2,837 research outputs found

    A reflective characterisation of occasional user

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    This work revisits established user classifications and aims to characterise a historically unspecified user category, the Occasional User (OU). Three user categories, novice, intermediate and expert, have dominated the work of user interface (UI) designers, researchers and educators for decades. These categories were created to conceptualise user's needs, strategies and goals around the 80s. Since then, UI paradigm shifts, such as direct manipulation and touch, along with other advances in technology, gave new access to people with little computer knowledge. This fact produced a diversification of the existing user categories not observed in the literature review of traditional classification of users. The findings of this work include a new characterisation of the occasional user, distinguished by user's uncertainty of repetitive use of an interface and little knowledge about its functioning. In addition, the specification of the OU, together with principles and recommendations will help UI community to informatively design for users without requiring a prospective use and previous knowledge of the UI. The OU is an essential type of user to apply user-centred design approach to understand the interaction with technology as universal, accessible and transparent for the user, independently of accumulated experience and technological era that users live in

    Anomalous Hall effect in the coplanar antiferromagnetic coloring-triangular lattice

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    We study the anomalous Hall effect on the antiferromagnetic coloring-triangular lattice with a coplanar magnetic configuration in the presence of a spin-orbit interaction. The effect of the spin-orbit coupling is included at an effective level as a rotation of the electronic spin as the electrons hop from site to site. Our result reveals that a finite Hall conductivity in the planar 120 structure takes place if a finite spin-orbit coupling is present. A quantized Hall conductivity occurs at global band gaps resulting from the topologically nontrivial band structure.Fil: Duran, A. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física de Líquidos y Sistemas Biológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física de Líquidos y Sistemas Biológicos; ArgentinaFil: Osorio, Santiago Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Sturla, Mauricio Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física de Líquidos y Sistemas Biológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física de Líquidos y Sistemas Biológicos; Argentin

    Adverse social determinats and risk for congenital anomalies

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    INTRODUCCIÓN: Diferentes trabajos han relacionando condiciones sociales adversas a nivel familiar y regional con resultados perinatales (mortalidad neonatal, bajo peso y prematuridad); sin embargo, pocos estudiaron el efecto de la pobreza sobre anomalías congénitas. Objetivo. Evaluar el riesgo de ocurrencia de 25 anomalías congénitas y determinantes sociales adversos según el nivel socioeconómico de la familia y de la región. POBLACIÓN Y MÉTODOS. Estudio caso-control exploratorio, en el que se utilizaron datos del Estudio Colaborativo Latinoamericano de Malformaciones Congénitas (ECLAMC). La muestra consistió en 3786 recién nacidos vivos con una única malformación y 13 344 controles, seleccionados entre 546 129 nacimientos, ocurridos en 39 hospitales de Argentina durante el período 1992-2001. Se estimaron los riesgos (OR) directos, indirectos (a través de la región de residencia) y la interacción entre el nivel socioeconómico individual y residencial para cada uno de los 25 defectos congénitos. RESULTADOS: Los defectos labio leporino con/sin paladar hendido (OR= 1,43) y comunicación interventricular (OR= 1,38) mostraron un riesgo significativamente mayor en el nivel socioeconómico más bajo. Los niveles socioeconómicos bajos se asociaron de manera significativa con una mayor frecuencia de consanguinidad parental, ancestros nativos, edad materna menor de 19 años, más de 4 embarazos, bajo número de visitas prenatales y residencia en regiones desfavorables. CONCLUSIÓN: La fisura labial con o sin paladar hendido y los defectos del tabique interventricular estuvieron asociados significativamente con un nivel socioeconómico más bajo. La falta de planificación familiar, de control prenatal y la exposición a agentes ambientales o teratógenos pueden explicar estos hallazgos.INTRODUCTION: Different studies have related familiar and regional adverse social conditions to perinatal outcome (neonatal mortality, low birth weight and prematurity); however, few studies have studied the effect of poverty on congenital anomalies. OBJECTIVE: To assess the hazard ratio of 25 congenital anomalies and adverse social determinants as per the socioeconomic level of families and regions. POPULATION AND METHODS: Exploratory, case-control study using data from the Latin-American Collaborative Study of Congenital Malformations (Estudio Colaborativo Latinoamericano de Malformaciones Congenitas, ECLAMC). The sample consisted of 3786 live newborn infants with a single malformation and 13,344 controls selected among 546,129 births occurred in 39 hospitals from Argentina in the 1992-2001 period. Both direct and indirect (residence) risks (OR) were estimated, together with the interaction between the individual and residential socioeconomic levels for each of the 25 congenital anomalies. RESULTS: Cleft lip with/without cleft palate (OR= 1.43) and ventricular septal defect (OR= 1.38) showed a significantly higher risk in the lower socioeconomic level. Low socioeconomic levels were significantly associated with a higher frequency of parental sibship (blood relationship); native descent; maternal age younger than 19 years old; more than four pregnancies; a low number of antenatal care visits; and residence in deprived regions. CONCLUSION: Cleft lip with/without cleft palate and ventricular septal defects were significantly associated with a lower socioeconomic level. Lack of family planning and antenatal care; and exposure to environmental or teratogenic agents may account for these findings.Fil: Pawluk, Mariela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Campaña, Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; ArgentinaFil: Gili, Juan Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; ArgentinaFil: Comas, Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; ArgentinaFil: Gimenez, Lucas Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; ArgentinaFil: Villalba, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Scala, Sandra C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Poletta, Fernando Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina. Instituto Nacional de Genética Médica Poblacional; BrasilFil: López Camelo, Jorge Santiago. Instituto Nacional de Genética Médica Poblacional; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentin

