Log-linear Analysis Of Contingency Tables Research Articles

Ticks and the city - are there any differences between city parks and natural forests in terms of tick abundance and prevalence of spirochaetes?

BackgroundIxodes ricinus ticks are commonly encountered in either natural or urban areas, contributing to Lyme disease agents Borreliella [(Borrelia burgdorferi (sensu lato)] spp. and Borrelia miyamotoi enzootic cycles in cities. It is an actual problem whether urbanization affects pathogen circulation and therefore risk of infection. The aim of the study was to evaluate main tick-borne disease risk factors in natural, endemic areas of north-east (NE) Poland (Białowieża) and urban areas of central Poland (Warsaw), measuring tick abundance/density, prevalence of infection with spirochaetes and diversity of these pathogens in spring-early summer and late summer-autumn periods between 2012 and 2015.MethodsQuesting I. ricinus ticks were collected from three urban sites in Warsaw, central Poland and three natural sites in Białowieża, NE Poland. A total of 2993 ticks were analyzed for the presence of Borreliella spp. and/or Borrelia miyamotoi DNA by PCR. Tick abundance was analyzed by General Linear Models (GLM). Prevalence and distribution of spirochaetes was analyzed by Maximum Likelihood techniques based on log-linear analysis of contingency tables (HILOGLINEAR). Species typing and molecular phylogenetic analysis based on the sequenced flaB marker were carried out.ResultsOverall 4617 I. ricinus ticks were collected (2258 nymphs and 2359 adults). We report well established population of ticks in urban areas (10.1 ± 0.9 ticks/100 m2), as in endemic natural areas with higher mean tick abundance (16.5 ± 1.5 ticks/100 m2). Tick densities were the highest in spring-early summer in both types of areas. We observed no effect of the type of area on Borreliella spp. and B. miyamotoi presence in ticks, resulting in similar prevalence of spirochaetes in urban and natural areas [10.9% (95% CI: 9.7–12.2%) vs 12.4% (95% CI: 10.1–15.1%), respectively]. Prevalence of spirochaetes was significantly higher in the summer-autumn period than in the spring-early summer [15.0% (95% CI: 12.8–17.5%) vs 10.4% (95% CI: 9.2–11.6%), respectively]. We have detected six species of bacteria present in both types of areas, with different frequencies: dominance of B. afzelii (69.3%) in urban and B. garinii (48.1%) in natural areas. Although we observed higher tick densities in forests than in maintained parks, the prevalence of spirochaetes was significantly higher in the latter [9.8% (95% CI: 8.6–11.0%) vs 17.5% (95% CI: 14.4–20.5%)].ConclusionsSurprisingly, a similar risk of infection with Borreliella spp. and/or B. miyamotoi was discovered in highly- and low-transformed areas. We suggest that the awareness of presence of these disease agents in cities should be raised.

Hereditary Risk and Child Abuse: Their Relative Roles in Type of Schizophrenia

This study tests to see if different types of childhood abuse precede specific symptoms of schizophrenia. The analyses also examine for an interactive effect of hereditary risk, using family history of serious mental illness as a proxy variable. Data are taken from the cumulative anonymous records of patients with schizophrenia (N = 642) from a large state hospital in the northeastern U. S. Childhood abuse was separated into two domains: physical abuse and emotional/verbal abuse. Log-linear analysis of contingency tables uncovered a powerful pattern: risk for positive symptoms of schizophrenia is significantly elevated by two conditions: history of childhood abuse in combination with no history of serious mental illness within the family. The implications of these findings are discussed.

Partitions of Pearson’s Chi-square statistic for frequency tables: a comprehensive account

Pearson's Chi-square statistic for frequency tables depends on what is hypothesized as the expected frequencies. Its partitions also depend on the hypothesis. Lancaster (J R Stat Soc B 13:242---249, 1951) proposed ANOVA-like partitions of Pearson's statistic under several representative hypotheses about the expected frequencies. His expositions were, however, not entirely clear. In this paper, we clarify his method of derivations, and extend it to more general situations. A comparison is made with analogous decompositions of the log likelihood ratio statistic associated with log-linear analysis of contingency tables.

ANALYSING ASSOCIATIONS AMONG MORE THAN TWO SPECIES

Although the existence of higher order associations has been proved, interspecific association is generally treated as a pair-wise phenomenon. Its possible reason is that although pair-wise association is only an imperfect description of the relationships among species, its methods are simple and well known. Unfortunately, the complexity of vegetation can not be described by such simplex methods. This paper shows two methods which enable detailed analysis of higher-order associations: Juhasz-Nagy's information theory functions and the log-linear contingency table analysis. From mathematical point of view, the two methods are closely related (both methods measure the non-randomness in the multi-way contingency tables). On the other hand, their theoretical backgrounds are different. The log-linear contingency table analysis was developed by statisticians to solve general statistical problems, while Juhasz-Nagy's approach was developed by a biologist to solve biological problems. The aim of this paper is to show how these two approaches decompose the total association, to point at the similarities and differences between the two approaches, and by this way to facilitate the analysis of higher order associations.

