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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.
391

Biodegradation of Textile Materials

Arshad, Khubaib, Mujahid, Muhammad January 2011 (has links)
In this research work different textile materials were buried in soil and their biodegrading pattern will be studied after different specific period of times. / Program: Master Programme in Textile Technology
392

Development of a genetic system in Rhizobium meliloti.

Meade, Harry Melvin January 1977 (has links)
Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Biology. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / Ph.D.
393

Investigating mutability and the plasmodium falciparum chloroquine resistance transporter in drug resistant malaria parasites

Lee, Andrew Hojin January 2016 (has links)
Malaria persists today as a significant burden for a large part of the world. However, over the past few decades, a concerted effort by governments, non-governmental organizations, researchers, and community health workers worldwide has yielded progress in reducing the deadly impact of this disease. Today, some of these gains are threatened by the rise of antimalarial drug resistance, a recurring problem that has impeded global malaria reduction efforts before. Research on Plasmodium falciprum resistance to the numerous antimalarial compounds used today and in the past has made significant progress on determining which specific mutations modulate drug susceptibility and to what degree they do so. To gain a comprehensive understanding of drug resistance, we need to elucidate how and why it arises. Therefore, it is important to elucidate whether some malaria parasites acquire resistance-conferring mutations faster than others and why the native function of the genetic factors involved lend themselves to modulating drug resistance. For instance, resistance to multiple antimalarial therapies has repeatedly emerged in Southeast Asia. We investigated the long-held hypothesis that this was due to the ability of these parasites to mutate significantly faster than non-Southeast Asian strains. Elucidating whether this hypermutability phenotype accurately represents Southeast Asian parasite evolvability is important, as it can inform when resistance would be expected to next arise, particularly in the Greater Mekong Subregion in Southeast Asia. Here, we have adapted a fluctuation assay to Plasmodium falciparum and determined that some contemporaneous Cambodian parasites exhibit a mild mutator, but not a hypermutator, phenotype. We also show that this is likely driven by mutations in DNA repair genes carried predominantly by multidrug resistant Southeast Asian parasites. One of the most common genes in which drug resistance-conferring mutations occurs is the P. falciparum chloroquine resistance transporter (pfcrt). Mutations in pfcrt are associated with parasite susceptibility to many of the antimalarial compounds that have been used in a clinical setting to date. However, beyond its role in drug resistance, little is known about the native function of PfCRT. To facilitate the study of pfcrt, we have designed a zinc-finger nuclease (ZFN)-based gene engineering system that introduces a single double-strand break in intron 1 of pfcrt. Our ZFN strategy enables replacing nearly any endogenous pfcrt locus with a user-defined recombinant pfcrt allele. We show that our method of pfcrt allelic replacement is fast, efficient, and reliable. We used this system to generate a unique mutant parasite encoding a pfcrt-L272F mutation, which enlarges the parasite digestive vacuole, the lysosome-like organelle used to catabolize host-derived hemoglobin for amino acid salvage. Our results provide clear evidence that PfCRT is associated with the terminal steps of hemoglobin degradation, overall parasite fitness, and the balance of osmolytes across the digestive vacuole membrane. Bringing clarity to the native function of PfCRT can reveal how and why this single genetic factor has been and continues to be involved in the resistance to many different antimalarial compounds.
394

Desempenho de bezerros leiteiros recebendo probiótico contendo Bacillus subtilis e Bacillus licheniformis / Performance of calves receiving probiotic containing Bacillus subtilis and Bacillus licheniformis

