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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.
121

Inclusão da palma forrageira (Nopalea cochenillifera (L.) Salm-Dyck) em dietas de ovinos em crescimento

BEZERRA, Sharleny Braz Lobato 20 July 2015 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2017-05-18T12:30:06Z No. of bitstreams: 1 Sharleny Braz Lobato Bezerra.pdf: 1277903 bytes, checksum: f2342c66baa50e5babac2016f3faa55c (MD5) / Made available in DSpace on 2017-05-18T12:30:06Z (GMT). No. of bitstreams: 1 Sharleny Braz Lobato Bezerra.pdf: 1277903 bytes, checksum: f2342c66baa50e5babac2016f3faa55c (MD5) Previous issue date: 2015-07-20 / Evaluate the effect of inclusion of cactus pear (Nopalea cochenillifera) on intake and digestibility of nutrients, growth performance, feeding behavior, carcass characteristics, tissue composition of leg and quality of meat of sheep in growth. Was experiment conducted on sector goat and sheep Department of Animal Science of Universidade Federal Rural de Pernambuco, thirty-two sheep male non castrated they were confined for 56 days. The cactus pear it was included in the experimental diets at levels of 0; 25; 50; 75% based on dry matter. There was quadratic effect for intake of dry matter (DM), organic matter, crude protein, ether extract, total carbohydrates and total digestible nutrients. The intake of non-fibrous carbohydrates increased and voluntary intake of water decreased with increased levels of cactus pear in the diet. The digestibility of DM presented a quadratic behavior. Regarding the feeding behavior of the animals time expended eating, ruminating and chewing were reduced and the time in idleness presented increasing linear behavior. For the variables average daily gain and feed conversion behavior was quadratic. Body weight slaughter, empty body weight, weight of the hot and cold carcass were influenced in a quadratic way by the inclusion of girl cactus in the diet. The hot and cold carcass yield increased linearly and the biological yield was not influenced by the inclusion of cactus in diets. The absolute weights of commercial cuts presented quadratic behavior. The inclusion of forage cactus in diets of lambs affected the weight and yield of "buchada" showing a quadratic effect. yield of tissue components of the leg, bones, fat and other tissues showed quadratic behavior and the yield muscles was not affected. The relations muscle:bone, muscle:fat quadratic behavior. The parameters evaluated in the meat luminosity (L*), intensity red color (a*), pH, shear force; water holding capacity and concentrations moisture, ash and protein were not affected by the inclusion of forage cactus in diets. The concentration ether extract increased linearly with the presence of forage cactus in the diet. / Este estudo foi realizado com o objetivo de avaliar o efeito da inclusão de palma miúda (Nopalea cochenillifera) sobre consumo e digestibilidade dos nutrientes, desempenho produtivo, comportamento ingestivo, características de carcaça e qualidade da carne de ovinos em crescimento. O experimento foi realizado no setor de caprinos e ovinos no Departamento de Zootecnia da Universidade Federal Rural de Pernambuco. Foram utilizados trinta e dois ovinos machos inteiros confinados durante 56 dias. A palma forrageira foi incluída nas dietas experimentais nos níveis de 0; 25; 50 e 75% com base na matéria seca. Verificou-se efeito quadrático para os consumos de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, carboidratos totais e nutrientes digestíveis totais. O consumo de carboidratos não fibrosos aumentou e o consumo voluntário de água diminuiu linearmente com a inclusão da palma. Em relação ao comportamento ingestivo dos animais, os tempos despendidos com alimentação, ruminação e mastigação foram reduzidos e o tempo em ócio apresentou comportamento linear crescente. Para as variáveis ganho de peso diário e conversão alimentar o comportamento foi quadrático. Os pesos ao abate, do corpo vazio, da carcaça quente e fria foram influenciados de maneira quadrática pela inclusão de palma miúda na dieta. Os rendimentos de carcaça quente e fria aumentaram linearmente e o rendimento biológico não foi influenciado pela inclusão de palma nas dietas. Os pesos absolutos dos cortes comerciais apresentaram comportamento quadrático; para os rendimentos apenas o corte lombo foi influenciado de forma quadrática. A inclusão de palma forrageira nas dietas de cordeiros influenciou o peso e rendimento da “buchada” que apresentaram efeito quadrático. O peso total em gramas dos músculos, ossos e gordura das pernas apresentaram comportamento quadrático. Os rendimentos dos componentes tissulares da perna, ossos, gordura e outros tecidos estes apresentaram comportamento quadrático e o rendimento de músculos não foi influenciado. Para as relações músculo:osso e músculo:gordura foi observado comportamento quadrático. Os parâmetros avaliados na carne: luminosidade (L*), intensidade da cor vermelha (a*), força de cisalhamento, capacidade de retenção de água e os teores de umidade, cinzas e proteina não foram influenciados pela inclusão de palma forrageira nas dietas; já o teor de extrato etéreo aumentou linearmente com a presença da palma forrageira nas dietas.
122

