bluuebunny/crossref_metadata_2025 huggingface dataset:
Transient carrier recombination dynamics in potential‐induced degradation p‐type single‐crystalline Si photovoltaic modules
Authors: Aminul Islam Mohammad , Matsuzaki Hiroyuki , Okabayashi Yuusuke , Ishikawa Yasuaki
Published: May 2019

In this study, we investigated the recombination dynamics of minority carriers through the decay profile analysis of transient diffuse reflectance spectroscopy (TDRS) for fresh and potential‐induced degradation (PID) modules. The PID‐affected region in terms of the degradation degree on the modules was firstly localized using conventional methods such as electroluminescence (EL) and lock‐in thermal images. The photogenerated carrier density and carrier lifetime were different in photovoltaic (PV) modules in fresh and PID modes. It was found that the dominant recombination involved the carrier transition via shallow trap states. The distribution of the trap states, however, was extended from the surface to the bulk of the solar cell due to Na ions–decorated defects. The behaviors of the carrier dynamics near the surface and bulk were very different, as inferred from the two different pump wavelengths of 532 and 1064 nm, respectively.
Illness perceptions and perceived stress in patients with advanced gastrointestinal cancer
Authors: Miceli Jessica , Geller David , Tsung Allan , Hecht Carol Lynn , Wang Yisi , Pathak Ritambhara , Cheng Hannah , Marsh Wallis , Antoni Michael , Penedo Frank , Burke Lora , Ell Kathleen , Shen Shutian , Steel Jennifer
Published: May 2019

Objective

According to the Common‐Sense Model of Self‐Regulation, when faced with a health threat, we make cognitive and emotional assumptions about the illness. The aims of this study were to (a) examine the role of sociodemographic and disease‐specific factors on illness perception and perceived stress and (b) test the association between perceived stress and illness perception in participants diagnosed with gastrointestinal cancer.

Methods

Participants completed a battery of questionnaires including a Sociodemographic and Disease‐Specific Questionnaire, the Illness Perception Questionnaire, Brief Version (Brief‐IPQ), and the Perceived Stress Scale (PSS‐14). Descriptive statistics, Pearson correlations, analysis of variance (ANOVA), and linear regression were performed to test the hypotheses.

Results

Of the 627 participants, the mean age was 62 years (SD = 11); the majority were male (63.3%) and Caucasian (90.9%). Younger (F3,625 = 5.80, P < .01) and divorced or never married participants reported higher levels of perceived stress when compared with older and married participants (F4,618 = 3.52, P < .01). Younger participants (18‐74 years old) reported more negative illness perceptions than older participants (75 years and older) (F3,511 = 4.08, P < .01). A weak, positive relationship between perceived stress and illness perceptions was observed (r = 0.22, P < .01), and illness perceptions predicted 36.1% of the variance of perceived stress.

Conclusions

Our findings suggest that participants who negatively perceived their illness experienced greater levels of perceived stress. Interventions that aim to adjust patients' illness perceptions in order to facilitate a reduction of stress and improvement in quality of life are needed.
Effect of late preterm birth on lung clearance index and respiratory physiology in school‐age children
Authors: Yaacoby‐Bianu Karin , Plonsky Moran T. , Gur Michal , Bar‐Yoseph Ronen , Kugelman Amir , Bentur Lea
Published: May 2019

Background

We hypothesized that former late preterm (LP) children have abnormal pulmonary physiology parameters, including uneven ventilation distribution, due to premature disruption of normal lung development.

Methods

A cross‐sectional study evaluating former LP children at the age of 6 to 12 years as compared to term controls. Demographics and child's and family history of asthma/atopy/smoking were recorded. The outcome parameters were spirometry, multiple breath washout (MBW) measurement by lung clearance index (LCI), 6‐minute walk test (6MWT), symptoms related to asthma and allergy, and Godin Leisure‐Time Exercise Questionnaire.

Results

Twenty‐nine former LP were compared to 30 term‐control children (mean age, 8.2 ± 1.7 and 8.8 ± 1.8 years, respectively). LP had reduced forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) compared to term controls (FEV1 1.59 ± 0.48 vs 1.80 ± 0.39 L, P = 0.005 and FVC 1.73 ± 0.45 vs 1.99 ± 0.49 L, P = 0.009). There were no differences between the two groups regarding FEV1/FVC, forced expiratory flow between 25 and 75 (FEF25‐75), LCI (7.10 ± 0.79 vs 6.96 ± 0.75, P = 0.50), 6MW distance, and weekly leisure‐activity score. Former LP children had more episodes of wheezing and greater use of asthma medication.

Conclusions

This pilot study suggests that LP have lower pulmonary function tests (PFTs) but not ventilation inhomogeneity measured by LCI or functional disturbance. It is unclear if the differences in PFTs are due to late prematurity by itself or are the consequence of maternal and neonatal factors associated with LP. Further larger studies are required to assess the long‐term respiratory consequences of LP birth.
Mechanics of nasal mask‐delivered HFOV in neonates: A physiologic study
Authors: Centorrino Roberta , Dell’Orto Valentina , Gitto Eloisa , Conti Giorgio , De Luca Daniele
Published: May 2019

Objectives

To clarify if nasal mask influences noninvasive high‐frequency oscillatory ventilation (NHFOV) mechanics to optimize the clinical use of nasal mask‐delivered NHFOV.

Working Hypothesis

Nasal mask may affect the mechanical efficacy of NHFOV.

Methodology

We designed a physiologic study composed of an in vitro phase aiming to investigate pressure transmission and volume delivery in a bench model of nasal mask‐delivered NHFOV. In a second phase, we measured the leaks in vivo in a series of neonates receiving nasal mask‐delivered NHFOV or other forms of noninvasive respiratory support with same nasal masks.

