A Novel Admission Control Model in Cloud Computing

With the rapid development of Cloud computing technologies and wide adopt of Cloud services and applications, QoS provisioning in Clouds becomes an important research topic. In this paper, we propose an admission control mechanism for Cloud computing. In particular we consider the high volume of simultaneous requests for Cloud services and develop admission control for aggregated traffic flows to address this challenge. By employ network calculus, we determine effective bandwidth for aggregate flow, which is used for making admission control decision. In order to improve network resource allocation while achieving Cloud service QoS, we investigate the relationship between effective bandwidth and equivalent capacity. We have also conducted extensive experiments to evaluate performance of the proposed admission control mechanism

Perceptual learning eases crowding by reducing recognition errors but not position errors

When an observer reports a letter flanked by additional letters in the visual periphery, the response errors (the crowding effect) may result from failure to recognize the target letter (recognition errors), from mislocating a correctly recognized target letter at a flanker location (target misplacement errors), or from reporting a flanker as the target letter (flanker substitution errors). Crowding can be reduced through perceptual learning. However, it is not known how perceptual learning operates to reduce crowding. In this study we trained observers with a partial-report task (Experiment 1), in which they reported the central target letter of a threeletter string presented in the visual periphery, or a whole-report task (Experiment 2), in which they reported all three letters in order. We then assessed the impact of training on recognition of both unflanked and flanked targets, with particular attention to how perceptual learning affected the types of errors. Our results show that training improved target recognition but not single-letter recognition, indicating that training indeed affected crowding. However, training did not reduce target misplacement errors or flanker substitution errors. This dissociation between target recognition and flanker substitution errors supports the view that flanker substitution may be more likely a byproduct (due to response bias), rather than a cause, of crowding. Moreover, the dissociation is not consistent with hypothesized mechanisms of crowding that would predict reduced positional errors

荆州区农村人口初发糖尿病胰岛功能的现状跟踪调查*

Objective: To study the change of islet function in patients with incipient diabetic characteristics through incipient diabetic tracking observation of the islet function in patients of Jingzhou area. Methods: Selection of 1220 cases of patients with diabetes mellitus in Jingzhou area as research object at the beginning, 12 months follow-up, the clinic after 3 months, 6 months and 12 months, all patients to detect blood sugar change, c-peptide release quantity, calculate insulin secretion index (HOMA -β) and insulin resistance index (HOMA IR), summarizes the characteristic of islet function in patients with changes. Results: ① The patients restored to basic standard blood sugar in 3 months by drug treatment, and the patient's blood glucose levels not seen obvious fluctuation after 6 months and 12 months; ② During follow-up, patients with diabetes sustained c-peptide release quantity reduction, and in three months after treatment, c-peptide release decreased obviously, and see a doctor at 6 months and 12 months after the comparison, the difference was statistically significant (P < 0.05). ③ During follow-up, insulin capacity was decreasing among patients with diabetes, within three months after the doctor had the greatest reduction, the difference was statistically significant (P < 0.05); ④ During follow-up, island hormone decreasing index, insulin resistance index continued to rise among patients with diabetes, and 6 months and 12 months, the most significant variations in 3 months (P < 0.05). Conclusion: With the extension of course, the pancreatic islet function in patients with early onset diabetes decreased gradually. It could be proved that there is a significant correlation between the two and especially seen in obvious function decline of pancreatic islets among the patients within 3 months.目的  通过对荆州区初发糖尿病患者的胰岛功能进行跟踪观察，探讨发现初发糖尿病患者胰岛功能的变化特点。方法  选取荆州区1220例初发糖尿病患者作为观察对象，跟踪随访12个月，在就诊后的3个月、6个月及12个月时，全部患者检测血糖变化、Ｃ-肽释放量，计算胰岛素分泌指数（HOMA-β）及胰岛素抵抗指数（HOMA-IR），观察总结患者的胰岛功能变化特点。结果  （1）通过药物治疗，患者血糖在3个月时基本达标，6个月及12个月时，患者的血糖水平未见明显波动；（2）随访期间，糖尿病患者Ｃ-肽释放量持续降低，且在就诊后3个月内，Ｃ-肽释放量下降明显，与就诊后6个月时及12个月时比较，差异有统计学意义（P＜0.05）。（3）随访期间，糖尿病患者胰岛素放量持续降低，就诊后3个月内下降最明显，差异有统计学意义（P＜0.05）；（4）随访期间，糖尿病患者胰岛素分泌指数持续降低，胰岛素抵抗指数持续升高，且与6个月时和12个月时比较，3个月时变化幅度最为显著（P＜0.05）。结论  随着病程的延长，初发糖尿病患者胰岛功能逐渐降低，二者具有显著相关性，且3个月内患者的胰岛功能下降最为显著

