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51.
The objective of this retrospective study is to determine normal reference values for 2-Dimension (2D) and Motion-mode (M-mode) echocardiographic parameters in nonsedated healthy young adult Sphynx cats and to compare them to those of the domestic shorthair (DSH). 131 Sphynx cats underwent cardiac screening prior to breeding. The control group consisted of 30 healthy adult domestic cats. A complete cardiac ultrasound was performed on all cats using right parasternal long and short axis views. There were few echocardiographic parameters in the Sphynx that differed from those of the healthy DSH. Only the left atrial (LA) dimension in 2D and M-mode, the left atrial/aortic (LA/Ao) ratio and the internal dimension of the left ventricle in systole (LVIDs) measured with M-mode were different. In conclusion, although the heart of Sphynx cat can often have a particular 2-D echocardiographic appearance, the M-mode cardiac dimensions are similar to those of the DSH. 相似文献
52.
53.
Pedunculate (Quercus robur L.) and sessile oak (Quercus petreae Matt. Liebl.) are closely related species with a widely sympatric distribution in Europe. These two oak species are also known to display different ecological features, particularly related to their adaptation to soil waterlogging. Pedunculate oak grows in humid areas and can withstand high moisture content of the soil, whereas sessile oak requires drier soil with better drainage. The main goal of this study was to explore the role of gene expression contributing to differences in terms of waterlogging tolerance between these two species. We implemented a series of experiments aimed at evaluating whether differentially expressed genes between species are associated with their ecological preferences and underlie adaptive genetic divergence. Rooted cuttings of both species were grown in hydroponic conditions and subjected to gradual root hypoxia. White roots were sampled after 6, 12, 24 and 48 h. Real-time polymerase chain reaction (qPCR) was first used to monitor the expression of 10 known waterlogging-responsive genes, to identify discriminating sampling time points along the kinetics of hypoxia. Secondly, four subtractive suppressive hybridization libraries (sessile vs. pedunculate, pedunculate vs. sessile for early and late responses) were generated to isolate differentially expressed genes between species. A total of 2160 high-quality expressed sequence tags were obtained and annotated, and a subset of 45 genes were selected for qPCR analysis in a second independent factorial experimental design applying two stress durations per two species. Significant differences of gene expression between pedunculate and sessile oaks were detected, suggesting species-specific molecular strategies to respond to hypoxia. This study revealed that the ability of pedunculate oak to maintain glycolysis and fermentation under hypoxic conditions may help explain its tolerance to waterlogging. 相似文献
54.
Defoliation by processionary moth significantly reduces tree growth: a quantitative review 总被引:1,自引:0,他引:1
? Context
Forests are important carbon sinks, but increasing temperatures may favour increases in insect populations, resulting in greater damage to trees. This, in turn, would lead to lower levels of carbon sequestration, intensifying global warming.? Aim
It is therefore important to predict the impact of insect defoliation on tree growth accurately. The main insect defoliators of conifers in Southern Europe and North Africa are pine and cedar processionary moths (Lepidoptera, Thaumetopoeidae).? Method
We conducted a meta-analysis based on 45 study cases, to estimate the effect of processionary moth defoliation on tree growth.? Result
Overall, processionary moth defoliation had a significant impact on tree growth, regardless of the tree and moth species considered. Mean relative tree growth loss increased with the rate of defoliation levelling out at ca. 50?%; it was significantly larger for young than for old trees.? Conclusion
These results suggest that estimates of processionary moth defoliation could easily be incorporated into tree growth models, to predict the effect of processionary moth outbreaks on carbon sequestration in Mediterranean forests. 相似文献55.
David Da Silva Philippe Balandier Frédéric Boudon André Marquier Christophe Godin 《Annals of Forest Science》2012,69(2):181-193
• Context
Light availability in forest understory is essential for many processes; it is, therefore, a valuable information regarding forest management. However, its estimation is often difficult and direct measurements are tedious. Models can be used to compute understory light, but they often require a lot of field data to accurately predict light distribution, particularly in the case of heterogeneous canopies. 相似文献56.
