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Suicidal behaviors are prevalent among college students; however, students remain reluctant to seek support. We developed a predictive algorithm to identify students at risk of suicidal behavior and used telehealth to reduce subsequent risk.
Methods
Data come from several waves of a prospective cohort study (2016–2022) of college students (n = 5454). All first-year students were invited to participate as volunteers. (Response rates range: 16.00–19.93%). A stepped-care approach was implemented: (i) all students received a comprehensive list of services; (ii) those reporting past 12-month suicidal ideation were directed to a safety planning application; (iii) those identified as high risk of suicidal behavior by the algorithm or reporting 12-month suicide attempt were contacted via telephone within 24-h of survey completion. Intervention focused on support/safety-planning, and referral to services for this high-risk group.
Results
5454 students ranging in age from 17–36 (s.d. = 5.346) participated; 65% female. The algorithm identified 77% of students reporting subsequent suicidal behavior in the top 15% of predicted probabilities (Sensitivity = 26.26 [95% CI 17.93–36.07]; Specificity = 97.46 [95% CI 96.21–98.38], PPV = 53.06 [95% CI 40.16–65.56]; AUC range: 0.895 [95% CIs 0.872–0.917] to 0.966 [95% CIs 0.939–0.994]). High-risk students in the Intervention Cohort showed a 41.7% reduction in probability of suicidal behavior at 12-month follow-up compared to high-risk students in the Control Cohort.
Conclusions
Predictive risk algorithms embedded into universal screening, coupled with telehealth intervention, offer significant potential as a suicide prevention approach for students.
The vegetation at and beyond the northern edge of the world’s boreal forest plays an important though imperfectly understood role in the climate system. This is particularly true within Russia, where only a small proportion of the boreal land area has been studied in depth, and little is known about its recent evolution over time. We describe a long-term collaboration between institutions in Russia and the United Kingdom, aimed at developing a better understanding of high-latitude vegetation in Russia using remote sensing methods. The focus of the collaboration has varied over time; in its most recent form, it is concerned with the dynamics of the Russian boreal forest during the 21st century and its relation to climate change. We discuss the support framework within which it has been developed and reflect on its relationship to science diplomacy. We consider the factors that have contributed to the success of a decades-long international collaboration and make recommendations as to how such joint efforts can be encouraged in future.
Provision of high-quality care and ensuring retention of children on antiretroviral therapy (ART) are essential to reduce human immunodeficiency virus (HIV)-associated morbidity and mortality. Virological non-suppression (≥1000 viral copies/ml) is an indication of suboptimal HIV care and support. This retrospective cohort study included ART-naïve children who initiated first-line ART between July 2015 and August 2017 in Johannesburg and rural Mopani district. Of 2739 children started on ART, 29.5% (807/2739) were lost to care at the point of analysis in August 2018. Among retained children, overall virological non-suppression was 30.2% (469/1554). Virological non-suppression was associated with higher loss to care 30.3% (229/755) compared with suppressed children (9.7%, 136/1399, P < 0.001). Receiving treatment in Mopani was associated with virological non-suppression in children under 5 years (adjusted odds ratio (aOR) 1.7 (95% confidence interval (CI) 1.1–2.4), 5–9 years (aOR 1.8 (1.1–3.0)) and 10–14 years (aOR 1.9 (1.2–2.8)). Virological non-suppression was associated with lower CD4 count in children 5–9 years (aOR 2.1 (1.1–4.1)) and 10–14 years (aOR 2.1 (1.2–3.8)). Additional factors included a shorter time on ART (<5 years aOR 1.8–3.7 (1.3–8.2)), and male gender (5–9 years, aOR1.5 (1.01–2.3)), and receiving cotrimoxazole prophylaxis (10–14 years aOR 2.0 (1.2–3.6)). In conclusion, virological non-suppression is a factor of subsequent programme loss in both regions, and factors affecting the quality of care need to be addressed to achieve the third UNAIDS 90 in paediatric HIV.
Individuals with schizophrenia are at higher risk of physical illnesses, which are a major contributor to their 20-year reduced life expectancy. It is currently unknown what causes the increased risk of physical illness in schizophrenia.
Aims
To link genetic data from a clinically ascertained sample of individuals with schizophrenia to anonymised National Health Service (NHS) records. To assess (a) rates of physical illness in those with schizophrenia, and (b) whether physical illness in schizophrenia is associated with genetic liability.
Method
We linked genetic data from a clinically ascertained sample of individuals with schizophrenia (Cardiff Cognition in Schizophrenia participants, n = 896) to anonymised NHS records held in the Secure Anonymised Information Linkage (SAIL) databank. Physical illnesses were defined from the General Practice Database and Patient Episode Database for Wales. Genetic liability for schizophrenia was indexed by (a) rare copy number variants (CNVs), and (b) polygenic risk scores.
