<p> Detailed Neodymium ( Nd ) and Lead ( Pb ) isotopic mapping was performed on gray gneisses from the Lac St. Jean region of Quebec, in the Central Grenville Province. The Nd model ages determined were based upon the Depleted Mantle Model of DePaolo ( 1981c ). The use of this model is justified by a Sm-Nd whole-rock isochron as well as common Pb-Pb whole-rock dating. </p> <p> The field area was divided up into three sections: Western, Central, and Eastern. The boundaries of these divisions corresponded to abrupt changes in Nd model ages. The Western section was located in the Parautochthonous Belt of Rivers et al., ( 1989 ) and almost exclusively consisted of tonalitic gray gneisses with Archean Nd model ages. Whole-rock Pb isotopic analyses produced a Transposed Palaeoisochron, implying that the rocks of the Western section were significantly affected by the Grenville event approximately 1.1 Ga ago. Major and trace element analyses indicate that the Western section represents an arc and may be the exhumed basement of the Abitibi Volcanic Belt to the north, consistent with previous work by Ciesielski ( 1992 ).</p> <p> In contrast to the Western section, the Central section which is separated from the Western section by the Allochthon Boundary Thrust of Rivers et al., ( 1989 ) has a very wide range of Nd model ages from 1.65 Ga to 2.35 Ga. The temporal and spatial range of Nd model ages, coupled with major and trace element analyses, indicates that the Central section represents an Andean style ensialic continental margin arc. The diapirs that reworked these rocks contain varying amounts of Archean material implied by the Early-Proterozoic Nd model ages of some samples, particularly in regions close to the Allochthon Boundary Thrust. Whole-rock Pb isotopic analyses produce a Transposed Palaeoisochron indicating significant U depletion caused by the Grenville orogeny.</p> <p> The Eastern section is composed almost exclusively of gneisses with Nd model ages of ca. 1.5 Ga. The boundary between the Central and Eastern sections is based solely on lithological differences and an isotopic age break form the variable Nd model ages of the Central section, to the consistent model ages of the Eastern section. A Sm-Nd isochron for all samples with ca. 1.5 Ga Nd model ages produces an age of 1.50 +/- 0.07 Ga, in close agreement with previous work ( Dickin and Higgins, 1992 ). The consistency of model ages ( > 100,000 Km^2 when combined with data from Dickin and Higgins, 1992 ) coupled with major and trace element analyses, indicates the presence of an island arc which formed at ca. 1.5 Ga and was sutured on to the Laurentian craton within 100 Ma of its formation.</p> <p> Whole-rock Pb isotope analyses indicate that the Eastern section was not affected by the Grenville event as much as the Central or Western sections were.</p> <p> Pb-Pb zircon dating for samples from the Central and Eastern sections failed to place a tight constraint between crystallization ages and Nd model ages because of excessive Pb loss.</p> / Thesis / Master of Science (MSc)

Yes / Age and gender classification are two important problems that recently gained popularity in the research community, due to their wide range of applications. Research has shown that both age and gender information are encoded in the face shape and texture, hence the active appearance model (AAM), a statistical model that captures shape and texture variations, has been one of the most widely used feature extraction techniques for the aforementioned problems. However, AAM suffers from some drawbacks, especially when used for classification. This is primarily because principal component analysis (PCA), which is at the core of the model, works in an unsupervised manner, i.e., PCA dimensionality reduction does not take into account how the predictor variables relate to the response (class labels). Rather, it explores only the underlying structure of the predictor variables, thus, it is no surprise if PCA discards valuable parts of the data that represent discriminatory features. Toward this end, we propose a supervised appearance model (sAM) that improves on AAM by replacing PCA with partial least-squares regression. This feature extraction technique is then used for the problems of age and gender classification. Our experiments show that sAM has better predictive power than the conventional AAM.

