View-based approaches to spatial representation in human vision

In an immersive virtual environment, observers fail to notice the expansion of a room around them and consequently make gross errors when comparing the size of objects. This result is difficult to explain if the visual system continuously generates a 3-D model of the scene based on known baseline information from interocular separation or proprioception as the observer walks. An alternative is that observers use view-based methods to guide their actions and to represent the spatial layout of the scene. In this case, they may have an expectation of the images they will receive but be insensitive to the rate at which images arrive as they walk. We describe the way in which the eye movement strategy of animals simplifies motion processing if their goal is to move towards a desired image and discuss dorsal and ventral stream processing of moving images in that context. Although many questions about view-based approaches to scene representation remain unanswered, the solutions are likely to be highly relevant to understanding biological 3-D vision

Lessons from an initiative to address gender bias

How a letter addressing the lack of women invited to speak at a conference in brain stimulation encouraged researchers to take action

Pseudomonas Sp. Strain PG2982: Uptake of Glyphosate and Cloning of a Gene Which Confers Increased Resistance to Glyphosate.

Chapter 1. Pseudomonas sp. strain PG2982 has the ability to use the phosphonate herbicide, glyphosate, as a sole phosphorus source. Glyphosate uptake occurs at a maximum in the late log phase of growth and is induced by phosphate starvation. Uptake is inhibited by phosphate and arsenate, but not by the amino acids glycine and sarcosine. The K\sb{\rm m} and V\sb{\rm max} for glyphosate uptake were calculated to be 23uM and 0.97nmoles/mg dry wt/min, respectively. A phosphate transport system with a broad substrate specificity seems to be responsible for glyphosate uptake. Chapter 2. Pseudomonas sp. strain PG 2982 is highly resistant to the herbicide glyphosate, a potent inhibitor of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). In addition, PG2982 is able to utilize glyphosate as a sole source of phosphorus. A plasmid carrying a 2.4-kilobase pair (kb) fragment of DNA from PG2982 capable of increasing the glyphosate resistance of E. coli cells has been isolated by selection in media containing 2mM glyphosate. The increase in resistance is dependent upon the presence of a plasmid-encoded protein with a molecular weight of approximately 33,000. This protein is the product of a translational fusion between a gene on the vector, pACYC184, and the insert DNA. A lambda clone carrying the entire gene from PG2982 has been isolated and subcloning of a 2kb DNA fragment carrying this gene has again resulted in a plasmid, pPG18, capable of increasing glyphosate resistance in E. coli. A protein with a molecular weight of approximately 40,000 is encoded by pPG18. This plasmid is not able to complement a mutation in the gene for EPSPS in E. coli strain LC3 and will not hybridize to the E. coli gene. Also, the glyphosate can not be broken down by E. coli cells containing the plasmid. The nucleotide sequence of the gene has revealed the presence of an open reading frame able to encode a protein with a calculated molecular weight of 39,396

Development of functional organization within the sensorimotor network across the perinatal period

In the mature human brain, the neural processing related to different body parts is reflected in patterns of functional connectivity, which is strongest between functional homologs in opposite cortical hemispheres. To understand how this organization is first established, we investigated functional connectivity between limb regions in the sensorimotor cortex in 400 preterm and term infants aged across the equivalent period to the third trimester of gestation (32–45 weeks postmenstrual age). Masks were obtained from empirically derived functional responses in neonates from an independent data set. We demonstrate the early presence of a crude but spatially organized functional connectivity, that rapidly matures across the preterm period to achieve an adult-like configuration by the normal time of birth. Specifically, connectivity was strongest between homolog regions, followed by connectivity between adjacent regions (different limbs but same hemisphere) already in the preterm brain, and increased with age. These changes were specific to the sensorimotor network. Crucially, these trajectories were strongly dependent on age more than age of birth. This demonstrates that during the perinatal period the sensorimotor cortex undergoes preprogrammed changes determining the functional movement organization that are not altered by preterm birth in absence of brain injury

Application of the Fisher-Rao metric to ellipse detection

The parameter space for the ellipses in a two dimensional image is a five dimensional manifold, where each point of the manifold corresponds to an ellipse in the image. The parameter space becomes a Riemannian manifold under a Fisher-Rao metric, which is derived from a Gaussian model for the blurring of ellipses in the image. Two points in the parameter space are close together under the Fisher-Rao metric if the corresponding ellipses are close together in the image. The Fisher-Rao metric is accurately approximated by a simpler metric under the assumption that the blurring is small compared with the sizes of the ellipses under consideration. It is shown that the parameter space for the ellipses in the image has a finite volume under the approximation to the Fisher-Rao metric. As a consequence the parameter space can be replaced, for the purpose of ellipse detection, by a finite set of points sampled from it. An efficient algorithm for sampling the parameter space is described. The algorithm uses the fact that the approximating metric is flat, and therefore locally Euclidean, on each three dimensional family of ellipses with a fixed orientation and a fixed eccentricity. Once the sample points have been obtained, ellipses are detected in a given image by checking each sample point in turn to see if the corresponding ellipse is supported by the nearby image pixel values. The resulting algorithm for ellipse detection is implemented. A multiresolution version of the algorithm is also implemented. The experimental results suggest that ellipses can be reliably detected in a given low resolution image and that the number of false detections can be reduced using the multiresolution algorithm

Development of Single-station Early Warning Lightning Alarm System

Lightning is one of the spectacular natural phenomena which happen on the earth. More than 2000 people are killed worldwide by lightning each year. The lightning monitoring system is important as the early warning alarm system. In this paper,lightning warning alarm system which can monitor and observe the lightning activity has been discussed. The system able to trigger the warning alarm whenever a lightning strikes at a particular area in 10 km radius from UMP Pekan, Pahang, Malaysia. The LabVIEW software was used as a data logger to measure, analyze and calculate the lightning distance. The accuracy of the system has been compared and validated by the Pekan Lightning Detection System (PLDS)