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Mameli Laura - One of the best experts on this subject based on the ideXlab platform.

  • La Gestión del recurso avifaunístico por las poblaciones canoeras del archipiélago fueguino
    Bellaterra : Universitat Autònoma de Barcelona, 2005
    Co-Authors: Mameli Laura
    Abstract:

    Consultable des del TDXTítol obtingut de la portada digitalitzadaEste trabajo arqueozoológico ha tenido el fin de conocer la gestión social del recurso aves por las poblaciones canoeras nómadas que habitaron el archipielago fueguino, en la Patagonia austral, desde hace unos 6000 años hasta el siglo XIX. Estos grupos humanos fueron cazadores recolectores pescadores y basaron su economía en la explotación de especies animales marinas y litorales; entre ellas se encuentran las aves, representadas en la región por unas 200 especies. Para conocer la variabilidad en la explotación del recurso tanto espacial como temporalmente se han seleccionado siete yacimientos arqueológicos emplazados en la costa norte del canal Beagle. La metodología para desarrollar esta investigación y poder hacer asunciones de índole social, se basó en el estudio integral de los restos de animales, discriminando tafonómicamente los aprovechados antrópicamente y cuantificando las porciones aprovechadas de manera diferencial. Ello implica estudios exahustivos de las superficies de los restos óseos a altos aumentos a la vez que complejos procedimientos de digitalización de las modificaciones antrópicas asociadas a diferentes actividades. En lo que se refiere a marcas antrópicas, a la vez que se establece su morfología microscópica de alta resolución, así como la variabilidad interna de las marcas, se ha prestado especial atención a la localización anatómica de las mismas, su agrupamiento, frecuencia de aparición, orientación, distribución y cantidad de cortes, trazas y raspados, asociando lo observado a actividades de procesamiento. Sólo mediante estos análisis es factible llegar a determinar los procesos de caza y captura, despellejamiento, procesamiento, consumo de alimentos, consumo de huesos, tendones, pieles, penachos, garras, vísceras, hasta llegar al descarte de las presas, así como su combustión e historia tafonómica una vez los restos en los depósitos. Es interés primordial del trabajo conocer si las aves y mamíferos marinos se explotaban esporádicamente de manera similar a lo largo del tiempo o si, por el contrario, existieron diferencias coyunturales o tendencias de cambios en su explotación entre diferentes momentos. A lo largo del trabajo se ha definido el rol que jugaron las diferentes clases animales en la dieta humana, a la vez que se identificaron patrones diferenciales en la gestión de las presas, interpretando las estrategias seguidas en cuanto a obtención, procesamiento, consumo y descarte de las especies. Los resultados obtenidos han permitido definir el proceso de aprovechamiento de las aves por parte de estos grupos de cazadores-recolectores-pescadores, la explotación diferencial de los recursos presentes en un entorno, el tratamiento de las presas, cómo se descuartizaban, procesaban y cocinaban, cómo se utilizaban sus huesos, que porciones de las presas eran desechadas y lo que implican estos procesos a nivel social. Más allá del consumo cárnico de los animales se ha identificado el aprovechamiento de materias primas como huesos, cueros, plumas, vísceras, cuernos, pelos, garras, para la confección de instrumentos y ornamentos. Otros aspectos que han podido investigarse están en relación con la estacionalidad de las ocupaciones humanas en la región y la reconstrucción paleoambiental y ecológica de los nichos estudiados entre el Holoceno medio y la actualidad. Ha sido posible obtener conocimiento acerca de cómo estos grupos humanos pudieron llevar una dieta equilibrada, sin la sobreexplotación de los recursos explotables, en un ambiente hostil y pobre en recursos vegetales consumibles a lo largo de los 6000 años de su existencia en la región, hasta que comienza la desintegración social, pudiendo analizar los cambios en la organización de la producción y en la explotación de los recursos antes, durante y después de la colonización europea de la región. En este sentido se analizaron las respuestas de estas sociedades ante puntos de inflexión de índole catastrófica de su realidad inmediata, en este caso la explotación masiva industrial de ballenas y focas (su principal alimento) por parte de empresas europeas y americanas. Esta Tesis Doctoral demuestra que análisis arqueozoológico de los restos animales de diversos yacimientos aporta información no sólo acerca de la manera en que se aprovecharon los recursos disponibles, sino acerca de las formas de