bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential selection pressures exerted by host resistance quantitative trait loci on a pathogen population: a case study in an apple × Venturia inaequalis pathosystem
Authors: Van Amandine Lê , Caffier Valérie , Lasserre‐Zuber Pauline , Chauveau Aurélie , Brunel Dominique , Le Cam Bruno , Durel Charles‐Eric 
Published: December 2012

Summary

Understanding how pathogens evolve according to pressures exerted by their plant hosts is essential for the derivation of strategies aimed at the durable management of resistant cultivars. The spectrum of action of the resistance factors in the partially resistant cultivars is thought to be an important determinant of resistance durability. However, it has not yet been demonstrated whether the pressures exerted by quantitative resistance are different according to their spectrum of action.

To investigate selection pressures exerted by apple genotypes harbouring various resistance quantitative trait loci (QTLs) on a mixed inoculum of the scab disease agent, Venturia inaequalis, we monitored V. inaequalis isolate proportions on diseased apple leaves of an F1 progeny using quantitative pyrosequencing technology and QTL mapping.

Broad‐spectrum resistances did not exert any differential selection pressures on the mixed inoculum, whereas narrow‐spectrum resistances decreased the frequencies of some isolates in the mixture relative to the susceptible host genotypes.

Our results suggest that the management of resistant cultivars should be different according to the spectrum of action of their resistance factors. The pyramiding of broad‐spectrum factors or the use of a mixture of apple genotypes that carry narrow‐spectrum resistance factors are two possible strategies for the minimization of resistance erosion.
Diagnosis of hidden bronchial obstruction using computer‐assessed tracheal forced expiratory noise time
Authors: Pochekutova Irina A. , Korenbaum Vladimir I. 
Published: December 2012

AbstractBackground and objectiveIncreased forced expiratory time was first recognized as a marker of obstruction half a century ago. However, the reported diagnostic capabilities of both auscultated forced expiratory time (FETas) and spirometric forced expiratory time are contradictory. Computer analysis of respiratory noises provides a precise estimation of acoustic forced expiratory noise time (FETa) being the object‐measured analogue of FETas. The aim of this study was to analyse FETa diagnostic capabilities in patients with asthma based on the hypothesis that FETa could reveal hidden bronchial obstruction.MethodsA group of asthma patients involved 149 males aged 16–25 years. In this group, 71 subjects had spirometry features of bronchial obstruction, meanwhile, the remaining 78 had normal spirometry. A control group involved 77 healthy subjects. Spirometry and forced expiratory tracheal noise recording were sequentially measured for each participant. FETa values were estimated by means of a developed computer procedure, including bandpass filtration (200–2000 Hz), waveform envelope calculation with accumulation period of 0.01 s, automated measurement of FETa at 0.5% level from the peak amplitude.ResultsSpecificity, sensitivity and area under Receiver Operating Characteristic curve of FETa and its ratios to squared chest circumference, height, weight were indistinguishable with baseline spirometry index FEV1/forced vital capacity. Meanwhile, acoustic features of obstruction were revealed in 41%–49% of subgroup of patients with asthma but normal spirometry.ConclusionsFETa of tracheal noise and its ratio to anthropometric parameters seem to be sensitive and specific tests of hidden bronchial obstruction in young male asthma patients.
Implications of trace element composition of syntaxial quartz cements for the geochemical conditions during quartz precipitation in sandstones
Authors: Götte Thomas , Ramseyer Karl , Pettke Thomas , Koch‐Müller Monika 
Published: December 2012

AbstractA petrographic investigation revealed polyphase quartz cementation in the Finefrau Sandstone (Upper Carboniferous, Western Germany) and the Solling Sandstone (Lower Triassic, Central Germany). Three different cements could be distinguished in each sandstone based on their cathodoluminescence and trace element composition. The first quartz generation is suggested to have been formed during eogenesis due to dissolution and replacement of feldspar. The mesogenetic paragenesis comprises two generations of quartz and illite, which are accompanied by albite in the Solling Sandstone. Sharp luminescence zoning in quartz overgrowths points to distinct episodes of cementation in both sandstones. Significant amounts of Al, Li and H and traces of Ge and B have been detected in the quartz overgrowths. The Al‐content of the quartz cements in the Finefrau Sandstones exceeds that in the quartz cements in the Solling Sandstone by a factor of five. It is suggested that this compositional variation reflects the conditions in the pore‐water, such as temperature and pH. The Al‐concentration is generally correlated to the Li‐content with the exception of the latest quartz generation in the Finefrau Sandstones which is also most enriched in trace elements. The ratio of Li/Al varies between 0·11 and 0·25 in the two sandstones. The Li/H‐ratio, which ranges from 0·12 to 0·3, is controlled by the activity ratio of Li and H in the pore fluid. Clay minerals are the most important source for Li and high salinities favour the mobilization of Li during diagenesis. Thus, a relatively low salinity and low pH are responsible for the low Li/H‐ratio in the Finefrau Sandstone, while high salinity and neutral to alkaline pH results in a high Li/H‐ratio for the Solling Sandstone. The Ge‐contents are generally near the average of detrital quartz and indicate that pressure dissolution is a major source for quartz cementation. Different chemical compositions of distinct quartz generations indicate changes in the physico‐chemical conditions and point to mobilization of silica from different sources (for example, pressure solution and clay mineral transformations).
Issue Voting and Immigration: Do Restrictionist Policies Cost Congressional Republicans Votes?
Authors: Hawley George 
Published: December 2012

