Taylor's law for exponentially growing local populations linked by migration.

We consider the dynamics of a collection of n>1 populations in which each population has its own rate of growth or decay, fixed in continuous time, and migrants may flow from one population to another over a fixed network, at a rate, fixed over time, times the size of the sending population. This model is represented by an ordinary linear differential equation of dimension n with constant coefficients arrayed in an essentially nonnegative matrix. This paper identifies conditions on the parameters of the model (specifically, conditions on the eigenvalues and eigenvectors) under which the variance of the n population sizes at a given time is asymptotically (as time increases) proportional to a power of the mean of the population sizes at that given time. A power-law variance function is known in ecology as Taylor's Law and in physics as fluctuation scaling. Among other results, we show that Taylor's Law holds asymptotically, with variance asymptotically proportional to the mean squared, on an open dense subset of the class of models considered here.

Network Structure among Brain Systems in Adult ADHD is Uniquely Modified by Stimulant Administration.

Current research in connectomics highlights that self-organized functional networks or "communities" of cortical areas can be detected in the adult brain. This perspective may provide clues to mechanisms of treatment response in psychiatric conditions. Here we examine functional brain community topology based on resting-state fMRI in adult Attention-Deficit/Hyperactivity Disorder (ADHD; n = 22) and controls (n = 31). We sought to evaluate ADHD patterns in adulthood and their modification by short term stimulants administration. Participants with ADHD were scanned one or two weeks apart, once with medication and once without; comparison participants were scanned at one time-point. Functional connectivity was estimated from these scans and community detection applied to determine cortical network topology. Measures of change in connectivity profile were calculated via a graph measure, termed the Node Dissociation Index (NDI). Compared to controls, several cortical networks had atypical connectivity in adults with ADHD when withholding stimulants, as measured by NDI. In most networks stimulants significantly reduced, but did not eliminate, differences in the distribution of connections between key brain systems relative to the control sample. These findings provide an enriched model of connectivity in ADHD and demonstrate how stimulants may exert functional effects by altering connectivity profiles in the brain.

Abnormal functional connectivity in women with urgency urinary incontinence: Can we predict disease presence and severity in individual women using Rs-fcMRI/.

AIMS: To identify atypical brain functional connectivity in women with UUI and detrusor overactivity (DO) and to predict the presence/severity of UUI in individual women using connectivity features. METHODS: This is a cross-sectional study comparing brain functional connectivity in women with and without UUI. Validated symptom/quality of life questionnaires were used for phenotyping. Participants are females between ages 40 and 85 with daily UUI with DO (Cases, N = 16) and without UUI (Controls, N = 24). Functional MRI and Resting state connectivity MRI were obtained at empty/ full bladder. Multivariate pattern analysis (MVPA) was used to predict the presence and severity of UUI from connectivity data. RESULTS: There are significant differences in brain activation between cases and controls in eighteen brain regions irrespective of empty or full bladder. These include regions involved in attention (inferior partietal), decision making (inferior and superior frontal gyrus), primary motor and sensory (precentral and postcentral gyrus) functions. Women with UUI showed no change in connectivity with bladder filling in regions involved in interoception (insula), integration of afferent function (anterior cingulate), and decision making (middle frontal). MVPA of connectivity data showed robust classification of an individual woman as case or control (89% sensitivity, 83% specificity). Six connectivity features accurately predicted disease severity (R(2) = 0.81). CONCLUSION: We identified two mechanisms of abnormal bladder control, one involving atypical activation of brain regions, and another atypical functional integration across sensory, emotional, cognitive and motor regions. Connectivity information is robust enough to classify an individual as having UUI or not and to predict symptom severity. Neurourol. Urodynam. 35:564-573, 2016. © 2015 Wiley Periodicals, Inc.

Disaster preparedness in a complex urban system: the case of Kathmandu Valley, Nepal.

The city is a growing centre of humanitarian concern. Yet, aid agencies, governments and donors are only beginning to comprehend the scale and, importantly, the complexity of the humanitarian challenge in urban areas. Using the case study of the Kathmandu Valley, Nepal, this paper examines the analytical utility of recent research on complex urban systems in strengthening scholarly understanding of urban disaster risk management, and outlines its operational relevance to disaster preparedness. Drawing on a literature review and 26 interviews with actors from across the Government of Nepal, the International Red Cross and Red Crescent Movement, non-governmental organisations, United Nations agencies, and at-risk communities, the study argues that complexity can be seen as a defining feature of urban systems and the risks that confront them. To manage risk in these systems effectively, preparedness efforts must be based on adaptive and agile approaches, incorporating the use of network analysis, partnerships, and new technologies.

