• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 313
  • 53
  • 16
  • 16
  • 16
  • 16
  • 16
  • 16
  • 15
  • 13
  • 7
  • 5
  • 5
  • 5
  • 5
  • Tagged with
  • 476
  • 476
  • 132
  • 69
  • 50
  • 38
  • 33
  • 32
  • 31
  • 29
  • 28
  • 27
  • 27
  • 26
  • 26
  • 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.
31

O enfrentamento de epidemias : as estrategias e perspectivas do controle do dengue

Donalisio, Maria Rita de Camargo 01 September 1995 (has links)
Orientador: Luiz Jacintho da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-20T15:22:00Z (GMT). No. of bitstreams: 1 Donalisio_MariaRitadeCamargo_D.pdf: 10399849 bytes, checksum: f51728baa3ca2a2afe04775260d82cff (MD5) Previous issue date: 1995 / Resumo: As epidemias podem ser examinadas sob. diferentes perspectivas, que exigem universos explicativos e metodológicos distintos, com diversos raios de visão e instrumentos de análise. Dentro de cada uma destas perspectivas, foram avaliadas as possibilidades de controle da epidemia de Dengue. Na sua dimensão biológica-ecológica (Mundo da Materialidade), as epidemias carregam particularidades do micro universo orgânico e clínico, da medida do tempo e do espaço biológico da relação do parasita, do hospedeiro e do "meio ambiente". Esta dimensão tem um horizonte de visibilidade próprio, onde está à disposição um arsenal tecnológico de grande utilidade para o enfrentamento da transmissão. Neste trabalho foram recuperadas experiências epidêmicas de outros países que deixam lições sobre o comportamento biológico e epidemiológico da doença. Diante de uma epidemia, a sociedade mostra como vê e simboliza a sua ocorrência (Mundo" da Subjetividade). Desastroso é o programa de controle e prevenção de um surto que não leva em consideração as questões subjetivas do que significa previnir-se, adoecer, ou ser um individuo transmissor. As epidemias têm uma historicidade e são determinadas pela estrutura social, (organização do espaço, movimentos populacionais), além de softer influência das práticas de intervenção e controle que a sociedade adota para enfrenta-las (Munda das Relações Sociais). Foi estudado o dengue no espaço urbano, identificando os,deslocamentos populacionais e as rotas de comércio e da riqueza, como estratégicos para explicar a disseminação da doença. Foram apontadas algumas lições das grandes campanhas do passado e a necessidade de repensar as estratégias para erradicação da doença hoje, na conjuntura da descentralização das ações de saúde pública e vigilância epidemiológica. A municipalização da vigilância epidemiológica e controle de vetores tem sido fundamental para ampliar a cobertura dos serviços e dar eficácia às medidas. Porém há necessidade de se reforçar os níveis regionais de controle e integrar as instâncias de combate às endemias e epidemias. Essas estratégias exigem planos regionais e macro-regionais articulados que dêm coerência às ações e maior racionalidade às medidas / Abstract: Epidemics may be examined under a variety of perspectives, that require distinct explanatory universes, each one with a different reach and distinguished analytical instruments. In the bio-ecological dimension (World of Materiality), the epidemic brings particularities from the micro-organic and clinical universe as well as from the relations between parasite, host and the environment. This dimension has a particular horizon of visibility, in which there is a technological arsenal of great utility for the control of the transmission. In this work, lessons were taken ftom the epidemiological behavior of Dengue epidemics ftom other countries. Facing an epidemic, society shows how it sees and symbolizes the event (World of Subjectivity). It is a disaster when a program of control and prevention of a disease outbreak doesn't consider questions like what it means to prevent, to get sick or to be the transmitting individual. Epidemics have a historicity and are determined by social structures (space organization and migration). Epidemics are also influenced by the interventionist practices and by the control methods used during the combat. (World of Social Relations). Dengue was studied in the urban context, identifying the population displacements and the commercial routes, as being strategic to explain the disease dissemination. 'Lessons from the past great eradication campaigns were pointed as well as the necessity to ponder the illness elimination in the context of health services decentralization. The municipalization of the epidemiological surveillance and of the vector control program has been fundamental to give efficacy to the health strategies. It's necessary though, to reinforce the role of the regional instances of health services and to integrate the combat to endemic and epidemics. This strategies requires macro-regional plans that brings coherence and rationality to the adopted control measures / Doutorado / Saude Coletiva / Doutor em Ciências Médicas
32

