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Bringing Barley Back: Analysis of Heritage Varieties for Use as Germplasm Sources to Improve Resistance against the Most Devastating, Contemporary Disease in Canada, Fusarium Head Blight ( Fusarium graminearum). PLANTS (BASEL, SWITZERLAND) 2024; 13:799. [PMID: 38592826 PMCID: PMC10974673 DOI: 10.3390/plants13060799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 04/11/2024]
Abstract
Fusarium head blight (FHB), caused by Fusarium graminearum, is currently the most devastating disease for barley (Hordeum vulgare) in Canada. Associated mycotoxins can compromise grain quality, where deoxynivalenol (DON) is considered particularly damaging due to its frequency of detection. Breeding barley with a lower DON content is difficult, due to the poor adaptation and malt quality of resistance sources. A set of European-derived heritage varieties were screened in an FHB nursery in Charlottetown, PE, with selections tested at Brandon, MB, between 2018-2022. Genetic evaluation demonstrated a distinct clustering of Canadian varieties from the heritage set. At Brandon, 72% of the heritage varieties ranked lower for DON content than did the moderately resistant Canadian check 'AAC Goldman', but resistance was associated with later heading and taller stature. In contrast with Canadian modern malting variety 'AAC Synergy', general deficiencies were observed in yield, enzyme activity, and extract, along with higher protein content. Nonetheless, several resistant varieties were identified with reasonable a heading date and yield, including 'Chevallier Chile', 'Domen', 'Djugay', 'Hannchen', 'Heils Franken', 'Moravian Barley', 'Loosdorfer' with 'Golden Melon', 'Nutans Moskva', and 'Vellavia', these being some of the most promising varieties when malting quality characteristics were also considered. These heritage resources could be used as parents in breeding to develop FHB-resistant malting barley varieties.
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Endogenic Phenolic Compounds of Barley as Potential Biomarkers Related to Grain Mycotoxin Production and Cultivar Selection. BIOLOGY 2023; 12:1306. [PMID: 37887016 PMCID: PMC10604134 DOI: 10.3390/biology12101306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/25/2023] [Accepted: 10/01/2023] [Indexed: 10/28/2023]
Abstract
Barley (Hordeum vulgare L.) is the fourth largest cereal crop in the world. One of the most devastating diseases in barley worldwide is Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe. Several mycotoxins are produced by FHB infection, and deoxynivalenol (DON) is one of them responsible for the deterioration of grain quality. The current limited number of reliable molecular markers makes the development of FHB-resistant cultivars rather difficult and laborious. Moreover, there is a limited number of designed specific biomarkers that could distinguish the FHB resistance and mycotoxin accumulation in barley cultivars. This study investigated the phenolic compounds of ten different Canadian barley cultivars, grown in artificially FHB-infected and non-infected field trials. The enzyme-linked immunosorbent assay (ELISA) was used to assess the presence of DON in the harvested infected grains of each tested variety. High-performance liquid chromatography (HPLC) analysis was performed using both infected and non-infected samples. We identified differences among cultivars tested in non-infected samples through quantitative analysis of free and bound phenolic compounds. The resistant cultivars showed higher amounts of major bound phenolic compounds compared to the susceptible check CDC Bold. Additionally, the FHB-infected cultivars produced significantly higher amounts of sinapic acid (SIN) () and catechin (CAT) in the soluble free form of phenolics in barley compared to the non-infected subjects. This study suggests that phenolic compounds in barley could allow barley breeders to precisely identify and develop FHB-resistant barley germplasm and cultivars.
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A Biodegradable, Polymer-Supported Oxygen Atom Transfer Reagent. Polymers (Basel) 2023; 15:polym15092052. [PMID: 37177199 PMCID: PMC10181130 DOI: 10.3390/polym15092052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Biodegradable polymers are desirable to mitigate the environmental impact of plastic waste in the environment. Over the past several decades, the development of organocatalytic ring-opening polymerization (OROP) has made the synthesis of many new types of biodegradable polymers possible. In this research article, the first example of an oxygen atom transfer reagent pendant on a biodegradable polymer backbone is reported. The monomers for the polycarbonate backbone are sourced from the biodegradable 2,2-bis(hydroxymethyl) propionic acid molecule, and an iodoaryl group is installed pendant to the cyclic monomer for post-polymerization modification into an iodosylaryl oxygen atom transfer reagent. The key I-O bond is characterized by XPS spectroscopy, and a test reaction to triphenylphosphine demonstrates the ability of the polymer to engage in an oxygen atom transfer reaction with a substrate.
