6,731 research outputs found
Automatic Sensor-free Affect Detection: A Systematic Literature Review
Emotions and other affective states play a pivotal role in cognition and,
consequently, the learning process. It is well-established that computer-based
learning environments (CBLEs) that can detect and adapt to students' affective
states can enhance learning outcomes. However, practical constraints often pose
challenges to the deployment of sensor-based affect detection in CBLEs,
particularly for large-scale or long-term applications. As a result,
sensor-free affect detection, which exclusively relies on logs of students'
interactions with CBLEs, emerges as a compelling alternative. This paper
provides a comprehensive literature review on sensor-free affect detection. It
delves into the most frequently identified affective states, the methodologies
and techniques employed for sensor development, the defining attributes of
CBLEs and data samples, as well as key research trends. Despite the field's
evident maturity, demonstrated by the consistent performance of the models and
the application of advanced machine learning techniques, there is ample scope
for future research. Potential areas for further exploration include enhancing
the performance of sensor-free detection models, amassing more samples of
underrepresented emotions, and identifying additional emotions. There is also a
need to refine model development practices and methods. This could involve
comparing the accuracy of various data collection techniques, determining the
optimal granularity of duration, establishing a shared database of action logs
and emotion labels, and making the source code of these models publicly
accessible. Future research should also prioritize the integration of models
into CBLEs for real-time detection, the provision of meaningful interventions
based on detected emotions, and a deeper understanding of the impact of
emotions on learning
Herbage Production of Tanzania Grass (\u3cem\u3ePanicum maximum\u3c/em\u3e cv. Tanzania) Submitted to Combinations of Frequencies and Intensities of Grazing by Cattle
Animal production from pastures is a complex process comprising three main stages: herbage growth, consumption by grazing animals and conversion into animal products (Hodgson, 1990). Utilisation is the stage where the grazier finds greater flexibility for management, probably because most processes related to harvest of the produced herbage by the grazing animals are very responsive to manipulation and control of defoliation practices. The objective of this study was to evaluate herbage production of a Panicum maximum cv. Tanzania pasture submitted to combinations of frequencies and intensities of grazing
Fibre Reinforced Polymer (FRP) connectors for Steel Fibre Reinforced Self-Compacting Concrete (SFRSCC) sandwich panels
Insulated sandwich wall panels are frequently composed of external concrete layers,
mechanically connected through metallic connectors, such as trusses. Due to their high
thermal conductivity, these connectors generally cause thermal bridges on the building
envelope. In view of this problem, an innovative system is proposed where FRP connectors
are used together with a thermal insulation layer. Steel Fibre Reinforced Self-Compacting
Concrete (SFRSCC) wythes are also used to obtain panels that are both technically and
economically advantageous. However, to present day there is no experimental data on the
mechanical behaviour of the suggested connections. In this research, an experimental study is
performed to characterize different types of FRP-SFRSCC connections under pull-out tests.
Shear connection behaviour under monotonic loading is evaluated with slip controlled tests.
Embedded and adhesively bonded connection solutions between SFRSCC layers and FRP
connectors are studied.(undefined
Eventos extremos de lluvia y riesgo hidroclimático en zona de La Mata - Pernambuco/Brasil
