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11.
Enteromyxum scophthalmi is a myxozoan parasite that causes severe parasitic diseases in cultured turbot affecting mainly the intestine of the host. It is characterized by producing acute enteritis, starvation and eventually death. Current diagnosis of E. scopthalmi use traditional techniques, based on the identification of the morphology of the parasite. These techniques take extended time to be carried out and do not favour the adoption of control measure at turbot farms and require the sacrifice of fish. This study develops a fast real‐time PCR molecular tool for the detection of E. scophthalmi in infected farmed turbot. This methodology is applicable for routine controls on the farm at every stage of the parasite infection. Results of the study demonstrate the robustness, specificity, efficiency and reliability of the technique. In addition, this study also provides a non‐invasive procedure of sampling through swaps. This allows control, prevention and diagnosis of the parasite infection at turbot farms while maintaining the welfare of the cultivated fish and avoiding sacrifice of the fish sampled.  相似文献   
12.
Formalin is used in shrimp industry to eliminate ectoparasites and as a disinfectant. However, the effect of formalin on shrimp's defense mechanism is unknown. Several biomarkers were used to assess the immune response of juveniles of the shrimp Litopenaeus schmitti exposed to different concentrations of formalin (10, 25 and 50 mg L?1) during 24 and 48 h. Formalin concentrations of 25 and 50 mg L?1 produced a significant reduction in the total haemocyte count at both 24 and 48 h. Peroxidase and phenoloxidase activity did not show variations. The total protein concentration in haemolymph of shrimps was not significantly different between experimental groups. Histological analysis showed hyperplasia in the gills of animals exposed at 10 mg L?1 for 24 h; however, the exposure at 25 and 50 mg L?1 caused necrosis in gills, hepathopancreas and the antennal gland.  相似文献   
13.
本实验选用12头体重为300-500kg,年龄2-3岁的雄性去势水牛,经粪便检查和Dot-ELISA检测确认为无肝片吸虫感染后,随机分为感染组(n=9)和对照组(n=3)。感染组每头水牛1次性经口感染1600个肝片吸虫囊蚴。实验期间由专人饲养,自由采食青干草和饮水。每周定时颈静脉采血,测定外周血淋巴细胞增殖反应、白细胞介素-2(IL-2)水平、T和B淋巴细胞比例、IgG水平以及血清蛋白总量和比例。结果表明:感染组水牛的T淋巴细胞刺激指数在感染后2-8周高于对照组,但刺激指数和IL-2与对照组均无显著性差异。感染组水牛的外周血T淋巴细胞比例从感染后第1周显著下降,以后一直在低于对照组水平波动,而淋巴细胞从感染后第1周开始显著升高,且一直在高于对照组范围内波动。感染组水牛的α-球蛋白、β-球蛋白与对照组相比均无显著性差异,而白蛋白从第5周开始显著下降,以后维持在低于对照组的水平范围波动;γ-球蛋白从第5周显著高于对照组,以后于对照组范围波动。感染组水牛的抗ES抗原(分泌-排泄抗原)的IgG抗体水平从第2周升高,并持续至实验结束。结果提示:体液免疫应答反应是水牛抗肝片吸虫感染的重要机制。  相似文献   
14.
Of 4,144 serum samples collected from cows on 113 farms from eight areas of Colombia 3.3% had positive and 8.8% inconclusive titres to Brucella abortus, 21.7, 6.3, 1.6, 0.6 and 0.7% of cows had positive titres to Leptospira serovars hardjo, pomona, canicola, icterohaemorrhagiae and grippotyphosa respectively. Questionnaires completed on 110 farms revealed that 6, 2.5 and 4.6% of cows had had metritis, aborted or retained their placentas respectively in the previous 12 months. Trichomonas foetus and Campylobacter fetus were isolated from 13.7% and 15% of the bulls sampled on 103 farms. Six and two bulls had inconclusive and positive titres to Brucella abortus. Eight and 23 bulls had positive titres to pomona and hardjo. The results were discussed and remedies for control suggested.  相似文献   
15.
This study examines milk production and the effect of milk production and sex of calf on body weights and gains of red deer calves and hinds of the Iberian subspecies (Cervus elaphus hispanicus). Milk production was assessed in 14 hinds by weighing calves before and after suckling and by adjusting these values to the Gamma function. Gamma estimates of total milk production up to d 105 were similar to the amounts computed directly from double weighing. Hinds showed two types of lactation curve: 1) the standard mammal lactation curve, with an asymmetrical peak at wk 2 to 4 (Type I) and 2) decreasing curves with no peak (Type II). Although there was great interindividual variability, hinds with Type I curves showed a trend to produce more milk than those with Type II. The type of curve did not seem to affect weight variables of the calf or those of the dam. Calves that gained more weight consumed greater amounts of milk (P<.05). Males were heavier than females at birth (P<.05), but males did not differ from females in their weight at 105 d, milk consumption, and gain. Gender did not affect hind weight, but dams of male calves showed a trend to be lighter (P = .063) at d 105 than dams of female calves. Our results suggest that suckling differences found in other studies between male and female calves may not involve differences in milk production, although other rearing costs seem to affect hind weight losses. They also suggest that the curve type may not depend only, as reported, on the nutrition plane.  相似文献   
16.
Chlorosis level is a useful parameter to assess imidazolinone resistance in sunflower (Helianthus annuus L.). The aim of this study was to quantify chlorosis through two different methods in sunflower plantlets treated with imazapyr. The genotypes used in this study were two inbred lines reported to be different in their resistance to imidazolinones. Chlorosis was evaluated by spectrophotometrical quantification of photosynthetic leaf pigments and by a bioinformatics-based color analysis. A protocol for pigment extraction was presented which improved pigment stability. Chlorophyll amount decreased significantly when both genotypes were treated with 10 μM of imazapyr. Leaf color was characterized using Tomato Analyzer® color test software. A significant positive correlation between color reduction and chlorophyll concentration was found. It suggests that leaf color measurement could be an accurate method to estimate chlorosis and infer chlorophyll levels in sunflower plants. These results highlight a strong relationship between imidazolinone-induced chlorosis and variations in leaf color and in chlorophyll concentration. Both methods are quantitative, rapid, simple, and reproducible. Thus, they could be useful tools for phenotyping and screening large number of plants when breeding for imidazolinone resistance in this species.  相似文献   
17.
18.

