Nuclear alterations in nasal mucosa epithelial cells of students exposed to formaldehyde

Introduction: Formaldehyde is a compound with a wide range and is commonly used in anatomy and pathology laboratories. At room temperature is quickly volatilized to a pungent and suffocating gas and its inhalation has been correlated to nuclear alterations in different tissues. We aimed to investigate whether exposure to this compound was correlated with the appearance of cytotoxic and genotoxic features in the nasal epithelial cells of students enrolled in a human anatomy course. Material and Methods: This prospective study collected periodically nasal cells from mucosa of 17 volunteers from two different undergraduate programs with different workloads of practical lessons in an anatomy laboratory, 30 and 90 hours per semester. Cells were staining according to Feulgen method and nuclear morphology was analyzed to detect possible damage. Dunn's post hoc test was used in the statistical analysis. Pearson's correlation was performed for gender, age and questionnaire responses. Results: Epithelial cells showed indicators of cytotoxicity and mutagenicity. Students with a more extensive workload in anatomy laboratory displayed a more severe profile with an increase in karyorrhexis (p < 0.05) over time. The micronucleus analysis showed difference between first and second collection (p < 0.01), although it was not maintained over the time. Students with a less extensive workload display no differences in most of cytological features. Despite karyorrhexis was present in a greater number of cells, for this group no significant difference was observed between any range. The same was observed to karyolysis and micronucleus (p > 0.05). Conclusion: Individuals exposed for short periods of time to formaldehyde are subject to the toxic action of this gas. Karyorrhexis was the most frequently observed cytotoxic feature and micronucleus showed an increase between the first time point. The patterns observed between the student's groups suggest a negative effect due to exposure time.

Les droits réels et personnels sur les titres détenus auprès d'un intermédiaire : analyse comparative en droit québécois interne et international privé

Les transactions sur les valeurs mobilières ainsi que leur mise en garantie se font bien au-delà des frontières nationales. Elles impliquent une multitude d’intervenants, tels que l’émetteur, un grand nombre d’intermédiaires disposés en structure pyramidale, un ou des investisseurs et, bien évidemment, les bénéficiaires desdites valeurs mobilières ou garanties. On peut aussi signaler l’existence de nombreux portefeuilles diversifiés contenant des titres émis par plusieurs émetteurs situés dans plusieurs états. Toute la difficulté d’une telle diversité d’acteurs, de composantes financières et juridiques, réside dans l’application de règles divergentes et souvent conflictuelles provenant de systèmes juridiques d’origines diverses (Common Law et civiliste). De nombreux juristes, de toutes nationalités confondues, ont pu constater ces dernières années que les règles de création, d’opposabilité et de réalisation des sûretés, ainsi que les règles de conflit de lois qui aident à déterminer la loi applicable à ces différentes questions, ne répondaient plus adéquatement aux exigences juridiques nationales dans un marché financier global, exponentiel et sans réelles frontières administratives. Afin de résoudre cette situation et accommoder le marché financier, de nombreux textes de loi ont été révisés et adaptés. Notre analyse du droit québécois est effectuée en fonction du droit américain et canadien, principales sources du législateur québécois, mais aussi du droit suisse qui est le plus proche de la tradition civiliste québécoise, le tout à la lueur de la 36e Convention de La Haye du 5 juillet 2006 sur la loi applicable à certains droits sur des titres détenus auprès d'un intermédiaire. Par exemple, les articles 8 et 9 du Uniform Commercial Code (UCC) américain ont proposé des solutions modernes et révolutionnaires qui s’éloignent considérablement des règles traditionnelles connues en matière de bien, de propriété, de sûreté et de conflits de lois. Plusieurs autres projets et instruments juridiques dédiés à ces sujets ont été adoptés, tels que : la Loi uniforme sur le transfert des valeurs mobilières (LUTVM) canadienne, qui a été intégrée au Québec par le biais de la Loi sur le transfert de valeurs mobilières et l’obtention de titres intermédiés, RLRQ, c.T-11.002 (LTVMQ) ; la 36e Convention de La Haye du 5 juillet 2006 sur la loi applicable à certains droits sur des titres détenus auprès d'un intermédiaire; la Loi fédérale sur le droit international privé (LDIP) suisse, ainsi que la Loi fédérale sur les titres intermédiés (LTI) suisse. L’analyse de ces textes de loi nous a permis de proposer une nouvelle version des règles de conflit de lois en matière de sûretés et de transfert des titres intermédiés en droit québécois. Cette étude devrait susciter une réflexion profonde du point de vue d’un juriste civiliste, sur l’efficacité des nouvelles règles québécoises de sûretés et de conflit de lois en matière de titres intermédiés, totalement inspirées des règles américaines de Common Law. Un choix qui semble totalement ignorer un pan du système juridique civiliste et sociétal.

