Explant Type, Culture System, 6-Benzyladenine, Meta-Topolin and Encapsulation Affect Indirect Somatic Embryogenesis and Regeneration in Carica papaya L.

A protocol to propagate papaya hybrid plants through indirect somatic embryogenesis was developed considering the effect of explant type, culture system, particular cytokinins and encapsulation, in different stages of the process. Optimal 2,4-dichlorophenoxyacetic acid (2,4-D) concentrations for non-embryogenic callus formation ranged between 9.0 and 27.1 μM in half-cut seeds, while higher concentrations were harmful. Non-embryogenic callus was also obtained with 22–158 μM 2,4-D from hypocotyl segments. Callus with embryogenic structures was only obtained in half-cut seeds cultured in the darkness on half-strength Murashige and Skoog culture medium supplemented with 2,4-D, while hypocotyl segments and isolated zygotic embryos failed to produce this type of callus regardless of the 2,4-D and sucrose (30 and 70 g l-1) concentrations tested in this study. Both, embryogenic callus development and quantity of somatic embryos formed per embryogenic callus, which ranged between 11 and 31 units after 14 months, required 2,4-D, but without any effect of the concentration. Histological studies confirmed the multicellular origin of the somatic embryos. In further steps, liquid medium induced over four times more somatic embryos than agar-gelled medium and showed significantly higher production of globular somatic embryos (85 vs. 57%). Both, 6-benzyladenine (BA) and meta-topolin (Mtop) stimulated sprouting (40–45%) of the somatic embryos (development of shoots only) in concentrations of up to 2.7 and 10 μM, respectively. Sprouting probability showed a 2nd order polynomial trend despite the range of concentration used for each cytokinin. This is the first report about the positive effect of Mtop on the apical shoot development of Carica papaya somatic embryos known to the authors. Radicle growth was observed in 5% or less of the cultivated embryos, regardless of the BA concentration. Finally, all encapsulation conditions tested (2.5, 3.5, and 4.5% sodium alginate, combined with 50 and 100 mM CaCl2) reduced sprouting of somatic embryos when compared to the non-encapsulated ones, whereas capsule hardness showed low correlation with embryo sprouting. Embryos were further cultivated until they became plantlets approximately 5 cm long. They were acclimatized and afterward planted in the field, where they flowered and produced fruit

Nonlinear self-collimated sound beams in sonic crystals

We report the propagation of high-intensity sound beams in a sonic crystal, under self-collimation or reduced-divergence conditions. The medium is a fluid with elastic quadratic nonlinearity, where the dominating nonlinear effect is harmonic generation. The conditions for the efficient generation of narrow, non-diverging beam of second harmonic are discussed. Numerical simulations are in agreement with the analytical predictions made, based on the linear dispersion characteristics in modulated media and the nonlinear interaction in a quadratic medium under phase matching conditions.Comment: Sent to PR

Ultradiscrete kinks with supersonic speed in a layered crystal with realistic potentials

We develop a dynamical model of the propagating nonlinear localized excitations, supersonic kinks, in the cation layer in a silicate mica crystal. We start from purely electrostatic Coulomb interaction and add the Ziegler-Biersack-Littmark short-range repulsive potential and the periodic potential produced by other atoms of the lattice. This approach allows the construction of supersonic kinks which can propagate in the lattice within a large range of energies and velocities. The interparticle distances in the lattice kinks with high energy are physically reasonable values. The introduction of the periodic lattice potential results in the important feature that the kinks propagate with a single velocity and a single energy which are independent on the excitation conditions. The found kinks are ultra-discrete and can be described with the "magic wave number" $q\simeq 2\pi/3a$, which was previously revealed in the nonlinear sinusoidal waves and supersonic kinks in the Fermi-Pasta-Ulam lattice. The extreme discreteness of the supersonic kinks, with basically two particles moving at the same time, allows the interpretation of their double-kink structure. The energy of the supersonic kinks is between the possible source of $^{40}$K recoil in beta decay and the energy necessary for the ejection of an atom at the border as has been found experimentally.Comment: 14 pages, 15 figure

