Purpose: The purpose of this study was to determine if respiratory and laryngeal function during spontaneous speech production were different for teachers with voice disorders as compared to teachers without voice problems. The basic research questions posed in this study, as assessed during spontaneous speaking were: 1) Do subjects with a voice disorder show differences in lung volume patterns relative to control subjects? 2) Do subjects with a voice disorder show differences in vocal fold approximation as measured by contact quotient and contact index relative to control subjects? 3) Are these between-group differences most pronounced for mock teaching tasks versus a conversational speaking task? 4) Do subjects with a voice disorder rely more on laryngeal versus respiratory-based strategies for increasing loudness level as compared to control subjects?Method: Nine teachers with and nine teachers without voice problems were included in this study. Respiratory function was measured with magnetometry, and laryngeal function was measured with electroglottography. Respiratory and laryngeal function were measured during three spontaneous speaking tasks: a simulated teaching task at a typical and increased loudness level, and a conversational speaking task. Two structured speaking tasks were included for comparison of electroglottography measures: a paragraph reading task and a sustained vowel.Results: Lung volume termination level in spontaneous speaking was significantly lower for the teachers with voice disorders relative to teachers without voice problems. Lung volume initiation level was lower for the teachers with versus without voice problems during teaching-related speaking tasks. Laryngeal function as assessed with electroglottography did not show between-group differences. Across tasks, the measure of contact index was lower (more negative) during the conversational speaking task as compared to the sustained vowel task, indicating greater contact phase asymmetry during vocal fold vibration.Conclusions: These findings suggest that teachers with a voice disorder use different speech breathing strategies than teachers without voice problems. Management of teachers with voice problems may need to incorporate respiratory training that alters lung volume levels during speaking. Future research is needed to determine whether altering such patterns results in improved voice parameters and self-perceived improvement in vocal symptoms.

Spontaneous imbibition of water into Fontainebleau Sandstone matrix because of capillary gradient is an important mechanism for oil recovery from Fontainebleau Sandstone reservoirs. Spontaneous imbibition characteristics of Fontainebleau Sandstone core were determined by measuring the Wettability Index of four Fontainebleau Sandstone core samples under laboratory conditions. This was done by utilizing a combination of a Benchtop Relative Permeameter Flooding System and Amott Cups. The specimen had a diameter of 38mm and a height of 47mm. Permeability and porosity of the cores varied from 12 to 14 mD and 10 to 14% respectively. The fluids and chemicals used were kerosene, synthetic brine and Sodium dodecyl sulphate. Amott’s method was used to measure the wettability index. This method consists of four steps: (1) brine flooding, (2) spontaneous imbibition of brine, (3) kerosene flooding, (4) spontaneous imbibition of kerosene. One core was saturated with kerosene and then flooded with brine, followed by spontaneous imbibition of brine. Similarly, another core was saturated with brine and then flooded with kerosene, followed by spontaneous imbibition of kerosene. Similar procedures were used for other two cores except the addition of surfactant to the synthetic brine. All cores were then cleaned and re-saturated for spontaneous imbibition of kerosene and brine. All Experiments were performed under laboratory temperature conditions. Oil and water wettability values were obtained along with secondary and tertiary oil recoveries. These values were used to calculate the wettability index of Fontainebleau sandstone cores. Spontaneous imbibition characteristics of the cores obtained from the experimental data indicate that Fontainebleau Sandstone formation is a potential candidate for Secondary and Tertiary oil recovery by water injection and spontaneous imbibition.

