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  • 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.
61

都市固體廢棄物減量之經濟分析

蔡月蜜, Tasi, Yue-Mi Unknown Date (has links)
世界各國面對垃圾量隨時間而逐漸上升的情形,原本皆視為必然趨勢,因此不斷地提供垃圾服務的供給來滿足家戶需求,以求達到均衡,這可說是「需求創造供給」。但是,一旦供給不足,在缺乏價格機能調節下,均衡將不復存在,於是降低家戶對垃圾服務需求的政策始被提出並被採行。另有一些研究則是瞭解人對環境的認知、態度與行為之間的關連性,許多研究發現其間關係為對環境知識瞭解愈詳細並傾向於新生態典範者,其行為表現就愈環保且較有積極的垃圾減量的行為,此為除了實施降低家戶對垃圾服務需求政策外另可同時進行的方向。 台灣目前已採用隨水量徵收垃圾清除處理費來反應各縣市政府在處理垃圾時的成本,不過因為此收費方式不是依垃圾量的多寡來收取,且家戶通常在繳交水費時無特別察覺到此筆費用,因此不會有付了清除費的感受,所以台灣近年來有幾個都市採行了減少家戶對垃圾服務需求方面的政策。此類政策大多分為兩種,一為行政命令式的強制回收;另一則是隨垃圾量收取垃圾費。台中市自民國88年7月1日首先實施「強制垃圾分類」,台北市則於民國89年7月1日實施「垃圾費隨袋徵收」制度,而今年1月1日,高雄市也採行了與台中市相同的政策,藉此來提高資源回收量、降低垃圾量。 本研究以一代表性家戶追求最大化效用,但受限於居住地的垃圾管理政策之條件,用比較靜態方式來分析在「無任何降低家戶對垃圾服務需求的政策」、「強制垃圾分類」、「垃圾費隨袋徵收」相異制度下,對家戶的垃圾源頭減量行為及垃圾丟棄量、非法傾倒量、資源回收量的影響。結果只有「隨袋徵收」具源頭減量效果,但是非法傾倒量也最多。若家戶只能以非法傾倒或合法丟棄兩種方式來處理垃圾時,那麼台中市、高雄市不會有非法傾倒的情形,但是台北市一定會有。而如果家戶只能在非法傾倒、從事回收間做抉擇,則台中市、高雄市會比台北市願意多做分類工作。至於若只有合法丟棄與回收間兩種可能性時,則要視其分類不完善的預期罰金與垃圾袋費用孰高來決定兩種制度下何者的回收量較高。 實證分析則得到對環境及垃圾管理認知、態度與日常環保行為愈正向者,其家戶會多花點兒心力於垃圾分類且垃圾量也較少。實施「強制垃圾分類」與「隨袋徵收」的地區,回收時間有顯著性地增加。但是對於減少垃圾容量,「隨袋徵收」才有顯著性的效果。本研究純粹探討制度不同對家戶減量行為的效果,而無分析不同政策的成本面,因此,環保單位應就欲達目的擇一適合的垃圾管理政策。 / The amount of household solid waste that is constantly rising with time has been an inevitable trend. In order to reach the equilibrium, the governments all over the world initially supply the solid waste disposal services freely to fulfill the demand. However, once the cost of supply has grown to such an extent that supply falls short, the equilibrium will be impossible to reach. Thus, many governments have changed the policy of providing free disposal service and developed alternative approaches to lower household’s demand for the service. In the meantime, some researches have studied the links between human perceptions, value, attitude and behavior toward the environment. Much of the research points to the fact that, the more detailed knowledge of the environment people hold, the more of New Environment Paradigm (NEP) they are, the more likely they are to actively reduce their waste and promote green behavior. This is one other route we can take to reduce household demand of solid waste services. The waste disposal fee is charged according to the amount of water used by the household to cover the cost of waste collection and disposal in Taiwan. However, this charge scheme doesn’t relate the fee paid by a household to the amount of waste the household discard, and most households are thereby indifferent to the payment of waste fee. In recent years, several cities have undertaken alternative policy schemes to reduce the household demands for waste disposal service. These schemes mainly come in two ways:one is to charge fees according to the quantity of waste generated; the other is to enforce the mandatory recycling law. Since July 1st, 1999, Tai-Chung City has required households to separate the waste into recyclable and disposable while Taipei City had chosen the latter fashion - waste fee per bag since July 1st, 2000. Kaohsiung City, on the other hand, has performed the same scheme as Tai-Chung City beginning January 1st, 2001. This study first develops a theoretical model of household disposal decision under different waste management policies:“no policy”, “required waste separation and recycling”, and “fee per-bag”. The