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A community's abilities to promote health and maximize its response to public health threats require fulfillment of one of the four elements of public health legal preparedness, the capacity to effectively coordinate law-based efforts across different governmental jurisdictions, as well as across multiple sectors and disciplines. Government jurisdictions can be viewed “vertically” in that response efforts may entail coordination in the application of laws across multiple levels, including local, state, tribal, and federal governments, and even with international organizations. Coordination of legal responses to public health emergencies also may involve a horizontal dimension comprising numerous and diverse sectors, such as public health, public and private health care, emergency management, education, law enforcement, the judiciary, and the military.
Although responses to many acute health threats can implicate multiple jurisdictions and sectors, the jurisdictional and sectoral dimensions of legal preparedness are complex and may vary substantially by the nature of a threat, its geographic and geopolitical extent, and the operational response demanded.
To determine the relative quantities of two hepatotoxic pyrrolizidine alkaloids, symphytine and echimidine, in teas prepared from comfrey leaves (Symphytum officinale), and to determine the potential contribution of the N-oxide forms of these alkaloids to levels of the parent alkaloids.
Comfrey leaves were purchased from three commercial sources and used to prepare tea in a manner consistent with the methods used by consumers. An extraction scheme was devised for extraction of the alkaloids, and a gas chromatographic method was developed to quantify the two major alkaloids, symphytine and echimidine. Recognising that the N-oxide derivatives of these alkaloids have also been identified in comfrey preparations, chemical reduction was applied to determine the total quantities of the alkaloids as free bases and as N-oxide derivatives.
The concentration of symphytine and echimidine varied considerably between teas prepared from leaves purchased from the different vendors of plant material. Moreover, a much higher concentration of symphytine was found in the tea when steps were included to reduce N-oxides prior to analysis. The treatment of pure symphytine with hot water did not generate the N-oxide derivative de novo.
Since the pyrrolizidine alkaloids are known to be hepatotoxic, consumption of herbal teas made from comfrey leaves may be ill-advised. The concentration of pyrrolizidine alkaloids in such teas may be underestimated substantially unless the concentration of N-oxides is taken into consideration.
Molecular analyses based on plasmid profile typing and pulsed-field gel electrophoresis have defined a strain of Salmonella enterica serotype Anatum associated with the consumption of a particular brand of formula-dried milk responsible for an outbreak in late 1996/early 1997 involving 15 infants and 2 relatives in the UK, and 2 infants in France. The study has demonstrated the value of laboratory-based surveillance involving identification of the outbreak strain at the molecular level coupled with food microbiology and targeted epidemiological investigations, and has highlighted the importance of rapid communication and subsequent international collaboration through the European Union-funded Salm-Net salmonella surveillance network.
Field studies conducted at six locations in Georgia and one location in Virginia evaluated imazethapyr and imazethapyr mixtures for weed control, crop tolerance, and peanut yield. Imazethapyr applied early postemergence controlled bristly starbur, coffee senna, common cocklebur, Ipomoea species, jimsonweed, prickly sida, and smallflower morningglory at least 91% and controlled yellow and purple nutsedge 88 and 98%, respectively. Paraquat plus bentazon applied early postemergence did not control the aforementioned weeds as well as imazethapyr or imazethapyr mixtures. Paraquat applied with imazethapyr reduced bristly starbur control 15% compared to imazethapyr alone but did not influence control of the other species. Imazethapyr control of bristly starbur was not improved by the addition of bentazon. Sicklepod control was less than 24% with imazethapyr and was at least 58% with imazethapyr plus paraquat Imazethapyr plus paraquat controlled sicklepod better than paraquat plus bentazon at three of the four locations evaluated. Imazethapyr did not control Florida beggarweed, while imazethapyr plus paraquat controlled at least 53%. Peanut injury was minimal 30 d after application for all treatments.
Polyphenylene oxide (PPO) films have been investigated as protective coatings and as selective inhibitors to permeants.1,2,3 These films have been shown to be passivating materials and therefore are potentially interesting for a variety of applications. It is important for further applications to be able to measure the thickness of thin films by nondestructive techniques, which is the subject of this report. In this study PPO films of various thicknesses were electrodeposited on highly oriented pyrolytic graphite (HOPG) electrodes and examined by spectroscopic ellipsometry (SE) and atomic force microscopy (AFM). These techniques are combined to yield the thickness of the polymer film and the optical properties of the HOPG substrate and the PPO overlayer in the visible and near ultraviolet spectral region.
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