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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.
11

Zur Kenntnis der physiologischen Anatomie der Gattung Kleinia

Kahns, Hans, January 1909 (has links)
Inaug.-Diss.--Kiel. / Vita. Bibliography: p. [82]-83.
12

Studies in alkaloid chemistry

Suffness, Matthew. January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references.
13

Lesões hepáticas de bovinos intoxicados experimentalmente por Senecio brasiliensis (Compositae) : estudo semi-quantitativo e quantitativo da matriz extracelular e de células sinusoidais /

Torres, Márcia Bersane Araújo de Medeiros January 2003 (has links)
Orientador: Kunie Iabuki Rabello Coelho / Resumo: A matriz extracelular hepática (MEC) é atualmente alvo de diversos estudos em modelos de intoxicação experimental e lesões hepáticas crônicas, devido ao seu papel relevante nesses processos. Na espécie bovina, não existem estudos sobre os componentes da MEC hepática normal e nas lesões crônicas os enfoques têm sido os hepatócitos, com apresentações descritivas das alterações da matriz. Por esse motivo propusemos um modelo iniciando com estudo de fígados normais (controle) obtidos dos animais antes do início da intoxicaçãp experimental por Senecio brasiliensis. Esta planta contém alcalóides pirrolizidínicos (APs), que são substâncias causadoras de lesão hepática crônica progressiva. Este trabalho tem como principais objetivos fazer uma avaliação semi-quantitativa e quantitativa de componentes da MEC de fígado normal e de suas alterações durante a progressão da lesão hepática por intoxicação crônica por APs na espécie bovina. Foram usados 5 animais, intoxicados com folhas dessecadas de S. brasiliensis na dose de 0,38g/kg de peso corporal diariamente durante 24 dias. O experimento teve duração de 60 dias e foi dividido em 5 momentos (M1= controle; M2=15 dias; M3= 30 dias; M4=45 dias e M5=60 dias), nos quais os animais foram submetidos a biópsias hepáticas e colheita de sangue para exames bioquímicos. As biópsias hepáticas foram processadas para MO, Imuno-histoquímica e MET. Como foram observados sinais clínicos digestivos no início da 3a semana suspendeu-se a administração da planta aos 24 dias. Mesmo assim as lesões foram progressivas, com morte de um animal aos 45 dias. A partir de M2 havia alterações degenerativas, necrose, apoptose e megalocitose de hepatócitos associadas à fibrose portal, centrolobular e pericelular. Foi feita morfometria por análise de imagem para colágeno total com... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Extracellular matrix (ECM) has been studied on chronic hepatic lesions of experimental intoxication models due to its relevant role in this pathologic process. Nevertheless there are no specific studies on ECM in normal or chronically damaged bovine liver. Hepatocellular damage has been more important center of attention in chronic bovine liver damage and ECM has been simply described. Because of this fact we decided to present a bovine model starting with detailed study of normal (control) liver biopsy taken from animals before experimental intoxication by Senecio brasiliensis. This plant contains pyrrolizidine alkaloids (PA) that causes acute or chronic progressive liver damage. The main objetive of this project is to do quantitative and / or semi-quantitative measurement of specific components of normal liver ECM and its change during progressive liver damage when bovines are submitted to chronic PA intoxication. Five animals received 0,38g of dry leaf of S. brasiliensis per Kg of body weight orally per day during 24 days. All but one animal were evaluated up to 60 th day. Liver biopsy and blood samples were collected on 5 moments (M1= controle; M = 15th day; M3 = 30th day; M4=45th day and M5=60th day). Biopsy samples were processed for light microscopy, immuno-histochemistry and transmission electron microscopy (TEM) at the begining of the 3rd week some clinical signs indicated digestive complications and we stoped giving toxic plant on 24th day of experiment. Liver lesions were progressive even after that day and one animal died on 45th day. From M2 on ligth microscopy showed hepatocellular degenerative changes, necrosis, apoptosis and megalocitosis plus portal, centrilobular and pericellular fibrosis. Morphometric study by analysis of image for total collagen was done using Picrossirius staining and for elastic fiber system was done using... (Complete abstract, click electronic address below) / Doutor
14

