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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.
71

Mining Fungal Effector Candidates In Biotrophic Plant Pathogens / Rusts And Mildews

Umu, Sinan Ugur 01 July 2012 (has links) (PDF)
Biotrophic plant pathogens lead to huge crop losses and they have great economical drawbacks on wheat and barley production. These pathogens rely on formation of haustoria and transfer of effector proteins into the host cells for generating disease. The main role of effector proteins is to disable plant defense mechanisms. Effector proteins contain N-terminal signal peptides and they have little sequence similarity between each other. It is vital to detect as many effector proteins as possible to understand infection and disease formation processes of biotrophic plant pathogens. To this end, sequencing of pathogen genomes are being emerged, the data will be invaluable for identifying the candidate effectors in terms of biological and biochemical roles in infection and more. There are some bioinformatics based methods available that can be utilized to classify and distinguish effectors from other pathogenic genes. It is important to understand how candidate effectors can be searched from Expressed Sequence Tags or transcriptome sequences. Hereby, our attempt is to present a pipeline in establishing a methodology. As a consequence, here we propose new candidate effectors. In plant-pathogen interactions also miRNAs are too proving to be an important factor which cannot be neglected. During disease infection, expression levels of miRNAs are varying which in turn may be a proof of miRNA regulation of pathogen genes. Therefore, cross-kingdom RNA interference may take place between plant and pathogen. We have tested plant pathogens for possible plant miRNA availability and found their most likely targets with in the pathogen genes.
72

Alterations Of Hypothalamic Neuropeptides Involved In Food Intake And Appetite In Olanzapine Monotherapy

Sezlev, Deniz 01 September 2012 (has links) (PDF)
The mechanism of weight gain due to treatment with olanzapine, a serotonin receptor antagonist, has not been fully understood. Weight gain and food intake are under the control of neuropeptides/hormones, POMC (proopiomelanocortin), CART (cocaine and amphetamine regulated transcript), AgRP (Agouti-related peptide) and NPY (neuropeptide Y) that are synthesized and secreted from the arcuate nucleus (ARC) of hypothalamus. In this study, the altereration of the ARC neuropeptide/hormone levels both in humans and rats were determined as one of the weight gain mechanism. To examine olanzapine&rsquo / s weight gain effects, male first attack psychotic patients (pre-treatment), were hospitalized and treated for 4 -weeks (post-treatment), (n = 22), and healthy control group (n = 26) were included to the study. Case-control association design was used to analyze the changes in body mass index (BMI), peripheral leptin and the ARC neuropeptides levels. In patients, after 4-weeks of the olanzapine treatment / BMI and the waist circumference were significantly increased with average weight gain of 4.33 kg. In pre-treatment group, NPY levels were significantly lower while &alpha / -MSH, the anorexigenic product of POMC levels were significantly higher vs. control. At post-treatment, both leptin and NPY levels were significantly increased but the CART levels did not change. To further understand the underlying mechanism of olanzapine induced weight gain, the drug was orally administrated to 10 healthy male Wistar rats to analyze both the hypotalamic gene expression and peripheral levels of those candidate neuropeptides. In rats food consumption was increased and hypotalamic mRNA levels of NPY, AgRP and POMC were decreased while CART levels did not show any alteration. Consistent with the expression data, circulating levels of NPY, AgRP and &alpha / -MSH decreased significantly but CART levels were also reduced unexpectedly. In conclusion, it may be presumed that the antagonistic effect of olanzapine on the ARC neurons might be the basis for a disregulation of the neurohormones secretion which may cause weight gain in the treated psychotic patients.
73

Herausforderungen für die nachhaltige öffentliche Beschaffung in der Tschechischen Republik im Zuge der EU-Osterweiterung

