El estrés oxidativo es una consecuencia directa del necesario consumo de oxígeno por parte de los organismos vivos aerobios, y su intensidad y consecuencias dependen de la capacidad de nuestros sistemas de defensa específicos para contrarrestar las especies reactivas del oxígeno (ERO) generadas, entre las cuales destacan los radicales libres del oxígeno (RLO). Numerosas circunstancias, fisiológicas o patológicas, pueden incrementar la producción de RLO y, por tanto, aumentar el estrés oxidativo. Entre ellas está la radiación UV (RUV), a la que todos nosotros estamos expuestos con mayor o menor intensidad y asiduidad.La exposición a la RUV es causa de numerosas alteraciones cutáneas, incluido el cáncer de piel. El progresivo aumento de este tipo de cáncer en las últimas décadas ha suscitado una gran preocupación sanitaria y social, por lo cual todos los aspectos relacionados con la fotoprotección son objeto de investigación desde diversos puntos de vista: físico, químico, biológico y sanitario.En este sentido, no cabe duda de que actualmente disponemos de una información muy valiosa acerca de los riesgos de la exposición a la RUV y, al mismo tiempo, existen fotoprotectores muy eficaces y desarrollados con criterios científicos avanzados. No obstante, y a pesar de que el consumo de fotoprotectores no cesa de incrementarse, la incidencia del cáncer de piel sigue aumentando. Con este trabajo pretendemos llamar la atención sobre la falsa sensación de seguridad que puede derivarse del uso incorrecto de fotoprotectores y sobre la necesidad de revisar en profundidad algunos de los conceptos sobre los que se basa la fotoprotección.En consecuencia, en el protocolo experimental desarrollado, se irradiaron lotes de animales (ratas hairless) de forma aguda, crónica o bien tratados con filtros solares. Y se determinaron parámetros bioquímicos reflejo de los radicales libres tanto en sangre como en epidermis. También se determinó el daño producido sobre el material genético, y el número y capacidad funcional de las células inmunitarias de la piel (células de Langerhans). Las principales conclusiones que se derivan de este trabajo son las siguientes:1. La RUV, a partir de dosis equivalentes a 1 DEM (dosis eritemógena mínima), induce cambios sistémicos y cutáneos en los sistemas de defensa específicos frente al estrés oxidativo, simultáneamente a la pérdida de la inmunidad cutánea.2. Dosis suberitemógenas y repetidas de RUV, asimilables a las que recibe una persona sometida a exposiciones moderadas al sol, también determinan pérdida de la inmunidad cutánea y alteraciones indicativas de desequilibrio oxidativo.3. El número de células de Langerhans de la epidermis se correlaciona con diversos parámetros sanguíneos y epidérmicos relacionados con el estrés oxidativo. El hecho de que la actividad de la glutatión peroxidasa y la concentración de glutatión reducido eritrocitarios sean predictores del número de células de Langerhans, sugiere la posibilidad de que dichos parámetros constituyan una alternativa válida para evaluar indirectamente la capacidad inmunitaria cutánea.4. La determinación del factor de protección solar, basado exclusivamente en la capacidad de prevención del eritema, no ofrece las garantías necesarias para una fotoprotección segura frente a la RUV. Es necesario adoptar nuevos criterios de fotoprotección, basados en indicadores más sensibles y precoces que el eritema.5. Los valores del factor de protección solar que presentan los fotoprotectores actuales deben someterse a un juicio crítico. En este sentido, sería prudente reducir dichos valores a la mitad o a la tercera parte.6. Puesto que muchos de los efectos de la RUV derivan del estrés oxidativo, es muy recomendable desarrollar nuevas fórmulas fotoprotectoras que incluyan principios activos capaces de restaurar el equilibrio oxidativo y de neutralizar los efectos de los radicales libres. / The oxidative stress is a direct consequence of the necessary consumption of oxygen by the living aerobic organisms, and its intensity and consequences depend on the capacity of specific defence systems to counteract the generated reactive oxygen species (ROS), among which the most relevant are the oxygen free radicals (OFR). Numerous circumstances, physiological or pathological, can increase the production of OFR and, therefore, increase the oxidative stress. Among them there is the UV radiation (UVR), to which we are all exposed with greater or smaller intensity and frequency. Exposition to UVR cause numerous cutaneous alterations, included the skin cancer. The progressive increase of this type of cancer in the last decades provoke a great social and sanitary concern; in consequence all the aspects related to photoprotection are object of investigation from different points of view: physical, chemical, biological and sanitary. In this sense, there is no doubt that at the present we have very valuable information about the risks of the exposition to the UVR and, at the same time, there are very efficient sunscreens, which are developed with advanced scientific criteria. Nevertheless, and in spite of the fact that the consumption of sunscreens increases day by day, the incidence of skin cancer increases continuously. With this work we intend to point out the false sensation of security that can be derived from the incorrect use of sunscreens and the need of a depth revision about some of the concepts which photoprotecction is based. Consequently, in the development of experimental protocols, we irradiated groups of animals (hairless rats) in the following way: acute radiations, chronic radiations and radiations with sunscreens. Different biochemical parameters related to OFR were determined in blood and in epidermis. The damage produced on the genetic material, and the number and functional capacity of the immune cells of the skin (Langerhans cells) were also evaluated. The main conclusions derived from this work are the following:1. UVR, from equivalent dose to 1 MED (minimal erithemal dose), induces systemic and cutaneous changes in the specific defence systems in front of oxidative stress, simultaneously to the loose of the cutaneous immunity. 