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21.
Treatment of newly born Poecilia sphenops (Cuvier & Valenciennes, 1846) with 50 mg 17α-methyl-testosterone or 200 mg androstenedione per kg diet for 30 days induced a maximum of 59% males; attempts to increase masculinization by increasing dose or treatment duration resulted in higher mortality. The growth of the treated males was significantly (25-53% retarded. Anabolic enhancement of relative growth (percentage of control) of the treated males and females was apparent in juveniles but not in adults. Hormonal induction of masculinization impaired the gonadal development and courtship activity, and led to the production of sterile males and females. 相似文献
22.
Azolla pinnata R. Brown was used as a biofertilizer for rice crop in early and late wet seasons of 1985–86. Azolla as dual crop with rice increased the grain yield significantly over uninoculated control. Incorporation of Azolla increased the yield components and grain yield higher than leaving Azolla on water surface without incorporation. Azolla incorporation with 90 kg nitrogen/ha recorded the highest plant height, tiller numbers/ hill, panicles/m2 and 1000 grain weight and grain yield of rice. 相似文献
23.
Sundaresan NR Marcus Leo MD Subramani J Anish D Sudhagar M Ahmed KA Saxena M Tyagi JS Sastry KV Saxena VK 《Veterinary research communications》2009,33(1):49-56
Melatonin (N-acetyl-5-methoxytryptamine), an indole hormone, regulates various biological functions through three different receptor subtypes
(Mel-1a, Mel-1b, and Mel-1c). However, the distribution of different melatonin receptor subtypes in chicken reproductive tissues
was not known. In the present investigation, the partial sequences of ovarian melatonin receptor subtypes (Mel-1a, Mel-1b,
and Mel-1c) were characterized. Further, the expression profile of melatonin receptor subtypes in the granulosa and theca
layers of different preovulatory and postovulatory follicles (POF) were studied by semi-quantitative RT-PCR. The expression
of all three subtypes of melatonin receptors were observed in the ovary of domestic chicken. Analysis of partial sequences
of ovarian melatonin receptors revealed that the melatonin subtypes were identical to the brain receptors. In small white
ovary follicles, we observed only the expression of mel-1b receptors, but not mel-1a or mel-1c receptors. In yellow follicles,
all the three subtypes of receptors expression were noticed. Interestingly, we observed the expression of mel-1a receptor
only in thecal layer, but not in granulosa layer. In contrast, mel-1b and -1c receptors were expressed in both granulosa and
thecal layer. During the regression of POF, we observed significant upregulation of melatonin receptors (mel-1a and 1c) expression,
that downregulated in the later stages of regression. We assume that the expression of melatonin receptors might have been
influenced by the atresia or apoptosis of different follicular layers in POF. Our findings suggest that the differential distribution
of melatonin receptor subtypes might have distinct downstream cellular functions in the ovarian tissues. 相似文献
24.
B. Vijaya Ramnath S. Rajesh C. Elanchezhian A. Santosh Shankar S. Pithchai Pandian S. Vickneshwaran R. Sundar Rajan 《Fibers and Polymers》2016,17(1):80-87
Nowadays, automotive, packaging and sport equipment industries are using natural fibre based composite materials as they are cheap, abundantly available and having a lot of ecological advantages. The main objective of this paper is to introduce a new concept of fibre twisting and to investigate the effect of twisting and the fibre orientation on the mechanical properties of bio degradable green composites. Here, the composites are fabricated by vacuum assisted compression molding technique in which the problems of hand lay process are eliminated. Here, two fibers namely twisted neem and twisted kenaf are sandwiched between layers of glass fibres to enhance the stiffness and strength of the laminates. Initially, the fibers are alkalized to increase the mechanical properties. The result shows that there is a significant improvement in mechanical properties of composites due to the presence of twisted fibers. It also shows the influence of fiber orientation on mechanical properties. 相似文献