265 research outputs found

    Vision-Guided Mobile Robot Navigation

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    This report discusses the use of vision feedback for autonomous navigation by a mobile robot in indoor environments. In particular, we have discussed in detail the issues of camera calibration and how binocular and monocular vision may be utilized for self-location by the robot. A noteworthy feature of monocular vision is that the camera image is compared with a CAD model of the interior of the hallways using the PSEIKI reasoning system; this reasoning system allows the comparison to take place at different levels of geometric detail

    Produção de grãos em relação com reação a doenças em feijoeiro comum cultivado em sistema de manejo orgânico.

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    Este trabalho objetivou avaliar a produção de grãos do feijoeiro-comum em sistema de manejo orgânico e os efeitos do crestamento bacteriano comum e da mancha angular sobre a produção do feijoeiro-comum da cultivar BRS supremo sob diferentes tipos de cultura de cobertura e manejo do solo.CONAFE

    Choroidal thickness measured using swept-source optical coherence tomography is reduced in patients with type 2 diabetes

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    Objective To compare choroidal thickness between patients with type 2 diabetes (T2D) and healthy controls measured using swept-source optical coherence tomography (SS-OCT). Methods The sample comprised 157 eyes of 94 T2D patients, 48 eyes of which had diabetic macular edema (DME), and 71 normal eyes of 38 healthy patients. Subfoveal (SF) choroidal thickness, and choroidal thickness at 500-µm intervals up to 2500 µm nasal and temporal from the fovea were measured using the SS-OCT. Choroidal thicknesses were compared between groups using Student’s t-test. Additionally, Pearson correlations were calculated between diabetes duration, glycosylated hemoglobin (HbA1c) levels, and choroidal thickness. Results Mean diabetes duration was 16.6±9.5 years, while mean glycosylated hemoglobin was 7.7 ±1.3%. Overall, the choroid was significantly thinner in T2D patients. Individuals with DME had reduced choroidal thickness in all measurements, except at 2000 and 2500-µm nasal positions, compared to healthy controls. There was a moderate correlation between choroidal thickness and HbA1c levels in DME patients (SF: r = 0.342; p = 0.017). Diabetes duration did not correlate significantly with choroidal thickness. Conclusion SS-OCT measurements revealed that the choroid was significantly thinner in T2D patients, moderate non-proliferative diabetic retinopathy patients, and DME patients than in healthy individuals. Further studies are needed to clarify the effect of diabetes on this layer and the relationship between choroidal thickness and DME

    Manipulation of extinction features in frequency combs through the usage of graphene

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    Lately, the integration of two-dimensional materials into semiconductor devices has allowed the modification of their effective index by simply applying a modest voltage (between 0 and 3 volts). In this work, we present a device composed of two evanescently coupled silicon microring resonators where both rings have a graphene layer on top. This design is aimed to produce frequency combs with transmission characteristics controlled upon voltage application to the graphene layer. We numerically analyze the device response as a function of the incident wavelength and applied voltage. The results showed a low input intensity (0.6 GW/cm2) needed and a rapid response time (0.1 μs), in comparison to devices controlled by heat injection

    Assessment of the retinal nerve fiber layer in individuals with obstructive sleep apnea

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    Background: The effect of obstructive sleep apnea (OSA) syndrome in the peripapillary retinal nerve fiber layer (RNFL) thicknesses remains unclear. The purpose of this study was to assess RNFL measurements acquired using scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in patients with OSA. Methods: The sample of this cross-sectional study included 40 OSA patients and 45 age-matched controls, consecutively and prospectively selected. All participants underwent at least one reliable standard automated perimetry (SAP) test, while RNFL measurements were obtained using the SLP and OCT. The OSA group was divided into 3 sub-groups based on the apnea/hypopnea index (AHI): mild, moderate, or severe OSA. SAP, SLP, and OCT outcomes were compared between the control and OSA groups. The relationship between AHI and RNFL parameters was also evaluated. Results: Age was not different between both groups. Mean deviation of SAP was -0.47 ± 0.9 dB and -1.43 ± 2.3 dB in the control and OSA groups, respectively (p = 0.01). RNFL thickness measured with OCT was similar between groups. OSA patients showed increased nerve fiber indicator (NFI; 20.9 ± 7.9 versus 16.42 ± 7.82; p = 0.01) and decreased superior average (59.74 ± 10.35 versus 63.73 ± 6.58; p = 0.03) obtained with SLP compared with healthy individuals. In the total sample, NFI and AHI were moderately correlated (r = 0.358; p = 0.001). In severe OSA subjects (n = 22), NFI and AHI had a Spearman correlation coefficient of 0.44 (p = 0.04). Conclusion: RNFL thickness measured with OCT did not differ significantly between groups. Severe OSA was related to a reduction of the RNFL thickness assessed by SLP

