Reflection of OH molecules from magnetic mirrors

We have reflected a Stark-decelerated beam of OH molecules under normal incidence from mirrors consisting of permanent magnets. Two different types of magnetic mirrors have been demonstrated. A long-range flat mirror made from a large disc magnet has been used to spatially focus the reflected beam in the longitudinal direction ("bunching"). A short-range curved mirror composed of an array of small cube magnets allows for transverse focusing of the reflected beam.Comment: 10 pages, 5 figure

Density and distinctiveness in early word learning:Evidence from neural network simulations

High phonological neighborhood density has been associated with both advantages and disadvantages in early word learning. High density may support the formation and fine-tuning of new word sound memories; a process termed lexical configuration (e.g. Storkel, 2004). However, new high-density words are also more likely to be misunderstood as instances of known words, and may therefore fail to trigger the learning process (e.g. Swingley & Aslin, 2007). To examine these apparently contradictory effects, we trained an autoencoder neural network on 587,954 word tokens (5497 types; including mono- and multi-syllabic words of all grammatical classes) spoken by 279 caregivers to English-speaking children aged 18 to 24 months. We then simulated a communicative development inventory administration and compared network performance to that of 2292 children aged 18 to 24 months. We argue that autoencoder performance illustrates concurrent density advantages and disadvantages, in contrast to prior behavioural and computational literature treating such effects independently. Low network error rates signal a configuration advantage for high-density words, while high network error rates signal a triggering advantage for low-density words. This interpretation is consistent with the application of autoencoders in academic research and industry, for simultaneous feature extraction (i.e. configuration) and anomaly detection (i.e. triggering). Autoencoder simulation therefore illustrates how apparently contradictory density and distinctiveness effects can emerge from a common learning mechanism

Detection of hydrogen cyanide from oral anaerobes by cavity ring down spectroscopy

Hydrogen cyanide (HCN) has been recognized as a potential biomarker for non-invasive diagnosis of Pseudomonas aeruginosa infection in the lung. However, the oral cavity is a dominant production site for exhaled HCN and this contribution can mask the HCN generated in the lung. It is thus important to understand the sources of HCN production in the oral cavity. By screening of oral anaerobes for HCN production, we observed that the genus of Porphyromonas, Prevotella and Fusobacterium generated low levels of HCN in vitro. This is the first study to show that oral anaerobes are capable of producing HCN in vitro. Further investigations were conducted on the species of P. gingivalis and we successfully detected HCN production (0.9-10.9 ppb) in the headspace of three P. gingivalis reference strains (ATCC 33277, W50 and OMG 434) and one clinical isolate. From P. gingivalis ATCC 33277 and W50, a strong correlation between HCN and CO2 concentrations (r(s) = 0.89, p <0.001) was observed, indicating that the HCN production of P. gingivalis might be connected with the bacterial metabolic activity. These results indicate that our setup could be widely applied to the screening of in vitro HCN production by both aerobic and anaerobic bacteria.Peer reviewe

Phonological development of Finnish speaking children at 3;6 and associations to previous and simultaneous lexical ability

Previous studies of Finnish children's phonological development focus mainly on children under 2;0. Earlier findings have suggested that phonological and lexical development are strongly associated at an early age. However, less is known about the longitudinal association. This study describes the phonological skills of Finnish-speaking children at 3;6 and compares them with early lexicon size at 2;0 and lexical ability at 3;6 (N = 67). The children's phonological development was measured using The Finnish Phonology Test. Lexical development was evaluated using the Finnish, long-form version of the Communicative Development Inventory at 2;0 and the Boston naming test at 3;6 At 3;6, all children mastered the vowels and diphthongs fully, and most of the children also mastered the consonants, with the exception of the phonemes/d/and/r/. Phonotactic skills had also been acquired well at this group level, although the word-medial and, especially, word-initial consonant clusters were still challenging. The percentage of phonemes correct was 95. Both paradigmatic and phonotactic skills at 3;6 were significantly associated with lexicon size at 2;0. In addition phonotactic skills correlated with naming ability at 3;6. Lexical development at 2;0 explained 21% of the variance in the phonological development at 3;6, whereas, the explaining value of simultaneous lexical skill was limited (9%). Present findings propose that associations between lexical and phonological skills weaken as phonological skills become more honed.Peer reviewe

Developmental changes in the role of different metalinguistic awareness skills in Chinese reading acquisition from preschool to third grade

