Litter accumulation and biomass dynamics in riparian zones in tropical South America of the Asian invasive plant Hedychium coronarium J. König (Zingiberaceae)

ABSTRACT

Background: Promoting changes in abiotic conditions and ecosystem processes, such as decomposition, is a mechanism by which some exotic plant species displace native plants and become invasive.

Aims: We monitored ramets of Hedychium coronarium over 30 months to estimate the litter decay rate, biomass dynamics and litter accumulation over time in riparian sites invaded by the species in southeastern Brazil.

Methods: We measured the number, height, emergence and mortality of ramets in three environments invaded by H. coronarium (natural, rural and urban). We also measured litter decay in situ and in in vitro experiments. We used sinusoidal models to describe height fluctuation and exponential models to simulate litter decay and litter accumulation.

Results: Ramets of H. coronarium showed high seasonal variation in terms of height and emergence, as well as low litter decay. Accordingly, our models predicted high litter production and a seasonal pattern of litter accumulation in invaded sites.

Conclusions: H. coronarium produces a great amount of litter, which shows slow decay and hence seems to affect decomposition processes. Investigating seasonal variation on the effects of invasive species on ecosystem functioning shed light on the factors driving the success and impact of invasive plants.     

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms of hOGG1 (Ser326Cys)

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8‐oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty‐two healthy Caucasian men (40–74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild‐type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG‐sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG‐sensitive sites) and repair activity (OGG1) between genotype groups (in the pre‐training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG‐sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism. Copyright © 2015 John Wiley & Sons, Ltd.     

Liposomal-based lidocaine formulation for the improvement of infiltrative buccal anaesthesia

This study describes the encapsulation of the local anaesthetic lidocaine (LDC) in large unilamellar liposomes (LUV) prepared in a scalable procedure, with hydrogenated soybean phosphatidylcholine, cholesterol and mannitol. Structural properties of the liposomes were assessed by dynamic light scattering, nanoparticle tracking analysis and transmission electron microscopy. A modified, two-compartment Franz-cell system was used to evaluate the release kinetics of LDC from the liposomes. The in vivo anaesthetic effect of liposomal LDC 2% (LUV_LDC) was compared to LDC 2% solution without (LDC_PLAIN) or with the vasoconstrictor epinephrine (1:100 000) (LDC_VASO), in rat infraorbital nerve blockade model. The structural characterization revealed liposomes with spherical shape, average size distribution of 250?nm and low polydispersity even after LDC incorporation. Zeta potential laid around –30?mV and the number of suspended liposomal particles was in the range of 10¹² vesicles/mL. Also the addition of cryoprotectant (mannitol) did not provoke structural changes in liposomes properties. In vitro release profile of LDC from LUV fits well with a biexponential model, in which the LDC encapsulated (EE%?=?24%) was responsible for an increase of 67% in the release time in relation to LDC_PLAIN (p?<?0.05). Also, the liposomal formulation prolonged the sensorial nervous blockade duration (～70?min), in comparison with LDC_PLAIN (45?min), but less than LDC_VASO (130?min). In this context, this study showed that the liposomal formulations prepared by scalable procedure were suitable to promote longer and safer buccal anaesthesia, avoiding side effects of the use of vasoconstrictors.     

Bioaerosol vertical fungal spores profile in Minas Gerais State,Brazil

Aerobiologia - Primary biological aerosol particles (PBAPs) are involved in multiple phenomena ranging from seasonal allergies to pandemic diseases. Furthermore, PBAPs that act as ice nuclei, might...     

Brain and testis: more alike than previously thought?

Several strands of evidence indicate the presence of marked similarities between human brain and testis. Understanding these similarities and their implications has become a topic of interest among the scientific community. Indeed, an association of intelligence with some semen quality parameters has been reported and a relation between dysfunctions of the human brain and testis has also been evident. Numerous common molecular features are evident when these tissues are compared, which is reflected in the huge number of common proteins. At the functional level, human neurons and sperm share a number of characteristics, including the importance of the exocytotic process and the presence of similar receptors and signalling pathways. The common proteins are mainly involved in exocytosis, tissue development and neuron/brain-associated biological processes. With this analysis, we conclude that human brain and testis share several biochemical characteristics which, in addition to their involvement in the speciation process, could, at least in part, be responsible for the expression of a huge number of common proteins. Nonetheless, this is an underexplored topic, and the connection between these tissues needs to be clarified, which could help to understand the dysfunctions affecting brain and testis, as well as to develop improved therapeutic strategies.