Comparison of Crop Contamination by Microorganisms during Subsurface Drip and Furrow Irrigation

This study was conducted to compare subsurface drip irrigation (SDI) with furrow irrigation (FI) in crop contamination with microbial-contaminated water irrigation. Escherichia coli, Clostridium perfringens, and coliphage PRD-1 were added to water used to irrigate cantaloupe, lettuce, and bell pepper. Samples of produce, surface, and subsurface (10?cm) soil for each irrigation system were collected on Days 1, 3, 5, 7, 10, and 14 after the application of the study microorganisms. Overall, greater contamination of produce occurred in FI plots than in SDI plots. The microorganisms were detected on the surfaces of cantaloupe and lettuce, but were never recovered on the bell peppers. The greatest amount of contamination occurred with PRD-1 on cantaloupe. The study microorganisms survived longer in the subsurface soil than the soil surface. PRD-1 showed greater persistence than E. coli in soil, while C. perfringens experienced little inactivation during the experiment periods. This study showed that subsurface drip irrigation has great potential to reduce health risks when microbial-contaminated water is used for irrigation water.     

Microfluidic cell electroporation using a mechanical valve

A microfluidic electroporation technique is demonstrated based on the operation of an elastomeric valve in a poly(dimethylsiloxane) (PDMS) fabricated microchip and a common dc power supply. The pulse needed for permeabilization of the cell membrane is generated by temporarily interrupting the circuit using the valve. The electropermeabilization of suspended and adherent Chinese hamster ovary cells with green DNA dye SYTOX is demonstrated. The technique eliminates the cost and complexity associated with a pulse generator and microfabricated electrodes that are often involved in microscale electroporation devices. It also offers the potential of integrating electroporation as a unit operation in large-scale microfluidic systems with the increasing application of elastomeric valves in these systems.     

In vitro testing of commercial and potential probiotic lactic acid bacteria

Probiotics are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host. The objective of this study was to investigate the diversity of selected commercial and potential probiotic lactic acid bacteria using common in vitro screening assays such as transit tolerance in the upper human gastrointestinal tract, adhesion capacity to human intestinal cell lines and effect on epithelial barrier function. The selected bacteria include strains of Lactobacillus plantarum, Lactobacillus pentosus, Lactobacillus farciminis, Lactobacillus sakei, Lactobacillus gasseri, Lactobacillus rhamnosus, Lactobacillus reuteri and Pediococcus pentosaceus. Viable counts after simulated gastric transit tolerance showed that L. reuteri strains and P. pentosaceus tolerate gastric juice well, with no reduction of viability, whereas L. pentosus, L. farciminis and L. sakei strains lost viability over 180min. All strains tested tolerate the simulated small intestinal juice well. The bacterial adhesion capacity to human intestinal cells revealed major species and strain differences. Overall, L. plantarum MF1298 and three L. reuteri strains had a significant higher adhesion capacity compared to the other strains tested. All strains, both living and UV-inactivated, had little effect on the epithelial barrier function. However, living L. reuteri strains revealed a tendency to increase the transepithelial electrical resistance (TER) from 6 to 24h. This work demonstrates the diversity of 18 potential probiotic bacteria, with major species and strain specific effects in the in vitro screening assays applied. Overall, L. reuteri strains reveal some interesting characteristics compared to the other strains investigated.     

Variations in the polyphenol content of seeds of field grown Amaranthus genotypes

In a cultivation experiment 18 different Amaranthus genotypes were cultivated in parallel in Argentina, Mexico, Spain and two different locations in the Czech Republic. The ripe seeds were analysed for their content of 11 polyphenols and the variations among genotype, species and location were analysed by principal component analysis (PCA). The flavonoid, rutin, exhibited large variations with varying environmental conditions whereas the flavonoid, nicotiflorin, was affected less. Amaranthus hypochondriacus displayed the most stable content of polyphenols with a high end content of flavonoids. The variations between location/environmental condition were primarily described by the variations in the content of p-coumaric acid and protocatechuic acid in the seed samples.     

The phenomenon of walking: diverse and dynamic

Everyday walking is a far-reaching activity with the potential to increase health and well-being in the general public. From a phenomenological perspective, walking can be seen as a function of being-in-the-world, where the landscape, a sense of place, and the moment are closely entwined with the walker’s own lived experiences. Using interviews with 73 walkers in a medium-sized town in Norway, this article explores the phenomenon of everyday walking. The data illustrate the multiple ways in which people emphasise well-being and ascribe meaning to their walking experiences, and how these ways may vary significantly during a life course, from day to day, and even within a single walk. Insights from this study may prove useful to policy-makers and administrative bodies in acknowledging people’s various needs and gains related to everyday walking, and hence for promoting a diversified management of walking within the field of health policy, as well as in urban planning for walkable cities.     

Investigation of bitterness in carrots (Daucus carota L.) based on quantitative chemical and sensory analyses

Bitterness is considered as an undesirable taste of carrots. Quantitative chemical analysis of potential bitter compounds of different carrot genotypes was combined with sensory analysis in order to identify key compounds likely to be responsible for the bitterness of carrots. Eight carrot genotypes (‘Bolero’, ‘Mello Yello’, ‘Nairobi’, ‘Tornado’, ‘Purple Haze’, ‘Line 1’, ‘Line 2’, and ‘Line 3’) representing extremes in sensory-perceived odour, flavour, and taste. Potential bitter compounds like polyacetylenes, isocoumarins and phenolic acids were quantified in the peel and the corresponding peeled carrot, and their contribution to bitterness in raw carrots was analysed by sensory profiling using multivariate data analysis. Falcarindiol and a di-caffeic acid derivative were highly related to bitterness in contrast to falcarinol and other potential bitter compounds. Falcarindiol and the di-caffeic acid derivative were primarily present in the peel whereas falcarinol was almost evenly distributed in the root. Investigation of bitterness revealed that high sugar content to some extent could mask the bitter perception of carrots. As falcarinol is the most bioactive of the carrot polyacetylenes the results of the present study indicate that there is a basis for improving the health effects of raw carrots without affecting sensory quality.     

Analysis of Orientation Relations Between Deformed Grains and Recrystallization Nuclei

Nucleation in 30 pct rolled high-purity aluminum samples was investigated by the electron backscattering pattern method before and after annealing. A total of 29 nuclei including two twins were observed, and approximately one third of these nuclei had orientations not detected in the deformed state. Possible orientation relations between these nuclei and the deformed state were by 20 to 55 deg rotation around á 111 ñ ,   á 112 ñ ,   á 100 ñ ,\text or á 110 ñ \left\langle {111} \right\rangle ,\;\left\langle {112} \right\rangle ,\;\left\langle {100} \right\rangle ,{\text{ or }}\left\langle {110} \right\rangle axes. These axes were compared with the active slip systems, and the crystallographic features of the deformation-induced dislocation boundaries. Good agreement was found between the á 111 ñ \left\langle {111} \right\rangle rotation axes and the normal to slip planes with which dislocation boundaries align. The exact nucleation mechanism has not been established, but the observed orientation relations allow for prediction of which grains are likely to form á 111 ñ \left\langle {111} \right\rangle rotated nuclei, although these may not all do so.