household can choose among various options, including waste reduction, recycling, regular garbage collection and illegal dumping (or burning). The model shows that the “fee per-bag” is the only effective solution to source reduction; however, it induces the most illegal garbage dumping among the three schemes. In fact, the incidents of illegal dumping did not take place in Tai-Chung or Kaohsiung cities but was found in Taipei City. When households can only choose between recycling and illegal dumping, then Tai-Chung and Kaohsiung city dwellers are more likely to do more separation and recycling work than Taipei’s. As for when only regular garbage collection and waste separation and recycling are available as in Tai-Chung and Kaohsiung cities, the households’ likelihood to recycle depends on the expected fines of incomplete separation. Empirical result shows that when people have more knowledge about the environment and waste management policy, greener attitude towards environment, they tend to put more effort into waste separation and recycling, and their waste generated will be less than other households. The time people spend to separate waste increases significantly in those areas that apply “required waste separation” and “fee per-bag” programs. “Fee per-bag” has resulted in the largest decreases in the volume of the garbage.
62

Organisation, practice and experiences of mouth hygiene in stroke unit care: a mixed methods study

Horne, Maria, McCracken, G., Walls, A., Tyrrell, P.J., Smith, C.J. 03 1900 (has links)
No / Aims and objectives To (1) investigate the organisation, provision and practice of oral care in typical UK stroke units; (2) explore stroke survivors', carers' and healthcare professionals' experiences and perceptions about the barriers and facilitators to receiving and undertaking oral care in stroke units. Cerebrovascular disease and oral health are major global health concerns. Little is known about the provision, challenges and practice of oral care in the stroke unit setting, and there are currently no evidence-based practice guidelines. Design Cross-sectional survey of 11 stroke units across Greater Manchester and descriptive qualitative study using focus groups and semi-structured interviews. Methods A self-report questionnaire was used to survey 11 stroke units in Greater Manchester. Data were then collected through two focus groups (n = 10) with healthcare professionals and five semi-structured interviews with stroke survivors and carers. Focus group and interview data were recorded, transcribed verbatim and analysed using framework approach. Results Eleven stroke units in Greater Manchester responded to the survey. Stroke survivors and carers identified a lack of oral care practice and enablement by healthcare professionals. Healthcare professionals identified a lack of formal training to conduct oral care for stroke patients, inconsistency in the delivery of oral care and no set protocols or use of formal oral assessment tools. Conclusion Oral care post-stroke could be improved by increasing healthcare professionals' awareness, understanding and knowledge of the potential health benefits of oral care post-stroke. Further research is required to develop and evaluate the provision of oral care in stroke care to inform evidence-based education and practice.
