Modulation of testicular lutropin receptors in the developing male rat

In the developing male rat around 40 days of age, the testis appears to contain the maximum amount of lutropin receptors per unit weight. During this period, circulating levels of testosterone markedly increase without the concomitant major surges in lutropin levels. The increased sensitivity and responsiveness of tests to basal levels of circulating lutropin during this period is accompanied by enhanced serum prolactin levels suggesting that this hormone may be involved in this process. The finding that prolactin treatment of pubertal rats for 3 days induced the formation of more testicular lutropin receptors supports the above premise. However, shortterm immunoneutralisation of endogenous prolactin did not significantly alter the specific binding of [125I]-labelled lutropin to testicular membranes. Interestingly, during development, a close correction exists between receptor occupancy and capacity of the tissue to bind labelled lutropin. The apparent dissociation between serum lutropin levels, on the one hand and tissue occupancy and free receptor contents on the other, suggests that factors other than lutropin (presumably prolactin) are involved in the modulation of the sensitivity and the responsiveness of the testis to lutropin during early development

Isolation of sheep anterior pituitary messenger RNA and its translation in a heterologous cell-free system

A preparation rich in the specific messenger RNA involved in the synthesis of prolactin from sheep anterior pituitary glands was obtained by employing both the immunochemical and affinity techniques. A dose-dependent and efficient stimulation of protein synthesis by the isolated total pituitary RNA as well as poly (A) rich RNA were achieved with the reticulocyte system. The synthesis of prolactin as one of the translational products of this cell-free system was established by specific immunoprecipitation followed by resolution on sodium dodecyl sulphate polyacrylamide gel electrophoresis

Testing embedded system through optimal mining technique (OMT) based on multi-input domain

Testing embedded systems must be done carefully particularly in the significant regions of the embedded systems. Inputs from an embedded system can happen in multiple order and many relationships can exist among the input sequences. Consideration of the sequences and the relationships among the sequences is one of the most important considerations that must be tested to find the expected behavior of the embedded systems. On the other hand combinatorial approaches help determining fewer test cases that are quite enough to test the embedded systems exhaustively. In this paper, an Optimal Mining Technique that considers multi-input domain which is based on built-in combinatorial approaches has been presented. The method exploits multi-input sequences and the relationships that exist among multi-input vectors. The technique has been used for testing an embedded system that monitors and controls the temperature within the Nuclear reactors

Oxidation mechanism in metal nanoclusters: Zn nanoclusters to ZnO hollow nanoclusters

Zn nanoclusters (NCs) are deposited by Low-energy cluster beam deposition technique. The mechanism of oxidation is studied by analysing their compositional and morphological evolution over a long span of time (three years) due to exposure to ambient atmosphere. It is concluded that the mechanism proceeds in two steps. In the first step, the shell of ZnO forms over Zn NCs rapidly up to certain limiting thickness: with in few days -- depending upon the size -- Zn NCs are converted to Zn-ZnO (core-shell), Zn-void-ZnO, or hollow ZnO type NCs. Bigger than ~15 nm become Zn-ZnO (core-shell) type: among them, NCs above ~25 nm could able to retain their initial geometrical shapes (namely triangular, hexagonal, rectangular and rhombohedral), but ~25 to 15 nm size NCs become irregular or distorted geometrical shapes. NCs between ~15 to 5 nm become Zn-void-ZnO type, and smaller than ~5 nm become ZnO hollow sphere type i.e. ZnO hollow NCs. In the second step, all Zn-void-ZnO and Zn-ZnO (core-shell) structures are converted to hollow ZnO NCs in a slow and gradual process, and the mechanism of conversion proceeds through expansion in size by incorporating ZnO monomers inside the shell. The observed oxidation behaviour of NCs is compared with theory of Cabrera - Mott on low-temperature oxidation of metal.Comment: 9 pages, 8 figure

A Mathematical Model for Micropolar Fluid Flow Through an Artery with the effect of Stenosis and Post Stenotic Dilatation

The effects of both stenosis and post stenotic dilatation have been studied on steady flow of micropolar fluid through an artery. Assuming the stenosis to be mild, the equations governing the flow of the proposed model are solved. Closed form expressions for the flow characteristics such as velocity, pressure drop, and volumetric flow rate, resistance to the flow and wall shear stress are derived. The effects of various parameters on resistance to the flow and wall shear stress have been analyzed through the graphs. It is found that the resistance to the flow increases with the height and length of the stenosis, but the resistance to the flow decreases with stenotic dilatation. With the increase of the coupling number the resistance to the flow increases. However, the effect of coupling number is not very significant. The resistance to the flow decreases with the micropolar fluid parameter. The wall shear stress increases with coupling number and stenosis height, but it decreases with micropolar fluid parameter and stenotic dilatation

Processing map for hot working of alpha-zirconium

The hot deformation characteristics of alpha-zirconium in the temperature range of 650°C to 850°C and in the strain-rate range of 10-3 to 102 s-1 are studied with the help of a power dissipation map developed on the basis of the Dynamic Materials Model. The processing map describes the variation of the efficiency of power dissipation (η=2m/m + 1) calculated on the basis of the strain-rate sensitivity parameter (m), which partitions power dissipation between thermal and microstructural means. The processing map reveals a domain of dynamic recrystallization in the range of 730°C to 850°C and 10-2 to 1-1 with its peak efficiency of 40 pct at 800°C and 0.1 s-1 which may be considered as optimum hot-working parameters. The characteristics of dynamic recrystallization are similar to those of static recrystallization regarding the sigmoidal variation of grain size (or hardness) with temperature, although the dynamic recrystallization temperature is much higher. When deformed at 650°C and 10-3 s-1 texture-induced dynamic recovery occurred, while at strain rates higher than 1 s-1, alpha-zirconium exhibits microstructural instabilities in the form of localized shear bands which are to be avoided in processing

Proper Management of Metallurgical Wastes - A Paramount Necessity for clean Environment

Rapid industrialization has led to substantial decline in the quality of the environment. The long journey from mining of iron ores to the production of finished steel generates a variety of solid, gaseous and liquid wastes in considerable quantities. Some of the wastes have adverse effects that have long-term influence and demand remedies. Therefore, it is essential that proper management of harmful wastes be done on priority basis for maintaining clean environment. This paper discusses in detail the various metallurgical wastes generated in steel plants and their effects on environment. The paper also deals with the necessity of recyling of metallurgical wastes and measures taken by Indian integrated steel plants to save and maintain clean environment in and around the factory premises. Some of the recent clean technologies adopted abroad have been briefly presented