bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation towards agile software product line engineering in large companies: A literature review
Authors: Klünder Jil Ann‐Christin , Hohl Philipp , Prenner Nils , Schneider Kurt
Published: May 2019

Almost all companies struggle with software systems that are getting increasingly complex. Therefore, in particular large companies often use software product lines, which provide an efficient way to manage software reuse as well as the high complexity. However, software product lines seem to be too slow to react to changes. Agile development approaches promise to meet this demand. At the same time, integrating an agile approach is not always easy. Consequently, there is a need for a transformation model that supports the agile transformation without harming the benefits of software product lines.

In this paper, we present the results of a literature review regarding agile transformation in large software companies. Our results summarize the insights from 85 papers and present a list of 20 tasks and tasks that are recommended by several researchers to be considered during the transformation. On the basis of these results, we create an agile transformation model—the so‐called “agile hamburger”—that contains these tasks and preserves software product lines. Since the model is rather coarse grained and generic, we also support the adaption to different teams by presenting an assessment model tailored to the demands of the automotive domain.
Static analysis of Android Auto infotainment and on‐board diagnostics II apps
Authors: Mandal Amit Kr , Panarotto Federica , Cortesi Agostino , Ferrara Pietro , Spoto Fausto
Published: May 2019

Smartphone and automotive technologies are rapidly converging, letting drivers enjoy communication and infotainment facilities and monitor in‐vehicle functionalities, via on‐board diagnostics (OBD) technology. Among the various automotive apps available in playstores, Android Auto infotainment and OBD‐II apps are widely used and are the most popular choice for smartphone to car interaction. Automotive apps have the potential of turning cars into smartphones on wheels but can be also the gateway of attacks. This paper defines a static analysis that identifies potential security risks in Android infotainment and OBD‐II apps. It identifies a set of potential security threats and presents an actual static analyzer for such apps. It has been applied to most of the highly rated infotainment apps available in the Google Play store, as well as on the available open‐source OBD‐II apps, against a set of possible exposure scenarios. Results show that almost 60% of such apps are potentially vulnerable and that 25% pose security threats related to the execution of JavaScript. The analysis of the OBD‐II apps shows possibilities of severe controller area network injections and privacy violations, because of leaks of sensitive information.
c-Met Signaling Is Essential for Mouse Adult Liver Progenitor Cells Expansion After Transforming Growth Factor-β-Induced Epithelial–Mesenchymal Transition and Regulates Cell Phenotypic Switch
Authors: Almalé Laura , García-Álvaro María , Martínez-Palacián Adoración , García-Bravo María , Lazcanoiturburu Nerea , Addante Annalisa , Roncero Cesáreo , Sanz Julián , López María , Bragado Paloma , Mikulits Wolfgang , Factor Valentina M. , Thorgeirsson Snorri S. , Casal J. Ignacio , Segovia José-Carlos , Rial Eduardo , Fabregat Isabel , Herrera Blanca , Sánchez Aránzazu
Published: May 2019

Adult hepatic progenitor cells (HPCs)/oval cells are bipotential progenitors that participate in liver repair responses upon chronic injury. Recent findings highlight HPCs plasticity and importance of the HPCs niche signals to determine their fate during the regenerative process, favoring either fibrogenesis or damage resolution. Transforming growth factor-β (TGF-β) and hepatocyte growth factor (HGF) are among the key signals involved in liver regeneration and as component of HPCs niche regulates HPCs biology. Here, we characterize the TGF-β-triggered epithelial–mesenchymal transition (EMT) response in oval cells, its effects on cell fate in vivo, and the regulatory effect of the HGF/c-Met signaling. Our data show that chronic treatment with TGF-β triggers a partial EMT in oval cells based on coexpression of epithelial and mesenchymal markers. The phenotypic and functional profiling indicates that TGF-β-induced EMT is not associated with stemness but rather represents a step forward along hepatic lineage. This phenotypic transition confers advantageous traits to HPCs including survival, migratory/invasive and metabolic benefit, overall enhancing the regenerative potential of oval cells upon transplantation into a carbon tetrachloride-damaged liver. We further uncover a key contribution of the HGF/c-Met pathway to modulate the TGF-β-mediated EMT response. It allows oval cells expansion after EMT by controlling oxidative stress and apoptosis, likely via Twist regulation, and it counterbalances EMT by maintaining epithelial properties. Our work provides evidence that a coordinated and balanced action of TGF-β and HGF are critical for achievement of the optimal regenerative potential of HPCs, opening new therapeutic perspectives. Stem Cells  2019;37:1108–1118
Polycyclic Aromatic Hydrocarbons as Potential Building Blocks for Organic Solar Cells
Authors: Aumaitre Cyril , Morin Jean‐François
Published: May 2019

Since the discovery of graphene in the early 2000′s, polycyclic aromatic hydrocarbons (PAHs) have been resurrected and new synthetic tools have been developed to prepare unprecedented structures with unique properties. One application that has been overlooked for this class of molecules is organic solar cells (OSCs). In this account, we present the recent development in the preparation of moderate to low band gap PAHs that could potentially be used as semiconducting materials in OSCs. Our focus is directed toward all‐carbon PAHs as well as their polymeric analogs.
Why Humean Causation Is Extrinsic
Authors: Pallies Daniel ,   Philosophy Documentation Center
Published: May 2019

