The unpredicted host use of Chamaecytisus profiler by the introduced weed biocontrol agent, Bruchidius villosus: a retrospective analysis and explanation

This study investigates unpredicted host use by a weed biological control agent in New Zealand. Bruchidius villosus, a seed-feeding beetle, was released into New Zealand in 1986 as a biocontrol agent to aid in the control of Cytisus scoparius (Genisteae), a European shrub that has become widespread in New Zealand. Although host specificity tests had predicted that Chamaecytisus prolifer would not be attacked, in 1999 B. villosus was found utilising this plant as well as C. scoparius in the field in New Zealand. This finding prompted a thorough re-examination of historical rearing records, which showed that B. villosus does in fact exhibit a wider host range than was initially thought and forecast by New Zealand and UK testing. Uncertainty over the identity of B. villosus (which is referred to in some literature as B. ater and other synonyms) appears to have contributed to the misunderstanding of its known host range. To ascertain why host specificity tests (choice tests on cut shoots) failed to predict that Ch. prolifer would be a suitable oviposition host for B. villosus, a series offield and laboratory experiments were undertaken. The field host range of B. villosus in New Zealand was established: C. scoparius and Ch. prolifer were the only hosts oviposited on and no other native or exotic pod-bearing relatives of C. scoparius were found to be hosts in the field. However, subsequently (2003) beetles have also been collected from Lupinus arboreus in the field. In no-choice sleeved tests on whole plants in the field C. scoparius, Ch. prolifer and two additional species, Cytisus multiflorus and Genista monspessulana, were oviposited on, and adults emerged from all these species except C. multiflorus. These results supported European literature records that B. villosus has a broader host range. Mitochondrial DNA for B. villosus reared from a number of host plants from the UK, France, Spain, Germany, Hungary, Canada, and the USA was analysed to determine whether the current concept of B. villosus as a single species is valid. The alternative hypothesis was that B. villosus included a number of sibling species separated either geographically or by host plant. Results indicated that all beetles belong to the same species. Performance of B. villosus on C. scoparius and Ch. prolifer in the field was compared. Larval survival was significantly higher and development from egg to adult significantly faster on C. scoparius indicating it was the more suitable host for B. villosus. Despite apparently being a less suitable host, B. villosus destroys approximately 40% of available Ch. prolifer seed, compared to about 90% of C. scoparius seed. Aspects of the methodology of the original testing were examined to identify any feature of the experimental design that may have caused the failure of the original choice oviposition tests to detect the acceptability of Ch. prolifer. Firstly the effect of larval rearing host, adult food type and no overwintering period were studied. In all cases beetles oviposited on Ch. prolifer, though showing a strong preference for C. scoparius. Secondly quantity of oviposition resource, cage size and orientation of plant material were also investigated. Beetles laid eggs on Ch. prolifer when they were presented with equal amounts of test plant and control material in replicates identical in design to the original tests, but when the quantity of control pod resource presented in choice tests was half that of the test plant, oviposition increased on the test plants Ch. prolifer (significantly) and C. multiflorus. Cages of two different sizes and cut shoots presented horizontally or vertically had no significant effect on oviposition. In order to determine whether a host range expansion had occurred in the New Zealand population of B. villosus since its introduction from the UK, a comparison of oviposition preference was undertaken between New Zealand beetles and a newly imported population from the UK. Sample size was increased from two replicates (ten female beetles) in the original 1985 tests to ten replicates (50 female beetles). Beetles newly imported from the UK laid eggs on Ch. prolifer as well as on C. scoparius which ruled out the development of a host race with a broader host range in New Zealand. In only 40% of replicates were eggs laid on Ch. prolifer indicating that 20 (or less) females found Ch. prolifer acceptable for oviposition. Results from this experiment and from previous investigations suggested that insufficient replication could be responsible for the failure to detect oviposition on Ch. prolifer due to a high level of individual variation in oviposition preference among female beetles. Oviposition preference by individual female B. villosus beetles, from New Zealand and UK populations, between C. scoparius and Ch. prolifer was measured in a laboratory choice test. The variation in numbers of eggs laid was high, especially on Ch. prolifer (CV = 148% New Zealand population, CV = 166% UK population) compared with numbers on C. scoparius (CV = 97% New Zealand population, CV = 50% UK population). Although both populations showed an overall preference for C. scoparius, New Zealand populations showed higher acceptance of Ch. prolifer (New Zealand population: mean number of eggs 8.6 ± 1.6 SEM on C. scoparius, 6.5 ± 1.8 SEM on Ch. prolifer; UK population: mean number of eggs 12.7 ± 2.0 SEM on C. scoparius, 3.9 ± 2.0 SEM on Ch. prolifer). Nine of 29 New Zealand beetles laid more eggs on Ch. prolifer compared to none of the nine UK beetles that laid eggs. A sibling experiment using three mothers showed that there were no strong maternal influences on overwintering survival, longevity, fecundity or oviposition preference of offspring. Although as some beetles from the newly imported UK population accepted Ch. prolifer it was possible to rule out the likelihood of a host shift having taken place, there are indications from the differences in individual preferences shown between New Zealand and UK populations that differentiation in populations may be occurring. There seemed to be little maternal influence on preference, but further study is required to determine whether observed differences are inherited and whether host race formation is likely. Beetles reared from Ch. prolifer were bigger, more fecund and had higher overwintering survival. Longevity was similar for beetles reared from either host, but survival from egg to adult was higher and development faster on C. scoparius, the host preferred overall for oviposition. Clearly original choice host specificity tests failed to detect that B. villosus accepted Ch. prolifer because insufficient replication was used: testing 20 female beetles instead of 10 would have reduced the chance of selecting a sample that would lay no eggs on Ch. prolifer from 11 % to 0.02%. Lessons for host specificity testing in weed biological control are that high levels of individual variation in host preference require suitably high levels of replication to detect non-target effects and avoid type II errors (false negative results). This will inevitably generate larger numbers of type I errors (false positives) requiring detailed follow-up, preferably with individual insects. There are also indications that preference by an imported weed biological control agent for a non-target host plant may have changed over the 15 generations since its release, suggesting that test results for plant species that are new associations should be interpreted with particular care. The release of any agent that in no-choice tests accepts and develops fully on a valued host plant cannot be recommended for release, even if the level of attack is low

