Broadband silicon nitride integrated polarization rotators at 780 nm.

Polarization management, and in particular polarization rotation, is becoming increasingly important for photonic integrated circuits (PICs). While fiber-optic networks are generally polarization insensitive, the large aspect ratio of high-index-contrast PIC waveguides leads to a large polarization-dependent response of integrated components such as waveguides, optical cavities, couplers, etc. Although foundry-processed polarization rotators operating at telecom and datacom wavelengths (C- and O-band) have been demonstrated, to date, there have been few reports of devices operating at shorter wavelengths.

MEMS-tunable polarization management in photonic integrated circuits.

Optical fibers are generally polarization-insensitive while photonic integrated circuits (PICs) often exhibit a large polarization dependence due to the high-aspect-ratio and high-index-contrast of integrated waveguides. As PICs become more mature there is an increasing need for tunable polarization management on-chip. Although micro-electro-mechanical systems (MEMS) are increasingly finding application in PICs for optical switching and phase shifting, they have so far not found wide application for polarization management.

Examining the psychobiological response to acute social stress across clinical stages and symptom trajectories in the early psychosis continuum.

The stress-vulnerability model has been repeatedly highlighted in relation to the risk, onset and course of psychosis, and has been independently studied in clinical high-risk (CHR) and first-episode psychosis (FEP) populations. Notable in this literature, however, is that there are few studies directly comparing markers of stress response across progressive stages of illness. Here we examined the psychobiological response to the Trier Social Stress Test in 28 CHR (mean age 19.

Micro-electro-mechanically tunable optical phase matching and mode conversion.

Mode-division multiplexing (MDM) enables a large increase in the information-carrying capacity of an optical network. Recently, chip-scale MDM devices that can switch different mode orders to different output waveguides have been demonstrated. However, an important milestone showing dynamically tunable mode-order conversion in a single compact device has so far not been reported.

Flapping Soft Fin Deformation Modeling using Planar Laser-Induced Fluorescence Imaging.

Propulsive mechanisms inspired by the fins of various fish species have been increasingly researched, given their potential for improved maneuvering and stealth capabilities in unmanned vehicle systems. Soft materials used in the membranes of these fin mechanisms have proven effective at increasing thrust and efficiency compared with more rigid structures, but it is essential to measure and model the deformations in these soft membranes accurately. This study presents a workflow for characterizing the time-dependent shape deformation of flexible underwater flapping fins using planar laser-induced fluorescence (PLIF).

Severe childhood trauma and emotion recognition in males and females with first-episode psychosis.

Aim: Childhood trauma increases social functioning deficits in first-episode psychosis (FEP) and is negatively associated with higher-order social cognitive processes such as emotion recognition (ER). We investigated the relationship between childhood trauma severity and ER capacity, and explored sex as a potential factor given sex differences in childhood trauma exposure.

Methods: Eighty-three FEP participants (52 males, 31 females) and 69 nonclinical controls (49 males, 20 females) completed the CogState Research Battery.

The effects of childhood adversity on treatment delays and its components in first-episode psychosis.

Apart from increasing risk for psychotic disorders, childhood adversity has been associated with worse outcomes. One way in which childhood adversity may worsen outcomes is by lengthening treatment delays, which are associated with negative impacts. We tested the influence of childhood trauma on treatment delays, measured as the duration of untreated psychosis (DUP), and its help-seeking and referral components, in a first-episode psychosis cohort (N = 203).

A meta-analysis of blood and salivary cortisol levels in first-episode psychosis and high-risk individuals.

Dysregulated cortisol responses and glucose metabolism have been reported in psychosis. We performed a random-effects meta-analysis of cortisol responses in first-episode psychosis (FEP) and psychosis risk states, taking into consideration glucose metabolism. A total of 47 studies were included.

Impact of childhood trauma on positive and negative symptom remission in first episode psychosis.

Objective: Early life adversity is suspected to play an important role for onset and course of psychosis, but its relationship with longer-term clinical outcome is not entirely clear. In this longitudinal study, we investigated the impact of childhood trauma (CT) on positive and negative symptom remission in first episode psychosis (FEP) patients over two years.

Methods: A total of 210 FEP patients were assessed with the Childhood Trauma Questionnaire.

Passive photonic integration of lattice filters for waveguide-enhanced Raman spectroscopy.

To perform waveguide-enhanced Raman spectroscopy (WERS) or fluorescence spectroscopy in a compact device, the optical fibers to couple the passive photonic circuit to the laser source and detector require attachment directly to the die. This necessitates the integration of edge couplers and waveguide-based filters to isolate the fiber background emission from the on-chip signal, while efficiently coupling the pump laser and detector to the input and output fibers, respectively. In this work, we experimentally demonstrate the successful integration of four-port lattice filters with sensing spirals and inverse-taper edge couplers in a passive photonic circuit.

Figure-of-Merit Characterization of Hydrogen-Bond Acidic Sorbents for Waveguide-Enhanced Raman Spectroscopy.

The optical properties of several hydrogen-bond acidic sorbent materials are evaluated in situ to assess their suitability for waveguide-enhanced Raman spectroscopy (WERS) of vapor-phase organophosphonates. A number of characteristics critical to WERS are evaluated for each sorbent: infrared absorption, Raman spectral background, and the limit of detection for a test hydrogen-bond-basic analyte (dimethyl methylphosphonate, DMMP). We describe the chemical properties of the sorbents that differentiate their optical properties for sensing.

