Frequency of word-use predicts rates of lexical evolution throughout Indo-European history

Greek speakers say "ovpa", Germans "schwanz'' and the French "queue'' to describe what English speakers call a 'tail', but all of these languages use a related form of 'two' to describe the number after one. Among more than 100 Indo-European languages and dialects, the words for some meanings (such as 'tail') evolve rapidly, being expressed across languages by dozens of unrelated words, while others evolve much more slowly-such as the number 'two', for which all Indo-European language speakers use the same related word-form(1). No general linguistic mechanism has been advanced to explain this striking variation in rates of lexical replacement among meanings. Here we use four large and divergent language corpora (English(2), Spanish(3), Russian(4) and Greek(5)) and a comparative database of 200 fundamental vocabulary meanings in 87 Indo-European languages(6) to show that the frequency with which these words are used in modern language predicts their rate of replacement over thousands of years of Indo-European language evolution. Across all 200 meanings, frequently used words evolve at slower rates and infrequently used words evolve more rapidly. This relationship holds separately and identically across parts of speech for each of the four language corpora, and accounts for approximately 50% of the variation in historical rates of lexical replacement. We propose that the frequency with which specific words are used in everyday language exerts a general and law-like influence on their rates of evolution. Our findings are consistent with social models of word change that emphasize the role of selection, and suggest that owing to the ways that humans use language, some words will evolve slowly and others rapidly across all languages.

Modeling cumulative evidence for freedom from disease with applications to BSE surveillance trials

This investigation deals with the question of when a particular population can be considered to be disease-free. The motivation is the case of BSE where specific birth cohorts may present distinct disease-free subpopulations. The specific objective is to develop a statistical approach suitable for documenting freedom of disease, in particular, freedom from BSE in birth cohorts. The approach is based upon a geometric waiting time distribution for the occurrence of positive surveillance results and formalizes the relationship between design prevalence, cumulative sample size and statistical power. The simple geometric waiting time model is further modified to account for the diagnostic sensitivity and specificity associated with the detection of disease. This is exemplified for BSE using two different models for the diagnostic sensitivity. The model is furthermore modified in such a way that a set of different values for the design prevalence in the surveillance streams can be accommodated (prevalence heterogeneity) and a general expression for the power function is developed. For illustration, numerical results for BSE suggest that currently (data status September 2004) a birth cohort of Danish cattle born after March 1999 is free from BSE with probability (power) of 0.8746 or 0.8509, depending on the choice of a model for the diagnostic sensitivity.

Evaluation of the cumulative evidence for freedom from BSE in birth cohorts

Substantial resources are used for surveillance of bovine spongiform encephalopathy (BSE) despite an extremely low detection rate, especially in healthy slaughtered cattle. We have developed a method based on the geometric waiting time distribution to establish and update the statistical evidence for BSE-freedom for defined birth cohorts using continued surveillance data. The results suggest that currently (data included till September 2004) a birth cohort of Danish cattle born after March 1999 is free from BSE with probability (power) of 0.8746 or 0.8509, depending on the choice of a model for the diagnostic sensitivity. These results apply to an assumed design prevalence of 1 in 10,000 and account for prevalence heterogeneity. The age-dependent, diagnostic sensitivity for the detection of BSE has been identified as major determinant of the power. The incorporation of heterogeneity was deemed adequate on scientific grounds and led to improved power values. We propose our model as a decision tool for possible future modification of the BSE surveillance and discuss public health and international trade implications.

Corrosion by sulfate reducing bacteria that utilize nitrate

16S rRNA gene sequencing was used to identify a sulfate-reducing bacterium (SRB) from a Danish North Sea oilfield water injection system. This species was cultivated, purified and subsequently identified as being >97% similar to Desulfovibrio gracilis. Like some other Desulfovibrio species this SRB, strain OP102, could reduce nitrate as an electron acceptor and produce ammonia in the absence of sulfate. In addition, in the presence of sulfate, when nitrate was dosed at 100 mg/l it was again reduced by the bacterium, with some ammonium production. Therefore, this mechanism could be important in oilfield systems where nitrate is applied to prevent sulfide generation by SRB which leads to reservoir souring. In static tests the influence of this Desulfovibrio on corrosion was assessed using carbon steel coupons, in the presence of sulfate and in the presence of sulfate with 100 mg/l nitrate. Corrosion rates were less than 1.5 mpy when coupons were incubated in the same water, with sulfate and with nitrate. Furthermore, the occurrence of pitting corrosion was fairly low under all circumstances.

