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1.
Microblog is a social platform with huge user community and mass data. We propose a semantic recommendation mechanism based on sentiment analysis for microblog. Firstly, the keywords and sensibility words in this mechanism are extracted by natural language processing including segmentation, lexical analysis and strategy selection. Then, we query the background knowledge base based on linked open data(LOD) with the basic information of users. The experiment result shows that the accuracy of recommendation is within the range of 70%-89% with sentiment analysis and semantic query. Compared with traditional recommendation method, this method can satisfy users’ requirement greatly.  相似文献   

2.
Two strains of measles virus IMA and SMD that were isolated using B95a cell line show hemadsorption negative. After adaptation to Vero cells, these strains gain the ability to agglutinate AGM-RBC and show hemadsorption positive. Sequence analysis of these two kinds of virus reveals that the two strains all have a Ser (HAD negative) to Gly (HAD positive) mutation at position 546 in the H protein. Site-directed mutagenesis and expression in COS cells were used to confirm that the mutation Ser→Gly is responsible for hemadsorption alteration. Then the monoclonal antibody against CD46 was used to identify that this mutation also governs the binding function of MV H protein to CD46 receptor. The data provide a new important amino acid of MV H protein that governs the hemadsorption and binding to CD46 receptor.  相似文献   

3.
陈峰 《科技信息》2011,(8):133-136
In recent years,with the rapid development of the informational,the digital and audio-visual technology,multimedia technology and its application have also entered a new development era in people’s life,especially in the academic field.In China,Computer Assisted Language Learning(CALL) has a far-reaching influence on the reforming and modernization of the education,and has brought about a new revolution in foreign language teaching and learning.The study,by means of a self-designed questionnaire,conducted a survey of the application of CALL with 120 English majors and 30 English teachers in a certain higher vocational college which the author works in.The study hopes that,with the help of the technological advantages of CALL and the rich on-line information resources via computers,the students’ study could be carried out in a more effective and convenient way.The results of statistical analysis revealed that,the majority of the students and teachers hold a positive attitude toward CALL application in language teaching and learning,though they have reported some weaknesses of CALL.According to the analysis,the paper attempts to discuss the advantages and the disadvantages of multimedia technology in English teaching and suggests several proposals to better the use of CALL.  相似文献   

4.
In this paper, a parallel solution framework for the linear static analysis of large structures on PC clusters is presented. The framework consists of two main steps: data preparation and parallel solution. The parallel solution is performed by a substructure based method with direct solvers. The aim of the data preparation step is to create the best possible substructures so that the parallel solution time is minimized. An actual structural model was solved utilizing both homogeneous and heterogeneous PC clusters to illustrate the performance and applicability of the presented framework.  相似文献   

5.
An ERP study was conducted to explore the differences between other-relevant words and possessor-relevant words in implicit and explicit memory tests. The results show that other-relevant words are associated with a more negative ERP than possessor-relevant words during 300--900 ms whether in the implicit or the explicit memory tests. The N400 effect is also found in semantic processing of social materials. There is an ERP dissociation of retrieval formats between the implicit and the explicit memory tests during 700--900 ms, namely, there is no difference between other-relevant words and possessor-relevant words in the implicit memory while there is a significant difference between them in the explicit memory. Observed through Curry 6.0, the analysis of neural sources for other-relevant words and possessor-relevant words indicates that they have different locations. At 400 ms, activity is found in the left precuneus during possessor-relevant words processing. Both the right and the left precuneus are activated during other-relevant words processing. However, at 600 ms their location is both in the left precuneus. In a word, our results show that there exists a cognitive difference between other-relevant words and possessor-relevant words, and other-relevant words closely related to the percipient himself/herself are strongly responded to, which reflects that there is a bigger attention bias to the stimuli concerning the percipient himself/herself than to processor-relevant words.  相似文献   

