Tourism, Barbados's primary industry, declined substantially from the outset of the 2008 global recession, triggering an economic slump in the local economy. The purpose of this exploratory study was to explore the views of 20 Barbadian tourism executives regarding the ability of community-based tourism (CBT) to resuscitate Barbados's tourism industry. The participants included 10 from the government and 10 from the business sector; all possessed knowledge of CBT and worked with tourism for at least 10 years. Arnstein's ladder of citizen participation constituted the conceptual framework of this study. Participants were recruited by snowball and purposive sampling. Data were collected using an interview guide with semistructured interview questions, an audio recorder, and interview notes. The collected data were coded and analyzed using thematic analysis, which involved collating the most cited codes into potential themes and developing thematic maps. The major themes that emerged from the data analysis of the private sector included the use of CBT as a means to solidify social relationships among locals and tourists and its ability to encourage repeat vacations. The major themes that materialized from interviewing the government workers included the need for the education of residents regarding the importance of their roles as stakeholder participants and the obligation by the relevant officials to stem any potential for criminal activity that could occur through CBT implementation. Repeated vacations through CBT could give rise to positive social change in the island by generating increased foreign currency injections and improving the social well-being of Barbadians and the Barbados economy.

Aescin is a mixture of several acidic triterpenoid saponin glycosides found in the extracts of the horse chestnut tree. Horse chestnut, Aesculus Hipoocastanum, is one of the 25 domestic species of Aesculus that are mostly large, ornamental shade trees. Although known to be poisonous, the nuts of the horse chestnut are used by Amerindians, after detoxification. Horse chestnuts are said to have several traditional medicinal usages including even cancer. In this study the biochemical, genotoxic, and cytotoxic effects of aescin was studied using isolated lymphocytes, whole blood lymphocytes and HL-60 promyeloid leukemia cell lines. Cytotoxicity of aescin was examined by trypan blue viability staining of the cells in culture treated with varying aescin concentrations. It was observed that aescin was cytotoxic at all concentrations, for all cell types studied, except whole blood lymphocytes, where it was not cytotoxic at 10-9 and 10-10 M concentrations. Genotoxicity of aescin was examined by sister chromatid exchange and micronucleus. The genotoxic effect of Aescin was observed to be more significant over isolated lymphocytes compared to other cell lines. On the otherhand, aescin at 10-8 M and lower concentrations were observed to be non-genotoxic over whole blood lymphocytes whereas this concentration was considerably toxic for isolated lymphocytes and for HL-60 cell lines. Apoptotic properties of aescin were determined by DNA fragmentation, cytochrome c release and negative NAPO staining. All the Aescin concentrations tested resulted in apoptosis over HL-60 cell lines, whereas necrosis was not observed. However, isolated lymphocytes showed both apoptosis and necrosis upon treatment with 10-6 M to 10-8 M aescin, exhibiting apoptosis only at 10-9 M and 10-10 M. Biochemical effects of aescin were investigated by following GST and NAT enzyme activities. An increase in GST enzyme activity was observed over all cell lines treated with increasing aescin concentrations for 72 hours. Whereas NAT activity was decreased upon treatment with aescin in similar manner.

Στην παρούσα Διπλωματική Εργασία μελετάται η δομή και τα χαρακτηριστικά ενός νέου μετατροπέα ψηφιακού σήματος σε αναλογικό (Digital to Analog Converter DAC). Η δομή του DAC βασίζεται στη γνωστή δομή του συμβατικού R2R Ladder και θα μπορούσε να θεωρηθεί σαν μία δισδιάστατη ανάπτυξη του Ladder. Αυτό σημαίνει ότι η νέα μορφή του DAC χρησιμοποιεί σαφώς περισσότερες αντιστάσεις από τον συμβατικό Ladder, όμως δίνεται η δυνατότητα της ρύθμισης του ρεύματος εξόδου του κάθε κλάδου. Αυτό έχει ως συνέπεια τη δραματική βελτίωση της γραμμικότητας του DAC. Επιπλέον στην Εργασία αυτή μελετήθηκαν με χρήση της θεωρίας των πιθανοτήτων τα χαρακτηριστικά του απλού Ladder και χρησιμοποιήθηκαν για την εξαγωγή συμπερασμάτων που αφορούν στη γραμμικότητα της νέας δομής Ladder. Τα θεωρητικά αποτελέσματα επιβεβαιώθηκαν με εξομοιώσεις. Τέλος, μία σχεδίαση σε φυσικό επίπεδο με την χρήση μόνο MOSFETS και CMOS τεχνολογίας (χωρίς την χρήση αντιστάσεων) σχεδιάσθηκε και εξομοιώθηκε στο Cadence ένας Ladder της νέας δομής. / This Diploma Thesis studies on a new Digital to Analog Converter (DAC) structure developed in the Applied Electronics Laboratory of the University of Patras. The new DAC structure is based on the simple R2R ladder combining several of them in a 2-dimentional grid. As result a high linearity DAC is derived after a simple calibration procedure. The Diploma Thesis presents results on probability of the simple R2R Ladder, employs these results so as to forecast the linearity of the 2-dimentional Ladder, whereas confirms theoretical results with simulations. Finally, a DAC based on the 2-dimentional topology has been designed and simulated using Cadence, in the framework of this Diploma Thesis.

