Application Of Cluster Analysis Research Articles

Application of bioinformatics approach to identify indications for PFKFB3-mediated glycolysis inhibition as potential anticancer treatment.

e23158 Background: Glycolysis is one of the mechanisms which enables cancer cells to adapt to intermittent oxygen deprivation and obtain the best available metabolic strategy in the lack of resources. Therefore, inhibition of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3) enzyme, one of the glycolysis pathway regulators, may result in decreased tumor metabolism, as well as suppressed cell growth. Additionally it has been shown that PFKFB3 is involved in angiogenesis regulation, which contributes to tumor growth, and in immune cells activation, which mediates anti-tumor immune response. Methods: We performed the analysis of available data on the role of PFKFB3 gene expression in various cancer types, i.e. patients’ stratification to identify tumors in which PFKFB3 inhibition improved survival. We exploited TCGA expression data and applied cluster analysis and Cox-regression analysis. The objective was to detect the relation between the increased level of PFKFB3 gene expression and patients’ survival. We also compared the clusters we identified with TCGA metadata to define whether any of them fall down into well-established tumor subtypes. Results: As a result we selected four clusters among solid tumor types, in which increased expression of the target was related to significant decrease in overall survival rate. These include breast cancer, renal cell carcinoma, cervical carcinoma, and leiomyosarcoma. We managed to cross-validate the obtained results on independent datasets. The results show potential indications for PFKFB3 inhibitors. Using our proprietary molecular modelling tool, we designed a series of novel small molecule PFKFB3 inhibitors to target the fructose binding pocket rather than occupying the ATP-pocket which leads to the highly selective inhibition and strong reduction of potential off-target binding. We proved target coverage by performing in vitro biochemical assays. Conclusions: Our current data provide strong rationale for further preclinical and clinical development of PFKFB3 inhibitors as novel anticancer treatment with the potential to overcome resistance to chemo- or radiotherapy.

All circular but different: Variation in patterns of Ukraine‐to‐Poland migration

AbstractIn many of the “newest” immigration countries of Central and Eastern Europe, temporary migration prevails and rates of migrants' settlement are low. This article examines variations in temporary migration patterns and what distinguishes migrants who choose “more permanent” time–space strategies in such temporary migration regimes. Taking Ukrainian migration to Poland as a case study, and applying cluster analysis to survey data from 2010, we propose an empirical typology of migrants based on parameters of their overall mobility history. The majority consists of circular migrants who can be described as either regular or intermittent circulants. Those who represent more permanent mobility patterns can be termed circular transmigrants and long‐term migrants. The latter are more likely than circulants to work outside agriculture, construction, and domestic services—seen as migrant sectors in Poland—and are less involved in family duties in Ukraine. Further, women are more likely than men to be involved in temporary migration for sustained time. The article contributes to the migration literature by proposing a typology of temporary migrants based on detailed parameters of their mobility and by examining how selected characteristics of migrants correlate with their mobility patterns in a temporary migration regime such as posed by Poland.

군집 분석을 활용한 아파트 실거래가격지수 연구 - 서울시 사례를 중심으로 -

This paper suggests a new method for calculating the transaction price index, which applies cluster analysis to ameliorate interregional heterogeneity and instability caused by missing data of transaction prices. In order to address the issue concerning missing values, absent data were estimated by using either the linear regression model, which utilized clustering information, or the linear interpolation model, depending on the continuity patterns of missing values. And in order to address the issue of interregional heterogeneity, the clustering analysis-applied apartment transaction price index for administrative district Gu was drawn from information on transaction prices of administrative district Dong. As a result of analyzing data of apartment transaction prices in Seoul from July 2011 to June 2016, it was found that the clustering analysis-based apartment transaction price index is more suitable than the existing index in terms of data applicability and the alleviation of regional inconsistencies.

The dynamic capabilities perspective of strategic management: a co-citation analysis

Dynamic capabilities currently emerge as a vibrant field of study within the theoretical framework based on resource and strategic management. To this end, and as a complex field of study, we set out to conceptually map this approach. Hence, we carried out a bibliometric study with recourse to co-citations. For the multivariate analysis, we applied cluster analysis and factor analysis. Through the former, we conclude that dynamic capacities concentrate on five approaches: Digital Capabilities, Knowledge Capabilities, Absorptive Capabilities, Strategic Capabilities and Resources. As regards factor analysis, this returns five factors with two of them concentrated into the same approach: Resources and Capabilities. We would also state that the Strategic Capabilities approach spans across the remaining three factors and does not constitute a single factor.

