Chemical and physical pretreatments of microalgal biomass

Non-axenic microalga Chlorella sorokiniana was cultivated in batch cultures, and its total sugar composition was determined. The microalga under study showed a total sugar concentration of 21.44 ± 0.46% (w/w). The effects of freeze-drying, oven-drying, freezing and thawing, chemical and the combination of hydrothermal and chemical pretreatments were evaluated. In the combined pretreatment different concentrations of H2SO4 and reaction times were also optimized. It was possible to determine that the sugar extraction yields more significant were 59.5% for the lyophilization, 6.2% with 6 cycles of freeze and thawing and around 100% for 2 and 4% (v/v) of H2SO4 at 121 °C for 30 min. Some of the methods that were described in this study are interesting to facilitate cost-efficient conversion of microalgal biomass into biofuels.info:eu-repo/semantics/publishedVersio

Drusas y la enfermedad retinal, degeneración macular relacionada con la edad

La Degeneración macular debida a la edad es la principal causa de ceguera irreversible en países industrializados. Se trata de una enfermadad debida a cambios fisiológicos y moleculares en nuestra retina, que acontecen a partir de los 55 años de edad, siendo el envejecimiento el factor clave de su desarrollo. Estos cambios se producen principalmente en el epitelio pigmentario de la retina (EPR), membrana de Bruch (MB) y coroides. En dichas estructuras se pueden observar cambios morfológicos, que pueden dar lugar a la pérdida de la función visual, tales como: drusas, alteraciones pigmentarias en el EPR y/o neovascularización. Gracias a diversas pruebas llevadas a cabo en la clínica diaria del óptico-optometrista, tales como: retinografía, OCT o autofluorescencia del fondo de ojo, se pueden detectar alguno de los cambios arriba indicados, pudiendo hacer un diagnóstico de la enfermedad y facilitar al oftalmólogo el seguimiento de esta. Así mismo, el óptico optometrista debe aconsejar a los pacientes, fundamentalmente a niños y jóvenes, sobre hábitos saludables, como la protección de la luz, en especial la luz azul, tabaquismo y consumo de una dieta completa. La revisión del tema presentado en este Trabajo Fin de Grado, puede facilitar al óptico-optometrista la interpretación de los resultados que se obtienen con las pruebas diagnósticas.Grado en Óptica y Optometrí

Importance of competitive ability in plant invasions: an experiment with two alien "Carpobrotus" species

Traballo fin de grao (UDC.CIE). Bioloxía. Curso 2016/2017[Resumen] Las especies invasoras son consideradas actualmente como la segunda causa de la pérdida biológica y funcional del sistema debido a la destrucción de los hábitats. Esto se debe a que presentan características que suponen una ventaja frente a las especies nativas, entre ellas destaca la elevada capacidad competitiva, que supone un beneficio en la lucha por los recursos, y además parece ser un factor importante que determina el potencial invasor. En este estudio utilizamos dos especies de Carpobrotus: Carpobrotus edulis y Carpobrotus acinaciformis, especies invasoras clonales en la Península Ibérica. Nuestro estudio muestra que no existen diferencias entre ambas especies. Sin embargo, resultados obtenidos podrían indicar que C. edulis presenta una mayor habilidad competitiva.[Resumo] As especies invasoras considéranse actualmente como a segunda causa da pérdida biolóxica e funcional do sistema debido á destrucción dos hábitats. Isto débese a que presentan características que supoñen unha ventaxa fronte ás especies nativas, entre ellas destaca a elevada capacidade competitiva, que supoñe un beneficio na loita polos recursos, e ademáis parece ser un factor importante que determina o potencial invasor. Neste estudio utilizamos dúas especies de Carpobrotus: Carpobrotus edulis e Carpobrotus acinaciformis, especies invasoras clonais na Península Ibérica. O noso estudio amosa que non existen diferenzas entre ambas especies. Sen embargo, resultados obtidos poderían indicar que C. edulis presenta una maior habilidade competitiva.[Abstract] Invasive species are currently considered the second cause of biological and functional loss of the system due to the destruction of habitats. This is due to the fact that they present characteristics that represent an advantage over the native species, among them the high competitive capacity, which is a benefit in the struggle for recources, and also seems to be an important factor that determines the invading potential. In this study we used two species of Carpobrotus: Carpobrotus edulis and Carpobrotus acinaciformis, clonal invasive species in the Iberian Peninsula. Our Study shows that there are no diferences between the two species. However, results obtained could indicate that C. edulis presents a greater competitive ability

