124 research outputs found

    Consolidation and coating treatments for glass in the cultural heritage field: A review

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    Consolidation and coating treatments are two types of interventions that form part of the active con- servation actions developed for historical and archaeological glass over the years. While thermoplastic and thermosetting resins are widely adopted by conservators worldwide, issues related to the toxicity and the material compatibility of these products remains unsolved. To address these issues, effort s have been made to develop new formulations that can functionally replace or exhibit performance advantages with respect to these canonical polymeric materials. In this review, we discuss the main classes of ma- terials applied thus far for protection and consolidation aims in the cultural heritage glass field, starting from the beginning of the 19th century and continuing until present days. We also assess the potential of hybrid organic-inorganic materials and full inorganic materials as alternative solutions to the limita- tions of organic materials in application. Finally, we provide our perspectives on future directions for the development of consolidation products that meet the specific requirements of the cultural heritage field

    Mejoramiento de la capacidad de servicio en el cobro de peaje en la estación Chilca

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    Esta investigación se presenta con la finalidad de mejorar la capacidad de cobro en la estación de peaje Chilca, ubicada en el km. 66 de la Panamericana Sur y actualmente administrada por la empresa Concesionaria Vial del Perú. En el primer capítulo, se mostrará detalladamente la problematización del estudio, dando a conocer además nuestros objetivos, alcances y limitaciones en esta investigación. En el segundo capítulo, se presentará como base teórica investigaciones acerca de congestionamiento vehicular y teoría de colas. Además se mostrará los conceptos bases de estudio que necesitaremos para esta investigación, que son Teoría de Colas y Simulación. En el tercer y cuarto capítulo, se realizará el análisis de la situación actual del peaje, para lo cual se utilizarán los conceptos de Teoría de Colas y Simulación. Para el desarrollo de simulación se utilizará el software PROMODEL, esto con el fin de definir el modelo actual que presenta la estación de peaje en estudio. Finalmente, se mostrarán las propuestas de mejoras para éste caso, las cuales son presentadas a partir de los resultados mostrados anteriormente. La finalidad es mostrar soluciones con los cuales podemos mejorar los procesos y procedimientos, de tal manera que se incremente la capacidad de cobro sin saturar la estación de peaje.Tesi

    Silvicultural management and altitude prevail on soil properties and fungal community in shaping understorey plant communities in a Mediterranean pine forest

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    Understorey vegetation plays a key role in Mediterranean forest ecosystem functioning. However, we still lack a thorough understanding of the patterns and drivers of understorey composition and diversity. As a result, understoreys are often ignored during assessments of forest functioning under climate change. Here we studied the effect of silvicultural management, topography, soil fungal community composition and soil physical and chemical properties on understorey community composition and diversity. The plant cover and number of individuals of understorey perennial plants, shrubs and non-dominant trees was recorded on 24 plots (paired: control-thinned) in a Mediterranean pine-dominated mountainous area in Northeast Spain. The study area represented a broad thinning intensity gradient (from 0 to 70 % in removed stand basal area) along a 400-m altitudinal range (from 609 m to 1013 m). Our results showed that thinning intensity and topography explained the greatest proportion of the total variance in the understorey species composition, i.e., 18 % and 16 %, respectively. Interestingly, the effects of the silvicultural treatments were significant only when considering the altitudinal effect, so that, the main impacts of thinning on the understorey community composition occurred at low altitudes (between 609 m and 870 m). Moreover, we found a significant decrease in both richness and abundance of understorey species in both the control and thinned plots with increasing altitude, with thinned plots being significantly richer in species compared to the control plots. The difference in the understorey community sensitivity to forest thinning along the altitudinal gradient suggests changes in factors that limit plant growth. Low elevation plots were restrained by light availability while high altitudes plots limited by winter freezing temperatureThis work was supported by the Spanish Ministry of Science and Innovation and Universities (RTI2018-099315-A-I00). Josu G. Alday was supported by Ramon y Cajal fellowship (RYC-2016-20528). José Antonio Bonet and Sergio de Miguel benefitted from a Serra-Húnter Fellowship provided by the Generalitat of Catalonia

    Match It or Die: Proving Integrity by Equality

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    Cryptographic hash functions are commonly used as modification detection codes. The goal is to provide message integrity assurance by comparing the digest of the original message with the hash of what is thought to be the intended message. This paper generalizes this idea by applying it to general expressions instead of just digests: success of an equality test between a tainted data and a trusted one can be seen as a proof of high-integrity for the first item. Secure usage of hash functions is also studied with respect to the confidentiality of digests by extending secret-sensitive noninterference of Demange and Sands

    Estratégias de coping utilizadas por familiares de indivíduos em tratamento hemodialítico

