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Search Results: 1 - 10 of 9756 matches for " Pablo; Chalfoun "
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Subliminal Cues While Teaching: HCI Technique for Enhanced Learning
Pierre Chalfoun,Claude Frasson
Advances in Human-Computer Interaction , 2011, DOI: 10.1155/2011/968753
Abstract: This paper presents results from an empirical study conducted with a subliminal teaching technique aimed at enhancing learner's performance in Intelligent Systems through the use of physiological sensors. This technique uses carefully designed subliminal cues (positive) and miscues (negative) and projects them under the learner's perceptual visual threshold. A positive cue, called answer cue, is a hint aiming to enhance the learner's inductive reasoning abilities and projected in a way to help them figure out the solution faster but more importantly better. A negative cue, called miscue, is also used and aims at obviously at the opposite (distract the learner or lead them to the wrong conclusion). The latest obtained results showed that only subliminal cues, not miscues, could significantly increase learner performance and intuition in a logic-based problem-solving task. Nonintrusive physiological sensors (EEG for recording brainwaves, blood volume pressure to compute heart rate and skin response to record skin conductivity) were used to record affective and cerebral responses throughout the experiment. The descriptive analysis, combined with the physiological data, provides compelling evidence for the positive impact of answer cues on reasoning and intuitive decision making in a logic-based problem-solving paradigm. 1. Introduction The use of technology to build Intelligent User Interfaces (IUI) has revolutionized the way computers interact with human beings. Examples of these IUIs can be found in virtually every aspect of our lives, such as mobile media sharing [1, 2], intelligent vehicular assistance [3], and mental spelling machines [4]. One growing area of research within the HCI community recently has been focusing towards the design of smart interfaces for learning. Indeed, a smart interface should be able, in a learning context, to detect the user’s emotional and cognitive states in order to adjust and adapt the teaching material accordingly. Such adaptive systems relying on efficient IUIs are known as intelligent tutoring systems and are comprised of multiple goal-specific modules to aid the learner. One of these modules, called the tutor, makes use of cognitive pedagogical strategies and affective states to properly model human cognition according to the learner’s constant needs and evolution. The tutor takes advantage of recent development in IUI to efficiently communicate with the learner. This multidisciplinary field of research tries to accomplish this daunting goal of user-modeling and adaptation by implementing the most recent evolutions
Biological control and bioactive microbial metabolites: a coffee quality perspective
Chalfoun, Sara Maria;
Ciência e Agrotecnologia , 2010, DOI: 10.1590/S1413-70542010000500001
Abstract: the improvement of techniques of biological control and the use of metabolites produced by microorganisms to obtain products that can be applied in various fields, is getting stronger in face of the undeniable advantages in relation to the models currently in adopted. this review, besides general considerations about the principles and the application of measures of biological control and usage of metabolites produced by microorganisms as sustainable alternatives for the agrochemical segment, among others, reports theexperience lived by the author and the institutions to which she is associated, concerning identification, characterization and development of a biological fungicide resulting from the encapsulation of the fungus cladosporium cladosporioides (fres.) de vries, after proving its bioprotecting action on the quality of the coffee. the possibility of using microorganisms as a source of metabolites obtained from biological extracts, with applications in various fields, is also presented and discussed.
