VictorJuiz/thesis huggingface dataset:
Multimodal access to written communication

Many children and young adults who are severely physically disabled and functionally non-speaking use scanning techniques to control computers. Access to written and face-to-face communication using scanning is frequently far too slow to meet functional requirements. This study investigated whether combining speech recognition with scanning can increase the rate of computer input for these individuals. The study compared two access techniques: traditional scanning and scanning combined with speech recognition. Analysis of the performance of eight children and young adults, who employed scanning as a computer access means, was used to determine the relative input rate and accuracy of the two techniques. A significant increase in items entered per minute was found when comparing access through scanning combined with voice recognition versus access through scanning alone. No significant differences in accuracy were evident.
Formal models of business process reengineering for design and design validation

Improving process design is mostly based on heuristics. Since the underlying principles of heuristics are often ambiguous, the results of their application are unpredictable. To address this problem, we develop three formal models. (1) Analytical model of agent setup time is used to describe the rationale of many heuristics recommending assigning a process to a person/team. (2) Logical model of agent/activity design strategies; a group of agent assignment strategies that can improve agent setup time. (3) Logical model of design validation expertise defines five principles with respect to information flow, case management and agent constraints. The logical models employ generic enterprise knowledge. Defining the meaning of each employed term, they are precise. They are integrated into a software tool that automatically generates alternative agent assignments that achieve minimal process agent setup time and evaluates the process with respect to the principles.
Divided attention and memory, are all secondary tasks the same?

The series of divided attention experiments presented in this paper show that free recall of words from long term memory is neither an automatic nor obligatory process, and is subject to large interference effects from a secondary task performed at retrieval. Experiment 1 employed a running recognition secondary task that involved identifying repeated words within a visually presented list. Words were repeated either shortly after initial presentation (2-3 intervening words) or after a longer delay (10-11 intervening words). When either of these tasks was performed concurrently with retrieval, a substantial decline in oral recall of a primary task word list occurred. Experiment 1a and 1b also showed that demanding participants to make a cognitive and manual response for each item in the secondary task affected the amount of interference produced at retrieval, which supports the response selection/retrieval bottleneck (Carrier and Pashier, 1995) over the parallel retrieval hypothesis (Baddeley et. al., 1984). Using a word-monitoring task, Experiment 2 showed that the need to process verbal material for the secondary task also affects the magnitude of the interference effect. Furthermore, the magnitude of the effect was not influenced by the level of processing required for the secondary task. That is, a word-monitoring task that involved semantic or phonological processing led to a 37% and 33% decline in recall performance respectively. The final experiment showed that word-monitoring tasks performed at the encoding stage of a word list led to a decline of approximately 50% in primary task recall performance. When compared to other published studies, these studies suggest that interference at retrieval is created only when the primary and secondary tasks utilize the same code or underlying representation.
Mode-selective photochemistry of OClO