NXP Semiconductors México

ITESO, A.C

Los expedientes judiciales como fuente para la reconstrucción de archivos familiares. El ejemplo del archivo del antiguo marquesado de Lanzarote

Los archivos familiares son una fuente de información de primer orden para el conocimiento del pasado. Sin embargo, muchas veces el traspaso de un título nobiliario de un linaje a otro, o la desatención por parte de sus propios titulares, ha provocado su desaparición. Tal es el caso del archivo del antiguo marquesado de Lanzarote, hoy en paradero desconocido y escasamente mencionado por la historiografía. Si bien la localización de un inventario de este, realizado en 1634, nos permite conocer qué había en ese momento en el ar-chivo y nos habilita para reconstruirlo, en la medida de lo posible, junto al recurso de otras fuentes documentales como los expedientes judiciales, en los que figuran numerosas copias, trasladadas de sus originales, que fueron presentados como pruebas en pesquisas y juicios. En este estudio lo que se muestra es el valor de los archivos y expedientes judiciales para la reconstrucción de los archivos familiares desaparecidos

Quantitative Analysis of differential phosphorylation in a PKC1 overexpression

Comunicaciones a congreso

Interacción de los antineoplásicos orales con los alimentos: revisión sistemática

[email protected]ón: Los estudios de biodisponibilidad son parte integrante del desarrollo clínico de medicamentos para administración oral con el fin de identificar potenciales interacciones fármaco-alimento (iFA). Actualmente, para los antineoplásicos orales se empieza a reconocer su importancia clínica, aun cuando lamentablemente, la información disponible presenta variabilidad en su evidencia científica. Objetivos: Revisar la evidencia científica disponible sobre las interacciones de los alimentos con medicamentos antineoplásicos orales y establecer recomendaciones para su administración. Métodos: Se realizó una búsqueda bibliográfica en Medline y The Cochrane Library para el periodo comprendido entre enero de 1966 a marzo de 2008, enfocada a identificar las publicaciones sobre interacciones fármaco alimento con antineoplásicos orales. El análisis bibliográfico consta de dos fases. En la primera fase se excluyeron los artículos que por título y contenido del resumen no se correspondían con el objetivo planteado; en la segunda fase se eliminaron las referencias duplicadas en ambas bases de datos. Los criterios de inclusión para seleccionar los artículos fueron: diseño (revisiones sistemáticas, metaanálisis, ensayos clínicos randomizados Fase I y II), población (pacientes adultos; >19 años de edad), intervención evaluada (administración de antineoplásicos orales bajo condiciones de ayuno o con alimentos) y medida del resultado de la iFA (cálculo del IC90% de la razón entre la media geométrica de valores del área bajo la curva de concentraciones plasmáticas (ABC) o la concentración plasmática máxima (Cmax) con y sin alimentos). Se excluyeron las publicaciones que como medida de resultado no hacían referencia al dictamen de bioequivalencia establecido por la Food and Drugs Administration (FDA). La valoración crítica de los artículos seleccionados se realizó según las recomendaciones que de acuerdo con la FDA deben cumplir estos estudios. Resultados: En la búsqueda inicial se obtuvieron 850 referencias (98,5% Medline + y 1,4% Cochrane). En la primera fase se excluyeron el 87,7% (746) de los artículos, correspondiendo el 100% a la búsqueda en Medline. En la segunda fase, quedaron 40 artículos (5,2% de los iniciales) para su lectura crítica a texto completo, a los que se añadieron cuatro más no indexados en Medline. De la lectura crítica de los 44 artículos finales, se excluyeron 25 artículos (20 artículos originales, 4 comunicaciones cortas y 1 metanálisis) por no incluir como medida de resultado el dictamen de bioequivalencia. Los 19 (2,2%) artículos restantes proporcionaron información sobre 19 fármacos antineoplásicos orales, en 210 pacientes y 146 voluntarios sanos. De estos 19 fármacos, el 63% no presentan iFA o interacciones fármaco-alimento, pudiéndose administrar indistintamente con/sin alimentos; el 21% se deben administrar con alimentos y sólo el 16% presentan interacción fármaco alimento, por lo que se deben administrar sin alimentos. Discusión: Actualmente, la importancia clínica de las interacciones fármaco alimento con antineoplásicos orales se identifica más directamente con la seguridad del paciente que con la efectividad del tratamiento. Ante el desarrollo de estos agentes orales, su irrupción en la terapia oncológica desplazando a la terapia parenteral, con costes mensuales de miles de euros, hay necesidad de realizar estudios farmacocinéticos y farmacodinámicos bien diseñados. Su objetivo debe de ser comparar su biodisponibilidad en presencia o ausencia de alimentos con la respuesta clínica. Mientras