• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 102
  • 24
  • 5
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 168
  • 37
  • 35
  • 31
  • 30
  • 29
  • 26
  • 20
  • 18
  • 17
  • 17
  • 16
  • 15
  • 15
  • 14
  • 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

Population structure and genetics of the European lobster Homarus gammarus

Hughes, Greta January 2000 (has links)
No description available.
12

Mordet i salladsdisken : utveckling av en PCR-baserad laboration för gymnasiet

Hedqvist, Niklas January 2008 (has links)
<p>Det har nyligen skett ett mord i salladsdisken i närbutiken. Så börjar inledningen till detta arbete. Syftet med studien var att ta fram en PCR-baserad genetiklaboration med RAPD-primer som är lärorik och intressant för gymnasielever i de naturvetenskapliga ämnena. RAPD är en metod där endast en primer används, till skillnad från de flesta andra PCR-metoder som använder två stycken primer. Laborationen har aldrig gjorts förut, vilket lett till att en stor del av arbetets tyngd ligger i att metodutveckla laborationen och sedan testa laborationen på en testgrupp. Testgruppen bestod av 9 gymnasieelever som läser naturkunskap B. Resultatet visade att 8 av de 9 elever som gjorde laborationen ansåg att laborationen bör ingå i naturkunskap B. Enkätundersökningen visar även att genetiklaborationen med RAPD primer höjde intresset för genetik och genteknik hos försökspersonerna. Slutsatsen är att laborationen lämpar sig mycket väl för att öka intresset för genetik och genteknik bland gymnasieelever.</p>
13

Mordet i salladsdisken : utveckling av en PCR-baserad laboration för gymnasiet

Hedqvist, Niklas January 2008 (has links)
Det har nyligen skett ett mord i salladsdisken i närbutiken. Så börjar inledningen till detta arbete. Syftet med studien var att ta fram en PCR-baserad genetiklaboration med RAPD-primer som är lärorik och intressant för gymnasielever i de naturvetenskapliga ämnena. RAPD är en metod där endast en primer används, till skillnad från de flesta andra PCR-metoder som använder två stycken primer. Laborationen har aldrig gjorts förut, vilket lett till att en stor del av arbetets tyngd ligger i att metodutveckla laborationen och sedan testa laborationen på en testgrupp. Testgruppen bestod av 9 gymnasieelever som läser naturkunskap B. Resultatet visade att 8 av de 9 elever som gjorde laborationen ansåg att laborationen bör ingå i naturkunskap B. Enkätundersökningen visar även att genetiklaborationen med RAPD primer höjde intresset för genetik och genteknik hos försökspersonerna. Slutsatsen är att laborationen lämpar sig mycket väl för att öka intresset för genetik och genteknik bland gymnasieelever.
14

Caracterización molecular de especies del género Malassezia

Hernández Escareño, Jesús Jaime 09 June 2005 (has links)
No description available.
15

Identification and confirmation of molecular markers and orange flesh color associated with major QTL for high beta-carotene content in muskmelon

Napier, Alexandra Bamberger 15 May 2009 (has links)
Beta-carotene presence or absence in muskmelon is controlled by two genes, green flesh gf and white flesh wf. In its dominant form the wf gene is responsible for orange flesh color; however, the epistatic interactions of gf and wf can create three flesh colors: orange, white and green. Two F2 populations, consisting of 77 greenhouse grown and 117 field grown plants, from the cross of ‘Sunrise’ (white fleshed) by ‘TAM Uvalde’ (orange fleshed), were used to examine the relationships of beta-carotene content, flesh color, and flesh color intensity. Bulk segregent analysis was used with RAPD markers to identify molecular markers associated with high beta-carotene content. Flesh color and flesh color intensity both had significant relationships with beta-carotene content. A significant correlation between total soluble solids and beta-carotene content was also found. Molecular markers were identified in both F2 populations and all significant, associated markers from ‘TAM Uvalde’ were linked with WF. A single QTL was also found to be linked with the WF locus. The identified QTL can be used to screen potential breeding lines for high beta-carotene. It was also confirmed that the visual ratings of flesh color intensity can be reliably used to select high beta-carotene content melons.
16

Genetinės įvairovės tyrimas pelkinės uolaskėlės (Saxifraga hirculus L.) populiacijose / Analysis of genetic diversity in yellow marsh saxifrage (saxifraga hirculus l.) populations