Vacas leiteiras mestiças a pasto alimentadas com diferentes suplementos no período de transição seca-águas / Crossbred dairy cows on pasture fed with different supplements on dry-water transition period

MELO, Wellington Samay de 27 February 2009 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2017-05-18T15:05:36Z No. of bitstreams: 1 Wellington Samay de Melo.pdf: 950858 bytes, checksum: 66714039b99a8f1b113f9673e24c020c (MD5) / Made available in DSpace on 2017-05-18T15:05:36Z (GMT). No. of bitstreams: 1 Wellington Samay de Melo.pdf: 950858 bytes, checksum: 66714039b99a8f1b113f9673e24c020c (MD5) Previous issue date: 2009-02-27 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This study evaluated the intake and apparent digestibility of nutrients; production and chemical composition of milk; the additional cost of the supplements; microbial synthesis of nitrogen and rude protein, and their efficiencies; plasma levels of glucose and urea; and excretions of urea in crossbred dairy cows on pasture during the dry-water transition. It was used eight cows (Gyr/Holstein/Brown Swiss) without defined genetic composition, average production of 15 kg/day and average live weight of 500 kg; distributed in two latin squares. The experimental period lasted 60 days (four sub-periods of 15 days). The following treatments were offered: corn silage + concentrate; forage cactus + concentrate, corn silage + soybean meal, and forage cactus + soybean meal. The concentrate was elaborated with 27.75% of rude protein. The pasture area used was 53 ha, with Brachiaria decumbens sp.Predomination. The supplements promote addictive effect on pasture nutrients when they contained corn silage andsubstitutive effect when they contained forage cactus. The supplements containing forage cactus promotes smaller intake of neutral detergent fiber and larger of non-fiber carbohydrate. The apparent digestibility of the neutral detergent fiber and non-fiber carbohydrate differ from the use of forage cactus or corn silage. The use of the supplements containing concentrate elevates the milk production up to 17 kg/day in the drought-waters transition period. The supplements can be used without any damage to milk composition. Economical results suggest flexibilization of the supplements. The use of the supplements balances glucose and urea plasmatic levels, as well as the ureaexcretion in urine and milk. There was similarity in the supplements nitrogen metabolism, consequently, nitrogen and of rude protein microbial synthesis they were similar. The efficiency of synthesis of microbial rude protein in cows receiving supplements on grazing in the drought-waters transition period shows an average of 146,20 g MicRP/Kg TDN. / Objetivou-se avaliar o consumo e a digestibilidade aparente dos nutrientes; produção e composição química do leite; economicidade das dietas suplementares; excreções de bases purinas, as sínteses microbianas de nitrogênio e proteína bruta, e suas eficiências; os níveis plasmáticos de glicose e uréia; assim como as excreções de uréia de vacas leiteiras mestiças suplementadas a pasto no período de transição seca-águas. Utilizaram-se oito vacas mestiças tricoss (Gir/Holandês/Pardo Suíço) sem composição genética definida, produção média de 15 kg/dia e peso vivo médio de 500 kg; distribuídas em dois quadrados latinos. O período experimental durou 60 dias (quatro sub-períodos de 15 dias). Os seguintes suplementos foram ofertados: silagem de milho + concentrado; palma + concentrado; silagem de milho + farelo de soja; e = palma + farelo de soja. O concentrado foi elaborado com teor de 27,75% de proteína bruta. A área da pastagem utilizada foi de 53 ha, com predominância de capim Brachiaria decumbens sp. Os suplementos promovem efeito aditivo aos nutrientes do pasto quando continham silagem de milho e efeito substitutivo quando continham palma forrageira. Os suplementos contendo palma forrageira promovem menores consumos de fibra em detergente neutro e maiores de carboidratos não-fibrosos. As digestibilidades aparentes de fibra em detergente neutro e carboidratos não-fibrosos diferem quando da utilização de palma forrageira ou silagem de milho. O uso dos suplementos contendo concentrado eleva a produção de leite acima de 17 kg/dia no período de transição seca-águas. Os suplementos testados podem ser seguramente utilizados sem qualquerprejuízo à composição do leite. Os resultados econômicos são sugestivos à flexibilização do uso dos suplementos. Os suplementos utilizados equilibram os níveis plasmáticos de glicose e uréia, assim como a excreção de uréia na urina e no leite. A semelhança nas excreções de bases purinas pelos animais proporciona sínteses de nitrogênio e de proteína bruta microbiana semelhantes. A eficiência de síntese de proteína bruta microbiana de vacas suplementadas a pasto no período de transição seca-águas apresenta média geral de 146,20 g PBMic/Kg NDT.
123