According to a view that goes by “Humeanism,” causal facts supervene on patterns of worldly entities.The simplest form of Humeanism is the constant conjunction theory: a particular type-F thing causes a particular type-G thing iff (i) that type-F is conjoined with that type-G thing and (ii) all F’s are conjoined with G’s. The constant conjunction theory implies that all causation is extrinsic, in the following sense: for all positive causal facts pertaining to each possible region, it’s extrinsic to that region that those causal facts pertain to it. Actual Humeans don’t accept the constant conjunction theory; they accept more sophisticated versions of Humeanism. But I argue that they, too, are committed to the thesis that all causation is extrinsic. In arguing for this claim, I use a discussion from Brian Weatherson as a springboard. Weatherson argues that on a plausible Humean view, some regions are such that all of their possible duplicates have the same or similar natural laws. I show that this is false. If Humeanism is true, then for every possible region, there are possible duplicates of that region with utterly alien natural laws. As a consequence, no causal facts pertain intrinsically to any region.
Optical detection system for laser cooling and precision laser spectroscopy of relativistic highly charged ions at the CSRe
Authors: Wang Hanbing , Wen Weiqiang , Huang Zhongkui , Zhang Dacheng , Chen Dongyang , Zhao Dongmei , Zhu Xiaolong , Winters Danyal , Bussmann Michael , Ma Xinwen
Published: May 2019

Laser cooling and precision laser spectroscopy experiments of relativistic highly charged ions are being prepared at the heavy‐ion experimental cooler storage ring (CSRe). Optical detection of fluorescence photons, emitted from the laser‐excited ions, is extremely important for both powerful methods. In this paper, we briefly report on the current status of the existing optical detectors and also on their performance during laser cooling of relativistic Li‐like 16O5+ ion beams at the CSRe. In addition, we introduce the designs for our new optical detection systems, which have much higher photon detection efficiencies and can cover a much broader wavelength range. These detector systems will be used for the upcoming laser spectroscopy experiment of Li‐like 16O5+ ions, as well as for future laser spectroscopy experiments with other highly charged ions.
Enrichment factors for clinical trials in mild‐to‐moderate Alzheimer's disease
Authors: Ballard Clive , Atri Alireza , Boneva Neli , Cummings Jeffrey L. , Frölich Lutz , Molinuevo José Luis , Tariot Pierre N. , Raket Lars Lau
Published: May 2019

Introduction

Heterogeneity of outcomes in Alzheimer's disease (AD) clinical trials necessitates large sample sizes and contributes to study failures. This analysis determined whether mild‐to‐moderate AD populations could be enriched for cognitive decline based on apolipoprotein (APOE) ε4 genotype, family history of AD, and amyloid abnormalities.

Methods

Modeling estimated the number of randomized patients needed to detect a 2‐point treatment difference on the AD Assessment Scale–Cognitive subscale using placebo data from three randomized, double‐blind trials (ClinicalTrials.gov Identifiers: NCT01955161, NCT02006641, and NCT02006654).

Results

An 80% power to detect a 2‐point treatment effect required the randomization of 148 amyloid‐positive patients; 178 ε4 homozygous or amyloid‐positive patients; and 231 ε4 homozygous, family history‐positive, or amyloid‐positive patients, compared with 1619 unenriched patients (per arm).

Discussion

Enrichment in mild‐to‐moderate AD clinical trials can be achieved using combinations of biomarkers/risk factors to increase the likelihood of observing potential treatment effects.
Against epistemic pessimism about moral testimony
Authors: McShane Paddy Jane
Published: May 2019

My aim in this paper is to argue against what I call “epistemic” pessimism about moral testimony. Epistemic pessimists argue that moral testimony fails to transmit epistemic warrant as non-moral testimony does. I reject epistemic pessimism by defending theNo Difference Thesis, that there is no in principle difference between the transmission of epistemic warrant by moral and non-moral testimony. The main thrust of my argument is that there is a goodprima faciecase to be made for the thesis, namely, that it is supported by all of the major current epistemological views of testimonial warrant, both reductionist and non-reductionist. After making this case, I consider five pessimist attempts to undermine theNo Difference Thesis, and argue that none of these attempts succeeds. So, in the absence of any other compelling criticisms, we are justified in rejecting epistemic pessimism and accepting theNo Difference Thesis.
On the departure of near-wall turbulence from the quasi-steady state
Authors: Agostini Lionel , Leschziner Michael
Published: May 2019

An examination is undertaken of the validity and limitations of the quasi-steady hypothesis of near-wall turbulence. This hypothesis is based on the supposition that the statistics of the turbulent fluctuations are universal if scaled by the local, instantaneous, wall shear when its variations are determined from footprints of large-scale, energetic, structures that reside in the outer part of the logarithmic layer. The examination is performed with the aid of direct numerical simulation data for a single Reynolds number, which are processed in a manner that brings out the variability of locally scaled statistics when conditioned on the local value of the wall friction. The key question is to what extent this variability is insignificant, thus reflecting universality. It is shown that the validity of the quasi-steady hypothesis is confined, at best, to a thin layer above the viscous sublayer. Beyond this layer, substantial variations in the conditioned shear-induced production rate of large-scale turbulence cause substantial departures from the hypothesis. Even within the wall-proximate layer, moderate departures are provoked by large-scale distortions in the conditioned strain rate that result in variations in small-scale production of turbulence down to the viscous sublayer.
Policies based on mandatory employment quotas for disabled workers: the case of Italy
Authors: Agovino Massimiliano , Marchesano Katia , Garofalo Antonio
Published: May 2019

