The isolation and companion comfort responses of 7- and 3-day-old rat pups are modulated by drugs active at the opioid receptor.

Rat pups emit ultrasonic vocalizations (USVs) when isolated in a novel environment. In 10-day-olds, USV has been shown to be reduced by either the administration of 0.125 mg/kg morphine (MOR) or the presence of a littermate; these effects were both reversed by naltrexone (NLX), an opioid receptor blocker. The present study reports that the same dose of MOR produced NLX-antagonized quieting without sedation in 7- and 3-day-old pups; higher doses of MOR decreased USV but produced motor deficits as well. The 0.125 mg/kg dose of MOR is less effective in reducing USV in 3- and 7-day-olds; calling rates declined by no more than 42%, compared with 65% at 10 days of age. The presence of a companion also lowered the USV of 3- and 7-day-olds by a lesser amount (55–57%) than the 67% seen in 10-day-olds or the 90% decline when pups are 2 weeks old. This suggests that age-related changes in the opioid system may be relevant to the increased salience of a social companion that comes with maturity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transport of methanol in poly(methyl methacrylate)

The transport kinetics of liquid methanol in PMMA sheet (Perspex) have been studied over the temperature range 23° to 63°C. At the lower temperatures the transport is typical Case II; the methanol penetrating the polymer behind a sharp front which moves at constant velocity. For higher temperatures the concentration of methanol at the front and the front velocity both decrease with increasing penetration. These factors, which are no doubt related, combine to give mass absorption kinetics in which the exponent of time is no longer unity (Case II) but approaches 0.5, the value typical of Fickian diffusion. Iodine has been added to the methanol to make the positions of the penetration fronts readily visible. The iodine does not affect either the rate of penetration or the equilibrium absorption. Measurements of colour density profiles on thin cross-sections using a microdensitometer give a reliable indication of the true methanol profile. The rate at which the methanol penetrates the glassy polymer is proportional to its concentration at the advancing fronts. The apparent activation energy for methanol penetration for constant concentration at the fronts is 25 kcal/mol.     

Very-high-precision solutions of a class of Schrödinger type equations

We investigate a method to solve a class of Schrödinger type equation eigenvalue problems numerically to very high precision P (from thousands to a million of decimals). The memory requirement, and the number of high-precision algebraic operations, of the method scale essentially linearly with P when only eigenvalues are computed. However, since the algorithms for multiplying high-precision numbers scale at a rate between P^1.6 and , the time requirement of our method increases somewhat faster than P².     

Recovery from a cycling time trial is enhanced with carbohydrate-protein supplementation vs. isoenergetic carbohydrate supplementation

Background

In this study we assessed whether a liquid carbohydrate-protein (C+P) supplement (0.8 g/kg C; 0.4 g/kg P) ingested early during recovery from a cycling time trial could enhance a subsequent 60 min effort on the same day vs. an isoenergetic liquid carbohydrate (CHO) supplement (1.2 g/kg).

Methods

Two hours after a standardized breakfast, 15 trained male cyclists completed a time trial in which they cycled as far as they could in 60 min (AM_ex) using a Computrainer indoor trainer. Following AM_ex, subjects ingested either C+P, or CHO at 10, 60 and 120 min, followed by a standardized meal at 4 h post exercise. At 6 h post AM_ex subjects repeated the time trial (PM_ex).

Results

There was a significant reduction in performance for both groups in PM_ex versus AM_ex. However, performance and power decreases between PM_ex and AM_ex were significantly greater (p ≤ 0.05) with CHO (-1.05 ± 0.44 km and -16.50 ± 6.74 W) vs C+P (-0.30 ± 0.50 km and -3.86 ± 6.47 W). Fat oxidation estimated from RER values was significantly greater (p ≤ 0.05) in the C+P vs CHO during the PM_ex, despite a higher average workload in the C+P group.

Conclusion

Under these experimental conditions, liquid C+P ingestion immediately after exercise increases fat oxidation, increases recovery, and improves subsequent same day, 60 min efforts relative to isoenergetic CHO ingestion.     