6.
The use of genetically modified mosquitoes to reduce or replace field populations is a new strategy to control mosquito-borne diseases. The precondition of the implementation of this strategy is the ability to manipulate the genome of mosquitoes and to induce specific expression of the effector molecules driven by a suitable promoter. The objective of this study is to evaluate the expression of defensin A gene of Anopheles sinensis under the control of a vitellogenin promoter in transgenic Anopheles ste- phensi. The regulatory region of Anopheles gambiae vitellogenin was cloned and subcloned into transfer vector pSLFa consisting of an expression cassette with defensin A coding sequence. Then, the expression cassette was transferred into transformation vector pBac[3xP3-DsRedafm] using Asc I di- gestion. The recombinant plasmid DNA of pBac[3xP3DsRed-AgVgT2-DefA] and helper plasmid DNA of phsp-pBac were micro-injected into embryos of An. stephensi. The positive transgenic mosquitoes were screened by observing specific red fluorescence in the eyes of G1 larvae. Southern blot analysis showed that a single-copy transgene integrated into the genome of An. stephensi. RT-PCR analysis showed that the defensin A gene expressed specifically in fat bodies of female mosquitoes after a blood meal. Interestingly, the mRNA of defensin A is more stable compared with that of the endogenous vitellogenin gene. After multiple blood meals, the expression of defensin A appeared as a reducible and non-cycling type, a crucial feature for its anti-pathogen effect. From data above, we concluded that the regulatory function of the Vg promoter and the expression of defensin A gene were relatively con- served in different species of anopheles mosquitoes. These molecules could be used as candidates in the development of genetically modified mosquitoes.  相似文献   

7.
The quantitative detector of driver fatigue presents appropriate warnings and helps to prevent traffic accidents. The aim of this study was to quantifiably evaluate driver mental fatigue using the power spectral analysis of the blood pressure variability (BPV) and subjective evaluation. In this experiment twenty healthy male subjects were required to perform a driving simulator task for 3-hours. The physiological variables for evaluating driver mental fatigue were spectral values of blood pressure variability (BPV) including very low frequency (VLF), low frequency (LF), high frequency (HF). As a result, LF, HF and LF/HF showed high correlations with driver mental fatigue but not found in VLF. The findings represent a possible utility of BPV spectral analysis in quantitatively evaluating driver mental fatigue.  相似文献   

8.
Event-related potentials (ERPs) were used in this study to investigate the neural correlates of prospective memory (PM) and vigilance. Twenty college or graduate students participated in this study. They were administered a PM and a vigilance task and physiological data were collected at the same time. Behavioral results showed that the RT associated with PM cues was longer than those associated with vigilance targets. ERP results showed that PM cues and vigilance targets did not show significant difference in the N2 but PM cues evoked greater N300 than vigilance targets, and vigilance targets evoked greater parietal positivity/P3 than PM cues, suggesting vigilance and PM have similar but also distinctive neural basis.  相似文献   

9.
This study investigated the feature of Chinese peoples?perception of SARS by surveying a stratified sample of 4231 people from 17 cities in China, and primarily pro-posed a risk perception centered predictive model of psy-chological behavior in crisis. The results indicated that, negative SARS-related information, especially informationof personal interest, will arouse peoples risk perception ofhigh level, and lead to irrational nervousness or scare; but positive SARS-related information, including recovery in-formation and that with measures taken by government, can decrease the level of risk perception. In the middle of May, people felt the highest level of risk on the SARS pathogens; the following are the physical health condition and infectiv-ity after recovering from SARS; they are factors that needspecial attention. SEM result analyses supported our hy-potheses in that SARS-related information affect people抯coping behavior and mental health through their riskperception, the four indices of risk assessment, feeling ofnerv- ousness, coping behavior and mental health areeffective presentimental indices for public psychological behavior in risky events.  相似文献   

10.
High-density event-related potentials (ERPs) were measured when participants were required to evaluate oneself, significant others (father and mother) and the most familiar public figures (Lei Feng and Jiang Qing) based on trait adjectives. There were three referential conditions and a non-referential control condition including self-evaluation (SE), significant other-evaluation (SOE), general other-evaluation (GOE), and semantic positivity-evaluation (SPE). The behavioral data showed that RTs to GOE condition were longer than the other three conditions. Scalp ERP analysis revealed that (1) SPE condition elicited a more negative N2 than SE condition, which was associated with inhibition of responses; (2) SE condition elicited a more positive P300 than SPE condition, which was an index of attention to self-relevant stimuli; (3) there was no difference on the amplitude and latency of P300 between SE and SOE conditions, which reflected that the concept of “self” included intimate others (e.g., father and mother) in Chinese culture.  相似文献   

11.
High-density event-related potentials (ERPs) were measured when participants were required to evaluate oneself, significant others (father and mother) and the most familiar public figures (Lei Feng and Jiang Qing) based on trait adjectives. There were three referential conditions and a non-referential control condition including self-evaluation (SE), significant other-evaluation (SOE), general other-evaluation (GOE), and semantic positivity-evaluation (SPE). The behavioral data showed that RTs to GOE condition were longer than the other three conditions. Scalp ERP analysis revealed that (1) SPE condition elicited a more negative N2 than SE condition, which was associated with inhibition of responses; (2) SE condition elicited a more positive P300 than SPE condition, which was an index of attention to self-relevant stimuli; (3) there was no difference on the amplitude and latency of P300 between SE and SOE conditions, which reflected that the concept of “self” included intimate others (e.g., father and mother) in Chinese culture.  相似文献   