subsistencia de esas mismas poblaciones, señalando momentos de creciente aumento en la obtención de la biomasa consumible, la incorporación en la dieta de nuevas especies quizás no rentables y no explotadas o explotadas en cantidad mínima en momentos de abundancia de alimentos de mayor rédito. La investigación enfatiza en los momentos de cambio, estudiando las causas y los efectos de las transformaciones sociales y económicas.This archaeozoological investigation intends to know the social management of birds by the nomadic populations of fishers, gatherers and hunters who inhabited the fueguian archipielago , in austral Patagonia, for about 6000 years to century XIX. These human groups based their economy on the capture of marine and coastal animals; among them are the birds. They are represented in the region by 200 species. In order to know the historical variability in the social management of this resource seven archaeological sites located in the North coast of the Beagle channel have been selected. The methodology adopted for this investigation to make assumptions of social nature, was based on the integral study of t animal archaeological remains, distinguishing the antropic and non-antropic deposits. Data were quantified. The analysis also implied an exhaustive study of the bone surface, using high and low resolution microscopy technologies, and proceeding to the computer digitalisation of observed wear traces. Special attention was paid to the morphology, internal variability, anatomical location, Frequency, Direction, intensity and distribution of marks produced on the surface as a result og human action. Only by means of these analyses is feasible to determine animal hunting and processing, distinguishing capture, skinning, butchery and food consumption, as well the consumption of bones, and other residues: skins, plumes, claws, guts, until arriving at the discard of the prey. Throughout the work the aim has been to establish the roles that different classes of animals played in human diet, and discover which patterns allow the identification of differences in the resource management, interpreting the strategies followed as far as obtaining, processing, consumption and discarding animal preys. It is fundamental interest of the work to know whether marine birds and mammals operated themselves sporadically throughout all the temporal span or, on the contrary, appear specific differences or tendencies of change in resource management between different moments. Obtained results have allowed the definition of the advantage birds offered to these groups of hunters-gatherers-fishermen. The differences in the management of existing resources in the immediate environment, the treatment of the preys, how they were butchered, processed and cooked, how their bones were used, which portions of the prey were rejected and what they imply these processes at a social level. Beyond the meat consumption of the animals the advantages of raw materials like bones has been identified, leathers, pens, guts, horns, hairs, claws, for the making of instruments and ornaments. Other aspects which have been investigated are in relation to the seasonality of human occupations in the region and the paleoenvironmental and ecological reconstruction of the niches studied between the Early Holocen and the present time. It has been possible to obtain knowledge about how these human groups got a balanced diet, without an overexploitation of the existing resources, in a hostile and poor environment lacking consumable vegetal resources throughout their 6000 years of history, until the social disintegration begins. This catastrophic finale is a consequence of European colonization of the region. The industrial massive exploitation of whales and seals (its main food) on the part of European and American companies generated a general food stress on local populations, and imposed changes in the organization of the production and the exploitation of resources. This Doctoral Thesis demonstrates that archaeozoological analysis of animal remains from diverse deposits contributes information not only about the way in which the available resources were exploited, but about the forms of subsistence of these populations, indicating moments of increasing volumes of consumable biomass, the incorporation to the diet of new resources, less profitable than other, and probably for that reason not consumed or perhaps consumed in minimum amount at moments of abundance of foods of greater yield. The investigation emphasizes the moments of social change, studying the causes and the effects of the social and economic transformations, using as material evidence the way the captured, processed and consumed coastal birds

