INVOLVEMENT OF THE ENDOCANNABINOID SYSTEM IN THE EPENDYMOGLIAL RESPONSE TO SPINAL CORD REGENERATION IN THE MEXICAN AXOLOTL, Ambystoma mexicanum

Research into the molecular mechanisms of the psychoactive effects of cannabis has led to the discovery of the endocannabinoid system (ECS), a neuromodulatory system conserved throughout the animal kingdom. Little is known about its function in mammals, but there is evidence suggesting its contributions in the cellular processes that are important in CNS development and are conserved during CNS regeneration. However, these studies focussed primarily on mammals, which display limited abilities to regenerate after traumatic CNS injury. Furthermore, nothing is known regarding the role of endocannabinoids in CNS regeneration-competent species like the Mexican axolotl, one of the few vertebrates that can regenerate their spinal cord. The current study investigates the potential role of the ECS in influencing the pro-regenerative response observed in the axolotl spinal cord. I provide evidence that the main ECS receptor in the CNS (CB1) is upregulated in the regenerating caudal spinal cord and tail tissues of larval axolotls at 4 hours post amputation, lasting until 14 days post amputation. By performing immunofluorescence studies on these tissues, I demonstrate the expression of this receptor mainly in the ependymal region. In addition, bath application of the CB1 inverse agonist, AM251, significantly inhibited caudal growth of the spinal cord and tail by 7 days post amputation. The current study also identified an upregulation in a second ECS receptor, CB2, at 7- and 14-days post amputation. Immunofluorescence analysis revealed the localization of this receptor to the subependymal regions within the spinal cord. Furthermore, inhibition with the CB2 inverse agonist, AM630, similarly demonstrated an inhibition in spinal cord and tail regeneration by 7 days post amputation. An assessment of CB1 and CB2 expression was performed by identifying their localization in bromodeoxyuridine-positive (proliferating) and doublecortin-positive (differentiating neuronal) cells in 7-day regenerate tissue. These studies are the first to examine the role of the ECS during spinal cord regeneration in a regeneration-competent vertebrate and may aid in developing novel therapies for human nervous system injuries or pathologies

COVIDetect: A Desktop Application as a Diagnostic Tool for Novel Coronavirus (COVID-19) Pneumonia in Chest X-ray Images Using Convolutional Neural Network

The COVID-19 pandemic has heavily affected the well-being of people worldwide. Current diagnostic tools, like the RT-PCR, are expensive and time-consuming; thus, there is a need for cheaper and faster means of COVID-19 detection. This study proposes using a desktop application with a convolutional neural network (CNN) and visual analysis as a supplementary diagnostic tool for detecting COVID-19 pneumonia in chest X-ray images. The CNN used is a sequential Keras model that was trained and tested through eight epochs using an augmented dataset. Random data augmentation techniques applied were rotation and horizontal flipping, which increased the total images used to 13,584. Visual analysis was created using the Grad-CAM algorithm to determine patterns in chest X-ray images. These were implemented in a desktop application and evaluated by a professional pulmonologist. Results showed that the CNN achieved an average accuracy rate of 97.96% among the three classes, which was superior among related studies. The CNN also achieved a precision, recall, and F1-score of 99.67%, 99.62%, and 99.64% respectively for COVID-19 pneumonia, 99.26%, 94.83%, and 96.99% respectively for viral pneumonia, and 95.12%, 99.42%, and 97.22% respectively for normal chest X-ray images. Meanwhile, the visual analysis was also accurate, as evaluated by a professional pulmonologist, where patterns of haziness were determined. Hence, this could serve as an effective supplementary diagnostic tool for healthcare professionals for faster and more accurate diagnosis of COVID-19 and viral pneumonia patients

Elevación del eje de corona de la presa de depósito de relave - Etapa I, Suyckutambo – Cuzco

