Vestibular Schwannoma: The Evolution of Hearing and Tumor Size in Natural Course and after Treatment by LINAC Stereotactic Radiosurgery.

OBJECTIVE: To review the natural course of tumor size and hearing during conservative management of 151 patients with unilateral vestibular schwannoma (VS), and to evaluate the same parameters for the part of the group (n = 84) who were treated by LINAC stereotactic radiosurgery (SRS). METHODS: In prospectively collected data, patients underwent MRI and complete audiovestibular tests at inclusion, during the conservative management period and after SRS. Hearing was graded according to the Gardner-Robertson (GR) scale and tumor size according to Koos. Statistics were performed using Kaplan-Meier survival analysis and multivariate analyses including linear and logistic regression. Specific insight was given to patients with serviceable hearing. RESULTS: During the conservative management period (mean follow-up time: 24 months, range: 6-96), the annual risk of GR class degradation was 6% for GRI and 15% for GR II patients. Hearing loss as an initial symptom was highly predictive of further hearing loss (p = 0.003). Tumor growth reached 25%. For SRS patients, functional hearing preservation was 51% at 1 year and 36% at 3 years. Tumor control was 94 and 91%, respectively. CONCLUSION: In VS patients, hearing loss at the time of diagnosis is a predictor of poorer hearing outcome. LINAC SRS is efficient for tumor control. Patients who preserved their pretreatment hearing presented less hearing loss per year after SRS than before treatment, suggesting a protective effect of SRS when cochlear function can be preserved.

Vestibular schwannoma : the evolution of hearing and tumor size in natural course and after treatment by Linac stereotactic radiosurgery

Objectif : D'analyser l'évolution naturelle de la taille de la tumeur et de l'audition chez 151 patients avec schwannome vestibulaire (VS) en suivi et d'évaluer les mêmes paramètres pour une partie du group traité par Radiochirurgie Stéréotaxique Linac (SRS). Méthodes: Etude prospective des patients bilantés par IRM et tests audio-vestibulaires à l'inclusion, pendant la période du suivi et après SRS. L'audition a été gradé selon l'échelle de Gardner-Robertson (GR) et la taille tumorale selon l'échelle de Koos. L'analyse statistique inclut l'analyse de survie de Kaplan-Meier, analyse multivariée avec régression linéaire et logistique. Les patients avec une audition utile ont étés spécifiquement analysés. Résultats: Pendant la période du suivi (moyenne 24 mois, déviation 6-96), le risqué annuel de dégradation de la classe GR était 6% pour les patients GRI et 15% pour les GRII. La perte auditive comme symptôme initial était un facteur signifïcativement prédictif pour une aggravation auditive ultérieure (p=0.003). La croissance tumorale était de 25% à la dernière observation pendant le suivi. Pour les patients traités par Linac, la préservation d'une audition utile était 51% à 1 an et 36% à 3 ans. Le contrôle tumoral était 94 % and 91% respectivement. Conclusion: Chez les patients avec VS, la perte auditive déjà présente au diagnostique est un facteur prédictif négatif pour l'évolution de l'audition. La Radiochirurgie Stéréotaxique Linac est efficace pour le contrôle tumoral. Les patients ayant préservés leur status auditif prétraitement présentent un rythme annuel de perte auditive diminué après SRS compare à celle-ci avant le traitement. Cette constatation suggère un effet protectif potentiel de la SRS, à condition que la fonction cochléaire soit préservée.

Factors influencing the evolution of e-commerce : an empirical analysis in a developed market economy

Peer-reviewed

Emergence and development of a financial cluster: the evolution of Andorra’s banking deposits in the long-term, 1931-2007

This paper explores the origins of Andorra’s financial cluster. It shows that the free movement of currency, the protection of infant industry, and geographical concentration lie at the foundation of the cluster’s competitive advantage. Drawing on a new set of data, the paper also provides for the first time an estimate of the total deposits held by Andorra’s banks between 1931 and 2007. Based on this new information, the paper reaches the conclusion that the development of the cluster went through four distinct phases in which large companies, acting as leaders, played an important role in enhancing the cluster’s business capabilities.

An analysis of the evolution of hydrometeorological extremes in newspapers: the case of Catalonia, 1982-2006

This contribution analyzes the evolution of perception of certain natural hazards over the past 25 years in a Mediterranean region. Articles from newspapers have been used as indicator. To this end a specific Spanish journal has been considered and an ACCESS database has been created with the summarized information from each news item. The database includes data such as the location of each specific article in the newspaper, its length, the number of pictures and figures, the headlines and a summary of the published information, including all the instrumental data. The study focused on hydrometeorological extremes, mainly floods and droughts, in the northeast of the Iberian Peninsula. The number of headlines per event, trends and other data have been analyzed and compared with "measured" information, in order to identify any bias that could lead to an erroneous perception of the phenomenon. The SPI index (a drought index based on standardized accumulated precipitation) has been calculated for the entire region, and has been used for the drought analysis, while a geodatabase implemented on a GIS built for all the floods recorded in Catalonia since 1900 (INUNGAMA) has been used to analyze flood evolution. Results from a questionnaire about the impact of natural hazards in two specific places have been also used to discuss the various perceptions between rural and urban settings. Results show a better correlation between the news about drought or water scarcity and SPI than between news on floods in Catalonia and the INUNGAMA database. A positive trend has been found for non-catastrophic floods, which is explained by decrease of the perception thresholds, the increase of population density in the most flood-prone areas and changes in land use.

