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Tampa, FL, United States

Jayashree H.V.,PESIT | Thapliyal H.,USF | Agrawal V.K.,PESIT
Proceedings of the IEEE International Conference on VLSI Design | Year: 2014

Quantum computation is modeled by quantum circuits. All the quantum operations are reversible so the quantum circuits can be built using reversible logic gates. Reversible computing is the emerging technology, its major role is in the field of quantum computing, optical computing, and design of low power nanocircuits. The most frequently used computational unit for digital signal processing and multimedia applications is multiplier. To compute square of an operand, regular multipliers are used in general. This paper proposes a dedicated quantum circuit for computing square of an operand efficiently compared to the existing multipliers in the literature. The squaring unit is mathematically modeled and its metrics quantum cost, garbage outputs and ancilla input, gate count are calculated. We compared the proposed design with the existing multipliers to compute square and found that proposed square unit is efficient in terms of quantum cost, garbage outputs, ancilla inputs and gate count. The proposed reversible square circuit has 63% to 85% improvement of quantum cost, garbage outputs, ancilla inputs and gate count over existing reversible multiplier circuits. © 2014 IEEE. Source


Martinez C.A.R.,Post Graduate Program in Health science | Ribeiro M.L.,Post Graduate Program in Health science | Gambero A.,Post Graduate Program in Health science | Miranda D.D.D.C.,Scientific Initiation Program PIBIC | And 2 more authors.
Acta Cirurgica Brasileira | Year: 2010

Purpose: Quantify the levels of oxidative DNA damage of epithelial colon cells comparing segments with and without fecal stream. Methods: Sixty Wistar rats were subjected to deviation of fecal stream by proximal colostomy and a distal mucosal fistula. Animals were divided into three experimental groups that were sacrificed 6, 12 and 24 weeks after surgery. In each experimental group, five animals underwent laparotomy without intestinal deviation (sham subgroup). The diagnosis of colitis was made by histopathological analysis and the inflammatory activity index by graduated scale. The neutrophil infiltration was determined by myeloperoxidase tissue levels and the intensity of oxidative DNA damage by comet assay. The Mann-Withney and Student t test were used to compare the results among experimental subgroups and the Kruskal-Wallis test for variance analysis, adopting a significance level of 5% (p≤0.05). Results: Colon segments without fecal stream was shown higher histological inflammatory score of the colon wall after 12 and 24 weeks (p=0.001) that increased with the time of diversion (p=0.01). The activity of myeloperoxidase in segments without fecal stream decreased with the time (p=0.001). Oxidative DNA damage levels were significantly higher in the segments without fecal stream, (p=0.0001), independent of time of colon diversion, and increase with the time (p=0.0007). Conclusions: Colon segments without fecal stream showed high levels of oxidative DNA damage related to histological alterations observed in diversion colitis. The levels of oxidative DNA damage in segments devoid of the fecal stream increase with the time of intestinal exclusion. Source


Turkmen F.,University of Trento | Jung E.,USF | Crispo B.,University of Trento
Proceedings - 2011 IEEE International Symposium on Policies for Distributed Systems and Networks, POLICY 2011 | Year: 2011

The notion of "session" created a considerable debate in access control. Recent research demonstrated that many access control constraints can not be verified statically at design time. The user behavior during an active session is uncertain, sessions are concurrent and some authorization decision parameters (i.e. conditions) are only available at runtime. However, similarly to what is done in software verification, it is possible to give static indications about the run-tim behavior of the access control system, by analyzing a finite number of approximations that model both the user behavior and the decision parameters. Moreover, constraints (e.g. history-based ones) can be analyzed in combination rather than individually. In this paper, we present a framework tailored to the verification of run-time constraints and security properties (e.g. mutually exclusive roles) for role based access control systems. Our framework employs actors to mimic active entities at runtime and creates stochastic activity entropies from a set of permission and role activations. A security administrator can obtain a set of run-time trajectories with a finite number of simulations that can be used to verify the desired properties. © 2011 IEEE. Source


