188,626 research outputs found
Henry Charles Challis 1894-1917
No full text<p>Henry Charles Challis (1894-1917) was killed in the First World War on 28th April 1917. This document is a collection of reports from 2nd Oxford and Bucks Light Infantry, 2nd Battalion Highland Light Infantry, and Canadian War Diaries, and military records, connected to the Battle of Arleux. 28-29 Apr 1917 in which Henry Challis was killed.</p
Archaeological resource modelling in temperate river valleys: a case study from the Trent Valley, UK
No full textMethods for mapping and determining the condition of archaeological resources while they are still underground have been in development for nearly half a century. The authors here offer an example from the frontiers of the art: the application of a package of remote sensing procedures not only designed to locate sites but to model the valley deposits which contain and cover them. The variation in success of different methods in different deposits offers a guide to the design of evaluation projects on sand and gravel terrain everywhere
A generic toolkit for the visualization of archaeological features on airborne LiDAR elevation data
No full textA range of techniques have become established for the visualization and analysis of airborne LiDAR elevation data within the field of archaeology. In this paper we discuss the visualization of test data representing archaeological features in a variety of terrains using a suite of techniques, all available through generic geographical information system or image processing software. These comprise elevation shading using constrained colour ramps, slope analysis, hill-shading, principal component analysis of multi-azimuth hill-shading, local relief models and solar insolation modelling. The strengths and weaknesses of each technique are discussed and a generic toolkit, suited to the visualization of airborne LiDAR data for archaeological purposes, is presented. © 2011 John Wiley & Sons, Ltd
Method and parameters for genetic transformation of Streptococcus sanguis Challis
No full textA simple procedure for genetic transformation of Streptococcus sanguis Challis was developed and standardized. During the exponential phase of growth, cells became competent while growing as diplococci in broth containing 10% foetal calf serum. High levels of competence were maintained by the cultures for 60 min. Competent cells could be stored frozen without loss of competence for at least three years. Using total chromosomal DNA as donor, the dose-response curve for transformation of a point mutation (streptomycin resistance) showed one-hit kinetics, as the DNA concentration varied from 0.000001 to 10 micrograms/ml. At 10 micrograms/ml, more than 2.2% of the colony-forming units were transformed to streptomycin resistance, while transforming activity remained detectable with 1 pg of DNA/ml. Optimal time of exposure of competent cells to transforming DNA was 30 min. The transformation reaction was inhibited at 0 and 4 degrees C, whereas it occurred efficiently both at 25 and 37 degrees C
sj-pdf-1-spo-10.1177_17479541241247308 - Supplemental material for The relationship between ball mass and throw distance: Implications for coaching practice
No full textSupplemental material, sj-pdf-1-spo-10.1177_17479541241247308 for The relationship between ball mass and throw distance: Implications for coaching practice by John H. Challis in International Journal of Sports Science & Coaching</p
Expression of M6 protein of Streptococcus pyogenes on the surface of Streptococcus gordonii Challis
No full textThe M6 protein of Streptococcus pyogenes was expressed on the cell surface and secreted in Streptococcus gordonii Challis (formerly Streptococcus sanguis) after chromosomal integration of a promoterless M6 protein gene (emm-6.1). The ermC gene, conferring resistance to erythromycin, was cloned downstream of emm-6.1, within the same ClaI fragment. The initiation codon of emm-6.1 was 19 bp downstream of a ClaI site, so that ClaI cleavage would leave the gene promoterless. The ClaI fragment containing the promoterless emm-6.1 and ermC was ligated in vitro with a ClaI digest of S. gordonii chromosomal DNA. Random chromosomal integration of the heterologous DNA was obtained by using the ligation mixture to transform the naturally competent S. gordonii Challis. Twenty-eight percent of transformants selected for erythromycin resistance also expressed M6. Among the best M6 producers, 10 clones were selected for the stability of their phenotype. Nine of the 10 clones were shown to harbour one intact copy of the emm-6.1/ermC ClaI fragment integrated into the chromosome. These strains both expressed M6 protein on the surface and secreted different amounts of the molecule, since in each case the protein was produced after a transcriptional fusion of emm-6.1 with a different chromosomal promoter. A S. gordonii strain expressing large amounts of surface M6 protein, as judged by immunofluorescence and Western blot, was compared to the M- parental strain in a standard opsonophagocytosis assay. Of the isogenic pair, M6+ S. gordonii survived better in human blood and was phagocytosed at a slower rate
Method and parameters for genetic transformation of Streptococcus sanguis Challis
No full textA simple procedure for genetic transformation of Streptococcus sanguis Challis was developed and standardized. During the exponential phase of growth, cells became competent while growing as diplococci in broth containing 10% foetal calf serum. High levels of competence were maintained by the cultures for 60 min. Competent cells could be stored frozen without loss of competence for at least three years. Using total chromosomal DNA as donor, the dose-response curve for transformation of a point mutation (streptomycin resistance) showed one-hit kinetics, as the DNA concentration varied from 0.000001 to 10 micrograms/ml. At 10 micrograms/ml, more than 2.2% of the colony-forming units were transformed to streptomycin resistance, while transforming activity remained detectable with 1 pg of DNA/ml. Optimal time of exposure of competent cells to transforming DNA was 30 min. The transformation reaction was inhibited at 0 and 4 degrees C, whereas it occurred efficiently both at 25 and 37 degrees C
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
