Toward a Holistic Understanding and Models of Nonphotochemical Quenching Effects on In Vivo Fluorometry of Chlorophyll a in Coastal Waters.

Nonphotochemical quenching (NPQ) is known to depress in vivo fluorescence (IVF) of chlorophyll a (Chla) in aquatic environments, which makes it difficult to interpret the hour-to-hour variations in Chla measured by in situ fluorometers. We hypothesized that ratios between quenched and unquenched IVF are a function of both NPQ and photochemical quenching. In this study, two diatom model species Thalassiosira pseudonana (CCMP1335) and Thalassiosira weissflogii (CCMP1047) incubated under a sinusoidal light:dark cycle were studied; IVF was recorded continuously, and Chla and photo-physiological variables were measured seven times a day. The maximal decline in Chla-specific IVF (IVFB ) attributable to quenching was 50% under the experimental settings. An NPQ and photochemical quenching-based modeling equation exhibited a better match to the measured IVFB than equations representing the sole NPQ effect. Photochemical quenching induced by measuring light beam varied substantially during the day, and the part of the model for this process is excitation intensity-dependent (which is differed between models of in situ fluorometers, implying no straightforward method to correct Chla for all instrument models, instrument-specific parameterization is required). The forms of the IVFB -light relationship are discussed as well. The findings foster a holistic understanding of NPQ effects on in vivo Chla fluorometry.

A pilot study of dialectical behaviour therapy skills training for autistic adults.

BACKGROUND: Autism spectrum disorder (ASD) is a common and lifelong neurodevelopmental disorder with the hallmark features of social impairment and restricted and repetitive patterns of behaviour. Individuals with ASD often experience co-occurring mental health difficulties, some of which may obfuscate the ASD features themselves. Although there is a high need for mental health services for autistic adults, there are surprisingly few evidence-based treatments (EBTs) available; moreover, many mental health practitioners who are well-trained in EBTs shy away from treating autistic individuals due to lack of training in ASD. AIMS: The aim of the current study was to evaluate the feasibility and acceptability of dialectical behaviour therapy skills training (DBT-ST) in a sample of autistic adults without intellectual disability. METHOD: Sixteen adults with ASD were recruited from a treatment waiting list to enrol in this study, which included 24 weeks of DBT-ST delivered in a group setting. Feasibility and acceptability were assessed using retention and attendance data and a participant satisfaction questionnaire. RESULTS: Retention (81.3%) and attendance data (mean 87.5%) provided support for the feasibility of this intervention. Overall satisfaction ratings were high (mean 4.5 out of 5), and participants reported that they felt that DBT-ST would probably be helpful for others with ASD (mean 4.5 out of 5). CONCLUSIONS: The study findings provide preliminary evidence of (1) the feasibility of providing DBT-ST for autistic adults in community-based clinics, and (2) the perceived benefit of DBT-ST for this under-served population. Recommended modifications to the standard DBT-ST materials are discussed.

Profiles of Autonomic Activity in Autism Spectrum Disorder with and without Anxiety.

Both anxiety and autism spectrum disorder (ASD) are associated with atypical physiological activity. Few studies have systematically assessed the resting physiological activity in ASD with co-occurring anxiety disorders. We tested 75 participants divided in four groups: youth with ASD, with (ASD + Anxiety = 22, 6F, 12.29 ± 2.83 years old) and without co-occurring anxiety (ASD Alone = 15, 6F, 11.59 ± 2.85 years old) and compared their physiological profile with that of matched typically developing controls (TDC) with (Anxiety Alone = 16, 6F, 11.24 ± 3.36 years old) and without co-occurring anxiety disorders (TDC = 22, 8F, 11.88 ± 2.88 years old). Results indicated reduced sympathetic and parasympathetic activity at rest in ASD as compared to TDC youth. ASD + Anxiety and Anxiety Alone groups showed different sympathetic, but similar parasympathetic activity. These findings suggest that autonomic profile-based approaches may advance research, diagnosis, and treatment of ASD and anxiety.

