On the Marginal Utility of Deploying Measurement Infrastructure

The cost and complexity of deploying measurement infrastructure in the Internet for the purpose of analyzing its structure and behavior is considerable. Basic questions about the utility of increasing the number of measurements and/or measurement sites have not yet been addressed which has lead to a "more is better" approach to wide-area measurements. In this paper, we quantify the marginal utility of performing wide-area measurements in the context of Internet topology discovery. We characterize topology in terms of nodes, links, node degree distribution, and end-to-end flows using statistical and information-theoretic techniques. We classify nodes discovered on the routes between a set of 8 sources and 1277 destinations to differentiate nodes which make up the so called "backbone" from those which border the backbone and those on links between the border nodes and destination nodes. This process includes reducing nodes that advertise multiple interfaces to single IP addresses. We show that the utility of adding sources goes down significantly after 2 from the perspective of interface, node, link and node degree discovery. We show that the utility of adding destinations is constant for interfaces, nodes, links and node degree indicating that it is more important to add destinations than sources. Finally, we analyze paths through the backbone and show that shared link distributions approximate a power law indicating that a small number of backbone links in our study are very heavily utilized.

Inferring Intersection Typings that are Equivalent to Call-by-Name and Call-by-Value Evaluations

We present a procedure to infer a typing for an arbitrary λ-term M in an intersection-type system that translates into exactly the call-by-name (resp., call-by-value) evaluation of M. Our framework is the recently developed System E which augments intersection types with expansion variables. The inferred typing for M is obtained by setting up a unification problem involving both type variables and expansion variables, which we solve with a confluent rewrite system. The inference procedure is compositional in the sense that typings for different program components can be inferred in any order, and without knowledge of the definition of other program components. Using expansion variables lets us achieve a compositional inference procedure easily. Termination of the procedure is generally undecidable. The procedure terminates and returns a typing if the input M is normalizing according to call-by-name (resp., call-by-value). The inferred typing is exact in the sense that the exact call-by-name (resp., call-by-value) behaviour of M can be obtained by a (polynomial) transformation of the typing. The inferred typing is also principal in the sense that any other typing that translates the call-by-name (resp., call-by-value) evaluation of M can be obtained from the inferred typing for M using a substitution-based transformation.

Stair na Gaeilge i gContae Thiobraid Árann 1700-1901

Stair na Gaeilge i gCo. Thiobraid Árann i rith na tréimhse 1700-1901 atá á ríomhadh sa tráchtas seo. Tar éis a cúlra agus a comhthéacs a shuíomh i gCaibidil a hAon, déantar scríobhaithe an cheantair a áireamh, fara tráchtaireacht orthu, i gCaibidil a Dó. I gCaibidlí a Trí agus a Ceathair, féachtar ar thionchar na hEaglaisí Caitlicí agus Eaglais na hÉireann (i measc eaglaisí Protastúnacha eile) ar an dteangain. I gCaibidil a Cúig, faightear spléachadh ar ghnéithe éagsúla de shaíocht an chontae, ag tabhairt léargais ar tháirgí na scríobhaithe, ar leabhair a clóbhualadh sa réigiún, agus ar fhilí móra na háite, leithéidí Liam Daill Uí Ifearnáin, ag sonrú limistéir faoi leith, an t-oirdheisceart, mar shampla. Léirítear éifeacht na gcumann Gaelach agus na ndíograiseoirí iomadúla a bhain leo. Ábhar suime, leis, feidhm na Gaeilge sna cúirteanna dlí. Tugtar faisnéis i gCaibidil a Sé ar fhianaise cuairteoirí ar an Ghaeilge mar urlabhra i dTiobraid Árann. Is anseo chomh maith a deintear anailís ar Dhaonáirimh na mblianta 1861-1901, le mórchuid adhmaid á baint as ceann 1901 go háirithe. Breactar as ainmneacha sagart agus múinteoirí le Gaeilge, agus tráchtar ar aicmí suntasacha eile, na póilíní agus na saighdiúirí a raibh an teanga sin ina mbéal acu. Tugtar le chéile dá réir na snáithíní difriúla eolais ar an dúiche ar bhealach nár tharla cheana don gcontae casta fairsing seo le haghaidh na tréimhse atá idir lámha ag an saothar.

