Random trees with superexponential branching weights

We study rooted planar random trees with a probability distribution which is proportional to a product of weight factors $w_n$ associated to the vertices of the tree and depending only on their individual degrees $n$. We focus on the case when $w_n$ grows faster than exponentially with $n$. In this case the measures on trees of finite size $N$ converge weakly as $N$ tends to infinity to a measure which is concentrated on a single tree with one vertex of infinite degree. For explicit weight factors of the form $w_n=((n-1)!)^\alpha$ with $\alpha >0$ we obtain more refined results about the approach to the infinite volume limit.Comment: 19 page

Mean-field methods in evolutionary duplication-innovation-loss models for the genome-level repertoire of protein domains

We present a combined mean-field and simulation approach to different models describing the dynamics of classes formed by elements that can appear, disappear or copy themselves. These models, related to a paradigm duplication-innovation model known as Chinese Restaurant Process, are devised to reproduce the scaling behavior observed in the genome-wide repertoire of protein domains of all known species. In view of these data, we discuss the qualitative and quantitative differences of the alternative model formulations, focusing in particular on the roles of element loss and of the specificity of empirical domain classes.Comment: 10 Figures, 2 Table

Trauma-informed care for adult survivors of developmental trauma with psychotic and dissociative symptoms: a systematic review of intervention studies

Developmental trauma is associated with an increased risk of psychosis and predicts poor prognosis. Despite this association, little is known about which treatments work best for survivors of developmental trauma with psychosis. We sought to do the first review, to our knowledge, to investigate treatments for people with psychotic and dissociative symptoms who have a history of developmental trauma. We searched MEDLINE, PsychINFO, and Google Scholar for studies reporting psychological and pharmacological treatments of psychotic or dissociative symptoms in adult survivors of developmental trauma. We identified 24 studies, most of which investigated various modalities of psychotherapy with two case reports of pharmacological treatments. There is preliminary evidence in favour of third wave cognitive therapies. However, because of low methodological quality and reporting in most of the studies found, it remains unknown which treatments are most effective in this clinical group. Nonetheless, our findings of potential treatment targets, including emotion regulation, acceptance, interpersonal skills, trauma re-processing, and the integration of dissociated ego states, could guide future work in this area. Methodologically rigorous studies are needed to enable clinicians and patients to collaboratively form evidence-based treatment plans. Our Review is registered with PROSPERO, number CRD42018104533

Suicide risk in people with post-traumatic stress disorder: a cohort study of 3.1 million people in Sweden

BACKGROUND: It is unclear whether post-traumatic stress disorder [PTSD] is associated with suicide risk in the general population, whether this differs by sex, or what the population impact of PTSD is for suicide. METHODS: We constructed a nationwide cohort of all people living in Sweden, born 1973-1997, followed from their 14th birthday (or immigration, if later) until suicide, other death, emigration or 31 December 2016. We used Cox proportional hazards regression to estimate hazard ratios [HR], and calculated the population impact of PTSD on suicide. We included sensitivity analyses to explore effects of outcome and exposure definitions, and to account for potential competing risks. RESULTS: Of 3,177,706 participants, 22,361 (0•7%) were diagnosed with PTSD, and 6,319 (0•2%) died by suicide over 49•2 million person-years. Compared with women and men without PTSD, suicide rates were 6•74 (95%CI: 5•61-8•09) and 3•96 (95%CI: 3•12-5•03) times higher in those with PTSD, respectively, after sociodemographic adjustment. Suicide rates remained elevated in women (HR: 2•61; 95%CI: 2•16-3•14) and men (HR: 1•67; 95%CI: 1•31-2•12) after adjustment for previous psychiatric conditions; attenuation was driven by previous non-fatal suicide attempts. Findings were insensitive to definitions or competing risks. If causal, 1•6% (95%CI: 1•2-2•1) of general population suicides could be attributed to PTSD, and up to 53.7% (95%CI: 46.1-60.2) in people with PTSD. LIMITATIONS: Residual confounding remains possible due to depressive and anxiety disorders diagnosed in primary care but unrecorded in these registers. CONCLUSIONS: Clinical guidelines for the management of people with PTSD should recognise increased suicide risk

Impact of land surface initialization approach on subseasonal forecast skill: A regional analysis in the southern hemisphere

