Overlapping approach Proton Pump Inhibitors/Nux vomica-Heel as new intervention for gastro-esophageal reflux management:Delphi consensus study

BACKGROUND Gastro-esophageal reflux disease(GERD)may affect the upper digestive tract;up to 20%of population in Western nations are affected by GERD.Antacids,histamine H2-receptor antagonists,and Proton Pump Inhibitors(PPIs)are considered the referring medications for GERD.Nevertheless,PPIs must be managed carefully because their use,especially chronic,could be linked with some adverse effects.An effective and safe alternative pharmacological tool for GERD is needed.After the identification of potentially new medications to flank PPIs,it is mandatory to revise and improve good clinical practices even through a consensus process.AIM To optimize diagnosis and treatment guidelines for GERD through a consensus based on Delphi method.METHODS The availability of clinical studies describing the action of the multicomponent/multitarget medication Nux vomica-Heel,subject of the consensus,is the basic prerequisite for the consensus itself.A modified Delphi process was used to reach a consensus among a panel of Italian GERD specialists on the overlapping approach PPIs/Nux vomica-Heel as a new intervention model for the management of GERD.The Voting Consensus group was composed of 49 Italian Medical Doctors with different specializations:Gastroenterology,otolaryngology,geriatrics,and general medicine.A scientific committee analyzed the literature,determined areas that required investigation(in agreement with the multiple-choice questionnaire results),and identified two topics of interest:(1)GERD disease;and(2)GERD treatment.Statements for each of these topics were then formulated and validated.The Delphi process involved two rounds of questioning submitted to the panel experts using an online platform.RESULTS According to their routinary GERD practice and current clinical evidence,the panel members provided feedback to each questionnaire statement.The experts evaluated 15 statements and reached consensus on all 15.The statements regarding the GERD disease showed high levels of agreement,with consensus ranging from 70%to 92%.The statements regarding the GERD treatment also showed very high levels of agreement,with consensus ranging from 90%to 100%.This Delphi process was able to reach consensus among physicians in relevant aspects of GERD management,such as the adoption of a new approach to treat patients with GERD based on the overlapping between PPIs and Nux vomica-Heel.The consensus was unanimous among the physicians with different specializations,underlying the uniqueness of the agreement reached to identify in the overlapping approach between PPIs and Nux vomica-Heel a new intervention model for GERD management.The results support that an effective approach to deprescribe PPIs through a progressive decalage timetable(reducing PPIs administration to as-needed use),should be considered.CONCLUSION Nux vomica-Heel appears to be a valid opportunity for GERD treatment to favor the deprescription of PPIs and to maintain low disease activity together with the symptomatology remission.

Large-Scale Multi-Objective Optimization Algorithm Based on Weighted Overlapping Grouping of Decision Variables

The large-scale multi-objective optimization algorithm(LSMOA),based on the grouping of decision variables,is an advanced method for handling high-dimensional decision variables.However,in practical problems,the interaction among decision variables is intricate,leading to large group sizes and suboptimal optimization effects;hence a large-scale multi-objective optimization algorithm based on weighted overlapping grouping of decision variables(MOEAWOD)is proposed in this paper.Initially,the decision variables are perturbed and categorized into convergence and diversity variables;subsequently,the convergence variables are subdivided into groups based on the interactions among different decision variables.If the size of a group surpasses the set threshold,that group undergoes a process of weighting and overlapping grouping.Specifically,the interaction strength is evaluated based on the interaction frequency and number of objectives among various decision variables.The decision variable with the highest interaction in the group is identified and disregarded,and the remaining variables are then reclassified into subgroups.Finally,the decision variable with the strongest interaction is added to each subgroup.MOEAWOD minimizes the interactivity between different groups and maximizes the interactivity of decision variables within groups,which contributed to the optimized direction of convergence and diversity exploration with different groups.MOEAWOD was subjected to testing on 18 benchmark large-scale optimization problems,and the experimental results demonstrate the effectiveness of our methods.Compared with the other algorithms,our method is still at an advantage.

