The purpose of this study was to investigate the presentation and outcome of anorexia nervosa (AN) within the pediatric population. A retrospective chart review of individuals who were admitted for the first time to hospital between 2000-2005 for treatment of AN was completed. Individuals were classified as Early Pediatric AN (admitted <14 years old) or Later Pediatric AN (≥14 years old). It was hypothesized that the Early Pediatric AN group would have a less severe presentation, as measured by percent ideal body weight (%IBW) and medical stability at admission, and better outcome as measured by rate of weight gain post-discharge, number of hospitalizations and the Morgan-Russell General Outcome Scale rating. The study contained a total of 207 cases, larger than many previous studies in pediatric AN. The study found that younger age at presentation was associated with admission at a higher %IBW but not medical stability. Age at presentation did not predict rate of weight gain or rehospitalization; however, the Early Pediatric AN group had a better outcome on the Morgan-Russell scale.

Voice onset time (VOT) är en akustisk tidsparameter som återspeglar den talmotoriska samordningen. VOT betraktas även vara det mest tillförlitliga sättet att särskilja mellan tonande och tonlösa klusiler. VOT hos barn har tidigare studerats i logopediuppsatser vid Linköpings universitet (Lundeborg et al., 2012; Larsson &amp; Wiman, 2011). I dessa arbeten har dock inga upprepade mätningar gjorts, varför det föreligger behov att fastställa hur konsistent barns VOT är. Denna studie syftar till att undersöka hur konsistent klusilproduktionen är hos svenska barn i femårsåldern, samt utreda förekomsten av eventuella könskillnader. I studien medverkade 31 barn, 13 flickor och 18 pojkar där medelåldern var 5:6 år. Barnen fick benämna bilder av minimala par med klusilord tre gånger. Samtliga testningar ljudinspelades. Inspelningarna analyserades därefter. Resultaten visade att barnen var förhållandevis konsekventa i VOT-värden vid de flesta klusilproduktionerna, variabilitet förekom mellan specifika klusilproduktionsomgångar. Bland de barn som hade förton vid produktionen av tonande klusiler noterades variabilitet i såväl förekomst som värde. Inga statistiskt signifikanta könsskillnader noterades.

The primary purpose of this investigation was to experimentally determine the effect of operational parameters on the onset of flow instability (OFI) in narrow, uniformly heated, vertical, rectangular channels. The geometry investigated was a 9.0 cm long rectangular channel with a 1.0mm by 1.3cm cross section. This geometry closely matches the coolant channel geometry in an accelerator target. Nitrogen-saturated subcooled water was used as the coolant, with mass fluxes ranging from 250 to 1336 kg/m^2 s, and an inlet temperature of 26ºC for the OFI experiments. The exit pressures investigated ranged from 275kPa to 620kPa, while the heat flux ranged from 0.729 to 2.236 MW/m^2. The primary data collected from these experiments were used to develop two correlations for the heat flux and mass flux at OFI. Wall temperature data were also collected in order to develop a Nusselt number correlation for the single-phase regime. This correlation is valid for the Reynolds number range of 6x103 to 1.7x104. The data obtained in this investigation will aid designers of high-power-density systems establish design limits to prevent over heating and possible damage due to the onset of flow instability. The data obtained in this investigation will aid designers of high-power-density systems establish design limits to prevent over heating and possible damage due to the onset of flow instability.

