CONTROL OF GLYPHOSATE RESISTANT HAIRY FLEABANE (Conyza bonariensis) WITH DICAMBA AND 2,4-D

Auxyn type herbicides such as dicamba and 2,4-D are alternative herbicides that can be used to control glyphosate-resistant hairy fleabane. With the forthcoming possibility of releasing dicamba-resistant and 2,4-D-resistant crops, use of these growth regulator herbicides will likely be an alternative that can be applied to the control of glyphosate resistant hairy fleabane (Conyza bonariensis). The objective of this research was to model the efficacy, through dose-response curves, of glyphosate, 2,4-D, isolated dicamba and glyphosate-dicamba combinations to control a brazilian hairy fleabane population resistant to glyphosate. The greenhouse dose-response studies were conducted as a completely randomized experimental design, and the rates used for dose response curve construction were 0, 120, 240, 480, 720 and 960 ga.i. ha(-1) for 2,4-D, dicamba and the dicamba combination, with glyphosate at 540 g a. e. ha(-1). The rates for glyphosate alone were 0, 180, 360, 540, 720 and 960 g a. e. ha(-1). Herbicides were applied when the plants were in a vegetative stage with 10 to 12 leaves and height between 12 and 15 cm. Hairy fleabane had low sensitivity to glyphosate, with poor control even at the 960 g a. e. ha(-1) rate. Dicamba and 2,4-D were effective in controlling the studied hairy fleabane. Hairy fleabane responds differently to 2,4-D and dicamba. The combination of glyphosate and dicamba was not antagonistic to hairy fleabane control, and glyphosate may cause an additive effect on the control, despite the population resistance.

Control of glyphosate resistant hairy fleabane (Conyza bonariensis) with dicamba and 2,4-D

Auxyn type herbicides such as dicamba and 2,4-D are alternative herbicides that can be used to control glyphosate-resistant hairy fleabane. With the forthcoming possibility of releasing dicamba-resistant and 2,4-D-resistant crops, use of these growth regulator herbicides will likely be an alternative that can be applied to the control of glyphosate resistant hairy fleabane (Conyza bonariensis). The objective of this research was to model the efficacy, through dose-response curves, of glyphosate, 2,4-D, isolated dicamba and glyphosatedicamba combinations to control a brazilian hairy fleabane population resistant to glyphosate. The greenhouse dose-response studies were conducted as a completely randomized experimental design, and the rates used for dose response curve construction were 0, 120, 240, 480, 720 and 960 g a.i. ha-1 for 2,4-D, dicamba and the dicamba combination, with glyphosate at 540 g a.e. ha-1. The rates for glyphosate alone were 0, 180, 360, 540, 720 and 960 g a.e. ha-1. Herbicides were applied when the plants were in a vegetative stage with 10 to 12 leaves and height between 12 and 15 cm. Hairy fleabane had low sensitivity to glyphosate, with poor control even at the 960 g a.e. ha-1 rate. Dicamba and 2,4-D were effective in controlling the studied hairy fleabane. Hairy fleabane responds differently to 2,4-D and dicamba. The combination of glyphosate and dicamba was not antagonistic to hairy fleabane control, and glyphosate may cause an additive effect on the control, despite the population resistance.

Physiological effects of glyphosate over amino acid profile in conventional and transgenic soybean (Glycine max)

This paper compares the responses of conventional and transgenic soybean to glyphosate application in terms of the contents of 17 detectable soluble amino acids in leaves, analyzed by HPLC and fluorescence detection. Glutamate, histidine, asparagine, arginine + alanine, glycine + threonine and isoleucine increased in conventional soybean leaves when compared to transgenic soybean leaves, whereas for other amino acids, no significant differences were recorded. Univariate analysis allowed us to make an approximate differentiation between conventional and transgenic lines, observing the changes of some variables by glyphosate application. In addition, by means of the multivariate analysis, using principal components analysis (PCA), cluster analysis (CA) and linear discriminant analysis (LDA) it was possible to identify and discriminate different groups based on the soybean genetic origin. (C) 2011 Elsevier Inc. All rights reserved.

