65 research outputs found

    Online regenerator placement.

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    Connections between nodes in optical networks are realized by lightpaths. Due to the decay of the signal, a regenerator has to be placed on every lightpath after at most d hops, for some given positive integer d. A regenerator can serve only one lightpath. The placement of regenerators has become an active area of research during recent years, and various optimization problems have been studied. The first such problem is the Regeneration Location Problem (Rlp), where the goal is to place the regenerators so as to minimize the total number of nodes containing them. We consider two extreme cases of online Rlp regarding the value of d and the number k of regenerators that can be used in any single node. (1) d is arbitrary and k unbounded. In this case a feasible solution always exists. We show an O(log|X| ·logd)-competitive randomized algorithm for any network topology, where X is the set of paths of length d. The algorithm can be made deterministic in some cases. We show a deterministic lower bound of W([(log(|E|/d) ·logd)/(log(log(|E|/d) ·logd))])log(Ed)logdlog(log(Ed)logd) , where E is the edge set. (2) d = 2 and k = 1. In this case there is not necessarily a solution for a given input. We distinguish between feasible inputs (for which there is a solution) and infeasible ones. In the latter case, the objective is to satisfy the maximum number of lightpaths. For a path topology we show a lower bound of Öl/2l2 for the competitive ratio (where l is the number of internal nodes of the longest lightpath) on infeasible inputs, and a tight bound of 3 for the competitive ratio on feasible inputs

    Diagnóstico y diseño de un sistema de gestión de calidad ISO 21001:2018 para la mejora de la calidad de la educación según el modelo SINEACE en la Facultad de Ingeniería Pesquera y de Alimentos de la UNAC

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    El presente trabajo de investigación tiene por objetivo diseñar un sistema de gestión de la calidad (SGC-FIPA) utilizando la norma ISO 21001, que permite mejorar la calidad educativa de la Facultad de Ingeniería Pesquera y de Alimentos (FIPA) y de esta manera satisfacer las necesidades y expectativas de las partes interesadas. El tipo de investigación es descriptivo; heurístico inductivo; con diseño bibliográfico de carácter explicativo cualitativo, cuantitativo y transversal, y aplicando método hipotético-deductivo. este estudio desarrolla las etapas de diagnóstico, planeación y diseño de un sistema de gestión de calidad una vez aprobado estas fases recién se puede ejecutar las otras fases que necesita un trabajo integral de los Profesores y demás partes interesadas. El diagnostico tuvo por finalidad evaluar el estado actual de la gestión educativa considerando la documentación existente, la satisfacción de los alumnos, la participación de los profesores, la planeación consistió en verificar el cumplimiento de la norma ISO 21001, la población utilizada para la investigación fueron los docentes directivos, personales administrativos y los estudiantes de las dos escuelas profesionales de la Facultad de Ingeniería Pesquera y de Alimentos. Para la recolección de datos se utilizó como técnica la encuesta, observación y entrevista teniendo en cuenta los puntos de la estructura obligatoria de la norma. Los resultados mostraron los siguientes cumplimientos: contexto de la organización, 14.77 %; liderazgo 41.38%; planificación 19.32%; soporte 41,67 %; Operación 46,68 %; evaluación del desempeño 28,47 %; y mejora. 0.0% %. de acuerdo a los resultados obtenidos se procedió a diseñar los documentos el manual de gestión de calidad, caracterización, los procedimientos, los registros, los formatos que sustentan los propósitos de cada punto con la finalidad de optimizar los procesos todos al 100% y los tiempos que involucran la Gestión Docente, así también la mejora continua de los mismos. Como resultados se obtuvieron: los procedimientos, indicadores de los procedimientos, caracterización de los procesos y registros de los procesos que constituyen la información documentada al 100 % del diseño de gestión de calidad para la FIPA, de buenas prácticas con mejora continua. Con la cual se cumplió los objetivos propuestos de esta investigación que se orienta a presentar el diseño sistema de gestión de calidad ISO 21001, una orientación a los principios de calidad, para posteriormente implementar y obtener a la certificación. Concluyendo que Los resultados de esta investigación nos permiten contar con un diseño de Sistema de Gestión de la Facultad de Ingeniería Pesquera y de Alimentos (SGCFIPA) aplicando la norma ISO 21001:2018 para mejora de la calidad educativa en la FIPA