Results

In vitro pressure transmission is lower with nasal mask (pressure at the lung [Plung]: 2 [0.8]), than with the endotracheal tube (Plung 9.5 [1.5] cmH2O; P = 0.007). Same applies for volume delivery (Vol: 0.6 [0.2] vs 1.8 [0.5] mL; P = 0.0001). Increasing ventilatory boundaries slowly affects pressure and volume delivery. Ventilating the model with maximal parameters (∆P = 55 cmH2O; frequency = 8 Hz) we obtained a Vol 1.5 (0.2) mL. The nasal mask provides lower volume delivery and ventilation, compared with nasal prongs studied in previously published studies. Changing frequency allows a better performance than changing ∆P. In vivo leaks are approximately 30% and are similar during NHFOV or other forms of nasal mask‐delivered noninvasive ventilation.

Conclusions

Nasal mask‐delivered NHFOV is feasible, but it may require more aggressive ventilatory parameters to increase volume delivery and ventilation. The use of the nasal mask is associated with some leaks, but this is independent from the type of noninvasive respiratory support applied.
Axion from Quivers in Type II Superstrings
Authors: Belhaj A. , Douhou K. , Ennadifi S. E. , del Moral M. P. Garcia
Published: May 2019

We investigate a string‐inspired axion extension of the standard model obtained from Type II superstrings using quiver method. In the first part, we discuss intersecting Type IIA D6‐branes wrapping non trivial 3‐cycles in the presence of the Peccei‐Quinn symmetry U(1). Concretely, a complex scalar field , where σ is a stringy axion generates a general fermion Yukawa coupling weighted by a flavor‐dependent power taking specific values. Using string theory and standard model data with adequate scales, we show that the corresponding axion window could lie in the allowed range matching with the recent cosmological results.
Wilson Surfaces for Surface Knots: A Field Theoretic Route to Higher Knots
Authors: Zucchini Roberto
Published: May 2019

Holonomy invariants in strict higher gauge theory have been studied in depth aiming to applications to higher Chern–Simons theory. For a flat 2–connection, the holonomy of surface knots of arbitrary genus has been defined and its covariance properties under 1–gauge transformation and change of base data have been determined. Using quandle theory, a definition of trace over a crossed module such to yield surface knot invariants upon application to 2–holonomies has been given.
TMPRSS2‐ERG fusions linked to prostate cancer racial health disparities: A focus on Africa
Authors: Blackburn James , Vecchiarelli Stefano , Heyer Erin E. , Patrick Sean M. , Lyons Ruth J. , Jaratlerdsiri Weerachai , van Zyl Smit , Bornman M. S. Riana , Mercer Tim R. , Hayes Vanessa M.
Published: May 2019

Background

The androgen‐regulated gene TMPRSS2 to the ETS transcription factor gene ERG fusion is the most common genomic alteration acquired during prostate tumorigenesis and biased toward men of European ancestry. In contrast, African American men present with more advanced disease, yet their tumors are less likely to acquire TMPRSS2‐ERG. Data for Africa is scarce.

Methods

RNA was made available for genomic analyses from 181 prostate tissue biopsy cores from Black South African men, 94 with and 87 without pathological evidence for prostate cancer. Reverse transcription polymerase chain reaction was used to screen for the TMPRSS2‐ERG fusion, while transcript junction coordinates and isoform frequencies, including novel gene fusions, were determined using targeted RNA sequencing.

Results

Here we report a frequency of 13% for TMPRSS2‐ERG in tumors from Black South Africans. Present in 12/94 positive versus 1/87 cancer negative prostate tissue cores, this suggests a 92.62% predictivity for a positive cancer diagnosis (P = 0.0031). At a frequency of almost half that reported for African Americans and roughly a quarter of that reported for men of European ancestry, acquisition of TMPRSS2‐ERG appears to be inversely associated with aggressive prostate cancer. Further support was provided by linking the presence of TMPRSS2‐ERG to low‐grade disease in younger patients (P = 0.0466), with higher expressing distal ERG fusion junction coordinates.

Conclusions

Only the second study of its kind for the African continent, we support a link between TMPRSS2‐ERG status and prostate cancer racial health disparity beyond the borders of the United States. We call for urgent evaluation of androgen deprivation therapy within Africa.
In Situ AFM Analysis of Surface Electron Behaviors of Strain‐Free and Deformed Ferrite and Austenite in Duplex Steel and Their Correlation with Electron Work Function
Authors: Guo Liqiu , Li Lei , Li Qingyang , Li Wei , Chen D. L. , Li D. Y.
Published: May 2019

Surface electron state and kinetic behavior as well as their spatial distributions strongly influence surface properties of microscopically inhomogeneous materials and related processes. Using a multi‐mode atomic force microscope, electron work functions and surface electrical currents of ferrite and austenite in duplex steel are in situ analyzed. Along with slightly higher work function, the austenite shows higher electrical conductance than ferrite, which is consistent with first‐principles calculations. Local plastic deformation introduced by micro‐indentation results in considerable changes. The current around indents on austenite slightly increases along with lowered work function, while that around the indent on ferrite increases significantly accompanied with lowered work function. Efforts are made to understand mechanisms for the observed phenomena.
Advances in the Profiling of Single‐Cell DNA Modifications
Authors: Bai Dongsheng , Yi Chengqi
Published: May 2019

