956 resultados para Sewerage -- Maintenance and repair


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The major barrier to practical optimization of pavement preservation programming has always been that for formulations where the identity of individual projects is preserved, the solution space grows exponentially with the problem size to an extent where it can become unmanageable by the traditional analytical optimization techniques within reasonable limit. This has been attributed to the problem of combinatorial explosion that is, exponential growth of the number of combinations. The relatively large number of constraints often presents in a real-life pavement preservation programming problems and the trade-off considerations required between preventive maintenance, rehabilitation and reconstruction, present yet another factor that contributes to the solution complexity. In this research study, a new integrated multi-year optimization procedure was developed to solve network level pavement preservation programming problems, through cost-effectiveness based evolutionary programming analysis, using the Shuffled Complex Evolution (SCE) algorithm.^ A case study problem was analyzed to illustrate the robustness and consistency of the SCE technique in solving network level pavement preservation problems. The output from this program is a list of maintenance and rehabilitation treatment (M&R) strategies for each identified segment of the network in each programming year, and the impact on the overall performance of the network, in terms of the performance levels of the recommended optimal M&R strategy. ^ The results show that the SCE is very efficient and consistent in the simultaneous consideration of the trade-off between various pavement preservation strategies, while preserving the identity of the individual network segments. The flexibility of the technique is also demonstrated, in the sense that, by suitably coding the problem parameters, it can be used to solve several forms of pavement management programming problems. It is recommended that for large networks, some sort of decomposition technique should be applied to aggregate sections, which exhibit similar performance characteristics into links, such that whatever M&R alternative is recommended for a link can be applied to all the sections connected to it. In this way the problem size, and hence the solution time, can be greatly reduced to a more manageable solution space. ^ The study concludes that the robust search characteristics of SCE are well suited for solving the combinatorial problems in long-term network level pavement M&R programming and provides a rich area for future research. ^

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This study examined the long-term effects of bilingual education/ESOL instruction on Hispanic university students' subsequent Spanish language maintenance using sociolinguistic methodology as its framework. The study investigated whether or not Hispanic university students who had participated in bilingual or ESOL classes in their elementary schooling maintained Spanish as young adults. Maintenance included using Spanish in their personal and professional lives and demonstrating written competence in Spanish, as well as whether subjects considered themselves to be bilingual, how they rated their ability in different skill areas for the two languages, and if they exhibited positive attitudes toward language and education as compared to Hispanic students who had experienced an all English classroom situation. A Language and Education Survey was developed to collect data pertaining to these areas. ^ A convenience sample of 202 Hispanic undergraduate university students enrolled in education classes at Florida International University during the 2000–2001 academic year participated in the study. Subjects were grouped according to the type of program they had experienced at the elementary school level, Bilingual/ESOL and All English. ^ Statistically significant differences were found between the groups in subjects' self-ratings of their abilities in speaking, reading, writing, and comprehension. No statistically significant differences were found with respect to the continuation of Spanish language study at the secondary school or college levels although there was a significant difference in number of semesters for those who planned to do so. ^ In language use, there were statistically significant differences overall as there were in the personal domain, but none were found in the professional domain; nor were there any statistically significant differences between the groups with respect to attitudes regarding education and language. There were statistically significant differences between the two groups for communicative competence in written Spanish. These statistically significant findings in language ability, language use and written communicative competence indicated that Hispanic university students who were enrolled in bilingual programs/ESOL in their earlier schooling did maintain Spanish as their native language as compared to Hispanic students who did not participate in such programs. ^

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The adaptive significance of herbivory in nature is not well understood. In order to document the conditions that select for an herbivorous feeding habit, we must first understand how such a diet is maintained, and the consequences of doing so. A few studies have begun to reveal mechanisms of maintaining herbivory (i.e. selective feeding, diet mixing, etc.) and the associated life history responses (i.e. growth, reproduction, etc.) in terrestrial and marine systems; however, studies of this kind are underrepresented in the freshwater literature. In this study, I use the sailfin molly (Poecilia latipinna) as a model organism to examine diet selectivity and the effects of an herbivorous diet on growth. To study food selectivity, sailfin mollies were fed either disturbed or intact periphyton mats from one of three localities within the Everglades (Water Conservation Area 3B, the Gap, or Chekika). Mats are structured with palatable algal species (i.e. greens and diatoms) comprising the inner components of the mat, and unpalatable species (i.e. cyanobacteria) comprising the outer edges. Fish gut contents were analyzed for each treatment and periphyton locality. Results suggest that when provided access to the inner components of the mats, fish preferentially eat more palatable algae. In a second experiment, effects of an herbivorous diet were examined using neonate sailfin mollies. Fish were fed either commercial food flakes, commercial algae flakes, or ground periphyton, and growth rate was measured weekly, from birth to 21 days. Fish fed the commercial diets grew at a faster rate and reached a larger final size than those fed periphyton. These results suggest that a periphyton diet is limited in nutritional elements compared to a pure algae diet and herbivorous organisms feeding upon it may experience negative effects on growth. By studying the costs and benefits of herbivory in a freshwater system, this paper contributes to a larger study of the question of why herbivory would evolve as an adaptation when seemingly inefficient compared to carnivorous and omnivorous diets.

