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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.
51

Composição da fauna de Hymenoptera associada a área agrícola de manejo tradicional : abelhas nativas e parasitóides /

Souza, Luceli de. January 2006 (has links)
Orientador: Maria José de Oliveira Campos / Banca: Ana Eugênia de Carvalho Campos Farinha / Banca: Isabel Alves dos Santos / Banca: Maria Santina de Castro Morini / Banca: Evandro Camillo / Resumo: Hymenoptera é uma das maiores ordens de insetos e compreende as vespas, abelhas e formigas. Dentro de Aculeata as abelhas são importantes indicadores ecológicos, pois têm papel vital na manutenção natural através da polinização, e na Série Parasitica as vespas se desenvolvem como parasitóides regulando a população de outros artrópodos. A intensificação da agricultura e a conseqüente simplificação da estrutura das paisagens agrícolas têm exercido impacto sobre a riqueza da vegetação e da fauna e este tema tem despertado o interesse em todo o mundo. Diante da preocupação do impacto da agricultura sobre as abelhas nativas e parasitóides, este trabalho teve por objetivo fazer um diagnóstico da composição destes grupos em uma área agrícola no município de Rio Claro, SP. A propriedade estudada caracteriza-se pela produção de grãos, através do sistema de plantio direto e uso de produtos químicos para controle de ervas e insetos. Foram realizadas duas coletas mensais de maio de 2003 a junho de 2004, exceto outubro/03 e janeiro/04, utilizando 16 armadilhas tipo Moericke colocadas diretamente sobre o solo e expostas por 36 horas. Foram coletados 5308 himenópteros parasitóides pertencentes a 8 superfamílias e 22 famílias. As famílias Mymaridae, Encyrtidae, Scelionidae e Platygastridae foram as mais comuns com freqüência relativa de 30.88%, 19.05%, 14.96% e 6.69%, respectivamente. As demais 18 famílias foram coletadas com freqüência menor do que 5%. Foram coletadas 456 abelhas distribuídas em 20 gêneros, pertencentes a três famílias. Na composição da apifauna, Halictidae foi mais freqüente com 54.4% seguida de Apidae (40.8%) e Andrenidae (4.8%). Os gêneros Dialictus (38%) e Diadasia (30%) foram os mais freqüentes. Foi registrada a presença de Callonychium pela primeira vez no Estado de São Paulo / Abstrac: Hymenoptera is one of the largest orders of insects, comprising wasps, bees, and ants. Among the Aculeata, bees are important ecological indicators, as they have a vital role in the natural maintenance through pollination. Among parasitic hymenopterans, wasps develop as parasitoids, regulating the population of other arthropods. The intensification of agriculture and consequently the simplification of the structure of the landscape have had an impact on the richness of the vegetation and fauna, which has attracted the attention of researchers around the world. Concerned with the impact of agriculture on native bees and parasitoids, this study aimed to assess the composition of these groups in an agricultural area in the city of Rio Claro, São Paulo State. The studied area is characterized by the production of grains through direct drilling and chemical products to control weeds and insects. Monthly samples were collected from May 2003 to June 2004, except October/03 and January/04, using 16 Moericke traps placed directly on the soil for 36 hours. A total of 5308 parasitoid hymenopterans of 8 superfamilies and 22 families were collected. Mymaridae, Encyrtidae, Scelionidae and Platygastridae were the most common families with relative frequencies of 30.88%, 19.05%, 14.96%, and 6.69%, respectively. Additionally, 18 families occurred with frequencies lower than 5%. A total of 456 bees of 20 genera belonging to three families were collected. Among bees, Halictidae was the most common family representing 54.4% followed by Apidae (40.8%), and Andrenidae (4.8%). Dialictus (38%) and Diadasia (30%) were the most common genera. Bees of the genus Callonychium were observed for the first time in São Paulo State. The type of management used in the area, direct drilling and soil irrigation, favored the growth of ruderal plants probably used as a source of food / Doutor
52

Diversidade, padrão de distribuição e sazonalidade de besouros associados ao solo em cultivo de soja e plantas herbáceas / Diversity, distribuition pattern and sazonality of ground beetles in soybean crop and herbaceous plants