The near-UV photolysis of OClO at wavelengths near 360 nm gives two chemically distinct channels, ClO + O and Cl + O$\sb2$. We have detected Cl and ClO using (2 + 1) REMPI. The results in this thesis describe the first unambiguous detection of Cl as a product of OClO photolysis and the assignment of the first (2 + 1) REMPI spectrum of OCl using a two-photon excitation from vibrationally excited OCl in the X$(\sp2\Pi)$ state to one of the D$(\sp2\Sigma ),$ E$(\sp2\Sigma ),$ or F$(\sp2\Sigma)$ states. The action spectra for Cl show peak positions identical to the peak positions seen in the absorption spectra of OClO and peak intensities that are similar to the peak intensities of the parent molecule. The action spectra for ClO show peak positions identical to the peak positions seen in the absorption spectra of OClO, but the peak intensities show an enhancement of the peaks associated with the antisymmetric stretching motions of the parent molecule. The differences in the action spectra for the Cl and OCl products indicate that there are two different mechanisms for the formation of the two products. After photolysis of the OClO, we have monitored the kinetics of the Cl atom fragment. The signal shows a time decay corresponding to the loss of the Cl atom by the reaction Cl + OClO $\to$ 2 ClO. No other reaction sequence can be invoked that would give the observed rate of reaction. The Cl atom is made with a quantum yield of 0.15 $\pm$ 0.10 at 360 nm for room temperature OClO. A model determined by K. A. Peterson and H.-J. Werner (J. Chem. Phys. 96, 8948 1992) for the predissociation of OClO in the A$\sp2$A$\sb2$ state to give the ClO + O product channel is:$$\eqalign{&\rm A\sp2A\sb2\ (2\sp2A\sp{\prime\prime}){\to} 1\sp2A\sb1\ (2\sp2A\sp\prime)\ (spin{-}orbit\ coupling)\cr &\rm 1\sp2A\sb1(2\sp2A\sp\prime){\to} 1\sp2B\sb2\ (1\sp2A\sp\prime)\ (vibronic\ coupling\ {\it via\/}\ {\rm asymmetric\ stretch})\cr &\rm 1\sp2B\sb2\ (1\sp2A\sp\prime){\to} ClO + O\ ({\it via}\ {\rm asymmetric\ stretch}).\cr}$$That model has been extended in this thesis to include new observations. There is mode-selective product formation of the ClO product at absorptions associated with the antisymmetric stretching motion of the parent molecule at the (9,0,2) and (8,0,2) peaks. If the antisymmetric stretch were not excited, the vibrational energy in the molecule would redistribute and the antisymmetric stretching mode would have to become excited before the coupling of the $\rm \sp2A\sb1$ state to the $\rm \sp2B\sb2$ state could occur. Variations in the OCl product vibrational distributions suggest that the different regions of the OClO parent molecule absorption spectrum will access different dynamical pathways. At low vibrational energy, if the antisymmetric stretch is not photo-excited, intamolecular vibrational relaxation is required to excite the antisymmetric stretching motion of the OClO parent molecule. (Abstract shortened by UMI.)
Finite element modeling of the frequency characteristics of transformers

The transformer is one of the most difficult power devices to model accurately, especially in the high frequency range. A transformer model which is suitable for simulating high frequency behavior in the Electromagnetic Transients Program (EMTP) is available. This model is based on the frequency characteristics of the transformer terminal admittance matrix over a given range of frequencies. Normally, the terminal admittance matrix is obtained from measurements. However, this procedure is very costly and, in addition, it is not useful to predict the current/voltage profile inside the transformer windings. In order to avoid these disadvantages, in this thesis a finite element method to model the transformer is proposed. This model can be used to obtain the electromagnetic field inside the windings and the circuit parameters such as R, L, C to derive the equivalent circuit network. The terminal admittance matrix is then obtained which can be used by EMTP.
Replication timing of insulin-like growth factor-2 (IFG2) in Beckwith-Wiedemann syndrome

Genomic imprinting results in differential allelic transcription during normal mammalian development. Previously fluorescence in situ hybridization (FISH) demonstrated that imprinted genes exhibit allele-specific asynchronous replication. Beckwith-Wiedemann Syndrome (BWS), an overgrowth syndrome associated with embryonal tumours, frequently exhibits loss of imprinting of the insulin-like growth factor 2 (IGF2) gene. Analysis of IGF2 replication timing in two BWS patients with a chromosomal rearrangement and one with biallelic IGF2 expression was performed to determine whether these genetic changes influence asynchronous replication. Maintenance of the expected pattern of asynchronous replication was retained in cells from a BWS patient with biallelic IGF2 expression, and of the two patients with chromosomal rearrangements at 11p15.5, only one exhibited alterations to replication timing. It is concluded that a chromosomal rearrangement 400kb away from IGF2 may alter the pattern of IGF2 replication, and that this change may be a contributing factor to BWS in this patient.
U-Pb geochronology of the Omai intrusion-hosted Au-quartz vein deposit and host rocks, Guiana Shield, South America

