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Whereas in one-mode data, individuals or groups are connected directly with one another through interactions or relations, in two-mode data, individuals are indirectly connected with one another through affiliations (events, organizations, associations, alliances, and so on). Affiliation data are often used as a proxy for detecting ties among social actors when direct evidence of ties is difficult to obtain. For example, it is generally easier to know that two people belong to the same club or work in the same department than to know that they have lunch together every Thursday. But affiliation data can also be used to see aspects of social structures not visible in one-mode networks. Duality is a kind of structural relation that shows how levels of social structure intersect with one another. We discuss the classic approach to duality as well as two generalizations that extend the duality approach in hierarchical, temporal, and spatial directions.
The components or functions derived from an eigenanalysis are linear combinations of the original variables. Principal components analysis (PCA) is a very common method that uses these components to examine patterns among the objects, often in a plot termed an ordination, and identify which variables are driving those patterns. Correspondence analysis (CA) is a related method used when the variables represent counts or abundances. Redundancy analysis and canonical CA are constrained versions of PCA and CA, respectively, where the components are derived after taking into account the relationships with additional explanatory variables. Finally, we introduce linear discriminant function analysis as a way of identifying and predicting membership of objects to predefined groups.
The information included on food packages has a crucial role in influencing consumer product associations and purchase decisions. In particular, visual and textual cues on processed and ultra-processed products can convey health-related associations that influence consumer healthiness perception and purchase decisions. In this context, the present work aimed to explore the use of health-related cues on the packages of processed and ultra-processed products sold in Uruguay to provide insights for policy making. A total of 3813 products from thirty-four different food categories found in four of the most important supermarket chains in Uruguay were surveyed. The textual and visual information included on the packages as well as the nutritional composition of the products were analysed. Results showed that 67 % of the products included at least one health-related cue. Pictures of culinary ingredients, natural and minimally processed foods were the most frequent health-related cue, followed by references to naturalness and claims related to critical nutrients. The prevalence of health-related cues largely differed across product categories, ranging from 100 to 17 %. The relationship between the presence of health-related cues on the packages and the excessive content of nutrients associated with non-communicable diseases was assessed using a gradient boosting model, which showed limited predictive ability. This suggests that the inclusion of health-related cues on food packages was not strongly related to the nutritional composition of products and therefore cannot be regarded as a healthiness indicator. These results stress the need to develop stricter labelling regulations to protect consumers from misleading information.
This article examines the phenomenon of so-called North African-style pottery made in early third-century York. The pottery, which was produced in significant quantities in late Ebor ware, is strikingly different from vessels in circulation in Roman Britain and the north-west provinces – so much so that the late Vivien Swan argued that it was ‘made by Africans for the use of Africans’. The present study reassesses the evidence of ceramic genealogical influences, production waste, fabric supply, consumption patterns and contextual finds associations. The results shed new light on the manufacture and use of late Ebor ware by York's military community, qualifying claims made about the repertoire's links with novel culinary practices, cultural diversity and the unique historical circumstances of Severan York.
Disturbances and successional dynamics shape the composition of tree communities, but data remain scarce for tropical forests of West Africa. We assessed the imprint of past disturbances on the composition of evergreen forests in an Ivorian National Park. We hypothesized that (i) Pioneer indices (PI) based on the relative proportion of pioneer and non-pioneer trees relate to changing floristic composition due to successional dynamics, (ii) local community richness peaks at an intermediate value of PI under the Intermediate Disturbance Hypothesis (IDH) and (iii) early successional communities have higher beta diversity due to erratic founder effects. We performed a Correspondence Analysis of tree composition of 38 plots and examined how the main components of floristic variation related to environmental factors and PI. In addition, we tested the relationship between PI, local richness and beta diversity. The variation of PI better explained the main components of floristic variation than abiotic environmental variation, supporting a primary role of successional dynamics in shaping tree communities. We found a peak of richness at intermediate values of PI, supporting the IDH, with a mixture and earlier and later-successional species and more even abundances. The communities were very diverse and included many endemics and rare species. The results underline that the composition of early successional forests greatly varies depending on chance colonization events, while more similar old-growth communities are eventually observed after several decades. The findings should guide management practices for forest restoration, and for conservation of endangered species depending on their successional status.