Results
Individuals with schizophrenia in SAIL had increased rates of epilepsy (standardised rate ratio (SRR) = 5.34), intellectual disability (SRR = 3.11), type 2 diabetes (SRR = 2.45), congenital disorders (SRR = 1.77), ischaemic heart disease (SRR = 1.57) and smoking (SRR = 1.44) in comparison with the general SAIL population. In those with schizophrenia, carrier status for schizophrenia-associated CNVs and neurodevelopmental disorder-associated CNVs was associated with height (P = 0.015–0.017), with carriers being 7.5–7.7 cm shorter than non-carriers. We did not find evidence that the increased rates of poor physical health outcomes in schizophrenia were associated with genetic liability for the disorder.
Conclusions
This study demonstrates the value of and potential for linking genetic data from clinically ascertained research studies to anonymised health records. The increased risk for physical illness in schizophrenia is not caused by genetic liability for the disorder.
Schizophrenia is a highly heritable disorder with undetermined neurobiological causes. Understanding the impact on brain anatomy of carrying genetic risk for the disorder will contribute to uncovering its neurobiological underpinnings.
Aims
To examine the effect of rare copy number variants (CNVs) associated with schizophrenia on brain cortical anatomy in a sample of unaffected participants from the UK Biobank.
Method
We used regression analyses to compare cortical thickness and surface area (total and across gyri) between 120 unaffected carriers of rare CNVs associated with schizophrenia and 16 670 participants without any pathogenic CNV. A measure of cortical thickness and surface area covariance across gyri was also compared between groups.
Results
Carrier status was associated with reduced surface area (β = −0.020 mm2, P < 0.001) and less robustly with increased cortical thickness (β = 0.015 mm, P = 0.035), and with increased covariance in thickness (carriers z = 0.31 v. non-carriers z = 0.22, P < 0.0005). Associations were mainly present in frontal and parietal areas and driven by a limited number of rare risk alleles included in our analyses (mainly 15q11.2 deletion for surface area and 16p13.11 duplication for thickness covariance).
Conclusions
Results for surface area conformed with previous clinical findings, supporting surface area reductions as an indicator of genetic liability for schizophrenia. Results for cortical thickness, though, argued against its validity as a potential risk marker. Increased structural thickness covariance across gyri also appears related to risk for schizophrenia. The heterogeneity found across the effects of rare risk alleles suggests potential different neurobiological gateways into schizophrenia's phenotype.
For outbreaks of gastrointestinal disease, rapid identification of the source is crucial to enable public health intervention and prevent further cases. Outbreak investigation comprises analyses of exposure information from cases and, if required, undertaking analytical epidemiological studies. Hypothesis generation has been reliant on empirical knowledge of exposures historically associated with a given pathogen. Epidemiology studies are resource-intensive and prone to bias, one of the reasons being the difficulties in recruiting appropriate controls. For this paper, the information from cases was compared against pre-defined background exposure information. As exemplars, three past outbreaks were used, one of common and two of rare exposures. Information from historical case trawling questionnaires was used to define background exposure having removed any exposures implicated with the outbreak. The case-background approach showed good sensitivity and specificity, identifying correctly all outbreak-related exposures. One additional exposure related to a retailer was identified and four food items where all cases had been exposed. In conclusion, the case-background method, a development of the case-case design, can be used to assist with hypothesis generation or when a case-control study may not be possible to carry out.
Iron deficiency is common in pregnant and lactating women and is associated with reduced cognitive development of the offspring. Since iron affects lipid metabolism, the availability of fatty acids, particularly the polyunsaturated fatty acids required for early neural development, was investigated in the offspring of female rats fed iron-deficient diets during gestation and lactation. Subsequent to the dams giving birth, one group of iron-deficient dams was recuperated by feeding an iron-replete diet. Dams and neonates were killed on postnatal days 1, 3 and 10, and the fatty acid composition of brain and stomach contents was assessed by gas chromatography. Changes in the fatty acid profile on day 3 became more pronounced on day 10 with a decrease in the proportion of saturated fatty acids and a compensatory increase in monounsaturated fatty acids. Long-chain polyunsaturated fatty acids in the n-6 family were reduced, but there was no change in the n-3 family. The fatty acid profiles of neonatal brain and stomach contents were similar, suggesting that the change in milk composition may be related to the changes in the neonatal brain. When the dams were fed an iron-sufficient diet at birth, the effects of iron deficiency on the fatty acid composition of lipids in both dam’s milk and neonates’ brains were reduced. This study showed an interaction between maternal iron status and fatty acid composition of the offspring’s brain and suggests that these effects can be reduced by iron repletion of the dam’s diet at birth.
