Low dispersing species : population genetic processes in space and time : the genus "Trochulus" (Gastropoda: Hygromiidae) as a case study

RÉSUMÉ Une espèce est rarement composée d'une population unique. Parce que les individus ont des capacités de dispersion limitées et que les paysages sont des mosaïques d'habitats, la plupart des espèces sont plutôt composées de sous-populations connectées par la migration. Cette variation spatiale influence directement la distribution de la variabilité génétique dans et entre les populations. Durant ce travail, nous avons abordé certains des processus populationnels qui ont joué un rôle supposé dans l'apparition de nouvelles espèces au sein du genre Trochulus. Plus précisément, nous avons tenté d'évaluer les impacts respectifs de l'isolement passé (facteurs historiques) et présent (facteurs locaux). Nous avons d'abord pu montrer que les faibles capacités de dispersion des escargots terrestres ont directement influencé leur histoire évolutive à toutes les échelles spatiales et temporelles. En réduisant l'effet homogénéisant de la migration, une faible dispersion maintient dans les populations les traces génétiques d'évènements passés. A l'échelle de la distribution globale de Trochulus villosus, ces traces ont permis de reconstruire une histoire faite d'isolements et d'expansions de populations. En combinant des données génétiques avec une modélisation de la niche climatique passée, il a été possible de proposer un scénario significativement meilleur que toutes les hypothèses alternatives que nous avons testées. A l'échelle locale par contre, l'héritage historique est difficile à distinguer de la dynamique actuelle. Ce fut le cas des lignées mitochondriales du complexe sericeus-hispidus : les deux principales lignées étaient phylogénétiquement éloignées, avaient eu des démographies passées différentes et corrélaient avec des différences morphologiques. D'un autre côté, le flux de gène nucléaire était fort, contredisant l'idée de deux espèces cryptiques isolées reproductivement. Pour pouvoir conclure à la présence ou non de deux espèces, il nous a manqué des informations locales sur la dynamique des populations et les conditions écologiques que l'on trouve dans la région d'étude. Enfin, nous avons pu souligner que la connectivité entre populations d'escargots est soumise à la qualité des habitats et à leur organisation spatiale. Les escargots sont dépendants d'un habitat et s'y adaptent, comme l'indiquent la présence de «poils » uniquement sur la coquille d'espèces vivant dans des habitats humides ou la corrélation entre morphologie et habitat au sein du complexe sericeus-hispidus. Logiquement donc, les escargots migrent préférentiellement au travers d'habitats favorables comme l'a montré la réduction de flux de gènes au travers des prairies chez T. villosus (une espèce forestière). De ces données, nous pouvons supposer que les populations d'escargots en particulier, et des espèces à faible dispersion en général, ont de fortes chances d'être affectées par les changements climatiques, avec de probables implications pour leurs histoires évolutives. SUMMARY : Species rarely consists in a single population. Because individuals have limited dispersal abilities, because landscapes are habitat patchworks, most species are made of several subpopulations connected by migration. This spatial variation has consequences on the distribution of genetic diversity within and between populations, creating a structure among the populations. During the present work, we investigated some of the population processes assumed to have played an important role on the speciation within the genus Trochulus. More specifically, we questioned the respective impacts of past (historical factors) or present (local factors) population isolations. We first could show that the poor dispersal abilities of land snails have had profound impacts on their evolutionary histories at all spatial and temporal scales. Low dispersal maintains a strong signature of past events in the populations by minimising the homogenising effects of geneflow. At the scale of Trochulus villosus global distribution, they allowed to retrieve the detailed history of this species population isolations and expansions. Combining a large genetic dataset with paleo-climatic niche modelling ended up with a historical scenario significantly better than all traditional alternatives we tested. At local scale on the contrary, past events become difficult to tease apart from ongoing processes. This was the case for the divergent mitochondria) lineages within the sericeus-hispidus complex: the two principal lineages appeared to be phylogenetically distant, to have experienced different demographic histories and to correlate with morphological differences. On the other hand, nuclear (present day) geneflow was high, contradicting the idea of two reproductively isolated cryptic species. Information on the local population dynamics and environmental conditions are lacking to be able to decide whether past isolation has indeed resulted here in new species. Finally, we emphasised the importance of the habitat types present in a landscape as well as their spatial organisation for the population connectivity of land snails. These species are tightly dependent on a habitat and adapt to it as shown by thé occurrence of hair-like structures only in species living in humid environments or by the correlation between shell morphology and habitat in the sericeus-hispidus complex. As a result, land snails preferentially migrate through favourable habitats: Trochulus villosus, a forest species, had its geneflow significantly reduced across meadows. From these data, we can hypothesise that the populations of land snails in particular and of low dispersing species in general are likely to be strongly affected by the ongoing climate changes, with potential major consequences on their evolutionary histories.

Volume of Traffic on the Primary Road System, 2002

The Office of Transportation Data, in cooperation with the Federal Highway Administration, prepares this biennial traffic report. This report is used by federal, state, and local governmental agencies in determining highway needs, construction priorities, route location and environmental impact studies, and the application of appropriate design standards. The general public uses this information in determining the amount of traffic that passes a given area as they make their development plans and propose land use changes. The above reflects only a few of the many technical uses for this data.

