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1.
1. Two groups of chicks (Gallus domesticus) were fed on a vitamin A‐deficient diet for 24 d. Birds in one group, which acted as a control, were dosed orally with retinyl palmitate in corn oil, whereas the other group (experimental) was given corn oil only throughout the experiment.
2. At regular intervals birds in both groups were stimulated orally with solutions of acetic acid, quinine hydrochloride and sodium chloride and the number of beak and tongue movements counted.
3. By the end of the experiment the vitamin A‐deficient birds showed a significant decrease in their response to the oral stimulants compared with the control birds. 相似文献
2.
Reuss-Lamky H 《Journal of the American Animal Hospital Association》2007,43(5):298-305
Dental nerve blocks provide excellent pain management for many oral procedures. They are easy and inexpensive to perform, provide a rapid onset of action, and work in concert with anesthetic and other analgesic modalities. This article explains how to administer various dental nerve blocks and discusses the indications and precautions associated with their use. 相似文献
3.
Katriina Kyllönen Hannele Hakola Heidi Hellén Markku Korhonen Matti Verta 《Water, air, and soil pollution》2012,223(3):1171-1182
Total gaseous mercury (TGM) fluxes from the forest floor and a boreal wetland were measured by a flux chamber technique coupled
with an automatic mercury vapour analyser. The fluxes were measured at three sampling sites in southern Finland, 61°14′ N,
25°04′ E in summer 2007, with additionally in situ TGM concentrations in the air at one of the sites and mercury bulk deposition
at another. Most of the flux data were collected during the daytime. At one of the sites, diurnal flux behaviour was studied,
and a clear cycle with an afternoon maximum and a night minimum was observed. The highest emissions (up to 3.5 ng m−2 h−1) were observed at the forest floor site having a moss and grass cover. At the wetland and litter-rich forest floor sites,
the emissions were below 1 ng m−2 h−1 and sometimes negative (down to −1.0 ng m−2 h−1), indicating mercury uptake. The measured average fluxes in August were 0.9 ± 1.1 and 0.2 ± 0.3 ng m−2 h−1 for the forest floor sites and wetland sites, respectively. The flux data were compared with the mercury bulk deposition,
which proved to be of the same magnitude, but opposite in sign. At the mossy forest floor site, the extrapolated TGM emissions
were 130% of the Hg deposition in August 2007. Comparison with other studies showed that the fluxes in background areas are
relatively uniform, regardless of measurement site location and method used. Airborne TGM remained at the background level
during the study, with an average value of 1.3 ± 0.2 ng m−3; it frequently showed a diurnal cycle pattern. 相似文献
4.
Combining agent-based and stock-flow modelling approaches in a participative analysis of the integrated land system in Reichraming, Austria 总被引:1,自引:0,他引:1
Veronika Gaube Christina Kaiser Martin Wildenberg Heidi Adensam Peter Fleissner Johannes Kobler Juliana Lutz Andreas Schaumberger Jakob Schaumberger Barbara Smetschka Angelika Wolf Andreas Richter Helmut Haberl 《Landscape Ecology》2009,24(9):1149-1165
The integrated modelling of coupled socio-ecological systems in land-change science requires innovative model concepts capable of grasping the interrelations between socioeconomic and natural components. Here, we discuss the integrated socio-ecological model SERD (Simulation of Ecological Compatibility of Regional Development) that was developed for the municipality of Reichraming in Upper Austria in a participative 2-year process involving local stakeholders. SERD includes three main components: (1) an agent-based actors module that simulates decisions of farmsteads, the municipal administration and other important actors; (2) a spatially explicit (GIS based) land-use module that simulates land-use change at the level of individual parcels of land and (3) an integrated socio-ecological stock-flow module that simulates carbon and nitrogen flows through both socioeconomic and ecological system compartments. We report on outcomes of a scenario analysis that outlines possible future trajectories depending on both external (e.g. agricultural subsidies and prices) and internal (e.g. innovation, willingness to co-operate) factors. We find that both external and internal factors can affect the behaviour of the integrated system considerably. Local and regional policies are found to be able to counteract adverse global socioeconomic conditions to some extent, but not to reverse the trend altogether. We also find strong interdependencies between socioeconomic and ecological components of the system. Fully evaluating these interdependencies is, however, not possible at the local scale alone and will require explicit consideration of higher-level effects in future research. 相似文献
5.
