Robust indoor speaker recognition in a network of audio and video sensors

Situational awareness is achieved naturally by the human senses of sight and hearing in combination. Automatic scene understanding aims at replicating this human ability using microphones and cameras in cooperation. In this paper, audio and video signals are fused and integrated at different levels of semantic abstractions. We detect and track a speaker who is relatively unconstrained, i.e., free to move indoors within an area larger than the comparable reported work, which is usually limited to round table meetings. The system is relatively simple: consisting of just 4 microphone pairs and a single camera. Results show that the overall multimodal tracker is more reliable than single modality systems, tolerating large occlusions and cross-talk. System evaluation is performed on both single and multi-modality tracking. The performance improvement given by the audio–video integration and fusion is quantified in terms of tracking precision and accuracy as well as speaker diarisation error rate and precision–recall (recognition). Improvements vs. the closest works are evaluated: 56% sound source localisation computational cost over an audio only system, 8% speaker diarisation error rate over an audio only speaker recognition unit and 36% on the precision–recall metric over an audio–video dominant speaker recognition method.

Regenerative Cues of Myeloid Cells on Pancreatic Epithelium

Thesis (Ph.D.)--University of Washington, 2016-07

Fiber Bragg Gratings Strain Sensors for Railway Applications

Fiber optical sensors have played an important role in applications for monitoring the health of civil infrastructures, such as bridges, oil rigs, and railroads. Due to the reduction in cost of fiber-optic components and systems, fiber optical sensors have been studied extensively for their higher sensitivity, precision and immunity to electrical interference compared to their electrical counterparts. A fiber Bragg grating (FBG) strain sensor has been employed for this study to detect and distinguish normal and lateral loads on rail tracks. A theoretical analysis of the relationship between strain and displacement under vertical and horizontal strains on an aluminum beam has been performed, and the results are in excellent agreement with the measured strain data. Then a single FBG sensor system with erbium-doped fiber amplifier broadband source has been carried out. Force and temperature applied on the system have resulted in changes of 0.05 nm per 50 με and 0.094 nm per 10 oC at the center wavelength of the FBG. Furthermore, a low cost fiber-optic sensor system with a distributed feedback (DFB) laser as the light source has been implemented. We show that it has superior noise and sensitivity performances compared to strain gauge sensors. The design has been extended to accommodate multiple sensors with negligible cross talk. When two cascaded sensors on a rail track section are tested, strain readings of the sensor 20 inches away from the position of applied force decay to one seventh of the data of the sensor at the applied force location. The two FBG sensor systems can detect 1 ton of vertical load with a square wave pattern and 0.1 ton of lateral loads (3 tons and 0.5 ton, respectively, for strain gauges). Moreover, a single FBG sensor has been found capable of detecting and distinguishing lateral and normal strains applied at different frequencies. FBG sensors are promising alternatives to electrical sensors for their high sensitivity,ease of installation, and immunity to electromagnetic interferences.

Dissecting signaling pathways that control glia migration in the developing Drosophila retina

