Variación espacial de propiedades físicas de un suelo derivado de cenizas volcánicas sometido a distintas estrategias de mejoramiento de una pradera degradada

Southern Chile presents adequate conditions to develop sheepherding ecosystems. However, from the total of pastures surface in both regions (Los Ríos and Los Lagos) approximately there is a 44% of degraded pastures. Thus, this work is aimed to assess the effects of pastures improvement strategies on spatial variability of soil physical quality. The experiment was realized in the Estación Experimental Agropecuaria Austral, with five pastures on an Andisol: NsF) Naturalized pasture without fertilization; NcF) Improved naturalized pasture with fertilization; Lp+Tr ST) sown Lolium perenne L., Trifolium repens L. pasture with traditional tillage; Lp+Tr CL) sown L.perenne, T.repens pasture with cero tillage; CL) sown pasture with several species L. perenne, T. repens, Bromus valdivianus Phil, Dactylis glomerata L. and Holcus lanatus L. under cero tillage. Following a grid the following parameters were determined: volumetric water content (θc), air conductivity (Kl) and penetration resistance (PR). The data collection was on November 2, 2015, where moderate spatial dependence was determined for all parameters, such that sectors with higher θc (20 Vol.%) in the soil were those that presented lower RP (2,122 kPa) and Kl (0.83 cm s-1). The 30 months since the establishment of pasture improvement strategies have allowed a stabilization of the soil structure that is reflected in the low impact of sheep grazing on the physical parameters evaluated.La zona Sur de Chile presenta condiciones edafoclimáticas adecuadas para el desarrollo de ecosistemas pastoriles. Sin embargo, del total de praderas existentes en las regiones de Los Ríos y Los Lagos, aproximadamente el 44% aún son de baja producción (menor de 4.000 kg MS ha-1 año-1). El objetivo de este trabajo fue evaluar los efectos de estrategias de mejoramiento de praderas sobre la variación espacial de la calidad física del suelo. El ensayo se realizó en la Estación Experimental Agropecuaria Austral, en cinco praderas sobre un Andisol: NsF) Pradera natural sin fertilizar; NcF) Pradera natural fertilizada; Lp+Tr ST) Pradera de Lolium perenne L., Trifolium repens L. con siembra tradicional; Lp+Tr CL) Pradera de L. perenne, T. repens con cero labranza; Polifítica CL) Pradera polifitica de L. perenne, T.repens, Bromus valdivianus Phil, Dactylis glomerata L. y Holcus lanatus L. con cero labranza. En una grilla (5x5 m) se determinó el contenido volumétrico de agua (θc), la conductividad de aire (Kl) y la resistencia a la penetración (RP) del suelo. La recolección de datos fue el 2 de noviembre del 2015 donde se determinó una moderada dependencia espacial para todos los parámetros evaluados, tal que sectores con mayor θc (20 Vol. %) en el suelo fueron los que presentaron menor RP (2.122 kPa) y Kl (0,83 cm s-1). Los 30 meses desde el establecimiento de las estrategias de mejoramiento de praderas han permitido una estabilización de la estructura del suelo que se refleja en el bajo impacto del pastoreo ovino sobre los parámetros físicos

Lung epithelial stem cells and their niches : Fgf10 takes center stage

Throughout life adult animals crucially depend on stem cell populations to maintain and repair their tissues to ensure life-long organ function. Stem cells are characterized by their capacity to extensively self-renew and give rise to one or more differentiated cell types. These powerful stem cell properties are key to meet the changing demand for tissue replacement during normal lung homeostasis and regeneration after lung injury. Great strides have been made over the last few years to identify and characterize lung epithelial stem cells as well as their lineage relationships. Unfortunately, knowledge on what regulates the behavior and fate specification of lung epithelial stem cells is still limited, but involves communication with their microenvironment or niche, a local tissue environment that hosts and influences the behaviors or characteristics of stem cells and that comprises other cell types and extracellular matrix. As such, an intimate and dynamic epithelial-mesenchymal cross-talk, which is also essential during lung development, is required for normal homeostasis and to mount an appropriate regenerative response after lung injury. Fibroblast growth factor 10 (Fgf10) signaling in particular seems to be a well-conserved signaling pathway governing epithelial-mesenchymal interactions during lung development as well as between different adult lung epithelial stem cells and their niches. On the other hand, disruption of these reciprocal interactions leads to a dysfunctional epithelial stem cell-niche unit, which may culminate in chronic lung diseases such as chronic obstructive pulmonary disease (COPD), chronic asthma and idiopathic pulmonary fibrosis (IPF)

Localized structures in convective experiments

In this work we review localized structures appearing in thermo-convective experiments performed in extended (large “aspect ratio”) fluid layers. After a brief general review (not exhaustive), we focus on some results obtained in pure fluids in a Bénard-Marangoni system with non-homogeneous heating where some structures of this kind appear. The experimental results are compared in reference to the most classical observed in binary mixtures experiments or simulations. In the Bénard-Marangoni experiment we present the stability diagram where localized structures appear and the typical situations where these local mechanisms have been studied experimentally. Some new experimental results are also included. The authors want to honor Prof. H. Brand in his 60th. birthday and to thank him for helpful discussions

Phase-bistable patterns and cavity solitons induced by spatially periodic injection into vertical-cavity surface-emitting lasers

Spatial rocking is a kind of resonant forcing able to convert a elf-oscillatory system into a phase-bistable, pattern forming system, whereby the phase of the spatially averaged oscillation field locks to one of two values differing by π. We propose the spatial rocking in an experimentally relevant system the vertical-cavity surface-emitting laser (VCSEL) and demonstrate its feasibility through analytical and numerical tools applied to a VCSEL model. We show phase bistability, spatial patterns, such as roll patterns, domain walls, and phase (dark-ring) solitons, which could be useful for optical information storage and processing purposes

Articular cartilage and changes in Arthritis: Cell biology of osteoarthritis

The reaction patterns of chondrocytes in osteoarthritis can be summarized in five categories: (1) proliferation and cell death (apoptosis); changes in (2) synthetic activity and (3) degradation; (4) phenotypic modulation of the articular chondrocytes; and (5) formation of osteophytes. In osteoarthritis, the primary responses are reinitiation of synthesis of cartilage macromolecules, the initiation of synthesis of types IIA and III procollagens as markers of a more primitive phenotype, and synthesis of active proteolytic enzymes. Reversion to a fibroblast-like phenotype, known as 'dedifferentiation', does not appear to be an important component. Proliferation plays a role in forming characteristic chondrocyte clusters near the surface, while apoptosis probably occurs primarily in the calcified cartilage

CB-SC ameliorate allogeneic responses via exosomal component in vitro.

This data set contains sample files for each figure used in the article titled: Cord Blood Derived-Multipotent Stem Cells Ameliorate Alloreactive Responses and this Effect is Associated with Exosomal Microvesicles in vitroTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV