Low-frequency drug-resistant HIV-1 and risk of virological failure to first-line NNRTI-based ART: a multicohort European case-control study using centralized ultrasensitive 454 pyrosequencing.

OBJECTIVES: It is still debated if pre-existing minority drug-resistant HIV-1 variants (MVs) affect the virological outcomes of first-line NNRTI-containing ART. METHODS: This Europe-wide case-control study included ART-naive subjects infected with drug-susceptible HIV-1 as revealed by population sequencing, who achieved virological suppression on first-line ART including one NNRTI. Cases experienced virological failure and controls were subjects from the same cohort whose viraemia remained suppressed at a matched time since initiation of ART. Blinded, centralized 454 pyrosequencing with parallel bioinformatic analysis in two laboratories was used to identify MVs in the 1%-25% frequency range. ORs of virological failure according to MV detection were estimated by logistic regression. RESULTS: Two hundred and sixty samples (76 cases and 184 controls), mostly subtype B (73.5%), were used for the analysis. Identical MVs were detected in the two laboratories. 31.6% of cases and 16.8% of controls harboured pre-existing MVs. Detection of at least one MV versus no MVs was associated with an increased risk of virological failure (OR = 2.75, 95% CI = 1.35-5.60, P = 0.005); similar associations were observed for at least one MV versus no NRTI MVs (OR = 2.27, 95% CI = 0.76-6.77, P = 0.140) and at least one MV versus no NNRTI MVs (OR = 2.41, 95% CI = 1.12-5.18, P = 0.024). A dose-effect relationship between virological failure and mutational load was found. CONCLUSIONS: Pre-existing MVs more than double the risk of virological failure to first-line NNRTI-based ART.

Macroeconomics: Science or Faith Based Discipline?

Whether or not macroeconomics is a science depends on the scientific nature of macroeconomic theories and how the discipline responds when the empirical evidence fails to match the underlying assumptions and predictions of the theories. By way of an example, four conditions for macroeconomics to be a science are developed and used to examine the 'modern' theories of the Phillips curve. It is found that while the discipline in general maintains one condition it routinely violates the other three. This suggests the macroeconomics discipline has some way to go before it can call itself a 'pure science.'

EEG-based functional brain networks: does the network size matter?

Functional connectivity in human brain can be represented as a network using electroencephalography (EEG) signals. These networks--whose nodes can vary from tens to hundreds--are characterized by neurobiologically meaningful graph theory metrics. This study investigates the degree to which various graph metrics depend upon the network size. To this end, EEGs from 32 normal subjects were recorded and functional networks of three different sizes were extracted. A state-space based method was used to calculate cross-correlation matrices between different brain regions. These correlation matrices were used to construct binary adjacency connectomes, which were assessed with regards to a number of graph metrics such as clustering coefficient, modularity, efficiency, economic efficiency, and assortativity. We showed that the estimates of these metrics significantly differ depending on the network size. Larger networks had higher efficiency, higher assortativity and lower modularity compared to those with smaller size and the same density. These findings indicate that the network size should be considered in any comparison of networks across studies.

Long-term effect of a school-based physical activity program (KISS) on fitness and adiposity in children: a cluster-randomized controlled trial.

