Distribution and systematics of the freshwater genus Sirodotia (Batrachospermales, Rhodophyta) in North America

Multivariate morphometrics and image analysis were used to determine the number of well-delineated infrageneric taxa of Sirodotia in North America. Three groupings were distinguished from 25 populations examined from Newfoundland and Quebec in the north to central Mexico in the south. These groupings were statistically related to 10 type specimens, and the following species were recognized: Sirodotia huillensis (Welwitsch ex W. et G. S. West) Skuja (syn. S. ateleia Skuja), S. suecica Kylin (syn. S. acuminata Skuja ex Flint and S. fennica Skuja), and S. tenuissima (Collins) Skuja ex Flint. These species are differentiated on the basis of whorl shape and degree of separation at maturity (S. suecica, rounded and appressed; S. huillensis and S. tenuissima, truncated apex and separated), the density of spermatangia (S. huillensis, dense clusters, S. suecica and S. tenuissima, sparsely aggregated), and the mode of germination of the gonimoblast initial (S. suecica and S. tenuissima,from the nonprotuberant side of the fertilized carpogonium; S. huillensis from the protuberant side). Sirodotia huillensis was found only in the desert-chaparral, whereas S. suecica and S. tenuissima occurred from south-temperate to boreal regions in cool (temperature 8-18-degrees-C), low ion (specific conductance 10-99 muS.cm-1), and mildly acidic to neutral (pH 5.7-7.3) waters.

Alocação diferencial do 13C em Copaifera langsdorffii Desf. (Fabaceae - Caesalpinoideae) sob deficiência hídrica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anatomia de espécies brasileiras de Eriocaulaceae: Comanthera e Syngonanthus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inclusão das representações de gary e de skilling-umoto em modelos de linhas de transmissão trifásicas: Aplicação em simulações de transitórios eletromagnéticos em sistemas de energia elétrica

Pós-graduação em Engenharia Elétrica - FEIS

Influência do glyphosate no perfil bioquímico e fisiológico de populações de azevém (Lolium multiflorum) suscetíveis e resistentes ao herbicida

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sensitivity of yellow passion fruit plants to ultraviolet-B radiation

The objective of this work was to evaluate the effects of UV-B radiation on the vegetative growth and on the gas exchange characteristics of passion fruit plants (Passiflora edulis) grown in greenhouse. The average unweighted UV-B radiation near the apex of the plants was 8 W m-2 for the UV-B treatment (high UV-B), and 0.8 W m-2 for the control plants (low UV-B). Plants were irradiated with UV-B for 7 hours per day, centered on solar noon, during 16 days. High UV-B radiation resulted in lower shoot dry matter accumulation per plant. The content of UV-B absorbing compounds and anthocyanins was increased in the plants exposed to high UV-B radiation, when compared with the control. UV-B radiation did not affect stomatal conductance or transpiration rate, but reduced photosynthesis and instantaneous water‑use efficiency, and increased intercellular CO2 concentration. The accumulation of UV-B-absorbing compounds and anthocyanins did not effectively shield plants from supplementary UV-B radiation, since the growth and photosynthetic processes were significantly reduced.

Interferência Fano antissimétrica assistida por um férmion de Majorana

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

Efeitos das correlações inter-átomos adsorvidos na densidade de estados do grafeno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)