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31.
1. Additional straw or grain was supplied to hens during rearing in floor pens with litter floors. During lay, hens were housed in pens with partly-littered partly-slatted floors. The effects on foraging behaviour and feather pecking were studied and feather damage was scored at 17, 30 and 42 weeks of age. 2. Supply of grain in the litter during rearing caused an increase in ground scratching. Ground pecking also tended to increase. Supply of straw had no significant effect on the observed behaviours. 3. Feather damage in the laying period was significantly reduced by providing grain during rearing. A similar tendency was found for groups that received straw during rearing. On the basis of the behavioural observations it was concluded that this better plumage cover was caused by less feather pecking. 4. The frequency of pecking at food was decreased during rearing by the supply of grain. This could not be explained solely on the basis of a lower food intake. Apparently the efficiency of pecking at food had changed as well. Behavioural data from the laying period suggest that this change was of a more permanent character. 5. The incentive value of the ground and the substrate covering it might be increased by the supply of grain during the rearing period. This causes foraging-related behaviours like scratching and pecking to be directed to the ground. The hens' perception of incentive stimuli for pecking is apparently influenced by experience during rearing. 6. To prevent birds redirecting their ground pecks to the feathers of other birds, not only the peckability/scratchability of the ground seems to be important but also other aspects like nutritive value or taste.  相似文献   
32.
Microbial growth in soil is mostly limited by lack of carbon (C). However, adding fresh, C-rich litter can induce nitrogen (N) limitation. We studied the effect of alleviating C and N limitation in high-pH (> 8) soils, soils expected to favor bacterial over fungal growth. Nitrogen limitation was induced by incubating soils amended with C-rich substrate (starch or straw) for 4 weeks. Limiting nutrients and the effects of alleviating limitation were then studied by adding C (as glucose) or N (as NH4NO3) and measuring microbial growth and respiration after 4 d. In non-amended, C-limited soils, adding C but not N increased both microbial respiration and bacterial growth. In N-limited, substrate-amended soils, adding C increased respiration, whereas adding N increased both microbial respiration and growth. Inducing N limitation by amending with straw was most easily detected in increased fungal growth after the addition of N, whereas with starch, only bacterial growth responded to alleviating N limitation. Compared to earlier results using a low-pH soil, the effect of substrate used to induce N limitation was more important than pH for inducing bacterial or fungal growth after alleviating N limitation. Furthermore, we found no evidence that alleviating N limitation resulted in decreased respiration concomitant with increased microbial growth in soil, suggesting no drastic changes in C use efficiency.  相似文献   
33.
A two‐year‐old, female neutered, cross‐breed dog imported from Romania was diagnosed with nasal infestation of Linguatula serrata after she sneezed out an adult female. The dog was presented with mucopurulent/sanguinous nasal discharge, marked left‐sided exophthalmia, conjunctival hyperaemia and chemosis. Computed tomography and left frontal sinusotomy revealed no further evidence of adult parasites. In addition, there was no evidence of egg shedding in the nasal secretions or faeces. Clinical signs resolved within 48 hours of sinusotomy, and with systemic broad‐spectrum antibiotics and non‐steroidal anti‐inflammatory drugs. Recommendations are given in this report regarding the management and follow‐up of this important zoonotic disease.  相似文献   
34.
This study was designed to evaluate effects of different combinations of cryoprotectants on the ability of vitrified immature buffalo oocytes to undergo in vitro maturation. Straw and open‐pulled straw (OPS) methods for vitrification of oocytes at the germinal vesicle stage also were compared. The immature oocytes were harvested from ovaries of slaughtered animals and were divided into three groups: (i) untreated (control); (ii) exposed to cryoprotectant agents (CPAs); or (iii) cryopreserved by straw and OPS vitrification methods. The vitrification solution (VS) consisted of 6 m ethylene glycol (EG) as the standard, control vitrification treatment, and this was compared with 3 m EG + 3 m dimethyl sulfoxide (DMSO), 3 m EG + 3 m glycerol, and 3 m DMSO + 3 m glycerol. Cryoprotectants were added in two steps, with the first step concentration half that of the second (and final) step concentration. After warming, oocyte samples were matured by standard methods and then fixed and stained for nuclear evaluation. Rates of MII oocytes exposed to CPAs without vitrification were lower (54.3 ± 1.9% in EG, 47.5 ± 3.4% in EG + DMSO, 36.8 ± 1.2% in EG + glycerol and 29.9 ± 1.0% in DMSO + glycerol; p < 0.05) than for the control group (79.8 ± 1.3%). For all treatments in each vitrification experiment, results were nearly identical for straws and OPS, so all results presented are the average of these two containers. The percentages of oocytes reaching telophase‐I or metaphase‐II stages were lower in oocytes cryopreserved using all treatments when compared with control. However, among the vitrified oocytes, the highest maturation rate was seen in oocytes vitrified in EG + DMSO (41.5 ± 0.6%). Oocytes cryopreserved in all groups with glycerol had an overall low maturation rate 19.0 ± 0.6% for EG + glycerol and 17.0 ± 1.1% for DMSO + glycerol. We conclude that the function of oocytes was severely affected by both vitrification and exposure to cryoprotectants without vitrification; the best combination of cryoprotectants was EG + DMSO for vitrification of immature buffalo oocytes using either straw or OPS methods.  相似文献   
35.
