2,730 research outputs found
The tadpole of Physalaemus fernandezae (Anura: Leptodactylidae)
This paper describes the external and buccopharyngeal morphology, chondrocranium and cranial muscles in tadpoles of Physalaemus fernandezae. The data are compared with those for other species of Physalaemus to improve the diagnosis of the “species group” within the genus. Species of the “P. biligonigerus” group have four infralabial papillae, two semicircular arches of pustulations in a V-shaped pattern on the prenarial arena, 6–8 conical papillae and 40–60 pustulations on the buccal roof arena, four postnarial papillae, a semicircular median ridge, clawshaped lateral ridges and larval crista parotica with a poorly-developed anterior process. Species of the “P. pustulosus” group possess four infralabial papillae (shared with the P. biligonigerus group), tooth row formula 2(2)/3, four lingual papillae, two postnarial papillae, twelve conical papillae and 16–20 pustulations on the buccal roof arena, short lateral ridges with rough concave margins and larval crista parotica with a well-developed anterior process and reduced posterior process. Species of the “P. cuvieri ” group present two infralabial papillae, three pustulations and two serrated papillae on the prenarial arena, five pustulations and two serrated papillae on the postnarial arena, four long and bifid papillae and more than 60 pustulations on the buccal roof arena, and lack larval crista parotica. In species of the “P. signiferus” group both medial and lateral mental gaps are absent, and the tooth row formula is 2(2)/3(1).Fil: Alcalde, Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Natale, Guillermo Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmosfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmosfera; ArgentinaFil: Cajade, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmosfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmosfera; Argentin
First report of Delphastus quinculus Gordon and Diomus seminulus (Mulsant) (Coleoptera: Coccinellidae) feeding on eggs and first-instar nymphs of Crypticerya multicicatrices Kondo and Unruh (Hemiptera: Monophlebidae)
Delphastus quinculus Gordon and Diomus seminulus (Mulsant) (Coleoptera: Coccinellidae) are reported for the first time feeding on eggs and first-instar nymphs of Crypticerya multicicatrices Kondo and Unruh (Hemiptera: Monophlebidae). Diagnosis and illustrations are provided for both species. Updated information on their biology, hosts and geographical distribution is also provided.Se reportan a Delphastus quinculus Gordon y Diomus seminulus (Mulsant) (Coleoptera: Coccinellidae) por primera vez como depredadores de huevos y ninfas del primer instar de Crypticerya multicicatrices Kondo and Unruh (Hemiptera: Monophlebidae). Las dos especies de coccinélidos se diagnostican y se ilustran en detalle. Se provee también información actualizada sobre sus biologías, hospederos y distribución geográfica
Computational design and designability of gene regulatory networks
Nuestro conocimiento de las interacciones moleculares nos ha conducido hoy hacia una perspectiva ingenieril, donde diseños e implementaciones de sistemas artificiales de regulación intentan proporcionar instrucciones fundamentales para la reprogramación celular. Nosotros aquí abordamos el diseño de redes de genes como una forma de profundizar en la comprensión de las regulaciones naturales. También abordamos el problema de la diseñabilidad dada una genoteca de elementos compatibles. Con este fin, aplicamos métodos heuríticos de optimización que implementan rutinas para resolver problemas inversos, así como herramientas de análisis matemático para estudiar la dinámica de la expresión genética. Debido a que la ingeniería de redes de transcripción se ha basado principalmente en el ensamblaje de unos pocos elementos regulatorios usando principios de diseño racional, desarrollamos un marco de diseño computacional para explotar este enfoque. Modelos asociados a genotecas fueron examinados para descubrir el espacio genotípico asociado a un cierto fenotipo. Además, desarrollamos un procedimiento completamente automatizado para diseñar moleculas de ARN no codificante con capacidad regulatoria, basándonos en un modelo fisicoquímico y aprovechando la regulación alostérica. Los circuitos de ARN resultantes implementaban un mecanismo de control post-transcripcional para la expresión de proteínas que podía ser combinado con elementos transcripcionales. También aplicamos los métodos heurísticos para analizar la diseñabilidad de rutas metabólicas. Ciertamente, los métodos de diseño computacional pueden al mismo tiempo aprender de los mecanismos naturales con el fin de explotar sus principios fundamentales. Así, los estudios de estos sistemas nos permiten profundizar en la ingeniería genética. De relevancia, el control integral y las regulaciones incoherentes son estrategias generales que los organismos emplean y que aquí analizamos.Rodrigo Tarrega, G. (2011). Computational design and designability of gene regulatory networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1417
