550 research outputs found

    Data Fusion for Vision-Based Robotic Platform Navigation

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    Data fusion has become an active research topic in recent years. Growing computational performance has allowed the use of redundant sensors to measure a single phenomenon. While Bayesian fusion approaches are common in general applications, the computer vision community has largely relegated this approach. Most object following algorithms have gone towards pure machine learning fusion techniques that tend to lack flexibility. Consequently, a more general data fusion scheme is needed. The motivation for this work is to propose methods that allow for the development of simple and cost effective, yet robust visual following robots capable of tracking a general object with limited restrictions on target characteristics. With that purpose in mind, in this work, a hierarchical adaptive Bayesian fusion approach is proposed, which outperforms individual trackers by using redundant measurements. The adaptive framework is achieved by relying in each measurement\u27s local statistics and a global softened majority voting. Several approaches for robots that can follow targets have been proposed in recent years. However, many require the use of several, expensive sensors and often the majority of the image processing and other calculations are performed independently. In the proposed approach, objects are detected by several state-of-the-art vision-based tracking algorithms, which are then used within a Bayesian framework to filter and fuse the measurements and generate the robot control commands. Target scale variations and, in one of the platforms, a time-of-flight (ToF) depth camera, are used to determine the relative distance between the target and the robotic platforms. The algorithms are executed in real-time (approximately 30fps). The proposed approaches were validated in a simulated application and several robotics platforms: one stationary pan-tilt system, one small unmanned air vehicle, and one ground robot with a Jetson TK1 embedded computer. Experiments were conducted with different target objects in order to validate the system in scenarios including occlusions and various illumination conditions as well as to show how the data fusion improves the overall robustness of the system

    Golabi-Ito-Hall syndrome results from a missense mutation in the WW domain of the PQBP1 gene

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    Background: Golabi, Ito, and Hall reported a family with X linked mental retardation (XLMR), microcephaly, postnatal growth deficiency, and other anomalies, including atrial septal defect, in 1984.Methods: This family was restudied as part of our ongoing study of XLMR, but significant linkage to X chromosome markers could not be found. Extreme short stature and microcephaly as well as other new clinical findings were observed. Mutations in the polyglutamine tract binding protein 1 gene (PQBP1) have recently been reported in four XLMR disorders (Renpenning, Hamel cerebro-palato-cardiac, Sutherland-Haan, and Porteous syndromes) as well as in several other families. The clinical similarity of our family to these patients with mutations in PQBP1, particularly the presence of microcephaly, short stature, and atrial septal defect, prompted examination of this gene.Results: A missense mutation in PQBP1 was identified which changed the conserved tyrosine residue in the WW domain at position 65 to a cysteine (p.Y65C).Conclusions: This is the first missense mutation identified in PQBP1 and the first mutation in the WW domain of the gene. The WW domain has been shown to play an important role in the regulation of transcription by interacting with the PPxY motif found in transcription factors. The p.Y65C mutation may affect the proper functioning of the PQBP1 protein as a transcriptional co-activator

    Total recovery from monoclonal gammopathy and autoimmune phenomena after parathyroidectomy

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    Based on the observation of a patient with a causal relationship between hyperparathyroidism and development of both autoimmune disease and paraproteinemia, we hypothesize a novel cause of autoimmunity triggered in the context of hyperparathyroidism. © Cañas et al.; Licensee Bentham Open

    Efectos garrapaticidas de algunos aceites esenciales

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    Soluciones acuo-etanólicas de aceites esenciales de Lippia (3 quimiotipos), Schinus molle, Tagetes, Lavandina (dos quimiotipos), Hisopo, Romero y Ciprés, fueron sometidas a ensayos in Vitro para evaluar sus efectos sobre le supervivencia y reproducción de las garrapata Rhipicephalus (Boophilus) microplus. Los aceites de Lippia, Tagetes e Hisopo mostraron buenos niveles de inhibición de la oviposición y de mortalidad superiores al 50%, a una concentración del 1%; no obstante, a concentraciones menores (0.5 y 0.1%) los resultados fueron inferiores. Especialmente activos fueron los aceites de varios quimiotipos de Lippia, que sorpresivamente mantuvieron niveles similares de actividad, lo cual indica un efecto sinergista o la presencia de una sustancia muy activa a concentraciones muy pequeñasPublishe

