half empty—they focused less on future opportunities and more on limited time. This pattern held even after accounting for perceived health, self-reported decision-making ability, and retirement status. At all ages, women's time horizons focused more on future opportunities compared to men's, and men's focused more on limited time. Focusing on future opportunities was associated with reporting less preoccupation with negative events, whereas focusing on limited time was associated with reporting more preoccupation. Older adults reported less preoccupation with negative events and this association was stronger after controlling for their perceptions of limited time and fewer future opportunities, suggesting that other pathways may explain older adults' reports of their ability to disengage from negative events. Insights gained and questions raised by measuring future time perspective as two dimensions are discussed. PMID:27267222

Hour glass half full or half empty? Future time perspective and preoccupation with negative events across the life span.

PubMed

Strough, JoNell; Bruine de Bruin, Wändi; Parker, Andrew M; Lemaster, Philip; Pichayayothin, Nipat; Delaney, Rebecca

2016-09-01

According to socioemotional selectivity theory, older adults' emotional well-being stems from having a limited future time perspective that motivates them to maximize well-being in the "here and now." Presumably, then, older adults' time horizons are associated with emotional competencies that boost positive affect and dampen negative affect, but little research has addressed this. Using a U.S. adult life-span sample (N = 3,933; 18-93 years), we found that a 2-factor model of future time perspective (future opportunities; limited time) fit the data better than a 1-factor model. Through middle age, people perceived the life-span hourglass as half full-they focused more on future opportunities than limited time. Around Age 60, the balance changed to increasingly perceiving the life-span hourglass as half empty-they focused less on future opportunities and more on limited time, even after accounting for perceived health, self-reported decision-making ability, and retirement status. At all ages, women's time horizons focused more on future opportunities compared with men's, and men's focused more on limited time. Focusing on future opportunities was associated with reporting less preoccupation with negative events, whereas focusing on limited time was associated with reporting more preoccupation. Older adults reported less preoccupation with negative events, and this association was stronger after controlling for their perceptions of limited time and fewer future opportunities, suggesting that other pathways may explain older adults' reports of their ability to disengage from negative events. Insights gained and questions raised by measuring future time perspective as 2 dimensions are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Teacher Praise: Maximizing the Motivational Impact. Teaching Strategies.

ERIC Educational Resources Information Center

McVey, Mary D.

2001-01-01

Recognizes the influence of praise on human behavior, and provides specific suggestions on how to maximize the positive effects of praise when intended as positive reinforcement. Examines contingency, specificity, and selectivity aspects of praise. Cautions teachers to avoid the controlling effects of praise and the possibility that praise may…

Nonimaging optics maximizing exergy for hybrid solar system

NASA Astrophysics Data System (ADS)

Winston, Roland; Jiang, Lun; Abdelhamid, Mahmoud; Widyolar, Bennett K.; Ferry, Jonathan; Cygan, David; Abbasi, Hamid; Kozlov, Alexandr; Kirk, Alexander; Elarde, Victor; Osowski, Mark

2016-09-01

The project team of University of California at Merced (UC-Merced), Gas Technology Institute (GTI) and MicroLink Devices Inc. (MicroLink) are developing a hybrid solar system using a nonimaging compound parabolic concentrator (CPC) that maximizes the exergy by delivering direct electricity and on-demand heat. The hybrid solar system technology uses secondary optics in a solar receiver to achieve high efficiency at high temperature, collects heat in particles and uses reflective liftoff cooled double junction (2J) InGaP/GaAs solar cells with backside infrared (IR) reflectors on the secondary optical element to raise exergy efficiency. The nonimaging optics provides additional concentration towards the high temperature thermal stream and enables it to operate efficiently at 650 °C while the solar cell is maintained at 40 °C to operate as efficiently as possible.

Short-term effects of fertilization on photosynthesis and leaf morphology of field-grown loblolly pine following long-term exposure to elevated CO2 concentration

Treesearch

Chris A. Maier; Sari Palmroth; Eric Ward

2008-01-01

We examined effects of a first nitrogen (N) fertilizer application on upper-canopy needle morphology and gas exchange in ~20-m-tall loblolly pine (Pinus taeda L.) exposed to elevated carbon dioxide concentration ([CO2]) for 9 years. Duke Forest free-air CO2 enrichment (FACE) plots were split and half of...

Chromenylchalcones with inhibitory effects on monoamine oxidase B.

PubMed

Jo, Geunhyeong; Ahn, Seunghyun; Kim, Bong-Gyu; Park, Hye Ri; Kim, Young Hwa; Choo, Hyun Ah; Koh, Dongsoo; Chong, Youhoon; Ahn, Joong-Hoon; Lim, Yoongho

2013-12-15

Structure-activity relationship (SAR) calculations were used to find monoamine oxidase-B (MAO-B) inhibitors by identifying pharmacophores exhibiting high inhibitory activities. Several such chromenylchalcones were designed and synthesized accordingly. Their inhibitory effects on MAO-B were determined using an HPLC-based method and an MAO-B enzyme assay kit. (E)-3-(6-Methoxy-2H-chromen-3-yl)-1-(2-methoxyphenyl)prop-2-en-1-one exhibited a half-maximal inhibitory concentration of 320 nM. Its molecular-level binding mode with the three-dimensional structure of MAO-B was elucidated using an in silico docking study. The chromenylchalcone scaffold, which is derived from natural products including isoflavonoids and chalcones, had not been previously reported as an MAO-B inhibitor. Copyright © 2013 Elsevier Ltd. All rights reserved.

Half radiofrequency pulse excitation with a dedicated prescan to correct eddy current effect and gradient delay.

PubMed

Abe, Takayuki

2013-03-01

To improve the slice profile of the half radiofrequency (RF) pulse excitation and image quality of ultrashort echo time (UTE) imaging by compensating for an eddy current effect. The dedicated prescan has been developed to measure the phase accumulation due to eddy currents induced by the slice-selective gradient. The prescan measures two one-dimensional excitation k-space profiles, which can be acquired with a readout gradient in the slice-selection direction by changing the polarity of the slice-selective gradient. The time shifts due to the phase accumulation in the excitation k-space were calculated. The time shift compensated for the start time of the slice-selective gradient. The total prescan time was 6-15 s. The slice profile and the UTE image with the half RF pulse excitation were acquired to evaluate the slice selectivity and the image quality. Improved slice selectivity was obtained. The simple method proposed in this paper can eliminate eddy current effect. Good UTE images were obtained. The slice profile of the half RF pulse excitation and the image quality of UTE images have been improved by using a dedicated prescan. This method has a possibility that can improve the image quality of a clinical UTE imaging.

Improving Large Cetacean Implantable Satellite Tag Designs to Maximize Tag Robustness and Minimize Health Effects to Individual Animals

DTIC Science & Technology

2013-09-30

Designs to Maximize Tag Robustness and Minimize Health Effects to Individual Animals Alexandre N. Zerbini Cascadia Research Collective 218 ½ 4th...the blubber-muscle interface and minimize physical and physiological effects of body penetrating tags to individual animals . OBJECTIVES (1...integrity of designs created in Objective (1) during laboratory experiments and in cetacean carcasses ; (3) Examine structural tissue damage in the

Using Bar Velocity to Predict the Maximum Dynamic Strength in the Half-Squat Exercise.

PubMed

Loturco, Irineu; Pereira, Lucas A; Cal Abad, Cesar C; Gil, Saulo; Kitamura, Katia; Kobal, Ronaldo; Nakamura, Fábio Y

2016-07-01

To determine whether athletes from different sport disciplines present similar mean propulsive velocity (MPV) in the half-squat (HS) during submaximal and maximal tests, enabling prediction of 1-repetition maximum (1-RM) from MPV at any given submaximal load. Sixty-four male athletes, comprising American football, rugby, and soccer players; sprinters and jumpers; and combat-sport strikers attended 2 testing sessions separated by 2-4 wk. On the first visit, a standardized 1-RM test was performed. On the second, athletes performed HSs on Smith-machine equipment, using relative percentages of 1-RM to determine the respective MPV of submaximal and maximal loads. Linear regression established the relationship between MPV and percentage of 1-RM. A very strong linear relationship (R2 ≈ .96) was observed between the MPV and the percentages of HS 1-RM, resulting in the following equation: %HS 1-RM = -105.05 × MPV + 131.75. The MPV at HS 1-RM was ~0.3 m/s. This equation can be used to predict HS 1-RM on a Smith machine with a high degree of accuracy.

Clinical pharmacology of methadone in dogs.

PubMed

Ingvast-Larsson, Carina; Holgersson, Anja; Bondesson, Ulf; Lagerstedt, Anne-Sofie; Olsson, Kerstin

2010-01-01

To investigate the pharmacokinetics and effects of methadone on behaviour and plasma concentrations of cortisol and vasopressin in healthy dogs. Randomized, cross-over, experimental trial. Nine adult dogs (beagle and beagle cross breeds), four males and five females. Methadone hydrochloride, 0.4 mg kg(-1), was administered intravenously (IV) and subcutaneously (SC) with a crossover design. Drug and hormone analyses in plasma were performed using Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry and radioimmunoassay respectively. Behavioural data were collected using a standardized protocol. After IV administration, the plasma concentration of methadone at 10 minutes was 82.1 +/- 9.2 ng mL(-1) (mean +/- SD), the terminal half-life was 3.9 +/- 1.0 hours, the volume of distribution 9.2 +/- 3.3 L kg(-1) and plasma clearance 27.9 +/- 7.6 mL minute(-1) kg(-1). After SC administration, time to maximal plasma concentration was 1.26 +/- 1.04 hours and maximal plasma concentration of methadone was 23.9 +/- 14.4 ng mL(-1), the terminal half-life was 10.7 +/- 4.3 hours and bioavailability was 79 +/- 22%. Concentrations of both cortisol and vasopressin were increased for an hour following IV methadone. The observed behavioural effects of methadone were decreased licking and swallowing and an increase in whining after SC administration. The latter finding is notable as it can be misinterpreted as pain when methadone is used as an analgesic. When methadone was administered by the SC route, the half-life was longer, but the individual variation in plasma concentrations was greater compared with IV administration. Increased frequency of whining occurred after administration of methadone and may be a drug effect and not a sign of pain. Cortisol and vasopressin concentrations in plasma may not be suitable for evaluating analgesia after methadone treatment.

Eryptosis and hemorheological responses to maximal exercise in athletes: Comparison between running and cycling.

PubMed

Nader, E; Guillot, N; Lavorel, L; Hancco, I; Fort, R; Stauffer, E; Renoux, C; Joly, P; Germain, M; Connes, P

2018-05-01

We compared the effects of cycling and running exercise on hemorheological and hematological properties, as well as eryptosis markers. Seven endurance-trained subjects randomly performed a progressive and maximal exercise test on a cycle ergometer and a treadmill. Blood was sampled at rest and at the end of the exercise to analyze hematological and blood rheological parameters including hematocrit (Hct), red blood cell (RBC) deformability, aggregation, and blood viscosity. Hemoglobin saturation (SpO2), blood lactate, and glucose levels were also monitored. Red blood cell oxidative stress, calcium content, and phosphatidylserine exposure were determined by flow cytometry to assess eryptosis level. Cycling exercise increased blood viscosity and RBC aggregation whereas it had no significant effect on RBC deformability. In contrast, blood viscosity remained unchanged and RBC deformability increased with running. The increase in Hct, lactate, and glucose concentrations and the loss of weight at the end of exercise were not different between running and cycling. Eryptosis markers were not affected by exercise. A significant drop in SpO2 was noted during running but not during cycling. Our study showed that a progressive and maximal exercise test conducted on a cycle ergometer increased blood viscosity while the same test conducted on a treadmill did not change this parameter because of different RBC rheological behavior between the 2 tests. We also demonstrated that a short maximal exercise does not alter RBC physiology in trained athletes. We suspect that exercise-induced hypoxemia occurring during running could be at the origin of the RBC rheological behavior differences with cycling. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of load on ground reaction force and lower limb kinematics during concentric squats.

PubMed

Kellis, Eleftherios; Arambatzi, Fotini; Papadopoulos, Christos

2005-10-01

The purpose of this study was to examine the effects of external load on vertical ground reaction force, and linear and angular kinematics, during squats. Eight males aged 22.1 +/- 0.8 years performed maximal concentric squats using loads ranging from 7 to 70% of one-repetition maximum on a force plate while linear barbell velocity and the angular kinematics of the hip, knee and ankle were recorded. Maximum, average and angle-specific values were recorded. The ground reaction force ranged from 1.67 +/- 0.20 to 3.21 +/- 0.29 times body weight and increased significantly as external load increased (P < 0.05). Bar linear velocity ranged from 0.54 +/- 0.11 to 2.50 +/- 0.50 m x s(-1) and decreased significantly with increasing external load (P < 0.05). Hip, knee and ankle angles at maximum ground reaction force were affected by external load (P < 0.05). The force-barbell velocity curves were fitted using linear models with coefficients (r2) ranging from 0.59 to 0.96. The results suggest that maximal force exertion during squat exercises is not achieved at the same position of the lower body as external load is increased. In contrast, joint velocity coordination does not change as load is increased. The force-velocity relationship was linear and independent from the set of data used for its determination.

Effects of Maximal Sodium and Potassium Conductance on the Stability of Hodgkin-Huxley Model

PubMed Central

Wang, Kuanquan; Yuan, Yongfeng; Zhang, Henggui

2014-01-01

Hodgkin-Huxley (HH) equation is the first cell computing model in the world and pioneered the use of model to study electrophysiological problems. The model consists of four differential equations which are based on the experimental data of ion channels. Maximal conductance is an important characteristic of different channels. In this study, mathematical method is used to investigate the importance of maximal sodium conductance g-Na and maximal potassium conductance g-K. Applying stability theory, and taking g-Na and g-K as variables, we analyze the stability and bifurcations of the model. Bifurcations are found when the variables change, and bifurcation points and boundary are also calculated. There is only one bifurcation point when g-Na is the variable, while there are two points when g-K is variable. The (g-Na,  g-K) plane is partitioned into two regions and the upper bifurcation boundary is similar to a line when both g-Na and g-K are variables. Numerical simulations illustrate the validity of the analysis. The results obtained could be helpful in studying relevant diseases caused by maximal conductance anomaly. PMID:25104970

Numerical method of carbon-based material ablation effects on aero-heating for half-sphere

NASA Astrophysics Data System (ADS)

Wang, Jiang-Feng; Li, Jia-Wei; Zhao, Fa-Ming; Fan, Xiao-Feng

2018-05-01

A numerical method of aerodynamic heating with material thermal ablation effects for hypersonic half-sphere is presented. A surface material ablation model is provided to analyze the ablation effects on aero-thermal properties and structural heat conduction for thermal protection system (TPS) of hypersonic vehicles. To demonstrate its capability, applications for thermal analysis of hypersonic vehicles using carbonaceous ceramic ablators are performed and discussed. The numerical results show the high efficiency and validation of the method developed in thermal characteristics analysis of hypersonic aerodynamic heating.

Allocating dissipation across a molecular machine cycle to maximize flux

PubMed Central

Brown, Aidan I.; Sivak, David A.

2017-01-01

Biomolecular machines consume free energy to break symmetry and make directed progress. Nonequilibrium ATP concentrations are the typical free energy source, with one cycle of a molecular machine consuming a certain number of ATP, providing a fixed free energy budget. Since evolution is expected to favor rapid-turnover machines that operate efficiently, we investigate how this free energy budget can be allocated to maximize flux. Unconstrained optimization eliminates intermediate metastable states, indicating that flux is enhanced in molecular machines with fewer states. When maintaining a set number of states, we show that—in contrast to previous findings—the flux-maximizing allocation of dissipation is not even. This result is consistent with the coexistence of both “irreversible” and reversible transitions in molecular machine models that successfully describe experimental data, which suggests that, in evolved machines, different transitions differ significantly in their dissipation. PMID:29073016

Effects of exercise at individual anaerobic threshold and maximal fat oxidation intensities on plasma levels of nesfatin-1 and metabolic health biomarkers.

PubMed

Mohebbi, Hamid; Nourshahi, Maryam; Ghasemikaram, Mansour; Safarimosavi, Saleh

2015-03-01

Exercise is recognized as an effective method of weight management and short-term appetite regulation tool. The effect of different exercise intensities on appetite regulation hormones in healthy overweight participants has not been intensively studied. The aim of this study was to examine the influence of exercise at individual anaerobic threshold (IAT) and maximal fat oxidation (Fatmax) intensities on the nesfatin-1 response and metabolic health biomarkers in overweight men. Nine healthy overweight males (age, 23.1 ± 1.1 years) volunteered in this study in a counterbalanced order. Blood samples were obtained before, immediately after, and following the first 45 min of recovery for measuring plasma variables. There was significant decrease in plasma levels of nesfatin-1 and leptin after exercise at the IAT intensity which remained lower than baseline following 45 min of recovery. However, nesfatin-1 and leptin levels did not change significantly in any time courses of Fatmax intensity (P > 0.09). Plasma interleukin-6 (IL-6) concentration increased during exercise in both intensities (P < 0.05), whereas changes in free fatty acids (FFAs) and epinephrine concentrations were significant only at the IAT. In addition, a significant correlation was found among nesfatin-1 levels with insulin (r = 0.39, P < 0.05) and glucose (r = 0.41, P < 0.05) at basal and in response to exercise. These results indicate that IAT has a greater exercise-induced appetite regulation effect compared with Fat(max). Based on these data, the intensity of exercise may have an important role in changes of nesfatin-1, leptin, FFA, and epinephrine concentrations even though this was not the case for IL-6 and insulin resistance.

Relevance of liver failure for anti-infective agents: from pharmacokinetic alterations to dosage adjustments

PubMed Central

Büdingen, Fiona V.; Gonzalez, Daniel; Tucker, Amelia N.

2014-01-01

The liver is a complex organ with great ability to influence drug pharmacokinetics (PK). Due to its wide array of function, its impairment has the potential to affect bioavailability, enterohepatic circulation, drug distribution, metabolism, clearance, and biliary elimination. These alterations differ widely depending on the cause of the liver failure, if it is acute or chronic in nature, the extent of impairment, and comorbid conditions. In addition, the effects on liver functions do not occur in a proportional or predictable manner for escalating degrees of liver impairment. The ability of hepatic alterations to influence PK is also dependent on drug characteristics, such as administration route, chemical properties, protein binding, and extraction ratio, among others. This complexity makes it difficult to predict what effects these changes will have on a particular drug. Unlike certain classes of agents, efficacy of anti-infectives is most often dependent on fulfilling PK/pharmacodynamic targets, such as maximum concentration/minimum inhibitory concentration (Cmax/MIC), area under the curve/minimum inhibitory concentration (AUC/MIC), time above MIC (T>MIC), half-maximal inhibitory concentration (IC50) or half-maximal effective concentration (EC50), or the time above the concentration which inhibits viral replication by 95% (T>EC95). Loss of efficacy and/or an increased risk of toxicity may occur in certain circumstances of liver injury. Although it is important to consider these potential alterations and their effects on specific anti-infectives, many lack data to constitute specific dosing adjustments, making it important to monitor patients for effectiveness and toxicities of therapy. PMID:24949199

Effect of 1,25-dihydroxyvitamin D3 on plasma concentrations of calcium-binding protein in normal and rachitic (vitamin D-dependent rickets type I) pigs.

PubMed

Maunder, E M; Pillay, A V; Care, A D

1987-10-01

An i.v. injection of calcitriol (1,25-(OH)2D3) had no effect within 2.5 h on plasma concentrations of calbindin-D9K (vitamin D-induced calcium-binding protein; CaBP) in hypocalcaemic pigs with inherited vitamin D-dependent rickets type I or in their normocalcaemic siblings or half-siblings. Three days later the plasma concentration of CaBP had doubled in the hypocalcaemic pigs, but was unaltered in the normocalcaemic siblings and half-siblings. Following daily i.v. injections of 1,25-(OH)2D3 for a further 5 days (days 4-8) plasma concentrations of CaBP increased in both the hypocalcaemic (days 4-8) and normocalcaemic (day 8) pigs, the effect being more rapid and greater in the hypocalcaemic 1,25-(OH)2D3-deficient animals. An i.v. injection of 1,25-(OH)2D3 to pure Yucatan pigs also had no effect on plasma concentrations of CaBP within 1.5 h, but in the following 1 h there was some indication of an increase in plasma CaBP levels. In contrast to the normal pigs, insulin-induced hypoglycaemia did not lead to a peak in plasma CaBP concentrations in the hypocalcaemic pigs. There was also no change in the plasma concentrations of 1,25-(OH)2D3 associated with the peak in plasma CaBP following insulin-induced hypoglycaemia in normocalcaemic pigs. These results suggest that changes in plasma concentrations of 1,25-(OH)2D3 are not directly involved in mediating the increase in plasma CaBP which follows hypoglycaemia induced by insulin in normal pigs, although 1,25-(OH)2D3 probably plays a permissive role.

Changes in power and force generation during coupled eccentric-concentric versus concentric muscle contraction with training and aging.

PubMed

Caserotti, Paolo; Aagaard, Per; Puggaard, Lis

2008-05-01

Age-related decline in maximal concentric muscle power is associated with frailty and functional impairments in the elderly. Compared to concentric contraction, mechanical muscle output is generally enhanced when muscles are rapidly pre-stretched (eccentric contraction), albeit less pronounced with increasing age. Exercise has been recommended to prevent loss of muscle power and function and recent guidelines indicate training program for increasing muscle power highly relevant for elderly subjects. This study examined the differences in muscle power, force and movement pattern during concentric-alone and coupled eccentric-concentric contraction and selected functional motor performances before and after 36-week multicomponent training including aerobic, strength, balance, flexibility and coordination components in elderly males. Vertical force, excursion, velocity, power and acceleration of the body center of mass were measured in two standardised vertical jumps (squatting jump, SQJ; countermovement jump, CMJ). Pre-stretch enhancement during CMJ did not improve performance [i.e., no enhanced maximal muscle power (Ppeak) and jump height (JH)] compared to concentric-alone muscle contraction (SQJ). Nevertheless, pre-stretch enhancement occurred as for similar SQJ and CMJ maximal performance, elderly people employed lower mechanical work, higher mean muscle power (Pmean), shorter concentric phase duration and shorter body center of mass displacement during CMJ. Post training, CMJ Ppeak, Pmean and JH increased in training group (P<0.05) while Ppeak and JH decreased in control group during the CMJ and SQJ (P<0.05). In conclusion, long-term training counteracted the age-related decline in muscle power and functional performance observed in the control subjects, while substantial gains in muscular performance were observed in the trained elderly.

Abscission: The Phytogerontological Effects of Ethylene

PubMed Central

Abeles, F. B.; Craker, L. E.; Leather, G. R.

1971-01-01

The role of ethylene in the aging of bean (Phaseolus vulgaris L. cv. Red Kidney) petiole abscission zone explants was examined. The data indicate that ethylene does accelerate aging in addition to inducing changes in break strength. Application of ethylene during the aging stage (stage 1) promoted abscission when followed by a second ethylene treatment during the cell separating stage (stage 2). The half-maximal effective concentration of ethylene to induce aging was around 0.3 microliter per liter; 10 microliters per liter was a saturating dose. CO2 reversal of ethylene action during stage 1 was incomplete and gave ambiguous results. CO2 (10%) reversed the effect of 10 microliters per liter ethylene but not 1 microliter per liter ethylene. The possibility that ethylene not only accelerated aging but was also a requirement for it was tested, and experimental evidence in favor of this idea was obtained. It was concluded that ethylene plays a dual role in the abscission of bean petiole explants: a phytogerontological effect and a cellulase-inducing effect. PMID:16657581

Developing a conservation strategy to maximize persistence of an endangered freshwater mussel species while considering management effectiveness and cost

USGS Publications Warehouse

Smith, David R.; McRae, Sarah E.; Augspurger, Tom; Ratcliffe, Judith A.; Nichols, Robert B.; Eads, Chris B.; Savidge, Tim; Bogan, Arthur E.

2015-01-01

We used a structured decision-making process to develop conservation strategies to increase persistence of Dwarf Wedgemussel (Alasmidonta heterodon) in North Carolina, USA, while accounting for uncertainty in management effectiveness and considering costs. Alternative conservation strategies were portfolios of management actions that differed by location of management actions on the landscape. Objectives of the conservation strategy were to maximize species persistence, maintain genetic diversity, maximize public support, and minimize management costs. We compared 4 conservation strategies: 1) the ‘status quo’ strategy represented current management, 2) the ‘protect the best’ strategy focused on protecting the best populations in the Tar River basin, 3) the ‘expand the distribution’ strategy focused on management of extant populations and establishment of new populations in the Neuse River basin, and 4) the ‘hybrid’ strategy combined elements of each strategy to balance conservation in the Tar and Neuse River basins. A population model informed requirements for population management, and experts projected performance of alternative strategies over a 20-y period. The optimal strategy depended on the relative value placed on competing objectives, which can vary among stakeholders. The protect the best and hybrid strategies were optimal across a wide range of relative values with 2 exceptions: 1) if minimizing management cost was of overriding concern, then status quo was optimal, or 2) if maximizing population persistence in the Neuse River basin was emphasized, then expand the distribution strategy was optimal. The optimal strategy was robust to uncertainty in management effectiveness. Overall, the structured decision process can help identify the most promising strategies for endangered species conservation that maximize conservation benefit given the constraint of limited funding.

Photovoltaic performance of the dome-shaped Fresnel-Köhler concentrator

NASA Astrophysics Data System (ADS)

Zamora, Pablo; Benítez, Pablo; Yang, Li; Miñano, Juan Carlos; Mendes-Lopes, Joao; Araki, Kenji

2012-10-01

In order to have a cost-effective CPV system, two key issues must be ensured: high concentration factor and high tolerance. The novel concentrator we are presenting, the dome-shaped Fresnel-Köhler, can widely fulfill these two and other essential issues in a CPV module. This concentrator is based on two previous successful CPV designs: the FK concentrator with a flat Fresnel lens and the dome-shaped Fresnel lens system developed by Daido Steel, resulting on a superior concentrator. The concentrator has shown outstanding simulation results, achieving an effective concentration-acceptance product (CAP) value of 0.72, and an optical efficiency of 85% on-axis (no anti-reflective coating has been used). Moreover, Köhler integration provides good irradiance uniformity on the cell surface and low spectral aberration of this irradiance. This ensures an optimal performance of the solar cell, maximizing its efficiency. Besides, the domeshaped FK shows optimal results for very compact designs, especially in the f/0.7-1.0 range. The dome-shaped Fresnel- Köhler concentrator, natural and enhanced evolution of the flat FK concentrator, is a cost-effective CPV optical design, mainly due to its high tolerances. Daido Steel advanced technique for demolding injected plastic pieces will allow for easy manufacture of the dome-shaped POE of DFK concentrator.

Synergistic Interaction of Retigabine with Levetiracetam in the Mouse Maximal Electroshock-Induced Seizure Model: A Type II Isobolographic Analysis.

PubMed

Luszczki, Jarogniew J; Zagaja, Mirosław; Miziak, Barbara; Florek-Luszczki, Magdalena; Czuczwar, Stanislaw J

2015-01-01

To assess interactions between retigabine and levetiracetam in suppressing maximal electroshock-induced tonic seizures in Albino Swiss mice, type II isobolographic analysis was used. Total brain antiepileptic drug concentrations were measured with high pressure liquid chromatography. The combinations of retigabine with levetiracetam at the fixed-ratios of 1:5 and 1:10 were supra-additive (synergistic; p < 0.05) in terms of seizure suppression, while the combinations at the fixed-ratios of 1:1 and 1:2 were additive. No pharmacokinetic changes in total brain concentrations of levetiracetam and retigabine were documented, indicating the pharmacodynamic nature of interaction between these antiepileptic drugs in the mouse maximal electroshock-induced tonic seizure model. The combination of retigabine with levetiracetam at the fixed-ratios of 1:5 and 1:10 appears to be particularly beneficial combination exerting supra-additive interaction in suppressing maximal electroshock-induced tonic seizures. © 2015 S. Karger AG, Basel.

General form of a cooperative gradual maximal covering location problem

NASA Astrophysics Data System (ADS)

Bagherinejad, Jafar; Bashiri, Mahdi; Nikzad, Hamideh

2018-07-01

Cooperative and gradual covering are two new methods for developing covering location models. In this paper, a cooperative maximal covering location-allocation model is developed (CMCLAP). In addition, both cooperative and gradual covering concepts are applied to the maximal covering location simultaneously (CGMCLP). Then, we develop an integrated form of a cooperative gradual maximal covering location problem, which is called a general CGMCLP. By setting the model parameters, the proposed general model can easily be transformed into other existing models, facilitating general comparisons. The proposed models are developed without allocation for physical signals and with allocation for non-physical signals in discrete location space. Comparison of the previously introduced gradual maximal covering location problem (GMCLP) and cooperative maximal covering location problem (CMCLP) models with our proposed CGMCLP model in similar data sets shows that the proposed model can cover more demands and acts more efficiently. Sensitivity analyses are performed to show the effect of related parameters and the model's validity. Simulated annealing (SA) and a tabu search (TS) are proposed as solution algorithms for the developed models for large-sized instances. The results show that the proposed algorithms are efficient solution approaches, considering solution quality and running time.

Gamma loop contributing to maximal voluntary contractions in man.

PubMed Central

Hagbarth, K E; Kunesch, E J; Nordin, M; Schmidt, R; Wallin, E U

1986-01-01

A local anaesthetic drug was injected around the peroneal nerve in healthy subjects in order to investigate whether the resulting loss in foot dorsiflexion power in part depended on a gamma-fibre block preventing 'internal' activation of spindle end-organs and thereby depriving the alpha-motoneurones of an excitatory spindle inflow during contraction. The motor outcome of maximal dorsiflexion efforts was assessed by measuring firing rates of individual motor units in the anterior tibial (t.a.) muscle, mean voltage e.m.g. from the pretibial muscles, dorsiflexion force and range of voluntary foot dorsiflexion movements. The tests were performed with and without peripheral conditioning stimuli, such as agonist or antagonist muscle vibration or imposed stretch of the contracting muscles. As compared to control values of t.a. motor unit firing rates in maximal isometric voluntary contractions, the firing rates were lower and more irregular during maximal dorsiflexion efforts performed during subtotal peroneal nerve blocks. During the development of paresis a gradual reduction of motor unit firing rates was observed before the units ceased responding to the voluntary commands. This change in motor unit behaviour was accompanied by a reduction of the mean voltage e.m.g. activity in the pretibial muscles. At a given stage of anaesthesia the e.m.g. responses to maximal voluntary efforts were more affected than the responses evoked by electric nerve stimuli delivered proximal to the block, indicating that impaired impulse transmission in alpha motor fibres was not the sole cause of the paresis. The inability to generate high and regular motor unit firing rates during peroneal nerve blocks was accentuated by vibration applied over the antagonistic calf muscles. By contrast, in eight out of ten experiments agonist stretch or vibration caused an enhancement of motor unit firing during the maximal force tasks. The reverse effects of agonist and antagonist vibration on the

Maximal oxygen uptake and cardiorespiratory response to maximal 400-m free swimming, running and cycling tests in competitive swimmers.