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A Shared Latent Process Model to Correct for Preferential Sampling in Disease Surveillance Systems. JOURNAL OF AGRICULTURAL, BIOLOGICAL AND ENVIRONMENTAL STATISTICS 2023. [DOI: 10.1007/s13253-023-00535-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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NEW ASSOCIATION BETWEEN THE VOLE MICROTUS CALIFORNICUS (RODENTIA: CRICETIDAE) AND THE FLEA STENISTOMERA ALPINA (SIPHONAPTERA: HYSTRICHOPSYLLIDAE). SOUTHWEST NAT 2022. [DOI: 10.1894/0038-4909-66.2.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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GPTransformer: A Transformer-Based Deep Learning Method for Predicting Fusarium Related Traits in Barley. FRONTIERS IN PLANT SCIENCE 2021; 12:761402. [PMID: 34975945 PMCID: PMC8716695 DOI: 10.3389/fpls.2021.761402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/23/2021] [Indexed: 05/27/2023]
Abstract
Fusarium head blight (FHB) incited by Fusarium graminearum Schwabe is a devastating disease of barley and other cereal crops worldwide. Fusarium head blight is associated with trichothecene mycotoxins such as deoxynivalenol (DON), which contaminates grains, making them unfit for malting or animal feed industries. While genetically resistant cultivars offer the best economic and environmentally responsible means to mitigate disease, parent lines with adequate resistance are limited in barley. Resistance breeding based upon quantitative genetic gains has been slow to date, due to intensive labor requirements of disease nurseries. The production of a high-throughput genome-wide molecular marker assembly for barley permits use in development of genomic prediction models for traits of economic importance to this crop. A diverse panel consisting of 400 two-row spring barley lines was assembled to focus on Canadian barley breeding programs. The panel was evaluated for FHB and DON content in three environments and over 2 years. Moreover, it was genotyped using an Illumina Infinium High-Throughput Screening (HTS) iSelect custom beadchip array of single nucleotide polymorphic molecular markers (50 K SNP), where over 23 K molecular markers were polymorphic. Genomic prediction has been demonstrated to successfully reduce FHB and DON content in cereals using various statistical models. Herein, we have studied an alternative method based on machine learning and compare it with a statistical approach. The bi-allelic SNPs represented pairs of alleles and were encoded in two ways: as categorical (-1, 0, 1) or using Hardy-Weinberg probability frequencies. This was followed by selecting essential genomic markers for phenotype prediction. Subsequently, a Transformer-based deep learning algorithm was applied to predict FHB and DON. Apart from the Transformer method, a Residual Fully Connected Neural Network (RFCNN) was also applied. Pearson correlation coefficients were calculated to compare true vs. predicted outputs. Models which included all markers generally showed marginal improvement in prediction. Hardy-Weinberg encoding generally improved correlation for FHB (6.9%) and DON (9.6%) for the Transformer network. This study suggests the potential of the Transformer based method as an alternative to the popular BLUP model for genomic prediction of complex traits such as FHB or DON, having performed equally or better than existing machine learning and statistical methods.
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Genome-Wide Association Study of Waterlogging Tolerance in Barley ( Hordeum vulgare L.) Under Controlled Field Conditions. FRONTIERS IN PLANT SCIENCE 2021; 12:711654. [PMID: 34512694 PMCID: PMC8427447 DOI: 10.3389/fpls.2021.711654] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/21/2021] [Indexed: 06/01/2023]
Abstract
Waterlogging is one of the main abiotic stresses severely reducing barley grain yield. Barley breeding programs focusing on waterlogging tolerance require an understanding of genetic loci and alleles in the current germplasm. In this study, 247 worldwide spring barley genotypes grown under controlled field conditions were genotyped with 35,926 SNPs with minor allele frequency (MAF) > 0.05. Significant phenotypic variation in each trait, including biomass, spikes per plant, grains per plant, kernel weight per plant, plant height and chlorophyll content, was observed. A genome-wide association study (GWAS) based on linkage disequilibrium (LD) for waterlogging tolerance was conducted. Population structure analysis divided the population into three subgroups. A mixed linkage model using both population structure and kinship matrix (Q+K) was performed. We identified 17 genomic regions containing 51 significant waterlogging-tolerance-associated markers for waterlogging tolerance response, accounting for 5.8-11.5% of the phenotypic variation, with a majority of them localized on chromosomes 1H, 2H, 4H, and 5H. Six novel QTL were identified and eight potential candidate genes mediating responses to abiotic stresses were located at QTL associated with waterlogging tolerance. To our awareness, this is the first GWAS for waterlogging tolerance in a worldwide barley collection under controlled field conditions. The marker-trait associations could be used in the marker-assisted selection of waterlogging tolerance and will facilitate barley breeding.
