Assessment of Audio Interfaces for use in Smartphone Based Spatial Learning Systems for the Blind

Recent advancements in the field of indoor positioning and mobile computing promise development of smart phone based indoor navigation systems. Currently, the preliminary implementations of such systems only use visual interfaces—meaning that they are inaccessible to blind and low vision users. According to the World Health Organization, about 39 million people in the world are blind. This necessitates the need for development and evaluation of non-visual interfaces for indoor navigation systems that support safe and efficient spatial learning and navigation behavior. This thesis research has empirically evaluated several different approaches through which spatial information about the environment can be conveyed through audio. In the first experiment, blindfolded participants standing at an origin in a lab learned the distance and azimuth of target objects that were specified by four audio modes. The first three modes were perceptual interfaces and did not require cognitive mediation on the part of the user. The fourth mode was a non-perceptual mode where object descriptions were given via spatial language using clockface angles. After learning the targets through the four modes, the participants spatially updated the position of the targets and localized them by walking to each of them from two indirect waypoints. The results also indicate hand motion triggered mode to be better than the head motion triggered mode and comparable to auditory snapshot. In the second experiment, blindfolded participants learned target object arrays with two spatial audio modes and a visual mode. In the first mode, head tracking was enabled, whereas in the second mode hand tracking was enabled. In the third mode, serving as a control, the participants were allowed to learn the targets visually. We again compared spatial updating performance with these modes and found no significant performance differences between modes. These results indicate that we can develop 3D audio interfaces on sensor rich off the shelf smartphone devices, without the need of expensive head tracking hardware. Finally, a third study, evaluated room layout learning performance by blindfolded participants with an android smartphone. Three perceptual and one non-perceptual mode were tested for cognitive map development. As expected the perceptual interfaces performed significantly better than the non-perceptual language based mode in an allocentric pointing judgment and in overall subjective rating. In sum, the perceptual interfaces led to better spatial learning performance and higher user ratings. Also there is no significant difference in a cognitive map developed through spatial audio based on tracking user’s head or hand. These results have important implications as they support development of accessible perceptually driven interfaces for smartphones

Scalable arrays of micro-Penning traps for quantum computing and simulation

We propose the use of 2-dimensional Penning trap arrays as a scalable platform for quantum simulation and quantum computing with trapped atomic ions. This approach involves placing arrays of micro-structured electrodes defining static electric quadrupole sites in a magnetic field, with single ions trapped at each site and coupled to neighbors via the Coulomb interaction. We solve for the normal modes of ion motion in such arrays, and derive a generalized multi-ion invariance theorem for stable motion even in the presence of trap imperfections. We use these techniques to investigate the feasibility of quantum simulation and quantum computation in fixed ion lattices. In homogeneous arrays, we show that sufficiently dense arrays are achievable, with axial, magnetron and cyclotron motions exhibiting inter-ion dipolar coupling with rates significantly higher than expected decoherence. With the addition of laser fields these can realize tunable-range interacting spin Hamiltonians. We also show how local control of potentials allows isolation of small numbers of ions in a fixed array and can be used to implement high fidelity gates. The use of static trapping fields means that our approach is not limited by power requirements as system size increases, removing a major challenge for scaling which is present in standard radio-frequency traps. Thus the architecture and methods provided here appear to open a path for trapped-ion quantum computing to reach fault-tolerant scale devices.Comment: 21 pages, 10 figures Changes include adding section IX (Implementation Example) and substantially rewriting section X (Scaling

Performance of durable press finish on cotton with modified DMDHEU, citric acid, BTCA and maleic acid

Cotton fabrics possess the inherent property to form wrinkles under stress. To overcome this problem, conventionally, elective cross-linking agents are applied via the pad-dry-cure method at a high curing temperature. Research carried out in this fi eld has identifed invariable deterioration in the mechanical properties of a fi nished cotton fabric. In this study, four different cross-linking agents, i.e. modified dimethylol dihydroxy ethylene urea (DMDHEU), citric acid, 1,2,3,4 butanetetracarboxylic acid (BTCA) and maleic acid, were applied on a cotton fabric through a selection of combinations, using the Box-Behnken experimental design. It was established that DMDHEU shows the best improvement in the crease recovery angle along with the highest durable press (DP) rating with a poor retention of strength. The citric acid shows the average strength retention as well as an acceptable improvement in crease recovery. BTCA shows the best strength retention, but the poorest crease recovery. The maleic acid also shows an average strength retention with a crease recovery superior to that with BTCA

