University of Arkansas at Monticello

Annual decreases in soybean (Glycine max L. Merrill) yield caused by diseases were estimated by surveying university-affiliated plant pathologists in 28 soybean-producing states in the United States and in Ontario, Canada, from 2010 through 2014. Estimated yield losses from each disease varied greatly by state or province and year. Over the duration of this survey, soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) was estimated to have caused more than twice as much yield loss than any other disease. Seedling diseases (caused by various pathogens), charcoal rot (caused by Macrophomina phaseolina (Tassi) Goid), and sudden death syndrome (SDS) (caused by Fusarium virguliforme O’Donnell & T. Aoki) caused the next greatest estimated yield losses, in descending order. The estimated mean economic loss due to all soybean diseases, averaged across U.S. states and Ontario from 2010 to 2014, was $60.66 USD per acre. Results from this survey will provide scientists, breeders, governments, and educators with soybean yield-loss estimates to help inform and prioritize research, policy, and educational efforts in soybean pathology and disease management.

Measurable sources of muscle tension include viscoelastic tone, physiological contracture (neither of which involve motor unit action potentials), voluntary contraction, and muscle spasm (which we define as involuntary muscle contraction). The latter two depend on motor unit action potentials to generate the tension. Total muscle tension is most accurately measured as stiffness. Thixotropy of muscle is an ubiquitous and functionally important phenomenon that is not commonly recognized. A clinical pain condition associated with increased muscle tension is tension-type headache, which is largely muscular in origin; it is often caused by myofascial trigger points, but not by a pain-spasm-pain cycle, which is a physiologically and clinically untenable concept. Clinical conditions associated with painful muscle spasm include spasmodic torticollis, trismus, unnecessary muscle tension, nocturnal leg cramps, and stiff-man syndrome.

OBJECTIVES: To compare the prevalence of motor endplate potentials (noise and spikes) in active central myofascial trigger points, endplate zones, and taut bands of skeletal muscle to assess the specificity of endplate potentials to myofascial trigger points. DESIGN: This nonrandomized, unblinded needle examination of myofascial trigger points compares the prevalence of three forms of endplate potentials at one test site and two control sites in 11 muscles of 10 subjects. The endplate zone was independently determined electrically. Active central myofascial trigger points were identified by spot tenderness in a palpable taut band of muscle, a local twitch response to snapping palpation, and the subject's recognition of pain elicited by pressure on the tender spot. RESULTS: Endplate noise without spikes occurred in all 11 muscles at trigger-point sites, in four muscles at endplate zone sites outside of trigger points (P = 0.024), and did not occur in taut band sites outside of an endplate zone (P = 0.000034). CONCLUSIONS: Endplate noise was significantly more prevalent in myofascial trigger points than in sites that were outside of a trigger point but still within the endplate zone. Endplate noise seems to be characteristic of, but is not restricted to, the region of a myofascial trigger point.

wide range of disciplines examined environmental and social determinants of health, identified key stakeholders, and assessed actions for the prevention, management, and control of adverse health outcomes associated with the country's urban experience. We conclude that key efforts are needed to combat urban health challenges in China and these should be unified with the Healthy Cities movement, which uses a systems approach to urban health management and provides a clear path to the realisation of the Healthy China 2030 plan.

Soybean (Glycine max [L.] Merrill) yield losses as a result of plant diseases were estimated by university and government plant pathologists in 29 soybean producing states in the United States and in Ontario, Canada, from 2015 through 2019. In general, the estimated losses that resulted from each of 28 plant diseases or pathogens varied by state or province as well as year. Soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) caused more than twice as much loss as any other disease during the survey period. Seedling diseases (caused by various pathogens), Sclerotinia stem rot (white mold) (caused by Sclerotinia sclerotiorum [Lib.] de Bary), and sudden death syndrome (caused by Fusarium virguliforme O’Donnell & T. Aoki) caused the next greatest yield losses, in descending order. Following SCN, the most damaging diseases in the northern United States and Ontario differed from those in the southern United States. The estimated mean economic loss from all soybean diseases, averaged across the United States and Ontario, Canada was US$45 per acre (US$111 per hectare). The outcome from the current survey will provide pertinent information regarding the important soybean diseases and their overall severity in the soybean crop and help guide future research and Extension efforts on managing soybean diseases.

Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Münch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem, but this hypothesis has long faced major challenges. The key issue is whether the conductance of sieve tubes, including sieve plate pores, is sufficient to allow pressure flow. We show that with increasing distance between source and sink, sieve tube conductivity and turgor increases dramatically in Ipomoea nil. Our results provide strong support for the Münch hypothesis, while providing new tools for the investigation of one of the least understood plant tissues.

The life cycles and transmission of most infectious agents are inextricably linked with climate. In spite of a growing level of interest and progress in determining climate change effects on infectious disease, the debate on the potential health outcomes remains polarizing, which is partly attributable to the varying effects of climate change, different types of pathogen-host systems, and spatio-temporal scales. We summarize the published evidence and show that over the past few decades, the reported negative or uncertain responses of infectious diseases to climate change has been growing. A feature of the research tendency is the focus on temperature and insect-borne diseases at the local and decadal scale. Geographically, regions experiencing higher temperature anomalies have been given more research attention; unfortunately, the Earth's most vulnerable regions to climate variability and extreme events have been less studied. From local to global scales, agreements on the response of infectious diseases to climate change tend to converge. So far, an abundance of findings have been based on statistical methods, with the number of mechanistic studies slowly growing. Research gaps and trends identified in this study should be addressed in the future.

Purpose– Seeks to understand how differences in national cultures impact on the understanding and meaning of the concept of self‐leadership and its application. Design/methodology/approach– First, research at the intersection of culture and leadership and Hofstede's culture framework are reviewed. Then the main components of self‐leadership theory are introduced, and how Hofstede's framework can be used to re‐analyze them given differences across cultures is discussed. Findings– While self‐leadership remains, in general, a valid concept, its understanding and application is likely to differ across cultures. Specifically, high power distance raises the importance of the symbolic value of tasks and correspondent covert processes of self‐leadership, high uncertainty avoidance makes more explicit the importance of non‐rational and intuition‐based thought processes, collectivism shows the relevance of social relations, femininity reiterates the importance of social relations and non‐rational processes, and long‐term orientation introduces the importance of making time an explicit element. Research limitations/implications– There is a need for further research on self‐leadership that investigates the roles of social and cultural relations, communication and language, multilevel interdependencies, and ethics. Empirically there is need for developing a self‐leadership instrument that is relevant and applicable across cultures. Practical implications– This paper should facilitate appreciation of a contingency perspective of self‐leadership that requires different modes of application across cultures. Originality/value– This paper helps fill a gap in the self‐leadership literature. In particular, it can facilitate greater understanding of this concept in cultures other than the USA, where it originated.