    Uso de prebióticos como promotores del crecimiento en el cultivo de alevines de truchas Arco Iris (Oncorhynchus Mykiss)

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    El presente estudio tiene como objetivo determinar el efecto de la adición de una mezcla de ácidos orgánicos (MAO) sobre la ganancia de peso, tasa de crecimiento, factor de conversión alimentaria, coeficiente térmico de crecimiento, en los cultivos de truchas El experimento se basó en 4 tratamientos con 4 porcentajes de MAO ( T1= 0%, T2=0,5%, T3=1,0%, y T4= 1,5% de MAO) con 3 repeticiones cada tratamiento, haciendo un total de 12 unidades experimentales , La densidad de peces se mantuvo en 20 peces por cada tratamiento, el caudal de agua en la entrada de cada tanque fue de 300 L/h, la temperatura del agua se mantuvo de 16,5 a 17,0 ºC; el pH de 7,03 a 7,85; el amonio de 0,01 a 0,02 mg/L; los nitritos de 0,11 a 0,2 mg, y se les alimentó al inicio con una tasa alimentaria del 10% del peso corporal por día finalizando con un 4% / día. Se midieron el peso y la talla cada 15 días durante 90 días, obteniéndose los siguientes resultados de pesos finales; T1= 50.23 ± 5.44, T2 = 53.29 ±7.13 T3 = 75.12 ± 7.38 T4 = 68.12 ±6.12 gramos respectivamente encontrándose diferencia significativa (P<0,05) de mayor peso final entre el T 3 ( 1.0% MAO)) y el T1 (0% MAO), .La conversión alimentaria mostró diferencia significativa (p<0,05) entre el tratamiento T3 mejor que el tratamiento T1 (1,12). Los tratamientos T 2 y T4 no mostraron diferencia significativa, pero si un menor valor que el T 3. El coeficiente térmico de crecimiento también el tratamiento T3 fue mejor que los demás tratamientos. Después de los 90 días se procedió a predecir el crecimiento de peso cada 15 días hasta los 150 días con un modelo teórico de predicción del crecimiento (coeficiente térmico de crecimiento :CTC) es cual demostró que este modelo se adecua muy bien ya que mantuvo la misma tendencia de los valores prácticos obteniéndose al final los siguientes resultados de pesos finales; T1=189,45 g, T2 = 201,76±10,56 T3 = 215,87±9,23 T4 =198,41±10,20 gramos es decir que los valores guardan relación en su crecimiento: Concluyéndose que para lograr mejores parámetros productivos en el cultivo de truchas los ácidos orgánicos constituyen un buen promotor de crecimiento.Trabado de investigacio

    T-RFPred: a nucleotide sequence size prediction tool for microbial community description based on terminal-restriction fragment length polymorphism chromatograms

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    <p>Abstract</p> <p>Background</p> <p>Terminal-Restriction Fragment Length Polymorphism (T-RFLP) is a technique used to analyze complex microbial communities. It allows for the quantification of unique or numerically dominant phylotypes in amplicon pools and it has been used primarily for comparisons between different communities. T-RFPred, Terminal-Restriction Fragment Prediction, was developed to identify and assign taxonomic information to chromatogram peaks of a T-RFLP fingerprint for a more comprehensive description of microbial communities. The program estimates the expected fragment size of representative 16S rRNA gene sequences (either from a complementary clone library or from public databases) for a given primer and restriction enzyme(s) and provides candidate taxonomic assignments.</p> <p>Results</p> <p>To show the accuracy of the program, T-RFLP profiles of a marine bacterial community were described using artificial bacterioplankton clone libraries of sequences obtained from public databases. For all valid chromatogram peaks, a phylogenetic group could be assigned.</p> <p>Conclusions</p> <p>T-RFPred offers enhanced functionality of T-RFLP profile analysis over current available programs. In particular, it circumvents the need for full-length 16S rRNA gene sequences during taxonomic assignments of T-RF peaks. Thus, large 16S rRNA gene datasets from environmental studies, including metagenomes, or public databases can be used as the reference set. Furthermore, T-RFPred is useful in experimental design for the selection of primers as well as the type and number of restriction enzymes that will yield informative chromatograms from natural microbial communities.</p