ObjectiveI test the hypothesis that Latino voters were less likely to support Republican incumbents with strong anti‐immigration records in the 2006 congressional elections in comparison to Republicans with less restrictive records. I also test whether non‐Hispanic white voters were similarly sensitive to incumbent immigration records when determining vote choice.MethodTo examine these questions, I created hierarchical models in which incumbent immigration records, individual views on immigration, and an interaction between the two were used to predict vote choice in the 2006 midterm elections. Individual‐level data were provided by the 2006 Cooperative Congressional Election Study and incumbent immigration records were provided by NumbersUSA.ResultsThis analysis found little or no evidence suggesting that Latino voters are less likely to support Republican incumbents with anti‐immigration records. There was evidence suggesting that vote choice among non‐Hispanic whites was influenced by incumbent records on immigration, but the effect varied according to the respondent's own views on immigration.ConclusionThis study found no evidence that incumbent Republicans could increase their share of the Latino vote by embracing less restrictive immigration policies. In fact, doing so may cost them votes among non‐Hispanic whites.
The maize lipoxygenase, ZmLOX10, mediates green leaf volatile, jasmonate and herbivore‐induced plant volatile production for defense against insect attack
Authors: Christensen Shawn A. , Nemchenko Andriy , Borrego Eli , Murray Ian , Sobhy Islam S. , Bosak Liz , DeBlasio Stacy , Erb Matthias , Robert Christelle A.M. , Vaughn Kathy A. , Herrfurth Cornelia , Tumlinson Jim , Feussner Ivo , Jackson David , Turlings Ted C.J. , Engelberth Jurgen , Nansen Christian , Meeley Robert , Kolomiets Michael V. 
Published: December 2012

SummaryFatty acid derivatives are of central importance for plant immunity against insect herbivores; however, major regulatory genes and the signals that modulate these defense metabolites are vastly understudied, especially in important agro‐economic monocot species. Here we show that products and signals derived from a single Zea mays (maize) lipoxygenase (LOX), ZmLOX10, are critical for both direct and indirect defenses to herbivory. We provide genetic evidence that two 13‐LOXs, ZmLOX10 and ZmLOX8, specialize in providing substrate for the green leaf volatile (GLV) and jasmonate (JA) biosynthesis pathways, respectively. Supporting the specialization of these LOX isoforms, LOX8 and LOX10 are localized to two distinct cellular compartments, indicating that the JA and GLV biosynthesis pathways are physically separated in maize. Reduced expression of JA biosynthesis genes and diminished levels of JA in lox10 mutants indicate that LOX10‐derived signaling is required for LOX8‐mediated JA. The possible role of GLVs in JA signaling is supported by their ability to partially restore wound‐induced JA levels in lox10 mutants. The impaired ability of lox10 mutants to produce GLVs and JA led to dramatic reductions in herbivore‐induced plant volatiles (HIPVs) and attractiveness to parasitoid wasps. Because LOX10 is under circadian rhythm regulation, this study provides a mechanistic link to the diurnal regulation of GLVs and HIPVs. GLV‐, JA‐ and HIPV‐deficient lox10 mutants display compromised resistance to insect feeding, both under laboratory and field conditions, which is strong evidence that LOX10‐dependent metabolites confer immunity against insect attack. Hence, this comprehensive gene to agro‐ecosystem study reveals the broad implications of a single LOX isoform in herbivore defense.
Zhu Rongji Might Be Right: Understanding the Mechanism of Fast Economic Development in China
Authors: Zhang Jun 
Published: December 2012