2. Suberithemal and repeated doses of UVR, similar to the received by a person exposed to moderate sun exposure, also determine the lost of the cutaneous immunity and produce oxidative stress relative alterations.3. The number of epidermal Langerhans cells correlates with diverse blood and epidermal parameters related to oxidative stress. The fact that the eritrocytari activity of GPx and concentration of GSH can be predictors of the number of Langerhans cells, suggests the possibility that these parameters could constitute a valid alternative to indirectly evaluate the cutaneous immune capacity. 4. The evaluation of the sun protection factor (SPF), based exclusively in the capacity of prevention from erithema, does not offer the needed guarantees for a sure photoprotection against the UVR. It is necessary to adopt new criteria of photoprotection, based on premature and more sensitive indicators than the erithema. 5. The values of SPF of the sunscreens should be submitted to a critical judgment. In this sense, would be prudent the reduction of this values to the half or to the third part.Due to the fact that many of the effects of the UVR derive from the oxidative stress, is very recommendable to develop new photoprotective formulations that include capable active principles to restore the oxidative equilibrium and to neutralize the effects of free radicals.

El carcinoma basocel•lular (CBC) és la neoplàsia més freqüent en l’ésser humà. La importància d’aquest tumor rau tant en la gran morbiditat que produeix com en l’enorme despesa sanitària que ocasiona als sistemes de salut de gairebé tot el món. Malgrat que el seu tractament és essencialment quirúrgic, existeixen casos on no està indicat aquest abordatge terapèutic i seria interessant el fet de conèixer les alteracions moleculars que comporten la formació de la neoplàsia per tal d’establir possibles dianes farmacològiques. Per aquestes raons hem cregut convenient aprofundir en l’estudi d’aquest tumor, centrant-nos en la fisiopatologia i intentant cultivant-lo “in vitro”. A través de l’estudi de la síndrome de Gorlin-Goltz s’ha establert la importància de la via Sonic hedgehog (Shh) en la fisopatologia del CBC. Nosaltres, mitjançant tècniques com l’immunoblot i la immunohistoquímica (mesurant els nivells de proteïna Gli1) hem determinat que aquesta via està activada en aproximadament la meitat dels casos de CBC esporàdic, confirmant les dades que es coneixen sobre aquest tema. Analitzant vies alternatives, hem trobat mostres amb alta activitat de b-catenina sense afectació de la via Shh i això ens fa pensar que la via Wnt pot tenir un paper fonamental en aquests casos. Hem detectat per immunoblot l’acumulació de b-catenina en la meitat dels casos estudiats, relacionat-se de forma directa amb l’activitat proliferativa de la neoplasia. / El carcinoma basocelular (CBC) es la neoplasia más frecuente en el ser humano. La importancia de este tumor radica tanto en la gran morbilidad que produce como en el enorme gasto sanitario que ocasiona a los sistemas de salud de casi todo el mundo. A pesar de que su tratamiento es esencialmente quirúrgico, existen casos donde no está indicado este abordaje terapéutico y sería interesante el hecho de conocer las alteraciones moleculares que comportan la formación la neoplasia para establecer posibles dianas farmacológicas. Por estas razones hemos creído conveniente profundizar en el estudio de este tumor, centrándonos en la fisiopatología e intentando su cultivo “in vitro”. A través del estudio del síndrome de Gorlin-Goltz se ha establecido la importancia de la via Sonic hedgehog (Shh) en la fisiopatología del CBC. Nosotros, mediante técnicas como el inmunoblot y la inmunohistoquímica (midiendo los niveles de proteína Gli1) hemos determinado que esta vía está activada en aproximadamente la mitad de los casos de CBC esporádico, confirmando los datos que se conocían sobre este tema. Analizando vías alternativas, hemos encontrado muestras con alta actividad de b-catenina sin afectación de la vía Shh y esto nos hace pensar que la vía Wnt puede tener un papel fundamental en estos casos. Hemos detectado por inmunoblot la acumulación de b-catenina en la mitad de los casos estudiados, relacionándose de forma directa con la actividad proliferativa de la neoplasia. / Basal cell carcinoma (BCC) is the most common malignancy in humans. The importance of this tumor lies both in the high morbidity produced as in the high costs caused to the health systems of whole world. Although its treatment is essentially surgical, there are cases where it is not indicated this therapeutic approach, then it would be interesting to know the molecular alterations that involve the formation of this neoplasm to establish potential drug targets.For these reasons we have decided to study this tumor, focusing on the physiopathology and their culture "in vitro". Through the study of Gorlin-Goltz syndrome, the importance of the Sonic hedgehog pathway (Shh) in the pathophysiology of BCC was well established. Using techniques such as immunoblotting and immunohistochemistry (measuring protein levels Gli1), we have determined that this pathway is activated in about half of cases of sporadic BCC, confirming the previously known data. Analyzing alternative pathways, we found samples with high activity of b-catenin pathway without affecting Shh. This fact makes us think that the Wnt pathway may have a important role in these cases. We detected by immunoblot the accumulation b-catenin in half of the cases studied, interacting directly with the proliferative activity of the neoplasm.