U-Pb geochronology was completed on all main phases of the Omai Au-quartz vein deposit and one sample of the host metavolcanics. Zircon analyses of the metavolcanic define an age of 2120 $\pm$ 2 Ma. Titanite, apatite and feldspar define a Pb-Pb isochron age of 2094 $\pm$ 6 Ma for the crystallization of the intrusion. Zircon analyses from three phases of the intrusion give 2096 $\pm$ 2 Ma, 2092 $\pm$ 11 Ma and 2096 +11/-10 Ma, confirming the magmatic isochron age. Ages from the metavolcanic and intrusion broadly correlate with ages from similar rocks in West Africa. The 26 $\pm$ 2 Ma age difference between the intrusion and metavolcanic age brackets Trans-Amazonian deformation and metamorphism in this area. Titanite and rutile give a Pb-Pb isochron age of 1999 $\pm$ 6 Ma that is believed to reflect a late-stage Trans-Amazonian thermal event, and provides a young age limit on Au mineralization.
Control of Boolean discrete event systems

Based on the supervisory control theory (SCT) of discrete-event systems (DES) established by Ramadge and Wonham, this thesis provides another model, Boolean DES (BDES), to represent a class of structured discrete-event systems and to solve the corresponding supervisory control problems. A BDES is a vector discrete-event system model in which all variables involved are boolean variables, 0 and 1, and the transitions of the system are represented by exclusive-or operations. The introduction of this model can, in some cases, simplify the procedure of modelling and make the representation more natural. The thesis itself falls into three parts. The first part concerns itself with all concepts about modelling. The second part focuses on the derivation of closed-form control law for BDES, with some effort on the computer realization of the control law. The final part devotes itself to the nonblocking problem for the state feedback control theory and specifically for BDES as well.
Accumulation and Metabolism of BMS181321, a Technetium-99m-labelled Nitroimidazole, in Vitro

Hypoxic conditions are believed to be a limitation for the local control of some solid tumours by radiation therapy. However, even for a given tumour type there is great heterogeneity in the extent of hypoxia. A technique to assess the extent of hypoxia in an individual tumour would allow the selection of patients who would most benefit from therapies that target these hypoxic cells. Nitroimidazoles, which are selectively retained in hypoxic cells, have been investigated as hypoxic cell markers. BMS181321, a 2-nitroimidazole labelled with technetium-99m, has offered the possibility of assessing tumour hypoxia using nuclear medicine techniques. Due to the high specific activity of technetium-99m, the concentration of BMS181321 used in its applications is very low. Metabolic depletion of the drug may result in incomplete detection of hypoxic regions in solid tumours. The goal of this work was to investigate the feasibility of using unlabelled nitroaromatics to modify the in vitro accumulation of BMS181321 in hypoxic cells and to assess the potential of using this approach to alter the biodistribution of BMS181321 in its in vivo application. It was found that nitroaromatics of a similar or higher electron affinity than BMS181321 inhibited the hypoxic accumulation of the drug. In contrast, nitroimidazoles of a lower electron affinity than BMS181321 stimulated its accumulation. This thesis addresses the potential clinical relevance of such an approach to modify the hypoxic accumulation of BMS181321, as well as the mechanisms involved in the retention of BMS181321 in hypoxic cells.
Plasticity in the maternal circuit, effects of pup exposure and retention interval on astrocyte numbers in primiparous and multiparous animals

