­ì¤l¤OÅã·LÃè(AFM)¯à¦b®ð¬Û¡B¯uªÅ¡B¤Î±µªñ¥Í²z±ø¥óªº²G¬Û¤¤ª½±µ¶i¦æªí­±³æ¤À¤lªºÆ[´ú¡C¦ý¼Ë«~¤À¤l³Q©T©w«á¡A¨äµ²ºc¬O§_»P¦ÛµMª¬ºA¬ÛÃö¡A»á¥O¤H½èºÃ¡C ¥»¬ã¨s°w¹ï¶³¥À¤ùªí­±¶i¦æ¤Æ¾Ç­×¹¢¡A§Q¥ÎºëÓi(spermine)¤j¤j´£°ª¤F°òªOªí­±§lªþDNAªº¯à¤O¡C¹B¥Î»E¦X¤À¤lÃì²Î­p¤ÀªR²z½×(statistical polymer chain analysis)¡A¥H¤TºØ¤£¦Pªø«×ªº½u«¬DNA¤À¤l¡A®Ú¾ÚAFM¼v¹³¤À§O§@¤À¤l½ü¹øÁ`ªø(contour length, L)¤Î¥¼ºÝ¨âÂI¶ZÂ÷(end-to-end distance, R)ªº´ú¶q¡A¥H<R2>»PL¤§¬ÛÃö©Ê±Àª¾¼v¹³¤¤ªºDNA¤À¤lªí²{ªº¬O3D¥ßÅé®·®»ºAºc«¬(three-dimensional trapped configuration)¡A¦Ó«D¤À¤l¦b2DªÅ¶¡­«·s«Ø¥ß¥­¿Å«áªºµ²ºc¡C¥t¥~¡AÂǧïÅÜDNA¼Ë«~²Gºw¦b¶³¥À¤ù¤W°®Àꪺ®É¶¡¡A©Ò³y¦¨°òªO§lªþ¤À¤l¼Æ¥ØªºÅܤơA°t¦X¤£¥i°fÂX´²¹B°Ê¼Ò«¬±o¨ì¤F¤À¤l¥Ñ²G¬Û¨ì¹Fªí­±¿é°e¹Lµ{¤§ÂX´²«Y¼Æ¡C ¦b©Ý¾ë²§ºc酶(topoisomerase)»P¶Ê¤ÆDNA¤À¤l¤ÏÀ³¹êÅ礤¡AAFM©úÅã¿ëÃÑ¥XDNA¤À¤l¦b©Ý¾ëºc§Î¤WªºÂà¤Æ¡A¬Æ¦Üª½±µ¬Ý¨ì¸Ñ±Û¾÷¨î¤¤©Ý¾ë酶¤À¤l»PÂùªÑDNA¤¤¤@±ø³æªÑªº§@¥Î¡C

Thesis (Ph. D.)--Lehigh University, 2002. / Includes vita. Includes bibliographical references (leaves 128-134).

Th.--Sci. nat.--Orléans, 1985. / Bibliogr. p. 313-325.