PubMed

Rodríguez, F A

2000-06-01

This study compared the cardiorespiratory response of trained swimmers to 400-m unimpeded front crawl swimming (SW), treadmill running (TR) and ergometer cycling (EC) maximal exercise tests, and evaluated the validity and specificity of a method to measure maximal aerobic power in swimming. Two series of experiments were conducted. In series A (n=15), comparisons were made between VO2peak and other cardiorespiratory variables in three maximal tests: after 400-m SW, and during incremental TR and EC. In series B, VO2 peak and related variables were measured after SW and during EC (n=33). No significant differences were observed between VO2peak and VE in the three modes of exercise, although SW values tended to be higher. After SW, maximal ventilatory response was characterized by higher tidal volumes (VT) and lower respiratory rates (fR) as compared with TR and EC. The highest heart rate values (fH) were also observed in TR, followed by EC and SW. In series B, no significant differences were observed either in peak VO2 or VE, but fH was also lower in SW. A maximal 400-m unimpeded freestyle SW test yields essentially equal or nonsignificantly higher peak VO2 and VE values than during maximal TR or EC tests in trained swimmers. The specific maximal cardiorespiratory response to the SW test is characterized by higher VT, lower fR, and lower fH. Breath-by-breath measurements during the immediate recovery after a 400-m voluntary maximal swim is proposed as a valid and specific test for directly measuring maximal metabolic parameters and evaluating specific maximal aerobic power in swimming.

Prolonged neurophysiologic effects of levetiracetam after oral administration in humans.

PubMed

Epstein, Charles M; Girard-Siqueira, Lhys; Ehrenberg, Joshua Andrew

2008-07-01

To determine whether neurophysiological effects of levetiracetam (LEV) outlast its serum half-life of approximately 7 h. Demonstration of prolonged effects would help to explain the efficacy of LEV at conventional dosing intervals that are longer than the serum half-life. Following an oral dose of LEV 3 g in 12 normal volunteers, we compared transcranial magnetic stimulation (TMS) measures of motor threshold (MT) and recruitment with LEV serum levels and subjective ratings of toxicity over 48 h. Subjects used a two-dimensional visual-analog scale to estimate the time course of any side effects. LEV serum levels and subjective toxicity both peaked around 1 h after oral administration. MT elevation was delayed in comparison to peak serum levels and subjective toxicity. MT was maximally elevated at 6-9 h, and recruitment maximally reduced at 0.6-9 h. Changes in both measures had recovered by approximately 50% at 24 h. Despite the time difference between toxicity and TMS changes, toxicity estimates correlated with the maximum increase in MT. There is a substantial time lag between LEV serum levels and TMS measures of neuronal effects, and a similar temporal dissociation between subjective toxicity and maximum TMS change. The time course of neurophysiological effects, as measured by TMS, may help to explain the sustained clinical efficacy of LEV despite a short peripheral half-life.

Half-marathoners are younger and slower than marathoners.

PubMed

Knechtle, Beat; Nikolaidis, Pantelis T; Zingg, Matthias A; Rosemann, Thomas; Rüst, Christoph A

2016-01-01

Age and performance trends of elite and recreational marathoners are well investigated, but not for half-marathoners. We analysed age and performance trends in 508,108 age group runners (125,894 female and 328,430 male half-marathoners and 10,205 female and 43,489 male marathoners) competing between 1999 and 2014 in all flat half-marathons and marathons held in Switzerland using single linear regression analyses, mixed-effects regression analyses and analyses of variance. The number of women and men increased across years in both half-marathons and marathons. There were 12.3 times more female half-marathoners than female marathoners and 7.5 times more male half-marathoners than male marathoners. For both half-marathons and marathons, most of the female and male finishers were recorded in age group 40-44 years. In half-marathons, women (10.29 ± 3.03 km/h) were running 0.07 ± 0.06 km/h faster (p < 0.001) than men (10.22 ± 3.06 km/h). Also in marathon, women (14.77 ± 4.13 km/h) were running 0.28 ± 0.16 km/h faster (p < 0.001) than men (14.48 ± 4.07 km/h). In marathon, women (42.18 ± 10.63 years) were at the same age than men (42.06 ± 10.45 years) (p > 0.05). Also in half-marathon, women (41.40 ± 10.63 years) were at the same age than men (41.31 ± 10.30 years) (p > 0.05). However, women and men marathon runners were older than their counterpart half-marathon runners (p < 0.001). In summary, (1) more athletes competed in half-marathons than in marathons, (2) women were running faster than men, (3) half-marathoners were running slower than marathoners, and (4) half-marathoners were younger than marathoners.

Quantum-Inspired Maximizer

NASA Technical Reports Server (NTRS)

Zak, Michail

2008-01-01

A report discusses an algorithm for a new kind of dynamics based on a quantum- classical hybrid-quantum-inspired maximizer. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen 'computational' potential. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables, using classical methods. Such optimal combination of characteristics is a perfect match for quantum-inspired computing. As an application, an algorithm for global maximum of an arbitrary integrable function is proposed. The idea of the proposed algorithm is very simple: based upon the Quantum-inspired Maximizer (QIM), introduce a positive function to be maximized as the probability density to which the solution is attracted. Then the larger value of this function will have the higher probability to appear. Special attention is paid to simulation of integer programming and NP-complete problems. It is demonstrated that the problem of global maximum of an integrable function can be found in polynomial time by using the proposed quantum- classical hybrid. The result is extended to a constrained maximum with applications to integer programming and TSP (Traveling Salesman Problem).

Optimization of applied voltages for on-chip concentration of DNA using nanoslit

NASA Astrophysics Data System (ADS)

Azuma, Naoki; Itoh, Shintaro; Fukuzawa, Kenji; Zhang, Hedong

2017-12-01

On-chip sample concentration is an effective pretreatment to improve the detection sensitivity of lab-on-a-chip devices for biochemical analysis. In a previous study, we successfully achieved DNA sample concentration using a nanoslit fabricated in the microchannel of a device designed for DNA size separation. The nanoslit was a channel with a depth smaller than the diameter of a random coil-shaped DNA molecule. The concentration was achieved using the entropy trap at the boundary between the microchannel and the nanoslit. DNA molecules migrating toward the nanoslit owing to electrophoresis were trapped in front of the nanoslit and the concentration was enhanced over time. In this study, we successfully maximize the molecular concentration by optimizing the applied voltage for electrophoresis and verifying the effect of temperature. In addition, we propose a model formula that predicts the molecular concentration, the validity of which is confirmed through comparison with experimental results.

A new augmentation based algorithm for extracting maximal chordal subgraphs

DOE PAGES

Bhowmick, Sanjukta; Chen, Tzu-Yi; Halappanavar, Mahantesh

2014-10-18

If every cycle of a graph is chordal length greater than three then it contains an edge between non-adjacent vertices. Chordal graphs are of interest both theoretically, since they admit polynomial time solutions to a range of NP-hard graph problems, and practically, since they arise in many applications including sparse linear algebra, computer vision, and computational biology. A maximal chordal subgraph is a chordal subgraph that is not a proper subgraph of any other chordal subgraph. Existing algorithms for computing maximal chordal subgraphs depend on dynamically ordering the vertices, which is an inherently sequential process and therefore limits the algorithms’more » parallelizability. In our paper we explore techniques to develop a scalable parallel algorithm for extracting a maximal chordal subgraph. We demonstrate that an earlier attempt at developing a parallel algorithm may induce a non-optimal vertex ordering and is therefore not guaranteed to terminate with a maximal chordal subgraph. We then give a new algorithm that first computes and then repeatedly augments a spanning chordal subgraph. After proving that the algorithm terminates with a maximal chordal subgraph, we then demonstrate that this algorithm is more amenable to parallelization and that the parallel version also terminates with a maximal chordal subgraph. That said, the complexity of the new algorithm is higher than that of the previous parallel algorithm, although the earlier algorithm computes a chordal subgraph which is not guaranteed to be maximal. Finally, we experimented with our augmentation-based algorithm on both synthetic and real-world graphs. We provide scalability results and also explore the effect of different choices for the initial spanning chordal subgraph on both the running time and on the number of edges in the maximal chordal subgraph.« less

A New Augmentation Based Algorithm for Extracting Maximal Chordal Subgraphs.

PubMed

Bhowmick, Sanjukta; Chen, Tzu-Yi; Halappanavar, Mahantesh

2015-02-01

A graph is chordal if every cycle of length greater than three contains an edge between non-adjacent vertices. Chordal graphs are of interest both theoretically, since they admit polynomial time solutions to a range of NP-hard graph problems, and practically, since they arise in many applications including sparse linear algebra, computer vision, and computational biology. A maximal chordal subgraph is a chordal subgraph that is not a proper subgraph of any other chordal subgraph. Existing algorithms for computing maximal chordal subgraphs depend on dynamically ordering the vertices, which is an inherently sequential process and therefore limits the algorithms' parallelizability. In this paper we explore techniques to develop a scalable parallel algorithm for extracting a maximal chordal subgraph. We demonstrate that an earlier attempt at developing a parallel algorithm may induce a non-optimal vertex ordering and is therefore not guaranteed to terminate with a maximal chordal subgraph. We then give a new algorithm that first computes and then repeatedly augments a spanning chordal subgraph. After proving that the algorithm terminates with a maximal chordal subgraph, we then demonstrate that this algorithm is more amenable to parallelization and that the parallel version also terminates with a maximal chordal subgraph. That said, the complexity of the new algorithm is higher than that of the previous parallel algorithm, although the earlier algorithm computes a chordal subgraph which is not guaranteed to be maximal. We experimented with our augmentation-based algorithm on both synthetic and real-world graphs. We provide scalability results and also explore the effect of different choices for the initial spanning chordal subgraph on both the running time and on the number of edges in the maximal chordal subgraph.

Residual effect of a 7-amino metabolite of clonazepam on GABAA receptor function in the nucleus reticularis thalami of the rat.

PubMed

Munakata, Mitsutoshi; Tsuchiya, Shigeru

2008-10-01

A considerable amount of 7-aminoclonazepam (ACZP), a major metabolite of clonazepam (CZP), is present in the brain during CZP treatment, yet the pharmacological properties of ACZP remain unknown. We investigated the effects of ACZP on the GABA(A) receptor-mediated currents (I(GABA)) in neurons from the nucleus reticularis thalami (NRT) of the rat, using a nystatin-perforated patch technique. Neurons in which CZP (10 nM) exerted prominent augmentation (>100% augmentation) of I(GABA), which comprised 32% of the neurons tested, were included for the analysis of ACZP. In these neurons, ACZP augmented I(GABA), which was blocked by 10 microM flumazenil, a benzodiazepine receptor (BZR) antagonist. The half-maximal effective concentration of ACZP was 124 nM, whereas that of CZP was 1.8 nM. The maximal enhancements induced by ACZP and CZP were 38% and 170%, respectively. In neurons from the ventrobasal complex of the thalamus, the effect of ACZP was negligible. Our results suggest that ACZP was a weak partial BZR agonist and that ACZP may competitively modify the effect of CZP, leading to clinical consequences for patients with high levels of ACZP.

Impacts of Maximizing Tendencies on Experience-Based Decisions.

PubMed

Rim, Hye Bin

2017-06-01

Previous research on risky decisions has suggested that people tend to make different choices depending on whether they acquire the information from personally repeated experiences or from statistical summary descriptions. This phenomenon, called as a description-experience gap, was expected to be moderated by the individual difference in maximizing tendencies, a desire towards maximizing decisional outcome. Specifically, it was hypothesized that maximizers' willingness to engage in extensive information searching would lead maximizers to make experience-based decisions as payoff distributions were given explicitly. A total of 262 participants completed four decision problems. Results showed that maximizers, compared to non-maximizers, drew more samples before making a choice but reported lower confidence levels on both the accuracy of knowledge gained from experiences and the likelihood of satisfactory outcomes. Additionally, maximizers exhibited smaller description-experience gaps than non-maximizers as expected. The implications of the findings and unanswered questions for future research were discussed.

Supersaturation-Limited and Unlimited Phase Spaces Compete to Produce Maximal Amyloid Fibrillation near the Critical Micelle Concentration of Sodium Dodecyl Sulfate.

PubMed

So, Masatomo; Ishii, Akira; Hata, Yasuko; Yagi, Hisashi; Naiki, Hironobu; Goto, Yuji

2015-09-15

Although various natural and synthetic compounds have been shown to accelerate or inhibit the formation of amyloid fibrils, the mechanisms by which they achieve these adverse effects in a concentration-dependent manner currently remain unclear. Sodium dodecyl sulfate (SDS), one of the compounds that has adverse effects on fibrillation, is the most intensively studied. Here we examined the effects of a series of detergents including SDS on the amyloid fibrillation of β2-microglobulin at pH 7.0, a protein responsible for dialysis-related amyloidosis. In all the detergents examined (i.e., SDS, sodium decyl sulfate, sodium octyl sulfate, and sodium deoxycholate), amyloid fibrillation was accelerated and inhibited at concentrations near the critical micelle concentration (CMC) and higher than CMC, respectively. The most stable conformation changed from monomers with a β-structure to amyloid fibrils with a β-structure and then to α-helical complexes with micelles with an increase in detergent concentrations. These results suggest that competition between supersaturation-limited fibrillation and unlimited mixed micelle formation between proteins and micelles underlies the detergent concentration-dependent complexity of amyloid fibrillation.

Effects of Added Resistance Training on Physical Fitness, Body Composition, and Serum Hormone Concentrations During Eight Weeks of Special Military Training Period.

PubMed

Vaara, Jani P; Kokko, Juha; Isoranta, Manne; Kyröläinen, Heikki

2015-11-01

A high volume of military training has been shown to compromise muscle strength development. We examined effects of added low-volume resistance training during special military training (ST) period, which took place after basic training period. Male conscripts (n = 25) were assigned to standardized ST with added resistance training group (TG, n = 13) and group with standardized ST only (control) (CG, n = 12). Standardized ST with added resistance training group performed 2 resistance training sessions per week for 8 weeks: hypertrophic strength (weeks 1-3), maximal strength (weeks 4-6) and power training (weeks 7-8). Maximal strength tests, load carriage performance (3.2 km, 27 kg), and hormone concentrations were measured before and after ST (mean ± SD). Both groups improved similarly in their load carriage performance time (TG: 1,162 ± 116 seconds vs. 1,047 ± 81 seconds; CG: 1,142 ± 95 seconds vs. 1,035 ± 81 seconds) (p < 0.001) but decreased maximal strength of the lower extremities (TG: 5,250 ± 1,110 N vs. 4,290 ± 720 N; CG: 5,170 ± 1,050 N vs. 4,330 ± 1,230 N) and back muscles (TG: 4,290 ± 990 N vs. 3,570 ± 48 N; CG: 3,920 ± 72 N vs. 3,410 ± 53 N) (p ≤ 0.05). Maximal strength of the upper extremities improved in CG (1,040 ± 200 N vs. 1,140 ± 200 N) (p ≤ 0.05) but not in TG. Maximal strength of the abdominal muscles improved in TG (3,260 ± 510 N vs. 3,740 ± 75 N) (p ≤ 0.05) but not in CG. Testosterone concentration increased in CG (15.2 ± 3.6 nmol·L⁻¹ vs. 21.6 ± 5.0 nmol·L⁻¹) (p < 0.01) but not in TG (18.6 ± 4.3 nmol·L⁻¹ vs. 19.5 ± 9.4 nmol·L⁻¹). In conclusion, interference with strength gains might be related to the high volume of aerobic activities and too low volume of resistance training during ST. To develop strength characteristics, careful periodization and individualization should be adopted in ST.

Looking East at BottomHalf of Reactor Number One and TopHalf ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking East at Bottom-Half of Reactor Number One and Top-Half of Reactor Number 2 Including Weigh Hopper on Third Floor of Oxide Building - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO

Effect of training on blood volume and plasma hormone concentrations in the elderly

NASA Technical Reports Server (NTRS)

Carroll, J. F.; Convertino, V. A.; Wood, C. E.; Graves, J. E.; Lowenthal, D. T.; Pollock, M. L.

1995-01-01

The purpose of this investigation was to determine the effects of 6 months of endurance training on resting plasma (PV) and blood volume (BV), and resting hormone and electrolyte concentrations in the elderly. Thirty-eight elderly men and women (ages 60-82 yr) were assigned to endurance exercise training (N = 29) or to control (N = 9) groups. Resting plasma levels of adrenocorticotropic hormone, vasopressin, aldosterone, norepinephrine, epinephrine, sodium, potassium, and protein were measured at the start (T1) and end (T2) of 26 wk of training. PV measurement was performed using the Evan's blue dye technique. Endurance training consisted of uphill treadmill walking or stairclimbing exercise 3 times.wk-1, 30-45 min.d-1, at 75-84% of maximal heart rate reserve. The exercise group increased VO2max by 11.2% (P < or = 0.05) and increased resting PV and BV by 11.2% and 12.7% (P < or = 0.05), respectively. Hormone and electrolyte levels in the exercise group remained unchanged; all variables were unchanged in the control group. These results are similar to findings in younger individuals. Because plasma hormone concentrations were maintained despite a chronically elevated BV, endurance training in healthy, elderly subjects may be associated with a resetting of volume receptors.

Effects of climate and soil properties on U.S. home lawn soil organic carbon concentration and pool.

PubMed

Selhorst, Adam; Lal, Rattan

2012-12-01

Following turfgrass establishment, soils sequester carbon (C) over time. However, the magnitude of this sequestration may be influenced by a range of climatic and soil factors. Analysis of home lawn turfgrass soils throughout the United States indicated that both climatic and soil properties significantly affected the soil organic carbon (SOC) concentration and pool to 15-cm depth. Soil sampling showed that the mean annual temperature (MAT) was negatively correlated with SOC concentration. Additionally, a nonlinear interaction was observed between mean annual precipitation (MAP) and SOC concentration with optimal sequestration occurring in soils receiving 60-70 cm of precipitation per year. Furthermore, soil properties also influenced SOC concentration. Soil nitrogen (N) had a high positive correlation with SOC concentration, as a 0.1 % increase in N concentration led to a 0.99 % increase in SOC concentration. Additionally, soil bulk density (ρ(b)) had a curvilinear interaction with SOC concentration, with an increase in ρ(b) indicating a positive effect on SOC concentration until a ρ(b) of ~1.4-1.5 Mg m(-3) was attained, after which, inhibition of SOC sequestration occurred. Finally, no correlation between SOC concentration or pool was observed with texture. Based upon these results, highest SOC pools within this study are observed in regions of low MAT, moderate MAP (60-70 cm year(-1)), high soil N concentration, and moderate ρ(b) (1.4-1.5 Mg m(-3)). In order to maximize the C storage capacity of home lawns, non C-intensive management practices should be used to maintain soils within these conditions.

Effects of ethnicity on the relationship between vertical jump and maximal power on a cycle ergometer.

PubMed

Rouis, Majdi; Coudrat, Laure; Jaafar, Hamdi; Attiogbé, Elvis; Vandewalle, Henry; Driss, Tarak

2016-06-01

The aim of this study was to verify the impact of ethnicity on the maximal power-vertical jump relationship. Thirty-one healthy males, sixteen Caucasian (age: 26.3 ± 3.5 years; body height: 179.1 ± 5.5 cm; body mass: 78.1 ± 9.8 kg) and fifteen Afro-Caribbean (age: 24.4 ±2.6 years; body height: 178.9 ± 5.5 cm; body mass: 77.1 ± 10.3 kg) completed three sessions during which vertical jump height and maximal power of lower limbs were measured. The results showed that the values of vertical jump height and maximal power were higher for Afro-Caribbean participants (62.92 ± 6.7 cm and 14.70 ± 1.75 W∙kg-1) than for Caucasian ones (52.92 ± 4.4 cm and 12.75 ± 1.36 W∙kg-1). Moreover, very high reliability indices were obtained on vertical jump (e.g. 0.95 < ICC < 0.98) and maximal power performance (e.g. 0.75 < ICC < 0.97). However, multiple linear regression analysis showed that, for a given value of maximal power, the Afro-Caribbean participants jumped 8 cm higher than the Caucasians. Together, these results confirmed that ethnicity impacted the maximal power-vertical jump relationship over three sessions. In the current context of cultural diversity, the use of vertical jump performance as a predictor of muscular power should be considered with caution when dealing with populations of different ethnic origins.

[Evaluation of the 2.5 mg fentanyl patch, applied using the half-side application procedure in patients with cancer pain].

PubMed

Kokubun, Hideya; Matoba, Motohiro; Okazaki, Miyoko; Hoka, Sumio; Yago, Kazuo

2008-03-01

Occasionally, pain control with the fentanyl patch may lead to overdose at an initial dose of 2.5 mg, as well as during dose increase from 2.5 to 5.0 mg. Respiratory depression and other adverse drug reactions associated with fentanyl overdose have been observed in several of our patients. We developed a procedure for applying one-half of the fentanyl patch formulations and evaluated the new mode of application by examining the fentanyl concentration in 32 patients with cancer-related pain who had been using the fentanyl patch for pain control. While some patients were treated with the full-sized 2.5-, 5.0-, or 7.5-mg formulations, others were treated with the half-sized 2.5-mg formulation. The fentanyl patch was equally divided by drawing a line on the side on which the product name and dose were written. Tegaderm was applied to the patient's skin, and after detaching from the protective liner, half of the patch was applied to overlap Tegaderm along the line and the other half applied directly to the skin. Blood samples were collected 48-72 h after patch application. The mean serum concentration of fentanyl given in the half-sized 2.5-mg formulation was 0.286 ng/ml, which was approximately one-half of the concentration of the full-sized 2.5-mg formulation, 0.544 ng/ml. Therefore the 2.5-mg fentanyl patch, applied using the one-half procedure we developed, is clinically useful.

Increased erythropoietin concentration after repeated apneas in humans.

PubMed

de Bruijn, Robert; Richardson, Matt; Schagatay, Erika

2008-03-01

Hypoxia-induced increases in red blood cell production have been found in both altitude-adapted populations and acclimatized lowlanders. This process is mediated by erythropoietin (EPO) released mainly by the hypoxic kidney. We have previously observed high hemoglobin concentrations in elite breath-hold divers and our aim was to investigate whether apnea-induced hypoxia could increase EPO concentration. Ten healthy volunteers performed 15 maximal duration apneas, divided into three series of five apneas, each series separated by 10 min of rest. Apneas within series were separated by 2 min and preceded by 1 min of hyperventilation to increase apnea duration and arterial oxygen desaturation. When EPO concentration after serial apneas was compared to baseline values, an average maximum increase of 24% was found (P < 0.01). No changes in EPO concentration were observed during a control day without apnea, eliminating possible effects of a diurnal rhythm or blood loss. We therefore conclude that serial apneas increase circulating EPO concentration in humans.

Search for effective spin injection heterostructures based on half-metal Heusler alloys/gallium arsenide semiconductors: A theoretical investigation

NASA Astrophysics Data System (ADS)

Sivakumar, Chockalingam

Efficient electrical spin injection from half-metal (HM) electrodes into semiconducting (SC) channel material is a desirable aspect in spintronics, but a challenging one. Half-metals based on the Heusler alloy family are promising candidates as spin sources due to their compatibility with compound SCs, and very high Curie temperatures. Numerous efforts were made in the past two decades to grow atomically abrupt interfaces between HM_Heusler and SC heterostructures. However, diffusion of magnetic impurities into the semiconductor, defects and disorder near the interface, and formation of reacted phases were great challenges. A number of theoretical efforts were undertaken to understand the role of such material defects in destroying the half-metallicity and also to propose promising half-metal/SC heterostructures based on first principles. This dissertation summarizes the investigations undertaken to decode the complexity of, and to understand the various physical properties of, a number of real-world Heusler/SC heterostructure samples, based on the ab initio density functional theory (DFT) approach. In addition, it summarizes various results from the first principles-based search for promising half-metal/SC heterostructures. First, I present results from DFT-based predictive models of actual Co 2MnSi (CMS)/GaAs heterostructures grown in (001) texture. I investigate the physical, chemical, electronic, and magnetic properties to understand the complexity of these structures and to pinpoint the origin of interfacial effects, when present. Based on the investigations of such models, I discuss the utility of those actual samples in spintronic applications. Next, I summarise the results from an ab initio DFT-based survey of 6 half-Heusler half-metal/GaAs heterostructure models in (110) texture, since compound semiconductors such as GaAs have very long spin lifetime in (110) layering. I show 3 half-Heusler alloys (CoVAs, NiMnAs, and RhFeGe), that when interfaced with Ga

Time Series Modeling of Nano-Gold Immunochromatographic Assay via Expectation Maximization Algorithm.

PubMed

Zeng, Nianyin; Wang, Zidong; Li, Yurong; Du, Min; Cao, Jie; Liu, Xiaohui

2013-12-01

In this paper, the expectation maximization (EM) algorithm is applied to the modeling of the nano-gold immunochromatographic assay (nano-GICA) via available time series of the measured signal intensities of the test and control lines. The model for the nano-GICA is developed as the stochastic dynamic model that consists of a first-order autoregressive stochastic dynamic process and a noisy measurement. By using the EM algorithm, the model parameters, the actual signal intensities of the test and control lines, as well as the noise intensity can be identified simultaneously. Three different time series data sets concerning the target concentrations are employed to demonstrate the effectiveness of the introduced algorithm. Several indices are also proposed to evaluate the inferred models. It is shown that the model fits the data very well.

Effect of active warm-up duration on morning short-term maximal performance during Ramadan.

PubMed

Baklouti, Hana; Chtourou, Hamdi; Aloui, Asma; Chaouachi, Anis; Souissi, Nizar

2015-01-01

Purpose To examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the morning. Methods Twelve healthy active men performed four Wingate tests for measurement of peak power and mean power before and during Ramadan at 09:00 a.m. The tests were performed on separate days, after either a 5-min or a 15-min warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. Oral temperature was measured at rest and after warming-up. Furthermore, ratings of perceived exertion were obtained immediately after the Wingate test. Results Oral temperature was higher after the 15-min warm-up than the 5-min warm-up throughout the study. Moreover, peak power and mean power were higher after the 15-min warm-up than the 5-min warm-up before Ramadan. However, during Ramadan, there was no significant difference between the two warm-up durations. In addition, ratings of perceived exertion were higher after the 15-min warm-up than the 5-min warm-up only during Ramadan. Conclusions There is no need to prolong the warm-up period before short-term maximal exercise performed during Ramadan in the morning.

Effect of active warm-up duration on morning short-term maximal performance during Ramadan.

PubMed

Baklouti, Hana; Chtourou, Hamdi; Aloui, Asma; Chaouachi, Anis; Souissi, Nizar

2015-01-01

To examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the morning. Twelve healthy active men performed four Wingate tests for measurement of peak power and mean power before and during Ramadan at 09:00 a.m. The tests were performed on separate days, after either a 5-min or a 15-min warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. Oral temperature was measured at rest and after warming-up. Furthermore, ratings of perceived exertion were obtained immediately after the Wingate test. Oral temperature was higher after the 15-min warm-up than the 5-min warm-up throughout the study. Moreover, peak power and mean power were higher after the 15-min warm-up than the 5-min warm-up before Ramadan. However, during Ramadan, there was no significant difference between the two warm-up durations. In addition, ratings of perceived exertion were higher after the 15-min warm-up than the 5-min warm-up only during Ramadan. There is no need to prolong the warm-up period before short-term maximal exercise performed during Ramadan in the morning.

Effect of active warm-up duration on morning short-term maximal performance during Ramadan

PubMed Central

Baklouti, Hana; Chtourou, Hamdi; Aloui, Asma; Chaouachi, Anis; Souissi, Nizar

2015-01-01

Purpose To examine the effect of active warm-up duration on short-term maximal performance assessed during Ramadan in the morning. Methods Twelve healthy active men performed four Wingate tests for measurement of peak power and mean power before and during Ramadan at 09:00 a.m. The tests were performed on separate days, after either a 5-min or a 15-min warm-up. The warm-up consisted in pedaling at 50% of the power output obtained at the last stage of a submaximal multistage cycling test. Oral temperature was measured at rest and after warming-up. Furthermore, ratings of perceived exertion were obtained immediately after the Wingate test. Results Oral temperature was higher after the 15-min warm-up than the 5-min warm-up throughout the study. Moreover, peak power and mean power were higher after the 15-min warm-up than the 5-min warm-up before Ramadan. However, during Ramadan, there was no significant difference between the two warm-up durations. In addition, ratings of perceived exertion were higher after the 15-min warm-up than the 5-min warm-up only during Ramadan. Conclusions There is no need to prolong the warm-up period before short-term maximal exercise performed during Ramadan in the morning. PMID:25676856

Measurement of the 20F half-life

NASA Astrophysics Data System (ADS)

Hughes, M.; George, E. A.; Naviliat-Cuncic, O.; Voytas, P. A.; Chandavar, S.; Gade, A.; Huyan, X.; Liddick, S. N.; Minamisono, K.; Paulauskas, S. V.; Weisshaar, D.

2018-05-01

The half-life of the 20F ground state was measured using a radioactive beam implanted in a plastic scintillator and recording β γ coincidences together with four CsI(Na) detectors. The result, T1 /2=11.0011 (69) stat(30) sys s, is at variance by 17 combined standard deviations with the two most precise results. The present value revives the poor consistency of results for this half-life and calls for a new measurement, with a technique having different sources of systematic effects, to clarify the discrepancy.

Effects of plyometric training on maximal-intensity exercise and endurance in male and female soccer players.

PubMed

Ramírez-Campillo, Rodrigo; Vergara-Pedreros, Marcelo; Henríquez-Olguín, Carlos; Martínez-Salazar, Cristian; Alvarez, Cristian; Nakamura, Fábio Yuzo; De La Fuente, Carlos I; Caniuqueo, Alexis; Alonso-Martinez, Alicia M; Izquierdo, Mikel

2016-01-01

In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35-1.76), throwing (ES = 0.62-0.78), sprint (ES = 0.86-1.44), change of direction speed (ES = 0.46-0.85) and endurance performance (ES = 0.42-0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.

Effect of sex on wasted left ventricular effort following maximal exercise.

