Preliminary characterisation of gonad inhibiting hormone (GIH) gene and its expression pattern during vitellogenesis in giant tiger shrimp, Penaeus monodon Fabricius, 1798

Farming of giant tiger shrimp is one of the most important and relatively recent coastal food production sectors in India. Although great strides have been made in shrimp husbandry practices in growout systems, management of reproduction in captivity has not kept pace. Although several hormones are involved in crustacean reproduction, the inhibitory effect of gonad inhibiting hormone (GIH) is thought to be more intense than any other hormones. As an essential component of understanding the reproduction of Penaeus monodon, we characterised the expression pattern of GIH gene in the sinus gland in relation to the female gametogenic cycle. A 633 bp sequence was cloned from the eyestalk of P. monodon by RT PCR. The sequence comprises an open reading frame (ORF) of 291 bp that encodes a protein of 96 amino acids. The deduced protein was used to search the GenBank database using BlastP. Protein alignment with all known crustacean GIH revealed that homology of P. monodon GIH shares 61, 48, 46, 46 and 35% identity with Metapenaeus ensis, Nephrops norvegicus, Homarus americanus, Rimicaris kairei and Armadillidium vulgarae respectively. The RT PCR analysis shows that GIH mRNA is expressed mainly in the eyestalk of female. In order to find the expression profile of GIH during different reproductive cycle, P. monodon female was categorised into four major stages of maturation, using light microscopical observations as well as morphological characteristics. Eyestalk of all animals from different stages of maturation indicated that GIH is expressed in all stages of maturation, although the expression of GIH mRNA changes during different stages of vitellogenesis. In animals with immature ovary, the relative GIH mRNA level was found to be less, which peaked in previtellogenic phase and diminished in subsequent phases. Low GIH mRNA level during the immature (oogonial) phase is particularly intriguing and has application in the commercial aquaculture to select the brooder

DNA sequence information resolves taxonomic ambiguity of the common mud crab species (Genus Scylla) in Indian waters

For several years, mud crabs of genus Scylla have been misidentified owing to their high morphological plasticity and the absence of distinct morphological diagnostic characters. The taxonomic confusion of genus Scylla de Haan is considered to be a primary constraint to the development of aquaculture. Although genus Scylla was revised using morphological and genetic characteristics, taxonomy of Scylla species occurring in India is still not clear. In this study, partial sequences of two mitochondrial genes, 16S rRNA and CO1 (Cytochrome C oxidase subunit I) in populations of Scylla spp. obtained from eleven locations along the Indian coast were used to differentiate and resolve taxonomical ambiguity of the mud crab species in India. The sequences were compared with previously published sequences of Scylla spp. Both trees generated based on 16S rRNA and CO1 indicated that all S. tranquebarica morphotypes obtained during this study and S. tranquebarica sequences submitted previously from Indian waters reciprocally monophyletic with reference sequence of S. serrata. Both sequence data and morphological characters revealed that the species S. serrata (Forskal) is the most abundant followed by S. olivacea. Further, the 16S rRNA and COI haplotypes of Indian S. tranquebarica obtained in the study significantly differed with the known S. tranquebarica by 6.7% and 10.6% respectively whereas it differed with known S. serrata by 0.0–0.7% only, a difference that was not statistically significant. From these studies it is clear that ‘‘S. tranquebarica’’ commonly reported from India should be S. serrata (Forskal)

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Not AvailableFarming of giant tiger shrimp is one of the most important and relatively recent coastal food production sectors in India. Although great strides have been made in shrimp husbandry practices in growout systems, management of reproduction in captivity has not kept pace. Although several hormones are involved in crustacean reproduction, the inhibitory effect of gonad inhibiting hormone (GIH) is thought to be more intense than any other hormones. As an essential component of understanding the reproduction of Penaeus monodon, we characterised the expression pattern of GIH gene in the sinus gland in relation to the female gametogenic cycle. A 633 bp sequence was cloned from the eyestalk of P. monodon by RT PCR. The sequence comprises an open reading frame (ORF) of 291 bp that encodes a protein of 96 amino acids. The deduced protein was used to search the GenBank database using BlastP. Protein alignment with all known crustacean GIH revealed that homology of P. monodon GIH shares 61, 48, 46, 46 and 35% identity with Metapenaeus ensis, Nephrops norvegicus, Homarus americanus, Rimicaris kairei and Armadillidium vulgarae respectively. The RT PCR analysis shows that GIH mRNA is expressed mainly in the eyestalk of female. In order to find the expression profile of GIH during different reproductive cycle, P. monodon female was categorised into four major stages of maturation, using light microscopical observations as well as morphological characteristics. Eyestalk of all animals from different stages of maturation indicated that GIH is expressed in all stages of maturation, although the expression of GIH mRNA changes during different stages of vitellogenesis. In animals with immature ovary, the relative GIH mRNA level was found to be less, which peaked in previtellogenic phase and diminished in subsequent phases. Low GIH mRNA level during the immature (oogonial) phase is particularly intriguing and has application in the commercial aquaculture to select the brooders.Not Availabl

