bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinct Mechanisms Underlie Quiescence during TwoCaenorhabditis elegansSleep-Like States
Authors: Trojanowski Nicholas F. , Nelson Matthew D. , Flavell Steven W. , Fang-Yen Christopher , Raizen David M. 
Published: October 2015

Electrophysiological recordings have enabled identification of physiologically distinct yet behaviorally similar states of mammalian sleep. In contrast, sleep in nonmammals has generally been identified behaviorally and therefore regarded as a physiologically uniform state characterized by quiescence of feeding and locomotion, reduced responsiveness, and rapid reversibility. The nematodeCaenorhabditis elegansdisplays sleep-like quiescent behavior under two conditions: developmentally timed quiescence (DTQ) occurs during larval transitions, and stress-induced quiescence (SIQ) occurs in response to exposure to cellular stressors. Behaviorally, DTQ and SIQ appear identical. Here, we use optogenetic manipulations of neuronal and muscular activity, pharmacology, and genetic perturbations to uncover circuit and molecular mechanisms of DTQ and SIQ. We find that locomotion quiescence induced by DTQ- and SIQ-associated neuropeptides occurs via their action on the nervous system, although their neuronal target(s) and/or molecular mechanisms likely differ. Feeding quiescence during DTQ results from a loss of pharyngeal muscle excitability, whereas feeding quiescence during SIQ results from a loss of excitability in the nervous system. Together these results indicate that, as in mammals, quiescence is subserved by different mechanisms during distinct sleep-like states inC. elegans.SIGNIFICANCE STATEMENTSleep behavior is characterized by cessation of feeding and locomotion, reduced responsiveness, and rapid reversibility. In mammals and birds, there are sleep states that have fundamentally different electrophysiology despite outwardly similar behavior. However, it is not clear whether behavioral sleep is a uniform state in animals in which electrophysiology is not readily possible. The nematodeCaenorhabditis elegansdisplays sleep-like behavior under two conditions: during development and after exposure to environmental stressors. Here, we show that feeding and locomotion quiescence during these two sleep-like states are produced by different mechanisms. This provides the first identification of two mechanistically distinct forms of quiescence during sleep-like states in an invertebrate.
Selective Dysregulation of Hippocampal Inhibition in the Mouse Lacking Autism Candidate GeneCNTNAP2
Authors: Jurgensen Sofia , Castillo Pablo E. 
Published: October 2015

Mutations in the human gene encoding contactin-associated protein-like 2 (CNTNAP2) have been strongly associated with autism spectrum disorders (ASDs).Cntnap2−/−mice recapitulate major features of ASD, including social impairment, reduced vocalizations, and repetitive behavior. In addition,Cntnap2−/−mice show reduced cortical neuronal synchrony and develop spontaneous seizures throughout adulthood. As suggested for other forms of ASDs, this phenotype could reflect some form of synaptic dysregulation. However, the impact of lifelong deletion ofCNTNAP2on synaptic function in the brain remains unknown. To address this issue, we have assessed excitatory and inhibitory synaptic transmission in acute hippocampal slices ofCntnap2−/−mice. We found that although excitatory transmission was mostly normal, inhibition onto CA1 pyramidal cells was altered inCntnap2−/−mice. Specifically, putative perisomatic, but not dendritic, evoked IPSCs were significantly reduced in these mice. Whereas both inhibitory short-term plasticity and miniature IPSC frequency and amplitude were normal inCntnap2−/−mice, we found an unexpected increase in the frequency of spontaneous, action potential-driven IPSCs. Altered hippocampal inhibition could account for the behavioral phenotypeCntnap2−/−mice present later in life. Overall, our findings thatCntnap2deletion selectively impairs perisomatic hippocampal inhibition while sparing excitation provide additional support for synaptic dysfunction as a common mechanism underlying ASDs.SIGNIFICANCE STATEMENTThe gene encoding contactin-associated protein-like 2 (CNTNAP2) stands out as one the first genes to have both rare and common mutations strongly associated with ASDs. WhereasCntnap2−/−mice appear to recapitulate core behavioral endophenotypes (e.g., social impairment, language deficits, and repetitive behavior), the cellular and circuit bases of this phenotype remain poorly understood. Here, we report that synaptic inhibition specifically onto the perisomatic compartment of CA1 pyramidal cells is impaired, whereas dendritic inhibition and excitatory transmission remain basically unchanged inCntnap2−/−mice. These findings provide additional support to the notion that disruption of inhibition, in particular perisomatic inhibition onto principal cells, could play a critical role in ASDs.
Hemispheric Asymmetries in Striatal Reward Responses Relate to Approach–Avoidance Learning and Encoding of Positive–Negative Prediction Errors in Dopaminergic Midbrain Regions
Authors: Aberg Kristoffer Carl , Doell Kimberly C. , Schwartz Sophie 
Published: October 2015

