Ecology and morphological characterization of gametophyte and 'Chantransia' stages of Sirodotia huillensis (Batrachospermales, Rhodophyta) from a stream in central Mexico

The morphology and phenology of Sirodotia huillensis was evaluated seasonally in a central Mexican first-order calcareous stream. Water temperature was constant (24-25°C) and pH circumneutral to alkaline (6.7-7.9), and calcium and sulfates were the dominant ions. The gametophyte stages were characterized by the presence of a distinctive mucilaginous layer, a marked difference in phycocyanin to phycoerythrin ratio between female and male plants, and the presence of a carpogonia with a large trichogyne (>60 μm). Occasionally three capogonia were observed on a single basal cell. The 'Chantransia' stages were morphologically similar to those described for the other members of Batrachospermales. A remarkable observation was the formation of dome-shaped structures, consisting of prostrate filaments that are related with the development of new gametophytes. Chromosome numbers were n = 4 for fascicle cells, cortical filament cells and dome-shaped cells, and 2n = 8 for gonimoblast filament cells and 'Chantransia' stage filaments. Gametophytes and 'Chantransia' stages occurred in fast current velocities (60-170 cm/s) and shaded (33.1-121 μmol photons/m2/s) stream segments. The population fluctuated throughout the study period in terms of percentage cover and frequency: the 'Chantransia' stages were most abundant in the rainy season, whereas gametophytic plants had the highest frequency values during the dry season. These results were most likely a result of fluctuations in rainfall and related changes in current velocity. Some characteristics of this population can be viewed as probable adaptations to high current velocities: the mucilaginous layer around plants that reduces drag; potential increase in fertilization by the elongate and plentiful trichogynes and abundant dome-shaped structures producing several gametophytes.

Anti-platelet activity of infusion of Tithonia diversifolia's leaves

Tithonia diversifolia, also known as Mexican arnica, has been used in traditional medicine to treat inflammatory refractory with absence of citotoxicity. The possible health risks associated with the consumption of ingestion of the infusion (tea) plant makes it is necessary to identify the potential pharmacological activity or toxicity to prove certain plants that are acclimated in Brazil. Considering the limited number of pharmacological studies regarding the Tithonia diversifolia, the aim of this study was evaluate the effects of this infusion in platelet aggregation. Venous blood was collected with informed consent from healthy volunteers who denied taking any medication in the previous 14 days. Whole blood was transferred into polypropylene tubes containing one-tenth of final volume of acid citrate dextrose (ACD-C; citric acid 3%, trisodium citrate 4%, glucose 2%; 1:9 v/v) and centrifuged at 200g for 15 min. Platelet rich plasma was added of wash buffer solution (NaCl 140mM, KCl 5mM, sodium citrate 12mM, glucose 10mM and saccharose 12mM; pH 6; 5:7 v/v) and centrifuged at 800g for 12 min at 20°C. Platelet pellet was gently resuspended in Krebs-Ringer solution and counts were performed on a Neubauer chamber. Aggregation assay was carried out with 400 μL of platelet suspension (1.2x10 8 platelets/mL) in a cuvette at 37°C with constant stirring. Platelet suspension was incubated for 3 min with aqueous extract infusion (0.6-20μg/mL) prior to addition of thrombin (100 mU/mL). Percentage of platelet aggregation was recorded with an aggregometer (Chrono-log Lumi-Aggregometer model 560-Ca, USA). Our results show an inhibition of thrombin induced platelet aggregation in the presence of 0.6-20 ug/mL Tithonia diversifolia infusion leaves. The Tithonia diversifolia infusion leaves inhibits thrombin induced washed platelet aggregation.

New isoniazid complexes, promising agents against mycobacterium tuberculosis

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

Fraseologismos zoônimos: elaboração de base de dados Português-Francês

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

Os provérbios relativos aos Sete Pecados Capitais

Pós-graduação em Estudos Linguísticos - IBILCE

As estratégias de inserção na Economia internacional do Brasil e do México: o Mercosul, o Nafta e a política externa

Pós-graduação em Ciências Sociais - FFC

Avaliação microbiológica e sensorial do guacamole conservado pelo frio: Juliana Wagner Simon. -

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

A modernidade no ensaísmo político de Octávio Paz

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Os mexicas em época de conquista: enunciações de sua alteridade pelos espanhóis e tezcocanos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Operários e camponeses: a repercussão da Revolução Mexicana na imprensa operária brasileira (1910-1920)

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

Recursos de presença nas crônicas de Millôr Fernandes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O pensamento de Alberto Torres e Andrés Molina Enriquez e a constituição da organização nacional no Brasil e no México: diagnósticos e tratamentos para duas sociedades enfermas

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

Modelo linguístico-computacional para um dicionário analógico digital

Pós-graduação em Linguística e Língua Portuguesa - FCLAR

A formação inicial de professoras de línguas para/em contexto mediado pelo computador (teletandem): um diálogo entre crenças, discurso e reflexão profissional

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