Static locality analysis for cache management

Most memory references in numerical codes correspond to array references whose indices are affine functions of surrounding loop indices. These array references follow a regular predictable memory pattern that can be analysed at compile time. This analysis can provide valuable information like the locality exhibited by the program, which can be used to implement more intelligent caching strategy. In this paper we propose a static locality analysis oriented to the management of data caches. We show that previous proposals on locality analysis are not appropriate when the proposals have a high conflict miss ratio. This paper examines those proposals by introducing a compile-time interference analysis that significantly improve the performance of them. We first show how this analysis can be used to characterize the dynamic locality properties of numerical codes. This evaluation show for instance that a large percentage of references exhibit any type of locality. This motivates the use of a dual data cache, which has a module specialized to exploit temporal locality, and a selective cache respectively. Then, the performance provided by these two cache organizations is evaluated. In both organizations, the static locality analysis is responsible for tagging each memory instruction accordingly to the particular type(s) of locality that it exhibits.Peer ReviewedPostprint (published version

Diálogos metaficcionales e intermediales (II) entre Agustín Fernández Mallo y Enrique Vila-Matas

The essay, dedicated to Darío Villanueva, one of the most important Spanish specialists in literary theory and comparative literature of the 20th century, explores in the first part his contribution to the research on metaliterature and metafiction in the Spanish contemporary novel of the decades of 1980-1990. His works establish the relationships of these concepts with postmodernity theories and with umberto Eco’s thesis in Il nome della rosa, Postille and other relevant essays of the Italian author. In the second part of the text, the aim is to apply these concepts of literary self-consciousness and reflexivity in the novel as a story-telling device in the work of one of the most relevant Spanish young writers of the 21st Century, Agustín Fernandez Mallo’s Nocilla Lab. In this sense, we will focus the ending sequence, written (and designed) in form of a comic book or graphic novel, in which the young author puts himself beside the more recognized Enrique Vila-Matas, as an allegoric and fictional reflection of Pierre Bourdieu’s theories about the literary field.The essay, dedicated to Darío Villanueva, one of the most important Spanish specialists in literary theory and comparative literature of the 20th century, explores in the first part his contribution to the research on metaliterature and metafiction in the Spanish contemporary novel of the decades of 1980-1990. His works establish the relationships of these concepts with postmodernity theories and with umberto Eco’s thesis in Il nome della rosa, Postille and other relevant essays of the Italian author. In the second part of the text, the aim is to apply these concepts of literary self-consciousness and reflexivity in the novel as a story-telling device in the work of one of the most relevant Spanish young writers of the 21st Century, Agustín Fernandez Mallo’s Nocilla Lab. In this sense, we will focus the ending sequence, written (and designed) in form of a comic book or graphic novel, in which the young author puts himself beside the more recognized Enrique Vila-Matas, as an allegoric and fictional reflection of Pierre Bourdieu’s theories about the literary field

Temporal characterization of the requests to Wikipedia

This paper presents an empirical study about the temporal patterns characterizing the requests submitted by users to Wikipedia. The study is based on the analysis of the log lines registered by the Wikimedia Foundation Squid servers after having sent the appropriate content in response to users' requests. The analysis has been conducted regarding the ten most visited editions of Wikipedia and has involved more than 14,000 million log lines corresponding to the traffic of the entire year 2009. The conducted methodology has mainly consisted in the parsing and filtering of users' requests according to the study directives. As a result, relevant information fields have been finally stored in a database for persistence and further characterization. In this way, we, first, assessed, whether the traffic to Wikipedia could serve as a reliable estimator of the overall traffic to all the Wikimedia Foundation projects. Our subsequent analysis of the temporal evolutions corresponding to the different types of requests to Wikipedia revealed interesting differences and similarities among them that can be related to the users' attention to the Encyclopedia. In addition, we have performed separated characterizations of each Wikipedia edition to compare their respective evolutions over time

A quantitative examination of the impact of featured articles in Wikipedia

This paper presents a quantitative examination of the impact of the presentation of featured articles as quality content in the main page of several Wikipedia editions. Moreover, the paper also presents the analysis performed to determine the number of visits received by the articles promoted to the featured status. We have analyzed the visits not only in the month when articles awarded the promotion or were included in the main page, but also in the previous and following ones. The main aim for this is to assess the attention attracted by the featured content and the different dynamics exhibited by each community of users in respect to the promotion process. The main results of this paper are twofold: it shows how to extract relevant information related to the use of Wikipedia, which is an emerging research topic, and it analyzes whether the featured articles mechanism achieve to attract more attention

Mechanism of Alkyl Migration in Diorganomagnesium 2,6-Bis(imino)pyridine Complexes: Formation of Grignard-Type Complexes with Square-Planar Mg(II) Centers

Dialkylmagnesium compounds [MgR2L2] (R = n-Bu, L = none or R = Bn, L = THF) react with 2,6-bis(imino)pyridines (BIP) to afford different types of Mg(II) alkyl complexes, depending on the nature of R. For R = n-Bu, thermally stable products resulting from selective alkyl transfer to the pyridine nitrogen (N1) atom are obtained. However, NMR studies showed that the reaction of [Mg(Bn)2THF2] with iPrBIP at −65 °C leads to a thermally unstable product arising from benzyl migration to position C2 in the pyridine ring. Above +5 °C, this compound rearranges, cleanly yielding a mixture of two isomeric complexes, in which the benzyl group has migrated to positions C3 or C4 of the central ring, respectively. Similar isomeric mixtures were obtained when [Mg(Bn)2THF2] was reacted with iPrBIP or MesBIP at room temperature. Such mixtures are thermally stable below 80 °C, but at this temperature, the 3-benzyl isomer converts into the thermodynamically favored 4-benzyl product, albeit not quantitatively. An alternate route was devised for the selective syntheses of the latter type of compounds. The X-ray diffraction structure of one of them provided an unusual example of a square-planar alkylmagnesium(II) center.Ministerio de Economía e Innovación CTQ2015-68978-

