The Vortex-Wave equation with a single vortex as the limit of the Euler equation

In this article we consider the physical justification of the Vortex-Wave equation introduced by Marchioro and Pulvirenti in the case of a single point vortex moving in an ambient vorticity. We consider a sequence of solutions for the Euler equation in the plane corresponding to initial data consisting of an ambient vorticity in $L^1\cap L^\infty$ and a sequence of concentrated blobs which approach the Dirac distribution. We introduce a notion of a weak solution of the Vortex-Wave equation in terms of velocity (or primitive variables) and then show, for a subsequence of the blobs, the solutions of the Euler equation converge in velocity to a weak solution of the Vortex-Wave equation.Comment: 24 pages, to appea

Acute toxicity, bioaccumulation and effects of dietary 1 transfer of silver from brine 2 shrimps exposed to PVP/PEI-coated silver nanoparticles to zebrafish

The extensive use and release to the aquatic environment of silver nanoparticles (NPs) could lead to their incorporation into the food web. Brine shrimp larvae of 24 h showed low sensitivity to the exposure to PVP/PEI-coated Ag NPs (5 nm), with EC50 values at 24 h of 19.63 mg Ag L-1, but they significantly accumulated silver after 24 h of exposure to 100 μg L-1 of Ag NPs. Thus, to assess bioaccumulation and effects of silver transferred by the diet in zebrafish, brine shrimp larvae were exposed to 100 ng L-1 of Ag NPs as an environmentally relevant concentration or to 100 μg L-1 as a potentially effective concentration and used to feed zebrafish for 21 days. Autometallography revealed a dose- and time-dependent metal accumulation in the intestine and in the liver of zebrafish. Three-day feeding with brine shrimps exposed to 100 ng L-1 of Ag NPs was enough to impair fish health as reflected by the significant reduction of lysosomal membrane stability and the presence of vacuolization and necrosis in the liver. However, dietary exposure to 100 μg L-1 of Ag NPs for 3 days did not significantly alter gene transcription levels, neither in the liver nor in the intestine. After 21 days, biological processes such as lipid transport and localization, cellular response to chemical stimulus and response to xenobiotic stimulus were significantly altered in the liver. Overall, these results indicate an effective dietary transfer of silver and point out to liver as the main target organ for Ag NP toxicity in zebrafish after dietary exposure.MINECO (NanoSilverOmicsproject- MAT2012-39372) Basque Government (consolidated research groups IT810-13 and IT620-13; Saiotek S-PE13UN142) University of the Basque Country (UFIs 11/37 and 11/52)

: An image is worth a thousand words: the effects of visual health warnings in the decrease of tobacco consumption: a research from the perspective of social marketing

Tobacco is considered a high-risk product, associated with multiple illnesses and representing an indisputable threat for Public Health. Amongst the measures proposed by the World Health Organisation and the European Commission for controlling its use, is the employment of health warnings about the dangers of tobacco consumption. In Spain, these warnings only contain text messages. The present study focuses on assessing the efficacy of current text warnings, and on studying the potential impact of a library of images created by the European Commission on consumer behavior. This research takes place within a network of projects currently developed in France and the United Kingdom and presents results obtained in Spain by using qualitative methodology -in depth interviews-.El tabaco está reconocido hoy día como un factor de riesgo muy importante en multitud de enfermedades, representando un grave riesgo para la salud pública. Entre las medidas previstas por la Organización Mundial de la Salud y por la Comisión Europea está la utilización de advertencias sanitarias sobre los efectos del tabaco en las personas. En España actualmente esas advertencias contienen solo texto. El presente trabajo centra su atención en conocer la eficacia de esas advertencias sanitarias actuales y conocer la eficacia potencial que podrían tener un banco de imágenes y texto creadas por la Unión Europea. Este trabajo forma parte de una red de proyectos que se están desarrollando también en Reino Unido y Francia y presenta los resultados realizados con metodología cualitativa -entrevistas en profundidad-

Decrease in calcitonin and parathyroid hormone mRNA levels and hormone secretion under long-term hypervitaminosis D3 in rats

In calcium homeostasis, vitamin D3 is a potent serum calcium-raising agent which in vivo regulates both calcitonin (CT) and parathyroid hormone (PTH) gene expression. Serum calcium is the major secretagogue for CT, a hormons product whose biosynthesis is the main biological activity of thyroid Ccells. Taking advantage of this regulatory mechanism, long-term vitamin D3-induced hypercalcemia has been extensively used as a model to produce hyperactivation, hyperplasia and even proliferative lesions of C-cells, supposedly to reduce the sustained high calcium serum concentrations. We have recently demonstrated that CT serum levels did not rise after long-term hypervitaminosis D3. Moreover, C-cells did not have a proliferative response, rather a decrease in CT-producing C-cell number was observed. In order to confirm the inhibitory effect of vitamin D3 on C-cells, Wistar rats were administered vitamin D3 chronically (25,000 IUId) with or without calcium chloride (CaC12). Under these long-term vitaminD -hypercalcemic conditions, calcium, active metaboetes of vitamin 4 , CT and PTH serum concentrations were determined by RIA; CT and PTH mRNA levels were analysed by Northern blot and in situ hybridization; and, finally, the ultrastructure of calciotrophic hormone-producing cells was analysed by electron microscapy. Our results show, that, in rats, long term administration of vitamin D3 results in a decrease in hormone biosynthetic activities of both PTH and CTproducing cells, albeit at different magnitudes. Based upon these results, we conclude that hypervitaminosis D3-based methods do not stimulate C-cell activity and can not be used to induce proliferative lesions of calcitonin-producing cells

Thyrotropin-releasing hormone receptor expression in thyroid follicular cells: a new paracrine role of C-cells?