Experience with pups postpartum enhances the expression of maternal behavior up to a month later. These long-term behavioral changes are accompanied by long-term changes in immunohistochemical expression of neuronal and glial proteins, specifically Fos, Protein Kinase C (PKC), and Glial Fibrillary Acidic Protein (GFAP) in the medial preoptic area. The goal of the present study was to examine astrocytic changes (as assessed by Glial Fibrillary Acidic Protein) following varying amounts of maternal experience and over a longer time-frame. Primiparous and multiparous animals (2x pregnant), were given a brief exposure (either 2 or 24 hours) to 1-3 day old rat pups the day following parturition, or were given a similar control manipulation. Animals were then sacrificed and subjected to immunohistochemistry either 1 day, 5 days or 10 days following postpartum pup exposure. A main effect for parity in favor of multiparous animals was seen in the MPOA. An opposite effect for parity was found in the medial and lateral habenula, as well as the medial amygdala (MEA), with primiparous animals having higher numbers of astrocytes than multiparous animals. Parity differences in the MPOA were slight at one day after exposure/manipulation, but were significantly different at day five. At day ten, parity differences were seen, but were dependent upon pup exposure. In contrast, in the MEA and habenula nuclei, parity differences were most substantial at day one. The results suggest that primiparous and multiparous animals differ not only in what they learn, as evidenced from the dissociation between MPOA and MEA/habenula brain regions, but also differ in terms of when learning takes place.
CDMA overlaid cellular systems based on distributed antenna

In this thesis, we propose the CDMA overlaid diversity cellular systems. The proposed systems apply the overlaid cellular structure which partitions the service area into two cell layers: microcells and macrocells. In order to minimize the handoff rate in a mobile communication system, the low-mobility users are assigned to microcells and the high-mobility users are assigned to the larger cells, macrocells. The antenna structures of distributed antenna and sectorized distributed antenna used in the macrocells allows the same frequency spectrum to be shared among the microcells and macrocells which exploits advantage of universal frequency reuse of CDMA. Also, the centralized approach to network configuration allows resource sharing which reduces the hardware cost. The performance of the proposed systems is shown in the simulation where capacity and handoff rate are the parameters used.
Techniques for improved time and data efficiency in Fourier-encoded magnetic resonance imaging

Magnetic resonance imaging is a diagnostic imaging modality in widespread clinical use around the world. White the value of this technology is proven, the availability of the procedure remains low. Part of the problem is due to the relatively long time required to complete a scan. Depending on the resolution and contrast required, MR image data can take up to several minutes to acquire. This thesis addresses the general problem of long scan times in clinical magnetic resonance imaging. The approach taken is to improve aspects of data collection efficiency. In the first part of the thesis, the conventional T2-weighted spin-echo imaging technique is considered. A method of increasing the number of anatomic section locations that may be acquired per unit time is described. The method may be used in conjunction with other methods for reducing scan time, such that the total amount of data collected remains the same. In the second part of the thesis, the technique of dynamic contrast-enhanced magnetic resonance imaging is considered. A strategy for trading spatial resolution to achieve the necessary temporal resolution for dynamic imaging with a spin-echo technique is described. The method is implemented for dynamic imaging of the pituitary gland and evaluated with a clinical study involving 18 patients. The method is further characterized in a retrospective analysis of dynamic contrast-enhanced breast images. In both parts of the thesis, modifications for reduced scan time are demonstrated in a manner which preserves the general image characteristics of the original pulse sequence methodology to which they are applied. Furthermore, the modifications may easily incorporated into clinical practice on standard magnetic resonance imaging hardware.
Dynamic assessment of reading abilities

The effectiveness of dynamic assessment compared to static assessment of reading abilities was investigated in this study. Thirty nine children participated in this study who were reading below the 25th percentile for their chronological age based on the Wide Range Achievement Test 3 (WRAT 3). The participants were students who experienced word recognition difficulties, and ranged from 8 to 11 years of age. They were placed into three groups and were tested in three sessions: a pretest, treatment/assessment, and a posttest session. The main dependent variable was oral reading and the independent variable was dynamic assessment at three levels: a Static control (S); and two Dynamic reading groups (Phonemic Prompt, PP and Phonemic prompt with Contextual Mediation, PPCM). The results showed that at posttest: (a) children in the PPCM group did not produce higher reading scores than children in the PP group, but did score higher than children in the S group; and, (b) children in the PP group scored higher on reading ability than children in the S group. These findings demonstrate that Dynamic Assessment of reading abilities compliments Static Assessment by providing more information about the student's reading profile.
The effect of bone morphogenetic protein-7 on the regeneration of rat periodontium

