Search results for "Heterogeneity."
showing 10 items of 388 documents
Interclonal heterogeneity in a human epithelioid-sarcoma cell line (Gru-1)
1994
Three clonal sub-populations, GRU-IA, GRU-IB, and GRU-IC, isolated from the human epithelioid sarcoma cell line GRU-I, were characterized morphologically, cytogenetically and with regard to proliferation kinetics. Immunocytochemically, major differences became evident in the expression of cytokeratin 18 and neurofilament proteins, which are indicative for epithelial and neural differentiation respectively. Vimentin, a mesenchymal differentiation marker, however, could be detected in all tumor cells of each sub-population. Laminin, a major compound of basement membranes, formed abundant intercellular network-like patterns in GRU-IB and GRU-IC, whereas GRU-IA was characterized by a diffuse in…
Novel Approaches for Glioblastoma Treatment: Focus on Tumor Heterogeneity, Treatment Resistance, and Computational Tools
2019
BACKGROUND: Glioblastoma (GBM) is a highly aggressive primary brain tumor. Currently, the suggested line of action is the surgical resection followed by radiotherapy and treatment with the adjuvant temozolomide (TMZ), a DNA alkylating agent. However, the ability of tumor cells to deeply infiltrate the surrounding tissue makes complete resection quite impossible, and in consequence, the probability of tumor recurrence is high, and the prognosis is not positive. GBM is highly heterogeneous and adapts to treatment in most individuals. Nevertheless, these mechanisms of adaption are unknown. RECENT FINDINGS: In this review, we will discuss the recent discoveries in molecular and cellular heterog…
Retrieving and Validating Leaf and Canopy Chlorophyll Content at Moderate Resolution: A Multiscale Analysis with the Sentinel-3 OLCI Sensor
2021
ESA’s Eighth Earth Explorer mission “FLuorescence EXplorer” (FLEX) will be dedicated to the global monitoring of the chlorophyll fluorescence emitted by vegetation. In order to properly interpret the measured fluorescence signal, essential vegetation variables need to be retrieved concomitantly. FLEX will fly in tandem formation with Sentinel-3 (S3), which conveys the Ocean and Land Color Instrument (OLCI) that is designed to characterize the atmosphere and the terrestrial vegetation at a spatial resolution of 300 m. In support of FLEX’s preparatory activities, this paper presents a first validation exercise of OLCI vegetation products against in situ data coming from the 2018 FLEXSense cam…
An Overview of the Regional Experiments for Land-Atmosphere Exchanges 2012 (Reflex 2012) Campaign
2015
The REFLEX 2012 campaign was initiated as part of a training course on the organization of an airborne campaign to support advancement of the understanding of land-atmosphere interaction processes. This article describes the campaign, its objectives and observations, remote as well as in situ. The observations took place at the experimental Las Tiesas farm in an agricultural area in the south of Spain. During the period of ten days, measurements were made to capture the main processes controlling the local and regional land-atmosphere exchanges. Apart from multi-temporal, multi-directional and multi-spatial space-borne and airborne observations, measurements of the local meteorology, energy…
Lissencephalic syndromes: brain and beyond
2009
Lissencephaly has been long maintained a malformation involving only the brain. Classic lissencephaly includes agyria and pachygyria and it is the most severe form of malformations derived from abnormal neuronal migration. It is defined as a smooth or nearly smooth cerebral surface with absence of normal sulci and gyria. It encompasses a group of syndromes which show many different clinical conditions. Four groups are actually distinguished: classic lissencephaly variants, other lissencephalies including forms with unknown pathogenesis, microlissencephaly spectrum and Cobblestone cortical malformations. Several genes and proteins are involved in this syndromic spectrum and each year new mol…
Clinical relevance of genetic heterogeneity in HCV
2010
Infection by HCV affects an estimated 170 million people worldwide and it represents one of the major causes of liver transplantation and a heavy burden to healthcare systems. As with many other RNA viruses, HCV is characterized by very high levels of genetic variation, which have been associated to differences in disease progression and efficiency of antiviral treatment. Studies show many contradictory results and little consensus on such associations. Nevertheless, some general guidelines translating research results to clinical practice have been postulated. Here, we review the main research results obtained on HCV variation so far and explore the reasons for their lack of congruence und…
Anatomy of Cartel Contracts
2013
We study cartel contracts using data on 18 contract clauses of 109 legal Finnish manufacturing cartels. One third of the clauses relate to raising profits; the others deal with instability through incentive compatibility, cartel organization, or external threats. Cartels use three main approaches to raise profits: Price, market allocation, and specialization. These appear to be substitutes. Choosing one has implications on how cartels deal with instability. Simplifying, we find that large cartels agree on prices, cartels in homogenous goods industries allocate markets, and small cartels avoid competition through specialization.
Network structure and optimal technological innovation
2019
The role of networks in the emergence, diffusion and evolution of technological innovations has attracted much theoretical and empirical attention. Yet, much of the work has explored the role of undirected and homogeneous networks. In real cases, many networks are directed. The flow of information, benefits or observations is directed from one node towards another node. Real networks are also heterogeneous, for example, few nodes have a high degree while many others have a low degree. In this article, we report on the results of an evolutionary agent-based model in which a group of agents, in our case firms, collectively search a complex (rugged) technological landscape and observe each oth…
SMEs' heterogeneity at the extensive margin and within the intensive margin of trade
2021
In this paper, we contribute to the literature on firm-heterogeneity and trade, by looking not only at the firm-level determinants of trade participation (i.e. extensive margin) but also at differences between firms with different levels of trade intensity (i.e. intensive margin). Further, we compare firms that are born ‘local’ and display different scales of international exposure to firms that are born ‘global’, i.e. access international markets soon after their birth. Using a large World Bank dataset of SMEs from 112 countries and qualitative dependent variable models, our analysis uncovers the heterogeneity of SMEs not only at the extensive margin but also within the intensive margin of…
On Behavioral Heterogeneity
2006
An index of “behavioral heterogeneity” for every finite population of households is defined. It is shown that the higher the index of behavioral heterogeneity the less sensitive depends the aggregate consumption expenditure ratio upon prices. As a consequence, a high index implies a tendency for the Jacobian of aggregate demand to have a dominant negative diagonal.