We determined whether canola oil could spare menhaden oil (MO) in diets containing minimal fish meal without affecting sunshine bass, Morone chrysops × Morone saxatilis, production. Seven isonitrogenous, isocaloric (41.7% crude protein and 14.6% crude lipid) diets containing graded levels (0, 20, 40, 60, 80, or 100%) of menhaden to canola oils with 20% menhaden meal (MM) or 100% canola oil with 20% lipid‐extracted MM were fed to sunshine bass (initial weight 9.3 ± 0.16 g; mean ± SD) twice daily to apparent satiation for 10 wk. Sunshine bass fed less than 40% of their dietary lipid as MO exhibited significantly (P < 0.05) lower feed intake and growth rates. Increased concentrations of saturated, n‐3, and n‐3 highly unsaturated fatty acids (FA) in the fillet were associated with MO‐rich diets, while monounsaturated and n‐6 FA were most common in fillets from fish fed diets rich in canola oil. Reducing MO to 40% of the dietary lipid in diets containing minimal fish meal allows for efficient utilization of marine resources without negatively impacting juvenile sunshine bass production. 相似文献
6.
Whigham HM Brooks DE Andrew SE Gelatt KN Strubbe DT Biros DJ 《Veterinary ophthalmology》1999,2(4):243-250
Contact neodymium:yttrium aluminum garnet (Nd:YAG) laser transscleral cyclophotocoagulation (TSCP) was performed on 23 eyes of 16 horses for treatment of glaucoma. The mean highest preoperative IOP was 51 ± 17 mmHg. Follow-up evaluation was available for 19 eyes 1 day after surgery, 14 eyes from 1 to 2 weeks, 16 eyes from 4 to 6 weeks, 9 eyes from 12 to 16 weeks, and 10 eyes greater than 20 weeks after laser treatment. The mean intraocular pressure (IOP) the day following surgery was 34 ± 13 mmHg. The mean IOP for each follow-up period was: one to two weeks postoperative, 23 ± 9 mmHg; four to six weeks, 24 ± 7 mmHg; 12–16 weeks, 28 ± 10 mmHg; and 20 weeks, 22 ± 9 mmHg. IOP measurements were significantly different from pretreatment values for all follow-up intervals except for weeks 12–16 ( P < 0.05). Treatment success was defined as maintenance of IOP < 30 mmHg. Treatment success was achieved in 93%, 88%, 78%, and 70% of the treated eyes at the 1–2 weeks, 4–6 weeks, 12–16 weeks, and the 20 weeks re-evaluation, respectively. No significant difference was found between the number of eyes visual at presentation (52.2%) and visual at 20 weeks (60%). The most common laser complications were conjunctival hyperemia (21.7%) and corneal ulcers (13.0%). Results of this study indicate that Nd:YAG TSCP is an effective method of controlling IOP and preserving vision in horses with glaucoma. An effective Nd:YAG laser protocol for TSCP in the equine glaucomatous eye is a power setting of 11 W, duration of 0.4 s, applied 5 mm posterior to the limbus at 60 sites, resulting in a total energy dose of 264 J. 相似文献
7.
8.
Finding cardiovascular disease genes in the dog 总被引:2,自引:0,他引:2
Heidi G. Parker PhD Kathryn M. Meurs DVM PhD Elaine A. Ostrander PhD 《Journal of Veterinary Cardiology》2006,8(2):115-127
Recent advances in canine genomics are changing the landscape of veterinary biology, and by default, veterinary medicine. No longer are clinicians locked into traditional methods of diagnoses and therapy. Rather, major advances in canine genetics and genomics from the past five years are now changing the way the veterinarian of the 21st century practices medicine. First, the availability of a dense genome map gives canine genetics a much-needed foothold in comparative medicine, allowing advances made in human and mouse genetics to be applied to companion animals. Second, the recently released 7.5× whole genome sequence of the dog is facilitating the identification of hereditary disease genes. Finally, development of genetic tools for rapid screening of families and populations at risk for inherited disease means that the cost of identifying and testing for disease loci will significantly decrease in coming years. Out of these advances will come major changes in companion animal diagnostics and therapy. Clinicians will be able to offer their clients genetic testing and counseling for a myriad of disorders. In this review we summarize recent findings in canine genomics and discuss their application to the study of canine cardiac health. 相似文献
9.
