982 resultados para Merlin, Ant. Christ.
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The queenless ponerine ant Diacamma ceylonense and a population of Diacamma from the Nilgiri hills which we refer to as `nilgiri', exhibit interesting similarities as well as dissimilarities. Molecular phylogenetic study of these morphologically almost similar taxa has shown that D ceylonense is closely related to `nilgiri' and indicates that `nilgiri' is a recent diversion in the Diacamma phylogenetic tree. However, there is a striking behavioural difference in the way reproductive monopoly is maintained by the respective gamergates (mated egg laying workers), and there is evidence that they are genetically differentiated, suggesting a lack of gene flow To develop a better understanding of the mechanism involved in speciation of Diacamma, we have analysed karyotypes of D. ceylonense and `nilgiri' In both, we found surprising inter-individual and intra-individual karyotypic mosaicism. The observed numerical variability, both at intra-individual and inter-individual levels, does not appear to have hampered the sustainability of the chromosomal diversity in each population under study Since the related D. indicum, displays no such intra-individual or inter-Individual variability whatsoever under identical experimental conditions, these results are unlikely to he artifacts. Although no known mechanisms can account for the observed karyotypic variability of this nature, we believe that the present findings on the ants under study would provide opportunities for exciting new discoveries concerning the origin, maintenance and significance of intra-individual and inter-individual karyotypic mosaicism.
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In a complex multitrophic plant-animal interaction system in which there are direct and indirect interactions between species, comprehending the dynamics of these multiple partners is very important for an understanding of how the system is structured. We investigated the plant Ficus racemosa L. (Moraceae) and its community of obligatory mutualistic and parasitic fig wasps (Hymenoptera: Chalcidoidea) that develop within the fig inflorescence or syconium, as well as their interaction with opportunistic ants. We focused on temporal resource partitioning among members of the fig wasp community over the development cycle of the fig syconia during which wasp oviposition and development occur and we studied the activity rhythm of the ants associated with this community. We found that the seven members of the wasp community partitioned their oviposition across fig syconium development phenology and showed interspecific variation in activity across the day-night cycle. The wasps presented a distinct sequence in their arrival at fig syconia for oviposition, with the parasitoid wasps following the galling wasps. Although fig wasps are known to be largely diurnal, we documented night oviposition in several fig wasp species for the first time. Ant activity on the fig syconia was correlated with wasp activity and was dependent on whether the ants were predatory or trophobiont-tending species; only numbers of predatory ants increased during peak arrivals of the wasps.
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Tutkielman tarkoituksena on tutkia Mel Gibsonin elokuvaa The Passion of the Christ. Tarkastelussa mukana on myös Gibsonin muu tuotanto. Tutkielma edustaa poikkitieteellistä lähestymistapaa käyttäen eksegetiikan apuvälineitä kuten lähdekritiikkiä, mutta myös elokuvatutkimuksen välineitä. Tutkimuskysymyksiä nousee lähinnä kaksi, joista seuraa kolmas kysymys: 1. Onko elokuva juutalaisvastainen? Tarkastelen lähdekritiikin avulla mitä evankeliumeja Gibson on käyttänyt elokuvassaan. Mitä muita lähteitä hän on käyttänyt? Mikä on Gibsonin omaa ilmaisua? 2. Miksi elokuva on väkivaltainen? Mitä väkivalta palvelee elokuvassa? 3. Millainen on elokuvamaailman konflikti? Pohdin elokuvamaailman sisälle rakennettua konfliktia, mutta viittaan sillä myös konfliktiin, jonka elokuva itsessään synnytti. Kysymysten ratkaisu vaatii elokuvassa käytettyjen lähteiden tutkimista, mutta myös kysymysten tarkastelua osana laajempaa kokonaisuutta, jossa on mukana koko Gibsonin elokuvatuotanto. On myös selvää, ettei Gibson ole yhtä kuin hänen elokuvansa, mutta toisaalta hänen elokuviaan ei voi tarkastella irrotettuna ohjaajasta itsestään. Ensimmäisessä luvussa tarkastelen elokuvaa ilmiönä ja elokuvasta käytyä ennakkokeskustelua. Luvussa kaksi tarkastelen Gibsonin taustaa. Millaisista lähtökohdista Gibson lähti tekemään elokuvaa? Luvussa kolme esittelen käsikirjoituksesta alkavan elokuvan yleisen tuotantoprosessin. Tutkielman päälähteenä olen käyttänyt Brentanon kirjaa The Dolorous Passion of Our Lord Jesus Christ. Kirja pohjautuu 1800-luvulla eläneen katolisen nunnan, Anne Catherine Emmerichin näkyihin. Luvussa neljä tarkastelen Gibsonin muuta tuotantoa, ja