    Parsimonious scenario for the emergence of viroid-like replicons de novo

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    This article belongs to the Special Issue Viroid-2018: International Conference on Viroids and Viroid-Like RNAs.Viroids are small, non-coding, circular RNA molecules that infect plants. Different hypotheses for their evolutionary origin have been put forward, such as an early emergence in a precellular RNA World or several de novo independent evolutionary origins in plants. Here, we discuss the plausibility of de novo emergence of viroid-like replicons by giving theoretical support to the likelihood of different steps along a parsimonious evolutionary pathway. While Avsunviroidae-like structures are relatively easy to obtain through evolution of a population of random RNA sequences of fixed length, rod-like structures typical of Pospiviroidae are difficult to fix. Using different quantitative approaches, we evaluated the likelihood that RNA sequences fold into a rod-like structure and bear specific sequence motifs facilitating interactions with other molecules, e.g., RNA polymerases, RNases, and ligases. By means of numerical simulations, we show that circular RNA replicons analogous to Pospiviroidae emerge if evolution is seeded with minimal circular RNAs that grow through the gradual addition of nucleotides. Further, these rod-like replicons often maintain their structure if independent functional modules are acquired that impose selective constraints. The evolutionary scenario we propose here is consistent with the structural and biochemical properties of viroids described to date.P.C. is supported by a Ramón Areces Foundation Postdoctoral Fellowship. The Spanish Ministerio de Ciencia, Innovación y Universidades-FEDER funds of the European Union support Projects BASIC (PGC2018-098186-B-I00, J.A.C. and P.C.), MiMevo (FIS2017-89773-P, S.M.), and EvolSysVir (BFU2015-65037-P, S.F.E.)

