We investigate the evolution of dust content in galaxies from redshifts z = 0 to z = 9.5. Using empirically motivated prescriptions, we model galactic-scale properties-including halo mass, stellar mass, star formation rate, gas mass, and metallicity-to make predictions for the galactic evolution of dust mass and dust temperature in main-sequence galaxies. Our simple analytic model, which predicts that galaxies in the early universe had greater quantities of dust than their low-redshift counterparts, does a good job of reproducing observed trends between galaxy dust and stellar mass out to z approximate to 6. We find that for fixed galaxy stellar mass, the dust temperature increases from z = 0 to z = 6. Our model forecasts a population of low-mass, high-redshift galaxies with interstellar dust as hot as, or hotter than, their more massive counterparts; but this prediction needs to be constrained by observations. Finally, we make predictions for observing 1.1 mm flux density arising from interstellar dust emission with the Atacama Large Millimeter Array.

A extinção é uma forma de aprendizado inibitório que se origina na omissão do reforço ou estímulo incondicionado, inibindo a evocação de uma resposta ou comportamento aprendido anteriormente. Muitas formas de aprendizado são moduladas por receptores β- noradrenérgicos, D1-dopaminérgicos e H2-histaminérgicos no córtex pré-frontal ventromedial (vmPFC), no complexo basolateral da amígdala (BLA) e no hipocampo dorsal (DH). Assim, o objetivo do presente trabalho foi investigar a modulação da extinção de memória aversiva nestas três regiões cerebrais. Para isso, utilizamos ratos machos Wistar, que foram submetidos ao paradigma de esquiva inibitória (EI) ou condicionamento contextual ao medo (CCM). As diferentes drogas utilizadas foram infundidas através das cânulas guias implantadas estereotaxicamente no DH, BLA ou vmPFC imediatamente após a sessão de extinção e seus efeitos sobre a extinção foram avaliados em uma sessão de teste realizada 24 h depois. A DSerina (50 μg/lado), modulador positivo do receptor NMDA, e o SKF9188 (12.5 μg/lado), inibidor da enzima histamina metil-transferase, melhoraram a consolidação da memória de extinção nas tarefas de EI e CCM. Entretanto, o AP5 (5 μg/lado), antagonista do receptor glutamatérgico NMDA, e a ranitidina (17.5 μg/lado), antagonista do receptor histaminérgico H2, prejudicaram a extinção em ambos os paradigmas, indicando que os receptores glutamatérgicos do tipo NMDA estão envolvidos na consolidação dos dois paradigmas utilizados, e que os receptores histaminérgicos H2 modulam a extinção nas três estruturas estudadas. A noradrenalina (1 μg/lado), o antagonista β-adrenoreceptor, timolol (1 μg/lado), o agonista dos receptores D1, SKF38393 (12.5 μg/lado) e o antagonista dos receptores D1, SCH23390 (1.5 μg/lado) também afetam a extinção nas duas tarefas, porém, seus efeitos são variados dependendo da tarefa e do local da infusão, sugerindo que a modulação da extinção pelos receptores β- e D1 é mais complexa. Nossos resultados mostram que as três estruturas são ativadas durante o processo de extinção da memória e que os sistemas neuromodulatórios atuam de formas distintas nessas tarefas. / Extinction consists of the learned inhibition of retrieval of previously acquired memory. Many forms of learning are modulated by β-noradrenergic, D1-dopaminergic and H2-histaminergic receptors on ventromedial prefrontal cortex (vmPFC), basolateral amygdala (BLA) and dorsal hippocampus. Therefore, the aim of this work was investigated the modulation of aversive memory extinction in these brain structures. Male Wistar rats were submitted to inhibitory avoidance paradigm (EI) or contextual fear conditioning (CCM). The drugs were infused through cannulae implanted into the DH, BLA or vmPFC immediately after the extinction session and their effects were evaluated 24 h later. D-serine (50 μg/side), a NMDA receptor stimulant, and SKF9188 (12.5 μg/side), a histamine methyl-transferase inhibitor, enhanced the consolidation of the extinction memory in EI and CCM tasks. However, AP5 (5 μg/side), a NMDA-antagonist, and ranitidine (17.5 μg/side), a H2- histaminergic antagonist, impaired the extinction of both tasks, indicated that NMDA receptors are involved in the consolidation of extinction of both tasks, and histamine H2 receptors modulate that process in all areas studied. Noradrenaline (1 μg/side), timolol 1 μg/side), a β-adrenergic antagonist, SKF38393 (12.5 μg/side) and SCH23390 (1.5 μg/side), D1 agonist and antagonist receptor, respectively, also affected the extinction, but their effects varied with the task and with the site of infusion, suggesting that extinction modulation by β- and D1 is more complex. In conclusion, the three structures investigated are activated in the aversive memory extinction and the neuromodulatory systems act of different forms in these structures.