A região de Gondola-Nhamatanda localiza-se na parte limítrofe entre as províncias de Manica e Sofala, centro de Moçambique. Ela está geologicamente inserida no complexo de Bárue (Grupo de Chimoio) e na cobertura fanerozoica. O Complexo de Bárue é composto pelos Grupos supracrustais de Macossa e Chimoio intrudidos por rochas plutônicas de várias composições. Enquanto que a cobertura fanerozoica consiste de sedimentos terrestres e rochas vulcânicas associadas pertencentes ao Supergrupo do Karoo e à sequências do rifte Este Africano. A área de trabalho foi estudada em termos de petrografia; geoquímica de elementos maiores, traço e de terras raras; geocronologia e geologia isotópica pelos métdos U -Pb em zircão, Rb-Sr e Sm-Nd em rocha total e Rb-Sr em minerais para o granito de Inchope, quartzo-sienito do monte Chissui e fonolito do monte Xiluvo. Este estudo permitíu determinar os litotipos que intrudiram o grupo supracrustal de Chimoio , suas idades de cristalização e de diferenciação dos magmas que formaram seus protólitos e ainda o enquadramento tectônico. As rochas estudadas são basicamente calci -alcalinas com variações de meta à peraluminoso para os granitoides e quartzo-sienito e peralcalino para o fonolito do monte Xiluvo. Os granitoides do grupo de Chimoio foram cristalizados no Mesoproterozoico (idades U-Pb e Rb-Sr) a partir de protólitos Paleoproterozoicos (\'T IND.DM\' = 1,7 - 2,3 Ga); por sua vez, as rochas vulcânicas (fonolitos) do monte Xiluvo cristalizaram rápidamente no Câmbrico (idade Rb-Sr) dum protólito do Neoproterozoico-Câmbrico (\'T IND.DM\' = 0,54 - 0,56 Ga). Os dados isotópicos obtidos no presente estudo sugerem que as rochas do cinturão de Moçambique foram geradas por fusão parcial que provavelmente envolveu mistura ( valores negativos de ?Nd ) da crosta arqueana / paleoproterozoica e magma mesoproterozoico a 1100 Ma e sofreram retrabalhamento marcado pela aglutinação do Gondwana (orogenia Pan-Africana) e tafrogênese marcada pela fraturação do Gondwana (Rifte Este Africano ). / The region of Gondola-Nhamatanda is located at the border between the provinces of Manica and Sofala, central part of Moçambique. It is geologically inserted in the Bárue complex and the Phanerozoic cover. The Bárue complex is composed of the Macossa and Chimoio supracrustal groups intruded by plutonic rocks of various compositions, whereas the Phanerozoic cover consists of terrestrial sediments and volcanic rocks belonging to the Karoo Super-group and East African Rift Sequences. The work area was studied in terms of petrography; geochemistry of major elements, trace and rare earth elements; geochronology and isotope geology by the methods U -Pb in zircon, Rb-Sr and Sm-Nd in whole rock and Rb-Sr in minerals for the Inchope granite, Chissui mountain Quartzo-sienito and Xiluvo mountain phonolite. This study allowed to determine the lithotypes that intruded the Chimoio supracrustal group, its crystallization ages and the differentiation ages of the magmas that formed the protoliths and the tectonic framework. The studied rocks are basically calc-alkaline varying from meta to peraluminous for the granitoids and quartz-sienite and peralkaline for the mount Xiluvo phonolite. The Chimoio Group granitoids had been crystallized in the Mesoproterozoic (U-Pb and Rb-Sr ages) from Paleoproterozoic protoliths (\'T IND.DM\' = 1.7 - 2.4Ga); on the other hand, the volcanic rocks (phonolites) of the Xiluvo mount had crystallized fast in the Cambrian (Rb-Sr age) from a Neoproterozoic-Cambrian protolith (\'T IND.DM\' = 0.54 - 0.56Ga). The isotopic data, in the present study , suggest that the rocks of the Mozambique belt had been generated by partial melting that probably involved the mixture of the archean/paleoproterozoic crust and the Mesoproterozoic magma at 1100Ma and had suffered reworking marked by the Gondwana amalgamation (Pan-African orogeny) and extensional processes marked by the Gondwana break up (East African Rift).

