Thermodynamic aspects of materials' hardness: prediction of novel superhard high-pressure phases

In the present work we have proposed the method that allows one to easily estimate hardness and bulk modulus of known or hypothetical solid phases from the data on Gibbs energy of atomization of the elements and corresponding covalent radii. It has been shown that hardness and bulk moduli of compounds strongly correlate with their thermodynamic and structural properties. The proposed method may be used for a large number of compounds with various types of chemical bonding and structures; moreover, the temperature dependence of hardness may be calculated, that has been performed for diamond and cubic boron nitride. The correctness of this approach has been shown for the recently synthesized superhard diamond-like BC5. It has been predicted that the hypothetical forms of B2O3, diamond-like boron, BCx and COx, which could be synthesized at high pressures and temperatures, should have extreme hardness

Expanding, axisymmetric pure-radiation gravitational fields with a simple twist

New expanding, axisymmetric pure-radiation solutions are found, exploiting the analogy with the Euler-Darboux equation for aligned colliding plane waves.Comment: revtex, 5 page

Large emergency-response exercises: qualitative characteristics - a survey

Exercises, drills, or simulations are widely used, by governments, agencies and commercial organizations, to simulate serious incidents and train staff how to respond to them. International cooperation has led to increasingly large-scale exercises, often involving hundreds or even thousands of participants in many locations. The difference between ‘large’ and ‘small’ exercises is more than one of size: (a) Large exercises are more ‘experiential’ and more likely to undermine any model of reality that single organizations may create; (b) they create a ‘play space’ in which organizations and individuals act out their own needs and identifications, and a ritual with strong social implications; (c) group-analytic psychotherapy suggests that the emotions aroused in a large group may be stronger and more difficult to control. Feelings are an unacknowledged major factor in the success or failure of exercises; (d) successful large exercises help improve the nature of trust between individuals and the organizations they represent, changing it from a situational trust to a personal trust; (e) it is more difficult to learn from large exercises or to apply the lessons identified; (f) however, large exercises can help develop organizations and individuals. Exercises (and simulation in general) need to be approached from a broader multidisciplinary direction if their full potential is to be realized

Pre-columbian origins for North American anthrax

Disease introduction into the New World during colonial expansion is well documented and had a major impact on indigenous populations; however, few diseases have been associated with early human migrations into North America. During the late Pleistocene epoch, Asia and North America were joined by the Beringian Steppe ecosystem which allowed animals and humans to freely cross what would become a water barrier in the Holocene. Anthrax has clearly been shown to be dispersed by human commerce and trade in animal products contaminated with Bacillus anthracis spores. Humans appear to have brought B. anthracis to this area from Asia and then moved it further south as an ice-free corridor opened in central Canada ~13,000 ybp. In this study, we have defined the evolutionary history of Western North American (WNA) anthrax using 2,850 single nucleotide polymorphisms (SNPs) and 285 geographically diverse B. anthracis isolates. Phylogeography of the major WNA B. anthracis clone reveals ancestral populations in northern Canada with progressively derived populations to the south; the most recent ancestor of this clonal lineage is in Eurasia. Our phylogeographic patterns are consistent with B. anthracis arriving with humans via the Bering Land Bridge. This northern-origin hypothesis is highly consistent with our phylogeographic patterns and rates of SNP accumulation observed in current day B. anthracis isolates. Continent-wide dispersal of WNA B. anthracis likely required movement by later European colonizers, but the continent's first inhabitants may have seeded the initial North American populations

Chronic testicular Chlamydia muridarum infection impairs mouse fertility and offspring development

With approximately 131 million new genital tract infections occurring each year, Chlamydia is the most common sexually transmitted bacterial pathogen worldwide. Male and female infections occur at similar rates and both cause serious pathological sequelae. Despite this, the impact of chlamydial infection on male fertility has long been debated, and the effects of paternal chlamydial infection on offspring development are unknown. Using a male mouse chronic infection model, we show that chlamydial infection persists in the testes, adversely affecting the testicular environment. Infection increased leukocyte infiltration, disrupted the blood:testis barrier and reduced spermiogenic cell numbers and seminiferous tubule volume. Sperm from infected mice had decreased motility, increased abnormal morphology, decreased zona-binding capacity, and increased DNA damage. Serum anti-sperm antibodies were also increased. When both acutely and chronically infected male mice were bred with healthy female mice, 16.7% of pups displayed developmental abnormalities. Female offspring of chronically infected sires had smaller reproductive tracts than offspring of noninfected sires. The male pups of infected sires displayed delayed testicular development, with abnormalities in sperm vitality, motility, and sperm-oocyte binding evident at sexual maturity. These data suggest that chronic testicular Chlamydia infection can contribute to male infertility, which may have an intergenerational impact on sperm quality

Cross-sectional survey of a sample of UK primary care dental professionals' experiences of sharps injuries and perception of access to occupational health support