Sclerocactus wrightiae (Cactaceace): An Evaluation of the Impacts Associated with Cattle Grazing and the Use of Remote Sensing to Assess Cactus Detectability

Bates, Thomas Hathaway 20 April 2020 (has links)
The Wright fishhook cactus (Sclerocactus wrightiae L.D. Benson) is an endangered cactus species endemic to south-central Utah. Since its listing in 1979 by the U.S. Fish and Wildife Service, the potential impacts of soil disturbance by cattle have become a central focus of management policies and monitoring efforts. However, little to no empirical data has been collected to substantiate the hypothesis that soil disturbance by cattle has direct or indirect negative effects on Wright fishhook cactus growth or reproduction. Over the years, the Bureau of Land Mangement (BLM) and Capitol Reef National Park (CRNP) have invested significant resources documenting cactus populations including several attributes of individual cacti: GPS location, diameter, number of flowers, fruits, or buds, number of stems, and the presence or absence of a cow track within 15 cm of the cactus. While these efforts have been commendable, due to the defining phenological characteristics of this species (flower and filament color) and its short flowering period (April-May) it remains difficult to study and much basic biological information including a range wide population estimate and defined critical habitat remain unknown. Our research had two primary objectives, 1) evalutate the effects of soil disturbance by cattle on reproduction and diameter of the Wright fishhook cactus (Chapters 1 and 2), and 2) explore the use of drones and GIS to define critical habitat and obtain an accurate range wide population estimate (Chapters 3 and 4). In Chapter 1, we analyzed cactus attribute data collected by the BLM at 30 macro-plots representing different levels of soil related cattle disturbance (high, moderate, and low) from 2011-2017. We found no significant association between level of cattle disturbance and flower density or cactus diameter. We did find a significant negative association between flower frequency and increased disturbance. In Chapter 2, we conducted an experimental study where tracks were simulated within 15 cm of cacti at various levels (Ctrl, 1-Track, 2-Track, 4-Tracks, and 4-Tracks Doubled). No significant association was observed between the number of tracks and response in diameter, flower production, fruit production, or seed set. In Chapter 3, we conducted drone flights over 14 macro-plots at three different altitudes above ground level (10 m, 15 m, and 20 m) and found that while the 10 m flights provided the best remotely sensed survey results, drones are not a suitable replacement for ground censuses. In Chapter 4, we used Resource Selection Function to define critical habitat for the Wright fishhook cactus. Our modeling suggests that geology, elevation, and slope are significant factors in defining cactus habitat. Based on the results of our research we conclude that soil disturbance by cattle may not have a significant influence on Wright fishhook cactus populations or dynamics, and that accurate range wide population estimates may be best obtained through ground surveys within the predicted critical habitat.
124

Sclerocactus wrightiae (Cactaceace): An Evaluation of the Impacts Associated with Cattle Grazing and the Use of Remote Sensing to Assess Cactus Detectability