Incidência de ocratoxina A em diferentes fra??es do café (Coffea arabica L.): bóia, mistura e varri??o após secagem em terreiros de terra, asfalto e cimento
Batista, Luís Roberto;Chalfoun, Sara Maria;
Ciência e Agrotecnologia , 2007, DOI: 10.1590/S1413-70542007000300030
Abstract: the ochratoxin incidence was studied in coffee it mixes, it "bóia" and "varri??o" dry in three yard types: earth, cement and asphalt. 238 samples were analyzed collected in 11 municipal districts of the south of minas gerais state, being 35 "bóia", 97 - it mixes and 106 varri??o. of the analyzed samples, in 40% the ochratoxin a presence it was not detected, in 74 samples, 31%, ochratoxin a presence were detected the in levels that varied from 0,1 to 5,0 μg/kg of coffee beans. these results demonstrate that in 169 samples (71%) analyzed they would be inside of the limits in study of the european legislation that regulates the maximum concentration of ochratoxin a in coffee beans toasted. the species of identified aspergillus as producing of ochratoxin a were aspergillus ochraceus, a. sclerotiorum and a. sulphureus. the ochratoxin a concentration levels in coffee beans was larger in the fraction varri??o and in the fractions bóia and it mixes, droughts in earth yard. the results of this study conclude that the earth yard increases the risk of contamination with ochratoxin a in coffee beans. the fraction varri??o due to the exhibition risks the ochratoxin a, it should be reduced through the adoption of good agricultural practices and not to be used for ends of human and animal consumption.
Attitudes of Implanting Physicians about Cardiac Rhythm Management Devices and Their Features
Darryl A. Elmouchi,Nagib Chalfoun,Andre Gauri
ISRN Cardiology , 2013, DOI: 10.1155/2013/247586
Abstract: Modern cardiac rhythm management systems have become increasingly complex. The decision on which specific system to implant in a given patient often rests with the implanting physician. We conducted a multiple-choice survey to assess the opinions and preferences of cardiologists and electrophysiologists who implant and follow cardiac rhythm management systems. Reliability and battery longevity were viewed as the most important characteristics in device selection. Patient characteristics which most affected device choice were pacing indication and life expectancy. Remote technology was used in 47% of pacemaker patients, 64% of ICD patients, and 65% of CRT-D patients, with wireless (radiofrequency) remote patient monitoring associated with higher patient compliance rates (74% versus 64%, resp.). Wireless remote patient management with alerts for atrial tachyarrhythmias was felt to be important by 76% of respondents. When choosing an MR-conditional device, physicians deemed patients with prior orthopedic problems, a history of cancer, or neurological disorders to be more likely to require a future MRI. Device longevity and reliability remain the most important factors which influence device selection. Wireless remote patient monitoring with alerts is considered increasingly important when choosing a specific cardiac rhythm management system to implant. 1. Introduction Modern cardiac rhythm management (CRM) devices range from single-chamber pacemakers to implantable cardioverter-defibrillators (ICDs) with cardiac resynchronization therapy (CRT). The decision of which device to implant in a given patient often rests with the implanting physician. Over the past decade, these devices have increased not only in number, but also in features offered; for that reason, many factors influence device selection. We report here on results of a survey conducted among electrophysiologists (EPs) and cardiologists aimed at determining factors that influence device selection for their patients. A major recent breakthrough in cardiac rhythm management has been the advent of remote technology, which today is available in pacemakers as well as ICD and CRT-D systems. Remote technology today includes “remote follow-up,” in which data can be periodically downloaded from the device, either through patient interaction with a transmitter system (inductive systems) or automatically (wireless) with no patient participation. Remote follow-up allows clinics to perform periodic routine patient check-ups without the need for an in-clinic visit. Wireless systems enable the further
Influência do processamento por via úmida e tipos de secagem sobre a composi??o, físico química e química do café (Coffea arabica L).
Santos, Mariá Auxiliadora;Chalfoun, Sára Maria;Pimenta, Carlos José;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000100030
Abstract: coffee (coffea arabica l.) is an important brazilian export product, being part of the eating habit in several countries. its production has experienced technological transformations, with the aim at adding quality values to the product destined to internal as well as to external market. the export of coffee and food products must adjust to the quality programs established by international political agreements. in this context, this work was carried out to verify the influence of the wet processing using different drying types on the obtentainment of the husked coffee cherry on the chemical and physicochemical composition of the coffee. there was influence of the preparation and the drying type methods on the main studied characteristics. the peeled red cherry coffee presented differences in the main chemical and physicochemical indicators, with a superiority in the preparation method with exclusive drying on the patio, in several aspects. reduction in the electric conductivity and potassium leaching was observed as well as increase in the polyphenoloxidase activity.
