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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

Creating a decision support model for wild blueberry production returns and pollination services

Carriere, Christine 21 August 2014 (has links)
One agriculture sector that has been greatly affected by a decline in honeybees in the past 2 decades has been the blueberry industry. Blueberries are flowering plants that are dependent on bees for cross pollination. This project was aimed at contributing to the development of a decision support model to aid wild blueberry farmers in Prince Edward Island to quantify their current production costs and increase their understanding of the links between blueberry yield and bee pollination by species. This was done by a) determining the links between blueberry yield and bee pollination, b) calculating the effects of pesticide use on bee abundance c) creating a baseline budget which tallied all of the farmer’s costs for a 2 year blueberry production cycle, and incorporated links between yield and bee pollination of their fields, and d) validating the results of this study with blueberry farmers. Methods of data collection and analysis were both quantitative, while qualitative methods were used to validate the results. Results showed the native bees (bumblebees and Andrena) were much better pollinators than the managed honeybees and leafcutting bees for wild blueberries. Most pesticides used on these farms were highly toxic to bees. Furthermore, many farmers have limited knowledge of creating baseline budgets and therefore may not even know whether their crops are profitable. I recommended that farmers should put more emphasis on increasing the native bee populations in their fields, switch to using low toxicity pesticides when possible and take the time to learn to use baseline budgets to increase their awareness of the financial status of their fields.
2

Effect of Rooting Media, Cultivars and Genotype on the Propagation of Blueberry

Saha, Tripti 12 August 2016 (has links)
The objectives of this research were to study: 1) the effects of five different propagation media containing composted materials on the rooting of semi hardwood blueberry cuttings and 2) the effects of four cultivars and one genotype on rooting responses of these cuttings. The media used were: peat moss and horticulture grade per lite as control, composted pine bark fines with only one-time application of ammonium nitrate, pine bark fines with composted cotton gin waste, hardwood with and composted chicken litter and pine bark with composted chicken litter. There were no significant differences among the media for rooting from semi hardwood cuttings. Cultivars or genotype, media, and the interaction of individual media and cultivar or genotype had effect on rooting responses. Climax and Tifblue showed higher number of rooting from cuttings compared to other lines. Climax had the highest number of callus and survival percentage among all.
3

The Influence of Ericoid Mycorrhizal Fungi on Rabbiteye Blueberry (Vaccinium Ashei)

McLaughlin, Mark Linneaus 15 December 2012 (has links)
Ericoid Mycorrhizal fungi have been shown to form symbiotic associations with Erious plants and increase nutrients uptake by the plant. The objective of this study was to assess the potential of two ericoid mycorrhizal isolates Oidiodendron maius and Pezizella ericae as potential sources of inoculant for rabbiteye blueberry (Vaccinium ashei) and to assess the variation in consistency and degree of ericoid mycorrhizal fungi colonization within rabbiteye blueberry (Vaccinium ashei). Field trials were conducted in 2012 in Verona, MS at the North Mississippi Research and Extension Center. In this study data was collected on fruit yield, leaf tissue nutrient concentration, leaf tissue nitrogen concentration, and percent colonization of root tissue. Ericoid mycorrhizal fungal isolates Oidiodendron maius and Pezizella ericae showed no influence on rabbiteye blueberry (Vaccinium ashei) during this study.
4