The function of a complex nervous system relies on an intricate interaction between neurons and glial cells. However, as glial cells are generally born distant from the place where they settle, molecular cues are important to direct their migration. Glial cell migration is important in both normal development and disease, thus current research in the laboratory has been focused on dissecting regulatory events underlying that crucial process. With this purpose, the Drosophila eye imaginal disc has been used as a model. In response to neuronal photoreceptor differentiation, glial cells migrate from the CNS into the eye disc where they act to correctly wrap axons. To ensure proper development, attractive and repulsive signals must coordinate glial cell migration. Importantly, one of these signals is Bnl, a Fibroblast Growth Factor (FGF) ligand expressed by retinal progenitor cells that was suggested to act as a non-autonomous negative regulator of excessive glial cell migration (overmigration) by binding and activating the Btl receptor expressed by glial cells. Through the experimental results described in chapter 3 we gained a detailed insight into the function of bnl in eye disc growth, photoreceptor development, and glia migration. Interestingly, we did not find a direct correlation between the defects on the ongoing photoreceptors and the glia overmigration phenotype; however, bnl knockdown caused apoptosis of eye progenitor cells what was strongly correlated with glia migration defects. Glia overmigration due to Bnl down-regulation in eye progenitor cells was rescued by inhibiting the pro-apoptotic genes or caspases activity, as well as, by depleting JNK or Dp53 function in retinal progenitor cells. Thus, we suggest a cross-talk between those developmental signals in the control of glia migration at a distance. Importantly, these results suggest that Bnl does not control glial migration in the eye disc exclusively through its ability to bind and activate its receptor Btl in glial cells. We also discuss possible biological roles for the glia overmigration in the bnl knockdown background. Previous results in the lab showed an interaction between dMyc, a master regulator of tissue growth, and Dpp, a Transforming Growth Factor-β important for retinal patterning and for accurate glia migration into the eye disc. Thus, we became interested in understanding putative relationships between Bnl and dMyc. In chapter 4, we show that they positively cooperate in order to ensure proper development of the eye disc. This work highlights the importance of the FGF signaling in eye disc development and reveals a signaling network where a range of extra- and intra-cellular signals cooperate to non-autonomously control glial cell migration. Therefore, such inter-relations could be important in other Drosophila cellular contexts, as well as in vertebrate tissue development.

Nitric oxide synthase and NAD(P)H oxidase modulate coronary endothelial cell growth

Reactive oxygen species (ROS) including nitric oxide (NO) and superoxide anion (O2-) are associated with cell migration, proliferation and many growth-related diseases. The objective of this study was to determine whether there was a reciprocal relationship between rat coronary microvascular endothelial cell (CMEC) growth and activity/expressions (mRNA and protein) of endothelial NO synthase (eNOS) and NAD(P)H oxidase enzymes. Proliferating namely, 50% confluent CMEC possessed approximately three-fold increased activity and expression of both enzymes compared to 100% confluent cells. Treatment of CMEC with an inhibitor of eNOS (L-NAME, 100M) increased cell proliferation as assessed via three independent methods i.e. cell counting, determination of total cellular protein levels and [3H]thymidine incorporation. Similarly, treatment of CMEC with pyrogallol (0.3-3 mM), a superoxide anion (O2-)- generator, also increased CMEC growth while spermine NONOate (SpNO), a NO donor, significantly reduced cell growth. Co-incubation of CMEC with a cell permeable superoxide dismutase mimetic (Mn-III-tetrakis-4-benzoic acid-porphyrin; MnTBAP) plus either pyrogallol or NO did not alter cell number and DNA synthesis thereby dismissing the involvement of peroxynitrite (OONO-) in CMEC proliferation. Specific inhibitors of NAD(P)H oxidase but not other ROS-generating enzymes including cyclooxygenase and xanthine oxidase, attenuated cell growth. Transfection of CMEC with antisense p22-phox cDNA, a membrane-bound component of NAD(P)H oxidase, resulted in substantial reduction in [3H]thymidine incorporation, total cellular protein levels and expression of p22-phox protein. These data demonstrate a cross-talk between CMEC growth and eNOS and NAD(P)H oxidase enzyme activity and expression, thus suggesting that the regulation of these enzymes may be critical in preventing the initiation and/or progression of coronary atherosclerosis.

Physiological and molecular analysis of the interaction between aluminium toxicity and drought stress in common bean (Phaseolus vulgaris)

