173,295 research outputs found
Ground States for NLS on Graphs: A Subtle Interplay of Metric and Topology
We review some recent results on the minimization of the energy associated to the
nonlinear Schrödinger Equation on non-compact graphs. Starting from seminal results given
by the author together with C. Cacciapuoti, D. Finco, and D. Noja for the star graphs, we
illustrate the achiements attained for general graphs and the related methods, developed
in collaboration with E. Serra and P. Tilli. We emphasize ideas and examples rather than
computations or proofs
Os significados e representações atribuídos aos cursos d'agua da bacia do Rio Criciúma (SC) desde 1880 até 2009 e suas influências na configuração da paisagem
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Geografia, Florianópolis, 2010O trabalho tem por objetivo compreender como foram construídos os significados atribuídos aos cursos d'água nas diferentes fases do processo de ocupação das terras da bacia do rio Criciúma (SC), desde o processo de colonização em 1880 até os dias atuais. O significado dos objetos norteia a relação dos indivíduos entre si e com seu meio. No caso estudado, a relação de diferentes grupos sociais que ocuparam a bacia do rio Criciúma ao longo do tempo depende do significado atribuído a este recurso, o que reflete nas formas de apropriação dos rios. O significado é uma construção mental acerca de um objeto e essa construção depende de valores, percepções, experiências e são abstratos. Quando há tentativa de comunicá-lo, perde-se alguma parte do seu conteúdo. A sua expressão dá-se por meio de diferentes linguagens, que na realidade representam este significado. As formas de apropriação do rio são também representações de significados atribuídos pelos grupos sociais apropriadores a este elemento da paisagem. A partir dos conceitos e abordagens da Geografia Cultural, faz-se um estudo das representações, incluindo as formas de apropriação, em diferentes contextos sócio-econômicos culturais pelas quais passou o processo de ocupação humana da bacia. Para compreender os significados e suas representações foram pesquisadas diferentes linguagens a partir de entrevistas, pesquisas bibliográficas, fotografias, mapas, leis e normas municipais. Três períodos históricos foram identificados durante o processo de ocupação da bacia, com distintas formas de apropriação dos cursos d'água. O primeiro período vai da colonização até 1930, quando as atividades econômicas predominantes eram a agricultura, o comércio e as pequenas manufaturas. Nessa época, o rio era um elemento referencial para as pessoas, pois se constituía no eixo norteador do processo de colonização e do traçado urbano, gerador de força motriz para os engenhos e atafonas e para abastecimento de água potável. No segundo período, de 1930 até 1950, a principal atividade econômica era a exploração de carvão, que utilizava o rio para a lavagem ou beneficiamento do desse mineral, drenagem das áreas ácidas, com consequente contaminação, assoreamento por deposição de material fino do carvão e desvios dos cursos d'água. Associada à mineração, houve a vinda de um contingente populacional acentuado para o município, e essas pessoas não tinham o rio Criciúma e seus afluentes como uma referência dos seus espaços vividos. Por isso, não havia problema em contaminá-lo com esgotos domésticos, mesmo aqueles que não estavam contaminados com carvão. O rio Criciúma passa a ter um significado negativo de sujo e mau cheiroso, por causa da apropriação para o despejo de efluentes do carvão, esgotos domésticos e resíduos sólidos. O terceiro período ocorre a partir de 1950, a bacia começa a ser intensamente urbanizada e, no final dos anos de 1960, inicia o processo de verticalização no alto e médio vale do rio Criciúma. Muitos trechos do rio e seus afluentes foram canalizados com contenção de margem e fundo e alguns até recobertos para a apropriação do espaço dos seus leitos e para resolver os problemas do cheiro exalado e das inundações. Partes dos rios desapareceram da paisagem da bacia por causa das canalizações e recobrimentos e passaram a não ter significado, pois não existem aos olhos de muitos moradores. Contudo, nos momentos de precipitações elevadas, o rio volta a se mostrar em forma de inundações, gerando na população uma sensação de medo. Nesses períodos o rio Criciúma e seus afluentes têm um significado para população, mas este significado esta ligado a sentimentos ruins. Conclui-se que, em cada período identificado, o rio Criciúma como elemento da paisagem recebeu distintos significados, traduzidos pelas representações, os quais são materializados por diferentes formas de apropriação