The effects of tourism, beachfront development and increased light pollution on nesting Loggerhead turtles Caretta caretta (Linnaeus, 1758) on Sal, Cape Verde Islands

Loggerhead Caretta caretta is now the only species of marine turtle nesting on the island of Sal, Cape Verde Islands. Since 2008, ADTMA - SOS Tartarugas has patrolled all the southern beaches of the island in order to protect nesting females and to collect nesting data. Although hunting is still a major issue, with 90 turtles killed in 2009, habitat loss and light pollution are becoming an ever more serious threat. Construction sites, hotels, apartment buildings and restaurants close to beaches, bright lights and illegal removal of sand are contributing to a marked decrease in the total number of nesting turtles on some beaches. In 2009, beaches on Sal experienced an average increase in nests of 200%, while the beach most affected by construction (Tortuga Beach) saw a decrease of nests of 7.3% (from 19.1% of total number of nests in 2008 to 11.8% in 2010). This beach also recorded a much lower nest to emergence ratio than normal (17.6% of emergences resulting in nests compared to 29.9% in other areas), indicating reluctance to nest due to light pollution and other disturbances.

Multiscale phylogeography: glacial history and autopolyploidy of Biscutella laevigata L. (Brassicaceae) in the Western Alps

Résumé Les changements climatiques du Quaternaire ont eu une influence majeure sur la distribution et l'évolution des biota septentrionaux. Les Alpes offrent un cadre spatio-temporel bien étudié pour comprendre la réactivité de la flore et le potentiel d'adaptation d'une espèce végétale face aux changements climatiques. Certaines hypothèses postulent une diversification des espèces en raison de la disparition complète de la flore des Alpes et d'un isolement important des espèces dans des refuges méridionaux durant les dernières glaciations (Tabula Rasa). Une autre hypothèse stipule le maintien de poches de résistance pour la végétation au coeur des Alpes (Nunataks). Comme de nombreuses espèces végétales présentant un grand succès écologique semblent avoir réagi aux glaciations par la multiplication de leur génome (autopolyploïdie), leur étude en milieu naturel devrait permettre de comprendre les avantages inhérents à la polyploïdie. Biscutella laevigata est un modèle emblématique de biogéographie historique, diverses études ayant montré que des populations diploïdes sont actuellement isolées dans les zones restées déglacées durant le dernier maximum glaciaire, alors que des tétraploïdes ont recolonisé l'ensemble des zones alpines mises à nu par le retrait des glaciers. Si le contexte périglaciaire semble avoir favorisé ce jeune complexe autopolyploïde, les circonstances et les avantages de cette mutation génomique ne sont pas encore clairs. Y a-t-il eu de multiples événements de polyploïdisation ? Dans quelle mesure affecte(nt)il(s) la diversité génétique et le potentiel évolutif des polyploïdes ? Les polyploïdes ont-ils une grande flexibilité génomique, favorisant une radiation adaptative, ou doivent-ils leur succès à une grande plasticité écologique ? Cette étude aborde ces questions à différentes échelles spatiales et temporelles. L'échelle régionale des Alpes occidentales permet d'aborder les facteurs distaux (aspects historiques), alors que l'échelle locale cherche à appréhender les facteurs proximaux (mécanismes évolutifs). Dans les Alpes occidentales, des populations ont été densément échantillonnées et étudiées grâce à (1) leur cytotype, (2) leur appartenance taxonomique, (3) leur habitat et (4) des marqueurs moléculaires de l'ADN chloroplastique, en vue d'établir leurs affinités évolutives. Á l'échelle locale, deux systèmes de population ont été étudiés : l'un où les populations persistent en périphérie de l'aire de distribution et l'autre au niveau du front actif de colonisation, en marge altitudinale. Les résultats à l'échelle des Alpes occidentales révèlent les sites d'intérêt (refuges glaciaires, principales barrières et voies de recolonisation) pour une espèce représentative des pelouses alpines, ainsi que pour la biodiversité régionale. Les Préalpes ont joué un rôle important dans le maintien de populations à proximité immédiate des Alpes centrales et dans l'évolution du taxon, voire de la végétation. Il est aussi démontré que l'époque glaciaire a favorisé l'autopolyploïdie polytopique et la recolonisation des Alpes occidentales par des lignées distinctes qui s'hybrident au centre des Alpes, influençant fortement leur diversité génétique et leur potentiel évolutif. L'analyse de populations locales en situations contrastées à l'aide de marqueurs AFLP montre qu'au sein d'une lignée présentant une grande expansion, la diversité génétique est façonnée par des forces évolutives différentes selon le contexte écologique et historique. Les populations persistant présentent une dispersion des gènes restreinte, engendrant une diversité génétique assez faible, mais semblent adaptées aux conditions locales de l'environnement. À l'inverse, les populations colonisant la marge altitudinale sont influencées par les effets de fondation conjugués à une importante dispersion des gènes et, si ces processus impliquent une grande diversité génétique, ils engendrent une répartition aléatoire des génotypes dans l'environnement. Les autopolyploïdes apparaissent ainsi comme capables de persister face aux changements climatiques grâce à certaines facultés d'adaptation locale et de grandes capacités à maintenir une importante diversité génétique lors de la recolonisation post-glaciaire. Summary The extreme climate changes of the Quaternary have had a major influence on species distribution and evolution. The European Alps offer a great framework to investigate flora reactivity and the adaptive