16,398 research outputs found
Analysis of chlorophyll fluorescence reveals stage specific patterns of chloroplast-containing cells during Arabidopsis embryogenesis
http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000100012&lng=es&nrm=isoThe basic body plan of a plant is established early in embryogenesis when cells differentiate, giving rise to the apical and basal regions of the embryo. Using chlorophyll fluorescence as a marker for chloroplasts, we have detected specific patterns of chloroplast-containing cells at specific stages of embryogenesis. Non-randomly distributed chloroplast-containing cells are seen as early as the globular stage of embryogenesis in Arabidopsis. In the heart stage of embryogenesis, chloroplast containing cells are detected in epidermal cells as well as a central region of the heart stage embryo, forming a triangular septum of chloroplast-containing cells that divides the embryo into three equal sectors. Torpedo stage embryos have chloroplast-containing epidermal cells and a central band of chloroplast-containing cells in the cortex layer, just below the shoot apical meristem. In the walking-stick stage of embryogenesis, chloroplasts are present in the epidermal, cortex and endodermal cells. The chloroplasts appear reduced or absent from the provascular and columella cells of walking-stick stage embryos. These results suggest that there is a tight regulation of plastid differentiation during embryogenesis that generates specific patterns of chloroplast-containing cells in specific cell layers at specific stages of embryogenesis
Nuevos registros de Ceratopogonidae (Diptera) para Argentina y Chile
New records are provided for 22 species of biting midges (Diptera: Ceratopogonidae) from Argentina and Chile, 12 belonging to Forcipomyia Meigen, two to Atrichopogon Kieffer and Culicoides Latreille, and one to Leptoconops Skuse, Dasyhelea Kieffer, Paradasyhelea Macfie, Alluaudomyia Kieffer, Macrurohelea Ingram & Macfie and Palpomyia Meigen. Forcipomyia (F.) harpegonata Wirth & Soria, F. (F.) pictoni Macfie, F. (F.) sexvittata Wirth, F. (Lepidohelea) annulatipes Macfie, F. (L.) kuanoskeles Macfie, F. (Phytohelea) jocosa Saunders and F. (Thyridomyia) nana (Macfie) are firstly recorded from Argentina, and Leptoconops ricardoi Ronderos & Spinelli, Atrichopogon endemicus Spinelli & Marino, Culicoides chacoensis Spinelli & Wirth, Paradasyhelea brevipalpis (Ingram & Macfie) and Alluaudomyia schnacki Spinelli are firstly recorded from Chile. Forcipomyia calchaqui Spinelli & Marino is removed from the subgenus Thyridomyia Saunders and assigned to the subgenus Synthyridomyia Saunders.Se brindan nuevas citas de 22 especies de Ceratopogonidae para Argentina y Chile, de las cuales 12 pertenecen a Forcipomyia Meigen, dos a Atrichopogon Kieffer y Culicoides Latreille, y una a Leptoconops Skuse, Dasyhelea Kieffer, Paradasyhelea Macfie, Alluaudomyia Kieffer, Macrurohelea Ingram & Macfie y Palpomyia Meigen. Forcipomyia (F.) harpegonata Wirth & Soria, F. (F.) pictoni Macfie, F. (F.) sexvittata Wirth, F. (Lepidohelea) annulatipes Macfie, F. (L.) kuanoskeles Macfie, F. (Phytohelea) jocosa Saunders y F. (Thyridomyia) nana (Macfie) son registradas por primera vez para Argentina, mientras que Leptoconops ricardoi Ronderos & Spinelli, Atrichopogon endemicus Spinelli & Marino, Culicoides chacoensis Spinelli & Wirth, Paradasyhelea brevipalpis (Ingram & Macfie) y Alluaudomyia schnacki Spinelli lo son para Chile. Se excluye Forcipomyia calchaqui Spinelli & Marino del subgénero Thyridomyia Saunders y se la asigna a Synthyridomyia Saunders.Fil: Spinelli, Gustavo Ricardo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División EntomologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Marino, Pablo Ignacio. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División EntomologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Gaddi, Ana Laura. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División EntomologÃa; Argentin
Stomach cancer incidence in Southern Portugal 1998-2006:a spatio-temporal analysis
Understanding geographical differences in health, particularly in small areas, became
a major concern of epidemiologists. Geographical association studies and, more recently, several spatial disease mapping studies have emerged due to the development of new spatial statistical tools.
