Effects of combined conservation practices on soil and water quality in the Central Mississippi River Basin

Conventional cultivation of claypan soils leads to soil and water quality degradation because of high runoff and associated soil erosion. The Goodwater Creek Experimental Watershed, which is part of the USDA Agricultural Research Service Benchmark Conservation Effects Assessment Project, Watershed Assessment Studies, was established to address these issues. Plot studies have highlighted trade-offs between erosion control and herbicide or nutrient runoff. There is a need for long-term field-scale evaluation of combined practices that reduce sediment, nutrient, and herbicide losses by runoff. A 36 ha field located in Missouri was under a conventional corn (Zea mays L.)-soybean (Glycine max L.) system from 1993 to 2003 with fertilizer application and tillage prior to planting in the spring. A precision agriculture system defined by two main management zones was implemented from 2004 to 2014: Wheat (Triticum aestivum L.) and soybean in 60% of the field, and corn and soybean in the remaining 40%. The system included no-till, cover crops, atrazine split-applications based on weed pressure, variable rates of nitrogen (N), and variable rates of fall-applied phosphorus (P). The objective of this study was to compare runoff water quality from the two management systems, based on flow and load duration curves, cumulative distribution functions, and conclusions from replicated plot studies. The precision agriculture system did not affect annual runoff, but it did increase the frequency of low flows. Sediment losses were reduced by 87% as a result of no-till and cover crops. Atrazine and P losses were lower than expected, despite the lack of incorporation into the soil. Atrazine losses were possibly lower because of the wheat area acting as a buffer, greater atrazine adsorption and retention in the field, and faster decay. Dissolved P losses as a fraction of applied remained the same, likely because of greater adsorption and lower runoff risk when applying P. Finally, nitrate-N (NO3-N) losses decreased and resulted in an overall decrease of N losses despite a slight increase of ammonium-N (NH4-N) losses. Explanations includeincluded a greater soil water content, a different timing of N applications, and N uptake by cover crops. Building on these successes, an aspirational management system is proposed to further improve on the performance and practicality of the precision agriculture system

Implementation of duty of candour within neurosurgery: a national survey and framework for improved application in clinical practice

INTRODUCTION: Statutory duty of candour was introduced in November 2014 for NHS bodies in England. Contained within the regulation were definitions regarding the threshold for what constitutes a notifiable patient safety incident. However, it can be difficult to determine when the process should be implemented. The aim of this survey was to evaluate the interpretation of these definitions by British neurosurgeons. MATERIALS AND METHODS: All full (consultant) members of the Society of British Neurological Surgeons were electronically invited to participate in an online survey. Surgeons were presented with 15 cases and asked to decide in the case of each one whether they would trigger the process of duty of candour. Cases were stratified according to their likelihood and severity. RESULTS: In all, 106/357 (29.7%) members participated in the survey. Responses varied widely, with almost no members triggering the process of duty of candour in cases where adverse events were common (greater than 10% likelihood) and required only outpatient follow-up (7/106; 6.6%), and almost all members doing so in cases where adverse events were rare (less than 0.1% likelihood) and resulted in death (102/106; 96.2%). However, there was clear equipoise in triggering the process of duty of candour in cases where adverse events were uncommon (0.1-10% likelihood) and resulted in moderate harm (38/106; 35.8%), severe harm (57/106; 53.8%) or death (49/106; 46.2%). CONCLUSION: There is considerable nationwide variation in the interpretation of definitions regarding the threshold for duty of candour. To this end, we propose a framework for the improved application of duty of candour in clinical practice

Model and Sensor-Based Recommendation Approaches for In-Season Nitrogen Management in Corn

Nitrogen management for corn (Zea mays L.) may be improved by applying a portion of N in-season. This investigation was conducted to evaluate crop modeling (Maize-N) and active crop canopy sensing approaches for recommending in-season N fertilizer rates. These approaches were evaluated during 2012–2013 on 11 field sites, in Missouri, Nebraska, and North Dakota. Nitrogen management also included a no-N treatment (check) and a non-limiting N reference (all at planting). Nitrogen management treatments were assessed for two hybrids and at low and high seeding rates, arranged in a randomized complete block design. In 9 of 11 site-years, the sensor-based approach recommended lower in-season N rates than the model (collectively 59% less N), resulting in trends of higher partial factor productivity of nitrogen (PFPN) and higher agronomic efficiency (AE) than the model. However, yield was better protected by the model-based approach. In some situations, canopy sensing excelled at optimizing the N rate for localized conditions. With abnormally warm and moist soil conditions for the 2012 Nebraska sites and presumed high levels of inorganic N from mineralization, N application was appropriately reduced, resulting in no yield decrease and N savings compared to the non-limiting N reference. Depending on the site, both recommendation approaches were successful; a combination of model and sensor information may optimize in-season decision support for N recommendation

