227 research outputs found

    Understanding the dietary relationship between extensive Noctiluca bloom outbreaks and Jellyfish swarms along the eastern Arabian Sea (West coast of India)

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    1389-1394The paper attempts to understand the interrelationship between recurring blooms of dinoflagellate, Noctiluca scintillans as well as increasing jellyfish swarms along the coastal waters of eastern Arabian Sea. The grazing of N. scintillans on diatoms in the productive waters with reduced competition pressure due to the opportunistic feeding of jellyfishes on zooplankton are described here. With the development of N. scintillans in the favourable environmental conditions, jellyfishes utilize this dinoflagellate as their food source and thrive in the coastal waters. Hence, trophic interaction between Noctiluca and jellyfishes leading to their proliferation in the coastal waters are delineated

    Variabilities in the community structure of phytoplankton in the upwelled and non-upwelled waters of southeastern Arabian Sea during the early summer monsoon

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    542-549The community structure of microphytoplankton was assessed along the southeastern Arabian Sea during the early phase of the summer monsoon. The study records an intense coastal upwelling along the southernmost region (off Thiruvananthapuram), which decreased further north. High chlorophyll-a (10.8 mg m-3) and nutrient concentration was recorded in the coastal waters of Thiruvananthapuram. Even though off Mangalore (12° N) and off Goa (15° N) where upwelling was confined to narrow coastal zone, also showed high chlorophyll-a concentration, 3.98 mg m-3 and 6.31 mg m-3, respectively. The upwelled waters were dominated by centric diatoms (Thalassiosira sp.) and the non-upwelled waters (12° N and 15° N) were dominated by dinoflagellates. Microphytoplankton cell density was the highest along off Thiruvananthapuram (4.8×104 cells L-1), with maximum cell density along the coastal waters (1.4×104 cells L-1). Phytoplankton community of upwelled and non-upwelled waters showed significant variations with 60 % similarity between phytoplankton communities of upwelled waters

    Winter monsoon phytoplankton community in the coastal waters of Northeastern Arabian Sea, with emphasis on harmful and non-indigenous species

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    989-999Phytoplankton community structure along the coastal waters of the Northeastern Arabian Sea (NEAS) was analysed for three years (2009, 2011 and 2012) during the winter monsoon season. The coastal waters of NEAS, especially Saurashtra coast are a region of high fishery potential. A total of 137 species of phytoplankton were identified. The community structure of phytoplankton showed significant inter-annual variability. The study highlights the persistence of certain non-indigenous phytoplankton species such as Scrippsiella trochoidea, Karenia mikimotoi and potentially harmful dinoflagellates mainly Gonyaulax polygramma, Dinophysis acuminata, D. miles and Tripos furca in the region that can raise probable threats towards the indigenous species and can cause harmful or toxic events. The increased abundance of diatom, Pseudo-nitzschia spp. that can produce toxins at certain threshold levels was also observed. The possible reason for the increased abundance of such groups can be suggestively due to the increased anthropogenic inputs into the coastal waters and intense fishing and maritime activity in the area

    Mammalian Sperm Head Formation Involves Different Polarization of Two Novel LINC Complexes

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    Background: LINC complexes are nuclear envelope bridging protein structures formed by interaction of SUN and KASH proteins. They physically connect the nucleus with the peripheral cytoskeleton and are critically involved in a variety of dynamic processes, such as nuclear anchorage, movement and positioning and meiotic chromosome dynamics. Moreover, they are shown to be essential for maintaining nuclear shape. Findings: Based on detailed expression analysis and biochemical approaches, we show here that during mouse sperm development, a terminal cell differentiation process characterized by profound morphogenic restructuring, two novel distinctive LINC complexes are established. They consist either of spermiogenesis-specific Sun3 and Nesprin1 or Sun1g, a novel non-nuclear Sun1 isoform, and Nesprin3. We could find that these two LINC complexes specifically polarize to opposite spermatid poles likely linking to sperm-specific cytoskeletal structures. Although, as shown in co-transfection/ immunoprecipitation experiments, SUN proteins appear to arbitrarily interact with various KASH partners, our study demonstrates that they actually are able to confine their binding to form distinct LINC complexes. Conclusions: Formation of the mammalian sperm head involves assembly and different polarization of two novel spermiogenesis-specific LINC complexes. Together, our findings suggest that theses LINC complexes connect the differentiating spermatid nucleus to surrounding cytoskeletal structures to enable its well-directed shaping and elongation

    Beyond the Imitation Game: Quantifying and extrapolating the capabilities of language models

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    Language models demonstrate both quantitative improvement and new qualitative capabilities with increasing scale. Despite their potentially transformative impact, these new capabilities are as yet poorly characterized. In order to inform future research, prepare for disruptive new model capabilities, and ameliorate socially harmful effects, it is vital that we understand the present and near-future capabilities and limitations of language models. To address this challenge, we introduce the Beyond the Imitation Game benchmark (BIG- bench). BIG-bench currently consists of 204 tasks, contributed by 450 authors across 132 institutions. Task topics are diverse, drawing problems from linguistics, childhood develop- ment, math, common-sense reasoning, biology, physics, social bias, software development, and beyond. BIG-bench focuses on tasks that are believed to be beyond the capabilities of current language models. We evaluate the behavior of OpenAI's GPT models, Google- internal dense transformer architectures, and Switch-style sparse transformers on BIG-bench, across model sizes spanning millions to hundreds of billions of parameters. In addition, a team of human expert raters performed all tasks in order to provide a strong baseline. Findings include: model performance and calibration both improve with scale, but are poor in absolute terms (and when compared with rater performance); performance is remarkably similar across model classes, though with benefits from sparsity; tasks that improve gradually and predictably commonly involve a large knowledge or memorization component, whereas tasks that exhibit "breakthrough" behavior at a critical scale often involve multiple steps or components, or brittle metrics; social bias typically increases with scale in settings with ambiguous context, but this can be improved with prompting
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