bluuebunny/crossref_metadata_2025_split huggingface dataset:
Penguins from space: faecal stains reveal the location of emperor penguin colonies
Authors: Fretwell Peter T. , Trathan Philip N. 
Published: June 2009

ABSTRACTAim  To map and assess the breeding distribution of emperor penguins (Aptenodytes forsteri) using remote sensing.Location  Pan‐Antarctic.Methods  Using Landsat ETM satellite images downloaded from the Landsat Image Mosaic of Antarctica (LIMA), we detect faecal staining of ice by emperor penguins associated with their colony locations. Emperor penguins breed on sea ice, and their colonies exist in situ between May and December each year. Faecal staining at these colony locations shows on Landsat imagery as brown patches, the only staining of this colour on sea ice. This staining can therefore be used as an analogue for colony locations. The whole continental coastline has been analysed, and each possible signal has been identified visually and checked by spectral analysis. In areas where LIMA data are unsuitable, freely available Landsat imagery has been supplemented.Results  We have identified colony locations of emperor penguins at a total of 38 sites. Of these, 10 are new locations, and six previously known colony locations have been repositioned (by over 10 km) due to poor geographical information in old records. Six colony locations, all from old or unconfirmed records, were not found or have disappeared.Main conclusions  We present a new pan‐Antarctic species distribution of emperor penguins mapped from space. In one synoptic survey we locate extant emperor penguin colonies, a species previously poorly mapped due to its unique breeding habits, and provide a vital geographical resource for future studies of an iconic species believed to be vulnerable to future climate change.
Colonial Legacies and Repertoires of “Ethnic” Violence: The Case of Western India, 1941–2002
Authors: DESAI MANALI 
Published: June 2009

AbstractThe post‐colonial state is held to be a weak state whose ease of capture reduces its capacity to suppress violence. The focus on the state, however, risks neglecting the ways in which violence is deployed to render the state weak in popular perception. This perception in turn legitimates claims for a foundational shift in the basis of power. In this paper, the concept of “repertoire” as first used by Charles Tilly, is used to analyze continuities and discontinuities in the development of the “ethnic riot” in urban, western India. As an “extreme” case in which riots have shown considerable durability over time, it highlights a key point, namely, that riots can form part of a strategy of power by simultaneously projecting themselves as popular insurrection and constructing a perception of the state as weak. The persistence of this repertoire, it is further argued, derives from the historical specificities of colonial state formation which promoted an ethnically imagined and hierarchized polity, as well as political struggles which weakened alternative forms of community.
The Cultural Agency of Elites: Awolowo and the Re‐making of the Yoruba
Authors: ADEBANWI WALE 
Published: June 2009

AbstractThe mystique of eliteness is a quality that is cultivated or constructed overtime. Here, I examine agency– a culturally‐specific, consolidated stream of composite actions and interactions that are geared towards specific social endeavours, and structure ‐representing conventions and social parameters through which agency and social practices are performed and become performative, by tracing the historical‐political context in which Chief Obáfémi Awólówò, the acknowledged leader of the Yorùbá of Nigeria, rose to politico‐cultural prominence and succeeded to the “throne” of the Yorùbá progenitor, Odùduwà. I argue that through this succession, Awólówò became the “modern Odùduwà” and the central signifier of Yorubaness in 20th Century Nigeria and beyond.
Martial Law and Military Power in the Construction of the South African State: Jan Smuts and the “Solid Guarantee of Force” 1899–1924
Authors: HYSLOP JONATHAN 
Published: June 2009

AbstractThis paper seeks to provide a new approach to analysing the crucial period of the building of the South African state between the Boer War and 1924. Drawing on the sociology of Michael Mann, it argues that the construction of networks of military power was of central and partly autonomous importance in giving shape to the new state. It goes on to contend that this generated a legal order which was in many ways shaped by practices which derived from martial law. The paper also asserts that these questions of military power and martial law need to be analysed within a framework which does not limit itself to the boundaries of the South African state itself, but is placed within the wider context of the British Empire and the southern African region. A biographical exploration the role of Jan Smuts as the key leader is used to focus the paper's study of this process of state‐making.
Colonial Oppression, Gender, and Women in the Irish Diaspora
Authors: RADOSH POLLY 
Published: June 2009

