bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐throughput isolation of giant viruses of the Mimiviridae and Marseilleviridae families in the Tunisian environment
Authors: Boughalmi Mondher , Saadi Hanene , Pagnier Isabelle , Colson Philippe , Fournous Ghislain , Raoult Didier , La Scola Bernard 
Published: December 2012

SummaryGiant viruses of the Megavirales order have been recently isolated from aquatic environments and have long been neglected because they are removed from samples during viral purification for viral metagenomic studies. Due to bacterial overgrowth and susceptibility to high concentrations of antibiotics, isolation by amoeba co‐culture has a low efficiency and is highly time‐consuming. Thus, few environments have been exhaustively investigated to date, although the ubiquitous distribution of the Acanthamoeba sp. suggests that these viruses could also be ubiquitous. In this work, we have implemented a high‐throughput method to detect amoebae lysis on agar plates that allows the testing of hundreds of samples in a few days. Using this procedure, a total of 11 new Marseilleviridae strains and four new Mimiviridae strains, including a virus infected with a virophage, were isolated from 1000 environmental samples from Tunisia. Of these, four corresponded to new genotypic variants. These isolates are the first African environmental isolates identified from these two families, and several samples were obtained from a hypersaline aquatic environment. These results demonstrate that this technique can be used for the evaluation and characterization of large collections of giant viruses to provide insight into understanding their ecology.
The Entner–Doudoroff pathway empowers Pseudomonas putida KT2440 with a high tolerance to oxidative stress
Authors: Chavarría Max , Nikel Pablo I. , Pérez‐Pantoja Danilo , de Lorenzo Víctor 
Published: December 2012

SummaryGlucose catabolism of Pseudomonas putida is carried out exclusively through the Entner–Doudoroff (ED) pathway due to the absence of 6‐phosphofructokinase. In order to activate the Embden–Meyerhof–Parnas (EMP) route we transferred the pfkA gene from Escherichia coli to a P. putida wild‐type strain as well as to an eda mutant, i.e. lacking 2‐keto‐3‐deoxy‐6‐phosphogluconate aldolase. PfkAE. coli failed to redirect the carbon flow from the ED route towards the EMP pathway, suggesting that ED was essential for sugar catabolism. The presence of PfkAE. coli was detrimental for growth, which could be traced to the reduction of ATP and NAD(P)H pools along with alteration of the NAD(P)H/NADP+ ratio. Pseudomonas putida cells carrying PfkAE. coli became highly sensitive to diamide and hydrogen peroxide, the response to which is very demanding of NADPH. The inhibitory effect of PfkAE. coli could in part be relieved by methionine, the synthesis of which relies much on NADPH. These results expose the role of the ED pathway for generating the redox currency (NADPH) that is required for counteracting oxidative stress. It is thus likely that environmental bacteria that favour the ED pathway over the EMP pathway do so in order to gear their aerobic metabolism to endure oxidative‐related insults.
Global Functional Connectivity Abnormalities in Children with Fetal Alcohol Spectrum Disorders
Authors: Wozniak Jeffrey R. , Mueller Bryon A. , Bell Christopher J. , Muetzel Ryan L. , Hoecker Heather L. , Boys Christopher J. , Lim Kelvin O. 
Published: December 2012