PubMed

Lane, A D; Ranadive, S M; Yan, H; Kappus, R M; Cook, M D; Sun, P; Woods, J A; Wilund, K; Fernhall, B

2013-09-01

Wasted left ventricular effort (∆Ew) refers to work required of the left ventricle to eject blood that does not result in increased stroke volume and is related to left ventricular hypertrophy. Literature shows that men and women have differing ventricular and vascular responses to and following exercise. Our purpose was to determine how ∆Ew changes post-exercise in men and women and examine potential mechanisms. We hypothesized a reduction in ∆Ew that would be greater in men and that central pulse wave velocity and wave intensity (WIA) would be related to ∆Ew. Blood pressures, central pulse wave velocity (cPWV), and WIA were obtained at rest, 15 and 30 min after maximal exercise. Both sexes reduced ∆Ew post-maximal exercise (p>0.05 for interaction), but women had higher ∆Ew at each time point (p<0.05). The first peak of WIA increased 15 min post-exercise only in women (p<0.05). cPWV was attenuated (p<0.05) in women at 15 min and men at 30 min (p<0.05) post-exercise with a significant time by sex interaction (p<0.05). WIA (1st peak) was correlated (p<0.05) to ∆Ew in both sexes before and 15 min post-exercise, but cPWV was only associated with ∆Ew in men at 30 min post-exercise. We conclude that both sexes decrease ∆Ew after maximal exercise, but vascular and ventricular changes associated with the attenuation of ∆Ew are not uniform between sexes. © Georg Thieme Verlag KG Stuttgart · New York.

Application of mathematical modelling for assessing the biological half-times of chromium and nickel in field studies.

PubMed Central

Tossavainen, A; Nurminen, M; Mutanen, P; Tola, S

1980-01-01

The biological half-times of urinary chromium and nickel excretion and plasma nickel concentration were calculated for four welders and four electroplaters. A linear one-compartment kinetic model gave estimates of the half-times ranging from 15 to 41 hours for chromium in urine, from 17 to 39 hours for nickel in urine, and from 20 to 34 hours for nickel in plasma. The model allows a precise description to be made of a worker's state of exposure as affected by a varying concentration of the metals in the air. PMID:7426481

Exercise Training at Maximal Fat Oxidation Intensity for Older Women with Type 2 Diabetes.

PubMed

Tan, Sijie; Du, Ping; Zhao, Wanting; Pang, Jiaqi; Wang, Jianxiong

2018-05-01

The purpose of this study was to investigate the pleiotropic effects of 12 weeks of supervised exercise training at maximal fat oxidation (FATmax) intensity on body composition, lipid profile, glycemic control, insulin sensitivity and serum adipokine levels in older women with type 2 diabetes. Thirty-one women with type 2 diabetes, aged 60 to 69 years, were randomly allocated into exercise and control groups. Body composition, lipid profile, blood glucose, insulin resistance and serum leptin and adiponectin concentrations were measured before and after the intervention. Exercise group (n=16) walked at individualized FATmax intensities for 1 h/day for 3 days/week over 12 weeks. No dietary intervention was introduced during the experimental period. Maximal fat oxidation rate was 0.37±0.10 g/min, and occurred at 37.3±7.3% of the estimated VO 2 max. Within the exercise group, significant improvements were observed for most of the measured variables compared to non-exercising controls; in particular, the FATmax program reduced body fat% (p<0.001), visceral fat% (p<0.001), and insulin resistance (p<0.001). There was no significant change in daily energy intake for all participants during the intervention period. These results suggest that individualized FATmax training is an effective exercise training intensity for managing type 2 diabetes in older women. © Georg Thieme Verlag KG Stuttgart · New York.

Activation of M1 muscarinic receptors triggers transmitter release from rat sympathetic neurons through an inhibition of M-type K+ channels.

PubMed

Lechner, Stefan G; Mayer, Martina; Boehm, Stefan

2003-12-15

Acetylcholine has long been known to excite sympathetic neurons via M1 muscarinic receptors through an inhibition of M-currents. Nevertheless, it remained controversial whether activation of muscarinic receptors is also sufficient to trigger noradrenaline release from sympathetic neurons. In primary cultures of rat superior cervical ganglia, the muscarinic agonist oxotremorine M inhibited M-currents with half-maximal effects at 1 microM and induced the release of previously incorporated [3H]noradrenaline with half-maximal effects at 10 microM. This latter action was not affected by the nicotinic antagonist mecamylamine which, however, abolished currents through nicotinic receptors elicited by high oxotremorine M concentrations. Ablation of the signalling cascades linked to inhibitory G proteins by pertussis toxin potentiated the release stimulating effect of oxotremorine M, and the half-maximal concentration required to stimulate noradrenaline release was decreased to 3 microM. Pirenzepine antagonized the inhibition of M-currents and the induction of release by oxotremorine M with identical apparent affinity, and both effects were abolished by the muscarinic toxin 7. These results indicate that one muscarinic receptor subtype, namely M1, mediates these two effects. Retigabine, which enhances M-currents, abolished the release induced by oxotremorine M, but left electrically induced release unaltered. Moreover, retigabine shifted the voltage-dependent activation of M-currents by about 20 mV to more negative potentials and caused 20 mV hyperpolarisations of the membrane potential. In the absence of retigabine, oxotremorine M depolarised the neurons and elicited action potential discharges in 8 of 23 neurons; in its presence, oxotremorine M still caused equal depolarisations, but always failed to trigger action potentials. Action potential waveforms caused by current injection were not affected by retigabine. These results indicate that the inhibition of M-currents is

External radiation exposure, excretion, and effective half-life in 177Lu-PSMA-targeted therapies.

PubMed

Kurth, J; Krause, B J; Schwarzenböck, S M; Stegger, L; Schäfers, M; Rahbar, K

2018-04-12

Prostate-specific membrane antigen (PSMA)-targeted therapy with 177 Lu-PSMA-617 is a therapeutic option for patients with metastatic castration-resistant prostate cancer (mCRPC). To optimize the therapy procedure, it is necessary to determine relevant parameters to define radiation protection and safety necessities. Therefore, this study aimed at estimating the ambient radiation exposure received by the patient. Moreover, the excreted activity was quantified. In total, 50 patients with mCRPC and treated with 177 Lu-PSMA-617 (mean administered activity 6.3 ± 0.5 GBq) were retrospectively included in a bi-centric study. Whole-body dose rates were measured at a distance of 2 m at various time points after application of 177 Lu-PSMA-617, and effective half-lives for different time points were calculated and compared. Radiation exposure to the public was approximated using the dose integral. For the estimation of the excreted activity, whole body measurements of 25 patients were performed at 7 time points. Unbound 177 Lu-PSMA-617 was rapidly cleared from the body. After 4 h, approximately 50% and, after 12 h, approximately 70% of the administered activity were excreted, primarily via urine. The mean dose rates were the following: 3.6 ± 0.7 μSv/h at 2 h p. i., 1.6 ± 0.6 μSv/h at 24 h, 1.1 ± 0.5 μSv/h at 48 h, and 0.7 ± 0.4 μSv/h at 72 h. The mean effective half-life of the cohort was 40.5 ± 9.6 h (min 21.7 h; max 85.7 h). The maximum dose to individual members of the public per treatment cycle was ~ 250 ± 55 μSv when the patient was discharged from the clinic after 48 h and ~ 190 ± 36 μSv when the patient was discharged after 72 h. In terms of the radiation exposure to the public, 177 Lu-PSMA is a safe option of radionuclide therapy. As usually four (sometimes more) cycles of the therapy are performed, it must be conducted in a way that ensures that applicable legal requirements can be followed. In

Effects of exercise-induced muscle damage on resting metabolic rate, sub-maximal running and post-exercise oxygen consumption.

PubMed

Burt, Dean Gareth; Lamb, Kevin; Nicholas, Ceri; Twist, Craig

2014-01-01

Exercise-induced muscle damage (EIMD), described as the acute weakness of the musculature after unaccustomed eccentric exercise, increases oxidative metabolism at rest and during endurance exercise. However, it is not known whether oxygen uptake during recovery from endurance exercise is increased when experiencing symptoms of EIMD. Therefore, the purpose of this study was to investigate the effects of EIMD on physiological and metabolic responses before, during and after sub-maximal running. After a 12 h fast, eight healthy male participants completed baseline measurements comprising resting metabolic rate (RMR), indirect markers of EIMD, 10 min of sub-maximal running and 30 min of recovery to ascertain excess post-exercise oxygen consumption (EPOC). Measurements were then repeated at 24 and 48 h after 100 Smith-machine squats. Data analysis revealed significant (P<0.05) increases in muscle soreness and creatine kinase (CK) and decreases in peak knee extensor torque at 24 and 48 h after squatting exercise. Moreover, RMR, physiological, metabolic and perceptual responses during sub-maximal running and EPOC were increased in the two days after squatting exercise (P<0.05). It is suggested that the elevated RMR was a consequence of a raised energy requirement for the degradation and resynthesis of damaged muscle fibres. The increased oxygen demand during sub-maximal running after muscle damage was responsible for the increase in EPOC. Individuals engaging in unaccustomed resistance exercise that results in muscle damage should be mindful of the increases in resting energy expenditure and increased metabolic demand to exercise in the days that follow.

Entanglement Concentration for Arbitrary Four-Photon Cluster State Assisted with Single Photons

NASA Astrophysics Data System (ADS)

Zhao, Sheng-Yang; Cai, Chun; Liu, Jiong; Zhou, Lan; Sheng, Yu-Bo

2016-02-01

We present an entanglement concentration protocol (ECP) to concentrate arbitrary four-photon less-entangled cluster state into maximally entangled cluster state. Different from other ECPs for cluster state, we only exploit the single photon as auxiliary, which makes this protocol feasible and economic. In our ECP, the concentrated maximally entangled state can be retained for further application and the discarded state can be reused for a higher success probability. This ECP works with the help of cross-Kerr nonlinearity and conventional photon detectors. This ECP may be useful in future one-way quantum computation.

Effects of management factors on the concentration of a high molecular weight polysaccharide fraction from log-grown shiitake mushrooms (Lentinula edodes (Berk.) Pegler).

PubMed

Kimmons, Tom E; Phillips, Mark; Brauer, David

2010-04-14

Shiitake mushrooms have a reputation as a healthy food. Growers may be able to use the presence of health-promoting constituents as a marketing tool to promote sales of their products for premium prices. There are few reports on the effects of management protocols for log-grown shiitakes on the concentrations of constituents to guide growers. This paper summarizes several studies that examined the effects of shiitake strains, mushroom cap development, and length of saprophytic association on the concentrations of a high molecular weight polysaccharide fraction that includes lentinan (HMWP). Concentrations of HMWP in mushrooms varied as much as 8-fold during fruiting among the 12 strains tested in these studies. Results also indicate that the concentrations of HMWP in shiitake mushrooms are influenced by the fungal phenotype and the characteristics of the environment. General trends showed that (1) mushrooms harvested at more immature stages of development (during bud break or before veil break) tended to have higher concentrations of HMWP and (2) the initial harvests of mushrooms from an inoculated log tend to have higher concentrations of HMWP than subsequent harvests. Results suggest that growers interested in maximizing the HMWP content of their mushrooms should use shiitake strains NN-430 and 569-430.

Porcine malignant hyperthermia susceptibility: hypersensitive calcium-release mechanism of skeletal muscle sarcoplasmic reticulum.

PubMed Central

O'Brien, P J

1986-01-01

This study tested the hypothesis that calcium-release from sarcoplasmic reticulum isolated from malignant hyperthermia swine had abnormal concentration-dependency on release modulators. Halothane stimulated half-maximal calcium-release at similar concentrations for malignant hyperthermia and control sarcoplasmic reticulum (0.10 +/- 0.04 mM). However, concentrations causing half-maximal calcium-release were lower for malignant hyperthermia sarcoplasmic reticulum (P less than 0.001) by an order of magnitude for Ca2+ (28.1 +/- 8.3 versus 1.23 +/- 0.45 nM), adenosine triphosphate (0.33 +/- 0.09 versus 0.023 +/- 0.014 mM) and caffeine (7.79 +/- 1.56 versus 0.80 +/- 0.44 mM). Half-maximal inhibition by Mg2+ occurred at threefold higher concentrations for malignant hyperthermia sarcoplasmic reticulum (0.23 +/- 0.02 versus 0.78 +/- 0.17 mM). The Ca2+-sensitivity curves for calcium-release by sarcoplasmic reticulum isolated from heterozygotes for the malignant hyperthermia-defect were indistinguishable from the averages of the curves for controls and malignant hyperthermia-homozygotes. Results of this study suggest that malignant hyperthermia is initiated due to a hypersensitive calcium-release mechanism which is inherited in an autosomal, codominant pattern and may be diagnosed using calcium-release sensitivity-tests on isolated sarcoplasmic reticulum. Images Fig. 1. PMID:3742367

Maximal yields from multispecies fisheries systems: rules for systems with multiple trophic levels.

PubMed

Matsuda, Hiroyuki; Abrams, Peter A

2006-02-01

Increasing centralization of the control of fisheries combined with increased knowledge of food-web relationships is likely to lead to attempts to maximize economic yield from entire food webs. With the exception of predator-prey systems, we lack any analysis of the nature of such yield-maximizing strategies. We use simple food-web models to investigate the nature of yield- or profit-maximizing exploitation of communities including two types of three-species food webs and a variety of six-species systems with as many as five trophic levels. These models show that, for most webs, relatively few species are harvested at equilibrium and that a significant fraction of the species is lost from the web. These extinctions occur for two reasons: (1) indirect effects due to harvesting of species that had positive effects on the extinct species, and (2) intentional eradication of species that are not themselves valuable, but have negative effects on more valuable species. In most cases, the yield-maximizing harvest involves taking only species from one trophic level. In no case was an unharvested top predator part of the yield-maximizing strategy. Analyses reveal that the existence of direct density dependence in consumers has a large effect on the nature of the optimal harvest policy, typically resulting in harvest of a larger number of species. A constraint that all species must be retained in the system (a "constraint of biodiversity conservation") usually increases the number of species and trophic levels harvested at the yield-maximizing policy. The reduction in total yield caused by such a constraint is modest for most food webs but can be over 90% in some cases. Independent harvesting of species within the web can also cause extinctions but is less likely to do so.

Influence of Tm+3 concentration on the non-linear optical effects of the BiB3O6 : Tm3+ glass nanoparticle-doped polymer

NASA Astrophysics Data System (ADS)

Majchrowski, A.; Ebothe, J.; Ozga, K.; Kityk, I. V.; Reshak, A. H.; Lukasiewicz, T.; Brik, M. G.

2010-01-01

It is shown that BiB3O6 : Tm3+ glass nanoparticles incorporated into polymethylmethacrylate (PMMA) and polycarbonate (PC) polymer matrices show good second-order susceptibilities under bicolour coherent laser treatment. It is found that only during incorporation into highly polarized PC matrices could one observe an enhancement of the second-order susceptibilities with increasing laser treated power densities. The main increase is observed for all samples at power densities equal to about 0.4 GW cm-2. After passing this value there is a saturation of the output susceptibilities and even an abrupt decrease. The most striking feature is the achievement of second-order susceptibilities equal to about 5 pm V-1 for samples containing 4% nanoparticle (NP) content in the PC matrix. A further increase in the NP concentration to 6% leads to a decrease in susceptibility to 15%. In the case of PMMA matrices these changes do not exceed the background. The same situation is present for the pure BIBO and low-doped Tm materials. The effect is maximal for a low concentration of Tm—about 0.75%. In the case of bulk glasses the intensity dependences of the second-harmonic generation unambiguously show that the achieved maximal values of second-order susceptibilities do not exceed 3 pm V-1 for 0.5% Tm concentration.

Dietary 2-oxoglutarate prevents bone loss caused by neonatal treatment with maximal dexamethasone dose

PubMed Central

Tomaszewska, Ewa; Muszyński, Siemowit; Blicharski, Tomasz; Pierzynowski, Stefan G

2017-01-01

Synthetic glucocorticoids (GCs) are widely used in the variety of dosages for treatment of premature infants with chronic lung disease, respiratory distress syndrome, allergies, asthma, and other inflammatory and autoimmune conditions. Yet, adverse effects such as glucocorticoid-induced osteoporosis and growth retardation are recognized. Conversely, 2-oxoglutarate (2-Ox), a precursor of glutamine, glutamate, and collagen amino acids, exerts protective effects on bone development. Our aim was to elucidate the effect of dietary administered 2-Ox on bone loss caused by neonatal treatment with clinically relevant maximal therapeutic dexamethasone (Dex) dose. Long bones of neonatal female piglets receiving Dex, Dex+2-Ox, or untreated were examined through measurements of mechanical properties, density, mineralization, geometry, histomorphometry, and histology. Selected hormones, bone turnover, and growth markers were also analyzed. Neonatal administration of clinically relevant maximal dose of Dex alone led to over 30% decrease in bone mass and the ultimate strength (P < 0.001 for all). The length (13 and 7% for femur and humerus, respectively) and other geometrical parameters (13–45%) decreased compared to the control (P < 0.001 for all). Dex impaired bone growth and caused hormonal imbalance. Dietary 2-Ox prevented Dex influence and vast majority of assessed bone parameters were restored almost to the control level. Piglets receiving 2-Ox had heavier, denser, and stronger bones; higher levels of growth hormone and osteocalcin concentration; and preserved microarchitecture of trabecular bone compared to the Dex group. 2-Ox administered postnatally had a potential to maintain bone structure of animals simultaneously treated with maximal therapeutic doses of Dex, which, in our opinion, may open up a new opportunity in developing combined treatment for children treated with GCs. Impact statement The present study has showed, for the first time, that dietary 2

Reliability of time-to-exhaustion and selected psycho-physiological variables during constant-load cycling at the maximal lactate steady-state.

PubMed

Faude, Oliver; Hecksteden, Anne; Hammes, Daniel; Schumacher, Franck; Besenius, Eric; Sperlich, Billy; Meyer, Tim

2017-02-01

The maximal lactate steady-state (MLSS) is frequently assessed for prescribing endurance exercise intensity. Knowledge of the intra-individual variability of the MLSS is important for practical application. To date, little is known about the reliability of time-to-exhaustion and physiological responses to exercise at MLSS. Twenty-one healthy men (age, 25.2 (SD 3.3) years; height, 1.83 (0.06) m; body mass, 78.9 (8.9) kg; maximal oxygen uptake, 57.1 (10.7) mL·min -1 ·kg -1 ) performed 1 incremental exercise test, and 2 constant-load tests to determine MLSS intensity. Subsequently, 2 open-end constant-load tests (MLSS 1 and 2) at MLSS intensity (3.0 (0.7) W·kg -1 , 76% (10%) maximal oxygen uptake) were carried out. During the tests, blood lactate concentrations, heart rate, ratings of perceived exertion (RPE), variables of gas exchange, and core body temperature were determined. Time-to-exhaustion was 50.8 (14.0) and 48.2 (16.7) min in MLSS 1 and 2 (mean change: -2.6 (95% confidence interval: -7.8, 2.6)), respectively. The coefficient of variation (CV) was high for time-to-exhaustion (24.6%) and for mean (4.8 (1.2) mmol·L -1 ) and end (5.4 (1.7) mmol·L -1 ) blood lactate concentrations (15.7% and 19.3%). The CV of mean exercise values for all other parameters ranged from 1.4% (core temperature) to 8.3% (ventilation). At termination, the CVs ranged from 0.8% (RPE) to 11.8% (breathing frequency). The low reliability of time-to-exhaustion and blood lactate concentration at MLSS indicates that the precise individual intensity prescription may be challenging. Moreover, the obtained data may serve as reference to allow for the separation of intervention effects from random variation in our sample.

Structured light generation by magnetic metamaterial half-wave plates at visible wavelength

NASA Astrophysics Data System (ADS)

Zeng, Jinwei; Luk, Ting S.; Gao, Jie; Yang, Xiaodong

2017-12-01

Metamaterial or metasurface unit cells functioning as half-wave plates play an essential role for realizing ideal Pancharatnam-Berry phase optical elements capable of tailoring light phase and polarization as desired. Complex light beam manipulation through these metamaterials or metasurfaces unveils new dimensions of light-matter interactions for many advances in diffraction engineering, beam shaping, structuring light, and holography. However, the realization of metamaterial or metasurface half-wave plates in visible spectrum range is still challenging mainly due to its specific requirements of strong phase anisotropy with amplitude isotropy in subwavelength scale. Here, we propose magnetic metamaterial structures which can simultaneously exploit the electric field and magnetic field of light for achieving the nanoscale half-wave plates at visible wavelength. We design and demonstrate the magnetic metamaterial half-wave plates in linear grating patterns with high polarization conversion purity in a deep subwavelength thickness. Then, we characterize the equivalent magnetic metamaterial half-wave plates in cylindrical coordinate as concentric-ring grating patterns, which act like an azimuthal half-wave plate and accordingly exhibit spatially inhomogeneous polarization and phase manipulations including spin-to-orbital angular momentum conversion and vector beam generation. Our results show potentials for realizing on-chip beam converters, compact holograms, and many other metamaterial devices for structured light beam generation, polarization control, and wavefront manipulation.

On Adaptation, Maximization, and Reinforcement Learning among Cognitive Strategies

ERIC Educational Resources Information Center

Erev, Ido; Barron, Greg

2005-01-01

Analysis of binary choice behavior in iterated tasks with immediate feedback reveals robust deviations from maximization that can be described as indications of 3 effects: (a) a payoff variability effect, in which high payoff variability seems to move choice behavior toward random choice; (b) underweighting of rare events, in which alternatives…

Are all maximally entangled states pure?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cavalcanti, D.; Brandao, F.G.S.L.; Terra Cunha, M.O.

We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.

Are all maximally entangled states pure?

NASA Astrophysics Data System (ADS)

Cavalcanti, D.; Brandão, F. G. S. L.; Terra Cunha, M. O.

2005-10-01

We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.

Visual half-field presentations of incongruent color words: effects of gender and handedness.

PubMed

Franzon, M; Hugdahl, K

1986-09-01

Right-handed (dextral) and left-handed (sinistral) males and females (N = 15) were compared for language lateralization in a visual half-field (VHF) incongruent color-words paradigm. The paradigm consists of repeated brief (less than 200 msec) presentations of color-words written in an incongruent color. Presentations are either to the right or to the left of center fixation. The task of the subject is to report the color the word is written in on each trial, ignoring the color-word. Color-bars and congruent color-words were used as control stimuli. Vocal reaction time (VRT) and error frequency were used as dependent measures. The logic behind the paradigm is that incongruent color-words should lead to a greater cognitive conflict when presented in the half-field contralateral to the dominant hemisphere. The results showed significantly longer VRTs in the right half-field for the dextral subjects. Furthermore, significantly more errors were observed in the male dextral group when the incongruent stimuli were presented in the right half-field. There was a similar trend in the data for the sinistral males. No differences between half-fields were observed for the female groups. It is concluded that the present results strengthen previous findings from our laboratory (Hugdahl and Franzon, 1985) that the incongruent color-words paradigm is a useful non-invasive technique for the study of lateralization in the intact brain.

LibHalfSpace: A C++ object-oriented library to study deformation and stress in elastic half-spaces

NASA Astrophysics Data System (ADS)

Ferrari, Claudio; Bonafede, Maurizio; Belardinelli, Maria Elina

2016-11-01

The study of deformation processes in elastic half-spaces is widely employed for many purposes (e.g. didactic, scientific investigation of real processes, inversion of geodetic data, etc.). We present a coherent programming interface containing a set of tools designed to make easier and faster the study of processes in an elastic half-space. LibHalfSpace is presented in the form of an object-oriented library. A set of well known and frequently used source models (Mogi source, penny shaped horizontal crack, inflating spheroid, Okada rectangular dislocation, etc.) are implemented to describe the potential usage and the versatility of the library. The common interface given to library tools enables us to switch easily among the effects produced by different deformation sources that can be monitored at the free surface. Furthermore, the library also offers an interface which simplifies the creation of new source models exploiting the features of object-oriented programming (OOP). These source models can be built as distributions of rectangular boundary elements. In order to better explain how new models can be deployed some examples are included in the library.

Ischemic preconditioning of the muscle improves maximal exercise performance but not maximal oxygen uptake in humans.

PubMed

Crisafulli, Antonio; Tangianu, Flavio; Tocco, Filippo; Concu, Alberto; Mameli, Ombretta; Mulliri, Gabriele; Caria, Marcello A

2011-08-01

Brief episodes of nonlethal ischemia, commonly known as "ischemic preconditioning" (IP), are protective against cell injury induced by infarction. Moreover, muscle IP has been found capable of improving exercise performance. The aim of the study was the comparison of standard exercise performances carried out in normal conditions with those carried out following IP, achieved by brief muscle ischemia at rest (RIP) and after exercise (EIP). Seventeen physically active, healthy male subjects performed three incremental, randomly assigned maximal exercise tests on a cycle ergometer up to exhaustion. One was the reference (REF) test, whereas the others were performed after the RIP and EIP sessions. Total exercise time (TET), total work (TW), and maximal power output (W(max)), oxygen uptake (VO(2max)), and pulmonary ventilation (VE(max)) were assessed. Furthermore, impedance cardiography was used to measure maximal heart rate (HR(max)), stroke volume (SV(max)), and cardiac output (CO(max)). A subgroup of volunteers (n = 10) performed all-out tests to assess their anaerobic capacity. We found that both RIP and EIP protocols increased in a similar fashion TET, TW, W(max), VE(max), and HR(max) with respect to the REF test. In particular, W(max) increased by ∼ 4% in both preconditioning procedures. However, preconditioning sessions failed to increase traditionally measured variables such as VO(2max), SV(max,) CO(max), and anaerobic capacity(.) It was concluded that muscle IP improves performance without any difference between RIP and EIP procedures. The mechanism of this effect could be related to changes in fatigue perception.

Gaussian maximally multipartite-entangled states

NASA Astrophysics Data System (ADS)

Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio

2009-12-01

We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .

Improved half-metallic gap of zincblende half-metal superlattices with the Tran-Blaha modified Becke-Johnson density functional

NASA Astrophysics Data System (ADS)

Guo, San-Dong

2016-08-01

Binary transition-metal pnictides and chalcogenides half-metallic ferromagnetic materials with zincblende structure, being compatible with current semiconductor technology, can be used to make high-performance spintronic devices. Here, we investigate electronic structures and magnetic properties of composite structure ((CrX)2 /(YX)2 (X=As, Sb; Se, Te and Y=Ga; Zn) superlattices) of zincblende half-metallic ferromagnetism and semiconductor by using Tran and Blaha's modified Becke and Johnson (mBJ) exchange potential. Calculated results show that they all are half-metallic ferromagnets with both generalized gradient approximation (GGA) and mBJ, and the total magnetic moment per formula unit follows a Slater-Pauling-like "rule of 8". The key half-metallic gaps by using mBJ are enhanced with respect to GGA results, which is because mBJ makes the occupied minority-spin p-bands move toward lower energy, but toward higher energy for empty minority-spin Cr-d bands. When the spin-orbit coupling (SOC) is included, the spin polarization deviates from 100%, and a most reduced polarization of 98.3% for (CrSb)2 /(GaSb)2, which indicates that SOC has small effects, of the order of 1%, in the considered four kinds of superlattice.

Power converter for raindrop energy harvesting application: Half-wave rectifier

NASA Astrophysics Data System (ADS)

Izrin, Izhab Muhammad; Dahari, Zuraini

2017-10-01

Harvesting raindrop energy by capturing vibration from impact of raindrop have been explored extensively. Basically, raindrop energy is generated by converting the kinetic energy of raindrop into electrical energy by using polyvinylidene fluoride (PVDF) piezoelectric. In this paper, a power converter using half-wave rectifier for raindrop harvesting energy application is designed and proposed to convert damping alternating current (AC) generated by PVDF into direct current (DC). This research presents parameter analysis of raindrop simulation used in the experiment and resistive load effect on half-wave rectifier converter. The experiment is conducted by using artificial raindrop from the height of 1.3 m to simulate the effect of different resistive load on the output of half-wave rectifier converter. The results of the 0.68 MΩ resistive load showed the best performance of the half-wave rectifier converter used in raindrop harvesting energy system, which generated 3.18 Vaverage. The peak instantaneous output generated from this experiment is 15.36 µW.

Effects of Hydration and Calcium Supplementation on Urine Calcium Concentration in Healthy Postmenopausal Women.

PubMed

Harris, Susan S; Dawson-Hughes, Bess

2015-01-01

The aim of this study was to determine whether calcium supplementation, compared with placebo, increases urine calcium concentrations to levels indicative of increased renal stone risk, and the role that fluid intake, as indicated by urine volume, may play in mitigating this risk. This is a secondary analysis of data from a randomized placebo-controlled trial of 500 mg/d calcium supplementation to prevent bone loss. Subjects were 240 white postmenopausal women age 40 to 70 years in good general health. Effects of supplementation on 1-year changes in 24h urine calcium concentration and urine volume were examined. Both treatment group and urine volume were strong independent predictors of urine calcium concentration (p < 0.001). Among subjects with urine volume under 2 L/24 h, more than half of placebo subjects were at lowest risk for renal stones compared with less than 35% of calcium-supplemented subjects. Among those with higher urine volumes, all placebo subjects and more than 80% of calcium supplemented subjects were at lowest risk. The increased risk of renal stones with calcium supplement use may be largely eliminated with adequate fluid intake, but older adults may not spontaneously consume adequate fluids to minimize this risk and should be counseled to do so.

Field performance measurements of half-facepiece respirators: steel mill operations.

PubMed

Myers, W R; Zhuang, Z

1998-11-01

Ambient and in-facepiece samples to evaluate the protection provided by negative-pressure, half-facepiece respirators were collected on workers in different areas of a steel mill including a sinter plant and a basic oxygen process shop. Protection was assessed by workplace protection factors (WPF). All the in-facepiece concentrations were dramatically less than the corresponding ambient concentration levels or permissible exposure limits. The geometric mean (GM) ambient and in-facepiece concentrations of iron were found to vary among tasks. Significant differences were also found to occur between the GM ambient exposure levels in which some of the respirators were used. Significant differences in respirator performance as measured by WPF or in-facepiece iron concentration were observed among different brands of respirators. For all job classifications and at all levels of airborne exposure, the fifth percentile estimates for the WPF distributions for each brand of respirator were all greater than 20.

Efavirenz directly modulates the oestrogen receptor and induces breast cancer cell growth.

