Efficient mining of top-k breaker emerging subgraph patterns from graph datasets

This paper introduces a new type of discriminative subgraph pattern called breaker emerging subgraph pattern by introducing three constraints and two new concepts: base and breaker. A breaker emerging sub-graph pattern consists of three subpatterns: a con-strained emerging subgraph pattern, a set of bases and a set of breakers. An efficient approach is pro-posed for the discovery of top-k breaker emerging sub-graph patterns from graph datasets. Experimental re-sults show that the approach is capable of efficiently discovering top-k breaker emerging subgraph patterns from given datasets, is more efficient than two previ-ous methods for mining discriminative subgraph pat-terns. The discovered top-k breaker emerging sub-graph patterns are more informative, more discrim-inative, more accurate and more compact than the minimal distinguishing subgraph patterns. The top-k breaker emerging patterns are more useful for sub-structure analysis, such as molecular fragment analy-sis. © 2009, Australian Computer Society, Inc.

Efficacy of Cognitive Processes in Young People with High-Functioning Autism Spectrum Disorder Using a Novel Visual Information-Processing Task

Autism spectrum disorders (ASD) are characterised by a unique pattern of preserved abilities and deficits within and across cognitive domains. The Complex Information Processing Theory proposes this pattern reflects an altered capacity to respond to cognitive demands. This study compared how complexity induced by time constraints on processing affect cognitive function in individuals with ASD and typically-developing individuals. On a visual information-processing task, the Subtle Cognitive Impairment Test, both groups exhibited sensitivity to time-constraints. Further, 65 % of individuals with ASD demonstrated deficits in processing efficiency, possibly attributable to the effects of age and clinical comorbidities, like attention deficit hyperactivity disorder. These findings suggest that for some ASD individuals there are significant impairments in processing efficiency, which may have implications for education and interventions. © 2014 Springer Science+Business Media New York.

Are urinary porphyrins a valid diagnostic biomarker of autism spectrum disorder?

A fundamental challenge to the timely diagnosis of Autism Spectrum Disorder (ASD) is the reliance on the observation of a set of aberrant behavior. Consequently, the diagnostic process requires that the child reach an age where the behaviors would typically be exhibited. The identification of a reliable biological marker (biomarker) could be of considerable benefit to the diagnostic process. As a diagnostic biomarker, porphyrins present an attractive prospect as previous studies have reported consistent findings of children with ASD showing significant elevations in porphyrin levels in contrast to controls. Furthermore, there is some evidence that ASD severity may be associated with porphyrins, which would be a valuable characteristic of any ASD biomarker. Importantly, for practical use, porphyrins can be tested non-invasively via a sample of urine. The present study sought to investigate whether porphyrin profiles can reliably be used to (a) differentiate ASD cases from healthy controls; and (b) predict ASD severity. The study compared the porphyrin levels of three groups of children aged 2-6 years: Group 1-children diagnosed with ASD (n = 70); Group 2-healthy, normally developing siblings of children diagnosed with ASD (n = 36); and Group 3-healthy, normally developing children with no known blood relative diagnosed with ASD (n = 54). The results of logistic regression analyses failed to find support for the hypotheses that porphyrin levels could be used as a valid tool to detect ASD cases or predict severity. Autism Res 2014, 7: 535-542. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

Attention and basic literacy and numeracy in children with Autism Spectrum Disorder: a one-year follow-up study

Little is known about the link between Executive Functioning (EF) and academic performance in children with Autism Spectrum Disorder (ASD) and how such links develop over time. This study examined word reading, basic mathematics, attention switching, sustained attention and their development. Two age, gender and perceptual IQ matched groups of cognitively able 7-12 year olds (ASD N = 40; typical developing [TYP] N = 40) were assessed at baseline and one year later, completing Word Reading and Numerical Operations tests and computerized tasks tapping attention switching and sustained attention. Children with ASD had similar word reading and numerical operations performance and similar development of these skills relative to TYP children. A delay in attention switching but similar development was found in children with ASD relative to TYP children. The EF tasks were correlated with reading and mathematics in ASD children only, however, in regression analyses these factors were not significant predictors of Time 2 reading and mathematics after accounting for Time 1 reading and mathematics scores. These findings indicate similar word reading and mathematics development but atypical attention profiles in cognitively able children with ASD. Implications for educators are discussed.

On the definition of an kinematic hardening effect graph for sheet metal forming process simulations

The objective of this work is to develop a kinematic hardening effect graph (KHEG) which can be used to evaluate the effect of kinematic hardening on the model accuracy of numerical sheet metal forming simulations and this without the need of complex material characterisation. The virtual manufacturing process design and optimisation depends on the accuracy of the constitutive models used to represent material behaviour. Under reverse strain paths the Bauschinger effect phenomenon is modelled using kinematic hardening models. However, due to the complexity of the experimental testing required to characterise this phenomenon in this work the KHEG is presented as an indicator to evaluate the potential benefit of carrying out these tests. The tool is validated with the classic three point bending process and the U-channel width drawbead process. In the same way, the capability of the KHEG to identify effects in forming processes that do not include forming strain reversals is identified.

