Vascularity and perfusion of human gliomas xenografted in the athymic nude mouse.

The vascularisation and perfusion of seven subcutaneously xenografted human glioma lines established from surgical specimens has been analysed using an anti-collagen type IV antibody to visualise the vascular walls in combination with a perfusion marker (Hoechst 33342). A computer-based digital image processing system was employed for quantitative analysis of the parameters. The vascular architecture of individual tumours belonging to the same tumour line showed a consistent similarity, while substantial differences occurred between the various tumour lines derived from different patients. Despite the presence of a large inter-tumour variation in vascular area as a proportion of the tumour area, this vascular parameter clearly showed tumour line-specific characteristics. The perfused fraction of the tumour vessels also showed a large inter-tumour variation for all tumour lines ranging from 20% to 85%, but the majority of tumours of all lines had perfusion fractions of more than 55%. Despite large variation, the perfused vascular area as a proportion of the tumour cross-sectional area exhibited clear tumour line-specific tendencies. These observations suggest that consistent differences in vascular parameters are present between glioma xenograft lines, although the tumour lines all originated from histologically similar human high-grade gliomas. These differences may have important consequences for treatment and clinical behaviour of this type of tumour

Representing narrative and testimonial knowledge in sense-making software for crime analysis.

Abstract. In the AVERs sense-making tool for crime analysis different types of information are represented in different ways. More precisely, narrative knowledge is represented in an explanatory direction and testimonial knowledge in an indicative direction. This paper shows that this distinction agrees with the preference of potential users and reduces the number of interpretation errors made by them

Expected survival with and without second-line palliative chemotherapy: who wants to know?

Background According to surveys, many patients with advancedcancer wish to receive survival information.Objective This study invest igated information preferences by offer-ing patients a decision aid (DA) with infor mation on expected sur-vival for two treatment options: supportive care with or withoutsecond-line palliative chemotherapy. Predicto rs of accepting sur-vival information were explored.Design Eligible patients in this multicentre prospective study wereoffered secon d-line chemotherapy for advanced breast or colorectalcancer. A nurse presented a DA on second-line treatment andasked patients whether they desired information on (i) adverseevents, (ii) tumour response and (iii) survival. Data on 50 clinicaland psychosocial patient characteristics were collected from inclu-sion forms and patient questionnaires.Results Seventy-seven patients received a DA; median age62 years (range 32–80), 61% female, 77% colorectal cancer. Fifty-seven patients (74%; 95% CI 64–84) desired survival information.Four psychosocial characteristics (e.g . deliberative decision style)independently predicted information desire. However, the use ofthese characteristics to predict information desire hardly outper-formed a simple prediction rule.Conclusions Many patients desired information on expected sur-vival when deciding about second-line treatment. However, ourexploratory analysis indicated that patients desiring this informa-tion could not be identified based on their clinical or psychosocialcharacteristics. These findings can help encourage candid discus-sions about expected survival. Health professionals should be care-ful not to make implicit assumptions of information desire based on patient characteristics, but to explicitly ask patients if survivalinformation is desired, and act accordingly

Финансовое обеспечение деятельности туристического предприятия

Целью статьи является разработка рекомендаций по повышению эффективности финансового обеспечения деятельности туристического предприятия, определение приоритетных путей совершенствования финансовых показателей его деятельности

Games, Simulations, Immersive Environments, and Emerging Technologies

International audienceThis entry presents an overview of advanced technologies to support teaching and learning. The use of innovative interactive systems for education has never been higher. Far from being just a trend, the objective is to use the current technology to cover educational needs and create relevant pedagogical situations. The arguments in their favor are generally their positive effects on learners’ motivation and the necessity to provide learning methods adapted to our growing digital culture. The new learning technologies and emerging trends are first reviewed hereunder. We thus define and discuss learning games, gamification, simulation, immersive environments and other emerging technologies. Then, the current limits and remaining scientific challenges are highlighted

Influence of head models on neuromagnetic fields and inverse source localizations

BACKGROUND: The magnetoencephalograms (MEGs) are mainly due to the source currents. However, there is a significant contribution to MEGs from the volume currents. The structure of the anatomical surfaces, e.g., gray and white matter, could severely influence the flow of volume currents in a head model. This, in turn, will also influence the MEGs and the inverse source localizations. This was examined in detail with three different human head models. METHODS: Three finite element head models constructed from segmented MR images of an adult male subject were used for this study. These models were: (1) Model 1: full model with eleven tissues that included detailed structure of the scalp, hard and soft skull bone, CSF, gray and white matter and other prominent tissues, (2) the Model 2 was derived from the Model 1 in which the conductivity of gray matter was set equal to the white matter, i.e., a ten tissuetype model, (3) the Model 3 consisted of scalp, hard skull bone, CSF, gray and white matter, i.e., a five tissue-type model. The lead fields and MEGs due to dipolar sources in the motor cortex were computed for all three models. The dipolar sources were oriented normal to the cortical surface and had a dipole moment of 100 μA meter. The inverse source localizations were performed with an exhaustive search pattern in the motor cortex area. A set of 100 trial inverse runs was made covering the 3 cm cube motor cortex area in a random fashion. The Model 1 was used as a reference model. RESULTS: The reference model (Model 1), as expected, performed best in localizing the sources in the motor cortex area. The Model 3 performed the worst. The mean source localization errors (MLEs) of the Model 3 were larger than the Model 1 or 2. The contour plots of the magnetic fields on top of the head were also different for all three models. The magnetic fields due to source currents were larger in magnitude as compared to the magnetic fields of volume currents. DISCUSSION: These results indicate that the complexity of head models strongly influences the MEGs and the inverse source localizations. A more complex head model performs better in inverse source localizations as compared to a model with lesser tissue surfaces