225 research outputs found

    An energy-saving model for service-oriented mobile application development

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    The development of mobile applications that combine Web Services from different providers --also referred as mashup applications-- is growing as a consequence of the ubiquity of bandwidth connections and the increasing number of available Web Services. In this context, providing higher maintainability to Web Service applications is a worth of matter, because of the dynamic nature of the Web. EasySOC (1) solves this problem by decoupling mashups from application components. However, mobile devices have energy constraints because of the limitations in the current battery capacities. This work proposes a model that builds on the benefits of the EasySOC approach and improves this latter by assisting developers to select Web Service combinations that reduce energy consumption. We evaluated the feasibility of the model through a case study in which we compare the estimations provided by the model against real energy measurements. The results indicated that our model had an efficacy of 81% for the analyzed case study.Sociedad Argentina de Informática e Investigación Operativa (SADIO

    Effects of beaver (Castor canadensis) on the nutrient dynamics of the Southern Beech forest of Tierra del Fuego (Argentina)

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    Las alteraciones provocadas por las actividades del castor (Castor canadensis) resultan un ejemplo claro de cómo los animales influencian el ecosistema forestal. Los castores modifican la morfología e hidrología de las cursos de agua por la remoción de árboles, construcción de diques y retención de sedimento y materia orgánica en la cuenca. Nosotros estudiamos el efecto de los endicamientos producidos por el castor sobre la dinámica de nutrientes del bosque de Nothofagus de Tierra del Fuego (Argentina) comparando sedimentos y agua de estanques de sitios alterados por castor y no alterados (controles) durante un periodo de 3 años. Las concentraciones de carbono, nitrógeno orgánico e inorgánico (N--nitrato y N--nitrito) y fósforo fueron significativamente mayores en los sedimentos de sitios alterados. Tambien las concentraciones de nitratos y nitritos fueron significativamente más altas en aguas de estanques de castor.Alterations induced by beaver (Castor canadensis) provide a striking example of how the animals influence forest ecosystems. Beavers modify stream morphology and hydrology by removing trees, building dams and retaining sediment and organic material in the stream channel. We studied the effect of beaver impoundments on nutrient dynamics of the native forest (Nothofagus sp.) of Isla Grande of Tierra del Fuego (Argentina), by comparing sediments and pond waters of beaver altered and unaltered sites (controls) over a 3 year period. Concentration of organic carbon, nitrogen, phosphorous, and inorganic nitrogen (nitrate --N and nitrite--N) were significantly greater in sediments of beaver sites. Also nitrites and nitrates were higher in beaver pond waters

    An energy-saving model for service-oriented mobile application development

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    The development of mobile applications that combine Web Services from different providers --also referred as mashup applications-- is growing as a consequence of the ubiquity of bandwidth connections and the increasing number of available Web Services. In this context, providing higher maintainability to Web Service applications is a worth of matter, because of the dynamic nature of the Web. EasySOC solves this problem by decoupling mashups from application components. However, mobile devices have energy constraints because of the limitations in the current battery capacities. This work proposes a model that builds on the benefits of the EasySOC approach and improves this latter by assisting developers to select Web Service combinations that reduce energy consumption. We evaluated the feasibility of the model through a case study in which we compare the estimations provided by the model against real energy measurements and two handsets. The results indicated that our model had an efficacy of 81-85% for the analyzed case study.Sociedad Argentina de Informática e Investigación Operativ

    Estimating oceanic turbulence dissipation from seismic images

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    Author Posting. © American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 30 (2013): 1767–1788, doi:10.1175/JTECH-D-12-00140.1.Seismic images of oceanic thermohaline finestructure record vertical displacements from internal waves and turbulence over large sections at unprecedented horizontal resolution. Where reflections follow isopycnals, their displacements can be used to estimate levels of turbulence dissipation, by applying the Klymak–Moum slope spectrum method. However, many issues must be considered when using seismic images for estimating turbulence dissipation, especially sources of random and harmonic noise. This study examines the utility of seismic images for estimating turbulence dissipation in the ocean, using synthetic modeling and data from two field surveys, from the South China Sea and the eastern Pacific Ocean, including the first comparison of turbulence estimates from seismic images and from vertical shear. Realistic synthetic models that mimic the spectral characteristics of internal waves and turbulence show that reflector slope spectra accurately reproduce isopycnal slope spectra out to horizontal wavenumbers of 0.04 cpm, corresponding to horizontal wavelengths of 25 m. Using seismic reflector slope spectra requires recognition and suppression of shot-generated harmonic noise and restriction of data to frequency bands with signal-to-noise ratios greater than about 4. Calculation of slope spectra directly from Fourier transforms of the seismic data is necessary to determine the suitability of a particular dataset to turbulence estimation from reflector slope spectra. Turbulence dissipation estimated from seismic reflector displacements compares well to those from 10-m shear determined by coincident expendable current profiler (XCP) data, demonstrating that seismic images can produce reliable estimates of turbulence dissipation in the ocean, provided that random noise is minimal and harmonic noise is removed.This work was funded by NSF Grants 0452744, 0405654, and 0648620, and ONR/DEPSCoR Grant DODONR40027.2014-02-0

    Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage

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    Author Posting. © The Authors, 2008. This is the author's version of the work. It is posted here by permission of American Association for the Advancement of Science for personal use, not for redistribution. The definitive version was published in Science 320 (2008): 778-781, doi:10.1126/science.1153360.Surface meltwater that reaches the base of an ice sheet creates a mechanism for the rapid response of ice flow to climate change. The process whereby such a pathway is created through thick, cold ice has not, however, been previously observed. We describe the rapid (<2 hours) drainage of a large supraglacial lake down 980 m through to the bed of the Greenland Ice Sheet initiated by water-driven fracture propagation evolving into moulin flow. Drainage coincided with increased seismicity, transient acceleration, ice sheet uplift and horizontal displacement. Subsidence and deceleration occurred over the following 24 hours. The short-lived dynamic response suggests an efficient drainage system dispersed the meltwater subglacially. The integrated effect of multiple lake drainages could explain the observed net regional summer ice speedup.Support was provided jointly by NSF and NASA through ARC-0520077 (S.B.D., M.P.B., I.M.H.) and ARC- 520382 (I.J.); The WHOI OCCI and Clark Arctic Research Initiative provided additional support to S.B.D., M.D.B., and D.L.; and a NERC (UK) Research Fellowship supported M.A.K

    Genetic characterization of Callosciurus (Rodentia: Sciuridae) Asiatic squirrels introduced in Argentina

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    Squirrels have been traded in the pet market for several decades, and numerous species have established in the wild. The Asiatic species Callosciurus erythraeus and Callosciurus finlaysonii have been introduced into other parts of Asia, in Europe and South America. In this study, (1) we conducted a genetic characterization of C. erythraeus introduced into Argentina and compared them with native and introduced populations in Asia, and (2) we analyzed genetic variation among the four invasion foci in Argentina in order to corroborate that the pathway of invasion was a single introduction event in the country and subsequent translocations. We analyzed mitochondrial (cytochrome b, Cyt b; cytochrome oxidase c subunit I, COI and D-loop) and nuclear (recombination activating gene I, RAGI) DNA markers using the classical method (DNA barcoding gap analysis) and also the Automatic Barcode Gap Discovery method (ABGD). The markers D-loop, COI, and RAG1 indicated that the introduced squirrels from the different invasion foci formed a monophyletic group that, together with only one haplotype for the D-loop and COI markers, supported the hypothesis of one introduction event into Argentina followed by subsequent translocations. Unexpectedly, sequences from squirrels captured in Argentina were more related to C. finlaysonii than to C. erythraeus for D-loop and Cyt b markers. However, intraspecific variation among sequences of C. erythraeus belonging to different subspecies or collected in different regions was large and comparable with the distance to the sequences from Argentina. The ABGD method also indicated large genetic variability within C. erythraeus and close proximity between squirrels from Argentina and C. finlaysonii. The complex taxonomy of Callosciurus, as occurs with the sister species C. erythraeus and C. finlaysonii, requires a thorough systematic revision. A simultaneous analysis of diagnostic morphological characters and genetic markers is needed and will provide new insight regarding the worldwide invasion of Asiatic squirrels.Centro Regional de Estudios Genómico

    La importancia de la relación empresa-universidad en la formación del alumno

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    Dentro del diseño de Grado de Ingeniería Informática de la universidad, se hace especial hincapié en proporcionar al alumno una experiencia profesional tutelada en empresa. Esto se desarrolla mediante la gestión del programa de alternancia estudio trabajo (AET) y el Trabajo Fin de grado (TFG) y tiene como objetivo mejorar la formación del alumno. Se describen los retos cuantitativos y cualitativos definidos, el método aplicado para alcanzarlos y los resultados obtenidos: todas las AET y TFG se realizan en empresa, y el alumno, la alumna1, ejecuta tareas afines a su especialidad, adquiriendo competencias técnicas, transversales y profesionales. Son 100% remunerados, reguladas a través de convenios con la universidad o contratos. Se incluyen indicadores de seguimiento como los porcentajes de alumnos participantes en programas de AET en Grado: 88% en 3º y 50% en 2º; la alta satisfacción de los alumnos, superior al 8/10 y las empresas, 9/10 en TFG; así como la relevancia de estas actividades en la empleabilidad, además de las aportaciones al proceso formativo más valoradas por los alumnos que participan en ellas.The Computer Science Engineering Degree includes an in-company training experience for students with professional assistance from university. Two programs address this initiative objective is the improvements of students integration in industry; the alternation work study program (AET) and the final year project (TFG). Both programs describes the quantitative and qualitative challenges, the methodology used to achieve these goals and the results obtained. The programs are conducted in companies where students perform tasks related to their expertise, acquiring technical, transversal and professional competences. The training programs are 100% remunerated and regulated through agreements and contracts with the university. This article describes those programs and includes the results after monitoring several indicators, such as the percentages of students participating in AET programs: 88% in 3rd grade and 50% in 2nd grade; the level of student satisfaction: above 8/10, and company satisfaction: 9/10 in AET and TFG; as well as the relevance of these activities in employability, and the most valued contributions to the training process most valued by the students

