Reconstruction subgrid models for nonpremixed combustion

Large-eddy simulation of combustion problems involves highly nonlinear terms that, when filtered, result in a contribution from subgrid fluctuations of scalars, Z, to the dynamics of the filtered value. This subgrid contribution requires modeling. Reconstruction models try to recover as much information as possible from the resolved field Z, based on a deconvolution procedure to obtain an intermediate field ZM. The approximate reconstruction using moments (ARM) method combines approximate reconstruction, a purely mathematical procedure, with additional physics-based information required to match specific scalar moments, in the simplest case, the Reynolds-averaged value of the subgrid variance. Here, results from the analysis of the ARM model in the case of a spatially evolving turbulent plane jet are presented. A priori and a posteriori evaluations using data from direct numerical simulation are carried out. The nonlinearities considered are representative of reacting flows: power functions, the dependence of the density on the mixture fraction (relevant for conserved scalar approaches) and the Arrhenius nonlinearity (very localized in Z space). Comparisons are made against the more popular beta probability density function (PDF) approach in the a priori analysis, trying to define ranges of validity for each approach. The results show that the ARM model is able to capture the subgrid part of the variance accurately over a wide range of filter sizes and performs well for the different nonlinearities, giving uniformly better predictions than the beta PDF for the polynomial case. In the case of the density and Arrhenius nonlinearities, the relative performance of the ARM and traditional PDF approaches depends on the size of the subgrid variance with respect to a characteristic scale of each function. Furthermore, the sources of error associated with the ARM method are considered and analytical bounds on that error are obtained

Synthetic cathinones related fatalities: an update

Synthetic cathinones, more commonly known as "bath salts", are synthetic drugs chemically related to cathinone, a psychostimulant found in the khat plant. They are the first most consumed products among new psychoactive substances, which cause psychostimulant and hallucinogenic effects determining a number of fatalities worldwide.  In this paper, we have systematically reviewed cases of synthetic cathinones-related fatalities analytically confirmed, which have occurred in the last few years.OBJECTIVE: Synthetic cathinones, more commonly known as “bath salts”, are synthetic drugs chemically related to cathinone, a psychostimulant found in the khat plant. They are the first most consumed products among new psychoactive substances, which cause psychostimulant and hallucinogenic effects determining a number of fatalities worldwide. In this paper, we have systematically reviewed cases of synthetic cathinones-related fatalities analytically confirmed, which have occurred in the last few years. MATERIALS AND METHODS: Relevant scientific articles were identified in Medline, Cochrane Central, Scopus, Web of Science and Institutional/ government websites up to November 2017 using the following keywords: synthetic cathinones, mephedrone, methylenedioxypyrovalerone, MDPV, methylone, ethylone, buthylone, fatal intoxication, fatalities and death. RESULTS: In total, 20 citations met the criteria for inclusion, representing several fatal cases with analytically confirmed synthetic cathinones in biological sample/s of the deceased. The death was attributed to hyperthermia, hypertension, cardiac arrest and more in general to the classic serotonin syndrome. Only rarely did the concentration of the parent drug causing fatality overcome the value of 1 mg/L in post-mortem biological fluids. CONCLUSIONS: Abuse of synthetic cathinones still represents a serious public health issue. Systematic clinical studies on both the animal and human model are lacking; therefore, the only available data are from the users who experience the possible hazardous consequences. Analytical methodologies for the identification of parent compounds and eventual metabolites both in ante-mortem and post-mortem cases need to be developed and validated. Analytical data should be shared through different communication platforms with the aim of stopping this serious health threat for drug users

An electrical model for the Korteweg-de Vries equation

In this paper we describe an electrical network, whose current evolution does agree with a Korteweg\u2013de Vries equation. Our aim is to prepare pupils to understand the analytical aspects of nonlinear and dispersive phenomena, which very often are neglected in high-school and graduate textbooks. Some historical remarks introduce the topic and a bibliography is provided. \ua9 1984, American Association of Physics Teachers

Cerebral hemodynamics on MR perfusion images before and after bypass surgery in patients with giant intracranial aneurysms

