Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-02-29T22:35:01Z No. of bitstreams: 1 Disserta?ao Silvia.pdf: 886694 bytes, checksum: 049402a0d6acf81a0e49439f59de35f9 (MD5) / Made available in DSpace on 2016-02-29T22:35:01Z (GMT). No. of bitstreams: 1 Disserta?ao Silvia.pdf: 886694 bytes, checksum: 049402a0d6acf81a0e49439f59de35f9 (MD5) Previous issue date: 2013-04-18 / Convolvulaceae flowers are characterized mainly by being beautiful and ephemeral, attracting many visitor flowers that belong to different taxonomic groups. They are often found in open environments acting as an important food resource to flower visitors especially bees. This work aimed to investigate the interactions between insects and flowers of Jacquemontia bracteosa Meisn visitors (Convolvulaceae) identifying the pollinator potentials in a semi-arid area in the Northeast. The study was carried out from November 2011 to October 2012, when the morphology and floral biology and reproductive biology of J. bracteosa and floral visitors. The J. bracteosa flowers opened early morning and lasted less than 12 hours, being considered ephemeral. These were self-compatible breeding system, with fruiting by selfing and outcrossing. The flowers were visited mainly by Apidae family bees (females and males of Ancyloscelis apiformis, Ceratina aff maculifrons and Trigona spinipes) and family Halictidae (Augochlora spp). Other visitors were collected from flowers with its frequency below 1%. Among the floral visitors A. apiformis was considered the most efficient pollinator for showing behavior, frequency, and constancy on the flowers. Furthermore, these bees arrived soon when the flowers began to open and presented 90% of efficiency in tests with three visited flowers of J. bracteosa. Other bees as T. spinipes, Ceratina aff maculifrons, Exomalopsis analis, Exomalopsis sp1, and Pseudaugochlora sp1 may be considered potential pollinators because they present behavior and morphology compatible with the flowers. / Flores de Convolvulaceae s?o caracterizadas principalmente por serem ef?meras e vistosas, atraindo muitos visitantes florais pertencentes a grupos taxon?micos diferentes. S?o frequentemente encontradas em ambientes abertos atuando como importante fonte de recursos alimentares aos visitantes florais especialmente abelhas. O presente trabalho teve como objetivo estudar as intera??es entre os insetos visitantes e Jacquemontia bracteosa Meisn. (Convolvulaceae), identificando os potenciais polinizadores em uma ?rea no semi-?rido do Nordeste do Brasil. O estudo foi realizado de novembro de 2011 a outubro de 2012, e foram analisados aspectos da morfologia e biologia floral e biologia reprodutiva de J. bracteosa e dos visitantes florais. As flores de J. bracteosa abriam entre 5:10 e 6:20 e duravam menos de 12 horas, sendo consideradas ef?meras. Estas apresentavam sistema reprodutivo autocompat?vel, com frutifica??o por poliniza??o cruzada e autopoliniza??o. As flores foram visitadas principalmente por abelhas das fam?lias Apidae (f?meas e machos de Ancyloscelis apiformis, Ceratina aff maculifrons, Exomalopsis analis, Exomalopsis sp1 e Trigona spinipes) e Halictidae (Augochlora spp). Outros visitantes foram coletados nas flores apresentando frequ?ncia abaixo de 1%. Dentre os visitantes florais A. apiformis foi considerada o polinizador mais eficiente por apresentar comportamento compat?vel com a poliniza??o na esp?cie, frequ?ncia alta de visitas e const?ncia nas flores. Al?m disso, estas abelhas chegavam logo quando a flor come?ava a abrir e apresentaram 90% de efici?ncia nos testes realizados com tr?s visitas nas flores de J. bracteosa. Outras abelhas como T. spinipes, Ceratina aff maculifrons, Exomalopsis analis, Exomalopsis sp1 e Pseudaugochlora sp1 podem ser consideradas polinizadores potenciais, pois apresentam comportamento e morfologia compat?veis com a poliniza??o das flores.

