998 resultados para Personal persistence


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Dissertação de Mestrado apresentada ao Instituto Superior de Psicologia Aplicada para obtenção de grau de Mestre na especialidade de Psicologia Clínica.

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While undergraduate enrollment of all racial groups in United States higher education institutions has increased, 6-year graduation rates of Blacks (39%) remain low compared to other races; Asians (69%), Whites (62%), and Hispanics (50%; NCES, 2010). Women's graduation rate is higher than men's; 58% compared to men's at 53% in public institutions (IPEDS, 2011). Retention literature does not address the perceptions of Black ethnic groups' experiences in college, particularly in Hispanic serving institutions. Informed by Tinto's (1975, 1987, 1993) student academic and social integration model, Guiffrida's (2003, 2004, 2005, 2006) model of relationships while at college, and ex-post facto research design, the study investigated personal and institutional factors that relate to Black students' self-efficacy and persistence to the senior year in college. Data about Black ethnic undergraduate seniors' (N = 236) academic and social experiences in college were collected using the Student Institutional Integration Survey (SIIS), an online questionnaire. Descriptive statistics were used to collect background information about the sample, correlation was calculated to indicate the degree of relationship between the variables, and multiple linear regressions were used to identify variables that are predictors of self-efficacy of persistence. Independent samples t-test and analyses of variance were computed to determine whether differences in perceptions of personal and institutional factors that relate to self-efficacy of persistence to the senior year in college could be identified between gender and ethnicity. Frequency was summarized to identify themes of participants' primary motivation for finishing undergraduate degree programs. These themes were: (a) self-pride/personal goal, (b) professional aspiration/career (c) motivation to support family, (d) desire to have financial independence/better job, (e) to serve community, (f) opportunity to go to college, (g) being first-generation college student, and (h) prove to family the value of higher education. The research findings support the tenets of academic and social integration theories which suggest that students' interaction with peer and faculty, relationships with family and friends, and involvement in institutional activities and organizations influence their persistence in college. Implications based on the findings affect institutional policy, curriculum, and program improvements that relate to Black undergraduate students' academic and social support.

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While undergraduate enrollment of all racial groups in United States higher education institutions has increased, 6-year graduation rates of Blacks (39%) remain low compared to other races; Asians (69%), Whites (62%), and Hispanics (50%; NCES, 2010). Women’s graduation rate is higher than men’s; 58% compared to men’s at 53% in public institutions (IPEDS, 2011). Retention literature does not address the perceptions of Black ethnic groups’ experiences in college, particularly in Hispanic serving institutions. Informed by Tinto’s (1975, 1987, 1993) student academic and social integration model, Guiffrida’s (2003, 2004, 2005, 2006) model of relationships while at college, and ex-post facto research design, the study investigated personal and institutional factors that relate to Black students’ self-efficacy and persistence to the senior year in college. Data about Black ethnic undergraduate seniors’ (N = 236) academic and social experiences in college were collected using the Student Institutional Integration Survey (SIIS), an online questionnaire. Descriptive statistics were used to collect background information about the sample, correlation was calculated to indicate the degree of relationship between the variables, and multiple linear regressions were used to identify variables that are predictors of self-efficacy of persistence. Independent samples t-test and analyses of variance were computed to determine whether differences in perceptions of personal and institutional factors that relate to self-efficacy of persistence to the senior year in college could be identified between gender and ethnicity. Frequency was summarized to identify themes of participants’ primary motivation for finishing undergraduate degree programs. These themes were: (a) self-pride/personal goal, (b) professional aspiration/career (c) motivation to support family, (d) desire to have financial independence/better job, (e) to serve community, (f) opportunity to go to college, (g) being first-generation college student, and (h) prove to family the value of higher education. The research findings support the tenets of academic and social integration theories which suggest that students’ interaction with peer and faculty, relationships with family and friends, and involvement in institutional activities and organizations influence their persistence in college. Implications based on the findings affect institutional policy, curriculum, and program improvements that relate to Black undergraduate students’ academic and social support.

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Traditional classrooms have been often regarded as closed spaces within which experimentation, discussion and exploration of ideas occur. Professors have been used to being able to express ideas frankly, and occasionally rashly while discussions are ephemeral and conventional student work is submitted, graded and often shredded. However, digital tools have transformed the nature of privacy. As we move towards the creation of life-long archives of our personal learning, we collect material created in various 'classrooms'. Some of these are public, and open, but others were created within 'circles of trust' with expectations of privacy and anonymity by learners. Taking the Creative Commons license as a starting point, this paper looks at what rights and expectations of privacy exist in learning environments? What methods might we use to define a 'privacy license' for learning? How should the privacy rights of learners be balanced with the need to encourage open learning and with the creation of eportfolios as evidence of learning? How might we define different learning spaces and the privacy rights associated with them? Which class activities are 'private' and closed to the class, which are open and what lies between? A limited set of set of metrics or zones is proposed, along the axes of private-public, anonymous-attributable and non-commercial-commercial to define learning spaces and the digital footprints created within them. The application of these not only to the artefacts which reflect learning, but to the learning spaces, and indeed to digital media more broadly are explored. The possibility that these might inform not only teaching practice but also grading rubrics in disciplines where public engagement is required will also be explored, along with the need for consideration by educational institutions of the data rights of students.

