Selected Problems of Determining Critical Loads in Sructures with Stable Post-Critical Behaviour.

This paper presents selected cases of inapplicability of theory based methods of determining critical loads in thin – walled, composite tubes. 8th layered composite tubes with square cross-section were being subjected to static compression and in order to register experimental data two measuring equipment were employed: strain-gauges and Digital Image Correlation system ARAMIS R ⃝ . When measurement data were collected five different theory based methods were applied in order to determine critical loads. Cases where it was impossible to apply certain methods or some doubts about correctness of the results occurred were presented and analyzed. Moreover in cases where it was possible, the theory was equivalently transformed, in such a way to fit experimental data and calculate the critical loads

Experimental investigations of thin walled, squared cross – section composite tubes applied to static compression.

This paper deals with the experimental investigations of thin-walled, squared crosssection composite tubes subjected to a static compression. The main purpose of this paper is to present and discuss different methods of data analysis while investigating stability of thin-walled structures. Performed experiments were conducted by employing Zwick/Roel universal test stand; non-contact, geometrical - optical principled system Aramis produced by GOM company and strain-gauge technique. Different methods of determining buckling loads were employed, discussed and compared. Moreover all problems, occurring during experiments and data analysis were emphasized in order to show what kind of difficulties could appear during processing the results of measurements. As an example, comparing non-dimensional strain-gauges data with dimensional non-contact system Aramis results of measurements can quoted

α-Synuclein induced cell death in mouse hippocampal (HT22) cells is mediated by nitric oxide-dependent activation of caspase-3

AbstractOur previous studies indicated that exogenous α-synuclein (ASN) activates neuronal nitric oxide (NO) synthase (nNOS) in rat brain slices. The present study, carried out on immortalized hippocampal neuronal cells (HT22), was designed to extend the previous results by showing the molecular pathway of NO-mediated cell death induced by exogenous ASN. Extracellular ASN (10μM) was found to stimulate nitric oxide synthase (NOS) and increase caspase-3 activity in HT22 cells, leading to poly(ADP-ribose) polymerase (PARP-1) cleavage. The inhibitor of Ca2+-dependent NOS (N-nitro-l-arginine, 100μM) prevented ASN-evoked caspase-3 activation and PARP-1 degradation. ASN exposure resulted in apoptotic death of HT22 cells and this effect was reversed by inhibition of NO synthesis and caspase-3 activity. Our results demonstrated that extracellular ASN induces neuronal cell death by NO-mediated caspase-3 activation

Geminate recombination of hydroxyl radicals generated in 200 nm photodissociation of aqueous hydrogen peroxide

The picosecond dynamics of hydroxyl radicals generated in 200 nm photoinduced dissociation of aqueous hydrogen peroxide have been observed through their transient absorbance at 266 nm. It is shown that these kinetics are nearly exponential, with a decay time of ca. 30 ps. The prompt quantum yield for the decomposition of H2O2 is 0.56, and the fraction of hydroxyl radicals escaping from the solvent cage to the water bulk is 64-68%. These recombination kinetics suggest strong caging of the geminate hydroxyl radicals by water. Phenomenologically, these kinetics may be rationalized in terms of the diffusion of hydroxide radicals out of a shallow potential well (a solvent cage) with an Onsager radius of 0.24 nm.Comment: 14 pages, 1 figur

Defensive system of ancient city Volubilis. State of research and new perspectives

This contribution presents the first results of two surveys (2014, 2016) in the vicinity of the ancient city of Volubilis, situated in the southern part of the Roman province Mauretania Tingitana. The main purpose was to assess the possibilities of non-invasive research of the forts established by the Romans as part of the defensive system of Volubilis and to investigate the character of the Roman defences on the southern border. Forts were connected with watchtowers which completed the system protecting the territory in question. Many interesting fragments of pottery have been found at those sites, which may confirm Roman presence in many, though not all points. Collected field information as well as the analysis of publications leads to the conclusion that the border defence arrangements at Volubilis might not be considered as a part of a centrally organised limes system, safe guarding the entire province, but as the defensive system of the city and its surroundings.This contribution presents the first results of two surveys (2014, 2016) in the vicinity of the ancient city of Volubilis, situated in the southern part of the Roman province Mauretania Tingitana. The main purpose was to assess the possibilities of non-invasive research of the forts established by the Romans as part of the defensive system of Volubilis and to investigate the character of the Roman defences on the southern border. Forts were connected with watchtowers which completed the system protecting the territory in question. Many interesting fragments of pottery have been found at those sites, which may confirm Roman presence in many, though not all points. Collected field information as well as the analysis of publications leads to the conclusion that the border defence arrangements at Volubilis might not be considered as a part of a centrally organised limes system, safe guarding the entire province, but as the defensive system of the city and its surroundings