Correia, Ezequias Teófilo [UNESP] 05 July 2017 (has links)
Submitted by EZEQUIAS CORREIA (ezequiaslca@gmail.com) on 2017-08-08T17:31:54Z No. of bitstreams: 1 Tese _Ezequias_Teófilo_Correia.pdf: 3210175 bytes, checksum: 872ea328869cb654d0fccdfa2518b7a9 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-08-09T12:44:59Z (GMT) No. of bitstreams: 1 correia_et_dr_jabo.pdf: 3210175 bytes, checksum: 872ea328869cb654d0fccdfa2518b7a9 (MD5) / Made available in DSpace on 2017-08-09T12:44:59Z (GMT). No. of bitstreams: 1 correia_et_dr_jabo.pdf: 3210175 bytes, checksum: 872ea328869cb654d0fccdfa2518b7a9 (MD5) Previous issue date: 2017-07-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A redução da biodiversidade nos agroecossistemas afeta populações de insetos predadores devido à limitação de recursos para o seu desenvolvimento. O controle biológico conservativo diversifica o agroecossistema e aumenta à presença de inimigos naturais, incrementando o controle de pragas. As plantas herbáceas além de aumentar a biodiversidade do hábitat, exercem influência na composição das comunidades de insetos no campo incrementando o controle biológico conservativo. O objetivo deste estudo foi avaliar a diversidade, distribuição e sazonalidade de besouros associados ao solo em plantio de soja (Glycine max (L.) Merrill) com faixas de plantas herbáceas nas bordas. O estudo ocorreu entre novembro de 2014 e setembro de 2016 em Jaboticabal-SP. As amostragens foram realizadas com armadilhas tipo alçapão, em dois hectares de área cultivada. Foram analisados os índices de diversidade, abundância, distribuição espacial e sazonalidade de besouros associados ao solo. Resultados evidenciaram maior ocorrência de besouros carabídeos nas faixas de plantas herbáceas. Scarabaeidae e Staphylinidae, por sua vez, não obtiveram crescimento populacional nas áreas de maior diversidade vegetal. A distribuição de espécies de Carabidae e Scarabaeidae foi apresentada de forma agregada sendo que a ocorrência dos insetos dessa família foi influenciada principalmente pela temperatura e umidade relativa. / The reduction of plant diversity in agroecosystems can affect predator insect populations due to the restriction of shelter and food resources. Studies about the role of herbaceous plants have shown the increase of biodiversity and the influence of composition and distribution on predator insects communities in the field. These dates may assist in the elaboration of the conservative biological control management programs. The aim of this study was to evaluate the diversity and abundance of ground beetles in the agroecosystem with soybean crop (Glycine max (L.) Merrill) and evaluate the dispersion of these insects in the habitat. The study was performed between 2014 November and 2016 September in Jaboticabal- SP. The essay was made in the field with 2 ha of soybean crop and herbaceous plant in two edges and the sample was performed with pitfall traps. The dates were analyzed and the diversity, abundance, seasonality indexes and spatial distribution of insects were calculated. The results pointed out that herbaceous plants affect positively the carabid beetle occurrence, but not affect Scarabaeidae and Staphylinidae. The distribution of insects was aggregate in the agroecosystem and the meteorological factors affect the occurrence of Carabidae and Staphylinidae beetles.
53

Evaluation of the large-scale trapping of blowflies (Lucilia spp.) for an integrated pest management program : the lucitrap

