Taxonomic Novelty and Distinctive Genomic Features of Hot Spring Cyanobacteria

Several cyanobacterial species are dominant primary producers in hot spring microbial mats. To date, hot spring cyanobacterial taxonomy, as well as the evolution of their genomic adaptations to high temperatures, are poorly understood, with genomic information currently available for only a few dominant genera, including Fischerella and Synechococcus. To address this knowledge gap, the present study expands the genomic landscape of hot spring cyanobacteria and traces the phylum-wide genomic consequences of evolution in high temperature environments. From 21 globally distributed hot spring metagenomes, with temperatures between 32 and 75 degrees C, 57 medium- and high-quality cyanobacterial metagenome-assembled genomes were recovered, representing taxonomic novelty for 1 order, 3 families, 15 genera and 36 species. Comparative genomics of 93 hot spring genomes (including the 57 metagenome-assembled genomes) and 66 non-thermal genomes, showed that the former have smaller genomes and a higher GC content, as well as shorter proteins that are more hydrophilic and basic, when compared to the non-thermal genomes. Additionally, the core accessory orthogroups from the hot spring genomes of some genera had a greater abundance of functional categories, such as inorganic ion metabolism, translation and post-translational modifications. Moreover, hot spring genomes showed increased abundances of inorganic ion transport and amino acid metabolism, as well as less replication and transcription functions in the protein coding sequences. Furthermore, they showed a higher dependence on the CRISPR-Cas defense system against exogenous nucleic acids, and a reduction in secondary metabolism biosynthetic gene clusters. This suggests differences in the cyanobacterial response to environment-specific microbial communities. This phylum-wide study provides new insights into cyanobacterial genomic adaptations to a specific niche where they are dominant, which could be essential to trace bacterial evolution pathways in a warmer world, such as the current global warming scenario

Electric-field control of domain wall nucleation and pinning in a metallic ferromagnet

The electric (E) field control of magnetic properties opens the prospects of an alternative to magnetic field or electric current activation to control magnetization. Multilayers with perpendicular magnetic anisotropy (PMA) have proven to be particularly sensitive to the influence of an E-field due to the interfacial origin of their anisotropy. In these systems, E-field effects have been recently applied to assist magnetization switching and control domain wall (DW) velocity. Here we report on two new applications of the E-field in a similar material : controlling DW nucleation and stopping DW propagation at the edge of the electrode

Experimental measurements and diffusion in Harbor and coastal zones

Experimental results of turbulent flows in the sea surface near the coastline have been performed using both Lagrangian and Eulerian methods, field tests are presented using video recordings and velocity sensors. The spatial and temporal resolution is limited by the measuring instruments, which results in “filtering” out the very small scales. The experimental field-results obtained during the large-scale surf zone experiments carried out in the Ebro Delta, (Spain), under spilling/plunging breaking waves are compared with experiments performed at the Barcelona harbour. The field-measurements include several tests across the surf zone with high vertical resolution. The measured turbulent properties are compared with macroturbulence characteristics and length parameterisations. Diffusion is measured and related to the local velocity spectra so that a generalized Richardson law may be used

La relevancia de la nueva información transmitida por los dividendos en el mercado de capitales español