Publicación a texto completo no autorizada por el autorRealiza un estudio técnico del crecimiento del eje de corona de la presa de depósito de relave Suyckutambo Etapa I, que comprende hasta la cota 4794.5 con el método de disposición “Aguas Abajo”. Ubicada en en el distrito Suyckutambo, provincia Espinar del departamento Cusco, a una altitud entre los 4500 y 5 000 m.s.n.m. La unidad Suyckutambo está emplazada sobre la formación denominada Grupo Tacaza, conformado por un conjunto de rocas compuestas por basaltos y arcosas en la parte baja y aglomerados de andesita con tobas dacíticas en la parte alta; formada por una secuencia de vulcanismos correspondiente a la segunda fase de la orogénesis andina, y se ha depositado a partir de la fase de distensión consecutiva al plegamiento del oligoceno inferior. El depósito de relaves de la unidad minera Suyckutambo, está conformado por un dique de arranque de 10 metros de altura (Etapa 0), conformado por material de préstamo, lo que ha permitido depositar relaves (Etapa I). El dique tiene talud aguas arriba de 1.5H:1.0V y aguas abajo de 2.0H:1.0V. Para que la presa de depósitos de relave se encuentre en condiciones favorables de estabilidad se realizaron trabajos de movimientos de tierra; conformación del dique mediante la colocación de material de relave cicloneado (relave grueso), bajo un continuo monitoreo compactado al 95% en capas de 0.30m, para llegar hasta la cota 4794.5 como parte de la Etapa I, realizando un total de 45 capas y con un contenido de humedad menor a 15.6. Trabajos de impermeabilización de vaso talud aguas arriba con geomenbrana HDPE 1.5mm para evitar problemas de filtración. Con respecto a las obras civiles, toda la cimentación que ocupará el dique final será impermeabilizada con material de baja permeabilidad (material arcilloso); se realizaron sistemas de drenajes el cual consta de un dren chimena, vertical y horizontal conformado por arena gravosa, cuyo fin es derivar las aguas de escorrentía y las aguas de filtración del cuerpo de dique, si es que fuera el caso, a una poza de paso, derivándolo a planta para su reutilización (recirculación). Con finalidad de proveer estabilidad en la base del talud se realizó la construcción de un sistema de muro gavión y colindante a la estructura el dren vertical. La presente tesis contempla la actualización de las condiciones geotécnicas de la presa de depósitos de relave hasta la cota 4794.5, los estudios se basaron en el análisis de estabilidad física de taludes para lo cual se utilizó el programa de cómputo SLIDE (Rocsience, 2003) versión 6. Se realizaron ensayos de mecánica de suelos de campo para la conformación del dique hasta la cota 4794.5. Para los monitoreos geotécnicos se realizó la instrumentación mediante sondeos piezométricos el cual permite el control de la evolución de la profundidad del agua en el terreno y las presiones intersticiales, se instalaron 3 piezómetros. Con el objetivo de medir los asentamientos y desplazamientos horizontales, se instalaron 3 hitos de control en la corona del dique, para los monitoreos topográficos.Tesi

Reductive Elimination at Carbon under Steric Control

It has been previously demonstrated that stable singlet electrophilic carbenes can behave as metal surrogates in the activation of strong E-H bonds (E = H, B, N, Si, P), but it was believed that these activations only proceed through an irreversible activation barrier. Herein we show that, as is the case with transition metals, the steric environment can be used to promote reductive elimination at carbon centers

Proyecto app paw’s home

En los últimos años, las mascotas han sido una gran compañía para muchas familias, poco a poco la mayoría de los hogares tenía siempre una mascota como parte de la familia que brindaba amor a todos los miembros. Sin embargo, en muchas ocasiones los dueños tienen muchos pendientes adicionales y no logran tener suficiente tiempo para cuidar a sus mascotas. Luego de analizar este problema, se nos ocurrió una idea de negocio que pueda facilitar el acceso a los dueños a encontrar cuidadores que estén dispuestos a ofrecer sus hogares para el cuidado de las mascotas brindando una opción adicional a los dueños para no dejarlo en veterinarias donde probablemente la mascota pueda estresarse con la acumulación de muchos animales. Asimismo, luego de una ardua investigación logramos averiguar que no existe un modelo de negocio similar en el Perú, lo cual nos generó mucha intriga teniendo en cuenta que el mercado de mascotas es muy amplio y esta opción es indispensable para muchas personas que tienen poca disponibilidad de tiempo o suelen recurrir a viejas frecuentes. Es ahí donde nace Paw’s Home, un modelo de negocio presentado bajo un aplicativo móvil donde las personas podrán acceder de una manera fácil y ponerse en contacto con personas que están dispuestas a cuidar a sus mascotas en sus hogares o espacios adecuados. Brindando un ingreso adicional a los cuidadores y una solución para los usuarios (dueños).In recent years, pets have been a great company for many families, little by little most homes always had a pet as part of the family that provided love to all members. However, on many occasions’ vendor owners become very busy and do not have someone who can care for their pet. That is why we came up with a business idea that can facilitate access for owners to find caregivers who are willing to offer their homes for the care of pets, providing an additional option to the owners not to leave it in veterinarians where they probably become stressed with the accumulation of many animals. Likewise, after an arduous investigation we were able to find out that there is no similar business model in Peru, which generated a lot of intrigue considering that the pet market is very wide, and this option is essential for many people who have little availability. of time or they usually resort to frequent old women. This is where Paw's Home was born, a business model presented under a mobile application where people can easily access and get in touch with people who are willing to take care of their pets in their homes or suitable spaces. Providing additional income for caregivers and a quick solution for pet owners.Trabajo de investigació