This paper proposes a robust text classification and correspondence analysis approach to identification of similar languages. In particular, we propose to use the readily available information of clauses and word length distribution to model similar languages. The modeling and classification are based on the hypothesis that languages are self-adaptive complex systems and hence can be classified by dynamic features describing the system, especially in terms of distributional relations of constituents of a system. For similar languages whose grammatical differences are often subtle, classification based on dynamic system features should be more effective. To test this hypothesis, we considered both regional and genre varieties of Mandarin Chinese for classification. The data are extracted from two comparable balanced corpora to minimize possible confounding factors. The two corpora are the Sinica Corpus from Taiwan and the Lancaster Corpus of Mandarin Chinese from Mainland China, and the two genres are reportage and review. Our text classification and correspondence analysis results show that the linguistically felicitous two-level constituency model combining power functions between word and clauses effectively classifies the two varieties of Chinese for both genres. In addition, we found that genres do have compounding effect on classification of regional varieties. In particular, reportage in two varieties is more likely to be classified than review, corroborating the complex system view of language variations. That is, language variations and changes typically do not take place evenly across the board for the complete language system. This further enhances our hypothesis that dynamic complex system features, such as the power functions captured by the Menzerath–Altmann law, provide effective models in classifications of similar languages.
We propose a data-driven network-based approach to understand the interactions among technologies, products, and customers. Specifically, the approach enables both a qualitative understanding and a quantitative assessment of the impact of technological changes on customers’ co-consideration behaviors (decision of cross-shopping) and as a consequence the product competitions. The uniqueness of the proposed approach is its capability of predicting complex co-consideration relations of products as a network where both descriptive analyses (e.g., network statistics and joint correspondence analysis) and predictive models (e.g., multiple regressions quadratic assignment procedure) are employed. The integrated network analysis approach features three advantages: (1) It provides an effective visual representation of the underlying market structures; (2) It facilitates the evaluation of the correlation between customers’ consideration preferences and product attributes as well as customer demographics; (3) It enables the prediction of market competitions in response to potential technological changes. This paper demonstrates the proposed network-based approach in a vehicle design context. We investigate the impacts of the fuel economy-boosting technologies and the turbocharged engine technology on individual automakers as well as the entire auto industry. The case study provides vehicle engineers with insights into the change of market competitions brought by technological developments and thereby supports attribute decision-making in vehicle design.
B. Kooi and A. Tamminga present a correspondence analysis for extensions of G. Priest’s logic of paradox. Each unary or binary extension is characterizable by a special operator and analyzable via a sound and complete natural deduction system. The present paper develops a sound and complete proof searching technique for the binary extensions of the logic of paradox.
Populism is being increasingly studied by political and social scientists. This article pays particular attention to the way in which ‘people’ can be approached and appealed to by their leaders. In particular, by undertaking a content analysis of the two most read daily newspapers in Italy, and by relying on the technique of correspondence analysis, this article shows that to fully understand the phenomenon of populism, the way in which ‘the people’ are approached by their leaders cannot be left aside. In doing so, this article empirically analyses and discusses three dimension of populism and contributes to a more granular understanding of this phenomenon in established democracies.
The internal layout of early settlements can provide insight into social
organisation and the processes of Neolithic expansion into Europe. Analysis
of variables describing 71 sites revealed a spectrum extending between two
distinct settlement types that can be regionally and chronologically
situated. The very early ‘Anatolian village’ in the south-east exhibits
multi-level organisation, reflected in concentrated residence and temporal
stability; the younger (post 6000 BC) ‘Balkan village’ in the north-west
represents a new model with less centralised control of space and a less
permanent layout. Between these types is a transitional domain of more
heterogeneous, and ever-changing settlement layouts, which is characterised
as a ‘third space’ of hybridised traditions.