• Introduction  

The abandonment of rural areas has led to an increase of the fire-prone European gorse (Ulex europaeus L.) communities in some regions, where prescribed burning is a technique applied to control them. Understanding flammability changes after treatments is crucial for the sustainable use of fire.  相似文献   
19.
Cerambyx welensii Küster is one of the greatest threats to Quercus suber L. and Quercus ilex L. in Spain. Efficient control methods for this species are currently being tested, and the use of traps baited with food-related products for their monitoring and control has been proposed. Cerambyx welensii adults prefer to colonize old or decayed trees, in which cortical exudates frequently release fermentation odors. Fermentation-related compounds, such as ethanol, have been cited as attractants to various hardwood woodborers (as Cerambyx cerdo L.), used either alone or sometimes in combination with other host odors. In this work, we conducted field experiments to ascertain whether chemical blends mimicking fermentation odors were attractive for C. welensii. To this end, we used three types of traps (multiple funnel, cross-vane and single-funnel) baited with six synthetic blends including one or more fermentation-related chemicals (ethanol, ethyl acetate, 3-methyl-1-butanol, acetaldehyde, 2-methyl-1-propanol and 2-methyl-1-butanol), various food-related products (beer, melon and red wine mixed with peach juice) and host monoterpenes (α-pinene, β-pinene, limonene, α-phellandrene and camphene). At high release rates (5–11 g/day), various synthetic blends proved attractive irrespective of trap type. Our results contribute to understand the impact of volatile organic compounds in host selection by woodborers infesting deciduous trees. The results hold promise for optimizing trapping strategies to control C. welensii within an integrated pest management framework.  相似文献   
20.
Godefroid  M.  Morente  M.  Schartel  T.  Cornara  D.  Purcell  A.  Gallego  D.  Moreno  A.  Pereira  J. A.  Fereres  A. 《Journal of pest science》2022,95(2):855-868

The bacterium Xylella fastidiosa (Xf) is an invasive insect-borne pathogen, which causes lethal diseases to important crops including olives, citrus, almonds and grapes as well as numerous forest, ornamental, and uncultivated plants. Outbreaks of Xf-related plant diseases are currently occurring in the Mediterranean region, causing substantial losses to various agricultural sectors. Several models have recently been published to identify which regions are at highest risk in Europe; however, such models did not consider the insect vectors, which constitute the key driver of short-range Xf spread. We fitted bioclimatic species distribution models to depict the macroclimatic preferences of the meadow spittlebug Philaenus spumarius L. (1978) (Hemiptera: Aphrophoridae), the major epidemiologically relevant vector currently responsible for Xf spread in the Europe. Many regions of Western Europe and Mediterranean basin are predicted by models as highly climatically suitable for this vector, including all regions where severe Xf have occurred so far. Conversely, the driest and warmest areas of the Mediterranean basin are predicted as little suitable for P. spumarius. Models forecast that agricultural-important parts of the southern Mediterranean area might experience a substantial decrease in climatic suitability for P. spumarius by the period 2040–2060. Areas predicted as highly suitable just for the bacterium but not optimal for this vector are apparently still free of severe Xf outbreaks, suggesting that climate tolerances of P. spumarius might partly explain the current spatial pattern of Xf outbreaks in Europe and should always be considered in further risk assessments.

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