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    This descriptive, qualitative study aims to identify the coping strategies used most by the family members of patients with chronic kidney disease receiving hemodialysis. The data were collected through interviews, with the Coping Strategies Inventory questionnaire administered to ten family members, and were submitted to descriptive statistics and to thematic content analysis. The strategy used most was escape-avoidance, demonstrating that the family members prefer not to face the situation. The second most-used strategy was social support, ratified by the fact that they stated that they talk with other persons and professionals, seeking information about the problem, and because they accept the support received positively. The third was problem resolution, represented by the attitude of accepting responsibility for the care, either through strong affective bonds or through a feeling of responsibility established prior to the disease. The families use coping strategies of different intensities, while, nevertheless, indicating involvement and major participation in the care for the patient.Estudio cualitativo, que trató de identificar las estrategias de afrontamiento empleadas por las familias de los pacientes con insuficiencia renal crónica en hemodiálisis. Se aplicó el Inventario de Estrategias de Afrontamiento y una questión abierta con diez familiares. Los datos cuantitativos fueron sometidos a procedimientos estatísticos y análisis de contenido cualitativo. La estrategia de mayor utilización fue el escape y evitación (oito), lo que demuestra que los miembros de las familisa preferían no tener que enfrentar esta situación. La siguiente estrategia fue utilizada más apoyo social, ya hablé con otras personas y profesionales que buscan información sobre el problema, y aceptar el apoyo positivo recibido. A terceira foi resolução de problemas, representada pela atitude em assumir o cuidado, seja pelo forte vínculo afetivo ou pelo sentimento de responsabilidade já estabelecido antes da doença. Familias de las estrategias de afrontamiento empleadas con diferentes intensidades, pero mostrando una gran implicación y la participación en el cuidado del paciente crónico.Estudo descritivo, de natureza quali-quantitativa, que objetivou identificar as estratégias de enfrentamento mais utilizadas por familiares de pacientes com doença renal crônica em hemodiálise. Os dados foram coletados por meio de entrevista, com aplicação do Inventário de Estratégias de Coping a dez familiares, e submetidos à estatística descritiva e à análise de conteúdo temática. A estratégia mais utilizada foi fuga e esquiva, demonstrando que os familiares preferiam não enfrentar a situação. A segunda estratégia mais usada foi suporte social, ratificada ao afirmarem que conversaram com outras pessoas e profissionais buscando informações sobre o problema, e por aceitarem positivamente o apoio recebido. A terceira foi resolução de problemas, representada pela atitude em assumir o cuidado, seja pelo forte vínculo afetivo ou pelo sentimento de responsabilidade já estabelecido antes da doença. As famílias empregaram estratégias de enfrentamento com intensidades diferentes, porém indicando envolvimento e grande participação no cuidado ao doente.Universidade Federal de São Paulo (UNIFESP)aff2Universidade Estadual de MaringáUEMUNIFESPSciEL

    Factors affecting adherence to guidelines for antithrombotic therapy in elderly patients with atrial fibrillation admitted to internal medicine wards

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    Current guidelines for ischemic stroke prevention in atrial fibrillation or flutter (AFF) recommend Vitamin K antagonists (VKAs) for patients at high-intermediate risk and aspirin for those at intermediate-low risk. The cost-effectiveness of these treatments was demonstrated also in elderly patients. However, there are several reports that emphasize the underuse of pharmacological prophylaxis of cardio-embolism in patients with AFF in different health care settings. AIMS: To evaluate the adherence to current guidelines on cardio-embolic prophylaxis in elderly (> 65 years old) patients admitted with an established diagnosis of AFF to the Italian internal medicine wards participating in REPOSI registry, a project on polypathologies/polytherapies stemming from the collaboration between the Italian Society of Internal Medicine and the Mario Negri Institute of Pharmacological Research; to investigate whether or not hospitalization had an impact on guidelines adherence; to test the role of possible modifiers of VKAs prescription. METHODS: We retrospectively analyzed registry data collected from January to December 2008 and assessed the prevalence of patients with AFF at admission and the prevalence of risk factors for cardio-embolism. After stratifying the patients according to their CHADS(2) score the percentage of appropriateness of antithrombotic therapy prescription was evaluated both at admission and at discharge. Univariable and multivariable logistic regression models were employed to verify whether or not socio-demographic (age >80years, living alone) and clinical features (previous or recent bleeding, cranio-facial trauma, cancer, dementia) modified the frequency and modalities of antithrombotic drugs prescription at admission and discharge. RESULTS: Among the 1332 REPOSI patients, 247 were admitted with AFF. At admission, CHADS(2) score was ≥ 2 in 68.4% of patients, at discharge in 75.9%. Among patients with AFF 26.5% at admission and 32.8% at discharge were not on any antithrombotic therapy, and 43.7% at admission and 40.9% at discharge were not taking an appropriate therapy according to the CHADS(2) score. The higher the level of cardio-embolic risk the higher was the percentage of antiplatelet- but not of VKAs-treated patients. At admission or at discharge, both at univariable and at multivariable logistic regression, only an age >80 years and a diagnosis of cancer, previous or active, had a statistically significant negative effect on VKAs prescription. Moreover, only a positive history of bleeding events (past or present) was independently associated to no VKA prescription at discharge in patients who were on VKA therapy at admission. If heparin was considered as an appropriate therapy for patients with indication for VKAs, the percentage of patients admitted or discharged on appropriate therapy became respectively 43.7% and 53.4%. CONCLUSION: Among elderly patients admitted with a diagnosis of AFF to internal medicine wards, an appropriate antithrombotic prophylaxis was taken by less than 50%, with an underuse of VKAs prescription independently of the level of cardio-embolic risk. Hospitalization did not improve the adherence to guideline

    Herbivory on the pedunculate oak along an urbanization gradient in Europe : Effects of impervious surface, local tree cover, and insect feeding guild

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    Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that-just like in non-urban areas-plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions.Peer reviewe
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