A road map to manual segmentation of cerebral structures.

Manual segmentation is an essential tool in the researcher's technical arsenal. It is a frequent practice necessary for image analysis in many protocols, especially in neuroimaging and comparative brain anatomy. In the framework of emergence of studies focusing on alternative animal models, manual segmentation procedures play a critical role.

Sex-related variability of white matter tracts in the whole HCP cohort.

Behavioral differences between men and women have been studied extensively, as have differences in brain anatomy. However, most studies have focused on differences in gray matter, while white matter has been much less studied. We conducted a comprehensive study of 77 deep white matter tracts to analyze their volumetric and microstructural variability between men and women in the full Human Connectome Project (HCP) cohort of 1065 healthy individuals aged 22-35 years.

PhyberSIM: a tool for the generation of ground truth to evaluate brain fiber clustering algorithms.

Diffusion Magnetic Resonance Imaging tractography is a non-invasive technique that produces a collection of streamlines representing the main white matter bundle trajectories. Methods, such as fiber clustering algorithms, are important in computational neuroscience and have been the basis of several white matter analysis methods and studies. Nevertheless, these clustering methods face the challenge of the absence of ground truth of white matter fibers, making their evaluation difficult.

Phybers: a package for brain tractography analysis.

We present a Python library (Phybers) for analyzing brain tractography data. Tractography datasets contain streamlines (also called fibers) composed of 3D points representing the main white matter pathways. Several algorithms have been proposed to analyze this data, including clustering, segmentation, and visualization methods.

Virtual Exercise in Medicine: A Proof of Concept in a Healthy Population.

Background: Science is beginning to establish the benefits of the use of virtual reality (VR) in health care. This therapeutic approach may be an appropriate complementary treatment for some mental illnesses. It could prevent high levels of morbidity and improve the physical health of patients.

ProbaStem, a pipeline towards the first high-resolution probabilistic atlas of the whole human brainstem.

The brainstem plays an essential role in many vital functions, such as autonomic control, consciousness and sleep, motricity, somatic afferent function, and cognition. Its involvement in several neurological diseases and the definition of brainstem targets for deep brain stimulation (DBS) explain the need for brainstem atlases describing its structural organization and connectivity from several modalities, from histology to ultrahigh field ex vivo MRI. Nonetheless, these atlases are often limited to a subpart of the brainstem or only include a single subject, the brainstem variability being considered low.

In vivo mapping of the deep and superficial white matter connectivity in the chimpanzee brain.

Mapping the chimpanzee brain connectome and comparing it to that of humans is key to our understanding of similarities and differences in primate evolution that occurred after the split from their common ancestor around 6 million years ago. In contrast to studies on macaque species' brains, fewer studies have specifically addressed the structural connectivity of the chimpanzee brain and its comparison with the human brain. Most comparative studies in the literature focus on the anatomy of the cortex and deep nuclei to evaluate how their morphology and asymmetry differ from that of the human brain, and some studies have emerged concerning the study of brain connectivity among humans, monkeys, and apes.

Cross-subject variability of the optic radiation anatomy in a cohort of 1065 healthy subjects.

Introduction: Optic radiations are tracts of particular interest for neurosurgery, especially for temporal lobe resection, because their lesion is responsible for visual field defects. However, histological and MRI studies found a high inter-subject variability of the optic radiation anatomy, especially for their most rostral extent inside the Meyer's temporal loop. We aimed to better assess inter-subject anatomical variability of the optic radiations, in order to help to reduce the risk of postoperative visual field deficiencies.

[Performance of an Ultrasound Based Endometriosis Staging System (UBESS) for predicting rectal involvement and type of surgical procedure in patients with digestive endometriosis].

Objective: Preoperative assessment of rectal damage in digestive endometriosis requires rectal endoscopic ultra-sonography an invasive exam that is not well received by the patients. A standardized approach using an Ultrasound-Based Endometriosis Staging System (UBESS)could be an interesting tool in this indication. This article aims to evaluate the performance of UBESS in the prediction of rectal involvement and the type of surgical procedure.

[Evolution of attractiveness of Medical Biology to medical students in 2022].

Since 2010, the postgraduate training diploma in laboratory medicine has experienced a strong decline in its attractiveness to French medical students. This work aims to objectify and quantify this decline between 2004 and 2021. To do so, we have carried out an analyze of the trend to choose laboratory medicine after the national ranking review performed by all French students.

Difference in Pap test uptake between women who have sex with women and other women in France: A comparative survey of 2032 women.

The elimination of cervical cancer has been a priority of the World Health Organization since 2018. The number of these cancers induced by the human papillomavirus (HPV) could be drastically reduced through vaccination and regularly screening by Pap tests. Guidelines for cervical cancer screening apply to all women, including those who have sexual relations with women (WSW), as HPV can be transmitted during sex between two women.

Superficial white matter bundle atlas based on hierarchical fiber clustering over probabilistic tractography data.

The study of short association fibers is still an incomplete task due to their higher inter-subject variability and the smaller size of this kind of fibers in comparison to known long association bundles. However, their description is essential to understand human brain dysfunction and better characterize the human brain connectome. In this work, we present a multi-subject atlas of short association fibers, which was computed using a superficial white matter bundle identification method based on fiber clustering.

Disentangling the variability of the superficial white matter organization using regional-tractogram-based population stratification.

