Hybrid classical-quantum formulations ask for hybrid notions

We reappraise some of the hybrid classical-quantum models proposed in the literature with the goal of retrieving some of their common characteristics. In particular, first, we analyze in detail the Peres-Terno argument regarding the inconsistency of hybrid quantizations of the Sudarshan type. We show that to accept such hybrid formalism entails the necessity of dealing with additional degrees of freedom beyond those in the straight complete quantization of the system. Second, we recover a similar enlargement of degrees of freedom in the so-called statistical hybrid models. Finally, we use Wigner's quantization of a simple model to illustrate how in hybrid systems the subsystems are never purely classical or quantum. A certain degree of quantumness (classicality) is being exchanged between the different sectors of the theory, which in this particular unphysical toy model makes them undistinguishable.Comment: 13 pages, 3 figures (minor changes to match the published version

Optimization of a large-scale gene disruption protocol in Dictyostelium and analysis of conserved genes of unknown function

BACKGROUND: Development of the post-genomic age in Dictyostelium will require the existence of rapid and reliable methods to disrupt genes that would allow the analysis of entire gene families and perhaps the possibility to undertake the complete knock-out analysis of all the protein-coding genes present in Dictyostelium genome. RESULTS: Here we present an optimized protocol based on the previously described construction of gene disruption vectors by in vitro transposition. Our method allows a rapid selection of the construct by a simple PCR approach and subsequent sequencing. Disruption constructs were amplified by PCR and the products were directly transformed in Dictyostelium cells. The selection of homologous recombination events was also performed by PCR. We have constructed 41 disruption vectors to target genes of unknown function, highly conserved between Dictyostelium and human, but absent from the genomes of S. cerevisiae and S. pombe. 28 genes were successfully disrupted. CONCLUSION: This is the first step towards the understanding of the function of these conserved genes and exemplifies the easiness to undertake large-scale disruption analysis in Dictyostelium

Molecular Networks in Dynamic Multilevel Systems

Dynamic multilevel systems can be assembled from molecular building blocks through two or more reversible reactions that form covalent bonds. Molecular networks of dynamic multilevel systems can exhibit different connectivities between nodes. The design and creation of molecular networks in multilevel systems require control of the crossed reactivity of the functional groups (how to connect nodes) and the conditions of the reactions (when to connect nodes). In recent years, the combination of orthogonal and communicating reactions, which can be simultaneous or individually activated, has produced a variety of systems that have given rise to macrocycles and cages, as well as molecular motors and multicomponent architectures on surfaces. A given set of reactions can lead to systems with unique responsiveness, compositions, and functions as a result of the relative reactivities. In this Concept article, different molecular networks from synthetic systems that can be produced by combinations of different reaction types are discussed. Moreover, applications of this chemistry are highlighted, and future perspectives are envisioned.Fil: Orrillo, Alfredo Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Escalante, Andrea Marta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Martinez Amezaga, Maitena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Cabezudo, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Furlan, Ricardo Luis Eugenio. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

TipC and the chorea-acanthocytosis protein VPS13A regulate autophagy in Dictyostelium and human HeLa cells

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Autophagy on 01/01/2015, available online: https://doi.org/10.1080/15548627.2015.1034413.Deficient autophagy causes a distinct phenotype in Dictyostelium discoideum, characterized by the formation of multitips at the mound stage. This led us to analyze autophagy in a number of multitipped mutants described previously (tipA–, tipB–, tipC–, and tipD–). We found a clear autophagic dysfunction in tipC– and tipD– while the others showed no defects. tipD codes for a homolog of Atg16, which confirms the role of this protein in Dictyostelium autophagy and validates our approach. The tipC-encoded protein is highly similar to human VPS13A (also known as Chorein), whose mutations cause the chorea-acanthocytosis syndrome. No member of the VPS13 protein family has been previously related to autophagy despite the presence of a region of similarity to Atg2 at the C terminus. This region also contains the conserved domain of unknown function DUF1162. Of interest, the expression of the TipC C-terminal coding sequence containing these 2 motifs largely complemented the mutant phenotype. Dictyostelium cells lacking TipC displayed a reduced number of autophagosomes visualized with the markers GFP-Atg18 and GFP-Atg8 and an impaired autophagic degradation as determined by a proteolytic cleavage assay. Downregulation of human VPS13A in HeLa cells by RNA interference confirmed the participation of the human protein in autophagy. VPS13A-depleted cells showed accumulation of autophagic markers and impaired autophagic fluxThis work was supported by grants BFU2009-09050 and BFU2012-32536 from the Spanish Ministerio de Ciencia e Innovación. We also thank the help of Obra Social Caja de Burgos para Jóvenes Excelentes. SMB is recipient of a predoctoral fellowship from Universidad Autónoma de Madri

