Regional variation of habitat tolerance by some European spiders (Araneae) - a review

The data presented by HÄNGGI et al. (1995) and BOLAÑOS (2003) on the habitats of a large number of European spiders are examined, most of which appear to show non-specific preferences. The abundance and frequency peaks of the 384 species graphs (HÄNGGI et al. 1995) can be explained by assuming that habitat tolerance varies with geographical location. This can be demonstrated on a local level within a particular country or throughout the European range of a species. Examples are described. Many published ecological studies of spider faunas seem to have assumed that the habitat preferences of a species is a fixed characteristic wherever they occur but evidence is presented to show that this may apply to only a few species. A number of examples are described showing how preferences change with latitude and longitude within Europe. It is proposed that most species can be categorised as stenotopic, mesotopic or eurytopic, although there is a gradual change from one group to another, with no clear boundaries. Supporting evidence for regional variation in habitat tolerance is scarce. More studies are required of individual species throughout their European distribution and detailed descriptions of their habitats in different parts of their range. Definitions of micro-, macro- and minor habitats are presented as useful tools for field studies of spider faunas. It is also recommended that future faunal surveys should use the same system of habitat classification so that the results are comparable with other studies. The most appropriate method is described by BUCHAR & RŮŽIČKA (2002) but could be made more precise by the use of scientific measuring equipment for light/shade, dryness/humidity and temperature. Finally the importance of checking the validity of some published records is stressed because misidentifications are sometimes frequent

Online Tensor Methods for Learning Latent Variable Models

We introduce an online tensor decomposition based approach for two latent variable modeling problems namely, (1) community detection, in which we learn the latent communities that the social actors in social networks belong to, and (2) topic modeling, in which we infer hidden topics of text articles. We consider decomposition of moment tensors using stochastic gradient descent. We conduct optimization of multilinear operations in SGD and avoid directly forming the tensors, to save computational and storage costs. We present optimized algorithm in two platforms. Our GPU-based implementation exploits the parallelism of SIMD architectures to allow for maximum speed-up by a careful optimization of storage and data transfer, whereas our CPU-based implementation uses efficient sparse matrix computations and is suitable for large sparse datasets. For the community detection problem, we demonstrate accuracy and computational efficiency on Facebook, Yelp and DBLP datasets, and for the topic modeling problem, we also demonstrate good performance on the New York Times dataset. We compare our results to the state-of-the-art algorithms such as the variational method, and report a gain of accuracy and a gain of several orders of magnitude in the execution time.Comment: JMLR 201

Perceptual Abstraction for Robotic Cognitive Development

We are concerned with the design of a developmental robot that learns from scratch simple models about itself and its surroundings. A particular attention is given to perceptual abstraction from high-dimensional sensors

Factors Affecting Abundance of Adult Karner Blues (\u3ci\u3eLycaeides Melissa Samuelis\u3c/i\u3e) (Lepidoptera: Lycaenidae) in Wisconsin Surveys 1987-95

At 141 pine-oak barrens in central and northwestern Wisconsin, 3,702 Karner blues (Lycaeides melissa samuelis Nabokov) were found in 81.1 hr of transect surveys during spring and 6,094 individuals in 116.6 hr during sum­mer. Adults offive other closely related lycaenids occurred with Karner blues. The percentage of Karner blue males (of sexed individuals) correlated nega- tively with advancing date within brood, exceeded 50% on peak date within brood, but showed wide variability on a given date. Karner blues occasionally occurred up to 800 m from the nearest larval host, or in tiny, isolated host stands. However, all individuals were within 3-5 km of other larger Karner blue populations. Karner blue abundance significantly increased with decreasing latitude, increasing temperature, nearness to midpoint within brood, decreasing site canopy, increasing larval host abundance, and in summer compared to spring. Long-term monitoring sites showed dramatic but relatively similar fluctuations among broods (median of 2.8-fold change among ten brood pairs) that apparently varied by individual brood rather than season or year. Extensive dense host patches and dense Karner blues were in sites rep- resenting a diversity of management histories

Parameterized Algorithms for Modular-Width

It is known that a number of natural graph problems which are FPT parameterized by treewidth become W-hard when parameterized by clique-width. It is therefore desirable to find a different structural graph parameter which is as general as possible, covers dense graphs but does not incur such a heavy algorithmic penalty. The main contribution of this paper is to consider a parameter called modular-width, defined using the well-known notion of modular decompositions. Using a combination of ILPs and dynamic programming we manage to design FPT algorithms for Coloring and Partitioning into paths (and hence Hamiltonian path and Hamiltonian cycle), which are W-hard for both clique-width and its recently introduced restriction, shrub-depth. We thus argue that modular-width occupies a sweet spot as a graph parameter, generalizing several simpler notions on dense graphs but still evading the "price of generality" paid by clique-width.Comment: to appear in IPEC 2013. arXiv admin note: text overlap with arXiv:1304.5479 by other author

