5,473 research outputs found

    Revisão taxonómica do género Calendula L. (Asteraceae - Calenduleae) na Península Ibérica e Marrocos

    Get PDF
    The genus Calendula L. (Asteraceae - Calenduleae) includes, depending on the author, 10 to 25 species, distributed mainly in the Mediterranean basin. The taxonomy of this genus is considered to be extremely difficult, due to a great morphological variability, doubtfull relevance of some of the characters used to distinguish its species (e.g. the life form: annual or perennial; the habit: erect or diffuse, shape of the leaves, indumentum, relative size of the capitula and colour of disc or ray florets, achene morphology), but also due to the hybridization and polyploidization. Despite the numerous studies that have been published, no agreement on the classification and characters used to discriminate between taxa has been reached. A taxonomic study of the genus Calendula was conducted for the Iberian Peninsula and Morocco, aiming at (1) access the morphological variability between and within taxa, (2) confirm the chromosome numbers, (3) increase the nuclear DNA content estimations, (4) re-evaluate taxa delimitations and circumscription, and (5) reassess, and redefine, the descriptions and characters useful to distinguish taxa. In order to achieve a satisfying taxonomic core, extensive fieldwork, detailed morphometric analysis, chorological, karyological and genome size studies were conducted. For the Iberian Peninsula, four species were recognized, including nine subspecies (between these two new subspecies were described). For Morocco, including some taxa from Algeria and Tunisia 13 species were recognized (two new species and a nomenclatural change), including 15 subspecies (among these eight new subspecies were described). To corroborate the results obtained and to evaluate the evolutionary relationships among taxa, phylogenetic studies using molecular methods, such as ITS, microsatellites or other molecular markers, should be used.O género Calendula L. (Asteraceae - Calenduleae) inclui, dependendo do autor, 10 a 25 espécies, distribuídas essencialmente na bacia do Mediterrâneo. A taxonomia deste género é considerada extremamente difícil, devido à grande variabilidade morfológica, discutivel relevância de alguns dos caracteres utilizados para distinguir suas espécies (por exemplo, a forma de vida: anual ou perene, o hábito: erecto ou difuso, a forma das folhas, o indumento, o tamanho e a cor dos capítulos e a morfologia dos aquénios), mas também devido à hibridização e poliploidização. Apesar dos inúmeros estudos que foram publicados, não foi alcançado um acordo sobre a classificação e os caracteres utilizados para discriminar as suas espécies. Um estudo taxonómico do género Calendula foi realizado para a Península Ibérica e Marrocos, com o objectivo de (1) verificar a variabilidade morfológica, (2) confirmar o número de cromossomas, (3) aumentar as estimativas de conteúdo em ADN, (4) reavaliar a delimitação e a circunscrição dos taxa, e (5) reavaliar e redefinir as descrições e caracteres úteis para os distinguir. Para alcançar uma robustês taxonómica satisfatória, foram realizados extensos trabalhos de campo, análise morfométrica detalhada, abordagens corológicas, cariológicas e quanto ao conteúdo em ADN. Para a Península Ibérica, quatro espécies foram reconhecidas, incluindo nove subespécies (entre essas duas novas subespécies foram descritas). Para Marrocos, incluindo alguns taxa da Argelia e Tunisia, foram reconhecidas 13 espécies (duas novas e uma mudança nomenclatural), incluindo 15 subespécies (entre essas oito novas subespécies foram descritas). Para corroborar os resultados obtidos e avaliar as relações evolutivas e filogenéticas entre os taxa, estudos que utilizem diferentes métodos moleculares, tais como ITS, microsatélites ou outros marcadores moleculares, devem ser utilizados.Apoio financeiro do Laboratório Associado CESAM - Centro de Estudos do Ambiente e do Mar (AMB/50017) financiado por fundos nacionais através da FCT/MCTES e cofinanciado pelo FEDER (POCI-01-0145-FEDER-007638), no âmbito do Acordo de Parceria PT2020, e Compete 2020Programa Doutoral em Biologi

    Forested buffers in agricultural landscapes : mitigation effects on stream–riparian meta-ecosystems

    Get PDF
    Stream–riparian meta-ecosystems are strongly connected through exchanges of energy, material and organisms. Land use can disrupt ecological connectivity by affecting community composition directly and/or indirectly by altering the instream and riparian habitats that support biological structure and function. Although forested riparian buffers are increasingly used as a management intervention, our understanding of their effects on the functioning of stream–riparian metaecosystems is limited. This study assessed patterns in the longitudinal and lateral profiles of streams in modified landscapes across Europe and Sweden using a pairedreach approach, with upstream unbuffered reaches lacking woody riparian vegetation and with downstream reaches having well-developed forested buffers. The presence of buffers was positively associated with stream ecological status as well as important attributes, which included instream shading and the provision of suitable habitats for instream and riparian communities, thus supporting more aquatic insects (especially EPT taxa). Emergence of aquatic insects is particularly important because they mediate reciprocal flows of subsidies into terrestrial systems. Results of fatty acid analysis and prey DNA from spiders further supported the importance of buffers in providing more aquatic-derived quality food (i.e. essential fatty acids) for riparian spiders. Findings presented in this thesis show that buffers contribute to the strengthening of cross-ecosystem connectivity and have the potential to affect a wide range of consumers in modified landscapes

