141 research outputs found
MODELLING OF COLLECTIVE MOVEMENT IN IMMERSIVE ENVIRONMENTS
Immersive technologies allow us to map physical reality by means of 4D virtual systems in ever higher spatial and temporal detail, up to a scale level of 1 : 1. This level of detail enables the representation of phenomena that have been widely ignored by the geovisualization research agenda as yet. An example for such a large scale phenomenon is the collective movement of animals, which can be modelled and visualized only at a fine grained spatio-temporal resolution. This paper focuses on how collective movement can be modelled in an immersive virtual reality (VR) geovisualization. In a brief introduction on immersion and spatial presence we will argue, that high fidelity and realistic VR can strengthen the users’ involvement with the issues visualized. We will then discuss basic characteristics of swarming in nature and review the principal models that have been presented to formalize this collective behavior. Based on the rules of (1) collision avoidance, (2) polarization, (3) aggregation and (4) self-organized criticality we will formulate a viable solution of modelling collective movement within a geovisualization immersive virtual environment. An example of use and results will be presented
VALORACIÓN PROFESIONAL DEL ANÁLISIS CRÍTICO SOBRE LA COMPETENCIA EDITORIAL DE LA POLÍTICA CIENTÍFICA DIVULGATIVA
La responsabilidad sobre la lectura, comprensión y comunicación científica resulta un proceso complejo donde se requiere capacitación previa y consolidada antes del posible desempeño como editor científico. El propósito del estudio fue valorar de forma profesional el análisis crítico sobre la competencia editorial de la política científica divulgativa. Se seleccionó de forma aleatoria, diezinvestigadores y se les aplicó, una evaluación que consistió en siete preguntas con base en capacitaciones previas a su desempeño: 1ro) metodología de la investigación con enfoque cualimétrico, 2do) comprensión de la comunicación científica, 3ro) gestión y vigilancia informativa, 4to) operación de programas digitales para la gestión editorial, 5to) maquetación editorial, 6to) proceso de arbitraje y 7mo) estrategias para la competencia responsable en la aceptación y edición científica. A cada pregunta fue asignada una puntuación siendo seleccionada la Revista Científica: The Biologist (Lima). Para aceptar cómo válida la competencia editorial sobre la política científica divulgativa se estableció una prueba de hipótesis con criterio de 90 puntos (media hipotética). Se aceptó la H1 (la formación para el desempeño editorial de la política científica divulgativa de los investigadores es competente), pues al comparar la tcal (-6,98) con la ttab (1,833), la misma fue menor siendo corroborada con el valor p (0,000) < ,005. Se concluyó que, fue aceptada la valoración profesional realizada por los investigadores ante el análisis crítico sobre la competencia editorial de la política científica divulgativa para la revista The Biologist (Lima)
Measuring the Polarization of a Rapidly Precessing Deuteron Beam
This paper describes a time-marking system that enables a measurement of the
in-plane (horizontal) polarization of a 0.97-GeV/c deuteron beam circulating in
the Cooler Synchrotron (COSY) at the Forschungszentrum J\"ulich. The clock time
of each polarimeter event is used to unfold the 120-kHz spin precession and
assign events to bins according to the direction of the horizontal
polarization. After accumulation for one or more seconds, the down-up
scattering asymmetry can be calculated for each direction and matched to a
sinusoidal function whose magnitude is proportional to the horizontal
polarization. This requires prior knowledge of the spin tune or polarization
precession rate. An initial estimate is refined by re-sorting the events as the
spin tune is adjusted across a narrow range and searching for the maximum
polarization magnitude. The result is biased toward polarization values that
are too large, in part because of statistical fluctuations but also because
sinusoidal fits to even random data will produce sizeable magnitudes when the
phase is left free to vary. An analysis procedure is described that matches the
time dependence of the horizontal polarization to templates based on
emittance-driven polarization loss while correcting for the positive bias. This
information will be used to study ways to extend the horizontal polarization
lifetime by correcting spin tune spread using ring sextupole fields and thereby
to support the feasibility of searching for an intrinsic electric dipole moment
using polarized beams in a storage ring. This paper is a combined effort of the