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Transcriptome Alterations of an in vitro-Selected, Moderately Resistant, Two-Row Malting Barley in Response to 3ADON, 15ADON, and NIV Chemotypes of Fusarium graminearum. FRONTIERS IN PLANT SCIENCE 2021; 12:701969. [PMID: 34456945 PMCID: PMC8385242 DOI: 10.3389/fpls.2021.701969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/05/2021] [Indexed: 06/01/2023]
Abstract
Fusarium head blight caused by Fusarium graminearum is a devastating disease of malting barley. Mycotoxins associated with contaminated grain can be transferred from malt to beer and pose a health risk to consumers. In western Canada, F. graminearum has undergone an adaptive shift from 15ADON constituency to dominance by virulent 3ADON-producers; likewise, NIV-producers have established in regions of southern United States. Lack of adapted resistance sources with adequate malting quality has promoted the use of alternative breeding methodologies, such as in vitro selection. We studied the low-deoxynivalenol characteristic of in vitro selected, two-row malting barley variety "Norman" by RNAseq in contrast to its parental line "CDC Kendall," when infected by 15ADON-, 3ADON-, and NIV-producing isolates of F. graminearum. The current study documents higher mycotoxin accumulation by 3ADON isolates, thereby representing increased threat to barley production. At 72-96-h post infection, significant alterations in transcription patterns were observed in both varieties with pronounced upregulation of the phenylpropanoid pathway and detoxification gene categories (UGT, GST, CyP450, and ABC), particularly in 3ADON treatment. Defense response was multitiered, where differential expression in "Norman" associated with antimicrobial peptides (thionin 2.1, defensing, non-specific lipid-transfer protein) and stress-related proteins, such as late embryogenesis abundant proteins, heat-shock, desiccation related, and a peroxidase (HvPrx5). Several gene targets identified in "Norman" would be useful for application of breeding varieties with reduced deoxynivalenol content.
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Genome Assembly of the Canadian two-row Malting Barley cultivar AAC Synergy. G3-GENES GENOMES GENETICS 2021; 11:6128399. [PMID: 33856017 PMCID: PMC8049406 DOI: 10.1093/g3journal/jkab031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 12/20/2022]
Abstract
Barley (Hordeum vulgare L.) is one of the most important global crops. The six-row barley cultivar Morex reference genome has been used by the barley research community worldwide. However, this reference genome can have limitations when used for genomic and genetic diversity analysis studies, gene discovery, and marker development when working in two-row germplasm that is more common to Canadian barley. Here we assembled, for the first time, the genome sequence of a Canadian two-row malting barley, cultivar AAC Synergy. We applied deep Illumina paired-end reads, long mate-pair reads, PacBio sequences, 10X chromium linked read libraries, and chromosome conformation capture sequencing (Hi-C) to generate a contiguous assembly. The genome assembled from super-scaffolds had a size of 4.85 Gb, N50 of 2.32 Mb, and an estimated 93.9% of complete genes from a plant database (BUSCO, benchmarking universal single-copy orthologous genes). After removal of small scaffolds (< 300 Kb), the assembly was arranged into pseudomolecules of 4.14 Gb in size with seven chromosomes plus unanchored scaffolds. The completeness and annotation of the assembly were assessed by comparing it with the updated version of six-row Morex and recently released two-row Golden Promise genome assemblies.
