abstract: The division of domestic labor has far-reaching implications for "private" life (e.g. relational satisfaction and conflict) and for "public" paid labor (e.g. time and dedication in the workplace and career advancement). Although several theories have been developed and tested, they do not sufficiently explain the consistent findings that women in mixed sex households perform a majority of the domestic labor. Without understanding the causes for differences in task performance, past research encouraging communicative solutions to ameliorate conflict was ineffective in changing task allocation and performance. Therefore, it is necessary to understand theoretical explanations that drive domestic labor behavior to develop effective solutions. The recent integrative theory of the division of domestic labor attempts to explain how individuals interact with household partners to allocate domestic tasks. Recognizing the complexity of the division of domestic labor, the integrative theory considers individual, dyadic, and societal factors that influence task allocation. Because clear differences in task performance have been found in mixed sex households, this study separates sex and gender as distinct variables by considering same-sex roommate relationships, essentially removing sex differences from the living arrangement. Furthermore, this study considers individual threshold levels as described by the integrative theory in order to test the theoretical underpinnings. Specifically, this study is designed to investigate the relationships between individual cleanliness threshold levels and gender, sex, perceptions of satisfaction, equity, and frequency of conflict in same-sex roommate relationships. Results indicate support of the integrative theory of the division of domestic labor. Regarding gender differences, partial support for the theory appeared in that feminine individuals have lower threshold levels than masculine individuals. Regarding sex differences, women possess lower individual threshold levels (i.e. more bothered when a task is undone) compared to men, which likely accounts for why existing research indicates that women spend more time performing domestic tasks. What is more, individuals with higher threshold levels report greater relational satisfaction. Further, individuals whose threshold levels differ from their living partner report lower relational satisfaction and greater conflict frequency. Finally, in terms of equity, both overbenefited and underbenefited individuals experience more conflict than those who feel their relationship is equitable. These results provide theoretical support for the integrative theory of the division of labor. Furthermore, the development and testing of a threshold measure scale can be used practically for future research and for better roommate pairings by universities. In addition, communication scholars, family practitioners and counselors, and universities can apply these theoretically grounded research findings to develop and test strategies to reduce conflict and increase relational satisfaction among roommates and couples. / Dissertation/Thesis / Ph.D. Communication 2011

Sporadic problems with pink color defect, or pinking, has occurred in cooked meat products for decades. Pink color can be due to the presence of undenatured myoglobin, denatured globin hemochromes, or nitrosylhemochrome. This research documented the level of added nitrite that produced nitrosylhemochrome in processed meat rolls from fabricated beef round, pork shoulder, turkey breast, and chicken breast. For each meat type, preliminary studies were conducted to narrow the range at which added nitrite caused pinking. Subsequently, the nitrite levels were increased incrementally by 1-ppm, and pink color was measured by trained panelists and by a Hunter color meter. Nitrosylhemochrome content was determined by acetone extraction. Panel and instrumental measurements identified pink color in beef samples formulated with 14-ppm nitrite; nitrosohemochrome extracts detected pigment at 12- ppm. Nitrite levels that caused pinking in pork shoulder were much lower than in beef. Panelists identified pink color at 4-ppm nitrite, and Hunter color meter values showed increased redness at 6-ppm. Pigment extraction detected nitrosylhemochrome at 4- ppm added nitrite. The trained panel and Hunter color meter detected pink color in turkey breast at 2-ppm added nitrite; nitrosohemochrome extraction detected pink pigment at 3-ppm added nitrite. In chicken breast, pink color was detected visually and instrumentally at 1-ppm added nitrite. Pigment extraction detected nitrosylhemochrome at 2-ppm added nitrite. Lower levels of nitrite (1-3-ppm) caused pinking in light-colored meats (turkey and chicken breast, meats with total pigment between 19-ppm and 27-ppm). Higher levels of nitrite (5-14-ppm) caused pink color defect in dark pigmented meat (beef round and pork shoulder, meats with total pigment levels between 56-ppm and 147-ppm). Regression analysis was used to relate total pigment and the minimum level of nitrite causing pinking. The minimum nitrite level causing pinking was the lowest level of nitrite at which the trained panel, acetone extraction, and instrumental results detected pink color or nitrosyl pigment. The formula obtained from the model was as follows: Y = 0.092X + 0.53, where "Y" is the minimum level of added nitrite to cause pinking and "X" is the total pigment of the meat. This formula can be used to estimate the level of nitrite that can be expected to cause pinking in a wide range of pigmented meats.

