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排序方式: 共有234条查询结果,搜索用时 15 毫秒
41.
Rolf Frischknecht Peter Fantke Laura Tschümperlin Monia Niero Assumpció Antón Jane Bare Anne-Marie Boulay Francesco Cherubini Michael Z. Hauschild Andrew Henderson Annie Levasseur Thomas E. McKone Ottar Michelsen Llorenç Milà i Canals Stephan Pfister Brad Ridoutt Ralph K. Rosenbaum Francesca Verones Bruce Vigon Olivier Jolliet 《The International Journal of Life Cycle Assessment》2016,21(3):429-442
42.
Bradley G. Ridoutt Stephan Pfister Alessandro Manzardo Jane Bare Anne-Marie Boulay Francesco Cherubini Peter Fantke Rolf Frischknecht Michael Hauschild Andrew Henderson Olivier Jolliet Annie Levasseur Manuele Margni Thomas McKone Ottar Michelsen Llorenç Milà i Canals Girija Page Rana Pant Marco Raugei Serenella Sala Francesca Verones 《The International Journal of Life Cycle Assessment》2016,21(2):276-280
43.
Monitoring on the Lowveld reaches of the Olifants River, Limpopo River System, and its Steelpoort, Blyde, Klaserie and Selati tributaries was initiated in 2009. Analysis of the 2009–2015 data from four Olifants River sites showed deterioration in the river’s ecological condition between where it enters the Lowveld and where it enters the Kruger National Park, with a slight recovery within the Kruger National Park. Physico-chemical, aquatic macroinvertebrate and fish data collected in 2009–2015 at six sites on the Steelpoort, Blyde, Klaserie and Selati tributaries of the Olifants River corroborated the ecological condition of these tributaries. The Selati was the most polluted and was in a critically modified condition, whereas the Klaserie and Steelpoort were in fair condition and the Blyde was in good condition. The Selati appeared to have a significant negative impact on the water quality, macroinvertebrates and fish of the Olifants River within the Kruger National Park. 相似文献
44.
JR Sara SM Marr WJ Smit LJC Erasmus WJ Luus-Powell 《African Journal of Aquatic Science》2017,42(3):287-291
Muscle tissue from 63 Synodontis zambezensis collected bimonthly in 2013 at Flag Boshielo Dam were analysed for metals and metalloids in a desktop human health risk assessment. The Hazard Quotient, based on a weekly meal of 67 g of fish muscle, exceeded the maximum acceptable level of one for lead, cobalt, cadmium, mercury, arsenic and selenium. The concentrations of these elements were higher in 2013 than those recorded in 2009 and 2012 in other fish species from Flag Boshielo Dam and these may pose a long-term health risk if consumed regularly by impoverished rural communities reliant on fish as a source of protein. 相似文献
45.
Laurence Dufourny Anthony Levasseur Martine Migaud Isabelle Callebaut Pierre Pontarotti Benoit Malpaux Philippe Monget 《BMC evolutionary biology》2008,8(1):105
Background
The melatonin receptor subfamily contains three members Mel1a, Mel1b and Mel1c, found in all vertebrates except for Mel1c which is found only in fish, Xenopus species and the chicken. Another receptor, the melatonin related receptor known as GPR50, found exclusively in mammals and later identified as a member of the melatonin receptor subfamily because of its identity to the three melatonin receptors despite its absence of affinity for melatonin. The aim of this study was to describe the evolutionary relationships between GPR50 and the three other members of the melatonin receptor subfamily. 相似文献46.
Transgenic mice, although useful for analyses of gene function, can present unanticipated phenotypic manifestations, including behavioral problems, that may not be directly associated with the gene of interest but rather due to the complex interplay inherent in genomes. These unexpected events can present unique insight into gene function, leading to an advantage in some situations, yet in others can confound interpretation and compromise usefulness of the transgenic line. Here we document that short-term supplementation with S-adenosyl methionine (SAM)—a nutriceutical known to regulate neurotransmitter levels, improve working memory, and reduce aggression—reduced handling- and startling-induced seizures that otherwise precluded behavioral analyses in a transgenic line. This effect lasted for at least 1 mo after withdrawal of SAM and allowed mice to be used in standard maze analyses. These findings suggest that short-term administration of a neurotropic nutriceutical may provide a functional rescue for behavioral studies in an otherwise intractable transgenic mouse line as well as improve the welfare of similar lines.Abbreviations: SAH, S-adenosyl homocysteine; SAM, S-adenosyl methionineSite-directed mutagenesis, gene deletion, and the insertion of exogenous genes present powerful tools for genetic analyses. Incorporation of such genetic alterations into the murine germline, and the resultant generation of transgenic strains of mice, has provided novel insight into the roles of genes, and their interaction with other genes, at all stages of life. However, transgenic mice can present unanticipated behavioral problems that may not be associated directly with the gene of interest but rather are due to the complex interplay inherent in genomes.20 This unexpected outcome can present unique insight into gene function, leading to an advantage in some situations, yet in others can confound interpretation and compromise usefulness of the transgenic line. Genetic variability of inbred strains can confound interpretation of behavior,18 especially if behavioral analyses are part of the regimen to be studied.26The presence of 1 or more ApoE4 alleles is