Role of Polyphenolic Compounds in Chemoprevention of Breast Cancer Stem Cells

Mallet, Jean-François 22 December 2023 (has links)
In the field of integrative oncology, polyphenols have gained attention for their ability to modulate key signaling pathways involved in breast cancer prevention. One noteworthy product, the Polyphenol-Enriched Blueberry Preparation (PEBP), produced by the fermentation of blueberries by the bacterium Rouxiella badensis subsp. acadiensis has demonstrated various beneficial properties, including anti-inflammatory effects and the ability to control cancer stem cells. Cancer Stem Cells (CSCs) are highly tumorigenic cells involved in carcinogenesis and can cause relapses. MicroRNAs (miRNAs) can act as regulators of CSCs, by controlling stemness and invasion. We postulate that PEBP or its polyphenolic components induce specific epigenetic changes by modulating miRNA networks, reducing CSCs, and preventing breast carcinoma. Thus, the overarching aim of this thesis is to better understand the mechanisms underlying the protective effects of the polyphenol-enriched preparation in mitigating breast cancer. The objectives are: 1. To investigate the chemopreventive effects of PEBP on breast cancer stem cell development in cell models and in vivo, as well as to study the involvement of STAT3 and MAPKs signaling pathways 2. Assess the impact of the polyphenol-enriched blueberry preparation on breast cancer by regulating the expression signatures of miRNA involved with cell proliferation, survival, and CSC self-renewal pathways in in vitro experiments. 3. Characterize PEBP and investigate the effect of a subset of its components on miRNA expression. Furthermore, validate the role of those components in regulating the functional behavior of breast cancer stem cells through experiments using a 4T1 animal model. The results have shown a decrease in the formation of CSCs by delaying the development of tumors in vivo, decreasing metastasis to the lungs, and controlling the PTEN/PI3K/AKT axis, a central node in CSC signaling and homeostasis. In addition, several miRNAs associated with different clinical-pathological characteristics of breast cancer were shown to be differentially expressed in CSCs after exposure to PEBP. Notably, the expression of hypoxamir miR-210, associated with a poor prognosis in breast cancer patients, was downregulated, while tumor suppressor miR-145, which prevents metastasis through FOXO1 was over-expressed. The chemopreventive potential of a polyphenolic mixture containing PCA, gallic acid, and catechin, found in PEBP, was also shown to successfully reduce tumour growth and metastasis in our animal model and decrease the presence of stem-like tumour cells by favouring the upregulation of tumour-suppressor miR-145. These findings provide novel evidence in translational medicine, highlighting the effectiveness of a natural epigenetic modulator in chemoprevention by specifically targeting CSCs.
5

Effects of post-harvest treatments on the microbiological quality and pesticide residues of lowbush blueberries /

Crowe, Kristi Michele, January 2002 (has links)
Thesis (M.S.) in Food Science and Human Nutrition--University of Maine, 2002. / Includes vita. Includes bibliographical references (leaves 69-73).
6

Exportación de arándanos frescos a EE.UU. / Export of fresh blueberries to EE.UU.

Cardenas Huamani, Miguel Angel, Flores Miranda, Bruno Erick, Huaman Canchari, Jhoan Manuel 24 September 2019 (has links)
El presente plan de negocio analiza la viabilidad financiera de desarrollar una línea de negocio para la exportación de arándanos frescos, ya que reconoce una oportunidad en el hecho del cultivo y la comercialización del fruto, con múltiples beneficios para los diversos actores en la exportación hacia un mercado de alta demanda. El mayor importador de arándanos es los EE.UU. con una participación superior al 50% de las importaciones totales a nivel mundial, siendo esto una cantidad por encima de las 214,000.00 toneladas (ITC-Trade Map, presentado en la publicación de la DGPA-MINAGRI); conociendo que se mantiene una tendencia creciente tanto para la producción como la importación en los EE.UU. hace atractivo a los principales exportadores del arándano el mercado norteamericano. El arándano pertenece a la familia de los berries, y existen múltiples especies, el arándano tiene propiedades beneficiosas para la salud humana, una de las principales es el alto contenido de antioxidantes, que contribuye a prolongar la esperanza de vida de los seres humanos, donde hoy en día la tendencia a consumir productos que favorecen la buena salud, cada vez es más adoptada a nivel mundial. Para Perú, el destino de las exportaciones está concentrada principalmente en EEUU, Holanda (Países Bajos), Reino Unido y China, donde los principales exportadores son, Camposol y Talsa; también se debe mencionar que el negocio de la exportación cumple una estacionalidad, que mantiene picos entre los meses de septiembre a diciembre. Estos atributos están incentivando el consumo de arándanos en EE.UU, Europa y Asia; mercados que demandan productos que contribuyan a mejorar la calidad de vida. / The present business plan analyzes the financial viability of developing a line of business for the export of fresh blueberries, recognizing an opportunity in the fact of the cultivation and marketing of fruit, with multiple benefits for the different actors in the exportation to a market of high demand. The largest importer of blueberries is US with a share greater than 50% of the total imports worldwide, which represents an amount above the 214,000.00 tons (ITC-Trade Map, presented in the publication of the DGPA-MINAGRI). Considering that in the U.S. there is a growing trend for both the production and import, the North American market becomes attractive to the leading exporters of blueberry. The blueberry belongs to the family of berries, and there are multiple species. The Blueberry has beneficial properties for human health, one of the main is the high content of antioxidants, which contributes to prolonging the life expectancy of human beings, in a context where the tendency to consume products that promote good health is increasingly adopted worldwide. For Peru, the destination of exports is concentrated mainly in the U.S., Holland (The Netherlands), the United Kingdom and China, being the main exporters “Camposol” and “Talsa”. It should be also mentioned that the export business has a steady season, which maintains peaks among the months of September and December. These attributes are encouraging the consumption of blueberries in the U.S., Europe and Asia; markets that demand products that contribute to improve the quality of life. / Trabajo de investigación
7