Paraprososthenia adami Brandt 1970
adami, Paraprososthenia Brandt, 1970 Paraprososthenia adami Brandt, 1970: 189–190 (pl. 13, fig. 7 + text fig. 7). Gastropoda, Pomatiopsidae Probable paratype: MZSP 95923. Locality: Cambodia, Mekong River at Sambor (type locality), N of Kratie, 6 Apr. 1969. Preservation: Dry. Remarks: Former Jens Hemmen Collection. Measurements and data on the specimen’s label correspond to the 70-specimen paratype lot originally catalogued as SMRL 16302.Published as part of Cavallari, Daniel C., Dornellas, Ana Paula S. & Simone, Luiz Ricardo L., 2016, Second annotated list of type specimens of molluscs deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil, pp. 1-59 in European Journal of Taxonomy 213 on page 3, DOI: 10.5852/ejt.2016.213, http://zenodo.org/record/384012
Affordances and practices: The case of YouTube video responses
The introduction of the Video Responses functionality in YouTube in March 2006 paved the way for video interaction, a new type of interaction, in which videos respond to other videos. A previous work (Adami, 2010) analysed the results of a 14-month period of monitoring of the Most Responded Videos chart, categorized the videos with the largest number of responses over the period and investigated the main video interaction practices by examining a sample video-thread for each typology. Drawing on this work, the present paper discusses selected examples of video exchanges that illustrate non-deterministic and recursive interaction between the affordances of the Video Responses option and the ways in which these are actualized by sign-making practices. The range of possible video interaction practices is determined by the set of affordances (Kress, van Leeuwen, 2006), what the Responses option enables/encourages interactants to do or prevents/discourages them from doing, both materially and socially. Within this range of possibilities, participants exploit affordances in unexpected ways, according to their diversified and
sometimes conflicting interests. When institutionalized, these innovative practices lead to structural changes in the affordances themselves, in much the same way as Saussurean acts of parole bring about innovations in langue (Saussure, 1916/1931). As with language here, too, any innovative act of sign-making that becomes socially established is the result of the dominance (both in frequency and prestige) of a specific practice from among the set of many existing and conflicting practices. Eventually, some norms become institutionalized; this depends on sociocultural, as well as material, factors and forces; the cause-effect relationship is never deterministic; it cannot be predicted beforehand but only explained retrospectively. Once institutionalized, the innovation in
its turn paves the way for further creative and unexpected uses of the system’s renewed possibilities. Analysis of the patterns of relatedness in the video exchanges arising from this interrelationship, indicates that creative uses of the affordances lead to acceptability of exchanges which disregard traditional standards of coherence. As we shall see from what follows, far from giving rise to communicative failure, exchanges that disregard interlocutors’ intended meanings bring about video interaction successfully. Since video interaction shares its affordances with all other online semiotic spaces and digital forms
of text production, the practices observed here may well be indicative of broader phenomena characterizing communication in digital environments
Plasmodium chabaudi adami: vaccine antigens and antigenic variation
Deposited with permission of the author © 2003 Dr. Eva BucsuThere is an abundance of information available on the molecular mechanisms of antigenic variation in Plasmodium falciparum. The variant antigen PfEMP1, which mediates antigenic variation as well as cytoadherence and rosetting, has been extensively characterised. Genes coding for the antigen belong to the gene family var, and several var genes have been cloned and characterised. The rodent malaria parasite P. chabaudi is a widely studied in vivo model for P. falciparum. The P. c. chabaudi AS parasite strain has been shown to exhibit antigenic variation and the variant antigen has been detected by surface fluorescence. As with P. falciparum, there is a link between antigenic variation and cytoadherence, however genes coding for the variant antigen in P. chabaudi have not been cloned to date. Therefore, potentially useful in vivo experiments on antigenic variation are restricted. In this thesis it is shown for the first time that the P. c. adami DS parasite strain also exhibits antigenic variation.