Background: The 2013 Sharps Regulations were introduced to minimise the risk of sharps injuries and blood borne virus transmission throughout healthcare. Occupational health (OH) services are pivotal for helping employers implement these regulations. Despite this, no research has been conducted on the prevalence of sharps injuries, underreporting of injuries or access to OH among primary care dental professionals in the UK since 2013. Aim: To estimate the prevalence of sharps injuries, the level of underreporting and of self-reported access to an OH service both for the care of sharps injuries and for general health and wellbeing. Method: A cross-sectional survey was administered at the 2017 British Dental Association (BDA) Conference and Exhibition in Manchester, and at the 2017 BDA Scottish Conference and Exhibition in Glasgow. The survey covered questions relating to sharps injuries and OH support. Statistical analyses were conducted using SPSS Version 22 (IBM Corp., 2013). Results: A total of 796 delegates participated, of whom 166 (20.8%) had experienced a sharps injury in the past year and 58 (35%) did not report the incident. Of the participants, 190 (23.9%) reported no, or uncertain, access to OH support. Most respondents' practices had a sharps safety policy (771; 96.9%), but fewer (611; 76.8%) had received training on the prevention of sharps injuries and neither policy nor training were associated with incident reporting. Conclusion: Despite the introduction of the sharps regulations, sharps injuries and underreporting of injuries remain prevalent among those practising in primary dental care. Our results also suggest that there are significant shortfalls in OH support, at a time when changes to guidance on health clearance and management of BBV infected healthcare workers, in addition to sharps injury management, increase the need for such services

Identification of Hypoxia-Regulated Proteins Using MALDI-Mass Spectrometry Imaging Combined with Quantitative Proteomics

Hypoxia is present in most solid tumors and is clinically correlated with increased metastasis and poor patient survival. While studies have demonstrated the role of hypoxia and hypoxia-regulated proteins in cancer progression, no attempts have been made to identify hypoxia-regulated proteins using quantitative proteomics combined with MALDI-mass spectrometry imaging (MALDI-MSI). Here we present a comprehensive hypoxic proteome study and are the first to investigate changes in situ using tumor samples. In vitro quantitative mass spectrometry analysis of the hypoxic proteome was performed on breast cancer cells using stable isotope labeling with amino acids in cell culture (SILAC). MS analyses were performed on laser-capture microdissected samples isolated from normoxic and hypoxic regions from tumors derived from the same cells used in vitro. MALDI-MSI was used in combination to investigate hypoxia-regulated protein localization within tumor sections. Here we identified more than 100 proteins, both novel and previously reported, that were associated with hypoxia. Several proteins were localized in hypoxic regions, as identified by MALDI-MSI. Visualization and data extrapolation methods for the in vitro SILAC data were also developed, and computational mapping of MALDI-MSI data to IHC results was applied for data validation. The results and limitations of the methodologies described are discussed. 2014 American Chemical Societ

Multivariate analyses for biomarkers hunting and validation through on-tissue bottom-up or in-source decay in MALDI-MSI: application to prostate cancer.

peer reviewe

An exploratory study of the relationship between parental attitudes and behaviour and young people's consumption of alcohol

Background Concern is growing regarding frequent and excessive misuse of alcohol by young people. The average age at which young people in Europe start to drink is twelve and a half, and during the last decade, the quantity of alcohol consumed by younger adolescents in the UK has increased. Families are known to play an important role in shaping young people's alcohol misuse, although family risk and protective factors associated with misuse in a UK context are in need of further investigation. Methods The study used a cross-sectional design, involving secondary analyses of self-completion questionnaire responses from 6,628 secondary school children (i.e. aged 11-16 years), from 12 schools within an urban location in Wales. Items relating to family functioning and perceived parental attitudes were first subjected to factor analysis. Associations of family closeness and conflict, parental monitoring and attitudes and family history of substance misuse with children's self reported alcohol consumption were examined using logistic regression analyses. Results Approximately three quarters of respondents reported having tried alcohol, most of whom had first tried alcohol aged 12 or under. Parental monitoring and family closeness were positively correlated with one another and were both associated with significantly lower levels of drinking behaviours. Family violence and conflict, more liberal parental attitudes towards substance use and towards alcohol and petty crime, and family history of substance misuse were positively correlated with one another and with higher levels of drinking behaviours. Parental monitoring was identified as the family functioning factor most consistently associated with drinking behaviour in multivariate analyses. Conclusions Significant relationships were found between young people's drinking behaviours and perceptions of risk and protective factors in the family environment. Parental monitoring was strongly associated with family closeness and appeared to form one part of a parenting style of more general communication and regulation of children's behaviour. Findings support the need for alcohol misuse prevention interventions which address risk and protective factors within the family setting. Timing of such prevention work should be related both to the development of family relationships and the age at which young people begin drinking alcohol