Evidence for an evolutionary relationship between Vmp1 and bacterial DedA proteins

VMP1 and DedA proteins are conserved families of transmembrane proteins in eukaryotes and prokaryotes respectively. Despite numerous reports involving these proteins in multiple cellular processes, their molecular function is still unknown. They share the domain of unknown function PF09335, suggesting a possible functional relationship between these protein families. Here we show that VMP1 from different species contain two short motifs conserved in the bacterial DedA proteins and the yeast protein Tvp38. The hallmark of one of these motifs is a glycine residue previously shown to be strictly conserved in all the DedA proteins. Substitution of this residue to leucine, glutamate or arginine in Dictyostelium Vmp1 inactivates the protein, as shown by the inability of the mutants to rescue the phenotypes associated with the lack of Vmp1 including development and lipid homeostasis. This is the first experimental approach that supports an evolutionary relationship between Vmp1 and DedA proteins and highlights the importance of the conserved glycine residue in the PF09335 domainThis work has been supported by MINECO/FEDER (grant number BFU2015-64440-P). LC is supported by a fellowship from the Spanish “Ministerio de Educación Cultura y Deporte”

Tiesiosios ir gaubtinės žarnos vėžys: ar įmanoma jo išvengti?

Colorectal cancer: is it possible to prevent it?Ricardo Escalant

Evaluación de la remoción bacteriana, en conductos radiculares irrigados con hipoclorito de sodio al 5.25%, usando dos sistemas de activación del irrigante: XP-Endo Finisher y Activación ultrasónica, in vivo.

INTRODUCCIÓN: La irrigación es una parte esencial del desbridamiento del conducto radicular porque permite la desinfección más allá de lo que puede ser logrado con la instrumentación por sí misma. OBJETIVOS: Evaluar la remoción bacteriana de XP-endo Finisher y Activación Ultrasónica, in vivo. METODOLOGÍA: Se trabajaron 30 conductos, ya sea Distal de molares inferiores o Palatino de molares superiores, se realizó anestesia y aislamiento, acceso, se tomó la primer muestra previo a instrumentar. Se instrumentó con V-Taper 2H y se irrigó con Hipoclorito de Sodio al 5.25%, se tomó segunda muestra después de instrumentar. Se activó el Hipoclorito de Sodio con técnicas mencionadas, y se tomó una tercer muestra. Estas muestras se incubaron durante 7 días. Se realizó conteo microscópico, después 10 diluciones por cada muestra y se sembró en Cajas de Petri con agar Infusión Cerebro Corazón. Se incubaron por 3 días y se realizó conteo macroscópico de UFC. RESULTADOS: No se observaron diferencias estadísticamente significativas entre la remoción bacteriana utilizando ambos coadyuvantes en la irrigación. CONCLUSIÓN: Ambos coadyuvantes poseen una alta eficacia para la remoción bacteriana posterior a la instrumentación. Abstract INTRODUCTION: Irrigation is an essential part of root canal debridement because it allows disinfection beyond what can be achieved with the instrumentation itself OBJECTIVES: Evaluate the bacterial removal of XP-endo Finisher and Activation Ultrasonic, in vivo. METHODOLOGY: Worked in 30 canals, either Distal of the lower molars or Palatine of the upper molars, anesthesia and isolation was performed, access, the first sample prior to an instrument was taken. It was instrumented with VTaper 2H and irrigated with 5.25% Sodium Hypochlorite, the second sample was taken after instrumentation. Sodium hypochlorite was activated with specific techniques, and a third sample was requested. These samples were incubated for 7 days. Microscopic counting was performed, after 10 dilutions for each sample and seeded in Petri plate with Heart Brain Infusion agar. They were incubated for 3 days and macroscopic UFC counts were performed. RESULTS: No statistically significant differences were observed between bacterial removal using both irrigation adjuvants. CONCLUSION: Both adjuvants are highly effective for bacterial removal after instrumentation

