Estudio de los picos tallados de la época preeuropea de Gran Canaria. Un ejemplo de especialización en el trabajo a partir de las evidencias recuperadas en la cantera de molinos de Montaña Quemada

In this paper we present the study of chipped stone picks. These instruments were employed to work rocks in several ways(working in quarries, excavating mine galleries and other enclosures, manufacturing tools, etc.). The artifacts were recoveredin the excavation of a quarry for the production of rotator milling stones (Montaña Quemada, Gran Canaria). In thequarries intensive productive processes were developed, where picks were submitted to strong mechanical and frictionalstresses, which caused frequent accidents requiring continuous repairs. These circumstances made it necessary to developa type of artifact with technical features that allowed reshaping and resharpening tasks in order to extend its active life. Acombination of morphotechnical and functional studies, along with the refitting results, have enabled us to reconstruct theirknapping and use strategies, showing a high level of skill. In addition, this analysis has involved defining, for the first time,the different categories of byproducts generated during the process of the configuration and reconfiguration of the picks.Their detailed description will make it possible to recognize them in other archaeological contexts.En este artículo se presentan los resultados del estudio de una muestra de picos de piedra tallada, útiles empleadospara trabajar la piedra en diversas labores (cantería, excavación de cuevas y minas, fabricación de herramientas…),procedentes de la excavación de una cantera de molinos de mano rotatorios (Montaña Quemada, Gran Canaria). Enlas canteras se desarrollaron unos procesos productivos intensivos, en los que los picos eran sometidos a un fuerteestrés mecánico y de fricción, que provocaba numerosos accidentes y desgastes, exigiendo continuas reparaciones. Elloobligó a concebir un tipo de artefacto con unas características que permitieran realizar gestos de remodelación queperduraran su vida activa. La combinación de los estudios morfotécnicos, funcionales y los remontajes obtenidos hapermitido reconstruir unas estrategias de talla y de uso que revelan un gran conocimiento del arte de la talla y la cantería.En este análisis se han definido por primera vez las diversas categorías de productos generados en esos procesos,lo que permitirá reconocerlas en los diversos contextos arqueológicos de la isla

Radiopacity of calcium hydroxide cement compared with human tooth structure

AIMS: All materials added to teeth should present an adequate radiopacity to allow the detection of secondary caries. Usually, in extensive cavities, base materials like calcium hydroxide cement are used for the purpose of protecting the pulp. In an attempt to improve the efficiency of radiographic detection of this material, this study aimed to determine the radiopacity of three calcium hydroxide cements and to compare the radiopacity of these materials with dentin and enamel. METHODS: Radiographs were taken of 1-mm thick specimens of three calcium hydroxide cements: Hydro-C, Dycal and Life, an aluminium stepwedge, a lead foil, and one 1-mm thick human tooth slice. Densitometric measurements were obtained after radiographic processing. The radiopacity values of the calcium hydroxide cements, dentin and enamel were expressed in terms of the equivalent thickness of aluminium. RESULTS: The analysis of variance indicated statistically significant difference only for Life, which presented the lowest radiopacity when compared to the other cements. However, all cements and enamel possessed a radiopacity equivalent to 2mm Al, while dentin presented a radiopacity equivalent to 1mm Al. CONCLUSION: All tested cements presented a similar radiopacity to that of enamel and they meet the ISO 4049 specifications.OBJETIVOS: Todos os materiais adicionados aos dentes deveriam apresentar uma adequada radiopacidade para permitir a detecção de cáries secundárias. Geralmente em cavidades extensas, materiais de base, como o cimento de hidróxido de cálcio, são usados com a função de proteger a polpa. Na tentativa de melhorar a eficiência na detecção radiográfica deste material, este estudo foi realizado com o objetivo de determinar a radiopacidade de três cimentos de hidróxido de cálcio e comparar a radiopacidade destes materiais com a da dentina e do esmalte. MATERIAIS E MÉTODO: Foram radiografados corpos de prova de 1 mm de espessura de três cimentos de hidróxido de cálcio: Hydro-C, Dycal e Life, uma escala de densidade de alumínio, uma lâmina de chumbo e um corte de dente humano de 1 mm de espessura. As densidades ópticas foram obtidas após o processamento radiográfico. Os valores de radiopacidade dos cimentos de hidróxido de cálcio, dentina e esmalte foram expressos em espessuras equivalentes de alumínio. RESULTADOS: A análise de variância indicou diferença estatisticamente significativa apenas para o cimento Life que apresentou a menor radiopacidade quando comparado aos outros cimentos. Entretanto, todos os cimentos e o esmalte possuíram uma radiopacidade equivalente a 2 mm de Al, enquanto a dentina apresentava radiopacidade equivalente a 1 mm de Al. CONCLUSÃO: Todos os cimentos testados apresentaram radiopacidades semelhantes à do esmalte, estando de acordo com as especificações da ISO 4049

