Homomorphic Sex Chromosomes and the Intriguing Y Chromosome of Ctenomys Rodent Species (Rodentia, Ctenomyidae)

Unlike the X chromosome, the mammalian Y chromosome undergoes evolutionary decay resulting in small size. This sex chromosomal heteromorphism, observed in most species of the fossorial rodent Ctenomys, contrasts with the medium-sized, homomorphic acrocentric sex chromosomes of closely related C. maulinus and C. sp. To characterize the sequence composition of these chromosomes, fluorescent banding, self-genomic in situ hybridization, and fluorescent in situ hybridization with an X painting probe were performed on mitotic and meiotic plates. High molecular homology between the sex chromosomes was detected on mitotic material as well as on meiotic plates immunodetected with anti-SYCP3 and anti-gamma H2AX. The Y chromosome is euchromatic, poor in repetitive sequences and differs from the X by the loss of a block of pericentromeric chromatin. Inferred from the G-banding pattern, an inversion and the concomitant prevention of recombination in a large asynaptic region seems to be crucial for meiotic X chromosome inactivation. These peculiar findings together with the homomorphism of Ctenomys sex chromosomes are discussed in the light of the regular purge that counteracts Muller's ratchet and the probable mechanisms accounting for their origin and molecular homology. (C) 2014 S. Karger AG, Basel

Single Origin of Sex Chromosomes and Multiple Origins of B Chromosomes in Fish Genus Characidium

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cenografia teatral: uma análise dos aspectos cênicos da peça Bê-a-Bá Brasil - memória, sonho e fantasia

The main objective of this project step is the evolution of scenery matter on the occidental theater media, related to space and technical possibilities of the theatrical building and space on history of contemporary arts. The main point is that scenery must communicate with a specific matter. Something in touch with the plot speeches. Something that makes all the plot elements to communicate. Acting has an specific message to deliver, and that message is what really matter to the viewer of the show. “It’s never late to state that scenery is not a decoration, or just an interior composition. Scenery is not a painting or a sculpture: it’s an integrated art form. It’s never too repetitive to say that scenery is a result from the composition with lights, shadows, shapes, lines and volumes, in balance and on harmony as a whole, that create movement and contrast” (Dias, 2001) On the second step of the project, the objective is to analyze the building process and the scenery aspects of the “Be-a-bá Brasil” show, using illustrations, pictures and analysis data of the context the show was inserted on

A flexible lab-on-a-chip for the synthesis and magnetic separation of magnetite decorated with gold nanoparticles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Color stability of the artificial iris button in an ocular prosthesis before and after acrylic resin polymerization

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Repetitive DNA sequences and evolution of ZZ/ZW sex chromosomes in characidium (teleostei: characiformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Review of The Elemental Prairie: Sixty Tallgrass Plants (Watercolors and introduction) by George Olson

The Elemental Prairie provides a general discussion of the Great Plains and the tallgrass prairie for the general reader. Its botanically accurate plant drawings render a beautiful and artistic view into prairie plants. George Olson writes a compelling introduction about "Prairie Elements," painting a graphic verbal description about his trip into the prairie with noted prairie author John Madson. The introduction draws readers into the book and prepares them for John Madson's essay "The Running Country," an eloquent portrayal of the history of the tallgrass prairie. We are led into the hearts and minds of the pioneers who crossed the immense expanse of the Great Plains. Madson's descriptions of prairie plants help us visualize how the Great Plains looked prior to settlement, stirring us to see not only the allure of the prairies, but also the solitude and sometimes the loneliness. Madson mixes his personal experiences with current scientific theory of the formation of the prairies across the region, offering a way of seeing how the present fits into the past.

Variable patterns of Y chromosome homology in Akodontini rodents (Sigmodontinae): a phylogenetic signal revealed by chromosome painting

