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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.
451

Studies on the behaviour of males of California red scale Aonidiella aurantii (Maskell)

Yan, Jwo-Yee. January 1985 (has links) (PDF)
Typescript. Submitted for the degree of Doctor of Philosophy but awarded the degree of Master of Agricultural Science. Bibliography: leaves 76-86.
452

Ecologie et population de Rousettus madagascariensis G. Grandidier, 1928 (Pteropodidae)

Andrianaivoarivelo, Radosoa A. 26 January 2012 (has links) (PDF)
La perte d'habitat et la déforestation sont les principales menaces qui pèsent sur la biodiversité Malgache. Ces processus sont responsables du déclin d'un nombre important d'espèces. Cependant, les mécanismes de ce déclin ne sont pas encore complètement élucidés. En utilisant la roussette malgache (Rousettus madagascariensis) comme un modèle d'organisme, nous nous sommes attachés à étudier les réponses écologiques et génétiques de cette espèce dans des paysages naturels et des paysages modifiés par l'homme et présentant divers types de caractères physico-climatiques à Madagascar. Ayant une large distribution, cette espèce est endémique à Madagascar et assure potentiellement un rôle important dans la régénération naturelle des forêts malgaches. A partir de l'utilisation de la radio télémétrie, d'analyses des matières fécales, d'études moléculaires et de mesures morphométriques nous avons pu examiner le mode de dispersion et l'écologie de cette espèce. L'observation des animaux en volière a fourni des informations importantes sur son choix alimentaire entre plantes autochtones et celles à valeur économique. Dans cette étude, nous avons ainsi mis en évidence : i) que Rousettus madagascariensis utilise les habitats forestiers et ceux modifiés par l'homme pour s'alimenter ; ii) qu'elle a une préférence plus marquée envers les espèces forestières et pionnières qu'envers celles d'importance commerciale ; iii) qu'elle présente une faible mais significative structuration génétique ; iv) mais une variation morphométrique, qui est dépendante de la latitude et de l'altitude.
453

The Effect of Adolescent Physical and Sexual Dating Violence on the Nutritional and Psychological Health of Adolescent Girls

Raiford, Jerris Laverne 12 January 2006 (has links)
The purpose of this study was to explore the stress-eating relation established in the literature by examining a naturally occurring stressor, adolescent dating violence, and its effect on eating in adolescent girls. Specifically, analyses focused on assessing the mediating role of depression in the adolescent dating violence-fruit and vegetable intake relation and the moderating role of sports team involvement in the adolescent dating violence-depression relation. A nationally representative sample of 5,892 black, Hispanic, and white adolescent girls were surveyed using measures assessing physical and sexual dating violence experiences, depressed affect, suicidal thoughts, plans, and/or attempts, fruit and vegetable intake and involvement in team sports. This study supported the hypothesis that depression mediates the relation between adolescent dating violence and dietary intake, but only in black adolescent girls. These findings suggest that black girls victimized by dating violence experience depression, which may affect their desire or motivation to eat properly. This study also supported the hypothesis that sports team involvement, a source of social support and physical activity, moderated the relation between adolescent dating violence and depression and suicidality, but only for white adolescent girls. For this group, participating on a sports team served to protect those girls reporting dating violence from experiencing depression at the high rate reported by those dating violence victims not involved on a sports team. The findings presented in this study provide evidence that depression explains how experiences of dating violence affect eating behavior for a high-risk group, black adolescent girls. Recognizing depression’s contribution to this group’s high rate of obesity and overweight is an important step in preventing obesity and obesity-related outcomes in this population. Also, this study highlights an important source of social support, sports team involvement, and its potential to protect dating violence victims from experiencing depression and suicidal ideation, plans, and attempts.
454

A research of consumer attitudes to fruit snacks : A study of Thai consumers’ attitudes toward vacuum fried crispy fruits

Tandhansakul, Montira, Preechavibul, Nuttawat January 2011 (has links)
Title: A research of consumer attitudes to fruit snacks : A study of Thai consumers‟ attitudes toward vacuum fried crispy fruits Problem : How should Thai snack companies create their appropriate marketing planning of vacuum fried crispy fruits for satisfying Thai target consumer? Purpose: To investigate the Thai consumers‟ attitudes towards the vacuum fried crispy fruits that will be beneficial in creating the appropriate marketing planning as well as to recommend the potential marketing mix of this product to Thai snack companies Method: The research technique used in this study is mainly based on the quantitative method. By mailing the 400 surveys to the Thai respondents in Bangkok, the data will be collected and evaluated by using the statistic software program as well as using the secondary data to be a supportive source in this research. Moreover, there are marketing theories used in analyzing the data in this research in order to be more academic and reliable. Conclusion: The most influence attitude factor that motivates the Thai consumers to purchase this product is the sales promotion, in particular the samples promotion. While their attitudes to the terms of nutritional content and product quality are positive that can influence them to make a decision to purchase this product easier. Keywords: Snack fruits, Product Development, Consumer Behavior, Product Quality and Nutritional Content
455

