Hybrid Controller based on Null Space and Consensus Algorithms for Mobile Robot Formation

This work presents a novel hybrid control approach based on null space and consensus algorithms to solve the scalability problems of mobile robot formation and improve leader control through multiple control objectives. In previous works, the training of robots based on the null space requires a rigid training structure based on a geometric shape, which increases the number of agents in the formation. The scheme of the control algorithm, which does not make formation scalability possible, must be changed; therefore, seeking the scalability of training based on null space is a challenge that could be solved with the inclusion of consensus algorithms, which allow the control structure to be maintained despite increasing or decreasing the number of robot followers. Another advantage of this proposal is that the formation of the followers does not depend on any geometric figure compared to previous works based on the null space; this new proposal does not present singularities as if the structure is based on geometric shape, the latter one is crucial since the formation of agents can take forms that cannot be achieved with a geometric structure, such as collinear locations, that can occur in many environments. The proposed hybrid control approach presents three tasks: i) leader position task, ii) leader shape task, and iii) follower formation task. The proposed algorithm is validated through simulations, performing tests that use the kinematic model of non-holonomic mobile robots. In addition, linear algebra and Lyapunov theory are used to analyze the stability of the method. Doi: 10.28991/ESJ-2022-06-03-01 Full Text: PD

The Epigenetic Origin of Aneuploidy

Theodore Boveri, eminent German pathologist, observed aneuploidy in cancer cells more than a century ago and suggested that cancer cells derived from a single progenitor cell that acquires the potential for uncontrolled continuous proliferation. Currently, it is well known that aneuploidy is observed in virtually all cancers. Gain and loss of chromosomal material in neoplastic cells is considered to be a process of diversification that leads to survival of the fittest clones. According to Darwin’s theory of evolution, the environment determines the grounds upon which selection takes place and the genetic characteristics necessary for better adaptation. This concept can be applied to the carcinogenesis process, connecting the ability of cancer cells to adapt to different environments and to resist chemotherapy, genomic instability being the driving force of tumor development and progression. What causes this genome instability? Mutations have been recognized for a long time as the major source of genome instability in cancer cells. Nevertheless, an alternative hypothesis suggests that aneuploidy is a primary cause of genome instability rather than solely a simple consequence of the malignant transformation process. Whether genome instability results from mutations or from aneuploidy is not a matter of discussion in this review. It is most likely both phenomena are intimately related; however, we will focus on the mechanisms involved in aneuploidy formation and more specifically on the epigenetic origin of aneuploid cells. Epigenetic inheritance is defined as cellular information—other than the DNA sequence itself—that is heritable during cell division. DNA methylation and histone modifications comprise two of the main epigenetic modifications that are important for many physiological and pathological conditions, including cancer. Aberrant DNA methylation is the most common molecular cancer-cell lesion, even more frequent than gene mutations; tumor suppressor gene silencing by CpG island promoter hypermethylation is perhaps the most frequent epigenetic modification in cancer cells. Epigenetic characteristics of cells may be modified by several factors including environmental exposure, certain nutrient deficiencies, radiation, etc. Some of these alterations have been correlated with the formation of aneuploid cells in vivo. A growing body of evidence suggests that aneuploidy is produced and caused by chromosomal instability. We propose and support in this manuscript that not only genetics but also epigenetics, contribute in a major fashion to aneuploid cell formation

Topografía de la densidad mineral osea: Método de estudio "in vivo" de la cabeza femoral humana mediante TAC

Presentamos un método, no descrito anteriormente, que permite obtener un mapa muy preciso de la distribución topográfica de la densidad mineral ósea relativa de cualquier parte del esqueleto, en el sujeto vivo, a partir de una imagen TAC convencional. El método se basa en la medición directa de los niveles de gris de la imagen TAC, los cuales guardan una relación de linealidad con las Unidades Honsfield, de manera que la densidad óptica de un punto concreto se correlaciona con la densidad ósea del mismo. En nuestro estudio lo hemos aplicado a la cabeza femoral humana, obteniendo la imagen topográfica tridimensional de sus densidades óseas.We describe a new method to obtain an accurate mapping of the bone mineral density which can be applied to any area of the human skeleton in a live subject using conventional CT scan imaging. The method involves direct measurement of grey colour intensity from the CT image. The colour intensity maintains a direct relationship with the Honsfield Units, therefore the optic density of a given area is related to the bone density. In our study this method has been applied to the human femoral head to obtain a three-dimensional topography of the bone density

