Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-09 Cooperative journals: 《中国生态农业学报》
Abstract：本文选取我国中亚热带杉木人工林土壤进行短期增温以及减少50%降雨试验, 利用光谱技术研究增温及减少降雨对土壤可溶性有机质(DOM)数量和结构的影响。试验设对照(CT)、增温(W, 土壤温度增高5℃)、减少降雨(P, 自然降雨量减少50%)、增温与减少降雨交互作用(WP)4 种处理。结果表明: 1)增温增加了土壤可溶性有机碳(DOC)数量,使DOM 的芳香性指数和腐殖化指数减小, 结构变得简单易于分解; 0~10 cm 土层的土壤DOM 含有较多的烷烃, 酯类物质较少; 10~20 cm土层的DOM则含有较多的碳水化合物。2)减少降雨使土壤水分相对减少, 土壤DOC的数量降低。0~10 cm土层土壤DOM的芳香性指数和腐殖化程度降低, DOM含有大量的烷烃; 而10~20 cm 土层土壤DOM的芳香性指数和腐殖化指数升高, 碳水化合物少。减少降雨处理使土壤可溶性有机氮(DON)数量增加。3)增温和减少降雨的交互作用增加了DOC 和DON 的数量, 降低了DOM 的芳香化程度和腐殖化程度; 使0~10 cm 土层的DOM 含有较多的碳水化合物, 而10~20 cm 土层的DOM 碳水化合物较少。4)对于0~10 cm 土壤, 增温对土壤DOM 的数量及结构的 作用最强; 随着土壤深度增加到10~20 cm, 减少降雨的作用逐渐明显, 其对DOM 结构的影响也达到显著水平。温度及降水对DOM 的数量及化学结构的变化具有重要意义, 该研究结果可以为阐释全球气候变化背景下土壤DOM 的动态周转及预测未来森林土壤碳氮的变化趋势提供科学依据。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-09 Cooperative journals: 《中国生态农业学报》
Abstract：本文选取我国中亚热带杉木人工林土壤进行短期增温以及减少50%降雨试验, 利用光谱技术研究增温及减少降雨对土壤可溶性有机质(DOM)数量和结构的影响。试验设对照(CT)、增温(W, 土壤温度增高5℃)、减少降雨(P, 自然降雨量减少50%)、增温与减少降雨交互作用(WP)4 种处理。结果表明: 1)增温增加了土壤可溶性有机碳(DOC)数量,使DOM 的芳香性指数和腐殖化指数减小, 结构变得简单易于分解; 0~10 cm 土层的土壤DOM 含有较多的烷烃, 酯类物质较少; 10~20 cm土层的DOM则含有较多的碳水化合物。2)减少降雨使土壤水分相对减少, 土壤DOC的数量降低。0~10 cm土层土壤DOM的芳香性指数和腐殖化程度降低, DOM含有大量的烷烃; 而10~20 cm 土层土壤DOM的芳香性指数和腐殖化指数升高, 碳水化合物少。减少降雨处理使土壤可溶性有机氮(DON)数量增加。3)增温和减少降雨的交互作用增加了DOC 和DON 的数量, 降低了DOM 的芳香化程度和腐殖化程度; 使0~10 cm 土层的DOM 含有较多的碳水化合物, 而10~20 cm 土层的DOM 碳水化合物较少。4)对于0~10 cm 土壤, 增温对土壤DOM 的数量及结构的 作用最强; 随着土壤深度增加到10~20 cm, 减少降雨的作用逐渐明显, 其对DOM 结构的影响也达到显著水平。温度及降水对DOM 的数量及化学结构的变化具有重要意义, 该研究结果可以为阐释全球气候变化背景下土壤DOM 的动态周转及预测未来森林土壤碳氮的变化趋势提供科学依据。
Subjects: Biology >> Ecology submitted time 2017-06-13 Cooperative journals: 《生态学报》
Abstract：丛枝菌根（arbuscular mycorrhiza，AM）共生体系对于植物适应各种逆境胁迫具有重要积极作用。AM真菌还能够通过根外菌丝网络调节植物群落结构和演替，深刻影响生态系统结构和功能的稳定性。AM真菌生态生理功能的发挥主要取决于其生态适应性，明确AM真菌在不同环境中的多样性、生态适应性以及对各种生态因子的响应机制，是AM真菌资源管理、功能发掘与利用的前提。迄今为止，有关各种生态因子对AM真菌多样性的影响已有不少研究，但是AM真菌生态分布及其形成机制仍缺乏系统的研究和理论分析。综述了生物因子和非生物因子对AM真菌生态分布的影响，结合大型生物空间分布理论探讨了AM真菌生态分布规律和建成机制，分析了当前本研究领域所存在的问题和动向，以期推动相关研究进展。
Subjects: Biology >> Ecology submitted time 2018-06-09 Cooperative journals: 《生态学报》
Abstract：在我国大力推动城市可持续发展，推进国家可持续发展实验区建设的同时，采用何种评估方法和数据开展城市可持续发展能力评估是需要重点解决的问题。近年来兴起的元数据理论与技术在解决评估数据质量控制方面被视为是一种行之有效的方法。针对我国现阶段使用的一些城市可持续发展能力评估指标体系的特点，通过深入剖析每一个指标数据的来源、获取手段、适用方法等特征，提出从软件工程学思路研发城市可持续发展能力评估元数据管理系统的具体方法，帮助可持续发展实验区高效获取和管理评估所需数据信息；以"十二五"科技支撑计划项目"城市可持续发展能力评估及信息管理关键技术研究与示范"中所建立的元数据规范，对其所包含的"数据发布日期"、"数据发布形式"、"空间范围"、"时间范围（起始时间、结束时间）"、"统计频率"、"数据安全限制分级"、"数据志说明"、"在线资源链接地址"和"数据统计单位信息（单位名称、联络人、联系电话、单位地址、邮件地址）"共14项为评估数据的关键元数据项，以此追踪对标的评估数据。并通过量化数据质量评分法针对数据质量在运用元数据追踪法前后的评价结果对比发现，被评估指标的数据质量在获得元数据支持时，其数据可靠性、可比性和可持续性方面的评价分值都获得了十分显著的改善。研究认为采用元数据理论在控制和保障城市可持续发展能力评估数据质量方面具有优势作用，开发有针对性的城市可持续发展能力评估元数据管理系统能够有效提高评估数据的综合评价结果。
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验以大肠杆菌型脂多糖(LPS)建立氧化应激模型，探讨了谷氨酰胺（GLN）对断奶仔猪氧化应激的影响。选用24头28日龄的健康三元（杜×长×大）断奶仔猪，随机分成3组，每组8个重复，每个重复1头猪。对照组和应激组饲喂基础饲粮，GLN组饲粮在基础饲粮中添加1% GLN，试验期为30 d。在试验第22、25、28和30天，应激组和GLN组仔猪分别按每千克体重腹腔注射100 μg LPS，对照组仔猪腹腔注射相同剂量的灭菌生理盐水，第30天进行前腔静脉采血并屠宰采取所需肠道样品，检测氧化应激相关指标。结果显示：1）LPS攻毒前各组血清抗氧化能力指标均无显著差异(P>0.05)。LPS攻毒后，应激组血清丙二醛(MDA)含量显著高于对照组(P<0.05)；GLN组血清MDA含量和超氧化物歧化酶(SOD)活性显著低于应激组和对照组(P<0.05)。2）LPS攻毒后，在十二指肠黏膜中，GLN组过氧化氢酶（CAT）和锌铜超氧化物歧化酶(CuZuSOD)基因相对表达量显著高于应激组(P<0.05)。在空肠黏膜中，GLN组CAT、锰超氧化物歧化酶(MnSOD)、谷胱甘肽过氧化物酶1(GPX1)和谷胱甘肽过氧化物酶4(GPX4)基因相对表达量显著高于对照组和应激组(P<0.05)，对照组GPX4基因相对表达量显著高于应激组(P<0.05)。在回肠黏膜中，GLN组和应激组CAT基因相对表达量显著低于对照组(P<0.05)，GPX4基因相对表达量显著高于对照组(P<0.05)；GLN组MnSOD基因相对表达量显著高于对照组和应激组(P<0.05)，CuZnSOD基因相对表达量显著高于对照组(P<0.05)。结果表明，GLN在一定程度上可以缓解断奶仔猪因LPS引起的氧化应激，以期为实际生产中减少氧化应激提供一定的理论基础。
