A summary of zooplankton research done in Peruvian marine waters is presented. We first provide a brief overview of the evolution of zooplankton studies off Peru before reviewing zooplankton biodiversity, regional distribution, seasonal and interannual fluctuation, trophodynamics, secondary production, and modeling are some of these topics. We evaluate research on various meroplankton, macroplankton, mesoplankton, and microplankton groups and provide a list of species from both published and unpublished sources. Three regional zooplankton groups have been identified: A shelf group on the continental shelf dominated by Acartia tonsa and Centropages brachiatus; A slope group on the continental shelf with siphonophores, bivalves, foraminifera, and radiolaria An oceanic group with adiversity of species. Where the continental shelves are thin, between 4-6°S and 14-16°S, the largest zooplankton abundances and biomasses were frequently seen. The diversity of species varies according to distance from the shore. As a result of advection, peaks in larval production, trophic interactions, and community succession, species composition and biomass also change significantly over short time intervals. Based on the detrimental consequences of weak summer upwelling intensity or exceptionally high and persistent winter upwelling on zooplankton abundance off Peru, an intermediate upwelling hypothesis is put forth. This concept states that a window of optimal environmental conditions for zooplankton groups is produced by intermediate upwelling. Finally, we identify significant knowledge gaps that demand future attention
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In this research, the focus was on estimating the parameters on (min- Gumbel distribution), using the maximum likelihood method and the Bayes method. The genetic algorithmmethod was employed in estimating the parameters of the maximum likelihood method as well as the Bayes method. The comparison was made using the mean error squares (MSE), where the best estimator is the one who has the least mean squared error. It was noted that the best estimator was (BLG_GE).
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This paper aims to decide the best parameter estimation methods for the parameters of the Gumbel type-I distribution under the type-II censorship scheme. For this purpose, classical and Bayesian parameter estimation procedures are considered. The maximum likelihood estimators are used for the classical parameter estimation procedure. The asymptotic distributions of these estimators are also derived. It is not possible to obtain explicit solutions of Bayesian estimators. Therefore, Markov Chain Monte Carlo, and Lindley techniques are taken into account to estimate the unknown parameters. In Bayesian analysis, it is very important to determine an appropriate combination of a prior distribution and a loss function. Therefore, two different
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The optimization calculations are made to find the optimum properties of combined quadrupole lens consist of electrostatic and magnetic lenses to produce achromatic lens. The modified bell-shaped model is used and the calculation is made by solving the equation of motion and finding the transfer matrices in convergence and divergence planes, these matrices are used to find the properties of lens as the magnification and aberrations coefficients. To find the optimum values of chromatic and spherical aberrations coefficients, the effect of both the excitation parameter of the lens (n) and the effective length of the lens into account as effective parameters in the optimization processing
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The study targets exploring the similarities and differences between Iraqi and Malaysian learners of English in refusing marriage proposals. Also, it examines the favored politeness strategies that learners use to protect their interlocutors’ face, heeding both their social distance and status. Data were gathered by a Discourse Completion Task (DCT) which contained six marriage situations. Responses were analyzed based on Beebe et al.’s (1990) refusal taxonomy and Scollon et al.’s (2012) politeness system. The findings indicated that both the Iraqi and Malaysian learners preferred the indirect refusal strategies in marriage proposals, as well as the hierarchical politeness in the form of independence strategies regardless of t
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The study targets exploring the similarities and differences between Iraqi and Malaysian learners of English in refusing marriage proposals. Also, it examines the favored politeness strategies that learners use to protect their interlocutors’ face, heeding both their social distance and status. Data were gathered by a Discourse Completion Task (DCT) which contained six marriage situations. Responses were analyzed based on Beebe et al.’s (1990) refusal taxonomy and Scollon et al.’s (2012) politeness system. The findings indicated that both the Iraqi and Malaysian learners preferred the indirect refusal strategies in marriage proposals, as well as the hierarchical politeness in the form of independence strategies regardless of t
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The current research (violence in contemporary Iraqi drawing) study the nature of the manifestations of violence, Kdoual effective in technical text and give these functions of the images have multiple connotations psychological symbolism, and has read the text in the light of the impact of the Iraqi social reality after the recent occupation of events and to study the impact of this stage on Iraqi contemporary painting, and this research consists of three chapters included the first chapter defines the research problem, which is illustrated through the following questions which are real problems require study and research .
Is constitute an objective treatment of the Academy of artistic representations of a phenomenon in the for
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