BackgroundPrevious studies, including those employing diffusion tensor imaging (DTI), have revealed significant disturbances in the white matter of individuals with fetal alcohol spectrum disorders (FASD). Both macrostructural and microstructural abnormalities have been observed across levels of FASD severity. Emerging evidence suggests that these white matter abnormalities are associated with functional deficits. This study used resting‐state functional MRI (fMRI) to evaluate the status of network functional connectivity in children with FASD compared with control subjects.MethodsParticipants included 24 children with FASD, ages 10 to 17, and 31 matched controls. Neurocognitive tests were administered including Wechsler Intelligence Scales, California Verbal Learning Test (CVLT), and Behavior Rating Inventory of Executive Functioning. High‐resolution anatomical MRI data and 6‐minute resting‐state fMRI data were collected. The resting‐state fMRI data were subjected to a graph theory analysis, and 4 global measures of cortical network connectivity were computed: characteristic path length, mean clustering coefficient, local efficiency, and global efficiency.ResultsResults revealed significantly altered network connectivity in those with FASD. The characteristic path length was 3.1% higher (p = 0.04, Cohen's d = 0.47), and global efficiency was 1.9% lower (p = 0.04, d = 0.63) in children with FASD compared with controls, suggesting decreased network capacity that may have implications for integrative cognitive functioning. Global efficiency was significantly positively correlated with cortical thickness in frontal (r = 0.38, p = 0.005), temporal (r = 0.28, p = 0.043), and parietal (r = 0.36, p = 0.008) regions. No relationship between facial dysmorphology and functional connectivity was observed. Exploratory correlations suggested that global efficiency and characteristic path length are associated with capacity for immediate verbal memory on the CVLT (r = 0.41, p = 0.05 and r = 0.41, p = 0.01, respectively) among those with FASD.ConclusionsResting‐state functional connectivity measures provide new insight into the integrity of brain networks in clinical populations such as FASD. Results demonstrate that children with FASD have alterations in core components of network function and that these aspects of brain integrity are related to measures of structure and cognitive functioning.
Neural network activation during a stop‐signal task discriminates cocaine‐dependent from non‐drug‐abusing men
Authors: Elton Amanda , Young Jonathan , Smitherman Sonet , Gross Robin E. , Mletzko Tanja , Kilts Clinton D. 
Published: December 2012

AbstractCocaine dependence is defined by a loss of inhibitory control over drug‐use behaviors, mirrored by measurable impairments in laboratory tasks of inhibitory control. The current study tested the hypothesis that deficits in multiple subprocesses of behavioral control are associated with reliable neural‐processing alterations that define cocaine addiction. While undergoing functional magnetic resonance imaging (fMRI), 38 cocaine‐dependent men and 27 healthy control men performed a stop‐signal task of motor inhibition. An independent component analysis on fMRI time courses identified task‐related neural networks attributed to motor, visual, cognitive and affective processes. The statistical associations of these components with five different stop‐signal task conditions were selected for use in a linear discriminant analysis to define a classifier for cocaine addiction from a subsample of 26 cocaine‐dependent men and 18 controls. Leave‐one‐out cross‐validation accurately classified 89.5% (39/44; chance accuracy = 26/44 = 59.1%) of subjects with 84.6% (22/26) sensitivity and 94.4% (17/18) specificity. The remaining 12 cocaine‐dependent and 9 control men formed an independent test sample, for which accuracy of the classifier was 81.9% (17/21; chance accuracy = 12/21 = 57.1%) with 75% (9/12) sensitivity and 88.9% (8/9) specificity. The cocaine addiction classification score was significantly correlated with a measure of impulsiveness as well as the duration of cocaine use for cocaine‐dependent men. The results of this study support the ability of a pattern of multiple neural network alterations associated with inhibitory motor control to define a binary classifier for cocaine addiction.
Alcohol drinking and deprivation alter basal extracellular glutamate concentrations and clearance in the mesolimbic system of alcohol‐preferring (P) rats
Authors: Ding Zheng‐Ming , Rodd Zachary A. , Engleman Eric A. , Bailey Jason A. , Lahiri Debomoy K. , McBride William J. 
Published: December 2012

AbstractThe present study determined the effects of voluntary ethanol drinking and deprivation on basal extracellular glutamate concentrations and clearance in the mesolimbic system and tested the hypothesis that chronic ethanol drinking would persistently increase basal glutamate neurotransmission. Three groups of alcohol‐preferring (P) rats were used: ‘water group (WG),’ ‘ethanol maintenance group (MG; 24‐hour free choice water versus 15% ethanol)’ and ‘ethanol deprivation group (DG; 2 weeks of deprivation).’ Quantitative microdialysis and Western blots were conducted to measure basal extracellular glutamate concentrations, clearance and proteins associated with glutamate clearance. Chronic alcohol drinking produced a 70–100% increase of basal extracellular glutamate concentrations in the posterior ventral tegmental area (4.0 versus 7.0 μM) and nucleus accumbens shell (3.0 versus 6.0 μM). Glutamate clearances were reduced by 30–40% in both regions of MG rats compared with WG rats. In addition, Western blots revealed a 40–45% decrease of excitatory amino transporter 1 (EAAT1) protein, but no significant changes in the levels of EAAT2 or cystine‐glutamate antiporter in these regions of MG versus WG rats. The enhanced glutamate concentrations returned to control levels, accompanied by a recovery of glutamate clearance following deprivation. These results indicated that chronic alcohol drinking enhanced extracellular glutamate concentrations in the mesolimbic system, as a result, in part, of reduced clearance, suggesting that enhanced glutamate neurotransmission may contribute to the maintenance of alcohol drinking. However, because the increased glutamate levels returned to normal after deprivation, elevated glutamate neurotransmission may not contribute to the initiation of relapse drinking.
Accuracy of the Dentaport ZX apex locator for working length determination when retreating molar root canals
Authors: Cimilli Hale , Aydemir Seda , Arıcan Burcin , Mumcu Gonca , Chandler Nicholas , Kartal Nevin 
Published: December 2012