Multiple origins of Senecio cambrensis Rosser and related evolutionary studies of British Senecio

Ashton, Paul Allan January 1991 (has links)
The most important finding to emerge from the studies reported in this thesis was the discovery that the newly arisen allopolyploid species, S. cambrensis Rosser, has originated on more than one occasion in Britain. A survey of isozyme variation for acid phosphatase (ACP) and a-esterase (a-EST) in S. cambrensis (2n = 60) and its putative parents, the Oxford Ragwort, Senecio squalidus L. (2n = 20) and the Common Groundsel, S. vulgaris L. (2n = 40), produced clear evidence that the Scottish and Welsh populations of S. cambrensis have separate origins. In addition, isozyme banding patterns for glutamate oxaloacetate transaminase (GOT) indicated that populations of S. cambrensis from Wrexham and Mochdre in N. Wales also represent independent origins of the species in Britain. Extending the isozyme survey to include other populations of the two parental species led to the confirmation that the radiate allele in S. vulgaris has an introgressive origin from S. squalidus. Evidence for this came from an analysis of variation at the Got-1 locus. It was established that the Got-1a allele which is present in British S. squalidus populations at high frequency also occurs in the radiate morph of S. vulgaris, but is virtually absent from the non-radiate morph. The greater allelic variation found at the Got-1 locus in the radiate morph, compared to the non-radiate morph, was considered to be a direct result of this introgression. In contrast, at other loci, the non-radiate morph exhibited greater allelic variation than the radiate morph, despite having a higher level of inbreeding. The reduced level of genetic variation in the radiate variant at these loci is presumed to be due to the recent origin of the radiate morph in Britain. Of additional interest was the finding that S. squalidus contains a low level of genetic variation compared with most other outcrossing species that have been surveyed to date, probably due to a genetic bottleneck experienced by the species during its colonisation of Britain. Nevertheless, the level of variation within S. squalidus was still higher than that observed in the predominantly selfing S. vulgaris. Finally, evidence from the electrophoretic survey has confirmed the close evolutionary relationship of several other members of Senecio section Annui (S. viscosus, S. sylvaticus, S. vulgaris ssp. denticulatus, S. teneriffae and S. vernalis ) to S. vulgaris var. vulgaris and S. squalidus, but has failed to support the hypothesis that S. vulgaris originated from S. vernalis via autopolyploidy.
15

Lesões hepáticas de bovinos intoxicados experimentalmente por Senecio brasiliensis (Compositae): estudo semi-quantitativo e quantitativo da matriz extracelular e de células sinusoidais

