138 research outputs found
Evaluation of differential gene expression during behavioral development in the honeybee using microarrays and northern blots
BACKGROUND: The honeybee (Apis mellifera) has been used with great success in a variety of behavioral studies. The lack of genomic tools in this species has, however, hampered efforts to provide genome-based explanations for behavioral data. We have combined the power of DNA arrays and the availability of distinct behavioral stages in honeybees to explore the dynamics of gene expression during adult development in this insect. In addition, we used caffeine treatment, a procedure that accelerates learning abilities in honeybees, to examine changes in gene expression underlying drug-induced behavioral modifications. RESULTS: Spotted microarrays containing several thousand cDNAs were interrogated with RNAs extracted from newly emerged worker bees, experienced foragers and caffeine-treated bees. Thirty-six differentially expressed cDNAs were verified by northern blot hybridization and characterized in silico by sequencing and database searches. Experienced foragers overexpressed royal jelly proteins, a putative imaginal disc growth factor, a transcriptional regulator (Stck) and several enzymes, including α-glucosidases, aminopeptidases and glucose dehydrogenase. Naive workers showed increased expression of members of the SPARC and lectin families, heat-shock cognate proteins and several proteins related to RNA translation and mitochondrial function. A number of novel genes overexpressed in both naive and experienced bees, and genes induced by caffeine, have also been identified. CONCLUSIONS: We have shown the usefulness of this transcriptome-based approach for gene discovery, in particular in the context of the efficacy of drug treatment, in a model organism in which routine genetic techniques cannot be applied easily
Light-inducible transcriptomic and epigenomic changes underlying brain plasticity in honeybees
Light-inducible transcriptomic and epigenomic changes underlying brain plasticity in honeybees
Dissertação de Mestrado apresentada à Faculdade de Letras da Universidade de Coimbra.Pretendemos, com esta dissertação, fundamentar a categorização como ritual laico da Arte como Veículo, propósito da última fase do trabalho de Jerzy Grotowski, discutindo os modos particulares dessa categorização.
No primeiro capítulo expomos, resumidamente, o percurso artístico de Grotowski e as principais influências que marcaram o seu pensamento. Explicamos os conceitos fundamentais que estruturam a sua prática artística e ensaiamos uma definição para a Arte como Veículo. Finalizamos o capítulo com uma discussão sobre a categorização como ritual das criações performativas produzidas segundo este modelo.
No segundo capítulo abordamos o ritual como performance e discutimos a origem ritual dos géneros estéticos performativos. Apresentamos definições operativas de ritual e performance e abordamos os principais aspectos do ritual enquanto performance, recorrendo sobretudo à Antropologia da Performance de Victor Turner. No final do capítulo exploramos a categorização da Arte como Veiculo como ritual, à luz da Antropologia da Performance.
No terceiro capítulo fazemos um estudo sumário de um ritual tradicional, o culto dos Theyyams do Norte Malabar, na Índia. Contextualizamos e descrevemos o ritual e algumas das suas particularidades. Relatamos as impressões recolhidas durante um estudo de campo na região, à luz da experiência da Arte como Veículo e dos aspectos realçados pela Antropologia da Performance.
Concluímos com a enumeração de resultados obtidos e a confrontação entre o que se apurou na investigação sobre a Arte como Veículo e as impressões recolhidas no estudo do Theyyam, apontando-se desenvolvimentos que possam futuramente confirmar ou reforçar os resultados agora apresentados.With this dissertation I intend to justify the categorization as a secular ritual of the Art as Vehicle, the last phase of Jerzy Grotowski's work, discussing the particular ways of this categorization.
In the first chapter I briefly expose the artistic course of Grotowski and the main influences that marked his thought. I explain the fundamental concepts that structure his artistic practice and I essay a definition for Art as Vehicle. I end the chapter with a discussion of the categorization as a ritual of performing works created according to this model.
In the second chapter I address the ritual as performance and briefly discuss the ritual origin of performative aesthetic genres. I propose operative definitions for ritual and performance and I enumerate the main aspects of ritual as performance, calling upon, mostly, the Anthropology of Performance from Victor Turner. At the end of the chapter I explore the categorization as ritual of Art as Vehicle at the light of the Anthropology of Performance.
In the third chapter I make a summary study of a traditional ritual, the worship of Theyyams in the North Malabar, India. I contextualize and describe the ritual and some of its special features. I report the impressions gathered during a field study in the region, at the light of the experience of Art as Vehicle and of the aspects highlighted by the Anthropology of Performance.
