163 research outputs found

    Late Jurassic of the Russian platform: Ammonite evolution and paleoenvironments

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    Κατά το τέλος το Αν. Ιουρασικού, στην Κεντρική Ρωσική λεκάνη έχει καταγραφεί μια σημαντική μείωση στην ποικιλότητα των αμμωνιτοειδών και έντονες μεταβολές στους μορφότυπους των οστράκων των αμμωνιτών. Κατά το τέλος του Βολγίου, οι αμμωνίτες αντιπροσωπεύονται από δύο μόνο γένη, που ανήκουν σε μία οικογένεια και τα οποία παρουσιάζουν μεγάλες μορφολογικές διαφορές στα όστρακα τους. Η μείωση της βιοποικιλότητας των αμμωνιτοειδών που παρατηρείται στο τέλος του Ιουρασικού, ξεκίνησε στο μέσο Βόλγιο και συσχετίζεται κυρίως με πτώση της θαλάσσιας στάθμηςDuring the terminal age of Late Jurassic a considerable decrease in ammonoid taxonomic diversity and distinct changes of ammonite shell morphotypes are recorded in the Central Russian Basin. By the end-Volgian, ammonites are represented by only two genera belonging to a single family, which differ markedly in their shell form. The end-Jurassic decrease in ammonoid biodiversity started in the mid-Volgian and is correlated first of all with shallowing of the se

    Mitigative Effect of Vitex Negundo against Fluoride induced Oxidative Stress Mediated Cardio and Nephrotoxicity

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    The present study investigated the mitigative effect of Vitex negundo against sodium fluoride (NaF) induced cardio and nephrotoxicity. The hydroalcoholic extract of Vitex negundo leaves (HAEVNL) was prepared by the maceration method. Group I, Group II, and Group III served as normal, toxic, and plant control groups in the treatment schedule. Group IV and V (200 and 400 mg/kg b.wt, p.o) served as treatment groups. Group II, IV, and V treated with NaF (100ppm) through drinking water for 4 weeks. Cardiac and kidney parameters such as LDH, CK-MB, Lipid profile, Creatinine, Urea, and Uric acid were estimated. The heart and kidney tissues LPO, GSH, SOD, and CAT levels and histopathological studies were performed. Phytochemical investigation showed the alkaloids, saponins, phytosterols, flavonoids, phenols, and tannins. Rats administered with NaF have demonstrated a significant rise in the LDH, CK-MB, TC, TG, LDL-C, VLDL-C, Creatinine, Urea, and Uric acid. Tissue LPO levels increased while there was a significant decrease in serum HDL-C and tissue SOD, GSH, and CAT levels. Treatment with HAEVNL showed effective recovery against NaF-induced cardio and nephrotoxicity. The histopathological evaluation also added to the benefits of the Vitex negundo leaves. The study concluded that Vitex negundo leaf extract showed a significant antioxidant and mitigative effect against fluoride- induced cardio and nephrotoxicity in rats

    Mytilus galloprovincialis Myticin C: A Chemotactic Molecule with Antiviral Activity and Immunoregulatory Properties

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    Previous research has shown that an antimicrobial peptide (AMP) of the myticin class C (Myt C) is the most abundantly expressed gene in cDNA and suppressive subtractive hybridization (SSH) libraries after immune stimulation of mussel Mytilus galloprovincialis. However, to date, the expression pattern, the antimicrobial activities and the immunomodulatory properties of the Myt C peptide have not been determined. In contrast, it is known that Myt C mRNA presents an unusual and high level of polymorphism of unidentified biological significance. Therefore, to provide a better understanding of the features of this interesting molecule, we have investigated its function using four different cloned and expressed variants of Myt C cDNA and polyclonal anti-Myt C sera. The in vivo results suggest that this AMP, mainly present in hemocytes, could be acting as an immune system modulator molecule because its overexpression was able to alter the expression of mussel immune-related genes (as the antimicrobial peptides Myticin B and Mytilin B, the C1q domain-containing protein MgC1q, and lysozyme). Moreover, the in vitro results indicate that Myt C peptides have antimicrobial and chemotactic properties. Their recombinant expression in a fish cell line conferred protection against two different fish viruses (enveloped and non-enveloped). Cell extracts from Myt C expressing fish cells were also able to attract hemocytes. All together, these results suggest that Myt C should be considered not only as an AMP but also as the first chemokine/cytokine-like molecule identified in bivalves and one of the few examples in all of the invertebrates