A parte central de Moçambique foi marcada por eventos episódicos consistindo de granitogênese mesoproterozóico e neoproterozóico, magmatismo neoproterozóico, sedimentação neoproterozóica e magmatismo cambriano. Estes eventos produziram unidades geológicas cujas relações espaciais e temporais tem sido controversas no que se refere à Suíte de Guro e ao Complexo de Bárue. Alguns autores defendem a existência de duas unidades geológicas distintas e outros incorporavam a Suite de Guro no Complexo de Bárue formando assim uma e única unidade geológica. Dentro deste contexto este trabalho tenta dar uma melhoria no modelo geocronológico/tectônico das rochas graníticas do Complexo de Bárue e da Suíte de Guro utilizando dados geocronológicos U-Pb SHRIMP em zircão e idades Sm-Nd modelo manto empobrecido (\'T IND.DM\' ), caracterizando as suas respectivas fontes e evoluções tectono-magmáticas com base na geoquímica isotópica Sr e Nd em rocha total e em dados litogeoquímicos em rocha total. Estes dados em conjunto com as informações geológicas e geocronológicas disponíveis na literatura permitiram modelar a evolução da crosta continental da região central de Moçambique. O modelo proposto aponta para eventos de cristalização magmática mesoproterozóico, neoproterozóico e cambriano e de sedimentação neoproterozóico. Em adição, apartir dos dados obtidos e das informações das ocorrências minerais disponíveis para a área de estudo, foi feita a correlação dos processos ígneos e metamórficos relacionados à evolução tectono-magmática dos granitóides com as suas respectivas especializações metalogenêticas, visando o estabelecimento de critérios de prospectividade regional para exploração mineral. Alguns eventos relacionados com intrusão de veios pegmatíticos e alteração de rochas pré-existentes são responsáveis pelas mineralizações na área de estudo. / The central part of Mozambique was marked by Mesoproterozoic and Neoproterozoic granite genesis events followed by Neoproterozoic sedimentation events and Cambrian magmatism. These events produced geological units whose spatial relationship has been controversial in regard to the Guro Suite and the Bárue Complex. Some authors advocate the existence of two distinct geological units and other embodied the Guro Suite in the Bárue complex thus forming one and the same geological unit. Within this context, this work tries to give an improvement in geochronological pattern of granitic rocks of the Bárue Magmatic Arc and Guro Suite using geochronological U-Pb SHRIMP data on zircons and Sm-Nd depleted mantle model ages (\'T IND.DM\'), characterizing their respective sources and tectonic-magmatic evolution based on whole rock Sr and Nd isotope geochemistry and whole rock Lithogeochemical data. These data together with the geological and geochronological data available in the literature allowed modeling the evolution of the continental crust of central Mozambique. The proposed model points to Mesoproterozoic, Neoproterozoic, and Cambrian magmatic crystallization events and followed by Neoproterozoic sedimentation. In addition, from the obtained data and information of mineral occurrences available for the study area, the correlation of igneous and metamorphic processes related to tectonic and magmatic evolution of the granitoids with their respective metallogenetic specialization was made, aiming to establish a regional prospective solutions for mineral exploration. Some events related to pegmatitic veins intrusion and alteration of preexisting rocks are responsible for the mineralization in the study area.

A parte central de Moçambique foi marcada por eventos episódicos consistindo de granitogênese mesoproterozóico e neoproterozóico, magmatismo neoproterozóico, sedimentação neoproterozóica e magmatismo cambriano. Estes eventos produziram unidades geológicas cujas relações espaciais e temporais tem sido controversas no que se refere à Suíte de Guro e ao Complexo de Bárue. Alguns autores defendem a existência de duas unidades geológicas distintas e outros incorporavam a Suite de Guro no Complexo de Bárue formando assim uma e única unidade geológica. Dentro deste contexto este trabalho tenta dar uma melhoria no modelo geocronológico/tectônico das rochas graníticas do Complexo de Bárue e da Suíte de Guro utilizando dados geocronológicos U-Pb SHRIMP em zircão e idades Sm-Nd modelo manto empobrecido (\'T IND.DM\' ), caracterizando as suas respectivas fontes e evoluções tectono-magmáticas com base na geoquímica isotópica Sr e Nd em rocha total e em dados litogeoquímicos em rocha total. Estes dados em conjunto com as informações geológicas e geocronológicas disponíveis na literatura permitiram modelar a evolução da crosta continental da região central de Moçambique. O modelo proposto aponta para eventos de cristalização magmática mesoproterozóico, neoproterozóico e cambriano e de sedimentação neoproterozóico. Em adição, apartir dos dados obtidos e das informações das ocorrências minerais disponíveis para a área de estudo, foi feita a correlação dos processos ígneos e metamórficos relacionados à evolução tectono-magmática dos granitóides com as suas respectivas especializações metalogenêticas, visando o estabelecimento de critérios de prospectividade regional para exploração mineral. Alguns eventos relacionados com intrusão de veios pegmatíticos e alteração de rochas pré-existentes são responsáveis pelas mineralizações na área de estudo. / The central part of Mozambique was marked by Mesoproterozoic and Neoproterozoic granite genesis events followed by Neoproterozoic