Scholtz, Anna J January 2003 (has links)
The results presented in this dissertation have been partially presented at scientific meetings. Chapter 2 is an exact copy of the technical contents of a paper submitted to a scientific journal. The format of this paper however has been changed to comply with the format used in this dissertation. The results of this paper were partially presented at the 36th National Congress of the South African Society of Animal Science, 5 – 8 April 1998 held in Stellenbosch. In this chapter errors occurred in the execution of the trial, but these were corrected in the follow-up trial after consulting with the manufacturers. It is discussed in the paper. Results of chapter 3 were partially presented at the 5th International Sheep Veterinary Congress 21 – 25 January 2001 held in Stellenbosch and at an International Congress (The FLICS (Flystrike & Lice IPM Control Strategies) Conference, 25 – 27 June 2001, Launceston) in Tasmania by Mr. S.W.P. Cloete in 2001. The updated results are given in this chapter. The results of chapter 4 were presented at a combined congress between the Grasslands and the Animal Production Societies of South Africa (The GSSA/SASAS Joint Congress 2002. 13 – 16 May) in Christiana in 2002. The results in this chapter represent the same experimental period as was reported upon at that congress, but additional statistical analyses were executed on the same data set. Copies of the abstracts of the contributions to these meetings are attached in chapter 6. The major objective of this study initially was to evaluate the Lucitrap® system under South African conditions. During the experimental period I had an opportunity to visit Australia and meet many role players. It came under my attention that the control of the blowfly is a rather complex problem with many facets. A current issue worldwide on the use of chemicals as a control method against insects and its hazardous influence on the environment is forcing producers to minimize chemical residues in textiles and other agricultural products. An Integrated Pest Management (IPM) approach seems to be the only option. This study has been executed to try and understand some aspects of the blowfly problem for future application in such a blowfly control program.
54

Etude des neutrophiles, des « neutrophil extracellular traps » et de la protéine C1q du complément dans les réponses inflammatoires : conséquences physiopathologiques dans la polyarthrite rhumatoïde et un modèle expérimental / Study of neutrophils, neutrophil cellular traps, and the complement protein C1q in inflammatory responses : physiopathological consequences in rheumatoid arthritis and an experimental model

Ribon, Matthieu 19 June 2015 (has links)
La polyarthrite rhumatoïde (PR) est une maladie auto-immune inflammatoire. La PR touche les articulations jusqu'à les détruire. Elle est caractérisée par la présence d’anticorps anti protéines citrullinées (ACPA) mais l’auto-antigène n’est toujours pas connu. Dans cette maladie, l’implication de l’immunité adaptative ne fait donc aucun doute mais le rôle de l’immunité innée reste encore flou. Le système du complément joue un rôle important dans l’immunité innée tout comme les récepteurs de type Toll (TLR) qui sont des récepteurs de celle-ci. C1q, par la reconnaissance des ses ligands, active une des voies du complément, la voie classique. Chez les patients atteints de PR, le complément est activé et un dépôt de C1q est retrouvé dans l’articulation. Le TLR9 reconnaît des ADN dérivés de bactéries ou de virus mais une expression à la surface des cellules pourrait conduire à la reconnaissance d’autres motifs comme les signaux de danger (DAMP). D’ailleurs, nous avons montré récemment qu’il existait un TLR9 exprimé à la surface des polynucléaires neutrophiles (PNN). Enfin, il a été mis en évidence récemment un nouveau mécanisme bactéricide effectué par les PNN : la formation de NET (neutrophil extracellular traps). Mais en dehors de leur rôle bactéricide, les NET ont été montrés comme pathogènes dans certaines maladies comme le lupus. Dans ce travail de thèse, je me suis intéressé à l’implication de ces acteurs, NET, C1q et TLR9 dans la PR. Nous avons montré que C1q est indispensable au développement de l’arthrite dans un modèle animal. De plus, l’expression des récepteurs au C1q par les PNN et les monocytes est corrélée à l’activité de la maladie et à l’inflammation. Nous avons montré que les NET représentent une cible pour les ACPA (ce qui en fait des auto-antigènes potentiels dans la PR) et que ces NET sont immunogènes. L’immunogénicité des NET est modulée par C1q. Enfin, il semblerait que le TLR9 ait moins d’importance dans l’arthrite. Par ce travail, nous avons montré l’importance du rôle joué par l’immunité innée dans la PR et ses modèles. / Rheumatoid artthritis (RA) is the most frequent rheumatic disease. This auto-immune disease causes pain and joint destruction. RA has been characterized by adaptative immunity involvement and anti-citrullinated protein antibodies (ACPA) production. Involvement of innate immunity is less investigated. Complement system, part of innate immunity, is activated in RA. C1q activates classical complement pathway by binding its ligands. C1q is found in joint of RA patients. On the other hand Toll-like-receptor (TLR), innate receptors could play a role in RA upon recognition of pathogen-derived DNA (TLR9). Cell surface expression of TLR9 has been reported as potentially pathological, and we describe that polymorphonuclear neutrophils (PMN) express a cell surface TLR9 wich could recognize damage associated molecular pattern (DAMP). Finally, neutrophil extracellular traps (NET) wich are expelled chromatin fiber and represent a physiological response to bacteria, have been reported as pathological in certain circumstances. We investigated the role of those three innate actors in RA. We have shown that C1q is mandatory to develop experimental arthritis and expression of their receptors on RA patient PMN and monocytes is correlated with disease activity and inflammation. We have also shown that NET are immunogenic and this immunogenicity is partly modulated and mediated by C1q. NET might trigger ACPA production in RA. Finally, it seems that involvement of TLR9 is less important in RA. With those experiments we have shown that the involvement of innate immunity in RA is more important than that has been reported so far.
55

