Conselho Nacional de Desenvolvimento Científico e Tecnológico / Endocrine Disrupter Compounds (EDCs) like pesticides, alkylphenols and hormones among other classes of compounds are responsible for alterations in the endocrine system functions. Endocrine disruption occurs when EDCs interact with the hormone receptors, altering the natural response patterns of the endocrine system. Aquatic organisms, such as fish, are able to accumulate EDCs residues in concentration several times higher than the surrounding water. Consequently, fish is a major source of contamination for both top predators and human consumers. This study aimed to develop and validate a fast method for the determination of 40 endocrine disrupters in fish fillet, using modified QuEChERS and Gas Chromatography coupled with Mass Spectrometry in tandem, using a triple quadrupole analyzer (GC-(TQ)MS/MS). A factorial design was performed to optimize the extraction procedure, which consist of the extraction of 10.0 g of fish fillet with 10.0 mL of acetonitrile with 1% (v/v) of acetic acid followed by manual shaking for 1 min. In the partition step 2.0 g of sodium chloride, 1.7 g of anhydrous sodium acetate and 0.3 g of anhydrous magnesium sulfate were added, followed by shaking and centrifugation at 3400 rpm for 8 min. Then the extract was transferred to a 15 mL polypropylene tube containing the C18 and PSA sorbents, beyond the anhydrous magnesium sulfate. After shaking and centrifuging, the supernatant was filtered and analyzed by GC-(TQ)MS/MS. The method was validated by spiking the blank sample at three concentration levels (10, 25 and 50 Ug kg-1) obtaining recovery values between 70.1 to 120.0% for 36 of the 40 endocrine disrupters evaluated. RSD values below 20% ensured the good precision of the method. The linearity was evaluated using the coefficient of determination (r2) with values higher than 0.996 for all compounds. The matrix effect was evaluated, and it was pretty intense for most compounds, with values exceeding 10%. This effect was compensated using analytical curves obtained with standards prepared in blank matrix extracts. This method was applied in 6 samples of fish fillet from different species. Residues of bisphenol A, chlorpyrifos and bifenthrin were detected. Therefore, the modified QuEChERS method proved to be appropriated for the determination of endocrine disrupters in fish fillet using GC-(TQ)MS/MS since it showed to be effective and can be applied to routine analysis. / Compostos conhecidos como disruptores endócrinos (DEs), tais como agrotóxicos, alquilfenóis, hormônios, dentre outras classes de substâncias são responsáveis pela alteração de funções do sistema endócrino. Esse efeito ocorre quando os DEs interagem com os receptores hormonais, alterando os padrões de resposta natural do sistema endócrimo. Os organismos aquáticos, como os peixes são capazes de acumular concentrações de DEs várias vezes superiores a água ao seu redor. Consequentemente, os peixes são uma importante fonte de contaminação para seus predadores e consumidores humanos. O presente trabalho teve como objetivo desenvolver e validar um método rápido para a determinação de 40 disruptores endócrinos em filé de peixe (jundiá), utilizando QuEChERS modificado e Cromatografia Gasosa acoplada à Espectrometria de Massas em série, empregando analisador triplo quadrupolo (GC-(TQ)MS/MS). Utilizou-se do planejamento fatorial em estrela para otimização do procedimento de extração, o qual consiste da extração de 10,0 g de filé de peixe com 10,0 mL de acetonitrila/1% (v/v) ácido acético seguido de agitação manual por 1 min. Na etapa de partição adicionou-se 2,0 g de cloreto de sódio, 1,7 g de acetato de sódio anidro e 0,3 g de sulfato de magnésio anidro. Realizou-se agitação por 1 min e centrifugação a 3400 rpm por 8 min. Em seguida, o extrato foi transferido para um tubo de polipropileno de 15 mL contendo os sorventes C18 e PSA, além de sulfato de magnésio anidro. Foi realizada a agitação manual e centrifugação, o extrato foi filtrado e analisado por GC-(TQ)MS/MS. O método foi validado fortificando a amostra branco em três níveis de concentração (10, 25 e 50 Ug kg-1) obtendo valores de recuperação entre 70,1 e 120,0% para 36 dos 40 disruptores endócrinos avaliados. Valores de RSD inferiores a 20% garantiram a boa precisão do método. A linearidade foi avaliada utilizando o coeficiente de determinação (r2) sendo este maior que 0,996 para todos os compostos. O efeito matriz foi avaliado, o qual foi bastante intenso para a maioria dos compostos, com valores superiores a 10%. O efeito matriz foi compensado utilizando-se curvas analíticas preparadas no extrato branco da matriz. A aplicação do método foi realizada em 6 amostras de filé de peixe de diferentes espécies, nas quais resíduos de bisfenol A, clorpirifós etílico e bifentrina foram encontrados. O método QuEChERS modificado proposto para a determinação de disruptores endócrinos em filé de peixe utilizando GC-(TQ)MS/MS mostrou ser eficaz, podendo ser aplicado em análise de rotina.

