bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial and temporal genetic structure of Symbiodinium populations within a common reef‐building coral on the Great Barrier Reef
Authors: Howells Emily J. , Willis Bette L. , Bay Line K. , van Oppen Madeleine J. H. 
Published: June 2013

AbstractThe dinoflagellate photosymbiont Symbiodinium plays a fundamental role in defining the physiological tolerances of coral holobionts, but little is known about the dynamics of these endosymbiotic populations on coral reefs. Sparse data indicate that Symbiodinium populations show limited spatial connectivity; however, no studies have investigated temporal dynamics for in hospite Symbiodinium populations following significant mortality and recruitment events in coral populations. We investigated the combined influences of spatial isolation and disturbance on the population dynamics of the generalist Symbiodinium type C2 (ITS1 rDNA) hosted by the scleractinian coral Acropora millepora in the central Great Barrier Reef. Using eight microsatellite markers, we genotyped Symbiodinium in a total of 401 coral colonies, which were sampled from seven sites across a 12‐year period including during flood plume–induced coral bleaching. Genetic differentiation of Symbiodinium was greatest within sites, explaining 70–86% of the total genetic variation. An additional 9–27% of variation was explained by significant differentiation of populations among sites separated by 0.4–13 km, which is consistent with low levels of dispersal via water movement and historical disturbance regimes. Sampling year accounted for 6–7% of total genetic variation and was related to significant coral mortality following severe bleaching in 1998 and a cyclone in 2006. Only 3% of the total genetic variation was related to coral bleaching status, reflecting generally small (8%) reductions in allelic diversity within bleached corals. This reduction probably reflected a loss of genotypes in hospite during bleaching, although no site‐wide changes in genetic diversity were observed. Combined, our results indicate the importance of disturbance regimes acting together with limited oceanographic transport to determine the genetic composition of Symbiodinium types within reefs.
Characterization of IBS‐like symptoms in patients with ulcerative colitis in clinical remission
Authors: Jonefjäll B. , Strid H. , Öhman L. , Svedlund J. , Bergstedt A. , Simren M. 
Published: June 2013

AbstractBackgroundGastrointestinal symptoms compatible with Irritable Bowel Syndrome (IBS) are common in patients with inflammatory bowel disease. It has been suggested that these symptoms are a reflection of occult inflammation rather than coexisting IBS. The aim of this study was to characterize IBS‐like symptoms in patients with Ulcerative Colitis (UC) in clinical remission by assessing inflammatory markers, psychological symptoms, and quality of life.MethodsNinety‐four patients with new onset of UC were followed prospectively during 3 years with yearly follow‐up visits. The patients completed self‐administrated questionnaires. Fecal calprotectin was used as an inflammatory biomarker. Remission was defined as a total Mayo‐score ≤2 and an endoscopic subscore ≤1, with no relapse during the 3‐month period prior to visit.Key ResultsThe prevalence of patients that fulfilled Rome II criteria for IBS among UC patients in remission was 11% at visit 1, 23% at visit 2, and 17% at visit 3. When comparing UC patients in remission with and without IBS‐like symptom, patients with IBS‐like symptoms had more severe gastrointestinal symptoms, tendencies toward more severe psychological symptoms and reduced levels of quality of life, but the calprotectin levels did not differ between the two groups.Conclusions & InferencesIBS‐like symptoms are common in patients with UC in clinical remission and these fluctuate over time. The symptoms are associated with poor psychological well‐being and reduced quality of life, and do not seem to be a reflection of low‐grade inflammatory activity.
Involvement of lipoprotein PpiA of Streptococcus gordonii in evasion of phagocytosis by macrophages
Authors: Cho K. , Arimoto T. , Igarashi T. , Yamamoto M. 
Published: June 2013