Submitted by Carla Santos (biblioteca.cp2.carla@bahiana.edu.br) on 2018-11-09T13:17:23Z No. of bitstreams: 1 9.3.1 Dissertac??a??o Alzeir.versa??o final.versa??o final vers??o para corre????o VERS??O PARA TAISE.pdf: 1277616 bytes, checksum: 44bacd138d124ddbc107b4dc154e7a11 (MD5) / Approved for entry into archive by JOELMA MAIA (ebmsp-bibliotecacp2@bahiana.edu.br) on 2018-11-09T17:48:05Z (GMT) No. of bitstreams: 1 9.3.1 Dissertac??a??o Alzeir.versa??o final.versa??o final vers??o para corre????o VERS??O PARA TAISE.pdf: 1277616 bytes, checksum: 44bacd138d124ddbc107b4dc154e7a11 (MD5) / Made available in DSpace on 2018-11-09T17:48:05Z (GMT). No. of bitstreams: 1 9.3.1 Dissertac??a??o Alzeir.versa??o final.versa??o final vers??o para corre????o VERS??O PARA TAISE.pdf: 1277616 bytes, checksum: 44bacd138d124ddbc107b4dc154e7a11 (MD5) Previous issue date: 2017-10-26 / Esta pesquisa tem como objetivo principal realizar a triagem fitoqu??mica e a avalia????o das atividades antibacterianas e antif??ngicas, in vitro, das esp??cies: Canavalia brasiliensis Mart, Cassia excelsea Schrader, Genipa americana L., Copernicia cerifera Mart., Celtis iguanaea Sarg., Azadeirata indica, Myracroduon urundeuva Allem??o, Anadenanthera colubrina Vell., Bromelia laciniosa Mart. e Schinopsis brasiliensis Engl. Os extratos hidroalco??licos de diferentes partes destas plantas foram obtidos por extra????o a frio. As folhas e os caules foram secos ao ar. Em seguida, mo??dos e submetidas ?? extra????o, por 72 horas (3x) com solvente alco??lico (etanol e metanol). As solu????es alco??licas obtidas foram submetidas ?? destila????o, ?? press??o reduzida, para obten????o dos respectivos extratos, que foram utilizados no ensaio de microdilui????o em caldo para determina????o da Concentra????o Inibit??ria M??nima (CIM), conduzido segundo as normas do Clinical and Laboratory Standards Institute (CLSI), com modifica????es. Foram utilizadas bact??rias Gram-positivas: Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus e Gram-negativas: Salmonella choleraesuis, Escherichia coli, Pseudomonas aeruginosas e o fungo Candida albicans. Al??m disso, foi determinada a Concentra????o Bactericida M??nima (CBM) e realizada a triagem fitoqu??mica. Observou-se que dos extratos das folhas, das partes a??reas e dos caules das esp??cies testados, 14.81% apresentaram atividade antimicrobiana, n??o havendo diferen??a entre os percentuais de atividade entre os extratos das folhas e dos caules. Os extratos hidroalco??licos apresentaram mais atividade contra microrganismos Gram-positivos (12.04%) do que contra os Gram-negativos (2.78%). Nenhum extrato apresentou atividade contra a Candida albicans. Dos 18 extratos das 10 esp??cies testadas, 94,44% (17) apresentaram resultado positivo para taninos, excetuando-se apenas o extrato etan??lico do caule da Genipa americana L.. Os extratos etan??lico da folha da Celtis iguanacea Sarg. e do caule da Genipa americana e os extratos metan??licos das partes a??reas da Bromelia laciniosa Mart., do caule da Canavalia Brasiliensis Mart., da Celtis iguanaea Sarg. e da Myracrodruon urundeuva Allem??o deram positivo para esteroides, correspondendo a 33.33 % dos extratos testados. A presen??a de alcaloides foi identificada nos extratos etan??licos do caule da Genipa americana L., da Copernicia cerifera Mart.. e da Anadenanthera colubrina Vell. e metan??lico da Azadirachta indica, da Myrocrodruon urundeuva Allem??o e da Celtis iguanaea Sarg., o que corresponde a 33,33 % dos extratos. Os triterpenos foram identificados nos extratos etan??licos das folhas da Genipa americana L., da Celtis iguanaea Sarg., do caule da Genipa americana L. e metan??lico das folhas da Cassia excelsea Schrader, da Schinopsis brasiliensis Engl. e do caule da Celtis iguanaea Sarg., estando, portanto, presente em 38,89% dos extratos testados.

No description available.

Artificial and natural weathering studies were conducted on four dioctahedral micas found in soil parent material of the Virginia Piedmont. Emphasis was given to the relationship between loss of K (also Na in certain cases), increase in CEC, and expansion characteristics. Boiling treatments with several different solutions were used to promote artificial weathering. In terms of the three parameters of primary interest, the results were of three general types, depending upon the nature of the boiling medium. Boiling solutions of HCl and HOAc removed K and Na, but produced only slight expansion and a negligible increase in CEC. The acid solutions, being at low pH, liberated from the mineral large amounts of Al, which likely underwent hydrolysis later to form hydroxy-Al polymeric groups. These groups can occupy exchange sites, but they remain nonexchangeable. Boiling aalt solutions of NaCl and MgCl₂ removed K and Na in large amounts, produced considerable, but only a slight increase in CEC resulted. The explanation for the small increase in CEC was believed to be due also to blocking of exchange sites by nonexchangeable hydroxy-Al groups, because salts tend to accelerate the hydrolysis reaction. A boiling Na-citrate solution removed K effectively, produced marked expansion, and caused a large increase in CEC. Citrate complexes Al, which probably accounted for the high CEC. When a sample was treated with hot HCl prior to Na-citrate boiling, the loss of K and increase in CEC was stoichiometric. The equivalence was attributed to the removal of amorphous material by HCl and complexing of Al by Na-citrate. Vermiculite and kaolinite were the natural weathering products of the dioctahedral micas studies. There was a striking similarity between the artificially-produced vermiculite and that occurring under natural conditions. The product formed under both circumstances expanded to approximate 14 A. when glycerol-solvated and contracted to 10 A. upon K-saturation and heating. Although the artificial weathering media were not representative of natural weathering conditions, the basic mechanism of mica alteration apparently was similar. The soil micas altered easily in the laboratory compared to an Ontario muscovite. Thus, it was concluded that soil micas are quite different from the specimen-type micas. They may possess a lower charge or lack the structural control of specimen muscovites. The difference in ease of weathers between dioctahedral and trioctahedral micas likely is attributable to the difference in chemical composition, especially in the octahedral layer. Dioctahedral micas appear to be more strongly bonded than trioctahedral micas as a result of the higher-charged Al⁺⁺⁺ ion in the octahedral layer. This stronger bonding would tend to restrict initial alteration. Subsequent alteration also would be hindered because, as weathering proceeds, greater hydrolysis of Al in dioctahedral micas would result in more fixation of positively-charged hydroxy-Al polymers in the interlayer position. This fixed Al inhibits expansion of dioctahedral micas. In trioctahedral micas, which contain Fe and/or Mg, this type of fixation does not occur during acidic weathering. A significant finding was the occurrence of paragonite, the Na analogue of muscovite, in intimate association with muscovite. A relatively constant Na/K molar ratio of approximately one was maintained in both the parent rocks and soils. This indicated that equal molar quantities of paragonite and muscovite were present and that weathering of the two micas was similar. Paragonite is believed to be more widespread occurrence than previous work has indicated. Its influence on soil genesis, morphology, and classification may be significant. / Ph. D.

