Computing the Jacobian in spatial models: an applied survey.

Despite attempts to get around the Jacobian in fitting spatial econometric models by using GMM and other approximations, it remains a central problem for maximum likelihood estimation. In principle, and for smaller data sets, the use of the eigenvalues of the spatial weights matrix provides a very rapid and satisfactory resolution. For somewhat larger problems, including those induced in spatial panel and dyadic (network) problems, solving the eigenproblem is not as attractive, and a number of alternatives have been proposed. This paper will survey chosen alternatives, and comment on their relative usefulness.Spatial autoregression; Maximum likelihood estimation; Jacobian computation; Econometric software.

Household Membership Decisions of Adult Children: Does Gender and Institutions Matter?

While several social, economic and financial indicators point to a growing convergence among European countries, striking differences still emerge in the timing of leaving home for adult children. In Southern countries (as Spain, Italy or Portugal) in 2001 more than 70 percent of young adults between 18 and 34 years of age live with their parents, whereas the corresponding number for Northern countries (like Denmark or the UK) is well below 40 percent. Existing literature highlights several factors explaining the different patterns in Europe: preferences and culture, labor market conditions, housing market as well as differences across the welfare states. In our work, we consider living arrangements of people 18-34 years old from 14 European countries (ECHP). We augment the informational content with indicators of labor, housing and marriage markets characteristics as well as proxy for the welfare states and culture. We investigate how they are intertwined with gender differencescoups, Living arrangements,duration analysis, government expenditures.

Metaphorizing the Holocaust: The Ethics of Comparison

Metaphorizing the Holocaust: The Ethics of Comparison  This paper focuses on the ethics of metaphor and other forms of comparison that invoke National Socialism and the Holocaust. It seeks to answer the question: Are there criteria on the basis of which we can judge whether metaphors and associated tropes “use” the Holocaust appropriately? In analyzing the thrust and workings of such comparisons, the paper also seeks to identify and clarify the terminology and concepts that allow productive discussion. In line with its conception of metaphor that is also rhetorical praxis, the paper focuses on specific controversies involving the metaphorization of the Holocaust, primarily in Germany and Austria. The paper develops its argument through the following process. First, it examines the rhetorical/political contexts in which claims of the Holocaust’s comparability (or incomparability) have been raised. Second, it presents a review (and view) of the nature of metaphor, metonymy, and synecdoche. It applies this framework to (a) comparisons of Saddam Hussein with Hitler in Germany in 1991; (b) the controversies surrounding the 2004 poster exhibition “The Holocaust on Your Plate” in Germany and Austria, with particular emphasis on the arguments and decisions in cases before the courts in those countries; and (c) the invocation of “Auschwitz” as metonym and synecdoche. These examples provide the basis for a discussion of the ethics of comparison. In its third and final section the paper argues that metaphor is by nature duplicitous, but that ethical practice involving Holocaust comparisons is possible if one is self-aware and sensitive to the necessity of seeing the “other” as oneself. The ethical framework proposed by the paper provides the basis for evaluationg the specific cases adduced

Degree of intervality of food webs: From body-size data to models

In food webs, the degree of intervality of consumers' diets is an indicator of the number of dimensions that are necessary to determine the niche of a species. Previous studies modeling food-web structure have shown that real networks are compatible with a high degree of diet contiguity. However, current models are also compatible with the opposite, namely that species' diets have relatively low contiguity. This is particularly true when one takes species' body size as a proxy for niche value, in which case the indeterminacy of diet contiguities provided by current models can be large. We propose a model that enables us to narrow down the range of possible values of diet contiguity. According to this model, we find that diet contiguity not only can be high, but must be high when species are ranked in ascending order of body size.This work was supported by a James S. Mc Donnell Foundation Research Award (R.G.), European Union Grant PIRG-GA-2010-277166 (R.G.), Spanish Ministerio de Ciencia e Innovación (MICINN) Grants FIS2009-13370-C02-01 A.A.), FIS2010-18639 (R.G.), PRODIEVO, and FIS2011-27569 (J.A.C.), Comunidad de Madrid Grant MODELICO-CM (J.A.C.) and by Generalitat de Catalunya 2009-SGR-838 (A.A.).Publicad

Multiscale analysis of the randomization limits of the chromosomal gene organization between Lepidoptera and Diptera

How chromosome gene organization and gene content evolve among distantly related and structurally malleable genomes remains unresolved. This is particularly the case when considering different insect orders. We have compared the highly contiguous genome assemblies of the lepidopteran Danaus plexippus and the dipteran Drosophila melanogaster, which shared a common ancestor around 290 Ma. The gene content of 23 out of 30 D. plexippus chromosomes was significantly associated with one or two of the six chromosomal elements of the Drosophila genome, denoting common ancestry. Despite the phylogenetic distance, 9.6% of the 1-to-1 orthologues still reside within the same ancestral genome neighbourhood. Furthermore, the comparison D. plexippus–Bombyx mori indicated that the rates of chromosome repatterning are lower in Lepidoptera than in Diptera, although still within the same order of magnitude. Concordantly, 14 developmental gene clusters showed a higher tendency to retain full or partial clustering in D. plexippus, further supporting that the physical association between the SuperHox and NK clusters existed in the ancestral bilaterian. Our results illuminate the scope and limits of the evolution of the gene organization and content of the ancestral chromosomes to the Lepidoptera and Diptera while helping reconstruct portions of the genome in their most recent common ancestor

The Role of Space in the Creation of Knowledge in Austria. Final Project Report.

Series: Research Reports of the Institute for Economic Geography and GIScienc

Are word association responses really the first words that come to mind?

Word association has been a popular tool for research in linguistics and psychology over the last century. The paradigm presents participants with a cue word and asks them to respond with the first associated word that comes to mind. Inferences about the structure and organisation of the lexicon have been made on the basis of the findings of word association tasks, and on the assumption that responses reflect the strongest link between words in the participants' vocabulary. The procedure adopted in traditional word association tasks does not guarantee that this is the case. This paper presents two experiments that aimed to determine whether or not participants make deliberate and strategic responses in word association tasks. Findings indicate that word association responses are likely to reflect the first word that participants activate in their lexicon. Keywords : psycholinguistics, Methodology, Word association, Working memory, Lexical organisation

Classification of eight dimensional perfect forms

In this paper, we classify the perfect lattices in dimension 8. There are 10916 of them. Our classification heavily relies on exploiting symmetry in polyhedral computations. Here we describe algorithms making the classification possible.Comment: 14 page