Torrezan, Thais Manzoni 18 April 2016 (has links)
O objetivo deste estudo foi avaliar a suplementação de um probiótico composto por cepas de Bacillus subtilis e Bacillus licheniformis, fornecidos via sucedâneo lácteo, no que se refere ao escore e pH fecal, contagem de microrganismos intestinais, parâmetros sanguíneos e desempenho geral dos animais. Foram utilizados 24 animais da raça Holandês que receberam 4L/dia de sucedâneo comercial (15PB:15EE), além de livre acesso a água e concentrado inicial. O desaleitamento ocorreu na 8ª semana de vida. Os animais foram distribuídos em delineamento de blocos casualizados, em dois tratamentos: 1) Controle - sem a suplementação de probiótico; 2) Suplementação de 2g/d (1,6 x 109 UFC) de Bacillus subtilis e Bacillus licheniformis via sucedâneo lácteo. Semanalmente foram realizadas pesagens e aferições de medidas corporais (altura de cernelha, perímetro torácico e largura de garupa); e colheitas de sangue para determinação de glicose, proteína total, ureia e albumina, além de determinação de hematócrito. Foram colhidas amostras semanalmente para contagem de bactérias ácido láticas e enterobactérias e determinação de pH fecal. O monitoramento do consumo de concentrado e do escore fecal foi realizado diariamente. O peso corporal, o ganho de peso médio diário e as medidas corporais não foram alteradas (P>0,05) pela suplementação do probiótico contendo Bacillus subtilis e Bacillus licheniformis; muito embora tenham apresentado efeito significativo de idade dos animais (P<0,001). O escore fecal, pH fecal e consumo de concentrado diário também não foram afetados pela suplementação com probiótico. No entanto, o consumo de concentrado e o pH fecal sofreram influência da idade em resposta ao crescimento natural dos bezerros. A contagem de bactérias ácido láticas foi maior que número de enterobactérias durante todo o período (P<0,05). Apenas as enterobactérias sofreram efeito da idade (P<0,05), enquanto as bactérias ácido láticas permaneceram variando, porém dentro de um padrão constante. Os parâmetros sanguíneos também não foram afetados pela suplementação com probiótico (P>0,05) mas todos, com a exceção da albumina, tiveram influência da idade (P<0,001). A suplementação com o probiótico contendo Bacillus subtilis e Bacillus licheniformis via sucedâneo não apresentou benefícios no desempenho ou no metabolismo de bezerros leiteiros, bem como não reduziu a ocorrência de casos de diarreia. / The objective of this study was to evaluate the supplementation of a probiotic containing strains of Bacillus subtilis and Bacillus licheniformis, supplied via milk replacer, with regard to fecal score and pH, intestinal microorganisms count, blood parameters and overall performance of the animals. Twenty-four Holstein calves were utilized and received 4L/d of liquid diet consisting of commercial milk replacer (20CP:15EE), and had free access to water and starter concentrate. Weaning occurred at the 8th week of age. Animals were distributed in a randomized block design, in the following treatments: 1) Control - without supplementation with probiotic, 2) Supplementation: 2g/d of Bacillus subtilis and Bacillus licheniformis (1.6 x 109 CFU), via milk replacer. Every week calves were weighted and body measurements were taken (hip width, withers height and heart girth). Blood samples were drawn weekly for determination of hematocrit, glucose, total protein, urea and albumin. Fecal samples were weekly collected for lactic acid bacteria and enterobacteria couting and fecal pH determination. Concentrate starter intake and fecal scores were monitored daily. Body weight, average daily gain, and corporal measurements were not affected (P>0,05) by the supplementation of probiotic; however, presented a significant age effect (P<0,001). The fecal score, fecal pH and starter intake were not affected by probiotic supplementation (P>0.05). However, starter intake and fecal pH were affected by age due to calves\' natural growth. The acid lactic bacteria count was higher than the count of enterobacteria during the whole evaluation period. Only enterobacteria were affected by the age of animals, while acid lactic bacteria remained constant despite little variations. Blood parameters were also not affect by supplementation of probiotic (P>0.05), but all of them, except albumin concentrations, were influenced by age (P<0,001). The supplementation with probiotic containing Bacillus subtilis and Bacillus licheniformis via milk replacer presented no benefits in dairy calves performance or metabolism and did not reduced the occurrence of diarrhea.
395