potential of species under changing climate. Some hypotheses postulate diversification due to vegetation removal and important isolation in southern refugia (Tabula Rasa), while others explain phylogeographic patterns by the survival of species in favourable Nunataks within the Alps. Since numerous species have successfully reacted to past climate changes by genome multiplication (autopolyploidy), studies of such taxa in natural conditions is likely to explain the ecological success and the advantages of autopolyploidy. Early cytogeographical surveys of Biscutella laevigata have shed light on the links between autopolyploidy and glaciations by indicating that diploids are now spatially isolated in never-glaciated areas, while autotetraploids have recolonised the zones covered by glaciers- during the last glacial maximum. A periglacial context apparently favoured this young autopolyploid complex but the circumstances and the advantages of this genomic mutation remain unclear. What is the glacial history of the B. laevigata autopolyploid complex? Are there multiple events of polyploidisation? To what extent do they affect the genetic diversity and the evolutionary potential of polyploids? Is recolonisation associated with adaptive processes? How does long-term persistence affect genetic diversity? The present study addresses these questions at different spatiotemporal scales. A regional survey at the Western Alps-scale tackles distal factors (evolutionary history), while local-scale studies explore proximal factors (evolutionary mechanisms). In the Western Alps, populations have been densely sampled and studied from the (1) cytotypic, (2) morphotaxonomic, (3) habitat point of views, as well as (4) plastid DNA molecular markers, in order to infer their relationships and establish the maternal lineages phylogeography. At the local scale, populations persisting at the rear edge and populations recolonising the attitudinal margin at the leading edge have been studied by AFLPs to show how genetic diversity is shaped by different evolutionary forces across the species range. The results at the regional scale document the glacial history of a widespread species, representative of alpine meadows, in a regional area of main interest (glacial refugia, main barriers and recolonisation routes) and points out to sites of interest for regional biodiversity. The external Alps have played a major role in the maintenance of populations near the central Alps during the Last Glacial Maximum and influenced the evolution of the species, and of vegetation. Polytopic autopolyploidy in different biogeographic districts is also demonstrated. The species has had an important and rapid radiation because recolonisation took place from different refugia. The subsequent recolonisation of the Western Alps was achieved by independent lineages that are presently admixing in the central Alps. The role of the Pennic summit line is underlined as a great barrier that was permeable only through certain favourable high-altitude passes. The central Alps are thus viewed as an important crossroad where genomes with different evolutionary histories are meeting and admixing. The AFLP analysis and comparison of local populations growing in contrasted ecological and historical situations indicate that populations persisting in the external Alps present restricted gene dispersal and low genetic diversity but seem in equilibrium with their environment. On the contrary, populations colonising the attitudinal margin are mainly influenced by founder effects together with great gene dispersal and genotypes have a nearly random distribution, suggesting that recolonisation is not associated with adaptive processes. Autopolyploids that locally persist against climate changes thus seem to present adaptive ability, while those that actively recolonise the Alps are successful because of their great capacity to maintain a high genetic diversity against founder effects during recolonisation.

Phylogeographical structure, postglacial recolonization and barriers to gene flow in the distinctive Valais chromosome race of the common shrew (Sorex araneus).

Using one male-inherited and eight biparentally inherited microsatellite markers, we investigate the population genetic structure of the Valais chromosome race of the common shrew (Sorex araneus) in the Central Alps of Europe. Unexpectedly, the Y-chromosome microsatellite suggests nearly complete absence of male gene flow among populations from the St-Bernard and Simplon regions (Switzerland). Autosomal markers also show significant genetic structuring among these two geographical areas. Isolation by distance is significant and possible barriers to gene flow exist in the study area. Two different approaches are used to better understand the geographical patterns and the causes of this structuring. Using a principal component analysis for which testing procedure exists, and partial Mantel tests, we show that the St-Bernard pass does not represent a significant barrier to gene flow although it culminates at 2469 m, close to the highest altitudinal record for this species. Similar results are found for the Simplon pass, indicating that both passes represented potential postglacial recolonization routes into Switzerland from Italian refugia after the last Pleistocene glaciations. In contrast with the weak effect of these mountain passes, the Rhône valley lowlands significantly reduce gene flow in this species. Natural obstacles (the large Rhône river) and unsuitable habitats (dry slopes) are both present in the valley. Moreover, anthropogenic changes to landscape structures are likely to have strongly reduced available habitats for this shrew in the lowlands, thereby promoting genetic differentiation of populations found on opposite sides of the Rhône valley.