Epigenetic modifications on DNA include canonical 5‐methylcytosine (5mC) and its iteratively oxidized derivatives mediated by TET dioxygenase: 5‐hydroxymethylcytosine (5hmC), 5‐formylcytosine (5fC), and 5‐carboxycytosine (5caC). All of them have been recognized to play important roles in gene expression regulation and to be indispensable for normal mammalian reproduction and development. In order to understand the mechanisms underlying these roles, over the past few decades, technical advances have been made to comprehensively profile the distribution pattern of bulk epigenetic modifications in genomic DNA. Recently, single‐cell methods have identified the epigenetic patterns even within an individual cell. This review focuses on single‐cell DNA epigenetic modifications sequencing technologies and their applications, and gives prospects on the development of single‐cell methods based on bisulfite‐free strategy.
In Situ Investigation of Layered Oxides with Mixed Structures for Sodium‐Ion Batteries
Authors: Keller Marlou , Eisenmann Tobias , Meira Debora , Aquilanti Giuliana , Buchholz Daniel , Bresser Dominic , Passerini Stefano
Published: May 2019

Experimentalists and theoreticians commonly prefer single‐phase materials for their studies, since this allows for a direct correlation of the findings obtained and the compound studied. For the design of high‐performance materials for energy applications, however, mixtures of different phases frequently reveal an advanced set of desired properties. Recently, it has been shown that a combination of different phases, that is, P2/P3/O3‐ NaxMn0.5Ni0.3Fe0.1Mg0.1O2, allows for higher capacities and enhanced cycling stability when employed as sodium‐on cathode compared to pure P2‐NaxMn0.7Ni0.1Fe0.1Mg0.1O2 or O3‐type NaxMn0.5Ni0.3Fe0.1Mg0.1O2. Herein, the in‐depth comparative investigation of these three materials is presented via in situ X‐ray diffraction and X‐ray absorption spectroscopy coupled with electrochemical techniques to fully elucidate the origin of this superior performance. In fact, it appears that the redox activity or inactivity of the manganese cation plays a decisive role for the reversibility of the sodium‐ion uptake and release.
Zur Kritik der Heteronormativität – Queere Perspektiven in der Psychotherapie
Authors: Hutfless Esther
Published: May 2019

Psychiatrische Diskurse über Perversionen und „sexuelle Abirrungen“ sowie die Entwicklung und Wirkmacht von Diagnose-Manualen, die Homo- und Transsexualität als psychische Störungen charakterisierten und dies im Fall von Trans* aber z. B. auch Transvestitismus noch immer tun, ebenso die heteronormativen Vorstellungen unserer Kultur, sind mit psychotherapeutischen Diskursen eng verschränkt.

In der therapeutischen Praxis bedeutet dies unter anderem noch immer, dass Menschen, die psychotherapeutische Hilfe suchen und nicht der „Norm“ entsprechen, mit Vorurteilen, stereotypen Geschlechter‑, Beziehungs- und Sexualitätsvorstellungen konfrontiert sind oder sowohl ihre Lebensentwürfe als auch ihr Begehren als Ausdruck psychischer Unreife beurteilt werden.

Darüber hinaus reproduzieren psychotherapeutische Diskurse nicht nur diskriminierende Strukturen, sondern sind mit Michel Foucault vielmehr selbst Teil jenes Macht-Wissenskomplexes, der Subjekte auf spezifische Weise hervorbringt und damit zugleich reguliert.

Anti-Diskriminierungspolitiken, die Forderungen nach Gleichstellung ausgehend von einer unterdrückten sozialen Gruppe formulieren, haben zwar gesellschaftspolitisch viel erreicht, doch werden sie von diskurstheoretischen Ansätzen dafür kritisiert, dass sie die Identitätskategorien „unterdrückter“ oder „ausgeschlossener“ Subjekte und damit die Entgegensetzung und Hierarchisierung zwischen Norm und Abweichung weiter fortschreiben und Identitäten essentialisieren oder aber „ausgeschlossene“ Subjekte in die heteronormative Ordnung assimilieren, um für sie ebenfalls „Normalität“ zu proklamieren, was zu einer erneuten Unterwerfung führt.

Im vorliegenden Artikel möchte ich daher über gleichstellungspolitische Ansätze hinausgehen, da diese Ansätze Identitätskategorien re-produzieren und fortschreiben. Stattdessen werde ich – ausgehend von queeren Konzepten – dafür plädierenden, den Bereich der Norm selbst in Frage zu stellen und zu dekonstruieren. Darüberhinaus werde ich zeigen, inwiefern insbesondere queere Ansätze als produktive und kritische Interventionen in psychotherapeutischen Diskursen und Praxen wirken können.
Tree and stand level estimations of Abies alba Mill. aboveground biomass
Authors: Jagodziński Andrzej M. , Dyderski Marcin K. , Gęsikiewicz Kamil , Horodecki Paweł
Published: May 2019

Key message

We provided a complete set of tree- and stand-level models for biomass and carbon content of silver firAbies alba. This allows for better characterization of forest carbon pools in Central Europe than previously published models. The best predictor of biomass at the stand level is stand volume, and the worst are stand basal area and density.

Context

Among European forest-forming tree species with high economic and ecological significance,Abies albaMill. is the least characterized in terms of biomass production.

Aims

To provide a comprehensive set of tree- and stand-level models forA. albabiomass and carbon stock. We hypothesized that (among tree stand characteristics) volume will be the best predictor of tree stand biomass.

Methods

We studied a chronosequence of 12A. albatree stands in southern Poland (8–115 years old). We measured tree stand structures, and we destructively sampled aboveground biomass of 96 sample trees (0.0–63.9 cm diameter at breast height). We provided tree-level models, biomass conversion and expansion factors (BCEFs) and biomass models based on forest stand characteristics.

