bluuebunny/crossref_metadata_2025_split huggingface dataset:
Moderator effects of working memory on the stability of ADHD symptoms by dopamine receptor gene polymorphisms during development
Authors: Trampush Joey W. , Jacobs Michelle M. , Hurd Yasmin L. , Newcorn Jeffrey H. , Halperin Jeffrey M. 
Published: January 2014

AbstractWe tested the hypothesis that dopamine D1 and D2 receptor gene (DRD1 and DRD2, respectively) polymorphisms and the development of working memory skills can interact to influence symptom change over 10 years in children with attention‐deficit/hyperactivity disorder (ADHD). Specifically, we examined whether improvements in working memory maintenance and manipulation from childhood to early adulthood predicted the reduction of ADHD symptoms as a function of allelic variation in DRD1 and DRD2. Participants were 76 7–11‐year‐old children with ADHD who were genotyped and prospectively followed for almost 10 years. ADHD symptoms were rated using the Attention Problems scale on the Child Behavior Checklist, and verbal working memory maintenance and manipulation, measured by Digit Span forward and backward, respectively, were assessed at baseline and follow‐up. After correction for multiple testing, improvements in working memory manipulation, not maintenance, predicted reduction of symptomatology over development and was moderated by major allele homozygosity in two DRD1 polymorphisms (rs4532 and rs265978) previously linked with variation in D1 receptor expression. Depending on genetic background, developmental factors including age‐dependent variation in DRD1 penetrance may facilitate the link between improvements in higher‐order working memory and the remission of symptoms in individuals with childhood‐diagnosed ADHD. Furthermore, the current findings suggest that DRD1 might contribute minimally to the emergence of symptoms and cognitive difficulties associated with ADHD in childhood, but may act as a modifier gene of these clinical features and outcome during later development for those with ADHD.
Arithmetic facts storage deficit: the hypersensitivity‐to‐interference in memory hypothesis
Authors: De Visscher Alice , Noël Marie‐Pascale 
Published: January 2014

AbstractDyscalculia, or mathematics learning disorders, is currently known to be heterogeneous (Wilson & Dehaene, ). While various profiles of dyscalculia coexist, a general and persistent hallmark of this math learning disability is the difficulty in memorizing arithmetic facts (Geary, Hoard & Hamson, ; Jordan & Montani, ; Slade & Russel, ). Arithmetic facts are simple arithmetic problems that are solved by direct retrieval from memory. Recently, De Visscher and Noël () showed hypersensitivity‐to‐interference in memory in an adult suffering from a specific deficit of arithmetic facts storage. According to the authors, arithmetic facts share many features. The overlapping of these features between arithmetic facts may provoke interference. Consequently, learners who are hypersensitive‐to‐interference could have considerable difficulties in storing arithmetic facts. The present study aims at testing this new hypothesis on fourth‐grade children who are learning multiplication tables. Among 101 children that were assessed, 23 low arithmetic facts learners were selected because of their low score in arithmetic facts fluency (controlling for processing speed). Twenty‐three control children were selected, matched for classroom, gender, and age. In addition to a subtest of global reasoning, these participants were given a multiplication production task and a memorization task of low‐ and high‐interference associations. The results show that children with low arithmetic fluencies experience hypersensitivity‐to‐interference in memory compared with children with typical arithmetic fluencies.
Breastfeeding and trajectories of children's cognitive development
Authors: Huang Jin , Peters Kristen E. , Vaughn Michael G. , Witko Christopher 
Published: January 2014

AbstractThe aim of this study was to examine the association of breastfeeding practices with the growth trajectories of children's cognitive development. We used data from the Child Development Supplement (CDS) of the Panel Study of Income Dynamics (PSID) with variables on presence and duration of breastfeeding and standardized test scores obtained during three different panel waves (N = 2681). After adjusting for covariates we found that breastfed children had higher test scores but that breastfed and non‐breastfed children had similar growth trajectories in test scores over time. The results indicate that breastfeeding has an important association with test scores, and that subsequent schooling and other experiences during adolescence do not eliminate the breastfeeding gap that appears in very early childhood.
Why do spatial abilities predict mathematical performance?
Authors: Tosto Maria Grazia , Hanscombe Ken B. , Haworth Claire M.A. , Davis Oliver S.P. , Petrill Stephen A. , Dale Philip S. , Malykh Sergey , Plomin Robert , Kovas Yulia 
Published: January 2014

