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981.
Lynn V. Dicks Hugh L. Wright Joscelyne E. Ashpole James Hutchison Caitlin G. McCormack Barbara Livoreil Klaus Peter Zulka William J. Sutherland 《Biodiversity and Conservation》2016,25(7):1383-1399
This paper documents an exercise to synthesize and assess the best available scientific knowledge on the effectiveness of different farm practices at enhancing natural pest regulation in agriculture. It demonstrates a novel combination of three approaches to evidence synthesis—systematic literature search, collated synopsis and evidence assessment using an expert panel. These approaches follow a logical sequence moving from a large volume of disparate evidence to a simple, easily understandable answer for use in policy or practice. The example of natural pest regulation in agriculture was selected as a case study within two independent science-policy interface projects, one European and one British. A third funder, a private business, supported the final stage to translate the synthesized findings into a useful, simplified output for agronomists. As a whole, the case study showcases how a network of scientific knowledge holders and knowledge users can work together to improve the use of science in policy and practice. The process identified five practices with good evidence of a benefit to natural pest regulation, with the most beneficial being ‘Combine trap and repellent crops in a push–pull system’. It highlights knowledge gaps, or potential research priorities, by showing practices considered important by stakeholders for which there is not enough evidence to make an assessment of effects on natural pest regulation, including ‘Alter the timing of pesticide application.’ Finally, the process identifies several important practices where the volume of evidence of effects on natural pest regulation was too large (>300 experimental studies) to be summarised with the resources available, and for which focused systematic reviews may be the best approach. These very well studied practices include ‘Reduce tillage’ and ‘Plant more than one crop per field’. 相似文献
982.
Metal ionophores are considered as potential anti-dementia agents, and some are currently undergoing clinical trials. Many metals are known to accumulate and distribute abnormally in the aging brain. Alterations in zinc metal homeostasis in the glutaminergic synapse could contribute to ageing and the pathophysiology of Alzheimer’s disease (AD). The present study was designed to investigate the effect of metal ionophores on long term administration of zinc in D-galactose induced senescent mice. The ageing model was established by combined administration of zinc and D-galactose to mice for 6 weeks. A novel metal ionophore, PBT-2 was given daily to zinc-induced d-galactose senescent mice. The cognitive behaviour of mice was monitored using the Morris Water Maze. The anti-oxidant status and amyloidogenic activity in the ageing mouse was measured by determining mito-oxidative parameters and deposition of amyloid β (Aβ) in the brain. Systemic administration of both zinc and D-galactose significantly produced memory deficits, mito-oxidative damage, heightened acetylcholinesterase enzymatic activity and deposition of amyloid-β. Treatment with PBT-2 significantly improved behavioural deficits, biochemical profiles, cellular damage, and curbed the deposition of APP in zinc-induced senescent mice. These findings suggest that PBT-2, acting as a metal protein attenuating compound, may be helpful in the prevention of AD or alleviation of ageing. 相似文献
983.
Siderophores are structurally diverse, complex natural products that bind metals with extraordinary specificity and affinity. The acquisition of iron is critical for the survival and virulence of many pathogenic microbes and diverse strategies have evolved to synthesize, import and utilize iron. There has been a substantial increase of known siderophore scaffolds isolated and characterized in the past decade and the corresponding biosynthetic gene clusters have provided insight into the varied pathways involved in siderophore biosynthesis, delivery and utilization. Additionally, therapeutic applications of siderophores and related compounds are actively being developed. The study of biosynthetic pathways to natural siderophores augments the understanding of the complex mechanisms of bacterial iron acquisition, and enables a complimentary approach to address virulence through the interruption of siderophore biosynthesis or utilization by targeting the key enzymes to the siderophore pathways. 相似文献
984.