Alla barn har enligt barnkonventionen rätten att tillåtas att fritt uttrycka sina åsikter. Därtill åligger det samhället ett ansvar att ta tillvara på de ungas engagemang och lyssna till deras synpunkter, idéer och förslag. Emellertid är det svårt att förverkliga ungas delaktighet i praktiken, då somliga ser barn som objekt i behov av skydd, ser andra barn som självständiga aktörer med rättigheter. Således utelämnas barn och ungdomar till enskilda vuxnas bemötande, vilket är otillräckligt för att fullt ut lyckas ta in barns åsikter och säkerställa deras rätt till deltagande. Den här undersökningen tog sin utgång ifrån tidigare forskning vilken har belyst ett behov av studier på ungdomars egna reflektioner över delaktighet i beslut som rör dem. Studien har lyft hur ungdomars perspektiv på delaktighet i samhället ser ut genom fyra frågeställningar. Den första handlar om ungdomars inställning till delaktighet, den andra om vilka samhällsintressen de vill påverka och den tredje handlar om vilka förutsättningar för delaktighet de önskar. Den fjärde frågeställningen besvaras utifrån resultatet från den första och tredje frågeställningen och handlar om i vilken utsträckning de vill vara med och påverka. En fallstudie i Jönköping har genomförts där åtta respondenter deltagit i individuella kvalitativa semi-strukturerade intervjuer. Resultatet bygger på en fenomenografisk analys av sammanställt datamaterial och analys av resultatet i jämförelse med Harts delaktighetstrappa. Resultatet visar bland annat att: ungdomarna upplevt att de blivit nedvärderade av vuxna, det mest förekommande intresseområdet för påverkan var skolan, de tycker delaktighet är viktigt och något som är allas rättighet och att de önskar att delaktigheten ska vara lättillgänglig och smidig att genomföra. I syfte att även sammanfatta ungdomars perspektiv på delaktighet genomfördes en analys i jämförelse med Harts delaktighetstrappa. Resultatet kunde således nå ett analytiskt djup och nå teorigenerering, då ungdomarna kategoriserades som tre olika idealtyper: de förnöjsamma, reformisterna och de revolutionära. Då syftet är att ge djupare förståelse för ungdomars livsvärld angående delaktighet, bör inte de analytiska konstruktionerna ses som renodlade och representativa för alla ungdomar. Istället bör resultatet främja förståelse för den dynamik som återfinns bland gruppen ungdomar. / According to the convention on the Rights of the Child, every child has the right to freely express his or her opinion. The society has a responsibility to include young people’s participation, hence listen to their opinions and ideas. Nevertheless, it is difficult to implement young people’s participation in practice as children are sometimes viewed as objects in need of protection and viewed by others as independent actors. Adults behavior affects the opportunities to participate and is therefore important to acknowledge. This essay is grounded in previous studies which have observed a need for further research on young people’s own perspective on participation. Consequently, the purpose was to examine youth’s perspective on partic-ipation in matters that concern them, just like article 12 claims. Four research questions have been answered. The first one concerns the youths point of views of participation, the second one their interest in matters revolving around youths in society and the third one concerns what prerequisites the youth’s need to be able and willing to participate. The fourth research question was to what extent young people want to influence issues that concern them. It was answered based on the results of the first and the third questions and is presented in the analysis. The questions have been studied within the case of Jönköping. Data was collected through individual semi-structured interviews with eight participants. With a phenomenographic method the collected data was analyzed. In addition, the data was linked to levels of children’s participation though Hart’s Ladder of Participation which gave the results an order of precedence along with analytical depth and developed a theory. In summary, the findings conclude: the adolescents had experienced that adults often show a degrading attitude towards youth; there is a great interest in questions involving their schools; partic-ipation is important to youth and is every individual’s right; and finally, societal participation needs to be further developed to become known and accessible for youth. It was further categorized into three different ideal types: the indifferent, the reformers and the revolutionary. The analytical constructions should not be viewed as complete and representative for all youths. Rather the result of this study should facilitate an understanding of the many dynamics of adolescents’ participation in society.