Torres, Márcia Bersane Araújo de Medeiros [UNESP] January 2003 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T20:24:57Z : No. of bitstreams: 1 torres_mbam_dr_botfm.pdf: 1206082 bytes, checksum: a2242cde390376c1aa8e4dc3aeea4899 (MD5) / A matriz extracelular hepática (MEC) é atualmente alvo de diversos estudos em modelos de intoxicação experimental e lesões hepáticas crônicas, devido ao seu papel relevante nesses processos. Na espécie bovina, não existem estudos sobre os componentes da MEC hepática normal e nas lesões crônicas os enfoques têm sido os hepatócitos, com apresentações descritivas das alterações da matriz. Por esse motivo propusemos um modelo iniciando com estudo de fígados normais (controle) obtidos dos animais antes do início da intoxicaçãp experimental por Senecio brasiliensis. Esta planta contém alcalóides pirrolizidínicos (APs), que são substâncias causadoras de lesão hepática crônica progressiva. Este trabalho tem como principais objetivos fazer uma avaliação semi-quantitativa e quantitativa de componentes da MEC de fígado normal e de suas alterações durante a progressão da lesão hepática por intoxicação crônica por APs na espécie bovina. Foram usados 5 animais, intoxicados com folhas dessecadas de S. brasiliensis na dose de 0,38g/kg de peso corporal diariamente durante 24 dias. O experimento teve duração de 60 dias e foi dividido em 5 momentos (M1= controle; M2=15 dias; M3= 30 dias; M4=45 dias e M5=60 dias), nos quais os animais foram submetidos a biópsias hepáticas e colheita de sangue para exames bioquímicos. As biópsias hepáticas foram processadas para MO, Imuno-histoquímica e MET. Como foram observados sinais clínicos digestivos no início da 3a semana suspendeu-se a administração da planta aos 24 dias. Mesmo assim as lesões foram progressivas, com morte de um animal aos 45 dias. A partir de M2 havia alterações degenerativas, necrose, apoptose e megalocitose de hepatócitos associadas à fibrose portal, centrolobular e pericelular. Foi feita morfometria por análise de imagem para colágeno total com... / Extracellular matrix (ECM) has been studied on chronic hepatic lesions of experimental intoxication models due to its relevant role in this pathologic process. Nevertheless there are no specific studies on ECM in normal or chronically damaged bovine liver. Hepatocellular damage has been more important center of attention in chronic bovine liver damage and ECM has been simply described. Because of this fact we decided to present a bovine model starting with detailed study of normal (control) liver biopsy taken from animals before experimental intoxication by Senecio brasiliensis. This plant contains pyrrolizidine alkaloids (PA) that causes acute or chronic progressive liver damage. The main objetive of this project is to do quantitative and / or semi-quantitative measurement of specific components of normal liver ECM and its change during progressive liver damage when bovines are submitted to chronic PA intoxication. Five animals received 0,38g of dry leaf of S. brasiliensis per Kg of body weight orally per day during 24 days. All but one animal were evaluated up to 60 th day. Liver biopsy and blood samples were collected on 5 moments (M1= controle; M = 15th day; M3 = 30th day; M4=45th day and M5=60th day). Biopsy samples were processed for light microscopy, immuno-histochemistry and transmission electron microscopy (TEM) at the begining of the 3rd week some clinical signs indicated digestive complications and we stoped giving toxic plant on 24th day of experiment. Liver lesions were progressive even after that day and one animal died on 45th day. From M2 on ligth microscopy showed hepatocellular degenerative changes, necrosis, apoptosis and megalocitosis plus portal, centrilobular and pericellular fibrosis. Morphometric study by analysis of image for total collagen was done using Picrossirius staining and for elastic fiber system was done using... (Complete abstract, click electronic address below)
16

Variação espacial na densidade, riqueza e composição de especies de insetos associados a capitulos de Senecio brasiliensis (Asteraceae)