Bates, Thomas Hathaway 20 April 2020 (has links)
The Wright fishhook cactus (Sclerocactus wrightiae L.D. Benson) is an endangered cactus species endemic to south-central Utah. Since its listing in 1979 by the U.S. Fish and Wildife Service, the potential impacts of soil disturbance by cattle have become a central focus of management policies and monitoring efforts. However, little to no empirical data has been collected to substantiate the hypothesis that soil disturbance by cattle has direct or indirect negative effects on Wright fishhook cactus growth or reproduction. Over the years, the Bureau of Land Mangement (BLM) and Capitol Reef National Park (CRNP) have invested significant resources documenting cactus populations including several attributes of individual cacti: GPS location, diameter, number of flowers, fruits, or buds, number of stems, and the presence or absence of a cow track within 15 cm of the cactus. While these efforts have been commendable, due to the defining phenological characteristics of this species (flower and filament color) and its short flowering period (April-May) it remains difficult to study and much basic biological information including a range wide population estimate and defined critical habitat remain unknown. Our research had two primary objectives, 1) evalutate the effects of soil disturbance by cattle on reproduction and diameter of the Wright fishhook cactus (Chapters 1 and 2), and 2) explore the use of drones and GIS to define critical habitat and obtain an accurate range wide population estimate (Chapters 3 and 4). In Chapter 1, we analyzed cactus attribute data collected by the BLM at 30 macro-plots representing different levels of soil related cattle disturbance (high, moderate, and low) from 2011-2017. We found no significant association between level of cattle disturbance and flower density or cactus diameter. We did find a significant negative association between flower frequency and increased disturbance. In Chapter 2, we conducted an experimental study where tracks were simulated within 15 cm of cacti at various levels (Ctrl, 1-Track, 2-Track, 4-Tracks, and 4-Tracks Doubled). No significant association was observed between the number of tracks and response in diameter, flower production, fruit production, or seed set. In Chapter 3, we conducted drone flights over 14 macro-plots at three different altitudes above ground level (10 m, 15 m, and 20 m) and found that while the 10 m flights provided the best remotely sensed survey results, drones are not a suitable replacement for ground censuses. In Chapter 4, we used Resource Selection Function to define critical habitat for the Wright fishhook cactus. Our modeling suggests that geology, elevation, and slope are significant factors in defining cactus habitat. Based on the results of our research we conclude that soil disturbance by cattle may not have a significant influence on Wright fishhook cactus populations or dynamics, and that accurate range wide population estimates may be best obtained through ground surveys within the predicted critical habitat.
125

Effect of spineless cactus ( opuntia ficus-indica) meal inclusion level on voluntary feed intake and milk production of holstein cows

Serakwane, Moelelwa Rosemary January 2019 (has links)
Thesis ( (M.Sc. Agriculture (Animal Production)) -- University of Limpopo, 2019 / A lack of energy and water in livestock production limit the performance of the animal. Therefore, the objective of this study was to determine the effect of spineless cactus as a source of energy and water on feed intake, feed digestibility and milk production of Holstein cows. Cactus serves as fresh forage or stored as silage for later feeding in livestock. However, there is limited information about cactus nutrients, their proportions in different species and the variability of these proportions with season. A total of four multiparous lactating Holstein cows with an average of 650 ± 80kg live weight were used and assigned to four dietary treatments with four replicates. Each animal was used four times. A cross-over design was used. The four dietary treatments were 0%, 4%, 8% and 12% of spineless cactus meal inclusion levels. The study period was 21 days of adaptation period and 6 days of collection period. Higher digestibility and energy supply (P<0.05) were observed with spineless forage diets compared to the control diet. Inclusion of spineless in the diets improved (P<0.05) diet intake and milk production in Holstein cows. However, an improved performance in milk production was observed with spineless cactus meal inclusion levels of 4%, 8% and 12%. Amongst the diets, 0% inclusion level had lower dry matter intake of 22.7kg (P<0.05) compared to those which had spineless cactus meal. High dry matter intake resulted in higher (P<0.05) milk production of 22.7, 24.7, 23.4 and 23.8 litres for 0, 4, 8 and 12% spineless cactus meal inclusion levels, respectively. However, cows on 4% inclusion level had higher milk yield than the other diets. Milk quality (butter fat, protein, lactose, somatic cell count and milk nitrogen urea) of Holstein cows was not (P>0.05) affected by the level of spineless cactus meal inclusion in the diet. Dry matter intake, neutral detergent fibre intake, acid detergent fibre intake and metabolisble energy intake of the cows were optimized at different spineless cactus meal inclusion levels of 19.427% (r2 = 0.992), 16.375% (r2 = 0.974), 14.0% (r2 = 0.984) and 22.909% (r2 = 0.994), respectively. Spineless cactus meal inclusion had no effect (P>0.05) on ADF intake and crude protein intake. Apparent digestibility values (0.73, 0.76 and 0.76) were not significantly different at 4%, 8% and 12% of spineless cactus meal inclusion levels, respectively. v It is concluded that spineless cactus meal inclusion level in the diet affected (P<0.05) diet intake and milk production of the Holstein cows. However, these variables were optimized at different spineless cactus meal inclusion levels. It could be recommended that spineless cactus can fit perfectly in livestock rations with attention given to their low crude protein content. These opuntia species can be fed to livestock mainly cattle and sheep during any season but are needed the most during drought as supplements when forages are scarce or expensive to feed. It is, therefore, concluded that 8% of spineless cactus inclusion level can be used to maintain productivity of the animals. / National Research Foundation (NRF)
126

