A smartphone-based virtual white cane

The objective of our research was to develop assistive technology for visually impaired people, with a high appreciation for the human potential to achieve, to learn, and to achieve goals. In this document, we describe a virtual white cane made of a combination of a Smartphone and a laser pointer. In our device, the laser pointer beam reflection is captured by the Smartphone camera. The distance from the virtual white cane to the reflection is computed through active triangulation. Then, a personalized vibration, the magnitude of which corresponds to distance, is generated in the Smartphone. In this way, the users receive information that could prevent collisions with obstacles in the environment. Our contributions include the development of a virtual white cane around a Smartphone and other off-the-shelf accessories and a methodology to provide personalized vibratory feedback to the user. Our experiments show that to navigate, our instrument is better option, in terms of travel time, that the use of the hands. However, the travel time is still better using a traditional white cane than our instrument.     

A recurrent missense mutation in the KAL gene in patients with X-linked Kallmann's syndrome

Kallmann's syndrome (KS) is defined by the association of hypogonadotropic hypogonadism and anosmia or hyposmia. Segregation analysis in familial cases has demonstrated diverse inheritance patterns, suggesting the existence of several genes regulating GnRH secretion. Genetic defects have been demonstrated in the KAL gene, located on the Xp22.3 region, explaining the X-linked form of the disease. We report molecular findings regarding the KAL gene in 12 unrelated males with X-linked KS. PCR of the 14 exons of the KAL gene was performed on genomic DNA. PCR products of all exons were purified and sequenced. Genetic defects in the KAL gene were found in 7 patients. One exhibits a deletion from exon 3 to exon 5. Six individuals present a previously unidentified missense mutation in exon 11, consisting of a G to A substitution at codon 514 (GAA to AAA). In the remaining 5 individuals, no mutations were observed. We also found three different polymorphic changes. The first one, in exon 2, had not been reported previously. The other two were located at exons 11 and 12. The deletion described, comprises only part (exon 5) of the coding region of the first fibronectin type III-like repeat of the KAL protein. The rest of the deletion comprises part of the conserved cysteine-rich N-terminal region that corresponds to the whey acidic protein motif. The same missense mutation was found in 6 of the 12 patients, indicating the possibility that it derived from a common ancestor or suggesting the presence of a hot spot in this region of the gene.     

Letter Fibre-as-phase-object approximation in light scattering experiments

Abstract

The use of an optical fibre scattering pattern for measurements of its refractive-index profile and diameter through the fibre-as-phase-object method is discussed. The exact solution from electromagnetic theory and the phase-object approximation are compared. A great discrepancy between the exact solution and the fibre-as-phase-object approximation used in recently published papers is demonstrated and is critically analysed.     

Detectability Conditions of Full Opens in the Interconnections

Opens in interconnection paths disconnect the driven gate(s) from the driving gate. Detectability conditions to test full opens in interconnections are investigated. It has been found that the detectability of this defect depends strongly on the signals at the driving gate and coupling lines. Three possible situations are analyzed. The first is when there is full controllability of both the signal driving the open and the signal(s) at the coupling line(s). Then, the cases of partial and low controllability of the signals are analyzed. Conditions for reliable detection of this defect by logic and I_DDQ testing have been determined. In addition, it has been found that the detectability of interconnection opens depends on the metal level where the signals are laid-out. Routing design for testability techniques are recommended for some interconnection opens non detectable by either a stuck-at based or I_DDQ testing. Experimental data on intentionally designed defective circuit is presented.     

Modeling temperature gradients in wine fermentation tanks

Extreme temperatures are common in large wine fermentation tanks. If not controlled properly, they can lead to problematic fermentations. Thus, efficient cooling and automatic control systems must be designed. However, it is rather difficult to design and implement effective cooling and control systems without adequate models able to reproduce the complex dynamic behavior observed in large fermentors. Therefore, we developed a compartmental dynamic mass-and-energy-balance model able to simulate temperature and concentration gradients in large wine fermentation tanks. This paper presents the model, along with all its parameters. It discusses simulations of temperature, alcohol content, density, biomass, and sugar concentrations. Finally, it presents a sensitivity analysis of the must temperature dynamics. The model reproduced reasonably well the values of the observed variables, including the most critical one: must temperature (with an absolute mean error of 1.4 °C). After proper calibration, it can be used to design control strategies for cooling in large wine fermentation tanks. Our research efforts will be directed in designing such control strategies.     

