bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and factors associated with parental concerns about development detected by theParents’ Evaluation of Developmental Status (PEDS)at 6-month, 12-month and 18-month well-child checks in a birth cohort
Authors: Woolfenden Susan , Eapen Valsamma , Jalaludin Bin , Hayen Andrew , Kemp Lynn , Dissanyake Cheryl , Hendry Alexandra , Axelsson Emma , Overs Bronwyn , Eastwood John , Črnčec Rudi , McKenzie Anne , Beasley Deborah , Murphy Elisabeth , Williams Katrina
Published: September 2016

Objectives

Early identification of developmental vulnerability is vital. This study aimed to estimate the prevalence of moderate or high developmental risk on theParents' Evaluation of Developmental Status(PEDS)at 6-month, 12-month and 18-month well-child checks; identify associated risk factors; and examine documentation of thePEDSat well-child checks.

Design, participants

A prospective birth cohort of 2025 children with 50% of those approached agreeing to participate. Demographic data were obtained via questionnaires and linked electronic medical records. Telephone interviews were conducted with parents to collectPEDSdata.

Primary and secondary outcomes

Multiple logistic regression analyses identified risk factors for moderate or high developmental risk on thePEDS. A Cumulative Risk Index examined the impact of multiple risk factors on developmental risk and documentation of thePEDSat the well-child checks.

Results

Of the original cohort, 792 (39%) had 6-month, 649 (32%) had 12-month and 565 (28%) had 18-monthPEDSdata. Parental concerns indicating moderate or high developmental risk on thePEDSwere 27% (95% CI 24 to 30) at 6 months, 27% (95% CI 24 to 30) at 12 months and 33% (95% CI 29 to 37) at 18 months. Factors associated with moderate or high developmental risk were perinatal risk (OR 12 months: 1.7 (95% CI 1.1 to 2.7)); maternal Middle Eastern or Asian nationality (OR 6 months: 1.6 (95% CI 1.1 to 2.4)), (OR 12 months: 1.7 (95% CI 1.1 to 2.7)); and household disadvantage (OR 6 months: 1.5 (95% CI 1.0 to 2.2). As the number of risk factors increased the odds increased for high or moderate developmental risk and no documentation of thePEDSat well-child checks.

Conclusions

Children with multiple risk factors are more likely to have parental concerns indicating developmental vulnerability using thePEDSand for these concerns to not be documented.
Delay to mental healthcare in a cohort of Canadian Armed Forces personnel with deployment-related mental disorders, 2002–2011: a retrospective cohort study
Authors: Boulos David , Zamorski Mark A
Published: September 2016

Objective

To assess whether the delay to care among Canadian Armed Forces (CAF) personnel who sought care for a mental disorder changed over time and in association with CAF mental health system augmentations.

Design

A stratified, random sample (n=2014) was selected for study from an Afghanistan-deployed cohort (N=30 513) and the 415 (weighted N=4108) individuals diagnosed with an Afghanistan service-related mental disorder were further assessed. Diagnosis-related data were abstracted from medical records (22 June 2010 to 30 May 2011). Other data were extracted from administrative databases. Delay to care was assessed across five mental health system eras: 2002/2004, 2005/2006, 2007, 2008 and 2009/2010. Weighted Cox proportional hazards regression assessed the association between era, handled as a time-dependent covariate, and the outcome while controlling for a broad range of potential confounders (ie, sociodemographic, military and clinical characteristics). Taylor series linearisation methods and sample design weights were applied in generating descriptive and regression analysis statistics.

Primary outcome

The outcome was the delay to mental healthcare, defined as the latency from most recent Afghanistan deployment return date to diagnosis date, among individuals with an Afghanistan service-related mental disorder diagnosis.

Results

Mean delay to care was 551 days (95% CI 501 to 602); the median was 400 days. Delay to care decreased in subsequent eras relative to 2002/2004; however, only the most recent era (2009/2010) was statistically significant (adjusted HR (aHR): 3.01 (95% CI 1.91 to 4.73)). Men, operations support occupations, higher ranks, non-musculoskeletal comorbidities and fewer years of military service were also independently associated with longer delays to care.

Conclusions

CAF mental health system changes were associated with reduced delays to mental healthcare. Further evaluation research is needed to identify the key system changes that were most impactful.
Investigating the effects of 6 months extended duration, in-centre nocturnal versus conventional haemodialysis treatment: a non-randomised, controlled feasibility study
Authors: Churchward Darren R , Graham-Brown Matthew P M , Preston Robert , Pickering Warren , McCann Gerry P , Burton James O
Published: September 2016

Introduction

In-centre nocturnal haemodialysis (INHD) is an underutilised dialysis regimen that can potentially provide patients with better clinical outcomes due to extended treatment times. We have established an INHD programme within our clinical network, fulfilling a previously unmet patient need. This feasibility study aims to gather sufficient data on numerous outcome measures to inform the design of a multicentre randomised controlled trial that will establish the potential benefits of INHD and increase the availability of this service nationally and internationally.

