Diagnostic imaging strategies before and after transcatheter arterial embolization in patients with major abdominal and pelvic trauma

Selected trauma patients with severe abdomino-pelvic injuries can be treated with transcatheter arterial embolization (TAE). The present investigation has studied the usefulness of diagnostic imaging in the forefield and aftermaths of embolization. Aims: To evaluate specific radiological signs on trauma admission imaging prior to TAE that may help the interventional radiologist (IR) to rapidly assess the injured pelvic arteries. To investigate the hemodynamic changes over time after TAE of the splenic artery with means of Doppler. To evaluate the diagnostic accuracy of contrast-enhanced ultrasound after TAE of the spleen for posttraumatic lesion characterization and detection. Patients and methods: In 95 patients with pelvic trauma and suspected pelvic artery injury, fracture size and location on pelvic X-ray (PXR) and arterial blush and hematoma on computed tomography (CT) were compared with findings of arterial injury on angiography. Fisher’s exact test was used for comparison of categorical data and receiver operating characteristic curve statistic was used for comparison of continuous data with the reference method angiography. Of 22 patients with TAE of the splenic artery, intraparenchymal Doppler was performed at three different time intervals in 17 patients. Velocity parameters were sampled from three different sites and parameters for systolic inflow and intraparenchymal resistance were calculated. Seventeen healthy volunteers were used as control group. All 22 patients were also examined with contrast-enhanced ultrasound (CEUS) for detection of different posttraumatic lesions and injury severity at early (one week after TAE) and late (2-4 months after TAE) - follow up. Contrast-enhanced CT was used as standard of reference. Results: The overall presence or absence of fracture on PXR and of hematomas on CT was moderately accurate for arterial injuries in the same segment. Including only fractures with major displacements and larger hematomas increased the specificity to a clinically acceptable level at the cost of reduced sensitivity. Presence of arterial blush on CT was highly specific for arterial injury. Normalization of the Doppler parameters indicated recovery of intrasplenic blood flow by formation of collaterals. CEUS was accurate for detection of significant posttraumatic lesions and grading of the injury severity. Conclusions: In the hemodynamic unstable patient with pelvic injury, PXR is a useful tool for rapid assessment and occlusion of the injured arteries. Contrast enhanced CT of the hemodynamically stable patient can provide the IR with useful information about the site of arterial injury. Normalization of intrasplenic Doppler parameters over time indicates that the use of TAE of the splenic artery is a safe adjunct of the nonoperative management of splenic injury. TAE does not prevent formation of sufficient arterial collaterals. Finally, CEUS may compete with CT in follow-up imaging of posttraumatic lesions of the spleen

Histoire politique de l’administration

Marc Olivier Baruch, directeur d’études avec Jean-Yves Dormagen, maître de conférences à l’Université Paris-I et Vincent Duclert, professeur agrégé Administrations et dictatures L’analyse des administrations ayant servi quelques-uns des régimes – totalitaires ou autoritaires que connut l’Europe du XXe siècle a permis de poursuivre l’étude sociopolitique des pratiques administratives en dictature. On s’est efforcé de mettre en évidence ressemblances, nuances et différences dans les modes d’ins..

Behavioral variation across the days and lives of honey bees

In honey bee colonies, workers generally change tasks with age (from brood care, to nest work, to foraging). While these trends are well established, our understanding of how individuals distribute tasks during a day, and how individuals differ in their lifetime behavioral trajectories, is limited. Here, we use automated tracking to obtain long-term data on 4,100+ bees tracked continuously at 3 Hz, across an entire summer, and use behavioral metrics to compare behavior at different timescales. Considering single days, we describe how bees differ in space use, detection, and movement. Analyzing the behavior exhibited across their entire lives, we find consistent inter-individual differences in the movement characteristics of individuals. Bees also differ in how quickly they transition through behavioral space to ultimately become foragers, with fast-transitioning bees living the shortest lives. Our analysis framework provides a quantitative approach to describe individual behavioral variation within a colony from single days to entire lifetimes

Social networks predict the life and death of honey bees

In complex societies, individuals' roles are reflected by interactions with other conspecifics. Honey bees (Apis mellifera) generally change tasks as they age, but developmental trajectories of individuals can vary drastically due to physiological and environmental factors. We introduce a succinct descriptor of an individual's social network that can be obtained without interfering with the colony. This 'network age' accurately predicts task allocation, survival, activity patterns, and future behavior. We analyze developmental trajectories of multiple cohorts of individuals in a natural setting and identify distinct developmental pathways and critical life changes. Our findings suggest a high stability in task allocation on an individual level. We show that our method is versatile and can extract different properties from social networks, opening up a broad range of future studies. Our approach highlights the relationship of social interactions and individual traits, and provides a scalable technique for understanding how complex social systems function. Honey bee workers take on different tasks for the colony as they age. Here, the authors develop a method to extract a descriptor of the individuals' social networks and show that interaction patterns predict task allocation and distinguish different developmental trajectories

