10,750 research outputs found
Addenda and omissions to the catalogue and checklist of the Cerambycidae and Disteniidae (Coleoptera) of the Western hemisphere
The Catalogue (Monne, 1993-1994) and Checklist (Monne and Giesbert, 1995) of the Cerambycidae and Disteniidae of the Western Hemisphere represents a necessary, and valuable tool since recompilation of Blackwelder (1946) was made. Species with references (omissions), and without them (new records) are given for some countries
The genus Erlandia Aurivillius, 1904 (Coleoptera: Cerambycidae) in Argentina, with the description of a new species
The genus Erlandia (Cerambycinae: Erlandiini) was described by Aurivillius in 1904, containing a single species, Erlandia inopinata, distributed in Bolivia, Argentina, and Paraguay. Anew species, E. megacephala, from Argentina is described, and illustrated here. A key and distribution map of both species are provided, with a generic diagnosis using characters of both species
New species, combinations, synonymies, and records of Clytini (Coleoptera: Cerambycidae)
Megacyllene (Megacyllene) cryptofrasciata n. sp. from Argentina is described and illustrated. M. quinquefasciata (Melzer, 1931), and Megacyllene rotundicollis Zajciw, 1963 are transferred from the subgenus Megacyllene Casey 1912 to Sierracyllene Tippmann, 1960. Megacyllene (SierracylZene) tafivallensis n. sp. is described from northwestern Argentina. Dexithea spixii (Laporte & Gory, 1836), and Plagionotus latreillei (Laporte & Gory, 1836) are transferred to Megacyllene (sensu stricto), excluding Dexithea, and Plagionotus from the South American fauna of Clytini. Neoclytus famelicus (Burmeister, 1865) is synonymized with N. ypsilon Chevrolat, 1861. Additional new records of Clytini from Argentina, Paraguay, and Ecuador are also presented here. A key for subgenera and species of Megacyllene is included, with distribution maps for Argentina and nearby countries
Expressing the tacit knowledge of a digital library system as linked data
Library organizations have enthusiastically undertaken semantic web initiatives and in particular the data publishing as linked data. Nevertheless, different surveys report the experimental nature of initiatives and the consumer difficulty in re-using data. These barriers are a hindrance for using linked datasets, as an infrastructure that enhances the library and related information services. This paper presents an approach for encoding, as a Linked Vocabulary, the "tacit" knowledge of the information system that manages the data source. The objective is the improvement of the interpretation process of the linked data meaning of published datasets. We analyzed a digital library system, as a case study, for prototyping the "semantic data management" method, where data and its knowledge are natively managed, taking into account the linked data pillars. The ultimate objective of the semantic data management is to curate the correct consumers' interpretation of data, and to facilitate the proper re-use. The prototype defines the ontological entities representing the knowledge, of the digital library system, that is not stored in the data source, nor in the existing ontologies related to the system's semantics. Thus we present the local ontology and its matching with existing ontologies, Preservation Metadata Implementation Strategies (PREMIS) and Metadata Objects Description Schema (MODS), and we discuss linked data triples prototyped from the legacy relational database, by using the local ontology. We show how the semantic data management, can deal with the inconsistency of system data, and we conclude that a specific change in the system developer mindset, it is necessary for extracting and "codifying" the tacit knowledge, which is necessary to improve the data interpretation process
Addressing the tacit knowledge of a digital library system
Recent surveys, about the Linked Data initiatives in library organizations, report the experimental nature of related projects and the difficulty in re-using data to provide improvements of library services. This paper presents an approach for managing data and its "tacit" organizational knowledge, as the originating data context, improving the interpretation of data meaning. By analyzing a Digital Libray system, we prototyped a method for turning data management into a "semantic data management", where local system knowledge is managed as a data, and natively foreseen as a Linked Data. Semantic data management aims to curates the correct consumers' understanding of Linked Datasets, driving to a proper re-use
Testing for non-causality by using the Autoregressive Metric
A new non-causality test based on the notion of distance between ARMA models is proposed in this paper. The advantage of this test is that it can be used in possible integrated and cointegrated systems, without pre-testing for unit roots and cointegration. The Monte Carlo experiments indicate that the proposed method performs reasonably well in nite samples. The empirical relevance of the test is illustrated via two applications.AR metric, Bootstrap test, Granger non-causality, VAR
A Panel Cointegration study of the long-run relationship between Savings and Investments in the OECD economies, 1970-2007
In this paper we test for the existence of a long-run savings-investments relationship in 18 OECD economies over the period 1970-2007. Although individual modelling provides only very weak support to the hypothesis of a link between savings and investments, this cannot be ruled out as individual time series tests may have low power. We thus construct a new bootstrap test for panel cointegration robust to short- and long-run dependence across units. Thid test provides evidence of a long-run savings-investments relationship in about half of the OECD economies examined. The elasticities are however often smaller than 1, the value expected under no capital movements.Savings, Investments, Feldstein-Horioka puzzle, OECD, Panel Cointegration, Stationary Bootstrap.
Testing for breaks in cointegrated panels
Stability tests for cointegrating coefficients are known to have very low power with small to medium sample sizes. In this paper we propose to solve this problem by extending the tests to dependent cointegrated panels through the stationary bootstrap. Simulation evidence shows that the proposed panel tests improve considerably on asymptotic tests applied to individual series. As an empirical illustration we examined investment and saving for a panel of 14 European countries over the 1960-2002 period. While the individual stability tests, contrary to expectations and graphical evidence, in almost all cases do not reject the null of stability, the bootstrap panel tests lead to the more plausible conclusion that the long-run relationship between these two variables is likely to have undergone a break.Panel cointegration; stationary bootstrap; parameter stability tests
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