bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forever competent: deep‐sea bivalves are colonized by their chemosynthetic symbionts throughout their lifetime
Authors: Wentrup Cecilia , Wendeberg Annelie , Schimak Mario , Borowski Christian , Dubilier Nicole 
Published: August 2014

SummarySymbiotic bivalves at hydrothermal vents and cold seeps host chemosynthetic bacteria intracellularly in gill cells. In bivalves, the gills grow continuously throughout their lifetime by forming new filaments. We examined how newly developed gill tissues are colonized in bivalves with horizontal and vertical symbiont transmission (Bathymodiolus mussels versus a vesicoymid clam) using fluorescence in situ hybridization and transmission electron microscopy. Symbiont colonization was similar in mussels and clams and was independent of the transmission modes. Symbionts were absent in the growth zones of the gills, indicating that symbionts colonize newly formed gill filaments de novo after they are formed and that gill colonization is a continuous process throughout the host's lifetime. Symbiont abundance and distribution suggested that colonization is shaped by the developmental stage of host cells. Self‐infection, in which new gill cells are colonized by symbionts from ontogenetically older gill tissues, may also play a role. In mussels, symbiont infection led to changes in gill cell structure similar to those described from other epithelial cells infected by intracellular pathogens, such as the loss of microvilli. A better understanding of the factors that affect symbiont colonization of bivalve gills could provide new insights into interactions between intracellular bacteria and epithelial tissues.
Modelling the emergent dynamics and major metabolites of the human colonic microbiota
Authors: Kettle Helen , Louis Petra , Holtrop Grietje , Duncan Sylvia H. , Flint Harry J. 
Published: August 2014

SummaryWe present here a first attempt at modelling microbial dynamics in the human colon incorporating both uncertainty and adaptation. This is based on the development of a Monod‐equation based, differential equation model, which produces computer simulations of the population dynamics and major metabolites of microbial communities from the human colon. To reduce the complexity of the system, we divide the bacterial community into 10 bacterial functional groups (BFGs) each distinguished by its substrate preferences, metabolic pathways and its preferred pH range. The model simulates the growth of a large number of bacterial strains and incorporates variation in microbiota composition between people, while also allowing succession and enabling adaptation to environmental changes. The model is shown to reproduce many of the observed changes in major phylogenetic groups and key metabolites such as butyrate, acetate and propionate in response to a one unit pH shift in experimental continuous flow fermentors inoculated with human faecal microbiota. Nevertheless, it should be regarded as a learning tool to be updated as our knowledge of bacterial groups and their interactions expands. Given the difficulty of accessing the colon, modelling can play an extremely important role in interpreting experimental data and predicting the consequences of dietary modulation.
EsrC, an envelope stress‐regulated repressor of the mexCD‐oprJ multidrug efflux operon in Pseudomonas aeruginosa
Authors: Purssell Andrew , Fruci Michael , Mikalauskas Alaya , Gilmour Christie , Poole Keith 
Published: August 2014

SummarymexCD‐oprJ is an envelope stress‐inducible multidrug efflux operon of Pseudomonas aeruginosa. A gene encoding a homologue of the NfxB repressor of this operon, PA4596, occurs downstream of oprJ and was proposed as a second repressor of this efflux operon. Inactivation of this gene had no impact on mexCD‐oprJ expression in cells not exposed to envelope stress although its loss under envelope stress conditions yielded a > 10‐fold increase in mexCD‐oprJ expression. Consistent with PA4596 functioning as a mexCD‐oprJ repressor, the purified protein was able to bind to a DNA fragment carrying the mexCD‐oprJ promoter region. Expression of PA4596 was induced under conditions of envelope stress dependent on the AlgU envelope stress sigma factor, consistent with PA4596 operating under envelope stress conditions where it possibly serves to moderate envelope stress‐inducible mexCD‐oprJ expression. nfxB mutants showed elevated PA4596 expression and purified NfxB bound to DNA encompassing the PA4596 upstream region, an indication that NfxB functions as a repressor of PA4596 expression. Elimination of PA4596 in P. aeruginosa lacking nfxB and hyperexpressing mexCD‐oprJ had no additional impact on mexCD‐oprJ expression, regardless of the presence of envelope stress, suggesting that PA4596 repressor activity may be dependent on NfxB. This envelope stress‐regulated repressor of mexCD‐oprJ has been renamed esrC.
XacR – a novel transcriptional regulator of D‐xylose and L‐arabinose catabolism in the haloarchaeon Haloferax volcanii
Authors: Johnsen Ulrike , Sutter Jan‐Moritz , Schulz Anne‐Christine , Tästensen Julia‐Beate , Schönheit Peter 
Published: August 2014