PubMed

Sikora, M J; Rae, J M; Johnson, M D; Desta, Z

2010-10-01

Efavirenz-based HIV therapy is associated with breast hypertrophy and gynaecomastia. Here, we tested the hypothesis that efavirenz induces gynaecomastia through direct binding and modulation of the oestrogen receptor (ER). To determine the effect of efavirenz on growth, the oestrogen-dependent, ER-positive breast cancer cell lines MCF-7, T47D and ZR-75-1 were treated with efavirenz under oestrogen-free conditions in the presence or absence of the anti-oestrogen ICI 182,780. Cells treated with 17β-oestradiol in the absence or presence of ICI 182,780 served as positive and negative controls, respectively. Cellular growth was assayed using the crystal violet staining method and an in vitro receptor binding assay was used to measure the ER binding affinity of efavirenz. Efavirenz induced growth in MCF-7 cells with an estimated effective concentration for half-maximal growth (EC(50)) of 15.7 μM. This growth was reversed by ICI 182,780. Further, efavirenz binds directly to the ER [inhibitory concentration for half maximal binding (IC(50)) of ∼52 μM] at a roughly 1000-fold higher concentration than observed with 17β-oestradiol. Our data suggest that efavirenz-induced gynaecomastia may be caused, at least in part, by drug-induced ER activation in breast tissues.

7 CFR 51.2295 - Half kernel.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Half kernel. 51.2295 Section 51.2295 Agriculture... Standards for Shelled English Walnuts (Juglans Regia) Definitions § 51.2295 Half kernel. Half kernel means the separated half of a kernel with not more than one-eighth broken off. ...

Hairy black hole stability in AdS, quantum mechanics on the half-line and holography

NASA Astrophysics Data System (ADS)

Anabalón, Andrés; Astefanesei, Dumitru; Oliva, Julio

2015-10-01

We consider the linear stability of 4-dimensional hairy black holes with mixed boundary conditions in Anti-de Sitter spacetime. We focus on the mass of scalar fields around the maximally supersymmetric vacuum of the gauged N=8 supergravity in four dimensions, m 2 = -2 l -2. It is shown that the Schrödinger operator on the half-line, governing the S 2, H 2 or {{R}}^2 invariant mode around the hairy black hole, allows for non-trivial self-adjoint extensions and each of them corresponds to a class of mixed boundary conditions in the gravitational theory. Discarding the self-adjoint extensions with a negative mode impose a restriction on these boundary conditions. The restriction is given in terms of an integral of the potential in the Schrödinger operator resembling the estimate of Simon for Schrödinger operators on the real line. In the context of AdS/CFT duality, our result has a natural interpretation in terms of the field theory dual effective potential.

Capillary reference half-cell

DOEpatents

Hall, Stephen H.

1996-01-01

The present invention is a reference half-cell electrode wherein intermingling of test fluid with reference fluid does not affect the performance of the reference half-cell over a long time. This intermingling reference half-cell may be used as a single or double junction submersible or surface reference electrode. The intermingling reference half-cell relies on a capillary tube having a first end open to reference fluid and a second end open to test fluid wherein the small diameter of the capillary tube limits free motion of fluid within the capillary to diffusion. The electrode is placed near the first end of the capillary in contact with the reference fluid. The method of operation of the present invention begins with filling the capillary tube with a reference solution. After closing the first end of the capillary, the capillary tube may be fully submerged or partially submerged with the second open end inserted into test fluid. Since the electrode is placed near the first end of the capillary, and since the test fluid may intermingle with the reference fluid through the second open end only by diffusion, this intermingling capillary reference half-cell provides a stable voltage potential for long time periods.

Capillary reference half-cell

DOEpatents

Hall, S.H.

1996-02-13

The present invention is a reference half-cell electrode wherein intermingling of test fluid with reference fluid does not affect the performance of the reference half-cell over a long time. This intermingling reference half-cell may be used as a single or double junction submersible or surface reference electrode. The intermingling reference half-cell relies on a capillary tube having a first end open to reference fluid and a second end open to test fluid wherein the small diameter of the capillary tube limits free motion of fluid within the capillary to diffusion. The electrode is placed near the first end of the capillary in contact with the reference fluid. The method of operation of the present invention begins with filling the capillary tube with a reference solution. After closing the first end of the capillary, the capillary tube may be fully submerged or partially submerged with the second open end inserted into test fluid. Since the electrode is placed near the first end of the capillary, and since the test fluid may intermingle with the reference fluid through the second open end only by diffusion, this intermingling capillary reference half-cell provides a stable voltage potential for long time periods. 11 figs.

Activity versus outcome maximization in time management.

PubMed

Malkoc, Selin A; Tonietto, Gabriela N

2018-04-30

Feeling time-pressed has become ubiquitous. Time management strategies have emerged to help individuals fit in more of their desired and necessary activities. We provide a review of these strategies. In doing so, we distinguish between two, often competing, motives people have in managing their time: activity maximization and outcome maximization. The emerging literature points to an important dilemma: a given strategy that maximizes the number of activities might be detrimental to outcome maximization. We discuss such factors that might hinder performance in work tasks and enjoyment in leisure tasks. Finally, we provide theoretically grounded recommendations that can help balance these two important goals in time management. Published by Elsevier Ltd.

Contractile effects and binding properties of endothelins/sarafotoxins in the guinea pig ileum.

PubMed

Wollberg, Z; Bdolah, A; Galron, R; Sokolovsky, M; Kochva, E

1991-05-30

Seven of the eight known isopeptides of the endothelin/sarafotoxin (ET/SRTX) family were tested on the isolated guinea pig ileum and found to cause a concentration-dependent increase in basal tone. The rate or the amplitude of the spontaneous rhythmic contractions of the ileal smooth muscle were essentially not affected by any of the peptides. The maximum contraction elicited by vasoactive intestinal contractor (VIC) was slightly stronger than that induced by endothelin-1 (ET-1) or sarafotoxin-b (SRTX-b), and significantly stronger than the maximal contractions elicited by sarafotoxin-a (SRTX-a), sarafotoxin-c (SRTX-c), or endothelin-3 (ET-3). Sarafotoxin-d (SRTX-d) caused, essentially, no contraction but a rather marked relaxation. The potencies of the various peptides to induce the increase in tension, in terms of EC50 values (cumulative effective concentrations that induce half-maximum response), ranged between 6 and 95 nM depending on the peptide. VIC, ET-1, SRTX-b and SRTX-a had similar potencies and were significantly more potent than SRTX-c and ET-3. A high concentration of SRTX-b elicited no additional response when applied to the organ bath after one of the other peptides had shown a maximal effect. Binding experiments with ileal membranes revealed similar binding properties for the various peptides. Competition with iodinated SRTX-b showed no meaningful differences between the various peptides. It is concluded that all the ET/SRTX peptides compete for the same receptor subtype in the ileum. In terms of efficacy, VIC can be considered as a full agonist of this receptor, SRTX-d is probably an antagonist, while all the other peptides behave as partial agonists.

Black disk, maximal Odderon and unitarity

NASA Astrophysics Data System (ADS)

Khoze, V. A.; Martin, A. D.; Ryskin, M. G.

2018-05-01

We argue that the so-called maximal Odderon contribution breaks the 'black disk' behavior of the asymptotic amplitude, since the cross section of the events with Large Rapidity Gaps grows faster than the total cross section. That is the 'maximal Odderon' is not consistent with unitarity.

Energy conservation and maximal entropy production in enzyme reactions.

PubMed

Dobovišek, Andrej; Vitas, Marko; Brumen, Milan; Fajmut, Aleš

2017-08-01

A procedure for maximization of the density of entropy production in a single stationary two-step enzyme reaction is developed. Under the constraints of mass conservation, fixed equilibrium constant of a reaction and fixed products of forward and backward enzyme rate constants the existence of maximum in the density of entropy production is demonstrated. In the state with maximal density of entropy production the optimal enzyme rate constants, the stationary concentrations of the substrate and the product, the stationary product yield as well as the stationary reaction flux are calculated. The test, whether these calculated values of the reaction parameters are consistent with their corresponding measured values, is performed for the enzyme Glucose Isomerase. It is found that calculated and measured rate constants agree within an order of magnitude, whereas the calculated reaction flux and the product yield differ from their corresponding measured values for less than 20 % and 5 %, respectively. This indicates that the enzyme Glucose Isomerase, considered in a non-equilibrium stationary state, as found in experiments using the continuous stirred tank reactors, possibly operates close to the state with the maximum in the density of entropy production. Copyright © 2017 Elsevier B.V. All rights reserved.

An Efficient and Effective Design of InP Nanowires for Maximal Solar Energy Harvesting

NASA Astrophysics Data System (ADS)

Wu, Dan; Tang, Xiaohong; Wang, Kai; He, Zhubing; Li, Xianqiang

2017-11-01

Solar cells based on subwavelength-dimensions semiconductor nanowire (NW) arrays promise a comparable or better performance than their planar counterparts by taking the advantages of strong light coupling and light trapping. In this paper, we present an accurate and time-saving analytical design for optimal geometrical parameters of vertically aligned InP NWs for maximal solar energy absorption. Short-circuit current densities are calculated for each NW array with different geometrical dimensions under solar illumination. Optimal geometrical dimensions are quantitatively presented for single, double, and multiple diameters of the NW arrays arranged both squarely and hexagonal achieving the maximal short-circuit current density of 33.13 mA/cm2. At the same time, intensive finite-difference time-domain numerical simulations are performed to investigate the same NW arrays for the highest light absorption. Compared with time-consuming simulations and experimental results, the predicted maximal short-circuit current densities have tolerances of below 2.2% for all cases. These results unambiguously demonstrate that this analytical method provides a fast and accurate route to guide high performance InP NW-based solar cell design.

Optimization of an incubation step to maximize sulforaphane content in pre-processed broccoli.

PubMed

Mahn, Andrea; Pérez, Carmen

2016-11-01

Sulforaphane is a powerful anticancer compound, found naturally in food, which comes from the hydrolysis of glucoraphanin, the main glucosinolate of broccoli. The aim of this work was to maximize sulforaphane content in broccoli by designing an incubation step after subjecting broccoli pieces to an optimized blanching step. Incubation was optimized through a Box-Behnken design using ascorbic acid concentration, incubation temperature and incubation time as factors. The optimal incubation conditions were 38 °C for 3 h and 0.22 mg ascorbic acid per g fresh broccoli. The maximum sulforaphane concentration predicted by the model was 8.0 µmol g -1 , which was confirmed experimentally yielding a value of 8.1 ± 0.3 µmol g -1 . This represents a 585% increase with respect to fresh broccoli and a 119% increase in relation to blanched broccoli, equivalent to a conversion of 94% of glucoraphanin. The process proposed here allows maximizing sulforaphane content, thus avoiding artificial chemical synthesis. The compound could probably be isolated from broccoli, and may find application as nutraceutical or functional ingredient.

Maximal coherence and the resource theory of purity

NASA Astrophysics Data System (ADS)

Streltsov, Alexander; Kampermann, Hermann; Wölk, Sabine; Gessner, Manuel; Bruß, Dagmar

2018-05-01

The resource theory of quantum coherence studies the off-diagonal elements of a density matrix in a distinguished basis, whereas the resource theory of purity studies all deviations from the maximally mixed state. We establish a direct connection between the two resource theories, by identifying purity as the maximal coherence which is achievable by unitary operations. The states that saturate this maximum identify a universal family of maximally coherent mixed states. These states are optimal resources under maximally incoherent operations, and thus independent of the way coherence is quantified. For all distance-based coherence quantifiers the maximal coherence can be evaluated exactly, and is shown to coincide with the corresponding distance-based purity quantifier. We further show that purity bounds the maximal amount of entanglement and discord that can be generated by unitary operations, thus demonstrating that purity is the most elementary resource for quantum information processing.

Effects on Calculated Half-Widths and Shifts from the Line Coupling for Asymmetric-Top Molecules

NASA Technical Reports Server (NTRS)

Ma, Q.; Boulet, C.; Tipping, R. H.

2014-01-01

The refinement of the Robert-Bonamy formalism by considering the line coupling for linear molecules developed in our previous studies [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013); 140, 104304 (2014)] have been extended to asymmetric-top molecules. For H2O immersed in N2 bath, the line coupling selection rules applicable for the pure rotational band to determine whether two specified lines are coupled or not are established. Meanwhile, because the coupling strengths are determined by relative importance of off-diagonal matrix elements versus diagonal elements of the operator -iS1 -S2, quantitative tools are developed with which one is able to remove weakly coupled lines from consideration. By applying these tools, we have found that within reasonable tolerances, most of the H2O lines in the pure rotational band are not coupled. This reflects the fact that differences of energy levels of the H2O states are pretty large. But, there are several dozen strongly coupled lines and they can be categorized into different groups such that the line couplings occur only within the same groups. In practice, to identify those strongly coupled lines and to confine them into sub-linespaces are crucial steps in considering the line coupling. We have calculated half-widths and shifts for some groups, including the line coupling. Based on these calculations, one can conclude that for most of the H2O lines, it is unnecessary to consider the line coupling. However, for several dozens of lines, effects on the calculated half-widths from the line coupling are small, but remain noticeable and reductions of calculated half-widths due to including the line coupling could reach to 5%. Meanwhile, effects on the calculated shifts are very significant and variations of calculated shifts could be as large as 25%.

Effect of graphite oxide solution concentration on the properties of multilayer graphene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umar, Marjoni Imamora Ali; Yap, Chi Chin; Awang, Rozidawati

2013-11-27

This paper reports the influence of graphite oxide (GO) solution concentration on the optical and electrical properties of multilayer graphene (MLG) films. Graphene oxide (GrO) films were deposited on the glass substrates by spin coating aqueous solutions of GO with different concentrations (7, 8, 9, 10 and 11 mg/ml). The GrO films were then thermally reduced at temperature of 500°C in argon flow for half an hour to form MLG films. Both the transmittance and sheet resistance decreased with the GO concentration from 8 mg/ml to 9 mg/ml, possibly due to thicker and uniform coverage of MLG over the substrate.more » However, the transmittance and sheet resistance increased rapidly as the GO concentration reached 11 mg/ml, which can be attributed to poor film quality. The MLG film obtained at concentration of 10 mg/ml showed the highest transmittance/sheet resistance ratio with 69 % transmittance and sheet resistance of 292 ± 63 kΩ/sq. The optimum MLG film was utilized as counter electrode in dye sensitized solar cells based on ZnO nanorods.« less

The jet-disk symbiosis without maximal jets: 1D hydrodynamical jets revisited

NASA Astrophysics Data System (ADS)

Crumley, Patrick; Ceccobello, Chiara; Connors, Riley M. T.; Cavecchi, Yuri

2017-05-01

In this work we discuss the recent criticism by Zdziarski (2016, A&A, 586, A18) of the maximal jet model derived in Falcke & Biermann (1995, A&A, 293, 665). We agree with Zdziarski that in general a jet's internal energy is not bounded by its rest-mass energy density. We describe the effects of the mistake on conclusions that have been made using the maximal jet model and show when a maximal jet is an appropriate assumption. The maximal jet model was used to derive a 1D hydrodynamical model of jets in agnjet, a model that does multiwavelength fitting of quiescent/hard state X-ray binaries and low-luminosity active galactic nuclei. We correct algebraic mistakes made in the derivation of the 1D Euler equation and relax the maximal jet assumption. We show that the corrections cause minor differences as long as the jet has a small opening angle and a small terminal Lorentz factor. We find that the major conclusion from the maximal jet model, the jet-disk symbiosis, can be generally applied to astrophysical jets. We also show that isothermal jets are required to match the flat radio spectra seen in low-luminosity X-ray binaries and active galactic nuclei, in agreement with other works.

Campground marketing: the heavy-half strategy

Treesearch

Wilbur F. LaPage

1969-01-01

When we arrayed camping frequencies in order from the lowest to the highest number of days spent camping per year we found that half of the campers do much more than half of the camping. Campers in this heavy half consistently camp more, year after year, and are increasing their annual participation as well. Heavy-half campers have larger investments in camping...

Diurnal Variations in Maximal Oxygen Uptake.

ERIC Educational Resources Information Center

McClellan, Powell D.

A study attempted to determine if diurnal (daily cyclical) variations were present during maximal exercise. The subjects' (30 female undergraduate physical education majors) oxygen consumption and heart rates were monitored while they walked on a treadmill on which the grade was raised every minute. Each subject was tested for maximal oxygen…

A maximally particle-hole asymmetric spectrum emanating from a semi-Dirac point.

PubMed

Quan, Yundi; Pickett, Warren E

2018-02-21

Tight binding models have proven an effective means of revealing Dirac (massless) dispersion, flat bands (infinite mass), and intermediate cases such as the semi-Dirac (sD) dispersion. This approach is extended to a three band model that yields, with chosen parameters in a two-band limit, a closed line with maximally asymmetric particle-hole dispersion: infinite mass holes, zero mass particles. The model retains the sD points for a general set of parameters. Adjacent to this limiting case, hole Fermi surfaces are tiny and needle-like. A pair of large electron Fermi surfaces at low doping merge and collapse at half filling to a flat (zero energy) closed contour with infinite mass along the contour and enclosing no carriers on either side, while the hole Fermi surface has shrunk to a point at zero energy, also containing no carriers. The tight binding model is used to study several characteristics of the dispersion and density of states. The model inspired generalization of sD dispersion to a general  ±[Formula: see text] form, for which analysis reveals that both n and m must be odd to provide a diabolical point with topological character. Evolution of the Hofstadter spectrum of this three band system with interband coupling strength is presented and discussed.

When Does Reward Maximization Lead to Matching Law?

PubMed Central

Sakai, Yutaka; Fukai, Tomoki

2008-01-01

What kind of strategies subjects follow in various behavioral circumstances has been a central issue in decision making. In particular, which behavioral strategy, maximizing or matching, is more fundamental to animal's decision behavior has been a matter of debate. Here, we prove that any algorithm to achieve the stationary condition for maximizing the average reward should lead to matching when it ignores the dependence of the expected outcome on subject's past choices. We may term this strategy of partial reward maximization “matching strategy”. Then, this strategy is applied to the case where the subject's decision system updates the information for making a decision. Such information includes subject's past actions or sensory stimuli, and the internal storage of this information is often called “state variables”. We demonstrate that the matching strategy provides an easy way to maximize reward when combined with the exploration of the state variables that correctly represent the crucial information for reward maximization. Our results reveal for the first time how a strategy to achieve matching behavior is beneficial to reward maximization, achieving a novel insight into the relationship between maximizing and matching. PMID:19030101

Effect of increasing maximal aerobic exercise on serum muscles enzymes in professional field hockey players.

PubMed

Hazar, Muhsin; Otag, Aynur; Otag, Ilhan; Sezen, Mehmet; Sever, Ozan

2014-11-04

Exercise results in oxidative enzyme increase and micro-injuries in skeletal muscles. The aim of this study was to investigate the effect of maximal aerobic exercise on serum muscle enzymes in professional field hockey players. This study aims to determine the effect of increasing maximal aerobic exercise on creatine kinase (CK), creatine kinase-MB (CK-MB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) serum levels. 31 young professional field hockey players (13 female and 18 male players) volunteered for this study. All participants underwent the shuttle run test. Blood samples were taken from each participant before the shuttle run test. Post test blood samples were taken immediately after exercise and one hour after respectively. Pre and post test CK, CK-MB, AST and ALT values were measured by means of auto analyzer using original kits. The acute post test measure of the CK level increased in male (p=0.002) and female (p=0.00) sportsmen. CK-MB values obtained one hour after the exercise was lower than those before the exercise in males (p=0.02). In females (p=0.017) and males (p=0.05) AST activity significantly increased immediately after exercise and decreased to resting activity 1 h recovery. ALT significantly increased immediately after exercise in female (p=0.03) and male (p=0.00) athletes and after 1 h recovery ALT activities decreased below resting values. The timing and severity of exercise used in our study increased CK values, decreased CK-MB values and AST, ALT values increased in female and male field hockey players.

Sex- and age-related differences in half-marathon performance and competitiveness in the world's largest half-marathon - the GöteborgsVarvet.

PubMed

Knechtle, B; Nikolaidis, P T

2018-01-01

In road runners, the age-related performance decline has been well investigated for marathoners, but little is known for half-marathoners. We analysed data from 138,616 runners (48,148 women and 90,469 men) competing between 2014 and 2016 in GöteborgsVarvet, the world's largest half-marathon. The men-to-women ratio in participants increased with age, the fastest race times were observed in age groups ˂35 and 35-39 years in women and in age group 35-39 years in men, the main effect of sex and the sex × age group interaction on race time were trivial, and the competitiveness was denser in men and in the younger age groups. In summary, in half-marathon running in the largest half-marathon in the world, the GöteborgsVarvet, women achieved the fastest race time at an earlier age compared to men where the fastest race times were observed in women in age groups ˂35 and 35-39 years and in men in age group 35-39 years.

Effect of inhaled nitric oxide on cerebrospinal fluid and blood nitrite concentrations in newborn lambs

PubMed Central

Conahey, George R.; Power, Gordon G.; Hopper, Andrew O.; Terry, Michael H.; Kirby, Laura S.; Blood, Arlin B.

2009-01-01

Inhaled nitric oxide (iNO) has many extrapulmonary effects. As the half-life of NO in blood is orders of magnitude less than the circulation time from lungs to the brain, the mediator of systemic effects of iNO is unknown. We hypothesized that concentrations of nitrite, a circulating byproduct of NO with demonstrated NO bioactivity, would increase in blood and cerebrospinal fluid (CSF) during iNO therapy. iNO (80ppm) was given to six newborn lambs and results compared to six control lambs. Blood and CSF nitrite concentrations increased two-fold in response to iNO. cGMP increased in blood but not CSF suggesting brain guanylate cyclase activity was not increased. When sodium nitrite was infused intravenously blood and CSF nitrite levels increased within 10 min and reached similar levels of 14.6±1.5 µM after 40 min. The reactivity of nitrite in hemoglobin-free brain homogenates was investigated, with the findings that nitrite did not disappear nor did measurable amounts of s-nitroso, n-nitroso, or iron-nitrosyl-species appear. We conclude that although nitrite diffuses freely between blood and CSF, due to its lack of reactivity in the brain, nitrite’s putative role as the mediator of the systemic effects of iNO is limited to intravascular reactions. PMID:18535482

Tailoring treatment of haemophilia B: accounting for the distribution and clearance of standard and extended half-life FIX concentrates.

PubMed

Iorio, Alfonso; Fischer, Kathelijn; Blanchette, Victor; Rangarajan, Savita; Young, Guy; Morfini, Massimo

2017-06-02

The prophylactic administration of factor IX (FIX) is considered the most effective treatment for haemophilia B. The inter-individual variability and complexity of the pharmacokinetics (PK) of FIX, and the rarity of the disease have hampered identification of an optimal treatment regimens. The recent introduction of extended half-life recombinant FIX molecules (EHL-rFIX), has prompted a thorough reassessment of the clinical efficacy, PK and pharmacodynamics of plasma-derived and recombinant FIX. First, using longer sampling times and multi-compartmental PK models has led to more precise (and favourable) PK for FIX than was appreciated in the past. Second, investigating the distribution of FIX in the body beyond the vascular space (which is implied by its complex kinetics) has opened a new research field on the role for extravascular FIX. Third, measuring plasma levels of EHL-rFIX has shown that different aPTT reagents have different accuracy in measuring different FIX molecules. How will this new knowledge reflect on clinical practice? Clinical decision making in haemophilia B requires some caution and expertise. First, comparisons between different FIX molecules must be assessed taking into consideration the comparability of the populations studied and the PK models used. Second, individual PK estimates must rely on multi-compartmental models, and would benefit from adopting a population PK approach. Optimal sampling times need to be adapted to the prolonged half-life of the new EHL FIX products. Finally, costs considerations may apply, which is beyond the scope of this manuscript but might be deeply connected with the PK considerations discussed in this communication.

Positive effect of exercise training at maximal fat oxidation intensity on body composition and lipid metabolism in overweight middle-aged women.

PubMed

Tan, Sijie; Wang, Jianxiong; Cao, Liquan; Guo, Zhen; Wang, Yuan

2016-05-01

The purpose of this study was to test the hypothesis that 10 weeks of supervised exercise training at the maximal fat oxidation (FATmax) intensity would improve important variables of body composition and lipid metabolism in overweight middle-aged women. A longitudinal study design was employed to evaluate the effects of FATmax exercise training. Thirty women (45-59 years old; BMI 28·2 ± 1·8 kg m(-2) ; body fat 38·9 ± 4·1%) were randomly allocated into the Exercise and Control groups, n = 15 in each group. Body composition, FATmax, predicted VO2 max, lipid profile, plasma lipoprotein lipase activity and serum leptin concentration were measured before and after the experimental period. The Exercise group was trained at the individualized FATmax intensity, 5 days per week and 1 h per day for 10 weeks. No diet control was introduced during the experimental period for all participants. Exercise group obtained significant decreases in body mass, BMI, body fat % and abdominal fat mass, as well as the concentrations of triglycerides, serum leptin and blood glucose. The activity of lipoprotein lipase was increased in trained participants. There were no changes in these variables in the Control group. In addition, there was no significant change in daily energy intake for all participants before and after the experimental period. In conclusion, the 10-week FATmax exercise training achieved improvements in body composition and lipid metabolism in overweight middle-aged women. This result suggests FATmax is an effective exercise training intensity for obesity treatment. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Two-stage concentrating systems for pumping of solar lasers

NASA Astrophysics Data System (ADS)

Klichev, Sh.; Bakhramov, S.; Abdurakhmanov, A.; Fazilov, A.; Payziyev, Sh.; Ismanjanov, A.; Bokoev, K.; Dudko, J.; Klichev, Z.

2008-02-01

One of the ways to increase the concentrating ability of solar concentrators used for pumping of lasers is an additional concentration of a sunlight by a secondary concentrator allocated in a focal area of the primary concentrator. Limiting concentrations of those compound systems on the basis of non-imaging optics have been received by Winston. However more detailed calculations on the basis of irradiance integral are necessary for designing and practical realization of such systems. It is especially important for the systems including generally compound of two secondary concentrators. The full design procedure for concentration by systems of type compound parabolic concentrator or Winston concentrator (focon) and a cone concentrator is developed in the work in view of real distribution of brightness on a solar disk and discrepancies of primary concentrator geometry. The generalized dependences of efficiency of compound systems for the maximal and mean concentration in a focal plane of the primary paraboloidal concentrator depending on its disclosing angle U 0 and discrepancies of geometry are received. It is shown, that focon only up to U 0 < 30° is more effective, than the cone and further their efficiencies are identical. It is shown, that secondary concentrator allows to increase the pumping efficiency not less, than 30%.

High Intensity Interval Training for Maximizing Health Outcomes.

PubMed

Karlsen, Trine; Aamot, Inger-Lise; Haykowsky, Mark; Rognmo, Øivind

Regular physical activity and exercise training are important actions to improve cardiorespiratory fitness and maintain health throughout life. There is solid evidence that exercise is an effective preventative strategy against at least 25 medical conditions, including cardiovascular disease, stroke, hypertension, colon and breast cancer, and type 2 diabetes. Traditionally, endurance exercise training (ET) to improve health related outcomes has consisted of low- to moderate ET intensity. However, a growing body of evidence suggests that higher exercise intensities may be superior to moderate intensity for maximizing health outcomes. The primary objective of this review is to discuss how aerobic high-intensity interval training (HIIT) as compared to moderate continuous training may maximize outcomes, and to provide practical advices for successful clinical and home-based HIIT. Copyright © 2017. Published by Elsevier Inc.

Nonimaging concentrators for photovoltaic arrays in space

NASA Technical Reports Server (NTRS)

Winston, R.; Greenman, P.; Rockey, D.

1981-01-01

Two stage concentrators are studied in order to design an optimum concentrator for photovoltaic arrays in space. The study is directed at designs with two-dimensional geometries because they are better suited to moderate concentrations of about 10 X to 50 X, and because the instantaneous flux distribution is more uniform. It is found that with an f/0.5 primary, where f is the focal length of the primary, the flux distribution is very smooth regardless of the angle of incidence of the radiation. As the focal ratio is increased, peaks in the distribution begin to appear. The nonuniformities can be reduced by introducing small, closely spaced distortions into the reflecting surfaces, and practical arrays can achieve a concentration of 10 when the acceptance half angle is 4.25 deg or 50 when the acceptance half angle is + or - 1 deg.

Transmutation of skyrmions to half-solitons driven by the nonlinear optical spin Hall effect.

PubMed

Flayac, H; Solnyshkov, D D; Shelykh, I A; Malpuech, G

2013-01-04

We show that the spin domains, generated in the linear optical spin Hall effect by the analog of spin-orbit interaction for exciton polaritons, are associated with the formation of a Skyrmion lattice. In the nonlinear regime, the spin anisotropy of the polariton-polariton interactions results in a spatial compression of the domains and in a transmutation of the Skyrmions into oblique half-solitons. This phase transition is associated with both the focusing of the spin currents and the emergence of a strongly anisotropic emission pattern.

The Effect of Estradiol on the Growth Plate Chondrocytes of Limb and Spine from Postnatal Mice in vitro: The Role of Estrogen-Receptor and Estradiol Concentration.

PubMed

Shi, Sheng; Zheng, Shuang; Li, Xin-Feng; Liu, Zu-De

2017-01-01

Objectives: Skeletal development is a complex process. Little is known about the different response of limb or spine growth plate chondrocytes (LGP or SGP) to the estrogen level and the role of estrogen receptor (ER) during postnatal stage. Methods: LGP and SGP chondrocytes were isolated from 50 one-week mice and treated with different concentrations of 17β-estradiol. Cell viability was measured by cell counting kit-8 (CCK-8). The expression of collagen II and X were evaluated by real-time PCR and Western blotting. Then, the response of LGP or SGP chondrocyte after with or without estradiol and specific ER antagonists to block the effect of ERs were also measured by Western blotting and immunofluorescence. Results: Estradiol promoted the chondrogensis of the chondrocytes in vitro and achieved the maximal expression of type II collagen at the dose of 10 -7 M. Additionally, the regulatory effect of estradiol on the chondrogenesis can be mainly relied on ERα. The LGP chondrocytes were more sensitive to the estradiol treatment than SGP in the expression of type II collagen. Conclusions: Estrogen at a pharmacological concentration (10 -7 M) could stimulate the maximal production of type II collagen in the growth plate chondrocytes in vitro, which exerts its activity mainly through ERα in the chondrogenesis. Furthermore, the LGP chondrocytes were more sensitive to the estradiol treatment than SGP in the chondrogenesis.

Acute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclear.