Density and distribution of nests of Mycetophylax simplex (Emery) (Hymenoptera, Formicidae) in areas with mobile dunes on the northern coast of Rio Grande do Sul, Brazil

Studies on lower attines are scarce, especially on nesting and foraging ecology and behavior. This study aimed to contribute to the knowledge of an Attini in dunes ecosystems through the description of density and spatial distribution of Mycetophylax simplex (Emery, 1887) nests in a strip of mobile dunes in the Praia Grande beach, Torres, northern coast of Rio Grande do Sul, Brazil. The density and spatial distribution of nests were estimated in four plots of 2,500 m² each, in which were found 20, 209, 284 and 324 nests, with average densities of 0.01 nests/m², 0.09, 0.11 and 0.13 nests/m², respectively. The nests were found near to the vegetation and showed clumped distribution. The density and distribution pattern of the nests seem to be related to the availability of nesting places and foraging resources.

Relatório de Estágio Profissional: Departamento F&B

O presente relatório enquadra-se no plano curricular, pertencente ao curso de Gestão Hoteleira e Turismo, frequentado na Universidade de Mindelo. O estágio profissional decorreu no hotel Tortuga Beach, integrante da cadeia de Hotéis Meliã. Neste relatório poder-se-ão, encontrar descritos, os locais do departamento onde foi desenvolvido o estágio, bem como as actividades desenvolvidas ao longo dos três meses da sua duração. No final, encontra-se a reflexão crítica dividida por aprendizagens, dificuldades e sugestões, que faz a avaliação geral do estágio. Em jeito de considerações finais, encontram-se as conclusões, realçam-se as ideias gerais do estágio e reforça-se a opinião sobre o decorrer do mesmo.

Extracção de areia na Praia de Calhetona (Ilha de Santiago, Cabo Verde) : causas, processos e consequências

A extracção de areia nas praias do mar, nas bacias hidrográficas e nas encostas montanhosas, tem sido prática de muitas famílias cabo-verdianas. A Praia de Calhetona foi uma das que nos últimos anos sofreu degradação significativa, em função da apanha clandestina de areia, sem qualquer plano de extracção, destinada a construção civil. A extracção de areia, para vender ou para a autoconstrução, é efectuada em família por indivíduos, maioritariamente do sexo feminino, de baixa renda ou sem profissão remunerada. O processo de extracção de areia na Praia de Calhetona teve o seu ponto alto nos anos 80, diminuindo consideravelmente com a escassez de areia e implementação do Decreto – Lei nº 69/97, de 3 de Novembro, que visava disciplinar a exploração de inertes nas praias. Em face da pesquisa feita, baseada no estudo de caso, ficou expresso que os inquiridos implicados na actividade de extracção clandestina de areia correm riscos elevados para obterem lucros reduzidos. Quem efectivamente beneficia são os camionistas que compram esse inerte e o vendem pelo dobro do preço. Qualquer actividade de exploração de recursos naturais causa impactes sobre o espaço de actuação. No caso da Praia de Calhetona, observa-se o recuo da linha de costa, a quase ausência de areia e a desertificação de propriedades nas suas proximidades, para além dos impactes negativos sobre o turismo, a função balnear e a desova de tartaruga. Apesar de tudo, constata-se uma consciência generalizada dos impactes ambientais causados pelos inquiridos, os quais, no entanto, alegam que a extracção de areia é uma das alternativas para garantir a sobrevivência individual e das suas famílias.

Extracção de areia na Praia de Calhetona (Ilha de Santiago, Cabo Verde) : causas, processos e consequências

A extracção de areia nas praias do mar, nas bacias hidrográficas e nas encostas montanhosas, tem sido prática de muitas famílias cabo-verdianas. A Praia de Calhetona foi uma das que nos últimos anos sofreu degradação significativa, em função da apanha clandestina de areia, sem qualquer plano de extracção, destinada a construção civil. A extracção de areia, para vender ou para a autoconstrução, é efectuada em família por indivíduos, maioritariamente do sexo feminino, de baixa renda ou sem profissão remunerada. O processo de extracção de areia na Praia de Calhetona teve o seu ponto alto nos anos 80, diminuindo consideravelmente com a escassez de areia e implementação do Decreto – Lei nº 69/97, de 3 de Novembro, que visava disciplinar a exploração de inertes nas praias. Em face da pesquisa feita, baseada no estudo de caso, ficou expresso que os inquiridos implicados na actividade de extracção clandestina de areia correm riscos elevados para obterem lucros reduzidos. Quem efectivamente beneficia são os camionistas que compram esse inerte e o vendem pelo dobro do preço. Qualquer actividade de exploração de recursos naturais causa impactes sobre o espaço de actuação. No caso da Praia de Calhetona, observa-se o recuo da linha de costa, a quase ausência de areia e a desertificação de propriedades nas suas proximidades, para além dos impactes negativos sobre o turismo, a função balnear e a desova de tartaruga. Apesar de tudo, constata-se uma consciência generalizada dos impactes ambientais causados pelos inquiridos, os quais, no entanto, alegam que a extracção de areia é uma das alternativas para garantir a sobrevivência individual e das suas famílias.

