Biological invasions are a major threat to biodiversity world wide with annual economic costs up to 1.4 trillion dollars. The round goby (Neogobius melanostomus) is a particularly fierce invader that threatens ecological function of the Baltic Sea. Individual variation in behavioral traits that remain constant through time and context have been identified as crucial factors for explaining different parts of the invasion process. For example, asocial behavior facilitates dispersal from high density populations and comes with fitness benefits in low conspecific density. The latter is especially relevant, in an invasion context, following the initial colonization of a novel environment when population density usually is low. This thesis investigates the role of individual variation in phenotypic traits on species invasions. The main focus is on the effects of sociability, activity and boldness, but also including aggression and physiological stress tolerance, on dispersal tendency and selection at invasion fronts. To do this, we studied four round goby populations in the Baltic Sea, two of the most recently established and two of the oldest populations. In 2012 we demonstrated that asocial, active and bold round gobies are overrepresented at invasion fronts. Two years later we showed that dispersal from the new populations was led by individuals with high activity levels, while in all populations larger individuals dispersed. We also determined the length of the socalled lag-phase, between colonization and spread, in both newly established populations. The end of the lag-phase is hypothesized being triggered by high population density in the harbors leading to dispersal and subsequen colonization of the surrounding areas by small asocial individuals. In our final experiment, we present evidence of stress coping styles in round gobies, in which more aggressive individuals are also more stress tolerant and vice versa. Though we found no connection between stress coping and population age, we found that mortality was unaffected by population density and that the gobies became more aggressive and stress tolerant when kept in high density. To conclude, we have shown that: 1) individuals with high levels of activity, boldness and asociality are common at invasion fronts; 2) a lag phase occurs between colonization and spread in round goby invasions; 3) asocial individuals drive the spread from high density populations at the invasion front and; 4) round gobies adapt to high densities with high aggression and stress tolerance.

The limited spatial resolution in positron emission tomography (PET) images leads to difficulties to measure correct uptake in tumours. This is called partial volume effects (PVE) and can lead to serious bias, especially for small tumours. Correct uptake values are valuable for evaluating therapies and can be used as a tool for treatment planning. The purpose of this project was to evaluate two methods for compensating for PVE. Also, a method for tumour delineation in PET-images was evaluated. The methods were used on images reconstructed with two algorithms, VUE-point HD (VP HD) and VP SharpIR. The evaluation was performed using a phantom including fillable spheres which were used to simulate tumours of different sizes. The first method used for PVE compensation was an iterative deconvolution method which to some degree restores the spatial resolution in the images. The tumour uptake was measured with volumes of interest (VOIs) based on a percentage of the maximum voxel value. The second method was to use recovery coefficients (RCs) as correction factors for the measured activity concentrations. These were calculated by convolving binary images of tumours with the point spread function (PSF). The binary images were achieved both from computed tomography (CT) images and from PET images with a threshold method for tumour delineation. The threshold method was based on both tumour activity and background activity, and was also compared with a conventional threshold technique. The results showed that images reconstructed with VP SharpIR can be used for activity concentration measurements with good precision for tumours larger than 13mm diameter. Smaller tumours benefit from RCs correction. The threshold method for tumour delineation showed substantially better results compared to the conventional threshold method. / Den begränsade spatiella upplösningen i bilder från positronemissions-tomografi (PET) leder till svårigheter i att mäta korrekt upptag i tumörer. Detta kallas partiella volymseffekter (PVE) och kan leda till stora fel, speciellt för små tumörer. Korrekta upptagsvärden är värdefulla vid behandlingsutvärdering och kan användas som ett verktyg för att planera behandlingar. Syftet med detta projekt var att utvärdera två metoder för att kompensera för PVE. Även en metod för tumöravgränsning i PET-bilder utvärderades. Metoderna användes på bilder som rekonstruerats med två olika algoritmer, VUE-point HD (VP HD) och VP SharpIR. Utvärderingen utfördes med ett fantom med sfärer som fylldes med aktivitet och därmed simulerade tumörer av olika storlekar. Den första metoden för PVE-kompensation var en iterativ avfaltningsmetod som, i viss mån, återställer bildernas spatiella upplösning. Upptaget i tumörerna mättes som medelupptaget i s.k. ”volumes of interests” (VOI:ar) som baserades på andelar av maximala voxelvärdet. Den andra metoden byggde på användning av s.k. recovery coefficients (RCs) som korrektionsfaktorer för de uppmätta aktivitetskoncentrationerna. Dessa beräknades genom att falta binära bilder av tumörerna med punktspridningsfunktionen (PSF). De binära bilderna framställdes både från bilder tagna med datortomografi (computed tomography, CT) och från PET-bilder med en tröskelmetod för tumöravgränsning. Tröskelmetoden baserades både på aktiviteten i tumören och på bakgrundsaktiviteten. Den jämfördes också med en konventionell tröskelmetod. Resultaten visade att bilder som rekonstruerats med VP SharpIR kan användas för mätning av aktivitetskoncentration med god precision för tumörer större än 13mm diameter. För mindre tumörer är det bättre att använda RC:s. Tröskelmetoden för tumöravgränsning visade avsevärt bättre resultat jämfört med den traditionella tröskelmetoden.