tuon keskusteluun mukaan Scorsesen elokuvan Jeesuksesta. Gibsonin muu tuotanto on jäänyt tutkijoilta liian vähälle huomiolle. Elokuva The Passion of the Christ on nähtävä osana Gibsonin muuta tuotantoa. Näin ollen elokuvaa The Passion of the Christ voidaan ymmärtää paremmin. Luvussa viisi käyn elokuvan The Passion of the Christ läpi kappale kerrallaan tutkimalla, mitä lähteitä Gibson on käyttänyt elokuvassaan. Mitä hän on ottanut evankeliumeista, mitä Emmerichiltä ja mikä on hänen omaa ilmaisuaan? Luvussa kuusi käyn läpi elokuvan vastaanottoa niin raamatuntutkijoiden kuin suuren yleisön parissa. Tutkielmassa todetaan, ettei Gibson ole antisemitisti, vaan ksenofobinen rasisti. Hänen elokuvansa ovat ksenofobisesti rasistisia. Gibsonin kaikista elokuvista on löydettävissä itseään toistavia piirteitä, joissa esiintyy muukalaiskammoa ja väkivaltaa. Gibsonin nimittäminen antisemitistiksi ei tekisi Gibsonille oikeutta. Juutalaiset ovat vain osa laajempaa kokonaisuutta. Väkivalta palvelee kaikissa elokuvissa uuden, Jumalan valtakunnan syntymistä. Konflikti syntyy uuden ja vanhan valtakunnan kansalaisten välillä. Uhrien veren kautta syntyy Jumalan valtakunta. Johtopäätöksillä on merkitystä niin Gibsonin kuin hänen elokuviensa ymmärtämiselle. Elokuvan The Passion of the Christ tulevissa tutkimuksissa on otettava huomioon, ei vain Gibsonin tausta ja lähteet, vaan myös Gibsonin muu elokuvatuotanto.
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Neurofibromatosis 2 (NF2) is an autosomal dominant disorder manifested by the formation of multiple benign tumors of the nervous system. Affected individuals typically develop bilateral vestibular schwannomas which lead to deafness and balance disorders. The syndrome is caused by inactivation of the NF2 tumor suppressor gene, and mutation or loss of the NF2 product, merlin, is sufficient for tumorigenesis in both hereditary and sporadic NF2-associated tumors. Merlin belongs to the band 4.1 superfamily of cytoskeletal proteins, which also contain the related ezrin, radixin, and moesin (ERM) proteins. The ERM members provide a link between the cell cytoskeleton and membrane by connecting membrane-associated proteins to actin filaments. By stabilizing complexes in the cell cortex, the ERMs modulate morphology, growth, and migration of cells. Despite their structural homology, overlapping subcellular distribution, direct molecular association, and partial overlap of molecular interactions, merlin and ezrin exert opposite effects on cell proliferation. Merlin suppresses cell proliferation, whereas ezrin expression is linked to oncogenic activity. We hypothesized that the regions which differ between the proteins might explain merlin s specificity as a tumor suppressor. We therefore analyzed the regions, which are most diverse between merlin and ezrin; the N-terminal tail and the C-terminus. To determine the properties of the C-terminal region, we studied the two most predominant merlin isoforms together with truncation variants similar to those found in patients. We also focused on the evolutionally conserved C-terminal residues, E545-E547, that harbor disease causing mutations in its corresponding DNA sequence. In addition to inhibiting cell proliferation, merlin regulates cytoskeletal organization. The morphogenic properties of merlin may play a role in tumor suppression, since patient-derived tumor cells demonstrate cytoskeletal abnormalities. We analyzed the mechanisms of merlin-induced extension formation and determined that the C-terminal region of amino acids 538-568 is particularly important for the morphogenic activity. We also characterized the role of C-terminal merlin residues in the regulation of proliferation, phosphorylation, and intramolecular associations. In contrast to previous reports, we demonstrated that both merlin isoforms are able to suppress cell proliferation, whereas C-terminally mutated merlin constructs showed reduced growth inhibition. Phosphorylation serves as a mechanism to regulate the tumor suppressive activity of merlin. The C-terminal serine 518 is phosphorylated in response to both p21-activated kinase (PAK) and protein kinase A (PKA), which inactivates the growth inhibitory function of merlin. However, at least three differentially phosphorylated forms of the protein exist. In this study we demonstrated that also the N-terminus of merlin is phosphorylated by AGC kinases, and that both PKA and Akt phosphorylate merlin at serine 10 (S10). We evaluated the impact of this N-terminal tail phosphorylation, and showed that the phosphorylation state of S10 is an important regulator of merlin s ability to modulate cytoskeletal organization but also regulates the stability of the protein. In summary, this study describes the functional effect of merlin specific regions. We demonstrate that both S10 in the N-terminal tail and residues E545-E547 in the C-terminus are essential for merlin activity and function.