AbstractThe aim of this study was to evaluate the accuracy of the Dentaport ZX apex locator for working length determination during root canal retreatment of mandibular molars. Fifteen extracted mandibular first molars with separate mesial canals and apical foraminae and one distal canal were selected. The mesiobuccal and distal canals were investigated; the length with the file tip at the major diameter was defined as the tooth length (TL). The canals were prepared with ProTaper files to 1 mm short of this and filled with gutta‐percha and AH Plus sealer. One week later, the root fillings were removed using ProTaper retreatment files. Tooth length was remeasured and recorded as the retreatment tooth length (RTL). Then electronic measurements were taken at the major (electronic apex locator (EAL) major) and minor (EAL minor) foraminae as suggested by the instrument display. These lengths were compared with RTL and measurements 0.5 and 1 mm short of this distance. For both canals, no significant difference was found between RTL and EAL major, and 0.5 mm short of RTL and EAL minor (P > 0.05). There were significant differences found between all other readings. The Dentaport ZX could not detect the minor foramen accurately but was able to indicate the major foramen in molars undergoing a root canal retreatment procedure.
The association of the effect of lithium in the maintenance treatment of bipolar disorder with lithium plasma levels: a post hoc analysis of a double‐blind study comparing switching to lithium or placebo in patients who responded to quetiapine (Trial 144)
Authors: Nolen Willem A , Weisler Richard H 
Published: December 2012

Nolen WA, Weisler RH. The association of the effect of lithium in the maintenance treatment of bipolar disorder with lithium plasma levels: a post hoc analysis of a double‐blind study comparing switching to lithium or placebo in patients who responded to quetiapine (Trial 144).  Bipolar Disord 2012: 00: 000–000. © 2012 John Wiley & Sons A/S.Published by Blackwell Publishing Ltd.Objectives:  There is no robust proof that the efficacy of lithium in the prevention of manic and depressive episodes in bipolar disorder depends on its plasma level. This analysis aimed to compare the effect of lithium within the presumed therapeutic range of 0.6–1.2 mEq/L and below 0.6 mEq/L with that of placebo.Methods:  We carried out a post hoc analysis of a double‐blind trial in which patients aged ≥18 years with bipolar I disorder (DSM‐IV) who had achieved stabilization from a manic, depressive, or mixed episode during open‐label treatment with quetiapine were randomized to continue quetiapine or to switch to lithium or placebo for up to 104 weeks. Of patients randomized to lithium, 201 obtained median lithium levels between 0.6 and 1.2 mEq/L, and 137 obtained median lithium levels <0.6 mEq/L. Their outcomes were compared with those of patients receiving placebo (n = 404). The primary outcome was time to recurrence of any mood event; additional outcomes included time to recurrence of a manic or depressive event.Results:  Times to recurrence of any mood event as well as a manic or depressive event were significantly longer for the lithium 0.6–1.2 mEq/L group versus placebo and versus lithium <0.6 mEq/L, with no differences between lithium <0.6 mEq/L and placebo.Conclusions:  The results support and expand previous findings that lithium should be dosed high enough to achieve plasma levels ≥0.6 mEq/L in order to achieve an effect in the prevention of both manic and depressive recurrences of bipolar I disorder. A major limitation is that the composition of the two lithium groups was not based on randomization.
Students' engagement in technology rich classrooms and its relationship to professors' conceptions of effective teaching
Authors: Gebre Engida , Saroyan Alenoush , Bracewell Robert 
Published: December 2012

