15 resultados para Sweet potato weevil

em Brock University, Canada


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Divino Mucciante with his first prize entry "A Sweet December Winter" on September 19th, 1977.

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The allele-specific polymerase chain reaction (PCR) was used to screen for the presence of benomyl resistance, and to characterize their levels and frequencies in field populations of Venturia inaequalis during two seasons. Three hundred isolates of V. inaequalis were collected each season from infected leaves of MalusX domestica. Borkh c.v. Mcintosh. The trees used were sprayed in the year prior to collection with five applications of benomyl, its homologue Azindoyle, or water. Monoconidial isolates of V. inaequalis were grown on 2% potato dextrose agar (PDA) for four weeks. Each isolate was taken from a single lesion from a single leaf. Total genomic DNA was extracted from the four week old colonies of V. inaequalis, prepared and used as a template in PCR reactions. PCR reactions were achieved by utilizing allele-specific primers. Each primer was designed to amplify fragments from a specific allele. Primer Vin was specific for mutations conferring the ben^^"^ phenotype. It was expected to amplify a 171 bp. DNA fragment from the ben^"^ alleles only. Primers BenHR and BenMR were specific for mutations conferring the ben"" and ben'^'' phenotypes, respectively. They were expected to amplify 172 bp. and 165 bp. DNA fragments from the ben"" and ben"^" alleles, respectively. Of the 953 isolates tested, 414 (69.9%) were benomyl sensitive (ben^) and 179 (30.1%) were benomyl resistant. All the benomyl resistant alleles were ben^"", since neither the ben"" nor the ben"" alleles were detected. Frequencies of benomyl resistance were 23%, 24%, and 23% for the 1997 collections, and were 46%, 26% and 38% for the 1998 collections for benomyl, Azindoyle and water treatments, respectively. Growth assay was performed to evaluate the applicability of using PCR in monitoring benomyl resistance in fungal field populations. Tests were performed on 14 isolates representing the two phenotypes (ben^ and ben^"'' alleles) characterized by PCR. Results of those tests were in agreement with PCR results. Enzyme digestion was also used to evaluate the accuracy and reliability of PCR products. The mutation associated with the ben^"'' phenotype creates a unique site for the endonuclease enzyme Bsh^236^ allowing the use of enzyme digestion. Isolates characterized by PCR as ben^'^'^ alleles had this restriction site for the SsA7l2361 enzyme. The most time consuming aspect of this study was growing fungal isolates on culture media for DNA extraction. In addition, the risk of contamination or losing the fungus during growth processes was relatively high. A technique for extracting DNA directly from lesions on leaves has been used (Luck and Gillings 1 995). In order to apply this technique in experiments designed to monitor fungicide resistance, a lesion has to be homogeneous for fungicide sensitivity. For this purpose, PCR protocol was used to determine lesion homogeneity. One hundred monoconidial isolates of V. inaequalis from 10 lesions (10-conidia/ lesion) were tested for their phenotypes with respect to benomyl sensitivity. Conidia of six lesions were homogeneous, while conidia of the remaining lesions were mixtures of ben^ and ben^ phenotypes. Neither the ben" nor the ben' phenotype was detected.

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Icewine is an intensely sweet, unique dessert wine fennented from the juice of grapes that have frozen naturally on the vine. The juice pressed from the frozen grapes is highly concentrated, ranging from a minimum of 35° Brix to approximately 42° Brix. Often Icewine fennentations are sluggish, taking months to reach the desired ethanol level, and sometimes become stuck. In 6 addition, Icewines have high levels of volatile acidity. At present, there is no routine method of yeast inoculation for fennenting Icewine. This project investigated two yeast inoculum levels, 0.2 gIL and 0.5 gIL. The fennentation kinetics of inoculating these yeast levels directly into the sterile Icewine juice or conditioning the cells to the high sugar levels using a step wise acclimatization procedure were also compared. The effect of adding GO-FERM, a yeast nutrient, was also assessed. In the sterile fennentations, yeast inoculated at 0.2 gIL stopped fennenting before the required ethanol level was achieved, producing only 7.8% (v/v) and 8.1 % (v/v) ethanol for the direct and conditioned inoculations, respectively. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 12.2% (v/v) ethanol, whereas the direct inoculum produced 10.5% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the rate of biomass accumulation, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was no significant difference in acetic acid concentration in the final wines across all treatments. Fennentations using unfiltered Icewine juice at the 0.5 gIL inoculum level were also compared to see if the effects of yeast acclimatization and micronutrient addition had the same impact on fennentation kinetics and yeast metabolite production as observed in the sterile-filtered juice fennentations. In addition, a full descriptive analysis of the finished wines was carried out to further assess the impact of yeast inoculation method on Icewine sensory quality. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 11.5% (v/v) ethanol, whereas the direct inoculum produced 10.0% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the peak viable cell numbers, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was a significant difference 7 in acetic acid concentration in the final wines across all treatments and all treatments affected the sensory profiles of the final wines. Wines produced by direct inoculation were described by grape and raisin aromas and butter flavour. The addition of GO-FERM to the direct inoculation treatment shifted the aroma/flavour profiles to more orange flavour and aroma, and a sweet taste profile. StepWise acclimatizing the cells resulted in wines described more by peach and terpene aroma. The addition of GO-FERM shifted the profile to pineapple and alcohol aromas as well as alcohol flavour. Overall, these results indicate that the addition of GO-FERM and yeast acclimatization shortened the length of fermentation and impacted the sensory profiles of the resultant wines.