The Akodontini is the second most speciose tribe of sigmodontine rodents, one of the most diverse groups of neotropical mammals. Molecular phylogenetic analyses are discordant regarding the interrelationships of genera, with low support for some clades. However, two clades are concordant, one (clade A) with Akodon sensu strictu (excluding Akodon serrensis), "Akodon" serrensis, Bibimys, Deltamys, Juscelinomys, Necromys, Oxymycterus, Podoxymys, Thalpomys and Thaptomys, and another (clade B) with Blarinomys, Brucepattersonius, Kunsia, Lenoxus and Scapteromys. Here, we present chromosome painting using Akodon paranaensis (APA) Y paint, after suppression of simple repetitive sequences, on ten Akodontini genera. Partial Y chromosome homology, in addition to the homology already reported on the Akodon genus, was detected on the Y chromosomes of "A." serrensis, Thaptomys, Deltamys, Necromys and Thalpomys and on Y and X chromosomes in Oxymycterus. In Blarinomys, Brucepattersonius, Scapteromys and Kunsia, no APA Y signal was observed using different hybridization conditions; APA X paint gave positive signals only on the X chromosome in all genera. The Y chromosome homology was variable in size and positioning among the species studied as follow: (1) whole acrocentric Y chromosome in Akodon and "A." serrensis, (2) Yp and pericentromeric region in submetacentric Y of Necromys and Thaptomys, (3) pericentromeric region in acrocentric Y of Deltamys, (4) distal Yq in the acrocentric Y chromosome of Thalpomys and (5) proximal Yq in the acrocentric Y and Xp in the basal clade A genus Oxymycterus. The results suggest that the homology involves pairing (pseudoautosomal) and additional regions that have undergone rearrangement during divergence. The widespread Y homology represents a phylogenetic signal in Akodontini that provides additional evidence supporting the monophyly of clade A. The findings also raise questions about the evolution of the pseudoautosomal region observed in Oxymycterus. The Y chromosomes of these closely related species seem to have undergone dynamic rearrangements, including restructuring and reduction of homologous segments. Furthermore, the changes observed may indicate progressive attrition of the Y chromosome in more distantly related species.

Influence of artificial accelerated ageing on the colour stability of paints used for ocular prosthesis iris painting

Objectives: To evaluate the colour stability of paints used for ocular prosthesis iris painting submitted for accelerated artificial ageing (AAA). Materials and methods: Forty specimens of acrylic resin for sclera (16 x 2 mm) were made and separated into eight groups (n = 10) according to the type of paint (gouache, GP; oil, OP; acrylic AP; and composite resin for characterisation, CR) and the colours used (blue/brown). After drying (72 h), a new layer of colourless acrylic resin was applied and the initial colour readout was performed (Spectrophotometer PCB 6807). New colour readouts were performed after AAA, and Delta E was calculated. Results: Statistical analysis (two-way ANOVA-Bonferroni, p < 0.05) demonstrated that the brown colour showed lower Delta E means in comparison with the blue colour, with statistically significant difference for AP only. Blue colour showed no statistically significant difference with regard to the type of paint used. Brown AP showed lower Delta E than the other groups, with significant difference for OP and GP. GP showed greater alteration in Delta E for the brown colour, being statistically similar only to OP. Conclusions: Only the AP group for brown pigment shows clinically acceptable values for colour stability after AAA.

Pierre-Auguste Renoir (1841-1919) and rheumatoid arthritis

Pierre-Auguste Renoir (1841-1919), one of the world's most celebrated impressionist painters, suffered from rheumatoid arthritis for most of his life. His symptoms developed when he was in his 50s and they became aggressive at about the age of 60 years that led to almost complete disability when he was 70 years old. Although the deformities he suffered because of the rheumatoid arthritis were disabling, Renoir never stopped painting nor decreased the quality of his work. The transition between styles adopted by the painter (Impressionist, Dry and Pearly periods) bear no relationship to the stages of flare-ups or the establishment of joint deformities due to rheumatoid arthritis. His work shows aspects of the body's ability to overcome pain and physical limitation.

Phylogeographic Structure and Karyotypic Diversity of the Brazilian Shrew Mouse (Blarinomys breviceps, Sigmodontinae) in the Atlantic Forest

Blarinomys breviceps possesses cryptic and burrowing habits with poorly documented genetics and life history traits. Due to its rarity, only a few specimens and DNA sequences have been deposited in collections worldwide. Here, we present the most comprehensive cytogenetic and molecular characterization of this rare genus. Phylogenetic analyses based on partial cytochrome b sequences were performed, attempting to establish the relationships among individuals with distinct karyotypes along the geographic distribution of the genus in the Atlantic Forest. Classical and molecular cytogenetics, using banding patterns and FISH of telomeric and whole chromosome X-specific painting probes (obtained from the Akodontini Akodon cursor) were used to characterize and compare the chromosomal complements. Molecular phylogenetic analyses recovered 2 main geographically structured clades, northeastern and southeastern with pair-wise sequence divergences among specimens varying between 4.9 and 8.4%. Eight distinct karyomorphs are described: (A) 2n = 52 (50A, XX), (B) 2n = 52 (48A, XY+2Bs), (C) 2n = 45 (42A, XY+1B), (D) 2n = 43 (37A, XX+4Bs), (E) 2n = 37 (34A, XY+1B), (F) 2n = 34 (32A, XX), (G) 2n = 31 (27A, XX+2Bs), (H) 2n = 28 (26A, XY), all with the same number of autosomal arms (FNA = 50). Variation of 0-4 supernumerary chromosomes (Bs) presenting heterogeneity in morphology and distribution of interstitial telomeric sequences (ITSs) is reported. ITSs are also found in some metacentric autosomes. The phylogeographic separation between 2 major lineages with high levels of genetic divergence, and the wide karyotypic diversity indicate that B. breviceps is a diverse group that warrants taxonomic re-evaluation. Copyright (C) 2012 S. Karger AG, Basel

