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81.
Q fever, caused by Coxiella burnetii, is a serious zoonotic disease in humans with a worldwide distribution. Many species of animals are capable of transmitting C. burnetii, and consequently all veterinary workers are at risk for this disease. An effective Q fever vaccine has been readily available and used in Australia for many years in at-risk groups, and the European Centre for Disease Prevention and Control has recently also called for the use of this vaccine among at-risk groups in Europe. Little is known about attitudes towards this vaccine and vaccine uptake in veterinary workers. This study aimed to determine the Q fever vaccination status of veterinarians and veterinary nurses in Australia and to assess and compare the knowledge and attitudes towards Q fever disease and vaccination of each cohort. An online cross-sectional survey performed in 2014 targeted all veterinarians and veterinary nurses in Australia. Responses from 890 veterinarians and 852 veterinary nurses were obtained. Binary, ordinal and multinomial logistic regression were used to make comparisons between the two cohorts. The results showed that 74% of veterinarians had sought vaccination compared to only 29% of veterinary nurses. Barriers to vaccination among those not vaccinated did not differ between cohorts, and included a lack of perceived risk, financial expense, time constraints, and difficulty in finding a vaccine provider. Poor knowledge and awareness of Q fever disease and vaccination were additional and notable barriers for the veterinary nursing cohort, suggesting veterinary clinics and veterinarians may not be meeting their legal responsibility to educate staff about risks and risk prevention. Further evaluation is needed to identify the drivers behind seeking and recommending vaccination so that recommendations can be made to improve vaccine uptake.  相似文献   
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Scrutiny of food packaging environmental impacts has led to a variety of sustainability directives, but has largely focused on the direct impacts of materials. A growing awareness of the impacts of food waste warrants a recalibration of packaging environmental assessment to include the indirect effects due to influences on food waste. In this study, we model 13 food products and their typical packaging formats through a consistent life cycle assessment framework in order to demonstrate the effect of food waste on overall system greenhouse gas (GHG) emissions and cumulative energy demand (CED). Starting with food waste rate estimates from the U.S. Department of Agriculture, we calculate the effect on GHG emissions and CED of a hypothetical 10% decrease in food waste rate. This defines a limit for increases in packaging impacts from innovative packaging solutions that will still lead to net system environmental benefits. The ratio of food production to packaging production environmental impact provides a guide to predicting food waste effects on system performance. Based on a survey of the food LCA literature, this ratio for GHG emissions ranges from 0.06 (wine example) to 780 (beef example). High ratios with foods such as cereals, dairy, seafood, and meats suggest greater opportunity for net impact reductions through packaging‐based food waste reduction innovations. While this study is not intended to provide definitive LCAs for the product/package systems modeled, it does illustrate both the importance of considering food waste when comparing packaging alternatives, and the potential for using packaging to reduce overall system impacts by reducing food waste.  相似文献   
84.
The first step in phage infection is the recognition of, and adsorption to, a receptor located on the host cell surface. This reversible host adsorption step is commonly followed by an irreversible event, which involves phage DNA delivery or release into the bacterial cytoplasm. The molecular components that trigger this latter event are unknown for most phages of Gram-positive bacteria. In the current study, we present a comparative genome analysis of three mutants of Lactococcus cremoris 3107, which are resistant to the P335 group phage TP901-1 due to mutations that affect TP901-1 DNA release. Through genetic complementation and phage infection assays, a predicted lactococcal three-component glycosylation system (TGS) was shown to be required for TP901-1 infection. Major cell wall saccharidic components were analysed, but no differences were found. However, heterologous gene expression experiments indicate that this TGS is involved in the glucosylation of a cell envelope-associated component that triggers TP901-1 DNA release. To date, a saccharide modification has not been implicated in the DNA delivery process of a Gram-positive infecting phage.  相似文献   
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In this communication, we describe the isolation of a Lactobacillus delbrueckii subsp. bulgaricus 92063 mutant strain named pH-P11, which differed from the parent strain by low proteolytic activity and altered regulation of expression of lacZ in the presence of glucose or lactose. In the presence of lactose, beta-galactosidase activity was approximately twice as high in pH-P11 than in the wild type. pH-P11 exhibited protosymbiosis together with Streptococcus thermophilus. Yoghurt produced with pH-P11 was characterized by low acidity and little post-acidification during storage. The organoleptic properties (absence of bitterness and other off-flavors, weak sourness, and clear yoghurt taste) were those of a typical "yoghurt mild". This mild flavor was achieved at rather high cell counts of lactobacilli even at the end of shelf-life. High cell counts in conjunction with high beta-galactosidase activity make pH-P11 an interesting strain for application in yoghurt especially designed for consumers with lactose malabsorption. In contrast to "yoghurt mild", which is predominantly produced with Lactobacillus acidophilus together with Streptococcus thermophilus, the product obtained by fermentation with pH-P11 and Streptococcus thermophilus concurs with international standards for yoghurt. During frequent sub-culturing, strain pH-P11, which is supposed to differ from the wild type by one or a few so-far-not-characterized mutations, showed sufficient stability for application in industrial production.  相似文献   
87.
A series of experiments has been undertaken to study the phenomenon of band inversion that can occur during the separation of linear double-stranded DNA in agarose gels under constant electric field. We found that there can be a considerable band inversion when the DNA fragments are moving as a single species. When separating mixtures of fragments, as it is usually done in routine experiments, the band inversion effect is strongly reduced. Our data support the assumption that DNA–DNA interactions can play an important role in electrophoretic separations. © 1995 John Wiley & Sons, Inc.  相似文献   
88.
K J Heller  R J Kadner  K Günther 《Gene》1988,64(1):147-153
In cells of Escherichia coli, the function of the tonB gene is needed for energy-dependent transport processes mediated by the outer-membrane receptors for iron siderophore complexes and vitamin B12. The btuB451 mutation has the same effect on vitamin B12 transport as does a tonB mutation. When a btuB451 strain carried a plasmid with the intact tonB gene, partial revertant strains were isolated which had acquired the ability to grow on 5 nM vitamin B12. This suppression activity was associated with the plasmid, suggesting that a mutation within the tonB gene on the plasmid allowed the mutant BtuB receptor to function in the transport of the vitamin. The nucleotide sequence of the entire tonB gene of ten independently isolated suppressing plasmids was determined. Only a single nucleotide change had occurred in each of the cases. The same codon was always affected resulting in the conversion of glutamine-165 to a leucine in seven of the ten isolates and to a lysine in the other three. The phenotype of strains carrying both types of altered tonB genes showed the retention of their function for other TonB-dependent processes in addition to their suppressor properties with respect to the btuB451 mutation. The fact that mutations suppressing the btuB451 mutation occurred in the tonB gene suggests that there is a direct interaction between TonB and TonB-dependent receptors in the outer membrane of E. coli.  相似文献   
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