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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.
21

Association between betel nut consumption and folate deficiency among pregnant women in Matlab, Bangladesh

Kader, Manzur January 2011 (has links)
Background:  Betel nut (BN) or Areca nut (AN) chewing habits on its own or with other ingredients including chewing tobacco are highly prevalent in many South East Asian countries as well as among the migrants from these countries residing around the world. The major alcaloid arecoline in betel nut has been found to carcinogenic and to be associated with a range of health risks, including negative effects on pregnancy outcomes.  It is also reportedly associated with nutritional deficiencies including lower folate status among men and women. Pregnancy imposes stress on folate stores because of increased requirements for growth of maternal tissues, the fetus and the placenta.  Folate deficiency during pregnancy is a major public health concern as it is associated with many adverse health outcomes including neural tube defects, low birth weight, preterm birth, delayed maturation of the nervous system, growth retardation and megaloblastic anemia. Aim: To evaluate the association between betel nut use and folate status among pregnant women in Matlab, Bangladesh. Design: A secondary analysis of data from the Maternal and Infant Nutrition Intervention in Matlab (MINIMat) trial.  A sub sample of pregnant women aged 14-50 years and living in the study area Matlab with available serum folate measurements (N= 730) was included in this study. Outcome variable was folate level and folate deficiency and the independent variable was betel nut consumption.  Logistic regression analysis and analyses of covariance (ANCOVA) were done. Results were adjusted for potential confounders. Results: Two-thirds (63%) of the women consumed betel nut and 17% had folate deficiency. Women who consumed betel nut combined with  chewing  tobacco were 2.57 times more likely to have folate deficiency (OR = 2.57; 95% CI = 1.23-5.36; p =0.012;) and  betel nut consumption 2-3 times/day was significantly associated with folate deficiency among users (OR = 2.51; 95% CI = 1.07–5.92; p =0.035). Mean serum folate levels were significantly lower among betel nut users as compared to non-users. Conclusion: Betel nut consumption combined with chewing tobacco is associated with lower serum folate level or folate deficiency among pregnant women in Matlab in Bangladesh. Strategies are needed for prevention and control of betel nut consumption in order to prevent adverse health outcomes. There is a need of more knowledge regarding betel nut use and other combined substances to distinguish their individual effects on folate deficiency.
22

Molecular and Pheromone Studies of Pecan Nut Casebearer, Acrobasis nuxvorella Neunzig (Lepidoptera: Pyralidae)

Hartfield, Emilie Anne 2009 December 1900 (has links)
The pecan nut casebearer, Acrobasis nuxvorella Neunzig (Lepidoptera: Pyralidae) is the most damaging insect pest of pecan, Carya illinoinensis (Wang) K. Koch (Fagales: Juglandaceae). Two sex pheromones have been identified for this species and are currently being used to assist pecan growers in the timing of insecticide applications. The discovery that there are two pheromone types produced by A. nuxvorella has led to complications in the implementation of pheromone monitoring programs. One pheromone (referred to as standard) is attractive to moths in the southern US, but not in Mexico. The other pheromone (referred to as Mexican) is attractive to moths in the southern US and in Mexico. Because most male lepidopterans respond only to a specific pheromone, it was suspected that there were two pheromone strains of A. nuxvorella, one exclusively present in the northern distribution of A. nuxvorella (US strain) and the other widely distributed from Sonora, Chihuahua, and Durango in Northern Mexico to Texas, Georgia, and Oklahoma in the US (Mexican strain). In order to confirm the existence of the two alleged pheromone strains, AFLP markers were obtained and analyzed, male response to pheromones was observed and phenological differences were assessed. Additionally, the relative abundance of each of the two pherotypes was evaluated and the population structure of this pest across its geographic distribution was determined. Results of genetic analysis show that the genetic differentiation between these insects is not explained by pheromone type. This information is further supported by a pheromone assay in which a large proportion of US collected A. nuxvorella males and Mexican collected A. nuxvorella males chose both pheromones when tested multiple times. Furthermore, no phenological differences were detected between the two pherotypes in the US, although significantly more male A. nuxvorella in the US are attracted to field-deployed pheromone traps baited with the standard pheromone than the Mexican pheromone. Finally, population genetic analyses indicate a high degree of genetic structure in A. nuxvorella across its geographic distribution, with the genetically distinct populations occurring in areas where A. nuxvorella is not native, but has been introduced.
23

