• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 20
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 46
  • 10
  • 10
  • 9
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliação da presença de metilparabeno e propilparabeno no ambiente aquático e seus potenciais estrogênicos e a toxicidade aguda. / Evaluation of the presence of methylparaben and propylparaben in the aquatic environment and their potential estrogenic and acute toxicity.

Carolina Gomes Moreira 14 April 2014 (has links)
Atualmente no cenário mundial a qualidade da água tem gerado muitas preocupações, pois milhares de produtos sintéticos são produzidos para facilitar muitas práticas industriais, domésticas e pessoais e com isso diversas substâncias químicas utilizadas para esses fins são introduzidas no meio ambiente. Os parabenos são substâncias químicas utilizadas pelas indústrias farmacêuticas, de alimentos e cosméticos e que cuja função é a conservação, sendo que há muitos questionamentos em relação a sua segurança, pois alguns relatórios têm mostrado que a exposição a esses parabenos pode modular ou perturbar o sistema endócrino e com isso gerar consequências prejudiciais à saúde humana e aos ambientes aquáticos. Esse estudo teve como objetivo avaliar a presença dos Parabenos Metilparabeno e Propilparabeno no ambiente aquático e os seus potenciais estrogênicos e a toxicidade aguda. A metodologia se desenvolveu a partir do ensaio in vitro YES para a determinação da atividade estrogênica, ensaios de toxicidade aguda em Daphnia similis e em Aliivibrio fischeri e a quantificação dos parabenos na água do Rio Maracanã-RJ através da cromatografia líquida acoplada ao espectrômetro de massa. Os resultados obtidos para a CE50 dos MP e PP, a partir do ensaio in vitro YES, foi de 18,91 mgL-1 e 7 mgL-1 e a magnitude da resposta foi de 10-5 e 10-4 menos potente que 17ß-estradiol para o MP e o PP, respectivamente. A partir do ensaio de toxicidade aguda, os valores de CE50 obtidos em Daphnia similis, foi de 29,42 mgL-1 e 9,94 mgL-1e em Aliivibrio fischeri foi de 3,047 mgL-1 e 1,946 mgL-1, respectivamente, com isso observou-se que o PP é mais tóxicos em todos os organismos testados, sendo mais tóxicos para um e menos para outros. A água do Rio Maracanã não foi tóxica para a Daphnia similis em nenhum dos dois pontos, já para o Aliivibrio fischeri foi tóxica em apenas um ponto. As concentrações encontradas de MP e PP foram maiores no ponto onde, de acordo com os parâmetros físico-químicos, a qualidade da água não está dentro dos padrões exigidos pela legislação, sendo quantificados na ordem de ngL-1, contudo é válido ressaltar que os DEs não são encontrados no meio ambiente separados, eles interagem entre si e provocam efeitos aditivos ou sinérgicos, sendo muito difícil de prever qual o efeito, por isso é importante o conhecimento do potencial estrogênico das substâncias simples, pois em um estudo com uma matriz ambiental, pode-se observar se houve algum efeito aditivo ou sinérgico de outras substâncias. / Currently on the world stage water quality has generated many concerns, because thousands of synthetic products are produced to facilitate many industrial, domestic and personal practices and thereby various chemicals used for these purposes are introduced into the environment. Parabens are chemicals used by the pharmaceutical, food and cosmetic and whose function is to conserve, and there are many questions regarding its safety , as some reports have shown that exposure to these parabens can modulate or disrupt endocrine system and thereby generate harmful consequences for human health and aquatic environments . The aim of this study was to evaluate the presence of Methylparaben and Propylparaben in the aquatic environment and their potential estrogenic and acute toxicity. The methodology developed from the in vitro YES assay for the determination of estrogenic activity, acute toxicity tests with Daphnia similis and Aliivibrio fischeri and quantification of parabens in water of Maracanã River RJ by liquid chromatography coupled with mass spectrometry. The EC50 results for the PP and MP, from the in vitro YES, was 18,91 mgL -1 and 7 mgL-1 and the magnitude of response was less potent 10-5 and 10-4 that 17ß - estradiol for MP and PP , respectively. From the acute toxicity test, the EC50 values obtained in Daphnia similis was 29,42 mgL-1 and 9,94 mgL-1, and Aliivibrio fischeri was 3,047 mgL-1 and 1,946 mgL-1, respectively, with it was observed that PP is more toxic in all organisms tested, and more toxic to one and less to others . The water of the Maracanã River was not toxic to Daphnia similis in either points, since for Aliivibrio fischeri was toxic at only one point. Found concentrations of MP and PP were higher at the point where, according to the physico-chemical parameters, water quality is not within the standards required by legislation and quantified in order ngL-1, however its worth to note that the DEs are not found in the middle separate environment, they interact with each other and cause additive or synergistic effects , its very difficult to predict what effect , so its important to know the estrogenic potential of simple substances , since in a study with an environmental matrix, one can observe if there were any additive or synergistic effect of other substances .
12