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The Impact of the Multicolor Asian Lady Beetle (Harmonia axyridis) on Niagara Wine Quality The possible influence of Harmonia axyridis (the Multicolored Asian Lady Beetle) on the sensory properties of wine was investigated. H. axyridis beetles were added to white and red grape musts at a rate of 0, 1 or 10 per L, and a trained panel evaluated the finished wines using flavor-profiling techniques. Significant modification of both wine aroma and flavor characteristics were observed in the 10 beetlelL treatments, with smaller effects noted at the 1 beetlelL rate. Vinification in the presence of H. axyridis gave higher intensity scores for peanut, bell pepper and asparagus aromas and flavors in the white wines, and peanut, asparagus/bell pepper, and earthy/herbaceous aromas and flavors in the red wines. In addition, sweet, acid and bitter tastes were affected in red wines, and a general trend of decreasing fruit and floral intensities with increasing beetle rate was observed in both white and red wines. 15 ngIL Isopropylmethoxypyrazine was added to control wines and sensory profiles similar to high beetle treatments were obtained, supporting the hypothesis that methoxypyrazines from beetles are implicated in the taint. A trained panel evaluated the treated wines after 10 months of aging using the same sensory methods described above. Sensory profiles were very similar. Fennenting in the presence of Harmonia Axyridis (HA) had little influence on the chemical composition of the ftnished wine. The notable exception IS Isopropylmethoxypyrazine content, which was assessed usmg GC-MS analysis and showed increased concentration with increasing beetle nwnber for both white and red wmes. The influence of potential remedial treatments on the sensory properties of white and red wines tainted by Harmonia axyridis were also investigated. Bentonite, activated charcoal, oak chips, de-odorized oak chips, and UV or light irradiation were applied to tainted wine, and these wines evaluated chemically and sensorially. Both white and red wines treated with oak chips had strong oak characteristics, which masked the Harmonia axyridis-associated aroma and flavour attributes. In red wine, asparagus/bell pepper characteristics were decreased by bentonite and charcoal treatments. Only activated charcoal significantly decreased methoxypyrazine levels and only in white wine.

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The effects of metiram (Polyram 80 DF) on the growth of Venturia inaequalis, cause of apple scab, and the degradation of metiram were examined in culture media. Samples of V. inaequalis conidia were collected from nine orchards in 1998 and six orchards in 1999 and tested for sensitivity. Samples were plated on water agar amended with metiram or mancozeb. Mean EC50 values (effective concentration of fungicide required to inhibit germination of half the conidia) for each population were calculated. The mean EC50 values for metiram ranged from 0.26 - 1.20 ^ig metiram a.i./ml, with differences (Student Newman Keul's Test (SNK), a=0.05) between populations. EC50 values for mancozeb ranged from 0.06 - 0.58 which were also different (SNK, a=0.05). Five of these populations were examined for mycelial growth sensitivity to metiram by testing 30 monoconidial isolates from each population on metiram amended potato dextrose agar. Mean EC50 values for populations were calculated and ranged from 3.44-5.94 |ig metiram/ml, and showed differences (Friedman Test, a=0.05). As the EC50 values obtained are far less than the concentrations applied in the field, results indicate that Ontario populations of V. inaequalis are still sensitive to metiram and mancozeb. The stability of metiram in PDA at 22°C was studied over a 10-day period. The initial concentration of metiram decreased by approximately 50% within the first day, and continued to decline slowly, to approximately 20% of the initial concentration. The factors possibly affecting initial metiram degradation, including agar, heat, and the use of glass or polystyrene Petri dish composition were examined. The effects from the polystyrene in the Petri dish composition were negligible, however more studies must be done to examine metiram degradation during the first 24 hours of preparation.

