A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology

BACKGROUND: Understanding variations in the incidence of schizophrenia is a crucial step in unravelling the aetiology of this group of disorders. The aims of this review are to systematically identify studies related to the incidence of schizophrenia, to describe the key features of these studies, and to explore the distribution of rates derived from these studies. METHODS: Studies with original data related to the incidence of schizophrenia (published 1965–2001) were identified via searching electronic databases, reviewing citations and writing to authors. These studies were divided into core studies, migrant studies, cohort studies and studies based on Other Special Groups. Between- and within-study filters were applied in order to identify discrete rates. Cumulative plots of these rates were made and these distributions were compared when the underlying rates were sorted according to sex, urbanicity, migrant status and various methodological features. RESULTS: We identified 100 core studies, 24 migrant studies, 23 cohort studies and 14 studies based on Other Special Groups. These studies, which were drawn from 33 countries, generated a total of 1,458 rates. Based on discrete core data for persons (55 studies and 170 rates), the distribution of rates was asymmetric and had a median value (10%–90% quantile) of 15.2 (7.7–43.0) per 100,000. The distribution of rates was significantly higher in males compared to females; the male/female rate ratio median (10%–90% quantile) was 1.40 (0.9–2.4). Those studies conducted in urban versus mixed urban-rural catchment areas generated significantly higher rate distributions. The distribution of rates in migrants was significantly higher compared to native-born; the migrant/native-born rate ratio median (10%–90% quantile) was 4.6 (1.0–12.8). Apart from the finding that older studies reported higher rates, other study features were not associated with significantly different rate distributions (e.g. overall quality, methods related to case finding, diagnostic confirmation and criteria, the use of age-standardization and age range). CONCLUSIONS: There is a wealth of data available on the incidence of schizophrenia. The width and skew of the rate distribution, and the significant impact of sex, urbanicity and migrant status on these distributions, indicate substantial variations in the incidence of schizophrenia

Permeability and pressure measurements in Lesser Antilles submarine slides: Evidence for pressure-driven slow-slip failure

Recent studies hypothesize that some submarine slides fail via pressure-driven slow-slip deformation. To test this hypothesis, this study derives pore pressures in failed and adjacent unfailed deep marine sediments by integrating rock physics models, physical property measurements on recovered sediment core, and wireline logs. Two drill sites (U1394 and U1399) drilled through interpreted slide debris; a third (U1395) drilled into normal marine sediment. Near-hydrostatic fluid pressure exists in sediments at site U1395. In contrast, results at both sites U1394 and U1399 indicate elevated pore fluid pressures in some sediment. We suggest that high pore pressure at the base of a submarine slide deposit at site U1394 results from slide shearing. High pore pressure exists throughout much of site U1399, and Mohr circle analysis suggests that only slight changes in the stress regime will trigger motion. Consolidation tests and permeability measurements indicate moderately low (~10⁻¹⁶–10⁻¹⁷ m²) permeability and overconsolidation in fine-grained slide debris, implying that these sediments act as seals. Three mechanisms, in isolation or in combination, may produce the observed elevated pore fluid pressures at site U1399: (1) rapid sedimentation, (2) lateral fluid flow, and (3) shearing that causes sediments to contract, increasing pore pressure. Our preferred hypothesis is this third mechanism because it explains both elevated fluid pressure and sediment overconsolidation without requiring high sedimentation rates. Our combined analysis of subsurface pore pressures, drilling data, and regional seismic images indicates that slope failure offshore Martinique is perhaps an ongoing, creep-like process where small stress changes trigger motion

Modeling mixed conductivity in solid-state electrolytes

The overarching goal of the the first-principles computational studies presented in this dissertation is to better understand and predict charge carrier interactions in mixed conductors. Rare-earth phosphates and hematite are chosen as example insulators which show reasonably high proton and polaron conductivity, respectively. Rare-earth phosphates are not yet used commercially, but show promise as intermediate temperature fuel-cell electrolytes, so a first-prinicples atomic-level understanding of transport in these materials will enable engineering of their properties. Due to close collaborations with experimentalists working in synthesis and characterization of rare-earth phosphates via impedance, X-ray photoemission, and NMR spectroscopy, the density functional theory (DFT) studies are compared directly to experimental measurements. Significant charge carrier concentrations are created in these materials by aliovalent doping, which can significantly increase the activation energy barrier for transport through the material. In this thesis, the interaction of protons and Ba-dopants in LaPO4 is investigated and the X-ray photoemission spectrum of CePO4 is interpreted via its calculated electronic structure, showing that hole small-polarons on Ce ions are stable defects. Finally, a new method for calculating small-polaron mobilities in crystals with DFT plus a Hubbard-U term is presented and found to work well for electron small-polaron mobilities in hematite

Role of Dynamically Frustrated Bond Disorder in a Li⁺ Superionic Solid Electrolyte

Inorganic lithium solid electrolytes are critical components in next-generation solid-state batteries, yet the fundamental nature of the cation–anion interactions and their relevance for ionic conductivity in these materials remain enigmatic. Here, we employ first-principles molecular dynamics simulations to explore the interplay among chemistry, structure, and functionality of a highly conductive Li⁺ solid electrolyte, Li₃InBr₆. Using local-orbital projections to dynamically track the evolution of the electronic charge density, the simulations reveal rapid, correlated fluctuations between cation–anion interactions with different degrees of directional covalent character. These chemical bond dynamics are shown to correlate with Li⁺ mobility and are enabled thermally by intrinsic frustration between the preferred geometries of chemical bonding and lattice symmetry. We suggest that the fluctuating chemical environment from the polarizable anions functions like a solvent, contributing to the superionic behavior of Li₃InBr₆ by temporarily stabilizing configurations favorable for migrating Li⁺. The generality of these conclusions for understanding solid electrolytes and key factors governing the superionic phase transition is discussed

Structure and Electronic Properties of Cerium Orthophosphate: Theory and Experiment

Structural and electronic properties of cerium orthophosphate (CePO{sub 4}) are calculated using density functional theory (DFT) with the local spin-density approximation (LSDA+U), with and without gradient corrections (GGA-(PBE)+U), and compared to X-ray diffraction and photoemission spectroscopy measurements. The density of states is found to change significantly as the Hubbard parameter U, which is applied to the Ce 4f states, is varied from 0 to 5 eV. The calculated structural properties are in good agreement with experiment and do not change significantly with U. Choosing U = 3 eV for LDSA provides the best agreement between the calculated density of states and the experimental photoemission spectra

Magnetic stability of oxygen defects on the SiO2 surface

The magnetic stability of E' centers and the peroxy radical on the surface of alpha-quartz is investigated with first-principles calculations to understand their role in magnetic flux noise in superconducting qubits (SQs) and superconducting quantum interference devices (SQUIDs) fabricated on amorphous silica substrates. Paramagnetic E' centers are common in both stoichiometric and oxygen deficient silica and quartz, and we calculate that they are more common on the surface than the bulk. However, we find the surface defects are magnetically stable in their paramagnetic ground state and thus will not contribute to 1/f noise through fluctuation at millikelvin temperatures.112sciescopu