Development of vitellogenic competence in the fat body of the yellow fever mosquito, Aedes aegypti.

Flanagan, Thomas Raymond 01 January 1976 (has links) (PDF)
No description available.
33

Studies on growth-promoting proteins in fetal bovine serum using Aedes aegypti cells cultured in vitro /

Kuno, Goro. January 1971 (has links)
No description available.
34

Genealogia, distribuição e história de haplótipos do gene mitocondrial NADH 4 em populações do Aedes (Stegomyia) aegypti (Diptera: Culicidae) no Brasil / Genealogy, distribution and history of NADH4 haplotypes in Aedes (Stegomyia) aegypti (DIPTERA: CULICIDAE) populations from Brazil.

Bracco, José Eduardo 06 January 2005 (has links)
Informações sobre variabilidade intrapopulacional de vetores biológicos são críticas para o entendimento da transmissão de agentes infecciosos veiculados por esses organismos. Nesse sentido, o presente trabalho caracterizou a variabilidade de fragmento que codifica a subunidade 4 do gene mitocondrial da Nicotinamina Adenina Dinucleotideo Desidrogenase - NADH4 em populações de Aedes aegypti do Brasil e de outros países. Polimorfismos de nucleotídeos únicos foram detectados através da técnica de seqüenciamento genômico. As análises realizadas compreenderam a de variância molecular (AMOVA), clados agrupados (NCA), distribuição de diferenças pareadas. Paralelamente foram examinadas relações evolutivas entre os haplótipos com o emprego dos critérios de parcimônia máxima e verossimilhança máxima. Os resultados mostram que há polimorfismo do fragmento nas populações analisadas, levando à proposição de dois clados geneticamente independentes (monofiléticos). Inferências de caráter histórico suportam a hipótese de que um dos clados inclui seqüências de indivíduos de populações que chegaram às Américas durante os séculos XVII e XVIII pelo tráfico negreiro, e outro, formado por populações introduzidas mais recentemente, se originou de populações asiáticas. Possíveis implicações epidemiológicas da variabilidade genética apresentada pelas populações do Ae. aegypti são também discutidas. / Knowledge about intrapopulacional variation of biological vectors is critical for understanding the dynamics of the transmission of an infectious agent. The major objective of the present study is to characterize the variability of a gene fragment, which codes for the subunit 4 of the mitochondrial gene of the Nicotinamide Adenine Dinucleotide Dehydrogenase - NADH4 among Aedes aegypti populations from Brazil comparing with that of several other countries. Single nucleotide polymorphism was detected employing genomic sequencing techniques. Nucleotide sequences were analyzed using molecular variance (AMOVA), nested clade (NCA) and mismatch distribution methods. Additionally, evolutionary relationships among haplotypes were estimated employing maximum parsimony and maximum likelihood criterions. The results show that the fragment of the mitochondrial gene (NADH4) is polymorphic, and that the populations of Ae. aegypti from Brazil are grouped into two genetically distinct, monophyletic clades Historical inferences support the hypothesis that one clade includes sequences from individuals that may be introduced in the Americas in the 17th and 18th centuries during the slave trade from Africa to America. The second clade consists of sequences of individuals that may be introduced in Brazil more recent, probably from Asian populations. Epidemiological consequences because of the genetic variability among populations of Ae. aegypti in Brazil are discussed.
35

Avaliação farmacológica do extrato da glândula salivar de mosquito Aedes aegypti no prurido agudo e inflamação cutânea. / Pharmacologic evaluation of salivar gand extract from female Aedes aegypti mosquito in acute pruritus and skin inflammation.