Journal segmentation and competitive position based on revenue management research publications

This work is focused on studying the editorial profile of journals which have published articles on Revenue Management in Tourism. To do so, these were put into groups according to how they addressed three dimensions: the research methodology used (R), their topic (T), and the strategy of Revenue Management dealt with (S). Applying cluster analysis, 67 top journals were grouped together after considering a total of 293 references published in a 25-year period (1989–2013). The results show comparatively the great variety of journals and profiles that have disseminated works on Revenue Management in Tourism. The following has been identified (1) journals with singular behaviors which broadly respond to the variety of methodologies, topics, and strategies of Revenue Management, (2) groups of journals which are centered on specific aspects, and (3) others which still deal marginally with the discipline. It is especially useful for researchers, enabling them to, based on critical aims, define a publication strategy, and for editors, offering them the possibility of ascertaining the relative position of their journal with respect to others.

Electrophoretic profiles of lipopolysaccharides from Rhizobium strains nodulating Pisum sativum do not reflect phylogenetic relationships between these strains

Rhizobia that nodulate peas comprise a heterogeneous group of bacteria. The aim of this study was to investigate the relationship between phylogeny and electrophoretic and hydroxy fatty acid lipopolysaccharide (LPS) profiles of pea microsymbionts. Based on amplified fragment length polymorphism (AFLP) fingerprinting data, the pea microsymbionts were grouped into two clusters distinguished at 58% similarity level. Based on the concatenated 16S rRNA, recA, and atpD housekeeping gene data, the microsymbionts appeared to be most closely related to Rhizobium leguminosarum biovars viciae and trifolii. Applying cluster analysis to their LPS electrophoretic profiles, the strains were assigned to two major groups with different banding patterns. All hydroxy fatty acids common to R. leguminosarum and R. etli were detected in each examined strain. Differences in the proportions of 3- to ω-1 hydroxy fatty acids allowed us to distinguish two groups of strains. This classification did not overlap with one based on LPS electrophoretic profiles. No clear correlation was apparent between the genetic traits and LPS profiles of the pea nodule isolates.

Hierarchical tendencies and functional patterns among Mainland China’s megaregions

This paper presents an empirical analysis of hierarchical tendencies and functional patterns in the development of Mainland China’s space-economy by operationalizing the concept of “megaregions.” Drawing on the burgeoning literature on megaregions, we first argue that under conditions of economic globalization the megaregion concept does indeed present an effective tool to study the spatial agglomeration of the key components of China’s economic development. Second, we analyze the development status and the key functional characteristics of 16 prospective Chinese megaregions by constructing an index system consisting of 5 functions and 36 indicators. Third, we calculate an entropy index to rank megaregions according to their overall development status and reveal functional differences by applying cluster analysis. We find that the Yangtze River Delta, Beijing–Tianjin–Hebei Metropolitan Area, and the Pearl River Delta stand out, identify different varieties of megaregions according to their dominant functional characteristics, and explore the main policy dimensions of the persistent west–east divides observed. The paper is concluded with a discussion of potential avenues for future research.

Evaluation of Innovative Undertakings with the European Union Funds. Polish Voivodships Scope

The main purpose of the paper is the assessment of the European Union funds engagement in innovative undertakings in Polish voivodships. Firstly, it was made the considerations about innovations as an essential component of an integrated approach in terms of regions’ competiveness improvement. Furthermore, it was examined the differentiation in the participation of the EU funds in innovative undertakings between Polish voivodships. In this respect was applied cluster analysis, on base which was isolated space groups, which allow to comparison of the European Union funds involvement between voivodships of Poland. The research were based on data from Central Statistical Office of Poland — Local Data Bank — concerning particularly the Programme Innovative Economy. The scope of examinations contains period 2011–2015. The effects of examinations affects the ability to identify voivodships similar in scope of the accepted variables. This identification may contribute to create of comparative base actions taken to improve innovations, which could lead to an increase in the competitiveness of regions.