Nous avons essayé dans le cadre de cette thèse de comprendre le processus de notation des entreprises de différentes zones géographiques et secteurs d'activité. Pour ce faire, nous avons décidé de ventiler notre étude en trois phases principales, en l'occurrence une première phase réservée à l'étude du processus de notation en tenant compte de la durée des épisodes, une seconde phase consacrée à l'étude de l'effet de la crise sur ce processus et une troisième phase consacrée à l'étude de la contagion.

XX amžiuje skirtingų tautų kultūros neišvengiamai sąveikauja tarpusavyje, daro įtaką viena kitai ir tuo pačiu viena kitą. Pagyvėjus kultūriniams mainams Europoje pradėta gana aktyviai domėtis Lotynų Amerikos kultūra ir, žinoma, viena iš domėjimąsi sukėlusių kultūros sričių yra muzika, kadangi ji yra labai plačiai paplitusi kultūros sritis, t.y. muzikinis ugdymas vyksta ne tik ugdymo institucijose, bet ir už jų ribų. Daugiausiai apie Lotynų Amerikos muziką išgirstame ir sužinome iš tokių informacjos šaltinių kaip televizija, radijas, internetas, kurių pagalba tapo labiau prieinami kitų šalių muzikos atlikėjų video ir audio įrašai. Jaunimo vertybinėms nuostatoms ir pasaulėjautai daro įtaką Vakarų Europos kultūra, vedinas madų jis klausosi Lotynų Amerikos muzikos, kuri greta kitos pramoginės muzikos, šiuo metu jau yra tapusi Lietuvos kultūros dalimi. Nežiūrint to, kad Lotynų Amerikos šalių muzikinę kultūrą sudaro labai įvairi, skirtingų laikmečių, stilių bei žanrų muziką, populiariausi ir plačiausiai paplitę yra popmuzikos žanrai. Šia muzika daugiausiai domisi jaunimas, kuriems dažniai masinė popkultūra yra neatsiejama laisvalaikio praleidimo dalis. Klubai, šokių studijos organizuoja įvairius koncertus, renginius, seminarus, kur susiburia įvairių profesijų žmonės besidomintys ne tik šokiu, bet ir apskritai Lotynų Amerikos šalių kultūra. Bendraminčiai dalyvauja muzikinėje veikloje, kurioje išreiškia save, dalinasi žiniomis ir įgyta patirtimi. Tyrimo objektas – Lotynų Amerikos... [toliau žr. visą tekstą] / Nations of different cultures in the 20th century are inevitably interacting and influencing each other, and act upon each other. At more lively cultural exchange in Europe, quite active interest in Latin American culture started to grow and, certainly, one of the fields causing the interest in culture is music because music is a very popular field of culture, i.e. the musical upbringing takes place not only in educational institutions but also outside them. Most of all we hear about the Latin American music and we find out the facts from such information sources as television, radio, internet, all of them helping to bring the video and audio records of the performers from other countries closer to us. The values and viewpoints of the youth are being influenced by the West European culture; guided by fashion trends. The youth is listening the Latin American music that, in line with other entertainment music, has already become an integral part of Lithuanian culture. Despite the fact that musical culture of Latin American countries is varied and rich by the diversity of styles, periods, and genres, the most popular and most widespread ones are the pop-genres. This music is a centerpiece of interests of young people for whom often the mass pop culture is an inseparable way of leisure. Clubs, dance studies organize different concerts, events, seminars where people of different professions interested not only in dancing but in the culture of Latin American countries in general... [to full text]