Antimicrobial discovery from South African marine algae

Rufaro Mabande, Edmund January 2018 (has links)
>Magister Scientiae - MSc / Antimicrobials are chemical compounds that destroy or inhibit the growth of microorganisms. The majority of these antimicrobials are actually natural products or natural product derived with key examples being the pioneer antibiotics penicillin and cephalosporin. Antimicrobials are an extremely important class of therapeutic agents; however, the development of drug resistance and slow pace of new antibiotic discovery is one of the major health issues facing the world today. There is therefore a crucial need to discover and develop new antibacterial agents. In this study, the potential of marine algae as a source of new antibiotics was explored. Crude organic extracts and chromatographic fractions obtained from small-scale extraction of 17 different marine algae were used to prepare a pre-fractionated library that would be tested against several disease causing microorganisms. The activity of the pre-fractionated library and purified compounds was determined against a panel of drug resistant microorganisms namely Acinetobacter baumannii ATCCBAA®-1605™, Enterococcus faecalis ATCC® 51299™, Escherichia coli ATCC® 25922™, Staphylococcus aureus subsp. aureus ATCC® 33591™ and Candida albicans ATCC® 24433™. Finally, cytotoxicity tests of 50 selected library extracts and isolated compounds were done against two cell lines namely MCF-7 (breast cancer) and HEK-293 (kidney embryonic).
396

Síntese de frutooligossacarídeos pela biotransformação da sacarose por micro-organismos osmofílicos / Synthesis of fructooligosaccharides by sucrose biotransformation using osmophilics microorganisms

