Tropical Bacillus Strains Inoculation Enhances Maize Root Surface Area,Dry Weight,Nutrient Uptake and Grain Yield

Journal of Plant Growth Regulation - The rising demand for agricultural commodities in developing countries has put increasing pressure on land resources for higher yields, with associated growth...     

Synergistic effects of habitat configuration and land-use intensity shape the structure of bird assemblages in human-modified landscapes across three major neotropical biomes

Maximizing biodiversity persistence in heterogeneous human-modified landscapes is hindered by the complex interactions between habitat quality and configuration of native and non-native habitats. Here we examined these complex interactions considering avian diversity across 26 sampling sites, each of which comprised of three sampling points located across a gradient of disturbance: core native habitat fragment, fragment edge, and non-native adjacent matrix. The 78 sampling points were further nested within three neotropical biomes—Amazonia, Cerrado and Pantanal—in central-western Brazil. Matrix type consisted of cattle pastures in the Amazon and teak plantations in the Pantanal and Cerrado. We considered the interactive effects of (1) disturbance-context: fragment core, edge and adjacent matrix, (2) matrix type: tree plantation or cattle pastures, both subject to varying land-use intensity, and (3) native habitat configuration (fragment size, shape and isolation) on bird species richness, abundance and composition. Based on point-count surveys, we recorded 210 bird species. Bird species richness and abundance declined across the disturbance gradient, while genus composition only differed within the adjacent matrix, particularly cattle-pastures. The effect of native habitat area was positive but only detected at fragment edges. Overall bird diversity increased at sites characterized by higher availability of either relict trees within pasture landscapes or old-growth trees within teak plantation landscapes. The core of native fragments played a primary role in ensuring the persistence of bird diversity, regardless of fragment size. In contrast to pastures, tree plantations likely harbour a higher proportion of forest-dependent species while bird diversity can be further enhanced by reduced management intensity in both matrix types. Strategies to maximize avian persistence should not only include retaining native habitats, but also maximizing the size of core native habitats. Likewise, more structurally complex matrix types should be encouraged while maintaining low levels of land-use intensity.

     

The effect of riverine networks on fish β-diversity patterns in a Neotropical system

Hydrobiologia - We investigated how the riverine network influences taxonomic and functional beta diversity patterns of fish assemblages in the mainstem/headwater (lateral) and upstream/downstream...     

New Ecuadorian records of the eyeless banjo catfish Micromyzon akamai (Siluriformes: Aspredinidae) expand the species range and reveal intraspecific morphological variation

Two specimens of Micromyzon akamai, an eyeless and miniaturized species previously known only from the deep channels of the eastern Amazon basin in Brazil, are reported from the Curaray River, a tributary of the Napo River in Ecuador. The new specimens are the first records of Micromyzon in the headwaters of the Amazon River and the first records of M. akamai outside Brazil. External morphological characters and a phylogenetic analysis of cytochrome c oxidase I (coI) gene support the identification of the new specimens as M. akamai. Nevertheless, the new specimens also indicate that some features previously hypothesized to be apomorphic for M. akamai are intraspecifically variable.     

Potent Anti-Candida Fraction Isolated from Capsicum chinense Fruits Contains an Antimicrobial Peptide That is Similar to Plant Defensin and is Able to Inhibit the Activity of Different α-Amylase Enzymes

Antimicrobial peptides (AMPs) are molecules present in several life forms, possess broad-spectrum of inhibitory activity against pathogenic microorganisms, and are a promising alternative to combat the multidrug resistant pathogens. The aim of this work was to identify and characterize AMPs from Capsicum chinense fruits and to evaluate their inhibitory activities against yeasts of the genus Candida and α-amylases. Initially, after protein extraction from fruits, the extract was submitted to anion exchange chromatography resulting two fractions. Fraction D1 was further fractionated by molecular exclusion chromatography, and three fractions were obtained. These fractions showed low molecular mass peptides, and in fraction F3, only two protein bands of approximately 6.5 kDa were observed. Through mass spectrometry, we identified that the lowest molecular mass protein band of fraction F3 showed similarity with AMPs from plant defensin family. We named this peptide CcDef3 (Capsicum chinense defensin 3). The antifungal activity of these fractions was analyzed against yeasts of the genus Candida. At 200 μg/mL, fraction F1 inhibited the growth of C. tropicalis by 26%, fraction F2 inhibited 35% of the growth of C. buinensis, and fraction F3 inhibited all tested yeasts, exhibiting greater inhibition activity on the growth of the yeast C. albicans (86%) followed by C. buinensis (69%) and C. tropicalis (21%). Fractions F1 and F2 promoted membrane permeabilization of all tested yeasts and increased the endogenous induction of reactive oxygen species (ROS) in C. buinensis and C. tropicalis, respectively. We also observed that fraction F3 at a concentration of 50 µg/mL inhibited the α-amylase activities of Tenebrio molitor larvae by 96% and human salivary by 100%. Thus, our results show that fraction F3, which contains CcDef3, is a very promising protein fraction because it has antifungal potential and is able to inhibit the activity of different α-amylase enzymes.

