It is henceforth a commonplace; the science-fiction would be a refractory genre by nature against the definitive assimilation to the literary mainstream. We can say that the usual thematic of the genre, to which is added the irresistible propensity to prospect the future in all its forms, immunizes the SF against the “academic confinement” to the benefit of other forms of confinement. Indeed, the SF belongs to the great family of the paraliterature where the more or less listed subgenres are waiting to receive a likely definition. Popular genre which relies on a remarkable poetic, the SF is an open place to the imagination, to the verbal and the figurative creativity. It owns itself its subgenres, among other things, the space opera which was, in a way, the original matrix of the speculative fiction and of its contemporary imitators. The Sternberg’s work did not have a special vocation to feed the already rich world of the science-fiction. It constitutes however a new step liable to bring a touch of self-reflexivity, we will notice that, to the history of this genre. French: “Le Navigateur” de Jacques Sternberg ou la phylogenese parodiee du space opera C’est dorenavant un lieu commun, la science-fiction serait un genre par nature refractaire a l’assimilation definitive au mainstream litteraire. Nous dirons que les thematiques habituelles du genre, auxquelles viennent se meler l’irresistible propension a prospecter l’avenir sous toutes ses formes, immunisent la SF contre “l’enfermement academique” au profit d’un enfermement d’un autre genre. En effet, celle-ci appartient, comme on le sait, a la grande famille de la paralitterature ou se cotoient les sous-genres plus ou moins repertories en attente de recevoir un semblant de definition. Genre populaire s’appuyant sur une poetique singuliere, la SF est un lieu ouvert a l’imagination, a la creativite verbale et figurative. Elle possede elle-meme ses sous-genres, entre autres, le space opera qui fut en quelque sorte la matrice originelle de la fiction speculative et de ses emules contemporaines. L’oeuvre sternbergienne n’eut guere pour vocation de nourrir le repertoire deja riche de la science-fiction. Elle constitue neanmoins une etape non repertoriee susceptible d’apporter, nous le constaterons, une touche d’auto-reflexivite a l’histoire du genre.Keywords: Jacques Sternberg, Nouvelle, Science-Fiction, Space Opera, Aventure, Fiction Speculative

Background: Cement space is necessary for seatabillity and fitness of cast crowns, but can affect crown's retention. In this study the interrelationship between them was investigated via die spacing.Materials and Method: For evaluating the effect of die spacing (cement space) on crown retention after cementation, 50 similar machined metallic dies were prepared and divided into five groups and coated with 0.2, 4, 6, 8 layers of paint-on standard die spacer, respectively. Cast crowns. Were fabricated on the dies using base metal alloys, and then cemented with zinc phosphate cement under a constant load of 5kg for 10 minutes. The samples were started in distilled water for 48 hours. Then the force required to remove each crown from the die was measured with instron.Results: Statistical analysis revealed a significant increase in the force required (crown retention) by adding layers of die spacer (p<0.05).Conclusion: Because retention didn't show any significant increase with more than 4 layers of die spacer, so optimum thickness of die spacer (or cement space produced) is suggested to be 4 layers equal to 40 microns.

Purpose: The aim of this study was to compare the effects of A) a flame heated endo plugger, B) GatesGlidden drills and C) GPX drills on the apical seal for the purpose of post space preparation. Materials & Methods: The crowns of sixty six extracted maxillary central teeth were removed from CEJ by a diamond disc and the root canals were prepared and obturated with guttapercha and sealer (Ah26) using lateral condensation technique. Six teeth were used as positve and negative control groups and the other sixty teeth were divided into 3 groups, each group containing 20 teeth. The post space in these 3 groups was made by either A/a hot plugger, B/# 3or# 4 Gates glidden drills and C/# 40 or # 50 GPX drills and apical dye leakage in each group was measured by stereomicroscope and the Anova test was used to compare the mean amount of dye leakage between groups.Results: Between these 3 groups, the minimal mean dye leakage was related to the hot plugger group and the maximum mean leakage was observed in Gates glidden drill group. There was significant statistical difference between the groups (P=0.005).Conclusion: The GPX drills for the purpose of post space preparation affect apical seal less than Gates glidden drills.

