4,962 research outputs found

    Societies against the Chief? Re-examining the value of ‘heterarchy’ as a concept for examining European Iron Age societies

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    Carole Crumley’s (1979; 1995a; 1995b; 2015) explorations on the applicability of heterarchy as a concept within archaeology have been highly influential in Anglo-American discourse on social organization. Despite largely emerging from Crumley’s work on Iron Age France (Crumley, 1979), however, the relevance of heterarchy as a concept for challenging hierarchical models of European Iron Age societies has largely been restricted to Britain (e.g. Moore, 2007a; Hill, 2011), where evidence for “elites” seems most obviously lacking. Northwestern Iberia has also been a locus for discussion of acephalous and nonhierarchical social forms (Fernández-Posse & Sánchez-Palencia, 1998; González-García et al., 2011; González-Ruibal, 2012; Sastre-Prats, 2011), but one where explicit discussions of heterarchy have rarely featured. More recently, it has been argued that almost all European Iron Age societies can be regarded as “broadly heterarchical” (e.g. Bradley et al., 2015: 260), although the wider implications of this have yet to be explored. What is the place, then, of heterarchy in Iron Age studies? Has it merely become a label for all nonhierarchical models (Fernández-Götz, 2014: 36), creating various Iron Age “societies against the state” (Clastres, 1977), or does it offer ways of exploring not just alternatives to hierarchies but thicker descriptions of how all Iron Age societies worked

    Model of a continuous crystallization process for a sorbet by the moments methodology

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    La etapa de precongelación es un importante paso en el proceso de manufactura de helados y sorbetes dado que las condiciones de operación tienen una fuerte influencia sobre la microestructura y por consecuencia sobre los atributos sensoriales del producto final. Esta etapa de precongelación es llevada a cabo en un intercambiador de calor de superficie raspada donde la calidad del producto es fuertemente influenciada por las condiciones de operación tales como la temperatura de evaporación de un refrigerante, el gasto másico de la alimentación, la velocidad del raspador y una presión provocada por la introducción de aire. Con la finalidad de estudiar la pertinencia de un sistema de control basado en la influencia de las variables del proceso sobre la calidad del producto, este trabajo presenta un modelo para una cristalización continua de un sorbete utilizando la metodología de momentos, el cual es validado con datos experimentales. El modelo realizado por esta metodología de momentos es capaz de representar la influencia de las condiciones de operación durante la cristalización de sorbete sobre las características finales del producto tales como el tamaño de cristal y la temperatura de salida del intercambiador de superficie raspada (ICSR) en ausencia de aire. El modelo basado en momentos se estudia, entonces, como la reducción del modelo de la ecuación de balance de población e incluye los fenómenos de nucleación heterogénea y crecimiento. De este modo, el modelo desarrollado representa requerimientos computacionales mínimos y está altamente adaptado para tareas de optimización y/o control del proceso.Freezing is an important step in the manufacturing process of ice-cream and sorbet, since the operating conditions have a strong influence on the micro-structure, and consequently on the sensorial attributes of the final product. This steep of freezing is carried out by a scraped surface heat exchanger (SSHE) where the product quality is conditioned by process conditions as the evaporation temperature of a refrigerant fluid, the mix flow rate, the dasher speed and the cylinder pressure due to the air introduction. In order to study the relevance of a control system based on the influence of process variables on product quality, this paper presents a model for a continuous crystallization of a sorbet using the method of moments, which is validated by experimental data.The model created by this methodology has been able to represent the influence of the process conditions during the crystallization of the sorbet on the final product characteristics such as crystal size and the draw temperature in the outlet of the SSHE in absence of air. The model based in moments is studied as a reduced model of the population balance equation and includes the phenomena of heterogeneous nucleation and growth. This model developed represents minimal computational requirements and is highly adapted for optimization and/or process control tasks.Peer Reviewe

    Results for the Atlantic cod, roughhead grenadier, redfish, thorny skate and black dogfish of the Spanish Survey in the NAFO Div. 3L for the period 2003-2019

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    Since 2003, a stratified random spring bottom trawl survey was conducted by Spain in Division 3L of NAFO Regulatory Area (Flemish Pass). The surveys were carried out by the R/V “Vizconde de Eza” using bottom trawl net type Campelen. Entire series of mean catches, biomass and length distribution for Atlantic cod, roughhead grenadier, redfish, thorny skate and black dogfish are presented for the period 2003-2019

    Results for the Atlantic cod, roughhead grenadier, redfish, thorny skate and black dogfish of the Spanish Survey in the NAFO Div. 3L for the period 2003-2018

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    Since 2003, a stratified random spring bottom trawl survey was conducted by Spain in Division 3L of NAFO Regulatory Area (Flemish Pass). The surveys were carried out by the R/V “Vizconde de Eza” using bottom trawl net type Campelen. Entire series of mean catches, biomass and length distribution for Atlantic cod, roughhead grenadier, redfish, thorny skate and black dogfish are presented for the period 2003-2018

    Influence of vehicular traffic on environmental noise spectrum in the tourist route of Santa Marta City