Preoperative assessment of the anatomy and dynamics of cerebral circulation for patients with giant intracranial aneurysm can improve both outcome prediction and therapeutic approach. The aim of our study was to use perfusion MR imaging to evaluate cerebral hemodynamics in such patients before and after extraintracranial high-flow bypass surgery. METHODS: Five patients with a giant aneurysm of the intracranial internal carotid artery underwent MR studies before, 1 week after, and 1 month after high-flow bypass surgery. We performed MR and digital subtraction angiography, and conventional and functional MR sequences (diffusion and perfusion). Surgery consisted of middle cerebral artery (MCA)-internal carotid artery bypass with saphenous vein grafts (n = 4) or MCA-external carotid artery bypass (n = 1). RESULTS: In four patients, MR perfusion study showed impaired hemodynamics in the vascular territory supplied by the MCA of the aneurysm side, characterized by significantly reduced mean cerebral blood flow (CBF), whereas mean transit time (MTT) and regional cerebral blood volume (rCBV) were either preserved, reduced, or increased. After surgery, angiography showed good canalization of the bypass graft. MR perfusion data obtained after surgery showed improved cerebral hemodynamics in all cases, with a return of CBF index (CBFi), MTT, and rCBV to nearly normal values. CONCLUSION: Increased MTT with increased or preserved rCBV can be interpreted as a compensatory vasodilatory response to reduced perfusion pressure, presumably from compression and disturbed flow in the giant aneurysmal sac. When maximal vasodilation has occurred, however, the brain can no longer compensate for diminished perfusion by vasodilation, and rCBV and CBFi diminish. Bypass surgery improves hemodynamics, increasing perfusion pressure and, thus, CBFi. Perfusion MR imaging can be used to evaluate cerebral hemodynamics in patients with intracranial giant aneurysm.BACKGROUND AND PURPOSE: Preoperative assessment of the anatomy and dynamics of cerebral circulation for patients with giant intracranial aneurysm can improve both outcome prediction and therapeutic approach. The aim of our study was to use perfusion MR imaging to evaluate cerebral hemodynamics in such patients before and after extraintracranial high-flow bypass surgery. METHODS: Five patients with a giant aneurysm of the intracranial internal carotid artery underwent MR studies before, 1 week after, and 1 month after high-flow bypass surgery. We performed MR and digital subtraction angiography, and conventional and functional MR sequences (diffusion and perfusion). Surgery consisted of middle cerebral artery (MCA)-internal carotid artery bypass with saphenous vein grafts (n = 4) or MCA-external carotid artery bypass (n = 1). RESULTS: In four patients, MR perfusion study showed impaired hemodynamics in the vascular territory supplied by the MCA of the aneurysm side, characterized by significantly reduced mean cerebral blood flow (CBF), whereas mean transit time (MTT) and regional cerebral blood volume (rCBV) were either preserved, reduced, or increased. After surgery, angiography showed good canalization of the bypass graft. MR perfusion data obtained after surgery showed improved cerebral hemodynamics in all cases, with a return of CBF index (CBFi), MTT, and rCBV to nearly normal values. CONCLUSION: Increased MTT with increased or preserved rCBV can be interpreted as a compensatory vasodilatory response to reduced perfusion pressure, presumably from compression and disturbed flow in the giant aneurysmal sac. When maximal vasodilation has occurred, however, the brain can no longer compensate for diminished perfusion by vasodilation, and rCBV and CBFi diminish. Bypass surgery improves hemodynamics, increasing perfusion pressure and, thus, CBFi. Perfusion MR imaging can be used to evaluate cerebral hemodynamics in patients with intracranial giant aneurysm

Hepatotoxicity induced by greater celandine (Chelidonium majus L.): a review of the literature

The available literature assessing Chelidonium majus L. (CM) hepatotoxicity potential, and its risk to benefit assessment has been reviewed in this paper. Identification of significant scientific literature was performed via the following research databases: Cochrane Central, Google Scholar, EMBASE, Medline, Science Direct, Scopus, Web of Science, using the following keywords: "Chelidonium majus", "greater celandine", "Hepatotoxicity", "Liver" "Injury", "Toxicity" individually investigated and then again in association. CM named also greater celandine, swallow-wort, or bai-qu-cai (Chinese), has been used for a long time in traditional Chinese medicine and phytotherapy. Its extracts have been claimed to display a wide variety of biological activities: antimicrobial, anti-inflammatory, spasmolytic, antineoplastic, hepatoprotective, and analgesic. Moreover, herbal medicine suggests this plant have numerous additional effects which have not yet been scientifically evaluated, such as antitussive, diuretic, and eye-regenerative. However, despite its claimed hepatoprotective effects, several hepatotoxicity cases have been reported to be probably or highly probably connected with CM exposure, after their evaluation through liver-targeted causality assessment methods. CM hepatotoxicity has been defined as a distinct form of herb-induced liver injury (HILI), due to an idiosyncratic reaction of the metabolic type. This evidence has to be considered in relationship with the absence of considerable benefits of CM therapy. Therefore, the risk to benefit ratio of the use of herbal products containing greater celandine can actually be considered as negative