Activity patterns in design processes of IT standards

Contemporary IT standards are designed, not selected. Their design enacts a complex process that brings together a coalition of players. We examine the design of the SOAP standard to discover activity patterns in this design process. The paper reports these patterns as a precursor to developing a micro-level process theory for designing IT standards.

Uncle Tom's Cabin and the Irish National Tale

Accepted Version

Yeast screens identify the RNA polymerase II CTD and SPT5 as relevant targets of BRCA1 interaction.

BRCA1 has been implicated in numerous DNA repair pathways that maintain genome integrity, however the function responsible for its tumor suppressor activity in breast cancer remains obscure. To identify the most highly conserved of the many BRCA1 functions, we screened the evolutionarily distant eukaryote Saccharomyces cerevisiae for mutants that suppressed the G1 checkpoint arrest and lethality induced following heterologous BRCA1 expression. A genome-wide screen in the diploid deletion collection combined with a screen of ionizing radiation sensitive gene deletions identified mutants that permit growth in the presence of BRCA1. These genes delineate a metabolic mRNA pathway that temporally links transcription elongation (SPT4, SPT5, CTK1, DEF1) to nucleopore-mediated mRNA export (ASM4, MLP1, MLP2, NUP2, NUP53, NUP120, NUP133, NUP170, NUP188, POM34) and cytoplasmic mRNA decay at P-bodies (CCR4, DHH1). Strikingly, BRCA1 interacted with the phosphorylated RNA polymerase II (RNAPII) carboxy terminal domain (P-CTD), phosphorylated in the pattern specified by the CTDK-I kinase, to induce DEF1-dependent cleavage and accumulation of a RNAPII fragment containing the P-CTD. Significantly, breast cancer associated BRCT domain defects in BRCA1 that suppressed P-CTD cleavage and lethality in yeast also suppressed the physical interaction of BRCA1 with human SPT5 in breast epithelial cells, thus confirming SPT5 as a relevant target of BRCA1 interaction. Furthermore, enhanced P-CTD cleavage was observed in both yeast and human breast cells following UV-irradiation indicating a conserved eukaryotic damage response. Moreover, P-CTD cleavage in breast epithelial cells was BRCA1-dependent since damage-induced P-CTD cleavage was only observed in the mutant BRCA1 cell line HCC1937 following ectopic expression of wild type BRCA1. Finally, BRCA1, SPT5 and hyperphosphorylated RPB1 form a complex that was rapidly degraded following MMS treatment in wild type but not BRCA1 mutant breast cells. These results extend the mechanistic links between BRCA1 and transcriptional consequences in response to DNA damage and suggest an important role for RNAPII P-CTD cleavage in BRCA1-mediated cancer suppression.

