The Influences of consumer attitudes and perceptions about pesticides and produce quality on technology transfer

Consumers have expressed concern about the human health and environmental consequences resulting from the use of agrichemicals by growers to produce food. This paper reports the results of a 1995 survey of consumer attitudes and perceptions about pesticides and fresh fruit and vegetable quality. While there is widespread concern about the human health hazards presented by pesticide residues in food at the time of consumption, this survey population reports greater consumer concern about environmental contamination from agrichemical use. Once familiar with the process of Integrated Pest Management (IPM), the respondents of this survey indicate they would prefer to purchase fruits and vegetables grown with IPM practices, would accept blemished fruits and vegetables in exchange for reduced chemical applications and would pay more for fruits and vegetables grown with fewer chemical applications. Additionally, the results of a partnership between local growers, a food retailer and a land-grant university with the goal of encouraging local growers to adopt IPM practices in fresh market production are presented. Results of an informal survey conducted in 1995 at a local grocery store document strong support for IPM once consumers understand the attributes of IPM. Recommendations for an IPM education program for employees and consumers are given

Letters from J. D. McLaren and W. J. Kerr

Letters concerning a position at Utah Agricultural College as well as a biography detailing John Dice McLaren\u27s qualifications

Associatively-mediated stopping: training stimulus-specific inhibitory control

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.Response inhibition is often considered to be a deliberate act of cognitive control. However, our and other research suggests that by repeatedly pairing stimuli with an inhibitory response, inhibition can become automatized. Currently, relatively little research has focused on the nature of the associative structure that underpins stimulus-specific inhibitory training. This paper investigated what associations can be learnt in stop-signal training tasks, distinguishing between indirect priming of the stop signal and direct activation of a stop response. We employed a novel paradigm, where colored cues are stochastically paired with a number of stop-signals, and demonstrated that cues consistently paired with stopping reduced commission errors and slowed reaction times. Furthermore, we showed that manipulating the pairings between stimuli and stop signals, in a manner that favored the formation of stimulus-stop associations, produced enhanced stop learning effects on reaction time, but not probability of responding. Our results suggest that perceptual processes supporting signal detection (priming) as well as inhibitory processes are involved in inhibitory control training, and that inhibition training may benefit from reducing the contingency between stimuli and stop-signals.Economic and Social Research CouncilER

Anaerobic Biodegradation of Petroleum Hydrocarbons in Powdered Activated Carbon Groundwater Systems: A Modelling Investigation

Subsurface contamination by petroleum hydrocarbons (PHCs) is a widespread issue resulting from oil and gas production, distribution, and use. As a result of improved injection methods and particulate materials, injected permeable reactive barriers (PRBs) have gained popularity as a remedial method to cut off groundwater plumes and protect downgradient receptors. The use of particulate activated carbon (AC) as an injected amendment has grown due to its proven capability to adsorb organic contaminants, including PHCs, and potential to enhance biodegradation rates. It has been suggested that AC particulate amendments can establish a dynamic equilibrium between adsorption, desorption, and destruction through biodegradation which prevents downgradient migration of PHC plumes indefinitely. The overarching goal of this research was to develop a modelling framework to simulate benzene, toluene, and o-xylene (BTX) sorption and biodegradation in bench-scale experimental systems containing powdered activated carbon (PAC) and to investigate if biodegradation was enhanced in the presence of PAC. A batch reactor model was developed to simulate non-linear, hysteretic and competitive sorption, and biodegradation representing the conditions of bioaugmentation culture vessels as well as a series of microcosm experiments. The microcosms contained aquifer solids and/or PAC and were subjected to different biological conditions (e.g., bioaugmentation cultures). All microcosms contained either a single compound (toluene) or multiple compounds (BTX). A one-dimensional (1D) reactive transport model was also developed which included the processes simulated in the batch reactor model and was deemed representative of an in situ PAC treatment zone. This permitted investigations into sorption hysteresis and PHC breakthrough, as well as exploratory scenarios examining the impact of contaminant mass loading and biodegradation kinetics on the performance of a hypothetical PAC treatment zone. Using an existing set of single and multi-compound isotherm parameters determined for the PAC used, the batch reactor model was able to simulate the steady-state aqueous BTX concentrations observed in microcosm experiments with no biodegradation. A comparison between simulated and observed solid phase concentrations for microcosms with PAC indicated that desorption hysteresis was minimal. The calibrated kinetic parameters showed improved biodegradation (higher maximum specific growth rate [μmax] and lower half velocity constant [KS]) for the compound with the highest sorption affinity compared to the bulk solution (toluene in single compound systems and o-xylene in multi-compound systems). 1D investigative scenarios demonstrated that differences in maximum specific growth rate and half-velocity constant (calibrated kinetic parameters for the PHCs) were the most influential factor affecting aqueous effluent PHC concentrations and cumulative PHC mass decayed, while BTX mass loading (a change in flow rate or influent concentration) had a minimal impact. A hypothetical scenario meant to represent biofilm formation on PAC where the maximum specific growth rate was an assumed function of biomass concentration significantly decreased effluent PHC concentrations and increased cumulative PHC mass decayed, suggesting that improved kinetics (i.e., higher maximum specific growth rates) resulting from biofilm formation may lead to more effective long-term PHC treatment. Overall, the batch reactor and 1D models were able to simulate complex single and multi-compound sorption in bench-scale systems with and without biodegradation. Additionally, there is evidence demonstrating that PAC improves the degradation of compounds with high sorption affinity relative to the bulk solution in a batch reactor system. While mass loading had minimal impact on treatment effectiveness in a column system, improved kinetics (i.e., lower half velocity constant and/or higher maximum specific growth rates, such as through the formation of a biofilm) lead to significant treatment. The developed and validated modelling framework can be used as a foundation for future models to aid in the design and data interpretation of field-scale AC particulate amendment PRBs involving PHCs and other organic contaminants