Silva, Juliana Bueno da 02 October 2018 (has links)
Orientadores: Gláucia Maria Pastore, Luiz Carlos Basso / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-10-02T14:43:34Z (GMT). No. of bitstreams: 1 Silva_JulianaBuenoDa_D.pdf: 2310696 bytes, checksum: 9ca677c093828e2fa9bdd9720ae5939c (MD5) Previous issue date: 2014 / Resumo: Os frutooligossacarídeos (FOS) são ingredientes de grande importância na indústria de alimentos e têm despertado muita atenção nos últimos anos por possuírem aplicações variadas e apresentarem propriedades prebióticas. O presente trabalho teve como objetivo avaliar a produção biotecnologica de FOS a partir de micro-organismos osmofílicos em um proceso de biotransformação utilizando células íntegras microbianas. As linhagens de Bacillus sp. e Aureobasidium sp, previamente isoladas de favo-de-mel e identificadas, foram primeiramente avaliadas quantos aos principais parâmetros de produção utilizando a metodologia de Superfície de Resposta, precisamente pelo Placket-Burman (PB), nos quais foram analisados 12 parâmetros para cada um dos microrganismos, dentre eles, a concentração da sacarose, inóculo, extrato de levedura, K2HPO4, (NH4)2SO4, MgSO4.7H2O, ZnSO4, MnSO4.7H2O, pH, temperatura e agitação. O Bacillus sp. apresentou 5 fatores significativos, sendo o pH, temperatura e agitação com efeitos negativos e o extrato de levedura e sulfato de amônia com efeitos positivos. Já o Aureobasidium sp. apresentou efeito positivo apenas para os parâmetros concentração de sacarose e sulfato de magnésio, sugerindo que o melaço de cana-de-açúcar, o qual era utilizado apenas para este microrganismo na etapa de cultivo do inóculo, poderia estar carreando nutrientes essenciais ao processo. A partir desta etapa, o trabalho teve continuidade apenas com a linhagem Aureobasidium sp. utilizando planejamentos experimentais sequenciais, a fim de se obter a faixa ótima de produção de FOS totais para esse processo. O estudo realizado para avaliar o efeito do melaço como meio de cultivo para o crescimento e obtenção do inóculo microbiano para o processo, demonstrou que a suplementação com nutrientes, avaliados na etapa do PB, era desnecessária, e o meio para síntese de FOS foi definido em apenas sacarose sem suplementação de nutrientes, com o inóculo na forma de suspensão celular cultivado previamente em meio a base de melaço. A produção neste momento atingia valores de 287,6 e 251,5 g/L de FOS totais e rendimentos de 72% e 63% em 24 e 48 horas respectivamente, com uma produtividade de 12 g/L.h às 24 horas de incubação. Em seguida foi realizado o planejamento fatorial fracionado para 4 variáveis definidas em tempo de cultivo e concentração do melaço, na etapa do cultivo do inóculo, e concentração de sacarose e de inóculo para a síntese de FOS, cujos apresentaram-se positivos com exceção ao tempo de cultivo que não demonstrou efeito nas condições avaliadas. Os valores de produção atingidos na etapa do fatorial foram de 333 g/L e 354 g/L de FOS totais e rendimentos de 60,5% e 64% em 24 e 48 horas respectivamente, e produtividade de 13,8 g/L.h às 24 horas de incubação. Após esses resultados, fixou-se a concentração do melaço em 10% de açúcares redutores totais, permanecendo apenas a concentração de sacarose e inóculo como variáveis para prosseguir o planejamento. A otimização desses dois fatores por Delineamento Composto Central Rotacional (DCCR), possibilitou definir 4 modelos significativos ao processo, atingindo faixas ótimas de produção para cada FOS como o GF2, GF3 e GF4, e revelou a condição ótima para o processo em 600 a 650 g/L de sacarose e de 20 a 23% de inóculo, resultando em uma produção de 351 e 374 g/L de FOS e rendimentos de 53,5% e 57% em 24 e 48 horas respectivamente, atingindo uma produtividade de 14,7 g/L.h às 24 horas de incubação. Após definida a condição ótima do processo, o xarope de cana-de-açúcar, que é o caldo concentrado, foi utilizado como substrato alternativo à substituição da sacarose pura na produção de FOS. Os valores de rendimentos obtidos foram de 54%, entretanto as concentração de FOS totais foram de 110 g/L uma vez que a concentração inicial de sacarose no xarope era de apenas 203 g/L. A maioria dos experimentos revelou que o