El Cactus San Pedro : su función y significado en Chavín de Huántar y la tradición religiosa de los Andes Centrales

Feldman Gracia, Leonardo January 2006 (has links)
No description available.
127

Cactus Hill, Rubis-Pearsall and Blueberry Hill : one is an accident; two is a coincidence; three is a pattern : predicting "old dirt" in the Nottoway river valley of Southeastern Virginia, USA

Johnson, Michael Farley January 2012 (has links)
This thesis covers more than thirty years of the author's research into the Paleoamerican period of the Middle Atlantic Region of North America, including the last 19+ years of focused work on the Cactus Hill site (44SX202) and replication of the Paleoamerican occupation discovered there. Using a landform and geology based predictive model derived from the Paleoamerican occupation at Cactus Hill, the author directed preliminary archaeological testing in three other areas of the same Nottoway River Valley, where Cactus Hill is located. These areas were the Barr site, located 11 miles (18 km.) downriver from Cactus Hill; the Chub Sandhill Natural Resource Conservation Area, located 19 miles (30 km.) downriver from Cactus Hill; and the Blueberry Hill site (44SX327), located approximately 1,000 feet (300 meters) east of Cactus Hill. The latter two produced OSL dated, pre-Younger-Dryas landforms, as predicted. The Rubis-Pearsall site (44SX360), located in the Chub Sandhill preserve also produced a buried Paleoamerican, Clovis age cultural level confirming the model. In addition to the OSL dates, Blueberry Hill also produced a distinct and apparently discrete activity surface with a possible pre-Clovis age Cactus Hill point at the same depth as the Paleoamerican levels at Cactus Hill and Rubis-Pearsall.
128