Avaliação da presença de metilparabeno e propilparabeno no ambiente aquático e seus potenciais estrogênicos e a toxicidade aguda. / Evaluation of the presence of methylparaben and propylparaben in the aquatic environment and their potential estrogenic and acute toxicity.

Carolina Gomes Moreira 14 April 2014 (has links)
Atualmente no cenário mundial a qualidade da água tem gerado muitas preocupações, pois milhares de produtos sintéticos são produzidos para facilitar muitas práticas industriais, domésticas e pessoais e com isso diversas substâncias químicas utilizadas para esses fins são introduzidas no meio ambiente. Os parabenos são substâncias químicas utilizadas pelas indústrias farmacêuticas, de alimentos e cosméticos e que cuja função é a conservação, sendo que há muitos questionamentos em relação a sua segurança, pois alguns relatórios têm mostrado que a exposição a esses parabenos pode modular ou perturbar o sistema endócrino e com isso gerar consequências prejudiciais à saúde humana e aos ambientes aquáticos. Esse estudo teve como objetivo avaliar a presença dos Parabenos Metilparabeno e Propilparabeno no ambiente aquático e os seus potenciais estrogênicos e a toxicidade aguda. A metodologia se desenvolveu a partir do ensaio in vitro YES para a determinação da atividade estrogênica, ensaios de toxicidade aguda em Daphnia similis e em Aliivibrio fischeri e a quantificação dos parabenos na água do Rio Maracanã-RJ através da cromatografia líquida acoplada ao espectrômetro de massa. Os resultados obtidos para a CE50 dos MP e PP, a partir do ensaio in vitro YES, foi de 18,91 mgL-1 e 7 mgL-1 e a magnitude da resposta foi de 10-5 e 10-4 menos potente que 17ß-estradiol para o MP e o PP, respectivamente. A partir do ensaio de toxicidade aguda, os valores de CE50 obtidos em Daphnia similis, foi de 29,42 mgL-1 e 9,94 mgL-1e em Aliivibrio fischeri foi de 3,047 mgL-1 e 1,946 mgL-1, respectivamente, com isso observou-se que o PP é mais tóxicos em todos os organismos testados, sendo mais tóxicos para um e menos para outros. A água do Rio Maracanã não foi tóxica para a Daphnia similis em nenhum dos dois pontos, já para o Aliivibrio fischeri foi tóxica em apenas um ponto. As concentrações encontradas de MP e PP foram maiores no ponto onde, de acordo com os parâmetros físico-químicos, a qualidade da água não está dentro dos padrões exigidos pela legislação, sendo quantificados na ordem de ngL-1, contudo é válido ressaltar que os DEs não são encontrados no meio ambiente separados, eles interagem entre si e provocam efeitos aditivos ou sinérgicos, sendo muito difícil de prever qual o efeito, por isso é importante o conhecimento do potencial estrogênico das substâncias simples, pois em um estudo com uma matriz ambiental, pode-se observar se houve algum efeito aditivo ou sinérgico de outras substâncias. / Currently on the world stage water quality has generated many concerns, because thousands of synthetic products are produced to facilitate many industrial, domestic and personal practices and thereby various chemicals used for these purposes are introduced into the environment. Parabens are chemicals used by the pharmaceutical, food and cosmetic and whose function is to conserve, and there are many questions regarding its safety , as some reports have shown that exposure to these parabens can modulate or disrupt endocrine system and thereby generate harmful consequences for human health and aquatic environments . The aim of this study was to evaluate the presence of Methylparaben and Propylparaben in the aquatic environment and their potential estrogenic and acute toxicity. The methodology developed from the in vitro YES assay for the determination of estrogenic activity, acute toxicity tests with Daphnia similis and Aliivibrio fischeri and quantification of parabens in water of Maracanã River RJ by liquid chromatography coupled with mass spectrometry. The EC50 results for the PP and MP, from the in vitro YES, was 18,91 mgL -1 and 7 mgL-1 and the magnitude of response was less potent 10-5 and 10-4 that 17ß - estradiol for MP and PP , respectively. From the acute toxicity test, the EC50 values obtained in Daphnia similis was 29,42 mgL-1 and 9,94 mgL-1, and Aliivibrio fischeri was 3,047 mgL-1 and 1,946 mgL-1, respectively, with it was observed that PP is more toxic in all organisms tested, and more toxic to one and less to others . The water of the Maracanã River was not toxic to Daphnia similis in either points, since for Aliivibrio fischeri was toxic at only one point. Found concentrations of MP and PP were higher at the point where, according to the physico-chemical parameters, water quality is not within the standards required by legislation and quantified in order ngL-1, however its worth to note that the DEs are not found in the middle separate environment, they interact with each other and cause additive or synergistic effects , its very difficult to predict what effect , so its important to know the estrogenic potential of simple substances , since in a study with an environmental matrix, one can observe if there were any additive or synergistic effect of other substances .
13