One electron oxidation of DNA has been studied extensively over the years. When a charge is injected into a DNA duplex, it migrates through the DNA until it reaches a trap. Upon further reactions, damage occurs in this area and strand cleavage can occur. Many works have been performed to see what can affect this damage to DNA. Netropsin is a minor groove binder that can bind to tracts of four to five A:T base pairs. It has been used in the studies within to determine if it can protect DNA against oxidative damage, caused by one-electron oxidation, when it is bound within the minor groove of the DNA. By using a naphthacenedione derivative as a photosensitizer, several DNA duplexes containing netropsin binding sites as well as those without binding sites, were irradiated at 420 nm, analyzed, and visualized to determine its effect on oxidative damage. It has been determined netropsin creates a quenching sphere of an average of 5.8 * 108 Šwhether bound to the DNA or not. Herein we will show netropsin protects DNA against oxidative damage whether it is free in solutions or bound within the minor groove of a DNA duplex.

The United States public schools promote inclusion and educational equity among diverse student populations. Considerable and growing numbers of students with categorical disabilities and Limited English Proficiency (LEP) are enrolled in regular classrooms. The systemic barriers in learning that they have could impact teacher perceptions and decisions about teaching practices as well as the teaching profession. These students have challenged K-12 science, technology, engineering, and mathematics (STEM) teachers to provide high-quality, accommodative service and equitable educational opportunities in an increasingly STEM-infused society. Professional development associated with teaching students with disabilities and LEP is critical to inform in-service STEM teachers with these students' learning needs and promote student success. Effective preparation and support help maintain teacher satisfaction and retention within the teaching profession. However, the levels and perceptions of STEM teacher participation in such professional development, and whether the service load and professional development regarding the concerned groups of students associated with teacher satisfaction and retention remain unclear. This dissertation addresses these issues through two research studies using secondary analysis of the 2011-2012 School and Staffing Survey Teacher Questionnaire (SASS TQ) national dataset. The first study focused on K-12 STEM educator participation and perceived utility regarding their professional development experience concerning students with disabilities and LEP. Quantitative analysis revealed an overall lower level of participation and perceived utility of such professional development for STEM educators compared to all other educators. The second study examined teacher satisfaction and intent to remain in teaching, as well as their relationships to teacher service load and professional development specific to students with disabilities and LEP. Results indicated that K-12 STEM educators were less likely to feel satisfied or intent on remaining in teaching, compared to the remainder of the teaching population. Logistic regressions showed that service load of students with LEP predicted teacher satisfaction and participation in professional development concerning students with disabilities associated with teacher intent to remain in STEM education, especially for science educators. These findings collectively suggested the necessity and demands of sufficient and useful professional development offerings regarding the two concerned groups of students in inclusive STEM education settings. / Ph. D.

