Efecto de los cotiledones y el uso de semilla híbrida en brócoli (Brassica oleracea var. italica L.)

p.177-187Los objetivos de este ensayo fueron (a) cuantificar la acumulación de biomasa en función de la eliminación parcial o total de los cotiledones tempranamente durante la fase de propagación en una bandeja multicelda y (b) evaluar el efecto sobre dos materiales genéticos (variedad de polinización abierta o híbridos F1) durante el ciclo primaveral - estival en el cinturón hortícola de la ciudad de Mar del Plata. Los resultados indican que la falta total o parcial de cotiledones funcionales durante la expansión de las primeras hojas verdaderas de la planta puede afectar la generación de biomasa fotosintética luego del trasplante. Las diferencias a favor del uso de híbridos F1 se amplificaron bajo condiciones de temperatura supraópticas

Gravitational decoherence: A general nonrelativistic model

We derive a general quantum master equation for the dynamics of a scalar bosonic particle interacting with a weak, stochastic and classical external gravitational field. The dynamics predicts decoherence in position, momentum and energy. We show how our master equation reproduces the results present in the literature by taking appropriate limits, thus explaining the apparent contradiction in their dynamical description. Our result is relevant in light of the increasing interest in the low energy quantum-gravity regime

Gravitational Decoherence and the Possibility of Its Interferometric Detection

We present a general master equation describing the quantum dynamics of a scalar bosonic field interacting with an external weak and stochastic gravitational field. The dynamics predicts decoherence both in position and in energy momentum. We show how the master equation reproduces, thus generalizing, the previous results in the literature by taking appropriate limits. We estimate the effect of gravitational decoherence in atom interferometers, providing also a straightforward way to assess the magnitude of the effect

“Estudio del compromiso organizacional en los trabajadores de una fundación en Chile”

Santiago Luis Saenz Asprea [Parte I], Ana Lissette Carranza Monroy [Parte II]Teniendo en consideración los desafíos que plantea la globalización y la competitividad actual a la que se enfrenta una organización sin fines de lucro, resulta fundamental trabajar en potenciar su capital humano y el compromiso de este con la organización. En el estudio presentado, se realizó un diagnóstico utilizando una metodología de recolección de información mixta, para identificar desde la perspectiva de los colaboradores, aspectos que afectan el compromiso organizacional con la fundación. Factores como agotamiento emocional, desequilibrio entre demandas y recursos disponibles, falta de posibilidades de desarrollo y complicaciones en la priorización de metas, afectan de manera negativa las dimensiones de compromiso normativo, de continuidad y con las metas. De la misma forma, la identificación de un ambiente agradable, buenas relaciones laborales, contar con una causa como motor de trabajo y la percepción de valores compartidos, influyen de forma positiva en el compromiso organizacional de los colaboradores en la dimensión afectiva. Teniendo en consideración estos aspectos, se desarrolló un plan de intervención para potenciar el compromiso organizacional de los colaboradores con la fundación.Versión original del auto

Plants Extracts Loaded in Nanocarriers: An Emergent Formulating Approach:

Over the millennia, plants have represented for Humankind the main source of food, but also a vast resource to maintain health, for prophylactic properties or to cure human and animal diseases. Presently, between 65 and 80% of populations in developing countries use medicinal plants as therapeutic remedies for their primary healthcare and in Europe and USA there is an increasing demand of botanical products both on the form of food supplements and herbal medicinal products. Botanicals on the market are mainly based on traditional (infusions or decoctions), conventional (using organic solvents) and innovative (supercritical CO2 or subcritical water) extracts but there is an increasing demand of essential oils for aromatherapy. Conversely, the clinical use of many extracts is limited due to the need of repeated administrations or high doses because of low hydrophilicity and intrinsic dissolution rate(s), or physical/ chemical instability. Other limits are low absorption, poor pharmacokinetics and bioavailability, scarce biodistribution, first pass metabolism, trivial penetration and accumulation in the organs of the body. In the case of essential oils, the high volatility and instability are further limitations. Nowadays, the design and production of appropriate drug delivery systems, in particular nanosized ones (between 50 and 300 nm), have already entered into clinical use and can offer an advanced approach to optimized the therapeutic efficacy of extracts and essential oils. A successful drug carrier system should have optimal drug loading and release properties, a long shelf life, and exert a much higher therapeutic efficacy as well as lower side effects. Polymeric nanoparticles and lipid based-nanocarriers including micelles, vesicles, nanocochleates, micro- and nanoemulsions represent successful examples of extract nanoformulations overcoming these limitations. This review reports on some paradigmatic success stories of extract and EO nanoformulations with remarkable advantages over conventional formulations, which include increase of solubility, stability, permeation and bioavailability, sustained delivery. Paradigmatic examples include formulations of extracts from Vitex agnus-castus, Sylibum marianum, Phyllanthus amarus, Ginkgo biloba, Panax notoginseng, Hypericum perforatum and thyme essential oil

