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841.
Acton L Bruner M Lemen J Tsuneta S Ogawara Y Nishimura J Bentley R Culhane L Canfield R Hudson H Doschek G Hiei E Hirayama T Kosugi T Watanabe T Lang J Makishima K Uchida Y 《Science (New York, N.Y.)》1992,258(5082):618-625
The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission. 相似文献
842.
A standard method for the detection and isolation of microplastics is required to adequately investigate plastic ingestion by juvenile fish. Dissections of juvenile fish guts require precise handling, which can affect the processing time if sample numbers are high. To investigate the efficacy of nitric acid (HNO3) in aiding the isolation of microplastics using whole fish, we digested juvenile glassfish, Ambassis dussumieri (Cuvier, 1828), at room temperature and at 80 °C. For a complete digestion, overnight incubation in 10 mL of 55% analytical-reagent (AR) HNO3 was sufficient for a whole fish of 1 g at room temperature. When coupled with elevated temperature, the digestion time is shortened to a few minutes and larger fish of 3 g can be digested in 30 min. Four of the five types of plastic survived the process, with nylon being the exception. This is a shortfall to the method; however, until a better method replaces it, we still value the use of HNO3 for its simple, inexpensive, swift and complete digestions of whole fish. Four fish species from two feeding guilds were digested using this method to validate its use. The number of plastic particles ingested did not differ between benthic and pelagic species and microplastic fibres comprised the majority of the plastic types found. 相似文献
843.
应用基于PLSR的土壤-环境模型预测土壤属性 总被引:2,自引:0,他引:2
土壤-环境模型对于正确理解土壤属性与环境因子间的关系,以及进行土壤属性预测与制图均具有重要的意义。研究区位于陕西省长武县内多年退耕还林还草沟壑区域,采集72个土壤表层样本,选择3/4的样本作为建模集,其余1/4的样本作为验证集;环境因子选择容易获取的地形因子和由遥感影像提取的植被因子和湿度因子,建立基于偏最小二乘回归(PLSR)的土壤-环境模型。结果表明:全氮、速效钾、全钾、有机质与环境因子间均有显著相关性;建立的PLSR模型可解释土壤属性的空间变异从23%(全氮)到27%(全钾);与逐步回归方法构建的模型相比,利用PLSR构建的土壤-环境模型可以更好地表征土壤属性与环境变量间的关系,拟合精度和预测精度也相对较高,说明PLSR建立的模型可以更好地应用于相似区域的土壤属性预测。 相似文献
844.
Significant efforts should be devoted to reducing waste outputs from aquaculture operations in order to lower the environmental impacts of aquaculture in many parts of the world. Since most aquaculture wastes are ultimately from dietary origin, reduction of waste outputs should first be through improvements of diet formulation and feeding strategies. The first step in the production of feeds producing less solid waste is to eliminate poorly digestible ingredients (such as whole grain or grain by-products used as binders and fillers in the feed formulae) and to use highly digestible ingredients with good binding properties. Further reduction of solid waste can then be achieved through careful selection of the ingredients to improve apparent digestibility and the nutrient balance of the feed. Nitrogen waste outputs can be reduced through the reduction of the digestible protein to digestible energy (DP/DE) ratio of the diet. Phosphorus waste outputs can be reduced through careful selection of the ingredients and optimization of the digestible phosphorus content of the diet to meet the requirement of the fish but avoid greatly exceeding this required level. Finally, feeding practices that minimize feed wastage should be adopted since feed wastage can have a very significant impact on waste outputs from fish culture operations. 相似文献
845.
Mónica Berbegal Luis Armando Álvarez Ana Pérez-Sierra Josep Armengol 《Phytoparasitica》2012,40(1):1-4
Pythium isolates were recovered from endive plants (Cichorium endivia) showing vascular necrosis collected from commercial fields located in Castellón province (eastern Spain). They were identified
as Pythium tracheiphilum on the basis of their phenotypical and molecular profile. Pathogenicity tests conducted with two P. tracheiphilum isolates, obtained from endive and lettuce (Lactuca sativa), respectively, in this region, confirmed that both isolates were pathogenic to endive, with no significant differences in
virulence between them. This is the first report of vascular necrosis caused by P. tracheiphilum on endive in Spain. 相似文献
846.
A 12‐year‐old Paint‐Arab mare was admitted for evaluation of a penetrating chest laceration at the thoracic inlet. The left brachiocephalic muscle was transected and the recurrent laryngeal nerve was traumatised. Subsequent to the injury, the horse developed Horner's syndrome on the left side of the neck and face, Grade IV left laryngeal hemiplegia, dysphagia, cough and subcutaneous emphysema. The defect was closed in multiple layers. Antimicrobial and antiinflammatory therapy was instituted along with local wound care. The mare remained bright and responsive and the wound healed normally. The mare showed no signs of respiratory distress. Dysphagia and ptosis persisted at 30 days post trauma. 相似文献
847.
