Uneven Profile Research Articles

Early fault detection of gas turbine hot components under different ambient and operating conditions

Failure of hot components in gas turbines often causes catastrophic results. Early fault detection can prevent serious incidents and improve the availability. A novel early fault detection method of hot components is proposed in this article. Exhaust gas temperature is usually used as the indicator to detect the fault in the hot components, which is measured by several exhaust thermocouples with uniform distribution at the turbine exhaust section. The healthy hot components cause uniform exhaust gas temperature (EGT) profile, whereas the hot component faults could cause the uneven EGT profile. However, the temperature differences between different thermocouple readings are also affected by different ambient and operating conditions, and it sometimes has a greater influence on EGT than the faults. In this article, an accurate EGT model is presented to eliminate the influence of different ambient and operating conditions on EGT. Especially, the EGT profile swirl under different ambient and operating conditions is also included by considering the information of the thermocouples’ spatial correlations and the EGT profile swirl angle. Based on the developed EGT model, the detection performance of early fault detection of hot components in gas turbine is improved. The accuracy and effectiveness of the developed early fault detection method are evaluated by the real-world gas turbine data.

Can National Tests from the Last Year of Compulsory School Be Used to Obtain More Detailed Information about Academic Performance in Children Treated for Brain Tumours? A Nationwide, Population-Based Study from Sweden.

Simple SummaryChildren treated for brain tumours often suffer from late-appearing complications, including impaired cognitive performance. In this study, 475 Swedish children diagnosed with a brain tumour before their 15th birthday and 2197 matched controls were included. Data from compulsory national tests performed school year nine in the first foreign language English, the mother tongue Swedish and mathematics were analysed. These tests offered more detailed information on academic strengths and weaknesses than the final grades, as different skill sets were assessed. Cases performed worse than controls in English tests than in Swedish and mathematics tests, and they may have performed better in oral than written tasks. There were larger differences between girls treated for brain tumours and their female controls than between boys treated for brain tumours and their male controls. National tests may be useful to complement neuropsychological follow-ups. Characterising these shortcomings is essential to provide appropriate support and prevent social isolation. Children treated for brain tumours often have late-appearing complications that may affect their school performance. Uneven skill profiles may help reveal late complications that can be compensated for but otherwise remain undetected. We investigated Swedish national school tests of oral, reading and writing skills in the first foreign language (English), the mother tongue (Swedish) and mathematics. Data were obtained from The Swedish Childhood Cancer Registry and Statistics Sweden. The results from 475 children diagnosed with a brain tumour before their 15th birthday and 2197 matched controls showed that children treated for brain tumours evinced more difficulties with national tests than controls in almost all subtests, especially in the subject English, and that they may perform better on oral than written tasks. There were larger differences between female cases and controls than between male cases and controls; age at diagnosis played a significant role for some subtests, whereas tumour grade did not. Missing information from national tests proved to be a strong predictor of poor academic performance. Our results show that regular educational follow-ups, as a complement to neuropsychological follow-ups, are important for all children treated for brain tumours, regardless of sex, age at diagnosis or tumour grade.

P2 Receptors in Cardiac Myocyte Pathophysiology and Mechanotransduction.

ATP is a major energy source in the mammalian cells, but it is an extracellular chemical messenger acting on P2 purinergic receptors. A line of evidence has shown that ATP is released from many different types of cells including neurons, endothelial cells, and muscle cells. In this review, we described the distribution of P2 receptor subtypes in the cardiac cells and their physiological and pathological roles in the heart. So far, the effects of external application of ATP or its analogues, and those of UTP on cardiac contractility and rhythm have been reported. In addition, specific genetic alterations and pharmacological agonists and antagonists have been adopted to discover specific roles of P2 receptor subtypes including P2X4-, P2X7-, P2Y2- and P2Y6-receptors in cardiac cells under physiological and pathological conditions. Accumulated data suggest that P2X4 receptors may play a beneficial role in cardiac muscle function, and that P2Y2- and P2Y6-receptors can induce cardiac fibrosis. Recent evidence further demonstrates P2Y1 receptor and P2X4 receptor as important mechanical signaling molecules to alter membrane potential and Ca2+ signaling in atrial myocytes and their uneven expression profile between right and left atrium.