Traumatic brain injury (TBI) is a major cause of death and disability. TBI is frequently followed by cerebral ischemia which is a great contributor to secondary brain damage. The main causes of cerebral ischemia are pathophysiological changes in cerebral blood flow and metabolism. Treatment of TBI patients is currently based on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) targeted treatment protocols. However, ICP and CPP alone do not provide information of the oxygen availability in the brain. Monitoring of brain tissue oxygenation (BtipO2) may give additional and valuable information about the risk for development of ischemia in TBI patients. The aims of this thesis were to study BtipO2 monitoring devices in-vitro regarding accuracy and stability, to detect threshold level of cerebral ischemia in-vivo and finally to examine the cerebral oxygen levels and cerebral metabolism in TBI patients. The BtipO2 probes performed with high accuracy and stability at different clinically relevant oxygen concentrations. A pig TBI model was developed by step-wise intracranial volume/pressure increase. Volume increase resulted in a gradual increased ICP, decreased CPP, intracranial compliance and BtipO2, respectively. Brain death (BD) was confirmed by negative CPP and negligible amount of previously injected microspheres in the brain tissue. The model simulated the clinical development of BD in humans with a classical pressure-volume response and systemic cardiovascular reactions. The model should be suitable for studies of brain injury mechanisms. From the same in-vivo model it was also possible to detect the threshold level of cerebral ischemia in the pig, where BtipO2 below 10 mmHg and CPP below 30 mmHg was associated with an impaired cerebral metabolism (microdialysis lactate to pyruvate ratio >30). BtipO2 together with cerebral microdialysis were studied in 23 severe TBI patients. We observed different patterns of changes in BtipO2 and cerebral microdialysis biomarkers in focal and diffuse TBI.  Increased cerebral microdialysis levels of glutamate, glycerol or the lactate/pyruvate ratio were observed at BtipO2 < 5 mmHg, indicating increased vulnerability of the brain at this critical level of tissue oxygenation in TBI patients.

Diagnostic systems become more and more an important within the field of vehicle systems. This is much because new rules and regulation forcing the manufacturer of heavy duty trucks to survey the emission process in its engines during the whole lifetime of the truck. To do this a diagnostic system has to be implemented which always survey the process and check that the thresholds of the emissions set by the government not are exceeded. There is also a demand that this system should be reliable, i.e. not producing false alarms or missed detection. One way of producing such a system is to use model based diagnosis system where thresholds has to be set deciding if the system is corrupt or not. There is a lot of difficulties involved in this. Firstly, there is no way of knowing if the signals logged are corrupt or not. This is because faults in these signals should be detected. Secondly, because of strict demand of reliability the thresholds has to be set where there is very low probability of finding values while driving. In this thesis a methodology is proposed for setting thresholds in a diagnosis system in an experimental test engine at Scania. Measurement data has been logged over 20 hours of effective driving by two individuals of the same engine. It is shown that the result is improved significantly by using this method and the threshold can be set so smaller faults in the system reliably can be detected.