Associatively-mediated stopping: training stimulus-specific inhibitory control (dataset)

Behavioural data, R analysis scripts, and documentation for two behavioural experiments described in "Associatively-mediated stopping: training stimulus-specific inhibitory control". To be published in Learning & Behavior (2015). Available in ORE at: https://ore.exeter.ac.uk/repository/handle/10871/18061Behavioural data, R analysis scripts, and documentation for two behavioural experiments described in "Associatively-Mediated Stopping: Training Stimulus-Specific Inhibitory Control". To be published in Learning & Behavior (2015).ESRCER

Studies on the amino acid sequence of cytochrome c

The purpose of this work was to obtain information about the sequence of amino acid residues in the peptide chain of cytochrome c, and at the same time to study methods for obtaining ouch information. Cytochrome c Was isolated from horse heart d purified by chromatography on ion exchange resin (Amberlite IRC 50) and on sephadex. Attempts to identify the N-terminal amino acid residue yielded negative results, and it was concluded that the protein may not have a free terminal amino group. This was subsequently confirmed by Kreil and Tuppy who showed that the N-terminal group is acetylglycine. To investigate the internal sequence of the protein, cytochrome c was hydrolysed with trypsin to yield a mixture of peptides. Chromatography on carboxymethyl cellulose, brought about partial resolution of this mixture, and the application of high voltage paper electrophoresis permitted the isolation of some pure homogeneous peptides from the material thus obtained. These methods, however, seemed inadequate for the exhaustive analysis of the peptide mixture. An effort was made, therefore, to reduce the severity of the problem of peptide fractionation, by reducing the complexity of the mixture to be separated. This was achieved by acylating the lysine amino groups of cytochrome c, and thus restricting the action of trypsin to linkages involving the carbonyl groups of the two arginine residues in the protein. Methoxy-carboxyl chloride was firs tried as an acylating agent, but proved unsuitable. Ethyl thiotrifluoroacetate was satisfactory and, at pH 9, this ester reacted with all the amino groups of the protein. It was found also that the substituent trifluoroacetyl groups could subsequently be removed by means of 0.5 M ammonia, without affecting the peptide structure. The action of trypsin on the trifluoroacetyl protein yielded a mixture of peptides which was rather more complex the had been anticipated. On the assumption that this was due to the action of traces of chymotrypsin in the trypsin preparation the time of exposure to the protease was reduced, and it was eventually possible by means of chromatography on sephadex to isolate a small number of large peptides. The amino acid compositions of these peptides, and the nature of their N-terminal residues were determined. Also, one of them was hydrolysed with chymotrypsin, and the resulting mixture of small peptides fractionated on a column of ZeoKarb 225 x 2. The peptides thus separated were analysed and their sequence in the original peptide determined. The results of the analysis carried out during the course of this work were internally consistent, and in general found agreement with the recently published no acid sequence for cytochrome c

Anthropometric indicators in identifying malnutrition risk among children younger than two years in Motherwell, Nelson Mandela Metropolitan Municipality

Introduction: South Africa is burdened with a high prevalence of childhood malnutrition. The World Health Organisation (WHO) endorses weight for length (WFL) Z-scores and mid-upper arm circumference (MUAC) as tools for identifying children who are malnourished. The MUAC measurement offers many advantages for its use in community nutrition, and may aid in the early identification of malnourished children. More accurate and comprehensive data on child anthropometric status are needed in the Nelson Mandela Bay Health District (NMBHD), as well as assessment of the efficacy of using a simplified tool such as MUAC to screen for malnutrition. Aim: This study aimed to synthesise a profile of the nutritional status of children younger than two years old in Motherwell, Nelson Mandela Metropolitan Municipality (NMMM) to assess the value of MUAC as a predictor of malnutrition risk and develop malnutrition screening recommendations relevant to this population. Methods: This study followed a cross-sectional design using a quantitative approach. A convenience sample (n=419) of children below 24 months of age was selected from clinics and creches in Motherwell between October 2015 and February 2016 (Ethics approval: H15-HEA-DIET-002). Primary caregivers provided informed written consent for study participation. Trained fieldworkers performed anthropometric measurements according to standardised methods and completed a structured questionnaire. Data was described using means and standard deviations. Linear regression was used to assess relationships within the data. The MUAC’s ability to identify malnutrition was described using sensitivity and specificity probabilities. Results: Only 6% of the sample of children (n=23) were classified as stunted and 3% of the children (n=12) were severely stunted. The WHZ Z-score identified 0% (n=1) child with severe acute malnutrition (SAM), and 1% (n=3) children as MAM. The MUAC identified more children as SAM (2%) and MAM (3%). It was found that 16% of the children (n=65) were overweight or obese according to WHZ. It was found that there is a strong linear relationship between WHZ and MUAC (r=0.739). Using the least squares regression equation, a MUAC cut off value of 13,80cm for males and 13,5cm for females between six and 24 months old was projected. The male cut-off value has a 100% sensitivity and 94,5% specificity for MAM and SAM while the female MUAC cut off had a specificity of 96,4%. Low birth weight children had significantly (p<0.0005) lower mean WAZ and HAZ scores than normal birth weight children. Conclusions and recommendations The prevalence of overweight and obesity among children younger than two years was high in Motherwell, while stunting and wasting prevalence were lower than expected for the population. Raising the MUAC cut-off values from 12,5cm for MAM to 13,80cm for males and 13,47cm for females may increase the number of children younger than two years who are included in nutrition interventions. It is recommended that healthcare workers focus on breastfeeding and appropriate complementary feeding practices to reduce the risk of overweight in infants and young children