3,026 research outputs found

    LOCATION STRATEGIES BASED ON DISCRETE CHOICE MODELS: AN EMPIRICAL APPLICATION TO SUPERMARKET LOCATION

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    In this paper we present a theoretic two-stage model for retailers location and consumers purchase decision. Retailers decision problem is formalized in terms of a zero-sum game, whose payoffs refers to retailers' market share and consumers decision problem is formalized in terms of a discrete choice model, based on random utilities. The theoretical models provide forecasting of equilibrium market shares and the locations to be chosen by retailers, in terms of the geographic distribution of the underlying location space (constituencies of the town), population distribution and characteristics (types) of the consumers.Hotelling, Industrial Organization, Choice Model

    Analizando la variabilidad del registro arqueológico en sociedades cazadoras-recolectoras desde la etnoarqueología

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    Desde 1986, nuestros proyectos de investigación (en colaboración con una contraparte argentina) en la Isla Grande de Tierra del Fuego han tenido como objetivo destacado el desarrollo de una metodología para un adecuado reconocimiento de la organización social a partir de la evidencia arqueológica. El trabajo aquí presentado se concentra en uno de los asentamientos excavados durante estos proyectos, Túnel VII, ubicado en la parte argentina de la Isla Grande de Tierra del Fuego. El yacimiento, un «conchero», es altamente representativo de las sociedades canoeras de los canales fueguinos, al menos en su fase final. El método de excavación nos ha permitido reconocer la detallada secuencia de una serie de, al menos, diez episodios discretos de ocupación a lo largo de un siglo, que tuvieron lugar en la práctica totalidad de las estaciones del año. Los momentos de ocupación de Túnel VII no llevan vinculadas específicas pautas estacionales. Son estrategias de subsistencia especializadas pero «flexibles» que no se ven representadas en la estructura conceptual dual «collector» o «forager», es decir, una «especialización en la no especialización». La misma evidencia ha servido para fijar claros y definitorios comportamientos generales respecto al uso del espacio.From 1986, our research projects in Isla Grande of Tierra del Fuego, in collaboration with other Argentinian team, have emphasized the goal of developing a methodology for a proper archaeological recognition of the social organization from archaeological evidence. The work presented here focuses on one of the settlements excavated during these projects, VII Tunnel, located on the Argentine side of the Isla Grande of Tierra del Fuego. The site is highly representative of the canoe societies of the fueguian channels, at least in its final phase. The excavation method allow us to recognize the detailed sequence of a series of at least ten discrete episodes of occupation, over a century, which took place in almost all the seasons. The Tunnel VII moments of occupation do not carry specific seasonal patterns linked. Livelihood strategies are highly specialized but "flexible" that are not represented in the conceptual dual "collector" or "forager", ie "specialization in non-specialization". The same evidence has served to set clear and defining general behavior regarding the use of space

    Synthesis of HA/beta-TCP bioceramic foams from natural products

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    A novel technology for the preparation of bioceramic foams (BF) using a simple and economic procedure is presented. This technology combines two conventional methods to produce a tridimensional macroporous structure by using a sol-gel route, submitted afterward to a microwave treatment and thermal annealing. The use of agri-waste products on this procedure, such as egg shell and white egg recycle, represents an interesting way for waste management while developing potential commercial biomaterials. The use of egg shell as eco-compatible reactant instead of commercial ones and the egg white as foaming agent to produce a tridimensional macroporous structures has been optimized by using a sol-gel route. The crystalline phase and quantitative phase composition has been studied by Rietveld refinement and the optimization of the foaming process and determination of interconnected porosity by scanning electron microscopy, Hg porosimetry and X-ray micro-CT imaging. Our results show that BF samples showed a composition of 60 wt% HA (hydroxyapatite) and 40 wt% beta-TCP (beta-tricalcium phosphate) with a total porosity of approx. 70 % and a porosity ranging from 5 to 300 mu m. These features indicate that BF samples are ideal for bone regeneration, and they are produced in an easy and environmental friendly viable process