Analytical approach to entropy generation and heat transfer in CNT-nanofluid dynamics through a ciliated porous medium

The transportation of biological and industrial nanofluids by natural propulsion like cilia movement and self-generated contraction-relaxation of flexible walls has significant applications in numerous emerging technologies. Inspired by multi-disciplinary progress and innovation in this direction, a thermo-fluid mechanical model is proposed to study the entropy generation and convective heat transfer of nanofluids fabricated by the dispersion of single-wall carbon nanotubes(SWCNT) nanoparticles in water as the base fluid. The regime studied comprises heat transfer and steady, viscous, incompressible flow, induced by metachronal wave propulsion due to beating cilia, through a cylindrical tube containing a sparse(i.e., high permeability) homogenous porous medium. The flow is of the creeping type and is restricted under the low Reynolds number and long wavelength approximations. Slip effects at the wall are incorporated and the generalized Darcy drag-force model is utilized to mimic porous media effects. Cilia boundary conditions for velocity components are employed to determine analytical solutions to the resulting non-dimensionalized boundary value problem. The influence of pertinent physical parameters on temperature, axial velocity, pressure rise and pressure gradient, entropy generation function, Bejan number and stream-line distributions are computed numerically. A comparative study between SWCNT-nanofluids and pure water is also computed. The computations demonstrate that axial flow is accelerated with increasing slip parameter and Darcy number and is greater for SWCNT-nanofluids than for pure water. Furthermore the size of the bolus for SWCNT-nanofluids is larger than that of the pure water. The study is applicable in designing and fabricating nanoscale and microfluidics devices, artificial cilia and biomimetic micro-pumps.     

Modulation of salt (NaCl)‐induced effects on oil composition and fatty acid profile of sunflower (Helianthus annuus L.) by exogenous application of salicylic acid

BACKGROUND: Salicylic acid (SA) is a potential endogenous plant hormone that plays an important role in plant growth and development. Since sunflower yield and its seed oil yield are adversely affected by salinity, in this study the role of SA in modulating salt (NaCl)‐induced effects on various yield and oil characteristics of sunflower was investigated. For this purpose a greenhouse experiment comprising two sunflower hybrid lines (Hysun‐33 and SF‐187), two NaCl levels (0 and 120 mmol L^?1) and four SA levels (0, 100, 200 and 300 mg L^?1) was conducted. RESULTS: Salt stress markedly reduced yield, oil content, linoleic acid and δ‐tocopherol in both sunflower lines, while it increased linolenic acid, palmitic acid, stearic acid and α‐ and γ‐tocopherols. However, increasing levels of foliar‐applied SA resulted in improved achene yield and hundred‐achene weight in both lines. Foliar‐applied SA caused a significant decrease in oil stearic acid and α‐ and γ‐tocopherols in both lines under non‐saline and saline conditions. CONCLUSION: Salt‐induced harmful effects on achene yield and oil characteristics of sunflower could be alleviated by exogenous application of SA. High doses of SA caused a marked increase in sunflower achene oil content as well as some key fatty acids. Copyright © 2010 Society of Chemical Industry     

Soret‐Dufour effects in electroosmotic biorheological flow of Jeffrey fluid

The Soret and Dufour cross‐diffusion on the electrokinetic flow of Jeffrey fluid augmented with peristalsis have been presented. The fundamental equations are employed to predict the mass distribution in the two‐dimensional asymmetric electroosmotic channel. Reliable approximations such as low Peclet, low Reynolds, and large wavelength are utilized. The analytical solutions of the concentration, temperature, velocity, and stream function are obtained. To predict the effects of prominent parameters such as fluid parameter, electroosmotic parameter, Brinkman, Soret, and Schmidt number graphs are plotted. The phenomenon of trapping is also discussed to observe the behavior on streamlines. It is observed that the electroosmotic parameter enhances the temperature profile. With the increase in Jeffrey fluid parameter, the Nusselt number is decreased. Furthermore, the concentration is decreased with the elevation in Soret and Schmidt numbers. The current study can help reduce the conversion stages necessary for the integration of the low voltage output in an electrokinetic biomass process.     

Influence of heat transfer on the nonorthogonal stagnation point flow of a third‐order fluid towards a stretching surface

The present article looks at the theoretical analysis of a steady stagnation‐point flow with heat transfer of a third‐order fluid towards a stretching surface. The formulation of the problem has been carried out for a third order fluid and constructed partial differential equations are rehabilitated into ordinary differential equations. The consequential ordinary differential equations are solved analytically using the homotopy analysis method (HAM). Graphical illustrations are shown for various parameters involved in the flow equations. Numerical values of skin friction coefficients and heat flux are computed and presented through tables. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21042