1,088 research outputs found
Variation in pre-laying behaviour of hens : implications for control and motivation
Considerable variation in pre-laying behaviour of domestic hens (Gallus gcillus
domesticus) is observed within individuals, between individuals and between different
husbandry systems. The contributions o f internal and external factors to this variation
were considered. Part o f this variation is in relative amounts o f searching and nesting,
so criteria were defined to separate pre-laying behaviour into a searching and sitting
phase.The main internal factors considered related to lag and position o f eggs in sequences.
The duration o f the sitting phase and the total time spent in the nest box was related to
lag. The duration o f pre-laying behaviour was longer for the first egg o f a sequence
than for the other eggs. This was mainly due to a longer searching phase in which hens
performed more nest examinations. The duration of the sitting phase was longer for the
last egg o f a sequence than for other eggs; this may have been related to a longer lag
found for the last egg.Effects o f competing behavioural tendencies on pre-laying behaviour involve both
internal and external factors. A series o f experiments was conducted to investigate the
performance o f pre-laying behaviour while altering the availability o f food and
motivation to feed (length of food deprivation). Hens always interrupted their prelaying behaviour in order to feed when food was presented. Length o f deprivation did
not influence the duration o f feeding or pre-laying behaviour, that is, even "satiated"
hens stopped their pre-laying behaviour and fed. However, the delay in oviposition was
found to be greater when food was presented in the later, rather than the earlier, stages
of pre-laying behaviour. The duration o f pre-laying behaviour and o f the searching
phase was longer if hens were food deprived than if food was available. These findings
suggests that the expression o f pre-laying behaviour is determined by the tendency to
perform pre-laying behaviour competing with other behavioural tendencies.External factors examined included the effects o f conditions that facilitate searching
and nesting behaviour on pre-laying behaviour. Hens provided with an unlittered nest
box showed an extended pre-laying behaviour and searching phase, more searching
behaviour and nest examinations and more nest entries o f a shorter duration than when
provided with a littered nest box. These results suggested that in the absence o f a
suitable nest site, hens delayed, and showed an incomplete transition from searching to
nesting behaviour. Providing an exploratory walkway to facilitate searching behaviour
resulted in the searching phase starting earlier than expected, and in the occurence of
more searching behaviour and nest examinations during this time. Environments that
facilitate searching behaviour may provide external cues that allow the motivation to
perform pre-laying behaviour to be expressed earlier than in barren environments.The strength o f hens' motivation to reach a nest box was assessed with the aid of
aversive stimuli. Hens were required to pass through an empty corridor, or past a
dominant, subordinate or unfamiliar hen to reach a nest box. Hens delayed their
approach to the nest box and made more attempts to find alternative routes to the nest
box when required to pass a dominant or unfamiliar hen. Thus social factors were
found to influence access to the nest site and pre-laying behaviour. Hens appeared to
be only weakly motivated to reach the nest site during the searching phase; motivation
to reach the nest site increased near the start o f the sitting phase.The effects o f social interactions on access to a nest site and on the pre-laying
behaviour of hens in small groups was investigated. Evidence o f competition for the
nest site was found when more than one hen was showing pre-laying behaviour.
Subordinate hens walked more in the last hour before oviposition and sat less in the
last 25 minutes when other hens were also showing pre-laying behaviour than when no
other hens were in the pre-laying phase. Dominant hens in the pre-laying phase
remained nearer the nest when other hens were showing pre-laying behaviour than
when none were doing so. Thus social interactions during the pre-laying phase result in
variation in pre-laying behaviour in both directions; subordinate hens do not settle into
the expected nesting phase whereas dominant hens stay nearer the nest.A motivational theory o f pre-laying behaviour is proposed in which pre-laying
behaviour is controlled by an interaction between the tendencies to perform searching
and nesting behaviour. The tendency to start searching behaviour is influenced by
internal factors, competition between motivational systems and external cues for
exploration. The tendency to start nesting behaviour is influenced by the availability o f
a suitable nest site and social factors. It is suggested that a certain amount o f
behavioural priming is normally required before oviposition can occur. The
implications o f this model for the welfare of laying hens is discussed
Byron and Álvares de Azevedo: Byronism in Brazil
This research consists of a study of two major Romantic poets: Lord Byron from Great Britain and Álvares de Azevedo from Brazil. It discusses the link between the poetical movement of Romanticism in Brazil and in Great Britain, showing how European Romanticism was received and practiced in Brazil especially focusing on the image of Byron as the disillusioned and macabre hero to inspire the Brazilian. Chapters include The Social Context in the Romantic Brazil, Romanticism in Brazil, The Epicurus Society and Life in São Paulo, Byron and Álvares de Azevedo, and Byron Translated.