The Epigenetic Origin of Aneuploidy

Theodore Boveri, eminent German pathologist, observed aneuploidy in cancer cells more than a century ago and suggested that cancer cells derived from a single progenitor cell that acquires the potential for uncontrolled continuous proliferation. Currently, it is well known that aneuploidy is observed in virtually all cancers. Gain and loss of chromosomal material in neoplastic cells is considered to be a process of diversification that leads to survival of the fittest clones. According to Darwin’s theory of evolution, the environment determines the grounds upon which selection takes place and the genetic characteristics necessary for better adaptation. This concept can be applied to the carcinogenesis process, connecting the ability of cancer cells to adapt to different environments and to resist chemotherapy, genomic instability being the driving force of tumor development and progression. What causes this genome instability? Mutations have been recognized for a long time as the major source of genome instability in cancer cells. Nevertheless, an alternative hypothesis suggests that aneuploidy is a primary cause of genome instability rather than solely a simple consequence of the malignant transformation process. Whether genome instability results from mutations or from aneuploidy is not a matter of discussion in this review. It is most likely both phenomena are intimately related; however, we will focus on the mechanisms involved in aneuploidy formation and more specifically on the epigenetic origin of aneuploid cells. Epigenetic inheritance is defined as cellular information—other than the DNA sequence itself—that is heritable during cell division. DNA methylation and histone modifications comprise two of the main epigenetic modifications that are important for many physiological and pathological conditions, including cancer. Aberrant DNA methylation is the most common molecular cancer-cell lesion, even more frequent than gene mutations; tumor suppressor gene silencing by CpG island promoter hypermethylation is perhaps the most frequent epigenetic modification in cancer cells. Epigenetic characteristics of cells may be modified by several factors including environmental exposure, certain nutrient deficiencies, radiation, etc. Some of these alterations have been correlated with the formation of aneuploid cells in vivo. A growing body of evidence suggests that aneuploidy is produced and caused by chromosomal instability. We propose and support in this manuscript that not only genetics but also epigenetics, contribute in a major fashion to aneuploid cell formation

Cirugía abierta frente a cirugía artroscópica en el tratamiento de la inestabilidad anterior de hombro

Se analizan los resultados de una técnica convencional, técnica de Bankart, para el tratamiento de la luxación recidivante anterior de hombro frente a una intervención artroscópica descrita por Rose. Se seleccionan quince pacientes para cada grupo de estudio con un seguimiento postoperatorio medio en torno a los dos años. Los pacientes de cirugía artroscópica se han seleccionado en base a criterios de exclusión preoperatorios e intraoperatorios que requieren la exploración de la estabilidad bajo anestesia y el examen artroscó- pico inicial. En el grupo de cirugía abierta no existe ningún caso de recidiva de la lesión, sólo un paciente no recuperó su nivel de actividad prelesional pero el 73 % de los pacientes presentan restricciones leves de la rotación externa a 90 ° de abducción. En el caso de la cirugía artroscópica un paciente sufrió un nuevo episodio de luxación, dos pacientes no recuperaron su nivel previo de actividad y el 86% presentaban una movilidad completa. Los resultados animan a los autores a continuar desarrollando las técnicas de estabilización artroscópica.We review the results of a conventional technique, Bankart repair, for the treatment of recurrent anterior shoulder instabüity versus an arthroscopic technique developed by Rose. Fifteen patients have been selected for each study group with an average postoperative follow-up around two years. Gandidates for arthroscopic surgery have been selected based on preoperative and intraoperative exclusion criteria. Intraoperative criteria required evaluation of stability under anesthesia and diagnostic arthroscopy. In the open surgery group no redislocations happened. Only one patient did not recover bis previous activity level but 73% had slight restriction to external rotation at 90 ° abduction. In the arthroscopic surgery patients, one of them suffered a redislocation, two cases did not recover their previous activity level but 8 6% kept full shoulder motion. The results encourage the authors to continue the developing trend of arthroscopic stabilization techniques

Evaluation of Hyaluronic Acid Dilutions at Different Concentrations Using a Quartz Crystal Resonator (QCR) for the Potential Diagnosis of Arthritic Diseases

The main objective of this article is to demonstrate through experimental means the capacity of the quartz crystal resonator (QCR) to characterize biological samples of aqueous dilutions of hyaluronic acid according to their viscosity and how this capacity may be useful in the potential diagnosis of arthritic diseases. The synovial fluid is viscous due to the presence of hyaluronic acid, synthesized by synovial lining cells (type B), and secreted into the synovial fluid thus making the fluid viscous. In consequence, aqueous dilutions of hyaluronic acid may be used as samples to emulate the synovial fluid. Due to the viscoelastic and pseudo-plastic behavior of hyaluronic acid, it is necessary to use the Rouse model in order to obtain viscosity values comparable with viscometer measures. A Fungilab viscometer (rheometer) was used to obtain reference measures of the viscosity in each sample in order to compare them with the QCR prototype measures

