Effect of sewage sludge or compost on the sorption and distribution of cooper and cadmium in soil

The application of biosolids such as sewage sludge is a concern, because of the potential release of toxic metals after decomposition of the organic matter. The effect of application of sewage sludge (Sw) and compost (C) to the soil (S) on the Cu and Cd sorption, distribution and the quality of the dissolved organic matter (DOM) in the soil, was investigated under controlled conditions. Visible spectrophotometry, infrared spectroscopy, sorption isotherms (simple and competitive sorption systems), and sequential extraction methods were used. The E4/E6 (k at 465 and 665 nm) ratio and the infrared spectra (IR) of DOM showed an aromatic behaviour in compost–soil (C–S); in contrast sewage sludge–soil (Sw–S) showed an aliphatic behaviour. Application of either Sw or C increased the Cu sorption capacity of soil. The Cd sorption decreased only in soil with a competitive metal system. The availability of Cu was low due to its occurrence in the acid soluble fraction (F3). The Cu concentration varied in accordance with the amounts of Cu added. The highest Cd concentration was found in the exchangeable fraction (F2). The Sw and C applications did not increase the Cd availability in the soil

Effects of sewage sludge and sewage sludge compost amendment on soil properties and zea mays l. plants (heavy metals, quality and productivity)

The use of organic wastes in agriculture can improve the soil's productive capacity, and physical and chemical characteristics. This study evaluated the effects of sewage sludge, sewage sludge compost and inorganic fertilizer applications on nickel, copper and zinc contents in soil and corn grains (Zea mays L); maize productivity, and grain nutritional quality. Sewage sludge and sewage sludge compost at 18 Mg ha¿1 and a mineral fertilizer (N-P-K) with a formulation of 150-75-30 were applied. Significant differences were observed in organic matter, phosphorus and zinc content between sewage sludge-soil and compost-soil, and inorganic fertilizer-soil (P < 0.05). Copper concentration was significantly high in compost-soil (P < 0.05). Productivity in compost-soil and sewage sludge-soil mixtures was higher than in inorganic fertilizer-soil. Grain quality, measured by relative percentage of starch, total nitrogen, protein, acid detergent fiber and neutral detergent fiber were adequate for human consumption. Application of sewage sludge or compost did not increase heavy metal concentrations in grain with respect to inorganic fertilizer-soil

Biosynthesis of Silver Nanoparticles Using Chenopodium ambrosioides

Biosynthesis of silver nanoparticles (AgNPs) was achieved using extract of Chenopodium ambrosioides as a reducer and coating agent at room temperature (25°C). Two molar solutions of AgNO3 (1 mM and 10 mM) and five extract volumes (0.5, 1, 2, 3, and 5 mL) were used to assess quantity, shape, and size of the particles. The UV-Vis spectra gave surface plasmon resonance at 434–436 nm of the NPs synthesized with AgNO3 10 mM and all extract volumes tested, showing a direct relationship between extract volumes and quantity of particles formed. In contrast, the concentration of silver ions was related negatively to particle size. The smallest (4.9 ± 3.4 nm) particles were obtained with 1 mL of extract in AgNO3 10 mM and the larger amount of particles were obtained with 2 mL and 5 mL of extract. TEM study indicated that the particles were polycrystalline and randomly oriented with a silver structure face centered cubic (fcc) and fourier transform infrared spectroscopy (FTIR) indicated that disappearance of the –OH group band after bioreduction evidences its role in reducing silver ions

Biosynthesis of silver nanoparticles using chenopodium ambrosioides

ARTICULO INDEXADOBiosynthesis of silver nanoparticles (AgNPs) was achieved using extract of Chenopodium ambrosioides as a reducer and coating agent at room temperature (25∘C). Two molar solutions of AgNO3 (1 mM and 10 mM) and fie extract volumes (0.5, 1, 2, 3, and 5 mL) were used to assess quantity, shape, and size of the particles. Th UV-Vis spectra gave surface plasmon resonance at 434– 436 nm of the NPs synthesized with AgNO3 10 mM and all extract volumes tested, showing a direct relationship between extract volumes and quantity of particles formed. In contrast, the concentration of silver ions was related negatively to particle size. Th smallest (4.9 ± 3.4 nm) particles were obtained with 1 mL of extract in AgNO3 10 mM and the larger amount of particles were obtained with 2 mL and 5 mL of extract. TEM study indicated that the particles were polycrystalline and randomly oriented with a silver structure face centered cubic (fcc) and fourier transform infrared spectroscopy (FTIR) indicated that disappearance of the –OH group band aftr bioreduction evidences its role in reducing silver ions.CCIQS; “Fideicomiso Revocable y de Administracion no. 157304´ COLPOS” and the L´ınea de Investigacion Prioritaria LPI-16´ “Innovacion Tecnol´ ogica” at the “Colegio de Postgraduados´ COLPOS