Seismic waveform inversion for core-mantle boundary topography

International audience

Savani: A variable resolution whole-mantle model of anisotropic shear velocity variations based on multiple data sets

International audience

Statistical Analysis of Sea Surface Temperature and Chlorophyll-a Concentration Patterns in the Gulf of Tadjourah (Djibouti)

The sea surface temperature (SST) and chlorophyll-a concentration (CHL-a) were analysed in the Gulf of Tadjourah from two set of 8-day composite satellite data, respectively from 2008 to 2012 and from 2005 to 2011. A singular spectrum analysis (SSA) shows that the annual cycle of SST is strong (74.3% of variance) and consists of warming (April-October) and cooling (November-March) of about 2.5C than the long-term average. The semi-annual cycle captures only 14.6% of temperature variance and emphasises the drop of SST during July-August. Similarly, the annual cycle of CHL-a (29.7% of variance) depicts high CHL-a from June to October and low concentration from November to May. In addition, the first spatial empirical orthogonal function (EOF) of SST (93% of variance) shows that the seasonal warming/cooling is in phase across the whole study area but the southeastern part always remaining warmer or cooler. In contrast to the SST, the first EOF of CHL-a (54.1% of variance) indicates the continental shelf in phase opposition with the offshore area in winter during which the CHL-a remains sequestrated in the coastal area particularly in the south-east and in the Ghoubet Al-Kharab Bay. Inversely during summer, higher CHL-a quantities appear in the offshore waters. In order to investigate processes generating these patterns, a multichannel spectrum analysis was applied to a set of oceanic (SST, CHL-a) and atmospheric parameters (wind speed, air temperature and air specific humidity). This analysis shows that the SST is well correlated to the atmospheric parameters at an annual scale. The windowed cross correlation indicates that this correlation is significant only from October to May. During this period, the warming was related to the solar heating of the surface water when the wind is low (April-May and October) while the cooling (November-March) was linked to the strong and cold North-East winds and to convective mixing. The summer drop in SST followed by a peak of CHL-a, seems strongly correlated to the upwelling. The second EOF modes of SST and CHL-a explain respectively 1.3% and 5% of the variance and show an east-west gradient during winter that is reversed during summer. This work showed that the seasonal signals have a wide spatial influence and dominate the variability of the SST and CHL-a while the east-west gradient are specific for the Gulf of Tadjourah and seem induced by the local wind modulated by the topography.

Validation of age determination using otoliths of the European anchovy (Engraulis encrasicolus L.) in the Bay of Biscay

Validation of the age determination procedure using otoliths of European anchovy in the Bay of Biscay was achieved by monitoring very strong year-classes in successive spring catches and surveys, as well as the seasonal occurrence of edge types. Historical corroboration of the ageing method was obtained by cross-correlation between successive age groups by year-classes in catches and surveys (1987–2013). Summary annual growth in length is also presented. Yearly annuli consist of a hyaline zone (either single or composite) and a wide opaque zone, disrupted occasionally by some typical checks (mainly at age-0 and age-1 at peak spawning time). Age determination, given a date of capture, requires knowledge of the typical annual growth pattern of otoliths, their seasonal edge formation by ages and the most typical checks. Most opaque growth occurs in summer and is minimal (translucent) in winter. Opaque zone formation begins earlier in younger fish (in spring), and this helps distinguish age-1 from age-2+.

Estudo comparativo entre técnicas de aprendizado de máquina para estimação de risco de crédito

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Economia, Administração e Contabilidade, Programa de Pós-Graduação em Administração, 2016.

Empirical evidence of S-curves in the Colombian

The Marshall-Lerner condition, the J-curve and S-curve have emerged as theoretical and empirical foundations developed for the study of the interaction between exchange rates and international patterns of bilateral trade -- They have a significant bearing on thedevelopment of public policy, and are of equal interest to the academic and professional communities -- The most recently developed of these theories, the S-Curve, is named after the theorized short-run behavior to be found in the cross-correlation function of the real exchange rate and the trade balance -- Considering this theoretical context, the paper seeks empirical evidence of the existence of the S-Curve in the bilateral trade in commodity and non-commodity goods between Colombia and the United States and Venezuela, its main trading partners, for the yearly quarters between 1994:1 and 2009:4

Is the supply of long-term debt independent of the term premia? Evidence from Portugal

An important assumption in the statistical analysis of the financial market effects of the central bank’s large scale asset purchase program is that the "long-term debt stock variables were exogenous to term premia". We test this assumption for a small open economy in a currency union over the period 2000M3 to 2015M10, via the determinants of short- term financing relative to long-term financing. Empirical estimations indicate that the maturity composition of debt does not respond to the level of interest rate or to the term structure. These findings suggest a lower adherence to the cost minimization mandate of debt management. However, we find that volatility and relative market size respectively decrease and increase short-term financing relative to long-term financing, while it decreases with an increase in government indebtedness.

Tensões e contradições do processo de construção das diretrizes para a politica pública de educação infantil do campo

Tese (doutorado)—Universidade de Brasília, Faculdade de Educação, Programa de Pós-Graduação em Educação, 2016.