Functional Anatomy and Development of Cactus Ramifications

Schwager, Hannes 12 November 2015 (has links) (PDF)
Cacti (Cactaceae) represent a family of highly specialized angiosperm plants with a native range of distribution restricted to the American continents. Columnar cacti of the sub-family Cactoideae evolved in adaptation to their arid or semi-arid habitats characteristics that distinguish them from most other dicot plants, e.g. the stem succulence with a strongly vascularized storage parenchyma and the presence of the spine wearing areoles. Although cacti have been in cultivation since the discovery of America, some studies even suggest the agricultural use in pre-colombian times, and many scientific investigations were carried out on the functional morphology and anatomy with regard to biomechanical adaptations of the found structures, no research focused on the branch-stem attachment. The most conspicuous features of such a ramification are the pronounced constrictions at the branch-stem junctions that are also present in the lignified vascular structures within the succulent cortex. Based on Finite Element Analyses of ramification models it could be demonstrated that these indentations in the region of high flexural and torsional stresses are not regions of structural weakness, e.g. allowing vegetative propagation. On the contrary, they can be regarded as anatomical adaptations to increase the stability by fine-tuning the stress state and stress directions in the junction along prevalent fiber directions. The development of the woody support structure within the succulent cortex of the parental shoot can be traced back to the leaf and bud traces of the dormant axillary buds. Surprisingly, these initials also develop into another woody structure supporting the flowers of the cacti. As these two support structures differ significantly in their macroscopic and microscopic anatomy and as they develop from the same initial state as leaf/bud traces, another objective of this work was to analyze the secondary growth of the two structures with traditional botanic investigation methods. The results of these investigations reveal a wood dimorphism consisting of an early parenchymatous phase followed later by fibrous wood in both kind of support structure. In vegetative branches, the woody support structures have the typical ringlike arrangement as found in the stele of the parental shoot, whereas the flower support structures have a reticular arrangement of interconnected woody strands. This fundamentally different anatomy of the support structures results from the formation of an interfascicular cambium between the leaf/bud traces when a vegetative branch forms or its absence in the case of a flower. After shedding light on the functional morphology and anatomy of the cactus ramification and their development the question arises if the found load adaptation strategies may serve to improve technical fiber composite structures analogue to the design recommendation developed from the biomechanical analyses of tree ramifications. Such a biomimetic transfer from the cactus ramification as biological role model to a technical implementation and the adaptation of the fine-tuned geometric shape and arrangement of lignified strengthening tissues might contribute to the development of alternative concepts for branched fiber-reinforced composite structures within a limited design space.
129

Biological control of Pereskia aculeata Miller (Cactaceae)

Paterson, Iain Douglas January 2011 (has links)
Pereskia aculeata Miller (Cactaceae) is an environmental weed that is damaging to natural ecosystems in South Africa. The plant is native to Central and South America and was first recorded in South Africa in a botanical garden in 1858. In this thesis, research into the biological control of P. aculeata was conducted with the intention of improving the control of the weed. A pre-release study of the relationship between P. aculeata density and native plant biodiversity indicated that P. aculeata has a negative impact on native biodiversity. The native plant biodiversity associated with different P. aculeata densities was used to determine threshold values and goals for the control of the weed. A threshold value of 50% P. aculeata density was calculated, indicating that P. aculeata density must be maintained below 50% in order to conserve native plant biodiversity. The ultimate goal of the control programme should be to maintain P. aculeata densities below 30%. At these densities there was no significant difference in native plant biodiversity from if the weed were absent from the ecosystem. The biological control agent, Phenrica guérini Bechyne (Chrysomelidae), has been released in South Africa but the potential of the agent to impact P. aculeata is not known and no post release evaluation has been conducted. Impact assessment studies indicate that P. guérini does not impact P. aculeata, even at high densities, but the results of greenhouse experiments should be interpreted with caution because of problems with extrapolation into the field. Although observations in the field suggest that P. guérini has reduced P. aculeata densities at one site, it is clear that new biological control agents are needed to reduce the weed to acceptable levels. Identifying the origin of the South African P. aculeata population was believed to be important to the biological control programme due to the disjunct native distribution and intraspecific variation of the species. Natural enemies associated with plant genotypes in different parts of the native distribution may have developed specialised relationships with certain intraspecific variants of the plant, resulting in differences in agent efficacy on certain host plant genotypes. A molecular study indicated that the closest relatives to the South African weed population found in the native distribution were in Rio de Janeiro Province, Brazil. A bioassay experiment in which fitness related traits of the biological control agent, P. guérini, were measured on various P. aculeata genotypes was conducted to determine the importance of host plant intraspecific variation. There was little variation in fitness traits between genotypes and no evidence of intraspecific host plant specialization. Although intraspecific variation had no effect on agent efficacy in the case of P. guérini, it is possible that other natural enemies may be more specialized. Genotype matching is expected to be more important when natural enemies likely to be specialised to individual genotypes are considered for biological control. Potential biological control agents were prioritized from data collected on surveys in the native distribution. The most promising of these, based on the presence of feeding, incidence, predicted host range, climatic matching, genotype matching and mode of damage, are two species of Curculionidae, the current biological control agent P. guérini and the stem boring moth, Maracayia chiorisalis Walker (Crambidae). The two curculionid species and M. chlorisalis should be considered priorities for host specificity studies. Releases of P. guérini and any new biological control agents should be made at sites where the pre-release study was conducted so that post-release evaluation data can be compared with the pre-release data and the impact of biological control can be evaluated. Retrospective analyses of biological control programmes provide important ways of improving aspects of biological control programmes, such as methods of agent selection. The evaluation of success in biological control programmes is essential for retrospective analyses because factors that have lead to successes or failures can be analysed. Retrospective analyses of biological control programmes, such as this thesis, may improve weed management, thereby contributing to the conservation of natural resources.
130

