327 research outputs found
Identification and Functional Analysis of Healing Regulators in Drosophila
© 2015 Álvarez-Fernández et al. Wound healing is an essential homeostatic mechanism that maintains the epithelial barrier integrity after tissue damage. Although we know the overall steps in wound healing, many of the underlying molecular mechanisms remain unclear. Genetically amenable systems, such as wound healing in Drosophila imaginal discs, do not model all aspects of the repair process. However, they do allow the less understood aspects of the healing response to be explored, e.g., which signal(s) are responsible for initiating tissue remodeling? How is sealing of the epithelia achieved? Or, what inhibitory cues cancel the healing machinery upon completion? Answering these and other questions first requires the identification and functional analysis of wound specific genes. A variety of different microarray analyses of murine and humans have identified characteristic profiles of gene expression at the wound site, however, very few functional studies in healing regulation have been carried out. We developed an experimentally controlled method that is healing-permissive and that allows live imaging and biochemical analysis of cultured imaginal discs. We performed comparative genome-wide profiling between Drosophila imaginal cells actively involved in healing versus their non-engaged siblings. Sets of potential wound-specific genes were subsequently identified. Importantly, besides identifying and categorizing new genes, we functionally tested many of their gene products by genetic interference and overexpression in healing assays. This non-saturated analysis defines a relevant set of genes whose changes in expression level are functionally significant for proper tissue repair. Amongst these we identified the TCP1 chaperonin complex as a key regulator of the actin cytoskeleton essential for the wound healing response. There is promise that our newly identified wound-healing genes will guide future work in the more complex mammalian wound healing response.CAF and FP were supported by the EU FP6 STREP project WOUND and ST held a Spanish FPU PhD studentship. Research in the EMB laboratory is funded by grants of the EU (FP6 STREP project WOUND), the Spanish Ministry of Economy and Competitivity (DGI and CONSOLIDER grants) and the Generalitat de Catalunya (SGR)Peer Reviewe
Robotic Motion using Harmonic Functions and Finite Elements
The harmonic functions have proved to be a powerful technique for motion planning in a known environment. They have two important properties: given an initial point and an objective in a connected domain, a unique path exists between those points. This path is the maximum gradient path of the harmonic function that begins in the initial point and ends in the goal point. The second property is that the harmonic function cannot have local minima in the interior of the domain (the objective point is considered as a border). This paper proposes a new method to solve Laplace's equation. The harmonic function solution with mixed boundary conditions provides paths that verify the smoothness and safety considerations required for mobile robot path planning. The proposed approach uses the Finite Elements Method to solve Laplace's equation, and this allows us to deal with complicated shapes of obstacles and walls. Mixed boundary conditions are applied to the harmonic function to improve the quality of the trajectories. In this way, the trajectories are smooth, avoiding the corners of walls and obstacles, and the potential slope is not too small, avoiding the difficulty of the numerical calculus of the trajectory. Results show that this method is able to deal with moving obstacles, and even for non-holonomic vehicles. The proposed method can be generalized to 3D or more dimensions and it can be used to move robot manipulators
High-accuracy global localization filter for three-dimensional environments
The localization problem in mobile robotics can be defined as the search of the robot's coordinates in a known environment. If there is no information about the initial location, we are talking about global localization. In this work, we have developed an algorithm that solves this problem in a three-dimensional (3D) environment using evolutionary computation concepts. The method has been called RELF-3D and has many features that make it very robust and reliable: thresholding and discarding mechanisms, different cost functions, effective convergence criteria, and so on. The resulting global localization module has been tested in numerous experiments and the most important improvement obtained is the accuracy of the method, allowing its application in manipulation tasksThe localization problem in mobile robotics can be defined as the search of the robot's coordinates in a known environment. If there is no information about the initial location, we are talking about global localization. In this work, we have developed an algorithm that solves this problem in a three-dimensional (3D) environment using evolutionary computation concepts. The method has been called RELF-3D and has many features that make it very robust and reliable: thresholding and discarding mechanisms, different cost functions, effective convergence criteria, and so on. The resulting global localization module has been tested in numerous experiments and the most important improvement obtained is the accuracy of the method, allowing its application in manipulation tasksThis work has been supported by the CAM Project S2009/DPI-1559/ROBOCITY2030 II,
