Guided-MLESAC: faster image transform estimation by using matching priors

MLESAC is an established algorithm for maximum-likelihood estimation by random sampling consensus, devised for computing multiview entities like the fundamental matrix from correspondences between image features. A shortcoming of the method is that it assumes that little is known about the prior probabilities of the validities of the correspondences. This paper explains the consequences of that omission and describes how the algorithm's theoretical standing and practical performance can be enhanced by deriving estimates of these prior probabilities. Using the priors in guided-MLESAC is found to give an order of magnitude speed increase for problems where the correspondences are described by one image transformation and clutter. This paper describes two further modifications to guided-MLESAC. The first shows how all putative matches, rather than just the best, from a particular feature can be taken forward into the sampling stage, albeit at the expense of additional computation. The second suggests how to propagate the output from one frame forward to successive frames. The additional information makes guided-MLESAC computationally realistic at video-rates for correspondence sets modeled by two transformations and clutter.     

Multiple paths extraction in images using a constrained expanded trellis

Single shortest path extraction algorithms have been used in a number of areas such as network flow and image analysis. In image analysis, shortest path techniques can be used for object boundary detection, crack detection, or stereo disparity estimation. Sometimes one needs to find multiple paths as opposed to a single path in a network or an image where the paths must satisfy certain constraints. In this paper, we propose a new algorithm to extract multiple paths simultaneously within an image using a constrained expanded trellis (CET) for feature extraction and object segmentation. We also give a number of application examples for our multiple paths extraction algorithm.     

Coral recovery at Aldabra Atoll, Seychelles: five years after the 1998 bleaching event

Changes in reef benthos were assessed at Aldabra Atoll following the mass coral bleaching event of 1998. Video transects were used to survey the benthos and analysed using the Australian Institute of Marine Science five-dot method. Comparison of coral cover data collected by the Cambridge Southern Seychelles Atoll Research Programme with data collected during this study revealed that mortality of coral at Aldabra following the bleaching event was approximately 66% at 10 m depth and 38% at 20 m depth. Five years on, there are signs of hard coral recovery at some locations, but in spite of several years of high coral recruitment (7-9 recruits per m2 at 10 m depth, 4-6 recruits per m2 at 20 m depth, where recruits are defined as any colony under 5 cm maximum diameter), recovery of hard coral has not occurred at a significant level. There has been a considerable increase in soft coral cover at some locations, which was dominated by the genus Rhytisma. Macro algal cover did not increase following the bleaching event, although, as would be expected, dead corals have been colonized by coralline algae. There have been no further events leading to large-scale coral mortality at Aldabra since 1998.     

A general in situ hydrothermal rolling-up formation of one-dimensional, single-crystalline lead telluride nanostructures

In this study we demonstrate that one-dimensional (1D) nanostructured lead telluride (PbTe) can be synthesized in a hydrothermal reaction between lead foil and tellurium powder. The resulting materials were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The formation of the 1D structure can be explained by an in situ hydrothermal rolling-up mechanism whereby PbTe is formed hydrothermally and deposited on the lead substrate. The lead underneath the PbTe layer is then selectively etched by a cetyltrimethylammonium bromide solution, thus allowing the PbTe to roll up into 1D structures. This method can be extended to prepare other 1D tellurides, including CdTe, Cu(2)Te, and Ag(2)Te.     

New ceramides from <Emphasis Type="Italic">Rantherium suaveolens</Emphasis>

A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S, 3S, 4R, 2′R, 14E)-2-(2′-hydroxydocosanoylamino)-14-octadecene-1,3,4-triol (1), (2S,3S,4R,2′R, 14F)-2-(2′-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol (2), (2S,3S,4R,2′R,14F)-2-(2′-hydroxytetracosanoylamino)-14-octadecene-1,3,4-triol (3), (2S,3S,4R,2′R,14E)-2-(2′-hydroxypentacosanoylamino)-14-octadecene-1,3,4-triol (4), and (2S,3S,4R,2′R,14E)-2-(2′-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol (5).     

Vapochromism of Hexaphenylsilole

The photoluminescence (PL) of the thin layer of hexaphenylsilole (HPS) on thin-layer chromatograph (TLC) or quartz plate is investigated. The PL of the HPS layer absorbed on the TLC plate can be turned “off” and “on” continuously and reversibly by solvent exposure and evaporation. On the other hand, the PL of the HPS film coated on the quartz plate becomes stronger with a blue-shift in its emission color after fumigation by solvent vapor. After solvent removal, the film does not return to its original blue-green emission. Analyses by SEM, TEM and XRD indicate that the transformation from amorphous to crystalline state is responsible for the vapor-induced stronger and bluer PL.     

Memory impairment on the ascending and descending limbs of the blood alcohol curve.

Investigated the effects of alcohol on memory using a free-recall verbal memory task. Male medical students were randomly assigned to alcohol or placebo groups (n = 20). Alcohol Ss were tested before alcohol (baseline) and on the ascending and descending limbs of the blood alcohol curve at a blood alcohol level of .09%. Placebo Ss were tested at 3 comparable times. Alcohol impaired immediate, short-term, and long-term memory for words presented during the alcohol state. However, there was no effect of alcohol on recall of baseline words either during the alcohol state or the next day. The impairment in long-term memory was due primarily to the deficit in short-term memory and not to state-dependent effects. Immediate memory was more impaired on the ascending than on the descending limb of the blood alcohol curve, while short-term memory did not demonstrate this differential impairment. Possible mechanisms responsible for these effects of alcohol on memory are discussed in terms of EEG and biochemical factors related to memory retrieval and consolidation. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Digitales Dichtemeßverfahren zum Bestimmen der enzymatischen Reaktionsgeschwindigkeiten

European Food Research and Technology - Ein neues digitales Dichtemeßverfahren zum Bestimmen der enzymatischen Reaktionsgeschwindigkeit wurde entwickelt, durch das die Reaktionskinetik sehr...     

Renin-aldosterone axis and arginine-vasopressin responses to sodium depletion in camels

778 fecal samples from 29 Jordanian sheep flocks were examined for the presence of Clostridium perfringens. 252 field strains were isolated and typed by the enzyme immunosorbent assay. The presence of C. perfringens types B, C and D in Jordanian sheep was confirmed. Type D was found in 55% of the flocks examined. Types B and C were each isolated from 7% of the flocks examined. The proteinase activity of isolated type B field strains was similar to that of type B reference strains. According to the results, it does not seem to be necessary to include locally isolated C. perfringens strains in the Jordanian vaccine production.