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31.
指出了随着信息技术,尤其是互联网的发展,人们生产数据的能力越来越强,爆炸性的增长数据充斥着整个网络。同时,中国也进入了大众度假旅游时代,酒店市场需求旺盛。通过大数据,可以准确预知旅客爱好取向,发展和优化景区酒店管理,改进酒店服务。利用网络爬虫、实地调研等技术从网站获取相关数据来进行大数据的收集、清洗优化、挖掘及整合研究分析,为酒店的动态定价、客户入住等提供参考。通过数据的统计分析、积累挖掘,对景区酒店进行细分市场、调整策略,更好地为旅客提供服务。  相似文献   
32.
中亚热带天然林改造成人工林后土壤呼吸的变化特征   总被引:1,自引:0,他引:1  
【目的】研究中亚热带常绿阔叶林(天然林)改造成人工林后土壤碳排放量的变化及主要影响因子,为评估森林类型转换对土壤碳排放的影响提供科学依据。【方法】在福建农林大学西芹教学林场的常绿阔叶林及由其改造而来的38年生闽楠人工林与35年生杉木人工林中分别设置4块20 m×20 m样地,利用Li-8100土壤碳通量观测系统于2014年9月—2016年9月进行定点观测,并同期观测土壤温度、含水量、有机碳含量(SOC)、微生物生物量碳含量(MBC)、可溶性有机碳含量(DOC)、0~20 cm土层细根生物量和年凋落物量及凋落物碳氮比(C/N)。【结果】常绿阔叶林改造成闽楠(38年后)和杉木人工林(35年后),年均土壤碳排放通量由16. 22显著降为12. 71和4. 83 tC·hm-2a-1,分别减少21. 60%和70. 20%;各林分类型的土壤呼吸温度敏感性Q10值表现为常绿阔叶林(1. 97)<闽楠人工林(2. 03)<杉木人工林(2. 91),转换为杉木人工林后,Q10值显著升高(P<0. 05);土壤温度能分别解释常绿阔叶林、闽楠人工林与杉木人工林土壤呼吸速率变化的89. 70%、88. 50%和87. 90%,土壤呼吸速率和土壤含水量相关不显著(P>0. 05);土壤呼吸速率和SOC、MBC、DOC、年凋落物量及0~20 cm土层细根生物量均极显著正相关(P<0. 01);土壤呼吸温度敏感性指数Q10值和凋落物C/N极显著正相关(P<0. 01),而与年均土壤呼吸速率及MBC极显著负相关(P<0. 01);进一步分析发现土壤MBC和SOC含量是影响土壤呼吸速率的2个最重要因子,而凋落物C/N在影响土壤呼吸温度敏感性中的贡献最大。【结论】中亚热带地区常绿阔叶林改造成闽楠(38年)或杉木(35年)人工林后,土壤碳排放通量显著降低。林分类型转换后树种组成和林分结构发生改变,凋落物数量、质量及细根生物量显著降低,土壤SOC和MBC含量显著下降可共同导致土壤呼吸通量的下降。土壤温度是3种林分类型土壤呼吸季节变化的主导因素,而土壤总有机碳库和土壤微生物量碳库的差异是不同林分之间土壤呼吸差异的主导因素,凋落物C/N对土壤呼吸的Q10影响最大。为提高模型预测森林类型转换影响土壤碳排放的精度,应综合考虑土壤有机碳库、易变性有机碳库及底物质量的变化。  相似文献   
33.
Anthocyanins richly exist in mulberry plants and have been well characterized to have various bioactive properties. However, the antimetastasis properties of mulberry anthocyanins (MACs) remain unclear. The objectives of this study were to investigate the inhibitory effects of MACs on the metastasis of B16-F1 cells under noncytotoxic concentrations. Further investigation revealed that the antimetastatic effect of MACs was also evident in a C57BL/6 mice model. First, MACs exhibited an inhibitory effect on the migration ability by wound healing assay and Boyden chamber assay. In the cancer cell metastasis process, matrix degrading proteinases are required. B16-F1 cells treated with MACs at various concentrations showed reduced extracellular matrix (ECM) proteinases including matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) by gelatin zymography assay. The results of the Western blotting assay demonstrated that the expression levels of Ras, phosphoinositide 3-kinase (PI3K), phospho-Akt, and nuclear factor kappa B (NF-kappaB) in the MACs-treated B16-F1 cells were reduced. Therefore, it was suggested that MACs could mediate B16-F1 cell metastasis by reduction of MMP-2 and MMP-9 activities involving the suppression of the Ras/PI3K signaling pathway. Besides, B16-F1 melanoma cells were also injected into the right groin of the C57BL/6 mice, and the mice were fed with MACs at the same time. The hematoxylin-eosin stain (H&E stain) and immunohistochemistry stain showed that the MACs inhibited the mtastasis of B16-F1 cells in vivo. Taken together, the findings proved the inhibitory effect of MACs on the growth and metastasis of B16-F1 cells. These results indicated that MACs might be offered for future application as an antimetastatic agent.  相似文献   
34.
