Warm Dark Matter Galaxies with Central Supermassive Black-Holes

We generalize the Thomas-Fermi approach to galaxy structure to include self-consistently and non-linearly central supermassive black holes. This approach naturally incorporates the quantum pressure of the warm dark matter (WDM) particles and shows its full powerful and clearness in the presence of supermassive black holes (SPMHs). We find the main galaxy and central black hole magnitudes: halo radius r_h , halo mass M_h, black hole mass M_BH, velocity dispersion, phase space density, with their realistic astrophysical values, masses and sizes over a wide galaxy range. The SMBH masses arise naturally in this framework. Our extensive numerical calculations and detailed analytic resolution show that with SMBH's, both WDM regimes: classical (Boltzmann dilute) and quantum (compact) do necessarily co-exist in any galaxy: from the smaller and compact galaxies to the largest ones. The transition from the quantum to the classical region occurs precisely at the same point r_A where the chemical potential vanishes. A novel halo structure with three regions shows up: A small quantum compact core of radius r_A around the SMBH, followed by a less compact region till the BH influence radius r_i, and then for r> r_i the known halo galaxy shows up with its astrophysical size. Three representative families of galaxy plus central SMBH solutions are found and analyzed:small, medium and large galaxies having SMBH masses of 10^5, 10^7 and 10^9 M_sun respectively. A minimum galaxy size and mass ~ 10^7 M_sun larger than the one without SMBH is found. Small galaxies in the range 10^4 M_sun < M_h < 10^7 M_sun cannot harbor central SMBHs. We find novel scaling M_BH - r_h - M_h relations. The galaxy equation of state is derived: The pressure P(r) takes huge values in the SMBH vecinity and then sharply decreases entering the classical region following a local perfect gas behaviour.(Abridged)Comment: 31 pages, 14 figures, new materia

Characterisation of cardiomyocyte plasticity and the role of fibroblast during zebrafish heart regeneration

The zebrafish is an established model organism to study heart regeneration, in which pre-existing cardiomyocytes (CMs) proliferate to replace the lost myocardium. During development, mesodermal progenitors from the first heart field (FHF) form a primitive cardiac tube, to which cells from the second heart field (SHF) are added. Here we investigated whether FHF and SHF derivatives in the zebrafish give rise to distinct CM populations, and examined the degree of cell fate plasticity of SHF derivatives during heart regeneration. Using tbx5a-lineage tracing we found that the adult zebrafish heart is also composed of CM populations from the FHF and SHF. Furthermore, ablation of FHF-derived CMs in the embryo is compensated by expansion of SHF derived cells. tbx5a lineage-tracing was also employed to investigate the fate of trabecular CMs during adult heart regeneration. While previous clonal analysis suggested that the different myocardial layers are rebuilt by CMs within each layers, we describe that trabecular CMs can switch their fate and differentiate into cortical myocardium. Heart regeneration is preceded by a fibrotic response. Thus, fibrosis and regeneration are not mutually exclusive responses. Upon cardiac cryoinjury, collagen and other extracellular matrix (ECM) components accumulate at the injury site. Unlike the situation in mammals, fibrosis in zebrafish is transient and its regression is concomitant with regrowth of the myocardial wall. We describe that during fibrosis regression, fibroblasts are not fully eliminated and become inactivated. Unexpectedly, limiting the fibrotic response by genetic ablation of col1a2-expressing cells not only failed to enhance regeneration but also impaired CMs proliferation. We conclude that zebrafish regeneration is a process that requires CM plasticity, and involves ECM-producing cells that become inactive and promote CMs proliferation

Synthesis and characterization of aluminum titanium carbonitride TiAlCN via mechanical alloying

This study presents synthesis of titanium aluminum carbonitrides alloy (TiAlCN) by mechanical alloying in Attritor ball mill from elemental powders of titanium, aluminum and graphite in nitrogen atmosphere. TiAlCN was characterized by SEM, XRD, DSC and FTIR techniques. XRD showed presence of titanium aluminum nitride, aluminum nitride, titanium carbide and titanium aluminum carbon nitride, while SEM showed existence of micro and nano particles with high agglomeration. Energydispersive spectroscopy (EDS) analysis shows a homogeneous distribution of elements, and mapping analysis from X-rays confirms distribution of elements.Peer ReviewedPostprint (published version

