Chemical ecology of Cyclocephala forsteri (Melolonthidae), a threat to macauba oil palm cultivars (Acrocomia aculeata,Arecaceae)

The environmental unsustainability of African oil palm crops is a growing worldwide concern, and the macauba palm in tropical Southern America surges as the most viable substitute for the production of first-generation biodiesel as a renewable fuel. Large-scale cultivation of the macauba palm, however, is bound to suffer a major setback due to the fast emergence of a florivorous pest threat, Cyclocephala forsteri, a scarab beetle species that can severely reduce fruit yield. Like other congenerics, female and male C. forsteri are night-foraging and driven in large numbers to macauba palm inflorescences by specific volatile organic compounds. In the present study, we assessed the kairomonal cues involved in this plant–florivore interaction and their potential application in selective pest management strategies. Headspace samples of the floral fragrance of macauba palms at our study site in Central Brazil were largely dominated by 4-methylanisole (>97% relative amount), which along with the minor constituents 2-isopropyl-3-methoxypyrazine and 2-sec-butyl-3-methoxypyrazine triggered electroantennographic responses from both female and male C. forsteri. Field behavioural assays evidenced that beetles of this species were exclusively attracted to scented traps baited with 4-methylanisole. Increased total scent discharge attained with an ultrasonic piezoelectric diffuser has positively influenced attractiveness efficiency of the trapping setup. 4-Methylanisole is hereby identified as yet another volatile kairomone involved in highly selective attraction of potential pest florivorous cyclocephaline scarabs associated with economically exploitable palms and should be viewed as a key element in short-term integrated management plans for the cultivation of the macauba palm in South America.     

Quantitative proteomic analysis of the interaction between the endophytic plant-growth-promoting bacterium Gluconacetobacter diazotrophicus and sugarcane

Gluconacetobacter diazotrophicus is a plant-growth-promoting bacterium that colonizes sugarcane. In order to investigate molecular aspects of the G. diazotrophicus-sugarcane interaction, we performed a quantitative mass spectrometry-based proteomic analysis by (15)N metabolic labeling of bacteria, root samples, and co-cultures. Overall, more than 400 proteins were analyzed and 78 were differentially expressed between the plant-bacterium interaction model and control cultures. A comparative analysis of the G. diazotrophicus in interaction with two distinct genotypes of sugarcane, SP70-1143 and Chunee, revealed proteins with fundamental roles in cellular recognition. G. diazotrophicus presented proteins involved in adaptation to atypical conditions and signaling systems during the interaction with both genotypes. However, SP70-1143 and Chunee, sugarcane genotypes with high and low contribution of biological nitrogen fixation, showed divergent responses in contact with G. diazotrophicus. The SP70-1143 genotype overexpressed proteins from signaling cascades and one from a lipid metabolism pathway, whereas Chunee differentially synthesized proteins involved in chromatin remodeling and protein degradation pathways. In addition, we have identified 30 bacterial proteins in the roots of the plant samples; from those, nine were specifically induced by plant signals. This is the first quantitative proteomic analysis of a bacterium-plant interaction, which generated insights into early signaling of the G. diazotrophicus-sugarcane interaction.     

Genome sequence of the diazotrophic Gram-positive rhizobacterium Paenibacillus riograndensis SBR5(T)

Paenibacillus riograndensis SBR5(T), a nitrogen-fixing Gram-positive rhizobacterium isolated from a wheat field in the south of Brazil, has a great potential for agricultural applications due to its plant growth promotion effects. Here we present the draft genome sequence of P. riograndensis SBR5(T). Its 7.37-Mb genome encodes determinants of the diazotrophic lifestyle and plant growth promotion, such as nitrogen fixation, antibiotic resistance, nitrate utilization, and iron uptake.     

Palladium(II) complexes of 2-benzoylpyridine-derived thiosemicarbazones: spectral characterization, structural studies and cytotoxic activity