Intense rains are natural events associated with urban peculiarities that can become sources of danger, worsening the population's living conditions in the city. In Brazil, the scenarios of environmental degradation resulting from social inequalities and poor infrastructure, coupled with the occupation of inappropriate spaces highlight risks and vulnerabilities that often coincide with urban river environments. This article aims to analyze the occurrence of extreme events caused by rainfall in mesoregion Zona da Mata in Pernambuco, Brazil, specifically, the municipalities of Barreiros and Palmares. Furthermore, the risk conditions that led or may lead to disaster areas were studied. The analysis was carried out, firstly by analyzing the descriptive statistics of the time series of precipitation and later the Rain Anomaly Index (RAI) was calculated. Satellite image analysis was then utilized to characterize the pattern of rain and atmospheric dynamics associated with the period of occurrence of selected rainfall events; heavy rainfall concentrated in a short period of time. The main rainfall event of great magnitude for municipalities occurred in June 2010 caused by Eastern wave disturbance, which led to the flooding of rivers and flooding in several cities in the basin of Una and Mundau rivers.Las inundaciones son fenómenos naturales asociados con peculiaridades urbanas se convierten en fuentes de peligro, el empeoramiento de las condiciones de vida de la población en la ciudad. En Brasil, los escenarios de degradación del medio ambiente que resultan de las desigualdades sociales y la infraestructura deficiente, junto con la ocupación de los problemas de espacio de relieve los riesgos y las vulnerabilidades que suelen coincidir con los entornos de los ríos urbanos. Este artículo tiene como objetivo analizar la ocurrencia de eventos extremos causados por las lluvias en mesorregión Zona da Mata, en Pernambuco, Brasil, sobre la base, los municipios de Barreiros y Palmares, está tratando de comprender la dinámica de las lluvias asociadas con el período de ocurrencia de un evento. Además, se investigó las condiciones de riesgo que llevaron o puedan dar lugar a zonas de desastre en el estudiada. Se seleccionaron los datos de lluvia disponible en la Agencia de Pernambuco Agua y Clima y (sistema de monitoreo agrometeorológico. El análisis se llevó a cabo, en primer lugar, las estadísticas descriptivas de las series de tiempo de precipitación, se calculó la tarde del índice de anomalías de lluvia (IAC) y análisis de imágenes de satélite para caracterizar el modelo de la lluvia y la dinámica atmosférica asociados con el período de ocurrencia de eventos de lluvias fuertes lluvias seleccionados, se concentró en un corto período de tiempo. también se llevó a cabo el trabajo de campo para registrar el impacto del evento. el principal evento de gran magnitud para los municipios precipitaciones fue lo que sucedió en junio de 2010 causado por la interrupción de la onda del Este que dio lugar a la inundación de ríos e inundaciones en varias ciudades de la cuenca del río Una y Mundaú
Topological Superconductor from the Quantum Hall Phase: Effective Field Theory Description
We derive low-energy effective field theories for the quantum anomalous Hall
and topological superconducting phases. The quantum Hall phase is realized in
terms of free fermions with nonrelativistic dispersion relation, possessing a
global symmetry. We couple this symmetry with a background gauge field
and compute the effective action by integrating out the gapped fermions. In
spite of the fact that the corresponding Dirac operator governing the dynamics
of the original fermions is nonrelativistic, the leading contribution in the
effective action is a usual Abelian Chern-Simons term. The proximity to
a conventional superconductor induces a pairing potential in the quantum Hall
state, favoring the formation of Cooper pairs. When the pairing is strong
enough, it drives the system to a topological superconducting phase, hosting
Majorana fermions. Even though the continuum symmetry is broken down to
a one, we can forge fictitious symmetries that enable us
to derive the effective action for the topological superconducting phase, also
given by a Chern-Simons theory. To eliminate spurious states coming from the
artificial symmetry enlargement, we demand that the fields in the effective
action are instead of gauge fields. In the case we have to
sum over the bundles in the partition function, which projects
out the states that are not invariants. The corresponding edge
theory is the orbifold, which contains Majorana fermions in
its operator content.Comment: 40 pages, 5 figures, journal versio
RG108 increases NANOG and OCT4 in bone marrow-derived mesenchymal cells through global changes in DNA modifications and epigenetic activation. RG108 increases NANOG and OCT4 through epigenetic activation.