A sign pattern matrix is a matrix whose entries are from the set {+,-, 0}. For a real matrix B, sgn(B) is the sign pattern matrix obtained by replacing each positive respectively, negative, zero) entry of B by + (respectively, -, 0). For a sign pattern matrixA, the sign pattern class of A, denoted Q(A), is defined as { B : sgn(B)= A }. The minimum rank mr(A)(maximum rank MR(A)) of a sign pattern matrix A is the minimum (maximum) of the ranks of the real matrices in Q(A). Several results concerning sign patterns A that require almost unique rank, that is to say, the sign patterns A such that MR(A)= mr(A)+1 are established. In particular, a complete characterization of these sign patterns is obtained. Further, the results on sign patterns that require almost unique rank are extended to sign patterns A for which the spread is d =MR(A)-mr(A).

Military grounds are territories with specific purpose. Various kinds of military installations, ammunitions and explosives are used in such areas. Because of these reasons, soil in military grounds is very often polluted with heavy metals and oil products; because of continuous damages, made to the top soil, vegetation is very scarce, in some spots missing – sandy wastelands are formed. Explosions, performed in military grounds, can be characterized by both thermal and chemical effect (soil pollution with such compounds, like lead, zinc, copper etc). Not only soils in military grounds and surrounding areas can be polluted because of military activities, but surface water bodies and groundwater as well. Aiming on determination and estimation of the level of pollution and disturbance of superficial layer of soil in military grounds, it is essential to do comprehensive research on physical (explosions and other mechanical effects) and chemical (pollution with heavy metals) effects on soil, caused by militaryactivities, and to evaluate potential danger of pollutants spread and groundwater pollution. It is important to foreseen changes of soil damage and pollution depending on impact strength, type and intensity of military action, performed in specific area, and to evaluate pollution dispersion in deeper layers of soil, relying on investigation results and long-term prognosis. It is necessary to apply and elaborate effective methods for cleaning of polluted soils from military... [to full text]

Šio darbo objektas yra informacijos, klaidinančios vartotoją, sklaida ir jos įtaka organizacijos įvaizdžiui. Darbo tikslas – remiantis keleto atvejų Lietuvoje analize, atskleisti vartotojus klaidinančios informacijos sklaidos įtaką internetinės prekybos organizacijų įvaizdžiui. Darbo sudaro trys skyriai: pirmoje darbo dalyje pristatoma elektroninio verslo bei internetinės prekybos samprata, pristatomos organizacijos identiteto kūrimo, įvaizdžio formavimo bei palaikymo procesų ir išorinės komunikacijos sąsajos; antroje darbo dalyje analizuojama vartotoją klaidinančios informacijos sklaida bei organizacijos atsakomybės klausimai; trečiojoje darbo dalyje – aprašoma empirinio tyrimo metodologija ir analizuojami tyrimo metu gauti duomenys. Tyrimas buvo atliekamas keliais etapais. Pirmiausia buvo apklausti keturi internetinės prekybos organizacijų Lietuvoje vadovai. Interviu metu išsiaiškinta, kokią įtaką vartotojus klaidinančios informacijos sklaida turi internetinės prekybos organizacijų įvaizdžiui bei komunikacijai. Taip pat buvo atliktas kiekybinis tyrimas, kuris padėjo nubrėžti gaires bei žvalgomąsias tendencijas, ar vartotojams Lietuvoje apskritai yra svarbi adekvačios bei teisingos informacijos apie produktus bei paslaugas sklaida. Tyrimas atskleidė, kad vartotojams yra svarbi teisingos ir adekvačios informacijos apie produktus bei paslaugas sklaida. Jie pripažįsta, jog netoleruoja klaidinančios informacijos, tačiau vis dar susiduria su ja apsipirkdami internetu... [toliau žr. visą tekstą] / The object of investigation of master thesis is spread of misleading information to consumers and its impact to the image of organization. Master thesis aims at revealing the impact of misleading information to consumers on the image of the online sales companies in accordance with few cases of analysis in Lithuania. The thesis consists of three chapters: first chapter deals with online business and sales, also the development of organization identity, forming and sustaining image and the correlation of external communication; spread of misleading information and the responsibility of organization are discussed in the second part; whereas in the third part of the thesis the methodology of empirical research is described, also gathered data is analyzed. Research was performed in few stages. Firstly, four of online sales Lithuanian organizations directors were interviewed. During the interviews it was revealed what kind of impact spread of misleading information to consumers does to the image and communication of organizations. Quantitative research has been performed as well. It helped to determine guidelines and trends related to finding out if consumers in Lithuania need spread of adequate and legitimate information concerned with products and services. Research revealed that consumers need spread of adequate and legitimate information concerned with products and services. Consumers admit that they do not tolerate misleading information, however they still find such... [to full text]