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Human parvovirus B19 is a minute ssDNA virus causing a wide variety of diseases, including erythema infectiosum, arthropathy, anemias, and fetal death. After primary infection, genomic DNA of B19 has been shown to persist in solid tissues of not only symptomatic but also of constitutionally healthy, immunocompetent individuals. In this thesis, the viral DNA was shown to persist as an apparently intact molecule of full length, and without persistence-specific mutations. Thus, although the mere presence of B19 DNA in tissue can not be used as a diagnostic criterion, a possible role in the pathogenesis of diseases e.g. through mRNA or protein production can not be excluded. The molecular mechanism, the host-cell type and the possible clinical significance of B19 DNA tissue persistence are yet to be elucidated. In the beginning of this work, the B19 genomic sequence was considered highly conserved. However, new variants were found: V9 was detected in 1998 in France, in serum of a child with aplastic crisis. This variant differed from the prototypic B19 sequences by ~10 %. In 2002 we found, persisting in skin of constitutionally healthy humans, DNA of another novel B19 variant, LaLi. Genetically this variant differed from both the prototypic sequences and the variant V9 also by ~10%. Simultaneously, B19 isolates with DNA sequences similar to LaLi were introduced by two other groups, in the USA and France. Based on phylogeny, a classification scheme based on three genotypes (B19 types 1-3) was proposed. Although the B19 virus is mainly transmitted via the respiratory route, blood and plasma-derived products contaminated with high levels of B19 DNA have also been shown to be infectious. The European Pharmacopoeia stipulates that, in Europe, from the beginning of 2004, plasma pools for manufacture must contain less than 104 IU/ml of B19 DNA. Quantitative PCR screening is therefore a prerequisite for restriction of the B19 DNA load and obtaining of safe plasma products. Due to the DNA sequence variation among the three B19 genotypes, however, B19 PCR methods might fail to detect the new variants. We therefore examined the suitability of the two commercially available quantitative B19 PCR tests, LightCycler-Parvovirus B19 quantification kit (Roche Diagnostics) and RealArt Parvo B19 LC PCR (Artus), for detection, quantification and differentiation of the three B19 types known, including B19 types 2 and 3. The former method was highly sensitive for detection of the B19 prototype but was not suitable for detection of types 2 and 3. The latter method detected and differentiated all three B19 virus types. However, one of the two type-3 strains was detected at a lower sensitivity. Then, we assessed the prevalence of the three B19 virus types among Finnish blood donors, by screening pooled plasma samples derived from >140 000 blood-donor units: none of the pools contained detectable levels of B19 virus types 2 or 3. According to the results of other groups, B19 type 2 was absent also among Danish blood-donors, and extremely rare among symptomatic European patients. B19 type 3 has been encountered endemically in Ghana and (apparently) in Brazil, and sporadical cases have been detected in France and the UK. We next examined the biological characteristics of these virus types. The p6 promoter regions of virus types 1-3 were cloned in front of a reporter gene, the constructs were transfected into different cell lines, and the promoter activities were measured. As a result, we found that the activities of the three p6 promoters, although differing in sequence by >20%, were of equal strength, and most active in B19-permissive cells. Furthermore, the infectivity of the three B19 types was examined in two B19-permissive cell lines. RT-PCR revealed synthesis of spliced B19 mRNAs, and immunofluorescence verified the production of NS1 and VP proteins in the infected cells. These experiments suggested similar host-cell tropism and showed that the three virus types are strains of the same species, i.e. human parvovirus B19. Last but not least, the sera from subjects infected in the past either with B19 type 1 or type 2 (as evidenced by tissue persistence of the respective DNAs), revealed in VP1/2- and VP2-EIAs a 100 % cross-reactivity between virus types 1 and 2. These results, together with similar studies by others, indicate that the three B19 genotypes constitute a single serotype.

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People saving in mutual funds often look at historical performance before they decide which funds to invest in. The implicit assumption made is that superior performance is likely to be repeated in the future. The findings presented in this study, which investigates funds sold on the Swedish market, support such an approach provided that the time horizons are limited to one year. International stock funds that have performed strongly one year are likely to outperform their peers also the following years. But if the historical and future time horizons are extended to two or three years, the positive relationship between past and future performance vanishes in most cases. Persistence tests focusing on the aggregated performance of fund companies were also carried out. These tests produced results rather similar to those on the individual fund level.

