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Beyond Conscious Object Perception: Processing and Inhibition of the Groundside of a Figure
No full textObject perception is necessary to our understanding of the visual world, yet its neural mechanism remains poorly understood. The goal of this dissertation is to shed light on this mechanism. Current computational models of object perception suggest that regions on opposite sides of a shared border compete, with the winner perceived as the shaped object and the loser as its locally shapeless background (or ground). Recent behavioral work indicates that the result of this competition is suppression of the ground at the level of object shape--a finding not predicted by models. Here, I present three studies that extend this previous research on ground suppression as a mechanism by which object perception is accomplished. I first show that the amount of suppression applied to the ground depends on the amount of competition for object status (Salvagio, Cacciamani, & Peterson, 2012). I then provide the first neural evidence of ground suppression from shape-level competition at both high and low levels of the visual hierarchy, with the latter arising from top-down feedback (Cacciamani, Scalf, & Peterson, submitted). Finally, I show that semantic information pertaining to the ground is accessed prior to the assignment of object status, but unlike shape information, is not suppressed (Cacciamani, Mojica, Sanguinetti, & Peterson, 2014). Together, the three studies that comprise this dissertation demonstrate that ground suppression arising from shape-level competition underlies object perception. This research contradicts traditional theories stating that objects are processed unidirectionally through the visual system in a single feedforward pass; instead, it supports theories of object perception entailing dynamical feedforward and feedback processes
MEMS-based LC tank with extended tuning range for low phase-noise VCO
No full textThis paper presents the modeling, manufacturing, and testing of a micro-electromechanical system (MEMS)-based LC tank resonator suitable for low phase-noise voltage-controlled oscillators (VCOs). The device is based on a variable MEMS varactor in series with an inductive coplanar waveguide line. Two additional parallel stubs controlled by two ohmic MEMS switches have been introduced in order to increase the resonator tunability. The device was fabricated using the FBK-irst MEMS process on high resistivity (HR) silicon substrate. Samples were manufactured with and without a 0-level quartz cap. The radio frequency characterization of the devices without 0-level cap has shown a continuous tuning range of 11.7% and a quality factor in the range of 33-38. The repeatability was also tested on four samples and the continuous tuning is 11.7 ± 2%. Experimental results on the device with a 0-level cap, show a frequency downshift of about 200 MHz and a degradation of the quality factor of about 20%. This is, most likely, due to the polymeric sealing ring as well as to a contamination of the ohmic contacts introduced by the capping procedure. A preliminary design of a MEMS-based VCO was performed using Advanced Design System and a hardwired prototype was fabricated on Surface Mount Technology on RO4350 laminate. The prototype was tested resulting in a resonance frequency of 5 GHz with a phase noise of -105 and -126 dBc at 100 KHz and 1 MHz, respectively, and a measured output power of -1 dBm. © 2015 Cambridge University Press and the European Microwave Association
Wettability of transparent YAG (Y<inf>3</inf>Al<inf>5</inf>O<inf>12</inf>) by molten Ag-Cu-Ti alloys
No full textMEMS-based LC tank with extended tuning range for low phase-noise VCO
No full textThis paper presents the modeling, manufacturing, and testing of a micro-electromechanical system (MEMS)-based LC tank resonator
suitable for low phase-noise voltage-controlled oscillators (VCOs). The device is based on a variable MEMS varactor in
series with an inductive coplanar waveguide line. Two additional parallel stubs controlled by two ohmic MEMS switches have
been introduced in order to increase the resonator tunability. The device was fabricated using the FBK-irst MEMS process on
high resistivity (HR) silicon substrate. Samples were manufactured with and without a 0-level quartz cap. The radio frequency
characterization of the devices without 0-level cap has shown a continuous tuning range of 11.7% and a quality factor in the
range of 33–38. The repeatability was also tested on four samples and the continuous tuning is 11.7+2%. Experimental
results on the device with a 0-level cap, show a frequency downshift of about 200 MHz and a degradation of the quality factor
of about 20%. This is,most likely, due to the polymeric sealing ring as well as to a contamination of the ohmic contacts introduced