micro-organismo manteve-se viável e em crescimento durante o período de incubação, de acordo com os valores de biomassa e atividade enzimática avaliados nos experimentos. Sendo assim, foi proposto avaliar o processo em um biorreator de bancada de 7L, cujo foi conduzido inicialmente em sistema de batelada e após as 48 horas o processo passou a ser contínuo com taxa de diluição de 0,04.h-1 por mais 72 horas, totalizando 120 horas de cultivo. A concentração média de FOS totais produzidos foi de 228 g/L e uma produtividade média foi de 9 g/L.h / Abstract: Fructooligosaccharides (FOS) are considered food ingredients with very significance for food industry that has receiving attention in the last few years, because of their functional properties for the health as prebiotics and industrial application. The objective of the present work was evaluate the biotechnological production of FOS by osmophilics microorganisms in a biotransformation process using free whole cells. Firstly the effects of production parameters using Bacillus sp. and Auerobasidium sp. strains. was employed by the Response Surface Methodology (RSM) exactly Plackett-Burman Design with 12 variables: concentration of sucrose, inoculum, yeast extract, K2HPO4, (NH4)2SO4, MgSO4.7H2O, ZnSO4, MnSO4.7H2O, pH, temperature and agitation. The Bacillus sp. showed 5 significant parameters, as pH, temperature and agitation with negative effect and yeast extract and ammonium sulfate with positive effect. The Aureobasidium sp. presents positive effect only for sucrose and magnesium sulfate concentration, which suggested the inoculum culture was caring nutrients from sugar cane molasses, that was the base of the inoculum cultivation for Aureobasidium sp. The work has continued only with Aureobasidum sp. applying sequential planning experiments to optimize the process. The experiment for evaluate the molasses effect as inoculum cultivation medium on process showed that nutrients supplementation, used in the PB design, wasn¿t necessary, consequently, the FOS synthesis medium was defined as sucrose, without nutrients supplements and the inoculum as cellular suspension previously cultivated in molasses medium. Total FOS data, at this point, reached 287.6 and 251.5 g/L with 72% and 63% of yield data at 24 and 48 hours respectively, with 12 g/L.h of productivity at 24 hours. Subsequently, the factorial planning was realized with 4 parameters as cultivation time and molasses concentration, in the inoculum cultivation step, and sucrose and inoculum concentration for the FOS synthesis. Almost all these factors showed positive effect, exception of inoculum cultivation time. The total FOS data, at this point, was 333 and 354 g/L with 60.5% and 64% of yield data at 24 and 48 hours respectively, with 13.8 g/L.h of productivity at 24 hours. Regarding these data, the molasses concentration was fixed at 10% of total reduce sugars, remaining only sucrose and inoculum concentration as variables to continue the planning. The two factors optimization was proceed by Central Composite Rotational Design (CCRD) that allowed defined 4 significant process model, aimed optimum production scales for which one FOS, as GF2, GF3 and GF4, that reveals the optimum process condition in 600 to 650 g/L of sucrose and 20 to 23% of inoculum, resulting in 351 and 354 g/L of total FOS data and 53.5% e 57% of yield data at 24 and 48 hours respectively, with 14.7 g/L.h of productivity at 24 hours. After defined the optimum process condition, the sugar cane syrup was evaluated as alternative substrate to pure sucrose for FOS production. The yield data reached was 54%, however the total FOS concentration was 110 g/L due to the small initial sucrose concentration on syrup that was 203 g/L. All the experiments showed significant microorganism growth and increase enzyme activity during the process. For this reason, the process was conducted in a 7L bioreactor, using initially batch system and after 48 hours the system was changed to continuous process with 0.04. h-1 for more 72 hours, with 120 total hours process. Data values showed the 9 g/L.h of productivity and 228 g/L of total FOS concentration / Doutorado / Ciência de Alimentos / Doutora em Ciência de Alimentos
397

