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

Characterization of the slowly inactivating sodium current INa2 in canine cardiac single Purkinje cells

The aim of our experiments was to investigate by means of a whole cell patch-clamp technique the characteristics of the slowly inactivating sodium current (INa2) found in the plateau range in canine cardiac Purkinje single cells. The INa2 was separated from the fast-activating and -inactivating INa (labelledhere INa1)by applying a two-step protocol.Thefirst step, froma holding potential (Vh) of −90 or −80 mV to −50 mV, led to the quick activation and inactivation of INa1. The second step consisted of depolarizations of increasing amplitude from−50 mV to less negative values, which led to the quick activation and slow inactivation of INa2. The INa2 was fittedwith a double exponential functionwith time constants of tens and hundreds milliseconds, respectively. After the activation and inactivation of INa1 at−50 mV, the slope conductance was very small and did not change with time. Instead, during INa2, the slope conductance was larger and decreased as a function of time. Progressively longer conditioning steps at−50 mVresulted in a progressive decrease in amplitude of INa2 during the subsequent test steps. Gradually longer hyperpolarizing steps (increments of 100 ms up to 600 ms) from Vh −30 mV to −100 mV were followed on return to −30 mV by a progressively larger INa2, as were gradually more negative 500 ms steps from Vh −30 mV to−90 mV. At the end of a ramp to−20 mV, a sudden repolarization to approximately−35 mV fully deactivated INa2. The INa2 was markedly reduced by lignocaine (lidocaine) and by low extracellular [Na+], but it was little affected by low and high extracellular [Ca2+]. At negative potentials, the results indicate that there was little overlap between INa2 and the transient outward current, Ito, as well as the calcium current, ICa. In the absence of Ito and ICa (blocked by means of 4-aminopyridine and nickel, respectively), INa2 reversed at 60mV. In conclusion, INa2 is a sodium current that can be initiated after the inactivation of INa1 and has characteristics that are quite distinct from those of INa1. The results have a bearing on the mechanisms underlying the long plateau of Purkinje cell action potential and its modifications in different physiological and pathological conditions

Reaching the millennium development goals : Mauritania should care

Mauritania is a resource-rich developing country. As many other African nations, it will not reach most of the Millennium Development Goals, unless the authorities commit to accelerating progress. To succeed by 2015, the government needs to: mobilize additional financial resources, introduce policy changes at the sector level, and strengthen the links between strategic objectives and the budget. Adopting the Millennium Development Goals as the overarching development framework will keep policy-makers focused on concrete results and help them avoid the so-called"natural resource curse."This paper calculates the total cost of the Millennium Development Goals and financing gap (on aggregate and for each goal); recommends changes in domestic sector policies; and proposes ways to integrate the Millennium Development Goals into the budget process. Over 2008-2015, the total cost of reaching the goals in Mauritania and the resulting financing gap stand at, respectively, around 9 and 3 percent of non-oil gross domestic product on average per year. Education is the most expensive goal in absolute terms, but the individual financing gaps are widest for poverty reduction and improving maternal health. On the policy side, sector strategies need to be aligned with the goals and resources allocated more than proportionally to the disadvantaged groups, mainly at the local level.Population Policies,Health Monitoring&Evaluation,Rural Poverty Reduction,Health Systems Development&Reform,

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

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

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

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

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

Electro-Thermal Behavior of Layer-Wound BSCCO Coils With and Without Insulation

In this work, the electro-thermal behavior of two layer-wound High Temperature Superconducting (HTS) coils, realized with and without electrical insulation, is compared. Both coils are wound from the same BSCCO tape, and have a very similar geometry, with the same number of turns and layers. A heat input is applied to both coils, by tuning the current supplied to resistive heaters realized through stainless steel tapes wound on the mandrel at the inner surface of both coils. The heaters are in contact with one full inner turn of the winding. The coils are cooled in a liquid nitrogen bath, and the heaters are supplied with a constant current. Then, the windings are charged until the tape critical current is exceeded, and the tests are repeated for different heat loads. The signals acquired through voltage taps, suitably soldered at the same locations in both windings, are compared at the same testing conditions. Finally, the electrical characteristic of the different layers of the coils is related to the temperature of the heater and of the various turns of the coil by means of a 1-D thermal model