A total of 700 adult female goats from Sétif area (Algeria), were investigated for eight qualitative morphological traits and 17 body measurements. Sampling included three environmental areas: Northern, Central and Southern area. Coefficients of variation ranged from 10.9 percent to 34.7 percent, showing high heterogeneity. Canonical analyses showed that differences in body measurements between the three area-populations were large and significant in all traits (P < 0.001). The shortest Mahalanobis distance was found between North-Center populations (2.8), while that between Center (4.0) and (8.6) between North-South populations were the largest. Discriminant analysis showed that most goat-populations were classified into their environmental-area, North (73.0 percent), Center (66.8 percent) and South (79.3 percent) with a few misclassified individuals. Correspondence analysis indicated no large differences between the goat populations; they were more homogeneous for qualitative traits. This information will constitute the basis for further characterization and develop conservation strategies for Algerian goat populations
This article examines the role of a range of large settlements in late Iron Age and early Roman southern Britain (c. 100 BC–AD 70) conventionally described as oppida. After reviewing current perspectives on the function and chronology of British oppida, new insights are provided through the statistical analysis of assemblages of brooches and imported ceramics at a broad sample of sites. Analysis of material culture reveals distinct similarities and differences between several groups of sites, often transcending regional traditions and supposed tribal boundaries. This patterning is primarily explained by the emergence of new forms of political organization prior to Roman annexation, particularly the creation of the Southern and Eastern Kingdoms.
The composition, abundance, population structure and distribution patterns of the woody species having a girth at breast height of ≥ 10 cm were investigated in the tropical wet evergreen forests of the Kalakad-Mundanthurai Tiger Reserve in the southern Western Ghats, India. A 3 ha plot was established with an altitudinal range of 1170 to 1306 m. In the study plot 5624 individuals (mean density 1875 ha−1) covering 68 woody species belonging to 52 genera and 27 families were enumerated. The mean basal area was 47.01 m2 ha–1 and the Shannon and Simpson diversity indices were 4.89 and 0.95, respectively. Of these woody species nearly 51% are endemic to the Western Ghats. The four dominant species, Cullenia exarillata, Palaquium ellipticum, Aglaia bourdillonii and Myristica dactyloides, account for 34% of the trees and 67% of the basal area, and therefore constitute the main structure of the forest. Within this forest type, five species assemblages corresponding to altitudinal gradient were identified using correspondence analysis. Management of such mid elevation evergreen forests necessarily depends on knowledge of recognisable community types and their environmental variables. The present study provides essential background for formulating strategies for sustainable conservation of forest communities at the local level.
This paper presents preliminary research into the social and economic impact of early urban settlement in Britain, focusing on the case-study area of Late Iron Age to Roman Essex. Through fresh analysis of ceramic assemblages from Colchester and Heybridge, we describe hitherto unrecognised socio-cultural groupings and identities through subtle differences in the deposition of pottery in the generations before and after conquest. The concluding discussion concentrates on problems that we still have to address in describing the economic basis of early urban society in Britain.
The analysis of beta diversity (inter-habitat diversity) of very species-rich and incompletely sampled tropical arthropod communities requires the choice of appropriate statistical tools. The performance of the three commonly employed ordination methods, correspondence analysis (CA), detrended correspondence analysis (DCA), and non-metric multidimensional scaling (NMDS), was compared on a large empirical data set of geometrid moths sampled along an altitudinal gradient in an Andean montane rain forest. Despite the high species richness and incompleteness of the ensembles, all methods depicted the same, readily interpretable patterns. Both CA and NMDS showed an arch-like structure, which hints at an underlying coenocline, whereas this arch was computationally eliminated in DCA. For this particular data set, CA and NMDS both provided convincing results while the detrending algorithm of DCA did not improve the interpretability of the data. Of the large number of similarity indices available to be used in combination with NMDS, the binary Sørensen and the abundance-based Normalized Expected Species Shared (NESS) index were tested. Performance of the indices was measured by comparing stress, a measure of poorness-of-fit in NMDS. NMDS ordinations with lowest values of stress were achieved by the NESS index with the parameter m set to its maximum (mmax). In contrast, ordinations based on NESS values with the parameter m set to 1 (identical with Morisita's index), had consistently higher stress values and performed worse than ordinations using Sørensen's index. Hence, if high values of m can be achieved in similar data sets, the NESS index with mmax is recommended for ordination purposes and Morisita's index should be avoided.