Summaries in Afrikaans and English / Die noodsaaklikheip om produktiwiteit en kwaliteit in hoer onderwys te verbeter, het aanleiding gegee tot die relatief nuwe totale kwaliteitbestuur (TQM)-beweging by tersiere onderriginstellings soos universiteite en technikons. Die integrering van die totale kwaliteitverwante konsepte van strategiese TOM -intensie, eksterne omgewingsfaktore, bestuur se reaksie, kwaliteitstelseleffektiwiteit en deurlopende verbetering in 'n model, dui die gekombineerde gevolge van genoemde konsepte op die institusionele verbetering van technikons en • universiteite aan. Die belangrikste veranderlikes (binne bogenoemde dimensies van die model) wat vir institusionele verbetering by onderskeidelik universiteite en technikons verantwoordelik is, toon ooreenstemming - universiteite en technikons verskil egter ten opsigte van ander minder belangrike veranderlikes. Die funksionering van die model is soos volg: Die bestuur (akademies en administratief) van die tersiere onderriginstelling identifiseer en erken, onderhewig aan aspekte soos leierskap, kennis, ervaring, en aanvaarding, sekere eksterne omgewingsfaktore wat verband hou met die klientebehoeftes (ekstern en intern) en institusionele verbetering. Gegewe genoemde beperkings en faktore besluit bestuur op die (suboptimale) strategiese TQM-intensie om aan klientebehoeftes te voldoen. Die strategiese TQM-intensie sal nou saam met bestuur se reaksie (deur die toepassing van die TQM-beginsels en -filosofie) wat die effektiwiteit van die kwaliteitstelsel bepaal, bepaal op watter kwaliteitvlak die instelling sal opereer. Die kwaliteitstelsel bestaan uit die bestuur-, tegniese. en sosiale stelsel, en is weer eens I aan deurlopende verbetering onderhewig. (Die bestuurstelsel dien as integreerder van die ander twee stelsels.) Die eindresultaat van die toepassing van die TQMfilosofie en -beginsels is institusionele verbetering. Verder kan die model en die resultate van hierdie studie deur universiteite en technikons gebruik word by die verbetering/implementering van hulle eie, unieke totale kwaliteitimplementeringsmodel(le) - 'n uitgebreide implementeringsmodel is vir die rede voorgehou. Laastens kan die (verkorte) meetinstrumente wat vir universiteite en technikons onderskeidelik bepaal is, gebruik word om die sukses met die implementering van TQM by 'n individuele instelling te meet. / The necessity to improve productivity and quality in higher education has resulted in the relatively new movement of Total Qua~ity Management(TQM) at tertiary institutions such as universities and technikons. The integration of the total quality-related concepts of_ strategic TQM intent, external environmental factors, reaction of management, effectiveness of the quality system and continuous improvement in a model, can be used to indicate their combined results on the institutional improvement of technikons and universities. The most important variables (within the above-mentioned dimensions of the model) responsible for institutional improvement at universities and technikons respectively, correspond - however, universities and technikons differ regarding the less important variables. The functioning of the model is. as follows: The management (academic and administrative) of the tertiary educational institution identifies and recognises, subject to aspects such as leadership, knowledge, experience and acceptance, certain external environmental factors which are related to the client's requirements (external and internal) and institutional improvement. Given the above restrictions and factors, management decides on the (sub-optimal) strategic TQM intent to satisfy client requirements. The strategic TOM intent together with the reaction of the management (by the application of the TOM principles and philosophy) which determines the effectiveness of the quality system, will determine on which quality level the institution will operate. The quality system comprises the management, technical and social system, and is again subject to continuous improvement. (The management system serves as an integrator of the other two systems). The end result of the application of the TOM philosophy and principles is institutional improvement. The model and results of the study can further be used by universities and technikons for the improvement\implementation of their own, unique, total quality implementation model(s) - for this reason an extended implementation model was presented. Lastly, the (abridged) measuring instruments established for universities and technikons respectively, can be used to measure the success with the implementation of TQM at an individual institution. / Business Management / D.B.L.

