5,066 research outputs found
Comparing MapReduce and pipeline implementations for counting triangles
A common method to define a parallel solution for a computational problem consists in finding a way to use the Divide and Conquer paradigm in order to have processors acting on its own data and scheduled in a parallel fashion. MapReduce is a programming model that follows this paradigm, and allows for the definition of efficient solutions by both decomposing a problem into steps on subsets of the input data and combining the results of each step to produce final results. Albeit used for the implementation of a wide variety of computational problems, MapReduce performance can be negatively affected whenever the replication factor grows or the size of the input is larger than the resources available at each processor. In this paper we show an alternative approach to implement the Divide and Conquer paradigm, named dynamic pipeline. The main features of dynamic pipelines are illustrated on a parallel implementation of the well-known problem of counting triangles in a graph. This problem is especially interesting either when the input graph does not fit in memory or is dynamically generated. To evaluate the properties of pipeline, a dynamic pipeline of processes and an ad-hoc version of MapReduce are implemented in the language Go, exploiting its ability to deal with channels and spawned processes. An empirical evaluation is conducted on graphs of different topologies, sizes, and densities. Observed results suggest that dynamic pipelines allows for an efficient implementation of the problem of counting triangles in a graph, particularly, in dense and large graphs, drastically reducing the execution time with respect to the MapReduce implementation.Peer ReviewedPostprint (published version
Inhalable spray-dried chondroitin sulphate microparticles: effect of different solvents on particle properties and drug activity
Spray-drying stands as one of the most used techniques to produce inhalable microparticles, but several parameters from both the process and the used materials affect the properties of the resulting microparticles. In this work, we describe the production of drug-loaded chondroitin sulphate microparticles by spray-drying, testing the effect of using different solvents during the process. Full characterisation of the polymer and of the aerodynamic properties of the obtained microparticles are provided envisaging an application in inhalable tuberculosis therapy. The spray-dried microparticles successfully associated two first-line antitubercular drugs (isoniazid and rifabutin) with satisfactory production yield (up to 85%) and drug association efficiency (60%-95%). Ethanol and HCl were tested as co-solvents to aid the solubilisation of rifabutin and microparticles produced with the former generally revealed the best features, presenting a better ability to sustainably release rifabutin. Moreover, these presented aerodynamic properties compatible with deep lung deposition, with an aerodynamic diameter around 4 μm and fine particle fraction of approximately 44%. Finally, it was further demonstrated that the antitubercular activity of the drugs remained unchanged after encapsulation independently of the used solvent.UID/Multi/04326/2019; SFRH/BD/52426/2013; ED481B 2018/071info:eu-repo/semantics/publishedVersio
Espécies exóticas invasoras marinhas da ilha de Santa Maria, Açores
XIV Expedição Científica do Departamento de Biologia - Santa Maria 2009.No âmbito da XIV Expedição Científica à ilha de Santa Maria 2009, organizada pelo
Departamento de Biologia da Universidade dos Açores, realizaram-se várias prospecções,
com recurso a mergulho com escafandro autónomo, com o objectivo de identificar espécies marinhas exóticas (macroalgas e macroinvertebrados) na marina e porto comercial da Ilha de Santa Maria e áreas adjacentes. Identificaram-se 9 espécies exóticas, das quais 4 são consideradas como invasoras um pouco por todo o mundo: as algas Asparagopsis armata e Codium fragile, e as ascídeas Clavelina lepadiformis e Distaplia corolla. Para além disso,
efectuou-se uma avaliação preliminar do tráfego de recreio, verificando-se um aumento do mesmo desde 2007 até Junho de 2009, principalmente a nível local
Identification of Barriers Towards Change and Proposal to Institutionalize Continuous Improvement Programs in Manufacturing Operations