PubMed

Milioni, Fabio; Malta, Elvis de Souza; Rocha, Leandro George Spinola do Amaral; Mesquita, Camila Angélica Asahi; de Freitas, Ellen Cristini; Zagatto, Alessandro Moura

2016-05-01

The aim of the present study was to investigate the effects of acute administration of taurine overload on time to exhaustion (TTE) of high-intensity running performance and alternative maximal accumulated oxygen deficit (MAODALT). The study design was a randomized, placebo-controlled, crossover design. Seventeen healthy male volunteers (age: 25 ± 6 years; maximal oxygen uptake: 50.5 ± 7.6 mL·kg(-1)·min(-1)) performed an incremental treadmill-running test until voluntary exhaustion to determine maximal oxygen uptake and exercise intensity at maximal oxygen uptake. Subsequently, participants completed randomly 2 bouts of supramaximal treadmill-running at 110% exercise intensity at maximal oxygen uptake until exhaustion (placebo (6 g dextrose) or taurine (6 g) supplementation), separated by 1 week. MAODALT was determined using a single supramaximal effort by summating the contribution of the phosphagen and glycolytic pathways. When comparing the results of the supramaximal trials (i.e., placebo and taurine conditions) no differences were observed for high-intensity running TTE (237.70 ± 66.00 and 277.30 ± 40.64 s; p = 0.44) and MAODALT (55.77 ± 8.22 and 55.06 ± 7.89 mL·kg(-1); p = 0.61), which seem to indicate trivial and unclear differences using the magnitude-based inferences approach, respectively. In conclusion, acute 6 g taurine supplementation before exercise did not substantially improve high-intensity running performance and showed an unclear effect on MAODALT.

Exploring growth conditions and Eu2+ concentration effects for KSr2I5:Eu scintillator crystals

NASA Astrophysics Data System (ADS)

Stand, L.; Zhuravleva, M.; Camarda, G.; Lindsey, A.; Johnson, J.; Hobbs, C.; Melcher, C. L.

2016-04-01

Our current research is focused on understanding dopant optimization, growth rate, homogeneity and their impact on the overall performance of KSr2I5:Eu2+ single crystal scintillators. In this work we have investigated the effects of Eu2+ concentration in the potassium strontium iodide matrix, and we found that the concentration needed to maximize the light yield was 4 mol%. In order to assess the effects of the pulling rate, we grew single crystals at 12, 24 and 120 mm/day via the vertical Bridgman technique. For the sample sizes measured (5×5×5 mm3), we found that the crystal grown at the fastest rate of 120 mm/day showed a light yield within ~7% of the more slowly grown boules, and no significant change was observed in the energy resolution. Therefore, light yields from 88,000 to 96,000 ph/MeV and energy resolutions from 2.4 to 3.0% (at 662 keV) were measured for KSr2I5:Eu 4% over a relatively wide range of growth conditions. In order to assess the homogeneity of KSr2I5:Eu 4%, a newly developed micro-resolution X-ray technique was used to map the light yield as a function of excitation position. In the crystals that we studied, we did not observe any significant inhomogeneity other than a smooth gradient due to light collection and self absorption effects.

Increased plasma O2 solubility improves O2 uptake of in situ dog muscle working maximally.

PubMed

Hogan, M C; Willford, D C; Keipert, P E; Faithfull, N S; Wagner, P D

1992-12-01

A perfluorocarbon emulsion [formulation containing 90% wt/vol perflubron (perfluorooctylbromide); Alliance Pharmaceutical] was used to increase O2 solubility in the plasma compartment during hyperoxic low hemoglobin concentration ([Hb]) perfusion of a maximally working dog muscle in situ. Our hypothesis was that the increased plasma O2 solubility would increase the muscle O2 diffusing capacity (DO2) by augmenting the capillary surface area in contact with high [O2]. Oxygen uptake (VO2) was measured in isolated in situ canine gastrocnemius (n = 4) while working for 6 min at a maximal stimulation rate of 1 Hz (isometric tetanic contractions) on three to four separate occasions for each muscle. On each occasion, the last 4 min of the 6-min work period was split into 2 min of a control treatment (only emulsifying agent mixed into blood) and 2 min of perflubron treatment (6 g/kg body wt), reversing the order for each subsequent work bout. Before contractions, the [Hb] of the dog was decreased to 8-9 g/100 ml and arterial PO2 was increased to 500-600 Torr by having the dog breathe 100% O2 to maximize the effect of the perflubron. Muscle blood flow was held constant between the two experimental conditions. Plasma O2 solubility was almost doubled to 0.005 ml O2 x 100 ml blood-1 x Torr-1 by the addition of the perflubron. Muscle O2 delivery and maximal VO2 were significantly improved (at the same blood flow and [Hb]) by 11 and 12.6%, respectively (P < 0.05), during the perflubron treatment compared with the control. O2 extraction by the muscle remained the same between the two treatments, as did the estimate of DO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition effect of engineered silver nanoparticles to bloom forming cyanobacteria

NASA Astrophysics Data System (ADS)

Thuy Duong, Thi; Son Le, Thanh; Thu Huong Tran, Thi; Kien Nguyen, Trung; Ho, Cuong Tu; Hien Dao, Trong; Phuong Quynh Le, Thi; Chau Nguyen, Hoai; Dang, Dinh Kim; Thu Huong Le, Thi; Thu Ha, Phuong

2016-09-01

Silver nanoparticle (AgNP) has a wide range antibacterial effect and is extensively used in different aspects of medicine, food storage, household products, disinfectants, biomonitoring and environmental remediation etc. In the present study, we examined the growth inhibition effect of engineered silver nanoparticles against bloom forming cyanobacterial M. aeruginosa strain. AgNPs were synthesized by a chemical reduction method at room temperature and UV-Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM) showed that they presented a maximum absorption at 410 nm and size range between 10 and 18 nm. M. aeruginosa cells exposed during 10 d to AgNPs to a range of concentrations from 0 to 1 mg l-1. The changes in cell density and morphology were used to measure the responses of the M. aeruginosa to AgNPs. The control and treatment units had a significant difference in terms of cell density and growth inhibition (p < 0.05). Increasing the concentration of AgNPs, a reduction of the cell growths in all treatment was observed. The inhibition efficiency was reached 98.7% at higher concentration of AgNPs nanoparticles. The term half maximal effective concentration (EC50) based on the cell growth measured by absorbance at 680 nm (A680) was 0.0075 mg l-1. The inhibition efficiency was 98.7% at high concentration of AgNPs (1 mg l-1). Image of SEM and TEM reflected a shrunk and damaged cell wall indicating toxicity of silver nanoparticles toward M. aeruginosa.

Expectation maximization for hard X-ray count modulation profiles

NASA Astrophysics Data System (ADS)

Benvenuto, F.; Schwartz, R.; Piana, M.; Massone, A. M.

2013-07-01

Context. This paper is concerned with the image reconstruction problem when the measured data are solar hard X-ray modulation profiles obtained from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) instrument. Aims: Our goal is to demonstrate that a statistical iterative method classically applied to the image deconvolution problem is very effective when utilized to analyze count modulation profiles in solar hard X-ray imaging based on rotating modulation collimators. Methods: The algorithm described in this paper solves the maximum likelihood problem iteratively and encodes a positivity constraint into the iterative optimization scheme. The result is therefore a classical expectation maximization method this time applied not to an image deconvolution problem but to image reconstruction from count modulation profiles. The technical reason that makes our implementation particularly effective in this application is the use of a very reliable stopping rule which is able to regularize the solution providing, at the same time, a very satisfactory Cash-statistic (C-statistic). Results: The method is applied to both reproduce synthetic flaring configurations and reconstruct images from experimental data corresponding to three real events. In this second case, the performance of expectation maximization, when compared to Pixon image reconstruction, shows a comparable accuracy and a notably reduced computational burden; when compared to CLEAN, shows a better fidelity with respect to the measurements with a comparable computational effectiveness. Conclusions: If optimally stopped, expectation maximization represents a very reliable method for image reconstruction in the RHESSI context when count modulation profiles are used as input data.

Improving Large Cetacean Implantable Satellite Tag Designs to Maximize Tag Robustness and Minimize Health Effects to Individual Animals

DTIC Science & Technology

2015-09-30

Olympia, WA, 98501 & National Marine Mammal Laboratory Alaska Fisheries Science Center, NOAA Fisheries 7600 Sand Point Way NE Seattle, WA...to Maximize Tag Robustness and Minimize Health Effects to Individual Animals Alexandre N. Zerbini Cascadia Research Collective 218 ½ 4 th Ave W...available to the marine mammal community after the conclusion of the project. This study has been carried out by scientists and engineers from eight

An Efficient and Effective Design of InP Nanowires for Maximal Solar Energy Harvesting.

PubMed

Wu, Dan; Tang, Xiaohong; Wang, Kai; He, Zhubing; Li, Xianqiang

2017-11-25

Solar cells based on subwavelength-dimensions semiconductor nanowire (NW) arrays promise a comparable or better performance than their planar counterparts by taking the advantages of strong light coupling and light trapping. In this paper, we present an accurate and time-saving analytical design for optimal geometrical parameters of vertically aligned InP NWs for maximal solar energy absorption. Short-circuit current densities are calculated for each NW array with different geometrical dimensions under solar illumination. Optimal geometrical dimensions are quantitatively presented for single, double, and multiple diameters of the NW arrays arranged both squarely and hexagonal achieving the maximal short-circuit current density of 33.13 mA/cm 2 . At the same time, intensive finite-difference time-domain numerical simulations are performed to investigate the same NW arrays for the highest light absorption. Compared with time-consuming simulations and experimental results, the predicted maximal short-circuit current densities have tolerances of below 2.2% for all cases. These results unambiguously demonstrate that this analytical method provides a fast and accurate route to guide high performance InP NW-based solar cell design.

Half-time strategies to enhance second-half performance in team-sports players: a review and recommendations.

PubMed

Russell, Mark; West, Daniel J; Harper, Liam D; Cook, Christian J; Kilduff, Liam P

2015-03-01

A number of intermittent team sports require that two consecutive periods of play (lasting for ~30-45 min) are separated by a 10-20 min half-time break. The half-time practices employed by team-sports players generally include returning to the changing rooms, temporarily relaxing from the cognitive and physical demands of the first half, rehydration and re-fuelling strategies, addressing injury or equipment concerns, and receiving tactical instruction and coach feedback. However, the typically passive nature of these actions has been associated with physiological changes that impair performance during the second half. Both physical and cognitive performances have been found to decline in the initial stages of subsequent exercise that follows half-time. An increased risk of injury has also been observed during this period. Therefore, half-time provides sports scientists and strength and conditioning coaches with an opportunity to optimise second-half performance. An overview of strategies thought to benefit team-sports athletes is presented; specifically, the efficacy of heat maintenance strategies (including passive and active methods), post-activation potentiation, hormonal priming, and modified hydro-nutritional practices are discussed. A theoretical model of applying these strategies in a manner that compliments current practice is also offered.

Calculations on the half-lives of Cluster decay in two-potential approach

NASA Astrophysics Data System (ADS)

Soylu, A.

The half-lives of the cluster decay (CD) from the isotopes having the known experimental values, the half-lives of the α-decay (AD) of same nuclei and also the branching ratios are obtained, within the framework of two-potential approach with cosh potential including with and without the isospin effects. Using two-potential approach and taking into account the isospin effects in the calculations decrease the rms values and they improve the results. The obtained branching ratios are in good agreement with the experimental ones for some isotopes. It is obtained that the isospin-dependent potentials have an influence on the half-lives of the cluster decays of nuclei. Present calculations would be important for predicting the experimental half-lives and branching ratios for the cluster decays of different types of isotopes.

Synchronous Half-Wave Rectifier

NASA Technical Reports Server (NTRS)

Rippel, Wally E.

1989-01-01

Synchronous rectifying circuit behaves like diode having unusually low voltage drop during forward-voltage half cycles. Circuit particularly useful in power supplies with potentials of 5 Vdc or less, where normal forward-voltage drops in ordinary diodes unacceptably large. Fabricated as monolithic assembly or as hybrid. Synchronous half-wave rectifier includes active circuits to attain low forward voltage drop and high rectification efficiency.

Metaplastic Effects of Subanesthetic Ketamine on CA1 Hippocampal Function

PubMed Central

Izumi, Yukitoshi; Zorumski, Charles F.

2014-01-01

Ketamine is a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist of interest in neuropsychiatry. In the present studies, we examined the effects of subanesthetic, low micromolar ketamine on excitatory postsynaptic potentials (EPSPs), population spikes (PSs) and synaptic plasticity in the CA1 region of rat hippocampal slices. Ketamine acutely inhibited NMDAR-mediated synaptic responses with half-maximal effects near 10 µM. When administered for 15–30 min at 1–10 µM, ketamine had no effect on baseline dendritic AMPA receptor-mediated EPSPs, but persistently enhanced somatic EPSPs in the pyramidal cell body layer and augmented PS firing. Acute low micromolar ketamine also had no effect on the induction of long-term potentiation (LTP) but blocked long-term depression (LTD). Following 30 min administration of 1–10 µM ketamine, however, a slowly developing and persistent form of LTP inhibition was observed that took two hours following ketamine washout to become manifest. This LTP inhibition did not result from prolonged or enhanced NMDAR inhibition during drug washout. Effects of low ketamine on somatic EPSPs and LTP were not mimicked by a high ketamine concentration that completely inhibited NMDARs, and both of these effects were blocked by co-administration of low ketamine with a low concentration of the competitive NMDAR antagonist, 2-amino-5-phosphonovalerate or inhibitors of nitric oxide synthase. These results indicate that concentrations of ketamine relevant to psychotropic and psychotomimetic effects have complex metaplastic effects on hippocampal function that involve activation of unblocked NMDARs during ketamine exposure. PMID:25128848

Maximally slicing a black hole.

NASA Technical Reports Server (NTRS)

Estabrook, F.; Wahlquist, H.; Christensen, S.; Dewitt, B.; Smarr, L.; Tsiang, E.

1973-01-01

Analytic and computer-derived solutions are presented of the problem of slicing the Schwarzschild geometry into asymptotically flat, asymptotically static, maximal spacelike hypersurfaces. The sequence of hypersurfaces advances forward in time in both halves (u greater than or equal to 0, u less than or equal to 0) of the Kruskal diagram, tending asymptotically to the hypersurface r = 3/2 M and avoiding the singularity at r = 0. Maximality is therefore a potentially useful condition to impose in obtaining computer solutions of Einstein's equations.

The effect of ethylene on root growth of Zea mays seedlings

NASA Technical Reports Server (NTRS)

Whalen, M. C.; Feldman, L. J.

1988-01-01

The control of primary root growth in Zea mays cv. Merit by ethylene was examined. At applied concentrations of ethylene equal to or greater than 0.1 microliter L-1, root elongation during 24 h was inhibited. The half-maximal response occurred at 0.6 microliter L-1 and the response saturated at 6 microliters L-1. Inhibition of elongation took place within 20 min. However, after ethylene was removed, elongation recovered to control values within 15 min. Root elongation was also inhibited by green light. The inhibition caused by a 24-h exposure to ethylene was restricted to the elongating region just behind the apex, with inhibition of cortical cell elongation being the primary contributor to the effect. Based on use of 2,5-norbornadiene, a gaseous competitive inhibitor of ethylene, it was concluded that endogenous ethylene normally inhibits root elongation.

Effects of elevated atmospherical CO2 concentration and nitrogen fertilisation on priming effects in soils

NASA Astrophysics Data System (ADS)

Ohm, H.; Marschner, B.

2009-04-01

It is expected that the biomass production and thus the input of organic carbon to the soil will increase in response to elevated CO¬2 concentrations in the atmosphere. It remains unclear whether this will lead to a long term increased carbon pool, because only little is known about the stability of the additional carbon inputs. The soil samples were taken on an agricultural field at the experimental farm of the Federal Agricultural Research Centre (FAL) in Braunschweig, Germany. A Free-Air Carbon-dioxide Enrichment (FACE) system was installed here in May 2000. It consists of rings with 20 m diameter. Two rings were operated with CO2 enriched air (550 ppm), another two rings received ambient air (370 ppm). One half of each ring received the full amount of nitrogen fertiliser, the remainder received only half of this N-amount. The soil samples were taken after 6 years of operation and were incubated with 14C-labeled fructose and alanine for 21 days. Furthermore, combined additions with the respective substrate and ammonium nitrate or ammonium nitrate alone were conducted. The microbial biomass was determined after 2 and 21 days. In the untreated controls the SOC mineralisation amounted to 0.59 to 0.68%. The addition of fructose, fructose+NH4NO3, alanine and alanine+NH4NO3 to the different soil samples increased SOC mineralization and thus caused priming effects of different extents. For NH4NO3 no priming effects occurred. The addition of fructose induced positive priming effects in all samples. The lowest priming effect was observed in the sample ambient CO2+50% N (+50%), either with fructose alone or in combination with NH4NO3. The addition of alanine caused similar priming effects in the ambient CO2+100% N and the elevated CO2+100% N samples (+92.4 and +95.6%, respectively). Again, the lowest priming effect was observed in the sample ambient CO2+50% N. The microbial biomass showed a clear increase in the substrate treated samples compared to the controls. The

Torque, power and muscle activation of eccentric and concentric isokinetic cycling.

PubMed

Green, David J; Thomas, Kevin; Ross, Emma Z; Green, Steven C; Pringle, Jamie S M; Howatson, Glyn

2018-06-01

This study aimed to establish the effect of cycling mode and cadence on torque, external power output, and lower limb muscle activation during maximal, recumbent, isokinetic cycling. After familiarisation, twelve healthy males completed 6 × 10 s of maximal eccentric (ECC) and concentric (CON) cycling at 20, 40, 60, 80, 100, and 120 rpm with five minutes recovery. Vastus lateralis, medial gastrocnemius, rectus femoris, and biceps femoris surface electromyography was recorded throughout. As cadence increased, peak torque linearly decreased during ECC (350-248 N·m) and CON (239-117 N·m) and peak power increased in a parabolic manner. Crank angle at peak torque increased with cadence in CON (+13°) and decreased in ECC (-9.0°). At all cadences, peak torque (mean +129 N·m, range 111-143 N·m), and power (mean +871 W, range 181-1406 W), were greater during ECC compared to CON. For all recorded muscles the crank angle at peak muscle activation was greater during ECC compared to CON. This difference increased with cadence in all muscles except the vastus lateralis. Additionally, peak vastus laterallis and biceps femoris activation was greater during CON compared to ECC. Eccentric cycling offers a greater mechanical stimulus compared to concentric cycling but the effect of cadence is similar between modalities. Markers of technique (muscle activation, crank angle at peak activation and torque) were different between eccentric and concentric cycling and respond differently to changes in cadence. Such data should be considered when comparing between, and selecting cadences for, recumbent, isokinetic, eccentric and concentric cycling. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Effects of strain on the half-metallicity and spin gapless feature of Ti2YSi (Y = Fe, Co) alloys

NASA Astrophysics Data System (ADS)

Fan, Xiaoguang; Li, Jincheng; Jin, Yingjiu

2018-05-01

Half-metals and spin gapless semiconductors (SGSs), which exhibit 100% spin polarization at the Fermi level, are considered important candidates for spintronics. Using first-principles calculations, we have investigated the effects of uniform strain and tetragonal distortion on the half-metallicity and spin gapless feature of inverse Heusler Ti2YSi (Y = Fe and Co) alloys. Results show that for uniform strains, the half-metallicity occurs in the ranges of lattice parameters from 5.938 Å to 6.535 Å for Ti2FeSi and from 5.924 Å to 6.840 Å for Ti2CoSi. Tetragonal distortions over the ranges of ‑2.0% to +2.5% and ‑2.6% to +4.1% could destroy the half-metallicity for Ti2FeSi and Ti2CoSi, respectively. On the other hand, Ti2CoSi is an SGS at lattice constants of 5.968-6.023 Å. An interesting finding is that Ti2CoSi reproduces the SGS character with increasing the lattice parameters to 6.784-6.840 Å. Small tetragonal distortions with ±0.2% will destroy the SGS character of Ti2CoSi.

Endurance training and maximal oxygen consumption with ageing: Role of maximal cardiac output and oxygen extraction.

PubMed

Montero, David; Díaz-Cañestro, Candela

2016-05-01

The increase in maximal oxygen consumption (VO2max) with endurance training is associated with that of maximal cardiac output (Qmax), but not oxygen extraction, in young individuals. Whether such a relationship is altered with ageing remains unclear. Therefore, we sought systematically to review and determine the effect of endurance training on and the associations among VO2max, Qmax and arteriovenous oxygen difference at maximal exercise (Ca-vO2max) in healthy aged individuals. We conducted a systematic search of MEDLINE, Scopus and Web of Science, from their inceptions until May 2015 for articles assessing the effect of endurance training lasting 3 weeks or longer on VO2max and Qmax and/or Ca-vO2max in healthy middle-aged and/or older individuals (mean age ≥40 years). Meta-analyses were performed to determine the standardised mean difference (SMD) in VO2max, Qmax and Ca-vO2max between post and pre-training measurements. Subgroup and meta-regression analyses were used to evaluate the associations among SMDs and potential moderating factors. Sixteen studies were included after systematic review, comprising a total of 153 primarily untrained healthy middle-aged and older subjects (mean age 42-71 years). Endurance training programmes ranged from 8 to 52 weeks of duration. After data pooling, VO2max (SMD 0.89; P < 0.0001) and Qmax (SMD 0.61; P < 0.0001) were increased after endurance training; no heterogeneity among studies was detected. Ca-vO2max was only increased with endurance training interventions lasting more than 12 weeks (SMD 0.62; P = 0.001). In meta-regression, the SMD in Qmax was positively associated with the SMD in VO2max (B = 0.79, P = 0.04). The SMD in Ca-vO2max was not associated with the SMD in VO2max (B = 0.09, P = 0.84). The improvement in VO2max following endurance training is a linear function of Qmax, but not Ca-vO2max, through healthy ageing. © The European Society of Cardiology 2015.

Refined boundary conditions on the free surface of an elastic half-space taking into account non-local effects.

PubMed

Chebakov, R; Kaplunov, J; Rogerson, G A

2016-02-01

The dynamic response of a homogeneous half-space, with a traction-free surface, is considered within the framework of non-local elasticity. The focus is on the dominant effect of the boundary layer on overall behaviour. A typical wavelength is assumed to considerably exceed the associated internal lengthscale. The leading-order long-wave approximation is shown to coincide formally with the 'local' problem for a half-space with a vertical inhomogeneity localized near the surface. Subsequent asymptotic analysis of the inhomogeneity results in an explicit correction to the classical boundary conditions on the surface. The order of the correction is greater than the order of the better-known correction to the governing differential equations. The refined boundary conditions enable us to evaluate the interior solution outside a narrow boundary layer localized near the surface. As an illustration, the effect of non-local elastic phenomena on the Rayleigh wave speed is investigated.

Effects of funnel web spider toxin on Ca2+ currents in neurohypophysial terminals.

PubMed

Wang, G; Lemos, J R

1994-11-14

Funnel web spider toxin (FTX) is reportedly a specific blocker of P-type Ca2+ channels. The effects of FTX on the Ca2+ currents of isolated neurohypophysial nerve terminals of the rat were investigated using the 'whole-cell' patch-clamp technique. Both the transient and long-lasting Ca2+ current components were maximally elicited by depolarization from a holding potential equal to the normal terminal resting potential (-90 mV). Externally applied FTX inhibited the high-voltage-threshold, transient component of the Ca2+ current in a concentration-dependent manner, with a half-maximal inhibition at a dilution of approximately 1:10000. FTX also shifted the peak current of the I-V relationship by +10 mV. The long-lasting Ca2+ current component, which is sensitive to L-type Ca2+ channel blockers, was insensitive to FTX. The transient current, which is sensitive to omega-conotoxin GVIA, was completely blocked by FTX. These results suggest that there could be a novel, inactivating Ca2+ channel in the rat neurohypophysial terminals which is affected by both N-type and P-type Ca2+ channel blockers.

A Lactate Kinetics Method for Assessing the Maximal Lactate Steady State Workload

PubMed Central

Hering, Gernot O.; Hennig, Ewald M.; Riehle, Hartmut J.; Stepan, Jens

2018-01-01

During a continuously increasing exercise workload (WL) a point will be reached at which arterial lactate accumulates rapidly. This so-called lactate threshold (LT) is associated with the maximal lactate steady state workload (MLSSW), the highest WL, at which arterial lactate concentration [LA] does not change. However, the physiological range in which the LT and the MLSSW occur has not been demonstrated directly. We used minor WL variations in the MLSSW range to assess arterial lactate kinetics in 278 treadmill and 148 bicycle ergometer exercise tests. At a certain workload, minimal further increment of running speed (0.1–0.15 m/s) or cycling power (7–10 W) caused a steep elevation of [LA] (0.9 ± 0.43 mM, maximum increase 2.4 mM), indicating LT achievement. This sharp [LA] increase was more pronounced when higher WL increments were used (0.1 vs. 0.30 m/s, P = 0.02; 0.15 vs. 0.30 m/s, P < 0.001; 7 vs. 15 W, P = 0.002; 10 vs. 15 W, P = 0.001). A subsequent workload reduction (0.1 m/s/7 W) stopped the [LA] increase indicating MLSSW realization. LT based determination of running speed (MLSSW) was highly reproducible on a day-to-day basis (r = 0.996, P < 0.001), valid in a 10 km constant velocity setting (r = 0.981, P < 0.001) and a half marathon race (r = 0.969, P < 0.001). These results demonstrate a fine-tuned regulation of exercise-related lactate metabolism, which can be reliably captured by assessing lactate kinetics at the MLSSW. PMID:29651253

Regulating NH4+, N0-, and K+ concentration and proportions improves in vitro tissue growth.

USDA-ARS?s Scientific Manuscript database

A mixture-amount experiment that simultaneously varied both the ratios and total ionic concentration (from 20-100 mM) of NH4+, NO3+, and K+ was used to maximize sweet orange callus growth cv. ‘Hamlin.’ These experiments were free of ion confounding effects, i.e. ions added via pH adjustments and sa...

Short communication: Effect of conjugated linoleic acid on concentrations of fat-soluble vitamins in milk of lactating ewes.

PubMed

Zeitz, J O; Most, E; Eder, K

2015-10-01

Conjugated linoleic acids (CLA) are well known as milk fat-reducing feed supplements in diets for lactating ruminants. However, their effects on milk concentrations of fat-soluble vitamins are unknown. This study was performed to investigate the hypothesis that CLA affect the concentrations of retinol and tocopherol in ewe milk. For that purpose, group-housed Merino ewes (101 ± 13.7 kg) nursing twin lambs and fed with a hay:concentrate diet were supplemented with either 45 g of a rumen-protected CLA supplement containing 3.4 g of cis-9,trans-11-CLA and 3.4 g of trans-10,cis-12-CLA (CLA group, n=11) or with 45 g of a hydrogenated vegetable fat (control group, n=12) per ewe per day during the first 6 wk of lactation. Feed intake was recorded daily (concentrate) or weekly (hay) per group. Milk spot samples were collected at the beginning of the experiment (5 ± 2.4 d postpartum) and then weekly after lambs had been separated for 2 h from their mothers. The milk fat content was determined and feed and milk were analyzed for concentrations of α-, γ-, and δ-tocopherol and for retinol by HPLC. Dietary intake of tocopherol and retinol was similar in both groups. Feeding CLA decreased milk fat concentration by 23% on average, and during the first 3 wk of the study milk tocopherol concentration tended to be increased by feeding CLA (+17%), but retinol concentrations were not influenced. When related to milk fat, CLA feeding significantly increased both milk tocopherol (+40%) and retinol (+32%) and these effects were evident during the whole experimental period corresponding to the first half of lactation. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Extrinsic doping of the half-Heusler compounds

NASA Astrophysics Data System (ADS)

Stern, Robin; Dongre, Bonny; Madsen, Georg K. H.

2016-08-01

Controlling the p- and n-type doping is a key tool to improve the power-factor of thermoelectric materials. In the present work we provide a detailed understanding of the defect thermochemistry in half-Heusler compounds. We calculate the formation energies of intrinsic and extrinsic defects in state of the art n-type TiNiSn and p-type TiCoSb thermoelectric materials. It is shown how the incorporation of online repositories can reduce the workload in these calculations. In TiNiSn we find that Ni- and Ti-interstitial defects play a crucial role in the carrier concentration of TiNiSn. Furthermore, we find that extrinsic doping with Sb can substantially enhance the carrier concentration, in agreement with experiment. In case of TiCoSb, we find ScTi, FeCo and SnSb being possible p-type dopants. While experimental work has mainly focussed on Sn-doping of the Sb site, the present result underlines the possibility to p-dope TiCoSb on all lattice sites.

Importance of upper-limb inertia in calculating concentric bench press force.

PubMed

Rambaud, Olivier; Rahmani, Abderrahmane; Moyen, Bernard; Bourdin, Muriel

2008-03-01

The purpose of this study was to investigate the influence of upper-limb inertia on the force-velocity relationship and maximal power during concentric bench press exercise. Reference peak force values (Fpeakp) measured with a force plate positioned below the bench were compared to those measured simultaneously with a kinematic device fixed on the barbell by taking (Fpeakt) or not taking (Fpeakb) upper-limb inertia into account. Thirteen men (27.8 +/- 4.1 years, 184.6 +/- 5.5 cm, 99.5 +/- 18.6 kg) performed all-out concentric bench press exercise against 8 loads ranging between 7 and 74 kg. The results showed that for each load, Fpeakb was significantly less than Fpeakp (P < 0.0001), whereas no significant difference was found between Fpeakp and Fpeakt. The values of maximal force (F0), maximal velocity (V0), optimal velocity (Vopt), and maximal power (Pmax), extrapolated from the force- and power-velocity relationships determined with the kinematic device, were significantly underestimated when upper-limb inertia was ignored. The results underline the importance of taking account of the total inertia of the moving system to ensure precise evaluation of upper-limb muscular characteristics in all-out concentric bench press exercise with a kinematic device. A major application of this study would be to develop precise upper-limb muscular characteristic evaluation in laboratory and field conditions by using a simple and cheap kinematic device.

The effects of breathing a helium-oxygen gas mixture on maximal pulmonary ventilation and maximal oxygen consumption during exercise in acute moderate hypobaric hypoxia.