AbstractUnderstanding the facilitating role of regional governments and the source of regional competition is the key to demystifying the success of China’s fast economic development since the 1990s. This paper, as the product of the lecture the author delivered at The World Economy China Annual Lecture on 3 November 2011 at University of Nottingham, provides a framework that better illustrates the mechanism that motivates China’s economic growth over the past 20 years. It shows that the current growth mechanism in China is largely the result of institutional reforms and fiscal recentralisation that occurred in 1994 under the leadership of Premier Zhu Rongji. Being allowed to have their own source of tax revenue under the new fiscal reform, Chinese regional governments are motivated to pursue the goal of economic growth through fast capital formation and industrialisation. The newly designed intergovernmental fiscal relationship, as the most important reform programme in China, has also helped create a growth incentive that is compatible between central and local governments, and resulted in a Tibout‐type regional competition in the sense that inefficient use of resources, including public land, would be substantially eliminated by the strategic behaviour of regional governments being more attractive to external direct investment. Such regional competition makes the regional governments preserve and use the markets rather than replace them, and has generated consistent and powerful development momentum for the post‐1994 economy of China.
Blue Light Rescues Mice from Potentially Fatal Pseudomonas aeruginosa Burn Infection: Efficacy, Safety, and Mechanism of Action
Authors: Dai Tianhong , Gupta Asheesh , Huang Ying-Ying , Yin Rui , Murray Clinton K. , Vrahas Mark S. , Sherwood Margaret E. , Tegos George P. , Hamblin Michael R. 
Published: December 2012

ABSTRACT

Blue light has attracted increasing attention due to its intrinsic antimicrobial effect without the addition of exogenous photosensitizers. However, the use of blue light for wound infections has not been established yet. In this study, we demonstrated the efficacy of blue light at 415 nm for the treatment of acute, potentially lethal
Pseudomonas aeruginosa
burn infections in mice. Our
in vitro
studies demonstrated that the inactivation rate of
P. aeruginosa
cells by blue light was approximately 35-fold higher than that of keratinocytes (
P
= 0.0014). Transmission electron microscopy revealed blue light-mediated intracellular damage to
P. aeruginosa
cells. Fluorescence spectroscopy suggested that coproporphyrin III and/or uroporphyrin III are possibly the intracellular photosensitive chromophores associated with the blue light inactivation of
P. aeruginosa
.
In vivo
studies using an
in vivo
bioluminescence imaging technique and an area-under-the-bioluminescence-time-curve (AUBC) analysis showed that a single exposure of blue light at 55.8 J/cm
2
, applied 30 min after bacterial inoculation to the infected mouse burns, reduced the AUBC by approximately 100-fold in comparison with untreated and infected mouse burns (
P
< 0.0001). Histological analyses and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays indicated no significant damage in the mouse skin exposed to blue light at the effective antimicrobial dose. Survival analyses revealed that blue light increased the survival rate of the infected mice from 18.2% to 100% (
P
< 0.0001). In conclusion, blue light therapy might offer an effective and safe alternative to conventional antimicrobial therapy for
P. aeruginosa
burn infections.
Growth Inhibition of Pathogenic Bacteria by Sulfonylurea Herbicides
Authors: Kreisberg Jason F. , Ong Nicholas T. , Krishna Aishwarya , Joseph Thomas L. , Wang Jing , Ong Catherine , Ooi Hui Ann , Sung Julie C. , Siew Chern Chiang , Chang Grace C. , Biot Fabrice , Cuccui Jon , Wren Brendan W. , Chan Joey , Sivalingam Suppiah P. , Zhang Lian-Hui , Verma Chandra , Tan Patrick 
Published: December 2012

ABSTRACT

Emerging resistance to current antibiotics raises the need for new microbial drug targets. We show that targeting branched-chain amino acid (BCAA) biosynthesis using sulfonylurea herbicides, which inhibit the BCAA biosynthetic enzyme acetohydroxyacid synthase (AHAS), can exert bacteriostatic effects on several pathogenic bacteria, including
Burkholderia pseudomallei
,
Pseudomonas aeruginosa
, and
Acinetobacter baumannii
. Our results suggest that targeting biosynthetic enzymes like AHAS, which are lacking in humans, could represent a promising antimicrobial drug strategy.
Detection of Borrelia burgdorferi Sensu Stricto
ospC
Alleles Associated with Human Lyme Borreliosis Worldwide in Non-Human-Biting Tick Ixodes affinis and Rodent Hosts in Southeastern United States
Authors: Rudenko Nataliia , Golovchenko Maryna , Hönig Václav , Mallátová Nadja , Krbková Lenka , Mikulášek Peter , Fedorova Natalia , Belfiore Natalia M. , Grubhoffer Libor , Lane Robert S. , Oliver James H. 
Published: December 2012