Over the last decades, several works have been devoted to the investigation of a new class of hybrid spin systems with nodal localized Ising spins and interstitial delocalized electrons. In a diamond-like geometry, this class of models depicts magnetization plateaus and an enhanced magnetocaloric effect. In square lattices geometry, the quantum correlations may lead to ferromagnetic or antiferromagnetic ordering depending on the filling fraction of the delocalized orbitals. In the present work, we study the magnetic and thermodynamic properties of a hybrid spin ladder consisting of Ising spins placed in distinct chains, interacting with each other through a ferromagnetic exchange coupling φ. The interaction between nearest neighbor’s localized spins on the same chain is mediated by a pair of interstitial electrons that may hop between chains with hopping amplitude t obeying Pauli’s Exclusion Principal. The exchange interaction between each localized spins and an interstitial electron is J. The interplay of hopping amplitude and exchange interaction may give rise to a rich phase diagram for the ground state of the system. Such a model may be exactly solvable by using decoration-iteration transformation, transfer matrix method and exact diagonalization. Our results show that quantum correlations betweeen delocalized spins induce an antiferromagnetic coupling between chains that competes with the ferromagnetic exchange coupling. A resulting kinecally-driven frustration is predominant in the regime of low temperatures and large hopping amplitudes. We provide the full ground-state phase diagram as well as the frustration diagram on distinct coupling regimes. The effect of an external magnetic field are also investigated. Further, we determine how the hopping amplitude and an external magnetic field affect different thermodynamics properties of the system, such as total magnetization, specific heat and magnetocaloric rate. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nas últimas décadas, vários trabalhos têm sido dedicados à investigação de uma nova classe de sistemas de spins híbridos, formados por spins de Ising nodais localizados e elétrons intersticiais delocalizados. Na geometria do tipo diamante, esta classe de modelos apresenta platô de magnetização e um efeito magnetocalórico pronunciado. Em uma geometria de rede quadrada, as correlações quânticas podem levar a um ordenamento ferromanético ou antiferremagnético dependendo da fração de preenchimento dos orbitais delocalizados. No presente trabalho, nós estudamos as propriedades magnéticas e termodinâmicas de escada de spins híbridos, consistindo em spins de Ising localizados em cadeias distintas, que interagem por meio de acoplamento ferromagnético de troca φ. A interação entre os primeiros vizinhos de spins localizados numa mesma cadeia é mediada por um par de elétrons intersticiais que podem saltar entre as cadeias com amplitude de hopping t, obedecendo ao Princípio de Exclusão de Pauli. A interação de troca entre os spins localizados e os spins intersticiais é J. A competição entre as interações de troca e a amplitude de hopping pode dar origem a um rico diagrama de fases para o estado fundamental do sistema. Este modelo pode ser exatamente solúvel usando a transformação de iteração-decoração, método da matriz de transferência e diagonalização exata. Nossos resultados mostram que as correlações quânticas entre os spins delocalizados induzem um acoplamento antiferromagnético entre as cadeias que compete com o acoplamento ferro-magnético de troca. Uma frustração induzida cineticamente é predominante no regime de baixas temperaturas e grandes amplitudes de hopping. Nós fornecemos um diagrama de fases completo para o estado fundamental do sistema, bem como o diagrama de frustração para diferentes regimes dos acoplamentos. Os efeitos de um campo magnético externo também são investigados. Além disso, nós determinamos como a amplitude de hopping e um campo magnético externo afetam diferentes propriedades termodinâmicas do sistema, tais como a magnetização total, o calor específico e a taxa magnetocalórica.

