bluuebunny/crossref_metadata_2025 huggingface dataset:
Latent class instrumental variables: a clinical and biostatistical perspective
Authors: Baker Stuart G. , Kramer Barnett S. , Lindeman Karen S.
Published: August 2015

In some two‐arm randomized trials, some participants receive the treatment assigned to the other arm as a result of technical problems, refusal of a treatment invitation, or a choice of treatment in an encouragement design. In some before‐and‐after studies, the availability of a new treatment changes from one time period to this next. Under assumptions that are often reasonable, the latent class instrumental variable (IV) method estimates the effect of treatment received in the aforementioned scenarios involving all‐or‐none compliance and all‐or‐none availability. Key aspects are four initial latent classes (sometimes called principal strata) based on treatment received if in each randomization group or time period, the exclusion restriction assumption (in which randomization group or time period is an instrumental variable), the monotonicity assumption (which drops an implausible latent class from the analysis), and the estimated effect of receiving treatment in one latent class (sometimes called efficacy, the local average treatment effect, or the complier average causal effect). Since its independent formulations in the biostatistics and econometrics literatures, the latent class IV method (which has no well‐established name) has gained increasing popularity. We review the latent class IV method from a clinical and biostatistical perspective, focusing on underlying assumptions, methodological extensions, and applications in our fields of obstetrics and cancer research. Copyright © 2015 John Wiley & Sons, Ltd.
170 Jahre Großherzoglich Badische Staats‐Eisenbahn. Vier Brücken – ein Standort
Authors: Boeyng Ulrich
Published: August 2015

Vier verschiedene Eisenbahnbrücken führten seit 1844 und die jüngste bis zum heutigen Tag über die Kinzig in Offenburg. Sie alle zeugen von der Geschichte der Großherzoglich Badischen Staats‐Eisenbahn, an ihnen lässt sich der technische Fortschritt im Brückenbau darstellen, und zugleich spielten alle eine wichtige Rolle im Schicksal der Stadt.

170 years of Grand Ducal‐Baden State Railways – Four bridges – one Place. Four different railway bridges crossed since 1844 up to the present day the Kinzig River in Offenburg, Germany. They bear witness to the history of the Grand Ducal‐Baden State Railways, they represent technological progress in bridge building and at the same time they played an important role in the fate of the city.
Bayesian wombling: finding rapid change in spatial maps
Authors: Gelfand Alan E. , Banerjee Sudipto
Published: August 2015

In spatial analysis, typically we specify a region of interest and consider a spatial surface over the region. It is often of interest to ascertain where the surface is changing rapidly. Identifying locations or curves where there is rapid change is referred to as wombling. The surface may arise continuously over the region or discretely, in which case values are provided for a collection of areal units. In either setting, algorithmic strategies are available to attempt to identify so‐called wombling boundaries. In this study, the surfaces of interest are all assumed to be random, realizations of a Gaussian process in the continuous case, of a Markov random field in the discrete case. With specifications given as stochastic models, we discuss Bayesian approaches to implement desired boundary analysis. We refer to this as Bayesian wombling and show how fully model‐based inference can be carried out, including assessment of uncertainty. The approach for the continuous case is more theoretically demanding (expected with an uncountable set of locations) but yields elegant distribution theory. The discrete case is more straightforward. Each case is illustrated with a brief example. WIREs Comput Stat 2015, 7:307–315. doi: 10.1002/wics.1360

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Bayesian Methods and Theory

Data: Types and Structure > Image and Spatial Data

Statistical and Graphical Methods of Data Analysis > Markov Chain Monte Carlo (MCMC)
Reduction of l-phenylalanine in protein hydrolysates using l-phenylalanine ammonia-lyase from Rhodosporidium toruloides
Authors: Castañeda María Teresita , Adachi Osao , Hours Roque Alberto
Published: August 2015

l-Phenylalanine ammonia-lyase (PAL, EC 4.3.1.25) from Rhodosporidium toruloides was utilized to remove l-phenylalanine (l-Phe) from different commercial protein hydrolysates. A casein acid hydrolysate (CAH, l-Phe ~2.28 %) was employed as a model substrate. t-Cinnamic acid resulting from deamination of l-Phe was extracted, analyzed at λ = 290 nm, and used for PAL activity determination. Optimum reaction conditions, optimized using successive Doehlert design, were 35 mg mL−1 of CAH and 800 mU mL−1 of PAL, while temperature and pH were 42 °C and 8.7, respectively. Reaction kinetics of PAL with CAH was determined under optimized conditions. Then, removal of l-Phe from CAH was tested. Results showed that more than 92 % of initial l-Phe was eliminated. Similar results were obtained with other protein hydrolysates. These findings demonstrate that PAL is a useful biocatalyst for l-Phe removal from protein hydrolysates, which can be evaluated as potential ingredients in foodstuffs for PKU patients.
4-Methoxy-α-PVP: in silico prediction, metabolic stability, and metabolite identification by human hepatocyte incubation and high-resolution mass spectrometry
Authors: Ellefsen Kayla N. , Wohlfarth Ariane , Swortwood Madeleine J. , Diao Xingxing , Concheiro Marta , Huestis Marilyn A.
Published: August 2015