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Symptomless nasopharyngeal carriage of Streptococcus pneumoniae (pneumococcus) is very common in young children. Occasionally the carriage proceeds into mild mucosal diseases, such as sinusitis or acute otitis media, or into serious life-threatening diseases, such as pneumonia, sepsis or meningitis. Each year, up to one million children less than five years of age worldwide die of invasive pneumococcal diseases (IPD). Especially in the low-income countries IPD is a leading health problem in infants; 75% of all IPD cases occur before one year of age. This stresses the need of increased protection against pneumococcus in infancy. Anti-pneumococcal antibodies form an important component in the defence against pneumococcal infection. Maternal immunisation and early infant immunisation are two possible ways by which potentially protective antibody concentrations against pneumococci could be achieved in early infancy. The aim of this thesis is to increase the knowledge of antibody mediated protection against pneumococcal disease in infants and young children. We investigated the transfer of maternal anti-pneumococcal antibodies from Filipino mothers to their infants, the persistence of the transferred antibodies in the infants, the immunogenicity of the 23-valent pneumococcal polysaccharide vaccine (PPV) in infants and the response of the children to a second dose of PPV at three years of age. We also investigated the development of antibodies to pneumococcal protein antigens in relation to culture-confirmed pneumococcal carriage in infants. Serum samples were collected from the mothers, the umbilical cords and from the infants at young age as well as at three years of age. The samples were used to determine the antibody concentrations to pneumococcal serotypes 1, 5, 6B, 14, 18C and 19F, as well as to the pneumococcal proteins PspA, PsaA, Ply, PspC, PhtD, PhtDC and LytC by the enzyme immunoassay. The findings of the present study confirm previously obtained results and add to the global knowledge of responses to PPV in young children. Immunising pregnant women with PPV provides the infants with increased concentrations of pneumococcal polysaccharide antibodies. Of the six serotypes examined, serotypes 1 and 5 were immunogenic already in infants. At three years of age, the children responded well to the second dose of PPV suggesting that maternal and early infant immunisations might not induce hyporesponsiveness to polysaccharide antigens after subsequent immunisations. The anti-protein antibody findings provide useful information for the development of pneumococcal protein vaccines. All six proteins studied were immunogenic in infancy and the development of anti-protein antibodies started early in life in relation to pneumococcal carriage.

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Using Tinto's (1987) social integration theory as a framework, this study measured student satisfaction in six transformative areas: educational experience, skills development, faculty interaction, personal growth, sense of community, and overall expectations. Emerging as a strategic planning process priority, this project sought to identify those areas where students succeeded or were at risk. Employing a three-phase mixed methods approach, this descriptive, longitudinal study was conducted from 1990-2004 at a highly selective specialized college and assisted college administrators in developing or modifying programs that would enhance student satisfaction to ensure degree completion.

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The high concentration of underprepared students in community colleges presents a challenge to educators, policy-makers, and researchers. All have pointed to low completion rates and caution that institutional practices and policy ought to focus on improving retention and graduation rates. However, a multitude of inhibiting factors limits the educational opportunities of underprepared community college students. Using Tinto's (1993) and Astin's (1999) models of student departure as the primary theoretical framework, as well as faculty mentoring as a strategy to impact student performance and retention, the purpose of this study was to determine whether a mentoring program designed to promote greater student-faculty interactions with underprepared community college students is predictive of higher retention for such students. While many studies have documented the positive effects of faculty mentoring with 4-year university students, very few have examined faculty mentoring with underprepared community college students (Campbell and Campbell, 1997; Nora & Crisp, 2007). In this study, the content of student-faculty interactions captured during the mentoring experience was operationalized into eight domains. Faculty members used a log to record their interactions with students. During interactions they tried to help students develop study skills, set goals, and manage their time. They also provided counseling, gave encouragement, nurtured confidence, secured financial aid/grants/scholarships, and helped students navigate their first semester at college. Logistic regression results showed that both frequency and content of faculty interactions were important predictors of retention. Students with high levels of faculty interactions in the area of educational planning and personal/family concerns were more likely to persist. Those with high levels of interactions in time-management and academic concerns were less likely to persist. Interactions that focused on students' poor grades, unpreparedness for class, or excessive absences were predictive of dropping out. Those that focused on developing a program of study, creating a road map to completion, or students' self-perceptions, feelings of self-efficacy, and personal control were predictive of persistence.