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Centromeres are essential chromosomal loci at which kinetochore formation occurs for spindle fiber attachment during mitosis and meiosis, guiding proper segregation of chromosomes. In humans, centromeres are located at large arrays of alpha satellite DNA, contributing to but not defining centromere function. The histone variant CENP-A assembles at alpha satellite DNA, epigenetically defining the centromere. CENP-A containing chromatin exists as an essential domain composed of blocks of CENP-A nucleosomes interspersed with blocks of H3 nucleosomes, and is surrounded by pericentromeric heterochromatin. In order to maintain genomic stability, the CENP-A domain is propagated epigenetically over each cell division; disruption of propagation is associated with chromosome instabilities such as aneuploidy, found in birth defects and in cancer.

The CENP-A chromatin domain occupies 30-45% of the alpha satellite array, varying in genomic distance according to the underlying array size. However, the molecular mechanisms that control assembly and organization of CENP-A chromatin within its genomic context remain unclear. The domain may shift, expand, or contract, as CENP-A is loaded and dispersed each cell cycle. We hypothesized that in order to maintain genome stability, the centromere is inherited as static chromatin domains, maintaining size and position within the pericentric heterochromatin. Utilizing stretched chromatin fibers, I found that CENP-A chromatin is limited to a sub-region of the alpha satellite array that is fixed in size and location through the cell cycle and across populations.

The average amount of CENP-A at human centromeres is largely consistent, implying that the variation in size of CENP-A domains reflects variations in the number of CENP-A subdomains and/or the density of CENP-A nucleosomes. Multi-color nascent protein labeling experiments were utilized to examine the distribution and incorporation of distinct pools of CENP-A over several cell cycles. I found that in each cell cycle there is independent CENP-A distribution, occurring equally between sister centromeres across all chromosomes, in similar quantities. Furthermore, centromere inheritance is achieved through specific placement of CENP-A, following an oscillating pattern that fixes the location and size of the CENP-A domain. These results suggest that spatial and temporal dynamics of CENP-A are important for maintaining centromere and genome stability.

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This article presents the methodology and main results obtained in Spain within the FORMAR project, a European-funded project under the Leonardo Da Vinci scheme (Lifelong Learning Programme), whose main goal is to jointly develop training resources and modules to improve the skills on sustainability issues of buildings maintenance and refurbishment workers, in three different European countries: Spain, Portugal (Project Coordinator) and France. The Units of Short-term Training (UST) developed within this project are focused on the VET of carpenters, painters, bricklayers, building technicians and installers of solar panels, and a transversal unit containing basic concepts on sustainable construction and nearly Zero Energy Buildings (n-ZEB) is also developed. In parallel, clients’ guides for the aforementioned professionals are also implemented to improve the information provided to clients and owners in order to support the procurement decisions regarding building products and materials. Therefore, the project provides an opportunity to exchange experiences between organizations of these three European countries, as the UST will be developed simultaneously in each of them, exploring opportunities for training, guidance and exchange of experience. Even though the UST will have a common structure and contents, they will be slightly different in each country to adapt them to the different specific training needs and regulations of Spain, Portugal and France. This paper details, as a case study, the development process of the UST for carpenters and building technicians in Spain, including the analysis of needs and existing training materials, the main contents developed and the evaluation and testing process of the UST, which involves the active participation of several stakeholders of this sector as well as a classroom testing to obtain the students’ feedback.