This dissertation exammes two of the rlsing technologies in the world of wireless, cellular communications - CDMA and the software radio. This thesis covers many of the issues related to these two emerging field s of wireless communications, establish ing a theoretical framework for the broader issues of implementation. To this end, the thesis covers many of the basic issues of spread spectrum communications, in addition to establishing the need for, and defining the role of, the software radio. Amalgamation of these two key areas of interest is embellished in a presentation of many of the concerns of implementing a specific CDMA system on a particular type of software radio - the Alcatel Altech Telecomms Flexible Radio Platform. Of primary concern in the research methodology embraced in this thesis is the mastering of a variety of analysis and implementation tools. Once the theoretical background has been substantiated by current expositions, the thesis launches along a highly deterministic route. First, the research issues are tested in a mathematical environment for suitability to the given task. Second, an analysis of the appropriateness of the technique for the software radio environment is undertaken, culminating in the attempted deployment within the hardware environmenl. Rigorous testing of the input/output mapping characteristics of the hardware instantiations created in this manner complements the research methodology with a viability study. This procedure is repeated with many elements of the CDMA system design as they are examined, simu lated, deployed and tested. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2000.

The radio wave propagation prediction is one of the key elements for designing an efficient radio network system. WRAP International has developed a software for spectrum management and radio network planning.This software includes some wave propagation models which are used to predict path loss. Current propagation models in WRAP perform the calculation in a vertical 2D plane, the plane between the transmitter and the receiver. The goal of this thesis is to investigate and implement a 3D wave propagation model, in a way that reflections and diffractions from the sides are taken into account.The implemented 3D wave propagation model should be both fast and accurate. A full 3D model which uses high resolution geographical data may be accurate, but it is inefficient in terms of memory usage and computational time. Based on the fact that in urban areas the strongest path between the receiver and the transmitter exists with no joint between vertical and horizontal diffractions [10], the radio wave propagation can be divided into two parts, the vertical and horizontal part. Calculations along the horizontal and vertical parts are performed independently, and after that, the results are combined. This approach leads to less computational complexity, faster calculation time, less memory usage, and still maintaining a good accuracy.The proposed model is implemented in C++ and speeded up using parallel programming techniques. Using the provided Stockholm high resolution geographical data, simulations are performed and results are compared with real measurements and other wave propagation models. In addition to the path loss calculation, the proposed model can also be used to estimate the channel power delay profile and the delay spread.

In spite of the remarkable development of modern medical treatment and technology, the threat of pandemic diseases such as anthrax, cholera, and SARS has not disappeared. As a part of emerging healthcare decision problems, many researchers have studied how to detect and contain disease outbreaks, and our research is aligned with this trend. This thesis mainly consists of two parts: epidemic simulation modeling for effective intervention strategies and spatiotemporal monitoring for outbreak detection. We developed a stochastic epidemic simulation model of a pandemic influenza virus (H1N1) to test possible interventions within a structured population. The possible interventions — such as vaccination, antiviral treatment, household prophylaxis, school closure and social distancing — are investigated in a large number of scenarios, including delays in vaccine delivery and low and moderate efficacy of the vaccine. Since timely and accurate detection of a disease outbreak is crucial in terms of preparation for emergencies in healthcare and biosurveillance, we suggest two spatiotemporal monitoring charts, namely, the SMCUSUM and RMCUSUM charts, to detect increases in the rate or count of disease incidents. Our research includes convenient methods to approximate the control limits of the charts. An analytical control limit approximation method for the SMCUSUM chart performs well under certain conditions on the data distribution and monitoring range. Another control limit approximation method for the RMCUSUM chart provides robust performance to various monitoring range, spatial correlation structures, and data distributions without intensive modeling of the underlying process.