Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Oct. 31, 2007). Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. "August 2008" Includes bibliographical references.

Thesis (M.P.H.)--University of Texas Health Science Center at Houston, School of Public Health, 2007. / Source: Masters Abstracts International, Volume: 46-04, page: 2045. Adviser: Thomas Stock. Includes bibliographical references.

This thesis refines and develops understanding of the ecological and climatic characteristics of early Middle Pleistocene (MIS 19-13, c. 780-430 ka) interglacial environments in Britain. This period is characterised by globally muted (i.e. low amplitude) glacial-interglacial cycles, which increased in amplitude c. 430 ka with the Mid-Brunhes Transition (MBT). However, the influence of these global climatic characteristics on climates and ecology at regional and local scales is yet to be fully understood. Local ecological processes, particularly disturbance processes, have also received limited attention in pre-Holocene interglacial settings, despite their likely importance for vegetation and habitat structure. Chapters 4, 5 and 6 present in-depth multi-proxy palaeoenvironmental studies from three early Middle Pleistocene sites: West Runton, Pakefield and Brooksby. A combination of Coleoptera, pollen, coprophilous fungal spores, microcharcoal and sedimentology is used to reconstruct local ecological attributes for each site. Multivariate analyses of these datasets indicate the importance of disturbance processes (herbivore activity, wildfire, hydrogeomorphic processes) in driving and maintaining local vegetation structure and habitat heterogeneity. This is explored further (in Chapter 8), emphasising the apparent importance of site-specific factors, rather than those shared between sites, in determining the relative influence of each disturbance factor. In Chapter 7, new approaches to the coleopteran Mutual Climatic Range (MCR) method are applied to a suite of coleopteran records from interglacial sites spanning the Middle and Late Pleistocene (c.712-126 ka, MIS 17-5e). Summer temperatures, winter temperatures and temperature seasonality are reconstructed, to test whether there is evidence for MBT expression in Northwest European thermoclimates. No evidence for this is found, and it is suggested (in Chapter 8) that MBT expression in this region may instead be reflected in hydroclimatic variables (e.g. enhanced annual precipitation). Finally, it is suggested that disturbance processes and potentially wetter climates were beneficial to contemporary Lower Palaeolithic populations in Northwest Europe.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Lectinas representam um grupo diversificado de proteÃnas, tanto em termos de tamanho e estrutura, quanto com relaÃÃo Ãs atividades biolÃgicas que desempenham sobre diferentes organismos. A maioria das lectinas tem sido isolada de plantas e algumas podem exercer atividades antifÃngicas marcantes. Este trabalho apresenta o efeito de cinco lectinas estruturalmente relacionadas, as quais foram purificadas, respectivamente, das sementes de Canavalia ensiformis (ConA), C. boliviana (Cbol), C. maritima (ConM), C. brasiliensis (ConBr) e C. gladiata (ConG), sobre o crescimento in vitro dos fungos fitopatogÃnicos Mucor sp., Rhizoctonia solani, Colletotrichum musae e C. lindemuthianum. No sentido de determinar o efeito das lectinas, os esporos fÃngicos foram devidamente isolados, tratados com cada uma das lectinas na concentraÃÃo de 500 μg/mL durante 24 horas e entÃo inoculados para crescimento a 27ÂC em placas de poliestireno de 96 poÃos contendo caldo batata dextrose. O crescimento dos fungos foi avaliado em diferentes tempos atravÃs da determinaÃÃo da densidade Ãptica a 620 nanÃmetros. O controle negativo foi feito com NaCl 0,15 M. No sentido de verificar se o efeito das lectinas sobre o crescimento fÃngico era meramente proteico, os fungos foram crescidos na presenÃa de albumina sÃrica bovina (BSA). Os resultados mostraram que o crescimento de Mucor sp. foi diminuÃdo quando seus esporos foram tratados com ConA. Por outro lado, todas as outras lectinas promoveram o aumento de seu crescimento. Com relaÃÃo Ãs outras espÃcies, observou-se que o crescimento fÃngico à aumentado quando os esporos sÃo tratados com as lectinas. / Lectins represent a diversified group of proteins, both in terms of size and structure, as well as in relation to biological activities that they play on different organisms. Most of lectins have been isolated from plants and some of them can exert remarkable antifungal activities. This work shows the effect of five structurally related lectins, which were purified from the seeds of Canavalia ensiformis (ConA), C. boliviana (Cbol), C. maritima (ConM), C. brasiliensis (ConBr) and C. gladiata (ConG), respectively, on the in vitro growth of phytopathogenic fungi Mucor sp., Rhizoctonia solani, Colletotrichum musae and C. lindemuthianum. In order to determine the effect of lectins, fungal spores were properly isolated, treated with each lectin in a concentration of 500 μg/ml for 24 hours and then inoculated to growth at 27ÂC in 96-well polystyrene plates containing potato dextrose broth. The fungal growth was assessed at different times by measuring the optical density at 620 nanometers. The negative control was performed with 0.15 M NaCl. In order to verify if the effect on fungal growth occurred merely by the presence of protein, the fungi were grown in the presence of bovine serum albumin (BSA). The results showed that the growth of Mucor sp. is decreased when spores were treated with ConA. On the other hand, all the other lectins enhanced its growth. With respect to other species, it was observed that fungal growth is increased when the spores were treated with lectins.

