Organization of the dorsal lateral geniculate nucleus in the mouse

AbstractThe dorsal lateral geniculate nucleus (dLGN) of the thalamus is the principal conduit for visual information from retina to visual cortex. Viewed initially as a simple relay, recent studies in the mouse reveal far greater complexity in the way input from the retina is combined, transmitted, and processed in dLGN. Here we consider the structural and functional organization of the mouse retinogeniculate pathway by examining the patterns of retinal projections to dLGN and how they converge onto thalamocortical neurons to shape the flow of visual information to visual cortex.</jats:p

Turbulent fluid acceleration generates clusters of gyrotactic microorganisms

The motility of microorganisms is often biased by gradients in physical and chemical properties of their environment, with myriad implications on their ecology. Here we show that fluid acceleration reorients gyrotactic plankton, triggering small-scale clustering. We experimentally demonstrate this phenomenon by studying the distribution of the phytoplankton Chlamydomonas augustae within a rotating tank and find it to be in good agreement with a new, generalized model of gyrotaxis. When this model is implemented in a direct numerical simulation of turbulent flow, we find that fluid acceleration generates multi-fractal plankton clustering, with faster and more stable cells producing stronger clustering. By producing accumulations in high-vorticity regions, this process is fundamen- tally different from clustering by gravitational acceleration, expanding the range of mechanisms by which turbulent flows can impact the spatial distribution of active suspensions.Comment: 5 pages, 4 figure

A Machine Learning Application Based on Giorgio Morandi Still-Life Paintings to Assist Artists in the Choice of 3D Compositions

The authors present a system built to generate arrangements of threedimensional models for aesthetic evaluation, with the aim being to support an artist in their creative process. The authors explore how this system can automatically generate aesthetically pleasing content for use in the media and design industry, based on standards originally developed in master artworks. They then demonstrate the effectiveness of their process in the context of paintings using a collection of images inspired by the work of the artist Giorgio Morandi (Bologna, 1890–1964). Finally, they compare the results of their system with the results of a well-known Generative Adversarial Network (GAN)

Interneurons in the mouse visual thalamus maintain a high degree of retinal convergence throughout postnatal development

Background The dorsal lateral geniculate nucleus (dLGN) of the mouse thalamus has emerged as a powerful experimental system for understanding the refinement of developing sensory connections. Interestingly, many of the basic tenets for such developmental remodeling (for example, pruning of connections to form precise sensory maps) fail to take into account a fundamental aspect of sensory organization, cell-type specific wiring. To date, studies have focused on thalamocortical relay neurons and little is known about the development of retinal connections onto the other principal cell type of dLGN, intrinsic interneurons. Here, we used a transgenic mouse line in which green fluorescent protein (GFP) is expressed within dLGN interneurons (GAD67-GFP), making it possible to visualize them in acutely prepared thalamic slices in order to examine their morphology and functional patterns of connectivity throughout postnatal life. Findings GFP-expressing interneurons were evenly distributed throughout dLGN and had highly complex and widespread dendritic processes that often crossed eye-specific borders. Estimates of retinal convergence derived from excitatory postsynaptic potential (EPSP) amplitude by stimulus intensity plots revealed that unlike relay cells, interneurons recorded throughout the first 5 weeks of life, maintain a large number (approximately eight to ten) of retinal inputs. Conclusions The lack of pruning onto interneurons suggests that the activity-dependent refinement of retinal connections in dLGN is cell-type specific. The high degree of retinal convergence onto interneurons may be necessary for these cells to provide both widespread and local forms of inhibition in dLGN

Heparin-releasable platelet factor 4 in patients with coronary artery disease

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Marshallian labor market pooling: evidence from Italy

This paper employs a unique Italian data source to take a comprehensive approach to labor market pooling. It jointly considers many different aspects of the agglomeration labor market relationship, including turnover, learning, matching, and hold up. It also considers labor market pooling from the perspective of both workers and firms and across a range of industries. The paper reports a general positive relationship of turnover to local population density, which is consistent with theories of agglomeration and uncertainty. The paper also finds evidence of onthejob learning that is consistent with theories of labor pooling, labor poaching, and hold up. In addition, the paper provides evidence consistent with agglomeration improving job matches. However, the labor market pooling gains that we measure are small in magnitude and seem unlikely to account for a substantial share of the agglomeration benefits accruing to worker and firms

