Behavioral responses of rats exposed to long-term dietary vinclozolin

Vinclozolin is a fungicide used on food crops with human exposure estimated at approximately 2 microg/kg/day from ingestion; occupational exposure, however, may be greater. The metabolites of vinclozolin have been reported to act as antiandrogens and have adverse effects on reproductive physiology and behavior in animals. Here, pregnant rats were fed soy-free diets containing 0, 10, 150, or 750 ppm of vinclozolin (approximately 0, 0.8, 12, and 60 mg/kg/day for an adult) beginning on gestational day 7, and offspring were continued on these diets through sacrifice at postnatal day 77. Male and female offspring were assessed for changes in several nonreproductive sexually dimorphic behaviors: open field and running wheel locomotor activity, play behavior, and consumption of saccharin- and sodium chloride-flavored solutions. There was a significant interaction of sex with vinclozolin exposure on running wheel activity, which indicated that females in the high-dose exposure group were hypoactive compared to same-sex controls. There was a significant overall effect of vinclozolin exposure on fluid consumption, and high-dose animals showed increased intake of the saccharin solution and decreased intake of plain water while saccharin was available. Effects were more pronounced in females, which drank 40.8% more saccharin than control females, whereas males drank 6.2% more than control males. There were no effects of vinclozolin treatment on play behavior or sodium solution intake. Gestational duration, total and live pups per litter, litter sex ratios, and birth weight were also not significantly affected, nor were body weight and food intake for dams and offspring. These results indicate that long-term dietary exposure to vinclozolin does not have severe toxicological consequences on the nonreproductive behaviors measured here. However, exposure may cause subtle alterations in locomotor activity and consumption of saccharin-flavored solution.     

Where systems biology meets postharvest

According to the dictionary, a system is something like “a group or combination of interrelated, interdependent, or interacting elements forming a collective entity”. In postharvest, fresh harvested food crops can be considered isolated small scale systems. Postharvest research aims to understand the quality of these ‘systems’ as influenced by postharvest conditions. The phenotypic quality of horticultural produce is based on genetic traits that are expressed through a cascade of reactions subject to complex regulatory mechanisms and diverse environmental conditions. Ultimately, to fully understand postharvest phenomena, a systemic approach that links genetic and environmental responses and identifies the underlying biological networks is required. Thanks to the development of high throughput omics techniques such system-wide approaches have become a viable option to support traditional postharvest research. This review provides an overview of systems biology and how it can lead postharvest research into a new era.     

Educational Resources for Precision Agriculture

As site-specific management evolved into precision agriculture and began to be adopted by producers in the late 1980s and early 1990s, information about precision agriculture emerged in a variety of forms. Much of the information was initially available only in industry guides and popular press articles, such as Successful Farming and Farm Journal. Today, a variety of educational resources for both producers and advisors on precision agriculture has emerged, including books, proceedings of conferences, Extension bulletins, newsletters, industry guides, and multimedia modules. Recently, the Internet has had a significant influence on the production and dissemination of information on precision agriculture. The Internet has been a particularly valuable mode of information exchange due to the rapid evolution of technology and practices associated with precision agriculture, and because many of the early adopters of precision agriculture technologies were also early adopters of electronic communication technologies.     

Stepwise formation of multilayered nanostructural films from macromolecular precursors

Sequential adsorption of a cationic polyelectrolyte and individual sheets of the silicate mineral hectorite has allowed controlled, stepwise formation of multilayered films on silicon wafers. Each component adsorbs rapidly by an ion-exchange mechanism, and x-ray diffractometry indicates structural order even in films with thicknesses greater than 0.2 micrometer. The large lateral extent of the silicate sheets (about 25 to 35 nanometers) allows each layer to cover any packing defects in the underlying layer, thus preserving structural order in the growing film. With careful choice of component materials, this method should allow for the preparation of multilayered films with a variety of technologically important properties.     

A selective activity-dependent requirement for dynamin 1 in synaptic vesicle endocytosis

Dynamin 1 is a neuron-specific guanosine triphosphatase thought to be critically required for the fission reaction of synaptic vesicle endocytosis. Unexpectedly, mice lacking dynamin 1 were able to form functional synapses, even though their postnatal viability was limited. However, during spontaneous network activity, branched, tubular plasma membrane invaginations accumulated, capped by clathrin-coated pits, in synapses of dynamin 1-knockout mice. Synaptic vesicle endocytosis was severely impaired during strong exogenous stimulation but resumed efficiently when the stimulus was terminated. Thus, dynamin 1-independent mechanisms can support limited synaptic vesicle endocytosis, but dynamin 1 is needed during high levels of neuronal activity.     

Ingested RNA interference for managing the populations of the Colorado potato beetle, Leptinotarsa decemlineata

BACKGROUND: RNA interference (RNAi) is a breakthrough technology for conducting functional genomics studies and also as a potential tool for crop protection against insect pests. The major challenge for efficient pest control using RNAi in the field is the development of efficient and reliable methods for production and delivery of double‐stranded RNA (dsRNA). In this paper, the potential of feeding dsRNA expressed in bacteria or synthesized in vitro to manage populations of Colorado potato beetle, Leptinotarsa decemlineata (Say) (CPB), was investigated. RESULTS: Feeding RNAi successfully triggered the silencing of all five target genes tested and caused significant mortality and reduced body weight gain in the treated beetles. This study provides the first example of an effective RNAi response in insects after feeding dsRNA produced in bacteria. CONCLUSION: These results suggest that the efficient induction of RNAi using bacteria to deliver dsRNA is a possible method for management of CPB. This could be also a promising bioassay approach for genome‐wide screens to identify effective target genes for use as novel RNAi‐based insecticides. Copyright © 2010 Society of Chemical Industry