Novel psychoactive substances are continuously developed to circumvent legislative and regulatory efforts. A new synthetic cathinone, 4-methoxy-α-PVP, was identified for the first time in illegal products; however, the metabolism of this compound is not known. Complete metabolic profiles are needed for these novel psychoactive substances to enable identification of their intake and to link adverse effects to the causative agent. This study assessed 4-methoxy-α-PVP metabolic stability with human liver microsomes (HLMs) and identified its metabolites after HLM and hepatocyte incubations followed by high-resolution mass spectrometry (HRMS). A Thermo QExactive high-resolution mass spectrometer (HRMS) was used with full scan data-dependent mass spectrometry, with (1) and without (2) an inclusion list of predicted metabolite, and with full scan and all-ion fragmentation (3) to identify potential unexpected metabolites. In silico predictions were performed and compared to in vitro results. Scans were thoroughly mined with different data processing algorithms using WebMetabase (Molecular Discovery). 4-Methoxy-α-PVP exhibited a long half-life of 79.7 min in HLM, with an intrinsic clearance of 8.7 µL min−1 mg−1. In addition, this compound is predicted to be a low-clearance drug with an estimated human hepatic clearance of 8.2 mL min−1 kg−1. Eleven 4-methoxy-α-PVP metabolites were identified, generated by O-demethylation, hydroxylation, oxidation, ketone reduction, N-dealkylation, and glucuronidation. The most dominant metabolite in HLM and human hepatocyte samples was 4-hydroxy-α-PVP, also predicted as the #1 in silico metabolite, and is suggested to be a suitable analytical target in addition to the parent compound.
Older Age and Leg Pain Are Good Predictors of Pain and Disability Outcomes in 2710 Patients who Receive Lumbar Fusion
Authors: Cook Chad E. , Frempong-Boadu Anthony K. , Radcliff Kristen , Karikari Isaac , Isaacs Robert
Published: August 2015

Background

Identifying appropriate candidates for lumbar spine fusion is a challenging and controversial topic. The purpose of this study was to identify baseline characteristics related to poor/favorable outcomes at 1 year for a patient who received lumbar spine fusion.

Questions/Purposes

The aims of this study were to describe baseline characteristics of those who received lumbar surgery and to identify baseline characteristics from a spine repository that were related to poor and favorable pain and disability outcomes for patient who received lumbar fusion (with or without decompression), who were followed up for 1 full year and discriminate predictor variables that were either or in contrast to prognostic variables reported in the literature.

Methods

This study analyzed data from 2710 patients who underwent lumbar spine fusion. All patient data was part of a multicenter, multi-national spine repository. Ten relatively commonly captured data variables were used as predictors for the study. Univariate/multivariate logistic regression analyses were run against outcome variables of pain/disability.

Results

Multiple univariate findings were associated with pain/disability outcomes at 1 year including age, previous surgical history, baseline disability, baseline pain, baseline quality of life scores, and leg pain greater than back pain. Notably significant multivariate findings for both pain and disability include older age, previous surgical history, and baseline mental summary scores, disability, and pain.

Conclusion

Leg pain greater than back pain and older age may yield promising value when predicting positive outcomes. Other significant findings may yield less value since these findings are similar to those that are considered to be prognostic regardless of intervention type.
Risk factors for complications and readmission after operative fixation of pediatric femur fractures
Authors: Momaya Amit , Baker Dustin , Gilbert Shawn , Ponce Brent
Published: August 2015

Purpose

Operative fixation of pediatric femur fractures with intramedullary implants has grown in popularity in recent decades. However, risk factors for short-term adverse events and readmission have not been well studied.

Methods

Pediatric patients who underwent intramedullary nailing of a femur fracture between 2012 and 2013 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Risk factors for any adverse event (AAE) and readmission after intramedullary nailing were evaluated using univariate and multivariate analysis.

Results

A total of 522 pediatric patients who underwent intramedullary nailing of the femur during the study period were identified. The mean age of this patient cohort was 10.2 ± 3.8 years. Review of the cases revealed that 18 (3.4 %) patients had AAE and that 20 (3.8 %) patients were readmitted, of whom 13 (2.5 %) underwent a reoperation. Independent risk factors for AAE were a cardiac comorbidity [odds ratio (OR) 12.7, 95 % confidence interval (CI) 1.5, 103.7], open fracture (OR 10.2, 95 % CI 1.4, 74.4), and prolonged operative time (OR 17.5, 95 % CI 6.1, 50.5). Independent risk factors for readmission were a central nervous system disorder (OR 4.5, 95 % CI 1.3, 16.2) and a seizure disorder (OR 4.9, 95 % CI 1.0, 23.5).

Conclusions

The results of the multivariate analysis suggest that cardiac comorbidities, open fractures, and prolonged operative time increase the risk for AAE and that central nervous system disorders and seizure disorders may increase the risk for readmission. Surgeons should be aware of these risk factors and counsel the families of pediatric patients who undergo intramedullary nailing of femur fractures.
Dual processing theory and expertsʼ reasoning: exploring thinking on national multiple-choice questions
Authors: Durning Steven J. , Dong Ting , Artino Anthony R. , Van der Vleuten Cees , Holmboe Eric , Schuwirth Lambert
Published: August 2015

Background An ongoing debate exists in the medical education literature regarding the potential benefits of pattern recognition (non-analytic reasoning), actively comparing and contrasting diagnostic options (analytic reasoning) or using a combination approach. Studies have not, however, explicitly explored faculty’s thought processes while tackling clinical problems through the lens of dual process theory to inform this debate. Further, these thought processes have not been studied in relation to the difficulty of the task or other potential mediating influences such as personal factors and fatigue, which could also be influenced by personal factors such as sleep deprivation. We therefore sought to determine which reasoning process(es) were used with answering clinically oriented multiple-choice questions (MCQs) and if these processes differed based on the dual process theory characteristics: accuracy, reading time and answering time as well as psychometrically determined item difficulty and sleep deprivation.