Results

We developed general and site-specific tree-level biomass models. For stand-level models, we found that the best predictor of biomass was stand volume, while the worst were stand basal area and density.

Conclusion

Our models performed better than other published models, allowing for more reliable biomass predictions. Models based on volume are useful in biomass predictions and may be used in large-scale inventories.
Current Strategies in the Management of Peyronie’s Disease (PD)—Results of a Survey of 401 Sexual Medicine Experts Across Europe
Authors: Porst Hartmut , Burri Andrea ,   the European Society for Sexual Medicine (ESSM) Educational Committee
Published: May 2019

Introduction

Peyronie’s disease (PD) is a progressive and devastating penile disorder that often results in severe penile curvature with penile shrinking, making vaginal insertion difficult or even impossible. Until now, in contrast to other penile disorders such as erectile dysfunction, PD is characterized by a paucity of conservative treatment options.

Aim

To investigate the current status quo in the management of PD across European experts in sexual medicine.

Methods

Members of the European Society of Sexual Medicine and of various andrology and urology societies across Europe, with the majority (78%) being urologists, were contacted via e-mail and newsletters and asked to fill in an online questionnaire. The survey comprised 56 items developed by an expert consensus of the educational committee of the European Society of Sexual Medicine. In the end, 401 participants responded to the entire survey, with 277 reporting treating PD patients themselves and knowing this penile entity very well.

Main Outcome Measures

Main outcome measures include description of current strategies regarding diagnosis and treatment of PD as reported by specialists in this field.

Results

Of the physicians treating PD patients, 94% performed penile palpation, and 74% perform ultrasonography. 45% assessed the degree of penile curvature by means of intravenous drug testing, but only 17% measured it accurately with a goniometer. Penile length, flaccid or in erect state, was measured by only 39% or 25%, respectively. Only 45% assessed testosterone. Primary treatment options were oral (65%), counseling (57%), and topical/local therapy (30%). Among oral drug users, tadalafil 5 mg was the most commonly used (57%), followed by vitamin E (40%). Regarding intralesional therapy, collagenase clostridium histolyticum was the leading drug (34%), followed by calcium channel blockers (17%). Considering surgical procedures, the original Nesbit technique was the preferred procedure (33%). 36% of the specialists expressed their dissatisfaction with the currently available treatment options, and 64% reported the impression that their patients were mostly dissatisfied with the treatment outcomes.

Clinical Implications

Innovative and presumably multi-modal treatment protocols for PD are urgently needed.

Strengths & Limitations

The survey represents 1 of the largest studies on the management of PD. The results are representative for the standard management of PD mostly among European Urologists with specialization in sexual medicine and may therefore not be generalizable to regions outside Europe or to other physicians treating PD.

Conclusion

Around one-third of experts and, from their perspective, around two-thirds of patients are dissatisfied with the currently available PD treatment options.
The Coptic Wizard's Hoard
Authors: Mirecki Paul
Published: May 2019

Within the large collection of ancient manuscripts at the University of Michigan there is a group of Coptic papyri which appears to have been a hoard or library of ancient magical texts. Produced by five copyists sometime in the fourth through seventh centuries and originating from a now unknown location in Egypt, the collection was brought to the British Museum by Sir E. A. Wallis Budge in February 1921 for restoration by C. T. Lamacraft; in August of that year, it underwent philological examination by the Coptic lexicographer Walter E. Crum, and was later forwarded to the University of Michigan.
Evagrius, Paul of Nisibis and the Problem of Loyalties in the Mid Sixth Century
Authors: Lee A. D.
Published: May 2019

In 561/2, a few years before the death of the Emperor Justinian, Roman envoys concluded a peace treaty with the Persian Empire. A detailed account of the negotiations and terms is preserved among the surviving portions of the sixth-century history by Menander Protector. For the immediate purposes of this paper, the most important features of this treaty were that it ended more than twenty years of intermittent warfare between the two empires, that the treaty was to remain in force for fifty years, and that the Romans were required to make substantial payments of gold to the Persians at a rate of 30,000solidiper year.
The Reasonableness of Christianity? Gilbert Burnet and the Trinitarian Controversy of the 1690s
Authors: Greig Martin
Published: May 2019

In the course of the 1690s and into the early eighteenth century a number of English divines and laymen became embroiled in a pamphlet war on the doctrine of the Trinity. It was a wide-ranging debate and its participants included Anglicans, Roman Catholics, Socinians, deists and Arians. Until recently, however, this controversy had received scant attention from historians. It is only within the last few years that an interest in the trinitarian controversy has emerged: a number of works have appeared on the more notable of the late seventeenth- and early eighteenth-century anti-trinitarian thinkers, and J. C. D. Clark has pointed out the political implications of anti-trinitarian views. There is, nevertheless, one aspect of the trinitarian controversy which has remained relatively untouched, and that is the debate on the Trinity which raged within the Established Church.
‘Églises plantées’ and ‘églises dressées’ in the Historiography of Early French Protestantism
Authors: Wilcox Peter
Published: May 2019

