Factors influencing the distribution of Cactoblastis cactorum, a biological control agent of Opuntia stricta in Kruger National Park, South Africa

Cactoblastis cactorum, a phycitid moth, has been used with considerable success as a biological control agent against several different cactus species in many parts of the world, including Opuntia stricta in Kruger National Park [KNP], South Africa. Although the moth has become widespread and abundant in KNP, its populations have not reached levels where it is able to provide the desired level of control on the alien species which has invaded more than 35 000 ha of the park and continues to spread. Although several factors, especially acquired predators and parasitoids, are known to curb the abundance of C. cactorum in South Africa, the extent to which this applies in KNP is unknown. Logistic regression and Canonical Community Analysis were used to determine the biotic and abiotic factors affecting the distribution and abundance of C. cactorum in KNP. To do this, maps of the ranges of the insect and host plant were constructed and integrated with other environmental features. The logistic regression showed that O. stricta density had no influence on whether or not C. cactorum was present in an area. The Canonical Community Analysis suggested that a high fire frequency, the herbicide control programme and the presence of small host plants may be important in limiting the distribution of C. cactorum, either directly or indirectly, through impacts on associated predators or parasitoids

Environmental factors influencing the distribution of Opuntia stricta, an invasive alien plant in the Kruger National Park, South Africa

Opuntia stricta (Cactaceae), an alien weed, has invaded an area of more than 35 000 ha in the Skukuza region of the Kruger National Park [KNP]. The distribution of the plant and features of the environment were used to identify biotic and abiotic factors which may be affecting the distribution and density of the plant. A Canonical Community Analysis revealed that none of the environmental factors that were monitored influenced the distribution or abundance of O. stricta in KNP. There were no apparent natural barriers that might limit the occurrence of O. stricta within the KNP. The study provides insight into the relationship between the invader and host environment, showing that there is a high probability that, unless there is appropriate intervention, O. stricta will eventually colonise the entire KNP

Pragmatic trials of non-NHS interventions: experiences from a Randomised Controlled Trial of the Strengthening Families 10-14 UK Programme (SFP10-14 UK)

Background: Pragmatic trials of public health interventions outside the NHS are relatively scarce, much needed and face particular challenges. These include funding, of intervention costs in particular; trial implementation in professional and organisational cultures unused to randomised trial procedures, including randomisation, maintaining the counterfactual, recruitment; and relevance of findings for and translation into policy and practice. Objectives: The current NPRI funded trial of SFP 10-14 UK is presented as a case study to discuss these issues, solutions and remaining barriers. The SFP 10-14 UK programme aims to strengthen areas of family life that protect against substance misuse, for example, parenting, communication, and young people’s resilience skills. The SFP 10-14 UK is being delivered by statutory and voluntary agencies in six local authority areas across Wales, and is offered to mixed groups comprised of families from the general population, and families who may experience/present challenges within a group setting. Methods: The trial aims to recruit 748 families, 374 of whom will be randomised to receive the usual services available to families within their local area. 374 families will receive the SFP 10-14 UK in addition to usual care. Families are identified by staff employed within the statutory services and voluntary sectors and referred to embedded research staff for recruitment. Results: Challenges encountered related to a lack of awareness of the randomised trial as a research paradigm among staff and key referring agencies, related concerns about the ethics of randomisation and the maintenance of the counterfactual among the usual care group, and challenges regarding the maintenance of recruitment and intervention fidelity. Whilst a challenge in itself, partnership working with delivery agencies, programme trainers, and the Welsh Assembly Government at all stages of the development, funding and conduct of the trial has proved an important strategy to overcome these issues. Conclusions: This trial seeks to generate evidence on the effectiveness and cost effectiveness of the SFP10-14 UK which is of direct relevance to policy makers, commissioners and practitioners. The trial highlights that strategic partnership working, the winning of ‘hearts and minds’ regarding the ethics and operationalisation of randomisation, and maintaining the balance between internal and external validity are key areas of focus for the successful conduct of pragmatic trials in non-NHS settings. The lessons learnt from its implementation will be important for future multi-sector/agency policy trials and for role out of the intervention if found to be efficacious

