bluuebunny/crossref_metadata_2025_split huggingface dataset:
Root jasmonic acid synthesis and perception regulate folivore‐induced shoot metabolites and increase Nicotiana attenuata resistance
Authors: Fragoso Variluska , Rothe Eva , Baldwin Ian T. , Kim Sang‐Gyu 
Published: March 2014

Summary

While jasmonic acid (JA) signaling is widely accepted as mediating plant resistance to herbivores, and the importance of the roots in plant defenses is recently being recognized, the role of root JA in the defense of above‐ground parts remains unstudied.
To restrict JA impairment to the roots, we micrografted wildtype Nicotiana attenuata shoots to the roots of transgenic plants impaired in JA signaling and evaluated ecologically relevant traits in the glasshouse and in nature.
Root JA synthesis and perception are involved in regulating nicotine production in roots. Strikingly, systemic root JA regulated local leaf JA and abscisic acid (ABA) concentrations, which were associated with differences in nicotine transport from roots to leaves via the transpiration stream. Root JA signaling also regulated the accumulation of other shoot metabolites; together these account for differences in resistance against a generalist, Spodoptera littoralis, and a specialist herbivore, Manduca sexta. In N. attenuata's native habitat, silencing root JA synthesis increased the shoot damage inflicted by Empoasca leafhoppers, which are able to select natural jasmonate mutants. Silencing JA perception in roots also increased damage by Tupiocoris notatus.
We conclude that attack from above‐ground herbivores recruits root JA signaling to launch the full complement of plant defense responses.
Alternative Sites for Right Ventricular Pacing in Chagas Disease: A Comparative Study of the Mid‐Septum and Inflow Tract
Authors: da SILVA JÚNIOR OTAVIANO , BORGES MARIA CÂNDIDA CALZADA , de MELO CELSO SALGADO , NASCENTE GABRIEL ANTONIO NOGUEIRA , CORREIA DALMO 
Published: March 2014

BackgroundThe right ventricular mid‐septum and inflow tract are alternative pacing sites that are potentially less harmful to cardiac function.ObjectiveThis study aimed to analyze the influence of these two alternative pacing sites on the clinical course of patients with chronic Chagas disease, who underwent definitive pacemaker implantation.MethodsA total of 80 patients with Chagas disease and classical indications for definitive pacemaker implantation were randomized into two groups between October 2008 and August 2010: 40 received inflow tract implantation and 40 patients received mid‐septum implantation. The analyzed parameters included: (1) progression stage of chronic chagasic cardiomyopathy (CCC), (2) electrocardiographic analysis, (3) left ventricular remodeling, and (4) electromechanical dyssynchrony. The assessment was performed 24–48 hours after implantation and a follow‐up period of 18 months.ResultsCompared with inflow tract implantation, mid‐septum implantation was associated with slower CCC progression and the generation of narrower QRS complexes (131.8 ± 8.4 milliseconds vs 150.5 ± 10.5 milliseconds; P < 0.01). No left ventricular remodeling was detected. Intraventricular dyssynchrony was more frequent in the inflow tract group than in the mid‐septum group (85% vs 32.5%, respectively; odds ratio [OR], 9.15; P = 0.02) as was interventricular dyssynchrony (37.5% vs 17.5%, respectively; OR, 2.83; P < 0.01).ConclusionsMid‐septum implantation was associated with slower CCC progression, generation of narrower QRS complexes, and lower electromechanical dyssynchrony, suggesting that this pacing site could be less harmful to cardiac function than the inflow tract site in patients with CCC.
No Simples, No Gunk, No Nothing
Authors: Cowling Sam 
Published: March 2014

AbstractMereological realism holds that the world has a mereological structure – i.e. a distribution of mereological properties and relations. In this article, I defendEleaticism about properties, according to which there are no causally inert non‐logical properties. I then present anEleatic argument for mereological anti‐realism, which denies the existence of both mereological composites and mereological simples. After defendingEleaticism and mereological anti‐realism, I argue that mereological anti‐realism is preferable to mereological nihilism. I then conclude by examining the thesis that composition is identity and noting its consequences for the question of mereological structure.
Water relations of Robinia pseudoacacia L.: do vessels cavitate and refill diurnally or are R‐shaped curves invalid in Robinia?
Authors: WANG RUIQING , ZHANG LINGLING , ZHANG SHUOXIN , CAI JING , TYREE MELVIN T. 
Published: March 2014