Some individuals are better at learning about rewarding situations, whereas others are inclined to avoid punishments (i.e., enhanced approach or avoidance learning, respectively). In reinforcement learning, action values are increased when outcomes are better than predicted (positive prediction errors [PEs]) and decreased for worse than predicted outcomes (negative PEs). Because actions with high and low values are approached and avoided, respectively, individual differences in the neural encoding of PEs may influence the balance between approach–avoidance learning. Recent correlational approaches also indicate that biases in approach–avoidance learning involve hemispheric asymmetries in dopamine function. However, the computational and neural mechanisms underpinning such learning biases remain unknown. Here we assessed hemispheric reward asymmetry in striatal activity in 34 human participants who performed a task involving rewards and punishments. We show that the relative difference in reward response between hemispheres relates to individual biases in approach–avoidance learning. Moreover, using a computational modeling approach, we demonstrate that better encoding of positive (vs negative) PEs in dopaminergic midbrain regions is associated with better approach (vs avoidance) learning, specifically in participants with larger reward responses in the left (vs right) ventral striatum. Thus, individual dispositions or traits may be determined by neural processes acting to constrain learning about specific aspects of the world.SIGNIFICANCE STATEMENTIndividuals differ in how they behave toward rewards or punishments. Here, we demonstrate that functional hemispheric asymmetries measured in dopaminergic reward regions dictate whether someone will learn to choose rewarding options or instead avoid punishing outcomes. We also show that hemispheric reward asymmetries involve a differential neural encoding of signals controlling approach and avoidance learning. We thus provide experimental evidence for a mechanism that accounts for individual differences in approach and avoidance learning. Disabling mental illnesses have previously been associated with hemispheric asymmetries in dopamine function and extreme biases in approach–avoidance behavior. By showing that these observations implicate biased learning processes, the present study may offer important insights into the development and maintenance of some psychiatric disorders.
Distinctive Representation of Mispredicted and Unpredicted Prediction Errors in Human Electroencephalography
Authors: Hsu Yi-Fang , Le Bars Solene , Hämäläinen Jarmo A. , Waszak Florian 
Published: October 2015

The predictive coding model of perception proposes that neuronal responses are modulated by the amount of sensory input that the internal prediction cannot account for (i.e., prediction error). However, there is little consensus on what constitutes nonpredicted stimuli. Conceptually, whereas mispredicted stimuli may induce both prediction error generated by prediction that is not perceived and prediction error generated by sensory input that is not anticipated, unpredicted stimuli involves no top-down, only bottom-up, propagation of information in the system. Here, we examined the possibility that the processing of mispredicted and unpredicted stimuli are dissociable at the neurophysiological level using human electroencephalography. We presented participants with sets of five tones in which the frequency of the fifth tones was predicted, mispredicted, or unpredicted. Participants were required to press a key when they detected a softer fifth tone to maintain their attention. We found that mispredicted and unpredicted stimuli are associated with different amount of cortical activity, probably reflecting differences in prediction error. Moreover, relative to predicted stimuli, the mispredicted prediction error manifested as neuronal enhancement and the unpredicted prediction error manifested as neuronal attenuation on the N1 event-related potential component. These results highlight the importance of differentiating between the two nonpredicted stimuli in theoretical work on predictive coding.SIGNIFICANCE STATEMENTThe current research seeks to dissociate the neurophysiological processing of two types of “nonpredicted” stimuli that have long been considered interchangeable: mispredicted and unpredicted stimuli. We found that mispredicted stimuli, which violate predictions, and unpredicted stimuli, which lack predictions, are represented distinctively in the brain. The results will influence the design of experiments on the predictive coding mechanism, in which the contrast between predicted and “nonpredicted” conditions should be specifically defined to reveal the prediction error proper. This is of general interest because it concerns the logic of research investigating all levels of processing (including perceptual, motor, and cognitive processing) in many neuroscientific domains.
CULTIVATING PRE-SERVICE TEACHERS’ CLASSROOM MANAGEMENT SKILLS THROUGH TEACHING PRACTICUM: A REFLECTIVE PRACTICE
Authors: Ragawanti Debora Tri 
Published: October 2015