SELECTED VARIATIONS BY COMPOSERS IN GERMANY AND FRANCE

The Haward of Dictionary of Music (1983), defines variation as "a technique modifying a given musical idea." From the Baroque period on, the form and the techniques of variation were developed and enriched in Germany and France. Therefore, I presented the works of composers from these two nations. Even though there was a vast number of possibilities, I wanted to be scholastically fair and interesting in making my selections by choosing well-known pieces along with lesser-known ones. Haydn's well-known Variations in F minor consist of two sets of double variations which break into an improvisation fantasy. The first movement of Beethoven Sonata in A flat major, Op. 26, is a set of five variations on the composer's original theme. The variations are positioned in the first movement instead of Sonata-Allegro form. In 1861 Brahrns composed the Variations and Fugue, Op. 24, on the theme of Handel. Brahms displays a wealth of rhythmic, harmonic and textural contrasts in the variations. Chopin's E Major Variations without opus number are written on a Swiss influenced German folksong. Faure's Theme and Variations in C sharp minor, Op. 73, includes eleven variations. The work displays the composer's subtlety, grace and reticence. 12 Variationen iiber ein eigenes Thema were written by Alban Berg as a composition study with Schonberg. The Finale of Dutilleux's Piano Sonata, titled "Chorale with Variations", is written in an impressionistic style. A rich expressiveness is well blended in a classical form. In 1742, the remarkable Aria and thirty variations known as the Goldberg Variations were composed by J. S. Bach. The thirty Variations are unified by the bass line, which forms the foundation of the Aria. The pieces discussed above were presented in three recitals. Compact disc recordings of these recitals are available in the Michelle Smith Performing Arts Library of the Clarice Smith Performing Arts Center at the University of Maryland.

The Development of Piano Variations in the Romantic Era

The purpose of this study is to illustrate the development of piano variations as a genre during the Romantic era. In order to facilitate this examination of piano variations techniques, a brief look at the types of variation procedures used by composers of previous eras will assist in understanding developments that later occurred in the Romantic period. Throughout the Baroque era, composers preferred the fured-bass, fixed-melody, and harmonic forms of variation. The crowning achievement of Baroque keyboard music, Bach's Goldberg Variations (1725), contains examples of the "constantharmonic" method in its collection of 30 variations, each of which maintains both the bass and harmonic structure of the themes. While most composers of the classical period favored the "melodic-outline" form of variation, Haydn developed hybrid variation procedure that exhibits recurrence of material rather than repetition, alternating variation (ABABA), rondo variation (ABACA), and ternary variation (ABA). Haydn, Mozart and early Beethoven variations also exhibit simpler textures than do their Baroque predecessors. The nineteenth century produced numerous compositions that display variation techniques, some based on such older, classical models as melodic-outline variation and hybrid variation, others in the style of the character variation or fiee variation. At the beginning of the nineteenth century, Beethoven and Schubert used such classical variation techmques as melodic-outline variations and hybrid variations. Beethoven's late sonatas displayed such new means of expression as variation, fugue, and dramatic recitatives. The third movement of the Sonata in E major, Op. 109 (1820) has a theme and six variations of the melodic-outline type. Johannes Brahms was particularly fond of composing variations for piano. Among the best known examples of formal-outline variations are those found in the Variations and Fugue on a Theme of Handel, Op. 24 (1861). Character variations, in which styles are characterized by the retention and variability of particular elements, also flourished during the Romantic period. Cesar Franck's Variations Symphoniques (1885) are, perhaps, among the most important examples of free variations. This composition is a one-movement work consisting of three sections, Introduction, Variations, and Finale (all movements played "attaca"). This work combines two independent classical formal structures, the concerto and the variation.