Neutrophil extracellular traps in thrombosis and inflammation

Martinod, Kim Lindsay 01 January 2016 (has links)
Neutrophil extracellular traps (NETs), chromatin released by activated neutrophils, were first described for their antimicrobial properties. NETs have a backbone of DNA and histones lined with microbicidal proteins such as neutrophil elastase. NET release has pathological consequences, particularly within blood vessels where NETs can trap red blood cells and platelets, thus contributing to thrombosis (Chapter 1-Overview). NET formation (NETosis) is an active and coordinated biological process involving many enzymatic components. One enzyme in particular, peptidylarginine deiminase 4 (PAD4), citrullinates histones and is required for chromatin decondensation during NETosis. Neutrophils from PAD4-deficient mice are unable to form NETs. We obtained these mice from our collaborator Dr. Yanming Wang, and thus were able to compare PAD4-/- mice to wild-type (WT) mice in mouse models where NETs are formed. These studies have allowed for investigation of the biological relevance of PAD4 and NETs in vivo in thrombotic and/or inflammatory disease. This dissertation focuses on mouse models of deep vein thrombosis and of sepsis. In venous stenosis, thrombosis is initiated by restricting blood flow in the inferior vena cava (IVC). Here, PAD4-/- mice were greatly protected from thrombus formation (Chapter 2). Leukocyte rolling and platelet plug formation in response to vessel injury were unaffected, indicating that endothelial and platelet activation occurred normally in these mice. The mice did not exhibit any defects in hemostasis, and could be induced to produce deep vein thrombi by infusion of WT neutrophils that formed NETs as a part of the thrombus scaffold. Because there is potential to develop anti-NET therapies in thrombosis, I investigated if NET-deficiency would render mice immunocompromised (Chapter 3). PAD4-/- mice had similar mortality in the cecal ligation puncture model, and they were protected from shock in an LPS sepsis model where NETs are released in the absence of live bacteria. Therapies aimed at NET prevention or destruction would likely be beneficial without compromising host immunity. Thus, in summary, studying PAD4-deficient mice has revealed the impact of NETs in thrombotic/inflammatory disease and identified PAD4 as an attractive therapeutic target.
56

Life Cycle of Deccan Trap Magma Chambers: A Crystal Scale Elemental and Strontium Isotopic Investigation

