Los géneros de Araceas del municipio de Florencia (Caquetá – Colombia)

La familia Araceae es una de las más diversas dentro de las monocotiledóneas, cuyo centro de diversidad es el Neotrópico. En total hay 105 géneros y cerca de 3300 especies a nivel mundial, de los cuales 23 géneros y 447 especies han sido registradas para Colombia. Dado que muchas áreas de Colombia son escasamente muestreadas, en el presente trabajo se contribuye al conocimiento de la diversidad local de este grupo en el municipio de Florencia (Caquetá). Para este trabajo se realizo trabajo de campo y revisión de ejemplares depositados en los herbarios HUAZ de la Universidad de la Amazonia, COAH del Instituto Sinchi y COL de la Universidad Nacional de Colombia. La familia Araceae se encuentra representada en el municipio de Florencia por 16 géneros nativos: Anthurium, Caladium, Dieffenbachia, Dracontium, Heteropsis, Homalomena, Monstera, Montrichardia, Philodendron, Pistia, Rhodospatha, Spathiphyllum, Stenospermation, Syngonium, Urospatha y Xanthosoma, y 3 géneros introducidos a la región Neotrópical (Aglaonema, Alocasia y Colocasia), esto corresponde a un 82 % de los géneros para Colombia. Los géneros Alocasia y Colocasia se han naturalizado, encontrándose grandes poblaciones creciendo espontáneamente en áreas abiertas. El total de morfoespecies encontradas hasta el momento es de 114, aunque todavía se requieren estudios taxonómicos para determinar la identidad de estas especies

Four incident stories

Muchas veces, lo que hacemos en nuestras clases buscando la atención de nuestras estudiantes es “echar cuento”. Ahora, en tiempos de cuarentena, queremos plasmar cuatro cuentos sin buscar denodadamente llamar su curiosidad, sino para convocarles a la reflexión pausada, o no tanto. Dos profesoras nacidas en Colombia y dos profesores, uno también del país andino y otro de la península ibérica, queríamos escribir un cuento, o una carta, a estudiantes y colegas en estos tiempos de pandemia, la primera del siglo XXI, para contarles nuestros abordajes personales y académicos ante el nuevo panorama. Todos nosotros residentes en Bogotá, aunque eso no importa mucho ahora porque a través de la pantalla, sin la presencia física, da igual dónde te encuentres, nos conectamos con la idea de construir un texto a ocho manos, o cuatro textos de a dos manos que sumarán uno solo.Facultad de Periodismo y Comunicación Socia

Glutamate Uptake Triggers Transporter-Mediated GABA Release from Astrocytes

Background: Glutamate (Glu) and c-aminobutyric acid (GABA) transporters play important roles in regulating neuronal activity. Glu is removed from the extracellular space dominantly by glial transporters. In contrast, GABA is mainly taken up by neurons. However, the glial GABA transporter subtypes share their localization with the Glu transporters and their expression is confined to the same subpopulation of astrocytes, raising the possibility of cooperation between Glu and GABA transport processes. Methodology/Principal Findings: Here we used diverse biological models both in vitro and in vivo to explore the interplay between these processes. We found that removal of Glu by astrocytic transporters triggers an elevation in the extracellular level of GABA. This coupling between excitatory and inhibitory signaling was found to be independent of Glu receptor-mediated depolarization, external presence of Ca2+ and glutamate decarboxylase activity. It was abolished in the presence of non-transportable blockers of glial Glu or GABA transporters, suggesting that the concerted action of these transporters underlies the process. Conclusions/Significance: Our results suggest that activation of Glu transporters results in GABA release through reversal of glial GABA transporters. This transporter-mediated interplay represents a direct link between inhibitory and excitatory neurotransmission and may function as a negative feedback combating intense excitation in pathological conditions such as epilepsy or ischemia

Hippocampal state-dependent behavioral reflex to an identical sensory input in rats.

