Search results for "G1"

A Unified Approach to Portfolio Optimization with Linear Transaction Costs

2004

In this paper we study the continuous time optimal portfolio selection problem for an investor with a finite horizon who maximizes expected utility of terminal wealth and faces transaction costs in the capital market. It is well known that, depending on a particular structure of transaction costs, such a problem is formulated and solved within either stochastic singular control or stochastic impulse control framework. In this paper we propose a unified framework, which generalizes the contemporary approaches and is capable to deal with any problem where transaction costs are a linear/piecewise-linear function of the volume of trade. We also discuss some methods for solving numerically the p…

Interacción de procesos geomórficos y distribución de componentes de la superficie del suelo en relación a la evolución de los abarrancamientos de Ta…

2009

Este artículo se ha desarrollado en el contexto de los proyectos: REN2003-045707GLO(PECOS); CGL2007-63258/BOS(PREVEA) y CGL2006-11619(PROBASE), financiados por la CICYT en el marco del Plan Nacional I+D+I

Māris un Māra uz Marsu

2020

Grāmatas autors - emigrācijā, ASV dzīvojošs latvietis. Grāmatu sarakstījis 1977. gadā, kad viņa bērni vēl bija mazi, un tā ir veltīta viņiem, kas ir arī grāmatas galvenie varoņi. Grāmata tātad pieskaitāma zinātniski fantastiskajai literatūrai, un arī bērnu literatūrai. Grāmatas autors ir darbojies pie daudziem ļoti specifiskiem projektiem ASV, pildot ievērojamu kompāniju pasūtījumus, kur saskāries ar futoroloģijas jautājumiem. To mēs redzam arī viņa grāmatas izklāstā, kur reizē ar fantastiskiem rosinājumiem par iespējamo dzīvi uz Marsa ir arī interesantas tehnokrātiskas idejas. Tur ir gan fantāzija, gan arī dziļas tehniskas zināšanas, kas gūtas minēto projektu risinājumu gaitā. Grāmata būs …

Vγ9 / Vδ2 T lymphocytes reduce the viability of intracellularMycobacterium tuberculosis

2000

An effective immune response against the intracellular pathogen Mycobacterium tuberculosis is strictly dependent on T cell activation. Although this protective response mainly depends on local release of pro-inflammatory cytokines by Th1 CD4(+) T cells, contribution of Vgamma9 / Vdelta2 T lymphocytes to immune protection against this pathogen is suggested by the antimycobacterial reactivity of this subset and its ability to produce large amounts of Th1 cytokines. Here we show that Vgamma9 / Vdelta2 T lymphocytes kill macrophages harboring live M. tuberculosis. The cytotoxic activity of Vgamma9 / Vdelta2 T lymphocytes was not MHC class I or class II restricted but was blocked by anti-TCR mon…

Interleukin 1 stimulates T lymphocytes to produce granulocyte-monocyte colony-stimulating factor.

1988

T lymphocytes are thought to cooperatively interact with monocytes to produce colony-stimulating factors (CSF). However, little is known about monocyte-mediated signals leading to CSF-secretion by T lymphocytes, although soluble monocyte products have been implicated. We have employed monoclonal antibody anti-T3B covalently coupled to CnBr-activated Sepharose 4B beads, to show that multimeric ligation of T cell antigen receptor leads to T cell receptiveness to interleukin 1 (IL-1), as indicated by T cell production of CSF, which induces growth of myeloid progenitor cells into neutrophil, eosinophil, and monocyte colonies. To investigate the molecular basis of these findings, total RNA was e…

A produção de documentários como recurso didático TIC para o ensino de geografia e história: metodologia e proposta de trabalho

2015

Nos últimos anos estamos assistindo a uma mudança de paradigma educativo. A inclusão de novas tecnologias nas aulas está transformando as formas de ensinar e transmitir conhecimentos, assim como o modo em que os alunos utilizam os conteúdos e os aplicam em sua vida diária. É fundamental, portanto, dotar essas novas Tecnologias da Informação e Comunicação (TIC´s) de um papel concreto na educação com propostas de inserção em atividades para trabalhar, por exemplo, nas ciências sociais. O presente artigo, fruto de práticas realizadas nas aulas em contextos escolares e universitários no Brasil e na Espanha, pretende apresentar os resultados da utilização da produção de documentários no ensino d…

Estudio de las fluctuaciones del nivel del agua en la laguna de Gallocanta (Aragón, España) mediante imágenes satelitales de Sentinel-2

2021

[EN] This study has been monitored for five years by Sentinel-2 satellite images, at different seasons of the year, of the fluctuations in the water level of the Gallocanta Lake (between the provinces of Teruel and Zaragoza, Spain) considered a hypersaline and endorheic wetland, which has characteristics that make it unique in the geographical area in which it is located, as well as for the operation of the system. Rainfall in the area has a wide variation giving the maximums in the moths of May and June and the minimums in January and February, with considerable fluctuations in the water level from the almost total drying of the lagoon to the filling with a depth of approximately 3 meters.

Análisis de métodos de validación cruzada para la obtención robusta de parámetros biofísicos

2015

[EN] Non-parametric regression methods are powerful statistical methods to retrieve biophysical parameters from remote sensing measurements. However, their performance can be affected by what has been presented during the training phase. To ensure robust retrievals, various cross-validation sub-sampling methods are often used, which allow to evaluate the model with subsets of the field dataset. Here, two types of cross-validation techniques were analyzed in the development of non-parametric regression models: hold-out and k-fold. Selected non-parametric linear regression methods were least squares Linear Regression (LR) and Partial Least Squares Regression (PLSR), and nonlinear methods were…

Synthesis and antiproliferative activities of two new analogs of tetrazepinones

Based on the encouraging results, we report the multistep synthesis and the biologicalo results of two new analogs of tetrazepinones: the 3,5-dimethyl-6-phenyl-8-(trifluoromethyl-5,6-dihydropyrazo1o[3-4-f]1,2,35)tetrazepin-4(3H)-one and the 3-(2-chloroethyl)-5-methyl-6-phenyl-8-(trifluoromethyl-5,6-dihydropyrazo1o[3-4-f]1,2,35)tetrazepin-4(3H)-one. Both compounds showed a pro-apoptotic activity against HL60 and K562 resistant cell lines. Flow cytometry studies carried out 0n K562 cells allowed to establish that the methyl derivative induces G0-G1, phase arrest followed by apoptosis, whereas the chloroethyl derivative is a not phase-specific agent.

Nickel induces intracellular calcium mobilization and pathophysiological responses in human cultured airway epithelial cells.

2009

Abstract Environmental exposure to nickel is associated to respiratory disorders and potential toxicity in the lung but molecular mechanisms remain incompletely explored. The extracellular Ca 2+ -sensing receptor (CaSR) is widely distributed and may be activated by divalent cations. In this study, we investigated the presence of CaSR in human cultured airway epithelial cells and its activation by nickel. Nickel transiently increased intracellular calcium (−log EC 50  = 4.67 ± 0.06) in A549 and human bronchial epithelial cells as measured by epifluorescence microscopy. Nickel (20 μM)-induced calcium responses were reduced after thapsigargin or ryanodine exposure but not by Ca 2+ -free medium…