    Reúso de aguas residuales: impacto en los atributos químicos y macronutricionales en un suelo inceptisol irrigado con aguas residuales domésticas tratadas

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    (Eng) This study aimed to estimate the potential impact of wastewater reuse on the chemical and macronutritional attributes of an inceptisol cropped with sugarcane. The experimental design was in three randomized blocks, in split-plot design (three replicates per treatment), with three different irrigation treatments: treated wastewater (TWW) from Cañaveralejo wastewater treatment plant (WWTP-C); groundwater without any fertilizer (GW); and groundwater with chemical fertilizer (GW+CF). At the end of the study, plots with treated wastewater irrigation improved slightly Ca/Mg, Mg/K, and Ca+Mg/K ratios, increased OM, Na, P, and K contents and decreased pronouncedly inorganic nitrogen (N-NH4, N-NO3) of an inceptisol. Besides, we found that the type of treatment did not influence the variation of chemical attributes in soil, since statistically differences were no found in comparison among treatments. Therefore, our results suggest no adverse impact on chemical soil attributes due to wastewater reuse on sugarcane irrigation.(Spa) Este estudio tuvo como objetivo estimar el potencial impacto en los atributos químicos y macronutricionales de un suelo inceptisol sembrado con caña de azúcar y sometido a tres diferentes tratamientos de riego: Efluente de la PTAR-C (T1), Agua de Pozo (T2) y Agua de Pozo más fertilización química (T3). Se instaló un experimento en bloques completos al alzar con parcelas divididas con tres repeticiones. Al final del estudio se encontró que las relaciones de bases químicas (Ca/Mg, Mg/K, Ca+Mg/K) mejoraron en todas las parcelas, en todos los tratamientos, situación que se ratifica al no encontrarse diferencias estadísticas significativas entre los tratamientos. Así mismo, se encontró que el tipo de tratamiento no influyó en la variación en los contenidos de los macronutrientes (N, P, K) del suelo. Los contenidos de materia orgánica, P, Na y K aumentaron; y disminuyeron los de nitrógeno inorgánico (N-NH4, N-NO3) independientemente del tratamiento, lo que permite inferir la no asociación de impactos adversos en el suelo por el reúso de agua residual tratada en riego de caña de azúcar

    Bone remodeling: A tissue-level process emerging from cell-level molecular algorithms

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    <div><p>The human skeleton undergoes constant remodeling throughout the lifetime. Processes occurring on microscopic and molecular scales degrade bone and replace it with new, fully functional tissue. Multiple bone remodeling events occur simultaneously, continuously and independently throughout the body, so that the entire skeleton is completely renewed about every ten years.Bone remodeling is performed by groups of cells called Bone Multicellular Units (BMU). BMUs consist of different cell types, some specialized in the resorption of old bone, others encharged with producing new bone to replace the former. These processes are tightly regulated so that the amount of new bone produced is in perfect equilibrium with that of old bone removed, thus maintaining bone microscopic structure.To date, many regulatory molecules involved in bone remodeling have been identified, but the precise mechanism of BMU operation remains to be fully elucidated. Given the complexity of the signaling pathways already known, one may question whether such complexity is an inherent requirement of the process or whether some subset of the multiple constituents could fulfill the essential role, leaving functional redundancy to serve an alternative safety role. We propose in this work a minimal model of BMU function that involves a limited number of signals able to account for fully functional BMU operation. Our main assumptions were i) at any given time, any cell within a BMU can select only one among a limited choice of decisions, i.e. divide, die, migrate or differentiate, ii) this decision is irreversibly determined by depletion of an appropriate internal inhibitor and iii) the dynamics of any such inhibitor are coupled to that of specific external mediators, such as hormones, cytokines, growth factors. It was thus shown that efficient BMU operation manifests as an emergent process, which results from the individual and collective decisions taken by cells within the BMU unit in the absence of any external planning.</p></div
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