Overlapping infections of Mycobacterium canariasense and Nocardia farcinica in an immunocompetent patient:A case report

BACKGROUND Infections by non-tuberculous mycobacteria(NTM)have become more common in recent years.Mycobacterium canariasense(M.canariasense)was first reported as an opportunistic pathogen in 2004,but there have been very few case reports since then.Nocardia is a genus of aerobic and Gram-positive bacilli,and these species are also opportunistic pathogens and in the Mycobacteriales order.Conventional methods for diagnosis of NTM are inefficient.Metagenomic next-generation sequencing(mNGS)can rapidly detect many pathogenic microorganisms,even rare species.Most NTM and Nocardia infections occur in immunocompromised patients with atypical clinical symptoms.There are no previous reports of infection by M.canariasense and Nocardia farcinica(N.farcinica),especially in immunocompetent patients.This case report describes an immunocompetent 52-year-old woman who had overlapping infections of M.canariasense,N.farcinica,and Candida parapsilosis(C.parapsilosis)based on mNGS.CASE SUMMARY A 52-year-old woman presented with a productive cough and chest pain for 2 wk,and recurrent episodes of moderate-grade fever for 1 wk.She received antibiotics for 1 wk at a local hospital,and experienced defervescence,but the productive cough and chest pain persisted.We collected samples of a lung lesion and alveolar lavage fluid for mNGS.The lung tissue was positive for M.canariasense,N.farcinica,and C.parapsilosis,and the alveolar lavage fluid was positive for M.canariasense.The diagnosis was pneumonia,and application of appropriate antibiotic therapy cured the patient.CONCLUSION Etiological diagnosis is critical for patients with infectious diseases.mNGS can identify rare and novel pathogens,and does not require a priori knowledge.

The Practical Path of Labor Curriculum in Compulsory Education in China from the Perspective of Overlapping Influence Domain Theory

Since the new curriculum reform,labor education has gradually shed its marginalized position in the“five educations,”and the labor curriculum has become an independent course officially separated from comprehensive practical activity courses.Exploring the practical path of labor curriculum in compulsory education in China has become the primary task of labor education in China.Based on the practical situation of labor curriculum in compulsory education in China,drawing on the theory of overlapping influence domains,and from the perspective of collaborative education among family,school,and community,this paper proposes a curriculum practical path of“school-led”family-school-community collaboration and a curriculum practical path guided by“student-centered”sentiment,in order to provide references for the practice of labor curriculum in compulsory education in China.

Overlap吻合与π吻合在全腹腔镜全胃切除术中的应用

目的:比较Overlap吻合与π吻合在全腹腔镜全胃切除术(TLTG)中的应用效果。方法:选择2019年2月至2022年2月在成都市第五人民医院行TLTG的胃癌患者98例,根据食管空肠吻合方式分为Overlap吻合组(n=56)和π吻合组(n=42)。比较两组围手术期指标(手术时间、吻合时间、术中出血量、淋巴结清扫数目、术后肛门排气时间、术后拔除引流管时间、术后住院时间、肿瘤上缘至食管切缘距离),吻合口相关并发症(吻合口出血、吻合口狭窄、吻合口漏)与随访并发症(吻合口溃疡、倾倒综合征、反流性食管炎、营养不良)发生情况,以及术前与术后3个月整体营养状况主观评估量表(PG-SGA)评分与营养状况客观指标(血红蛋白、白蛋白、总蛋白)水平的变化。结果:Overlap吻合组手术时间[(230.36±25.12)min vs(205.58±20.43)min]、吻合时间[(43.22±6.15)min vs(27.45±5.36)min]均长于π吻合组(P<0.05);两组吻合口相关并发症、随访并发症发生率及术前、术后3个月PG-SGA量表评分与营养状况客观指标水平的变化差异均无统计学意义(P>0.05)。结论:Overlap吻合和π吻合在TLTG术中各有优势,π吻合可缩短手术时间和吻合时间。

