Relativistic correlation correction to the binding energies of the ground configuration of Beryllium-like, Neon-like, Magnesium-like and Argon-like ions

Total electronic correlation correction to the binding energies of the isoelectronic series of Beryllium, Neon, Magnesium and Argon, are calculated in the framework of relativistic multiconfiguration Dirac-Fock method. Convergence of the correlation energies is studied as the active set of orbitals is increased. The Breit interaction is treated fully self-consistently. The final results can be used in the accurately determination of atomic masses from highly charged ions data obtained in Penning-trap experiments.Comment: version soumise 3/08/200

Design of a robust and efficient power electronic interface for the grid integration of solar photovoltaic generation systems

Nowadays, the penetration of photovoltaic (PV) solar power generation in distributed generation (DG) systems is growing rapidly. This condition imposes new requirements to the operation and management of the distribution grid, especially when high integration levels are achieved. Under this scenario, the power electronics technology plays a vital role in ensuring an effective grid integration of the PV system, since it is subject to requirements related not only to the variable source itself but also to its effects on the stability and operation of the electric grid. This paper proposes an enhanced interface for the grid connection of solar PV generation systems. The topology employed consists of a three-level cascaded Z-source inverter that allows the flexible, efficient and reliable generation of high quality electric power from the PV plant. A full detailed model is described and its control scheme is designed. The dynamic performance of the designed architecture is verified by computer simulations.Fil: Pacas, J. M.. Inst. Of Pow. Electro. And Electri. Driv., Univ. Siegen; AlemaniaFil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Dos Santos, E. C.. Universidade Federal de Campina Grande; Brasi

Separating C-stars from Dust in the Central Region of the Seyfert 2 Galaxy NGC 1241

The Sy 2 galaxy NGC 1241 presents a 1.5 kpc large circumnuclear ring of star formation (CNR) embracing a small bar plus leading arms. Those structures are P alpha emitters, but barely seen in H alpha. It presents also stellar trailing arms inside the CNR. GEMINI and HST imagery allow the construction of high resolution (V-H) and (J-K_s) color maps as well as a (J-K_s) vs. K color-magnitude diagram (CMD) of this complex region. The CNR is heavily obscured in V, but a fairly transparent window appears in the direction of the nucleus. Nonetheless, the nucleus presents a (J-K_s) color that is redder than the CNR. The CNR is composed of extremely young HII regions still enshrouded in their dust cocoons. However, the nuclear (J-K_s) color can not be explained in this manner. Therefore, we propose the contribution of C-Stars as the most feasible mechanism for explaining the colors. If the nuclear stellar population is comparable to that of the LMC bar, 500 C-stars and 25000 AGB O-rich stars inside 50 pc may reproduce the observed colors. C-Stars release enriched material to the nuclear environment, probably fueling the central engine of this Sy 2 galaxy during the lifetime of stars with masses between 2 M_sun < M_C-star < 6 M_sun (C-star phase). The ejected material that remains trapped in the central potential might also explain the systematically observed increased strength of the optical CN-bands in Sy 2 galaxies and is consistent with the significant contribution of intermediate age stars to the optical continuum of low luminosity AGNs.Comment: The Astrophysical Journal Letters, accepted. 5 figure

Molecular biology of the dimorphic fungi Paracoccidioides SPP

Paracoccidioides spp, herein commonly referred as Paracoccidioides brasiliensis, is the etiological agent of racoccidioidomycosis (PCM), the most prevalent systemic mycosis endemic in Latin America. Many aspects of the biology of P. brasiliensis remain unknown, in particular its ecology and the apparent lack of a sexual reproduction stage in its life cycle. This review will highlight the current knowledge on the genetics and genomics of P. brasiliensis, its most important putative virulence factors and the challenges for developing genetic tools in this organism. P. brasiliensis is a dimorphic ascomycete fungus belonging to the order Onygenales, family Ajellomycetaceae. The P. brasiliensis pathogenic yeast form is haracterized by a multiple-budding and multinucleate nature, with a highly polymorphic cellular shape. Successful infection and dissemination by P. brasiliensis requires initial interaction of the fungus with host cells. The fungus has to adhere to host cells after which internalization of the fungus takes place. Gp43 is a 43-kDa glycoprotein that participates in the interaction with the host at different levels. There are very few putative virulence factors described in P. brasiliensis,amongthem an extracellular phospholipase B, a 32-kDa haloacid dehalogenase PbHad32 that was shown to bind laminin, fibrinogen, and fibronectin, and to be important for initial adhesion to pulmonary epithelial cells, the pigment melanin, and the Rho-like GTPase PbCdc42. The morphological transition of P. brasiliensis from mycelium to the yeast form is a key process for the infectivity of the fungus. There are several transcriptional profiling studies addressing which genes have increased or decreased mRNA accumulation during mycelium-to-yeast transitions. Functional genomics studies in P. brasiliensis have been hampered by the absence of efficient molecular techniques that enable targeted gene inactivation in this fungus. However, an optimized Agrobacterium tumefaciens-mediated transformation method has been developed and was used to knock-down expression of the genes encoding the Rho-like GTPase PbCdc42 and the HAD-type hydrolase PbHad32. A challenge for the future is the development of mutagenesis methods that allow for the creation of targeted insertional gene mutants in Paracoccidioides spp. The complete genome sequencing of three isolates of Paracoccidioides species provides the opportunity to perform more complete evaluations of the transcriptomic and proteomic data, and to understand the biology and virulence of these important pathogenic fungi.Fundação para a Ciência e Tecnologia (FCT) - Bolsa nº PTDC/BIA-MIC/108309/2008Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento. Científico e Tecnológic

