[Book Review]Reich, J.A. Calling the Shots: Why Parents Reject Vaccines. New York: New York University Press . 2016. 328pp £20.99 (hbk) ISBN 9781479812790

The springs and the Suwannee river of northern Florida in Middle Suwanee River Basin (MSRB) are among several examples in this planet that have shown a temporal trend of increasing nitrate concentration primarily due to the impacts of non-point sources such as agriculture. The rate of nitrate increase in the river as documented by Ham and Hatzell (1996) was 0.02 mg N L-1 y-1. Best management practices (BMPs) for nutrients were adopted by the commercial farms in the MSRB region to reduce the amounts of pollutants entering the water bodies, however the effectiveness of BMPs remains a topic of interest and discussion among the researchers, environmental administrators and policy makers about the loads of nitrogen entering into groundwater and river systems. Through this study, an initiative was taken to estimate nitrogen losses into the environment from commercial production systems of row and vegetable crops that had adopted BMPs and were under a presumption of compliance with state water quality standards. Nitrogen mass budget was constructed by quantifying the N sources and sinks for three crops (potato (Solanum tuberosum L.), sweet corn (Zea mays L.) and silage corn (Zea mays L.)) over a four year period (2010-2013) on a large representative commercial farm in northern Florida. Fertilizer N was found to be the primary N input and represented 98.0 ± 1.4, 91.0 ± 13.9, 78.0 ± 17.3% of the total N input for potato, sweet corn, and silage corn, respectively. Average crop N uptake represented 55.5%, 60.5%, and 65.2% of the mean total input N whereas average mineral N left in top 0.3 m soil layer at harvest represented 9.1%, 4.5%, and 2.6% of the mean total input N. Mean environmental N losses represented 35.3%, 34.3%, and 32.7% of the mean total input N for potato, sweet corn, and silage corn, respectively. Nitrogen losses showed a linear trend with increase in N inputs. Although, there is no quick fix for controlling N losses from crop production in MSRB, the strategies to reduce N losses must focus on managing the crop residues, using recommended fertilizer rates, and avoiding late-season application of nitrogen

Factors that affect proliferation of Salmonella in tomatoes post-harvest: the roles of seasonal effects, irrigation regime, crop and pathogen genotype

MAIN OBJECTIVES: Fresh fruits and vegetables become increasingly recognized as vehicles of human salmonellosis. Physiological, ecological, and environmental factors are all thought to contribute to the ability of Salmonella to colonize fruits and vegetables pre- and post-harvest. The goal of this study was to test how irrigation levels, fruit water congestion, crop and pathogen genotypes affect the ability of Salmonella to multiply in tomatoes post-harvest. EXPERIMENTAL DESIGN: Fruits from three tomato varieties, grown over three production seasons in two Florida locations, were infected with seven strains of Salmonella and their ability to multiply post-harvest in field-grown tomatoes was tested. The field experiments were set up as a two-factor factorial split plot experiment, with the whole-plot treatments arranged in a randomized complete-block design. The irrigation treatment (at three levels) was the whole-plot factor, and the split-plot factor was tomato variety, with three levels. The significance of the main, two-way, and three-way interaction effects was tested using the (type III) F-tests for fixed effects. Mean separation for each significant fixed effect in the model was performed using Tukey's multiple comparison testing procedure. MOST IMPORTANT DISCOVERIES AND SIGNIFICANCE: The irrigation regime per se did not affect susceptibility of the crop to post-harvest proliferation of Salmonella. However, Salmonella grew significantly better in water-congested tissues of green tomatoes. Tomato maturity and genotype, Salmonella genotype, and inter-seasonal differences were the strongest factors affecting proliferation. Red ripe tomatoes were significantly and consistently more conducive to proliferation of Salmonella. Tomatoes harvested in the driest, sunniest season were the most conducive to post-harvest proliferation of the pathogen. Statistically significant interactions between production conditions affected post-harvest susceptibility of the crop to the pathogen. UV irradiation of tomatoes post-harvest promoted Salmonella growth

Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica

Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro

Ethylene signalling affects susceptibility of tomatoes to Salmonella

Fresh fruits and vegetables are increasingly recognized as important reservoirs of human pathogens, and therefore, significant attention has been directed recently to understanding mechanisms of the interactions between plants and enterics, like Salmonella. A screen of tomato cultivars for their susceptibility to Salmonella revealed significant differences in the ability of this human pathogen to multiply within fruits; expression of the Salmonella genes (cysB, agfB, fadH) involved in the interactions with tomatoes depended on the tomato genotype and maturity stage. Proliferation of Salmonella was strongly reduced in the tomato mutants with defects in ethylene synthesis, perception and signal transduction. While mutation in the ripening-related ethylene receptor Nr resulted only in a modest reduction in Salmonella numbers within tomatoes, strong inhibition of the Salmonella proliferation was observed in rin and nor tomato mutants. RIN and NOR are regulators of ethylene synthesis and ripening. A commercial tomato variety heterozygous for rin was less susceptible to Salmonella under the greenhouse conditions but not when tested in the field over three production seasons

