Optical properties of metal nanoparticles with arbitrary shapes

We have studied the optical properties of metallic nanoparticles with arbitrary shape. We performed theoretical calculations of the absorption, extinction and scattering efficiencies, which can be directly compared with experiments, using the Discrete Dipole Approximation (DDA). In this work, the main features in the optical spectra have been investigated depending of the geometry and size of the nanoparticles. The origin of the optical spectra are discussed in terms of the size, shape and material properties of each nanoparticle, showing that a nanoparticle can be distinguish by its optical signature.Comment: 19 pages + 8 figure

Mourning, Activism, and Queer Desires. Ni Una Menos and Carri’s Las hijas del fuego

Argentina’s neoconservative backlash (2015–2019) has rather paradoxically been marked by an unprecedented entanglement of ongoing memory struggles and a recent feminist awakening. A critical reading of this entwining traces the queer reworking of dictatorship trauma during the Kirchnerist administrations (2003–2015) and explores the way the post-2015 cycle nurtured a feminist irruption that contested long-standing forms of patriarchy. The feminist movement Ni Una Menos has transitioned from victimization to joy. Albertina Carri’s lesbian-porn fictional film Las hijas del fuego (2018) can be read as an expression of a novel amalgam of disappearance, sexuality, and politics. The spirit of contagion radiated by the film sheds light on the “revolution of the daughters” now taking place in the streets

Estudio experimental de desarrollo de gel de extracto de propóleo como coadyuvante en el control de dolor y el proceso de cicatrización post extracción dental.

El reemplazo de terapéutica de tipo alópata por agentes naturales resulta una alternativa para pacientes con compromiso sistémico o síndrome de polifarmacia. El propóleo constituye una opción debido a sus propiedades antimicrobianas, analgésica y antiinflamatorias. Debido a las características bioquímicas de la mucosa oral es necesario emplear un vehículo para su colocación y aprovechar las propiedades del propóleo. En este estudio se propone la utilización de un gel a base de carbopol 934, trietanolamina y glicerina como vehículo. MATERIALES Y MÉTODOS. Se elaboró el gel base mediante la fusión de 100 ml de agua desmineralizada, glicerina 3.5 g y 1 g de carbopol 934 P. Pasadas 24 horas se incorporó trietanolamina 50% 0.8 g hasta lograr un pH 7. En una proporción 1:1 se adiciona lentamente el extracto de propóleo 65% al gel base. RESULTADOS. Al evaluar la consistencia del producto se oservó una mezcla homogénea, sin embargo al dejarlo en reposo se observó tres horas después un decaimiento en la viscosidad del mismo. CONCLUSIONES. Es necesario reevaluar los componentes del gel base con el fin de lograr una mucoadhesión deseada así como mejorar las propiedades físicas del mismo

Performance, Kinship and Archives: Queering Acts of Mourning in the Aftermath of Argentina’s 1976-1983 Dictatorship.

PhDIn the aftermath of Argentina’s last dictatorship (1976-1983), the organisations created by the relatives of the disappeared deployed the trope of a ‘wounded family’. The unspoken rule was that only those related by blood to the missing were entitled to ask for justice. This thesis queers this biological tradition. Drawing from performance studies and queer theory, it develops an alternative framework for understanding the transmission of trauma beyond bloodline inscriptions. It shows how grief brought into light an idea of community that exceeds traditional family ties. In order to demonstrate this, the thesis builds an archive of non-normative acts of mourning. This archive crosses different generations. The introduction utilises the Mothers of Plaza de Mayo’s statement ‘Our Children gave birth to us’ as the departure for a non-biological linage. Chapter 1 shows how the black humour that informs H.I.J.O.S., the association created by the children of the disappeared, works as a form of affective reparation in the face of loss. Chapter 2 proposes a dialogue between Los Rubios (Albertina Carri, 2003), M (Nicolás Prividera, 2007) and La mujer sin cabeza (Lucrecia Martel, 2008) to show how these films manage to displace the normative cult of the victim. Chapter 3 conceives the cooking sessions that take place at ESMA former detention camp as a form of conversion of this site of death. Chapter 4 explores Lola Arias’ Mi vida después (2009) as an intergenerational artefact for the transmission of trauma on- and off-stage. Chapter 5 considers Félix Bruzzone’s novella Los topos (2008) as the announcement of a new language of kinship. In conclusion, the thesis argues that the aftermath of violence not only produced pain but also new forms of pleasure. Ultimately, it sheds light on a new sense of ‘being together’ that has emerged in the wake of loss.Overseas Research Students Awards Scheme (ORSAS); University of London Central Research Fund; Society for Latin American Studies; SCUDD, IOHA and SLAS for conference scholarship

Critical parameters of the in vitro method of vascular smooth muscle cell calcification

