Mechanism of adipose tissue specific response to heat stress in pigs.

Heat stress (HS) is a major problem facing the swine industry all over the world, especially during the hot summer months. The two major reasons pigs are highly susceptible to elevated ambient temperature are that they have substantial subcutaneous fat layer that serves as a barrier against effective heat dissipation and their lack of functional sweat glands on their skin surface for evaporative heat loss. Paradoxically, HS results in increased fat deposition in pigs. However, the fundamental causes of the increased adiposity during HS are unknown. Therefore, we conducted several in vivo and in vitro experiments to elucidate the precise mechanisms of HS response in pig adipose tissue. In the first study, we used an in vitro adipocyte differentiation model to characterize cellular responses that occur during differentiation of pig adipocytes in HS. We found the existence of cell autonomous response to HS in pig adipocytes that results in increased adipocyte lipid storage. In the second study, we wanted to elucidate the mechanisms of HS management and their relationship to adipose tissue metabolism. Thirty cross-bred (Ossabaw × Duroc × Landrace) pigs (boars n=15, gilts n=15) were assigned to three treatments for 1 week: 1) control and libitum fed (CON) with environment temperature 20 °C ± 1 °C and ad libitum access to feed, 2) pair-fed (PF) with environment temperature 20 °C ± 1 °C and fed the amount same as HS pigs, 3) HS with environment temperature 35 °C ± 1 °C and ad libitum access to feed. Heat stress led to increased glyceroneogenesis accompanied by induction of phosphoenolpyruvate carboxykinase (PCK1) in adipose tissue without alteration of serum glucose, insulin, FFA and triglyceride concentrations and this revealed that glyceroneogenesis, perhaps through PCK1, plays an important role in increased adipose lipid storage under HS. In the third experiment, we used a commercial-type pig genotype, a Duroc × Yorkshire × Landrace terminal cross, to evaluate effects of both acute (24 h) and chronic (7 d) HS on gene expression responses in adipose and other peripheral tissues. The HS induced a robust adipose tissue response in favor of increased lipid storage. This indicates that adipose tissue might play an important role in HS adaptation, irrespective of the genotype of the pig. In the fourth study, the effect of PCK1 inhibition with 3 mercaptopicolinic acid (3MPA) on lipid storage and adipocyte response during HS was investigated. Inhibition of PCK1 during HS, adipocytes were less able to induce adaptive responses such as upregulation of HSP70 and triglycerides, and this exacerbated endoplasmic reticulum (ER) stress during HS. Therefore, PCK1 may function to alleviate ER stress that occurs during HS. In the fifth study, we wanted to determine global changes in adipose tissue and adipocyte metabolites and lipids species to see if they could serve as useful biomarkers that could be associated with HS adaptation response. Using metabolomics, lipidomics, and fatty acid profile analysis with gas chromatography, we found that HS induced distinct metabolite profiles. This may have implications for the explanation of the regulation of lipogenesis, fatty acid oxidation and membrane fluidity in adipose tissue during HS. Overall, these studies indicate a potential major role for PCK1 in the increased lipid storage during HS and in the suppression of ER stress that may occur in adipose tissue during HS. Thus, the increased lipid storage in adipose tissue during HS might be a protective mechanism against excessive ER stress and adipocyte death in this tissue

Thermodynamics and phase transition in central charge criticality of charged Gauss-Bonnet AdS black holes

In this paper, we investigate the thermodynamics of D-dimensional charged Gauss-Bonnet black holes in anti-de Sitter spacetime. Varying the cosmological constant, Newton constant and Gauss-Bonnet coupling constant in the bulk, one can rewrite the first law of thermodynamics for black holes. Furthermore, we introduce the central charge and study the critical behaviors, which show the apparent discrepancy from other black holes. Based on this approach, we disclose the phase transition structures in $D=4, 5$, and $6$. Besides, a triple point where the small/intermediate/large black holes can coexist is found in $D=6$

Cell surface-specific N-glycan profiling in breast cancer

Aberrant changes in specific glycans have been shown to be associated with immunosurveillance, tumorigenesis, tumor progression and metastasis. In this study, the N-glycan profiling of membrane proteins from human breast cancer cell lines and tissues was detected using modified DNA sequencer-assisted fluorophore-assisted carbohydrate electrophoresis (DSA-FACE). The N-glycan profiles of membrane proteins were analyzed from 7 breast cancer cell lines and MCF 10A, as well as from 100 pairs of breast cancer and corresponding adjacent tissues. The results showed that, compared with the matched adjacent normal tissue samples, two biantennary N-glycans (NA2 and NA2FB) were significantly decreased (p <0.0001) in the breast cancer tissue samples, while the triantennary glycan (NA3FB) and a high-mannose glycan (M8) were dramatically increased (p = 0.001 and p <0.0001, respectively). Moreover, the alterations in these specific N-glycans occurred through the oncogenesis and progression of breast cancer. These results suggested that the modified method based on DSA-FACE is a high-throughput detection technology that is suited for analyzing cell surface N-glycans. These cell surface-specific N-glycans may be helpful in recognizing the mechanisms of tumor cell immunologic escape and could be potential targets for new breast cancer drugs

Predicting student performance in interactive online question pools using mouse interaction features

Modeling student learning and further predicting the performance is a well-established task in online learning and is crucial to personalized education by recommending different learning resources to different students based on their needs. Interactive online question pools (e.g., educational game platforms), an important component of online education, have become increasingly popular in recent years. However, most existing work on student performance prediction targets at online learning platforms with a well-structured curriculum, predefined question order and accurate knowledge tags provided by domain experts. It remains unclear how to conduct student performance prediction in interactive online question pools without such well-organized question orders or knowledge tags by experts. In this paper, we propose a novel approach to boost student performance prediction in interactive online question pools by further considering student interaction features and the similarity between questions. Specifically, we introduce new features (e.g., think time, first attempt, and first drag-and-drop) based on student mouse movement trajectories to delineate students' problem-solving details. In addition, heterogeneous information network is applied to integrating students' historical problem-solving information on similar questions, enhancing student performance predictions on a new question. We evaluate the proposed approach on the dataset from a real-world interactive question pool using four typical machine learning models.Comment: 10 pages, 7 figures, conference lak20, has been accepted, proceeding now. link: https://lak20.solaresearch.org/list-of-accepted-paper

Flotation Characteristics and Particle Size Distribution of Micro-fine Low Rank Coal

AbstractIn this work, attempts to float the micro-fine low rank coal and its particle size distribution in the flotation were made. Then, standard screening, FT-IR, XRD and SEM were adopted to characterize the size distribution and flotation of micro-fine Shendong low rank coal. The results indicated that the size fraction of -0.045mm was the dominant size fraction in raw coal with a yield of 91.65% and ash content of 46.25%. Flotation of Shendong low rank coal required a larger dosage of collector, 50kg/t of diesel oil, to achieve a higher combustible matter recovery (63.25%) and flotation efficiency index (40.70%) accompanied with a significant decrease in ash content (22.44 percentage points) due to the hydrophilicity of coal surface. Under this condition, concentrate contained 83.38% of -0.045mm size fraction (38.04% of total particles in feed) with ash content of 24.98%. In comparison, tailing was almost consisted of -0.045mm fraction (93.63%) with a higher ash content of 60.82%. It seems that the higher ash particles in feed were largely migrated in tailing at a proper collector dosage. The analysis of FT-IR, XRD and SEM would contribute to the understanding of the flotation and size distribution