Each variation of the cortical folding pattern implies a particular rearrangement of the geometry of the fibers of the underlying white matter. While this rearrangement only impacts the ends of the long pathways, it may affect most of the trajectory of the short bundles. Therefore, mapping the short fibers of the human brain using diffusion-based tractography requires a dedicated strategy to overcome the variability of the folding patterns.

A novel male Japanese quail structural connectivity atlas using ultra-high field diffusion MRI at 11.7 T.

The structural connectivity of animal brains can be revealed using post-mortem diffusion-weighted magnetic resonance imaging (MRI). Despite the existence of several structural atlases of avian brains, few of them address the bird's structural connectivity. In this study, a novel atlas of the structural connectivity is proposed for the male Japanese quail (Coturnix japonica), aiming at investigating two lines divergent on their emotionality trait: the short tonic immobility (STI) and the long tonic immobility (LTI) lines.

Nomogram for Predicting a Complex Ureteral Procedure in Pelvic Endometriosis Surgery.

Study Objective: To develop a nomogram for predicting the type of ureteral procedure in pelvic deep endometriosis (DE) surgery (1) and to describe the factors and complications associated with the ureteral procedure (2).

Design: Retrospective monocentric study of 920 patients who underwent surgery for pelvic DE between June 2009 and March 2020 in the gynecologic surgery department of the Versailles Hospital Center. The main criterion was evaluation of the ureteral procedure, classified as simple (isolation of the ureter) or complex (dissection of the ureter, segmental ureteral resection, or nephroureterectomy).

[POCT-management during the first wave of Covid-19 in France. Results of a national survey leaded by the SFBC-POCT Working Group].

During the first wave of Covid-19 in France, in spring 2020, healthcare institution's laboratory had to adapt itself quickly to the growing demand for emergency biology, in particular by reorganizing their POCT analyzers: redeployment of analyzers and/or new installations. In order to analyze this management, a subgroup of 15 hospital biologists from the SFBC Working Group "Biochemical markers of Covid-19" sent, in fall 2020, an on-line survey to French hospital laboratories using POCT. Answers analysis (n = 86) shows a territorial disparity related to the severity of the first wave: increased activity essentially in red zones, management of unexpected situations, training of additional nursing staff for 40 % of the laboratories.

Enhanced Automatic Segmentation for Superficial White Matter Fiber Bundles for Probabilistic Tractography Datasets.

This paper presents an enhanced algorithm for automatic segmentation of superficial white matter (SWM) bundles from probabilistic dMRI tractography datasets, based on a multi-subject bundle atlas. Previous segmentation methods use the maximum Euclidean distance between corresponding points of the subject fibers and the atlas centroids. However, this scheme might include noisy fibers.

Group-Wise Cortical Surface Parcellation Based on Inter-Subject Fiber Clustering.

We present an automatic algorithm for the group-wise parcellation of the cortical surface. The method is based on the structural connectivity obtained from representative brain fiber clusters, calculated via an inter-subject clustering scheme. Preliminary regions were defined from cluster-cortical mesh intersection points.

Physical and digital phantoms for validating tractography and assessing artifacts.

Fiber tractography is widely used to non-invasively map white-matter bundles in vivo using diffusion-weighted magnetic resonance imaging (dMRI). As it is the case for all scientific methods, proper validation is a key prerequisite for the successful application of fiber tractography, be it in the area of basic neuroscience or in a clinical setting. It is well-known that the indirect estimation of the fiber tracts from the local diffusion signal is highly ambiguous and extremely challenging.

Integration of spatio-temporal variations of surface metabolomes and epibacterial communities highlights the importance of copper stress as a major factor shaping host-microbiota interactions within a Mediterranean seaweed holobiont.

Background: Although considered as holobionts, macroalgae and their surface microbiota share intimate interactions that are still poorly understood. Little is known on the effect of environmental parameters on the close relationships between the host and its surface-associated microbiota, and even more in a context of coastal pollutions. Therefore, the main objective of this study was to decipher the impact of local environmental parameters, especially trace metal concentrations, on an algal holobiont dynamics using the Phaeophyta Taonia atomaria as a model.

Aberrant Subnetwork and Hub Dysconnectivity in Adult Bipolar Disorder: A Multicenter Graph Theory Analysis.

Neuroimaging evidence implicates structural network-level abnormalities in bipolar disorder (BD); however, there remain conflicting results in the current literature hampered by sample size limitations and clinical heterogeneity. Here, we set out to perform a multisite graph theory analysis to assess the extent of neuroanatomical dysconnectivity in a large representative study of individuals with BD. This cross-sectional multicenter international study assessed structural and diffusion-weighted magnetic resonance imaging data obtained from 109 subjects with BD type 1 and 103 psychiatrically healthy volunteers.

Fiber Clustering Acceleration With a Modified Kmeans++ Algorithm Using Data Parallelism.

Fiber clustering methods are typically used in brain research to study the organization of white matter bundles from large diffusion MRI tractography datasets. These methods enable exploratory bundle inspection using visualization and other methods that require identifying brain white matter structures in individuals or a population. Some applications, such as real-time visualization and inter-subject clustering, need fast and high-quality intra-subject clustering algorithms.

Synergistic effects of temperature and light affect the relationship between Taonia atomaria and its epibacterial community: a controlled conditions study.

In the context of global warming, this study aimed to assess the effect of temperature and irradiance on the macroalgal Taonia atomaria holobiont dynamics. We developed an experimental set-up using aquaria supplied by natural seawater with three temperatures combined with three irradiances. The holobiont response was monitored over 14 days using a multi-omics approach coupling algal surface metabolomics and metabarcoding.