The biogeography of South African terrestrial plant invasions

Thousands of plant species have been introduced, intentionally and accidentally, to South Africa from many parts of the world. Alien plants are now conspicuous features of many South African landscapes and hundreds of species have naturalised (i.e. reproduce regularly without human intervention), many of which are also invasive (i.e. have spread over long distances). There is no comprehensive inventory of alien, naturalised, and invasive plants for South Africa, but 327 plant taxa, most of which are invasive, are listed in national legislation. We collated records of 759 plant taxa in 126 families and 418 genera that have naturalised in natural and semi-natural ecosystems. Over half of these naturalised taxa are trees or shrubs, just under a tenth are in the families Fabaceae (73 taxa) and Asteraceae (64); genera with the most species are Eucalyptus,Acacia, and Opuntia. The southern African Plant Invaders Atlas (SAPIA) provides the best data for assessing the extent of invasions at the national scale. SAPIA data show that naturalised plants occur in 83% of quarter-degree grid cells in the country. While SAPIA data highlight general distribution patterns (high alien plant species richness in areas with high native plant species richness and around the main human settlements), an accurate, repeatable method for estimating the area invaded by plants is lacking. Introductions and dissemination of alien plants over more than three centuries, and invasions over at least 120 years (and especially in the last 50 years) have shaped the distribution of alien plants in South Africa. Distribution patterns of naturalised and invasive plants define four ecologically-meaningful clusters or “alien plant species assemblage zones”, each with signature alien plant taxa for which trait-environment interactions can be postulated as strong determinants of success. Some widespread invasive taxa occur in high frequencies across multiple zones; these taxa occur mainly in riparian zones and other azonal habitats,or depend on human-mediated disturbance, which weakens or overcomes the factors that determine specificity to any biogeographical region

Social norms, social identities and the COVID-19 pandemic:Theory and recommendations

Funding information: Economic and Social Research Council grant awarded to FGN: ES/V005383/1.Sustained mass behaviour change is needed to tackle the COVID‐19 pandemic, but many of the required changes run contrary to existing social norms (e.g., physical closeness with in‐group members). This paper explains how social norms and social identities are critical to explaining and changing public behaviour. Recommendations are presented for how to harness these social processes to maximise adherence to COVID‐19 public health guidance. Specifically, we recommend that public health messages clearly define who the target group is, are framed as identity‐affirming rather than identity‐contradictory, include complementary injunctive and descriptive social norm information, are delivered by in‐group members and that support is provided to enable the public to perform the requested behaviours.Publisher PDFPeer reviewe

SPRING: an RCT study of probiotics in the prevention of gestational diabetes mellitus in overweight and obese women

Background: Obesity is increasing in the child-bearing population as are the rates of gestational diabetes. Gestational diabetes is associated with higher rates of Cesarean Section for the mother and increased risks of macrosomia, higher body fat mass, respiratory distress and hypoglycemia for the infant. Prevention of gestational diabetes through life style intervention has proven to be difficult. A Finnish study showed that ingestion of specific probiotics altered the composition of the gut microbiome and thereby metabolism from early gestation and decreased rates of gestational diabetes in normal weight women. In SPRING (the Study of Probiotics IN the prevention of Gestational diabetes), the effectiveness of probiotics ingestion for the prevention of gestational diabetes will be assessed in overweight and obese women

Drug education in victorian schools (DEVS): the study protocol for a harm reduction focused school drug education trial