AbstractThis paper explores the relationship between colonial oppression in pre‐famine Ireland and the development of gender patterns that fostered uncommon social and familial roles for women. In post‐famine Ireland women's traditional family roles illustrate cultural empowerment that combined with the pull factors of employment opportunities to spawn higher female than male emigration at the same time that patriarchal oppression restricted women's full social participation in Ireland and limited their authority to specific domains of family life. Cultural changes in post‐famine Ireland, including increased power for the Catholic Church, mothers' socialization of children to the moral teachings of the Church, delayed marriage, and permanent celibacy among large segments of the population, intersected to produce unique patterns of migration. For women who immigrated to the United States, the cultural background of colonial oppression instilled values that respected independence and employment. In the case of the Irish, colonial oppression initiated gender patterns that pushed women to greater familial power and occupational independence than was typical of other ethnic groups.
Effect of calcium from dairy and dietary supplements on faecal fat excretion: a meta‐analysis of randomized controlled trials
Authors: Christensen R. , Lorenzen J. K. , Svith C. R. , Bartels E. M. , Melanson E. L. , Saris W. H. , Tremblay A. , Astrup A. 
Published: June 2009

SummaryObservational studies have found that dietary calcium intake is inversely related to body weight and body fat mass. One explanatory mechanism is that dietary calcium increases faecal fat excretion. To examine the effect of calcium from dietary supplements or dairy products on quantitative faecal fat excretion, we performed a systematic review with meta‐analysis. We included randomized, controlled trials of calcium (supplements or dairy) in healthy subjects, where faecal fat excretion was measured. Meta‐analyses used random‐effects models with changes in faecal fat excreted expressed as standardized mean differences, as the studies assessed the same outcome but measured in different ways.An increased calcium intake resulted in increased excretion of faecal fat by a standardized mean difference of 0.99 (95% confidence intervals: 0.63–1.34; P < 0.0001; expected to correspond to ∼2g day−1) with moderate heterogeneity (I2 = 49.5%) indicating some inconsistency in trial outcomes. However, the dairy trials showed homogeneous outcomes (I2=0%) indicating consistency among these trials. We estimated that increasing the dairy calcium intake by 1241 mg day−1 resulted in an increase in faecal fat of 5.2 (1.6–8.8) g day−1. In conclusion, dietary calcium has the potential to increase faecal fat excretion to an extent that could be relevant for prevention of weight (re‐)gain. Long‐term studies are required to establish its potential contribution.
ROUTES TO HIGHER‐ORDER ACCURACY IN PARAMETRIC INFERENCE
Authors: Young G. Alastair 
Published: June 2009

SummaryDevelopments in the theory of frequentist parametric inference in recent decades have been driven largely by the desire to achieve higher‐order accuracy, in particular distributional approximations that improve on first‐order asymptotic theory by one or two orders of magnitude. At the same time, much methodology is specifically designed to respect key principles of parametric inference, in particular conditionality principles. Two main routes to higher‐order accuracy have emerged: analytic methods based on ‘small‐sample asymptotics’, and simulation, or ‘bootstrap’, approaches. It is argued here that, of these, the simulation methodology provides a simple and effective approach, which nevertheless retains finer inferential components of theory. The paper seeks to track likely developments of parametric inference, in an era dominated by the emergence of methodological problems involving complex dependences and/or high‐dimensional parameters that typically exceed available data sample sizes.
The Limitations of using School League Tables to Inform School Choice
Authors: Leckie George , Goldstein Harvey 
Published: June 2009

SummaryIn England, so-called ‘league tables’ based on examination results and test scores are published annually, ostensibly to inform parental choice of secondary schools. A crucial limitation of these tables is that the most recent published information is based on the current performance of a cohort of pupils who entered secondary schools several years earlier, whereas for choosing a school it is the future performance of the current cohort that is of interest. We show that there is substantial uncertainty in predicting such future performance and that incorporating this uncertainty leads to a situation where only a handful of schools’ future performances can be separated from both the overall mean and from one another with an acceptable degree of precision. This suggests that school league tables, including value-added tables, have very little to offer as guides to school choice.
Modelling Long-Term Pan-European Population Change from 1870 to 2000 by Using Geographical Information Systems
Authors: Gregory Ian N. , Marti-Henneberg Jordi , Tapiador Francisco J. 
Published: June 2009

SummaryThe paper presents work that creates a geographical information system database of European census data from 1870 to 2000. The database is integrated over space and time. Spatially it consists of regional level data for most of Europe; temporally it covers every decade from 1870 to 2000. Crucially the data have been interpolated onto the administrative units that were available in 2000, thus allowing contemporary population patterns to be understood in the light of the changes that have occurred since the late 19th century. The effect of interpolation error on the resulting estimates is explored. This database will provide a framework for much future analysis on long-term Europewide demographic processes over space and time.
Modelling the Probability Distribution of Prize Winnings in the UK National Lottery: Consequences of Conscious Selection
Authors: Baker R. D. , McHale I. G. 
Published: June 2009