Attention-Deficit/Hyperactivity Disorder Symptoms Are Associated With Lower Adaptive Behavior Skills in Children With Autism.

OBJECTIVE: To investigate the predictive power of comorbid attention-deficit/hyperactivity disorder (ADHD) symptoms on adaptive behavior skills in children who have an autism specrum disorder (ASD) diagnosis. METHOD: This case-control study recruited 347 children from specialty clinics, primary care, and the community. Linear regression was used to test whether ADHD Rating Scale, Fourth Edition, scores of autistic children associated with poorer adaptive behavior scores, after controlling for the effects of age, intelligence, sex, and ASD symptom severity. Adaptive behaviors were measured with the Vineland Adaptive Behavior Scales, Second Edition. Subsequent analyses tested this relation in a subset of the ASD sample with subclinical ADHD symptoms (n = 179) and another with teacher ratings (n = 153). Prior relations between age with adaptive behaviors and ADHD symptoms were replicated and age was explored as a moderator. RESULTS: ADHD symptoms predicted poor adaptive behavior scores in the full ASD sample (caregiver ratings, ΔR2 = 0.033-0.119; teacher ratings, ΔR2 = 0.113-0.163) and in the subset with subclinical ADHD symptoms (caregiver ratings, ΔR2= 0.023-0.030; teacher ratings, ΔR2 = 0.097-0.159) after controlling for confounds. Age correlated negatively with ADHD symptoms (r = -0.21) and adaptive behaviors (-0.17 < r < -0.39) in the full ASD sample. Age did not moderate the effect of ADHD symptoms on adaptive behaviors. CONCLUSION: ADHD symptoms predict poorer adaptive behavior for autistic children across settings, even for children with subclinical co-occurring ADHD symptoms. Findings support a Research Domain Criteria framework that behavioral impairments and functional outcome measures exist along a continuum.

Functional Connectivity of Frontoparietal and Salience/Ventral Attention Networks Have Independent Associations With Co-occurring Attention-Deficit/Hyperactivity Disorder Symptoms in Children With Autism.

BACKGROUND: Children with autism spectrum disorder (ASD) and co-occurring attention-deficit/hyperactivity disorder (ADHD) symptoms have worse functional outcomes and treatment response than those without ADHD symptoms. There is limited knowledge of the neurobiology of ADHD symptoms in ASD. Here, we test the hypothesis that aberrant functional connectivity of two large-scale executive brain networks implicated in ADHD-the frontoparietal and salience/ventral attention networks-also play a role in ADHD symptoms in ASD. METHODS: We compared resting-state functional connectivity of the two executive brain networks in children with ASD (n = 77) and typically developing control children (n = 82). These two executive brain networks comprise five subnetworks (three frontoparietal, two salience/ventral attention). After identifying aberrant functional connections among subnetworks, we examined dimensional associations with parent-reported ADHD symptoms. RESULTS: Weaker functional connectivity in ASD was present within and between the frontoparietal and salience/ventral attention subnetworks. Decreased functional connectivity within a single salience/ventral attention subnetwork, as well as between two frontoparietal subnetworks, significantly correlated with ADHD symptoms. Furthermore, follow-up linear regressions demonstrated that the salience/ventral attention and frontoparietal subnetworks explain unique variance in ADHD symptoms. These executive brain network-ADHD symptom relationships remained significant after controlling for ASD symptoms. Finally, specificity was also demonstrated through the use of a control brain network (visual) and a control co-occurring symptom domain (anxiety). CONCLUSIONS: The present findings provide novel evidence that both frontoparietal and salience/ventral attention networks' weaker connectivities are linked to ADHD symptoms in ASD. Moreover, co-occurring ADHD in the context of ASD is a source of meaningful neural heterogeneity in ASD.

Lagging skills contribute to challenging behaviors in children with autism spectrum disorder without intellectual disability.

