Ecological factors influencing survival and growth of human pathogens on raw fruits and vegetables

2002 ◽  
Vol 4 (4) ◽  
pp. 413-423 ◽  
Author(s):  
Larry R. Beuchat
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Anna P. Rodrigues ◽  
Elena Moltchanova ◽  
David A. Norton ◽  
Matthew Turnbull

AbstractBiotic factors such as the presence of invasive animal and/or plant species are well known as major causes of ecological degradation and as limiting either natural or assisted (human-induced) ecological restoration. However, abiotic aspects of the landscape, such as water availability and soil physical/chemical conditions can also potentially limit restoration and should be considered. Dryland ecosystems are amongst the world’s most threatened and least protected. New Zealand’s drylands have been drastically changed, initially through burning, agricultural and grazing practices and the impacts of introduced herbivores and plants. This research aimed at identifying some of the key environmental factors preventing the reestablishment of native woody species in a New Zealand dryland ecosystem. The experiments involved a combination of shading, irrigation and grazing exclusion. The results showed that supplemental water was not beneficial for the survival and growth of the native seedlings, unless combined with shade. Fencing proved important for establishment, even though the species used are regarded in the literature as unpalatable to herbivores. The results indicated that the presence of shade was fundamental for the establishment and growth of the native seedlings likely due to improvements in the microclimate, soil aeration, and water availability to seedlings.


2020 ◽  
Vol 287 (1940) ◽  
pp. 20202500
Author(s):  
Stav Talal ◽  
Arianne J. Cease ◽  
Jacob P. Youngblood ◽  
Ruth Farington ◽  
Eduardo V. Trumper ◽  
...  

Locusts are major intermittent threats to food security and the ecological factors determining where and when these occur remain poorly understood. For many herbivores, obtaining adequate protein from plants is a key challenge. We tested how the dietary protein : non-structural carbohydrate ratio (p : c) affects the developmental and physiological performance of 4th-5th instar nymphs of the South American locust, Schistocerca cancellata, which has recently resurged in Argentina, Bolivia and Paraguay. Field marching locusts preferred to feed on high carbohydrate foods. Field-collected juveniles transferred to the laboratory selected artificial diets or local plants with low p : c. On single artificial diets, survival rate increased as foods became more carbohydrate-biased. On single local plants, growth only occurred on the plant with the lowest p : c. Most local plants had p : c ratios substantially higher than optimal, demonstrating that field marching locusts must search for adequate carbohydrate or their survival and growth will be carbohydrate-limited. Total body lipids increased as dietary p : c decreased on both artificial and plant diets, and the low lipid contents of field-collected nymphs suggest that obtaining adequate carbohydrate may pose a strong limitation on migration for S. cancellata . Anthropogenic influences such as conversions of forests to pastures, may increase carbohydrate availability and promote outbreaks and migration of some locusts.


Author(s):  
Martina Zámková ◽  
Martin Prokop ◽  
Radek Stolín

Our paper explores the factors influencing the consumers who buy organic food. Analysis of these factors enabled us to sort the consumers into groups based on their gender, age, education, and other identifiers. Further research then revealed more detailed shopping preferences of each one of those groups. The findings generated recommendations for producers and organic produce vendors on the best way to provide target marketing for different groups of consumers and therefore increase their sales of organic produce and food made from organic produce. Considering the use of categorical data, contingency tables and correspondence maps served as the best representation and processing tools. Data analysis showed that organic produce is most frequently purchased by respondents in the age of 45+ years, who also tend to spend more money for this range of products. At the same time, these would be the respondents, who struggle the most when recognizing organic produce and who have often never seen any advertisement for it. The respondents aged 25 years and less tend to purchase organic produce least frequently; they also often do not care about the origin of organic produce. Almost the same applies to families with multiple children. However, young respondents often grow their own organic produce. There is still a not insignificant percentage of consumers, who consider organic produce to be expensive and who do not believe in their qualities. As it turns out, when it comes to organic produce the respondents purchase most frequently fruits and vegetables, milk and dairy products.


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