Abstract The efficiency of amino acid, organic acid and sugar metabolism was quantified for adult Homalodisca coagulata (Say) (Homoptera: Cicadellidae) by comparing chemical profiles of xylem fluid (food source) and insect exudate. Leafhoppers were confined in Parafilm® sachets to stems of 4 host plants: [Baccharis halimifolia (L.), Lagerstroemia indica (L.), Prunus salicina (Lindl.), Prunus persica (L.), Batsch]. Insect feeding rates (0.09‐0.27 ml h −1 ***), exudate osmolarity (7.8–12.8 mM) and exudate composition (mainly inorganic entities) were characteristic of a xylem feeder. Total organic solute concentration in the xylem fluid of B. halimifolia, L. indica, P. salicina and P. persica was ca. 9.4, 13,8, 5.5 and 1.8 mM, respectively. Nineteen protein amino acids, 7 organic acids and 3 or 4 sugars were identified in the xylem fluid. Total amino acids, organic acids and sugars were metabolized with ca. 99% efficiency. Glutamine, asparagine, arginine and citric, malic and succinic acids, the predominant organic compounds in the xylem fluid of all four plant species, were metabolized with greater than 99% efficiency. Cysteine (51%), methionine (74%) and oxalic acid (77%) were metabolized with the lowest efficiency. The primary nitrogenous waste was NH + 4 ; uric acid or urea were not detected. Nitrogen retention was generally less than 60% of dietary nitrogen. High feeding rates, ammonotelism and an extremely high metabolic efficiency of organic compounds permit H. coagulata to subsist on the dilute and skewed chemical profile of xylem fluid. Résumé Metabolisms des acides amines, des acides organiques et des sucres extraits de la sève du xylème de quatre plantes‐hôtes par Homalodisca coagulata L'efficacité du métabolisme des amino‐acides, des acides organiques et des sucres a été quantifiée chez des H. coagulata Say (Ho***rn. Cicadellidae) adultes, en comparant la composition chimique de la sève du xylème et du miellat des insectes. Les cicadelles ont été maintenues dans des sachets de parafilm avec des tiges de 4 plantes hôtes: Baccharis halimifolia L., Lagerstroemia indica L., Prunus salicina Lindl. et Prunus persica Batsch. Le taux de consommation (0,09 à 0,27 ml hr −1 , l'osmolarité du miellat (7,8 à 12,8 mM) et la composition du miellat (principalement des éléments inorganiques) sont caractéristiques des consommateurs de xylème. Les concentrations organiques totales en soluté de la sève du xylème étaient respectivement: 9,4; 13,8; 5,5; et 1,8 mM chez B. halimifolia, L. indica, P. salicina et P. persica. 19 amino acides protéiques, 7 acides organiques et 3 ou 4 sucres ont été identifiés dans la sève du xylème. Les acides aminés, les acides organiques et les sucres ont été metabolisés dans leur ensemble avec une efficacité de 99%. La glutamine, l'asparagine, l'arginine et les acides citrique, malique et succinique, ‐ les principaux composés organiques de la sève du xylème de ces 4 plantes, ‐ ont été metabolisés avec plus de 99% d'efficacité. La cysteine (51%), la méthionine (74%) et l'acide oxalique (77%) ont été métabolisés avec une plus faible efficacité. Le déchet azoté primarie était NH + 4 ; l'acide urique et lurée n'ont pas été décelés. La fixation d'azote a été généralement inférieure à 60% de l'azote consommé. Des taux de consommation élevés, l'ammonotélisme et une efficacité extrêmement élevée du métabolisme des composés organiques permettent à H. coagulata de survivre malgré la composition chimique biaisée et la dilution de la sève du xylème.

Spatial patterns in Classic Maya terminal monument dates offer clues about the processes behind the Classic “collapse” and the spatial scale of political competition that preceded it. A Darwinian theory of wasteful advertising delivers a simple model of how the collapse and political competition might map onto terminal monument dates. Modern statistical techniques provide the tools required to decompose spatial variation in terminal dates from a sample of 69 sites into the components required by the model. The large‐scale trend in the cessation of dated monument construction, estimated using local robust regression (loess), supports recent evidence that the ultimate cause of the end of dated monument construction was an ecological disaster. The variogram characterizes spatial variation in residuals from this trend. The results suggest that as the collapse proceeded, monument‐constructing elites, or individuals competing for that status, abandoned their original sites to enter political competition at sites on average 65 km distant, thus increasing competition, and prolonging monument construction at those recipient sites. This implies spheres of political competition in the Late Classic were small, and supports recent evidence from epigraphic sources they averaged about 50 km in diameter.