Authentication System Using Text Passwords Along With Persuasive Cued Click Points

This paper presents an implementation of a two level authentication using a combination of text passwords and persuasive cued click points on three or five images. The most common method for authentication is textual passwords. Though textual passwords are easy to remember, they are vulnerable to eavesdropping, dictionary attacks, social engineering and shoulder surfing. Graphical passwords have been introduced as an alternative to textual passwords. But same as textual passwords, shoulder surfing attacks make most of the graphical schemes vulnerable. To address this problem, textual passwords can be combined with graphical schemes in what gives a two level security without the use of additional hardware. This paper also presents an evaluation of the text based passwords and graphical password schemes which have been tested previously but failed, including usability and security evaluations

TGFβ Drives Metabolic Perturbations during Epithelial Mesenchymal Transition in Pancreatic Cancer: TGFβ Induced EMT in PDAC

TGF beta; Pancreatic cancer; Tumor microenvironmentTGF beta; Cancer de pancreas; Microambiente tumoralTGF beta; Càncer de pàncrees; Microambient tumoralPancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy wherein a majority of patients present metastatic disease at diagnosis. Although the role of epithelial to mesenchymal transition (EMT), mediated by transforming growth factor beta (TGFβ), in imparting an aggressive phenotype to PDAC is well documented, the underlying biochemical pathway perturbations driving this behaviour have not been elucidated. We used high-resolution mass spectrometry (HRMS) based molecular phenotyping approach in order to delineate metabolic changes concomitant to TGFβ-induced EMT in pancreatic cancer cells. Strikingly, we observed robust changes in amino acid and energy metabolism that may contribute to tumor invasion and metastasis. Somewhat unexpectedly, TGFβ treatment resulted in an increase in intracellular levels of retinoic acid (RA) that in turn resulted in increased levels of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (COL1). These findings were further validated in plasma samples obtained from patients with resectable pancreatic cancer. Taken together, these observations provide novel insights into small molecule dysregulation that triggers a molecular cascade resulting in increased EMT-like changes in pancreatic cancer cells, a paradigm that can be potentially targeted for better clinical outcomes.This study was supported by American Cancer Society (IRG-92-152-17 award number AWD4470404), Georgetown Lombardi Comprehensive Cancer Center Support Grant Developmental Funds and Ruesch Foundation to K.U. and A.K.C

Unit cell of a Penning micro-trap quantum processor

Trapped ions in radio-frequency traps are among the leading approaches for realizing quantum computers, due to high-fidelity quantum gates and long coherence times. However, the use of radio-frequencies presents a number of challenges to scaling, including requiring compatibility of chips with high voltages, managing power dissipation and restricting transport and placement of ions. By replacing the radio-frequency field with a 3 T magnetic field, we here realize a micro-fabricated Penning ion trap which removes these restrictions. We demonstrate full quantum control of an ion in this setting, as well as the ability to transport the ion arbitrarily in the trapping plane above the chip. This unique feature of the Penning micro-trap approach opens up a modification of the Quantum CCD architecture with improved connectivity and flexibility, facilitating the realization of large-scale trapped-ion quantum computing, quantum simulation and quantum sensing

Multimodal imaging of torpedo-shaped fundus lesions: New insights

The purpose of this case series is to describe the varied presentation of Torpedo lesions of the fundus and multimodal imaging features in three eyes of three patients. Two patients presented with typical topography, i.e., temporal to the fovea. One patient revealed lesion inferonasal to disc with the head pointing toward the disc. All three patients had an attenuation of outer retinal layers on optical coherence tomography. One patient showed an additional large subretinal cleft. Variable hypoautofluorescence in the area of the torpedo was noted. To conclude torpedo lesions can present at atypical locations, have both retinal and choroidal atrophy and head point toward the optic disc