Phonons in potassium doped graphene: the effects of electron-phonon interactions, dimensionality and ad-atom ordering

Graphene phonons are measured as a function of electron doping via the addition of potassium adatoms. In the low doping regime, the in-plane carbon G-peak hardens and narrows with increasing doping, analogous to the trend seen in graphene doped via the field-effect. At high dopings, beyond those accessible by the field-effect, the G-peak strongly softens and broadens. This is interpreted as a dynamic, non-adiabatic renormalization of the phonon self-energy. At dopings between the light and heavily doped regimes, we find a robust inhomogeneous phase where the potassium coverage is segregated into regions of high and low density. The phonon energies, linewidths and tunability are remarkably similar for 1-4 layer graphene, but significantly different to doped bulk graphite.Comment: Accepted in Phys. Rev. B as a Rapid Communication. 5 pages, 3 figures, revised text with additional dat

Do Individual Differences And Aging Effects In The Estimation Of Geographical Slant Reflect Cognitive Or Perceptual Effects?

Several individual differences including age have been suggested to affect the perception of slant. A cross-sectional study of outdoor hill estimation (N = 106) was analyzed using individual difference measures of age, experiential knowledge, fitness, personality traits, and sex. Of particular note, it was found that for participants who reported any experiential knowledge about slant, estimates decreased (i.e., became more accurate) as conscientiousness increased, suggesting that more conscientious individuals were more deliberate about taking their experiential knowledge (rather than perception) into account. Effects of fitness were limited to those without experiential knowledge, suggesting that they, too, may be cognitive rather than perceptual. The observed effects of age, which tended to produce lower, more accurate estimates of hill slant, provide more evidence that older adults do not see hills as steeper. The main effect of age was to lower slant estimates; such effects may be due to implicit experiential knowledge acquired over a lifetime. The results indicate the impact of cognitive, rather than perceptual factors on individual differences in slant estimation

Variation in the timing of enamel formation in modern human deciduous canines

OBJECTIVES: Deciduous canines are now used increasingly in archaeological and forensic studies to establish the time of birth and as a retrospective source of trace elements incorporated into enamel before and after birth. However, data on the variability of deciduous enamel formation times are scarce. Our objectives were to use daily incremental markings to estimate daily secretion rates, the timing of prenatal, postnatal and total enamel formation and any changes in enamel coverage or prism and stria orientation that occur during enamel formation. MATERIALS AND METHODS: Longitudinal ground sections of 81 deciduous canines were studied with transmitted light microscopy. High-resolution digital images were imported from an Olympus VS-120 virtual slide scanning system into a geographic information system (ArcGIS, ESRI USA) for quantitative and statistical analyses of linear, angular and area measurements of buccal enamel. RESULTS: Daily rates of enamel secretion close to the EDJ were faster than in permanent enamel (3.23 μm/day, SD = 0.54). Prism and stria angles subtended to the EDJ both increased through crown formation. Enamel coverage was low in the cusp and cervix but maximal ∼150 days after birth. The mean prenatal enamel formation time was 118 days (range 60-150, SD, 29.2, n = 24). The overall mean postnatal enamel formation time was 319 days (range 210-420, SD 50.6, n = 67). CONCLUSIONS: Daily enamel secretion rates compared well with previous studies of deciduous enamel, however, enamel extension rates in deciduous cuspal enamel were notably lower. The variability of both prenatal and postnatal deciduous enamel formation times was greater than previously reported

A survey of the awareness, knowledge, policies and views of veterinary journal Editors-in-Chief on reporting guidelines for publication of research

Background: Wider adoption of reporting guidelines by veterinary journals could improve the quality of published veterinary research. The aims of this study were to assess the knowledge and views of veterinary Editors-in-Chief on reporting guidelines, identify the policies of their journals, and determine their information needs. Editors-in-Chief of 185 journals on the contact list for the International Association of Veterinary Editors (IAVE) were surveyed in April 2012 using an online questionnaire which contained both closed and open questions. Results: The response rate was 36.8% (68/185). Thirty-six of 68 editors (52.9%) stated they knew what a reporting guideline was before receiving the questionnaire. Editors said they had found out about reporting guidelines primarily through articles in other journals, via the Internet and through their own journal. Twenty of 57 respondents (35.1%) said their journal referred to reporting guidelines in its instructions to authors. CONSORT, REFLECT, and ARRIVE were the most frequently cited. Forty-four of 68 respondents (68.2%) believed that reporting guidelines should be adopted by all refereed veterinary journals. Qualitative analysis of the open questions revealed that lack of knowledge, fear, resistance to change, and difficulty in implementation were perceived as barriers to the adoption of reporting guidelines by journals. Editors suggested that reporting guidelines be promoted through communication and education of the veterinary community, with roles for the IAVE and universities. Many respondents believed a consensus policy on guideline implementation was needed for veterinary journals. Conclusions: Further communication and education about reporting guidelines for editors, authors and reviewers has the potential to increase their adoption by veterinary journals in the future

Automated analysis of short responses in an interactive synthetic tutoring system for introductory physics

Citation: Nakamura, C. M., Murphy, S. K., Christel, M. G., Stevens, S. M., & Zollman, D. A. (2016). Automated analysis of short responses in an interactive synthetic tutoring system for introductory physics. Physical Review Physics Education Research, 12(1), 16. doi:10.1103/PhysRevPhysEducRes.12.010122Computer-automated assessment of students' text responses to short-answer questions represents an important enabling technology for online learning environments. We have investigated the use of machine learning to train computer models capable of automatically classifying short-answer responses and assessed the results. Our investigations are part of a project to develop and test an interactive learning environment designed to help students learn introductory physics concepts. The system is designed around an interactive video tutoring interface. We have analyzed 9 with about 150 responses or less. We observe for 4 of the 9 automated assessment with interrater agreement of 70% or better with the human rater. This level of agreement may represent a baseline for practical utility in instruction and indicates that the method warrants further investigation for use in this type of application. Our results also suggest strategies that may be useful for writing activities and questions that are more appropriate for automated assessment. These strategies include building activities that have relatively few conceptually distinct ways of perceiving the physical behavior of relatively few physical objects. Further success in this direction may allow us to promote interactivity and better provide feedback in online learning systems. These capabilities could enable our system to function more like a real tutor

Monitoring riverine fish communities through eDNA metabarcoding:Determining optimal sampling strategies along an altitudinal and biodiversity gradient

Monitoring aquatic biodiversity through DNA extracted from environmental samples (eDNA) combined with high-throughput sequencing, commonly referred to as eDNA metabarcoding, is increasing in popularity within the scientific community. However, sampling strategies, laboratory protocols and analytical pipelines can influence the results of eDNA metabarcoding surveys. While the impact of laboratory protocols and analytical pipelines have been extensively studied, the importance of sampling strategies on eDNA metabarcoding surveys has not received the same attention. To avoid underestimating local biodiversity, adequate sampling strategies (i.e. sampling intensity and spatial sampling replication) need to be implemented. This study evaluated the impact of sampling strategies along an altitudinal and biodiversity gradient in the upper section of the Murrumbidgee River (Murray-Darling Basin, Australia). An eDNA metabarcoding survey was used to determine the local fish biodiversity and evaluate the influence of sampling intensity and spatial sampling replication on the biodiversity estimates. The results show that optimal eDNA sampling strategies varied between sites and indicate that river morphology, species richness and species abundance affect the optimal sampling intensity and spatial sampling replication needed to accurately assess the fish biodiversity. While the generality of the patterns will need to be confirmed through future studies, these findings provide a basis to guide future eDNA metabarcoding surveys in river systems