Mount Mica is a poorly zoned sodic LCT-type pegmatite consisting dominantly of quartz, albite and muscovite in the outer portions. Potassium feldspar and lepidolite are restricted to the core zone. Micas in the wall zone are chemically homogeneous, but abruptly evolve into higher Cs + Rb bearing lithian muscovites and lepidolites in the core zone. The abrupt increase of the Cs, Rb in K-feldspar, and Cs, Rb and F in muscovite, and lepidolite combined with the occurrence of highly evolved species lepidolite, pollucite, elbaite, beryl and spodumene in the core zone suggests that incompatible elements were retained in residual fluid until their concentration was high enough to initiate crystallization of incompatible-rich mineral phases. The relatively low abundance of incompatible elements in the hanging wall suggest that the fractionation process was efficient in sweeping incompatibles into the core-zone, producing proportionally small volumes inside the pegmatite with very high enrichment in incompatible elements.

Made available in DSpace on 2015-04-14T14:12:21Z (GMT). No. of bitstreams: 1 345671.pdf: 592577 bytes, checksum: 008fea4136e0eca4cd776e2c637ff6cf (MD5) Previous issue date: 2006-01-25 / Este estudo, desenvolvido em uma sala de aula de Qu?mica, tem por objetivo compreender como a constru??o de uma Unidade de Aprendizagem sobre Leis Ponderais pode contribuir para conhecimentos significativos desse componente curricular. Para tanto, a Unidade de Aprendizagem ? realizada por meio de atividades diversificadas, buscando atender ?s necessidades dos alunos. A partir da?, procura-se explorar as possibilidades metodol?gicas que uma Unidade de Aprendizagem propicia, dando ?nfase ao aprender a aprender. Os dados discutidos neste trabalho foram colhidos em uma turma de primeira s?rie do Ensino M?dio, com trinta e cinco alunos, de uma Escola T?cnica Estadual de Porto Alegre, ao longo do primeiro trimestre do ano letivo de 2004. O processo envolve observa??es, registros di?rios e question?rios. O trabalho ? elaborado levando em considera??o uma abordagem qualitativa, sendo a fenomenologia a op??o metodol?gica adotada. Sobre a an?lise dos dados resultantes emergem tr?s ess?ncias: a complexifica??o do conhecimento pelo sujeito, o aluno frente ao processo ensino-aprendizagem e o aluno frente aos conte?dos selecionados. Mostra ainda que as Unidades de Aprendizagens servem como um caminho poss?vel para os professores superarem as pr?ticas metodol?gicas tradicionais e avan?arem na compreens?o de sua pr?pria a??o docente. O processo de pesquisa viabiliza uma reflex?o sobre a concep??o de aprendizagem significativa. As considera??es finais apontam para a validade de utilizar-se essa proposta metodol?gica, em sala de aula, a fim de possibilitar a aprendizagem significativa em Qu?mica.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:25:05Z No. of bitstreams: 1 DIS_CRISTIANO_CENTENO_SPECHT_COMPLETO.pdf: 1860927 bytes, checksum: 08252d5fbed6487955580648a6527a8a (MD5) / Made available in DSpace on 2017-06-30T18:25:05Z (GMT). No. of bitstreams: 1 DIS_CRISTIANO_CENTENO_SPECHT_COMPLETO.pdf: 1860927 bytes, checksum: 08252d5fbed6487955580648a6527a8a (MD5) Previous issue date: 2017-01-18 / This research seeks to answer the following research question. How are questions asked and what are the consequences for learning the questions asked by four teachers and 455 high school students during chemistry classes in schools in an inner city of Rio Grande do Sul? During the research, 1,178 questions were annotated in 18 high school classes of public and private schools in the sweet coast of the state of Rio Grande do Sul. After observations made in 40 chemistry classes. The questions were analyzed under the focus of their demand and their profile, having been classified and analyzed according to Roca, M?rquez and Sanmart? (2013). The questions were classified according to the content Coll et al. (1998). The conduct of the teachers in front of the questions in the chemistry classes