Controle químico da ferrugem (Hemileia vastatrix Berk & Br.) do cafeeiro através de diferentes esquemas de aplica??o
Chalfoun, Sára Maria;Carvalho, Vicente Luiz de;
Pesquisa Agropecuária Brasileira , 1999, DOI: 10.1590/S0100-204X1999000300006
Abstract: the present work was developed to test different available coffee rust chemical control schemes during the period of 1994 to 1996, at s?o sebasti?o do paraíso, mg, brazil. the treatments were performed by preventive schemes, based on copper fungides (copper oxycloride and copper oxide) curative ones based in systemic fungicides (triazol chemical group) and mixed ones (association of curatives and preventive schemes). the application periods were previously fixed. the result obtained showed that: a) the coffee rust control measures applied at previously periods have permited the increase of disease levels at the end of its cycle; b) the systemic fungicide triadimenol 1,5%, associated with the insecticide disulfoton 7,5%, granulate formulation, applied to the soil in december at 40 kg/ha of the commercial product was the only treatment that has maintened low levels of coffee rust during the disease cycle, and c) the effect of treatments applied to the soil, triadimenol and cyproconazole, was improved by the association with the insecticide disulfoton, enhancing the coffee rust control.
Environmental stress upon hepatopancreatic cells of freshwater prawns (Decapoda: Caridea) from the floodplain of Paraná River  [PDF]
Pablo Collins
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.27094
Abstract: In order to evaluate the influence of stressed environments on hepatopancreatic cells of fre- shwater prawns, Macrobachium borellii Nobili, 1896 and Palaemonetes argentinus Nobili 1901, (Crustacea, Decapoda, Palaemonidae) were collected at three different aquatic environments with different relationship to urban development in Argentina. Furthermore the effects of several cypermethryn concentration on hepa- topancreatic cell of M. borellii and P. argentinus were evaluated in a laboratory assays. The “N° 1” lake (Santa Fe Argentina) which is more affected by the anthropogenic pressure and “Don Felipe” lake which is still not strongly by human activities were the studied sites from the floodplain of Paraná river. While Alejandra lake was the intermedia effects sites. Different damaged ultra-structures were found in F- and R-cells of prawns in the stressed lake. The predominant features were: disrupted the microvillous border, swelled mitochondria, reduction of endoplasmic reticulum, dyctiosomes, glycoproteins, desna-turalization of vacuole membrane and premature autolysis. Moreover the F-cell number was higher in the environment near to city than in the others sites. Similar effects were observed in the cypermethryn assays. The observations clearly indicate that the ultrastructure of midgut gland in the both palaemonids varies depending on the site from which animals are collected and the biocid presence. So, in this case it can be stated that the hepatopancreas histology of fre- shwater prawns is a good tool to monitor the impact of a stressed environment upon freshwater prawns.
Seletividade de fungicidas cúpricos e sistêmicos sobre o fungo Cladosporium cladosporioides em cafeeiro
Chalfoun, Sára Maria;Cunha, Rodrigo Luz da;Carvalho, Vicente Luiz de;Nogueira, Denismar Alves;
Summa Phytopathologica , 2007, DOI: 10.1590/S0100-54052007000100016
Abstract: the occurrence of cladosporium cladosporioides on coffee fruits is frequently and coincides with the control of others diseases in coffee plants. the fungus cladosporium sp. has been found associated with coffee of good quality; therefore, it is important to use of selective fungicides to preserve it. on the study, six years old, coffee plants cv 'acaiá cerrado mg 1474' were selected and sprayed with cupric and systemic fungicides alone or associated copper oxichloride (50% of metallic copper). commercial 'calda vi?osa' was used as copper products and epoxiconazole as a systemic product. the incidence of cladosporium cladosporioides was evaluated four times using a scale. it was verified that on the treatments with the fungicide epoxiconazole applied isolate or in combination with copper fungicide the fungus was found at low levels but increased until may. on the treatments with copper fungicides the fungus incidence was high since may indicating that it was not affected or even was favored by previous applications of copper fungicides.