PubMed

Ogawa, Takeshi; Calbet, Jose A L; Honda, Yasushi; Fujii, Naoto; Nishiyasu, Takeshi

2010-11-01

To test the hypothesis that maximal exercise pulmonary ventilation (VE max) is a limiting factor affecting maximal oxygen uptake (VO2 max) in moderate hypobaric hypoxia (H), we examined the effect of breathing a helium-oxygen gas mixture (He-O(2); 20.9% O(2)), which would reduce air density and would be expected to increase VE max. Fourteen healthy young male subjects performed incremental treadmill running tests to exhaustion in normobaric normoxia (N; sea level) and in H (atmospheric pressure equivalent to 2,500 m above sea level). These exercise tests were carried out under three conditions [H with He-O(2), H with normal air and N] in random order. VO2 max and arterial oxy-hemoglobin saturation (SaO(2)) were, respectively, 15.2, 7.5 and 4.0% higher (all p < 0.05) with He-O(2) than with normal air (VE max, 171.9 ± 16.1 vs. 150.1 ± 16.9 L/min; VO2 max, 52.50 ± 9.13 vs. 48.72 ± 5.35 mL/kg/min; arterial oxyhemoglobin saturation (SaO(2)), 79 ± 3 vs. 76 ± 3%). There was a linear relationship between the increment in VE max and the increment in VO2 max in H (r = 0.77; p < 0.05). When subjects were divided into two groups based on their VO2 max, both groups showed increased VE max and SaO(2) in H with He-O(2), but VO2 max was increased only in the high VO2 max group. These findings suggest that in acute moderate hypobaric hypoxia, air-flow resistance can be a limiting factor affecting VE max; consequently, VO2 max is limited in part by VE max especially in subjects with high VO2 max.

Effects of Plyometric Versus Concentric and Eccentric Conditioning Contractions on Upper-Body Postactivation Potentiation.

PubMed

Ulrich, Gert; Parstorfer, Mario

2017-07-01

There are limited data on postactivation potentiation's (PAP) effects after plyometric conditioning contractions (CCs), especially in the upper body. This study compared plyometric CCs with concentric-eccentric and eccentric CCs aiming to improve upper-body power performance due to a PAP effect. Sixteen resistance-trained males completed 3 experimental trials in a randomized order that comprised either a plyometric (PLY), a concentric-eccentric (CON), or an eccentric-only (ECC) CC. Maximal muscle performance, as determined by a ballistic bench-press throw, was measured before (baseline) and 1, 4, 8, 12, and 16 min after each CC. Compared with baseline, bench-press power was significantly enhanced only in CON (P = .046, ES = 0.21) after 8 min of recovery. However, the results obtained from the comparisons between baseline power performance and the individual best power performance for each subject after each CC stimulus showed significant increases in PLY (P < .001, ES = 0.31) and CON (P < .001, ES = 0.38). There was no significant improvement in ECC (P = .106, ES = 0.11). The results indicate that only CON CCs generated increases in bench-press power after 8 min of rest. However, considering an individual rest interval, PLY CCs led to an enhanced power performance in the bench-press exercise, and this increase was comparable to that induced by CON CCs. Due to the easy practical application before a competition, PLY CCs might be an interesting part of warm-up strategies aiming to improve upper-body power performance by reason of PAP.

The intrinsic disorder related alloy scattering in ZrNiSn half-Heusler thermoelectric materials

PubMed Central

Xie, Hanhui; Wang, Heng; Fu, Chenguang; Liu, Yintu; Snyder, G. Jeffrey; Zhao, Xinbing; Zhu, Tiejun

2014-01-01

The intrinsic structural disorder dramatically affects the thermal and electronic transport in semiconductors. Although normally considered an ordered compound, the half-Heusler ZrNiSn displays many transport characteristics of a disordered alloy. Similar to the (Zr,Hf)NiSn based solid solutions, the unsubstituted ZrNiSn compound also exhibits charge transport dominated by alloy scattering, as demonstrated in this work. The unexpected charge transport, even in ZrNiSn which is normally considered fully ordered, can be explained by the Ni partially filling interstitial sites in this half-Heusler system. The influence of the disordering and defects in crystal structure on the electron transport process has also been quantitatively analyzed in ZrNiSn1-xSbx with carrier concentration nH ranging from 5.0×1019 to 2.3×1021 cm−3 by changing Sb dopant content. The optimized carrier concentration nH ≈ 3–4×1020 cm−2 results in ZT ≈ 0.8 at 875K. This work suggests that MNiSn (M = Hf, Zr, Ti) and perhaps most other half-Heusler thermoelectric materials should be considered highly disordered especially when trying to understand the electronic and phonon structure and transport features. PMID:25363573

Inhibition effects of perfluoroalkyl acids on progesterone production in mLTC-1.

PubMed

Zhao, Wei; Cui, Ruina; Wang, Jianshe; Dai, Jiayin

2017-06-01

Perfluoroalkyl substances (PFASs) are a class of fluorine substituted carboxylic acid, sulfonic acid and alcohol, structurally similar to their corresponding parent compounds. Previous study demonstrated the potential endocrine disruption and reproductive toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid, two dominant PFASs in animals and humans. We explored the relationship between eleven perfluoroalkyl acids (PFAAs) with different carbon chain length and their ability to inhibit progesterone production in mouse Leydig tumor cells (mLTC-1). We found an obvious dose-response relationship between progesterone inhibition rate and PFAA exposure concentration in mLTC-1. The relative inhibition rate of progesterone by PFAAs was linearly related to the carbon chain length and molar refractivity of PFAAs. Mitochondrial membrane potential (MMP) decreased after PFAA exposure at the half-maximal inhibitory effect concentration (IC 50 ) of progesterone production in mLTC-1, while the reactive oxygen species (ROS) content increased significantly. These results imply that the inhibition effect of PFAAs on progesterone production might be due, in part, to ROS damage and the decrease in MMP in mLTC-1. Copyright © 2016. Published by Elsevier B.V.

Maximally Expressive Modeling

NASA Technical Reports Server (NTRS)

Jaap, John; Davis, Elizabeth; Richardson, Lea

2004-01-01

Planning and scheduling systems organize tasks into a timeline or schedule. Tasks are logically grouped into containers called models. Models are a collection of related tasks, along with their dependencies and requirements, that when met will produce the desired result. One challenging domain for a planning and scheduling system is the operation of on-board experiments for the International Space Station. In these experiments, the equipment used is among the most complex hardware ever developed; the information sought is at the cutting edge of scientific endeavor; and the procedures are intricate and exacting. Scheduling is made more difficult by a scarcity of station resources. The models to be fed into the scheduler must describe both the complexity of the experiments and procedures (to ensure a valid schedule) and the flexibilities of the procedures and the equipment (to effectively utilize available resources). Clearly, scheduling International Space Station experiment operations calls for a maximally expressive modeling schema.

Dense-array concentrator photovoltaic system using non-imaging dish concentrator and crossed compound parabolic concentrator

NASA Astrophysics Data System (ADS)

Chong, Kok-Keong; Yew, Tiong-Keat; Wong, Chee-Woon; Tan, Ming-Hui; Tan, Woei-Chong; Lai, An-Chow; Lim, Boon-Han; Lau, Sing-Liong; Rahman, Faidz Abdul

2015-04-01

Solar concentrating device plays an important role by making use of optical technology in the design, which can be either reflector or lens to deliver high flux of sunlight onto the Concentrator Photovoltaic (CPV) module receiver ranging from hundreds to thousand suns. To be more competitive compared with fossil fuel, the current CPV systems using Fresnel lens and Parabolic dish as solar concentrator that are widely deployed in United States, Australia and Europe are facing great challenge to produce uniformly focused sunlight on the solar cells as to reduce the cost of electrical power generation. The concept of non-imaging optics is not new, but it has not fully explored by the researchers over the world especially in solving the problem of high concentration solar energy, which application is only limited to be a secondary focusing device or low concentration device using Compound Parabolic Concentrator. With the current advancement in the computer processing power, we has successfully invented the non-imaging dish concentrator (NIDC) using numerical simulation method to replace the current parabolic dish as primary focusing device with high solar concentration ratio (more than 400 suns) and large collective area (from 25 to 125 m2). In this paper, we disclose our research and development on dense array CPV system based on non-imaging optics. The geometry of the NIDC is determined using a special computational method. In addition, an array of secondary concentrators, namely crossed compound parabolic concentrators, is also proposed to further focus the concentrated sunlight by the NIDC onto active area of solar cells of the concentrator photovoltaic receiver. The invention maximizes the absorption of concentrated sunlight for the electric power generation system.

Sex differences in autonomic function following maximal exercise.

PubMed

Kappus, Rebecca M; Ranadive, Sushant M; Yan, Huimin; Lane-Cordova, Abbi D; Cook, Marc D; Sun, Peng; Harvey, I Shevon; Wilund, Kenneth R; Woods, Jeffrey A; Fernhall, Bo

2015-01-01

Heart rate variability (HRV), blood pressure variability, (BPV) and heart rate recovery (HRR) are measures that provide insight regarding autonomic function. Maximal exercise can affect autonomic function, and it is unknown if there are sex differences in autonomic recovery following exercise. Therefore, the purpose of this study was to determine sex differences in several measures of autonomic function and the response following maximal exercise. Seventy-one (31 males and 40 females) healthy, nonsmoking, sedentary normotensive subjects between the ages of 18 and 35 underwent measurements of HRV and BPV at rest and following a maximal exercise bout. HRR was measured at minute one and two following maximal exercise. Males have significantly greater HRR following maximal exercise at both minute one and two; however, the significance between sexes was eliminated when controlling for VO2 peak. Males had significantly higher resting BPV-low-frequency (LF) values compared to females and did not significantly change following exercise, whereas females had significantly increased BPV-LF values following acute maximal exercise. Although males and females exhibited a significant decrease in both HRV-LF and HRV-high frequency (HF) with exercise, females had significantly higher HRV-HF values following exercise. Males had a significantly higher HRV-LF/HF ratio at rest; however, both males and females significantly increased their HRV-LF/HF ratio following exercise. Pre-menopausal females exhibit a cardioprotective autonomic profile compared to age-matched males due to lower resting sympathetic activity and faster vagal reactivation following maximal exercise. Acute maximal exercise is a sufficient autonomic stressor to demonstrate sex differences in the critical post-exercise recovery period.

Effect of azelastine on sulphur dioxide induced impairment of ciliary motility in airway epithelium.

PubMed Central

Tamaoki, J; Chiyotani, A; Sakai, N; Takeyama, K; Konno, K

1993-01-01

OBJECTIVE--The effect of azelastine on airway mucociliary transport function was studied by measuring ciliary motility of human bronchial epithelium in vitro with a photoelectric method. METHOD--Bronchial epithelial cells were obtained by fibreoptic bronchoscopy, mounted in a Rose chamber, and perfused with Krebs-Henseleit solution. The preparations were placed on a microscope stage equipped with an illuminator, and the variations of light intensity caused by ciliary beating were detected by a photometer. RESULTS--The addition of azelastine to the perfusate increased ciliary beat frequency (CBF) in a dose dependent manner without ciliary discoordination. The mean (SE) maximal increase from the baseline value and the concentration required to produce a half maximal effect were 27.0 (4.2)% and 9.2 x 10(-6) mol/l, respectively. Exposure of the cells to the perfusate containing 3 ppm sulphur dioxide rapidly decreased CBF by 59.2 (5.0)%, and was accompanied by a reduction in intracellular cyclic AMP levels from 38.1 (4.3) to 10.1 (2.4) pmol/mg protein. This effect was prevented by pretreatment of cells with azelastine in a dose dependent manner. CONCLUSIONS--Azelastine not only stimulates ciliary motility of airway epithelium and hence mucociliary transport function, but may also protect against sulphur dioxide induced ciliary dysfunction, probably by inhibiting intracellular cyclic AMP loss. PMID:8322244

From Natural Variation to Optimal Policy? The Lucas Critique Meets Peer Effects. NBER Working Paper No. 16865

ERIC Educational Resources Information Center

Carrell, Scott E.; Sacerdote, Bruce I.; West, James E.

2011-01-01

We take cohorts of entering freshmen at the United States Air Force Academy and assign half to peer groups with the goal of maximizing the academic performance of the lowest ability students. Our assignment algorithm uses peer effects estimates from the observational data. We find a negative and significant treatment effect for the students we…

Urinary excretion half life of trichloroacetic acid as a biomarker of exposure to chlorinated drinking water disinfection by-products

PubMed Central

Bader, E; Hrudey, S; Froese, K

2004-01-01

Methods: A longitudinal pilot exposure/intervention study measured the elimination half life of TCAA in urine. Beverage consumption was limited to a public water supply and bottled water of known TCAA concentration, and ingestion volume was managed. The five participants limited fluid consumption to only the water provided. Consumption journals were kept by each participant and their daily first morning urine (FMU) samples were analysed for TCAA and creatinine. TCAA elimination half life curves were generated from a two week washout period using TCAA-free bottled water. Results: Individual elimination half lives ranged from 2.1 to 6.3 days, for single compartment exponential decay, the model which fit the data. Conclusion: Urinary TCAA is persistent enough to be viable as a biomarker of medium term (days) exposure to drinking water TCAA ingestion within a range of realistic concentrations. PMID:15258281

Dual Competing Photovoltaic Supply Chains: A Social Welfare Maximization Perspective

PubMed Central

Su, Shong-Iee Ivan

2017-01-01

In the past decades, the inappropriate subsidy policies in many nations have caused problems such as serious oversupply, fierce competition and subpar social welfare in the photovoltaic (PV) industry in many nations. There is a clear shortage in the PV industry literature regarding how dual supply chains compete and the key decision issues regarding the competition between dual PV supply chains. It is critical to develop effective subsidy policies for the competing PV supply chains to achieve social welfare maximization. This study has explored the dual PV supply chain competition under the Bertrand competition assumption by three game-theoretical modeling scenarios (or supply chain strategies) considering either the public subsidy or no subsidy from a social welfare maximization perspective. A numerical analysis complemented by two sensitivity analyses provides a better understanding of the pricing and quantity decision dynamics in the dual supply chains under three different supply chain strategies and the corresponding outcomes regarding the total supply chain profits, the social welfare and the required total subsidies. The key findings disclose that if there are public subsidies, the dual PV supply chains have the strongest intention to pursue the decentralized strategy to achieve their maximal returns rather than the centralized strategy that would achieve the maximal social welfare; however, the government would need to pay for the maximal subsidy budget. Thus, the best option for the government would be to encourage the dual PV supply chains to adopt a centralized strategy since this will not only maximize the social welfare but also, at the same time, minimize the public subsidy. With a smart subsidy policy, the PV industry can make the best use of the subsidy budget and grow in a sustainable way to support the highly demanded solar power generation in many countries trying very hard to increase the proportion of their clean energy to combat the global

Dual Competing Photovoltaic Supply Chains: A Social Welfare Maximization Perspective.

PubMed

Chen, Zhisong; Su, Shong-Iee Ivan

2017-11-20

In the past decades, the inappropriate subsidy policies in many nations have caused problems such as serious oversupply, fierce competition and subpar social welfare in the photovoltaic (PV) industry in many nations. There is a clear shortage in the PV industry literature regarding how dual supply chains compete and the key decision issues regarding the competition between dual PV supply chains. It is critical to develop effective subsidy policies for the competing PV supply chains to achieve social welfare maximization. This study has explored the dual PV supply chain competition under the Bertrand competition assumption by three game-theoretical modeling scenarios (or supply chain strategies) considering either the public subsidy or no subsidy from a social welfare maximization perspective. A numerical analysis complemented by two sensitivity analyses provides a better understanding of the pricing and quantity decision dynamics in the dual supply chains under three different supply chain strategies and the corresponding outcomes regarding the total supply chain profits, the social welfare and the required total subsidies. The key findings disclose that if there are public subsidies, the dual PV supply chains have the strongest intention to pursue the decentralized strategy to achieve their maximal returns rather than the centralized strategy that would achieve the maximal social welfare; however, the government would need to pay for the maximal subsidy budget. Thus, the best option for the government would be to encourage the dual PV supply chains to adopt a centralized strategy since this will not only maximize the social welfare but also, at the same time, minimize the public subsidy. With a smart subsidy policy, the PV industry can make the best use of the subsidy budget and grow in a sustainable way to support the highly demanded solar power generation in many countries trying very hard to increase the proportion of their clean energy to combat the global

Strength improvements through occlusal splints? The effects of different lower jaw positions on maximal isometric force production and performance in different jumping types

PubMed Central

Maurer, Christian; Heller, Sebastian; Sure, Jil-Julia; Fuchs, Daniel; Mickel, Christoph; Wanke, Eileen M.; Groneberg, David A.

2018-01-01

Objective The influence of the jaw position on postural control, body posture, walking and running pattern has been reported in the literature. All these movements have in common that a relatively small, but well controlled muscle activation is required. The induced effects on motor output through changed jaw positions have been small. Therefore, it has been questioned if it could still be observed in maximal muscle activation. Method Twenty-three healthy, mid age recreational runners (mean age = 34.0 ± 10.3 years) participated in this study. Three different jump tests (squat jump, counter movement jump, and drop jumps from four different heights) and three maximal strength tests (trunk flexion and extension, leg press of the right and left leg) were conducted. Four different dental occlusion conditions and an additional familiarization condition were tested. Subjects performed the tests on different days for which the four occlusion conditions were randomly changed. Results No familiarization effect was found. Occlusion conditions with a relaxation position and with a myocentric condylar position showed significantly higher values for several tests compared to the neutral condition and the maximal occlusion position. Significance was found in the squat jump, countermovement jump, the drop jump from 32cm and 40cm, trunk extension, leg press force and rate of force development. The effect due to the splint conditions is an improvement between 3% and 12% (min and max). No influence of the jaw position on symmetry or balance between extension and flexion muscle was found. Conclusion An influence of occlusion splints on rate of force development (RFD) and maximal strength tests could be confirmed. A small, but consistent increase in the performance parameters could be measured. The influence of the occlusion condition is most likely small compared to other influences as for example training status, age, gender and circadian rhythm. PMID:29474465

A multiple scales approach to maximal superintegrability

NASA Astrophysics Data System (ADS)

Gubbiotti, G.; Latini, D.

2018-07-01

In this paper we present a simple, algorithmic test to establish if a Hamiltonian system is maximally superintegrable or not. This test is based on a very simple corollary of a theorem due to Nekhoroshev and on a perturbative technique called the multiple scales method. If the outcome is positive, this test can be used to suggest maximal superintegrability, whereas when the outcome is negative it can be used to disprove it. This method can be regarded as a finite dimensional analog of the multiple scales method as a way to produce soliton equations. We use this technique to show that the real counterpart of a mechanical system found by Jules Drach in 1935 is, in general, not maximally superintegrable. We give some hints on how this approach could be applied to classify maximally superintegrable systems by presenting a direct proof of the well-known Bertrand’s theorem.

Determination of optimal glycerol concentration for optical tissue clearing

NASA Astrophysics Data System (ADS)

Youn, Eungjun; Son, Taeyoon; Kim, Han-Sung; Jung, Byungjo

2012-02-01

The laser scattering in tissue is significant in diagnostic and therapeutic purposes of laser. Many studies have been conducted to minimize laser scattering in tissue and therefore, to maximize the clinical efficacy by enhancing photon density. Optical clearing agents (OCAs) have been employed for optical tissue clearing (OTC). This study was aimed to investigate the optimal concentration of an OCA, glycerol, in topical application,, so that it can be utilized for clinical diagnosis and therapy in dermatology. Glycerol was topically applied to avoid possible edema caused by dermal injection. The effect of OTC was quantitatively evaluated as a function of the concentration of glycerol with various methods. Optical methods such as optical coherence tomography (OCT) and an integrating sphere were used to assess the enhancement of light penetration depth and refractive index matching. In addition, a non-optical method, ultrasound scanner, was utilized to evaluate quantitatively collagen dissociation. The results revealed that 70 % glycerol was the optimal concentration of OTC for topical application. This study may provide a guideline regarding to the use of glycerol for optimal diagnostic and therapeutic effects in dermatology.

Persistence of long term isokinetic strength deficits in subjects with lateral ankle sprain as measured with a protocol including maximal preloading.

PubMed

Perron, Marc; Moffet, Hélène; Nadeau, Sylvie; Hébert, Luc J; Belzile, Sylvain

2014-12-01

The assessment of muscle function is a cornerstone in the management of subjects who have sustained a lateral ankle sprain. The ankle range of motion being relatively small, the use of preloading allows to measure maximal strength throughout the whole amplitude and therefore to better characterize ankle muscles weaknesses. This study aimed to assess muscle strength of the injured and uninjured ankles in subjects with a lateral ankle sprain, to document the timeline of strength recovery, and to determine the influence of sprain grade on strength loss. Maximal torque of the periarticular muscles of the ankle in a concentric mode using a protocol with maximal preloading was tested in 32 male soldiers at 8 weeks and 6 months post-injury. The evertor muscles of the injured ankles were weaker than the uninjured ones at 8 weeks and 6 months post-injury (P<0.0001, effect size=0.31-0.42). Muscle weaknesses also persisted in the plantarflexors of the injured ankles at 8 weeks (P=0.0014, effect size=0.52-0.58) while at 6 months, only the subjects with a grade II sprain displayed such weaknesses (P<0.0001, effect size 0.27-0.31). The strength of the invertor and dorsiflexor muscles did not differ between sides. The use of an isokinetic protocol with preloading demonstrates significant but small strength deficits in the evertor and plantarflexor muscles. These impairments may contribute to the high incidence of recurrence of lateral ankle sprain in very active individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibitory Effects of Cytosolic Ca(2+) Concentration by Ginsenoside Ro Are Dependent on Phosphorylation of IP3RI and Dephosphorylation of ERK in Human Platelets.

PubMed

Kwon, Hyuk-Woo; Shin, Jung-Hae; Lee, Dong-Ha; Park, Hwa-Jin

2015-01-01

Intracellular Ca(2+) ([Ca(2+)] i ) is platelet aggregation-inducing molecule and is involved in activation of aggregation associated molecules. This study was carried out to understand the Ca(2+)-antagonistic effect of ginsenoside Ro (G-Ro), an oleanane-type saponin in Panax ginseng. G-Ro, without affecting leakage of lactate dehydrogenase, dose-dependently inhibited thrombin-induced platelet aggregation, and the half maximal inhibitory concentration was approximately 155 μM. G-Ro inhibited strongly thrombin-elevated [Ca(2+)] i , which was strongly increased by A-kinase inhibitor Rp-8-Br-cAMPS compared to G-kinase inhibitor Rp-8-Br-cGMPS. G-Ro increased the level of cAMP and subsequently elevated the phosphorylation of inositol 1, 4, 5-triphosphate receptor I (IP3RI) (Ser(1756)) to inhibit [Ca(2+)] i mobilization in thrombin-induced platelet aggregation. Phosphorylation of IP3RI (Ser(1756)) by G-Ro was decreased by PKA inhibitor Rp-8-Br-cAMPS. In addition, G-Ro inhibited thrombin-induced phosphorylation of ERK 2 (42 kDa), indicating inhibition of Ca(2+) influx across plasma membrane. We demonstrate that G-Ro upregulates cAMP-dependent IP3RI (Ser(1756)) phosphorylation and downregulates phosphorylation of ERK 2 (42 kDa) to decrease thrombin-elevated [Ca(2+)] i , which contributes to inhibition of ATP and serotonin release, and p-selectin expression. These results indicate that G-Ro in Panax ginseng is a beneficial novel Ca(2+)-antagonistic compound and may prevent platelet aggregation-mediated thrombotic disease.

Biochemical, physiological, and performance response of a functional watermelon juice enriched in L-citrulline during a half-marathon race

PubMed Central

Martínez-Sánchez, Ascensión; Ramos-Campo, Domingo J.; Fernández-Lobato, Bárbara; Rubio-Arias, Jacobo A.; Alacid, Fernando; Aguayo, Encarna

2017-01-01

ABSTRACT Background: Watermelon is a rich natural source of l-citrulline. This non-essential amino acid increases exercise performance. Objective: Evaluate the effect of Fashion watermelon juice enriched in l-citrulline (CWJ) (3.45 g per 500 mL) in physical performance and biochemical markers after a half-marathon race. Design: A randomised, double blind, crossover design where 2 h after drinking 500 mL of CWJ or placebo (PLA, beverage without l-citrulline) amateur male runners performed two half-marathon races. Jump height, heart rate and rating of perceived exertion were evaluated before and after the races. Moreover, muscle soreness and plasma markers of muscle damage and metabolism were evaluated for 72 h after the races. Results: Muscle soreness perception was significantly lower from 24 to 72 h after the race with CWJ beverage. Immediately after the races, runners under CWJ condition showed plasma lactate and glucose concentrations significantly lower and higher lactate dehydrogenase and l-arginine concentration than runners under PLA. A maintenance of jump heights after the races under CWJ supplementation was found, decreasing significantly with PLA. Conclusion: A single Fashion watermelon juice enriched in l-citrulline dose diminished muscle soreness perception from 24 to 72 h after the race and maintained lower concentrations of plasma lactate after an exhausting exercise. PMID:28659740

Effects on calculated half-widths and shifts from the line coupling for asymmetric-top molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Q.; Boulet, C.; Tipping, R. H.

2014-06-28

The refinement of the Robert-Bonamy formalism by considering the line coupling for linear molecules developed in our previous studies [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013); 140, 104304 (2014)] have been extended to asymmetric-top molecules. For H{sub 2}O immersed in N{sub 2} bath, the line coupling selection rules applicable for the pure rotational band to determine whether two specified lines are coupled or not are established. Meanwhile, because the coupling strengths are determined by relative importance of off-diagonal matrix elements versus diagonal elements of the operator −iS{sub 1} − S{sub 2}, quantitative toolsmore » are developed with which one is able to remove weakly coupled lines from consideration. By applying these tools, we have found that within reasonable tolerances, most of the H{sub 2}O lines in the pure rotational band are not coupled. This reflects the fact that differences of energy levels of the H{sub 2}O states are pretty large. But, there are several dozen strongly coupled lines and they can be categorized into different groups such that the line couplings occur only within the same groups. In practice, to identify those strongly coupled lines and to confine them into sub-linespaces are crucial steps in considering the line coupling. We have calculated half-widths and shifts for some groups, including the line coupling. Based on these calculations, one can conclude that for most of the H{sub 2}O lines, it is unnecessary to consider the line coupling. However, for several dozens of lines, effects on the calculated half-widths from the line coupling are small, but remain noticeable and reductions of calculated half-widths due to including the line coupling could reach to 5%. Meanwhile, effects on the calculated shifts are very significant and variations of calculated shifts could be as large as 25%.« less

Estimates of the half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin in Vietnam veterans of operation ranch hand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pirkle, J.L.; Wolfe, W.H.; Patterson, D.G.

1989-01-01

A half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD; commonly known as dioxin) in serum has been measured in 36 Air Force Vietnam Veterans of Operation Ranch Hand, which was the operation that aerially sprayed the herbicide Agent Orange in Vietnam. From serum specimens taken in 1982 and 1987, the median half-life of 2,3,7,8-TCDD in these Ranch Hand veterans was found to be 7.1 yr (95% confidence interval about the median of 5.8-9.6 yr). These veterans reported no civilian exposure to dioxin or herbicides. Concentrations of 2,3,7,8-TCDD in the 1982 serum specimens from these veterans ranged from 16.9 to 423 parts per trillion onmore » a lipid weight basis. The half-life estimates were not associated with the concentration of 2,3,7,8-TCDD in the 1982 serum specimens. This half-life of 7.1 yr is much longer than the half-life of 2,3,7,8-TCDD reported in animals but is consistent with recent evidence from other human exposures to 2,3,7,8-TCDD.« less

137Cs activity concentration in mosses in the Calabria region, south of Italy

NASA Astrophysics Data System (ADS)

Caridi, F.; Belvedere, A.; D'Agostino, M.; Marguccio, S.

2017-05-01

Many studies carried out after the Chernobyl nuclear accident in 1986 showed that mosses are suitable bioindicators of the radioactive fall-out, given their long life expectancy. 137Cs activity concentration was measured through HPGe gamma spectrometry in different mosses (Hypnum Cupressiforme, Hypnum Andoi, Homalothecium Sericeum, Philonotis Fontana), collected, in 2008 and 2015, from four sampling sites in the Calabria region, south of Italy. Experimental specific activities allowed us to determine the effective and the biological half-time of 137Cs for the investigated plants. The effective half-time was found in the range from (4.2 ± 1.1) to (7.4 ± 1.8) years; the biological half-time varied from (4.9 ± 1.3) to (9.9 ± 2.4) years. Data reported in this article provide useful information on the environmental risk of the studied area and can be further used for a radiological mapping.

7 CFR 51.1441 - Half-kernel.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Half-kernel. 51.1441 Section 51.1441 Agriculture... Standards for Grades of Shelled Pecans Definitions § 51.1441 Half-kernel. Half-kernel means one of the separated halves of an entire pecan kernel with not more than one-eighth of its original volume missing...

The effect of initial concentration, co-application and repeated applications on pesticide degradation in a biobed mixture.

PubMed

Vischetti, Costantino; Monaci, Elga; Cardinali, Alessandra; Casucci, Cristiano; Perucci, Piero

2008-08-01

A 180 d laboratory experiment was conducted to investigate the degradation rates of chlorpyrifos (10 and 50 mg kg(-1)) and metalaxyl (100 mg kg(-1)) separately and co-applied in a biomix constituted by topsoil, vine-branches and urban-waste-garden compost. The effect of repeated application of metalaxyl was also investigated. Microbial biomass-C (MBC) content and metabolic quotient (qCO(2)) were measured to evaluate changes in microbial biomass size and activity induced by the presence of the two pesticides. Degradation rate decreased with increasing concentration of chlorpyrifos in all treatments. Metalaxyl half-life was significantly reduced in co-application with chlorpyrifos indicating a synergic interaction between the two pesticides in favour of enhanced degradation rate for metalaxyl but not for chlorpyrifos. Furthermore, repeated application resulted in a sharp reduction of metalaxyl half-life from 37 d after first application to 4 d after third application. MBC content was negatively influenced by the addition of pesticides but it started to recover immediately, in both separate and co-applied treatments, reaching the control value when pesticide residues were about 50% of the initial concentration. The qCO(2) reached a steady-state after about 20 d in separately applied and 40 d in co-applied treatments, indicating a tendency to arrive at a new metabolic equilibrium. In conclusion, the biomix tested has been shown to degrade pesticides relatively fast and to have a microbial community that is varied enough to allow selection of those microorganisms able to degrade metalaxyl and chlorpyrifos.

Half-life of the superallowed β+ emitter Ne18

NASA Astrophysics Data System (ADS)

Grinyer, G. F.; Smith, M. B.; Andreoiu, C.; Andreyev, A. N.; Ball, G. C.; Bricault, P.; Chakrawarthy, R. S.; Daoud, J. J.; Finlay, P.; Garrett, P. E.; Hackman, G.; Hyland, B.; Leslie, J. R.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Schumaker, M. A.; Svensson, C. E.; Valiente-Dobón, J. J.; Williams, S. J.; Zganjar, E. F.