Loss reduction in electromechanically tunable microring cavities.

Nanophotonic structures coupled with mechanics enable large effective index perturbation. To date, however, the relation between index tuning and induced optical loss has not been considered in detail. In this work we present an in-depth study of optical loss mechanisms in an electromechanically-tunable waveguide filter.

Individualized Prediction of Transition to Psychosis in 1,676 Individuals at Clinical High Risk: Development and Validation of a Multivariable Prediction Model Based on Individual Patient Data Meta-Analysis.

The Clinical High Risk state for Psychosis (CHR-P) has become the cornerstone of modern preventive psychiatry. The next stage of clinical advancements rests on the ability to formulate a more accurate prognostic estimate at the individual subject level. Individual Participant Data Meta-Analyses (IPD-MA) are robust evidence synthesis methods that can also offer powerful approaches to the development and validation of personalized prognostic models.

The Trier Social Stress Test in first episode psychosis patients: Impact of perceived stress, protective factors and childhood trauma.

Psychosis has been associated with abnormalities in hypothalamic-pituitary-adrenal axis functioning, which may emerge through heightened stress sensitivity following early life adversity - ultimately resulting in illness onset and progression. The present study assessed cortisol levels during an established psychosocial stress task and their association with current stress perception, putative protective factors and adverse childhood experiences in patients with a first episode of psychosis (FEP). A total of 100 volunteers participated in the study, 57 of whom were patients with a FEP (mean age 23.

Does an integrated outreach intervention targeting multiple stages of early psychosis improve the identification of individuals at clinical high risk?

Aims: To explore the impact of a targeted case identification intervention, with training and education regarding first-episode psychosis and clinical high-risk syndromes, on the referral and identification of those at high risk.

Methods: Using a historical control design, referral information from pre-intervention and post-intervention periods was collected via administrative data and clinician notes from a catchment-based early psychosis service.

Results: A significant increase in the number of referrals sent to the service's clinical high-risk unit was observed following the intervention (P = 0.

Waveguide-enhanced Raman spectroscopy of trace chemical warfare agent simulants.

We report the measurement of waveguide-enhanced Raman spectra from trace concentrations of four vapor-phase chemical warfare agent simulants: dimethyl methylphosphonate, diethyl methylphosphonate, trimethyl phosphate, and triethyl phosphate. The spectra are obtained using highly evanescent nanophotonic silicon nitride waveguides coated with a naturally reversible hyperbranched carbosilane sorbent polymer and exhibit extrapolated one-σ detection limits as low as 5 ppb. We use a finite-element model to explain the polarization and wavelength properties of the differential spectra.

Gender differences in childhood trauma in first episode psychosis: Association with symptom severity over two years.

Early life adversity is associated with increased risk for psychosis onset and poor clinical outcome. Male compared to female patients often show a more severe course of psychotic illness. The aim of the present study was to investigate gender differences in childhood trauma (CT) and their impact on symptomatic and functional outcome following psychosis onset.

Social Determinants of Health and Preclinical Glycemic Control in Newly Diagnosed First-Episode Psychosis Patients.

Background: The abnormally high incidence of disorders of glucose metabolism (DGM) in psychotic-spectrum disorders (PSD) has often been attributed to the side effects of antipsychotics and unhealthy lifestyles. The influence of social determinants of health has been largely ignored, despite ample evidence linking social adversity with both PSD and DGM. The aim of this study is to examine the influence of well-established social determinants of health on preclinical levels of glycated hemoglobin (HbA1c) in a sample of first-episode psychosis (FEP) patients.

Neuroanatomical and Symptomatic Sex Differences in Individuals at Clinical High Risk for Psychosis.

Sex differences have been widely observed in clinical presentation, functional outcome and neuroanatomy in individuals with a first-episode of psychosis, and chronic patients suffering from schizophrenia. However, little is known about sex differences in the high-risk stages for psychosis. The present study investigated sex differences in cortical and subcortical neuroanatomy in individuals at clinical high risk (CHR) for psychosis and healthy controls (CTL), and the relationship between anatomy and clinical symptoms in males at CHR.

Outcome in patients converting to psychosis following a treated clinical high risk state.

Aim: We explored 2-year outcomes in a sample of clinical high risk (CHR) patients who converted to psychosis despite receiving interventions.

Methods: Of 167 CHR patients, 18 had converted to psychosis and received treatment for their first episode of psychosis in an early intervention service over 2 years.

Results: Compared to patients admitted directly to the same early intervention service without having been identified as CHR prior to onset of psychosis, CHR converters were in remission for fewer months (M = 5 vs M = 10); were more likely to be prescribed more than 1 antipsychotic medication (90% vs 68%) and to receive clozapine treatment (38% vs 2%) over 2 years.

The neural diathesis-stress model of schizophrenia revisited: An update on recent findings considering illness stage and neurobiological and methodological complexities.

Over the past decade, our understanding of the role of stress in serious mental illness has become more sophisticated. In this paper, we revisit the neural diathesis-stress model of schizophrenia that was initially proposed in 1997 and updated in 2008. In light of cumulative research findings, we must now encompass evidence on the premorbid periods of psychosis, and our more nuanced understanding of hypothalamic-pituitary-adrenal (HPA) axis function and its association with neurodevelopmental, epigenetic, neurotransmitter, and inflammatory processes, as well as brain structure and function.