SummaryIn the statistical and economics literature on lotteries, the problem of designing attractive games has been studied by using models in which sales are a function of the structure of prizes. Recently the prize structure has been proxied by using the moments of the prize distribution. Such modelling is a vital input into the process of designing appealing new lottery games that can generate large revenues for good causes. We show how conscious selection, the process by which lottery players choose numbers non-randomly, complicates the multivariate distribution of prize winners by introducing massive overdispersion of numbers of winners, and large correlations between the numbers of different types of prize winner. Although it is possible intuitively to reach a qualitative understanding of the data, an a priori model does not fit well. We therefore construct an empirical model of the joint distribution of prize winners and use it to calculate the moments of ticket value as a function of sales. The new model gives much higher estimates of ticket value moments, particularly skewness, than previously obtained. Our results will have consequences for policy decisions regarding game design. A spin-off result is that, on the basis of the results of model fitting, lottery players may increase the expected value of their ticket by strategically choosing numbers which are less popular with other lottery players.
Unemployed and Their Caseworkers: Should They be Friends or Foes?
Authors: Behncke Stefanie , Frölich Markus , Lechner Michael 
Published: June 2009

Summary
In many countries, caseworkers in public employment offices have dual roles of counselling and monitoring unemployed people. These roles often conflict, which results in important caseworker heterogeneity: some consider providing services to their clients and satisfying their demands as their primary task. However, others may pursue their own strategies, even against the will of the unemployed person. They may assign jobs and labour market programmes without the consent of the unemployed person. On the basis of a very detailed linked jobseeker–caseworker data set for Switzerland, we investigate the effects of caseworkers’ co-operativeness on the probabilities of employment of their clients. Modified statistical matching methods reveal that caseworkers who place less emphasis on a co-operative and harmonic relationship with their clients increase their chances of employment in the short and medium term.
Teacher Shortages, Teacher Contracts and Their Effect on Education in Africa
Authors: Bourdon Jean , Frölich Markus , Michaelowa Katharina 
Published: June 2009

Summary
To enhance primary enrolment rates, many African countries have launched large teacher recruitment programmes in recent years. Given tight budgetary constraints, teachers are no longer employed in civil service positions, but on the basis of (fixed term) contracts typically implying considerably lower salaries and a sharply reduced amount of professional training. We analyse the effect of this change on educational quality in Niger, Togo and Mali, on the basis of very informative data, which are comparable across these countries. We use a variety of estimation techniques, including a non-parametric estimation of quantile treatment effects. Our results demonstrate that contract teachers tend to reduce inequalities in student outcomes. Overall, the effects are positive in Mali, somewhat mixed in Togo and negative in Niger. This ordering is consistent with theoretical expectations related to the manner in which contract teacher programmes were implemented differently in each of the three countries under study.
Embedded Experiments in Repeated and Overlapping Surveys
Authors: Chipperfield James , Bell Philip 
Published: June 2009

Summary
Statistical agencies make changes to the data collection methodology of their surveys to improve the quality of the data collected or to improve the efficiency with which they are collected. For reasons of cost it may not be possible to estimate the effect of such a change on survey estimates or response rates reliably, without conducting an experiment that is embedded in the survey which involves enumerating some respondents by using the new method and some under the existing method. Embedded experiments are often designed for repeated and overlapping surveys; however, previous methods use sample data from only one occasion. The paper focuses on estimating the effect of a methodological change on estimates in the case of repeated surveys with overlapping samples from several occasions. Efficient design of an embedded experiment that covers more than one time point is also mentioned. All inference is unbiased over an assumed measurement model, the experimental design and the complex sample design. Other benefits of the approach proposed include the following: it exploits the correlation between the samples on each occasion to improve estimates of treatment effects; treatment effects are allowed to vary over time; it is robust against incorrectly rejecting the null hypothesis of no treatment effect; it allows a wide set of alternative experimental designs. This paper applies the methodology proposed to the Australian Labour Force Survey to measure the effect of replacing pen-and-paper interviewing with computer-assisted interviewing. This application considered alternative experimental designs in terms of their statistical efficiency and their risks to maintaining a consistent series. The approach proposed is significantly more efficient than using only 1 month of sample data in estimation.
Two-Step Estimation for Inhomogeneous Spatial Point Processes
Authors: Waagepetersen Rasmus , Guan Yongtao 
Published: June 2009

