Compression of Weighted Graphs

We propose to compress weighted graphs (networks), motivated by the observation that large networks of social, biological, or other relations can be complex to handle and visualize. In the process also known as graph simplication, nodes and (unweighted) edges are grouped to supernodes and superedges, respectively, to obtain a smaller graph. We propose models and algorithms for weighted graphs. The interpretation (i.e. decompression) of a compressed, weighted graph is that a pair of original nodes is connected by an edge if their supernodes are connected by one, and that the weight of an edge is approximated to be the weight of the superedge. The compression problem now consists of choosing supernodes, superedges, and superedge weights so that the approximation error is minimized while the amount of compression is maximized. In this paper, we formulate this task as the 'simple weighted graph compression problem'. We then propose a much wider class of tasks under the name of 'generalized weighted graph compression problem'. The generalized task extends the optimization to preserve longer-range connectivities between nodes, not just individual edge weights. We study the properties of these problems and propose a range of algorithms to solve them, with dierent balances between complexity and quality of the result. We evaluate the problems and algorithms experimentally on real networks. The results indicate that weighted graphs can be compressed efficiently with relatively little compression error.Peer reviewe

Document retrieval on repetitive string collections

Most of the fastest-growing string collections today are repetitive, that is, most of the constituent documents are similar to many others. As these collections keep growing, a key approach to handling them is to exploit their repetitiveness, which can reduce their space usage by orders of magnitude. We study the problem of indexing repetitive string collections in order to perform efficient document retrieval operations on them. Document retrieval problems are routinely solved by search engines on large natural language collections, but the techniques are less developed on generic string collections. The case of repetitive string collections is even less understood, and there are very few existing solutions. We develop two novel ideas, interleaved LCPs and precomputed document lists, that yield highly compressed indexes solving the problem of document listing (find all the documents where a string appears), top-k document retrieval (find the k documents where a string appears most often), and document counting (count the number of documents where a string appears). We also show that a classical data structure supporting the latter query becomes highly compressible on repetitive data. Finally, we show how the tools we developed can be combined to solve ranked conjunctive and disjunctive multi-term queries under the simple model of relevance. We thoroughly evaluate the resulting techniques in various real-life repetitiveness scenarios, and recommend the best choices for each case.Peer reviewe

Prevalence and characteristics of psychiatric morbidity treated in specialized health care in a nationwide cohort of people with newly diagnosed Alzheimer's disease

Objective: Psychiatric disorders have been implied as both risk factors and prodromal symptoms of Alzheimer's disease (AD). A better understanding of the history of psychiatric morbidity in people with AD may aid with understanding this relationship and highlight challenges in diagnosing AD in people with concomitant psychiatric disorders.Methods: Medication use and Alzheimer's disease (MEDALZ) study is a nationwide register-based cohort of people (n = 70,718) who received a clinically verified AD diagnosis in Finland in 2005-2011 and were community-dwelling at the time of diagnosis. The study population was divided into four groups based on psychiatric morbidity treated in specialized health care. We characterized the groups using data of psychiatric and somatic illnesses, psychotropic drug use, and socioeconomic factors and investigated factors associated with prodromal AD.Results: Altogether, 4.3% of cohort members had a psychiatric diagnosis at least five years before AD diagnosis, 3.1% had a psychiatric diagnosis only up to five years before AD diagnosis, and 1.1% had a psychiatric diagnosis both less and more than 5 years before AD. Belonging to the Prodromal group (psychiatric diagnosis within 5 years before AD diagnosis) was most strongly associated with substance abuse (RR 65.06, 95%CI 55.54-76.22). Other associated factors with the Prodromal group were female gender, use of psychotropics, stroke, and asthma/COPD.Conclusion: Substance abuse and psychotropic drug use are common five years before AD diagnosis. These can be potential markers of possible prodromal symptoms of AD and should be acknowledged in clinical work.</p

The immediate impact of the Brexit referendum on Nordic stock markets

This thesis investigates immediate impact of the Brexit referendum on Nordic stock market returns. The aim of this paper is to find how similar the stock market reaction in Nordic countries was that of the UK. The Brexit referendum held on June 23, 2016 was about British voting whether the UK would stay or leave the European Union. The decision was unexpectedly leave. The previous literature has shown a relationship between the outcomes of uncertain political events and stock markets. This is also the case for the Brexit referendum. This paper conducts event-study to measure the effects of the referendum result on market returns. The event-study is conducted by using constant mean-return model for estimating abnormal returns and cumulative abnormal returns from logarithmic returns. Abnormal returns for event day and cumulative abnormal returns for 3, 6 and 11 days and swiftness of a market rebound are examined. The data includes stock returns for Nordic indices, two UK indices and other European indices (DAX 30, CAC 40, STOXX Europe 600) and two non-European indices (S&P 500 and Nikkei 225). The results of the event-study show that the immediate reaction on the next trading day on Nordic markets is very similar to that of the UK’s and other European markets. All Nordic, UK, German, France market indices and STOXX Europe 600 experienced significant negative abnormal returns between -3.30% and -8.85% in local currencies on the following trading day after the referendum. Despite this similar immediate reaction, the negative ARs did not last as long on Nordic markets as they did in non-Nordic Europe and Nordic markets rebound much quicker from their initial decline after the referendum. Still, overall the results highlight that the interconnectedness of European stock markets is high.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Rakennustyömaan jätehuollon kehittäminen