Cerqueira, Anderson Romério Azevedo 02 February 2018 (has links)
O prurido (agudo e crônico) é uma sensação desagradável, que provoca o desejo ou o reflexo de coçar-se. Estima-se que 23 a 44 milhões de norte americanos sofrem com prurido, mas os dados epidemiológicos da frequência e as causas do prurido são escassos em vários países, incluindo Brasil. Os anti-histamínicos constituem os principais fármacos para tratar alergias e prurido provocado por picadas de insetos, mas são ineficazes conta o prurido idiopático, crônico e generalizado. Curiosamente, a exposição primária de humanos e animais à picada do mosquito fêmea Aedes aegypti (A. aegypti) não induz prurido, e pouco se sabe sobre este efeito. Neste contexto, este estudo caracterizou, via emprego de abordagens farmacológicas, o efeito do extrato da glândula salivar (EGS) do mosquito A. aegypti sobre o prurido (e inflamação cutânea relacionada) induzido por vias histaminérgicas (ou não) em pele dorsal de camundongos. A indução do prurido agudo (inflamação cutânea) foi feita pela injeção intradérmica (i.d) do composto 48/80 (C48/80), agonistas de Receptores Ativados por Protease -2 (PAR-2 (SLIGRL), receptores acoplados a proteína G do tipo mas (Mrgrp (cloroquina) e de potencial transitório TRPA1 e TRPV1 (allyl isothiocyanate e capsaicina, respectivamente) em Tyrode. O EGS do A. aegypti, (0,3 a 3 <font face = \"symbol\">mg/sitio, i.d.) inibiu o prurido, edema e influxo de células frente ao C48/80 em pele murina, mas não protegeu da desgranulação do mastócito in vitro, indicando que componentes bioativos no EGS inibem o prurido e a inflamação dependentes de vias histaminérgicas. O EGS reduziu parcialmente o prurido (ou inflamação neurogênica) induzido por SLIGRL, cloroquina, AITC ou capsaicina na pele murina, sugerindo que outros componentes bioativos afetam disparos nervosos pruriceptivos de vias não histaminérgicas. O estudo in vitro veio igualmente esclarecer que moléculas conservadas no EGS inibem respostas nervosas aos agonistas TRPV1 e TRPA1 em cultura de células de neurônios ou linhagem HEK293t transfectada (hTRPV1 e hTRPA1). Este estudo mostrou, pela primeira vez, a caracterização farmacológica anti-pruriceptiva (e anti-inflamatória) do EGS do mosquito fêmea A. aegypti, cujo mecanismo inclui vias sensível e resistente a histamina, podendo o EGS representar um nova ferramenta farmacológica com potencial para o controle do prurido. / Pruritus (acute and chronic) is an unpleasant sensation, which causes the desire or the reflex of scratching. It is estimated that 23 to 44 million Americans suffer from pruritus, but epidemiological data on pruritus frequency and its causes are scarce in several countries, including Brazil. Antihistamines are the main drugs to treat allergies and pruritus caused by insect bites, but they are ineffective to treat idiopathic, chronic and generalized pruritus. Interestingly, a primary exposure of humans and animals to the bite of the female mosquito Aedes aegypti (A. aegypti) does not induce pruritus, and little is known about this effect. In this context, this study characterized, through the use of pharmacological approaches, the effect of the salivary gland extract (EGS) of the A. aegypti mosquito on pruritus (and related cutaneous inflammation) induced by histaminergic or non histaminergic pathways in the dorsal skin of mice. The induction of acute pruritus (and or cutaneous inflammation) was produced by the intradermal (i.d.) injection of compound 48/80 (C48/80), agonists Protease Activated Receptor -2 (PAR-2 (SLIGRL), mas-related G protein-coupled receptor (Mrgrp (chloroquine) and transient receptor potential TRPA1 and TRPV1 (allyl isothiocyanate and capsaicin, respectively) diluted in Tyrode. The A. aegypti SGE, (0.3 to 3 <font face = \"symbol\">mg/site, id) significantly inhibited pruritus, edema and neutrophil influx evoked by C48/80 in murine skin, but it did not protect against mast cell degranulation in vivo and in vitro. This suggests that EGS bioactive components inhibit pruritus and inflammation via mechanism dependent on histaminergic pathways. SGE partially reduced SLIGRL, chloroquine, AITC-induced pruritus, or capsaicin-induced neurogenic inflammation in murine skin, suggesting that SGE bioactive components affect pruriceptive nerve firing independently of histaminergic pathways. The in vitro study also clarified that conserved SGE molecules inhibit nerve responses to TRPV1 and TRPA1 agonists in cultured neurons of dorsal root ganglia or transfected HEK293t lineage (hTRPV1 and hTRPA1). This study showed, for the first time, the anti-pruriceptive (and anti-inflammatory) pharmacological characterization of the EGS from the A. aegypti female mosquito, whose mechanism includes sensitive and histamine-resistant pathways. EGS may represents a new pharmacological tool with potential to treat pruritus.
36