Bhupamani Das Niranjan Kumar Mehul M. Jadav Jayesh B. Solanki T.K.S. Rao 《Tropical animal health and production》2017,49(8):1577-1589
This study aims to evaluate the conjunctiva colour-based FAMACHA score (FS) coupled with a body condition score (BCS), haemogram and stressor hormone level estimation, in identifying post-mortem (PM)/coproscopically proven individuals wanting therapy for economically important gastrointestinal (GI) helminths, Haemonchus contortus, in the small ruminants. The incidence of haemonchosis was significantly (p < 0.05) higher (60.81%) in the ruminants with FS = 3. The H. contortus count in the animals with FS 2, 3 and 4 was 23.2 ± 0.37, 62 ± 2.5 and 74 ± 3.2 (p < 0.05) [positive correlation (r = 0.841 in goats; r = 0.828 in sheep, p < 0.05)], respectively, with corresponding 2.8 ± 0.15, 2 ± 0.3 and 2 ± 0.16 BCS (negative correlation, p > 0.05). The infected animals of FS 2, 3 and 4 measured 8.2 ± 0.0, 7.5 ± 0.23 and 6.7 ± 0.34 g/dl Hb (r = ?0.452, p = 0.01) in goats/9.3 ± 0.8, 8.6 ± 0.5 and 7.6 ± 0.3 g/dl Hb (r = ?0.511, p = 0.05) in sheep with 21.2, 19.8 ± 1.8 and 17.8 ± 0.2% PCV (r = ?0.369, p = 0.05) in goats/26.7 ± 1.2, 22.2 ± 0.2 and 20.9 ± 0.6% PCV (r = ?0.251, p = 0.03) in sheep, respectively. The FS 2, 3 and 4 infected goats/sheep measured 6.1 ± 0, 7.9 ± 1.0 and 9.5 ± 0.9 (p < 0.05)/5.8 ± 2.3, 6.9 ± 1.2 and 7.8 ± 0.2% (p < 0.05) mid-granulocyte [(r = 0.928 (goats)/0.834 (sheep), p < 0.05], while the cortisol level was 15.6, 23 ± 4.5 and 42 ± 2.3 (p = 0.23)/12.1 ± 0, 15.9 ± 1.2 and 24 ± 3.4 (p = 0.29) μg/dl, respectively. The infected ruminants recorded low (p < 0.05) level of Hb/PCV while high level of mid-granulocytes/cortisol. Specificity of FAMACHA test was maximized (100%) when FS = 4 was considered anaemic, but sensitivity was low (35.29% in goats; 25% in sheep). The false negatives was 5.9 (goat)/12.5 (sheep)% when FS ≥ 3 was considered anaemic. The small ruminants with FS ≥ 3, BCS ≤ 2.5, Hb ≤ 7.5 g/dl (goats)/8.6 g/dl (sheep), PCV ≤ 19.8% (goats)/22.2% (sheep) and mid-granulocyte ≥7.9% (goats)/6.9 ± 1.2% (sheep) can be subjected to target-selective treatment for haemonchosis in the field simultaneously maximizing the economic benefit to the farmers. 相似文献
848.
Lorenzon S Wesonga H Ygesu L Tekleghiorgis T Maikano Y Angaya M Hendrikx P Thiaucourt F 《Veterinary microbiology》2002,85(2):111-123
Contagious caprine pleuropneumonia (CCPP) is a major threat to goat farming in developing countries. Its exact distribution is not well known, despite the fact that new diagnostic tools such as PCR and competitive ELISA are now available. The authors developed a study of the molecular epidemiology of the disease, based on the amplification of a 2400 bp long fragment containing two duplicated gene coding for a putative membrane protein. The sequence of this fragment, obtained on 19 Mycoplasma capricolum subsp. capripneumoniae (Mccp) strains from various geographical locations, gave 11 polymorphic positions. The three mutations found on gene H2prim were silent and did not appear to induce any amino acid modifications in the putative translated protein. The second gene may be a pseudogene not translated in vivo, as it bore a deletion of the ATG codon found in the other members of the "Mycoplasma mycoides cluster" and as the six mutations evidenced in the Mccp strains would induce modifications in the translated amino acids. In addition, an Mccp strain isolated in the United Arab Emirates showed a deletion of the whole pseudogene, a further indication that this gene is not compulsory for mycoplasma growth. Four lineages were defined, based on the nucleotide sequence. These correlated relatively well with the geographical origin of the strains: North, Central or East Africa. The strain of Turkish origin had a sequence similar to that found in North African strains, while strains isolated in Oman had sequences similar to those of North or East African strains. The latter is possibly due to the regular import of goats of various origins. Similar molecular epidemiology tools have been developed by sequencing the two operons of the 16S rRNA gene or by AFLP. All these various techniques give complementary results. One (16S rRNA) offers the likelihood of a finer identification of strains circulating in a region, another (H2) of determining the geographical origin of the strains. These tools can make a very useful contribution to understanding the epidemiology of CCPP. 相似文献
849.
An 8-year-old, male, mongrel dog developed severe cough and anorexia and died within 3 months. Autopsy revealed an invasive grayish-white mass in the right kidney and multiple nodules in the lungs, thoracic wall, and spleen. Histologically, the renal mass and the other nodules were mainly composed of papillotubular structures lined by oval-to-polygonal pleomorphic cells. The cells were reactive with DBA, PNA, and UEA-1 lectins and positive for vimentin but negative for CD10 and high molecular weight cytokeratin. Because of its histological, histochemical, and immunohistochemical similarities with human collecting duct carcinoma (CDC), a diagnosis of renal collecting duct carcinoma with pulmonary, thoracic, and splenic metastases was established. To our knowledge, this is the first case report of CDC in animals. 相似文献
850.
Marco Pietra Renato Giulio Zanoni Angelo Peli Barbara Brunetti Nikolina Linta Ombretta Capitani Giuseppe Spinella 《Irish veterinary journal》2015,69(1):12