Ignition of binary alloys of uranium

Experiments determine the effect of alloying additives on the ignition of uranium. Data on oxidation rates, ignition temperatures, and burning curves are provided in the report

Reevaluation of species concepts of uppermost cretaceous unionidae (mollusca: bivalvia) : Hell Creek formation, Montana, U.S.A.

Species are the basic units of life relative to taxonomy, and a practical definition of species is imperative to paleontology in order to promote reproducible, unambiguous criteria for accurately interpreting past species relationships. The need for a well-defined rubric for identifying species is evident in the freshwater mussel assemblage (Family Unionidae) in the Hell Creek Formation. The Hell Creek Formation unionid species were first described by Whitfield in 1903 and 1907. His descriptions were often based on differences of a single trait. In 197 6, Russell reevaluated the original species descriptions, I but still based the classification of species on only a few qualitative morphologic differences. These previous species diagnoses did not incorporate phenetics (based on morphologic similarity) or cladistics (based on evolutionary relationships). As a result, the assignment of morphologically similar specimens to previously defined species is sometimes problematic. Additionally, without more knowledge, certain species may not clearly be considered distinct. The goal of this study is to reevaluate four sister species sets in order to assess their validity as species using an analytical approach instead of relying on the traditional qualitative approach. Species diagnosis on the basis of a single trait or very few traits, as employed in the previous species descriptions, is not likely adequate to support the classification as distinct species or to show the relationships among species. To test the validity of species in the Hell Creek Formation, an extensive database of quantitative and qualitative character traits was constructed to be applied to various quantitative models. The morphological distinction of each species was ascertained by using discriminant and cluster analyses. The species distinction based on evolutionary relationships was also tested using cladistic methods. Comparing morphologic differences without quantitative analysis, all eight species display significant morphologic differences, implying that they are discrete species. Discriminant analysis distinguished all eight species on the basis of quantitative traits; however, many sister species were indistinguishable solely on the basis of qualitative traits. Cluster analysis displayed apparent structure in the dendrogram that loosely applied to eight distinct species, but in some cases, there was substantial intermixing of specimens otherwise assigned to the recognized species observed in the clusters. Cladistics displayed minimal resolution in the phylogenetic relationships between species and was not able to distinguish between sisters species on the basis of the criteria given. The results herein suggest that each species is distinct on the basis of their morphology as shown by species comparison with and without quantitative models. Interpretation of the evolutionary relationships among the species shows that each sister species set is closely related, but within the sister sets, the species are phylogenetically indistinguishable

Onderwys in Afrika

Vergelykende opvoedkundige studie: By ’n onderwerp soos die onderhawige, waarin dit gaan oor die onderwys van ’n groot aantal geweste wat baie van mekaar verskil t.o.v. politiek, ekonomie, ras, maatskaplike toestande, ens., moet daar noodwendig op die terrein van die Vergelykende Opvoedkunde getree word wat vandag reeds vaste oogmerke en metodes van ondersoek ontwikkel het. Wil ons dus enigsins aanspraak maak op wetenskaplikheid met ons onderwerp, moet ons die prosedure wat algemeen in toepassing is ook hier gebruik

Systematics, diversity, and origins of upper cretaceous continental molluscan fauna in the infra- and intertrappean strata of the Deccan Plateau, central India

The Deccan Plateau in western and central India has been a major area of interest for researchers since the 1800s. In 1840, James Sowerby described the molluscan collection sent to him by John Malcolmson. In 1860, Stephen Hislop identified new molluscan species and redescribed based on better preserved material. Although this seminal work was comprehensive, interpretations have changed since the mid 1800s. Species need to be reassigned to current and/or accurate taxa, as well as revalidated statistically. Seventeen character traits were measured on over 600 specimens from five eastern Deccan Plateau localities representing a stratigraphic and temporal sequence. Cluster analysis was utilized to observe grouping patterns among specimens including Deccan type specimens and modern related species. Three new species (Lymnaea pokhariensis, Bellamya lattooformis, and Zootecus burji) and four new subspecies (Tricula conoidea conoidea, T. c. hislopi, Valvata unicarinifera unicarinifera, and V. u. chiknaformis) were identified and described. Three families with their associated genera and one genus (Viviparidae to Pomatiopsidae, Viviparidae to Subulinidae, Physidae to Planorbidae, and Viviparus to Bellamya) were revised to accommodate a more accurate taxonomic and biogeographic framework. Analysis of Variance (ANOVA) was employed to look at changes in morphology through the sequence and χ2 tests were used to observe changes in diversity and abundance. Overall, there is a dramatic decrease in species size with the onset of volcanism but morphology and diversity remain stable. Species abundance changes but the lack of pattern suggests it is not a result of the volcanism