BACKGROUND: School-based intervention studies promoting a healthy lifestyle have shown favorable immediate health effects. However, there is a striking paucity on long-term follow-ups. The aim of this study was therefore to assess the 3 yr-follow-up of a cluster-randomized controlled school-based physical activity program over nine month with beneficial immediate effects on body fat, aerobic fitness and physical activity. METHODS AND FINDINGS: Initially, 28 classes from 15 elementary schools in Switzerland were grouped into an intervention (16 classes from 9 schools, n = 297 children) and a control arm (12 classes from 6 schools, n = 205 children) after stratification for grade (1st and 5th graders). Three years after the end of the multi-component physical activity program of nine months including daily physical education (i.e. two additional lessons per week on top of three regular lessons), short physical activity breaks during academic lessons, and daily physical activity homework, 289 (58%) participated in the follow-up. Primary outcome measures included body fat (sum of four skinfolds), aerobic fitness (shuttle run test), physical activity (accelerometry), and quality of life (questionnaires). After adjustment for grade, gender, baseline value and clustering within classes, children in the intervention arm compared with controls had a significantly higher average level of aerobic fitness at follow-up (0.373 z-score units [95%-CI: 0.157 to 0.59, p = 0.001] corresponding to a shift from the 50th to the 65th percentile between baseline and follow-up), while the immediate beneficial effects on the other primary outcomes were not sustained. CONCLUSIONS: Apart from aerobic fitness, beneficial effects seen after one year were not maintained when the intervention was stopped. A continuous intervention seems necessary to maintain overall beneficial health effects as reached at the end of the intervention. TRIAL REGISTRATION: ControlledTrials.com ISRCTN15360785.

La revolución energética cubana en la UCLV: ¿un paso en el camino hacia la sostenibilidad?. Parte I: Análisis de los impactos ambientales

La Revolución Energética Cubana (REC) surge de las necesidades de resolver la situación social y económica de Cuba, sumergida en una crisis energética con constantes apagones que limitaban por completo todo desarrollo del país. La REC (2006) se basa en los principios de la autosuficiencia energética, el ahorro y uso racional de la energía, y el incremento de la eficiencia en todos los aspectos. En el presente trabajo se realiza el análisis de la sostenibilidad socio-ambiental de la REC en la Universidad Central Marta Abreu de Las Villas (UCLV), ubicada en Santa Clara (Cuba). La valoración se ha efectuado mediante el análisis de los impactos ambientales y sociales en dos estudios paralelos que se complementan aplicando la técnica de conmensurabilidad débil. El conjunto de los programas de la REC han propiciado mejoras en el suministro eléctrico y en el ahorro energético, disminuyendo en un 44% las emisiones de CO2, a pesar del incremento en la actividad docente y en la flota de equipos. Las medidas adoptadas han incidido en la calidad de la docencia, las condiciones de vida, la concienciación y la participación de la población, dando lugar a un impacto social positivo. De esta manera, el balance global de la REC es positivo ya que ha permitido el desarrollo de la UCLV sin incrementar los impactos ambientales, por lo que se puede considerar un paso en el camino hacia la sostenibilidad socio-ambiental.

La revolución energética cubana en la UCLV: ¿un paso en el camino hacia la sostenibilidad?. Parte II: Análisis de los impactos sociales

La Revolución Energética Cubana (REC) surge de las necesidades de resolver la situación social y económica de Cuba, sumergida en una crisis energética con constantes apagones que limitaban por completo el desarrollo del país. La REC (2006) es un conjunto de medidas basadas en los principios de la autosuficiencia energética, el ahorro y uso racional de la energía, y el incremento de la eficiencia en todos los aspectos. En el presente trabajo se realiza el análisis de la sostenibilidad socio-ambiental de la REC en la Universidad Central Marta Abreu de las Villas (UCLV), ubicada en Santa Clara (Cuba). La valoración se ha efectuado mediante el análisis de los impactos ambientales y sociales en dos estudios paralelos que se complementan aplicando la técnica de conmensurabilidad débil. El conjunto de los programas de la REC han propiciado mejoras en el suministro eléctrico y en el ahorro energético, disminuyendo en un 30% las emisiones de CO2, a pesar del incremento en la actividad docente y en la flota de equipos, en la universidad. Las medidas adoptadas han incidido en la calidad de la docencia, las condiciones de vida, la concienciación y la participación de la población, dando lugar a un impacto social positivo. De esta manera, el balance global de la REC se califica de positivo ya que ha permitido el desarrollo de la UCLV sin incrementar los impactos ambientales, por lo que se puede considerar un paso en el camino hacia la sostenibilidad socio-ambiental.

A Modulated Closed Form solution for Quantitative Susceptibility Mapping - A thorough evaluation and comparison to iterative methods based on edge prior knowledge.