Borges, Melroy R 07 November 2007 (has links)
The Deccan Trap basalts are the remnants of a massive series of lava flows that erupted at the K/T boundary and covered 1-2 million km2 of west-central India. This eruptive event is of global interest because of its possible link to the major mass extinction event, and there is much debate about the duration of this massive volcanic event. In contrast to isotopic or paleomagnetic dating methods, I explore an alternative approach to determine the lifecycle of the magma chambers that supplied the lavas, and extend the concept to obtain a tighter constraint on Deccan’s duration. My method relies on extracting time information from elemental and isotopic diffusion across zone boundary in an individual crystal. I determined elemental and Sr-isotopic variations across abnormally large (2-5 cm) plagioclase crystals from the Thalghat and Kashele “Giant Plagioclase Basalts” from the lowermost Jawhar and Igatpuri Formations respectively in the thickest Western Ghats section near Mumbai. I also obtained bulk rock major, trace and rare earth element chemistry of each lava flow from the two formations. Thalghat flows contain only 12% zoned crystals, with 87Sr/86Sr ratios of 0.7096 in the core and 0.7106 in the rim, separated by a sharp boundary. In contrast, all Kashele crystals have a wider range of 87Sr/86Sr values, with multiple zones. Geochemical modeling of the data suggests that the two types of crystals grew in distinct magmatic environments. Modeling intracrystalline diffusive equilibration between the core and rim of Thalghat crystals led me to obtain a crystal growth rate of 2.03x10-10 cm/s and a residence time of 780 years for the crystals in the magma chamber(s). Employing some assumptions based on field and geochronologic evidence, I extrapolated this residence time to the entire Western Ghats and obtained an estimate of 25,000 – 35,000 years for the duration of Western Ghats volcanism. This gave an eruptive rate of 30 – 40 km3/yr, which is much higher than any presently erupting volcano. This result will remain speculative until a similarly detailed analytical-modeling study is performed for the rest of the Western Ghats formations.
57

A Preliminary Investigation Of The Role Of Magnetic Fields In Axially Symmetric rf Ion Traps

Sridhar, P 04 1900 (has links) (PDF)
Axially symmetric rf ion traps consists of a mass analyser having three electrodes, one of which is a central ring electrode and the other two are endcap electrodes. In the ideal Paul trap mass spectrometer, the electrodes have hyperboloidal shape (March and Hughes, 1989) and in mass analyser with simplified geometry, such as the cylindrical ion trap (Wu et al.,2005) the central electrode is a cylinder and the two endcap electrode and flat plates. rf-only or rf/dc potential is applied across the ring electrode and the grounded endcap electrodes for conducting the basic experiments of the mass spectrometer. In recent times, the miniaturisation of ion trap is one of the research interests in the field of mass spectrometry. The miniaturisation has the advantages of compactness, low power consumption and portability. However, this is achieved at the cost of the overall performance of the mass spectrometer with its deleterious effect on resolution. Research groups study the field distribution in the trap for better understanding of ion dynamics in the direction of achieving improved performance with the miniaturised traps. One aspect which has not received any attention in research associated with quadrupole ion traps is the possible role of the magnetic field in improving performance of these traps. Since in the quadrupole ion trap mass analyser ion is confined by an oscillating (rf) field, magnetic fields have been considered superfluous. The motivation of the thesis is to understand the dynamics of ions in axially symmetric rf ion traps, in the presence of the magnetic field. The axially symmetric rf ion trap geometries considered in this thesis are the Paul trap and the cylindrical ion trap (CIT). The changes incurred to the ion motion and Mathieu stability diagram in the presence of magnetic field is observed in this work. Also, the relation between the magnetic field and the Mathieu parameter is shown. The thesis contains 4 chapters: Chapter 1 provides the basic back ground of mass spectrometry and the operating principles. The equations of ion motion in the Paul trap is derived and also the solution to Mathieu equation is provided. The solution to the Mathieu equation are the Mathieu parameters and , when plotted with on the x-axis and on the y-axis, results in the Mathieu stability plot, the explanation of which is also given in the chapter. A brief description of the secular frequency associated with the ion dynamics is given in this chapter. The popular experiments conducted (i.e. the mass selective boundary ejection and resonance ejection) with a mass spectrometer is described here. Finally at the end of the chapter is the scope of the thesis. Chapter 2 facilitates with the preliminary study required fort he accomplishment of the task. The Paul trap and the CIT are the rf ion traps considered in this work. The geometries of these two traps are described in this chapter. The computational methods used for the analysis of various aspects of mass spectrometer is introduced. The computational methods used involve the methods used for calculating the charge distribution on the electrodes, potentials, multipole co-efficients and trajectory calculations. The boundary element method(BEM), calculation for Potentials and the Runge-Kutta method used for the trajectory calculations are introduced in this chapter. The expressions for calculating the multipole co-efficients are also specified. Chapter 3 presents the results obtained. The equations of ion motion in a quadrupole ion trap in the presence of magnetic field is derived here. Verification of numerical results with and without the magnetic field are presented at the end of this chapter. The chapter also presents various graphs showing the impact of magnetic field on the ion dynamics in the Paul trap and the CIT. The impact of the presence of magnetic field on the micro motion in -, -and -directions of the rf ion traps are shown in this chapter. Also the figures showing the variation in the Mathieu stability plots, with varying magnetic field intensity are presented in the chapter. At the end of this chapter the relation between the magnetic field and the Mathieu parameter is derived and plotted. Chapter 4 explains the various observations made from the results obtained. This chapter also highlights the future scope of the work for making this a more applicable one. References in the text have been given by quoting the author’s name and year of publication. Full references have been provide, in an alphabetic order, at the end of the thesis.
58