Determination of the Expression Patterns of the Nine CSP Genes in Escherichia coli K-12 MG1655 and the Growth Defects Associated with Deletion of These Genes

Cold-shock proteins (CSPs) are a family of small nucleic acid-binding proteins. In Escherichia coli K-12, there are 9 homologous csp genes named A-I. Aside from microarray studies, transcript levels from all nine csp genes have never been assayed using the same technique. The objectives of this study were to determine when these genes are expressed, if homologous pairs are expressed the same, how many are cold-shock inducible, and if there is a ranking of importance for these genes. To answer these questions, I determined csp mRNA expression patterns for all nine csp genes during normal growth at 37°C, and after cold-shock, using quantitative real-time PCR. To uncover functional redundancies, deletion mutants were analyzed for their colony-forming ability after cold-shock, and after exposure to the chromosome decondensing agent, camphor. The results show that mRNA levels for each csp gene change with growth phase, and growth rate, and that homologous pairs are not expressed the same. The six most highly expressed csp genes in E. coli K-12 at 37°C are cspA, -B, -C, -E, -G, and -I. Transcription of cspA, -B, -G, and -I was induced after a shift to 15°C in defined minimal medium. Of the six quintuple csp deletion mutants that were created, one shows the most severe macroscopic phenotypes (TC155, cspABCEG). TC155 is cold-sensitive, and camphor-sensitive on both defined rich and defined minimal agar and only overexpression of CspC, CspE, CspG, or CspI can rescue the growth of this mutant. Taken together, these results indicate that there is some functional redundancy among the nine CSPs in E. coli K-12, but there is also a ranking of importance for these proteins in the cell

A systematic review of strategies to recruit and retain primary care doctors

Background There is a workforce crisis in primary care. Previous research has looked at the reasons underlying recruitment and retention problems, but little research has looked at what works to improve recruitment and retention. The aim of this systematic review is to evaluate interventions and strategies used to recruit and retain primary care doctors internationally. Methods A systematic review was undertaken. MEDLINE, EMBASE, CENTRAL and grey literature were searched from inception to January 2015.Articles assessing interventions aimed at recruiting or retaining doctors in high income countries, applicable to primary care doctors were included. No restrictions on language or year of publication. The first author screened all titles and abstracts and a second author screened 20%. Data extraction was carried out by one author and checked by a second. Meta-analysis was not possible due to heterogeneity. Results 51 studies assessing 42 interventions were retrieved. Interventions were categorised into thirteen groups: financial incentives (n=11), recruiting rural students (n=6), international recruitment (n=4), rural or primary care focused undergraduate placements (n=3), rural or underserved postgraduate training (n=3), well-being or peer support initiatives (n=3), marketing (n=2), mixed interventions (n=5), support for professional development or research (n=5), retainer schemes (n=4), re-entry schemes (n=1), specialised recruiters or case managers (n=2) and delayed partnerships (n=2). Studies were of low methodological quality with no RCTs and only 15 studies with a comparison group. Weak evidence supported the use of postgraduate placements in underserved areas, undergraduate rural placements and recruiting students to medical school from rural areas. There was mixed evidence about financial incentives. A marketing campaign was associated with lower recruitment. Conclusions This is the first systematic review of interventions to improve recruitment and retention of primary care doctors. Although the evidence base for recruiting and care doctors is weak and more high quality research is needed, this review found evidence to support undergraduate and postgraduate placements in underserved areas, and selective recruitment of medical students. Other initiatives covered may have potential to improve recruitment and retention of primary care practitioners, but their effectiveness has not been established