Methods and analysis

This will be a non-randomised controlled study. Prevalent patients on haemodialysis (HD) will electively change from a conventional in-centre HD regimen of 4 hours thrice weekly to a regimen of extended treatment times (5–8 hours) delivered in-centre overnight thrice weekly. After recruitment of the INHD cohort, a group of patients matched for age, gender and dialysis vintage will be selected from patients remaining on a conventional daytime dialysis programme. Outcome measures will include left ventricular mass as measured by MRI, physical performance measured by the short physical performance battery and physical activity measured by accelerometry. Additionally we will measure quality of life using validated questionnaires, nutritional status by bioimpedance spectroscopy and food diaries, and blood sampling for markers of cardiovascular disease, systemic inflammation. Suitable statistical tests shall be used to analyse the data. We will use omnibus tests to observe changes over the duration of the intervention and between groups. We will also look for associations between outcome measures that may warrant further investigation. These data will be used to inform the power calculation for future studies.

Ethics and dissemination

A favourable opinion was granted by Northampton Research Ethics Committee (15/EM/0268). It is anticipated that results of this study will be presented at national and international meetings, with reports being published in journals during 2017.

Trial registration number

ISRCTN16672784.
Multicentre, prospective, randomised, open-label, blinded end point trial of the efficacy of allopurinol therapy in improving cardiovascular outcomes in patients with ischaemic heart disease: protocol of the ALL-HEART study
Authors: Mackenzie Isla S , Ford Ian , Walker Andrew , Hawkey Chris , Begg Alan , Avery Anthony , Taggar Jaspal , Wei Li , Struthers Allan D , MacDonald Thomas M
Published: September 2016

Introduction

Ischaemic heart disease (IHD) is one of the most common causes of death in the UK and treatment of patients with IHD costs the National Health System (NHS) billions of pounds each year. Allopurinol is a xanthine oxidase inhibitor used to prevent gout that also has several positive effects on the cardiovascular system. The ALL-HEART study aims to determine whether allopurinol improves cardiovascular outcomes in patients with IHD.

Methods and analysis

The ALL-HEART study is a multicentre, controlled, prospective, randomised, open-label blinded end point (PROBE) trial of allopurinol (up to 600 mg daily) versus no treatment in a 1:1 ratio, added to usual care, in 5215 patients aged 60 years and over with IHD. Patients are followed up by electronic record linkage and annual questionnaires for an average of 4 years. The primary outcome is the composite of non-fatal myocardial infarction, non-fatal stroke or cardiovascular death. Secondary outcomes include all-cause mortality, quality of life and cost-effectiveness of allopurinol. The study will end when 631 adjudicated primary outcomes have occurred. The study is powered at 80% to detect a 20% reduction in the primary end point for the intervention. Patient recruitment to the ALL-HEART study started in February 2014.

Ethics and dissemination

The study received ethical approval from the East of Scotland Research Ethics Service (EoSRES) REC 2 (13/ES/0104). The study is event-driven and results are expected after 2019. Results will be reported in peer-reviewed journals and at scientific meetings. Results will also be disseminated to guideline committees, NHS organisations and patient groups.

Trial registration number

32017426, pre-results.
Examining the role of tenure, household crowding and housing affordability on psychological distress, using longitudinal data
Authors: Pierse Nevil , Carter Kristie , Bierre Sarah , Law David , Howden-Chapman Philippa
Published: September 2016

Background

The association between good mental health and housing circumstances is well established. Tenure, household crowding and housing affordability have all been linked to mental health and psychological distress. These cross-sectional relationships are collinear and confounded, and so provide little information on the possible effects of changing housing circumstance on mental health or psychological distress. To do this longitudinal data are needed.

Methods

In this paper we use the longitudinal data from the 11 500 NZ households in the Survey of Families, Income and Employment (SoFIE), conducted in New Zealand from 2002 to 2010. We examine the cross-sectional associations of housing factors on psychological distress and use fixed-effects modelling of longitudinal data to examine any effects of changes in selected housing factors on changes in psychological distress.

Results

We show large significant cross-sectional associations between all the housing circumstances and psychological distress. These associations were not present in the fixed-effects models. Only changes in individual deprivation had a significant effect on changes in psychological distress. While a significant effect was found for moves to and from houses with a two-bedroom deficit, the small number of moves of this type means these results are not robust.

Conclusions

These results show that the effect of house ownership and housing affordability on psychological distress is likely to be confounded in the cross-sectional models. Therefore, marginal changes to these housing factors are unlikely to yield large reductions in psychological distress. Our results suggest that reductions in psychological distress are more likely to be seen through interventions that target individual socioeconomic deprivation and severe household crowding.
Assessing morbidity compression in two cohorts from the Health and Retirement Study
Authors: Beltrán-Sánchez Hiram , Jiménez Marcia P , Subramanian S V
Published: September 2016

Background

Increases in life expectancy are hypothesised to be associated with shorter proportional time spent with morbidity (compression of morbidity). We assessed whether this has occurred among older adults in the USA during the 1990s and 2000s.

Methods

We used data from the Health and Retirement Study to estimate a morbidity score based on eight chronic conditions and compare it (1) prospectively between two age-matched cohorts in 1992 and 2004 over a 6-year follow-up, and (2) retrospectively in the three waves prior to death among respondents who die in (1998–2004) and (2004–2010).