Physiological Hypoxia Enhances Stemness Preservation, Proliferation, and Bidifferentiation of Induced Hepatic Stem Cells

Induced hepatic stem cells (iHepSCs) have great potential as donors for liver cell therapy due to their self-renewal and bipotential differentiation properties. However, the efficiency of bidifferentiation and repopulation efficiency of iHepSCs is relatively low. Recent evidence shows that physiological hypoxia, a vital factor within stem cell “niche” microenvironment, plays key roles in regulating tissue stem cell biological behaviors including proliferation and differentiation. In this study, we found that physiological hypoxia (10% O2) enhanced the stemness properties and promoted the proliferation ability of iHepSCs by accelerating G1/S transition via p53-p21 signaling pathway. In addition, short-term hypoxia preconditioning improved the efficiency of hepatic differentiation of iHepSCs, and long-term hypoxia promoted cholangiocytic differentiation but inhibited hepatic differentiation of iHepSCs. These results demonstrated the potential effects of hypoxia on stemness preservation, proliferation, and bidifferentiation of iHepSCs and promising perspective to explore appropriate culture conditions for therapeutic stem cells

Experimental Study on the Absorption of Toluene from Exhaust Gas by Paraffin/Surfactant/Water Emulsion

A new paraffin/surfactant/water emulsion (PSW) for volatile organic compounds (VOCs) controlling was prepared and its potential for VOCs removal was investigated. Results indicated that PSW-5 (5%, v/v) provided higher toluene absorption efficiency (90.77%) than the other absorbents used. The saturation pressure, Henry’s constant, and activity coefficient of toluene in PSW-5 were significantly lower than those in water, and toluene solubility (1.331 g·L−1) in the PSW-5 was more than 2.5 times higher than the value in water. Several factors potentially affecting the toluene absorption efficiency were systematically investigated. The results suggested that concentration and pH of PSW, absorption temperature, and gas flow rate all had a strong influence on the toluene absorption, but the inlet concentration of toluene had little effect on the toluene absorption. There were different absorbing performances of PSW-5 on different VOCs, and the ketones, esters, and aromatics were more easily removed by the PSW-5 than the alkanes. Regeneration and reuse of the PSW were possible; after 3 runs of regeneration the absorption efficiency of PSW-5 for toluene also could reach 82.42%. So, the PSW is an economic, efficient, and safe absorbent and has a great prospect in organic waste gas treatment

Prediction of intraoperative cerebrospinal fluid leaks in endoscopic endonasal transsphenoidal pituitary surgery based on a deep neural network model trained with MRI images: a pilot study

ObjectiveThis study aimed to investigate the reliability of a deep neural network (DNN) model trained only on contrast-enhanced T1 (T1CE) images for predicting intraoperative cerebrospinal fluid (ioCSF) leaks in endoscopic transsphenoidal surgery (EETS).Methods396 pituitary adenoma (PA) cases were reviewed, only primary PAs with Hardy suprasellar Stages A, B, and C were included in this study. The T1CE images of these patients were collected, and sagittal and coronal T1CE slices were selected for training the DNN model. The model performance was evaluated and tested, and its interpretability was explored.ResultsA total of 102 PA cases were enrolled in this study, 51 from the ioCSF leakage group, and 51 from the non-ioCSF leakage group. 306 sagittal and 306 coronal T1CE slices were collected as the original dataset, and data augmentation was applied before model training and testing. In the test dataset, the DNN model provided a single-slice prediction accuracy of 97.29%, a sensitivity of 98.25%, and a specificity of 96.35%. In clinical test, the accuracy of the DNN model in predicting ioCSF leaks in patients reached 84.6%. The feature maps of the model were visualized and the regions of interest for prediction were the tumor roof and suprasellar region.ConclusionIn this study, the DNN model could predict ioCSF leaks based on preoperative T1CE images, especially in PAs in Hardy Stages A, B, and C. The region of interest in the model prediction-making process is similar to that of humans. DNN models trained with preoperative MRI images may provide a novel tool for predicting ioCSF leak risk for PA patients

