bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of Crop Rotation and Tillage Practices on Potato Yield and Farm Revenue
Authors: Liu Eric Ye , Li Sheng , Lantz Van , Olale Edward 
Published: May 2019

Core Ideas
The two‐step regression simulation approach was the most appropriate model to evaluate all important explanatory variables on mean potato yield.Potato yield increased when the frequency of potato increased in the rotation.Rotations with lower potato frequency had higher net revenue for the potato year; however, rotations with higher potato frequency had higher overall net revenues.The overall financial impacts of rotations with lower potato frequency were negative.Other incentives for adopting beneficial management practices are necessary.
To reduce the impacts of intensive potato (Solanum tuberosum L.) production systems on the environment, beneficial management practices (BMPs) (e.g., crop rotation and conservation tillage) have been promoted in Atlantic Canada. However, quantitative information on the impacts of BMPs on yield and farm revenue is still lacking. Direct assessment of BMPs in operating farms is difficult because producers adjust other inputs and practices when implementing BMPs. A dataset with 5 yr of crop rotation, farm inputs, and soil and climate data was obtained from farms in New Brunswick, Canada. Two‐step regression with a stochastic production function method was used to assess the impacts of three crop rotations and two tillage practices on potato yield. Potato yield increased when potato frequency increased in the rotation. This effect was largely caused by increased fertilizer and other inputs on rotations with a higher potato frequency. Spring moldboard plowing had negative effects on yield compared with fall moldboard plowing. The two‐step yield model was used with different scenarios to estimate the effect of crop rotation on farm revenue net of input costs. Rotations with lower potato frequency had higher net revenue for the potato year, largely because of reduced input costs. However, rotations with higher potato frequency had higher overall (multiyear) net revenues because of the more valuable potato years in the rotation. Therefore, without considering the long‐term impacts on the environment, the overall financial impacts of rotations with lower potato frequency were negative. This suggests that other incentives for adopting BMPs are necessary.
Response of Edamame Soybean Variety AVS 4002 to Herbicides
Authors: Abugho Seth Bernard , Burgos Nilda Roma , Singh Vijay , Salas Reiofeli , Ross William Jeremy , Popp Michael P. 
Published: May 2019

Core Ideas
Pyroxasulfone and linuron are acceptable preemergence herbicide options for edamame.Acifluorfen and fomesafen are potential postemergence herbicides.Edamame generally compensates for stand loss from residual herbicides.
Edamame (Glycine max L. Merr.) is a vegetable soybean whose consumption is expected to rise in the United States. Although only a few herbicides are currently registered for use in edamame, weeds are a major constraint of this crop. Field experiments were conducted in 2013 and 2014 in Kibler, AR, to evaluate the response of edamame cultivar AVS 4002 to 24 herbicide treatments and their efficacy on prominent crop weeds. Three of the treatments were applied 7 d preplant (PPL), 15 were applied preemergence (PRE), and 6 treatments were applied postemergence (POST). In 2013, fomesafen (0.42 kg ha−1), S‐metolachlor+fomesafen premix (1.39 kg ha−1), linuron (0.84 and 1.68 kg ha−1), pyroxasulfone (PRE) (0.14 kg ha−1), did not affect the stand of edamame. In 2014, all but two soil‐applied treatments, fomesafen and sulfentrazone+carfentrazone, reduced the stand by 24 to 50%. However, yield loss occurred with metribuzin (0.56 kg ha−1; PRE), and sulfentrazone (0.21 and 0.42 kg ha−1; PRE) applied alone or in tank mixture in 2013, and the high rate of sulfentrazone in 2014. Pyroxasulfone and linuron are acceptable PRE herbicide options for edamame. The premixes of flumioxazin+chlorimuron or saflufenacil+dimethenamid‐P applied PPL provided excellent weed control (>89%) at 35 d after planting (DAP). Among the POST treatments (foliar applied), acifluorfen, and fomesafen were the best options for Palmer amaranth (Amaranthus palmeri S. Watson) control, which provided at least 95 and 93% control, respectively, at 35 DAP. None of the foliar‐applied (POST) herbicides caused yield loss.
Soybean Nitrogen Sources and Demand During the Seed‐Filling Period
Authors: Ortez O.A. , Tamagno S. , Salvagiotti F. , Prasad P.V.V. , Ciampitti I.A. 
Published: May 2019