Impact of After-School Programs on Rural Youth: A Case Study of Fusion Youth Centre

Khan, Bushra 19 December 2012 (has links)
This thesis investigates the impact of after-school programs on youth in rural communities. A case study of the Fusion Youth Activity and Technology Centre in Ingersoll, Ontario was conducted to explore the relationship between program participation and the development experiences of youth participants ages 12 to 18 years. The Youth Experience Survey created by Hansen and Larson (2002) was selected for this study to assess the positive and negative youth development experiences of Fusion youth participants, measuring experiences within conceptual domains of Identity Work, Initiative, Basic Skills, Positive Relationships, Team Work and Social Skills, Adult Networks and Social Capital, and Negative Experiences. The study found that all domains measuring positive youth development experiences were positively correlated, with the strongest experiences associated with the domains of Identity Work, Basic Skills, Positive Relationships, and Team Work and Social Skills. In addition, the study concluded that participants’ youth development significantly increased with duration of membership and intensity of participation at Fusion.
14

Patterns of stance taking:negative yes/no interrogatives and tag questions in American English conversation

Keisanen, T. (Tiina) 25 April 2006 (has links)
Abstract This thesis reports on an empirical study of the forms and functions of two interrelated syntactic constructions, tag questions and negative yes/no interrogatives, in naturally occurring American English conversations. More specifically, the thesis focuses on examining the ways in which these interrogative constructions are involved in the intersubjective and interactional construction of stance. This involves describing the linguistic and interactional practices through which speakers index and negotiate their evaluative, affective or epistemic position or point of view towards some matter in the local context. The data used in the study comprise naturally occurring face-to-face and telephone interactions the majority of which take place between family and friends. The data are drawn from the first three published parts of the Santa Barbara Corpus of Spoken American English.The study is based on the methodological and theoretical principles of interactional linguistics and conversation analysis. The first part of the study provides an examination of the linguistic and grammatical patterning of the chosen constructions in a database of naturally occurring interactions in English. This serves first of all as a study of the general linguistic patterning of utterances with negation or reversed word order in interaction. At the same time, however, the grammatical and semantic categories of person, verb type and tense are employed for establishing the high frequency of linguistic and semantic material that index the current speaker's affective, evaluative and/or epistemic position towards the issue at hand. The second part of the study expands the focus from individual utterances to the surrounding interactional context in which the interrogative constructions are located, and makes use of the conversation analytic methodology. I examine