Glyphosate has low toxicity to citrus plants growing in the field

Gravena, R., Filho, R. V., Alves, P. L. C. A., Mazzafera, P. and Gravena, A. R. 2012. Glyphosate has low toxicity to citrus plants growing in the field. Can. J. Plant Sci. 92: 119-127. There has been controversy over whether glyphosate used for weed management in citrus fields causes significant toxicity to citrus plants. Glyphosate may be toxic to non-target plants exposed to accidental application or drift. This work evaluated glyphosate toxicity in plants of Valencia citrus (Citrus sinensis. L. Osbeck) grafted onto 'Rangpur lime' (Citrus limonia L. Osbeck) and citrumelo 'Swingle' (Poncirus trifoliata (L.) Raf x Citrus paradisi Mad) by trunk- or foliar-directed herbicide applications under field conditions. In the first experiment, glyphosate was sprayed at rates of 0, 90, 180, 260, 540, 1080 and 2160 g a.e. ha(-1) directly on the trunk to a height of 5 cm above the grafting region. In the second experiment, glyphosate was sprayed on the plant canopies at rates of 0, 0.036, 0.36, 3.6, 36, 360 and 720 g a.e. ha(-1). There was no visual damage caused by glyphosate applied directly to the trunk, but the plants were affected by glyphosate sprayed directly on the canopies at rates over 360 g a.e. ha(-1). The main symptom was observed in the new shoots formed after the application, indicating an effect on meristems. Little or no effect was observed in mature leaves. Eight days after application the levels of shikimate, total free amino acids and total phenolic compounds were unaffected. All plants affected by glyphosate recovered between 6 and 12 mo after the treatments. Therefore, despite some transient symptoms Valencia citrus grafted onto 'Rangpur lime' and citrumelo 'Swingle' were tolerant to glyphosate.

Glyphosate impairs male offspring reproductive development by disrupting gonadotropin expression

Sexual differentiation in the brain takes place from late gestation to the early postnatal days. This is dependent on the conversion of circulating testosterone into estradiol by the enzyme aromatase. The glyphosate was shown to alter aromatase activity and decrease serum testosterone concentrations. Thus, the aim of this study was to investigate the effect of gestational maternal glyphosate exposure (50 mg/kg, NOAEL for reproductive toxicity) on the reproductive development of male offspring. Sixty-day-old male rat offspring were evaluated for sexual behavior and partner preference; serum testosterone concentrations, estradiol, FSH and LH; the mRNA and protein content of LH and FSH; sperm production and the morphology of the seminiferous epithelium; and the weight of the testes, epididymis and seminal vesicles. The growth, the weight and age at puberty of the animals were also recorded to evaluate the effect of the treatment. The most important findings were increases in sexual partner preference scores and the latency time to the first mount; testosterone and estradiol serum concentrations; the mRNA expression and protein content in the pituitary gland and the serum concentration of LH; sperm production and reserves; and the height of the germinal epithelium of seminiferous tubules. We also observed an early onset of puberty but no effect on the body growth in these animals. These results suggest that maternal exposure to glyphosate disturbed the masculinization process and promoted behavioral changes and histological and endocrine problems in reproductive parameters. These changes associated with the hypersecretion of androgens increased gonadal activity and sperm production.

A study of multidrug-resistant tuberculosis in risk groups in the city of Santos, Sao Paulo, Brazil

Monitoring the extent of and trends in multidrug-resistant tuberculosis (MDR-TB) is a priority of the Brazilian National Tuberculosis Control Programme. The current study aimed to estimate the incidence of MDR-TB, describe the profile of TB drug resistance in risk groups and examine whether screening for MDR-TB adhered to the recommended guidelines. A descriptive study that examined diagnosed cases of pulmonary TB was conducted in the city of Santos, Brazil, between 2000-2004. Of the 2,176 pulmonary TB cases studied, 671 (30.8%) met the criteria for drug sensitivity testing and, of these cases, 31.7% (213/671) were tested. Among the tested cases, 9.4% were resistant to one anti-TB drug and 15% were MDR. MDR was observed in 11.6% of 86 new TB cases and 17.3% of 127 previously treated cases. The average annual incidence of MDR-TB was 1.9 per 100,000 inhabitants-years. The extent of known MDR-TB in the city of Santos is high, though likely to be underestimated. Our study therefore indicates an inadequate adherence to the guidelines for MDR-TB screening and suggests the necessity of alternative strategies of MDR-TB surveillance.

Anti-CD25 Treatment Depletes Treg Cells and Decreases Disease Severity in Susceptible and Resistant Mice Infected with Paracoccidioides brasiliensis