Ilmastonmuutos etenee. Maapallon populaatio käyttää luonnonvaroja 1,75 ja suomalaiset 4 kertaa enemmän kuin maapallo niitä tuottaa. Suomen kasvi-huonekaasupäästöistä jakautuu 32 % rakennusten käytölle ja 6 % rakenta-miselle. Luonnon monimuotoisuuden hupeneminen asettaa materiaalitehok-kuuden yhdeksi ihmiskunnan suurimmista haasteista. Täten on tärkeää löy-tää uusia keinoja jätteen määrän vähentämiseen sekä kierrätysasteen paran-tamiseen. Jätelain tavoitteena on, että rakennus- ja purkujätteestä hyödynnetään vähin-tään 70 painoprosenttia. Jätehuoltomääräysten tiukentuminen sekä kustan-nussäästöjen saavuttaminen laittavat jätteen vähentämisen erittäin tärkeään asemaan. Lisäksi toimivalla jätteenhuollolla pystytään vähentämään työmail-la tapahtuvia loukkaantumisia ja vaaratilanteita. Siisti ja turvallinen työympä-ristö parantaa myös työn tehokkuutta, mielialaa sekä työn laatua. Haasteita pystyy aiheutumaan esimerkiksi kohteen sijainnista, kiireisestä aikataulusta sekä huonoista asenteista. Tutkimuksen kohteena ollut rakennusyritys ha-vaitsi tarpeen löytää uusia keinoja jätehuollon ja jätteen vähentämisen kehit-tämiseen. Tässä opinnäytetyössä pyrittiin löytämään tapoja vähentää yrityk-sen työmaiden aiheuttamaa jätettä. Työn aikana vierailtiin kahdessa uudis-kohteessa sekä yhdessä korjaushankkeessa. Opinnäytetyön tuloksena syntyi keinoja vähentää rakennustyömaalla syntyvän jätteen määrää

