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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.
41

Distribution of Larrea tridentata in the Tucson area as determined by certain physical and chemical factors of the habitat

Yang, Tien Wei, 1921- January 1950 (has links)
No description available.
42

An analysis of changes in Sonoran desert vegetation for the years 1928-1957

Murray, Ann Virginia, 1932- January 1959 (has links)
No description available.
43

Comparative anatomy of dune plants ... /

Starr, Anna M. January 1912 (has links)
Thesis (Ph. D.)--University of Chicago, 1911. / "Reprinted from the Botanical gazette, Vol. LIV, No. 4, 1912." "Literature cited": p. 304-305. Also available on the Internet.
44

Bioprospecção de fungos endofílicos Camarops sp., Periconia atropurpurea e Pseudofusicoccum stromaticum e avaliação epigenética de Phoma sp

Gubiani, Juliana Regina [UNESP] 24 July 2015 (has links) (PDF)
Made available in DSpace on 2016-03-07T19:20:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-07-24. Added 1 bitstream(s) on 2016-03-07T19:24:01Z : No. of bitstreams: 1 000854407_20170724.pdf: 663761 bytes, checksum: 60eaa36c360bd21a72c549385424c3ff (MD5) Bitstreams deleted on 2017-07-24T11:34:16Z: 000854407_20170724.pdf,. Added 1 bitstream(s) on 2017-07-24T11:35:24Z : No. of bitstreams: 1 000854407.pdf: 8174488 bytes, checksum: 9e24d2d63d9e50b4f003bc5a41502cda (MD5) / Os fungos são considerados fontes promissoras de compostos bioativos com potencial aplicação na indústria alimentícia, agricultura e medicina, e de fato, diversos medicamentos utilizados na saúde pública são originárias de fungos. Estes são encontrados em vários ecossistemas, entre os quais podemos citar os que vivem no interior das espécies vegetais. Estes micro-organismos são denominados de endófitos e tem se revelado uma fonte promissora de metabólitos bioativos. Dentro deste contexto, este trabalho foi idealizado, objetivando a obtenção de substâncias potencialmente bioativas a partir do estudo químico e biológico dos extratos produzidos pelos fungos endofíticos Camarops sp., Periconia atropurpurea e Pseudofusicoccum stromaticum isolados de espécies vegetais do Cerrado e, o estudo epigenético de Phoma sp. isolado de espécie vegetal do Deserto de Sonora, utilizando no cultivo o modificador epigenético SAHA. Estes endófitos foram cultivados em escala reduzida em meios de cultivo líquidos e sólidos para obtenção dos extratos brutos, os quais foram submetidos a análises químicas (CCDC, HPLC e RMN de 1H) e biológicas (antifúngico, anticolinesterásico e citotóxico). Todos os extratos brutos apresentaram pelo menos uma atividade biológica, o que adicionado às análises químicas permitiram selecionar os meios de cultivo adequados para o crescimento em escala ampliada e, isolamento dos metabólitos secundários. Do cultivo de Camarops sp. no meio sólido de Milho isolou-se cinco substâncias, das quais quatro são inéditas 3-((1S,2S)-1,2-dihidroxibut-3-enil)-4-((E)-pent-1-enil)furan-2(5H)-ona (1), 3, 5, 9-trihidroxi presilfiperfolano (2), deacetilbotridial (3), ácido (E)-2,4-dimetilocta-2-enóico (4) e, ácido (E)-2,4-dimetilnon-2-enóico (5), os compostos 4 e 5 foram ativos na inibição da enzima acetilcolinesterase. Do extrato, obtido do meio líquido de Malte, de... / Fungi are considered promising sources of bioactive compounds with potential application in the food, agriculture and medicine industry, and in fact, many drugs used in public health originate from fungi. These are found in various ecosystems, among which we can mention those who live inside the plant species. These microorganisms are called endophytes and have proved to be a promising source of bioactive metabolites. Within this context, this work was carried out, aiming to obtain potentially bioactive substances from chemical and biological study of extracts produced by the endophytic fungi Camarops sp., Periconia atropurpurea and Pseudofusicoccum stromaticum isolated from plant species of the Cerrado and epigenetic studies of Phoma sp. isolated from plant species of the Sonoran Desert using in cultivation the epigenetic modifier SAHA. These endophytes were grown on small scale in liquid culture media and solid to obtain the crude extract. These were subjected to chemical analysis (TLC, HPLC and 1H NMR) and biological (antifungal, anticholinesterase and cytotoxic). All crude extracts showed at least one biological activity, which added the chemical analysis allowed to select the culture medium of appropriate for growth in large scale and isolation of secondary metabolites. The growing of Camarops sp. in solid medium of corn were isolated five compounds of which four are new 3-((1S,2S)-1,2-dihydroxybut-3-enyl)-4-((E)-pent-1-enyl)furan-2(5H)-one (1), 3, 5, 9-trihydroxy presilphiperfolane (2), deacetyl-botrydial (3), (E)-2, 4-dimetilocta-2-enoic acid (4), and (E)-2, 4-dimetilnon-2-enoic acid (5), compounds 4 and 5 were active in inhibiting the enzyme acetylcholinesterase. From the extract obtained from the liquid medium Malt, of P. atropurpurea were isolated the compounds 4,5-diethyl-3,4,5,6-tetrahydrobenzo[c][1,6]dioxecine-1,8-dione (6) and periconicina B (7). From the cultivation of P. stromaticum...
45