Early life stress is associated with default system integrity and emotionality during infancy.

BACKGROUND: Extensive animal research has demonstrated the vulnerability of the brain to early life stress (ELS) with consequences for emotional development and mental health. However, the influence of moderate and common forms of stress on early human brain development is less well-understood and precisely characterized. To date, most work has focused on severe forms of stress, and/or on brain functioning years after stress exposure. METHODS: In this report we focused on conflict between parents (interparental conflict), a common and relatively moderate form of ELS that is highly relevant for children's mental health outcomes. We used resting state functional connectivity MRI to examine the coordinated functioning of the infant brain (N = 23; 6-12-months-of-age) in the context of interparental conflict. We focused on the default mode network (DMN) due to its well-characterized developmental trajectory and implications for mental health. We further examined DMN strength as a mediator between conflict and infants' negative emotionality. RESULTS: Higher interparental conflict since birth was associated with infants showing stronger connectivity between two core DMN regions, the posterior cingulate cortex (PCC) and the anterior medial prefrontal cortex (aMPFC). PCC to amygdala connectivity was also increased. Stronger PCC-aMPFC connectivity mediated between higher conflict and higher negative infant emotionality. CONCLUSIONS: The developing DMN may be an important marker for effects of ELS with relevance for emotional development and subsequent mental health. Increasing understanding of the associations between common forms of family stress and emerging functional brain networks has potential to inform intervention efforts to improve mental health outcomes.

Quantifying brain development in the HEALthy Brain and Child Development (HBCD) Study: The magnetic resonance imaging and spectroscopy protocol.

The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. The acquisition of multimodal magnetic resonance-based brain development data is central to the study's core protocol. However, application of Magnetic Resonance Imaging (MRI) methods in this population is complicated by technical challenges and difficulties of imaging in early life. Overcoming these challenges requires an innovative and harmonized approach, combining age-appropriate acquisition protocols together with specialized pediatric neuroimaging strategies. The HBCD MRI Working Group aimed to establish a core acquisition protocol for all 27 HBCD Study recruitment sites to measure brain structure, function, microstructure, and metabolites. Acquisition parameters of individual modalities have been matched across MRI scanner platforms for harmonized acquisitions and state-of-the-art technologies are employed to enable faster and motion-robust imaging. Here, we provide an overview of the HBCD MRI protocol, including decisions of individual modalities and preliminary data. The result will be an unparalleled resource for examining early neurodevelopment which enables the larger scientific community to assess normative trajectories from birth through childhood and to examine the genetic, biological, and environmental factors that help shape the developing brain.

Omicron neutralizing antibody response following booster vaccination compared with breakthrough infection.

The rapid spread of the vaccine-resistant Omicron variant of SARS-CoV-2 presents a renewed threat to both unvaccinated and fully vaccinated individuals, and accelerated booster vaccination campaigns are underway to mitigate the ongoing wave of Omicron cases. The degree of immunity provided by standard vaccine regimens, boosted regimens, and immune responses elicited by the combination of vaccination and natural infection remain incompletely understood. The relative magnitude, quality and durability of serological responses, and the likelihood of neutralizing protection against future SARS-CoV-2 variants following these modes of exposure are unknown but are critical to the future trajectory of the COVID-19 pandemic. In this study of 99 vaccinated adults, we find that compared with responses after two doses of an mRNA regimen, the immune responses three months after a third vaccine dose and one month after breakthrough infection due to prior variants show dramatic increases in magnitude, potency, and breadth, including increased antibody dependent cellular phagocytosis and robust neutralization of the recently circulating Omicron variant. These results suggest that as the number of Omicron cases rise and as global vaccination and booster campaigns continue, an increasing proportion of the world’s population will acquire potent immune responses that may be protective against future SARS-CoV-2 variants.

Omicron neutralizing antibody response following booster vaccination compared with breakthrough infection.