This thesis presents the study of films derived from the reduction of aryldiazonium salts at gold surfaces. The properties of bare polycrystalline surfaces were investigated via the observation of the electrochemical oxidation and reduction of the gold. Films derived from diazonium salts were electrochemically grafted to the gold surface. The structure and stability of these interfaces was examined through the use of redox probes, gold oxide electrochemistry and water contact angle measurements. The spontaneous reduction of aryldiazonium salts at gold surfaces was investigated and the possible applications it presented towards printing and patterning of the gold surface with films were explained. Polycrystalline gold surfaces were prepared and subjected to various treatments, to observe the behaviour of gold oxide formation and reduction at the surface. Various effects on the surface structure were observed after treatment in solvents and electrolyte solutions. The surface structure of the gold atoms frequently changed due to the high mobilities of the gold atoms, and it is difficult to achieve a reproducibly stable surface. The electrochemical modification of gold surfaces via the reduction of aryldiazonium salts was investigated. Surfaces were modified with methylphenyl and carboxyphenyl films and exposed to various treatments. Monitoring the gold oxide reduction changes enabled the surface coverage of modifier directly attached to the surface to be calculated. The films appear to be stable, loosely packed and porous. The films are flexible in nature; redox probe responses showed reversible changes after repeated sonication in solvents of differing polarities and hydrophilicities. Contact angle measurements further support the notion of films that can reorganise in response to their environment. The spontaneous reduction of aryldiazonium salts at gold surfaces was observed. Film coverage was significantly lower at the spontaneously grafted surface than for films grafted electrochemically. Gold surfaces were successfully modified via microcontact printing, and surface coverages similar to the spontaneously grafted film were achieved. Microcontact printing was also used to pattern surfaces with films derived from diazonium salts. Feature sizes down to 100 µm were successfully achieved.

The purpose of this study was to explore imitation in Autism Spectrum Disorder (ASD) by (a) examining the ability of children with ASD to engage in deferred imitation, as compared to typically developing (TD) children; (b) determining the impact of differing time delays on the ability of children with ASD and TD children to imitate simple actions on objects; and (c) examining the role of a verbal prompt on the ability of children with ASD to engage in deferred imitation, as compared to TD controls. Additionally, the role of language in deferred imitation was explored. Participants included 15 children with ASD and 15 TD children. Participants observed object oriented actions and were given the opportunity to imitate spontaneously. Those participants who did not imitate spontaneously were given a verbal prompt and a further opportunity to imitate. Participants with ASD demonstrated fewer spontaneous and total (i.e. spontaneous and prompted) imitations and took more time to do so at a short and a longer time delay, as compared to TD participants. Participants with ASD were given more verbal prompts than TD participants at a short and a longer time delay. Language was related to deferred imitation at a short time delay for participants with ASD but not for TD participants and language was not related to deferred imitation at a longer time delay for either group. / Graduate / 0525 / 0529

Low phosphorus content steels are essential for steel applications where high ductility is required, such as thin sheets, deep drawn, pipelines and automobile exteriors. In the past, phosphorus control was not considered a big challenge in steel production in the US because iron ores with low phosphorus contents were readily available and considered cheap. However, in the last decade, the iron ore price has risen by roughly 400% and lower cost iron sources generally have higher phosphorus content. In integrated steel plants, phosphorus removal usually takes place during the oxygen steelmaking process (OSM) but in Japan a intermediate step for hot metal dephosphorization is commonly used. There are various types of OSM furnaces but the most widely used remains the top-blown Basic Oxygen Furnace (BOF). The BOF slag can be recycled to a sinter plant or directly to the blast furnace, ultimately increasing the phosphorus input in the process. In order to meet new demands for phosphorus control, it is necessary to improve our understanding on the thermodynamics and kinetics of the phosphorus partitioning reaction between slag and metal melts during steelmaking. Therefore, the present work has been divided in three strongly correlated sections: phosphorus equilibrium between metal and slag; analysis of plant data; and observations of the reaction kinetics. Phosphorus equilibrium between liquid metal and slag has been extensively studied since the 1940's. It is well known that CaO and FeO are the main slag constituents that help promote dephosphorization. On the other hand, dephosphorization decreases with temperature due to the endothermic nature of the reaction. Many correlations have been developed to predict the phosphorus partition