Palma forrageira (Opuntia ficus indica e Nopalea cochenillifera) como mat?ria-prima para produ??o de etanol celul?sico e enzimas celulol?ticas

Souza Filho, Pedro Ferreira de 09 May 2014 (has links)
Made available in DSpace on 2014-12-17T15:01:34Z (GMT). No. of bitstreams: 1 PedroFSF_DISSERT.pdf: 2707475 bytes, checksum: 2a6ef9226a3d6d607615f74305bb9e07 (MD5) Previous issue date: 2014-05-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The need for new sources of energy and the concern about the environment have pushed the search for renewable energy sources such as ethanol. The use of lignocellulosic biomass as substrate appears as an important alternative because of the abundance of this raw material and for it does not compete with food production. However, the process still meets difficulties of implementation, including the cost for production of enzymes that degrade cellulose to fermentable sugars. The aim of this study was to evaluate the behavior of the species of cactus pear Opuntia ficus indica and Nopalea cochenillifera, commonly found in northeastern Brazil, as raw materials for the production of: 1) cellulosic ethanol by simultaneous saccharification and fermentation (SSF) process, using two different strains of Saccharomyces cerevisiae (PE-2 and LNF CA-11), and 2) cellulolytic enzymes by semi-solid state fermentation (SSSF) using the filamentous fungus Penicillium chrysogenum. Before alcoholic fermentation process, the material was conditioned and pretreated by three different strategies: alkaline hydrogen peroxide, alkaline using NaOH and acid using H2SO4 followed by alkaline delignification with NaOH. Analysis of composition, crystallinity and enzymatic digestibility were carried out with the material before and after pretreatment. In addition, scanning electron microscopy images were used to compare qualitatively the material and observe the effects of pretreatments. An experimental design 2? with triplicate at the central point was used to evaluate the influence of temperature (30, 40 and 45 ?C) and the initial charge of substrate (3, 4 and 5% cellulose) in the SSF process using the material obtained through the best condition and testing both strains of S. cerevisiae, one of them flocculent (LNF CA-11). For cellulase production, the filamentous fungus P. chrysogenum was tested with N. cochenillifera in the raw condition (without pretreatment) and pretrated hydrothermically, varying the pH of the fermentative medium (3, 5 and 7). The characterization of cactus pear resulted in 31.55% cellulose, 17.12% hemicellulose and 10.25% lignin for N. cochenillifera and 34.86% cellulose, 19.97% hemicellulose and 15.72% lignin for O. ficus indica. It has also been determined, to N. cochenillifera and O. ficus indica, the content of pectin (5.44% and 5.55% of calcium pectate, respectively), extractives (26.90% and 9.69%, respectively) and ashes (5.40% and 5.95%). Pretreatment using alkaline hydrogen peroxide resulted in the best cellulose recovery results (86.16% for N. cochenillifera and 93.59% for O. ficus indica) and delignification (48.79% and 23.84% for N. cochenillifera and O. ficus indica, respectively). This pretreatment was also the only one which did not increase the crystallinity index of the samples, in the case of O. ficus indica. However, when analyzing the enzymatic digestibility of cellulose, alkali pretreatment was the one which showed the best yields and therefore it was chosen for the tests in SSF. The experiments showed higher yield of conversion of cellulose to ethanol by PE-2 strain using the pretreated N. cochenillifera (93.81%) at 40 ?C using 4% initial charge of cellulose. N. cochenillifera gave better yields than O. ficus indica and PE-2 strain showed better performance than CA-11. N. cochenillifera proved to be a substrate that can be used in the SSSF for enzymes production, reaching values