Nivel de contaminación fecal en hortalizas expendidas en mercados de Huánuco y su relación en el riego con aguas residuales no tratadas

Objetive. To determine the level of faecal contamination in vegetables sold in the Huánuco marketsand their relationship in wastewater irrigation untreated.Methods. Was designe an correlational study, with 84 vegetables samples corresponding to theHuánuco markets and also 84 irrigation water samples of the vegetables in study, during 2014. Thedata were obtained by laboratory tests and observation guides. Th determination of E. coli was madefor the membrane filter method. Was performed an bivariate analysis through the chi square test.Results. The prevalence of E. coli was 34,5%(29/84). The chinese chives showed higher prevalenceof contamination, continued of coriander, parsley and radish. Were found statistically significantassociations (P≤0,05) among the contamination irrigation wáter and the prevalence of E. coli in thevegetables as chinese chives, coriander, parsley and radish.Conclusions. The prevalence of E. coli in the vegetables were high and relate with the fecalcontamination of irrigation wáter.ObjetivoDeterminar el nivel de contaminación fecal en hortalizas expendidas en los mercados de Huánuco ysu relación en el riego con aguas residuales no tratadas.MétodosSe diseñó un estudio correlacional, con 84 muestras de hortalizas pertenecientes a los mercados deHuánuco y también 84 muestras de agua de riego de las hortalizas en estudio, durante el 2014. Losdatos se obtuvieron mediante exámenes de laboratorio y guías de observación. La determinación deE. coli fue hecha por el método de filtros de membrana. Se realizó un análisis bivariado mediante laprueba Chi-cuadrada.ResultadosLa prevalencia de E. coli fue del 34.5% (29/84). El cebollino chino mostró mayor prevalencia decontaminación, seguido de culantro, perejil y rabanito. Se encontraron asociaciones estadísticassignificativas (P≤0.05) entre la contaminación de agua de riego y la prevalencia de E. coli en lashortalizas de tipo cebollino chino, culantro, perejil y rabanito.ConclusionesLa prevalencia de E. coli en las hortalizas fueron altas y se relacionan con la contaminación fecal deagua de riego

A pattern of care analysis: Prosthetic rehabilitation of head and neck cancer patients after radiotherapy

Background While some medical associations provide guidelines for the implant‐prosthetic rehabilitation of head and neck cancer patients, the circulation and implementation in the everyday routine of practicing dentists remain unknown. Purpose To analyze patterns of care for the prosthetic rehabilitation of head and neck cancer patients after radiotherapy in German speaking countries. Materials and methods An online survey consisting of 34 questions separated into three sections, (a) general inquiries, (b) treatment concepts, and (c) patient cases, was forwarded to university hospital departments for Prosthetic Dentistry and Oral and Maxillofacial Surgery, and members of different medical associations. Statistical differences between groups were analyzed using chi‐squared test (P < .05). Results From May to October 2019, 118 participants completed the survey. The majority practiced in university hospitals, had more than 5 years of work experience, and reported to be involved in <10 post radiation prosthetic rehabilitation cases per year. Rehabilitation protocols involving dental implants were implemented by oral/oral‐ and maxillofacial surgeons and prosthetic dentists, while general dentists favored implant‐free solutions. Xerostomia was recognized as a common problem for a successful prosthetic rehabilitation. The subsequent treatment choice with either fixed dental prostheses or removable dentures was divided among participants. Conclusions As treatment planning differed with regard to the participants' field of expertise and work environment, and most practitioners only handle a low number of cases, patients might benefit from centralization in larger institutes with a multidisciplinary structure. A high agreement between the practitioners' treatment concepts and the current state of research was observed. While the choice between a mucosa‐ or tooth‐supported, and an implant‐supported restoration depends on numerous individual factors, guidelines derived from longitudinal studies would enhance evidence‐based treatment in this field

Variation in LOV Photoreceptor Activation Dynamics Probed by Time-Resolved Infrared Spectroscopy

The light, oxygen, voltage (LOV) domain proteins are blue light photoreceptors that utilize a non-covalently bound flavin mononucleotide (FMN) cofactor as the chromophore. The modular nature of these proteins has led to their wide adoption in the emerging fields of optogenetics and optobiology, where the LOV domain has been fused to a variety of output domains leading to novel light-controlled applications. In the present work, we extend our studies of the sub-picosecond to sub-millisecond transient infrared spectroscopy of the isolated LOV domain AsLOV2 to three full-length photoreceptors in which the LOV domain is fused to an output domain: the LOV-STAS protein, YtvA, the LOV-HTH transcription factor, EL222, and the LOV-histidine kinase, LovK. Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate. However significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain. While the rate of adduct formation varies by only 3.6-fold amongst the proteins, the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to sub-millisecond timescales and vary by orders of magnitude depending on the different output function of each LOV domain