63

O envolvimento da proteína adaptadora 1 (AP-1) no mecanismo de regulação negativa do receptor CD4 por Nef de HIV-1 / The involvement of Adaptor Protein 1 (AP-1) on the Mechanism of CD4 Down-regulation by Nef from HIV-1

Tavares, Lucas Alves 05 August 2016 (has links)
O Vírus da Imunodeficiência Humana (HIV) é o agente etiológico da Síndrome da Imunodeficiência Adquirida (AIDS). A AIDS é uma doença de distribuição mundial, e estima-se que existam atualmente pelo menos 36,9 milhões de pessoas infectadas com o vírus. Durante o seu ciclo replicativo, o HIV promove diversas alterações na fisiologia da célula hospedeira a fim de promover sua sobrevivência e potencializar a replicação. A rápida progressão da infecção pelo HIV-1 em humanos e em modelos animais está intimamente ligada à função da proteína acessória Nef. Dentre as diversas ações de Nef está a regulação negativa de proteínas importantes na resposta imunológica, como o receptor CD4. Sabe-se que esta ação resulta da indução da degradação de CD4 em lisossomos, mas os mecanismos moleculares envolvidos ainda são totalmente elucidados. Nef forma um complexo tripartite com a cauda citosólica de CD4 e a proteína adaptadora 2 (AP-2), em vesículas revestidas por clatrina nascentes, induzindo a internalização e degradação lisossomal de CD4. Pesquisas anteriores demonstraram que o direcionamento de CD4 aos lisossomos por Nef envolve a entrada do receptor na via dos corpos multivesiculares (MVBs), por um mecanismo atípico, pois, embora não necessite da ubiquitinação de carga, depende da ação de proteínas que compõem os ESCRTs (Endosomal Sorting Complexes Required for Transport) e da ação de Alix, uma proteína acessória da maquinaria ESCRT. Já foi reportado que Nef interage com subunidades dos complexos AP-1, AP-2, AP-3 e Nef não parece interagir com subunidades de AP-4 e AP-5. Entretanto, o papel da interação de Nef com AP-1 e AP-3 na regulação negativa de CD4 ainda não está totalmente elucidado. Ademais, AP-1, AP-2 e AP-3 são potencialmente heterogêneos devido à existência de isoformas múltiplas das subunidades codificadas por diferentes genes. Todavia, existem poucos estudos para demonstrar se as diferentes combinações de isoformas dos APs são formadas e se possuem propriedades funcionais distintas. O presente trabalho procurou identificar e caracterizar fatores celulares envolvidos na regulação do tráfego intracelular de proteínas no processo de regulação negativa de CD4 induzido por Nef. Mais especificamente, este estudo buscou caracterizar a participação do complexo AP-1 na modulação negativa de CD4 por Nef de HIV-1, através do estudo funcional das duas isoformas de ?-adaptina, subunidades de AP-1. Utilizando a técnica de Pull-down demonstramos que Nef é capaz de interagir com ?2. Além disso, nossos dados de Imunoblot indicaram que a proteína ?2-adaptina, e não ?1-adaptina, é necessária no processo de degradação lisossomal de CD4 por Nef e que esta participação é conservada para degradação de CD4 por Nef de diferentes cepas virais. Ademais, por citometria de fluxo, o silenciamento de ?2, e não de ?1, compromete a diminuição dos níveis de CD4 por Nef da membrana plasmática. A análise por imunofluorêsncia indireta também revelou que a diminuição dos níveis de ?2 impede a redistribuição de CD4 por Nef para regiões perinucleares, acarretando no acúmulo de CD4, retirados por Nef da membrana plasmática, em endossomos primários. A depleção de ?1A, outra subunidade de AP-1, acarretou na diminuição dos níveis celulares de ?2 e ?1, bem como, no comprometimento da eficiente degradação de CD4 por Nef. Além disso, foi possível observar que, ao perturbar a maquinaria ESCRT via super-expressão de HRS (uma subunidade do complexo ESCRT-0), ocorreu um acumulo de ?2 em endossomos dilatados contendo HRS-GFP, nos quais também detectou-se CD4 que foi internalizado por Nef. Em conjunto, os resultados indicam que ?2-adaptina é uma importante molécula para o direcionamento de CD4 por Nef para a via ESCRT/MVB, mostrando ser uma proteína relevante no sistema endo-lisossomal. Ademais, os resultados indicaram que as isoformas ?