Frequency dynamics of gain-switched injection-locked semiconductor lasers

The frequency dynamics of gain-switched singlemode semiconductor lasers subject to optical injection is investigated. The requirements for low time jitter and reduced frequency chirp operation are studied as a function of the frequency mismatch between the master and slave lasers. Suppression of the power overshoot, typical during gain-switched operation, can be achieved for selected frequency detunings

Correction to: Collaborative immersive authoring tool for real-time creation of multisensory VR experiences

In the original publication, Figs. 1 and 2 were interchange and the citation of Fig. 1 in the third paragraph of section 2.2 Authoring tools for multisensory VR experiences should be removed. The citation of Fig. 2 in section 3.1 System architecture should be changed to Fig. 1 and the citation of Fig. 1 in the same section should be change to Fig. 2. Also, the acknowledgement is missing in the original publication. The corrected figures and acknowledgement are presented in this erratum.This work was also partially supported by the project “DOUROTUR, Turismo e Inovação Tecnológica no Douro/NORTE-01-0145-FEDER-000014” financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF). All the works were conducted at INESC TEC’s MASSIVE VR Laboratory.info:eu-repo/semantics/publishedVersio

Collaborative immersive authoring tool for real-time creation of multisensory VR experiences

With the appearance of innovative virtual reality (VR) technologies, the need to create immersive content arose. Although there are already some non-immersive solutions to address immersive audio-visual content, there are no solutions that allow the creation of immersive multisensory content. This work proposes a novel architecture for a collaborative immersive tool that allows the creation of multisensory VR experiences in real-time, thus promoting the expeditious development, adoption, and use of immersive systems and enabling the building of custom-solutions that can be used in an intuitive manner to support organizations’ business initiatives. To validate the presented proposal, two approaches for the authoring tools (Desktop interface and Immersive interface) were subjected to a set of tests and evaluations consisting of a usability study that demonstrated not only the participants’ acceptance of the authoring tool but also the importance of using immersive interfaces for the creation of such VR experiences.info:eu-repo/semantics/publishedVersio

Telegenetics: application of a tele-education program in genetic syndromes for Brazilian students

With the high occurrence of genetic anomalies in Brazil and the manifestations of communication disorders associated with these conditions, the development of educative actions that comprise these illnesses can bring unique benefits in the identification and appropriate treatment of these clinical pictures. Objective The aim of this study was to develop and analyze an educational program in genetic syndromes for elementary students applied in two Brazilian states, using an Interactive Tele-education model. Material and Methods The study was carried out in 4 schools: two in the state of São Paulo, Southeast Region, Brazil, and two in the state of Amazonas, North Region, Brazil. Forty-five students, both genders, aged between 13 and 14 years, of the 9th grade of the basic education of both public and private system, were divided into two groups: 21 of São Paulo Group (SPG) and 24 of Amazonas Group (AMG). The educational program lasted about 3 months and was divided into two stages including both classroom and distance activities on genetic syndromes. The classroom activity was carried out separately in each school, with expository lessons, graphs and audiovisual contents. In the activity at a distance the educational content was presented to students by means of the Interactive Tele-education model. In this stage, the students had access a Cybertutor, using the Young Doctor Project methodology. In order to measure the effectiveness of the educational program, the Problem Situation Questionnaire (PSQ) and the Web Site Motivational Analysis Checklist adapted (FPM) were used. Results The program developed was effective for knowledge acquisition in 80% of the groups. FPM showed a high satisfaction index from the participants in relation to the Interactive Tele-education, evaluating the program as "awesome course". No statistically significant differences between the groups regarding type of school or state were observed. Conclusion Thus, the Tele-Education Program can be used as a tool for educational purposes in genetic syndromes of other populations, in several regions of Brazil

Adaptation and validation of the ITC - Sense of Presence Inventory for the Portuguese language

This investigation concerns the translation and validation of the ITC - Sense of Presence Inventory (ITC-SOPI) for the Portuguese-speaking population (in Europe), estimating the validity of the content and concepts and the maintenance of an equivalent semantics. It also sought to verify its psychometric properties, namely its factorial validity and internal consistency. The sample consisted of 459 individuals, 274 males and 185 females. The fidelity of the subscales varied between 0.67 and 0.89. Confirmatory factor analysis revealed a theoretical model of 35 items, divided by four factors. After fixing some of the residual errors between items, the following adjustment indexes were calculated: χ2/df = 2.301; goodness fit index = 0.860; comparative fitness index=0.889; root mean square error of approximation=0.053; Akaike’s information criterion=1420. Based on the observed results and the robustness of the sample size used, the obtained theoretical model shows that the ITC-SOPI is recommended to measure presence in virtual reality research projects with samples of Portuguese language speakers.This work is financed by the ERDF European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia within project POCI-01-0145-FEDER-028618 entitled PERFECT - Perceptual Equivalence in virtual Reality For authEntiC Training. All the works were conducted at INESC TEC’s MASSIVE Virtual Reality Laboratory.info:eu-repo/semantics/publishedVersio