    La metáfora desde la perspectiva de la pragmática

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    La metáfora supone una alteración de los principios sistematizados y codificados de la lengua. Seguramente, cualquiera de nosotros podría suscribir, sin demasiadas objeciones, la afirmación anterior. En consecuencia, puede resultar interesante acercarse a ella desde una teoría que incluya, justifique y explique, entre sus presuposiciones y argumentos, la significación e intención de tales alteraciones. La teoría pragmática, que se centra en el uso que los hablantes hacen de la lengua, nos brinda la posibilidad de observar este fenómeno tropológico desde una perspectiva suficientemente amplia

    Recurrent patterns of microdiversity in a temperate coastal marine environment

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    © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in The ISME Journal 12 (2018): 237–252, doi:10.1038/ismej.2017.165.Temperate coastal marine environments are replete with complex biotic and abiotic interactions that are amplified during spring and summer phytoplankton blooms. During these events, heterotrophic bacterioplankton respond to successional releases of dissolved organic matter as algal cells are lysed. Annual seasonal shifts in the community composition of free-living bacterioplankton follow broadly predictable patterns, but whether similar communities respond each year to bloom disturbance events remains unknown owing to a lack of data sets, employing high-frequency sampling over multiple years. We capture the fine-scale microdiversity of these events with weekly sampling using a high-resolution method to discriminate 16S ribosomal RNA gene amplicons that are >99% identical. Furthermore, we used 2 complete years of data to facilitate identification of recurrent sub-networks of co-varying microbes. We demonstrate that despite inter-annual variation in phytoplankton blooms and despite the dynamism of a coastal–oceanic transition zone, patterns of microdiversity are recurrent during both bloom and non-bloom conditions. Sub-networks of co-occurring microbes identified reveal that correlation structures between community members appear quite stable in a seasonally driven response to oligotrophic and eutrophic conditions.PLB is supported by the European Research Council Advanced Investigator grant ABYSS 294757 to Antje Boetius. AF-G is supported by the European Union’s Horizon 2020 research and innovation program (Blue Growth: Unlocking the potential of Seas and Oceans) under grant agreement no. (634486) (project acronym INMARE). This study was funded by the Max Planck Society. Further support by the Department of Energy Joint Genome Institute (CSP COGITO) and DFG (FOR2406) is acknowledged by HT (TE 813/2-1) and RA (Am 73/9-1)

    A New Southern North Atlantic Isochron Map: Insights Into the Drift of the Iberian Plate Since the Late Cretaceous

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    This paper presents a new southern North Atlantic plate model from Late Cretaceous to present, with the aim of constraining the kinematics of the Iberian plate during the last 83.5 Myr. This model is presented along with a detailed isochron map generated through the analysis of 3 aeromagnetic tracks and ~400 ship tracks from the National Centers for Environmental Information database. We present a new technique to obtain well‐constrained estimates of the Iberia‐North America plate motions from magnetic anomalies, overcoming the scarcity of large‐offset fracture zones and transform faults. We build an integrated kinematic model for NW Africa, Morocco, Iberia, Europe, and North America, which shows that the deformation is partitioned between Pyrenees and Betic‐Rif orogenic domain during the Late Cretaceous‐Oligocene time interval. In the Eastern Betics domain, the calculated amount of NW Africa‐Iberia convergence is ~80 km between 83.5 and 34 Ma, followed by ~150 km since the Oligocene. The motion of Iberia relative to Europe in the Central Pyrenees is characterized by overall NE directed transpressional motion during the Campanian and the Paleocene, followed by NW directed transpressional movement until the Lutetian and overall NNW directed convergence from Bartonian to Chattian. This motion occurs along the axis of the Bay of Biscay from the Santonian–Campanian boundary to the middle Priabonian, subsequently jumping to King's Trough at Anomaly 17 (36.62 Ma)