     

Cardamonin Presents in Vivo Activity against Schistosoma mansoni and Inhibits Potato Apyrase

Schistosomiasis, a neglected tropical disease caused by Schistosoma species, harms over 250 million people in several countries. The treatment is achieved with only one drug, praziquantel. Cardamonin, a natural chalcone with in vitro schistosomicidal activity, has not been in vivo evaluated against Schistosoma. In this work, we evaluated the in vivo schistosomicidal activities of cardamonin against Schistosoma mansoni worms and conducted enzymatic apyrase inhibition assay, as well as molecular docking analysis of cardamonin against potato apyrase, S. mansoni NTPDase 1 and S. mansoni NTPDase 2. In a mouse model of schistosomiasis, the oral treatment with cardamonin (400 mg/kg) showed efficacy against S. mansoni, decreasing the total worm load in 46.8 % and reducing in 54.5 % the number of eggs in mice. Cardamonin achieved a significant inhibition of the apyrase activity and the three-dimensional structure of the potato apyrase, obtained by homology modeling, showed that cardamonin may interact mainly through hydrogen bonds. Molecular docking studies corroborate with the action of cardamonin in binding and inhibiting both potato apyrase and S. mansoni NTPDases.     

Casearia sylvestris Essential Oil Degradation Products Generated by Leaf Processing

Casearia sylvestris is an endemic tree of the Latin America that the essential oil (EO) has anti-inflammatory and gastroprotective actions. This study evaluates the chemical composition of the EO from the volatile fractions of in natura, fresh, and dried C. sylvestris var. sylvestris and var. lingua leaves. For both varieties, the dried leaves presented higher EO yield as compared to fresh leaves. The major EO chemical components were (E)-caryophyllene, α-humulene, germacrene D, bicyclogermacrene, spathulenol, caryophyllene oxide, and humulene epoxide II. In both varieties, the content of sesquiterpene hydrocarbons decreased and oxygenated sesquiterpenes increased on going from in natura to fresh and dried leaves, which indicated that leaf drying and hydrodistillation modified the volatile composition. The results also suggested that bicyclogermacrene and (E)-caryophyllene were oxidized during processing, to generate spathulenol and caryophyllene oxide, respectively. C. sylvestris varieties and in natura, fresh, and dried leaves differed in terms of the chemical composition of volatiles, which could affect the EO biological activities.     

The largest moss carpet transplant in Antarctica and its bryosphere cryptic biodiversity

Extremophiles - As part of the reconstruction of the Brazilian Antarctic Station on King George Island, three areas of moss carpet were transplanted to minimize the impact of the new facilities on...     

Genetic and morphological divergence between Littorina fabalis ecotypes in Northern Europe

Low dispersal marine intertidal species facing strong divergent selective pressures associated with steep environmental gradients have a great potential to inform us about local adaptation and reproductive isolation. Among these, gastropods of the genus Littorina offer a unique system to study parallel phenotypic divergence resulting from adaptation to different habitats related with wave exposure. In this study, we focused on two Littorina fabalis ecotypes from Northern European shores and compared patterns of habitat‐related phenotypic and genetic divergence across three different geographic levels (local, regional and global). Geometric morphometric analyses revealed that individuals from habitats moderately exposed to waves usually present a larger shell size with a wider aperture than those from sheltered habitats. The phenotypic clustering of L. fabalis by habitat across most locations (mainly in terms of shell size) support an important role of ecology in morphological divergence. A genome scan based on amplified fragment length polymorphisms (AFLPs) revealed a heterogeneous pattern of differentiation across the genome between populations from the two different habitats, suggesting ecotype divergence in the presence of gene flow. The contrasting patterns of genetic structure between nonoutlier and outlier loci, and the decreased sharing of outlier loci with geographic distance among locations are compatible with parallel evolution of phenotypic divergence, with an important contribution of gene flow and/or ancestral variation. In the future, model‐based inference studies based on sequence data across the entire genome will help unravelling these evolutionary hypotheses, improving our knowledge about adaptation and its influence on diversification within the marine realm.     

Relationship between ventilatory threshold and muscle fiber conduction velocity responses in trained cyclists

The relationship between surface electromyography (SEMG) amplitude and the ventilatory threshold has been extensively studied. However, previous studies of muscle fiber conduction velocity (MFCV) are scarce and present insufficient evidence concerning the relationship between MFCV and metabolic responses during cycling. Based on that fact, the purpose of this study is twofold: (1) to investigate the existence of a MFCV threshold (MFCVT) during cycling and (2) to verify if this possible breakpoint is correlated with the ventilatory threshold (VT) and the SEMG threshold (SEMGT). Eight trained male cyclists (age 36.0 ± 9.7 years) performed an incremental cycling test with initial workload of 150 W gradually incremented by 20 W min^?1 until the exhaustion. Gas analyses were conducted using a breath-by-breath open-circuit spirometry and SEMG were registered from vastus lateralis in each pedaling cycle with a linear array of electrodes. A bi-segmental linear regression computer algorithm was used to estimate VT, MFCVT and SEMGT respectively in the carbon dioxide production (VCO₂), MFCV and electromyography root mean square (EMG RMS) curves. The one way ANOVA for repeated measures did not reveal any significant difference among VT (77.1 ± 7.5% of VO₂max), MFCVT (80.3 ± 10.4% of VO₂max) and SEMGT (81.9 ± 11.7% of VO₂max). The Bland and Altman procedure confirmed a good concordance between SEMGT and VT (Bias = 5.5 of %VO₂max) as well as MFCVT and VT (Bias = 5.2 of %VO₂max). The present findings suggest that muscle fiber conduction velocity threshold is a valid and reliable non-invasive tool to obtain information about ventilatory threshold in trained cyclists.