Results

Prospective assessment shows significantly higher prevalence in 6 of eight chronic conditions in the 2000s, with 37% higher diabetes prevalence. A retrospective evaluation shows significantly higher prevalence in 7 of eight chronic conditions in the three waves prior to death for (2004–2010) versus (1998–2004), with 41% higher prevalence of arthritis. Importantly, the farther away from time of death, the higher the average number of chronic conditions in (2004–2010).

Conclusions

Using the largest longitudinal ageing study in the USA, we found no clear evidence of compression of morbidity as measured by self-reported chronic disease. Older adults in the USA may be experiencing greater disease burden in recent times.
Strategies for recruiting representative samples of Asian Americans for a population-based case–control study
Authors: Wong Celeste K , Horn-Ross Pamela L , Gee Gilbert C , Shariff-Marco Salma , Quach Thu , Allen Laura , Bautista Roxanna , La Chica Patricia Quema , Tseng Winston , Chang Pancho , Clarke Christina A , Yang Juan , Le Gem M , Canchola Alison , Irwin Melinda L , Lee Sandra Soo-Jin , Gomez Scarlett Lin
Published: September 2016

Background

Data are limited on effective methods for recruiting persons, especially from ethnically diverse populations, into population-based studies. The goal of this study was to evaluate the variation among and representativeness of controls identified using multiple methods for a population-based case–control study of breast cancer among Asian Americans, Native Hawaiians and Pacific Islanders (AANHPIs) in the San Francisco Bay Area.

Methods

We used a unique combination of targeted recruitment strategies, including address-based sampling, community-based methods, and internet-based and media-based approaches for recruiting controls, frequency matched on age and ethnicity to a population-based sample of cases. To characterise the participating controls, we compared the distribution of sociodemographic characteristics and cancer risk factors between recruitment sources using χ2tests. To ensure that the controls we recruited were representative of the underlying at-risk population, we compared characteristics of the controls, by ethnicity and in aggregate, to data from the California Health Interview Survey (CHIS), and adjusted the relative mix of recruitment strategies throughout the study as needed to achieve representativeness.

Results

As expected, controls (n=483) recruited by any single method were not representative. However, when aggregated across methods, controls were largely representative of the underlying source population, as characterised by CHIS, with regard to the characteristics under study, including nativity, education, marital status and body mass index.

Conclusions

A multimode approach using targeted recruitment strategies is an effective and feasible alternative to using a single recruitment method in identifying a representative, diverse control sample for population-based studies.
The long-term prognosis of cardiovascular disease and all-cause mortality for metabolically healthy obesity: a systematic review and meta-analysis
Authors: Zheng Ruizhi , Zhou Dan , Zhu Yimin
Published: September 2016

Background

Metabolically healthy obese phenotype (MHO) refers to obese individuals with absence of metabolic abnormalities such as dyslipidaemia, insulin resistance and hypertension. Many studies reported the long-term prognosis of MHO on diseases and mortality with inconsistent results.

Methods

We performed a meta-analysis to assess the risks of cardiovascular (CV) events and all-cause mortality for MHO individuals. Original prospective observational studies were searched in Medline, EMBASE, Web of Science and Cochrane library up to 30 September 2015. In this meta-analysis, the relative risk (RR) calculated on the basis of the incident number of disease events and deaths in participants and the corresponding multivariable-adjusted HR were both extracted to calculate pooled risk estimates. A random-effects model was used if there was heterogeneity among studies; otherwise, the fixed-effects model was used.

Results

22 prospective studies, involving 584 799 participants, were archived in the analyses. With metabolically healthy normal weight as the reference, the MHO phenotype was associated with a higher risk of CV events (RR 1.50, 95% CI 1.27 to 1.77; HR 1.60, 95% CI 1.38 to 1.84). However, MHO individuals were not associated with increased risk of all-cause mortality (RR 1.18, 95% CI 0.83 to 1.66; HR 1.07, 95% CI 0.92 to 1.25).

Conclusions

The meta-analysis confirms a positive association between a metabolically healthy obese phenotype and the risk of CV events. However, higher risk for all-cause mortality is not evident in metabolically healthy obese individuals.
Assessing women's satisfaction with family planning services in Mozambique
Authors: Chavane Leonardo , Dgedge Martinho , Bailey Patricia , Loquiha Osvaldo , Aerts Marc , Temmerman Marleen
Published: September 2016

Background

The contraceptive prevalence rate in Mozambique was estimated as 11.3% in the last Demographic and Health Survey. The impact of family planning (FP) on women's health and on the reduction of maternal mortality is well known.

Methods

Acknowledging the importance of user satisfaction in the utilisation of health services, exit interviews were used to assess women's satisfaction with FP services in Mozambique. The survey, conducted in 174 health facilities, was representative at the national level, covered all provinces, and both urban and rural areas.

Results

Overall, 86% of respondents were satisfied with FP services, but issues such as insufficient supplies of oral contraceptives and the low quality of healthcare provider/client interactions were given as reasons for women's dissatisfaction.