Objective: To determine the prevalence of the lower third molar position according to the classification of Winter and the classification of Pell and Gregory in patients between 18-35 years of age of the Universidad Peruana de Ciencias Aplicadas Dental Clinic during the period from February 2011 to December 2012. Material and methods: This is an observational, descriptive, transversal and retrospective study in which 582 panoramic x-rays were selected of the clinical record of patients that were found in the range of age required and in the establish period of time. Results: 1067 lower third molars were evaluated. According to the study it was observed that the most prevalent positions, according to the classification of Winter were vertical (42, 3 %) and mesioangular (31, 4 %), for both male and female and in both sides for patients between 18 and 35 years. According to the classification of Pell and Gregory, the most prevalent position was IA (39 %) for both genders and in both sides for patients between 18 and 35 years too. Conclusions: According to the classification of Winter the most prevalent positions were the vertical and mesioangular. According to the classification of Pell and Gregory, it was IA. It was also found that those positions were the most frequent in both genders and in both sides for patients between 18 and 35 years. / Objetivo: Determinar la prevalencia de la posición de las terceras molares mandibulares según la clasificación de Winter y según la clasificación de Pell y Gregory en pacientes de 18 a 35 años de la clínica odontológica docente de la Universidad Peruana de Ciencias Aplicadas durante el periodo febrero 2011-diciembre 2012. Materiales y métodos: Se trata de un estudio observacional, descriptivo, transversal y retrospectivo en el cual se seleccionaron 582 radiografías panorámicas de las historias clínicas de los pacientes de la clínica docente que se encontraban en el rango de edad requerido y en el periodo establecido. Resultados: Se evaluaron en total 1067 terceras molares mandibulares. De acuerdo al análisis, se observó que las posiciones más prevalentes según la clasificación de Winter fueron vertical (42,3 %) y mesioangulada (31,4 %), ambas posiciones para ambos géneros y lados entre los 18 y 35 años. Según la clasificación de Pell y Gregory, la posición más prevalente fue la IA (39 %) también la posición más frecuente para ambos géneros y lados, entre los 18 y 35 años. Conclusiones: De acuerdo a la clasificación de Winter, las posiciones más prevalentes fueron la vertical y la mesioangulada y, según la clasificación de Pell y Gregory fue la IA. Además, en ambas clasificaciones se determinó que dichas posiciones fueron las más frecuentes en ambos géneros y lados, entre los 18 y 35 años. Palabras clave: Terceras molares, impactación, inclusión, retención, clasificación de Winter, clasificación de Pell y Gregory

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Community college students often have more complex needs and access to fewer resources than their four-year university counterparts. While there is some research on community colleges, it tends to be narrowly focused on students' initial degree aspirations, previous academic record, and demographic characteristics and less on the students’ experiences and perceptions. This dissertation identifies and illuminates the gaps between the existing research and the perceptions of community college students. This research draws on empowerment theory and the theory of democratization and diversion to comprehensively explore the complexities of community college students' lives. In-depth qualitative interviews were conducted with two groups of current Pell Grant eligible community college students: 1) those who meet their institution's criteria for satisfactory academic progress towards an Associates in Arts degree (n=31); and 2) those who do not meet the criteria (n=31). The purpose of these interviews was to uncover barriers and enablers contributing to students' abilities to meet their educational goals. Braun & Clarke's (2006) six phases of iterative thematic analysis were followed to analyze the data and ATLAS.ti software was used to assist in the coding. The data were grouped so that the overlapping experiences of participants could be clearly noted without losing the unique perceptions and words of the participants. Four major themes were identified: sources of motivation; responsibilities to resources ratio and external barriers; informational capital and knowledge; and powerlessness. Motivation and access to sufficient resources in order to meet a student's responsibilities were noted by participants as requirements to enable educational attainment. Additionally, the need for students to decode the rules of higher education in the institution and classroom were identified, and different levels of powerlessness were noted between groups. These findings have implications for theory including updating Brint & Karabel's democratization and diversion theory and presenting an emerging theoretical construct. Recommendations for policy and practice are made. Further, areas of further exploration for community college students and employees are presented in order to continue to add these expert voices in to the larger community college conversation.