[Background]: Vascular calcification (VC) is primarily studied using cultures of vascular smooth muscle cells. However, the use of very different protocols and extreme conditions can provide findings unrelated to VC. In this work we aimed to determine the critical experimental parameters that affect calcification in vitro and to determine the relevance to calcification in vivo. [Experimental Procedures and Results]: Rat VSMC calcification in vitro was studied using different concentrations of fetal calf serum, calcium, and phosphate, in different types of culture media, and using various volumes and rates of change. The bicarbonate content of the media critically affected pH and resulted in supersaturation, depending on the concentration of Ca2+ and Pi. Such supersaturation is a consequence of the high dependence of bicarbonate buffers on CO2 vapor pressure and bicarbonate concentration at pHs above 7.40. Such buffer systems cause considerable pH variations as a result of minor experimental changes. The variations are more critical for DMEM and are negligible when the bicarbonate concentration is reduced to ¿. Particle nucleation and growth were observed by dynamic light scattering and electron microscopy. Using 2mM Pi, particles of ~200nm were observed at 24 hours in MEM and at 1 hour in DMEM. These nuclei grew over time, were deposited in the cells, and caused osteogene expression or cell death, depending on the precipitation rate. TEM observations showed that the initial precipitate was amorphous calcium phosphate (ACP), which converts into hydroxyapatite over time. In blood, the scenario is different, because supersaturation is avoided by a tightly controlled pH of 7.4, which prevents the formation of PO43--containing ACP. [Conclusions]: The precipitation of ACP in vitro is unrelated to VC in vivo. The model needs to be refined through controlled pH and the use of additional procalcifying agents other than Pi in order to reproduce calcium phosphate deposition in vivo.Funding was provided by a research grant SAF2012-33898 to VS, http://www.mineco.gob.es/portal/site/mineco/idi, Spanish Ministry of Economy and Competitiveness; research grant MAT2014-54975-R to AM, http://www.mineco.gob.es/portal/site/mineco/idi, Spanish Ministry of Economy and Competitiveness.Peer Reviewe

Intention Reconsideration like uncertain dichotomous choice model

A key issue in the design of Belief-Desires-Intentions (BDI) agents is that of fnding an appropriate strategy for Intention Reconsider- ation (IR). Traditional approaches to IR defi nes the policy in the agent's design stage, which makes impossible to modify it in execution time. This is clearly not a practical solution for agents operating in dynamic and changing environments. Besides, IR typically involves considering multi- ple criteria. That is why, in this work, we propose a novel approach to IR based on a dichotomous choice model. This approach allows changing commitments to intentions depending on how the environment evolves and involves multi-criteria aggregation for IR.Eje: XV Workshop de Agentes y Sistemas InteligentesRed de Universidades con Carreras de Informática (RedUNCI

Effects of oral exposure to arsenite on arsenic metabolism and transport in rat kidney

Nephrotoxicity is within the recognized toxic effects of arsenic. In this study we assessed the effect of arsenite on the renal capacity to metabolize and handle arsenicals in rats exposed to drinking water with 0, 1, 5, or 10 ppm sodium arsenite for ten days. Arsenite treatment did not affect the gene expression of the main enzyme catalyzing methylation of arsenite, As3mt, while it reduced the expression of GSTO1 mRNA and protein. Arsenite decreased the expression of Aqp3, Mrp1, Mrp4, and Mdr1b (i.e., transporters and channels used by arsenic), but not that of Aqp7, Glut1, Mrp2, and Mdr1a. The protein abundance of AQP3 was also reduced by arsenite. Arsenite increased urinary NGAL and FABP3 and decreased Klotho plasma levels, without alteration of creatinine, which evidenced early tubular damage. Renal Klotho mRNA and protein expressions were also downregulated, which may exacerbate renal damage. No effect was observed in selected miRNAs putatively associated with renal injury. Plasma PTH and FGF23 were similar between groups, but arsenite decreased the renal expression of Fgfr1 mRNA. In conclusion, exposure to arsenite alters the gene expression of proteins involved in the cellular handling of arsenical species and elicits tubular damage

Several phosphate transport processes are present in vascular smooth muscle cells

We have studied Pi handling in rat aortic vascular smooth muscle cells (VSMC) using 32P-radiotracer assays. Our results have revealed a complex set of mechanisms consisting in 1) well-known PiT1/PiT2-mediated sodium-dependent Pi transport; 2) Slc20-unrelated sodium-dependent Pi transport that is sensitive to the stilbene derivatives 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) and (4-acetamido-4-isothiocyanostilbene-2,2-disulfonate) (SITS); 3) a sodium-independent Pi uptake system that is competitively inhibited by sulfate, bicarbonate, and arsenate and is weakly inhibited by DIDS, SITS, and phosphonoformate; and 4) an exit pathway from the cell that is partially chloride-dependent and unrelated to the known anion-exchangers expressed in VSMC. The inhibitions of sodium-independent Pi transport by sulfate and of sodium-dependent transport by SITS were studied in greater detail. The maximal inhibition by sulfate was similar to that of Pi itself, with a very high inhibition constant (212 mM). SITS only partially inhibited sodium-dependent Pi transport, but the Ki was very low (14 µM). Nevertheless, SITS and DIDS did not inhibit Pi transport in Xenopus laevis oocytes expressing PiT1 or PiT2. Both the sodium-dependent and sodium-independent transport systems were highly dependent on VSMC confluence and on the differentiation state, but they were not modified by incubating VSMC for 7 days with 2 mM Pi under non-precipitating conditions. This work not only shows that the Pi handling by cells is highly complex, but also that the transport systems are shared with other ions such as bicarbonate or sulfate