This article examines the Italian policy framework on the employment of disabled people. It discusses the strengths and limitations of Law 68 of 12 March 1999 (Regulation on the right to work of disabled people). Despite it having been enacted 16 years after being passed, Law 68/99 still faces problems in its implementation. The data analysis shows the propensity of firms to flout their obligations with regard to the recruitment of disabled people, preferring instead the risk of being sanctioned. In order for Law 68/99 to have a positive effect on the employment of disabled people, higher incentives (including subsidies for labour costs) must be introduced for employers, especially to enable the adaptation and adjustment of the workplace. With these inducements, firms would be encouraged to recruit disabled people and avoid penalties. In addition, disability management policies (still rarely implemented in the Italian workplace) and comprehensive training programmes can play a crucial role in overcoming discriminatory constraints regarding skills and physical ability, so as to increase the employability of disabled people in the labour market.
List Experiments with Measurement Error
Authors: Blair Graeme , Chou Winston , Imai Kosuke
Published: May 2019

Measurement error threatens the validity of survey research, especially when studying sensitive questions. Although list experiments can help discourage deliberate misreporting, they may also suffer from nonstrategic measurement error due to flawed implementation and respondents’ inattention. Such error runs against the assumptions of the standard maximum likelihood regression (MLreg) estimator for list experiments and can result in misleading inferences, especially when the underlying sensitive trait is rare. We address this problem by providing new tools for diagnosing and mitigating measurement error in list experiments. First, we demonstrate that the nonlinear least squares regression (NLSreg) estimator proposed in Imai (2011) is robust to nonstrategic measurement error. Second, we offer a general model misspecification test to gauge the divergence of theMLregandNLSregestimates. Third, we show how to model measurement error directly, proposing new estimators that preserve the statistical efficiency ofMLregwhile improving robustness. Last, we revisit empirical studies shown to exhibit nonstrategic measurement error, and demonstrate that our tools readily diagnose and mitigate the bias. We conclude this article with a number of practical recommendations for applied researchers. The proposed methods are implemented through an open-source software package.
Extraction of Dissolved Organic Carbon from Glacier Ice for Radiocarbon Analysis
Authors: Fang L , Schindler J , Jenk T M , Uglietti C , Szidat S , Schwikowski M
Published: May 2019

Alpine glaciers are valuable archives for the reconstruction of human impact on the environment. Besides dating purposes, measurement of radiocarbon (14C) content provides a powerful tool for long-term source apportionment studies on the carbonaceous aerosols incorporated in ice cores. In this work, we present an extraction system for14C analyses of dissolved organic carbon (DOC) in ice cores. The setup can process ice samples of up to 350 g mass and offers ultra-clean working conditions for all extraction steps. A photo-oxidation method is applied by means of external UV irradiation of the sample. For an irradiation time of 30 min with catalyzation by addition of Fe2+and H2O2, we achieve an efficiency of 96 ± 6% on average. Inert gas working conditions and stringent decontamination procedures enable a low overall blank of 1.9 ± 1.6 μg C with a F14C value of 0.68 ± 0.13. This makes it possible to analyze the DOC in ice samples with a carbon content of as low as 25 μg C kg−1ice. For a first validation, the new method was applied to ice core samples from the Swiss Alps. The average DOC concentration and F14C values for the Fiescherhorn ice core samples show good agreement with previously reported data for the investigated period of 1925–1936 AD.
Editor's Note
Authors: Trooboff Peter D.
Published: May 2019

For the past 7 years, Monroe Leigh has edited this section with the able assistance of his associates at Steptoe & Johnson. His fine eye for accuracy and his fairness remain as standards for “his successors. The Journal acknowledges its great debt to him and to his firm.
Molding the Model Bishop from Trent to Vatican II
Authors: McNamara Celeste
Published: May 2019

The creation of new saints often has a political edge; the Catholic Church molds saints’ lives to fit its needs, and individual popes have particular priorities in saint-making. In the early modern Church, this was particularly important after the Council of Trent. The Tridentine decrees (1563) instructed bishops to reform the Church but provided few practical suggestions for how to do this. One solution was to hold up exemplary post-Tridentine bishops as models through beatification and canonization. Historians have noted the importance of model bishops but have not fully considered the process of creating them and its implication for the histories of Catholic Reform and of canonization. The case of Cardinal-Bishop Gregorio Barbarigo of Padua (bp. 1664–1697) tells a complicated and interesting story about the intersection of Catholic Reform and canonization. Barbarigo was beatified in 1761 during the Catholic Enlightenment and was finally canonized in 1960, on the eve of the Second Vatican Council. Examining the construction of his image from 1699–1960, this article argues that the Catholic Church in both the eighteenth and the twentieth centuries molded Barbarigo into the model bishop needed at those particular times, in response to the issues facing contemporary bishops and clergy.
The Melancholy Saint: Jonathan Edwards's Interpretation of David Brainerd as a Model of Evangelical Spirituality
Authors: Weddle David L.
Published: May 2019

It often happens that the papers of a departed master are gathered and winnowed by a faithful disciple in search of one last harvest of truth: an act of respect mingled with a desire for reflected glory. But in Jonathan Edwards's editing of the diary of David Brainerd the elder served the younger.
Symbolic Eschatology and the Apocalypticism of Q
Authors: Kloppenborg John S.
Published: May 2019