SummaryStreptococcus gordonii is a commensal gram‐positive bacterium that resides in the human oral cavity, and is one of the most common causes of infective endocarditis (IE). Bacterial surface molecules play an important role in establishing IE, and several S. gordonii proteins have been implicated in binding to host cells during the establishment of IE. In this study, we identified a putative lipoprotein, peptidyl‐prolyl cis/trans isomerase (PpiA), and clarified its role in evasion of phagocytosis by macrophages. Attenuation of the gene encoding prolipoprotein diacylglyceryl transferase (Lgt) altered the localization of PpiA from the cell surface to the culture supernatant, indicating that PpiA is lipid‐anchored in the cell membrane by Lgt. Both human and murine macrophages showed higher phagocytic activity towards ppiA and lgt mutants than the wild‐type, indicating that the presence of PpiA suppresses phagocytosis of S. gordonii. Human macrophages treated with dextran sulfate had significantly impaired phagocytosis of S. gordonii, suggesting that class A scavenger receptors in human macrophages are involved in the phagocytosis of S. gordonii. These results provide evidence that S. gordonii lipoprotein PpiA plays an important role in inhibiting phagocytic engulfment and in evasion of the host immune response.
Gene use restriction technologies for transgenic plant bioconfinement
Authors: Sang Yi , Millwood Reginald J. , Neal Stewart Jr C. 
Published: June 2013

SummaryThe advances of modern plant technologies, especially genetically modified crops, are considered to be a substantial benefit to agriculture and society. However, so‐called transgene escape remains and is of environmental and regulatory concern. Genetic use restriction technologies (GURTs) provide a possible solution to prevent transgene dispersal. Although GURTs were originally developed as a way for intellectual property protection (IPP), we believe their maximum benefit could be in the prevention of gene flow, that is, bioconfinement. This review describes the underlying signal transduction and components necessary to implement any GURT system. Furthermore, we review the similarities and differences between IPP‐ and bioconfinement‐oriented GURTs, discuss the GURTs’ design for impeding transgene escape and summarize recent advances. Lastly, we go beyond the state of the science to speculate on regulatory and ecological effects of implementing GURTs for bioconfinement.
Modelling stomatal conductance in response to environmental factors
Authors: BUCKLEY THOMAS N. , MOTT KEITH A. 
Published: June 2013

AbstractStomata are an attractive system for modellers for many reasons, and the literature contains a large number of papers describing models that predict stomatal conductance as a function of environmental factors. The approaches and goals of these models vary considerably. This review summarizes these different approaches and discusses their strengths and weaknesses with a focus on mechanistically based models. The critical unresolved questions are highlighted and placed in the context of current research on stomatal physiology. Finally, directions for future research are considered.
How do trees die? A test of the hydraulic failure and carbon starvation hypotheses
Authors: SEVANTO SANNA , MCDOWELL NATE G. , DICKMAN L. TURIN , PANGLE ROBERT , POCKMAN WILLIAM T. 
Published: June 2013

AbstractDespite decades of research on plant drought tolerance, the physiological mechanisms by which trees succumb to drought are still under debate. We report results from an experiment designed to separate and test the current leading hypotheses of tree mortality. We show that piñon pine (Pinus edulis) trees can die of both hydraulic failure and carbon starvation, and that during drought, the loss of conductivity and carbohydrate reserves can also co‐occur. Hydraulic constraints on plant carbohydrate use determined survival time: turgor loss in the phloem limited access to carbohydrate reserves, but hydraulic control of respiration prolonged survival. Our data also demonstrate that hydraulic failure may be associated with loss of adequate tissue carbohydrate content required for osmoregulation, which then promotes failure to maintain hydraulic integrity.
Response to competition of bulbous geophyteAllium oleraceumdiffering in ploidy level
Authors: Fialová M. , Duchoslav M. 
Published: June 2013