Extracção de areia na Praia de Calhetona (Ilha de Santiago, Cabo Verde) : causas, processos e consequências

A extracção de areia nas praias do mar, nas bacias hidrográficas e nas encostas montanhosas, tem sido prática de muitas famílias cabo-verdianas. A Praia de Calhetona foi uma das que nos últimos anos sofreu degradação significativa, em função da apanha clandestina de areia, sem qualquer plano de extracção, destinada a construção civil. A extracção de areia, para vender ou para a autoconstrução, é efectuada em família por indivíduos, maioritariamente do sexo feminino, de baixa renda ou sem profissão remunerada. O processo de extracção de areia na Praia de Calhetona teve o seu ponto alto nos anos 80, diminuindo consideravelmente com a escassez de areia e implementação do Decreto – Lei nº 69/97, de 3 de Novembro, que visava disciplinar a exploração de inertes nas praias. Em face da pesquisa feita, baseada no estudo de caso, ficou expresso que os inquiridos implicados na actividade de extracção clandestina de areia correm riscos elevados para obterem lucros reduzidos. Quem efectivamente beneficia são os camionistas que compram esse inerte e o vendem pelo dobro do preço. Qualquer actividade de exploração de recursos naturais causa impactes sobre o espaço de actuação. No caso da Praia de Calhetona, observa-se o recuo da linha de costa, a quase ausência de areia e a desertificação de propriedades nas suas proximidades, para além dos impactes negativos sobre o turismo, a função balnear e a desova de tartaruga. Apesar de tudo, constata-se uma consciência generalizada dos impactes ambientais causados pelos inquiridos, os quais, no entanto, alegam que a extracção de areia é uma das alternativas para garantir a sobrevivência individual e das suas famílias.

Principal curves and principal oriented points

Principal curves have been defined Hastie and Stuetzle (JASA, 1989) assmooth curves passing through the middle of a multidimensional dataset. They are nonlinear generalizations of the first principalcomponent, a characterization of which is the basis for the principalcurves definition.In this paper we propose an alternative approach based on a differentproperty of principal components. Consider a point in the space wherea multivariate normal is defined and, for each hyperplane containingthat point, compute the total variance of the normal distributionconditioned to belong to that hyperplane. Choose now the hyperplaneminimizing this conditional total variance and look for thecorresponding conditional mean. The first principal component of theoriginal distribution passes by this conditional mean and it isorthogonal to that hyperplane. This property is easily generalized todata sets with nonlinear structure. Repeating the search from differentstarting points, many points analogous to conditional means are found.We call them principal oriented points. When a one-dimensional curveruns the set of these special points it is called principal curve oforiented points. Successive principal curves are recursively definedfrom a generalization of the total variance.

Concepções, Práxis e Tendências de Desenvolvimento Curricular no Ensino Superior Público em Cabo Verde: um Estudo de Caso Sobre a Universidade de Cabo Verde