Conclusion

Defined actions at the level of health service provision are needed to tackle the identified issues and ensure improved satisfaction with, and better utilisation of, FP services in Mozambique.
Association betweenRANK, RANKLandOPGpolymorphisms with ACPA and erosions in rheumatoid arthritis: results from a meta-analysis involving three French cohorts
Authors: Ruyssen-Witrand Adeline , Degboé Yannick , Cantagrel A , Nigon D , Lukas C , Scaramuzzino S , Allanore Y , Vittecoq O , Schaeverbeke T , Morel J , Sibilia J , Cambon-Thomsen A , Dieudé P , Constantin A
Published: September 2016

Objectives

The RANK/RANKL/osteoprotegerin (OPG) system plays a central role in the pathogenesis of bone erosions in rheumatoid arthritis (RA). The aim of this study was to test the association between 11 single-nucleotide polymorphisms (SNPs) located onRANK, RANKLandOPGgenes and anticitrullinated peptide antibody (ACPA) presence or erosions in RA.

Methods

Patients: This work was performed on three independent samples of French patients with RA: the Etude de Suivi des PolyArthrites Indifférenciées Récentes (ESPOIR) (n=632), Rangueil Midi-Pyrénées (RMP) (n=249) and French Rheumatoid Arthritis Genetic Consortium (FRAGC) (n=590) cohorts. Genotyping: the genotyping of 11 SNPs located onRANK,RANKLandOPGwere performed by PCR. Statistical analyses: The association between the genotypes with ACPA or erosions was first tested in the ESPOIR cohort using a χ2test and, in the case of significant association, replicated in the RMP and FRACG cohorts. A meta-analysis on the three cohorts was performed using the Mantel-Haenszel method.

Results

One SNP onRANK(rs8086340) and three SNPs onRANKL(rs7984870, rs7325635, rs1054016) were significantly associated with ACPA presence, while one SNP onOPG(rs2073618) and one SNP onRANKL(rs7325635) were significantly associated with erosions in the ESPOIR cohort. Following meta-analysis performed on the three samples, the SNP onRANKand the GGG haplotype of the three SNPs located onRANKLwere both significantly associated with ACPA presence, while only the SNP onOPGremained significantly associated with erosions.

Conclusions

This study identified one SNP located onRANK, one haplotype onRANKLassociated with ACPA presence, and one SNP located onOPGassociated with erosions in three different samples of French patients with RA.
Geographic variation in floral traits is associated with environmental and genetic differences among populations of the mixed mating species Collinsia heterophylla (Plantaginaceae)
Authors: Lankinen Åsa , Madjidian Josefin A. , Andersson Stefan
Published: September 2016

Relatively few studies have investigated how geography, environmental factors, and genetics affect floral trait variation. We used mixed-mating Collinsia heterophylla Buist to explore variation in a suite of floral traits related to mating system in populations representing four geographic regions of California, USA, and relate this variation to geography, climatic factors, and local site characteristics. We evaluated the environmental vs. genetic trait variability in the greenhouse. Stage of anther–stigma contact correlated positively with temperature, stage of stigma receptivity was negatively associated with vegetation cover, and flower size differed among populations without any clear relation to environmental factors. Greenhouse data indicated heritability for stage of anther–stigma contact, flower size, and time to flowering, and positive correlations between field and greenhouse for stage of stigma receptivity and flower size; however, stage of anther–stigma contact showed a high degree of environmental influence. Stage of anther–stigma contact covaried positively with stage of stigma receptivity and flower size across maternal families, indicating genetic correlations between traits. In conclusion, phenotypic floral variation within mixed-mating C. heterophylla is mostly determined by a genetic component. Geography, environment, and genetics affect traits differently, suggesting that ecological and evolutionary processes contribute to shaping variability in mating system-related traits.
Araucarian leaves and cone scales from the Loreto Formation of Río de Las Minas, Magellan Region, Chile
Authors: Ohsawa Takeshi A. , Yabe Atsushi , Yamada Toshihiro , Uemura Kazuhiko , Terada Kazuo , Leppe Marcelo , Hinojosa Luis Felipe , Nishida Harufumi
Published: September 2016

Cone scales and leaves of the Araucariaceae are reported from the Loreto Formation in Río de Las Minas, Punta Arenas, Chile. Two types of cone scales including one new species, Araucarites alatisquamosus are recognized. They are similar to Araucaria section Eutacta. Two types of leaves are assigned to Araucaria nathorstii Dusén, and one new type is distinguished in the specimens from the type locality of A. nathorstii. A narrow leaf type is identical to Dusén’s “Blätter der sterilen Zweige (leaves of sterile shoot)” of A. nathorstii, and a broad leaf type is identical to his “Blätter der fertilen Zweige (leaves of fertile shoot)”. Both types show characters of leaves of section Araucaria as suggested by earlier studies. A smaller leaf type differs from the original description of A. nathorstii, and consists of small appressed leaves with the obtuse apex and stomatal orientation that are the characteristic of the section Eutacta. The occurrence of leaves and cone scales similar to section Eutacta suggest the presence of araucarians close to this section in southernmost South America during the Eocene–early Oligocene, and provide evidence for the wide distribution and diversity of genus Araucaria relatives in South America during the Paleogene.
Assessment of low temperature exposure for design and evaluation of elastomeric bridge bearings and seismic isolators in Canada
Authors: Guay Louis-Piérick , Bouaanani Najib
Published: September 2016