Bioprospecção de fungos endofílicos Camarops sp., Periconia atropurpurea e Pseudofusicoccum stromaticum e avaliação epigenética de Phoma sp. /

Gubiani, Juliana Regina. January 2015 (has links)
Orientador: Angela Regina Araujo / Banca: Ana Helena Januário / Banca: Luce Maria Brandão Torres / Banca: Geraldo Humberto Silva / Banca: Afonso Duarte Leão de Souza / Resumo: Os fungos são considerados fontes promissoras de compostos bioativos com potencial aplicação na indústria alimentícia, agricultura e medicina, e de fato, diversos medicamentos utilizados na saúde pública são originárias de fungos. Estes são encontrados em vários ecossistemas, entre os quais podemos citar os que vivem no interior das espécies vegetais. Estes micro-organismos são denominados de endófitos e tem se revelado uma fonte promissora de metabólitos bioativos. Dentro deste contexto, este trabalho foi idealizado, objetivando a obtenção de substâncias potencialmente bioativas a partir do estudo químico e biológico dos extratos produzidos pelos fungos endofíticos Camarops sp., Periconia atropurpurea e Pseudofusicoccum stromaticum isolados de espécies vegetais do Cerrado e, o estudo epigenético de Phoma sp. isolado de espécie vegetal do Deserto de Sonora, utilizando no cultivo o modificador epigenético SAHA. Estes endófitos foram cultivados em escala reduzida em meios de cultivo líquidos e sólidos para obtenção dos extratos brutos, os quais foram submetidos a análises químicas (CCDC, HPLC e RMN de 1H) e biológicas (antifúngico, anticolinesterásico e citotóxico). Todos os extratos brutos apresentaram pelo menos uma atividade biológica, o que adicionado às análises químicas permitiram selecionar os meios de cultivo adequados para o crescimento em escala ampliada e, isolamento dos metabólitos secundários. Do cultivo de Camarops sp. no meio sólido de Milho isolou-se cinco substâncias, das quais quatro são inéditas 3-((1S,2S)-1,2-dihidroxibut-3-enil)-4-((E)-pent-1-enil)furan-2(5H)-ona (1), 3, 5, 9-trihidroxi presilfiperfolano (2), deacetilbotridial (3), ácido (E)-2,4-dimetilocta-2-enóico (4) e, ácido (E)-2,4-dimetilnon-2-enóico (5), os compostos 4 e 5 foram ativos na inibição da enzima acetilcolinesterase. Do extrato, obtido do meio líquido de Malte, de... / Abstract: Fungi are considered promising sources of bioactive compounds with potential application in the food, agriculture and medicine industry, and in fact, many drugs used in public health originate from fungi. These are found in various ecosystems, among which we can mention those who live inside the plant species. These microorganisms are called endophytes and have proved to be a promising source of bioactive metabolites. Within this context, this work was carried out, aiming to obtain potentially bioactive substances from chemical and biological study of extracts produced by the endophytic fungi Camarops sp., Periconia atropurpurea and Pseudofusicoccum stromaticum isolated from plant species of the Cerrado and epigenetic studies of Phoma sp. isolated from plant species of the Sonoran Desert using in cultivation the epigenetic modifier SAHA. These endophytes were grown on small scale in liquid culture media and solid to obtain the crude extract. These were subjected to chemical analysis (TLC, HPLC and 1H NMR) and biological (antifungal, anticholinesterase and cytotoxic). All crude extracts showed at least one biological activity, which added the chemical analysis allowed to select the culture medium of appropriate for growth in large scale and isolation of secondary metabolites. The growing of Camarops sp. in solid medium of corn were isolated five compounds of which four are new 3-((1S,2S)-1,2-dihydroxybut-3-enyl)-4-((E)-pent-1-enyl)furan-2(5H)-one (1), 3, 5, 9-trihydroxy presilphiperfolane (2), deacetyl-botrydial (3), (E)-2, 4-dimetilocta-2-enoic acid (4), and (E)-2, 4-dimetilnon-2-enoic acid (5), compounds 4 and 5 were active in inhibiting the enzyme acetylcholinesterase. From the extract obtained from the liquid medium Malt, of P. atropurpurea were isolated the compounds 4,5-diethyl-3,4,5,6-tetrahydrobenzo[c][1,6]dioxecine-1,8-dione (6) and periconicina B (7). From the cultivation of P. stromaticum... / Doutor
46

