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In Canada, recreational use of cannabis was legalized in October 2018. This policy change along with recent publications evaluating the efficacy of cannabis for the medical treatment of epilepsy and media awareness about its use have increased the public interest about this agent. The Canadian League Against Epilepsy Medical Therapeutics Committee, along with a multidisciplinary group of experts and Canadian Epilepsy Alliance representatives, has developed a position statement about the use of medical cannabis for epilepsy. This article addresses the current Canadian legal framework, recent publications about its efficacy and safety profile, and our understanding of the clinical issues that should be considered when contemplating cannabis use for medical purposes.
Global inequity in access to and availability of essential mental health services is well recognized. The mental health treatment gap is approximately 50% in all countries, with up to 90% of people in the lowest-income countries lacking access to required mental health services. Increased investment in global mental health (GMH) has increased innovation in mental health service delivery in LMICs. Situational analyses in areas where mental health services and systems are poorly developed and resourced are essential when planning for research and implementation, however, little guidance is available to inform methodological approaches to conducting these types of studies. This scoping review provides an analysis of methodological approaches to situational analysis in GMH, including an assessment of the extent to which situational analyses include equity in study designs. It is intended as a resource that identifies current gaps and areas for future development in GMH. Formative research, including situational analysis, is an essential first step in conducting robust implementation research, an essential area of study in GMH that will help to promote improved availability of, access to and reach of mental health services for people living with mental illness in low- and middle-income countries (LMICs). While strong leadership in this field exists, there remain significant opportunities for enhanced research representing different LMICs and regions.
Using country- and institution-level data, we find that the “coming wave” of emerging- market (EM) investors systematically over- or underweight their equity portfolio holdings in a way that reflects the influences of past capital and trade flows from a foreign country. We interpret this finding as support for van Nieuwerburgh and Veldkamp (2009) information endowment hypothesis. Strong past capital and trade flows create an information advantage that leads EM investors to disproportionately overweight a given foreign market, even relative to developed market investor counterparts. We also pursue predictions of the information endowment hypothesis by constructing novel information-advantage proxies based on relationships among investment firms and the headquarters of their parent companies. These proxies also offer reliable explanatory power for international portfolio allocations.
Suicide-related behaviours are common in schizophrenia and are significantly associated with premature death. The objective of this meta-analysis study was to estimate the pooled prevalence of suicide-related behaviours in schizophrenia patients in China.
The relevant literature was searched systematically via the relevant electronic databases (PubMed, Embase, PsycINFO, Chinese National Knowledge Infrastructure, Wanfang Databases and Chinese Biological Medical Literature Database) from their inception until 14 September 2016. Only original studies that reported the prevalence of suicide-related behaviours including suicidal ideation (SI), suicide plan, suicide attempt (SA) and completed suicide were selected.
Nineteen articles met the inclusion criteria and were analysed. The pooled lifetime prevalence of SI and SA were 25.8% (95% CI 14.7–41.1%) and 14.6% (95% CI 9.1–22.8%), respectively. The 1-month prevalence of SI was 22.0% (95% CI 18.2–26.4%). Subgroup analyses of lifetime SI and SA showed that gender, sample size, survey year, study location and source of patients have no significant mediating effects on the results.
Suicide-related behaviours are common in Chinese schizophrenia patients. Due to the high mortality risk, regular screening and effective suicide prevention programmes are warranted.
Dysfunction of N-methyl-D-aspartate receptor (NMDAR) is involved in the pathophysiology of schizophrenia. A meta-analysis of randomized controlled trials (RCTs) was conducted to examine the efficacy and safety of memantine, a non-competitive NMDAR antagonist, in the treatment of schizophrenia.
Standardized/weighted mean differences (SMDs/WMDs), risk ratio (RR), and their 95% confidence intervals (CIs) were calculated and analyzed.