2007-08-01

The half-life of Ne18 has been determined by detecting 1042-keV γ rays in the daughter F18 following the superallowed-Fermi β+ decay of samples implanted at the center of the 8πγ-ray spectrometer, a spherical array of 20 HPGe detectors. Radioactive Ne18 beams were produced on-line, mass-separated, and ionized using an electron-cyclotron-resonance ionization source at the ISAC facility at TRIUMF in Vancouver, Canada. This is the first high-precision half-life measurement of a superallowed Fermi β decay to utilize both a large-scale HPGe spectrometer and the isotope separation on-line technique. The half-life of Ne18, 1.6656 ± 0.0019 s, deduced following a 1.4σ correction for detector pulse pile-up, is four times more precise than the previous world average. As part of an investigation into potential systematic effects, the half-life of the heavier isotope Ne23 was determined to be 37.11 ± 0.06 s, a factor of 2 improvement over the previous precision.

[Effect of exhaustive weightlifting exercise on EMG, biochemical markers of muscle damage and performance capacity in young male subjects].

PubMed

Minigalin, A D; Shumakov, A R; Novozhilov, A V; Samsonova, A V; Kos'mina, E A; Kalinskiĭ, M I; Baranova, T I; Kubasov, I V; Morozov, V I

2015-01-01

The aim of this study was to examine the effect of exhaustive weightlifting exercise on electrical and biochemical variables and performance capacity in young male subjects. The onset of exercise (80-50% 1RM) was associated with a decrease in the amount of work performed, which was followed by a steady performance capacity at 40-10% 1RM. There were no significant changes of m. rectus femoris EMG maximal amplitude though it tended to be increased during the first half of exercise. A significant blood lactate concentration increase indicated that an anaerobic metabolism was a predominant mechanism of muscle contraction energy-supply. CK level in blood plasma did not change but plasma myoglobin concentration doubled immediately post-exercise. The data presented here suggest that decrease in performance capacity was likely due to progressive "refusal of work" of the fast motor units and work prolongation of weaker, intermediate and slow motor units. Unchangeable CK activity and relatively small increase in myoglobin concentration in plasma suggest that used weightlifting exercise did not induced substantial damage in myocytes' membranes in our subjects.

Effect of triclosan on reproduction, DNA damage and heat shock protein gene expression of the earthworm Eisenia fetida.

PubMed

Lin, Dasong; Li, Ye; Zhou, Qixing; Xu, Yingming; Wang, Di

2014-12-01

Triclosan (TCS) is released into the terrestrial environment via the application of sewage sludge and reclaimed water to agricultural land. More attention has been paid to its effect on non-target soil organisms. In the present study, chronic toxic effects of TCS on earthworms at a wide range of concentrations were investigated. The reproduction, DNA damage, and expression levels of heat shock protein (Hsp70) gene of earthworms were studied as toxicity endpoints. The results showed that the reproduction of earthworms were significantly reduced (p < 0.05) after exposure to the concentrations ranges from 50 to 300 mg kg(-1), with a half-maximal effective concentration (EC50) of 142.11 mg kg(-1). DNA damage, detected by the comet assay, was observed and there was a clear significant (R(2) = 0.941) relationship between TCS concentrations and DNA damage, with the EC50 value of 8.85 mg kg(-1). The expression levels of Hsp70 gene of earthworms were found to be up-regulated under the experimental conditions. The expression level of hsp70 gene increased, up to about 2.28 folds that in the control at 50 mg kg(-1). The EC50 value based on the Hsp70 biomarker was 1.79 mg kg(-1). Thus, among the three toxicity endpoints, the Hsp70 gene was more sensitive to TCS in soil.

Influence of simulated microgravity on the maximal oxygen consumption of nontrained and trained rats

NASA Technical Reports Server (NTRS)

Woodman, Christopher R.; Monnin, Kimberly A.; Sebastian, Lisa A.; Tipton, Charles M.

1993-01-01

The effects of microgravity and endurance training (TR) on maximal O2 consumption was investigated in trained and nontrained (NT) rats subjected to head-down suspension (HDS) by comparing maximal O2 consumption, treadmill run time (RT), and mechanical efficiency (ME) of treadmill running in HDS rats, both NT and TR, and in respective cage controls. It was found that HDS for 28 days was associated with significant reduction in absolute maximal O2 consumption in both TR and NT rats. Relative maximal O2 consumption, however, was significantly reduced in TR but not NT rats. Reductions in RT and ME occurring in both TR and NT rats after 28 days of HDS were similar. The TR rats exhibited greater diuretic, natriuretic, and kaliuretic responses to HDS than the NT rats.

76 FR 37641 - Safety Zone; Independence Day Fireworks Celebration for the City of Half Moon Bay, Half Moon Bay, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

...-AA00 Safety Zone; Independence Day Fireworks Celebration for the City of Half Moon Bay, Half Moon Bay... temporary safety zone in the navigable waters of Half Moon Bay, off of Pillar Point Harbor beach, Half Moon Bay, CA in support of the Independence Day Fireworks Celebration for the City of Half Moon Bay...

A new measurement of the half-life of (166m)Ho.

PubMed

Nedjadi, Y; Bailat, C; Caffari, Y; Froidevaux, P; Wastiel, C; Kivel, N; Guenther-Leopold, I; Triscone, G; Jaquenod, F; Bochud, F

2012-09-01

The work presented here is a new and precise measurement of the half-life of (166m)Ho by determining the activity concentration, using an ionisation chamber calibrated for this nuclide, and measuring the number of (166m)Ho atoms using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Since the isotope (166)Er interferes with the mass spectrometric measurement, Er has to be eliminated from the (166m)Ho radioactive solution. The elimination was achieved using ion-exchange chromatography with the cation exchange resin Dowex AG 50W-X8 and 2-Hydroxybutanoic acid as the mobile phase. After a first transit through the chromatographic column, the purified (166m)Ho eluate was spiked with natural Er to get a resulting Er isotopic composition close to that of natural Er at better than 99.5%, and then it underwent two further separations to eliminate the Er. The activity concentration of this Er-free radioactive (166m)Ho solution was measured in our reference ionisation chamber calibrated for this nuclide by means of the 4πβ(PC)-γ and 4πβ(PS)-4πγ coincidence techniques and integral counting with a well-type NaI(Tl) detector and Monte Carlo efficiencies. An aliquot of this standardized solution was sent to the Paul Scherrer Institute (PSI) for mass concentration determination using an isotope dilution MC-ICP-MS approach. The mass concentration of (166m)Ho in this solution was determined with 0.25% relative standard uncertainty. This value was corroborated by two other independent measurements. The new half-life of (166m)Ho, 1132.6(39) years (k=1), is compatible with the value determined in 1965, but is 5.6% shorter and about 43 times more precise. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nernst-ping-pong model for evaluating the effects of the substrate concentration and anode potential on the kinetic characteristics of bioanode.

PubMed

Peng, Sikan; Liang, Da-Wei; Diao, Peng; Liu, Yanyan; Lan, Fei; Yang, Yuhan; Lu, Shanfu; Xiang, Yan

2013-05-01

Understanding the electron-transfer mechanism and kinetic characteristics of bioanodes is greatly significant to enhance the electron-generating efficiencies in bioelectrochemical systems (BESs). A Nernst-ping-pong model is proposed here to investigate the kinetics and biochemical processes of bioanodes in a microbial electrolysis cell. This model can accurately describe the effects of the substrate (including substrate inhibition) and the anode potential on the current of bioanodes. Results show that the half-wave potential positively shifts as the substrate concentration increases, indicating that the rate-determining steps of anodic processes change from substrate oxidation to intracellular electron transport reaction. The anode potential has negligible effects on the enzymatic catalysis of anodic microbes in the range of -0.25 V to +0.1 V vs. a saturated calomel electrode. It turns out that to reduce the anodic energy loss caused by overpotential, higher substrate concentrations are preferred, if the substrate do not significantly and adversely affect the output current. Copyright © 2013 Elsevier Ltd. All rights reserved.

Metric half-span model support system

NASA Technical Reports Server (NTRS)

Jackson, C. M., Jr.; Dollyhigh, S. M.; Shaw, D. S. (Inventor)

1982-01-01

A model support system used to support a model in a wind tunnel test section is described. The model comprises a metric, or measured, half-span supported by a nonmetric, or nonmeasured half-span which is connected to a sting support. Moments and forces acting on the metric half-span are measured without interference from the support system during a wind tunnel test.

A maximally particle-hole asymmetric spectrum emanating from a semi-Dirac point

NASA Astrophysics Data System (ADS)

Quan, Yundi; Pickett, Warren E.

2018-02-01

Tight binding models have proven an effective means of revealing Dirac (massless) dispersion, flat bands (infinite mass), and intermediate cases such as the semi-Dirac (sD) dispersion. This approach is extended to a three band model that yields, with chosen parameters in a two-band limit, a closed line with maximally asymmetric particle-hole dispersion: infinite mass holes, zero mass particles. The model retains the sD points for a general set of parameters. Adjacent to this limiting case, hole Fermi surfaces are tiny and needle-like. A pair of large electron Fermi surfaces at low doping merge and collapse at half filling to a flat (zero energy) closed contour with infinite mass along the contour and enclosing no carriers on either side, while the hole Fermi surface has shrunk to a point at zero energy, also containing no carriers. The tight binding model is used to study several characteristics of the dispersion and density of states. The model inspired generalization of sD dispersion to a general  ± \\sqrt{k_x2n +k_y2m} form, for which analysis reveals that both n and m must be odd to provide a diabolical point with topological character. Evolution of the Hofstadter spectrum of this three band system with interband coupling strength is presented and discussed.

Discriminant locality preserving projections based on L1-norm maximization.

PubMed

Zhong, Fujin; Zhang, Jiashu; Li, Defang

2014-11-01

Conventional discriminant locality preserving projection (DLPP) is a dimensionality reduction technique based on manifold learning, which has demonstrated good performance in pattern recognition. However, because its objective function is based on the distance criterion using L2-norm, conventional DLPP is not robust to outliers which are present in many applications. This paper proposes an effective and robust DLPP version based on L1-norm maximization, which learns a set of local optimal projection vectors by maximizing the ratio of the L1-norm-based locality preserving between-class dispersion and the L1-norm-based locality preserving within-class dispersion. The proposed method is proven to be feasible and also robust to outliers while overcoming the small sample size problem. The experimental results on artificial datasets, Binary Alphadigits dataset, FERET face dataset and PolyU palmprint dataset have demonstrated the effectiveness of the proposed method.

90Sr, 137Cs and (239,240)Pu concentration surface water time series in the Pacific and Indian Oceans--WOMARS results.

PubMed

Povinec, Pavel P; Aarkrog, Asker; Buesseler, Ken O; Delfanti, Roberta; Hirose, Katsumi; Hong, Gi Hoon; Ito, Toshimichi; Livingston, Hugh D; Nies, Hartmut; Noshkin, Victor E; Shima, Shigeki; Togawa, Orihiko

2005-01-01

Under an IAEA's Co-ordinated Research Project "Worldwide Marine Radioactivity Studies (WOMARS)" 90Sr, 137Cs and (239,240)Pu concentration surface water time series in the Pacific and Indian Oceans have been investigated. The Pacific and Indian Oceans were divided into 17 latitudinal boxes according to ocean circulation, global fallout patterns and the location of nuclear weapons test sites. The present levels and time trends in radionuclide concentrations in surface water for each box were studied and the corresponding effective half-lives were estimated. For the year 2000, the estimated average 90Sr, 137Cs and (239,240)Pu concentrations in surface waters of the Pacific and Indian Oceans varied from 0.1 to 1.5 mBq/L, 0.1 to 2.8 mBq/L, and 0.1 to 5.2 microBq/L, respectively. The mean effective half-lives for 90Sr and 137Cs in surface water were 12+/-1 years for the North, 20+/-1 years for the South and 21+/-2 years for the Equatorial Pacific. For (239,240)Pu the corresponding mean effective half-lives were 7+/-1 years for the North, 12+/-4 years for the South and 10+/-2 years for the Equatorial Pacific. For the Indian Ocean the mean effective half-lives of 137Cs and (239,240)Pu were 21+/-2 years and 9+/-1 years, respectively. There is evidence that fallout removal rates before 1970 were faster than those observed during recent decades. The estimated surface water concentrations of 90Sr, 137Cs and (239,240)Pu in latitudinal belts of the Pacific and Indian Oceans for the year 2000 may be used as the average levels so that any new contribution from nuclear facilities, nuclear weapons test sites, radioactive waste dumping sites and from possible nuclear accidents can be identified.

Effective Educational Videos: Principles and Guidelines for Maximizing Student Learning from Video Content.

PubMed

Brame, Cynthia J

Educational videos have become an important part of higher education, providing an important content-delivery tool in many flipped, blended, and online classes. Effective use of video as an educational tool is enhanced when instructors consider three elements: how to manage cognitive load of the video; how to maximize student engagement with the video; and how to promote active learning from the video. This essay reviews literature relevant to each of these principles and suggests practical ways instructors can use these principles when using video as an educational tool. © 2016 C. J. Brame. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Undulatory physical resistance training program increases maximal strength in elderly type 2 diabetics.

PubMed

Santos, Gilberto Monteiro dos; Montrezol, Fábio Tanil; Pauli, Luciana Santos Souza; Sartori-Cintra, Angélica Rossi; Colantonio, Emilson; Gomes, Ricardo José; Marinho, Rodolfo; Moura, Leandro Pereira de; Pauli, José Rodrigo

2014-01-01

To investigate the effects of a specific protocol of undulatory physical resistance training on maximal strength gains in elderly type 2 diabetics. The study included 48 subjects, aged between 60 and 85 years, of both genders. They were divided into two groups: Untrained Diabetic Elderly (n=19) with those who were not subjected to physical training and Trained Diabetic Elderly (n=29), with those who were subjected to undulatory physical resistance training. The participants were evaluated with several types of resistance training's equipment before and after training protocol, by test of one maximal repetition. The subjects were trained on undulatory resistance three times per week for a period of 16 weeks. The overload used in undulatory resistance training was equivalent to 50% of one maximal repetition and 70% of one maximal repetition, alternating weekly. Statistical analysis revealed significant differences (p<0.05) between pre-test and post-test over a period of 16 weeks. The average gains in strength were 43.20% (knee extension), 65.00% (knee flexion), 27.80% (supine sitting machine), 31.00% (rowing sitting), 43.90% (biceps pulley), and 21.10% (triceps pulley). Undulatory resistance training used with weekly different overloads was effective to provide significant gains in maximum strength in elderly type 2 diabetic individuals.

The simulation of the half-dry stroke based on the force feedback technology

NASA Astrophysics Data System (ADS)

Guo, Chao; Hou, Zeng-xuan; Zheng, Shuan-zhu; Yang, Guang-qing

2017-02-01

A novel stroke simulation method of the Half-dry style of Chinese calligraphy based on the force feedback technology is proposed for the virtual painting. Firstly, according to the deformation of the brush when the force is exerted on it, the brush footprint between the brush and paper is calculated. The complete brush stroke is obtained by superimposing brush footprints along the painting direction, and the dynamic painting of the brush stroke is implemented. Then, we establish the half-dry texture databases and propose the concept of half-dry value by researching the main factors that affect the effects of the half-dry stroke. In the virtual painting, the half-dry texture is mapped into the stroke in real time according to the half-dry value and painting technique. A technique of texture blending based on the KM model is applied to avoid the seams while texture mapping. The proposed method has been successfully applied to the virtual painting system based on the force feedback technology. In this system, users can implement the painting in real time with a Phantom Desktop haptic device, which can effectively enhance reality to users.

Thermodynamic efficiency of solar concentrators.

PubMed

Shatz, Narkis; Bortz, John; Winston, Roland

2010-04-26

The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency.

Striking Effects of Storage Buffers on Apparent Half-Lives of the Activity of Pseudomonas aeruginosa Arylsulfatase.

PubMed

Li, Yuwei; Yang, Xiaolan; Wang, Deqiang; Hu, Xiaolei; Yuan, Mei; Pu, Jun; Zhan, Chang-Guo; Yang, Zhaoyong; Liao, Fei

2016-08-01

To obtain the label enzyme for enzyme-linked-immunoabsorbent-assay of two components each time in one well with conventional microplate readers, molecular engineering of Pseudomonas aeruginosa arylsulfatase (PAAS) is needed. To compare thermostability of PAAS/mutants of limited purity, effects of buffers on the half-activity time (t 0.5) at 37 °C were tested. At pH 7.4, PAAS showed non-exponential decreases of activity, with the apparent t 0.5 of ~6.0 days in 50 mM HEPES, but ~42 days in 10 mM sodium borate with >85 % activity after 15 days; protein concentrations in both buffers decreased at slower rates after there were significant decreases of activities. Additionally, the apparent t 0.5 of PAAS was ~14 days in 50 mM Tris-HCl, and ~21 days in 10 mM sodium phosphate. By sodium dodecyl-polyacrylamide gel electrophoresis, the purified PAAS gave single polypeptide; after storage for 14 days at 37 °C, there were many soluble and insoluble fragmented polypeptides in the HEPES buffer, but just one principal insoluble while negligible soluble fragmented polypeptides in the borate buffer. Of tested mutants in the neutral borate buffer, rates for activity decreases and polypeptide degradation were slower than in the HEPES buffer. Hence, dilute neutral borate buffers were favorable for examining thermostability of PAAS/mutants.

Linear discriminant analysis based on L1-norm maximization.

PubMed

Zhong, Fujin; Zhang, Jiashu

2013-08-01

Linear discriminant analysis (LDA) is a well-known dimensionality reduction technique, which is widely used for many purposes. However, conventional LDA is sensitive to outliers because its objective function is based on the distance criterion using L2-norm. This paper proposes a simple but effective robust LDA version based on L1-norm maximization, which learns a set of local optimal projection vectors by maximizing the ratio of the L1-norm-based between-class dispersion and the L1-norm-based within-class dispersion. The proposed method is theoretically proved to be feasible and robust to outliers while overcoming the singular problem of the within-class scatter matrix for conventional LDA. Experiments on artificial datasets, standard classification datasets and three popular image databases demonstrate the efficacy of the proposed method.

The effect of physician and health plan market concentration on prices in commercial health insurance markets.

PubMed

Schneider, John E; Li, Pengxiang; Klepser, Donald G; Peterson, N Andrew; Brown, Timothy T; Scheffler, Richard M

2008-03-01

The objective of this paper is to describe the market structure of health plans (HPs) and physician organizations (POs) in California, a state with high levels of managed care penetration and selective contracting. First we calculate Herfindahl-Hirschman (HHI) concentration indices for HPs and POs in 42 California counties. We then estimate a multivariable regression model to examine the relationship between concentration measures and the prices paid by HPs to POs. Price data is from Medstat MarketScan databases. The findings show that any California counties exhibit what the Department of Justice would consider high HHI concentration measures, in excess of 1,800. More than three quarters of California counties exhibit HP concentration indices over 1,800, and 83% of counties have PO concentration levels in excess of 1,800. Half of the study counties exhibited PO concentration levels in excess of 3,600, compared to only 24% for plans. Multivariate price models suggest that PO concentration is associated with higher physician prices (p < or = 0.05), whereas HP concentration does not appear to be significantly associated with higher outpatient commercial payer prices.

Optical measurements of Na-Ca-K exchange currents in intact outer segments isolated from bovine retinal rods

PubMed Central

1991-01-01

The properties of Na-Ca-K exchange current through the plasma membrane of intact rod outer segments (ROS) isolated from bovine retinas were studied with the optical probe neutral red. Small cellular organelles such as bovine ROS do not offer an adequate collecting area to measure Na-Ca-K exchange currents with electrophysiological techniques. This study demonstrates that Na-Ca-K exchange current in bovine ROS can be measured with the dye neutral red and dual-wavelength spectrophotometry. The binding of neutral red is sensitive to transport of cations across the plasma membrane of ROS by the effect of the translocated cations on the surface potential of the intracellular disk membranes (1985. J. Membr. Biol. 88: 249-262). Electrogenic Na+ fluxes through the ROS plasma membrane were measured with a resolution of 10(5) Na+ ions/ROS per s, equivalent to a current of approximately 0.01 pA; maximal electrogenic Na-Ca-K exchange flux in bovine ROS was equivalent to a maximal exchange current of 1-2 pA. Electrogenic Na+ fluxes were identified as Na-Ca-K exchange current based on a comparison between electrogenic Na+ flux and Na(+)-stimulated Ca2+ release with respect to flux rate, Na+ dependence, and ion selectivity. Neutral red monitored the net entry of a single positive charge carried by Na+ for each Ca2+ ion released (i.e., monitored the Na-Ca-K exchange current). Na-Ca-K exchange in the plasma membrane of bovine ROS had the following properties: (a) Inward Na-Ca-K exchange current required internal Ca2+ (half-maximal stimulation at a free Ca2+ concentration of 0.9 microM), whereas outward Na-Ca-K exchange current required both external Ca2+ (half-maximal stimulation at a free Ca2+ concentration of 1.1 microM) and external K+. (b) Inward Na-Ca-K exchange current depended in a sigmoidal manner on the external Na+ concentration, identical to Na(+)-stimulated Ca2+ release measured with Ca(2+)- indicating dyes. (c) The neutral red method was modified to measure Ca(2

Aging and loss decision making: increased risk aversion and decreased use of maximizing information, with correlated rationality and value maximization

PubMed Central

Kurnianingsih, Yoanna A.; Sim, Sam K. Y.; Chee, Michael W. L.; Mullette-Gillman, O’Dhaniel A.

2015-01-01

We investigated how adult aging specifically alters economic decision-making, focusing on examining alterations in uncertainty preferences (willingness to gamble) and choice strategies (what gamble information influences choices) within both the gains and losses domains. Within each domain, participants chose between certain monetary outcomes and gambles with uncertain outcomes. We examined preferences by quantifying how uncertainty modulates choice behavior as if altering the subjective valuation of gambles. We explored age-related preferences for two types of uncertainty, risk, and ambiguity. Additionally, we explored how aging may alter what information participants utilize to make their choices by comparing the relative utilization of maximizing and satisficing information types through a choice strategy metric. Maximizing information was the ratio of the expected value of the two options, while satisficing information was the probability of winning. We found age-related alterations of economic preferences within the losses domain, but no alterations within the gains domain. Older adults (OA; 61–80 years old) were significantly more uncertainty averse for both risky and ambiguous choices. OA also exhibited choice strategies with decreased use of maximizing information. Within OA, we found a significant correlation between risk preferences and choice strategy. This linkage between preferences and strategy appears to derive from a convergence to risk neutrality driven by greater use of the effortful maximizing strategy. As utility maximization and value maximization intersect at risk neutrality, this result suggests that OA are exhibiting a relationship between enhanced rationality and enhanced value maximization. While there was variability in economic decision-making measures within OA, these individual differences were unrelated to variability within examined measures of cognitive ability. Our results demonstrate that aging alters economic decision

Aging and loss decision making: increased risk aversion and decreased use of maximizing information, with correlated rationality and value maximization.

PubMed

Kurnianingsih, Yoanna A; Sim, Sam K Y; Chee, Michael W L; Mullette-Gillman, O'Dhaniel A

2015-01-01

We investigated how adult aging specifically alters economic decision-making, focusing on examining alterations in uncertainty preferences (willingness to gamble) and choice strategies (what gamble information influences choices) within both the gains and losses domains. Within each domain, participants chose between certain monetary outcomes and gambles with uncertain outcomes. We examined preferences by quantifying how uncertainty modulates choice behavior as if altering the subjective valuation of gambles. We explored age-related preferences for two types of uncertainty, risk, and ambiguity. Additionally, we explored how aging may alter what information participants utilize to make their choices by comparing the relative utilization of maximizing and satisficing information types through a choice strategy metric. Maximizing information was the ratio of the expected value of the two options, while satisficing information was the probability of winning. We found age-related alterations of economic preferences within the losses domain, but no alterations within the gains domain. Older adults (OA; 61-80 years old) were significantly more uncertainty averse for both risky and ambiguous choices. OA also exhibited choice strategies with decreased use of maximizing information. Within OA, we found a significant correlation between risk preferences and choice strategy. This linkage between preferences and strategy appears to derive from a convergence to risk neutrality driven by greater use of the effortful maximizing strategy. As utility maximization and value maximization intersect at risk neutrality, this result suggests that OA are exhibiting a relationship between enhanced rationality and enhanced value maximization. While there was variability in economic decision-making measures within OA, these individual differences were unrelated to variability within examined measures of cognitive ability. Our results demonstrate that aging alters economic decision-making for

Acute effect of different concentrations of cayenne pepper cataplasm on sensory-motor functions and serum levels of inflammation-related biomarkers in healthy subjects.

PubMed

Sarabon, Nejc; Löfler, Stefan; Cvecka, Jan; Hübl, Wolfgang; Zampieri, Sandra

2018-01-12

Physical medicine therapies are often used in treating widespread musculoskeletal disorders, such as neck and low back pain. Herbal cataplasms containing rubefacient substances, such as Cayenne pepper, or galenic preparations like Munari cataplasm are commonly used as natural medications to treat painful areas. In this paper we show the effects of a 20-min application of Cayenne pepper and kaolin powder cataplasm (CPC) on healthy subjects. Treatment effects were evaluated by cold/hot feeling on visual analogue scale, blood pressure, body temperature, skin light touch sensations, two-point discrimination, and pain threshold to a mechanical stimulus, before and immediately after, 15 min after and 30 min after different concentration of Cayenne pepper in CPC preparation on healthy subjects. Maximal voluntary trunk extension force and trunk extension submaximal force matching error were also measured. In addition, the resulting optimal CPC mixture was tested for its safety by measuring changes in circulating levels of inflammatory-related biomarkers after 20-min application. The results indicate that the 5% concentration of Cayenne pepper in the preparation of CPC is the best choice, since no additional effects can be obtained with the 10% concentration, and the effects are higher than those observed at the 2.5% concentration. Importantly, 5% CPC application did not induce a significant increase of inflammatory-related biomarkers, suggesting that 20-min application has no negative side effects at systemic levels. Further studies are needed to investigate the immediate and long-term effects of repeated CPC applications as well as to understand the intersecting underlying mechanisms activated by Capsaicin and other identified factors, in order to be more extensively used in the field of physical medicine therapies.

Linear bunchers and half-frequency bunching method

NASA Astrophysics Data System (ADS)

Tang, J. Y.; Jiang, J. Z.; Shi, A. M.; Yin, Z. K.; Wang, Y. F.

2000-12-01

A new buncher system consisting of two bunchers has been designed and constructed for HIRFL injector cyclotron, working at the SFC acceleration modes of H=1 and H=3, respectively. The bunchers use saw-tooth RF waveform, but with double-gap drift tube electrodes and single-gap grid electrodes, respectively. The special merit of the design is introduction of the half-frequency bunching mode, utilizing half of the cyclotron RF frequency. With this method, a perfect longitudinal match between the injector SFC and the main cyclotron SSC has been reached theoretically, compared to the original efficiency of 50% for most cases. Detailed studies have been made concerning space charge effects, longitudinal dispersions through the yoke hole and the spiral inflector, and non-linearity in both the RF waveform and the stray electric field of electrodes.

Assessment of the Combined Treatment with Umbelliferone and Four Classical Antiepileptic Drugs Against Maximal Electroshock-Induced Seizures in Mice.

PubMed

Zagaja, Mirosław; Andres-Mach, Marta; Skalicka-Woźniak, Krystyna; Rękas, Anna R; Kondrat-Wróbel, Maria W; Gleńsk, Michał; Łuszczki, Jarogniew J

2015-01-01

The aim of this study was to determine the effects of umbelliferone (7-hydroxycoumarin; UMB) on the anticonvulsant potency of four classical antiepileptic drugs (carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB) and valproate (VPA)) in the mouse maximal electroshock-induced seizure (MES) model. UMB administered systemically intraperitoneally (ip) in a dose of 150 mg/kg significantly elevated the threshold for maximal electroconvulsions (p < 0.05) in mice. Moreover, UMB (150 mg/kg) co-administered with PB and VPA significantly enhanced the anticonvulsant potency of these drugs by reducing their median effective doses (ED50 values) from 35.39 to 21.78 mg/kg (p < 0.01) for PB, and from 281.4 to 215.5 mg/kg (p < 0.01) for VPA. In contrast, UMB (150 mg/kg, ip) had no significant effect on the antiseizure activity of CBZ and PHT in the mouse MES model. Neither total brain PB, nor total brain VPA concentrations were altered after ip administration of UMB, indicating a pharmacodynamic nature of interactions between the tested drugs. The selective potentiation of the anticonvulsant potency of PB and VPA by UMB, and lack of any pharmacokinetic interactions between drugs, make the combinations of UMB with PB or VPA worthy of consideration for epileptic patients who are refractory to standard antiepileptic treatment. © 2015 S. Karger AG, Basel.

Specificity of a Maximal Step Exercise Test

ERIC Educational Resources Information Center

Darby, Lynn A.; Marsh, Jennifer L.; Shewokis, Patricia A.; Pohlman, Roberta L.

2007-01-01

To adhere to the principle of "exercise specificity" exercise testing should be completed using the same physical activity that is performed during exercise training. The present study was designed to assess whether aerobic step exercisers have a greater maximal oxygen consumption (max VO sub 2) when tested using an activity specific, maximal step…

Maximal Oxygen Uptake, Sweating and Tolerance to Exercise in the Heat

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Castle, B. L.; Ruff, W. K.

1972-01-01

The physiological mechanisms that facilitate acute acclimation to heat have not been fully elucidated, but the result is the establishment of a more efficient cardiovascular system to increase heat dissipation via increased sweating that allows the acclimated man to function with a cooler internal environment and to extend his performance. Men in good physical condition with high maximal oxygen uptakes generally acclimate to heat more rapidly and retain it longer than men in poorer condition. Also, upon first exposure trained men tolerate exercise in the heat better than untrained men. Both resting in heat and physical training in a cool environment confer only partial acclimation when first exposed to work in the heat. These observations suggest separate additive stimuli of metabolic heat from exercise and environmental heat to increase sweating during the acclimation process. However, the necessity of utilizing physical exercise during acclimation has been questioned. Bradbury et al. (1964) have concluded exercise has no effect on the course of heat acclimation since increased sweating can be induced by merely heating resting subjects. Preliminary evidence suggests there is a direct relationship between the maximal oxygen uptake and the capacity to maintain thermal regulation, particularly through the control of sweating. Since increased sweating is an important mechanism for the development of heat acclimation, and fit men have high sweat rates, it follows that upon initial exposure to exercise in the heat, men with high maximal oxygen uptakes should exhibit less strain than men with lower maximal oxygen uptakes. The purpose of this study was: (1) to determine if men with higher maximal oxygen uptakes exhibit greater tolerance than men with lower oxygen uptakes during early exposure to exercise in the heat, and (2) to investigate further the mechanism of the relationship between sweating and maximal work capacity.

Modulation of Mg2+ influx and cytoplasmic free Mg2+ concentration in rat ventricular myocytes.

