Concentration dependent interdiffusion in InGaAs/GaAs as evidenced by high resolution x-ray diffraction and photoluminescence spectroscopy

Article copyright 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The article appeared in Journal of Applied Physics 97, 013536 (2005) and may be found at

On the Behaviour of General-Purpose Applications on Cloud Storages

Managing data over cloud infrastructures raises novel challenges with respect to existing and well studied approaches such as ACID and long running transactions. One of the main requirements is to provide availability and partition tolerance in a scenario with replicas and distributed control. This comes at the price of a weaker consistency, usually called eventual consistency. These weak memory models have proved to be suitable in a number of scenarios, such as the analysis of large data with Map-Reduce. However, due to the widespread availability of cloud infrastructures, weak storages are used not only by specialised applications but also by general purpose applications. We provide a formal approach, based on process calculi, to reason about the behaviour of programs that rely on cloud stores. For instance, one can check that the composition of a process with a cloud store ensures `strong' properties through a wise usage of asynchronous message-passing

Timed Multiparty Session Types

We propose a typing theory, based on multiparty session types, for modular verification of real-time choreographic interactions. To model real-time implementations, we introduce a simple calculus with delays and a decidable static proof system. The proof system ensures type safety and time-error freedom, namely processes respect the prescribed timing and causalities between interactions. A decidable condition on timed global types guarantees time-progress for validated processes with delays, and gives a sound and complete characterisation of a new class of CTAs with general topologies that enjoys progress and liveness

Analysis of patients' needs after liver transplantation in Tuscany: a prevalence study.

BACKGROUND: The reorganization of the healthcare system in Tuscany aims at characterizing the hospitals as a place for the treatment of acute patients. This event, together with the improvement of long-term survival after orthotopic liver transplantation (OLT), calls for a management network able to ensure effective continuity of care for patient needs in the posttransplantation period. MATERIALS AND METHODS: An observational study of prevalence has been carried out with the primary objective to evaluate patients' needs and criticalities both in routine daily life and in urgency in the posttransplantation period and the capacity of the regional health system to support them. A survey, using a semi-structured questionnaire consisting of 27 questions, was administered to all patients resident in Tuscany who underwent transplantation from 2000 to 2010. The survey tool assessed the following: socio-demographic data, personal, family and social difficulties, problems emerged in the clinical routine and urgency, resolution modality, relationships with the general practitioner and the referral specialist, and services the patients would appreciate receiving in their province of residence. RESULTS: In the study, 346 patients matched the inclusion criteria of the study, 324 gave telephone consent to participate in the survey, and 225 responded (69.4%). The most frequent difficulties were as follows: depression (39.5%), difficulty in returning to work (29.3%), low income (22.6%), lack of self-sufficiency (22.6%), addictions (19.1%) (cigarette smoking 16.4%), 12.4% eating disorders, and 18.9% other difficulties (social isolation, absence of a family network, and so on). The main reasons for dissatisfaction were as follows: difficulty to obtain the required laboratory tests and lack of a reference structure at the local health facility. Few patients have a referral specialists in their area and most of them primarily refer to the Transplant Center even late after the procedure. DISCUSSION: Early diagnosis of specific conditions (depression, addiction, and eating disorders) should be implemented in the follow-up period and services such as counselling, dietary support, rehabilitation, and social services should be provided locally. An integrated management system between the transplantation center and the local facilities (hospitals, general practitioners, primary care, and laboratories) should be implemented and referral specialized centers should be identified locally

Monitoring Networks through Multiparty Session Types

In large-scale distributed infrastructures, applications are realised through communications among distributed components. The need for methods for assuring safe interactions in such environments is recognized, however the existing frameworks, relying on centralised verification or restricted specification methods, have limited applicability. This paper proposes a new theory of monitored π-calculus with dynamic usage of multiparty session types (MPST), offering a rigorous foundation for safety assurance of distributed components which asynchronously communicate through multiparty sessions. Our theory establishes a framework for semantically precise decentralised run-time enforcement and provides reasoning principles over monitored distributed applications, which complement existing static analysis techniques. We introduce asynchrony through the means of explicit routers and global queues, and propose novel equivalences between networks, that capture the notion of interface equivalence, i.e. equating networks offering the same services to a user. We illustrate our static-dynamic analysis system with an ATM protocol as a running example and justify our theory with results: satisfaction equivalence, local/global safety and transparency, and session fidelity

Análise computacional do efeito de escala em bacias de dissipação de energia por ressalto hidráulico