Human bone marrow-derived mesenchymal stem cells (hBMSCs) are important for tissue regeneration but their epigenetic regulation is not well understood. Here we investigate the ability of a non-nucleoside DNA methylation inhibitor, RG108 to induce epigenetic changes at both global and gene-specific levels in order to enhance mesenchymal cell markers, in hBMSCs. hBMSCs were treated with complete culture medium, 50 μM RG108 and DMSO for three days and subjected to viability and apoptosis assays, global and gene-specific methylation/hydroxymethylation, transcript levels' analysis of epigenetic machinery enzymes and multipotency markers, protein activities of DNMTs and TETs, immunofluorescence staining and western blot analysis for NANOG and OCT4 and flow cytometry for CD105. The RG108, when used at 50 μM, did not affect the viability, apoptosis and proliferation rates of hBMSCs or hydroxymethylation global levels while leading to 75% decrease in DNMTs activity and 42% loss of global DNA methylation levels. In addition, DNMT1 was significantly downregulated while TET1 was upregulated, potentially contributing to the substantial loss of methylation observed. Most importantly, the mesenchymal cell markers CD105, NANOG and OCT4 were upregulated being NANOG and OCT4 epigenetically modulated by RG108, at their gene promoters. We propose that RG108 could be used for epigenetic modulation, promoting epigenetic activation of NANOG and OCT4, without affecting the viability of hBMSCs. DMSO can be considered a modulator of epigenetic machinery enzymes, although with milder effect compared to RG108
Productivity of three sugarcane cultivars under dry and drip irrigated management
O objetivo neste trabalho foi estudar o efeito da tecnologia de irrigação por gotejamento, em cultivares de cana-de-açúcar, em dois ciclos de produção (cana-planta e cana-soca). O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições, constituídos pela combinação de três cultivares de cana-de-açúcar: RB867515; RB855536 e SP80-3280, e dois manejos da cultura: sistema de irrigação por gotejamento subterrâneo e sistema de sequeiro, totalizando seis tratamentos. O primeiro ciclo teve duração de 336 dias, ocorrendo precipitação de 1.480 mm. O volume de água disponibilizado pelo sistema de irrigação por gotejamento foi de 400 mm, totalizando 1.880 mm. O segundo ciclo teve duração de 365 dias, cujo volume de água por meio de precipitação foi de 1.394 mm; somados aos 320 mm fornecidos pelo sistema de irrigação, totalizaram 1.714 mm. Ocorreu interação entre manejo e cultivar para as variáveis: produtividade de colmos (TCH) e produtividade de açúcar (TPH) em que a maior diferença foi observada para a cultivar SP80-3280. As cultivares apresentaram respostas diferenciadas na eficiência de utilização da água. No manejo irrigado por gotejamento houve elevação de 24% na produtividade de colmos e de 23% na produtividade de açúcar, em relação ao manejo de sequeiro.This study aimed to evaluate the effect of drip irrigation technology in different sugarcane varieties in two crop cycles (plant cane and ratoon). The experimental design was in completly randomized blocks, in split-plot with four replications, constituted by three sugarcane genotypes: RB867515; RB855536 and SP80-3280 and two crop management: drip irrigation system and rainfed system, totalizing six treatments. The first cycle lasted for 336 days, with rainfall of 1,480 mm. The volume of water provided by the system of drip irrigation was 400 mm, totaling 1,880 mm. The second cycle lasted for 365 days, the volume of water through rainfall was 1,394 mm, added to 320 mm provided by the system of irrigation, totaled 1,714 mm. Interaction between management and cultivars was found significant for the variables: productivity of stalks (TCH) and sugar yield (TPH), in which the largest difference was observed for cultivar SP80-3280. There was significant response to drip irrigation, on average the increase of production of stalks and sugar was 24 and 23%, respectively
Hyperboloidal discontinuous time-symmetric numerical algorithm with higher order jumps for gravitational self-force computations in the time domain
Within the next decade the Laser Interferometer Space Antenna (LISA) is due
to be launched, providing the opportunity to extract physics from stellar
objects and systems, such as \textit{Extreme Mass Ratio Inspirals}, (EMRIs)
otherwise undetectable to ground based interferometers and Pulsar Timing Arrays
(PTA). Unlike previous sources detected by the currently available
observational methods, these sources can \textit{only} be simulated using an
accurate computation of the gravitational self-force. Whereas the field has
seen outstanding progress in the frequency domain, metric reconstruction and
self-force calculations are still an open challenge in the time domain. Such
computations would not only further corroborate frequency domain calculations
and models, but also allow for full self-consistent evolution of the orbit
under the effect of the self-force. Given we have \textit{a priori} information
about the local structure of the discontinuity at the particle, we will show
how to construct discontinuous spatial and temporal discretisations by
operating on discontinuous Lagrange and Hermite interpolation formulae and
hence recover higher order accuracy. In this work we demonstrate how this
technique in conjunction with well-suited gauge choice (hyperboloidal slicing)
and numerical (discontinuous collocation with time symmetric) methods can
provide a relatively simple method of lines numerical algorithm to the problem.
This is the first of a series of papers studying the behaviour of a
point-particle prescribing circular geodesic motion in Schwarzschild in the
\textit{time domain}. In this work we describe the numerical machinery
necessary for these computations and show not only our work is capable of
highly accurate flux radiation measurements but it also shows suitability for
evaluation of the necessary field and it's derivatives at the particle limit
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