tanto, establecer recomendaciones para su administración en relación con los alimentos, es inconsistente para algunos de estos fármacos y su resultado incierto por la falta de estudios fundamentados en el dictamen de bioequivalencia establecido por la FDA.Introduction: studies on bioavailability are part of the clinical development of drugs for oral use in order to identify potential drug-food interactions. For oral antitumor drugs, their clinical importance is currently recognized although regrettably the information available presents variability concerning the scientific evidence. Objectives: To review the available scientific evidence about oral anti-tumor medications and establish the recommendations for their administration with foods. Methods: We carried out a bibliographic search in Medline and The Cochrane Library for the period January of 1966 to March of 2008, focused on identifying those publications about drug-food interactions with oral antitumor medications. The bibliographical analysis was made in two steps. During the first phase, we excluded those articles in which the title or their content did not correspond with the objective settled; during the second phase, we deleted all the references duplicated in both databases. The inclusion criteria to select the articles were: design (systematic reviews, meta-analysis, Phase I and Phase II randomized clinical trials), population (adult patients; >19 years of age), intervention evaluated (administration of oral anti-tumor drugs under fasting conditions or with food) and measurement of the iFA results (calculation of the 90% CI of the odds ratio between the geometric mean of the values under the curve of the plasma concentrations (ABC) or the maximal plasma concentration (Cmax) with and without foods). We excluded those publications that did not make reference to the bioequivalence dictamen established by the Food and Drugs Administration (FDA) in their outcomes measurement. A critical appraisal of the selected articles was done according to the recommendations that the FDA established to be met by these studies. Results: At the initial search we obtained 850 references (98.5% Medline + and 1.4% Cochrane). During the first phase, we excluded 87.7% (746) of the articles, 100% of them corresponding to the search in Medline. During the second phase, 40 studies remained (5.2% of the initial ones) for full-text critical appraisal, to which four studies were added not indexed in Medline. From the critical appraisal of the 44 final articles, 25 were excluded (20 original articles, 4 short communications, and 1 meta-analysis) because they did not include as an outcome measure the bioequivalence dictamen. The 19 (2.2%) remaining articles provided information on 19 oral anti-tumor drugs in 210 patients and 146 healthy volunteers. Of these 19 drugs, 63% did not present drugfood interactions, with the possibility of administering them either with or without food; 21% have to be administered with foods and only 16% present drug-food interactions, so they have to be administered without foods. Discussion: Currently, the clinical importance of drugfood interactions with oral anti-tumor drugs is identified more directly with the patient's safety than with the efficacy of the therapy. Given the development of these oral agents, their incorporation into the oncologic strategy displacing parenteral therapy, with monthly costs of thousands of Euros, it is necessary to perform well-designed studies on pharmacokinetics and pharmacodynamics. Their goal has to be comparing their bioavailability in the presence or absence of foods with the clinical response. In the meanwhile, to establish recommendations for their administration in relation to foods is inconsistent for some of these drugs and their results is uncertain given the lack of studies based on the FDAbioequivalence dictamen

Nonlinear waves in a chain of magnetically coupled pendula

A motivation for the study of reduced models like one-dimensional systems in Solid State Physics is the complexity of the full problem. In recent years our group has studied theoretically, numerically and experimentally wave propagation in lattices of nonlinearly coupled oscillators. Here, we present the dynamics of magnetically coupled pendula lattices. These macroscopic systems can model the dynamical processes of matter or layered systems. We report the results obtained for harmonic wave propagation in these media, and the different regimes of mode conversion into higher harmonics strongly influenced by dispersion and discreteness, including the phenomenon of acoustic dilatation of the chain, as well as some results on the propagation of localized waves i.e., solitons and kinks.Generalitat Valenciana APOSTD/2017/042Umiversitat Politècnica de València PAID-01-14Ministerio de Economía y Competitividad (MINECO), Spain FIS2015-65998-C2-2-PJunta de Andalucía 2017/FQM-28

