Impact of the introduction of commercial purse- seine operations on the traditional fisheries of the Karnataka coast in India

It was during 1977 that large -scale operation of purse – seines started in India mostly along the Karnataka coast. No doubt this has substantially increased the marine fish landings , especially mackerel and sardines . But it has affected the traditional Rampani fishing which also exploits the same fishery resources . The paper makes an impact analysis of this development

Trends in the yield of exploited sciaenid fishery resources along the Indian coasts

In the present account a descriptive analysis is made on the recent trends in the yield of exploited sciaenid fishery resources along the coasts of India during the period, 1966-'84. The all-India state wise catch trends in the order of abundance during the period, 1966-'82 are summarized

Optimal stability for trapezoidal-backward difference split-steps

The marginal stability of the trapezoidal method makes it dangerous to use for highly non-linear oscillations. Damping is provided by backward differences. The split-step combination (αΔt trapezoidal, (1 – α)Δt for BDF2) retains second-order accuracy. The ‘magic choice’ a = 2 – √2 allows the same Jacobian for both steps, when Newton's method solves these implicit difference equations. That choice is known to give the smallest error constant, and we prove that a = 2 – √2 also gives the largest region of linearized stability

Gestational trophoblastic disease in hospital USM : a retrospective review

Introduction- Gestational trophoblastic disease (GTD) forms a group of disorders spanning the conditions of complete and partial molar pregnancies through to the malignant conditions of invasive mole, choriocarcinoma and the very rare placental site trophoblastic tumour (PSIT). The World Health Organization classification divides Trophoblastic Disease into the Pre malignant condition which is Partial Hydratirfonn moles, Complete hydatidiform moles and malignant condition such as Persistant Trophoblastic Disease, Invasive Mole, Choriocarcinoma, Placental Site Tumours. Molar pregnancies can be subdivided into complete (CM) and partial moles (PM) based on genetic and histopathological features. GTD is a rare event in the Europe, with a calculated incidence of 1/714 live births. Objectives- To deteimine prevalence of different types of Gestational Trophoblastic diseases, assess the associated factors of malignant condition compared to pre malignant condition and to determine the outcome of the chemotherapy treatment for patient with GTD. Methodology - A retrospective review was conducted on all GTD cases over the 10 year period between January 2002 and December 2011. The diagnosis and staging was classified using FIGO anatomical staging (Appendix A) and had histopathological confirmation of the disease, data was compiled through a clinical research form for analysis and data analysis was carried out with SPSS version 22. Results - Total of 123 cases were diagnosed with GTD within ten years span, there were 98 cases of Benign form GTD and 25 cases of malignant form ofGTD. Among the benign form of GTD there were 53(43.1%) patients with partial hydatidiform mole and 45(36.6%) with complete hydatidiform mole diagnosed clinically and conformed by histopathological evaluation. Malignant form of GTD accounted for total of 25(20.3%) patients, among which persistant trophoblastic disease (PTD) consist of 22 patients (17.9%) and 3(2.4%) patients with choriocarcinoma Among the associated factors of malignant disease studied was age, ethnicity, pre treatment hCG level, parity, child birth spacing, size of the uterus, size of molar tissue, history of molar pregnancy, previous usage of oral contraceptive pills and presence of thecal luthean cyst. Among the risk factors, age was strongly associated with malignant GTD, it was noted that with increase in every year of age the odds of developing malignant GTD was increased by 5%, The outcome of two major treatment group namely MTX regimen and EMACO regimen was studied, total of 22 patients received MTX as a single agent therapy, all of them were diagnosed with PTD and 19 patients had FIGO stage I disease and one patient with FIGO stage II disease and each one patients in stage III and stage IV disease, the patients in stage II and Ill needed second line chemotherapy with Actinomycin D and achieved full recovery, 19 patients in stage I received single agent MTX and complete recovery was achieved in 12 patients resulting in a success rate of 63% when used a single agent in stage I disease. There were 7 patients with stage I disease who failed to achieve satisfactory response with MTX alone and eventually requiring Actinomycin D (37%) achieved complete recovery from the disease. In this study 3 patients received EMA-CO regime as treatment, all of them were diagnosed with choriocarcinoma, two patients had stage I disease. One of them had hysterectomydone prior to treatment with EMA-CO and another received only EMA-CO after evacuation. Another one patient had stage IV disease with brain and liver metastasis, she was primarily started on EMA-CO and eventually succumbed to death. The remaining 2 patient had complete remission after treatment with EMA-CO, The success rate of EMA-CO in high risk patients at our center remains good as seen in previous studies. Conclusion - In this study the was no major changes in term of the epidemiology of the disease, it was well within the generally accepted prevalence for GTD. Perhaps the one of the most interesting finding in this study was the associated risk factors to develop malignant disease, in this study factors which had high association were age, high parity, and long interval of last child birth. Most patients had FIGO stage I disease, the response to single agent MTX treatment achieved an acceptable outcome, while the rest of the patients who received second line therapy also had a complete recovery. Patients who were in stage II and III had complete recovery with EMA-CO regime.MTX remains as our frrst line treatment in low risk patients while the usage of Actinomycin also proved beneficial in cases of resistant. For the patients in high risk category this study supports the use of EMA-CO