THE PIANO FANTASY FROM BACH TO DANIELPOUR

The Fantasy, as the term suggests, is a genre that composers have found congenial for exploring innovative and imaginative processes. Works in this genre are numerous in the solo piano literature, and extend even to works for piano and orchestra and to chamber music with piano. I was curious to explore how a specific genre of music maintained similar characteristics but evolved over time. A fantasy is primed to be inventive and I wanted to see how composers from different eras and backgrounds would handle their material in this genre. I have learned that composers worked through formal developments while making innovations within this genre. The heart of my dissertation is presented through the recording project. Because ofthe abundance ofpiano fantasies, many works had to be excluded from this project for time's sake. On two compact discs, I have recorded approximately two hours of solo piano music. I have included some shorter fantasies to magnify significant developments from era to era, country to country, and composer to composer. The first disc has recordings of eighteenth and nineteenth-century fantasies: Chromatic Fantasy and Fugue, BWV 903 by J.S. Bach (1685-1750); Fantasia inC major, H. XVII, 4 by Franz Joseph Haydn (1732-1809); Fantasy inc minor, K. 475 by Wolfgang Amadeus Mozart (1756- 1791); Fantasia inf-sharp minor, Op. 28 by Felix Mendelssohn (1809-1847); and Polonaise-Fantaisie in A-flat major, Op. 61 by Frederic Chopin (1810-1849). On the second disc I have included mid-19th, 20th and 2151-century piano fantasies: Fantasy and Fugue on the Theme B-A-C-H by Franz Liszt (1811-1886); Fantasia Baetica by Manuel de Falla (1876-1946); Three Fantasies by William Bergsma (1921-1994); Fantasy, Aria and Fugue by Frederic Goossen (1927-2011); and Piano Fantasy ("Wenn ich einmal sol! scheiden") by Richard Danielpour (b. 1956). The accompanying document includes program notes for each of the pieces recorded. They were recorded on a Steinway "D" in Dekelboum Concert Hall at the University of Maryland by Antonino D'Urzo ofOpusrite Productions. This document is available in the Digital Repository at the University of Maryland and the CO's are available through the Library System at the University of Maryland.

Determinación del potencial alelopático de cultivares de arroz (Oryza sativa L.) más frecuentemente empleados en la Mesopotamia

El arroz (Oryza sativa L.) es una especie cultivada en todo el mundo y las malezas constituyen uno de los principales factores que afectan su producción. El conocimiento del potencial alelopático de los diferentes cultivares regionales resulta fundamental en términos de posibles estrategias para el control de las mismas. Se evaluó el potencial alelopático en cultivares de arroz utilizados en la Mesopotamia argentina frente a Echinochloa crus galli L. A través de boiensayos RST (Relay Seeding Technique) se determinó que los cultivares El Paso 144 (EP) y Bluebonnet 50 (BB) presentaron mayor bioactividad que Cambá, Yeruá, Irga 147 y Supremo 13. Los posibles aleloquímicos relacionados al potencial inhibitorio fueron evaluados en las raíces de los dos cultivares fuertemente activos (EP) y (BB) y el menos bioactivo (Supremo 13). Mediante técnicas cromatográficas (CG y CLAR) y espectroscópicas (RMN 1H y 13C y EM) se determinó la presencia de hidrocarburos, aldehídos, cetonas, ácidos carboxílicos y sus ésteres metílicos en los extractos no polares. Los cultivares alelopáticos (BB y EP) presentaron mayor proporción de compuestos oxigenados que el no alelopático (Supremo 13). Se informa por primera vez la cetona 6,10,14-trimetil-2-pentadecanona en un cultivar de arroz alelopático. Todos los cultivares de arroz produjeron los ácidos cafeico, vanilico, siríngico, ferúlico y p-cumárico, siendo la concentración de este último mayor en los alelopáticos. En los extractos metanólicos de los cultivares alelopáticos se determinó la presencia del 3-O-? -D-glucopiranósido de sitosterol y de las momilactonas A y B que fueron caracterizadas por técnicas espectroscópicas. Estos resultados son los primeros en relació n al cultivo de arroz en Argentina y tienen utilidad potencial en el control de malezas, en términos del manejo sustentable de los agroecosistemas arroceros.

Thomas Koinzer: Auf der Suche nach der demokratischen Schule, Amerikafahrer, Kulturtransfer und Schulreform in der Bildungsreformära der Bundesrepublik Deutschland, Bad Heilbrunn: Klinkhardt 2011 [Rezension]

Rezension von: Thomas Koinzer: Auf der Suche nach der demokratischen Schule, Amerikafahrer, Kulturtransfer und Schulreform in der Bildungsreformära der Bundesrepublik Deutschland, Bad Heilbrunn: Klinkhardt 2011 (279 S.; ISBN 978-3-7815-1811-7; 32,00 EUR)