A Pixel Vertex Tracker for the TESLA Detector

In order to fully exploit the physics potential of a e+e- linear collider, such as TESLA, a Vertex Tracker providing high resolution track reconstruction is required. Hybrid Silicon pixel sensors are an attractive sensor technology option due to their read-out speed and radiation hardness, favoured in the high rate TESLA environment, but have been so far limited by the achievable single point space resolution. A novel layout of pixel detectors with interleaved cells to improve their spatial resolution is introduced and the results of the characterisation of a first set of test structures are discussed. In this note, a conceptual design of the TESLA Vertex Tracker, based on hybrid pixel sensors is presentedComment: 20 pages, 11 figure

Characterisation of Hybrid Pixel Detectors with capacitive charge division

In order to fully exploit the physics potential of the future high energy e+ e- linear collider, a Vertex Tracker providing high resolution track reconstruction is required. Hybrid pixel sensors are an attractive technology due to their fast read-out capabilities and radiation hardness. A novel pixel detector layout with interleaved cells between the readout nodes has been developed to improve the single point resolution. The results of the characterisation of the first processed prototypes are reported.Comment: 5 pages, 2 figures, presented at LCWS2000, Linear Collider Workshop, October 24-28 2000, Fermi National Accelerator Laboratory, Batavia, Illinois, U.S.A. Proceedings to be published by the American Institute of Physic

Longitudinal stability augmentation of seaplanes in planing

The towing tank experiments conducted at Yokohama National University from November 30 to December 9 in 2005 suggested a new way of suppressing a dangerous coupled motion between heave and pitch called porpoising. The research in this paper was developed on the observations made in the experiments and conducted numerical simulations to further investigate the parametric design space. Two linear-time-invariant models were developed: rigid-body planing craft (conventional float planes or flying boats), and flexibly supported planing craft. The latter could simulate the new method found in the experiments for suppressing porpoising. In this study, the stability of the oscillatory motions was analyzed to see the effect of design variables on the inception of porpoising. The parametric study of flexibly supported float planes in the context of porpoising was a new contribution in the conceptual design of seaplanes

Anatomic variability of groin innervation

Inguinal hernia repairs are very common yet fairly complex surgical procedures.Variations in the anatomical course of the inguinal nerves require that diligenceis taken in their proper recognition. Inadvertent surgical injury to these nerves isassociated with long term postoperative pain and complications. The aim of thepresent study was to highlight the complexity and variation in the innervation ofthe inguinal region in order to increase proper nerve identification during surgicalinterventions. Bilateral dissection of the inguinal and posterior abdominal regionsin one human male cadaver revealed an atypical anatomic topography of thegroin innervation. This unusual case was observed at the Jagiellonian UniversityAnatomy Department during routine cadaveric preparations. The left ilioinguinalnerve was absent. The left genital branch of the genitofemoral nerve arose higherthan expected from the lumbar plexus and supplied the groin region, which istypically innervated by the ilioinguinal nerve. Furthermore, the left lateral cutaneousfemoral nerve and the right genital branch of the genitofemoral nerve alsofollowed uncharacteristic courses. Awareness of topographical nerve variationsduring inguinal hernia repair will help surgeons identify and preserve importantnerves, thus decreasing the incidence of chronic postoperative pain

Configurations of the circle of Willis: a computed tomography angiography based study on a Polish population

The aim of the study was to investigate the distribution of the circle of Willis variants in Polish population by means of computed tomography angiography (CTA). The results were then analysed and compared with another study that used similar methods but that was carried out on an ethnically distinct population. Patients presenting with intracranial pathology were excluded from the initial study population. In total, 250 CTA belonging to 129 female and 121 male patients were reviewed. A modified classification system of the circle was proposed, which took into consideration the anterior and the posterior aspects of the circle individually. The typical variant of Willis’s circle occurred in 16.80% of cases. The anterior and the posterior portions of the circle were normal in 47.20% and 26.80% of the patients respectively. As forthe anterior part, lack of the anterior communicating artery was the most frequent abnormality (22.80%). Bilateral absence of posterior communicating arteries was the most common anomaly in the posterior part of the circle (29.20%). This type of anomaly was also the most common, when taking into consideration the entire circle (12.00%). There were statistically significant differences between the age groupsand genders when considering the occurrence of an incomplete circle. Overall, a substantial proportion of patients manifested clinically important variants that were incapable of providing collateral circulation. Comparison with other imaging-based and cadaveric studies revealed noticeable differences, that may have resulted from the variable technical features of other studies or other factors such as the ethnical origins of the studied populations

The variable origin of the lateral circumflex femoral artery: a meta-analysis and proposal for a new classification system

The lateral circumflex femoral artery (LCFA) is responsible for vascularisation of the head and neck of the femur, greater trochanter, vastus lateralis and the knee. The origin of the LCFA has been reported to vary significantly throughout the literature, with numerous branching patterns described and variable distances to the mid-inguinal point reported. The aim of this study was to determine the estimated population prevalence and pooled means of these anatomical characteristics, and review their associated clinical relevance. A search of the major electronic databases was performed to identify all articles reporting data on the origin of the lateral circumflex femoral artery and its distance to the mid-inguinal point. Additionally, an extensive search of the references of all relevant articles was performed. All data on origin, branching, and distance to mid-inguinal point was extracted and pooled into a meta-analysis. A total of 26 articles (n = 3731 lower limbs) were included in the meta-analysis. Lateral circumflex femoral artery most commonly originates from the deep femoral artery with a pooled prevalence of 76.1% (95% confidence interval 69.4–79.3). The deep femoral artery-derived lateral circumflex femoral artery was found to originate with a mean pooled distance of 51.06 mm (95% confidence interval 44.61–57.51 mm) from the mid-inguinal point. Subgroup analysis of both gender and limb side data were consistent with these findings. Due to variability in the lateral circumflex femoral artery’s origin and distance to mid-inguinal point, anatomical knowledge is crucial for clinicians to avoid iatrogenic injuries when performing procedures in the femoral region, and thus radiographic assessment prior to surgery is recommended. Lastly, we propose a new classification system for origin of the lateral circumflex femoral arter