The leaner mouse carries an autosomal recessive mutation in the α1A subunit of neuronal P/Q-type voltage gated calcium ion channels. Due to this mutation, the leaner mouse exhibits severe ataxia, absence seizures and paroxysmal dyskinesia. Mutations in this same gene in humans cause: episodic ataxia type 2, familial hemiplegic migraine, spinocerebellar ataxia type 6 and probably the newly recognized form of human inherited epilepsy. Decreased amplitude of calcium current in cerebellar Purkinje cells and decreased calcium buffering capacity suggest that failure of calcium homeostasis may lead to the neurodegeneration observed in these mutant mice. Both sexes are affected. Despite their neurological dysfunction, homozygous leaner mice are able to breed and produce viable offspring. The survival rate for these pups is highly correlated with early fostering to normal lactating dams. This thesis studies the reproductive dysfunction observed in female homozygous leaner mice and is divided into four parts: onset of puberty, estrous cycle, pregnancy and litter assessment, and hormone levels. We have discovered that the onset of puberty is precocious in leaner females compared to age-matched wild type females, and leaner mice spend more time in estrous than age-matched wild type females. Also, we have observed that leaner mice became pregnant less readily than wild type mice, but once pregnant, female leaner mice produced more pups per litter compared with wild type mice. The number of corpora lutea observed in leaner mice is greater than in wild type mice. In leaner mice, the number of corpora lutea in the ovary corresponding to the uterine horn with the highest number of offspring is larger than the number of corpora lutea found in the ovary corresponding to the other uterine horn. Radioimmunoassays of estradiol hormone levels at postnatal day 28 shows higher levels in leaner compared to age-matched wild type mice. However, at postnatal day 28, the luteinizing hormone levels are similar in both categories of mice. This study of reproductive dysfunction in leaner mice was performed to gain further understanding about the role of intracellular calcium ion signaling in neuronal regulation of reproductive processes in females.

Conduct problems are among the most prevalent psychiatric conditions identified in outpatient mental health centers (Frick 1998b; Kazdin, 1995; Loeber, Burke, Lahey, Waters, & Zera, 2000). Despite a long history of examining risk factors associated with conduct problems, many studies have focused exclusively on adolescent onset conduct problems and few studies have sought to examine relationships among risk factors across several domains. Furthermore, few studies have been conducted to examine protective factors thought to mitigate the risk for children who are thought to be at a high risk of manifesting conduct problems. By gaining an understanding of risk and protective factors associated with early onset conduct problems, clinicians can develop and appropriately target interventions to those children at a high risk of developing conduct problems as well as those who are already displaying symptoms associated with early onset conduct problems. The purpose of the present study was to identify factors associated with an increased risk of early onset conduct problems across several domains and to develop a statistical model describing the relationships among these latter domains and risk factors. Furthermore, the present research used these identified risk factors in order to study factors that may offer protective benefits to children who are at a high risk of developing conduct problems at a younger age. The data used in the present study were from the National Survey of Children's Health database which contained data collected in 2007. These data were analyzed using a confirmatory factor analysis approach and multi-group structural equation modeling techniques. The results showed that living in a poorer quality neighborhood, coming from a lower socioeconomic status, and having a mother who reported overall fair or poorer mental health were all risk factors associated with reported early onset conduct problems. Protective factors identified included having a higher quality parent-child relationship and not having a history of involvement in special education. The implications of these findings are discussed as are future directions for research.

Precipitation (P) and precipitable water (W) are important components of the hydrological cycles in the earth system, and their seasonal cycles are closely related to monsoon circulations over monsoon regions. Through theoretical analyses and extensive analysis of data from in-situ measurements, satellite remote sensing, and regional reanalysis, significant progress has been made (via four peer-reviewed publications) in four areas related to P, W, and monsoon onset and retreat. First, based on the normalized W index, a novel unified method is proposed to determine global monsoon onset and retreat dates. The results are consistent with those obtained from different local criteria. Second, theoretical and data analyses demonstrate that, because of the large annual range of temperature, W can increase from winter to summer anywhere except in the tropics, including both monsoon and nonmonsoon regions. Third, while the seasonal variation of P is, in general, caused by complex processes (e.g., atmospheric circulations), thermodynamic derivations and data analysis demonstrate that the variation of P from winter to summer can be easily understood from the comparative strength between the change of water vapor and the change of temperature. In monsoon regions, the change of water vapor from winter to summer is much greater than the change of temperature, so P has an in-phase relation with W. While in some of the nonmonsoon regions, where winter is the rainy season, the change of temperature is much greater than the change of water vapor, leading to an out-of-phase relation between P and W, and, relative to summer, the coldness of the winter air is much more significant than its dryness. Finally, the satisfactory performance of the globally unified monsoon index can be understood by comparing the seasonal cycles of P and W. The significant positive correlations between P and W at seasonal and synoptic scales imply that W has the ability to indicate both the means and the interannual variations of the monsoon onset and retreat. Since large increase of W from winter to summer can occur in both monsoon and nonmonsoon regions, the global monsoon regions cannot be obtained from the seasonal change of W.