AbstractSpatial ability predicts performance in mathematics and eventual expertise in science, technology and engineering. Spatial skills have also been shown to rely on neuronal networks partially shared with mathematics. Understanding the nature of this association can inform educational practices and intervention for mathematical underperformance. Using data on two aspects of spatial ability and three domains of mathematical ability from 4174 pairs of 12‐year‐old twins, we examined the relative genetic and environmental contributions to variation in spatial ability and to its relationship with different aspects of mathematics. Environmental effects explained most of the variation in spatial ability (~70%) and in mathematical ability (~60%) at this age, and the effects were the same for boys and girls. Genetic factors explained about 60% of the observed relationship between spatial ability and mathematics, with a substantial portion of the relationship explained by common environmental influences (26% and 14% by shared and non‐shared environments respectively). These findings call for further research aimed at identifying specific environmental mediators of the spatial–mathematics relationship.Research highlights

About a third of the variation in spatial ability at age 12 is explained by genetic factors; a little less than half of the variation in mathematics at this age is genetic.

We find no sex differences in the genetic and environmental influences (either in magnitude or type) on mathematical and spatial variation at age 12.

The observed overlap between spatial ability and mathematics is substantial (r > .40). Approximately 60% of this overlap is explained by common genetic effects, with 40% of the overlap due to environmental experience.
Minocycline attenuates HIV‐1 infection and suppresses chronic immune activation in humanized NOD/LtsZ‐scidIL‐2Rγnull mice
Authors: Singh Maneesh , Singh Pratibha , Vaira Dolores , Amand Mathieu , Rahmouni Souad , Moutschen Michel 
Published: January 2014

SummaryMore than a quarter of a century of research has established chronic immune activation and dysfunctional T cells as central features of chronic HIV infection and subsequent immunodeficiency. Consequently, the search for a new immunomodulatory therapy that could reduce immune activation and improve T‐cell function has been increased. However, the lack of small animal models for in vivo HIV study has hampered progress. In the current study, we have investigated a model of cord blood haematopoietic progenitor cells (CB‐HPCs) ‐transplanted humanized NOD/LtsZ‐scidIL‐2Rγnull mice in which progression of HIV infection is associated with widespread chronic immune activation and inflammation. Indeed, HIV infection in humanized NSG mice caused up‐regulation of several T‐cell immune activation markers such as CD38, HLA‐DR, CD69 and co‐receptor CCR5. T‐cell exhaustion markers PD‐1 and CTLA‐4 were found to be significantly up‐regulated on T cells. Moreover, increased plasmatic levels of lipopolysaccharide, sCD14 and interleukin‐10 were also observed in infected mice. Treatment with minocycline resulted in a significant decrease of expression of cellular and plasma immune activation markers, inhibition of HIV replication and improved T‐cell counts in HIV‐infected humanized NSG mice. The study demonstrates that minocycline could be an effective, low‐cost adjunctive treatment to regulate chronic immune activation and replication of HIV.
Pulse Electric Current–Aided Reactive Sintering of High‐Purity Zr3Al3C5
Authors: Zhou Jie , Qiu Fagui , Shen Lu , Li Fangzhi , Xue Jianming , Barsoum Michel W. , Huang Qing 
Published: January 2014

Herein, we report on the in situ reactive synthesis and simultaneous densification of a high‐purity ternary Zr3Al3C5 phase via pulse electric current sintering (PECS) of Zr/Al/graphite powder mixtures with a molar ratio of 3:3.2:4.8. The phases and microstructure evolution in the 580°C–1800°C temperature range were characterized by X‐ray diffraction, real‐time sintering curves, and a scanning electron microscope equipped with an energy dispersive spectroscope. An additive‐free, fully dense Zr3Al3C5 compound was obtained at 1800°C using a load corresponding to a stress of 35 MPa for 20 min. The final product was comprised of 96.61 wt% Zr3Al3C5, 3.14 wt% ZrC, and 0.25 wt% Zr2Al3C4; the relative density was 97%.
A Novel Approach to Improve Properties of BiFeO3 Nanomultiferroics
Authors: Arya Ghanshyam , Kotnala Ravinder K. , Negi Nainjeet Singh 
Published: January 2014

