11 research outputs found
Structuring Factors Of The Cumacean Communities Of The Continental Shelf Of Southeastern Brazil
Cumaceans are benthic crustaceans distributed worldwide, from intertidal to abyssal plains. They live in sandy and muddy bottoms and can sometimes be found in the water column. Despite their ecological importance as food items for fishes and other organisms and their usefulness as environmental indicators, very few studies have investigated their biodiversity and distribution in Brazil. The present paper reports an ecological study of the cumacean species found on the continental shelf off Santos, southeastern Brazil. It investigates the composition and spatio-temporal structure of the communities, the main environmental factors responsible for the maintenance of that structure and analyzes the effects of the seasonal oceanographic changes on the community descriptors. A grid of 21 stations located between 10 and 100 m depth was created in winter 2005 and summer 2006 and the sediment samples collected with a 0.1 m2 box corer. Twenty four species were obtained, five of them being the most numerous: Diastylis sexpectinata, D. sympterygiae, Eudorella sp., Oxyurostylis salinoi and Anchistylis notus, the latter highly dominant in summer. Diastylis sympterygiae was characteristic of the shallowest and least saline stations (< 16 m depth; S = 33.07 - 34.2) in both seasons. Of the total of 919 individuals, nearly 70% occurred in summer. The area was divided into four depth bands and no significant temporal difference was found as regards the density distribution of cumaceans in those bands as between the samples of the two campaigns. There were, however, spatial differences within bands in the summer campaign: the higher values of density, diversity and richness were close to the 50 m isobath in both campaigns, a fact that could well be attributed to the ongoing effect of the South Atlantic Central Water in this area. The results showed also that depth and the sediment particle size were the main structural factors determining the composition and distribution of the cumacean species
Colour and decay resistance and its relationships in Eperua grandiflora
Eperua grandiflora, which is widely distributed in the French Guiana forest region, shows high variability in decay resistance. Further information concerning this wood
quality parameter is necessary, but standard testing methods are complex and
time-consuming. We assessed the use of colorimetry to determine durability
in heartwood samples from a range of trees. Eperua grandiflora colour parameters were measured using a CIELAB system, revealing that the tree effect was greater than the radial position and height effects. The wood samples were exposed to Coriolus versicolor and Antrodia sp. according to two European standards (En 350-1 and XP CEN TS 15083-1). Eperua grandiflora is more susceptible to brown rot. These two standards did not give the same durability classes. The high variation in natural durability was due to the tree effect. These two properties were found to be correlated and the assessment also
distinguished the extreme durability classes but they are not sufficient to
classify the class of durability of this species.Ătude de la variabilitĂ© de la couleur, de la durabilitĂ©
naturelle et recherche de corrĂ©lations chez Eperua grandiflora. Eperua grandiflora, essence largement rĂ©pandue dans les forĂȘts de Guyane soufre d'un
défaut majeur : une grande variabilité de sa durabilité
naturelle Ă l'Ă©gard des champignons lignivores. Dans un premier
temps, nous avons étudié la variabilité de la mesure de la
couleur selon le systÚme CIElab afin de vérifier si la
colorimĂ©trie peut ĂȘtre utilisĂ©e comme un indicateur de la
durabilitĂ© naturelle. Nous avons Ă©tudiĂ© la rĂ©sistance de cette essence Ă
l'échelle inter, et intra-arbres à l'égard de Coriolus versicolor et Antrodia sp., conformément aux normes européennes en vigueur : EN 350-1 et XP TS
15083-1. Les rĂ©sultats ont rĂ©vĂ©lĂ© qu'Eperua grandiflora est plus sensible au champignon de pourriture brune. De mĂȘme, l'utilisation des normes a montrĂ© que l'on n'obtenait pas
les mĂȘmes classes de durabilitĂ©. La variabilitĂ© de la
durabilité et de la couleur est plus importante à l'échelle
inter-arbres qu'à l'échelle intra-arbre. Enfin, ces deux propriétés sont corrélées mais nous ne
pouvons envisager d'utiliser la colorimétrie comme indicateur de la
durabilité naturelle, car elle ne permet de différencier que les
classes extrĂȘmes
Habitat selection of the pink shrimp farfantepenaeus paulensis and the blue crab callinectes sapidus in an estuary in southern Brazil: influence of salinity and submerged seagrass meadows
This study was conducted in two estuarine inlets (Saco da
Mangueira and Saco do Arraial) at the Patos Lagoon estuary, southern Brazil.