    RAZVOJ HOMOZIGOTNIH LINIJA KUKURUZA POMOĆU INDUKCIJE HAPLOIDA IN VIVO U HRVATSKOJ GERMPLAZMI

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    The in vivo haploid induction has been widely applied to the maize breeding in recent decades, but it has not been used in the breeding programs in the Republic of Croatia by now. This study\u27s objectives were to examine the haploid induction rates in the Croatian germplasm and to evaluate the properties of the D0 haploids, which are essential for a successful implementation of this method in breeding. The in vivo haploid induction was performed on 11 single-cross hybrids using the Zarodyshevy Marker Krasnodarsky (ZMK) inducer, and colchicine was used as a chromosome doubling agent. Emergence, misclassification rate, colchicine treatment survival, chromosome doubling rate and self-pollination success were examined in the D0 generation. The haploid induction rates ranged from 6.9 to 15.8%, which is consistent with the average induction rates characteristic of the ZMK inducer and the other modern ones. Significant differences were found among the populations of D0 haploids for all tested properties, except for self-pollination success. On average, the misclassification rates were lower, and the seedling survival rates were higher than those reported in other studies, indicating a possibility of a successful application of the doubled haploid method in maize breeding.Indukcija haploida in vivo posljednjih se desetljeća sve više primjenjuje u oplemenjivanju kukuruza, ali se dosad nije koristila u oplemenjivačkim programima u Republici Hrvatskoj. Ciljevi ovoga istraživanja bili su utvrditi relativne frekvencije induciranih haploida kod germplazme koja se upotrebljava u domaćim oplemenjivačkim programima i ispitati svojstva haploida generacije D0 koja su važna za uspješnu primjenu ove metode u oplemenjivanju. Indukcija haploida in vivo obavljena je na 11 jednostrukih hibrida pomoću induktora ZMK, a za udvostručenje kromosoma korišten je kolhicin. U generaciji D0 ispitana su svojstva nicanja, pogrešne klasifikacije, preživljavanja tretmana kolhicinom, udvostručenja kromosoma i uspješnosti izvođenja samooplodnje. Relativna frekvencija haploida kretala se od 6,9 do 15,8%, što je usporedivo s prosječnim stopama indukcije specifičnim za induktor ZMK i druge moderne induktore. Statistički značajne razlike pronađene su između populacija haploida D0 za sva ispitana svojstva, osim za uspješnost izvođenja samooplodnje. U prosjeku, stope pogrešne klasifikacije bile su niže, a stope preživljavanja tretmana kolhicinom više u odnosu na one zabilježene u drugim istraživanjima, što ukazuje na mogućnost uspješne primjene metode udvostručenih haploida u oplemenjivanju

    Results on Proton-Irradiated 3D Pixel Sensors Interconnected to RD53A Readout ASIC

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    Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A prototype readout ASIC are reported. Sensors from FBK (Italy) and IMB-CNM (Spain) have been tested before and after proton-irradiation to an equivalent fluence of about 11 ×\times 101610^{16} neq\text{n}_{\text{eq}} cm2^{-2} (1 MeV equivalent neutrons). This is the first time that one single collecting electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded to a fine pitch ASIC. The preliminary analysis of the collected data shows no degradation on the hit detection efficiencies of the tested sensors after high energy proton irradiation, demonstrating the excellent radiation tolerance of the 3D pixel sensors. Thus, they will be excellent candidates for the extreme radiation environment at the innermost layers of the HL-LHC experiments.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of Instrumentation, February 18-22, 2019, Vienna, Austria. arXiv admin note: text overlap with arXiv:1903.0196

    Cytoplasmic Expression of the ALS/FTD-Related Protein TDP-43 Decreases Global Translation Both in vitro and in vivo

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    TDP-43 is a major component of cytoplasmic inclusions observed in neurodegenerative diseases like frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). To further understand the role of TDP-43 in mRNA/protein metabolism and proteostasis, we used a combined approach with cellular and animal models overexpressing a cytoplasmic form of human TDP-43 (TDP-43-ΔNLS), recapitulating ALS/FTD features. We applied in HEK293 cells a method for labeling de novo translation, surface sensing of translation (SUnSET), based on puromycin (PURO) incorporation. While control cells displayed robust puromycilation, TDP-43-ΔNLS transfected cells exhibited reduced ongoing protein synthesis. Next, by using a transgenic mouse overexpressing cytoplasmic TDP-43 in the forebrain (TDP-43-ΔNLS mice) we assessed whether cytoplasmic TDP-43 regulates global translation in vivo. Polysome profiling of brain cortices from transgenic mice showed a shift toward non-polysomal fractions as compared to wild-type littermates, indicating a decrease in global translation. Lastly, cellular level translational assessment by SUNSET was performed in TDP-43-ΔNLS mice brain slices. Control mice slices incubated with PURO exhibited robust cytoplasmic PURO signal in layer 5 neurons from motor cortex, and normal nuclear TDP-43 staining. Neurons in TDP-43-ΔNLS mice slices incubated with PURO exhibited high cytoplasmic expression of TDP-43 and reduced puromycilation respect to control mice. These in vitro and in vivo results indicate that cytoplasmic TDP-43 decreases global translation and potentially cause functional/cytotoxic effects as observed in ALS/FTD. Our study provide in vivo evidence (by two independent and complementary methods) for a role of mislocalized TDP-43 in the regulation of global mRNA translation, with implications for TDP-43 proteinopathies.Fil: Charif, Santiago Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Luchelli, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Vila, Antonella. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; ArgentinaFil: Blaustein, Matías. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; ArgentinaFil: Müller Igaz, Lionel Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentin

