The oxidation of porus carbon: the development of porosity of a cellulose carbon by reaction with oxygen

The work reported in the thesis is an examination of the influence of temperature of activation on the development of microporosity in a polymer carbon. It involves the investigation of the rate of reaction with oxygen over the temperature range 400 - 726 C and the measurement of the porosity produced by adsorptive methods. It was concluded from experimental activation energies obtained for the reaction that the temperature ranges 400 - 460 C and 480 - 726 C were in Zones II and III respectively of the classification of Heddon and Wicke*. These conclusions were supported by investigation of the influence of partial pressure of oxygen, sample weight and crucible geometry on the rate of reaction. Analysis of adsorption isotherms shows that the development of porosity depends on the temperature of activation. In Zone III where reaction is on the external surface of the carbon there is little or no development of porosity whereas in Zone II where the reaction occurs within the pores of the carbon, substantial development of porosity occurs. A method for the determination of the thermodynamic criterion, ΔS < 0, for the applicability of the Dubinin Theory to the adsorption isotherms was developed. Application of the Dubinin Equation to the regions of the isotherms where the Thermodynamic criterion was shown to apply gave lines that were not generally straight as originally postulated. However analysis of the results in terms of the Dubinin Equation in general confirmed the effects of temperature of activation on the development of porosity. Comparison of oxygen and carbon dioxide as activating gasses was made by reference to Rowan’s work and showed that under comparable conditions of activation carbon dioxide is a more efficient activating gas

Modern mammography screening and breast cancer mortality: population study

Objective: To evaluate the effectiveness of contemporary mammography screening using individual information about screening history and breast cancer mortality from public screening programmes. Design: Prospective cohort study of Norwegian women who were followed between 1986 and 2009. Within that period (1995-2005), a national mammography screening programme was gradually implemented, with biennial invitations sent to women aged 50-69 years. Participants: All Norwegian women aged 50-79 between 1986 and 2009. Main outcome measures Multiple Poisson regression analysis was used to estimate breast cancer mortality rate ratios comparing women who were invited to screening (intention to screen) with women who were not invited, with a clear distinction between cases of breast cancer diagnosed before (without potential for screening effect) and after (with potential for screening effect) the first invitation for screening. We took competing causes of death into account by censoring women from further follow-up who died from other causes. Based on the observed mortality reduction combined with the all cause and breast cancer specific mortality in Norway in 2009, we used the CISNET (Cancer Intervention and Surveillance Modeling Network) Stanford simulation model to estimate how many women would need to be invited to biennial mammography screening in the age group 50-69 years to prevent one breast cancer death during their lifetime. Results: During 15 193 034 person years of observation (1986-2009), deaths from breast cancer occurred in 1175 women with a diagnosis after being invited to screening and 8996 women who had not been invited before diagnosis. After adjustment for age, birth cohort, county of residence, and national trends in deaths from breast cancer, the mortality rate ratio associated with being invited to mammography screening was 0.72 (95% confidence interval 0.64 to 0.79). To prevent one death from breast cancer, 368 (95% confidence interval 266 to 508) women would need to be invited to screening. Conclusion: Invitation to modern mammography screening may reduce deaths from breast cancer by about 28%

Relation of Growth Rate from Birth to Three Months and Four to Six Months to Body Mass Index at Ages Four to Six Years

Background. While rapid early weight gain are common in children who become obese later in life, so is growth faltering in the first 3 months of life. Objective. We seek to determine what relationship weight gain in the first six months of age, separated into two 3-month periods, have with the BMI of children ages 4 to 6 years in an inner-city community. Subjects. A convenience sample cohort of 154 children attending an inner-city clinic. Methods. Consecutive charts were reviewed retrospectively. Age, gender, birth weight and weight change in the first and second 3 months of life were introduced as fixed factors using mixed linear models with BMI in years 4 to 6 as the dependent variable. Results. Weight change quartile in the first 3 months of life did not predict of BMI in years 4 to 6; however, weight changes quartiles during months 4 to 6 were significant predictors for subsequent overweight. Conclusion. The data presented herein suggest that, for this specific population, weight gain can be promoted when it is most essential. It is necessary, however, to identify intermediary variables that could affect outcomes in this and other communities

Understanding recent trends in incidence of invasive breast cancer in Norway: age-period-cohort analysis based on registry data on mammography screening and hormone treatment use

Objective To quantify the separate contributions of menopausal hormone treatment and mammography screening activities on trends in incidence of invasive breast cancer between 1987 and 2008

Integrated stratigraphy of the Kimmeridge Clay Formation (Upper Jurassic) based on exposures and boreholes in south Dorset, UK