This paper presents key data and relevant analyses assessing low temperature exposure for design and evaluation of elastomeric bridge bearings and isolators in Canada. A large database of temperature records is processed to investigate the potential for instantaneous thermal stiffening and crystallization. The results mainly show that: (i) temperature conditions at some locations lead to a significant potential for instantaneous stiffening in terms of intensity and frequency; (ii) in warmer locations, thermal stiffening is highly improbable; (iii) the number of consecutive days below a given low temperature is very variable geographically; and (iv) the crystallization testing criteria prescribed in CSA S6-14 can be too conservative. The results are also illustrated using contour maps. Important differences in temperature variation trends between eastern and western Canada are highlighted. The proposed methodology and obtained results constitute efficient tools to determine site-specific temperature conditions for enhanced performance-based design and evaluation of bridges in Canada.
Global regularity for unsteady flow of MHD Sisko fluid in a porous medium
Authors: Rahman S. , Hayat T. , Ahmad B.
Published: September 2016

The aim of the present paper is to establish the global regularity of classical solution for unidirectional flow of magnetohydrodynamic (MHD) Sisko fluid. The fluid is taken between two rigid plates. An incompressible fluid saturates the porous medium. The main interest in this paper is to establish the global regularity of classical solutions when [Formula: see text], [Formula: see text], and [Formula: see text] are sufficiently small. In addition, uniqueness of the classical solution is also verified. Here BMO denotes the homogeneous space of bounded mean oscillations, V is the velocity, u is the x-component of velocity, and [Formula: see text] is the vorticity.
The effects of the overline running model of the high-speed trains on the existing lines
Authors: Qian Yong-Sheng , Zeng Jun-Wei , Zhang Xiao-Long , Wang Jia-Yuan , Lv Ting-Ting
Published: September 2016

This paper studies the effect on the existing railway which is made by the train with 216 km/h high-speed when running across over the existing railway. The influence on the railway carrying capacity which is made by the transportation organization mode of the existing railway is analyzed under different parking modes of high-speed trains as well. In order to further study the departure intervals of the train, the average speed and the delay of the train, an automata model under these four-aspects is established. The results of the research in this paper could serve as the theoretical references to the newly built high-speed railways.
Bright optical solitons or light bullets for a (3 + 1)-dimensional generalized nonlinear Schrödinger equation with the distributed coefficients
Authors: Yin Hui-Min , Tian Bo , Zhen Hui-Ling , Chai Jun , Wu Xiao-Yu
Published: September 2016

Under investigation in this paper is a (3 + 1)-dimensional generalized nonlinear Schrödinger equation with the distributed coefficients for the spatiotemporal optical solitons or light bullets. Through the symbolic computation and Hirota method, one- and two-soliton solutions are derived. We also present the Bäcklund transformation, through which we derive the soliton solutions. When the gain/loss coefficient is the monotonically decreasing function for the propagation coordinate [Formula: see text], amplitude for the spatiotemporal optical soliton or light bullet decreases along [Formula: see text], while when the gain/loss coefficient is the monotonically increasing function for [Formula: see text], amplitude for the spatiotemporal optical soliton or light bullet increases along [Formula: see text]. Directions of the solitons are different because the signs of imaginary parts of the frequencies are adverse. Based on the two-soliton solutions, elastic and inelastic collisions between the two spatiotemporal optical solitons or light bullets are derived under different conditions presented in the paper.
Automatic Learning of Articulated Skeletons Based on Mean of 3D Joints for Efficient Action Recognition
Authors: Ben Tamou Abdelouahid , Ballihi Lahoucine , Aboutajdine Driss
Published: September 2016

In this paper, we present a new approach for human action recognition using [Formula: see text] skeleton joints recovered from RGB-D cameras. We propose a descriptor based on differences of skeleton joints. This descriptor combines two characteristics including static posture and overall dynamics that encode spatial and temporal aspects. Then, we apply the mean function on these characteristics in order to form the feature vector, used as an input to Random Forest classifier for action classification. The experimental results on both datasets: MSR Action 3D dataset and MSR Daily Activity 3D dataset demonstrate that our approach is efficient and gives promising results compared to state-of-the-art approaches.
On extension theorems and their connection to universal consistency in machine learning
Authors: Christmann Andreas , Dumpert Florian , Xiang Dao-Hong
Published: September 2016

Statistical machine learning plays an important role in modern statistics and computer science. One main goal of statistical machine learning is to provide universally consistent algorithms, i.e. the estimator converges in probability or in some stronger sense to the Bayes risk or to the Bayes decision function. Kernel methods based on minimizing the regularized risk over a reproducing kernel Hilbert space (RKHS) belong to these statistical machine learning methods. It is in general unknown which kernel yields optimal results for a particular data set or for the unknown probability measure. Hence various kernel learning methods were proposed to choose the kernel and therefore also its RKHS in a data adaptive manner. Nevertheless, many practitioners often use the classical Gaussian RBF kernel or certain Sobolev kernels with good success. The goal of this paper is to offer one possible theoretical explanation for this empirical fact.
Error bounds for learning the kernel
Authors: Micchelli Charles A. , Pontil Massimiliano , Wu Qiang , Zhou Ding-Xuan
Published: September 2016