were treated through the Textual Analysis Discusive - ATD emerging five categories of analysis. We also analyzed the questions according to the management of the classroom emerging nine categories that were analyzed according to the ATD. The semi-structured interviews with the investigated teachers were established "a priori" categories that were also analyzed by the ATD. The results of the interviews reinforce the results of the other analyzes. The result of the analysis of the collected information can be perceived that these questions are, for the most part, informative profile. Besides the questions asked in the majority by the teachers, it is intended to lead the reproduction of the disciplinary content endorsed in the textbooks. There are few questions asked in chemistry classes to provide an investigation. Therefore the didactic model of the investigated teachers that prevails in this research is to transmit the knowledge to the students. / Esta disserta??o apresenta os resultados de uma investiga??o realizada sobre as perguntas de professores e estudantes presentes em aulas de Qu?mica. Buscou responder ? seguinte quest?o de pesquisa: De que modo as perguntas s?o valorizadas por professores e a que condutas docentes elas levam em aulas de Qu?mica em escolas de uma cidade interior do Rio Grande do Sul? Para a investiga??o, foram coletadas 1.178 perguntas obtidas da observa??o de 40 aulas de Qu?mica, de quatro professores e 455 estudantes, em 18 turmas de ensino m?dio de escolas p?blicas e privadas da regi?o da Costa Doce do Estado do Rio Grande do Sul. As perguntas foram analisadas sob o enfoque de sua demanda e de seu perfil, tendo sido classificadas e analisadas de acordo com Roca, M?rquez e Sanmart? (2013). Ainda foram classificadas as perguntas conforme o conte?do na perspectiva de Coll et al (1998). A conduta dos professores diante as perguntas nas aulas de qu?mica foram tratadas por meio da An?lise Textual Discusiva ? ATD, emergindo cinco categorias de an?lise. Tamb?m foram analisadas as perguntas na perspectiva da gest?o da sala de aula, emergindo nove categorias que foram analisadas. Foram tamb?m realizadas entrevistas semiestruturadas com os professores participantes da pesquisa, sendo, neste caso, produzidas categorias ?a priori?. Os resultados das entrevistas refor?am o resultado das outras an?lises, que permite observar que a maioria das perguntas prov?m dos professores, o que remete a um ensino transmissivo e reprodutivo, muito comum nos livros did?ticos. Possibilita concluir tamb?m que as perguntas de estudantes e professores s?o, em sua maioria, de perfil informativo, pois ? muito pequeno o n?mero de perguntas manifestas nas aulas observadas com potencial para investiga??o, o que caracteriza um modelo did?tico em que prevalece a transmiss?o do conhecimento aos estudantes.

Made available in DSpace on 2015-04-14T14:46:03Z (GMT). No. of bitstreams: 1 429676.pdf: 1621591 bytes, checksum: eadc8d65a3f41853ba3e4a25f7893bc5 (MD5) Previous issue date: 2011-03-01 / A economia solid?ria constitui realidades geradoras de temas e discuss?es que pautam diversos projetos e a??es no contexto brasileiro. Existem diferentes defini??es e sentidos que caracterizam essas novas pr?ticas de gera??o de trabalho e renda, comumente chamados de economia solid?ria. O presente estudo objetiva captar nos estudos acad?micos, e nas realidades cooperativas, como s?o constru?dos os sentidos e valores para a no??o economia solid?ria. Realizamos o mapeamento das principais obras de autores tidos como refer?ncia sobre o tema, a an?lise de alguns trabalhos acad?micos na ?rea das Ci?ncias Sociais que realizaram estudos de caso em cooperativas e uma pesquisa etnogr?fica realizada em duas cooperativas com distintas vincula??es com a no??o economia solid?ria. Desta forma, buscamos uma abordagem que permitiu a problematiza??o emp?rica desta no??o em tr?s n?veis de representa??o, que nos informa sobre os diferentes sentidos e valores atribu?dos ? no??o de economia solid?ria.