Ecological role of vertebrate scavengers in urban ecosystems in the UK

This is the final version of the article. Available from Wiley via the DOI in this record.Recent research has demonstrated how scavenging, the act of consuming dead animals, plays a key role in ecosystem structure, functioning, and stability. A growing number of studies suggest that vertebrate scavengers also provide key ecosystem services, the benefits humans gain from the natural world, particularly in the removal of carcasses from the environment. An increasing proportion of the human population is now residing in cities and towns, many of which, despite being highly altered environments, contain significant wildlife populations, and so animal carcasses. Indeed, non-predation fatalities may be higher within urban than natural environments. Despite this, the fate of carcasses in urban environments and the role vertebrate scavengers play in their removal have not been determined. In this study, we quantify the role of vertebrate scavengers in urban environments in three towns in the UK. Using experimentally deployed rat carcasses and rapid fire motion-triggered cameras, we determined which species were scavenging and how removal of carcass biomass was partitioned between them. Of the 63 experimental carcasses deployed, vertebrate scavenger activity was detected at 67%. There was a significantly greater depletion in carcass biomass in the presence (mean loss of 194 g) than absence (mean loss of 14 g) of scavengers. Scavenger activity was restricted to three species, Carrion crows Corvus corone, Eurasian magpies Pica pica, and European red foxes Vulpes vulpes. From behavioral analysis, we estimated that a maximum of 73% of the carcass biomass was removed by vertebrate scavengers. Despite having low species richness, the urban scavenger community in our urban study system removed a similar proportion of carcasses to those reported in more pristine environments. Vertebrate scavengers are providing a key urban ecosystem service in terms of carcass removal. This service is, however, often overlooked, and the species that provide it are among some of the most disliked and persecuted.Scientific and Technological Research Council of Turkey (Grant/Award Number: “Post-doctoral fellowship”) Natural Environment Research Council (Grant/Award Number: “NE/J015237/1”)

Pharmacokinetic analysis of topotecan after superselective ophthalmic artery infusion and periocular administration in a porcine mode

Purpose: To characterize the vitreous and plasma pharmacokinetics of topotecan after ophthalmic artery infusion (OAI) subsequent to superselective artery catheterization and to compare it with periocular injection (POI). Methods: The ophthalmic artery of 4 pigs was catheterized and 1 mg of topotecan infused over a period of 30 minutes. The contralateral eye was subsequently used for administering topotecan by POI. Serial vitreous specimens were obtained by microdialysis and plasma samples collected and assayed for total and lactone topotecan. Results: Maximum total topotecan concentration in the vitreous (median, range) was significantly higher after OAI compared with POI (131.8 ng/mL [112.9–138.7] vs. 13.6 ng/mL [5.5–15.3], respectively; P , 0.005). Median vitreous exposure calculated as area under the curve for total topotecan attained after OAI was significantly higher than after POI (299.8 nghour/mL [247.6–347.2] and 48.9 nghour/mL [11.8–63.4], respectively; P , 0.05). The vitreous to plasma exposure ratio was 29 after OAI and 3.4 after POI. Systemic exposure for total topotecan was low after both modalities of administration, with a trend to be lower after OAI compared with POI (10.6 nghour/mL [6.8–13.4] vs. 18.7 nghour/mL [6.3–21.7]; P = 0.54). Conclusion: Superselective OAI resulted in significantly higher vitreous concentrations and exposure and a trend toward lower systemic exposure than POI.Fil: Schaiquevich, Paula Susana. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buitrago, Emiliano. Universidad de Buenos Aires; ArgentinaFil: Ceciliano, Alejandro. No especifíca;Fil: Fandino, Adriana C.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Asprea, Marcelo. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sierre, Sergio. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Abramson, David H.. No especifíca;Fil: Bramuglia, Guillermo Federico. Universidad de Buenos Aires; ArgentinaFil: Chantada, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentin