[Communication and expression. Various forms of verbal expression. 9. Semi-directive conferences].
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Communication↗
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Results for “semi-directed”
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Methodology of "in vivo" anatomical study and stereo-electroencephalographic exploration in brain surgery for epilepsy.
Stereotactic implantation of deep SEEG electrodes performed as a prelude to surgery in some patients with drug-resistant focal epilepsy requires previous "in vivo" identification and localization of the cortical and subcortical structures to be explored, visualized "semi-directly" "or directly" by neuroradiological imaging techniques. Stereoscopic stereotactic teleangiography is a safety factor in transcutaneous electrode implantation and biopsies, but it also localizes the cortical sulci in a "semi-direct" manner by identifying vascular segments deeply buried in this sulci, which constitute their lamina vascularis. Although RMI greatly contributes to the study of the pallium, visualizing fragments of sulci and gyri does not necessarily mean that these structures can be identified with certainty, notably on the convexity of the brain. To solve this problem, RMI sections are enlarged by a photographic process, then combined with the images obtained from neuroradiological stereotaxis by means of anatomical landmarks that are common to both types of documents, using the bicommissural reference systems, bicallosal l/nl or vascular segments. This enables the angiographic laminae vascularis, which define the sulci in a "semi-direct" manner, to be used a kind of "Ariadne's clew" to identify cortical structures on RMI sections. In percutaneous stereotactic electrode implantation, the choice of the trajectories results from a compromise between the need to reach the desired anatomical structures, identified and localized within the stereotactic space, and the necessity to avoid the blood vessels displayed by stereoangiography. In some cases, the accuracy of anatomical definition can be verified during the SEEG study and/or by the evoked potential technique. Once the electrodes have been removed, their traces can be identified in a control RMI examination which constitutes a further verification.
Brain↗
PaNDA: Efficient Optimization of Phylogenetic Diversity in Networks.
Phylogenetic diversity (PD) plays an important role in biodiversity, conservation, and evolutionary studies by measuring the diversity of a set of taxa based on their phylogenetic relationships. In phylogenetic trees, a subset of k taxa with maximum PD can be found by a simple and efficient greedy algorithm. However, this algorithmic tractability is lost when considering phylogenetic networks, which incorporate reticulate evolutionary events such as hybridization and horizontal gene transfer. To address this challenge, we introduce PaNDA (Phylogenetic Network Diversity Algorithms), the first software package and interactive graphical user-interface for exploring, visualizing, and maximizing diversity in phylogenetic networks. PaNDA includes a novel algorithm to find a subset of k taxa with maximum diversity, running in polynomial time for networks of bounded scanwidth, a measure of tree-likeness of a network that grows slower than the well-known level measure. This algorithm considers the variant of PD on networks in which the branch lengths of all paths from the root to the selected taxa contribute towards their diversity. We demonstrate the scalability of this algorithm on simulated networks, successfully analyzing level-15 networks with up to 200 taxa in seconds. We also provide a proof-of-concept analysis using a phylogenetic network on Xiphophorus species, illustrating how the tool can support diversity studies based on real genomic data. The software is easily installable and freely available at https://github.com/nholtgrefe/panda. Additionally, we extend the definition of PD to semi-directed phylogenetic networks, which are mixed graphs increasingly used in phylogenetic analysis to model uncertainty of the root location. We prove that finding a subset of k taxa with maximum diversity remains NP-hard on semi-directed networks, but do present a polynomial-time algorithm for networks with bounded level.
network↗
Proliferation kinetics in native chorionic villus cells.
In accordance with observations by other groups direct CVS preparations reveal only a few mitoses, whereas semi-direct cultures (overnight incubation) give good results. By monitoring the BrdU uptake with an immunological method, a delay in the proliferation activity in native villi could be observed up to 7 h after biopsy.
Bromodeoxyuridine↗
Measurement of the 2D affine Lie group parameters for visual motion analysis.
A class of linear operators is presented for estimating the local components of 2D translation, dilatation, rotation, and the shear/deformations which span the six degrees of freedom of motion of arbitrarily textured surfaces. This results in a model of visual motion analysis which proposes that the local transformations in the image are analysed by decomposing them into the six one-parameter subgroups of the 2D affine group. Each of the required invariant integral operators are easily specified by the characters of these six subgroups. The 2D affine group, however, does not have a simple structure. It is a Lie group which possesses a semi-direct product manifold, and classical harmonic analysis cannot proceed unless some mechanism is prescribed to isolate the 2D 'general linear' transformations from the 2D translations. It must also do so using measures which receive only local support from the image, since the global affine group model is only valid tangentially. A form of 'active perception' is thereby implicated; it is proposed that spatial indexing and 2D tracking is needed in order to form reliable estimates of 3D motion parameters using local operators in a data-driven fashion.
Humans↗
[Pluri-dimensional study of psychological factors in coronary disease].
To palliate certain criticisms levelled at workers studying psychological factors in coronary artery disease, the authors have applied a pluri-dimensional approach associating a semi-direct psychological interview, a self-evaluation test (Bortner scale), an Eysenck personality test and Sandler and Hazari's test of obsessional behaviour. This protocol was applied to 222 patients hospitalised for coronary artery disease and 522 random controls. The psychological interview and Bortner test showed a significantly higher proportion of A pattern and especially extreme A pattern behaviour in patients with coronary artery disease (32.6 % in coronary patients 9.7 % in controls). The personality questionnaire showed a greater tendency to neurotic behaviour in the coronary patients. These results were independant of age and sex. In the present study, psychological factors are given equal importance to other major risk factors (tobacco, hypertension, hypercholesterolaemia). They are independant of these other factors. A prospective study using the same protocol is being prepared.
Adult↗
[Recipients of oocytes donated anonymously. Psychological aspects].
This study concerns fifty patients who were investigated after a semi-directed interview. Several factors came to light: the type of couples who use assisted reproductive techniques (diagnostic and psychological profiles); the stability of the couple when failure and when success occurred; the hope of having a child and their ideas concerning the child's future; secrecy, questions that were asked concerning the practice of anonymity and non-anonymous donation of oocytes; the relationships between the recipients and the donors as well as the specific relationships that develop between the couples and their physicians. The conclusion reached from the studies show that the diagnoses of the various causes for sterility give rise to different problems. Donor anonymity makes it possible for the recipient to stamp their own pattern of identity on the child about to be born and make him part of their family history. Bringing the technique into conception of the child does not seem to interfere with the relationship between the couple and with their desire to have a child. The upbringing of the child is the responsibility of the couple.
Adult↗
[Trial of a new therapeutic agent, Pervincamine, in the post-concussion syndrome of patients with head injuries. Application of a double-blind control system and sequential analysis].
The authors have studied the influence of Pervincamine on the postconcussional syndrome in a group of 30 patients with cranial trauma examined for at least six months after their accident. The double blind testing was utilised and the patients were followed at regular intervals spanning three weeks. Each patient was evaluated by semi-directed interviews and tests of "double barrage" of Zazzo and the 15 words test of Rey. In addition, an EEG was performed at the beginning and the end of the study. Statistical analysis of the evolution of symptoms and the results obtained by psychological testing has revealed the positive action of Pervincamine on the postconcussional syndrome and on mental as well as motor functioning in general. Furthermore, the secondary effects of this product are negligible.
Adolescent↗