Zinc seed treatments for rice ( Oryza sativa L.) were previously evaluated as an alternative to soil‐applied Zn. Recommendations concerning the effectiveness of Zn seed treatments were never clearly stated. Our objectives were to evaluate the utility of Zn seed treatments for supplying Zn to rice grown on soils prone to Zn deficiency. In 1998, a study with three cultivars compared Zn‐treated seeds [2.8 g Zn (kg seed) −1 ] with a control and 11 kg Zn ha −1 as ZnSO 4 applied to the soil. Because tissue Zn concentration did not differ among cultivars, a single cultivar, Drew, was used in studies at two locations in 1999. The control and the soil‐applied Zn were compared with seeds that were treated with three rates of ZnSO 4 and ZnEDTA (ethylenediaminetetraacetic acid). Analysis showed net seed concentrations of 1.0, 2.2, and 4.7 g Zn (kg seed) −1 as ZnSO 4 and 1.4, 2.8, and 5.7 g Zn (kg seed) −1 as ZnEDTA. In 1998, neither visual Zn deficiency symptoms nor significant yield differences were observed among treatments. Soil‐applied Zn and Zn seed treatments increased tissue Zn concentration by 11.9 and 4.7 mg Zn kg −1 , respectively, above that of the control (19.7 mg Zn kg −1 ). In 1999, Zn deficiency occurred at both locations. Measurements of dry matter, tissue Zn concentration, and grain yield showed that Zn‐treated seed performed equal to or better than soil‐applied Zn. These data suggest that seed Zn concentrations between 2.2 to 5.7 g Zn (kg seed) −1 are an economical alternative to soil‐applied Zn.

An analysis of verbal behavior was undertaken to test principles of interpersonal deception theory (IDT). It was predicted that language choice in deceptive messages would reflect strategic attempts to manage information through nonimmediate language. This linguistic profile, though, was expected to be altered in response to preinteractional factors - relational and behavioral familiarity - and interactional factors - form of deception and receiver suspicion. Results from two investigations are reported: a secondary analysis on interactions in an earlier study (Burgoon, Buller, Dillman, & Walther, 1995) and analysis of a primary experiment employing a 2 (relationship) × 2 (receiver expertise) × 2 (receiver suspicion) × 2 (truth/deception) within-subjects factorial design. As expected, senders displayed greater verbal nonimmediacy when deceiving. Expertise had a greater effect on linguistic behavior than a prior relationship with the receiver, with senders using more verbal nonimmediacy with novice receivers. Senders were more verbally nonimmediate when equivocating. Suspicion produced a mixed pattern of linguistic cues. The possibility that changes produced by preinteraction and interactional factors were strategic attempts to bolster credibility is discussed.

Abstract: The capacity of a watershed to urbanize without changing its hydrologic response and the relationship between that response and the spatial configuration of the developed areas was studied. The study was conducted in the Whiteoak Bayou watershed (223 km 2 ), located northwest of Houston, Texas, over an analysis period from 1949 to 2000. Annual development data were derived from parcel data collected by the Harris County Appraisal District. Using these data, measures of the spatial configuration of the watershed urban areas were calculated for each year. Based on regression models, it was determined that the annual runoff depths and annual peak flows depended on the annual precipitation depth, the developed area and the maximum 12‐h precipitation depth on the day and day before the peak flow took place. It was found that, since the early 1970s, when the watershed reached a 10% impervious area, annual runoff depths and peak flows have increased by 146% and 159%, respectively. However, urbanization is responsible for only 77% and 32% of the increase, respectively, while precipitation changes are responsible for the remaining 39% and 96%, respectively. Likewise, an analysis of the development data showed that, starting in the early 1970s, urbanization in the watershed consisted more of connecting already developed areas than of creating new ones, which increases the watershed’s conveyance capacity and explains the change in its response. Before generalizing conclusions, though, further research on other urban watersheds with different urbanization models appears to be necessary.