    Comparison of internal and external load metrics between won and lost game segments in elite beach handball

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    Purpose. The extraordinary evolution of beach handball requires the relationship between the specific internal and external load in this sport to be determined in order to continue its development. For this reason, the objective of this study was to compare won and lost game segments in beach handball matches to determine if there is a relationship between winning and losing a set and the external and internal loads experienced by an elite beach handball player. Methods. The data of 57 elite beach handball players were collected over ten matches, which were divided into time segments of 2 minutes each, making a total of 100 game segments. Data were collected using GPS and GNSS technology. Results. The results showed significant differences in the variables distance per minute (d = large in male and medium in female), velocity band 2 distance (d = very large in male and large in female) and band 3 distance (d = very large in male and medium in female), accelerations (number) (d = large in male and medium in female), player load per minute (d = medium in male and in female), velocity work/rest ratio (d = very large in male and in female) and total jumps (number) (d = medium in male and large in female). Conclusions. We conclude that the external and internal load variables that determine winning or losing a game segment in elite beach handball are distance per minute, velocity bands 2 (6–8.9 km/h) and 3 (9–11.9 km/h) distance, accelerations (number), player load per minute, velocity work/rest ratio and total jumps (number), both in the male and female categories. The highest values of these variables are observed in the won segments, except for the number of jumps in women

    Análisis etnoarqueológico del valor social del producto en sociedades cazadoras-recolectoras

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    This work was formulated as a consequence of considering the necessity of a value theory (that is, an economical theory), in archaeology. From our materialist perspective, that would allow us to set the basis for an objective analysis of past societies, understanding that only through the knowledge of their material life conditions and their social organization we would be able to know their historical becoming. We were reaching a common index that would make possible to compare different occupations and sites in Tierra del Fuego. This index would be used to make inferences about the amount of work invested in every occupation, amount of work that could be understood as the duration of the occupation or as the amount of people in that camp-site. On the other hand, on the basis of the Main Contradiciton formulation, we could establi sh a mechanism to quantify different participation in the production cycle and the existing differences in the access to the consumption of what has been produced. This will drive us to the formulation of a method to identify social explotation.Este trabajo surgió como consecuencia de varias preocupaciones. En primer lugar, considerábamos, desde hacía ya tiempo, la necesidad de una teoría del valor (económica, por tanto), en Arqueología; preocupación compartida con otros investigadores/as. Desde nuestra perspectiva materialista, ello nos había de permitir sentar las bases para un análisis objetivo de las sociedades prehistóricas, entendiendo que tan sólo a través delconocimiento de Las condiciones materiales de vida, y de la estructuración u organización de las relaciones sociales, podremos llegar a conocer el devenir histórico de las mismas. Buscábamos un índice, un común denominador, que nos permitiera poder comparar diferentes ocupaciones y yacimientos actualmente (y desde hace ya más de una década) en estudio en Tierra del Fuego (Argentina). Este índice debería permitirnos, por un lado realizar inferencias sobre la cantidad de trabajo invertida en cada ocupación de los diferentes asentamientos Yámana. Lo cual podría ser interpretado en clave de ti empo de ocupación o de cantidad de personas ocupando el sitio. Y por otro lado, y sobre la base de la formulación de la Contradicción Principal, podría establecer un mecanismo que nos permitiera cuantificar la participación diferencial en la producción y las disimetrías en el acceso al consumo de lo producido, estableciendo un «cálculo» para la identificación de la explotación. Este último interés tiene mucho que ver con el aceptado concepto de «sociedades igualitarias » aplicado a las sociedades cazadoras recolectoras, concepto cuestionable en tanto que surge de una aproximación androcéntrica. Este trabajo ha sido posible, en el caso de la sociedad Yámana, gracias a la exhaustiva y variada información etnográfica confrontada a una completa información arqueológica. El objetivo final es conseguir generar propuesta metodológica contrastada que nos permita este tipo de acercamientos a sociedades cazadoras-recolectoras prehistóricas

    Página web y las ventas de la empresa Servicios Médicos Chari Dent SAC, 2020

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    El estudio realizado tuvo como objetivo determinar la influencia de la página web en las ventas de la empresa de Servicios médicos Chari Dent SAC, 2020. La investigación realizada fue de tipo aplicada, bajo el diseño pre experimental y de nivel descriptivo. La población y muestra de estudio estuvo conformada por 45 clientes del Servicio Médico Chari Dent. La técnica de estudio utilizado fue el análisis documental y el cuestionario. El cual de acuerdo a Alfa deThe objective of the study carried out was to determine the influence of the website on the sales of the Medical Services company Chari Dent SAC, 2020. The research carried out was of an applied type, under the pre-experimental design and of a descriptive level. The population and study sample consisted of 45 clients of the Chari Dent Medical Service. The study technique used was the documentary analysis and the questionnaire. Which according to Cronbach's AlphaTesi
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