Core Ideas
Remobilization of N from vegetative organs fulfilled 59% of seed N, driven by plant biomass at R5.5.There was a trade‐off between N remobilization and N gain, connected to plant biomass and yield.Greater yields relied on both N remobilization and N gain during seed filling.
Soybean [Glycine max (L.) Merr.] seed N demand not met by biological N fixation is fulfilled by N remobilization from vegetative plant organs and N uptake from soil sources during the seed‐filling period (SFP), herein termed N gain. The objectives of this study were to: (i) quantify the contribution of plant organs to N remobilization during the SFP, (ii) determine the association between N gain and N remobilization, and (iii) study the effect of seed yield in both N gain and N remobilization processes. Three field experiments were conducted in 2015 and 2016 in Kansas. Three soybean genotypes: (i) non‐Roundup Ready (RR), released in 1997; (ii) RR‐1, released in 2009; and (iii) RR‐2, released in 2014 were tested under three N rates: (i) control without N application (zero‐N); (ii) 56 kg N ha−1 applied at R3 stage (late N); and (iii) 670 kg N ha−1 (full N; three applications of 223 kg N ha−1) applied at planting, R1, and R3 stages. The late‐N and full‐N rates increased yields by 9% (256 kg ha−1) relative to the zero N. Neither genotypes nor N rates affected N gain nor N remobilization. Nitrogen remobilization accounted for 59% of seed N demand at maturity, mainly driven by biomass at R5.5, with the leaf organ as the main contributor (52%) of the total remobilized N. Nitrogen remobilization was negatively related to N gain, and increases in N gain were linked to increases in biomass and yield.
Setting the Record Straight on Precision Agriculture Adoption
Authors: Lowenberg‐DeBoer James , Erickson Bruce 
Published: May 2019

Core Ideas
There is a perception that adoption of precision agriculture has been slow.Precision agriculture is not one technology but a toolkit from which farmers choose what they need.Global Navigation Satellite Systems guidance is being adopted rapidly.Variable rate technology adoption rarely exceeds 20% of farms.Use of precision agriculture technology on non‐mechanized farms is almost nonexistent.
There is a perception that adoption of precision agriculture (PA) has been slow. This study reviews the public data on farm level use of PA in crop production worldwide. It examines adoption estimates for PA from completed surveys that utilized random sampling procedures, as well as estimates of adoption using other survey methods, with an objective to document the national or regional level adoption patterns of PA using existing data. The analysis indicates that Global Navigation Satellite Systems (GNSS) guidance and associated automated technologies like sprayer boom control and planter row or section shutoffs have been adopted as fast as any major agricultural technology in history. The main reason for the perception that PA adoption is slow is because PA is often associated with variable rate technology (VRT)—just one of many PA technologies, one of the first adopted by many farmers, but that now rarely exceeds 20% of farms. This level of adoption suggests that farmers like the idea of VRT, but are not convinced of its value. VRT adoption estimates for niche groups of farmers may exceed 50%. The biggest gap in PA adoption is for medium and small farms in the developing world that do not use motorized mechanization.
Impacts of Soil Phosphorus Drawdown on Snowmelt and Rainfall Runoff Water Quality
Authors: Liu Jian , Elliott Jane A. , Wilson Henry F. , Baulch Helen M. 
Published: May 2019