Diversity, ecology, and biotechnological potential of microorganisms naturally associated with plants in arid lands

Mosqueira Santillán, María José 07 1900 (has links)
Plants naturally host complex microbial communities in which the plant and the symbiotic partners act as an integrated metaorganism. These communities include beneficial (i.e. plant growth promoting, PGP) microorganisms which provide fundamental ecological services able to enhance host plant fitness and stress tolerance. PGP microorganisms represent a potential bioresource for agricultural applications, especially for desert farming under the harsh environmental conditions occurring in hot/arid regions (i.e. drought and salinity). In this context, understanding the ecological aspects of the associated microorganisms is crucial to take advantage of their ecological services. Here, hot/desert ecosystems were selected and two contrasting plant categories were used as models: (i) wild plants (i.e. speargrasses) growing in hot-desert sand dunes and (ii) the main crop cultivated in desert ecosystems, the date palm. By using highthroughput DNA sequencing and microscopy, the ecology and functionality of the microbial communities associated with these plants were characterized. Additionally, the PGP services of bacteria isolated from date palm were explored. I found that the harsh conditions of the desert strongly affect the selection and assembly of microbial communities associated with three different speargrass species, determining a plant species-independent core microbiome always present among the three plant species and carrying important PGP traits. On the contrary, in agroecosystems where desert farming practices are used, the plant species, i.e. date palm exerts a stronger selective pressure than the environmental and edaphic factors favoring the recruitment of conserved microbial assemblages, independent of the differences in the soil and environmental conditions among the studied oases. Such selective pressure also favors the recruitment of conserved PGP microorganisms (i.e. Pseudomonas sp. bacterial strains) able to protect their host from salinity stress through the induction of root architectural changes regulated by the modification of the root system auxin homeostasis. Overall, we found that deserts are unique ecosystems that challenge the paradigm of microbial community assembly, as it was defined from studies in non-arid ecosystems. The understanding of the ecological features regulating the ecological properties of such unique microbial community assembly will be a key-step to improve the chances of successful application of ‘PGP microorganisms’ in arid agroecosystems.
47

[Papers submitted for the D.Sc. degree] / [Collected botanical papers of J.G. Wood] / [Collected reprints, 1923-1934 : botany] / [Publications of J.G. Wood] / Vegetation of South Australia. ch. 4-8 / Time factors in photosynthesis

Wood, J. G. (Joseph Garnett), 1900-1959 January 1934 (has links)
Title supplied by cataloguer. / Lacks title page and contents. / Includes bibliographical references. / 17 items : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A collection of 17 of the author's publications including a manuscript copies of chapters 4-8 of The vegetation of South Australia (published Adelaide : Govt. Printer, 1937); and,Time factors in photosynthesis; and copies of papers reprinted from various journals; all submitted as the author's Doctor of Science thesis / Thesis (D.Sc.)--University of Adelaide, 1934
48

Population studies of nocturnal rodents in two desert habitats

Massion, Dennis Daniel, 1943- January 1971 (has links)
No description available.
49

The effects of selected pre-germination treatments on six species of summer and winter annual plants of the east Mojave Desert

Earsom, James R. 01 January 1979 (has links)
No description available.
50

A study on the effectiveness of precipitation in the Salt Desert shrub type

Brewster, Sam Finley 01 May 1968 (has links)
The purpose of this study was to measure quantitatively the effectiveness of precipitation by determining the amount and timing (i.e. distribution-in-time) of plant absorption of moisture during the summers of 1965 and 1966. In addition the effectiveness of precipitation was related to some causal factors, especially those factors which help provide a procedure for calculation of this effectiveness.

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