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To what extent can particulate random media be characterised using direct wave backscattering from a single receiver/source? Here, in a two-dimensional setting, we show using a machine learning approach that both the particle radius and concentration can be accurately measured when the boundary condition on the particles is of Dirichlet type. Although the methods we introduce could be applied to any particle type. In general backscattering is challenging to interpret for a wide range of particle concentrations, because multiple scattering cannot be ignored, except in the very dilute range. Across the concentration range from 1% to 20% we find that the mean backscattered wave field is sufficient to accurately determine the concentration of particles. However, to accurately determine the particle radius, the second moment, or average intensity, of the backscattering is necessary. We are also able to determine what is the ideal frequency range to measure a broad range of particles sizes. To get rigorous results with supervised machine learning requires a large, highly precise, dataset of backscattered waves from an infinite half-space filled with particles. We are able to create this dataset by introducing a numerical approach which accurately approximates the backscattering from an infinite half-space.

Oxytocin may influence various human behaviors and the connectivity across subcortical and cortical networks. Previous oxytocin studies are male biased and often constrained by task-based inferences. Here, we investigate the impact of oxytocin on resting-state connectivity between subcortical and cortical networks in women. We collected resting-state functional magnetic resonance imaging (fMRI) data on 26 typically developing women 40 min following intranasal oxytocin administration using a double-blind placebo-controlled crossover design. Independent components analysis (ICA) was applied to examine connectivity between networks. An independent analysis of oxytocin receptor (OXTR) gene expression in human subcortical and cortical areas was carried out to determine plausibility of direct oxytocin effects on OXTR. In women, OXTR was highly expressed in striatal and other subcortical regions, but showed modest expression in cortical areas. Oxytocin increased connectivity between corticostriatal circuitry typically involved in reward, emotion, social communication, language and pain processing. This effect was 1.39 standard deviations above the null effect of no difference between oxytocin and placebo. This oxytocin-related effect on corticostriatal connectivity covaried with autistic traits, such that oxytocin-related increase in connectivity was stronger in individuals with higher autistic traits. In sum, oxytocin strengthened corticostriatal connectivity in women, particularly with cortical networks that are involved in social-communicative, motivational and affective processes. This effect may be important for future work on neurological and psychiatric conditions (for example, autism), particularly through highlighting how oxytocin may operate differently for subsets of individuals. 7 e1099 e1099 PT: J

There is a worse prognosis for psychosis and schizophrenia when onset is in childhood or adolescence. However, outcomes are improved with early detection and treatment. Psychotic symptoms can be associated with a variety of disorders including schizophrenia, schizoaffective disorder, drug-induced psychosis, personality disorder, epilepsy and autistic spectrum disorder. Positive symptoms include hallucinations and delusions. Negative symptoms include apathy, lack of drive, poverty of speech, social withdrawal and self-neglect. The DSM IV criteria for schizophrenia include two or more of the following: hallucinations, delusions, disorganised speech, grossly disorganised or catatonic behaviour and negative symptoms. Adults may raise concerns about social withdrawal, bizarre ideas, a change in behaviour or a decline in achievement. Most children and young people with psychotic symptoms will not go on to develop psychosis or schizophrenia. Direct enquiry may be needed to elicit suspected unusual beliefs or hallucinations. To distinguish unusual ideas from delusions the ideas should be tested for fixity. For example by asking: 'Are you sure? Could there be another explanation?' Mood and anxiety symptoms should be explored. The assessment should include a developmental history with particular attention to premorbid functioning. Failure to make expected progress whether personal, social or academic is significant. Better outcomes in terms of symptoms and social function are associated with a shorter duration of untreated psychosis. The detection of psychotic symptoms in primary care therefore warrants an urgent referral to secondary care mental health services for assessment and treatment.