Knowledge process outsourcing as a key for competitiveness of colombian biotechnological sector
Colombia, como país megadiverso, cuenta con importantes ventajas competitivas en el mercado global de materias primas e ingredientes naturales esenciales para un sinnúmero de actividades industriales. Sin embrago, las prácticas actuales relacionadas con la provisión de ingredientes naturales derivados de la biodiversidad ponen de presente las divergencias en cuanto al alcance de las normas sobre transferencia de tecnología contenidas en varios instrumentos multilaterales. El presente documento aborda el concepto de externalización de la gestión del conocimiento dentro del contexto de las políticas públicas orientadas al uso comercial de los recursos de la biodiversidad, indagando por las condiciones ideales que pueden favorecer la deslocalización de actividades de investigación y desarrollo por parte de corporaciones multinacionales respecto de la bioprospección e investigación fundamental, para que de esta manera los recursos de la biodiversidad puedan ser objeto de actividades de valor agregado dentro del territorio nacional.Colombia as a country with mega diversity has important competitiveness advantages in the global market of raw materials and essential natural ingredients for a larger number of industrial activities.However, current practices related to provision of natural ingredients derived from biodiversity show divergences in relation to the scope of norms on technology transfer written in several multilateral instruments.This document tackles the concept of knowledge management outsourcing within the context of public policies oriented to the commercial use of biodiversity resources, searching for ideal conditions which may favor delocalization of research and development activities for multinational corporations related to bio-prospection and basic research in such a way that biodiversity resources may be an object of aggregated value activities within the national territory.Na Colômbia como país muito diverso conta com importantes vantagens competitivas no mercado global de matérias-primas e ingredientes naturais essenciais para uma miríade de atividades industriais. No entanto, as práticas atuais relacionadas com o fornecimento de ingredientes naturais derivados da biodiversidade que apresentam diferenças no âmbito de aplicação das regras relativas à transferência de tecnologia contidas em vários instrumentos multilaterais. O presente documento, lida com o conceito de terceirização da gestão do conhecimento no contexto das políticas públicas que são direcionadas para a utilização comercial dos recursos da biodiversidade, procurando as condições ideais que podem favorecer a relocalização de atividades de investigação e desenvolvimento por empresas multinacionais como a bio-prospecção e a investigação de base, por isso, desta forma os recursos da biodiversidade podem ser objeto de atividades de valor agregado dentro do território nacional
Sphericals And Primitives Classes In The Bordism Of Compact Lie Groups
The main purpose of this thesis is to study the following question: Do primitives and sphericals agree in MU(,*)(X)/tor when X is a 1-connected compact Lie group. Our answers appear in Part IV for the classical groups (stable cases) and in Part V for two exceptional cases namely G(,2) and F(,4) (ignoring the prime 2).;The main tool for our study is the rational MU operation P : MU(,*)(X)(CRTIMES) (---\u3e) MU(,*)(X)(CRTIMES) ; P = (SIGMA)(,E) m(,E)S(,E) which detects primitives rationally. Our method is to find the least positive integer k(,(alpha)) (ELEM) such that k(,(alpha))P((alpha)) (ELEM) MU(,*)(X)/tor (L-HOOK) MU(,*)(X)(CRTIMES) for (alpha) (ELEM) MU(,*)(X)/tor. This is done in Part III (SECTION)1. In Part III (SECTION)2 and (SECTION)3, we calculate the primitive elements in MU(,*)((//C)P(\u27(INFIN))) and MU(,*)(HP(\u27(INFIN))) respectively. In (SECTION)4 we establish a relation between P and ch*:K*(X) (---\u3e) H**(X,Q) the Chern character, as well as between the integrality problem mentioned above and Chern character integrality condition
Policy implications of suboptimal choice: theory and evidence: misperceptions about tax audits
For some entities, such as self-employed individuals reporting income taxes or firms reporting value-added taxes, the optimal evasion rate depends substantially on audit features like audit probabilities and penalty rates (Allingham and Sandmo 1972). Whereas it is easy for firms to find other important information such as inflation rates or exchange rates, it is difficult to find information about the probability of being audited and penalty rates. Indeed, Bérgolo et al. (2017) show evidence that firms have large misperceptions about these audit features.1 In this paper, we expand their analysis to explore the sources of these misperceptions.Fil: Bérgolo, Marcelo. Universidad de la República; UruguayFil: Ceni, Rodrigo. Universidad de la República; UruguayFil: Cruces, Guillermo Antonio. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas. Centro de Estudios Distributivos Laborales y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Giaccobasso, Matias. University of California at Los Angeles; Estados UnidosFil: Perez Truglia, Ricardo. University of California at Los Angeles; Estados Unido