Orientador: Thomas Michael Lewinsohn / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T00:31:43Z (GMT). No. of bitstreams: 1 Loyola_RafaelDias_D.pdf: 14476866 bytes, checksum: c3233f8ed69a9d1f787b6862157bb260 (MD5) Previous issue date: 2008 / Resumo: Procurei identificar prioridades de conservação para vertebrados terrestres em diferentes escalas geográficas (da regional/continental à global), usando ecorregiões como unidades geográficas. Mais especificamente, avaliei (1) a correlação entre riqueza e endemismo exibida por vertebrados terrestres que ocorrem em ecorregiões do Brasil e a eficiência de cada classe de vertebrados terrestres (anfíbios, répteis, aves e mamíferos) como grupos indicadores para a identificação de prioridades de conservação em ecorregiões brasileiras; (2) identifiquei ecorregiões prioritárias para a representação eficiente de todos os vertebrados terrestres, incluindo aqueles endêmicos e ameaçados de extinção, na região Neotropical, e o quanto essas ecorregiões representam da fauna existente nessa província biogeográfica; (3) identifiquei ecorregiões prioritárias para a representação eficiente de todos os anuros (Amphibia: Anura) ameaçados de extinção na região Neotropical e como a inclusão de características da história de vida (e.g. modo reprodutivo) desse grupo no processo de priorização pode auxiliar no delineamento dessas áreas prioritárias; (4) de maneira similar, assinalei ecorregiões prioritárias para a conservação de todos os carnívoros (Mammalia: Carnivora) na região Neotropical e no mundo, e como a inclusão de características ecológicas, evolutivas e da história de vida desse grupo - associadas a custos econômicos (US$/km2) da aquisição de terras em ecorregiões - pode auxiliar no delineamento dessas áreas prioritária. Os resultados apontam, de maneira geral, ecorregiões localizadas no sul do México, América Central, Andes tropicais, sul da América do Sul, sudeste asiático e Filipinas, e a Mata Atlântica brasileira como áreas de extrema relevância, cuja conservação eficiente, por meio de redes de reservas cuidadosamente implementadas, poderia minimizar consideravelmente as ameaças atuais aos vertebrados terrestres. A identificação de áreas prioritárias para a conservação da biodiversidade que vão de uma escala regional/continental à global, é apenas um primeiro passo no estabelecimento de estratégias de conservação in-situ que garantirão a persistência de espécies por períodos ecológicos e evolutivos relevantes para sua existência. Os trabalhos incluídos nessa tese reforçam o arcabouço teórico e metodológico da avaliação de conservação e oferecem bases científicas para o delineamento de regiões prioritárias para a conservação de biodiversidade em um mundo em constante mudança. / Abstract: I aimed to identify conservation priorities for terrestrial vertebrates across different spatial scales (from regional/continental to global), using ecoregions as geographic units. I have evaluated, in particular, (1) the congruence between overall richness and endemism patterns among terrestrial vertebrates that occur in Brazil, and the effectiveness of each vertebrate class (amphibians, reptiles, birds, and mammals) as indicator groups for identifying conservation priorities among Brazilian ecoregions; (2) I have identified priority sets of ecoregions that are effective in representing terrestrial vertebrate diversity in the Neotropics, including those endemics and threatened of extinction; (3) I have also identified priority sets of ecoregions for the conservation of Neotropical threatened anurans, and have also evaluated how the inclusion of species lifehistory traits (e.g. reproductive modes) in the prioritization process may help to improve areasetting analysis; (4) similarly, I have highlighted Neotropical and Global priority sets of ecoregions for the conservation of all carnivores (Mammalia: Carnivora), and again, how the inclusion of biological traits - along with economic costs (US$/km2) of land acquisition within ecoregions - may help in the delineation of these priority set of areas. In general, results highlighted ecoregions found in southern Mexico, Central America, tropical Andes, southern South America, southeast Asia and the Philippines, and the Brazilian Atlantic Forest as extremerelevance areas. Their effective conservation, through the implementation of carefully designed reserve networks, could therefore minimize significantly current threats to terrestrial vertebrates. Identification of a comprehensive set of natural areas, as presented here, is a first step towards an in-situ biodiversity maintenance strategy, which only subtends a much more complex process of policy negotiation and implementation. The studies included in the thesis contribute to a joint framework for the development of national and continental strategies for biodiversity conservation, adding to burgeoning initiatives to plan the application of finite funds and efforts where they will be most effective. / Doutorado / Doutor em Ecologia