The relationship of the preaching and teaching of Jesus to apocalyptic has been a vexed one ever since Albert Schweitzer's assault on the liberal “Lives of Jesus” and his advocacy of consistent eschatology along with his characterization of Jesus’ teachings as interim ethics. While many of the details of Schweitzer's hypothesis failed to be persuasive, his insistence that Jesus’ activity be seen in the context of apocalypticism has made a profound impact on subsequent historical Jesus scholarship and, in spite of his own noncommital stance with regard to the Two Document Hypothesis, on the theological characterization of Q.
The Origin of the Designation of Jesus as “Son of Man”
Authors: Collins Adela Yarbro
Published: May 2019

Taking up this well worked problem in New Testament scholarship may seem audacious to some, futile to others. At least one scholar has exulted over his own claim, supported by a few, to have solved the problem; whereas at least one other scholar has declared the problem insoluble. Although the problem is difficult, the elements of a solution are indeed present in the discussion. It is taken up again in this essay because of its importance for research on the historical Jesus and on the emergence of Christology.
Halakhic Leniency in Modern Responsa Regarding Conversion
Authors: Shilo Shmuel
Published: May 2019

The process of conversion to Judaism is paralleled to the acceptance of the Torah by the Jewish people at Sinai. In Jewish sources, the Sinaitic experience is viewed as a mass conversion of the Jewish people. The essence of this conversion was the acceptance of the commandments as binding upon the Jewish people. Similarly, the essence of a Gentile's conversion to Judaism in later generations, is his acceptance of the yoke of the commandments as binding upon him. In fact, the Talmudic sources go so far as to state that the Jewish people at Sinai underwent the same process as a proselyte: circumcision, immersion in amikveand the bringing of a burnt-offering. In short, traditionally, the essence of conversion was the acceptance of themitzvot.
Carnival at Luanda
Authors: Birmingham David
Published: May 2019

The tradition of carnival-type street festivals and competitive dance troupes appears to be an old one in Luanda. In 1620, at the end of the most serious round of slave wars in Angola's history, political allegory and mimicry were included in the street processions celebrating the canonization of Saint Francis Xavier. In the nineteenth century the Creole community regularly adapted its public ceremonials to the shifting political and religious climate. In the age of white settlement, during the middle decades of the twentieth century, ‘native’ dance troops were officially encouraged until their potential nationalism was discerned. After independence, government tried to revive carnival for its own ends and according to its own calendar of state ceremonial. At one level the carnival continued to exorcise the fear of authority among the powerless. At another the political dimension was eclipsed by the competitive rivalries of local communities seeking identity and prestige. The structures continued to use the old ritual patterns of leadership with kings, queens, commanders and soldiers. Economic influence continued to be wielded by the great fishing families who invested important resources into conspicuous clothing and ceremonial feasting as they had done for centuries. The spectators responded at many different levels of appreciation.
Effect of docking and shearing on growth and carcass traits of fat-tailed Ossimi sheep
Authors: Marai I. F. M. , Nowar M. S. , Bahgat Layla B. , Owen J. B.
Published: May 2019

Thirty Ossimi lambs were used in an experiment to compare those whose tail was docked shortly after birth with controls. After weaning at 4 months of age the groups were further subdivided and two of the four groups closely shorn according to a 2 × 2 factorial design.

Male lambs at 20 kg were subjected to intensive finishing until the age of 50 weeks and nine were then slaughtered to determine carcass characteristics.

There was a trend for increased live-weight gain in the docked lambs in the preweaning stage (up to 16 weeks).

This trend was also present, although not statistically significant, in the final phase of intensive feeding from 20 kg weight to 50 weeks. Shearing significantly improved daily gain in this final period (P < 0·05). These increases in gain were also apparently associated with improvements in efficiency, as judged on a group basis.

Docking and shearing also tended to cause increases in body measurements: height, chest girth and abdomen girth in the case of docking (P < 0·05) and chest girth, chest depth and abdomen girth in the case of shearing (P < 0–05).

Carcass characteristics, measured on a relatively small sample, indicated several effects of docking and shearing on carcass traits although most of these were consistent with the expected differences stemming from the higher carcass weights acheived at 50 weeks of age by docked and sheared lambs.
Systematics and Paleoecology of Norian (Late Triassic) Bivalves from a Tropical Island Arc: Wallowa Terrane, Oregon
Authors: Newton Cathryn R. , Whalen Michael T. , Thompson Joel B. , Prins Nienke , Delalla David
Published: May 2019

Early Norian silicified bivalves from Hells Canyon in the Wallowa terrane of northeastern Oregon are part of a rich molluscan biota associated with a tropical island arc. The Hells Canyon locality preserves lenses of silicified shells formed as tempestites in a shallow subtidal carbonate environment. These shell assemblages are parautochthonous and reflect local, rather than long-distance, transport. Silicification at this locality involved small-scale replacement of original calcareous microstructures, or small-scale replacement of neomorphosed shells, without an intervening phase of moldic porosity. This incremental replacement of carbonate by silica contrasts markedly with void-filling silicification textures reported previously from silicified Permian bivalve assemblages.

The bivalve paleoecology of this site indicates a suspension feeding biota existing on and within the interstices of coral-spongiomorph thickets, and inhabiting laterally adjacent substrates of peloidal carbonate sand. The bivalve fauna is ecologically congruent with the reef-dwelling molluscs associated with Middle Triassic sponge-coral buildups in the Cassian Formation of the Dolomites (Fuersich and Wendt, 1977). Hells Canyon is a particularly important early Norian locality because of the diversity of substrate types and because the site includes many first occurrences of bivalves in the North American Cordillera. These first occurrences include the first documentation of the important epifaunal families Pectinidae and Terquemiidae in Triassic rocks of the North American Cordillera.

