Diversity distribution and floristic differentiation of the coastal lowland vegetation: implications for the conservation of the Brazilian Atlantic Forest

Floristic differentiation and vegetation definition is an important step to recognize biome distribution and for biodiversity conservation. Here, we aim to verify if the distribution of the costal lowland vegetation in Brazilian littoral is congruent with climatic gradient and the previous vegetation definitions. Additionally we discussed the importance of terms for the Atlantic Forest conservation. Our study was based on floristic and geo-climatic data from 58 published surveys. We generate a checklist of 1088 woody species and verified species distribution according to environmental gradient using a Detrended Correspondence Analysis (DCA). We compared DCA??s groups with the a priori vegetation definition and generate an a posteriori classification using TWINSPAN. DCA and TWINSPAN resulted in groups determined mainly by rainfall (r = ?0.65) and soil sandiness (r = ?0.71). Those groups were not congruent with both the previous vegetation definitions. The coastal lowland vegetation comprises two distinctive floristic groups representing forests and scrubs that occur in wetter climates (Ombrophilous lowland forests) in the Brazilian states of Santa Catarina, Paraná and São Paulo and in drier climates of Espírito Santo, Rio de Janeiro (Restinga-Northern group) and Rio Grande do Sul (Restinga-Southern group) states. The floristic and historical relationships between Ombrophylous lowland forests and Restingas suggest that conservation initiatives should be more conservative and treat collectively all coastal lowland vegetation as a biodiversity hotspot.     

Polytene chromosomes and nucleic acid metabolism during macronuclear development in Euplotes

Polytene chromosomes in two species of Euplotes, E. woodruffi and E. eurystomus, have been described during the macronuclear development following conjugation. In these two species, the giant chromosomes appear briefly in the macronuclear anlagen and disappear completely later. DNA synthesis begins concomitantly with the appearance of the giant chromosomes and reaches a peak at the maximum stage of polyteny. Shortly thereafter DNA begins to break down and the breakdown products leave the macronuclear anlagen, reducing the DNA content in the anlagen to the amount present at the earlier stages of the polytene development of the chromosomes. A later phase of DNA synthesis occurs in the anlagen with the appearance of replication bands comparable to the bands which double the DNA in the somatic macronucleus. These replication bands initiate several rounds of DNA synthesis which finally lead to the development of the vegetative macronucleus. RNA synthesis occurs uniformly on the giant chromosomes and no special RNA producing puffs or other regions are noticed on them.Research supported by American Cancer Society grant E 434 to David M. Prescott and by the Deutsche Forschungsgemeinschaft to Dieter Ammermann.     

Assessment of microbial diversity in biofilms recovered from endotracheal tubes using culture dependent and independent approaches

Ventilator-associated pneumonia (VAP) is a common nosocomial infection in mechanically ventilated patients. Biofilm formation is one of the mechanisms through which the endotracheal tube (ET) facilitates bacterial contamination of the lower airways. In the present study, we analyzed the composition of the ET biofilm flora by means of culture dependent and culture independent (16 S rRNA gene clone libraries and pyrosequencing) approaches. Overall, the microbial diversity was high and members of different phylogenetic lineages were detected (Actinobacteria, beta-Proteobacteria, Candida spp., Clostridia, epsilon-Proteobacteria, Firmicutes, Fusobacteria and gamma-Proteobacteria). Culture dependent analysis, based on the use of selective growth media and conventional microbiological tests, resulted in the identification of typical aerobic nosocomial pathogens which are known to play a role in the development of VAP, e.g. Staphylococcus aureus and Pseudomonas aeruginosa. Other opportunistic pathogens were also identified, including Staphylococcus epidermidis and Kocuria varians. In general, there was little correlation between the results obtained by sequencing 16 S rRNA gene clone libraries and by cultivation. Pyrosequencing of PCR amplified 16 S rRNA genes of four selected samples resulted in the identification of a much wider variety of bacteria. The results from the pyrosequencing analysis suggest that these four samples were dominated by members of the normal oral flora such as Prevotella spp., Peptostreptococcus spp. and lactic acid bacteria. A combination of methods is recommended to obtain a complete picture of the microbial diversity of the ET biofilm.     

The WD repeat protein FAN regulates lysosome size independent from abnormal downregulation/membrane recruitment of protein kinase C

FAN (factor associated with neutral sphingomyelinase [N-SMase] activation) exhibits striking structural homologies to Lyst (lysosomal trafficking regulator), a BEACH protein whose inactivation causes formation of giant lysosomes/Chediak-Higashi syndrome. Here, we show that cells lacking FAN show a statistically significant increase in lysosome size (although less pronounced as Lyst), pointing to previously unrecognized functions of FAN in regulation of the lysosomal compartment. Since FAN regulates activation of N-SMase in complex with receptor for activated C-kinase (RACK)1, a scaffolding protein that recruits and stabilizes activated protein kinase C (PKC) isotypes at cellular membranes, and since an abnormal (calpain-mediated) downregulation/membrane recruitment of PKC has been linked to the defects observed in Lyst-deficient cells, we assessed whether PKC is also of relevance in FAN signaling. Our results demonstrate that activation of PKC is not required for regulation of N-SMase by FAN/RACK1. Conversely, activation of PKC and recruitment/stabilization by RACK1 occurs uniformly in the presence or absence of FAN (and equally, Lyst). Furthermore, regulation of lysosome size by FAN is not coupled to an abnormal downregulation/membrane recruitment of PKC by calpain. Identical results were obtained for Lyst, questioning the previously reported relevance of PKC for formation of giant lysosomes and in Chediak-Higashi syndrome. In summary, FAN mediates activation of N-SMase as well as regulation of lysosome size by signaling pathways that operate independent from activation/membrane recruitment of PKC.     

