Ecological factors and adolescent marijuana use: results of a prospective study in Santiago, Chile

PURPOSE: Despite the growing evidence that ecological factors contribute to substance use, the relationship of ecological factors and illicit drugs such as marijuana use is not well understood, particularly among adolescents in Latin America. Guided by social disorganization and social stress theories, we prospectively examined the association of disaggregated neighborhood characteristics with marijuana use among adolescents in Santiago, Chile, and tested if these relationships varied by sex. METHODS: Data for this study are from 725 community-dwelling adolescents participating in the Santiago Longitudinal Study, a study of substance using behaviors among urban adolescents in Santiago, Chile. Adolescents completed a two-hour interviewer administered questionnaire with questions about drug use and factors related to drug using behaviors. RESULTS: As the neighborhood levels of drug availability at baseline increased, but not crime or noxious environment, adolescents had higher odds of occasions of marijuana use at follow up, approximately 2 years later (odds ratio [OR] = 1.39; 95% CI = 1.16–1.66), even after controlling for the study’s covariates. No interactions by sex were significant. DISCUSSION: The findings suggest that “poverty”, “crime”, and “drug problems” may not be synonyms and thus can be understood discretely. As Latin American countries re-examine their drug policies, especially those concerning decriminalizing marijuana use, the findings suggest that attempts to reduce adolescent marijuana use in disadvantaged neighborhoods may do best if efforts are concentrated on specific features of the “substance abuse environment”.We are extremely grateful to the families in Chile for their participation in this study. This study received support from the U.S. National Institute on Drug Abuse (R01 DA021181; T32 DA007267) and the Vivian A. and James L. Curtis School of Social Work Research and Training Center. (R01 DA021181 - U.S. National Institute on Drug Abuse; T32 DA007267 - U.S. National Institute on Drug Abuse; Vivian A. and James L. Curtis School of Social Work Research and Training Center

El concepto de la utilidad en el diseño de una prueba de comprensión de lectura en la lengua extranjera

Este artículo representa un diagnóstico completo de la fase de diseño de la prueba de comprensión de lectura para ingreso a estudios de posgrado de la Universidad Autónoma del Estado de México. Para realizar el diagnóstico se determinó medir el alcance del instrumento en relación a las cualidades de utilidad de Bachman y Palmer (1996) siendo éstas: confiabilidad, validez de constructo, autenticidad, interactividad, impacto y practicidad. Como la valoración implícita en la medición de utilidad hace referencia al contexto de la evaluación se describió de manera detallada dicho contexto empleando el modelo de Alderson (2000). La conclusión principal que emana de dicho análisis es que la prueba es adecuada para su contexto en cuanto al diseño pero que la operatividad de la misma se beneficiaría del desarrollo de algunas medidas de difusión.Este artículo representa un diagnóstico completo de la fase de diseño de la prueba de comprensión de lectura para ingreso a estudios de posgrado de la Universidad Autónoma del Estado de México. Para realizar el diagnóstico se determinó medir el alcance del instrumento en relación a las cualidades de utilidad de Bachman y Palmer (1996) siendo éstas: confiabilidad, validez de constructo, autenticidad, interactividad, impacto y practicidad. Como la valoración implícita en la medición de utilidad hace referencia al contexto de la evaluación se describió de manera detallada dicho contexto empleando el modelo de Alderson (2000). La conclusión principal que emana de dicho análisis es que la prueba es adecuada para su contexto en cuanto al diseño pero que la operatividad de la misma se beneficiaría del desarrollo de algunas medidas de difusión

A role for antizyme inhibitor 2 in the biosynthesis and content of serotonin and histamine in mouse mast cells

Polyamines (putrescine, spermidine and spermine; PAs) are essential for the majority of living cells. Antizymes and antizyme inhibitors are key regulatory proteins of PA levels by affecting ornithine decarboxylase and PA uptake. In addition to PAs, mast cells (MC) synthesize and store in their granules histamine (Hia) and serotonin (5-HT), which are critical for their function. Our previous studies have indicated a metabolic interplay among PAs, Hia and 5-HT in this cell type. For instance, we showed that PAs affect Hia synthesis during early stages of IL-3-induced bone marrow cell differentiation into bone marrow derived MCs (BMMCs) and demonstrated that PAs are present in MC secretory granules and are important for granule homeostasis, including Hia storage and 5-HT levels. A few years ago, a novel antizyme inhibitor (AZIN2) was described whose expression is restricted to a few tissues and cell types including brain, testis and MCs. In MCs, it was recently proposed that AZIN2 could act as a local regulator of PA biosynthesis in association with 5-HT-containing granules and with 5-HT release following MC activation. To gain insight into the role of AZIN2 in the biosynthesis and storage of 5-HT and also Hia, we have generated BMMCs from both wild-type and transgenic mice with severe Azin2 hypomorphism, and have analyzed the content of PAs, 5-HT and Hia, and some elements of their metabolisms. Spermine and 5-HT levels were reduced in Azin2 hypomorphic BMMCs compared with wild-type controls, whereas the amount of Hia was increased. Accordingly, the level of tryptophan hydroxylase 1 (the key enzyme for 5-HT biosynthesis) was reduced and the amount of enzymatic activity of histidine decarboxylase (the enzyme responsible for Hia biosynthesis) was increased in Azin2 hypomorphic BMMCs. Taken together, our results show evidence that AZIN2 has an important role in the regulation of 5-HT and Hia biosynthesis and storage in MCsUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work was supported by SAF2011-26518 (MINECO, Spain) and P10-CVI-6585 and Bio-267 (Junta de Andalucia, Spain). CIBERER is an iniciative of Instituto de Salud Carlos III (Spain)

A role for antizyme inhibitor 2 in the biosynthesis and content of histamine and serotonin in mouse mast cells

Polyamines (putrescine, spermidine and spermine; PAs) are required for the survival of the majority of living cells. Antizymes and antizyme inhibitors are key regulatory proteins of PA levels by affecting ornithine decarboxylase, the rate-limiting biosynthetic enzyme, and PA uptake. In addition to PA, mast cells (MC) synthesize and store in their granules the biogenically active amines histamine (Hia) and serotonin (5-HT), which are of critical importance for their function. Previously, we have performed several studies in this cell type regarding the interplay between the metabolisms of PAs and Hia and 5-HT. Our results showed that PAs affect Hia synthesis during early stages of IL-3-induced bone marrow cell differentiation into bone marrow derived MCs (BMMCs) and demonstrated that PAs are present in MC secretory granules and are important for granule homeostasis, including Hia storage and 5-HT levels. A few years ago, a novel antizyme inhibitor (AZIN2) was described. In contrast to AZIN1, AZIN2 expression is restricted to a few tissues and cell types including brain, testis and MCs. In MCs, it was recently described that AZIN2 could act as a local regulator of PA biosynthesis in association with the 5-HT granule content and release. At present, our aim is to gain further insight into the role of AZIN2 in the biosynthesis, storage and release of both Hia and 5-HT. In this study, we have generated BMMCs from both wild-type and transgenic mice with severe Azin2 hypomorphism, and have analyzed the content of PAs, Hia and 5-HT, and some elements of their metabolisms. Both PAs and 5-HT levels were reduced in Azin2 hypomorphic BMMCs compared with wild-type controls, whereas the amount of Hia was increased. Accordingly, the level of tryptophan hydroxylase 1 (the key enzyme for 5-HT biosynthesis) was reduced and the amount of enzymatic activity of histidine decarboxylase (the enzyme responsible for histamine biosynthesis) was increased in Azin2 hypomorphic BMMCs. Taken together, our results show evidence that AZIN2 has an important role in the regulation of Hia and 5-HT biosynthesis and storage in MCs. Department of Molecular Biology and Biochemistry, and CIBER de Enfermedades Raras (CIBER-ER), Faculty of Sciences, University of Málaga, Málaga 29071, Spain. Corresponding author: I. Fajardo ([email protected]) This work was supported by SAF2011-26518 (MINECO, Spain) and P10-CVI-6585 and Bio-267 (Junta de Andalucia, Spain). CIBERER is an iniciative of Instituto de Salud Carlos III (Spain).Universidad de Málaga. Campus de Excelencia Internacional Andalucía-Tech. SAF2011-26518 (MINECO, Spain) and P10-CVI-6585 and Bio-267 (Junta de Andalucia, Spain. CIBERER is an iniciative of Instituto de Salud Carlos III (Spain)

Exhaustive linearization for robust camera pose and focal length estimation

We propose a novel approach for the estimation of the pose and focal length of a camera from a set of 3D-to-2D point correspondences. Our method compares favorably to competing approaches in that it is both more accurate than existing closed form solutions, as well as faster and also more accurate than iterative ones. Our approach is inspired on the EPnP algorithm, a recent O(n) solution for the calibrated case. Yet we show that considering the focal length as an additional unknown renders the linearization and relinearization techniques of the original approach no longer valid, especially with large amounts of noise. We present new methodologies to circumvent this limitation termed exhaustive linearization and exhaustive relinearization which perform a systematic exploration of the solution space in closed form. The method is evaluated on both real and synthetic data, and our results show that besides producing precise focal length estimation, the retrieved camera pose is almost as accurate as the one computed using the EPnP, which assumes a calibrated camera.Peer ReviewedPostprint (author’s final draft

Ab-initio molecular dynamics simulation of hydrogen diffusion in α\alpha-iron

First-principles atomistic molecular dynamics simulation in the micro-canonical and canonical ensembles has been used to study the diffusion of interstitial hydrogen in $\alpha$-iron. Hydrogen to Iron ratios between $\theta=1/16 and 1/2 have been considered by locating interstitial hydrogen atoms at random positions in a$2 \times 2 \times 2$ supercell. We find that the average optimum absorption site and the barrier for diffusion depend on the concentration of interestitials. Iron Debye temperature decreases monotonically for increasing concentration of interstitial hydrogen, proving that iron-iron interatomic potential is significantly weakened in the presence of a large number of diffusing hydrogen atoms