Effect of material properties on the tribological behavior of screw and nut

Jou, Je-Yi 05 July 2001 (has links)
In this study, the seal bushings were designed to allow the lubricant stored in the screw and the nut system. Effect of thread clearance on the life of the screw were investigated. The screw and nut are made of S45C and HBsC3, respectively. Effects of material pairs on friction coefficient were investigated by using the pin on disk tester to simulate the friction condition between the screw and the nut. Result shows that the life of the screw increases with increasing thread clearance. The longest life for the maximum clearance can achieve 6790 cycles. Under the same surface pressure, the friction coefficients of HBsC3 on self-lubricating alloy and HBsC3 on SCM 440 are much smaller than self-lubricating alloy on self-lubricating alloy and self-lubricating alloy on SCM 440 by using nut on screw.
24

English occupation of the Pailon, Ecuador, 1860-1896 : a case study of British settlement failure in nineteenth-century Latin America

Fisher, Alan Geoffrey January 2000 (has links)
The thesis analyses the British attempt to settle and develop the Pailon region of Esmeraldas province, Ecuador, between 1860 and 1896. Set against the background of Ecuador's nineteenth-century struggle to achieve political stability and economic development in the forging of an independent nation-state, the study accounts for the Ecuadorian government's agreement in the treaties of 1854 and 1857 to cede territory for European colonisation to British bondholders in order to cancel unpaid back interest on Ecuador's portion of Gran Colombia's 'Independence' debt. Through the extensive use of settlers' first-hand accounts and of the primary documents contained in the British Foreign Office archives, a framework established from the personal experiences of the leading protagonists of four successive groups of British Pailon settlers enables the thesis to argue that the attempts to colonise and develop the Pailon not only failed through conflictive issues over sovereignty and development related to Britain's position as the world's hegemonic imperial, commercial and financial power, but also as a result of local conditions and disputes that can be broadly categorised as cultural conflicts between settlers and the native population in the frontier territory of an emerging, newly independent nineteenth-century Ecuadorian republic. In the final analysis, the thesis uses the case study to highlight the factors that conspired against successful settlement and offers the results as empirical evidence for the proposal of a more holistic 'cultural' model to explain the high incidence of failure among British colonisation attempts in nineteenth-century Latin America, as well as developing a more general six-stage model for determining the extent to which a colonisation attempt succeeds or fails.
25

Top-Working Fruit and Nut Trees by the Biederman Bark Graft Method

Kinnison, A. F. 07 1900 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
26

The development of a genetic linkage map for almond based on molecular and agronomic markers.