Baring it all: undressing Cambrian ‘Orsten’ phosphatocopine crustaceans using synchrotron radiation X‐ray tomographic microscopy

Synchrotron radiation X‐ray tomographic microscopy (SRXTM) was used to virtually dissect and peel the shields off of the microscopic, bivalved phosphatocopine crustaceans in the Cambrian ‘Orsten’ type of preservation of Sweden. Doing so opened up for an array of concealed internal structures to be observed in a fully enclosed specimen of Hesslandona ventrospinata and a semi‐enclosed specimen of Hesslandona angustata. For comparison, also a head‐larva stage specimen of H. angustata, with shields in ‘butterfly position’, was analysed. The X‐ray tomographic data sets revealed excellently preserved structures, such as labrum, sternum, antennae, mandibular and post‐mandibular limbs with their minute setae, all of which were more or less disguised by the enclosing shields. This, moreover, allowed assignment to growth stages of the specimens, which is impossible based solely on external morphology and size. Micro‐spherules observed inside the shields of the semi‐enclosed H. angustata specimen may represent remains of food particles, and the feeding biology of phosphatocopines is discussed in detail. Our analyses suggest that phosphatocopines were particle feeders. The SRXTM technique offers the ability to three‐dimensionally reconstruct the morphology in high resolution, construct virtual serial sections and study concealed structures. The resulting data allow for new structures to be revealed for previously known taxa and for new taxa to be identified, with the added benefit of not destroying the specimens in the process. Hence, we do not longer have to rely on serendipitous finds of broken and/or open phosphatocopine specimens to elucidate their diagnostic ventral morphology.     

The apoptosis inhibitory domain of FE65-like protein 1 regulates both apoptotic and caspase-independent programmed cell death mediated by tumor necrosis factor

Tumor necrosis factor (TNF) can induce caspase-dependent (apoptotic) and caspase-independent pathways to programmed cell death (PCD). Here, we demonstrate that stable transfection of a cDNA encompassing the C-terminal apoptosis inhibitory domain (AID) of FE65-like protein 1 into mouse L929 fibrosarcoma cells protects from caspase-independent as well as from apoptotic PCD induced by TNF. We show that the AID does not protect from caspase-independent PCD elicited by 1-methyl-3-nitro-1-nitrosoguanidine, suggesting that the AID might prevent cell death by affecting assembly of the death inducing signaling complex of the 55 kDa TNF receptor or clustering of the receptor itself. Interference with caspase-independent PCD mediated by the sphingolipid ceramide further increases protection conferred by the AID, as does the antioxidant butylated hydroxyanisole, implicating ceramide and reactive oxygen species as potential factors interacting with caspase-independent PCD regulated by the AID.     

Pranceacanthus coccineus (Acanthaceae), a new genus and species from Amazonian brazil

The new genusPranceacanthus, apparently most closely related to the bitypic genusJuruasia, is described and illustrated. Its sole species,P. coccineus, has been collected on “terra firma” in lowland Amazonian Brazil in the states of Amazonas and Mato Grosso and in the territory of Rondônia.     

A cellulase/xylanase-negative mutant of Streptomyces lividans 1326 defective in cellobiose and xylobiose uptake is mutated in a gene encoding a protein homologous to ATP-binding proteins

Centre de Recherche en Microbiologie Appliquée, Institut Armand-Frappier, Université du Québec, Ville de Laval, Québec H7N 4Z3, Canada.     

Modellversuche zur überlebensdauer von Erwinia amylovora im Verdauungstrakt der Honigbiene,im Honig und an Teilen des Bienenstocks

An lagerndem Winterknoblauch ist unter außenluft‐(x + 6, 5 bzw. 8, 3 °C) und maschinengekühlten Bedingungen (x‐1 . . .‐2 °C) in zwei Lagerperioden die Entwicklung der einzelnen Fäuleerreger verfolgt und in Abhängigkeit von der Lagerdauer statistisch quantifiziert worden. An Hand des Masseanteiles befallener Zwiebeln und der Befallsintensität wird eine zunehmende Ausbreitung von Penicillium spp. und einer Gruppe mit Befall durch mehrere Fäuleerreger unter beiden Lagerbedingungen und von einer Botrytis‐Species (vermutlich B. porri Buchw.) im maschinengekühlten Lager belegt. Fäuleverluste durch Helminthosporium allii Campanile und Bakterien zeigen dagegen mit fortschreitender Lagerdauer einen abnehmenden Verlauf. Mit Eintreten von lagerungsbedingter Seneszenz steigen die Verluste progressiv an. Kaltlagerbedingungen verzögern dagegen ihre Ausbreitung. Die Verluste durch alle Fäulerreger (Fäule gesamt) zeigen eine gleichmäßige Zunahme während der Lagerdauer.     

Use of microbial peptide inhibitors for characterization of the substrate specificity of thermitase,a thermostable serine protease fromThermoactinomyces vulgaris

Seven microbial peptide inhibitors—chymostatin, antipain, elastatinal, leupeptin, pepstatin, bestatin, and phosphoramidon—were tested for their efficiency to inhibit thermitase, a thermostable serine protease fromThermoactinomyces vulgaris. Chymostatin and antipain were the most effective inhibitors, with K_i values of 7×10^–8 M and 2×10^–7 M, respectively. Except for leupeptin, all inhibitors resist hydrolysis by thermitase. Leupeptin, however, is cleaved by thermitase between the two leucylresidues. Further, a close relationship in specificity between thermitase and subtilisin BPN and their distinct discrimination from elastase specificity was demonstrated by using these inhibitors.