Water salinity and air temperature on quail production and organ characteristics

ABSTRACT The supply of salt water in the semiarid region is a recurrent practice, as there is a severe shortage of water for use in animal consumption. Thus, most of the times the water offered to the birds can contain salts above the recommended amount. The present study aimed to evaluate the production performance and morphometry of the organs of Japanese quails as they were supplied with drinking water with different concentrations of sodium chloride, while being maintained in comfort and under thermal stress. The birds received water with increasing electrical conductivity (1.5, 3.0, 4.5 and 6.0 dS m-1) and were kept in a climate chamber at thermoneutral air temperature (24 °C) and under thermal stress (32 °C), being distributed in a completely randomized design and 2 × 4 factorial scheme. Water electrical conductivities did not affect the performance of the birds, except for the weight of the gizzard, which showed an increasing linear effect as the electrical conductivities increased. At the stress temperature, there was reduction in feed intake, egg weight and mass, and in feed conversion per dozen eggs, but with no effect on the weights of the heart, liver and gizzard. Japanese quails in the production phase can consume water with electrical conductivity of up to 6.0 dS m-1, showing good production performance and without compromising organ morphometry.

Magnesium in the water of Japanese quails kept under comfort zone and under thermal stress

The objective was to evaluate the increasing levels of magnesium in the water supplied to laying quails (Coturnix coturnix japonica), kept in climatic chambers under thermoneutral temperature and thermal stress, on their performance and morphometry of their organs. The birds were distributed in a completely randomized design, 2x4 factorial arrangement, 2 temperatures (24 and 32 ºC) and 4 levels of magnesium in the water (50, 150, 250 and 350 mg L-1), with six replicates and eight birds per experimental unit. The data were subjected to analysis of variance and the means compared by the Tukey test at 5% probability level. The magnesium levels in the water did not affect (P > 0.05) the production performance and morphometry of the organs, with less water consumption at the magnesium level of 150 mg L-1, and birds kept at 32 °C had a reduction in feed consumption and feed conversion, but without affecting organ morphometry. Japanese quails in the production phase can consume water with magnesium levels up to 350 mg L-1 without having their production performance and morphometry of organs affected and raised in an environment with temperatures of up to 32 °C.

Easy Fabrication of Performant SWCNT-Si Photodetector

We propose a simple method to fabricate a photodetector based on the carbon nanotube/silicon nitride/silicon (CNT/Si3N4/Si) heterojunction. The device is obtained by depositing a freestanding single-wall carbon nanotube (SWCNT) film on a silicon substrate using a dry transfer technique. The SWCNT/Si3N4/Si heterojunction is formed without the thermal stress of chemical vapor deposition used for the growth of CNTs in other approaches. The CNT film works as a transparent charge collecting electrode and guarantees a uniform photocurrent across the sensitive area of the device. The obtained photodetector shows a great photocurrent that increases linearly with the incident light intensity and grows with the increasing wavelength in the visible range. The external quantum efficiency is independent of the light intensity and increases with the wavelength, reaching 65% at 640 nm.

Thermal stress affects proliferation and differentiation of turkey satellite cells through the mTOR/S6K pathway in a growth-dependent manner

Satellite cells (SCs) are stem cells responsible for post-hatch muscle growth through hypertrophy and in birds are sensitive to thermal stress during the first week after hatch. The mechanistic target of rapamycin (mTOR) signaling pathway, which is highly responsive to thermal stress in differentiating turkey pectoralis major (p. major) muscle SCs, regulates protein synthesis and the activities of SCs through a downstream effector, S6 kinase (S6K). The objectives of this study were: 1) to determine the effect of heat (43°C) and cold (33°C) stress on activity of the mTOR/S6K pathway in SCs isolated from the p. major muscle of one-week-old faster-growing modern commercial (NC) turkeys compared to those from slower-growing Randombred Control Line 2 (RBC2) turkeys, and 2) to assess the effect of mTOR knockdown on the proliferation, differentiation, and expression of myogenic regulatory factors of the SCs. Heat stress increased phosphorylation of both mTOR and S6K in both turkey lines, with greater increases observed in the RBC2 line. With cold stress, greater reductions in mTOR and S6K phosphorylation were observed in the NC line. Early knockdown of mTOR decreased proliferation, differentiation, and expression of myoblast determination protein 1 and myogenin in both lines independent of temperature, with the RBC2 line showing greater reductions in proliferation and differentiation than the NC line at 38° and 43°C. Proliferating SCs are more dependent on mTOR/S6K-mediated regulation than differentiating SCs. Thus, thermal stress can affect breast muscle hypertrophic potential by changing satellite cell proliferation and differentiation, in part, through the mTOR/S6K pathway in a growth-dependent manner. These changes may result in irreversible effects on the development and growth of the turkey p. major muscle.

Numerical simulation of ultrasonic spot welding of superelastic NiTi alloys: Temperature distribution and deformation behavior

Ultrasonic spot welding (USW) has attracted increasing attention due to its high- throughput solid-state bonding mechanism, which shows great potential in the semiconductor and automotive industry for the joining of metal sheets. However, the short welding cycle makes it challenging to effectively monitor the temperature history and deformation of the workpieces during the USW process, especially for the materials with some special properties. In this study, a three-dimensional (3D) finite element analysis model for USW of superelastic NiTi shape memory alloy (SMA) with Cu interlayer was developed using ANSYS Workbench. The thermal-stress coupled phenomena including the heat generation and stress distribution during the welding process was simulated and analyzed. Firstly, the superelastic constitutive model of NiTi SMAs was constructed. The distribution of temperature and stress field was then obtained by thermal-stress analysis using the direct coupling method, and the superelasticity of SMAs was observed. The simulation results showed that the highest temperature occurred in the center of the welding area during USW, which is proportional to the welding time and inversely proportional to the clamping pressure. In addition, the maximum stress occurred at the center of the contact surface between upper NiTi and Cu interlayer. After that, the validity of the simulation results was verified by setting up a thermocouple temperature measurement platform to collect the temperature data, which exhibited a good agreement with the simulated results. The simulation procedure demonstrates its potential to predict temperature and stress distribution during USW process.