A collaborative working environment for a large scale environmental model

Large scientific applications are usually developed, tested and used by a group of geographically dispersed scientists. The problems associated with the remote development and data sharing could be tackled by using collaborative working environments. There are various tools and software to create collaborative working environments. Some software frameworks, currently available, use these tools and software to enable remote job submission and file transfer on top of existing grid infrastructures. However, for many large scientific applications, further efforts need to be put to prepare a framework which offers application-centric facilities. Unified Air Pollution Model (UNI-DEM), developed by Danish Environmental Research Institute, is an example of a large scientific application which is in a continuous development and experimenting process by different institutes in Europe. This paper intends to design a collaborative distributed computing environment for UNI-DEM in particular but the framework proposed may also fit to many large scientific applications as well.

Computational complexity of weighted splitting schemes on parallel computers

In models of complicated physical-chemical processes operator splitting is very often applied in order to achieve sufficient accuracy as well as efficiency of the numerical solution. The recently rediscovered weighted splitting schemes have the great advantage of being parallelizable on operator level, which allows us to reduce the computational time if parallel computers are used. In this paper, the computational times needed for the weighted splitting methods are studied in comparison with the sequential (S) splitting and the Marchuk-Strang (MSt) splitting and are illustrated by numerical experiments performed by use of simplified versions of the Danish Eulerian model (DEM).

Different splitting techniques with application to air pollution models

Splitting techniques are commonly used when large-scale models, which appear in different fields of science and engineering, are treated numerically. Four types of splitting procedures are defined and discussed. The problem of the choice of a splitting procedure is investigated. Several numerical tests, by which the influence of the splitting errors on the accuracy of the results is studied, are given. It is shown that the splitting errors decrease linearly when (1) the splitting procedure is of first order and (2) the splitting errors are dominant. Three examples for splitting procedures used in all large-scale air pollution models are presented. Numerical results obtained by a particular air pollution model, Unified Danish Eulerian Model (UNI-DEM), are given and analysed.

Impact of future climate changes on high pollution levels

Changes in climate variability as well as changes in extreme weather and climate events in the 20th century, especially those that took place during the last two to three decades of the 20th century, have been discussed in many recent scientific publications. Attempts to project the results of such studies in the future have been made under different assumptions. In this paper, we have chosen one of the well-known scenarios predicting changes of the climate in the world during the last 30 years of the 21st century. This scenario is used, together with several general predictions related to the future climate, to produce three climatic scenarios. The derived climatic scenarios are used to calculate predictions for future pollution levels in Denmark and in Europe by applying the Unified Danish Eulerian Model (UNI-DEM), on a space domain containing the whole of Europe.

The effects of landscape modifications on the long-term persistence of animal populations

Background: The effects of landscape modifications on the long-term persistence of wild animal populations is of crucial importance to wildlife managers and conservation biologists, but obtaining experimental evidence using real landscapes is usually impossible. To circumvent this problem we used individual-based models (IBMs) of interacting animals in experimental modifications of a real Danish landscape. The models incorporate as much as possible of the behaviour and ecology of four species with contrasting life-history characteristics: skylark (Alauda arvensis), vole (Microtus agrestis), a ground beetle (Bembidion lampros) and a linyphiid spider (Erigone atra). This allows us to quantify the population implications of experimental modifications of landscape configuration and composition. Methodology/Principal Findings: Starting with a real agricultural landscape, we progressively reduced landscape complexity by (i) homogenizing habitat patch shapes, (ii) randomizing the locations of the patches, and (iii) randomizing the size of the patches. The first two steps increased landscape fragmentation. We assessed the effects of these manipulations on the long-term persistence of animal populations by measuring equilibrium population sizes and time to recovery after disturbance. Patch rearrangement and the presence of corridors had a large effect on the population dynamics of species whose local success depends on the surrounding terrain. Landscape modifications that reduced population sizes increased recovery times in the short-dispersing species, making small populations vulnerable to increasing disturbance. The species that were most strongly affected by large disturbances fluctuated little in population sizes in years when no perturbations took place. Significance: Traditional approaches to the management and conservation of populations use either classical methods of population analysis, which fail to adequately account for the spatial configurations of landscapes, or landscape ecology, which accounts for landscape structure but has difficulty predicting the dynamics of populations living in them. Here we show how realistic and replicable individual-based models can bridge the gap between non-spatial population theory and non-dynamic landscape ecology. A major strength of the approach is its ability to identify population vulnerabilities not detected by standard population viability analyses.