Spatial Dynamics of Alternative Reproductive Strategies: The Role of Nieghbors

In territorial species, the reproductive success of a male is dependent on the quality of his territory. One important component of territory quality is spatial location. High-quality territories not only should be located in areas of high food abundance and low predation, but also should be located in areas that offer optimal amounts of social interaction. Such optima might be different for individuals according to their sex, dominance, or genotype. We studied territory quality (size, vegetation structure, and placement) in a socially monogamous, polymorphic passerine, the White-throated Sparrow (Zonotrichia albicollis), in order to determine how spatial attributes contribute to selection intensity on two genotypes. In this species, plumage (white and tan), behavior, and life-history characteristics have a genetic basis and are correlated with the presence or absence of a chromosomal inversion. Using remote sensing and Geographic Information Systems (GIS), we found that the territories of white and tan males do not differ in size or vegetation structure, suggesting that these factors are not of primary importance to males when deciding where to establish a territory. Instead, we suggest that the placement of white and tan territories depends on the number of neighbors (particularly, white male neighbors). Tan males settle in low-density, neighbor-restrictive habitats where intruder pressure from white males seeking extra-pair copulations is reduced. In contrast, white males tend to settle in high-density areas where the probability of encountering neighboring fertile females is greatest. This segregation has led to intraspecific niche partitioning in the two disassortative pair types so that each male morph can best exploit its respective reproductive strategies. These factors may, in turn, contribute to the maintenance of this unusual mating system and, ultimately, the stability of the polymorphism in this species. Similar forces may be operating in other species without distinct morphological markers; we suggest that researchers keep social factors in mind when examining habitat selection

Economic and demographic trends of municipalities in South Africa: An application of Zipf’s rule

There are vast differences among South African local municipalities, with a limited number of large municipalities (both in terms of population size and economic activity) and a seemingly disproportionate number of intermediate-sized and small municipalities. No clear systematic national approach has yet been adopted to assess the distribution of core variables at municipal level in South Africa. Zipf’s rule, which postulates a consistent regularity in the size and rank of cities, is applied to disaggregate the performance of South African local municipalities in terms of three variables (population, Gross Value Added and municipal income) within the overall national settlement pattern. The results indicate that the Zipf rank size rule distribution is applicable to municipal level population data in South Africa, but less so for Gross Value Added and municipal income. The position and relative changes of municipalities along the Zipf curve between 2001 and 2011 also provide plausible indications of potential future trajectories of the three variables classified according to the dominant settlement typology within each municipality. The results also emphasise the significant conceptual limitations when using only legally defined administrative municipal boundaries for analysis purposes without also considering economically functional boundaries.&nbsp

The Evolution of the U.S. Logistics Outsourcing Industry: An Organizational Ecology Perspective

This study intends to shed some light into the evolution of the logistics outsourcing industry in the U.S. with the help of the predictive power of organizational ecology, and to further emphasize the usefulness of organizational ecology as a tool to predict the evolution of other industries as well. This paper will hopefully be beneficial to managers in the logistics outsourcing industry as well as to scholars in the academic community. Managers in the logistics outsourcing industry could potentially utilize the findings from this study to better understand the evolution of the industry and hopefully better strategize future actions and decisions. As for the academic community, this paper hopes to contribute by taking the first initiative to apply the premises of Organizational Ecology in a dynamic and relatively new industry, the U.S. logistics outsourcing industry

Prediction of Emerging Technologies Based on Analysis of the U.S. Patent Citation Network

The network of patents connected by citations is an evolving graph, which provides a representation of the innovation process. A patent citing another implies that the cited patent reflects a piece of previously existing knowledge that the citing patent builds upon. A methodology presented here (i) identifies actual clusters of patents: i.e. technological branches, and (ii) gives predictions about the temporal changes of the structure of the clusters. A predictor, called the {citation vector}, is defined for characterizing technological development to show how a patent cited by other patents belongs to various industrial fields. The clustering technique adopted is able to detect the new emerging recombinations, and predicts emerging new technology clusters. The predictive ability of our new method is illustrated on the example of USPTO subcategory 11, Agriculture, Food, Textiles. A cluster of patents is determined based on citation data up to 1991, which shows significant overlap of the class 442 formed at the beginning of 1997. These new tools of predictive analytics could support policy decision making processes in science and technology, and help formulate recommendations for action