Read Operators and their Expressiveness in Process Algebras

We study two different ways to enhance PAFAS, a process algebra for modelling asynchronous timed concurrent systems, with non-blocking reading actions. We first add reading in the form of a read-action prefix operator. This operator is very flexible, but its somewhat complex semantics requires two types of transition relations. We also present a read-set prefix operator with a simpler semantics, but with syntactic restrictions. We discuss the expressiveness of read prefixes; in particular, we compare them to read-arcs in Petri nets and justify the simple semantics of the second variant by showing that its processes can be translated into processes of the first with timed-bisimilar behaviour. It is still an open problem whether the first algebra is more expressive than the second; we give a number of laws that are interesting in their own right, and can help to find a backward translation.Comment: In Proceedings EXPRESS 2011, arXiv:1108.407

Automated Analysis of MUTEX Algorithms with FASE

In this paper we study the liveness of several MUTEX solutions by representing them as processes in PAFAS s, a CCS-like process algebra with a specific operator for modelling non-blocking reading behaviours. Verification is carried out using the tool FASE, exploiting a correspondence between violations of the liveness property and a special kind of cycles (called catastrophic cycles) in some transition system. We also compare our approach with others in the literature. The aim of this paper is twofold: on the one hand, we want to demonstrate the applicability of FASE to some concrete, meaningful examples; on the other hand, we want to study the impact of introducing non-blocking behaviours in modelling concurrent systems.Comment: In Proceedings GandALF 2011, arXiv:1106.081

Lower Lochkovian (Lower Devonian) conodonts from Cellon section (Carnic Alps, Austria)

The conodont stratigraphy of the lower Lochkovian part of the famous Cellon section is presented. The association includes twenty-two taxa belonging to nine genera, and allows discriminating the two biozones of the lower Lochkovian (Icr. hesperius and Icr. postwoschmidti zones). Three taxa (Zieglerodina formosa, Z. mashkovae and Z. prosoplatys) are reported for the first time from the Carnic Alps, and other two species of Zieglerodina, probably new, are described in open nomenclature

Virtualization of foods: applications and perspectives toward optimizing food systems

Food production cannot be decoupled from human and planetary wellbeing. Meeting safety, nutritional, sensorial, and even price requirements entails applying an integral view of food products and their manufacturing and distribution processes. Virtualization of food commodities and products, i.e., their digital representation, offers opportunities to study, simulate, and predict the contributions of internal (e.g., composition and structure) and external factors (e.g., processing conditions) to food quality, safety, stability, and sustainability. Building virtual versions of foods requires a holistic supporting framework composed of instrumental and computational techniques. The development of virtual foods has been bolstered by advanced tools for collecting data, informing and validating modelling, e.g., micro-computed tomography, to accurately assess native food structures, multi-omics approaches, to acquire vast information on composition and biochemical processes, and nondestructive and real-time sensing, to facilitate mapping and tracking changes in food quality and safety in real-world situations. Comprehensive modeling techniques (including heat and mass transfer, thermodynamics, kinetics) built upon physic laws provide the base for realistic simulations and predictions of food processes that a virtual food might undergo. Despite the potential gaps in knowledge, increasing the adoption of food virtualization (data-based, physics-based or hybrid) in manufacturing and food systems evaluation can facilitate the optimal use of resources, the rational design of functional characteristics, and even inform the customization of composition and structural components for better product development. This mini-review focuses on critical steps for developing and applying virtual foods, their future trends, and needs

Fairness of components in system computations

In this paper we provide a simple characterization of (weak) fairness of components as defined by Costa and Stirling. The study is carried out at system specification level by resorting to a common process description language. This paper follows and exploits similar techniques as those developed in an earlier paper -- where fairness of actions was taken into account and was contrasted to the PAFAS timed operational semantics -- but the characterization of fair executions is based on a new semantics for PAFAS; it makes use of only two copies of each basic action instead of infinitely many and allows for a simple and finite representation of fair executions by using regular expressions. The new semantics can also be understood as describing timed behaviour of systems with upper time bounds. The paper discusses in detail how this new semantics differs from the old one, and why theses changes are necessary to properly capture fairness of components

LIFE-THREATENING HYPOCALCEMIA IN A PATIENT WITH HIGHLY SUSPECTED OSTEOMALACIA: A CASE REPORT

ABSTRACT: Objective: Osteomalacia is a metabolic bone disease characterized by impaired mineralization with increased non-mineralized osteoid tissue, increased frailty, and reduced bone mineral density. A common cause of osteomalacia in adults and the elderly is severe deficiency of vitamin D, which leads to chronic hypocalcemia, hypophosphatemia, and secondary hyperparathyroidism. The objective of this case report is to describe an unusual clinical presentation of osteomalacia, consisting of life-threatening acute hypocalcemia.Methods: Clinical, laboratory, and imaging data are presented.Results: We report the case of a 65-year-old man that showed symptoms and signs of severe and prolonged hypocalcemia due to unrecognized vitamin D deficiency. He presented at the emergency room reporting abdominal pain and vomiting since the evening before. Blood tests showed increased levels of rhabdomyolysis markers, severe hypocalcemia, hypophosphatemia, hypomagnesemia, normal renal function, elevated levels of alkaline phosphatase, extremely high levels of parathyroid hormone, and hypovitaminosis D. Radiological skeletal features of bone demineralization and bone abnormalities suggestive of osteomalacia were additionally detected. Other secondary causes of hypocalcemia were excluded. Clinical and biochemical resolution were progressively obtained only after an intramuscular loading dose of cholecalciferol was added to the standard calcium intravenous replacement therapy.Conclusion: This case report shows that osteomalacia consequent to a severe vitamin D deficiency can present with acute symptoms and signs of severe hypocalcemia requiring hospital admission. In such cases, vitamin D administration, and not intensive calcium supplementation alone, is essential to achieve clinical resolution of symptoms and normalization of mineral metabolism parameters.Abbreviations: 25-OH-D 25-hydroxyvitamin D CT computed tomography IV intravenous PTH parathyroid hormon