O objetivo principal deste trabalho é contribuir para a preservação e/ou manejo da única população conhecida de Aegla strinatii e reforçar ainda mais a necessidade de preservação da área de ocorrência da espécie. Para tanto, foram realizadas coletas mensais ao longo de dois anos de trabalho de campo no Parque Estadual de Jacupiranga, considerado a segunda maior unidade de conservação do Estado com 150.000 hectares, englobando os municípios de Jacupiranga, Barra do Turvo, Cananéia, Iporanga, Eldorado e Cajati (CLAUSET, 1999). Os espécimes foram coletados com peneiras e armadilhas, no rio das Ostras (S 24°38\'16.2\" ; W48°24\'05.2\"),situado no núcleo Caverna do Diabo, no município de Eldorado. Os objetivos da presente contribuição eram: determinar a razão sexual, composição da população, período de recrutamento e crescimento da espécie; quantificar do grau de heteroquelia; verificar o padrão reprodutivo e determinar a fecundidade; verificar uma possível variação do tamanho dos ovos durante o desenvolvimento embrionário; verificar a ocorrência de desovas sucessivas; avaliar, macroscópica e microscopicamente, as gônadas de fêmeas, caracterizando assim os estágios de desenvolvimento gonadal; determinar a primeira maturação de machos e fêmeas; avaliar a distribuição geográfica de Aegla strinatii, visando definir sua área de ocorrência e localização de novas populações; avaliar o status de risco de extinção da espécie com base em critérios sugeridos pelo IUCN (2001). Esta tese de Doutorado está dividida em quatro capítulos, cada qual abrangendo um assunto pertinente à biologia de A. strinatii, a fim de proporcionar uma leitura mais dinâmica e objetiva e facilitar o encaminhamento dos artigos para publicação em revistas científicas. O Capítulo 1 trata da estrutura populacional e biologia reprodutiva de A. strinatii. Para tanto, foram amostrados 867 indivíduos, sendo 401 machos e 466 fêmeas (razão sexual 1:1,16) que apresentaram comprimentos médios da carapaça em machos e fêmeas foram 19,08 e 18,01 mm, respectivamente. O período reprodutivo da espécie pode ser caracterizado como periódico, estendendo-se de maio a setembro. A fecundidade média foi de 186 ovos; os ovos possuíam formato levemente elíptico, com tamanho médio e coloração variando de acordo com o estágio de desenvolvimento embrionário. A análise macroscópica das gônadas permitiu distinguir quatro estágios de maturação. Cortes histológicos mostraram uma sincronia entre esses estágios e o desenvolvimento progressivo das células ovarianas. Espermatozóides bem formados foram observados apenas em machos com comprimento da carapaça superior a 14,49 mm. No segundo capítulo foram analisados a lateralidade, o crescimento relativo do primeiro par de pereópodes e as proporções biométricas entre a largura do abdome, o peso e o comprimento da carapaça em machos e fêmeas de Aegla strinatii. Todas as comparações demonstraram que as quelas de A. strinatii são assimétricas, em termos de comprimento e largura, em machos e fêmeas. Além disso, foi observada uma maior prevalência de maior desenvolvimento da quela esquerda em ambos os sexos. O tipo de crescimento alométrico positivo predominou nas relações biométricas de machos e fêmeas de A. strinatii. Nos machos, todas as relações biométricas apresentaram diferença significativa na comparação entre espécimes jovens e adultos, enquanto os jovens e adultos do sexo feminino diferiram significativamente apenas nas relações entre o comprimento da carapaça e a largura do quelípode maior, largura do abdome e peso. A partir de cada relação biométrica estudada estabeleceu-se um tamanho da maturidade morfométrica para machos e fêmeas. No capítulo 3 são apresentados resultados sobre o crescimento em comprimento de Aegla. Para tanto, distribuiu-se os comprimentos de carapaça (CC) de machos e fêmeas em classes de tamanho separadamente para os animais capturados com