The relationship between Juhász-Nagy's information theory functions and the log-linear contingency table analysis

Spatial pattern of the vegetation, due to its complexity, cannot be described by ad hoc indices. It requires a solid methodological basis, which can describe different levels of patterns (patterns of populations, coalitions and whole community) in the same framework. There are two methods, which seem to be appropriate for this purpose: Juhász-Nagy's information theory functions and log-linear contingency table analysis. This paper shows that from mathematical point of view they are close relatives. The main advantage of Juhász-Nagy's approach that it is developed to describe spatial pattern of the vegetation, therefore biological meaning of the functions is a central part of the approach. Whereas log-linear contingency table analysis is a general statistical method without any special (biological) meaning of terms. On the other hand, it is a well-known statistical method, while most of the biologists are unfamiliar in information theory. The relationship between these two approaches makes it possible to hybridise their advantages.

The abundance and development of cavities in Eucalyptus trees: a case study in the montane forests of Victoria, southeastern Australia

A study of the abundance of cavities in Eucalyptus regnans, Eucalyptus delegatensis, Eucalyptus nitens, Eucalyptus obliqua and Eucalyptus cypellocarpa is described. The investigation used a database of 2315 living and dead trees with cavities, measured on 523 sites each of 3 ha throughout the montane ash forests of the Central Highlands of Victoria, southeastern Australia. Poisson regression analysis was used to examine the relationships between the number and type of cavities and a range of attributes of trees. These analyses demonstrated that, for all species of trees, the abundance of holes, fissures and hollow branches increased with tree diameter. Log-linear analysis of contingency tables demonstrated that various combinations of cavity types typically occur. Patterns of co-occurrence of cavities changed significantly according to the diameter, height and form of trees. The application of restricted maximum likelihood estimation (REML) for examining multi-level data, enabled the relatioships between the number of cavities, tree characteristics and site parameters to be analysed The characteristics of trees that were important were height, diameter and form. Site parameter that had a significant influence on the total number of cavities in trees included slope, latitude and stand age. This highlights the range of factors, at several measured spatial scales, that may influence the development of cavities in Eucalyptus trees. Although the various relationships derived in this study were highly significant, the statistical models had limited predictive ability. Thus for any given tree the development of cavities will be influenced by site and tree attributes as well as highly stochastic episodic events that may occur during its lifetime. The key findings from the study are discussed in terms of their relevance to forest wildlife management.

A comparison of some statistical techniques for road accident analysis

At the TRRL/SWOV Workshop on Accident Analysis Methodology, held in Amsterdam in 1988, the need to establish a methodology for the analysis of road accidents was firmly stated by all participants. Data from different countries cannot be compared because there is no agreement on research methodology, data collection, and analysis. Linear and log-linear models are regularly used for the analysis of such data. This paper discusses the background of these models and the model assumptions. It is stated that two relevant and fundamentally different classes of models exist. However, in most cases the difference between these classes remains implicit. These classes of models are called design oriented and object oriented models. Within the context of linear models, the basic assumptions deal with this distinction and the generalization of linear to log-linear models. It is argued that there are advantages and disadvantages for each choice and that a check on the tenability of a particular model is to be recommended. Two different types of generalized linear models, both object-oriented, are used by SWOV and TRRL for the analysis of accidents of road users or on particular road locations. The qualitative data analysis (QDA) models used at SWOV are primarily descriptive and useful for model exploration. The generalized linear interactive modeling (GLIM) technique used at TRRL has stricter assumptions, but is better suited for model testing. In order to compare these models, a number of analyses has been carried out on roundabout data from TRRL. The outcomes are consistent and highly comparable. The results show that for this kind of data these two types of models are to be preferred over classical multiple linear regression analysis (MLR) and log-linear analysis of contingency tables (LLA). QDA turned out to be the most powerful in data exploration. A QDA analysis showed that the dominant accident type of entering and circulating accidents had a different relation with the road and traffic characteristics of the roundabouts than the other accident types and should be analyzed separately. Furthermore, it was shown by a QDA analysis that the choice of a log-link function was preferable over an identity relation as used in MLR. This log-link function in combination with the choice of a Poisson error distribution results in a GLIM model with parameter estimates and errorbounds for these estimates. The errorbounds can be used as an indication of the reliability of the parameters. It is stated that the combination of QDA and GLIM is most powerful for the analysis of this type of problems.