Palladium(II) complexes of 2-benzoylpyridine thiosemicarbazone (H2Bz4DH) and its N4-methyl (H2Bz4M) and N4-phenyl (H2Bz4Ph) derivatives were obtained and fully characterized. [Pd(2Bz4DH)Cl] (1) crystallizes in the monoclinic space group P21/c with a=11.671(1), b=10.405(1), c=13.124(1), beta=115.60(1) degrees and Z=4; [Pd(2Bz4M)Cl] (2) in the monoclinic space group P21/c with a=9.695(1), b=15.044(1), c=10.718(1) A, beta=105.38(1) degrees and Z=4 and [Pd(2Bz4Ph)Cl] (3) in the triclinic space group P1 with a=9.389(1), b=13.629(1), c=15.218(1) A, alpha=70.25(1), beta=73.46(1), gamma=83.57(1) degrees and two independent molecules per asymmetric unit (Z=4). All complexes show a quite similar planar fourfold environment around palladium(II). A negatively charged organic molecule acts as a tridentate ligand and binds to the metal through the pyridine nitrogen, the imine nitrogen and the sulfur atom. A chloride ion occupies the fourth coordination site. The planar complexes stack nearly parallel to one another in the lattice conforming a layered crystal structure. The cytotoxic activity of the thiosemicarbazones and their metal complexes was tested against the MCF-7, TK-10 and UACC-62 human tumor cell lines. The ligands exhibit lower values of GI50 and LC50 than the complexes, H2Bz4Ph being the most active with GI50<0.003 microM; LC50=13.4 microM; GI50=9.3 microM, LC50=12.9 microM; GI50<0.003, LC50=13.8 microM in the MCF-7, TK-10 and UACC-62 cell lines, respectively. Among the complexes, [Pd(2Bz4Ph)Cl] (3) exhibited the lowest values of GI50 in the three studied cell lines.     

Topical Delivery of Coumestrol from Lipid Nanoemulsions Thickened with Hydroxyethylcellulose for Antiherpes Treatment

We have recently shown that coumestrol, an isoflavonoid-like compound naturally occurring in soybeans, alfafa, and red clover, inhibited Herpes Simplex Virus types 1 (HSV-1) and 2 (HSV-2) replication. In this study, we designed coumestrol formulations in an attempt to enable its topical delivery to mucosa tissues. Physicochemical and microscopic examinations suggested that coumestrol was efficiently incorporated in positively-charged nanoemulsions dispersed in a hydroxyethylcellulose gel. The higher coumestrol flux through excised porcine esophageal mucosa was detected from nanoemulsions composed by a fluid phospholipid (dioleylphosphocholine, DOPC) in comparison with that of a rigid one (distearoylphosphocholine, DSPC) in two mucosa conditions (intact and injured). Such results were supported by confocal fluorescence images. Furthermore, the low IC₅₀ values demonstrated an increasement in the antiviral inhibition against HSV-1 and HSV-2 after incorporation of coumestrol into nanoemulsions containing DOPC. Overall, coumestrol-loaded nanoemulsions proved to be beneficial for herpes simplex treatment.     

HbA1c Test as a Tool in the Diagnosis of Gestational Diabetes Mellitus

Aims

Gestational diabetes mellitus (GDM) is a prevalent and potentially serious condition which may put both mothers and neonates at risk. The current recommendation for diagnosis is the oral glucose tolerance test (OGTT). This study aimed to determine the usefulness of HbA1c test as a diagnostic tool for GDM as compared to the traditional criteria based on the OGTT.

Methods

This was a diagnostic test accuracy study. We performed OGTT and HbA1c test in women attending prenatal visits at a tertiary hospital. GDM was defined according to WHO1999 or ADA/WHO 2013 criteria. ROC curve was used to evaluate the diagnostic performance of HbA1c. Sensitivity, specificity and likelihood ratios for different HbA1c cut-off points were calculated.

Results

Of the 262 women in the third trimester of gestation enrolled in the study, 86 (33%) were diagnosed with GDM. Only five of these women presented HbA1c ≥48 mmol/mol (6.5%). This cut-off point presented 100% specificity but very low sensitivity (7%). Based on ROC curve, and considering OGTT as the reference criterion, HbA1c ≥40 mmol/mol (5.8%) showed adequate specificity in diagnosing GDM (94.9%) but low sensitivity (26.4%). Unlike, HbA1c values of 31 mmol/mol (5.0%) presented adequate sensitivity (89.7%) but low specificity (32.6%) to detect GDM. For women with HbA1c ≥40 mmol/mol (5.8%), the positive and negative likelihood ratios were 5.14 (95%CI 2.49–10.63) and 0.78 (0.68–0.88), respectively. The post-test probability of GDM was about 40%, representing a 4.0-fold increase in the mean pre-test probability. This cut-off point could eliminate the need for the unpleasant and laborious OGTT tests in almost one third of cases, as 38% of patients with GDM may be diagnosable by HbA1c test alone.

Conclusions

Our results show that combined HbA1c and OGTT measurements may be useful in diagnosing GDM.     

Tachinids associated with lepidopteran pests in agricultural crops in south-central region of Goiás,Brazil

BioControl - Lepidopterans are among the most important groups of pests for crops in central Brazil. Fortunately, there is a significant diversity of natural enemies acting in the natural...     