A Tutorial on Modeling and Analysis of Cascading Failure in Future Power Grids

Cascading failure inevitably emerges in complex power grids that can cause enormous economic losses. Over the past few decades, a great deal of effort has been devoted to failure cascade modeling, with the aim of understanding and preventing this complex process. Significant achievements include reproducing the uneven cascade propagation profiles and the power-law distribution of the size of the cascades. At the same time, power grids keep evolving, as driven by technology advancements and practical needs. Wide deployment of information technologies and high penetration of power electronics devices are two important features of future grids. These developments have profound influences on the cascading failure characteristics in future grids, which cannot be well addressed by existing models. In this tutorial, we provide an overview of the state-of-art approaches in studying cascading failure and discuss the strengths and weaknesses of these methods. The explicit changes brought by the new features to the failure cascade processes are analyzed and the limitations of existing approaches are identified. Challenges in the modeling and analysis of cascading failure and possible research directions targeting the future power grids in the next research phase are presented.

The effect of wet spinning conditions on the structure and properties of poly-4-hydroxybutyrate fibers.

Polyhydroxyalkanoates (PHAs), also known as bacterial polyesters, are considered novel polymers for fabricating biomedical products, such as sutures and hernia meshes, because of their biocompatibility and slow biodegradability. Poly-4-hydroxybutyrate (P4HB) is a commonly used PHA that was explored in this study as an absorbable biomaterial for several medical applications, including controlled drug delivery. Currently, P4HB is melt spun and drawn into filaments at high processing temperatures (~200°C), precluding the incorporation of thermally sensitive drugs within the polymer during melt spinning. Post-spinning drug incorporation can potentially cause nonuniform drug absorption that leads to an uneven release profile. This raises the need for a low temperature spinning process for these polymers. Until now, there has been no defined procedure to produce P4HB fibers through a low temperature solution spinning process. This study focuses on determining suitable wet spinning conditions to form continuous P4HB fibers. After several preliminary tests, it was found that a chloroform-based spin dope with 10-15% polymer concentration facilitated the extrusion of continuous stretchable fibers into a coagulation bath containing reagent alcohol. Subsequently, several P4HB fibers were spun with various spin dope concentrations, coagulation bath temperatures, and spin draw ratios to assess their effect on fiber structure and properties.

A Semianalytical Coupling Model between Reservoir and Horizontal Well with Different Well Completions

Although currently, large-scale and multilateral horizontal wells are an important way to improve the oil recovery in the unconventional reservoirs, the flow behavior of fluid from the reservoir into the horizontal wellbore becomes more challenged compared to the single small-scale horizontal well. One of the main challenges is that pressure loss from the well completion section and wellbore cannot be ignored in the coupling process between the reservoir and the horizontal well. In this paper, a new method is presented to solve the coupling flow between the reservoir and the horizontal well with different well completions. The new coupling model is compared with Ouyang’s model (1998) and Penmatcha’s model (1997), and the predicted data are consistent with each other at both early and late times. Meanwhile, four different cases have been proposed to verify the application of the new coupling model with different well completions, and the results indicate that the uneven inflow profile can be effectively alleviated via reasonable completion parameters and different well completions. Based on two types of flow-node units, it can quickly model and solve the coupling problem between the reservoir and the horizontal well with complex completion cases. It can also depict the inflow profile of the horizontal well with different well completions, which is conducive to understand the coupling process. The new coupling model can provide theoretical support for further optimization of completion parameters and well completions and finally improve oil recovery.

A Developmental Profile of Children With Autism Spectrum Disorder in China Using the Griffiths Mental Development Scales.

The purpose of this study was to profile the mental development of children aged 18 to 96 months with autism spectrum disorder (ASD) using the Chinese version of the Griffiths Mental Development Scales (GMDS), and to explore the relationships between developmental levels and ASD severity, the sex of the child and the age of ASD diagnosis. Children with ASD (n = 398; 337 boys, 61 girls) were recruited and ASD severity evaluated using the Autism Behavior Checklist and the Childhood Autism Rating Scale, while the GMDS was used to evaluate the children’s mental development. Study participants were divided into groups according to GMDS general and subscale quotients, ASD severity, sex, and age. The majority of groups divided according to the GMDS quotients exhibited an unbalanced distribution in respect of the six domains of the GMDS and there were significant differences within the six subscale quotients. Autism severity, sex and age had significant effects on the overall level of development of autistic children. The quotients recorded for the children with more severe ASD were significantly lower than those for the children with less severe ASD. A markedly higher proportion of developmental delay was recorded for girls than boys in relation to the performance subscale. The locomotor quotient decreased in line with age at diagnosis, while autism severity and age had significant effects on the general and subscale quotients and sex had a significant effect on performance quotient. Children with ASD exhibit an uneven cognitive development profile, and their overall developmental levels are affected by autism severity, sex and age. Specific cognitive domains differ according to sex in children with ASD. Locomotor skills tend to decrease according to the age at diagnosis for autistic children aged 18 to 84 months. Autism severity and age are also associated with the level of functioning in different cognitive areas. These findings contribute to define the cognitive developmental profiles of children with ASD.