Core-shell macromolecules with dendritic polyphenylene core and polymer shells

Core-shell macromolecules with dendritic polyphenylene core and polymer shell Zusammenfassung / Abstract Core-shell macromolecular structures have become of great interest in materials science because they gave an opportunity to combine a large variety of chemical and physical properties in the single molecule, by combination of different (in terms of chemistry and physics) cores and shells. The interest in such complex structures was provoked by their potential applications in the coating and painting industry (latexes), as supports for catalysts in polymer industry, or as nano-containers and transporters for genes or drug delivery. The aim of this study was the synthesis, characterization and further application of core-shell macromolecules possessing a hydrophobic stiff core (polyphenylene dendrimers) surrounded with a hydrophilic, soft, covalently bonded polymer shell (poly(ethylene oxide) and its copolymers). The requirements for such complex substances were that they should be well-defined in terms of molecular weight (narrow molecular weight distribution) and in molecular structure. The preparation of core-shell molecules containing dendrimer as a core was possible via two synthetic routs: “grafting-onto” and “grafting-from”. The resulting core-shell macromolecules possessed narrow polydispersity as guaranteed by the excellent structural and functional definition of the dendrimer and the narrow polydispersity of the PEO, PS-b-PEO and PI-b-PEO attached to the dendrimer surface. Additional investigation of the size of the particles indicated a relation between both the length and the number of the polymer chains and the hydrodynamic radius determined by Dynamic Light Scattering and Fluorescent Correlation Spectroscopy. Core-shell nano-particles were applied as metallocene supports in heterogeneous olefin polymerizations. Our results indicate that such catalyst systems, that have a size of at least one order of magnitude smaller than the used by now organic supports, could be very useful as model compounds for investigations on catalyst fragmentation and its influence on the product parameters.

Multicomponent nanodevices based on molecular and nanocrystal moieties

Nanoscience is an emerging and fast-growing field of science with the aim of manipulating nanometric objects with dimension below 100 nm. Top down approach is currently used to build these type of architectures (e.g microchips). The miniaturization process cannot proceed indefinitely due to physical and technical limitations. Those limits are focusing the interest on the bottom-up approach and construction of nano-objects starting from “nano-bricks” like atoms, molecules or nanocrystals. Unlike atoms, molecules can be “fully programmable” and represent the best choice to build up nanostructures. In the past twenty years many examples of functional nano-devices able to perform simple actions have been reported. Nanocrystals which are often considered simply nanostructured materials, can be active part in the development of those nano-devices, in combination with functional molecules. The object of this dissertation is the photophysical and photochemical investigation of nano-objects bearing molecules and semiconductor nanocrystals (QDs) as components. The first part focuses on the characterization of a bistable rotaxane. This study, in collaboration with the group of Prof. J.F. Stoddart (Northwestern University, Evanston, Illinois, USA) who made the synthesis of the compounds, shows the ability of this artificial machine to operate as bistable molecular-level memory under kinetic control. The second part concerns the study of the surface properties of luminescent semiconductor nanocrystals (QDs) and in particular the effect of acid and base on the spectroscopical properties of those nanoparticles. In this section is also reported the work carried out in the laboratory of Prof H. Mattoussi (Florida State University, Tallahassee, Florida, USA), where I developed a novel method for the surface decoration of QDs with lipoic acid-based ligands involving the photoreduction of the di-thiolane moiety.

Identity formation at the beginning of the twenty-first century: Intersubjectivity, art, and medicine in Siri Hustvedt’s works

