18 research outputs found
Hybrid Advanced Optimization Methods with Evolutionary Computation Techniques in Energy Forecasting
More accurate and precise energy demand forecasts are required when energy decisions are made in a competitive environment. Particularly in the Big Data era, forecasting models are always based on a complex function combination, and energy data are always complicated. Examples include seasonality, cyclicity, fluctuation, dynamic nonlinearity, and so on. These forecasting models have resulted in an over-reliance on the use of informal judgment and higher expenses when lacking the ability to determine data characteristics and patterns. The hybridization of optimization methods and superior evolutionary algorithms can provide important improvements via good parameter determinations in the optimization process, which is of great assistance to actions taken by energy decision-makers. This book aimed to attract researchers with an interest in the research areas described above. Specifically, it sought contributions to the development of any hybrid optimization methods (e.g., quadratic programming techniques, chaotic mapping, fuzzy inference theory, quantum computing, etc.) with advanced algorithms (e.g., genetic algorithms, ant colony optimization, particle swarm optimization algorithm, etc.) that have superior capabilities over the traditional optimization approaches to overcome some embedded drawbacks, and the application of these advanced hybrid approaches to significantly improve forecasting accuracy
First molecular and biochemical characterization of the extracellular matrix of Saccharomyces cerevisiae
Programa Doutoral em Biologia Molecular e Ambiental (área de especialização em Biotecnologia Molecular)A levedura Saccharomyces cerevisiae, tal como todos os microrganismos, é
usualmente considerada como um organismo unicelular. Contudo, os microrganismos
formam mais frequentemente comunidades multicelulares macroscópicas que
apresentam diferenciação celular, e são coordenadas por um complexo sistema de
comunicação, e suportadas por uma matriz extracelular (MEC). A presença deste tipo de
suporte das comunidades multicelulares de S. cerevisiae foi descrita no início deste
século. Apesar disso, a informação relacionada com a sua composição e organização
tridimensional é escassa. Assim, o principal objetivo deste trabalho foi realizar a
primeira abordagem sistemática aos principais componentes da MEC de levedura. Para
o efeito, foram desenvolvidas metodologias para (1) obter de forma reprodutível uma
considerável e homogénea biomassa de leveduras produtora de MEC, e (2) extrair e
fracionar a MEC produzida de forma a obter frações analiticamente puras de proteínas e
polissacáridos, compatíveis com a aplicação de metodologias analíticas de alto-débito
como o GC-MS e o DIGE.
A análise detalhada da fração proteica permitiu a identificação de mais de 600
proteínas. A maioria destas tem função e localização intracelulares, e é aqui identificada
extracelularmente pela primeira vez, o que pode indicar um moonlighting
surpreendentemente elevado. A presença de todas as enzimas associadas à glicólise e à
fermentação, assim como ao ciclo do glioxilato, levanta suspeitas sobre a possibilidade
de haver metabolismo extracelular. Além disso, um grande número de proteínas
associadas à síntese, remodelação e degradação de outras proteínas foi identificado,
incluindo elementos da família HSP70 e várias proteases. De realçar a presença das
exopeptidases Lap4, Dug1 e Ecm14, e das metaloproteinases Prd1, Ape2 e Zps1, que
partilham um domínio funcional zincin com as metaloproteinases da MEC de Eucariotas
superiores. A presença adicional de proteínas intervenientes em várias vias de
sinalização, como as Bmh1 e Bmh2, e da homing endonuclease Vde, que partilha o domínio Hedgehog/inteína com os morfogenos de Eucariotas superiores, sugere que a
MEC de levedura poderá, tal como nesses organismos, mediar sinalização intercelular.
As análises cromatográfica e eletroforética da fração glicosídica revelaram
claramente a presença de dois polissacáridos. A análise por espectrometria de massa
identificou glucose, manose e galactose na composição destes polissacáridos. Foram
ainda observados indícios da presença de ácido urónico. A indução de metacromasia
sugeriu que os polissacáridos detetados apresentam substituição química. A possibilidade desta corresponder a sulfatação foi testada através de um teste de atividade
anticoagulante. Das diversas amostras de MEC de diferentes estirpes de levedura
usadas, o duplo mutante gup1Δgup2Δ apresentou, ao contrário da estirpe Wt, razoável
atividade anticoagulante indicadora da presença de grupos sulfato.
Os efeitos da deleção do gene GUP1 na composição da MEC de levedura
proporcionaram uma perspectiva mais detalhada da composição molecular e
mecanismos a ela associados. Observaram-se alterações nas frações protéica e
glicosídica. A deleção resultou na ausência de várias proteínas, associadas
principalmente com o metabolismo de fontes de carbono, defesa e resgate da célula,
bem como síntese, modificação e degradação de proteínas, e organização celular.
