排序方式： 共有7条查询结果，搜索用时 15 毫秒
1
1.
Summary Achenes of wild forms of Anemone coronaria growing in Israel differ in their germination requirements from achenes of the cultivated de Caen type. The optimum temperature for dark germination was between 10–15°C in the former and between 15–20°C in the latter. Maximum daily rates of germination were higher, reaching 16% per day, and the minimum lag period between sowing and seedling emergence was shorter in achenes of the cultivated than in those of the wild anemone when the two types were incubated under identical conditions. Wild achenes showed a marked post-harvest maturation requirement, and attained full germination, a minimum pre-emergence lag period after sowing, and a maximum daily germination rate only when dry-stored for several months subsequent to harvesting. In the cultivated plant this requirement was far less pronounced or absent. Most embryos in freshly harvested achenes of both the wild and the cultivated anemone were torpedo-shaped but in the cultivated form embryos were larger. In both types embryos remained unchanged in shape and size during dry storage. 相似文献
2.
Phoberomys is reported to be the largest rodent that ever existed, although it has been known only from isolated teeth and fragmentary postcranial bones. An exceptionally complete skeleton of Phoberomys pattersoni was discovered in a rich locality of fossil vertebrates in the Upper Miocene of Venezuela. Reliable body mass estimates yield approximately 700 kilograms, more than 10 times the mass of the largest living rodent, the capybara. With Phoberomys, Rodentia becomes one of the mammalian orders with the largest size range, second only to diprotodontian marsupials. Several postcranial features support an evolutionary relationship of Phoberomys with pakaranas from the South American rodent radiation. The associated fossil fauna is diverse and suggests that Phoberomys lived in marginal lagoons and wetlands. 相似文献
3.
M. Aktas D. Auguste H. P. Lefebvre P. L. Toutain J. P. Braun 《Veterinary research communications》1993,17(5):353-369
In the dog, creatine kinase (CK) is mostly present in the skeletal muscles, myocardium, brain and intestine. The MM isoenzyme predominates in muscles and myocardium. In plasma, reference values depend on the technique used and CK-MB accounts for about 30–45% of total CK activity. Sex has no influence on plasma CK activity, which is higher in young dogs than in adults. Plasma CK is elevated after physical exercise. After its release from the cells, CK reaches the plasma mostly via the lymphatic route and then remains in the plasma compartment. It is rapidly cleared with a half-life of about 2 hours. Muscle diseases are the main source of plasma CK elevations: inherited myopathies, malignant hyperthermia, hypothyroidism, vitamin E-selenium deficiency, prolonged decubitus, intramuscular injections, surgery, etc. Plasma CK is also increased in experimental myocardial infarction, for which the dog is an interesting model, allowing quantification of the damage by measuring the total CK activity released.Abbreviations ADP
adenosine diphosphate
- ATP
adenosine triphosphate
- CK
creatine kinase
- DGKC
Deutsche Gesellschaft für klinische Chemie
- IM
intramuscular
- IV
intravenous
-
K
m
Michaelis constant
- poly(A)
polyadenylate
- RNA
ribonucleic acid
- mRNA
messenger RNA 相似文献
4.
5.
Vincent P. Medjibe Francis E. PutzMalcolm P. Starkey Auguste A. NdounaHervé R. Memiaghe 《Forest Ecology and Management》2011,262(9):1799-1806
Selective logging is an important socio-economic activity in the Congo Basin but one with associated environmental costs, some of which are avoidable through the use of reduced-impact logging (RIL) practices. With increased global concerns about biodiversity losses and emissions of carbon from forest in the region, more information is needed about the effects of logging on forest structure, composition, and carbon balance. We assessed the consequences of low-intensity RIL on above-ground biomass and tree species richness in a 50 ha area in northwestern Gabon. We assessed logging impacts principally in 10 randomly located 1-ha plots in which all trees ?10 cm dbh were measured, identified to species, marked, and tagged prior to harvesting. After logging, damage to these trees was recorded as being due to felling or skidding (i.e., log yarding) and skid trails were mapped in the entire 50-ha study area. Allometric equations based on tree diameter and wood density were used to transform tree diameter into biomass.Logging was light with only 0.82 trees (8.11 m3) per hectare extracted. For each tree felled, an average of 11 trees ?10 cm dbh suffered crown, bole, or root damage. Skid trails covered 2.8% of the soil surface and skidding logs to the roadside caused damage to an average of 15.6 trees ?10 cm dbh per hectare. No effect of logging was observed on tree species richness and pre-logging above-ground forest biomass (420.4 Mg ha−1) declined by only 8.1% (34.2 Mg ha−1). We conclude from these data that with harvest planning, worker training in RIL techniques, and low logging intensities, substantial carbon stocks and tree species richness were retained in this selectively logged forest in Gabon. 相似文献
6.
A new method is described for eliciting a stable spindle burst response after the production of unilateral lesions in the reticular formation of the cat. This permits quantifying the effects of stimulation of the reticular activating system, either electrically or by injection of epinephrine, on the cortical arousal response. 相似文献
7.
N. N. Thompson A. J. Auguste A. P. A. Travassos da Rosa C. V. F. Carrington B. J. Blitvich D. D. Chadee R. B. Tesh S. C. Weaver A. A. Adesiyun 《Zoonoses and public health》2015,62(1):53-60
A serosurvey of antibodies against selected flaviviruses and alphaviruses in 384 bats (representing 10 genera and 14 species) was conducted in the Caribbean island of Trinidad. Sera were analysed using epitope‐blocking enzyme‐linked immunosorbent assays (ELISAs) specific for antibodies against West Nile virus (WNV), Venezuelan equine encephalitis virus (VEEV) and eastern equine encephalitis virus (EEEV), all of which are zoonotic viruses of public health significance in the region. Overall, the ELISAs resulted in the detection of VEEV‐specific antibodies in 11 (2.9%) of 384 bats. Antibodies to WNV and EEEV were not detected in any sera. Of the 384 sera, 308 were also screened using hemagglutination inhibition assay (HIA) for antibodies to the aforementioned viruses as well as St. Louis encephalitis virus (SLEV; which also causes epidemic disease in humans), Rio Bravo virus (RBV), Tamana bat virus (TABV) and western equine encephalitis virus (WEEV). Using this approach, antibodies to TABV and RBV were detected in 47 (15.3%) and 3 (1.0%) bats, respectively. HIA results also suggest the presence of antibodies to an undetermined flavivirus(es) in 8 (2.6%) bats. Seropositivity for TABV was significantly (P < 0.05; χ2) associated with bat species, location and feeding preference, and for VEEV with roost type and location. Differences in prevalence rates between urban and rural locations were statistically significant (P < 0.05; χ2) for TABV only. None of the aforementioned factors was significantly associated with RBV seropositivity rates. 相似文献
1