The Subject, Feminist Theory and Latin American Texts

From a feminist perspective, this essay reviews and analyzes the interaction between metropolitan feminist theories and their interphase with the academic criticism of texts written by Latin American women. Discussion focuses on the question of the subject, which the author believes to be paramount in feminist theory, in as much as the construction of gender and the historical subordination of women devolve on the play of difference and identity. This paper examines how the problematic assumption by feminist theorists in the North American academy of Freudian and Lacanian theories of the subject pose unresolved problems and unanticipated complications to subsequent deployment of this subject theory as modes of interpretation of texts written by women in Latin America or even to the emancipatory goals on feminists in the academy. This is a case where traveling theory must be examined and evaluated very carefully. The second part of the paper concentrates on the feminist challenges that have been already made to both Freudian and Lacanian theories of the feminine. It highlights the work of Jane Flax, Nacy Chodorov, Gayatri Spivak and Judith Butler in suggesting a way out of theories that rely on the primacy of the male subject formation and therefore occlude and preclude the investigation of the modes of women\u27s agency

Exploring the relationship between toxin and spore production in the human enteric pathogen Clostridium difficile

RESUMO: Clostridium difficile é presentemente a principal causa de doença gastrointestinal associada à utilização de antibióticos em adultos. C. difficile é uma bactéria Gram-positiva, obrigatoriamente anaeróbica, capaz de formar endósporos. Tem-se verificado um aumento dos casos de doença associada a C. difficile com sintomas mais severos, elevadas taxas de morbilidade, mortalidade e recorrência, em parte, devido à emergência de estirpes mais virulentas, mas também devido à má gestão do uso de antibióticos. C. difficile produz duas toxinas, TcdA e TcdB, que são os principais fatores de virulência e responsáveis pelos sintomas da doença. Estas são codificadas a partir do Locus de Patogenicidade (PaLoc) que codifica ainda para um regulador positivo, TcdR, uma holina, TcdE, e um regulador negativo, TcdC. Os esporos resistentes ao oxigénio são essenciais para a transmissão do organismo e recorrência da doença. A expressão dos genes do PaLoc ocorre em células vegetativas, no final da fase de crescimento exponencial, e em células em esporulação. Neste trabalho construímos dois mutantes de eliminação em fase dos genes tcdR e tcdE. Mostrámos que a auto-regulação do gene tcdR não é significativa. No entanto, tcdR é sempre necessário para a expressão dos genes presentes no PaLoc. Trabalho anterior mostrou que, com a exceção de tcdC, os demais genes do PaLoc são expressos no pré-esporo. Mostrámos aqui que TcdA é detectada à superfície do esporo maduro e que a eliminação do tcdE não influencia a acumulação de TcdA no meio de cultura ou em associação às células ou ao esporo. Estas observações têm consequências para o nosso entendimento do processo infecioso: sugeremque o esporo possa ser também um veículo para a entrega da toxina nos estágios iniciais da infecção, que TcdA possa ser libertada durante a germinação do esporo, e que o esporo possa utilizar o mesmo receptor reconhecido por TcdA para a ligação à mucosa do cólon.---------------------------ABSTRACT: Clostridium difficile is currently the major cause of antibiotic-associated gastrointestinal diseases in adults. This is a Gram-positive bacterium, endospore-forming and an obligate anaerobe that colonizes the gastrointestinal tract. Recent years have seen a rise in C. difficile associated disease (CDAD) cases, associated with more severe disease symptoms, higher rates of morbidity, mortality and recurrence, which were mostly caused due to the emergence of “hypervirulent” strains but also due to changing patterns of antibiotics use. C. difficile produces two potent toxins, TcdA and TcdB, which are the main virulence factors and the responsible for the disease symptoms. These are codified from a Pathogenicity Locus (PaLoc), composed also by the positive regulator, TcdR, the holin-like protein, TcdE, and a negative regulator, TcdC. Besides the toxins, the oxygen-resistant spores are also essential for transmission of the organism through diarrhea; moreover, spores can accumulate in the environment or in the host, which will cause disease recurrence. The expression of the PaLoc genes occurs in vegetative cells, at the end of the exponential growth phase, and in sporulating cells. In this work, we constructed two in-frame deletion mutants of tcdR and tcdE. We showed that the positive auto regulation of tcdR is not significant. However, tcdR is always necessary for the expression of the PaLoc genes. A previous work showed that, except tcdC, all the PaLoc genes are expressed in the forespore. Here, we detected TcdA at the spore surface. Furthermore, we showed that the in-frame deletion of tcdE does not affect the accumulation of TcdA in the culture medium or in association with cells or spores. This data was important for us to conclude about the infeccious process: it suggests that the spore may be the vehicle for the delivery of TcdA in early stages of infection, that TcdA may be released during spores germination and that this spore may use the same receptor recognized by TcdA to bind to the colonic mucosa

