Change of Behavior of \u3cem\u3eBos grunniens\u3c/em\u3e in the Alpine Rangeland in the Eastern Tibetan Plateau

Over 6 million yaks (Bos grunniens) are grazed in the alpine rangelands of the eastern Tibetan Plateau in Qinghai Province, China. Degradation of rangelands has been caused by increased numbers of domestic animals following the rise of the human population. In our previous study in northern and southern sites of Tibetan Plateau in Qinghai Province from 2003 to 2006, behavior of yaks and chemical composition of the faeces (Hasegawa et al. 2006; Hasegawa et al. 2008) and vegetation (Li et al. 2006; Song et al. 2006) were investigated and compared between the two sites, and it was suggested that the material circulation was lower and deterioration of rangeland was greater in the former than in the latter. In this study, behavioral observations of yaks in alpine rangeland of Yushu National Ranch from 2004 to 2012 were carried out to estimate the change of rangeland condition in the southern site of Tibetan Plateau

An Ecological Monitoring of the Plateau Pika and Its Impact on Grassland–An Experiment in the Yushu District, Qinghai Province of China

The plateau pika (Ochotona curzoniae; see Fig.1 for photo) is a small mammal that lives in the alpine grasslands of the Tibetan Plateau. There are several uncertainties existing in the ecological behavior of the plateau pika and its impact on the alpine grasslands, and this impact has long been a subject under discussion. The mammal will have created both positive and negative impacts to the plateau environment and the alpine ecology. In China the plateau pika is regarded as a pest and has been a target of control or extermination because it is a competitor with livestock for food.It also putatively destroys fragile high-altitude grasslands and accelerates the spread of deserts. On the other hand, some scientists have believed that the plateau pika is important for alpine grasslands and the ecology, by tilling the soil and also by functioning as a keystone species for biodiversity of the plateau. This paper summarizes a part of the pika’s behavior identified through the experiment conducted during the summer of 2012 in the Qinghai-Tibetan Plateau, China

Relationship between Soil Chemical and Physical Properties and Vegetation in the Latest Decade of Alpine Grasslands of Southern Qinghai, China

The Tibetan Plateau is one of the most important ecosystems in the world (Yang et al. 2009), particularly because of the global importance of its climate (Tian et al. 2008; Wang et al. 2008). Grassland ecosystems on the plateau are sensitive to global change, because the plateau is located in marginal land areas where the growth and distribution of plants depend heavily on local climatic conditions (Zhang et al. 1996). The alpine grassland of Qinghai Province in China has been traditionally used for extensive grazing by sheep and yak (Bos grunniens), but is now degraded from overgrazing. This study investigated the relationship between soil chemical and physical properties and vegetation of alpine grasslands of southern Qinghai, China

Ammonia Affects Mitochondrial Cell Apoptosis and Tenderness in Postmortem Yak Meat by Regulating Hypoxia Inducible Factor-1α Expression

This study aimed to investigate the effect of ammonia mediated hypoxia inducible factor-1α (HIF-1α) expression on mitochondrial cell apoptosis and tenderness in yak meat after slaughter. Ten mmol/L ammonium chloride (NH4Cl), 0.9% normal saline (control) and 10 mmol/L N-nitro-L-arginine methyl ester hydrochloride were used separately for treating yak Longissimus dorsi. By measuring the expression of HIF-1α, nitrogen monoxide (NO) content, energy metabolism-related enzyme activities, adenosine triphosphate (ATP) level, mitochondrial pathway of apoptosis and muscle tenderness, we explored the mechanism of cell apoptosis and tenderness change in yak meat after slaughter. The results showed that during the postmortem aging of yak meat, the expression of HIF-1α and the content of NO in each treatment group increased first and then decreased, and so did the activities of Na+-K+-ATPase, Ca2+-ATPase, caspase-9 and caspase-3 and shear stress. ATP content, the degree of mitochondrial permeability transition pore (MPTP) opening, mitochondrial membrane potential (MMP), and muscle fiber diameter and area showed a gradual downward trend, and myofibril fragmentation index (MFI) and the gap between muscle cells showed an opposite trend. During 6 to 24 h after slaughter, the expression of HIF-1α and the content of NO in the NH4Cl treatment group were significantly higher than those in the control group (P < 0.05), which were significantly higher than those in the L-NAME treatment group (P < 0.05). The ATP content in the NH4Cl group was significantly higher than that in the control and L-NAME groups during 6 to 72 h after slaughter. The activities of Na+-K+-ATPase and Ca2+-ATPase in the control group were significantly higher than those in the NH4Cl group (P < 0.05), but significantly lower than those in the L-NAME group (P < 0.05). During 6–120 h after slaughter, the opening of MPTP in the control group was significantly higher than that in the NH4Cl group (P < 0.05), but lower than that in the L-NAME group (P < 0.05). During 0 to 168 h after slaughter, the opening of MMP decreased by 47.72% in the NH4Cl group, 53.54% in the control group, and 60.05% in the L-NAME group. During 6 to 72 h after slaughter, the activities of caspase-9 and caspase-3 in the NH4Cl group were significantly lower than those in the control group (P < 0.05), which were lower than those in the L-NAME group (P < 0.05). During 6 to 120 h after slaughter, shear force and muscle fiber area and diameter in the NH4Cl group were higher than those in the control group, and MFI and the gap between muscle fibers in the NH4Cl group were lower than those in the control group, while the opposite result was observed for the L-NAME group. In conclusion, ammonia decreased the activities of Na+-K+-ATPase and Ca2+-ATPase and increased the content of ATP by up-regulating the expression of HIF-1α, which in turn regulated the energy metabolism of muscle cells and maintained the stability of the internal environment. By inhibiting the opening of MPTP and the decrease in MMP, ammonia reduced the activity of caspase-3/9, and inhibited mitochondrial cell apoptosis, thereby resulting in an increase in shear stress, a decrease in MFI and morphological changes of muscle cells, and finally causing a negative effect on the tenderness of yak meat