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1. Habitat fragmentation, anthropogenic disturbance and the introduction of invasive species are factors thought to structure ant assemblages. To understand responses of the ant community to changes in the environment, ants are commonly categorised into functional groups, a scheme developed and based on Australian ants. 2. Behaviourally dominant and aggressive ants of the dominant dolichoderinae functional group have been suggested to structure the ant assemblages in arid and semi-arid habitats of these regions. Given the limited geographical distribution of dominant dolichoderinae, it is crucial to determine the responses of the ant community to changes in the environment in their absence. 3. This study addresses this less studied aspect by considering the associations of ants of Western Ghats, India, with habitat, anthropogenic disturbance and introduced ants. We determined how ant functional groups respond to these factors in this region, where dominant dolichoderines are naturally absent, and whether responses are consistent with predictions derived from the ant functional group scheme. 4. This study provides new information on ant assemblages in a little-studied region. As in other parts of the world, ant assemblages in Western Ghats were strongly influenced by habitat and disturbance, with different functional groups associated with different habitats and levels of disturbance. 5. No functional group showed evidence of being influenced by the abundance of introduced species. In addition, predictions of negative interactions between functional groups were not supported. Our findings suggest that abiotic factors are universal determinants of ant assemblage structure, but that competitive interactions may not be.
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Ant-plant interactions often are mediated by extrafloral nectar (EFN) composition that may influence plant visitation by ants. Over a 300 km range in the Indian Western Ghats, we investigated the correlation between the EFN composition of the myrmecophytic ant-plant Humboldtia brunonis (Fabaceae) and the number and species of ants visiting EFN. EFN composition varied among H. brunonis populations and between plant organs (floral bud vs. young leaf EFN). In general, EFN was rich in sugars with small quantities of amino acids, especially essential amino acids, and had moderate invertase activity. In experiments at the study sites with sugar and amino acid solutions and with leaf or floral bud EFN mimics, dominant EFN-feeding ants differentiated between solutions as well as between mimics. The castration parasite Crematogaster dohrni (northern study site) was the least selective and did not exhibit any clear feeding preferences, while the largely trophobiont-tending non-protective Myrmicaria brunnea (middle study site) preferred higher sucrose concentrations and certain essential/non-essential amino acid mixtures. The mutualistic Technomyrmex albipes (southern study site) preferred sucrose over glucose or fructose solutions and consumed the leaf EFN mimic to a greater extent than the floral bud EFN mimic. This young leaf EFN mimic had low sugar concentrations, the lowest viscosity and sugar: amino acid ratio, was rich in essential amino acids, and appeared ideally suited to the digestive physiology of T. albipes. This preference for young leaf EFN may explain the greater protection afforded to young leaves than to floral buds by T. albipes, and may also help to resolve ant-pollinator conflicts. The differential response of dominant ants to sugar, amino acids, or solution viscosity suggests that plants can fine-tune their interactions with local ants via EFN composition. Thus, EFN can mediate local partner-choice mechanisms in ant-plant interactions.
