750 research outputs found

    The reliability of the anterior pelvic plane for computer navigated acetabular component placement during total hip arthroplasty: Prospective study with the EOS imaging system

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    Introduction Computer navigated total hip arthroplasty is mostly based on the use of the anterior pelvic plane (APP) as a reference. EOS is a new imaging system that provides three-dimensional analysis of the pelvis in a functional position with a low dose of radiation. The aim of this study was to evaluate the reliability of the APP for placement of the cup during computer navigated THA using EOS. Hypothesis The reliability of the APP is limited for the placement of the acetabular cup during computer navigated THA. Materials and methods This was a prospective monocentric study using the EOS imaging system evaluating 44 patients in the standing position three months after computer navigated THA (Orthopilotℱ). Reproducibility of EOS measurements were analyzed using SterEOS software and the reliability of the navigation data for the position of the cup were assessed. Results Intra and interobserver reproducibility of the measurements of the orientation of the cup by EOS were good with correlation coefficients above 93% and 95% and confidence intervals of less than ± 5°. Mean cup inclination and anteversion were 41.3° and 20.9° and 44.3° and 29.5° respectively in operatively and post-operatively. The differences between measurements of operative cup inclination using computer assisted navigation and the post-operative EOS measurements were significant (P < 0.05) with a correlation coefficient of less than 40%. Discussion Our study confirms the lack of precision of the APP as a reference for positioning of the acetabular component, especially in relation to anteversion. Although for many years the APP was considered to be a global reference, in fact, it is subject to significant inter-individual variations and variations during changes in position. These factors, associated with the difficulty of determining the preoperative APP, explain the lack of reliability of this reference. Preoperative evaluation of the orientation of APP by EOS and its integration into the navigation system could help the operator position these components

    Indicators of nitrogen status for ornamental woody plants

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    Indicators of plant nitrogen (N) status adapted to woody ornamental plants are essential to adjust fertilization to plant N demand in ornamental plant nurseries. N supply influences the synthesis of both proteins and polyphenols, because their biosynthetic pathways share a common precursor

    Assessing the visual aspect of rotating virtual rose bushes by a labeled sorting task

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    Aesthetics is one of the major parameters for consumers when buying a rose bush. Therefore, managing this quality is important for agronomists. Tools are needed to assess visual characteristics and to find links with architectural plant parameters. Sensory analyses were developed using real plants and photographs as stimuli. With technology and modeling improvements, using virtual plants could presents numerous advantages. This study demonstrated the feasibility of using rotating virtual rose bush videos as stimuli for a labeled sorting task. The virtual rose bush reflected a natural within-crop variability of one cultivar based on bud breaks location and axes length. Two panels of subjects closely linked to the horticulture sector sorted and described 40 rotating virtual rose bush videos. Non-metric Multidimensional Scaling (MDS) results for both panels were similar and allowed us to highlight five groups of virtual rose bushes with their specific sensory characteristics and their own most representative products using a combination of the paragons and the most typical products. This approach revealed that subjects detected high visual differences between products, and that by using rotation, they were able to integrate 3D properties about variations around plant facets. Finally, a labeled sorting task is a powerful method for preliminary exploration of the visual aspect of virtual plants

    Comparison of modified Hackethal bundle nailing versus anterograde nailing for fixation of surgical neck fractures of the humerus: Retrospective study of 105 cases

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    AbstractIntroductionIntramedullary fixation of displaced surgical neck fractures of the humerus can be performed either by retrograde pinning or anterograde nailing. The goal of the current study was to compare the postoperative reduction and stability obtained with these two techniques.HypothesisIntramedullary nailing will provide the best reduction and stabilization of these fractures.Patients and methodsThis was a multicenter retrospective study that included patients with sub-tuberosity fractures with or without greater tuberosity fragment. These patients were treated either by retrograde Hackethal type pinning (group 1) or Telegraph anterograde nailing (group 2). To be included, patients needed to have A/P and lateral X-rays that had been taken before the surgery, immediately post-operative, between four and six weeks post-operative, and at the last follow-up. The outcomes were head angulation, translation and greater tuberosity position.ResultsOne hundred and five patients (40 retrograde pinning and 65 anterograde nailing) with an average age of 69 years (18–97 years) were included. The pre-operative fracture displacement was similar between the two groups. After the surgery, the A/P head angulation had been corrected in 72.5% of patients in group 1 and 84% in group 2 (no significant difference). Translation was still present in 17.5% of patients in group 1 and 1.5% in group 2 (P<0.05). At the last follow-up, union was achieved without residual angulation on lateral X-rays in 71% of patients in group 1 and 88% in group 2 (P<0.05). The fractures had healed with residual translation is 19.5% of patients in group 1 and 3% in group 2 (P<0.05).Discussion and conclusionIn cases of displaced surgical neck fractures with or without a greater tuberosity fragment, anterograde nailing provides better reduction and stability than retrograde pinning. However, fixation of the greater tuberosity fragment must be improved.Level of evidenceIV (retrospective comparative study)

    What are the contributions of cytokinins, abscisic acid and sugars in bud outgrowth regulation by light intensity in rose?