Floración in vitro – revisión de literatura

In vitro flowering can be induced at different stages during development of in vitro plants by changes in chemical and physical factors related to the tissue culture process. Among the physical factors, photoperiod and temperature have been studied more detailed. Their inductive effect may vary in different species. Some physical factors can also be replaced by chemical stimuli. The chemical factors more frequently described in the literature are some growth regulators and the sucrose/nitrogen ratio. Cytokinins may induce flower development from various organs, but high concentrations can inhibit flowering and cause sprouting of vegetative buds. Gibberellins and polyamines (mostly spermidine) have a positive effect on flower induction. While, ethylene and auxin seem to be powerful inhibitors of in vitro flowering. However, auxins seem to be necessary during the early stages of floral development. An increase in the concentration of sucrose in the culture medium favor development of flowers in vitro, whereas a high concentration of nitrogen can stimulate vegetative growth of explants. Nevertheless, if the nitrogen concentration is too low, explants do not develop well. The aim of this literature review is to discuss most common factors related to in vitro flowering and to list the most relevant scientific literature about the subject from 1980 on.Key words: flower induction, growth regulators, inducers, tissue cultureAbreviaturas: 2,4-D Ácido 2,4-diclorofenoxiacético, 2iP 2–isopentiladenina, ABA Ácido abscísico, AC Agua de coco, AG3 Ácido giberélico, AIA Ácido indol acético, AIB Ácido indol butírico, ANA Ácido naftalen acético, BAP Benciladenina, CAct Carbón activado, CasHid Caseína hidrolizada, DSDPs Plantas de día corto desplazado, GAx Giberelina x, LDPs Plantas de día largo, MES Ácido 2 (N-morfolino) etanosulfónico, MS Murashige y Skoog (1962), MT Murashige y Tucker (1969), PSF Plantas sensibles al fotoperíodo, Put Putrescina, PVP Polivinilpirrolindona, SAM S-adenosil-L-metionina, SAMDC S-adenosil-L-metionina descarboxilasa, SDPs Plantas de día corto, Spd Espermidina, Spm Espermina, TDZ TidiazuronLa floración in vitro puede ser inducida en diferentes estadios durante el desarrollo de las plantas in vitro mediante variaciones en los factores físicos y químicos relacionados con el cultivo de tejidos. Dentro de los factores físicos, el fotoperíodo y la temperatura son los que se han estudiado con más detalle. Su efecto inductivo puede variar en diferentes especies. Algunos factores físicos también pueden ser sustituidos por estímulos químicos. Los factores químicos que han sido descritos con más frecuencia en la literatura son algunos reguladores de crecimiento y la relación sacarosa/nitrógeno. Las citoquininas pueden inducir el desarrollo floral a partir de varios órganos; no obstante, altas concentraciones pueden inhibir la floración y ocasionar brotación de yemas vegetativas. Las giberelinas y las poliaminas (principalmente espermidina) presentan un efecto positivo en la inducción floral. De forma contrastante, el etileno y las auxinas han mostrado ser poderosos inhibidores de la floración in vitro. Sin embargo, las auxinas parecen ser necesarias durante los primeros estadios del desarrollo floral. Un aumento en la concentración de sacarosa en el medio de cultivo puede favorecer el desarrollo de flores in vitro; mientras que concentraciones altas de nitrógeno pueden estimular el desarrollo vegetativo de los explantes. No obstante, si las concentraciones de nitrógeno son muy bajas, el explante no se desarrolla bien. La presente revisión de literatura tiene como fin discutir los factores más comunes que participan en la inducción de la floración in vitro, así como presentar la literatura científica más relevante en el tema a partir de 1980.Palabras clave: cultivo de tejidos, inducción floral, inductores, reguladores de crecimient