1,634 research outputs found

    In situ observation of scorpionfish in seagrass meadows of the Gulf of Mannar, India

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    The seagrass meadows of Sethukarai coast are unique in nature, housing high faunal diversity compared to other coastal areas. A rare live specimen of bandtail scorpionfish Scorpaenopsis neglecta was found near a burrow dug by an alpheid shrimp. Taxonomy, morphometric and meristic characters, adaptive, behavioural and colour-switching physiological camouflage trait of the S. neglecta are elaborated in this communication. Visual in situ documentation of feeding habits of scorpaenids and their preying behaviour, especially that of lionfish Pterois volitans preying on goby fish is presented. Mutualism exhibited by goby fish Amblyeleotris gymnocephala with the alpheid shrimp Alpheus rapax and the importance of habitat protection from anthropogenic activities are also discussed

    Occurrence and Abundance of Phosphatase-Producing Bacteria in Mangrove Ecosystem

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    The study detailed the isolation and characterization of phosphatase producing bacteria (PPB) from rhizospheric, pneumatophoric and bulk sediments of Avicennia marina along Mumbai coast, India and also estimated alkaline phosphatase activity in sediment in addition to the Phosphatase enzymatic activity of isolates. The inorganic-organic nature of phosphorus was also examined. About, 42 PPB were isolated and identified from the sediment samples. 16S rDNA sequence revealed that all the isolates belong to the genus Bacillus except the one which belong to Geobacillus in the environment and B. anthracis str. Ames showed the phosphatase-producing activity of 84.11±0.01 µg p-NP released per 1×108 cfu in 72 hrs. The isolates, B. cereus strain APT23 and B. thuringiensis strain INRS4 showed the next best phosphatase activity. It was observed that PPB was very much abundant in A. marina mangroves. The pneumatophoric sediment showed significantly higher number of PPB with higher alkaline phosphatase activity, inorganic P and low organic P than those of other sediment types indicating that pneumatophoric region of A. marina harbours favourably the phosphatase-producers than the rhizospheric or bulk sediments and forms the first reference worldwide depicting this relationship. The isolates that showed higher phosphatase-producing potentials can be explored for using as phosphatic bio-fertilizer to enhance the agricultural, aquacultural and mangrove productivity on a larger scale

    Nonlocal de Broglie Wavelength of a Two-Photon System

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    Abstract We show that it is possible to associate a de Broglie wavelength to a composite system even when the constituent particles are separated spatially. The nonlocal de Broglie wavelength (A /2) of a two-photon system separated spatially is measured with an appropriate detection system. The two-photon system is prepared in an entangled state in space-momentum variables. - Pacs: 42.50.-p, 42.50.A

    Influence of the number of trials and the exercise to rest ratio in repeated sprint ability, with changes of direction and orientation

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    The purpose of this investigation was to determine if there were different trends in physical fatigue observed in 3 different sets, of 7 trials each, in repeated sprint training, performed in 3 different modes: straight sprinting over 30 m, shuttle sprinting over 15 + 15 m, and sprinting over 30 m with changes of direction. Recovery time among trials in the sets was administered according to the 1:5 exercise to rest ratio. The sets were performed on 3 different days, with at least 48 hours between each set. The study involved 17 trained male soccer players (height, 177.33 +/- 6.21 cm; body mass, 71.63 +/- 9.58 kg; body mass index, 23 +/- 2.39 kg<bold>m(</bold>-2); age, 21.94 +/- 3.58 years). To compare the different values of the time recorded, an index of fatigue was used. Significant differences among trials within each set (repeated measures analysis of variance; p < 0.05) and between the sets (factorial analysis of variance; p < 0.001) were found. Significant correlations between each test and countermovement jump and stiffness values recorded pre exercise were found (p < 0.05). Significant differences between countermovement jump and stiffness values recorded pre and post exercise were also found (p < 0.05). This study suggests that training sessions aimed at increasing the capacity of repeated sprint ability in nonlinear and multidirectional sprints (shuttle and change of direction), which might imply a different number of trials within the set or different exercise to rest ratios from the ones usually adopted for straight sprinting, to induce similar trends of fatigue. As practical applications, the estimated numbers of necessary trials in the different sets and the possible exercise to rest ratios, resulting from mathematical modeling, are provided for each investigated sprinting mode

