G-structures and duality

Imperial Users onl

Cost and benefits of the morphological defences in larvae of Scymnus nubilus Mulsant (Coleoptera: Coccinellidae)

Dissertação de Mestrado - Biotecnologia em Controlo Biológico.Diferentes mecanismos de defesa contra a predação e parasitismo evoluíram entre os insectos. Estes podem ser químicos, comportamentais ou estruturais. As larvas do pequeno coccinelídeo Scymnus nubilus estão cobertas por uma camada de ceras que podem actuar como um mecanismo defensivo contra formigas e outros predadores. No entanto, o grau de protecção conferido pelas ceras às larvas de Scymnus não é bem conhecido. O objectivo deste estudo foi avaliar alguns dos custos e benefícios da produção de ceras nos S. nubilus. De acordo com a teoria da evolução das histórias de vida, um maior desempenho de um traço específico implica um decréscimo noutro traço. Se a produção das ceras é metabolicamente dispendiosa para as larvas, esperamos alguns custos no tempo de desenvolvimento, crescimento e futuro potencial reprodutor. Devido ao facto de potenciais trade-offs serem apenas evidentes quando um organismo está sobre condições de stress, avaliámos as consequências da produção de ceras no tempo de desenvolvimento, fisiologia alimentar e potencial reprodutor nas larvas com e sem ceras (removidas artificialmente). Do ponto de vista fisiológico, espera-se que a remoção das ceras das larvas induzirá um consumo maior de presas de modo a que se cumpram os requerimentos metabólicos necessários para o crescimento e produção de ceras. A equilibrar estes custos e a alocação energética, propomos que as ceras actuarão como um sistema defensivo contra a C. agilis um predador intraguilde. Os resultados demonstram que existiram diferenças entre os parâmetros biológicos das larvas com e sem ceras, mais especificamente no crescimento larval. Ao contrário do previsto, o consumo de presas das larvas com e sem ceras não variou, embora o peso ganho tenha sido maior nas primeiras. Isto é uma indicação que para produzir as ceras há necessidade de distribuir os recursos e o crescimento é reduzido. As ceras reduziram a predação intraguilde, tal como esperado.ABSTRACT: Among insects different defence mechanisms evolved against predation and parasitism. Defences can be chemical, behavioural and/or morphological. The larvae of the small aphidophagous coccinellid Scymnus nubilus are covered by a wax layer that might act as a defensive mechanism against ants and other predators. However, the degree of protection conferred by waxes in Scymnus larvae is not very well known. The objective of the study was to evaluate some of the costs and benefits of wax production in S. nubilus. According to life history evolution theory, increased performances in one trait entail a decrease in another trait. If wax production is metabolically costly to larvae, we expect some costs on developmental time, growth or future reproductive potential. Because potential trade-offs are only evident when the organism are under stressful conditions, we evaluated the consequences of wax production to developmental time, alimentary physiology and potential reproductive effort in larvae either wax and waxless (artificially removed). From a physiological point of view we expect waxless larvae will display higher prey consumption in order to meet metabolic requirements for growth and wax production. To balance these costs and energetic allocation we propose that waxes might act as a defensive mechanism against an intraguild predator, the lacewing Chrysoperla agilis. Our results showed that there were differences between the biological parameters of wax and waxless larvae, specifically, in the larval growth. Contrary to our prediction, prey consumption of wax and waxless did not vary significantly although relative weight gain was higher in wax larvae. This indicates that in order to produce waxes, resources need to be re-allocated and growth is reduced. Waxes reduced intraguild predation as predicted

