Effect of repeated atrazine and pendimethalin application on their bound residues in long term fertilized soil of semi-arid tropic region in India

Repeated and long term application of same herbicides forms bound residues in soil and becomes point source of pollution over a period of time and harms the soil microorganisms. Among the different herbicides, the atrazine and pendimethalin is widely and repeatedly used molecule in maize and sunflower cultivation for weed control, respectively. Hence the present study was undertaken to investigate the bound residue of the applied herbicides in soil under long term fertilized condition with varied nutrient sources since 1909 in North-Western agro-climatic zone of Tamil Nadu under the semi-arid tropic region of India. Soil samples were collected at the time of maize and sunflower harvest and analysed for the bound fraction of atrazine and pendimethalin compounds respectively. The results showed that the repeated application of these herbicides at recommended dose formed a considerable amount of non-extractable bound residues in soil. While the bound fraction of parent atrazine was found below detectable limit, pendimethalin was at a quantifiable level in the soil irrespective of fertilization sources. However the bound form of atrazine metabolites, namely Des ethyl Deisopropyl atrazine (DEDIA) and Hydroxy atrazine (HA) was extracted from the maize cultivated soil. Bound forms of HA (4.34%) and DEDIA (3.43%) and pendimethalin (3.14%)to the applied quantity were witnessed at a higher amount in control plot than the fertilized plots. The omission of any one major nutrient recorded elevated DEDIA bound form than the HA fraction. The non-extractable bound residues of both the herbicides were detected at different proportions according to the herbicide nature, sources of fertilization and the crops cultivated in the soil. The fraction of bound form of atrazine metabolites was detected at higher level than the pendimethalin in soil. The present study revealed that the bound residues of atrazine, its metabolites and pendimethalin can be mineralized into the soil solution and bio-augmented over a period of time under the conditions of repeated application. Hence the remobilization of bound residues of these herbicides must be considered while gauging the environmental hazard and effect on non-target organisms.

How to get your goat: automated identification of species from MALDI-ToF spectra

Motivation Classification of archaeological animal samples is commonly achieved via manual examination of matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) spectra. This is a time-consuming process which requires significant training and which does not produce a measure of confidence in the classification. We present a new, automated method for arriving at a classification of a MALDI-ToF sample, provided the collagen sequences for each candidate species are available. The approach derives a set of peptide masses from the sequence data for comparison with the sample data, which is carried out by cross-correlation. A novel way of combining evidence from multiple marker peptides is used to interpret the raw alignments and arrive at a classification with an associated confidence measure. Results To illustrate the efficacy of the approach, we tested the new method with a previously published classification of parchment folia from a copy of the Gospel of Luke, produced around 1120 C.E. by scribes at St Augustine’s Abbey in Canterbury, UK. In total, 80 of the 81 samples were given identical classifications by both methods. In addition, the new method gives a quantifiable level of confidence in each classification. Availability and implementation The software can be found at https://github.com/bioarch-sjh/bacollite, and can be installed in R using devtools. Supplementary information Supplementary data are available at Bioinformatics online.

A patient-centred model to quality assure outputs from an echocardiography department: consensus guidance from the British Society of Echocardiography

BackgroundQuality assurance (QA) of echocardiographic studies is vital to ensure that clinicians can act on findings of high quality to deliver excellent patient care. To date, there is a paucity of published guidance on how to perform this QA. The British Society of Echocardiography (BSE) has previously produced an Echocardiography Quality Framework (EQF) to assist departments with their QA processes. This article expands on the EQF with a structured yet versatile approach on how to analyse echocardiographic departments to ensure high-quality standards are met. In addition, a process is detailed for departments that are seeking to demonstrate to external bodies adherence to a robust QA process.MethodsThe EQF consists of four domains. These include assessment of Echo Quality (including study acquisition and report generation); Reproducibility & Consistency (including analysis of individual variability when compared to the group and focused clinical audit), Education & Training (for all providers and service users) and Customer & Staff Satisfaction (of both service users and patients/their carers). Examples of what could be done in each of these areas are presented. Furthermore, evidence of participation in each domain is categorised against a red, amber or green rating: with an amber or green rating signifying that a quantifiable level of engagement in that aspect of QA has been achieved.ConclusionThe proposed EQF is a powerful tool that focuses the limited time available for departmental QA on areas of practice where a change in patient experience or outcome is most likely to occur.

Gas-Liquid Chromatographic Method for Determining 1,4-Dioxane in Cosmetics

A gas-liquid chromatographic procedure has been developed for the quantitation of 1,4-dioxane in various cosmetic products including lotions, cleansers, skin creams, make-ups, and shampoos. The impurity is extracted into an aqueous phase followed by column cleanup to remove nonpolar interferents. 1,4-Dioxane is partitioned into toluene, passed through an extraction tube to remove water and other polar compounds including organic dyes, concentrated by adsorption onto silica, further purified by washing with dichloromethane, and eluted with acetonitrile for injection into the gas chromatograph. The mean recovery of 1,4-dioxane from 51 cosmetic products, determined by spiking, was 63%. The limit of detectability is about 0.5 ppm and the minimum quantifiable level is about 2 ppm. The identity of 1,4-dioxane is confirmed by mass spectrometry.

Determination of Background Levels of Lead and Cadmium in Raw Agricultural Crops by Using Differential Pulse Anodic Stripping Voltammetry

A method is described for the simultaneous determination of ultratrace levels of lead and cadmium in selected agricultural crop samples by differential pulse anodic stripping voltammetry. Samples are dry ashed at high temperature with H2SO4 as an ashing aid. Techniques are described to control the lead and cadmium blank levels of 2 ng and 0.4 ng, respectively. Typical relative standard deviations for the crop analyses are 13% at 100 ng/g and 25% at 10 ng/g for lead, and 5% at 100 ng/g and 10% at 10 ng/g for cadmium. The lowest quantifiable level, based on 3 g dry sample, is 2 ng/g for lead and 1 ng/g for cadmium. Recovery studies, precision studies, and analyses of NBS Standard Reference Materials demonstrate the accuracy and reproducibility of this technique. A summary of results for over 1700 crop samples is reported.