Sea turtles face many threats to their populations globally. Loggerhead sea turtles (Caretta caretta) and green sea turtles (Chelonia mydas) are listed by the International Union for the Conservation of Nature Red List as Endangered. In Florida, loggerhead and green sea turtles nest along the coastline during April-September. Mechanical beach cleaning is an aesthetic service performed daily on some beaches in Florida to clean the wrack line and/or the entire beach of debris. Alterations made to beaches by methods such as mechanical beach cleaning have the potential to impact sea turtle nesting, hatching, and emergence success. Generalized linear mixed models were performed to investigate the impacts of mechanical beach cleaning on nesting, hatching and emergence success of loggerhead and green turtles from 1997-2015 in Broward County, Florida. The results showed mechanical beach cleaning had an effect on nesting success, however, hatching and emergence success were not affected by mechanical beach cleaning. These results indicate that mechanical beach cleaning cannot solely be used to determine sea turtle management or conservation guidelines in Broward County.

Depuis des années, on observe un déclin des insectes pollinisateurs. La perte d’habitats naturels, en partie liée àl’urbanisation, est considérée comme l’une des causes majeures de ce déclin. Des populations d’abeilles(Hymenoptera : Anthophila) se maintiennent cependant en milieux urbains. La structure de leurs communautés,ainsi que leurs comportements de butinage et de nidification peuvent être affectés par les perturbations liées àl’urbanisation. Notre objectif était d’évaluer l’ampleur de ces modifications et de comprendre leurs mécanismes enutilisant 24 sites dans le Grand Lyon localisés selon un gradient d’urbanisation croissante (mesurée par laproportion de surfaces imperméables). Nous avons analysé les réseaux d’interactions pour étudier les relationsflore-abeilles et nous avons mis en place des aménagements pour la nidification (carrés de sol et hôtels à abeilles)sur 16 sites urbains ou périurbains pour étudier la dynamique de nidification et son impact sur les populations.Nous avons capturé 16352 spécimens appartenant à 293 espèces, soit près du tiers de la faune françaised’abeilles. Les sites périurbains (avec environ 50% de surface imperméable) avaient la plus grande richessespécifique. Les abeilles à langue longue et les abeilles cavicoles étaient plus présentes dans les milieux urbanisés,mais la spécialisation des interactions plantes-abeilles est restée stable le long du gradient d’urbanisation. Ladiversité spécifique des abeilles était associée de façon positive avec la diversité florale, la durée de floraison desespèces végétales et/ou leur floribondité. Les communautés d’abeilles étaient dépendantes de ces trois facteurs etaussi des plantes spontanées (natives ou naturalisées) plus que des plantes horticoles (ornementales ou exotiques).Enfin, les aménagements pour la nidification ont été colonisés par une faune d’abeilles diversifiée. Hormis Osmiabicornis, les abeilles ne présentaient aucune préférence quant aux substrats dans lesquels elles nidifiaient. Même sil’urbanisation change la structure des communautés d’abeilles, nos résultats confirment qu’une diversité importanted’abeilles sauvages peut perdurer dans des milieux moyennement, mais aussi fortement urbanisés.Dans un contexte d’urbanisation croissante et de déclin des abeilles, il semble indispensable de mettre en placedes plans de gestion en faveur de ces insectes pollinisateurs sauvages en agissant sur l’étendue des surfaces fleuries,les continuités écologiques entre ces surfaces, et une gestion plus appropriée des parcs, jardins et espaces vertsurbains. La présence d’une grande diversité d’espèces y compris dans des milieux très anthropisés fait vraiment desabeilles un groupe phare pour sensibiliser les citoyens à la biodiversité et aux services écosystémiques / Evidence has been accumulating for years that pollinator populations are declining. The loss of natural habitats,in part linked to urbanization, is considered to be one of the major causes of this decline. Some bee populationspersist nevertheless in urban environments. The structure of their communities, as well as their foraging and nestingbehaviors can be affected by urbanization. Our objective was to assess the magnitude of these changes and tounderstand their mechanisms by using 24 sites located in the Grand Lyon along a gradient of urbanization(measured by the proportion of impervious surface). We analyzed interaction networks to investigate plant-beerelations, and man-made nesting structures on urban sites (squares of soil and bee hotels) to study nesting dynamicsand its relevance for bee populations.We collected 16,352 specimens belonging to 293 species. Periurban environments (i.e., with ca. 50% ofimpervious surface) had the greatest diversity of bees. Long-tongued bees and cavity nesting bees were moreprevalent in urban environments, but the specialization of plant-bee interactions remained stable along the gradientof urbanization. The species richness of the bee community was positively associated with floral diversity, theduration of flowering of plant species and/or their floribundity. Bee communities depended on these three factorsand also spontaneous (native and naturalized) plant species more than on horticultural plants (ornamentals andexotics). Finally, man-made nesting sites were colonized by a diverse bee fauna. Apart from Osmia bicornis, beesshowed no preference for the substrates in which they nested. Our work confirms that, even if urbanization changesthe structure of the bee communities, an important diversity of bee species can persist in periurban, but also urbanenvironments.In a context of increasing urbanization and declining bee populations, it appears essential to create managementplans for these wild pollinators by acting on the surface of flowering areas, the ecological network linking them,and the appropriate management of parks, gardens, and recreational areas. The presence of a diverse array of beespecies even in the most urbanized area makes these pollinators worthy of being a flagship group to raise theawareness of citizens about biodiversity and ecosystemic services