O efeito de escala é um fenômeno inerente aos modelos físicos hidráulicos. Este fato ocorre, pois, se os mesmos fluidos que são utilizados nos modelos são os observados no protótipo, para o atendimento do critério de semelhança de Froude, comumente utilizado quando modelados escoamentos a superfície livre, outros critérios de semelhança entram em detrimento, como é o caso dos critérios de Reynolds e Weber, impossibilitando a garantia de uma semelhança dinâmica completa entre modelo e protótipo. A presente pesquisa tem por objetivo investigar o efeito de escala nas pressões médias no fundo uma bacia de dissipação de energia por ressalto hidráulico utilizando simulações com CFD com fluidos hipotéticos, os quais possuem viscosidade cinemática e tensão superficial fluido-ar alteradas a fim de garantir que os critérios de semelhança de Reynolds e Weber sejam respeitados, além do critério de Froude, já garantido nos modelos físicos hidráulicos que foram avaliados. Para a validação do modelo computacional, foram utilizados dados medidos em modelos físicos nas escalas 1:32, 1:50 e 1:100, além de dados medidos em escala de protótipo, representativos do sistema extravasor de cheias da UHE Porto Colômbia. Nas simulações computacionais foi utilizado o solver Ansys CFX, que resolve numericamente as equações RANS e da continuidade através do método dos volumes finitos. Para a modelagem da turbulência foi utilizado o modelo RNG − e para a modelagem do escoamento bifásico foi utilizado o método VOF. Os resultados desta dissertação são apresentados em dois artigos. No primeiro foram realizadas comparações entre os resultados obtidos nas simulações que utilizaram água como fluido principal com dados adquiridos nos modelos físicos hidráulicos. Neste artigo foram obtidos resultados satisfatórios para quatro de seis variáveis analisadas e observou-se grande influência do fenômeno de aeração nas outras duas variáveis. No segundo artigo foi realizada a análise do efeito de escala nos valores de pressão média através da utilização de fluidos hipotéticos. Verificou-se que a representação dos efeitos viscosos nos modelos, através da preservação do critério de semelhança de Reynolds, possui maior influência na prevenção do efeito de escala.The scale effect is an inherent phenomenon in hydraulic physical models. This occurs because when the same fluids used in the models are observed in the prototype to meet the Froude similarity criteria, which is commonly used when modeling freesurface flows, other similarity criteria such as Reynolds and Weber criteria are compromised, making it impossible to ensure complete dynamic similarity between the model and full-scale structure. The objective of this research is to investigate the scale effect on mean pressures at the bottom of a hydraulic jump stilling basin using CFD simulations with hypothetical fluids. These fluids have altered fluid-air kinematic viscosity and surface tension, ensuring that the Reynolds and Weber similarity criteria are respected, in addition to the Froude criterion, which is already guaranteed in the hydraulic physical models that have been evaluated. For the validation of the computational model, data obtained from physical models at scales of 1:32, 1:50, and 1:100, as well as full-scale data representing the spillway and stilling basin of the Porto Colômbia Hydroelectric Power Plant, were used. The Ansys CFX solver was employed in the computational simulations, numerically solving the RANS and continuity equations using a finite volume method. The RNG − turbulence model was used for turbulence modeling, and the VOF method was applied for two-phase flow modeling. The results of this study are presented in two papers. In the first paper, comparisons were made between the results obtained in the simulations that used water as the main fluid and data acquired from hydraulic physical models. Satisfactory results were obtained for four out of six analyzed variables, with significant influence observed from the aeration phenomenon on the other two variables. In the second paper, an analysis of the scale effect on mean pressure values was conducted using hypothetical fluids. It was found that preserving the Reynolds similarity criterion in the models, through the representation of viscous effects, has a greater influence in preventing the scale effect

Clinical determinants of the PR interval duration in Swiss middle-aged adults: The CoLaus/PsyCoLaus study.