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This study reports on research that examines the family language policy (FLP) and biliteracy practices of middle-class Chinese immigrant families in a metropolitan area in the southwest of the U.S. by exploring language practices pattern among family members, language and literacy environment at home, parents’ language management, parents’ language attitudes and ideologies, and biliteracy practices. In this study, I employed mixed methods, including survey and interviews, to investigate Chinese immigrant parents’ FLP, biliteracy practices, their life stories, and their experience of raising and nurturing children in an English-dominant society. Survey questionnaires were distributed to 55 Chinese immigrant parents and interviews were conducted with five families, including mothers and children. One finding from this study is that the language practices pattern at home shows the trend of language shift among the Chinese immigrants’ children. Children prefer speaking English with parents, siblings, and peers, and home literacy environment for children manifests an English-dominant trend. Chinese immigrant parents’ language attitudes and ideologies are largely influenced by English-only ideology. The priority for learning English surpasses the importance of Chinese learning, which is demonstrated by the English-dominant home literacy practices and an English-dominant language policy. Parents invest more in English literacy activities and materials for children, and very few parents implement Chinese-only policy for their children. A second finding from this study is that a multitude of factors from different sources shape and influence Chinese immigrants’ FLP and biliteracy practices. The factors consist of family-related factors, social factors, linguistic factors, and individual factors. A third finding from this study is that a wide variety of strategies are adopted by Chinese immigrant families, which have raised quite balanced bilingual children, to help children maintain Chinese heritage language (HL) and develop both English and Chinese literacy. The close examination and comparison of different families with English monolingual children, with children who have limited knowledge of HL, and with quite balanced bilingual children, this study discovers that immigrant parents, especially mothers, play a fundamental and irreplaceable role in their children’s HL maintenance and biliteracy development and it recommends to immigrant parents in how to implement the findings of this study to nurture their children to become bilingual and biliterate. Due to the limited number and restricted area and group of participant sampling, the results of this study may not be generalized to other groups in different contexts.

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The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8-oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty-two healthy Caucasian men (40-74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild-type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG-sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG-sensitive sites) and repair activity (OGG1) between genotype groups (in the pre-training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG-sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism.

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The information enclosed in this booklet consists of memos, policy statements and other pertinent information to guide you in the establishment of a backflow prevention program.

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The emergency repair activity under the South Carolina Housing Trust Fund program is designed to assist very low‐income homeowners in making needed and necessary repairs to their owner‐occupied homes to eliminate life, health and safety issues to the occupant. This document explains emergency repair activity guidelines, eligibility requirements for properties, rehabilitation construction guidelines and payments.

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Historically SCDOT ranks in the top 10 each year for highway conditions and cost-effectiveness as rated by the Reason Foundation. With billions of dollars invested and billions to be invested it makes sense to invest the public's tax dollars as wisely as possible. Therefore, assessing what we have or better yet what condition what we have is in can be vital to public safety and setting priorities. The focus of this project is on the maintenance responsibility of Roadway Inspection as outlined in SCDOT Engineering Directive Memorandum #8. This memorandum is a portion of the way SCDOT provides for the safety of the traveling public and keeps South Carolina's most expensive asset in working order.

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In chronic pain, opioids represent the gold standard analgesics, but their use is hampered by the development of several side effects, as development of analgesic tolerance and opioid-induced hyperalgesia. Evidence showed that many molecular mechanisms (changes in opioid receptors, neurotransmitter release, and glia/microglia activation) are involved in their appearance, as well as in chronic pain. Recently, a crucial role has been proposed for oxidative stress and proteasome in chronic pain and in treatment-related side effects. To better elucidate these aspects, the aim of this PhD thesis was to investigate the effects of opioids on cell oxidative stress, antioxidant enzymatic machinery and proteasome expression and activity in vitro. Also, the involvement of proteasome in the development of chronic pain conditions was investigated utilizing an experimental model of oxaliplatin-induced neuropathy (OXAIN), in vivo. Data showed that morphine, fentanyl, buprenorphine and tapentadol alter differently ROS production. The ROS increasing effect of morphine is not shared by the other opioids, suggesting that the different pharmacological profile could influence this parameter. Moreover, these drugs produced different alterations of β2trypsin-like and β5chymotrypsin-like activities. In fact, while morphine and fentanyl increased the proteolytic activity after prolonged exposure, a different picture was observed for buprenorphine and tapentadol, suggesting that the level of MOR agonism could be strongly related with proteasome activation. In vivo studies revealed that rats treated with oxaliplatin showed a significant increase in β5, in the thalamus (TH) and somatosensory cortex (SSCx). Moreover, a selective up-regulation of β5 and LMP7 subunit gene expression was assessed in the SSCx. Furthermore, our study revealed that oprozomib, a selective β5 inhibitor normalized the spinal prodynorphin gene expression upregulation induced by oxaliplatin, and reverted mechanical/thermal allodynia and mechanical hyperalgesia in oxaliplatin-treated rats. These results underline the role of proteasome in the OXAIN and suggest new pharmacological targets to counteract it.