Aluminium (Al) toxicity and drought are two major factors limiting common bean (Phaseolus vulgaris) production in the tropics. Short-term effects of Al toxicity and drought stress on root growth in acid, Al-toxic soil were studied, with special emphasis on Al-drought interaction in the root apex. Root elongation was inhibited by both Al and drought. Combined stresses resulted in a more severe inhibition of root elongation than either stress alone. This result was different from the alleviation of Al toxicity by osmotic stress (-0.60 MPa polyethylene glycol) in hydroponics. However, drought reduced the impact of Al on the root tip, as indicated by the reduction of Al-induced callose formation and MATE expression. Combined Al and drought stress enhanced up-regulation of ACCO expression and synthesis of zeatin riboside, reduced drought-enhanced abscisic acid (ABA) concentration, and expression of NCED involved in ABA biosynthesis and the transcription factors bZIP and MYB, thus affecting the regulation of ABA-dependent genes (SUS, PvLEA18, KS-DHN, and LTP) in root tips. The results provide circumstantial evidence that in soil, drought alleviates Al injury, but Al renders the root apex more drought-sensitive, particularly by impacting the gene regulatory network involved in ABA signal transduction and cross-talk with other phytohormones necessary for maintaining root growth under drought.

Simulation tools for the analysis of single electronic systems

Developments in theory and experiment have raised the prospect of an electronic technology based on the discrete nature of electron tunnelling through a potential barrier. This thesis deals with novel design and analysis tools developed to study such systems. Possible devices include those constructed from ultrasmall normal tunnelling junctions. These exhibit charging effects including the Coulomb blockade and correlated electron tunnelling. They allow transistor-like control of the transfer of single carriers, and present the prospect of digital systems operating at the information theoretic limit. As such, they are often referred to as single electronic devices. Single electronic devices exhibit self quantising logic and good structural tolerance. Their speed, immunity to thermal noise, and operating voltage all scale beneficially with junction capacitance. For ultrasmall junctions the possibility of room temperature operation at sub picosecond timescales seems feasible. However, they are sensitive to external charge; whether from trapping-detrapping events, externally gated potentials, or system cross-talk. Quantum effects such as charge macroscopic quantum tunnelling may degrade performance. Finally, any practical system will be complex and spatially extended (amplifying the above problems), and prone to fabrication imperfection. This summarises why new design and analysis tools are required. Simulation tools are developed, concentrating on the basic building blocks of single electronic systems; the tunnelling junction array and gated turnstile device. Three main points are considered: the best method of estimating capacitance values from physical system geometry; the mathematical model which should represent electron tunnelling based on this data; application of this model to the investigation of single electronic systems. (DXN004909)

Corneal Re-epithelialization Stimulated by Diadenosine Polyphosphates Recruits RhoA/ROCK and ERK1/2 Pathways

Purpose. To investigate the role of ERK1/2 and RhoA/ROCK intracellular pathways in the modification of corneal re-epithelialization when stimulated by the diadenosine polyphosphates Ap4A and Ap3A. Methods. In wounded confluent SIRC (Statens Seruminstitut rabbit cornea) cell monolayers and in the presence or absence of Ap4A or Ap3A 100 μM, a battery of P2 receptor antagonists and inhibitors of tyrosin kinases, MAPK, and cytoskeleton pathways (AG1478 100 μM, U0126 100 μM, Y27632 100 nM, and (−)-blebbistatin 10 μM; n = 8 each) were assayed. Also, the activation of ERK1/2 and ROCK-I was examined by Western blot assay after treatment with Ap4A and Ap3A (100 μM), with or without suramin, RB-2, U0126, and Y27632. The intracellular distribution of pERK and ROCK-I was examined in the presence of Ap4A or Ap3A (100 μM) with U0126 and Y27632 (100 nM). Results. In the presence of Ap4A, U0126, Y27632, AG1478, and (−)-blebbistatin, reduced the migration rate compared to the effect of Ap4A alone (P < 0.0001, P < 0.001, P < 0.01, and P < 0.1 versus Ap4A, respectively). In the presence of Ap3A 100 μM, U0126 and Y27632 accelerated the migration rate when compared with the effect of Ap3A alone, whereas AG1478 and (−)-blebbistatin (P < 0.0001 versus Ap3A) slowed the migration rate. Western blot assays demonstrated that both dinucleotides activated the ERK1/2 pathway but only Ap4A activated the ROCK-I pathway. The intracellular distribution of pERK1/2 and ROCK-I reflected cross-talk between these two pathways. Conclusions. The activation of the Ap4A/P2Y2 receptor, accelerates corneal epithelial cell migration during wound healing with the activation of MAPK and cytoskeleton pathways, whereas activation of the Ap3A/P2Y6 receptor signals only the MAPK pathway.

