Search results for "COMPUTATION"
showing 10 items of 7362 documents
Robustness of asymmetry and coherence of quantum states
2016
Quantum states may exhibit asymmetry with respect to the action of a given group. Such an asymmetry of states can be considered as a resource in applications such as quantum metrology, and it is a concept that encompasses quantum coherence as a special case. We introduce explicitly and study the robustness of asymmetry, a quantifier of asymmetry of states that we prove to have many attractive properties, including efficient numerical computability via semidefinite programming, and an operational interpretation in a channel discrimination context. We also introduce the notion of asymmetry witnesses, whose measurement in a laboratory detects the presence of asymmetry. We prove that properly c…
Factors Influencing Lower Secondary School Pupils’ Success in Programming Projects in Scratch
2020
In the Czech Republic, a radical change in the school curriculum is planned. Through a new, compulsory subject of “Informatics and ICT”, the aim is to develop digital literacy across all school subjects, and computational thinking. Computational thinking will be implemented in the curriculum of pre-primary, primary, lower and upper secondary schools, and in teacher education at all faculties of education in the Czech Republic. To ensure readiness for the implementation of the new subject, it has been necessary to prepare and develop a set of learning materials for pupils and teaching guidelines for teachers. These textbooks focus on robotics, programming (Scratch, Python), and theoretical c…
Quantum memories with zero-energy Majorana modes and experimental constraints
2016
In this work we address the problem of realizing a reliable quantum memory based on zero-energy Majorana modes in the presence of experimental constraints on the operations aimed at recovering the information. In particular, we characterize the best recovery operation acting only on the zero-energy Majorana modes and the memory fidelity that can be therewith achieved. In order to understand the effect of such restriction, we discuss two examples of noise models acting on the topological system and compare the amount of information that can be recovered by accessing either the whole system, or the zero-modes only, with particular attention to the scaling with the size of the system and the e…
Expectation Damages and Bilateral Cooperative Investments
2012
We examine the efficiency of the standard breach remedy expectation damages in a setting where the buyer invests cooperatively and the seller invests both cooperatively and selfishly. Contracts may specify a required quality level and an upper bound to the seller's coordination costs. We find that it is optimal to write an augmented Cadillac contract in which quality is stipulated such that it cannot be met with positive probability together with a very low price. Thus, the seller becomes a residual claimant and the coordination-cost threshold can be used to balance the incentives of the buyer.
Drifting through Basic Subprocesses of Reading: A Hierarchical Diffusion Model Analysis of Age Effects on Visual Word Recognition
2016
International audience; Reading is one of the most popular leisure activities and it is routinely performed by most individuals even in old age. Successful reading enables older people to master and actively participate in everyday life and maintain functional independence. Yet, reading comprises a multitude of subprocesses and it is undoubtedly one of the most complex accomplishments of the human brain. Not surprisingly, findings of age-related effects on word recognition and reading have been partly contradictory and are often confined to only one of four central reading subprocesses, i.e., sublexical, orthographic, phonological and lexico-semantic processing. The aim of the present study…
Data from: Extinction and recolonization of maritime Antarctica in the limpet Nacella concinna (Strebel, 1908) during the last glacial cycle: toward …
2013
Quaternary glaciations in Antarctica drastically modified geographical ranges and population sizes of marine benthic invertebrates and thus affected the amount and distribution of intraspecific genetic variation. Here, we present new genetic information in the Antarctic limpet Nacella concinna, a dominant Antarctic benthic species along shallow ice-free rocky ecosystems. We examined the patterns of genetic diversity and structure in this broadcast spawner along maritime Antarctica and from the peri-Antarctic island of South Georgia. Genetic analyses showed that N. concinna represents a single panmictic unit in maritime Antarctic. Low levels of genetic diversity characterized this population…
Synthesis, computational evaluation and pharmacological assessment of acetylsalicylic esters as anti-inflammatory agents
2019
A convenient approach to the synthesis of alkyl esters of aspirin (ASA-OR) has been developed. The synthesis of ASA-OR has been realized in two steps: (1) direct esterification of salicylic acid with alcohols in the presence of dicyclohexylcarbodiimide to give alkyl salicylates (SAL-OR); (2) acetylation of SAL-OR with acetyl chloride to yield ASA-OR. Molecular mechanics simulations, performed to calculate the kinetic radii of several ASA-OR, indicated that the pentyl and hexyl acetylsalicylates possess the best properties to cross cell membranes. The in vitro biological tests demonstrate their anti-inflammatory activity, superimposable to that of aspirin. The results of our study suggest th…
Drugs Repurposing for Coronavirus Treatment: Computational Study Based On Molecular Topology
2020
The present communication illustrates the results of a computational study based on molecular topology, focused on the repositioning of drugs to treat the SARS-CoV-2 virus, better known as coronavirus, responsible for the COVID-19 disease. Using lopinavir, a well-known viral protease inhibitor as the reference drug, a mathematical pattern is found allowing the screening of the market drugs, searching for potential candidates to inhibit the said enzyme. This way new possible therapeutic alternatives to fight the coronavirus are found. Results indicate that antivirals such as brecanavir, as well as various groups of drugs, among which are antibiotics of the macrolide family (azithromycin, cla…
Theoretical prediction of the photoinduced chemiluminescence of pesticides
2007
Although it is relatively easy to find chemiluminescent (CL) molecules working on the field of direct liquid phase (especially employing strong oxidants), the molecules found as chemiluminescent are normally very weak CL compounds for developing suitable analytical CL-procedures. Therefore, it is mandatory to develop new strategies to enhance in a simple way the native chemiluminescence of such a compounds, and even to increase the number of compounds to be determined by direct chemiluminescence. Photoinduced chemiluminescence (Ph-CL) results in a simple and easily on-line accessible strategy to solve these disadvantages. In the present paper, molecular connectivity, a topological method wh…
Non-covalent interactions of N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives—a case of intramolecular N-oxide hydrogen bonds
2017
The crystal structures of new N-phenyl-1,5-dimethyl-1H-imidazole-4-carboxamide 3-oxide derivatives are reported. The results of X-ray diffraction showed the existence of intramolecular hydrogen bonding between carboxamide nitrogen donors and N-oxide oxygen acceptors. The use of Quantum Theory of Atoms in Molecules allowed its classification as a strong interaction, with energy about 10 kcal/mol, and of intermediate character between closed shell and shared bonds. Comparison of experimental data and quantum theoretical calculations indicated that a substituent attached to the phenyl ring in the para position influences the strength and geometry of the title hydrogen bonding. Stronger π-elect…