Differentiating peri-urban areas: A transdisciplinary approach towards a typology

Peri-urban areas have no clear boundaries, both in geographic and conceptual terms. This paper presents a transdisciplinary approach for the identification of typologies of peri-urban areas and applies it to the Lisbon Metropolitan Area (LMA), Portugal. It is based on the assumptions that more than one type of peri-urban region around an urban core can exist, and that a transdisciplinary approach, linking the physical, economic, social and personal aspects, is needed to capture the intrinsic variability and the complexity of the peri-urban character. The approach is based on four sequential steps: (i) identifying the important peri-urban dimensions to be considered, based on expert-knowledge and stakeholder perspectives; (ii) defining a set of indicators for each dimension; (iii) summarizing redundant information for each dimension; and (iv) applying cluster analysis to identify typologies of peri-urban. This approach was applied to the 211 parishes comprised in the LMA. Seven types of parishes were identified, of which two can be considered urban and five peri-urban, although with quite distinct features. This approach has the potential to be applied to other metropolitan regions, and the resulting peri-urban (and urban) typologies can contribute to a better understanding of the peri-urban character, and to a more targeted implementation of planning and management strategies taking into consideration the diversity and specificities of each peri-urban type.

The impact of shop floor culture and subculture on lean production practices

PurposeThe purpose of this paper to examine the impact of shop floor (SF) culture (organizational culture (OC) perceived by workers) and SF subcultures assessed by the competing values framework (CVF) on the perceived use of lean production (LP) practices.Design/methodology/approachThe authors analyse questionnaires completed by workers at the single case company undergoing a commonplace lean transformation. The survey items cover both LP items and CVF statements. The propositions are analysed applying cluster analysis and regression.FindingsAt the case company, the multidimensionality of SF culture only partially exists, and the perceived use of LP practices shows little connection to OC. The considerable differences between SF culture and SF subcultures on the one hand and among SF subcultures on the other hand indicate the existence of a special multidimensional SF culture. Altogether, SF culture’s impact on LP is weak.Practical implicationsManagers should rethink the usual lean implementation pathways and understand how values pervade SF culture and how culture types impact the perceived use of LP practices at the SF. Managers could face a trade-off: smoother lean transition by engaging in SF subculture-specific transitions and reinforcing it or by developing a homogenous lean SF culture.Originality/valueTo the best of the authors’ knowledge, this is the first empirical attempt to understand the impact of SF culture on the perceived use of LP practices by adopting a validated OC measurement tool. Furthermore, the study provides insight into workers’ subcultures.

Regional mapping of vegetation structure for biodiversity monitoring using airborne lidar data

Vegetation structure is identified as an important biodiversity indicator providing the physical environment that generates, supports, and maintains forest biodiversity. Airborne lidar systems (light detection and ranging) have the capacity to accurately measure three-dimensional vegetation structure, and have been widely used in wildlife habitat mapping and species distribution modeling. Large–area structural inventories using lidar-derived variables that characterize generic habitat structure have rarely been done, yet would be helpful for guiding biodiversity monitoring and conservation assessments of species at regional levels. This study provides a novel approach for processing regional-scale lidar data into categorical classes representing natural groupings of habitat structure. We applied cluster analysis on six lidar-derived habitat-related variables to classify vegetation structure into eight classes for the forested areas of ten natural subregions in boreal and foothill forests in Alberta, Canada. Structure classes were compared across different natural subregions and under anthropogenic/non-anthropogenic disturbance regimes. We found that the Lower Foothills Natural Subregions had the most complex vegetation structure, and wildfire was the most prevalent disturbance agent for all classes except for the rarest class (i.e. stands with high standard deviations of height and low canopy cover) which was more heavily altered by timber harvesting. This data product provides continuous, regional mapping of vegetation structure directly measured from lidar, with a spatial resolution (30m) relatively finer than what was provided by polygon-based forest inventories. This vegetation structure classification and its associated spatial distribution address the fundamental issue of habitat structure in biodiversity monitoring. It can serve as a base layer used together with species and land cover data for forest resources planning, species distribution and animal movement modeling, as well as prioritization of conservation efforts on critical habitat structures.