Romanticism in Brazil played a key role on defining a national cultural and literary identity in the recently independent country that was Brazil. In its foundation, however, it still dialogued with many European countries such as Britain, France and even Portugal in order to create, shape and cultivate its own culture. Brazilian Romanticism assumed distinct voices throughout the nineteenth century; this thesis is developed considering the existence of three generations of poets and focusing on the second or intermediate generation, mainly known as ‘the Byronic generation.’ The main characteristics of the Byronic generation were associated with the principal features of Lord Byron’s poetry or life for the Brazilian: individualism and subjectivism, doubt, disillusionment, melancholy, pessimism, cynicism and bohemian negativism.
Amongst Brazil’s prominent authors of the period is Álvares de Azevedo (1831-1852) – the foremost Brazilian Byronist. Azevedo is the most popular amongst his contemporaries - and also amongst twentieth century Brazilian writers. Azevedo’s life and writing related to the type of dark and satanic imaginary associated with Byronism in Brazil showing him to be one of the best interpreters and disciples of Byron.
The findings underline that the image of Byron seems to have played a key role in the formation and development of a national literature. Although Byron was still a European author, he had his image and work adapted to suit the Brazilian literary ideas and interests. Byron’s work and life assumed mythical proportions when they were brought together into the image of his heroes such as Don Juan, Childe Harold, and Manfred, by his Brazilian readers and translators. Thus, although Brazilian Romanticism is generally understood as a blend of all things from European Romanticism, it was, however, adapted by the hands of Brazilian writers to a ‘local colour’ corresponding to their literary project.
The thesis was developed with the hopes of being continued in the future as part of a PhD project involving other poets, and it could be published as an introductory volume in English to the study of Brazilian Romanticism and its relation to Byron. The volume could perhaps place Brazilian Romanticism in a place of recognition and stature in the international literary canon. As the research has shown, Brazilian Romanticism – although a very distinctive and important literary movement with strong European roots – has been neglected by a canon predominantly consisted of European authors
Trust and political orientations
This paper discuss the rebirth of trust studies in recent years, especially in the field of political attitudes and opinions. The case study presented try to explore the relationship between electoral behaviour and political orientations, regarding the people's views about the role of state, market and 'third sector' and application of law or social self-regulation. We found prevailing statists and liberal orientations, but also a 'concealed' group of Portuguese voters
Quantifying joint behavioral states in zebrafish (Danio rerio) dyadic contests through interpretable variables
Tese de Mestrado, Engenharia Biomédica e Biofísica, 2021, Universidade de Lisboa, Faculdade de CiênciasO comportamento animal é uma área fascinante do ponto de vista físico, no entanto ainda existem vários desafios associados à construção de modelos ou ao desenvolvimento de teorias do comportamento em física. Um dos desafios é desenvolver modelos diretamente dos dados, eliminando o viés antropocêntrico que existe na definição de estados comportamentais. Um bom exemplo da complexidade associada ao comportamento pode ser encontrado em interações sociais, nomeadamente interações agonistas entre peixes-zebra (Danio rerio). Estas interações são bem compreendidas e estereotípicas, e existem catálogos a descrever os estados comportamentais associados a cada fase da interação. Isto e a versatilidade genética a que o peixe zebra se encontra associado, tornam esta interação ideal para o nosso estudo. O nosso objetivo principal consiste na tentativa de derivar um conjunto de estados comportamentais diretamente a partir dos dados experimentais obtidos, sendo estes estados definidos para o conjunto, e não individualmente. Fazemos isso sob a assunção de em interações sociais, estados comportamentais dependem dos elementos envolvidos nessa interação (neste caso, são peixes-zebra) e que esta não é completamente descrita, exceto se levar ambos em conta simultaneamente. Os dados são esqueletos tridimensionais dos 2 peixes-zebra num volume. O processo de aquisição desses dados consiste na aquisição de imagens em 3 planos bidimensionais com câmaras de alta definição, e um pipeline de processamento, que combina várias redes neuronais para a identificação de pontos