SummaryThe haloarchaeon Haloferax volcanii degrades D‐xylose and L‐arabinose via oxidative pathways to α‐ketoglutarate. The genes involved in these pathways are clustered and were transcriptionally upregulated by both D‐xylose and L‐arabinose suggesting a common regulator. Adjacent to the gene cluster, a putative IclR‐like transcriptional regulator, HVO_B0040, was identified. It is shown that HVO_B0040, designated xacR, encodes an activator of both D‐xylose and L‐arabinose catabolism: in ΔxacR cells, transcripts of genes involved in pentose catabolism could not be detected; transcript formation could be recovered by complementation, indicating XacR dependent transcriptional activation. Upstream activation promoter regions and nucleotide sequences that were essential for XacR‐mediated activation of pentose‐specific genes were identified by in vivo deletion and scanning mutagenesis. Besides its activator function XacR acted as repressor of its own synthesis: xacR deletion resulted in an increase of xacR promoter activity. A palindromic sequence was identified at the operator site of xacR promoter, and mutation of this sequence also resulted in an increase and thus derepression of xacR promoter activity. It is concluded that the palindromic sequence represents the binding site of XacR as repressor. This is the first report of a transcriptional regulator of pentose catabolism in the domain of archaea.
Explaining Price Dispersion and Dynamics in Laboratory Bertrand Markets
Authors: Bayer Ralph‐C. , Wu Hang , Chan Mickey 
Published: August 2014

AbstractThis paper proposes a quantal response learning model to explain sellers' pricing and learning behaviour observed in a laboratory Bertrand market experiment. In the model, sellers hold beliefs about their opponents' strategies and play quantal best responses to these beliefs. After each round, sellers update their beliefs based on the information learned from previous play. The results indicate that when sellers have full past price information, the model explains the price distributions within periods and the dynamics across periods. The fit is particularly good if one allows for sellers being risk averse. In contrast, quantal response equilibrium does not work well.
When do Structured Funds become too Good to be True? An Experiment
Authors: Breaban Adriana , Matallín‐Sáez Juan Carlos , Barreda‐Tarrazona Iván , Balaguer‐Franch Mª Rosario 
Published: August 2014

AbstractIn this experiment, structured funds are sequentially offered to investors as an alternative to bonds. Our results show that the order in which information is presented generates significant biases in decision‐making. These biases can have both positive and negative consequences on investors' financial behaviour. In fact, when the investment alternatives are made easier to compare, ‘too good to be true’ offers are more easily spotted. Simultaneously, when funds' expected performance shows an apparently positive trend, funds are more often chosen. The ‘too good to be true’ effect is alleviated by high transparency of the information on the funds return.
Use of Strategy Methods in Experimental Pivotal‐Voting Game
Authors: Kuo Yen , Wang Joseph Tao‐yi 
Published: August 2014

AbstractWe use the strategy method to conduct laboratory experiments on a nine‐player heterogeneous‐cost voting game. We replicate the underdog and competition effect, but find significantly higher voter turnout rates to be only partially explained by logit quantal response equilibrium. We examine round‐by‐round changes in cut‐off behaviour and find that voters are highly responsive to historical pivotal events. Voters also respond to past winning and tying, but only as a minority (upsetting the majority), demonstrating an ‘underdog winning effect’, receiving extra utility when winning as a minority. An equilibrium with such asymmetry in utility explains the high minority turnout (and high majority turnout as a best response).
Claims to legitimacy count: Why sanctions fail to instigate democratisation in authoritarian regimes
Authors: Grauvogel Julia , von Soest Christian 
Published: August 2014

