bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative study of ribosomal proteins: linkage between amino acid distribution and ribosomal assembly
Authors: Lott Brittany Burton , Wang Yongmei , Nakazato Takuya 
Published: October 2013

Abstract

Background
Assembly of the ribosome from its protein and RNA constituents must occur quickly and efficiently in order to synthesize the proteins necessary for all cellular activity. Since the early 1960’s, certain characteristics of possible assembly pathways have been elucidated, yet the mechanisms that govern the precise recognition events remain unclear.
We utilize a comparative analysis to investigate the amino acid composition of ribosomal proteins (r-proteins) with respect to their role in the assembly process. We compared small subunit (30S) r-protein sequences to those of other housekeeping proteins from 560 bacterial species and searched for correlations between r-protein amino acid content and factors such as assembly binding order, environmental growth temperature, protein size, and contact with ribosomal RNA (rRNA) in the 30S complex.

Results
We find r-proteins have a significantly high percent of positive residues, which are highly represented at rRNA contact sites. An inverse correlation between the percent of positive residues and r-protein size was identified and is mainly due to the content of Lysine residues, rather than Arginine. Nearly all r-proteins carry a net positive charge, but no statistical correlation between the net charge and the binding order was detected. Thermophilic (high-temperature) r-proteins contain increased Arginine, Isoleucine, and Tyrosine, and decreased Serine and Threonine compared to mesophilic (lower-temperature), reflecting a known distinction between thermophiles and mesophiles, possibly to account for protein thermostability. However, this difference in amino acid content does not extend to rRNA contact sites, as the proportions of thermophilic and mesophilic contact residues are not significantly different.

Conclusions
Given the significantly higher level of positively charged residues in r-proteins and at contact sites, we conclude that ribosome assembly relies heavily on an electrostatic component of interaction. However, the binding order of r-proteins in assembly does not appear to depend on these electrostatics interactions. Additionally, because thermophiles and mesophiles exhibit significantly different amino acid compositions in their sequences but not in the identities of contact sites, we conclude that this electrostatic component of interaction is insensitive to temperature and is not the determining factor differentiating the temperature sensitivity of ribosome assembly.
The nucleus accumbens: a target for deep brain stimulation in resistant major depressive disorder
Authors: Nauczyciel Cecilia , Robic Suzanne , Dondaine Thibaut , Verin Marc , Robert Gabriel , Drapier Dominique , Naudet Florian , Millet Bruno 
Published: October 2013

Abstract

Objective
This review aimed to investigate the therapeutic potential of Deep Brain Stimulation (DBS) for treating resistant Major Depressive Disorder (MDD). We explored the role of Nucleus accumbens (Nac) as a target for treatment.

Method
We made a systematic review of all studies examining the mechanisms of action of high frequency brain stimulation and the pathophysiology of MDD. We also reported all the studies exploring the therapeutic potential of DBS in MDD.

Results
As a central relay-structure, the Nac seems to play a central role in MDD symptomatology. We investigated its role as a primary target for DBS in depressed patients. Anatomically the Nac is at the centre of the interactions between dopaminergic, serotoninergic and glutamatergic systems. Functionally, the Nac is involved in both normal and abnormal reward processes and in anhedonia and loss of motivation. Due to its central location between the emotional system, the cognitive system and motor control system, the Nac seems to have a central role in mood and feeling regulation.

Conclusion
According to encouraging recent studies, DBS seems to be a promising technique in resistant MDD treatment.
Anti-citrullinated peptide autoantibodies, human leukocyte antigen shared epitope and risk of future rheumatoid arthritis: a nested case–control study
Authors: Arkema Elizabeth V , Goldstein Barbara L , Robinson William , Sokolove Jeremy , Wagner Catriona A , Malspeis Susan , Rosner Bernard , Grodstein Francine , Karlson Elizabeth W , Costenbader Karen H 
Published: October 2013

Abstract
Introduction
The aim of this study was to characterize anti-citrullinated peptide antibody (ACPA) serostatus in pre-clinical rheumatoid arthritis (RA) with and without Human Leukocyte Antigen-Shared Epitope (HLA-SE) alleles.

