Search results for "Centro"
showing 10 items of 643 documents
γ-Tubulin in Barley and Tobacco: Sequence Relationship and RNA Expression Patterns in Developing Leaves during Mitosis and Post-Mitotic Growth
2002
gamma-Tubulin is typically associated with microtubule organising centres, such as the centrosome, and appears to mediate microtubule nucleation. Centrosomes are usually not found in higher plants, but active genes homologous to gamma-tubulin have been identified in the plant kingdom, including the angiosperms Arabidopsis, maize and rice. We have isolated and characterised gamma-tubulin cDNA sequences of two further angiosperm species, barley and tobacco. Sequence comparison revealed a phylogenetic tree with distinct clusters corresponding to the systematic position of the species. Furthermore, domains, thought to be exposed in the folded protein and to be candidates for interaction with as…
Sequence and analysis of chromosome 3 of the plant Arabidopsis thaliana.
2000
Arabidopsis thaliana is an important model system for plant biologists. In 1996 an international collaboration (the Arabidopsis Genome Initiative) was formed to sequence the whole genome of Arabidopsis and in 1999 the sequence of the first two chromosomes was reported. The sequence of the last three chromosomes and an analysis of the whole genome are reported in this issue. Here we present the sequence of chromosome 3, organized into four sequence segments (contigs). The two largest (13.5 and 9.2 Mb) correspond to the top (long) and the bottom (short) arms of chromosome 3, and the two small contigs are located in the genetically defined centromere. This chromosome encodes 5,220 of the rough…
Chromosomal localization and molecular characterization of three different 5S ribosomal DNA clusters in the sea urchin Paracentrotus lividus
2007
In this paper the chromosomal localization and molecular cloning and characterization of three 5S rDNA clusters of 700 bp (base pairs), 900 bp, and 950 bp in the sea urchin Paracentrotus lividus are reported. Southern blot hybridization demonstrated the existence of three 5S rDNA repeats of differing length in the P. lividus genome. Fluorescence in situ hybridization analysis, performed in parallel on both haploid and diploid metaphases and interphase nuclei using different 5S rDNA units as probes, localized these 5S rDNA clusters in 3 different pairs of P. lividus chromosomes. This is the first complete gene mapping not only in a sea urchin but also in the phylum of echinoderms as a whole…
Enseñanza de las ciencias : revista de investigación y experiencias didácticas
2016
Presentamos los resultados de una investigación enfocada a mejorar el aprendizaje de la geometría y la adquisición de destrezas de razonamiento matemático de estudiantes de 2.º año medio de centros de enseñanza secundaria vulnerables de Chile. Se ha diseñado un experimento de enseñanza, con grupos experimental y control, basado en una unidad de enseñanza, diseñada de acuerdo con los niveles y las fases de Van Hiele, y en un pretest y un postest, para evaluar el cambio en el nivel de razonamiento de los estudiantes derivado de la intervención. Los resultados muestran una diferencia significativa, a favor del grupo experimental, en el desarrollo del nivel de razonamiento de los estudiantes. P…
Las bases para un sistema uniforme de Derecho Internacional Privado en Centroamérica para las acciones de grupo por daño ambiental transfronterizo
2017
Este trabajo aborda al daño ambiental que suele ir de la mano con el desarrollo industrial impulsado por los procesos de integración comercial y económica. Se enfoca en los efectos dañosos que las lesiones ambientales pueden tener en el patrimonio y la persona de los particulares, reflexionando a profundidad en sus características, y en la forma en la que el Derecho puede aportar a su solución, y a su prevención. En función de lo anterior, uno de los propósitos de este trabajo ha sido entender cuál es el estado de evolución del Derecho civil en la región centroamericana, para determinar si las soluciones que éste ofrece para los problemas que se identifican en este trabajo, son las más adec…
Echinoderm Antimicrobial Peptides
2016
Abstract Antimicrobial peptides (AMPs) are widely expressed in organisms and have been linked to innate and acquired immunity in vertebrates. These compounds are constitutively expressed from different cellular types to interact directly with infectious agents and/or modulate immunoreactions. In invertebrates, including echinoderms, which lack a vertebrate-type adaptive immune system, AMPs represent the major humoral defense system against infection, showing a diverse spectrum of action mechanisms, most of them related to plasma membrane disturbance and lethal alteration of microbial integrity. Here, we summarize the knowledge of AMPs in echinoderms as Strongylocins identified in the sea ur…
A Vector Approach to Euler's Line of a Triangle
1992
Among the many interesting properties that triangles possess there is one that quickly attracts our curiosity and stays easily in our mind: The centroid, circumcentre and orthocentre all lie in a common line (Euler's Line). An elementary simple proof can be obtained using metric and affine properties of the points involved, [1]. Our aim here is to illustrate a proof using vectors. We identify points in the plane with their position vectors. It is easy to see that the centroid G of the triangle ABC is given by the identity
Cultural and socio-economic impacts of Mediterranean marine protected areas
2000
Marine protected areas (MPAs) may be important for protecting the marine environment, but they may also have substantial socio-cultural impacts about which very little is currently known, or acknowledged. In the Mediterranean, few data are available on the socio-economic consequences of MPAs. The present study reviews the existing data on MPAs in Spain, France, Italy and Greece. A general increase in tourist activities in Mediterranean MPAs is evident, as are increases in the abundances of larger fish species, although there are no data indicating yields for fisheries increase adjacent to MPAs. A large increase in the number of divers and vessels using MPAs has already had impacts on natura…
Non-Contact Measurement of River Surface Velocity and Discharge Estimation with a Low-Cost Doppler Radar Sensor
2020
River discharge is an important variable to measure in order to predict droughts and flood occurrences. Once the cross-sectional geometry of the river is known, discharge can be inferred from water level and surface flow velocity measurements. Since river discharges are of particular interest during extreme weather events, when river sites cannot be safely accessed, noncontact sensing technologies are particularly appealing. To this purpose, this work proposes a prototype of a low-cost continuous wave (CW) Doppler radar sensor, which is able to monitor the surface flow velocity of rivers. The prototype is tested at two gauged sites in central Italy, along the Tiber River. The surface flow v…
Ephesian Imports in Cadiz: New Finds from Punta del Nao (La Caleta)
2017
Recientes prospecciones subacuáticas, llevadas a cabo en la zona de La Caleta de Cádiz entre 2008 y 2010, han sacado a la luz interesantes materiales relacionados con las distintas fases de la historia de la Bahía de Cádiz. Dentro del estudio general de dichos materiales, este artículo presenta unas pequeñas ánforas producidas en el hinterland de Éfeso, que constituyen las primeras nuestras conocidas hasta ahora de este tipo de importaciones en la ciudad de Cádiz. Dichas ánforas pueden considerarse un indicio representativo del comercio de larga distancia y del consumo de productos de alta gama por parte de las élites gaditanas durante el periodo imperial romano y la tardía Antigüedad. En r…