Kirjallisuuskatsaus päihdepotilaan hoidosta päivystyspoliklinikalla

TIIVISTELMÄ Hartikainen, Aleksi & Lehtonen, Joel. Kirjallisuuskatsaus päihdepotilaan hoidosta päivystyspoliklinikalla. Helsinki, kevät 2013, 38 sivua, 1 liite. Diakonia-ammattikorkeakoulu, Diak Etelä, Helsinki. Hoitotyön koulutusohjelma, sairaanhoitaja (AMK). Opinnäytetyömme on kirjallisuuskatsaus aiheesta päihdepotilaan hoito päivys-tyspoliklinikalla. Aihe nousi Haartmanin sairaalan päivystyspoliklinikan tarpeesta kehittää päihdepotilaan hoitoa. Monivaiheisen suunnittelun jälkeen tutkimusmenetelmäksi valikoitui kirjallisuuskatsaus. Opinnäytetyön tavoite on laatia jo tehtyjä aiheeseen liittyviä julkaisuja luettelomaiseen muotoon tutkimusten saatavuuden helpottamiseksi. Luetteloa julkaisuista voidaan käyttää myös apuna perehdytys- ja koulutusmateriaalin hankinnassa ja laatimi-sessa. Opinnäytetyö sisältää tietoa päihteistä, niiden käyttöön liittyvistä ilmiöistä ja sii-tä, kuinka yhteiskunta pyrkii terveydenhuollon keinoin vastaamaan päihteiden käytön seurauksena aiheutuviin ongelmiin. Lisäksi käydään läpi päivystyspoli-kliinista hoitotyötä ja päivystyspoliklinikalle ohjautuvien päihdepotilaiden hoitoa. Päihteistä työ painottuu enimmäkseen alkoholiin. Kirjallisuuskatsauksen aineiston keruu on tehty neljää tietokantaa (Medic, Arto, Melinda, Cinahl) hyödyntäen. Lisäksi tietoa on yksittäisten vinkkien perusteella haettu suoraan Google-hakukoneen kautta (manuaalinen tiedonhaku). Kirjalli-suuskatsaukseen kelpaavat julkaisut ovat valittu neljän kriteerin perusteella. Näitä kriteereita ovat hakusanoilla löydetyt tulokset tietokannoista, julkaisuajankohta, suomenkielinen julkaisu ja julkaisun yhteys tutkimusongelmaan. Tutkimustulokset analysoitiin aineistoa tiivistämällä neljään kategoriaan: 1) päihdeongelma sairautena, 2) hoitajien kokemukset päihdehoitotyöstä, 3) poti-laiden kokemukset päihdehoitotyöstä ja 4) yhteiskunnan merkitys päihdeongelmien palvelun tarjoajana. Kirjallisuuden lukemisesta, koonnista ja analysoinnista on koottu taulukko liit-teenä lähdeluettelon jälkeen. Tässä taulukossa näkyvät julkaisujen otsikko, julkaisuajankohta, julkaisun laatijat, julkaisun lyhyt sisällönkuvaus ja hakuehdot tietokannoista. Asiasanat: päivystys, poliklinikat, hoitotyö, päihteet, kirjallisuuskatsausABSTRACT Hartikainen, Aleksi and Lehtonen, Joel. Literarure review of a caring of intoxicant patients in emergency unit. 38 p, 1 appendix. Language: Finnish. Helsinki, Spring 2013. Diaconia University of Applied Sciences. Degree Programme in Nursing. De-gree: Nurse The aim of the thesis is to produce a literature review which deals with the care of an intoxicant patient in the Emergency Health Centre. The subject is based on the working-related need in the emergency unit of Haartman hospital in Helsinki. We have found several subject-related publications including articles and studies from the chosen databases. We have edited the publications to the form of index which is founded as appendix. The index can easily be used by the staff of emergency unit of Haartman hospital. With the help of index it is easier to find the publications and to produce educational material. The thesis includes information on intoxicants and intoxicant abuse. In addition, there is a description of how society strives to reduce intoxicant abuse. We have clarified what the role of intoxicants is in emergency units. We have mainly concentrated on alcohol abuse among the intoxicant abusers. A collection of publications was searched with the help of four databases. The publications were also searched manually. The four different criteria have been defined how the publications have been accepted to the literature review. The publications were analyzed and summarized to four categories: the intoxi-cant abuse as a disease, experiences of nurse staff about intoxicant abuse, experiences of patients of intoxicant abuse and significance of society as a service provider for intoxicant patients. The index includes the date of publication, author of the publication, a short description of the contents and the search terms in databases. Keywords: After-Hours care, intoxicant abuse, literature revie

Adenoviral Gene Therapy Vectors in Clinical Use—Basic Aspects with a Special Reference to Replication-Competent Adenovirus Formation and Its Impact on Clinical Safety

Adenoviral vectors are commonly used in clinical gene therapy. Apart from oncolytic adenoviruses, vector replication is highly undesired as it may pose a safety risk for the treated patient. Thus, careful monitoring for the formation of replication-competent adenoviruses (RCA) during vector manufacturing is required. To render adenoviruses replication deficient, their genomic E1 region is deleted. However, it has been known for a long time that during their propagation, some viruses will regain their replication capability by recombination in production cells, most commonly HEK293. Recently developed RCA assays have revealed that many clinical batches contain more RCA than previously assumed and allowed by regulatory authorities. The clinical significance of the higher RCA content has yet to be thoroughly evaluated. In this review, we summarize the biology of adenovirus vectors, their manufacturing methods, and the origins of RCA formed during HEK293-based vector production. Lastly, we share our experience using minimally RCA-positive serotype 5 adenoviral vectors based on observations from our clinical cardiovascular gene therapy studies

Document retrieval on repetitive string collections.

Most of the fastest-growing string collections today are repetitive, that is, most of the constituent documents are similar to many others. As these collections keep growing, a key approach to handling them is to exploit their repetitiveness, which can reduce their space usage by orders of magnitude. We study the problem of indexing repetitive string collections in order to perform efficient document retrieval operations on them. Document retrieval problems are routinely solved by search engines on large natural language collections, but the techniques are less developed on generic string collections. The case of repetitive string collections is even less understood, and there are very few existing solutions. We develop two novel ideas, interleaved LCPs and precomputed document lists, that yield highly compressed indexes solving the problem of document listing (find all the documents where a string appears), top-k document retrieval (find the k documents where a string appears most often), and document counting (count the number of documents where a string appears). We also show that a classical data structure supporting the latter query becomes highly compressible on repetitive data. Finally, we show how the tools we developed can be combined to solve ranked conjunctive and disjunctive multi-term queries under the simple [Formula: see text] model of relevance. We thoroughly evaluate the resulting techniques in various real-life repetitiveness scenarios, and recommend the best choices for each case