<p>Diagnostic systems become more and more an important within the field of vehicle systems. This is much because new rules and regulation forcing the manufacturer of heavy duty trucks to survey the emission process in its engines during the whole lifetime of the truck. To do this a diagnostic system has to be implemented which always survey the process and check that the thresholds of the emissions set by the government not are exceeded. There is also a demand that this system should be reliable, i.e. not producing false alarms or missed detection. One way of producing such a system is to use model based diagnosis system where thresholds has to be set deciding if the system is corrupt or not. There is a lot of difficulties involved in this. Firstly, there is no way of knowing if the signals logged are corrupt or not. This is because faults in these signals should be detected. Secondly, because of strict demand of reliability the thresholds has to be set where there is very low probability of finding values while driving. In this thesis a methodology is proposed for setting thresholds in a diagnosis system in an experimental test engine at Scania. Measurement data has been logged over 20 hours of effective driving by two individuals of the same engine. It is shown that the result is improved significantly by using this method and the threshold can be set so smaller faults in the system reliably can be detected.</p>

Background The noise-exposed population in the mining industry in South Africa poses unique problems to the occupational audiologist working in this environment, due to the broad linguistic and cultural diversity in the audiology and mining environment. Unfortunately, the problems are also exacerbated by a high incidence of pseudohypacusis within this population who are incentivised by compensation for NIHL. A solution to these specific problems would be the reliable and valid use of an objective test of function such as the DPOAE. The rationale for the study therefore was to extend the body of knowledge about the use of DPOAEs in the noise-exposed mining population. Methodology The current study was divided into two phases: phase one’s objectives entailed the investigation of the characteristics of DPOAEs in a noise-exposed mining population; phase two aimed to develop a multivariate regression model that would facilitate the prediction of the hearing threshold levels from the DPOAE levels in this population. Objectives The objectives in phase one of the study were to investigate the bivariate correlations between DPOAE levels and air-conduction hearing threshold levels in noise-exposed gold miners, for the three stimulus procedures. The study also aimed to investigate the bivariate correlations between various pure-tone averages (PTA) and the DPOAE averages of f2 frequencies closest to those pure-tone frequencies. Similarly, the Speech Recognition Thresholds (SRT) were correlated with DPOAE averages of f2 frequencies closest to the PTA. xx The study further aimed to investigate the characteristics of DPOAEs in noiseexposed gold miners by comparing the average DPOAE levels for different age category groups, different ethnic groups and for different occupation types. Finally, phase one aimed to describe the characteristics of emission level and noise floor differences (DP-NF) in a DPOAE database of a noise-exposed gold mining population. Phase two of the study had the objective of developing a multivariate prediction model using stepwise regression analysis to identify which of the DPOAE frequencies produced the best prediction of the audiogram frequencies when multivariate inputs were used for each stimulus procedure. The objective was also to evaluate the use of the predicted audiograms’ calculated percentage loss of hearing (PLH) with that of the actual PLH. This retrospective record review used an audiological database from a mine in the North West province of South Africa that contained 4800 records. The required sample size to be representative of the population was statistically determined. The records were randomly selected resulting a sample size for the FB2-S group of 161, for the FB1-S group of 177 and the FB1-S group of 155 respectively. The hearing loss characteristics in the samples ranged from normal to profound losses with the majority being mild to moderate hearing losses. Results The findings of phase one showed negative correlations ranging from -0.327 to -0.573 for Frequency Band 1- Replicated (FB1-R) between DPOAE levels and air conduction hearing threshold levels. Similarly, Frequency Band 1-Single (FB1-S) and Frequency Band 2-Single (FB2-S) also showed negative correlations (ranging from -0.203 to -0.609 and -0.274 to -0.738 respectively). These correlation strengths have been confirmed previously by other published studies. xxi Correlations between groups of frequencies on an audiogram and averaged match groups of DPOAE frequencies by intensity levels, both for PTA and SRT, ranged between -0.323 and -0.661. No statistically significant differences were found between the DPOAE measurements and ethnic groups of African and Caucasian (Sample size of 175 for FB1-S, 137 for FB1-R and 161 for FB2-S). No differences were found between the DPOAE