Evaluation of peer effects on eating behaviors: a cluster analysis approach

ABSTRACTObjectives: In this study, we aimed to determine the effects of socio-demographic characteristics and the peer groups on the eating attitude and body mass index (BMI) of students at a medical school in Turkey.Methods: This cross-sectional study was conducted with the participation of the students of Gulhane Military Medical Academy (GMMA). Ethical permissions of the study were obtained from the GMMA Ethics Committee. The target population of the study consisted of 703 students, 533 of whom (75.8%) agreed to participate in the study. The Eating Attitudes Test (EAT) was administered to the participants and their BMI was noted. The EAT consists of 10 questions that measure the socio-demographic characteristics of the participants and 40 questions that evaluate eating habits. In order to determine the peer groups of the students, each student was asked to provide the numbers of their three closest friends. Three peer groups were generated for each grade by applying cluster analysis and as a result 18 ...

Comprehensive Transportation Logistics Network Level Layout Based on Principal Component Factor and Cluster Analysis

Comprehensive Transportation Logistics Network (CTLN) acts as a crucial prop and fundamental carrier for regional economic and social development. Firstly, an index system for evaluating the development of regional Comprehensive Transportation Logistics (CTL) nodes is established; then regional CTLN nodes are ranked according to their importance by the method of Principal Component Analysis(PCA), and main factors affecting the development of regional CTL nodes are analyzed by applying factor analysis, and regional CTL nodes are classified according to their feature similarities by applying cluster analysis; and then level structure of constructing regional CTLN is proposed. Finally, combined with geographic locations of different nodes, level layout model of CTLN of the whole region is obtained. Taking Henan province this region as an instance, level layout model of hub-and-spoke CTLN taking Zhengzhou at its core is proposed after analysis, providing a reference basis for constructing CTLN in whole province scientifically and reasonably.

Proteomic Clustering Analysis of SH2 Domain Datasets.

Proteomic clustering analysis provides a means of identifying relationships and visualizing those relationships in an extremely complex field of study with many interacting parts. With recent high-throughput studies of Src Homology 2 (SH2) domains, many and varied datasets are being amassed. A strategy for analyzing patterns between these large datasets is required to transform the information into knowledge. The methods for creating neighbor-joining phylogenetic trees, pairs scatter plots, and two-dimensional hierarchical clustering heatmaps are just a few of the diverse methods available to a proteomic researcher. This chapter examines selecting objects to be analyzed, selecting comparison functions to apply to those objects, and pseudo-code for processing data and preparing it for various types of analyses. Here I apply clustering analysis to previous collections of SH2 domains datasets to bring insight into new binding or specificity patterns between the different SH2 domains.

Defining Philippine Climate Zones Using Surface and High-Resolution Satellite Data

Philippine climate zones traditionally were classified from a rain-gauge network, using the Modified Coronas Classification (MCC). MCC uses average monthly rainfall totals to define four climate zones: Types I-IV. Types I and III have wet and dry seasons, whereas Types II and IV have wet seasons but no dry seasons.The present study redefines Philippine climate zones by applying cluster analysis to the average monthly rainfall amounts from surface-based rain-gauge observations, and dense, high-resolution satellite data from the Tropical Rainfall Monitoring Mission (TRMM). To determine the optimal number of climate type clusters, both single-linkage hierarchical and K-means cluster analysis algorithms were used, together with known characteristics of Philippine rainfall distributions and attributes.Employing single linkage hierarchical and K-means methods in tandem identified six different Philippine climate types, which is two climate types more than the currently accepted MCC climate classification. Due to the far greater number of TRMM observations compared with the rain gauge network, the study provides more clearly defined cluster characteristics including the spatial and temporal variability of climate divisions. This study uses known meteorological factors contributing to the identification of six distinct climate types. This paper is intended to assist agricultural stakeholders with planning and decision-making.

Spatial Variation of Soil Respiration in a Cropland under Winter Wheat and Summer Maize Rotation in the North China Plain.

