The Role of irrigation techiniques in Cd bioaccumulation in rice (<i>Oryza sativa L.</i>)

The bioaccumulation of toxic elements in rice is of great concern worldwide because rice is the staple food for billions of people. The uptake of toxic elements (like As, Cd and Pb) in rice comes mainly from their interaction with system soil/water, and the reducing conditions typical of paddy fields play often a decisive role in the mobilization of specific chemical forms of these elements. Our results demonstrate that sprinkling irrigation may be an alternative and promising method in order to produce rice containing low amounts of toxic elements in kernels

Eficacia de plaguicidas sobre larvas de <i>Capnodis tenebrionis</i> (L.)

Se determina la eficacia de algunos plaguicidas sobre larvas recién nacidas de Capnodis tenebrionis (L.) en ensayos de laboratorio. Se utilisaron algunos productos comerciales que contenían isofenfos+foxim, clorpirifos, diazinon y carbaril. Las formulaciones más tóxicas eran las que contenían clorpirifos y isofenfos+foxim que causaron una mortandad media de 83.3 y 76.2% respectivamente. El análisis de los datos reveló que el efecto residual tenía una influencia significativa en mortandad de las larvas, mientras que las diversas dosis empleada en los ensayos no afectaron la mortandad de un modo significativo

Phenotyping of durum wheat (<i>Triticum turgidum</i> L. <i>subsp. durum</i>) development in a recombinant inbred line population

A good phenotyping of a key trait for adaptability and productivity like development is an essential pre-requisite for an integrate approach to breeding embracing physiology, molecular biology and modeling. A RIL population was grown in pots under three treatments: vernalized plants developing under long days, vernalized plants developing under short days and unvernalized plants developing under long days. Measured traits included: time to terminal spikelet, flag leaf and anthesis, final leaf number and phyllochron, number of spikelets per spike, rate and duration of tillering, maximum tiller number. The results were organized in three chapters. The first two chapters analyzed the genotypic variability in pre-anthesis phases, tillering capacity and spikelet number of durum wheat as affected by vernalization, photoperiod and earliness per se. In the third chapter the development of a sub-set of RILs was modeled by SiriusQuality2. The experimental approach utilized resulted in an accurate phenotyping and allowed to clearly distinguish between the effects of earliness per se, vernalization and photoperiod on the analyzed traits, and also to associate to each RIL a quantitative index describing its earliness per se, photoperiodic sensitivity and cold requirement. These indexes were strongly associated with the varietal parameters of the model, which was able to reproduce the phenotypic variability observed between RILs within environments

A Friendly Complexing Agent for Spectrophotometric Determination of Total Iron

Iron, one of the most common metals in the environment, plays a fundamental role in many biological as well as biogeochemical processes, which determine its availability in different oxidation states. Its relevance in environmental and industrial chemistry, human physiology, and many other fields has made it necessary to develop and optimize analysis techniques for accurate determination. Spectrophotometric methods are the most frequently applied in the analytical determination of iron in real samples. Taking advantage of the fact that desferrioxamine B, a trihydroxamic acid used since the 1970s in chelation therapy for iron overload treatment, forms a single stable 1:1 complex with iron in whichever oxidation state it can be found, a smart spectrophotometric method for the analytical determination of iron concentration was developed. In particular, the full compliance with the Lambert-Beer law, the range of iron concentration, the influence of pH, and the interference of other metal ions have been taken into account. The proposed method was validated in terms of LoD, LoQ, linearity, precision, and trueness, and has been applied for total iron determination in natural water certified material and in biological reference materials such as control human urine and control serum

Genetic variation for the duration of pre-anthesis development in durum wheat and its interaction with vernalization treatment and photoperiod

A recombinant inbred durum wheat population was grown under three contrasting regimes: long days following vernalization (LDV), long days without vernalization (LD), and short days following vernalization (SDV). The length of several pre-anthesis stages and the number of leaves and the phyllochron were measured. Different groups of genes were involved in determining the phenology in the three treatments, as demonstrated by a quantitative trait locus (QTL) analysis. The length of the period required to reach the terminal spikelet stage was correlated with the time to anthesis only in the case of LDV- and LD-grown plants where the timing of anthesis depended on the final leaf number. However, for SDV-grown plants, anthesis date was more dependent on the length of the period between the terminal spikelet stage and anthesis and was independent of leaf number. The involvement of the phyllochron in determining the duration of pre-anthesis development was also treatment-dependent. QTL mapping of the various flowering time associated traits uncovered some novel loci (such as those associated with the phyllochron), in addition to confirming the presence of several well-established loci

Chelating Agents in Soil Remediation: A New Method for a Pragmatic Choice of the Right Chelator