During the seven years between 1555 and 1562, a transformation took place in the character of early French Protestantism. Before 1555 reformed communities in the kingdom of France were relatively scarce, and only loosely affiliated; by 1562 they had become more numerous, and more centralised. Before 1555 a typical congregation would meet, without either a minister or a system of ecclesiastical discipline, for prayers, the singing of hymns and bible-reading; by 1562, the same group would probably have not only its own pastor to preach and administer the sacraments, but also a consistory to enforce church discipline. In the most recent secondary literature this development is commonly described as the transformation of églises plantées into églises dressées. It is said, for example by Prestwich, that ‘the consistory became the mark of a true church, termed an église dressée, in contrast to the amorphous Bible gatherings, known as églises plantées’. The purpose of this brief article is to question whether these terms were ever contrasted in this way in the mid-sixteenth century, and to suggest that other phrases express the development more accurately.
Late Mississippian Productoid BrachiopodsInflatia, Keokukia, andAdairia, Ozark Region of Oklahoma and Arkansas
Authors: Gordon Mackenzie , Henry Thomas W. , Treworgy Janis D.
Published: May 2019

Specimens of the Late Mississippian productoid generaInflatiaandKeokukiafrom northeastern Oklahoma and northwestern Arkansas, collected from the Boone and “Moorefield” Formations, Hindsville Limestone, and Fayetteville Shale, display morphologic similarities and differences that delineate species and determine their biostratigraphic ranges. Generic assignments are based primarily on internal characters. Systematic descriptions include seven species ofInflatiaMuir-Wood and Cooper:Productus inflatusMcChesney (the type species),P. cherokeensisDrake,P. clydensisGirty (figured herein for the first time and for which a lectotype is designated), four new species ofInflatia(I. cooperi, I. gracilis, I. pusilla, andI.?succincta), and one species ofKeokukia(the type species for the genus,K. sulcataCarter). Also proposed and described is a new genus,Adairia, with its type speciesProductus(Marginifera)adairensisDrake. All these species ofInflatia, Keokukia, andAdairiahave biostratigraphically restricted ranges within the Meramecian and Chesterian sequence in the Ozark region.
Spread of Water and Oil Droplets on Johnsongrass (Sorghum halepense) Leaves
Authors: Mcwhorter Chester G. , Ouzts Clark , Hanks James E.
Published: May 2019

Comparative spread of droplets of several different oils and water with different adjuvants on leaf surfaces was investigated. Spread was better on the lower surface of johnsongrass leaves than on upper leaf surfaces with nine of 14 oils studied; two spread best on upper leaf surfaces, and three were equal in spread on both surfaces. Differences in spread coefficients did not appear to be directly related to surface tension, viscosity, or mid-boiling point of the oils. Soybean or cottonseed oils did not spread as well as petroleum oils but methylated soybean and sunflower oils had high spread coefficients on both upper and lower leaf surfaces. All but one petroleum-base oil spread three to four times better on leaf surfaces than on oil-sensitive paper. Water mixtures of an organosilicone surfactant spread much better on water-sensitive paper and on johnsongrass leaves than water with conventional adjuvants, but spread of paraffinic oils exceeded that of any water-adjuvant mixture. Spread coefficients of most petroleum-base oils were better on lower than upper leaf surfaces. Spread usually increased as the age of leaves increased from 14 to 56 d. Water droplets with adjuvant had at least an 86% weight loss after 6 min, but low volatile paraffinic oil droplets had little weight loss 2 d after application.
Simulation Analysis of Weed Population Dynamics in Ridge-Tilled fields
Authors: Jordan Nicholas
Published: May 2019

Effects of nonchemical weed control on weed and seedbank demography in ridge-tilled fields were simulated to examine long-term effects on weed population dynamics. Ridge tillage entails active seedbank management, including removal of much of the seedbank from the crop growth zone (ridge) to the interridge zone (furrow) at planting, and other seedbank manipulations. Dynamics of simulated yellow foxtail and velvetleaf populations were sharply sensitive to the rate of seed removal from the ridge. Variation in winter seed survival, ridge plant demography (emergence, survival, and seed production), and seed survival in the furrow after removal from the ridge also had strong effects on simulated dynamics. To prevent rapid population growth in a simulated corn-soybean rotation, very effective control of seedlings emerging with each crop was necessary to offset seed production from seedlings emerging after ridge rebuilding in corn years. Dynamics of both species were highly sensitive to cultivation efficiency. Effective “rescue” weed control must be available to prevent sharp increases in weed seedbanks during years when cultivation is ineffective.
Absence of a Role for Absorption, Translocation, and Metabolism in Differential Sensitivity of Hemp Dogbane (Apocynum cannabinum) to Two Pyridine Herbicides
Authors: Orfanedes Michael S. , Wax Loyd M. , Liebl Rex A.
Published: May 2019

Hemp dogbane is sensitive to fluroxypyr and tolerant to clopyralid. Absorption, translocation, and metabolism of clopyralid and fluroxypyr were studied in hemp dogbane to determine if differences in these processes could be responsible for differential sensitivity. In addition, the effect of growth stage on herbicide absorption and translocation was evaluated. The14C-herbicides were applied to the adaxial side of a single leaf located near the midpoint of hydroponically cultured plants. Uptake of fluroxypyr was more rapid than clopyralid. At 72 h after treatment (HAT), fluroxypyr and clopyralid absorption was 62 and 38%, respectively. Clopyralid was much more mobile than fluroxypyr, with 75% of the absorbed14C from14C-clopyralid recovered outside the treated leaf compared to only 45% for fluroxypyr 72 HAT. Relative to fluroxypyr, a higher percentage of14C-clopyralid recovered outside the treated leaf translocated acropetally, especially when plants were treated during the vegetative stage. Treatment during the early reproductive stage increased basipetal and reduced acropetal translocation relative to the vegetative stage. Neither herbicide was metabolized rapidly. Approximately 60 and 90% of the recovered14C was attributable to unaltered fluroxypyr and clopyralid, respectively, 72 HAT. Some differences in absorption, translocation, and metabolism between clopyralid and fluroxypyr exist, but they cannot fully account for differential sensitivity of hemp dogbane to these two herbicides. Differences in activity at the target site may be responsible for differential activity of these herbicides on hemp dogbane.
Distribution of Imported Glyphosate in Quackgrass (Elytrigia repens) Rhizomes in Relation to Assimilate Accumulation
Authors: Shieh Wen-Jang , Geiger Donald R. , Buczynski Stephen R.
Published: May 2019