Study of the AMP-activated Protein Kinase Role in Energy Metabolism Changes during the Postmortem Aging of Yak Longissimus dorsal

To explore the postmortem physiological mechanism of muscle, activity of adenosine monophosphate activated protein kinase (AMPK) as well as its role in energy metabolism of postmortem yaks were studied. In this experiment, we injected 5-amino-1-beta-d-furanonyl imidazole-4-formamide (AICAR), a specific activator of AMPK, and STO-609 to observe the changes in glycolysis, energy metabolism, AMPK activity, and AMPK gene expression (PRKA1 and PRKA2) in postmortem yaks during maturation. The results showed that AICAR could increase the expression of the PRKKA1 and PRKAA2 genes, activate AMPK and increase its activity. The effects of AICAR include a lower concentration of ATP, an increase in AMP production, an acceleration of glycolysis, an increase in the lactic acid concentration, and a decrease in the pH value. In contrast, STO-609 had the opposite effect. Under hypoxic adaptation, the activity of the meat AMPK increased, which accelerated glycolysis and metabolism and more effectively regulated energy metabolism. Therefore, this study lays the foundation for establishing a theoretical system of energy metabolism in postmortem yak meat

Tumor-stroma Ratio is An Independent Prognostic Factor of Non-small Cell Lung Cancer

Background and objective The different expression of tumor-stroma ratio (TSR) have been proved to be a new and reliable independent prognostic factor in some solid tumors.The aim of the study is to test the different expression of TSR and its prognostic significance in non-small cell lung cancer (NSCLC). Methods A total of 73 patients who underwent surgery resection for NSCLC were included in this study. TSR was assessed visually on the hematoxylin-stained tissue sections of surgical specimens. Patients with more than 50% intratumor stroma were quantified as the stroma-rich group and those with less than 50% as the stroma-poor group. Results In 73 cases of tissue samples, 46 cases were included in the stroma-poor group, while 27 cases in stroma-rich group. The different expression of TSR in NSCLC tissue was not correlated with gender, age and pathological type, lymph node metastasis, tumor size, pTNM staging, and so on. Kaplan-Meier survival analysis showed that the different expression of TSR was significantly correlated with survival days (P=0.014). Cox regression analysis showed that not only different expression of TSR is a independent prognostic factor for NSCLC (HR=1.832, 95%CI: 1.017-3.299), but also pTNM staging (HR=1.953, 95%CI: 1.284-2.970). Conclusion The different expression of TSR might be an independent prognostic factor in NSCLC

Classification and Recognition Method for Yak Meat Parts Based on Improved Residual Network Model

ObjectiveConducting 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.MethodsFirstly, 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 front-end 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.ConclusionsThe 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

Failure Analysis of Thermal Corrosion Cycling of EB-PVD YSZ Thermal Barrier Coatings Exposed to Molten NaCl

NaCl is the most abundant salt in seawater, thermal barrier coatings (TBCs) face the challenge of chloride salt hot corrosion in the marine environment. In this work, we focus on evaluating the thermal corrosion cycling of 9 wt.% Y2O3-ZrO2 (YSZ) exposed to NaCl molten salt. YSZ was prepared by electron beam&ndash;physical vapor deposition (EB-PVD). The result showed that the thermal cycling life of YSZ coating in the presence of NaCl molten salt was significantly shortened. The shortening of the service life of the coating can be ascribed to the collective effects of the thickening of thermal growth oxide and the degradation of the bond coating