Regulatory framework of pharmaceutical compounding and actual developments of legislation in Europe

Pharmaceutical preparations are medicines that the pharmacist makes for the special needs of the patients that the pharmaceutical industry cannot comply for economic and logistic reasons. Pharmacy compounding is still an important component of pharmacy practice and a valuable therapeutical service that is an integrant part of the modern health care system, but its legislation is not harmonized among European and US countries.In 2011 the Committee of Ministers of the Council of Europe has adopted a Resolution on quality and safety assurance requirements for medicinal products prepared in pharmacies for the special needs of patients. Aim of this resolution is to harmonize quality assurance and standards for pharmacy-made medicinal products among European countries and to pass the gap in quality assurance and standards between preparation in pharmacies and medicines prepared by the pharmaceutical industry. This article will analyze the actual rules and technical norms that regulate compounding activity and the expectations resultants from the new European and US laws

Co-Creating Brand Image and Reputation through higher Education Internal-Stakeholder's Social Network

By drawing on social identity and stakeholders’ theories, this paper seeks to examine how universities co-create and manage their brand image and brand reputation through tapping into internal-stakeholders’ social network. This research utilises explanatory research design at the preliminary stage, and the subsequent model is examined via a positivist survey carried out among higher education internal stakeholders in the UK. The results show that the relationship between navigation design of the website, usability of the website and customization of the website are not significant from students’ perspective, whereas all those are significant from employees’ perspective. Furthermore, the relationship between logo and co-creation behaviour is not significant from employees’ perspective while it is significant from students’ perspective. University website is the most important marketing tool to attract students and other stakeholders. Therefore, these findings have significant implications for higher education branding and marketing managers aiming to design appropriate communication tools with a view to actively engage students and employees in a co-creation process to improve their products, services and brand image

Enamel hypoplasia and health condition through social status in the Roman Imperial Age

Dental enamel hypoplasia is a deficit in enamel matrix formation occurring in childhood and resulting from nutritional deficiency or diseases. Examination of hypoplastic lesions in ancient skeletal remains provides an excellent index of developmental stress levels in the past. In this research, the incidence and distribution of Linear Enamel Hypoplasia (LEH) were detected to investigate whether the social status had affected the health and nutritional conditions of the Romans during the Imperial Age. Dental enamel hypoplasia was observed in the teeth of 200 human skeletal remains found in two large necropoles from the Imperial Age in Rome (Italy). Both necropoles, dated back to (1st-2nd centuries A.D.), are located near the ancient centre of Rome and the presence of different typologies of graves, with monumental mausoleums and simple tombs, testifies that the cemeteries were used by diversified social classes. The availability of two sub-samples with different subsistence patterns in the same population permitted to evaluate the distribution of the dental stress markers evidencing the differences between the social classes. Enamel hypoplasia was collected in the whole dentition and differences were found between anterior and posterior teeth, male and female samples, upper and lower social classes. The results will be discussed taking into account other skeletal and dental indicators of health and life condition collected in the sample, and in relation to the economic and social life in Rome during the Imperial Age

Matematica, Musica e Tecnologie: un trinomio possibile

ItIn questo lavoro descriviamo come le tecnologie dell'informazione e della computazione arricchiscono il classico rapporto tra Matematica e Musica, mettendo a disposizione dell'artista nuovi metodi e strumenti per la creativita' musicale. I nuovi modelli della Scienza legati ai frattali, ai sistemi dinamici, alla complessita' e al caos forniscono una grande quantita' di strutture matematiche che attraverso opportuni codici possono essere tradotti in suoni e musica. L'artista puo' usare questo contesto per le proprie produzioni, ed il matematico puo' trovare nelle produzioni musicali una semantica delle strutture matematiche astratte che intervengono nel corso dei suoi studi. In questo lavoro vengono esplorati i rapporti tra Spazi Matematici, Spazi Sonori e Spazi Musicali e come le strutture matematiche possono essere tradotte in musica attraverso opportuni codici

A Case of Gout from Imperial Rome (1st-2nd Century AD)

The study of pathological alterations in ancient skeletal remains may contribute to the reconstruction of the history of diseases and health conditions of ancient populations. Therefore, in recent research palaeopathology provides an important point of view in bioarchaeology and medicine. This work describes the bone alterations observed in the skeleton of an adult woman found during archaeological excavations in the greatest necropolis of the Imperial Age in Rome. The skeletal remains showed some pathological anomalies and the most evident alterations consisted of multiple osteolytic lesions involving mainly the small bones of the feet, which presented round cavitations and scarce signs of bone repair. Differential diagnosis suggests that this individual was affected by gout, probably associated with hypothyroidism that determined her short stature