Methods We performed a think-aloud procedure to explore faculty’s thought processes while taking these MCQs, coding think-aloud data based on reasoning process (analytic, nonanalytic, guessing or combination of processes) as well as word count, number of stated concepts, reading time, answering time, and accuracy. We also included questions regarding amount of work in the recent past. We then conducted statistical analyses to examine the associations between these measures such as correlations between frequencies of reasoning processes and item accuracy and difficulty. We also observed the total frequencies of different reasoning processes in the situations of getting answers correctly and incorrectly.
Experiments on standing waves in a rectangular tank with a corrugated bed
Authors: Weidman Patrick D. , Herczynski Andrzej , Yu Jie , Howard Louis N.
Published: August 2015

An experimental investigation of resonant standing water waves in a rectangular tank with a corrugated bottom is reported. The study was stimulated by the theory of Howard & Yu (J. Fluid Mech., vol. 593, 2007, pp. 209–234) predicting the existence of normal modes that can be significantly affected by Bragg reflection/scattering. As a result, the amplitude of the standing waves (normal modes) varies exponentially along the entire length of the tank, or from the centre out in each direction, depending on the phase of the corrugations at the tank endwalls. Experiments were conducted in a 5 m tank fitted with a sinusoidal bottom with one adjustable endwall. Waves were excited by small-amplitude sinusoidal horizontal movement of the tank using an electrical motor drive system. Simultaneous time-series data of standing oscillations were recorded at well-separated positions along the tank to measure the growth in amplitude. Waveforms over a section of the tank were filmed through the transparent acrylic walls. Except for very shallow depths and near the tank endwalls, the experimental measurements of resonant frequencies, mean wavelengths, free-surface waveforms and amplitude growth are found in essential agreement with the Bragg resonant normal mode theory.
Dynamic behaviour of buoyant high viscosity droplets rising in a quiescent liquid
Authors: Albert C. , Kromer J. , Robertson A. M. , Bothe D.
Published: August 2015

The present paper initiates a systematic computational analysis of the rise dynamics of high viscosity droplets in a viscous ambient liquid. This represents a relevant intermediate case between free rigid particles and bubbles since their shape adjusts to outer forces while almost no inner circulation is present. As a prototype system, we study corn oil droplets rising in pure water with diameters ranging from 0.5 to 16 mm. Since we are interested in the droplet dynamics from the viewpoint of a bifurcation scenario with increasingly complex droplet behaviour, we perform fully three-dimensional numerical simulations, employing the in-house volume-of-fluid (VOF)-code FS3D. The smallest droplets (0.5–2 mm) rise in steady vertical paths, where for the smallest droplet (0.5 mm) the flow field, as well as the terminal velocity, can be described by the Taylor and Acrivos approximate solution, despite the Reynolds number being well above one. Larger droplets (3.2 mm) rise in an oblique path and display a bifid wake, and those with diameters in the range (3.7–8 mm) rise in intermittently oblique paths, showing an intermittent bifid wake of alternating vorticity. The droplets’ shapes in this range change from spherical into oblate ellipsoids of increasing eccentricity, followed by bi-ellipsoidal shapes with higher curvature on the downstream side. Even larger droplets (10–16 mm) rise in oscillatory, essentially vertical paths with drastically different wake structures, including deadzones and aperiodic or periodic vortex shedding. The largest considered droplets (diameter of 14 and 16 mm) display significant shape oscillations and vortex shedding is accompanied by a complex evolution of coherent vortex structures. Their rise paths are best described as zigzagging, but the bifurcation scenario seems to be substantially different from that leading to the zigzagging of air bubbles. In contrast to the rise behaviour of bubbles, helical paths are not observed in the present study.
Dynamics of the large-scale circulation in turbulent Rayleigh–Bénard convection with modulated rotation
Authors: Zhong Jin-Qiang , Sterl Sebastian , Li Hui-Min
Published: August 2015

We present measurements of the azimuthal rotation velocity $\dot{{\it\theta}}(t)$ and thermal amplitude ${\it\delta}(t)$ of the large-scale circulation in turbulent Rayleigh–Bénard convection with modulated rotation. Both $\dot{{\it\theta}}(t)$ and ${\it\delta}(t)$ exhibit clear oscillations at the modulation frequency ${\it\omega}$. Fluid acceleration driven by oscillating Coriolis force causes an increasing phase lag in $\dot{{\it\theta}}(t)$ when ${\it\omega}$ increases. The applied modulation produces oscillatory boundary layers and the resulting time-varying viscous drag modifies ${\it\delta}(t)$ periodically. Oscillation of $\dot{{\it\theta}}(t)$ with maximum amplitude occurs at a finite modulation frequency ${\it\omega}^{\ast }$. Such a resonance-like phenomenon is interpreted as a result of optimal coupling of ${\it\delta}(t)$ to the modulated rotation velocity. We show that an extended large-scale circulation model with a relaxation time for ${\it\delta}(t)$ in response to the modulated rotation provides predictions in close agreement with the experimental results.
Are Credit Default Swaps a Sideshow? Evidence That Information Flows from Equity to CDS Markets
Authors: Hilscher Jens , Pollet Joshua M. , Wilson Mungo
Published: August 2015