Many children with autism spectrum disorder display challenging behaviors. These behaviors are not limited to those with cognitive and/or language impairments. The Collaborative and Proactive Solutions framework proposes that challenging behaviors result from an incompatibility between environmental demands and a child's "lagging skills." The primary Collaborative and Proactive Solutions lagging skills-executive function, emotion regulation, language, and social skills-are often areas of weakness for individuals with autism spectrum disorder. The purpose of this study was to evaluate whether these lagging skills are associated with challenging behaviors in youth with autism spectrum disorder without intellectual disability. Parents of 182 youth with autism spectrum disorder (6-15 years) completed measures of their children's challenging behaviors, executive function, language, emotion regulation, and social skills. We tested whether the Collaborative and Proactive Solutions lagging skills predicted challenging behaviors using multiple linear regression. The Collaborative and Proactive Solutions lagging skills explained significant variance in participants' challenging behaviors. The Depression (emotion regulation), Inhibit (executive function), and Sameness (executive function) scales emerged as significant predictors. Impairments in emotion regulation and executive function may contribute substantially to aggressive and oppositional behaviors in school-age youth with autism spectrum disorder without intellectual disability. Treatment for challenging behaviors in this group may consider targeting the incompatibility between environmental demands and a child's lagging skills.

Globally weaker and topologically different: resting-state connectivity in youth with autism.

BACKGROUND: There is a lack of agreement about functional connectivity differences in individuals with autism spectrum disorder (ASD). Studies using absolute strength have found reduced connectivity, while those using relative strength--a measure of system topology--reveal mostly enhanced connectivity. We hypothesized that mixed findings may be driven by the metric of functional connectivity. METHODS: Resting-state echo planar 3 T functional magnetic resonance imaging scans were acquired on a Siemens Verio Scanner from 6 to 17-year-old youth with ASD (n = 81) and a matched typically developing control group (n = 82). All functional time series data were preprocessed using a confound regression procedure that has been previously validated in large-scale developmental datasets. It has also been shown to be highly effective at reducing the influence of motion artifact on connectivity data. We extracted time series data from a 333-node parcellation scheme, which was previously mapped to 13 functional systems. A Pearson's correlation was calculated and transformed to Fisher's z between every pair of nodes to create a weighted 333 × 333 adjacency matrix. Mean absolute functional connectivity strength was the mean Fisher's z of the matrix. Relative functional connectivity was corrected for individual differences in mean absolute functional connectivity (i.e., each connection in the matrix was divided by their mean z), and functional connectivity was evaluated within and across each of the functional networks in the parcellation scheme. RESULTS: Absolute functional connectivity strength was lower in ASD, and lower functional connectivity was correlated with greater ASD symptom severity. Relative functional connectivity was higher for the ASD group in the ventral attention and retrosplenial-temporal systems, with lower cross-system functional connectivity between the ventral attention and somatomotor-mouth systems. Functional connectivity within the ventral attention and retro-splenial systems correlated significantly with ASD symptom severity. CONCLUSIONS: Within a context of globally weaker functional connectivity, youth with ASD have an atypical topology of brain systems that support social perception and communication. This study clarifies the mixed results reported previously and demonstrates that the functional connectivity metric influences the observed direction of functional connectivity differences for individuals with ASD.

Brief report: emotion regulation and respiratory sinus arrhythmia in autism spectrum disorder.

Emotion regulation (ER) may be an important transdiagnostic factor for understanding mental and behavioral health given its association with several psychiatric disorders, including autism spectrum disorder (ASD). However, there is limited research on ER in ASD, particularly using biomarkers such as respiratory sinus arrhythmia (RSA). The aim of the current study was to examine RSA among school-aged children with ASD in relation to symptoms of anxiety, executive functioning, and adaptive socialization skills. Results showed decreased RSA in children with ASD (relative to typically developing controls), reflecting decreased parasympathetic nervous system activity. In addition, decreased RSA was associated with increased symptoms of anxiety and lower socialization skills. These findings emphasize the need for interventions targeting emotional and arousal regulation in ASD.