Caracterización molecular y bioquímica de mutantes M3 de arroz (Oryza sativa indica L. VAR. CR5272) en condiciones de estrés salino

El arroz es un cultivo de gran importancia a nivel mundial, ya que es la base de la alimentación de 2/3 partes de su población. En Costa Rica este grano representa el 20 % de la ingesta calórica diaria, por lo que es imprescindible garantizar la producción de este alimento frente a problemas ambientales como la salinidad. Desde la década de 1920 se ha utilizado la inducción de mutaciones para generar variedades nuevas, en arroz la metodología más utilizada es la inducción de mutaciones por radiación gamma. Las técnicas moleculares y el cultivo in vitro se han empleado para reducir el tiempo en la selección y caracterización de mutantes con características de interés. En el presente trabajo se regeneraron mutantes de arroz a partir de callos embriogénicos irradiados a 40 Gy y seleccionados con 150 mM de NaCl. Se lograron obtener 7 plantas hermanas de la línea I de las cuales 5 mostraron tolerancia a la salinidad y 2 plantas sensibilidad. Se determinaron los cambios genéticos por AFLP, así como los cambios en los patrones de metilación, expresión relativa de los genes CYSB, SAMDC, SAMS y HKT2 y concentración de proteínas totales y contenido de clorofila a y b en los mutantes M3 de la línea I. Las características diferenciales más evidentes se observaron en el cambio de los niveles de expresión de los genes CYSB, SAMDC, SAMS y HKT2, así como una mayor concentración de clorofila en las plantas tolerantes, respecto a los controles, también se encontró una mayor concentración de proteínas totales en las plantas tolerantes, en comparación a las plantas control en salinidad.Rice is a crop of great worldwide importance, because it is the basis of the diet of 2/3 of its population. In Costa Rica this grain represents 20% of the daily caloric intake, so it is essential to guarantee the production of this food against environmental problems such as salinity. Since the decade of the 20's has been used the induction of mutations to generate new varieties, in rice the methodology most used is gamma radiation. Molecular techniques and in vitro culture have been used to reduce the time in the selection and characterization of mutants with characteristics of interest. In the present work, rice mutants were regenerated from embryogenic calli irradiated at 40 Gy and selected with 150 mM NaCl. We managed to obtain 7 sister plants of line I of which 5 showed tolerance and 2 plants sensitivity to salinity. The genetic changes were determined by AFLP, as well as changes in methylation patterns by MSAP, relative expression of the CYSB, SAMDC, SAMS and HKT2 genes and total protein concentration and chlorophyll a and b content in the M3 mutants of line I. The most evident differential characteristics were observed in the change of the expression levels of the CYSB, SAMDC, SAMS and HKT2 genes, as well as a higher concentration of chlorophyll in the tolerant plants, compared to the controls, as well as a higher concentration of total proteins in tolerant plants, compared to control plants in salinity.Universidad de Costa Rica/[801-B6-655]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Ciencias Básicas::Maestría Académica en Biología con énfasis en Genética y Biología Molecula

Resolved Mid-Infrared Emission Around AB Aur and V892 Tau with Adaptive Optics Nulling Interferometric Observations

We present the results of adaptive optics nulling interferometric observations of two Herbig Ae stars, AB Aur and V892 Tau. Our observations at 10.3 microns show resolved circumstellar emission from both sources. Further analysis of the AB Aur emission suggests that there is an inclined disk surrounding the star. The diameter of the disk is derived to be 24 to 30 AU with an inclination of 45 to 65 degrees from face-on, and a major-axis PA of 30 +/- 15 degrees (E of N). Differences in the physical characteristics between the mid-IR emission and emission at other wavelengths (near-IR and millimeter), found in previous studies, suggest a complex structure for AB Aur's circumstellar environment, which may not be explained by a disk alone. The similarity in the observed size of AB Aur's resolved emission and that of another Herbig Ae star, HD 100546, is likely coincidental, as their respective evolutionary states and spectral energy distributions suggest significantly different circumstellar environments.Comment: 11 pages, 1 figure, Accepted for publication in ApJ Letter