К вопросу о табулировании функций распределения отказов

Проведена перепараметризация основных строго вероятностных функций распределения отказов: экспоненциального распределения, логарифмически нормального распределения и распределения Вейбулла. Разработаны таблицы функций распределения отказов и примеры их использования для решения некоторых задач по надежности.Проведено перепараметризацію основних строго ймовірнісних функцій розподілів відмов: експоненційного розподілу, логарифмічно нормального розподілу, розподілу Вейбулла. Розроблено таблиці функцій розподілів відмов та приклади їх використання для рішення деяких задач з надійності.The reparametrization of the basic strictly probabilistic functions of refusals distribution: exponential distributions, logarithmically normal distribution and distribution Weibull are carried out. Tables of refusals distribution functions and examples of their use for the decision of some tasks on reliability are developed

Weak population structure and recent demographic expansion of the monogenean parasite Kapentagyrus spp. infecting clupeid fishes of Lake Tanganyika, East Africa

Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Elsevier in International Journal for Parasitology on 08/04/2020.Available online: https://www.sciencedirect.com/science/article/pii/S0020751920300606?via%3DihubLake Tanganyika, East Africa, is the oldest and deepest African Great Lake and harbours one of the most diverse fish assemblages on earth. Two clupeid fishes, Limnothrissa miodon and Stolothrissa tanganicae, constitute a major part of the total fish catch, making them indispensable for local food security. Parasites have been proposed as indicators of stock structure in highly mobile pelagic hosts. We examined the monogeneans Kapentagyrus limnotrissae and Kapentagyrus tanganicanus (Dactylogyridae) infecting these clupeids to explore the parasites’ lake-wide population structure and patterns of demographic history. Samples were collected at seven sites distributed across three sub-basins of the lake. Intraspecific morphological variation of the monogeneans (n = 380) was analysed using morphometrics and geomorphometrics of sclerotised structures. Genetic population structure of both parasite species (n = 246) was assessed based on a 415 bp fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Overall, we observed a lack of clear geographical morphological differentiation in both parasites along a north–south axis. This lack of geographical population structure was also reflected by a large proportion of shared haplotypes, and a pattern of seemingly unrestricted gene flow between populations. Significant morphological and genetic differentiation between some populations might reflect temporal differentiation rather than geographical isolation. Overall, the shallow population structure of both species of Kapentagyrus reflects the near-panmictic population structure of both host species as previously reported. Morphological differences related to host species identity of K. tanganicanus were consistent with incipient speciation at the genetic level. Both parasite species experienced a recent demographic expansion, which might be linked to paleohydrological events. Finally, interspecific hybridisation was found in Kapentagyrus, representing the first case in dactylogyrid monogeneans.acceptedVersio

Weak population structure and expansive demographic history of the monogenean parasite Kapentagyrus spp. infecting clupeid fishes of Lake Tanganyika

status: accepte

Local perceptions on the state of the pelagic fisheries and fisheries management in Uvira, Lake Tanganyika, DR Congo

The fisheries of Lake Tanganyika play an important role in food security in Central and Eastern Africa. Conservation of these valuable fish stocks will benefit from documenting the ideas, opinions and observations of stakeholders. Knowledge of the perceptions and an understanding of the concerns and struggles of stakeholders of these fisheries can provide policy-makers with recommendations for more suitable fisheries management. We did 1018 interviews with stakeholders, in one close-ended and three semi-open ended surveys. Factor analysis revealed seven clusters of opinions. Linear-mixed effects models identified common grounds and differences in opinions between groups of stakeholders about strategies in fisheries management. Stakeholders of the fisheries indicated challenges due to weather or climate variability, a noticeable decrease in fish abundance and size, and an increase in the price of fish. Fishermen experienced a lack of safety on the lake, including aggression and dangerous weather conditions, and hardly had access to safety gear and infrastructure. Landing site officials, state employees who monitor the beaches, mentioned capture of juveniles and declining catch-rates as the biggest threats to the fisheries. None of the groups of stakeholders attributed the problems in the fisheries to overfishing or overpopulation. We found similarities in opinions over a wide range of stakeholder groups, with many stakeholders asking for better and fair enforcement of existing legislation. State employees were more positive than the other groups towards creating more strict regulation of the fisheries. The results presented offer focuspoints for policy-makers to improve the management of the Lake Tanganyika pelagic fisheries