Proceedings of the workshop on acquisition and dissemination of data on marine living resources of Indian seas

In the workshop on acquisition and dissemination of data on marine living resources of Indian seas different sessions were carried out and these were, Present status of marine living resources statistics in India, Identification of data requirements of user sectors and standardisation of suitable proformae for collection of data, Operation of large vessels in the Exclusive Economic Zone, Processing and dissemination of data on marine living resources of indian sea

The mud bank prawn fishery of Kerala - Declining trend

The mud bank fishery, locally known as chaakara fishery is a unique phenomenon along the Kerala coast during the south-west monsoon period. The duration and the location of the fishery show slight variations from year to year. During the rainy season concentrations of mud occur in different areas very close to the shore, providing much calmer seas for operations of fishing boats in comparison to the stormy surf of the monsoon seas of the surrounding localities.In the years in which the fishery fails the condition of the entire population of fishermen who depend on and look forward to this fishery is deplorable.In view of the habits of these prawns of utilising the adjoining estuaries and backwaters of the area as their nursery grounds to a large extent, the increasing amount of exploitation of their young ones in the fishery in the inside waters may probably be one of the reason for the failure of the prawn fishery in the inshore and mud bank areas

Portfolio optimization of credit risky bonds: a semi-Markov process approach

Abstract This article presents a semi-Markov process based approach to optimally select a portfolio consisting of credit risky bonds. The criteria to optimize the credit portfolio is based on l ∞ -norm risk measure and the proposed optimization model is formulated as a linear programming problem. The input parameters to the optimization model are rate of returns of bonds which are obtained using credit ratings assuming that credit ratings of bonds follow a semi-Markov process. Modeling credit ratings by semi-Markov processes has several advantages over Markov chain models, i.e., it addresses the ageing effect present in the credit rating dynamics. The transition probability matrices generated by semi-Markov process and initial credit ratings are used to generate rate of returns of bonds. The empirical performance of the proposed model is analyzed using the real data. Further, comparison of the proposed approach with the Markov chain approach is performed by obtaining the efficient frontiers for the two models

List of titles Marine Fisheries Information Service, Technical and Extension Series No.1-50

Marine Fisheries Information Service, Technical and Extension Series No.1-5

Fluid Queue Driven by Finite State Markov Processes Cola de un fluido modulada por un proceso de Markov con finitos estados

Abstract Steady state distribution of the buffer content of a fluid queue modulated by two independent birth and death processes is found using differential equation techniques to solve a system of equations. The inflow rates are determined by a birth and death process with finite state space and the outflow rate from the buffer is determined by the current state of another independent birth and death process with four states, evolving in the background. Combining these two birth and death processes a continuous time Markov chain is obtained. The steady state buffer content distribution for this fluid queue driven driven by a continuous time Markov chain is thus obtained. Finally, we present numerical results to illustrate the feasibility of the proposed model. Resumen La distribución del estado estacionario del contenido de una cola de fluido en un dispositivo modulado por dos procesos independientes de nacimiento y muerte, se encuentra utilizando técnicas diferenciales para resolver un sistema de ecuaciones. Las tasas de flujo de entrada se determinan mediante un proceso de nacimiento y muerte, con espacio de estados finitos y la tasa de flujo de salida del recipiente se determina por el estado actual de otro proceso independiente de nacimiento y muerte con cuatro estados, que evolucionan en el fondo. Mediante la combinación de estos dos procesos de nacimiento y muerte se obtiene una cadena de Markov de tiempo continuo. Se observa que la distribución del estado estacionario del contenido de una cola de fluido se modula por una cadena de Markov en tiempo continuo. Finalmente, se presentan resultados numéricos para ilustrar la viabilidad del modelo propuesto. Palabras clave: Cadena de Markov de tiempo continuo, Distribución de estados estacionarios, Procesos de nacimiento y muerte