<p>Medonosna pčela (Apis mellifera&nbsp; Linnaeus, 1758) je &scaron;iroko rasprostranjena vrsta iz grupe socijalnih insekata, glavni opra&scaron;ivač mnogih divljih biljaka i poljoprivrednih kultura. Pored njene primarne uloge u opra&scaron;ivanju, koristi se i za dobijanje pčelinjih proizvoda, pre svega meda, voska&nbsp; i propolisa,&nbsp; čime se dodatno nagla&scaron;ava njen privredni značaj. Uzimajući u obzir značaj medonosne pčele, a sa druge strane aktuelan problem pada broja kolonija, postoji potreba za razumevanje uzroka&nbsp; i&nbsp; procenu&nbsp; rizika koji leže u osnovi ovog kompleksnog problema. Stoga, istraživanja u ovoj doktorskoj disertaciji obuhvataju praćenje biohemijskih i fiziolo&scaron;kih parametara kod medonosne pčele kao pokazatelja stanja pčelinjih zajednica tokom letnjeg i zimskog perioda&nbsp; na stani&scaron;tima sa različitim antropogenim uticajem.&nbsp; U prvoj fazi istraživanja su izvedeni akutni laboratorijski testovi izlaganja&nbsp; medonosne pčele&nbsp; subletalnim dozama pesticida, tiakloprida i klotianidina, a dobijeni rezultati su&nbsp; ukazali&nbsp; na naru&scaron;enu neurotransmisiju, na izmene u aktivnosti antioksidativnih enzima i redoks statusa u ćeliji, kao i na imunosupresiju.&nbsp; U drugoj fazi istraživanja su analizirane kolonije&nbsp; medonosne pčele sa različitih lokaliteta&nbsp; na području AP Vojvodine, sa primenom stacionarnog i migratornog tipa pčelarenja, tokom letnjeg i zimskog perioda, a dobijeni rezultati su ukazali&nbsp; na značajne razlike&nbsp; u biohemijskom odgovoru medonosne pčele u zavisnosti od starosti pčela, sezone godine i tipa pčelinjaka. Na osnovu rezultata prethodne dve faze istraživanja, izvr&scaron;en&nbsp; je&nbsp; odabir uzoraka, kao i izbor parametara za&nbsp; treću fazu&nbsp; istraživanja,&nbsp; gde&nbsp; je praćeno stanje medonosne pčele&nbsp; iz stacionalnih pčelinjih zajednica, tokom letnjeg&nbsp; aktivnog perioda, kao i početkom&nbsp; i&nbsp; krajem&nbsp; zimskog perioda&nbsp; mirovanja pčela, sa tri lokaliteta u Republici Srbiji sa različitim stepenom urbanizacije i industrijalizacije: Beograd kao urbano, Susek kao ruralno i Zajača kao industrijsko područje. Dobijeni rezultati su ukazali na&nbsp; značajne razlike u zavisnosti od sezone&nbsp; godine, kao i&nbsp; lokaliteta sa različitim antropogenim uticajem.&nbsp; Zimske pčele, krajem perioda mirovanja&nbsp; u odnosu na početak mirovanja,&nbsp; karakteri&scaron;e vi&scaron;i&nbsp; nivo antioksidativne za&scaron;tite, udružen sa&nbsp; visokim&nbsp; stepenom&nbsp; oksidativnih o&scaron;tećenja, zatim&nbsp; bolja imunokompetencija, kao i niske energetske rezerve u masnom telu.&nbsp; Sezonskim povećanjem temperatura tokom godine povećava se sadržaj zasićenih, dok se smanjuje udeo nezasićenih masnih kiselina, gde se oleinska 18:1(9) kiselina izdvaja kao dominantna komponenta u ukupnom sadržaju masnih kiselina masnog tela&nbsp; pčela&nbsp; sa sve tri lokacije, tokom sva tri perioda.&nbsp; Niži nivo ukupnih ugljovodonika je jo&scaron; jedna fiziolo&scaron;ka karakteristika zimskih pčela. Takođe, zapažene su promene&nbsp; i&nbsp; u neurotransmisiji holinergičkog tipa tokom sezone, sa vi&scaron;im aktivnostima acetilholinesteraze kod pčela krajem zime i tokom leta.