440 resultados para test av mobila applikationer
Resumo:
Usability testing is a productive and reliable method for evaluating the usability of software. Planning and implementing the test and analyzing its results is typically considered time-consuming, whereas applying usability methods in general is considered difficult. Because of this, usability testing is often priorized lower than more concrete issues in software engineering projects. Intranet Alma is a web service, users of which consist of students and personnel of the University of Helsinki. Alma was published in 2004 at the opening ceremony of the university. It has 45 000 users, and it replaces several former university network services. In this thesis, the usability of intranet Alma is evaluated with usability testing. The testing method applied has been lightened to make its taking into use as easy as possible. In the test, six students each tried to solve nine test tasks with Alma. As a result concrete usability problems were described in the final test report. Goal-orientation was given less importance in the applied usability testing. In addition, the system was tested only with test users from the largest user group. Usability test found general usability problems that occurred no matter the task or the user. However, further evaluation needs to be done: in addition to the general usability problems, there are task-dependent problems, solving of which requires thorough gathering of users goals. In the basic structure and central functionality of Alma, for example in navigation, there are serious and often repeating usability problems. It would be of interest to verify the designed user interface solutions to these problems before taking them into use. In the long run, the goals of the users, that the software is planned to support, are worth gathering, and the software development should be based on these goals.
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Ett sätt att förbättra resultat i informationssökning är frågeutvidgning. Vid frågeutvidgning utökas användarens ursprungliga fråga med termer som berör samma ämne. Frågor som har stort likhetsvärde med ett dokument kan tänkas beskriva dokumentet väl och kan därför fungera som en källa för goda utvidgningstermer. Om tidigare frågor finns lagrade kan termer som hittas med hjälp av dessa användas som kandidater för frågeutvidgningstermer. I avhandlingen presenteras och jämförs tre metoder för användning av tidigare frågor vid frågeutvidgning. För att evaluera metodernas effektivitet, jämförs de med hjälp av sökmaskinen Lucene och en liten samling dokument som berör cancerforskning. Som jämförelseresultat används de omodifierade frågorna och en enkel pseudorelevansåterkopplingsmetod som inte använder sig av tidigare frågor. Ingen av frågeutvidgningsmetoderna klarade sig speciellt bra, vilket beror på att dokumentsamlingen och testfrågorna utgör en svår omgivning för denna typ av metoder.
Resumo:
The study examines various uses of computer technology in acquisition of information for visually impaired people. For this study 29 visually impaired persons took part in a survey about their experiences concerning acquisition of infomation and use of computers, especially with a screen magnification program, a speech synthesizer and a braille display. According to the responses, the evolution of computer technology offers an important possibility for visually impaired people to cope with everyday activities and interacting with the environment. Nevertheless, the functionality of assistive technology needs further development to become more usable and versatile. Since the challenges of independent observation of environment were emphasized in the survey, the study led into developing a portable text vision system called Tekstinäkö. Contrary to typical stand-alone applications, Tekstinäkö system was constructed by combining devices and programs that are readily available on consumer market. As the system operates, pictures are taken by a digital camera and instantly transmitted to a text recognition program in a laptop computer that talks out loud the text using a speech synthesizer. Visually impaired test users described that even unsure interpretations of the texts in the environment given by Tekstinäkö system are at least a welcome addition to complete perception of the environment. It became clear that even with a modest development work it is possible to bring new, useful and valuable methods to everyday life of disabled people. Unconventional production process of the system appeared to be efficient as well. Achieved results and the proposed working model offer one suggestion for giving enough attention to easily overlooked needs of the people with special abilities. ACM Computing Classification System (1998): K.4.2 Social Issues: Assistive technologies for persons with disabilities I.4.9 Image processing and computer vision: Applications Keywords: Visually impaired, computer-assisted, information, acquisition, assistive technology, computer, screen magnification program, speech synthesizer, braille display, survey, testing, text recognition, camera, text, perception, picture, environment, trasportation, guidance, independence, vision, disabled, blind, speech, synthesizer, braille, software engineering, programming, program, system, freeware, shareware, open source, Tekstinäkö, text vision, TopOCR, Autohotkey, computer engineering, computer science
Resumo:
Requirements engineering is an important phase in software development where customer's needs and expectations are transformed into a software requirements specification. The requirements specification can be considered as an agreement between the customer and the developer where both parties agree on the expected system features and behaviour. However, requirements engineers must deal with a variety of issues that complicate the requirements process. The communication gap between the customer and the developers is among typical reasons for unsatisfactory requirements. In this thesis we study how the use case technique could be used in requirements engineering in bridging the communication gap between the customer and development team. We also discuss how a use case description can be use cases can be used as a basis for acceptance test cases.