AbstractSince 2005, an unresolved debate has questioned whether R‐shaped vulnerability curves (VCs) might be an artefact of the centrifuge method of measuring VCs. VCs with R‐shape show loss of stem conductivity from approximately zero tension, and if true, this suggests that some plants either refill embolized vessels every night or function well with a high percentage of vessels permanently embolized. The R‐shaped curves occur more in species with vessels greater than half the length of the segments spun in a centrifuge. Many have hypothesized that the embolism is seeded by agents (bubbles or particles) entering the stem end and travelling towards the axis of rotation in long vessels, causing premature cavitation. VCs were measured on Robinia pseudoacacia L. by three different techniques to yield three different VCs; R‐shaped: Cavitron P50 = 0.30 MPa and S‐shaped: air injection P50 = 1.48 MPa and bench top dehydration P50 = 3.57 MPa. Stem conductivity measured in the Cavitron was unstable and is a function of vessel length when measured repeatedly with constant tension, and this observation is discussed in terms of stability of air bubbles drawn into cut‐open vessels during repeated Cavitron measurement of conductivity; hence, R‐shaped curves measured in a Cavitron are probably invalid.
The Effect of Photodynamic Action on Leakage of Ions Through Liposomal Membranes that Contain Oxidatively Modified Lipids
Authors: Ytzhak Shany , Ehrenberg Benjamin 
Published: March 2014

AbstractSinglet oxygen, created in photosensitization, peroxidizes unsaturated fatty acids of the membrane's lipids. This generates alcoholic or aldehyde groups at double bonds' breakage points. In a previous study, we examined the leakage of a K+‐induced cross‐membrane electric potential of liposomes that undergo photosensitization. The question remains to what extent peroxidized lipids can compromise the stability of the membrane. In this study, we studied the effect of the oxidatively modified lipids PGPC and ALDOPC in the membrane on its stability, by monitoring the membrane electric potential with the potentiometric dye DiSC2(5). As the content of the modified lipids increases the membrane becomes less stable, and even at just 2% of the modified lipids the membrane's integrity is affected, in respect to the leakage of ions through it. When the liposomes that contain the modified lipids undergo photosensitization by hematoporphyrin, the lipid bilayer becomes even more unstable and passage of ions is accelerated. We conclude that the existence of lipids with a shortened fatty acid that is terminated by a carboxylic acid or an aldehyde and more so when photosensitized damage occurs to unsaturated fatty acids in lecithin, add up to a critical alteration of the membrane, which becomes leaky to ions.
Problem gamblers are hyposensitive to wins: An analysis of skin conductance responses during actual gambling on electronic gaming machines
Authors: Lole Lisa , Gonsalvez Craig J. , Barry Robert J. , Blaszczynski Alex 
Published: March 2014

AbstractPhysiological arousal is purportedly a key determinant in the development and maintenance of gambling behaviors, with problem gambling conceptualized in terms of abnormal autonomic responses. Theoretical conceptualizations of problem gambling are discordant regarding the nature of deficit in this disorder; some accounts posit that problem gamblers are hypersensitive to reward, and others that they are hyposensitive to reward and/or punishment. Previous research examining phasic electrodermal responses in gamblers has been limited to laboratory settings, and reactions to real gaming situations need to be examined. Skin conductance responses (SCRs) to losses, wins, and losses disguised as wins (LDWs) were recorded from 15 problem gamblers (PGs) and 15 nonproblem gamblers (NPGs) while they wagered their own money during electronic gaming machine play.PGsdemonstrated significantly reducedSCRsto reward.SCRsto losses andLDWsdid not differ for eitherPGsorNPGs. This hyposensitivity to wins may reflect abnormalities in incentive processing, and may represent a potential biological marker for problem gambling.
Vague Objects with Sharp Boundaries
Authors: Benovsky Jiri 
Published: March 2014