Prolonged PR interval (PRi) is associated with adverse outcomes. However, PRi determinants are poorly known. We aimed to identify the clinical determinants of the PRi duration in the general population. Some clinical data are associated with prolonged PRi. Cross-sectional study conducted between 2014 and 2017. Electrocardiogram-derived PRi duration was categorized into normal or prolonged (>200 ms). Determinants were identified using stepwise logistic regression, and results were expressed as multivariable-adjusted odds ratio (OR) (95% confidence interval). A further analysis was performed adjusting for antiarrhythmic drugs, P-wave contribution to PRi duration, electrolytes (kalemia, calcemia, and magnesemia), and history of cardiovascular disease. Overall, 3655 participants with measurable PRi duration were included (55.6% females; mean age 62 ± 10 years), and 330 (9.0%) had prolonged PRi. Stepwise logistic regression identified male sex (OR 1.41 [1.02-1.97]); aging (65-74 years: OR 2.29 [1.61-3.24], and ≥ 75 years: OR 4.21 [2.81-6.31]); increased height (per 5 cm, OR 1.15 [1.06-1.25]); hypertension (OR 1.37 [1.06-1.77]); and hs troponin T (OR 1.67 [1.15-2.43]) as significantly and positively associated, and high resting heart rate (≥70 beats/min, OR 0.43 [0.29-0.62]) as negatively associated with prolonged PRi. After further adjustment, male sex, aging and increased height remained positively, and high resting heart rate negatively associated with prolonged PRi. Hypertension and hs troponin T were no longer associated. In a sample of the Swiss middle-aged population, male sex, aging and increased height significantly increased the likelihood of a prolonged PRi duration, whereas a high resting heart rate decreased it

The Contribution of Cognitive Factors to Compulsive Buying Behaviour: Insights from Shopping Habit Changes during the COVID-19 Pandemic

The last decade has seen an increase in compulsive behaviours among young adults worldwide, particularly in 2020, during restrictions due to the COVID-19 pandemic. Importantly, even if shopping is an ordinary activity in everyday life, it can become a compulsive behaviour for certain individuals. The aim of this study was to investigate the role of working memory and decision-making style in compulsive behaviour. A total of 105 participants (65 F, 40 M) were recruited online from May 2020 to December 2020. They completed a series of questionnaires to measure shopping compulsive behaviour, decision-making styles, deficits in working memory and online shopping habits. The results show that during the COVID-19 pandemic, people spent much more time shopping online, made more purchases and spent more money than prior to the pandemic. Moreover, both higher working memory deficits and spontaneous decision-making style predicted a greater tendency to engage in compulsive buying. These results suggest the need to develop specific training programs to improve cognitive aspects related to compulsive shopping behaviour

Numerical study of jets produced by conical wire arrays on the Magpie pulsed power generator

The aim of this work is to model the jets produced by conical wire arrays on the MAGPIE generator, and to design and test new setups to strengthen the link between laboratory and astrophysical jets. We performed the modelling with direct three-dimensional magneto-hydro-dynamic numerical simulations using the code GORGON. We applied our code to the typical MAGPIE setup and we successfully reproduced the experiments. We found that a minimum resolution of approximately 100 is required to retrieve the unstable character of the jet. We investigated the effect of changing the number of wires and found that arrays with less wires produce more unstable jets, and that this effect has magnetic origin. Finally, we studied the behaviour of the conical array together with a conical shield on top of it to reduce the presence of unwanted low density plasma flows. The resulting jet is shorter and less dense.Comment: Accepted for publication in Astrophysics & Space Science. HEDLA 2010 conference procedings. Final pubblication will be available on Springe

Real-time optical manipulation of cardiac conduction in intact hearts

Optogenetics has provided new insights in cardiovascular research, leading to new methods for cardiac pacing, resynchronization therapy and cardioversion. Although these interventions have clearly demonstrated the feasibility of cardiac manipulation, current optical stimulation strategies do not take into account cardiac wave dynamics in real time. Here, we developed an all‐optical platform complemented by integrated, newly developed software to monitor and control electrical activity in intact mouse hearts. The system combined a wide‐field mesoscope with a digital projector for optogenetic activation. Cardiac functionality could be manipulated either in free‐run mode with submillisecond temporal resolution or in a closed‐loop fashion: a tailored hardware and software platform allowed real‐time intervention capable of reacting within 2 ms. The methodology was applied to restore normal electrical activity after atrioventricular block, by triggering the ventricle in response to optically mapped atrial activity with appropriate timing. Real‐time intraventricular manipulation of the propagating electrical wavefront was also demonstrated, opening the prospect for real‐time resynchronization therapy and cardiac defibrillation. Furthermore, the closed‐loop approach was applied to simulate a re‐entrant circuit across the ventricle demonstrating the capability of our system to manipulate heart conduction with high versatility even in arrhythmogenic conditions. The development of this innovative optical methodology provides the first proof‐of‐concept that a real‐time optically based stimulation can control cardiac rhythm in normal and abnormal conditions, promising a new approach for the investigation of the (patho)physiology of the heart