Resumo:
I arbetet analyseras de i mentalvårdslagen (1990/1116) stadgade förutsättningarna för psykiatrisk sjukhusvård oberoende av patientens vilja gällande myndiga patienter för vilka inte har utsetts en intressebevakare före fattandet av vårdbeslutet, samt bakgrunden till och en del av de svårigheter som förknippas med denna form av vård och härtill anknutet beslutsfattande. Problemen tillspetsas framförallt i situationer av intressekonflikt mellan patientens intressen respektive samhällets intressen. Utgångspunkten ligger främst i finländsk mentalvårdslagstiftning och rättspraxis, men för att på ett ändamålsenligt sätt kunna redogöra för bakgrunden till och förutsättningarna för dylikt förvaltningsrättsligt beslutsfattande görs även relevanta kopplingar till medicinska (psykiatriska) yrkesetiska riktlinjer och mentalvårdslagstiftning inom övriga Norden. Analysen omfattar även den Europeiska människorättsdomstolens praxis i fall som gäller frihetsberövande på basis av psykiatrisk vård, närmare bestämt artikel 5 (1)(e) i den europeiska människorättskonventionen. Patientens självbestämmanderätt, frihet och integritet är utgångspunkterna för alla slags vårdförhållanden. Dessa inbegriper bl.a. frivillighet och informerat samtycke då en person söker vård. Möjligheten att förordna en person till psykiatrisk vård oberoende av dennes vilja är ett lagstadgat undantag till dessa principer. Beslutsfattandet är bundet till strikta lagstadgade förutsättningar, vilkas bedömning kräver juridisk, men framförallt medicinsk kunskap, vilket också skapar gränser och utmaningar för de yrkespersoner som arbetar med dylika ärenden. Kombinationen av psykiatri, etik och juridik är nödvändig, men inte alltid enkel att göra, vilket märks inte minst på terminologin som tillämpas i mentalvårdslagstiftningen. I arbetet analyseras en del av den terminologi som tillämpas inom finsk och övrig nordisk mentalvårdslagstiftning. Syftet är att visa att definitionerna, tolkningarna, terminologin och synsättet på psykisk ohälsa som tillämpas inom den finländska mentalvårdslagstiftningen jämförelsevis kanske inte är de mest lämpliga eller tidsenliga. En annan svår uppgift, som framförallt lagstiftaren ställ(t)s inför, är utformningen av mentalvårdslagstiftning som är tillräckligt flexibel för att tillåta beaktande av särdragen i varje enskilt ärende, men som samtidigt är strikt nog för att förhindra godtycke och missbruk. En person som lider av allvarlig psykisk ohälsa befinner sig oftast i en ytterst utsatt position, och är ofta begränsat eller inte alls kapabel att göra en korrekt bedömning av sig själv och sin situation. Således sker den starka betoningen av patientens självbestämmanderätt på både gott och ont. Det är kanske inte alltid i en psykiatrisk patients bästa att få bestämma själv, vilket också är en av frågorna som omfattas av analysen i arbetet. Eftersom det psykiatriska vårdbeslutet till karaktären är ett (skriftligt) förvaltningsbeslut, skiljer det sig samtidigt från övrigt beslutsfattande inom vårdsektorn, vilket till största delen utgör faktisk förvaltningsverksamhet. För patienten innebär vårdbeslutet också ett administrativt frihetsberövande. Ingreppet i patientens grundläggande fri- och rättigheter är särskilt stort och upplevs ofta som mycket kränkande, och därför ställs särskilt strikta krav på iakttagande av det lagstadgade beslutsförfarandet och vårdförutsättningarna samt tillgodoseendet av patientens rättsskydd. Den offentliga hälso- och sjukvården är verksamhet som är underställd den offentliga förvaltningen, vilket innebär att de allmänna förvaltningsrättsliga rättsskyddsgarantierna är tillämpliga. I och med vårdbeslutets karaktär av förvaltningsbeslut, kan ändring i beslutet sökas genom besvär hos förvaltningsdomstolen. Dessa är också några av de frågor som behandlas i arbetet.