ratio as a function of metal and slag composition as well as temperature. Nevertheless, there are still disagreements in the laboratory data and the equilibrium phosphorus partition can be predicted with an uncertainty of a factor of up to 5. The first part of the present work focuses on generating more reliable equilibrium data for BOF-type slags by approaching equilibrium from both sides of the reaction. The experimental results were combined with two other sets of data from different authors to produce a new correlation that includes the effect of SiO2 on the phosphorus partition coefficient, LP . Although the quantification of phosphorus equilibrium is extremely important, most industrial furnaces do not operate at equilibrium, usually due to liquid slag formation, kinetics and time constraints. Thus, it is important to know how close to equilibrium different furnaces operate in order to suggest optimal slag compositions to promote dephosphorization. The present work analyzed four large sets of data containing the chemical compositions of both slag and metal phase as well as the tapping temperature of each heat. Each set of data corresponded to different furnaces: one AOD (Argon Oxygen Decarburization), two top-blown BOFs and one Q-BOP or OBM. It was found that the bulk slag composition can greatly \mask" the data due to solid phases coexisting with the liquid slag. The author used the software package FactSage to estimate the amount of solids in the slag and liquid slag composition. It was found that the AOD is the reactor closest to equilibrium, followed by the Q-BOP (OBM) and the two top-blown BOFs. It was noted that the stirring conditions and slag composition are two key variables to enable optimum phosphorus removal. Also, over saturating the slag with CaO and MgO does not seem to benefit the process to any extent. Lastly, interesting observations on the behavior of small metal droplets reacting with slag are presented and discussed. It was found that dynamic interfacial phenomena at the metal-slag interface is likely to play a significant role in the kinetic behavior of the system, due to the exchange of surface active elements, such as oxygen, which dramatically lowers the interfacial tension and cause spontaneous emulsification. Although this phenomenon has been studied, actual quantification of changes in interfacial area remain a challenge. The author developed an experimental method to enable better quantification of spontaneous emulsification and two sets of experiments were carried. One with an Fe containing 0.2 wt.% P and another in a P-free system where pure iron was oxidized. It was found that phosphorus did not play a role in spontaneous emulsification and it was rapidly removed before the onset of dynamic interfacial phenomena. Emulsificaion was maybe caused by de-oxidation of the metal after phosphorus removal took place and the metal became super saturated with oxygen by an unknown reason. The estimated surface area rapidly increases by over an order of magnitude during the beginning and intermediate periods of the reaction. The metal drop breaks into hundreds of small droplets, effectively emulsifying the metal into the slag. With time, the surface area decreases and the metal droplets coalesce. Similar results were observed for an Fe droplet being oxidized. Spontaneous emulsification takes place regardless of the direction of oxygen transfer and the changes in surface area are similar for both cases. The last chapter describes the industrial relevance of the present work, summarizes the findings, revisits the hypotheses and presents potential future work where further research is encouraged.

When spontaneous breathing (SB) is allowed during mechanical ventilation (MV), atelectatic lung areas are recruited and oxygenation improves thereby. Whether unsupported SB at its natural pattern (without PEEP and at low pressure/small tidal volume) equally recruits and improves oxygenation, and if so by which mechanism, has not been studied. A porcine lung collapse model was designed to study this question. The cardiac output dependency of the pulmonary shunt was investigated with healthy lungs and with major shunt (during one-lung ventilation) and with SB, MV and continuous positive airway pressure (CPAP). The hypoxic pulmonary vasoconstriction (HPV) was blocked with sodium nitroprusside (SNP) to see whether HPV is the only mechanism available for ventilation/perfusion (VA/Q) matching during MV and SB. In all experiments, respiratory rate and tidal volume during MV were matched to SB. Oxygenation was assessed by serial blood gas measurements, recruitment by thoracic CTs; pulmonary shunt was assessed by multiple inert gas elimination or venous admixture. SB attained better oxygenation and lower pulmonary shunt compared with MV, although it did not recruit collapsed lung. Pulmonary shunt did not correlate with cardiac output during SB, whereas a correlation was found during MV and CPAP. With blocked HPV, pulmonary shunt was considerably lower during SB than MV. In conclusion, SB improves VA/Q matching as compared with MV, even when no recruitment occurs. In contrast to MV and CPAP, cardiac output has no major effect on pulmonary shunt during SB. The improved VA/Q matching during SB despite a blocked HPV might indicate the presence of a SB-specific mechanism that improves pulmonary blood flow redistribution towards ventilated lung regions independent of or supplementary to HPV.