Background & Aim: There are several methods for determination of occlusal vertical dimension. The vertical dimension of rest position, interocclusal distance and closest speaking space are two important methods. The purpose of this study was comparison the variability of interocclusal distance and closest speaking space in denture wearers.Method &Materials: The subjects were 34 edentulous patients (18 males & 16 females with mean age of 56) who had received complete dentures in the prosthodontics department of Isfahan dental school. They had good residual ridges. The dentures had correct clinical vertical dimension with 1-2mm overjet and 0.5 -1mm overbite. There was no evidence of neuromuscular and TMJ problems. The TOM guage was used for measuring the vertical dimension of rest position and «S» position.Results: The results showed that the mean and standard deviation of interocclusal distance were smaller than closest speaking space. Paired T-test and Levene's test were used for statistical analysis. There was a statistically difference between interocclusal distance and closest speaking space, so the interocclusal distance was less variable than closest speaking space (P<0.05).Conclusion: The closest speaking space during S position is affected by the occlusion, vertical and horizontal overlap of anterior teeth. These factors are up to dentist's judgement in complete denture and can influence the variability of vertical dimension of S position. Because of this variability it is recommended to use several methods for determining of vertical dimension.

Introduction The structure and shape of the historic core in many ancient cities of Iran were mainly disregarded in urban development trends. This has led to some problems of inconsistencies with new physical changes, lack of appropriate link with existing structural network and spatial isolation. The main structure of a city is a set of interrelated and continuous urban spaces encompassing the essential elements and main activities of the city. Understanding this structure requires a thorough analysis of all aspects of the phenomenon. Among the theories dealing with the urban spatial structure, the space Syntax theory has useful capabilities to address the problems. In the past decades, Urmia has experienced major changes in its traditional structure and also the historic core of this city like many other cities. Under the influence of hasty actions, this has undergone numerous difficulties. The objective of this paper is to identify and analyze the growth process of urban development of Urmia and its structure. Thus, we have addressed the effects of contemporary physical changes on the spatial structure of the historical district and the relationship between key elements of the historical structure to investigate the spatial coherence. We have used the Space Syntax theory to analyze the structure and spatial configuration of the city. According to selected parameters for analyzing the urban structure during various periods, the main goal is to study the changes of values and the performance of historical texture through the analysis of the elements of urban spatial structure and the output spatial parameters of this theory. Methodology This is a descriptive, quantitative and a comparative research in methodology. In this study, the Urmia city and its historical district is analyzed with the Space Syntax method using AutoCAD, Depth map and ArcGIS. In order to study the spatial structural changes of Urmia city and its impact on the spatial structure of the historic core of the town, based on available documents and maps, four main periods of physical evolution of the city, i. e., the years of 1933, 1976, 1994, 2016, have been considered for analysis of its structure through the space syntax theory. After the parameters and analytical maps of the space syntax were analyzed by the comparison of the periods, validity changes have been assessed. These are considered as the most important concepts in this method to study four factors of coherence and coordination of the structure of the historical district, assessment of value and importance of historical orders and its main elements and the manner of distributing activities in the range. Results and discussion The results of this research have revealed that the lowest deviation and the highest amount of affiliation and thus urban coherence is related to 1933 following physical changes of the city with reduction of structural integrity. The values of urban affiliation in historical range during the four periods indicate that the average historical context of the city is less than that of the city affiliation. This implies that the internal structure of this area has not been related to these axes. The changes in the values of the inter-connection of the main historical orders have been studied for structural analysis of the main axes. The spatial physical value of the axis is degraded to inferior position, because both the average value of the interconnection of each axes and also the average difference between the axes are declined compared with previous periods. In the subsequent analysis, public spaces containing historical market and the main fields of the historical core (The Velayat-faqih and Ayalat square) and the central mosque of the city have been considered as the main religious element in the texture. Integration of factors shows that until 2016, the extent of the interconnection of the main historical spaces has been reduced as one of the major city activity centers. The next criterion examines the overlaps of the most integration axes with the active and attractive users of the cities and their relationship. Conclusion According to the results of this research, it was revealed that the performance and historical coherence and its relation to the structure of the city have been reduced under the influence of physical changes over the time. The internal structure of this range could not be mingled with the overall structure of city. A large part of identity values and physical texture affected by these changes have been lost. The spatial continuity of main elements and the functional significance of historical orders have been weakened under the influence of the changes. This indicates that the rapid physical changes in the recent years had negative effects on the spatial structure of historical range of Urmia city.

The aim of this study was to determine the effect of SPACE software on reducing addiction and cell phone dependence in young people. A 25-year-old person with cell phone addiction and dependence was identified by a mobile phone addiction questionnaire (2014). Subjects were intervened with SPACE software for 12 sessions using a single subject research design (ABA) and then followed up for three weeks after the intervention. Finally, the data obtained in the baseline, intervention and follow-up stages were analyzed using visual diagram analysis, percentage of overlapping data (PAND), effect size and recovery percentage. The results showed that using SPACE software reduces addiction and cell phone dependence.