Simple model for the RF field amplitude dependence of the trapped flux sensitivity in superconducting RF cavities

The improvement of the performance of RF superconducting cavities has recently motivated a considerable research effort in order to elucidate the effect of trapped magnetic flux on the surface resistance $R_{s}$. In this paper we show that by introducing a non-linear pinning force in the Gittleman-Rosenblum equations for the RF power dissipation due to a trapped magnetic flux in a superconductor, we can empirically describe the linear dependence on the RF field amplitude $B_{rf0}$ of the additional surface resistance $R_{fl}$. We also show that the proportionality between the RF-field dependent and independent terms $R_{fl}^{1}$ and $R_{fl}^{0}$, and the frequency dependence of $R_{fl}^{1}$ follow naturally from this approach

Why do educated mothers matter? A model of parental help

The paper investigates the role of mothers in affecting childrens' performance at school. It develops a theoretical model in which household is treated as an individual, whose utility depends on the performance at school of the student and on consumption. The model focuses on the possibilities through which mother’s help may affect pupil's performance in terms of time devoted to supervision and spillover effects. Empirical evidence, using Italian PISA 2006, shows that highly educated mothers have a positive impact on students' score only when they are highly qualified in the job market.Education; PISA; quantile regressions; parental help

Why do educated mothers matter? A model of parental help

This paper investigates the role performed by mothers in affecting their childrens’ performance at school. The article develops firstly a theoretical model in which household (parent - child pair) is treated as an individual, whose utility depends both on the performance at school of the student and on consumption. The model focuses on the different possibilities through which help of mothers may affect pupil’s performance both in terms of time devoted to supervision and spillover effects. Empirical evidence then, using PISA 2006 and focusing on Italian case, shows that education of mothers is an issue when interacted with her occupational status. Highly educated mothers have a positive impact on students’ score only when they are highly qualifed in the job market.Education, PISA, quantile regressions, parental help

Why do educated mothers matter? A model of parental help.

This paper investigates the role performed by mothers in affecting their childrens� performance at school. The article develops �firstly a theoretical modelin which household (parent - child pair) is treated as an individual, whose utility depends both on the performance at school of the student and on consumption. The model focuses on the different possibilities through which help of mothers may affect pupil�s' performance both in terms of time devoted to supervision and spillover effects. Empirical evidence then, using PISA 2006 and focusing on Italian case, shows that education of mothers is an issue when interacted with her occupational status. Highly educated mothers have a positive impact on students�' score only when they are highly qualifi�ed in the job market.PISA 2006, parental help, education

Hydroxyethyl-starch use and PBM. a necessary update to the italian national guidelines

Hydroxyethyl-starch use and PBM a necessary update to the italian national guideline

How we treat bleeding associated with direct oral anticoagulants

Direct oral anticoagulants are at least as effective as vitamin K antagonists for the prevention and treatment of thromboembolism. Unfortunately, differently from vitamin K antagonists, they have the great drawback of lacking specific antidotes in the case of bleeding or emergency situations such as trauma, stroke requiring thrombolysis, and urgent surgery. The progressive development of antidotes for these new drugs, which, it is hoped, will become available in the near future, will allow better and safer management of the rapid reversal of their anticoagulant effect

Establishment and characterization of a brain cell culture model system of myotonic dystrophy type 1