Heidi Bouws Maria R. Finckh 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(4):313-327
The effects of origin of seed potatoes and the cropping history on the phenotypic structure of Phytophthora infestans populations was studied in northern Hessia, central Germany, from 2000 to 2002. Populations originating from fields with
a history of potato cropping with only short or no rotation (old fields) were compared with populations from new fields, i.e.,
where no potatoes had been grown for at least 30 years and seed potatoes were either imported from breeders or produced on-farm
(certified). The main goal was to determine the importance of seed potato infection in the establishment of new P. infestans populations. Isolates were characterized for mating type, virulences and rep- (repetitive extragenic palindromic) PCR fingerprints.
Among a total of 639 isolates sampled from 31 sites, mating types A1 and A2 co-existed in all three years in 60–92% of the
sites. Over all three years, 53 pathotypes were detected in a subsample of 272 isolates. Isolates originating from the new
fields had significantly higher frequencies of the virulences v1, v2, v3, v6 and v7, indicating general effects of seed introduction
into a new region. Thirty-six fingerprints were detected in a subsample of 281 isolates of which 22 were unique while four
occurred in all three years and in many sites. Pathogen populations from potato fields that were grown from seed tubers of
geographically different origin differed significantly based on χ
2 tests. While the Nei genetic distances were less than .1 among the local populations, distances to the US lineages US-1,
US-6, US-7 and US-8 ranged from .22 to .47; however, the bootstrap values were not significant. Populations from old fields
were more diverse and 14 of the 22 rep-PCR types occurred there among 132 isolates tested in comparison to six in the new
fields (n = 140 isolates) and two among six isolates from volunteers. The results also suggest that both sexual and asexual reproduction
play a role. 相似文献
10.
Carbon sequestration in the trees, products and soils of forest plantations: an analysis using UK examples 总被引:1,自引:0,他引:1
A carbon-flow model for managed forest plantations was used to estimate carbon storage in UK plantations differing in Yield Class (growth rate), thinning regime and species characteristics. Time-averaged, total carbon storage (at equilibrium) was generally in the range 40-80 Mg C ha(-1) in trees, 15-25 Mg C ha(-1) in above- and belowground litter, 70-90 Mg C ha(-1) in soil organic matter and 20-40 Mg C ha(-1) in wood products (assuming product lifetime equalled rotation length). The rate of carbon storage during the first rotation in most plantations was in the range 2-5 Mg C ha(-1) year(-1).A sensitivity analysis revealed the following processes to be both uncertain and critical: the fraction of total woody biomass in branches and roots; litter and soil organic matter decomposition rates; and rates of fine root turnover. Other variables, including the time to canopy closure and the possibility of accelerated decomposition after harvest, were less critical. The lifetime of wood products was not critical to total carbon storage because wood products formed only a modest fraction of the total.The average increase in total carbon storage in the tree-soil-product system per unit increase in Yield Class (m(3) ha(-1) year(-1)) for unthinned Picea sitchensis (Bong.) Carr. plantations was 5.6 Mg C ha(-1). Increasing the Yield Class from 6 to 24 m(3) ha(-1) year(-1) increased the rate of carbon storage in the first rotation from 2.5 to 5.6 Mg C ha(-1) year(-1) in unthinned plantations. Thinning reduced total carbon storage in P. sitchensis plantations by about 15%, and is likely to reduce carbon storage in all plantation types.If the objective is to store carbon rapidly in the short term and achieve high carbon storage in the long term, Populus plantations growing on fertile land (2.7 m spacing, 26-year rotations, Yield Class 12) were the best option examined. If the objective is to achieve high carbon storage in the medium term (50 years) without regard to the initial rate of storage, then plantations of conifers of any species with above-average Yield Classes would suffice. In the long term (100 years), broadleaved plantations of oak and beech store as much carbon as conifer plantations. Mini-rotations (10 years) do not achieve a high carbon storage. 相似文献