Resumo:
Forskningens utgångspunkt var att tillföra information om kvinnliga teologers liv i Svenskfinland under en period då kyrkan hade omdefinierat sin syn på kvinnor som präster. Till forskningens intresseområden hörde frågan om hur situationen hade påverkat kvinnors motivation att välja teologiska studier och yrken samt hur situationen hade inverkat på kvinnliga teologer i arbetslivet. Forskningens uppgift är att ur ett identitetsperspektiv undersöka målgruppens egna skildringar av livet som kvinnlig teolog i Svenskfinland. Forskningsfrågan delades in i två delfrågor: 1)Hur har kvinnliga teologer kommit att välja studier, yrken och arbetsplats? 2)Vad har kvinnliga teologer upplevt i sina studier och arbetsliv? Forskningens material samlades in hösten 2003 genom en förfrågan per brev och genom en tidningsnotis i tidningen Kyrkpressen. Materialet bestod av livsberättelser som kvinnliga teologer i olika yrkesgrupper hade skrivit utgående ifrån rubriken ”Mitt liv som kvinnlig teolog i Svenskfinland”. Cirka 250 kvinnor hade avlagt teologisk examen på svenska i Finland. Antalet personer som deltog i undersökningen med sin livsberättelse var 27. Materialet analyserades kvalitativt och induktivt med en narrativ analys som tog fasta på teman och berättelsetyper i olika livsskeden: val av studier, studietid, val av karriär och erfarenheter från arbetslivet. Analysresultatet var att studievalets beskrivning kunde tolkas som en valsituation där egenskaper jämfördes med yrkesrollen, som en socialisationsprocess, som ett alternativ till tidigare studieinriktning eller som en process där kvinnoprästdiskussioner, intresse för teologi och teologuppgifter fick informanten att välja teologin. Teman från studietiden handlade om studiers fördröjning, om yrkesinriktning, om studier som förberedelse för arbetslivet och om kvinnoprästdiskussionens inverkan på yrkesinriktningen. Val av arbetsplatser och yrken beskrevs utgående ifrån kvinnliga teologers förändrade position, moderskapets inverkan på karriären, en strävan att hitta en arbetsplats som passade informanten, erfarenheter från en enda arbetsplats och karriärsbyte. Lektorer tog fasta på välsignelseaktens betydelse, kyrkoherdens stora inflytande på arbetets karaktär samt hur situationen förändrades då kvinnor tilläts bli präster. För en del präster innebar prästrollen att andra människor betonade att de var kvinnor. Några informanter hade behov av stöd både från Borgå stifts ledning och från andra kvinnliga präster under den första tiden med kvinnliga präster. Till en början upplevdes ledningens stöd inte alltid som tillräckligt men det förbättrades med tiden. Informanterna berättade inte så mycket om läraryrket. Inom forskning verkade teologtiteln vara naturlig, medan informanter med erfarenhet av annat än teologyrken ibland hade stött på reaktioner på sitt yrkesval eller sin arbetsroll. Finlandssvenskheten upplevdes av olika informanter både som tryggt och inskränkt. Eventuella kontakter till finska stift upplevdes positivt även om det egna sammanhanget upplevdes som viktigt. Trivsel på arbetsplatsen orsakades av subjektiva belöningar och i en del fall av att arbetet motsvarade informantens yrkesinriktning. Att vara kvinnlig teolog innebar ibland att informantens yrkesval tolkades av andra som ett ställningstagande för någon ideologi i kvinnoprästfrågan.