Macedo, Antonio Carlos Cruz 10 June 2000 (has links)
Orientador: Thomas Michael Lewinsohn / Dissertação (mestrado) - Universidade Estadual de Campinas. Instituto de Biologia / Made available in DSpace on 2018-07-27T07:24:06Z (GMT). No. of bitstreams: 1 Macedo_AntonioCarlosCruz_M.pdf: 2094188 bytes, checksum: e66ae28032267f9caecfa9a371502ae1 (MD5) Previous issue date: 2000 / Resumo: Esta tese foi dividida em dois capítulos. No capítulo I, foram analisados os fatores responsáveis pela variação da densidade de insetos por planta nas populações de Senecio brasiliensis (Asteraceae), bem como a relação entre densidade local dos insetos e sua distribuição geográfica (fteqüência de ocorrência nas populações de plantas). No capítulo n, foram analisados os fatores responsáveis pela variação da riqueza de insetos por planta. Estudou-se também o efeito da distância entre populações de plantas e do tamanho das populações de hospedeiras sobre a similaridade na composição de insetos. O trabalho foi realizado em duas regiões no Sudeste do Brasil. Na região denominada Norte (Estado de Minas Gerais), foram amostradas 4 localidades e na região denominada Sul (Estados de São Paulo e Paraná), 5 localidades. Em cada localidade, foi amostrado um par de manchas (populações discretas) de Senecio brasiliensis, sendo uma grande e uma pequena. Em cada mancha, foram amostradas 30 plantas e, de cada uma destas, 30 capítulos, que foram dissecados. Foram encontradas dez espécies de insetos, sendo oito endófagos, um galhador e um predador. As espécies pertencem às famílias Cecidomyiidae, Agromyzidae (Diptera), Pyralidae, Tortricidae e Pterophoridae (Lepidoptera). A variação da densidade e riqueza de insetos por planta foi estudada em relação às variáveis região, localidade, complexi~e da vegetação no entorno da mancha, tamanho da mancha, densidade de plantas na mancha e tamanho das plantas. Os fatores mais importantes na variação da densidade de insetos foram a complexidade da vegetação no entorno das manchas e a variável localidade, que reflete particularidades históricas e ecológicas de cada área. As variáveis que medem a concentração de recursos das plantas (tamanho da mancha, densidade de plantas e tamanho das plantas) não afetaram as densidades da maioria das espécies, poss~velmente devido ao hábito generalista destas e à saturação da capacidade reprodutiva. Somente Melanagromyza erechtitidis (Agromyzidae), o inseto mais especialista encontrado, softeu efeito significativo da densidade e do tamanho das pl~tas. Foi observada cada espécie de inseto. A riqueaza de insetos por planta também softeu efeito significativo das variáveis vegetação no entorno e localidade. Existe uma maior riqueza de espécies em plantas com maior complexidade de vegetação ao seu redor. Este resultado pode estar relacionado ao hábito generalista das espécies. A variável localidade reflete variações em particularidades e no histórico de colonização de cada área. As variáveis que medem a concentração de recursos das plantas também não afetaram a riqueza de insetos por planta. Foi encontrado um efeito significativo da distância entre manchas sobre a similaridade faunística destas, mostrando que manchas mais distantes apresentavam menor similaridade. Manchas de tamanhos semelhantes apresentaram maior similaridade faunística do que manchas de diferentestamanhos. Os resultados mostram que, tanto variáveis locais das manchas, quanto fatores de grande escala, relacionados à distribuição espacial da planta hospedeira e dos insetos, são importantes na determinação da densidade local, da riqueza e da composição de espécies de insetos de capítulos nas manchas de Senecio brasiliensis / Abstract: This thesis was divided in two chapters. In chapter I, I investigated the factors responsible for the variation of insects density per plant in Senecio brasiliensis populations. I also related the insects local density and its geographic distribution. In chapter 11,I ana1yzedthe factors responsible for the variation of insect richness per plantoI also investigatedthe effect of the distance among patches and the patches size on the similarity of the insects composition. The field work was carried out in two regions in Southem Brazil. I sampled four sites in the region named North (Minas Gerais state), and five in the region named South (São Paulo and Paraná states). In each locality I sampled a pair of patches (discrete populations) of Senecio brasiliensis, one large and one sma1l.In each patch I sampled 30 plants and ftom each one 30 flowerheads were dissected. Ten species of insects were obtained: eight endophagous, one galler and one predator species. The species belong to the families Cecidomyiidae, Agromyzidae (Diptera), Pyralidae, Tortricidae and Pterophoridae (Lepidoptera). I analyzed the variation of insect density and richness per plant in relation to region, locality, vegetation complexity surrounding the patch, patch size, plant density in the patches, and plant size. The two main factors explaining the insects density variability were the complexity of the vegetation surrounding the p~tches and loca1ity,which reflects characteristics of each area. The variables that estimate the plant resource concentration (patch size, plant density and plant size) did not interfere in most of the insect species densities, probably because of their generalist habit and the saturation on the reproductive capacity. OnlyMelanagromyza erechtitidis (Agromyzidae),the most specialist insect species, was significantly influencedby plants density and size. I detected a significant positive relationship between the average density of insects per plant, per patch and its geographic distribution (number of localities in whiçh they occurred) for each insect species. Both the complexity of vegetation surrounding the patches and locality also presented a significant effect on the insects richness per planto There !S a higher insect richness in plants surrounded by more complex vegetation. This result may be related to the generalist habit of these species. The loca1ityvariable reflects, for each arca, its particularities variations and colonization history. The variables reflecting resource concentration in the host plant (patch size,plant density and plant size) did not interfere with the insects richness per planto I found a significant effect of the distance among patches on their faunistic similarity, with more distant patches showing less similarity. Similar sized patches showed a higher faunistic similarity than different sized patches. The results show that both plants local characteristics and large scale factors related to the spatial distribution of the host plant and insects are important in determining the local density, richness and composition of insects inhabiting Senecio brasiliensis flowerheads / Mestrado / Mestre em Ecologia
17