Methods
We identified 192 women in the Nurses’ Health Study cohorts with blood samples obtained 4 months to 17 years prior to medical record-confirmed RA diagnosis. Three controls were selected matched on age, cohort, menopausal status and post-menopausal hormone use. Reactivities to 18 ACPAs were measured using a custom BioPlex platform. We used conditional logistic regression to calculate the relative risk (RR) of RA for any ACPA-positive and peptide-specific ACPA-positive and examined RRs by time between blood draw and RA onset. Measures of multiplicative and additive interaction between any ACPA-positive and HLA-SE were calculated.

Results
All ACPAs by peptide groups were significantly associated with RA risk, RRs ranged from 4.7 to 11.7. The association between ACPA and RA varied over time with the strongest association in those with blood draw less than 5 years before onset (RR 17.0 [95% CI 5.8 to 53.7]) and no association 10 or more years prior to onset (RR 1.4 [95% CI 0.5 to 4.3]). Individuals with both HLA-SE and any ACPA-positive had the highest risk of RA. HLA-SE-positive RA cases showed reactivity to more ACPA types than HLA-SE negative (χ2 test for trend, P = 0.01).

Conclusions
There is increasing ACPA reactivity up to 10 years before RA onset with the strongest association within 5 years of RA onset. The magnitude of the response to ACPAs, in combination with the presence of HLA-SE, is most important for identifying those individuals with the highest risk of RA.
The Chelation-controlled Mukaiyama Aldol Reaction of Chiral α- and β-Alkoxy Aldehydes
Authors: Roiban Gheorghe-Doru , Ilie Adriana , Reetz Manfred T 
Published: October 2013

Abstract
The concept of treating chiral α- and β-alkoxy aldehydes with bicoordinate Lewis acids such as TiCl4, SnCl4, or MgBr2 followed by the addition of carbon nucleophiles for achieving chelation control with 1,2- and 1,3-asymmetric induction, respectively, was introduced three decades ago and has since evolved into a general method. In the case of enol silanes, the chelation-controlled Mukaiyama aldol reaction is involved, which has been used in recent natural products syntheses.
Broadband in School: Impact on Student Performance
Authors: Belo Rodrigo , Ferreira Pedro , Telang Rahul 
Published: October 2013

This paper examines the effects of providing broadband to schools on students' performance. We use a rich panel of data on broadband use and students' grades from all middle schools in Portugal. Employing a first-differences specification to control for school-specific unobserved effects and instrumenting the quality of broadband to account for unobserved time-varying effects, we show that high levels of broadband use in schools were detrimental for grades on the ninth-grade national exams in Portugal. For the average broadband use in schools, grades reduced 0.78 of a standard deviation from 2005 to 2009. We also show that broadband has a negative impact on exam scores regardless of gender, subject, or school quality and that the way schools allow students to use the Internet affects their performance. In particular, students in schools that block access to websites such as YouTube perform relatively better. Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2013.1770 . This paper was accepted by Lorin Hitt, information systems.
Foreign Language Anxiety: Past and Future
Authors: Luo Han 
Published: October 2013

Abstract
This paper gives a comprehensive review of studies on foreign language anxiety. Foreign
language anxiety has been recognized in the past few decades as a situation-specific
emotional reaction that potentially impedes foreign language learning. Research has shown
that foreign language anxiety is not only prevalent among foreign language learners, but
also has various negative effects on foreign language learning. In order to help learners cope
with this problem, researchers have identified a large number of sources of foreign language
anxiety, which generally fall into four major categories, namely, the classroom environment,
learner characteristics, the target language, and the foreign language learning process itself.
Researchers have also investigated quite a number of factors associated with foreign language
anxiety (including categorical background variables and quantitative learner variables) and
have produced mixed results. Based on a thorough review of foreign language anxiety, the
paper concludes with recommendations for future studies on foreign language anxiety.
A Study of the Impacts of Participating in
the “CCTV CUP” English Public Speaking
Contest on the Contestants
Authors: Wang Jieqing 
Published: October 2013