Proces manažerského rozhodování v kontextu iracionality rozhodovatele / Irrationality in the decision making process

Renner, Petr January 2011 (has links)
The diploma thesis deals with the crucial aspect of manager's and leader's role in both public and private organizations -- decision making. It explains the different phases of the decision making process, and then challenges the classical concept based on the theory of rational choice with the results of many experiments outlining a slightly different picture of reality. It seems thought, that human decisions are not fully rational indeed. Despite the availability of advanced methods and tools, many of us instinctively rely on a variety of mental shortcuts and simplifications. Even worse, because they are rooted very deep into our minds and are rather non conscious, we tend to make the same mistakes again and again. To explore and to be fully aware of the danger of this psychological traps threatening the different phases of the decision making process, is the first important step on the way to weaken their influence. Tips and hints illustrated with many experiments and real-life examples from business in this thesis should help us to improve the quality of our decisions and achieve better results.
59

Synthetic Studies of Azulenyl and Pseudoazulenyl Nitrones

Kolhe, Amolkumar 11 March 2009 (has links)
Free radicals have been implicated in various pathological conditions such as, stroke, aging and ischemic heart disease (IHD), as well as neurodegenerative diseases like Alzheimer’s, Parkinson’s, and Huntington’s disease. The role of antioxidants in protection from the harmful effects of free radicals has long been recognized. Trapping extremely reactive free radicals and eliminating them from circulation has been shown to be effective in animal models. Nitrone-based free radical traps have been extensively explored in biological systems. Examples include nitrones such as PBN, NXY-059, MDL-101,002, DMPO and EMPO. However, these nitrones have extremely high oxidation potentials as compared to natural antioxidants such as Vitamin E (á-tocopherol), and glutathione. Becker et al. (1995) synthesized novel azulenyl nitrones, which were shown to have oxidation potentials much lower than that of any of the previously reported nitrone based spin traps. Another azulenyl nitrone derivative, stilbazulenyl nitrone (STAZN), was shown to have an even lower oxidation potential within the range of natural antioxidants. STAZN, a second generation free radical trap, was found to be markedly superior than the two most studied nitrones, PBN and NXY-059, in animal models of cerebral ischemia and in an in vitro assay of lipid peroxidation. In this study, a third generation azulenyl nitrone was synthesized with an electron donating group on the previously synthesized STAZN derivative with the aim to lower the oxidation potential even more. Pseudoazulenes, because of the presence of an annular heteroatom, have been reported to possess even lower oxidation potential than that of the azulenyl counterpart. Therefore, pseudoazulenyl nitrones were synthesized for the first time by extracting and elaborating valtrate from the roots of Centranthus ruber (Red valerian or Jupiter’s beard). Several pseudoazulenyl nitrones were synthesized by using a facile experimental protocol. The physical and biological properties of these pseudoazulenyl nitrones can be easily modified by simply changing the substituent on the heteroatom. Cyclic voltammetry experiments have shown that these pseudoazulenyl nitrones do indeed have low oxidation potentials. The oxidation potential of these nitrones was lowered even more by preparing derivatives bearing an electron donating group at the 3-position of the five membered ring of the pseudoazulenyl nitrone.
60

Improvements in the design and usage of red sticky spheres to control the apple maggot fly (R. pomonella).

Reynolds, Alan H. 01 January 1997 (has links) (PDF)
No description available.

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