by the capping procedure.Apreliminary design of aMEMS-basedVCOwas performed usingAdvancedDesign Systemand a hardwired
prototype was fabricated on Surface Mount Technology on RO4350 laminate. The prototype was tested resulting in a resonance
frequency of 5 GHz with a phase noise of 2105 and 2126 dBc at 100 KHz and 1 MHz, respectively, and a measured
output power of 21 dBm
Students' acceptance of tablet PCs in Italian high schools: Profiles and differences
No full textThe tablet PC represents a very popular mobile computing device, and together with other technologies it is changing the world of education. This study aimed to explore the acceptance of tablet PC of Italian high school students in order to outline the typical students' profiles and to compare the acceptance conveyed in two types of use (learning and communicative activities at school). Data were collected using an online survey that was filled out by students at home. Two hundred and ninety-six students from six public high schools in Milan and surrounding suburbs voluntarily accepted to participate in the study. The results show a varied situation in the Italian schools despite the availability of and funding for the technology. Three clusters were identified with high, moderate and low acceptance of tablet PC and a comparison between such clusters revealed significant differences in gender, grade level and usage frequency. The groups showed also significant differences in relation to the uses of tablet PC at school that appeared coherent with their level of acceptance: students who have higher level of acceptance are those who use the tool more both for learning and communicative purposes. To conclude, students with lower acceptance probably need to better understand the opportunities offered by this technology and how to use it. Based on examining the data from the survey, preliminary recommendations are made
Factors Affecting Students' Acceptance of Tablet PCs: A Study in Italian High Schools
No full textTo maximize the advantages of the tablet personal computer (TPC) at school, this technology needs to be accepted by students as new tool for learning. With reference to the Technology Acceptance Model and the Unified Theory of Acceptance and Use of Technology, the aims of this study were (a) to analyze factors influencing high school students' acceptance of TPCs and (b) to detect any difference in this influence considering the frequency of TPC use, students' gender, and school grade. Two hundred and ninety-six students from six high schools in the Milan area participated in the study. Data were collected using an online survey. The results showed that empowerment in learning, perceived usefulness, and support conditions affect learning use, and empowerment in learning and affect influence communicative use of TPCs. The implications of these results are discussed. (Keywords: tablets, acceptance, digital technologies, high school, path analysis
ATP independent proteasomal degradation of NQO1 in BL cell lines
No full textHuman NAD(P)H: quinone oxidoreductase 1 (NQO1) catalyzes the obligatory two-electron reduction of quinones. For this peculiar catalytic mechanism, the enzyme is considered an important cytoprotector.
The NQO1 gene is expressed in all human tissues, unless a polymorphism due to C609T point mutation is present. This polymorphism produces a null phenotype in the homozygous condition and reduced enzyme activity in the heterozygous one. We previously demonstrated that two cell lines of haematopoietic
origin, HL60 and Raji cells, possess the same heterozygous genotype, but different phenotypes; as expected for a heterozygous condition the HL60 cell line showed a low level of enzyme activity, while the Raji cell line appeared as null phenotype. The level of NQO1 mRNA was similar in the two cell lines and the different phenotype was not due to additional mutations or to expression of alternative splicing products. Here we show that in Raji BL cell line with heterozygous genotype the null NQO1 phenotype is due to 20S proteasome degradation of wild type and mutant protein isoforms and is not directly linked to
C609T polymorphism. This finding may have important implications in B-cell differentiation, in leukaemia risk evaluation and in chemotherapy based on proteasome inhibitors
BOLD Activation on the Groundside of Figures: More Suppression of Grounds That Competed More for Figural Status
No full textBOLD Activation on the Groundside of Figures: More Suppression of Grounds That Competed More for Figural Status
No full textAcceso a la información pública: un derecho esencial para el funcionamiento de un gobierno republicano
No full textFallo: "Savoia, Claudio Martín c/ EN - Secretaría Legal y Técnica (dto. 1172/03) s/
amparo ley 16.986" - CSJ 315/2013 (49-S) /CS1.DESTACAD
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