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Sensory profiles in adults with and without ADHD. RESEARCH IN DEVELOPMENTAL DISABILITIES 2020; 104:103696. [PMID: 32526674 PMCID: PMC7786815 DOI: 10.1016/j.ridd.2020.103696] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/14/2020] [Accepted: 05/13/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Our previous work demonstrates that adults with ADHD produce more force at the fingertips compared to adults without ADHD. One possibility is that somatosensation is impaired in ADHD. However, ADHD is often comorbid with anxiety, and anxiety influences sensory responsivity. AIMS The goal of the current work was to evaluate differences in the self-report of sensory experiences in adults with and without ADHD, while controlling for internalizing behaviors. METHODS AND PROCEDURES Forty-five adults (23 with ADHD) completed a semi-structured interview for the diagnosis of ADHD, the Adolescent/Adult Sensory Profile (AASP), and the Achenbach Adult Self Report (ASR). OUTCOMES AND RESULTS Adults with ADHD reported more hyper- and hypo- sensitivity compared to adults without ADHD, even when controlling for internalizing behaviors. Specifically, between group differences were found for low registration, sensation seeking, and sensory sensitivity scores, but not for sensation avoiding, and for movement, visual, touch, activity, audition, or taste/smell. CONCLUSIONS AND IMPLICATIONS These findings demonstrate that sensory hyper- and hypo- sensitivity may be features of ADHD in adults. Further, they demonstrate that internalizing behaviors influence the perception of sensory experiences and thus should be accounted for in studies of sensory processing, integration, and modulation in adults with ADHD.
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Genome-Wide Analysis of Gene Expression Provides New Insights into Waterlogging Responses in Barley ( Hordeum vulgare L.). PLANTS 2020; 9:plants9020240. [PMID: 32069892 PMCID: PMC7076447 DOI: 10.3390/plants9020240] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 12/13/2022]
Abstract
Waterlogging is a major abiotic stress causing oxygen depletion and carbon dioxide accumulation in the rhizosphere. Barley is more susceptible to waterlogging stress than other cereals. To gain a better understanding, the genome-wide gene expression responses in roots of waterlogged barley seedlings of Yerong and Deder2 were analyzed by RNA-Sequencing. A total of 6736, 5482, and 4538 differentially expressed genes (DEGs) were identified in waterlogged roots of Yerong at 72 h and Deder2 at 72 and 120 h, respectively, compared with the non-waterlogged control. Gene Ontology (GO) enrichment analyses showed that the most significant changes in GO terms, resulted from these DEGs observed under waterlogging stress, were related to primary and secondary metabolism, regulation, and oxygen carrier activity. In addition, more than 297 transcription factors, including members of MYB, AP2/EREBP, NAC, WRKY, bHLH, bZIP, and G2-like families, were identified as waterlogging responsive. Tentative important contributors to waterlogging tolerance in Deder2 might be the highest up-regulated DEGs: Trichome birefringence, α/β-Hydrolases, Xylanase inhibitor, MATE efflux, serine carboxypeptidase, and SAUR-like auxin-responsive protein. The study provides insights into the molecular mechanisms underlying the response to waterlogging in barley, which will be of benefit for future studies of molecular responses to waterlogging and will greatly assist barley genetic research and breeding.
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Deoxynivalenol-3-Glucoside Content Is Highly Associated with Deoxynivalenol Levels in Two-Row Barley Genotypes of Importance to Canadian Barley Breeding Programs. Toxins (Basel) 2019; 11:E319. [PMID: 31195591 PMCID: PMC6628427 DOI: 10.3390/toxins11060319] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/15/2019] [Accepted: 05/24/2019] [Indexed: 01/15/2023] Open
Abstract
Barley (Hordeum vulgare L.) is a multipurpose crop that can be harvested as grain or cut prior to maturity for use as forage. Fusarium head blight (FHB) is a devastating disease of barley that reduces quality of grain. FHB can also result in the accumulation of mycotoxins such as deoxynivalenol (DON). Breeding FHB resistant varieties has been a long-term goal of many barley-producing countries, including Canada. While the genetic basis of DON detoxification via production of less-phytotoxic conjugates such as DON-3-glucoside (DON3G) is well documented in barley, little information exists in reference to varietal response. Over two years, 16 spring, two-row barley genotypes, of importance to western Canadian barley breeding programs, were grown as short-rows and inoculated following spike emergence with a Fusarium graminearum conidia suspension. Half of the plots were harvested at soft dough stage and then dissected into rachis and grain components, whereas the remainder was harvested at maturity. Multiple Fusarium-mycotoxins were assayed using liquid chromatography-mass spectrometry. Mycotoxin content was elevated at the earlier harvest point, especially in the rachis tissue. DON3G constituted a significant percentage (26%) of total trichothecene content and thus its co-occurrence with DON should be considered by barley industries. DON3G was highly correlated with DON and 3-acetyl-deoxynivalenol (3ADON). The ratio of D3G/DON exhibited consistency across genotypes, however more-resistant genotypes were characterized by a higher ratio at the soft-dough stage followed by a decrease at maturity. Plant breeding practices that use DON content as a biomarker for resistance would likely result in the development of barley cultivars with lower total DON-like compounds.