Gregory, Davina January 2004 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Almond, Prunus dulcis, is a tree nut crop that originated in central Asia and is now grown commercially worldwide. Within Australia there exists huge potential gain from optimisation of almond cultivars better suited to Australian conditions. This is the ultimate goal of the Australian Almond Breeding Program, which was established in 1997 at the University of Adelaide. As part of this breeding program a unique hybrid population was developed from a cross between the American self-incompatible cultivar 'Nonpareil' (NP) and European self-compatible cultivar 'Lauranne' (LA). The F₁ population derived from this cross is the focus of this study, the population consisted of 181 individuals, of which 93 were selected for use in the mapping study. Investigation of a number of DNA extraction techniques was performed in order to optimise DNA extraction quality and integrity from almond leaves for future applications in molecular work. To determine if the purported F₁ hybrids were true hybrids, derived from a cross between the cultivars NP and LA, both DNA fingerprinting with cluster analysis and S-allele identification was performed, and the majority of F₁ putative hybrids clustered between the two parents when analysed using the simple matching coefficient and UPGMA. The genetic similarity between individuals comprising the mapping population ranged from 70% to 93% while the parents were 72% similar in comparison to each other. This indicated high genetic variability available for studying heritabilities and for production of a genetic map. Analysing the S-allele complement of all the F₁ hybrids was also performed to offer a more robust method for hybrid determination, since individuals in a breeding population with aberrant S-allele inheritance can be considered non-related. The inheritance of the self-fertility gene is important in breeding programs, since the majority of almond cultivars are self-incompatible, tracking the inheritance of this allele in breeding programs is therefore highly desirable. A detailed morphological study was performed on the whole population over three growing seasons, 2001, 2002, and 2003. In 2001 tree characters such as disease prevalence, bare branches, close internodes, level of upright branches, leaf size and colour were measured. For all the seasons a number of other traits were also measured including: yield, bloom time, self-compatibility, percentage of double kernels, shell hardness, kernel weight, shape, taste, pubescence, and colour. The heritability, genetic variance, segregation and raw correlations between traits were calculated and used to establish a mode of inheritance for these traits. Rainfall and temperature maximum, minimum and monthly averages were collected and used to compare trends in the collected morphological data with these climatic data. A preliminary investigation was undertaken to determine if the cellular structure of the kernel testa epidermis was responsible for the pubescent versus smooth mouth feel of the F₁ hybrids. Light and scanning electron microscopy identified the presence of cellular protuberances arising from the epidermis as a potential cause of the pubescent mouthfeel in almonds. Bulked segregant analysis using inter-simple sequence repeat (ISSR) primers identified a potential marker linked to the pubescent trait which was converted to a sequence characterised amplified region (SCAR), which was also used to screen twelve almond cultivars for this trait. In addition to the use of BSA for the development of markers linked to traits of interest, the development of genetic linkage maps has the potential to greatly enhance current and future breeding programs by MAS. This study produced a genetic linkage map for this population, constructed using random amplified polymorphic DNA (RAPD), ISSR, and simple sequence repeats (SSR), with the mapping program Joinmap 3.0. Two parental maps were constructed, which coalesced into seven linkage groups for the female parent and eight linkage groups for the male parent, corresponding to the chromosome number of eight for almond. The marker density was 9.4 cM/marker for NP and 9.6 cM/marker for LA, covering 65% for the female and male parental maps in compalison to the highly saturated peach x almond map produced by the European Prunus Mapping Program (EPMP). Fourteen markers segregating in both parents were used to produce an integrated parental map for this cross, which coalesced into six linkage groups with a marker density of 11.6 cM/marker. The presence of anchor loci common to the EPMP map allowed homologolls linkage groups to be established between the two populations. This study has contributed to the understanding of key morphological traits important in almond breeding programs. The expression and influence of biotic factors on the expression of these traits was also investigated. Understanding factors responsible for kernel taste is also an important objective and this study has contributed to this knowledge. The development of a genetic linkage map will serve as a permanent and practical resource for almond breeders in Australia, and contribute important data to the EPMP. This has significant benefit for Prunus breeders worldwide, and further enhances knowledge on an economically important nut crop / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1141951 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2004
27

The development of a genetic linkage map for almond based on molecular and agronomic markers.