This thesis presents the study of films derived from the reduction of aryldiazonium salts at gold surfaces. The properties of bare polycrystalline surfaces were investigated via the observation of the electrochemical oxidation and reduction of the gold. Films derived from diazonium salts were electrochemically grafted to the gold surface. The structure and stability of these interfaces was examined through the use of redox probes, gold oxide electrochemistry and water contact angle measurements. The spontaneous reduction of aryldiazonium salts at gold surfaces was investigated and the possible applications it presented towards printing and patterning of the gold surface with films were explained. Polycrystalline gold surfaces were prepared and subjected to various treatments, to observe the behaviour of gold oxide formation and reduction at the surface. Various effects on the surface structure were observed after treatment in solvents and electrolyte solutions. The surface structure of the gold atoms frequently changed due to the high mobilities of the gold atoms, and it is difficult to achieve a reproducibly stable surface. The electrochemical modification of gold surfaces via the reduction of aryldiazonium salts was investigated. Surfaces were modified with methylphenyl and carboxyphenyl films and exposed to various treatments. Monitoring the gold oxide reduction changes enabled the surface coverage of modifier directly attached to the surface to be calculated. The films appear to be stable, loosely packed and porous. The films are flexible in nature; redox probe responses showed reversible changes after repeated sonication in solvents of differing polarities and hydrophilicities. Contact angle measurements further support the notion of films that can reorganise in response to their environment. The spontaneous reduction of aryldiazonium salts at gold surfaces was observed. Film coverage was significantly lower at the spontaneously grafted surface than for films grafted electrochemically. Gold surfaces were successfully modified via microcontact printing, and surface coverages similar to the spontaneously grafted film were achieved. Microcontact printing was also used to pattern surfaces with films derived from diazonium salts. Feature sizes down to 100 µm were successfully achieved.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2009. / Härtill 4 uppsatser.

BACKGROUND: Despite decades of research aimed at prevention, preterm birth remains an enormous leading cause of infant mortality in the United States and worldwide. Of concern, racial disparities in preterm birth remain an intractable public health issue. In an effort to reduce preterm birth, organizations such as the American Congress of Obstetricians and Gynecologists (ACOG) released policy statements in 2009 aimed at reducing early elective deliveries. Subsequently, the incidence of preterm birth in the United States has decreased, but whether this decrease is due to a reduction in iatrogenic or "medically-indicated" preterm birth is unknown. Further, the effect of the reduction in early elective deliveries on racial disparities is unknown. Our hypotheses were that 1) after 2009, preterm births would be less likely to be medically-indicated than due to spontaneous causes and 2) black-white differences in preterm births would be unchanged. OBJECTIVES: 1) Determine the proportion of preterm deliveries at Beth Israel Deaconess Medical Center (BIDMC) from 2004-2013 that were medically-indicated versus spontaneous. 2) Due to persistent disparities, determine if shifts in type of preterm delivery varied by race/ethnicity. METHODS: We reviewed the first 87 deliveries in 2013 and randomly selected 15% of the records for each year from 2004-2013. Additionally, we reviewed 69 charts to oversample black women's deliveries. We manually abstracted data from BIDMC's online medical record and designated each delivery as either medically-indicated (preeclampsia, poor fetal growth, hypertension, or other fetal/maternal condition) or spontaneous (preterm labor, preterm premature rupture of membranes or cervical incompetence). Two reviewers independently reviewed 18 records for concordance of medically-indicated versus spontaneous preterm birth typing. If the first reviewer could not phenotype the delivery, then a neonatologist and obstetrician were consulted. We reviewed 971 out of the 5,566 preterm deliveries and included 930 that were confirmed preterm and had a clear medically-indicated or spontaneous phenotype. We dichotomized the time period into early (2004-2009) and late (2010-2013). Statistical methods included comparisons of early versus late using Chi-Square tests, logistic regression models to adjust for potential