A multi case research unfolded into a study in a sample of Brazilian manufacturing companies concerning their Continuous Improvement (CI) program in manufacturing operations. Stakeholders interviews and performance analyses were conducted. The study aims to analyze the existence or absence of the institutionalization of a CI culture in manufacturing operations, identify barriers and difficulties within the process and propose a model for change. As a result of the research, it was observed that despite the considerable motivation of staff, rapid gains of the company and superior results during the early phases of the CI program, time and again such results were either not upheld or faded out over time, delivering no significant mid-term or long term results, due to poor management of changes. This happened mainly as a result of lack of strategic alignment at all levels of the organization, translated in measureable activities and projects, coached and mentored by the middle and upper management throughout the implementation and maintenance of the program. The selected cases showed a declining in performance after two years of CI program start up. Learning, union and process ownership among participants by means of interactions, are necessary to absorb and incorporate changes, instead of merely "smart words"
Search of extended or delayed TeV emission from GRBs with HAWC
Gamma-ray bursts (GRBs) are among the most luminous sources in the universe
and the nature of their emission up to very high energy is one of the most
important open issue connected with the study of these peculiar events. The
High Altitude Water Cherenkov (HAWC) gamma-ray observatory, installed at an
altitude of 4100 m a. s. l. in the state of Puebla (Mexico), has completed its
second year of full operations. Thanks to its instantaneous field of view of ~2
sr and its high duty cycle ( 95%), HAWC is an ideal instrument for the
study of transient phenomena such as GRBs. We performed a search for TeV
emission delayed with respect to, and of longer duration than the prompt
emission observed by satellites. We present here the results obtained by
observing at the position of a sample of GRBs detected by the Fermi and Swift
satellites from December 2014 to February 2017. The upper limits resulting from
this analysis are presented and theoretical implications are discussed.Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017),
Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution
O hipertexto na cultura contemporânea: do fim da linearidade à abertura conceptual
numa aproximação semiótica, estuda-se, neste capítulo, de que modo as novas formas de
produção e difusão de conhecimento realizadas a partir da reconfiguração do espaço influenciaram uma
mudança de paradigma no pensamento contemporâneo, apontando uma nova realidade nos sistemas
discursivos. Faz-se abordagem às noções de intertextualidade, hipertextualidade e ciberespaço, bem como
aos conceitos de descentramento, rizoma, derivação, não-linearidade (Kristeva, Derrida, Landow, Deleuze
e guattari, nelson ou genette), explicitando a relação entre intertextualidade e hipertextualidade (e hipertexto
electrónico), sobretudo no que concerne as formulações de discurso na cultura contemporânea
MapReduce vs. pipelining counting triangles
In this paper we follow an alternative approach named pipeline, to implement a parallel implementation of the well-known problem of counting triangles in a graph. This problem is especially interesting either when the input graph does not fit in memory or is dynamically generated. To be concrete, we implement a dynamic pipeline of processes and an ad-hoc MapReduce version using the language Go. We explote the ability of Go language to deal with channels and spawned processes. An empirical evaluation is conducted on graphs of different size and density. Observed results suggest that pipeline allows for the implementation of an efficient solution of the problem of counting triangles in a graph, particularly, in dense and large graphs, drastically reducing the execution time with respect to the MapReduce implementation.Peer ReviewedPostprint (published version
Senegalese sole (Solea senegalensis) ISG15: molecular characterization and in vivo interplay with viral infections
The interferon-stimulated gene 15 (Isg15) is strongly induced by type I interferon (IFN I), viral infection, and double-stranded RNA (poly I:C) in several fish species, suggesting that Isg15 protein could play a key role in fish innate immunity against viral diseases. Thus, the aim of the present study was to characterize the molecular structure and transcription pattern of the Senegalese sole (Solea senegalensis) Isg15 gene in response to viral infections.
The molecular characterization shows that the Senegalese sole Isg15 gene codes for a typical Isg15 protein of 165 aa, containing two ubiquitin-like domains and one conserved LRLRGG conjugating motif at the C-terminal end. The untranslated 5´-end region exhibited the structure of an IFN-stimulated gene promoter, with two interferon stimulated response elements (ISRE). Pairwise alignments based on deduced amino acid sequences showed homologous relationships (72.5-74.2%) between the Isg15 of Senegalese sole and other pleuronectiforms.