In this thesis, we explore the benefits of microencapsulating isoniazid and pyrazinamide within sporopollenin exine capsules derived from Lycopodium clavatum. Sporopollenin is a natural biopolymer, which is extracted from the outer shell of pollen grains. These hollow microcapsules can encapsulate and release drug actives in a controlled manner and possess many other advantages such as homogeneity in morphology and size, resilience to both strong acids and bases, they have antioxidant properties as well as UV protection to protect the material inside the microcapsule. Compared to artificial microcapsules, sporopollenin’s muco-adhesion to intestinal tissues contributes greatly to the extended contact of the sporopollenin with the intestines leading to an increased efficiency of delivery of drugs. The hollow microcapsules can be easily filled with a solution of the active or active in a liquid form by simply mixing both together. The drug actives are released in the human body depending on pH factors. Active release can otherwise have controlled by adding a coating on the shell, or co-encapsulation with the active inside the shell so that high drug concentrations are delivered to the site of infection. Encapsulation of the drug active will possibly improve therapeutic abilities of the drugs; simplify the treatment of TB-HIV coinfections by eliminating troublesome drug-drug interactions and drastically reduce or eliminates side effects. The SECs were loaded using a passive filling method. The drug active (0.1 g) was dissolved in a solvent and mixed with the SECs (0.1 g) for 10 minutes. After mixing for 10 minutes, the solvent was removed by a rotary evaporator and dried to a constant mass. The surface of the sporopollenin exines were analysed on a FTIR to observe if there are any drug deposits on the surface of the SECs. The loading efficiency and drug release percentage was determined by using calibrations curves and analysed on a UV-vis spectrophotometer. Further work has been proposed in which to characterize the SECs further and producing coated tablets from loaded SECs.

Bacillus subtilis (ATCC 19659) were damaged by exposure to various concentrations of glutaraldehyde, as shown by decreased germination rates. The damage caused was repaired or otherwise obviated by the presence of sodium lactate in the holding medium. When two different salts of lactic acid were compared for ability to overcome the effect of glutaraldehyde, it was found that calcium salt of lactate was more effective than the sodium salt. The damage repair system involved l-alanine, lactate and either the sodium or calcium ions. The study involved in determining the difference in efficiency of spore repair was due to an organic or an amino acii snowed that the presence of two carboxylic functional groups did not effectively alter the reactivity.