Regulatory T (Treg) cells are fundamental in the control of immunity and excessive tissue pathology. In paracoccidioidomycosis, an endemic mycosis of Latin America, the immunoregulatory mechanisms that control the progressive and regressive forms of this infection are poorly known. Due to its modulatory activity on Treg cells, we investigated the effects of anti-CD25 treatment over the course of pulmonary infection in resistant (A/J) and susceptible (B10.A) mice infected with Paracoccidioides brasiliensis. We verified that the resistant A/J mice developed higher numbers and more potent Treg cells than susceptible B10.A mice. Compared to B10.A cells, the CD4(+)CD25(+)Foxp3(+) Treg cells of A/J mice expressed higher levels of CD25, CTLA4, GITR, Foxp3, LAP and intracellular IL-10 and TGF-beta. In both resistant and susceptible mice, anti-CD25 treatment decreased the CD4(+)CD25(+)Foxp3(+) Treg cell number, impaired indoleamine 2,3-dioxygenase expression and resulted in decreased fungal loads in the lungs, liver and spleen. In A/J mice, anti-CD25 treatment led to an early increase in T cell immunity, demonstrated by the augmented influx of activated CD4(+) and CD8(+) T cells, macrophages and dendritic cells to the lungs. At a later phase, the mild infection was associated with decreased inflammatory reactions and increased Th1/Th2/Th17 cytokine production. In B10.A mice, anti-CD25 treatment did not alter the inflammatory reactions but increased the fungicidal mechanisms and late secretion of Th1/Th2/Th17 cytokines. Importantly, in both mouse strains, the early depletion of CD25(+) cells resulted in less severe tissue pathology and abolished the enhanced mortality observed in susceptible mice. In conclusion, this study is the first to demonstrate that anti-CD25 treatment is beneficial to the progressive and regressive forms of paracoccidioidomycosis, potentially due to the anti-CD25-mediated reduction of Treg cells, as these cells have suppressive effects on the early T cell response in resistant mice and the clearance mechanisms of fungal cells in susceptible mice.

Ultraviolet-radiation-resistant isolates revealed cellulose-degrading species of Cellulosimicrobium cellulans (UVP1) and Bacillus pumilus (UVP4)

Among extremophiles, microorganisms resistant to ultraviolet radiation (UVR) have been known to produce a variety of metabolites (i.e., extremolytes). We hypothesized that natural microbial flora on elevated land (hills) would reveal a variety of UVR-resistant extremophiles and polyextremophiles with modulated proteins and enzymes that had biotechnological implications. Microorganisms Cellulosimicrobium cellulans UVP1 and Bacillus pumilus UVP4 were isolated and identified using 16S rRNA sequencing, and showed extreme UV resistance (1.03 x 106 and 1.71 x 105 similar to J/m2, respectively) from elevated land soil samples along with unique patterns of protein expression under UVR and non-UVR. A broad range of cellulolytic activity on carboxymethyl cellulose agar plates in C. cellulans UVP1 and B. pumilus UVP4 was revealed at varying pH, temperature, and inorganic salt concentration. Further, the microbial strain B. pumilus UVP4 showed the basic characteristics of a novel group: polyextremophiles with significance in bioenergy.

Interaction between toxigenic fungi and weevils in corn grain samples

This study investigated the ability of weevils to transmit Aspergillus flavus and Fusarium verticillioides fungal spores and the consequent production of mycotoxins. For this purpose, corn grain samples were stored in flasks connected to a hose to form a closed system (flasks A and B). Flasks A were inoculated with the following groups: group 1 (corn + weevil); group 2 (corn + A. flavus); group 3 (corn + A. flavus + weevil); group 4 (corn + F. verticillioides); group 5 (corn + E verticillioides + weevil), and group 6 (corn + A. flavus + E verticillioides + weevil). Flasks B contained sterile grains. The samples were incubated for 10, 20 and 30 days, posteriorly, weight, water activity, mycoflora, aflatoxins and fumonisins. The corn grain samples were also submitted to scanning electron microscopy. Our results showed that weevils could enhance corn grains contamination by these fungi, hence, could increase mycotoxins production. These findings demonstrate the importance of weevils as fungal vectors and the need for good manipulation and storage practices of grains. (C) 2012 Elsevier Ltd. All rights reserved.

Phosphorus utilization by corn as affected by green manure, nitrogen and phosphorus fertilizers

The objective of this work was to evaluate the utilization by corn plants of P from triple superphosphate fertilizer labeled with P-32 (P-32-TSP), and of P from soil as affected by N rates and by the green manures (GM) sunn hemp (Crotalaria juncea) and millet (Pennisetum glaucum). The experiment was carried out using pots filled with 5 kg Oxisol (Rhodic Hapludox). A completely randomized design was used, in a 4x4x2 factorial arrangement, with four replicates. The treatments were: four P rates as TSP (0, 0.175, 0.350, and 0.700 g P per pot); four N rates as urea (0, 0.75, 1.50, and 2.25 g N per pot); and sunn hemp or millet as green manure. The additions of N and P by the GM were taken into account. After grain physiologic maturation, corn dry matter, P contents, accumulated P, and P recovery in the different treatments were measured. P-32-TSP recovery by corn increased with N increasing rates, and decreased with increasing rates of P-32-TSP. The mineral fertilizer provides most of the accumulated P by corn plants. The recovery of P-32-TSP by corn was 13.12% in average. The green manure species influence the assimilation of P-32-TSP by the plants.