Abstract
Up to now there still lacks relevant study on what role participating in English public speaking
contests plays in cultivating students’ English public speaking ability and the instruction of
this course. The “CCTV CUP” English public speaking contest is one of the most important
contests of this field. Despite a few studies on the “CCTV CUP” in the literature, none of them
has focused on the contestants’ perspective. This paper first attempts to describe the
“CCTV CUP” English public speaking contest from the perspective of sociocultural theory and social
realism. Then it takes 7 final contestants’ “reactions to participating in the contest” for analysis,
focusing on what impacts participating in this contest brought on them. The results show
that participating in the “CCTV CUP” English public speaking contest not only deepened the
contestants’ understandings about English public speaking, but brought significant harvests
at ability training, and the increase of life experience and wisdom. At last, it gives relevant
suggestions on the instruction of English public speaking course.
An ERP Study on Metaphor Comprehension
in the Bilingual Brain
Authors: Chen Hongjun , Peng Xiaoshuang , Zhao Yanli 
Published: October 2013

Abstract
A good number of neurophysiological studies have been conducted to explore the neural
mechanisms of metaphor processing, but few have taken the bilingual phenomenon into
consideration. The current study, by using event related potentials (ERPs), investigated the
neural mechanism employed by Chinese native speakers whose second language is English
in comprehending Chinese and English metaphors. Amplitudes of the N400 ERP component
(350-600 ms) were more negative for English metaphors compared with Chinese literal
sentences, English literal sentences and Chinese metaphors. In addition, both hemispheres
were more activated in processing English metaphors than other conditions. These findings
provide electrophysiological evidence for a different mechanism used by Chinese – English
bilinguals to comprehend Chinese and English metaphors.
Constructing elliptic curve isogenies in quantum subexponential time
Authors: Childs Andrew , Jao David , Soukharev Vladimir 
Published: October 2013

Abstract.
Given two ordinary elliptic curves over a finite field
having the same cardinality and endomorphism ring, it is known that
the curves admit a nonzero isogeny between them, but finding such an
isogeny is believed to be computationally difficult. The fastest
known classical algorithm takes exponential time, and prior to our
work no faster quantum algorithm was known. Recently, public-key
cryptosystems based on the presumed hardness of this problem have
been proposed as candidates for post-quantum cryptography. In this
paper, we give a new subexponential-time quantum algorithm for
constructing nonzero isogenies between two such elliptic curves,
assuming the Generalized Riemann Hypothesis (but with no other
assumptions). Our algorithm is based on a reduction to a hidden
shift problem, and represents the first nontrivial application of
Kuperberg's quantum algorithm for finding hidden shifts. This
result suggests that isogeny-based cryptosystems may be
uncompetitive with more mainstream quantum-resistant cryptosystems
such as lattice-based cryptosystems. As part of this work, we also
present the first classical algorithm for evaluating isogenies
having provably subexponential running time in the cardinality
of the base field under GRH.
Ferrous bisglycinate 25 mg iron is as effective as ferrous sulfate 50 mg iron in the prophylaxis of iron deficiency and anemia during pregnancy in a randomized trial
Authors: Milman Nils , Jønsson Lisbeth , Dyre Pernille , Pedersen Palle Lyngsie , Larsen Lise Grupe 
Published: October 2013

Abstract

Objective: To compare the effects of oral ferrous bisglycinate 25 mg iron/day vs. ferrous sulfate 50 mg iron/day in the prevention of iron deficiency (ID) and iron deficiency anemia (IDA) in pregnant women. Design: Randomized, double-blind, intention-to-treat study. Setting: Antenatal care clinic. Sample: 80 healthy ethnic Danish pregnant women.

Methods: Women were allocated to ferrous bisglycinate 25 mg elemental iron (Aminojern®) (n=40) or ferrous sulfate 50 mg elemental iron (n=40) from 15 to 19 weeks of gestation to delivery. Hematological status (hemoglobin, red blood cell indices) and iron status (plasma iron, plasma transferrin, plasma transferrin saturation, plasma ferritin) were measured at 15–19 weeks (baseline), 27–28 weeks and 36–37 weeks of gestation. Main outcome measures: Occurrence of ID (ferritin <15 μg/L) and IDA (ferritin <12 μg/L and hemoglobin <110 g/L).

Results: At inclusion, there were no significant differences between the bisglycinate and sulfate group concerning hematological status and iron status. The frequencies of ID and IDA were low and not significantly different in the two iron groups. The frequency of gastrointestinal complaints was lower in the bisglycinate than in the sulfate group (P=0.001). Newborns weight was slightly higher in the bisglycinate vs. the sulfate group (3601±517 g vs. 3395±426 g, P=0.09).