To provide technical support for sand control decision-making, it is necessary to predict the production condition at which sand production occurs. Sanding onset prediction involves simulating the stress state on the surface of an oil/gas producing cavity (e.g. borehole, perforation tunnel) and applying appropriate sand production criterion to predict the fluid pressure or pressure gradient at which sand production occurs. In this work, we present numerical and analytical poroelastoplastic stress models describing stress around producing cavity and verify those models against each other. Using those models, we evaluate the stress state on the cavity surface and derive sanding onset prediction models in terms of fluid pressure or pressure gradient based on the given sand production criterion. We then run field case studies and validate the sanding onset prediction models. Rock strength criterion plays important roles in sanding onset prediction. We investigate how the sanding onset prediction results vary with the selection of one or another rock strength criterion. In this work, we present four commonly used rock strength criteria in sanding onset prediction and wellbore stability studies: Mohr-Coulomb, Hoek-Brown, Drucker-Prager, and Modified Lade criteria. In each of the criterion, there are two or more parameters involved. In the literature, a two-step procedure is applied to determine the parameters in the rock strength criterion. First, the Mohr-Coulomb parameters like cohesion So and internal friction angle ff are regressed from the laboratory test data. Then, the parameters in other criteria are calculated using the regressed Mohr-Coulomb parameters. We propose that the best way to evaluate the parameters in a specific rock strength criterion is to perform direct regression of the laboratory test data using that criterion. Using this methodology, we demonstrate that the effect of various rock strength criteria on sanding onset prediction is less dramatic than using the commonly used method. With this methodology, the uncertainties of the effect of rock strength criterion on sanding onset prediction are also reduced.

The allylic bromide functionality within brominated poly(isobutylene-co-isoprene), or BIIR, alkylates primary amines repeatedly to generate thermoset products at reaction rates that are too fast to support commercial rubber processing operations. The objective of this work was to assess the utility of latent N-nucleophiles as curatives and modification reagents for BIIR. Ideally, BIIR formulations containing these latent amines would not cure at standard compound mixing temperatures, but support high crosslinking rates and yields upon heating to conventional vulcanization temperatures. Carbon dioxide-derived salts of ammonia, including (NH4)2CO3, (NH4)HCO3 and (NH4)H2NCO2, can be mixed with BIIR without incurring crosslinking at temperatures below 100oC, but they generate adequate crosslink yields upon heating to 160oC. The corresponding CO2-derived salts of primary amines decompose below 100oC and, therefore, do not provide adequate scorch protection when mixed with BIIR. Latency was conferred on primary amines using imine derivatives, in particular N-alkylbenzaldimine and its substituted analogues. These latent curatives are activated by hydrolysis, thereby providing a means of controlling active nucleophile concentrations, and minimizing crosslinking activity at 100oC without impacting negatively on cure rates at 160oC. The scorch problems generated by primary amines extend to BIIR cure formulations employing conventional sulfur and ZnO curatives. In contrast, imine analogues are shown to provide low temperature scorch stability without impacting negatively on high temperature cure rates and extents. / Thesis (Master, Chemical Engineering) -- Queen's University, 2010-02-01 15:18:16.004

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