Composto bokashi com inóculo nativo e comercial, farinha de penas e a disponibilidade de nitrogênio e fósforo / Bokashi fermented compost with native and commercial inoculum, poultry feather manure and the nitrogen and phosphorus availability

Diego Fontebasso Pelizari Pinto 26 March 2018 (has links)
Poucos estudos existem sobre o efeito de diferentes inóculos microbianos na produção de composto fermentado bokashi e seu efeito no solo em relação à disponibilidade de nitrogênio e fósforo. A farinha de penas é outro potencial adubo orgânico que é pouco explorado no Brasil. O presente estudo teve por objetivo avaliar o efeito dos inóculos microbianos comercial e nativo, assim como da farinha de penas, na disponibilização de nitrogênio e fósforo, e sua interferência na nitrificação no solo. Os compostos bokashi foram feitos um com inóculo coletado em solo de área de preservação permanente misturado a solo de área de cultivo e outro com inóculo comercial. Os tratamentos: bokashi com inóculo comercial (BC), bokashi com inóculo nativo (BN), mistura de farelos com inóculo comercial (FC), mistura de farelos com inóculo nativo (FN), somente mistura de farelos (F), somente aplicação do inóculo comercial no solo (TC), farinha de penas (FP) e somente solo (T) foram misturados ao solo e incubados por 84 dias. Avaliações periódicas foram feitas dentro do período de incubação, as quais mensuraram a mineralização de nitrogênio, a nitrificação, a disponibilização de fósforo, a respiração basal, o carbono da biomassa microbiana, o coeficiente metabólico, o pH e o carbono e o nitrogênio total. O nitrogênio e o fósforo disponível foram avaliados nos compostos. O bokashi foi eficiente na disponibilização de fósforo no solo, assim como nitrogênio e fósforo no composto. A mineralização de nitrogênio foi reduzida quando os farelos passaram pelo processo de bokashi. A aplicação do bokashi não interferiu na nitrificação. O BC foi mais eficiente em disponibilizar fósforo e nitrogênio no composto e no solo que o BN. O FC apresentou uma atividade biológica de decomposição mais intensa, assim como maior mineralização de nitrogênio dos compostos quando comparado ao FN. O FN aumentou o nitrogênio orgânico no solo. Ambos inóculos demonstraram pouco efeito na nitrificação e na acidez do solo. A aplicação do FP no solo apresentou grande potencial para o suprimento de nitrogênio. / There is a reduced amount of studies on the different microbial inoculum effects in bokashi fermented compost and its effects related to soil nitrogen and phosphorus availability. The poultry feather manure is another potential fertilizer with little exploration in Brazil. The present study aim to evaluate the microbial inoculum effects, commercial and native, and the poultry feather manure, in soil nitrogen and phosphorus availability and nitrification interference. The bokashi composts were made one with collected inoculum in permanent preservation area mixed with crop soil and another with commercial inoculum. The treatments: commercial inoculum bokashi (BC), native inoculum bokashi (BN), commercial inoculum bran mixture (FC), native inoculum bran mixture (FN), bran mixture (F), just commercial inoculum in soil (TC), poultry feather manure (FP) and just soil (T) were mixed with a soil and incubated for 84 days. Periodic evaluations were made in incubation period, that one has assessed the nitrogen mineralization, the nitrification, the phosphorus availability, the basal respiration, the microbial biomass carbon, the metabolic coefficient, the pH and the total carbon and nitrogen. The nitrogen and phosphorus availability was evaluated in composts. The bokashi was efficient in soil phosphorus availability, like nitrogen and phosphorus in compost. The nitrogen mineralization was reduced with bokashi application. The bokashi application did not interfered in nitrification. The BC was more efficient in phosphorus and nitrogen availability in compost and in soil then the native inoculum bokashi. The FC show more biological decomposition activity, therefore with more nitrogen mineralization in relationship with FN. The FN increased the soil organic nitrogen. Both inoculum revealed little effect in nitrification and soil acidity. The FP application in soil demonstrated great potential in nitrogen supply.
398

Ensaio de fermenta??o in vitro com aplica??o de in?culo fecal equino / In vitro fermentation assays with the application of equine faecal inoculum

