Runaway repeats force expansion of the Phytophthora infestans genome

Sequencing of the potato late blight pathogen Phytophthora infestans provides insight into the structure and evolution of its genome

THE HIGH-VOLUME RETURN PREMIUM: EVIDENCE FROM THE FINNISH STOCK MARKET

This thesis tests whether the high-volume return premium is present in the Finnish stock market during a time horizon from April 1994 to May 2016. It provides a theoretical insight into the importance of trading volume, and how it may be used to predict future price movements of stocks. The thesis is thus testing whether the weak-form of the efficient market hypothesis holds in the Finnish stock market. Stocks are classified as high (low) volume based on their previous 49 days trading volume, and placed in long (short) portfolios, which are then held for up to 100 days without rebalancing. Stocks are then classified as small, medium, and large sized firms based on end year market capitalization. The results show weak evidence to support the existence of the high-volume return premium based on daily data. Weekly data does show significant returns for medium and large sized firms. This is not due to return autocorrelations or extreme values. However, it does turn out that the returns are purely driven by shifts in systematic risk.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Parallel ocean flow computations on a regular and on an irregular grid

Ocean flow problems can be discretized and solved on a regular grid, by taking l and points into account in the computations, or on an irregular grid. In the latter approach, the number of unknowns is less than for the regular grid. The data structures are completely different for the two approaches. As a consequence, different nummerical techniques may be required. In this paper we study different preconditioners, based on the EBE-preconditioner that was initially proposed by Hughes et al. We also show how the algorithms can be parallelized and we give results ontained on a cluster of workstations

The parallel computation of the smallest eigenpair of an acoustic problem with damping

Acoustic problems with damping may give rise to large quadratic eigenproblems. Efficient and parallelizable algorithms are required for solving these problems. The recently proposed Jacobi-Davidson method is well suited for parallel computing: no matrix decomposition and no back or forward substitutions are needed. This paper describes the parallel solution of the smallest eigenpair of a realistic and very large quadratic eigenproblem with the Jacobi-Davidson method

Gene amplification of the Hps locus in Glycine max

BACKGROUND: Hydrophobic protein from soybean (HPS) is an 8 kD cysteine-rich polypeptide that causes asthma in persons allergic to soybean dust. HPS is synthesized in the pod endocarp and deposited on the seed surface during development. Past evidence suggests that the protein may mediate the adherence or dehiscence of endocarp tissues during maturation and affect the lustre, or glossiness of the seed surface. RESULTS: A comparison of soybean germplasm by genomic DNA blot hybridization shows that the copy number and structure of the Hps locus is polymorphic among soybean cultivars and related species. Changes in Hps gene copy number were also detected by comparative genomic DNA hybridization using cDNA microarrays. The Hps copy number polymorphisms co-segregated with seed lustre phenotype and HPS surface protein in a cross between dull- and shiny-seeded soybeans. In soybean cultivar Harosoy 63, a minimum of 27 ± 5 copies of the Hps gene were estimated to be present in each haploid genome. The isolation and analysis of genomic clones indicates that the core Hps locus is comprised of a tandem array of reiterated units, with each 8.6 kb unit containing a single HPS open reading frame. CONCLUSION: This study shows that polymorphisms at the Hps locus arise from changes in the gene copy number via gene amplification. We present a model whereby Hps copy number modulates protein expression levels and seed lustre, and we suggest that gene amplification may result from selection pressures imposed on crop plants

Wastewater management in Zimbabwe

Wastewater management in Zimbabw

Kindersterfte door ongevallen: ontwikkeling in de afgelopen 40 jaar

Van alle landen in Europa heeft Nederland het op een na laagste sterftecijfer ten gevolge van nietnatuurlijkeoorzaken, waaronder ongevallen, bij kinderen. In dit artikel beschrijven wij de ontwikkeling van de kindersterfte door ongevallen in Nederland in de periode 1969-2011 en geven we mogelijke verklaringen voor deze ontwikkeling. Daartoe zijn de gegevens geanalyseerd over de primaire doodsoorzaken, die sinds 1969 zijn opgenomen in de doodsoorzakenstatistiek van het Centraal Bureau voor de Statistiek (CBS), en beschikbaar zijn via Statline. De sterfte door ongevallen bij kinderen in de leeftijd 0-19 jaar is sinds 1969 sterk afgenomen, met name door de daling in het aantal vervoersongevallen van 20/100.000 in 1973 naar 1,9/100.000 in 2011. Diverse verkeersmaatregelen die vanaf 1973 door de overheid zijn getroffen, lijken te hebben geresulteerd in de enorme afname van het aantal ongevallen in het wegverkeer. Wat betreft de overige ongevallen is de daling van de accidentele verdrinking in de periode 1996-2011 opmerkelijk: van 0,9/100.000 in 1996 naar 0,1/100.000 in 2011. Bij deze afname spelen waarschijnlijk sociaal-culturele factoren en effectieve preventieve maatregelen een rol. Jongens blijken vaker het slachtoffer van ongevallen dan meisjes. De sterfte door ongevallen bij kinderen kan verder afnemen door bestaande preventievemaatregelen te borgen en hiervoor blijvend aandacht te vragen via de professionals in dejeugdgezondheidszorg en beleidsmakers. Verder kan systematische analyse van de aard enomstandigheden van elk sterfgeval aanwijzingen geven voor nieuwe preventiemogelijkhede

Quadratic eigenproblems are no problem

High-dimensional eigenproblems often arise in the solution of scientific problems involving stability or wave modeling. In this article we present results for a quadratic eigenproblem that we encountered in solving an acoustics problem, specifically in modeling the propagation of waves in a room in which one wall was constructed of sound-absorbing material. Efficient algorithms are known for the standard linear eigenproblem, Ax = x where A is a real or complex-valued square matrix of order n. Generalized eigenproblems of the form Ax = Bx, which occur in nite element formulations, are usually reduced to the standard problem, in a form such as B Ax = x. The reduction requires an expensive inversion operation for one of the matrices involved. Higher-order polynomial eigenproblems are also usually transformed into standard eigenproblems. We discuss here the second-degree (i.e., quadratic) eigenproblem 2C2 + C1 + C0 x = 0 in which the matrices Ci are square matrices