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91.
There has been limited research on measuring potential differences in leaf gas exchange of Arracacha (Peruvian parsnip, Arracacia xanthorriza Bancroft) cultivars, as affected by different environments, as well as its relation to storage root-yield. The present paper reports field measurements of leaf CO2 assimilation rates (A) for five contrasting cultivars grown at two different high-altitude locations. Using a design of plots chosen at random with three repetitions, commercial root production was determined in the two locations at different altitude (1580 and 1930 m). Daily leaf gas exchange was repeatedly monitored with a portable open-mode infrared gas analyzer at different times in both locations during the growth cycle. Root-yield, leaf area and dry weight were measured. Significant differences in leaf photosynthetic rate and in specific leaf area (SLA) were observed among cultivars. Cultivars with high SLA, had high CO2 assimilation. Mean (An) and total (Atot) of CO2 assimilation and SLA were significantly correlated with storage root-yield across cultivars and locations. The three cultivars with the greatest commercial root production also had the highest maximum values for A and the highest specific leaf area, indicating that these two parameters can be used to select for highly productive cultivars of A. xanthorriza. 相似文献
92.
Bruno H. Pypendop Kristine T. Siao M.G. Ranasinghe Kirby Pasloske 《Veterinary anaesthesia and analgesia》2018,45(3):269-277
Objective
To determine the effective plasma alfaxalone concentration for the production of immobility in cats.Study design
Prospective up-and-down study.Animals
Sixteen 1–2 year old male castrated research cats.Methods
Cats were instrumented with catheters in a jugular and a medial saphenous vein. Alfaxalone was administered via the medial saphenous catheter, using a target-controlled infusion system. The infusion lasted for approximately 32 minutes. A noxious stimulus (tail clamp) was applied 30 minutes after starting the alfaxalone infusion, until the cat moved or 60 seconds had elapsed, whichever occurred first. The target alfaxalone concentration was set at 5 mg L?1 in the first cat and increased or decreased by 1 mg L?1 in subsequent cats, if the previous cat had moved or not moved in response to stimulation, respectively. This was continued until six independent crossovers (different responses in pairs of subsequent cats) had been observed. Blood samples were collected before alfaxalone administration, and 15 and 31 minutes after starting the administration, for the determination of plasma alfaxalone concentration using liquid chromatography/tandem mass spectrometry. The alfaxalone concentration yielding a probability of immobility in 50% (EC50), 95% (EC95) and 99% (EC99) of the population, and their respective 95% Wald confidence intervals were calculated.Results
The EC50, EC95 and EC99 for alfaxalone-induced immobility were 3.7 (2.4–4.9), 6.2 (4.7–) and 7.6 (5.5–) mg L?1, respectively.Conclusions and clinical relevance
The effective plasma alfaxalone concentration for immobility in cats was determined. This value will help in the design of pharmacokinetic-based dosing regimens. 相似文献93.
Histomoniasis or blackhead is a disease of gallinaceous birds, caused by the protozoon Histomonas meleagridis. Since traditional diagnostics for the detection of this disease are complex and far less sensitive than molecular tools, a PCR would provide a more rapid and sensitive alternative. However, intestinal material and droppings, which are preferably used in epidemiological studies of histomoniasis, often contain PCR inhibitory substances. To detect these false negative results, the use of an internal amplification control is essential. Nevertheless, the recently developed PCR tests lack this internal control. Therefore, a new PCR assay with H. meleagridis specific primers was developed which does include an internal amplification control. The diagnostic value of the PCR assay was evaluated in comparison to three other conventional H. meleagridis specific PCR tests (HIS5, HM1 and HM2). None of the organ samples originating from uninfected turkeys, showed positive PCR results in any of the tests. Among the lesion-positive, inhibition-free samples, 95.4% were positive by our PCR assay, while only 50, 66.7 and 83.3% of the lesion-positive organs tested positive by the HM1, the HIS5 and the HM2 PCR respectively. In conclusion, our PCR offers the use of the internal control to detect false negative results and an increased sensitivity, and thus should be useful for routine diagnosis of H. meleagridis in poultry. 相似文献
94.