-adaptinas não só possuem funções distintas, mas também parecem compor complexos AP-1 com diferentes funções celulares, já que apenas a variante AP-1 contendo ?2, mas não ?1, participa da regulação negativa de CD4 por Nef. Estes estudos contribuem para o melhor entendimento dos mecanismos moleculares envolvidos na atividade de Nef, que poderão também ajudar na melhor compreensão da patogênese do HIV e da síndrome relacionada. Em adição, este trabalho contribui para o entendimento de processos fundamentais da regulação do tráfego de proteínas transmembrana no sistema endo-lisossomal. / The Human Immunodeficiency Virus (HIV) is the etiologic agent of Acquired Immunodeficiency Syndrome (AIDS). AIDS is a disease which has a global distribution, and it is estimated that there are currently at least 36.9 million people infected with the virus. During the replication cycle, HIV promotes several changes in the physiology of the host cell to promote their survival and enhance replication. The fast progression of HIV-1 in humans and animal models is closely linked to the function of an accessory protein Nef. Among several actions of Nef, one is the most important is the down-regulation of proteins from the immune response, such as the CD4 receptor. It is known that this action causes CD4 degradation in lysosome, but the molecular mechanisms are still incompletely understood. Nef forms a tripartite complex with the cytosolic tail of the CD4 and adapter protein 2 (AP-2) in clathrin-coated vesicles, inducing CD4 internalization and lysosome degradation. Previous research has demonstrated that CD4 target to lysosomes by Nef involves targeting of this receptor to multivesicular bodies (MVBs) pathway by an atypical mechanism because, although not need charging ubiquitination, depends on the proteins from ESCRTs (Endosomal Sorting Complexes Required for Transport) machinery and the action of Alix, an accessory protein ESCRT machinery. It has been reported that Nef interacts with subunits of AP- 1, AP-2, AP-3 complexes and Nef does not appear to interact with AP-4 and AP-5 subunits. However, the role of Nef interaction with AP-1 or AP-3 in CD4 down-regulation is poorly understood. Furthermore, AP-1, AP-2 and AP-3 are potentially heterogeneous due to the existence of multiple subunits isoforms encoded by different genes. However, there are few studies to demonstrate if the different combinations of APs isoforms are form and if they have distinct functional properties. This study aim to identify and characterize cellular factors involved on CD4 down-modulation induced by Nef from HIV-1. More specifically, this study aimed to characterize the involvement of AP-1 complex in the down-regulation of CD4 by Nef HIV-1 through the functional study of the two isoforms of ?-adaptins, AP-1 subunits. By pull-down technique, we showed that Nef is able to interact with ?2. In addition, our data from immunoblots indicated that ?2- adaptin, not ?1-adaptin, is required in Nef-mediated targeting of CD4 to lysosomes and the ?2 participation in this process is conserved by Nef from different viral strains. Furthermore, by flow cytometry assay, ?2 depletion, but not ?1 depletion, compromises the reduction of surface CD4 levels induced by Nef. Immunofluorescence microscopy analysis also revealed that ?2 depletion impairs the redistribution of CD4 by Nef to juxtanuclear region, resulting in CD4 accumulation in primary endosomes. Knockdown of ?1A, another subunit of AP-1, resulted in decreased cellular levels of ?1 and ?2 and, compromising the efficient CD4 degradation by Nef. Moreover, upon artificially stabilizing ESCRT-I in early endosomes, via overexpression of HRS, internalized CD4 accumulates in enlarged HRS-GFP positive endosomes, where co-localize with ?2. Together, the results indicate that ?2-adaptin is a molecule that is essential for CD4 targeting by Nef to ESCRT/MVB pathway, being an important protein in the endo-lysosomal system. Furthermore, the results indicate that ?-adaptins isoforms not only have different functions, but also seem to compose AP-1 complex with distinct cell functions, and only the AP-1 variant comprising ?2, but not ?1, acts in the CD4 down-regulation induced by Nef. These studies contribute to a better understanding on the molecular mechanisms involved in Nef activities, which may also help to improve the understanding of the HIV pathogenesis and the related syndrome. In addition, this work contributes with the understanding of primordial process regulation on intracellular trafficking of transmembrane proteins.