Book review: Manufacturing celebrity: Latino paparazzi and women reporters in Hollywood by Vanessa Díaz

In Manufacturing Celebrity: Latino Paparazzi and Women Reporters in Hollywood, Vanessa Díaz demystifies the role of the Latino paparazzi and women reporters in celebrity media production. At a time of great upheaval in labour markets, Díaz’s interdisciplinary analyses at the intersection of work, race, gender and media are particularly insightful and relevant, writes Jonathan Pye and Sara Castro Cantú. Manufacturing Celebrity: Latino Paparazzi and Women Reporters in Hollywood. Vanessa Díaz. Duke University Press. 2020

Fernanda Seixas, el posicionamiento de una mujer sobre la arquitectura como intervención social

This paper sheds light upon architect Fernanda Seixas (1942-2017) as a trailblazing woman in her disciplinary field in Portugal. Her archives, a set of interviews, and bibliographical research allow us to pinpoint certain characteristics that make her stand out amongst her peers, and consider her as a woman succeeding in a ‘male profession’. Trained during an era of political dissent in which she actively participated against the dictatorship of Estado Novo in the 1960s, Seixas created her own practice right after the 1974 revolution and envisaged her work as a space of socio-political activism. In the 1980s her social consciousness broadened to include environmental concerns and she became a pioneering architect on the issues of energy efficiency and bioclimatic architecture. This technical approach combined with her social ethos stand out in her planning projects and built work.Este artículo arroja luz sobre la arquitecta Fernanda Seixas (1942-2017) como una mujer vanguardista en el contexto disciplinar de Portugal. Su archivo, una serie de entrevistas y la búsqueda bibliográfica nos permiten señalar ciertas características que la hacen destacar entre sus colegas y considerarla una mujer triunfadora en una ‘profesión masculina’. Formada durante una época de disidencia política en la que participó activamente contra la dictadura del Estado Novo en la década de 1960, Seixas creó su propia práctica justo después de la revolución de 1974 y concibió su trabajo como un espacio de activismo sociopolítico. En la década de 1980, su conciencia social se amplió para incluir preocupaciones medioambientales y se convirtió en una arquitecta pionera en el tema de la eficiencia energética y la arquitectura bioclimática. Este enfoque técnico combinado con su énfasis en la conciencia social se destaca en sus proyectos de planificación y obra construida

Book review: Manufacturing celebrity: Latino paparazzi and women reporters in Hollywood by Vanessa Díaz

In Manufacturing Celebrity: Latino Paparazzi and Women Reporters in Hollywood, Vanessa Díaz demystifies the role of the Latino paparazzi and women reporters in celebrity media production. At a time of great upheaval in labour markets, Díaz’s interdisciplinary analyses at the intersection of work, race, gender and media are particularly insightful and relevant, writes Jonathan Pye and Sara Castro Cantú. Manufacturing Celebrity: Latino Paparazzi and Women Reporters in Hollywood. Vanessa Díaz. Duke University Press. 2020

The unequal opportunity for skills acquisition during the Great Recession in Europe

This paper is the first to investigate the extent to which the high levels of Joblessness resulting from the Great Recession across Europe have translated into higher school attendance among youth. Using cross-sectional and longitudinal data from the EU-S ILC for 28 countries, we establish a robust counter-cyclical relationship between rising unemployment rates and school enrolment. The same is true of transitions back to education. Our analysis by subgroups reveals a worrying trend, with youths who have the most disadvantaged backgrounds (measured by low household income) less likely to enrol in tertiary studies when unemployment rises. Keywords: Unemployment, school enrolment, transitions back to education, youth, Great Recession, EU-SIL

Spiraling effects of poverty on child development. A neuroethical study

info:eu-repo/semantics/publishedVersio