sedimentation events and Cambrian magmatism. These events produced geological units whose spatial relationship has been controversial in regard to the Guro Suite and the Bárue Complex. Some authors advocate the existence of two distinct geological units and other embodied the Guro Suite in the Bárue complex thus forming one and the same geological unit. Within this context, this work tries to give an improvement in geochronological pattern of granitic rocks of the Bárue Magmatic Arc and Guro Suite using geochronological U-Pb SHRIMP data on zircons and Sm-Nd depleted mantle model ages (\'T IND.DM\'), characterizing their respective sources and tectonic-magmatic evolution based on whole rock Sr and Nd isotope geochemistry and whole rock Lithogeochemical data. These data together with the geological and geochronological data available in the literature allowed modeling the evolution of the continental crust of central Mozambique. The proposed model points to Mesoproterozoic, Neoproterozoic, and Cambrian magmatic crystallization events and followed by Neoproterozoic sedimentation. In addition, from the obtained data and information of mineral occurrences available for the study area, the correlation of igneous and metamorphic processes related to tectonic and magmatic evolution of the granitoids with their respective metallogenetic specialization was made, aiming to establish a regional prospective solutions for mineral exploration. Some events related to pegmatitic veins intrusion and alteration of preexisting rocks are responsible for the mineralization in the study area.

A região de Gondola-Nhamatanda localiza-se na parte limítrofe entre as províncias de Manica e Sofala, centro de Moçambique. Ela está geologicamente inserida no complexo de Bárue (Grupo de Chimoio) e na cobertura fanerozoica. O Complexo de Bárue é composto pelos Grupos supracrustais de Macossa e Chimoio intrudidos por rochas plutônicas de várias composições. Enquanto que a cobertura fanerozoica consiste de sedimentos terrestres e rochas vulcânicas associadas pertencentes ao Supergrupo do Karoo e à sequências do rifte Este Africano. A área de trabalho foi estudada em termos de petrografia; geoquímica de elementos maiores, traço e de terras raras; geocronologia e geologia isotópica pelos métdos U -Pb em zircão, Rb-Sr e Sm-Nd em rocha total e Rb-Sr em minerais para o granito de Inchope, quartzo-sienito do monte Chissui e fonolito do monte Xiluvo. Este estudo permitíu determinar os litotipos que intrudiram o grupo supracrustal de Chimoio , suas idades de cristalização e de diferenciação dos magmas que formaram seus protólitos e ainda o enquadramento tectônico. As rochas estudadas são basicamente calci -alcalinas com variações de meta à peraluminoso para os granitoides e quartzo-sienito e peralcalino para o fonolito do monte Xiluvo. Os granitoides do grupo de Chimoio foram cristalizados no Mesoproterozoico (idades U-Pb e Rb-Sr) a partir de protólitos Paleoproterozoicos (\'T IND.DM\' = 1,7 - 2,3 Ga); por sua vez, as rochas vulcânicas (fonolitos) do monte Xiluvo cristalizaram rápidamente no Câmbrico (idade Rb-Sr) dum protólito do Neoproterozoico-Câmbrico (\'T IND.DM\' = 0,54 - 0,56 Ga). Os dados isotópicos obtidos no presente estudo sugerem que as rochas do cinturão de Moçambique foram geradas por fusão parcial que provavelmente envolveu mistura ( valores negativos de ?Nd ) da crosta arqueana / paleoproterozoica e magma mesoproterozoico a 1100 Ma e sofreram retrabalhamento marcado pela aglutinação do Gondwana (orogenia Pan-Africana) e tafrogênese marcada pela fraturação do Gondwana (Rifte Este Africano ). / The region of Gondola-Nhamatanda is located at the border between the provinces of Manica and Sofala, central part of Moçambique. It is geologically inserted in the Bárue complex and the Phanerozoic cover. The Bárue complex is composed of the Macossa and Chimoio supracrustal groups intruded by plutonic rocks of various compositions, whereas the Phanerozoic cover consists of terrestrial sediments and volcanic rocks belonging to the Karoo Super-group and East African Rift Sequences. The work area was studied in terms of petrography; geochemistry of major elements, trace and rare earth elements; geochronology and isotope geology by the methods U -Pb in zircon, Rb-Sr and Sm-Nd in whole rock and Rb-Sr in minerals for the Inchope granite, Chissui mountain Quartzo-sienito and Xiluvo mountain phonolite. This study allowed to determine the lithotypes that intruded the Chimoio supracrustal group, its crystallization ages and the differentiation ages of the magmas that formed the protoliths and the tectonic framework. The studied rocks are basically calc-alkaline varying from meta to peraluminous for the granitoids and quartz-sienite and peralkaline for the mount Xiluvo phonolite. The Chimoio Group granitoids had been crystallized in the Mesoproterozoic (U-Pb and Rb-Sr ages) from Paleoproterozoic protoliths (\'T IND.DM\' = 1.7 - 2.4Ga); on the other hand, the volcanic rocks (phonolites) of the Xiluvo mount had crystallized fast in the Cambrian (Rb-Sr age) from a Neoproterozoic-Cambrian protolith (\'T IND.DM\' = 0.54 - 0.56Ga). The isotopic data, in the present study , suggest that the rocks of the Mozambique belt had been generated by partial melting that probably involved the mixture of the archean/paleoproterozoic crust and the Mesoproterozoic magma at 1100Ma and had suffered reworking marked by the Gondwana amalgamation (Pan-African orogeny) and extensional processes marked by the Gondwana break up (East African Rift).