    Situación actual de la prevención del cáncer de piel: una revisión siste

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    Skin cancer deaths continue to rise despite the implementation of numerous preventive campaigns and programs. The aim of this systematic review was to evaluate reviews of primary and secondary skin cancer prevention strategies as reported over the past 10 years. We analyzed 63 systematic reviews and meta-analyses: 30 (46.6%) addressing primary interventions and 35 (55.6%) addressing secondary interventions. Two of the reviews covered both. The most widely reported primary prevention approaches were education programs (63.3%), followed by risk modeling to identify individuals at high risk for melanoma (17.6%), and the promotion of sunscreen use (11.8%). The most widely reported secondary prevention measures concerned imaging systems for early skin cancer detection (40%), smartphones and new technologies (22.9%), and visual diagnosis in population-based screening (17.4%). The most effective measures were primary prevention education programs to improve sun protection habits.La mortalidad por cáncer de piel continúa aumentando a pesar de las numerosas intervenciones dedicadas a su prevención. El objetivo de esta revisión es estudiar la situación de la prevención primaria y secundaria del cáncer de piel en los últimos 10 a˜nos. Se incluye un total de 63 revisiones, 30 (46,6%) revisiones incluyeron estrategias de prevención primaria y 35 (55,6%) de prevención secundaria, incorporando 2 de las revisiones información sobre ambos tipos de estrategias. Para la prevención primaria, las medidas más estudiadas fueron losprogramas educativos (63,3%), seguidos de la creación de modelos para identificar a personascon alto riesgo de desarrollar un melanoma (17,6%) y la promoción del uso de fotoprotectores(11,8%). Los sistemas de toma de imagen para el diagnóstico precoz del cáncer de piel (40%),seguidos por el empleo de smartphones y nuevas tecnologías (22,9%), así como el diagnósticovisual como cribado poblacional (17,4%), fueron las medidas de prevención secundaria másevaluadas. De todas las medidas revisadas, las estrategias de prevención primaria centradas enprogramas educativos para mejorar los hábitos de fotoprotección fueron las que resultaron másefectivas

    Downregulation of snail by DUSP1 impairs cell migration and invasion through the inactivation of JNK and ERK and is useful as a predictive factor in the prognosis of prostate cancer

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    Dual specificity phosphatase 1 (DUSP1) is crucial in prostate cancer (PC), since its expression is downregulated in advanced carcinomas. Here, we investigated DUSP1 effects on the expression of mesenchymal marker Snail, cell migration and invasion, analyzing the underlying mechanisms mediated by mitogen‐activated protein kinases (MAPKs) inhibition. To this purpose, we used different PC cells overexpressing or lacking DUSP1 or incubated with MAPKs inhibitors. Moreover, we addressed the correlation of DUSP1 expression with Snail and activated MAPKs levels in samples from patients diagnosed with benign hyperplasia or prostate carcinoma, studying its implication in tumor prognosis and survival. We found that DUSP1 downregulates Snail expression and impairs migration and invasion in PC cells. Similar results were obtained following the inhibition of c‐Jun N‐terminal kinase (JNK) and extracellular‐signal‐regulated kinase (ERK). In clinical samples, we evidenced an inverse correlation between DUSP1 expression and Snail levels, which are further associated with JNK and ERK activation. Consequently, the pattern DUSP1high/activated JNKlow/activated ERKlow/Snaillow is associated with an overall extended survival of PC patients. In summary, the ratio between DUSP1 and Snail expression, with additional JNK and ERK activity measurement, may serve as a potential biomarker to predict the clinical outcome of PC patients. Furthermore, DUSP1 induction or inhibition of JNK and ERK pathways could be useful to treat PCD.M.-M. was recipient of grants from UAM (“Post-Master Program of Dpt. Biochemistry) and from Comunidad de Madrid (“Ayudas para la contratación de investigadores predoctorales y postdoctorales, ref. PEJD-2018-PRE/BMD-8987). P.B. was recipient of a grant from Comunidad de Madrid (“Atracción al Talento Investigador”, ref. 2017-T1/BMD-5704

    A micromachined thermoelectric sensor for natural gas analysis: Multivariate calibration results