Direct Write Fabrication of Waveguides and Interconnects for Optical Printed Wiring Boards

Current copper based circuit technology is becoming a limiting factor in high speed data transfer applications as processors are improving at a faster rate than are developments to increase on board data transfer. One solution is to utilize optical waveguide technology to overcome these bandwidth and loss restrictions. The use of this technology virtually eliminates the heat and cross-talk loss seen in copper circuitry, while also operating at a higher bandwidth. Transitioning current fabrication techniques from small scale laboratory environments to large scale manufacturing presents significant challenges. Optical-to-electrical connections and out-of-plane coupling are significant hurdles in the advancement of optical interconnects. The main goals of this research are the development of direct write material deposition and patterning tools for the fabrication of waveguide systems on large substrates, and the development of out-of-plane coupler components compatible with standard fiber optic cabling. Combining these elements with standard printed circuit boards allows for the fabrication of fully functional optical-electrical-printed-wiring-boards (OEPWBs). A direct dispense tool was designed, assembled, and characterized for the repeatable dispensing of blanket waveguide layers over a range of thicknesses (25-225 µm), eliminating waste material and affording the ability to utilize large substrates. This tool was used to directly dispense multimode waveguide cores which required no UV definition or development. These cores had circular cross sections and were comparable in optical performance to lithographically fabricated square waveguides. Laser direct writing is a non-contact process that allows for the dynamic UV patterning of waveguide material on large substrates, eliminating the need for high resolution masks. A laser direct write tool was designed, assembled, and characterized for direct write patterning waveguides that were comparable in quality to those produced using standard lithographic practices (0.047 dB/cm loss for laser written waveguides compared to 0.043 dB/cm for lithographic waveguides). Straight waveguides, and waveguide turns were patterned at multimode and single mode sizes, and the process was characterized and documented. Support structures such as angled reflectors and vertical posts were produced, showing the versatility of the laser direct write tool. Commercially available components were implanted into the optical layer for out-of-plane routing of the optical signals. These devices featured spherical lenses on the input and output sides of a total internal reflection (TIR) mirror, as well as alignment pins compatible with standard MT design. Fully functional OEPWBs were fabricated featuring input and output out-of-plane optical signal routing with total optical losses not exceeding 10 dB. These prototypes survived thermal cycling (-40°C to 85°C) and humidity exposure (95±4% humidity), showing minimal degradation in optical performance. Operational failure occurred after environmental aging life testing at 110°C for 216 hours.

tRNA anticodon loop modifications ensure protein homeostasis and cell morphogenesis in yeast

Using budding yeast, we investigated a negative interaction network among genes for tRNA modifications previously implicated in anticodon-codon interaction: 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U34: ELP3, URM1), pseudouridine (Ψ38/39: DEG1) and cyclic N6-threonyl-carbamoyl-adenosine (ct6A37: TCD1). In line with functional cross talk between these modifications, we find that combined removal of either ct6A37 or Ψ38/39 and mcm5U34 or s2U34 results in morphologically altered cells with synthetic growth defects. Phenotypic suppression by tRNA overexpression suggests that these defects are caused by malfunction of tRNALysUUU or tRNAGlnUUG, respectively. Indeed, mRNA translation and synthesis of the Gln-rich prion Rnq1 are severely impaired in the absence of Ψ38/39 and mcm5U34 or s2U34, and this defect can be rescued by overexpression of tRNAGlnUUG. Surprisingly, we find that combined modification defects in the anticodon loops of different tRNAs induce similar cell polarity- and nuclear segregation defects that are accompanied by increased aggregation of cellular proteins. Since conditional expression of an artificial aggregation-prone protein triggered similar cytological aberrancies, protein aggregation is likely responsible for loss of morphogenesis and cytokinesis control in mutants with inappropriate tRNA anticodon loop modifications.