Classroom management is commonly believed to be the key to the success of an instruction. Many student teachers, however, might find it very challenging to handle their classrooms. It is, therefore, necessary to advance their professional practice in the context of a real classroom such as through teaching practicum and reflective practice. This study is aimed at identifying classroom management problems of student-teachers as revealed in their reflective journal entries and to demonstrate how such journal can help them develop their classroom management skills. The participants were 10 student-teachers of the English Department, Satya Wacana Christian University, Salatiga, Central Java, who underwent their teaching practicum at SMP 2 Salatiga. Through the participants’ journals, it was found that the problems lie in managing critical moments, activity, techniques, grouping and seating, authority, tools, and working with people. Further in this study, both pre- and in-service tertiary teachers, curriculum designers, and policy makers will be taken to deeply examine how reflective practice can help cultivate the pre-service’s classroom management skills and to consider the implication for pedagogical practices and innovations in curriculum development.
LECTURERS’ AND STUDENTS’ BELIEFS IN CODE-SWITCHING: A MALAYSIAN POLYTECHNIC CONTEXT
Authors: Mokhtar Mazlin Mohamed 
Published: October 2015

This research is to discover whether lecturers’ beliefs coincide with their practices in their daily teaching. The focus will be on the belief in the use of code-switching in the classroom. At the same time, it is also worthwhile to indicate whether there are differences in the beliefs between the lecturers and the students. For that purpose three lecturers from an engineering department of a polytechnic in a northern region as well as the students in the classrooms were chosen to participate in this research. The methods designed include classroom observations, questionnaires for both the lecturers and students, and interviews with the lecturers after the classroom observation. The findings showed that the lecturers mostly used reiteration and message qualification functions when code-switching. They believed that it was intended mainly to enhance their students’ understanding and to save their time from lengthy explanation whenever the students are in doubt. This was agreeable by most students as they believed that code-switching could help them understand the lessons better. Some recommendations are made based on the findings and analysis of the results, expecting that it would further improve the teaching of Mathematics, Science and technical subjects in the Malaysian polytechnics.
CONCEPTIONS AND PRACTICES OF ASSESSMENT: A CASE OF TEACHERS REPRESENTING IMPROVEMENT CONCEPTION
Authors: Azis Astuti 
Published: October 2015

Despite numerous quantitative studies on teachers’ conceptions and practices of assessment, little research exists regarding the unique assessment environment of Indonesia. This study uses both quantitative and qualitative data to examine how Indonesian junior high school teachers understand assessment and how their conceptions of assessment relate to their assessment practices. This mixed methods study adopted a participant selection model in which quantitative data was analysed to select participants for the qualitative phase. Participants of this study believed that the purpose of assessment was to improve teaching and learning and also to demonstrate the accountability of students and school. They tended to disagree with the view that assessment is irrelevant. Further analysis of the data revealed that teachers’ conceptions of assessment were conflicted. They were keen to use assessment practices to improve their classroom teaching, but felt that the state-wide examination policy requirements constrained their efforts. This suggests that government, policy makers, and curriculum developers must work to build a strong synergy among themselves in order to share consistent goals with teachers. If cultural expectations of school assessment and government policy were aligned, Indonesian teachers may be better able to resolve conflict between their beliefs and assessment practices.
Oral Squamous Cell Carcinoma Mimicking Peri‐Implantitis
Authors: Chainani‐Wu Nita , Chang Crystal , Sim Chelsia , Wu Timothy C. , Cox Darren , Sirjani Davud , Silverman Sol 
Published: October 2015