Valerie Van Craeyveld Emmie Dornez Ulla Holopainen Emilia Selinheimo Kaisa Poutanen Jan A. Delcour Christophe M. Courtin 《Cereal Chemistry》2010,87(4):283-291
Wheat bran‐derived arabinoxylan‐oligosaccharides (AXOS) recently have been shown to potentially exert prebiotic effects. In this study, 15 bran samples obtained by milling different wheat cultivars were treated with xylanases from Hypocrea jecorina (XHJ), Aspergillus aculeatus (XAA), and Pseudoalteromonas haloplanktis (XPH) to assess the effect of bran source and xylanase properties on the AXOS yield and structure. The total arabinoxylan (AX) extraction yield was higher with XHJ (8.2–10.7%) and XAA (8.2–10.8%) than with XPH (6.9–9.5%). Irrespective of the enzyme, a significant negative correlation was observed between extraction yield and arabinose to xylose (A/X) ratio of bran AX (r = –0.7), but not between yield and bran AX level. The A/X ratio of the extracted material was 0.27–0.34 for all bran samples and all enzymes, which combined with yield data and microscopic analysis, indicated primary hydrolysis of aleurone and nucellar epidermis AX. The average degree of polymerization (avDP) of the extracted AX was very low for all enzymes (2–3), owing to the release of high levels of monomeric arabinose and xylose. The release of these monosaccharides could be ascribed to 1) the activity of wheat bran‐associated enzymes (arabinofuranosidases and xylosidases); 2) the hydrolytic properties of the xylanases themselves; and 3) the presence of xylosidases as contaminations in enzyme preparation, in that order of importance. Heat treatment of bran before xylanase treatment significantly decreased the levels of monomeric arabinose and xylose in the extract, without affecting the extraction yield, resulting in a higher avDP of 3–7, thus yielding true AXOS. Overall, for AXOS production, wheat cultivars with a low bran A/X ratio of the AX are preferable as starting materials, and inactivation of bran‐associated enzymes before incubation is desirable. The XHJ xylanase was the best enzyme for wheat bran‐derived AXOS production. 相似文献
57.
Paulo VM Steagall Ludovic Pelligand Tatiana Giordano Christophe Auberger John W Sear Stelio PL Luna Polly M Taylor 《Veterinary anaesthesia and analgesia》2013,40(1):83-95
ObjectiveTo describe simultaneous pharmacokinetics (PK) and thermal antinociception after intravenous (IV), intramuscular (IM) and subcutaneous (SC) buprenorphine in cats.Study designRandomized, prospective, blinded, three period crossover experiment.AnimalsSix healthy adult cats weighing 4.1 ± 0.5 kg.MethodsBuprenorphine (0.02 mg kg?1) was administered IV, IM or SC. Thermal threshold (TT) testing and blood collection were conducted simultaneously at baseline and at predetermined time points up to 24 hours after administration. Buprenorphine plasma concentrations were determined by liquid chromatography tandem mass spectrometry. TT was analyzed using anova (p < 0.05). A pharmacokinetic-pharmacodynamic (PK-PD) model of the IV data was described using a model combining biophase equilibration and receptor association-dissociation kinetics.ResultsTT increased above baseline from 15 to 480 minutes and at 30 and 60 minutes after IV and IM administration, respectively (p < 0.05). Maximum increase in TT (mean ± SD) was 9.3 ± 4.9 °C at 60 minutes (IV), 4.6 ± 2.8 °C at 45 minutes (IM) and 1.9 ± 1.9 °C at 60 minutes (SC). TT was significantly higher at 15, 60, 120 and 180 minutes, and at 15, 30, 45, 60 and 120 minutes after IV administration compared to IM and SC, respectively. IV and IM buprenorphine concentration-time data decreased curvilinearly. SC PK could not be modeled due to erratic absorption and disposition. IV buprenorphine disposition was similar to published data. The PK-PD model showed an onset delay mainly attributable to slow biophase equilibration (t1/2ke0 = 47.4 minutes) and receptor binding (kon = 0.011 mL ng?1 minute?1). Persistence of thermal antinociception was due to slow receptor dissociation (t1/2koff = 18.2 minutes).Conclusions and clinical relevanceIV and IM data followed classical disposition and elimination in most cats. Plasma concentrations after IV administration were associated with antinociceptive effect in a PK-PD model including negative hysteresis. At the doses administered, the IV route should be preferred over the IM and SC routes when buprenorphine is administered to cats. 相似文献
58.