Estrutura da vigilância em dengue no município de Mogi das Cruzes, SP, no período de 2003 a 2007 / Structure of vigilance in Dengue in Mogi das Cruzes city, SP, in period of 2003 until 2007

Suzuki, Selma Lina 06 February 2009 (has links)
Introdução. A dengue é uma doença reemergente preocupante para a saúde pública. O seu agente, Aedes aegypti, é a principal espécie responsável pela transmissão do vírus da dengue. Atualmente a Organização Mundial da Saúde (OMS) estima que entre 50 a 100 milhões de pessoas se infectem anualmente em países de todos os continentes com exceção da Europa. Objetivo. Descrever e conhecer a estrutura dos serviços de controle do Aedes aegypti e os aspectos epidemiológicos da dengue no município de Mogi das Cruzes, São Paulo. Métodos. A área de estudo foi o município de Mogi das Cruzes, São Paulo, no período de 2003 a 2007. Foram utilizados dados de bases sucundários da Secretaria de Saúde do município para a descrição quanto a estrutura de vigilância. Os registros de temperatura e pluviosidades foram confrontados por meio de correlação com os focos positivos. Resultados. Observou-se deficiência quanto a estrutura e funcionamento dos serviços de vigilância diante do preconizado pelo PNCD, Ministério da Saúde. Os casos de dengue no município são todos importados, e a maioria são de regiões próximas como o litoral norte e sul. Foi fraca, porém significativa a correlação entre a pluviosidade, temperatura e o foco positivo para o vetor. Observou-se por meio de correlação utilizando o time-lag em mês, que houve correlação significativa no mês em que chove e até três meses após a chuva. Conclusões. Os resultados indicam que o município reúne condições favoráveis à epidemia de dengue e necessita aperfeiçoar o seu sistema de prevenção à doença / Introdution: Dengue is a preoccupying re-emergent illness for public health. The agent, Aedes Aegypti, is the main responsible specie for the transmission of dengue virus. Currently the World Health Organization (OMS) estimate that between 50 until 100 million of people are infected annually in all countries of continents with exception of Europe. Aim. Describe and know the structure of control services of Aedes aegypti and the epidemiologists aspects of dengue in Mogi das Cruzes city, São Paulo. Method. The study area was the Mogi das Cruzes city, Sao Paulo, in the period of 2003 until 2007. It had been used data base of Health Secretary of city to describe as the structure of vigilance. The registers of temperature and rainfalls had been collated by correlation with positive focus. Results. Observed the deficiency for the structure and functionality of vigilance services in the presence of described by PCND, Minister of Health. The all cases of dengue in the city are imported, and the majority is from next regions as north and south coast. It was weak, however the significant correlation between the rainfall, temperature and positive focus for the vector. Observed by correlation mode using the time-lag in month, that had significant correlation in the rain month and until three month after rain. Conclusions. The results indicate that the city congregate favorable conditions to the dengue epidemic and needs to improve their system of illness prevention
37

