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Southern crabgrass [Digitaria ciliaris (Retz.) Koeler] is an annual grass weed that commonly infests turfgrass, roadsides, wastelands, and cropping systems throughout the southeastern United States. Two biotypes of D. ciliaris (R1 and R2) with known resistance to cyclohexanediones (DIMs) and aryloxyphenoxypropionates (FOPs) previously collected from sod production fields in Georgia were compared with a separate susceptible biotype (S) collected from Alabama for the responses to pinoxaden and to explore the possible mechanisms of resistance. Increasing rates of pinoxaden (0.1 to 23.5 kg ha−1) were evaluated for control of R1, R2, and S. The resistant biotypes, R1 and R2, were resistant to pinoxaden relative to S. The S biotype was completely controlled at rates of 11.8 and 23.5 kg ha−1, resulting in no aboveground biomass at 14 d after treatment. Pinoxaden rates at which tiller length and aboveground biomass would be reduced 50% (I50) and 90% (I90) for R1, R2, and S ranged from 7.2 to 13.2 kg ha−1, 6.9 to 8.6 kg ha−1, and 0.7 to 2.1 kg ha−1, respectively, for tiller length, and 7.7 to 10.2 kg ha−1, 7.2 to 7.9 kg ha−1, and 1.6 to 2.3 kg ha−1, respectively, for aboveground biomass. Prior selection pressure from DIM and FOP herbicides could result in the evolution of D. ciliaris cross-resistance to pinoxaden herbicides. Amplification of the carboxyl-transferase domain of the plastidic ACCase by standard PCR identified a point mutation resulting in an Ile-1781-Leu amino acid substitution only for the resistant biotype, R1. Further cloning of PCR product surrounding the 1781 region yielded two distinct ACCase gene sequences, Ile-1781 and Leu-1781. The amino acid substitution, Ile-1781-Leu in both resistant biotypes (R1 and R2), however, was revealed by next-generation sequencing of RNA using Illumina platform. A point mutation in the Ile-1781 codon leading to herbicide insensitivity in the ACCase enzyme has been previously reported in other grass species. Our research confirms that the Ile-1781-Leu substitution is present in pinoxaden-resistant D. ciliaris.
A national need is to prepare for and respond to accidental or intentional disasters categorized as chemical, biological, radiological, nuclear, or explosive (CBRNE). These incidents require specific subject-matter expertise, yet have commonalities. We identify 7 core elements comprising CBRNE science that require integration for effective preparedness planning and public health and medical response and recovery. These core elements are (1) basic and clinical sciences, (2) modeling and systems management, (3) planning, (4) response and incident management, (5) recovery and resilience, (6) lessons learned, and (7) continuous improvement. A key feature is the ability of relevant subject matter experts to integrate information into response operations. We propose the CBRNE medical operations science support expert as a professional who (1) understands that CBRNE incidents require an integrated systems approach, (2) understands the key functions and contributions of CBRNE science practitioners, (3) helps direct strategic and tactical CBRNE planning and responses through first-hand experience, and (4) provides advice to senior decision-makers managing response activities. Recognition of both CBRNE science as a distinct competency and the establishment of the CBRNE medical operations science support expert informs the public of the enormous progress made, broadcasts opportunities for new talent, and enhances the sophistication and analytic expertise of senior managers planning for and responding to CBRNE incidents.
Epistemic justifications for democracy have been offered in terms of two different forms of information aggregation and decision-making. The Condorcet Jury Theorem is appealed to as a justification in terms of votes, and the Hong–Page ‘diversity trumps ability’ result is appealed to as a justification in terms of deliberation in the form of collaborative search. Both results, however, are models of full and direct participation across a population. In this paper, we contrast how these results hold up within the familiar structure of a representative hierarchy. We first consider extant analytic work that shows that representation inevitably weakens the voting results of the Condorcet Jury Theorem. We then go on to show that collaborative search, as modeled by Hong and Page, holds its own within hierarchical representation. In a variation on the dynamics of group search, representation even shows a slight edge over direct participation. This contrast illustrates how models of information aggregation vary when put into a representative structure. While some of the epistemic merits of democracy are lost when voting is done hierarchically, modeling results show that representation can preserve and even slightly amplify the epistemic virtues of collaborative search.
To compare rates of admission for different types of severe mental illness between ethnic groups, and to test the hypothesis that larger and more clustered ethnic groups will have lower admission rates. This was a descriptive study of routinely collected data from the National Health Service in England.
There was an eightfold difference in admission rates between ethnic groups for schizophreniform and mania admissions, and a fivefold variation in depression admissions. On average, Black and minority ethnic (BME) groups had higher rates of admission for schizophreniform and mania admissions but not for depression. This increased rate was greatest in the teenage years and early adulthood. Larger ethnic group size was associated with lower admission rates. However, greater clustering was associated with higher admission rates.