Thyrotropin-releasing hormone (TRH) synthesized in the hypothalamus has the capability of inducing the release of thyroid-stimulating hormone (TSH) from the anterior pituitary, which in turn stimulates the production of thyroid hormones in the thyroid gland. Immunoreactivity for TRH and TRH-like peptides has been found in some tissues outside the nervous system, including thyroid. It has been demonstrated that thyroid C-cells express authentic TRH, affecting thyroid hormone secretion by follicular cells. Therefore, C-cells could have a paracrine role in thyroid homeostasis. If this hypothesis is true, follicular cells should express TRH receptors (TRH-Rs) for the paracrine modulation carried out by C-cells. In order to elucidate whether or not C-cell TRH production could act over follicular cells modulating thyroid function, we studied TRH-Rs expression in PC C13 follicular cells from rat thyroid, by means of immunofluorescence technique and RT-PCR analysis. We also investigated the possibility that C-cells present TRH-Rs for the autocrine control of its own TRH production. Our results showed consistent expression for both receptors, TRH-R1 and TRH-R2, in 6-23 C-cells, and only for TRH-R2 in PC C13 follicular cells. Our data provide new evidence for a novel intrathyroidal regulatory pathway of thyroid hormone secretion via paracrine/autocrine TRH signaling

Percepciones del envase neutro del tabaco entre fumadores y no fumadores en Andalucía (España)

Objectives: Each year tobacco is responsible for 650, 000 deaths in Europe and 55, 000 in Spain. With tobacco advertising and promotion banned in Spain and most of Europe, the last bastion of marketing is the packaging. Plain tobacco packaging —which involves packs having a standardised appearance— has been proposed to counter this. The objective of this study is to research perceptions arising from the plain packaging of tobacco products. Methods: We employed a qualitative research methodology -focus groups- with smokers and non-smokers in in two medium-sized Andalusian towns (Spain). Results: Results show the importance of plain cigarette packaging as a form of promotion, particularly among women and young people, how pack colour influences product perceptions, and how removing full branding increases the salience of the warnings. Conclusions: Plain packaging, combined with pictorial health warnings, may reduce the capacity of packaging to be distinctive and a badge product. Altering pack design in such a way would make it more difficult for tobacco companies to create a favourable image of their brands and may help to reinforce the ability of the population to protect themselves from the dangers of smoking

Immunophenotypical and functional heterogeneity of dendritic cells generated from murine bone marrow cultured with different cytokine combinations: implications for anti-tumoral cell therapy

Dendritic cells (DC) are professional antigen-presenting cells that can be used as immune adjuvant for anti-tumoural therapies. This approach requires the generation of large quantities of DC that are fully characterized on the immunophenotypical and functional levels. In a murine model, we analysed the in vitro effects of granulocyte–macrophage colony-stimulating factor (GM-CSF) alone or combined with interleukin-4 (IL-4) or Flt3 ligand (Flt3-L) on the number, immunophenotype and functions of bone marrow-derived DC. In GM-CSF cultures, we have identified two populations based on their level of expression of major histocompatibility complex (MHC) class II molecules: MHC-IIhi cells, exhibiting the typical morphology and immunophenotype of myeloid DC (CD11c+ 33D1+ DEC-205+ F4/80+), and MHC-IIlo cells, heterogeneous for DC markers (30% CD11c+; 50% 33D1+; DEC-205−; F4/80+). The addition of Flt3-L to GM-CSF induced a twofold increase in MHC-IIhi DC number; besides, the MHC-IIlo cells lost all DC markers. In contrast, after addition of IL-4 to GM-CSF, the two populations displayed a very similar phenotype (CD11c+ 33D1− DEC-205+ F4/80−), differing only in their expression levels of MHC class II and costimulatory molecules, and showed similar stimulatory activity in mixed leucocyte reaction. We next analysed the migration of these cultured cells after fluorescent labelling. Twenty-four hours after injection into the footpads of mice, fluorescent cells were detected in the draining popliteal lymph nodes, with an enhanced migration when cells were cultured with GM-CSF+Flt3-L. Finally, we showed that MHC-IIhi were more efficient than MHC-IIlo cells in an anti-tumoral vaccination protocol. Altogether, our data highlight the importance of characterizing in vitro-generated DC before use in immunotherapy