peneira e armadilha. As coortes foram reconhecidas através do método de Bhattacharia, utilizando-se o programa de computador FISAT II (versão 1.2.2) e a curva de crescimento foi ajustada segundo o modelo de von Bertalanffy, com o auxílio do programa de computador CAJUS. A idade da primeira maturação dos machos foi baseada no tamanho de maturação obtido através de análises do crescimento relativo (Cap. 2), enquanto que para as fêmeas utilizou-se o tamanho no qual 50% das fêmeas estavam maduras (Cap. 1). A longevidade de A. strinatii foi calculada com base no valor de CC abaixo do qual 95% da população amostrada está representada. Machos e fêmeas apresentaram taxas de crescimento semelhantes (L¥ = 27.51, K = 0.73 para machos; L¥ = 26.96, K = 0.73 para fêmeas). A idade da primeira maturação foi estimada em 16,5 meses para machos e 16,8 para fêmeas e a longevidade estimada em 33,52 e 34,04 meses em machos e fêmeas, respectivamente. As informações obtidas sobre a biologia reprodutiva, dinâmica populacional, distribuição geográfica, habitat ocupado e ainda, inferências sobre as possíveis ameaças à população foram utilizados para calcular o grau de risco de extinção de A. strinatii, que corresponde ao capítulo 4. Neste último capítulo concluiu-se que a espécie pode ser classificada como \"Ameaçada\" uma vez que sua distribuição geográfica é restrita (ocorrência registrada em apenas três localidades), com uma área de ocupação estimada em menos de 500 km², população de adultos estimada em menos de 2.500 indivíduos e declínio contínuo da qualidade do habitat. Este trabalho representa um desdobramento de um projeto mais amplo, que vigorou de 1998 a 2003, denominado \"Levantamento e Biologia de Crustacea, Insecta e Mollusca de água doce do estado de São Paulo\", integrante do Programa BIOTA/FAPESP. Com o término deste projeto, o conhecimento da fauna de crustáceos decápodes do Vale do Ribeira avançou sobremaneira, contudo o estudo de aspectos da biologia, particularmente dos eglídeos da região, ainda era escasso. O presente trabalho visa contribuir para um maior conhecimento da biologia deste maravilhoso e intrigante grupo de crustáceos decápodes. / This study aims to contribute for preservation of the only known population of Aegla strinatii and to reinforce the necessity to preserve the areas where this species occur. Therefore, monthly collections were realized during a two year period at Jacupiranga State Park which is considered to be the second largest conservation unit of São Paulo State. The specimens were sampled with the aid of sieves and traps, in the Ostras stream (S 24°38\'16.2\"; W 48°24\'05.2\"), Eldorado County. The objectives of this study were: to determine the sex ratio, recruitment period and growth in length and weight of the species; to check heterochelous condition; to verify the reproductive period and fecundity; to check the possibility of egg size variation during embryonic development and the occurrence of successive spawning; to evaluate macroscopic and microscopically the gonads of females; to calculate the size at onset maturity in males and females; to determine the geographical distribution of Aegla strinatii with the finding of new populations; to establish the risk of extinction of the species based on criteria established by the IUCN Species Survival Commission. This PhD Thesis is divided into four chapters, each one focused in a subject of the biology of A. strinatii, so that the readers can have a much more dynamic reading. In Chapter 1 there are information about population structure and reproductive biology of A. strinatii. To achieve the results, 867 individuals, being 401 males and 466 females (sexual reason 1:1.16) were sampled with mean carapace length of 19.08 mm (males) and 18.01 mm (females). The reproduction of the species occurred from May to September and the mean fecundity was 186 eggs. The eggs showed variation in both size and color during the embryonic development. The macroscopic analysis of the gonads allowed distinguishing four maturation stages. Histological sections showed a synchronism between those macroscopic stages and the development of ovarian cells. Spermatozoids completely formed were observed in males with carapace length superior to 14.49 mm. In Chapter 2 there is information on the preferential handedness and the relative growth of the first pair of pereopods, carapace length with and without the rostrum, weight and abdomen width of males