Identifying affinity classes of inorganic materials binding sequences via a graph-based model

Rapid advances in bionanotechnology have recently generated growing interest in identifying peptides that bind to inorganic materials and classifying them based on their inorganic material affinities. However, there are some distinct characteristics of inorganic materials binding sequence data that limit the performance of many widely-used classification methods when applied to this problem. In this paper, we propose a novel framework to predict the affinity classes of peptide sequences with respect to an associated inorganic material. We first generate a large set of simulated peptide sequences based on an amino acid transition matrix tailored for the specific inorganic material. Then the probability of test sequences belonging to a specific affinity class is calculated by minimizing an objective function. In addition, the objective function is minimized through iterative propagation of probability estimates among sequences and sequence clusters. Results of computational experiments on two real inorganic material binding sequence data sets show that the proposed framework is highly effective for identifying the affinity classes of inorganic material binding sequences. Moreover, the experiments on the structural classification of proteins (SCOP) data set shows that the proposed framework is general and can be applied to traditional protein sequences.

Observable essential fatty acid deficiency markers and autism spectrum disorder

Autism Spectrum Disorder (ASD) has been associated with essential fatty acid (EFA) deficiencies, with some researchers theorising that dysregulation of phospholipid metabolism may form part of the biological basis for ASD. This pilot study compared observable signs of fatty acid status of 19 children with an ASD diagnosis to 23 of their typically developing siblings. A pregnancy, birth and breastfeeding history was also obtained from their parents, which included a measure of infant intake of fatty acid rich colostrum immediately post-partum. When considered within their family group, those infants not breastfed (with colostrum) within the first hour of life and who had a history of fatty acid deficiency symptoms were more likely to have an ASD diagnosis. Other variables such as formula use, duration of breastfeeding, gestational age and Apgar scores were not associated with group membership. The results of this study are consistent with previous research showing a relationship between fatty acid metabolism, breastfeeding and ASD such that early infant feeding practices and the influence this has on the fatty acid metabolism of the child may be a risk factor for ASD.

An analytical model for optimal spectrum leasing under constraints of quality of service in CRNs

Cognitive radio improves spectrum efficiency and mitigates spectrum scarcity by allowing cognitive users to opportunistically access idle chunks of the spectrum owned by licensed users. In long-term spectrum leasing markets, secondary network operators make a decision about how much spectrum is optimal to fulfill their users' data transmission requirements. We study this optimization problem in multiple channel scenarios. Under the constrains of expected user admission rate and quality of service, we model the secondary network into a dynamic data transportation system. In this system, the spectrum accesses of both primary users and secondary users are in accordance with stochastic processes, respectively. The main metrics of quality of service we are concerned with include user admission rate, average transmission delay and stability of the delay. To quantify the relationship between spectrum provisioning and quality of service, we propose an approximate analytical model. We use the model to estimate the lower and upper bounds of the optimal amount of the spectrum. The distance between the bounds is relatively narrow. In addition, we design a simple algorithm to compute the optimum by using the bounds. We conduct numerical simulations on a slotted multiple channel dynamic spectrum access network model. Simulation results demonstrate the preciseness of the proposed model. Our work sheds light on the design of game and auction based dynamic spectrum sharing mechanisms in cognitive radio networks.

The effects of a course of intranasal oxytocin on social behaviors in youth diagnosed with autism spectrum disorders: A randomized controlled trial

Background There is increasing interest in oxytocin as a therapeutic to treat social deficits in autism spectrum disorders (ASD). The aim of this study was to investigate the efficacy of a course of oxytocin nasal spray to improve social behavior in youth with ASD. Methods In a double-blind, placebo-controlled trial across two Australian university sites between February 2009 and January 2012, 50 male participants aged between 12 and 18 years, with Autistic or Asperger's Disorder, were randomized to receive either oxytocin (n = 26) or placebo (n = 24) nasal sprays (either 18 or 24 International Units), administered twice-daily for 8 weeks. Participants were assessed at baseline, after 4- and 8-weeks of treatment, and at 3-month follow-up. Primary outcomes were change in total scores on the caregiver-completed Social Responsiveness Scale and clinician-ratings on the Clinical Global Impressions-Improvement scale. Secondary assessments included caregiver reports of repetitive and other developmental behaviors and social cognition. Clinical trial registration: Australian New Zealand Clinical Trials Registry www.anzctr.org.au ACTRN12609000513213. Results Participants who received oxytocin showed no benefit following treatment on primary or secondary outcomes. However, caregivers who believed their children received oxytocin reported greater improvements compared to caregivers who believed their child received placebo. Nasal sprays were well tolerated and there was no evidence of increased side effects resulting from oxytocin administration. Conclusions This is the first evaluation of the efficacy for a course of oxytocin treatment for youth with ASD. Although results did not suggest clinical efficacy, further research is needed to explore alternative delivery methods, earlier age of intervention, and the influence of caregiver expectation on treatment response.

The efficacy of a brief behavioral sleep intervention in school-aged children with ADHD and comorbid autism spectrum disorder

Sleep problems are common in children with autism spectrum disorders (ASD) and ADHD and impact adversely on child and parent well-being. The study evaluated the efficacy of a brief behavioral sleep intervention in children with comorbid ADHD-ASD.