Summaries in Afrikaans and English / Die noodsaaklikheip om produktiwiteit en kwaliteit in hoer onderwys te verbeter, het aanleiding gegee tot die relatief nuwe totale kwaliteitbestuur (TQM)-beweging by tersiere onderriginstellings soos universiteite en technikons. Die integrering van die totale kwaliteitverwante konsepte van strategiese TOM -intensie, eksterne omgewingsfaktore, bestuur se reaksie, kwaliteitstelseleffektiwiteit en deurlopende verbetering in 'n model, dui die gekombineerde gevolge van genoemde konsepte op die institusionele verbetering van technikons en • universiteite aan. Die belangrikste veranderlikes (binne bogenoemde dimensies van die model) wat vir institusionele verbetering by onderskeidelik universiteite en technikons verantwoordelik is, toon ooreenstemming - universiteite en technikons verskil egter ten opsigte van ander minder belangrike veranderlikes. Die funksionering van die model is soos volg: Die bestuur (akademies en administratief) van die tersiere onderriginstelling identifiseer en erken, onderhewig aan aspekte soos leierskap, kennis, ervaring, en aanvaarding, sekere eksterne omgewingsfaktore wat verband hou met die klientebehoeftes (ekstern en intern) en institusionele verbetering. Gegewe genoemde beperkings en faktore besluit bestuur op die (suboptimale) strategiese TQM-intensie om aan klientebehoeftes te voldoen. Die strategiese TQM-intensie sal nou saam met bestuur se reaksie (deur die toepassing van die TQM-beginsels en -filosofie) wat die effektiwiteit van die kwaliteitstelsel bepaal, bepaal op watter kwaliteitvlak die instelling sal opereer. Die kwaliteitstelsel bestaan uit die bestuur-, tegniese. en sosiale stelsel, en is weer eens I aan deurlopende verbetering onderhewig. (Die bestuurstelsel dien as integreerder van die ander twee stelsels.) Die eindresultaat van die toepassing van die TQMfilosofie en -beginsels is institusionele verbetering. Verder kan die model en die resultate van hierdie studie deur universiteite en technikons gebruik word by die verbetering/implementering van hulle eie, unieke totale kwaliteitimplementeringsmodel(le) - 'n uitgebreide implementeringsmodel is vir die rede voorgehou. Laastens kan die (verkorte) meetinstrumente wat vir universiteite en technikons onderskeidelik bepaal is, gebruik word om die sukses met die implementering van TQM by 'n individuele instelling te meet. / The necessity to improve productivity and quality in higher education has resulted in the relatively new movement of Total Qua~ity Management(TQM) at tertiary institutions such as universities and technikons. The integration of the total quality-related concepts of_ strategic TQM intent, external environmental factors, reaction of management, effectiveness of the quality system and continuous improvement in a model, can be used to indicate their combined results on the institutional improvement of technikons and universities. The most important variables (within the above-mentioned dimensions of the model) responsible for institutional improvement at universities and technikons respectively, correspond - however, universities and technikons differ regarding the less important variables. The functioning of the model is. as follows: The management (academic and administrative) of the tertiary educational institution identifies and recognises, subject to aspects such as leadership, knowledge, experience and acceptance, certain external environmental factors which are related to the client's requirements (external and internal) and institutional improvement. Given the above restrictions and factors, management decides on the (sub-optimal) strategic TQM intent to satisfy client requirements. The strategic TOM intent together with the reaction of the management (by the application of the TOM principles and philosophy) which determines the effectiveness of the quality system, will determine on which quality level the institution will operate. The quality system comprises the management, technical and social system, and is again subject to continuous improvement. (The management system serves as an integrator of the other two systems). The end result of the application of the TOM philosophy and principles is institutional improvement. The model and results of the study can further be used by universities and technikons for the improvement\implementation of their own, unique, total quality implementation model(s) - for this reason an extended implementation model was presented. Lastly, the (abridged) measuring instruments established for universities and technikons respectively, can be used to measure the success with the implementation of TQM at an individual institution. / Business Management / D.B.L.

Following Toyota's dramatic rise to prominence within the automotive industry in the late 1980's, firms around the globe have widely sought to adopt Lean Six Sigma (LSS) as a means of reducing costs, improving quality, and gaining an overall competitive advantage. While the operational benefits of LSS are largely undisputed, there are criticisms of the movement with regards to its effect on firm innovation capability. Prior academic studies investigating the relationship between LSS and innovation are largely conceptual in nature, rely heavily on qualitative data, and display a high degree of variability in results. The objective of this work was to empirically confirm whether LSS adoption had a positive, negative, or neutral impact on firm innovation performance.Financial data was collected for 151 publicly traded firms over the period from 1985 to 2018. The year of company-wide adoption of LSS was identified for each sample firm. Firms were paired with industry rivals using Coarsened Exact Matching (CEM), and statistical regressions were performed to show correlations between LSS implementation (as measured by inventory turns) and innovation performance (as measured by Total Factor Productivity, Research Quotient, and Tobin's Quotient). Regression results indicated that LSS implementation had a positive correlation with firm process innovation performance and the overall market perception of firm innovation and value, and a negative-to-neutral correlation with firm product innovation performance. Additional regressions performed at the industry-sector level revealed that the LSS-innovation relationship varies greatly by industry environment and is subject to unique industry effects and management implementation decisions.