Lacunas: a web interface to identify plant knowledge gaps to support informed decision-making

Scientists from megadiverse countries, such as Brazil, face huge challenges in gathering and analyzing information about species richness and abundance. In Brazil, speciesLink is an e-infrastructure that offers free and open access to data from more than 300 biological and data collections. SpeciesLink’s thematic network, INCT-Virtual Herbarium of Plants and Fungi  and the List of Species of the Brazilian Flora, are used as primary data sources to develop Lacunas, an information system with a public web interface that generates detailed reports of the status of plant species occurrence data. Lacunas also integrates information about endemism, conservation status, and collecting efforts over time. Here we describe the motivation and the functionality of this system, showing how it can be useful in detecting under-sampled plant species and geographic areas. We show examples of how knowledge can be extracted from biodiversity primary data using Lacunas. For instance, Lacunas report revealed that 111 angiosperm species (10.3 %), currently considered Data Deficient (DD) in the Official List of Threatened Brazilian Flora, have their distribution well characterized. In addition, the situation of Attalea funifera, a native palm classified as DD, was analyzed in detail, together with other use cases. Information presented in Lacunas reports can thus be used by scientists and policy-makers to help evaluate the status of species occurrence data and prioritize digitization and collecting efforts, as well as some features concerning its conservation status. As Lacunas offers a public online interface, it may also become a valuable tool for helping decision-making processes to become more dynamic and transparent.     

Genotypes and Pathogenicity of Cellulitis Isolates Reveal Traits That Modulate APEC Virulence

We characterized 144 Escherichia coli isolates from severe cellulitis lesions in broiler chickens from South Brazil. Analysis of susceptibility to 15 antimicrobials revealed frequencies of resistance of less than 30% for most antimicrobials except tetracycline (70%) and sulphonamides (60%). The genotyping of 34 virulence-associated genes revealed that all the isolates harbored virulence factors related to adhesion, iron acquisition and serum resistance, which are characteristic of the avian pathogenic E. coli (APEC) pathotype. ColV plasmid-associated genes (cvi/cva, iroN, iss, iucD, sitD, traT, tsh) were especially frequent among the isolates (from 66.6% to 89.6%). According to the Clermont method of ECOR phylogenetic typing, isolates belonged to group D (47.2%), to group A (27.8%), to group B2 (17.4%) and to group B1 (7.6%); the group B2 isolates contained the highest number of virulence-associated genes. Clonal relationship analysis using the ARDRA method revealed a similarity level of 57% or higher among isolates, but no endemic clone. The virulence of the isolates was confirmed in vivo in one-day-old chicks. Most isolates (72.9%) killed all infected chicks within 7 days, and 65 isolates (38.1%) killed most of them within 24 hours. In order to analyze differences in virulence among the APEC isolates, we created a pathogenicity score by combining the times of death with the clinical symptoms noted. By looking for significant associations between the presence of virulence-associated genes and the pathogenicity score, we found that the presence of genes for invasins ibeA and gimB and for group II capsule KpsMTII increased virulence, while the presence of pic decreased virulence. The fact that ibeA, gimB and KpsMTII are characteristic of neonatal meningitis E. coli (NMEC) suggests that genes of NMEC in APEC increase virulence of strains.     

Two-year citations of JAPPL original articles: evidence of a relative age effect

Several indicators have been used to analyze scientific journals, with the impact factor and the number of citations in a 2-yr calendar time frame (2-YRC) being the most common factors. However, considering that the Journal of Applied Physiology (JAPPL) appears monthly and that calculations of these indicators are based on citations of papers published in previous years, we hypothesized that articles published at the beginning of the year would be cited more in the 2-YRC compared with those appearing in the last issues of the year, a phenomena known as a relative age effect. Our objective was to confirm the existence of a relative age effect in the 2-YRC for original articles published in JAPPL. From 2005 to 2008, a total of 1,726 original articles were published, according to the Web of Science, and 9,973 citations in 2-YRC, varying from 0 to 45, with a mean of 5.78 for individual papers. Although there were no differences in the number of original articles published in a given month (P = 0.99), the 2-YRC varied considerably throughout the year, being higher for those earlier issues of the year, as shown by the linear regression analysis (r(2) = 0.76; P < 0.001). The 2-YRC began at 6.62 during the first 3 mo of the year, dropping by 10% at each 3-mo period. In summary, the longer an article has been out there, the more citations it collects. The relative age effect is a potential confounding variable for the assessment and interpretation of 2-YRC (using calendar years) from JAPPL original articles.