64

O envolvimento da proteína adaptadora 1 (AP-1) no mecanismo de regulação negativa do receptor CD4 por Nef de HIV-1 / The involvement of Adaptor Protein 1 (AP-1) on the Mechanism of CD4 Down-regulation by Nef from HIV-1

Lucas Alves Tavares 05 August 2016 (has links)
O Vírus da Imunodeficiência Humana (HIV) é o agente etiológico da Síndrome da Imunodeficiência Adquirida (AIDS). A AIDS é uma doença de distribuição mundial, e estima-se que existam atualmente pelo menos 36,9 milhões de pessoas infectadas com o vírus. Durante o seu ciclo replicativo, o HIV promove diversas alterações na fisiologia da célula hospedeira a fim de promover sua sobrevivência e potencializar a replicação. A rápida progressão da infecção pelo HIV-1 em humanos e em modelos animais está intimamente ligada à função da proteína acessória Nef. Dentre as diversas ações de Nef está a regulação negativa de proteínas importantes na resposta imunológica, como o receptor CD4. Sabe-se que esta ação resulta da indução da degradação de CD4 em lisossomos, mas os mecanismos moleculares envolvidos ainda são totalmente elucidados. Nef forma um complexo tripartite com a cauda citosólica de CD4 e a proteína adaptadora 2 (AP-2), em vesículas revestidas por clatrina nascentes, induzindo a internalização e degradação lisossomal de CD4. Pesquisas anteriores demonstraram que o direcionamento de CD4 aos lisossomos por Nef envolve a entrada do receptor na via dos corpos multivesiculares (MVBs), por um mecanismo atípico, pois, embora não necessite da ubiquitinação de carga, depende da ação de proteínas que compõem os ESCRTs (Endosomal Sorting Complexes Required for Transport) e da ação de Alix, uma proteína acessória da maquinaria ESCRT. Já foi reportado que Nef interage com subunidades dos complexos AP-1, AP-2, AP-3 e Nef não parece interagir com subunidades de AP-4 e AP-5. Entretanto, o papel da interação de Nef com AP-1 e AP-3 na regulação negativa de CD4 ainda não está totalmente elucidado. Ademais, AP-1, AP-2 e AP-3 são potencialmente heterogêneos devido à existência de isoformas múltiplas das subunidades codificadas por diferentes genes. Todavia, existem poucos estudos para demonstrar se as diferentes combinações de isoformas dos APs são formadas e se possuem propriedades funcionais distintas. O presente trabalho procurou identificar e caracterizar fatores celulares envolvidos na regulação do tráfego intracelular de proteínas no processo de regulação negativa de CD4 induzido por Nef. Mais especificamente, este estudo buscou caracterizar a participação do complexo AP-1 na modulação negativa de CD4 por Nef de HIV-1, através do estudo funcional das duas isoformas de ?-adaptina, subunidades de AP-1. Utilizando a técnica de Pull-down demonstramos que Nef é capaz de interagir com ?2. Além disso, nossos dados de Imunoblot indicaram que a proteína ?2-adaptina, e não ?1-adaptina, é necessária no processo de degradação lisossomal de CD4 por Nef e que esta participação é conservada para degradação de CD4 por Nef de diferentes cepas virais. Ademais, por citometria de fluxo, o silenciamento de ?2, e não de ?1, compromete a diminuição dos níveis de CD4 por Nef da membrana plasmática. A análise por imunofluorêsncia indireta também revelou que a diminuição dos níveis de ?2 impede a redistribuição de CD4 por Nef para regiões perinucleares, acarretando no acúmulo de CD4, retirados por Nef da membrana plasmática, em endossomos primários. A depleção de ?1A, outra subunidade de AP-1, acarretou na diminuição dos níveis celulares de ?2 e ?1, bem como, no comprometimento da eficiente degradação de CD4 por Nef. Além disso, foi possível observar que, ao perturbar a maquinaria ESCRT via super-expressão de HRS (uma subunidade do complexo ESCRT-0), ocorreu um acumulo de ?2 em endossomos dilatados contendo HRS-GFP, nos quais também detectou-se CD4 que foi internalizado por Nef. Em conjunto, os resultados indicam que ?2-adaptina é uma importante molécula para o direcionamento de CD4 por Nef para a via ESCRT/MVB, mostrando ser uma proteína relevante no sistema endo-lisossomal. Ademais, os resultados indicaram que as isoformas ?