Resumo:
A vast amount of public services and goods are contracted through procurement auctions. Therefore it is very important to design these auctions in an optimal way. Typically, we are interested in two different objectives. The first objective is efficiency. Efficiency means that the contract is awarded to the bidder that values it the most, which in the procurement setting means the bidder that has the lowest cost of providing a service with a given quality. The second objective is to maximize public revenue. Maximizing public revenue means minimizing the costs of procurement. Both of these goals are important from the welfare point of view. In this thesis, I analyze field data from procurement auctions and show how empirical analysis can be used to help design the auctions to maximize public revenue. In particular, I concentrate on how competition, which means the number of bidders, should be taken into account in the design of auctions. In the first chapter, the main policy question is whether the auctioneer should spend resources to induce more competition. The information paradigm is essential in analyzing the effects of competition. We talk of a private values information paradigm when the bidders know their valuations exactly. In a common value information paradigm, the information about the value of the object is dispersed among the bidders. With private values more competition always increases the public revenue but with common values the effect of competition is uncertain. I study the effects of competition in the City of Helsinki bus transit market by conducting tests for common values. I also extend an existing test by allowing bidder asymmetry. The information paradigm seems to be that of common values. The bus companies that have garages close to the contracted routes are influenced more by the common value elements than those whose garages are further away. Therefore, attracting more bidders does not necessarily lower procurement costs, and thus the City should not implement costly policies to induce more competition. In the second chapter, I ask how the auctioneer can increase its revenue by changing contract characteristics like contract sizes and durations. I find that the City of Helsinki should shorten the contract duration in the bus transit auctions because that would decrease the importance of common value components and cheaply increase entry which now would have a more beneficial impact on the public revenue. Typically, cartels decrease the public revenue in a significant way. In the third chapter, I propose a new statistical method for detecting collusion and compare it with an existing test. I argue that my test is robust to unobserved heterogeneity unlike the existing test. I apply both methods to procurement auctions that contract snow removal in schools of Helsinki. According to these tests, the bidding behavior of two of the bidders seems consistent with a contract allocation scheme.
Resumo:
Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is road dust . The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: i) How do traction sanding and physical properties of the traction sand aggregate affect formation of road dust? ii) How do studded tires affect the formation of road dust when compared with friction tires? iii) What are the composition and sources of airborne road dust in a road simulator and during a springtime road dust episode in Finland? iv) What is the size distribution of abrasion particles from tire-road interaction? The studies were conducted both in a road simulator and in field conditions. The test results from the road simulator showed that traction sanding increased road dust emissions, and that the effect became more dominant with increasing sand load. A high percentage of fine-grained anti-skid aggregate of overall grading increased the PM10 concentrations. Anti-skid aggregate with poor resistance to fragmentation resulted in higher PM levels compared with the other aggregates, and the effect became more significant with higher aggregate loads. Glaciofluvial aggregates tended to cause higher particle concentrations than crushed rocks with good fragmentation resistance. Comparison of tire types showed that studded tires result in higher formation of PM emissions compared with friction tires. The same trend between the tires was present in the tests with and without anti-skid aggregate. This finding applies to test conditions of the road simulator with negligible resuspension. Source and composition analysis showed that the particles in the road simulator were mainly minerals and originated from both traction sand and pavement aggregates. A clear contribution of particles from anti-skid aggregate to ambient PM and dust deposition was also observed in urban conditions. The road simulator results showed that the interaction between tires, anti-skid aggregate and road surface is important in dust production and the relative contributions of these sources depend on their properties. Traction sand grains are fragmented into smaller particles under the tires, but they also wear the pavement aggregate. Therefore particles from both aggregates are observed. The mass size distribution of traction sand and pavement wear particles was mainly coarse, but fine and submicron particles were also present.