Our findings support the hypothesis that larger ethnic groups have lower rates of admission. This was a between-group comparison rather than within each group. Our findings do not support the hypothesis that more clustered groups have lower rates of admission. In fact, they suggest the opposite: groups with low clustering had lower admission rates. The BME population in the UK is increasing in size and becoming less clustered. Our results suggest that both of these factors should ameliorate the overrepresentation of BME groups among psychiatric in-patients. However, this overrepresentation continues, and our results suggest a possible explanation, namely, changes in the delivery of mental health services, particularly the marked reduction in admissions for depression.
The widespread occurrence of Palmer amaranth resistant to acetolactate synthase inhibitors and/or glyphosate led to the increased use of protoporphyrinogen oxidase (PPO)-inhibiting herbicides. This research aimed to: (1) evaluate the efficacy of foliar-applied fomesafen to Palmer amaranth, (2) evaluate cross-resistance to foliar PPO inhibitors and efficacy of foliar herbicides with different mechanisms of action, (3) survey the occurrence of the PPO Gly-210 deletion mutation among PPO inhibitor–resistant Palmer amaranth, (4) identify other PPO target-site mutations in resistant individuals, and (5) determine the resistance level in resistant accessions with or without the PPO Gly-210 deletion. Seedlings were sprayed with fomesafen (263 gaiha−1), dicamba (280 gaiha−1), glyphosate (870 gaiha−1), glufosinate (549 g ai ha−1), and trifloxysulfuron (7.84 gaiha−1). Selected fomesafen-resistant accessions were sprayed with other foliar-applied PPO herbicides. Mortality and injury were evaluated 21 d after treatment (DAT). The PPX2L gene of resistant and susceptible plants from a selected accession was sequenced. The majority (70%) of samples from putative PPO-resistant populations in 2015 were confirmed resistant to foliar-applied fomesafen. The efficacy of other foliar PPO herbicides on fomesafen-resistant accessions was saflufenacil>acifluorfen=flumioxazin>carfentrazone=lactofen>pyraflufen-ethyl>fomesafen>fluthiacet-methyl. With small seedlings, cross-resistance occurred with all foliar-applied PPO herbicides except saflufenacil (i.e., 25% with acifluorfen, 42% with flumioxazin). Thirty-two percent of PPO-resistant accessions were multiple resistant to glyphosate and trifloxysulfuron. Resistance to PPO herbicides in Palmer amaranth occurred in at least 13 counties in Arkansas. Of 316 fomesafen survivors tested, 55% carried the PPO Gly-210 deletion reported previously in common waterhemp. The PPO gene (PPX2L) in one accession (15CRI-B), which did not encode the Gly-210 deletion, encoded an Arg-128-Gly substitution. The 50% growth reduction values for fomesafen in accessions with Gly-210 deletion were 8- to 15-fold higher than that of a susceptible population, and 3- to 10-fold higher in accessions without the Gly-210 deletion.
Recent 13C solid state nuclear magnetic resonance studies have demonstrated differences in the composition of sporopollenins (the inert biomolecule forming spore and pollen walls) from the major groups of extant plants. This substance is also the main constituent of fossil spore walls.
We have obtained 13C NMR spectra from three species of Carboniferous lycopod megaspores, and in one case, the associated microspores. Additionally, spores from the Devonian plant Parka decipiens Fleming have been analyzed. The spectra obtained are relatively similar although at present it is unclear how much of this similarity results from diagenesis.
The spectra of the fossil spores have been compared to those obtained from extant lycopods and from other plant groups. The fossil lycopod spores share some of the distinctive features of modern lycopod sporopollenin but are, none the less, very different. The spectra of the fossil species also demonstrate the loss of constituents known to form a significant part of the sporopollenin in extant species. Our studies show that some of the chemical characteristics of sporopollenins are retained in fossil spores, allowing the investigation of evolutionary changes of sporopollenin within a group and facilitating the assignment of taxonomically enigmatic fossil species. Further investigation of a range of fossil material, combined with data obtained from pyrolysis, should provide further information on the composition of sporopollenin from different plant groups and on its diagenesis.
This book is a cultural history of the nineteenth-century songster: pocket-sized anthologies of song texts, usually without musical notation. It examines the musical, social, commercial and aesthetic functions songsters served and the processes by which they were produced and disseminated, the repertory they included, and the singers, printers and entrepreneurs that both inspired their manufacture and facilitated their consumption. Taking an international perspective, chapters focus on songsters from Ireland, North America, Australia and Britain and the varied public and private contexts in which they were used and exploited in oral and print cultures.