Andrew J. Ghio 《Biometals》2016,29(5):751-779
Over several decades, asthma has evolved from being recognized as a single disease to include a diverse group of phenotypes with dissimilar natural histories, pathophysiologies, responses to treatment, and distinctive molecular pathways. With the application of Occam’s razor to asthma, it is proposed that there is one cause underlying the numerous phenotypes of this disease and that the responsible molecular pathway is a deficiency of iron in the lung tissues. This deficiency can be either absolute (e.g. asthma in the neonate and during both pregnancy and menstruation) or functional (e.g. asthma associated with infections, smoking, and obesity). Comparable associations between asthma co-morbidity (e.g. eczema, urticaria, restless leg syndrome, and pulmonary hypertension) with iron deficiency support such a shared mechanistic pathway. Therapies directed at asthma demonstrate a capacity to impact iron homeostasis, further strengthening the relationship. Finally, pathophysiologic events producing asthma, including inflammation, increases in Th2 cells, and muscle contraction, can correlate with iron availability. Recognition of a potential association between asthma and an absolute and/or functional iron deficiency suggests specific therapeutic interventions including inhaled iron. 相似文献
985.
This article explores responses to the implementation of Russian sturgeon conservation policy in three fishing communities (in Dagestan, Kalmykia and the Volga River delta areas), along the Western and Northern coasts of the Caspian Sea. Enforcement of regulatory measures has led to complex socio-cultural responses. We show how social responses to conservation policy generate various forms of poaching. An analytical model of ‘soft’ and ‘hard’ forms of poaching is analyzed against three regulatory measures: introduction of specially designated fishing areas in Russia’s Caspian fisheries, border zone expansion and the ban on sturgeon fishing. We explain why in Kalmykia the policy led people to stop practicing hard forms of sturgeon fishing, while fishermen in Dagestan responded in a more complex manner by displaying resistance towards the new policies. 相似文献
986.
987.
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989.
Rui-Cin Lyu Hui-Yu Hu Lih-Ying Kuo Huei-Fen Lo Ping-Lin Ong Hui-Ping Chang Long-Liu Lin 《Current microbiology》2009,59(2):101-106
Role of the conserved Thr399 and Thr417 residues of Bacillus licheniformis γ-glutamyltranspeptidase (BlGGT) was investigated by site-directed mutagenesis. Substitutions of Thr399 and Thr417 of BlGGT with Ser resulted in a dramatic reduction in enzymatic activity. A complete loss of the GGT activity was observed in T399A,
T399C, T417A, and T417K mutant enzymes. Furthermore, mutations on these two residues impaired the capability of autocatalytic
processing of the enzyme. In vitro maturation experiments showed that BlGGT mutant precursors, pro-T399S, pro-T417S, and pro-T417A, could precede a time-dependent autocatalytic process to generate
the 44.9- and 21.7-kDa subunits; however, the processed T417A had no enzymatic activity. Measurement of intrinsic tryptophan
fluorescence revealed alteration of the microenvironment of aromatic amino acid residues, while Far-UV circular dichroism
spectra were nearly identical for wild-type and mutant enzymes. These results suggest that residues Thr399 and Thr417 are
important for BlGGT in the enzymatic maturation and reaction.
An erratum to this article can be found at 相似文献
990.
Zhuang Kang Jia-hong Jiang Dong Wang Ke Liu Lin-fang Du 《Biochemistry. Biokhimii?a》2009,74(1):102-109
The trypsin inhibitor SOTI was isolated from Spinacia oleracea L. seeds through ammonium sulfate precipitation, Sepharose 4B-trypsin affinity chromatography, and Sephadex G-75 chromatography.
This typical Kunitz inhibitor showed remarkable stability to heat, pH, and denaturant. It retained 80% of its activity against
trypsin after boiling for 20 min, and more than 90% activity when treated with 6 M guanidine hydrochloride. The formation
of stable SOTI-trypsin complex (K
i
= 2.3·10−6 M) is consistent with significant inhibitory activity of SOTI against trypsin-like proteinases present in the larval midgut
of Pieris rapae. Sequences of SOTI fragments showed homology with other inhibitors.
Published in Russian in Biokhimiya, 2009, Vol. 74, No. 1, pp. 131–140. 相似文献