77 research outputs found

    Supraorbital transciliary keyhole approach for removal of tuberculum sellae meningioma: 3D surgical video

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    Background: Tuberculum sellae meningiomas have an incidence from 5 to 10% of all intracranial meningiomas[2] and tend to be surgically difficult and challenging tumors given their proximity to important structures such as the internal carotid artery (ICA), anterior cerebral artery (ACA), and optic nerves.[3] Typically, their growth is posteriorly and superiorly oriented, thereby displacing the optic nerves and causing visual dysfunction, which is the primary indication for surgical treatment.[1] The main goals of the treatment are the preservation or restoration of visual abilities and a complete tumor resection.[1] Conventionally, surgical approaches to tuberculum meningiomas involve largely invasive extended bifrontal, interhemispheric, orbitozygomatic, pterional, and subfrontal eyebrow approaches. The supraorbital craniotomy, however, is a minimally invasive transcranial approach that offers a similar surgical corridor to conventional transcranial approaches, using a limited craniotomy and minimal brain retraction that can be used for tumoral and vascular pathologies,[4,5] offering added cosmetic outcomes.[1] We present the case of a patient undergoing a supraorbital transciliary craniotomy with a tuberculum sellae meningioma causing bitemporal hemianopsia. Case description: A 70-year-old female with chronic headaches and progressive vision loss and visual field deficit for about 1 year. On ophthalmological evaluation, she was able to fixate and follow objects with each eye, light perception was only present in the right eye, and the vision in the left eye was 0.2 decimal units. Her visual fields demonstrated severe campimetric deficits. Her extraocular movements were intact and bilateral pupils were equal, round, and reactive to light. MRI of the brain demonstrated tuberculum sellae meningioma with bilateral optic canal invasion, displacing the chiasm, and extending ≥180° around the medial ICA wall and anterior ACA wall. The patient underwent supraorbital transciliary keyhole approach for total resection of the tumor. Postoperatively, visual acuity and visual field were significantly improved. Conclusion: Performing a supraorbital transciliary keyhole craniotomy for tuberculum sellae meningiomas requires an adequate and meticulous preoperative planning to determine the optimal surgical corridor to the lesion. The use of supraorbital craniotomy is safe with good cosmetic results and potentially lower morbidity allowing for adequate exposure, resection, and release of neurovascular structures

    Hippobosca longipennis - a potential intermediate host of a species of Acanthocheilonema in dogs in northern India

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    Background Hippobosca longipennis (the 'dog louse fly') is a blood sucking ectoparasite found on wild carnivores such as cheetahs and lions and domesticated and feral dogs in Africa, the Middle East and Asia, including China. Known as an intermediate host for Acanthocheilonema dracunculoides and a transport host for Cheyletiella yasguri, it has also been suggested that H. longipennis may be a vector for other pathogens, including Acanthocheilonema sp.? nov., which was recently reported to infect up to 48% of dogs in northern India where this species of fly is known to commonly infest dogs. To test this hypothesis, hippoboscid flies feeding on dogs in Ladakh in northern India were collected and subjected to microscopic dissection. Results A total of 12 infective larvae were found in 10 out of 65 flies dissected; 9 from the head, 2 from the thorax and 1 from the abdomen. The larvae averaged 2, 900 (± 60) μm in length and 34 (± 5) μm in width and possessed morphological features characteristic of the family Onchocercidae. Genetic analysis and comparison of the 18S, ITS-2, 12S and cox-1 genes confirmed the identity of the larvae as the Acanthocheilonema sp.? nov. reported in dogs in Ladakh. Conclusion This study provides evidence for a potential intermediate host-parasite relationship between H. longipennis and the canine Acanthocheilonema sp.? nov. in northern India

    How reproducible are methods to measure the dynamic viscoelastic properties of poroelastic media?

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    There is a considerable number of research publications on the acoustical properties of porous media with an elastic frame. A simple search through the Web of Science™ (last accessed 21 March 2018) suggests that there are at least 819 publications which deal with the acoustics of poroelastic media. A majority of these researches require accurate knowledge of the elastic properties over a broad frequency range. However, the accuracy of the measurement of the dynamic elastic properties of poroelastic media has been a contentious issue. The novelty of this paper is that it studies the reproducibility of some popular experimental methods which are used routinely to measure the key elastic properties such as the dynamic Young's modulus, loss factor and Poisson ratio of poroelastic media. In this paper, fourteen independent sets of laboratory measurements were performed on specimens of the same porous materials. The results from these measurements suggest that the reproducibility of this type of experimental method is poor. This work can be helpful to suggest improvements which can be developed to harmonize the way the elastic properties of poroelastic media are measured worldwide

    Statutory Interpretation as Argumentation

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    This chapter proposes a dialectical approach to legal interpretation, consisting of three dimensions: a formalization of the canons of interpretation in terms of argumentation schemes; a dialectical classification of interpretive schemes; and a logical and computational model for comparing the arguments pro and contra an interpretation. The traditional interpretive maxims or canons used in both common and civil law are translated into defeasible patterns of arguments, which can be evaluated through sets of corresponding critical questions. These interpretive argumentation schemes are classified in general categories and a distinction is drawn between schemes supporting and rebutting an interpretation. This framework allows conceiving statutory interpretation as a dialectical procedure consisting in weighing arguments pro and contra an interpretation. This procedure is formalized and represented computationally through tools from formal argumentation systems
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