BACKGROUND: The spread of the vaccine-resistant Omicron severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens unvaccinated and fully vaccinated individuals, and accelerated booster vaccination campaigns are underway to mitigate the ongoing wave of Omicron cases. The immunity provided by standard vaccine regimens, boosted regimens, and immune responses elicited by vaccination plus natural infection remain incompletely understood. The magnitude, quality, and durability of serological responses, and the likelihood of protection against future SARS-CoV-2 variants following these modes of exposure, are poorly characterized but are critical to the future trajectory of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Ninety-nine individuals were semi-randomly selected from a larger vaccination cohort following vaccination and, in some cases, breakthrough infection. We analyzed spike receptor-binding domain-specific immunoglobulin G (IgG), IgA, and IgM by enzyme-linked immunosorbent assay, neutralizing antibody titers against live SARS-CoV-2 variants, and antibody-dependent cell-mediated phagocytosis. FINDINGS: In 99 vaccinated adults, compared with responses after two doses of an mRNA regimen, the immune responses 3 months after a third vaccine dose and 1 month after breakthrough infection due to prior variants show dramatic increases in magnitude, potency, and breadth, including increased antibody-dependent cellular phagocytosis and robust neutralization of the currently circulating Omicron BA.2 variant. CONCLUSIONS: Boosters and natural infection substantially boost immune responses. As the number of Omicron sub-variant cases rise and as global vaccination and booster campaigns continue, an increasing proportion of the world's population will acquire potent immune responses that may be protective against future SARS-CoV-2 variants. FUNDING: This work was funded by the M. J. Murdock Charitable Trust, the OHSU Foundation, the NIH (T32HL083808), and OHSU Innovative IDEA.

Addressing Intergenerational Trauma in an Adolescent Reunification Program: Case Studies Illustrating Service Innovation.

Adolescents in out-of-home care generally have poor prospects for reunification with their birth families. However, for some adolescents in care, with deliberate support and intervention, there may opportunities for successful reunification. The Adolescent Reunification Program (ARP) is an Australian program designed to assist young people aged 12-17 years return home to their families. The program focuses on supporting families, mentoring young people so as to meet their developmental and educational needs, and providing a safe home environment. It also included an innovative therapeutic component which focused on addressing the consequences of intergenerational trauma in order to help repair relationships between parents and children. The purpose of this paper is to describe the therapeutic component of the program and to examine the potential value of therapy in a family reunification context with a particular focus on client receptivity and preliminary evidence on outcomes. Using case illustrations, this paper describes the therapeutic component of the ARP and provides a preliminary evaluation of these components using a mixed methods approach, including standardised psychological assessments, qualitative interviews with parents and young people, and reflections from the program workers. The therapeutic component of the ARP may have helped to break the cycle of intergenerational trauma by bringing focus to the interrelationships between how people feel and how they act. This was done through the work of therapists attempting to combine non-judgmental exploration and positive therapeutic framing with practical support within the context of the environment where the family reunification occurred. Therapy in conjunction with practical supports within a multidisciplinary collaborative approach may help to facilitate better outcomes for reunification when working with complex families.

Characterizing heterogeneity in children with and without ADHD based on reward system connectivity.

One potential obstacle limiting our ability to clarify ADHD etiology is the heterogeneity within the disorder, as well as in typical samples. In this study, we utilized a community detection approach on 106 children with and without ADHD (aged 7-12 years), in order to identify potential subgroups of participants based on the connectivity of the reward system. Children with ADHD were compared to typically developing children within each identified community, aiming to find the community-specific ADHD characteristics. Furthermore, to assess how the organization in subgroups relates to behavior, we evaluated delay-discounting gradient and impulsivity-related temperament traits within each community. We found that discrete subgroups were identified that characterized distinct connectivity profiles in the reward system. Importantly, which connections were atypical in ADHD relative to the control children were specific to the community membership. Our findings showed that children with ADHD and typically developing children could be classified into distinct subgroups according to brain functional connectivity. Results also suggested that the differentiation in "functional" subgroups is related to specific behavioral characteristics, in this case impulsivity. Thus, combining neuroimaging data and community detection might be a valuable approach to elucidate heterogeneity in ADHD etiology and examine ADHD neurobiology.