On the drivers of commodity co-movement: Evidence from biofuels

We use the recent introduction of biofuels to study the effect of industry factors on the relationships between wholesale commodity prices. Correlations between agricultural products and oil are strongest in the 2005-09 period, coinciding with the boom of biofuels, and remain substantial until 2011. We disentangle three possible drivers for the linkage: substitution, energy costs, and financialization. The timing and magnitude of the biofuels-to-oil relationships are different to those of other commodities, and far higher than can be justified by costs and financialization. Substitution and costs drive the monthly correlations of long-term futures, and each of the three contribute equally to the daily co-movement of the short-term ones. The findings survive many robustness checks and appear in the stock market.biofuels, commodities, co-movement, ethanol, oil, structural breaks

On the drivers of commodity co-movement: evidence from biofuels

We use the recent introduction of biofuels to study the effect of industry factors on the relationships between wholesale commodity prices. Correlations between agricultural products and oil are strongest in the 2005-09 period, coinciding with the boom of biofuels, and remain substantial until 2011. We disentangle three possible drivers for the linkage: substitution, energy costs, and financialization. The timing and magnitude of the biofuels-to-oil relationships are different to those of other commodities, and far higher than can be justified by costs and financialization. Substitution and costs drive the monthly correlations of long-term futures, and each of the three contribute equally to the daily co-movement of the short-term ones. The findings survive many robustness checks and appear in the stock market

Periodismo de datos : caracterización de comunidades de práctica.

El presente artículo indaga por una práctica emergente para contar historias basadas en datos y visualizaciones llamada periodismo de datos. Dicho ejercicio es cada vez más común e importante para hacer trabajos investigativos alrededor de diversos temas que atañen a la sociedad; el periodismo de datos por medio de acciones más transparentes, abiertas, incluyentes, sustentadas en hechos y cifras, permite a las personas generar historias que aporten a la comunidad en general. El lector encontrará, entonces, un acercamiento a los conceptos de periodismo de datos y comunidades de práctica, así como el resultado de algunos abordajes previos. A su vez, se hará una descripción panorámica de la metodología empleada en la investigación, teniendo como referente el estudio de caso, esto permite caracterizar la praxis en comunidades locales de Colombia en aras de determinar factores que alienten la transdisciplinariedad e interdisciplinariedad; el objetivo fue alcanzado mediante acciones exploratorias y descriptivas por parte del autor, lo que permitió establecer un análisis y una caracterización de las variables que surgieron del estudio. La intervención y el estudio de resultados dan cuenta de las experiencias que permitieron identificar los ejercicios asociados al periodismo de datos en distintos eventos y colectivos dedicados a ello. Todos ellos fueron abordados a partir de la observación participante, así como de la aplicación e interpretación de instrumentos para el estudio de caso. Finalmente, se alude a las conclusiones alcanzadas en las que se establecieron las limitaciones del estudio y sus posibilidades futuras, lo que permitirá la comprensión de fenómenos emergentes como el periodismo de datos, que son pertinentes a la actualidad y quehacer del diseñador visual, y que posibilitan otros escenarios para el diseño, el individuo y la sociedad

Retrospective analysis of skin complications related to bone-anchored hearing aid implant: association with surgical technique, quality of life, and audiological benefit