The evolution of post-zygotic isolation barriers by immune-triggered hybrid incompatibilities in Arabidopsis thaliana

A long-standing question in evolutionary biology is what defines a species. The biological species concept considers a species as a population of individuals that interbreeds freely and produces viable offspring. Therefore, reproductive isolation is the essence of species. Hybrid necrosis is one form of post-zygotic reproductive isolation. In this chapter, we summarize what is known to date about this phenomenon and highlight progress made in the understanding of these immune-triggered hybrid incompatibilities through our research in the plant model Arabidopsis thaliana.

The evolution of post-zygotic isolation barriers by immune-triggered hybrid incompatibilities in Arabidopsis thaliana

A long-standing question in evolutionary biology is what defines a species. The biological species concept considers a species as a population of individuals that interbreeds freely and produces viable offspring. Therefore, reproductive isolation is the essence of species. Hybrid necrosis is one form of post-zygotic reproductive isolation. In this chapter, we summarize what is known to date about this phenomenon and highlight progress made in the understanding of these immune-triggered hybrid incompatibilities through our research in the plant model Arabidopsis thaliana.

Evolver: The Evolution of The Extended EPrints Ecosystem

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Three rounds (1R/2R/3R) of genome duplications and the evolution of the glycolytic pathway in vertebrates

Affiliation: Henner Brinkmann : Département de biochimie, Faculté de médecine, Université de Montreal

The evolution of inter-genomic variation in arbuscular mycorrhizal fungi

Contexte: Les champignons mycorhiziens à arbuscules (AMF) établissent des relations symbiotiques avec la plupart des plantes grâce à leurs réseaux d’hyphes qui s’associent avec les racines de leurs hôtes. De précédentes études ont révélé des niveaux de variation génétique extrêmes pour des loci spécifiques permettant de supposer que les AMF peuvent contenir des milliers de noyaux génétiquement divergents dans un même cytoplasme. Si aucun processus de reproduction sexuée n’a jusqu’ici été observé chez ces mycorhizes, on constate cependant que des niveaux élevés de variation génétique peuvent être maintenus à la fois par l’échange de noyaux entre hyphes et par des processus fréquents de recombinaison entre noyaux. Les AMF se propagent par l’intermédiaire de spores qui contiennent chacune un échantillon d’une population initiale de noyaux hétérogènes, directement hérités du mycélium parent. À notre connaissance les AMF sont les seuls organismes qui ne passent jamais par un stade mononucléaire, ce qui permet aux noyaux de diverger génétiquement dans un même cytoplasme. Ces aspects singuliers de la biologie des AMF rendent l’estimation de leur diversité génétique problématique. Ceci constitue un défi majeur pour les écologistes sur le terrain mais également pour les biologistes moléculaires dans leur laboratoire. Au-delà même des problématiques de diversité spécifique, l’amplitude du polymorphisme entre noyaux mycorhiziens est mal connue. Le travail proposé dans ce manuscrit de thèse explore donc les différents aspects de l’architecture génomique singulière des AMF. Résultats L’ampleur du polymorphisme intra-isolat a été déjà observée pour la grande sous-unité d’ARN ribosomal de l’isolat Glomus irregulare DAOM-197198 (précédemment identifié comme G. intraradices) et pour le gène de la polymerase1-like (PLS) de Glomus etunicatum isolat NPI. Dans un premier temps, nous avons pu confirmer ces résultats et nous avons également pu constater que ces variations étaient transcrites. Nous avons ensuite pu mettre en évidence la présence d’un goulot d’étranglement génétique au moment de la sporulation pour le locus PLS chez l’espèce G. etunicatum illustrant les importants effets d’échantillonnage qui se produisaient entre chaque génération de spore. Enfin, nous avons estimé la différentiation génétique des AMF en utilisant à la fois les réseaux de gènes appliqués aux données de séquençage haut-débit ainsi que cinq nouveaux marqueurs génomiques en copie unique. Ces analyses révèlent que la différenciation génomique est présente de manière systématique dans deux espèces (G. irregulare et G. diaphanum). Conclusions Les résultats de cette thèse fournissent des preuves supplémentaires en faveur du scénario d’une différenciation génomique entre noyaux au sein du même isolat mycorhizien. Ainsi, au moins trois membres du genre Glomus, G. irregulare, G. diaphanum and G. etunicatum, apparaissent comme des organismes dont l’organisation des génomes ne peut pas être décrit d’après un modèle Mendélien strict, ce qui corrobore l’hypothèse que les noyaux mycorhiziens génétiquement différenciés forment un pangenome.