ABSTRACT

Comparative analysis of
ospC
genes from 127
Borrelia burgdorferi
sensu stricto strains collected in European and North American regions where Lyme disease is endemic and where it is not endemic revealed a close relatedness of geographically distinct populations.
ospC
alleles A, B, and L were detected on both continents in vectors and hosts, including humans. Six
ospC
alleles, A, B, L, Q, R, and V, were prevalent in Europe; 4 of them were detected in samples of human origin. Ten
ospC
alleles, A, B, D, E3, F, G, H, H3, I3, and M, were identified in the far-western United States. Four
ospC
alleles, B, G, H, and L, were abundant in the southeastern United States. Here we present the first expanded analysis of
ospC
alleles of
B. burgdorferi
strains from the southeastern United States with respect to their relatedness to strains from other North American and European localities. We demonstrate that
ospC
genotypes commonly associated with human Lyme disease in European and North American regions where the disease is endemic were detected in
B. burgdorferi
strains isolated from the non-human-biting tick
Ixodes affinis
and rodent hosts in the southeastern United States. We discovered that some
ospC
alleles previously known only from Europe are widely distributed in the southeastern United States, a finding that confirms the hypothesis of transoceanic migration of
Borrelia
species.
Anaplasma phagocytophilum in Questing Ixodes ricinus Ticks: Comparison of Prevalences and Partial 16S rRNA Gene Variants in Urban, Pasture, and Natural Habitats
Authors: Overzier Evelyn , Pfister Kurt , Thiel Claudia , Herb Ingrid , Mahling Monia , Silaghi Cornelia 
Published: December 2012

ABSTRACT

Urban, natural, and pasture areas were investigated for prevalences and 16S rRNA gene variants of
Anaplasma phagocytophilum
in questing
Ixodes ricinus
ticks. The prevalences differed significantly between habitat types, and year-to-year variations in prevalence and habitat-dependent occurrence of 16S rRNA gene variants were detected.
Depletion of Unwanted Nucleic Acid Templates by Selective Cleavage: LNAzymes, Catalytically Active Oligonucleotides Containing Locked Nucleic Acids, Open a New Window for Detecting Rare Microbial Community Members
Authors: Dolinšek Jan , Dorninger Christiane , Lagkouvardos Ilias , Wagner Michael , Daims Holger 
Published: December 2012

ABSTRACTMany studies of molecular microbial ecology rely on the characterization of microbial communities by PCR amplification, cloning, sequencing, and phylogenetic analysis of genes encoding rRNAs or functional marker enzymes. However, if the established clone libraries are dominated by one or a few sequence types, the cloned diversity is difficult to analyze by random clone sequencing. Here we present a novel approach to deplete unwanted sequence types from complex nucleic acid mixtures prior to cloning and downstream analyses. It employs catalytically active oligonucleotides containing locked nucleic acids (LNAzymes) for the specific cleavage of selected RNA targets. When combined within vitrotranscription and reverse transcriptase PCR, this LNAzyme-based technique can be used with DNA or RNA extracts from microbial communities. The simultaneous application of more than one specific LNAzyme allows the concurrent depletion of different sequence types from the same nucleic acid preparation. This new method was evaluated with defined mixtures of cloned 16S rRNA genes and then used to identify accompanying bacteria in an enrichment culture dominated by the nitrite oxidizer “CandidatusNitrospira defluvii.”In silicoanalysis revealed that the majority of publicly deposited rRNA-targeted oligonucleotide probes may be used as specific LNAzymes with no or only minor sequence modifications. This efficient and cost-effective approach will greatly facilitate tasks such as the identification of microbial symbionts in nucleic acid preparations dominated by plastid or mitochondrial rRNA genes from eukaryotic hosts, the detection of contaminants in microbial cultures, and the analysis of rare organisms in microbial communities of highly uneven composition.
Patterns of Nucleotide Diversity of the
ldpA
Circadian Gene in Closely Related Species of Cyanobacteria from Extreme Cold Deserts
Authors: Ng Ka Wai , Pointing Stephen B. , Dvornyk Volodymyr 
Published: December 2012