Chapter 3 describes efforts to locate genes coding for variant antigens in P. c. adami DS. The main strategy involved a genome survey, by sequencing and analysing randomly selected clones from a P. c. adami DS genomic library. DNA sequences were compared to Plasmodium spp. sequence databases to look for similarity to var genes or other genes encoding variant antigens. Of the 297 clones analysed none had significant sequence similarity to genes coding for variant antigens. However, in a small proportion of sequences some similarity to var genes was noted. Several genes of potential interest were identified, most importantly the gene coding for the vaccine candidate rhoptry associated protein 1 (RAP1), which was subsequently cloned and characterised. Further attempts to locate var gene homologues in P. c. adami involved amplification of P. c. adami genomic DNA using degenerate oligonucleotide primers corresponding to conserved regions of var genes. This strategy proved to be unsuccessful, most likely due to lack of sequence similarity between P. falciparum and P. c. adami genes. In several vaccination studies with the apical membrane antigen 1 (AMA1) of P. c. adami DS, mice were significantly protected against homologous parasite challenge. However, some mice developed late, low-level breakthrough parasitaemias. In Chapter 4, the characterisation of two such breakthrough parasitaemias is described. The ama1 genes of the breakthrough parasites were found to be identical to the ama1 gene of the parental parasites. Similarly, no alteration in AMA1 expression was observed. However, the breakthrough parasites were found to be more resistant than the parental parasites to the effects of passive immunisation with rabbit antisera to AMA1, RAP1 and possibly also MSP119. P. chabaudi infections in mice have been previously shown to consist of a primary parasitaemia followed by a short period of subpatency, and a recrudescent parasitaemia. In surface immunofluorescence studi
Chapter 4 describes similar surface immunofluorescence assays carried out with P. c. adami infected erythrocytes, and quantitation of fluorescence by flow cytometry. As with P. c. chabaudi, the recrudescent parasites were found to be antigenically distinct from the primary parasitaemia, indicating that antigenic variation had taken place. Because breakthrough parasites from the AMA1 vaccination trial were similar to recrudescences in peak and duration, we hypothesised that breakthrough parasitaemias, like recrudescent parasitaemias, occur as a result of antigenic variation. In Chapter 4 it was shown by surface immunofluorescence and flow cytometry using hyperimmune sera raised against different parasite populations, that breakthrough parasites express antigens on the surface of late trophozoite- and schizont infected erythrocytes that differ from those expressed by the parental and recrudescent parasites. These results support the hypothesis that switching of the variant antigen on the infected erythrocyte surface enables parasites to evade protective antibody responses directed against merozoite antigens.
Chapter 5 describes the cloning and characterisation of P. c. adami RAP1 which was identified in the process of the genomic survey described in Chapter 3, as well as P. berghei RAP1. Both rodent parasite orthologues of RAP1 were found to have 30% sequence similarity to P. falciparum RAP1, and 6 of 8 cysteines were conserved in the rodent parasite orthologues. However the three polypeptides vary significantly in size. P. c. adami RAP1 and P. berghei RAP1 consist of 691 aa and 604 aa respectively, whereas P. falciparum RAP1 consists of 783 aa residues. These size differences reflect very different N-terminal sequences prior to the first cysteine, whereas the cysteine-rich C-terminal regions are more conserved. Both P. falciparum RAP1 and P. c. adami RAP1 contain N-terminal repeats, however they bear no sequence similarity to each other. P. berghei RAP1 lacks N-terminal sequence repeats that are characteristic of P. falciparum and P. c. adami RAP1. The large cysteine-rich C-terminal region P. c. adami RAP1 (PcRAP1 C3) was expressed in E. coli as a hexa-his fusion protein. Rabbit antiserum to recombinant PcRAP1 C3 was used to characterise the expression and sub-cellular localisation of the RAP1 antigen. P. c. adami RAP1 was found to have a Mr of approximately 80,000 and was shown by immunofluorescence to localise to the merozoite rhoptries. Passive immunisation of mice with rabbit anti-RAP1 serum was shown to protect against fulminant parasitaemia and mortality. In a mouse vaccination trial using the recombinant PcRAP1 C3 polypeptide partial protection was conferred against homologous parasite challenge
Evangelia Matthaei Lucae et Iohannis Itemque Acta Apostolica
Aus dem Griech. übers.Vorlageform des Erscheinungsvermerks: Berolini, Apvd Sigismvndvm Fridericvm Hessivm, A. C. MDCCLXXXI. - Kolophon: Vitebergae, Typis Adami Christiani Charisii
GLOBUS: C. Adami's Erdglobus / neu bearbeitet unt gezeichnet von H. Kiepert ; Stich v. J. Sulzer ; Druck v. L. Kraatz
1 Globus, col. L'empresa D. Reimer de Berlin neix el 1845 i el 1852 absorbeix la firma C. Adami especialitzada en geografia i construcció de globus. - Guix sobre peu de metall amb arc de meridià de metall, 60 cm amb el peu1:40 000 00034 cm de diàmetr
In divi Maximiliani imperatoris laudem et praeconium
Mit ZierinitialenSignaturen: A-C⁴, D⁶Impressum aus Kolophon: "Excussum est Basileae diligenti accuratissimaque cura providi viri Adami Petri ex Langendorff, atque ab ipso auctore diligenter revisum. Sub annum domini. M.D.XV.
- …
