17,138 research outputs found
Challenges in video based object detection in maritime scenario using computer vision
This paper discusses the technical challenges in maritime image processing
and machine vision problems for video streams generated by cameras. Even well
documented problems of horizon detection and registration of frames in a video
are very challenging in maritime scenarios. More advanced problems of
background subtraction and object detection in video streams are very
challenging. Challenges arising from the dynamic nature of the background,
unavailability of static cues, presence of small objects at distant
backgrounds, illumination effects, all contribute to the challenges as
discussed here
Visualisation of an entangled channel spin-1 system
Co-variance matrix formalism gives powerful entanglement criteria for
continuous as well as finite dimensional systems. We use this formalism to
study a mixed channel spin-1 system which is well known in nuclear reactions. A
spin-j state can be visualized as being made up of 2j spinors which are
represented by a constellation of 2j points on a Bloch sphere using Majorana
construction. We extend this formalism to visualize an entangled mixed spin-1
system.Comment: 4 pages,4 figure
Arbitrarily large families of spaces of the same volume
In any connected non-compact semi-simple Lie group without factors locally
isomorphic to SL_2(R), there can be only finitely many lattices (up to
isomorphism) of a given covolume. We show that there exist arbitrarily large
families of pairwise non-isomorphic arithmetic lattices of the same covolume.
We construct these lattices with the help of Bruhat-Tits theory, using Prasad's
volume formula to control their covolumes.Comment: 9 pages. Syntax corrected; one reference adde
MELAS: A multigenerational impact of the MTTL1 A3243G MELAS mutation
Background: the maternally inherited MTTL1 A3243G mutation in the mitochondrial genome causes MelaS (Mitochondrial encephalopathy lactic acidosis with Stroke-like episodes), a condition that is multisystemic but affects primarily the nervous system. Significant intra-familial variation in phenotype and severity of disease is well recognized. Methods: retrospective and ongoing study of an extended family carrying the MTTL1 A3243G mutation with multiple symptomatic individuals. tissue heteroplasmy is reviewed based on the clinical presentations, imaging studies, laboratory findings in affected individuals and pathological material obtained at autopsy in two of the family members. Results: there were seven affected individuals out of thirteen members in this three generation family who each carried the MTTL1 A3243G mutation. the clinical presentations were varied with symptoms ranging from hearing loss, migraines, dementia, seizures, diabetes, visual manifestations, and stroke like episodes. three of the family members are deceased from MelaS or to complications related to MelaS. Conclusions: the results of the clinical, pathological and radiological findings in this family provide strong support to the current concepts of maternal inheritance, tissue heteroplasmy and molecular pathogenesis in MelaS. neurologists (both adult and paediatric) are the most likely to encounter patients with MelaS in their practice. genetic counselling is complex in view of maternal inheritance and heteroplasmy. newer therapeutic options such as arginine are being used for acute and preventative management of stroke like episodes. © 2014 Canadian Journal of neurologiCal sciences inc
Preparation and characterisation of free flowing solid lipid based drug delivery systems using a twin screw extruder
In this study, a continuous manufacturing process was developed for adsorbing liquid self-emulsifying drug delivery system (SEDDS) on mesoporous silica carriers in order to produce solid free flowing SEDDS powders. An optimized liquid SEDDS, consisting of Labrafil M 1944 CS, Labrasol and Capryol 90 (15, 80, 5 %w/w), was developed. The formulation spontaneously formed a homogenous emulsion with a droplet size of less than 200 nm (in water) and possessed pH robustness (pH 1.2, pH 6.8). Two grades of mesoporous silica were investigated as solid carriers, namely Syloid XDP 3050 and 3150. A twin screw extruder, setup in the granulation configuration, was employed to assess the mixing and adsorption of liquid SEDDS onto silica particles in a continuous process. Screw configuration, ratio of solid carrier to liquid SEDDS, powder and liquid feed rates and screw speed were identified as important parameters. These parameters were tested and optimized to achieve free flowing solid SEDDS. The maximum lipid loading of Syloid XDP 3050 and 3150 was 1:2 and 1:2 to less than 1:3 ratios, respectively. Although increasing liquid SEDDS loading increased the cohesive properties of the silica particles, the resulting powders afforded acceptable flow rate indexes as determined by powder rheometry. Similar self-emulsification behaviour was observed for solid and liquid SEDDS. With increasing lipid loading, the droplet size of emulsified solid SEDDS increased and changed from a unimodal to a bimodal size distributions. This effect was more pronounced for Syloid XDP3050. Syloid XDP 3150 was less sensitive to droplet size changes as its z-average diameters at 1:2-1:3 ratio were similar to the optimized liquid SEDDS. Targeting a lipid loading ratio of 2:1, process parameters were varied to maximise material throughput. The investigated continuous process of adsorbing liquid SEDDs onto solid carriers produced solid SEDDS with good flow properties. Syloid XDP 3150 seemed more robust to the process than Syloid XDP 3050
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