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Arabidopsis is a model plant used to study disease resistance; Solanum tuberosum or potato is a crop species. Both plants possess inducible defense mechanisms that are deployed upon recognition of pathogen invasion. Transcriptional reprogramming is crucial to the activation of defense responses. The Pathogenesis-Related (PR) genes are activated in these defense programs. Expression of Arabidopsis PR-l and potato PR-10a serve as markers for the deployment of defense responses in these plants. PR-l expression indicates induction of systemic acquired resistance (SAR). Activation of SAR requires accumulation of salicylic acid (SA), in addition to the interaction of the non-expressor of pathogenesis-related genes I (NPRI), with the TGA transcription factors. The PR-10a is activated in response to pathogen invasion, wounding and elicitor treatment. PR-10a induction requires recruitment of the Whirly I (Whyl) activator to the promoter. This locus is also negatively regulated by the silencer element binding factor (SEBF). We established that both the PR-l and PR-10a are occupied by repressors under non-inducing conditions. TGA2 was found to be a constitutive resident and repressor of PR-l, which mediates repression by forming an oligomeric complex on the promoter. The DNA-binding activity of this oligomer required the TGA2 N-terminus (NT). Under resting conditions we determined that the PR-10a is bound by a repressosome containing SEBF and curiously the activator Pto interacting protein 4 (Pti4). In the context of this repressosome, SEBF is responsible for PR-10a binding, yet rWe also showed that PR-l and PR-10a are activated by different means. In PR-l activation the NPRI NT domain alleviates TGA2-mediated repression by interacting with the TGA2 NT. TGA2 remains at the PR-l but adopts a dimeric conformation and forms an enhanceosome with NPRl. In contrast, the PR-10a is activated by evicting the repressosome and recruiting Why! to the promoter. These results advance our understanding of the mechanisms regulating PR-l and PR-10a expression under resting and inducing conditions. This study also revealed that the means of regulation for related genes can differ greatly between model and crop s

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Icewine is a sweet dessert wine fermented from the juice of grapes naturally frozen on the vine. The production of Icewine faces many challenges such as sluggish fermentation, which often yields wines with low ethanol, and an accumulation of high concentration of volatile acidity, mainly in the form of acetic acid. This project investigated three new yeast strains as novel starter cultures for Icewine fermentation with particular emphasis on reducing acetic acid production: a naturally occurring strain of S. bayanus/S. pastorianus isolated from Icewine grapes, and two hybrids between S. cerevisiae and S. bayanus, AWRI 1571 and AWRI 1572. These strains were evaluated for sugar consumption patterns and metabolic production of ethanol, glycerol and acetic acid, and were compared to the performance of a standard commercial wine yeast KI-VI116. The ITS rONA region of the two A WRI crosses was also analyzed during fermentations to assess their genomic stability. Icewine fermentations were performed in sterile filtered juice, in the absence of indigenous microflora, and also in unfiltered juice in order to mirror commercial wine making practices. The hybrid A WRI 1572 was found to be a promising candidate as a novel starter culture for Icewine production. I t produced 10.3 % v/v of ethanol in sterile Riesling Icewine fermentations and 11.2 % v/v in the unfiltered ones within a reasonable fermentation time (39 days). Its acetic acid production per gram sugar consumed was approximately 30% lower in comparison with commercial wine yeast K I -V 1116 under both sterile filtered and unfiltered fermentations. The natural isolate S. bayanus/S. pastorianus and AWRI 1571 did not appear to be suitable for commercial Icewine production. They reached the target ethanol concentration of approximately 10 % v/v in 39 day fermentations and also produced less acetic acid as a function of both time and sugar consumed in sterile fermentations compared to KI-V1116. However, in unfiltered fermentations, both of them failed to produce the target concentration of ethanol and accumulated high concentration of acetic acid. Both A WRI crosses displayed higher loss of or reduced copies in ITS rDNA region from the S. bayanus parent compared to the S. cerevisiae parent; however, these genomic losses could not be related to the metabolic profile.

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A weekly paper that was published from 1805 to 1814. War related news includes: Page 95 - Weekly Retrospect: relief effort in London, England for those affected by the war in British North America; naval battles on Lake Ontario by Commodore Chauncey in late September; movements of Major Grant, De Rottenburgh's regiment, General Wilkinson, Commodore Yoe's fleet, General Hampton; the capture of Fort Malden by William Harrison. The rest of the newspaper contains literary works (poems and translations), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

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A weekly paper that was published from 1805 to 1814. War related news includes: Page 99 - Weekly Retrospect: American report on British naval movements near Louisiana; General William Harrison reports on: a victory at Moravian Town (Moraviantown) on October 5; Ottawas, Chippewas, Wyandots Miamies and Delaware First Nations (Indians) leaving the British side; Tecumseh remaining with the British; American army and navy attempt for a reduction of Mackinac and St. Joseph's; Colonel Chapin attacking a British picket guard near Fort George on October 6; Report that the British have abandoned the Fort George area for Kingston and is being pursued by General McClure; Forces in Sackett's Harbour ready for an attach on Canada; General Provost believed to have left Kingston for Montreal with 1000 men; Report from Burlington (Lake Champlain) of an attack on St. Armands against Colonel Clark on October 15; Report of the American's taking of the Packet Morgiana by the Schooner Saratoga under Captain Adderton by Newport; Announcement by the New York City Common Council for a celebration of Perry and Harrison's victories on the evening of October 23. The rest of the newspaper contains literary works (poems and translations), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