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Avian hosts of Ixodes pacificus (Acari: Ixodidae) and the detection of Borrelia burgdorferi in larvae feeding on the Oregon junco. JOURNAL OF MEDICAL ENTOMOLOGY 2011; 48:852-859. [PMID: 21845945 DOI: 10.1603/me11001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Larval and nymphal western blacklegged tick, Ixodes pacificus Cooley & Kohls (Acari: Ixodidae), were collected from birds, rodents, and lizards at Quail Ridge Reserve located in Napa County in northwestern California. Species from three vertebrate classes were sampled simultaneously from two transects during two consecutive spring seasons. Feeding larval and nymphal ticks were removed and preserved for counting, examination and testing for the presence of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. Mean infestations with I. pacificus subadults on lizards were 10.0, on birds 2.9, and on rodents 1.3. I. pacificus larvae (204) collected from 10 avian species and (215) collected from two rodent species were tested for the presence of B. burgdorferi s.s. via real-time polymerase chain reaction. Three B. burgdorferi-infected larvae were taken from two Junco hyemalis and two infected larvae from one Neotoma fuscipes Baird. This is the detection of B. burgdorferi ss in an Ixodes pacificus larvae feeding on a Junco hyemalis L., [corrected] in western North America.
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Plague studies in California: a review of long-term disease activity, flea-host relationships and plague ecology in the coniferous forests of the Southern Cascades and northern Sierra Nevada mountains. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2010; 35:1-12. [PMID: 20618641 DOI: 10.1111/j.1948-7134.2010.00021.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We review 28 years of long-term surveillance (1970-1997) for plague activity among wild rodents from ten locations within three coniferous forest habitat types in the northern Sierra Nevada and the Southern Cascade mountains of northeastern California. We identify rodent hosts and their fleas and document long-term plague activity in each habitat type. The highest seroprevalence for Yersinia pestis occurred in the chipmunks, Tamias senex and T. quadrimaculatus, and the pine squirrel, Tamiasciurus douglasii. The most commonly infected fleas were Ceratophyllus ciliatus and Eumolpianus eumolpi from chipmunks and Oropsylla montana and O. idahoensis from ground squirrels. Serological surveillance demonstrated that populations of T. senex, T. quadrimaculatus and T. douglasii are moderately resistant to plague, survive infection, and are, therefore, good sentinels for plague activity. Recaptured T. senex and T. quadrimaculatus showed persistence of plague antibodies and evidence of re-infection over a two year period. These rodent species, their fleas, and the ecological factors common to the coniferous forest habitats likely promote the maintenance of plague foci in northeastern California.
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Genetic relatedness and virulence gene profiles of Escherichia coli strains isolated from septicaemic and uroseptic patients. Eur J Clin Microbiol Infect Dis 2009; 29:15-23. [PMID: 19763642 DOI: 10.1007/s10096-009-0809-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 08/08/2009] [Indexed: 10/20/2022]
Abstract
We investigated the relationship between clonality and virulence factors (VFs) of a collection of Escherichia coli strains isolated from septicaemic and uroseptic patients with respect to their origin of translocation. Forty septicaemic and 30 uroseptic strains of E. coli were tested for their phylogenetic groupings, genetic relatedness using randomly amplified polymorphic DNA (RAPD), biochemical fingerprinting method (biochemical phenotypes [BPTs]), adherence to HT-29 cells and the presence of 56 E. coli VF genes. Strains belonging to phylogenetic groups B2 and D constituted 93% of all strains. Fifty-four (77%) strains belonged to two major BPT/RAPD clusters (A and B), with cluster A carrying significantly (P = 0.0099) more uroseptic strains. The degree of adhesion to HT-29 cells of uroseptic strains was significantly (P = 0.0012) greater than that of septicaemic strains. Of the 56 VF genes tested, pap genes was the only group that were found significantly (P < 0.0001) more often among uroseptic isolates. Phylogenetic group B2 contained a significantly higher number of strains carrying pap genes than those in group D. We conclude that uroseptic E. coli are clonally different from septicaemic strains, carry more pap genes and predominantly adhere more to the HT-29 cell model of the gut.