corporais, a atribuição de identidade temporal aos peixes envolvidos, e a interpolação das imagens nos diferentes planos. Este processo permite a conversão de vários vídeos em sinais temporais que podem ser manipulados e processados de forma adequada. Usamos variáveis interpretáveis, no caso, a distância, os alinhamentos de direcção e aceleração, e os ritmos de batimento de cauda. Essas variáveis embora sejam simples, podem dizer bastante informação sobre a natureza do comportamento, sendo úteis numa exploração inicial. Definimos estados comportamentais compostos (colecção de vários comportamentos efectuados pelos peixes ao longo de um determinado período de tempo) e exploramos a dinâmica de uma luta nesta descrição simplificada. O sistema que resulta das variáveis definidas possui 6 dimensões, projectamos esse sistema para um plano bidimensional para melhor análise. Efectua-se um histograma das novas variáveis, e ter uma estimativa da densidade de probabilidade através da convolução do mesmo com uma gaussiana bidimensional. Detecta-se os picos de densidade, que neste sistema podem ser interpretados como estados comportamentais. Com essa descrição é possível gerar uma sequência simbólica que representa a dinâmica da interacção como sendo a transição entre vários estados comportamentais discretos. Constrói-se uma matriz que representa a transição entre os vários estados, e por decomposição espectral pode-se observar o comportamento dos valores próprios em função do número de transições e é possível decompor os estados em vários conjuntos através dos vectores próprios, cuja dinâmica entre eles é representada pelo valor próprio associado. Através da sequência simbólica é possível uma descrição da interacção entre os elementos, tendo inclusive informação sobre a escala temporal associada à dinâmica entre esses estados. Ao associar os clusters aos diferentes estados comportamentais compostos definidos previamente, é possível ver que certos clusters se encontram associados, e apresenta uma certa estrutura, que pode ser representativa da dinâmica real. Também é possível determinar a escala temporal de interações entre diferentes conjuntos de clusters. Foi possível determinar que os comportamentos ocorrem em escalas temporais maiores do que a escala típica para processo de Markov, e a escala temporal mais elevada se encontra associada a transição entre estados associados à agressão entre o par, e estados associados aos períodos entre lutas. Mostramos que é possível obter uma estrutura comportamental da luta entre dois peixes-zebra utilizando as variáveis simples que definimos. Isto é um framework que permite explorar a dinâmica da sua interação em maior detalhe, a utilizar variáveis ou representações mais precisas, que podem não ser interpretáveis
Are chicken minds special?
The number of publications on chicken cognition and emotion exceeds that on most birds and is comparable to the number of publications on some more “advanced” mammals. We argue that the chicken is an excellent model for this type of research because of (1) the presence of well-established fundamental mental processes in the chicken, (2) a challenging ethological environment and (3) social pressures that may have facilitated the evolution of cognitive abilities similar to those of some mammals. Marino’s (2017) review provides an excellent foundation for the continued study of complex mental abilities in this species
Exfoliation microcracks in building granite. Implications for anisotropy
Granite is found in many world heritage monuments and cities. It continues to be one of the most widely used stones in today's construction, given its abundance, uniformity and durability. Quarrymen traditionally cut this rock along its orthogonal slip planes, where splitting is easier. Ranked by ease of splitting, these planes are rift, grain and hardway. Granite is traditionally quarried along the rift plane where coplanar exfoliation microcracks coalesce developing a flat surface. This splitting surface minimizes the cost and effort of subsequent hewing. Rift plane was predominantly used on the fair face of ashlars in heritage buildings worldwide. Determining the petrographic and petrophysical behaviour of these three orthogonal splitting planes in granite is instrumental to understanding decay in ashlars and sculptures. The decay of building granite is different in each splitting plane.
Alpedrete granite was the stone selected for this study based on the orientation and distribution of exfoliation microcracks and the characterisation of their implications for the anisotropy of petrophysical properties such as ultrasonic wave propagation, capillarity, air permeability, micro-roughness and surface hardness. Inter- and intracrystalline microcrack length and spacing were also measured and quantified.