The Isg15 transcription has been studied in head kidneys of Senegalese sole inoculated with poly I:C and with different fish viruses: two Viral Haemorrhagic Septicaemia Virus (VHSV) isolates (highly pathogenic and non-pathogenic to sole), and one reassortant Viral Nervous Necrosis Virus (VNNV) isolate, composed of a RGNNV-type RNA1 and a SJNNV-type RNA2 (pathogenic to sole). These challenges showed that poly I:C induces Isg15 transcription from 3 to 72 h post-injection (p.i.), whereas the induction in response to viral infections started at 24-48 h p.i. The fast induction of Isg15 indicates the potential implication of this ISG in the antiviral state stablished by the IFN I system. On the other hand, the interaction between each virus and the IFN I system was evaluated in fish inoculated with poly I:C and subsequently (24 h later) challenged with the different viruses. This challenge showed a viral multiplication decrease in poly I:C treated animals compared with untreated fish. Besides, results showed that only both pathogenic isolates interfered negatively with the Isg15 stimulation triggered by poly I:C. These results suggest that the Isg15 might play an important role in host defense against RNA virus infection, and the pathogenic isolates used in this study may have mechanisms to evade or limit the Senegalese sole innate host defenses.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Efectividad de un programa educativo en el cuidado de quimioterapia del paciente oncológico de un hospital, Lima, 2023
La presente investigación tuvo como objetivo demostrar que el programa educativo
mejora el cuidado de quimioterapia del paciente oncológico de un hospital de Lima,
2023. La metodología utilizada en el estudio fue tipo aplicada, enfoque cuantitativo,
diseño experimental, corte longitudinal, diseño específico pre experimental, y la
muestra estuvo compuesta por 25 familiares de pacientes oncológicos a los que se
les aplicó un pre test para evaluar el conocimiento que tenían antes de empezar el
programa educativo, posteriormente se llevó a cabo las sesiones del programa
educativo y una vez terminadas estas se aplicó un post test para evaluar la
evolución de sus conocimientos. Los resultados obtenidos en el pretest revelaron
que el nivel de conocimiento fue en un 44% bajo y un 56% regular, mientras que en
el post test se evidenció una mejora con conocimientos 88% altos y 12% regulares.
Finalmente, obtuvo una media de 8,7600 entre el pretest y el postest y un p – valor
de 0.000 (p-valor<0.05) lo que hizo concluir que el programa educativo fue
significativamente efectivo en la mejora del cuidado de quimioterapia del paciente
oncológico de un hospital de Lima, 2023
Actividad proteolítica y antiproteolítica durante la maduración folicular en la cabra
Se disecaron y clasificaron folículos antrales de cabra, inicialmente por tamaño en tres grupos: menares de 3, entre 3 y 6 y mayores de 6 mm. Los folículos menores de 3mm. de diámetro fueron estudiados sin ningún otro tipo de clasificación. Todos los demás folículos se clasificaron en 4 grupos de acuerdo al grado de atresia que evidenciaron al microscopio estereoscópico. Las observaciones histológicas mostraron que en el grupo 1 se incluyeron a los folículos no atrésicos, en el grupo 2 a folículos en estadios tempranos de atresia y los grupos 3a y 3b se formaron por los folículos con atrésia secundarla y terciaria respectivamente. Las actividades de tripsina y antitripsina fueron medidas en líquido folicular, en homogeneizados de células de la granulosa y en sacos foliculares vacíos, usando para ambas actividades un procedimiento fluorométrico. La actividad antitripsina, se caracterizó parcialmente desde el punto de vlsta físico-químico, se calculó por cromatografía en gel su peso molecular, el cual fue aproximadamente de 64,000 daltones y para el caso de la actividad tríptica de 24,000 daltones aproximadamente. Se observó que la actividad antitrípsica en el líquido folicular está directamente relacionada con el proceso de atresia ne inversamente con el diámetro folicular; la actividad fue muy baja en los folículos grandes no atrésicos y consistentemente alta en los folículos pequeños de menos de 3 mm y en los folículos atrisicos. No se encontraron diferencias entre los folículos de los grupos 3a y 3b en los diferentes tamaños. Después de la eliminación por filtración en gel de la actividad antitriptica, la actividad de tripsina de las células libres en el líquido folicular sólo estuvo presente en los folículos no atrésicos mayores de 6 mm. Se encontró una alta actividad be tripsina en las células del saco de los folículos con atresia temprana. Esta actividad fue significativamente menor en los foliculos del grupo 3a y estuvo cas1 ausente en los folículos con atresia terciaria (grupo 3b). Por el contrario, la actividad de tripsina de las células de la granulosa recuperadas por centrifugación del líquido folicular, fué dos veces más alta en el grupo: a que en los grupo i y 2 y casi cinco veces más alta que la del grupo 3b. Otro importante hallazgo en este trabajo fué el haber encontrado que la concentración de hemoglobina es un importante parámetro para medir la atresia folicular de la cabra
- …