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101.
The genetic variability at six cloned minisatellite loci was analyzed in
minke whale populations from the North Atlantic, North Pacific, and
Antarctic Oceans. Three loci displayed only a few different alleles in each
of the three populations, with heterozygosity ranging from 0.00 to 0.47,
and three loci revealed many different alleles in at least two fo the three
populations, with heterozygosity ranging up to 0.98. Using small sample
sizes, samples from two adjacent Antarctic Management Areas were not found
to differ significantly in allele frequencies at any of the six loci. The
use of principal coordinate analysis to detect multilocus disequilibria was
explored. No significant evidence was found of intrapopulation
heterogeneity within the pooled Antarctic sample. Pronounced interoceanic
differences were observed at every locus, confirming the existence of
genetic isolation found earlier using more conventional marker systems. The
populations from the three oceans appear to have diverged to such a degree
that the hypervariable loci have had time to evolve independently and
arrive at different evolutionary stages in different populations. The
frequency of undetected "null" alleles is remarkably high in minke whale
populations compared to human populations and is probably a result of the
cloning protocol used. Minisatellite loci are shown to provide a powerful
population genetic tool, supplying levels of resolution appropriate to
different degrees of evolutionary divergence.
相似文献
102.
Phylogenetics of tribe Sabiceeae (Ixoroideae,Rubiaceae) revisited,with a new subgeneric classification for Sabicea 下载免费PDF全文
Lise Zemagho Sigrid Liede‐Schumann Bonaventure Sonké Steven Janssens Olivier Lachenaud Brecht Verstraete Steven Dessein 《Botanical journal of the Linnean Society. Linnean Society of London》2016,182(3):551-580
Tribe Sabiceeae (Ixoroideae, Rubiaceae) has undergone recent taxonomical changes with the incorporation of the related genera Ecpoma, Pseudosabicea and Stipularia into the type genus Sabicea. We use phylogenetic analysis and morphological data to verify the relationships among members of the tribe, including the most comprehensive taxon sampling of the tribe to date with 74 of 145 species. Sequence data from the nuclear internal transcribed spacer (ITS) and three plastid markers (petD, rps16, trnT–F) were used to infer relationships among the members of the tribe. Individual analyses using maximum likelihood, parsimony and Bayesian approaches reveal several supported clades: the former genus Stipularia is resolved as a monophyletic unit, but Ecpoma is monophyletic only if Sabicea urbaniana and Sabicea xanthotricha are included (corresponding to Sabicea subgenus Stipulariopsis sensu Wernham). Pseudosabicea is biphyletic, with one clade corresponding to section Anisophyllae of Hallé (1964) and the other one to the other sections (Floribundae and Sphaericae) of the genus. Eleven morphological characteristics were recorded for all species studied and seven have been mapped onto the phylogenetic tree to study their evolution in the group and assess their value for the classification of Sabicea s.l. Finally, our study shows that a combination of diagnostic characteristics should be used to differentiate each group and we propose to recognise four subgenera in Sabicea. 相似文献
103.
Rapid leaf development drives the seasonal pattern of volatile organic compound (VOC) fluxes in a ‘coppiced’ bioenergy poplar plantation 下载免费PDF全文
Federico Brilli Beniamino Gioli Silvano Fares Zenone Terenzio Donatella Zona Bert Gielen Francesco Loreto Ivan A. Janssens Reinhart Ceulemans 《Plant, cell & environment》2016,39(3):539-555
Leaves of fast‐growing, woody bioenergy crops often emit volatile organic compounds (VOC). Some reactive VOC (especially isoprene) play a key role in climate forcing and may negatively affect local air quality. We monitored the seasonal exchange of VOC using the eddy covariance technique in a ‘coppiced’ poplar plantation. The complex interactions of VOC fluxes with climatic and physiological variables were also explored by using an artificial neural network (Self Organizing Map). Isoprene and methanol were the most abundant VOC emitted by the plantation. Rapid development of the canopy (and thus of the leaf area index, LAI) was associated with high methanol emissions and high rates of gross primary production (GPP) since the beginning of the growing season, while the onset of isoprene emission was delayed. The highest emissions of isoprene, and of isoprene photo‐oxidation products (Methyl Vinyl Ketone and Methacrolein, iox), occurred on the hottest and sunniest days, when GPP and evapotranspiration were highest, and formaldehyde was significantly deposited. Canopy senescence enhanced the exchange of oxygenated VOC. The accuracy of methanol and isoprene emission simulations with the Model of Emissions of Gases and Aerosols from Nature increased by applying a function to modify their basal emission factors, accounting for seasonality of GPP or LAI. 相似文献
104.
105.
Effect of an oral healthcare protocol in nursing homes on care staffs' knowledge and attitude towards oral health care: a cluster‐randomised controlled trial 下载免费PDF全文
106.
107.
Edgard Azoulay Franoise Jouanneau Jean-Claude Bertrand Alain Raphael Jacques Janssens Jean Michel Lebeault 《Applied microbiology》1980,39(1):41-47
Candida tropicalis grows on soluble starch, corn, and cassava powders without requiring that these substrates be previously hydrolyzed. C. tropicalis possesses the enzyme needed to hydrolyze starch, namely, an α-amylase. That property has been used to develop a fermentation process whereby C. tropicalis can be grown directly on corn or cassava powders so that the resultant mixture of biomass and residual corn or cassava contains about 20% protein, which represents a balanced diet for either animal fodder or human food. The fact that no extra enzymes are required to hydrolyze starch results in a particularly efficient way of improving the nutritional value of amylaceous products, through a single-step fermentation process. 相似文献
108.