Synthesis of carbon nanomaterials from corn waste (DDGS)

Syntesis of carbon nanomaterials from corn waste (DDGS). The world's largest ethanol producer (USA) uses corn as feedstock. DDGS (distillers dried grains with solubles) is the main waste generated from this process (around 32 million t/year). DDGS samples were pyrolyzed at 1000 degrees C in a furnace with controlled atmosphere. The effluent was channeled to a second furnace, in which catalyst substrates were placed. Chromatographic analysis was used to evaluate the gaseous effluents, showing that the catalyst reduced hydrocarbon emissions. The solid products formed were analyzed by SEM and TEM. Graphitic structures and carbon nanofibers, 50 mu m in length and with diameters of 80-200 nm, were formed.

Direct Access to Oxidation-Resistant Nickel Catalysts through an Organometallic Precursor

The synthesis of nickel catalysts for industrial applications is relatively simple; however, nickel oxidation is usually difficult to avoid, which makes it challenging to optimize catalytic activities, metal loadings, and high-temperature activation steps. A robust, oxidation-resistant and very active nickel catalyst was prepared by controlled decomposition of the organometallic precursor [bis(1,5-cyclooctadiene)nickel(0)], Ni(COD)(2), over silica-coated magnetite (Fe3O4@SiO2). The sample is mostly Ni(0), and surface oxidized species formed after exposure to air are easily reduced in situ during hydrogenation of cyclohexene under mild conditions recovering the initial activity. This unique behavior may benefit several other reactions that are likely to proceed via Ni heterogeneous catalysis.

Fall Armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), Female Moths Respond to Herbivore-Induced Corn Volatiles

In response to herbivore attack, plants release herbivore-induced plant volatiles (HIPVs) that represent important chemical cues for herbivore natural enemies. Additionally, HIPVs have been shown to mediate other ecological interactions with herbivores. Differently from natural enemies that are generally attracted to HIPVs, herbivores can be either attracted or repelled depending on several biological and ecological parameters. Our study aimed to assess the olfactory response of fall armyworm-mated female moths toward odors released by mechanically and herbivore-induced corn at different time intervals. Results showed that female moths strongly respond to corn volatiles, although fresh damaged corn odors (0-1 h) are not recognized by moths. Moreover, females preferred volatiles released by undamaged plant over herbivore-induced plants at 5-6 h. This preference for undamaged plants may reflect an adaptive strategy of moths to avoid competitors and natural enemies for their offspring. We discussed our results based on knowledge about corn volatile release pattern and raise possible explanations for fall armyworm moth behavior.

Treatment-resistant depression increases health costs and resource utilization

Objective: Major Depressive Disorder (MDD) is a debilitating condition with a marked social impact. The impact of MDD and Treatment-Resistant Depression (TRD+) within the Brazilian health system is largely unknown. The goal of this study was to compare resource utilization and costs of care for treatment-resistant MDD relative to non-treatment-resistant depression (TRD-). Methods: We retrospectively analyzed the records of 212 patients who had been diagnosed with MDD according to the ICD-10 criteria. Specific criteria were used to identify patients with TRD+. Resource utilization was estimated, and the consumption of medication was annualized. We obtained information on medical visits, procedures, hospitalizations, emergency department visits and medication use related or not to MDD. Results: The sample consisted of 90 TRD+ and 122 TRD-patients. TRD+ patients used significantly more resources from the psychiatric service, but not from non-psychiatric clinics, compared to TRD-patients. Furthermore, TRD+ patients were significantly more likely to require hospitalizations. Overall, TRD+ patients imposed significantly higher (81.5%) annual costs compared to TRD-patients (R$ 5,520.85; US$ 3,075.34 vs. R$ 3,042.14; US$ 1,694.60). These findings demonstrate the burden of MDD, and especially of TRD+ patients, to the tertiary public health system. Our study should raise awareness of the impact of TRD+ and should be considered by policy makers when implementing public mental health initiatives.

A new drought resistant gymnosperm taxon Duartenia araripensis gen. nov et sp nov (Cheirolepidiaceae?) from the Early Cretaceous of Northern Gondwana

A new gymnosperm taxon from the Lower Cretaceous (upper Aptian to possibly lower Albian) Crato Formation of Brazil, Duartenia araripensis gen. nov. et sp. nov. is described. The most prominent specimen, a branch with attached lateral branches of higher orders exhibits a distinct anisotomous branching pattern. The very dense wood is composed of tracheids with spaced and partly contiguous uniseriate pits and low rays with one pit per cross-field (mixed protopinaceous type). When foliage is not abraded, Duartenia exhibits coriacious Brachyphyllum-type leaves. Duartenia may be linked to cheirolepid conifers, however, the systematic affinity remains uncertain. The dense wood, characteristic growth pattern and thick, scale like, trichome bearing leaves may be related to ecological conditions that reflect a seasonally dry climate.