    La hibridación entre el género policiaco y la comedia en la ficción televisiva norteamericana. Estudio de caso de ‘Castle’

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    El presente artículo tiene como objetivo aproximarse a las actuales fórmulas de hibridación de géneros como premisa básica para la innovación en la ficción norteamericana televisiva. En particular, se centra en el reciente y exitoso experimento, que comenzó hace algo más de una década, de hibridar drama policiaco con comedia y humor. Además, se pretende mostrar cómo gracias a la creación de un nuevo personaje principal dotado de un trasfondo personal y multidimensional se abandonan la seriedad y rigidez características del género dando paso a la diversión y el entretenimiento, más propios de las comedias de situación que del género policiaco. Con esta finalidad, se va a analizar en profundidad, como estudio de caso, la figura del protagonista de una serie de la cadena ABC —concretamente a Richard Castle— así como su modo de actuar, pensar y hablar, con el objetivo de observar su naturaleza cómica en un contexto totalmente dramático caracterizado por la muerte y el crimen. This article aims to approach current ways for genre hybridization as basic premise for innovation in American TV series. Especially, it focuses on the recent successful experiment, which began just over a decade, consisting in hybridizing police drama with comedy and humor. Also, it aims to show how, through the creation of a new main character with a personal and multidimensional background, the seriousness and stiffness characteristics of the genre are abandoned, giving way to fun and entertainment, more typical of sitcoms than the detective genre. So, the main character - specifically Richard Castle, from ABC series-is going to be analyzed in depth as well as his way of acting, thinking and speaking with the aim of exposing his comic nature in a totally dramatic context such as death and crime

    Foliar treatments as a strategy to control iron chlorosis in orange trees

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    Different foliar treatments were applied to evaluate the recovery of iron chlorosis of orange trees (Citrus sinensis (L.) Osb. cv. 'Valencia late') grown on a calcareous soil. The treatments were: Fe (II) sulphate (500 mg Fe L-1), sulphuric acid (0.5 mM H2SO4), Fe (III)-chelate (Hampiron 654 GS, 120 mg Fe L-1) and distilled water as a control. The recovery from iron chlorosis was evaluated with the SPAD-502 apparatus and the values converted to total chlorophyll concentration. The effects of treatments on the mineral composition of leaves and flowers, and the size and quality of fruits were evaluated. The residual effect of treatments was also evaluated one year later. In orange trees, the use of frequent foliar sprays with Fe was able to alleviate Fe chlorosis and prevented yield and quality losses caused by Fe chlorosis. Compared with the control, sprays of Fe (II) sulphate led to higher concentrations of chlorophyll, Fe and Zn in leaves and flowers at the end of the experimental period, and significantly improved fruit size and quality. Leaf Fe concentration increased after the sulphuric acid spray, but this treatment did not affect fruit quality parameters. The mineral composition of flowers and leaves was correlated with some fruit quality parameters obtained one year later. These results suggest that foliar sprays with Fe could help to avoid fruit quality losses caused by Fe chlorosis in citrus orchards

    The impact of COVID-19 on radiological findings in patients accessing the emergency department: a multicentric study

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    The aim of this multicentric study is to illustrate how the COVID-19 pandemic lockdown affected the workload and outcomes of radiological examinations in emergency radiology
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