Soil pollution by metal ions constitutes one of the most significant environmental problems in the world, being the ecosystems of extended areas wholly compromised. The remediation of soils is an impelling necessity, and different methodologies are used and studied for reaching this goal. Among them, the application of chelating agents is one of the most promising since it could allow the removal of metal ions while preserving the most meaningful properties of the original soils. The research in this field requires the joined contribute of different expertise spanning from biology to chemistry. In this work, we propose a parsimonious and pragmatic approach for screening among a range of potential chelating agents. This methodology, the Nurchi's method, is based on an extension of the Reilley procedure for EDTA titrations. This allows forecasting the binding ability of chelating agents toward the target polluting metal ions and those typically found in soils, based on the knowledge of the related protonation and complex formation constants. The method is thoroughly developed, and then tested by application to some representative cases. Its use and relevance in biomedical and industrial applications is also discussed

Sorption of ofloxacin and chrysoidine by grape stalk. A representative case of biomass removal of emerging pollutants from wastewater

Emerging pollutants, as antibiotics or dyes, in aquatic ecosystems are a crucial concern and numerous techniques have been developed for their removal. Efficiency, cost effectiveness, and biodegradability reveal biomass sorption as one of the most appealing methods. This study aims to evaluate the effectiveness of grape stalk as a sorbent for ofloxacin (a fluoroquinolone antibiotic) and chrysoidine (an azo-dye). The kinetic and the thermodynamic aspects of the sorption were studied. A pseudo first-order kinetic behavior is shown by both substances, though the kinetic constants of ofloxacin are almost double than those of chrysoidine. The sorption isotherms, which strictly follow the Langmuir model, show remarkable differences as a function of pH and of biomass size. The trend of Langmuir parameters, Qmax and K, as a function of pH and size, is discussed, and different binding mechanisms are proposed. Kinetic and thermodynamic parameters prefigure grape stalk as a potential biomass for scavenging toxic substances from wastewater

Performance of two potentiometric fluoride determination methods in hard dental tissue

A comparison between two ion selective electrode (ISE) potentiometric methods is reported for determining the amount of fluoride in hard dental tissue after placement of fluoride-releasing dental restorations. The two methods are: (1) the direct method involving linear calibration (LC), and (2) a spiking method involving multiple standard additions (MA). Results showed that measurements performed by the LC method underestimate the amount of fluoride released by up to 30%. Recovery tests demonstrated that the use of MA and blank correction procedures is useful for an accurate and sensitive ISE determination of fluoride in hard dental tissues

A Speciation study on the perturbing effects of iron chelators on the homeostasis of essential metal ions

A number of reports have appeared in literature calling attention to the depletion of essential metal ions during chelation therapy on β-thalassaemia patients. We present a speciation study to determine how the iron chelators used in therapy interfere with the homeostatic equilibria of essential metal ions. This work includes a thorough analysis of the pharmacokinetic properties of the chelating agents currently in clinical use, of the amounts of iron, copper and zinc available in plasma for chelation, and of all the implied complex formation constants. The results of the study show that a significant amount of essential metal ions is complexed whenever the chelating agent concentration exceeds the amount necessary to coordinate all disposable iron —a frequently occurring situation during chelation therapy. On the contrary, copper and zinc do not interfere with iron chelation, except for a possible influence of copper on iron speciation during deferiprone treatment

Sorption of chrysoidine by row cork and cork entrapped in calcium alginate beads

Abstract Azo-dyes, molecules characterised by the presence of the azo-group (–N N–), are widely used in textile, leather, rubber, plastic, and food industries. Water-soluble azo-dyes are greatly resistant to biodegradation, and are characterised by a high thermal and photo stability due to their complex structures. The release of these molecules into the environment is of crucial concern due to their toxic, mutagenic and carcinogenic characteristics. Biosorption has been demonstrated an effective method to remove pollutants from wastewaters thus solving ecological tasks, being a low cost process and the sorbent biodegradable. The main requirements of an efficient sorbent are thermal, chemical and mechanical stability, and rapid sorption. In this work, the ability of both row cork and the same sorbent entrapped in a biopolymeric gel of calcium alginate, on the removal of chrysoidine from aqueous solutions was examined. The influence on the sorption of pH, initial dye concentration, and particle size, as well as the efficiency of the entrapment, have been investigated. The maximum sorption was found for cork samples of fine particle size (FC), in both row and entrapped forms, at pH 7; conversely, at pH 4 the difference is significant (0.12 mmol/g for row cork and 0.20 mmol/g for entrapped cork), evoking a cooperation of alginate in binding the positively charged chrysoidine molecule