AbstractExperimental studies that explore the possible causes of ploidy distributions and niche differentiation are rare. Increased competitive ability may be advantageous for survival in dense vegetation and may strongly affect local and regional abundances of cytotypes and potentially contribute to invasion success. We compared survival, growth and reproduction of plants originating from bulbils of three cytotypes (2n = 4x, 5x, 6x) ofAllium oleraceumgrowing with and without a competitor (Arrhenatherum elatius). There was a strong negative effect of competition but no effect of ploidy or ploidy × competition on survivorship, height and total dry mass ofA. oleraceum,i.e. no support for different competitive abilities of the ploidy levels. However, slightly different responses of populations to competition treatments within all cytotypes suggest differentiation within cytotypes. Under competition, plant survivorship was low, surviving plants were small, had low dry mass and produced neither sexual nor asexual propagules. Without competition, plant survivorship was high, and cytotypes differed in three traits after 2 year's growth: dry mass of flowers, number of flowers and ratio of the dry mass of sexual to asexual propagules all decreased with increasing ploidy level. We additionally tested tetra‐ and pentaploids as to whether plants originating from different types of propagule (bulbils, seeds) differ in survivorship, growth and reproduction when growing with and without a competitor. Plants originating from bulbils had higher survivorship, were more robust, flowered earlier and produced more propagules when compared to plants originating from seeds and grown without competition. Under competition, differences in performance between plants originating from seeds and bulbils mostly disappeared, with higher survivorship only for plants originating from bulbils.
Coordinated action of β‐galactosidases in the cell wall of embryonic axes during chickpea germination and seedling growth
Authors: Hernández‐Nistal J. , Martín I. , Dopico B. , Labrador E. 
Published: June 2013

AbstractThe plant cell wall is a dynamic structure whose constant modification is necessary for plant cells to grow and divide. In the cell walls of chickpea (Cicer arietinum) there are at least four β‐galactosidases, whose presence and location in embryonic axes during the first 48 h of seed imbibition are discussed in this paper. We examined their roles as cell wall‐modifying enzymes in germinative and/or post‐germinative events. At the start of germination, only βV‐Gal, and to a lesser extent βIV‐Gal, appear in the axes before rupture of the testa, suggesting they are related to germination sensu stricto. Once the testa has broken, the four β‐galactosidases are involved in growth and differentiation of the axes. Immunolocation of the different proteins in axes, which in part confirms previous results in seedlings and plants, allows assignment of post‐germinative roles to βI‐Gal and βIII‐Gal as cell wall modifiers in vascular tissue elements. βIV‐Gal and βV‐Gal participate in the initial events of germination in which cell walls are involved: βV‐Gal in cell proliferation, detachment of root cap cells and initial vascular tissue differentiation; both of them in xylem maturation; and βIV‐Gal in thickening of the primary cell wall. Together with other cell wall‐modifying enzymes, such as expansins and XTH, chickpea galactosidases might function in a sequential order in turnover of the primary cell wall, allowing the elongation of embryonic axes during seed germination.
First reports of Pseudo‐nitzschia micropora and P. hasleana (Bacillariaceae) from the Southern Hemisphere: Morphological, molecular and toxicological characterization
Authors: Ajani Penelope , Murray Shauna , Hallegraeff Gustaaf , Brett Steve , Armand Leanne 
Published: June 2013

SummaryPseudo‐nitzschia H. Peragallo is a marine diatom genus found worldwide in polar, temperate, subtropical and tropical waters. It includes toxigenic representatives that produce domoic acid (DA), a neurotoxin responsible for Amnesic Shellfish Poisoning. In this study we characterized two species of Pseudo‐nitzschia collected from Port Stephens and the Hawkesbury River (south eastern Australia) previously unreported from Australian waters. Clonal isolates were sub‐sampled for (i) light and transmission electron microscopy; (ii) DNA sequencing, based on the nuclear‐encoded partial large subunit ribosomal RNA gene and internal transcribed spacer (ITS)‐ITS1, 5.8S and ITS2 rDNA regions and, (iii) DA production as measured by liquid chromatography‐mass spectrometry. Morphological and molecular data unambiguously revealed the species to be Pseudo‐nitzschia micropora Priisholm, Moestrup & Lundholm (Port Stephens) and Pseudo‐nitzschia hasleana Lundholm (Hawkesbury River). This is the first report of the occurrence of these species from the Southern Hemisphere and the first report of P. micropora in warm‐temperate waters. Cultures of P. micropora, tested for DA production for the first time, proved to be non‐toxic. Similarly, no detectable toxin concentrations were observed for P. hasleana. Species resolution and knowledge on the toxicity of local Pseudo‐nitzschia species has important implications for harmful algal bloom monitoring and management.
Gorillas in the closet? Public and private actors in the enforcement of transnational private regulation
Authors: Verbruggen Paul 
Published: June 2013

