Wantage Community Hospital

A case study of new particle formation in the region downwind of a mesoscale convective system stretching across much of the central United States is presented. Airborne measurements were made of condensation nuclei (CN), cloud particle surface area, water vapor, and other gases. CN concentrations were greatly enhanced above and downwind of the cirrus anvil, with maximum concentrations of 45,000 per standard cm 3 . Volatility and electron microscope measurements indicated that most of the particles were likely to be small sulfate particles. The enhancement extended over at least a 600‐km region. Multivariate statistical analysis revealed that high CN concentrations were associated with surface tracers, as well as convective elements. Convection apparently brings gas‐phase particle precursors from the surface to the storm outflow region, where particle nucleation is favored by the extremely low temperatures. Simple calculations showed that deep convective systems may contribute to a substantial portion of the background aerosol in the upper troposphere at midlatitudes.

SUMMARY: The sensitization of Escherichia coli strain B/r to γ radiation was shown to take place within a few minutes of the addition of N-ethylmaleimide. Sensitization was demonstrated with as little as 0.0001 m-N-ethylmaleimide, but a much higher concentration (> 0.002 m) was necessary for any bactericidal effect. The N-ethyl-maleimide had to be present during irradiation in order to be effective. Staphylococcus aureus and a Pseudomonas sp. but not spores of Bacillus subtilis, were also sensitized by N-ethylmaleimide. The Pseudomonas sp. was only sensitized under anoxic conditions; this may indicate that, with this organism, N-ethylmaleimide and oxygen acted competitively in enhancing radiation damage. Possible mechanisms of sensitization are discussed.

Sterilization by gamma radiation has proved to be a suitable method for the treatment of a variety of laboratory animal diets intended for specified-pathogen-free (SPF) and germ-free colonies. Due to the high penetrating power of this radiation the diets can be packed before treatment in a manner which prevents recontamination during transport and storage. The main bulk of diets is used for SPF animals and a radiation dose of 2.5 Mrad has proved effective for the control of contaminating organisms. No adverse effects on animals receiving the diets have been noted, observations having been made on growth, reproduction and general health. Irradiated diets formulated according to current laboratory animal practice appear to be nutritionally satisfactory.

, 2021) on the use of dose quantities in radiological protection, under the same authorship as this Memorandum. Here, we present a brief summary of the main elements of the report. ICRP Publication 147 consolidates and clarifies the explanations provided in the 2007 ICRP Recommendations (Publication 103) but reaches conclusions that go beyond those presented in Publication 103. Further guidance is provided on the scientific basis for the control of radiation risks using dose quantities in occupational, public and medical applications. It is emphasised that best estimates of risk to individuals will use organ/tissue absorbed doses, appropriate relative biological effectiveness factors and dose-risk models for specific health effects. However, bearing in mind uncertainties including those associated with risk projection to low doses or low dose rates, it is concluded that in the context of radiological protection, effective dose may be considered as an approximate indicator of possible risk of stochastic health effects following low-level exposure to ionising radiation. In this respect, it should also be recognised that lifetime cancer risks vary with age at exposure, sex and population group. The ICRP report also concludes that equivalent dose is not needed as a protection quantity. Dose limits for the avoidance of tissue reactions for the skin, hands and feet, and lens of the eye will be more appropriately set in terms of absorbed dose rather than equivalent dose.

Journal Article The Distribution of some Inorganic Elements in Plant Tissue 2 Get access H. J. M. BOWEN, H. J. M. BOWEN Wantage Research LaboratoryBerks Search for other works by this author on: Oxford Academic PubMed Google Scholar P. A. CAWSE, P. A. CAWSE Wantage Research LaboratoryBerks Search for other works by this author on: Oxford Academic PubMed Google Scholar J. THICK J. THICK Wantage Research LaboratoryBerks Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Experimental Botany, Volume 13, Issue 2, May 1962, Pages 257–267, https://doi.org/10.1093/jxb/13.2.257 Published: 01 May 1962 Article history Received: 03 October 1961 Published: 01 May 1962

The grafting of methacrylic acid to 6,6‐nylon has been achieved by using the γ‐radiation from a 60 Co γ‐source. The effect of total radiation dosage and temperature on the rate of grafting is reported, and interpreted using current copolymerisation concepts. The effect of the new surface on the solubility of the nylon in various solvents, and on the surface electrical resistance, is also described and discussed briefly.

Abstract The effect of γ‐radiation on the protein nutritive value of certain animal feeds (protein concentrates), frozen whole egg, whole wheat and wheat gluten was measured by use of a microbiological method. There was little change in nutritive value of the animal feeds with doses of 0·5 and 1·0 Mrad and no change with frozen egg at.0·5 and 5·0 Mrad. Whole wheat showed no loss at 0·2 Mrad; a 6% loss at 1·0 Mrad was not increased further at 5·0 Mrad. Gluten prepared from wheat and then irradiated was unchanged at 0·02 Mrad but losses of 5, 7 and 26% were shown with doses of 0·2, 1·0 and 5·0 Mrad respectively. Following amino‐acid supplementation studies and microbiological assays for methionine, loss of availability of this amino‐acid was demonstrated to be principally responsible for the lowering of the nutritive value of the 5·0‐Mrad‐irradiated wheat gluten.