  • La gestión del recurso avifaunístico por las poblaciones canoeras del archipielago fueguino
    'Universitat Autonoma de Barcelona', 2004
    Co-Authors: Mameli Laura
    Abstract:

    Este trabajo arqueozoológico ha tenido el fin de conocer la gestión social del recurso aves por las poblaciones canoeras nómadas que habitaron el archipielago fueguino, en la Patagonia austral, desde hace unos 6000 años hasta el siglo XIX. Estos grupos humanos fueron cazadores recolectores pescadores y basaron su economía en la explotación de especies animales marinas y litorales; entre ellas se encuentran las aves, representadas en la región por unas 200 especies. Para conocer la variabilidad en la explotación del recurso tanto espacial como temporalmente se han seleccionado siete yacimientos arqueológicos emplazados en la costa norte del canal Beagle. La metodología para desarrollar esta investigación y poder hacer asunciones de índole social, se basó en el estudio integral de los restos de animales, discriminando tafonómicamente los aprovechados antrópicamente y cuantificando las porciones aprovechadas de manera diferencial. Ello implica estudios exahustivos de las superficies de los restos óseos a altos aumentos a la vez que complejos procedimientos de digitalización de las modificaciones antrópicas asociadas a diferentes actividades. En lo que se refiere a marcas antrópicas, a la vez que se establece su morfología microscópica de alta resolución, así como la variabilidad interna de las marcas, se ha prestado especial atención a la localización anatómica de las mismas, su agrupamiento, frecuencia de aparición, orientación, distribución y cantidad de cortes, trazas y raspados, asociando lo observado a actividades de procesamiento. Sólo mediante estos análisis es factible llegar a determinar los procesos de caza y captura, despellejamiento, procesamiento, consumo de alimentos, consumo de huesos, tendones, pieles, penachos, garras, vísceras, hasta llegar al descarte de las presas, así como su combustión e historia tafonómica una vez los restos en los depósitos.Es interés primordial del trabajo conocer si las aves y mamíferos marinos se explotaban esporádicamente de manera similar a lo largo del tiempo o si, por el contrario, existieron diferencias coyunturales o tendencias de cambios en su explotación entre diferentes momentos. A lo largo del trabajo se ha definido el rol que jugaron las diferentes clases animales en la dieta humana, a la vez que se identificaron patrones diferenciales en la gestión de las presas, interpretando las estrategias seguidas en cuanto a obtención, procesamiento, consumo y descarte de las especies.Los resultados obtenidos han permitido definir el proceso de aprovechamiento de las aves por parte de estos grupos de cazadores-recolectores-pescadores, la explotación diferencial de los recursos presentes en un entorno, el tratamiento de las presas, cómo se descuartizaban, procesaban y cocinaban, cómo se utilizaban sus huesos, que porciones de las presas eran desechadas y lo que implican estos procesos a nivel social. Más allá del consumo cárnico de los animales se ha identificado el aprovechamiento de materias primas como huesos, cueros, plumas, vísceras, cuernos, pelos, garras, para la confección de instrumentos y ornamentos. Otros aspectos que han podido investigarse están en relación con la estacionalidad de las ocupaciones humanas en la región y la reconstrucción paleoambiental y ecológica de los nichos estudiados entre el Holoceno medio y la actualidad.Ha sido posible obtener conocimiento acerca de cómo estos grupos humanos pudieron llevar una dieta equilibrada, sin la sobreexplotación de los recursos explotables, en un ambiente hostil y pobre en recursos vegetales consumibles a lo largo de los 6000 años de su existencia en la región, hasta que comienza la desintegración social, pudiendo analizar los cambios en la organización de la producción y en la explotación de los recursos antes, durante y después de la colonización europea de la región. En este sentido se analizaron las respuestas de estas sociedades ante puntos de inflexión de índole catastrófica de su realidad inmediata, en este caso la explotación masiva industrial de ballenas y focas (su principal alimento) por parte de empresas europeas y americanas.Esta Tesis Doctoral demuestra que análisis arqueozoológico de los restos animales de diversos yacimientos aporta información no sólo acerca de la manera en que se aprovecharon los recursos disponibles, sino acerca de las formas de subsistencia de esas mismas poblaciones, señalando momentos de creciente aumento en la obtención de la biomasa