Introduction The bone-anchored hearing aid is an effective form of auditory rehabilitation. Due to the nature of the implant, the most common complications are skin related. A number of alternative surgical implantation techniques have been used to reduce the frequency and severity of skin complications, including the U-shaped graft and the linear incision. Objective To assess skin complications and their association with surgical technique, quality of life, and audiological benefit in patients with bone-anchored hearing aids. Methods This was a retrospective study conducted in a tertiary referral center in Bogotá, Colombia. Patients who had been fitted with a bone-anchored hearing aid implant (unilaterally or bilaterally) for at least 6 months were included in the study. The Holgers classification was used to classify skin complications (Grade 0=none; Grade 1=erythema; Grade 2=erythema and discharge; Grade 3=granulation tissue; and Grade 4=inflammation/infection resulting in the removal of the abutment). The Glasgow Benefit Inventory questionnaire was used to determine quality of life, and the Abbreviated Profile of Hearing Aid Benefit questionnaire was used to determine the subjective audiological benefit. Results A total of 37 patients were included in the study (30 with unilateral implants and 7 with bilateral implant). Of the 44 implants evaluated, 31 (70.3%) were associated with skin complications (7 [15.9%] Grade 1; 4 [9.1%] Grade 2; 15 [34.1%] Grade 3, 5 [11.4%] Grade 4). The U-shaped graft was statistically associated with major complications (Grades 3 and 4) compared with the linear incision technique (p=0.045). No statistically significant differences were found between Abbreviated Profile of Hearing Aid Benefit scores and severity of complications. Similarly, no differences were found between Glasgow Benefit Inventory physical health questions and skin complications. Conclusion Despite the high frequency, skin complications did not seem to affect quality of life or subjective audiological benefits of patients with bone-anchored hearing aids.Introdução A prótese auditiva óssea (BAHA, do inglês Bone-Anchored Hearing Aid) é uma forma eficaz de reabilitação auditiva. Devido à natureza do implante, as complicações mais comuns são relacionadas à pele. Várias técnicas alternativas de implantação cirúrgica têm sido utilizadas para reduzir a frequência e a gravidade das complicações cutâneas, incluindo o enxerto em forma de U e a incisão linear. Objetivo Avaliar as complicações cutâneas e sua associação com a técnica cirúrgica, qualidade de vida e benefício audiológico em pacientes com BAHAs. Método Esse é um estudo retrospectivo realizado em um centro terciário de referência em Bogotá, Colômbia. Os pacientes que receberam um implante de BAHA (unilateral ou bilateralmente) durante pelo menos 6 meses foram incluídos no estudo. A classificação de Holgers foi utilizada para classificar as complicações cutâneas (Grau 0=nenhuma, Grau 1=eritema, Grau 2=eritema e secreção, Grau 3=tecido de granulação e Grau 4=inflamação/infecção resultando na remoção da estrutura de apoio). O questionário Glasgow Benefit Inventory (GBI) foi utilizado para determinar a qualidade de vida, e o questionário Abbreviated Profile of Hearing Aid Benefit (APHAB) foi utilizado para determinar o benefício audiológico subjetivo. Resultados Um total de 37 pacientes foi incluído no estudo (30 com implantes unilaterais e 7 com implantes bilaterais). Dos 44 implantes avaliados, 31 (70,3%) foram associados às complicações cutâneas (7 [15,9%] Grau 1; 4 [9,1%] Grau 2; 15 [34,1%] Grau 3, e 5 [11,4%] Grau 4). O enxerto em forma de U foi estatisticamente associado a complicações maiores (Graus 3 e 4) em comparação com a técnica de incisão linear (p=0,045). Não foram encontradas diferenças estatisticamente significativas entre os escores APHAB e gravidade das complicações. Do mesmo modo, não foram encontradas diferenças entre as questões de saúde física pelo questionário GBI e complicações cutâneas. Conclusão Apesar da alta frequência, as complicações cutâneas não parecem afetar a qualidade de vida ou os benefícios audiológicos subjetivos de pacientes com BAHA

Frequency of psichiatric comorbidities in patients with post- traumatic stress dissorder