SummaryChinese hamster cells were exposed to a variety of treatments after gamma-irradiation. When DNA or protein synthesis was inhibited, there was no effect on survival. There was also no effect on survival from a reduction of temperature or the addition of caffeine. Actinomycin D, acriflavine, and ethidium bromide, which have the property of binding to nucleic acids, brought about a reduction in survival. It is suggested that the activity of any enzymes which repair radiation lesions in nucleic acids is impeded in a steric manner by the resulting complexes.

SUMMARY The exposure of tryptophan-requiring Escherichia coli b/r wp2 to u.v.- and γ-irradiation (in either order) results in more revertants than would be expected if the two treatments were independent. The excess mutants (‘interaction mutants’) were produced in increasing number by increasing doses of u. v.-or γ-radiation. Evidence is presented that the interaction occurs post-irradiation. Although the excision-repair and mutation frequency decline systems for u.v. damage are not involved in the interaction itself (since a strain deficient in these systems, E. coli wp2 her–, is no less efficient at producing interaction mutants than E. coli b/r wp 2) the u.v. component involved in interaction is sensitive to one or both of these systems as is shown by the very much lower u.v. doses at which interaction occurs in E. coli wp2 her–.

The sterilization by radiation of disposable medical items has been investigated. Various vegetative and spore-bearing bacteria have been irradiated and results indicate that 2.5 Mrad can be recommended to give a high degree of sterility. Spores of B. pumilus (E.601) showed such resistance that it might be a suitable test organism for determining the efficiency of a radiation treatment. A high standard of packaging must be demanded for pre-sterilized products.

SUMMARY: Radioactive phenyl mercuric chloride (labelled with 203Hg) was used to measure-SH groups in the mycelium and in the medium. Tritiated phenyl mercuric chloride was used as a quantitative cytological reagent. The changes in -SH concentration of the fungus were not always directly related to the changes in total S in Aspergillus niger, Penicillium chrysogenum 49.133, Eremothecium ashbyii and Candida albicans. A peak in -SH concentration occurred in the cells of these organisms during the early growth phase. Extracellular -SH compounds were produced by all these organisms at some time during development. Cytological studies showed differences in the distribution of -SH compounds in the cell wall and cytoplasm. E. ashbyii and C. albicans had a strong -SH reaction in the cell wall, A. niger and P. chrysogenum 49.133 a weak one. Sulphydryl compounds were most concentrated in areas of hyphal bud formation in E. ashbyii but were not concentrated at the hyphal tip.

SummaryNo change in survival of two Chinese hamster cell lines was found when any of the following inhibitors were added in various concentrations to the culture medium after exposure to ultra-violet light: acriflavine, caffeine, theophylline, chloramphenicol, cycloheximide, actinomycin D and hydroxyurea. Acridine orange, puromycin and reduced temperature were tested with one of the cell-lines and were without effect.

Among the many factors thought to influence the orientation associations in interchange heterozygotes, previous evidence suggests that there is a genetically controlled mechanism (or mechanisms) which is distinct from that varying the position and number of chiasmata. In rye, variation between 50% and 90% disjunction frequency has been ascribed to this mechanism. Nevertheless, in this species, directed segregation has been found in newly arising interchanges, suggesting that the genetic constitution has been selected to give a high disjunction frequency. Two alternative explanations for these findings were considered. First, the influence on orientation may be a secondary effect of factors whose primary effect is of selective importance in normal, non- interchange individuals. Second, direct selection for a high disjunction frequency may have occurred in a manner analogous to Fisher's theory of the evolution of dominance. (auth)

Microsporum canis is the causative organism in less than 10% of all tinea capitis infections in the UK. Transmission is generally via contact with an infected family pet and there are only rare reports of case clustering. This article describes an outbreak of M. canis in a primary school classroom demonstrating human-to-human spread from an index case who was presumed to have acquired the infection prior to arriving in the UK. There was no suggestion of clinical improvement following 4 weeks of oral terbinafine 125 mg daily and treatment was changed to griseofulvin. The Health Protection team screened class members and confirmed cases (either clinically or mycologically) were also treated with griseofulvin 10-20 mg/kg/day for 10 weeks. Classmates and siblings of classmates were recommended to use selenium sulphide or ketoconazole-containing shampoo twice weekly.

SUMMARY: The effect of chemical sensitizing and protective agents on the rate of mutation induction by gamma radiation in strain WP2 of Escherichia coli B/r was studied. This organism will not grow in the absence of tryptophan but it mutates spontaneously at a very low rate, and under the influence of radiation at a much higher rate, to stable forms which can grow in the absence of tryptophan. Both inactivation and mutation-induction were apparently related to radiation dose by an exponential function in the absence of modifying agents; in their presence this was not always the case. The sensitizing agents oxygen and AT-ethylmaleimide, and the protective agents cysteine, glycerol, dimethyl sulphoxide and thiourea, affected both the inactivating and mutation-inducing actions of radiation though not always to the same extent.