Naugžemys, Donatas 08 September 2009 (has links)
Donatas Naugžemys Genetinės įvairovės tyrimas pelkinės uolaskėlės (Saxifraga hirculus L.) populiacijose SANTRAUKA RAPD metodu buvo tirta pelkinės uolaskėlės (Saxifraga hirculus L.) genetinė įvairovė. Ištirtos penkios populiacijos iš skirtingų Lietuvos rajonų. Šiuo metodu gauti 93 lokusai, iš kurių 71% buvo polimorfiški. Nustatytas ryšys tarp Nei genų įvairovės ir tirtų populiacijų dydžio. Didžiausias DNR polimorfizmas nustatytas Merkinės (86,36%), o mažiausias – Juodlės populiacijoje (71,21%). UPGMA ir PCO metodai išryškino tirtų populiacijų genetinį savitumą. AMOVA parodė gana aukštą diferenciacijos lygį tarp tirtų S. hirculus populiacijų, kuris buvo lygus 27%. Genetinis atstumas tarp populiacijų svyravo nuo 0,168 iki 0,258. Merkinės ir Juodlės populiacojose buvo identifikuota keletas populiacijoms specifinių lokusų. Koreliacijos tarp tirtų populiacijų genetinių ir geografinių atstumų neaptikta. Kadangi visi tirti 76 augalai buvo genetiškai skirtingi, galima manyti, kad S. hirculus populiacijos atsinaujina iš sėklų sudygusiais augalais. / Donatas Naugžemys Analysis of genetic diversity in yellow marsh Saxifrage (SAXIFRAGA HIRCULUS L.) populations SUMMARY We used RAPDs (random amplified polymorphic DNAs) to analyse genetic diversity in the arctic – alpine yellow marsh Saxifrage (Saxifraga hirculus L.) that is considered as glacial relict. Five populations from different regions of Lithuania were studied. A total of 76 individuals were included in this research. In the RAPD analysis 93 loci we detected, of which 71&#61477; were polymorphic. All studied plants showed different RAPD phenotypes. The percentage of polymorphic bands and Nei’s gene diversity within populations correlated with population size. UPGMA and PCO analyses showed genetic specificity of studied populations. AMOVA revealed rather high level of differentiation among studied populations of S. hirculus. The interpopulation variance component accounted for 27%. The genetic distance between populations ranged from 0.168 to 0.258. Some population specific minor loci were identified in Merkinė and Juodlė populations. There was no correlation found between genetic and geographic distance of studied populations. Our results suggest that sexual reproduction plays a significant role in the establishment of genetic structure of S. hirculus populations.
17

Hibridinės drebulės palikuonių in vitro genetinis įvertinimas RAPD metodu / Genetic analysis of hybrid aspen offsprings in vitro using rapd

