基于双模型融合的大熊猫头部图像分割

在大熊猫(Ailuropoda melanoleuca)的迁地保护和种群饲养管理中,及时、快速地进行个体识别和行为监测,对其健康管理具有至关重要的作用。圈养大熊猫健康状况通常由专门的饲养人员肉眼观测,人力成本高、效率低并且缺乏时效性。基于图像的动物个体识别与行为分析技术效率高、时间成本低,已经成为新的监测发展趋势。已有研究提出,通过大熊猫面部图像的检测和分析,可实现个体识别和行为分类。但该方法依然存在检测精度不足导致识别准确率难以提升的问题。本文提出一种基于YOLOv3和Mask R-CNN的双模型融合方法,实现了大熊猫头部图像分割和精准检测。包含3个部分：YOLOv3完成头部检测,Mask R-CNN完成大熊猫轮廓分割,然后将两个模型的输出进行交并比融合。结果显示,头部检测准确率为82.6%,大熊猫轮廓分割准确率为95.2%,总体头部轮廓分割准确率为87.1%。该方法对大熊猫头部图像的识别率和分割准确率高,为大熊猫的个体识别、性别分类提供了帮助,为行为分析提供了技术参考。     

Expression scoring of a small-nucleolar-RNA signature identified by machine learning serves as a prognostic predictor for head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy with high mortality and poor prognosis due to a lack of predictive markers. Increasing evidence has demonstrated small nucleolar RNAs (snoRNAs) play an important role in tumorigenesis. The aim of this study was to identify a prognostic snoRNA signature of HNSCC. Survival-related snoRNAs were screened by Cox regression analysis (univariate, least absolute shrinkage and selection operator, and multivariate). The predictive value was validated in different subgroups. The biological functions were explored by coexpression analysis and gene set enrichment analysis (GSEA). One hundred and thirteen survival-related snoRNAs were identified, and a five-snoRNA signature predicted prognosis with high sensitivity and specificity. Furthermore, the signature was applicable to patients of different sexes, ages, stages, grades, and anatomic subdivisions. Coexpression analysis and GSEA revealed the five-snoRNA are involved in regulating malignant phenotype and DNA/RNA editing. This five-snoRNA signature is not only a promising predictor of prognosis and survival but also a potential biomarker for patient stratification management.     

Efficient targeting of head and neck squamous cell carcinoma by systemic administration of a dual uPA and MMP-activated engineered anthrax toxin

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Although considerable progress has been made in elucidating the etiology of the disease, the prognosis for individuals diagnosed with HNSCC remains poor, underscoring the need for development of additional treatment modalities. HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both. Here we explored the use of an intercomplementing anthrax toxin that requires combined cell surface uPA and MMP activities for cellular intoxication and specifically targets the ERK/MAPK pathway for the treatment of HNSCC. We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis. Interestingly, the human HNSCC cell lines were insensitive to the intercomplementing toxin when cultured ex vivo, suggesting that either the toxin targets the tumor-supporting stromal cell compartment or that the tumor cell requirement for ERK/MAPK signaling differs in vivo and ex vivo. This intercomplementing toxin warrants further investigation as an anti-HNSCC agent.     

Power efficient virtual machine placement in cloud data centers with a discrete and chaotic hybrid optimization algorithm

Cluster Computing - Cloud computing is a new computation technology that provides services to consumers and businesses. The main idea of Cloud computing is to present software and hardware services...     

Conformational flexibility revealed by the crystal structure of a crenarchaeal RadA

Homologous recombinational repair is an essential mechanism for repair of double-strand breaks in DNA. Recombinases of the RecA-fold family play a crucial role in this process, forming filaments that utilize ATP to mediate their interactions with single- and double-stranded DNA. The recombinase molecules present in the archaea (RadA) and eukaryota (Rad51) are more closely related to each other than to their bacterial counterpart (RecA) and, as a result, RadA makes a suitable model for the eukaryotic system. The crystal structure of Sulfolobus solfataricus RadA has been solved to a resolution of 3.2 Å in the absence of nucleotide analogues or DNA, revealing a narrow filamentous assembly with three molecules per helical turn. As observed in other RecA-family recombinases, each RadA molecule in the filament is linked to its neighbour via interactions of a short β-strand with the neighbouring ATPase domain. However, despite apparent flexibility between domains, comparison with other structures indicates conservation of a number of key interactions that introduce rigidity to the system, allowing allosteric control of the filament by interaction with ATP. Additional analysis reveals that the interaction specificity of the five human Rad51 paralogues can be predicted using a simple model based on the RadA structure.     