FRANZAN, Bruna Caroline 22 July 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-01-31T16:50:00Z No. of bitstreams: 1 2016 - Bruna Caroline Franzan.pdf: 2183556 bytes, checksum: 2e937393a56f483356ba48da8c23210a (MD5) / Made available in DSpace on 2018-01-31T16:50:00Z (GMT). No. of bitstreams: 1 2016 - Bruna Caroline Franzan.pdf: 2183556 bytes, checksum: 2e937393a56f483356ba48da8c23210a (MD5) Previous issue date: 2016-07-22 / CAPES / This study aimed to evaluate the feces of horses as an inoculum source to apply to in vitro fermentation tests when roughage is used as the substrate. The design was completely randomized in a 2x2 factorial arrangement. The first factor is hydration time of the substrate: 0 and 12 hours; and the second factor evaluated was the feces dilution with nutritive solution (weight: weight): 1:1 and 1:3. The variables cumulative gas production and degradation of nutrients the design was completely randomized in split plots, with the effect of incubation time as subplots. Three stallions were used as feces donors. After 28 days of adaptation to the diet and management, the feces were collected directly from the rectum of animals. After collection, the feces had been mixed with the nutritive solution in the ratio (weight:weight): 1:1 and 1:3 and kept in a water bath at 39 ? C constantly sprayed with CO2. After one hour, the material was filtered and 10 ml of inoculum had been added to previously prepared bottles. The fermentation bottles were prepared as follows: put 1 g of Coastcross hay and 90 ml of nutritive solution was added at the moment of inoculation or 12 hours before inoculation procedure. The variables bacteria count after 24 h of inoculation, the dry matter degradation (DMD), the organic matter degradation (OMD) and the neutral detergent fiber degradation (NDFD) at 24, 48 and 72 h of fermentation, as well the ammonia nitrogen content (NH3-N), pH and the cumulative gases production over 72 h had been evaluated. The nonlinear regression model adjusted the cumulative gases production. The results were submitted to ANOVA 5%, and the averages compared by SNK test at 5%. There was no significant effect of hydration and dilution factors in OMD, NDFD, NH3-N and the concentration of Lactobacillus spp., Streptococcus spp., cellulolytic bacteria and total anaerobic bacteria. The significant dilution effect in the pH was observed and the significant hydration effect in DMD. The interaction between incubation time and the hydration time of the substrate was detected over the cumulative gases production, with values significantly different starting at eight hours of incubation until the end of process. There was no proper fit to the proposed model, since the L parameter was not significant. The soluble nutrients of the Coastcross hay became available due to the hydration process, therefore, has used for the initial development of the microorganisms reducing the lag phase period of 2.32 (without hydration) to 0.24 h. In conclusion, the hydration of the dehydrated substrate is a strategy that increases the fermentation substrate extension and degradation of dry matter. Moreover, lag phase time was reduced. / Este trabalho teve como objetivo utilizar as fezes de equinos como fonte de in?culo em ensaios de fermenta??o in vitro com alimentos volumosos. Utilizou-se o delineamento inteiramente ao acaso em arranjo fatorial 2x2. O primeiro fator foi o tempo de hidrata??o do substrato: 0 e 12 horas; e o segundo fator foi a dilui??o das fezes com solu??o nutritiva na rela??o (peso:peso): 1:1 e 1:3. Para as vari?veis produ??o cumulativa de gases e degrada??o dos nutrientes o delineamento utilizado foi inteiramente ao acaso em esquema de parcelas subdivididas, com o efeito tempo de incuba??o na subparcela. Tr?s garanh?es foram utilizados como doadores de fezes. Ap?s 28 dias de adapta??o ? dieta e ao manejo, as fezes foram coletadas diretamente no reto dos animais. Ap?s a coleta, as fezes foram misturadas com a solu??o nutritiva na rela??o (peso:peso): 1:1 e 1:3 e mantidas em banho maria a 39?C constantemente borrifadas com CO2. Ap?s uma hora, o material foi filtrado e adicionou-se 10 mL de in?culo em frascos previamente preparados. Nos frascos de fermenta??o colocou-se 1 g do feno de Coastcross e, 90 mL de solu??o nutritiva adicionada no momento da inocula??o ou 12 horas antes da inocula??o. Avaliou-se a contagem bacteriol?gica 24 h ap?s a inocula??o, a degrada??o da mat?ria seca (DMS), mat?ria org?nica (DMO) e da fibra em detergente neutro (DFDN) nos tempos de 24, 48 e 72 h, o teor de nitrog?nio amoniacal (N-NH3), pH e a produ??o cumulativa de gases at? 72 h, a qual foi ajustada pelo modelo de regress?o n?o linear unicompartimental. Os resultados foram submetidos ? ANOVA 5% de signific?ncia, e as m?dias comparadas pelo teste SNK ? 5%. N?o houve efeito significativo dos fatores hidrata??o e dilui??o na DMO, DFDN, N-NH3 e na concentra??o de Lactobacillus spp., Streptococus spp., bact?rias celulol?ticas e bact?rias anaer?bias totais. Houve efeito da dilui??o no pH final e efeito da hidrata??o na DMS. Houve intera??o entre o tempo de incuba??o e o tempo de hidrata??o do substrato na produ??o cumulativa de gases, com valores apresentando diferen?a significativa a partir de oito horas p?s incuba??o. N?o houve ajuste adequado ao modelo proposto, pois o par?metro L n?o foi significativo. A hidrata??o do feno de Coastcross disponibilizou nutrientes sol?veis para o desenvolvimento inicial dos microrganismos, reduzindo o per?odo de fase lag de 2,32 para 0,24 h. Conclui-se que a hidrata??o do substrato volumoso desidratado ? uma estrat?gia que aumenta o volume de gases provenientes da fermenta??o do substrato e a degrada??o da mat?ria seca, al?m disso, reduz o per?odo de fase lag.
399