La introducción de las teorías de E. Acharius (1757-1819) en la liquenología española

El sistema taxonómico trazado por E. Acharius fue introducido en España por M.Lagasca y S.R. Clemente. La recepción del "Methodus..." (1803) se efectuó con anterioridad Noviembre de 1806, a tenor de la correspondencia mantenida entre M. Lagasca y P. Lallave.La "Sinopsis..." (1814) fue utilizada con anterioridad a Junio de 1817, este texto fue distribuido por el algólogo sueco C.A. Agardh entre sus corresponsales A. Cabrera y F. Haenseler.E. Acharius recibió líquenes españoles, herborizados por M. Lagasca, L. Dufour y P.K.A. Schousboe, y ejemplares americanos, de A.J. Cavanilles y J. Dombey, con anterioridad a 1807. Los materiales del "Ensayo..." (1807) de S.R. Clemente fueron recibidos por E.Acharius entre 1809 y 1814.Se aportan los datos disponibles sobre la localización de los materiales citados por estos autores en sus trabajos liquenológicos.The system of lichen taxonomy outlined by E. Acharius was introduced in Spain by M. Lagasca and S.R. Clemente. As we now, from contemporary correspondence between M. Lagasca and P. Lallave, the "Methodus..." was received before November 1806. The Acharius "Synopsis..." (1814) was utilized before June 1817; the text was distribuited by the swedish algologist C.A. Agardh among his correspondents A. Cabrera and F. Haenseler.Before 1807, spanish lichens were sent to E. Acharius by M. Lagasca, L. Dufour and P.K.A. Schousboe, and also, american material of A.J. Cavanilles and J. Dombey. E. Acharius received material from S.R. Clemente's work ("Ensayo..."; 1807) between 1809 and 1814.Information on location of herbarium material, cited by these mentioned autors is revised

Asymmetric Hydrogenation of 1-alkyl and 1-aryl vinyl benzoates: a broad scope procedure for the highly enantioselective synthesis of 1-substituted ethyl benzoates

The enantioselective hydrogenation of enol esters of formula CH2=C(OBz)R with rhodium catalysts based on phosphine-phosphite ligands (P-OP) has been studied. The reaction has a broad scope and it is suitable for the preparation of products possessing a wide variety of R substituents. For the cases where R is a primary alkyl high catalyst activity (S/C = 500) and enantioselectivities (95-99 % ee) were obtained with a catalyst characterized by an ethane backbone and a PPh2 fragment. In contrast, for R = tBu a catalyst possessing a benzene backbone provided the best results (97 % ee). Derivatives with a cycloalkyl R substituent were particularly difficult substrates for this reaction. A broader catalyst screening was required for these substrates, which identified a catalyst possessing a P(m-xylyl)2 fragment as the most appropriate one, affording enantioselectivities between 90 and 95 % ee. Outstanding enantioselectivities (99 % ee) and high catalyst activity (S/C = 500-1000) were also obtained in the case of substrates bearing a Ph or a fluoroaryl R substituent. In addition, the system is also appropriate for the preparation of other synthetically useful esters as those for R = benzyl, 2-phenylethyl or Nphthalimido alkyl chains. Likewise, the hydrogenation of divinyl dibenzoates proceeded with very high diastero- and enantioselectivity, generating rather low amounts of the meso isomer (3-6 %). On the other hand, substrates with Br- and MeO- substituents at the phenyl benzoate ring, suitable for further functionalization, have also been examined. The results obtained indicate no detrimental effect of these substituents in the hydrogenation. Alternatively, the methodology has been applied to the highly enantioselective synthesis of deuterium isotopomers of 1-octyl benzoate bearing CDH2, CD2H or CD3 fragments. Finally, as a practical advantage of the present system, it has been observed that the high performance of the catalysts is retained in high concentrated solutions or even in the neat substrate, then minimizing both the amount of solvent added and the volume of the reactionJunta de Andalucía 2009/FQM-4832CSIC 201480E03 1Ministerio de Ciencia e Innovación CTQ2010- 14796/BQ

The unique fibrilar to platy nanoand microstructure of twinned rotaliid foraminiferal shell calcite

Open Access funding enabled and organized by Projekt DEALGerman Research Council (Grant No. GR9/1234 SCHM/930/11-2)

Oxygen-Induced Dimerization of Alkyl-Manganese(II) 2,6-Bisiminopyridine Complexes: Selective Synthesis of a New Ditopic NNN-Pincer Ligand

The outcome of the reaction of manganese(II) dialkyls with 2,6-bisiminopyridine (BIP) ligands is dramatically altered by the presence of very small amounts of oxygen (< 0.5 mol %), leading to binuclear species. These arise from the dimerization of the initial product, a Mn(II) 4-alkyl-2,6-bisiminodihydropyridinate alkyl complex. Cleavage of the binuclear Mn products with methanol affords the free dimeric bases, which can be regarded as a special type of ditopic NNN pincer ligand with an unusual tricyclic framework. The coordinative ability of the new ligands has been probed with the syntheses of Zn and Pd organometallic derivativesMinisterio de Economía e Innovación TQ2015- 68978-