‘Venous lakes’ — a corrosion cast scanning electron microscopy study of regular and myomatous human uterine blood vessels

Background: The aim of this study was to evaluate the venous structure of regularand myomatous human uteri, using corrosion casting and scanning electron microscopy (SEM). Special attention was paid to the endometrium and the socalled ‘venous lakes’.Materials and methods: Uteri collected at autopsy (n = 67) were injected with Mercox CL-2R resin, which penetrated the capillary bed and filled both arteriesand veins. After the polymerisation of the resin, the corrosion was performed. The obtained vascular casts, visualising all vessels including capillaries, were examinedusing scanning electron microscopy.Results: Amongst the 67 uteri prepared for the corrosion casting, only 22 (15 containing leiomyomata) yielded casts of acceptable quality for SEM assessment. Veins of the endometrium and the myometrium were present in the form of a chaotic network, which did not run parallel to the arterialsystem, but was rather independent. Microscopic venous dilations (‘venouslakes’) were observed both within the functional layer of the endometrium and the myometrium. They were digit-like in shape and could be compared to venous sinuses. They drained the subendothelial capillary plexus and were supplied by numerous capillaries and venules. Their size ranged from 270 to 420 μm. Those dilatations were absent in the outer myometrium and the perimetrium, as well as the uterine cervix. We have not observed any arteriovenous anastomoses.Conclusions: The myomatous uteri tend to have larger venous lakes than the normal uteri. The number and size of venous lakes increases with menstrual cycle progression. Further data on morphology and changes in venous lakesusing scanning electronic microscopy should be acquired

Thresholds for clinical importance for four key domains of the EORTC QLQ-C30 : physical functioning, emotional functioning, fatigue and pain

Background The EORTC QLQ-C30 is one of the most widely used quality of life questionnaires in cancer research. Availability of thresholds for clinical importance for the individual questionnaire domains could help to increase its interpretability. The aim of our study was to identify thresholds for clinical importance for four EORTC QLQ-C30 scales: Physical Functioning (PF), Emotional Functioning (EF), Pain (PA) and Fatigue (FA). Methods We recruited adult cancer patients from Austria, the Netherlands, Poland and the UK. No restrictions were placed on diagnosis or type or stage of treatment. Patients completed the QLQ-C30 and three anchor items reflecting potential attributes of clinically important levels of PF, EF, PA and FA. We merged the anchor items assessing perceived burden, limitations in daily activities and need for help into a dichotomous external criterion to estimate thresholds for clinical importance using Receiver Operator Characteristic (ROC) analysis. Results In our sample of 548 cancer patients (mean age 60.6 years; 54 % female), the QLQ-C30 scales showed high diagnostic accuracy in identifying patients reporting burden, limitations and/or need for help related to PF, EF, PA and FA. All areas under the curve were above 0.86. Conclusions We were able to estimate thresholds for clinical importance for four QLQ-C30 scales. When used in daily clinical practice, these thresholds can help to identify patients with clinically important problems requiring further exploration and possibly intervention by health care professionals

Volumetric reconstruction of the right ventricle improves reproducibility of interventricular septum bowing in patients with pulmonary embolism

Bowing of the interventricular septum (IVS) is a sign of severe pulmonary embolism(PE); however, it is affected by high interobserver variability. The aim of thestudy was to evaluate the application of volumetric reconstructions of the rightventricle for assessment of IVS position regarding its accuracy in identifying rightventricular dysfunction, as well as interobserver agreement in evaluating this sign.IVS bowing was evaluated with multiplanar reformations (MPR) and volumetricreconstruction (VR, volume rendering) by 2 observers. The accuracy of IVS bowingsign was better for VR-based assessment; however, it was not significantlybetter than the MPR-based evaluation. Interobserver agreement was found tobe fair (kappa = 0.381) for the MPR-based grading of IVS position as normal orabnormal, while it was significantly better for the VR method (kappa = 0.629,p < 0.001). The VR-based method may improve utilisation of IVS bowing sign inpatients with PE

Do wind turbines pose roll hazards to light aircraft?

Wind energy accounted for 5.6&thinsp;% of all electricity generation in the United States in 2016. Much of this development has occurred in rural locations, where open spaces favorable for harnessing wind also serve general aviation airports. As such, nearly 40&thinsp;% of all United States wind turbines exist within 10&thinsp;km of a small airport. Wind turbines generate electricity by extracting momentum from the atmosphere, creating downwind wakes characterized by wind-speed deficits and increased turbulence. Recently, the concern that turbine wakes pose hazards for small aircraft has been used to limit wind-farm development. Herein, we assess roll hazards to small aircraft using large-eddy simulations (LES) of a utility-scale turbine wake. Wind-generated lift forces and subsequent rolling moments are calculated for hypothetical aircraft transecting the wake in various orientations. Stably and neutrally stratified cases are explored, with the stable case presenting a possible worst-case scenario due to longer-persisting wakes permitted by lower ambient turbulence. In both cases, only 0.001&thinsp;% of rolling moments experienced by hypothetical aircraft during down-wake and cross-wake transects lead to an increased risk of rolling.</p