Por medio de un estudio observacional descriptivo de corte transversal realizado en pacientes con diagnóstico de Trastorno por Estrés Postraumático (TEPT) con antecedente de exposición a combates, con grado militar de profesional, suboficial u oficial, hospitalizados por el Servicio de Psiquiatría del Hospital Militar Central de Bogotá entre enero y junio de 2008, se describe la presentación clínica de las co-morbilidades psiquiátricas asociadas al TEPT. Se detectó agorafobia en el 45,5% de los sujetos, fobia social en el 18,2%, fobias específicas (según el tipo) entre el 36,4% y el 45,5%, una prevalencia del 63,3% para trastornos depresivos y del 10% para distimia, concluyéndose que los trastornos afectivos, seguidos de ansiedad, eran las co-morbilidades más frecuentes, sin que se encontraran datos positivos para consumo de sustancias. Aunque se trata de un estudio piloto, con una muestra pequeña de tan solo once pacientes, es una primera aproximación a la investigación de co-morbilidades en una población de especial interés para la Sanidad Militar y la Defensa Nacional, que a futuro y con mayor numero de pacientes, permitirá establecer y fortalecer protocolos para su manejo.20-25The clinical presentation of the psychiatric co-morbidities associated to the Post-traumatic Stress Disorder (TEPT) is described by means of a descriptive cross section observational study made in patients with a diagnosis of TEPT with antecedent of exhibition to combats, with military rank of professional, sergeant major or official, hospitalized by the Service of Psychiatry of the Central Military Hospital of Bogota between January and June of 2008,. One detected agoraphobia in 45.5% of the subjects, social phobia in 18.2%, specific phobias (according to the type) between 36.4% and 45.5%, a prevalence of 63.3% for depressive upheavals and 10% for distimia, concluding that the affective upheavals, followed by anxiety, were the most frequent co-morbidities, without positive data for consumption of illegal substances. Although this is a pilot study, with a small sample of only eleven patients, it is the first approach to the investigation of co-morbidities in a population of special interest for the Military Health and the National Defense, which in the future and with greater number of patients, will allow to establish and to fortify protocols for its management

Aplicación de la tradición oral como herramienta para el fortalecimiento de competencias del pensamiento histórico

For a long time, traditional methods have been used as a form of learning for history in the social sciences, with more tools such as oratory, for that reason, the objective of this research is to apply oral tradition as a tool to strengthen competences of historical thought in students of the José Rueda del Palmar Technical Institute. In addition, it starts from an analysis directed towards the students, who see the history area through traditional methods. Based on this, questionnaires were designed and applied that made it possible to highlight the ninth-grade students as the research sample, after recognizing their shortcomings. For this reason, this project is carried out, seeking in this way that students understand and interpret the knowledge they acquire about national history through oral tradition as a teaching tool. To meet the objectives, a descriptive qualitative method was used, consisting firstly of the application of a diagnostic questionnaire to identify shortcomings in historical thinking, and finally a questionnaire to demonstrate the strengthening of competences in history, after the application of the oral tradition as a learning tool. After the fieldwork, it was possible to conclude that the learning tool effectively strengthened the competences of historical thinking in the studentsDurante mucho tiempo, se han utilizado métodos tradicionales como forma de aprendizaje para la historia en las ciencias sociales, existiendo más herramientas como la oratoria, por esa razón, el objetivo de esta investigación es aplicar la tradición oral como herramienta para el fortalecimiento de las competencias del pensamiento histórico en estudiantes del Instituto Técnico José Rueda del Palmar. Además, se parte de un análisis dirigido hacia los estudiantes, quienes ven el área de historia por medio de métodos tradicionales. A partir de ello se diseñaron y aplicaron cuestionarios que permitieron destacar a los alumnos de noveno grado como la muestra de investigación, luego de reconocer falencias que tenıá n. Por ello, se realiza este proyecto, buscando de esta forma que los estudiantes comprendan e interpreten el conocimiento que adquieran sobre historia nacional por medio de la tradición oral como herramienta de enseñanza. Para cumplir los objetivos se utilizó un método cualitativo descriptivo compuesto primeramente por la aplicación de un cuestionario diagnóstico para la identificación de falencias en el pensamiento histórico, y finalmente un cuestionario para demostrar el fortalecimiento de las competencias en la historia, luego de la aplicación de la tradición oral como herramienta de aprendizaje. Culminado el trabajo de campo se logró concluir que efectivamente la herramienta de aprendizaje fortaleció las competencias del pensamiento histórico en los estudiantes