how discourse participants use negative yes/no interrogatives and tag questions as a resource for carrying out different actions such as requesting for confirmation, challenging, disagreeing and assessing, and the ways in which interrogative speakers convey their epistemic, affective or evaluative stances in so doing. In this section of the study the research proceeds through detailed analyses of interaction, and an examination of those sequential environments in which the interrogative constructions are found.
15

Endothelial Heat Shock Protein A12B and Yes-associated Protein Cooperatively Promote Angiogenesis Following Myocardial Infarction

Fan, Min 01 August 2021 (has links)
Heart failure after myocardial infarction (MI) remains the leading cause of mortality among all cardiovascular diseases globally. Angiogenesis plays a critical role in cardiac functional recovery after MI. Heat shock protein A12B (HSPA12B) is predominately expressed in endothelial cells and required for angiogenesis. Yes-associated protein (YAP) has been reported to promote tumor angiogenesis. In the present study, we investigated the cooperative role of HSPA12B and YAP in angiogenesis following myocardial ischemic injury. Endothelial specific deficiency of HSPA12B (eHspa12b-/-) or YAP (eYap-/-) impairs angiogenesis and exacerbates cardiac dysfunction after MI, when compared with wild type (WT) mice. In addition, MI induced angiogenesis and the expression of angiogenic factors (angiopoietin-1, VEGF and VEGFR2) were impaired in both eHspa12b-/- and eYap-/- hearts. MI increased YAP expression and nuclear translocation in WT hearts, but not in eHspa12b-/- myocardium. Similarly, MI also markedly increased HSPA12B expression and nuclear translocation in WT mice but not in eYap-/- hearts. In vitro data shows that overexpression of HSPA12B upregulated hypoxia induced endothelial cell proliferation, migration and angiogenesis. On the contrary, deactivation of YAP by verteporfin attenuates endothelial cell proliferation, migration and angiogenesis after hypoxic challenge. In accordance, silencing of either HSPA12B or YAP suppressed endothelial cell proliferation and angiogenesis promoted by hypoxia. Importantly, YAP inhibition abrogates HSPA12B induced endothelial cell proliferation and angiogenesis. Deficiency of HSPA12B suppresses YAP expression and nuclear translocation following hypoxia while knockdown of YAP attenuates hypoxia stimulated HSPA12B expression and nuclear translocation. Mechanistically, hypoxia induced an interaction between endothelial HSPA12B and YAP. Of note, ChIP assay shows that HSPA12B is a target gene of YAP/transcriptional enhanced associated domain 4 (TEAD4). Further investigation indicates that HSPA12B also acts as a co-activator in YAP associated proliferation and angiogenesis. HSPA12B can stabilize YAP and prevent YAP from degradation. Therefore, our results delineated a previously unrecognized role of endothelial HSPA12B as a novel target and co-activator for YAP/TEAD4 and cooperates with YAP to promote endothelial cell proliferation, migration and angiogenesis following myocardial ischemia.
16

Lactate Suppresses Macrophage Pro-Inflammatory Response to LPS Stimulation by Inhibition of YAP and NF-κB Activation via GPR81-Mediated Signaling