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    The potential use of a micromachined thermopile based sensor device for analyzing natural gas is explored. The sensor consists of a thermally isolated hotplate, which is heated by the application of a sequence of programmed voltages to an integrated heater. Once the hotplate reaches a stationary temperature, the thermopile provides a signal proportional to the hotplate temperature. These signals are processed in order to determine different natural gas properties. Sensor response is mainly dependent on the thermal conductivity of the surrounding gas at different temperatures. Seven predicted properties (normal density, superior heating value, Wobbe index and the concentrations of methane, ethane, carbon dioxide and nitrogen) are calibrated against sensor signals by using multivariate regression, in particular partial least squares. Experimental data have been used for calibration and validation. Results show property prediction capability with reasonable accuracy except for prediction of carbon dioxide concentration. A detailed uncertainty analysis is provided to better understand the metrological limits of the system. These results imply for the first time the possibility of designing unprecedented low-cost natural gas analyzers. The concept may be extended to other constrained gas mixtures (e.g. of a known number of components) to enable low-cost multicomponent gas analyzers

    Comparison of the design and methodology of Phase 3 clinical trials of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and dolutegravir-based dual therapy (DTG) in HIV: a systematic review of the literature

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    Introduction: Current recommended antiretroviral regimens include a combination of two (dual; DT) or three (triple; TT) antiretroviral drugs. This study aims to determine whether the quality of evidence from clinical trials of dolutegravir (dolutegravir/lamivudine [DTG/3TC] or dolutegravir/rilpivirine [DTG/RPV]) is methodologically comparable to that of clinical trials conducted with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). Areas covered: A systematic review of the medical literature was carried out in PubMed without date or language restrictions, following the PRISMA guidelines. All aspects of the methodological design of phase 3 randomized clinical trials (RCTs) of DT and TT, evaluated by the European Medicines Agency (registration trials), were reviewed. The quality of clinical trials was assessed using the Jadad scale. Expert opinion: The search identified 5, 3 and 2 phase 3 RCTs with BIC/FTC/TAF, DTG/3TC and DTG/RPV, respectively, that met the inclusion criteria. The designs would not be comparable due to differences in pre-randomization losses, blinding, patient recruitment, as well as differences in methodological quality, with the average score of the RCTs conducted with BIC/FTC/TAF, DTG/3TC and DTG/RPV being 4.2 (high quality), 3.0 (medium quality) and 3.0 (medium quality), respectively. Due to methodological differences between the BIC/FTC/TAF, DTG/3TC and DTG/RPV RCTs, the results of these are not comparable

    Early embryonic brain development in rats requieres the trophic influence of cerebrospinal fluid

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    Producción CientíficaParticularly evCerebrospinal fluid has shown itself to be an essential brain component during development. This is parident at the earliest stages of development where a lot of research, performed mainly in chick embryos, supports the evidence that cerebrospinal fluid is involved in different mechanisms controlling brain growth and morphogenesis, by exerting a trophic effect on neuroepithelial precursor cells (NPC) involved in controlling the behaviour of these cells. Despite it being known that cerebrospinal fluid in mammals is directly involved in corticogenesis at fetal stages, the influence of cerebrospinal fluid on the activity of NPC at the earliest stages of brain development has not been demonstrated. Here, using ‘‘in vitro’’ organotypic cultures of rat embryo brain neuroepithelium in order to expose NPC to or deprive them of cerebrospinal fluid, we show that the neuroepithelium needs the trophic influence of cerebrospinal fluid to undergo normal rates of cell survival, replication and neurogenesis, suggesting that NPC are not self-sufficient to induce their normal activity. This data shows that cerebrospinal fluid is an essential component in chick and rat early brain development, suggesting that its influence could be constant in higher vertebrates

    Graphene Reflectarray Metasurface for Terahertz Beam Steering and Phase Modulation

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    We report a THz reflectarray metasurface which uses graphene as active element to achieve beam steering, shaping and broadband phase modulation. This is based on the creation of a voltage controlled reconfigurable phase hologram, which can impart different reflection angles and phases to an incident beam, replacing bulky and fragile rotating mirrors used for terahertz imaging. This can also find applications in other regions of the electromagnetic spectrum, paving the way to versatile optical devices including light radars, adaptive optics, electro-optical modulators and screens
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