Problemas de corte e empacotamento de itens irregulares são problemas que visam determinar um leiaute ótimo de objetos pequenos dentro de objetos maiores, a fim de atender a uma demanda. Estes problemas têm grande importância prática, já que surgem em vários tipos de indústria (como a têxtil, a de móveis e a de calçados). O problema estudado neste trabalho é o problema de corte de itens irregulares em recipientes. Os recipientes são delimitados e o objetivo é encontrar um leiaute dos objetos menores, sem sobreposição, dentro dos objetos maiores utilizando a menor quantidade de recipientes. Propomos um novo método de resolução para o problema. Nosso método é um algoritmo que gerencia um conjunto de heurísticas, de baixo nível, específicas para a resolução do problema com recipientes retangulares e irregulares. Recipientes irregulares são polígonos convexos e não convexos, que podem ser furados. As heurísticas desenvolvidas utilizam uma malha de pontos sobre a técnica de no-fit polygon para evitar a sobreposição dos itens e encontrar posições viáveis no recipiente retangular ou irregular. Os experimentos computacionais foram feitos para um grande conjunto de instâncias, de recipientes retangulares e irregulares. Os resultados demonstram a competitividade do método, que obtêm resultados bons e algumas soluções ótimas, em um tempo computacional aceitável. / Cutting and packing of irregular items are problems that aim to determine the optimum layout of small objects within larger objects (that we call bins), in order to meet a demand. These problems have great practical importance, since they emerge in various types of industry (such as textile, furniture and shoemaking). The problem studied in this work is the irregular bin packing problem. The bins are enclosed and the goal is to find a layout of items, without overlap, within the bins by using the minimum quantity of them. We propose a new method of resolution to this problem. Our method is an algorithm that manages a set of low-level heuristics, specific to solve the problem with rectangular bins and irregular bins. Irregular bins are convex and non-convex polygons, which may contain holes. The developed heuristics uses a mesh of points and the technique of no-fit polygon to avoid the overlapping of items and find feasible positions in rectangular or irregular bins. The computational experiments were performed for a large set of instances, using both rectangular and irregular bins. The results demonstrate the competitiveness of the method, which can get good results and some optimal solutions within an acceptable computational time.

Tato práce si klade za cíl obeznámit čtenáře s 2D CNC obráběním a rozličnými metodami popisu a manipulace s dvojrozměrnými objekty. Poté je představen tzv. Nesting problém a jsou popsány různé metody přístupu k jeho vyřešení. Praktická část pokrývá implementaci vlastního nesting softwaru, jenž je schopný efektivně rozmístit nepravidelné tvary do nepravidelné ohraničené plochy. Na závěr je provedeno zhodnocení řečeného softwaru a také je zmíněno jeho možné využití v praxi.

MENVSC (Geography) / Department of Geography and Geo-Information Sciences / Rainfall is undoubtedly the most significant factor for life’s continuity. South Africa is prone to future climate uncertainties due to global climate change. The aim of this study is to investigate rainfall variability and change in South Africa on a present day (1976-2005), near-future (2006-2035) and far-future (2036-2065) climate. For the study, 3 RCMs (REMO2009, RCA4 and CCLM4-8-17), forming part of CORDEX-Africa project were nested within 5 different CIMP5_GCMs of low resolution. GPCC precipitation, NOAA GHCN_CAMS Land Temperature and other NCEP reanalysis products were useful in validating models in simulations of present-day climate. RCP4.5 and RCP8.5 emission scenarios from IPCC-AR5 were used for future climate projections. On the validation, each regional climate model displayed different signature on simulations, rainfall in particular because this is a variable that is affected most by sub-grid process. Simulations nested within MIROC5 simulated more precipitation than simulations forced with other GCMs, due to more large-scale moisture convergence into the nested domain. There were differences in projections of RCM nested within the same GCM, as well as with the same RCM nested within different GCMs, on the future. Models nested within MPI project wetter conditions over the eastern parts of Limpopo, while the other two projected drier conditions in the same area. REMO2009 forced on MPI uniquely projected drying of Western Cape throughout the seasons on both RCPs and futures. Simulations conducted with the RCP8.5 scenario forcing are generally found to be associated with either a larger increase in temperature, or an increase in area associated with higher temperature increases. CCLM4-8-17 forced on HadGEM2 projected below average temperatures over the northwest parts of the country under the RCP8.5 scenarios. MPI driving model projected a general reduction of evaporation values, with lowest over northeast, northwest parts and south coastal parts of South Africa, in contrary to adjacent oceans. In this study, we have sought to identify the sources of uncertainties amongst model simulations between either the RCMs or the driving GCMs. / NRF

Short breeding period and harsh climatic conditions are major limiting factors to which birds have to adapt in northern tundra regions. Despite this fact, dozen species of birds annually migrate into these regions to increase their chances to breed successfully. My diploma thesis focuses on incubation behaviour of the Arctic tern (Sterna paradisaea). The research for my thesis took place on the Norwegian archipelago Svalbard, in two particular locations: Adolfbukta and Longyearbyen. By using the method of continuous video recording, I described incubation behaviour of this specie in detail. Human activity is very different on each of Adolfbukta and Longyearbyen. On site Adolfbukta study was conducted during seasons 2012 and 2014, both with different predation pressure. Having known that, I could evaluate the impact of human activity as well as the impact of different predation pressure on incubation behaviour and breeding ecology of Arctic tern. The presence of human close to the colony had significant effect on incubation behaviour. Due to higher disturbances, incubating birds tended to leave their nests more often, attention paid to the nest was smaller and calm incubation (sleeping on the nest) was shorter by a half. Human activity had no effect on other displays such as average clutch size or...

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