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Siloxanes are widely used in personal care and industrial products due to their low surface tension, thermal stability, antimicrobial and hydrophobic properties, among other characteristics. Volatile methyl siloxanes (VMS) have been detected both in landfill gas and biogas from anaerobic digesters at wastewater treatment plants. As a result, they are released to gas phase during waste decomposition and wastewater treatment. During transformation processes of digester or landfill gas to energy, siloxanes are converted to silicon oxides, leaving abrasive deposits on engine components. These deposits cause increased maintenance costs and in some cases complete engine overhauls become necessary. The objectives of this study were to compare the VMS types and levels present in biogas generated in the anaerobic digesters and landfills and evaluate the energetics of siloxane transformations under anaerobic conditions. Siloxane emissions, resulting from disposal of silicone-based materials, are expected to increase by 29% within the next 10 years. Estimated concentrations and the risk factors of exposure to siloxanes were evaluated based on the initial concentrations, partitioning characteristics and persistence. It was determined that D4 has the highest risk factor associated to bioaccumulation in liquid and solid phase, whereas D5 was highest in gas phase. Additionally, as siloxanes are combusted, the particle size range causes them to be potentially hazardous to human health. When inhaled, they may affix onto the alveoli of the lungs and may lead to development of silicosis. Siloxane-based COD-loading was evaluated and determined to be an insignificant factor concerning COD limits in wastewater. Removal of siloxane compounds is recommended prior to land application of biosolids or combustion of biogas. A comparison of estimated costs was made between maintenance practices for removal of siloxane deposits and installation/operation of fixed-bed carbon absorption systems. In the majority of cases, the installation of fixed-bed adsorption systems would not be a feasible option for the sole purpose of siloxane removal. However they may be utilized to remove additional compounds simultaneously.

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The high concentration of underprepared students in community colleges presents a challenge to educators, policy-makers, and researchers. All have pointed to low completion rates and caution that institutional practices and policy ought to focus on improving retention and graduation rates. However, a multitude of inhibiting factors limits the educational opportunities of underprepared community college students. Using Tinto's (1993) and Astin's (1999) models of student departure as the primary theoretical framework, as well as faculty mentoring as a strategy to impact student performance and retention, the purpose of this study was to determine whether a mentoring program designed to promote greater student-faculty interactions with underprepared community college students is predictive of higher retention for such students. While many studies have documented the positive effects of faculty mentoring with 4-year university students, very few have examined faculty mentoring with underprepared community college students (Campbell and Campbell, 1997; Nora & Crisp, 2007). In this study, the content of student-faculty interactions captured during the mentoring experience was operationalized into eight domains. Faculty members used a log to record their interactions with students. During interactions they tried to help students develop study skills, set goals, and manage their time. They also provided counseling, gave encouragement, nurtured confidence, secured financial aid/grants/scholarships, and helped students navigate their first semester at college. Logistic regression results showed that both frequency and content of faculty interactions were important predictors of retention. Students with high levels of faculty interactions in the area of educational planning and personal/family concerns were more likely to persist. Those with high levels of interactions in time-management and academic concerns were less likely to persist. Interactions that focused on students' poor grades, unpreparedness for class, or excessive absences were predictive of dropping out. Those that focused on developing a program of study, creating a road map to completion, or students' self-perceptions, feelings of self-efficacy, and personal control were predictive of persistence.

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Siloxanes are widely used in personal care and industrial products due to their low surface tension, thermal stability, antimicrobial and hydrophobic properties, among other characteristics. Volatile methyl siloxanes (VMS) have been detected both in landfill gas and biogas from anaerobic digesters at wastewater treatment plants. As a result, they are released to gas phase during waste decomposition and wastewater treatment. During transformation processes of digester or landfill gas to energy, siloxanes are converted to silicon oxides, leaving abrasive deposits on engine components. These deposits cause increased maintenance costs and in some cases complete engine overhauls become necessary. ^ The objectives of this study were to compare the VMS types and levels present in biogas generated in the anaerobic digesters and landfills and evaluate the energetics of siloxane transformations under anaerobic conditions. Siloxane emissions, resulting from disposal of silicone-based materials, are expected to increase by 29% within the next 10 years. Estimated concentrations and the risk factors of exposure to siloxanes were evaluated based on the initial concentrations, partitioning characteristics and persistence. It was determined that D4 has the highest risk factor associated to bioaccumulation in liquid and solid phase, whereas D5 was highest in gas phase. Additionally, as siloxanes are combusted, the particle size range causes them to be potentially hazardous to human health. When inhaled, they may affix onto the alveoli of the lungs and may lead to development of silicosis. Siloxane-based COD-loading was evaluated and determined to be an insignificant factor concerning COD limits in wastewater. ^ Removal of siloxane compounds is recommended prior to land application of biosolids or combustion of biogas. A comparison of estimated costs was made between maintenance practices for removal of siloxane deposits and installation/operation of fixed-bed carbon absorption systems. In the majority of cases, the installation of fixed-bed adsorption systems would not be a feasible option for the sole purpose of siloxane removal. However they may be utilized to remove additional compounds simultaneously.^