The aim of this study is to perform a thorough comparison of quantitative susceptibility mapping (QSM) techniques and their dependence on the assumptions made. The compared methodologies were: two iterative single orientation methodologies minimizing the l2, l1TV norm of the prior knowledge of the edges of the object, one over-determined multiple orientation method (COSMOS) and anewly proposed modulated closed-form solution (MCF). The performance of these methods was compared using a numerical phantom and in-vivo high resolution (0.65mm isotropic) brain data acquired at 7T using a new coil combination method. For all QSM methods, the relevant regularization and prior-knowledge parameters were systematically changed in order to evaluate the optimal reconstruction in the presence and absence of a ground truth. Additionally, the QSM contrast was compared to conventional gradient recalled echo (GRE) magnitude and R2* maps obtained from the same dataset. The QSM reconstruction results of the single orientation methods show comparable performance. The MCF method has the highest correlation (corrMCF=0.95, r(2)MCF =0.97) with the state of the art method (COSMOS) with additional advantage of extreme fast computation time. The l-curve method gave the visually most satisfactory balance between reduction of streaking artifacts and over-regularization with the latter being overemphasized when the using the COSMOS susceptibility maps as ground-truth. R2* and susceptibility maps, when calculated from the same datasets, although based on distinct features of the data, have a comparable ability to distinguish deep gray matter structures.

Estudi comparatiu del sòl d'una vinya de Sant Pere de Ribes

Treball de recerca realitzat per una alumna d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. Anàlisi comparatiu de diferents propietats del sòl d’una vinya on s’ha observat que els peus presenten un creixement desigual. A partir d'una observació a simple vista de les plantes de la vinya i del sòl sobre el qual es desenvolupen, es proposa la hipòtesi de que el sòl pot ser un factor determinant per aquest creixement desigual. Després de fer una recerca bibliogràfica sobre l’edafologia, les propietats del sòl i els tipus de sòl que es poden trobar als voltants de Sant Pere de Ribes, l’autora ha fet una selecció de propietats físico-químiques que poden estar més relacionades amb el creixement de les plantes. Després de fer el mostreig i seguir els protocols de laboratori s’han analitzat els resultats i s’han redactat les conclusions. Les propietats estudiades han permès determinar els tipus de sòl, uns sòls de textures entre franco-arenoses i areno-franques. S’ha trobat també una correlació entre les diverses propietats estudiades: un sòl de porositat elevada, que presenta valors alts de velocitat d’infiltració i per tant amb baixa capacitat de retenció d’aigua disponible, no sembla el sòl ideal per al desenvolupament de les plantes de vinya. A partir del treball es plantegen noves incògnites sobre les adaptacions dels ceps a aquests tipus de sòl o sobre la qualitat del raïm que s'hi pot desenvolupar.

Fabricació i anàlisi del biodièsel

La producció de biodièsel a partir d'olis de cuina utilitzats, amb l'objectiu de transformar un residu en un producte amb valor comercial i ambiental, és més net que els combustibles fòssils i contribueix a disminuir el gran consum de petroli que estem fent. En una primera part teòrica s’ha realitzat un treball de recerca d' informació del biodièsel per saber si és un bon combustible i si podria ser un possible substitut dels combustibles fòssils. En quant a la part pràctica l'objectiu principal ha estat fabricar el biodièsel . Les matèries primeres són oli de gira-sol i oli de cuina utilitzat, per tal de comparar les seves qualitats. S’ha arribat a la conclusió que presenten característiques molt semblants. Després de fer les anàlisis físico-químics de qualitat vam fer una mescla dels dos biodièsels fabricats, i el vam provar en un motor Dièsel per comprovar si funciona correctament i fer una comparació dels gasos emesos pel nostre combustible amb els emesos pel gasoil comercial. El resultat va ser molt positiu ja que el motor va funcionar correctament, i la comparació de gasos va sortir tal i com esperàvem ja que les quantitats de diòxid i monòxid de carboni emeses eren menors que en el gasoil.