Le calunnie etniche nella lingua italiana

“Le calunnie etniche nella lingua italiana” (“Ethnic slurs in the Italian language”) is a very long chapter (c. 35.000 words) included in the second volume (pp. 513-587) of the multi-volume La cultura italiana, published by UTET in 2009-2010. (http://cultura.utet.it/cultura/catalogo/details.jsp?id=2076). La cultura italiana is an innovative multidisciplinary 12 volume (8.000 pages) work directed by the internationally acclaimed scientist Luigi Cavalli Sforza (http://en.wikipedia.org/wiki/Luigi_Luca_Cavalli-Sforza); each volume has been coordinated and edited by a very prominent Italian scholar, and every contribution has been written by academics with national and international reputations. The second volume of La cultura italiana has been coordinated by Professor Gian Luigi Beccaria, and is entirely devoted to language (“Lingue e linguaggi”). “Le calunnie etniche” brings together, for the first time in Italy, methodological issues and case studies on ethnic slurs in Italian and Italian dialects, and it particularly sheds new light on the semantic field of zingaro (gypsy), highlighting both the historical construction of the label, through the analysis of a huge amount of sources, and its social and political implication.

Contesting Thistlewood: slavery, agency and the limits of representation

This piece is a contribution to the exhibition catalogue of Barbadian / Canadian artist Joscelyn Gardner's exhibition, 'Bleeding & Breeding' curated by Olexander Wlasenko, January 14-February 12, 2012 in the Station Gallery, Whitby, Ontario, Canada. The piece examines the ways in which Gardner's Creole Portraits II (2007) and Creole Portraits III (2009) issue a provocative and carefully crafted contestation to the journals of the slave-owner and amateur botanist Thomas Thistlewood. It argues that while Thistlewood’s journals make raced and gendered bodies seemingly available to knowledge, incorporating them within the colonial archive as signs of subjection, Gardener’s portraits disrupt these acts of history and knowledge. Her artistic response marks a radical departure from the significant body of scholarship that has drawn on the Thistlewood journals to date. Creatively contesting his narratives’ dispossession of Creole female subjects and yet aware of the problems of innocent recovery, her works style representations that retain the consciousness and effect of historical erasure. Through an oxymoronic aesthetic that assembles a highly crafted verisimilitude alongside the condition of invisibility and brings atrocity into the orbit of the aesthetic, these portraits force us to question what stakes are involved in bringing the lives of the enslaved and violated back into regimes of representation.

Richard le Scandinave? Héroïsme et métissage culturel dans le Roman de Rou de Wace

This article explores the bilingual and bicultural identity of Normandy revealed by Wace's depiction of Duke Richard the Fearless in the Roman de Rou. The anecdotes that open the Troisieme Partie of the Rou are analysed in the light of Scandinavian analogues, in particular the Saga of Grettir. This allows us to discern in Wace's stories a dual tradition, with romance and scandinavian strands that were not always mutually compatible, resulting in narrative tensions that had hitherto remained unexplained. In particular, the fearless duke takes on connotations of mental instability that would only have been recognised by the Normans of Danish origin.

Back to the margins in search of the core: "Foreign Land"'s geography of exclusion

The crisis of the national project in the early 1990s, caused by a short-lived but disastrous government, led Brazilian art cinema, for the first time, to look at itself as periphery and re-approach the old colonial center, Portugal. Terra estrangeira/Foreign Land (Walter Salles & Daniela Thomas, Brazil/Portugal, 1995), a film about Brazilian exiles in Portugal, is the best illustration of this perspective shift which provides a new sense of Brazil’s scale and position within a global context. Shot mainly on location in São Paulo, Lisbon and Cape Verde, it promotes the encounter of Lusophone peoples who find a common ground in their marginal situation. Rather than as a former empire, Portugal is defined by its situation at the edge of Europe and by beliefs such as Sebastianism, whose origins go back to the time when the country was dominated by Spain. As a result, notions of “core” or “center” are devolved to the realm of myth. The film’s carefully crafted dialogue combines Brazilian, Portuguese and Creole linguistic peculiarities into a common dialect of exclusion, while language puns trigger visual rhymes which refer back to the Cinema Novo (the Brazilian New Wave) repertoire and restage the imaginary of the discovery turned into unfulfilled utopia. The main characters also acquire historical resonances, as they are depicted as descendants of Iberian conquistadors turned into smugglers of precious stones in the present. Their activities define a circuit of international exchange which resonates with that of globalized cinema, a realm in which Foreign Land, made up of citations and homage to other cinemas, tries to retrieve a sense of belonging.