12.
Previous investigations suggest that ataxia is common and often one of the more reliable warning signs of HACE. The aim of this study was to investigate the diagnostic role of ataxia in acute mountain sickness (AMS) and high altitude cerebral edema (HACE) among mountain rescuers on the quake areas, and in approaching the relation between AMS and HACE. After the earthquake on April 14, 2010, approximately 24,080 lowland rescuers rapidly transported from sea level or lowlands to the mountainous rescue sites at 3 750m to 4 568 m, and extremely hardly worked for an emergency treatment after arrival. Assessments of acute altitude illness on the quake areas were using the Lake Louise Scoring System. Seventy-three percent of the rescuers were found to be developed AMS. The incidence of high altitude pulmonary edema (HAPE) and HACE was 0.73% and 0.26%, respectively, on the second to three day at altitude. Ataxia sign was measured by simple tests of coordination including a modified Romberg test. The clinical features of 62 patients with HACE were analyzed. It was found that the most frequent, serious neurological symptoms and signs were altered mental status (50/62, 80.6%) and truncal ataxia (47/62, 75.8 %), mental status change was rated slightly higher than ataxia, but ataxia occurred earlier than mental status change and other symptoms. The earliest sign of ataxia was a vague unsteadiness of gait, which may be present alone in association with or without AMS. Advanced ataxia was correlated with the AMS scores, but mild ataxia did not correlate with AMS scores at altitudes of 3 750-4 568 m. Of whom, 14 patients were further examined by computerized tomographic scanning of the brain and cerebral magnetic resonance imagines were examined in another 15 cases. These imaging studies indicated that the presence of the cerebral edema in 97 % of cases who clinically diagnosed as HACE (28/29). Ataxia seems a reliable sign of advanced AMS or HACE, as does altered mental status.  相似文献   

13.
The phytochrome gene from Microcystis aeruginosa FACHB-912,isolated from algal blooms in Taihu Lake in China,was sequenced and found to code for a wavelength transition light receptor protein.The gene was composed of five distinct domains:a PAS fold domain,a GAF domain,a phytochrome domain,a His Kinase A(phosphoacceptor) domain,and a histidine kinase domain.Red-absorbing phytochrome,far-red-absorbing phytochrome,and photoconversion kinetics were monitored via the spectral characteristics of the protein.To detect positive selection,homologous sequences from cyanobacterium phytochrome genes were obtained from GenBank.Potential selective pressure was identified by phylogenetic analysis with maximum likelihood analyses.The frequency of the phytochrome gene being subjected to selective constraints suggests that positive selection is a potentially important mechanism that promotes the evolution of the cyanobacteria phytochrome gene.The sites identified in this study provide targets for further research on the structural-functional role of these residues,and on the correlation with the mechanism of algal blooms.  相似文献   

14.
In this study, we investigated how the negative emotional arousal induced by watching a number of unpleasant images altered the concentration of secretory immunoglobulin A (SlgA) in saliva. Although our results found discrepancies among participants' SIgA concentration (i.e. some participants' SlgA decreased after watching unpleasant pictures, whereas others increased), further analysis revealed correlations among participants' changes in SIgA concentration, their general coping styles and their actual strategies for emotion regulation when perceiving unpleasant pictures, and the event-related potentials (ERPs) associated with viewing unpleasant pictures. The participants whose SIgA increased after watching unpleasant pictures (the "Increasers") had higher positive coping scores in the Trait Coping Styles Questionnaire (TCSQ) than those whose SIgA decreased (the "Decreasers"). Also, relative to the "Decreasers", the "Increasers" tended to use more emotion regulation strategies, particularly with extremely negative pictures. The amplitude of their late positive potentials (LPPs) exhibited a reverse dissociation pattern for extremely negative pictures versus least negative ones and was related to the cognitive evaluation of the stimuli's meaning. In sum, this research revealed the psychological mechanisms by which negative emotional states influence the immune system and the related ERP changes.  相似文献   

15.
The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching conditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a proportional relationship. A modified shrinking particle model was developed to account for the change in reactive surface area, and the model was fitted to experimental data. The resulting model was observed to describe experimental findings very well. Kinetics analysis revealed that the leaching process is controlled by a chemical reaction under the employed experimental conditions and the activation energy of the reaction is 48 kJ·mol-1.  相似文献   

