890 research outputs found

    Robust generation of entanglement in Bose-Einstein condensates by collective atomic recoil

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    We address the dynamics induced by collective atomic recoil in a Bose-Einstein condensate in presence of radiation losses and atomic decoherence. In particular, we focus on the linear regime of the lasing mechanism, and analyze the effects of losses and decoherence on the generation of entanglement. The dynamics is that of three bosons, two atomic modes interacting with a single-mode radiation field, coupled with a bath of oscillators. The resulting three-mode dissipative Master equation is solved analytically in terms of the Wigner function. We examine in details the two complementary limits of {\em high-Q cavity} and {\em bad-cavity}, the latter corresponding to the so-called superradiant regime, both in the quasi-classical and quantum regimes. We found that three-mode entanglement as well as two-mode atom-atom and atom-radiation entanglement is generally robust against losses and decoherence,thus making the present system a good candidate for the experimental observation of entanglement in condensate systems. In particular, steady-state entanglement may be obtained both between atoms with opposite momenta and between atoms and photons

    MiR-205-5p inhibition by locked nucleic acids impairs metastatic potential of breast cancer cells

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    Mir-205 plays an important role in epithelial biogenesis and in mammary gland development but its role in cancer still remains controversial depending on the specific cellular context and target genes. We have previously reported that miR-205-5p is upregulated in breast cancer stem cells targeting ERBB pathway and leading to targeted therapy resistance. Here we show that miR-205-5p regulates tumorigenic properties of breast cancer cells, as well as epithelial to mesenchymal transition. Silencing this miRNA in breast cancer results in reduced tumor growth and metastatic spreading in mouse models. Moreover, we show that miR-205-5p knock-down can be obtained with the use of specific locked nucleic acids oligonucleotides in vivo suggesting a future potential use of this approach in therapy

    Attack behavior of Podisus rostralis (Heteroptera: pentatomidade) adults on caterpillars of Bombyx mori (Lepidoptera: bombycidae).

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    Estudou-se, em laboratório, o comportamento de ataque de adultos do predador Podisus rostralis (Stäl) (Heteroptera: Pentatomidae) tendo como presa lagartas de quarto estádio de Bombyx mori L. (Lepidoptera: Bombycidae). Dez adultos do predador, com 24 horas de idade, foram observados durante duas horas acompanhando-se os seguintes comportamentos de ataque: (1) Predador: localização da presa; observação da presa; toque das presas com as antenas; comportamento de ataque; paralisação da presa; fuga do predador após ataque; finalização do ataque; ataques sucessivos; e (2) Presa: defesa. O predador P. rostralis localizou sua presa antes do ataque, aproximando-se dela através de lentos movimentos circulares. O ataque é, usualmente, realizado na parte posterior da presa para reduzir reação de defesa. O maior tamanho da presa em relação ao predador pode dificultar a paralisação, porém o predador consegue paralisá-la em menos de duas horas

    Fall detection using a head-worn barometer

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    Falls are a significant health and social problem for older adults and their relatives. In this paper we study the use of a barometer placed at the user’s head (e.g., embedded in a pair of glasses) as a means to improve current wearable sensor-based fall detection methods. This approach proves useful to reliably detect falls even if the acceleration produced during the impact is relatively small. Prompt detection of a fall and/or an abnormal lying condition is key to minimize the negative effect on health

    Reconhecimento parental e plasticidade fenotípica em duas cultivares de milho em resposta à competição intraespecífica

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    Os cultivos agrícolas são normalmente estabelecidos em sistema de monocultivo, sob adequada disponibilidade hídrica e nutricional, manejo intensivo de plantas daninhas e elevada densidade de plantas altamente relacionadas, como forma de obtenção de altos rendimentos. Essas condições podem ter potencializado a capacidade de reconhecimento parental em plantas cultivadas. Diante do exposto, o objetivo desse trabalho foi avaliar a capacidade de reconhecimento parental e a plasticidade fenotípica em duas cultivares de milho (Zea mays L.) em resposta à competição intraespecífica. Para tal, dois genótipos de milho contratantes quanto ao grau de domesticação (Híbrido e Crioula), foram cultivadas com plantas vizinhas de diferentes graus de parentesco [tratamento entre indivíduos meio-irmão, da população e estranhos (entre cultivares)] e tiveram o crescimento e características morfológicas, fisiológicas e bioquímicas avaliadas. A cultivar Híbrido apresentou um comportamento de reconhecimento parental evitando a competição entre plantas que compartilham algum grau de parentesco, enquanto sob competição com vizinho estranhos respondeu a competição, alterando o padrão de alocação de biomassa, apresentando maior alocação ás raízes em comparação a colmo e folha. Um menor investimento também foi observado em estruturas morfológicas, como altura e, uma maior concentração de clorofila a e total foi observada para a cultivar Híbrido, quando sob competição com indivíduos estranhos. A cultivar Crioula por sua vez, apresentou um mesmo padrão de alocação de biomassa, estruturas morfológicas e fisiológicas entre os tratamentos. Para as variáveis bioquímicas, quando sob competição com indivíduos meio-irmão e da população, as plantas da cultivar Crioula mostraram investir recursos para produção de metabólitos secundários, sugerindo que as respostas de reconhecimento de identidade em espécies de culturas não melhoradas podem envolver alterações metabólicas na planta. Logo, a cultivar Crioula apresentou baixa plasticidade fenotípica em atributos de crescimento, morfológico e fisiológicos em relação à competição intraespecífica e a cultivar Híbrido, em função da maior capacidade de reconhecimento parental, apresentou maior plasticidade fenotípica em atributos relacionados ao crescimento e morfologia

