The RANKL-RANK Axis: A Bone to Thymus Round Trip

The identification of Receptor activator of nuclear factor kappa B ligand (RANKL) and its cognate receptor Receptor activator of nuclear factor kappa B (RANK) during a search for novel tumor necrosis factor receptor (TNFR) superfamily members has dramatically changed the scenario of bone biology by providing the functional and biochemical proof that RANKL signaling via RANK is the master factor for osteoclastogenesis. In parallel, two independent studies reported the identification of mouse RANKL on activated T cells and of a ligand for osteoprotegerin on a murine bone marrow-derived stromal cell line. After these seminal findings, accumulating data indicated RANKL and RANK not only as essential players for the development and activation of osteoclasts, but also for the correct differentiation of medullary thymic epithelial cells (mTECs) that act as mediators of the central tolerance process by which self-reactive T cells are eliminated while regulatory T cells are generated. In light of the RANKL-RANK multi-task function, an antibody targeting this pathway, denosumab, is now commonly used in the therapy of bone loss diseases including chronic inflammatory bone disorders and osteolytic bone metastases; furthermore, preclinical data support the therapeutic application of denosumab in the framework of a broader spectrum of tumors. Here, we discuss advances in cellular and molecular mechanisms elicited by RANKL-RANK pathway in the bone and thymus, and the extent to which its inhibition or augmentation can be translated in the clinical arena

Soluble Factors on Stage to Direct Mesenchymal Stem Cells Fate

Mesenchymal stem cells (MSCs) are multipotent stromal cells that are identified by in vitro plastic adherence, colony-forming capacity, expression of a panel of surface molecules, and ability to differentiate at least toward osteogenic, adipogenic, and chondrogenic lineages. They also produce trophic factors with immunomodulatory, proangiogenic, and antiapoptotic functions influencing the behavior of neighboring cells. On the other hand, a reciprocal regulation takes place; in fact, MSCs can be isolated from several tissues, and depending on the original microenvironment and the range of stimuli received from there, they can display differences in their essential characteristics. Here, we focus mainly on the bone tissue and how soluble factors, such as growth factors, cytokines, and hormones, present in this microenvironment can orchestrate bone marrow-derived MSCs fate. We also briefly describe the alteration of MSCs behavior in pathological settings such as hematological cancer, bone metastasis, and bone marrow failure syndromes. Overall, the possibility to modulate MSCs plasticity makes them an attractive tool for diverse applications of tissue regeneration in cell therapy. Therefore, the comprehensive understanding of the microenvironment characteristics and components better suited to obtain a specific MSCs response can be extremely useful for clinical use

Popular knowledge and conservation perspectives on the inland turtles at the lower part of La Miel river (Colombia)

La parte baja de la cuenca del río La Miel está ubicada al nororiente del departamento de Caldas y alberga cinco de las especies de tortugas continentales registradas para Colombia. Durante mayo a septiembre de 2014 se recopiló información mediante la aplicación de un cuestionario semiestructurado a 101 residentes de la cuenca hidrográfica, acerca del conocimiento y uso de las tortugas (alimento, comercio y mascota) en la zona. La encuesta incluyó información personal de acuerdo con el sexo, ocupación principal (ama de casa, pescador/lanchero, agricultor/jornalero, mayordomo), tipo de habitante (nativos, extranjeros) y conocimiento y uso de las tortugas. Los resultados sugieren que las tortugas de agua dulce en la zona de estudio, se han reducido debido a una aparente larga historia de utilización por el hombre; principalmente para alimento, uso como mascotas y ocasionalmente por el comercio. Sin embargo, estos datos también sugieren que a pesar del impacto humano el río La Miel podría concentrar un número alto de tortugas a lo largo de la cuenca, lo que resalta la importancia de este sistema acuático como uno de los hábitats más importantes para la conservación de las tortugas de agua dulce en el país. Asimismo, los resultados muestran algunas relaciones relevantes hombre-fauna silvestre, que pueden ser utilizadas para avanzar en nuevos esfuerzos hacia la gestión de la conservación de las tortugas de agua dulce bajo un contexto local y nacional.The lower part of La Miel River, located at the north-east of the Department of Caldas, hosts five Colombian inland turtle species. Information about knowledge and turtles' use (for food, trade, or pets) was recorded using a semi-structured questionnaire applied to 101 watershed residents, from May to September 2014. The survey included personal, knowledge, and use information accordingly to sex, principal work (housewife, fisherman/boatman, farmer/laborer, steward) and inhabitant type (native, foreign). Our results suggest that freshwater turtles in the study area have declined due an apparent long history of human consumption; mainly for food, pet, and occasionally for trade. However, these data also suggest that despite human impact, La Miel River could support a large number of turtles along the basin, underscoring the importance of this aquatic system as one of the most important habitats for the conservation of freshwater turtles in the country. In addition, our results illustrate some relevant human-wildlife relationships, which can be used to advance new efforts toward freshwater turtle management under local and national context