Sp1 acetylation is associated with loss of DNA binding at promoters associated with cell cycle arrest and cell death in a colon cell line

Butyrate, a known histone deacetylase inhibitor (HDACi) and product of fibre fermentation, is postulated to mediate the protective effect of dietary fibre against colon cancer. The transcription factor Sp1 is a target of acetylation and is known to be associated with class I HDACs, including HDAC1. Sp1 is a ubiquitous transcription factor and Sp1-regulated genes include those involved in cell cycle regulation, apoptosis and lipogenesis: all major pathways in cancer development. The only known acetylated residue of Sp1 is lysine703 which resides in the DNA binding domain. Here we show that acetylated Sp1 loses p21- and bak-promoter -binding function in vitro. Furthermore treatment with a panel of HDAC inhibitors showed clustering of activities for a subset of inhibitors, causing G2 cell cycle arrest, Sp1 acetylation, p21 and Bak over-expression, all with very similar EC50 concentrations. These HDACi activities were not distributed according to the molecular class of compound. In order to mimic loss of binding, an siRNA strategy was used to reduce Sp1 expression. This resulted in altered expression of multiple elements of the p53/p21 pathway. Taken together our data suggest a mechanistic model for the chemopreventive actions of butyrate in colon epithelial cells, and provide new insight into the differential activities some classes of HDAC inhibitors

"I Am What I Am" Comparing the Experiences of Openly Gay and Lesbian PE Teachers with Non-specialist Peers in a Period of Declining Homohysteria

“I am what I am…”: comparing the experiences of openly gay and lesbian PE teachers with non-specialist peers in a period of declining homohysteria This presentation will highlight the initial findings of the project examining the experiences of 13 self-selecting gay and lesbian teachers in order to compare the experiences of those who teach PE and school sports with those who teach more classroom-based subject areas. Recent studies have focused on the complexities faced by openly gay and lesbian teachers in various countries (Ferfolja & Hopkins, 2013; Gray, 2013; Neary, 2012; Fahie, 2016; Connell, 2015). Additionally, studies have been carried out that focus specifically on physical education teachers (Sykes, 2009; Edwards et al., 2014) and music teachers (Palkki, 2015). However, as Edwards et al. (2014) acknowledge there is still a gap in research of teachers working in schools since the removal of Section 28, an act rushed through the UK parliament in a period of high homohysteria (Anderson, 2011; Moran, 2001). This Act has since been repealed and there has been a cultural shift, with homophobia steadily in decline according to GSS data (Anderson, 2011). This project seeks to identify how teachers navigate both homophobia and heteronormativity within an educational context; in addition, it explores perceptions of impact on learners in the classroom as a result of a school culture of openness. The presentation details the initial findings from the interviews carried out, providing a comparative account between the experiences of those who teach Physical Education (as a perceived area of professional vulnerability) and those who teach other curriculum areas

Gene doctoring: a method for recombineering in laboratory and pathogenic Escherichia coli strains

Background: Homologous recombination mediated by the lambda-Red genes is a common method for making chromosomal modifications in Escherichia coli. Several protocols have been developed that differ in the mechanisms by which DNA, carrying regions homologous to the chromosome, are delivered into the cell. A common technique is to electroporate linear DNA fragments into cells. Alternatively, DNA fragments are generated in vivo by digestion of a donor plasmid with a nuclease that does not cleave the host genome. In both cases the lambda-Red gene products recombine homologous regions carried on the linear DNA fragments with the chromosome. We have successfully used both techniques to generate chromosomal mutations in E. coli K-12 strains. However, we have had limited success with these lambda-Red based recombination techniques in pathogenic E. coli strains, which has led us to develop an enhanced protocol for recombineering in such strains. \ud \ud Results: Our goal was to develop a high-throughput recombineering system, primarily for the coupling of genes to epitope tags, which could also be used for deletion of genes in both pathogenic and K-12 E. coli strains. To that end we have designed a series of donor plasmids for use with the lambda-Red recombination system, which when cleaved in vivo by the I-SceI meganuclease generate a discrete linear DNA fragment, allowing for C-terminal tagging of chromosomal genes with a 6xHis, 3xFLAG, 4xProteinA or GFP tag or for the deletion of chromosomal regions. We have enhanced existing protocols and technologies by inclusion of a cassette conferring kanamycin resistance and, crucially, by including the sacB gene on the donor plasmid, so that all but true recombinants are counter-selected on kanamycin and sucrose containing media, thus eliminating the need for extensive screening. This method has the added advantage of limiting the exposure of cells to the potential damaging effects of the lambda-Red system, which can lead to unwanted secondary alterations to the chromosome. \ud \ud Conclusion: We have developed a counter-selective recombineering technique for epitope tagging or for deleting genes in E. coli. We have demonstrated the versatility of the technique by modifying the chromosome of the enterohaemorrhagic O157:H7 (EHEC), uropathogenic CFT073 (UPEC), enteroaggregative O42 (EAEC) and enterotoxigenic H10407 (ETEC) E. coli strains as well as in K-12 laboratory strains

