Anatomical variants of the cervical vertebrae and the first thoracic vertebra in man

Anatomical variants of the cervical part of the human spine were investigated. Morphological variants were studied on 100 cervical vertebrae (37 female and 63 male). The greatest variability was demonstrated by the first cervical vertebra or atlas. The presence of some accessory bony arches embracing the vertebral artery was observed, namely the posterior bridge restraining the arcuate foramen (13.8%) and the lateral bridge restraining the transversovertical foramen (2%). Split posterior (3%) or anterior (1%) arches of the atlas were also encountered in this material. The superior articular face of the atlas divided into two parts was found in 47.8%. Variants of the remaining cervical vertebrae were limited only to the presence of a division of the transverse process foramina or their incomplete closure. Some of these anatomical variants may be a cause of certain clinical symptoms which have previously been described in the literature

Images Influencing Images: How Pictorial Context Affects the Emotional Interpretation of Art Photographs

Images are never seen in isolation. Instead, they are perceived within a spatial and temporal tapestry of neighboring images. What impact do other images have on our emotional response toward a particular image? Answers to this basic question have vital implications for a range of fields—especially for visual communication and for curating art, where resources are invested in arranging images within a visual context. Previous studies have provided mixed results, suggesting that juxtaposed images may lead to contrast or assimilation processes increasing and decreasing our liking of an image. But how specific image features in neighboring images (image’s ambiguity or formal similarities between images) modulate our affective interpretation of an image has almost never been explored. In Study 1, we compared the emotion perceived in art photographs (“target” images) when displayed on their own versus when displayed in juxtaposition with negatively or positively valenced nonart (“context”) images. Additionally, we analyzed the influence of the artwork’s perceived ambiguity. In Study 2, we examined the effect of the perceiver’s expertise and the formal similarity between the images on the rated valence of the target image. Our results show that the emotion perceived in the artwork contrasted away from or assimilated toward the valence perceived in the context image depending on which evaluative dimension was activated. Moreover, the influence of negative contextual material on the target image’s valence was more pronounced. We conclude by saying that the evaluative dimension is part of the pictorial context that influences the affective interpretation of an image

The morphology of the hypoglossal canal and its size in relation to skull capacity in man and other mammal species

The hypoglossal canal is a permanent element of the human skull. As well as the hypoglossal nerve, the canal also contains the venous plexus and an arterial branch leading to the dura mater. It emerged from our earlier studies that the venous plexus is a dominant component in this canal. In the present work the morphology and dimensions of the canal were studied on macerated skulls of humans and animals (rhesus monkey, European bison, fox, dog, cat, hare and rat). The hypoglossal canal was found in all the human and animal skulls examined. In both humans and animals the hypoglossal canal was frequently duplicated. The double canal was found in 43% specimens of human skulls. However, no triple division of the hypoglossal canal was found in the material under investigation. It was found that the hypoglossal canal in man, rhesus monkey and European bison had significant dimensions and in fact correlated with the size of skull capacity. This suggests that the hypoglossal canal is an essential venous emissary in man, rhesus monkey and European bison, but that in the remaining species it is of secondary importance in this respect

Numerical validation of a new method to assess aortic pulse wave velocity from a single recording of a brachial artery waveform with an occluding cuff

Recently a new method has been proposed as a tool to measure arterial pulse wave velocity (PWV), a measure of the stiffness of the large arteries and an emerging parameter used as indicator of clinical cardiovascular risk. The method is based on measurement of brachial blood pressure during supra-systolic pressure inflation of a simple brachial cuff (the device is known as the Arteriograph (Tensiomed, Budapest, Hungary)). This occlusion yields pronounced first and secondary peaks in the pressure waveform, the latter ascribed to a reflection from the aortic bifurcation, and PWV is calculated as the ratio of twice the jugulum-symphysis distance and the time difference between the two peaks. To test the validity of this working principle we used a numerical model of the arterial tree to simulate pressures and flows in the normal configuration, and in a configuration with an occluded brachial artery. A pronounced secondary peak was indeed found in the brachial pressure signal of the occluded model, but its timing was only related to brachial stiffness and not to aortic stiffness. We also compared PWV’s calculated with 3 different methods: PWVATG (~ Arteriograph principle), PWVcar-fem (~ carotid-femoral PWV, the current clinical gold standard method) and PWVtheor (~ Bramwell-Hill equation). Both PWVATG (R²=0.94) and PWVcar-fem (R²=0.95) correlated well with PWVtheor, but their numerical values were lower (by 2.17 ± 0.42 and 1.08 ± 0.70 m/s for PWVATG and PWVcar-fem, respectively). In conclusion, our simulations question the working principle of the Arteriograph. Our data indicate that the method picks up wave reflection phenomena confined to the brachial artery, and derived values of PWV rather reflect the stiffness of the brachial arteries