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    In ornamentals, particularly in rose bush, the visual quality of a plant is an important element of its quality. Bud outgrowth, which is at the origin of branching, strongly impacts plant shape and compactness, that are two traits involved in rosebush visual quality (Boumaza et al. 2009).Changes in the environmental conditions, in particular in light intensity, can impact the number of buds that grow out and change bud outgrowth gradient along a stem in various species, including rose (Leduc et al. 2014; Furet et al. 2014). Bud outgrowth is controlled by a network of interacting hormones, the principal ones are auxin, cytokinins and strigolactones, but the role of abscisic acid is also emerging. Sugars are involved in bud outgrowth regulation too and they interact with the hormonal network. A natural hypothesis is that decreasing light intensity may limit bud outgrowth via a shortage in sugars and changes in plant hormonal content. However, the mechanisms by which light intensity affects bud outgrowth, especiallythe respective role of the different hormones and sugars in this regulation, is still poorly understood.The objective of this work was to test if the control of bud outgrowth gradient along the stem by light intensity is mediated by sugars, cytokinins and/or abscisic acid and to assess which of these actors is the main limiting actor. The study was conducted on whole plants and attention was paid to the location of bud outgrowth along the shoot

    \'Evaluation entre pairs en math\'ematiques: activit\'e d'\'etudiant∙\bulletes lors d'\'evaluations de preuves

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    This article deals with peer-assessment in the context of higher education teaching in mathematics, and examines the nature of student activity when assessing work produced by peers. After an overview of research on peer assessment, we propose an experiment with students in a specific post-secondary scientific class, and analyze the activity of the students involved. Our analyses are based on a priori analyses of the proposed tasks and tools from research on students personal mathematical work. We base on written notes of assessments, observations of pairs in assessment situations, and answers to a questionnaire on the perception of their activity. We have identified some specific student activities during the peer assessment process, in particular related to the analysis and correction of proofs, but also to the awareness of the issues associated with evaluation. This enables us to argue for the potential of peer assessment in higher mathematics education.Comment: in French languag

    Light and nitrogen nutrition regulate apical control in Rosa hybrida L.

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    Apical control is defined as the inhibition of basal axillary bud outgrowth by an upper actively growing axillary axis, whose regulation is poorly understood yet differs markedly from the better-known apical dominance. We studied the regulation of apical control by environmental factors in decapitated Rosa hybrida in order to remove the apical hormonal influence and nutrient sink. In this plant model, all the buds along the main axis have a similar morphology and are able to burst in vitro. We concentrated on the involvement of light intensity and nitrate nutrition on bud break and axillary bud elongation in the primary axis pruned above the fifth leaf of each rose bush. We observed that apical control took place in low light (92 ÎŒmol m−2 s−1), where only the 2-apical buds grew out, both in low (0.25 mM) and high (12.25 mM) nitrate. In contrast, in high light (453 ÎŒmol m−2 s−1), the apical control only operates in low nitrate while all the buds along the stem grew out when the plant was supplied with a high level of nitrate. We found a decreasing photosynthetic activity from the top to the base of the plant concomitant with a light gradient along the stem. The quantity of sucrose, fructose, glucose and starch are higher in high light conditions in leaves and stem. The expression of the sucrose transporter RhSUC2 was higher in internodes and buds in this lighting condition, suggesting an increased capacity for sucrose transport. We propose that light intensity and nitrogen availability both contribute to the establishment of apical control

    Depressive mixed state: Evidence for a new form of depressive state in type I and II bipolar patients

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    Katia M&amp;rsquo;Bailara1, Donatienne Van den Bulke2, Nicolas Demazeau2, Jacques Demotes-Mainard3, Chantal Henry11EA4139 Laboratoire de psychologie, Universit&amp;eacute; Victor Segalen, Bordeaux Cedex, France; 2Centre Hospitalier Charles Perrens, Bordeaux Cedex, France; 3INSERM-DRCT, ECRIN, Paris, FranceBackground: A high proportion of unipolar and bipolar type II patients can present a depressive mixed state (DMX). This state is defined by an association of a major depressive episode with at least two specific hypomanic symptoms. This state seems underdiagnosed and this could have treatment implications. The aims of our study were: (i) to investigate the frequency of DMX in type I and II bipolar patients hospitalized for a severe or resistant depressive episode and (ii) to assess the therapeutic response in naturalistic conditions.Methods: Forty-two consecutive bipolar patients referred by psychiatrists for a severe or resistant depressive episode were assessed using the French version of the Mini International Neuropsychiatric Interview 5.0 (MINI 5.0), which assesses the suicide risk and provides DSM-IV diagnosis. The intensity of mood episodes was evaluated using the MADRS and Bech-Rafaelsen Mania Scale. One group of patients included patients presenting only depressive symptoms (ie, pure major depressive episode (MDE)), and the second group included patients with a major depressive episode and at least two specific hypomanic symptoms (DMX).Results: Twenty-one patients (50%) had a pure MDE and 21 patients (50%) had a DMX. The treatment leading to recovery was very different in the two groups. Antidepressants were effective (77%) in MDE patients, whereas antipsychotics were effective (81%) in DMX. 38% of patients with a MDE also received a mood stabilizer versus 86% in the group of DMX. Five MDE patients (24%) and one DMX patient required electroconvulsive therapy. The suicidal ideations did not differ between the two groups (p = 0.7).Conclusions: Some mood episodes in bipolar patients (type I and II) are characterised by depressive and hypomanic symptoms but do not meet criteria for mixed episode as defined by DSM-IV. These episodes are often diagnosed as depressive states, but are worsened by antidepressants and often considered as resistant depression. They rapidly respond to antimanic treatment. New categories of mood disorders should take into account this particular mixed state.Keywords: bipolar depression, mixed state, depressive mixed state, resistant depressio
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