In this study we report the synthesis of Bi1−xInxFe1−yTiyO3 (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.05) nanoparticles by a simple cost effective solution combustion method. Pure BFO samples shows distorted rhombohedral perovskite structure with space group R3c which is also supported by Fourier transform infrared spectra study. The codoping of In and Ti at A–B sites of BFO (BIFTO) partially distorts the crystal structure, increases the lattice strain, reduces the average particle size (14 nm), and increases the Fe3+/Fe2+ ratio which significantly affect the observed results. The saturation magnetization increases significantly upon codoping (4.60 emu/gm) by about 12 times than that of pure BFO (0.4 emu/gm). The improved ferromagnetic properties upon codoping is further manifestated in large value of linear magnetoelectric coupling coefficient (4.8 mV/cmOe) which further provides an indirect evidence for the collapse of space modulated spin structure. The activation energy increases with codoping (0.68 eV), although less than 1 eV which indicates that the conduction is still dominated by charged defects.
Spectroscopic Studies of Nanopowder and Nanoceramics La2Hf2O7:Pr Scintillator
Authors: Trojan‐Piegza Joanna , Gierlotka Stanislaw , Zych Eugeniusz , Lojkowski Witold 
Published: January 2014

Sintered nanoceramics of Pr‐doped lanthanum hafnate, La2Hf2O7:Pr, were prepared by means of a high‐pressure sintering technique using nanopowders made by Pechini method. Structure, morphology, and spectroscopic properties of the ceramics compared to the starting powder are presented and discussed. Emission and excitation spectra recorded at room temperature as well as at 7 K using synchrotron radiation are presented together with results of luminescence kinetics measurements. In ceramics, at 7 K, the Pr3+ luminescence from 3P0 (blue‐green, green, and red region) and 1D2 (red) levels is accompanied by a broad‐band emission located in the 380–530 nm range of wavelengths, whereas powders gives only the Pr3+‐related luminescence. Depending on the excitation wavelength, the broad‐band emission maximum moves between 430 and 470 nm indicating superposition of at least two components. In sintered nanoceramics, the lifetimes of Pr3+ emissions from 3P0 and 1D2 levels were by 10%–20% shorter compared to the powder. The existence of different luminescence centers was proved by the selective emission decays examination. The fast 5d → 4f luminescence of Pr3+ was not observed from either of the two types of La2Hf2O7:Pr materials.
Microstructure of a Ce0.1Zr0.9O2–MgAl2O4 Ceramic Matrix Composite for Use in Dentistry
Authors: Krumeich Frank , Wörle Micheal , Nesper Reinhard , Höland Marlies , Ritzberger Christian , Rothbrust Frank , Chevalier Jerome , Rheinberger Volker M. , Höland Wolfram 
Published: January 2014

A ceramic matrix composite (CMC) with the chemical composition of 90 wt% Ce0.1Zr0.9O2 and 10 wt% MgAl2O4 was produced by filter‐pressing, drying, and heat treatment at 1400°C. The internal microstructure was studied using the transmission electron microscopy (TEM) technique combined with energy‐dispersive X‐ray spectroscopy. Because of the intended use in dentistry, the surfaces of the as‐fired and of the mechanically treated samples were characterized by atomic force microscopy (AFM) and X‐ray diffraction (XRD Rietveld analysis). This study revealed that Ce0.1Zr0.9O2 and MgAl2O4 spinel are the only crystalline phases present in the CMC material. Nevertheless, apart from the tetragonal Ce0.1Zr0.9O2, its monoclinic phase was identified as a third crystal phase in the as‐fired sample with an amount of ~2.5 wt%, at the surface of polished (5.3 wt%) and roughened (8 wt%) specimens. In sum, the microstructure of the CMC material is homogeneous and can be modified by mechanical surface treatment leading to a partial transformation of the tetragonal phase of the Ce0.1Zr0.9O2 component into the monoclinic one. This partial transformation is also visible in AFM, with occurrence of transformation bands. The mechanism yield in surface compressive stress can be determined according to the Williamson and Hall method. The authors conclude that the absence of microcrack formation during polishing or roughening confirms the high flaw tolerance of such a CMC material.
Cystathionine γ‐lyase, an Enzyme Related to the Reverse Transsulfuration Pathway, is Functional in Leishmania spp.
Authors: Giordana Lucila , Mantilla Brian Suárez , Santana Marianela , Silber Ariel M. , Nowicki Cristina 
Published: January 2014