Gastrointestinal protozoa in non-human primates of four zoological gardens in Belgium 总被引:1,自引:0,他引:1
Gastrointestinal parasites are important infectious causes of diarrhoea in captive non-human primates (NHP). However, prevalence data of gastrointestinal parasites in zoological gardens are scarce. Therefore, a cross-sectional survey was conducted to estimate the occurrence of gastrointestinal parasites in NHP of four zoological gardens in Belgium. Between August 2004 and April 2006, 910 faecal samples were collected from 222 animals housed in 39 groups. The 31 species involved were representatives of prosimians, New World (NW) monkeys, Old World (OW) monkeys and apes. Because individual sampling was impossible, a statistical simulation was performed to estimate a sufficient sample size. All samples were microscopically examined after an acetic acid-ether concentration. Differences in host species susceptibility were examined by non-parametric tests. Entamoeba spp. (44%) and Giardia spp. (41%) were the most prevalent species. Other parasites detected were Endolimax nana (36%), Chilomastix mesnili (21%), Balantidium coli (13%), Trichuris spp. (10%), Iodamoeba bütschlii (5%) and Strongyloides spp. (5%). Parasites for which a significant difference in susceptibility at the level of host taxonomy was noted were Entamoeba spp. (p<0.001) and C. mesnili (p<0.05). Samples containing Entamoeba spp. were the most prevalent in OW monkeys (p<0.0083). Samples collected from OW monkeys contained the highest number of parasite species (p<0.0083). 相似文献
95.
Janaina Mitsue Kimpara Fabricio Ribeiro Tito Rosa Bruno de Lima Preto Wagner C Valenti 《Aquaculture Research》2011,42(9):1289-1297
We evaluated the water characteristics and particle sedimentation in Macrobrachium amazonicum (Heller 1862) grow‐out ponds supplied with a high inflow of nutrient‐rich water. Prawns were subject to different stocking and harvesting strategies: upper‐graded juveniles, lower‐graded juveniles, non‐graded juveniles+selective harvesting and traditional farming (non‐grading juveniles and total harvest only). Dissolved oxygen, afternoon N‐ammonia and N‐nitrate and soluble orthophosphate were lower in the ponds in comparison with inflow water through the rearing cycle. Ponds stocked with the upper population fraction of graded prawns showed higher turbidity, total suspended solids and total Kjeldahl nitrogen than the remaining treatments. An increase in the chemical oxygen demand:biochemical oxygen demand ratio from inlet (4.9) to pond (7.1–8.0) waters indicated a non‐readily biodegradable fraction enhancement in ponds. The sedimentation mean rate ranged from 0.08 to 0.16 mm day?1 and sediment contained >80% of organic matter. The major factors affecting pond ecosystem dynamic were the organic load (due to primary production and feed addition) and bioturbation caused by stocking larger animals. Data suggest that M. amazonicum grow‐out in ponds subjected to a high inflow of nutrient‐rich water produce changes in the water properties, huge accumulation of organic sediment at the pond bottom and non‐readily biodegradable material in the water column. However, the water quality remains suitable for aquaculture purposes. Therefore, nutrient‐rich waters, when available, may represent a source of unpaid nutrients, which may be incorporated into economically valued biomass if managed properly. 相似文献
96.
The influence of dietary fatty acid and fasting on the hepatic lipid metabolism of barramundi (Lates calcarifer) 下载免费PDF全文
Bruno Araújo Michael Salini Brett Glencross Nicholas Wade 《Aquaculture Research》2017,48(7):3879-3893
For many fish species, dietary fish oil (FO) has been substituted with other oils such as poultry oil (PO) without affecting growth performance. However, in barramundi, the mechanisms by which fatty acid metabolism is regulated are poorly understood, and the effects of FO substitution are unknown. This study defined changes in the expression of genes controlling the metabolism of fatty acids in barramundi over a 24‐h time period after a single meal. From one to 12 h after a single feeding event, the expression of fatty acid synthesis genes in the liver was upregulated, while genes involved in the β‐oxidation showed minimal alteration. However, the expression of β‐oxidation genes was significantly correlated with the expression of genes regulating fatty acid synthesis. In a second experiment, the changes in liver fatty acid composition and gene expression were defined after FO was substituted with PO. Liver fatty acid profile reflected the diet composition, with some subtle exceptions supporting the enrichment of certain long‐chain polyunsaturated fatty acids in the liver. The fish from all experimental groups preferentially retained more docosahexaenoic acid than eicosapentaenoic acid in the liver, suggesting a bioconversion of this fatty acid to intermediate fatty acids. Replacement of FO with PO significantly regulated genes controlling both fatty acid synthesis and catabolism pathways, potentially related to a higher percentage of monounsaturated fatty acids, in the livers of fish fed these diets. The results demonstrated that diet composition significantly altered the lipid metabolism in barramundi and that there was a balance between direct dietary effects and endogenous synthetic capacity. 相似文献
97.