Introduction: Peri‐implantitis is inflammation and alveolar bone loss around a dental implant. Published case reports have described squamous cell carcinoma (SCC) development around dental implants.Case Presentation: A 60‐year‐old female presented with two small fistulas on the alveolar ridge of missing tooth #18. The mucosa around the fistulas appeared normal otherwise, with no hyperplasia, erythema, or keratotic changes. The patient had a 14‐year history of recurrent erythroleukoplakia (with microscopic dysplasia) on the left tongue that had been managed by surgical removal (scalpel and carbon dioxide laser), biopsies, and close follow‐up. She had no other medical conditions. She reported that she had an implant placed to replace tooth #18 4 years ago that had been removed without flap reflection, curettage, or biopsy 1 year previously as a result of peri‐implantitis. Periapical radiographs showed that the peri‐implant radiolucency in the region of tooth #18 was unchanged in dimensions from the time of implant removal 1 year ago. Curettage and biopsy of the area were performed and showed the presence of a well‐differentiated SCC.Conclusions: This is a case of peri‐implant SCC development in a patient at high risk for oral SCC. The carcinoma was present within the alveolar defect in the area of a failed implant that had been removed 1 year previously. The overlying surface mucosa did not show the clinical changes typically seen in carcinoma. This case and others demonstrate the importance of periodic oral and radiographic examination after implant placement. Although rare, neoplasia must be considered in the evaluation of peri‐implant pathology.
Discriminación en Servicios de Educación EBR. Valoración Crítica de las Resoluciones del INDECOPI desde una Perspectiva Práctico-Realista
Authors: Gonzales Linares Emily Alejandra 
Published: October 2015

<p>El presente artículo deriva del trabajo de investigación del mismo autor (Gonzales Linares, 2014), que realiza una crítica valorativa sobre las resoluciones de primera y segunda instancia emitidas por el Indecopi entre los años 2006 y 2013. Respecto de denuncias de parte y procedimientos de oficio derivados de casos de discriminación en la prestación de servicios educativos, por motivo de discapacidad, religión, orientación sexual y condiciones económicas. Ello a partir de criterios valorativos preestablecidos y principalmente vinculados a la actuación de la prueba y la imposición de la sanción. <br /><br />Desarrollado el análisis, se obtuvo como resultado que el Indecopi no maneja adecuadamente los recursos procedimentales que le asisten, ni cumple con el requisito de motivar sus resoluciones. El propósito del presente artículo es ofrecer una perspectiva práctico – realista que sirva de instrumento para nutrir futuros debates sobre el tema.<br /><br />This paper is based on research that conducted an evaluative review of the resolutions of first and second instance of Indecopi, issued regarding complaints and ex officio procedures as a result of discrimination in the provision of educational services based on disability, religion, sexual orientation and economic conditions. Two criteria, the evidence presented and the sanction imposed were used.</p><p><br />As a result, the research found that Indecopi mishandle their procedural resources and did not meet the requirement to base their decisions. The purpose of this article is to provide a practical and realistic view of the subject and to contribute to future discussions on the subject.</p>
Use of a Direct Anatomic Post in a Flared Root Canal: A Three-year Follow-up
Authors: Gomes GM , Monte-Alto RV , Santos GO , Fai CK , Loguercio AD , Gomes OMM , Gomes JC , Reis A 
Published: October 2015

SUMMARY
The following case report describes the three-year follow-up after rehabilitation of a flared root canal using a direct anatomic post (a resin composite combined with a prefabricated glass fiber post) associated with metal-free ceramic restoration. The report presents the clinical protocol for the fabrication of the posts, which provide an intimate fit to the remaining root and mechanical properties similar to those of the dental structure. These posts serve as an alternative to conventional metal cores.
The Effect of Resin-modified Glass-ionomer Cement Base and Bulk-fill Resin Composite on Cuspal Deformation
Authors: Nguyen KV , Wong RH , Palamara J , Burrow MF 
Published: October 2015