This article provides evidence that equity returns lead credit protection returns at daily and weekly frequencies, whereas credit protection returns do not lead equity returns. Our results indicate that informed traders are primarily active in the equity market rather than the credit default swap (CDS) market. These findings are consistent with standard theories of market selection by informed traders in which market selection is determined partially by transaction costs. We also find that credit protection returns respond more quickly during salient news events (earnings announcements) compared to days with similar equity returns and turnover. This evidence provides support for explanations related to investor inattention.
Suitability Checks and Household Investments in Structured Products
Authors: Chang Eric C. , Tang Dragon Yongjun , Zhang Miao Ben
Published: August 2015

The suitability of complex financial products for household investors is an important issue in light of consumer financial protection. The U.S. Dodd–Frank Act, for instance, mandates that distributors check suitability when selling structured products to retail investors. However, little empirical evidence exists on such transactions. Using data from Hong Kong, we find that investors purchase 8% more structured products, on average, when the suitability is not checked. The effect of suitability checks is more pronounced for less financially literate investors. Moreover, investors tend to buy products with lower risk-adjusted returns when product suitability is not checked.
‘Innocent’ Victims/‘Guilty’ Migrants: Hindi public sphere, caste and indentured women in colonial North India
Authors: GUPTA CHARU
Published: August 2015

In this article footnote 70 on page 20 should include the following: ‘Quoted in Ashutosh Kumar, “Anti-Indenture Bhojpuri Folk Songs and Poems from North India”, Man in India, 93 (4), 2013, p. 512 [509–19].’

On the same page, after the line ‘The victimized woman was glorified and acquired subjecthood only when she emulated the virtues and ideals of upper-caste Indian womanhood and wifely devotion, thereby overcoming the perceived stereotypes of Dalit woman’ the following footnote should have appeared: ‘Kumar, “Anti-Indenture Bhojpuri Folk Songs”, p. 513’.

The author regrets the error.
Public Opinion towards Return Migration: A Survey Experiment of Chinese Netizens
Authors: Tai Qiuqing , Truex Rory
Published: August 2015

China has adopted preferential measures in hopes of luring back overseas talent, but what determines individual attitudes towards returning migrants and policies promoting return migration? This paper addresses this question using an original survey experiment of Chinese netizens. We argue that attitudes towards return migration are driven by two competing perceptions: on one hand, skilled migrants are widely thought to have beneficial effects on the local economy; on the other, domestic citizens may be wary of policies that offer elite returnees excessive benefits. The findings imply that the CCP may face a delicate trade-off between the economic benefits of return migration and the social costs of increasing inequality.
Response
Authors: Sterelny Kim , Watkins Trevor
Published: August 2015

We would like to begin by thanking the commentators for their thoughtful, informed and, for the most part, generous responses. Even Ofer Bar-Yosef, while clearly disagreeing deeply with our whole approach, has invested precious resources of time and thought in our paper. We shall respond commentary by commentary, but there are some common themes in the responses, and we will note those as we go through.
English phonotactics
Authors: BAUER LAURIE
Published: August 2015

This article presents an analysis of the phonotactic structures of English presented inThe Cambridge English Pronouncing Dictionary, paying attention to morphological boundaries, the difference between stressed and unstressed syllables, the difference between native and non-native, and considering the distribution of vowels as well as consonants. The phonotactic status of names turns out to be unlike the status of other morphologically unanalysable words, and some new observations are made on consonant clusters as well as vowel sequences, which have previously been overlooked.
Sex differences in prevalence of overweight and obesity, and in extent of overweight index, in children and adolescents (3–18 years) from Kraków, Poland in 1983, 2000 and 2010
Authors: Kowal Małgorzata , Woronkowicz Agnieszka , Kryst Łukasz , Sobiecki Jan , Pilecki Maciej W
Published: August 2015

Objective

The increasing prevalence of overweight and obesity among children is now an important health problem. This fact, however, does not reflect the scale of the problem. The aim of the present study was to find how much the BMI threshold was exceeded in a population from Kraków.

Design

The study was based on three cross-sectional surveys conducted in 1983, 2000 and 2010. The prevalence of overweight and obesity was estimated based on the International Obesity Task Force cut-off points. In addition to these, an extent of overweight (EOW) index was calculated.

Setting

Poland.

Subjects

Children aged 3–18 years (n14 534) from Kraków.

Results

Between the populations examined in 1983 and 2010, the EOW index in boys rose by almost 10 %, and the prevalence of overweight and obesity by 39 %. In girls, however, the EOW index decreased by 45 %, while the prevalence of overweight and obesity remained at similar levels. Analyses in separate age groups showed that the EOW index increased only among early adolescents (150 % for boys, 94 % for girls) and late adolescents (390 % and 64 %, respectively).