A transição energética residencial começou a receber especial atenção da comunidade científica nos anos 1970 e 1980, quando se acreditava na ocorrência iminente da Crise da Lenha. Na época, temia-se que o corrente ritmo de consumo de biomassas sólidas em países em desenvolvimento ultrapassaria a capacidade de produção primária dos ambientes naturais, com sérias consequências para as camadas menos abastadas da população destes locais, que se veriam em uma situação de escassez de fontes de energia. Apesar de esta crise nunca haver, de fato, se concretizado, a preocupação com a sua potencial ocorrência estimulou o desenvolvimento de modelos que visavam à interpretação do fenômeno da transição energética residencial decorrente do processo de urbanização e aumento de renda dos usuários finais. Tal interesse culminou na elaboração do modelo da Escada Energética que, de uma maneira geral, previa que o abandono de fontes de energia tradicionais e a adoção de fontes de energia modernas era o resultado do aumento do status social da população. Inicialmente, a Escada Energética se estabeleceu como principal modelo de transição energética residencial. À medida que novos estudos foram desenvolvidos, entretanto, evidências passaram a sugerir que diversos fatores envolvidos na transição energética em países em desenvolvimento não podiam ser explicados pelo modelo. Estas evidências subsidiaram a concepção do modelo do Acúmulo de Combustíveis, segundo o qual a diversificação, e não a substituição, de energéticos seria o resultado do desenvolvimento social da população. Atualmente, não existe consenso sobre qual modelo melhor reflete o fenômeno da transição energética residencial. Como consequência, políticas públicas de acesso a energia e serviços energéticos limpos baseadas nestas diferentes interpretações possuem características e resultados distintos. Neste contexto, o presente trabalho pretende contribuir para a discussão sobre qual modelo de transição energética melhor reflete a realidade dos consumidores residenciais de energia de países em desenvolvimento a partir da apresentação de dois estudos de caso que retratam diferentes facetas da questão. As análises elaboradas indicam que o modelo do Acúmulo de Combustíveis consegue representar com maior fidelidade o fenômeno da transição energética residencial e que políticas públicas estruturadas segundo seu arcabouço teórico podem contribuir mais eficazmente para a melhoria das condições de vida da população. / The residential energy transition began to receive special attention from the scientific community in 70s and 80s, when a Fuelwood crisis was believed to be imminent. At the time, it was feared that the current rhythm of solid biomass consumption would not keep pace with the primary productivity of the forests and other sources of fuelwood, with severe consequences striking the least wealthy households, who would face an energy shortage. Although the referred crisis never really happened, the concern with its potential occurrence stimulated the development of models aiming at interpreting the energy transition phenomenon provoked by the urbanization process and the increase in income of households. Such interest culminated in the elaboration of the Energy Ladder model, which indicated that the abandonment of traditional energy sources and the adoption of modern ones was the result of the increase of the social status of the population. Initially, the Energy Ladder established itself as the main residential energy transition model. As new studies were being developed, however, evidences suggesting that different factors related to the energy transition in developing countries couldnt be explained by the model were found. These evidences supported the conception of the Fuel Staking model, according to which diversification, instead of substitution, resulted from the social development of the population. Currently, there is no consensus on which model better represents the residential energy transition. As a consequence, public policies focused on clean energy and energy services access based on these different interpretations have different characteristics and results. In such context, this work intends to contribute to the discussion on which energy transition model better reflects the reality of households in developing countries by presenting two case studies showing different aspects of the thematic. The analysis presented suggests that the Fuel Stacking model can better represent the residential energy transition phenomenon and that public policies structured according to its theoretical framework are more effective in contributing to increase the living standards of the population.

This thesis deals with a description of three claims reserving methods - with stochastic models for Chain ladder, Bornhuetter/Ferguson and multiplicative method. There are mentioned their assumptions, parameter estimates, their properties and formulas for loss reserves in the first part. The second part of the text is devoted to formulas for the mean squared error of prediction and its estimate. Finally, a numerical example shows comparison of these methods.