Cazal M.,USF
IET Conference Publications | Year: 2011

The paper discuss various environmental measures for the low-carbon city in France, such as Eco-districts and Eco-cities, High Environmental Quality "HQE", Low-Energy Consumption Building (BBC), The Climate Energy Plan etc. Source


News Article
Site: http://phys.org/chemistry-news/

A fragment of the Seymchan meteorite from Russia. The majority of this 6 inch meteorite consists of iron-nickel metal, and the darker-colored structure in the center is schreibersite. Credit: University of South Florida On the early Earth, light came not only from the sun but also from the incessant bombardment of fireball meteorites continually striking the planet. Now, the recent work of University of South Florida (USF) associate professor of geology Matthew Pasek, USF researcher Maheen Gull, and colleagues at Georgia Institute of Technology, has demonstrated that these meteorites may have carried within them an extraterrestrial mineral that, as it corroded in water on Earth, could have provided the essential chemical spark leading to the birth of biological life on the planet. In previous work, Pasek and colleagues suggested that the ancient meteorites contained the iron-nickel phosphide mineral "schreibersite," and that when schreibersite came into contact with Earth's watery environment a phosphate, a salt, was released that scientists believe could have played a role in the development of "prebiotic" molecules. In a recent study appearing in Nature Publishing Group's Scientific Reports, the researchers focused on the properties of schreibersite and conducted experiments with the mineral to better understand how - in a chemical reaction with the corrosive effects of water called "phosphorylation" - schreibersite could have provided the phosphate important to the emergence of early biological life. "Up to ten percent of the Earth's crustal phosphate may have originated from schreibersite, so the mineral was abundant and readily available to engage in early chemical reactions," said Pasek. "This ready and abundant source of reactive phosphorous may have been an important part of the prebiotic Earth and possibly the planet Mars," said Pasek. What needed to be determined, however, was just how schreibersite reacted chemically with the early Earth's watery environment and what resulted from the chemical reaction. To test their hypothesis, they built an early Earth model environment, an organic-rich aqueous solution in which schreibersite might react and corrode in a way similar to how events may have unfolded in prebiotic chemistry. The model they constructed provided an opportunity to observe the thermodynamics of phosphorylation reactions of a phosphorus-containing synthetic schreibersite, which they created to be structurally identical to its meteorite counterpart. "A thorough exploration of the extent of phosphorylation of nucleosides (made of a base and a five carbon sugar) by schreibersite was necessary to evaluate its potential prebiotic importance," explained Gull, a post-doctoral fellow and visiting researcher at USF. "All of our experiments indicated that a basic pH, rather than acidic pH, was required for the production of phosphorylated products. Although phosphorylation can take place using a variety of phosphate minerals in non-aqueous solution, prebiotic oxidation in water is more likely given the dominance of water across the solar system." The prebiotic reaction they duplicated in the laboratory may have been similar to the reactions that ultimately led to the emergence of metabolic molecules, such as adenosine triphosphate (ATP), which is called the 'molecule of life' because it is central to energy metabolism in all life. Pasek and Gull also explained that even life today builds from activated nucleotides and that phosphates are still an important part of metabolic processes in biological life, so it is likely that a phosphorylated biomolecule played an important part in creating the prebiotic chemical context from which biological life emerged. Prior work on nucleoside phosphorylation has shown that inorganic phosphate can serve as both a catalyst and a reactant in nucleoside synthesis, they said. "The reactions we observed in our experiments have shown that the necessary prebiotic molecules were likely present on the early Earth and that the Earth was predisposed to phosphorylated biomolecules," the researchers concluded. "Our results suggest a potential role for meteoritic phosphorus in the development and origin of early life." The researchers also concluded that the mechanism of phosphorylation was still unknown and actively being investigated. "It is possible that the process occurs in solution or on the surface of the schreibersite," they explained. Explore further: Life's first taste of phosphorus

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