The main aim of this thesis is to analyse different mortality models regarding the longevity risk. We focus on the well-known stochastic models (Lee-Carter model, Age-period-cohort model by Renshaw and Haberman, Cairns-Blake-Dowd two-factor model) and compare them with relatively new Taiwanese model by Yang, Yue and Huang which is based on principal component analysis. Both the theoretical and also the empirical parts are included. Empirical part evaluates all the models mentioned above on the Czech mortality data from 1970-2000 for individuals aged between 50-100 years. Final mortality predictions are made for next 30 years.

Les conditions oxydantes de la surface terrestre actuelle sont dues à la teneur élevée en dioxygène de l’atmosphère. Au début de l’histoire de la Terre il y a 4.54 milliards d'années (Ga), l’oxygène n’était pas stable dans l’atmosphère. Il a fallu deux épisodes d’augmentation brutale de ce gaz atmosphérique pour qu’il atteigne son niveau actuel : l’un vers 2.4 Ga, nommé le Grand Evènement Oxydant (GOE) qui fait l’objet de ce projet, l’autre 2 milliards d’années plus tard, nommé l’Evènement Oxydant Néo-protérozoïque (NOE). Le GOE est vraisemblablement le résultat de l’émersion généralisée de larges continents dont l’érosion libère le phosphate dans l’océan, un nutriment nécessaire à la production biologique, qui a donc permis l’explosion de la photosynthèse oxygénée. Ces deux hausses d’oxygène atmosphérique coïncident avec deux évolutions majeures dans l’histoire de la vie : (i) peu après le GOE, les eucaryotes sont apparus, alors que (ii) le NOE correspond à l’apparition des métazoaires et à l’explosion cambrienne. L’étude de ces phénomènes atmosphériques primitifs peut avoir d’importantes répercussions sur notre compréhension de l’origine et de l’évolution de la vie, qu’on estime principalement marine à cet âge. Les seules archives de ces temps primitifs sur Terre sont les roches sédimentaires. Pour savoir comment l’oxygénation de l’atmosphère a pu être reliée à cette vie marine, il faut tout d’abord comprendre comment l’océan a interagi avec l’atmosphère lors de cet évènement d’oxygénation. Cette question est au coeur de ce projet : comment le GOE a-t-il affecté les cycles biogéochimiques océaniques dont la vie est dépendante ? Nous nous sommes intéressés aux formations ferrifères litées ou BIFs (Banded Iron Formations). La chimie de ces roches marines fait écho à celle de l’océan contemporain à leur formation. Déterminer quantitativement la composition de l’océan à partir de celles des sédiments, même chimiques, est un défi quasiment impossible à relever y compris dans l’océan moderne. C’est pourquoi nous avons proposé de déterminer le temps de résidence d’éléments sensibles aux conditions redox de la surface, le soufre, le fer et le cuivre dans l’océan pré-GOE. Nous avons obtenu, par des séries temporelles, le spectre des fluctuations isotopiques de ces éléments enregistrées dans des carottes de formations ferrifères litées. La limite inférieure du spectre donne le temps de résidence de ces éléments dans l’eau de mer et fournit donc une indication solide sur la teneur de ces éléments dans l’océan à cette période. Nous avons analysé des échantillons protérozoïques proches de la limite Archéen-Protérozoïque du Transvaal (Afrique du Sud) et d’Hamersley (Australie). Des échantillons eoarchéens de Nuvvuagittuq (Canada) ont été récoltés mais n'ont pas pu être analysés faute de temps. / The present-day oxidizing conditions at Earth's surface are due to the high oxygen content of the atmosphere. However, oxygen was not always stable in the terrestrial atmosphere. Two distinct periods during which oxygen increased in a step-like manner were required to reach the current atmospheric oxygen level. The first, at about 2.4 Ga, is known as the Great Oxidation Event (GOE) and is at the core of this Ph.D. thesis. The other, occurring almost two billion years later, is called the Neo-Proterozoic Oxidation Event (NOE). The GOE likely is the result of the beginning widespread emergence of large continental expanses whose subsequent erosion gradually released phosphate into