The present paper describes the parametric design of a mixed-flow water-jet pump. The pump impeller and diffuser geometries were parameterized by means of an inverse design method, while CFD analyses were performed to assess the hydrodynamic and suction performance of the different design configurations that were investigated. An initial pump design was first generated and used as baseline for the parametric study. The effect of several design parameters was then analyzed in order to determine their effect on the pump performance. The use of a blade parameterization, based on inverse design, led to a major advantage in this study, because the three-dimensional blade shape is described by means of hydrodynamic parameters, such as blade loading, which has a direct impact on the hydrodynamic flow field. On the basis of this study, an optimal configuration was designed with the aim of maximizing the pump suction performance, while at the same time, guaranteeing a high level of hydrodynamic efficiency, together with the required mechanical and vibrational constraints. The final design was experimentally tested, and the good agreement between numerical predictions and experimental results validated the design process. This paper highlights the contrasting requirements in the pump design in order to achieve high hydrodynamic efficiency or good cavitation performance. The parametric study allowed us to determine design guidelines in order to find the optimal compromise in the pump design, in cases where both a high level of efficiency and suction performance must simultaneously be achieved. The design know-how developed in this study is based on flow field analyses and on hydrodynamic design parameters. It has therefore a general validity and can be used for similar design applications.

In this paper, we use a linear program to empirically decompose fitted neural networks into ensembles of low-bias sub-networks. We show that these sub-networks are relatively uncorrelated which leads to an internal regularization process, very much like a random forest, which can explain why a neural network is surprisingly resistant to overfitting. We then demonstrate this in practice by applying large neural networks, with hundreds of parameters per training observation, to a collection of 116 real-world data sets from the UCI Machine Learning Repository. This collection of data sets contains a much smaller number of training examples than the types of image classification tasks generally studied in the deep learning literature, as well as non-trivial label noise. We show that even in this setting deep neural nets are capable of achieving superior classification accuracy without overfitting.

Abstract Wetland mesocosms were exposed to increasing concentrations of atrazine over time at levels typical of midwestern surface waters following spring runoff (15 to 75 μg/L). Atrazine had a half-life of 8 to 14 d in the 230-m-long wetlands. End points measured included nutrient levels; periphyton biomass; periphyton productivity and respiration; growth of selected macrophytes; and survival and growth of Daphnia magna (15, 25 μg/L atrazine), Rana pipiens (15, 25 μg/L), and Pimephales promelas larvae (25 to 75 μg/L) and adults (50, 75 μg/L). Interaction between nutrient status or grazing intensity and atrazine effects were measured using periphyton enrichment and grazing exclosure experiments. Only periphyton, Ceratophyllum demersum, Zizania aquatica, and Daphnia were significantly affected by atrazine at any of the concentrations tested. Periphyton net productivity was significantly depressed by incubation in treated water as compared to control water at ≥25 μg/L atrazine (9 to 27-d exposures). In response, dissolved nutrient concentrations increased in treated mesocosms after 14 d. Ceratophyllum length/weight ratios increased after 6-d exposures to 50 μg/L atrazine, while Zizania senesced prematurely during treatments of 50 or 75 μg/L atrazine (97 d of cumulative exposure). Periphyton developed resistance to atrazine only at concentrations ≥50 μg/L. Atrazine effects on periphyton composition varied with the N:P supply ratio. Daphnia survival was significantly depressed at 15 μg/L atrazine (48-h exposures).

In this paper, we introduced major challenges in mapping croplands, settlements, water and wetlands, and discussed challenges in the use of multi-temporal and multi-sensor data. We then summarized some of the on-going efforts in improving qualities of global land cover maps. Existing technologies provide sufficient data for better map making if extra efforts can be made instead of harmonizing and integrating various global land cover products. Developing and selecting better algorithms, including more input variables (new types of data or features) for classification, having representative training samples are among conventional measures generally believed effective in improving mapping accuracies at local scales. We pointed out that data were more important in improving mapping accuracies than algorithms. Finally, we proposed a new paradigm for global land cover mapping, which included a view of vegetation classes based on their types and form, canopy cover and height. The new paradigm suggests that a universally applicable training sample set is not only possible but also effective in improving land cover classification at the continental and global scales. To ensure an easy transition from traditional land cover mapping to the new paradigm, we recommended that an all-in-one data management and analysis system be constructed.