AbstractThis study examined dimensions of student engagement in technology rich classrooms and the relationship of this engagement to professors' conceptions of effective teaching. We collected questionnaire data from 332 students and analysed the data in relation to the finding of another study (Authors, forthcoming) involving 13 professors' course‐specific conceptions of effective teaching. Principal component analysis with varimax rotation revealed four dimensions of student engagement: cognitive and applied engagement, social engagement, reflective engagement and goal clarity. Subsequent multivariate and univariate analyses of variance showed that the extent of students' cognitive and applied engagement and social engagement is related significantly to professors' conceptions of effective teaching. The study has implication on design and assessment of technology‐rich learning environments and on faculty development programs involving technology use in their teaching.
Arterial and venous thrombosis in patients with monoclonal gammopathy of undetermined significance: incidence and risk factors in a cohort of 1491 patients
Authors: Za Tommaso , De Stefano Valerio , Rossi Elena , Petrucci Maria Teresa , Andriani Alessandro , Annino Luciana , Cimino Giuseppe , Caravita Tommaso , Pisani Francesco , Ciminello Angela , Torelli Fabio , Villivà Nicoletta , Bongarzoni Velia , Rago Angela , Betti Silvia , Levi Anna , Felici Stefano , Gentilini Fabiana , Calabrese Elisabetta , Leone Giuseppe ,   the Multiple Myeloma GIMEMA‐Latium Region Working Group
Published: December 2012

SummaryMonoclonal gammopathy of undetermined significance (MGUS) has been associated with an increased risk of thrombosis. We carried out a retrospective multicentre cohort study on 1491 patients with MGUS. In 49 patients (3·3%) MGUS was diagnosed after a thrombotic event. Follow‐up details for a period of at least 12 months after diagnosis of MGUS were obtained in 1238 patients who had no recent history of thrombosis (<2 years) prior to diagnosis, for a total of 7334 years. During the follow‐up, 33 of 1238 patients (2·7%) experienced thrombosis, with an incidence of 2·5 arterial events and 1·9 venous events per 1000 patient‐years. Multivariate analysis showed increased risks of arterial thrombosis in patients with cardiovascular risk factors [hazard ratio (HR) 4·92, 95%confidence interval (CI) 1·42–17·04], and of venous thrombosis in patients with a serum monoclonal (M)‐protein level >16 g/l at diagnosis (HR 3·08, 95%CI 1·01–9·36). No thrombosis was recorded in patients who developed multiple myeloma (n = 50) or other neoplastic diseases (n = 21). The incidence of arterial or venous thrombosis in patients with MGUS did not increase relative to that reported in the general population for similarly aged members. Finally, the risk of venous thrombosis did increase when the M‐protein concentration exceeded >16 g/l.
Incidence and Predictors of Atrial Septal Defect after Percutaneous Transvenous Mitral Commissurotomy – A Transesophageal Echocardiographic Study of 209 Cases
Authors: Manjunath Chollenahally Nanjappa , Panneerselvam Arunkumar , Srinivasa Kikkeri Hemanna Setty , Prabhavathi Bhat , Rangan Kapil , Dhanalakshmi Chandrasekaran , Ravindranath Khandenahally Shankarappa 
Published: December 2012

Background: The incidence of atrial septal defect (ASD) after percutaneous transvenous mitral commissurotomy (PTMC) ranges from 15.2% to 92% in small studies. Aim: To estimate the incidence of atrial septal defect (ASD) following PTMC and to determine the factors contributing to its development. Methods: We studied 209 patients with mitral stenosis (MS) undergoing PTMC. Transesophageal echocardiography (TEE) with color Doppler examination was performed to detect ASD. Results: TEE demonstrated ASD in 139 (66.5%) of 209 patients. The mean diameter of the interatrial septal defect detected by TEE was 4.47 ± 1.7 mm. The most common site of septal puncture was the inferior vena caval side of the interatrial septum followed by fossa ovalis. Color flow imaging across the defect showed left to right shunting in all the patients (100%). We examined the relationship of age, Wilkins score, left atrial volumes, the mitral valve orifice area, mitral valve gradient, and the degree of mitral and tricuspid regurgitation between the group that developed ASD and the group without ASD and found that none of these factors predicted the development of ASD. A residual ASD was seen in 11 patients (8.7%) at 6‐month follow‐up. Conclusion: Incidence of residual atrial septal defect immediately following PTMC by TEE color flow Doppler imaging is 66.5%. Surrogate markers of elevated left atrial pressures do not determine the development of atrial septal defect after PTMC. The majority of the defects close spontaneously and a residual defect is observed in 8.7% patients at 6 months.
High Incidence of Echocardiographic Abnormalities of the Interatrial Septum in Patients Undergoing Ablation for Atrial Fibrillation
Authors: Schernthaner Christiana , Danmayr Franz , Daburger Apollonia , Eichinger Jörg , Hammerer Matthias , Strohmer Bernhard 
Published: December 2012

