Studies of working memory in interrupted human-computer interaction

Distraction in the workplace is increasingly more common in the information age. Several tasks and sources of information compete for a worker's limited cognitive capacities in human-computer interaction (HCI). In some situations even very brief interruptions can have detrimental effects on memory. Nevertheless, in other situations where persons are continuously interrupted, virtually no interruption costs emerge. This dissertation attempts to reveal the mental conditions and causalities differentiating the two outcomes. The explanation, building on the theory of long-term working memory (LTWM; Ericsson and Kintsch, 1995), focuses on the active, skillful aspects of human cognition that enable the storage of task information beyond the temporary and unstable storage provided by short-term working memory (STWM). Its key postulate is called a retrieval structure an abstract, hierarchical knowledge representation built into long-term memory that can be utilized to encode, update, and retrieve products of cognitive processes carried out during skilled task performance. If certain criteria of practice and task processing are met, LTWM allows for the storage of large representations for long time periods, yet these representations can be accessed with the accuracy, reliability, and speed typical of STWM. The main thesis of the dissertation is that the ability to endure interruptions depends on the efficiency in which LTWM can be recruited for maintaing information. An observational study and a field experiment provide ecological evidence for this thesis. Mobile users were found to be able to carry out heavy interleaving and sequencing of tasks while interacting, and they exhibited several intricate time-sharing strategies to orchestrate interruptions in a way sensitive to both external and internal demands. Interruptions are inevitable, because they arise as natural consequences of the top-down and bottom-up control of multitasking. In this process the function of LTWM is to keep some representations ready for reactivation and others in a more passive state to prevent interference. The psychological reality of the main thesis received confirmatory evidence in a series of laboratory experiments. They indicate that after encoding into LTWM, task representations are safeguarded from interruptions, regardless of their intensity, complexity, or pacing. However, when LTWM cannot be deployed, the problems posed by interference in long-term memory and the limited capacity of the STWM surface. A major contribution of the dissertation is the analysis of when users must resort to poorer maintenance strategies, like temporal cues and STWM-based rehearsal. First, one experiment showed that task orientations can be associated with radically different patterns of retrieval cue encodings. Thus the nature of the processing of the interface determines which features will be available as retrieval cues and which must be maintained by other means. In another study it was demonstrated that if the speed of encoding into LTWM, a skill-dependent parameter, is slower than the processing speed allowed for by the task, interruption costs emerge. Contrary to the predictions of competing theories, these costs turned out to involve intrusions in addition to omissions. Finally, it was learned that in rapid visually oriented interaction, perceptual-procedural expectations guide task resumption, and neither STWM nor LTWM are utilized due to the fact that access is too slow. These findings imply a change in thinking about the design of interfaces. Several novel principles of design are presented, basing on the idea of supporting the deployment of LTWM in the main task.

Storage and retrieval of individual genomes

A repetitive sequence collection is one where portions of a base sequence of length n are repeated many times with small variations, forming a collection of total length N. Examples of such collections are version control data and genome sequences of individuals, where the differences can be expressed by lists of basic edit operations. Flexible and efficient data analysis on a such typically huge collection is plausible using suffix trees. However, suffix tree occupies O(N log N) bits, which very soon inhibits in-memory analyses. Recent advances in full-text self-indexing reduce the space of suffix tree to O(N log σ) bits, where σ is the alphabet size. In practice, the space reduction is more than 10-fold, for example on suffix tree of Human Genome. However, this reduction factor remains constant when more sequences are added to the collection. We develop a new family of self-indexes suited for the repetitive sequence collection setting. Their expected space requirement depends only on the length n of the base sequence and the number s of variations in its repeated copies. That is, the space reduction factor is no longer constant, but depends on N / n. We believe the structures developed in this work will provide a fundamental basis for storage and retrieval of individual genomes as they become available due to rapid progress in the sequencing technologies.