AbstractInternational sanctions are one of the most commonly used tools to instigate democratisation in the post‐Cold War era. However, despite long‐term sanction pressure by the European Union, the United States and/or the United Nations, non‐democratic rule has proven to be extremely persistent. Which domestic and international factors account for the regimes' ability to resist external pressure? Based on a new global dataset on sanctions from 1990 to 2011, the results of a fuzzy set qualitative comparative analysis (fsQCA) provide new insights for the research on sanctions and on authoritarian regimes. Most significantly, sanctions strengthen authoritarian rule if the regime manages to incorporate their existence into its legitimation strategy. Such an unintended ‘rally‐round‐the‐flag’ effect occurs where sanctions are imposed on regimes that possess strong claims to legitimacy and have only limited economic and societal linkages to the sender of sanctions.
Who's behind that mask and cape? The Asian leopard cat's Agouti (ASIP) allele likely affects coat colour phenotype in the Bengal cat breed
Authors: Gershony L. C. , Penedo M. C. T. , Davis B. W. , Murphy W. J. , Helps C. R. , Lyons L. A. 
Published: August 2014

SummaryCoat colours and patterns are highly variable in cats and are determined mainly by several genes with Mendelian inheritance. A 2‐bp deletion in agouti signalling protein (ASIP) is associated with melanism in domestic cats. Bengal cats are hybrids between domestic cats and Asian leopard cats (Prionailurus bengalensis), and the charcoal coat colouration/pattern in Bengals presents as a possible incomplete melanism. The complete coding region of ASIP was directly sequenced in Asian leopard, domestic and Bengal cats. Twenty‐seven variants were identified between domestic and leopard cats and were investigated in Bengals and Savannahs, a hybrid with servals (Leptailurus serval). The leopard cat ASIP haplotype was distinguished from domestic cat by four synonymous and four non‐synonymous exonic SNPs, as well as 19 intronic variants, including a 42‐bp deletion in intron 4. Fifty‐six of 64 reported charcoal cats were compound heterozygotes at ASIP, with leopard cat agouti (APbe) and domestic cat non‐agouti (a) haplotypes. Twenty‐four Bengals had an additional unique haplotype (A2) for exon 2 that was not identified in leopard cats, servals or jungle cats (Felis chaus). The compound heterozygote state suggests the leopard cat allele, in combination with the recessive non‐agouti allele, influences Bengal markings, producing a darker, yet not completely melanistic coat. This is the first validation of a leopard cat allele segregating in the Bengal breed and likely affecting their overall pelage phenotype. Genetic testing services need to be aware of the possible segregation of wild felid alleles in all assays performed on hybrid cats.
Transanal haemorrhoidal dearterialization for the treatment of grade III and IV haemorrhoids: a 3‐year experience
Authors: Loganathan Arun , Das Atandrilla , Luck Andrew , Hewett Peter 
Published: August 2014

AbstractBackgroundTransanal haemorrhoidal dearterialization (THD) is increasingly perceived as an effective and better tolerated alternative to excisional haemorrhoidectomy. The aim of this study was to evaluate outcomes and the patient experience of THD in an Australian population with grade III or IV haemorrhoids.MethodsA retrospective review of prospectively maintained database on patients who had undergone THD over a 3‐year period was performed. Data were collected on demographics, operative data, complications, recurrences and readmissions, postoperative pain and further interventions. Patient perceptions and satisfaction with the procedure were assessed with a telephone survey.ResultsA total of 85 patients with a mean age of 55 (±14) years with grade III (85%) or grade IV (15%) haemorrhoids underwent THD. Indications for surgery were predominantly bleeding (87%) and prolapse (41%). Median outpatients follow‐up was 42 days and median telephone follow‐up was 802 days. Median operating time was 25 min (±12). Twenty‐four per cent of patients suffered complications, including postoperative bleeding (7%), constipation (7%), local sepsis (6%), anal fissure (5%) and temporary incontinence (2%). Severe postoperative pain occurred in 16% of the patients. The symptom recurrence rate was 19% and reintervention rate was 14%. About 98.8% of patients reported good or excellent overall satisfaction with the procedure.ConclusionTHD is a relatively new technique for the treatment of haemorrhoids, which is increasingly being used as an alternative to excisional haemorrhoidectomy. This study shows that patients' satisfaction with THD is high despite a moderate complication and recurrence rate and significant incidence of postoperative pain.
Modified elliptical rotation flap for sacrococcygeal pilonidal sinus disease
Authors: Dizen Hayrettin , Yoldas Ömer , Yıldız Mustafa , Cilekar Murat , Dilektaşlı Evren 
Published: August 2014

