Mechanical Compression Behaviour of "Green" Rocket Propellants

The issues related to mechanical resistance of solid rocket propellants, which can appear during storage or handling of the launching system, are considered to directly influence the burning performance. Thus, in this study, four new types of composite rocket propellants, based on an environmentally friendly oxidizer (phase-stabilized ammonium nitrate), a metallic fuel (aluminium), and a "green" polyurethane-based binder (synthesized from an oligomeric isocyanate and a blend of polyester-polyols obtained through the catalytic degradation of polyethylene terephthalate), were subjected to compression mechanical analysis in order to highlight the importance of the binder on the response given by the tested materials subjected to compressive loads. The samples showed remarkable mechanical performances, the experiments allowing us also to determine the influence of the binder composition and fuel granulation on mechanical properties of the composite propellant

Source attribution, prevalence and enumeration of Campylobacter spp. from retail liver

Funding Information: We thank Food Standards Agency, Scotland for funding this work.Peer reviewedPreprin

Intradiploic epidermoid cyst of the skull: Case report

Authors describe a giant intradiploic epidermoid cyst of the cranial vault with massive intra- and extracranial extension and analyze the clinicopathological, imaging features and treatment of these lesions in the light of the most important published data. A 38-years old male patient with a history of chronic headache reported a painless subcutaneous swelling 4 months ago on the right frontoparietal scalp. CT and MRI evaluation revealed a large well-defined extracerebral mass in the frontoparietal scalp with destruction of both the inner and outer tables of the bone. The patient underwent a total microsurgical resection of the tumor and the cranial defect produced by the resection of the space-occupaying lesion was repaired with titanium wire mesh and methyl methacrylate cranioplasty. The histological examination has shown a cystic structure lined by squamous epithelium and containing laminated keratin material, aspects that are suggesting a epidermoid cyst. The patient post-operative course was uneventful, without any neurological deficit and was discharged after 48 hours of hospitalisation in a good medical condition. The review of the literature shows that the parietal bone location for intradiploic epidermoid tumors in rare. Complete surgical resection represent the gold standard of treatment, and no adjuvant therapy is needed. Recent advances in diagnostic imaging and treatment of these lesions are reviewed.&nbsp

Evolution of an Agriculture-Associated Disease Causing Campylobacter coli Clade: Evidence from National Surveillance Data in Scotland

The common zoonotic pathogen Campylobacter coli is an important cause of bacterial gastroenteritis worldwide but its evolution is incompletely understood. Using multilocus sequence type (MLST) data of 7 housekeeping genes from a national survey of Campylobacter in Scotland (2005/6), and a combined population genetic-phylogenetics approach, we investigated the evolutionary history of C. coli. Genealogical reconstruction of isolates from clinical infection, farm animals and the environment, revealed a three-clade genetic structure. The majority of farm animal, and all disease causing genotypes belonged to a single clade (clade 1) which had comparatively low synonymous sequence diversity, little deep branching genetic structure, and a higher number of shared alleles providing evidence of recent clonal decent. Calibration of the rate of molecular evolution, based on within-species genetic variation, estimated a more rapid rate of evolution than in traditional estimates. This placed the divergence of the clades at less than 2500 years ago, consistent with the introduction of an agricultural niche having had an effect upon the evolution of the C. coli clades. Attribution of clinical isolate genotypes to source, using an asymmetric island model, confirmed that strains from chicken and ruminants, and not pigs or turkeys, are the principal source of human C. coli infection. Taken together these analyses are consistent with an evolutionary scenario describing the emergence of agriculture-associated C. coli lineage that is an important human pathogen

Elucidating the aetiology of human Campylobacter coli infections

Peer reviewedPublisher PD

Childbearing intentions in a low fertility context: the case of Romania

This paper applies the Theory of Planned Behaviour (TPB) to find out the predictors of fertility intentions in Romania, a low-fertility country. We analyse how attitudes, subjective norms and perceived behavioural control relate to the intention to have a child among childless individuals and one-child parents. Principal axis factor analysis confirms which items proposed by the Generation and Gender Survey (GGS 2005) act as valid and reliable measures of the suggested theoretical socio-psychological factors. Four parity-specific logistic regression models are applied to evaluate the relationship between the socio-psychological factors and childbearing intentions. Social pressure emerges as the most important aspect in fertility decision-making among childless individuals and one-child parents, and positive attitudes towards childbearing are a strong component in planning for a child. This paper also underlines the importance of the region-specific factors when studying childbearing intentions: planning for the second child significantly differs among the development regions, representing the cultural and socio-economic divisions of the Romanian territory

