Morphology and anatomy of inflorescence and inflorescence axis in Paepalanthus sect. Diphyomene Ruhland (Eriocaulaceae, Poales) and its taxonomic implications

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Anatomical aspects of the gynoecium of species of Anthurium sect. Urospadix Engl. (Araceae, Alismatales)

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

Morphology of trichomes in Tibouchina sect. Pleroma (D-Don) Cogn. (Melastomataceae)

The Melastomataceae display greater trichome diversity. Dr. Wurdack, in his Atlas of hairs, recognized 46 types of trichomes for the Neotropical Melastomataceae through the Scanning Electron Microscope (SEM), and referred 17 of them to the genus Tibouchina. The trichome morphology has been extensively used in the delimitation of the taxa in Melastomataceae, as well as in previous studies by Cogniaux, the monograph of Brazilian Melastomataceae published in 1885. The morphology of the trichomes was essential for the delimitation of several species in Tibouchina section Pleroma. The use of SEM provided the best characterization of the 15 different types of trichomes recognized among the 41 species examined. These were described based on the morphological appearance, both optical microscopy and scanning electron microscopy, and illustrated by scanning electron micrographs and photomicrographs.

Morfologia dos tricomas em Tibouchina sect. Pleroma (D. Don) cogn. (melastomataceae)

Melastomataceae é a família que apresenta a maior diversidade de tricomas. Dr. Wurdack em seu Atlas of hairs reconheceu 46 tipos de tricomas para as Melastomataceae neotropicais com o uso de MEV, e referiu 17 destes para o gênero Tibouchina. em Melastomataceae a morfologia dos tricomas tem sido extensivamente usada na delimitação dos táxons, assim como em estudos que antecederam ao trabalho de Cogniaux, a monografia das Melastomataceae brasileiras publicada em 1885. em Tibouchina sect. Pleroma a morfologia dos tricomas foi substancial para a circunscrição de várias espécies. O uso da MEV permitiu uma caracterização dos 15 tipos diferentes de tricomas observados nas 41 espécies examinadas. Os diferentes tipos são descritos com base no aspecto morfológico tanto em MO como em MEV e ilustrados através de eletromicrografias de varredura e fotomicrografias.

Anatomia de escapos, folhas e brácteas de Syngonanthus sect. Eulepis (Bong. ex Koern.) Ruhland (Eriocaulaceae)

Estudou-se a anatomia de escapos, folhas e brácteas de 24 espécimes de Syngonanthus sect. Eulepis, que ocorrem nos campos rupestres do Brasil. Os escapos apresentam número variado de costelas, epiderme unisseriada, com células de paredes totalmente espessadas; córtex com esclerênquima e parênquima clorofiliano alternados; endoderme contínua ou descontínua; periciclo estrelado; feixes vasculares colaterais; medula com células de paredes finas ou espessadas. As folhas e as brácteas apresentam epiderme com células de paredes total ou parcialmente espessadas, estômatos na face abaxial, margem com parênquima clorofiliano ou esclerênquima; mesofilo com hipoderme constituída de esclerênquima ou parênquima aqüífero, feixes vasculares colaterais envolvidos externamente pela endoderme e internamente pelo periciclo. Escapos, folhas e brácteas de Syngonanthus sect. Eulepis apresentam células com paredes espessadas e grande quantidade de esclerênquima, provavelmente como resposta adaptativa dessas plantas ao vento e à radiação excessiva comum nos campos rupestres. Epiderme com células de paredes espessadas, estômatos com câmara subestomática não especializada, presença de hipoderme, esclerênquima, e parênquima clorofiliano compacto, caracterizam anatomicamente escapos, folhas e brácteas de Syngonanthus sect. Eulepis. No geral, os caracteres anatômicos não são consistentes para separar os táxons dentro da seção.

Embryology and seed development of Paepalanthus sect. Actinocephalus (Koern.) Ruhland (Eriocaulaceae)

The embryology and seed structure of Paepalanthus sect. Actinocephalus species were studied. The embryological and structural seed characters fit well with those of the other commelinaceous families. Within the Commelinales sensu Dahlgren, Eriocaulaceae and Xyridaceae represent two embryologically close families. In Paepalanthus sect. Actinocephalus the ovule is orthotropus, bitegmic, and tenuicellate with a micropyle formed by the inner integument. The seeds are endotestal. The outer cell layer of the testa and the outer periclinal wall of the endotesta disintegrate during development. The endotegmen is tanniniferous. The outer layer of the tegmen becomes compressed and is no longer recognizable in the mature seed. The seeds are operculate.

Anatomy of scapes, bracts, and leaves of Paepalanthus sect. Diphyomene (Eriocaulaceae, Poales) and its taxonomic implications

Paepalanthus sect. Diphyomene comprises 18 species with a convoluted taxonomic history. Aiming to correlate anatomical structures with the systematics of this group and its relatives, we studied the anatomy of scapes, reproductive axis bracts, and leaves of 20 Paepalanthus species. Bracts and leaves show differences in epidermal cell thickening; mesophyll width; vascular bundle arrangement; presence or absence of a hypodermis; types of cells in the vascular bundle sheath extensions; margin shape and composition; and presence or absence of aquiferous parenchyma. Scapes differ in contour, rib number, and pith size. Some diagnostic characters found are presence of aquiferous parenchyma and absence of vascular bundle sheath extensions in leaves of P. urbanianus; vascular bundles decreasing in size towards the margin of leaves and bracts, and scapes with a triangular contour in P. flaccidus; scapes with nine ribs in P. acanthophyllus and ten in P. macer. All anatomical features are summarized in tables. These results aid in the identification and characterization of the species of P. sect. Diphyomene. They also support the current section circumscription, reinforcing the relevance of the anatomical characters in order to define natural groups. © 2012 The New York Botanical Garden.