AbstractThis paper examines to what extent the background presence of state regulatory capacity – at times referred to as the “regulatory gorilla in the closet” – is a necessary precondition for the effective enforcement of transnational private regulation. By drawing on regulatory regimes in the areas of advertising and food safety, it identifies conditions under which (the potential of) public regulatory intervention can bolster the capacity of private actors to enforce transnational private regulation. These involve the overlap between norms, objectives, and interests of public and private regulation; the institutional design of regulatory enforcement; compliance with due process standards; and information management and data sharing. The paper argues that while public intervention remains important for the effective enforcement of transnational private regulation, governmental actors – both national and international – should create the necessary preconditions to strengthen private regulatory enforcement, as it can also enhance their own regulatory capacity, in particular, in transnational contexts.
Relationship between airway pathophysiology and airway inflammation in older asthmatics
Authors: Porsbjerg Celeste M. , Gibson Peter G. , Pretto Jeffrey J. , Salome Cheryl M. , Brown Nathan J. , Berend Norbert , King Gregory G. 
Published: June 2013

AbstractBackground and objectiveAsthma‐related morbidity is greater in older compared with younger asthmatics. Airway closure is also greater in older asthmatics, an observation that may be explained by differences in airway inflammation. We hypothesized that in older adult patients with asthma, neutrophil airway inflammation increases airway closure during bronchoconstriction, while eosinophil airway inflammation increases airway hyperresponsiveness (AHR).MethodsAsthmatic subjects (n = 26), aged ≥55 years (68% female), were studied, and AHR to 4.5% saline challenge was measured by the response–dose ratio (%fall in forced expiratory volume in 1 s (FEV1)/mg saline). Airway closure was assessed during bronchoconstriction percent change in forced vital capacity (FVC)/percent change in FEV1 (i.e. Closing Index). Airway inflammation was assessed by induced sputum and exhaled nitric oxide (eNO).ResultsMean patient age was 67 years (confidence interval: 63–71) with a mean FEV1 of 78 % predicted (confidence interval: 70–85%). AHR correlated with sputum eosinophils (r = 0.68, P = 0.005) and eNO (r = 0.71, P < 0.001), but not with neutrophils or neutrophil mediators. The Closing Index correlated with total sputum neutrophils (r = 0.66, P = 0.005), neutrophil elastase, matrix metalloproteinase‐9 and interleukin‐8 (all P < 0.05). Further, FEV1/FVC and residual volume/total lung capacity at rest correlated with neutrophil elastase (r = –0.46 and 0.66 respectively, P < 0.05) but not with eosinophils or eNO.ConclusionsIn older patients with asthma, airway inflammatory cells are linked to abnormal airway physiology. Eosinophilic airway inflammation is associated with AHR while neutrophilic inflammation may be an important determinant of airflow limitation at rest and airway closure during bronchoconstriction. The clinical implications of these findings remain to be determined.
Inter‐parent Aggression as a Precursor to Disengagement Coping in Emerging Adulthood: The Buffering Role of Friendship Competence
Authors: Brown Casey L. , Oudekerk Barbara A. , Szwedo David E. , Allen Joseph P. 
Published: June 2013

AbstractUsing multi‐informant data drawn from a prospective study involving 184 youth, mother‐perpetrated and father‐perpetrated partner aggression during early adolescence (the age of 13) was examined as a predictor of five types of disengagement coping strategies in emerging adulthood (the age of 21): behavioral disengagement, mental disengagement, denial, substance use, and restraint. The ability to develop close friendships, or friendship competence, was examined as a moderator of these links. Results suggest that inter‐parent aggression in early adolescence can predict reliance on disengagement coping 8 years later, but that friendship competence can buffer against the reliance on disengagement coping. Moreover, close friendship competence was not directly related to partner aggression by mothers or fathers, suggesting that friendship competence develops along an independent developmental track and thus may truly serve as a buffer for young adults with a history of exposure to inter‐parent aggression.
Constructing Unemployment: Britain and France in Historical Perspective
Authors: Whiteside Noel 
Published: June 2013