ABSTRACT

In the circadian system of cyanobacteria, the
ldpA
gene is a component of the input to the clock. We comparatively analyzed nucleotide polymorphism of this gene in populations of two closely related species of cyanobacteria (denoted as
Synechococcus
species S1 and S2, respectively) from extreme cold deserts in Antarctica, the Canadian Arctic, and Tibet. Although both species manifested similarly high haplotype diversities (0.990 and 0.809, respectively), the nucleotide diversity differed significantly (0.0091 in S1 and 0.0037 in S2). The populations of species S2 were more differentiated (

F
ST

= 0.2242) compared to those of species S1 (

F
ST

between 0.0296 and 0.1188). An analysis of positive selection with several tests yielded highly significant values (
P
< 0.01) for both species. On the other hand, these results may be somewhat compromised by fluctuating population sizes of the species. The apparent selection pressure coupled with the pronounced demographic factors, such as population expansion, small effective population size, and genetic drift, may thus result in the observed significant interpopulation differentiation and subsequent speciation of cyanobacteria.
Members of the Penicillium chrysogenum Velvet Complex Play Functionally Opposing Roles in the Regulation of Penicillin Biosynthesis and Conidiation
Authors: Kopke Katarina , Hoff Birgit , Bloemendal Sandra , Katschorowski Alexandra , Kamerewerd Jens , Kück Ulrich 
Published: December 2012

ABSTRACTA velvet multisubunit complex was recently detected in the filamentous fungusPenicillium chrysogenum, the major industrial producer of the β-lactam antibiotic penicillin. Core components of this complex areP. chrysogenumVelA (PcVelA) and PcLaeA, which regulate secondary metabolite production, hyphal morphology, conidiation, and pellet formation. Here we describe the characterization of PcVelB, PcVelC, and PcVosA as novel subunits of this velvet complex. Using yeast two-hybrid analysis and bimolecular fluorescence complementation (BiFC), we demonstrate that all velvet proteins are part of an interaction network. Functional analyses using single- and double-knockout strains clearly indicate that velvet subunits have opposing roles in the regulation of penicillin biosynthesis and light-dependent conidiation. PcVelC, together with PcVelA and PcLaeA, activates penicillin biosynthesis, while PcVelB represses this process. In contrast, PcVelB and PcVosA promote conidiation, while PcVelC has an inhibitory effect. Our genetic analyses further show that light-dependent spore formation depends not only on PcVelA but also on PcVelB and PcVosA. The results provided here contribute to our fundamental understanding of the function of velvet subunits as part of a regulatory network mediating signals responsible for morphology and secondary metabolism and will be instrumental in generating mutants with newly derived properties that are relevant to strain improvement programs.
Divergence of Erv1-Associated Mitochondrial Import and Export Pathways in Trypanosomes and Anaerobic Protists
Authors: Basu Somsuvro , Leonard Joanne C. , Desai Nishal , Mavridou Despoina A. I. , Tang Kong Ho , Goddard Alan D. , Ginger Michael L. , Lukeš Julius , Allen James W. A. 
Published: December 2012

ABSTRACT

In yeast (
Saccharomyces cerevisiae
) and animals, the sulfhydryl oxidase Erv1 functions with Mia40 in the import and oxidative folding of numerous cysteine-rich proteins in the mitochondrial intermembrane space (IMS). Erv1 is also required for Fe-S cluster assembly in the cytosol, which uses at least one mitochondrially derived precursor. Here, we characterize an essential Erv1 orthologue from the protist
Trypanosoma brucei
(TbERV1), which naturally lacks a Mia40 homolog. We report kinetic parameters for physiologically relevant oxidants cytochrome
c
and O
2
, unexpectedly find O
2
and cytochrome
c
are reduced simultaneously, and demonstrate that efficient reduction of O
2
by TbERV1 is not dependent upon a simple O
2
channel defined by conserved histidine and tyrosine residues. Massive mitochondrial swelling following Tb
ERV1
RNA interference (RNAi) provides evidence that trypanosome Erv1 functions in IMS protein import despite the natural absence of the key player in the yeast and animal import pathways, Mia40. This suggests significant evolutionary divergence from a recently established paradigm in mitochondrial cell biology. Phylogenomic profiling of genes also points to a conserved role for TbERV1 in cytosolic Fe-S cluster assembly. Conversely, loss of genes implicated in precursor delivery for cytosolic Fe-S assembly in
Entamoeba
,
Trichomonas
, and
Giardia
suggests fundamental differences in intracellular trafficking pathways for activated iron or sulfur species in anaerobic versus aerobic eukaryotes.