    Cost-effective non-destructive testing of biomedical components fabricated using additive manufacturing

    Get PDF
    Biocompatible titanium-alloys can be used to fabricate patient-specific medical components using additive manufacturing (AM). These novel components have the potential to improve clinical outcomes in various medical scenarios. However, AM introduces stability and repeatability concerns, which are potential roadblocks for its widespread use in the medical sector. Micro-CT imaging for non-destructive testing (NDT) is an effective solution for post-manufacturing quality control of these components. Unfortunately, current micro-CT NDT scanners require expensive infrastructure and hardware, which translates into prohibitively expensive routine NDT. Furthermore, the limited dynamic-range of these scanners can cause severe image artifacts that may compromise the diagnostic value of the non-destructive test. Finally, the cone-beam geometry of these scanners makes them susceptible to the adverse effects of scattered radiation, which is another source of artifacts in micro-CT imaging. In this work, we describe the design, fabrication, and implementation of a dedicated, cost-effective micro-CT scanner for NDT of AM-fabricated biomedical components. Our scanner reduces the limitations of costly image-based NDT by optimizing the scanner\u27s geometry and the image acquisition hardware (i.e., X-ray source and detector). Additionally, we describe two novel techniques to reduce image artifacts caused by photon-starvation and scatter radiation in cone-beam micro-CT imaging. Our cost-effective scanner was designed to match the image requirements of medium-size titanium-alloy medical components. We optimized the image acquisition hardware by using an 80 kVp low-cost portable X-ray unit and developing a low-cost lens-coupled X-ray detector. Image artifacts caused by photon-starvation were reduced by implementing dual-exposure high-dynamic-range radiography. For scatter mitigation, we describe the design, manufacturing, and testing of a large-area, highly-focused, two-dimensional, anti-scatter grid. Our results demonstrate that cost-effective NDT using low-cost equipment is feasible for medium-sized, titanium-alloy, AM-fabricated medical components. Our proposed high-dynamic-range strategy improved by 37% the penetration capabilities of an 80 kVp micro-CT imaging system for a total x-ray path length of 19.8 mm. Finally, our novel anti-scatter grid provided a 65% improvement in CT number accuracy and a 48% improvement in low-contrast visualization. Our proposed cost-effective scanner and artifact reduction strategies have the potential to improve patient care by accelerating the widespread use of patient-specific, bio-compatible, AM-manufactured, medical components

    Political Islam and grassroots activism in Turkey : a study of the pro-Islamist Virtue Party's grassroots activists and their affects on the electoral outcomes

    Get PDF
    This thesis presents an analysis of the spectacular rise of political Islam in Turkey. It has two aims: first to understand the underlying causes of the rise of the Welfare Party which -later became the Virtue Party- throughout the 1990s, and second to analyse how grassroots activism influenced this process. The thesis reviews the previous literature on the Islamic fundamentalist movements, political parties, political party systems and concentrates on the local party organisations and their effects on the party's electoral performance. It questions the categorisation of Islamic fundamentalism as an appropriate label for this movement. An exploration of such movements is particularly important in light of the event of 11`x' September. After exploring existing theoretical and case studies into political Islam and party activism, I present my qualitative case study. I have used ethnographic methodology and done participatory observations among grassroots activists in Ankara's two sub-districts covering 105 neighbourhoods. I examined the Turkish party system and the reasons for its collapse. It was observed that as a result of party fragmentation, electoral volatility and organisational decline and decline in the party identification among the citizens the Turkish party system has declined. However, the WP/VP profited from this trend enormously and emerged as the main beneficiary of this process. Empirical data is analysed in four chapters, dealing with the different aspects of the Virtue Party's local organisations and grassroots activists. They deal with change and continuity in the party, the patterns of participation, the routes and motives for becoming a party activist, the profile of party activists and the local party organisations. I explore what they do and how they do it. The analysis reveals that the categorisation of Islamic fundamentalism is misplaced and the rise of political Islam in Turkey cannot be explained as religious revivalism or the rise of Islamic fundamentalism. It is a political force that drives its strength from the urban poor which has been harshly affected by the IMF directed neoliberal economy policies. In conclusion, it is shown that the WP/VP's electoral chances were significantly improved by its very efficient and effective party organisations and highly committed grassroots activists

