Search results for " Library"
showing 10 items of 734 documents
Antibiotics and food in the American press
2021
AbstractThe emergence of antimicrobial resistant infections from food is well documented in the scientific literature but, in this kind of matter, the public opinion is an important policy driver and is vastly forged by traditional media. Here, we propose a text mining study through about 500 articles from two reference daily U.S. newspapers to assess the media coverage of this issue. Our results indicate that, since the middle of the 80s, the two journals considered here adopted a very different narrative around the issue, echoing civil society concerns in one case and the official discourse in the other.
Learning Molecular Classes from Small Numbers of Positive Examples Using Graph Grammars
2021
We consider the following problem: A researcher identified a small number of molecules with a certain property of interest and now wants to find further molecules sharing this property in a database. This can be described as learning molecular classes from small numbers of positive examples. In this work, we propose a method that is based on learning a graph grammar for the molecular class. We consider the type of graph grammars proposed by Althaus et al. [2], as it can be easily interpreted and allows relatively efficient queries. We identify rules that are frequently encountered in the positive examples and use these to construct a graph grammar. We then classify a molecule as being conta…
Introduction of Cytochrome P-450 Genes into V79 Chinese Hamster Cells to Generate New Mutagenicity Test Systems
1989
Usually, cultivated cells have poor capabilities to metabolize promutagens and procarcinogens. This is particularly true for cells that grow fast and have a high cloning efficiency, as is the case with V79 Chinese hamster cells. For this reason, these cells are being extensively used in mutagenicity tests. But, due to the fact that particularly these cells lack cytochrome P-450 activities, promutagens and procarcinogens have to be incubated with an exogenous metabolizing system, e.g. liver homogenate preparations, in order to generate reactive metabolites. These extracellularly generated metabolites are then given to V79 cells in order to check for their potency to mutate the chromosomal DN…
Interrogation of genomes by molecular copy-number counting (MCC)
2006
Human cancers and some congenital traits are characterized by cytogenetic aberrations including translocations, amplifications, duplications or deletions that can involve gain or loss of genetic material. We have developed a simple method to precisely delineate such regions with known or cryptic genomic alterations. Molecular copy-number counting (MCC) uses PCR to interrogate miniscule amounts of genomic DNA and allows progressive delineation of DNA content to within a few hundred base pairs of a genomic alteration. As an example, we have located the junctions of a recurrent nonreciprocal translocation between chromosomes 3 and 5 in human renal cell carcinoma, facilitating cloning of the br…
cDNA Synthesis and Cloning
1998
The isolation of intact messenger RNA and its conversion into cDNA copies by avian or Moloney murine reverse transcriptase, as well as subsequent amplification of gene transcripts by the PCR technique, are becoming increasingly important tools in molecular biology. At present, these techniques have been often necessary and widely used for the analysis of individual mRNA levels in cells and tissues by Northern blot analysis, nuclease protection analysis and in situ hybridization. Another important application of RNA templates is the construction of representative cDNA libraries in order to clone genes, to investigate their molecular structure and to express them in prokaryotic and/or eukary…
Identification of Tumor-Associated Autoantigens With SEREX
2004
Serological analysis of tumor antigens by recombinant cDNA expression cloning (SEREX) allows the systematic cloning of tumor antigens recognized by the spontaneous autoantibody repertoire of cancer patients. For SEREX, cDNA expression libraries are constructed from fresh tumor specimens, packaged into lambda-phage vectors, and expressed recombinantly in Escherichia coli. Recombinant proteins expressed during the lytic infection of bacteria are transferred onto nitrocellulose membranes to be probed with diluted autologous patient serum for identification of clones reactive with high-titered IgG antibodies. This chapter describes the SEREX technology in detail.
Cloning and Characterization of Overlapping DNA Fragments of the Toxin A Gene of Clostridium difficile
1989
Clostridium difficile, a human pathogen, produces two very large protein toxins, A and B (250-600 kDa), which resist dissociation into subunits. To clone the toxin A gene, a genomic library of 3-8 kb chromosomal DNA fragments of C. difficile strain VPI 10463 established in pUC12 was screened with a rabbit polyclonal toxin A antiserum. Thirty-five clones were isolated which carried 2.5-7.0 kb inserts representing a 10 kb region of the C. difficile genome. All the inserts were oriented in the same direction, suggesting that toxin A gene expression was under control of the lac promoter of the pUC12 vector. Western blot experiments revealed the presence of low amounts of fusion proteins of vari…
Sequencing and analysis of the gene encoding the α-toxin of Clostridium novyi proves its homology to toxins A and B of Clostridium difficile
1995
A library of total Clostridium novyi DNA was established and screened for the alpha-toxin gene (tcn alpha) by hybridization with oligonucleotides derived from a partial N-terminal sequence and by using specific antisera. Overlapping subgenic tcn alpha fragments were isolated and subsequently the total sequence of tcn alpha was determined. The 6534 nucleotide open reading frame encodes a polypeptide of M(r) 250,166 and pI 5.9. The N-terminal alpha-toxin (Tcn alpha) sequence MLITREQLMKIASIP determined by Edman degradation confirmed the identity of the reading frame and the assignment of the translation start point. The toxin is not modified posttranslationally at its N-terminus nor does it co…
Les manuscrits de l’époque romane dans les listes de livres des établissements bénédictins bourguignons (XIe-XIVe siècle)
2017
International audience
Comparison of Metrics for the Classification of Soils Under Variable Geometrical Conditions Using Hyperspectral Data
2008
International audience; The objective of this letter is to find a distance metric between reflectance spectra that is not sensitive to the variations on the soil reflectance induced by the geometry of solar-view angles. This is motivated by the fact that differences between spectra measured for the same soil under different observation and illumination configurations can lead to misclassifications. Using 26 soils of different compositions simulated with Hapke’s model and 92 soils of different compositions measured under 28 solarview angle geometries in laboratory conditions, we tested three metrics, namely, root-mean-square error, spectral angle mapper, and R2 (the coefficient of determinat…