AbstractLeishmania parasites seem capable of producing cysteine by de novo biosynthesis, similarly to bacteria, some pathogenic protists, and plants. In Leishmania spp., cysteine synthase (CS) and cystathionine β‐synthase (CBS) are expected to participate in this metabolic process. Moreover, the reverse transsulfuration pathway (RTP) is also predicted to be operative in this trypanosomatid because CBS also catalyzes the condensation of serine with homocysteine, and a gene encoding a putative cystathionine γ‐lyase (CGL) is present in all the sequenced genomes. Our results show that indeed, Leishmania major CGL is able to rescue the wild‐type phenotype of a Saccharomyces cerevisiae CGL‐null mutant and is susceptible to inhibition by an irreversible CGL inhibitor, DL‐propargylglycine (PAG). In Leishmania promastigotes, CGL and CS are cytosolic enzymes. The coexistence of de novo synthesis with the RTP is extremely rare in most living organisms; however, despite this potentially high redundancy in cysteine production, PAG arrests the proliferation of L. major promastigotes with an IC50 of approximately 65 μM. These findings raise new questions regarding the biological role of CGL in these pathogens and indicate the need for understanding the molecular mechanism of PAG action in vivo to identify the potential targets affected by this drug.
Influence of surface free energy of denture base and liner materials onCandida albicansbiofilms
Authors: da Silva Wander J. , Leal Cristiane Maria B. , Viu Flávia C. , Gonçalves Letícia M. , Barbosa Célia Marisa R. , Del Bel Cury Altair A. 
Published: January 2014

AbstractAimThis study aimed to evaluate the influence of surface free energy (SFE) of denture base and liner materials onCandida albicansbiofilm development.MethodsDiscs were fabricated using poly(methyl methacrylate) acrylic resin and poly(ethyl methacrylate) denture liner, according to the manufacturers' instructions. ForSFEtest, discs were pellicle‐coated with saliva alone, saliva + blood plasma, or blood plasma alone.Candida albicansbiofilms were allowed to form on pellicle‐coated discs for 48 h. Biofilms were evaluated for cell counts, metabolic activity, and structural characteristics at adhesion phase (after 1.5 h of development) and at biofilm maturity (after 48 h of development). Data were analyzed byanovaand Tukey tests using a significance level of 5%.ResultsSaliva + blood plasma pellicles had a higherSFEcompared to pellicles of saliva or blood plasma alone (P < 0.001). Differences inSFEby pellicle‐coating did not affect the cell counts, metabolic activity, or structure at the adhesion phase (P > 0.05). In contrast, the presence of blood plasma resulted in higher cell counts, biovolume, and thickness of mature biofilms on both materials (P < 0.001).ConclusionsIncreases inSFEfrom pellicle‐coating leads to robust matureC. albicansbiofilms on both denture materials.
Effect of configuration factor on gap formation in hybrid composite resin, low‐shrinkage composite resin and resin‐modified glass ionomer
Authors: Boroujeni Parvin M. , Mousavinasab Sayyed M. , Hasanli Elham 
Published: January 2014

AbstractAimPolymerization shrinkage is one of the important factors in creation of gap between dental structure and composite resin restorations. The aim of this study was to evaluate the effect of configuration factor (C‐factor) on gap formation in a hybrid composite resin, a low shrinkage composite resin and a resin modified glass ionomer restorative material.MethodsCylindrical dentin cavities with 5.0 mm diameter and three different depths (1.0, 2.0 and 3.0 mm) were prepared on the occlusal surface of 99 human molars and the cavities assigned into three groups (each of 33). Each group contained three subgroups depend on the different depths and then cavities restored using resin modified glass ionomer (Fuji II LC Improved) and two type composite resins (Filtek P90 and Filtek Z250). Then the restorations were cut into two sections in a mesiodistal direction in the middle of restorations. Gaps were measured on mesial, distal and pulpal floor of the cavities, using a stereomicroscope.ResultsData analyses using Kruskal–Wallist and Mann–Whitney tests. Increasing C‐factor from 1.8 to 3.4 had no effect on the gap formation in two type composite resins, but Fuji II LC Improved showed significant effect of increasing C‐factor on gap formation. Taken together, when C‐factor increased from 1.8 up to 3.4 had no significant effect on gap formation in two tested resin composites. Although, Filtek P90 restorations showed smaller gap formation in cavities walls compared to Filtek Z250 restorations.ConclusionsHigh C‐factor values generated the largest gap formation. Silorane‐based composite was more efficient for cavity sealing than methacrylate‐based composites and resin modified glass ionomer.
Rereading the Kripkean Intuition on Reference
Authors: Flanagan Brian 
Published: January 2014