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Forestry has influenced forest dwelling organisms for centuries in Fennoscandia. For example, in Finland ca. 30% of the threatened species are threatened because of forestry. Nowadays forest management recommendations include practices aimed at maintaining biodiversity in harvesting, such as green-tree retention. However, the effects of these practices have been little studied. In variable retention, different numbers of trees are retained, varying from green-tree retention (at least a few live standing trees in clear-cuts) to thinning (only individual trees removed). I examined the responses of ground-dwelling spiders and carabid beetles to green-tree retention (with small and large tree groups), gap felling and thinning aimed at an uneven age structure of trees. The impacts of these harvesting methods were compared to those of clear-cutting and uncut controls. I aimed to test the hypothesis that retaining more trees positively affects populations of those species of spiders and carabids that were present before harvesting. The data come from two studies. First, spiders were collected with pitfall traps in south-central Finland in 1995 (pre-treatment) and 1998 (after-treatment) in order to examine the effects of clear-cutting, green-tree retention (with 0.01-0.02-ha sized tree groups), gap felling (with three 0.16-ha sized openings in a 1-ha stand), thinning aiming at an uneven age structure of trees and uncut control. Second, spiders and carabids were caught with pitfall traps in eastern Finland in 1998-2001 (pre-treatment and three post-treatment years) in eleven 0.09-0.55-ha sized retention-tree groups and clear-cuts adjacent to them. Original spider and carabid assemblages were better maintained after harvests that retained more trees. Thinning maintained forest spiders well. However, gap felling and large retention-tree groups maintained some forest spider and carabid species in the short-term, but negatively affected some species over time. However, use of small retention-tree groups was associated with negative effects on forest spider populations. Studies are needed on the long-term effects of variable retention on terrestrial invertebrates; especially those directed at defining appropriate retention patch size and on the importance of structural diversity provided by variable retention for invertebrate populations. However, the aims of variable retention should be specified first. For example, are retention-tree groups planned to constitute life-boats , stepping-stones or to create structural diversity? Does it suffice that some species are maintained, or do we want to preserve the most sensitive ones, and how are these best defined? Moreover, the ecological benefits and economic costs of modified logging methods should be compared to other approaches aimed at maintaining biodiversity.
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Evolutionary history of biological entities is recorded within their nucleic acid sequences and can (sometimes) be deciphered by thorough genomic analysis. In this study we sought to gain insights into the diversity and evolution of bacterial and archaeal viruses. Our primary interest was pointed towards those virus groups/families for which comprehensive genomic analysis was not previously possible due to the lack of sufficient amount of genomic data. During the course of this work twenty-five putative proviruses integrated into various prokaryotic genomes were identified, enabling us to undertake a comparative genomics approach. This analysis allowed us to test the previously formulated evolutionary hypotheses and also provided valuable information on the molecular mechanisms behind the genome evolution of the studied virus groups.
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During the last 10-15 years interest in mouse behavioural analysis has evolved considerably. The driving force is development in molecular biological techniques that allow manipulation of the mouse genome by changing the expression of genes. Therefore, with some limitations it is possible to study how genes participate in regulation of physiological functions and to create models explaining genetic contribution to various pathological conditions. The first aim of our study was to establish a framework for behavioural phenotyping of genetically modified mice. We established comprehensive battery of tests for the initial screening of mutant mice. These included tests for exploratory and locomotor activity, emotional behaviour, sensory functions, and cognitive performance. Our interest was in the behavioural patterns of common background strains used for genetic manipulations in mice. Additionally we studied the behavioural effect of sex differences, test history, and individual housing. Our findings highlight the importance of careful consideration of genetic background for analysis of mutant mice. It was evident that some backgrounds may mask or modify the behavioural phenotype of mutants and thereby lead to false positive or negative findings. Moreover, there is no universal strain that is equally suitable for all tests, and using different backgrounds allows one to address possible phenotype modifying factors. We discovered that previous experience affected performance in several tasks. The most sensitive traits were the exploratory and emotional behaviour, as well as motor and nociceptive functions. Therefore, it may be essential to repeat some of the tests in naïve animals for assuring the phenotype. Social isolation for a long time period had strong effects on exploratory behaviour, but also on learning and memory. All experiments revealed significant interactions between strain and environmental factors (test history or housing condition) indicating genotype-dependent effects of environmental manipulations. Several mutant line analyses utilize this information. For example, we studied mice overexpressing as well as those lacking extracellular matrix protein heparin-binding growth-associated molecule (HB-GAM), and mice lacking N-syndecan (a receptor for HB-GAM). All mutant mice appeared to be fertile and healthy, without any apparent neurological or sensory defects. The lack of HB-GAM and N-syndecan, however, significantly reduced the learning capacity of the mice. On the other hand, overexpression of HB-GAM resulted in facilitated learning. Moreover, HB-GAM knockout mice displayed higher anxiety-like behaviour, whereas anxiety was reduced in HB-GAM overexpressing mice. Changes in hippocampal plasticity accompanied the behavioural phenotypes. We conclude that HB-GAM and N-syndecan are involved in the modulation of synaptic plasticity in hippocampus and play a role in regulation of anxiety- and learning-related behaviour.
