1,737 research outputs found

    Cytometric analysis, genetic manipulation and antibiotic selection of the snail embryonic cell line Bge from Biomphalaria glabrata, the intermediate host of Schistosoma mansoni.

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    The invertebrate cell line, Bge, from embryos of the snail Biomphalaria glabrata, remains to date the only established cell line from any species of the Phylum Mollusca. Since its establishment in 1976 by Eder Hansen, few studies have focused on profiling its cytometrics, growth characteristics or sensitivity to xenobiotics. Bge cells are reputed to be challenging to propagate and maintain. Therefore, even though this cell line is a noteworthy resource, it has not been studied widely. With growing interest in functional genomics, including genetic transformation, to elucidate molecular aspects of the snail intermediate hosts responsible for transmission of schistosomiasis, and aiming to enhance the convenience of maintenance of this molluscan cell line, we deployed the xCELLigene real time approach to study Bge cells. Doubling times for three isolates of Bge, termed CB, SL and UK, were longer than for mammalian cell lines - longer than 40 h in complete Bge medium supplemented with 7% fetal bovine serum at 25 °C, ranging from ∼42 h to ∼157 h when 40,000 cells were seeded. To assess the potential of the cells for genetic transformation, antibiotic selection was explored. Bge cells were sensitive to the aminonucleoside antibiotic puromycin (from Streptomyces alboniger) from 5 μg/ml to 200 ng/ml, displaying a half maximal inhibitory concentration (IC50) of ∼1.91 μg/ml. Sensitivity to puromycin, and a relatively quick kill time (<48 h in 5 μg/ml) facilitated use of this antibiotic, together with the cognate resistance gene (puromycin N-acetyl-transferase) for selection of Bge cells transformed with the PAC gene (puroR). Bge cells transfected with a plasmid encoding puroR were partially rescued when cultured in the presence of 5 μg/ml of puromycin. These findings pave the way for the development of functional genomic tools applied to the host-parasite interaction during schistosomiasis and neglected tropical trematodiases at large

    DDT Granules - A New Way to Kill Corn Borers

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    The European corn borer actually is a misnamed insect. At least two-thirds of the worm stage of its life is spent feeding on the surface of leaves and leaf sheaths. Only during the latter part of its life does it tunnel into the stalk and become a borer

    Developing automated methods to estimate spectrally resolved direct normal irradiance for solar energy applications

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    We describe four schemes designed to estimate spectrally resolved direct normal irradiance (DNI) for multi-junction concentrator photovoltaic systems applications. The schemes have increasing levels of complexity in terms of aerosol and circumsolar irradiance (CSI) treatment, ranging from a climatological aerosol classification with no account of CSI, to an approach which includes explicit aerosol typing and type dependent CSI contribution. When tested against ground-based broadband and spectral measurements at five sites spanning a range of aerosol conditions, the most sophisticated scheme yields an average bias of þ 0:068%, well within photometer calibration uncertainties. The average spread of error is 2:5%. These statistics are markedly better than the climatological approach, which carries an average bias of 1:76% and a spread of 4%. They also improve on an intermediate approach which uses Angstrom€ exponents to estimate the spectral variation in aerosol optical depth across the solar energy relevant wavelength domain. This approach results in systematic under and over-estimations of DNI at short and long wavelengths respectively. Incorporating spectral CSI particularly benefits sites which experience a significant amount of coarse aerosol. All approaches we describe use freely available reanalyses and software tools, and can be easily applied to alternative aerosol measurements, including those from satellite

    Solar cooking in the sahel

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    Solar cookers are a cheap, practical tool for sustainable development, which can be built and maintained without access to expensive tools or machinery. Solar cookers require direct sunshine for effective cooking, so clouds or heavy atmospheric dust loads can slow down or prevent their use. Surface meteorological (SYNOP) stations record the daily hours of direct sunshine and were used to generate climatology of days with greater than 6 h available for cooking. The SYNOP dataset is very sparse in many parts of Africa and therefore is complemented by the use of geostationary satellite data. Higher temporal resolution surface insolation records are derived from SEVIRI (Spinning Enhanced Visible and Infrared Imager) on board the Meteosat Second Generation satellite series by EUMETSAT's Land Satellite Application Facility, but the approach uses fixed aerosol climatology. Direct surface solar irradiance was derived using the Beer-Lambert law using AODs retrieved from SEVIRI. Validation indicates that its capabilities are strongest over drier and less vegetated surfaces such as those found in the Sahara and Sahel. Biomass-burning aerosol may be significant over the Sahel in winter, and SEVIRI AODs may miss this unless it is masked as cloud, although here SYNOP values are still greater than those from SEVIRI

    The Sinbad retrotransposon from the genome of the human blood fluke, Schistosoma mansoni, and the distribution of related Pao-like elements