An Imbalanced Dataset and Class Overlapping Classification Model for Big Data

Most modern technologies,such as social media,smart cities,and the internet of things(IoT),rely on big data.When big data is used in the real-world applications,two data challenges such as class overlap and class imbalance arises.When dealing with large datasets,most traditional classifiers are stuck in the local optimum problem.As a result,it’s necessary to look into new methods for dealing with large data collections.Several solutions have been proposed for overcoming this issue.The rapid growth of the available data threatens to limit the usefulness of many traditional methods.Methods such as oversampling and undersampling have shown great promises in addressing the issues of class imbalance.Among all of these techniques,Synthetic Minority Oversampling TechniquE(SMOTE)has produced the best results by generating synthetic samples for the minority class in creating a balanced dataset.The issue is that their practical applicability is restricted to problems involving tens of thousands or lower instances of each.In this paper,we have proposed a parallel mode method using SMOTE and MapReduce strategy,this distributes the operation of the algorithm among a group of computational nodes for addressing the aforementioned problem.Our proposed solution has been divided into three stages.Thefirst stage involves the process of splitting the data into different blocks using a mapping function,followed by a pre-processing step for each mapping block that employs a hybrid SMOTE algo-rithm for solving the class imbalanced problem.On each map block,a decision tree model would be constructed.Finally,the decision tree blocks would be com-bined for creating a classification model.We have used numerous datasets with up to 4 million instances in our experiments for testing the proposed scheme’s cap-abilities.As a result,the Hybrid SMOTE appears to have good scalability within the framework proposed,and it also cuts down the processing time.

Set pair three-way overlapping community discovery algorithm for weighted social internet of things

There are many problems in Social Internet of Things(IoTs),such as complex topology information,different degree of association between nodes and overlapping communities.The idea of set pair information grain computing and clustering is introduced to solve the above problems so as to accurately describe the similarity between nodes and fully explore the multi-community structure.A Set Pair Three-Way Overlapping Community Discovery Algorithm for Weighted Social Internet of Things(WSIoT-SPTOCD)is proposed.In the local network structure,which fully considers the topological information between nodes,the set pair connection degree is used to analyze the identity,difference and reverse of neighbor nodes.The similarity degree of different neighbor nodes is defined from network edge weight and node degree,and the similarity measurement method of set pair between nodes based on the local information structure is proposed.According to the number of nodes'neighbors and the connection degree of adjacent edges,the clustering intensity of nodes is defined,and an improved algorithm for initial value selection of k-means is proposed.The nodes are allocated according to the set pair similarity between nodes and different communities.Three-way community structures composed of a positive domain,boundary domain and negative domain are generated iteratively.Next,the overlapping node set is generated according to the calculation results of community node membership.Finally,experiments are carried out on artificial networks and real networks.The results show that WSIoT-SPTOCD performs well in terms of standardized mutual information,overlapping community modularity and F1.

右半结肠癌根治术中全腹腔镜下Overlap吻合的短期疗效及并发症分析

目的:通过对比全腹腔镜下顺蠕动侧侧吻合(Overlap吻合)与腹腔外吻合相关临床资料及短期疗效,探究腹腔内吻合在右半结肠癌根治术中的临床疗效及价值。方法:回顾性选择2021年01月至2023年12月我院胃肠与疝外科收治的腹腔镜右半结肠癌根治术患者临床资料,共计92例纳入临床研究。其中采用腹腔内Overlap吻合的患者为ICA组;采用腹腔外端侧吻合为ECA组。收集并分析两组患者临床资料,讨论全腹腔镜下Overlap吻合安全性及短期临床疗效差异。结果:纳入患者一般资料差异无统计学意义(P值>0.05)。手术资料方面,ICA组手术时间[(185.83±27.55)min;P=0.026]与吻合时间[(33.86±4.05)min;P<0.001]均显著长于ECA组,切口长度方面[(4.86±0.84)cm;P<0.001]ICA组显著短于ECA组。而术中出血、清扫淋巴结总数两组差异无统计学意义。术后康复方面,ICA组首次排气时间[(2.55±0.55)天;P=0.001]、首次进流质时间[(3.38±0.62)天;P<0.001]、下床时间[(2.71±0.55)天;P=0.006]、术后住院时间[(7.67±1.26)天;P=0.019]均优于ECA组,且ICA组术后引流量[(277.74±147.68)mL;P=0.017]显著少于ECA组。在术后第3天,ICA组疼痛VAS评分(3.19±0.77;P=0.04)低于ECA组。术后炎症指标方面,两组术后C反应蛋白、中性粒细胞-淋巴细胞比值(NLR)均无统计学差异(P值>0.05)。在手术后并发症方面,总并发症发生率、吻合口瘘、腹腔感染、腹腔出血、吻合口出血、切口感染、肺部感染、术后肠梗阻、术后胃瘫两组并无统计学差异(P值>0.05)。结论:全腹腔镜下Overlap吻合安全可行,具有术后肠道功能恢复更快、创伤更小等优势,手术疗效与传统腔镜辅助手术效果相当,且不会增加短期并发症发生率。