Proyecto de Graduación (Bachillerato en Ingeniería en Biotecnología) Instituto Tecnológico de Costa Rica, Escuela de Biología, 2011Myotonic dystrophy type 1 (DM1) is an autosomal dominant genetic disease caused by the expansion of an unstable CTG repeat in the 3’UTR of the dystrophia myotonica-protein kinase (DMPK) gene. DM1 is the most common form of adult muscular dystrophy. It was initially considered as a muscle disease, but today it is known that DM1 is a multisystemic disease that affects many tissues and organs, including the central nervous system (CNS). Indeed, DM1 patients present debilitating neurological manifestations, such as hypersomnia, cognitive and learning impairment. Congenital DM1 shows severe mental retardation. The unsteady CTG sequence in DM1 tends to expand in size when it is transmitted vertically from one generation to the next. Intergenerational trinucleotide repeat instability serves as the molecular explanation of the phenomenon of anticipation, meaning the increasing severity and decreasing age of onset in successive generations of a DM1 families The repeat is also unstable in somatic tissues, continuing to expand throughout the patient´s life. Important symptoms of DM1 are explained by the nuclear accumulation of toxic, expanded DMPK transcripts and subsequent deregulation of RNA-binding proteins, which leads to missplicing in multiple tissues, including brain. However the molecular pathways contributing to DM1 neuropsychological dysfunction are still unknown. To investigate the disease pathogenesis, DMSXL transgenic mice, carrying large CTG expansions (>1000 repeats) within the human DM1 locus, were generated and studied. In the CNS, these animals show RNA missplicing, as well as Tau hyperphosphorylation, recreating, to a certain extent, the spliceopathy and tauopathy described in humans. A global proteomic approach and the study of candidate genes on DMSXL brains revealed molecular abnormalities in proteins involved in the regulation of calcium metabolism. These findings suggest that the DM1 CTG expansions may affect calcium homeostasis in the CNS. To validate this hypothesis, neuroblastoma and astroglioma cell lines have were transfected with a large CTG repeat expansion. These cell model systems recreate important features of the DM1 molecular pathology, such as toxic RNA accumulation in the nuclei, missplicing of critical candidate genes. Nevertheless, no obvious splicing abnormalities were detected in the list of genes involved in calcium metabolism, selected for this study. In contrast to the findings reported in skeletal muscle and heart of DM1 patients, CELF1 expression was not significantly changed by the CTG expansion in cultured brain cells. In conclusion, the presence of foci and missplicing of some candidate genes validates our brain model system of DM1-associated RNA toxicity. However, the system may require further studies and refinement to perform functional analysis of calcium metabolism and flux at later stages.La Distrofia Miotónica tipo 1 (DM1) es una enfermedad genética autosómica dominante causada por la expansión inestable de las repeticiones CTG en la región 3’UTR del gen de la distrofia miotónica de una proteína kinasa (DMPK). DM1 es la forma adulta más común de distrofia muscular. Inicialmente fue considerada como una enfermedad muscular, hoy en día se sabe que DM1 es una enfermedad multisistémica que afecta a varios tejidos y órganos, incluyendo el sistema nervioso central (SNC). En efecto, los pacientes con DM1 presentan debilitamiento neurológico, así como hipersomnolencia, discapacidades cognitivas y de aprendizaje. La forma congénita de DM1 muestra retardo mental severo. La poca estabilidad de la secuencia CTG en DM1 tiende a expandirse en tamaño cuando se transmite de manera vertical de una generación a la siguiente. El desequilibrio de las repeticiones trinucleótidas intergeneracionales sirve como explicación molecular del fenómeno de anticipación, indicando un aumento en la severidad y una disminución en la edad de inicio en generaciones sucesivas de una familia con DM1. La repetición también es inestable en tejidos somáticos, expandiéndose a través de la vida del paciente. Algunos síntomas importantes de DM1 son explicados por la acumulación nuclear de toxinas, transcritos extendidos de DMPK y subsecuentemente la desregulación de ARNs que unen proteínas, lo cual origina el editaje incorrecto en múltiples tejidos, incluyendo el cerebro. Por otro lado el mecanismo molecular que contribuye a la neurodisfunción sicológica en DM1 sigue siendo desconocido. Para investigar la patogénesis de la enfermedad, se creó y estudio el ratón transgénico DMSXL, que contiene largas expansiones de CTG (>1000 repeticiones) de humanos. En el SNC, estas anormalidades muestran missplicing del ARN, así como la hiperfosforilación de Tau, recreando la spliceopatía y taupatía descrita en humanos. Un enfoque global proteómico y el estudio de genes candidatos en muestras de cerebro del ratón DMSXL revela anormalidades moleculares en proteínas involucradas en la regulación del metabolismo del calcio. Estos descubrimientos sugieren que las expansiones de la repetición CTG en DM1 pueden afectar la homeostasis de calcio en el SNC. Para validar esta hipótesis, líneas celulares de neuroblastoma y astroglioma fueron transfectadas con expansiones de las repeticiones de CTG. Este modelo celular recrea importantes características de la patología molecular de DM1, como la acumulación de ARN tóxico en el núcleo y el missplicing en genes candidatos críticos. Sin embargo, no se detectó anormalidades en el proceso de corte y empalme para la lista de genes candidatos analizados y relacionados al metabolismo del calcio en este estudio. En contraste con lo reportado en estudios previos de muestras musculares y cardiacas de pacientes con DM, los cambios en la expresión de CELF1 no fueron significativos en las células cerebrales que contenían la expansión de CTG. En conclusión, la presencia de foci y missplicing en algunos genes candidatos valida este sistema modelo de células cerebrales como útil para estudiar la enfermedad DM1 asociado a la toxicidad del ARN. Por otro lado, el sistema requiere otros estudios y el desarrollo refinado de análisis funcionales del metabolismo y flujo de calcio en etapas posteriores

Zika virus and the never-ending story of emerging pathogens and transfusion medicine

In the last few years, the transfusion medicine community has been paying special attention to emerging vector-borne diseases transmitted by arboviruses. Zika virus is the latest of these pathogens and is responsible for major outbreaks in Africa, Asia and, more recently, in previously infection-naïve territories of the Pacific area. Many issues regarding this emerging pathogen remain unclear and require further investigation. National health authorities have adopted different prevention strategies. The aim of this review article is to discuss the currently available, though limited, information and the potential impact of this virus on transfusion medicine

Water and identity:: an urban case study for densification along Los Angeles River's Rio Hondo Confluence

When Los Angeles was founded in 1781, the mountains, river and shore formed the landscape. Today, street grids and a superimposed network of meandering freeways blanket the valleys while clusters of high-rises emerge periodically to provide underpinnings of the city's identifiable neighborhoods. Only the Los Angeles River is invisible, reduced to concrete-lined drainage channels, denuded of riparian vegetation, bounded by rail lines, hidden behind industrial plants and beneath freeways. What is a river without water? Throughout landscapes, urban and rural alike, rivers and infrastructure intertwine like tendons to connect cities to natural resources and each other. This dance is particularly evident in an 11-mile stretch of the 51-mile river referred to as Reach 2 where the 710 Long Beach Freeway parallels, elevates, and hurdles the concrete-lined depression of the barren riverbed. Ten cities comprise Reach 2, which fail to garner the attention of Downtown Los Angeles to the north and the Long Beach estuary to the south. As a result of this intermittency, these cities suffer from social and infrastructural neglect, while struggling to develop positive community identity. In modern multi-city metropolitan areas, governmental centers dominate the political infrastructure. Meanwhile, physical infrastructures, such as freeways, often divide these cities. This research seeks to invert these paradigms in an effort to celebrate city identity at political borders, and transform physical divisions into cultural connections. Research and a design prototype were developed in a unique multi-disciplinary graduate studio environment. Reach 2 is compared to Tokyo to extract potential community identities to support dense and vibrant future development. Additionally, an innovative four-dimensional land-use analysis is conducted across the region to identify voids/opportunities for optimal multi-use development. These investigations culminate in a design prototype at the Rio Hondo Confluence