Abstract The major limitation of diffusion methods for N analysis is the time required to obtain the results — typically from one to several days. Methods were developed that involve a much shorter period for diffusion. In these methods, 10‐ to 100‐mL samples of 2 or 4 M KCl soil extract or water were treated with MgO, or MgO plus Devarda's alloy, in a 473‐mL (1‐pint) wide‐mouth Mason jar to liberate NH 4 ‐N, NO 3 ‐N, and/or NO 2 ‐N as NH 3 . The jar was placed on an electric griddle maintained at 45 to 50°C. Gaseous NH 3 was collected in 5 mL of H 3 BO 3 indicator solution in a petri dish attached to the Mason jar lid, for quantitative determination by acidimetric titration. Complete recovery of 4 mg of N was achieved from 10 or 20 mL in 1.5 to 5 h. Recovery from 50 or 100 mL was complete in 5 to 8.5 h with 1 to 2 mg of N. The methods permit 15 N analysis of the diffused NH 3 ‐N. Isotopic analyses of labeled soil extracts were accurate to within 3%, as determined by isotope‐dilution calculations. Diffusions from 10 to 50 mL were subject to very little, if any, interference from decomposition of alkali‐labile organic‐N compounds.

Neve P, Norsworthy JK, Smith KL & Zelaya IA (2011). Modelling evolution and management of glyphosate resistance in Amaranthus palmeri . Weed Research 51 , 99–112. Summary A population‐based model was developed to simulate the evolution of glyphosate resistance in populations of Amaranthus palmeri . Model parameters were derived from published and unpublished sources, and the model was implemented using previously established principles and methods. Sensitivity analyses indicated that the model was sensitive to variations in population size, mutation rate and seed bank dynamics. A distribution was assigned to these parameters and Monte Carlo type simulations were performed. Simulation results are therefore derived from a range of possible input parameters, enabling the risk of resistance evolution to be assessed when parameter values were unknown, uncertain or variable. In the ‘worst‐case’ of five annual glyphosate applications in continuous glyphosate resistant cotton, evolution of glyphosate resistance was predicted in 39% of populations after 5 years and in c. 60% of populations after 10 years. These results are consistent with observations of the timescale for evolution of glyphosate resistance in A. palmeri in the field. The main drivers for glyphosate resistance evolution were selection pressure and population size, the greatest risks being associated with the largest A. palmeri populations. Risks of resistance were reduced when one of the five glyphosate applications was replaced by another mode of action with identical efficacy. However, not all glyphosate applications exerted the same selection pressure. Application of a soil residual herbicide at the time of crop sowing can provide control of A. palmeri well into the growing season and significantly reduced the rate and risk of glyphosate resistance evolution.

The purpose of this research was to examine the relationships among active listening, self-awareness, empathy, and patient-centered care in nursing students. Empathy and patient-centered care have been associated with better patient outcomes. Active listening and self-awareness are suggested to be associated with empathy, and, in turn, patient-centered care. However, the relationships among active listening, self-awareness, empathy, and patient-centered care have not been investigated. Data on active listening, self-awareness, empathy, and patient-centered care were collected from 53 nursing students, and were analyzed using multiple regression. Active listening (p < .001) and self-awareness (p < .001) were significantly associated with empathy. Empathy was significantly associated with patient-centered care (p = .003). Empathy was a partial mediator of the relationship between active listening and PCC and a full mediator of the relationship between self-awareness and patient-centered care. Improvement in active listening and self-awareness may lead to improvement in empathy, and, in turn, improvement in patient-centered care.