Copyright @ 2014 Wei et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The present study investigated the relationship between Chinese reading skills and metalinguistic awareness skills such as phonological, morphological, and orthographic awareness for 101 Preschool, 94 Grade-1, 98 Grade-2, and 98 Grade-3 children from two primary schools in Mainland China. The aim of the study was to examine how each of these metalinguistic awareness skills would exert their influence on the success of reading in Chinese with age. The results showed that all three metalinguistic awareness skills significantly predicted reading success. It further revealed that orthographic awareness played a dominant role in the early stages of reading acquisition, and its influence decreased with age, while the opposite was true for the contribution of morphological awareness. The results were in stark contrast with studies in English, where phonological awareness is typically shown as the single most potent metalinguistic awareness factor in literacy acquisition. In order to account for the current data, a three-stage model of reading acquisition in Chinese is discussed.National Natural Science Foundation of China and Knowledge Innovation Program of the Chinese Academy of Sciences

Type 2 diabetes enhances arterial uptake of choline in atherosclerotic mice: an imaging study with positron emission tomography tracer F-18-fluoromethylcholine

Background: Diabetes is a risk factor for atherosclerosis associated with oxidative stress, inflammation and cell proliferation. The purpose of this study was to evaluate arterial choline uptake and its relationship to atherosclerotic inflammation in diabetic and non-diabetic hypercholesterolemic mice.Methods: Low-density lipoprotein-receptor deficient mice expressing only apolipoprotein B100, with or without type 2 diabetes caused by pancreatic overexpression of insulin-like growth factor II (IGF-II/LDLR−/−ApoB100/100 and LDLR−/−ApoB100/100) were studied. Distribution kinetics of choline analogue 18F-fluoromethylcholine (18F-FMCH) was assessed in vivo by positron emission tomography (PET) imaging. Then, aortic uptakes of 18F-FMCH and glucose analogue 18F-fluorodeoxyglucose (18F-FDG), were assessed ex vivo by gamma counting and autoradiography of tissue sections. The 18F-FMCH uptake in atherosclerotic plaques was further compared with macrophage infiltration and the plasma levels of cytokines and metabolic markers. Results: The aortas of all hypercholesterolemic mice showed large, macrophage-rich atherosclerotic plaques. The plaque burden and densities of macrophage subtypes were similar in diabetic and non-diabetic animals. The blood clearance of 18F-FMCH was rapid. Both the absolute 18F-FMCH uptake in the aorta and the aorta-to-blood uptake ratio were higher in diabetic than in non-diabetic mice. In autoradiography, the highest 18F-FMCH uptake co-localized with macrophage-rich atherosclerotic plaques. 18F-FMCH uptake in plaques correlated with levels of total cholesterol, insulin, C-peptide and leptin. In comparison with 18F-FDG, 18F-FMCH provided similar or higher plaque-to-background ratios in diabetic mice. Conclusions: Type 2 diabetes enhances the uptake of choline that reflects inflammation in atherosclerotic plaques in mice. PET tracer 18F-FMCH is a potential tool to study vascular inflammation associated with diabetes.</p

Methods for Minimizing the Confounding Effects of Word Length in the Analysis of Phonotactic Probability and Neighborhood Density

This is the author's accepted manuscript. The original is available at http://jslhr.pubs.asha.org/article.aspx?articleid=1781521&resultClick=3Recent research suggests that phonotactic probability (the likelihood of occurrence of a sound sequence) and neighborhood density (the number of words phonologically similar to a given word) influence spoken language processing and acquisition across the lifespan in both normal and clinical populations. The majority of research in this area has tended to focus on controlled laboratory studies rather than naturalistic data such as spontaneous speech samples or elicited probes. One difficulty in applying current measures of phonotactic probability and neighborhood density to more naturalistic samples is the significant correlation between these variables and word length. This study examines several alternative transformations of phonotactic probability and neighborhood density as a means of reducing or eliminating this correlation with word length. Computational analyses of the words in a large database and reanalysis of archival data supported the use of z scores for the analysis of phonotactic probability as a continuous variable and the use of median transformation scores for the analysis of phonotactic probability as a dichotomous variable. Neighborhood density results were less clear with the conclusion that analysis of neighborhood density as a continuous variable warrants further investigation to differentiate the utility of z scores in comparison to median transformation scores. Furthermore, balanced dichotomous coding of neighborhood density was difficult to achieve, suggesting that analysis of neighborhood density as a dichotomous variable should be approached with caution. Recommendations for future application and analyses are discussed