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Title: Boycott lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott non-union lettuce; union bug. Red background with black text union eagle

Title: Boycott lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott lettuce; union bug; red background with black text and union eagle

Title: Boikott hodesalat
Date: 1964/1973?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boikott hodesalat USAs uten dette merke; Boycott lettuce, avoid this brand; red background with black text and black union flag symbol.

Title: Boycott non-union lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott non-union lettuce; union bug. Deep red background with black text union eagle

Title: Boycott lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott non-union lettuce union bug. Red background with black text union eagle

Title: No lettuce unless it's union label
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: No lettuce unless it's union label; union bug; white background with red/black text and union flag

Title: Boycott scab lettuce San Diego
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott scab lettuce San Diego; union bug; white and red background with red/black text union eagle

Title: Boycott non-union Lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott non-union lettuce; union bug; white background with red text and black union eagle

Title: Boycott non-union lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott non-union Lettuce; union bug; red background with black text and black union eagle on white center

Title: Boycott! non-union Lettuce
Date: 1969/1980?
Collection: Midwest Chicano Latino Activism Collection (MICHILAC)
Description: Boycott non-union Lettuce; union bug; white background with green text and green illustration of head lettuce

Title: Forcing of lettuce, with some experiments in growing
Creator: Loomis, Charles W.
Date: 1898
Collection: Electronic Theses & Dissertations

Title: Antibiotic resistance and bacterial microbiome in lettuce-soil systems
Creator: Shen, Yike
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Food safety challenges from emerging contaminants such as antibiotics and antibiotic resistance genes (ARGs) have received increasing attention due to rapid increases in their abundance in agroecosystems. This is particularly true in soil-vegetable systems as microbiomes and antibiotic resistomes of vegetables are important to their quality and safety and could be influenced by crop production with contaminated soil and water. Additionally, the food safety of vegetables may also drive...
Show moreFood safety challenges from emerging contaminants such as antibiotics and antibiotic resistance genes (ARGs) have received increasing attention due to rapid increases in their abundance in agroecosystems. This is particularly true in soil-vegetable systems as microbiomes and antibiotic resistomes of vegetables are important to their quality and safety and could be influenced by crop production with contaminated soil and water. Additionally, the food safety of vegetables may also drive consumers' preference and demand for certain food products (especially for labeled products such as USDA Organic, Raised Without Antibiotics, etc.). Using a soil-lettuce (Lactuca sativa) model system, the first study in this dissertation assessed how irrigation with antibiotics-contaminated water via overhead or soil-surface irrigation could influence bacterial communities and ARG profiles in lettuce shoots, roots, and soil, using 16S rRNA amplicon sequencing and high throughput qPCR techniques, respectively. The overall abundance and diversity of ARGs and bacteria associated with soil-surface irrigated lettuce shoots were lower than those under overhead irrigation, indicating soil-surface irrigation may have lower risks of producing food crops with high abundance of ARGs. ARG profiles and bacterial communities were sensitive to pharmaceutical exposure, but no consistent patterns of changes were observed. The second study examined the fate and transport of selected antibiotics through bulk soil, rhizosphere soil, and lettuce roots and shoots under soil-surface irrigation. Root concentration factors based on the antibiotic concentrations in bulk soil (RCFbs) were significantly higher than those based on antibiotic concentrations in rhizosphere soil (RCFrs) for ciprofloxacin, lincomycin, oxytetracycline, sulfamethoxazole, and tetracycline, similar for trimethoprim and tylosin, and lower for monensin. The third study investigated bacterial community assembly and ARG profiles in lettuce shoots, roots, rhizosphere soil, and bulk soil upon exposure to antibiotics. Bacterial communities were driven by stochastic processes upon exposure to low level antibiotics, and were more resilient in roots and rhizosphere soil than in bulk soil and shoots. The fourth study explored the importance of demographics, food-relevant habits, and foodborne disease perception to consumers' buy and pay preferences to labeled products by using conventional statistical and novel machine learning methods to analyze survey data. Consumers' willingness to buy or to pay more for certain labeled food products is dependent on certain demographic traits (e.g., urban living) and food-relevant habits (e.g., cooking fresh produce). Machine learning methods achieved sufficient prediction accuracy scores for estimating consumers' willingness to buy or to pay for labeled products, and thus could be useful tools for evaluating survey data and facilitating the development of strategies promoting healthy food production and consumption.
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Title: The effect of molybdenum and lime applications on the yield and chemical composition of lettuce and cauliflower grown on two Michigan organic soils
Creator: Hosner, Albert William
Date: 1962
Collection: Electronic Theses & Dissertations