Orientador: Mirna Lucia Gigante / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-30T23:01:21Z (GMT). No. of bitstreams: 1 Ribeiro_MariaCeciliaEnes_D.pdf: 17038739 bytes, checksum: 54c8350faac4b14e773283e6e871aa78 (MD5) Previous issue date: 2015 / Resumo: O objetivo geral deste trabalho foi avaliar o efeito de diferentes matrizes na adesão e formação de biofilme em aço inoxidável por Bacillus cereus, bem como avaliar a eficiência dos procedimentos de higienização no controle de biofilmes de esporos desse micro-organismo. Nas duas primeiras etapas, avaliou-se a capacidade de adesão e formação de biofilme por B. cereus em aço inoxidável, com e sem prévio condicionamento da superfície, utilizando-se água, leite UHT desnatado e integral como matrizes e quatro diferentes tipos de inóculos, pool de células vegetativas de B. cereus isolados da indústria láctea, pool de esporos de B. cereus isolados da indústria láctea, células vegetativas da cepa de B. cereus ATCC 14579 e esporos da cepa de B. cereus ATCC 14579. Na terceira etapa do trabalho avaliou-se a influência da matriz condicionante (água e leite UHT integral), do meio de inoculação do pool de esporos de B. cereus (água e leite UHT integral) e do tempo de exposição (5 min (0,08h), 10, 24, 48 e 72 horas) sobre a adesão e formação de biofilme por B. cereus em aço inoxidável. Na quarta etapa, avaliou-se a eficiência de nove procedimentos de higienização na remoção dos biofilmes formados pelo pool de esporos de B. cereus em aço inoxidável. Todos os experimentos foram repetidos três vezes e os dados estatisticamente avaliados. A hidrofobicidade e o potencial zeta das superfícies dos esporos também foram avaliados. Os resultados das duas primeiras etapas indicaram que o pool de esporos de B. cereus isolados de indústria láctea apresentou a maior capacidade de adesão e formação de biofilme em aço inoxidável quando comparado aos outros tipos de inóculos, em todas as condições avaliadas. O maior grau de adesão de esporos de B. cereus (4,93 log UFC/cm2) foi observado ao se utilizar leite integral como matriz condicionante do aço inoxidável. Entretanto, comparando-se todas as matrizes, a menor adesão (3,01 log UFC/cm2) foi observada quando o pool de esporos de B cereus foi veiculado no leite integral sem prévio condicionamento da superfície. Na terceira etapa do trabalho observou-se que a adesão e formação de biofilme pelo pool de esporos de B. cereus foi maior quando inoculados em água, independente das matrizes de condicionamento. A adesão de B. cereus aumentou 1,02 e 0,3 log UFC/cm2 ao longo do tempo de exposição, quando o pool de esporos de B. cereus foi inoculado em água e leite integral, respectivamente. O biofilme de esporos veiculados na água apresentou maior resistência aos procedimentos de higienização. A sanitização com hipoclorito de sódio foi mais eficiente na remoção dos biofilmes quando comparada ao ácido peracético. O pool de esporos de B. cereus isolados da indústria láctea foi altamente hidrofóbico e apresentou carga negativa em uma ampla faixa de pH, com ponto isoelétrico de aproximadamente 3,0. Os esporos de B. cereus isolados da indústria láctea apresentaram maior capacidade de adesão ao aço inoxidável quando comparados aos outros inóculos avaliados, o que pode estar relacionado à alta hidrofobicidade e a baixa carga de superfície dos esporos / Abstract: The aim of this study was to evaluate the effect of different matrices on the adhesion and biofilm formation by Bacillus cereus on stainless steel, and to evaluate the effectiveness of sanitation procedures for controlling biofilm from spores of this microorganism. The first two parts were carried out in order to evaluate the adhesion and biofilm formation by B. cereus on stainless steel, with and without previous conditioning of the surface, using water, skim and whole UHT milk as matrices and four different types of inocula: a pool of B. cereus vegetative cells isolated from dairy industry, a pool of B. cereus spores isolated from dairy industry, vegetative cells of B. cereus ATCC 14579, and spores of B. cereus ATCC 14579. The third part of the study evaluated the effect of the conditioning matrix (water and whole UHT milk), the inoculation medium of pool of B. cereus spores (water and whole UHT milk) and exposure time (5 min (0.08h), 10, 24, 48 and 72 hours) on the adhesion and biofilm formation by B. cereus on stainless steel. In the fourth part, the effect of nine sanitation procedures on the removal of B. cereus spores biofilm was evaluated. All experiments were repeated three times and data were statistically evaluated. Hydrophobicity and zeta potential from spore¿s surface were also evaluated. Regarding the results to the first and second parts, the pool of B. cereus spores isolated from dairy industry had the highest ability of adhesion on stainless steel when compared to the other inocula, for all tested conditions. After stainless steel surface conditioning with whole milk, B. cereus spores showed the highest adhesion (4.93 log CFU/cm2). However, lower adhesion (3.01 log CFU/cm2) was observed when B. cereus spores were delivered in whole milk as compared to the other matrices, without previous conditioning of the surface. The results of the third part indicated that the adhesion and biofilm formation by the pool of B. cereus spores was higher when they were inoculated in water, regardless of the conditioning matrix. B. cereus spores adhesion increased by 1.02 and 0.3 log CFU/cm2 over exposure time, when the pool of B. cereus spores was inoculated into water and whole milk, respectively. Biofilm of B. cereus spores inoculated in water showed the highest resistance against all tested sanitation procedures. Sodium hypochlorite was the most effective sanitizer for removing all biofilms when compared to the peracetic acid. The pool of B. cereus spores isolated from dairy industry was highly hydrophobic and showed a negative charge at a wide pH range, with an isoelectric point of about 3.0. B. cereus spores isolated from dairy industry showed the highest ability to adhere on stainless steel when compared to the other inocula, which is possibly related to its higher hydrophobicity and lower spore surface charge / Doutorado / Tecnologia de Alimentos / Doutora em Tecnologia de Alimentos

