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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.
1

Variación morfológica de Opuntia (Cactaceae) y su relación con la domesticación en la altiplanicie meridional de México /

Reyes Agüero, Juan Antonio. January 2005 (has links)
Thesis (doctoral) -- Universidad Nacional Autónoma de México, 2005. / ''Posgrado en Ciencias Biológicas.'' Includes reprints of published articles in English and Spanish. Includes bibliographical references. Also available online.
2

Variación morfológica de Opuntia (Cactaceae) y su relación con la domesticación en la altiplanicie meridional de México /

Reyes Agüero, Juan Antonio. January 2005 (has links)
Thesis (doctoral) -- Universidad Nacional Autónoma de México, 2005. / Includes reprints of published articles in English and Spanish. Includes bibliographical references. Also available online.
3

The ecology and morphological variation of Opuntia (Cactaceae) species in the mid-south, United States /

Majure, Lucas Charles. January 2007 (has links) (PDF)
Thesis (M.S.)--Mississippi State University, 2007. / Includes bibliographical references. Also available via the Worl Wide Web: http://www.msstate.edu/courses/ge14/students/Majure_Thesis.pdf
4

AcÃmulo de fitomassa e composiÃÃo quÃmico-bromatolÃgica da palma forrageira sob adubaÃÃo mineral em sequeiro / Biomass formation and chemical composition of cactus pear under mineral fertilization under rainfed conditions

Maria Janiele Ferreira Coutinho 21 February 2014 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Objetivou-se avaliar a influÃncia da adubaÃÃo NPK sobre o crescimento vegetativo, produÃÃo e composiÃÃo quÃmico-bromatolÃgica da palma forrageira (Opuntia ficus-indica Mill.). O experimento foi constituÃdo de dezesseis combinaÃÃes de doses de NPK, conforme matriz experimental Plan Puebla II, distribuÃda em delineamento inteiramente casualizado, com quatro repetiÃÃes. Foram realizadas observaÃÃes dos parÃmetros de crescimento da palma, sendo verificados os aspectos morfomÃtricos: nÃmero de cladÃdios por planta (NC), comprimento (CC), largura (LC), espessura (EC) dos cladÃdios e Ãndice de Ãrea do cladÃdio (IAC). Foram estudadas ainda a produtividade e a composiÃÃo quÃmico-bromatolÃgica da palma forrageira. A produtividade da palma foi influenciada significativamente em face da aplicaÃÃo dos diferentes nÃveis de NPK. Com exceÃÃo da largura as variÃveis morfomÃtricas (comprimento, espessura, nÃmero de cladÃdios por planta e Ãndice de Ãrea de cladÃdio) nÃo foram influenciadas significativamente. A anÃlise de variÃncia para os teores de proteÃna bruta, ao contrÃrio dos valores de matÃria seca evidenciou diferenÃa estatÃstica. Os resultados dos teores de FDA da palma forrageira para os diferentes tratamentos aumentaram ao mesmo tempo em que se elevaram os nÃveis de NPK. As quantidades de nutrientes utilizados nas adubaÃÃes promovem pequenas alteraÃÃes na produÃÃo. A adiÃÃo de NPK promove aumento no teor de proteÃna, o que resulta em melhoria na qualidade nutricional da palma forrageira. / This study aimed to evaluate the influence of NPK fertilization on vegetative growth, yield and chemical composition of cactus pear (Opuntia ficus-indica Mill.). The experiment consisted of sixteen combinations of doses of NPK as Plan Puebla II experimental matrix, distributed in a completely randomized design with four replications. Were performed Observations of the growth of the palm morphometric aspects being checked: number of cladodes per plant (NC) , length (BL) , width (CW) , thickness (CE) and cladodes of the area index of the cladodes (IAC) . Further productivity and chemical composition of cactus pear were studied . The productivity of the palm was influenced significantly based on application of different levels of NPK. Except the width morphometric variables (length, thickness, number of cladodes per plant and leaf area index of cladodes ) were not affected significantly . The analysis of variance for crude protein , unlike the dry matter values statistically different. The results of the FDA rate of cactus pear for the different treatments increased while that increased levels of NPK . The amounts of nutrients used in fertilizers promote small changes in production. The addition of NPK promotes increased protein content, which results in improved nutritional quality of the forage palm.
5

Cinética de degradación de betalaínas de pulpa de tuna púrpura (Opuntia ficus-indica) y extracto nanofiltrado antes y después de su encapsulación mediante secado por atomización