    Genomic adaptation of giant viruses in polar oceans

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    寒冷域と温暖域ではウイルスの遺伝子組成が異なる --巨大ウイルスの環境適応--. 京都大学プレスリリース. 2023-10-13.Despite being perennially frigid, polar oceans form an ecosystem hosting high and unique biodiversity. Various organisms show different adaptive strategies in this habitat, but how viruses adapt to this environment is largely unknown. Viruses of phyla Nucleocytoviricota and Mirusviricota are groups of eukaryote-infecting large and giant DNA viruses with genomes encoding a variety of functions. Here, by leveraging the Global Ocean Eukaryotic Viral database, we investigate the biogeography and functional repertoire of these viruses at a global scale. We first confirm the existence of an ecological barrier that clearly separates polar and nonpolar viral communities, and then demonstrate that temperature drives dramatic changes in the virus–host network at the polar–nonpolar boundary. Ancestral niche reconstruction suggests that adaptation of these viruses to polar conditions has occurred repeatedly over the course of evolution, with polar-adapted viruses in the modern ocean being scattered across their phylogeny. Numerous viral genes are specifically associated with polar adaptation, although most of their homologues are not identified as polar-adaptive genes in eukaryotes. These results suggest that giant viruses adapt to cold environments by changing their functional repertoire, and this viral evolutionary strategy is distinct from the polar adaptation strategy of their hosts

    Autophagy-mediated NCOR1 degradation is required for brown fat maturation and thermogenesis

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    Brown adipose tissue (BAT) thermogenesis affects energy balance, and thereby it has the potential to induce weight loss and to prevent obesity. Here, we document a macroautophagic/autophagic-dependent mechanism of peroxisome proliferator-activated receptor gamma (PPARG) activity regulation that induces brown adipose differentiation and thermogenesis and that is mediated by TP53INP2. Disruption of TP53INP2-dependent autophagy reduced brown adipogenesis in cultured cells. In vivo specific-tp53inp2 ablation in brown precursor cells or in adult mice decreased the expression of thermogenic and mature adipocyte genes in BAT. As a result, TP53INP2-deficient mice had reduced UCP1 content in BAT and impaired maximal thermogenic capacity, leading to lipid accumulation and to positive energy balance. Mechanistically, TP53INP2 stimulates PPARG activity and adipogenesis in brown adipose cells by promoting the autophagic degradation of NCOR1, a PPARG co-repressor. Moreover, the modulation of TP53INP2 expression in BAT and in human brown adipocytes suggests that this protein increases PPARG activity during metabolic activation of brown fat. In all, we have identified a novel molecular explanation for the contribution of autophagy to BAT energy metabolism that could facilitate the design of therapeutic strategies against obesity and its metabolic complications

    Microbes with higher metabolic independence are enriched in human gut microbiomes under stress

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    A wide variety of human diseases are associated with loss of microbial diversity in the human gut, inspiring a great interest in the diagnostic or therapeutic potential of the microbiota. However, the ecological forces that drive diversity reduction in disease states remain unclear, rendering it difficult to ascertain the role of the microbiota in disease emergence or severity. One hypothesis to explain this phenomenon is that microbial diversity is diminished as disease states select for microbial populations that are more fit to survive environmental stress caused by inflammation or other host factors. Here, we tested this hypothesis on a large scale, by developing a software framework to quantify the enrichment of microbial metabolisms in complex metagenomes as a function of microbial diversity. We applied this framework to over 400 gut metagenomes from individuals who are healthy or diagnosed with inflammatory bowel disease (IBD). We found that high metabolic independence (HMI) is a distinguishing characteristic of microbial communities associated with individuals diagnosed with IBD. A classifier we trained using the normalized copy numbers of 33 HMI-associated metabolic modules not only distinguished states of health versus IBD, but also tracked the recovery of the gut microbiome following antibiotic treatment, suggesting that HMI is a hallmark of microbial communities in stressed gut environments
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