16.
The interdecadal variation of coral grayness in northern South China Sea (SCS) is studied using the annual mean coral grayness in northern SCS from 1789 to 1992 and annual precipitation at Guangzhou from 1908 to 1992 by Singular Spectrum Analysis (SSA), correlation analysis, Mann-Kendalrs abrupt change analysis and composite analysis. The interdecadal variation of south China precipitation as reflected by the series of Guangzhou precipitation rebuilt with the coral grayness is discussed. The results show that the variation of coral grayness in SCS has significant terms of tendency, much-weighted interdecadal variation and weak interannual variation. There was a century-scale abrupt change of coral grayness at the end of the 1880s that changed from positive anomalies to negative anomalies. The global field of SST difference corresponding to the point of abrupt change was negative anomalies over the SCS and neighboring northern Indian Ocean, most of central and western Pacific Ocean and coastal areas of the northern Atlantic Ocean. The large-scale distribution of SST anomalies is concomitant with the century-scale abrupt change of coral grayness in SCS. Negative correlation exists between the coral grayness in SCS and precipitation in Guangzhou on the interdecadal scale and the interdecadal precipitation in Guangzhou as reflected by the interdecadal data of SCS coral grayness shows that the interdecadal variation of south China precipitation changes significantly from phase to phase. The current study aims at contributing in the effort of identifying alternative indexes for climate change in south China on the interdecadal scale and beyond.  相似文献   

17.
Current research on metaphor analysis is generally knowledge-based and corpus-based, which calls for methods of automatic feature extraction and weight calculation. Combining natural language processing(NLP), latent semantic analysis(LSA), and Pearson correlation coefficient, this paper proposes a metaphor analysis method for extracting the content words from both literal and metaphorical corpus, calculating correlation degree, and analyzing their relationships. The value of the proposed method was demonstrated through a case study by using a corpus with keyword "飞翔(fly)". When compared with the method of Pearson correlation coefficient, the experiment shows that the LSA can produce better results with greater significance in correlation degree. It is also found that the number of common words that appeared in both literal and metaphorical word bags decreased with the correlation degree. The case study also revealed that there are more nouns appear in literal corpus, and more adjectives and adverbs appear in metaphorical corpus. The method proposed will benefit NLP researchers to develop the required step-by-step calculation tools for accurate quantitative analysis.  相似文献   

18.
The DNA gyrase of Escherichia coli plays an essential role in the life of this microorganism.It is unique among all topoisomerases because of its ability to introduce negative supercoils into DNA.This study investigated the single molecular interaction of E.coli gyrase with DNA using magnetic tweezers.The results showed that,in the absence of ATP,gyrase weakly binds the G and T segments.The stretched force of 0.7 pN can gradually destroy the binding,whereas that of 5.9 pN directly destroys it.Addition of high concentrations of norfloxacin enhances gyrase binding to both segments,making them adapt to 5.9 pN.DNA gyrase reduces the plectonemic dimension,which was determined by the bacterial enzyme and not by the pull force.Moreover,it has different affinities for positive supercoils,which it prefers,and negative supercoils.The time distribution of the dissociation of gyrase from DNA has a double-exponential form.We herein propose a model to explain this distribution and compare the results with those of other models.  相似文献   

19.
In order to predict and improve the performance of matural gas/diesel dual fuel engine(DFE),a combustion rate model based on forward meural network was built to study the combustion process of the DFE.The effect of the operating parameters on combustion rate was also studied by means of this model.The study showed that the predicted results were good agreement with the experimental data.It was proved that the de-veloped combustion rate model could be used to successfully predict and optimize the combustion process of dual fuel engine.  相似文献   

20.
The present study investigated neural mechanisms of moral judgment of lying in adults using high-density event-related potentials (ERPs). Participants were recruited to do moral judgment of 200 stories including two types of lying and their corresponding truth-telling. The results showed that both types of lying were judged more negative than their corresponding truth-telling, and moral judgment of black lying was more negative than that of modest lying. There were two main components of the ERPs evoked by the test stimuli. One was an early component, peaking at about 200 ms, and the other was a late component, peaking at about 400 ms. Over the frontal scalp sites, the early component was positive and the late component was negative, while they both reversed over the posterior sites. The ERPs of both types of lying was more positive than that of their corresponding truth-telling in the time window of 600—900 ms at the posterior sites.  相似文献   

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