Subjects: Psychology >> Social Psychology submitted time 2023-03-27 Cooperative journals: 《心理学报》
Abstract： Depressed students are at high-risk for suicide. Psychological pain, especially pain avoidance, was a more robust predictor for suicide ideation than depression at the behavioral level. Due to suicide as a complex classification model, machine learning algorisms applied to integrate behavioral data and neural characteristic can advance suicide prediction, and the accuracy of multimodality features is superior than clinical interview. The present study aimed to integrate data-driven machine learning algorisms and the three-dimensional psychological pain model to figure out the optimal features in the prediction of suicide ideation. Seventy-seven college students were recruited by advertisement and divided into three groups: depressed group with high levels of suicide ideation (HSI, n = 25), depressed group with low levels of suicide ideation (LSI, n = 20), and healthy controls (HC, n = 32). All participants completed the three-dimensional psychological pain scale (TDPPS), Beck depression inventory-I (BDI), Beck suicide ideation inventory (BSI), and the self-referential affective incentive delay task (SAID). The value of support vector based on machine-recursive feature elimination (RFE-SVM) algorithm applied to combine the scale scores, resting state and punitive-related EEG components for feature ranking in a nonlinear way. Results showed that: (1) Scores of pain avoidance in the HSI was higher than the LSI group. (2) The multimodal psychological pain-based model for suicide ideation classification (Accuracy = 85.66%, Precision = 0.82, Recall = 0.73, AUC = 0.92) was sufficient and superior than the EEG single-modal model. Importantly, the pain avoidance and BDI scores ranked the top two features in the classification model of suicide ideation, whereas painful feeling and pain arousal subscale scores ranked the top two features in the classification model of depression. The EEG optimal features of overlap in the pain avoidance and suicide ideation classification models were the LPP and target-P3 under self-referential punitive conditions. (3) The powers of delta and beta band were negatively correlated with the BSI-W and pain avoidance subscale scores. The FRN amplitude under other- and self-referential punitive conditions were negatively corelated with the pain avoidance subscale scores. In the HSI group, power of delta elicited by positive feedback under self-referential conditions was significantly lower than those under other-referential conditions. In the HSI group, the amplitude of LPP in other-referential punitive conditions was higher than those under reward and neutral conditions, whereas in the LSI group, the amplitude of LPP under self-referential punitive conditions was higher than that under neutral conditions. As a pilot study, the current study provided a support for the prominent role of pain avoidance and its related neuroelectrophysiological correlates in the prediction of suicide. The clinical significance of these results will be discussed.