and females of Aegla strinatii. All comparisons revealed significant differences and demonstrated that claws of A. strinatii are markedly asymmetrical in terms of both length and width in both sexes. The prevalence of a more developed chela was significantly higher in the left chela than in the right one. Positive allometric growth was predominant in all biometric relations of males and females of A. strinatii. In males, all biometric relationship showed significant difference between adult and young specimens. In females only the relative growth of major claw width, abdomen width and weight showed statistical difference between young and adults. The size at the onset of morphometric maturity for males and females was established for each biometric relation studied. Chapter 3 presents the study on the growth in length of Aegla strinatii. The data on the carapace length of males and females were distributed in size classes for animals captured with sieve and trap. Cohorts were recognized using the method of Bhattacharya and the software FISAT II (version 1.2.2). The von Bertalanffy growth function was adjusted on modal CC vs. time plots with the aid of CAJUS software. Estimation of maturation age was based on the maturation size obtained by relative growth analysis (males) (Cap. 2) and on the size which 50% of all females are considered to be mature (Cap. 1). Longevity was based on the CC below which 95% of the sampled individuals were represented. Males and females presented similar growth patterns (L = 27.51, K = 0.73 for males; L = 26.96, K = 0.73 for females). Males and females attained maturation size in 16.5 and 16.8 months respectively. Longevity was estimated as 33.52 months for males and 34.04 for females. The information obtained on the reproductive biology, population dynamics, geographical distribution and possible threats to the population were used to calculate the risk of extinction of A. strinatii, which is the scope of Chapter 4. Through the analysis of all data the species was classified as \"Threatened\". Its geographical distribution is restricted (only three localities), the area of occupation in less than 500 km², the estimated size of adult population was less than 2.500 individuals and a constant decline on the quality of the habitat was detected. This study is a continuation of BIOTA / FAPESP Program that took place from 1998 and 2003. With the end of this program there was an increment of the knowledge of the decapod crustacean fauna from Ribeira do Iguape River Basin. However, the studies on biology and ecology of these crustaceans, particularly eglids, were still scarce. The present contributes to the knowledge increment on the biology and ecology of a aeglid species.

Apesar da vasta literatura sobre os efeitos da perda e fragmentação florestal sobre a biodiversidade, poucos estudos incorporaram o aspecto temporal, ou seja, a história da paisagem, em suas análises. No entanto, o histórico de alterações da paisagem é um dos fatores que, ao ser ignorado, pode levar a interpretação errada dos reais efeitos da perda e fragmentação florestal sobre a diversidade de espécies. Assim, o objetivo desta tese foi avaliar os efeitos do histórico de mudança da paisagem sobre aves e pequenos mamíferos na Mata Atlântica. Para atingir este objetivo eu investiguei (1) a dinâmica de três paisagens fragmentadas de Mata Atlântica entre 1960-1980 e 1980-2000, (2) os efeitos da cobertura florestal passada e atual sobre a riqueza de espécies de espécies e, (3) a plausibilidade de modelos de cobertura vegetal nativa na riqueza de espécies e abundância, considerando ou não a heterogeneidade da vegetação nativa. Para investigar essas questões, foram usados dados de aves e pequenos mamíferos em 53 fragmentos florestais localizados em três paisagens com diferentes proporções de cobertura florestal (10, 30 e 50%) na Mata Atlântica do Planalto Atlântico de São Paulo. Os resultados mostraram que (1) a trajetória da cobertura florestal entre os anos 1960 e 2000 nas três paisagens estudadas foi não-linear e, atualmente, fragmentos florestais consistem de um mosaico de florestas com diferentes idades de regeneração, (2) a existência do débito de extinção e do crédito de espécies, assim como o potencial para o seu pagamento futuro, depende não só da trajetória de cobertura florestal, mas também da cobertura florestal remanescente na escala da paisagem, e (3) a heterogeneidade da vegetação nativa desempenha