Pragmatic abilities of high-functioning Greek-speaking children with autism

This paper reports on the findings of the pragmatic abilities of Greek-speaking children with autism spectrum disorders (ASD). Twenty high functioning children with ASD and their typically developing age and vocabulary controls were administered a pragmatics task in the context of a larger study targeting the grammar of Greek-speaking children withautism. The task was based on the Diagnostic Evaluation of Language Variation (DELV) and assessed the children’s abilities in communicative role taking, narrative, and question asking. The children with ASDshowed an uneven profile in their pragmatic abilities. The two groups did not differ in communicative role taking and question asking. However, the children with ASD had difficulties on the narrative task, and morespecifically, on the items assessing reference contrast and temporal links. Yet, they performed similarly on the mental state representations and the false beliefs items. Despite their good performance on mental states and false beliefs, the ASD children’s lower performance on reference contrast can be interpreted via Theory of Mind deficits if we assume that the former involve an additional level of complexity; namely, quantifying the amount of information available to the listener. Lower performance on temporal links is in line with the ASD children’s attested difficulties in organizing events into a coherent gist. Their overall profile, and, in particular, the dissociation between the different sections of the task, does not support single deficit accounts. It rather indicates that the deficits of individuals with ASD stem from distinct deficits in core cognitive processes (Happé & Frith, 2006).

Dynamic train-track interactions over railway track stiffness transition zones using baseplate fastening systems

In railway industry, significant attention has been spent to solve stiffness transition zone problems since the railway tracks at these zones, especially at the transition between bridge and embankment, are prone to the significant degradation and they need extra maintenance activities and cost to ensure the safety and comfort of passengers. A variety of applications to solve the transition zone problems have been widely investigated. However, never has the application of baseplate fastening systems to fix the transition zone problem been fully investigated. The study proposed herein is the world’s first investigation to fill the knowledge gap by using numerical models to investigate the effect of baseplate pad stiffness and baseplate weight on the dynamic behaviours of the transition zone between slab track and ballasted track. The numerical models have been simulated using LS-DYNA software and validated by comparing with field measurements and other simulation results. The obtained results present that soft baseplate pads can intensify the rail displacements and increase an uneven track profile at transition zone. The results also show that the effect of baseplate weight play a slight role in reducing the differential settlement. The 400 MN/m/m2 pad stiffness provides the best solution as the slab track stiffness can be equalised to the stiffness of ballasted track. Overall, the optimal stiffness of baseplate can significantly reduce the differential settlement leading to reduce track degradation. However, the uses of heavier baseplates and softer baseplate pads together may cause negative effect by increasing the rail displacements leading to higher differential settlements. Hence, baseplate fastening systems should be carefully selected to maximise the benefit of baseplate fastening systems. The new insights will help track engineers to make an appropriate decision on the design and usage of baseplate fastening systems at the stiffness transition zone to mitigate the risk of accelerated track degradation.

Study on an Energy-Harvesting Magnetorheological Damper System in Parallel Configuration for Lightweight Battery-Operated Automobiles

Suspension dampers are extremely critical for modern automobiles for absorbing vibrational energy while in operation. For years now, the viscous passive damper has been dominant. However, there is a constant need to improve and revolutionize the damping technology to adapt to modern road conditions and for better performance. Controlled shock absorbers capable of adapting to uneven road profiles are required to meet this challenge and enhance the passenger comfort level. Among the many types of modern damping solutions, magnetorheological (MR) dampers have gained prominence, considering their damping force control capability, fast adjustable response, and low energy consumption. Advancements in energy-harvesting technologies allow for the regeneration of a portion of energy dissipated in automotive dampers. While the amount of regenerated energy is often insufficient for regular automobiles, it could prove to be vital to support lightweight battery-operated vehicles. In battery-operated vehicles, this regenerated energy can be used for powering several secondary systems, including lighting, heating, air conditioning, and so on. This research focuses on developing a hybrid smart suspension system that combines the MR damping technology along with an electromagnetic induction (EMI)-based energy-harvesting system for applications in lightweight battery-operated vehicles. The research involves the extensive designing, numerical simulation, fabrication, and testing of the proposed smart suspension system. The development of the proposed damping system would help advance the harvesting of clean energy and enhance the performance and affordability of future battery-operated vehicles.