Yang, Kun, Xu, Jingjing, Fan, Min, Tu, Fei, Wang, Xiaohui, Ha, Tuanzhu, Williams, David L., Li, Chuanfu 06 October 2020 (has links)
Recent evidence from cancer research indicates that lactate exerts a suppressive effect on innate immune responses in cancer. This study investigated the mechanisms by which lactate suppresses macrophage pro-inflammatory responses. Macrophages [Raw 264.7 and bone marrow derived macrophages (BMDMs)] were treated with LPS in the presence or absence of lactate. Pro-inflammatory cytokines, NF-κB and YAP activation and nuclear translocation were examined. Our results show that lactate significantly attenuates LPS stimulated macrophage TNF-α and IL-6 production. Lactate also suppresses LPS stimulated macrophage NF-κB and YAP activation and nuclear translocation in macrophages. Interestingly, YAP activation and nuclear translocation are required for LPS stimulated macrophage NF-κB activation and TNFα production. Importantly, lactate suppressed YAP activation and nuclear translocation is mediated by GPR81 dependent AMKP and LATS activation which phosphorylates YAP, resulting in YAP inactivation. Finally, we demonstrated that LPS stimulation induces an interaction between YAP and NF-κB subunit p65, while lactate decreases the interaction of YAP and NF-κB, thus suppressing LPS induced pro-inflammatory cytokine production. Our study demonstrates that lactate exerts a previously unknown role in the suppression of macrophage pro-inflammatory cytokine production via GPR81 mediated YAP inactivation, resulting in disruption of YAP and NF-κB interaction and nuclear translocation in macrophages.
17

Immuno-Labeling of Yes-associated Protein in the Crystalline Lens

Grant, Edwin Arthur 23 September 2016 (has links)
No description available.
18

Social media analysis for product safety using text mining and sentiment analysis

Isa, H., Trundle, Paul R., Neagu, Daniel January 2014 (has links)
No / The growing incidents of counterfeiting and associated economic and health consequences necessitate the development of active surveillance systems capable of producing timely and reliable information for all stake holders in the anti-counterfeiting fight. User generated content from social media platforms can provide early clues about product allergies, adverse events and product counterfeiting. This paper reports a work in progress with contributions including: the development of a framework for gathering and analyzing the views and experiences of users of drug and cosmetic products using machine learning, text mining and sentiment analysis; the application of the proposed framework on Facebook comments and data from Twitter for brand analysis, and the description of how to develop a product safety lexicon and training data for modeling a machine learning classifier for drug and cosmetic product sentiment prediction. The initial brand and product comparison results signify the usefulness of text mining and sentiment analysis on social media data while the use of machine learning classifier for predicting the sentiment orientation provides a useful tool for users, product manufacturers, regulatory and enforcement agencies to monitor brand or product sentiment trends in order to act in the event of sudden or significant rise in negative sentiment.
19

Modelling and stochastic simulation of synthetic biological Boolean gates

Sanassy, D., Fellerman, H., Krasnogor, N., Konur, Savas, Mierla, L.M., Gheorghe, Marian, Ladroue, C., Kalvala, S. January 2014 (has links)
No / Synthetic Biology aspires to design, compose and engineer biological systems that implement specified behaviour. When designing such systems, hypothesis testing via computational modelling and simulation is vital in order to reduce the need of costly wet lab experiments. As a case study, we discuss the use of computational modelling and stochastic simulation for engineered genetic circuits that implement Boolean AND and OR gates that have been reported in the literature. We present performance analysis results for nine different state-of-the-art stochastic simulation algorithms and analyse the dynamic behaviour of the proposed gates. Stochastic simulations verify the desired functioning of the proposed gate designs.
20

Evaluating the duration of increased milking frequency during early lactation for increased yield through lactation