The large number of biogeographic and geochronologic range extensions discovered in this single tropical Norian biota indicates that use of literature-based range data for Late Triassic bivalves may be very hazardous. Many bivalve taxa formerly thought to have gone extinct in Karnian time have now been documented from Norian strata in this arc terrane. These range extensions, coupled with the high bivalve species richness of the Hells Canyon site, suggest that the Karnian mass extinction in several literature-based compilations may be an artifact of incomplete sampling. Even for the Norian, present compilations of molluscan extinction may have an unacceptably large artifactual component.

Thirty-five bivalve taxa from the Hells Canyon locality are discussed. Of these, seven are new: the mytilidMysidiella cordilleranan. sp., the limaceanAntiquilima vallierin. sp., the true oysterLiostrea newellin. sp., the pectinaceanCrenamussium concentricumn. gen. and sp., the unioidCardinioides josephusn. sp., the trigoniaceanErugonia canyonensisn. gen. and sp., and the carditaceanPalaeocardita silberlingin. sp.
Tokamak parameter regimes with low toroidal momentum diffusivity
Authors: McMillan B. F. , Dominski J.
Published: May 2019

The strong, sharp flow structures that are seen frequently in tokamak cores, and large amplitude spontaneous global toroidal rotation are both surprising in light of current theories where toroidal flow evolution is dominantly diffusive. Mechanisms for spontaneously generating strong poloidal shear flows have been extensively investigated, but these processes were thought not to apply to toroidal flows. We confirm, however, that there is a regime with near-zero toroidal momentum diffusivity, where toroidal flow structures are spontaneously generated, as shown in earlier global gyrokinetic simulations. This allows strong rotation with negligible applied external torque, and the regime where this occurs is also favourable for strong turbulence stabilisation by rotation. The transition to low momentum diffusivity occurs for tight aspect ratio, low safety factor and at low levels of heat flux, in agreement with a simple zero-dimensional model for the flow–turbulence interaction.
The Effect of Site of Application of14C-Fluazifop on Its Uptake and Translocation by Quackgrass (Agropyron repens)
Authors: Chandrasena Nimal R. , Sagar Geoff R.
Published: May 2019

The effect of site of application on uptake and translocation of the butyl ester of fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy] phenoxy] propanoic acid} by quackgrass [Agropyron repens(L.) Beauv. # AGRRE] was investigated using14C-labeled herbicide and intact plants. Uptake and distribution of the label were significantly greater from the abaxial than from the adaxial surface of leaves. The addition of a nonionic surfactant4to the treatment solution increased the uptake significantly only through the adaxial surface. Uptake of14C by the apical, middle, and basal regions of the treated leaf lamina did not differ significantly. However, movement of the14C-label to stem areas and leaves both above and below treated leaves was greater from lamina base applications than from treatments to the lamina apex and middle. The older leaves absorbed more herbicide than did younger leaves, but the pattern of translocation did not differ. Considerably greater translocation occurred from treatments to the outside of the leaf sheaths in the lower regions of the stem than from applications to the upper leaf sheaths, with the14C-label moved to young and old leaves, roots, and rhizomes. Uptake from applications to the outside of the upper leaf sheaths also resulted in improved translocation mainly within the stem areas and into upper leaves.
Artemisinin, a Constituent of Annual Wormwood (Artemisia annua), is a Selective Phytotoxin
Authors: Duke Stephen O. , Vaughn Kevin C. , Croom Edward M. , Elsohly Hala N.
Published: May 2019

Artemisinin (qinghaosu), a sesquiterpenoid lactone peroxide constituent of annual wormwood (Artemisia annuaL. # ARTAN) that is used as an antimalarial drug, was tested for phytotoxic properties. It inhibited germination of lettuce (Lactuca sativaL.) and annual wormwood, and growth of roots and shoots of lettuce, redroot pigweed (Amaranthus retroflexusL. # AMARE), pitted morningglory (Ipomoea lacunosaL. # IPOLA), annual wormwood, and common purslane (Portulaca oleraceaL. # POROL) was inhibited at 33 μM. No effects of 33 μM artemisinin were detected on growth of velvetleaf (Abutilon theophrastiMedik. # ABUTH) and grain sorghum [Sorghum bicolor(L.) Moench.]. Chlorophyll content was not affected in lettuce, and chlorosis was not observed in any species tested. The probable biosynthetic precursors of artemisinin, arteannuin B and qinghao acid, had no effect on growth or chlorophyll content of lettuce; however, they inhibited lettuce seed germination. Artemisinin and cinmethylin {exo-1-methyl-4-(1-methylethyl)-2-[(2-methylphenyl)methoxy]-7-oxabicyclo [2.2.1] heptane} were equally effective in reducing growth of lettuce; however, cinmethylin had no effect on germination. Respiration of lettuce roots or cotyledons was not inhibited by artemisinin. Artemisinin only marginally increased the mitotic index of lettuce root tips at 33 μM. At the ultrastructural level, however, chromosomes were less condensed during mitosis in artemisinin-treated than control meristematic cells. The growth-inhibiting ability of artemisinin could not be reduced by feeding the plants with hydrolyzed protein or treatment with putrescine. Artemisinin is a selective phytotoxin that reduces growth by a mechanism other than mitotic disruption or inhibition of protein synthesis.
Seed Viability and Dormancy of 17 Weed Species After 21 Months in Alaska
Authors: Conn Jeffery S. , Farris Martha L.
Published: May 2019