consumible, la incorporación en la dieta de nuevas especies quizás no rentables y no explotadas o explotadas en cantidad mínima en momentos de abundancia de alimentos de mayor rédito. La investigación enfatiza en los momentos de cambio, estudiando las causas y los efectos de las transformaciones sociales y económicas.This archaeozoological investigation intends to know the social management of birds by the nomadic populations of fishers, gatherers and hunters who inhabited the fueguian archipielago , in austral Patagonia, for about 6000 years to century XIX. These human groups based their economy on the capture of marine and coastal animals; among them are the birds. They are represented in the region by 200 species. In order to know the historical variability in the social management of this resource seven archaeological sites located in the North coast of the Beagle channel have been selected.The methodology adopted for this investigation to make assumptions of social nature, was based on the integral study of t animal archaeological remains, distinguishing the antropic and non-antropic deposits. Data were quantified. The analysis also implied an exhaustive study of the bone surface, using high and low resolution microscopy technologies, and proceeding to the computer digitalisation of observed wear traces. Special attention was paid to the morphology, internal variability, anatomical location, Frequency, Direction, intensity and distribution of marks produced on the surface as a result og human action. Only by means of these analyses is feasible to determine animal hunting and processing, distinguishing capture, skinning, butchery and food consumption, as well the consumption of bones, and other residues: skins, plumes, claws, guts, until arriving at the discard of the prey.Throughout the work the aim has been to establish the roles that different classes of animals played in human diet, and discover which patterns allow the identification of differences in the resource management, interpreting the strategies followed as far as obtaining, processing, consumption and discarding animal preys.It is fundamental interest of the work to know whether marine birds and mammals operated themselves sporadically throughout all the temporal span or, on the contrary, appear specific differences or tendencies of change in resource management between different moments.Obtained results have allowed the definition of the advantage birds offered to these groups of hunters-gatherers-fishermen. The differences in the management of existing resources in the immediate environment, the treatment of the preys, how they were butchered, processed and cooked, how their bones were used, which portions of the prey were rejected and what they imply these processes at a social level. Beyond the meat consumption of the animals the advantages of raw materials like bones has been identified, leathers, pens, guts, horns, hairs, claws, for the making of instruments and ornaments. Other aspects which have been investigated are in relation to the seasonality of human occupations in the region and the paleoenvironmental and ecological reconstruction of the niches studied between the Early Holocen and the present time.It has been possible to obtain knowledge about how these human groups got a balanced diet, without an overexploitation of the existing resources, in a hostile and poor environment lacking consumable vegetal resources throughout their 6000 years of history, until the social disintegration begins. This catastrophic finale is a consequence of European colonization of the region. The industrial massive exploitation of whales and seals (its main food) on the part of European and American companies generated a general food stress on local populations, and imposed changes in the organization of the production and the exploitation of resources.This Doctoral Thesis demonstrates that archaeozoological analysis of animal remains from diverse deposits contributes information not only about the way in which the available resources were exploited, but about the forms of subsistence of these populations, indicating moments of increasing volumes of consumable biomass, the incorporation to the diet of new resources, less profitable than other, and probably for that reason not consumed or perhaps consumed in minimum amount at moments of abundance of foods of greater yield. The investigation emphasizes the moments of social change, studying the causes and the effects of the social and economic transformations, using as material evidence the way the captured, processed and consumed coastal birds