Included in the meta-analysis were eight RCTs (n = 452) of 11.5 ± 2.6 weeks duration, with 229 patients on memantine (20 mg/day) and 223 patients on placebo. Adjunctive memantine outperformed placebo in the measures of Positive and Negative Syndrome Scale and Brief Psychiatric Rating Scale negative symptoms [SMD: −0.63 (95% CI −1.10 to −0.16), p = 0.009, I2 = 77%], but not in the total, positive and general symptoms [SMD: −0.46 to −0.08 (95% CI −0.93 to 0.22), p = 0.06–0.60, I2 = 0–74%] or the Clinical Global Impression Severity Scale [WMD: 0.04 (95% CI −0.24 to 0.32), p = 0.78]. The negative symptoms remained significant after excluding one outlying RCT [SMD: −0.41 (95% CI −0.72 to −0.11), p = 0.008, I2 = 47%]. Compared with the placebo group, adjunctive memantine was associated with significant improvement in neurocognitive function using the Mini-Mental State Examination (MMSE) [WMD: 3.09, (95% CI 1.77–4.42), p < 0.00001, I2 = 22%]. There was no significant difference in the discontinuation rate [RR: 1.34 (95% CI 0.76–2.37), p = 0.31, I2 = 0%] and adverse drug reactions between the two groups.
This meta-analysis showed that adjunctive memantine appears to be an efficacious and safe treatment for improving negative symptoms and neurocognitive performance in schizophrenia. Higher quality RCTs with larger samples are warranted to confirm these findings.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
It is unclear if the impact of psychoeducational family intervention for patients with schizophrenia can be sustained over 10 years. In this study, we explored the 14-year effect of psychoeducational family intervention for patients with schizophrenia in a Chinese rural area.
The data from a cluster randomized control trial (CRCT) study of psychoeducational family intervention in a 14-year follow-up was analyzed. All patients with schizophrenia (n = 326) who participated in the CRCT drawn from six townships in Xinjin County of Chengdu in 1994, of whom 238 (73.0%) who were still alive, and their informants were followed up in 2008. The Patients Follow-up Scale, the Positive and Negative Syndrome Scale (PANSS) and the Global Assessment of Functioning were used in the follow-up study.
There were no significant differences of marital status, mean scores of PANSS positive symptoms, negative symptoms, general mental health, and total scores among the psychoeducational family intervention, medication, and control groups in 2008. The psychoeducational family intervention group had a significantly higher rate of antipsychotic medication and a higher level of work ability than other two groups. The control group had a significantly higher rate of never-treated (26.0%) than psychoeducational family intervention group (6.5%).
Psychoeducational family intervention might be still effective in the 14-year follow-up, especially in patients’ treatment adherence/compliance and social functioning. Psychoeducational family intervention might be more effective in places where family members frequently participated in patients’ care and had a lower level of knowledge on mental illness. Family intervention should be considered when making mental health policy and planning mental health services.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
Metal-assisted chemical etching (MACE) of silicon (Si) is a simple and low-cost process to fabricate Si nanostructures with varying aspect ratio and properties. In this work, we report on the structural and vibrational properties of Si nanostructures synthesized with varying metal catalyst. The morphology of the synthesized nanowires was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical and vibrational properties of the Si nanostructures were studied by photoluminescence and Raman spectroscopy using three different excitation sources (UV, visible and near-infrared) and are correlated to their microstructures. We propose that the excessive injection of holes into Si at the metal-Si interface and its diffusion to the nanowire surfaces facilitate the etching of Si on these surfaces, leading to a mesoporous network of Si nanocrystallites. When etched with catalytic Au nanoparticles, “hay-stacked” mesoporous Si nanowires were obtained. The straighter nanowires etched with Ag nanoparticles, consisted of a single crystalline core with a thin porous layer that decreased in thickness towards the base of the nanowire. This difference is due to the higher catalytic activity of Au compared to Ag for H2O2 decomposition. The SERRS observed during UV and visible Raman with Ag-etched Si nanowires and near-infrared Raman with Au-etched Si nanowires is due to the presence of the sunken metal nanoparticles. In addition, we explored the influence of varying H2O2 and HF concentration as well as the influence of increased etching temperature on the resultant nanostructured Si morphology. Such Si nanostructures may be useful for a wide range of applications such as photovoltaic and biological and chemical sensing.