Ethylene signalling affects susceptibility of tomatoes to Salmonella

Fresh fruits and vegetables are increasingly recognized as important reservoirs of human pathogens, and therefore, significant attention has been directed recently to understanding mechanisms of the interactions between plants and enterics, like Salmonella. A screen of tomato cultivars for their susceptibility to Salmonella revealed significant differences in the ability of this human pathogen to multiply within fruits; expression of the Salmonella genes (cysB, agfB, fadH) involved in the interactions with tomatoes depended on the tomato genotype and maturity stage. Proliferation of Salmonella was strongly reduced in the tomato mutants with defects in ethylene synthesis, perception and signal transduction. While mutation in the ripening-related ethylene receptor Nr resulted only in a modest reduction in Salmonella numbers within tomatoes, strong inhibition of the Salmonella proliferation was observed in rin and nor tomato mutants. RIN and NOR are regulators of ethylene synthesis and ripening. A commercial tomato variety heterozygous for rin was less susceptible to Salmonella under the greenhouse conditions but not when tested in the field over three production seasons

Effect of the irrigation regime on the susceptibility of pepper and tomato to post-harvest proliferation of Salmonella enterica

Raw produce is increasingly recognized as a vehicle of human gastroenteritis. Non-typhoidal Salmonella, pathogenic Escherichia coli, and other human pathogens have been isolated from fruits and vegetables in the field and in the marketplace, which led to the hypothesis that these microbes can use plants as alternate hosts. However, environmental and physiological factors that facilitate persistence of these bacteria in the crop production environment and make produce more vulnerable to post-harvest contamination have not been fully delineated. This study tested the effect of irrigation regimes on the susceptibility of peppers and tomatoes to post-harvest proliferation of Salmonella. The experiments were carried out over three experimental seasons in two locations using seven strains of Salmonella. The irrigation regime per se did not affect susceptibility of tomatoes and peppers to post-harvest proliferation of Salmonella; however, in some of the seasons, irrigation regime-dependent differences were observed. Red peppers and tomatoes were more conducive to proliferation of Salmonella than green fruit in all seasons. Inter-seasonal differences were the strongest factors affecting proliferation of Salmonella in peppers

Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica

Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro

Combined Simulation and Experimental Study of Large Deformation of Red Blood Cells in Microfluidic Systems

Author manuscript; available in PMC 2012 March 1.We investigate the biophysical characteristics of healthy human red blood cells (RBCs) traversing microfluidic channels with cross-sectional areas as small as 2.7 × 3 μm. We combine single RBC optical tweezers and flow experiments with corresponding simulations based on dissipative particle dynamics (DPD), and upon validation of the DPD model, predictive simulations and companion experiments are performed in order to quantify cell deformation and pressure–velocity relationships for different channel sizes and physiologically relevant temperatures. We discuss conditions associated with the shape transitions of RBCs along with the relative effects of membrane and cytosol viscosity, plasma environments, and geometry on flow through microfluidic systems at physiological temperatures. In particular, we identify a cross-sectional area threshold below which the RBC membrane properties begin to dominate its flow behavior at room temperature; at physiological temperatures this effect is less profound.Singapore-MIT Alliance for Research and TechnologyUnited States. National Institutes of Health (National Heart, Lung, and Blood Institute Award R01HL094270

Factors that affect proliferation of Salmonella in tomatoes post-harvest: the roles of seasonal effects, irrigation regime, crop and pathogen genotype

MAIN OBJECTIVES: Fresh fruits and vegetables become increasingly recognized as vehicles of human salmonellosis. Physiological, ecological, and environmental factors are all thought to contribute to the ability of Salmonella to colonize fruits and vegetables pre- and post-harvest. The goal of this study was to test how irrigation levels, fruit water congestion, crop and pathogen genotypes affect the ability of Salmonella to multiply in tomatoes post-harvest. EXPERIMENTAL DESIGN: Fruits from three tomato varieties, grown over three production seasons in two Florida locations, were infected with seven strains of Salmonella and their ability to multiply post-harvest in field-grown tomatoes was tested. The field experiments were set up as a two-factor factorial split plot experiment, with the whole-plot treatments arranged in a randomized complete-block design. The irrigation treatment (at three levels) was the whole-plot factor, and the split-plot factor was tomato variety, with three levels. The significance of the main, two-way, and three-way interaction effects was tested using the (type III) F-tests for fixed effects. Mean separation for each significant fixed effect in the model was performed using Tukey's multiple comparison testing procedure. MOST IMPORTANT DISCOVERIES AND SIGNIFICANCE: The irrigation regime per se did not affect susceptibility of the crop to post-harvest proliferation of Salmonella. However, Salmonella grew significantly better in water-congested tissues of green tomatoes. Tomato maturity and genotype, Salmonella genotype, and inter-seasonal differences were the strongest factors affecting proliferation. Red ripe tomatoes were significantly and consistently more conducive to proliferation of Salmonella. Tomatoes harvested in the driest, sunniest season were the most conducive to post-harvest proliferation of the pathogen. Statistically significant interactions between production conditions affected post-harvest susceptibility of the crop to the pathogen. UV irradiation of tomatoes post-harvest promoted Salmonella growth

Crop management information for potato, sweet corn, and silage corn grown at the study farm.

<p>Crop management information for potato, sweet corn, and silage corn grown at the study farm.</p