314 research outputs found
MultiVeStA: Statistical Model Checking for Discrete Event Simulators
No full textThe modeling, analysis and performance evaluation of large-scale systems are difficult tasks. Due to the size and complexity of the considered systems, an approach typically followed by engineers consists in performing simulations of systems models to obtain statistical estimations of quantitative properties. Similarly, a technique used by computer scientists working on quantitative analysis is Statistical Model Checking (SMC), where rigorous mathematical languages (typically logics) are used to express systems properties of interest. Such properties can then be automatically estimated by tools performing simulations of the model at hand. These property specifications languages, often not popular among engineers, provide a formal, compact and elegant way to express systems properties without needing to hard-code them in the model definition. This paper presents MultiVeStA, a statistical analysis tool which can be easily integrated with existing discrete event simulators, enriching them with efficient distributed statistical analysis and SMC capabilities
A Computational Field Framework for Collaborative Task Execution in Volunteer Clouds
Get PDFThe increasing diffusion of cloud technologies is opening new opportunities for distributed and collaborative computing. Volunteer clouds are a prominent example, where participants join and leave the platform and collaborate by sharing their computational resources. The high dynamism and unpredictability of such scenarios call for decentralized self-* approaches to guarantee QoS. We present a simulation framework for collaborative task execution in volunteer clouds and propose one concrete instance based on Ant Colony Optimization, which is validated through a set of simulation experiments based on Google workload data
Genetic testing of metabolic disorders
No full textSome hundreds of human hereditary biochemical disorders have been discovered. When the term metabolic disease is used as a query for the OMIM search program 429 entries are obtained, about half of which are due to a defective protein. The resulting phenotypes commonly appear in the early years of life. Most inborn errors of metabolism are individually rare but altogether they represent a considerable burden for the health system. Children with inborn errors of metabolism may present with one or more of a large variety of signs and symptoms. Once clinical suspicion of an inborn metabolic error is raised, a basic evaluation protocol should be followed, including: blood gas analysis, glucose, electrolytes, ammonia, lactic acid, uric acid, transaminases, calcium, lactate/pyruvate and 3-hydroxybutyrate/acetoacetate ratios; search for ketone bodies, alpha-keto acids and reducing substances in urine. Further information may derive from analysis of amino acids, organic acids, mucopolysaccharides, oligosaccharides in biological fluids. A third step is represented by the identification of a specific enzyme deficiency. DNA analysis represents a useful complement to conventional biochemical investigation, providing final confirmation of the diagnosis. For an increasing number of conditions, genotyping appears largely preferable, as compared to the traditional biochemical approach, in terms of cost, time and safety for the patient. Here we discuss some examples on inherited metabolic disorders including: X-linked ichthyosis, glycogenosis type 1, hereditary fructose intolerance, lysinuric protein intolerance, cystinuria, Gaucher disease, Smith-Lemli-Opitz syndrome, X-linked recessive chondrodysplasia punctata. Prenatal diagnosis and carrier identification of several metabolic disorders are available using conventional biochemical approaches. However, for other metabolic disorders this goal can be obtained by DNA analysis only. A new aspect of inherited metabolic traits is that they can be risk factors for multifactorial genetic disease. Moderate hyperhomocysteinemia clue to genetic variants of cystathionine-synthase and 5,10-methylenetetrahydrofolate reductase has been thoroughly investigated in early vascular disease and neural tube defects. Planning of the molecular diagnosis of a specific metabolic disorder needs a careful survey of mutations due to a high allelic heterogeneity frequently observed in Italian patients such as those affected by phenylketonuria, homocystinuria, lysinuric protein intolerance. The allelic heterogeneity raises the question about the cost of each mutational testing. Future development of new technologies, such as the in silico analysis, will make the molecular diagnosis more rapid and cheaper
Lysinuric protein intolerance characterized by bone marrow abnormalities and severe clinical course
No full textSTUDY OBJECTIVE:
To evaluate phenotypic variability of lysinuric protein intolerance in a cohort of nine Italian patients.
DESIGN:
Retrospective analysis of patient records.
SUBJECTS:
Nine Italian patients (seven independent families), all originating from southern Italy, observed during the last 14 years.
RESULTS:
Some of the patients had unique clinical features, including bone marrow abnormalities featuring erythroblastophagocytosis (five patients) and clinical course and the outcome of the disease, have also been observed: respiratory involvement was present in five cases, with a lethal picture of "alveolar proteinosis" in one. Severe kidney involvement, with both glomerular and tubular damage and rapidly progressing to chronic renal failure, has been observed in one case.
CONCLUSION:
Lysinuric protein intolerance may cause severe multisystem involvement, which requires early and careful monitoring. Some peculiar clinical findings observed in Italian patients point to a genetic heterogeneity of lysinuric protein intolerance
Severe Encephalomyopathy, external ophthalmoplegia and failure to thrive: report of a case.
No full textSLC7A8, a gene mapping within the lysinuric protein intolerance critical region, encodes a new member of the glycoprotein-associated amino acid transporter family.
No full text- …