Lesions in the reproductive tract of boars experimentally infected with porcine rubulavirus

"Blue eye" disease of pigs in Mexico is caused by porcine rubulavirus and characterized by infertility in sows and boars, nervous signs in young pigs, and corneal opacity in pigs of all ages. The pathogenesis of reproductive tract lesions in rubulavirus-infected boars has not previously been investigated. In a first experiment, four 9-month-old boars were inoculated with porcine rubulavirus and killed 5, 15, 30 or 45 days post-inoculation (pi). In a second experiment, four similar boars were inoculated with the same virus and two animals were killed on each of days 70 and 80 pi. Swelling of the head of the epididymis developed in all inoculated boars at approximately day 15 pi. Reduced spermatozoan motility and concentration were detected in semen samples collected from one boar from day 21 pi. At post-mortem examination, nodules were seen in the head of the epididymis of the boars killed 15, 30 or 45 days pi and the right testis of the pig killed 30 days pi was atrophic. Corresponding histopathological epididymal alterations included formation of spermatic granulomas and vacuolar degeneration of ductular epithelium. These lesions were associated with mononuclear cell infiltration and interstitial fibroplasia. Degeneration of seminiferous tubules and interstitial mononuclear cell infiltration were seen in the atrophic testis of the pig killed 30 days pi. There was fibrosis of the head of the epididymis in all boars killed 70 or 80 days pi and one of these animals also had right testicular atrophy associated with degeneration of seminiferous tubules, lymphocytic infiltration and giant cell formation. Porcine rubulavirus antigen was detected by immunofluorescence labelling in the head of the epididymis of the pigs killed 15, 30 or 45 days pi and in one animal killed on day 70 pi. These results indicate that porcine rubulavirus can cause severe epididymo-orchitis and reduced semen quality in sexually mature boars.     

1 W single-transverse-mode Yb-doped double-clad fibre laser at 978nm

A novel all-glass Yb-doped double-clad fibre laser that emits over 1 W of single-transverse-mode output at 978 nm is described. This device is efficiently pumped with 2.5 W of launched power from a single 200 μm broad-area laser diode at 915 nm     

Isolation of the receptor for Amaranthus leucocarpus lectin from murine peritoneal macrophages

This report describes five cases of osteofibrous dysplasia-like adamantinoma of the tibia in young patients ranging from ages 4 1/2 to 14 years. Radiologically and histologically, these cases were indistinguishable from osteofibrous dysplasia of bone, and no epithelial cells were recognized on routine staining. However, epithelial differentiation was seen in the form of scattered keratin-positive cells in all five cases, and tonofilaments in four cases. The patients were treated by curettage, and three had recurrences. Follow-up showed no progression to classic adamantinoma. Osteofibrous dysplasia-like adamantinoma is a special histological type of adamantinoma that affects children and adolescents. It differs from classic adamantinoma in that it lacks conspicuous nests and masses of epithelial cells, and the prognosis after conservative treatment is generally good. Recent publications suggest that osteofibrous dysplasia-like adamantinoma is a precursor of classic adamantinoma. In a comparative study of three cases of classic adamantinoma, we found, in the fibroblastic stroma of the tumors, spindle epithelial cells that were indistinguishable from the epithelial cells of osteofibrous dysplasia-like adamantinoma. This finding suggests that there is an overlap between these conditions. Four additional cases of osteofibrous dysplasia of the tibia from our files lacked epithelial differentiation. It is most likely that osteofibrous dysplasia is part of the morphologic spectrum of adamantinoma.     

Design of a device for pumping a double-clad fiber laser with a laser-diode bar

Pumping rare-earth-doped double-clad fiber lasers with GaAlAs laser-diode bars typically requires one to transform a 1-cm-long one-dimensional linear array of tens of multimode laser-diode sources into atwo-dimensional oblong cross section that approximately matches the fiber's first cladding shape. I describe the design of a device, henceforth called a high-brightness geometric transformer, that uses a cylindrical microlens to image the laser-diode bar near field onto a linear array of soft-glass, thin-clad, rectangular fibers. In turn, the fibers output ends are arranged to form a stack that matches the required first cladding shape. For a typical laser-diode bar with a brightness of 25 mW·μm(-2)·sr(-1), the geometric transformer output brightness is 0.6 mW·μm(-2)·sr(-1), i.e., there is a 40× intermediate loss of brightness. If the output of the geometric transformer is used to pump a Nd-doped double-clad fiber laser, anoverall brightness gain of 340× can be achieved.     

La2O3-Al2O3-SiO2 Glasses for High-Power, Yb3+-Doped, 980-nm Fiber Lasers

Single-mode semiconductor pumps have failed to keep pace with the increasing power requirements of Er-doped fiber amplifiers (EDFAs), so there is a need for high-powered 980-nm sources. Yb³⁺-doped tapered fiber lasers can provide high-power output by conversion of a low-brightness, high-powered, 920-nm, multimode broad stripe laser diode to a high-brightness, 980-nm, single-mode output. The tapered fiber laser requires a fiber with high numerical aperture (NA) (>0.4), a rectangular core, and good Yb³⁺ spectroscopy for efficient operation. CVD-based fiber fabrication methods are incapable of delivering fibers with an NA > ∼0.3 or with good efficiency at 980 nm so a new method of high-NA fiber fabrication was developed. The core glass composition is critical for maintaining a high-NA fiber with good power extraction while avoiding phase separation, loss, and clustering. The SiO₂ level controlled the NA and interdiffusion between core and clad, while the Al₂O₃/La₂O₃ ratio controlled phase separation. A La₂O₃-Al₂O₃-SiO₂ glass was developed that is compatible with a pure SiO₂ cladding glass and has a laser slope efficiency of 70% at 980 nm. The optimized fiber composition yielded 450 mW of 980-nm power in a single-mode fiber.