La experiencia como base de los procesos de generación de valor: un análisis longitudinal en el sector del turismo de nieve

El presente trabajo en curso conjuga contribuciones de la literatura de la experiencia y de la lógica de servicio para desarrollar un modelo teórico que establezca la importancia de la experiencia en los procesos de generación de valor en el ámbito turístico. El objetivo del estudio es la conceptualización multidimensional de la experiencia, estableciendo su relación con el valor y aplicando un enfoque longitudinal para profundizar en el conocimiento de la naturaleza dinámica de dicha relación. En un futuro, se espera validar el modelo propuesto en el ámbito turístico y testar la relación experiencia-valor durante el pre-consumo, consumo y post-consumo de un servicio turístico. Los resultados esperados permitirán establecer las pautas para una óptima gestión global de las experiencias en las organizaciones, enfocada a la maximización del valor acumulado para el cliente de manera longitudinal.This study uses insights from current research in the experience economy and service logic to develop a theoretical model establishing the importance of experience in value generation processes in the tourism sphere. The aim of the study is to give a multidimensional coneptualization that defines what experience is, explaining relationship between experience and value generation and applying a longitudinal approach. Validation of the proposed model willl be carried out in a tourism service context, testing the role of experience in value generation processes during pre-consumption, consumption and post-consumption phases. Findings from this study will allow practitioners to establish a guideline for customer experience management that leads companies to maximize customer value through different consumption phases

Uso de la tomografía computarizada en el diagnóstico de la anquilosis de la articulación temporomandibular: presentación de dos casos clínicos

La anquilosis de la articulación temporomandibular es definida como la abolición o limitación de los movimientos de dicha articulación. Radiográficamente la anquilosis demuestra aspectos bien característicos que facilitan el diagnóstico, sin embargo, su análisis en las técnicas radiográficas convencionales, en la mayoría de las veces, no se presenta de forma clara. Con la evolución de las técnicas radiográficas, la tomografía computarizada pasó a ser un examen de gran importancia en el diagnóstico de las anquilosis temporomandibulares. En vista de ello, el presente trabajo se propone mostrar y describir imágenes tomográficas de la anquilosis de esta articulación, presentando dos casos clínicos, utilizando diversos planos, como el axial y el coronal, además del uso de la reconstrucción sagital y en 3D, con la finalidad de orientar una correcta indicación e interpretación de este examen, el cual representa una valiosa herramienta para los profesionales de la Odontología.Ankylosis of the temporomandibular joint is characterized by restriction or limitation of mandibular movement. It presents as a classic symptom a limited range of motion on opening. Radiographically, ankylosis presents features that facilitate the diagnosis. However, its visualization is not clear in most of the cases involving conventional radiographic techniques. With the evolution of radiographic techniques, computed tomography (CT) became an important examination in the diagnosis of the ankylosis of temporomandibular joint. Due to the increasing use of the CT and its importance in the diagnosis of this disease, the aim of this paper is to present and describe tomographic images of ankylosis of this joint by presenting two clinical cases, using several slices as axial, coronal, and three-dimensional reformatted images

Computed tomography of the TMJ in diagnosis of ankylosis : two case reports

Ankylosis of the temporomandibular joint is characterized by restriction or limitation of mandibular movement. It presents as a classic symptom a limited range of motion on opening. Radiographically, ankylosis presents features that facilitate the diagnosis. However, its visualization is not clear in most of the cases involving conventional radiographic techniques. With the evolution of radiographic techniques, computed tomography (CT) became an important examination in the diagnosis of the ankylosis of temporomandibular joint. Due to the increasing use of the CT and its importance in the diagnosis of this disease, the aim of this paper is to present and describe tomographic images of ankylosis of this joint by presenting two clinical cases, using several slices as axial, coronal, and three-dimensional reformatted images

The quarry and workshop of Barranco Cardones (Gran Canaria, Canary Islands): Basalt quern production using stone tools