Gotoveckienė, Elena 09 July 2011 (has links)
Tuopų genties medžiai paprastoji drebulė Populus tremula ir smulkiadantė tuopa (kanadinė drebulė) Populus tremuloides yra vieni iš labiausiai paplitusių medžių Europoje bei Šiaurės Amerikoje. Šio tyrimo metu buvo išanalizuota dviejų Populus tremuloides and Populus tremula hibridų (augančių Lietuvoje, Kauno rajone) ir 50 jų palikuonių genetinė įvairovė bei giminingumas naudojantis atsitiktinai pagausintos polimorfinės DNR (RAPD) metodą. Šio darbo tikslas buvo nelaukiant hibridinių Populus medžių amžiaus brandos RAPD metodu įvertinti genetinę jų įvairovę ir giminingumą. Tyrimų vykdymui buvo iškelti uždaviniai: RAPD metodu nustatyti pasirinktų hibridinių drebulių genetinę įvairovę bei giminingumą, naudojamų RAPD reakcijoms pradmenų tinkamumą šiems drebulių hibridams, pradmenų informatyvumą. Įvertinta 50 hibridinės drebulės medžių palikuonių, regeneravusių mezginių kultūroje, genetinė įvairovė RAPD metodu. Hibridinės drebulės medžių palikuonių DNR polimorfizmo tyrimuose naudoti pradmenys Roth 170-02, Roth 170-03 ir Roth 170-10 pasižymėjo informatyvumu: po amplifikacijos elektroforegramose visada matėsi aiškūs įvairaus dydžio PGR produktai, ir atitinkamai gauta 17, 13 ir 10 fragmentų. Pradmenys Roth 170-01 ir 170-04 buvo mažai informatyvūs tirtų drebulių atveju. Pradmuo Roth 170-08 neinformatyvus, netinkamas tirtų drebulių RAPD analizei. Pagal RAPD rezultatus galima teigti, jog drebulių palikuonys buvo giminingesni nr.9 motininiam individui, nei nr.8 tėviniam individui. Genetiškai... [toliau žr. visą tekstą] / Trees of the poplar genus Populus tremula and Populus tremuloides are very common in Europe and North America. The genetic diversity and relation of two Populus tremuloides and Populus tremula hybrids (growing in Lithuania, Kaunas district) and 50 their offsprings were studied using random amplified polymorphic DNA method. The aim of this study was to estimate genetic relation and diversity of immature Populus trees in vitro and their parents using RAPD. The tasks of this study were: 1) evaluate genetic relation and diversity of selected hybrid aspens, 2) evaluate suitability and efficiency of used primers for these aspen hybrids. Primers used in this study Roth 170-02, Roth 170-03, and Roth 170-10 were informative. The results of electrophoresis using these primers were always discovered. Moreover there were identified a lot of fragments (40) using mentioned primers. Therefore these primers were effective in genetic relation and diversity studies of analysed P.tremula and P.tremuloides hybrid aspens. However primers Roth 170-01 and 170-04 in this case were little informative. The primer Roth 170-08 wasn’t informative, so it was unsuitable for RAPD analysis. According to RAPD results it was found that offsprings of aspens were more related to their mother individual (no.9) than to their father individual (no.8). The most closely RAPD based genetic distance found between individuals no.39 and no.40 (GDxy=0.05714), no.2 and no.20 (GDxy=0.10000), and no.7 and no.10 (GDxy=0.1025... [to full text]
18

Phylogenetic and antibiotic resistance variance amongst mastitis causing E. coli : the key to effective control / Daniël Johannes Goosen

Goosen, Daniël Johannes January 2012 (has links)
Environmental pathogens, such as Escherichia coli and Streptococcus uberis, are currently the major cause of mastitis within dairy herds. This leads to severe financial losses, lower production rates and deterioration of the general health of the herd. E. coli mastitis is becoming a major threat to high milk-producing dairy herds. This is because of its increasing resistance to antibiotics, rendering antibiotic treatment regimes against E. coli infections mostly ineffective. The aim of this study was to develop a method to select mastitis causing E. coli isolates for the formulation of effective herd specific vaccines. Two methods, namely a genotyping method (Random Amplification of Polymorphic DNA; RAPD) and an antibiogram based method, were used. A dairy farm milking approximately 1000 Holstein cows in the Darling area, Western Cape Province, was selected for this study. The study was conducted over a period of 48 months and mastitis samples were analysed for mastitis pathogens. Antibiogram testing (disk diffusion method) and an in-house developed RAPD analysis method were used to analyse the E. coli isolates. A total of 921 milk samples were analysed from which 181 E. coli isolates were recovered. The number of all other common mastitis pathogens combined was 99 isolates (Streptococcus uberis 18, Streptococcus dysgalactiae 46, Streptococcus agalactiae 1, Staphylococcus epidermidis 21, Arcanobacterium pyogenes 13). All E. coli isolates, except for one, were resistant to at least three antibiotics. Antibiotic variance profiles were also highly erratic. The RAPD analysis revealed high levels of polymorphisms and clear epidemiological trends were observed over time. No similarities in the variance profiles between the antibiotic variance data and phylogenetic data were observed. Formalin inactivated autogenous vaccines were produced containing E. coli isolated from the herd. The vaccines were formulated using the RAPD or antibiogram data of the E. coli isolates. A total of 5 vaccines were formulated using RAPD data (Rvaccines) and one vaccine was formulated using antibiotic variance data (A-vaccine). The RAPD formulated vaccines were more effective than the antibiotic variance formulated vaccine. After each R-vaccination, the number of E. coli mastitis cases declined within the herd. The A-vaccinations seemed to have had no effect, which lead to a rise in E. coli mastitis cases. RAPD analysis on new emerging isolates was able to detect genetic variation from vaccine strains, which in turn facilitated the formulation of new updated vaccines with higher effectiveness than the previous vaccine. Mastitis data prior to and after the vaccination period revealed significant higher incidences of mastitis in the herd than during the vaccination period. This study demonstrated that sufficient sampling practices coupled with a reliable genotyping method, resulted in the formulation of updatable vaccines which were highly effective in controlling E. coli mastitis within the herd. / Thesis (M Environmental Sciences)--North-West University, Potchefstroom Campus, 2012
19