Kreutzfeldt, Claudia 09 October 2004 (has links) (PDF)
Die vorliegende Ausgabe beschäftigt sich mit den Herausforderungen der nachhaltigen öffentlichen Beschaffung in der Tschechischen Republik als neues Mitgliedsland der Europäischen Union. Außerdem soll die Rolle der EU im Bereich der nachhaltigen öffentlichen Beschaffung herausgestellt werden, d. h. inwieweit die Europäische Kommission die Aktivitäten der Mitgliedsstaaten koordiniert und welche Möglichkeiten sie zur Integration von Umweltkriterien in den öffentlichen Beschaffungsprozess für zulässig hält. Im Jahr 1989 zeigte sich in der damaligen CSSR ein katastrophaler Umweltzustand. Die Wirtschaftsweise in der kommunistischen Zeit (1948 bis 1989) vernachlässigte vollkommen den Faktor Umwelt. Heute hat die nachhaltige Entwicklung in der Tschechischen Republik jedoch entscheidend an Bedeutung gewonnen. Durch den Einsatz der nachhaltigen öffentlichen Beschaffung als umweltpolitisches Instrument könnte die Umwelt in Tschechien geschützt, das Beschaffungsverhalten anderer Konsumenten beeinflusst und Unternehmen zu Produktinnovationen angeregt werden. Im Bereich der nachhaltigen öffentlichen Beschaffung koordiniert die Europäische Kommission die Aktivitäten der Mitgliedstaaten und verfolgt dabei auch eigene Ziele, wie die Schaffung eines gemeinsamen Binnenmarktes. Oberhalb festgesetzter Schwellenwerte müssen öffentliche Aufträge europaweit ausgeschrieben werden und sind offen für jedes Unternehmen. Grundsätzlich wird die Umsetzung einer nachhaltigen öffentlichen Beschaffung dabei von der Europäischen Kommission nur empfohlen. Die Tschechische Republik ist der EU am 01. Mai 2004 im Rahmen der Osterweiterung beigetreten. Im Hinblick auf den angestrebten Beitritt wurde in der Tschechischen Republik der Aufbau von Umweltinstitutionen, die Erstellung einer staatlichen Umweltpolitik und die Entwicklung des Umweltrechts stark vorangetrieben. So beschloss die tschechische Regierung im Jahr 2000, dass insbesondere der Staat seiner Verantwortung zum Schutz der Umwelt gerecht werden und bei der Beschaffung mit gutem Beispiel vorangehen sollte. Somit wurde auch in Tschechien die nachhaltige öffentliche Beschaffung als ein freiwilliges umweltpolitisches Instrument eingeführt. Dessen Potenzial, d. h. der Umfang der Ausgaben der öffentlichen Auftraggeber, betrug im Jahr 2003 ca. 18,5% des Bruttoinlandsprodukts.
74

Die Auswirkungen der Ostöffnung auf Grenzregionen am ehemaligen Eisernen Vorhang mit besonderer Berücksichtigung der Arbeitsmarktaspekte

Huber, Petra Sybille 07 1900 (has links) (PDF)
Die Arbeit befasst sich mit den Auswirkungen der Ostöffnung auf Grenzregionen entlang des ehemaligen Eisernen Vorhangs. Hierbei wird besonders auf die Veränderungen am Arbeitsmarkt eingegangen. Die grundlegende Hypothese war, dass es in den betrachteten Regionen aufgrund des externen Schocks zu einem Aufbrechen der vorhandenen Strukturen kommt. Hierbei wurde auch angenommen, dass die Regionen diesseits und jenseits des Eisernen Vorhangs jeweils unterschiedliche Auswirkungen zeigen würden, aufgrund der unterschiedlichen Ausgangslage. Die betrachteten Regionen wurden mithilfe einer Clusteranalyse in mehrere Kategorien eingeteilt. Hierbei wurden deutliche Unterschiede zwischen den Regionen der alten und neuen EU-Mitgliedländer festgestellt. Auch konnte in den österreichischen Regionen die neue Situation offensichtlich besser genutzt werden als in den deutschen Regionen. Besonders prägnant war der Einfluss der Grossregion Wien-Bratislava. (Autorenref.)
75

Evaluation Of Salt Tolerance In Sto Transformed Arabidopsis Thaliana And Nicotiana Tabacum Plants

Selcuk, Feyza 01 January 2004 (has links) (PDF)
Salinity is one of the limiting factors of crop development. Together with causing water loss from plant tissues, salinity also leads to ion toxicity. Under salt stress, increase in Ca+2 concentration in cytosol can decrease the deleterious effects of stress. The binding of Ca+2 to calmodulin initiates a signaling cascade involving the activation of certain transcription factors like STO and STZ. This signal transduction pathway regulates transport of proteins that control net Na+ influx across the plasma membrane and compartmentalization into the vacuole. Previously Arabidopsis STO was identified as a repressor of the yeast calcineurin mutation. Genetical and molecular characterization of STO / a putative transcription factor that takes role in salt stress tolerance can provide a better understanding in the mechanism of salt tolerance and development of resistance in higher plants. The aim of the present study was to amplify and clone the Arabidopsis thaliana sto gene in plant transformation vectors and use them for the transformation of Nicotiana tabacum and Arabidopsis thaliana plants via Agrobacterium tumefaciens mediated gene transfer systems. T0 and T1 progeny of transgenic plants carrying sto were analysed for the stable integration of transgenes, segregetion patterns, expression of the gene and their tolerance to salt stress. The results of the study showed that all transgenic Nicotiana tabacum lines are differentially expressing a transcript that is lacking in control plants and most transgenic lines exhibited higher germination percentages and fresh weights, lower MDA contents under salt stress. On the other hand overexpression of sto in Arabidopsis plants did not provide an advantage to transgenic plants under salt stress, however the anti-sense expression of sto caused decreased germination percentages even under normal conditions. According to the sto expression analysis of wild type Arabidopsis plants, sto was shown to be induced under certain stress conditions like cold and sucrose, whereas it remained constant in salt treatment. External application of plant growth regulators had no clear effect on sto expression, with the exception of slight induction of expression with ABA and ethylene treatments.
76