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Dissertação para obtenção de grau de Mestre em Engenharia Civil na Área de Especialização de Edificações

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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Edificações

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RÉSUMÉ DE THÈSE Au cours de ma thèse, je me suis intéressée aux causes physiologiques du vieillissement en utilisant les fourmis comme modèle. Les trois castes de fourmis - les mâles, les ouvrières et les reines - présentent des longévités très différentes, tout en étant génétiquement identiques. Ceci implique que les différences de longévité sont dues à des variations entre castes dans le pattern d'expression de gènes. Mon travail chez la fourmi a consisté d'une part à mettre en place les outils pour identifier de tels gènes à grande échelle, de l'autre à étudier le rôle de gènes et de mécanismes qui affectent la longévité chez d'autres espèces. Pour identifier de nouveaux gènes potentiellement impliqués dans le vieillissement, nous avons développé des puces à ADN. Cette technique permet la comparaison du niveau d'expression de milliers de gènes entre deux échantillons. L'application de cette méthode aux reines et ouvrières adultes nous a jusqu'à présent permis d'identifier neuf gènes surexprimés chez les reines. Trois d'entre eux sont potentiellement impliqués dans le maintien et la réparation du soma, deux processus qui sont supposés avoir un impact crucial sur la longévité. Parmi les mécanismes impliqués dans le vieillissement chez d'autres espèces, nous nous sommes principalement intéressés aux télomères, qui sont les extrémités des chromosomes. Chez les vertébrés, les télomères se raccourcissent à chaque division cellulaire, entre autres parce que l'ADN polymérase ne peut répliquer cette partie des chromosomes en entier. Or des télomères courts entravent la prolifération des cellules et peuvent même induire l'apoptose, ce qui pourrait se répercuter sur la capacité des organismes à régénérer des tissus. J'ai pu montrer que chez les fourmis mâles (la caste qui vit le moins longtemps) les télomères se raccourcissent beaucoup plus vite que chez les reines et les ouvrières. L'explication la plus plausible pour cette différence est que les mâles, étant adapté à une vie très éphémère, n'investissent qu'un minimum d'énergie dans la machinerie de maintenance qui assure le bon fonctionnement des cellules. Ces résultats sont intéressants car ils permettent pour la première fois de faire le lien entre les théories évolutives du vieillissement et la biologie des télomères. THESIS ABSTRACT During my thesis I used ants as a model to study the proximate (i.e., molecular) causes of ageing and lifespan determination. Ant queens, workers and males differ tremendously in lifespan, although all three castes are genetically identical. Importantly, this implies that genes and molecular pathways responsible for modulating lifespan are regulated in a caste-specific manner. To find new genes potentially involved in ageing, we first constructed 371-gene-cDNA microarrays for the ant L. niger. This molecular tool can be used to survey the relative gene expression levels of two samples for thousands of genes simultaneously. By applying this method to adult queens and workers we identified nine genes that are overexpressed in queens. Three of them are putatively involved in somatic maintenance and repair, two processes that have been previously suggested as important for ageing and lifespan determination. We expect to identify many more candidate genes in the near future by using the 9000-gene fire ant microarrays we have recently developed. We also investigated whether factors linked to ageing in other organisms could affect lifespan determination in ants. One project was on telomeres, the ends of linear chromosomes. For various reasons telomeres shorten with every cell division. Since short telomeres can lead to cellular defects such as impaired cell division, telomeres have been hypothesized as playing a role in ageing. We tested whether telomere length in ant somatic tissues correlates with caste-specific lifespan in young adults. The short-lived L. niger mates did indeed have significantly shorter telomeres than the longer-lived queens and workers, probably because telomere attrition is faster in males than in queens and workers. Queens did not, however, have longer telomeres than the shorter-lived workers. These findings are consistent with the idea that telomere length may play a role in ageing under some circumstances, but they also clearly demonstrate that other factors must be involved. We argue that sex-specific telomere length patterns in ants ultimately reflect adaptive differences in the level of somatic maintenance between males and females, and thus create a link between telomere biology and the evolutionary theory of ageing.