Two Multivariate Methods for Analyzing Small Group Interaction

This article compares the advantages and disadvantages of two multivariate methods for the analysis of small grolup communication data, log-linear contingency table analysis and multivariate analysis of variance, in the context of ani experimental design. The independent conditions were discussion procedure, task solution multiplicity, and discussion topic. Participant communication behaviors, the dependent variables, were coded into a mix of 15 task social, and procedural categories. The analyses of communication indicated that log-linzear analyasis produced thle most complex models for various behaviors, including both single-factor and multifactor termns. Multivariate analysis of variance (MANOVA) findings at tlte grolup level provided the most parsimonious explanations, with a main effect of discussion procedure. Some MANOVA results at the individual level were similar to loglitnear mnodels in their complexity, whereas others duplicated the results of the group-level MANOVA. The differing outcomes from these methods point to several design considerations that should be taken account when choosing a statistical test for group communication data.

A Note on “Log-Linear Analysis of Contingency Tables”

A Note on “Log-Linear Analysis of Contingency Tables”

The Economics of Safety Deregulation: Lives and Dollars Lost Due to Repeal of Motorcycle Helmet Laws

Between 1976 and 1980, 28 state legislatures in the United States repealed or weakened their motorcycle helmet-use laws. This paper estimates the number of excess deaths attributable to this deregulatory activity, and the associated economic costs to society. Because of data limitations, no attempt was made to estimate the excess nonfatal injuries and associated costs. We applied a variant of log-linear contingency-table analysis to the monthly counts of motorcycle fatalities in the 48 contiguous states over the period 1975 through 1980. This analysis produced estimates of the total number of deaths, in each of 36 age-sex groups, that could be attributed to changes in the helmet laws. We then estimated the direct and indirect economic costs associated with fatalities in each age-sex group. Our findings indicate that 516 excess deaths occurred in 1980 in the 28 states that weakened or repealed their helmet laws. This represented 24 percent of the total motorcycle fatalities occurring in those states. Women and younger cyclists of both sexes comprised a disproportionate share of excess deaths. The economic costs to society that are associated with the excess fatalities resulting from the repeals of helmet laws total at least $180 million.

Log-linear analysis of contingency tables: An introduction for historians with an application to Thernstrom on the “Floating Proletariat”

Suppose a researcher has information on several attributes of a collection of individuals and that the data he has are available only in qualitative (synonyms are categorical, discrete, polytomous, or ordinal- or nominal- level), as opposed to quantitative (continuous or interval-level) form. For instance, imagine that his information is about yes or no votes, occupational classes, or age groups, but none is in the form of, say, the dollar amounts of property held (not broken into categories) or the length of residence, in months or years, at a particular location. Then he might construct tables, such as Table 1, which show how many people have each set of traits; for example, how many young, unskilled, childless men in a sample were found in both the Boston census schedule in 1880 and the city directory in 1890. When there is very little information available, say, data on only two or three variables, commonsensical methods of analysis may suffice. But what should one do when one is confronted by such monsters as the eighty-celled four-way Table 1?

University Students: A Change in Expectations and Aspirations Over the Decade

This longitudinal study examines patterns of change in life goal aspirations and educational expectations of 2, 786 women and men graduating from a major research university between the years 1968 and 1979. To ascertain specific patterns of change, the relationships among each goal, sex and decade were explored using log-linear contingency table analysis. Findings indicate that life goal aspirations and educational expectations have changed over the decade of the 1970s. Women are now aspiring to combinations offamily and career. Though men do show currents of interest in family, their movement away from career is concomitant with an increased involvement in leisure pursuits. These trends suggest a conflict between marriage/family and career goals for women and men.

Two PASCAL programs for managing observational data bases and for performing multivariate information analysis and log-linear contingency table analysis of sequential and nonsequential data

Two PASCAL programs for managing observational data bases and for performing multivariate information analysis and log-linear contingency table analysis of sequential and nonsequential data

Social Cleavages and Party Choice in Israel: A Log-Linear Analysis

This article attempts to fill two gaps in the literature on individual party choice. First, it deals with hitherto unanswered questions about relationships between social cleavages and party choice in Israel. Second, the article attempts to overcome methodological problems arising in the multivariate analysis of multiparty systems by utilizing Goodman's method of log-linear contingency table analysis. In the sample, occupation is not as strongly related to party choice as is a nonhierarchical dimension of economic position, sector of the economy. Ethnicity is modestly related to party choice, but hypotheses that the relationship is affected by place of birth, age, or other variables are disconfirmed. Hypotheses that the relationship between religiosity and party choice is affected by economic position are also disconfirmed. The advantages of using log linear contingency table analysis are demonstrated.

Religious Involvement and Political Behavior: a Log-linear Analysis of White Americans, 1952-1968

The political distinctiveness of major American religious groupings is well-documented, but the role of church attendance in maintaining these cleavages has been unclear. Analysis of white respondents in five national surveys covering 16 years reveals that church attendance is significantly related to party identification and presidential vote in all but one instance. Application of Goodman's log-linear analysis of contingency tables shows that higher rates of church attendance are related to non-Democratic preferences among Protestants and Democratic preferences among Catholics. In several years, the relationship depends as well upon region of residence. The effects, particularly on the vote, seem to be changing systematically over time as the South becomes politically similar to the non-South.