Sceptical Employees as CSR Ambassadors in Times of Financial Uncertainty

This chapter offers new insights into the understanding of internal (employee) perceptions of organizational corporate social responsibility (CSR) policies and strategies. This study explores the significance of employees’ involvement and scepticism upon CSR initiatives and focuses on the effects it may have upon word of mouth (WOM) and the development of employee–organisation relationships. Desk research introduces the research questions. Data for the research questions were gathered through a self-completion questionnaire distributed in a hardcopy form to the sample. An individual’s level of scepticism and involvement appears to affect the development of a positive effect on employees’ WOM. Involvement with the domain of the investment may be a central factor affecting relationship building within the organization, and upon generation of positive WOM. The chapter offers a conceptual framework to public relations (PR) and corporate communications practitioners, which may enrich their views and understanding of the use and value of CSR for communication strategies and practices. For-profit organisations are major institutions in today’s society. CSR is proffered as presenting advantages for (at macro level) society and (micro level) the organization and its employees. Concepts, such as involvement and scepticism, which have not been rigorously examined in PR and corporate communication literature, are addressed. By examining employee perceptions, managers and academic researchers gain insights into the acceptance, appreciation and effectiveness of CSR policies and activities upon the employee stakeholder group. This will affect current and future CSR communication strategies. The knowledge acquired from this chapter may be transferable outside the for-profit sector

Segmentation of vestibular schwannoma from MRI, an open annotated dataset and baseline algorithm

Automatic segmentation of vestibular schwannomas (VS) from magnetic resonance imaging (MRI) could significantly improve clinical workflow and assist patient management. We have previously developed a novel artificial intelligence framework based on a 2.5D convolutional neural network achieving excellent results equivalent to those achieved by an independent human annotator. Here, we provide the first publicly-available annotated imaging dataset of VS by releasing the data and annotations used in our prior work. This collection contains a labelled dataset of 484 MR images collected on 242 consecutive patients with a VS undergoing Gamma Knife Stereotactic Radiosurgery at a single institution. Data includes all segmentations and contours used in treatment planning and details of the administered dose. Implementation of our automated segmentation algorithm uses MONAI, a freely-available open-source framework for deep learning in healthcare imaging. These data will facilitate the development and validation of automated segmentation frameworks for VS and may also be used to develop other multi-modal algorithmic models

XTE J0111.2-7317 : a nebula-embedded X-ray binary in the SMC

The observed characteristics of the nebulosity surrounding the SMC High Mass X-ray Binary XTE J0111.2-7317 are examined in the context of three possible nebular types: SNR, bowshock and HII region. Observational evidence is presented which appears to support the interpretation that the nebulosity surrounding XTE J0111.2-7317 is an HII region. The source therefore appears to be a normal SMC Be X-ray binary (BeXRB) embedded in a locally enhanced ISM which it has photoionised to create an HII region. This is supported by observations of the X-ray outburst seen with BATSE and RXTE in 1998-1999. It exhibited characteristics typical of a giant or type II outburst in a BeXRB including large spin-up rates, Lx~10E38 erg/sq.cm-s, and a correlation between spin-up rate and pulsed flux. However, the temporal profile of the outburst was unusual, consisting of two similar intensity peaks, with the first peak of shorter duration than the second.Comment: Accepted for publication by MNRA

Updated Three-Stage Model for the Peopling of the Americas

Background: We re-assess support for our three stage model for the peopling of the Americas in light of a recent report that identified nine non-Native American mitochondrial genome sequences that should not have been included in our initial analysis. Removal of these sequences results in the elimination of an early (i.e.,40,000 years ago) expansion signal we had proposed for the proto-Amerind population. Methodology/Findings: Bayesian skyline plot analysis of a new dataset of Native American mitochondrial coding genomes confirms the absence of an early expansion signal for the proto-Amerind population and allows us to reduce the variation around our estimate of the New World founder population size. In addition, genetic variants that define New World founder haplogroups are used to estimate the amount of time required between divergence of proto-Amerinds from the Asian gene pool and expansion into the New World. Conclusions/Significance: The period of population isolation required for the generation of New World mitochondrial founder haplogroup-defining genetic variants makes the existence of three stages of colonization a logical conclusion. Thus, our three stage model remains an important and useful working hypothesis for researchers interested in the peopling of th