Adicionalmente, a deleção deste gene também teve um grande impacto na composição
glicosídica da matriz, levando ao desaparecimento do polissacárido de maior peso
molecular detetado na estirpe Wt. Globalmente, os efeitos da deleção do GUP1 na MEC
mostram que a estrutura desta é muito dinâmica e que se encontra sob controlo apertado
das células que compõem o agregado multicelular.
As funções sugeridas para as proteínas ortólogas das Gup1 e Gup2 de levedura,
respetivamente Hhatl e Hhat, nas vias de sinalização de Eucariotas superiores esteve na
origem da construção de uma bateria de estirpes de levedura recombinantes
transformadas com os ortólogos da via Hedgehog de ratinho, mosca e homem, para
futura avaliação. Da mesma forma, foram clonados em S. cerevisiae os recetores de
mamífero para o ácido hialurónico (AH), CD44 e HMMR. Estes transformantes foram
submetidos ao crescimento na presença de AH de diferentes tamanhos moleculares. As
estirpes exprimindo ambos os recetores foram igualmente sensíveis à presença de AH
de elevado peso molecular, mas foram diferentemente sensíveis à presença de AH de
tamanho molecular intermédio. As células expressando o recetor CD44 mostraram-se, tal como em Eucariotas superiores, sensíveis à presença de AH 50 kDa, apresentando
uma forte redução da taxa específica de crescimento. Isto indica a expressão funcional
dos recetores de AH em levedura e a provável conservação da maquinaria celular de
resposta a este componente da MEC dos Eucariotas superiores.
Este trabalho é o primeiro a apresentar um estudo detalhado sobre as frações
protéica e glicosídica secretadas para a matriz extracelular de S. cerevisiae durante o seu
crescimento em comunidades multicelulares, oferecendo a primeira abordagem
proteómica e glicómica da sua composição e organização. Globalmente, este trabalho
permite prever que a MEC de levedura exerça funções equivalentes às conhecidas da
MEC de Eucariotas superiores.The yeast Saccharomyces cerevisiae, as all microbes, is generally regarded as a
unicellular organism. However, microorganisms live more frequently in macroscopic
multicellular aggregates, presenting cellular differentiation, coordinated by complex
communication, and supported by an extracellular matrix (ECM). The presence of this
type of structure supporting multicellular life-style of S. cerevisiae was first described
early this century. However, the information available on the yeast ECM components
and three-dimensional spatial organization is scarce. Hence, this work aimed to provide
a first methodical insight into the molecular composition of the yeast ECM major
components. A methodology was developed capable of reproducibly obtaining ECMproducing
homogenous yeast mats, and extracting and fractionating the yeast ECM into
analytical-grade fractions. This was developed in order to be fully compatible with the
application of high-throughput analytical techniques, like GC-MS and DIGE.
The in-depth analysis of the proteins in the yeast ECM identified more than 600
proteins, most of which being ascribed to intracellular functions and localization, and
therefore found extracellularly for the first time. This might indicate unexpectedly
extensive moonlighting. The entire sets of enzymes from glycolysis and fermentation, as
well as gluconeogenesis through glyoxylate cycle were highly represented, raising
considerable reason for doubt as whether extracellular metabolism might exist.
Moreover, a large number of proteins associated with protein fate and remodelling were
found. These included several proteins from the HSP70 family, and proteases,
importantly, the exopeptidases Lap4, Dug1 and Ecm14, and the metalloproteinases
Prd1, Ape2 and Zps1, sharing a functional zincin domain with higher Eukaryotes ECM metalloproteinases. The further presence of the broad signalling cross-talkers Bmh1 and
Bmh2, as well as the homing endonuclease Vde that shares a Hedgehog/intein domain
with the Hh morphogens from higher Eukaryotes, suggest that analogously to the tissues
in these organisms, yeast ECM is mediating signalling events.
The chromatographic and electrophoretic analysis of the sugar fraction revealed
the clear presence of two distinct polysaccharides. Mass spectrometry identified
glucose, mannose and galactose in their composition. Evidence was also obtained of the
presence of uronic acids. Both polysaccharides showed chemical substitution, as indicated by metachromasia, and the existence of sulphate groups was assessed through
an anticoagulant activity test. From several ECM samples from different yeasts strains
surveyed, the double mutant gup1Δgup2Δ displayed a relatively high anticoagulant
activity, which was not observed in Wt, likely related to the presence of sulphate
groups.