Influencia del control de inventarios en la rentabilidad de la empresa Lima Café Gourmet EIRL en la ciudad de Lima, año 2016

Esta Investigación tiene como meta principal el determinar si el control de inventarios afecta la Rentabilidad de la empresa Lima Café Gourmet EIRL, año 2016. La investigación es Básica y el diseño aplicado a la empresa es no experimental y de corte transversal. La población y muestra es la empresa LIMA CAFÉ GOURMET EIRL. Se realizó la definición de las Variables y se elaboró para la presente investigación conforme a las técnicas válidas las encuestas y como instrumento válido lo cuestionarios estructurados

Roles of transcriptional and translational control mechanisms in regulation of ribosomal protein synthesis in Escherichia coli

ABSTRACTBacterial ribosome biogenesis is tightly regulated to match nutritional conditions and to prevent formation of defective ribosomal particles. InEscherichia coli, most ribosomal protein (r-protein) synthesis is coordinated with rRNA synthesis by a translational feedback mechanism: when r-proteins exceed rRNAs, specific r-proteins bind to their own mRNAs and inhibit expression of the operon. It was recently discovered that the second messenger nucleotide guanosine tetra and pentaphosphate (ppGpp), which directly regulates rRNA promoters, is also capable of regulating many r-protein promoters. To examine the relative contributions of the translational and transcriptional control mechanisms to the regulation of r-protein synthesis, we devised a reporter system that enabled us to genetically separate thecis-acting sequences responsible for the two mechanisms and to quantify their relative contributions to regulation under the same conditions. We show that the synthesis of r-proteins from the S20 and S10 operons is regulated by ppGpp following shifts in nutritional conditions, but most of the effect of ppGpp required the 5′ region of the r-protein mRNA containing the target site for translational feedback regulation and not the promoter. These results suggest that most regulation of the S20 and S10 operons by ppGpp following nutritional shifts is indirect and occurs in response to changes in rRNA synthesis. In contrast, we found that the promoters for the S20 operon were regulated during outgrowth, likely in response to increasing nucleoside triphosphate (NTP) levels. Thus, r-protein synthesis is dynamic, with different mechanisms acting at different times.IMPORTANCEBacterial cells have evolved complex and seemingly redundant strategies to regulate many high-energy-consuming processes. InE. coli, synthesis of ribosomal components is tightly regulated with respect to nutritional conditions by mechanisms that act at both the transcription and translation steps. In this work, we conclude that NTP and ppGpp concentrations can regulate synthesis of ribosomal proteins, but most of the effect of ppGpp is indirect as a consequence of translational feedback in response to changes in rRNA levels. Our results illustrate how effects of seemingly redundant regulatory mechanisms can be separated in time and that even when multiple mechanisms act concurrently their contributions are not necessarily equivalent.</jats:p

Ontology-driven International Maize Information System (IMIS) for Phenotypic and Genotypic Data Exchange

The Consultative Group on International Agricultural Research (CGIAR; http://www.cgiar.org/) centres have developed the International Crop Information System (ICIS; http://www.icis.cgiar.org) for the management and integration of global information on genetic resources, and germplasm improvement for any crop. The Maize breeding programs at CIMMYT (http://beta.cimmyt.org/) have different software tools to manage phenotypic, genotypic, and environmental information for their experiments generated worldwide. These tools have the capacity of collecting information in the field, wet lab, and store it into different relational databases. The IMIS (http://imis.cimmyt.org/confluence/display/IMIS/Crop+Finder) is an implementation of the ICIS, which is a computerized database system for general, integrated management and utilization of genealogy, nomenclature, genetic, phenotypic and characterization data for maize. Data exchange within and between databases as well as retrieving information are often hampered by the variability of terms used to describe comparable objects. To overcome this problem, the Crop Ontology (CO) database (http://cropontology.org/) is developed. It provides controlled vocabulary sets for several economically important plant species and facilitates biocurators working in genebanks of plant genetic resources (PGR) and crop breeding data curation and annotation. The maize trait ontology is developed as one of subclasses of CO trait ontology providing standardized trait descriptions, scales and scale values implemented into the IMIS. This ontology-driven IMIS will allow researchers who wish to exploit comparative phenotypic and genotypic information of maize to elucidate functional aspects of each trait