-adaptinas não só possuem funções distintas, mas também parecem compor complexos AP-1 com diferentes funções celulares, já que apenas a variante AP-1 contendo ?2, mas não ?1, participa da regulação negativa de CD4 por Nef. Estes estudos contribuem para o melhor entendimento dos mecanismos moleculares envolvidos na atividade de Nef, que poderão também ajudar na melhor compreensão da patogênese do HIV e da síndrome relacionada. Em adição, este trabalho contribui para o entendimento de processos fundamentais da regulação do tráfego de proteínas transmembrana no sistema endo-lisossomal. / The Human Immunodeficiency Virus (HIV) is the etiologic agent of Acquired Immunodeficiency Syndrome (AIDS). AIDS is a disease which has a global distribution, and it is estimated that there are currently at least 36.9 million people infected with the virus. During the replication cycle, HIV promotes several changes in the physiology of the host cell to promote their survival and enhance replication. The fast progression of HIV-1 in humans and animal models is closely linked to the function of an accessory protein Nef. Among several actions of Nef, one is the most important is the down-regulation of proteins from the immune response, such as the CD4 receptor. It is known that this action causes CD4 degradation in lysosome, but the molecular mechanisms are still incompletely understood. Nef forms a tripartite complex with the cytosolic tail of the CD4 and adapter protein 2 (AP-2) in clathrin-coated vesicles, inducing CD4 internalization and lysosome degradation. Previous research has demonstrated that CD4 target to lysosomes by Nef involves targeting of this receptor to multivesicular bodies (MVBs) pathway by an atypical mechanism because, although not need charging ubiquitination, depends on the proteins from ESCRTs (Endosomal Sorting Complexes Required for Transport) machinery and the action of Alix, an accessory protein ESCRT machinery. It has been reported that Nef interacts with subunits of AP- 1, AP-2, AP-3 complexes and Nef does not appear to interact with AP-4 and AP-5 subunits. However, the role of Nef interaction with AP-1 or AP-3 in CD4 down-regulation is poorly understood. Furthermore, AP-1, AP-2 and AP-3 are potentially heterogeneous due to the existence of multiple subunits isoforms encoded by different genes. However, there are few studies to demonstrate if the different combinations of APs isoforms are form and if they have distinct functional properties. This study aim to identify and characterize cellular factors involved on CD4 down-modulation induced by Nef from HIV-1. More specifically, this study aimed to characterize the involvement of AP-1 complex in the down-regulation of CD4 by Nef HIV-1 through the functional study of the two isoforms of ?-adaptins, AP-1 subunits. By pull-down technique, we showed that Nef is able to interact with ?2. In addition, our data from immunoblots indicated that ?2- adaptin, not ?1-adaptin, is required in Nef-mediated targeting of CD4 to lysosomes and the ?2 participation in this process is conserved by Nef from different viral strains. Furthermore, by flow cytometry assay, ?2 depletion, but not ?1 depletion, compromises the reduction of surface CD4 levels induced by Nef. Immunofluorescence microscopy analysis also revealed that ?2 depletion impairs the redistribution of CD4 by Nef to juxtanuclear region, resulting in CD4 accumulation in primary endosomes. Knockdown of ?1A, another subunit of AP-1, resulted in decreased cellular levels of ?1 and ?2 and, compromising the efficient CD4 degradation by Nef. Moreover, upon artificially stabilizing ESCRT-I in early endosomes, via overexpression of HRS, internalized CD4 accumulates in enlarged HRS-GFP positive endosomes, where co-localize with ?2. Together, the results indicate that ?2-adaptin is a molecule that is essential for CD4 targeting by Nef to ESCRT/MVB pathway, being an important protein in the endo-lysosomal system. Furthermore, the results indicate that ?-adaptins isoforms not only have different functions, but also seem to compose AP-1 complex with distinct cell functions, and only the AP-1 variant comprising ?2, but not ?1, acts in the CD4 down-regulation induced by Nef. These studies contribute to a better understanding on the molecular mechanisms involved in Nef activities, which may also help to improve the understanding of the HIV pathogenesis and the related syndrome. In addition, this work contributes with the understanding of primordial process regulation on intracellular trafficking of transmembrane proteins.

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