&nbsp; Metabolomičkom analizom hemolimfe pčela je&nbsp; identifikovano&nbsp; 125 metabolita, uključenih u 36 metaboličkih puteva, gde se kao biomarkeri od značaja za razlikovanje letnjih i zimskih pčela izdvajaju&nbsp; metaboliti u metabolizmu glicerolipida i aminokiseline glicin, cistein, glutamin, fenilalanin, prolin i lizin.&nbsp; Poređenjem dobijenih rezultata između različitih lokaliteta,&nbsp; pčele iz Beograda se izdvajaju sa nižim nivoom oksidativnog stresa,&nbsp; nižim aktivnostimaacetilholinesteraze, kao i fenol oksidaze i glukoza oksidaze, ključnih enzima u imunom odgovoru pčela. Pčele iz Suseka su se izdvojile sa najvećom masom masnog tela, &scaron;to ukazuje na dobre nutritivne i energetske rezerve u pčelama tokom zime i leta, dok se Beograd izdvaja sa značajno vi&scaron;im udelom nezasićenih masnih kiselina&nbsp; u masnom telu pčela.&nbsp; Takođe su zabeležene razlike u relativnoj zastupljenosti&nbsp; n-alkana u pčelama sa različitih lokaliteta, te je u Beogradu najzastupljeniji nonakozan&nbsp; (C29), dok je heptakozan (C27) najzastupljeniji u uzorcima pčela iz Suseka i Zajače.&nbsp; Analizom sadržaja metala u pčelama, pergi i medu, zapažamo da svaku sredinu karakteri&scaron;e specifičan profil zagađenja,&nbsp; kao i da je u medu znatno niža koncentracija svih analiziranih metala.&nbsp; Dobijeni rezultati pružaju dobru osnovu za dalja ispitivanja biolo&scaron;kog odgovora medonosne pčele, u pogledu uticaja faktora okruženja, a time i dalje definisanje odgovarajućih mera za&scaron;tite pčelinjih zajednica.</p> / <p>The&nbsp; honey&nbsp; bee&nbsp; (Apis&nbsp; mellifera&nbsp; Linnaeus,&nbsp; 1758)&nbsp; is&nbsp; a&sbquo;widespread&nbsp; social&nbsp; insect&nbsp; species&nbsp; and&nbsp; the&nbsp; main pollinator of various wild plants and agricultural crops.In addition to its primary role in pollination, the honey bee&nbsp; is&nbsp; also&nbsp; used&nbsp; for&nbsp; obtaining&nbsp; honeybee&nbsp; products, mostly honey, wax, and propolis, with a significant role in&nbsp; the&nbsp; economy.&nbsp; Number&nbsp; of&nbsp; honey&nbsp; bee&nbsp; colonies&nbsp; is declining,&nbsp; thus&nbsp; necessitating&nbsp; the&nbsp; assessment&nbsp; of underlying&nbsp; reasons&nbsp; and&nbsp; risks.&nbsp; Therefore,&nbsp; in&nbsp; this doctoral&nbsp; dissertation,&nbsp; biochemical&nbsp; and&nbsp; physiological parameters&nbsp; in&nbsp; the&nbsp; honey&nbsp; bee&nbsp; were&nbsp; monitored&nbsp; as indicators&nbsp; of&nbsp; the&nbsp; colonies&rsquo;&nbsp; condition&nbsp; during&nbsp; the summer&nbsp; and&nbsp; winter&nbsp; period&nbsp; in&nbsp; habitats&nbsp; with&nbsp; different anthropogenic&nbsp; impacts.&nbsp; In&nbsp; the&nbsp; first&nbsp; phase&nbsp; of&nbsp; the research,&nbsp; acute laboratory tests of honey bee exposure to&nbsp; sublethal&nbsp; doses&nbsp; of&nbsp; pesticides&nbsp; (thiacloprid&nbsp; and clothianidin)&nbsp; were performed and the obtained results indicated&nbsp; impaired&nbsp; neurotransmission,&nbsp; changes&nbsp; in&nbsp; the activity of antioxidant enzymes, and redox status in the cell,&nbsp; as&nbsp; well&nbsp; as&nbsp; immunosuppression.