The usage of alternative synonymous codons in the completely sequenced, extremely A+T-rich parasite Plasmodium falciparum was studied. Confirming previous studies obtained with less than 3% of the total genes recently described, we found that A- and U-ending triplets predominate but translational selection increases the frequency of a subset of codons in highly expressed genes. However, some new results come from the analysis of the complete sequence. First, there is more variation in GC3 than previously described; second, the effect of natural selection acting at the level of translation has been analysed with real expression data at 4 different stages and third, we found that highly expressed proteins increment the frequency of energetically less expensive amino acids. The implications of these results are discussed.
Limnological surveys from the pelagic zone of Lake Pont-de-Salars were undertaken during the 1993-1996 period, which included the emptying of the whole-lake in summer 1995 and the first post year refilling. This reservoir was warm and monomictic and was determined to vary between oligo- and meso-eutrophic status from year to year. Three sediment cores were collected from the deepest zone and frozen in situ during the short drying period, just after the emptying and before the refilling of the reservoir. Analysis of the relative abundance and vertical distribution of diatom taxa was undertaken. The diatom vertical distribution, evident by visual biostratigraphy, is confirmed by the correspondence analysis (CA) despite of absence of sediment dating.
The present work is based on a set of bottom trawl surveys performed in the Gulf of Lions between 1983 and 1992. A new method which couples the STATIS multitable approach with the logic of correspondence analysis (CoA) is proposed to study the stability of spatial organization of demersal assemblages in terms of species composition. This CoA version of STATIS has provided a clear representation of the stable part of the spatial structure of the assemblages. In addition, it gave an insight into the interannual variations of the distribution of each population around the reference structure. Our results showed that the demersal assemblages of the Gulf of Lions exhibited bold spatial structuring, mainly orientated along a bathymetric gradient. This gradient is structured around three major regions: the coast, the continental shelf and the continental slope. Despite sampling variations that occurred during the course of the study, the analysis showed a high degree of reproducibility for this spatial pattern. With the exception of Mullus surmuletus, the species considered in this investigation exhibit limited variations in their spatial distribution. Finally, in the absence of log-books covering the activities of commercial fishing vessels, these findings constitute a base of reference for the analysis of the dynamics of fishing fleets exploiting the demersal resources of the Gulf of Lions.
Factors influencing the spatial distribution of the bivalves Atactodea striata. Gafrarium tumidum and Anadara scapha were analysed on the south-west coast of New Caledonia, using a multivariate approach (correspondence analysis). A. striata is abundant on sandy beaches with a high coarse sand content. G. tumidum is preferentially distributed on substrates located close to the lower limit of neap tide and seems to be independent of sediment granulometry. A. scapha adults occur at lower bathymetric levels, with sediment composed of 40% medium, fine and very fine sand, and 30% very coarse and coarse sand. For this species, juvenile migration is suggested by the differential distribution of young and adults.
Seasonal growth of juvenile oysters (Crassostrea gigas) kept in an intensive upwelling system was studied from 1984 to 1986 in 60 to 90-day growth experiments. Saline ground water was used to produce Skeletonema costatum which was injected as food into the water supplying the upwelling system. Oyster density, water flow, phytoplankton concentration, temperature and frequency of food addition were controlled. Oyster growth was analysed with multidimensional contingency tables and correspondence analysis. The factors, in order of decreasing influence on growth, were temperature, food concentration and oyster density. A rearing strategy was deduced from the growth analysis for summer and winter. In summer, the density of 120,000 oysters/m2, the flow rate of 1 liter/d/oyster and the food concentration of 0.5 × 109 phytoplankton cells/litre gave the most interesting results. The oysters grew from 0.014 g to 2.2 g after 60 days. In winter, the heat exchanger was necessary to increase the temperature from the 5 °C naturally observed to the 11 °C required for valuable growth. Oyster density and food concentration were the same as in summer. For a flow rate equal to 3 liter/day/oyster, oysters grew from 0.01 g to 0.5 g within 100 days. The cost and profit computations were derived from these strategies. It was concluded that this type of nursery would be profitable in spring, summer, and autumn but not in winter due to the high cost of heating the water.