confounding variables, and stratified analyses (singletons and black versus white). RESULTS: There were 46,981 deliveries at our institution during the study period, 5,566 of which were preterm. Among the 930 preterm deliveries sampled from the 10-year period, 45.6% were medically-indicated with a non-significant, subtle difference between the early (48.3%) and late (41.9%) (P=0.05) time periods. The odds ratios of medically-indicated versus spontaneous preterm birth in late versus early were 0.77 (P=0.05) and 0.73 (P=0.03) for all participants, unadjusted and adjusted, respectively. While not statistically significant, a higher proportion of preterm deliveries among black women were medically-indicated in the early (50.4%) versus late (40.6%) periods (P=0.19). There was a similar trend among white women between the early (50.0%) and late (46.9%) periods (P=0.48). The odds ratios of medically-indicated versus spontaneous preterm birth from late versus early were 0.67 (P=0.19) and 0.63 (P=0.14) for black participants, unadjusted and adjusted, respectively. For white participants, the odds ratios were 0.88 (P=0.48) for unadjusted and 0.80 for adjusted (P=0.20). Overall at BIDMC, the preterm delivery rate was significantly higher in the early period (12.3%) compared to the later period (11.2%) (P=0.0003). While we observed a reduction of preterm birth among all women, black women experienced a 20.8% decrease (from 16.2% in the early period to 12.8% in the late) in preterm birth, while white women experienced just a 4.9% decrease (from 12.4% to 11.7%), resulting in a narrowing of the racial disparity of preterm birth in our institution. CONCLUSION: At a Massachusetts birth hospital we found a reduction in the incidence of preterm deliveries over a 10-year period that coincided with policy efforts to reduce early elective deliveries. There was a reduction in the proportion of preterm births that were medically-indicated from 48.3% to 41.9%. The reduction in medically-indicated preterm birth was most evident among black women at BIDMC with concurrent decrease in the overall preterm birth rate among black women resulting in a near elimination of the racial disparity in preterm birth at BIDMC. Future work includes statistical analysis to account for the oversampling of deliveries in 2013 as well as oversampling of black women's deliveries using inverse probability weighting. We also plan to analyze which underlying conditions (preeclampsia, intrauterine growth restriction, fetal distress, etc.) were responsible for the reduction of the medically-indicated deliveries.

OBJECTIVES: 1) To measure the prevalence of precipitating events in pediatric chronic pain patients and 2) to compare pain and functional disability outcomes at evaluation and 4-month follow-up by presence and type of precipitating event. METHODS: Precipitating events (e.g., injury) were coded from the medical record for 401 youth (6-19) who presented to a tertiary care chronic pain clinic. Four-month follow-up disability and pain were collected for 187 patients. In addition to frequency of events, we examined differences in pain and disability measures by event type at evaluation and follow-up using multiple statistical analysis strategies. RESULTS: Two-thirds of patients had a precipitating event prior to pain onset. Injury was the most common (55%), followed by chronic disease (23%), infection/illness (12.8%), and surgery (7.5%). Patients whose pain was triggered by injury reported the highest average pain levels, F(3, 340)=2.67, p<.05 and functional disability, F(3, 295)=3.54, p<.05. There were multiple cases of event groups that had significantly different baseline and follow-up psychological measures when compared to the rest of the patient population. Trajectories of pain and disability did not differ between patients with and without a precipitating event. Patients with injuries reported greater improvement in functional disability at follow-up (time x injury) F(1, 183)=4.88, p<.05 whereas patients with chronic disease reported less improvement in disability (time x chronic disease), F(1, 183)=5.49, p<.05. No other interactions were significant for disability or pain. CONCLUSIONS: A majority of patients had experienced some form of precipitating event prior to their pain onset, and the presence of a precipitating event had varied effects on the treatment outcomes of patients at four-month follow-up. Although patients with injuries presented with greater disability and pain, they had significantly more improvement, while chronic disease patients were less likely to improve in terms of functional disability. Type of precipitating event appears to be associated with treatment response and can inform clinical prognoses.