&nbsp; In&nbsp; the&nbsp; second phase&nbsp; of&nbsp; the&nbsp; research,&nbsp; honey&nbsp; bee&nbsp; colonies&nbsp; from different&nbsp; localities&nbsp; in&nbsp; the&nbsp; area&nbsp; of&nbsp; AP&nbsp; Vojvodina&nbsp; were analyzed,&nbsp; using&nbsp; the&nbsp; stationary&nbsp; and&nbsp; migratory&nbsp; types&nbsp; of beekeeping, during the summer and winter period, and the obtained results indicated significant differences in the&nbsp; biochemical response of the honey bee depending on the age of the bees, the season of the year, and the type of apiary. Based on the results of the previous two phases&nbsp; of&nbsp; the&nbsp; research,&nbsp; the&nbsp; selection&nbsp; of&nbsp; samples&nbsp; was performed,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; selection&nbsp; of&nbsp; parameters&nbsp; for analysis within the third phase of the research, where the&nbsp; condition&nbsp; of&nbsp; honey&nbsp; bees&nbsp; from&nbsp; stationary&nbsp; bee communities was monitored during the summer active period,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; beginning&nbsp; and&nbsp; end&nbsp; of&nbsp; winter dormancy of bees, from three localities in the Republic of&nbsp; Serbia&nbsp; with&nbsp; different&nbsp; degrees&nbsp; of&nbsp; urbanization&nbsp; and industrialization: Belgrade as urban, Susek as rural and<br />Zajaca&nbsp; as&nbsp; industrial&nbsp; area.&nbsp; The&nbsp; obtained&nbsp; results indicated&nbsp; significant&nbsp; differences&nbsp; depending&nbsp; on&nbsp; the season&nbsp; of&nbsp; the&nbsp; year,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; location&nbsp; with different&nbsp; anthropogenic&nbsp; influence.&nbsp; Older&nbsp; winter&nbsp; bees are&nbsp; characterized&nbsp; by&nbsp; a&nbsp; higher&nbsp; level&nbsp; of&nbsp; antioxidant protection,&nbsp; associated&nbsp; with&nbsp; a&nbsp; high&nbsp; degree&nbsp; of&nbsp; oxidative damage,&nbsp; better&nbsp; immunocompetence,&nbsp; as&nbsp; well&nbsp; as&nbsp; lowenergy reserves in the fat body. The seasonal increase in&nbsp; the&nbsp; temperature&nbsp; during&nbsp; the&nbsp; year&nbsp; increases&nbsp; the content&nbsp; of&nbsp; saturated&nbsp; while&nbsp; decreasing&nbsp; the&nbsp; ratio&nbsp; of unsaturated&nbsp; fatty&nbsp; acids,&nbsp; where&nbsp; oleic&nbsp; 18:1(9)&nbsp; acid stands&nbsp; out&nbsp; as&nbsp; the&nbsp; dominant&nbsp; component&nbsp; in&nbsp; the&nbsp; total fatty&nbsp; acid&nbsp; content&nbsp; of&nbsp; bee&nbsp; body&nbsp; fat&nbsp; from&nbsp; all&nbsp; three locations,&nbsp; during&nbsp; all&nbsp; three&nbsp; periods.&nbsp; The&nbsp; lower&nbsp; level&nbsp; of total&nbsp; hydrocarbons&nbsp; is&nbsp; another&nbsp; physiological characteristic&nbsp; of&nbsp; winter&nbsp; bees.&nbsp; Also,&nbsp; changes&nbsp; in cholinergic&nbsp; neurotransmission&nbsp; were&nbsp; observed&nbsp; during the&nbsp; season,&nbsp; with&nbsp; higher&nbsp; acetylcholinesterase&nbsp; activities in&nbsp; bees&nbsp; in&nbsp; late&nbsp; winter&nbsp; and&nbsp; summer.