    Excess foundry sand characterization and experimental investigation in controlled low-strength material and hot-mixing asphalt

    Get PDF
    This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.Structural Engineerin

    デジタルデザイン教育における中国の伝統的パターン要素の統合発展に関する研究

    Get PDF
    Cultural dissemination and artistic heritage represent a highly concentrated database of information in the past, which depends not only on the expansion of emerging digital media but also on the transformation of language and knowledge. Digital design with traditional patterns as elements is a continuous process from creative generation, material selection, and model establishment. The whole process is done based on the digital design course. The author conducts research from three aspects: theoretical knowledge, course operation exercises and after-school questionnaires, which is a process of integrating technology and art. The purpose of this course is not to discover new theories or new technologies, but to provide morphological possibilities for cultural symbols under existing digital technologies. The purpose is to try to construct new ideas and innovative digital technologies for traditional Chinese patterns, to find Possible paths for the inheritance of new traditional culture.北九州市立大

    Description assistée d'un environnement intelligent en réalité augmentée

    Get PDF
    Les technologies d'assistance modernes offrent d'augmenter, de maintenir ou d'améliorer les capacités fonctionnelles d'une personne avec incapacités. Parmi ces technologies, les environnements intelligents favorisent effectivement le maintien à domicile des personnes âgées. Pourtant, les taux d'abandon des technologies d'assistance sont aujourd'hui élevés. L'absence d'inclusion de l'utilisateur dans la construction et la personnalisation de ces technologies est fortement pointée du doigt par la littérature. Un système fait soi-même (Do-it-Yourself) centré sur le partage et où l'utilisateur conçoit lui-même son assistance est donc à privilégier. Cette thèse s'intéresse à développer les interactions entre l'humain et l'intelligence artificielle pour la description assistée d'environnements intelligents personnalisés selon les habitudes du résident. Le but est de déterminer les interfaces et le langage à adopter pour favoriser l'échange entre un descripteur humain, expert des besoins du résident, et une intelligence artificielle, experte des environnements intelligents. Les habitudes que le descripteur doit transmettre au système d'assistance sont spatialisées par définition, elles prennent place à des endroits spécifiques de l'environnement, avec des objets spécifiques de cet environnement et à des moments précis. La réalité augmentée s'inscrit ainsi parfaitement dans cette approche puisqu'elle permet d'ancrer dans le monde réel les éléments virtuels représentant l'environnement et les habitudes dans celui-ci. Les habitudes que le descripteur détaille sont également spécifiques à la façon de faire du résident tandis que les connaissances des environnements intelligents de l'intelligence artificielle proposée sont davantage génériques. Aussi, un langage compréhensible par l'humain et assez puissant pour représenter à la fois ces concepts spécifiques et génériques est nécessaire. Les ontologies, base de données sémantiques, répondent à ces besoins grâce à leur représentation textuelle et au raisonnement ontologique qui permet de définir le niveau d'abstraction adéquat pour l'échange. En combinant la réalité augmentée à la sémantique, le conseiller virtuel de description assistée des environnements intelligents présenté dans cette thèse accompagne le descripteur dans la spécification des habitudes du résident. De plus, en agrégeant l'expérience acquise avec l'ensemble des descriptions précédentes, ce conseiller fournit des conseils en temps-réel pour favoriser l'idéation. Ce conseiller virtuel a été testé auprès d'experts et de proches aidants. Les résultats obtenus confirment que le conseiller virtuel proposé permet la description de l'environnement et des activités, notamment grâce à ses interactions intuitives et naturelles. Les habitudes numérisées avec le conseiller virtuel pourraient à terme permettre à l'environnement intelligent de mieux comprendre les besoins de son résident et de s'y adapter

    Seismic Analysis and Assessment of Historic Unreinforced Masonry Structures

    Get PDF
    This thesis is targeted towards understanding the behaviour of unreinforced masonry structures (URM) under lateral loads that simulate earthquake effects, as well what aspects of their composition affects their behaviour. Masonry is a composite material containing bricks and mortar. In assessment of existing masonry construction uncertainties prevail regarding the homogenized material mechanical properties, which affect the estimated demands on structural masonry components and their corresponding resistances. To understand these effects, a series of nonlinear finite element parametric studies were conducted studying critical factors involved in the makeup of masonry. In addition, studies were conducted on the effectiveness of empirical equations in estimating the mechanical properties of masonry. The final aspect was three-dimensional finite element modelling of a scale URM structure that had been tested on a shake table. The findings of this study are crucial in determining the vulnerability of URM structures which include heritage construction to seismic hazards
    corecore