SUMMARY
Objectives: This study investigated cuspal deformation in teeth restored with different types of adhesive materials with and without a base.
Methods: Mesio-occluso-distal slot cavities of moderately large dimension were prepared on extracted maxillary premolars (n=24). Teeth were assigned to one of four groups and restored with either a sonic-activated bulk-fill resin composite (RC) (SonicFill), or a conventional nanohybrid RC (Herculite Ultra). The base materials used were a flowable nanofilled RC (Premise Flowable) and a high-viscosity resin-modified glass-ionomer cement (RMGIC) (Riva Light-Cure HV). Cuspal deflection was measured with two direct current differential transformers, each contacting a buccal and palatal cusp. Cuspal movements were recorded during and after restoration placement. Data for the buccal and palatal cusp deflections were combined to give the net cuspal deflection.
Results: Data varied widely. All teeth experienced net inward cuspal movement. No statistically significant differences in cuspal deflection were found among the four test groups.
Conclusions: The use of a flowable RC or an RMGIC in closed-laminate restorations produced the same degree of cuspal movement as restorations filled with only a conventional nanohybrid or bulk-fill RC.
Effect of Tooth-structure Thickness on Light Attenuation and Depth of Cure
Authors: Hamlin NJ , Bailey C , Motyka NC , Vandewalle KS 
Published: October 2015

SUMMARY
Newer bulk-fill composites claim a greater depth of cure than conventional resin-based composites. To facilitate complete curing, the manufacturer of SonicFill (Kerr) recommends curing from the occlusal, as well as the buccal and lingual, surfaces of the tooth. The purpose of this study was to quantify the degree of curing light attenuation as it passes through natural tooth structure, and how this attenuation affects the depth of cure of different posterior resin composites. Ten noncarious extracted mandibular third molars were sectioned to produce 5-mm-thick pieces of buccal tooth structure. Sanding 0.5-mm increments from the flattened surface produced 4.5-, 4.0-, 3.5-, 3.0-, 2.5-, 2.0-, and finally 1.5-mm-thick sections. A Bluephase G2 (Ivoclar) curing light with an 8-mm-diameter light guide set on high for 20 seconds was used for measurement of irradiance as it passed through different thicknesses of tooth structure and air. The average irradiance (mW/cm2) was measured with a MARC-RC Resin Calibrator with a 4-mm-diameter sensor (BlueLight Analytics). To measure depth of cure of a conventional hybrid composite (Herculite Ultra; Kerr) vs a bulk-fill hybrid composite (SonicFill) through varying thicknesses of tooth structure, composites were cured in a 4-mm-diameter × 10.25-mm-long split mold according to International Organization for Standardization 4049. A mean and standard deviation was determined per group. Data were analyzed with a one-way analysis of variance (ANOVA)/Tukey test and two-way ANOVA/Tukey test (α=0.05). One-way ANOVA/Tukey found a significant decrease in irradiance based on thickness of tooth structure or distance through air (p&lt;0.001). Two-way ANOVA/Tukey found a significant decrease in depth of cure based on thickness of tooth structure (p&lt;0.001) and on composite type (p&lt;0.001) with no significant interaction (p=0.623). SonicFill had a significantly greater depth of cure than Herculite Ultra.
Comparison of the Effects of In-office Bleaching Times on Whitening and Tooth Sensitivity: A Single Blind, Randomized Clinical Trial
Authors: Kose C , Calixto AL , Bauer JRO , Reis A , Loguercio AD 
Published: October 2015

SUMMARY
Objectives: The objective of the present study was to compare the bleaching efficacy (BE) and tooth sensitivity (TS) of in-office bleaching applied under different time protocols.
Methods and Materials: Fifty-three patients were randomly distributed into three groups: the bleaching agent was applied in one (1×15), two (2×15), or three (3×15) 15-minute applications. The labial surfaces of the anterior teeth were bleached using a 35% hydrogen peroxide gel. Two bleaching sessions with a one-week interval between were performed. The shade evaluation was performed with a visual shade guide and spectrophotometer before and 30 days after bleaching. Participants recorded TS with a five-point verbal scale. Color change was analyzed by one-way analysis of variance and Tukey tests. The absolute risk of TS and TS intensity were evaluated by the Fisher exact and Friedman/Kruskal-Wallis tests, respectively (α= 0.05).
Results: Significant whitening was observed in all groups, with statistically lower BE for the 1×15 group (p&lt;0.05). The absolute risk of TS (95% confidence interval) was lower for the 1×15 group than for the other groups (p&lt;0.05). The TS intensity of the 3×15 group was statistically higher than that associated with the other protocols (p&lt;0.05).
Conclusions: A single 15-minute application produced less TS but reduced BE. The protocol with 2×15 produced a degree of BE similar to that of the 3×15 group, but with reduced overall TS intensity.