The findings show that the splitting planes in Alpedrete granite are determined by the orientation of exfoliation microcracks, which as a rule are generally straight and intracrystalline and determine the anisotropy of the petrophysical properties analysed.
Splitting planes are the orientation that should be applied when performing laboratory tests for the petrographic and petrophysical properties of building granite.This study was funded by the Regional Government of Madrid, Spain, in the framework of the GEOMATERIALS-2CM [S2013/MIT-2914] programme.Peer reviewe
Causes of scaling on bush-hammered heritage ashlars: a case study—Plaza Mayor of Madrid (Spain)
Masons have traditionally used granite anisotropy to cut and lay the stone. Scaling, a common type of granite decay, is observed worldwide. This study explored the relationship between weathering and cut planes in heritage ashlars, specifically in the stone on Madrid’s Plaza Mayor, whose construction dates back to 1590. The 71 rectangular granite columns that support its porticoes are oriented towards the four cardinal points. All 71 have one exposed side that faces the square, one protected side facing inward and two semi-protected sides perpendicular to the other two. The sides of the columns are also oriented to the points of the compass. This study aimed to identify the prevailing orientation of scaling, if any, in the granite ashlars and to determine how this process is affected by climate, microclimate (orientation), use, hewing and exfoliation microcracks. All four sides of the 71 columns were mapped (284 in all) to analyse scaling height, distribution and orientation. The findings showed that the microcracks are vertically oriented and decline in density and length with depth from the surface. Scaling was observed on the lower ashlars in the columns to a maximum depth of 3 mm. Determining the direction of exfoliation microcracks is imperative to understanding decay mechanisms in granite ashlars and sculptures and that information must be taken into consideration when applying conservation treatments.This study was funded by the Community of Madrid under the GEOMATERIALS (S2009/MAT-1629) and GEOMATERIALS-2CM (S2013/MIT-2914) research programmes and Project 921349 awarded to the Complutense University of Madrid’s Research Group ‘Alteración y Conservación de los Materiales Pétreos del Patrimonio’Peer reviewe
Thermal stress-induced microcracking in building granite
Microcracking induced by wide fluctuations in temperature affects granite quality and durability, making the stone more vulnerable to decay. Determining the extent of that effect is not always straightforward, however, given the excellent durability of these materials.
Four types of construction granite quarried in the region of Madrid, Spain, and frequently used in both the built heritage and in de novo construction (Alpedrete, Cadalso de los Vidrios, Colmenar Viejo and Zarzalejo) were exposed to 42 thermal cycles (105–20 °C; UNE-EN, 14066, 2003). Petrographic and petrophysical properties were analysed using both destructive and non-destructive techniques. Microcracking generated in the granite stones by 42 thermal cycles had barely any impact on their petrophysical properties, which are the parameters normally assessed to establish material quality and durability. Their petrographic properties, which are not generally assessed in this type of studies, were affected, however. This study contends that petrographic analysis is needed to objectively quantify the actual quality and durability of the most highly resistant materials when petrophysical studies are inconclusive. Petrographic and fluorescence microscopy, along with fractography, are among the most prominent techniques for petrographic exploration. Thanks to the deployment of these techniques, mineral microcracking could be monitored throughout the present tests conducted.