the ocean. Phosphate, a nutrient essential to organic production, in turn allowed the explosion of oxygenated photosynthesis. The GOE and NOE coincide with two major changes in the history of life. Shortly after the GOE, eukaryotes appeared, while the NOE corresponds to the appearance of metazoans and the Cambrian explosion. A better grasp of the GOE hence may have important implications for the understanding of the origin and evolution of life, which is thought to have been mainly marine at this stage in Earth history. The only records of the oxygen level during these ancient times are found in terrestrial sedimentary rocks. To understand how oxygenation of the atmosphere relates to marine life, we must first understand how the ocean was connected to the atmosphere during the GOE and how the GOE affected life-dependent ocean biogeochemical cycles. To this end we focused on banded iron formations (BIF). The chemistry of these sedimentary marine rocks directly reflects the chemistry of the contemporary ocean. Deriving quantitatively the composition of the ocean from a hydrogenous sediment is a challenge almost impossible to meet, even for the modern ocean. This is why we instead determined the residence time of redox-sensitive elements (in this case sulfur, iron, and copper) in the pre-GOE ocean. We specifically targeted the periods of isotopic fluctuations in these elements as recorded in BIF cores. The lower limit of the spectrum provides the residence time of these elements in seawater, hence giving a robust indication of their contents in the pre-GOE ocean. We sampled early Proterozoic BIF near the Archean-Proterozoic boundary in Transvaal (South Africa) and Hamersley (Australia), as well as Archean BIF from Nuvvuagittuq (Canada), though the latter were not analyzed during this thesis due to shortage of time.

We investigate the biological constraints determined by the complex relationships between ecological and immunological processes of host-pathogen interactions, with emphasis on influenza viruses in human, which are responsible for a number of pandemics in the last 150 years. We begin by discussing prolegomenous reviews of historical perspectives on the use of theoretical modelling as a complementary tool in public health and epidemiology, current biological background motivating the objective of the thesis, and derivations of mathematical models of multi-locus-allele systems for infectious diseases with co-circulating serotypes. We provide detailed analysis of the multi-locus-allele model and its age-specific extension. In particular, we establish the necessary conditions for the local asymptotic stability of the steady states and the existence of oscillatory behaviours. For the age-structured model, results on the existence of a mild solution and stability conditions are presented. Numerical studies of various strain spaces show that the dynamic features are preserved. Specifically, we demonstrate that discrete antigenic forms of pathogens can exhibit three distinct dynamic features, where antigenic variants (i) fully self-organize and co-exist with no strain structure (NSS), (ii) sort themselves into discrete strain structure (DSS) with non-overlapping or minimally overlapping clusters under the principle of competitive exclusion, or (iii) exhibit cyclical strain structure (CSS) where dominant antigenic types are cyclically replaced with sharp epidemics dominated by (1) a single strain dominance with irregular emergence and re-emergence of certain pathogenic forms, (2) ordered alternating appearance of a single antigenic type in periodic or quasi-periodic form similar to periodic travelling waves, (3) erratic appearance and disappearance of synchrony between discrete antigenic types, and (4) phase-synchronization with uncorrelated amplitudes. These analyses allow us to gain insight into the age-specific immunological profile in order to untangle the effects of strain structures as captured by the clustering behaviours, and to provide public health implications. The age-structured model can be used to investigate the effect of age-specific targeting for public health purposes.