Managing P export from agricultural land is critical to address freshwater eutrophication. However, soil P management, and options to draw down soil P have received little attention in snowmelt‐dominated regions because of limited interaction between soil and snowmelt. Here, we assessed the impacts of soil P drawdown (reducing fertilizer P inputs combined with harvest removal) on soil Olsen P dynamics, runoff P concentrations, and crop yields from 1997 to 2014 in paired fields in Manitoba, Canada. We observed that Olsen P concentrations in the 0‐ to 5‐cm soil layer were negatively correlated with the cumulative P depletion and declined rapidly at the onset of the drawdown practice (3.1 to 5.4 mg kg−1 yr−1 during 2007–2010). In both snowmelt runoff and rainfall runoff, concentrations of total dissolved P (TDP) were positively correlated with the concentrations of soil Olsen P. Soil P drawdown to low to moderate fertility levels significantly decreased mean annual flow‐weighted TDP concentrations in snowmelt runoff from 0.60 to 0.30 mg L−1 in the field with high initial soil P and from 1.17 to 0.42 mg L−1 in the field with very high initial soil P. Declines in TDP concentration in rainfall runoff were greater. Critically, yields of wheat (Triticum spp.) and canola (Brassica napus L.) were not affected by soil P depletion. In conclusion, we demonstrate that relatively rapid reductions in P loads are achievable at the field scale via managing P inputs and soil P pools, highlighting a management opportunity that can maintain food security while improving water security in cold regions.Core Ideas
Reducing or ceasing soil P input decreased soil Olsen P rapidly.
Soil Olsen P concentrations were negatively correlated with cumulative P depletion.
Declining soil P led to decreases in flow‐weighted mean dissolved P concentrations.
Improved water quality can be achieved with management of soil P.
Agricultural productivity can also be maintained with lower soil P.
Quantifying Clay‐Fixed Ammonium in Paddy Soils and Determining Its Availability Using Alkaline Distillation
Authors: Drescher Gerson L. , Roberts Trenton L. , Norman Richard J. , Slaton Nathan A. , da Silva Leandro S. 
Published: May 2019

Core Ideas
Alkaline hydrolyzable nitrogen recovery is influenced by soil drying.
N‐STaR soil test quantifies a portion of clay‐fixed ammonium.
NaOH recovered more clay‐fixed ammonium than KOH.
The Nitrogen Soil Test for Rice (N‐STaR, Oryza sativa L.) has been calibrated and is being used to predict rice nitrogen (N) fertilizer rates. Research has identified the organic forms of N quantified via N‐STaR (NH4 released by distillation with 10 mol L–1 NaOH), but no research has looked at the ability of N‐STaR to quantify clay‐fixed NH4 (CF‐NH4). This laboratory trial was initiated to determine the amount of CF‐NH4 quantified via N‐STaR as well as the influence of soil drying conditions (oven dry vs. field moist) and alkali distillation method (NaOH vs. KOH) on the CF‐NH4 recovered. Seven soils representing five clayey and two loamy soil textures were collected from various rice‐producing regions across Arkansas from the 0‐ to 15‐cm and 15‐ to 30‐cm soil depths. Total CF‐NH4 and CF‐NH4 recovered by N‐STaR varied greatly across soils and soil depths with a range of 35 to 299 mg N kg soil–1 and 6 to 21 mg N kg soil–1, respectively. The N‐STaR recovered as much as 15% of total CF‐NH4 and recovery was greatest for silt loam soils. Alkaline hydrolyzable‐N (AH‐N) concentrations were strongly influenced by soil drying conditions and the alkali used with a higher level (22%) of AH‐N recovered from oven‐dry than field‐moist soils and a higher (7%) recovery of AH‐N with NaOH than KOH. These results indicate that the N‐STaR method recovers a small, but significant percentage of total CF‐NH4 and may capture the portion of CF‐NH4 that may be plant available during the growing season.
Design and simulation analysis of an improved wearable power knee exoskeleton
Authors: Wang Fangzheng , Yan Lei , Xiao Jiang , Fan Lei 
Published: May 2019

The wearable lower limb power robotic exoskeleton is a device that can improve the human walking ability. In this paper, an improved exoskeleton device for knee joint is designed, including the improvement of mechanical structure and hydraulic cylinder. In order to verify the effectiveness of the improvement of the hydraulic cylinder, we have carried out the following studies. Firstly, in terms of mechanical structure, length adjusting device is added to meet the needs of different people. At the same time, a limit device is added to the knee joint to improve the safety performance and comfort. Secondly, the dynamics of the model is carried out by Lagrange, and the exoskeleton model is established for ADAMS motion simulation. The force of ADAMS simulation, the calculated by Lagrange equation and the force of the first edition of hydraulic cylinder are compared, and the force selection of hydraulic cylinder is analyzed. By comparison with the first edition, the optimization rate of the improved hydraulic cylinder reaches 8 %. Finally, in order to verify the rationality of ADAMS simulation and the effectiveness of hydraulic cylinder improvement, the wear test is carried out, the average errors of leg centroid in normal walking, wearing exoskeleton walking and ADAMS simulation data are compared. The average error rate is less than 10 %. The results show that the simulation model design is reasonable, and the effectiveness of the hydraulic cylinder improvement is verified. The exoskeleton device designed can well follow the human motion. The simulation analysis of the exoskeleton provides important parameters for the manufacture and it also provides theoretical basis for the later control theory.
Interactive Image Segmentation using Neighborhood Spatial Information and Statistical Grey Level on Dental Panoramic Radiograph
Authors: Choirunnisa Shabrina , Firmanto Ari , Zaenal Agus 
Published: May 2019

