The Working Paper Series seeks to disseminate original research in economics and fi nance. All papers have been anonymously refereed. By publishing these papers, the Banco de España aims to contribute to economic analysis and, in particular, to knowledge of the Spanish economy and its international environment. The opinions and analyses in the Working Paper Series are the responsibility of the authors and, therefore, do not necessarily coincide with those of the Banco de España or the Eurosystem. The Banco de España disseminates its main reports and most of its publications via the Internet at the following website: http://www.bde.es. Reproduction for educational and non-commercial purposes is permitted provided that the source is acknowledged.

We study determinants of sovereign portfolios of Spanish banks over a long time-span, starting in 2008. Our findings challenge the view that banks engaged in moral hazard strategies to exploit the regulatory treatment of sovereign exposures. In particular, we show that being a weakly capitalized bank is not related to higher holdings of domestic sovereign debt. While a strong link is present between central bank liquidity support and sovereign holdings, opportunistic strategies or reach-for-yield behavior appear to be limited to the nondomestic sovereign portfolio of well-capitalized banks, which might have taken advantage of their higher risk-bearing capacity to gain exposure (via central bank liquidity) to the set of riskier sovereign bonds. Furthermore, we document that financial fragmentation in EMU markets has played a key role in reshaping sovereign portfolios of banks. Overall, our results have important implications for the ongoing discussion on the optimal design of the riskweighted capital framework of banks.

The Working Paper Series seeks to disseminate original research in economics and fi nance. All papers have been anonymously refereed. By publishing these papers, the Banco de España aims to contribute to economic analysis and, in particular, to knowledge of the Spanish economy and its international environment. The opinions and analyses in the Working Paper Series are the responsibility of the authors and, therefore, do not necessarily coincide with those of the Banco de España or the Eurosystem. The Banco de España disseminates its main reports and most of its publications via the Internet at the following website: http://www.bde.es. Reproduction for educational and non-commercial purposes is permitted provided that the source is acknowledged.

No abstract

Resumen. Diversos aspectos de la historia natural de especies del grupo Leptodactylus marmoratus son escasamente conocidos y la poca información existente aborda principalmente los de la biología reproductiva. El objetivo de este trabajo es aportar información acerca de la dieta y del parasitismo de poblaciones de Leptodactylus diptyx del nordeste argentino. Para el estudio trófico, se analizó el contenido estomacal e intestinal de 22 individuos adultos, mientras que para el estudio parasitario, se examinó el tubo digestivo de 40 individuos. Se registró un total de 91 presas, clasificadas en 17 categorías, entre los cuales los himenópteros formícidos fueron los más numerosos (45%) y frecuentes (55%). Otras presas importantes fueron colémbolos, coleópteros y arañas. Los valores de diversidad de presas (índice de Shannon) y amplitud del nicho (índice de Levins) fueron 2.06 y 4.29, respectivamente. El 57.5% de los individuos examinados resultó positivo al examen de endoparásitos, entre los que se incluyen nematodos y acantocefalos. Leptodactylus diptyx representa un nuevo hospedador para los nematodos Cosmocerca sp. y Aplectana sp.

Abstract:We present a new record of Amphisbaena trachura (Squamata: Amphisbaenidae) for the northeast of Corrientes province, Argentina. Seven specimens (five females and two males) were identified using morphological and meristic characters. The specimens were found under Eucalyptus sp. logs on

BackgroundMany HIV databases and applications focus on a limited domain of HIV knowledge. Since even a “simple” organism like HIV represents a very complex system with many interacting elements, the fractured structure of existing databases and applications likely limits our ability to investigate and understand HIV. To facilitate research, therefore, we have built HIVToolbox, which integrates much of the knowledge about HIV proteins and presents the data in an interactive web application. HIVToolbox allows quick and convenient hypotheses generation, experiment interpretation, and potential new drug structure creation.MethodsHIVToolbox was built as a standard three-tier J2EE web application, consisting of 1) an underlying relational MySQL database, 2) a set of standard Java data access objects that pull data from the database, and 3) a set of dynamic web pages the user interacts with. HIV-1 data from external sources such as the Protein Data Bank, NCBI, Los Alamos, etc. was collected, curated, and stored in the HIVToolbox database. Additional data, such as homology and position statistics matrices, was generated from existing data. Since version 1, drug binding site and drug resistant mutation data has also been added.ResultsHIVToolbox was used to create several new hypotheses about HIV-1 integrase, including predicting the location of a CK2 phosphorylation site, which was later confirmed by experiment. A new version of HIVToolbox support display of the 3D locations of drug resistant mutations on surface plots of HIV proteins and the drug binding sites for structures of complexes of HIV proteins with drugs.ConclusionHIVToolbox is an open-access web application that allows virologists and structural biologists to access detailed information about HIV-1 proteins, such as sequence, structure, functional sites and relationships, homology, drug binding sites, and drug resistant mutations, and to immediately see the relationships between any or all of them. Weblink: [http://hivtoolbox.bio-toolkit.com]

This paper analyses the ability of banks to use voluntary and regulatory capital buffers, taking advantage of the experience of the COVID-19 pandemic. In the first place, we find that the usability of macroprudential buffers is not hampered in Spain by other parallel banks’ requirements. Additionally, we find that the existing voluntary buffers over capital requirements at the beginning of the pandemic have had significant effects on the financial markets, affecting the evolution of European bank stock prices, as well as the holdings of bank shares by investment funds. Lastly, we find no significant aggregate effect of voluntary capital buffers on the provision of financing to non-financial companies in Spain. However, we do identify negative effects in the supply of credit from banks with lower voluntary buffers to companies with which they had more recent relationships. Likewise, if the analysis is carried out exclusively on credit operations without public guarantees, we observe that those banks with lower voluntary capital buffers reduced credit more.