Determination of residual hexazinone in Maine's soil and water /

Perkins, L. Brian, January 2002 (has links)
Thesis (Ph. D.) in Food and Nutrition Sciences--University of Maine, 2002. / Includes vita. Includes bibliographical references (leaves 93-98).
8

BLUEBERRY SPANWORM, ITAME ARGILLACEARIA (PACKARD) AND BUMBLE BEE, BOMBUS IMPATIENS (CRESSON) SUSCEPTIBILITY TO NEW BIORATIONAL INSECTICIDES

Ramanaidu, Krilen 09 December 2010 (has links)
Biological and cultural control tactics are available for many agricultural pests but insecticides still play an important role in the rapid reduction of pest incidence when damage reaches economic levels. Laboratory and field toxicities of the reduced-risk products spinetoram and flubendiamide to Itame argillacearia (blueberry spanworm) was compared to deltamethrin, a conventional synthetic pyrethroid insecticide. In laboratory experiments, I. argillacearia larvae were highly susceptible to spinetoram and flubendiamide, and efficacy in the field was comparable to that of deltamethrin. Lethal and sublethal effects of the biopesticide formulations of Beauveria bassiana and Bacillus subtilis, and spirotetramat, a new tetramic acid insecticide, to bumble bees, Bombus impatiens, were also assessed. When ingested, field rates of spirotetramat caused high mortality after a week, and B. subtilis significantly reduced drone production. Field rates of spirotetramat, when applied topically, reduced drone production, but drone production varied following topical treatments of either biopesticide.
9

Optimization of Hydrothermodynamic Technology for Blueberry Food Processing

Satanina, Varvara 31 October 2011 (has links)
Traditional processing technologies can negatively affect polyphenolics of blueberry products. Optimization of hydrothermodynamic (HTD) processing has been used to minimize blueberry-based product quality degradation. Preliminary experiments have shown that the quality of HTD blueberry purée in terms of anthocyanin concentration and tannin content was significantly higher than that of most commercial blueberry products. HTD technology provided pasteurization with significantly lower losses of anthocyanins as compared with conventional heating. Screening of the factors has shown that holding time, temperature of pasteurization and heating rate were significant, while cavitation mode was non-significant. Response surface methodology was used to determine an optimal combination of temperature and time (92 to 95°C with holding time 0.5 to 2.0 min). Non-linear regression analysis of the shelf-life data has provided fitted models which could be used to predict changes in anthocyanin concentration and tannins for different storage periods at 4°C and at room temperature (20 to 25°C).
10

An Ecological Study on Red Sorrel (Rumex acetosella L.) in Wild Blueberry Fields in Nova Scotia

Hughes, Angela D. 18 April 2012 (has links)
Red sorrel is a perennial weed in wild blueberry fields that decreases yield. Multiple experiments were conducted to evaluate its impact on blueberry pollination, Botrytis blight incidence, and berry yield. Kerb applications did not significantly impact blueberry stem or floral bud formation. Removal of red sorrel with Kerb increased blueberry yield at both sites. However a double application had no difference than one application. Blueberry and red sorrel flowering overlapped and red sorrel pollen grains were found on blueberry flowers in both years at all sites. Red sorrel pollen grains increased the incidence of germinating spores in Petri dishes and this relationship was adequately modeled with a three parameter, exponential rise to a maximum. Red sorrel pollen significantly increased disease incidence on immature blueberry flowers. Honey bees foraged from blueberry and red sorrel flowers, but there was no evidence to suggest that they favored red sorrel flowers over blueberry flowers.

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