We examined the local field potential of the hippocampus to monitor brain states during a conditional discrimination task, in order to elucidate the relationship between ongoing brain states and a conditioned motor reflex. Five 10-week-old Wistar/ST male rats underwent a serial feature positive conditional discrimination task in eyeblink conditioning using a preceding light stimulus as a conditional cue for reinforced trials. In this task, a 2-s light stimulus signaled that the following 350-ms tone (conditioned stimulus) was reinforced with a co-terminating 100-ms periorbital electrical shock. The interval between the end of conditional cue and the onset of the conditioned stimulus was 4±1 s. The conditioned stimulus was not reinforced when the light was not presented. Animals successfully utilized the light stimulus as a conditional cue to drive differential responses to the identical conditioned stimulus. We found that presentation of the conditional cue elicited hippocampal theta oscillations, which persisted during the interval of conditional cue and the conditioned stimulus. Moreover, expression of the conditioned response to the tone (conditioned stimulus) was correlated with the appearance of theta oscillations immediately before the conditioned stimulus. These data support hippocampal involvement in the network underlying a conditional discrimination task in eyeblink conditioning. They also suggest that the preceding hippocampal activity can determine information processing of the tone stimulus in the cerebellum and its associated circuits

Phylogenomic analysis of a 55.1 kb 19-gene dataset resolves a monophyletic Fusarium that includes the Fusarium solani Species Complex

Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user¿s needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option availabl

Influence of turbulence, density, phase change, and phase interfaces models on the performance of the numerical simulation of a two-phase closed thermosyphon.

A heat pipe can be considered a highly effective thermal conduction device, which is especially desirable in heat transfer operations in order to ensure high energy efficiency. However, the operation of heat pipes comprises different heat and mass transfer phenomena, such phase change, heat conduction and convection, solid-liquid and vapor-liquid surface interactions, surface vaporization, and nucleate boiling. Therefore, modelling heat pipes is a highly complex task that demands detailed knowledge of the physical phenomena involved and choosing suitable theoretical models to obtain a good representation of the real nature of the heat and mass transfer processes. In this study, some models and parameters available in the commercial CFD software ANSYS Fluent for turbulence, density, phase change, and phase interfaces were examined to determine their influence on the prediction of the heat and mass transfer in a two-phased closed thermosyphon (TPCT). The numerical results show that using a turbulence viscous model is not necessary and that a variable density model improves the temperature distribution inside the TPCT. Furthermore, using high mass and energy transfer coefficients during condensation makes the vapor remain close to the saturation temperature. Finally, a sharp interphase model is strongly recommended for this type of process.Un tubo de calor puede ser considerado como un dispositivo con alta conductividad térmica, el cual es frecuentemente usado en procesos de transferencia de calor para garantizar una alta eficiencia energética. Además, la operación de los tubos de calor comprende diferentes fenómenos de transferencia de calor y masa, como cambio de fase, conducción y convección, interacciones sólido-líquido y vapor-líquido, evaporación y ebullición nucleada, además de otras. Por lo tanto, el modelado de los tubos de calor es un proceso de alta complejidad, el cual requiere el conocimiento del fenómeno físico allí presente para escoger los modelos teóricos adecuados, logrando así, obtener una representación aceptable de los procesos de transferencia de masa y energía que naturalmente se presentan. En este trabajo, algunos modelos y parámetros disponibles en el software ANSYS Fluent como el modelo de viscosidad, densidad, cambio de fase e interfaz entre fases fueron analizados para determinar su influencia sobre la predicción de la transferencia de masa y energía en un termosifón cerrado de dos fases. Los resultados numéricos mostraron que, usar un modelo de viscosidad turbulenta no es necesario, un modelo de densidad variable mejora la distribución de la temperatura y que un modelo de interfaz Sharp es altamente recomendado en estos procesos

Vascular injuries of the neck and thoracic inlet: helical CT-angiographic correlation

Imaging evaluation of patients suspected to have arterial injuries of the neck has traditionally been performed by using conventional angiography as an alternative to surgical exploration. However, there has been recent interest in and growing experience with use of noninvasive imaging techniques for the assessment of vascular injuries. Contrast material-enhanced helical computed tomographic (CT) angiography is increasingly being used to evaluate trauma patients in stable condition who are at risk for vascular injuries. It allows characterization of traumatic vascular lesions in the neck such as partial or complete occlusion, pseudoaneurysm, intimal flap, dissection, and arteriovenous fistula. In the same setting, CT angiography provides valuable additional information about the cervical soft tissues, aerodigestive tract, spinal canal, and spinal cord. In cases of penetrating gunshot injuries, the trajectory of the bullet and the locations of fragments can be assessed. CT angiography may be limited by artifacts from metallic fragments and occasionally by abundant soft-tissue air or streak artifacts in the shoulders. In such cases, conventional angiography is necessary for optimal assessment of vascular injuries. CT angiography can be used as a noninvasive alternative to conventional angiography in patients suspected to have vascular injuries but without initial indications for surgical treatment