Seed morphology of bladderworts: a survey on Utricularia sect. Foliosa and sect. Psyllosperma (Lentibulariaceae) with taxonomic implications

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Anatomia de folhas, brácteas e escapos de Paepalanthus Sect. Diphyomene Ruhland (Eriocaulaceae, Poales)

As Eriocaulaceae brasileiras encontram-se distribuídas principalmente nos campos rupestres que se estendem de Minas Gerais à Bahia, na Cadeia do Espinhaço. Paepalanthus Mart. é o maior gênero da família e apresenta cerca de 450 espécies, sendo que Paepalanthus sect. Diphyomene Ruhl. possui cerca de 20 espécies que já pertenceram a diversas categorias taxonômicas. Com o objetivo de correlacionar a anatomia e a taxonomia desta seção, além de levantar caracteres diagnósticos para suas espécies, foi estudada a anatomia de folhas, brácteas e escapos. Folhas e brácteas de Paepalanthus sect. Diphyomene apresentam diferenças na forma e no espessamento das células epidérmicas; no espessamento do mesofilo; na disposição dos feixes vasculares; presença ou ausência de hipoderme; diferente forma e composição de parede das células da extensão de bainha do feixe vascular; forma e constituição da margem e presença ou ausência de parênquima aqüífero na face adaxial. No escapo, foram observadas diferenças quanto ao número e contorno de costelas e extensão da medula. Assim, a proposta de divisão de P. sect. Diphyomene em duas categorias é corroborada. São caracteres diagnósticos para as espécies: presença de parênquima aquífero na face adaxial e ausência de extensão de bainha do feixe vascular em folhas de Paepalanthus urbanianus; presença de feixes vasculares distribuídos em ordem decrescente de tamanho em direção à margem em folhas e brácteas e contorno triangular do escapo em P. flaccidus, presença de nove costelas em escapos de P. acanthophyllus e dez em P. macer. Foi elaborada uma chave de identificação das espécies de Paepalanthus sect. Diphyomene com base nas características anatômicas levantadas

Anatomia floral de espécies de Bulbophyllum sect. Micranthae (Orchidaceae, Asparagales)

Bulbophyllum, which comprises 1876 species, is considered the second largest genus of angiosperms, with a pantropical distribution. The morphological and anatomical floral studies in the genus are incipient, with data restricted to the gynostemium and lip of some species. Based on molecular data, six sections were recognized within Bulbophyllum at the Neotropics, amongst them Bulbophyllum sect. Micranthae, which comprises 12 species distributed in central South America. We aimed to study the floral anatomy of six species of Bulbophyllum sect. Micranthae, in order to determine useful characters to differentiate them and contribute to the anatomical characterization of the section as a whole. Floral anatomy was assessed through usual techniques of light microscopy. The data found here for B. adiamantinum, B. chloroglossum, B. epiphytum, B. mentosum, B. micranthum and B. rupicolum allowed to identificate the presence of glandular trichomes and the possible presence of a secretory region on the lip, which might produce substances used as a reward to pollinators. The most significant anatomical characters to the species characterization were the shape and ornamentation of the outer periclinal walls of the epidermal cells, as well as the number of vascular bundles in dorsal and lateral sepals and at the lip. The data also allowed the differentiation between B. epiphytum and B. rupicolum, species very similar in morphology and phylogenetically related. Besides that, the data also allowed the discussion regarding the maintenance of B. mentosum within the section: although its inclusion is supported by molecular studies, the anatomical data here presented shows greater differences compared to the other species, not supporting its maintenance in Bulbophyllum sect. Micranthae

Purificação, imobilização e caracterização bioquímica de lipase produzida por Penicillium sect. Gracilenta CBMAI 1583 em cultivo submerso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

Electrically, Chemically, and Photonically Powered Torsional and Tensile Actuation of Hybrid Carbon Nanotube Yarn Muscles

Artificial muscles are of practical interest, but few types have been commercially exploited. Typical problems include slow response, low strain and force generation, short cycle life, use of electrolytes, and low energy efficiency. We have designed guest-filled, twist-spun carbon nanotube yarns as electrolyte-free muscles that provide fast, high-force, large-stroke torsional and tensile actuation. More than a million torsional and tensile actuation cycles are demonstrated, wherein a muscle spins a rotor at an average 11,500 revolutions/minute or delivers 3% tensile contraction at 1200 cycles/minute. Electrical, chemical, or photonic excitation of hybrid yarns changes guest dimensions and generates torsional rotation and contraction of the yarn host. Demonstrations include torsional motors, contractile muscles, and sensors that capture the energy of the sensing process to mechanically actuate.

Polyaniline mixed LB films exposed to X-rays

X-ray irradiation is shown to affect electronic properties of polyaniline (PANi) in composite Langmuir-Blodgett (LB) films of PANi and cadmium stearate, in a similar way to acid doping. The time it takes for the shift in the UV-vis spectra, characteristic of PANi doping, increases linearly with the film thickness, thus indicating a surface-controlled process. The humidity of the environment under which the films are irradiated is also of extreme importance. No shin is observed under vacuum or under dry atmospheres of N-2, O-2 and Ar. For humid environments the time for the shift decreases with increasing relative humidity.