为研究不同砧木嫁接对西瓜化感物质的缓解作用,以西瓜品种‘早佳84-24’为接穗,用2种葫芦(‘京欣砧’和‘砧秋’)和2种南瓜(‘日本雪松’和‘酒砧一号’)为砧木,探究4mmol·L-1浓度邻苯二甲酸二异丁酯(DIBP)和邻苯二甲酸二辛酯(DOP)处理下,不同砧木嫁接对西瓜幼苗根系生理特性及矿质元素含量的影响。结果表明:(1)4 mmol·L-1的DIBP和DOP处理下南瓜和葫芦嫁接苗的根长均长于自根苗,其中葫芦砧木具有更强的根系活力。(2)化感物质处理下4种嫁接苗的丙二醛(MDA)含量均显著降低,其中4 mmol·L-1 DIBP处理中4种嫁接苗均促进西瓜根系超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的提高,而在4 mmol·L-1 DOP处理下,仅葫芦砧木促进了3种抗氧化酶活性提高。(3)化感物质处理下4种砧木嫁接苗硝酸还原酶活性整体上均高于自根苗。(4)化感物质处理下不同嫁接西瓜苗根系对矿质元素吸收呈现不同规律,总的来说嫁接可以促进根系对元素(磷、钾、钙、镁)的吸收...  相似文献   
35.
Porcine haptoglobin (Hp) is an acute phase protein. Its plasma level increases significantly during inflammation and infection. One of the main functions of Hp is to bind free hemoglobin (Hb) and inhibit its oxidative activity. In the present report, we studied the Hp phenotype of Taiwanese Lanyu miniature pigs (TLY minipigs; n=43) and found their Hp structure to be a homodimer (beta-alpha-alpha-beta) similar to human Hp 1-1. Interestingly, Western blot and high performance liquid chromatographic (HPLC) analysis showed that 25% of the TLY minipigs possessed low or no plasma Hp level (<0.05 mg/ml). The Hp cDNA of these TLY minipigs was then cloned, and the translated amino acid sequence was analyzed. No sequences were found to be deficient; they showed a 99.7% identity with domestic pigs (NP_999165). The mean overall Hp level of the TLY minipigs (0.21 +/- 0.25 mg/ml; n=43) determined by enzyme-linked immunosorbent assay (ELISA) was markedly lower than that of domestic pigs (0.78 +/- 0.45 mg/ml; p<0.001), while 25% of the TLY minipigs had an Hp level that was extremely low (<0.05 mg/ml). In addition, the initial recovery rate (first 40 min) in the circulation of infused fluorescein isothiocyanate (FITC)-Hb was significantly higher in the TLY minipigs with extremely low Hp levels than those with high levels. This data suggests that the low concentration of Hp-Hb complex is responsible for the higher recovery rate of Hb in the circulation. TLY minipigs have been used as an experimental model for cardiovascular diseases; whether they can be used as a model for inflammatory diseases, with Hp as a marker, remains a topic of interest. However, since the Hp level varies significantly among individual TLY minipigs, it is necessary to prescreen the Hp levels of the animals to minimize variation in the experimental baseline. The present study may provide a reference value for future use of the TLY minipig as an animal model for inflammation-associated diseases.  相似文献   
36.
37.