Factors associated with poor prognosis in very-low-birth-weight infants

This article reports on an evaluation of the predictors of poor outcome for low birthweight children including the CRIB score, based on children born beteen 1 September 1992 and 1 September 1994

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Not AvailableFarming of giant tiger shrimp is one of the most important and relatively recent coastal food production sectors in India. Although great strides have been made in shrimp husbandry practices in growout systems, management of reproduction in captivity has not kept pace. Although several hormones are involved in crustacean reproduction, the inhibitory effect of gonad inhibiting hormone (GIH) is thought to be more intense than any other hormones. As an essential component of understanding the reproduction of Penaeus monodon, we characterised the expression pattern of GIH gene in the sinus gland in relation to the female gametogenic cycle. A 633 bp sequence was cloned from the eyestalk of P. monodon by RT PCR. The sequence comprises an open reading frame (ORF) of 291 bp that encodes a protein of 96 amino acids. The deduced protein was used to search the GenBank database using BlastP. Protein alignment with all known crustacean GIH revealed that homology of P. monodon GIH shares 61, 48, 46, 46 and 35% identity with Metapenaeus ensis, Nephrops norvegicus, Homarus americanus, Rimicaris kairei and Armadillidium vulgarae respectively. The RT PCR analysis shows that GIH mRNA is expressed mainly in the eyestalk of female. In order to find the expression profile of GIH during different reproductive cycle, P. monodon female was categorised into four major stages of maturation, using light microscopical observations as well as morphological characteristics. Eyestalk of all animals from different stages of maturation indicated that GIH is expressed in all stages of maturation, although the expression of GIH mRNA changes during different stages of vitellogenesis. In animals with immature ovary, the relative GIH mRNA level was found to be less, which peaked in previtellogenic phase and diminished in subsequent phases. Low GIH mRNA level during the immature (oogonial) phase is particularly intriguing and has application in the commercial aquaculture to select the broodersNot Availabl

Factors associated with poor prognosis in very-lowbirth- weight infants

Objective: To evaluate predictors of poor outcome, including the CRIB (Clinical Risk Index for Babies) score, in a local population of very-low-birth-weight (VLBW) infants, in order to provide guidelines for selection of these babies for expensive tertiary care. Subjects: Two hundred and thirty-one neonates bom at less than 31 weeks' gestation and/or weighing between 1 001 g and 1 500 g, enrolled prospectively as part of a multicentre study evaluating the CRIB score. Design: Univariate analysis (chi-square/t-tests) and muttivariate analysis (stepwise logistic regression) on the above sample to detennine predictors of poor outcome. Setting: NeonataJ Unit, Johannesburg Hospital. Outcome measures: Death or impainnent (namely oxygen therapy> 28 days, grade 3 or 4 intraventricular haemorrhage, or ventricular enlargement). Results: Poor outcome was predicted by birth weight, lowest oxygen requirement in the first 12 hours (which are two components of the CRIB score), and maximum partial arterial carbon dioxide pressure (PaCO2) in the first 72 hours. Other factors, including the full CRIB score, were not predictive of outcome. Conclusions: One method of selection of infants for expensive tertiary care is on the basis of predicted outcome. Birth weight remains a reasonable basis for this selection, but the inclusion of other factors, such as oxygen requirement, would improve accuracy. The CRIB score was not a suitable means to select infants in the local context, but may be of value in international comparisons.S Afr Med J 1996; 86: 1457-146

Phase transformation and residual stress analysis in cryo-treated single point cutting tool

95-102<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">A finite element method is carried out to compute temperature, phase transformation and residual stress distribution for a single point high speed steel tool. Thermophysical and mechanical properties are taken as a function of temperature. The residual stresses formed due to quenching are calculated using thermo-elastic-plastic approach. The cryo-treatment of a high speed steel tool at 173K gives about 16% higher martensite as compared to oil quenching. The residual stresses induced in the case of cryo-treatment are higher as compared to oil quenching at 300K. Experiments were done to determine the Rockwell hardness number and microstructure of the HSS T1 type tool before and after the cryo-treatment. The results show improvement in hardness and increase in martensite transformation.</span

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Not AvailableReproduction is a main area where science can contribute to the growth of aquaculture and provide effective solutions for industry problems. Thus, many research projects have focused on the reproductive biology of farmed species. However, most researchers focused on female reproduction – possibly due to the obvious reproductive dysfunction of females under captivity. In female shrimp, vitellogenesis and oocyte maturation are processes that demand high levels of energy. Conversely, in males, sperm production is believed to consume less energy. Males use up more energy for sex competition and female guarding. Yet male-related reproductive dysfunction and infertility have been increasingly reported in commercial The authors recently carried out a series of studies at the experimental shrimp hatchery facility of the Central phore regeneration in black tiger shrimp Institute of Brackishwater Aquaculture to characterize the reproductive capability of male black tiger shrimp, Penaeus monodon, by documenting changes in sperm quality in relation to consecutive regeneration, molting cycle and length of rearing period.Not Availabl