A.T. Lombard 《African Zoology》2013,48(3):145-163
South Africa urgently requires a national strategic plan for the conservation of the country's biodiversity. The formulation of such a plan would be relatively easy if centres (hotspots) of richness, endemism and rarity were congruent, both within and among many different taxa, if these hotspots captured a large proportion of the total species, and if hotspots fell within existing reserves. The investigation of six vertebrate taxa (vizfreshwater fish, frogs, tortoises and terrapins, snakes, birds, and various mammal orders) at a national scale reveals that hotspots are not coincident within taxa. Centres of richness are concentrated in the north-eastern areas of the country, whereas endemism is concentrated in the south-west, and centres of rare and threatened {Red Data Book) species can be in either area. Paired comparisons among taxa reveal greatly varying proportional overlaps of species richness hotspots (0-72%). The proportion of total species falling in hotspots ranges from low (66% for fish) to high (92% for birds). Hotspots are thus not an efficient method of siting representative (ideal) reserves. In order to design a more representative reserve system to protect all vertebrate species, a complementarity algorithm was applied to all taxa separately, and then to all taxa combined. The combined analysis yielded more efficient results {66 reserves are required to represent all 1074 species at least once) than the separate analyses (97 reserves). Many of these representative reserves coincide with both hotspots and existing reserves, and over 85% of the hotspots of most taxa coincide with existing reserves, thus South Africa's vertebrate fauna could be more effectively protected with only moderate acquisition of new, well-sited reserves. A biome analysis reveals that these reserves will also have to incorporate areas of those biomes that are currently inadequately protected, viz grassland, Succulent Karoo and Nama-Karoo. The methods outlined in this paper should be applied to as many other taxa as possible, in order to aid the formulation of a national strategic plan for biodiversity conservation. 相似文献
59.
The combined fish collection databases of the Albany Museum and the J.L.B. Smith Institute of Ichthyology are used to identify hotspots of endemism and threatened fish distributions in South Africa. Hotspots of fish species richness occur in the north-eastern lowveld sectors of South Africa and along the ecotone between the tropical/ subtropical and temperate faunal zones. Hotspots of endemic fish richness occur within both the tropical and temperate faunal regions, notably in the Olifants River system, Western Cape and in areas of high relief such as the Cape Fold Mountains, the Amatola-Wrnterberg (Eastern Cape), and the Drakensberg Escarpment {Kwazulu/ Natal-Eastern Transvaal). Threatened taxa are concentrated in the hotspots of endemic species richness which coincide largely with areas of major river conservation concern. There is limited scope for fish conservation within the ambit of formal (or informal) declared reserves, and the survival of the fauna depends on the success of river catchment conservation management. The value of museum collections in identifying areas of conservation concern for freshwater fishes is emphasized, and highlights the importance of well-preserved voucher specimens for biodiversity conservation. 相似文献
60.
Atle V. Meling Domke Christophe Chartier Bjørn Gjerde Nils Leine Synnøve Vatn Snorre Stuen 《Veterinary parasitology》2013
The present study describes the occurrence of various gastrointestinal helminths, lungworms and liver flukes in Norwegian sheep and goats as assessed from faecal samples and post mortem examinations performed between 2007 and 2010. Faecal samples for gastrointestinal nematode egg counts were collected from 77 sheep flocks and 30 dairy goat flocks from three geographical regions in Norway. Additionally, thirty-two lambs and 16 adult goats were euthanized for necropsy examination and for identification of adult gastrointestinal nematodes and tapeworms, lungworms and liver flukes. The survey showed that there was a higher mean excretion of trichostrongyle eggs in sheep than in goats at the individual level (392 EPG vs. 154 EPG, p < 0.001). For both host species, the mean prevalence and intensity of excreted trichostrongyle eggs were significantly higher in the southern coastal region compared with the inland and northern regions (p < 0.001). Third stage larvae of Trichostrongylus/Teladorsagia, Haemonchus and Nematodirus type were the most prevalent ones in the coprocultures from sheep, whereas larvae of Trichostrongylus/Teladorsagia and Nematodirus type dominated in goats. The most prevalent gastrointestinal nematode species found at necropsy was Teladorsagia circumcincta (75.0 and 81.2% respectively in sheep and goats), while the largest mean worm burdens were recorded for Haemonchus contortus in sheep (724 ± 623) and T. circumcincta in goats (377 ± 529). Other gastrointestinal nematode species were present at low prevalence or in low numbers. 相似文献