Fresh fruits and vegetables distribution system in China : Analysis on the feasibility of Agriculturalsuper-docking

Deng, Xuhong, Zhang, Sinan January 2011 (has links)
Background: Along with the rapid economic development in China, some associatingproblems emerged, such as inflation. Especially for the daily consuming fresh fruits andvegetables (FFV), the price goes up at very fast speed, which draws a lot of publicattention on it. Farmers are discouraged and hurt by the low vegetable prices. However,end consumers are complaining about the high vegetable prices. A consensus is reachedthat the problem behind this phenomenon exists in the "distribution links".Aim: How is the current status of FFV distribution system of supermarkets in China?What factors do influence the efficiency and cost of the system? How is theimplementation of ASD in China and what are the advantages and barriers? Should it beimplemented widely? If yes, what are our recommendations to improve it?Definition: Agricultural super-docking is a new method of supply and distribution offresh agricultural products from farmers to supermarkets directly, by signing anagreement of intent between farmers and merchants, in order to build an efficientplatform for quality agricultural products to enter the supermarkets. The essence of ASDis to dock the thousands of small farmers and the different supermarkets to build anintegrated production and marketing chain to gain benefit for merchants, farmers andconsumers at the same time.Completion and results: It is a complex task to improve the efficiency of FFVdistribution system of supermarkets in China and there is a long way to go to implementASD successfully and widely since this market is at the starting stage and immature. Toimplement ASD successfully and widely, professional FFV third-party distributioncenters should be constructed, as well as exchanging information norm.
456

Electron Beam Irradiation for Improving Safety of Fruits and Vegetables

Adavi, Megha Sarthak 2011 May 1900 (has links)
Increase in consumption of fresh cut produce over the past decade has resulted in a rise in incidents of food borne outbreaks due to pathogens. Conventional techniques of sanitizing washes may not be effective since the organic matter released from the fresh produce use up the free chlorine thus reducing the sanitizing potential of wash water just when it is needed most and a heat treatment step to kill pathogens cannot be applied if the purpose is to consume fresh produce. Electron beam (e-beam) irradiation was used to treat cut cantaloupe, cut roma tomatoes, baby spinach, romaine lettuce which were surface inoculated with a cocktail of Salmonella and E. coli O157:H7. Results showed that irradiation reduced Salmonella and E. coli O157:H7 significantly with increasing doses at 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. The D10-value for Salmonella on irradiated cut cantaloupe, cut roma tomatoes, baby spinach, and romaine lettuce was found to be 0.71 kGy, 0.64 kGy, 0.19 kGy, and 0.23 kGy respectively. The D10-value for E. coli O157:H7 on the produce listed above was found to be 0.73 kGy, 0.54 kGy, 0.18 kGy, and 0.20 kGy respectively. Low dose e-beam irradiation was found to be an excellent tool for ensuring the reduction of spoilage organisms and extending shelf life in cut cantaloupe, cut roma tomatoes, baby spinach, romaine lettuce, strawberries, and green onion. The produce were tested for 12 days of storage for aerobic plate count, yeast and mold, lactic bacteria, color, texture, and respiration rate as a function of irradiation doses 0, 1, 3, and 5 kGy. Aerobic plate counts, yeast counts, and lactic acid bacteria were reduced appreciably at all doses tested on all commodities. Molds did not grow on any samples including control for cut cantaloupe, cut tomatoes, and green onion but for the other commodities, mold was reduced at the same rate as yeasts and vegetative bacteria. Lactic acid bacteria were reduced at all doses while the reduction was highest with 5 kGy in all commodities. When irradiated with 5 kGy, during storage, strawberries, spinach, and green onion displayed wet, soggy and mushy appearance, romaine lettuce leaves were wilted, had a translucent midrib and brown pigmentation. E-beam irradiation increased respiration rate for all samples on day 0 compared to non-irradiated control irrespective of the commodity type and the effect was dose dependent. Firmness reduced appreciably for cut roma tomatoes, baby spinach, strawberries, romaine lettuce, and green onion with increasing doses. Cut cantaloupe was low in firmness but the effect was not dose dependent. Irradiation at low doses is a promising tool to reduce pathogens and enhance keeping quality of cut cantaloupe, cut tomatoes, baby spinach, romaine lettuce, strawberries, and green onion. Irradiation is to be implemented as part of an overall HACCP plan and is not meant to replace existing control measures.
457