Prevalencia de asma y otras enfermedades alérgicas en Colombia 2009-2010: un estudio transversal

Background: While it is suggested that the prevalence of asthma in developed countries may have stabilized, this is not clear in currently developing countries. Current available information for both adults and children simultaneously on the burden and impact of allergic conditions in Colombia and in many Latin American countries is limited. The objectives of this study were to estimate the prevalence for asthma, allergic rhinitis (AR), atopic eczema (AE), and atopy in six colombian cities; to quantify costs to the patient and her/his family; and to determine levels of Immunoglobulin E (IgE) in asthmatic and healthy subjects. Methods: We conducted a cross-sectional, population-based study in six cities during the academic year 2009–2010. We used a school-based design for subjects between 5–17 years old. We carried out a community-based strategy for subjects between 1–4 years old and adults between 18–59 years old. Serum samples for total and antigen-specific (IgE) levels were collected using a population-based, nested, case–control design. Results: We obtained information on 5978 subjects. The largest sample of subjects was collected in Bogotá (2392). The current prevalence of asthma symptoms was 12% (95% CI, 10.5-13.7), with 43% (95% CI, 36.3-49.2) reporting having required an emergency department visit or hospitalization in the past 12 months. Physician diagnosed asthma was 7% (95% CI, 6.1-8.0). The current prevalence of AR symptoms was 32% (95% CI, 29.5-33.9), and of AE symptoms was 14% (95% CI, 12.5-15.3). We collected blood samples from 855 subjects; 60.2% of asthmatics and 40.6% of controls could be classified as atopic. Conclusions: In Colombia, symptom prevalence for asthma, AR and AE, as well as levels of atopy, are substantial. Specifically for asthma, symptom severity and absence from work or study due to symptoms are important. These primary care sensitive conditions remain an unmet public health burden in developing countries such as Colombia

Prevalence of asthma and other allergic conditions in Colombia 2009-2010: a cross-sectional study

Q3Q2Artículo de investigación1-9BACKGROUND: While it is suggested that the prevalence of asthma in developed countries may have stabilized, this is not clear in currently developing countries. Current available information for both adults and children simultaneously on the burden and impact of allergic conditions in Colombia and in many Latin American countries is limited. The objectives of this study were to estimate the prevalence for asthma, allergic rhinitis (AR), atopic eczema (AE), and atopy in six colombian cities; to quantify costs to the patient and her/his family; and to determine levels of Immunoglobulin E (IgE) in asthmatic and healthy subjects. METHODS: We conducted a cross-sectional, population-based study in six cities during the academic year 2009-2010. We used a school-based design for subjects between 5-17 years old. We carried out a community-based strategy for subjects between 1-4 years old and adults between 18-59 years old. Serum samples for total and antigen-specific (IgE) levels were collected using a population-based, nested, case-control design. RESULTS: We obtained information on 5978 subjects. The largest sample of subjects was collected in Bogotá (2392). The current prevalence of asthma symptoms was 12% (95% CI, 10.5-13.7), with 43% (95% CI, 36.3-49.2) reporting having required an emergency department visit or hospitalization in the past 12 months. Physician diagnosed asthma was 7% (95% CI, 6.1-8.0). The current prevalence of AR symptoms was 32% (95% CI, 29.5-33.9), and of AE symptoms was 14% (95% CI, 12.5-15.3). We collected blood samples from 855 subjects; 60.2% of asthmatics and 40.6% of controls could be classified as atopic. CONCLUSIONS: In Colombia, symptom prevalence for asthma, AR and AE, as well as levels of atopy, are substantial. Specifically for asthma, symptom severity and absence from work or study due to symptoms are important. These primary care sensitive conditions remain an unmet public health burden in developing countries such as Colombia