AIMS: Periprosthetic joint infection (PJI) is a debilitating condition with a substantial socioeconomic burden. A novel autologous blood glue (ABG) has been developed, which can be prepared during surgery and sprayed onto prostheses at the time of implantation. The ABG can potentially provide an antimicrobial coating which will be effective in preventing PJI, not only by providing a physical barrier but also by eluting a well-known antibiotic. Hence, this study aimed to assess the antimicrobial effectiveness of ABG when impregnated with gentamicin and stem cells. METHODS: Gentamicin elution from the ABG matrix was analyzed and quantified in a time-dependent manner. The combined efficiency of gentamicin and ABG as an anti-biofilm coating was investigated on titanium disks. RESULTS: ABG-gentamicin was bactericidal from 10 μg/ml and could release bactericidal concentrations over seven days, preventing biofilm formation. A concentration of 75 μg/ml of gentamicin in ABG showed the highest bactericidal effect up to day 7. On titanium disks, a significant bacterial reduction on ABG-gentamicin coated disks was observed when compared to both uncoated (mean 2-log reduction) and ABG-coated (mean 3-log reduction) disks, at days 3 and 7. ABG alone exhibited no antimicrobial or anti-biofilm properties. However, a concentration of 75 μg/ml gentamicin in ABG sustains release over seven days and significantly reduced biofilm formation. Its use as an implant coating in patients with a high risk of infection may prevent bacterial adhesion perioperatively and in the early postoperative period. CONCLUSION: 2020;9(12):848-856.

The use of a gamma radiation process for the elimination of Salmonella from frozen meat is considered with particular reference to the treatment of boned-out horsemeat and kangaroo meat imported into the UK and intended for use as pet meat.Examination of dose/survival curves produced for several serotypes of Salmonella in frozen meat shows that a radiation dose of 0.6 Mrad. will reduce a population by at least a factor of 10(5). The influence on the radiation resistance of salmonellas of such factors as preirradiation growth in the meat and temperature during irradiation have been examined and considered. It is also demonstrated with both preinoculated and naturally contaminated meat that postirradiation storage in the frozen state does not lead to the revival of irradiated salmonellas.The properties of Salmonella survivors deliberately produced in meat using conditions of irradiation designed to simulate a commercial process are studied after six recycling treatments through the process. There were no important changes in characteristics normally used for identification of Salmonella but radiation resistance was lowered. Survivors grown in situ in meat after irradiation showed an abnormally long lag phase, and removal of competitive microflora in meat by the radiation treatment can influence the growth of salmonellas.

The influence on allelic recombination of non-lethal doses of gamma radiation delivered at different stages during meiosis has been determined and the data compared with previous results concerning gene recombination. Both kinds of recombination are influenced at only two, probably the same two, meiotic stages. During the first sensitive stage, probably in preleptotene, the frequency of allelic recombination is increased, but that of gene recombination decreased. The frequency of both is increased during the second sensitive stage, which is probably in pachytene.

Developing a geometric formulation of any biological object has a number of justifications and applications. Recently, we developed a universal geometric figure for describing a bird's egg in any of the possible basic shapes: spherical, ellipsoidal, ovoid, and pyriform. The formulation proved widely applicable but had a number of drawbacks, including a very obvious join between two parts of the egg. To correct this, we developed the Main Axiom of the universal mathematical formula. This essentially involved making the ordinate of the extremum of the function correspond to half the maximum egg breadth (B), and the abscissa to the reciprocal of the parameter w that reflects the shift of the vertical axis to its coincidence with B. This, in turn, helped us develop a new, simplified mathematical model without a nonbiological join. Experimental verification was performed to confirm the adequacy of the new geometric figure. It accurately described actual avian eggs of various shapes more closely than our previous model. To the best of our knowledge, our new, simplified equation can be applied as a standard for any bird egg that exists in nature. As a rather simple equation, it can be used in a broad range of applications.

Abstract By use of microbiological methods of assay, the effect of γ‐radiation at doses of 0·5 Mrad and 5·0 Mrad on the content of some B‐complex vitamins in frozen whole egg has been studied. For comparative purposes, analyses were also performed on egg treated by a heat‐pasteurisation process designed to eliminate salmonellae food‐poisoning organisms. No change was apparent in pantothenic acid, biotin and riboflavin after any of the treatments. A 24% loss of thiamine occurred at 0·5 Mrad and this was increased to 61% at 5·0 Mrads. Similar analyses were made on Manitoba wheat irradiated at 0·02 Mrad, which is approximately the dose required for grain disinfestation, and also at ten times this dose. No apparent change was observed in the contents of nicotinic acid, thiamine, riboflavin, biotin and total vitamin B 6 after irradiation at 0·02 Mrad; pantothenic acid showed a slight loss at this dose. At 0·2 Mrad a loss of 12% nicotinic acid, 11% pantothenic acid and 10% biotin occurred.