developed by the research team RoboticsLab at the University Carlos III of Madrid.Publicad
SMA based elbow exoskeleton for rehabilitation therapy and patient evaluation
A large number of musculoskeletal and neurological disorders can affect the upper limb limiting the subject's ability to perform activities of daily living. In recent years, rehabilitation therapies based on robotics have been proposed as complement to the work of therapists. This paper introduces a prototype of exoskeleton for the evaluation and rehabilitation therapy of the elbow joint in flexion extension and pronation-supination. The main novelty is the use of bioinspired actuators based on shape memory alloys (for the first time) in an upper limb rehabilitation exoskeleton. Because of this, the device presents a light weight, less than 1 kg, and noiseless operation, both characteristics are very beneficial for rehabilitation therapies. In addition, the prototype has been designed with low-cost electronics and materials, and the result is a wearable, comfortable, and cheap rehabilitation exoskeleton for the elbow joint. The exoskeleton can generate the joint torque (active mode) or it can be used as a passive tool. (The patient performs therapy by itself, carrying the device while it collects relevant movement data for evaluation.) The simulations and experimental tests validate the solution in the first phases of rehabilitation therapies when slow and repetitive movements are required.This work was supported in part by the Exoesqueleto para Diagnostico y Asistencia en Tareas de Manipulacion through the Spanish Research Project under Grant DPI2016-75346-R, and in part by the RoboCity2030-DIH-CM Madrid Robotics Digital Innovation Hub ("Robotica aplicada a la mejora de la calidad de vida de los ciudadanos. fase IV''), funded by the "Programas de Actividades I+D en la Comunidad de Madrid,'' and co-funded by the Structural Funds of the EU, under Grant S2018/NMT-4331
Flexible shape memory alloy actuators for soft robotics: Modelling and control
One of the limitations in the development of really soft robotic devices is the development of soft actuators. In recent years, our research group has developed a new flexible shape memory alloy actuator that provides more freedom of movements and a better integration in wearable robots, especially in soft wearable robots. Shape memory alloy wires present characteristics such as force/weight ratio, low weight, and noiseless actuation, which make them an ideal choice in these types of applications. However, the control strategy must take into account its complex dynamics due to thermal phase transformation. Different control approaches based on complex non-linear models and other model-free control methods have been tested on real systems. Some exoskeleton prototypes have been developed, which demonstrate the utility of this actuator and the advantages offered by these flexible actuators to improve the comfort and adaptability of exoskeletons
Kullback-Leibler divergence-based differential eEvolution Markov chain filter for global localization of mobile robots
One of the most important skills desired for a mobile robot is the ability to obtain its own location even in challenging environments. The information provided by the sensing system is used here to solve the global localization problem. In our previous work, we designed different algorithms founded on evolutionary strategies in order to solve the aforementioned task. The latest developments are presented in this paper. The engine of the localization module is a combination of the Markov chain Monte Carlo sampling technique and the Differential Evolution method, which results in a particle filter based on the minimization of a fitness function. The robot's pose is estimated from a set of possible locations weighted by a cost value. The measurements of the perceptive sensors are used together with the predicted ones in a known map to define a cost function to optimize. Although most localization methods rely on quadratic fitness functions, the sensed information is processed asymmetrically in this filter. The Kullback-Leibler divergence is the basis of a cost function that makes it possible to deal with different types of occlusions. The algorithm performance has been checked in a real map. The results are excellent in environments with dynamic and unmodeled obstacles, a fact that causes occlusions in the sensing area.The research leading to these results has received funding from the RoboCity2030-III-CM project (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, fase III; S2013/MIT-2748),funded by Programas de Actividades I+Den la Comunidad de Madrid and cofunded by the Structural Funds of the EU
AFM and Microrheology in the Zebrafish Embryo Yolk Cell
Elucidating the factors that direct the spatio-temporal organization of evolving tissues is one of the primary purposes in the study of development. Various propositions claim to have been important contributions to the understanding of the mechanical properties of cells and tissues in their spatiotemporal organization in different developmental and morphogenetic processes. However, due to the lack of reliable and accessible tools to measure material properties and tensional parameters in vivo, validating these hypotheses has been difficult. Here we present methods employing atomic force microscopy (AFM) and particle tracking with the aim of quantifying the mechanical properties of the intact zebrafish embryo yolk cell during epiboly. Epiboly is an early conserved developmental process whose study is facilitated by the transparency of the embryo. These methods are simple to implement, reliable, and widely applicable since they overcome intrusive interventions that could affect tissue mechanics. A simple strategy was applied for the mounting of specimens, AFM recording, and nanoparticle injections and tracking. This approach makes these methods easily adaptable to other developmental times or organisms