of 1.00 U/g of CMCase and 0.85 FPU/g. The pretreatment was not effective to increase the enzymatic activity values / A necessidade de novas fontes de energia e a preocupa??o com o meio-ambiente t?m impulsionado a pesquisa por fontes renov?veis de energia, como o etanol. O uso de biomassa lignocelul?sica como substrato aparece como uma importante alternativa devido ? abund?ncia desta mat?ria-prima e por n?o concorrer com a produ??o de alimentos. Entretanto, o processo ainda encontra dificuldades de implementa??o, entre elas o custo para produ??o das enzimas que degradam a celulose em a??cares fermentesc?veis. O objetivo deste trabalho foi avaliar o comportamento das esp?cies de palma forrageira Opuntia ficus indica (gigante) e Nopalea cochenillifera (mi?da), comumente encontradas na regi?o Nordeste do Brasil, como mat?rias-primas para produ??o de: 1) etanol celul?sico pelo processo de sacarifica??o e fermenta??o simult?neas (SFS) usando duas cepas diferentes de Saccharomyces cerevisiae (PE-2 e LNF CA-11) e 2) enzimas celulol?ticas atrav?s da fermenta??o em estado semiss?lido (FES) usando o fungo filamentoso Penicillium chrysogenum. Antes do processo de fermenta??o alco?lica, o material foi condicionado e pr?-tratado por tr?s diferentes estrat?gias: per?xido de hidrog?nio alcalino, alcalino usando NaOH e ?cido usando H2SO4 seguido de deslignifica??o alcalina com NaOH. An?lises de composi??o, cristalinidade e digestibilidade enzim?tica foram feitas com o material antes e depois do pr?-tratamento. Adicionalmente, imagens de microscopia eletr?nica de varredura foram usadas para comparar qualitativamente o material e observar os efeitos dos pr?-tratamentos. Um planejamento fatorial 2? com triplicata no ponto central foi utilizado para avaliar a influ?ncia da temperatura (30, 40 e 45 ?C) e da carga inicial de substrato (3, 4 e 5% de celulose) no processo SFS, usando o material obtido nas melhores condi??es de pr?-tratamento e testando duas cepas de S. cerevisiae, sendo uma delas floculante (LNF CA-11). Para a produ??o de celulase, o fungo filamentoso P. chrysogenum foi testado com a esp?cie de palma N. cochenillifera no estado in-natura (sem pr?-tratamento) e submetida a um pr?-tratamento hidrot?rmico, variando-se o pH do meio fermentativo (3, 5 e 7). A caracteriza??o das palmas forrageiras resultou em 31,55% de celulose, 17,12% de hemicelulose e 10,25% de lignina para a esp?cie N. cochenillifera e 34,86% de celulose, 19,97% de hemicelulose e 15,72% de lignina para a esp?cie O. ficus indica. Analisou-se ainda, para as palmas mi?da e gigante, o teor de pectina (5,44% e 5,55% de pectato de c?lcio, respectivamente), extrativos (26,90% e 9,69%, respectivamente) e cinzas (5,40% e 5,95%). O pr?-tratamento usando per?xido de hidrog?nio alcalino apresentou os melhores resultados de recupera??o de celulose (86,16% para a palma mi?da e 93,59% para a palma gigante) e de deslignifica??o (48,79% e 23,84% para as palmas mi?da e gigante, respectivamente). Este pr?-tratamento foi tamb?m o ?nico a n?o elevar o ?ndice de cristalinidade das amostras, no caso da palma gigante. Entretanto, quando analisada a digestibilidade enzim?tica da celulose, o pr?-tratamento alcalino foi o que proporcionou os melhores rendimentos e, portanto, este foi o escolhido para os testes de SFS. Os experimentos demonstraram maior rendimento da convers?o de celulose em etanol pela cepa PE-2 usando a palma mi?da pr?-tratada (93,81%) a 40 ?C e usando 4% de carga inicial de celulose. A palma mi?da demonstrou melhores rendimentos que a gigante e a cepa PE-2 resultou melhor desempenho que a CA-11. A palma mi?da se mostrou um substrato poss?vel de ser usado na FES para produ??o de enzimas, alcan?ando valores de 1,00 U/g de CMCase e 0,85 FPU/g. O pr?-tratamento n?o se mostrou eficaz para aumentar os valores de atividade enzim?tica

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