Extrafloral nectaries in Opuntia robusta

Descubrimos la existencia de nectáreos extraflorales en Opuntia robustaTo our knowledge, there are no studies about the structure and ecological function of extra- floral nectaries (EFNs) in Opuntia robusta. This is the first description of EFNs in O. robusta, where young spines have an interesting structure and a secreting function, which are differ- ent from EFNs described in other Cactaceae species. We used light, scanning-electron, and transmission-electron microscopy to examine morphology, anatomy, and ultrastructure of the secretory spines in areoles in female and hermaphrodite individuals of O. robusta. Young cladodes develop areoles with modified and secretory spines as EFNs only active during the early growth phase. EFNs are non-vascularized structures, with no stomata, that consist of a basal meristematic tissue, a middle elongation region, and an apical secretory cone formed by large globular epidermal cells, containing nectar and medullar elongated cells. We observed the presence of Golgi apparatus, vesicles and plastids in the medullar and sup-epidermal cells of the spine. We propose that the nectar is stored in the globular cells at the apex of the spine and secreted by breaking through the globular cells or by pores. We recorded a more frequent presence of ants on younger cladode sprouts producing young secreting spines: this result is parallel with the predictions of Optimal Defense Hypothesis, which states that younger plant organs should be better defended than older ones because their loss produces a higher fitness impairment. Although Diaz-Castelazo’s hypothesis states that a more complex structure of EFNs correlates with their lower among-organs dispersion, comparing to less complex EFNs, non-vascularized structure of EFNs in O. robusta is not associated with their higher among-organs dispersion likened to O. stricta, which produces vascularized EFNs. We provide evidence that this characteristic is not a good taxonomic fea- ture of Opuntia genus. Moreover, the comparison of EFNs of O. robusta and O. stricta sug- gests that the hypothesis of Diaz-Castelazo should be revised: it is rather a rule but not a law.CONACyT 180694/201

Study of the Performance of the Organic Extracts of Chenopodium ambrosioides

There are many ways to obtain metal nanoparticles: biological, physical, and chemical ways and combinations of these approaches. Synthesis assisted with plant extracts has been widely documented. However, one issue that is under discussion refers to the metabolites responsible for reduction and stabilization that confine nanoparticle growth and prevent coalescence between nanoparticles in order to avoid agglomeration/precipitation. In this study, Ag nanoparticles were synthesized using organic extracts of Chenopodium ambrosioides with different polarities (hexane, dichloromethane, and methanol). Each extract was phytochemically characterized to identify the nature of the metabolites responsible for nanoparticle formation. With methanol extract, the compounds responsible for reducing and stabilizing silver nanoparticle were associated with the presence of phenolic compounds (flavonoids and tannins), while, with dichloromethane and hexane extracts, the responsible compounds were mainly terpenoids. Large part of the reducing activity of secondary metabolites in C. ambrosioides is closely related to compounds with antioxidant capacity, such as phenolic compounds (flavone glycoside and isorhamnetin), which are the main constituents of the methanol extracts. Otherwise, terpenoids (trans-diol, α-terpineol, monoterpene hydroperoxides, and apiole) are the central metabolites present in dichloromethane and hexane extracts