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A weekly paper that was published from 1805 to 1814. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

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A weekly paper that was published from 1805 to 1814. War related news includes: Page 103 - Weekly Retrospect: Reports on the Napoleanic Wars in Europe; Possible French and English troop movements from Europe to America and Canada; Mention of British vessels captured by American privateers Scourge, Rattlesnake and Lion; Report on New York celebration of Commodore Perry and General Harrison's victories on Lake Erie and in Canada respectively; Creek Indians attack on a supply convoy near Savannah, the provisions were recovered by General Floyd; General Harrison's account on Moravian Town (Moraviantown) and Munsey; Movements of General Wilkinson's army. Page 104 - an editorial about the madness of the times and its reflection on humanity. The rest of the newspaper contains literary works (poems and translations), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

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A weekly paper that was published from 1805 to 1814. War related news includes: Page 103 - Weekly Retrospect: Troop movements of Captain Morgan and a company of light dragoons from Niagara to Greenbush; report on the Battle of Queenston Heights including a casualty listing and a mention of the death of Major General Isaac Brock and Colonel McDonald and the American's respect for Brock; British attach of Fort Erie and the Village of Black Rock; the privateer Globe under Captain Murphy returning to Baltimore after capturing a British letter of marque; First Nation / Indian attacks near St. Louis; movements of General W. Harrison and army from Fort Defiance to the rapids of Miama (Miami). The rest of the newspaper contains literary works (poems and translations), essays (including on celibacy), marriages, deaths and other anecdotes. The motto on the front page states: "Visiting Every Flower with Labour Meet, and Gathering all its Treasures, Sweet by Sweet."

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This study has found that youth who or whose parents had left their home country for fear-based reasons were less involved within their school and wider community than youth who left or whose parents left for reasons concerning their social mobility. Many existing studies focus on the challenges newcomer youth experience within the education system (see Anisef, Brown, Phythian, & Sweet, 2010), however through the use of qualitative methodologies this study expanded on the current literature by further examining why it is some youth are successful in overcoming such challenges, while others are not. This study supported what has been demonstrated in the literature regarding challenges faced by newcomer youth and resources to address such challenges. Despite challenges experienced within the education system, youth planned to complete secondary school and attend a postsecondary institution. However, not all youth anticipated remaining in Canada upon completion of their education, with youth or youth whose parents left their home country for fear-based reasons frequently discussing the possibility of returning to their or their parents' home country. Thus, perhaps these youth were less involved within their school, as their goal was not necessarily to establish or maintain connections within their community as they may have viewed residing in Canada as temporary. This finding has important implications, as there are benefits to involvement in extracurricular activities, which may assist youth in overcoming challenges encountered within the education system. Therefore, it would seem that youth who had or whose parents had left their home country for reasons concerning their social mobility may have be at an advantage within the education system with respect to their involvement in school. Perhaps then this differential involvement may at least partially explain why it is some newcomer youth are able to overcome challenges they experience in the education system, while others are not. Both policy and theoretical implications are discussed.

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There are many known taste receptors specific to each taste attribute. This thesis examines the relationship between single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) in known taste and taste pathway receptors TAS2R38, Gustin, and TRPM5 and for PROP (6-n-propylthiouracil) taster status (PTS), thermal taster status (TTS), and orosensory sensation intensity ratings. PTS is a proxy for general taste responsiveness, and the ability to taste PROP classifies individuals into three phenotypes: super (PST), medium (PMT), and non-tasters (PNT). Another taste phenotype, also serving as a proxy for general taste responsiveness, is TTS, classifying individuals as thermal tasters (TTs) or thermal non-tasters (TnTs). DNA extractions from buccal cells obtained from 60 individuals were performed and analysis of TAS2R38, Gustin, and TRPM5 variations were conducted through Polymerase Chain Reaction (PCR), sequencing for SNPs, and upQMPSF for CNV analysis of TRPM5. Among the SNPs and CNVs studied, only TAS2R38 was found to be significantly associated with PTS and intensity ratings for sweet, bitter, and sour taste as well as astringency. However, not all PROP phenotypic differences can be explained by the variations at these three SNP sites in TAS2R38, suggesting the involvement of additional genes. No association was found between TTS and TAS2R38 or Gustin, confirming that PTS and TTS are not genetically associated. The examined TRPM5 SNPs and CNVs did not correlate with TTS. Therefore, further research is necessary into other factors contributing to PTS and TTS.

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Receipt from John Burrow, Plumber and House Furnishings, St. Catharines for potato masher and kettles, Nov. 4, 1887.