Multidrug Resistance In Locally Advanced Breast Cancer

Atalay, Mustafa Can 01 June 2004 (has links) (PDF)
ABSTRACT MULTIDRUG RESISTANCE IN LOCALLY ADVANCED BREAST CANCER ATALAY, Mustafa Can Ph. D., Department of Biotechnology Supervisor: Prof. Dr. Ufuk G&Uuml / ND&Uuml / Z June 2004, 70 pages Breast cancer is the most frequently detected cancer among women. Early diagnosis leads to long term survival when the patients are treated with surgery, radiotherapy, chemotherapy, and hormone therapy. Unfortunately, advanced disease could still be encountered in some patients resulting in a poorer prognosis. The primary treatment modality is chemotherapy for this group of patients. Drug resistance is a serious problem resulting in the use of different drugs during chemotherapy and knowing the possibility of resistance before initiating first line chemotherapy may save time and money, and most importantly, may increase patient&rsquo / s survival. Therefore in this study, multidrug resistance is studied in locally advanced breast cancer patients. The breast tissues obtained from 25 patients both before and after chemotherapy were examined for drug resistance. Reverse transcriptase polymerase chain reaction was used for the detection of mdr1 and mrp1 gene expression. In addition, immunohistochemistry technique was used for P-glycoprotein and MRP1 detection. JSB-1 and QCRL-1 monoclonal antibodies were utilized to detect P-glycoprotein and MRP1, respectively. Five patients were unresponsive to chemotherapy. In four of these patients mdr1 gene expression was induced by chemotherapy where as the fifth patient initially had mdr1 gene expression. In addition, Pgp positivity was detected in 9 patients after chemotherapy. Both the induction of mdr1 gene expression (p&lt / 0.001) and Pgp positivity (p&lt / 0.001) during chemotherapy were significantly related with clinical response. On the other hand, mrp1 gene expression and MRP1 positivity were detected in 68% of the patients before the therapy. After chemotherapy, mrp1 expression increased to 84%. Although 80% of the clinically unresponsive patients had mrp1 gene expression, the relation between mrp1 expression and clinical drug response was not strong. Thus, it can be concluded that in locally advanced breast cancer mdr1 gene expression during chemotherapy contributed to clinical unresponsiveness. However, mrp1 gene expression did not correlate strongly with the clinical response. When RT-PCR and immunohistochemistry methods are compared in terms of detection of drug resistance, it seems that both methods gave similar and reliable results.
77

Development Of A Pcr-based Specific Method For The Detection Of Aspergillus Fumigatus By Random Cdna Cloning

Soyler, Alper 01 June 2004 (has links) (PDF)
Aspergillus fumigatus is a foodborne and airborne human pathogen which produces mycotoxins such as gliotoxin, helvolic acid, fumigallin, and fumigaclavin. The most common disease caused by A. fumigatus is aspergillosis, which is often fatal, especially among AIDS, cancer, and organ-transplant patients. In this study, random cDNA cloning was performed from a cDNA library of A. fumigatus (IMI 385708) constructed on &amp / #955 / ZAP Express. Some of these clones were selected according to their insert sizes and were further subjected to sequence analysis. The sequences were then analyzed by a BLAST search (NCBI Genome Database) to determine the possible functions of these genes. Two of the clones were identified as the primase and 60S ribosomal protein L1-b genes. These genes and a third gene corresponding to the antigenic cell wall galactomannoprotein gene of A. fumigatus were used for the design of three distinct primer pairs. For the primer design, a software was written to differentiate nonconserved regions by multiple sequence alignment. Designed primers were employed in PCR experiments against genomic DNAs of different Aspergillus species. Unique bands were obtained only against A. fumigatus genomic DNA. It was concluded that this PCR-based detection method can be further developed for the rapid detection of A. fumigatus spores from air and food samples.
78

Cloning And Characterization Of Industrially Important Alpha-galactosidase Genes From The Human Pathogen Aspergillus Fumigatus