I conclude with an enumeration of results and the confrontation between what was found in the research on Art as Vehicle and the impressions gathered in the study of Theyyam, pointing out future developments that may confirm or strengthen the results now presented
AlGaInN laser diode technology for GHz high-speed visible light communication through plastic optical fiber and water
AlGaInN ridge waveguide laser diodes are fabricated to achieve single-mode operation with optical powers up to 100 mW at ∼420 nm∼420 nm for visible free-space, underwater, and plastic optical fiber communication. We report high-frequency operation of AlGaInN laser diodes with data transmission up to 2.5 GHz for free-space and underwater communication and up to 1.38 GHz through 10 m of plastic optical fiber
Epigenetic regulation of the honey bee transcriptome: unravelling the nature of methylated genes
Background: Epigenetic modification of DNA via methylation is one of the key inventions in eukaryotic evolution. It provides a source for the switching of gene activities, the maintenance of stable phenotypes and the integration of environmental and genomic signals. Although this process\ud
is widespread among eukaryotes, both the patterns of methylation and their relevant biological roles not only vary noticeably in different lineages, but often are poorly understood. In addition, the evolutionary origins of DNA methylation in multicellular organisms remain enigmatic. Here we used a new 'epigenetic' model, the social honey bee Apis mellifera, to gain insights into the significance of methylated genes.\ud
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Results: We combined microarray profiling of several tissues with genome-scale bioinformatics and bisulfite sequencing of selected genes to study the honey bee methylome. We find that around 35% of the annotated honey bee genes are expected to be methylated at the CpG dinucleotides by a highly conserved DNA methylation system. We show that one unifying feature of the methylated genes in this species is their broad pattern of expression and the associated 'housekeeping' roles. In contrast, genes involved in more stringently regulated spatial or temporal functions are predicted to be un-methylated.\ud
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Conclusion: Our data suggest that honey bees use CpG methylation of intragenic regions as an epigenetic mechanism to control the levels of activity of the genes that are broadly expressed and might be needed for conserved core biological processes in virtually every type of cell. We discuss the implications of our findings for genome-scale regulatory network structures and the evolution\ud
of the role(s) of DNA methylation in eukaryotes. Our findings are particularly important in the context of the emerging evidence that environmental factors can influence the epigenetic settings of some genes and lead to serious metabolic and behavioural disorders
Probabilistic reconstruction of measles transmission clusters from routinely collected surveillance data.
Pockets of susceptibility resulting from spatial or social heterogeneity in vaccine coverage can drive measles outbreaks, as cases imported into such pockets are likely to cause further transmission and lead to large transmission clusters. Characterizing the dynamics of transmission is essential for identifying which individuals and regions might be most at risk. As data from detailed contact-tracing investigations are not available in many settings, we developed an R package called o2geosocial to reconstruct the transmission clusters and the importation status of the cases from their age, location, genotype and onset date. We compared our inferred cluster size distributions to 737 transmission clusters identified through detailed contact-tracing in the USA between 2001 and 2016. We were able to reconstruct the importation status of the cases and found good agreement between the inferred and reference clusters. The results were improved when the contact-tracing investigations were used to set the importation status before running the model. Spatial heterogeneity in vaccine coverage is difficult to measure directly. Our approach was able to highlight areas with potential for local transmission using a minimal number of variables and could be applied to assess the intensity of ongoing transmission in a region
INTELIGENTNY SYSTEM DIAGNOSTYKI I STEROWANIA PRZEPŁYWAMI DWUFAZOWYMI NA PODSTAWIE POMIARÓW 3D ECT
In this paper the new intelligent system for two-phase flows diagnosis and control is presented. The authors developed a fuzzy inference system for two phase flows recognition based on the raw 3D ECT data statistical analysis and fuzzy classification which identify the flow structure in real-time mode. The non-invasive three-dimensional monitoring is possible to conduct even in non-transparent and non-accessible parts of the pipeline. Presented system is also equipped with the two phase gas-liquid flows installation control module based on fuzzy inference which includes the feedback information from the recognition module. The intelligent control module working in a feed-back loop keep the sets of required flow regime. Presented in this paper fuzzy algorithms allow to recognize the two phase processes similar to the human expert and to control the process in the same, very intuitively way. Using of the artificial intelligence in the industrial applications allows to avoid any random errors as well as breakdowns and human mistakes suffer from lack of objectivity. An additional feature of the system is a universal multi-touched monitoring-control panel which is an alternative for commercial solution and gives the opportunity to build user own virtual model of the flow rig to efficiently monitor and control the process.W artykule zaprezentowany został inteligentny system diagnostyki i sterowania przepływami dwufazowymi gaz-ciecz. Autorzy opracowali rozmyty system wnioskowania oparty o statystyczną analizę i klasyfikację rozmytą surowych danych pomiarowych 3D ECT realizujący w czasie rzeczywistym identyfikację struktury przepływu oraz wyznaczanie objętościowego udziału faz. Nieinwazyjny trójwymiarowy monitoring przepływu możliwy jest w nieprzezroczystych i trudno dostępnych fragmentach rurociągów w czasie rzeczywistym. Prezentowany system wyposażony jest również w moduł sterowania instalacją w oparciu o wnioskowanie rozmyte, któremu na wejście podawane są informacje zwrotne od modułu rozpoznawania. Inteligentny regulator rozmyty pracujący w pętli sprzężenia zwrotnego utrzymuje żądane nastawy parametrów przepływu w oparciu o zadany reżim przepływu. Przedstawione w niniejszym opracowaniu algorytmy rozmyte umożliwiają identyfikację procesów dwu-fazowych w sposób analogiczny do tego, jak to robią specjaliści oraz jednocześnie pozwalają kontrolować proces w ten sam bardzo intuicyjny sposób. Zastosowanie sztucznej inteligencji w aplikacjach przemysłowych pozwala uniknąć przypadkowych ludzkich błędów podatnych na brak obiektywizmu, a także zapobiegać awarii. Cechą dodatkową systemu jest uniwersalny dotykowy panel monitorująco-sterujący stanowiący alternatywę dla drogich komercyjnych rozwiązań umożliwiający budowanie wirtualnego modelu instalacji, aby w szybki i skuteczny sposób móc ją monitorować i nią sterować
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