The problem of learning the kernel function has received considerable attention in machine learning. Much of the work has focused on kernel selection criteria, particularly on minimizing a regularized error functional over a prescribed set of kernels. Empirical studies indicate that this approach can enhance statistical performance and is computationally feasible. In this paper, we present a theoretical analysis of its generalization error. We establish for a wide variety of classes of kernels, such as the set of all multivariate Gaussian kernels, that this learning method generalizes well and, when the regularization parameter is appropriately chosen, it is consistent. A central role in our analysis is played by the interaction between the sample error and the approximation error.
An efficient segmentation method based on dynamic graph merging
Authors: Cheng Cun , Zhang Li
Published: September 2016

A novel energy functional based on the Mumford–Shah model is established for performing automatic image segmentation. And in order to optimize the global model using graph-based methods, we develop a localized formula. Then, we propose a merging predicate for determining whether an edge connecting two neighboring pixels or regions merge. The dynamic graph merging (DGM) method is applied based on this merging predicate. That is, those edges with large energy merge and the edges with low energy are remained, such that the energy functional is minimized. Compared with other graph-based segmentation methods, our algorithm based on DGM has an important characteristic which is its ability to produce good segmentation on some complex texture images. Another characteristic is that this segmentation algorithm can avoid the “shrinking bias” problem. We also apply DGM to interactive image segmentation and find the results to be encouraging too.
Global peak alignment for comprehensive two-dimensional gas chromatography mass spectrometry using point matching algorithms
Authors: Deng Beichuan , Kim Seongho , LI Hengguang , Heath Elisabeth , Zhang Xiang
Published: September 2016

Comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC[Formula: see text][Formula: see text][Formula: see text]GC-MS) has been used to analyze multiple samples in a metabolomics study. However, due to some uncontrollable experimental conditions, such as the differences in temperature or pressure, matrix effects on samples and stationary phase degradation, there is always a shift of retention times in the two GC columns between samples. In order to correct the retention time shifts in GC[Formula: see text][Formula: see text][Formula: see text]GC-MS, the peak alignment is a crucial data analysis step to recognize the peaks generated by the same metabolite in different samples. Two approaches have been developed for GC[Formula: see text][Formula: see text][Formula: see text]GC-MS data alignment: profile alignment and peak matching alignment. However, these existing alignment methods are all based on a local alignment, resulting that a peak may not be correctly aligned in a dense chromatographic region where many peaks are present in a small region. False alignment will result in false discovery in the downstream statistical analysis. We, therefore, develop a global comparison-based peak alignment method using point matching algorithm (PMA-PA) for both homogeneous and heterogeneous data. The developed algorithm PMA-PA first extracts feature points (peaks) in the chromatography and then searches globally the matching peaks in the consecutive chromatography by adopting the projection of rigid and nonrigid transformation. PMA-PA is further applied to two real experimental data sets, showing that PMA-PA is a promising peak alignment algorithm for both homogenous and heterogeneous data in terms of [Formula: see text]1 score, although it uses only peak location information.
Classification of the fragrant styles and evaluation of the aromatic quality of flue-cured tobacco leaves by machine-learning methods
Authors: Gu Li , Xue Lichun , Song Qi , Wang Fengji , He Huaqin , Zhang Zhongyi
Published: September 2016

During commercial transactions, the quality of flue-cured tobacco leaves must be characterized efficiently, and the evaluation system should be easily transferable across different traders. However, there are over 3000 chemical compounds in flue-cured tobacco leaves; thus, it is impossible to evaluate the quality of flue-cured tobacco leaves using all the chemical compounds. In this paper, we used Support Vector Machine (SVM) algorithm together with 22 chemical compounds selected by ReliefF-Particle Swarm Optimization (R-PSO) to classify the fragrant style of flue-cured tobacco leaves, where the Accuracy (ACC) and Matthews Correlation Coefficient (MCC) were 90.95% and 0.80, respectively. SVM algorithm combined with 19 chemical compounds selected by R-PSO achieved the best assessment performance of the aromatic quality of tobacco leaves, where the PCC and MSE were 0.594 and 0.263, respectively. Finally, we constructed two online tools to classify the fragrant style and evaluate the aromatic quality of flue-cured tobacco leaf samples. These tools can be accessed at http://bioinformatics.fafu.edu.cn/tobacco .
Ultra-light and strong: The massless harmonic oscillator and its singular path integral
Authors: Modanese Giovanni
Published: September 2016

In classical mechanics, a light particle bound by a strong elastic force just oscillates at high frequency in the region allowed by its initial position and velocity. In quantum mechanics, instead, the ground state of the particle becomes completely de-localized in the limit [Formula: see text]. The harmonic oscillator thus ceases to be a useful microscopic physical model in the limit [Formula: see text], but its Feynman path integral has interesting singularities which make it a prototype of other systems exhibiting a “quantum runaway” from the classical configurations near the minimum of the action. The probability density of the coherent runaway modes can be obtained as the solution of a Fokker–Planck equation associated to the condition [Formula: see text]. This technique can be applied also to other systems, notably to a dimensional reduction of the Einstein–Hilbert action.
Dirac equation in four time and four space dimensions
Authors: Nieto J. A. , Espinoza M.
Published: September 2016

The Dirac equation in four time and four space dimensions (or ([Formula: see text])-dimensions) is considered. Step by step, we show that such an equation admits Majorana and Weyl solutions. In order to obtain the Majorana or Weyl spinors, we used a method based on the construction of Clifford algebra in terms of [Formula: see text]-matrices. We argue that our approach can be useful in supergravity, superstrings and qubit theory.
On compatibility between isogenies and polarizations of abelian varieties
Authors: Orr Martin
Published: September 2016