um papel importante na definição da riqueza de espécies e abundância e que as respostas a essa heterogeneidade são definidas pelos requerimentos de habitat e dependem de cobertura florestal da paisagem. / Despite the extended literature on the effects of forest loss and fragmentation on biodiversity, few studies incorporated the temporal aspect, i.e. the history of change of habitat amount and configuration over time at a given landscape, in the analysis. However, ignoring landscape change history might lead to inaccurate interpretation of the impact of forest loss and fragmentation on species diversity. Thus, the aim of this thesis was to evaluate the effects of landscape change history on birds and small mammals in the Atlantic Forest. To achieve this aim I investigated (1) the land-use and land-cover change dynamics in Atlantic Forest fragmented landscapes between 1960s-1980s and 1980s-2000s, (2) the effects of historical and present-day forest cover on species richness and, (3) the potential of explaining species richness and abundance patterns by inclusion or exclusion of present native vegetation heterogeneity in model frameworks. To address these objectives I used data on birds and small mammals in 53 forest fragments from three landscapes with different proportions of forest cover (10, 30 and 50%) in the Atlantic Forest of Brazil. The results showed that (1) forest cover trajectory between the 1960s and 2000s at the three study landscapes was non-linear and that individual forest patches currently consist of a mosaic of different forest age classes, (2) the existence of extinction debt and species credit as well as the potential for their future payment depends not only on forest cover trajectory but also on the present amount of remaining forest cover at the landscape scale, and (3) the heterogeneity within native vegetation plays an important role in defining species richness and abundance in fragmented landscapes and responses to this heterogeneity are defined by habitat requirements and depend on forest cover at landscape scale.

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective. These hypotheses were tested using data from shell size measurements and morphology primarily from molluscs and brachiopods from both North America and Denmark.. Morphological differences were evaluated using Elliptical Fourier Analysis (EFA) of outline shape in conjunction with Principle Components and Canonical Variate Analysis. The first part of this study provides a detailed methodology for data collection and analysis. New methods were developed which display promise in improving the degree to which differences and similarities in shape can be elucidated using EFA. These methods were then employed to test hypotheses of morphological change through minor events of local significance in the Florida Neogene and following the K/Pg mass extinction. Data sources for the K/Pg mass extinction were from high resolution (10 cm intervals) collection of bulk samples from the Brazos River in Texas as well as reposited museum specimens for the Braggs locality in Alabama and Danish samples. Study of size and evolution through more minor local events in the fossil record entailed measurements and shape analysis of left valves of bivalves from the genus Chine. Various environmental changes occurred at variousmpoints during the Neogene in Florida Neogene, most profoundly documented during the Plio-Pleistocene with accompanying faunal turnover. TheChione specimens analyzed were derived from a discontinuous sequence encompassing ~18 Ma and represent material from the Miocene Chipola Formation through to the Recent. The size of Chione increased from the Miocene to the Pliocene and then decreased from the Pliocene into the Pleistocene possibly due to lower primary productivity. The later part of the Pleistocene into the Recent was characterized by increased size relative to the early Pleistocene and size was stable through this interval. Morphologically, Chione changed in shape from the Miocene to the Pliocene, but remained in stasis from the Pliocene to the Recent suggesting that stabilizing selection may work well during periods of rapid, minor, environmental perturbations. There were a number of global changes occurring within the late Maastrichtian pr and the results of size measurements of molluscs demonstrate a decrease in size prior to the K/Pg mass extinction in Texas likely in response to a number of