4,499 research outputs found
Branching: the Essence of Constraint Solving
This paper focuses on the branching process for solving any constraint
satisfaction problem (CSP). A parametrised schema is proposed that (with
suitable instantiations of the parameters) can solve CSP's on both finite and
infinite domains. The paper presents a formal specification of the schema and a
statement of a number of interesting properties that, subject to certain
conditions, are satisfied by any instances of the schema.
It is also shown that the operational procedures of many constraint systems
including cooperative systems) satisfy these conditions.
Moreover, the schema is also used to solve the same CSP in different ways by
means of different instantiations of its parameters.Comment: 18 pages, 2 figures, Proceedings ERCIM Workshop on Constraints
(Prague, June 2001
New Silver Nanosensor for Nickel Traces. Part II: Urinary Nickel Determination Associated to Smoking Addiction
A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactorily applied to nickel determination in urine without previous treatment, coming from subjects with different smoking addiction levels and second hand smokers. Within-day precision was better than 0.011 CV. The reproducibility (between-days precision) was also evaluated over 3 days by performing six determinations each day with a CV of 0.025. The proposed methodology represents a promising approach in the area of biological monitoring due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents. Obtained results of urinary nickel concentration were successfully correlated with the tobacco addiction.Fil: Talio, MarĂa Carolina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Luis. Instituto de QuĂmica de San Luis. Universidad Nacional de San Luis. Facultad de QuĂmica, BioquĂmica y Farmacia. Instituto de QuĂmica de San Luis; ArgentinaFil: Luconi, M. O.. Universidad Nacional de San Luis; ArgentinaFil: Fernandez, Liliana Patricia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Luis. Instituto de QuĂmica de San Luis. Universidad Nacional de San Luis. Facultad de QuĂmica, BioquĂmica y Farmacia. Instituto de QuĂmica de San Luis; Argentin
Mechanism of action studies on new ligands for soluble guanylate cyclase.
This thesis will comprise two topics. The first part relates to the application of photoaffinity labelling to soluble guanylate cyclase (sGC), which belongs to a family of enzymes that catalyse the conversion of guanosine-5'-triphosphate (GTP) to cyclic guanosine-3', 5'- monophosphate (cGMP). By formation of the intracellular signalling molecule cGMP, sGC plays a key role in smooth muscle relaxation and inhibition of platelet aggregation and in many signal transduction pathways. Although there are two types of activators of sGC, NO-dependent (nitrovasodilators such as sodium nitroprusside, DEANO, etc.) and NO-independent (YC-1, l-benzyl-3- 5'-hydroxymethyl-2'-furyl indazole), the mechanism of action of only the former is understood. This thesis describes an attempt to locate residues that make up the binding sites for these activators. This comprises the design, synthesis and biological evaluation of small molecule activators, and their photolabeled analogues, followed by photoafiinity labelling experiments using tryptic digestion and mass spectroscopy (MALDI) for the identification of peptide fragments covalently bonded to activator analogue. The second part involves the investigation of a traceless linker designed for use in the solid phase synthesis of sGC modulators. The resulting method could also be applied in the synthesis of a variety of biologically active molecules. We wanted to design a linker which would combine the advantages of a traceless and a "safety-catch" linker. Therefore we investigated the application of a benzoisothiazol-based linker as this heterocycle is stable until activated by oxidation of the sulphur atom, allowing facile cleavage in the last step of the synthesis
Teaching Pride and Prejudice by Jane Austen through a Series of Lesson Plans in the 21st Century
This project encompasses a series of seventeen lesson plans covering a 3-week period of classroom teaching on Pride and Prejudice by Jane Austen. These lesson plans are designed to be taught in a span of fifty minutes. They were also created for an 11th grade College Preparatory(CP) class in which both native English speakers and multilingual students, who have a high World-Class Instructional Design and Assessment (WIDA) level can be found. These students are at a WIDA Level 5, which means they have advanced listening, writing, speaking, and reading skills. Although these multilingual students find themselves at the highest WIDA Level, they recently got out of the ESL program and might still need support navigating the challenges of a mainstream English classroom. The student population is as follows: 25 students in totalâ10 Hispanic students from Ecuador, El Salvador, and Puerto Rico, 3 Vietnamese students, and the rest are native English speakers
The Influence of Green Strategies Design onto Quality Requirements Prioritization
[Context and Motivation] Modern society is facing important challenges that are critical to improve its environmental performance. The literature reports on many green strategies aimed at reducing energy consumption. However, little research has been carried out so far on including green strategies in software design. [Question/problem] In this paper, we investigate how green software strategies can contribute to, and influence, quality requirements prioritization performed iteratively throughout a service-oriented software design process. [Methodology] In collaboration with a Dutch industry partner, an empirical study was carried out with 19 student teams playing the role of software designers, who completed the design of a real-life project through 7 weekly deliverables. [Principle ideas/results] We identified a list of quality requirements (QRs) that were considered by the teams as part of their architectural decisions when green strategies were introduced. By analyzing relations between QRs and green strategies, our study confirms usability as the most used QR for addressing green strategies that allow to create people awareness. Qualities like reliability, performance, interoperability, scalability and availability emerged as the most relevant for addressing service-awareness green strategies. [Contribution] If used at the beginning of a green software project, our results help including the most relevant QRs for addressing those green software strategies that are e.g. the most domain-generic (like increase carbon footprint awareness, paperless service provisioning, virtualization)