Conclusions

The observed increased prevalence of overweight and obesity mainly concerned boys and was accompanied by an increase in the amount by which the BMI threshold values were exceeded.
Rotman lens combined with wide bandwidth antenna array for 60 GHz RFID applications
Authors: Attaran Ali , Rashidzadeh Rashid , Muscedere Roberto
Published: August 2015

This paper presents a novel technique to design a Rotman lens feeding a wide bandwidth microstrip patch antenna array for 60 GHz radio frequency identification (RFID) applications. The proposed scheme supports both location positioning and increases the communication range through beam forming. The antenna array is designed using λ/4 microstrip transmission lines to support high gain, directivity, and bandwidth. The progressive phase delay using the Rotman lens is realized independently using transmission lines to reduce the complexity of the design and improve the performance parameters. The dummy ports are terminated by λ/4 radial stubs which eliminates the need for via holes and expensive connectors which reduces the fabrication costs.
Rechenleistung und Fingergnosie: Besteht ein Zusammenhang?
Authors: Kohn Juliane , Kucian Karin , Wuithschick Elisabeth , Mayer Verena , Rauscher Larissa , McCaskey Ursina , Käser Tanja , Poltz Nadine , Wyschkon Anne , Quandte Sabine , Esser Günter , von Aster Michael
Published: August 2015

Zusammenfassung. Kinder nehmen oft automatisch ihre Finger zu Hilfe, um zu zählen und zu rechnen. Zudem scheint es so, dass Kinder, die ihre eigenen Finger bei geschlossenen Augen besser unterscheiden und benennen können (= Fingergnosie) auch bessere Rechner sind.

Das Ziel dieser Studie war es, den Zusammenhang zwischen Fingergnosie und Rechenleistung sowie Zahlenraumvorstellung bei Kindern mit und ohne unterdurchschnittliche Rechenleistungen zu untersuchen. Dazu wurden 53 unterdurchschnittliche und 62 durchschnittliche Rechner im Alter von 7 bis 11 Jahren getestet.

Die Fingergnosie wurde mittels eines neu entwickelten Verfahrens erfasst. Über die klassische quantitative Methode der Fingergnosietestung (Fingergnosie-Anzahl) hinaus, wurde ein qualitatives Distanzmaß (Fingergnosie-Distanz) eingeführt. Diese beiden Maße wurden anschließend in Relation zu Variablen der Rechenleistung und Zahlenraumvorstellung gesetzt.

Die Ergebnisse zeigten, dass die qualitative Bestimmung der Fingergnosie das sensiblere Maß darstellt, was wahrscheinlich auf den erhöhten Schwierigkeitsgrad zurückzuführen ist. Es fanden sich allerdings lediglich Zusammenhänge der Fingergnosie-Distanz mit dem Erfassen von Punktmengen < 10 und der visuell-räumlichen Aufmerksamkeitsspanne. Keines der beiden Fingergnosiemaße wies signifikante Zusammenhänge zur Bearbeitung von Rechen- und Zahlenstrahlaufgaben sowie den Intelligenzmaßen und der Lese- und Rechtschreibleistung auf. Darüber hinaus unterschieden sich unterdurchschnittliche und durchschnittliche Rechner in keinem der Fingergnosiemaße.

Demnach scheint bei Kindern im Alter zwischen 7 und 11 Jahren lediglich ein Zusammenhang zwischen der Fingergnosie und ganz basalen entwicklungspsychologisch frühen Zahlenverarbeitungsfähigkeiten zu bestehen, während keine Belege für eine Bedeutung der Fingergnosie für später erworbene höhere Rechenfertigkeiten gefunden wurden.
Fingerrechnen: Aspekte aus didaktischer Sicht
Authors: Lorenz Jens Holger
Published: August 2015

Zusammenfassung. Zunächst wird ein Einblick in die historische Entwicklung der Zahlen und Möglichkeiten des Rechnens gegeben. Die Entwicklung des Zählens und der Gebrauch der Zahlen beim Kinde schließen sich an. Die Verwendung der Finger ist normal. Wann stößt das „Fingerrechnen“ an seine Grenzen und sollte durch weiter tragende Strategien abgelöst werden, um einen gut verlaufenden Lernprozess der Mathematik zu begünstigen?
Internalizing Problems in Children and Adolescents With Math Disability
Authors: Graefen Johanna , Kohn Juliane , Wyschkon Anne , Esser Günter
Published: August 2015

Research has shown that learning disabilities are associated with internalizing problems in (pre)adolescents. In order to examine this relationship for math disability (MD), math achievement and internalizing problem scores were measured in a representative group of 1,436 (pre)adolescents. MD was defined by a discrepancy between math achievement and IQ. Internalizing problems were measured through a multi-informant (parents, teachers, self-report) approach. The results revealed that MD puts (pre)adolescents at a higher risk for internalizing problems. External and self-ratings differed between boys and girls, indicating that either they show distinct internalizing symptoms or they are being perceived differently by parents and teachers. Results emphasize the importance of both a multi-informant approach and the consideration of gender differences when measuring internalizing symptomatology of children with MD. For an optimal treatment of MD, depressive and anxious symptoms need to be considered.
Working Memory and Number Sense as Predictors of Mathematical (Dis-)Ability
Authors: Kroesbergen Evelyn H. , van Dijk Marloes
Published: August 2015