Peter A. Janssens Mandy Giuliano 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1989,159(3):323-331
Summary In mammals hepatic glycogenolysis is controlled by several hormones using cyclicAMP, Ca2+ and/or diacylglycerol as intracellular messengers. In contrast, in teleost fish, lungfish and amphibians fewer hormones promote hepatic glycogenolysis, and cyclicAMP is the sole intra-cellular messenger. This suggests that the -adrenergic mechanism became associated with the liver after amphibians separated from the vertebrate line. Reptiles separated later, and the aim of this study is to elucidate the hormonal control of hepatic glycogenolysis in a reptile,Amphibolurus nuchalis, and especially to determine which adrenergic receptor system is operative.InA. nuchalis liver pieces cultured in vitro, adrenaline and glucagon stimulated glycogen breakdown and glucose release, glycogen phosphorylase activity and accumulation of cyclicAMP in the tissue. Neurohypophysial peptides did not affect these parameters. These actions of adrenaline were completely blocked by the -adrenergic antagonist, propranolol and slightly reduced by the -adrenergic antagonist, phentolamine. Removal of Ca2+ from the medium and addition of the Ca2+ chelator, EGTA, did not block the actions of adrenaline, and the Ca2+ ionophore A23187 did not mimic these actions.The -adrenegic ligand [125I]-iodocyanopindolol (ICP) bound specifically to an isolated membrane preparation fromA. nuchalis liver with a calculated KD of 100 pM and a Bmax of 37.6 fmol·mg protein–1. The adrenergic ligands propranolol, isoprenaline, adrenaline, noradrenaline, phenylephrine and phentolamine displaced ICP with KD's of 20 nM, 1 M, 4.5 M, 32 M, 35 M and 500 M, respectively. The 2-adrenergic ligand yohimbine did not bind specifically to the membrane, but at 1 nM and 100 pM, specific binding of the 1-adrenergic ligand prazosin was 45% of total with a mean of 11.3 fmoles·mg protein–1 specifically bound.These findings indicate that the glycogenolytic actions of adrenaline are mediated primarily via -adrenergic receptors inA. nuchalis, but that -adrenergic receptors may also play some role in the control of hepatic metabolism. 相似文献
109.
The Novel Neuropsychotropic Agent Milacemide Is a Specific Enzyme-Activated Inhibitor of Brain Monoamine Oxidase B 总被引:3,自引:0,他引:3
Philippe Janssens de Varebeke Gilbert Pauwels Corinne Buyse Michele David-Remacle Jo De Mey Josd Roba Moussa B. H. Youdim 《Journal of neurochemistry》1989,53(4):1109-1116
The novel neuropsychotropic agent milacemide hydrochloride (2-n-pentylaminoacetamide HCl) is a highly selective substrate of the B form of monoamine oxidase (EC 1.4.3.4; MAO). Under the in vitro conditions used in the present study, milacemide acts as an enzyme-activated, partially reversible inhibitor of MAO-B. A reversible inhibition of MAO-A activity is also observed at high concentrations. The inhibitory activity of milacemide is significantly greater for MAO-B. In vivo, after single or repeated oral administration, a specific inhibition of MAO-B is apparent in brain and liver, with a lack of inhibition of the MAO-A activity. In contrast to the irreversible inhibitory action of L-deprenyl, the recovery of MAO-B activity in vivo after milacemide administration is significantly faster, a result suggesting that it is a partially reversible inhibitor. The selective inhibitory effect of milacemide for MAO-B in vivo is confirmed by its potentiation of phenylethylamine-induced stereotyped behavior, whereas vasopressor responses to tyramine were not affected. These observations suggest that milacemide could enhance dopaminergic activity in the brain and could be used as therapy for Parkinson's disease in association with L-3,4-dihydroxyphenylalanine. 相似文献
110.
Kevin Van Sundert Dajana Radujkovi Nathalie Cools Bruno De Vos Sophia Etzold Marcos Fernndez‐Martínez Ivan A. Janssens Pivi Meril Josep Peuelas Jordi Sardans Johan Stendahl Csar Terrer Sara Vicca 《Global Change Biology》2020,26(2):392-409
Nutrient availability influences virtually every aspect of an ecosystem, and is a critical modifier of ecosystem responses to global change. Although this crucial role of nutrient availability in regulating ecosystem structure and functioning has been widely acknowledged, nutrients are still often neglected in observational and experimental synthesis studies due to difficulties in comparing the nutrient status across sites. In the current study, we explain different nutrient‐related concepts and discuss the potential of soil‐, plant‐ and remote sensing‐based metrics to compare the nutrient status across space. Based on our review and additional analyses on a dataset of European, managed temperate and boreal forests (ICP [International Co‐operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests] Forests dataset), we conclude that the use of plant‐ and remote sensing‐based metrics that rely on tissue stoichiometry is limited due to their strong dependence on species identity. The potential use of other plant‐based metrics such as Ellenberg indicator values and plant‐functional traits is also discussed. We conclude from our analyses and review that soil‐based metrics have the highest potential for successful intersite comparison of the nutrient status. As an example, we used and adjusted a soil‐based metric, previously developed for conifer forests across Sweden, against the same ICP Forests data. We suggest that this adjusted and further adaptable metric, which included the organic carbon concentration in the upper 20 cm of the soil (including the organic fermentation‐humus [FH] layer), the C:N ratio and of the FH layer, can be used as a complementary tool along with other indicators of nutrient availability, to compare the background nutrient status across temperate and boreal forests dominated by spruce, pine or beech. Future collection and provision of harmonized soil data from observational and experimental sites is crucial for further testing and adjusting the metric. 相似文献