Gregory, Davina January 2004 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Almond, Prunus dulcis, is a tree nut crop that originated in central Asia and is now grown commercially worldwide. Within Australia there exists huge potential gain from optimisation of almond cultivars better suited to Australian conditions. This is the ultimate goal of the Australian Almond Breeding Program, which was established in 1997 at the University of Adelaide. As part of this breeding program a unique hybrid population was developed from a cross between the American self-incompatible cultivar 'Nonpareil' (NP) and European self-compatible cultivar 'Lauranne' (LA). The F₁ population derived from this cross is the focus of this study, the population consisted of 181 individuals, of which 93 were selected for use in the mapping study. Investigation of a number of DNA extraction techniques was performed in order to optimise DNA extraction quality and integrity from almond leaves for future applications in molecular work. To determine if the purported F₁ hybrids were true hybrids, derived from a cross between the cultivars NP and LA, both DNA fingerprinting with cluster analysis and S-allele identification was performed, and the majority of F₁ putative hybrids clustered between the two parents when analysed using the simple matching coefficient and UPGMA. The genetic similarity between individuals comprising the mapping population ranged from 70% to 93% while the parents were 72% similar in comparison to each other. This indicated high genetic variability available for studying heritabilities and for production of a genetic map. Analysing the S-allele complement of all the F₁ hybrids was also performed to offer a more robust method for hybrid determination, since individuals in a breeding population with aberrant S-allele inheritance can be considered non-related. The inheritance of the self-fertility gene is important in breeding programs, since the majority of almond cultivars are self-incompatible, tracking the inheritance of this allele in breeding programs is therefore highly desirable. A detailed morphological study was performed on the whole population over three growing seasons, 2001, 2002, and 2003. In 2001 tree characters such as disease prevalence, bare branches, close internodes, level of upright branches, leaf size and colour were measured. For all the seasons a number of other traits were also measured including: yield, bloom time, self-compatibility, percentage of double kernels, shell hardness, kernel weight, shape, taste, pubescence, and colour. The heritability, genetic variance, segregation and raw correlations between traits were calculated and used to establish a mode of inheritance for these traits. Rainfall and temperature maximum, minimum and monthly averages were collected and used to compare trends in the collected morphological data with these climatic data. A preliminary investigation was undertaken to determine if the cellular structure of the kernel testa epidermis was responsible for the pubescent versus smooth mouth feel of the F₁ hybrids. Light and scanning electron microscopy identified the presence of cellular protuberances arising from the epidermis as a potential cause of the pubescent mouthfeel in almonds. Bulked segregant analysis using inter-simple sequence repeat (ISSR) primers identified a potential marker linked to the pubescent trait which was converted to a sequence characterised amplified region (SCAR), which was also used to screen twelve almond cultivars for this trait. In addition to the use of BSA for the development of markers linked to traits of interest, the development of genetic linkage maps has the potential to greatly enhance current and future breeding programs by MAS. This study produced a genetic linkage map for this population, constructed using random amplified polymorphic DNA (RAPD), ISSR, and simple sequence repeats (SSR), with the mapping program Joinmap 3.0. Two parental maps were constructed, which coalesced into seven linkage groups for the female parent and eight linkage groups for the male parent, corresponding to the chromosome number of eight for almond. The marker density was 9.4 cM/marker for NP and 9.6 cM/marker for LA, covering 65% for the female and male parental maps in compalison to the highly saturated peach x almond map produced by the European Prunus Mapping Program (EPMP). Fourteen markers segregating in both parents were used to produce an integrated parental map for this cross, which coalesced into six linkage groups with a marker density of 11.6 cM/marker. The presence of anchor loci common to the EPMP map allowed homologolls linkage groups to be established between the two populations. This study has contributed to the understanding of key morphological traits important in almond breeding programs. The expression and influence of biotic factors on the expression of these traits was also investigated. Understanding factors responsible for kernel taste is also an important objective and this study has contributed to this knowledge. The development of a genetic linkage map will serve as a permanent and practical resource for almond breeders in Australia, and contribute important data to the EPMP. This has significant benefit for Prunus breeders worldwide, and further enhances knowledge on an economically important nut crop / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1141951 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2004
28

Allergenic cross-reactivity between cashew and pistachio nuts

Tawde, Pallavi D. Roux, Kenneth. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Kenneth Roux, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Jan 18,2005). Includes bibliographical references.
29

Genetic characterisation of Macadamia with DNA markers /

Peace, Cameron Paul. January 1900 (has links) (PDF)
Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.
30

Development of immunological methods and Real-Time PCR for detection of Macadamia nut (Macadamia spp.)

Eliasson, Hanna January 2005 (has links)
<p>A new European labeling directive (2003/89/EC) states that certain foods and products derived thereof must always be declared. Among the tree nuts specified is Macadamia nut (Macadamia spp.). During the last few years, cases of IgE-allergic reactions, even severe anaphylaxes, have been reported. Reliable methods for the detection of this nut are needed.</p><p>Protein from Macadamia nuts was isolated. Polyacrylamide gel electrophoresis in SDS revealed two main protein bands of about 20 and 50kDa. These protein bands were cut and extracted from the gel and rabbits were immunized with each protein.</p><p>Immunoblotting showed dominant reactivity with the respective antigens. The antisera were further tested for specificity in immunodiffusion and in rocket immunoelectrophoresis.</p><p>In addition, a specific DNA-method was developed, based on Real-Time PCR using Macadamia vicilin as target sequence. Two different primer pairs were tested. Specificity was tested against potentially related nuts. Optimisation of primer and probe concentrations was performed. The limit of detection was 2-4 pg DNA, corresponding to a macadamia nut concentration of 50 to 100 μg per g. In a background of soybean DNA, down to 0,01 % macadamia DNA could be detected.</p>

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