Storage Ring EDM Collaboration and the JEDI Collaboration.Comment: 28 pages, 15 figures, prepared for Physical Review ST - Accelerators
and Beam
HERMENÉUTICA DE LA OBSERVACIÓN MEDIANTE EVALUACIONES ESCRITAS PARA EL PLANTEAMIENTO DEL PROBLEMA DE INVESTIGACIÓN Y LA FORMULACIÓN AL PROBLEMA CIENTÍFICO
El propósito del estudio fue la hermenéutica de la observación mediante evaluaciones escritas para el planteamiento del problema de investigación y la formulación al problema científico. El estudio se realizó durante febrero y marzo del 2020 en la Universidad Nacional ¨San Luis Gonzaga¨ Ica, Perú. Se aplicó, 15 preguntas escritas a los docentes con referencias a los módulos: 1ro) investigación científica con enfoque cualimétrico y producción intelectual, y 2do) gnoseología y epistemología: argumentos en la investigación científica. Mediante un muestreo probabilístico aleatorio se seleccionó, 10 resultados individuales calificándose de 13 puntos como valor mínimo y 20 puntos el valor máximo donde 15 puntos fue el promedio que se alcanzó. En el contraste de hipótesis, el valor de t tabulado fue -2,262 siendo menor a la t calculada (-7,67) rechazándose la hipótesis nula que, no hay dificultad en el reconocimiento del problema de investigación y el problema científico (µ≥17). El error en el planteamiento del problema de investigación fue de 60% mientras que, el 38% fue para la formulación al problema científico. Las principales razones de análisis fueron: 1ro) la no sistematicidad (objeto de investigación), 2do) examen no crítico (heurística) y; 3ro) las pocas verificaciones (comprobación de hipótesis). Finalmente, las evaluaciones escritas indicaron la inconsecuente descripción del objeto de investigación y su influencia negativa para el planteamiento del problema de investigación y la formulación al problema científico
Kernicterus by glucose-6-phosphate dehydrogenase deficiency: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive disease that causes acute or chronic hemolytic anemia and potentially leads to severe jaundice in response to oxidative agents. This deficiency is the most common human innate error of metabolism, affecting more than 400 million people worldwide.</p> <p>Case presentation</p> <p>Here, we present the first documented case of kernicterus in Panama, in a glucose-6-phosphate dehydrogenase-deficient newborn clothed in naphthalene-impregnated garments, resulting in reduced psychomotor development, neurosensory hypoacousia, absence of speech and poor reflex of the pupil to light.</p> <p>Conclusion</p> <p>Mutational analysis revealed the glucose-6-phosphate dehydrogenase Mediterranean polymorphic variant, which explained the development of kernicterus after exposition of naphthalene. As the use of naphthalene in stored clothes is a common practice, glucose-6-phosphate dehydrogenase testing in neonatal screening could prevent severe clinical consequences.</p
Ibero-American Society of Interventionism (SIDI) and the Spanish Society of Vascular and Interventional Radiology (SERVEI) Standard of Practice (SOP) for the management of inferior Vena Cava filters in the treatment of acute venous Thromboembolism
Objectives: to present an interventional radiology standard of practice on the use of inferior vena cava filters (IVCFs) in patients with or at risk to develop venous thromboembolism (VTE) from the Iberoamerican Interventional Society (SIDI) and Spanish Vascular and Interventional Radiology Society (SERVEI). Methods: a group of twenty-two interventional radiologist experts, from the SIDI and SERVEI societies, attended online meetings to develop a current clinical practice guideline on the proper indication for the placement and retrieval of IVCFs. A broad review was undertaken to determine the participation of interventional radiologists in the current guidelines and a consensus on inferior vena cava filters. Twenty-two experts from both societies worked on a common draft and received a questionnaire where they had to assess, for IVCF placement, the absolute, relative, and prophylactic indications. The experts voted on the different indications and reasoned their decision. Results: a total of two-hundred-thirty-three articles were reviewed. Interventional radiologists participated in the development of just two of the eight guidelines. The threshold for inclusion was 100% agreement. Three absolute and four relative indications for the IVCF placement were identified. No indications for the prophylactic filter placement reached the threshold. Conclusion: interventional radiologists are highly involved in the management of IVCFs but have limited participation in the development of multidisciplinary clinical practice guidelines
Lysine acetyltransferase Tip60 is required for hematopoietic stem cell maintenance.