Characterizing the contribution of quality requirements to software sustainability
Most respondents considered modifiability as relevant for addressing both technical and environmental sustainability. Functional correctness, availability, modifiability, interoperability and recoverability favor positively the endurability of software systems. This study has also identified security, satisfaction, and freedom from risk as very good contributors to social sustainability. Satisfaction was also considered by the respondents as a good contributor to economic sustainability. Background Since sustainability became a challenge in software engineering, researchers mainly from requirements engineering and software architecture communities have contributed to defining the basis of the notion of sustainability-aware software. Problem Despite these valuable efforts, the assessment and design based on the notion of sustainability as a software quality is still poorly understood. There is no consensus on which sustainability requirements should be considered. Aim and Method To fill this gap, a survey was designed with a double objective: i) determine to which extent quality requirements contribute to the sustainability of software-intensive systems; and ii) identify direct dependencies among the sustainability dimensions. The survey involved different target audiences (e.g. software architects, ICT practitioners with expertise in Sustainability). We evaluated the perceived importance/relevance of each sustainability dimension, and the perceived usefulness of exploiting a sustainability model in different software engineering activities. Result
Spectrofluorimetric determination of sildenafil: a new analytical alternative for its analysis
In aqueous solutions, sildenafil presents a very low fluorescence emission and a limited linear range. In presence of a cationic surfactant hexadecyltrim ethylammonium bromide (HTAB, method A) and anionic surfactant sodium dodecyl sulfate (SDS, method B) a great fluorescence enhancement was observed and the linearity range was enlarged. These surfactants-drug interactions lead to the development of two sensitive methods for sildenafil spectrofluorimetric determination. Nature of interactions between sildenafil and surfactants were studied and different parameters which influence these associations were discussed. Sildenafil was quantitatively determined at an emission wavelength of 435 nm and 415 nm by method A and B respectively with detection limit of 0.0012 ”g mL-1 and 0.0016 ”g mL-1. The methods have been successfully applied to the analysis of bulk drug, tablets and herbal medicines.Fil: Wang, Chien Chun. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico San Luis. Instituto de QuĂmica de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de QuĂmica, BioquĂmica y Farmacia; ArgentinaFil: Fernandez, Liliana Patricia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico San Luis. Instituto de QuĂmica de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de QuĂmica, BioquĂmica y Farmacia; Argentin
Analysis of Electrical Phenomena Occurring in Thermally Assisted Mechanical Dewatering Processes (TAMD)-a Preliminary Study
International audienc
Development of a highly sensitive noncompetitive electrochemical immunosensor for the detection of atrazine by phage anti-immunocomplex assay
The development of immunosensors for the detection of small molecules is of great interest because of their simplicity, high sensitivity and extended analytical range. Due to their size, small compounds cannot be simultaneously recognized by two antibodies impeding their detection by noncompetitive two-site immunoassays, which are superior to competitive ones in terms of sensitivity, kinetics, and working range. In this work, we combine the advantages of magneto-electrochemical immunosensors with the improved sensitivity and direct proportional signal of noncompetitive immunoassays to develop a new Phage Anti-Immunocomplex Electrochemical Immunosensor (PhAIEI) for the detection of the herbicide atrazine. The noncompetitive assay is based on the use of recombinant M13 phage particles bearing a peptide that specifically recognizes the immunocomplex of atrazine with an anti-atrazine monoclonal antibody. The PhAIEI performed with a limit of detection (LOD) of 0.2 pg mLâ1, which is 200-fold better than the LOD obtained using the same antibody in an optimized conventional competitive ELISA, with a large increase in working range. The developed PhAIEI was successfully used to assay undiluted river water samples with no pretreatment and excellent recoveries. Apart from the first demonstration of the benefits of integrating phage anti-immunocomplex particles into electrochemical immunosensors, the extremely low and environmentally relevant detection limits of atrazine attained with the PhAIEIS may have direct applicability to fast and sensitive detection of this herbicide in the environment.Fil: GonzĂĄlez Techera, AndrĂ©s. Universidad de la RepĂșblica; UruguayFil: Zon, MarĂa Alicia. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas FisicoquĂmicas y Naturales. Departamento de QuĂmica. Area ElectroquĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Molina, Patricia Gabriela. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas FisicoquĂmicas y Naturales. Departamento de QuĂmica. Area ElectroquĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Fernandez, Hector. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas FisicoquĂmicas y Naturales. Departamento de QuĂmica. Area ElectroquĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: GonzĂĄlez Sapienza, Gualberto. Universidad de la RepĂșblica; UruguayFil: Arevalo, Fernando Javier. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas FisicoquĂmicas y Naturales. Departamento de QuĂmica. Area ElectroquĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
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