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Spatial analysis of plague in California: niche modeling predictions of the current distribution and potential response to climate change. Int J Health Geogr 2009; 8:38. [PMID: 19558717 PMCID: PMC2716330 DOI: 10.1186/1476-072x-8-38] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Accepted: 06/28/2009] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Plague, caused by the bacterium Yersinia pestis, is a public and wildlife health concern in California and the western United States. This study explores the spatial characteristics of positive plague samples in California and tests Maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. Maxent models were constructed using geocoded seroprevalence data from surveillance of California ground squirrels (Spermophilus beecheyi) as case points and Worldclim bioclimatic data as predictor variables, and compared and validated using area under the receiver operating curve (AUC) statistics. Additionally, model results were compared to locations of positive and negative coyote (Canis latrans) samples, in order to determine the correlation between Maxent model predictions and areas of plague risk as determined via wild carnivore surveillance. RESULTS Models of plague activity in California ground squirrels, based on recent climate conditions, accurately identified case locations (AUC of 0.913 to 0.948) and were significantly correlated with coyote samples. The final models were used to identify potential plague risk areas based on an ensemble of six future climate scenarios. These models suggest that by 2050, climate conditions may reduce plague risk in the southern parts of California and increase risk along the northern coast and Sierras. CONCLUSION Because different modeling approaches can yield substantially different results, care should be taken when interpreting future model predictions. Nonetheless, niche modeling can be a useful tool for exploring and mapping the potential response of plague activity to climate change. The final models in this study were used to identify potential plague risk areas based on an ensemble of six future climate scenarios, which can help public managers decide where to allocate surveillance resources. In addition, Maxent model results were significantly correlated with coyote samples, indicating that carnivore surveillance programs will continue to be important for tracking the response of plague to future climate conditions.
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An avian contribution to the presence of Ixodes pacificus (Acari: Ixodidae) and Borrelia burgdorferi on the Sutter Buttes of California. JOURNAL OF MEDICAL ENTOMOLOGY 2006; 43:368-74. [PMID: 16619623 DOI: 10.1603/0022-2585(2006)043[0368:aacttp]2.0.co;2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Birds from 45 species were sampled during three spring seasons from an isolated canyon on the Sutter Buttes in California for the presence of subadult stages of Ixodes pacificus Cooley & Kohls, and for infection with Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. These birds were found to have an infestation prevalence of 45%, a density of 1.7 ticks per bird, and an intensity of 3.8 ticks per infested bird. There was a significant difference in the I. pacificus infestations between canopy and ground-dwelling birds. Birds also demonstrated an overall infection with B. burgdorferi of 6.4% with significant difference between bird species. Amplification and subsequent sequencing of the 23s-5s rRNA intergenic spacer region of the Borrelia genome from one bird, a hermit thrush, Catharus guttatus (Nuttall), showed that the infection in this bird was caused by B. burgdorferi sensu stricto; the first such finding in a bird from the far west. Our results suggest that birds play a role in the distribution and maintenance of I. pacificus, and possibly of B. burgdoferi, at the Sutter Buttes, CA.
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Isolation and characterization of Borrelia hermsii associated with two foci of tick-borne relapsing fever in California. J Clin Microbiol 2004; 42:1123-8. [PMID: 15004063 PMCID: PMC356836 DOI: 10.1128/jcm.42.3.1123-1128.2004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Relapsing fever, caused by the spirochete Borrelia hermsii and transmitted by the soft tick Ornithodoros hermsi, is endemic in many rural mountainous areas of California. Between 1996 and 1998, 12 cases of relapsing fever associated with two exposure sites in northern California were investigated. Follow-up at exposure sites included collection of soft ticks and serum specimens from sylvatic rodents. Attempts to cultivate spirochetes were made through inoculation of patient blood into mice and by feeding Ornithodoros ticks on mice. Three isolates of B. hermsii were recovered from two blood specimens and one pool of ticks. The protein and plasmid profiles of the three isolates were comparable to those of previous B. hermsii isolates from the western United States. Western immunoblotting of patient sera demonstrated an expanding immunologic response to antigens within four distinct molecular weight regions by 3 to 4 weeks postonset. Antibody to B. hermsii was detected in sera from 4 of 11 yellow-pine chipmunks (Tamias amoenus); no other rodent species collected were seropositive.