    The application of the Boolean Stochastic Generation Method to model seepage under levees in heterogeneous soils

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    Soil heterogeneity plays an important role in incrementing the uncertainty about the reliability of geotechnical engineering works, especially levees. The presence of thin layers of soils more permeable than the surrounding matrix significantly changes the seepage flow net below and within the dike. However, the detection of these layers is extremely difficult. Consequently, to evaluate the overall safety of dikes it may be useful to adopt stochastic computation methods. The paper presents the calibration of a seepage model of an operational river embankment subject to sand boils. The levee, located along the Adige River (South Tyrol, Italy), has been monitored since 2016. Piezometers and spot temperature sensors are installed in the lateral banks while a distributed fiber optic sensors (FOS), buried in a 350 m long trench at the toe of the levee, is used to check temperature distribution in the subground. The Boolean Stochastic Generation (BoSG) method addresses the influence of layers of material with different properties with respect of the surrounding soil. 360 soil configurations were generated for a two-dimensional groundwater flow model of the levee and confronted with the monitoring data of two piezometers. This analysis permits to identify the configuration that has effects more congruent with piezometers data, which in this case is a configuration with a major presence of lenses on the waterside respect the field-side. This evidence could guide strategies for remedial works

    Amino grafted MCM-41 as highly efficient and reversible ecofriendly adsorbent material for the Direct Blue removal from wastewater

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    The very high adsorption efficiency of Direct Blue (DB), an anionic toxic azo dye, onto amino grafted mesoporous silica nanoparticles (MCM-41), was studied in this paper, for possible industrial applications. Interesting challenges and advances are proposed in this field, presenting an adsorbent able to efficiently and rapidly remove the anionic dye from water. The important added value of this work regards the system recycle, which allows both the DB and adsorbent material recover, with a global reduction of the environmental impact, in the viewpoint of the green economy. Indeed, this paper is the first example of very fast removal and recycle of great amounts of DB with adsorbent materials characterized by impressive adsorption/desorption capacities, at least of around 300mg/g for each adsorption cycle, potentially increasable by performing consecutive cycles of DB adsorption/desorption. In detail, the MCM-41 amino functionalization (MCM-41-NH2) was obtained after (MCM- 41-POST) and during (MCM-41-PRE) the synthesis of MCM-41, obtaining materials with different behavior towards the DB adsorption. The MCM-41-NH2 surface features and porous structure, before and after the dye adsorption, were carefully characterized. Considering the adsorption process, for investigating the nature of the DB/MCM-41-NH2 interaction, several parameters were studied: the contact time, the DB solutions pH values, adsorbent material and dye amount, with the additional analysis of how the adsorption process was influenced by the presence of electrolytes. The isotherms of adsorption were also considered. Although MCM-41-PRE exhibited a higher affinity towards DB molecules, the MCM-41-POST were able to rapidly desorb it, thus recycling both DB and the adsorbent material

    Interaction of mucins with bioinspired polymers and drug delivery particles

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    Mucins are glycoproteins with high molecular weight and an abundance of negatively charged oligosaccharide side chains, representing the main components in the mucous gels apart from water. Mucin structure consists of a flexible backbone (mainly serine and threonine residues) which serves as anchoring points for oligosaccharide side chains, and hydrophobic \u201cnaked domains\u201d enriched in cysteine residues. The latter can form inter-molecular bonds via disulphide links, promoting mucin association in solution. Therefore, mucins can establish adhesive interactions with particulates/biomacromolecules via electrostatic interactions, van der Waals forces, hydrophobic forces, hydrogen bonding, or chain entanglement. Mucosal drug delivery vehicles can either penetrate rapidly or establish prolonged contact. However, their development is of great challenge because little is still known about the interactions between mucin and other macromolecules. We are currently working on a comprehensive study of the interaction between mucin and macromolecules of interest for pharmaceutical developments by complementary techniques. To this scope, we employ biocompatible natural and synthetic polymers with different physical-chemical characteristics. Among them, linear polyamidoamines with amphoteric character are particularly interesting for their cyto-biocompatibility. It is indeed crucial to characterise such interactions not only in the bulk but also at the interface, since complexation between mucins and biomacromolecules takes place close to the cell membrane surface. Moreover, the strategy to overcome mucus barrier and achieve long retention time in the cell surface is to develop nano-agents which can effectively penetrate the mucus layer and accumulate at the epithelial surface. In this framework we present preliminary investigations in the bulk by small angle x-ray scattering (SAXS) and at the solid-liquid interface by employing quartz crystal microbalance (QCM-D)
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