&nbsp; Metabolomic analysis of bee hemolymph identified 125 metabolites,included in 36 metabolic pathways, where metabolites in&nbsp; the&nbsp; metabolism&nbsp; of&nbsp; glycerolipids&nbsp; and&nbsp; amino&nbsp; acids glycine,&nbsp; cysteine,&nbsp; glutamine,&nbsp; phenylalanine,&nbsp; proline, and&nbsp; lysine&nbsp; stand&nbsp; out&nbsp; as&nbsp; biomarkers&nbsp; of&nbsp; importance&nbsp; for distinguishing summer and winter bees. By&nbsp; comparing the obtained results between different localities, honey bees&nbsp; from&nbsp; Belgrade&nbsp; stand&nbsp; out&nbsp; with&nbsp; lower&nbsp; levels&nbsp; of oxidative&nbsp; stress,&nbsp; lower&nbsp; activities&nbsp; of acetylcholinesterase&nbsp; as&nbsp; well&nbsp; as&nbsp; phenoloxidase&nbsp; and glucose oxidase, key enzymes in the immune response of&nbsp; bees.&nbsp; The&nbsp; honey&nbsp; bees&nbsp; from&nbsp; Susek&nbsp; had&nbsp; the&nbsp; largest mass of the fat body, which indicates good nutritional and&nbsp; energy&nbsp; reserves&nbsp; in&nbsp; bees&nbsp;&nbsp; during&nbsp; winter&nbsp; and summer,&nbsp; while&nbsp; the&nbsp; honey&nbsp; bees&nbsp; from&nbsp; Belgrade&nbsp; were shown&nbsp; to&nbsp; have&nbsp; a&nbsp; significantly&nbsp; higher&nbsp; ratio&nbsp; of unsaturated&nbsp; fatty&nbsp; acids&nbsp; in&nbsp; the&nbsp; fat&nbsp; body&nbsp; of&nbsp; bees&nbsp; during the&nbsp; year.&nbsp; There&nbsp; were&nbsp; also&nbsp; differences&nbsp; in&nbsp; the&nbsp; relative prevalence&nbsp; of&nbsp; n-alkanes&nbsp; in&nbsp; honey&nbsp; bees&nbsp; from&nbsp; different localities, nonacosane (C29) being the most common in Belgrade, while heptacosane (C27) is most prevalent in honey&nbsp; bee&nbsp; samples&nbsp; from&nbsp; Susek&nbsp; and&nbsp; Zajaca.&nbsp; By analyzing the metal content in honey bees, perga, and honey,&nbsp; it&nbsp; was&nbsp; noted&nbsp; that&nbsp; each&nbsp; environment&nbsp; is characterized by a specific pollution profile, as well as that the concentration of all analyzed metals in honey is significantly lower compared to samples of bees and perga.&nbsp; The&nbsp; obtained&nbsp; results&nbsp; provide&nbsp; a&nbsp; good&nbsp; basis&nbsp; for further studies of the biological response of&nbsp; the honey bee,&nbsp; in&nbsp; terms&nbsp; of&nbsp; the&nbsp; influence&nbsp; of&nbsp; the&nbsp; environmental factors,&nbsp; enabling&nbsp; further&nbsp; defining&nbsp; of&nbsp; appropriate measures for the protection of honey bee colonies.</p>

My study focuses on how the pollination frequence for wild insect pollinators was influenced by the presence of honey bees. Man made beehives, with their thousands of honey bees, can potentially affect wild insect pollinators within 3 km radius. Several studies indicate that this competition will be disadvantageous for wild insect pollinators. The study at hand was conducted in boreal areas of North Swedens southern coastal region. In each area studied, the frequency of pollinators, wild as well as domesticated, was counted in close proximity to beehives and at reference areas, distanced more than 3 kilometres from nearest hive. The reults are somewhat startling, but not statistically significant. In five of the six sites, the wild pollinators were more numerous with honey bees present.