Conclusions: In the prevention of ID and IDA, ferrous bisglycinate was not inferior to ferrous sulfate. Ferrous bisglycinate in a low dose of 25 mg iron/day appears to be adequate to prevent IDA in more than 95% of Danish women during pregnancy and postpartum.
The Impact of Dopamine on Aggression: An [18F]-FDOPA PET Study in Healthy Males
Authors: Schlüter Thorben , Winz Oliver , Henkel Karsten , Prinz Susanne , Rademacher Lena , Schmaljohann Jörn , Dautzenberg Kai , Cumming Paul , Kumakura Yoshitaka , Rex Steffen , Mottaghy Felix M. , Gründer Gerhard , Vernaleken Ingo 
Published: October 2013

Cerebral dopamine (DA) transmission is thought to be an important modulator for the development and occurrence of aggressive behavior. However, the link between aggression and DA transmission in humans has not been investigated using molecular imaging and standardized behavioral tasks. We investigated aggression as a function of DA transmission in a group of (N= 21) healthy male volunteers undergoing 6-[18F]-fluoro-l-DOPA (FDOPA)-positron emission tomography (PET) and a modified version of the Point Subtraction Aggression Paradigm (PSAP). This task measures aggressive behavior during a monetary reward-related paradigm, where a putative adversary habitually tries to cheat. The participant can react in three ways (i.e., money substraction of the putative opponent [aggressive punishment], pressing a defense button, or continuing his money-making behavior). FDOPA-PET was analyzed using a steady-state model yielding estimates of the DA-synthesis capacity (K), the turnover of tracer DA formed in living brain (kloss), and the tracer distribution volume (Vd), which is an index of DA storage capacity.Significant negative correlations between PSAP aggressive responses and the DA-synthesis capacity were present in several regions, most prominently in the midbrain (r= −0.640;p= 0.002). Lower degrees of aggressive responses were associated with higher DA storage capacity in the striatum and midbrain. Additionally, there was a significant positive correlation between the investment into monetary incentive responses on the PSAP and DA-synthesis capacity, notably in the midbrain (r= +0.618,p= 0.003). The results suggest that individuals with low DA transmission capacity are more vulnerable to reactive/impulsive aggression in response to provocation.
The Sociability of History in French Grand Opera: A Historical Materialist Perspective
Authors: Mondelli Peter 
Published: October 2013

Abstract
French grand opera relied heavily on historical sources for its stories, settings, and characters. This article reexamines why representations of the past captivated Parisian audiences. For these spectators, history was not just a purely factual discourse about what happened centuries ago, it was also a social phenomenon. As such, grand opera's appropriation of historical subjects depended on new social spaces formed by new patterns in text production and consumption. When these spaces first emerged, historical grand opera became socially feasible, and as they were transformed, the genre began to wane. Focusing on Auber's La Muette de Portici, this article reconsiders the emergence of historical grand opera in terms of such material conditions of possibility. It then outlines how new material conditions in the middle decades of the nineteenth century reshaped attitudes toward operatic history, drawing on the historical materialist philosophy of Walter Benjamin to clarify the effects of these social and technological changes.
The Effect of Flapless Surgery on Implant Survival and Marginal Bone Level: A Systematic Review and Meta‐Analysis
Authors: Lin Guo‐Hao , Chan Hsun‐Liang , Bashutski Jill D. , Oh Tae‐Ju , Wang Hom‐Lay 
Published: October 2013