Among other diseases, these methods are being applied to analyze cancer data. However, in this kind of studies, it is of utmost importance to also investigate the influence of temporal variability and that is why spatio-temporal studies became so popular. The aim of this study is to investigate spatial and temporal trends for the incidence of this type of cancer. This retrospective population-based study is based on data on all stomach cancers registered by the Southern Portuguese Cancer Registry (ROR Sul) between 1998 and 2006. Because several studies have underlined the important role of socioeconomic status in cancer risk, information on this variable has also been taken into account. Bayesian hierarchical models were applied to model stomach incidence at a county level and resulting relative risks were used to build risk maps for cancer incidence. Age-Period-Cohort models were also applied.N/
THIRD-PARTY COMPLAINTS AND FIRM PERFORMANCE: AN APPLICATION IN SPANISH BANKING
This article focuses on the impact of third-party complaints on firm performance. We propose two research hypotheses, which are developed from the literature of dissatisfaction, emotions, and economics. The methodology is based on an event study to estimate variation in firm share returns in the stock market due to the publication of the Annual Complaints Service Report by the Bank of Spain; as well as a regression analysis to examine the impact of the number of complaints per branch on the variation obtained. The empirical focus is on a sample of eleven banks to which complaints were made and which were quoted on the Spanish Stock Exchange between 1992 and 2001. The results show a negative impact of the publication of these annual complaint reports on the share returns of the banks concerned. Additionally, these returns have a negative relationship with the number of complaints per branch. El objetivo de este trabajo es analizar el impacto de las quejas a terceras partes sobre losresultados empresariales. Para ello, se proponen dos hipótesis de investigación, argumentadassiguiendo la literatura de insatisfacción, emociones, y economÃa. La metodologÃa se apoya en elevent study para estimar la variación de la rentabilidad de las acciones de las empresas generadaen la Bolsa por la publicación de la Memoria Anual del Servicio de Reclamaciones del Bancode España; asà como en el análisis de regresión para examinar el impacto del número de quejaspor oficina en dicha variación. La aplicación empÃrica se lleva a cabo para una muestra de oncebancos sobre los que se efectúan las quejas y que cotizan en la Bolsa de Madrid entre 1992 y2001. Los resultados obtenidos ponen de manifiesto un impacto negativo de la publicación dedichas memorias anuales de quejas sobre la rentabilidad de las acciones de los bancosimplicados, y que dicha rentabilidad mantiene una relación negativa con el volumen de quejaspor oficina.Quejas a terceras partes; Resultados empresariales; Banca Third-party complaints; Firm performance; Banking industry
Using Lucene for Developing a Question-Answering Agent in Portuguese
Given the limitations of available platforms for creating conversational agents, and that a question-answering agent suffices in many scenarios, we take advantage of the Information Retrieval library Lucene for developing such an agent for Portuguese. The solution described answers natural language questions based on an indexed list of FAQs. Its adaptation to different domains is a matter of changing the underlying list. Different configurations of this solution, mostly on the language analysis level, resulted in different search strategies, which were tested for answering questions about the economic activity in Portugal. In addition to comparing the different search strategies, we concluded that, towards better answers, it is fruitful to combine the results of different strategies with a voting method
the role of intercultural mediation
Migration is generally described as a process that is nationally specific and that have
features common to several countries. This has been shown by several authors through
comparative research that compares the migration process of the same immigrant group to
several countries (among others, Engbersen, Snel, & de Boom, 2010) or which scrutinises the
migration realities of different countries (Zimmermann, 2005). Most of these studies are about
geographically near countries, which are part of the same political system (the EU), and that
have an established (albeit differentiated) welfare system. These proximities (geographical, but
also political and social) allowed the authors of these studies to conceptualise the existence of
several migration models or regimes: the southern European model (Baldwin-Edwards, 2012),
the Iberian model of Migration (Malheiros, 2012); the intra-EU mobility regime (Engbersen
et al., 2017). These migratory regimes are intertwined by migrant integration models or by
different approaches to increasingly diverse populations. Although these are often identified
as ‘national models of integration’, they do not fail to integrate the developments that have
been recorded in the last decades in the international contexts in which the countries are
inserted. Throughout the present text, the Portuguese experience in dealing with immigrant
integration is used to reflect on the development of intercultural policies and practices, and
on the role of intercultural mediation.
The article is structured in the following way: in the introductory section we will review the
discussion on interculturalism; in a second section the Portuguese immigration context will
be presented; in a third section the integration of immigrants in the country will be analysed,
given special attention to the development of policies that support immigrants’ integration
process. In the fourth section, the role of intercultural mediation for the integration of
immigrants will be considered.info:eu-repo/semantics/publishedVersio
ASAPP 2.0: Advancing the state-of-the-art of semantic textual similarity for Portuguese
Semantic Textual Similarity (STS) aims at computing the proximity of meaning transmitted by two sentences. In 2016, the ASSIN shared task targeted STS in Portuguese and released training and test collections. This paper describes the development of ASAPP, a system that participated in ASSIN, but has been improved since then, and now achieves the best results in this task. ASAPP learns a STS function from a broad range of lexical, syntactic, semantic and distributional features. This paper describes the features used in the current version of ASAPP, and how they are exploited in a regression algorithm to achieve the best published results for ASSIN to date, in both European and Brazilian Portuguese
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