PubMed

Tashiro, Michiko; Inoue, Hana; Konishi, Masato

2018-06-16

To examine whether TRPM7, a member of the melastatin family of transient receptor potential channels, is a physiological pathway for Mg 2+ entry in mammalian cells, we studied the effect of TRPM7 regulators on cytoplasmic free Mg 2+ concentration ([Mg 2+ ] i ) of rat ventricular myocytes. Acutely isolated single cells were AM-loaded with the fluorescent indicator furaptra, and [Mg 2+ ] i was estimated at 25 °C. After [Mg 2+ ] i was lowered by soaking the cells with a high-K + and Mg 2+ -Ca 2+ -free solution, [Mg 2+ ] i was recovered by extracellular perfusion of Ca 2+ -free Tyrode's solution that contained 1 mM Mg 2+ . The initial rate of increase in [Mg 2+ ] i was analyzed as the Mg 2+ influx rate. The Mg 2+ influx rate was increased by the TRPM7 activator, naltriben (2-50 μM), in a concentration-dependent manner with a half maximal effective concentration (EC 50 ) of 24 μM. This EC 50 value is similar to that reported for the activation of recombinant TRPM7 overexpressed in HEK293 cells. Naltriben (50 μM) caused little change in basal [Mg 2+ ] i (~ 0.9 mM) in Ca 2+ -free Tyrode's solution, but significantly raised [Mg 2+ ] i to 1.31 ± 0.03 mM in 94 min after the removal of extracellular Na + . Re-introduction of extracellular Na + lowered [Mg 2+ ] i back to the basal level even in the presence of naltriben. Application of 10 μM NS8593, an inhibitor of TRPM7, significantly lowered [Mg 2+ ] i to 0.72 ± 0.03 mM in 50-60 min independent of extracellular Na + . The results suggest that Mg 2+ entry through TRPM7 significantly contributes to physiological Mg 2+ homeostasis in mammalian heart cells.

Older men are more fatigable than young when matched for maximal power and knee extension angular velocity is unconstrained.

PubMed

Dalton, Brian H; Power, Geoffrey A; Paturel, Justin R; Rice, Charles L

2015-06-01

The underlying factors related to the divergent findings of age-related fatigue for dynamic tasks are not well understood. The purpose here was to investigate age-related fatigability and recovery between a repeated constrained (isokinetic) and an unconstrained velocity (isotonic) task, in which participants performed fatiguing contractions at the velocity (isokinetic) or resistance (isotonic) corresponding with maximal power. To compare between tasks, isotonic torque-power relationships were constructed prior to and following both fatiguing tasks and during short-term recovery. Contractile properties were recorded from 9 old (~75 years) and 11 young (~25 years) men during three testing sessions. In the first session, maximal power was assessed, and sessions 2 and 3 involved an isokinetic or an isotonic concentric fatigue task performed until maximal power was reduced by 40 %. Compared with young, the older men performed the same number of contractions to task failure for the isokinetic task (~45 contractions), but 20 % fewer for the isotonic task (p < 0.05). Regardless of age and task, maximal voluntary isometric contraction strength, angular velocity, and power were reduced by ~30, ~13, and ~25 %, respectively, immediately following task failure, and only isometric torque was not recovered fully by 10 min. In conclusion, older men are more fatigable than the young when performing a repetitive maximal dynamic task at a relative resistance (isotonic) but not an absolute velocity (isokinetic), corresponding to maximal power.

Effects of Volatile Aromatic Anesthetics on Voltage-Gated Na+ Channels Expressed in Xenopus Oocytes

PubMed Central

Horishita, Takafumi; Eger, Edmond I; Harris, R. Adron

2008-01-01

Background Many inhaled anesthetics inhibit voltage-gated sodium channels at clinically relevant concentrations, and suppression of neurotransmitter release by these agents results, at least partly, from decreased presynaptic sodium channel activity. Volatile aromatic anesthetics can inhibit N-methyl-D-aspartate (NMDA) receptor function and enhance γ-amino butyric acid A (GABAA) receptor function, but these effects depend strongly on the chemical properties of the aromatic ompounds. The present study tested whether diverse aromatic anesthetics consistently inhibit sodium channel function. Methods We studied the effect of eight aromatic anesthetics on Nav1.2 sodium channels with β1 subunits, using whole-cell, two-electrode voltage-clamp techniques in Xenopus oocytes. Results All aromatic anesthetics inhibited INa (sodium currents) at a holding potential which produce half-maximal current (V1/2) (partial depolarization); inhibition was modest with 1,3,5-trifluorobenzene (8 ± 2%), pentafluorobenzene (13 ± 2%), and hexafluorobenzene (13 ± 2%), but greater with benzene (37 ± 2%), fluorobenzene (39 ± 2%), 1,2-difluorobenzene (48 ± 2%), 1,4-difluorobenzene (31 ± 3%), and 1,2,4-trifluorobenzene (33 ± 1%). Such dichotomous effects were noted by others for NMDA and GABAA receptors. Parallel, but much smaller inhibition, was found for INa at a holding potential which produced near maximal current (−90 mV) (VH-90), and hexafluorobenzene caused small (6 ± 1%) potentiation of this current. These changes in sodium channel function were correlated with effectiveness for inhibiting NMDA receptors, with lipid solubility of the compounds, with molecular volume, and with cation-π interactions. Conclusion Aromatic compounds vary in their actions on the kinetics of sodium channel gating and this may underlie their variable inhibition. The range of inhibition produced by MAC concentrations of inhaled anesthetics indicates that sodium channel inhibition may underlie the

Intramuscular pressure and torque during isometric, concentric and eccentric muscular activity

NASA Technical Reports Server (NTRS)

Styf, J.; Ballard, R.; Aratow, M.; Crenshaw, A.; Watenpaugh, D.; Hargens, A. R.

1995-01-01

Intramuscular pressures, electromyography (EMG) and torque generation during isometric, concentric and eccentric maximal isokinetic muscle activity were recorded in 10 healthy volunteers. Pressure and EMG activity were continuously and simultaneously measured side by side in the tibialis anterior and soleus muscles. Ankle joint torque and position were monitored continuously by an isokinetic dynamometer during plantar flexion and dorsiflexion of the foot. The increased force generation during eccentric muscular activity, compared with other muscular activity, was not accompanied by higher intramuscular pressure. Thus, this study demonstrated that eccentric muscular activity generated higher torque values for each increment of intramuscular pressure. Intramuscular pressures during antagonistic co-activation were significantly higher in the tibilis anterior muscle (42-46% of maximal agonistic activity) compared with the soleus muscle (12-29% of maximal agonistic activity) and was largely due to active recruitment of muscle fibers. In summary, eccentric muscular activity creates higher torque values with no additional increase of the intramuscular pressure compared with concentric and isometric muscular activity.

The Effects of Acetate Buffer Concentration on Lysozyme Solubility

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth L.; Pusey, Marc L.

1996-01-01

The micro-solubility column technique was employed to systematically investigate the effects of buffer concentration on tetragonal lysozyme solubility. While keeping the NaCl concentrations constant at 2%, 3%, 4%, 5% and 7%, and the pH at 4.0, we have studied the solubility of tetragonal lysozyme over an acetate buffer concentration range of 0.01M to 0.5M as a function of temperature. The lysozyme solubility decreased with increasing acetate concentration from 0.01M to 0.1M. This decrease may simply be due to the net increase in solvent ionic strength. Increasing the acetate concentration beyond 0.1M resulted in an increase in the lysozyme solubility, which reached a peak at - 0.3M acetate concentration. This increase was believed to be due to the increased binding of acetate to the anionic binding sites of lysozyme, preventing their occupation by chloride. In keeping with the previously observed reversal of the Hoffmeister series for effectiveness of anions in crystallizing lysozyme, acetate would be a less effective precipitant than chloride. Further increasing the acetate concentration beyond 0.3M resulted in a subsequent gradual decrease in the lysozyme solubility at all NaCl concentrations.

Characterization of egg white antibacterial properties during the first half of incubation: A comparative study between embryonated and unfertilized eggs.

PubMed

Guyot, N; Réhault-Godbert, S; Slugocki, C; Harichaux, G; Labas, V; Helloin, E; Nys, Y

2016-12-01

Egg white is an important contributor to the protection of eggs against bacterial contaminations during the first half of incubation (day zero to 12), prior to the egg white transfer into the amniotic fluid to be orally absorbed by the embryo. This protective system relies on an arsenal of antimicrobial proteins and on intrinsic physicochemical properties that are generally unfavorable for bacterial multiplication and dissemination. Some changes in these parameters can be observed in egg white during egg storage and incubation. The aim of this work was to characterize changes in the antibacterial potential of egg white in embryonated eggs (FE) during the first half of incubation using unfertilized eggs (UF) as controls. Egg white samples were collected at day zero, 4, 8, and 12 and analyzed for pH, protein concentration, and protein profile. Antibacterial properties of egg white proteins were evaluated against Listeria monocytogenes, Streptococcus uberis, Staphylococcus aureus, Escherichia coli, and Salmonella Enteritidis. During incubation, differential variations of egg white pH and protein concentrations were observed between UF and FE. At equal protein concentrations, similar activities against L. monocytogenes and S. uberis were observed for FE and UF egg white proteins. A progressive decline in these activities, however, was observed over incubation time, regardless of the egg group (UF or FE). SDS-PAGE analysis of egg white proteins during incubation revealed discrete changes in the profile of major proteins, whereas the stability of some less abundant antimicrobial proteins seemed more affected. To conclude, the antibacterial activity of egg white proteins progressively decreased during the first half of egg incubation, possibly resulting from the alteration of specific antimicrobial proteins. This apparent decline may be partly counterbalanced in embryonated eggs by the increase in egg white protein concentration. The antibacterial potential of egg white

Response to non-uniform salinity in the root zone of the halophyte Atriplex nummularia: growth, photosynthesis, water relations and tissue ion concentrations.

PubMed

Bazihizina, Nadia; Colmer, Timothy D; Barrett-Lennard, Edward G

2009-09-01

Soil salinity is often heterogeneous, yet the physiology of halophytes has typically been studied with uniform salinity treatments. An evaluation was made of the growth, net photosynthesis, water use, water relations and tissue ions in the halophytic shrub Atriplex nummularia in response to non-uniform NaCl concentrations in a split-root system. Atriplex nummularia was grown in a split-root system for 21 d, with either the same or two different NaCl concentrations (ranging from 10 to 670 mm), in aerated nutrient solution bathing each root half. Non-uniform salinity, with high NaCl in one root half (up to 670 mm) and 10 mm in the other half, had no effect on shoot ethanol-insoluble dry mass, net photosynthesis or shoot pre-dawn water potential. In contrast, a modest effect occurred for leaf osmotic potential (up to 30 % more solutes compared with uniform 10 mm NaCl treatment). With non-uniform NaCl concentrations (10/670 mm), 90 % of water was absorbed from the low salinity side, and the reduction in water use from the high salinity side caused whole-plant water use to decrease by about 30 %; there was no compensatory water uptake from the low salinity side. Leaf Na(+) and Cl(-) concentrations were 1.9- to 2.3-fold higher in the uniform 670 mm treatment than in the 10/670 mm treatment, whereas leaf K(+) concentrations were 1.2- to 2.0-fold higher in the non-uniform treatment. Atriplex nummularia with one root half in 10 mm NaCl maintained net photosynthesis, shoot growth and shoot water potential even when the other root half was exposed to 670 mm NaCl, a concentration that inhibits growth by 65 % when uniform in the root zone. Given the likelihood of non-uniform salinity in many field situations, this situation would presumably benefit halophyte growth and physiology in saline environments.

Response to non-uniform salinity in the root zone of the halophyte Atriplex nummularia: growth, photosynthesis, water relations and tissue ion concentrations

PubMed Central

Bazihizina, Nadia; Colmer, Timothy D.; Barrett-Lennard, Edward G.

2009-01-01

Background and Aims Soil salinity is often heterogeneous, yet the physiology of halophytes has typically been studied with uniform salinity treatments. An evaluation was made of the growth, net photosynthesis, water use, water relations and tissue ions in the halophytic shrub Atriplex nummularia in response to non-uniform NaCl concentrations in a split-root system. Methods Atriplex nummularia was grown in a split-root system for 21 d, with either the same or two different NaCl concentrations (ranging from 10 to 670 mm), in aerated nutrient solution bathing each root half. Key Results Non-uniform salinity, with high NaCl in one root half (up to 670 mm) and 10 mm in the other half, had no effect on shoot ethanol-insoluble dry mass, net photosynthesis or shoot pre-dawn water potential. In contrast, a modest effect occurred for leaf osmotic potential (up to 30 % more solutes compared with uniform 10 mm NaCl treatment). With non-uniform NaCl concentrations (10/670 mm), 90 % of water was absorbed from the low salinity side, and the reduction in water use from the high salinity side caused whole-plant water use to decrease by about 30 %; there was no compensatory water uptake from the low salinity side. Leaf Na+ and Cl− concentrations were 1·9- to 2·3-fold higher in the uniform 670 mm treatment than in the 10/670 mm treatment, whereas leaf K+ concentrations were 1·2- to 2·0-fold higher in the non-uniform treatment. Conclusions Atriplex nummularia with one root half in 10 mm NaCl maintained net photosynthesis, shoot growth and shoot water potential even when the other root half was exposed to 670 mm NaCl, a concentration that inhibits growth by 65 % when uniform in the root zone. Given the likelihood of non-uniform salinity in many field situations, this situation would presumably benefit halophyte growth and physiology in saline environments. PMID:19556265

Using Maximal Isometric Force to Determine the Optimal Load for Measuring Dynamic Muscle Power

NASA Technical Reports Server (NTRS)

Spiering, Barry A.; Lee, Stuart M. C.; Mulavara, Ajitkumar P.; Bentley, Jason R.; Nash, Roxanne E.; Sinka, Joseph; Bloomberg, Jacob J.

2009-01-01

Maximal power output occurs when subjects perform ballistic exercises using loads of 30-50% of one-repetition maximum (1-RM). However, performing 1-RM testing prior to power measurement requires considerable time, especially when testing involves multiple exercises. Maximal isometric force (MIF), which requires substantially less time to measure than 1-RM, might be an acceptable alternative for determining the optimal load for power testing. PURPOSE: To determine the optimal load based on MIF for maximizing dynamic power output during leg press and bench press exercises. METHODS: Twenty healthy volunteers (12 men and 8 women; mean +/- SD age: 31+/-6 y; body mass: 72 +/- 15 kg) performed isometric leg press and bench press movements, during which MIF was measured using force plates. Subsequently, subjects performed ballistic leg press and bench press exercises using loads corresponding to 20%, 30%, 40%, 50%, and 60% of MIF presented in randomized order. Maximal instantaneous power was calculated during the ballistic exercise tests using force plates and position transducers. Repeated-measures ANOVA and Fisher LSD post hoc tests were used to determine the load(s) that elicited maximal power output. RESULTS: For the leg press power test, six subjects were unable to be tested at 20% and 30% MIF because these loads were less than the lightest possible load (i.e., the weight of the unloaded leg press sled assembly [31.4 kg]). For the bench press power test, five subjects were unable to be tested at 20% MIF because these loads were less than the weight of the unloaded aluminum bar (i.e., 11.4 kg). Therefore, these loads were excluded from analysis. A trend (p = 0.07) for a main effect of load existed for the leg press exercise, indicating that the 40% MIF load tended to elicit greater power output than the 60% MIF load (effect size = 0.38). A significant (p . 0.05) main effect of load existed for the bench press exercise; post hoc analysis indicated that the effect of

RBC-/Cr-51/ half-life and albumin turnover in growing Beagle dogs during chronic radial acceleration

NASA Technical Reports Server (NTRS)

Beckman, D. A.; Evans, J. W.; Oyama, J.

1979-01-01

The effects of chronic centrifugation on growing Beagle dogs exposed to -2 or -2.6 Gx on albumin and RBC turnover rates, albumin concentration and space, and total blood volume were determined and compared with caged and run control of animals. Albumin-(I-125) and autologous RBC-(Cr-51) preparations were injected into all dogs at day 82 of the centrifugation periods, and the disappearance curves were determined by successive bleedings of the animals over the next 35 d, during which the centrifugation was continued. There were no differences in albumin turnover rates or space. Two populations of RBCs were found in both centrifugated groups, one with a normal half-life of 27 + or - 1 S.E.M. d, and one with a significantly (p less than 0.01) shorter half-life of 15 + or - 2 S.E.M. d. An absolute polycythemia was also observed in both centrifuged groups. The results suggest that chronic centrifugation acts through some as-yet unknown mechanism to affect RBC population kinetics.

Effects of stand and inter-specific stocking on maximizing standing tree carbon stocks in the eastern United States

Treesearch

Christopher W. Woodall; Anthony W. D' Amato; John B. Bradford; Andrew O. Finley

2011-01-01

There is expanding interest in management strategies that maximize forest carbon (C) storage to mitigate increased atmospheric carbon dioxide. The tremendous tree species diversity and range of stand stocking found across the eastern United States presents a challenge for determining optimal combinations for the maximization of standing tree C storage. Using a...

Effect of Dietary Nitrate Supplementation on Swimming Performance in Trained Swimmers.

PubMed

Lowings, Sam; Shannon, Oliver Michael; Deighton, Kevin; Matu, Jamie; Barlow, Matthew John

2017-08-01

Nitrate supplementation appears to be most ergogenic when oxygen availability is restricted and subsequently may be particularly beneficial for swimming performance due to the breath-hold element of this sport. This represents the first investigation of nitrate supplementation and swimming time-trial (TT) performance. In a randomized double-blind repeated-measures crossover study, ten (5 male, 5 female) trained swimmers ingested 140ml nitrate-rich (~12.5mmol nitrate) or nitrate-depleted (~0.01mmol nitrate) beetroot juice. Three hours later, subjects completed a maximal effort swim TT comprising 168m (8 × 21m lengths) backstroke. Preexercise fractional exhaled nitric oxide concentration was significantly elevated with nitrate compared with placebo, Mean (SD): 17 (9) vs. 7 (3)p.p.b., p = .008. Nitrate supplementation had a likely trivial effect on overall swim TT performance (mean difference 1.22s; 90% CI -0.18-2.6s; 0.93%; p = .144; d = 0.13; unlikely beneficial (22.6%), likely trivial (77.2%), most unlikely negative (0.2%)). The effects of nitrate supplementation during the first half of the TT were trivial (mean difference 0.29s; 90% CI -0.94-1.5s; 0.46%; p = .678; d = 0.05), but there was a possible beneficial effect of nitrate supplementation during the second half of the TT (mean difference 0.93s; 90% CI 0.13-1.70s; 1.36%; p = .062; d = 0.24; possibly beneficial (63.5%), possibly trivial (36.3%), most unlikely negative (0.2%)). The duration and speed of underwater swimming within the performance did not differ between nitrate and placebo (both p > .30). Nitrate supplementation increased nitric oxide bioavailability but did not benefit short-distance swimming performance or the underwater phases of the TT. Further investigation into the effects of nitrate supplementation during the second half of performance tests may be warranted.

Enzymatic properties of separated isozymes of the Na,K-ATPase. Substrate affinities, kinetic cooperativity, and ion transport stoichiometry.

PubMed

Sweadner, K J

1985-09-25

There are two isozymes of the Na,K-ATPase, which can be purified separately from rat renal medulla and brainstem axolemma. Here the basic kinetic properties of the two Na,K-ATPases have been compared in conditions permitting enzyme turnover. The two isozymes are half-maximally activated at different concentrations of ATP, the axolemma Na,K-ATPase having the higher affinity. They are half-maximally activated by Na+ and K+ at very similar concentrations but show differences in cooperativity toward Na+. The affinities of both isozymes for ATP and Na+ are affected in a qualitatively similar way by variations in the concentration of K+. Both isozymes transport 22Na+ and 42K+ in a ratio close to 3:2 in artificial lipid vesicles. The two isozymes differ most strikingly in the inhibition of ATPase activity by ouabain. The axolemma Na,K-ATPase has a high affinity for ouabain with positive cooperativity, while the renal medulla Na,K-ATPase has a lower affinity with negative cooperativity. It is likely that the cooperativity differences are due to kinetic effects, reflecting different rates of conformation transitions during enzyme turnover. The functional result of the contrasting cooperativities is that the difference in sensitivity to ouabain is amplified.

Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. (Araliaceae) as an adaptogen: a closer look.

PubMed

Davydov, M; Krikorian, A D

2000-10-01

The adaptogen concept is examined from an historical, biological, chemical, pharmacological and medical perspective using a wide variety of primary and secondary literature. The definition of an adaptogen first proposed by Soviet scientists in the late 1950s, namely that an adaptogen is any substance that exerts effects on both sick and healthy individuals by 'correcting' any dysfunction(s) without producing unwanted side effects, was used as a point of departure. We attempted to identify critically what an adaptogen supposedly does and to determine whether the word embodies in and of itself any concept(s) acceptable to western conventional (allopathic) medicine. Special attention was paid to the reported pharmacological effects of the 'adaptogen-containing plant' Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. (Araliaceae), referred to by some as 'Siberian ginseng', and to its secondary chemical composition. We conclude that so far as specific pharmacological activities are concerned there are a number of valid arguments for equating the action of so-called adaptogens with those of medicinal agents that have activities as anti-oxidants, and/or anti-cancerogenic, immunomodulatory and hypocholesteroletic as well as hypoglycemic and choleretic action. However, 'adaptogens' and 'anti-oxidants' etc. also show significant dissimilarities and these are discussed. Significantly, the classical definition of an adaptogen has much in common with views currently being invoked to describe and explain the 'placebo effect'. Nevertheless, the chemistry of the secondary compounds of Eleutherococcus isolated thus far and their pharmacological effects support our hypothesis that the reported beneficial effects of adaptogens derive from their capacity to exert protective and/or inhibitory action against free radicals. An inventory of the secondary substances contained in Eleutherococcus discloses a potential for a wide range of activities reported from work on cultured cell lines

Changes in 137Cs concentrations in soil and vegetation on the floodplain of the Savannah River over a 30 year period.

PubMed

Paller, M H; Jannik, G T; Fledderman, P D

2008-08-01

(137)Cs released during 1954-1974 from nuclear production reactors on the Savannah River Site, a US Department of Energy nuclear materials production site in South Carolina, contaminated a portion of the Savannah River floodplain known as Creek Plantation. (137)Cs activity concentrations have been measured in Creek Plantation since 1974 making it possible to calculate effective half-lives for (137)Cs in soil and vegetation and assess the spatial distribution of contaminants on the floodplain. Activity concentrations in soil and vegetation were higher near the center of the floodplain than near the edges as a result of frequent inundation coupled with the presence of low areas that trapped contaminated sediments. (137)Cs activity was highest near the soil surface, but depth related differences diminished with time as a likely result of downward diffusion or leaching. Activity concentrations in vegetation were significantly related to concentrations in soil. The plant to soil concentration ratio (dry weight) averaged 0.49 and exhibited a slight but significant tendency to decrease with time. The effective half-lives for (137)Cs in shallow (0-7.6 cm) soil and in vegetation were 14.9 (95% CI=12.5-17.3) years and 11.6 (95% CI=9.1-14.1) years, respectively, and rates of (137)Cs removal from shallow soil and vegetation did not differ significantly among sampling locations. Potential health risks on the Creek Plantation floodplain have declined more rapidly than expected on the basis of radioactive decay alone because of the relatively short effective half-life of (137)Cs.

Endogenous concentrations, pharmacokinetics, and selected pharmacodynamic effects of a single dose of exogenous GABA in horses.

PubMed

Knych, H K; Steinmetz, S J; McKemie, D S

2015-04-01

The anti-anxiety and calming effects following activation of the GABA receptor have been exploited in performance horses by administering products containing GABA. The primary goal of the study reported here was to describe endogenous concentrations of GABA in horses and the pharmacokinetics, selected pharmacodynamic effects, and CSF concentrations following administration of a GABA-containing product. The mean (±SD) endogenous GABA level was 36.4 ± 12.5 ng/mL (n = 147). Sixteen of these horses received a single intravenous and oral dose of GABA (1650 mg). Blood, urine, and cerebrospinal fluid (n = 2) samples were collected at time 0 and at various times for up to 48 h and analyzed using LC-MS. Plasma clearance and volume of distribution was 155.6 and 147.6 L/h and 0.154 and 7.39 L for the central and peripheral compartments, respectively. Terminal elimination half-life was 22.1 (intravenous) and 25.1 (oral) min. Oral bioavailability was 9.81%. Urine GABA concentrations peaked rapidly returning to baseline levels by 3 h. Horses appeared behaviorally unaffected following oral administration, while sedative-like changes following intravenous administration were transient. Heart rate was increased for 1 h postintravenous administration, and gastrointestinal sounds decreased for approximately 30 min following both intravenous and oral administration. Based on a limited number of horses and time points, exogenously administered GABA does not appear to enter the CSF to an appreciable extent. © 2014 John Wiley & Sons Ltd.

Effects of sucrose concentration and water deprivation on Pavlovian conditioning and responding for conditioned reinforcement.

PubMed

Tabbara, Rayane I; Maddux, Jean-Marie N; Beharry, Priscilla F; Iannuzzi, Jessica; Chaudhri, Nadia

2016-04-01

An appetitive Pavlovian conditioned stimulus (CS) can predict an unconditioned stimulus (US) and acquire incentive salience. We tested the hypothesis that US intensity and motivational state of the subject would influence Pavlovian learning and impact the attribution of incentive salience to an appetitive Pavlovian CS. To this end, we examined the effects of sucrose concentration and water deprivation on the acquisition of Pavlovian conditioning and responding for a conditioned reinforcer. Male Long-Evans rats (Harlan; 220-240 g) receiving 3% (3S) or 20% (20S) sucrose were either non-water deprived or given water for 1 hr per day. During Pavlovian conditioning sessions, half the rats in each concentration and deprivation condition received a 10-s CS paired with 0.2 ml of sucrose (16 trials/session; 3.2 ml/session). The remainder received unpaired CS and US presentations. Entries into a port where sucrose was delivered were recorded. Next, responding for conditioned reinforcement was tested, wherein pressing an active lever produced the CS and pressing an inactive lever had no consequences. CS-elicited port entries increased, and latency to the first CS-elicited port entry decreased across sessions in paired groups. Water deprivation augmented these effects, whereas sucrose concentration had no significant impact on behavior. Responding for conditioned reinforcement was observed in the 20S water-deprived, paired group. Thus, water deprivation can facilitate the acquisition of Pavlovian conditioning, potentially by enhancing motivational state, and a high-intensity US and a high motivational state can interact to heighten the attribution of incentive salience to an appetitive Pavlovian CS. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Gradient Dynamics and Entropy Production Maximization

NASA Astrophysics Data System (ADS)

Janečka, Adam; Pavelka, Michal

2018-01-01

We compare two methods for modeling dissipative processes, namely gradient dynamics and entropy production maximization. Both methods require similar physical inputs-how energy (or entropy) is stored and how it is dissipated. Gradient dynamics describes irreversible evolution by means of dissipation potential and entropy, it automatically satisfies Onsager reciprocal relations as well as their nonlinear generalization (Maxwell-Onsager relations), and it has statistical interpretation. Entropy production maximization is based on knowledge of free energy (or another thermodynamic potential) and entropy production. It also leads to the linear Onsager reciprocal relations and it has proven successful in thermodynamics of complex materials. Both methods are thermodynamically sound as they ensure approach to equilibrium, and we compare them and discuss their advantages and shortcomings. In particular, conditions under which the two approaches coincide and are capable of providing the same constitutive relations are identified. Besides, a commonly used but not often mentioned step in the entropy production maximization is pinpointed and the condition of incompressibility is incorporated into gradient dynamics.

Maximally Expressive Task Modeling

NASA Technical Reports Server (NTRS)

Japp, John; Davis, Elizabeth; Maxwell, Theresa G. (Technical Monitor)

2002-01-01

Planning and scheduling systems organize "tasks" into a timeline or schedule. The tasks are defined within the scheduling system in logical containers called models. The dictionary might define a model of this type as "a system of things and relations satisfying a set of rules that, when applied to the things and relations, produce certainty about the tasks that are being modeled." One challenging domain for a planning and scheduling system is the operation of on-board experiment activities for the Space Station. The equipment used in these experiments is some of the most complex hardware ever developed by mankind, the information sought by these experiments is at the cutting edge of scientific endeavor, and the procedures for executing the experiments are intricate and exacting. Scheduling is made more difficult by a scarcity of space station resources. The models to be fed into the scheduler must describe both the complexity of the experiments and procedures (to ensure a valid schedule) and the flexibilities of the procedures and the equipment (to effectively utilize available resources). Clearly, scheduling space station experiment operations calls for a "maximally expressive" modeling schema. Modeling even the simplest of activities cannot be automated; no sensor can be attached to a piece of equipment that can discern how to use that piece of equipment; no camera can quantify how to operate a piece of equipment. Modeling is a human enterprise-both an art and a science. The modeling schema should allow the models to flow from the keyboard of the user as easily as works of literature flowed from the pen of Shakespeare. The Ground Systems Department at the Marshall Space Flight Center has embarked on an effort to develop a new scheduling engine that is highlighted by a maximally expressive modeling schema. This schema, presented in this paper, is a synergy of technological advances and domain-specific innovations.

Can Monkeys Make Investments Based on Maximized Pay-off?

PubMed Central

Steelandt, Sophie; Dufour, Valérie; Broihanne, Marie-Hélène; Thierry, Bernard

2011-01-01

Animals can maximize benefits but it is not known if they adjust their investment according to expected pay-offs. We investigated whether monkeys can use different investment strategies in an exchange task. We tested eight capuchin monkeys (Cebus apella) and thirteen macaques (Macaca fascicularis, Macaca tonkeana) in an experiment where they could adapt their investment to the food amounts proposed by two different experimenters. One, the doubling partner, returned a reward that was twice the amount given by the subject, whereas the other, the fixed partner, always returned a constant amount regardless of the amount given. To maximize pay-offs, subjects should invest a maximal amount with the first partner and a minimal amount with the second. When tested with the fixed partner only, one third of monkeys learned to remove a maximal amount of food for immediate consumption before investing a minimal one. With both partners, most subjects failed to maximize pay-offs by using different decision rules with each partner' quality. A single Tonkean macaque succeeded in investing a maximal amount to one experimenter and a minimal amount to the other. The fact that only one of over 21 subjects learned to maximize benefits in adapting investment according to experimenters' quality indicates that such a task is difficult for monkeys, albeit not impossible. PMID:21423777

Relationship between traditional and ballistic squat exercise with vertical jumping and maximal sprinting.

PubMed

Requena, Bernardo; García, Inmaculada; Requena, Francisco; de Villarreal, Eduardo Sáez-Sáez; Cronin, John B