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Protection-based ant-plant mutualisms may vary in strength due to differences in ant rewards, abundance of protective ants and herbivory pressure. We investigated geographical and temporal variation in host plant traits and herbivory pressure at five sites spanning the distribution range of the myrmecophyte Humboldtia brunonis (Fabaceae) in the Indian Western Ghats. Southern siteshad, onaverage, 2.4 times greater abundance of domatia-bearing individuals, 1.6 times greater extrafloral nectary numbers per leaf, 1.2 times larger extrafloral nectary sizes, 2.2 times greater extrafloral nectar (EFN) volumes and a two-fold increase in total amino acid and total sugar concentrations in EFN compared with northern sites. Astrong protection-based mutualismwith ants occurred at only one southern site where herbivory was highest, suggesting that investments in attracting ants correlate with anti-herbivore benefits gained from the presence of protective ants. Our results confirm a temporally stable north-south gradient in myrmecophytic traits in this ant-plant as several of these traits were re-sampled after a 5-y interval. However, the chemical composition of EFN varied at both spatial and short-term temporal scales suggesting that only repeated measurements of rewards such as EFN can reveal the real spectrum of trait variation in an ant-plant mutualistic system.
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1. How a symbiosis originates and is maintained are important evolutionary questions. Symbioses in myrmecophytes (plants providing nesting for ants) are believed to be maintained by protection and nutrients provided by specialist plant-ants in exchange for nesting spaces (called domatia) and nourishment offered by ant-plants. However, besides the benefits accrued from housing protective ants, the mechanisms contributing to the fitness advantages of bearing domatia have rarely been examined, especially because the domatia trait is usually constitutively expressed, and many myrmecophytes have obligate mutualisms with single ant species resulting in invariant conditions. 2. In the unspecialized ant-plant Humboldtia brunonis (Fabaceae) that offers extrafloral nectar to ants, only some plants produce domatia in the form of hollow internodes. These domatia have a self-opening slit making them more prone to interlopers and are occupied mostly by non-protective ants and other invertebrates, especially arboreal earthworms. The protection mutualism with ants is restricted in geographical extent, occurring only at a few sites in the southernmost part of this plant's range in the Western Ghats of India. 3. We examined nutrient flux from domatia residents to the plant using stable isotopes. We found that between 9% (earthworms) and 17% (protective or non-protective ants) of nitrogen of plant tissues nearest the domatium came from domatia inhabitants. Therefore, interlopers such as earthworms and non-protective ants contributed positively to the nitrogen budget of localized plant modules of this understorey tree. N-15-enriched feeding experiments with protective ants demonstrated that nutrients flowed from domatia inhabitants to nearby plant modules. Fruit set did not differ between paired hand-pollinated inflorescences on domatia and non-domatia bearing branches. This was possibly due to the nutrient flux from domatia to adjacent branches without domatia within localized modules. 4. This study has demonstrated the nutritive role of non-protective ants and non-ant invertebrates, hitherto referred to as interlopers, in an unspecialized myrmecophyte. Our study suggests that even before the establishment of a specialized ant-plant protection mutualism, nutritional benefits conferred by domatia inhabitants can explain the fitness benefits of bearing domatia, and thus the maintenance of a trait that facilitates the establishment of a specialized ant-plant symbiosis.
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The ant-plant Humboldtia brunonis secretes extrafloral nectar (EFN) despite the lack of antiherbivore protection from most ants. EFN was richer in composition than phloem sap and honeydew from untended Hemiptera on the plant, suggesting that EFN could potentially distract ants from honeydew, since ants rarely tended Hemiptera on this plant.
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João da Fonseca nasceu em Viana do Além-Tejo, em 1632, e morreu em Lisboa, em 1701. Foi professor de Filosofia na Universidade de Evora e missionário em várias vilas e cidades e mestre do noviciado de Coimbra. Distinguiu-se em seu tempo na Teologia Ascética, como se comprova nas obras que nos deixou, as quais são ainda apreciadas pela correção e propriedade da linguagem. Em ‘Escola da Doutrina Christã’, o autor ensina o verdadeiro caminho da vida, resumindo nesta leitura tudo o que em muitos volumes ensina a teologia especulativa e moral. Todas as matérias de que trata são confirmadas com muito se notáveis exemplos. Trata-se, aqui, da primeira edição, impressa em 1688. Tem-se noticia de uma segunda edição publicada pela Oficina da Universidade, em 1750.
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TÃtulo Uniforme : Corpus Juris Civilis. Institutas.