Estudo fitoquimico em especies do genero senecio (Asteraceae)

Paiva, Joseilson Alves de 03 August 2018 (has links)
Orientadores: Lauro E. S. Barata, Jose Roberto Trigo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-03T12:05:20Z (GMT). No. of bitstreams: 1 Paiva_JoseilsonAlvesde_D.pdf: 3444809 bytes, checksum: 1e7fc895bb2657474c5d5b7fa1920773 (MD5) Previous issue date: 2002 / Doutorado
18

A study of the interrelationships of some Natal species of Senecio (Asteraceae/Compositae)

Vincent, Leszek Paul Doroszynski. January 1984 (has links)
This dissertation presents the results of studies of the generic concept of Senecio and the subsequent testing of the hypothes is: that many of the species of Senecio in Natal are congeneric with Senecio L. sensu stricto. The sample of taxa studied consisted of 87 Natal senecios, 5 Cape heterochromous senecios and 10 non-southern African senecios, including the type of the genus, S. vulgaris L. Also included in the study were 5 species from taxonomically closely related genera in the tribe Senecioneae and two senecios of uncertain taxonomic position. The phenotype of these taxa was investigated with respect to a large number of morphological and micromorphological characters (126) and the data obtained were analysed neurally and numerically. Aspects of the pollen micromorphology, of all the taxa studied, were also investigated using the scanning electron microscope. A review of the chemical complement of all the taxa studied. particularly with respect to terpenes and pyrrolizidine alkaloids, was also undertaken. Six characters were selected as being taxonomically significant with respect to elucidating the generic concept of Senecio. A further 31 characters and the aforementioned 6, were selected as .being taxonomically significant with respect to elucidating the interrelationships of the Natal senecios and all the senecios studied. The generic concept of Senecio has been re-circumscribed and the generic status of each of the senecios studied has been tested according to this concept of Senecio sensu Vincent. In the light of my concept of Senecio, the following species are excluded from Senecio sensu Vincent: S. barbertonicus Klatt, S. cissampelinus (DC.) Schultz Bipontinus, S. fulgens (J.D. Hooker) Nicholson, S. helminthioides (Schultz Bipontinus) Hilliard, S. hockii De Wild. & Muschl., S. medley-woodii Hutchinson, S. radicans (L.L) Schultz Bipontinus, S. syringifolius O.Hoffm., S. tamoides DC., S. transvaalensis Bolus and S. viminalis Bremekamp. Senecio brevilorus Hilliard, S. seminiveus Wood & Evans and S. tanacetopsis Hilliard are considered to be peripheral to Senecio s. str. sensu Vincent, and are included in Senecio s. lat. sensu Vincent. The hypothesis regarding the generic status of the Natal senecios has been accepted, subsequent to the circumscription of Senecio s. str. sensu Vincent. Estimates of the phenetic affinity of all the members of Senecio sensu stricto sensu Vincent, included in this study, have been made. The majority of the Natal senecios, while clearly being members of Senecio s. str. sensu Vincent, are distinct from virtually all the Cape and non-southern African senecios studied. Many of the non-yellow (purple) Natal senecios form clearly allied groups which are distinct from the groups (clusters) composed of yellow senecios. The taxonomic position of several taxa is questioned, in the light of the cluster analyses. The evidence from the palynological studies neither contradicts nor supports the proposed infrageneric interrelationships, with respect to the Natal members of Senecios. str. sensu Vincent. The evidence also neither contradicts nor supports the proposed interrelationships between the Natal, the Cape and the non-southern African members of Senecios. str. sensu Vincent. The terpene and pyrrolizidine chemistry of many of many of the senecios studied is characterised by the presence of furanoeremophilanes. Eremophilanes also occur and are particularly associated with a number of non-yellow (purple) senecios. Pyrrolizidine alkaloids are not ubiquitous amongst the senecios studied, while some senecios appear to only synthesise pyrrolizidine alKaloids. The review of the errpene and pyrrolizidine chemistry of the senecios investigated, illustrates how our knowledge at or near the level of analytic characters is far from complete. However, we have definitely progressed from the synthetic level of character use. Nevertheless, the relationships between the members of Senecios. str. sensu Vincent, could not be evaluated in the light of the individual chemical complement of terpenes and pyrrolizidine alkaloids, because of a lack of information. An hypothesis of the chemical evolution within the Senecioneae is tested with in Senecios. str. sensu Vincent . Before any taxonomic changes are made to t he current composition of Senecio L., the concept of Senecio L. s. str. sensu Vincent, needs to be tested against a far wider sample of the genus. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1984.
19