Henríquez Pastene, Barcyette Jeannette January 2014 (has links)
Memoria para optar al título de Ingeniero en Alimentos / No autorizada por el autor para ser publicada a texto completo en el Portal de Tesis Electrónicas / Las betalaínas son pigmentos coloreados que se clasifican en betacianinas (rojo- púrpura) ó betaxantinas (amarillo-anaranjado). La tuna púrpura (Opuntia ficus-indica) es una de las pocas fuentes de estos pigmentos, siendo rica en betacianinas, principalmente betanina, aceptada como colorante rojo por la Unión Europea y EEUU. Se encapsuló pulpa (P) y extracto nanofiltrado (NF) de tuna púrpura por secado por atomización, utilizando K4484 (K) (dextrina de tapioca) y Capsul (C) (almidón modificado hidrofóbicamente de maíz ceroso), como agentes encapsulantes. Se obtuvo altas eficiencias de encapsulación para las betacianinas (>99%) y betaxantinas (>98%) de los sistemas de micropartículas (P-K, P-C, NF-K y NF-C), lo cual se podría atribuir a interacciones por puentes de hidrógeno y/o electroestáticas entre las betalaínas y los polímeros. Se estudió la cinética de degradación de betanina a tres temperaturas de almacenamiento (30°C, 45°C y 60°C) para los sistemas P, NF, P-K, P-C, NF-K y NF-C. Los resultados mostraron que la degradación de betanina en los seis sistemas estudiados siguió una cinética de pseudo-primer orden (R2= 0,83-0,99), siendo la kobs significativamente menor en las micropartículas (P-K, P-C, NF-K y NF-C) respecto a los extractos (P y NF), mostrando el efecto protector de la encapsulación sobre la betanina. Se obtuvo los parámetros cinéticos y termodinámicos a partir de las ecuaciones de Arrhenius y de Eyring. Al comparar el tipo de extracto en las micropartículas, se encontró un efecto diferente entre K y C. En el sistema NF-K (3,4*10-3 días-1; 5,8*10-3 días-1) se observó una constante de degradación de betanina significativamente menor que en el sistema P-K a 45°C y 60°C (5,7*10-3 días-1; 7,1*10-3 días-1), atribuido a la ausencia de mucílagos en el extracto NF. Contrariamente, las kobs en NF-C (9,8*10-3 días-1; 15,0*10-3 días-1; 30,4*10-3 días-1) fueron significativamente mayores que en P-C (3,1*10-3 días-1; 6,4*10-3 días-1; 8,1*10-3 días-1) a 30°C, 45°C y 60°C, atribuido al mayor contenido de azúcares en el extracto NF. Estos resultados sugieren que la presencia de mucílago y azúcares en las micropartículas favorecieron la degradación de la betanina, lo que se atribuye principalmente al mecanismo de hidrólisis del enlace aldimina (N=C), siendo la higroscopicidad un factor crítico en su estabilidad. El gráfico de H≠ vs S≠ mostró una relación lineal, sugiriendo que la degradación de betanina siguió el mismo mecanismo para todos los sistemas de micropartículas estudiados / Betalains are colored pigments classified as betacyanins (red-purple) and betaxanthins (yellow- orange). The purple cactus pear (Opuntia ficus -indica) is one of the few sources of these pigments, being rich in betacyanins mainly betanin and accepted as red dye by the European Union and USA. Pulp (P) and nanofiltered extract (NF) of purple cactus pear were encapsulated by spray drying, using K4484 (tapioca dextrin) and Capsul® (hydrophobically modified waxy maize starch), as encapsulating agents. The microparticles systems (P-K, P-C, NF- K and NF-C) showed high encapsulation efficiencies for betacyanins (> 99 %) and betaxanthins (> 98 %), which could be attributed to hydrogen bond and/or electrostatic interactions between betalains and polymers. Betanin degradation kinetics was studied at three storage temperatures (30, 45 and 60 °C) for P, NF, P-K, P-C, NF-K and NF-C systems. The results showed that the betanin degradation in all the systems studied followed pseudo-first order kinetics (R2 = 0.83-0.99), being kobs significantly lower in the microparticles (P-K, P-C, NF-K and NF-C) in regard to extracts (P and NF), showing the protective effect of betanin encapsulation. The kinetic and thermodynamic parameters were calculated from the Arrhenius and Eyring equations. Different effect between K and C was observed when the type of extract in the microparticles was compared. Betanin degradation rate constant in NF-K (3.4*10-3 day -1, 5.8*10-3 day-1) was significantly lower than P-K system for both 45 and 60 °C (5.7*10-3 day -1, 7.1*10-3 day-1), attributed to the absence of mucilages in the NF extract. Contrary, the kobs for NF-C (9.8*10-3 day-1, 15.0*10-3 day -1, and 30.4*10-3 day- 1) were significantly higher than P-C ( 3.1 day-1*10-3, 6.4*10-3 day-1, 8.1*10-3 day-1) at 30, 45 and 60 °C , attributed to the higher content of sugars in the NF extract. These results suggest that the presence of mucilage and/or sugars in the microparticles increase the betanin degradation. The hydrolysis of the aldimine bond (N = C) is the mainly pathway of betanin degradation in microparticles, being hygroscopicity a critical factor. The H≠ vs S ≠ graph showed a linear relationship, suggesting that the degradation of betanin followed the same mechanism for all systems of microparticles studied
6

Root-stem transition of Opuntia engelmannii Salm-Dyck

Longnecker, William Mayne, January 1941 (has links)
Thesis (Ph. D.)--University of Chicago, 1941. / Lithoprinted. Includes bibliographical references (p. 6).
7

A PHYSIO-ECOLOGICAL STUDY OF JUMPING CHOLLA (OPUNTIA FULGIDA, ENGELM.)

Tschirley, Fred Harold, 1925- January 1963 (has links)
No description available.
8

Taxonomic relationship of Opuntia kleiniae de Candolle and Opuntia tetracantha Toumey

Fischer, Pierre C. January 1962 (has links)
No description available.
9

Root-stem transition of Opuntia engelmannii Salm-Dyck

Longnecker, William Mayne, January 1941 (has links)
Thesis (Ph. D.)--University of Chicago, 1941. / Lithoprinted. Includes bibliographical references (p. 6).
10

Interactions between cacti and cactus-feeding insects causes and consequences of variation /

Miller, Thomas Edward. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed Aug. 1, 2007). PDF text: 230 p. : ill. (some col.) UMI publication number: AAT 3255893. Includes bibliographical references. Also available in microfilm and microfiche formats.

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