How honeybees respond to heat stress from the individual to colony level

A honey bee colony functions as an integrated collective, with individuals coordinating their behaviour to adapt and respond to unexpected disturbances. Nest homeostasis is critical for colony function; when ambient temperatures increase, individuals switch to thermoregulatory roles to cool the nest, such as fanning and water collection. While prior work has focused on bees engaged in specific behaviours, less is known about how responses are coordinated at the colony level, and how previous tasks predict behavioural changes during a heat stress. Using BeesBook automated tracking, we follow thousands of individuals during an experimentally induced heat stress, and analyse their behavioural changes from the individual to colony level. We show that heat stress causes an overall increase in activity levels and a spatial reorganization of bees away from the brood area. Using a generalized framework to analyse individual behaviour, we find that individuals differ in their response to heat stress, which depends on their prior behaviour and correlates with age. Examining the correlation of behavioural metrics over time suggests that heat stress perturbation does not have a long-lasting effect on an individual’s future behaviour. These results demonstrate how thousands of individuals within a colony change their behaviour to achieve a coordinated response to an environmental disturbance

Texture analysis on diffusion tensor imaging: discriminating glioblastoma from single brain metastasis

BACKGROUND: Texture analysis has been done on several radiological modalities to stage, differentiate, and predict prognosis in many oncologic tumors. PURPOSE: To determine the diagnostic accuracy of discriminating glioblastoma (GBM) from single brain metastasis (MET) by assessing the heterogeneity of both the solid tumor and the peritumoral edema with magnetic resonance imaging (MRI) texture analysis (MRTA). MATERIAL AND METHODS: Preoperative MRI examinations done on a 3-T scanner of 43 patients were included: 22 GBM and 21 MET. MRTA was performed on diffusion tensor imaging (DTI) in a representative region of interest (ROI). The MRTA was assessed using a commercially available research software program (TexRAD) which applies a filtration histogram technique for characterizing tumor and peritumoral heterogeneity. The filtration step selectively filters and extracts texture features at different anatomical scales varying from 2 mm (fine) to 6 mm (coarse). Heterogeneity quantification was obtained by the statistical parameter entropy. A threshold value to differentiate GBM from MET with sensitivity and specificity was calculated by receiver operating characteristic (ROC) analysis. RESULTS: Quantifying the heterogeneity of the solid part of the tumor showed no significant difference between GBM and MET. However, the heterogeneity of the GBMs peritumoral edema was significantly higher than the edema surrounding MET, differentiating them with a sensitivity of 80% and specificity of 90%. CONCLUSION: Assessing the peritumoral heterogeneity can increase the radiological diagnostic accuracy when discriminating GBM and MET. This will facilitate the medical staging and optimize the planning for surgical resection of the tumor and postoperative management

Diagnostic performance of texture analysis on MRI in grading cerebral gliomas

Background and purpose: Grading of cerebral gliomas is important both in treatment decision and assessment of prognosis. The purpose of this study was to determine the diagnostic accuracy of grading cerebral gliomas by assessing the tumor heterogeneity using MRI texture analysis (MRTA). / Material and methods: 95 patients with gliomas were included, 27 low grade gliomas (LGG) all grade II and 68 high grade gliomas (HGG) (grade III = 34 and grade IV = 34). Preoperative MRI examinations were performed using a 3T scanner and MRTA was done on preoperative contrast-enhanced three-dimensional isotropic spoiled gradient echo images in a representative ROI. The MRTA was assessed using a commercially available research software program (TexRAD) that applies a filtration-histogram technique for characterizing tumor heterogeneity. Filtration step selectively filters and extracts texture features at different anatomical scales varying from 2 mm (fine features) to 6 mm (coarse features), the statistical parameter standard deviation (SD) was obtained. Receiver operating characteristics (ROC) was performed to assess sensitivity and specificity for differentiating between the different grades and calculating a threshold value to quantify the heterogeneity. / Results: LGG and HGG was best discriminated using SD at fine texture scale, with a sensitivity and specificity of 93% and 81% (AUC 0.910, p < 0.0001). The diagnostic ability for MRTA to differentiate between the different sub-groups (grade II–IV) was slightly lower but still significant. / Conclusions: Measuring heterogeneity in gliomas to discriminate HGG from LGG and between different histological sub-types on already obtained images using MRTA can be a useful tool to augment the diagnostic accuracy in grading cerebral gliomas and potentially hasten treatment decision

Обеспечение защиты от проявлений атмосферного электричества

Работа направлена на расчеты параметров молнизащиты предприятии социального назначения и расчеты необходимых величин по соответствующим выражениям для построения схемы защиты.The work is aimed at calculating the lightning protection parameters of a social enterprise and calculating the necessary values according to the corresponding expressions for constructing a protection scheme