Bulletin of British earthquakes 2015

"To our knowledge, there are no studies about the structure and ecological function of extrafloral nectaries (EFNs) in Opuntia robusta. This is the first description of EFNs in O. robusta, where young spines have an interesting structure and a secreting function, which are different from EFNs described in other Cactaceae species. We used light, scanning-electron, and transmission-electron microscopy to examine morphology, anatomy, and ultrastructure of the secretory spines in areoles in female and hermaphrodite individuals of O. robusta. Young cladodes develop areoles with modified and secretory spines as EFNs only active during the early growth phase. EFNs are non-vascularized structures, with no stomata, that consist of a basal meristematic tissue, a middle elongation region, and an apical secretory cone formed by large globular epidermal cells, containing nectar and medullar elongated cells. We observed the presence of Golgi apparatus, vesicles and plastids in the medullar and sup-epidermal cells of the spine. We propose that the nectar is stored in the globular cells at the apex of the spine and secreted by breaking through the globular cells or by pores. We recorded a more frequent presence of ants on younger cladode sprouts producing young secreting spines: this result is parallel with the predictions of Optimal Defense Hypothesis, which states that younger plant organs should be better defended than older ones because their loss produces a higher fitness impairment. Although Diaz-Castelazo’s hypothesis states that a more complex structure of EFNs correlates with their lower among-organs dispersion, comparing to less complex EFNs, non-vascularized structure of EFNs in O. robusta is not associated with their higher among-organs dispersion likened to O. stricta, which produces vascularized EFNs. We provide evidence that this characteristic is not a good taxonomic feature of Opuntia genus. Moreover, the comparison of EFNs of O. robusta and O. stricta suggests that the hypothesis of Diaz-Castelazo should be revised: it is rather a rule but not a law.

Designing and evaluation of sodium selenite nanoparticles in vitro to improve selenium absorption in ruminants

Sodium selenite is used to prevent selenium deficiency known as nutritional muscular dystrophy or white muscle disease. In ruminants, selenium supplements are transformed partiality in insoluble form by ruminal microorganisms and its process decrease the selenium absorption in digestive gastrointestinal. However, the objective in this research was focused in encapsulated sodium selenite to be release into of a pH less than four, similarity to an intestinal environment. It was encapsulated by nanoprecipitation and emulsion–evaporation methods, within polymeric nanoparticles. The effect of these methods, polymer proportion (Eudragit RL and RS) and solvent (ethanol and acetone) on the physicochemical (drug entrapment, polidispersity index (PDI) and z potential) and morphological characteristics (particle morphology and particle size) were evaluated. Particle size from each nanoparticles, formulation ranged from 36.64 to 213.86 nm. Particle size, z potential and PDI increased (P ≤ 0.01) when nanoprecipitation and ethanol were used. No significant differences (P > 0.05) were observed when different polymeric proportions were used. Selenium entrapment was 26% when emulsion–evaporation method was used and 78% with nanoprecipitation. Nanoparticles produced by nanoprecipitation were spherical and had a great variation in particle size; on the other hand, nanoparticles produced by emulsion–evaporation were spherical as well as amorphous and presented a homogeneous nanopartcicle size distribution. The release of selenium from nanoparticles was higher in acid pH (less than 4), this condition may represent a better availability of the mineral in the small intestine

Proteomic changes associated with expression of a gene (ipt) controlling cytokinin synthesis for improving heat tolerance in a perennial grass species

Cytokinins (CKs) are known to regulate leaf senescence and affect heat tolerance, but mechanisms underlying CK regulation of heat tolerance are not well understood. A comprehensive proteomic study was conducted to identify proteins altered by the expression of the adenine isopentenyl transferase (ipt) gene controlling CK synthesis and associated with heat tolerance in transgenic plants for a C3 perennial grass species, Agrostis stolonifera. Transgenic plants with two different inducible promoters (SAG12 and HSP18) and a null transformant (NT) containing the vector without ipt were exposed to 20 °C (control) or 35 °C (heat stress) in growth chambers. Two-dimensional electrophoresis and mass spectrometry analysis were performed to identify protein changes in leaves and roots in response to ipt expression under heat stress. Transformation with ipt resulted in protein changes in leaves and roots involved in multiple functions, particularly in energy metabolism, protein destination and storage, and stress defence. The abundance levels of six leaf proteins (enolase, oxygen-evolving enhancer protein 2, putative oxygen-evolving complex, Rubisco small subunit, Hsp90, and glycolate oxidase) and nine root proteins (Fd-GOGAT, nucleotide-sugar dehydratase, NAD-dependent isocitrate dehydrogenase, ferredoxin-NADP reductase precursor, putative heterogeneous nuclear ribonucleoprotein A2, ascorbate peroxidase, dDTP-glucose 4–6-dehydratases-like protein, and two unknown proteins) were maintained or increased in at least one ipt transgenic line under heat stress. The diversity of proteins altered in transgenic plants in response to heat stress suggests a regulatory role for CKs in various metabolic pathways associated with heat tolerance in C3 perennial grass species