Quasi static mechanical study of vacuum bag infused bouligand inspired composites

Three novel Bouligand inspired composites were produced by vacuum bag infusion manufacturing process and their quasi-static mechanical performance were compared to a conventional aircraft laminate. A morphologic/physical study was first conducted for all configurations and their mechanical response under tensile, three-point bending (3-PB) and interlaminar shear strength (ILSS) tests were then evaluated and discussed. No significant number of voids were detected into laminates, however, a rough and poor defined interlaminar region was observed in both Bouligand-like configurations. Under quasi-static mechanical solicitations, and when compared to reference layup, bioinspired configurations have shown similar and 18% higher tensile and flexural modulus. However, the progressive and translaminar failure mode, typically observed in these configurations, led to a lower load bearing capability. Despite presented similar interlaminar resistance than reference, finite element models built have revealed a good correlation between cross-section stress field and failure mode observed experimentally.Fundação para a Ciência e Tecnologia (FCT), Projetos UIDB/05256/2020, UIDP/05256/2020 e MITP-TB/PFM/0005/201

Interspecies DNA acquisition by a naturally competent Acinetobacter baumannii strain

The human pathogen Acinetobacter baumannii possesses high genetic plasticity and frequently acquires antimicrobial resistance genes. Here we investigated the role of natural transformation in these processes. Genomic DNA from different sources, including from carbapenem-resistant Klebsiella pneumoniae strains, was mixed with A. baumannii A118 cells. Selected transformants were analysed by whole-genome sequencing. In addition, bioinformatics analyses and in silico gene flow prediction were also performed to support the experimental results. Transformant strains included some that became resistant to carbapenems or changed their antimicrobial susceptibility profile. Foreign DNA acquisition was confirmed by whole-genome analysis. The acquired DNA most frequently identified corresponded to mobile genetic elements, antimicrobial resistance genes and operons involved in metabolism. Bioinformatics analyses and in silico gene flow prediction showed continued exchange of genetic material between A. baumannii and K. pneumoniae when they share the same habitat. Natural transformation plays an important role in the plasticity of A. baumannii and concomitantly in the emergence of multidrug-resistant strains.Fil: Traglia, German Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Place, Kori. California State University; Estados UnidosFil: Dotto, Cristian Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Fernandez, Jennifer. California State University; Estados UnidosFil: Montaña, Sabrina Daiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Bahiense, Camila dos Santos. California State University; Estados UnidosFil: Soler Bistue, Alfonso J. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Iriarte, Andres. Universidad de la Republica. Facultad de Medicina; UruguayFil: Perez, Federico. Louis Stokes Cleveland Department Of Veterans Affairs; Estados UnidosFil: Tolmasky, Marcelo E.. California State University; Estados UnidosFil: Bonomo, Robert A.. Louis Stokes Cleveland Department Of Veterans Affairs; Estados UnidosFil: Melano, Roberto Gustavo. Public Health Ontario Laboratories; CanadáFil: Ramirez, Maria Soledad. California State University; Estados Unido

Analysis Of Requirements And Solutions

Several companies have been developing domotic Stds. for building automation, enabling users to locally and remotely control several home devices, like: lights, power sockets, heating, ventilation, and air conditioning systems, among others. Besides contributing to improve the building comfort, these Stds. may also be adopted for other purposes, namely in weblabs used in sciences and engineering remote experiments. To increase the sense of immersion in weblabs, we identify domotic Stds. as a standard solution for turning on/off the power infrastructure and controlling the light and temperature conditions of the physical space where a specific experiment may run, thus approaching the sense of being in the lab facilities while accessing them through the corresponding weblab interface. After identifying the added value to weblabs in terms of power savings and in the control of the environmental conditions, we used our knowledge and the WWW to conduct an extensive search on domotic Stds., and after analysing the results obtained, we choose the most appropriated one to be implemented in a Weblab. Regarding the adopted Std., a proof-of-concept is also described, enabling the control of an halogen lamp and a power socket, using a specific Web interface.info:eu-repo/semantics/publishedVersio