Subjects: Biology >> Ecology submitted time 2018-05-10 Cooperative journals: 《生态学报》
Abstract：温度和水分影响森林生态系统的结构与功能，而全球变暖和降雨格局的改变是未来气候变化的趋势。我国中亚热带地区森林覆盖率大，碳库丰富，可溶性有机质（DOM）作为森林生态系统的重要组成部分，气候变化对它的数量和组成具有重要的影响。本文对我国湿润亚热带地区杉木人工林土壤进行模拟增温以及隔离50%的降雨试验，利用光谱技术手段研究增温及隔离降雨对土壤可溶性有机质（DOM）的数量及其结构的影响。试验设对照（CK）、增温（W）、隔离降雨（P）、增温与隔离降雨的交互作用（WP）4种处理。结果表明，与对照相比，土壤增温后，0-10cm和10-20cm土层的土壤可溶性有机碳（DOC）和可溶性有机氮（DON）增加，但其芳香性指数和腐殖化程度降低，增温加速DOM的流失，不利于土壤有机质的稳定。季节变化影响土壤的环境，导致隔离降雨有使DOM的数量增加或减少的趋势；在旱季（2014年10月和2015年1月），隔离降雨降低了土壤DOM的数量，但其芳香性指数和腐殖化程度增加，而进入雨季（2015年4月），隔离降雨有使DOM增加的趋势，但其组分中的芳香化合物较少。增温和隔离降雨的交互作用在一定程度上促进DOM的产生，其结构比对照简单。温度和降雨对DOM的影响较为复杂，在全球气候变化背景下，只有长期对其进行观测并探讨其他因素带来的影响才能深入了解气候变暖和降雨格局的变化对土壤碳、氮的影响。
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加谷氨酰胺（Gln）对断奶仔猪不同阶段生长性能的影响，以及其对脂多糖（LPS）诱导肠道损伤后断奶仔猪血清生化指标和生长性能的影响。选用24头28日龄健康的“杜×长×大”三元杂交断奶仔猪，随机分为3组，每组8个重复，每个重复1头猪。对照组和LPS组饲喂基础饲粮，Gln+LPS组饲喂添加了1%的外源性Gln的基础饲粮；在试验第22、25、28、30天，LPS组和Gln+LPS组腹腔注射100 μg/kg BW LPS，对照组则注射相同剂量的生理盐水。试验期30 d。结果表明：1）LPS处理前（试验第1~21天），与对照组相比，Gln+LPS组显著提高了试验第1~7天断奶仔猪的平均日采食量（ADFI）和平均日增重(ADG)（P0.05）。3）LPS组断奶仔猪的小肠长度显著低于对照组和Gln+LPS组（P0.05）。4）与对照组相比，Gln+LPS组断奶仔猪的血清高密度脂蛋白胆固醇（HDLC）含量和碱性磷酸酶（ALP）活性显著降低（P0.05）；Gln+LPS组和LPS组断奶仔猪的血清免疫球蛋白M（IgM）含量显著提高（P<0.05）。由此可见，饲粮中添加1%的Gln能够显著提高仔猪断奶后第1~7天的生长性能，之后效果不明显。饲粮中添加1%的Gln能够调节应激仔猪的血清生化指标，改善其生长性能和小肠长度，从而缓解仔猪断奶应激。
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2023-08-14 Cooperative journals: 《智慧农业（中英文）》
Abstract： [Objective] Conducting research on the recognition of yak meat parts can help avoid confusion and substandard parts during the production and sales of yak meat, improve the transparency and traceability of the yak meat industry, and ensure food safety. To achieve fast and accurate recognition of different parts of yak meat, this study proposed an improved residual network model and developed a smartphone based yak meat part recognition software. [Methods] Firstly, the original data set of 1960 yak tenderloin, high rib, shank and brisket were expanded by 8 different data enhancement methods, including horizontal flip, vertical flip, random direction rotation 30°, random direction rotation 120°, random direction rotation 300° , contrast adjustment, saturation adjustment and hue adjustment. After expansion, 17,640 yak meat images of different parts were obtained. The expanded yak meat images of different parts were divided according to the 4:1 ratio, resulting in 14,112 yak meat sample images in the training set and 3528 yak meat sample images in the test set. Secondly, the convolutional block attention module (CBAM) was integrated into each residual block of the original network model to enhance the extraction of key detail features of yak images in different parts. At the same time, introducing this mechanism into the network model could achieve greater accuracy improvement with less computational overhead and fewer parameters. In addition, in the original network model, the full connection layer was directly added after all residual blocks instead of global average pooling and global maximum pooling, which could improve the accuracy of the network model, prevent overfitting, reduce the number of connections in subsequent network layers, accelerate the execution speed of the network model, and reduce the computing time when the mobile