A multisite study of the clinical diagnosis of different autism spectrum disorders.

CONTEXT: Best-estimate clinical diagnoses of specific autism spectrum disorders (autistic disorder, pervasive developmental disorder-not otherwise specified, and Asperger syndrome) have been used as the diagnostic gold standard, even when information from standardized instruments is available. OBJECTIVE: To determine whether the relationships between behavioral phenotypes and clinical diagnoses of different autism spectrum disorders vary across 12 university-based sites. DESIGN: Multisite observational study collecting clinical phenotype data (diagnostic, developmental, and demographic) for genetic research. Classification trees were used to identify characteristics that predicted diagnosis across and within sites. SETTING: Participants were recruited through 12 university-based autism service providers into a genetic study of autism. PARTICIPANTS: A total of 2102 probands (1814 male probands) between 4 and 18 years of age (mean [SD] age, 8.93 [3.5] years) who met autism spectrum criteria on the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule and who had a clinical diagnosis of an autism spectrum disorder. MAIN OUTCOME MEASURE: Best-estimate clinical diagnoses predicted by standardized scores from diagnostic, cognitive, and behavioral measures. RESULTS: Although distributions of scores on standardized measures were similar across sites, significant site differences emerged in best-estimate clinical diagnoses of specific autism spectrum disorders. Relationships between clinical diagnoses and standardized scores, particularly verbal IQ, language level, and core diagnostic features, varied across sites in weighting of information and cutoffs. CONCLUSIONS: Clinical distinctions among categorical diagnostic subtypes of autism spectrum disorders were not reliable even across sites with well-documented fidelity using standardized diagnostic instruments. Results support the move from existing subgroupings of autism spectrum disorders to dimensional descriptions of core features of social affect and fixated, repetitive behaviors, together with characteristics such as language level and cognitive function.

Deletion 17q12 is a recurrent copy number variant that confers high risk of autism and schizophrenia.

Autism spectrum disorders (ASD) and schizophrenia are neurodevelopmental disorders for which recent evidence indicates an important etiologic role for rare copy number variants (CNVs) and suggests common genetic mechanisms. We performed cytogenomic array analysis in a discovery sample of patients with neurodevelopmental disorders referred for clinical testing. We detected a recurrent 1.4 Mb deletion at 17q12, which harbors HNF1B, the gene responsible for renal cysts and diabetes syndrome (RCAD), in 18/15,749 patients, including several with ASD, but 0/4,519 controls. We identified additional shared phenotypic features among nine patients available for clinical assessment, including macrocephaly, characteristic facial features, renal anomalies, and neurocognitive impairments. In a large follow-up sample, the same deletion was identified in 2/1,182 ASD/neurocognitive impairment and in 4/6,340 schizophrenia patients, but in 0/47,929 controls (corrected p = 7.37 × 10⁻5). These data demonstrate that deletion 17q12 is a recurrent, pathogenic CNV that confers a very high risk for ASD and schizophrenia and show that one or more of the 15 genes in the deleted interval is dosage sensitive and essential for normal brain development and function. In addition, the phenotypic features of patients with this CNV are consistent with a contiguous gene syndrome that extends beyond RCAD, which is caused by HNF1B mutations only.

Transmission and reassortment of avian influenza viruses at the Asian-North American interface.

Twenty avian influenza viruses were isolated from seven wild migratory bird species sampled at St. Lawrence Island, Alaska. We tested predictions based on previous phylogenetic analyses of avian influenza viruses that support spatially dependent trans-hemispheric gene flow and frequent interspecies transmission at a location situated at the Asian-North American interface. Through the application of phylogenetic and genotypic approaches, our data support functional dilution by distance of trans-hemispheric reassortants and interspecific virus transmission. Our study confirms infection of divergent avian taxa with nearly identical avian influenza strains in the wild. Findings also suggest that H16N3 viruses may contain gene segments with unique phylogenetic positions and that further investigation of how host specificity may impact transmission of H13 and H16 viruses is warranted.