For the purposes of a high-resolution multi-disciplinary study of the Upper Jurassic Kimmeridge Clay Formation, two boreholes were drilled at Swanworth Quarry and one at Metherhills, south Dorset, UK. Together, the cores represent the first complete section through the entire formation close to the type section. We present graphic logs that record the stratigraphy of the cores, and outline the complementary geophysical and analytical data sets (gamma ray, magnetic susceptibility, total organic carbon, carbonate, [delta]13Corg). Of particular note are the new borehole data from the lowermost part of the formation which does not crop out in the type area. Detailed logs are available for download from the Kimmeridge Drilling Project web-site at http://kimmeridge.earth.ox.ac.uk/. Of further interest is a mid-eudoxus Zone positive shift in the [delta]13Corg record, a feature that is also registered in Tethyan carbonate successions, suggesting that it is a regional event and may therefore be useful for correlation. The lithostratigraphy of the cores has been precisely correlated with the nearby cliff section, which has also been examined and re-described. Magnetic-susceptibility and spectral gamma-ray measurements were made at a regular spacing through the succession, and facilitate core-to-exposure correlation. The strata of the exposure and core have been subdivided into four main mudrock lithological types: (a) medium-dark–dark-grey marl; (b) medium-dark–dark grey–greenish black shale; (c) dark-grey–olive-black laminated shale; (d) greyish-black–brownish-black mudstone. The sections also contain subordinate amounts of siltstone, limestone and dolostone. Comparison of the type section with the cores reveals slight lithological variation and notable thickness differences between the coeval strata. The proximity of the boreholes and different parts of the type section to the Purbeck–Isle of Wight Disturbance is proposed as a likely control on the thickness changes

Cytokine receptor expression in human lymphoid tissue: analysis by fluorescence microscopy

A highly-sensitive flourescence method, capable of detecting cytokine receptors present at low concentrations (around I DO molecules per cell) by flow cytometry, was adapted for use on tissue sections. This method was used to examine the expression of several cytokine receptors in lymphoid ti ss ues. lL-2 receptors were distributed broadly, with higher concentrations in T cell areas. lL-1 receptor Type I was detected in T cell areas and in the follicular mantle, and was strongly expressed on vasc ular endothelium. IL-6 receptor was found at very low concentration, both within and outside germinal centres. The gp 130 molecule, which is involved in the functional receptor complex for IL-6 and several other cytokines, was present at higher concentrations, particularly in the germinal centre. Analysis of receptor expression in secondary lymphoid tissue provides evidence bearing on the physiological roles of cytokines, as these tissues contain cells at various stages of physiological activation located in well-defined functional zones.Heddy Zola, Jodie Ridings, Helen Weedon, Michael Fusco, Roger W. Byard, Peter J. Macardl

Anpassung und Eignung von Composite Cross Winterweizen- Populationen und anderen Phänotypen auf unterschiedliche N-Versorgungsniveaus

Evolutionary breeding through the introduction of composite cross populations (CCPs)encourages intra-specific diversity and increases diversity in the agricultural landscape. Increased genetic diversity in crops may help to buffer both biotic and abiotic stresses and will play an increasingly important role in unpredictable climatic conditions become more unpredictable (Østergård et al. 2009). A number of CC winter wheat populations, commercial varieties and CCP line selections were tested at the University of Kassel, under differing N input levels in order to test past adaptation and suitability to differing fertilisation levels. The CCPs have been managed since 2005 under both organic and conventional conditions without conscious selection. Genetically diverse CCPs have the ability to be able to adapt to their environment, which may also include the management system, meaning that CCPs grown under conventional conditions may be better suited to growing conditions with higher N inputs, in comparison to CCPs, which have been managed organically under low N levels

Leistung und agronomisches Potenzial von Composite Cross Winterweizen-Populationen und anderen Phänotypen in einem Mischanbausystem

Unpredictable climatic conditions and increasing pressure on non-renewable resources mean that alternative agricultural systems able to cope with increasing biotic and abiotic stresses, as well as external input costs, are needed. Sustainable agricultural systems should be self-regulating, characterized by a high degree of interand intra-specific diversity (Moreau 2010). Evolutionary breeding through the introduction of Composite Cross Populations (CCPs) increases intra-specific diversity, enabling CCPs to adapt to changing environmental conditions. Increasing interspecific diversity, through mixed cropping, also plays an important role in sustainable systems and suitable crops are needed that are able to cope with the increasing interspecific competition found in these mixed systems. A number of winter wheat CCPs, lines and commercial varieties were tested with white clover as an undersowing in order to test competitive ability and performance