When inhaled, bioaerosols exacerbate respiratory symptoms and diseases. Mitigating the negative health impacts of bioaerosols requires a robust understanding of the temporal and spatial dynamics of bioaerosols in the atmosphere as a function of their type (e.g., bacteria, fungal spores, plant pollens) and particle size, which determines their penetration into the respiratory tract. While it is known that bioaerosol concentrations vary by location, season and meteorological conditions, major gaps remain in understanding the co-occurrence of bioaerosols with one another, their size in the atmosphere, and their mass contributions to PM. Overall, research presented in this thesis advances the current knowledge about bioaerosols (including fungal spores, pollens, and bacteria) in following ways: 1) defining background and urban levels of bioaerosol concentrations in the Midwestern US across four seasons, 2) characterizing ambient bioaerosol and co-pollutant mixtures, 3) determining the influence of meteorology on their concentrations and size distributions, and 4) estimating bioaerosol contributions to PM mass. The spatial analysis of respirable particulate matter (PM10) across urban and background sites in Iowa demonstrated that urban areas are a source of fungal glucans, bacterial endotoxins and total proteins, which gives rise to significantly enhanced bioaerosols in urban locations compared to background sites. Similar urban enhancements in calcium—a crustal element—and its correlation with endotoxins suggested that wind-blown soil is likely the origin. Seasonally, fungal spores peaked in summer with temperature, while bacterial endotoxins peaked in autumn during the row crop harvesting season. Fungal spores, bacterial endotoxins, plant and animal detritus all peaked during the growing season, such that maximum exposures to multiple bioaerosol types concurrently. Under the influence of rain chemical tracers of pollens peaked and decreased in size from coarse (2.5-10 µm) to fine particles (< 2.5 µm), likely due to the osmotic rupture of pollen grains upon wetting. While fine-sized fungal spores also increased during rain events, maximum spore levels were observed in coarse-sized particles post-rain. The comparison of spring to late summer measurements demonstrated these influences of precipitation on bioaerosols also occur during late summer, when fungal spore levels are high and ragweed is the dominant pollen source. The ability to apportion PM mass to bioaerosols was advanced through the development of chemical profiles of pollens and their integration with chemical mass balance (CMB) source apportionment modeling, for the first time. In late-April to early-May in 2013, pollens were estimated to contribute 0.2 - 38% of PM₁₀ (0.04 – 0.8 µg m⁻³) while fungal spores contributed 0.7 – 17% of PM₁₀ (0.1 – 1.5 µg m⁻³). Collectively, this thesis provides insight into spatial, seasonal and daily variations of bioaerosols, and shows elevated outdoor exposures to bioaerosols among urban populations, with maximum levels occurring during growing seasons, periods of high temperature, and during/immediately following rainfall.

A polypodiaceous fern, Drynaria callispora sp. nov., is described from the upper Pliocene Sanying Formation in western Yunnan Province, southwestern China. This species with well-preserved pinnae and in situ spores is the first convincing Drynaria fossil record. Detailed morphological investigation reveals that D. callispora is characterized by 1) pinnatifid fronds with entire-margined pinnae having straight or zigzag secondary veins; 2) finer venation showing void quadrangular areoles, but occasionally with one unbranched veinlet; 3) one row of circular sori on each side of the strong primary vein; and 4) in situ spores with verrucate exospores elliptical in polar view and bean-shaped in equatorial view. A morphological comparison shows that D. callispora is significantly different from all the fossil species previously identified as drynarioids. A phylogenetic analysis of D. callispora supports that the fossil is closely related to D. sinica Diels and D. mollis Bedd., two extant species distributing in the Himalayas. The discovery of the new fern indicates that the genus Drynaria became diversified in its modern distribution region no later than the late Pliocene and had retained a similar ecology to that of many modern drynarioid ferns ever since.