The effect of Plagiorchis elegans cercariae on the vertical distribution of Aedes aegypti larvae /

Gilchrist, Ian G. January 1994 (has links)
The effect of Plagiorchis elegans cercariae on the vertical distribution of second, third, and fourth instar larvae of Aedes aegypti in the water column was studied in the laboratory. Under daytime conditions and in the absence of the parasite, larvae divided their time between the top and bottom of the water column. At night larvae spent the majority of their time at rest at the top of the column. In the presence of P. elegans cercariae larvae spent more time at rest at the surface under daytime conditions but increased their active time at the bottom under nighttime conditions. The presence of cercariae elicited escape and grooming responses and tended to reduce and fragment feeding activity.
38

Feeding preferences of Chaoborus americanus larvae (Diptera:Chaoboridae) and their potential effect on mosquito populations

Autran, Lyris. January 2000 (has links)
Chaoborus americanus larvae were used in laboratory experiments to assess their efficiency at decreasing mosquito larval populations. Third and fourth instar Chaoborus americanus larvae were independently fed assemblages of single prey species to test hunger and several prey species to test preference. Prey species included Daphnia and the four Aedes aegypti larval instars. The results show that Chaoborus americanus larvae will choose early instar mosquito larvae over Daphnia, however, this preference decreases as the mosquito larvae become older. Third instar Chaoborus americanus larvae will choose first instar mosquito larvae over Daphnia 76% of the time, whereas they will select third instar mosquito larvae only 30% of the time. Fourth instar Chaoborus americanus larvae will choose first instar mosquito larvae 94% of the time, and select fourth instar mosquito larvae only 3% of the time. Crowding also has an effect on feeding times; individual Chaoborus larvae take more time to ingest their prey items than do individuals within a group. Chaoborus americanus larvae are good biological control agents within a laboratory setting.
39

The effects of water depth on the development and behavior of fourth instar Aedes aegypti larvae

Audet, Alexandra M. (Alexandra Margaret) January 1996 (has links)
As water depth increased, fourth instar larvae of the mosquito Aedes aegypti required progressively more time to reach the pupal stage, more individuals died or were disabled and the resulting adults were significantly smaller. Water depth affected females more severely than males and the developmental time of larvae was affected more than adult mass. Time spent by fourth instar female larvae in the feeding zone during the first five hours predicted the time to subsequent pupation. Thereafter, mean feeding time was a determining factor of subsequent adult mass. With increasing water depth, both the prepupal resting period and mean time spent in the feeding zone per feeding bout increased, whereas behavior frequency (determined by an activity index) decreased.
40

Poecilia reticulata predation on Aedes aegypti larvae : effects of predator body size and vegetation density

Rodgers, Brandon. January 2007 (has links)
In this study, predation efficiency of three guppy ( Poecilia reticulata) size classes was evaluated at various vegetation densities in a series of circular aquaria containing plastic plants closely resembling Ceratophyllum demersum. The effect of vegetation density was most apparent among large fish where predation efficiency greatly diminished from 12.35 mosquito larvae (Aedes aegypti) to 4.68 as vegetation densities rose from 3 to 19 plants/700 cm2. Over that same range of increasing vegetation densities, predation among small fish remained unchanged, whereas among fish of intermediate size predation declined significantly but less precipitously than for large individuals. When presented with a choice between second and fourth mosquito larvae, small fish preferred to prey on second instars, whereas large fish preferred fourth instar larvae. Fish of intermediate size did not show a statistically significant preference. The functional response of fish to increasing prey densities, as measured over a 12-h period, was of Type III.

Page generated in 0.0466 seconds