Effect Of Ultrasound On Drying Rate Of Selected Produce

Kantas, Yesim 01 April 2007 (has links) (PDF)
The objective of this study was to discover the effect of high power direct contact ultrasound on drying rates of apple, celery root, carrot and potato. For this purpose ultrasonic generator with 24 kHz frequency was used and amplitude and pulse mode values were chosen as 40%, 70%, 100%, and 0.4, 0.7, 1.0, respectively. The temperature of drying air was 30&deg / C, 40&deg / C and 50&deg / C and the velocity was kept at 3.9 m/s. The samples used were 13.5 mm in diameter with 5.0 mm thickness. It is found that ultrasound assisted drying increased the drying rate for the selected produce at all the drying conditions used the degree of which depended on the structural properties of samples. Accordingly, the most suitable drying conditions were found to be amplitude 100%, pulse mode 1.0 and 30&deg / C for celery root, amplitude 100%, pulse mode 1.0 and 30&deg / C for apple, amplitude 70%, pulse mode 1.0 and 50&deg / C for carrot and amplitude 70%, pulse mode 0.7 and 50&deg / C for potato. Data obtained were treated with respect to some mathematical models that describe the drying kinetics of samples. In this respect, Page and Modified Page models were the best to represent the drying rates in all cases. Further, the results showed that the effect of ultrasound on drying rate increased in the order of apple&gt / celery root&gt / carrot&gt / potato. That order can be attributed to the structure and composition where presence of air pockets has enhancing and sugar and starch have reducing effects.
458

Studies on the Antioxidative Potential of the Freeze-Dry Extract (Tsan-Ron-Bau-Yuan) of Fruits and Vegetables, DNA Vaccine Against Mycoplasma hyopneumoniae

Wang, Hsiao-Ning 04 August 2000 (has links)
The oxidative damage to DNA, protein and lipid, may be accumulated and play a role in the process of human cell aging. Oxidative stress may be due to the aerobic respiration and ozone-induced radiation which result in reactive oxygen species known as free radicals. Therefore, the antioxidant and free radical scanvenger which may reduce the oxidative damage, are of great interest, both in academic research and in the business world. The present study aims to evaluate the antioxidative potential of a very unique vegetable-fruit extract (Tsan-Ron-Bau-Yuan). The extract consists of over forty domestic vegetables and fruits, without using chemical fertilizers and pesticides during their entire growth period, is produced through a sophisticated freeze-dry technology. The anti-hydroxyl radical antioxidative potential were evaluated using the following four methods: (1) the plasmid DNA (2) the protein (3) the cell line and (4) the red blood cell . The results clearly demonstrat that the aqueous fraction of this extract can remarkably reduce the oxidative damage as evidenced by the DNA and protein model. In addition, the susceptibility of human red cells to oxidative stress can also be alleviated to some extents based on the RBC deformability studies. The efficacy of protection of the oxidative damage mediated by .OH generated by the Fenton¡¦s reaction was in the order of : aquaeous extract >100% ethanol extract > ethanol/ethylacetatee extract > 50% ethanol extract. Conversely, no significant protection to the action of hydrogen peroxide was observed in the cell line. Lysozyme which is ubiquitous among various natural products has negligible contribution as an antioxidant as revealed in the RBC deformability tests. Swine enzootic pneumoniae ¡]SEP¡^, is a disease caused by Mycoplasma hyopneumoniae infection, and usually lead to considerable economic loss. Though extensive research during the past years, the molecular mechanism about the infective pathway of M. hyopneumoniae was still elusive. The membrane proteins of this microorganism were considered as critical adhesion molecules and therefore are potential candidates for vaccine development. Through immunoscreening, we had isolated five recombinant phage clones expressing 10 kDa, 32 kDa, 36 kDa, 42 kDa and 60 kDa antigen proteins from the lEMBL3 library of Mycoplasma hyopneumoniae. The clone carrying the P42 gene was subcloned and further characterized as a heat shock protein gene. In the present study, the heat-shock protein gene encoding a 42 kDa/ 65 kDa protein¡]P42/P65¡^was cloned into the mammalian expression vector pcDNA3 and obtained plasmid pcDNA42. The immune response induced by pcDNA42 was evaluated in mice. The IgG titer was obviously elevated during the first eight weeks with the IgG1 titer slightly higher than IgG2a. However, the IgM titer was not changed signifcantly. Studies on the macrophage activity and T cell cytotoxity were still undergoning.
459

Influence de l'éthylène sur le développement des baies de raisin et expression des gènes apparentés fluence of the ethylene on the grape berry development and related-gene expression /

Tira-Umphon, Arak Chervin, Christian January 2008 (has links)
Reproduction de : Thèse de doctorat : Biosciences végétales : Toulouse, INPT : 2008. / Titre provenant de l'écran-titre. Bibliogr. 163 réf.
460

Phenolic compounds in Ecuadorian fruits /

Vasco, Catalina, January 2009 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 5 uppsatser.

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