Recent research has pointed to two possible causes of mathematical (dis-)ability: working memory and number sense, although only few studies have compared the relations between working memory and mathematics and between number sense and mathematics. In this study, both constructs were studied in relation to mathematics in general, and to mathematical learning disabilities (MLD) in particular. The sample consisted of 154 children aged between 6 and 10 years, including 26 children with MLD. Children performing low on either number sense or visual-spatial working memory scored lower on math tests than children without such a weakness. Children with a double weakness scored the lowest. These results confirm the important role of both visual-spatial working memory and number sense in mathematical development.
Pathways of Number Line Development in Children
Authors: Friso-van den Bos Ilona , Van Luit Johannes E. H. , Kroesbergen Evelyn H. , Xenidou-Dervou Iro , Van Lieshout Ernest C. D. M. , Van der Schoot Menno , Jonkman Lisa M.
Published: August 2015

Dyscalculia, or mathematics learning disability, has received growing attention in recent years. Working memory and number sense are hypothesized to form important determinants of dyscalculia, but longitudinal assessments of number sense in children with or at-risk for dyscalculia are scarce. The current study investigated number line development in first and second grade, in addition to kindergarten predictors and mathematical proficiency as an outcome. Children (n = 396) could be divided into three latent growth classes: at-risk, catch-up, and typical, based on their number line development. Growth was predicted by kindergarten number sense and verbal working memory. According to the class to which they were assigned, children differed in mathematical proficiency at the end of grade 2. The current study makes an important contribution to the understanding of risk for dyscalculia, showing that children at-risk can be distinguished based on their number line development, and that kindergarten variables are predictive of subsequent development.
Focusing Attention on Climate Change and Pacific Island Nations
Authors: Wuebbles Donald , Higgins Wayne , Chien Hui-Chen
Published: August 2015

The 2014 Pan Pacific Partnership on Climate Change Adaptation; Taipei, Taiwan, 29 September to 2 October 2014
Competitive strategies differentiate closely related species of marine actinobacteria
Authors: Patin Nastassia V , Duncan Katherine R , Dorrestein Pieter C , Jensen Paul R
Published: August 2015

Although competition, niche partitioning, and spatial isolation have been used to describe the ecology and evolution of macro-organisms, it is less clear to what extent these principles account for the extraordinary levels of bacterial diversity observed in nature. Ecological interactions among bacteria are particularly challenging to address due to methodological limitations and uncertainties over how to recognize fundamental units of diversity and link them to the functional traits and evolutionary processes that led to their divergence. Here we show that two closely related marine actinomycete species can be differentiated based on competitive strategies. Using a direct challenge assay to investigate inhibitory interactions with members of the bacterial community, we observed a temporal difference in the onset of inhibition. The majority of inhibitory activity exhibited by Salinispora arenicola occurred early in its growth cycle and was linked to antibiotic production. In contrast, most inhibition by Salinispora tropica occurred later in the growth cycle and was more commonly linked to nutrient depletion or other sources. Comparative genomics support these differences, with S. arenicola containing nearly twice the number of secondary metabolite biosynthetic gene clusters as S. tropica, indicating a greater potential for secondary metabolite production. In contrast, S. tropica is enriched in gene clusters associated with the acquisition of growth-limiting nutrients such as iron. Coupled with differences in growth rates, the results reveal that S. arenicola uses interference competition at the expense of growth, whereas S. tropica preferentially employs a strategy of exploitation competition. The results support the ecological divergence of two co-occurring and closely related species of marine bacteria by providing evidence they have evolved fundamentally different strategies to compete in marine sediments.
A genome-wide analysis of putative functional and exonic variation associated with extremely high intelligence
Authors: Spain S L , Pedroso I , Kadeva N , Miller M B , Iacono W G , McGue M , Stergiakouli E , Smith G D , Putallaz M , Lubinski D , Meaburn E L , Plomin R , Simpson M A
Published: August 2015

Although individual differences in intelligence (general cognitive ability) are highly heritable, molecular genetic analyses to date have had limited success in identifying specific loci responsible for its heritability. This study is the first to investigate exome variation in individuals of extremely high intelligence. Under the quantitative genetic model, sampling from the high extreme of the distribution should provide increased power to detect associations. We therefore performed a case–control association analysis with 1409 individuals drawn from the top 0.0003 (IQ >170) of the population distribution of intelligence and 3253 unselected population-based controls. Our analysis focused on putative functional exonic variants assayed on the Illumina HumanExome BeadChip. We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence. Moreover, no significant associations were found for multiple rare alleles within individual genes. However, analyses using genome-wide similarity between unrelated individuals (genome-wide complex trait analysis) indicate that the genotyped functional protein-altering variation yields a heritability estimate of 17.4% (s.e. 1.7%) based on a liability model. In addition, investigation of nominally significant associations revealed fewer rare alleles associated with extremely high intelligence than would be expected under the null hypothesis. This observation is consistent with the hypothesis that rare functional alleles are more frequently detrimental than beneficial to intelligence.
Universal self-field critical current for thin-film superconductors
Authors: Talantsev E. F. , Tallon J. L.
Published: August 2015