Frequency of platelet type versus type 2B von Willebrand disease. An international registry-based study.

Less than 50 patients are reported with platelet type von Willebrand disease (PT-VWD) worldwide. Several reports have discussed the diagnostic challenge of this disease versus the closely similar disorder type 2B VWD. However, no systematic study has evaluated this dilemma globally. Over three years, a total of 110 samples/data from eight countries were analysed. A molecular approach was utilised, analysing exon 28 of the von Willebrand factor (VWF) gene, and in mutation negative cases the platelet GP1BA gene. Our results show that 48 cases initially diagnosed as putative type 2B/PT-VWD carried exon 28 mutations consistent with type 2B VWD, 17 carried GP1BA mutations consistent with a PT-VWD diagnosis, three had other VWD types (2A and 2M) and five expressed three non-previously published exon 28 mutations. Excluding 10 unaffected family members and one acquired VWD, 26 cases did not have mutations in either genes. Based on our study, the percentage of type 2B VWD diagnosis is 44% while the percentage of misdiagnosis of PT-VWD is 15%. This is the first large international study to investigate the occurrence of PT-VWD and type 2B VWD worldwide and to evaluate DNA analysis as a diagnostic tool for a large cohort of patients. The study highlights the diagnostic limitations due to unavailability/poor application of RIPA and related tests in some centres and proposes genetic analysis as a suitable tool for the discrimination of the two disorders worldwide. Cases that are negative for both VWF and GP1BA gene mutations require further evaluation for alternative diagnoses.

Discontinuous Galerkin methods for the one-dimensional Vlasov-Poisson system

We construct a new family of semi-discrete numerical schemes for the approximation of the one-dimensional periodic Vlasov-Poisson system. The methods are based on the coupling of discontinuous Galerkin approximation to the Vlasov equation and several finite element (conforming, non-conforming and mixed) approximations for the Poisson problem. We show optimal error estimates for the all proposed methods in the case of smooth compactly supported initial data. The issue of energy conservation is also analyzed for some of the methods.

Gambling among youths in Switzerland and its association with other addictive behaviours: a population-based study.

OBJECTIVE: To assess the prevalence of problem gambling in a population of youths in Switzerland and to determine its association with other potentially addictive behaviours. METHODS: Cross-sectional survey including 1,102 participants in the first and second year of post-compulsory education, reporting gambling, socio-demographics, internet use and substance use. For three categories of gambling (nongambler; nonproblem gambler and at-risk/problem gambler). socio-demographic and addiction data were compared using a bivariate analysis. All significant variables were included in a multinominal logistic regression using nongamblers as the reference category. RESULTS: The prevalence of gamblers was 37.48% (n = 413), with nonproblem gamblers being 31.94% (n = 352) and at-risk/problem gamblers 5.54% (n = 61). At the bivariate level, severity of gambling increased among adults (over 18 years) and among males, vocational students, participants not living with both parents and youths having a low socio-economic status. Gambling was also associated to the four addictive behaviours studied. At the multivariate level, risk of nonproblem gambling was increased in males, older youths, vocational students, participants of Swiss origin and alcohol misusers. Risk of at-risk/problem gambling was higher for males, older youths, alcohol misusers, participants not living with both parents and problem internet users. CONCLUSIONS: One-third of youths in our sample had gambled in the previous year and gambling is associated with other addictive behaviours. Clinicians should screen their adolescent patients for gambling habits, especially if other addictive behaviours are present. Additionally, gambling should be included in prevention campaigns together with other addictive behaviours.

GPs' role in the detection of psychological problems of young people: a population-based study.