Title: Impact of selected unit operations on the spread of Escherichia coli O157 : H7 during pilot-scale production of fresh-cut lettuce
Creator: Ren, Lin
Date: 2014
Collection: Electronic Theses & Dissertations
Description: In response to continued foodborne outbreaks and recalls, two separate studies were conducted to assess the importance of various unit operations in spreading E. coli O157:H7 during production of fresh-cut leafy greens. Initially, E. coli O157:H7 transfer from a contaminated shredder and conveyor belt to previously uncontaminated iceberg lettuce, wash water, and the equipment was quantified during pilot-plant production of fresh-cut lettuce using 9.1 kg of dip-inoculated radicchio (106 CFU/g,...
Show moreIn response to continued foodborne outbreaks and recalls, two separate studies were conducted to assess the importance of various unit operations in spreading E. coli O157:H7 during production of fresh-cut leafy greens. Initially, E. coli O157:H7 transfer from a contaminated shredder and conveyor belt to previously uncontaminated iceberg lettuce, wash water, and the equipment was quantified during pilot-plant production of fresh-cut lettuce using 9.1 kg of dip-inoculated radicchio (106 CFU/g, colored surrogate for iceberg lettuce) to contaminate a pilot-plant-scale shredder or conveyor. After processing 90.7 kg of previously uncontaminated lettuce, average E. coli O157:H7 populations on the shredder and conveyor belt decreased from 3.7 to 0.9 and from 4.1 to 2.5 log CFU/100 cm2, respectively. E. coli O157:H7 levels in twenty 4.5 kg batches of lettuce collected after exiting the contaminated shredder and conveyor also decreased significantly (P < 0.05) from 2.7 to 0.9 and from 1.8 to 0.9 log CFU/g during processing. Thereafter, E. coli O157:H7 transfer from a single inoculated lettuce leaf (6.9 log CFU/g) to wash water was assessed at different water velocities in a custom-made pipe system. Shedding of E. coli O157:H7 from lettuce was significantly greater at a laminar flow rate of 0.01 m/s (5.1 log CFU) (P < 0.05) compared to turbulent flow at 0.07 m/s (3.8 log CFU) and lower laminar flow at 0.005 m/s (3.2 log CFU) with numbers of E. coli O157:H7 peaking in the water after 10, 4, 4, and 3 s at flow rates of 0.005, 0.01, 0.04, and 0.540 m/s, respectively. All of these findings will be useful in the development of bacterial transfer models for current and future risk assessments.
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Title: The growth physics and water relations of red light-induced germination in lettuce seeds
Creator: Nabors, Murray W.
Date: 1970
Collection: Electronic Theses & Dissertations

Title: Rapid concentration/detection of Escherichia coli O157:H7 and Listeria monocytogenes from lettuce wash water
Creator: Gustafson, Ryann Elizabeth
Date: 2017
Collection: Electronic Theses & Dissertations
Description: "Dead-end ultrafiltration concentration (DEUF-C) prior to qPCR or standard enrichment was used to determine presence/absence of Escherichia coli O157:H7 (Ec) and Listeria monocytogenes (Lm) in various lettuce wash waters generated using both a pilot- and commercial scale processing line. After inoculating and pilot-scale processing of the ice berg lettuce, 8 of 24 (33%) of Ec and Lm samples were positive by DEUF-C, but negative by commercial FDA BAM. In addition, populations of both pathogens...
Show more"Dead-end ultrafiltration concentration (DEUF-C) prior to qPCR or standard enrichment was used to determine presence/absence of Escherichia coli O157:H7 (Ec) and Listeria monocytogenes (Lm) in various lettuce wash waters generated using both a pilot- and commercial scale processing line. After inoculating and pilot-scale processing of the ice berg lettuce, 8 of 24 (33%) of Ec and Lm samples were positive by DEUF-C, but negative by commercial FDA BAM. In addition, populations of both pathogens were significantly higher in DEUF-C samples compared to unconcentrated samples after 7 h of enrichment (P < 0.05). Using the commercial-scale processing line, 14 of 14 (100%) samples yielded Ec and Lm using DEUF-C compared to 1 of 15 (6.7%) and 3 of 15 (20%) wash water grab samples, respectively. Higher total filterable volumes were achieved for flume (30.6 + 9.9 L) compared to centrifugation water (9.9 + 2.0 L) (P < 0.05). Ec and Lm were also detected in 16 of 16 (100%) DEUF-C samples compared to 2 of 18 (11.1%) and 3 of 18 (16.7%) grab samples, respectively, from a commercial-scale test facility. These studies indicate that DEUF-C can detect lower levels of Ec and Lm in lettuce wash water compared to standard culture methods. However, the filtration times and total filterable volumes will need to be further improved for commercial produce wash and centrifugation water containing high organic loads."--Page ii.
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