Numerical modeling and optimization of geometric parameters of a composite bracket

The article presents the development and research results of the stress-strain state of a new composite bracket structural solution. The basic scheme of the invention and its application in hinged facade systems are described. The main feature of the developed design solution is the production of various shapes profiles made of aluminum alloys: a U-shaped profile with a wall thickness that varies along the length and an L-shaped uneven profile. Both parts of the bracket are made of aluminum alloys using extrusion method, which allows producing a profile of different shape on terms of area. The results of numerical modeling and selection of optimal geometric and physical-mechanical characteristics of the developed composite bracket in the software package are presented. The actual loads, impacts and operating conditions are taken into account. Based on the results of numerical studies, it is found out that the developed type of the bearing bracket meets the requirements of strength, rigidity and stability. The additional optimization allows reducing the weight of the bracket compared to the original model without significantly reducing the bearing capacity.

Dynamic response of vehicle–bridge–soil system using lumped-parameter models for structure–soil interaction

Prediction of vibrations generated by railway traffic experiences an increasing interest, as new lines are being constructed and planned in many countries. The paper proposes a numerical model to analyse a coupled vehicle–bridge–soil system, taking into account the most important phenomena affecting the structure, while at the same time being comparatively computationally efficient. Such model is useful in the early design phases of a project, when analysing a range of possible configurations or conducting parametric analysis is required.A simplified vehicle model, nonlinear wheel–rail interaction, a bridge structure modelled using the finite-element method and a semi-analytical model for layered soil are all introduced in the model. A pure time-domain solution procedure is used, utilizing lumped-parameter models (LPMs) for the soil–foundation system. Representation of the dynamic stiffness matrix using LPMs is investigated by analysing the cross-coupling between footings and a novel procedure necessary for computationally stable LPMs is introduced and utilized. Further, pure time-domain solution is compared with an iterative mixed-domain solution. Finally, to illustrate the capabilities of the model, analyses are carried out to determine the resulting maximum and minimum excitation limits resulting from wheel–rail interaction on a number of randomly generated uneven track profiles.

Is the Motor Impairment in Attention Deficit Hyperactivity Disorder (ADHD) a Co-Occurring Deficit or a Phenotypic Characteristic?

ObjectivesMotor difficulties are often reported in individuals with attention deficit hyperactivity disorder (ADHD). The aims of this study are to detail the motor profile of children with ADHD and to determine whether the motor impairment present in a large proportion of children with ADHD represents a phenotypic characteristic of ADHD or a co-occurring deficit.MethodsParticipants with ADHD (N = 51; age 8 to 15 years) and typically developing (TD) motor matched control children (N = 75; age 4 to 11 years) completed the largest battery of assessments of motor function that have been used with this population to date, as well as a measure of inhibition as a behavioural measure of ADHD characteristics. Parents/caregivers also completed questionnaires relating to ADHD symptomology and a retrospective report of their child’s motor milestone achievement.ResultsA motor deficit was observed in 47% of our ADHD sample. Few relationships were observed between ADHD core characteristics and motor competence. Furthermore, there was an uneven profile of motor performance across different motor tasks, relative to the TD children. Interestingly, it appears that motor milestone achievement is not delayed in ADHD.ConclusionsOur findings suggest that the motor deficit observed in ADHD is not inherent to ADHD. The motor deficit observed in some children with ADHD does not represent a simple delay in development and is not observed in infancy with respect to reaching motor milestones.