Soyler, Betul Ulviye 01 June 2004 (has links) (PDF)
In this study, molecular cloning studies were performed on the &amp / #945 / -galactosidase genes of Aspergillus fumigatus IMI 385708. This organism is an opportunistic saprophytic fungus and a human pathogen, mainly affecting immunocompromised patients. A. fumigatus is a thermotolerant fungus and can efficiently produce thermostable &amp / #945 / -galactosidase. Two different cloning strategies were undertaken in this study. A. fumigatus cDNA library, prepared previously, was screened with three different probes. No net results were obtained from these screenings. However, the DNA probes used were shown to be homologous to the &amp / #945 / -galactosidase gene (agl1) of Trichoderma reesei. After the completion of the genome project of A. fumigatus, regions with homology to &amp / #945 / -galactosidase genes were searched on the genome of A. fumigatus. PCR-based cloning studies were performed by designing specific primers for these regions. Two &amp / #945 / -galactosidase genes, namely aglA and aglB were amplified with these specific primers, sequenced, and ligated to vector pUC19. The recombinant plasmid was then used to transform E. coli XL1 Blue MRF&rsquo / cells. aglB gene consists of an open reading frame of 1684 bp containing six introns. The gene encodes a protein of 447 amino acids with a signal sequence of 22 amino acids and four N-glycosylation sites. aglA gene has an open reading frame of 1599 bp without introns. The gene encodes a protein of 532 amino acids with a putative signal sequence of 21 amino acids and four putative N-glycosylation sites. Cloning of &amp / #945 / -galactosidase genes represents a first step towards the high level expression of these enzymes in a GRAS host.
79

Transcriptional Analysis Of Hydrogenase Genes In Rhodobacter Sphaeroides O.u.001

Dogrusoz, Nihal 01 July 2004 (has links) (PDF)
TRANSCRIPTIONAL ANALYSIS OF HYDROGENASE GENES IN RHODOBACTER SPHAEROIDES O.U.001 In photosynthetic non-sulphur bacteria, hydrogen production is catalyzed by nitrogenases and hydrogenases. Hydrogenases are metalloenzymes that are basically classified into: the Fe hydrogenases, the Ni-Fe hydrogenases and metal-free hydrogenases. Two distinct Ni-Fe hydrogenases are described as uptake hydrogenases and bidirectional hydrogenases. The uptake hydrogenases are membrane bound dimeric enzymes consisting of small (hupS) and large (hupL) subunits, and are involved in uptake and the recycling of hydrogen, providing energy for nitrogen fixation and other metabolic processes. In this study the presence of the uptake hydrogenase genes was shown in Rhodobacter sphaeroides O.U.001 strain for the first time and hupS gene sequence was determined. The sequence shows 93% of homology with the uptake hydrogenase hupS of R.sphaeroides R.V. There was no significant change in growth of the bacteria at different concentrations of metal ions (nickel, molybdenum and iron in growth media). The effect of metal ions on hydrogen production of the organism was also studied. The maximum hydrogen gas production was achieved in 8.4&micro / M of nickel and 0.1 mM of iron containing media. The expression of uptake hydrogenase genes were examined by RT-PCR. Increasing the concentration of Ni++ up to 8.4&micro / M increased the expression of uptake hydrogenase genes (hupS). At varied concentrations of Fe-citrate (0.01 mM-0.1 mM) expression of hupS was not detected until hydrogen production stopped. These results will be significant for the improvement strategies of Rhodobacter sphaeroides O.U.001 to increase hydrogen production efficiency. In order to examine the presence of hupL genes, different primers were designed. However, the products could not be observed by PCR.
80

Morphometric, Mtdna And Microsatellite Analysis In Honeybee Populations (apis Mellifera L.) Of North And Northwest Iran

Jabbarifarhoud, Houman 01 September 2004 (has links) (PDF)
ABSTRACT MORPHOMETRIC, MtDNA AND MICROSATELLITE ANALYSIS IN HONEYBEE POPULATIONS (Apis mellifera L.) OF NORTH AND NORTHWEST IRAN Morphometric measurements, mitochondrial DNA analyses and 5 microsatellite loci were used to investigate variation in the honeybee populations of Iran and comparing it with the Turkish populations. Five honeybee populations were sampled from North and west north of Iran. In morphometric aspect of the study 23 characters were measured from left forewings and hindlegs of honey bee samples. The data were analysed by multivariate statistical analyses. By using mtDNA analyses length polymorphism of the intergenic region COI-COII of mitochondrial DNA was studied. After amplification of this region by the polymerase chain reaction, DraI enzyme was used for restriction of amplified region. Results of mtDNA studies show no diversity between four populations and all of them exhibit the same C1 pattern. Five microsatellite loci (A7, A24, A28, A43 and A113) were used in this studies.A high level of average heterozygosity changing between 0.611 and 0.709 was detected in Iranian honey bee populations, and a significant degree of polymorphism was observed. Although Urmia, Sarein and Viladereg populations are similar, Amol population which has located in northern Iran shows a significant difference from other populations. Result obtained form morphometric studies are supporting microsatellite analyses. By comparing data obtained form Iranian honey bee populations with Turkish population (Hakkari), western populations (Urmia, Sarein and Viladereg) are more similar to Hakkari population. It is found Amol is significantly different form other populations and better represents Iranian honeybee.

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