For any practical superconductor the magnitude of the critical current density, Jc, is crucially important. It sets the upper limit for current in the conductor. Usually Jc falls rapidly with increasing external magnetic field, but even in zero external field the current flowing in the conductor generates a self-field that limits Jc. Here we show for thin films of thickness less than the London penetration depth, λ, this limiting Jc adopts a universal value for all superconductors—metals, oxides, cuprates, pnictides, borocarbides and heavy Fermions. For type-I superconductors, it is Hc/λ where Hc is the thermodynamic critical field. But surprisingly for type-II superconductors, we find the self-field Jc is Hc1/λ where Hc1 is the lower critical field. Jc is thus fundamentally determined and this provides a simple means to extract absolute values of λ(T) and, from its temperature dependence, the symmetry and magnitude of the superconducting gap.
Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems
Authors: Wohlhüter Phillip , Bryan Matthew Thomas , Warnicke Peter , Gliga Sebastian , Stevenson Stephanie Elizabeth , Heldt Georg , Saharan Lalita , Suszka Anna Kinga , Moutafis Christoforos , Chopdekar Rajesh Vilas , Raabe Jörg , Thomson Thomas , Hrkac Gino , Heyderman Laura Jane
Published: August 2015

Vortices are fundamental magnetic topological structures characterized by a curling magnetization around a highly stable nanometric core. The control of the polarization of this core and its gyration is key to the utilization of vortices in technological applications. So far polarization control has been achieved in single-material structures using magnetic fields, spin-polarized currents or spin waves. Here we demonstrate local control of the vortex core orientation in hybrid structures where the vortex in an in-plane Permalloy film coexists with out-of-plane maze domains in a Co/Pd multilayer. The vortex core reverses its polarization on crossing a maze domain boundary. This reversal is mediated by a pair of magnetic singularities, known as Bloch points, and leads to the transient formation of a three-dimensional magnetization structure: a Bloch core. The interaction between vortex and domain wall thus acts as a nanoscale switch for the vortex core polarization.
Nonsynaptic junctions on myelinating glia promote preferential myelination of electrically active axons
Authors: Wake Hiroaki , Ortiz Fernando C. , Woo Dong Ho , Lee Philip R. , Angulo María Cecilia , Fields R. Douglas
Published: August 2015

The myelin sheath on vertebrate axons is critical for neural impulse transmission, but whether electrically active axons are preferentially myelinated by glial cells, and if so, whether axo-glial synapses are involved, are long-standing questions of significance to nervous system development, plasticity and disease. Here we show using an in vitro system that oligodendrocytes preferentially myelinate electrically active axons, but synapses from axons onto myelin-forming oligodendroglial cells are not required. Instead, vesicular release at nonsynaptic axo-glial junctions induces myelination. Axons releasing neurotransmitter from vesicles that accumulate in axon varicosities induces a local rise in cytoplasmic calcium in glial cell processes at these nonsynaptic functional junctions, and this signalling stimulates local translation of myelin basic protein to initiate myelination.
Harmonic force spectroscopy measures load-dependent kinetics of individual human β-cardiac myosin molecules
Authors: Sung Jongmin , Nag Suman , Mortensen Kim I. , Vestergaard Christian L. , Sutton Shirley , Ruppel Kathleen , Flyvbjerg Henrik , Spudich James A.
Published: August 2015

Molecular motors are responsible for numerous cellular processes from cargo transport to heart contraction. Their interactions with other cellular components are often transient and exhibit kinetics that depend on load. Here, we measure such interactions using ‘harmonic force spectroscopy’. In this method, harmonic oscillation of the sample stage of a laser trap immediately, automatically and randomly applies sinusoidally varying loads to a single motor molecule interacting with a single track along which it moves. The experimental protocol and the data analysis are simple, fast and efficient. The protocol accumulates statistics fast enough to deliver single-molecule results from single-molecule experiments. We demonstrate the method’s performance by measuring the force-dependent kinetics of individual human β-cardiac myosin molecules interacting with an actin filament at physiological ATP concentration. We show that a molecule’s ADP release rate depends exponentially on the applied load, in qualitative agreement with cardiac muscle, which contracts with a velocity inversely proportional to external load.
Spatiotemporal regulation of Heterochromatin Protein 1- alpha oligomerization and dynamics in live cells
Authors: Hinde Elizabeth , Cardarelli Francesco , Gratton Enrico
Published: August 2015

Heterochromatin protein 1 (HP1) is a central factor in establishing and maintaining the heterochromatin state. As consequence of playing a structural role in heterochromatin, HP1 proteins can have both an activating as well as repressive function in gene expression. Here we probe how oligomerisation of the HP1-α isoform modulates interaction with chromatin, by spatially resolved fluorescence correlation spectroscopy (FCS). We find from fluctuation analysis of HP1-α dynamics that this isoform exists as a dimer around the periphery of heterochromatin foci and these foci locally rotate with characteristic turn rates that range from 5–100ms. From inhibition of HP1-α homo-oligomerization we find the slow turn rates (20–100 ms) are dimer dependent. From treatment with drugs that disrupt or promote chromatin compaction, we find that HP1-α dimers spatially redistribute to favor fast (5–10 ms) or slow (20–100 ms) turn rates. Collectively our results demonstrate HP1-α oligomerization is critical to the maintenance of heterochromatin and the tunable dynamics of this HP1 isoform.
A Polymer Lithium-Oxygen Battery
Authors: Elia Giuseppe Antonio , Hassoun Jusef
Published: August 2015