Early manifestation of sleep problems in toddlers with Williams Syndrome using a mixed method longitudinal approach

Children with neurodevelopmental disorders commonly experience sleep problems. Williams Syndrome (WS), a rare genetic disorder characterised by a complex, uneven cognitive profile, is no exception. Compared with children with typical development (TD), school-aged children with WS experience significant sleep disruption: shorter sleep duration, more night wakings, greater bedtime resistance and excessive daytime tiredness. In children with TD, sleep problems impede optimal daytime functioning. In WS, this could compound existing difficulties. Few studies have examined sleep in very young children with WS and little is known about the early emergence of sleep problems in this population. To date, studies have been based on parent-report and no studies have objectively assessed sleep patterns using longitudinal approach in toddlers with WS. Thus, the current study sought to objectively explore sleep patterns in toddlers with WS. Parents of 38 children (13 WS, 25 TD) completed the Brief Infant Screening Questionnaire and the Medical and Demographics Questionnaire and sleep patterns were assessed using actigraphy. Data were collected longitudinally at ages 18, 24 and 30 months. Significant sleep disturbances were present in WS from 18 months old. Sleep duration, as measured by actigraphy, was significantly shorter in WS at all ages and, furthermore, parents of children with WS reported more night wakings, longer settling times and high levels of parental involvement. Crucially, whereas actigraphy showed developmental improvements in sleep quality in TD, no longitudinal changes were found in WS. Findings could be instrumental in working towards instigating appropriate, timely sleep management in this group, thus improving outcomes for children and their families.

Music Affinity and Emotion in Williams Syndrome

Williams syndrome (WS) is a neurodevelopmental genetic disorder. Of interest to cognitive scientists is the uneven cognitive profile that is characteristic of the syndrome. In spite of mild to moderate intellectual disability, a complex pattern of strengths and weaknesses is found in their cognitive abilities. Strengths are seen in linguistic abilities and facial processing whereas weaknesses include visuo-spatial skills and conceptual reasoning abilities. Numerous anecdotes exist regarding musical abilities in individuals with WS. To elaborate on the neuropsychological profile of WS and particularly to better understand the affinity to music in individuals with WS, the present study examined the perception and production of music in this population. Results revealed that overall, individuals with WS were more expressive than typically developing individuals when they were involved with music. This study serves to further characterize this unique social and cognitive profile of individuals with WS, adding an affinity to music as a characteristic of their phenotype.

Оценка эффективности сушильной части машин для выработки санитарно-гигиенических видов бумаги

The paper presents the method for assessment the performance of high-speed Yankee hoods in the production of tissue paper grades and the results of its use in working machine. The following parameters are found applying this method: paper web dryness, air pressure in the wet and dry ends of high-speed convective dryers and temperature of the air spilled out of the hoods. The methodology is based on the measurement of these characteristics during the operation of working equipment with further adjustment of the separate system units. Thermal imaging was carried out during the experiment. It has been found that blowing hot air on the front side of the hood and sucking in the cold air on the drive side leads to uneven moisture profile (measured on the paper machine roll) across the paper web width, a decrease in energy efficiency and the machine capacity. Performance indicator may be, for instance, the spilled air temperature, which on the studied machine is significantly different from the standard value and is 175 °C. The rationality of regular monitoring of air characteristics when changing processing modes is proved. The relevance of the cascade system is substantiated, where not only a direct cascade from the dry end to the wet end is possible, but also there is an opportunity to adjust the humidity of exhaust air by addition/reduction of part of it to/from the dry end. The direct effect of adjusting the humidity of exhaust air in the drying section on reduction of energy costs, as well as the effect of make-up air on the amount of infiltration and the air balance of the system are confirmed. A set of measures implemented within the framework of this methodology makes it possible to achieve energy saving in existing industries. The prospective saving potential of gas is 62 m3/h or 17 % of the current consumption and actual electricity consumption is 6.8 kWh or 4 % for the studied machine. For citation: Prokhorov D.A., Smolin A.S. Performance Assessment of the Drying Section of Machines for the Production of Tissue Paper Grades. Lesnoy Zhurnal[Russian Forestry Journal], 2020, no. 2, pp. 159–168. DOI: 10.37482/0536-1036-2020-2-159-168

Autistic traits and cognitive abilities associated with two molecular causes of Silver-Russell syndrome.