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Spectroscopic characterization of an electrophilic transition-metal-methylene complex, .eta.5-C5H5[(C6H5)2PCH2CH2P(C6H5)2]Fe:CH2+. J Am Chem Soc 2002. [DOI: 10.1021/ja00523a068] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Facile synthesis, spectral characterization, and ethylidene transfer reactions of complexes of the type Cp(CO)(L)Fe:CHCH3+. J Am Chem Soc 2002. [DOI: 10.1021/ja00394a063] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Synthesis, spectral characterization and alkylidene-transfer reactions of electrophilic iron carbene complexes Cp(CO)(L)Fe:CHR+ (L = CO, PPh3; R = Me, Et, CHMe2). J Am Chem Soc 2002. [DOI: 10.1021/ja00340a020] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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24
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Abstract
We present the first documented case of overdose from xylazine inhalation. The patient developed findings consistent with alpha 2 adrenergic agonist toxicity, eg coma, miosis, apnea, bradycardia, hypothermia, and dry mouth 2 hours after exposure. Standard dose naloxone did not reverse these effects. The patient fully recovered after appropriate supportive measures. A review of prior reports of xylazine exposure is provided.
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25
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Indications for, techniques of, complications of, and efficacy of gastric lavage in the treatment of the poisoned child. Curr Opin Pediatr 2000; 12:163-5. [PMID: 10763767 DOI: 10.1097/00008480-200004000-00014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Gastrointestinal decontamination is central to the care of poisoned patients, and gastric lavage is one common method for gastrointestinal decontamination. Gastric lavage in pediatric patients should be limited to children who present shortly after a potentially life-threatening ingestion. The routine use of gastric lavage has recently been questioned because of limited outcome data and increased morbidity. If gastric lavage is deemed necessary, proper positioning of the patient and strict attention to appropriate technique are essential to avert complications.
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26
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Experimental and field evaluations of two acaracides for control of I. pacificus (Acari: Ixodidae) in northern California. JOURNAL OF MEDICAL ENTOMOLOGY 1999; 36:660-665. [PMID: 10593063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Use of acaricides for the control of Ixodes pacificus (Cooley & Kohls), the vector of Lyme borreliosis in the western United States, can be a beneficial component in a program to reduce the morbidity of Lyme borreliosis in California. Three commercially available acaricides, carbaryl, chlorpyrifos, and diazinon, were evaluated in laboratory bioassays for their effectiveness against I. pacificus adults. Based on bioassay results, chlorpyrifos and carbaryl were selected for field evaluations. Chlorpyrifos demonstrated the lowest LD50 in the laboratory and the best overall control in the field trials. Chlorpyrifos and carbaryl provided effective control with a residual effect on adult ticks up to 7 wk after a single treatment. A field application timed to coincide with the highest period of adult questing activity proved effective in the control of I. pacificus in a Sierran foothill habitat. Judicious use of either of the acaricides evaluated may help to reduce adult tick densities in a peridomestic environment and thereby reduce the risk of human exposure to Lyme borreliosis and other tick-borne agents.
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27
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Abstract
NAC is an effective antidote for APAP toxicity. NAC has been shown to be effective for early toxicity and is gaining acceptance for late toxicity. As the knowledge of APAP toxicity advances, the duration and route of NAC administration may be clarified.
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28
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Alcoholic beverages: proof and flammability. Am J Emerg Med 1998; 16:544-5. [PMID: 9725980 DOI: 10.1016/s0735-6757(98)90016-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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29
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Resource utilization. Pediatr Emerg Care 1998; 14:67-70. [PMID: 9516637 DOI: 10.1097/00006565-199802000-00018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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30
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Abstract
The scanning tunneling microscope has been used to desorb hydrogen from hydrogen-terminated silicon (100) surfaces. As a result of control of the dose of incident electrons, a countable number of desorption sites can be created and the yield and cross section are thereby obtained. Two distinct desorption mechanisms are observed: (i) direct electronic excitation of the Si-H bond by field-emitted electrons and (ii) an atomic resolution mechanism that involves multiple-vibrational excitation by tunneling electrons at low applied voltages. This vibrational heating effect offers significant potential for controlling surface reactions involving adsorbed individual atoms and molecules.
