Blue-greenish acrochaetioid algae in freshwater habitats are Chantransia stages of Batrachospermales sensu lato (Rhodophyta)

Fourteen culture isolates of freshwater acrochaetioid algae from distinct regions around the world were analysed, including the reddish species Audouinella hermannii, the dubious blue-greenish species A. pygmaea, and Chantransia stages from distinct taxonomic origins in the Batrachospermales sensu lato (Batrachospermaceae, Lemaneaceae and Thoreaceae). Four isolates (two 'Chantransia' stages and two species of Audouinella, A. hermannii and A. pygmaea) were tested under experimental conditions of temperature (10-25°C), irradiance (65 and 300 μmol photons m-2 s-1) and photoperiod (16:8 h and 8:16 h light/dark cycles). Plant colour is proposed as the only vegetative character that can be unequivocally applied to distinguish Audouinella from 'Chantransia', blue-greenish representing Chantransia stages and reddish applying to true Audouinella species (also forming reproductive structures other than monosporangia, e.g. tetrasporangia). Some isolates of A. pygmaea were proven to be unequivocally 'Chantransia stages owing either to production of juvenile gametophytes or to derivation from carpospores. No association of the morphology of A. pygmaea was found with any particular species, thus it should be regarded as a complex involving many species of the Batrachospermales sensu lato, as is also the case with A. macrospora. We therefore recommend that all blue-greenish acrochaetioid algae in freshwater habitats be considered as Chantransia stages of members of the Batrachospermales, and that the informal descriptors pygmaea and macrospora be used to distinguish the two discernable morphologies. Induction of gametophytes occurred under much wider conditions than previously reported, reinforcing the conclusion that requirements are probably species-specific. Although phenotypic plasticity was in evidence, with temperature, irradiance and photoperiod affecting morphology, no alga showed variation outside the limits based on traditional taxonomic studies. No overall trend was observed for vegetative or reproductive characters in response to temperature, irradiance and photoperiod for all the algae tested, only for specific algae or characters. Effects of temperature and irradiance on morphological characters were more evident, as well as strong interactions between these variables, whereas few differences were generally found in response to photoperiod and irradiance.

Photoacclimation in three species of freshwater red algae

Three freshwater Rhodophyta species (Audouinella eugenea, A. hermannii and Compsopogon coeruleus) were tested as to their responses (photosynthesis, growth and pigment concentration) to two irradiances (low light, LL, 65 μmol m -2 s-1 and high light, HL, 300 μmol m-2 s-1) and two periods (short time, ST, 4 d, and long time, LT, 28 d). Higher growth rates were consistently observed at LL but significant differences were observed only for A. hermannii. Higher values of photoinhibition at LL were found for the three species, which is consistent with the dynamic photoinhibition as a reversible photoprotective mechanism against high irradiance. Light-induced decreases of effective quantum yield (EQY) were observed in the three species consisting of pronounced decreases from LL to HL. Rapid increases of non-photochemical quenching (NPQ) were observed mainly at LL, indicating energy dissipation by reaction centers. Results revealed distinct photoacclimation strategies to deal with high irradiances: the two Audouinella species had only characteristics of shade-adapted algae: acclimation by changes of size of photosy stem units (PSU) under LT and by PSU number under ST; higher values of the photoinhibition parameter (β) and NPQ, and lower values of EQY at LL; higher recovery capacity of potential quantum yield (PQY) at LL and under ST; highly significant positive correlation of electron transport rate (ETR) with NPQ. In addition, C. coeruleus mixed some characteristics of sun-adapted algae: acclimation by changes of PSU number under LT and by PSU size under ST; higher recovery capacity of EQY than the other two species; weak or no correlation of ETR with NPQ. Thus, these characteristics indicate that C. coeruleus cope with high irradiances more efficiently than the Audouinella species.

Calcareous algae from Upper Albian - Cenomanian strata of the Potiguar basin (NE Brazil)

Calcareous Albian-Cenomanian strata in the Potiguar basin yield a number of microfossils, among which are calcareous algae (Dasycladales and Corallinales). This data, together with an inventory of previous discoveries, enabled the discussion of their biogeography. These benthic organisms probably came from the early Central Atlantic Ocean through its northwestern neck between Africa and South America and thus reached the early South Atlantic platforms.

Reproductive biology of an endemic Physalaemus of the Brazilian Atlantic forest, and the trade-of between clutch and egg size in terrestrial breeders of the P. signifer group

Physalaemus crombiei is a small foam-nesting frog endemic to the Atlantic forest. It is a member of the P. signifer group known only from its type locality in Santa Teresa, State of Espírito Santo, and from another locality in the State of Bahia, Brazil. Most Physalaemus species are aquatic breeders, and species in the P. signifer group are the only ones exhibiting a tendency toward terrestrial reproduction in the genus. Here we describe the reproductive period, breeding site and reproductive modes of P. crombiei from a third population in the Atlantic forest, southeastern Brazil. We also investigated reproductive effort and size-fecundity relationships in females. Reproductive traits were compared to other species in the genus Physalaemus, especially those included in the P. signifer group. Physalaemus crombiei is a prolonged breeder, reproducing throughout the year with a peak of activity during the most rainy months (October-March). Males called from the humid forest foor and eggs embedded in foam nests were deposited in the water as well as on the humid foor amidst the leaf litter, or inside fallen leaves or tree holes containing rainwater on the forest foor. As expected, P. crombiei exhibited three alternative reproductive modes, as described for other species of the P. signifer group. The number of eggs produced per female varied from 91 to 250. Female body size is positively correlated both with ovary mass and clutch size (number of eggs per clutch). Variation in the number and size of eggs observed in Physalaemus species may be explained not only by female size, but also by the terrestrial reproductive mode exhibited by the species in the P. signifer group.