In dental panoramic radiographs, grey-level intensity information has been widely used for object segmentation in digital image. However, low contrast in the radiograph image causes high ambiguity that can cause the inconsistency of classification result. Since the grey-level intensity of background and object is almost similar, so in order to improve the segmentation result, the spatial distance on neighborhod region is applied. In this paper, we proposed a novel strategy to measure the distance using neighborhod spatial information and statistical grey level technique for image segmentation. The proposed method starts by calculating adjacency matrix and measured spatial distance on neighborhood region. Since the value of both distances are not in the same range, then the normalization is needed. The distances merging is approached by tuning the weight using several constant values. The experiment results show that our proposed merging strategy has better segmentation result based on Relative Foreground Area Error value.
An advective-dispersive transport model for residential water consumption
Authors: Enouy Robert W. , Unger Andre J. A. , Rehan Rashid 
Published: May 2019

Abstract
This work applies an advective-dispersive framework to simulate utility-wide residential water consumption using the analogy of a continuum transport process. In this context, the advective-dispersive process describes how changes in real water price and seasonal weather variability influence water consumption distribution, which ultimately governs mean and total water consumption values. Water consumption response is measured using histogram data optimally fit using parametric probability density functions (PDF) that have consistent parametrization over the entire observation period. Median statistic denotes advection and prescribes location of the measurement-space PDF, while standard deviation combined with standard-score PDF denotes dispersion which provides the measurement-space PDF with scale and shape. Combining location, scale, and shape components produces a measurement-space PDF that represents the solution to advective-dispersive transport phenomena. We use a Taylor series expansion of the statistics that define the PDF along with curvilinear regression to develop constitutive relationships that define how location, scale, and shape of the PDF respond to price and weather information. This results in a fully parametrizing advective-dispersive process represented by a partial differential equation that provides a tool for anticipating the probability that households will experience water poverty or use excess amounts as price, weather, and policy considerations change through time. This approach is conducive to automation when combined with smart water metering.
Liberdade e Coexistência: A Sociedade Pós-Emancipação nas Planícies Colombianas do Pacífico
Authors: Vital André Vasques 
Published: May 2019

Book Review: Leal C 2018. Landscapes of freedom: building a postemancipation society in the rainforests of western Colombia. The University of Arizona Press, Tucson, 352 pp.
Development and Validation of a Rapid and Sensitive Method for the Simultaneous Estimation of Gemigliptin and Teneligliptin in Bulk and Dosage Forms by Using Liquid Chromatography-tandem Mass Spectrometry
Authors: Chandra Amrish , Rathod Ramji , Ali Faraat , Prakash Anuj , Kumar Robin , Singh Gyanendra Nath 
Published: May 2019

Background:
A simple and sensitive ultra-performance liquid chromatography-mass
spectrometry method was developed and validated to measure the concentrations of gemigliptin
(GEM) and teneligliptin (TEN) using pioglitazone (PIO) as an internal standard.

Methods:
Chromatographic separation of two gliptins was achieved on a C-18 (100 mm X 2.1
mm, 2.7 μm) column using a mobile phase consisting of formic acid in water (0.1 % v/ v): acetonitrile
in gradient elution. Electrospray ionization (ESI) source was operated in positive mode (ionization).
Targeted MS-MS mode on a quadrupole time of flight (Q-TOF) mass spectrometer was
used to quantify the drugs utilizing the mass transitions of 490.1 (m/z), 427.2 (m/z) and 357.1
(m/z) for GEM, TEN and PIO, respectively.

Results:
As per ICH Q2R1 guidelines, a detailed validation of the method was carried out and the
standard curves were found to be linear between the concentration ranges of 509.8-1529.4 ng mL-1
and 510.6-1531.7 ng mL-1 for GEM and TEN, respectively. Precision and accuracy results were
found to be within the acceptable limits. The mean recovery was found to be 98.8± 0.76 % (GEM)
and 98.6 ±0.98 % (TEN), respectively.

