Participation of the Cytoskeletal and Lysosomal Compartments in Campylobacter jejuni Invasion of Caco-2 cells, the Cellular Response by Morphometric Analysis and the Presence of Cytokine and Chemokine Transcripts

This study aimed to evaluate the participation of actin and tubulin in the process of internalisation, the interaction of bacterial phagosomes with lysosomes, the morphometric changes and the expression of inflammatory cytokines in Caco-2 cells infected with Campylobacter jejuni. Both actin and tubulin participated in the process of internalisation. Inside the cells, lysosomes fuse with phagosomes, which may lead to bacterial death because after 2 h, the bacteria were not detected by Transmission electron microscopy (TEM). There is increased expression of TGF-β3 during the early stages, and IL-8 was expressed after 60 min p.i. This work showed that C. jejuni invades and causes major morphometric changes in epithelial cells. In response, the cells increase their expression of cytokines that can lead to inflammation. The mechanisms of invasion are dependent on actin and tubulin, and once internalised, lysosomes fuse with phagosomes.     

Dose‐response effects of the antioxidant α‐lipoic acid in the liver and brain of pompano Trachinotus marginatus (Pisces,Carangidae)

This study evaluated the effect of different doses of the antioxidant α‐lipoic acid (LA) administered by intraperitoneal injection on the detoxifying capacity (activity of glutathione‐S‐transferase, GST) and oxidative damage (lipids and proteins) in the pompano, Trachinotus marginatus. The plasma glucose levels showed that there were no differences between the treatments (P > 0.05). In the brain, GST activity was significantly higher (P < 0.05) in fish injected with 40 mg LA kg^?1 when compared with the control group. In the muscle, GST activity was not influenced by LA treatment (P > 0.05). In the liver, fish injected with 20 mg LA kg^?1 showed higher GST activity than the control group (P < 0.05); however, higher doses (40 and 60 mg LA kg^?1) led to a reduction of GST activity in the liver, which was comparable to that observed in the control group (P > 0.05). The two highest LA doses (40 and 60 mg kg^?1) had opposite effects, depending on the tissue examined: LA was an antioxidant in the brain, reducing lipid peroxidation (P < 0.05), and a pro‐oxidant in the liver, augmenting oxidative lipid damage (P < 0.05). The latter effect was accompanied by an increase in the free iron concentration in the liver at higher LA doses. These results indicate the need to thoroughly evaluate the antioxidant effects on aquatic organisms, since at some doses and/or in some organs their beneficial effects can be lost.     

HUMAN COOPERATION BASED ON PUNISHMENT REPUTATION

The threat of punishment usually promotes cooperation. However, punishing itself is costly, rare in nonhuman animals, and humans who punish often finish with low payoffs in economic experiments. The evolution of punishment has therefore been unclear. Recent theoretical developments suggest that punishment has evolved in the context of reputation games. We tested this idea in a simple helping game with observers and with punishment and punishment reputation (experimentally controlling for other possible reputational effects). We show that punishers fully compensate their costs as they receive help more often. The more likely defection is punished within a group, the higher the level of within‐group cooperation. These beneficial effects perish if the punishment reputation is removed. We conclude that reputation is key to the evolution of punishment.     

Deforestation and Reforestation of Latin America and the Caribbean (2001–2010)

Forest cover change directly affects biodiversity, the global carbon budget, and ecosystem function. Within Latin American and the Caribbean region (LAC), many studies have documented extensive deforestation, but there are also many local studies reporting forest recovery. These contrasting dynamics have been largely attributed to demographic and socio‐economic change. For example, local population change due to migration can stimulate forest recovery, while the increasing global demand for food can drive agriculture expansion. However, as no analysis has simultaneously evaluated deforestation and reforestation from the municipal to continental scale, we lack a comprehensive assessment of the spatial distribution of these processes. We overcame this limitation by producing wall‐to‐wall, annual maps of change in woody vegetation and other land‐cover classes between 2001 and 2010 for each of the 16,050 municipalities in LAC, and we used nonparametric Random Forest regression analyses to determine which environmental or population variables best explained the variation in woody vegetation change. Woody vegetation change was dominated by deforestation (?541,835 km²), particularly in the moist forest, dry forest, and savannas/shrublands biomes in South America. Extensive areas also recovered woody vegetation (+362,430 km²), particularly in regions too dry or too steep for modern agriculture. Deforestation in moist forests tended to occur in lowland areas with low population density, but woody cover change was not related to municipality‐scale population change. These results emphasize the importance of quantitating deforestation and reforestation at multiple spatial scales and linking these changes with global drivers such as the global demand for food.     