associated with an increased risk of Alzheimer disease.13 Transgenic mice in which the single murine ApoE allele has been ablated and replaced with human apolipoprotein E isoforms have been useful models for studying the impact of ApoE on age-related cognitive decline and Alzheimer disease. In addition to impaired cognition, mice lacking murine ApoE and expressing human ApoE4 (ApoE4 mice) display increased aggression as compared with normal mice, mice lacking murine ApoE, or mice lacking murine ApoE and expressing other human ApoE alleles.5,6 These behavioral manifestations of ApoE4 mice are useful in that Alzheimer disease is often accompanied by behavioral trauma, including pyschosis and agitation,7 and ApoE4 has been associated with an increase psychotic symptoms in humans.27Recent shipments of ApoE4 mice displayed violent spontaneous and handling-induced convulsions (hereafter referred to as seizures for the sake of simplicity), which included jumping and eventual prostration due to overt exhaustion. These seizures occurred regardless of how quietly or slowly the handler or caregiver moved. These seizures, which persisted for more than 1 mo, had not previously been observed in ApoE4 mice or other mice in our facility and precluded the intended use of the ApoE4 mice in standard maze trials.5In our ongoing studies, we had observed that dietary supplementation with the nutriceutical S-adenosyl methionine (SAM) reduced aggressive behavior in ApoE4 mice.5 SAM also restores neurotransmitter balance, increases working memory, and modulates neuronal activity.6,8,17,19 We therefore hypothesized that SAM supplementation would reduce or alleviate handling-induced seizures. Here we document that short-term administration of SAM reduced of seizures for extended periods, to the extent that these mice could be used in behavioral studies. We discuss the possibility that such an approach may be useful for habituation of other mouse lines displaying similar behavior difficulties. 相似文献
47.
48.
Gui-Peng Yang Maurice Levasseur Sonia Michaud Anissa Merzouk Martine Lizotte Michael Scarratt 《Biogeochemistry》2009,94(3):243-254
One of the key steps towards predicting dimethylsulfide (DMS) emission to the atmosphere is to understand the distribution
and cycling of biogenic sulfur in the microlayer. In this study, we examined the distribution of DMS and dissolved and particulate
fractions of dimethylsulfoniopropionate (DMSPd and DMSPp) in the surface microlayer and bulk water of the western North Atlantic
during July 2003. DMS concentrations in the bulk water varied from 0.71 to 7.65 nM. In contrast, DMS concentrations in the
surface microlayer were fairly low (0.17–1.33 nM). Average concentrations of DMSPd and DMSPp in the bulk water were 2.09 (1.87–6.25)
and 44.1 (8.06–119.8) nM, respectively, and those in the surface microlayer were 15.4 (4.06–54.3) and 29.9 (7.32–97.0) nM.
In general, DMS was depleted in the microlayer (mean concentration: 0.60 nM) relative to the bulk water (mean concentration:
2.38 nM) with enrichment factors (the ratio of the microlayer concentration to bulk water concentration) ranging from 0.13
to 0.54. There was no consistent enrichment of DMSPp and chlorophyll a in the microlayer. On the contrary, DMSPd appeared to be highly enriched in the microlayer with an average EF of 4.89. The
concentration of phaeopigments was also generally greater in the microlayer than in the bulk water, presumably due to enhanced
photo-oxidation of chlorophyll a under high surface light intensities in the microlayer. In the study area, the concentration of DMSPp was significantly correlated
with the abundance of dinoflagellates in the microlayer. Moreover, a significant correlation between the distributions of
DMS, DMSPp, chlorophyll a and phaeopigment concentrations in the microlayer and the bulk water demonstrated that the biogenic materials in the microlayer
come primarily from the bulk water below. 相似文献
49.
50.
Frank Bedon Caroline Levasseur Jacqueline Grima-Pettenati Armand Séguin John MacKay 《Plant cell reports》2009,28(5):787-800
The enzyme Cinnamyl
Alcohol
Dehydrogenase (CAD) catalyses the last step of lignin monomer synthesis, and is considered as a molecular marker of cell wall lignification
in different plants species. Here, we report the isolation and analysis of 5′ flanking genomic DNA regions upstream to the
CAD gene, from two conifers, i.e. white spruce (Picea
glauca (Moench) Voss) and loblolly pine (Pinus
taeda L.). Sequence comparisons with available CAD gene promoters from angiosperms highlighted the conservation of cis-elements matching MYB, WRKY and bHLH binding sites. Functional characterization of the P.
glauca
CAD promoter used P.
glauca seedlings stably transformed with a DNA fragment of 1,163 base pairs (PgCAD) fused to the β-glucuronidase (GUS) gene. Histochemical observations of different vegetative organs of the transgenic trees showed that this sequence was sufficient
to drive GUS expression in lignifying tissues, and more specifically in differentiating xylem cells. Quantitative RT-PCR experiments
also indicated that the native CAD gene was preferentially expressed in differentiating xylem both in stems and roots. In addition, GUS expression driven by
the PgCAD promoter was wound-inducible which was consistent with the accumulation of CAD mRNA in response to jasmonate application and mechanical wounding. The spruce CAD promoter represents a valuable tool for research and biotechnology applications related to xylem and wood.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献