AbstractBackgroundAlthough various surgical procedures have been described for pilonidal sinus disease, the best surgical technique is still controversial. The aim of this study was to evaluate the short‐term results of modified elliptical rotation flap (MERF) for pilonidal sinus disease in terms of post‐operative complications, recurrence and quality of life.MethodData of 121 patients (10 women, 111 men) who were operated on for sacrococcygeal pilonidal sinus disease between 2011 and 2013 were analysed. Elliptical rotation flap procedure which was described by Nessar et al. was modified. Complications, quality of life and recurrence were evaluated.ResultsThe mean operating time was 31 (range, 20–55) min. The mean time for complete healing was 2.26 ± 0.72 weeks. The mean time for returning to daily activities was 9.0 ± 2.2 days. There were no flap necrosis and recurrence. Post‐operative infection developed in five (4.1%) patients, which was managed by removal of a few skin sutures, drainage and prolonged antibiotic use. Four patients (3.3%) developed a seroma, three of them having a partial wound dehiscence (2.5%). Neither haematoma formation nor complete dehiscence were observed.ConclusionMERF seems to be an effective and reliable procedure having low morbidity rates and no recurrence. Further prospective randomized studies comparing the MERF with other flap techniques will provide better information about the technique.
Changes in middle cerebral artery velocimetry of fetuses diagnosed postnatally with mild or moderate hemolytic disease
Authors: Simetka Ondrej , Petros Michal , Lubusky Marek , Liska Miroslav , Dolezalkova Erika , Matura David , Wiedermannova Hana , Procházka Martin 
Published: August 2014

AbstractObjectivesTo determine the longitudinal trends of middle cerebral artery peak systolic velocity (MCA PSV) in fetuses with mild or moderate hemolytic disease according to the need for postnatal therapy.DesignProspective cohort study.SettingUniversity referral center.SampleTwenty‐three fetuses from singleton alloimmunized pregnancies.MethodsSerial measurements of MCA PSV were performed. After delivery, newborns were grouped by the need for postnatal management into mild hemolytic disease, which required no or only phototherapy (n = 14, group 1), and moderate hemolytic disease, where postnatal top‐up or exchange transfusions were required (n = 9, group 2).Main outcome measuresSerial Doppler MCA PSV data transformed to multiples of the median, analyzed with linear regression and exponential models.ResultsWe performed 83 measurements in group 1: 3‐8 per fetus; mean GA at inclusion, 23 weeks and 65 measurements in group 2: 4‐15 per fetus; mean GA at inclusion, 22 weeks. The estimated mean slopes of the MCA PSVs increased with the degree of postnatal therapy required (group 1: MCA PSV = 0.003 GA + 1.298; group 2: MCA PSV = 0.035 GA + 0.436). The relative average increments (RAI) were 4.7% and 7.1%, respectively. The two groups exhibited significant differences in mean slope and RAI (p<0.05).ConclusionsFetuses that required postnatal transfusions due to hemolytic disease showed an enhanced progressive increase in MCA PSVs compared to those without transfusion requirement. This information might enable their identification during pregnancy.
Cell‐mediated immune response: a clinical review of the therapeutic potential of human papillomavirus vaccination
Authors: Meyer Sonja Izquierdo , Fuglsang Katrine , Blaakaer Jan 
Published: August 2014