AbstractSaul Kripke's thought experiments on the reference of proper names target the theory that the properties which identify a term's referent are the subject of an implicit agreement. Recently, survey versions of the experiments have been thought to show that intuitions about reference are culturally contingent. Proposing a revisionary interpretation, this article argues, first, that Kripke's Cicero/Feynman experiment reveals that every name user knows enough to be capable of identifying the same individual as the name's most informed users. Second, the article shows that Kripke's presentation of the Gödel/Jonah experiment is ambiguous with respect to the properties attributed to the referent. Disambiguated, the experiment fails to reveal that name users may be mistaken in every unique property they attribute. Since the experiment's ambiguity is replicated in survey presentations, cross‐cultural variation in survey response fails to show that intuitions about reference are culturally contingent.
Secretion and functional display of fusion proteins through the curli biogenesis pathway
Authors: Van Gerven Nani , Goyal Parveen , Vandenbussche Guy , De Kerpel Maia , Jonckheere Wim , De Greve Henri , Remaut Han 
Published: January 2014

SummaryCurli are functional amyloids expressed as fibres on the surface of Enterobacteriaceae. Contrary to the protein misfolding events associated with pathogenic amyloidosis, curli are the result of a dedicated biosynthetic pathway. A specialized transporter in the outer membrane, CsgG, operates in conjunction with the two accessory proteins CsgE and CsgF to secrete curlin subunits to the extracellular surface, where they nucleate into cross‐beta strand fibres. Here we investigate the substrate tolerance of the CsgG transporter and the capability of heterologous sequences to be built into curli fibres. Non‐native polypeptides ranging up to at least 260 residues were exported when fused to the curli subunit CsgA. Secretion efficiency depended on the folding properties of the passenger sequences, with substrates exceeding an approximately 2 nm transverse diameter blocking passage through the transport channel. Secretion of smaller passengers was compatible with prior DsbA‐mediated disulphide bridge formation in the fusion partner, indicating that CsgG is capable of translocating non‐linear polypeptide stretches. Using fusions we further demonstrate the exported or secreted heterologous passenger proteins can attain their native, active fold, establishing curli biogenesis pathway as a platform for the secretion and surface display of small heterologous proteins.
Psychotherapy role expectations and experiences – Discrepancy and therapeutic alliance among patients with substance use disorders
Authors: Frankl My , Philips Björn , Wennberg Peter 
Published: January 2014

ObjectivesThe main aim of the study was to examine how the discrepancy between role expectations prior to psychotherapy and experiences of ongoing psychotherapy related to therapeutic alliance. We hypothesized that a similarity between patient role expectations and experiences would be associated with a stronger alliance. The study also examined whether different dimensions of psychotherapy role expectations predicted retention in psychotherapy.DesignA naturalistic study design was used with data collected prior to therapy and during the first 6 months of therapy.MethodPatients with substance use disorders completed the Psychotherapy Expectation Questionnaire‐short version (PEX‐S) at the time of therapy assessment. A subsample of these patients (n = 41; n = 24 in individual therapy and n = 17 in group therapy) provided data from therapy including psychotherapy experiences (also measured with PEX‐S) and therapeutic alliance, measured with Working Alliance Questionnaire‐short version.ResultsFor patients in group therapy, discrepancy between role expectations and experiences correlated negatively with alliance. Expectations prior to psychotherapy characterized by defensiveness correlated negatively with therapy retention.ConclusionThe finding that disconfirmation of patients' role expectations in group therapy were associated with weaker therapeutic alliance highlights the importance of discussing psychotherapy expectations at an early stage in treatment. Expectations characterized by defensiveness predicted worse retention in psychotherapy, which indicates that the PEX‐S can be helpful in detecting patients at risk for dropout.Practitioner points

In targeting a patient's role expectancies prior to treatment, possible discrepancies between patient and therapist are made visible and possible to examine.

Clarifying the patient's role expectations and the therapist's rationale might be a first step towards establishing a strong working alliance.

Surveying the patient's defensiveness tendencies at the beginning of therapy offers a chance to discuss possible fears and other obstacles concerning therapy.

Discrepancy between the patient's role expectations prior to treatment and their actual experiences of psychotherapy render valuable information that can be of use in the therapy process.