L’acarien Varroa destructor est l’un des principaux responsables de l’effondrement des colonies d’abeilles domestique Apis mellifera. L’arsenal thérapeutique disponible pour lutter contre ce parasite ubiquiste apparait insuffisant à ce jour. Dans le cadre de cette thèse, la démarche de drug design, généralement utilisée en santé humaine, a été appliquée pour le développement de nouveaux médicaments vétérinaire à usage varroacide. Les travaux de cette thèse se sont focalisés sur deux cibles du système nerveux : l’acétylcholinestérase et les récepteurs à l’octopamine. Ces deux cibles ont déjà montré leur intérêt varroacide, notamment au travers des médicaments contenant du coumaphos ou de l’amitraze. Concernant l’acétylcholinestérase, un criblage fait avec le modèle 3D de l’enzyme, construit par homologie de séquences, a permis d’identifier deux composés de la chimiothèque du CERMN. Nous avons également exploré le potentiel varroacide d’acaricides de la famille des carbamates, démontrant l’intérêt du pirimicarbe comme varroacide. Concernant l’octopamine, l’étude de quatre dérivés de l’amitraze a montré l’intérêt de l’un d’entre eux. Un criblage par similarité de structure avec ce dérivé a mis en exergue une molécule issue de la chimiothèque du CERMN. Toutes les molécules pointées par ces travaux de thèse montrent de bons résultats lors de tests in vitro ou in vivo. Toutefois, afin de minimiser le risque pour l’abeille et maximiser l’efficacité anti-varroa, ces leads doivent être optimisés avant d’être ajouté à l’arsenal des médicaments varroacides. / The mite Varroa destructor is one of the main contributors to the collapse of honey bee colonies Apis mellifera. The therapeutic arsenal available against this ubiquitous parasite appears insufficient to date. In this thesis, the drug design approach, generally used in human health, was applied to the development of new varroacide veterinary drugs.The works of this thesis focused on two nervous system targets: acetylcholinesterase and octopamine receptors. These two targets have already shown their varroacide interest, especially through drugs containing coumaphos or amitraz. Regarding acetylcholinesterase, a screening made on the 3D model of the enzyme, built by sequence homology, allowed to identify two compounds from the CERMN compound library. We also explored the varroacide potential of carbamate acaricides, demonstrating the interest of pirimicarb as a varroacide. Regarding octopamine, the study of four derivatives of amitraz has shown the interest of one of them. Structural similarity screening with this derivative highlighted one hit from the CERMN compound library. All molecules pointed out by these thesis works show good results during in vitro or in vivo tests. However, to minimize the risk to honey bees and maximize their anti-varroa efficiency, these leads need to be optimized before being added to the arsenal of varroacide drugs.