AbstractIn this article I shall consider two seemingly contradictory claims: first, the claim that everybody who thinks that there are ordinary objects has to accept that they are vague, and second, the claim that everybody has to accept the existence of sharp boundaries to ordinary objects. The purpose of this article is of course not to defend a contradiction. Indeed, there is no contradiction because the two claims do not concern the same ‘everybody’. The first claim, that all ordinary objects are vague, is a claim that stems both from common sense intuitions as well as from various types of ontologies of ordinary objects. This puts then pressure on theories of vagueness to account for the vague nature of ordinary objects – but, as we shall see, all theories of vagueness have to accept the existence of sharp thresholds. This is obvious in the case of epistemicism, and it is a well‐known defect of supervaluationism, but as we will see friends of metaphysical vagueness do have to endorse the existence of sharp thresholds in their theory as well. Consequently, there are reasons for dissatisfaction with these accounts, since they do not seem to be able to do the job we asked them to do.
Parameter Estimation for Hidden Markov Models with Intractable Likelihoods
Authors: Dean Thomas A. , Singh Sumeetpal S. , Jasra Ajay , Peters Gareth W. 
Published: March 2014

ABSTRACTApproximate Bayesian computation (ABC) is a popular technique for analysing data for complex models where the likelihood function is intractable. It involves using simulation from the model to approximate the likelihood, with this approximate likelihood then being used to construct an approximate posterior. In this paper, we consider methods that estimate the parameters by maximizing the approximate likelihood used in ABC. We give a theoretical analysis of the asymptotic properties of the resulting estimator. In particular, we derive results analogous to those of consistency and asymptotic normality for standard maximum likelihood estimation. We also discuss how sequential Monte Carlo methods provide a natural method for implementing our likelihood‐based ABC procedures.
Impact of choice of NRTI in first‐line antiretroviral therapy: a cohort analysis of stavudine vs. tenofovir
Authors: Brennan Alana T. , Shearer Kate , Maskew Mhairi , Long Lawrence , Sanne Ian , Fox Matthew P. 
Published: March 2014

AbstractObjectiveIn April 2010, South Africa replaced stavudine with tenofovir in first‐line antiretroviral therapy (ART) despite tenofovir's higher cost. We examined treatment outcomes over 24 months amongst patients initiated on tenofovir‐based vs. stavudine‐based first‐line regimens.MethodsProspective cohort analysis of 3940 patients newly initiating either stavudine‐based (April 2009 to March 2010) or tenofovir‐based (April 2010 to March 2011) ART in Johannesburg, South Africa. Cox proportional hazards models and Fine and Gray's competing risk regression accounting for death were used to model mortality and loss to follow‐up, respectively. Linear and log‐binomial regression were used to evaluate associations with immunologic response and unsuppressed virus (≥400 copies/ml), respectively.ResultsAbout 1878 patients prescribed tenofovir and 2062 patients prescribed stavudine were included. One hundred and sixty‐six (8.8%) tenofovir and 244 (11.8%) stavudine patients died. Three hundred and fifty (18.6%) tenofovir and 379 (18.4%) stavudine patients were lost to follow‐up over 24 months on ART. Adjusted regression models showed tenofovir and stavudine were comparable regarding death, loss to follow‐up, immunologic response and virologic status.ConclusionsWe found no difference in mortality, loss to follow‐up, immunological and virologic outcomes over the first 24‐months on ART associated with tenofovir compared with stavudine.
Thiol‐based redox proteins in abscisic acid and methyl jasmonate signaling in Brassica napus guard cells
Authors: Zhu Mengmeng , Zhu Ning , Song Wen‐yuan , Harmon Alice C. , Assmann Sarah M. , Chen Sixue 
Published: March 2014

SummaryReversibly oxidized cysteine sulfhydryl groups serve as redox sensors or targets of redox sensing that are important in various physiological processes. However, little is known about redox‐sensitive proteins in guard cells and how they function in stomatal signaling. In this study, Brassica napus guard‐cell proteins altered by redox in response to abscisic acid (ABA) or methyl jasmonate (MeJA) were identified by complementary proteomics approaches, saturation differential in‐gel electrophoresis and isotope‐coded affinity tagging. In total, 65 and 118 potential redox‐responsive proteins were identified in ABA‐ and MeJA‐treated guard cells, respectively. All the proteins contain at least one cysteine, and over half of them are predicted to form intra‐molecular disulfide bonds. Most of the proteins fall into the functional groups of ‘energy’, ‘stress and defense’ and ‘metabolism’. Based on the peptide sequences identified by mass spectrometry, 30 proteins were common to ABA‐ and MeJA‐treated samples. A total of 44 cysteines were mapped in the identified proteins, and their levels of redox sensitivity were quantified. Two of the proteins, a sucrose non‐fermenting 1‐related protein kinase and an isopropylmalate dehydrogenase, were confirmed to be redox‐regulated and involved in stomatal movement. This study creates an inventory of potential redox switches, and highlights a protein redox regulatory mechanism in ABA and MeJA signal transduction in guard cells.
A homolog of splicing factor SF1 is essential for development and is involved in the alternative splicing of pre‐mRNA in Arabidopsis thaliana
Authors: Jang Yun Hee , Park Hyo‐Young , Lee Keh Chien , Thu May Phyo , Kim Soon‐Kap , Suh Mi Chung , Kang Hunseung , Kim Jeong‐Kook 
Published: March 2014