ChooseMaterials.pl，控制变量挑选实验材料的perl脚本

用Perl语言编写了一个脚本--ChooseMaterials．pl,通过计算两个材料特定某几列数据之间增加或减少的百分数水平,达到控制变量突出关键因子的作用,方便生物学工作者选取材料,做进一步的实验或分析。     

Effect of airway wall flexibility on clearance by simulated cough

In our previous study, we investigated the relationship between mucus rheology, depth of mucus layer, and clearance by simulated cough. The purpose of the present study was to examine the effect of airway wall flexibility on the clearance of mucuslike gels. Transient airflows similar to cough were generated by both positive and negative pressure, the latter to mimic the dynamic compression that occurs during real cough. As in the previous study, the trachea was modeled as a trough of rectangular cross section with only the bottom lined with the mucus simulant. Clearance was followed by observing the displacement of marker particles. Since cough clearance is intimately related to wave formation in the mucus blanket, we hypothesized that clearance might be impeded if the wave formation occurred simultaneously in the wall and its lining layer. Thus, in one set of experiments the bottom rigid surface of the model trachea was replaced with a frame over which a flexible membrane could be drawn, whereas in the other set the rigid top was replaced by the frame. We also examined the effect of negative-pressure cough in excised canine tracheae, comparing the case where the tracheal membrane was free to deform vs. the case where it was secured. For the rigid-walled model, clearance by positive or negative pressure, with matched flow pattern, was the same. With the mucus simulant lining the flexible bottom surface, clearance increased with increasing membrane flexibility for negative-pressure cough and decreased for positive-pressure cough.(ABSTRACT TRUNCATED AT 250 WORDS)     

Discovery of a new insecticide lead by optimizing a target-diverse scaffold: tetrazolinone derivatives

In order to discover lead compounds with novel action mechanism, a series of tetrazolinone derivatives bearing structurally diverse substituents, 1-aryl-4-substituted-1,4-di-hydro-5H-tetrazol-5-ones 2, 1-((5-(alkylthio)-1,3,4-oxadiazol-2-yl)methyl)-4-(substituted)- phenyl-1H-tetrazol-5(4H)-ones 5, and 1-((5-(alkylthio)-1,3,4-thiadiazol-2-yl)methyl)-4- (substituted)phenyl-1H-tetrazol-5(4H)-ones 7, were designed and synthesized in good yields by a multiple-step synthetic procedure. The results of greenhouse in vivo test indicated that all the target compounds did not displayed herbicidal activity, however, some of them exhibited excellent in vivo insecticidal activity against Tetranychus cinnabarinus at the concentration of 250 mg L-1. To our knowledge, this is the first report about the insecticidal activity of tetrazolinone derivatives, which indicated that the tetrazolinone scaffold could be identified as a novel insecticidal lead structure. The present work demonstrated that optimizing a target-diverse scaffold is an effective way to discover new lead compounds with new action mechanism or biological activity.     

Domain structural flexibility in rhodanese examined by quenching of a phosphorescent probe

Rhodanese (thiosulfate:cyanide sulfurtransferase, EC 2.8.1.1) is an enzyme composed of two domains with the catalytic site located in the bottom of the crevice formed by the two domains. In this work, rhodanese was labeled at its catalytic site with the phosphorescence probe eosin isothiocyanide. The accessibility of molecules to the probe was determined by phosphorescence lifetime-quenching studies. The phosphorescent probe was much more accessible to small molecules (I- and thiosulfate, radius about 3-5 A) than to a larger molecule (spin-label probe TEMPO, radius about 8-10 A). It was observed that a temperature-induced change in the rate of quenching occurred at around 28 degrees C. The results are interpreted in terms of structural fluctuations and displacement in the domains.     

Plankton‐picking by the goatfish Pseudupeneus maculatus(Mullidae), a specialized bottom forager

Although goatfishes (Mullidae) include c . 50 specialized bottom foraging species, juvenile and adult spotted goatfish Pseudupeneus maculatus were recorded feeding on plankton on rocky reefs off southern and north‐eastern Brazil, respectively.     

A thermal-aware energy-efficient virtual machine placement algorithm based on fuzzy controlled binary gravitational search algorithm (FC-BGSA)

The remarkable growth of cloud computing applications has caused many data centers to encounter unprecedented power consumption and heat generation. Cloud providers share their computational infrastructure through virtualization technology. The scheduler component decides which physical machine hosts the requested virtual machine. This process is virtual machine placement (VMP) which, affects the power distribution, and thereby the energy consumption of the data centers. Due to the heterogeneity and multidimensionality of resources, this task is not trivial, and many studies have tried to address this problem using different methods. However, the majority of such studies fail to consider the cooling energy, which accounts for almost 30% of the energy consumption in a data center. In this paper, we propose a metaheuristic approach based on the binary version of gravitational search algorithm to simultaneously minimize the computational and cooling energy in the VMP problem. In addition, we suggest a self-adaptive mechanism based on fuzzy logic to control the behavior of the algorithms in terms of exploitation and exploration. The simulation results illustrate that the proposed algorithm reduced energy consumption by 26% in the PlanetLab Dataset and 30% in the Google cluster dataset relative to the average of compared algorithms. The results also indicate that the proposed algorithm provides a much more thermally reliable operation.