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    BACKGROUND: Of the major families of long terminal repeat (LTR) retrotransposons, the Pao/BEL family is probably the least well studied. It is becoming apparent that numerous LTR retrotransposons and other mobile genetic elements have colonized the genome of the human blood fluke, Schistosoma mansoni. RESULTS: A proviral form of Sinbad, a new LTR retrotransposon, was identified in the genome of S. mansoni. Phylogenetic analysis indicated that Sinbad belongs to one of five discreet subfamilies of Pao/BEL like elements. BLAST searches of whole genomes and EST databases indicated that members of this clade occurred in species of the Insecta, Nematoda, Echinodermata and Chordata, as well as Platyhelminthes, but were absent from all plants, fungi and lower eukaryotes examined. Among the deuterostomes examined, only aquatic species harbored these types of elements. All four species of nematode examined were positive for Sinbad sequences, although among insect and vertebrate genomes, some were positive and some negative. The full length, consensus Sinbad retrotransposon was 6,287 bp long and was flanked at its 5'- and 3'-ends by identical LTRs of 386 bp. Sinbad displayed a triple Cys-His RNA binding motif characteristic of Gag of Pao/BEL-like elements, followed by the enzymatic domains of protease, reverse transcriptase (RT), RNAseH, and integrase, in that order. A phylogenetic tree of deduced RT sequences from 26 elements revealed that Sinbad was most closely related to an unnamed element from the zebrafish Danio rerio and to Saci-1, also from S. mansoni. It was also closely related to Pao from Bombyx mori and to Ninja of Drosophila simulans. Sinbad was only distantly related to the other schistosome LTR retrotransposons Boudicca, Gulliver, Saci-2, Saci-3, and Fugitive, which are gypsy-like. Southern hybridization and bioinformatics analyses indicated that there were about 50 copies of Sinbad in the S. mansoni genome. The presence of ESTs representing transcripts of Sinbad in numerous developmental stages of S. mansoni along with the identical 5'- and 3'-LTR sequences suggests that Sinbad is an active retrotransposon. CONCLUSION: Sinbad is a Pao/BEL type retrotransposon from the genome of S. mansoni. The Pao/BEL group appears to be comprised of at least five discrete subfamilies, which tend to cluster with host species phylogeny. Pao/BEL type elements appear to have colonized only the genomes of the Animalia. The distribution of these elements in the Ecdysozoa, Deuterostomia, and Lophotrochozoa is discontinuous, suggesting horizontal transmission and/or efficient elimination of Pao-like mobile genetic elements from some genomes

    Public Beach Assessment Report Central Beach and Castlewood Park Beach Colonial Beach, Virginia

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    The purpose of this report is to document the recent history of Colonial Beach’s Potomac River shoreline as well as assess the historical shoreline evolution and status of the beach zone. Review of previously-published literature, field survey data, aerial photos, and computer modeling were used to address the study objectives

    Activity of eribulin mesylate in heavily pretreated breast cancer granted accessvia the Cancer Drugs Fund

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    Aim: Eribulin mesylate is a synthetic analog of halichondrin B and is licensed for the treatment of patients with locally advanced or metastatic breast cancer that has progressed following treatment with anthracyclines and taxanes. It was not deemed to be cost effective based on a cost analysis by the National Institute for Health and Care Excellence in England and therefore it is not funded routinely by the National Health Service. The establishment of the Cancer Drugs Fund in England subsequently enabled access. As with any new chemotherapy drug that enters clinical practice for metastatic breast cancer (MBC) it is often used in heavily pretreated patients and the experience in a routine clinical setting can differ from that in a clinical study. We therefore present the experience of the first 25 cases treated at our institution via the Cancer Drugs Fund. Materials &amp; methods: A total of 25 patients were treated and in the 22 assessable cases the objective response rate was 18% (four out of 22), with a clinical benefit rate of 41.0% (9 out of 22). Results: The median time-to-progression and overall survival were 4.08 months and 5.89 months, respectively. There was a significant difference in clinical benefit rate (odds ratio: 0.065; 95% CI: 0–0.529; p = 0.0055), as well as time-to-progression (hazard ratio: 9.18; 95% CI: 2.26–37.38; p = 0.002 adjusted for age at diagnosis and interval between initial MBC diagnosis and commencing eribulin) favoring those patients who had not been rechallenged. There was no significant difference in overall survival (hazard ratio: 1.16; 95% CI: 0.44–3.05; p = 0.770 adjusted for age at diagnosis and interval between initial diagnosis of MBC and commencing eribulin). Conclusion: Eribulin mesylate shows clinical activity; however, there appears to be differences in terms of benefit in patients based on whether patients have been rechallenged with an anthracycline and/or a taxane. These data require confirmation in larger patient groups
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