    Enhancing Capacities of Digital Extension and Advisory Services in Odisha, India

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    While several digital platforms and applications developed for farmers collect data and information, more is needed to know about their use by the Extension and Advisory Services (EAS) to provide more relevant advice or design a data-informed extension. This report discusses what needs to be done to enhance the capacities of EAS based on in-depth reviews of farmers' use of three digital farmer services available in Odisha and interactions with select stakeholders who are familiar with and are part of these services. We found that EAS stakeholders needed to be fully aware of the types of data and information available or how best they could be used. We identified that four specific types of capacities need to be strengthened coherently and systematically

    Study of water supply & sanitation practices in India using geographic information systems: some design & other considerations in a village setting

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    Background & objectives: Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrhoeal diseases. We examined the water and sanitation facilities of a village in southern India using geographic information system (GIS) tools. Methods: Places of residence, water storage and distribution, sewage and places where people in the village defaecated were mapped and drinking water sources were tested for microbial contamination in Nelvoy village, Vellore district, Tamil Nadu. Results: Water in the village was found to be microbiologically unfit for consumption. Analysis using direct observations supplemented by GIS maps revealed poor planning, poor engineering design and lack of policing of the water distribution system causing possible contamination of drinking water from sewage at multiple sites. Interpretation & conclusions: Until appropriate engineering designs for water supply and sewage disposal to suit individual village needs are made available, point-of-use water disinfection methods could serve as an interim solution

    First Evidence of Immunomodulation in Bivalves under Seawater Acidification and Increased Temperature

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    Water acidification, temperature increases and changes in seawater salinity are predicted to occur in the near future. In such a global climate change (GCC) scenario, there is growing concern for the health status of both wild and farmed organisms. Bivalve molluscs, an important component of coastal marine ecosystems, are at risk. At the immunological level, the ability of an organism to maintain its immunosurveillance unaltered under adverse environmental conditions may enhance its survival capability. To our knowledge, only a few studies have investigated the effects of changing environmental parameters (as predicted in a GCC scenario) on the immune responses of bivalves. In the present study, the effects of both decreased pH values and increased temperature on the important immune parameters of two bivalve species were evaluated for the first time. The clam Chamelea gallina and the mussel Mytilus galloprovincialis, widespread along the coast of the Northwestern Adriatic Sea, were chosen as model organisms. Bivalves were exposed for 7 days to three pH values (8.1, 7.7 and 7.4) at two temperatures (22 and 28°C). Three independent experiments were carried out at salinities of 28, 34 and 40 PSU. The total haemocyte count, Neutral Red uptake, haemolymph lysozyme activity and total protein levels were measured. The results obtained demonstrated that tested experimental conditions affected significantly most of the immune parameters measured in bivalves, even if the variation pattern of haemocyte responses was not always linear. Between the two species, C. gallina appeared more vulnerable to changing pH and temperature than M. galloprovincialis. Overall, this study demonstrated that climate changes can strongly affect haemocyte functionality in bivalves. However, further studies are needed to clarify better the mechanisms of action of changing environmental parameters, both individually and in combination, on bivalve haemocytes

    The evolutionary ecology of complex lifecycle parasites: linking phenomena with mechanisms

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    Many parasitic infections, including those of humans, are caused by complex lifecycle parasites (CLPs): parasites that sequentially infect different hosts over the course of their lifecycle. CLPs come from a wide range of taxonomic groups-from single-celled bacteria to multicellular flatworms-yet share many common features in their life histories. Theory tells us when CLPs should be favoured by selection, but more empirical studies are required in order to quantify the costs and benefits of having a complex lifecycle, especially in parasites that facultatively vary their lifecycle complexity. In this article, we identify ecological conditions that favour CLPs over their simple lifecycle counterparts and highlight how a complex lifecycle can alter transmission rate and trade-offs between growth and reproduction. We show that CLPs participate in dynamic host-parasite coevolution, as more mobile hosts can fuel CLP adaptation to less mobile hosts. Then, we argue that a more general understanding of the evolutionary ecology of CLPs is essential for the development of effective frameworks to manage the many diseases they cause. More research is needed identifying the genetics of infection mechanisms used by CLPs, particularly into the role of gene duplication and neofunctionalisation in lifecycle evolution. We propose that testing for signatures of selection in infection genes will reveal much about how and when complex lifecycles evolved, and will help quantify complex patterns of coevolution between CLPs and their various hosts. Finally, we emphasise four key areas where new research approaches will provide fertile opportunities to advance this field

    Whole genome analysis of a schistosomiasis-transmitting freshwater snail

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    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis
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