Dual-wavelength pumped latticed Fermi-Pasta-Ulam recurrences in nonlinear Schrödinger equation

We show that the nonlinear stage of the dual-wavelength pumped modulation instability(MI)in nonlinear Schrödinger equation(NLSE)can be effectively analyzed by mode truncation methods.The resulting complicated heteroclinic structure of instability unveils all possible dynamic trajectories of nonlinear waves.Significantly,the latticed-Fermi-Pasta-Ulam recurrences on the modulated-wave background in NLSE are also investigated and their dynamic trajectories run along the Hamiltonian contours of the heteroclinic structure.It is demonstrated that there has much richer dynamic behavior,in contrast to the nonlinear waves reported before.This novel nonlinear wave promises to inject new vitality into the study of MI.

Vein visualization enhancement by dual-wavelength phase-locked denoising technology

Visual near-infrared imaging equipment has broad applications in various fields such as venipuncture,facial injections,and safety verification due to its noncontact,compact,and portable design.Currently,most studies utilize near-infrared single-wavelength for image acquisition of veins.However,many substances in the skin,including water,protein,and melanin can create significant background noise,which hinders accurate detection.In this paper,we developed a dual-wavelength imaging system with phase-locked denoising technology to acquire vein image.The signals in the effective region are compared by using the absorption valley and peak of hemoglobin at 700nm and 940nm,respectively.The phase-locked denoising algorithm is applied to decrease the noise and interference of complex surroundings from the images.The imaging results of the vein are successfully extracted in complex noise environment.It is demonstrated that the denoising effect on hand veins imaging can be improved with 57.3%by using our dual-wavelength phase-locked denoising technology.Consequently,this work proposes a novel approach for venous imaging with dual-wavelengths and phase-locked denoising algorithm to extract venous imaging results in complex noisy environment better.

Autoimmune hepatitis-primary biliary cholangitis overlap syndrome complicated by various autoimmune diseases:A case report

BACKGROUND Autoimmune hepatitis(AIH)and primary biliary cholangitis(PBC)are two common clinical autoimmune liver diseases,and some patients have both diseases;this feature is called AIH-PBC overlap syndrome.Autoimmune thyroid disease(AITD)is the most frequently overlapping extrahepatic autoimmune disease.Immunoglobulin(IgG)4-related disease is an autoimmune disease recognized in recent years,characterized by elevated serum IgG4 levels and infiltration of IgG4-positive plasma cells in tissues.CASE SUMMARY A 68-year-old female patient was admitted with a history of right upper quadrant pain,anorexia,and jaundice on physical examination.Laboratory examination revealed elevated liver enzymes,multiple positive autoantibodies associated with liver and thyroid disease,and imaging and biopsy suggestive of pancreatitis,hepatitis,and PBC.A diagnosis was made of a rare and complex overlap syndrome of AIH,PBC,AITD,and IgG4-related disease.Laboratory features improved on treatment with ursodeoxycholic acid,methylprednisolone,and azathioprine.CONCLUSION This case highlights the importance of screening patients with autoimmune diseases for related conditions.

Novel method for extraction of ship target with overlaps in SAR image via EM algorithm

The quality of synthetic aperture radar(SAR)image degrades in the case of multiple imaging projection planes(IPPs)and multiple overlapping ship targets,and then the performance of target classification and recognition can be influenced.For addressing this issue,a method for extracting ship targets with overlaps via the expectation maximization(EM)algorithm is pro-posed.First,the scatterers of ship targets are obtained via the target detection technique.Then,the EM algorithm is applied to extract the scatterers of a single ship target with a single IPP.Afterwards,a novel image amplitude estimation approach is pro-posed,with which the radar image of a single target with a sin-gle IPP can be generated.The proposed method can accom-plish IPP selection and targets separation in the image domain,which can improve the image quality and reserve the target information most possibly.Results of simulated and real mea-sured data demonstrate the effectiveness of the proposed method.