ODIN AD: a framework supporting the life-cycle of time series anomaly detection applications

Anomaly detection (AD) in numerical temporal data series is a prominent task in many domains, including the analysis of industrial equipment operation, the processing of IoT data streams, and the monitoring of appliance energy consumption. The life-cycle of an AD application with a Machine Learning (ML) approach requires data collection and preparation, algorithm design and selection, training, and evaluation. All these activities contain repetitive tasks which could be supported by tools. This paper describes ODIN AD, a framework assisting the life-cycle of AD applications in the phases of data preparation, prediction performance evaluation, and error diagnosis

Tendencia de las intervenciones para el burnout en enfermeras e internos en psicología: Énfasis del formato multimodal

El estudio tiene como objetivo establecer la tendencia y el formato predominante de intervenciones para el burnout en profesionales de la salud. Se realizó una revisión sistemática (RS) de tipo scoping study en bases de datos PubMed, EBSCO-Host, BioMed Central, Lilacs, Cochrane Register of Trials y Web of Science (período: ene 1983 - febrero 2019). De 7148 estudios identificados se analizaron diez ensayos controlados aleatorios. Las intervenciones psicosociales basada en evidencias se enfocan al formato multimodal de cuatro fases básicas: a) interacción, b) identificación-autocontrol, c) renovación de patrones y, d) retroalimentación. Según sintomatologías del burnout en enfermeras y en internos en psicología, la diferencia media ponderada (DMP) en agotamiento emocional fue -5,82 (IC95%) y en ansiedad estado, DMP: -9,42 (IC95%). En un ensayo reportan que el burnout permaneció hasta un mes después de la intervención. En conclusión, la técnica de entrenamiento en estrategias de afrontamiento con o sin relajación, puede reducir moderadamente el agotamiento emocional y otras sintomatologías de la ansiedad. La falta de pruebas suficientes que apoyen la aplicación de intervenciones para prevenir o reducir sintomatologías del burnout no permitieron realizar meta-análisis

Verificación artroscópica del diagnóstico por resonancia magnética de las lesiones meniscales

La utilización de la Imagen por Resonancia Magnética (IRM) como prueba diagnóstica en la patología de la rodilla, se presenta como alternativa no invasiva fundamental. Se ha diseñado un protocolo a doble ciego junto al servicio de radiodiagnóstico de nuestro hospital a través del cual se han evaluado un total de 31 pacientes donde los hallazgos de la IRM son contrastados con la exploración artroscópica posterior. Para el menisco interno, la precisión diagnóstica de la IRM es del 93 % y del 87% para el externo. Como conclusiones de mayor relieve, la sensibilidad de la exploración fue del 90% para el interno y del 75% para el externo y respecto a la especificidad, en el interno resultó ser del 100% y del 91% en el externo. Los valores predictivo negativo y positivo fueron respectivamente del 85 y 100% en el menisco interno y del 84 y 75% en el externo. Se encontró mayor dificultad diagnóstica en la porción anterior del menisco externo y falta de precisión ocasional en definir el tipo y extensión de la lesión.The use of Magnetic Resonance Imaging (MIR) as a diagnostic trial in the pathology of the knee, has become an important non invasive alternative. We have designed a double blind protocol with the Department of Radiology through we have evaluated 31 patients analyzing the MRI results in relation with the arthroscopic findings. For the medial meniscus, the accuracy of the MRI was 93 % and 87% for the lateral. As main conclusions, the sensibility was 90% for the medial meniscus and 75% for the lateral one and about specificity, we found a result of 100% for the medial meniscus and 91% for the lateral. The negative and positive predictive values were respectively 85% and 100% for the medial and 84% and 75% for the lateral. We noted more diagnostic difficulties in the anterior portion of lateral meniscus and lack of precission in the determination of the type and extension of the meniscal injury

The Role of Epigenetics in Cervical Cancer

Cervical cancer is the fourth most common type of cancer among women worldwide resulting in 528,475 new cases and 268,224 deaths. The principal etiological factor of cervical cancer is the persistent infection with high-risk types of human papillomaviruses (HPV), however is not sufficient, other factors like age, smoking, oral contraceptives, and genetic background are implicated in the development of this neoplasia. Although the understanding of cervical carcinogenesis has been increasing in recent decades, the epigenetic modifications (DNA methylation, histone modification, miRNAs and long non-coding RNAs) and its contribution to the development of cervical cancer remain largely unknown. In the next chapter, we will recapitulate the described findings on the alteration of epigenetic factors that, together with the persistent infection of HPV, could contribute to the malignant and invasive phenotype in cervical cancer