Spatial variation of soil respiration (Rs) in cropland ecosystems must be assessed to evaluate the global terrestrial carbon budget. This study aims to explore the spatial characteristics and controlling factors of Rs in a cropland under winter wheat and summer maize rotation in the North China Plain. We collected Rs data from 23 sample plots in the cropland. At the late jointing stage, the daily mean Rs of summer maize (4.74 μmol CO2 m-2 s-1) was significantly higher than that of winter wheat (3.77μmol CO2 m-2 s-1). However, the spatial variation of Rs in summer maize (coefficient of variation, CV = 12.2%) was lower than that in winter wheat (CV = 18.5%). A similar trend in CV was also observed for environmental factors but not for biotic factors, such as leaf area index, aboveground biomass, and canopy chlorophyll content. Pearson’s correlation analyses based on the sampling data revealed that the spatial variation of Rs was poorly explained by the spatial variations of biotic factors, environmental factors, or soil properties alone for winter wheat and summer maize. The similarly non-significant relationship was observed between Rs and the enhanced vegetation index (EVI), which was used as surrogate for plant photosynthesis. EVI was better correlated with field-measured leaf area index than the normalized difference vegetation index and red edge chlorophyll index. All the data from the 23 sample plots were categorized into three clusters based on the cluster analysis of soil carbon/nitrogen and soil organic carbon content. An apparent improvement was observed in the relationship between Rs and EVI in each cluster for both winter wheat and summer maize. The spatial variation of Rs in the cropland under winter wheat and summer maize rotation could be attributed to the differences in spatial variations of soil properties and biotic factors. The results indicate that applying cluster analysis to minimize differences in soil properties among different clusters can improve the role of remote sensing data as a proxy of plant photosynthesis in semi-empirical Rs models and benefit the acquisition of Rs in cropland ecosystems at large scales.

Repertoires of national boundaries in France and Germany—within‐country cleavages and their political consequences

AbstractThis article analyses how members of the majority population in France and Germany define membership in the nation and how they relate to the various civic, cultural, or ethnic visions of national belonging available in the cultural repertoires of historical models, institutional arrangements, and elite discourses. To scrutinize within‐country differences in the configurations of the symbolic boundaries of national belonging, this article applies cluster analysis techniques for each country separately using data from the International Social Survey Program (ISSP). Overall, the results suggest that people choose and arrange different criteria from cultural repertoires, resulting in various configurations of national boundaries. Furthermore, the number and types of symbolic boundaries used are decisive for explaining restrictive and hostile attitudes towards immigrants. Contrary to the civic and ethnic historical models, the national boundary configurations display very similar patterns across the two countries, especially attesting to the considerable process of liberalization of citizenship regulations in Germany.

Profiling public transport users through perceptions about public transport providers and satisfaction with the public transport service

Priority has been given to increasing public transport use in the mobility programmes of developed countries as part of a global strategy to manage traffic congestion and air pollution in urban areas. Understanding citizens’ travelling behaviour, their perceptions and satisfaction after experiencing public transport services is crucial to the delineation of efficient future mobility programmes. In this paper we apply cluster analysis to segment public transport users in a Portuguese urban area according to their perceptions of public transport operators and satisfaction with the public transport service. The outcomes reveal four segments of public transport users: one positive, one indifferent and the other two negative. Managerial implications of the findings are discussed.

Importance of Various Service Types in Hotels - Empirical Analysis

Abstract Hotels offer different types of services which have different impacts on the users’ satisfaction and have an influence in various extents on decision making, when it comes to the selection of hotels. As a part of research, empirical analysis based on the importance of different services which hotels provide, was conducted. The idea of research is to determine the importance of different types of services for users. The survey was conducted on a sample of 850 respondents in Serbia. The study used AHP methodology which is used in the decisionmaking process analysis and is suitable for studies defining the rank of relevance of individual elements. The obtained results presented in the study provide information such as, what services offered by hotels have the greatest importance for users. Based on the obtained results in empirical research, and by applying cluster analysis, two different segments of hotel guests are identified based on the preferred services. Segments are statistically different and can represent various targets in the hotel business policy.

Detecting Fraudulent Interviewers by Improved Clustering Methods – The Case of Falsifications of Answers to Parts of a Questionnaire

Abstract Falsified interviews represent a serious threat to empirical research based on survey data. The identification of such cases is important to ensure data quality. Applying cluster analysis to a set of indicators helps to identify suspicious interviewers when a substantial share of all of their interviews are complete falsifications, as shown by previous research. This analysis is extended to the case when only a share of questions within all interviews provided by an interviewer is fabricated. The assessment is based on synthetic datasets with a priori set properties. These are constructed from a unique experimental dataset containing both real and fabricated data for each respondent. Such a bootstrap approach makes it possible to evaluate the robustness of the method when the share of fabricated answers per interview decreases. The results indicate a substantial loss of discriminatory power in the standard cluster analysis if the share of fabricated answers within an interview becomes small. Using a novel cluster method which allows imposing constraints on cluster sizes, performance can be improved, in particular when only few falsifiers are present. This new approach will help to increase the robustness of survey data by detecting potential falsifiers more reliably.