Le taux de fécondité totale dans le mariage et ses extensions

What we will call the age-based TMFR is computed conventionally by adding up age-specific marital fertility rates in the hope of estimating the number of children ever born to a woman who is married throughout her childbearing years. Demographers have long been strongly skeptical about this quantity because it normally indicates implausibly many children. Our analysis of data from the Romanian GGS confirms this finding, and we propose an alternative duration-based TMFR computed in the spirit of parity-progression ratios. At the same time, we extend the method to cover any type of living arrangement (cohabitation, marriage, non-partnered arrangement, and so on). Because each resulting total union-type fertility rate (TUFR) explicitly accounts for the living arrangement, it improves on the conventional total fertility rate (TFR), which does not. We embed the investigation in an event-history analysis with fixed and time-varying control covariates and find patterns of relative risks for such variables that reveal interesting features of childbearing behavior in the Romanian data, which we use to illustrate the method. In most cases, these patterns are quite robust against model re-specification, including the shift from the age-based to the duration-based approach. Since, the number of female respondents is “only” about 6,000 (minus records that cannot be used for the current purpose) in a normal single-round GGS, there is considerable inherent random variation in the data set, but we show that simple few-term moving average graduation suffices to overcome this problem.Le taux de fécondité totale en mariage (TFTM) selon l’âge est calculé par convention en sommant les taux de fécondité par âge dans le mariage en vue d’obtenir une estimation du nombre total d’enfants nés d’une femme qui aurait été mariée tout au long de sa vie reproductive. Depuis longtemps les démographes considèrent cette mesure avec scepticisme car elle aboutit souvent à un nombre total d’enfants beaucoup trop élevé. Notre analyse des données du EGG roumain confirme cette constatation et nous proposons dès lors, comme alternative, un TFTM selon la durée, dans l’esprit des probabilités d’agrandissement des familles. Par ailleurs, nous étendons la méthode à tous types de situation de couple (cohabitation, mariage, sans partenaire, etc.). Comme le taux de fécondité totale selon le type d’union (TFTU) tient compte explicitement de la situation de couple, il doit être préféré au TFTM qui ne tient pas compte de ce critère. Notre étude est conduite dans le cadre d’une analyse biographique tenant compte de covariables fixes ou dépendantes du temps. Les résultats de l’analyse nous permettent de découvrir des caractéristiques intéressantes de la fécondité roumaine, que nous utilisons pour illustrer la méthode. Dans la plupart des cas, ces caractéristiques sont robustes face à une re-spécification du modèle, notamment le passage de l’approche basée sur l’âge à l’approche tenant compte de la durée. Comme le nombre de répondants à l’enquête EGG à un passage n’est ‘que’ de l’ordre de 6000 (moins les cas qui n’ont pas pu être utilisés pour le présent travail), il existe une fluctuation aléatoire importante dans les données. Nous montrons toutefois qu’un lissage par moyenne mobile à quelques termes seulement nous permet de surmonter cette difficulté

Climate, human behaviour or environment: individual-based modelling of Campylobacter seasonality and strategies to reduce disease burden

Acknowledgements: We thank colleagues within the Modelling, Evidence and Policy Research Group for useful feedback on this manuscript. Competing interests: The authors declare that they have no competing interests. Availability of data and materials: The R code used in this research is available at https://gitlab.com/rasanderson/campylobacter-microsimulation; it is platform independent, R version 3.3.0 and above. Funding: This research was funded by Medical Research Council Grant, Natural Environment Research Council, Economic and Social Research Council, Biotechnology and Biological Sciences Research Council, and the Food Standards Agency through the Environmental and Social Ecology of Human Infectious Diseases Initiative (Sources, seasonality, transmission and control: Campylobacter and human behaviour in a changing environment (ENIGMA); Grant Reference G1100799-1). PRH, SJO’B, and IRL are funded in part by the NIHR Health Protection Research Unit in Gastrointestinal Infection, at the University of Liverpool. PRH and IRL are also funded in part by the NIHR Health Protection Research Unit in Emergency Preparedness and Response, at King’s College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, the Department of Health or Public Health England.Peer reviewedPublisher PD