Syftet med denna kvalitativa studie är att undersöka om metoden Signs-of-Safety kan öka barns delaktighet i barnutredningar gjorda av socialsekreterare. Frågeställningar är: - Hur reflekterar socialsekreterare som använder respektive inte använder Signs-of- Safety kring barns delaktighet i utredningar? Samt: - Varierar graden av delaktighet hos barn mellan utredningar där Signs-of-Safety används jämfört med utredningar där metoden inte används? Vi genomförde två stycken fokusgruppintervjuer med totalt tio socialsekreterare som arbetar med utredningar inom socialtjänsten, samt analyserade sju utredningar varav fyra var skrivna i en kommun som använde sig av Sign-of-Safety. De resterande tre utredningarna var skrivna i en kommun där de inte använde Signs-of-Safety. Teoretisk utgångspunkt var socialkonstruktivism. Det fanns en stor enighet bland socialsekreterarna om att det är viktigt att barn görs delaktiga. Analysen av både intervjuer och utredningar gjordes utifrån Harts delaktighetsstege samt socialkontruktivism och visade att metoden Signs-of-Safety inte verkade öka barns delaktighet, men att metoden tydliggjorde delaktigheten. / The purpose of this qualitative study was to get an insight in if the method Signs-of- Safety might improve childrens’ participation in investigations concerning themselves. Our research questions were; How do social workers who use or do not use Signs-of- Safety reflect on children's involvement in investigations? and; Is there accordingly to the social workers a variation in the degree of participation among children in investigations where Signs-of-Safety is used compared to investigations where the method is not used? Two focus group interviews in two different municipalities, one where Signs-of-Safety had been used and one where the method not had been used, were performed. The interviews and four written investigations i each work group were analysed by using Hart´s participation ladder and social constructivism. The result showed that all our informants regarded childrens’ participation as important. No differences in the degree of participation of the children could be identified.

A natural phenomenon characterized by dense aggregations of unicellular photosynthetic marine organisms has been termed colloquially as red tides because of the vivid discoloration of the water. The dinoflagellate Karenia brevis is the cause of the Florida red tide bloom. K. brevis produces the brevetoxins, a potent suite of neurotoxins responsible for substantial amounts of marine mammal and fish mortalities. When consumed by humans, the toxin causes Neurotoxic Shellfish Poisoning (NSP). The native function of brevetoxin within the organism has remained mysterious since its discovery. There is a need to identify factors which contribute to and regulate toxin production within K. brevis. These toxins are produced and retained within the cell implicating a significant cellular role for their presence. Localization of brevetoxin and identification of a native receptor may provide insight into its native role as well as other polyether ladder type toxins such as the ciguatoxins, maitotoxins, and yessotoxins. In higher organisms these polyether ladder molecules bind to transmembrane proteins with high affinity. We anticipated the native brevetoxin receptor would also be a transmembrane protein. Photoaffinity labeling has become increasingly popular for identifying ligand receptors. By attaching ligands to these photophors, one is able to activate the molecule after the ligand binds to its receptor to obtain a permanent linkage between the two. Subsequent purification provides the protein with the ligand directly attached. A molecule that is capable of fluorescence is a fluorophore, which upon excitation is capable of re-emitting light. Fluorescent labeling uses fluorophores by attaching them covalently to biologically active compounds. The synthesis of a brevetoxin photoaffinity probe and its application in identifying a native brevetoxin receptor will be described. The preparation of a fluorescent derivative of brevetoxin will be described and its use in localizing the toxin to an organelle within K. brevis. In addition, the general utility of a synthesized photoaffinity label with other toxins having similar functionality will be described. An alternative synthetic approach to a general photoaffinity label will also be discussed whose goal was to accelerate the preparation and improve the overall synthetic yields of a multifunctional label.

This master thesis deals with the design of a wastewater treatment plant, which will be controlled by a PLC. The theoretical part describes the types of wastewater and sewage systems that are important in the design of wastewater treatment plants. The thesis also describes programmable logic controllers, theirs programming languages, SCADA (Supervisory Control And Data Acquisition) systems and automation.The thesis also deals with theoretical description of wastewater treatment plants, their functions and security. Next part describes the design of the wastewater treatment plant. The last part of the thesis describes implementation of the wastewater treatment plant controlled by a PLC.