A tese enquadra-se nas discussões sobre as concepções do currículo, como problemática central nos processos de educação e formação, e o papel da Universidade ao longo dos tempos, mormente nos contextos actuais da globalização, conferindo especial relevo às concepções, práxis e tendências que caracterizam a experiência de desenvolvimento curricular na Universidade de Cabo Verde (Uni-CV), desde a sua criação, em Novembro de 2006, no seguimento de um percurso de quase três décadas do ensino superior público cabo-verdiano Com o enquadramento teórico da problemática da investigação faz-se uma ampla cartografia da literatura relevante no campo científico dos estudos curriculares, numa abordagem que patenteia a diversidade de conceptualizações do currículo e do desenvolvimento curricular, os principais traços característicos das teorias curriculares que se têm sucedido e ou que rivalizam na busca de hegemonia no sector da educação, bem como as políticas educativas e curriculares que vêm sendo concebidas e realizadas à escala global, dispensando atenção particular às dimensões instituinte e instituída do processo curricular. Ainda que fortemente condicionado pelas concepções e políticas de globalização da educação, a tendência para a uniformização educativa e curricular não constitui uma inevitabilidade, demonstrando-se, pelo contrário, que o processo de desenvolvimento curricular deixa espaços de apropriação e inovação ao nível das instituições educativas, atendendo à diversidade de contextos, expectativas e perspectivas inerentes à dinâmica da realização do currículo. Ainda no plano teórico, ao analisar-se a evolução do conceito ou ideia de Universidade, desde a sua génese até aos tempos actuais, coloca-se em relevo a natureza específica da instituição no âmbito do ensino superior, patenteando o modo como, nos diferentes contextos, a mesma tem procurado afirmar a centralidade do conhecimento e do currículo no cumprimento da sua missão, a despeito de factores e condicionalismos diversos, de entre os quais releva o tipo de relacionamento predominante entre a Universidade, o Estado e o mercado, no âmbito do qual se deve entender a complexidade da crise institucional, na triplicidade das suas manifestações (crise de legitimidade, de hegemonia e de identidade) que atravessa a academia, com reflexos ao nível das tendências para o condicionamento da autonomia, missão e funções da academia, assim como da própria natureza do conhecimento universitário. Na procura de saídas para a crise, que é global e, como tal, se reflecte nas universidades do continente africano, em que se insere Cabo Verde, a Universidade é desafiada a afirmar a sua especificidade institucional, enquanto promotora da alta cultura e da capacidade de pensamento de longo prazo, conciliando, deste modo, as suas funções essenciais ou simbólicas com as que se prendem com a satisfação das necessidades imediatas ou de curto prazo da economia e do mercado. Com base nos pertinentes subsídios teóricos, os estudos empíricos desenvolvem-se segundo a abordagem metodológica de estudo de caso, em que a análise documental e as técnicas de investigação qualitativa e quantitativa permitiram consolidar as evidências sobre: (i) os antecedentes da criação da Uni-CV, através do mapeamento do percurso académico e curricular dos diversos estabelecimentos públicos de ensino superior que precederam a universidade pública, legando a esta o seu património científico, tecnológico e logístico, com as inerentes potencialidades e limitações; (ii) o processo de institucionalização da Uni-CV, com a referencialização das opções estruturantes da organização e gestão da Universidade assim como da política educativa e curricular da Universidade; (iii) a experiência multifacetada de desenvolvimento curricular na novel instituição durante os cinco primeiros anos de funcionamento (2006-2011), correlacionando opções e práxis e evidenciando tendências da sua evolução. Da análise interpretativa dos estudos empíricos realizados, mediante a triangulação dos dados de arquivo e de perspectiva, resulta que a Uni-CV, não obstante as fragilidades persistentes no processo de seu desenvolvimento institucional, tem cumprido a sua missão de forma satisfatória, facto que fica a dever-se quer à adequação das opções, normas e directivas conformadoras da dimensão instituinte do processo curricular, quer ao esforço de realização das prescrições curriculares, sendo, todavia, evidentes os desafios a serem vencidos tendo em vista a consecução da almejada excelência académica, que os Estatutos propugnam, e que passa, nomeadamente, pela melhoria do nível da qualificação do seu corpo docente, pela implementação ou funcionamento efectivo de alguns dos órgãos da academia e pela afirmação da investigação científica como função incontornável para o desempenho cabal das funções de ensino e extensão. De entre as conclusões, sustenta-se que, no processo de integração de Cabo Verde nas redes internacionais de investigação e excelência científica e tecnológica, como, de resto, propugnam os Estatutos da Uni-CV, deve atender-se à especificidade deste pequeno país do Atlântico Médio, tendo em conta as suas fragilidades estruturais, pelo que se impõe algum distanciamento crítico em relação à incorporação de certas opções de política educativa e curricular que emanam de instâncias internacionais, independentemente do seu carácter inovador ou mesmo da sua possível consistência científica e técnica, comprovada em outros contextos.

Extracção de Areia na Praia de Calhetona (Ilha de Santiago, Cabo Verde) - Causas, Processos e Consequências

A extracção de areia nas praias do mar, nas bacias hidrográficas e nas encostas montanhosas, tem sido prática de muitas famílias cabo-verdianas. A Praia de Calhetona foi uma das que nos últimos anos sofreu degradação significativa, em função da apanha clandestina de areia, sem qualquer plano de extracção, destinada a construção civil. A extracção de areia, para vender ou para a autoconstrução, é efectuada em família por indivíduos, maioritariamente do sexo feminino, de baixa renda ou sem profissão remunerada. O processo de extracção de areia na Praia de Calhetona teve o seu ponto alto nos anos 80, diminuindo consideravelmente com a escassez de areia e implementação do Decreto – Lei nº 69/97, de 3 de Novembro, que visava disciplinar a exploração de inertes nas praias. Em face da pesquisa feita, baseada no estudo de caso, ficou expresso que os inquiridos implicados na actividade de extracção clandestina de areia correm riscos elevados para obterem lucros reduzidos. Quem efectivamente beneficia são os camionistas que compram esse inerte e o vendem pelo dobro do preço. Qualquer actividade de exploração de recursos naturais causa impactes sobre o espaço de actuação. No caso da Praia de Calhetona, observa-se o recuo da linha de costa, a quase ausência de areia e a desertificação de propriedades nas suas proximidades, para além dos impactes negativos sobre o turismo, a função balnear e a desova de tartaruga. Apesar de tudo, constata-se uma consciência generalizada dos impactes ambientais causados pelos inquiridos, os quais, no entanto, alegam que a extracção de areia é uma das alternativas para garantir a sobrevivência individual e das suas famílias.