Hydrothermal monitoring using embedded sensors of the actual roof system of the prado museum

El Prado Museum in Madrid has been recently submitted to a refurbishment of its roof which from been made with the traditional tiles has been changed to the use of modern waterproofing layers covered with a metallic lead finishing. Due to an unexpected damp patch that produced leaking in the hall in which Las Meninas by Velázquez was exhibited, the authors were commissioned by the Ministry of Education and Culture to study the suitability of the roof and its waterproofing properties. The study led to suggestions of modifications in the design of the roof layers, which are out of the scope of present paper. In present paper are given the behaviour of the sensors embedded in two specific areas of the roof. The sensors installed were of: temperature, relative humidity, measurement of local strain and detection of liquid water. The liquid water sensors reveal that some water is withheld in the layer just below the thermal insulation material, although it is standing. The results of over four years of readings show that the temperature attenuates over distance away from the outermost layer, where the readings are very high in summer, due to it consists of lead. During the colder seasons, in turn, the temperature in the inner layers of the roof is higher than in the outer layers. The strain recorded follows the logical evolution of temperature with no abnormal behaviour being detected. Some of relative humidity sensors had measuring problems due to water condensing on them. In summary however, if the behaviour in this area is extrapolated to the rest of the roof, it can be considered to perform correctly as intended. No more leaking events have been detected from the design modifications were incorporated to the existing roof

Stress corrosion cracking and fracture toughness variation of high strength steels.

The stress corrosion cracking process is at this moment an unknown mechanism of deterioration. It is a process that implies the joint action of the media, the presence of corrosion or a surface defect and of stress in the metal. Prestressing tendons can suffer SCC jointly with hydrogen embrittlement which dramatically changes not only the type of fracture (from ductile to brittle) but also the kinetics of the process leading to unexpected collapses. The metal should be resistant to this type of process which can be characterized by its toughness and therefore by its damage tolerance. This research shows that the Fracture Toughness change when the steel corrodes, questioning the idea that is an intrinsic characteristic of the material. The reduction in the fracture toughness of steel wires when they are in contact to aggressive media involve that the material fractures with a lower crack depth for the same stress level. That means that the material becomes less damage tolerant, which implies that it is necessary to detect defects of smaller size, as for example, small notch, pits or superficial cracks. In the paper some results of the percentage of decrease of the toughness of prestressing wires suffering corrosion are presented

High Strength Steels Fracture Toughness Variation by the Media

The stress corrosion cracking process is at this moment an unknown mechanism of deterioration. It is a process that implies the joint action of the media, the presence of corrosion or a surface defect and of stress in the metal. Prestressing tendons can suffer SCC jointly with hydrogen embrittlement which dramatically changes not only the type of fracture (from ductile to brittle) but also the kinetics of the process leading to unexpected collapses. The metal should be resistant to this type of process which can be characterized by its toughness and therefore by its damage tolerance. This research shows that the Fracture Toughness change when the steel corrodes, questioning the idea that is an intrinsic characteristic of the material. The reduction in the fracture toughness of steel wires when they are in contact to aggressive media involve that the material fractures with a lower crack depth for the same stress level. That means that the material becomes less damage tolerant, which implies that it is necessary to detect defects of smaller size, as for example, small notch, pits or superficial cracks. In the paper some results of the percentage of decrease of the toughness of prestressing wires suffering corrosion are presented

Methodology for improving the net environmental impacts of new buildings through product recovery management

Buildings contribute significantly to the global environmental load caused by human activities. There has been a growing interest in improving a building's performance over all of the life-cycle stages (production, construction, operation, and End-of-Life [EoL]). Several studies have recognized the importance of the EoL stage in buildings in terms of sustainability and Circular Economy (CE). A methodology for improving the net environmental impacts of new buildings through Product Recovery Management (PRM) is presented in this thesis. It starts with a CE perspective that emphasizes the importance of adaptive reuse of buildings over new construction. Context is established with a relevant case study in the Waterloo Region. Then, product recovery planning methods that meet environmental life-cycle objectives as well as cost objectives are presented that enhance the attractiveness of adaptive reuse as an alternative. Validation of the proposed methods is achieved through functional demonstration with case studies. Together, these methods form a rational approach to improve the net environmental impact of buildings in our economy. The overall proposed framework in this thesis have demonstrated to be effective to improve sustainability in the construction industry by providing a better understanding of the net environmental impacts and economic potential benefits of buildings' adaptive reuse. Finally, this thesis marks a reference for the development of innovative user-friendly methods and tools for reducing inefficiencies in the process of adaptive reuse through PRM