global scale events occurring towards the close of the Cretaceous that was also associated with morphological evolution in the small bivalve Breviarca webbervillensis. Paleocene material from Texas was dominated by smaller, newly evolved allochthonous grazing gastropods. These gastropods are thought to be newly evolved lineages as their first occurrence is marked in the Paleocene. Smaller sized nuculid bivalves were also a prominent feature in the Texas Paleocene and showed a rapid size beginning 40 cm above the boundary clay. At Braggs, Alabama, two groups, gastropods and oysters showed decreases in size across the boundary, and these changes are most likely a product of animpoverished Paleocene ecosystem. The pectinids were the only group of bivalve mollusc to xii reduce in size following extinction in Denmark most likely in response to a reduction in bryozoan substrate which resulted in a very soft coccolith-derived mud substrate in the mass extinction's aftermath. Size measurements from the Danish brachiopods showed reductions in size across the boundary in all genera except Rugia. There was a marked size reduction in specimens from the upper Maastrichtian at Stevns Klint as compared to the lower Maastrichtian at Mons Klint. The reasons for this are most likely due to lower temperatures at Stevns based on isotope data as well as lower productivity evidenced by lower δ13C values. There was a change in morphology for Terebratulina chrysalis in the earliest Paleogene due to shifted selective pressures favoring increased surface area as an adaptation to softer substrates. Size reduction within Danish sequences is evolutionary in nature as the Danian is characterized by different species within existing Maastrichtian genera and two new genera. The results of this study demonstrate that changes in body size can be a result of evolution from changing selective pressures as well as ecological perturbations. Distinguishing evolutionary forcings from ecological requires the collection and understanding of morphological data. Changes in size for Terebratulina chrysalis could have easily been interpreted as ecological were it not for morphological results showing the changes in surface area resulting from changing selective pressure. Late Cretaceous changes in climate and sea level produced observable changes in size and morphology in Breviarca webbervillensis. Potential size selectivity of the K/Pg mass extinction failed to account for any of the patterns observed in the data. Gryphaeid oysters in Denmark would have been a perfect candidate to support conclusions of size selectivity as they were the largest molluscs measured in this study and survived mass extinction.

We investigate the relation between gas and star formation in subgalactic regions, similar to 360. pc to similar to 1.5. kpc in size, within the nearby starburst dwarf NGC 4449, in order to separate the underlying relation from the effects of sampling at varying spatial scales. Dust and gas mass surface densities are derived by combining new observations at 1.1. mm, obtained with the AzTEC instrument on the Large Millimeter Telescope, with archival infrared images in the range 8-500 mu m from the Spitzer Space Telescope and the Herschel Space Observatory. We extend the dynamic range of our millimeter (and dust) maps at the faint end, using a correlation between the far-infrared/millimeter colors F(70)/F(1100) (and F(160)/F(1100)) and the mid-infrared color F(8)/F(24) that we establish for the first time for this and other galaxies. Supplementing our data with maps of the extinction-corrected star formation rate (SFR) surface density, we measure both the SFR-molecular gas and the SFR-total. gas relations in NGC 4449. We find that the SFR-molecular. gas relation is described by a power law with an exponent that decreases from similar to 1.5 to similar to 1.2 for increasing region size, while the exponent of the SFR-total. gas relation remains constant with a value of similar to 1.5 independent of region size. We attribute the molecular law behavior to the increasingly better sampling of the molecular cloud mass function at larger region sizes; conversely, the total gas law behavior likely results from the balance between the atomic and molecular gas phases achieved in regions of active star formation. Our results indicate a nonlinear relation between SFR and gas surface density in NGC 4449, similar to what is observed for galaxy samples.