Phylogenetic analyses of C4 photosynthesis evolution in grasses: genetics of convergence and convergence of genes

Summary : During the evolutionary diversification of organisms, similar ecological constraints led to the recurrent appearances of the same traits (phenotypes) in distant lineages, a phenomenon called convergence. In most cases, the genetic origins of the convergent traits remain unknown, but recent studies traced the convergent phenotypes to recurrent alterations of the same gene or, in a few cases, to identical genetic changes. However, these cases remain anecdotal and there is a need for a study system that evolved several times independently and whose genetic determinism is well resolved and straightforward, such as C4 photosynthesis. This adaptation to warm environments, possibly driven by past atmospheric CO2 decreases, consists in a CO2-concentrating pump, created by numerous morphological and biochemical novelties. All genes encoding C4 enzymes already existed in C3 ancestors, and are supposed to have been recruited through gene duplication followed by neo-functionalization, to acquire the cell specific expression pattern and altered kinetic properties that characterize Ca-specific enzymes. These predictions have so far been tested only in species-poor and ecologically marginal C4 dicots. The monocots, and especially the grass family (Poaceae), the most important C4 family in terms of species number, ecological dominance and economical importance, have been largely under-considered as suitable study systems. This thesis aimed at understanding the evolution of the C4 trait in grasses at a molecular level and to use the genetics of C4 photosynthesis to infer the evolutionary history of the C4 phenotype and its driving selective pressures. A molecular phylogeny of grasses and affiliated monocots identified 17 to 18 independent acquisitions of the C4 pathway in the grass family. A relaxed molecular clock was used to date these events and the first C4 evolution was estimated in the Chloridoideae subfamily, between 32-25 million years ago, at a period when atmospheric CO2 abruptly declined. Likelihood models showed that after the COZ decline the probability of evolving the C4 pathway strongly increased, confirming low CO2 as a likely driver of C4 photosynthesis evolution. In order to depict the genetic changes linked to the numerous C4 origins, genes encoding phopshoenolpyruvate carboxylase (PEPC), the key-enzyme responsible for the initial fixation of atmospheric CO2 in the C4 pathway, were isolated from a large sample of C3 and C4 grasses. Phylogenetic analyses were used to reconstruct the evolutionary history of the PEPC multigene family and showed that the evolution of C4-specific PEPC had been driven by positive selection on 21 codons simultaneously in up to eight C4 lineages. These selective pressures led to numerous convergent genetic changes in many different C4 clades, highlighting the repeatability of some evolutionary processes, even at the molecular level. PEPC C4-adaptive changes were traced and used to show multiple appearances of the C, pathway in clades where species tree inferences were unable to differentiate multiple C4 appearances and a single appearance followed by C4 to C3 reversion. Further investigations of genes involved in some of the C4 subtypes only (genes encoding decarboxylating enzymes NADP-malic enzyme and phosphoenolpyruvate carboxykinase) showed that these C4-enzymes also evolved through strong positive selection and underwent parallel genetic changes during the different Ca origins. The adaptive changes on these subtype-specific C4 genes were used to retrace the history of the C4-subtypes phenotypes, which revealed that the evolution of C4-PEPC and C4-decarboxylating enzymes was in several cases disconnected, emphasizing the multiplicity of the C4 trait and the gradual acquisition of the features that create the CO2-pump. Finally, phylogenetic analyses of a gene encoding the Rubisco (the enzyme responsible for the fixation of CO2 into organic compounds in all photosynthetic organisms) showed that C4 evolution switched the selective pressures on this gene. Five codons were recurrently mutated to adapt the enzyme kinetics to the high CO2 concentrations of C4 photosynthetic cells. This knowledge could be used to introgress C4-like Rubisco in C3 crops, which could lead to an increased yield under predicted future high CO2 atmosphere. Globally, the phylogenetic framework adopted during this thesis demonstrated the widespread occurrence of genetic convergence on C4-related enzymes. The genetic traces of C4 photosynthesis evolution allowed reconstructing events that happened during the last 30 million years and proved the usefulness of studying genes directly responsible for phenotype variations when inferring evolutionary history of a given trait. Résumé Durant la diversification évolutive des organismes, des pressions écologiques similaires ont amené à l'apparition récurrente de certains traits (phénotypes) dans des lignées distantes, un phénomène appelé évolution convergente. Dans la plupart des cas, l'origine génétique des traits convergents reste inconnue mais des études récentes ont montré qu'ils étaient dus dans certains cas à des changements répétés du même gène ou, dans de rares cas, à des changements génétiques identiques. Malgré tout, ces cas restent anecdotiques et il y a un réel besoin d'un système d'étude qui ait évolué indépendamment de nombreuses fois et dont le déterminisme génétique soit clairement identifié. La photosynthèse dite en Ça répond à ces critères. Cette adaptation