    Genetic characterization of Callosciurus (Rodentia: Sciuridae) Asiatic squirrels introduced in Argentina

    Get PDF
    Squirrels have been traded in the pet market for several decades, and numerous species have established in the wild. The Asiatic species Callosciurus erythraeus and Callosciurus finlaysonii have been introduced into other parts of Asia, in Europe and South America. In this study, (1) we conducted a genetic characterization of C. erythraeus introduced into Argentina and compared them with native and introduced populations in Asia, and (2) we analyzed genetic variation among the four invasion foci in Argentina in order to corroborate that the pathway of invasion was a single introduction event in the country and subsequent translocations. We analyzed mitochondrial (cytochrome b, Cyt b; cytochrome oxidase c subunit I, COI and D-loop) and nuclear (recombination activating gene I, RAGI) DNA markers using the classical method (DNA barcoding gap analysis) and also the Automatic Barcode Gap Discovery method (ABGD). The markers D-loop, COI, and RAG1 indicated that the introduced squirrels from the different invasion foci formed a monophyletic group that, together with only one haplotype for the D-loop and COI markers, supported the hypothesis of one introduction event into Argentina followed by subsequent translocations. Unexpectedly, sequences from squirrels captured in Argentina were more related to C. finlaysonii than to C. erythraeus for D-loop and Cyt b markers. However, intraspecific variation among sequences of C. erythraeus belonging to different subspecies or collected in different regions was large and comparable with the distance to the sequences from Argentina. The ABGD method also indicated large genetic variability within C. erythraeus and close proximity between squirrels from Argentina and C. finlaysonii. The complex taxonomy of Callosciurus, as occurs with the sister species C. erythraeus and C. finlaysonii, requires a thorough systematic revision. A simultaneous analysis of diagnostic morphological characters and genetic markers is needed and will provide new insight regarding the worldwide invasion of Asiatic squirrels.Centro Regional de Estudios Genómico

    Geomorphological characteristics of mountain watershed rivers colonized by Castor canadensis in Tierra del Fuego, Argentina

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    Se estudió la geomorfología de una cuenca de montaña de los Andes Fueguinos colonizada por Castor canadensis, con el objeto de detectar los aspectos físicos de los ríos ocupados por esta especie introducida. Se aplicaron métodos cartográficos, de análisis geomorfológico, de análisis morfométrico de cuencas y de seguimiento de la colonización a lo largo del tiempo. Estos últimos se realizaron en la totalidad de la cuenca mediante muestreos en el terreno, aerofotogramétricos y aéreos en época otoñal. Los cursos colonizados por Castor canadensis se distribuyen uniformemente en la cuenca con distinto tipo de ocupación y de continuidad espacial. Hubo una mayor frecuencia de selección de los ríos de primer y segundo orden, y con gradiente de 0-6º. Los ríos de mayor orden son ocupados en sus cauces secundarios y estacionalmente. La margen norte de la cuenca tiene mayor desarrollo areal, mayor densidad de drenaje, mayor número de cursos de agua y, por lo tanto, ofrece mayores posibilidades de ocupación. Los ríos que drenan las unidades geomorfológicas denominadas “valles colgantes laterales” presentan mayor ocupación espacial que los ríos que drenan las unidades “frentes de ladera”. Los parámetros de selección de hábitat determinados en este estudio resultan semejantes a los hallados para esta especie en el Hemisferio Norte.The geomorphology of a Fuegian Andes watershed colonized by the introduced species Castor canadensis has been analyzed. The main objective was to distinguish the physical conditions of the occupied streams. Geomorphological analysis and mapping techniques were applied; also, colonization monitoring surveys in the entire watershed was made through terrestrial and aerophotogrametrical methods. Were made aerial surveys during the autumn. Streams of first and second order and low gradient (0-6º) were those chosen by Castor canadensis for settlement. The higher-order streams were seasonally occupied, but restricted only to their secondary landforms. The northern part of the watershed is larger in size, drainage density and stream numbers; therefore, it offers more settlement possibilities. The rivers of the lateral hanging valleys were more densely occupied than those of the slope units. Several of the conditions of rivers for Castor canadensis settlement observed in Tierra del Fuego were similar to those observed in the Northern Hemisphere
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