Evaluation of in Situ DGT Measurements for Predicting the Concentration of Cd in Chinese Field-Cultivated Rice: Impact of Soil Cd:Zn Ratios

DGT (diffusive gradients in thin-films) has been proposed as a tool for predicting Cd concentrations in rice grain, but there is a lack of authenticating data. To further explore the relationship between DGT measured Cd and concentrations in rice cultivated in challenging, metal degraded, field locations with different heavy metal pollutant sources, 77 paired soil and grain samples were collected in Southern China from industrial zones, a "cancer village" impacted by mining waste and an organic farm. In situ deployments of DGT in flooded paddy rice rhizospheres were compared with a laboratory DGT assay on dried and rewetted soil. Total soil concentrations were a very poor predictor of plant uptake. Laboratory and field deployed DGT assays and porewater measurements were linearly related to grain concentrations in all but the most contaminated samples where plant toxicity occurred. The laboratory DGT assay was the best predictor of grain Cd concentrations, accommodating differences in soil Cd, pollutant source, and Cd:Zn ratios. Field DGT measurements showed that Zn availability in the flooded rice rhizospheres was greatly diminished compared to that of Cd, resulting in very high Cd:Zn ratios (0.1) compared to commonly observed values (0.005). These results demonstrate the potential of the DGT technique to predict Cd concentrations in field cultivated rice and demonstrate its robustness in a range of environments. Although, field deployments provided important details about in situ element stoichiometry, due to the inherent heterogeneity of the rice rhizosphere soils, deployment of DGT in dried and homogenized soils offers the best possibility of a soil screening tool.

Finding Your Feet in the Field: Critical Reflections of Early Career Researchers on Field Research in Transitional Societies

Fieldwork that takes place in conflict or transitional regions is becoming increasingly popular amongst early-career and more seasoned researchers, but is an area that retains an air of mystery and remains an exotic form of knowledge gathering. There exists a paucity of personal reflection on the challenges associated with conducting fieldwork in conflicted or transitional regions and a limited amount of insight into the practical steps taken in advance of and when immersed in the field. Such reticence to share honest fieldwork experiences, particularly the more challenging research that takes place in conflict or transitional settings aids in creating a culture of silence. This paper attempts to counteract this silence by drawing on the challenges experienced by two early career researchers conducting fieldwork in Uganda and Palestine, focusing on the practical steps taken in advance of entering the field, and the challenges faced whilst engaged in fieldwork. Specific challenges are highlighted throughout, including: physical access to areas in conflict; engaging with reluctant research participants; the emotional impact of fieldwork on the researcher; maintaining confidentiality; researching with vulnerable victims; and ensuring appropriate knowledge exchange between researchers and participants. The paper concludes by emphasising the requirement for greater reflection on the inherently personal challenges associated with conducting fieldwork in conflicted or transitional settings and highlights the view that fieldwork is a privileged position that carries great responsibilities which must be upheld to ensure the sustainability of future research. This paper hopes to contribute to the wider debate on conducting fieldwork and the challenges associated with working in conflicted or transitional regions.

Identification of the Dynamic Parameters of a Real Bridge under Different Damage Conditions in a Field Experiment

This paper presents the results of a real bridge field experiment in which damage was applied artificially to a steel truss bridge. The aim of this paper is to identify the dynamic parameters of this bridge using conventional techniques and investigate the effect of various damage conditions on those parameters. In the field experiment, acceleration measurements were recorded at a number of locations on the bridge deck. To excite the bridge, a two-axle van was driven across the bridge at constant speed. Dynamic parameters, such as the bridge mode shape, natural frequency and damping constant, are identified from the acceleration signals using existing techniques such as the fast Fourier transform, logarithmic decrement and frequency domain decomposition. The variation of these parameters under the influence of artificially applied damage conditions is investigated in order to evaluate their sensitivity to the bridge damage.

On Being Let Loose in the Field: The Execution of Professional Ethics

In recent years concerns over litigation and the trend towards close monitoring of academic activity has seen the effective hijacking of research ethics by university managers and bureaucrats. This can effectively curtail cutting edge research as perceived ‘safe’ research strategies are encouraged. However, ethics is about more than research governance. Ultimately, it seeks to avoid harm and to increase benefits to society. Rural development debate is fairly quiet on the question of ethics, leaving guidance to professional bodies. This study draws on empirical research that examined the lives of migrant communities in Northern Ireland. This context of increasingly diverse rural development actors provides a backdrop for the way in which the researcher navigates through ethical issues as they unfold in the field. The analysis seeks to relocate ethics from being an annoying bureaucratic requirement to one where it is inherent to rigorous and professional research and practice. It reveals how attention to professional ethics can contribute to effective, situated and reflexive practice, thus transforming ethics to become an asset to professional researchers.

Electron rescattering in strong-field photodetachment of F-

We present ab initio studies of photoelectron spectra for above threshold detachment (ATD) of F- anions in short, 1300 nm and 1800 nm laser pulses. We identify and assess the importance of electron rescattering in strong-field photodetachment of a negative ion through comparison with an analytic, Keldysh-type approach, demonstrating the capability of ab-initio computation in the challenging near-IR regime. We further assess the influence of the strong electron correlation on the photodetachment.

Low alanine aminotransferase levels and higher number of cardiovascular events in people with Type 2 diabetes: analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

AIMS: To determine whether alanine aminotransferase or gamma-glutamyltransferase levels, as markers of liver health and non-alcoholic fatty liver disease, might predict cardiovascular events in people with Type 2 diabetes.

METHODS: Data from the Fenofibrate Intervention and Event Lowering in Diabetes study were analysed to examine the relationship between liver enzymes and incident cardiovascular events (non-fatal myocardial infarction, stroke, coronary and other cardiovascular death, coronary or carotid revascularization) over 5 years.

RESULTS: Alanine aminotransferase level had a linear inverse relationship with the first cardiovascular event occurring in participants during the study period. After adjustment, for every 1 sd higher baseline alanine aminotransferase value (13.2 U/l), the risk of a cardiovascular event was 7% lower (95% CI 4-13; P=0.02). Participants with alanine aminotransferase levels below and above the reference range 8-41 U/l for women and 9-59 U/l for men, had hazard ratios for a cardiovascular event of 1.86 (95% CI 1.12-3.09) and 0.65 (95% CI 0.49-0.87), respectively (P=0.001). No relationship was found for gamma-glutamyltransferase.

CONCLUSIONS: The data may indicate that in people with Type 2 diabetes, which is associated with higher alanine aminotransferase levels because of prevalent non-alcoholic fatty liver disease, a low alanine aminotransferase level is a marker of hepatic or systemic frailty rather than health. This article is protected by copyright. All rights reserved.

Geographical variation in inorganic arsenic in paddy field samples and commercial rice from the Iberian Peninsula

This study investigated total arsenic and arsenic speciation in rice using ion chromatography with mass spectrometric detection (IC-ICP-MS), covering the main rice-growing regions of the Iberian Peninsula in Europe. The main arsenic species found were inorganic and dimethylarsinic acid. Samples surveyed were soil, shoots and field-collected rice grain. From this information soil to plant arsenic transfer was investigated plus the distribution of arsenic in rice across the geographical regions of Spain and Portugal. Commercial polished rice was also obtained from each region and tested for arsenic speciation, showing a positive correlation with field-obtained rice grain. Commercial polished rice had the lowest i-As content in Andalucia, Murcia and Valencia while Extremadura had the highest concentrations. About 26% of commercial rice samples exceeded the permissible concentration
for infant food production as governed by the European Commission. Some cadmium data is also presented, available with ICP-MS analyses, and show low concentration in rice samples.