The fact that quackgrass may occasionally escape control by the herbicide glyphosate is thought to result from the wide range in growth rate and sink activity among rhizome buds, especially in older portions of the rhizome. To study growth of rhizome structures, we supplied whole plants with14CO2throughout a 10-h light period and determined the amount of labeled carbon accumulated by the end of the subsequent 14-h night. Growth of rhizome structures during this 24-h period was estimated by determining their growth rate coefficients: the amount of labeled carbon accumulated per unit of carbon present in the structure. Growth rate coefficients generally were high for the rhizome tip that is enclosed in a sheath and the adjacent bud and rhizome segment, with values decreasing rapidly in a basipetal direction. However, extensive differences in the level and pattern of assimilate accumulation among rhizome structures were observed as rhizome development continued. Glyphosate accumulation generally paralleled the level of assimilate accumulation even though the range among rhizome structures for both increased with rhizome age. As a result of the increased variability among buds, some of the older buds will accumulate only a small, perhaps sublethal, amount of glyphosate and this may explain the tendency of the buds in older regions to escape control by glyphosate.
Interaction of Surfactant and Leaf Surface in Glyphosate Absorption
Authors: Knoche Moritz , Bukovac Martin J.
Published: May 2019

The effect of oxyethylene (OE) chain length of three homologous series of nonionic surfactants (allinol, nonoxynol, octoxynol) on glyphosate uptake was markedly affected by the leaf surface fine-structure of sugarbeet and kohlrabi. Adaxial leaf surfaces of sugarbeet were covered with a layer of amorphous wax, whereas the adaxial surface of kohlrabi leaves was covered with fine crystalline wax. Foliar uptake of glyphosate (1 mM glyphosate, 20 mM glycine, pH 3.2) averaged 4% for sugarbeet without surfactant, but droplets were not retained by kohlrabi leaves in the absence of a surfactant. Glyphosate absorption with octoxynol (9 to 10 OE units, 0.5 g L−1) was rapid initially (0 to 2 h) and leveled off about 2 h after application in both species. Absorption by sugarbeet decreased from 12 to 3% as OE content of octoxynol was increased from 5 to 30 OE units. In contrast, surfactants of intermediate OE content (octoxynol, 16 OE units) induced the greatest uptake (17%) on kohlrabi. Leaf wetting was markedly affected by surfactant and leaf surface. As OE content of octoxynol increased from 5 to 30 OE units, droplet/leaf interface areas of 1-μl droplets decreased from 4 to 3 mm2on the adaxial leaf surface of sugarbeet and from 61 to 2 mm2on kohlrabi. Concurrently, the rate of droplet evaporation (1 μl) decreased from 1.0 to 0.7 nl s−1on sugarbeet and 4.2 to 0.5 nl s−1on kohlrabi leaves. The effect of OE content on enhancement of glyphosate uptake and wetting characteristics of spray solutions was similar within species for different hydrophobic moieties but differed markedly between species.
Bermudagrass (Cynodonspp.) Suppression in Creeping Bentgrass (Agrostis stolonifera) with Herbicide-Flurprimidol Treatments
Authors: Johnson B. Jack , Carrow Robert N.
Published: May 2019

A mixture of bermudagrass with creeping bentgrass on golf greens results in a poor putting surface. An experiment was conducted to determine the frequency of herbicides applied alone or with flurprimidol on growth suppression of three bermudagrass cultivars and on tolerance of creeping bentgrass. Ethofumesate plus flurprimidol applied initially in mid-March or early April at 1.7 + 0.8 kg ha−1and followed by four applications of 0.4 + 0.2 kg ha−1beginning 6 wk later and then at 3-wk intervals, effectively suppressed bermudagrass growth throughout the growing season regardless of cultivar. Creeping bentgrass treated with ethofumesate plus flurprimidol at 1.7 + 0.8 kg ai ha−1caused > 30% injury for 3 to 4 wk following application in 2 of 3 yr, but the turfgrass fully recovered. Injury was < 30% when ethofumesate plus flurprimidol was applied as repeated applications at 0.4 + 0.2 kg ha−1. Siduron plus flurprimidol applied initially in March or April at 54 + 0.8 kg ai ha−1and followed by four additional applications at 14 + 0.2 kg ha−1did not effectively suppress bermudagrass growth. Results with siduron alone at 54 kg ha−1in March or April and repeated at monthly intervals at the same rate throughout the summer were similar to that obtained with siduron plus flurprimidol. Fenoxaprop applied at 0.07 kg ai ha−1in early April and repeated at monthly intervals through August at the same rate effectively suppressed growth of common bermudagrass but did not suppress growth of Tifway or Tifgreen bermudagrasses. Creeping bentgrass was severely injured following fenoxaprop treatments.
Differential Herbicide Response Among Sulfonylurea-ResistantKochia scopariaL. Accessions
Authors: Sivakumaran K. , Mulugeta D. , Fay P. K. , Dyer W. E.
Published: May 2019