     

Functionality of Disintegrants and Their Mixtures in Enabling Fast Disintegration of Tablets by a Quality by Design Approach

Investigation of the effect of disintegrants on the disintegration time and hardness of rapidly disintegrating tablets (RDTs) was carried out using a quality by design (QbD) paradigm. Ascorbic acid, aspirin, and ibuprofen, which have different water solubilities, were chosen as the drug models. Disintegration time and hardness of RDTs were determined and modeled by executing combined optimal design. The generated models were validated and used for further analysis. Sodium starch glycolate, croscarmellose sodium, and crospovidone were found to lengthen disintegration time when utilized at high concentrations. Sodium starch glycolate and crospovidone worked synergistically in aspirin RDTs to decrease disintegration time. Sodium starch glycolate-crospovidone mixtures, as well as croscarmellose sodium-crospovidone mixtures, also decreased disintegration time in ibuprofen RDTs at high compression pressures as compared to the disintegrants used alone. The use of sodium starch glycolate in RDTs with highly water soluble active ingredients like ascorbic acid slowed disintegration, while microcrystalline cellulose and crospovidone drew water into the tablet rapidly and quickened disintegration. Graphical optimization analysis demonstrated that the RDTs with desired disintegration times and hardness can be formulated with a larger area of design space by combining disintegrants at difference compression pressures. QbD was an efficient and effective paradigm in understanding formulation and process parameters and building quality in to RDT formulated systems.KEY WORDS: disintegrants, quality by design, rapidly disintegrating tablets     

Epitope flexibility and dynamic footprint revealed by molecular dynamics of a pMHC-TCR complex

The crystal structures of unliganded and liganded pMHC molecules provide a structural basis for TCR recognition yet they represent 'snapshots' and offer limited insight into dynamics that may be important for interaction and T cell activation. MHC molecules HLA-B*3501 and HLA-B*3508 both bind a 13 mer viral peptide (LPEP) yet only HLA-B*3508-LPEP induces a CTL response characterised by the dominant TCR clonetype SB27. HLA-B*3508-LPEP forms a tight and long-lived complex with SB27, but the relatively weak interaction between HLA-B*3501-LPEP and SB27 fails to trigger an immune response. HLA-B*3501 and HLA-B*3508 differ by only one amino acid (L/R156) located on α2-helix, but this does not alter the MHC or peptide structure nor does this polymorphic residue interact with the peptide or SB27. In the absence of a structural rationalisation for the differences in TCR engagement we performed a molecular dynamics study of both pMHC complexes and HLA-B*3508-LPEP in complex with SB27. This reveals that the high flexibility of the peptide in HLA-B*3501 compared to HLA-B*3508, which was not apparent in the crystal structure alone, may have an under-appreciated role in SB27 recognition. The TCR pivots atop peptide residues 6-9 and makes transient MHC contacts that extend those observed in the crystal structure. Thus MD offers an insight into 'scanning' mechanism of SB27 that extends the role of the germline encoded CDR2α and CDR2β loops. Our data are consistent with the vast body of experimental observations for the pMHC-LPEP-SB27 interaction and provide additional insights not accessible using crystallography.     

Bacterivory in seawater samples estimated by a dual radioactive-labelling technique

A dual radioactive-labelled bacteria technique using Vibrio(DRLV), developed for laboratory studies on bacterivory, hasbeen refined for use at the concentrations of prey and predatorstypcially found at sea. Experiments with estuarine water collectedin spring and in autumn showed that bacterivorous nanoflagellates(HNF) (concentration 1.38±0.35x10³ HNF ml^–1) ingested2.7±0.96 DRLV flagellate1^–1 h^–1 at concentrationsof 0.8–2.2x10⁶ DRLV ml^–1 in the presence of 2.04±0.68x10⁶natural bacteria ml^–1. The method was also applied tosamples collected in October in the Celtic Sea, when on average1 ml of water from the surface layer contained 1.41±0.16x10⁶natural bacteria, 14.6x10³ cyanobacteria, 530±170 HNF,7.3±3.0x103 phototrophic nanoflagellates (1.5–4µm), 49.0±26.5 phototrophic dinoflagellates, 36.3±12.6heterotrophic dinoflagellates and 21.3±9.5 Leucocryptosmarina. Under these conditions the grazing rate in most samplesdid not exceed the coefficient of variation of the method (2%),although we estimate the grazing rate was -1.6 DRLV HNF^–1h^–1 and on one occasion a rate of 2.45 was recorded. Thegross growth efficiency for protein of -30% displayed by naturalHNF means that they could release about     

A unicellular walker controlled by a microtubule-based finite-state machine

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