BACKGROUND: Among young people, about one in three females and one in five males report experiencing emotional distress but 65-95% of them do not receive help from health professionals. AIM: To assess the differences among young people who seek help and those who do not seek help for their psychological problems, considering the frequency of consultations to their GP and their social resources. DESIGN OF STUDY: School survey. SETTING: Post-mandatory school. METHOD: Among a Swiss national representative sample of 7429 students and apprentices (45.6% females) aged 16-20 years, 1931 young people reported needing help for a problem of depression/sadness (26%) and were included in the study. They were divided into those who sought help (n = 256) and those who did not (n = 1675), and differences between them were assessed. RESULTS: Only 13% of young people needing help for psychological problems consulted for that reason and this rate was positively associated with the frequency of consultations to the GP. However, 80% of young people who did not consult for psychological problems visited their GP at least once during the previous year. Being older or a student, having a higher depression score, or a history of suicide attempt were linked with a higher rate of help seeking. Moreover, confiding in adults positively influenced the rate of help seeking. CONCLUSION: The large majority of young people reporting psychological problems do not seek help, although they regularly consult their GP. While young people have difficulties in tackling issues about mental health, GPs could improve the situation by systematically inquiring about this issue.

Control of landslide retrogression by discontinuities: Evidence by the integration of airbone- and ground-based geophysical information

The objective of this work is to present a multitechnique approach to define the geometry, the kinematics, and the failure mechanism of a retrogressive large landslide (upper part of the La Valette landslide, South French Alps) by the combination of airborne and terrestrial laser scanning data and ground-based seismic tomography data. The advantage of combining different methods is to constrain the geometrical and failure mechanism models by integrating different sources of information. Because of an important point density at the ground surface (4. 1 points m?2), a small laser footprint (0.09 m) and an accurate three-dimensional positioning (0.07 m), airborne laser scanning data are adapted as a source of information to analyze morphological structures at the surface. Seismic tomography surveys (P-wave and S-wave velocities) may highlight the presence of low-seismic-velocity zones that characterize the presence of dense fracture networks at the subsurface. The surface displacements measured from the terrestrial laser scanning data over a period of 2 years (May 2008?May 2010) allow one to quantify the landslide activity at the direct vicinity of the identified discontinuities. An important subsidence of the crown area with an average subsidence rate of 3.07 m?year?1 is determined. The displacement directions indicate that the retrogression is controlled structurally by the preexisting discontinuities. A conceptual structural model is proposed to explain the failure mechanism and the retrogressive evolution of the main scarp. Uphill, the crown area is affected by planar sliding included in a deeper wedge failure system constrained by two preexisting fractures. Downhill, the landslide body acts as a buttress for the upper part. Consequently, the progression of the landslide body downhill allows the development of dip-slope failures, and coherent blocks start sliding along planar discontinuities. The volume of the failed mass in the crown area is estimated at 500,000 m3 with the sloping local base level method.

Simulación de departamentos de urgencias empleando un modelo basado en agentes

Los servicios de salud son sistemas muy complejos, pero de alta importancia, especialmente en algunos momentos críticos, en todo el mundo. Los departamentos de urgencias pueden ser una de las áreas más dinámicas y cambiables de todos los servicios de salud y a la vez más vulnerables a dichos cambios. La mejora de esos departamentos se puede considerar uno de los grandes retos que tiene cualquier administrador de un hospital, y la simulación provee una manera de examinar este sistema tan complejo sin poner en peligro los pacientes que son atendidos. El objetivo de este trabajo ha sido el modelado de un departamento de urgencias y el desarrollo de un simulador que implementa este modelo con la finalidad de explorar el comportamiento y las características de dicho servicio de urgencias. El uso del simulador ofrece la posibilidad de visualizar el comportamiento del modelo con diferentes parámetros y servirá como núcleo de un sistema de ayuda a la toma de decisiones que pueda ser usado en departamentos de urgencias. El modelo se ha desarrollado con técnicas de modelado basado en agentes (ABM) que permiten crear modelos funcionalmente más próximos a la realidad que los modelos de colas o de dinámicas de sistemas, al permitir la inclusión de la singularidad que implica el modelado a nivel de las personas. Los agentes del modelo presentado, descritos internamente como máquinas de estados, representan a todo el personal del departamento de urgencias y los pacientes que usan este servicio. Un análisis del modelo a través de su implementación en el simulador muestra que el sistema se comporta de manera semejante a un departamento de urgencias real.