The changes in relative abundance and size of post-larvae and juvenile shrimp
Farfantepenaeus paulensis and juvenile blue crab Callinectes sapidus were
compared, considering the influence of salinity and the presence of submerged
seagrass meadows. The analyses were performed using generalized linear models
(GLM) for abundance variations and ANOVA for variations on the size of
individuals. The pink shrimp was more abundant at Saco da Mangueira, in
seagrass meadows and areas of higher salinity. The blue crab was more abundant
at Saco do Arraial and in lower levels of salinity. The importance of submerged
vegetation for the blue crab lies in a preference of smaller crabs of the species
for the seagrass meadows. It has been shown that these species choose different
habitats in the estuary, and both the salinity and the presence of submerged
seagrass meadows influence the selection of habitat
Crustacea decapoda da praia rochosa da Ilha do Farol, Matinhos, Paranå: II. Distribuição espacial de densidade das populaçÔes
<abstract language="eng">Decapod crustaceans from rocky shore at Farol Isle, Matinhos, ParanĂĄ, Brazil. II. Spatial distribution of population densities. A study of the spatial distribution of the decapod populations from a rocky shore at Farol Isle, Matinhos, State of ParanĂĄ, Brazil (25Âș51'S, 48Âș32'W) was canied out. In the supralittoral the rocky surface is covered partially by a layer of litter coming from the terrestrial habitats; in the midlittoral boulders and pebbles cover the rocky basin and in the infralittoral, there is a belt of seaweeds. A total of 8 samples were taken by hand, two from each of the following levels: supralittoral (emersion time 8-12 hours), upper midlittoral (4-8), lower midlittoral (0-4) and limit between midlittoral and infralittoral, monthly, from May/1990 to April/1991. The number of species increased from supralittoral (5) to infralittoral (22) and a clear vertical zonation on density was observed according to the emersion time gradient. The supralittoral is characterized by grapsids Armases angustipes (Dana, (1852), Cyclograpsus integer H. Milne Edwards, 1837 and Metasesarma rubripes (Rathbun, 1897) which have terrestrial habits and aerial respiration as a main way in obtaining the oxygen. In the midlittoral, the decapods show three basic types of adaptation against emersion desiccation and thermal stresses: (1) by digging into wet mud among the stones such as Panopeus americanus Saussure, 1857, Panopeus occidentalis Saussure, 1857 and Eurypanopeus abbreviatus Stimpson, 1860, (2) by resting in shady and wet space between the boulders and pebbles or underside of them, like Pachygrapsus transversus (Gibbes, 1850), Petrolisthes armatus (Gibbes, 1850) and adults of Menippe nodifrons Stimpson, 1859 and (3) by clinging over the soaked filamentous algae layer on the pebbles or bouders surfaces, a strategy observed in small species such as Pilumnus dasypodus Kingsley, 1879, Podochela sp., Petrolisthes galathinus (Bosc, 1801 ), Alpheus bouvieri A. Milne Edwards, 1878 and juveniles of Menippe nodifrons. In the infralittoral, small species which are vulnerable to desiccation stresses share space by diversification of their diet and adaptation strategies such as camouflage, body color change according to the substratum, flattened body for tight adhesion on hard surface and rapid movements. The main species of this zone are Petrolisthes armatus, Petrolisthes galathinus, juveniles of Menippe nodifrons, Epialtus brasiliensis Dana, 1852, P. dasypodus, Synalpheus fritzmuelleri CoutiĂšre, 1909, Megalobrachium roseum (Rathbun, 1900) and species of Palaemonidae. The rocky shore at Farol Isle is a complex architectural environment due to the conjunction of diversified habitats such as litter over a hard surface, spaces and crevices among boulders and pebbles, muddy substratum and phytal
Partial Loss of USP9X Function Leads to a Male Neurodevelopmental and Behavioral Disorder Converging on Transforming Growth Factor beta Signaling
BACKGROUND: The X-chromosome gene USP9X encodes a deubiquitylating enzyme that has been associated with neurodevelopmental disorders primarily in female subjects. USP9X escapes X inactivation, and in female subjects de novo heterozygous copy number loss or truncating mutations cause haploinsufficiency culminating in a recognizable syndrome with intellectual disability and signature brain and congenital abnormalities. In contrast, the involvement of USP9X in male neurodevelopmental disorders remains tentative.METHODS: We used clinically recommended guidelines to collect and interrogate the pathogenicity of 44 USP9X variants associated with neurodevelopmental disorders in males. Functional studies in patient-derived cell lines and mice were used to determine mechanisms of pathology.RESULTS: Twelve missense variants showed strong evidence of pathogenicity. We define a characteristic phenotype of the central nervous system (white matter disturbances, thin corpus callosum, and widened ventricles); global delay with significant alteration of speech, language, and behavior; hypotonia; joint hypermobility; visual system defects; and other common congenital and dysmorphic features. Comparison of in silico and phenotypical features align additional variants of unknown significance with likely pathogenicity. In support of partial loss-of-function mechanisms, using patient-derived cell lines, we show loss of only specific USP9X substrates that regulate neurodevelopmental signaling pathways and a united defect in transforming growth factor signaling. In addition, we find correlates of the male phenotype in Usp9x brain-specific knockout mice, and further resolve loss of hippocannpal-dependent learning and memory.CONCLUSIONS: Our data demonstrate the involvement of USP9X variants in a distinctive neurodevelopmental and behavioral syndrome in male subjects and identify plausible mechanisms of pathogenesis centered on disrupted transforming growth factor beta signaling and hippocampal function.Genetics of disease, diagnosis and treatmen