In recent years, the discovery of massive quasars at $z\sim7$ has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Universe. Mounting observational and theoretical evidence indicates the viability of massive seeds, formed by the collapse of supermassive stars, as a progenitor model for such early, massive accreting black holes. Although considerable progress has been made in our theoretical understanding, many questions remain regarding how (and how often) such objects may form, how they live and die, and how next generation observatories may yield new insight into the origin of these primordial titans. This review focusses on our present understanding of this remarkable formation scenario, based on the discussions held at the Monash Prato Centre from November 20 to 24, 2017, during the workshop ‘Titans of the Early Universe: The Origin of the First Supermassive Black Holes’.
Around 30% of individuals with schizophrenia remain symptomatic and significantly impaired despite antipsychotic treatment and are considered to be treatment resistant. Clinicians are currently unable to predict which patients are at higher risk of treatment resistance.
Aims
To determine whether genetic liability for schizophrenia and/or clinical characteristics measurable at illness onset can prospectively indicate a higher risk of treatment-resistant psychosis (TRP).
Method
In 1070 individuals with schizophrenia or related psychotic disorders, schizophrenia polygenic risk scores (PRS) and large copy number variations (CNVs) were assessed for enrichment in TRP. Regression and machine-learning approaches were used to investigate the association of phenotypes related to demographics, family history, premorbid factors and illness onset with TRP.
Results
Younger age at onset (odds ratio 0.94, P = 7.79 × 10−13) and poor premorbid social adjustment (odds ratio 1.64, P = 2.41 × 10−4) increased risk of TRP in univariate regression analyses. These factors remained associated in multivariate regression analyses, which also found lower premorbid IQ (odds ratio 0.98, P = 7.76 × 10−3), younger father's age at birth (odds ratio 0.97, P = 0.015) and cannabis use (odds ratio 1.60, P = 0.025) increased the risk of TRP. Machine-learning approaches found age at onset to be the most important predictor and also identified premorbid IQ and poor social adjustment as predictors of TRP, mirroring findings from regression analyses. Genetic liability for schizophrenia was not associated with TRP.
Conclusions
People with an earlier age at onset of psychosis and poor premorbid functioning are more likely to be treatment resistant. The genetic architecture of susceptibility to schizophrenia may be distinct from that of treatment outcomes.
Xpert MTB/RIF (Xpert) is the preferred first-line test for all persons with tuberculosis (TB) symptoms in South Africa in line with a diagnostic algorithm. This study evaluates pre- and post-implementation trends in diagnostic practices for drug-sensitive, pulmonary TB in adults in an operational setting, following the introduction of the Xpert-based algorithm. We retrospectively analysed data from the national TB database for Greater Tzaneen sub-district, Limpopo Province. Trends in a number of cases, diagnosis and outcome and characteristics associated with death are reported. A total of 8407 cases were treated from 2008 until 2015, with annual cases registered decreasing by 31·7% over that time period (from 1251 to 855 per year). After implementation of Xpert, 69·9% of cases were diagnosed by Xpert, 29·4% clinically, 0·6% by smear microscopy and 0·1% by culture. Cases with a recorded microbiological test increased from 76·2% to 96·4%. Cases started on treatment without confirmation, but with a negative microbiological test increased from 7·1% to 25·7%. Case fatality decreased from 15·0% to 9·8%, remaining consistently higher in empirically treated groups, regardless of HIV status. Implementation of the algorithm coincided with a reduced number of TB cases treated and improved coverage of microbiological testing; however, a substantial proportion of cases continued to start treatment empirically.
Dementia is a neurodegenerative disorder with global impact, with the largest proportion of cases occurring in low- and middle-income countries. It is estimated that there are 46.8 million cases globally with approximately 10 million new cases each year or a new case occurring every 3 sec (Prince et al., 2015). For comparison there are 36.7 million HIV cases with an estimated 2 million new cases each year (WHO, 2017). The rise in dementia prevalence is largely due to population ageing, with the oldest being at highest risk. To date there are no diseases modifying medications for Alzheimer's disease or the other causes of dementia. Academics and research groups are increasingly focused on prevention or delay of dementia (Brayne and Miller, 2017) and a number of organizations now prioritize dementia, indicating a strong and coherent international effort to address this problem. Examples include the World Health Organisation (WHO), which has established a Global Dementia Observatory; the World Dementia Council; the Organisation for Economic Co-operation and Development (OECD); the U.S. National Alzheimer's Project Act (NAPA); and the Global Council on Brain Health.