Querns for grinding cereals were essential in the everyday life of the Pre-European population of the Island of Gran Canaria as their agriculture was based mainly on barley and wheat, cereals processed for the most part in the form of roasted flour. Rotary querns and other grinding stones, nonetheless, have rarely been the object of research in the Canary Islands and the study of their operational sequence of production has only recently been initiated. Volcanic tuff (compact lapilli) was the most commonly quarried rock. Other raw materials such as basalt, and to a lesser extension tephrite, were also worked. Since metal tools were not known in the Canary Islands in Pre-European contexts, all of the stages of extraction and fashioning had to be carried out with stone tools.This paper analyses the operational sequence, that is, the different phases of the extraction and fashioning techniques of basalt rotary querns based on the recent finds of two quarries located near the coast (Cardones and Cebolla) and a quern manufacturing workshop (Cave 36, Arucas Municipality) in a ravine about 600 m inland. Traditionally it was thought that the Pre-European population of Gran Canaria fashioned their querns from naturally detached volcanic surface blocks collected in ravines or along the coast. This supposition was based on the idea that the early Canarians were not capable of extracting blocks from bedrock with stone tools. This notion, however, has been proven wrong by the circular extraction negatives on the quarry faces and by finds of stone fashioning tools in the workshop

Psychological intervention program to control stress in youth soccer players

The influence on the psychological well-being of the players and their sports performance seems to be one of the keys to the current sports practice. The purpose of this study was to determine the effectiveness of a psychological intervention program for stress control in youth soccer players. A total sample of 19 male youth soccer players (age: 16.3 ± 0.99 years; years playing soccer: 10.89 ± 1.56 years) completed the current research. The Psychological Characteristics Questionnaire related to Sports Performance (CPRD) was used to assess stress factors related to sports competition. A program based on Cognitive-Behavioral Therapy was implemented during eight sessions of approximately 50 min each. A pre-post design was used and statistical differences between pre- and post-measures were checked through dependent sample t-tests. The results indicated that the post-test scores were higher than the pre-tests in "Influence of the Evaluation of Performance" and "Mental Skills" factors, which supposes a significant improvement of the stress management related to performance evaluation, as well as the use of psychological resources and techniques. In addition, the post-test scores were also higher in the "Stress Control" factor, although in this case the differences were not statistically significant. Practical indications deriving from the findings of this study can help youth soccer players to manage the stress of competition using a psychological training program

Inflammatory nociception diminishes dopamine release and increases dopamine D2 receptor mRNA in the rat's insular cortex

<p>Abstract</p> <p>Background</p> <p>The insular cortex (IC) receives somatosensory afferent input and has been related to nociceptive input. It has dopaminergic terminals and D1 (D1R) -excitatory- and D2 (D2R) -inhibitory- receptors. D2R activation with a selective agonist, as well as D1R blockade with antagonists in the IC, diminish neuropathic nociception in a nerve transection model. An intraplantar injection of carrageenan and acute thermonociception (plantar test) were performed to measure the response to inflammation (paw withdrawal latency, PWL). Simultaneously, a freely moving microdyalisis technique and HPLC were used to measure the release of dopamine and its metabolites in the IC. Plantar test was applied prior, one and three hours after inflammation. Also, mRNA levels of D1 and D2R's were measured in the IC after three hours of inflammation.</p> <p>Results</p> <p>The results showed a gradual decrease in the release of dopamine, Dopac and HVA after inflammation. The decrease correlates with a decrease in PWL. D2R's increased their mRNA expression compared to the controls. In regard of D1R's, there was a decrease in their mRNA levels compared to the controls.</p> <p>Conclusions</p> <p>Our results showed that the decreased extracellular levels of dopamine induced by inflammation correlated with the level of pain-related behaviour. These results also showed the increase in dopaminergic mediated inhibition by an increase in D2R's and a decrease in D1R's mRNA. There is a possible differential mechanism regarding the regulation of excitatory and inhibitory dopaminergic receptors triggered by inflammation.</p

Estudo comparativo das idades ósseas estimadas pelos métodos TW2 e TW3 numa população brasileira

OBJECTIVE: The aim of this study was to determine the differences between the skeletal ages estimated by TW2 and TW3 methods through their RUS and Carpal systems. MATERIAL AND METHODS: A sample of two hundred and forty hand and wrist radiographs of male and female Brazilian children aged 84-199 months was evaluated by five observers. The Dunnet test was performed for statistical analysis. RESULTS: Results showed higher skeletal ages estimated by TW2RUS than TW3RUS and Carpal for both genders. For girls a statistically significant difference (pOBJETIVO: O objetivo deste estudo foi determinar as diferenças entre as idades esqueletais estimadas pelos métodos TW2 e TW3, usando os sistemas RUS e Carpal. MATERIAL E MÉTODOS: Uma amostra de 240 radiografias de mão e punho de crianças brasileiras de ambos os sexos com idade cronológica entre 84 e 199 meses foram avaliadas por cinco observadores. Para análise estatística dos dados foi aplicado o Teste de Dunnet. RESULTADOS: Os resultados demonstraram que as idades esqueletais estimadas pelo método TW2RUS foram mais avançadas que aquelas estimadas pelos métodos TW3RUS e Carpal, para ambos os sexos. Para o sexo feminino, uma diferença estatisticamente significante (