Multimodality imaging approach for combined central retinal vein and artery occlusion: the role of optical coherence tomography angiography

Combined central retinal artery and vein occlusion is an uncommon vascular pathology that can cause severe and permanent visual impairment. Optical coherence tomography angiography (OCTA) is a newly available, noninvasive imaging technique that can potentially improve understanding of the structural and vascular implications and prognosis of this infrequent pathology. The present report describes the principal clinical findings in a case of combined central retinal artery and vein occlusion, as detected by the different imaging modalities available in a tertiary referral hospital. OCTA wide-field montage images identified an extensive area of nonperfusion on the macula with involvement of the entire retina at nearly 360°. We observed the most severe nonperfusion in the deep capillary plexus, while perfusion of the choriocapillaris was unaffected. Meanwhile, fluorescein angiography (FA) findings revealed a delay in perfusion rate with marked nonperfusion areas in the peripheral retina at 360°. We identified that the wide-field OCTA montage permitted visualization of a similar or wider peripheral retinal area compared with FA. Therefore, OCTA is potentially useful for assessment of the global retinal nonperfusion status at baseline and during follow-up, with the added advantage of being a noninvasive techniqueThis work was supported in part by the Mutua Madrileña project (Ref. 2017/365)S

School performance of students with cleft lip and palate in their teachers' point of view

OBJETIVO: Verificar o desempenho escolar de alunos com fissura labiopalatina sem anomalias associadas e correlacionar os possíveis fatores interferentes, segundo a opinião dos professores de 1ª a 8ª séries do Ensino Fundamental. MÉTODOS: A metodologia deste estudo compreendeu duas etapas. Na primeira etapa foi realizada uma análise retrospectiva de 61 prontuários de pacientes com fissura labiopalatina sem anomalias associadas, regularmente matriculados em classes de 1ª a 8ª séries do Ensino Fundamental. Esta etapa foi realizada a fim de caracterizar o perfil dos mesmos, quanto ao gênero, nível socioeconômico, tipo de fissura, timpanometria e inteligibilidade de fala. A segunda etapa incluiu a aplicação de um questionário com o intuito de verificar a percepção dos professores sobre o desempenho escolar destes alunos. Os resultados foram analisados estatisticamente. RESULTADOS: A análise dos questionários mostrou que somente 20,7% dos professores consideraram que seus alunos com fissura labiopalatina têm desempenho escolar abaixo da média da classe. Não foi encontrada diferença significativa na associação entre o desempenho escolar e os possíveis fatores interferentes, a saber, gênero, nível socioeconômico, tipo de fissura, timpanometria e inteligibilidade de fala. CONCLUSÃO: O desempenho escolar da maioria dos alunos com fissura labiopalatina sem anomalias associadas foi percebido pelos respectivos professores como satisfatório, ou seja, dentro da média, considerando os demais alunos de sua sala de aula.PURPOSE: To assess the school performance of students from 1st to 8th grade of Elementary School with cleft lip and palate without associated anomalies, and to correlate possible interfering factors, according to the opinion of their teachers. METHODS: The methodology of this study was divided into two stages. The first stage was a retrospective analysis of 61 medical records of patients with cleft lip and palate without associated anomalies, regularly enrolled in Elementary School (1st to 8th grades). The first stage had the aim to characterize the profile of the participants regarding gender, socioeconomic status, type of cleft, tympanometry, and speech intelligibility. The second stage involved the application of a questionnaire to be answered by the teachers of these subjects, in order to verify their perceptions regarding the school performance of these students. Results were statistically analyzed. RESULTS: The analysis of questionnaires showed that only 20.7% of the teachers believed that their students with cleft lip and palate have school performance below the average of the class. There was no significant difference in the association between school performance and the possible intervening factors, such as gender, socioeconomic status, type of cleft, tympanometry, and speech intelligibility. CONCLUSION: The school performance of most students with cleft lip and palate without associated anomalies was considered satisfactory by their teachers, that is, within the average, considering the performance of other students in their classes

Riego, densidad de plantas y fertilización nitrogenada en producción de maíz híbrido en Zacatecas