M Hatef - One of the best experts on this subject based on the ideXlab platform.

  • the first power spectrum limit on the 21 cm signal of neutral hydrogen during the cosmic dawn at z 20 25 from lofar
    Monthly Notices of the Royal Astronomical Society, 2019
    Co-Authors: B K Gehlot, Florent Mertens, L V E Koopmans, M A Brentjens, Saleem Zaroubi, B Ciardi, Abhik Ghosh, M Hatef
    Abstract:

    Observations of the redshifted 21-cm hyperfine line of neutral hydrogen from early phases of the Universe such as Cosmic Dawn and the Epoch of Reionization promise to open a new window onto the early formation of stars and galaxies. We present the first upper limits on the power spectrum of redshifted 21-cm brightness temperature fluctuations in the redshift range z = 19.8-25.2 (54-68 MHz Frequency range) using 14 h of data obtained with the LOFAR-Low Band Antenna (LBA) array. We also demonstrate the application of a multiple pointing calibration technique to calibrate the LOFAR-LBA dual-pointing observations centred on the North Celestial Pole and the radio galaxy 3C220.3, We observe an unexplained excess of similar to 30-50 per cent in Stokes / noise compared to Stokes V for the two observed fields, which decorrelates on greater than or similar to 12 s and might have a physical origin. We show that enforcing smoothness of gain errors along Frequency Direction during calibration reduces the additional variance in Stokes I compared Stokes V introduced by the calibration on sub-band level. After subtraction of smooth foregrounds, we achieve a 2 sigma upper limit on the 21-cm power spectrum of Delta(2)(21) <(14561 mK)(2) at k similar to 0.038 h cMpc(-1) and Delta(2)(21) <(14886 mK)(2) at k 0.038 h cMpc(-1) for the 3C220 and NCP fields respectively and both upper limits are consistent with each other. The upper limits for the two fields are still dominated by systematics on most k modes.

Gerhard Bauch - One of the best experts on this subject based on the ideXlab platform.

  • differential modulation and cyclic delay diversity in orthogonal Frequency division multiplex
    IEEE Transactions on Communications, 2006
    Co-Authors: Gerhard Bauch
    Abstract:

    We propose a new scheme for differential modulation in orthogonal Frequency-division multiplexing (OFDM) with cyclic delay diversity. Delay diversity is done in a cyclic manner in order not to exceed the guard interval. However, the increased Frequency selectivity, and consequently, reduced coherence bandwidth, causes problems for noncoherent detection of differential modulation in Frequency Direction. Our proposal is able to cope with the increased Frequency selectivity,and enables picking up the spatial diversity in Frequency-selective channels with unknown delay spread in combination with standard differential modulation techniques. The new scheme is less complex than differential unitary space-time modulation. The overhead due to reference symbols is minimized and the detection delay is reduced, compared with differential modulation in time Direction.

  • multistream differential modulation for cyclic delay diversity in ofdm
    International Conference on Communications, 2004
    Co-Authors: Gerhard Bauch
    Abstract:

    A cyclic delay diversity in OFDM with noncoherent detection is considered. Delay diversity is done in a cyclic manner in order not to exceed the guard interval. We give a robust design criterion for the cyclic delay which enables to pick up the full spatial diversity in Frequency selective channels with unknown delay spread. However, the effective channel coefficients of neighbouring subcarriers appear to be uncorrelated which makes differential modulation in Frequency Direction impossible. Therefore, we propose a multistream scheme which allows to noncoherently exploit the full spatial diversity in combination with standard differential modulation techniques. The new scheme is less complex than differential unitary space-time modulation. The overhead due to reference symbols is minimized and the detection delay is reduced compared to differential modulation in time Direction.

Lenny R Vartanian - One of the best experts on this subject based on the ideXlab platform.

  • the impact of appearance comparisons made through social media traditional media and in person in women s everyday lives
    Body Image, 2017
    Co-Authors: Jasmine Fardouly, Rebecca T Pinkus, Lenny R Vartanian
    Abstract:

    Abstract Appearance comparisons are an important sociocultural factor influencing women’s body image. These comparisons can occur in different contexts (e.g., through magazines, social media, in person). However, little is known about the Frequency and outcome of appearance comparisons made in different contexts in women’s everyday lives. Using Ecological Momentary Assessment methods, female undergraduate students ( n  = 146) completed a brief online survey at random times every day for 5 days. They reported the Frequency, Direction (upward, lateral, downward), and context of appearance comparisons, and also reported their appearance satisfaction, mood, and diet and exercise thoughts and behaviors. Upward appearance comparisons were the most common across all contexts. Upward comparisons through social media were associated with more negative outcomes on all measures (except diet and exercise behavior) than comparisons made in person, and with more negative mood than comparisons in any other context. These findings highlight the importance of the appearance comparison context.

Huerta Antonio - One of the best experts on this subject based on the ideXlab platform.