phone recognized images. Thirdly, different learning rates, weight attenuation coefficients and optimizers were used to verify the influence of the improved ResNet18_CBAM network model on convergence speed and accuracy. According to the experiments, the stochastic gradient descent (SGD) algorithm was adopted as the optimizer, and when the learning rate was 0.001 and the weight attenuation coefficient was 0, the improved ReaNet18_CBAM network model had the fastest convergence speed and the highest recognition accuracy on different parts of yak data sets. Finally, the PyTorch Mobile module in PyTorch deep learning framework was used to convert the trained ResNet18_CBAM network model into TorchScript model and saved it in *.ptl. Then, the yak part recognition App was developed using the Android Studio development environment, which included two parts: Front-end interface and back-end processing. The frontend of the App uses *.xml for a variety of price control layout, and the back-end used Java language development. Then TorchScript model in *.ptl was used to identify different parts of yak meat. [Results and Discussions] In this study, CBAM, SENet, NAM and SKNet, four popular attentional mechanism modules, were integrated into the original ResNet18 network model and compared by ablation experiments. Their recognition accuracy on different parts of yak meat dataset were 96.31%, 94.12%, 92.51% and 93.85%, respectively. The results showed that among CBAM, SENet, NAM and SKNet, the recognition accuracy of ResNet18 CBAM network model was significantly higher than that of the other three attention mechanism modules. Therefore, the CBAM attention mechanism module was chosen as the improvement module of the original network model. The accuracy of the improved ResNet18_CBAM network model in the test set of 4 different parts of yak tenderloin, high rib, shank and brisket was 96.31%, which was 2.88% higher than the original network model. The recognition accuracy of the improved ResNet18_CBAM network model was compared with AlexNet, VGG11, ResNet34 and ResNet18 network models on different parts of yak test set. The improved ResNet18_CBAM network model had the highest accuracy. In order to verify the actual results of the improved ResNet18_CBAM network model on mobile phones, the test conducted in Xining beef and mutton wholesale market. In the actual scenario testing on the mobile end, a total of 54, 59, 51, and 57 yak tenderloin, high rib, shank and brisket samples were collected, respectively. The number of correctly identified samples and the number of incorrectly identified samples were counted respectively. Finally, the recognition accuracy of tenderloin, high rib, shank and brisket of yak reached 96.30%, 94.92%, 98.04% and 96.49%, respectively. The results showed that the improved ResNet18_CBAM network model could be used in practical applications for identifying different parts of yak meat and has achieved good results. [Conclusions] The research results can help ensure the food quality and safety of the yak industry, improve the quality and safety level of the yak industry, improve the yak trade efficiency, reduce the cost, and provide technical support for the intelligent development of the yak industry in the Qinghai-Tibet Plateau region.