Predictors of survival in autoimmune liver disease overlap syndromes

BACKGROUND Survival in patients with autoimmune liver disease overlap syndromes(AILDOS)compared to those with single autoimmune liver disease is unclear.AIM To investigate the survival of patients with AILDOS and assess the accuracy of non-invasive serum models for predicting liver-related death.METHODS Patients with AILDOS were defined as either autoimmune hepatitis and primary biliary cholangitis overlap(AIH-PBC)or autoimmune hepatitis and primary sclerosing cholangitis overlap(AIH-PSC)and were identified from three tertiary centres for this cohort study.Liver-related death or transplantation(liver-related mortality)was determined using a population-based data linkage system.Prognostic scores for liver-related death were compared for accuracy[including liver outcome score(LOS),Hepascore,Mayo Score,model for end-stage liver disease(MELD)score and MELD incorporated with serum sodium(MELD-Na)score].RESULTS Twenty-two AILDOS patients were followed for a median of 3.1 years(range,0.35-7.7).Fourteen were female,the median age was 46.7 years(range,17.8 to 82.1)and median Hepascore was 1(range,0.07-1).At five years post enrolment,57%of patients remained free from liver-related mortality(74%AIH-PBC,27%AIH-PSC).There was no significant difference in survival between AIH-PBC and AIH-PSC.LOS was a significant predictor of liver-related mortality(P<0.05)in patients with AIH-PBC(n=14)but not AIH-PSC(n=8).A LOS cut-point of 6 discriminated liver-related mortality in AIH-PBC patients(P=0.012,log-rank test,100%sensitivity,77.8%specificity)(Harrell's C-statistic 0.867).The MELD score,MELD-Na score and Mayo Score were not predictive of liver-related mortality in any group.CONCLUSION Survival in the rare,AILDOS is unclear.The current study supports the LOS as a predictor of liver-related mortality in AIH-PBC patients.Further trials investigating predictors of survival in AILDOS are required.

Overlap吻合术式在腹腔镜结直肠手术重建中的临床研究

目的研究腹腔镜结直肠手术重建中运用侧侧吻合(Overlap)术式的临床价值。方法选择2022年1月至2023年2月期间龙游县人民医院收治的102例结直肠癌患者为研究对象,均行腹腔镜结直肠癌根治术,以吻合术式不同将其分为两组,其中行功能性端端吻合为对照组(n=51),采用Overlap吻合术式则为观察组(n=51),比较两组患者的围术期指标、炎症指标以及术后并发症发生情况,术后随访12个月,评价两组患者生活质量。结果观察组患者的术后住院、进食、手术以及排气时间均短于对照组,差异均有统计学意义(t分别=5.26、3.49、3.43、3.55,P均<0.05);观察组术后3 d的C反应蛋白(CRP)、白细胞介素-6(IL-6)以及肿瘤坏死因子-α(TNF-α)水平均低于对照组,差异均有统计学意义(t分别=13.14、15.79、12.49,P均<0.05);观察组患者的并发症发生率明显低于对照组,差异有统计学意义(χ^(2)=15.86,P<0.05);两组3、6、9、12个月的生活质量评分比较,差异均无统计学意义(t分别=0.19、0.50、0.60、0.62,P均>0.05)。结论在腹腔镜结直肠癌根治术中,通过采用Overlap吻合术式,不仅可以缩短手术时间,恢复胃肠道功能,还可以减少术后并发症,并且对患者生活质量无明显影响,可以作为有效且安全的一种吻合方式。

Pseudo-Semi-Overlap Functions-Based Fuzzy Rough Sets Applied to Image Edge Extraction

As an extension of overlap functions, pseudo-semi-overlap functions are a crucial class of aggregation functions. Therefore, (I, PSO)-fuzzy rough sets are introduced, utilizing pseudo-semi-overlap functions, and further extended for applications in image edge extraction. Firstly, a new clustering function, the pseudo-semi-overlap function, is introduced by eliminating the symmetry and right continuity present in the overlap function. The relaxed nature of this function enhances its applicability in image edge extraction. Secondly, the definitions of (I, PSO)-fuzzy rough sets are provided, using (I, PSO)-fuzzy rough sets, a pair of new fuzzy mathematical morphological operators (IPSOFMM operators) is proposed. Finally, by combining the fuzzy C-means algorithm and IPSOFMM operators, a novel image edge extraction algorithm (FCM-IPSO algorithm) is proposed and implemented. Compared to existing algorithms, the FCM-IPSO algorithm exhibits more image edges and a 73.81% decrease in the noise introduction rate. The outstanding performance of (I, PSO)-fuzzy rough sets in image edge extraction demonstrates their practical application value.