AbstractUnemployment emerged as a specific social issue in the late‐19th century, but the nature of the threat it posed and the governing instruments available to address it varied widely. Using Britain and France as strongly contrasting cases, this article demonstrates the variable and historically contingent constructions of unemployment as a problem, and demonstrates how policy to address it was developed using administrative agencies that embodied specific, normative visions of how society and employment should operate. The different governing trajectories through which the issue was tackled is analyzed in terms of the context within which the problem of unemployment originally emerged. The article demonstrates the socio‐political nature of unemployment's construction and, with reference to recent labour market change, questions its utility as a means of assessing economic or social well‐being.
Multiple Genetic Pathways Involving Amino Acid Position 143 of HIV-1 Integrase Are Preferentially Associated with Specific Secondary Amino Acid Substitutions and Confer Resistance to Raltegravir and Cross-Resistance to Elvitegravir
Authors: Huang Wei , Frantzell Arne , Fransen Signe , Petropoulos Christos J. 
Published: June 2013

ABSTRACT
Y143C,R substitutions in HIV-1 integrase define one of three primary raltegravir (RAL) resistance pathways. Here we describe clinical isolates with alternative substitutions at position 143 (Y143A, Y143G, Y143H, and Y143S [Y143A,G,H,S]) that emerge less frequently, and we compare the genotypic and phenotypic profiles of these viruses to Y143C,R viruses to reconcile the preferential selection of Y143C,R variants during RAL treatment. Integrase amino acid sequences and RAL susceptibility were characterized in 117 patient isolates submitted for drug resistance testing and contained Y143 amino acid changes. The influence of specific Y143 substitutions on RAL susceptibility and their preferential association with particular secondary substitutions were further defined by evaluating the composition of patient virus populations along with a large panel of site-directed mutants. Our observations demonstrate that the RAL resistance profiles of Y143A,G,H,S viruses and their association with specific secondary substitutions are similar to the well-established Y143C profile but distinct from the Y143R profile. Y143R viruses differ from Y143A,C,G,H,S viruses in that Y143R confers a greater reduction in RAL susceptibility as a single substitution, consistent with a lower resistance barrier. Among Y143A,C,G,H,S viruses, the higher prevalence of Y143C viruses is the result of a lower genetic barrier than that of the Y143A,G,S viruses and a lower resistance barrier than that of the Y143H viruses. In addition, Y143A,C,G,H,S viruses require multiple secondary substitutions to develop large reductions in RAL susceptibility. Patient-derived viruses containing Y143 substitutions exhibit cross-resistance to elvitegravir.
Analysis of the Small RNA Transcriptional Response in Multidrug-Resistant Staphylococcus aureus after Antimicrobial Exposure
Authors: Howden Benjamin P. , Beaume Marie , Harrison Paul F. , Hernandez David , Schrenzel Jacques , Seemann Torsten , Francois Patrice , Stinear Timothy P. 
Published: June 2013

ABSTRACT

The critical role of noncoding small RNAs (sRNAs) in the bacterial response to changing conditions is increasingly recognized. However, a specific role for sRNAs during antibiotic exposure has not been investigated in
Staphylococcus aureus
. Here, we used Illumina RNA-Seq to examine the sRNA response of multiresistant sequence type 239 (ST239)
S. aureus
after exposure to four antibiotics (vancomycin, linezolid, ceftobiprole, and tigecycline) representing the major classes of antimicrobials used to treat methicillin-resistant
S. aureus
(MRSA) infections. We identified 409 potential sRNAs and then compared global sRNA and mRNA expression profiles at 2 and 6 h, without antibiotic exposure and after exposure to each antibiotic, for a vancomycin-susceptible strain (JKD6009) and a vancomycin-intermediate strain (JKD6008). Exploration of this data set by multivariate analysis using a novel implementation of nonnegative matrix factorization (NMF) revealed very different responses for mRNA and sRNA. Where mRNA responses clustered with strain or growth phase conditions, the sRNA responses were predominantly linked to antibiotic exposure, including sRNA responses that were specific for particular antibiotics. A remarkable feature of the antimicrobial response was the prominence of antisense sRNAs to genes encoding proteins involved in protein synthesis and ribosomal function. This study has defined a large sRNA repertoire in epidemic ST239 MRSA and shown for the first time that a subset of sRNAs are part of a coordinated transcriptional response to specific antimicrobial exposures in
S. aureus
. These data provide a framework for interrogating the role of staphylococcal sRNAs in antimicrobial resistance and exploring new avenues for sRNA-based antimicrobial therapies.