Water channel pore size determines exclusion properties but not solute selectivity

Aquaporins (AQPs) are a ubiquitous family of transmembrane water channel proteins. A subgroup of AQP water channels also facilitates transmembrane diffusion of small, polar solutes. A constriction within the pore, the aromatic/arginine (ar/R) selectivity filter, is thought to control solute permeability: previous studies on single representative water channel proteins suggest narrow channels conduct water, whilst wider channels permit passage of solutes. To assess this model of selectivity, we used mutagenesis, permeability measurements and in silico comparisons of water-specific as well as glycerol-permeable human AQPs. Our studies show that single amino acid substitutions in the selectivity filters of AQP1, AQP4 and AQP3 differentially affect glycerol and urea permeability in an AQP-specific manner. Comparison between in silico-calculated channel cross-sectional areas and in vitro permeability measurements suggests that selectivity filter cross-sectional area predicts urea but not glycerol permeability. Our data show that substrate discrimination in water channels depends on a complex interplay between the solute, pore size, and polarity, and that using single water channel proteins as representative models has led to an underestimation of this complexity

Active-Optical Reflectance Sensing Corn Algorithms Evaluated over the United States Midwest Corn Belt

Uncertainty exists with corn (Zea mays L.) N management due to year-to-year variation in crop N need, soil N supply, and N loss from leaching, volatilization, and denitrification. Activeoptical reflectance sensing (AORS) has proven effective in some fields for generating N fertilizer recommendations that improve N use efficiency, but locally derived (e.g., within a US state) AORS algorithms have not been tested simultaneously across a broad region. The objective of this research was to evaluate locally developed AORS algorithms across the US Midwest Corn Belt region for making in-season corn N recommendations. Forty-nine N response trials were conducted across eight states and three growing seasons. Reflectance measurements were collected and sidedress N rates (45–270 kg N ha–1 on 45 kg ha–1 increments) applied at approximately V9 corn development stage. Nitrogen recommendation rates from AORS algorithms were compared with the end-of-season calculated economic optimal N rate (EONR). No algorithm was within 34 kg N ha–1 of EONR \u3e 50% of the time. Average recommendations differed from EONR 81 to 147 kg N ha–1 with no N applied at planting and 74 to 118 kg N ha–1 with 45 kg of N ha–1 at planting, indicating algorithms performed worse with no N applied at planting. With some algorithms, utilizing red edge instead of the red reflectance improved N recommendations. Results demonstrate AORS algorithms developed under a particular set of conditions may not, at least without modification, perform very well in regions outside those within which they were developed

Improving an Active-Optical Reflectance Sensor Algorithm Using Soil and Weather Information

Active-optical reflectance sensors (AORS) use light reflectance characteristics from a crop canopy as an indicator of the plant’s N health. However, studies have shown AORS algorithms used in conjunction with measured reflectance characteristics for corn (Zea mays L.) N fertilizer rate recommendations are not consistently accurate. Our objective was to determine if soil and weather information could be utilized with an AORS algorithm developed at the University of Missouri (ALGMU) to improve in-season (~V9 corn development stage) N fertilizer recommendations. Nitrogen response trials were conducted across eight states over three growing seasons, totaling 49 sites with soils ranging in productivity. Nitrogen fertilizer rates according to the ALGMU were compared to economic optimal nitrogen rate (EONR). Without soil and weather information included, the root mean square error (RMSE) of the difference between ALGMU and EONR (MUDIFF) was 81 and 74 kg N ha–1 for treatments receiving 0 and 45 kg N ha–1 applied at planting, respectively. When ALGMU was adjusted using weather (seasonal precipitation and distribution prior to sidedress) and soil clay content, the RMSE was reduced by 24 to 26 kg N ha–1. Without adjustment, 20 and 29% of sites were within 34 kg N ha–1 of EONR with 0 and 45 kg N ha–1 at planting, respectively. But with adjustment for soil and weather data, 45 and 51% of sites were within 34 kg N ha–1 of EONR. These results show that weather and soil information could be used to improve ALGMU N recommendation performance