Seeing the unseen: revealing invisible and visible minutiae

Forsythe, Christopher Michael 01 May 2012 (has links)
Sight is the most important of our five senses. It allows us to navigate our environment, find food and avoid danger. Sight can be used to accurately render a drawing or to recognize nuance in a form. It can also be used in more dynamic ways to parse the complicated social systems and customs that build our societies. Despite all that we can see, we are inundated with what we cannot. This inability to see can be categorized into two subdivisions: items that possess characteristics that are beyond our eye's physical capacity of perception (e.g. microscopic objects or electromagnetic radiation) and items and situations whose exact presence goes unnoticed due to our mind's conditioning from repeated exposure (e.g. glass in a window frame or halftone dots that form a printed picture). Through the use of special instruments or awareness raising techniques these invisible objects can be brought to light. Artists and their art have often played important roles in society by revealing things that go unnoticed and making them plain to see for all. These revelations can be as simple as capturing the beauty of a natural landscape or as controversial as portraying the impact of religion, gender or oppression in our communities. My most recent set of prints investigate "seeing the unseen" by meditating on the minutiae and microscopic organisms that permeate our surroundings yet escape our attention. By utilizing handmade paper's tactile qualities, juxtaposing seemingly dissimilar objects and the use of bold and often times unnatural color, I have attempted to create a space where items of different scales can exist side by side so we can revel in their wonder, discover visual similarities between objects and plainly see them with our own eyes.
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Detection of Pathogenic Bacteria and Fecal Enterococci in Recreational Water With an Evanescent Wave Fiber Optic Biosensor

Trindade, Maria Theresa 15 December 2005 (has links)
Development of a rapid method for the detection of fecal enterococci and pathogenic microorganisms in beach water was attempted utilizing an evanescent wave fiber optic biosensor. Various assay formats including a sandwich immunoassay were tested in the development of a rapid assay. Fluorophore labeled antibodies were used for specific detection of bacteria captured or adsorbed directly to the surface of a polystyrene fiber optic waveguide. Binding of the fluorescent labeled antibody to its specific target or binding of a fluorescent labeled anti-IgG within 100-1000 nm of the waveguide surface caused excitation of the fluorescent conjugate resulting in a quantifiable signal. Enterococcus faecalis, Staphylococcus aureus, Escherichia coli O157:H7, and Vibrio cholerae were used as model organisms for biosensor detection in phosphate buffered saline and seawater. Seawater samples were selectively enriched for the presence of these model organisms, which were later detected on the biosensor. The sensitivity and specificity of the biosensor was examined by testing various assay formats, sample preparations, and molecules for capture and detection. Finally, an enrichment protocol combined with filter concentration was utilized to enhance detection of low levels of enterococci. The fiber optic biosensor has the potential to be a sensitive and specific system for the detection of fecal enterococci. The lower limit of detection in seawater and phosphate buffered saline was 2.8 x 106 CFU/ml. As few as 6 CFU/100ml (0.06CFU/ml) could be detected in seawater following a 14-24 hour enrichment and concentration step. Vibrio alginolyticus was found to grow under the same enrichment conditions as the enterococci. V. alginolyticus crossreacted with the polyclonal anti-Strep group D antibody used in the immunoassay at high cell concentrations. Staphylococcus aureus was the only other organism which showed significant cross-reactivity with this antibody. The biosensor was also able to detect other bacterial pathogens in PBS and seawater. The lower limit for detection of E. coli O157:H7 was 3.6 x 105 CFU/ml. The lower limit for detection of Vibrio cholerae O1 was 1.3 x 108 CFU/ml. The antibodies used in these assays were found to crossreact with other gram negative microorganisms. The biosensor was not able to detect Staphylococcus aureus.

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