Molekulargenetische Untersuchungen zur Abgrenzung von Populationen des Maiszünslers Ostrinia nubilalis Hübner als eine Voraussetzung für das Insektenresistenzmanagement (IRM) von Bacillus thuringiensis-Mais (Bt-Mais)

Liebe, Danila. Unknown Date (has links)
Universiẗat, Diss., 2004--Giessen.
20

BIOLOGIA REPRODUTIVA E DIVERSIDADE GENÉTICA EM JABUTICABEIRAS (Myrciaria spp., Myrtaceae)

Vilela, Regina Célia Freitas 20 August 2013 (has links)
Submitted by Mendes Eduardo (dasilva@ufba.br) on 2013-08-20T14:39:05Z No. of bitstreams: 1 Dissertacao Regina.pdf: 1923938 bytes, checksum: c28a972637eedda34db6547b68fdd7f0 (MD5) / Approved for entry into archive by Alda Lima da Silva(sivalda@ufba.br) on 2013-08-20T21:00:22Z (GMT) No. of bitstreams: 1 Dissertacao Regina.pdf: 1923938 bytes, checksum: c28a972637eedda34db6547b68fdd7f0 (MD5) / Made available in DSpace on 2013-08-20T21:00:22Z (GMT). No. of bitstreams: 1 Dissertacao Regina.pdf: 1923938 bytes, checksum: c28a972637eedda34db6547b68fdd7f0 (MD5) / Cnpq / Este trabalho teve como objetivos principais investigar os fatores ecológicos envolvidos no sistema de reprodução de espécies em simpatria de jabuticabeiras (Myrciaria spp.). Para isso, foram realizados estudos quanto ao comportamento da floração, biologia floral e sistema reprodutivo, aliando estes dados aos dados genéticos obtidos através de marcadores moleculares tipo RAPD. Foram realizados cruzamentos interespecíficos para avaliar a capacidade de formação de híbridos e investigar a presença de mecanismos de isolamento reprodutivo pós-zigóticos existentes. O trabalho foi conduzido em uma população ex situ de jabuticabeiras de setenta e uma plantas de dezoito táxons, em Minas Gerais. As espécies estudadas quanto à biologia floral e sistema reprodutivo foram Myrciaria cauliflora, Myrciaria jaboticaba, Myrciaria coronata e Myrciaria trunciflora. Para os dados de comportamento da floração e diversidade genética foram estudadas todas as plantas da população. As flores das quatro espécies avaliadas são caulifloras, hermafroditas, brancas e tetrâmeras. A floração ocorreu principalmente da 2ª quinzena de setembro a 1ª quinzena de outubro, sendo que algumas plantas apresentaram períodos de floração variáveis e mesmo florações extemporâneas. A antese ocorre entre 05h00min e 07h00min. Na fase de pré-antese e antese os grãos de pólen se apresentaram viáveis e os estigmas receptivos. O pólen é o maior recurso oferecido aos visitantes. O visitante floral mais frequente e abundante foi a abelha Apis mellifera. A jabuticabeira é uma planta autocompatível e os cruzamentos bidirecionais de polinização interespecífica entre M. trunciflora x M. cauliflora e entre M. jaboticaba x M. coronata, produziram pegamentos de 22 a 27% e uma proporção de frutos abortados precocemente. O comportamento da floração foi realizado para os dezoito táxons da população. A inexistência de períodos distintos de florescimento entre eles e juntamente com a similaridade entre a morfologia floral, horário da antese e o tipo de polinizador, podemos concluir que não há impedimentos ecológicos para o intercruzamento entre os táxons. O desenvolvimento de frutos e a germinação das sementes resultantes dos cruzamentos interespecíficos confirmam o resultado encontrado na análise genética, onde os genótipos se mostraram próximos entre si, sem resolução de grupos específicos. Deste modo, podemos concluir que não há barreiras ao cruzamento entre os táxons estudados e, embora seja indicada a análise com outras ferramentas genéticas para corroborar os dados obtidos neste trabalho, sugere-se que este grupo deveria ter sua taxonomia revisada. / Salvador (BA)

Page generated in 0.023 seconds