The Spectrum of Red Colour Names in Portuguese

Colour names behave quite differently in different languages. In fact, each language, or language group, sets its own colour naming system. Romance languages (along with some Germanic languages) inherited the central name for red from an Indo-European root h1reudh (see ruber / rubeus (Latin) and rosso (Italian), rouge (French), rojo (Spanish), roig (Catalan), red (English), rot (German), rood (Dutch) or rød (Danish)). The cognate noun both in Galician and in Portuguese (i.e. roxo), even though it may have been used as a name for red, it is now the colour name that can be translated into English by the noun purple. These two eastern peripheral romance languages, along with Catalan, favoured the Latin noun vermiculus (cf. vermello (Galician), vermelho (Portuguese) and vermell (Catalan)) as the unmarked designation for red. Counter wise, it is also possible to find cognate words in the above-mentioned first set of languages, but these words refer less central red hues (cf. vermiglione (Italian), bermejo (Spanish), vermilion (English), vermiljoen (Dutch), vermilion (Danish)) or even a non-colour term, like the French vermeil. In this paper, we discuss the variation that the spectrum of red colour names exhibits in a small set of languages, somehow related to Portuguese, which is set at the centre stage. This discussion takes their etymological relationships, their chronological nexus and their contemporary reinterpretations in numeric encodings, such as RGB or CMY into consideration. The analysis of these data allows inferring that the large array of colour and hues, shades and tints, as described, for instance by the Munsell colour system, has no linguistic equivalence: colour names reflect a limited amount of colour distinctions, fulfilled by an unstable set of nouns.Colour names change within and across languages, they frequently change in time and their meaning also often changes. Probably, all this instability is set for independent linguistic reasons, related to the effects of language contact situations and to strict lexical principles, such as economy. Portuguese will again be invoked to demonstrate that derived or compound names used to refer to those chromatic narrow distinctions may keep their stylistic or literary pertinence, but are unable to maintain any unambiguous meaning.info:eu-repo/semantics/publishedVersio

Self-service kiosk-based anamnesis system for emergency departments

Dissertação de mestrado integrado em Engenharia InformáticaEmergency departments have a higher number of visits compared to other hospital de partments. Technology has played a crucial role in promoting improvements in hospital management and clinical performance. The number of visits to emergency departments has increased considerably, giving rise to crowding situations that cause several adverse effects. This situation negatively affects the provision of emergency services, impairs the quality of health care and increases the time patients wait for medical check-up. One of the leading causes contributing to the crowding is the high number of patients with low severity clinical condition. These are referred to as non-urgent or inappropriate patients, whose clinical situation should be taken care through self-care or primary health care. It is the responsibility of the institutions to analyse and quantify the possible causes of crowding to find the best solution to mitigate the adverse effects caused. It is believed that non-urgent patients can use the time spent in the waiting room more productively, namely by using a self-service kiosk to which they can provide valuable information to facilitate and accelerate the clinical processing. This work proposes a solution to be used in the waiting room of emergency departments, which aims to reduce the period of medical check-up. The solution uses a self-service kiosk for the patient to provide relevant clinical data that would otherwise have to be collected by the physician during the clinical observation process. In particular, the kiosk will collect vital signs, past medical history, main complaint and usual medication. This data will be processed and provided to the physician in a structured and uniform way before each medical check-up. The primary purpose of this solution is to reduce the period of patients’ medical check-up and thus improve the response capacity of the emergency departments with the same resources. During the Master’s work period, an Android application was implemented for patients to enter the clinical data mentioned above, and a Web application for physicians to access it. Additionally, a data warehouse was implemented to store the data in a consolidated way to discover hidden relationships and patterns in the data. The first moment of evaluation, undertaken in a non-hospital facility, shows positive acceptability by participants, with a large majority considering the system user-friendly. Due to the pandemic, it was impossible to perform the second planned evaluation moment in a real emergency environment.Os serviços de urgência apresentam um número de visitas superior em comparação com outros serviços presentes nas instituições hospitalares. A afluência aos serviços de urgências tem vindo a aumentar consideravelmente, dando origem a situações de lotação que provocam diversos efeitos negativos nas instituições hospitalares. No geral, este fenômeno afeta negativamente a prestação dos serviços de urgência, prejudica a qualidade dos cuidados de saúde e faz aumentar o tempo que os doentes aguardam pela observação clínica na sala de espera. Uma das principais causas apontadas para o surgimento da lotação é o elevado número de doentes com condição clínica de baixa gravidade. Estes são designados como doentes não-urgentes ou inapropriados, cuja condição clínica poderia ser resolvida, idealmente, com recurso ao auto-cuidado ou a cuidados de saúde primários. É da responsabilidade das instituições analisar e quantificar as possíveis causas de lotação, de forma a encontrar a melhor solução para atenuar os efeitos negativos provocados. Acredita-se que os doentes não-urgentes tenham a capacidade de utilizar o tempo na sala de espera de forma mais produtiva, através da utilização de um quiosque self-service. Neste sentido e aliada à tecnologia, esta dissertação contextualiza uma solução para ser utilizada na sala de espera dos serviços de urgência, visando reduzir o período de observação clínico. Esta solução vem complementar a realização do procedimento inicial efetuado pelo médico, no consultório, através do uso de um quiosque. Assim, a recolha dos sinais vitais, história médica prévia, queixa principal e medicação habitual será efetuada pelos doentes no quiosque. Estes dados vão ser fornecidos de forma estruturada e organizada ao médico antes da realização da consulta. O objetivo principal desta solução é reduzir o período de observação clínico e assim melhorar a capacidade de resposta dos serviços de urgência com os mesmos recursos hospitalares. Durante o período da dissertação, foi implementada uma aplicação Android para os pacientes registarem os dados clínicos acima mencionados, e uma aplicação Web para os médicos acederem aos mesmos. Foi implementado também um data warehouse para a descoberta de relações e padrões escondidos nos dados. O primeiro momento de avaliação, realizado num ambiente não hospitalar, mostrou uma aceitabilidade positiva pelos partici pantes, com grande maioria a considerar o sistema user-friendly. Devido à pandemia, não foi possível realizar o segundo momento de avaliação planeado num serviço de urgências