Habitat loss and climate change are major factors implicated in the decline of bumble bees worldwide. These factors may be particularly acute in regions subject to climatic extremes such as seasonal drought. Combining methods from pollinator research and phylogenetic community ecology, I investigated the impacts of seasonal drought on plant phenology and bumble bee community ecology across gradients of disturbance and soil moisture in a semi-arid ecosystem. Seasonal fluctuations in floral resources coincided with significant phylogenetic clustering in plant communities, with decreasing plant diversity observed under conditions of increasing drought stress. In the late season, modified wet areas supported higher floral resource availability and greater bumble bee abundances as compared to dry woodlands, though wetlands were also an important source of late season floral resources. Despite these local effects, however, the areal extent of natural vs modified matrix habitat accounted for the majority of variation in models explaining bumble bee abundances. Modified matrix habitat was negatively associated, and natural matrix habitat positively associated, with the occurrence of bumble bee workers in June and late-flying queens in July and August. Results provide insight into the temporal niche dynamics of entomophilous flowering plants in this system, and emphasize the importance of conserving natural habitat diversity in efforts to promote resilient plant-pollinator communities. This study also provides evidence for the local extinction of Bombus occidentalis Greene, 1858 and Bombus suckleyi Greene, 1860 from Galiano Island, BC, Canada, as well as the island’s recent colonization by Bombus vosnesenskii Radoszkowski, 1862. / Graduate

Mergers and acquisitions (M&As) are an ubiquitous feature of modern corporate landscape. Most are entered into for various synergistic (voluntary) reasons whilst some, such as broad-based black economic empowerment (BBBEE) M&As, are driven largely by legislative requirements. Research has shown that the factors that lead to the success or failure of voluntary M&As are many and complex.Whilst there is a plethora of literature regarding the success factors for voluntary M&As, there is, however, a paucity of academic literature on the qualitative factors that lead to the success or failure of BBBEE M&As, despite quantitative studies showing the benefits of BBBEE M&As. Because of the significance of BBBEE to the economic development of the country, policy makers, academics and business people need to fully understand such factors.Given the dearth of academic literature on the subject, a qualitative, exploratory study conducted by way of face to face, expert, semi-structured interviews, was undertaken to answer the research problem.The study found that whilst BBBEE M&As are similar, in some respects, to voluntary M&As, BBBEE M&As require different or additional success factors to those applicable to voluntary M&As. Some of these are: funding structure, transaction rationale, expectations&#8223; alignment, clear deliverables, active governance, operational involvement, relationship management, transformation and social investment. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

Cuckoo bees behave similarly to the well-known birds, cuckoos - they lay eggs in the nests of other bees. Proposed thesis charts the evolution of host specialization within the strictly cuckoo genus Sphecodes. According to the classical view based on the Red Queen hypothesis, parasites should gradually specialize during evolution to keep pace in the "arms race" with their hosts. Specialization is also perceived as an evolutionary dead end - narrow adaptation prevents change of host. To test these hypotheses phylogeny of tribus Sphecodini based on the partial sequences of five genes was constructed. For each ancestor has been by two methods of mapping ancestral characters (Bayesian method, Maximum Parsimony) specified, whether it was specialist or generalist and which kind of host or hosts it had. The results show that the original strategy of genus Sphecodes is specialization and generalists originated from specialized ancestors only recently. The results also show that the jumps between the hosts are common. These findings are inconsistent with the Red Queen hypothesis as well as with the view that specialization is an evolutionary dead end. Falsity of these hypotheses within the genus Sphecodes established also likelihood ratio test, in which the likelihood of model allowing two-way transition...

Finite Element Model Updating has recently arisen as an issue of vast importance on the design, construction and maintenance of structures in civil engineering. Many algorithms have been proposed, developed and enhanced in order to accomplish the demands of the updating process, mainly to achieve computationally efficient programs and greater results.The present Master Thesis proposes two new algorithms to be used in Finite Element Model Updating: the Bees Algorithms (BA) and the Artificial Bee Colony algorithm (ABC). Both were first proposed in 2005, are based on the foraging behaviour of bees and have been proved to be efficient algorithms in other fields. The objective of this Master Thesis is, thus, to implement and to test these two newalgorithms in Finite Element Model Updating for a cantilever beam. The Finite Element Model and the algorithms are programmed, followed by the extraction of the experimental frequencies and the updating process. Results, comparison of these two methods and conclusions are given at the end of this report, as well as suggestions for further work.

Understanding the relationships between solitary bees’ flight phenology and flowering phenology is important in the context of global warming. Using Swedish citizen science data, observations of oligolectic solitary bees and flowering phenology were used together with temperature data. All five bees studied had flight period that overlapped with the flowering period their corresponding host plant. None of the species were affected by the temperature, although there was a correlation between earliest observations of flowering phenology and flight phenology. The later the flowering observation was made, the later the flight observation was made. No correlation was found between the length of flight period and length of the flowering period. Increasing temperature is not the only factor that effects flight phenology and flowering phenology.

No description available.