„Ich bin, weil du bist“ – so lautet eines der Schlüsselzitate in What I Loved, dem 2003 erschienenen dritten Roman der zeitgenössischen amerikanischen Autorin Siri Hustvedt. Die Bedeutung von Beziehung und Interaktion für die Identitätsbildung spielt eine zentrale Rolle nicht nur in diesem Roman, sondern auch in ihrem Gesamtwerk, das vier Romane, ein memoir, drei Essay-Sammlungen und einen Lyrikband umfasst. Hustvedt erforscht die Identität als ein vielschichtiges Produkt bewusster und unbewusster Verknüpfungen innerhalb der sozialen und biologischen Umwelt. Das Bewusstsein wird als eine dialogisch geprägte Entität gezeigt, dessen Identität erst durch die Beziehung auf ein Anderes geformt werden kann. Um dem Mysterium der menschlichen Identitätsfindung nachzuspüren, bedient sich Hustvedt sowohl philosophischer, psychoanalytischer, biologischer als auch kunsttheoretischer Diskurse. In ihren Romanen stellt sich die Frage nach der Erklärung von Identität als komplexe Problematik dar: Ist die Beziehung zu anderen Menschen vor allem durch unsere Entwicklung als Kind und die Nähe zu Bezugspersonen geprägt? In welchem Ausmaß ist das Empfinden von Subjektivität beeinflusst von körperlichen und unbewussten Mechanismen? Inwiefern ist die Wahrnehmung visueller Kunst eine Kooperation zwischen Betrachter und Künstler? rnDiesen und anderen Fragen geht diese Dissertation nach, indem sie Hustvedts Werk als Anlass für eine Analyse intersubjektiver Strukturen der Identität nimmt. Die Intersubjektivitätsphiloso¬phien von Hegel, Buber, Bakhtin, Husserl, und Merleau-Ponty dienen hierbei als Ausgangspunkt für die Interpretation von relationaler Identität in Hustvedts Werken. Die Dissertation konzentriert sich auf Hustvedts Darstellung der Beziehung zwischen Selbst und Anderem in der Photographie und in der Malerei, der Überschreitung von Körpergrenzen in Hysterie und Anorexie sowie der Auswirkung des Verlustes von Bezugspersonen auf die persönliche Identität. Entscheidend für den Hustvedtschen Kunstbegriff ist das Zusammenspiel von Kunstobjekt, Künstler und Betrachter. Die Grenzen zwischen Innerem und Äußeren werden aufgelöst: mal wird der Rezipient Teil des Kunstwerks, mal verschmilzt der Künstler förmlich mit seinem Objekt. Auch hier wird wiederum deutlich, dass Identität nur in Wechselbeziehung und als zwischenmenschliche Kooperation entsteht. Hustvedt betritt durch ihre einzigartige Auseinandersetzung mit den Wechselbeziehungen und fragilen Grenzen zwischen Ich und Umwelt Neuland auf dem Gebiet der literarischen Identitätsforschung, da sie ihr Prinzip des „mixing,“ des unausweichlichen Eindringens fremder Substanz in die eigene Identität, aus dem Blickwinkel dieser verschiedenen Erklärungsansätze beleuchtet. rn

Alpha, Omega end group functionalization of RAFT polymers based on pentafluorophenyl esters and methane thiosulfonates

While polymers with different functional groups along the backbone have intensively been investigated, there is still a challenge in orthogonal functionalization of the end groups. Such well-defined systems are interesting for the preparation of multiblock (co) polymers or polymer networks, for bio-conjugation or as model systems for examining the end group separation of isolated polymer chains. rnHere, Reversible Addition Fragmentation Chain Transfer (RAFT) polymerization was employed as method to investigate improved techniques for an a, w end group functionalization. RAFT produces polymers terminated in an R group and a dithioester-Z group, where R and Z stem from a suitable chain transfer agent (CTA). rnFor alpha end group functionalization, a CTA with an activated pentafluorophenyl (PFP) ester R group was designed and used for the polymerization of various methacrylate monomers, N-isopropylacrylamide and styrene yielding polymers with a PFP ester as a end group. This allowed the introduction of inert propyl amides, of light responsive diazo compounds, of the dyes NBD, Texas Red, or Oregon Green, of the hormone thyroxin and allowed the formation of multiblocks or peptide conjugates. rnFor w end group functionalization, problems of other techniques were overcome through an aminolysis of the dithioester in the presence of a functional methane thiosulfonate (MTS), yielding functional disulfides. These disulfides were stable under ambient conditions and could be cleaved on demand. Using MTS chemistry, terminal methyl disulfides (enabling self-assembly on planar gold surfaces and ligand substitution on gold and semiconductor nanoparticles), butynyl disulfide end groups (allowing the “clicking” of the polymers onto azide functionalized surfaces and the selective removal through reduction), the bio-target biotin, and the fluorescent dye Texas Red were introduced into polymers. rnThe alpha PFP amidation could be performed under mild conditions, without substantial loss of DTE. This way, a step-wise synthesis produced polymers with two functional end groups in very high yields. rnAs examples, polymers with an anchor group for both gold nanoparticles (AuNP) and CdSe / ZnS semi-conductor nanoparticles (QD) and with a fluorescent dye end group were synthesized. They allowed a NP decoration and enabled an energy transfer from QD to dye or from dye to AuNP. Water-soluble polymers were prepared with two different bio-target end groups, each capable of selectively recognizing and binding a certain protein. The immobilization of protein-polymer-protein layers on planar gold surfaces was monitored by surface plasmon resonance.Introducing two different fluorescent dye end groups enabled an energy transfer between the end groups of isolated polymer chains and created the possibility to monitor the behavior of single polymer chains during a chain collapse. rnThe versatility of the synthetic technique is very promising for applications beyond this work.