M-theory, exceptional generalised geometry and superpotentials

We discuss the structure of "exceptional generalised geometry" (EGG), an extension of Hitchin's generalised geometry that provides a unified geometrical description of backgrounds in eleven-dimensional supergravity. On a d-dimensional background, as first described by Hull, the action of the generalised geometrical O(d,d) symmetry group is replaced in EGG by the exceptional U-duality group E_d(d). The metric and form-field degrees of freedom combine into a single geometrical object, so that EGG naturally describes generic backgrounds with flux, and there is an EGG analogue of the Courant bracket which encodes the differential geometry. Our focus is on the case of seven-dimensional backgrounds with N=1 four-dimensional supersymmetry. The corresponding EGG is the generalisation of a G_2-structure manifold. We show it is characterised by an element \phi in a particular orbit of the 912 representation of E_7(7), which defines an SU(7) (subset of E_7(7)) structure. As an application, we derive the generic form of the four-dimensional effective superpotential, and show that it can be written in a universal form, as a homogeneous E_7(7)-invariant functional of \phi.Comment: 36 pages, 3 tables, youngtab.sty for Young tableaux, typeset in JHEP style (HYPER VERSION); v2: references added (with corresponding comments

Nestmate Recognition in the Amazonian Myrmecophyte Ant Pseudomyrmex concolor Smith (Hymenoptera, Formicidae)

Nestmate recognition is fundamental to colonial cohesion in social insects, since it allows altruistic behavior towards relatives, recognition of intruders, territorial monopoly and resources defense. In ants, olfactory cues is a key factor in this process. Pseudomyrmex concolor is a highly aggressive ant that defends their host plant Tachigali myrmecophila against herbivores. However, this defense depends on the ant ability to discriminate in order to treat differentially between  members of their own colony and intruders . In this study we investigated “whether” and “how” P. concolor recognizes nestmates from non-nestmates. We hypothesized that P. concolor is skillful in recognizing nestmates and tested it in field with experiments using nestmates and non-nestmates. Additionally, to test the efficiency of resident ants against intraspecific competition during colony foundation, we simulate the plant occupation by a competitor queen, introducing non-nestmates queens in plants previously occupied by P. concolor. For the issue of the "how", we hypothesized that the main cue used by this ant in nestmate recognition is olfactory signal. Thus, we tested adaptive threshold model, which predicts that, if the individual odor and colony’s internal template are discrepant enough, the resident nestmate will behave aggressively towards incoming individuals. In this case, we confined nestmates with non-nestmates odors, and then, we reintroduced them in its host plants. In each experiment the frequency of aggressive behaviors were recorded and compared. Results showed that P. concolor recognize and discriminate nestmates from non-nestmates workers (biting and stinging them) and exclude potential competitors queens. Workers reintroduced in their own colony after impregnated with non-familiar odor were treated as non-nestmates. The adaptive threshold hypothesis was confirmed, the main cue used by this ant species in nestmate recognition is olfactory signals