levels and the occupation types of mining team members, stopers and drillers. There was, however, a relational finding of a progressive decrement of DPOAE intensity levels by decade of age increase (Sample size of 37 for FB1-S, 45 for FB1-R and 155 for FB2-S). Mean DP levels in this population ranged from 1.5 to -14 dB SPL, and mean NF levels in the sample ranged from 0.1 to -16.8 dB SPL with the mean DP-NF difference ranges form 0.4 to 9.3 dBSPL. More than 60% of the data collected resulted in a DP-NF of less than 10 dB SPL. The simple correlation relationship between hearing threshold levels and DPOAEs did not sufficiently explain the variance within the sample and due to the fact that a number of the independent variables in the sample were highly correlated, there was a call to use a method that allows for multicolinearity (i.e. stepwise regression analysis) in order to develop a prediction model. Consequently, phase two of the study was able to compare actual air-conduction hearing threshold levels with those calculated with the prediction model, and then calculate predicted percentage loss of hearing (PLH) with actual PLH found in the noise-exposed gold miners. In phase two, with the use of the predictive models, the predicted hearing threshold levels were found to differ from the actual thresholds by no more than 7dB HL across all frequencies (average of 5 dB HL for FB1-R, 2 dB HL for FB1-S and 3 dB HL for FB2-S). The differences for each audiogram frequency between the actual and the predicted thresholds are represented on scatter plots in phase two of the thesis. The PLH of the predicted audiograms was calculated using the weighted xxii tables prescribed by the Compensation for Occupational Diseases and Injuries Act (COIDA). A comparison of the predicted PLH with the actual PLH indicated that the predicted PLH ranged between minus 1.3% PLH and plus 6.7% PLH of the actual PLH. Results of the study are discussed with regards to the clinical implications, and the implications for training occupational audiologists in South Africa. The results of this study will improve and inform practice in the mining environment and in the field of compensation for NIHL. By developing a reliable prediction tool which is implemented on an objective test proven to document the extent of damage incurred from noise-exposure, a clinician will gain greater confidence in an accurate diagnosis, thereby further safeguarding a vulnerable population. The results from this study are highly relevant to the mining industry and will add value to the industrial development of South Africa by informing the policy on hearing conservation and compensation, thereby increasing the awareness of the need for improved occupational health and safety conditions and sustainable development in the mining industry.

O trabalho teve como foco o estudo da balneabilidade em duas praias de rios do Estado de São Paulo Balneário Reino das Águas Claras no Rio Piracuama (Pindamonhangaba, UGRHI 2) e Cachoeira das Emas no Rio Mogi-Guaçu (Pirassununga, UGRHI 9) buscando correlacionar os níveis de concentração de indicadores fecais na água com níveis de precipitação próximos e a montante da praia. O objetivo principal foi desenvolver e aplicar ferramentas de predição das condições de balneabilidade, buscando analisar e comparar os resultados obtidos nas duas praias de estudo. Essas ferramentas baseiam-se em Níveis Limiares de Precipitação (Rain Threshold Levels) e modelos estatísticos, conforme metodologias descritas principalmente em estudos publicados pela United States Environmental Protection Agency (USEPA) e pela United States Geological Survey (USGS). Foram utilizados dados das redes de monitoramento da Companhia Ambiental do Estado de São Paulo (CETESB) e do Departamento de Águas e Energia do Estado de São Paulo (DAEE), do início de 2009 ao final de 2012. Em cada praia, foram desenvolvidas ferramentas de predição para aplicação no período seco (abril a setembro) e no período chuvoso (outubro a março), com base nos níveis de precipitação acumulada em 24, 48 e 72 horas que apresentaram correlação significativa com os níveis de indicadores fecais na água. Foi considerado um período de validação (ano de 2012) independente à calibração (2009 a 2011) dos modelos. As ferramentas desenvolvidas para a praia de Cachoeira das Emas mostraram-se mais complexas do que as da praia de Balneário Reino das Águas Claras, por estar inserida em bacia hidrográfica de maiores dimensões e considerar dados de várias estações pluviométricas nos modelos de regressão. As correlações significantes (p<0,05) verificadas entre as concentrações de indicadores fecais na água e os diferentes níveis acumulados de precipitação foram positivas em ambas as praias. Pelo fato das redes de monitoramento possuir objetivos distintos, nem todos os eventos de precipitação que ocorreram durante o período de estudo puderam ser relacionados com um valor de concentração de indicador fecal na água, pois resultados microbiológicos pareados com níveis nulos ou insignificantes de precipitação não foram considerados, justamente pelo fato das ferramentas serem baseadas em chuva. As diferentes ferramentas desenvolvidas apresentaram níveis variados de especificidade e