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31
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STM study of surface reconstructions of Si(111):B. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:7453-7460. [PMID: 9974725 DOI: 10.1103/physrevb.50.7453] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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32
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Abstract
Many of the causes of complaints can be reduced but not completely eliminated. Appropriate attention through education and quality management keeps the department's attention focused on increasing patient satisfaction.
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33
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Structure of GaAs(100)-c(8 x 2) determined by scanning tunneling microscopy. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:9138-9141. [PMID: 10007140 DOI: 10.1103/physrevb.48.9138] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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34
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Abstract
Chickenpox is a common contagious disease of childhood. Infection with varicella-zoster virus generally follows a benign course, but complications may occur. We report the case of a child with chickenpox who developed diffuse cerebritis with significant dehydration, azotemia, elevations in transaminases, and coagulopathy. The neurologic complications of varicella-zoster infection are reviewed.
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35
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Comment on "Size effects and charge-density-wave pinning in Nb1-xTixSe3: Evidence for weak pinning by a nonisoelectronic impurity". PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:7614-7617. [PMID: 10004765 DOI: 10.1103/physrevb.47.7614] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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36
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Comment on "Size effects and charge-density-wave pinning in NbSe3". PHYSICAL REVIEW LETTERS 1990; 65:270. [PMID: 10042598 DOI: 10.1103/physrevlett.65.270] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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37
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Dynamics of charge-density waves in electron-irradiated K0.3MoO3. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:7402-7410. [PMID: 9993030 DOI: 10.1103/physrevb.41.7402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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38
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Scanning tunneling microscopy of the charge-density wave in orthorhombic TaS3. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:11965-11968. [PMID: 9991813 DOI: 10.1103/physrevb.40.11965] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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39
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Scanning tunneling microscopy of NbSe3 and orthorhombic TaS3. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:9529-9532. [PMID: 9991470 DOI: 10.1103/physrevb.40.9529] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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40
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Impurity pinning of sliding charge-density waves. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:5447-5459. [PMID: 9992576 DOI: 10.1103/physrevb.40.5447] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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41
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Dielectric relaxation in o-TaS3: Charge-density-wave screening and near-commensurability effects. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:1720-1724. [PMID: 9992031 DOI: 10.1103/physrevb.40.1720] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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42
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Low-temperature depinning of sliding charge-density waves. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:7854-7857. [PMID: 9945527 DOI: 10.1103/physrevb.38.7854] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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43
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Interpretation of the complete excitation spectrum for pinned charge-density waves. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:4303-4306. [PMID: 9946812 DOI: 10.1103/physrevb.38.4303] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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44
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Theory of charge-density-wave dynamics. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:1148-1171. [PMID: 9946372 DOI: 10.1103/physrevb.38.1148] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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45
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ac-dc interference, complete mode locking, and origin of coherent oscillations in sliding charge-density-wave systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:10055-10067. [PMID: 9944432 DOI: 10.1103/physrevb.37.10055] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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46
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Proposed NMR test of strong pinning and phase slip in sliding-charge-density-wave systems. PHYSICAL REVIEW LETTERS 1988; 60:1574-1577. [PMID: 10038075 DOI: 10.1103/physrevlett.60.1574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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47
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Charge-density-wave transport in quasi-one-dimensional conductors. II. ac-dc interference phenomena. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:6360-6372. [PMID: 9940869 DOI: 10.1103/physrevb.35.6360] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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48
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Charge-density-wave transport in quasi-one-dimensional conductors. I. Current oscillations. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:6348-6359. [PMID: 9940868 DOI: 10.1103/physrevb.35.6348] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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49
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Experiment versus the classical model of deformable charge-density waves: Interference phenomena and mode locking. PHYSICAL REVIEW LETTERS 1987; 58:828-831. [PMID: 10035047 DOI: 10.1103/physrevlett.58.828] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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50
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Origin of the dielectric relaxation frequency in sliding-charge-density-wave systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1986; 34:9038-9041. [PMID: 9939651 DOI: 10.1103/physrevb.34.9038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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