Dual on-off and off-on switchable oligoaziridine biosensor

A water-soluble biocompatible aziridine-based biosensor with pendant anthracene units was synthesized by radicalar polymerization of N-substituted aziridines in supercritical carbon dioxide. The binding ability of the sensor towards a series of metal ions was examined by comparing the fluorescence intensities of the solutions before and after the addition of 100 equivalents of a solution of the metal ion chloride salt. A fast, simple and highly optical sensitive dual behavior, "off-on" and "on-off" response, was observed after the biosensor was exposed to the metal cations in aqueous solution. Zinc presented the highest fluorescence enhancement (turn-on) and copper presented the highest fluorescence quenching (turn-off). The response time was found to be instantaneous and the detection limit was achieved even in the presence of excess metal cation competitors. By using immunofluorescence microscopy it was also shown that oligoaziridine acts as an "on-off" probe through highly sensitive (detection limit of 1.6nM), selective and reversible binding to copper anions under physiologic conditions using living Human Fibroblast cells. The stoichiometry for the reaction of the biosensor with Cu(2+) was determined by a Job plot and indicates the formation of an oligoaziridine-Cu(2+) 1:2 adduct.     

Seed structure, germination, and reserve mobilization in Butia capitata (Arecaceae)

Butia capitata is a palm tree endemic to the Cerrado biome of Brazil and has significant potential for ornamental and food uses. In this work, we characterized the structures of the seeds and seedlings of this species to identify anatomical aspects related to its pronounced dormancy and determine the processes involved in reserve mobilization. Intact seeds, and seeds from which the operculum had been removed, were allowed to germinate and their morphology, physiology, anatomy, and histochemistry, together with those of the seedlings, were followed for 30 days. The seed coat was found to be rich in phenolic compounds and not lignified. The endosperm contains abundant protein and lipidic reserves, and the embryo has additional starch reserves. Germination occurred only in seeds with their opercula removed and involved the elongation of the cotyledon cells and meristematic activity in the “M zone” located between the embryonic axis and the proximal extremity of the embryo. The mobilization of embryonic reserves initiates during the first phase of imbibition, while the mobilization of endosperm reserves represents a post-germination event associated with the formation of a secretory epidermis and aerenchyma and the vascularization of the haustorium. Seeds with intact opercula did not germinate, but demonstrated embryonic reserve mobilization and cell elongation, indicating that dormancy in B. capitata is related to the incapacity of the embryo to dislocate the operculum.     

Chromosome Painting in Three Species of Buteoninae: A Cytogenetic Signature Reinforces the Monophyly of South American Species

Buteoninae (Falconiformes, Accipitridae) consist of the widely distributed genus Buteo, and several closely related species in a group called “sub-buteonine hawks”, such as Buteogallus, Parabuteo, Asturina, Leucopternis and Busarellus, with unsolved phylogenetic relationships. Diploid number ranges between 2n = 66 and 2n = 68. Only one species, L. albicollis had its karyotype analyzed by molecular cytogenetics. The aim of this study was to present chromosomal analysis of three species of Buteoninae: Rupornis magnirostris, Asturina nitida and Buteogallus meridionallis using fluorescence in situ hybridization (FISH) experiments with telomeric and rDNA probes, as well as whole chromosome probes derived from Gallus gallus and Leucopternis albicollis. The three species analyzed herein showed similar karyotypes, with 2n = 68. Telomeric probes showed some interstitial telomeric sequences, which could be resulted by fusion processes occurred in the chromosomal evolution of the group, including the one found in the tassociation GGA1p/GGA6. In fact, this association was observed in all the three species analyzed in this paper, and also in L. albicollis, suggesting that it represents a cytogenetic signature which reinforces the monophyly of Neotropical buteoninae species.     

Quantification of Anti‐Addictive Alkaloids Ibogaine and Voacangine in In Vivo‐ and In Vitro‐Grown Plants of Two Mexican Tabernaemontana Species

Tabernaemontana alba and Tabernaemontana arborea are Apocynaceae species used in Mexican traditional medicine for which little phytochemical information exists. In this study, preliminary gas chromatography/mass spectrometry analyses of different organs obtained from wild plants of both species identified a total of 10 monoterpenoid indole alkaloids (MIAs) and one simple indole alkaloid, nine of which were reported for the first time in these species. Furthermore, callus cultures were established from T. alba leaf explants and regeneration of whole plants was accomplished via somatic embryogenesis. The anti‐addictive MIAs ibogaine and voacangine were then quantified by gas chromatography with flame ionization detection in wild plants of both species, as well as greenhouse‐grown plants, in vitro‐grown plantlets and embryogenic callus of T. alba. Ibogaine and voacangine were present in most samples taken from the whole plants of both species, with stem and root barks showing the highest concentrations. No alkaloids were detected in callus samples. It was concluded that T. alba and T. arborea are potentially viable sources of ibogaine and voacangine, and that these MIAs can be produced through somatic embryogenesis and whole plant regeneration of T. alba. Approaches to increase MIA yields in whole plants and to achieve alkaloid production directly in cell cultures are discussed.