SummaryThe paper is concerned with parameter estimation for inhomogeneous spatial point processes with a regression model for the intensity function and tractable second-order properties (K-function). Regression parameters are estimated by using a Poisson likelihood score estimating function and in the second step minimum contrast estimation is applied for the residual clustering parameters. Asymptotic normality of parameter estimates is established under certain mixing conditions and we exemplify how the results may be applied in ecological studies of rainforests.
Fully Exponential Laplace Approximations for the Joint Modelling of Survival and Longitudinal Data
Authors: Rizopoulos Dimitris , Verbeke Geert , Lesaffre Emmanuel 
Published: June 2009

SummaryA common objective in longitudinal studies is the joint modelling of a longitudinal response with a time-to-event outcome. Random effects are typically used in the joint modelling framework to explain the interrelationships between these two processes. However, estimation in the presence of random effects involves intractable integrals requiring numerical integration. We propose a new computational approach for fitting such models that is based on the Laplace method for integrals that makes the consideration of high dimensional random-effects structures feasible. Contrary to the standard Laplace approximation, our method requires much fewer repeated measurements per individual to produce reliable results.
A General Dynamical Statistical model with Causal Interpretation
Authors: Commenges Daniel , Gégout-Petit Anne 
Published: June 2009

SummaryWe develop a general dynamical model as a framework for causal interpretation. We first state a criterion of local independence in terms of measurability of processes that are involved in the Doob–Meyer decomposition of stochastic processes; then we define direct and indirect influence. We propose a definition of causal influence using the concepts of a ‘physical system’. This framework makes it possible to link descriptive and explicative statistical models, and encompasses quantitative processes and events. One of the features of the paper is the clear distinction between the model for the system and the model for the observation. We give a dynamical representation of a conventional joint model for human immunodeficiency virus load and CD4 cell counts. We show its inadequacy to capture causal influences whereas in contrast known mechanisms of infection by the human immunodeficiency virus can be expressed directly through a system of differential equations.
Deconvolution Methods for Non-Parametric Inference in two-level Mixed Models
Authors: Hall Peter , Maiti Tapabrata 
Published: June 2009

SummaryWe develop a general non-parametric approach to the analysis of clustered data via random effects. Assuming only that the link function is known, the regression functions and the distributions of both cluster means and observation errors are treated non-parametrically. Our argument proceeds by viewing the observation error at the cluster mean level as though it were a measurement error in an errors-in-variables problem, and using a deconvolution argument to access the distribution of the cluster mean. A Fourier deconvolution approach could be used if the distribution of the error-in-variables were known. In practice it is unknown, of course, but it can be estimated from repeated measurements, and in this way deconvolution can be achieved in an approximate sense. This argument might be interpreted as implying that large numbers of replicates are necessary for each cluster mean distribution, but that is not so; we avoid this requirement by incorporating statistical smoothing over values of nearby explanatory variables. Empirical rules are developed for the choice of smoothing parameter. Numerical simulations, and an application to real data, demonstrate small sample performance for this package of methodology. We also develop theory establishing statistical consistency.
Invariant Co-Ordinate Selection
Authors: Tyler David E. , Critchley Frank , Dümbgen Lutz , Oja Hannu 
Published: June 2009

SummaryA general method for exploring multivariate data by comparing different estimates of multivariate scatter is presented. The method is based on the eigenvalue–eigenvector decomposition of one scatter matrix relative to another. In particular, it is shown that the eigenvectors can be used to generate an affine invariant co-ordinate system for the multivariate data. Consequently, we view this method as a method for invariant co-ordinate selection. By plotting the data with respect to this new invariant co-ordinate system, various data structures can be revealed. For example, under certain independent components models, it is shown that the invariant co- ordinates correspond to the independent components. Another example pertains to mixtures of elliptical distributions. In this case, it is shown that a subset of the invariant co-ordinates corresponds to Fisher’s linear discriminant subspace, even though the class identifications of the data points are unknown. Some illustrative examples are given.
Copula Structure Analysis
Authors: Klüppelberg Claudia , Kuhn Gabriel 
Published: June 2009

SummaryWe extend the standard approach of correlation structure analysis for dimension reduction of high dimensional statistical data. The classical assumption of a linear model for the distribution of a random vector is replaced by the weaker assumption of a model for the copula. For elliptical copulas a correlation-like structure remains, but different margins and non-existence of moments are possible. After introducing the new concept and deriving some theoretical results we observe in a simulation study the performance of the estimators: the theoretical asymptotic behaviour of the statistics can be observed even for small sample sizes. Finally, we show our method at work for a financial data set and explain differences between our copula-based approach and the classical approach. Our new method yielear models also.