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Staphylococcus aureus is one of the most important bacteria that cause disease in humans, and methicillin-resistant S. aureus (MRSA) has become the most commonly identified antibiotic-resistant pathogen in many parts of the world. MRSA rates have been stable for many years in the Nordic countries and the Netherlands with a low MRSA prevalence in Europe, but in the recent decades, MRSA rates have increased in those low-prevalence countries as well. MRSA has been established as a major hospital pathogen, but has also been found increasingly in long-term facilities (LTF) and in communities of persons with no connections to the health-care setting. In Finland, the annual number of MRSA isolates reported to the National Infectious Disease Register (NIDR) has constantly increased, especially outside the Helsinki metropolitan area. Molecular typing has revealed numerous outbreak strains of MRSA, some of which have previously been associated with community acquisition. In this work, data on MRSA cases notified to the NIDR and on MRSA strain types identified with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and staphylococcal cassette chromosome mec (SCCmec) typing at the National Reference Laboratory (NRL) in Finland from 1997 to 2004 were analyzed. An increasing trend in MRSA incidence in Finland from 1997 to 2004 was shown. In addition, non-multi-drug resistant (NMDR) MRSA isolates, especially those resistant only to methicillin/oxacillin, showed an emerging trend. The predominant MRSA strains changed over time and place, but two internationally spread epidemic strains of MRSA, FIN-16 and FIN-21, were related to the increase detected most recently. Those strains were also one cause of the strikingly increasing invasive MRSA findings. The rise of MRSA strains with SCCmec types IV or V, possible community-acquired MRSA was also detected. With questionnaires, the diagnostic methods used for MRSA identification in Finnish microbiology laboratories and the number of MRSA screening specimens studied were reviewed. Surveys, which focused on the MRSA situation in long-term facilities in 2001 and on the background information of MRSA-positive persons in 2001-2003, were also carried out. The rates of MRSA and screening practices varied widely across geographic regions. Part of the NMDR MRSA strains could remain undetected in some laboratories because of insufficient diagnostic techniques used. The increasing proportion of elderly population carrying MRSA suggests that MRSA is an emerging problem in Finnish long-term facilities. Among the patients, 50% of the specimens were taken on a clinical basis, 43% on a screening basis after exposure to MRSA, 3% on a screening basis because of hospital contact abroad, and 4% for other reasons. In response to an outbreak of MRSA possessing a new genotype that occurred in a health care ward and in an associated nursing home of a small municipality in Northern Finland in autumn 2003, a point-prevalence survey was performed six months later. In the same study, the molecular epidemiology of MRSA and methicillin-sensitive S. aureus (MSSA) strains were also assessed, the results to the national strain collection compared, and the difficulties of MRSA screening with low-level oxacillin-resistant isolates encountered. The original MRSA outbreak in LTF, which consisted of isolates possessing a nationally new PFGE profile (FIN-22) and internationally rare MLST type (ST-27), was confined. Another previously unrecognized MRSA strain was found with additional screening, possibly indicating that current routine MRSA screening methods may be insufficiently sensitive for strains possessing low-level oxacillin resistance. Most of the MSSA strains found were genotypically related to the epidemic MRSA strains, but only a few of them had received the SCCmec element, and all those strains possessed the new SCCmec type V. In the second largest nursing home in Finland, the colonization of S. aureus and MRSA, and the role of screening sites along with broth enrichment culture on the sensitivity to detect S. aureus were studied. Combining the use of enrichment broth and perineal swabbing, in addition to nostrils and skin lesions swabbing, may be an alternative for throat swabs in the nursing home setting, especially when residents are uncooperative. Finally, in order to evaluate adequate phenotypic and genotypic methods needed for reliable laboratory diagnostics of MRSA, oxacillin disk diffusion and MIC tests to the cefoxitin disk diffusion method at both +35°C and +30°C, both with or without an addition of sodium chloride (NaCl) to the Müller Hinton test medium, and in-house PCR to two commercial molecular methods (the GenoType® MRSA test and the EVIGENETM MRSA Detection test) with different bacterial species in addition to S. aureus were compared. The cefoxitin disk diffusion method was superior to that of oxacillin disk diffusion and to the MIC tests in predicting mecA-mediated resistance in S. aureus when incubating at +35°C with or without the addition of NaCl to the test medium. Both the Geno Type® MRSA and EVIGENETM MRSA Detection tests are usable, accurate, cost-effective, and sufficiently fast methods for rapid MRSA confirmation from a pure culture.