Mitochondrial dysfunction and resulting changes in adiposity have been observed in the offspring of animals fed a high fat (HF) diet. As iron is an important component of the mitochondria, we have studied the offspring of female rats fed complete (Con) or iron-deficient (FeD) rations for the duration of gestation to test for similar effects. The FeD offspring were ~12% smaller at weaning and remained so because of a persistent reduction in lean tissue mass. The offspring were fed a complete (stock) diet until 52 weeks of age after which some animals from each litter were fed a HF diet for a further 12 weeks. The HF diet increased body fat when compared with animals fed the stock diet, however, prenatal iron deficiency did not change the ratio of fat:lean in either the stock or HF diet groups. The HF diet caused triglyceride to accumulate in the liver, however, there was no effect of prenatal iron deficiency. The activity of the mitochondrial electron transport complexes was similar in all groups including those challenged with a HF diet. HF feeding increased the number of copies of mitochondrial DNA and the prevalence of the D-loop mutation, however, neither parameter was affected by prenatal iron deficiency. This study shows that the effects of prenatal iron deficiency differ from other models in that there is no persistent effect on hepatic mitochondria in aged animals exposed to an increased metabolic load.
The beetle Oberea erythrocephala, whose larvae mine stems and roots of leafy spurge (Euphorbia esula L. # EPHES), was introduced into Oregon, Montana, and Wyoming between 1980 and 1984. Although it was not recovered in Oregon and Wyoming, it became established at two of three release sites in Montana and appears to be accepting leafy spurge plants at a fourth.
Larvae of the leafy spurge hawk moth were sprayed with and/or were fed leafy spurge plants sprayed with 2,4-D or picloram. Larval survival was not affected from contact with the chemicals, from feeding on contaminated foliage, or from a combination of both. Viable second-generation adult moths were produced in all treatments. Thus, leafy spurge infested with the leafy spurge hawk moth can be sprayed with 2,4-D or picloram without injury to larvae that have reached the fourth or fifth instar stages.
A weevil [Rhinocyllus conicus (Froelich)] host specific to Carduus, Cirsium, Silybum, and Onopordum, was introduced into Gallatin County, Montana, for biocontrol of musk thistle (Carduus nutans L.). Releases were made in 1969, 1971, 1972, and 1973 on local musk thistle infestations. The insects became established and overwintered successfully. In 1974, R. conicus was found over a 1,280-km2 area of the county in seed heads of musk thistle. Weevil larvae severely infected the primary flowers, but only a few secondary and later flowers were attacked. Seed production from infected primary flowers was greatly reduced, and other factors influenced reduction of seeds from secondary and later flowers.
Ceutorhynchus litura dispersed 9 km in 15 yr from its point of release in 1972 with incident of infestation of Canada thistle plants at one study site reaching 92% in 1987. Plants generally survived larval feeding in the spring, but holes created by departing larvae provided entrances for arthropods, nematodes, and diseases. Subsequent mortality rates were high for belowground Canada thistle shoots. However, the number of new shoots from underground roots the following spring usually offset the mortality that had been indirectly caused by C. litura.
Plant growth, stem numbers per plant, receptacle diameters, number of Rhinocyllus conicus Froelich (Coleoptera:Curculionidae) larval cells per seed head, and mortality of the weevil within cells were monitored in infestations of the thistles Carduus thoermeri Weinmann and C. macrocephalus Deft. Both species of thistle provided similar seed head area for weevil development, and no differential effects on the biology of R. conicus were detected.
We examined whether image analysis could separate leafy spurge from other plant species and objects by comparing image analysis to the ocular method of estimating cover. Image analysis was acceptably precise at low and medium cover levels. Image analysis was as repeatable as the ocular method at all sites and cover levels and acceptably reliable at low and medium cover levels but estimated cover lower by 12 to 22% than the ocular method at high cover levels. The average error levels of image analysis and the ocular method did not differ. Estimating leafy spurge cover with a 10% error required only 20 quadrats when image analysis was used, while twice as many quadrats were needed when cover was measured ocularly. Image analysis was recommended as a measurement tool because quantification was efficient, the equipment is inexpensive, and the color prints provide a permanent photo record of the study.
Fascinating connections exist between group theory and automata theory, and a wide variety of them are discussed in this text. Automata can be used in group theory to encode complexity, to represent aspects of underlying geometry on a space on which a group acts, and to provide efficient algorithms for practical computation. There are also many applications in geometric group theory. The authors provide background material in each of these related areas, as well as exploring the connections along a number of strands that lead to the forefront of current research in geometric group theory. Examples studied in detail include hyperbolic groups, Euclidean groups, braid groups, Coxeter groups, Artin groups, and automata groups such as the Grigorchuk group. This book will be a convenient reference point for established mathematicians who need to understand background material for applications, and can serve as a textbook for research students in (geometric) group theory.