Silver-Russell syndrome is a rare genetic imprinting disorder. Two molecular causes of Silver-Russell syndrome have been identified: loss of methylation on chromosome 11p15 (11p15 LOM) and maternal uniparental disomy for chromosome 7 (matUPD7). Current understanding of the cognitive and behavioral phenotypes associated with these two molecular subtypes is limited. This study aimed to address this gap in the literature. The Social Responsiveness Scale (SRS-2) was used to assess autistic traits in individuals with 11p15 LOM (n = 47) and matUPD7 (n = 32). A subset of participants with 11p15 LOM (n = 18) and matUPD7 (n = 15) completed in-person assessments: the Autism Diagnostic Observation Schedule (ADOS-2) and the British Ability Scales (BAS3). Overall, 37.50% of the matUPD7 group and 10.64% of the 11p15 LOM group scored above the SRS-2 severe clinical cut-off. Based on the ADOS-2, 33.33% of the matUPD7 participants and 11.11% of the 11p15 LOM participants scored above cut-off for autism spectrum/autism. Intellectual ability was significantly lower in the matUPD7 group (M = 79.86) compared with the 11p15 LOM group (M = 98.56). However, there was no evidence of an uneven cognitive profile associated with either group or of an association between autistic traits and intellectual ability. Although both 11p15 LOM and matUPD7 have the same clinical diagnosis of Silver-Russell syndrome, there are some differences in the cognitive and behavioral phenotypes between these two molecular subtypes. This has implications for considering access to services, intervention, and support within these populations, particularly in relation to learning and behavior. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Mathematical development in Williams syndrome: A systematic review

BackgroundThe current systematic review is the first to systematically explore and synthesis research to date on mathematical abilities in Williams syndrome (WS), a rare genetic disorder that results in an uneven cognitive profile. As mathematical development is complex and relies on both domain-specific and domain-general abilities, it is currently not clear what mathematical abilities have been examined in WS and also what the current gaps in this research area are. Methods and proceduresA total of 27 studies across 22 publications were identified through a systematic review search process. ResultsOverall, all mathematical abilities, except for simple counting and subitizing abilities, were reported to be impaired but in line with overall mental-age abilities. However, the literature to date has not established the underlying causes of these mathematical difficulties in WS. Some studies suggested that mathematical abilities in WS follow an atypical developmental pathway with a greater reliance on verbal abilities than in typical development but coupled with impaired understanding of counting and knowledge of the number system more broadly. However, most included studies used different assessments of mathematical skills and there is a lack of studies that have examined more than one particular aspect of mathematical development within the same study. In addition, studies have often included large age ranges and small participant samples, despite the known large individual variability in WS. ConclusionAlthough we know mathematical abilities in WS are impaired, this area is under-researched and there is a lack of longitudinal studies that provide insight into the cognitive mechanisms that underpin mathematical development in WS. Therefore, there is a lack of an evidence-base to inform interventions or educational practice.

A model of grain boundary complexion transitions and grain growth in Yttria-doped alumina

In this work, we present a physically-parameterized microstructure evolution model for the Yttria-doped alumina system. Yttria-doped alumina is a well-known ceramic system which undergoes first-order phase-like transitions at grain boundaries, which can radically alter interface properties. The change in interfacial properties in turn can radically change microstructure outcomes during processing, including the induction of abnormal grain growth modes. In this work, we develop a simulation that evolves alumina microstructure as a function of yttria concentration and temperature. In the window studied, we achieve strong agreement with reviewed experimental results in identifying the windows for large grains, small grains, abnormal grain growth, and complexion transition kinetics (as measured by JMAK analysis). We then apply the model to study and demonstrate how the possible inclusion of second-phase particles or uneven solute distribution profiles will impact microstructure evolution. It is found that particles do not significantly affect abnormal grain growth in the window studied (but do lead to reduced grain size through pinning effects). It is found that even modest amounts of solute inhomogeneity will result in substantial changes in microstructure outcomes, frequently leading to clusters of abnormal grains. This model largely corroborates the expectations and hypotheses made from recent experimental studies in oxide-doped alumina systems. Further, it is found that there exists a peak transition fraction for the system at which abnormal grain size tends to be maximized.

Chapter 10 - Autism spectrum disorder

Autism is a frequent, precocious behavioral constellation of social and communicative atypicalities associated with apparently restricted interests and repetitive behavior and paired with an uneven ability profile. Its definition has constantly broadened in the past 75 years, introducing phenotypes increasingly distant from its initial description, heterogeneous in intelligence and speech level, and associated conditions. When it is unassociated with other conditions, its origin is mostly genetic, transmissible, and favored by frequent polymorphisms with small effects present in the general population. Identified de novo rare mutations with large deleterious effects produce phenotypes only loosely related to nonsyndromic autism. Autism is associated with brain reorganization at multiple levels, and with a variant of typical information processing, i.e., the way humans perceive, memorize, manipulate, and attribute emotional value to available information. Its phenotype evolves over the span of life, with an overall reduction of autistic signs, but it still requires some level of support. There is no treatment for this condition; however, it is compatible with high levels of integration into society.