The authors use a sophisticated coupled land–atmosphere modeling system for a Southern Hemisphere subdomain centered over southeastern Australia to evaluate differences in simulation skill from two different land surface initialization approaches. The first approach uses equilibrated land surface states obtained from offline simulations of the land surface model, and the second uses land surface states obtained from reanalyses. The authors find that land surface initialization using prior offline simulations contribute to relative gains in subseasonal forecast skill. In particular, relative gains in forecast skill for temperature of 10%–20% within the first 30 days of the forecast can be attributed to the land surface initialization method using offline states. For precipitation there is no distinct preference for the land surface initialization method, with limited gains in forecast skill irrespective of the lead time. The authors evaluated the asymmetry between maximum and minimum temperatures and found that maximum temperatures had the largest gains in relative forecast skill, exceeding 20% in some regions. These results were statistically significant at the 98% confidence level at up to 60 days into the forecast period. For minimum temperature, using reanalyses to initialize the land surface contributed to relative gains in forecast skill, reaching 40% in parts of the domain that were statistically significant at the 98% confidence level. The contrasting impact of the land surface initialization method between maximum and minimum temperature was associated with different soil moisture coupling mechanisms. Therefore, land surface initialization from prior offline simulations does improve predictability for temperature, particularly maximum temperature, but with less obvious improvements for precipitation and minimum temperature over southeastern Australia

Neurological Soft Signs in Individuals with Pathological Gambling

Increased neurological soft signs (NSSs) have been found in a number of neuropsychiatric syndromes, including chemical addiction. The present study examined NSSs related to perceptual-motor and visuospatial processing in a behavioral addiction viz., pathological gambling (PG). As compared to mentally healthy individuals, pathological gamblers displayed significantly poorer ability to copy two- and three-dimensional figures, to recognize objects against a background noise, and to orient in space on a road-map test. Results indicated that PG is associated with subtle cerebral cortical abnormalities. Further prospective clinical research is needed to address the NSSs' origin and chronology (e.g., predate or follow the development of PG) as well as their response to therapeutic interventions and/or their ability to predict such a response

Levy-Student Distributions for Halos in Accelerator Beams

We describe the transverse beam distribution in particle accelerators within the controlled, stochastic dynamical scheme of the Stochastic Mechanics (SM) which produces time reversal invariant diffusion processes. This leads to a linearized theory summarized in a Shchr\"odinger--like (\Sl) equation. The space charge effects have been introduced in a recent paper~\cite{prstab} by coupling this \Sl equation with the Maxwell equations. We analyze the space charge effects to understand how the dynamics produces the actual beam distributions, and in particular we show how the stationary, self--consistent solutions are related to the (external, and space--charge) potentials both when we suppose that the external field is harmonic (\emph{constant focusing}), and when we \emph{a priori} prescribe the shape of the stationary solution. We then proceed to discuss a few new ideas~\cite{epac04} by introducing the generalized Student distributions, namely non--Gaussian, L\'evy \emph{infinitely divisible} (but not \emph{stable}) distributions. We will discuss this idea from two different standpoints: (a) first by supposing that the stationary distribution of our (Wiener powered) SM model is a Student distribution; (b) by supposing that our model is based on a (non--Gaussian) L\'evy process whose increments are Student distributed. We show that in the case (a) the longer tails of the power decay of the Student laws, and in the case (b) the discontinuities of the L\'evy--Student process can well account for the rare escape of particles from the beam core, and hence for the formation of a halo in intense beams.Comment: revtex4, 18 pages, 12 figure

Extreme value statistics from the Real Space Renormalization Group: Brownian Motion, Bessel Processes and Continuous Time Random Walks

We use the Real Space Renormalization Group (RSRG) method to study extreme value statistics for a variety of Brownian motions, free or constrained such as the Brownian bridge, excursion, meander and reflected bridge, recovering some standard results, and extending others. We apply the same method to compute the distribution of extrema of Bessel processes. We briefly show how the continuous time random walk (CTRW) corresponds to a non standard fixed point of the RSRG transformation.Comment: 24 pages, 5 figure

Stochastic B\"acklund transformations

How does one introduce randomness into a classical dynamical system in order to produce something which is related to the `corresponding' quantum system? We consider this question from a probabilistic point of view, in the context of some integrable Hamiltonian systems

Mechanics of Combining Divergent Herbivores in Cultivated Pastures

Sustainable intensification of cultivated pastures is needed in ruminant production if we are to feed a growing world population expected to exceed 9 billion by 2050. Planting pastures of diverse, and therefore more productive and resilient, plant species has been proposed and researched. Despite illustrative examples from wild grasslands (Hofmann, 1989) and rangelands (Glimp, 1988), very little research and even less application of multiple herbivore species (MHS) in cultivated pastures has followed. We review the specific mechanics of divergent domesticated ruminants and theorize how these could best be combined to sustainably intensify meat, milk and fiber production from cultivated pastures around the world