Population dynamics of three early seral herb species in Pacific Northwest forests /

Hanson, D. Eric. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2000. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
20

Ovinocultura como ferramenta de controle de Senecio spp. / Sheep production as a Senecio spp. control tool

Bandarra, Paulo Mota January 2014 (has links)
As intoxicações por Senecio spp. estão entre as principais causas de morte no Sul do Brasil, sendo o controle desse gênero de plantas prioritário para a pecuária local. Uma área de 5,5 hectares severamente infestada por Senecio brasiliensis e Senecio madagascariensis foi roçada e submetida ao pastejo por ovinos e bovinos. Uma população total de 28.629 plantas, entre S. brasiliensis (10.122) e S. madagascariensis (18.507) foi virtualmente eliminada em um período de dois anos. O número de ovinos foi mantido em três unidades por hectare, mas variáveis lotações de bovinos foram associadas com a disponibilidade de forragem. As principais práticas de manejo sanitário aplicadas aos ovinos foram administrações de anti-helmínticos e controle de ectoparasitas. Biópsias hepáticas, colhidas antes e após o período de estudo, não revelaram qualquer alteração histopatológica associável com seneciose. Os níveis de desempenho dos ovinos foram acompanhados através do controle da reprodução, produção de lã e ganho de peso. O desempenho produtivo dos ovinos mantidos sob o pastejo da área infestada por Senecio spp. foi similar ao grupo controle e comparável com o observado em rebanhos manejados em sistemas extensivos tradicionais no Sul do Brasil. / Since poisoning by Senecio spp. is one of the main causes of cattle death in southern Brazil, control of these plants is a priority for the local livestock production. After the pasture has been mowed, grazing by sheep and cattle was efficient for controlling Senecio brasiliensis and Senecio madagascariensis populations in a 5.5-hectare area that had long been severely infested with these species. A total of 28,629 plants among S. brasiliensis (Flower of souls - 10,122) and S. madagascariensis (fireweed - 18,507) were almost completely eliminated in a two year period. The number of sheep was kept at 3.0 stock units/ ha, but a variable number of cattle were temporarily stocked according to pasture availability. The major sanitary practices applied to the sheep were anthelmintic administration and ectoparasites control. Liver biopsies taken from sheep and cattle before and after experimental period didn´t reveal any change associable with seneciosis. The performance levels of the senecio-grazing sheep were similar to the control group and comparable to those observed in flocks managed under traditional extensive grazing systems in southern Brazil.

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