Explaining the evolution of educational attainment in the U.S.

We study the evolution of educational attainment of the 1932–1972 cohorts using a calibrated model of investment in human capital with heterogeneous learning ability. The inter-cohort variation in schooling is driven by changes in skill prices, tuition, and education quality over time, and average learning ability across cohorts. A version of the model with static expectations is successful in accounting for the main patterns in the data. Rising skill prices for college explain the rapid increase in college graduation till the 1948 cohort. The measured decline in average learning ability contributes to explain the stagnation in college graduation between the 1948 and 1972 cohorts.

Hydrogeology and hydrochemistry of the aquifer systems of Kuttanad area, Kerala: Their role in understanding the evolution of groundwaters

This is an attempt to understand the important factors that control the occurrence, development and hydrochemical evolution of groundwater resources in sedimentary multi aquifer systems. The primary objective of this work is an integrated study of the hydrogeology and hydrochemistry with a view to elucidate the hydrochemical evolution of groundwater resources in the aquifer systems. The study is taken up in a typical coastal sedimentary aquifer system evolved under fluvio-marine environment in the coastal area of Kerala, known as the Kuttanad. The present study has been carried out to understand the aquifer systems, their inter relationships and evolution in the Kuttanad area of Kerala. The multi aquifer systems in the Kuttanad basin were formed from the sediments deposited under fluvio-marine and fluvial depositional environments and the marine transgressions and regressions in the geological past and palaeo climatic conditions influenced the hydrochemical environment in these aquifers. The evolution of groundwater and the hydrochemical processes involved in the formation of the present day water quality are elucidated from hydrochemical studies and the information derived from the aquifer geometry and hydraulic properties. Kuttanad area comprises of three types of aquifer systems namely phreatic aquifer underlain by Recent confined aquifer followed by Tertiary confined aquifers. These systems were formed by the deposition of sediments under fluvio-marine and fluvial environment. The study of the hydrochemical and hydraulic properties of the three aquifer systems proved that these three systems are separate entities. The phreatic aquifers in the area have low hydraulic gradients and high rejected recharge. The Recent confined aquifer has very poor hydraulic characteristics and recharge to this aquifer is very low. The Tertiary aquifer system is the most potential fresh water aquifer system in the area and the groundwater flow in the aquifer is converging towards the central part of the study area (Alleppey town) due to large scale pumping of water for water supply from this aquifer system. Mixing of waters and anthropogenic interferences are the dominant processes modifying the hydrochemistry in phreatic aquifers. Whereas, leaching of salts and cation exchange are the dominant processes modifying the hydrochemistry of groundwater in the confined aquifer system of Recent alluvium. Two significant chemical reactions modifying the hydrochemistry in the Recent aquifers are oxidation of iron in ferruginous clays which contributes hydrogen ions and the decomposition of organic matter in the aquifer system which consumes hydrogen ions. The hydrochemical environment is entirely different in the Tertiary aquifers as the groundwater in this aquifer system are palaeo waters evolved during various marine transgressions and regressions and these waters are being modified by processes of leaching of salts, cation exchange and chemical reactions under strong reducing environment. It is proved that the salinity observed in the groundwaters of Tertiary aquifers are not due to seawater mixing or intrusion, but due to dissolution of salts from the clay formations and ion exchange processes. Fluoride contamination in this aquifer system lacks a regional pattern and is more or less site specific in natureThe lowering of piezometric heads in the Tertiary aquifer system has developed as consequence of large scale pumping over a long period. Hence, puping from this aquifer system is to be regulated as a groundwater management strategy. Pumping from the Tertiary aquifers with high capacity pumps leads to well failures and mixing of saline water from the brackish zones. Such mixing zones are noticed from the hydrochemical studies. This is the major aquifer contamination in the Tertiary aquifer system which requires immediate attention. Usage of pumps above 10 HP capacities in wells taping Tertiary aquifers should be discouraged for sustainable development of these aquifers. The recharge areas need to be identified precisely for recharging the aquifer systems throughartificial means.

INFO2009 The Evolution of Business Models (an audio podcast) Group 5: Team Moreau

An irreverent sideways look at new business models and their effect on the world around us. Designed with Years 9 and 10 in mind.

Small-area variation in health care affecting the choice of cesarean delivery: the case of a Colombian health insurer

In the midst of health care reform, Colombia has succeeded in increasing health insurance coverage and the quality of health care. In spite of this, efficiency continues to be a matter of concern, and small-area variations in health care are one of the plausible causes of such inefficiencies. In order to understand this issue, we use individual data of all births from a Contributory-Regimen insurer in Colombia. We perform two different specifications of a multilevel logistic regression model. Our results reveal that hospitals account for 20% of variation on the probability of performing cesarean sections. Geographic area only explains 1/3 of the variance attributable to the hospital. Furthermore, some variables from both demand and supply sides are found to be also relevant on the probability of undergoing cesarean sections. This paper contributes to previous research by using a hierarchical model and by defining hospitals as cluster. Moreover, we also include clinical and supply induced demand variables.