A 50-yr buried-seed study was initiated at Fairbanks, AK, in 1984. Seed of 17 weed species important in Alaskan agriculture were collected and buried 2 and 15 cm deep. Seed viability was determined initially and after recovery from the soil through a combination of germination tests and 2,3,5-triphenyltetrazolium chloride (TTC) treatments. Seed exhumed at 9 and 21 months were tested for viability and dormancy. Burial depth had a significant effect on seed longevity of corn spurry (Spergula arvensisL. # SPRAR), wild oats (Avena fatuaL. # AVEFA), pineappleweed [Matricaria matricarioides(Less.) C. L. Porter # MATMT], and bluejoint reedgrass [Calamagrostis canadensis(Michx.) Nutt.]. Viability was higher for seed buried at 15 than at 2 cm. Viability of shepherdspurse [Capsella bursapastoris(L.) Medik. #CAPBP] and pineappleweed seed did not decrease significantly over the 21-month burial period. In contrast, seed viability of wild buckwheat (Polygonum convolvulusL. # POLCO), common hempnettle (Galeopsis tetrahitL. # GAETE), wild oats, quackgrass [Agropyron repens(L.) Beauv. # AGRRE], and foxtail barley (Hordeum jubatumL. # HORJU) was less than 11% at the end of 21 months. There was no significant relationship between initial seed dormancy and viability after 21 months of burial.
Herbicide Dissipation from Soils with Different Herbicide use Histories
Authors: Harvey R. Gordon
Published: May 2019

Herbicide dissipation was monitored in soils differing in herbicide use histories. Repeated annual applications over 5 yr enhanced biodegradation of butylate [S-ethyl bis(2-methylpropyl)carbamothioate] and EPTC (S-ethyl dipropylcarbamothioate) but not alachlor {2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide}, atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine], cyanazine {2-[[(4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile}, or metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide]. Prior application of butylate or EPTC enhanced biodegradation of the other thiocarbamate herbicide but not alachlor, atrazine, cyanazine, or metolachlor. Prior application of alachlor, atrazine, cyanazine, metolachlor, or trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] did not enhance biodegradation of butylate or EPTC. Dissipation of EPTC applied with dietholate (O,O-diethyl-O-phenolphosphorothioate) was not enhanced by prior application of alachlor, atrazine, or trifluralin. Prior use of EPTC, EPTC + dietholate, butylate, or cycloate, respectively, enhanced biodegradation of EPTC in 100, 100, 71, and 50% of the experiments, of EPTC applied with dietholate in 57, 100, 60, and 33% of the experiments, of butylate in 33, 40, 100, and 20% of the experiments, and of cycloate in 0, 0, 17, and 0% of the experiments. Prior thiocarbamate herbicide applications usually did not enhance cycloate biodegradation, but soils from two locations without prior pesticide use histories rapidly degraded the herbicide. Storage of soil samples at 25 C for 6 or 12 months before application of EPTC and EPTC + dietholate resulted in less herbicide degradation than storage at 15 C. Differences in prior environmental conditions such as temperature may explain why development of enhanced biodegradation varied between years even in the same field plots.
Canada Thistle (Cirsium arvense) Propagation from Stem Sections
Authors: Magnusson Mark U. , Wyse Donald L. , Spitzmueller Joseph M.
Published: May 2019

Field experiments were conducted to determine whether aerial and subterranean stem sections taken from Canada thistle [Cirsium arvense (L.) Scop. # CIRAR] plants in four stages of development (spring-vegetative, bud, postbloom, and fall-vegetative) could survive and produce infestations the following year. Partially buried aerial stem sections from all stages of development had greater survival 28 days after planting than completely buried aerial stem sections. Few completely buried aerial stem sections survived. Partially or completely buried subterranean stem sections from Canada thistle at the postbloom stage had the highest survival rate. Few partially or completely buried subterranean stem sections from the other three growth stages survived. Surviving stem sections from spring-vegetative, bud, and postbloom stages of Canada thistle produced adventitious roots that overwintered and produced new infestations the following spring. Surviving stem sections from Canada thistle at the fall-vegetative stage did not develop an adequate root system for winter survival.
Effects of Giant Burreed (Sparganium eurycarpum) and Shade on Wild Rice (Zizania palustris)
Authors: Clay Sharon A. , Oelke Ervin A.
Published: May 2019

Studies were conducted at Grand Rapids, MN, to determine the effect of giant burreed (Sparganium eurycarpumEngelm. # SPGEU) planted at 6, 12, and 24 corms/m2on wild rice (Zizania palustrisL. ‘K2′) growth and yield. Giant burreed, a spreading perennial, had shoot densities of 21, 29, and 42/m2at harvest for the 6, 12, and 24 corms/m2treatments, respectively. Wild rice yield and panicle number were reduced approximately 60% when giant burreed shoot density was 40/m2or higher when compared to the weed-free control. Giant burreed did not interfere with nutrient uptake of wild rice on a whole-plant basis, and increased N fertilizer application did not reduce losses in dry weight. Giant burreed reduced penetration of photosynthetically active radiation (PAR) from 2 to 35% in the wild rice canopy from the early tillering to the anthesis stage of wild rice development. In growth chamber studies, wild rice dry weight and panicle number were reduced by 46 and 65%, respectively, when wild rice was shaded for 12 weeks and compared to a full light treatment. Reduction of PAR penetration into the wild rice canopy appears to be the major mechanism of giant burreed interference with wild rice.
Factors Affecting Timothy (Phleum pratense) Yield Loss Due to Weeds
Authors: Lemieux Claudel , Watson Alan K. , Deschenes Jean-Marc
Published: May 2019