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Neuronal plasticity is a well characterized phenomenon in the developing and adult brain. It refers to capasity of a single neuron to modify morphology, synaptic connections and activity. Neuronal connections and capacity for plastic events are compromised in several pathological disorders, such as major depression. In addition, neuronal atrophy has been reported in depressive patients. Neurotrophins are a group of secretory proteins functionally classified as neuronal survival factors. Neurotrophins, especially brain derived neurotrophic factor (BDNF), have also been associated with promoting neuronal plasticity in dysfunctional neuronal networks. Chronic antidepressant treatment increases plastic events including neurogenesis and arborization and branching of neurites in distinct brain areas, such as the hippocampus. One suggested mode of action is where the antidepressants elevate the synaptic levels of BDNF thus further activating several signaling cascades via trkB-receptor. In our studies we have tried to clarify the mechanisms of action for antidepressants and to resolve the role of BDNF in this process. We found that chronic antidepressant treatment increases amount of markers of neuronal plasticity in both hippocampus and in the medial prefrontal cortex, both of which are closely linked to the etiology of major depression. Secondary actions of antidepressants include rapid activation of the trkB receptor followed by a phosphorylation of transcription factor CREB. In addition, activation of CREB by phosphorylation appears responsible for the regulation of the expression of the BDNF gene. Using transgenic mice we found that BDNF-induced trkB-mediated signaling proved crucial for the behavioral effects of antidepressants in the forced swimming test and for the survival of newly-born neurons in the adult hippocampus. Antidepressants not only increased neurogenesis in the adult hippocampus but also elevated the turnover of hippocampal neurons. During these studies we also discovered that another trkB ligand, NT-4, is involved in morphine-mediated anti-nociception and tolerance. These results present a novel role for trkB-mediated signaling in plastic events present in the opioid system. This thesis evaluates neuronal plasticity and trkB as a target for future antidepressant treatments.
Resumo:
Transposons are mobile elements of genetic material that are able to move in the genomes of their host organisms using a special form of recombination called transposition. Bacteriophage Mu was the first transposon for which a cell-free in vitro transposition reaction was developed. Subsequently, the reaction has been refined and the minimal Mu in vitro reaction is useful in the generation of comprehensive libraries of mutant DNA molecules that can be used in a variety of applications. To date, the functional genetics applications of Mu in vitro technology have been subjected to either plasmids or genomic regions and entire genomes of viruses cloned on specific vectors. This study expands the use of Mu in vitro transposition in functional genetics and genomics by describing novel methods applicable to the targeted transgenesis of mouse and the whole-genome analysis of bacteriophages. The methods described here are rapid, efficient, and easily applicable to a wide variety of organisms, demonstrating the potential of the Mu transposition technology in the functional analysis of genes and genomes. First, an easy-to-use, rapid strategy to generate construct for the targeted mutagenesis of mouse genes was developed. To test the strategy, a gene encoding a neuronal K+/Cl- cotransporter was mutagenised. After a highly efficient transpositional mutagenesis, the gene fragments mutagenised were cloned into a vector backbone and transferred into bacterial cells. These constructs were screened with PCR using an effective 3D matrix system. In addition to traditional knock-out constructs, the method developed yields hypomorphic alleles that lead into reduced expression of the target gene in transgenic mice and have since been used in a follow-up study. Moreover, a scheme is devised to rapidly produce conditional alleles from the constructs produced. Next, an efficient strategy for the whole-genome analysis of bacteriophages was developed based on the transpositional mutagenesis of uncloned, infective virus genomes and their subsequent transfer into susceptible host cells. Mutant viruses able to produce viable progeny were collected and their transposon integration sites determined to map genomic regions nonessential to the viral life cycle. This method, applied here to three very different bacteriophages, PRD1, ΦYeO3 12, and PM2, does not require the target genome to be cloned and is directly applicable to all DNA and RNA viruses that have infective genomes. The method developed yielded valuable novel information on the three bacteriophages studied and whole-genome data can be complemented with concomitant studies on individual genes. Moreover, end-modified transposons constructed for this study can be used to manipulate genomes devoid of suitable restriction sites.