Multivariate analysis of sensory characteristics of coffee grains (Coffea arabica L.) in the region of upper Paranaíba
Pereira, Marcelo Cláudio;Chalfoun, Sara Maria;Carvalho, Gladyston Rodrigues de;Savian, Taciana Villela;
Acta Scientiarum. Agronomy , 2010, DOI: 10.4025/actasciagron.v32i4.4283
Abstract: this study aimed to examine the sensory characteristics of the grains of 21 cultivars of coffea arabica l. and coffea canephora pierre from the essays of genetic improvement of epamig, located in patrocínio municipality, minas gerais state, where they were collected through cloths stripping method and washed. subsequently to dry (11 to 12% moisture b.u.), we obtained the coffee designated as "natural". the evaluated varieties were: acaiá cerrado mg 1474; bourbon vermelho daterra; catiguá mg 1; catiguá mg 2; catuaí amarelo iac 62; catuaí vermelho iac 15; h 419-3-1-4-2; h 419-6-2 -5-2; h 419-6-2-5-3; h 419-6-2-7-3 vermelho; h 493-1-2-10; h 514-7-10-1 vermelho; h 514-7-10-6; h 515-4-2-2; h 518-3-6-1; icatú amarelo iac 3282; mundo novo 379-19; mundo novo iac 376-4; rubi mg 1192; sacramento mg 1 and topázio mg 1190, from 2005/2006 and 2006/2007 seasons. the cultivars according to the first principal component with notes above 80 points, regarded as superior drink according to attributes with the highest scores (flavor, sweetness, balance, acidity, clean drink, and aspect) were: catiguá mg2, rubi mg 1192, 514-7-10-6 h, h 419-3-1-4-2, h 419-6-2-5-2, 493-1-2-10 h, h 514-7-10-1 vermelho, catiguá mg1, sacramento mg1, 419-6-2-5-3 h, h 515-9-2-2 and catuaí amarelo iac 62.
Inquérito sobre o consumo de alimentos possíveis de contamina??o por micotoxinas na ingesta alimentar de escolares da cidade de Lavras, MG
Silva, Rozane Aparecida da;Chalfoun, Sara Maria;Silva, Marcelo Augusto Mendes da;Pereira, Marcelo Cláudio;
Ciência e Agrotecnologia , 2007, DOI: 10.1590/S1413-70542007000200026
Abstract: the present work was intended to investigate the feeding of students at school age from four state and private network schools of the town of lavras, mg, supposedly contaminated with mycotoxins . the sample universe comprised elementary school 1st and 2nd grade students amounting to 197 students. the evaluation of the students' consumption was performed by utilizing two sorts of dietary inquires: the 24-hour recordatory and the feeding frequency questionnaire (ffq). in possession of the data concerning the 24-hour recordatory and the ffq, promoted a selection among the quoted foods, characterizing them as foods with greater potential of risk as regards the contamination with mycotoxins. the descriptive analyses of the population of students at school indicated a population with a good sample distribution as related with sex with 45.2% ( boys) and 54.8% (girls). no relationship between degree of education of the mothers and the feeding standard of the students correspondent to the 1st degree of elementary teaching. out of the feeds selected in the group of mycotoxin contamination risk, it was found that 49.7% of the children interviewed presented a intake superior to 72.6% of its total caloric value (tcv) obtained from feeds of that group although they have been observed dissimilarities among the schools with relation to the feeds ingested. the analyses of the individual energy consumption presented a risk intake of foods above 72.5%, 41.5% being stood for at school a, 61% at school b, 33.3% at school c and 64.7% at school d. it follows, in this research, that the population presents a profile of high intake of foods considered of risk for mycotoxins, existing the need of adequacy of the diet, aiming to reduce the exposition to that risk.
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