En este trabajo pretendemos contrastar el efecto del contenido informativo de los dividendos en el mercado de capitales español. La decisión de reparto de dividendos constituye uno de los temas más controvertidos dentro de las finanzas empresariales presentándose, en palabras de Black, como un rompecabezas cuyas piezas no acaban de encajar entre sí. En un mercado de capitales perfectos esta decisión se convierte en una decisión irrrelevante para las políticas de inversión de las empresas, tal como demostraron Miller y Modigliani. Sin embargo, el escaso poder predictivo de este modelo, bajo el supuesto simplista de ausencia de imperfecciones hace necesario la búsqueda de nuevas respuestas que permitan acercar los pronósticos de la teoría al comportamiento adoptado por las empresas en materia de reparto. Uno de los argumentos que ofrece respuesta a la decisión de dividendos es el que atañe al carácter señalizador de los dividendos. En este sentido, al hilo de las proposiciones que nos sugiere la teoría de la agencia, la política de reparto puede usarse como un vehículo en manos de la gerencia para transmitir información al mercado, en un mundo de asimetrías informativas y donde los internos a la empresa disponen de información privada sobre la marcha de la empresa. La relevancia de la nueva información transmitida por la señal de los dividendos modificará las expectativas que sobre el valor de las acciones tienen los inversores externos, en el caso de que esta información sea significativa y no haya sido descontada con anterioridad. Una vez que hemos expuesto el estado de la cuestión, contrastamos empíricamente si los dividendos transmiten nueva información relevante. Para ello, el estudio se centra en el análisis de las reacciones de los precios de las acciones de la Bolsa de Madrid durante el período 1996-1997 ante anuncios de reparto de dividendos publicados por el Boletín de Cotización de la Bolsa de Madrid. Aplicamos la técnica del suceso para comprobar si existen rentabilidades anormales significativa en tomo a la fecha exdividendo y los períodos anterior y posterior al anuncio. Las peculiaridades informativas que presentan las empresas del sector bancario nos obliga a realizar el estudio por separado del resto de empresas. Los resultados obtenidos nos permiten confirmar las tesis de relevancia de la decisión de dividendos ya que se observa la existencia de rentabilidades anormales significativas en el período de publicación de los dividendos a cuenta, tanto en el sector bancario como en el resto de las empresas. Y con ello, podemos admitir la hipótesis del contenido informativo de los dividendos planteada por la teoría de la agencia y su carácter señalizador para los accionistas extemos sobre la situación de la empresa y su capacidad para generar nuevos fondos en el futuro.This research attempts to check the effect of dividend informative content in the Spanish Capital Market. The decisión of dividend delivery is one of the most controversial issue that becomes a big puzzle which pieces do not match with each other, as Black say

Combining data from primary and ancillary surveys to assess the association between neighborhood-level characteristics and health outcomes: the Multi-Ethnic Study of Artherosclerosis

There is increasing interest in understanding the role of neighborhood-level factors on the health of individuals. Many large-scale epidemiological studies that accurately measure health status of individuals and individual risk factors exist. Sometimes these studies are linked to area-level databases (e.g. census) to assess the association between crude area-level characteristics and health. However, information from such databases may not measure the neighborhood-level constructs of interest. More recently, large-scale epidemiological studies have begun collecting data to measure specific features of neighborhoods using ancillary surveys. The ancillary surveys are composed of a separate, typically larger, set of individuals. The challenge is then to combine information from these two surveys to assess the role of neighborhood-level factors. We propose a method for combining information from the two data sources using a likelihood-based framework. We compare it with currently used ad hoc approaches via a simulation study. The simulation study shows that the proposed approach yields estimates with better sampling properties (less bias and better coverage probabilities) compared with the other approaches. However, there are cases where some ad hoc approaches may provide adequate estimates. We also compare the methods by applying them to the Multi-Ethnic Study of Atherosclerosis and its Neighborhood Ancillary Survey. Copyright © 2008 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61232/1/3384_ftp.pd

Round Turbulent Puffs and Buoyant Thermals in Uniform Crossflows

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76065/1/AIAA-2002-2773-246.pd

Composition influence on pulmonary delivery of rifampicin liposomes

The effects of lipid concentration and composition on the physicochemical properties, aerosol performance and in vitro toxicity activity of several rifampicin-loaded liposomes were investigated. To this purpose, six liposome formulations containing different amounts of soy phosphatidylcholine and hydrogenated soy phosphatidylcholine, with and without cholesterol and oleic acid, were prepared and fully characterized. Uni- or oligo-lamellar, small (~100 nm), negatively charged (~60 mV) vesicles were obtained. Lipid composition affected aerosol delivery features of liposomal rifampicin; in particular, the highest phospholipid concentration led to a better packing of the vesicular bilayers with a consequent higher nebulization stability. The retention of drug in nebulized vesicles (NER%) was higher for oleic acid containing vesicles (55% ± 1.4%) than for the other samples (~47%). A549 cells were used to evaluate intracellular drug uptake and in vitro toxicity activity of rifampicin-loaded liposomes in comparison with the free drug. Cell toxicity was more evident when oleic acid containing liposomes were used