Bruno Reis Ana Teresa Gonalves Paulo Santos Manuel Sardinha Luís E. C. Conceio Renata Serradeiro Jaume Prez-Snchez Josep Calduch-Giner Ulrike Schmid-Staiger Konstantin Frick Jorge Dias Benjamín Costas 《Marine drugs》2021,19(12)
This work aimed to evaluate the effects of dietary supplementation with β-glucans extracted from yeast (Saccharomyces cerevisiae) and microalga (Phaeodactylum tricornutum) on gene expression, oxidative stress biomarkers and plasma immune parameters in gilthead seabream (Sparus aurata) juveniles. A practical commercial diet was used as the control (CTRL), and three others based on CTRL were further supplemented with different β-glucan extracts. One was derived from S. cerevisiae (diet MG) and two different extracts of 21% and 37% P. tricornutum-derived β-glucans (defined as Phaeo21 and Phaeo37), to give a final 0.06% β-glucan dietary concentration. Quadruplicate groups of 95 gilthead seabream (initial body weight: 4.1 ± 0.1 g) were fed to satiation three times a day for 8 weeks in a pulse-feeding regimen, with experimental diets intercalated with the CTRL dietary treatment every 2 weeks. After 8 weeks of feeding, all groups showed equal growth performance and no changes were found in plasma innate immune status. Nonetheless, fish groups fed β-glucans supplemented diets showed an improved anti-oxidant status compared to those fed CTRL at both sampling points (i.e., 2 and 8 weeks). The intestinal gene expression analysis highlighted the immunomodulatory role of Phaeo37 diet after 8 weeks, inducing an immune tolerance effect in gilthead seabream intestine, and a general down-regulation of immune-related gene expression. In conclusion, the results suggest that the dietary pulse administration of a P. tricornutum 37% enriched-β-glucans extract might be used as a counter-measure in a context of gut inflammation, due to its immune-tolerant and anti-oxidative effects. 相似文献
98.
99.
Bruno O. David Matt Jarvis Deniz
zkundakci Kevin J. Collier Andy S. Hicks Malcolm Reid 《水产资源保护:海洋与淡水生态系统》2019,29(9):1409-1423
100.
Kennya Gomes Silva Addam Scheila Anelise Pereira Gabriel Fernandes Alves Jesus Lucas Cardoso Nichola Syracuse Gustavo Ruschel Lopes Nicollas Breda Lehmann Bruno Correa da Silva Lúvia Souza de S Francisco Clio Maia Chaves Maurício Latera Martins Jos Luiz Pedreira Mourio 《Aquaculture Research》2019,50(10):2960-2971
This study evaluated the effects of dietary supplementation of organic acids blend (OAB) alone or in combination with essential oil, Lippia origanoides (OAE) for Nile tilapia fed supplemented diets for 30 days. Fish (1.1 ± 0.04 g) were fed control (Control), or OAB 0.5% or OAB 0.5% + essential oil 0.125% (OAE) respectively. At the end of the experiment, samples were collected for de hemato‐immunological, histological analysis of the intestine and liver, as well as microbiology of the intestine. The pH of the diets supplemented with OAB and OAE reduced 0.92 and 0.19 respectively. The growth and FCR were unaffected by the treatments, but survival was significantly higher in the OAB treatment. Fish fed the OAB diet showed reduced concentration of total heterotrophic bacteria and Pseudomonas sp. in the intestine. Increased glucose in fish fed OAB and high number of circulating monocytes in fish fed OAE diet were observed. The anterior intestine of fish fed OAE diet showed larger number of goblet cells and increased villi height. The diet supplemented with OAB, mainly, improved the intestinal health and survival of tilapia juveniles and can be used in juvenile production. 相似文献