sensibilidade, ou seja, a capacidade de prever corretamente as situações de boa e má condição de balneabilidade, respectivamente. Concluiu-se que existe potencial para aplicação dessas ferramentas, porém é preciso um esforço de monitoramento conjunto dos parâmetros modelados para obter a quantidade necessária de dados necessários à boa calibração e validação, o que, consequentemente, demandaria recursos adicionais. O cenário ideal para empregá-las seria em praias bastante frequentadas num determinado período do ano, sendo a principal fonte de poluição identificada como difusa, consequente do escoamento de drenagem. A fim de melhorar seu desempenho, é possível empregar outras variáveis ambientais além de níveis de precipitação, como por exemplo, a turbidez, a vazão e o nível dos rios, desde que sejam monitorados sistematicamente junto com as condições de balneabilidade. / This study was focused on the recreational water quality at two beaches located on rivers in the State of São Paulo, Brazil Balneário Reino das Águas Claras at Piracuama River (City of Pindamonhangaba, UGRHI 2) and Cachoeira das Emas at Mogi-Guacú River (City of Pirassununga, UGRHI 9) in order to correlate concentration levels of faecal indicators in water with rainfall levels near the beach and upstream in the watershed. The main objective was the development and evaluation of predictive tools for bathing water conditions, seeking to analyze and compare the results obtained for both beaches considered in the study. These tools are based on rain threshold levels and statistical models, which methodologies are described mainly in studies published by the United States Environmental Protection Agency (USEPA) and the United States Geological Survey (USGS). Data used were collected from the monitoring networks of the State of São Paulo environmental agency (CETESB) and department of water and energy (DAEE), from 2009 to 2012. At each beach, predictive tools were developed for the dry season (April to September) and the rainy season (October to March), based on levels of accumulated rainfall in 24, 48 and 72 hours significantly correlated with concentrations of faecal indicators in water. Model development considered a validation period (year of 2012) independent from the calibration period (2009-2011). Predictive tools developed for the Cachoeira das Emas were more complex than those for the Balneário Reino das Águas Claras, because the beach is inserted into a larger watershed and its regression models considered data from various rainfall stations. The significant correlations (p value<0,05) observed between concentrations of faecal indicators in water and accumulated levels of rainfall were positive for both beaches. Because the monitoring networks have different objectives, not all rainfall events that occurred during the period of the study were related to a concentration value of faecal indicator in the water, as microbiological results paired with null or insignificant levels of precipitation were not considered, precisely because the predictive tools are based on rainfall. The different tools developed showed varying levels of specificity and sensitivity, i.e., the ability to correctly predict good and bad conditions of bathing. The conclusion is that there is a potential for application of predictive tools, however, additional effort is required on monitoring systematically the models parameters in order to obtain the necessary amount of data to achieve a good calibration and validation of the models; consequently, additional resources are required. The ideal scenario would be using the model during a certain period of the year, at beaches quite frequented, for which diffuse pollution is the main contribution, such as the drainage runoff. Aiming to improve the performance of this type of tool, one can also employ other environmental variables besides precipitation levels, such as turbidity, flow rate and river level, as long as these parameters are systematically monitored with the bathing water conditions.

O trabalho teve como foco o estudo da balneabilidade em duas praias de rios do Estado de São Paulo Balneário Reino das Águas Claras no Rio Piracuama (Pindamonhangaba, UGRHI 2) e Cachoeira das Emas no Rio Mogi-Guaçu (Pirassununga, UGRHI 9) buscando correlacionar os níveis de concentração de indicadores fecais na água com níveis de precipitação próximos e a montante da praia. O objetivo principal foi desenvolver e aplicar ferramentas de predição das condições de balneabilidade, buscando analisar e comparar os resultados obtidos nas duas praias de estudo. Essas ferramentas baseiam-se em Níveis Limiares de Precipitação (Rain Threshold Levels) e modelos estatísticos, conforme metodologias descritas principalmente em estudos publicados pela United States Environmental Protection Agency (USEPA) e pela United States Geological Survey (USGS). Foram utilizados dados das redes de monitoramento da Companhia Ambiental do Estado de São Paulo (CETESB) e do Departamento de Águas e Energia do Estado de São Paulo (DAEE), do início de 2009 ao final de 2012. Em cada praia, foram desenvolvidas ferramentas de predição para aplicação no período seco (abril a setembro) e no período chuvoso (outubro a março), com base nos