Using results of a socioeconomic survey of nurseries and greenhouses, Tobit regression analysis was used to estimate empirical models to measure the socioeconomic impact of automation or mechanization on annual gross sales, annual employment, and workers' earnings, safety, and retention. The survey was conducted among 87 randomly selected nurseries and greenhouses located in Mississippi, Louisiana, and Alabama, from Dec. 2003 to Mar. 2005. About 20% of all the identified major tasks were performed by workers in nurseries and greenhouses with some form of mechanization or automation. Regression results showed that nurseries and greenhouses that experienced higher levels of sales also demonstrated higher levels of automation or mechanization. The employment impact of automation or mechanization was neutral, indicating that any improvement in automation or mechanization did not necessarily lead to a reduction, but instead to a more efficient use of labor by nurseries and greenhouses. Improvements in automation or mechanization resulted in higher total workers' earnings reported by participating nurseries and greenhouses. Further Tobit regression results showed that automation or mechanization had neutral effects on the length of training period, workers' safety, and retention rates and enabled nurseries and greenhouses to hire less-skilled workers.

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This work describes workers’ socioeconomic characteristics and evaluates the determinants of workers hiring decisions among 215 randomly selected wholesale nurseries and greenhouses located in eight selected southern states in the United States. The participating nurseries and greenhouses employed on average 5.40 permanent workers per horticulture operation or 2.27 permanent workers per acre under cultivation. Participating nurseries and greenhouses hired an average 2.38 part-time workers per horticulture operation or 0.80 part-time workers per acre placed under production. Empirical models were estimated to determine the significant factors affecting hiring decisions by this industry. Hiring decision models covered age groups, racial backgrounds, formal education levels, and gender. Analysis of the decision-making process involving the employment of hired workers among the participating wholesale nurseries and greenhouses provided insights into the hiring decisions in the industry. The hiring decisions by demographic characteristics serve as benchmarks for assessing impacts of regulations affecting the industry in the near future. About 1.9% of all the establishments employed more than 50 permanent and part-time workers and 1.4% employed more than 50 permanent workers.

In this study, we investigated the inactivation of human norovirus (HuNoV) surrogate Murine norovirus (MNV-1) by X-ray in whole-shell Atlantic oysters (Crassostrea virginica). We also investigated the effects of X-ray treatments on the survivability, inherent microbiota, color, and firmness of treated whole-shell Atlantic oysters during storage at 5 o C for 20 days. Plaque assays revealed that X-ray significantly reduced the population of internalized MNV-1 in live oysters from 4.3 ± 0.4 log PFU g-1 to 3.6 ± 0.5, 3.2 ± 0.2, 2.8 ± 0.2, and 2.5 ± 0.1 log PFU g-1 , by 1.0, 2.0, 3.0, and 4.0 kGy X-ray, respectively. The population of MNV-1 was reduced to less than 2.0 log PFU g-1 at 5.0 kGy X-ray. The survivability of live oysters was not significantly affected by treatment with 1.0 and 5.0 kGy X-ray, in comparison with the control, for up to 15 and 10 days, respectively, during storage at 5°C. Treatment of whole-shell oysters by 5.0 kGy X-ray significantly reduced the inherent microbiota and kept them lower than the control until day 20. No significant effect of X-ray treatment on oyster color or firmness was detected.

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