  • Fast solution of elliptic harbor agitation problems under Frequency-Direction input spectra by model order reduction and NURBS-enhanced FEM
    'Elsevier BV', 2020
    Co-Authors: Modesto Galende David, Zlotnik Sergio, Ye Boyi, Huerta Antonio
    Abstract:

    © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Many harbor applications are based on the solution of linear elliptic agitation problems for many spectral conditions. One of the main goals consists in computing the linear combination of numerous simulations of the harbor agitation problem, using monochromatic waves of different spectral components (i.e. Frequency and incoming wave Direction). In practice, the standard strategy selects the number of wave components according to a prescribed discretization of the 2D input spectra. The main issue relies on some quantities of interest that are very sensitive to the level of refinement of the spectra, such as the significant wave height at every mesh point or the identification of resonance modes induced by long wave scattering. In many cases, achieving enough quality in these quantities may impose numerous simulations and, consequently, non-practical computer costs. This can drastically limit the final accuracy of results. To overcome this situation, here a new strategy is proposed to efficiently solve a large number of harbor agitation problems derived from dense discretizations of the 2D input spectra. The strategy is based on the combination of two different numerical approaches. Firstly, each required monochromatic simulation is solved via high order NURBS (non-uniform rational B-splines) enhanced finite elements (NEFEM). More precisely, NEFEM captures the exact harbor geometry using large mesh elements that produce accurate solutions and significant savings on the system size, particularly in long wave cases. Secondly, a model order reduction technique is used to approximate the original elliptic harbor model by a so-called surrogate model. The main advantage is that, once the surrogate model is constructed, it can be rapidly evaluated to provide simulations for any value of the spectral components within a range of interest, and without the need of solving any new harbor agitation problem (as the standard strategy does). Thus, this enables the possibility of using any desired discretization of the 2D input spectra with no additional computer cost. The construction of the surrogate model is performed using the proper generalized decomposition method with a novel incremental computation along the Frequency dimension. The proposed strategy is discussed, and its superior performance with respect to standard strategies is demonstrated, on two harbor agitation examples with several applications.Peer ReviewedPostprint (author's final draft

  • Fast solution of elliptic harbor agitation problems under Frequency-Direction input spectra by model order reduction and NURBS-enhanced FEM
    2020
    Co-Authors: Modesto D., Ye B., Zlotnik Sergio, Huerta Antonio
    Abstract:

    Many harbor applications are based on the solution of linear elliptic agitation problems for many spectral conditions. One of the main goals consists in computing the linear combination of numerous simulations of the harbor agitation problem, using monochromatic waves of different spectral components (i.e. Frequency and incoming wave Direction). In practice, the standard strategy selects the number of wave components according to a prescribed discretization of the 2D input spectra. The main issue relies on some quantities of interest that are very sensitive to the level of refinement of the spectra, such as the significant wave height at every mesh point or the identification of resonance modes induced by long wave scattering. In many cases, achieving enough quality in these quantities may impose numerous simulations and, consequently, non-practical computer costs. This can drastically limit the final accuracy of results. To overcome this situation, here a new strategy is proposed to efficiently solve a large number of harbor agitation problems derived from dense discretizations of the 2D input spectra. The strategy is based on the combination of two different numerical approaches. Firstly, each required monochromatic simulation is solved via high order NURBS (non-uniform rational B-splines) enhanced finite elements (NEFEM). More precisely, NEFEM captures the exact harbor geometry using large mesh elements that produce accurate solutions and significant savings on the system size, particularly in long wave cases. Secondly, a model order reduction technique is used to approximate the original elliptic harbor model by a so-called surrogate model. The main advantage is that, once the surrogate model is constructed, it can be rapidly evaluated to provide simulations for any value of the spectral components within a range of interest, and without the need of solving any new harbor agitation problem (as the standard strategy does). Thus, this enables the possibility of using any desired discretization of the 2D input spectra with no additional computer cost. The construction of the surrogate model is performed using the proper generalized decomposition method with a novel incremental computation along the Frequency dimension. The proposed strategy is discussed, and its superior performance with respect to standard strategies is demonstrated, on two harbor agitation examples with several applications