Conclusions:
The optimized validated UPLC-QTOF (MS-MS) method offered the advantage of
shorter analytical times and higher sensitivity and selectivity to the nanogram level.
Evolution Over Time of Volume Status and PD-Related Practice Patterns in an Incident Peritoneal Dialysis Cohort
Authors: Van Biesen Wim , Verger Christian , Heaf James , Vrtovsnik François , Britto Zita M. Leme , Do Jun-Young , Prieto-Velasco Mario , Martínez Juan Pérez , Crepaldi Carlo , De los Ríos Tatiana , Gauly Adelheid , Ihle Katharina , Ronco Claudio ,   for the IPOD-PD Study Group
Published: May 2019

Background and objectives
Volume overload is frequent in prevalent patients on kidney replacement therapies and is associated with outcome. This study was devised to follow-up volume status of an incident population on peritoneal dialysis (PD) and to relate this to patient-relevant outcomes.

Design, setting, participants, & measurements
This prospective cohort study was implemented in 135 study centers from 28 countries. Incident participants on PD were enrolled just before the actual PD treatment was started. Volume status was measured using bioimpedance spectroscopy before start of PD and thereafter in 3-month intervals, together with clinical and laboratory parameters, and PD prescription. The association of volume overload with time to death was tested using a competing risk Cox model.

Results
In this population of 1054 participants incident on PD, volume overload before start of PD amounted to 1.9±2.3 L, and decreased to 1.2±1.8 L during the first year. At all time points, men and participants with diabetes were at higher risk to be volume overloaded. Dropout from PD during 3 years of observation by transfer to hemodialysis or transplantation (23% and 22%) was more prevalent than death (13%). Relative volume overload >17.3% was independently associated with higher risk of death (adjusted hazard ratio, 1.59; 95% confidence interval, 1.08 to 2.33) compared with relative volume overload ≤17.3%. Different practice patterns were observed between regions with respect to proportion of patients on PD versus hemodialysis, selection of PD modality, and prescription of hypertonic solutions.

Conclusions
In this large cohort of incident participants on PD, with different treatment practices across centers and regions, we found substantial volume overload already at start of dialysis. Volume overload improved over time, and was associated with survival.
THE EFFECTS OF NAFTA ON ECONOMIC GROWTH
Authors: Cuevas Ahumada Víctor M. , López Churata Roger Ivanodik Juan 
Published: May 2019

<p align="center"><strong>ABSTRACT</strong></p><p>This paper evaluates the effects of the North American Free Trade Agreement on the economic growth of Mexico, the United States and Canada by means of an augmented Solow growth model. Such a model is estimated with panel data through two econometric methods: 1) the Arellano-Bond dynamic panel Generalized Method of Moments, and 2) Feasible Generalized Least Squares. The two techniques are consistent in indicating that trade raises Gross Domestic Product (GDP) per capita, controlling for physical capital stock per capita, human capital formation, total factor productivity, and the capital depreciation rate. However, the most important source of GDP per capita growth is human capital formation, which highlights the need to promote trade while investing more in long-term formal education, short-term training programs and the whole process of knowledge transferring.</p><p> </p><p align="center"><strong>LOS EFECTOS DEL TLCAN EN EL CRECIMIENTO ECONÓMICO</strong></p><p align="center"><strong>RESUMEN</strong></p>Esta investigación evalúa los efectos del Tratado de Libre Comercio de América del Norte en el crecimiento económico de México, Estados Unidos y Canadá mediante una versión ampliada del modelo de crecimiento de Solow. El modelo se estima con datos en panel mediante dos métodos: 1) el método generalizado de momentos de Arellano y Bond, el cual se aplica a un panel dinámico y 2) mínimos cuadrados generalizados factibles. Ambos indican que el comercio incrementa el producto interno bruto (PIB) per cápita, controlando para el <em>stock</em> de capital físico y humano, la productividad total de los factores y la tasa de depreciación del capital. Sin embargo, la principal fuente de crecimiento económico es la formación de capital humano, por lo que se debe estimular el comercio internacional e invertir más en educación formal de largo plazo, programas de capacitación de corto plazo y todo el sistema de transferencia del conocimiento.