Thesis advisor: Andrés Castro Samayoa / The involvement of colleges and universities in the provision of higher education opportunities in prison has reemerged after a long pause following the 1994 Omnibus Crime Bill, which effectively ended the majority of postsecondary prison education programs. The 2016 Second Chance Pell Program has been instrumental in the development and expansion of higher education opportunities in prison. Support for justice reform measures has led to the likely full restoration of Pell Grant availability in prisons, taking effect as early as 2023, with funding for the initiative included in the most recent congressional stimulus bill. Both Second Chance Pell and one of the most progressive state-level prison education policies, New York’s Right Priorities initiative, rely almost exclusively on positioning higher education in prison as a tool for meeting the market needs of the state: reduced recidivism equating to taxpayer savings. This dissertation extends prior research examining the pitfalls of justifications overly reliant on narratives of recidivism. Using a three-article approach, it explores justifications capable of articulating the full moral vigor necessary to sustain long-term commitments to such policies and programs, ones that prioritize humanized responses to incarceration. The first article amplifies justifications articulated by those who have been the beneficiaries of such educational opportunities, investigating formerly incarcerated student perspectives on the value, meaning, and purpose of such programs. The second article, by focusing on policy developments within the state of New York, examines how the rhetoric of recidivism emerges in media coverage of both federal and state level support for college-level prison education. And, finally, the third article considers the pedagogical implications of adjusting the lens through which programs are defended, exploring the use of andragogical teaching methods—those associated with the tenets of adult education—in the context of prison classrooms. Taken together, each study contributes to literatures examining justifications for higher education in prison, and develops deeper understandings of the need for the provision of such opportunities. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-28T15:03:54Z No. of bitstreams: 1 Danilo Albuquerque de Campos.pdf: 453917 bytes, checksum: 1b07ec11128857b2e96af37543e335fe (MD5) / Made available in DSpace on 2017-03-28T15:03:55Z (GMT). No. of bitstreams: 1 Danilo Albuquerque de Campos.pdf: 453917 bytes, checksum: 1b07ec11128857b2e96af37543e335fe (MD5) Previous issue date: 2014-08-22 / In this work we are interested in showing three algorithms rational approximation of square roots by methods unknown or underutilized by teachers of elementary and secondary education. We begin by defining numerical sequence and convergence of sequences, will discuss the need to expand the concept of rational number and demonstrate the irrationality of the diagonal of a square. Prove an important theorem known in the literature as Dirichlet’s theorem and finally elencaremos three methods of approximating the square roots of natural non-perfect square numbers, very simple to be worked on in the classroom that are rational algorithm aproximção of Hiero of Alexandria, Theon’s Ladder and the Pell-Fermat equation, sende latter discursão fundamental to who will perform on the relationship of the three methods presented. / Neste trabalho estamos interessados em mostrar três algoritmos de aproximação racional de raízes quadradas por métodos pouco utilizados ou desconhecidos pelos professores do ensino fundamental e médio. Iniciaremos definindo sequência numérica e convergência de sequências, discutiremos sobre a necessidade de ampliação do conceito de número racional e demonstraremos a irracionalidade da diagonal de um quadrado. Provaremos um importante Teorema conhecido na literatura como o Teorema de Dirichlet, e por fim elencaremos três métodos de aproximação de raízes quadradas de números naturais não quadrados perfeitos, muito simples de serem trabalhados em sala de aula que são: O algoritmo de aproximação racional de Hierão de Alexandria, A escada de Theon e a Equação de Pell-Fermat, sendo este último fundamental para discussão que iremos realizar sobre a relação dos três métodos apresentados.

Using Bean and Metzner's conceptual framework related to non-traditional student attrition, the responsible use of Federal Pell Grants was studied by examining the retention and academic performance of college-credit seeking students in a public college in Florida that predominantly offered two year degree programs. Also analyzed were differences between Pell Grant recipients and non-recipients among various demographic categories. Chi-square tests of independence indicated that statistical significance existed between Pell Grant recipients and non-recipients in retention rates from fall to spring terms, as well as in the demographic variables of academic performance, gender, ethnicity, age group, residency, and credit hours achieved. Only the variable of ethnicity showed a medium practical effect size, with all the other variables indicating a small to no practical effect size.