Periodontal diseases are among the most prevalent diseases of humankind, affecting the integrity and composition of soft and mineralized connective tissues that surround the tooth. Bone morphogenetic proteins (BMPs) are known for their ability to induce new bone formation locally at the site of application. Consequently, we have used BMP-7, incorporated into a collagen vehicle, to assess its effects on healing of wounded rat periodontium in a rat periodontal window wound model at various time points (days 2, 5, 10, 21 & 60). Controls included wounds filled with collagen vehicle alone or unfilled wounds. $\sp3$H-thymidine was given by injection to all animals one hour before sacrifice to permit autoradiographic assessment of cycling cells. Two stage-specific bone markers, osteopontin (OPN) and bone sialoprotein (BSP) were used to evaluate early and late osteogenic differentiation stages, respectively. BMP-7 did not affect the overall % of proliferating cells, but did induce clonal growth of presumptive osteogenic cells as early as day 10. Increased bone formation was evident at day 21 in BMP-7 treated samples and there was a 3-fold increase (p $<$ 0.001) in the width of bone on the buccal side. There was an about 30% increase (p $<$ 0.001) in the expression of OPN and BSP on the outer surface of nascent bone whereas in controls bone formation ceased at day 21. PL width was unchanged in wounded and intact areas, regardless of the treatment. The initial BMP-induced increase in proliferative activity in regenerating bone-related areas returned to basal levels at day 60. BMP appeared to act locally as the tissues far away from the drill site exhibited no increase in proliferation or increased OPN or BSP staining. I conclude that BMP-7 promotes the proliferation and differentiation of putative osteogenic progenitor cells, and induces bone formation, but does not disrupt PL homeostasis.
An experimental study of the effect of impeller designs on the performance of gas inducing contactors

Five impeller designs were tested in a laboratory scale gas inducing contactor (GIC). Testing included induced static head, rate of gas induction, mixing time and mass transfer coefficient. The Reference design for comparisons was the straight blade impeller with shroud. For the designs studied the following results were obtained. The induced static head, rate of gas induction, mixing time and mass transfer coefficient of the down-pumping impeller were enhanced over the reference design. The mass transfer coefficient of the up-pumping impeller was also enhanced. Unlike the other designs this impeller showed instability in the power consumption in the range 1400-1750 RPM. The induced static head and the rate of gas induction of the double row impeller were enhanced, but the mass transfer coefficient was only marginally improved. The straight blade impeller with cut-off was inferior in all respects.
Isotopic applications to contaminant hydrogeology, using [delta]¹³C analysis to investigate the origin and fate of dissolved organic contaminants

To investigate the potential of stable C isotopes to identify the origin and fate of groundwater contaminants, techniques to extract dissolved organic compounds for isotopic analysis are developed and applied. Pentane extraction is shown to be an accurate, reproducible and linear extraction technique for isotopic analysis of dissolved BTEX (benzene, toluene, ethylbenzene and p-, m- and o-xylene) at concentrations from 0.1 to 100ppm. Free product BTEX obtained from three different manufacturers shows distinct isotopic fingerprints, illustrating the potential of C isotopes to delineate different contaminant sources. An investigation into volatilization of organic compounds shows that $\delta\sp{13}$C values are conserved during volatilization and demonstrates that headspace extraction is an accurate and reproducible technique for $\delta\sp{13}$C analysis of dissolved VOC's. Isotopic measurements performed on dissolved BTEX at a contaminated field site show small differences (1-2$\perthous$) in $\delta\sp{13}$C values within the anaerobic plume core that are attributed to small-scale variations in anaerobic activity.