We discuss the notion of polarized isogenies of abelian varieties, that is, isogenies which are compatible with given principal polarizations. This is motivated by problems of unlikely intersections in Shimura varieties. Our aim is to show that certain questions about polarized isogenies can be reduced to questions about unpolarized isogenies or vice versa. Our main theorem concerns abelian varieties [Formula: see text] which are isogenous to a fixed abelian variety [Formula: see text]. It establishes the existence of a polarized isogeny [Formula: see text] whose degree is polynomially bounded in [Formula: see text], if there exist both an unpolarized isogeny [Formula: see text] of degree [Formula: see text] and a polarized isogeny [Formula: see text] of unknown degree. As a further result, we prove that given any two principally polarized abelian varieties related by an unpolarized isogeny, there exists a polarized isogeny between their fourth powers. The proofs of both theorems involve calculations in the endomorphism algebras of the abelian varieties, using the Albert classification of these endomorphism algebras and the classification of Hermitian forms over division algebras.
On numbers n dividing the nth term of a Lucas sequence
Authors: Sanna Carlo
Published: September 2016

We prove that if [Formula: see text] is a Lucas sequence satisfying some mild hypotheses, then the number of positive integers [Formula: see text] does not exceed [Formula: see text] and such that [Formula: see text] divides [Formula: see text] is less than [Formula: see text] as [Formula: see text]. This generalizes a result of Luca and Tron about the positive integers [Formula: see text] dividing the [Formula: see text]th Fibonacci number, and improve a previous upper bound due to Alba González, Luca, Pomerance and Shparlinski.
Quadratic nonresidues below the Burgess bound
Authors: Banks William D. , Guo Victor Z.
Published: September 2016

For any odd prime number [Formula: see text], let [Formula: see text] be the Legendre symbol, and let [Formula: see text] be the sequence of positive nonresidues modulo [Formula: see text], i.e. [Formula: see text] for each [Formula: see text]. In 1957, Burgess showed that the upper bound [Formula: see text] holds for any fixed [Formula: see text]. In this paper, we prove that the stronger bound [Formula: see text] holds for all odd primes [Formula: see text] provided that [Formula: see text] where the implied constants are absolute. For fixed [Formula: see text], we also show that there is a number [Formula: see text] such that for all odd primes [Formula: see text], there are [Formula: see text] natural numbers [Formula: see text] with [Formula: see text] provided that [Formula: see text]
High-Purity Amino-Functionalized Graphene Quantum Dots Derived from Graphene Hydrogel
Authors: Jin Yinhua , Qin Hongyi , Kim Jang Ah , Kim Sun-Young , Kim Hyeong-U , Lim Yong Taik , Kim Taesung , Kulkarni Atul , Kim Dongbin
Published: September 2016

The unique properties of graphene quantum dots (GQDs) make them interesting candidate materials for innovative applications. Herein, we report a facile method to synthesize amino-functionalized graphene quantum dots (AF-GQDs) by a hydrothermal reaction. Graphene oxide (GO) was synthesized by Hummer’s method where ultra-small GO sheets were obtained by a prolonged oxidation process followed by sonication using an ultrasonic probe. Subsequently, graphene hydrogel (GH) was also obtained by a hydrothermal synthesis method. Proper care was taken during synthesis to avoid contamination from water soluble impurities, which are present in the precursor, GO solution. Following the treatment of GH in ammonia, ultra-small amino-functionalized graphene fragments (AF-GQDs) were formed, which detached from the GH to eventually disperse evenly in the water without agglomerating. This modified synthesis process enables the formation of high-purity AF-GQDs (99.14%) while avoiding time-consuming synthesis procedures. Our finding shows that AF-GQDs with sizes less than 5[Formula: see text]nm were well dispersed. A strong photoluminescence (PL) emission at [Formula: see text]410[Formula: see text]nm with 10% PL quantum yield was also observed. These AF-GQDs can be used in many bio applications in view of their low cytotoxicity and strong fluorescence that can be applied to cell imaging.
Synthesis and Excellent Microwave Absorption Properties of ZnO/Fe3O4/MWCNTs Composites
Authors: Wang Lei , Xing Honglong , Liu Zhenfeng , Shen Ziyao , Sun Xiang , Xu Guocai
Published: September 2016

ZnO nanocrystals were introduced into Fe3O4/MWCNTs composites to improve the impedance matching and electromagnetic (EM) wave attenuation of the system. The as-synthesized ZnO/Fe3O4/MWCNTs composites were characterized by X-ray diffraction, vibrating sample magnetometer, field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy. SEM and TEM images showed that Fe3O4 microspheres 100–200[Formula: see text]nm in size connected MWCNTs. Analysis of EM parameters revealed that the impedance matching of the ZnO/Fe3O4/MWCNTs composites was considerably improved after ZnO nanocrystals were introduced. The ZnO/Fe3O4/MWCNTs composites exhibited a highly efficient microwave absorption (MA) capacity within the tested frequency range of 2–18[Formula: see text]GHz. The optimal reflection loss of EM waves was [Formula: see text][Formula: see text]dB at 6.08[Formula: see text]GHz with an absorber thickness of 3.5[Formula: see text]mm. The excellent MA properties of the composites could be attributed to the improved impedance matching, interfacial polarization, and combined effects of dielectric and magnetic losses.
On classification of pomonoids by properties of generators
Authors: Irannezhad Setareh , Madanshekaf Ali
Published: September 2016