Although usually thought of as external environmental stressors, a significant heritable component has been reported for measures of stressful life events (SLEs) in twin studies.
We examined the variance in SLEs captured by common genetic variants from a genome-wide association study (GWAS) of 2578 individuals. Genome-wide complex trait analysis (GCTA) was used to estimate the phenotypic variance tagged by single nucleotide polymorphisms (SNPs). We also performed a GWAS on the number of SLEs, and looked at correlations between siblings.
A significant proportion of variance in SLEs was captured by SNPs (30%, p = 0.04). When events were divided into those considered to be dependent or independent, an equal amount of variance was explained for both. This ‘heritability’ was in part confounded by personality measures of neuroticism and psychoticism. A GWAS for the total number of SLEs revealed one SNP that reached genome-wide significance (p = 4 × 10−8), although this association was not replicated in separate samples. Using available sibling data for 744 individuals, we also found a significant positive correlation of R2 = 0.08 in SLEs (p = 0.03).
These results provide independent validation from molecular data for the heritability of reporting environmental measures, and show that this heritability is in part due to both common variants and the confounding effect of personality.
The chemical stability of a GaAs layer structure consisting of a thin (10 nm) layer of low-temperature-grown GaAs (LTG:GaAs) on a heavily n-doped GaAs layer, both grown by molecular beam epitaxy, is described. Scanning tunneling spectroscopy and X-ray photoelectron spectroscopy performed after atmospheric exposure indicate that the LTG:GaAs surface layer oxidizes much less rapidly than comparable layers of stoichiometric GaAs. There is also evidence that the terminal oxide thickness is smaller than that of stoichiometric GaAs. The spectroscopy results are used to confirm a model for conduction in low resistance, nonalloyed contacts employing comparable layer structures. The inhibited surface oxidation rate is attributed to the bulk Fermi level pinning and the low minority carrier lifetime in unannealed LTG:GaAs. Device applications including low-resistance cap layers for field-effect transistors are described.
Ultra-thin HfOxNy gate dielectric films were deposited by pulse-mode metalorganic chemical vapor deposition (MOCVD) with [(C2H5)2N]4Hf (TDEAH) and either NO or O2 as oxidants. Nitrogen incorporation was studied by x-ray photoelectron spectroscopy (XPS) and spatially-resolved elemental profiles were obtained by scanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS) and energy dispersive x-ray spectroscopy (EDS). The results indicate that nitrogen is incorporated throughout the high-k film with a higher concentration in the interface layer between the deposited layer and the Si(100) substrate. The concentration of nitrogen is increased in both layers by using NO instead of O2 as the oxidant. The N in the deposited and interface layers can be replaced by oxygen during oxygen ambient annealing at temperatures above 500 °C. Films with 8 at.% nitrogen remain amorphous following vacuum annealing at temperatures up to 800 °C. By encapsulating vacuum-annealed films with amorphous Si from an e-beam evaporator prior to removal from the cluster tool, it was possible to reduce the thickness of the interface layer upon air exposure to the 0.5 nm range.
This study was performed to determine the prevalence, distribution of specimen sources, and antimicrobial susceptibility of the Acinetobacter calcoaceticus–Acinetobacter baumannii (Acb) species complex in Singapore. One hundred and ninety-three non-replicate Acb species complex clinical isolates were collected from six hospitals over a 1-month period in 2006. Of these, 152 (78·7%) were identified as A. baumannii, 18 (9·3%) as ‘Acinetobacter pittii’ [genomic species (gen. sp.) 3], and 23 (11·9%) as ‘Acinetobacter nosocomialis’ (gen. sp. 13TU). Carbapenem resistance was highest in A. baumannii (72·4%), followed by A. pittii (38·9%), and A. nosocomialis (34·8%). Most carbapenem-resistant A. baumannii and A. nosocomialis possessed the blaOXA-23-like gene whereas carbapenem-resistant A. pittii possessed the blaOXA-58-like gene. Two imipenem-resistant strains (A. baumannii and A. pittii) had the blaIMP-like gene. Representatives of carbapenem-resistant A. baumannii were related to European clones I and II.