SummaryDuring initial spliceosome assembly, SF1 binds to intron branch points and interacts with U2 snRNP auxiliary factor 65 (U2AF65). Here, we present evidence indicating that AtSF1, the Arabidopsis SF1 homolog, interacts with AtU2AF65a and AtU2AF65b, the Arabidopsis U2AF65 homologs. A mutant allele of AtSF1 (At5g51300) that contains a T–DNA insertion conferred pleiotropic developmental defects, including early flowering and abnormal sensitivity to abscisic acid. An AtSF1 promoter‐driven GUS reporter assay showed that AtSF1 promoter activity was temporally and spatially altered, and that full AtSF1 promoter activity required a significant proportion of the coding region. DNA chip analyses showed that only a small proportion of the transcriptome was altered by more than twofold in either direction in the AtSF1 mutant. Expression of the mRNAs of many heat shock proteins was more than fourfold higher in the mutant strain; these mRNAs were among those whose expression was increased most in the mutant strain. An RT–PCR assay revealed an altered alternative splicing pattern for heat shock transcription factor HsfA2 (At2g26150) in the mutant; this altered splicing is probably responsible for the increased expression of the target genes induced by HsfA2. Altered alternative splicing patterns were also detected for the transcripts of other genes in the mutant strain. These results suggest that AtSF1 has functional similarities to its yeast and metazoan counterparts.
In vitro hypercoagulability on whole blood thromboelastometry associated with in vivo reduction of circulating red cell mass in dogs
Authors: McMichael Maureen A. , Smith Stephanie A. , Galligan Alyssa , Swanson Kelly S. 
Published: March 2014

BackgroundPrevious studies have reported a strong correlation between indicators of red cell mass (RCM) and thromboelastometry results (TEM) in several species, specifically an association of apparent hypercoagulability with decreased RCM.ObjectivesThe objectives of the study were to (1) evaluate the effect of decreased circulating RCM on TEM results in dogs, and (2) determine the relative contributions of citrate dilution vs in vivo reduction of RCM to hemostatic potential.Materials and MethodsThirteen healthy dogs had one unit of blood removed on day 0. Whole blood, EDTA, and citrated blood samples for evaluation of TEM variables and PT, APTT, platelet count, fibrinogen, thrombin–antithrombin (TAT), and thrombin generation were collected at baseline, and 3 and 21 days after blood removal. Blood samples were also corrected to a PCV of 45% by adding citrate or removing plasma.ResultsOn day 3 after blood removal, the PCV was significantly decreased (45 ± 6%) compared with baseline (52 ± 6%) and day 21 (50 ± 4%, P < .001), accompanied by TEM variables indicating hypercoagulability, which returned to baseline values by day 21. Other coagulation variables such as PT, APTT, platelet count, TAT, or plasma thrombin generation remained unchanged, with the exception of fibrinogen that was significantly higher on day 3. No changes were related to citrate dilution.ConclusionsTransiently decreased RCM in vivo was accompanied by TEM variables indicating hypercoagulability, which was not confirmed by other coagulation variables. This suggests an artifact of TEM, which presents a potential limitation of this technology in patient populations with abnormal RCM.
Evaluation of the impact of tromethamine edetate disodium dihydrate on antimicrobial susceptibility of Pseudomonas aeruginosa in biofilm in vitro
Authors: Pye Charlotte C. , Singh Ameet , Weese J. Scott 
Published: March 2014