El agua, excesos y déficits, en la producción agrícola de secano y pecuaria dentro de la cuenca inferior del río Salado

[Resumo] Nesta tese preséntanse as características dunha conca de chaira. Ponse énfase no funcionamento das augas subterráneas porque son as de máis doado acceso polo produtor agropecuario. Intégrase dentro da conca inferior do Río Salgado todo o sector de Baixos Submeridionais e utilízase a valiosa ferramenta que outorgan os Sistemas de Información Xeográfica para realizar planos e análises gráficas. Formúlanse os "sistemas hidroxeolóxicos non típicos" e trátase de validar un modelo conceptual para a rexión dende o punto de vista hidroxeolóxico, como é o proposto por Tóth (1963). O propósito de analizar o funcionamento do sistema é formular un camiño de coñecemento do medio que sexa a base para manter unha produción equilibrada ou, polo menos, coñecer os riscos de determinadas accións. Todo o traballo está baseado en datos de campo que se elaboraron ao longo de décadas de estudo na zona, complementado con estudos recentes. Formúlase a produción en zonas con climas moi variantes que, en poucos anos, provocan tanto inundacións desvastadoras como secas angustiosas. Preséntase a recarga artificial como medio para aumentar o reservorio subterráneo e paliar as crises en períodos de secas. Formúlase o coñecemento das augas subterráneas por parte dos produtores antes de sementar, para poder analizar os seus riscos. En ambas as dúas rexións propóñense os reservorios de auga para almacenamento durante os excesos e a evacuación controlada. Por último, conclúese que é posible realizar unha produción sustentable se se posúe unha boa base sobre o coñecemento da natureza. Esta tese baséase na recompilación, ordenamento e análise da información e plantexa direccións a explorar, como a recarga artificial de acuíferos.[Resumen] En esta tesis se presentan las características de una cuenca de llanura. Se pone énfasis en el funcionamiento de las aguas subterráneas por que son las de más fácil acceso por el productor agropecuario. Se integra dentro de la cuenca inferior del Río Salado todo el sector de Bajos Submeridionales y se utiliza la valiosa herramienta que otorgan los sistemas de información Geográfica para realizar planos y análisis gráficos. Se plantean los “sistemas hidrogeológicos no típicos” y se trata de validar un modelo conceptual para la región desde el punto de vista hidrogeológico como es el propuesto por Tóth (1963) y Tóth (2000). El propósito de analizar el funcionamiento del sistema es para plantear un camino de conocimiento del medio que sea la base para mantener una producción equilibrada o por lo menos conocer los riesgos de determinadas acciones. Todo basado en datos de campo que se han elaborado a lo largo de décadas de estudio en la zona complementado con estudios recientes. Se plantea la producción en zonas con climas muy variantes que en pocos años se pasa de inundaciones devastadoras a sequías angustiosas. Se presenta la recarga artificial como medio para aumentar el reservorio subterráneo y palear las crisis en períodos de sequías. Se plantea el conocimiento de las aguas subterráneas por parte de los productores antes de sembrar para poder analizar sus riesgos. En ambas regiones se proponen los reservorios de agua para almacenamiento durante los excesos y la evacuación controlada. Por último, se concluye que es posible realizar una producción sustentable si se posee una buena base sobre el conocimiento de la naturaleza, esta tesis pretende aportar en la recopilación, ordenamiento, análisis de la información y deja planteados direcciones a explorar como la recarga artificial de acuíferos.[Abstract] This thesis presents the characteristics of a flatland basin with emphasis on the dynamic of ground water that are more easily accessible for farmers. The selected place belongs to Rio Salado inferior basin, within the Bajos Submeridionales region. It is used the powerful tool provided by Geographic Information Systems for drawing planes and graphical analysis. The concept of “non-typical hydrogeologic systems” is postulated and there is an attempt to validate the hydrogeologic conceptual model for the region, based on the model proposed by Tóth (1963) y Tóht (2000). The purpose of analyzing the performance of the system is to proposed an approach in which knowledge of the environment is the basis for maintaining a balanced production, or at least know the risk associated with certain actions. This work is based on data field compiled through decades of research, complemented with recent studies. Farming is posed in areas with widely varying climates in a few years go from devastating floods to distressing droughts. Artificial recharge is presented as a mean to increase the underground reservoir and mitigate crisis in periods of drought. Awareness of groundwater condition before planting is highlighted in order to analyze risks for producers or farmers. In both regions water storage reservoirs are proposed to manage excess and controlled evacuation. Finally, it is concluded that sustainable production is possible if there is good basic knowledge of nature. This thesis seeks to contribute in the collection, management, analysis of data and set directions to explore as artificial recharge of aquifers