níveis de precipitação acumulada em 24, 48 e 72 horas que apresentaram correlação significativa com os níveis de indicadores fecais na água. Foi considerado um período de validação (ano de 2012) independente à calibração (2009 a 2011) dos modelos. As ferramentas desenvolvidas para a praia de Cachoeira das Emas mostraram-se mais complexas do que as da praia de Balneário Reino das Águas Claras, por estar inserida em bacia hidrográfica de maiores dimensões e considerar dados de várias estações pluviométricas nos modelos de regressão. As correlações significantes (p<0,05) verificadas entre as concentrações de indicadores fecais na água e os diferentes níveis acumulados de precipitação foram positivas em ambas as praias. Pelo fato das redes de monitoramento possuir objetivos distintos, nem todos os eventos de precipitação que ocorreram durante o período de estudo puderam ser relacionados com um valor de concentração de indicador fecal na água, pois resultados microbiológicos pareados com níveis nulos ou insignificantes de precipitação não foram considerados, justamente pelo fato das ferramentas serem baseadas em chuva. As diferentes ferramentas desenvolvidas apresentaram níveis variados de especificidade e sensibilidade, ou seja, a capacidade de prever corretamente as situações de boa e má condição de balneabilidade, respectivamente. Concluiu-se que existe potencial para aplicação dessas ferramentas, porém é preciso um esforço de monitoramento conjunto dos parâmetros modelados para obter a quantidade necessária de dados necessários à boa calibração e validação, o que, consequentemente, demandaria recursos adicionais. O cenário ideal para empregá-las seria em praias bastante frequentadas num determinado período do ano, sendo a principal fonte de poluição identificada como difusa, consequente do escoamento de drenagem. A fim de melhorar seu desempenho, é possível empregar outras variáveis ambientais além de níveis de precipitação, como por exemplo, a turbidez, a vazão e o nível dos rios, desde que sejam monitorados sistematicamente junto com as condições de balneabilidade. / This study was focused on the recreational water quality at two beaches located on rivers in the State of São Paulo, Brazil Balneário Reino das Águas Claras at Piracuama River (City of Pindamonhangaba, UGRHI 2) and Cachoeira das Emas at Mogi-Guacú River (City of Pirassununga, UGRHI 9) in order to correlate concentration levels of faecal indicators in water with rainfall levels near the beach and upstream in the watershed. The main objective was the development and evaluation of predictive tools for bathing water conditions, seeking to analyze and compare the results obtained for both beaches considered in the study. These tools are based on rain threshold levels and statistical models, which methodologies are described mainly in studies published by the United States Environmental Protection Agency (USEPA) and the United States Geological Survey (USGS). Data used were collected from the monitoring networks of the State of São Paulo environmental agency (CETESB) and department of water and energy (DAEE), from 2009 to 2012. At each beach, predictive tools were developed for the dry season (April to September) and the rainy season (October to March), based on levels of accumulated rainfall in 24, 48 and 72 hours significantly correlated with concentrations of faecal indicators in water. Model development considered a validation period (year of 2012) independent from the calibration period (2009-2011). Predictive tools developed for the Cachoeira das Emas were more complex than those for the Balneário Reino das Águas Claras, because the beach is inserted into a larger watershed and its regression models considered data from various rainfall stations. The significant correlations (p value<0,05) observed between concentrations of faecal indicators in water and accumulated levels of rainfall were positive for both beaches. Because the monitoring networks have different objectives, not all rainfall events that occurred during the period of the study were related to a concentration value of faecal indicator in the water, as microbiological results paired with null or insignificant levels of precipitation were not considered, precisely because the predictive tools are based on rainfall. The different tools developed showed varying levels of specificity and sensitivity, i.e., the ability to correctly predict good and bad conditions of bathing. The conclusion is that there is a potential for application of predictive tools, however, additional effort is required on monitoring systematically the models parameters in order to obtain the necessary amount of data to achieve a good calibration and validation of the models; consequently, additional resources are required. The ideal scenario would be using the model during a certain period of the year, at beaches quite frequented, for which diffuse pollution is the main contribution, such as the drainage runoff. Aiming to improve the performance of this type of tool, one can also employ other environmental variables besides precipitation levels, such as turbidity, flow rate and river level, as long as these parameters are systematically monitored with the bathing water conditions.