Three chlorsulfuron-resistant kochia accessions were tested for levels of resistance to sulfonylurea and imidazolinone herbicides, based on whole plant response and sensitivity of the target enzyme. The resistant Minot and Chester accessions were not affected by treatment with 175 g ha−1chlorsulfuron, and I50values for the Chester accession ranged from 22-fold (metsulfuron-methyl) to 196-fold (chlorsulfuron) higher than the susceptible Bozeman accession. However, the Chester accession was 1.5- to 2-fold more resistant than Minot to five sulfonylurea herbicides, as determined by acetolactate synthase (ALS) I50values. The third resistant accession (Power) displayed an intermediate response and was only 2- to 5-fold more resistant than the susceptible Bozeman accession to all sulfonylurea herbicides tested. The Minot and Chester accessions were slightly cross-resistant to four imidazolinone herbicides, ranging from 2-fold (imazamethabenz, imazethapyr, and imazaquin) to 6-fold (imazapyr) more resistant than the Bozeman accession, but cross-resistance levels did not differ appreciably between the Minot and Chester accessions. The Power accession was not cross-resistant to the four imidazolinone herbicides tested. The results demonstrate that degrees of ALS resistance and cross-resistance are highly variable among kochia populations: these differences may be due to the type of mutation in the gene encoding ALS.
The Germination Stimulant AC94377 Reduces Seed Survival of Wild Mustard (Sinapis Arvensis)
Authors: Donald William W. , Tanaka Fred S.
Published: May 2019

Annual application of AC-94377 at 3.4 kg ha−1in the field reduced survival of shallowly buried (1.25 cm deep), undisturbed wild mustard seed compared to untreated check seed in two 4-yr-long trials. By the second fall, greater than twofold more untreated check seed survived as did AC-94377-treated seed. Moreover, no AC-94377-treated seed survived beyond year three following treatment in fall alone or fall plus spring in each of 3 yr. In contrast, 25% of untreated check seed survived into the fall of year four. AC-94377 applied in spring alone, fall alone, or both spring and fall for each of 4 yr progressively reduced seed survival. Seed survival expressed as a percent of the initial number of seed buried was best modeled as a negative exponential function of time in years. In the greenhouse, more wild mustard seed on the soil surface established after AC-94377 treatment at 3.4 kg ha−1when enclosed in large seed packets (5 by 12 cm), like those used in the field, than when in small seed packets (5 by 6.25 cm), whether or not the packets contained soil. When soil was added to either sized seed packet, fewer seed survived compared to seed not in seed packets or seed in packets without soil. Thus, it is likely that the field seed survival study underestimated effectiveness of AC-94377 to reduce wild mustard seed survival.
The Critical Period of Weed Control in Soybean [Glycine max(L.) Merr.]
Authors: Van Acker Rene C. , Swanton Clarence J. , Weise Stephan F.
Published: May 2019

Field studies were conducted at three locations over 2 yr in southern Ontario to determine the critical period of weed control in soybean. This period generally consisted of two discrete periods, a critical weed-free period and a critical time of weed removal. The critical weed-free period was relatively short in duration and consistent across locations and years. A period of weed control lasting up to the fourth node growth stage (V4), approximately 30 days after emergence (DAE), was adequate to prevent a yield loss of more than 2.5%. The critical time of weed removal was variable across locations and years and ranged, for example, from the second node growth stage (V2) to the beginning pod growth stage (R3), approximately 9 to 38 DAE, at a 2.5% yield loss level. A phenologically based period of most rapid yield loss due to weed interference occurred from beginning bloom stage (R1) to beginning seed stage (R5). The short and consistent critical weed-free period indicates the duration of residual herbicide control necessary in soybean and supports use of nonresidual, postemergence herbicides and mechanical weed control.
Propanil Resistance in Populations of Junglerice (Echinochloa colona) in Colombian Rice Fields
Authors: Fischer Albert J. , Granados Eduardo , Trujillo Diego
Published: May 2019

Dose-response studies estimating GR40 values indicated different levels of propanil resistance in junglerice populations from fields previously treated with propanil, compared to a check population collected where this herbicide had never been used. The GR40 for susceptible populations ranged from 0.36 to 0.50 kg ai ha−1and for resistant populations ranged from 1.10 to 3.10 kg ai ha−1. Considerable variability in growth and morphology existed among populations. Variability in cumulative leaf area, aboveground biomass, mean relative growth rate, mean net assimilation rate, and mean leaf area ratio could not be related to propanil resistance. Competitiveness was not related to propanil resistance either. of several vegetative and reproductive parameters measured at maturity, only grain weight per plant and number of grains per plant were correlated with GR40 (r = −0.73, P = 0.06). This trend towards lower reproductive fitness in propanil-resistant junglerice plants may reduce its ecological success when growing with propanil-susceptible plants in the absence of this herbicide.
Weed Suppression by Live and Desiccated Hairy Vetch (Vicia villosa)
Authors: Teasdale John R. , Daughtry Craig S. T.
Published: May 2019

Hairy vetch was grown as a winter annual cover crop and evaluated for weed suppression when desiccated by paraquat or left alive until natural senescence in a 3-yr field experiment. Total weed density and biomass were variable in the desiccated hairy vetch treatment relative to a bare soil treatment but were consistently lower in the live hairy vetch treatment relative to the desiccated or bare soil treatments. An average of 87% of sites under live hairy vetch compared to 8% of sites under desiccated hairy vetch transmitted less than 1% of unobstructed sunlight. The red (660 nm) to far-red (730 nm) ratio of transmitted light was reduced by 70% under live hairy vetch compared to 17% under desiccated hairy vetch. Daily maximum soil temperature and diurnal soil temperature amplitude were reduced by live hairy vetch > desiccated hairy vetch > bare soil. Soil moisture content was greater under both live and desiccated hairy vetch compared to bare soil during droughty periods. Changes in light extinction, red to far-red ratio, and diurnal soil temperature amplitude were sufficient to explain greater weed suppression by live than desiccated hairy vetch.
Herbicide Tolerance and Weed Control in Sethoxydim-Tolerant Corn (Zea mays)
Authors: Dotray Peter A. , Marshall Lorelei C. , Parker William B. , Wyse Donald L. , Somers David A. , Gengenbach Burle G.
Published: May 2019