A tunable kondo effect in quantum dots   总被引:1,自引:0,他引:1  
A tunable Kondo effect has been realized in small quantum dots. A dot can be switched from a Kondo system to a non-Kondo system as the number of electrons on the dot is changed from odd to even. The Kondo temperature can be tuned by means of a gate voltage as a single-particle energy state nears the Fermi energy. Measurements of the temperature and magnetic field dependence of a Coulomb-blockaded dot show good agreement with predictions of both equilibrium and nonequilibrium Kondo effects.  相似文献   
36.
  • 1. Cymodocea nodosa's leaf length distribution was studied as an easily measurable indicator to monitor and conserve Macedonian, North Aegean, Greek coastal habitats.
  • 2. Three Cymodocea meadows off the eastern Kavala Gulf coast (Nea Karvali, Erateino, Agiasma), with that of Nea Karvali close to an industrial area being the most degraded, were sampled during the seagrass main growing season in July 2004. Two further meadows, one pristine to less degraded (Brasidas, Gulf of Kavala) and one degraded (Biamyl, Inner Thessaloniki Gulf), were sampled as benchmarks in July 2005. The results were evaluated using Gaussian fit curves, and non‐parametric and nested parametric ANOVA on a hierarchy of spatial scales: area (tens of metres), site (hundreds of metres) and meadow (kilometres).
  • 3. Frequency (%) distribution of leaf length values and CymoSkew index variation were best associated with anthropogenic stress. Frequency (%) distribution of adult and intermediate photosynthetic leaf length values revealed a unimodal distribution possible to be fitted, at least at pristine to less degraded meadows, by normal distribution (R2>0.5).
  • 4. Statistically significant variation was estimated for CymoSkew index, a quantitative expression of leaf length asymmetry, on the meadow scale (P<0.001). Biamyl (3.82) and Nea Karvali (3.64) were indicated as heavily degraded meadows, Erateino (2.93) as a degraded meadow, Agiasma (2.18) as a meadow with the first signs of degradation, and Brasidas (1.68) as a pristine to less degraded meadow. These results in combination with other meadow specific biotic parameters were used to suggest a preliminary angiosperm ‘Ecological Status Classes’ classification scheme useful for the implementation of WFD in the north Aegean Sea.
  • 5. The CymoSkew index seems to respond to lower levels of stress than is needed for other more conservative plant modules and therefore, could be regarded as an early warning indicator of Cymodocea habitat degradation. Copyright © 2009 John Wiley & Sons, Ltd.
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38.
Lingual abscessation is a rare condition in dogs. Very little information is available on the diagnosis and treatment of lingual abscesses in the major surgical textbooks and current veterinary literature. The common clinical signs of lingual abscesses are macroglossia, hypersalivation and a reluctance to open the mouth, but these can vary depending on the time course of the disease and the location of the abscess. This article presents three cases of tongue abscess in the dog outlining treatment and outcomes. A thorough diagnostic work up, consisting of anamnesis, clinical and haematological examinations, oral inspection under sedation and the use of diagnostic imaging techniques should be mandatory before surgical exploration of the abscess. Surgery is followed by drainage and systemic antibiotics, complemented by systemic fluid support and pain management. Conservative management of lingual abscesses can be fatal. Sharp trauma from an unknown object is suspected to be the underlying cause for the abscesses in the present cases.  相似文献   
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40.
Congenital vertebral malformations are common findings on diagnostic imaging of the vertebral column in “screw‐tailed” brachycephalic dogs. The aims of this study were to evaluate the prevalence and anatomical characteristics of lumbosacral congenital vertebral malformations in French Bulldogs, English Bulldogs, and Pugs presenting for problems unrelated to spinal disease, as well as possible associations with the degree of tail malformation, lumbosacral intervertebral disc herniation, or spondylosis deformans. In this retrospective cross‐sectional study, CT scans of vertebrae L6 to S3 and of the coccygeal vertebrae were reviewed for type of congenital vertebral malformations (hemivertebrae, block vertebrae, lumbosacral transitional vertebrae, and spina bifida), lumbosacral intervertebral disc herniation, lumbosacral spondylosis deformans, and degree of tail malformation. In 76 (51.0%) of the 149 included dogs (53 French Bulldogs, 37 English Bulldogs, and 59 Pugs) at least one type of congenital vertebral malformations was found, with lumbosacral transitional vertebrae being the most common (34.2%). There was a significantly higher prevalence of lumbosacral transitional vertebrae (54.2%) and lower prevalence of hemivertebrae (1.7%) in Pugs compared to English (13.5% and 24.3%, respectively) and French Bulldogs (26.4% and 32.0%, respectively). Tail malformation was significantly more severe in dogs with evidence of hemivertebrae. Congenital vertebral malformations are a common finding in the lumbosacral vertebral column of French Bulldogs, English Bulldogs, and Pugs. These anatomical variances need to be considered when interpreting diagnostic studies and when planning for neurosurgical and neurodiagnostic procedures. Furthermore, this study suggests a possible association between the degree of tail malformation and lumbosacral hemivertebrae.  相似文献   
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