960 resultados para Buildings -- Repair and reconstruction


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DNA repair mechanisms constitute an essential cellular response to DNA damage arising either from metabolic processes or from environmental sources such as ultraviolet radiation. Repair of these lesions may be via direct reversal, or by processes such as nucleotide excision repair (NER), a coordinated pathway in which lesions and the surrounding nucleotides are excised and replaced via DNA resynthesis. The importance of repair is illustrated by human disease states such as xeroderma pigmentosum and Cockayne's syndrome which result from defects in the NER system arising from mutations in XP- genes or XP- and CS- genes respectively Little detail is known of DNA damage repair processes in plants, despite the economic and ecological importance of these organisms. This study aimed to expand our knowledge of the process of NER in plants, largely via a polymerase chain reaction (PCR)-based approach involving amplification, cloning and characterisation of plant genomic DNA and cDNA. Homologues of the NER components XPF/RAD1 and XPD/RAD3 were isolated as both genomic and complete cDNA sequences from the model dicotyledonous plant Arabidopsis thaliana. The sequence of the 3'-untranslated region of atXPD was also determined. Comparison of genomic and cDNA sequences allowed a detailed analysis of gene structures, including details of intron/exon processing. Variable transcript processing to produce three distinct transcripts was found in the case of atXPF. In an attempt to validate the proposed homologous function of these cDNAs, assays to test complementation of resistance to ultraviolet radiation in the relevant yeast mutants were performed. Despite extensive amino acid sequence conservation, neither plant cDNA was able to restore UV-resistance. As the yeast RAD3 gene product is also involved in vivo in transcription, and so is required for viability, the atXPD cDNA was tested in a complementation assay for this function in an appropriate yeast mutant. The plant cDNA was found to substantially increase the viability of the yeast mutant. The structural and functional significance of these results is discussed comparatively with reference to yeast, human and other known homologues. Other putative NER homologues were identified in A. thaliana database sequences, including those of ERCC1/RAD10 and XPG/ERCC5/RAD2, and are now the subjects of ongoing investigations. This study also describes preliminary investigations of putative REVS and RAD30 translesion synthesis genes from A. thaliana.

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A series of shapes of silver nanoplates were achieved by adjusting the concentration of citrate in the colloid in the photoinduced process. The local surface plasmon resonance (LSPR) of the silver nanoplates could be tuned gradually in a range from 740 to 440 nm. In contrast, the LSPR band can be photomediated again to the long wavelength region within 620-690 nm only by adding more citrate to the colloidal system. The initial silver nanoprisms converted to the discal shape under the light effect. In this conversion, the coupling effect of the plasmon resonance and the light source speeds up the photothermal reaction. Subsequently, the reconstruction of silver nanoprisms from the nanodisks took place in the presence of more citrate through the photoconversion.

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Research which explores the experiences of women, who have experienced childhood sexual abuse is, in the main, focused on young and middle aged women. The perspectives of older women is often absent or hidden in the literature. This study explores the experiences of 16 Australian women aged 57 years and older who have experienced childhood sexual abuse. It aims to privilege their views and highlight their particular contexts in order to redress professional assumptions regarding the notions of recovery. Additionally, in discussing their experiences, the women contribute to insights regarding the patterns of inequality which are produced as a result of dominant discourses that promote ageist and sexist prescriptions in the construction of the self. These insights demonstrate how the women have resisted a range of oppressive patterns in their everyday lives. The study follows a feminist research framework and aims to contribute to the fields of social work practice and critical feminist gerontology.

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The aim of this book is to examine new forms of resistance to social injustices in contemporary Western societies. Resistance requires agency, and agency is grounded in notions of the subject and subjectivity. It is a premise of this book that new and/or reconstructed forms of subjectivity are required to challenge social relations of subordination and domination.
Subjectivity is primarily based on lived experience. While subjectivity is sometimes used to explore individualistic strategies for personal meaning, we argue that subjectivity is central to political struggles against regimes of power. Thus, understanding how subjects are constituted is important in fostering the capacity of critical reflection and social transformation.
Our aim  is to understand the relationship between subjectivity and the wider social order. The relationship between the psyche and society is one of the most challenging issues facing social theory. While there is a variety of theoretical approaches to subjectivity, those that explore the links between the subject and society are the most promising in developing strategies for resistance. In this introductory chapter, we review and interrogate what we believe are the most important theoretical approaches to subjectivity, drawing upon Marxism, critical theory, feminism, postcolonialism and post-structuralism. Our aim in this book is not to develop a new theory of subjectivities. Rather, we are more concerned with investigating how diverse subjectivities are constructed and reconstructed.

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 This research explores personal stories of 16 Australian women aged 57 years and older who have experienced childhood sexual abuse. It privileges their views and examines how they managed the impact during their lives. The project contributes to professional knowledge by developing anti-ageist practices for social work and human services.

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Periapical repair and apical bridging were studied in dog's teeth with incomplete root formation and induced chronic periapical lesions treated with different dressings. A total of 75 root canals from the upper and lower premolars of 4 dogs approximately 6 months of age were chemo-mechanically prepared and filled with the following dressings: antibacterial dressing consisting of a calcium hydroxide+camphorated p-monochlorophenol paste applied for 7 days and followed by monthly renewed calcium hydroxide paste as temporary dressing at 30, 60 and 90 days (Group A); antibacterial dressing consisting of camphorated p-monochlorophenol alone for 7 days, followed by temporary dressing with calcium hydroxide paste renewed at 30, 60 and 90 days (Group B). A control group (Group C) received no dressings. Ninety days after the last calcium hydroxide paste (Groups A, B) and after the last irrigation/aspiration (Group C), the animals were killed, the maxillae and mandibles were removed, and the material submitted to routine histological processing and examination. Both root canal dressings, were of fundamental importance for apical repair and bridging. The apical bridging was predominantly complete in Group A, incomplete in Group B, and absent in Group C. The calcium hydroxide+camphorated p-monochlorophenol combination gave better results than camphorated p-monochlorophenol alone.