Objective – To determine the accuracy and precision of an oscillometric noninvasive blood pressure device as a predictor of invasive direct blood pressure in healthy anesthetized hypotensive and normotensive dogs. Design – Prospective observational study. Setting – University teaching hospital. Animals – Eight crossbred adult dogs. Interventions – Anesthesia was induced with propofol and maintained with isoflurane. A catheter was placed in the dorsal pedal artery to record systolic, mean, and diastolic arterial blood pressures (aSAP, aMAP, and aDAP, respectively). The noninvasive blood pressure device cuff was placed around the contralateral front limb to record noninvasive systolic, mean, and diastolic blood pressure (nSAP, nMAP, and nDAP). Two states of blood pressure (BP) were studied: baseline state was established by keeping end‐tidal isoflurane concentration at 1.2±0.1%. The hypotensive state was achieved by maintaining the same isoflurane concentration while withdrawing approximately 40% of the animal's blood volume until aMAP was stable at approximately 40 mm Hg. At the end of the study, blood was returned to the animal and it was allowed to recover from anesthesia. Measurements and Main Results – Agreement between the direct and indirect BP measurements was determined by the Bland‐Altman method. The SAP and MAP but not DAP bias varied significantly between each BP state. Normotensive absolute biases (mean [SD]) for SAP, MAP, and DAP were ?14.7 mm Hg (15.5 mm Hg), ?16.4 mm Hg (12.1 mm Hg), and ?14.1 mm Hg (15.8 mm Hg), respectively. Absolute biases during the hypotensive state for SAP, MAP, and DAP were ?32 mm Hg (22.6 mm Hg), ?24.2 mm Hg (19.5 mm Hg), and ?16.8 mm Hg (17.2 mm Hg), respectively. Conclusion – The oscillometric device was not reliably predictive of intra‐arterial BP during hypotension associated with acute hemorrhage.  相似文献   
38.
Objective – To compare the placement feasibility and amount of bone trauma induced by 3 intraosseous (IO) access techniques in cats: an automatic impact penetration device (A), an automatic rotary insertion device (B), and a manual IO needle (C). Design – Prospective ex vivo study. Setting – University. Animals – Eighteen adult mixed breed feline cadavers. Interventions – Cadavers provided 72 total IO insertion locations divided equally between the right and left humerus and tibia. The 3 IO techniques were randomly allocated to these locations. Time to successful insertion, ease of insertion, and success rate were recorded. Each insertion site was analyzed for the number of bone fragments and defect diameter by computed tomography. Measurements and Main Results – Device B had lower time of insertion (P=0.01) compared with devices A and C. Device B had better ease of insertion scores (P<0.01) compared with devices A and C. No differences were detected between insertion sites (tibia versus humerus). No differences in the number of bone fragments, defect diameter, or success rate were detected among devices (P=0.06, 0.31, and 0.14, respectively). Conclusions – All 3 IO access methods evaluated yield acceptable results. Device B is significantly faster and easier to place in cat cadavers when compared with other methods.  相似文献   
39.
This study explored biostimulation mechanisms with an electron donor and a shuttle for accelerating pentachlorophenol (PCP) transformation in iron-rich soils. The results indicated that indigenous microbial communities are important for PCP transformation in soils. Biostimulation of indigenous microbial communities by the addition of lactate and anthraquinone-2,6-disulfonate (AQDS) led to the enhanced rates of PCP dechlorination by the dechlorinating- and iron-reducing bacteria in soils. The electrochemical studies using cyclic voltammograms and microbial current measurements confirmed the high reduction potential and the large amount of electrons generated under biostimulation conditions, which were responsible for the higher rates of PCP transformation. After biostimulation treatments by the additions of lactate and/or AQDS during PCP dechlorination processes, microbial community analysis by the terminal restriction fragment length polymorphism (T-RFLP) method showed the abundance terminal restricted fragments (T-RFs), an indicator of bacterial abundance, which represents the dechlorinating- and iron-reducing bacteria, suggesting their critical roles in PCP dechlorination in soils.  相似文献   
40.
Missing plants in potato crops can be caused by diseases and other factors, and can result from non-emergence or from plants incapacitated at any time during the growing season. Field experiments were conducted to simulate missing plants and to estimate the resulting yield losses by removing different percentages of plants at random from plots at emergence and/or later stages. The recorded yield losses were not proportional to the percentage of missing plants. Two surveys of fields of table stock and seed stock of the cultivar Netted Gem in New Brunswick in 1972 showed that approximately 25% of the plants were missing at emergence, probably causing around8% loss in total tuber yield. Assuming all cultivars have similar levels of misses, the yield loss clue to missing plants at emergence in New Brunswick in 1972 was equivalent to a financial loss of approximately $1 1/2 million.  相似文献   
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