In this paper, we attempt to collect the knowledge on generators in the category Pos-[Formula: see text] and to apply this to proceed on the questions of homological classification of ordered monoids, that is results of the type: all generators in the category Pos-[Formula: see text], have a flatness property if and only if [Formula: see text] has a certain property.
Ultra-Low-Energy Electric Field-Induced Magnetization Switching in Multiferroic Heterostructures
Authors: Roy Kuntal
Published: September 2016

Electric field-induced magnetization switching in multiferroics is intriguing for both fundamental studies and potential technological applications. Here, we review the recent developments on electric field-induced magnetization switching in multiferroic heterostructures. Particularly, we study the dynamics of magnetization switching between the two stable states in a shape-anisotropic single-domain nanomagnet using stochastic Landau–Lifshitz–Gilbert (LLG) equation in the presence of thermal fluctuations. For magnetostrictive nanomagnets in strain-coupled multiferroic composites, such study of magnetization dynamics, contrary to steady-state scenario, revealed intriguing new phenomena on binary switching mechanism. While the traditional method of binary switching requires to tilt the potential profile to the desired state of switching, we show that no such tilting is necessary to switch successfully since the magnetization’s excursion out of magnet’s plane can generate a built-in asymmetry during switching. We also study the switching dynamics in multiferroic heterostructures having magnetoelectric coupling at the interface and magnetic exchange coupling that can facilitate to maintain the direction of switching with the polarity of the applied electric field. We calculate the performance metrics like switching delay and energy dissipation during switching while simulating LLG dynamics. The performance metrics turn out to be very encouraging for potential technological applications.
Intuitive Control Strategies for Teleoperation of Active Catheters in Endovascular Surgery
Authors: Devreker Alain , Tran Phuong Toan , Rosa Benoît , De Praetere Herbert , Häni Nicolai , Famaey Nele , Šeatović Dejan , Herijgers Paul , Sloten Jos Vander , Reynaerts Dominiek , Poorten Emmanuel Vander
Published: September 2016

Cardiovascular surgeons increasingly resort to catheter-based diagnostic and therapeutic interventions because of their limited invasiveness. Although, these approaches allow treatment of patients considered unfit for conventional open surgery, exposure to radiation and high procedural complexity could lead to complications. These factors motivated the introduction of robotic technology offering more dexterous catheters, enhanced visualization and opening new possibilities in terms of guidance and coordinated control. In addition to improvements of patient outcome, through teleoperated catheter control radiation exposure of surgeons can be reduced. In order to limit surgical workload, intuitive mappings between joystick input and resulting catheter motion are essential. This paper presents and compares two proposed mappings and investigates the benefits of additional visual guidance. The comparison is based on data gathered during an experimental campaign involving 14 novices and three surgeons. The participants were asked to perform an endovascular task in a virtual reality simulator presented in the first part of this paper. Statistical results show significant superiority of one mapping with respect to the other and a significant improvement of performance thanks to additional visual guidance. Future work will focus on translating the results to a physical setup for surgical validation, also the learning effect will be analyzed more in-depth.
Weight loss following diet-induced obesity does not alter colon tumorigenesis in the AOM mouse model
Authors: Velázquez Kandy T. , Enos Reilly T. , Carson Meredith S. , Cranford Taryn L. , Bader Jackie E. , Chatzistamou Ioulia , Singh Udai P. , Nagarkatti Prakash S. , Nagarkatti Mitzi , Davis J. Mark , Carson James A. , Murphy E. Angela
Published: September 2016

Obesity presents a significant public health concern given its association with increased cancer incidence, unfavorable prognosis, and metastasis. However, there is very little literature on the effects of weight loss, following obesity, on risk for colon cancer or liver cancer. Therefore, we sought to study whether intentional weight loss through diet manipulation was capable of mitigating colon and liver cancer in mice. We fed mice with a high-fat diet (HFD) comprised of 47% carbohydrates, 40% fat, and 13% protein for 20 wk to mimic human obesity. Subsequently, azoxymethane (AOM) was used to promote colon and liver carcinogenesis. A subset of obese mice was then switched to a low-fat diet (LFD) containing 67.5% carbohydrate, 12.2% fat, and 20% protein to promote intentional weight loss. Body weight loss and excess fat reduction did not protect mice from colon cancer progression and liver dysplastic lesion in the AOM-chemical-cancer model even though these mice had improved blood glucose and leptin levels. Intentional weight loss in AOM-treated mice actually produced histological changes that resemble dysplastic alterations in the liver and presented a higher percentage of F4/80+CD206+ macrophages and activated T cells (CD4+CD69+) in the spleen and lymph nodes, respectively. In addition, the liver of AOM-treated mice exposed to a HFD during the entire period of the experiment exhibited a marked increase in proliferation and pNF-κB activation. Altogether, these data suggest that intentional weight loss following chemical-induced carcinogenesis does not affect colon tumorigenesis but may in fact negatively impact liver repair mechanisms.