In the semiarid highlands of Mexico, rainfall has an erratic distribution and therefore, maize and bean yields are low. In this region the rainfall season may be classified as “normal” or “delayed”, according to the onset of the rainy season. Whenever sowing time has to be delayed due to the late onset of rains, the risk of drought and crop damage by low temperatures increases. The objective of this research was to evaluate and promote possible alternative crops under normal and late rainfall, with and without supplemental irrigation to reduce production risks in rainfed areas. The experiment was established in two locations, Sandovales and Montoya in the county of El Llano, Aguascalientes, during 1999 and 2000. Three factors were evaluated: a) alternative crops: barley, oat, triticale, wheat, and chickpea with dry beans and maize as controls; b) sowing dates: normal and delayed; and c) soil moisture regimes: rainfall with and without supplemental irrigation. In both years the onset of rains was normal. Dry matter and grain yield were recorded. Results indicated that soil moisture conditions were more favorable in the first sowing date in both years and sites, which was reflected in higher dry matter and grain yield; a similar response was observed with supplemental irrigation in both planting dates. The alternative crops showed tolerance to low temperatures. Maize for forage production is a good option under normal planting with or without supplemental irrigation, and although it is still a good option under delayed planting, oat or triticale can also be good alternatives. Crops having a long growth cycle such as maize and chickpeas have a higher risk for grain production under delayed planting dates. Dry beans and oat for grain production showed good response under normal planting with or without supplemental irrigation.En la región del Altiplano Semiárido de México las lluvias tienen distribución errática y el rendimiento del maíz y frijol es bajo. El temporal, según el inicio de las lluvias en la región, se puede clasificar en normal y tardío. Las siembras que se realizan en fechas tardías incrementan el riesgo por sequía y por bajas temperaturas durante el desarrollo de los cultivos. El objetivo de la investigación fue evaluar diversos cultivos en temporal normal y tardío, con y sin riego de auxilio, para reducir los riesgos de producción en las áreas de temporal del Altiplano Semiárido de México. Los experimentos se establecieron en Sandovales y Montoya en el municipio de El Llano, Aguascalientes, México, en los ciclos 1999 y 2000. Se evaluaron tres factores: a) cultivos alternativos: cebada, avena, triticale, trigo, garbanzo y los testigos frijol y maíz; b) fechas de siembra: temporal normal y temporal tardío y c) niveles de humedad: temporal solo y temporal más un riego de auxilio. En todos los cultivos se determinó la producción de materia seca y grano. Las condiciones de humedad fueron más favorables en la época de siembra normal en ambos años y sitios, lo que se reflejó en mayor rendimiento de materia seca y grano; una respuesta similar ocurrió con el riego de auxilio en ambas fechas de siembra. Los cultivos alternativos al frijol y maíz mostraron tolerancia a las heladas. El maíz para forraje es una opción para temporal normal con y sin riego de auxilio y también para temporal tardío, aunque puede sustituirse por avena o triticale. Los cultivos de ciclo largo como el maíz y el garbanzo mostraron alto riesgo para producir grano en siembras tardías; el frijol y la avena mostraron buena respuesta en siembras normales con y sin riego suplementario

Assessing presence in virtual environments: adaptation of the psychometric properties of the presence questionnaire to the portuguese populations

Virtual Reality applications have the goal of transporting their users to a given virtual environment (VE). Thus, Presence is a consensual metric for evaluating the VEs’ effectiveness. The present study adapts the Presence Questionnaire (PQ) for the Portuguese-speaking population, maintaining the validity of the contents and concepts, to ascertain the psychometric properties of the instrument.The adaptation to Portuguese was achieved through the standard adaptation process of translation and back-translation process. The sample consisted of 451 individuals (268 males and 183 females). Factor reliability ranged from 0.63 to 0.86. Confirmatory factor analysis produced a theoretical model of 21 items distributed among seven factors, where the covariance between some residual item errors was established. The fit indices obtained were x2/df = 2.077, GFI = 0.936, CFI = 0.937, RMSEA = 0.049, P [RMSEA ≤ 0.05], MECVI = 1.070. Results obtained allowed us to consider that the adapted Portuguese version of the PQ, with 21 items, forms a robust and valid questionnaire whose use is recommended to evaluate Presence in virtual reality research programmes, provided that they use samples of the Portuguese language (Europe).This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation – COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT – Fundação para a Ciência e a Tecnologia within project POCI-01-0145-FEDER-028618 entitled PERFECT – Perceptual Equivalence in virtual Reality For auth- EntiC Training.info:eu-repo/semantics/publishedVersio