The purpose of the present research is to develop and apply an experi- mental technique for measuring the size of nanoparticles and nanodroplets in a flow environment. The developed non-intrusive, optical method is called Light Extinction Spectroscopy (LES) and it allows to determine the size of particles from measuring their light transmission spectrum on the Ultraviolet-Near-Infrared range. The most crucial part of the develop- ment work is to obtain a reliable data processing method, which is based on the regularized solution of an ill-conditioned inverse problem. The de- veloped method is first tested using synthetic data, which allows to deter- mine the measurement range and also the measurement errors caused by various sources. This is followed by performing laboratory experiments for validating the LES technique. Validation measurements using calibrated particles and a reference instrument shows that sizing errors are in the order of 5-10%. Afterwards, the technique is applied for characterizing the Brownian coagulation process of nanodroplets, where the growth rate of droplets is successfully measured and is found to agree with theoreti- cal expectations. Next, the LES technique is applied to coagulating solid particles, where the growth rate of these complex non-spherical objects is retrieved. Finally, a particle monolayer is deposited on an air-water inter- face and it is shown that the LES technique can retrieve the particle-water contact angle, which allows the characterization of nanoparticle wettabil- ity and the study of the related interesting physical phenomena. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Les peptides pénétrants (CPP) se caractérisent par deux propriétés : ils pénètrent dans l'espace intracellulaire et favorisent l'internalisation de cargaisons moléculaires auxquelles ils sont associés. Si les CPP sont très utilisés comme vecteurs en recherche fondamentale, la méconnaissance des mécanismes de pénétration et de leurs distributions intracellulaires limite leur utilisation thérapeutique. Il est admis que les CPP et leurs cargaisons sont internalisés par transport actif (endocytose) et par transport passif (translocation directe). J'ai étudié la translocation directe à l'échelle moléculaire en utilisant des membranes modèles. Les CPP usuels sont internalisés et permettent l'accumulation de cargaisons dans des vésicules unilamellaires. J'ai alors démontré que la translocation directe se déroule via la formation de complexes neutres et hydrophobes CPP-phospholipides.La pénétration intracellulaire des CPP est le plus souvent étudiée par microscopie confocale. J'ai démontré que des fortes concentrations locales de CPP induit une auto-inhibition de leur fluorophore. Cet artefact a conduit à des erreurs d'interprétation dans la littérature quant à la localisation des CPP. Un protocole permettant de révéler la fluorescence éteinte a été proposé et conduit à réévaluer la localisation subcellulaire des CPP ainsi que l'importance relative des mécanismes d'internalisation.Ces résultats ont permis de développer rationnellement de nouveaux vecteurs pénétrants : les oligoarginines acylées par des chaînes grasses dont des insaturations sont de stéréochimie cis. Leur internalisation passive particulièrement importante conduit à la libération de la cargaison dans le cytosol. / Cell penetrating peptides (CPPs) are short cationic sequences capable of shuttling bioactive cargoes into eukaryotic cells. If CPPs are common delivery tools in basic research, their therapeutic use is currently limited because their internalization mechanisms and intracellular distributions remain to be elucidated. In living cells there is evidence for both endocytosis of the CPPs and for “direct translocation”, an energy-independent uptake pathway. I analyzed the direct translocation phenomenon at the molecular level with model membranes. CPPs are internalized into large unilamellar vesicles and trigger the internalization of various cargoes. I then demonstrated that direct translocation occurs through membranes via the formation of a neutral and hydrophobic CPP-anionic phospholipids complex. CPPs internalization is mostly analyzed by confocal microscopy. I demonstrated that fluorescence self-quenching occurs if fluorescently labeled CPPs are locally too concentrated. This severe artifact led to misinterpretation of the subcellular distribution of CPPs. I developed a reliable procedure to avoid this artifact and ranked subcellular regions of living cells depending on their CPP concentration. As a result, I was able to rationalize the subcellular distribution of CPPs and to deduce their penetration mechanisms. The studies that I performed provided valuable information that I used to design a new family of delivery vectors: minimalist oligoarginines peptides acylated by unsaturated fatty acids (cis unsaturations). The direct translocation of these lipopeptides is particularly important yielding to an efficient delivery of a cargo inside the cytosol of living cells.

Response Interruption and Redirection (RIRD) was compared to no-interaction, continuous neutral sound, and contingent neutral sound in order to determine the mechanism by which RIRD functions to suppress vocal stereotypy in children diagnosed with autism spectrum disorder. A neutral sound was determined through the use of a preference assessment of various sounds. Use of a neutral sound did not suppress vocal stereotypy in participants. Manipulating the amount of time with a sound playing did not have an effect on vocal stereotypy either. These results suggest that it is unlikely that RIRD suppresses vocal stereotypy through an extinction-like effect. Rather, it is more likely that RIRD suppresses vocal stereotypy through a punishment-like effect.