Voittoa tavoittelemattoman organisaation brandin rakentaminen. Case Slow Food

Tämän pro gradu-tutkielman tavoitteena oli kartoittaa voittoa tavoittelemattoman Slow Food-organisaation brandiin liitettyjä mielikuvia ja niitä tekijöitä, joilla brandin tavoitekuvaa tulisi jatkossa rakentaa. Koska nykyisin brandi ei ole enää pelkkien liikeyritysten yksityisomaisuutta, tutkimuksen teoreettinen asemointi perustui yhtäältä organisaation tunnettuuden kasvattamiseen brandin rakentamisen avulla ja toisaalta voittoa tavoittelemattoman toimintaympäristön erityispiirteiden näkökulmaan. Case-osion avulla haluttiin tarkastella globalisaation ja elintarviketalouden keskittymiselle vaihtoehtoisen, paikallisuuteen perustuvan ruokajärjestelmän vaikutuksia, mahdollisuuksia ja haasteita. Tutkimuksen empiirinen osuus muodostui laadullisesta tapaustutkimuksesta, jonka kohteena oli Slow Food-organisaatio. Tutkimus suoritettiin haastattelemalla kahtatoista Slow Food-organisaation sidosryhmien edustajaa Italian Piemontessa henkilökohtaisin haastatteluin, joiden pohjana oli brandi identiteetin elementeistä luodut kaksi teemaa: mielleyhtymiin ja arvoväittämään liittyvät tekijät. Aineiston analysoinnissa käytettiin teemoittelua ja sisällönanalyysia. Tutkimuksen lähestymistapa oli abduktiivinen. Tulosten mukaan Slow Food-brandi identifioituu sidosryhmilleen ensisijaisesti luotettavan ruoan kautta, johon katsottiin kuuluvan aidot, puhtaat raaka-aineet ja paikallisesti tuotetun ja jalostamattoman ruoan hyvä jäljitettävyys. Myös tiettyyn paikkaan ja arvoihin sidottujen kokemusten ja odostusten täyttymisen kautta saatu sosiaalinen ja kulttuurinen jatkuvuus nimettiin brandin vahvuudeksi. Lisäksi vastuullisen tuottamisen ja kuluttamisen sekä aitojen makujen ja laadukkaan ruokavalion edistäminen korostuivat jonkin verran vastauksissa. Näillä perusvahvuuksilla toivottiin brandin identiteettiä rakennettavan myös tulevaisuudessa. Haastateltavien mielestä Slow Food-organisaatio erilaistaa itsensä muista ensisijaisesti lupaamalla yksilölle korkealuokkaisia, aitoja tuotteita ja palveluja, joilla on henkilökohtaisten hyötyjen lisäksi positiivisia seuraamuksia myös oman alueen työllisyyden ja talouden kehitykseen. Organisaation tulisi myös jatkossa luoda uskottavuutta toimintaansa eritoten sen kautta, että brandi lunastaa lupauksensa laadusta ja aitoudesta. Toisaalta erottautuakseen muista lähi- ja luomuruokabrandeista Slow Food-brandin arvoväittämässä tulisi tulevaisuudessa selkeämmin korostua myös toiminnan voittoa tavoittelemattomuus ja brandiin liittyvä elämyksellisyys. Sidosryhmien kiinnostusta ja brandin lupauksen tehoa alentaviksi tekijöiksi nimettiin yleinen ruoan arvostuksen väheneminen sekä Slow Food-tuotteiden ja -palvelujen korkea hinta, huono saatavuus ja näkyvyys. Keskeisimpinä ratkaisuina pidettiin kuluttajien informatiivisen tiedon lisäämisen ohella pientuottajien verkostoitumista ja uusia yhteistyön muotoja kuten tuottajien yhteisiä jakeluketjuja ja paikallismyymälöitä. Näiden lisäksi brandin tunnistettavuuden parantaminen ja aktiivisempi tarjonta kyltityksin, tuotteiden pysyvän läsnäolon ja vähittäiskaupan mukaantulon kautta sekä eräät muut markkinoinnin osa-alueet kuten sosiaalinen media, Internet ja kansainväliset ruoka-alan tapahtumat nimettiin brandin lupausta kirkastaviksi elementeiksi. Pientuotannon lisääminen verotuksen kohdentumisen muutoksilla nähtiin keinoksi pudottaa paikallisen ruoan hintaa.Toisaalta korkeaa hintaa perusteltiin laadukkaaseen imagoon liittyvien argumenttien lisäksi luonnollisen kysynnän kasvulla, jota arveltiin saatavan tulevaisuudessa suurista ikäluokista, yhä kasvavasta koulutus- ja tulotasosta sekä valveutuneemmista kuluttajista.

Lyophilized disaccharides – the effect of water during storage

Nearly one fourth of new medicinal molecules are biopharmaceutical (protein, antibody or nucleic acid derivative) based. However, the administration of these compounds is not always that straightforward due to the fragile nature of aforementioned domains in GI-tract. In addition, these molecules often exhibit poor bioavailability when administered orally. As a result, parenteral administration is commonly preferred. In addition, shelf-life of these molecules in aqueous environments is poor, unless stored in low temperatures. Another approach is to bring these molecules to anhydrous form via lyophilization resulting in enhanced stability during storage. Proteins cannot most commonly be freeze dried by themselves so some kind of excipients are nearly always necessary. Disaccharides are commonly utilized excipients in freeze-dried formulations since they provide a rigid glassy matrix to maintain the native conformation of the protein domain. They also act as "sink"-agents, which basically mean that they can absorb some moisture from the environment and still help to protect the API itself to retain its activity and therefore offer a way to robust formulation. The aim of the present study was to investigate how four amorphous disaccharides (cellobiose, melibiose, sucrose and trehalose) behave when they are brought to different relative humidity levels. At first, solutions of each disaccharide were prepared, filled into scintillation vials and freeze dried. Initial information on how the moisture induced transformations take place, the lyophilized amorphous disaccharide cakes were placed in vacuum desiccators containing different relative humidity levels for defined period, after which selected analyzing methods were utilized to further examine the occurred transformations. Affinity to crystallization, water sorption of the disaccharides, the effect of moisture on glass transition and crystallization temperature were studied. In addition FT-IR microscopy was utilized to map the moisture distribution on a piece of lyophilized cake. Observations made during the experiments backed up the data mentioned in a previous study: melibiose and trehalose were shown to be superior over sucrose and cellobiose what comes to the ability to withstand elevated humidity and temperature, and to avoid crystallization with pharmaceutically relevant moisture contents. The difference was made evident with every utilized analyzing method. In addition, melibiose showed interesting anomalies during DVS runs, which were absent with other amorphous disaccharides. Particularly fascinating was the observation made with polarized light microscope, which revealed a possible small-scale crystallization that cannot be observed with XRPD. As a result, a suggestion can safely be made that a robust formulation is most likely obtained by utilizing either melibiose or trehalose as a stabilizing agent for biopharmaceutical freeze-dried formulations. On the other hand, more experiments should be conducted to obtain more accurate information on why these disaccharides have better tolerance for elevating humidities than others.