AbstractObjectiveThis clinical review aims to assess the efficacy of human papillomavirus 16/18 (HPV16/18) vaccination on the cell‐mediated immune response in women with existing cervical intraepithelial neoplasia or cervical cancer induced by HPV16 or HPV18.Data sources and study selectionA focused and thorough literature search conducted in five different databases found 996 publications. Six relevant articles were chosen for further review. In total, 154 patients (>18 years of age) were enrolled in prospective study trials with 3–15 months of follow up. The vaccine applications were administered two to four times. The vaccines contained different combinations of HPV16 and HPV18 and early proteins, E6 and E7. The primary outcome was the cell‐mediated immune response. Correlation to clinical outcome (histopathology) and human leukocyte antigen genes were secondary endpoints.ResultsAll vaccines triggered a detectable cell‐mediated immune response, some of which were statistically significant. Correlations between immunological response and clinical outcome (histopathology) were not significant, so neoplasms may not be susceptible to vaccine‐generated cytotoxic T cells (CD8+).ConclusionsProphylactic HPV vaccines have been introduced to reduce the incidence of cervical cancer in young women. Women already infected with HPV could benefit from a therapeutic HPV vaccination. Hence, it is important to continue the development of therapeutic HPV vaccines to lower the rate of HPV‐associated malignancies and crucial to evaluate vaccine efficacy clinically. This clinical review represents an attempt to elucidate the theories supporting the development of an HPV vaccine with a therapeutic effect on human papillomavirus‐induced malignancies of the cervix.
Does screening for Down's syndrome cause anxiety in pregnant women? A systematic review
Authors: Lou Stina , Mikkelsen Line , Hvidman Lone , Petersen Olav B. , Nielsen Camilla Palmhøj 
Published: August 2014

AbstractBackgroundPrenatal screening for Down's syndrome and other chromosomal abnormalities is included in prenatal care programs in many countries. However, the potential association between prenatal screening and maternal anxiety remains an issue of debate.ObjectiveTo systematically review and summarize the current scientific evidence on whether screening for Down's syndrome might cause anxiety in pregnant women with a negative or a false‐positive screening result.MethodsFive databases (PubMed, Embase, Cinahl, PsychInfo and Cochrane) were systematically searched for randomized controlled trials or cohort studies comparing screening and no screening, or comparing different types of screening for Down's syndrome. The search was limited to studies published between September 2001 and April 2013. In all, 316 studies were identified through search of databases and 40 were included for full‐text assessment. Two observers independently screened the articles and seven studies satisfied the inclusion criteria. They were subsequently assessed for risk of bias and level of evidence.Main outcome measuresQuantitative measurements of maternal anxiety or worry.ResultsTwo studies compared anxiety in pregnant women who accepted or declined screening and showed no difference between groups. All studies described a decrease in anxiety following a screen‐negative result. Four studies reported that women's anxiety levels increased significantly upon receiving a screen‐positive result. However, after a normal diagnostic result, anxiety levels declined to the same level as for screen‐negative women.ConclusionStudies using quantitative, validated measures to estimate anxiety showed no association between screening and residual anxiety.
Identifying functional co‐activation patterns in neuroimaging studies via poisson graphical models
Authors: Xue Wenqiong , Kang Jian , Bowman F. DuBois , Wager Tor D. , Guo Jian 
Published: August 2014

SummaryStudying the interactions between different brain regions is essential to achieve a more complete understanding of brain function. In this article, we focus on identifying functional co‐activation patterns and undirected functional networks in neuroimaging studies. We build a functional brain network, using a sparse covariance matrix, with elements representing associations between region‐level peak activations. We adopt a penalized likelihood approach to impose sparsity on the covariance matrix based on an extended multivariate Poisson model. We obtain penalized maximum likelihood estimates via the expectation‐maximization (EM) algorithm and optimize an associated tuning parameter by maximizing the predictive log‐likelihood. Permutation tests on the brain co‐activation patterns provide region pair and network‐level inference. Simulations suggest that the proposed approach has minimal biases and provides a coverage rate close to 95% of covariance estimations. Conducting a meta‐analysis of 162 functional neuroimaging studies on emotions, our model identifies a functional network that consists of connected regions within the basal ganglia, limbic system, and other emotion‐related brain regions. We characterize this network through statistical inference on region‐pair connections as well as by graph measures.