An Overview of the Experiences of Openly Gay and Lesbian Teachers in a Period of Declining Homohysteria: Focus on Climate, Activism and Teaching Environment

This presentation will highlight the initial findings of a small-scale pilot project examining the experiences of 13 self-selecting gay and lesbian teachers working in Primary and Secondary schools in England. The project aimed to give voice to individuals’ lived experience as education practitioners identifying as “out” in the workplace, in order to counteract negative perceptions of hostility to disclosures of sexual orientation by teachers. As Edwards et al. (2014) acknowledge, there is still a gap in research of teachers working in schools since the removal of Section 28, an act rushed through the UK parliament in 1988 during a period of high homohysteria (Anderson, 2011; Moran, 2001). The repeal of the Act in 2003 led to a cultural shift, with homophobia steadily in decline according to GSS data (Anderson, 2011). This project seeks to identify how teachers navigate both homophobia and heteronormativity within an educational context; in addition, it explores perceptions of impact on learners in the classroom as a result of a school culture of openness. The presentation details the initial findings from the interviews carried out, providing a comparative account between the experiences of those who teach in the Primary and Secondary phases of contemporary UK education

Susceptibility of lung epithelium to neutrophil elastase: protection by native inhibitors

The development of emphysema is thought to be due to an imbalance of proteases (especially neutrophil elastase [NE]) and antiproteases with loosening of the respiratory epithelium as an early event. We investigated the effect of NE on respiratory epithelial cell adherence in vitro , in the presence of varying concentrations and combinations of native inhibitors, α-1-proteinase inhibitor (PI) and secretory leukoprotease inhibitor (SLPI). SLPI was two to 12 times more effective than PI at preventing the effects of NE, especially when enzyme:inhibitor ratios were almost equivalent. Even when the concentration of SLPI was only 10% of the total (as in normal peripheral lung secretions), it gave greater protection than PI alone. This suggests that SLPI plays an important role in controlling neutrophil elastaseinduced inflammation and tissue damage

"I Am What I Am" Comparing the Experiences of Openly Gay and Lesbian PE Teachers with Non-specialist Peers in a Period of Declining Homohysteria

“I am what I am…”: comparing the experiences of openly gay and lesbian PE teachers with non-specialist peers in a period of declining homohysteria This presentation will highlight the initial findings of the project examining the experiences of 13 self-selecting gay and lesbian teachers in order to compare the experiences of those who teach PE and school sports with those who teach more classroom-based subject areas. Recent studies have focused on the complexities faced by openly gay and lesbian teachers in various countries (Ferfolja & Hopkins, 2013; Gray, 2013; Neary, 2012; Fahie, 2016; Connell, 2015). Additionally, studies have been carried out that focus specifically on physical education teachers (Sykes, 2009; Edwards et al., 2014) and music teachers (Palkki, 2015). However, as Edwards et al. (2014) acknowledge there is still a gap in research of teachers working in schools since the removal of Section 28, an act rushed through the UK parliament in a period of high homohysteria (Anderson, 2011; Moran, 2001). This Act has since been repealed and there has been a cultural shift, with homophobia steadily in decline according to GSS data (Anderson, 2011). This project seeks to identify how teachers navigate both homophobia and heteronormativity within an educational context; in addition, it explores perceptions of impact on learners in the classroom as a result of a school culture of openness. The presentation details the initial findings from the interviews carried out, providing a comparative account between the experiences of those who teach Physical Education (as a perceived area of professional vulnerability) and those who teach other curriculum areas