aux environnements chauds, dont l'évolution a pu être encouragé par des baisses passées de la concentration atmosphérique en CO2, est constituée de nombreuses nouveautés morphologiques et biochimiques qui créent une pompe à CO2. La totalité des gènes codant les enzymes Ç4 étaient déjà présents dans les ancêtres C3. Leur recrutement pour la photosynthèse Ç4 est supposé s'être fait par le biais de duplications géniques suivies par une néo-fonctionnalisation pour leur conférer l'expression cellule-spécifique et les propriétés cinétiques qui caractérisent les enzymes C4. Ces prédictions n'ont jusqu'à présent été testées que dans des familles C4 contenant peu d'espèces et ayant un rôle écologique marginal. Les graminées (Poaceae), qui sont la famille C4 la plus importante, tant en termes de nombre d'espèces que de dominance écologique et d'importance économique, ont toujours été considérés comme un système d'étude peu adapté et ont fait le sujet de peu d'investigations évolutives. Le but de cette thèse était de comprendre l'évolution de la photosynthèse en C4 chez les graminées au niveau génétique et d'utiliser les gènes pour inférer l'évolution du phénotype C4 ainsi que les pressions de sélection responsables de son évolution. Une phylogénie moléculaire de la famille des graminées et des monocotylédones apparentés a identifié 17 à 18 acquisitions indépendantes de la photosynthèse chez les graminées. Grâce à une méthode d'horloge moléculaire relâchée, ces évènements ont été datés et la première apparition C4 a été estimée dans la sous-famille des Chloridoideae, il y a 32 à 25 millions d'années, à une période où les concentrations atmosphériques de CO2 ont décliné abruptement. Des modèles de maximum de vraisemblance ont montré qu'à la suite du déclin de CO2, la probabilité d'évoluer la photosynthèse C4 a fortement augmenté, confirmant ainsi qu'une faible concentration de CO2 est une cause potentielle de l'évolution de la photosynthèse C4. Afin d'identifier les mécanismes génétiques responsables des évolutions répétées de la photosynthèse C4, un segment des gènes codant pour la phosphoénolpyruvate carboxylase (PEPC), l'enzyme responsable de la fixation initiale du CO2 atmosphérique chez les plantes C4, ont été séquencés dans une centaine de graminées C3 et C4. Des analyses phylogénétiques ont permis de reconstituer l'histoire évolutive de la famille multigénique des PEPC et ont montré que l'évolution de PEPC spécifiques à la photosynthèse Ça a été causée par de la sélection positive agissant sur 21 codons, et ce simultanément dans huit lignées C4 différentes. Cette sélection positive a conduit à un grand nombre de changements génétiques convergents dans de nombreux clades différents, ce qui illustre la répétabilité de certains phénomènes évolutifs, et ce même au niveau génétique. Les changements sur la PEPC liés au C4 ont été utilisés pour confirmer des évolutions indépendantes du phénotype C4 dans des clades où l'arbre des espèces était incapable de différencier des apparitions indépendantes d'une seule apparition suivie par une réversion de C4 en C3. En considérant des gènes codant des protéines impliquées uniquement dans certains sous-types C4 (deux décarboxylases, l'enzyme malique à NADP et la phosphoénolpyruvate carboxykinase), des études ultérieures ont montré que ces enzymes C4 avaient elles-aussi évolué sous forte sélection positive et subi des changements génétiques parallèles lors des différentes origines de la photosynthèse C4. Les changements adaptatifs sur ces gènes liés seulement à certains sous-types C4 ont été utilisés pour retracer l'histoire des phénotypes de sous-types C4, ce qui a révélé que les caractères formant le trait C4 ont, dans certains cas, évolué de manière déconnectée. Ceci souligne la multiplicité du trait C4 et l'acquisition graduelle de composants participant à la pompe à CO2 qu'est la photosynthèse C4. Finalement, des analyses phylogénétiques des gènes codant pour la Rubisco (l'enzyme responsable de la fixation du CO2 en carbones organiques dans tous les organismes photosynthétiques) ont montré que l'évolution de la photosynthèse Ça a changé les pressions de sélection sur ce gène. Cinq codons ont été mutés de façon répétée afin d'adapter les propriétés cinétiques de la Rubisco aux fortes concentrations de CO2 présentes dans les cellules photosynthétiques des plantes C4. Globalement, l'approche phylogénétique adoptée durant cette thèse de doctorat a permis de démontré des phénomène fréquents de convergence génétique sur les enzymes liées à la photosynthèse C4. Les traces génétiques de l'évolution de la photosynthèse C4 ont permis de reconstituer des évènements qui se sont produits durant les derniers 30 millions d'années et ont prouvé l'utilité d'étudier des gènes directement responsables des variations phénotypiques pour inférer l'histoire évolutive d'un trait donné.

Note sur les musaraignes (Soricidae, Mammalia) du Parc National du Souss-Massa Maroc

With 420 trap-nights we sampled shrews in different habitats of the Souss-Massa National Park. Crocidura viaria (n=11) was found in 5 habitats (cultivated land, wetland, beach dunes with Chenopodia, sand dunes with patchy vegetation and also in the Euphorbia association). No shrews were captured in Eucalyptus forest with undergrowth. Southward from Essaouira, C. viaria is obviously the most frequent species in dense or patchy lowland vegetation. Two other species (C. whitakeri and C. tarfayaensis) which occur in sympatry in the Agadir region were not captured. They live probably not in syntopy with C. viaria and their ecological requirements remain to be studied.