LA CRISIS FINANCIERA: ¿ESTAFA, MALA GESTIÓN EMPRESARIAL, MAL MANEJO MACROECONÓMICO O UNA FALTA DE REGULACIONES? DE NUEVO LAS ENSEÑANZAS

Resumen La intensificación de la crisis a nivel global, luego de la bancarrota de Lehman Brothers en septiembre del 2008, ha provocado que el actual entorno económico y financiero sea complicado para la economía mundial, el sector financiero a nivel global y para los bancos centrales. La actual crisis deriva de muchas causas; no obstante las principales son tres: primero, aspectos macroeconómicos; segundo, la inadecuada regulación de los entes encargados, y tercero, los reguladores estimularon el rápido crecimiento de los derivados en el mercado OTC. Abstract The amplification of the global financial crisis, following the bankruptcy of Lehman Brothers in September 2008, has made the present economic and financial environment a not easy time for the world economy, the global financial system and for central banks. There are many causes from the recent financial crisis. Main could be three. First, there were macroeconomic components. Second, the inadequate oversight/regulation provided by financial market regulators. And third, federal regulators have actively encouraged the rapid growth of over-the-counter (OTC) derivatives and securities by all types of financial institutions.

Avoiding staff removal stage in optical music recognition: application to scores written in white mensural notation

Staff detection and removal is one of the most important issues in optical music recognition (OMR) tasks since common approaches for symbol detection and classification are based on this process. Due to its complexity, staff detection and removal is often inaccurate, leading to a great number of errors in posterior stages. For this reason, a new approach that avoids this stage is proposed in this paper, which is expected to overcome these drawbacks. Our approach is put into practice in a case of study focused on scores written in white mensural notation. Symbol detection is performed by using the vertical projection of the staves. The cross-correlation operator for template matching is used at the classification stage. The goodness of our proposal is shown in an experiment in which our proposal attains an extraction rate of 96 % and a classification rate of 92 %, on average. The results found have reinforced the idea of pursuing a new research line in OMR systems without the need of the removal of staff lines.

Efficient representation of texture details in medical images by fusion of Ripplet and DDCT transformed images

Purpose: To evaluate and compare the performance of Ripplet Type-1 transform and directional discrete cosine transform (DDCT) and their combinations for improved representation of MRI images while preserving its fine features such as edges along the smooth curves and textures. Methods: In a novel image representation method based on fusion of Ripplet type-1 and conventional/directional DCT transforms, source images were enhanced in terms of visual quality using Ripplet and DDCT and their various combinations. The enhancement achieved was quantified on the basis of peak signal to noise ratio (PSNR), mean square error (MSE), structural content (SC), average difference (AD), maximum difference (MD), normalized cross correlation (NCC), and normalized absolute error (NAE). To determine the attributes of both transforms, these transforms were combined to represent the entire image as well. All the possible combinations were tested to present a complete study of combinations of the transforms and the contrasts were evaluated amongst all the combinations. Results: While using the direct combining method (DDCT) first and then the Ripplet method, a PSNR value of 32.3512 was obtained which is comparatively higher than the PSNR values of the other combinations. This novel designed technique gives PSNR value approximately equal to the PSNR’s of parent techniques. Along with this, it was able to preserve edge information, texture information and various other directional image features. The fusion of DDCT followed by the Ripplet reproduced the best images. Conclusion: The transformation of images using Ripplet followed by DDCT ensures a more efficient method for the representation of images with preservation of its fine details like edges and textures.

Impacto de fusões e aquisições na eficiência e produtividade de operadoras de infraestruturas do mercado financeiro e sistemas de negociação

Dissertação (mestrado)—Universidade de Brasília, Departamento de Administração, Programa de Pós-graduação em Administração, 2016.

Principaux obstacles à la décision d’investissement des firmes en Afrique

Quelles sont les contraintes auxquelles font face les firmes africaines ? Cette étude a pour but de cerner les principaux défis du climat des affaires africain en utilisant les données de la World Bank Enterprise Survey. Dans cette enquête, deux questions majeures ont été posées au gestionnaire de firmes : i) l’ampleur des contraintes énumérées pour leur activité et ii) la décision d’investissement durant l’année qui a précédé l’enquête. Nos résultats montrent que, pour les firmes de notre échantillon, la décision d’investissement est retardée par un ensemble d’obstacles parmi lesquelles : la corruption, l’accès difficile au marché financier, la concurrence déloyale du secteur informel et l’instabilité politique. Nous procédons ensuite à une analyse de sensibilité et de robustesse en intégrant parmi les variables de contrôle ; la taille des firmes, le secteur d’activité et leur localisation. Nos résultats montrent que les firmes de taille moyenne sont les plus vulnérables, elles sont différemment affectées selon qu’elles soient dans le secteur des manufactures ou celui des services et les compagnies situées en Afrique centrale sont très peu affectées par ces contraintes.