Homozygous, sethoxydim-tolerant corn was field tested at two locations in 1989 and 1990. Sethoxydim at 0.22, 0.44, and 0.88 kg ha−1was applied to sethoxydimtolerant corn in the 3- and 7-leaf stages. None of the sethoxydim treatments caused visible injury to the sethoxydim-tolerant corn, but all treatments were lethal to a parental corn line used as a control. Sethoxydim applied at either stage of corn development had no effect on number of days to 50% silk emergence, plant height, or grain yield, compared to nontreated plants. Sethoxydim-tolerant corn was also tolerant to mixtures of sethoxydim plus other postemergence herbicides that control dicotyledonous weeds. Sethoxydim mixed with atrazine or sethoxydim applied in sequential applications with dicamba or 2,4-D gave annual grass control similar to sethoxydim applied alone. However, the sethoxydim plus bentazon treatment resulted in reduced grass control in comparison to sethoxydim alone. When the broadleaf herbicides were mixed with sethoxydim or applied as sequential treatments, broadleaf weed control was the same as when the broadleaf herbicides were applied alone. The high level of corn tolerance to sethoxydim and the broad spectrum of weed control resulting from combinations of sethoxydim plus other postemergence herbicides indicates that sethoxydim-tolerant corn hybrids could increase the options available for weed control in corn.
Control of Triazine-Resistant Kochia (Kochia scoparia) in Conservation Tillage Corn (Zea mays)
Authors: Wicks Gail A. , Martin Alex R. , Mahnken Garold W.
Published: May 2019

Triazine-resistant (TR) kochia control with herbicides was evaluated in the greenhouse and in the field on ridge-till and ecofallow corn. In the greenhouse, bromoxynil, dicamba, linuron, and paraquat applied POST controlled TR kochia > 86%. Control of TR kochia with 2,4-D ester at 0.3 kg ae ha−1varied with kochia biotype. In three ridge-till fields in 1985, atrazine plus fluorochloridone at 2.2 plus 0.6 kg ai ha−1applied before planting plus a layby cultivation was the only treatment that reduced TR kochia biomass to < 750 kg ha−1. In 1986, atrazine plus dicamba at 2.2 plus 0.3 kg ha−1, atrazine plus fluorochloridone at 2.2 plus 0.3 or 0.6 kg ha−1applied EPOST; atrazine at 2.2 kg ha−1applied EPOST followed by an MPOST application of bromoxynil at 0.3 or 0.4 kg ha−1, or dicamba plus 2,4-D ester at 0.3 plus 0.3 kg ha−1; and an MPOST application of atrazine plus dicamba at 1.3 plus 0.5 kg ha−1, atrazine plus pyridate at 1.1 plus 1.0 kg ai ha−1, or pyridate plus cyanazine at 1.0 plus 1.7 kg ai ha−1followed by a layby cultivation reduced kochia biomass to < 400 kg ha−1. In ecofallow corn, the only herbicide treatment that consistently controlled TR kochia > 95% 21 to 30 d after application was pyridate plus fluorochloridone at 1.0 plus 0.6 kg ha−1. Other treatments were less effective because kochia was too large or additional kochia emerged after application. When added to atrazine plus cyanazine, paraquat at 0.3 kg ai ha−1plus dicamba was more effective than paraquat plus 2,4-D ester or paraquat alone in controlling TR kochia.
Inhibition of Plant Acetolactate Synthase by Nicosulfuron, Rimsulfuron, and Their Mixture DPX-79406
Authors: Mekki Mounir , Leroux Gilles D.
Published: May 2019

Nicosulfuron and rimsulfuron are two selective postemergence sulfonylurea herbicides commercialized, respectively, in Europe and USA for weed control in maize. They are under development in Canada as a 1:1 premix (DPX-79406). The objective of the present study was to investigate the effects of these herbicides and their interactions on acetolactate synthase (ALS) activity of selected annual weed species. Each nicosulfuron and rimsulfuron treatment used over a concentration range of 0.01 to 10 μM produced a distinct pattern of ALS inhibition for common ragweed, proso millet, redroot pigweed, smooth crabgrass, and wild oats. Based on ALS specific activity, I50values for each herbicide differed slightly among the five weed species. However, rimsulfuron was much more inhibitory to ALS than was nicosulfuron. Common ragweed ALS activity increased linearly from 30 to 120 min, even in the continual presence of both herbicides in the assay buffer. This suggests the reversibility of their interaction with ALS. Delaying nicosulfuron (1 μM) or rimsulfuron (0.1 μM) additions to the assay buffer, after initiating the reaction with the enzyme, resulted in a quadratic increase of common ragweed ALS activity. In the continual presence of 0.1 μM of rimsulfuron, addition of 0.1 or 1 μM nicosulfuron did not affect ALS activity any further. However, in the continual presence of 0.1 μM of nicosulfuron, delaying rimsulfuron addition caused an increase in ALS activity. This increase was lower in the presence of 1 μM of nicosulfuron. Inhibition of common ragweed ALS by nicosulfuron and rimsulfuron was not independent of each other, suggesting some competition between the two herbicides for a common binding site on ALS.