Data obtained from two experiments were used to identify and describe factors affecting crop loss due to weeds in forage stands. Timothy (Phleum pratenseL. ‘Champ′) was established in presence or absence of barley (Hordeum vulgareL. ‘Bruce′), red clover (Trifolium pratenseL. ‘Florex′), broadleaf weeds, and grass weeds. Botanical composition, soil water, soil nutrients, light interception, and plant cover were determined 4 and 6 weeks after seeding, and crop yield was determined at periodic forage harvest dates. Principal components analyses permitted the extraction of 12 factors and regression analyses demonstrated that these factors can be used to describe crop yield. Each factor can be estimated either by obtaining the rotated factor scores or by selecting a representative variable that can be substituted for the rotated factor scores in the regression models. The approach described in this paper should be tested with other crops and other weed complexes. It is suggested to use weed density in combination with weed and crop cover data to predict crop loss.
Economics of Weed Control in Peanuts (Arachis hypogaea) with Herbicides and Cultivations
Authors: Wilcut John W. , Wehtje Glenn R. , Walker Robert H.
Published: May 2019

The effectiveness and profitability of weed control with herbicides and cultivation were determined in peanuts (Arachis hypogaeaL. ‘Florunner′) infested with Texas panicum (Panicum texanumBuckl. # PANTE), sicklepod (Cassia obtusifoliaL. # CASOB), and pitted morningglory (Ipomoea lacunosaL. # IPOLA). Highest peanut yield (4260 kg/ha) and net returns were achieved in 2 of 3 yr with benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine] applied preplant incorporated followed by alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide] and dinoseb [2-(1-methylpropyl)-4,6-dinitrophenol] plus naptalam {2-[(1-naphthalenylamino)carbonyl] benzoic acid} applied at ground cracking, with two timely cultivations. Systems utilizing herbicides alone did not provide highest net returns, peanut yield, or weed control.
Effects of Carbon Dioxide Enrichment on the Growth and Morphology of Kudzu (Pueraria lobata)
Authors: Sasek Thomas W. , Strain Boyd R.
Published: May 2019

Kudzu (Pueraria lobataOhwi # PUELO) was grown from seeds in controlled-environment chambers at 350, 675, or 1000μl·1−1CO2. Biomass and leaf area production, morphological characteristics, and growth analysis components were determined at 14, 24, 45, and 60 days after emergence. At 60 days, plants grown at 1000μl·1−1CO2had 51% more biomass, 58% longer stems, and 50% more branches than plants grown at 350μl·1−1CO2. Plants grown at 675μl·1−1CO2were intermediate. Growth analysis components indicated that CO2enrichment increased growth by compounding effects due to increased net assimilation rates and increased leaf area duration. Relative growth rates were not significantly affected. The large CO2-induced increase in stem height versus stem diameter is in marked contrast to previously reported responses of woody erect growth forms. Possible ecological implications for competitive abilities are discussed.
Movement and Germination of Weed Seeds in Ridge-Till Crop Production Systems
Authors: Forcella Frank , Lindstrom Michael J.
Published: May 2019

The dynamics of buried weed seeds in ridge-tilled corn (Zea maysL.) and soybeans [Glycine max(L.) Merr.] were studied in Minnesota. Soils subjected to continuous corn production harbored at least twice as many buried weed seeds as soils under corn/soybean rotations. Truncation of ridges at the time of crop sowing removed 31 to 37% of the buried weed seeds from ridges of continuous corn, and 80 to 100% of those from ridges of the corn/soybean rotations. From 14 to 36% of weed seeds originally in ridges were lost through germination either on the ridge or in the furrow. Ridging soil at layby stimulated germination of numerous weed seeds. The resulting population of small weeds eventually produced up to 1000 seeds/m2in continuous corn but only about 100 seeds/m2in corn/soybean rotations, thoroughly replenishing the soil seed reserve in both cropping systems. After 7 to 8 yr of good to excellent weed control with herbicides, crop yield losses in the absence of herbicides were 10 to 27% in continuous corn, and 0% for corn and 6 to 10% for soybeans in corn/soybean rotations.
Glyphosate Activity in Potato (Solanum tuberosum) Under Different Temperature Regimes and Light Levels
Authors: Masiunas John B. , Weller Stephen C.
Published: May 2019

The response of potato (Solanum tuberosumL. 'Superior’) to glyphosate [N-(phosphonomethyl)glycine] at rates between 0.28 and 2.24 kg ae/ha was determined in four environments: 24/13 or 13/4 C temperature regimes with light levels of 650 ± 53 or 320 ± 45 μE · m−2· S−1. Light level did not affect phytotoxicity ratings or shoot fresh weight following glyphosate application. Greater phytotoxicity and reduced fresh weight accumulation were observed from glyphosate at rates above 0.56 kg/ha in a high-temperature regime than for comparable plants grown at low temperature. Studies of14C-glyphosate uptake and translocation indicated that the differences in phytotoxicity were due to less glyphosate absorption at low temperature and not a shift in distribution patterns within the plant.
Absorption, Translocation, and Metabolism of Acifluorfen and Lactofen in Pitted Morningglory (Ipomoea lacunosa) and Ivyleaf Morningglory (Ipomoea hederacea)
Authors: Higgins Jeffery M. , Whitwell Ted , Corbin Fredrick T. , Carter George E. , Hill Hoke S.
Published: May 2019