Describing the structural robustness landscape of bacterial small RNAs
<p>Abstract</p> <p>Background</p> <p>The potential role of RNA molecules as gene expression regulators has led to a new perspective on the intracellular control and genome organization. Because secondary structures are crucial for their regulatory role, we sought to investigate their robustness to mutations and environmental changes.</p> <p>Results</p> <p>Here, we dissected the structural robustness landscape of the small non-coding RNAs (sncRNAs) encoded in the genome of the bacterium <it>Escherichia coli</it>. We found that bacterial sncRNAs are not significantly robust to both mutational and environmental perturbations when compared against artificial, unbiased sequences. However, we found that, on average, bacterial sncRNAs tend to be significantly plastic, and that mutational and environmental robustness strongly correlate. We further found that, on average, epistasis in bacterial sncRNAs is significantly antagonistic, and positively correlates with plasticity. Moreover, the evolution of robustness is likely dependent upon the environmental stability of the cell, with more fluctuating environments leading to the emergence and fixation of more robust molecules. Mutational robustness also appears to be correlated with structural functionality and complexity.</p> <p>Conclusion</p> <p>Our study provides a deep characterization of the structural robustness landscape of bacterial sncRNAs, suggesting that evolvability could be evolved as a consequence of selection for more plastic molecules. It also supports that environmental fluctuations could promote mutational robustness. As a result, plasticity emerges to link robustness, functionality and evolvability.</p
Protein Repeats from First Principles
Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family.Fil: Turjanski, Pablo Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Parra, Rodrigo Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Espada, Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Becher, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Ferreiro, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentin
NEW PHOSPHORUS COMPOUNDS K[PCL3(X)] (X= SCN, CN): PREPARATION AND DFT AND SPECTROSCOPIC STUDIES
Indexación: Web of Science. Scielo.Two new phosphorus complexes, potassium trichlorothiocyanophosphate (III) (PTCTCP; K[PCl3(SCN)]) and potassium trichlorocyanophosphate (III) (PTCCP; K[PCl3(CN)]) were synthesized from the reaction of KSCN and KCN, respectively, with PC^. The chemical formulas and compositions of these compounds were determined by elemental analysis and spectroscopic methods, such as phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy (31P-NMR), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy and mass spectrophotometry. All of the theoretical calculations and determinations of the properties of these compounds were performed as part of the Amsterdam Density Functional (ADF) program. Excitation energies were assessed using time-dependent perturbation density functional theory (TD-DFT). In addition, the molecular geometry was optimized and the frequencies and excitation energies were calculated using standard Slater-type orbital (STO) basis sets with triple-zeta quality double plus polarization functions (TZ2P) for all of the atoms. The assignment of the principal transitions and total densities of state (TDOS) for orbital analysis were performed using the GaussSum 2.2 program.http://www.scielo.cl/pdf/jcchems/v61n1/art15.pd
Survey on Evaluation Methods for Dialogue Systems
In this paper we survey the methods and concepts developed for the evaluation
of dialogue systems. Evaluation is a crucial part during the development
process. Often, dialogue systems are evaluated by means of human evaluations
and questionnaires. However, this tends to be very cost and time intensive.
Thus, much work has been put into finding methods, which allow to reduce the
involvement of human labour. In this survey, we present the main concepts and
methods. For this, we differentiate between the various classes of dialogue
systems (task-oriented dialogue systems, conversational dialogue systems, and
question-answering dialogue systems). We cover each class by introducing the
main technologies developed for the dialogue systems and then by presenting the
evaluation methods regarding this class
- …