Espiritualidad y política: una propuesta tibetana para la transformación del orden mundial

La Revolución Espiritual promovida por el Dalai Lama plantea una unión entre espiritualidad y política. El proyecto de una ética universal, que se inscribe dentro de dicha Revolución, busca impactar la manera en que las relaciones internacionales se desarrollan, dándole prevalencia a los valores humanos. Sin embargo, esa proposición se encuentra ligada al contexto de exilio en el marco del conflicto sino-tibetano que afecta al continente asiático. Por esto, en la presente monografía, haciendo uso de los conceptos de marco de acción colectiva e identidad inscritos en la corriente de los movimientos sociales en la disciplina de las Relaciones Internacionales, se pretende determinar la relación entre identidad tibetana, marco de acción colectiva y la propuesta de una ética universal. Para ello se recurre, metodológicamente, a textos y a trabajo de campo en Bogotá. Así, se pretende establecer la relación entre espiritualidad y política como propuesta tibetana atravesada por el conflicto sino-tibetano.

Cross-cultural partnerships must talk to build trust

Academic partnerships bring knowledge and drive economic growth, but success depends on good communications that build trust, says Tim Gore.

Let's talk about sex(ism): cross-national perspectives on women partners’ narratives on equality and sexism at work in Germany and the UK

While the accounting academy has contributed in important ways to furthering our understanding of the relative absence of women in top positions in Professional Service Firms, in-depth empirical research that focuses specifically on sexism is rare, especially so from a cross-national perspective. Drawing on sixty interviews with women partners in public accountancy firms in Germany and the United Kingdom, this article examines how women partners talk about sexism and equal opportunities in the accountancy profession and considers how these narratives are patterned cross-nationally. Employing cultural theory, this study explores how elite women discursively relate to sexism and equal opportunities through their career histories and demonstrates the complex interrelation between the context in which these narratives are produced and the past and present positions of the respondents. Interestingly, it was the German respondents who drew on problematic notions of ‘choice’ and responsibility, where it was upon women to make a choice between their careers and home lives, while this decision-making process was not expected from men. This was in contrast to the accounts of the UK participants who, although also unveiling tensions in their talk, were more inclined to acknowledge continuing structural constraints.

Sex Talk: A Multiple Case Study to Explore and Understand Parent-Child Sexual Health Communication in Chinese Immigrant Families

Parent-child sexual health communication can be beneficial. Many factors affect such communication in Chinese immigrant families. This qualitative study explored the influences of acculturation, parenting, and parental participation in the Raising Sexually Healthy Children Program (RSHC) on such communication. With a hermeneutic framework, the purpose was to develop understanding based on the topic, context, and researcher interpretations. Twelve interviews elicited data from six parent-child dyads, three from the RSHC. Analysis involved coding processes; data were compared repeatedly and organized into themes. Perceived personality differences between generations were confounded with cultural communicative differences. Parents used implicitness observed in Chinese culture to establish "open" communication; children expected explicitness observed in Western culture. Post- RSHC, parents perceived themselves as more open to talking about sex; children did not perceive such parental changes. Future research should include joint interviews and longitudinal program evaluation. Future practice should focus on cross-cultural communication and involving children in RSHC.

Talk, thinking and philosophy in the primary classroom.

Lenguaje, pensamiento y filosofía son componentes fundamentales del aprendizaje de los niños. El manual comienza preguntando cómo puede el maestro proporcionar a los niños la oportunidad de desarrollar sus habilidades en estas áreas, por qué se deben enseñar y se examinan los enfoques actuales en este ámbito. Profundiza cómo los profesores pueden desarrollarlos en las seis áreas del aprendizaje para ayudar a los niños a adquirir y profundizar el entendimiento. Ofrece una introducción práctica a una serie de orientaciones para el aula.