Experiments were conducted to determine14C absorption, translocation, and metabolism by pitted morningglory (Ipomoea lacunosaL. # IPOLA) and ivyleaf morningglory [Ipomoea hederacea(L.) Jacq. # IPOHE] foliarly treated with14C-acifluorfen [5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoic acid] or14C-lactofen [(±)-2-ethoxy-1-methyl-2-oxoethyl-5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-dinitrobenzoate]. Seventy-one to 84% of applied14C-acifluorfen was recovered in leaf water wash of ivyleaf morningglory compared to 32 to 46% from pitted morningglory. Sixty-four percent of applied14C-lactofen was recovered in leaf water wash 96 h after treatment in both morningglory species. Thirty-five to 37% more14C from applied14C-acifluorfen was found in pitted morningglory treated leaves than ivyleaf morningglory treated leaves. Less than 28% of applied14C-lactofen was extracted from treated leaves of either morningglory species. Translocation and metabolism of14C-acifluorfen and14C-lactofen were minimal in both morningglory species.
Water Relations in Quackgrass (Agropyron repens) Following Postemergence Herbicides
Authors: Trimmer Mark C. , Linscott Dean L.
Published: May 2019

In laboratory and field studies, quackgrass (Agropyron repens(L.) Beauv. # AGRRE) was subjected to postemergence applications of the butyl ester of fluazifop-P {(R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, methyl ester of haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid}, or ethyl ester of quizalofop {2-[4-[[6-(chloro-2-quinoxalinyl)oxy] phenoxy] propanoic acid}. Haloxyfop, fluazifop-P, and quizalofop each required a minimum of 1 week to reduce quackgrass transpiration or water uptake in the laboratory. At rates lower than 0.56 kg ae/ha, fluazifop-P reduced quackgrass transpiration and water usage less quickly and to a lesser extent than equivalent rates of haloxyfop and quizalofop. The time required for significant transpiration and water uptake reduction by herbicide-treated quackgrass was several days longer in the field than in the laboratory, but the reaction patterns among the herbicides were similar. Little if any benefit was obtained from sequential applications of the herbicides compared with single applications of the same total dosage. All three herbicides significantly reduced quackgrass dry weight.
Plant Responses to Haloxyfop as Influenced by Water Stress
Authors: Kidder Daniel W. , Behrens Richard
Published: May 2019

Green foxtail [Setaria viridis(L.) Beauv. # SETVI] and proso millet [Panicum miliaceum(L.) #PANMI] growing under high water stress for 3 days before + 3 days after foliar applications of the methyl ester of haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} developed less herbicide injury than plants growing under low water stress. There was a 32% reduction in the retention of haloxyfop sprays by proso millet when growing under high water stress than when growing under low water stress. Haloxyfop spray retention by green foxtail was not affected by the degree of water stress. The translocation of14C out of14C-haloxyfop-treated leaves was significantly greater in plants of both species when growing under low water stress than when growing under high water stress. The conversion of 98% of the absorbed14C-haloxyfop-methyl to14C-haloxyfop and unidentified polar metabolites occurred in both species within 12 h of application. The green foxtail growing under low water stress contained greater concentrations of14C-haloxyfop than did plants growing under high water stress. Levels of14C-haloxyfop were the same in proso millet growing under high and low water stress. The reduced injury of green foxtail and proso millet growing under high water stress from postemergence sprays of haloxyfop can be attributed to a reduction in herbicide translocation in both species, plus a reduction in spray retention by proso millet or changes in the metabolism of the herbicide in green foxtail, which results in a reduction in the concentration of haloxyfop.
Recovery of Pitted Morningglory (Ipomoea lacunosa) and Ivyleaf Morningglory (Ipomoea hederacea) Following Applications of Acifluorfen, Fomesafen, and Lactofen
Authors: Higgins Jeffery M. , Whitwell Ted , Murdock Edward C. , Toler Joe E.
Published: May 2019

Field experiments were conducted during 1985 and 1986 to determine the response of soybean [Glycine max(L.) Merr. ‘Coker 156’], pitted morningglory (Ipomoea lacunosaL. # IPOLA), and ivyleaf morningglory [Ipomoea hederacea(L.) Jacq. # IPOHE] to acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid}, fomesafen {5-[2-chloro-4-(trifluoromethyl) phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide}, and lactofen {(±)-2-ethoxy-1-methyl-2-oxoethyl-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-dinitrobenzoate}. Acifluorfen and lactofen were more phytotoxic to soybean 15 days after treatment (DAT) than fomesafen. All herbicides at low rates controlled 80% or more pitted morningglory. However, only the high rates (0.6 kg ai/ha) of acifluorfen and fomesafen controlled 80% or more ivyleaf morningglory 90 DAT. Full-season competition from untreated pitted morningglory reduced soybean seed yields 44 and 22% in 1985 and 1986, respectively, compared to 58 and 49% with untreated ivyleaf morningglory. Soybean seed yields were higher in plots receiving acifluorfen or fomesafen applications than lactofen applications.