Aprendizaje de la historia desde una estrategia didáctica basada en la historia reciente

El trabajo titulado: "Aprendizaje de la historia desde una estrategia didáctica basada en la historia reciente", se realizó en La Institución educativa Nueva Esperanza, de Sincelejo Sucre, debido a una problemática que afectaba a la población estudiantil que consistía en algunas dificultades en el aprendizaje de algunas áreas del currículo, específicamente en la Historia, manifiestas en el desinterés hacia las actividades relacionadas con el aprendizaje de la historia, poco interés para cumplir con sus deberes educativos de las ciencias sociales. Se implementó una propuesta didáctica que buscaba mejorar la práctica de aula, dado que los docentes tendrán la oportunidad de seleccionar los contenidos de acuerdo con las necesidades del estudiante y aplicarlos según el contexto en el que viven, el interés y ritmos de aprendizaje de cada uno.The work entitled: "Learning history from a didactic strategy based on recent history", was carried out at the Nueva Esperanza educational institution, in Sincelejo Sucre, due to a problem that affected the student population that consisted of some difficulties in the learning of some areas of the curriculum, specifically in history, manifested in the disinterest in activities related to the learning of history, little interest in fulfilling their educational duties in the social sciences. A didactic proposal was implemented that sought to improve classroom practice, since teachers will have the opportunity to select the contents according to the student's needs and apply them according to the context in which they live, the interest and learning rhythms of each one

Structural and functional studies of a family of Dictyostelium discoideum developmentally regulated, prestalk genes coding for small proteins

Includes additional file: Structure and chromosomal location of Dictyostelium genes similar to sigN1. In this table the DictyBase database accession number, chromosomal location and exon/intron structure of the genes similar to sigN1 is indicated together with the size of the encoded proteins and their percentage of similarity to SigN1.[Background] The social amoeba Dictyostelium discoideum executes a multicellular development program upon starvation. This morphogenetic process requires the differential regulation of a large number of genes and is coordinated by extracellular signals. The MADS-box transcription factor SrfA is required for several stages of development, including slug migration and spore terminal differentiation.[Results] Subtractive hybridization allowed the isolation of a gene, sigN (SrfA-induced gene N), that was dependent on the transcription factor SrfA for expression at the slug stage of development. Homology searches detected the existence of a large family of sigN-related genes in the Dictyostelium discoideum genome. The 13 most similar genes are grouped in two regions of chromosome 2 and have been named Group1 and Group2 sigN genes. The putative encoded proteins are 87–89 amino acids long. All these genes have a similar structure, composed of a first exon containing a 13 nucleotides long open reading frame and a second exon comprising the remaining of the putative coding region. The expression of these genes is induced at10 hours of development. Analyses of their promoter regions indicate that these genes are expressed in the prestalk region of developing structures. The addition of antibodies raised against SigN Group 2 proteins induced disintegration of multi-cellular structures at the mound stage of development.[Conclusion] A large family of genes coding for small proteins has been identified in D. discoideum. Two groups of very similar genes from this family have been shown to be specifically expressed in prestalk cells during development. Functional studies using antibodies raised against Group 2 SigN proteins indicate that these genes could play a role during multicellular development.This work was supported by grants from the Spanish Ministerio de Educación y Ciencia, Dirección General de Investigación (BMC2002-01501 and BFU2005-00138).Peer reviewe