Background: Atrial fibrosis or fatty deposition is known to increase the propensity for the development of atrial fibrillation (AF). Apart from the pulmonic veins, the interatrial septum (IAS) might play a role in the maintenance of AF. In contrast to left atrial anatomy and adjacent veins, the IAS cannot be visualized in detail with computed tomography. Thus, preprocedural transesophageal echocardiography (TEE) may provide important morphologic information beyond exclusion from atrial thrombi. Methods: The study comprised 108 consecutive patients (mean age 60 ± 11 years; 98 men). AF was paroxysmal in 91 (84%) and persistent in 17 (16%) patients. We investigated the morphological characteristics of the IAS by TEE in patients who underwent radiofrequency ablation of AF. Results: The IAS was structurally abnormal in 46 (43%) patients, showing the following echocardiograhic findings: atrial septal hypermobility or aneurysm (n = 27) associated with a patent foramen ovale (PFO) (n = 11) or with a small atrial septal defect (ASD) (n = 2), a septal flap associated with a PFO or an ASD (n = 8), and an abnormally thickened IAS (n = 12). A thrombus in the left atrial appendage was discovered in only 2 (2%) patients. Conclusions: A structurally abnormal IAS was diagnosed in nearly half of the patients undergoing ablation therapy for AF. The information obtained by TEE is mandatory to exclude left atrial thrombi prior the ablation procedure. Moreover, detailed knowledge of morphologic characteristics of the IAS facilitates an optimized and safe performance of the transseptal puncture using long sheaths with large diameters.
A Voluminous Right Atrial Myxoma Revealed by Right Side Heart Failure
Authors: Nazzi Mbarek , Belhachmi Hassan , Badidi Mehdi , Zbir Elmehdi , Mohty Dania 
Published: December 2012

Mini‐AbstractRight atrial myxoma is rare. Its clinical presentation is polymorphic. The most common presentation is heart failure, but could be pulmonary embolism or tricuspid valve obstruction. We report here, the case of a 60‐year‐old man admitted for severe heart failure. The echocardiogram showed a voluminous and floating right atrial mass, appending to the interatrial septum and protruding into the right ventricle causing severe tricuspid regurgitation. Chest computed tomography scan demonstrated multiple distal pulmonary emboli. Surgical excision and tricuspid annuloplasty were successfully performed. Histological findings were typical of a benign myxoma. At follow‐up, there was a complete regression of heart failure signs.
Species interactions constrain geographic range expansion over evolutionary time
Authors: Pigot Alex L. , Tobias Joseph A. 
Published: December 2012

AbstractWhether biotic interactions limit geographic ranges has long been controversial, and traditional analyses of static distribution patterns have made little progress towards resolving this debate. Here, we use a novel phylogenetic approach to test whether biotic interactions constrain the transition to secondary sympatry following speciation. Applying this temporal framework to a diverse clade of passerine birds (Furnariidae), we reject models of geographic range overlap limited purely by dispersal or environmental constraints, and instead show that rates of secondary sympatry are positively associated with both the phylogenetic and morphological distance between species. Thus, transition rates to sympatry increase with time since divergence and accelerate as the ecological differences between species accumulate. Taken together, these results provide strong empirical evidence that biotic interactions – and primarily ecological competition – limit species distributions across large spatial and temporal scales. They also offer phylogenetic and trait‐based metrics by which these interactions can be incorporated into ecological forecasting models.