Glomerulonefritis primarias en niños que asisten a un Centro de Referencia en la Región Caribe colombiana

Introduction: Primary glomerulonephritis are diseases that affect the structure and function of the glomerulus. For proliferative glomerulopathies, it has been observed that for IgA and IgM mesangial GN, they are the ones that mostly evolve to end-stage renal failure, followed by membranous-proliferative or mesangiocapillar GN. The clinical manifestation of GN is the result of the combination of hematuria, proteinuria and the presence of acute or chronic renal failure.Material and methods: Medical records were reviewed. They were collected in a database of all biopsies performed from 2008 to 2014. An ?² was used to establish associations between variables (? = 95%). For the differences among proportions Student’s t or U-Mann-Whitney were used.Results: 146 (88%) patients who had complete data were selected. The mean age was 8 ± 4 years old for both sexes. No significant difference was found between gender by age (p? 0.05), nor was there an association between gender and age (p? 0.05). The predominant NGs with the highest prevalence were Proliferative Mesangial and IgA Nephropathy. NGs by Thin Basal Membrane, Nephropathy by C3 and Cq were not present in male patients. The most prevalent syndromic picture was the Nephrotic Syndrome (58%).Conclusions: The existence of this registry of renal biopsies is the basis for the creation of the Registry of Glomerulopathies in children in Colombia, whose data are necessary to establish programs for the treatment and prevention of glomerular diseases in our country in order to decrease its progression.Introducción:Las glomerulonefritis (GN) primarias son enfermedades que afectan a la estructura y función del glomérulo. Dentro de las glomerulopatías proliferativas se ha observado que la GN mesangial por IgA e IgM, son las que evolucionan con mayor frecuencia a la insuficiencia renal permanente; seguida de la GN membrano-proliferativa o mesangiocapilar. La presentación clínica de la GN incluye hematuria, proteinuria e insuficiencia renal aguda o crónica.Material y métodos: Se revisaron las historias clínicas y se acopiaron en una base de datos todas las biopsias realizadas entre los años 2008 a 2014. Se realizó un ?², para establecer las asociaciones entre variables (? = 95%) y para las diferencias entre proporciones se utilizó t de Studentó U- Mann-Whitney.Resultados: Se seleccionaron 146 pacientes (88% del total analizado) que tenían los datos completos. La edad promedio fue de 8±4 años para ambos sexos. No se encontraron diferencias significativasni asociaciones entre el sexo y la edad (p? 0,05). Las GN predominantes fueron las proliferativa mesangial y la nefropatía por IgA. Las GN por membrana basal delgada, nefropatía por C3 y C4 q no se presentaron en varones. La presentación clínica más frecuente fue el Síndrome Nefrótico (58%).Conclusiones: Los hallazgos de éste registro de biopsias renales podrían ser la base para la creación de un Registro de Glomerulopatías en niños en Colombia, instrumento necesario para establecer programas de tratamiento y prevención de las enfermedades glomerulares en nuestro país a fin de disminuir su progresión

Adhesion of freshwater sponge cells mediated by carbohydrate-carbohydrate interactions requires low environmental calcium

Marine ancestors of freshwater sponges had to undergo a series of physiological adaptations to colonize harsh and heterogeneous limnic environments. Besides reduced salinity, river-lake systems also have calcium concentrations far lower than seawater. Cell adhesion in sponges is mediated by calcium-dependent multivalent self-interactions of sulfated polysaccharides components of membrane-bound proteoglycans named aggregation factors. Cells of marine sponges require seawater average calcium concentration (10\xC2\xA0mM) to sustain adhesion promoted by aggregation factors. We demonstrate here that the freshwater sponge Spongilla alba can thrive in a calcium-poor aquatic environment and that their cells are able to aggregate and form primmorphs with calcium concentrations 40-fold lower than that required by marine sponges cells. We also find that their gemmules need calcium and other micronutrients to hatch and generate new sponges. The sulfated polysaccharide purified from S. alba has sulfate content and molecular size notably lower than those from marine sponges. Nuclear magnetic resonance analyses indicated that it is composed of a central backbone of non- and 2-sulfated \xCE\xB1- and \xCE\xB2-glucose units decorated with branches of \xCE\xB1-glucose. Assessments with atomic force microscopy/single-molecule force spectroscopy show that S. alba glucan requires 10-fold less calcium than sulfated polysaccharides from marine sponges to self-interact efficiently. Such an ability to retain multi-cellular morphology with low environmental calcium must have been a crucial evolutionary step for freshwater sponges to successfully colonize inland waters