Analysis of bulging process of aluminum alloy by overlapping sheet metal and its formability

The influences of strength coefficient K, work hardening exponent n and thickness t of the overlapping sheet on bulging process are analyzed based on hardening material model. Also, bulging experiments are carried out by taking the aluminum alloy LF21 as formed sheet metal, and selecting overlapping sheet with different thicknesses and material properties, by which accuracy of the above analysis result is verified in the aspects of geometric shape, thickness distribution and limit bulging height. The results show that higher strength coefficient K, larger work hardening exponent n and proper thickness of the overlapping sheet are helpful to improve the formability and forming uniformity of formed sheet metal.

Feature study for improving Chinese overlapping ambiguity resolution based on SVM

In order to improve Chinese overlapping ambiguity resolution based on a support vector machine, statistical features are studied for representing the feature vectors. First, four statistical parameters-mutual information, accessor variety, two-character word frequency and single-character word frequency are used to describe the feature vectors respectively. Then other parameters are tried to add as complementary features to the parameters which obtain the best results for further improving the classification performance. Experimental results show that features represented by mutual information, single-character word frequency and accessor variety can obtain an optimum result of 94. 39%. Compared with a commonly used word probability model, the accuracy has been improved by 6. 62%. Such comparative results confirm that the classification performance can be improved by feature selection and representation.

Overlap吻合术对腹腔镜胃癌消化道重建和并发症及患者生活质量的影响

目的:研究完全腹腔镜胃癌根治术联合overlap吻合术对消化道重建、并发症及患者生活质量的影响。方法:选取2019年6月至2021年12月于蚌埠医学院第一附属医院接受诊治的110例胃癌患者为研究对象。根据不同手术方式分为对照组(传统腹腔镜胃癌根治术,n=60)与观察组(完全腹腔镜胃癌根治术联合overlap吻合术,n=50),比较2组手术疗效及并发症,并采用胃肠道生活质量表(Gastrointestinal Quality of Life,GIQLI)评估生活质量。结果:观察组手术全程用时、消化道重建用时、总失血量均少于对照组(均P<0.05);2组肿瘤大小、淋巴结清扫数比较差异均无统计学意义(均P>0.05)。观察组术后排气时间、流食进食时间、下地时间均少于对照组(均P<0.05);2组住院时间差异无统计学意义(P>0.05)。观察组术后并发症总发生率低于对照组(P<0.05)。随访6个月,2组GIQLI各维度得分及总分均高于出院当天(均P<0.05),观察组GIQLI各维度得分及总分均高于对照组(均P<0.05)。结论:完全腹腔镜胃癌根治术联合overlap吻合术能有效重建消化道,减少并发症,改善生活质量。

FEM SIMULATION OF RESIDUAL STRESSES INDUCED BY LASER SHOCK WITH OVERLAPPING LASER SPOTS

The finite element method is presented to attain the numerical simulation of the residual stresses field in the material treated by laser shock processing. The distribution of residual stresses generated by a single laser shock with square and round laser spot is predicted and validated by experimental results. With the Finite Element Method （FEM） model, effects of different overlapping rates and impact sequences on the distribution of residual stresses are simulated. The results indicate that： （1） Overlapping laser shock can increase the compressive residual stresses. However, it is not effective on the growth of plastically affected depth; （2） Overlapping rate should be optimized and selected carefully for the large area treatment. Appropriate overlapping rate is beneficial to obtain a homogeneous residual stress field; （3） The impact sequence has a great effect on the residual stress field. It can greatly attenuate the phenomenon of the “residual stress hole” to obtain a homogeneous residual stress field.

Detecting overlapping communities in networks via dominant label propagation

Community detection is an important methodology for understanding the intrinsic structure and function of a realworld network. In this paper, we propose an effective and efficient algorithm, called Dominant Label Propagation Algorithm（Abbreviated as DLPA）, to detect communities in complex networks. The algorithm simulates a special voting process to detect overlapping and non-overlapping community structure in complex networks simultaneously. Our algorithm is very efficient, since its computational complexity is almost linear to the number of edges in the network. Experimental results on both real-world and synthetic networks show that our algorithm also possesses high accuracies on detecting community structure in networks.