BackgroundBiofilm formation by Pseudomonas aeruginosa has been documented in canine otic isolates. An increase in minimal inhibitory concentration (MIC) for specific antibiotics has been noted for biofilm‐embedded bacteria. Tromethamine edetate disodium dihydrate buffered to pH 8 with tromethamine hydrochloride and deionized water (Triz‐EDTA®) has been documented to potentiate bactericidal activity when used in combination with topical antibiotics, but the impact on biofilm‐embedded bacteria is unknown.Hypothesis/ObjectivesThe objective of this study was to evaluate the impact of Triz‐EDTA® use on in vitro antimicrobial susceptibility of biofilm‐embedded P. aeruginosa.MethodsBiofilm formation was documented using a microtitre plate assay. Broth microdilution was used to assess the MIC of neomycin, polymyxin B, enrofloxacin and gentamicin for the biofilm‐embedded bacteria. The microtitre plate assay was again used to assess the MIC of neomycin, polymyxin B, enrofloxacin and gentamicin for biofilm‐embedded bacteria with added Triz‐EDTA®.ResultsThirty‐one isolates from dogs with otitis were tested. Addition of Triz‐EDTA® significantly reduced MICs for neomycin (P < 0.003) and gentamicin (P < 0.02) but not for polymyxin B (P = 0.3). Enrofloxacin MICs increased in the presence of Triz‐EDTA (P < 0.036).Conclusions and clinical importanceTriz‐EDTA® may be a useful adjunctive treatment for chronic cases of Pseudomonas otitis where biofilms may have developed, if gentamicin or neomycin is to be used as a topical treatment. In vivo study is required to confirm this effect.
Development and antimicrobial susceptibility studies of in vitro monomicrobial and polymicrobial biofilm models with Aspergillus fumigatus and Pseudomonas aeruginosa
Authors: Manavathu Elias K , Vager Dora L , Vazquez Jose A 
Published: March 2014

AbstractBackgroundMixed microbial infections of the respiratory tracts withP. aeruginosaandA. fumigatuscapable of producing biofilms are commonly found in cystic fibrosis patients. The primary objective of this study was to develop anin vitromodel forP. aeruginosaandA. fumigatuspolymicrobial biofilm to study the efficacy of various antimicrobial drugs alone and in combinations against biofilm-embedded cells. Simultaneous static cocultures ofP. aeruginosaand sporelings were used for the development of in vitroP. aeruginosa-A. fumigatuspolymicrobial biofilm in SD broth in 24-well cell culture plates at 35°C, and the biofilm formation was monitored microscopically and spectrophotometrically. UsingP. aeruginosa-A. fumigatussporelings cocultures we examined the effects of various antimicrobial drugs alone and in combination against polymicrobial biofilm by CFU and tetrazolium reduction assays.ResultsIn simultaneous static coculturesP. aeruginosacells killedA. fumigatusconidia, whereas the bacterial cells showed no substantial fungicidal effect on sporelings grown for 12 h or longer at 35°C. Monospecies cultures ofP. aeruginosaproduced loosely adhered monomicrobial biofilm and addition of 10% bovine serum to the growth medium inhibited the formation of monomicrobial biofilm byP. aeruginosawhereas it produced tightly adhered polymicrobial biofilm in the presence ofA. fumigatusmycelial growth.A. fumigatusproduced firmly adherent monomicrobial and polymicrobial biofilms. A comparison of CFU and MTT assays showed that the latter is unsuitable for studying the effectiveness of antimicrobial treatment against polymicrobial biofilm. Tobramycin alone and in combination with posaconazole was highly effective against monomicrobial and polymicrobial biofilms ofP. aeruginosawhereas cefepime alone and in combination with posaconazole showed excellent activity against monomicrobial biofilm ofP. aeruginosabut was less effective against polymicrobial biofilm. Monomicrobial and polymicrobial biofilms ofA. fumigatusshowed similar susceptibility to posaconazole with and without the antibacterial drug.ConclusionsSimultaneous static coculture ofA. fumigatussporelings grown for 12 h or longer was superior to ungerminated conidia withP. aeruginosafor the development ofA. fumigatus-P. aeruginosabiofilm.P. aeruginosa-A. fumigatuspolymicrobial biofilm shows differential susceptibility to antimicrobial drugs whereas the susceptibility ofA. fumigatusto antimicrobial drugs was unchanged.