<p>Abstract</p> <p>Background</p> <p>This study seeks to extend earlier Australian school drug education research by developing and measuring the effectiveness of a comprehensive, evidence-based, harm reduction focused school drug education program for junior secondary students aged 13 to 15 years. The intervention draws on the recent literature as to the common elements in effective school curriculum. It seeks to incorporate the social influence of parents through home activities. It also emphasises the use of appropriate pedagogy in the delivery of classroom lessons.</p> <p>Methods/Design</p> <p>A cluster randomised school drug education trial will be conducted with 1746 junior high school students in 21 Victorian secondary schools over a period of three years. Both the schools and students have actively consented to participate in the study. The education program comprises ten lessons in year eight (13-14 year olds) and eight in year nine (14-15 year olds) that address issues around the use of alcohol, tobacco, cannabis and other illicit drugs. Control students will receive the drug education normally provided in their schools. Students will be tested at baseline, at the end of each intervention year and also at the end of year ten. A self completion questionnaire will be used to collect information on knowledge, patterns and context of use, attitudes and harms experienced in relation to alcohol, tobacco, cannabis and other illicit drug use. Multi-level modelling will be the method of analysis because it can best accommodate hierarchically structured data. All analyses will be conducted on an Intent-to-Treat basis. In addition, focus groups will be conducted with teachers and students in five of the 14 intervention schools, subsequent to delivery of the year eight and nine programs. This will provide qualitative data about the effectiveness of the lessons and the relevance of the materials.</p> <p>Discussion</p> <p>The benefits of this drug education study derive both from the knowledge gained by trialling an optimum combination of innovative, harm reduction approaches with a large, student sample, and the resultant product. The research will provide better understanding of what benefits can be achieved by harm reduction education. It will also produce an intervention, dealing with both licit and illicit drug use that has been thoroughly evaluated in terms of its efficacy, and informed by teacher and student feedback. This makes available to schools a comprehensive drug education package with prevention characteristics and useability that are well understood.</p> <p>Trial registration</p> <p>Australia and New Zealand Clinical Trials Register (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12612000079842.aspx">ACTRN12612000079842</a></p

Alcohol, binge drinking and associated mental health problems in young urban Chileans

OBJECTIVE: To explore the link between alcohol use, binge drinking and mental health problems in a representative sample of adolescent and young adult Chileans. METHODS: Age and sex-adjusted Odds Ratios (OR) for four mental wellbeing measures were estimated with separate conditional logistic regression models for adolescents aged 15-20 years, and young adults aged 21-25 years, using population-based estimates of alcohol use prevalence rates from the Chilean National Health Survey 2010. RESULTS: Sixty five per cent of adolescents and 85% of young adults reported drinking alcohol in the last year and of those 83% per cent of adolescents and 86% of young adults reported binge drinking in the previous month. Adolescents who reported binging alcohol were also more likely, compared to young adults, to report being always or almost always depressed (OR 12.97 [95% CI, 1.86-19.54]) or to feel very anxious in the last month (OR 9.37 [1.77-19.54]). Adolescent females were more likely to report poor life satisfaction in the previous year than adolescent males (OR 8.50 [1.61-15.78]), feel always or almost always depressed (OR 3.41 [1.25-9.58]). Being female was also associated with a self-reported diagnosis of depression for both age groups (adolescents, OR 4.74 [1.49-15.08] and young adults, OR 4.08 [1.65-10.05]). CONCLUSION: Young people in Chile self-report a high prevalence of alcohol use, binge drinking and associated mental health problems. The harms associated with alcohol consumption need to be highlighted through evidence-based prevention programs. Health and education systems need to be strengthened to screen and support young people. Focussing on policy initiatives to limit beverage companies targeting alcohol to young people will also be needed

Invasion syndromes: a systematic approach for predicting biological invasions and facilitating effective management

Published: 02 March 2020Our ability to predict invasions has been hindered by the seemingly idiosyncratic context-dependency of individual invasions. However, we argue that robust and useful generalisations in invasion science can be made by considering “invasion syndromes” which we define as “a combination of pathways, alien species traits, and characteristics of the recipient ecosystem which collectively result in predictable dynamics and impacts, and that can be managed effectively using specific policy and management actions”. We describe this approach and outline examples that highlight its utility, including: cacti with clonal fragmentation in arid ecosystems; small aquatic organisms introduced through ballast water in harbours; large ranid frogs with frequent secondary transfers; piscivorous freshwater fishes in connected aquatic ecosystems; plant invasions in high-elevation areas; tall-statured grasses; and tree-feeding insects in forests with suitable hosts. We propose a systematic method for identifying and delimiting invasion syndromes. We argue that invasion syndromes can account for the context-dependency of biological invasions while incorporating insights from comparative studies. Adopting this approach will help to structure thinking, identify transferrable risk assessment and management lessons, and highlight similarities among events that were previously considered disparate invasion phenomena.Ana Novoa, David M. Richardson, Petr Pyšek, Laura A. Meyerson, Sven Bacher ... Jasmin Packer ... et al