Assessment of learning outcomes in computing studies
The assessment of learning outcomes is a key concept in the European Credit Transfer and Accumulation System (ECTS) since credits are awarded when the assessment shows the competences which were aimed at have been developed at an appropriate level. This paper describes a study which was first part of the project of the Bologna Experts Team-Spain and then developed as an independent study. It was carried out with the overall goal to gain experience in the assessment of learning outcomes. More specifically it aimed at 1) designing procedures for the assessment of learning outcomes related to these compulsory generic competences; 2) testing some basic psychometric features that an assessment device with some consequences for the subjects being evaluated needs to prove; 3) testing different procedures of standard setting, and 4) using assessment results as orienting feedback to students and their tutors. The process of development of tests to carry out the assessment of learning outcomes related to these competences, as well as some basic features regarding their reliability and validity is described and first results on the comparison of results achieved at two academic levels, will also be described at a later stage
An unfrequent cause for mino salivary gland tumour: Adenomatoid hyperplasia
[ES] Las glándulas salivales pueden sufrir numerosas enfermedades neoplásicas y no neoplásicas. Aquéllas que simulan tumores son especialmente importantes ya que su tratamiento, pronóstico y seguimiento clínico son diferentes. La hiperplasia adenomatosa de glándula salival menor se encuentra entre ellas. Se trata de una entidad muy poco frecuente, con muy pocas descripciones documentadas en la literatura médica, cuya etiología es desconocida. Debido a su curso clínico indolente, a menudo es objetivada casualmente durante un tratamiento dental, una exploración de cavidad oral realizada por otro motivo o autoobjetivada por el paciente. Su diagnóstico no siempre es fácil ya que pueden encontrarse diferentes patrones histológicos con diferente consideración. La extirpación quirúrgica completa, es recomendable para su diagnóstico y es curativa. Debe realizarse seguimiento para detectar posibles recidivas o degeneraciones malignas. Presentamos un caso de hiperplasia adenomatosa de glándula salival menor de paladar blando, una localización poco frecuente.
[EN] Salivary glands may be affected by numerous neoplastic and non-neoplastic conditions. Tumour-like conditions should be clearly distinguished one from another and from true neoplasms since their treatment, prognosis and follow-up may differ.
Adenomatoid hyperplasia of minor salivary gland is a rare entity, with very few documented reports in the literature since its first description, whose etiology remains unclear. Due to its asymptomatic behaviour, it is commonly encountered during a dental treatment, an oral exploration or accidentally by the patient himself . Its clinical diagnosis is not always an easy task . It may resemble other conditions such as salivary gland adenoma or adenocarcinoma, and different histological features may be observed one case from another. Total surgical excision should be performed for diagnosis and is considered curative. Follow-up may be recommended to exclude future recurrencies or malignant degeneration, being these facts quite uncommon. A case of adenomatoid hyperplasia of minor salivary gland in soft palate, a rare site for this condition, is reported
Tonsillar Polypoid Lymphangioma
[ES] Los tumores vasculares benignos, especialmente aquellos que se originan a partir de
los vasos linfáticos, son muy infrecuentes en la amígdala palatina y, por ello,
raramente se recogen en la literatura médica. Su aspecto es similar al de otras
entidades polipoideas de las amígdalas entre las cuáles se incluyen el fibroma, el
lipoma, el papiloma, quistes y otros, aunque su comportamiento clínico puede ser
muy diferente. Su patogénesis aún no está esclarecida . Su curso clínico suele ser
asintomático en el momento de diagnóstico aunque puede puede producirse un
crecimiento brusco que comprometa la vía aerodigestiva y por ello debe realizarse
exéresis completa del mismo. Presentamos un caso de linfangioma pediculado de
amígdala y se revisa la literatura disponible.
[EN] Benign vascular tumours , specially those arising from lymphatic vessels, occur so
unfrequently on the tonsil that are scarcelly reported. Their appearance may be
similar to other polypoid lesions of the tonsils which include fibroma, lipoma,
papilloma, cysts and others but their clinical behaviour may be very different. Their
pathogenesis is not clearly determined yet. An asympthomatic clinical pattern is the
most frequently reported behaviour at diagnosis but sudden growth, with airway or
deglutory pathway compromise, may occur and so, complete surgical treatment
should be performed. A case of sympthomatic pedunculated tonsillar linphangiona is
reported and a medical literature review is provided
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