Hematopoietic stem cells (HSCs) have the potential to replenish the blood system for the lifetime of the organism. Their 2 defining properties, self-renewal and differentiation, are tightly regulated by the epigenetic machineries. Using conditional gene-knockout models, we demonstrated a critical requirement of lysine acetyltransferase 5 (Kat5, also known as Tip60) for murine HSC maintenance in both the embryonic and adult stages, which depends on its acetyltransferase activity. Genome-wide chromatin and transcriptome profiling in murine hematopoietic stem and progenitor cells revealed that Tip60 colocalizes with c-Myc and that Tip60 deletion suppress the expression of Myc target genes, which are associated with critical biological processes for HSC maintenance, cell cycling, and DNA repair. Notably, acetylated H2A.Z (acH2A.Z) was enriched at the Tip60-bound active chromatin, and Tip60 deletion induced a robust reduction in the acH2A.Z/H2A.Z ratio. These results uncover a critical epigenetic regulatory layer for HSC maintenance, at least in part through Tip60-dependent H2A.Z acetylation to activate Myc target genes.Cancer Research UK, Wellcome Trust, National Institutes of Health, Singapore state fundin
Uncovering the Prevalence and Diversity of Integrating Conjugative Elements in Actinobacteria
Horizontal gene transfer greatly facilitates rapid genetic adaptation of bacteria to shifts in environmental conditions and colonization of new niches by allowing one-step acquisition of novel functions. Conjugation is a major mechanism of horizontal gene transfer mediated by conjugative plasmids and integrating conjugative elements (ICEs). While in most bacterial conjugative systems DNA translocation requires the assembly of a complex type IV secretion system (T4SS), in Actinobacteria a single DNA FtsK/SpoIIIE-like translocation protein is required. To date, the role and diversity of ICEs in Actinobacteria have received little attention. Putative ICEs were searched for in 275 genomes of Actinobacteria using HMM-profiles of proteins involved in ICE maintenance and transfer. These exhaustive analyses revealed 144 putative FtsK/SpoIIIE-type ICEs and 17 putative T4SS-type ICEs. Grouping of the ICEs based on the phylogenetic analyses of maintenance and transfer proteins revealed extensive exchanges between different sub-families of ICEs. 17 ICEs were found in Actinobacteria from the genus Frankia, globally important nitrogen-fixing microorganisms that establish root nodule symbioses with actinorhizal plants. Structural analysis of ICEs from Frankia revealed their unexpected diversity and a vast array of predicted adaptive functions. Frankia ICEs were found to excise by site-specific recombination from their host's chromosome in vitro and in planta suggesting that they are functional mobile elements whether Frankiae live as soil saprophytes or plant endosymbionts. Phylogenetic analyses of proteins involved in ICEs maintenance and transfer suggests that active exchange between ICEs cargo-borne and chromosomal genes took place within the Actinomycetales order. Functionality of Frankia ICEs in vitro as well as in planta lets us anticipate that conjugation and ICEs could allow the development of genetic manipulation tools for this challenging microorganism and for many other Actinobacteria
High Content Phenotypic Cell-Based Visual Screen Identifies Mycobacterium tuberculosis Acyltrehalose-Containing Glycolipids Involved in Phagosome Remodeling
The ability of the tubercle bacillus to arrest phagosome maturation is considered one major mechanism that allows its survival within host macrophages. To identify mycobacterial genes involved in this process, we developed a high throughput phenotypic cell-based assay enabling individual sub-cellular analysis of over 11,000 Mycobacterium tuberculosis mutants. This very stringent assay makes use of fluorescent staining for intracellular acidic compartments, and automated confocal microscopy to quantitatively determine the intracellular localization of M. tuberculosis. We characterised the ten mutants that traffic most frequently into acidified compartments early after phagocytosis, suggesting that they had lost their ability to arrest phagosomal maturation. Molecular analysis of these mutants revealed mainly disruptions in genes involved in cell envelope biogenesis (fadD28), the ESX-1 secretion system (espL/Rv3880), molybdopterin biosynthesis (moaC1 and moaD1), as well as in genes from a novel locus, Rv1503c-Rv1506c. Most interestingly, the mutants in Rv1503c and Rv1506c were perturbed in the biosynthesis of acyltrehalose-containing glycolipids. Our results suggest that such glycolipids indeed play a critical role in the early intracellular fate of the tubercle bacillus. The unbiased approach developed here can be easily adapted for functional genomics study of intracellular pathogens, together with focused discovery of new anti-microbials
Non Mycobacterial Virulence Genes in the Genome of the Emerging Pathogen Mycobacterium abscessus
Mycobacterium abscessus is an emerging rapidly growing mycobacterium (RGM) causing a pseudotuberculous lung disease to which patients with cystic fibrosis (CF) are particularly susceptible. We report here its complete genome sequence. The genome of M. abscessus (CIP 104536T) consists of a 5,067,172-bp circular chromosome including 4920 predicted coding sequences (CDS), an 81-kb full-length prophage and 5 IS elements, and a 23-kb mercury resistance plasmid almost identical to pMM23 from Mycobacterium marinum. The chromosome encodes many virulence proteins and virulence protein families absent or present in only small numbers in the model RGM species Mycobacterium smegmatis. Many of these proteins are encoded by genes belonging to a “mycobacterial” gene pool (e.g. PE and PPE proteins, MCE and YrbE proteins, lipoprotein LpqH precursors). However, many others (e.g. phospholipase C, MgtC, MsrA, ABC Fe(3+) transporter) appear to have been horizontally acquired from distantly related environmental bacteria with a high G+C content, mostly actinobacteria (e.g. Rhodococcus sp., Streptomyces sp.) and pseudomonads. We also identified several metabolic regions acquired from actinobacteria and pseudomonads (relating to phenazine biosynthesis, homogentisate catabolism, phenylacetic acid degradation, DNA degradation) not present in the M. smegmatis genome. Many of the “non mycobacterial” factors detected in M. abscessus are also present in two of the pathogens most frequently isolated from CF patients, Pseudomonas aeruginosa and Burkholderia cepacia. This study elucidates the genetic basis of the unique pathogenicity of M. abscessus among RGM, and raises the question of similar mechanisms of pathogenicity shared by unrelated organisms in CF patients
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