Herein we report the characteristics of a lithium-oxygen battery using a solid polymer membrane as the electrolyte separator. The polymer electrolyte, fully characterized in terms of electrochemical properties, shows suitable conductivity at room temperature allowing the reversible cycling of the Li-O2battery with a specific capacity as high as 25,000 mAh gC−1reflected in a surface capacity of 12.5 mAh cm−2. The electrochemical formation and dissolution of the lithium peroxide during Li-O2polymer cell operation is investigated by electrochemical techniques combined with X-ray diffraction study, demonstrating the process reversibility. The excellent cell performances in terms of delivered capacity, in addition to its solid configuration allowing the safe use of lithium metal as high capacity anode, demonstrate the suitability of the polymer lithium-oxygen as high-energy storage system.
Approaching rational epitope vaccine design for hepatitis C virus with meta-server and multivalent scaffolding
Authors: He Linling , Cheng Yushao , Kong Leopold , Azadnia Parisa , Giang Erick , Kim Justin , Wood Malcolm R. , Wilson Ian A. , Law Mansun , Zhu Jiang
Published: August 2015

Development of a prophylactic vaccine against hepatitis C virus (HCV) has been hampered by the extraordinary viral diversity and the poor host immune response. Scaffolding, by grafting an epitope onto a heterologous protein scaffold, offers a possible solution to epitope vaccine design. In this study, we designed and characterized epitope vaccine antigens for the antigenic sites of HCV envelope glycoproteins E1 (residues 314–324) and E2 (residues 412–423), for which neutralizing antibody-bound structures are available. We first combined six structural alignment algorithms in a “scaffolding meta-server” to search for diverse scaffolds that can structurally accommodate the HCV epitopes. For each antigenic site, ten scaffolds were selected for computational design and the resulting epitope scaffolds were analyzed using structure-scoring functions and molecular dynamics simulation. We experimentally confirmed that three E1 and five E2 epitope scaffolds bound to their respective neutralizing antibodies, but with different kinetics. We then investigated a “multivalent scaffolding” approach by displaying 24 copies of an epitope scaffold on a self-assembling nanoparticle, which markedly increased the avidity of antibody binding. Our study thus demonstrates the utility of a multi-scale scaffolding strategy in epitope vaccine design and provides promising HCV immunogens for further assessment in vivo.
Maximal rectification ratios for idealized bi-segment thermal rectifiers
Authors: Shih Tien-Mo , Gao Zhaojing , Guo Ziquan , Merlitz Holger , Pagni Patrick J. , Chen Zhong
Published: August 2015

Thermal rectifiers whose forward heat fluxes are greater than reverse counterparts have been extensively studied. Here we have discovered, idealized and derived the ultimate limit of such rectification ratios, which are partially validated by numerical simulations, experiments and micro-scale Hamiltonian-oscillator analyses. For rectifiers whose thermal conductivities (κ) are linear with the temperature, this limit is simply a numerical value of 3. For those whose conductivities are nonlinear with temperatures, the maxima equal κmax/κmin, where two extremes denote values of the solid segment materials that can be possibly found or fabricated within a reasonable temperature range. Recommendations for manufacturing high-ratio rectifiers are also given with examples. Under idealized assumptions, these proposed rectification limits cannot be defied by any bi-segment thermal rectifiers.
Glucocorticoid affects dendritic transport of BDNF-containing vesicles
Authors: Adachi Naoki , Numakawa Tadahiro , Nakajima Shingo , Fukuoka Masashi , Odaka Haruki , Katanuma Yusuke , Ooshima Yoshiko , Hohjoh Hirohiko , Kunugi Hiroshi
Published: August 2015

Brain-derived neurotrophic factor (BDNF) is essential for neuronal survival, differentiation and functions in the central nervous system (CNS). Because BDNF protein is sorted into secretory vesicles at the trans-Golgi network in the cell body after translation, transport of BDNF-containing vesicles to the secretion sites is an important process for its function. Here we examined the effect of dexamethasone (DEX), a synthetic glucocorticoid, on BDNF-containing vesicle transport and found that DEX decreased the proportion of stationary vesicles and increased velocity of the microtubule-based vesicle transport in dendrites of cortical neurons. Furthermore, DEX increased huntingtin (Htt) protein levels via glucocorticoid receptor (GR) activation and reduction in the amount of Htt by a specific shRNA reversed the action of DEX on BDNF vesicle transport. Given that Htt protein is a positive regulator for the microtubule-dependent vesicular transport in neurons, our data suggest that glucocorticoid stimulates BDNF vesicle transport through upregulation of Htt protein levels.
Robust quantum control using smooth pulses and topological winding
Authors: Barnes Edwin , Wang Xin , Das Sarma S.
Published: August 2015

The greatest challenge in achieving the high level of control needed for future technologies based on coherent quantum systems is the decoherence induced by the environment. Here, we present an analytical approach that yields explicit constraints on the driving field which are necessary and sufficient to ensure that the leading-order noise-induced errors in a qubit’s evolution cancel exactly. We derive constraints for two of the most common types of noise that arise in qubits: slow fluctuations of the qubit energy splitting and fluctuations in the driving field itself. By theoretically recasting a phase in the qubit’s wavefunction as a topological winding number, we can satisfy the noise-cancelation conditions by adjusting driving field parameters without altering the target state or quantum evolution. We demonstrate our method by constructing robust quantum gates for two types of spin qubit: phosphorous donors in silicon and nitrogen-vacancy centers in diamond.