631 rankl knock out mesenchymal stromal cells have an unexpected osteogenic differentiation defect which is improved by a rankl expressing lentiviral vector

Osteoclast-poor RANKL-dependent Autosomal Recessive Osteopetrosis (ARO) is a rare bone disease characterized by an increase in bone density due to the failure of bone resorption by impaired osteoclast formation. Hematopoietic stem cell transplantation is not an effective therapy for this ARO form, since in bone RANKL is produced mainly by cells of mesenchymal origin. Therefore Mesenchymal Stromal Cells (MSC) transplantation together with a gene-therapy strategy to correct RANKL defect in MSC could represent a possible effective therapy. Of note, whether also MSC, besides the osteoclasts, are affected by RANKL deficiency is unknown. To verify this, we established and characterized bone marrow derived MSC (BM-MSC) lines from the Rankl−/− (KO) mouse model, which recapitulates the human disease, and from wild type (WT) mice. No differences were found between KO and WT MSC in terms of morphology, immunophenotype and proliferation capacity. However, KO MSC displayed a reduced clonogenic potential with a decrease in stemness genes expression. KO MSC were able to normally differentiate towards the adipogenic and chondrogenic lineages, while showed a significantly impaired osteogenic differentiation capacity compared to WT MSC, as demonstrated by reduced Alizarin Red staining (ARS) and expression of osteogenic genes. To confirm that this alteration was due to the lack of functional RANKL, we developed a third generation lentiviral vector expressing human soluble RANKL (hsRL) for the genetic correction of KO MSC. We first investigated lentiviral transduction in 293T cells to optimize transduction efficiency at different multiplicity of infection (MOI) ranging from 1 to 100. hsRL production increased proportionally to the MOI and was stable over time. However, the higher the MOI the higher the cytotoxicity observed. Based on these data, we performed a lentiviral hsRL transduction in KO MSC at 20 and 50 MOI, to define the optimal transduction conditions. After transduction 99.5% of MSC were GFP+. While in Rankl−/− control cells the cytokine was not detected, in corrected cells hsRL production and secretion was measurable and comparable to sRL levels in WT mouse. KO MSC stably expressing hsRL showed an improved osteogenic differentiation capacity compared to untransduced KO MSC, as demonstrated by increased ARS and expression of osteogenic genes. Moreover, the expression of RANK receptor in both MSC suggested an autocrine role of sRL as possible mechanism. Our data suggest that restoration of RANKL production in lentiviral-transduced KO MSC might not only allow osteoclast differentiation in Rankl−/− mice upon transplantation, but also improve the osteogenic differentiation defect of KO MSC

Estudio de eficiencia energética de una bicicleta eléctrica urbana cargada con una estación de carga solar fotovoltáica autónoma y su cumplimiento con la regulación ecuatoriana No. ARCERNNR – 002/20

Las bicicletas eléctricas (e-bikes) son un medio de transporte sostenible emergente. Si se adoptan masivamente, ayudarían a enfrentar los desafíos de movilidad humana en las ciudades del mundo. En Cuenca, Ecuador, el Gobierno local construyó ciclovías (13,47 km) que conectan puntos estratégicos, para facilitar y fomentar la movilidad sostenible. Sin embargo, la implementación efectiva de las estrategias de electromovilidad a gran escala conlleva impactos en la red eléctrica, como el aumento de la demanda de energía y la posible disminución de su calidad debido a la distorsión armónica de la corriente de carga de la batería. El propósito de esta investigación es hacer una evaluación preliminar de dichos impactos, mediante el estudio de eficiencia energética de una e-bike urbana cargada con una estación solar fotovoltaica aislada, implementada en el Laboratorio de Micro-Red de la Universidad de Cuenca.La metodología incluye la caracterización experimental del régimen de carga de la batería, el cálculo de la eficiencia energética del vehículo y la evaluación del cumplimiento de la normativa ecuatoriana ARCERNNR–002/20. Los resultados muestran que el cargador de la batería implementa un régimen de carga estandarizado por normas alemanas, entregando 92 % de carga en 4,82 horas. La eficiencia energética promedio de la e-bike es 2,18 kWh/100 millas o 73,77 m/Wh, y una economía de combustible de 1545,1 MPGe. Finalmente, la magnitud de las primeras cuatro componentes armónicas impares y la distorsión armónica total de la corriente de carga supera los límites establecidos por la normativa./E-bikes are an emerging sustainable means of transportation, if adopted massively, they can help face the challenges of human mobility in urban centers worldwide. In Cuenca, Ecuador, the local government built cycle routes (13.47 km) connecting strategic points to facilitate and encourage sustainable mobility. However, the effective implementation of the electromobility strategies at a large scale entails impacts on the power grid, like the increase in the energy demand and the possible decrease of the energy quality due to the harmonic distortion that characterizes the battery’s charging current. This research aims to obtain a primary input to evaluate such impacts through an energy efficiency study of an urban e-bike charged by a standalone solar photovoltaic charging station implemented in the Microgrid Laboratory of Universidad de Cuenca.The methodology includes the experimental characterization of the battery’s charging regime, the vehicle’s energy efficiency calculation, and the evaluation of its compliance with Ecuadorian grid code No. ARCERNNR – 002/20. Results show that the battery’s charger performs a charging regime standardized by German regulations, delivering 92% of charge in 4.82 hours. The e-bike’s calculated average energy efficiency is 2.18 kWh/100 miles or 73.77 m/Wh, and a fuel economy of 1545.1 MPGe. Finally, the magnitude of the first four odd harmonic components and the total harmonic distortion of the charging current exceeds the limits established by the grid code in force

