Thermodynamics and dynamics of the formation of spherical lipidic vesicles

We propose a free energy expression accounting for the formation of spherical vesicles from planar lipidic membranes and derive a Fokker-Planck equation for the probability distribution describing the dynamics of vesicle formation. We found that formation may occur as an activated process for small membranes and as a transport process for sufficiently large membranes. We give explicit expressions for the transition rates and the characteristic time of vesicle formation in terms of the relevant physical parameters.Comment: 14pgs, 6 figures, sendo to Jour. Phys. Bio

Multiple Effects of Cadmium on the Photosynthetic Apparatus of Avicennia germinans L. as Probed by OJIP Chlorophyll Fluorescence Measurements

The toxic effects of cadmium on the photosynthetic apparatus of Avicennia germinans were evaluated by means of the chlorophyll fluorescence transient OÐJÐIÐP. The chlorophyll fluorescence transients were recorded in vivo with high time resolution and analyzed according to the OJIP-test that can quantify the performance of photosystem II. Cadmium-treated plants showed a decrease in yield for primary photochemistry, TR 0 /ABS. The performance index of photosystem II (PSII), PI ABS , decreased due to cadmium treatment. This performance index is the combination of the indexes of three independent parameters: (1) total number of active reaction centers per absorption (RC/ABS), (2) yield of primary photochemistry (TR 0 /ABS), and (3) efficiency with which a trapped exciton can move an electron into the electron transport chain (ET 0 /TR 0 ). Additionally, the F 0 /F v registered the highest sensitivity to the metal, thus indicating that the water-splitting apparatus of the oxidizing side of PSII is the primary site of action of cadmium. In summary, cadmium affects several targets of photosystem II. More specifically the main targets of cadmium, according to the OJIPtest, can be listed as a decrease in the number of active reaction centers and damage to the activity of the water-splitting complex

Establishment and characterisation of a new cell line derived from Culex quinquefasciatus (Diptera: Culicidae)

Insect cell cultures are an important biotechnological tool for basic and applied studies. The objective of this work was to establish and characterise a new cell line from Culex quinquefasciatus embryonic tissues. Embryonated eggs were taken as a source of tissue to make explants that were seeded in L-15, Grace's, Grace's/L-15, MM/VP12, Schneider's and DMEM culture media with a pH range from 6.7-6.9 and incubated at 28ºC. The morphological, cytogenetic, biochemical and molecular characteristics of the cell cultures were examined by observing the cell shapes, obtaining the karyotypes, using a cellulose-acetate electrophoretic system and performing random amplified polymorphic DNA-polymerase chain reaction analysis, respectively. The Grace's/L-15 medium provided the optimal nutritional conditions for cell adhesion and proliferation. Approximately 40-60 days following the explant procedure, a confluent monolayer was formed. Cellular morphology in the primary cultures and the subcultures was heterogeneous, but in the monolayer the epithelioid morphology type predominated. A karyotype with a diploid number of six chromosomes (2n = 6) was observed. Isoenzymatic and molecular patterns of the mosquito cell cultures matched those obtained from the immature and adult forms of the same species. Eighteen subcultures were generated. These cell cultures potentially constitute a useful tool for use in biomedical applications

El Caribe: Origen del mundo moderno

[EN] This book is a result of the European project titled Connected Worlds: The Caribbean, Origin of the Modern World. This project is directed by Consuelo Naranjo-Orovio from Institute of History (CSIC). The book is presented so that the educational community has the latest and necessary scientific knowledge, in a clear and accessible way, for its transmission to new generations, and contributes -through education and historical knowledge- to combat the discrimination against non-white populations in Europe, the Caribbean and Latin America. Through studies we try to promote, rescue and protect our historical memory and cultural expressions of different peoples, as well as enhance dialogue, debate and international cooperation.With this volume we want to contribute, in short, to the knowledge of the past and present of Caribbean countries and their connection with the rest of Latin America, Europe and Africa. The various themes emphasize topical issues that cannot be missing in the higher education of our societies, whose classrooms, a true reflection of society, are marked by integration, multiculturalism and coexistence between different cultures. Education therefore must contribute to the integration of human diversity and the banishment of concepts of one upmanship between populations, based on the misconception regarding the existence of races in the human species.In this book, teachers and students will find multimedia resources that expand the gathered information and various interviews with Caribbean history specialists, designed and conducted by Consuelo Naranjo Orovio and edited by Luis Centurión, from Ediciones Doce Calles publishing house team, who is also a project member: http://youtube.com/c/ConnecCaribbeanProyecto[ES] Este libro es el resultado del proyecto europeo titulado Connected Worlds: The Caribbean, Origin of the Modern World. Este proyecto está dirigido por Consuelo Naranjo-Orovio del Instituto de Historia (CSIC). El libro se presenta para que la comunidad educativa tenga el conocimiento científico más reciente y necesario, de manera clara y accesible, para su transmisión a las nuevas generaciones, y contribuye, a través de la educación y el conocimiento histórico, a combatir la discriminación contra las poblaciones no blancas en Europa, el Caribe y América Latina. A través de los estudios tratamos de promover, rescatar y proteger nuestra memoria histórica y expresiones culturales de diferentes pueblos, así como mejorar el diálogo, el debate y la cooperación internacional. Con este volumen queremos contribuir, en resumen, al conocimiento del pasado y el presente de los países del Caribe y su conexión con el resto de América Latina, Europa y África. Los diversos temas enfatizan temas de actualidad que no pueden faltar en la educación superior de nuestras sociedades, cuyas aulas, un verdadero reflejo de la sociedad, están marcadas por la integración, el multiculturalismo y la convivencia entre diferentes culturas. La educación, por lo tanto, debe contribuir a la integración de la diversidad humana y al destierro de los conceptos de un solo dominio entre las poblaciones, basado en el concepto erróneo sobre la existencia de razas en la especie humana. En este libro, maestros y estudiantes encontrarán recursos multimedia que amplían la información recopilada y varias entrevistas con especialistas en historia del Caribe, diseñadas y dirigidas por Consuelo Naranjo Orovio y editadas por Luis Centurión, del equipo de la editorial Ediciones Doce Calles, que también es miembro del proyecto: http://youtube.com/c/ConnecCaribbeanProyectoPeer reviewe