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Copyright of Pratiques Psychologiques is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pratiques Psychologiques is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Psychologie Française is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Although the same simple laws govern cancer outcome (cell division repeated again and again), each tumour has a different outcome before as well as after irradiation therapy. The linear-quadratic radiosensitivity model allows an assessment of tumor sensitivity to radiotherapy. This model presents some limitations in clinical practice because it does not take into account the interactions between tumour cells and non-tumoral bystander cells (such as endothelial cells, fibroblasts, immune cells…) that modulate radiosensitivity and tumor growth dynamics. These interactions can lead to non-linear and complex tumor growth which appears to be random but that is not since there is not so many tumors spontaneously regressing. In this paper we propose to develop a deterministic approach for tumour growth dynamics using chaos theory. Various characteristics of cancer dynamics and tumor radiosensitivity can be explained using mathematical models of competing cell species. [Copyright &y& Elsevier]

Abstract: Traumatic Brain Injury (TBI) and later serious psychopathology have long been associated in the literature. Psychotic disorder following traumatic head injury is reported to occur in 0.7 to 9% of patients who sustain a head injury. This paper summarizes the recent literature about psychotic symptoms following TBI and try to articulate these psychotic disorders to a pathophysiological model of primary schizophrenia. Psychotic disorder due to a general medical condition (TBI) indicates that the hallucinations or delusions are the direct physical consequences of the medical condition. A contrario, schizophrenia-like psychosis is a secondary schizophreniform syndrom that must be differentiated from posttraumatic schizophrenia where the head trauma is an external factor furthering the onset of a primary psychosis. A dimensional approach could although take place for understanding pathophysiology. Head injury has been reported to increase the likelihood of the development of psychosis disorder due to TBI, schizophrenia-like psychosis and posttraumatic schizophrenia. While TBI is a major public health issue, schizophrenia following TBI is relatively rare and poorly studied. The onset of schizophrenia occurs most commonly from late adolescence to mid-adulthood, in an age group where head injury is more frequent. Even if early illness features of schizophrenia might increase exposure to TBI, posttraumatic schizophrenia could be the result of a gene-environment interaction. The pathophysiology research in psychotic disorders following TBI does not distinguish schizophrenia from other psychotic syndromes but have to consider a dimensional approach of these psychotic phenomena. Family history of schizophrenia and frontal or parietal lobe deficits was more common in patients with posttraumatic psychotic symptoms. Susceptibility to schizophrenia is believed to be due to multiple genetic and interacting factors and mild childhood head injury may play a role in the development and onset of schizophrenia in families with a strong genetic predisposition. The authors suggest hypotheses aimed at furthering the understanding of the physiologic mechanisms relating traumatic brain injuries to psychotic symptoms. Psychotic disorder following TBI, schizophrenia-like psychosis and posttraumatic schizophrenia are a potential interest to clinicians and neuroscientists, as it may provide clues to understanding primary psychotic disorders such as schizophrenia. Schizophrenia is a psychotic disorder commonly attributed to the interaction of genetic vulnerability and environmental events which implies that environmental factors modulate the effects of the genotype. Schizophrenia related to TBI could also be the result of a gene-environment interaction. Schizophrenia genes may increase exposure to head trauma (through agitation or cognitive impairment), with head trauma further increasing the risk for schizophrenia. Further studies are needed to articulate the links between secondary psychotic symptoms and primary schizophrenia in a structure/function paradigm. The new imaging techniques of magnetic resonance imaging, position emission tomography and single-photon emission computed tomography could aid in this sense. [Copyright &y& Elsevier]

Abstract: Some recent controversies have highlighted that a genetic or a neuropsychological determinism was the view that dominated the debate in the field of the etiopathological understanding of externalised disorders in the scientific community. Based on a review of the recent literature, I will show that other views are trying to integrate the diversity and the complexity of the factors that influence these behavioural manifestations. The model that better encompasses this complexity is a developmental model of probabilistic epigenetic. In this paper, I summarize several lines of studies that support this model. To this purpose, I will leave the categorical approach of the psychiatric nosography, to adopt a dimensional approach of the phenomenology that will help to follow and focus on specific pertinent dimensions such as clinical signs, temperamental and psychological characteristics, environmental and/or genetic factors in order to study their interactions and their possible developmental product. This model also permits a specific temporal focus on early interactions that many consider as crucial in terms of developmental cues. [Copyright &y& Elsevier]

Abstract: Living tissues are mainly constituted of soft matter. This so particular state, neither liquid, neither gas, nor solid led to the use, in simulation, of increasingly complicated mathematical models. These tissues are organised in multi-layers, present anisotropic properties and nonlinear behaviour. The evaluation of the interface pressure by traditional rigid sensors leads to errors of measurement. The device FORSAFE performs the measurement of the pressure on the fetal head. It is aimed to limit the risks due to a bad positioning and a too important tightening of the forceps on the head of the new-born, during the childbirth. It is based on an original method bio-inspired reproducing the sense of touch, by micro-palpations. Complications in forceps deliveries are rare but their consequences might be dramatics. This situation could be avoided if the obstetrician knows the information concerning symmetry of the obstetrical forceps position on the fetal head and the related interface pressure. Indeed, forceps delivery is an emergency gesture which is normally not expected. The aims of the FORSAFE device are: first, to prevent instrumented delivery accidents, secondly, to provide a safe training of forceps technique. This paper presents the original method of the interface pressure measurement, the results obtained on a physical model of interface pressure as well as the corrections performed on the probe placed on the forceps. [Copyright &y& Elsevier]

Carcinogenesis is generally viewed as the result of a disrupted equilibrium between the processes of proliferation, differenciation, migration and loss. In cell kinetics, perturbation of fundamental kinetic parameters such as the mitotic index or the growth fraction may reflect a carcinogenic process. In this paper, we present a system of deterministic differential equations describing the dynamical evolution of a cell population. We show that this model can account for asynchronicity of cells and simulate the fraction of labelled mitoses experiment as well. [Copyright &y& Elsevier]