287 research outputs found
MsWH: A multi-sensory hardware platform for capturing and analyzing physiological emotional signals
This paper presents a new physiological signal acquisition multi-sensory platform for emotion detection: Multi-sensor Wearable Headband (MsWH). The system is capable of recording and analyzing five different physiological signals: skin temperature, blood oxygen saturation, heart rate (and its variation), movement/position of the user (more specifically of his/her head) and electrodermal activity/bioimpedance. The measurement system is complemented by a porthole camera positioned in such a way that the viewing area remains constant. Thus, the user''s face will remain centered regardless of its position and movement, increasing the accuracy of facial expression recognition algorithms. This work specifies the technical characteristics of the developed device, paying special attention to both the hardware used (sensors, conditioning, microprocessors, connections) and the software, which is optimized for accurate and massive data acquisition. Although the information can be partially processed inside the device itself, the system is capable of sending information via Wi-Fi, with a very high data transfer rate, in case external processing is required. The most important features of the developed platform have been compared with those of a proven wearable device, namely the Empatica E4 wristband, in those measurements in which this is possible
Neutral perfect fluids of Majumdar-type in general relativity
We consider the extension of the Majumdar-type class of static solutions for
the Einstein-Maxwell equations, proposed by Ida to include charged perfect
fluid sources. We impose the equation of state and discuss
spherically symmetric solutions for the linear potential equation satisfied by
the metric. In this particular case the fluid charge density vanishes and we
locate the arising neutral perfect fluid in the intermediate region defined by
two thin shells with respective charges and . With its innermost flat
and external (Schwarzschild) asymptotically flat spacetime regions, the
resultant condenser-like geometries resemble solutions discussed by Cohen and
Cohen in a different context. We explore this relationship and point out an
exotic gravitational property of our neutral perfect fluid. We mention possible
continuations of this study to embrace non-spherically symmetric situations and
higher dimensional spacetimes.Comment: 9 page
Contrast Enhancement of Optical Coherence Tomography Images Using Branched Gold Nanoparticles
We propose the use of branched gold nanoparticles (B-GNPs) as a contrast agent for optical coherence tomography (OCT) imaging. Our results show that even when the central source of our OCT (1325 nm) is too far from the maximum peak of the plasmon resonance, branched nanoparticles scatter light very efficiently at this wavelength. B-GNPs were tested as a contrast agent in water and agarose-TiO2 tissue phantoms; the estimated increments in contrast were 9.19 dB and 15.07 dB for branched nanoparticles in water with concentrations of 2.2×109 NPs/mL and 6.6×109 NPs/mL, respectively, while for agarose-TiO2 tissue phantoms the estimated value was 3.17 dB. These results show the promising application of B-GNPs as a contrast agent for tissue imaging using OCT, not only for sources at 1325 nm but also at other central wavelengths located between 800 and 1000 nm
Human bony labyrinth is an indicator of population history and dispersal from Africa.
The dispersal of modern humans from Africa is now well documented with genetic data that track population history, as well as gene flow between populations. Phenetic skeletal data, such as cranial and pelvic morphologies, also exhibit a dispersal-from-Africa signal, which, however, tends to be blurred by the effects of local adaptation and in vivo phenotypic plasticity, and that is often deteriorated by postmortem damage to skeletal remains. These complexities raise the question of which skeletal structures most effectively track neutral population history. The cavity system of the inner ear (the so-called bony labyrinth) is a good candidate structure for such analyses. It is already fully formed by birth, which minimizes postnatal phenotypic plasticity, and it is generally well preserved in archaeological samples. Here we use morphometric data of the bony labyrinth to show that it is a surprisingly good marker of the global dispersal of modern humans from Africa. Labyrinthine morphology tracks genetic distances and geography in accordance with an isolation-by-distance model with dispersal from Africa. Our data further indicate that the neutral-like pattern of variation is compatible with stabilizing selection on labyrinth morphology. Given the increasingly important role of the petrous bone for ancient DNA recovery from archaeological specimens, we encourage researchers to acquire 3D morphological data of the inner ear structures before any invasive sampling. Such data will constitute an important archive of phenotypic variation in present and past populations, and will permit individual-based genotype-phenotype comparisons
Three-dimensional geometric morphometrics for studying floral shape variation
Variation in floral shape is of major interest to evolutionary and pollination biologists, plant systematists and developmental geneticists. Quantifying this variation has been difficult due to the three-dimensional (3D) complexity of angiosperm flowers. By combining 3D geometric representations of flowers obtained by micro-computed tomography scanning with geometric morphometric methods, well established in zoology and anthropology, floral shape variation can be analyzed quantitatively, allowing for powerful interpretation and visualization of the resulting patterns of variation
Development of a bovine X chromosome linkage group and painting probes to assess cattle, sheep, and goat X chromosome segment homologies
The X chromosome linkage group is conserved in placental mammals. However, X chromosome morphological differences, due to internal chromosome rearrangements, exist among mammalian species. We have developed bovine chromosome painting probes for Xp and Xq to assess segment homologies between the submetacentric bovine X chromosome and the acrocentric sheep and goat X chromosomes. These painting probes and their corresponding DNA libraries were developed by chromosome micromanipulation, DNA micropurification, microcloning, and PCR amplification. The bovine Xp painting probe identified an interstitially located homologous segment in the sheep and goat Xq region, most probably resulting from chromosome inversion. Ten type II (microsatellite) markers obtained from the bovine Xq library and five other X chromosome assigned, but unlinked, markers were used to generate a linkage map for Xq spanning 89.4 centimorgans. The chromosome painting probes and molecular markers generated in this study would be useful for comparative mapping and tracing of internal X chromosome rearrangements in all ruminant species and would contribute to the understanding of mammalian sex chromosome evolution
Modelos de Crecimiento de Frutos de Limonero 'Eureka' de la Provincia de Corrientes, Argentina
El objetivo de este trabajo fue modelar el crecimiento de limonero ‘Eureka’ (Citrus limón (L.) Burn f) injertado sobre Limón Rugoso (Citrus jambhiri Lush), desde los 60 días después de plena floración hasta la cosecha, en plantaciones comerciales, de la provincia de Corrientes, Argentina. Para ello se registró el diámetro ecuatorial de frutos desde los 60 días después de plena floración hasta el momento de cosecha en cuatro ambientes de la provincia de Corrientes, Argentina. Para describir el crecimiento se compararon los modelos no lineales de tipo sigmoideo: logístico, Gompertz y monomolecular. Se utilizaron como criterios de selección de los modelos: AIC, BIC y el CME (cuadrado medio del error). La precisión del modelo seleccionado se obtuvo mediante validación cruzada. Los modelos seleccionados para describir el crecimiento de frutos de limonero ‘Eureka’ fueron los modelos monomolecular y logístico, los cuales tuvieron un error de estimación que fue medido en términos del CME con valores menores a 20,03. Los parámetros estimados para los modelos seleccionados resultaron significativos (p < 0,01). De esta manera, productores, y empresas exportadoras citrícolas de la región podrán contar con una herramienta con la que puedan predecir la producción al momento de cosecha y así para prever estrategias de comercialización
Self-similar and charged spheres in the diffusion approximation
We study spherical, charged and self--similar distributions of matter in the
diffusion approximation. We propose a simple, dynamic but physically meaningful
solution. For such a solution we obtain a model in which the distribution
becomes static and changes to dust. The collapse is halted with damped mass
oscillations about the absolute value of the total charge.Comment: 15 pages, 7 figure
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