Background: The clinical outcomes of implants placed using the flapless approach have not yet been systematically investigated. Hence, the present systematic review and meta‐analysis aims to study the effect of the flapless technique on implant survival rates (SRs) and marginal bone levels (MBLs) compared with the conventional flap approach.Methods: An electronic search of five databases (from 1990 to March 2013), including PubMed, Ovid (MEDLINE), EMBASE, Web of Science, and Cochrane Central, and a hand search of peer‐reviewed journals for relevant articles were performed. Human clinical trials with data on comparison of SR and changes in MBL between the flapless and conventional flap procedures, with at least five implants in each study group and a follow‐up period of at least 6 months, were included.Results: Twelve studies, including seven randomized controlled trials (RCTs), one cohort study, one pilot study, and three retrospective case‐controlled trials (CCTs), were included. The SR of each study was recorded, weighted mean difference (WMD) and confidence interval (CI) were calculated, and meta‐analyses were performed for changes in MBL. The average SR is 97.0% (range, 90% to 100%) for the flapless procedure and 98.6% (range, 91.67% to 100%) for the flap procedure. Meta‐analysis for the comparison of SR among selected studies presented a similar outcome (risk ratio = 0.99, 95% CI = 0.97 to 1.01, P = 0.30) for both interventions. Mean differences of MBL were retrieved from five RCTs and two retrospective CCTs and subsequently pooled into meta‐analyses; however, none of the comparisons showed statistical significance. For RCTs, the WMD was 0.07, with a 95% CI of −0.05 to 0.20 (P = 0.26). For retrospective CCTs, the WMD was 0.23, with a 95% CI of −0.58 to 1.05 (P = 0.58). For the combined analysis, the WMD was 0.03, with a 95% CI of −0.11 to 0.18 (P = 0.67). The comparison of SR presented a low to moderate heterogeneity, but MBL presented a considerable heterogeneity among studies.Conclusion: This systematic review revealed that the SRs and radiographic marginal bone loss of flapless intervention were comparable with the flap surgery approach.
The Effect of Surface Roughness on Repair Bond Strength of Light-Curing Composite Resin to Polymer Composite Substrate
Authors: Kallio Timo T. , Tezvergil-Mutluay Arzu , Lassila Lippo V.J. , Vallittu Pekka K. 
Published: October 2013

Objective:
The purpose of this study was to analyze the shear bond strength of a new composite resin to polymer-based composite substrates using various surface roughnesses and two kinds of polymer matrices.

Materials and methods:
Particulate filler composite resin with cross-linked polymer matrix and fiber-reinforced composite with semi-interpenetrating polymer matrix were used as bonding substrates after being ground to different roughnesses. Substrates were aged in water for one week before bonding to new resin composites. Twelve specimens in the substrate groups were ground with grinding papers of four grits; 320, 800, 1200 and 2400.

Results:
Corresponding values of surface roughness (Ra) varied from 0.09 to 0.40 for the particulate filler composite resin and 0.07 to 0.96 for the fiber-reinforced composite resin. Characteristic shear bond strength between the new resin and particulate filler composite resin was highest (27.8 MPa) with the roughest surface (Weibull modulus: 2.085). Fiber-reinforced composite showed the highest bond strength (20.8 MPa) with the smoothest surface (Weibull modulus: 4.713).

Conclusions:
We concluded that surface roughness did not increase the bonding of new resin to the substrate of IPN based fiber-reinforced composite, whereas the roughness contributed to bonding the new resin to the particulate filler composite resin with a cross-linked polymer matrix.
Clinical Performance of a New Biomimetic Double Network Material
Authors: Dirxen Christine , Blunck Uwe , Preissner Saskia 
Published: October 2013

Background:The development of ceramics during the last years was overwhelming. However, the focus was laid on the hardness and the strength of the restorative materials, resulting in high antagonistic tooth wear. This is critical for patients with bruxism.Objectives:The purpose of this study was to evaluate the clinical performance of the new double hybrid material for non-invasive treatment approaches.Material and Methods:The new approach of the material tested, was to modify ceramics to create a biomimetic material that has similar physical properties like dentin and enamel and is still as strong as conventional ceramics.Results:The produced crowns had a thickness ranging from 0.5 to 1.5 mm. To evaluate the clinical performance and durability of the crowns, the patient was examined half a year later. The crowns were still intact and soft tissues appeared healthy and this was achieved without any loss of tooth structure.Conclusions:The material can be milled to thin layers, but is still strong enough to prevent cracks which are stopped by the interpenetrating polymer within the network. Depending on the clinical situation, minimally- up to non-invasive restorations can be milled.Clinical Relevance:Dentistry aims in preservation of tooth structure. Patients suffering from loss of tooth structure (dental erosion, Amelogenesis imperfecta) or even young patients could benefit from minimally-invasive crowns. Due to a Vickers hardness between dentin and enamel, antagonistic tooth wear is very low. This might be interesting for treating patients with bruxism.