An animal-specific FSI model of the abdominal aorta in anesthetized mice

Recent research has revealed that angiotensin II-induced abdominal aortic aneurysm in mice can be related to medial ruptures occurring in the vicinity of abdominal side branches. Nevertheless a thorough understanding of the biomechanics near abdominal side branches in mice is lacking. In the current work we present a mouse-specific fluid-structure interaction (FSI) model of the abdominal aorta in ApoE(-/-) mice that incorporates in vivo stresses. The aortic geometry was based on contrast-enhanced in vivo micro-CT images, while aortic flow boundary conditions and material model parameters were based on in vivo high-frequency ultrasound. Flow waveforms predicted by FSI simulations corresponded better to in vivo measurements than those from CFD simulations. Peak-systolic principal stresses at the inner and outer aortic wall were locally increased caudal to the celiac and left lateral to the celiac and mesenteric arteries. Interestingly, these were also the locations at which a tear in the tunica media had been observed in previous work on angiotensin II-infused mice. Our preliminary results therefore suggest that local biomechanics play an important role in the pathophysiology of branch-related ruptures in angiotensin-II infused mice. More elaborate follow-up research is needed to demonstrate the role of biomechanics and mechanobiology in a longitudinal setting

Patient-Specific Computational Modeling of Upper Extremity Arteriovenous Fistula Creation: Its Feasibility to Support Clinical Decision-Making

<div><h3>Introduction</h3><p>Inadequate flow enhancement on the one hand, and excessive flow enhancement on the other hand, remain frequent complications of arteriovenous fistula (AVF) creation, and hamper hemodialysis therapy in patients with end-stage renal disease. In an effort to reduce these, a patient-specific computational model, capable of predicting postoperative flow, has been developed. The purpose of this study was to determine the accuracy of the patient-specific model and to investigate its feasibility to support decision-making in AVF surgery.</p> <h3>Methods</h3><p>Patient-specific pulse wave propagation models were created for 25 patients awaiting AVF creation. Model input parameters were obtained from clinical measurements and literature. For every patient, a radiocephalic AVF, a brachiocephalic AVF, and a brachiobasilic AVF configuration were simulated and analyzed for their postoperative flow. The most distal configuration with a predicted flow between 400 and 1500 ml/min was considered the preferred location for AVF surgery. The suggestion of the model was compared to the choice of an experienced vascular surgeon. Furthermore, predicted flows were compared to measured postoperative flows.</p> <h3>Results</h3><p>Taken into account the confidence interval (25^th and 75^th percentile interval), overlap between predicted and measured postoperative flows was observed in 70% of the patients. Differentiation between upper and lower arm configuration was similar in 76% of the patients, whereas discrimination between two upper arm AVF configurations was more difficult. In 3 patients the surgeon created an upper arm AVF, while model based predictions allowed for lower arm AVF creation, thereby preserving proximal vessels. In one patient early thrombosis in a radiocephalic AVF was observed which might have been indicated by the low predicted postoperative flow.</p> <h3>Conclusions</h3><p>Postoperative flow can be predicted relatively accurately for multiple AVF configurations by using computational modeling. This model may therefore be considered a valuable additional tool in the preoperative work-up of patients awaiting AVF creation.</p> </div

Mendelian randomization integrating GWAS and eQTL data reveals genetic determinants of complex and clinical traits

Genome-wide association studies (GWAS) have identified thousands of variants associated with complex traits, but their biological interpretation often remains unclear. Most of these variants overlap with expression QTLs, indicating their potential involvement in regulation of gene expression. Here, we propose a transcriptome-wide summary statistics-based Mendelian Randomization approach (TWMR) that uses multiple SNPs as instruments and multiple gene expression traits as exposures, simultaneously. Applied to 43 human phenotypes, it uncovers 3,913 putatively causal gene-trait associations, 36% of which have no genome-wide significant SNP nearby in previous GWAS. Using independent association summary statistics, we find that the majority of these loci were missed by GWAS due to power issues. Noteworthy among these links is educational attainment-associated BSCL2, known to carry mutations leading to a Mendelian form of encephalopathy. We also find pleiotropic causal effects suggestive of mechanistic connections. TWMR better accounts for pleiotropy and has the potential to identify biological mechanisms underlying complex traits

Energy Resolution Performance of the CMS Electromagnetic Calorimeter

The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals