1,721,061 research outputs found
Social memory, evidence, and conflict
No full textThis paper examines an equilibrium model of social memory - a society's vicarious beliefs about its past. We show that incorrect social memory is a key ingredient in creating and perpetuating destructive conflicts.We analyze an infinite-horizon model in which two countries face off each period in a game of conflict characterized by the possibility of mutually destructive " all out war" that yields catastrophic consequences for both sides. Each country is inhabited by a dynastic sequence of individuals. Each individual cares about future individuals in the same country, and can communicate with the next generation of their countrymen using private messages. Social memory is based on these messages, and on physical evidence - a sequence of imperfectly informative public signals of past behavior. We find that if the future is sufficiently important for all individuals, then regardless of the precision of physical evidence from the past there is an equilibrium in which the two countries engage in all out war with arbitrarily high frequency, an outcome that cannot arise in the standard repeated game. In our construction, each new generation " repeats the mistakes" of its predecessors, leading to an endless cycle of destructive behavior.Surprisingly, we find that degrading the quality of information that individuals have about current decisions may " improve" social memory. This in turn ensures that arbitrarily frequent all out wars cannot occur. © 2009 Elsevier Inc
A "super" folk theorem for dynastic repeated games
No full textWe analyze dynastic repeated games. These are repeated games in which the stage game is played by successive generations of finitely-lived players with dynastic preferences. Each individual has preferences that replicate those of the infinitely-lived players of a standard discounted infinitely-repeated game. Individuals live one period and do not observe the history of play that takes place before their birth, but instead create social memory through private messages received from their immediate predecessors. Under mild conditions, when players are sufficiently patient, all feasible payoff vectors (including those below the minmax of the stage game) can be sustained by sequential equilibria of the dynastic repeated game with private communication. In particular, the result applies to any stage game with n ≥ 4 players for which the standard Folk Theorem yields a payoff set with a non-empty interior. We are also able to characterize fully the conditions under which a sequential equilibrium of the dynastic repeated game can yield a payoff vector not sustainable as a subgame perfect equilibrium of the standard repeated game. For this to be the case it must be that the players' equilibrium beliefs violate a condition that we term "inter-generational agreement." © 2007 Springer-Verlag
Characterization and morphological methods for oral biofilm visualization: where are we nowadays?
No full textThe oral microbiome represents an essential component of the oral ecosystem whose symbiotic relationship contributes to health maintenance. The biofilm represents a state of living of microorganisms surrounding themselves with a complex and tridimensional organized polymeric support and defense matrix. The substrates where the oral biofilm adhere can suffer from damages due to the microbial community metabolisms. Therefore, microbial biofilm represents the main etiological factor of the two pathologies of dental interest with the highest incidence, such as carious pathology and periodontal pathology. The study, analysis, and understanding of the characteristics of the biofilm, starting from the macroscopic structure up to the microscopic architecture, appear essential. This review examined the morphological methods used through the years to identify species, adhesion mechanisms that contribute to biofilm formation and stability, and how the action of microbicidal molecules is effective against pathological biofilm. Microscopy is the primary technique for the morphological characterization of biofilm. Light microscopy, which includes the stereomicroscope and confocal laser microscopy (CLSM), allows the visualization of microbial communities in their natural state, providing valuable information on the spatial arrangement of different microorganisms within the biofilm and revealing microbial diversity in the biofilm matrix. The stereomicroscope provides a three-dimensional view of the sample, allowing detailed observation of the structure, thickness, morphology, and distribution of the various species in the biofilm while CLSM provides information on its three-dimensional architecture, microbial composition, and dynamic development. Electron microscopy, scanning (SEM) or transmission (TEM), allows the high-resolution investigation of the architecture of the biofilm, analyzing the bacterial population, the extracellular polymeric matrix (EPS), and the mechanisms of the physical and chemical forces that contribute to the adhesion of the biofilm to the substrates, on a nanometric scale. More advanced microscopic methodologies, such as scanning transmission electron microscopy (STEM), high-resolution transmission electron microscopy (HR-TEM), and correlative microscopy, have enabled the evaluation of antibacterial treatments, due to the potential to reveal the efficacy of different molecules in breaking down the biofilm. In conclusion, evidence based on scientific literature shows that established microscopic methods represent the most common tools used to characterize biofilm and its morphology in oral microbiology. Further protocols and studies on the application of advanced microscopic techniques are needed to obtain precise details on the microbiological and pathological aspects of oral biofilm
The role of innovation technology in teaching and learning strategies in anatomy curricula in dental hygiene school
Full text linkPurpose. This research aims to assess the diversification of pedagogical and learning methodologies, leveraging advanced technological tools within a dental hygiene educational framework. Methods. Students enrolled in the dental hygiene program were considered as population sample, divided in two groups: The test group (N=16) subjected to the investigation of the virtual dissection table (VDT) and the control group (n=17) who attended lectures using traditional teaching method. The control group’s performance was assessed through a 40-item multiple-choice questionnaire and an open-ended question; the test group was evaluated via a final test consisting of a presentation on an anatomical topic and a 40-item multiple-choice questionnaire. The final grade derived from the mean score of the final tests, and it was assigned on a scale of 30/30. Additionally, the test group’s perceptions toward the use of the VDT were gauged through an evaluative questionnaire comprising 7 questions. Results. The study found a statistically significant difference in failure rates between the control group and the test group. However, the average exam scores did not show a statistically significant difference between the two groups, despite the test group showing some improvement. The evaluation survey results indicated high levels of satisfaction with the use of the VDT, with the quality of the virtual images, anatomical resources, and the user-friendly interface. Additionally, students strongly supported integrating traditional lectures with VDT laboratory sessions, with no negative feedback reported. Conclusions. The VDT represents an innovative anatomy teaching tool, warmly welcomed by healthcare profession students, whose performances were positively affected
Use of two virtual dissection tables in a postgraduate oral anatomy course: feedback from the students
Full text linkBACKGROUND: Advancements in medical education technologies transformed the teaching and learning of several disciplines, including human anatomy, which is considered the core of health sciences education. Recent technological innovations, including virtual dissection tables like the Anatomage® and SECTRA® table, provided interactive 3D models and clinical imaging that address these limitations. This study aims to evaluate the rating of two different VDTs in teaching clinical anatomy to post-graduate dental doctors, emphasizing their perceived advantages for clinical practice. METHODS: A population (N = 24) of post-graduate students in oral surgery (N = 7) and orthodontics (N = 17) were enrolled in this study. The design of the lecture included practical sessions on the Anatomage® and SECTRA® table, including cases evaluations on anatomy structures. Anonymous surveys were used to evaluate the grade of perception on the use of both VDTs. The software used for statistical calculations was GraphPad Prism version 10.4.0 (621) for Windows. RESULTS: The post-graduate students significantly positively considered the use of VDTs as very useful and user-friendly learning instruments, offering very satisfying quality of the digital images. The level of clinical self-confidence and satisfaction of the proposed teaching method lecture was considered statistically positive. CONCLUSIONS: The integration and the diversification of the anatomy teaching strategies, using innovation technologies, increase the learning processes and improve the clinical self-confidence in post-graduate dental students
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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