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    Transportation demands large amounts of fuel. In particular, road transport greatly contributes to both criteria air pollutants and noise within cities. The influence of vehicular traffic on the environmental noise spectrum (as an indirect indicator of energy emission) was measured and assessed in the tourist route of Santa Marta along a 12-km road segment where five points were selected (three in the peripheral urban and two in the suburban areas). The number and type of vehicles as well as the noise levels were recorded at thirds of octave twice per day during two different weekdays. The traffic flow was composed of automobiles, with higher values in the peripheral urban area. According to the ANOVA, the noise spectrum indicated that low frequencies both had more energy than those with high frequencies and were influenced by the time of day. Low frequencies were influenced by all type of vehicles during the day, while high frequencies at both day and night, except for trucks (which were influenced in all spectrum). The results agreed with both the high velocities reached and the vehicle distribution. © 201

    Characterization of Chicken IgY Specific to Clostridium difficile R20291 Spores and the Effect of Oral Administration in Mouse Models of Initiation and Recurrent Disease

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    Indexación: Web of Science; Scopus.Clostridium difficile infection (CDI) are the leading cause of world-wide nosocomial acquired diarrhea. The current main clinical challenge in CDI is the elevated rate of infection recurrence that may reach up to 30% of the patients, which has been associated to the formation of dormant spores during the infection. We sought to characterize the effects of oral administration of specific anti-spore IgY in mouse models of CDI and recurrent CDI. The specificity of anti-spore IgY was evaluated in vitro. In both, initiation mouse model and recurrence mouse model, we evaluated the prophylactic and therapeutic effect of anti-spore IgY, respectively. Our results demonstrate that anti-spore IgY exhibited high specificity and titers against C. difficile spores and reduced spore adherence to intestinal cells in vitro. Administration of anti-spore IgY to C57BL/6 mice prior and during CDI delayed the appearance of the diarrhea by 1.5 day, and spore adherence to the colonic mucosa by 90%. Notably, in the recurrence model, co-administration of anti-spore IgY coupled with vancomycin delayed the appearance of recurrent diarrhea by a median of 2 days. Collectively, these observations suggest that anti-spore IgY antibodies may be used as a novel prophylactic treatment for CDI, or in combination with antibiotics to treat CDI and prevent recurrence of the infection.https://www.frontiersin.org/articles/10.3389/fcimb.2017.00365/ful

    Serum sample containing endogenous antibodies interfering with multiple hormone immunoassays. Laboratory strategies to detect interference

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    Objectives: Endogenous antibodies (EA) may interfere with immunoassays, causing erroneous results for hormone analyses. As (in most cases) this interference arises from the assay format and most immunoassays, even from different manufacturers, are constructed in a similar way, it is possible for a single type of EA to interfere with different immunoassays. Here we describe the case of a patient whose serum sample contains EA that interfere several hormones tests. We also discuss the strategies deployed to detect interference. Subjects and methods: Over a period of four years, a 30-year-old man was subjected to a plethora of laboratory and imaging diagnostic procedures as a consequence of elevated hormone results, mainly of pituitary origin, which did not correlate with the overall clinical picture. Results: Once analytical interference was suspected, the best laboratory approaches to investigate it were sample reanalysis on an alternative platform and sample incubation with antibody blocking tubes. Construction of an in-house ''nonsense'' sandwich assay was also a valuable strategy to confirm interference. In contrast, serial sample dilutions were of no value in our case, while polyethylene glycol (PEG) precipitation gave inconclusive results, probably due to the use of inappropriate PEG concentrations for several of the tests assayed. Conclusions: Clinicians and laboratorians must be aware of the drawbacks of immunometric assays, and alert to the possibility of EA interference when results do not fit the clinical pattern

    Testing the goodness of fit of a hilbertian autoregressive model

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    The presented methodology for testing the goodness-of-fit of an Autoregressive Hilbertian model (ARH(1) model) provides an infinite-dimensional formulation of the approach proposed in Koul and Stute (1999), based on empirical process marked by residuals. Applying a central and functional central limit result for Hilbert-valued martingale difference sequences, the asymptotic behavior of the formulated H-valued empirical process, also indexed by H, is obtained under the null hypothesis. The limiting process is H-valued generalized (i.e., indexed by H) Wiener process, leading to an asymptotically distribution free test. Consistency is also analyzed. The case of misspecified autocorrelation operator of the ARH(1) process is addressed as well. Beyond the Euclidean setting, this approach allows to implement goodness of fit testing in the context of manifold and spherical functional autoregressive processes

    Results for the Atlantic cod, roughhead grenadier, redfish, thorny skate and black dogfish of the Spanish Survey in the NAFO Div. 3L for the period 2003-2016

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    Since 2003, a stratified random spring bottom trawl survey was conducted by Spain in Division 3L of NAFO Regulatory Area (Flemish Pass). The surveys were carried out by the R/V “Vizconde de Eza” using bottom trawl net type Campelen. Entire series of mean catches, biomass and length distribution for Atlantic cod, roughhead grenadier, redfish, thorny skate and black dogfish are presented for the period 2003-2016.Postprin
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