    Idealização do Masculino e do Feminino a Partir dos Processos de Crimes Passionais na Cidade de Vitória (1890-1930)

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    Este trabalho é o resultado de uma investigação do processo histórico sobre o masculino e o feminino, na cidade de Vitória e entorno, durante a Primeira República Brasileira (1890-1930), no Estado do Espírito Santo. Foram analisadas as idealizações dos papéis sociais do homem e da mulher, por meio de processos judiciais de crimes passionais, contemplando-se entendimentos de juízes, depoimentos de envolvidos e de testemunhas. Os resultados apontam que a violência de gênero e a sua legitimação têm como importantes contribuintes a natureza da relação de poder e de reafirmação que marcavam a estrutura hierárquica capixaba. A partir de um elenco de princípios considerados positivos e negativos, desenharam-se representações sociais de condutas aceitáveis e nãoaceitáveis que orientavam as práticas sociais dos sujeitos. A Justiça, em alguns processos, apresentou-se imparcial, relativizando a sua conduta quando de sentenças que poderiam ferir valores considerados cruciais ao tempo. Por fim, buscou-se contribuir ao resgate da história local, contextualizando-a no âmbito da nacional; destacando-se a importância da cidade de Vitória como núcleo político, econômico e cultural do Estado

    Generalised Hong-Ou-Mandel Experiments with Bosons and Fermions

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    The Hong-Ou-Mandel (HOM) dip plays an important role in recent linear optics experiments. It is crucial for quantum computing with photons and can be used to characterise the quality of single photon sources and linear optics setups. In this paper, we consider generalised HOM experiments with NN bosons or fermions passing simultaneously through a symmetric Bell multiport beam splitter. It is shown that for even numbers of bosons, the HOM dip occurs naturally in the coincidence detection in the output ports. In contrast, fermions always leave the setup separately exhibiting perfect coincidence detection. Our results can be used to verify or employ the quantum statistics of particles experimentally.Comment: 11 pages, 2 figures, more references adde

    CMFRI Marine Fisheries Policy Series No.15; Fishery Management Plan for Palk Bay Blue Swimming Crab

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    Crabs are widely distributed in Indian seas and form minor fishery at various regions along the east and west coasts. Crabs contribute a share of 11.1 % in total crustacean landings, with an approximate production of 53476 tonnes in 2017. Three portunid crabs, Portunus pelagicus, Portunus sanguinolentus and Charybdis feriatus form the majority of the regular crab landings in India. The demand for Portunus pelagicus, commonly known as Blue Swimming Crab (BSC) is consistently increasing ever since its export started in the beginning of the century. The State of Tamil Nadu is leading in marine crab landings particularly for the blue swimming crab production in India. The major landing centres for BSC are located in the Palk Bay (PB) and Gulf of Mannar (GoM) areas of Ramanathapuram, Pudukkottai and Thanjavur districts of the state. BSC products form the most important internationally traded commodity from the region and contribute significantly to the livelihood of crab merchants and crab fishers of the area. The Central Marine Fisheries Research Institute has been monitoring the BSC fishery and studying the biology the species along with other marine resources. During the last decade of the 20th century more focused and in-depth studies have been conducted on Portunus pelagicus and established the fact that apart from its fisheries importance, BSC is also a suitable candidate species for farming. This document gives insights on BSC fishing zones, major fishing craft and gears, area wise and centre wise production details, trade, processing industry and export markets. Furthermore, it elucidates the complete life cycle of the species including its growth and reproductive biology as these form essential and integral inputs while formulating the management decisions. As BSC is a highly valuable commodity it necessitates urgent attention to its responsible exploitation and action plan for the judicious management of the resource to accomplish BSC as a sustained fishery. Conclusions have drawn based on the facts and evidences, acquired from exhaustive field and laboratory studies and guidance on a Fishery Management Plan for Palk Bay BSC fishery are presented
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