Study of the Energy Efficiency of an Urban E-Bike Charged with a Standalone Photovoltaic Solar Charging Station and its Compliance with the Ecuadorian Grid Code No. ARCERNNR – 002/20

E-bikes are an emerging sustainable means of transportation, if adopted massively, they can help face the challenges of human mobility in urban centers worldwide. In Cuenca, Ecuador, the local government built cycle routes (13.47 km) connecting strategic points to facilitate and encourage sustainable mobility. However, the effective implementation of the electromobility strategies at a large scale entails impacts on the power grid, like the increase in the energy demand and the possible decrease of the energy quality due to the harmonic distortion that characterizes the battery's charging current. This research aims to obtain a primary input to evaluate such impacts through an energy efficiency study of an urban e-bike charged by a standalone solar photovoltaic charging station implemented in the Microgrid Laboratory of Universidad de Cuenca. The methodology includes the experimental characterization of the battery's charging regime, the vehicle's energy efficiency calculation, and the evaluation of its compliance with Ecuadorian grid code No. ARCERNNR – 002/20. Results show that the battery's charger performs a charging regime standardized by German regulations, delivering 92% of charge in 4.82 hours. The e-bike's calculated average energy efficiency is 2.18 kWh/100 miles or 73.77 m/Wh, and a fuel economy of 1545.1 MPGe. Finally, the magnitude of the first four odd harmonic components and the total harmonic distortion of the charging current exceeds the limits established by the grid code in force

Stellar Disks in Aquarius Dark Matter Haloes

We investigate the gravitational interactions between live stellar disks and their dark matter halos, using LCDM haloes similar in mass to that of the Milky Way taken from the Aquarius Project. We introduce the stellar disks by first allowing the haloes to respond to the influence of a growing rigid disk potential from z = 1.3 to z = 1.0. The rigid potential is then replaced with star particles which evolve self-consistently with the dark matter particles until z = 0.0. Regardless of the initial orientation of the disk, the inner parts of the haloes contract and change from prolate to oblate as the disk grows to its full size. When the disk normal is initially aligned with the major axis of the halo at z=1.3, the length of the major axis contracts and becomes the minor axis by z=1.0. Six out of the eight disks in our main set of simulations form bars, and five of the six bars experience a buckling instability that results in a sudden jump in the vertical stellar velocity dispersion and an accompanying drop in the m=2 Fourier amplitude of the disk surface density. The bars are not destroyed by the buckling but continue to grow until the present day. Bars are largely absent when the disk mass is reduced by a factor of two or more; the relative disk-to-halo mass is therefore a primary factor in bar formation and evolution. A subset of the disks is warped at the outskirts and contains prominent non-coplanar material with a ring-like structure. Many disks reorient by large angles between z=1 and z=0, following a coherent reorientation of their inner haloes. Larger reorientations produce more strongly warped disks, suggesting a tight link between the two phenomena. The origins of bars and warps appear independent: some disks with strong bars show no disturbances at the outskirts, while the disks with the weakest bars show severe warps.Comment: 19 pages, 13 figures, accepted MNRAS; fixed compatibility problem in figures 8,

Прототип автоматической системы экстренного торможения транспортного средства

Разработка, сборка и испытание прототипа автономной системы экстренного торможения транспортного средства на основе 8-битного микроконтроллера AVR типа ATmega16 и ультразвукового дальномера HC-SR04, срабатывающей при приближении к объекту на расстояние около 10 см. Программу микроконтроллера будет написана на языке Си с использованием программатора STK-500.Development, assembly and testing of the prototype of the autonomous emergency braking system of a vehicle based on the 8-bit AVR microcontroller type ATmega16 and ultrasonic rangefinder HC-SR04, triggered when approaching the object at a distance of about 10 cm. The program of the microcontroller will be written in C language using the programmer STK -500