Expression Patterns and Functions of Cardiac Pigment Epithelium-Derived Factor During Cardiac Development

Objective: This study describes the expression profiles and roles of cardiac pigment epithelium-derived factor (PEDF) during cardiac development. Methods: Gene datasets from the Gene Expression Omnibus (GEO) database were used to analyze the correlation between cardiac PEDF expression and heart disease. Western blotting, immunohistochemistry, histological staining and echocardiography were used to assess the expression patterns and functions of PEDF during cardiac development. Results: Analysis of GEO data sets indicated that the expression of cardiac PEDF correlated with the occurrence and development of various heart diseases. Western blotting of various tissues in mice at 30 postnatal days of age indicated higher PEDF expression in the heart and aorta than the liver. Immunohistochemical results demonstrated that the expression of cardiac PEDF significantly decreased after birth, mainly because of a significant decrease in PEDF expression in the cytoplasm. Histological staining and echocardiography indicated that PEDF deficiency had no significant effects on cardiac structure, cardiac function and vascular hemodynamics in 8-week-old mice. Conclusion: Cardiac PEDF shows high expression and dynamic changes during cardiac development, but has no effects on cardiac structure, function and vascular hemodynamics

Synchrotron Radiation Dominates the Extremely Bright GRB 221009A

The brightest Gamma-ray burst, GRB 221009A, has spurred numerous theoretical investigations, with particular attention paid to the origins of ultra-high energy TeV photons during the prompt phase. However, analyzing the mechanism of radiation of photons in the $\sim$MeV range has been difficult because the high flux causes pile-up and saturation effects in most GRB detectors. In this letter, we present systematic modeling of the time-resolved spectra of the GRB using unsaturated data obtained from Fermi/GBM (precursor) and SATech-01/GECAM-C (main emission and flare). Our approach incorporates the synchrotron radiation model, which assumes an expanding emission region with relativistic speed and a global magnetic field that decays with radius, and successfully fits such a model to the observational data. Our results indicate that the spectra of the burst are fully in accordance with a synchrotron origin from relativistic electrons accelerated at a large emission radius. The lack of thermal emission in the prompt emission spectra supports a Poynting-flux-dominated jet composition.Comment: 12 pages, 6 figures, 2 tables. Accepted for publication in ApJ

Genome-Wide Association Study for Femoral Neck Bone Geometry

Poor femoral neck bone geometry at the femur is an important risk factor for hip fracture. We conducted a genome-wide association study (GWAS) of femoral neck bone geometry, examining approximately 379,000 eligible single-nucleotide polymorphisms (SNPs) in 1000 Caucasians. A common genetic variant, rs7430431 in the receptor transporting protein 3 (RTP3) gene, was identified in strong association with the buckling ratio (BR, P = 1.6 × 10−7), an index of bone structural instability, and with femoral cortical thickness (CT, P = 1.9 × 10−6). The RTP3 gene is located in 3p21.31, a region that we found to be linked with CT (LOD = 2.19, P = 6.0 × 10−4) in 3998 individuals from 434 pedigrees. The replication analyses in 1488 independent Caucasians and 2118 Chinese confirmed the association of rs7430431 to BR and CT (combined P = 7.0 × 10−3 for BR and P = 1.4 × 10−2 for CT). In addition, 350 hip fracture patients and 350 healthy control individuals were genotyped to assess the association of the RTP3 gene with the risk of hip fracture. Significant association between a nearby common SNP, rs10514713 of the RTP3 gene, and hip fracture (P = 1.0 × 10−3) was found. Our observations suggest that RTP3 may be a novel candidate gene for femoral neck bone geometry. © 2010 American Society for Bone and Mineral Researc