Subjects: Biology >> Zoology submitted time 2017-11-07 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究α–酮戊二酸(AKG)和大蒜素对生长猪生长性能、养分表观消化率、血清生化指标以及肠道形态结构的影响。选用40头初始平均体重为(30.64±1.35) kg的健康三元(杜×长×大)杂交生长猪，按体重相近、性别比例相同原则随机分为5组，每组8个重复，每个重复1头猪。5组试验猪分别饲喂无抗基础饲粮(对照组)、无抗基础饲粮+25 mg/kg抗生素(Ⅰ组)、无抗基础饲粮+1%AKG(Ⅱ组)、无抗基础饲粮+0.5%大蒜素(Ⅲ组)、无抗基础饲粮+1%AKG+0.5%大蒜素(Ⅳ组)。预试期7 d，正试期21 d。结果表明：1）与对照组相比，Ⅰ组和Ⅳ组生长猪的平均日增重分别提高了10.80%和9.91%，但差异不显著(P>0.05)。2）与对照组相比，Ⅱ组钙的表观消化率显著提高(P0.05)，血清AST和ALT活性显著提高(P<0.05)。4）与对照组相比，Ⅳ组回肠绒毛高度及空肠和回肠的绒毛高度/隐窝深度值显著提高(P<0.05)。5）与对照组相比，Ⅳ组回肠中杯状细胞和淋巴细胞数目显著增加(P<0.05)。综上，无抗饲粮中联合添加1%AKG和0.5%大蒜素可通过改善肠道形态结构，提高对粗蛋白质、钙和磷等养分的消化吸收能力，促进肠道健康，进而改善生长猪的生长性能。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究低蛋白质饲粮添加α–酮戊二酸(α-ketoglutarate，AKG)对生长猪氮以及钙、磷代谢的影响。试验选用初始体重为（34.98±2.18） kg的健康三元杂交（杜×长×大）猪18头，按体重相近、性别比例相同原则随机分为3组，每组6个重复，每个重复1头。各组AKG的添加水平分别为0（对照组）、1%和2%。先进行为期14 d的饲养试验，观察生长性能；然后进行消化代谢试验，试验期为7 d，前5 d为预试期，后2 d为粪尿收集期（全收粪法）。结果表明：1）1%AKG添加组有改善35～45 kg生长猪生长性能的趋势，具体表现为提高平均日增重（P=0.194 2）和平均日采食量（P=0.258 3），降低料重比（P=0.419 7）。2）随着AKG添加水平提高，尿氮含量有下降趋势（P=0.143 2），粪氮、总氮含量及总氮排放率极显著降低（P0.05）。由此可见，在35～45 kg的生长猪饲粮中添加1%～2%AKG可有效降低机体氮、钙、磷排放，提高氮及钙、磷的利用率和日增重。
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-07 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To investigate the effect of high-intensity focused ultrasound (HIFU) on tumor metastasis in mouse model bearing melanoma xenograft. Methods Mice bearing murine melanoma B16-F10 cell xenograft were randomized for sham-HIFU or HIFU exposure when the tumors grew to a maximum diameter of 7-10 mm, and the tumor size was measured every 3 days. The cumulative survival rate of the mice and tumor metastasis rate were calculated, and the circulating melanoma cells were detected using qRT-PCR. At 14 days after HIFU treatment, B16-F10 cells were retransplanted via the tail vein and the pulmonary metastatic nodules were counted. Results The median survival time of the mice was 19.00 days (95% CI 17.14-20.86 days) in the sham group and 26.00 days (95%CI 24.76-27.25 days) in HIFU group. The cumulative survival rate in the HIFU group was significantly higher than that in sham-HIFU group (P<0.01), and the tumor size was significantly smaller in HIFU group at 20, 23, and 26 days after HIFU treatment (P<0.05). Compared with the sham-HIFU group, HIFU group had significantly lower levels of MAGE-A3, MART1 and PAX3 at 7 days after HIFU (P<0.05) with still lower MAGE-A3 level at 14 days (P<0.05). HIFU group showed a significantly smaller number of pulmonary metastatic nodules following tumor cell retransplantation than in sham-HIFU group (P<0.01) with a metastasis inhibition rate of 42.4%. Conclusion HIFU treatment can inhibit tumor metastasis in melanoma-bearing mice possibly by reducing tumor cell detachment from the primary tumor site and suppressing colonization of the circulating melanoma cells.
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