The effects of the deletion of GUP1 gene in the composition of yeast ECM were
also assessed, providing a more in-depth perspective of the ECM components and
molecular mechanisms associated. Alterations in both protein and sugar fractions were
observed. The deletion of GUP1 led to the absence of several ECM proteins, mainly
associated with the carbon metabolism, cell rescue and defence, protein fate and cellular
organization. Additionally, the disruption of this gene impacted in the composition of
the ECM sugar fraction, through the disappearance of the higher molecular weight
polysaccharide that had been detected in the Wt sample. The effects of GUP1 deletion
on the ECM show that its structure is very dynamic, and that it is under the tight control
of the cells composing the aggregate.
S. cerevisiae Gup1 and Gup2 orthologues have suggested regulatory roles in the
Hedgehog signalling pathway from higher Eukaryotes, in which organisms these
proteins are known as Hhatl and Hhat, respectively. This led to the engineering the
yeast mutants defective on either or both GUP1 and GUP2 by expressing these genes
orthologues from fly, human and mouse, yielding a collection of transformants for
future assessment. Similarly, the mammalian receptors of hyaluronic acid (HA), CD44 and HMMR, were cloned into the yeast S. cerevisiae. The engineered strains were
subjected to growth in the presence of different molecular sizes of HA, and were
identically and differentially sensitive to, respectively, high and intermediate molecular
weight HA. The strain expressing CD44 presented a high growth sensitivity to the
presence of 50 kDa HA as in high Eukaryotes. The HA receptors are therefore
functional in the yeast cell, and the cellular machinery to respond to HA stimuli appears
to be fairly conserved.
The present work is the first to present a comprehensive detailed study on the
protein and polysaccharide fractions secreted during growth in S. cerevisiae
multicellular aggregates. Overall, this work gives a first insight of the multicellular
communities of S. cerevisiae proteomics and glycomics, ascertaining yeast ECM with
putative roles derived from its components that resemble ECM from higher Eukaryotes
A grammar of Chukchi
The aim of this work is to produce the first fieldwork-based, typologically Informed
reference grammar of Chukchi, an Indigenous language of the north-eastern corner
of the Russian Federation. The theoretical approach is low-key and eclectic;
linguistic phenomena are described in a manner which is, in so far as it is possible,
theory-neutral, although where a branch of linguistic theory provides tools which
allow clear and simple description it is used without hesitation. Linguistic
description is, however, primary throughout.
The first five chapters of the thesis provide background information. Chapter I
sketches the sociolinguistic situation in Chukchl, discusses the sources of data used
for analysis, and surveys relevant linguistic publlcations. Chapter 2 discusses
linguistic variation within Chukchi. The Chukchi men's and women's dialects are
discussed within a framework of a comparison of Chukchi and the neighbouring
dialects and languages of the Koryako-Chukotian group. The phonological system
of Chukchi is described in chapter 3. Chapters 4 and 5 survey word classes and
sentence types respectively.
The following four chapters are concerned with nominals. Nominal inflection is
described in chapter 6 and the different types of free pronouns are discussed in
chapter 7. In chapter 8 there is a description of nominal morphology, which pays
particular attention to deverbal noun subtypes, such as participles and action
nouns. Chapter 9 is concerned with complex nouns, including complex noun
phrases (which can only occur in the absolutive case) and nouns with incorporation.
A discussion of verbs takes up the next five chapters. Chapter 10 contains a
description of verbal inflection, a complex and theoretically interesting area of
Chukchi. An account of inflectional morphology is proposed based on the notion of
'inverse alignment' and grammaticalisation of pictotypical agency relationships.
Chapter 11 describes valency, surveying transitivity types and describing the
valency changing and rearranging derivations available in the language, including
antipassive, causative and applicative. Incorporation and compounding by verbs is
discussed in chapter 12. Chapter 13 contains a discussion of non-finite deverbal
forms, including converbs (a deverbal adverb which forms the head of an adverbial
subordinate clause), verb bases (the lexical heads of auxiliary verbs, and the infinitive. Chapter 14 surveys non-valency-changing verbal derivations, which
have aspectual, quantifier and modal meanings, among others.
The remaining chapters address a range of topics. Chapter 15 has a discussion of
the various ways of expressing spatial relationships. In chapter 16 there is a
description of the adjective and the numeral word classes. Non-verbal predication
and a description of the behaviour of copulas and auxiliaries is found in Chapter
17. Chapter 18 addresses the complex area of negation, including a description of
the various types of negative clauses and the ways of negating various constituent
types. Finally, in chapter 19 there is an account of the pragmatic principles
determining constituent order based on a discussion of topic and focus
Tartu Ülikooli toimetised. Tööd semiootika alalt. 1964-1992. 0259-4668
http://www.ester.ee/record=b1331700*es
Second Assessment of Climate Change for the Baltic Sea Basin
Earth System Sciences; Atmospheric Sciences; Baltic Sea; Environmental Impacts; Regional Climate Change; Regional Climate Projection