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BVH construction is a critical component of real‐time and interactive ray‐tracing systems. However, BVH construction can be both compute and bandwidth intensive, especially when a large degree of dynamic geometry is present. Different build algorithms vary substantially in the traversal performance that they produce, making high quality construction algorithms desirable. However, high quality algorithms, such as top‐down construction, are typically more expensive, limiting their benefit in real‐time and interactive contexts. One particular challenge of high quality top‐down construction algorithms is that the large working set at the top of the tree can make constructing these levels bandwidth‐intensive, due to O(nlog(n)) complexity, limited cache locality, and less dense compute at these levels. To address this limitation, we propose a novel stochastic approach to GPU BVH construction that selects a representative subset to build the upper levels of the tree. As a second pass, the remaining primitives are clustered around the BVH leaves and further processed into a complete BVH. We show that our novel approach significantly reduces the construction time of top‐down GPU BVH builders by a factor up to 1.8×, while achieving competitive rendering performance in most cases, and exceeding the performance in others. [ABSTRACT FROM AUTHOR]

Copyright of Acta Medica Croatica is the property of Croatian Academy of Medical Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents guideline for liquid and foam sclerotherapy drafted on behalf of 23 European Phlebological Societies during a Guideline Conference in Mainz, Germany from May 7-10, 2012. The guideline focuses on sclerosing drugs, sodium tetradecyl sulphate and polidocanol, which are licensed in the majority countries of Europe. The guideline offers recommendations regarding efficacy, side-effects and indications of foam and liquid sclerotherapy of venous malformations and varicose veins.

Introduction: Foam sclerotherapy has gained a great popularity among phlebologists worldwide, although a major lack of homogeneity in the material used to produce sclerosant foam (SF) and to inject SF has been reported. Aims: To highlight the literature data and a few personal clinical and experimental outcomes concerning the main variables in SF production and injection. Methods: A review of the published literature and of our own 12 year clinical and experimental experience has been undertaken in order to focus on a few variables of the material and methods used to produce SF with Tessari method and to inject SF. Results: In SF production, differences in gas components, liquid to gas ratio, as well in disposable material can variably influence the resulting SF. Similarly SF injection through ultrasound guidance, with needle, or with short/long catheter may exhibit different foam behaviours according to the variable material and techniques which are employed. More recently the introduction of long catheters, possibly together with hook phlebectomy, seems to potentiate the short-mid term outcomes of foam sclerotherapy. Conclusion: SF formation is greatly influenced by the choice of the gas component, the liquidto- gas ratio, the type of syringes; also larger needles are to be preferred for injection of SF, while long catheters seem to represent a valid alternative especially when combined with tumescence to minimise saphenous diameter. [ABSTRACT FROM AUTHOR]

Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The role of SEPs in motor prognosis of hypoxic–ischemic neonatal encephalopathy has been evaluated in pre-hypothermia era (Suppiej, 2010) but their role in babies treated with hypothermia has not been studied yet. We investigated motor outcome at 12 months of age in 38 children who suffered from hypoxic–ischemic neonatal encephalopathy and were treated with hypothermia at the NICU of the Paediatric University Hospital of Padua. All performed median nerve SEPs in the neonatal period, traces were scored as bilaterally present (group1) or as bilaterally/unilaterally absent (group2) cortical N20 response. At follow up 4/38 children had the diagnosis of cerebral palsy (all of them had bilaterally absent cortical SEP). Of the remaining 34, 7 had abnormal (<5°) scores at the motor subscales of the Griffith’s Scale. A significant difference was found between motor scores of group 1 (mean 97 DS 13) and group2 (mean 82 SD 14) ( p = .023 Mann–Whitney test). Data seem to suggest a prognostic value of SEPs to predict neuromotor outcome as evaluated with Griffiths Scale at one year of age. However, these results need to be confirmed at 24 months of age when clinical prognosis is known to be more reliable. [ABSTRACT FROM AUTHOR]

Bilateral loss of N20 predicts cerebral palsy in neonatal hypoxic ischemic encephalopathy (Suppiej, 2010). The diffusion, in the last years, of the hypothermic treatment in this condition, requires to reevaluate their prognostic role and timing of SEPs. Aim of this study is to evaluate the most appropriate timing during which to perform the evoked potentials. Twelve newborns underwent median nerve SEPs during hypothermia (33.5 °C), and subsequently between the 5th and the 14th day of life. Of the 12 newborns studied the N20 was bilaterally absent during hypothermia in 6, but bilaterally present in normothermia in 4, the remaining 2 died before the control SEP. Only in 1/12 the N20 was bilaterally recorded during hypothermia. In 3cases the N20 was absent unilaterally, in 2/3 was subsequently recorded bilaterally while in 1/3 persisted unilaterally absent; this neonate had an ipsilateral stroke. Since bilateral absence of cortical SEPs performed at the end of the first week of life was shown to predict cerebral palsy later in life, the discrepancy between the SEPs recorded during hypothermia and the SEPs recorded once normothermia has been attained, suggest a low prognostic value of SEPs recorded during hypothermia, differently from adults (Zanatta, 2012). [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate Brainstem Auditory Evoked Potentials (BAEPs) in perinatal asphyxtic infants, performed during and/or after therapeutic hypothermia (TH). A group of 27 patients enrolled for TH secondary to perinatal asphyxiated performed BAEPs: 8 pt during and after TH; 8 pt during TH and 11 pt only after TH. For all BAEPS absolute latency and Interpeak latencies (IPL) were evaluated. One patient, died after TH, showed absence of all bilateral waves. Another patient showed monolateral absence of III–V waves. The other 25 patients showed normal BAEPS. Patients, who performed BAEPS during and after TH (7 pt), presented a significant reduction of absolute latency and IPL after TH. Cooling seems to increase absolute and interpeak latencies of Brainstem Evoked Potentials, regarding peripheral VIII nerves and central generators. [ABSTRACT FROM AUTHOR]