The microscopic findings revealed substantial micro-textural and microstructural change in and around the granite minerals, which play a prominent role in decay. The findings showed that pre-existing microcracks coalesced and generated further microcracking as decay progressed. Microcracking was most intense in Zarzalejo granite due to its textural characteristics determined by its high feldspar content. Microscopic observation revealed that the microstructure of feldspar minerals, with their crystallographic anisotropies and secondary mineral phases, favoured microcrack development. Zarzalejo granite exhibited lower quality and durability than Colmenar Viejo and Cadalso de los Vidrios granites, which were more resistant to heat treatment.This study was funded by the project GEOMATERIALES 2 (S2013/MIT-2914).Peer reviewe
Heritage Stone 4. The Piedra Berroqueña Region: Candidacy for Global Heritage Stone Province Status
The Piedra Berroqueña region in the Guadarrama Mountains, part of Spain’s Central Range, supplies most of the construction granite used in Madrid and surrounding provinces. The region’s quarrying towns preserve their granite extraction and hewing traditions. Historic quarries form part of the landscape, as do current extraction sites with huge reserves that guarantee a speedy supply of variously finished dimension stone. Piedra Berroqueña granite has been in use as a construction material since long before Roman times. Many important monuments, including San Lorenzo Royal Monastery at El Escorial (1563−1584), Madrid’s Royal Palace (1738−1764), the Alcalá Gate (1770−1778), the Prado Museum (1785−1808) and Puerta del Sol (one of Madrid’s main squares), owe their good state of preservation to the stone’s petrophysical characteristics and durability. The granite is also found in most of the city’s housing and streets, as well as in modern buildings the world over, such as the airport terminals at Athens and Cork, and the British consulate at Hong Kong. Four major types of monzogranite occur including: biotitic monzogranites containing some cordierite, biotitic monzogranites containing some amphibole, biotitic monzogranites having no cordierite or amphibole, and leucogranites. The petrological, petrophysical and chemical properties of Piedra Berroqueña, which afford it great durability, vary little from one variety to another and depend on the degree of alteration. Physical and chemical characteristics were determined for five granites representative of historic or active quarries in the Piedra Berroqueña region: Alpedrete (monzogranite containing cordierite); Cadalso de los Vidrios (leucogranite); La Cabrera (monzogranite containing amphibole); Colmenar Viejo (monzogranites containing cordierite) and Zarzalejo (monzogranites having no cordierite or amphibole). The Piedra Berroqueña region meets the requirements of a Global Heritage Stone Province, and this paper supports the Piedra Berroqueña region's application for recognition as such. This distinction would enhance public awareness of an area committed to quarrying and working the local stone.RÉSUMÉLa région de Piedra Berroqueña dans les monts de Guadarrama, qui fait partie de la chaine centrale d'Espagne, est la principale source du granite de construction utilisé à Madrid et dans les provinces environnantes. Les agglomérations de la région qui exploitent une carrière conservent leur tradition d’extraction et de taille du granite. Les anciennes carrières font maintenant partie du paysage, comme les sites d'extraction actuels avec d'énormes réserves ce qui garantit un approvisionnement rapide en pierre de taille de fini varié. Le granite de Piedra Berroqueña a été utilisé comme matériau de construction bien avant l'époque romaine. De nombreux monuments importants, y compris le monastère royal de San Lorenzo à l'Escurial (1563–1584), le palais royal de Madrid (1738–1764), la porte d'Alcalá (1770–1778), le musée du Prado (1785–1808) et la Puerta del Sol (une des principales places de Madrid), doivent leur bon état de conservation aux caractéristiques pétrophysiques et à la durabilité de la pierre. Ce granite se retrouve également dans la plupart des habitations et des rues de la ville, ainsi que dans des bâtiments modernes du monde entier, tels que les terminaux de l'aéroport d'Athènes et de Cork, et le consulat britannique à Hong Kong. Il est constitué de quatre grandes classes de monzogranite : des monzogranites à biotite contenant un peu de cordiérite, des monzogranites à biotite contenant un peu d’amphibole, des monzogranites à biotite ne contenant ni cordiérite ni amphibole, et les leucogranites. Les propriétés pétrographiques, pétrophysiques et chimiques des granites de Piedra Berroqueña qui leur assurent une grande durabilité, varient peu d'une variété à l'autre et dépendent du degré d'altération. Les caractéristiques physiques et chimiques ont été déterminées sur cinq granites représentatifs des carrières historiques et actives de la région de Piedra Berroqueña : Alpedrete (monzogranite à cordiérite); Cadalso de los Vidrios (leucogranite); La Cabrera (monzogranite à amphibole); Colmenar Viejo (monzogranite à cordiérite); et Zarzalejo (monzogranite sans cordiérite ni amphibole). La région Piedra Berroqueña répond aux critères d'une Province pétrologique du patrimoine mondial, et le présent article documente la candidature de la région de Piedra Berroqueña à cet effet. Cette distinction permettrait d'améliorer la sensibilisation du public concernant une région spécialisée dans l’extraction et à la taille de la pierre locale. Traduit par le Traducteu
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