Tate, Kaley Renee 11 July 2018 (has links)
Increasing the milking frequency of early lactation dairy cows increases their milk yield, both during increased milking and after the cows are returned to a normal twice-daily milking schedule. When milked four times a day (4X) for only the first twenty-one days of lactation, the right udder half produces 3 kg/d more milk than the left half, which is milked only two times a day (2X) over the course of lactation (Hale et al., 2003). Alterations to this increased milking frequency (IMF) approach have been investigated in order to maximize production of the animals and determine the most efficient practice for producers. The aim of this study was to determine the appropriate duration of early lactation IMF treatment by increasing milking frequency of early lactation cows for various lengths of time, and subsequently increasing the use of this management practice on Virginia dairy farms. The right udder half of twenty-three primiparous and multiparous Holstein cows were milked 4X for 10, 20, or 40 days at the beginning of lactation, and the left udder half 2X for the entire lactation. Udder-half milk yields were measured at various time points throughout lactation and used to calculate the difference between right (4X) and left (2X) udder halves. Overall, treatment did not have a significant effect on milk yield difference throughout the entire lactation; the udder half differences for each group were -0.45 kg, 1.92 kg and 4.62 kg for the 10 d, 20 d and 40 d treatments (P > 0.05). In addition to the IMF portion of the experiment, two different methodologies were used to investigate the possible mechanism of local regulation of milk yield in response to IMF treatment. Milk fatty acid analysis was performed on milk samples obtained from the above experiment. Three different groups of fatty acids were analyzed to detect potential changes in the right udder half (4X) when compared to the left (2X); the three groups were denovo, C16, and preformed fatty acids. There was no significant effect of treatment on fatty acid composition of right and left udder halves for any of the three groups (P > 0.05). The second methodology used to explore a possible mechanism behind increased milk yield following IMF treatment was immunohistochemistry of mammary gland tissue samples obtained after IMF treatment in a previous experiment. The key target investigated was a component of the Hippo signaling pathway, Yes-associated protein (YAP). Intensity of YAP staining in the cytoplasmic area of mammary epithelial cells (MEC) and number of YAP-positive stained nuclei located in the MEC were quantified for each of the images obtained. There was no effect of treatment or day on intensity of staining (P > 0.05) with no difference in the intensity of staining between 4X and 2X samples or d 21 and d 60 samples. However, the interaction for treatment x day tended to be significant (P < 0.06), with the d 60 samples tending to have higher intensity of staining than d 21 samples. For YAP-positive nuclei, there was a significant effect of day (P < 0.05), with d 60 samples having significantly more YAP positive nuclei. There was not a significant effect of treatment or treatment x day interaction (P > 0.05) with 2X and 4X samples having the same number of YAP positive nuclei. Results from the first experiment reveal that 40 d of IMF during early lactation is sufficient to produce an increase in milk and component yields throughout lactation. This practice could be implemented on Virginia dairy farms as a way to increase efficiency and milk yield per cow. Results from the second half of this research indicates that further research is needed to investigate the fatty acid content of milk from cows subject to IMF treatment during early lactation. In addition, YAP potentially plays a role in the changes occurring in the mammary gland, with increased intensity of YAP staining and increased number of YAP positive nuclei observed at 60 DIM. Understanding of this protein and its involvement in the mammary gland could lead to identifying a mechanism for which this increase in milk yield and components following IMF is occurring. Further research needs to be done to provide results supporting the current experiment. / MSLFS / The focus of this study is increasing milk yield by increasing milking frequency of early lactation cows. We will use a technique where each half of the cow's udder is milked with different milking frequencies. Previous studies have shown an increase in milk yield due to increased milking frequency. When milked four times a day for 21 days, the right udder half produced 2,032 lb. more milk than the left over the course of a lactation. This project will investigate modifications to the 21-day increase in milking frequency that might increase the use of this management practice on Virginia dairy farms. This experiment will determine the increase in milk yield when cows are milked four times a day for 10, 20, or 40 days. Farmers are concerned about return on investment - including time invested engaging extra milkings. This experiment will determine the effective duration of increased milking frequency needed to gain an increase in milk production with the minimum investment of time necessary to apply increased milking frequency - can the increase achieved with 20 days be achieved in only 10 or does increasing to 40 days provide an even greater benefit than 20-day application?

Page generated in 0.0332 seconds