Artificial satellites: Resonance effects produced by terrestrial tide

Effects due to resonances in the orbital motion of artificial satellites disturbed by the terrestrial tide are analyzed. The nodal co-rotation resonance, apsidal co-rotation resonance and the Lidov-Kozai's mechanism are studied. The effects of the resonances are analyzed through the variations of the metric orbital elements. Libration and circulation motions for high orbits with high eccentricities are verified for the Lidov-Kozai's mechanism.

New records and distribution extensions of three species of Mesoclemmys Gray, 1863 (Testudines: Chelidae) in Mato Grosso state, Brazil, with observations on terrestrial movements

Distribution patterns of most of the 20 Neotropical freshwater turtles belonging to the family Chelidae are usually based on few locality records. We here report on vouchered records of three species of the chelid genus Mesoclemmys in the Brazilian state of Mato Grosso. Presence of M. vanderhaegei is confirmed for the Amazon River Basin, and M. gibba and M. raniceps are recorded in Mato Grosso for the first time. © 2012 Check List and Authors.

No changes in seedling recruitment when terrestrial mammals are excluded in a partially defaunated Atlantic rainforest

One of the most intriguing questions in ecology is how to identify which and how many species will be able to inhabit human-modified landscapes. Large-bodied mammals structure plant communities by trampling, herbivory, seed dispersal and predation, and their local extinction may have pervasive consequences in plant communities due to the breakdown of key interactions. Although much attention has been given to understanding the effects of defaunation on plant communities, information on the potential impacts on plant functional groups (seed dispersal, seed size and seedling leaves defense) inhabiting continuous forests after defaunation is scarce. We conducted mammal surveys (line transects and camera trapping) to determine the defaunation status of a continuous Atlantic forest in Brazil. Then, we evaluated the effects of defaunation on seedling diversity, richness and abundance of functional groups using 15 plot-pairs (each pair with one open and one exclusion plot) monitored over 36. months. We found that the studied area is partially defaunated because it exhibits high abundance of primates, while terrestrial mammals, such as large rodents and ungulates, are rare. We found no significant changes in either seedling richness and diversity or in the seedling composition of plant functional groups in response to mammal exclosure. Seedling mortality and recruitment were similar between plot types. Our findings suggest that at semi-defaunated areas, where arboreal species are still present, terrestrial mammals have low impacts on the plant community reassembly. © 2013 Elsevier Ltd.

Structure and dynamics of the community of periphytic algae in a subtropical reservoir (state of São Paulo, Brazil)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Indirect georeferencing of terrestrial laser scanning data using control lines

An indirect method for the georeferencing of 3D point clouds obtained with terrestrial laser scanning (TLS) data using control lines is presented. This technique could be used for rapid data acquisition where resources do not permit the use of expensive navigation sensors or the placement of pre-signalised targets. The most important characteristic is the development of a mathematical model based on the principle that the direction vector of the TLS straight line is coplanar with the plane defined by the origin of the TLS system, one endpoint of a control line and the direction vector of the control line in the ground reference coordinate system. The transformation parameters are estimated by minimising the distance between the control lines and their corresponding TLS straight lines. The proposed method was tested using both simulated and real data, and the advantages of this new approach are compared with conventional surveying methods. © 2013 This article is a U.S. Government work and is in the public domain in the USA.

Algas e cianobactérias aerofíticas de fragmentos de floresta estacional semidecidual no noroeste paulista

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Sulfated polysaccharide extracted of the green algae Caulerpa racemosa increase the enzymatic activity and paw edema induced by sPLA2 from Crotalus durissus terrificus venom

Sulfated polysaccharides derived from seaweed have shown great potential for use in the development of new drugs. In this study, we observed that a low-molecular-weight sulfated polysaccharide from Caulerpa racemosa, termed CrSP, could interact with secretory phospholipase A2 (sPLA2) isolated from Crotalus durissus terrificus venom. When native sPLA2 (14 kDa) was incubated with CrSP, they formed a molecular complex (sPLA2:CrSP) with a molecular mass of 32 kDa, approximately. Size exclusion chromatography experiments suggested that CrSP formed a stable complex with sPLA2. We belived that sPLA2 and SPCr are involved an ionic interaction between negatively charged CrSP and the positively charged basic amino acid residues of sPLA2, because this interaction induced significant changes in sPLA2 enzymatic and pharmacological activities. CrSP caused a significant increase in sPLA2 enzymatic and bactericidal activity and increased its edematogenic effect. A pharmacological assay showed that the myotoxic activity of sPLA2:CrSP is unrelated to its enzymatic activity and that sPLA2:CrSP may have a practical application as a natural antibacterial agent for use in humans and commercially raised animals.

Swimming performance in semiaquatic and terrestrial Oryzomyine rodents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphological aspects of the testes of 18 species of terrestrial of Heteroptera from Northwestern Sao Paulo (Brazil)

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

TERRESTRIAL PLANET FORMATION IN A PROTOPLANETARY DISK WITH A LOCAL MASS DEPLETION: A SUCCESSFUL SCENARIO FOR THE FORMATION OF MARS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Automatic Orientation of Multi-Scale Terrestrial Images for 3D Reconstruction

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