The present study assessed the relationship between breakfast frequency and measures of obesity in Hong Kong Chinese children aged 9–18 years. A total of 11 570 children (50 % boys) underwent anthropometric measurements and completed a simple self-administered dietary behaviour questionnaire. Their parents completed a questionnaire providing demographic information. Breakfast frequency was assessed by a single question, ‘How many days over the past week did you have breakfast?’ Children were categorised into three groups: skippers (ate breakfast 0–2 times/week); semi-skippers (ate breakfast 3–4 times/week); non-skippers (ate breakfast 5–7 times/week), to assess all associated characteristics. Of the 3644 primary and 7926 secondary school students, 8 % (8·7 % of boys and 6·9 % of girls) and 14 % (14 % of boys and 15 % of girls), respectively, were breakfast skippers. The prevalence of obesity among breakfast skippers, semi-skippers and non-skippers was, respectively, 9·8, 10·6 and 3·8 % (P < 0·001) for primary school students and 3·9, 3·1 and 2·4 % (P < 0·001) for secondary school students. The 12 % of Hong Kong children aged 9–18 years who skipped breakfast had higher BMI, BMI z-scores and percentage of body fat (PBF) than their counterparts. The dose effects of breakfast frequency (unstandardised regression coefficient, P < 0·001) on BMI and PBF were, respectively, − 0·125 kg/m2 and − 0·219 % for boys and − 0·165 kg/m2 and − 0·353 % for girls, adjusting for physical activity per additional breakfast meal per week. Further study is recommended to elucidate whether regular breakfast consumption may have a role in the prevention of childhood obesity.
Rapid thermal annealing (RTA) of 1000Å GaNAs films grown on (100) oriented GaAs substrate by radio frequency (RF) plasma assisted solid-source molecular beam epitaxy was studied by low-temperature photoluminescence (PL) and high-resolution x-ray diffraction (HRXRD). Samples with nitrogen content of 13 and 2.2% have shown an overall blueshift in energy of 67.7meV and an intermediate redshift of 42.2meV in the PL spectra when subjected to RTA at 525–850°C for 10min. It is also shown that the sample, which is annealed at temperature range of 700–750°C, has the highest photoluminescence efficiency (1.7–2.1 times increase in integrated PL intensity as compared to the as-grown sample). Reciprocal space mapping of the as-grown GaNAs samples obtained by using triple-crystal HRXRD shows the presence of interstitially incorporated of N atoms with no lattice relaxation in the direction parallel to the growth surface. These results have significant implication on the growth and post-growth treatment of nitride compound semiconductor materials for high performance optoelectronics devices.
GaNAs and GaInNAs growths are subjects of considerable interest due to its technological importance in long wavelength lasers emitting within the optical-fiber communication wavelength window (1.31 – 1.55 m m). We study GaNAs and GaInNAs materials growth on (100) semi-insulating GaAs substrate with high nitrogen compositions (>2%) using a solid source molecular beam epitaxy (SSMBE) system in conjunction with a RF plasma source. GaNAs layer with high nitrogen compositions of 4.85% and 6% with good XRD peak intensities were successfully grown. GaInNAs quantum wells (QWs) were then grown with reference to the nitrogen compositions measured in the GaNAs materials to obtain nitrogen compositions > 2%. The photoluminescence (PL) peak positions of the GaInNAs QWs blueshifted after annealing at 840°C and 10min. It was found that the blueshift of PL peaks are highly dependent on nitrogen compositions.