Physiotherapy students and clinical educators perceive several ways in which incorporating peer-assisted learning could improve clinical placements: a qualitative study

AbstractQuestion: What are the experiences of students and clinical educators in a paired student placement model incorporating facilitated peer-assisted learning (PAL) activities, compared to a traditional paired teaching approach? Design: Qualitative study utilising focus groups. Participants: Twenty-four physiotherapy students and 12 clinical educators. Intervention: Participants in this study had experienced two models of physiotherapy clinical undergraduate education: a traditional paired model (usual clinical supervision and learning activities led by clinical educators supervising pairs of students) and a PAL model (a standardised series of learning activities undertaken by student pairs and clinical educators to facilitate peer interaction using guided strategies). Results: Peer-assisted learning appears to reduce the students’ anxiety, enhance their sense of safety in the learning environment, reduce educator burden, maximise the use of downtime, and build professional skills including collaboration and feedback. While PAL adds to the clinical learning experience, it is not considered to be a substitute for observation of the clinical educator, expert feedback and guidance, or hands-on immersive learning activities. Cohesion of the student-student relationship was seen as an enabler of successful PAL. Conclusion: Students and educators perceive that PAL can help to position students as active learners through reduced dependence on the clinical educator, heightened roles in observing practice, and making and communicating evaluative judgments about quality of practice. The role of the clinical educator is not diminished with PAL, but rather is central in designing flexible and meaningful peer-based experiences and in balancing PAL with independent learning opportunities. Registration: ACTRN12610000859088. [Sevenhuysen S, Farlie MK, Keating JL, Haines TP, Molloy E (2015) Physiotherapy students and clinical educators perceive several ways in which incorporating peer-assisted learning could improve clinical placements: a qualitative study. Journal of Physiotherapy 61: 87–92

Ruling out a host-range expansion as the cause of the unpredicted non-target attack on tagasaste (Chamaecytisus proliferus) by Bruchidius villosus

Scotch broom (Cytisus scoparius) is a woody shrub of European origin that is an invasive weed in New Zealand. Bruchidius villosus was released in New Zealand in 1986 as a biological control agent of Scotch broom, after tests indicated that it was specific to this species. However, in 1999, B. villosus was discovered developing in the seeds of an unpredicted host, tagasaste or tree lucerne (Chamaecytisus proliferus). Although the original choice tests carried out in quarantine failed to predict acceptance of C. proliferus by ovipositing females, the current population in New Zealand clearly finds this species an acceptable host. An investigation of the original host-testing procedures revealed a number of possible limitations in the tests conducted in the 1980s. Concerns that a host-range expansion might have occurred in a weed biological control agent led to this study in which beetles from the original population (Silwood Park, United Kingdom) were reimported and the original handling and host choice tests were replicated. Despite showing a strong preference for Scotch broom, the beetles tested in this study accepted C. proliferus for oviposition. These results allow us to rule out the possibility that a hostrange expansion has occurred

Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere

For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe avian migration. Here, we present a three-stage modeling framework for estimating spatial patterns of avian migration. First, we integrate tracking and band re-encounter data to quantify migratory connectivity, defined as the relative proportions of individuals migrating between breeding and nonbreeding regions. Next, we use estimated connectivity proportions along with eBird occurrence probabilities to produce probabilistic least-cost path (LCP) indices. In a final step, we use generalized additive mixed models (GAMMs) both to evaluate the ability of LCP indices to accurately predict (i.e., as a covariate) observed locations derived from tracking and band re-encounter data sets versus pseudo-absence locations during migratory periods and to create a fully integrated (i.e., eBird occurrence, LCP, and tracking/band re-encounter data) spatial prediction index for mapping species-specific seasonal migrations. To illustrate this approach, we apply this framework to describe seasonal migrations of 12 bird species across the Western Hemisphere during pre- and postbreeding migratory periods (i.e., spring and fall, respectively). We found that including LCP indices with eBird occurrence in GAMMs generally improved the ability to accurately predict observed migratory locations compared to models with eBird occurrence alone. Using three performance metrics, the eBird + LCP model demonstrated equivalent or superior fit relative to the eBird-only model for 22 of 24 species–season GAMMs. In particular, the integrated index filled in spatial gaps for species with over-water movements and those that migrated over land where there were few eBird sightings and, thus, low predictive ability of eBird occurrence probabilities (e.g., Amazonian rainforest in South America). This methodology of combining individual-based seasonal movement data with temporally dynamic species distribution models provides a comprehensive approach to integrating multiple data types to describe broad-scale spatial patterns of animal movement. Further development and customization of this approach will continue to advance knowledge about the full annual cycle and conservation of migratory birds

Rationale and study design for a randomised controlled trial to reduce sedentary time in adults at risk of type 2 diabetes mellitus: project stand (Sedentary Time ANd diabetes)

<p>Abstract</p> <p>Background</p> <p>The rising prevalence of Type 2 Diabetes Mellitus (T2DM) is a major public health problem. There is an urgent need for effective lifestyle interventions to prevent the development of T2DM. Sedentary behaviour (sitting time) has recently been identified as a risk factor for diabetes, often independent of the time spent in moderate-to-vigorous physical activity. Project STAND (<it>Sedentary Time ANd Diabetes</it>) is a study which aims to reduce sedentary behaviour in younger adults at high risk of T2DM.</p> <p>Methods/Design</p> <p>A reduction in sedentary time is targeted using theory driven group structured education. The STAND programme is subject to piloting and process evaluation in line with the MRC framework for complex interventions. Participants are encouraged to self-monitor and self-regulate their behaviour. The intervention is being assessed in a randomised controlled trial with 12 month follow up. Inclusion criteria are a) aged 18-40 years with a BMI in the obese range; b) 18-40 years with a BMI in the overweight range plus an additional risk factor for T2DM. Participants are randomised to the intervention (n = 89) or control (n = 89) arm. The primary outcome is a reduction in sedentary behaviour at 12 months as measured by an accelerometer (count < 100/min). Secondary outcomes include physical activity, sitting/lying time using the ActivPAL posture monitor, fasting and 2 h oral glucose tolerance test, lipids, inflammatory biomarkers, body weight, waist circumference, blood pressure, illness perceptions, and efficacy beliefs for behaviour change.</p> <p>Conclusions</p> <p>This is the first UK trial to address sedentary behaviour change in a population of younger adults at risk of T2DM. The results will provide a platform for the development of a range of future multidisciplinary interventions in this rapidly expanding high-risk population.</p> <p>Trial registration</p> <p>Current controlled trials <a href="http://www.controlled-trials.com/ISRCTN08434554">ISRCTN08434554</a>, MRC project 91409.</p

Convergent genetic and expression data implicate immunity in Alzheimer's disease

Background Late–onset Alzheimer's disease (AD) is heritable with 20 genes showing genome wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease we extended these genetic data in a pathway analysis. Methods The ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain. Results ALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (p = 3.27×10-12 after multiple testing correction for pathways), regulation of endocytosis (p = 1.31×10-11), cholesterol transport (p = 2.96 × 10-9) and proteasome-ubiquitin activity (p = 1.34×10-6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected p 0.002 – 0.05). Conclusions The immune response, regulation of endocytosis, cholesterol transport and protein ubiquitination represent prime targets for AD therapeutics

Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease

We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

The development of a peer assisted learning model for the clinical education of physiotherapy students

Demand for clinical placements in physiotherapy education continues to outstrip supply. Peer assisted learning, in various formats, has been trialled to increase training capacity and facilitate student learning during clinical education. There are no documented examples of measurable or repeatable peer assisted learning models to aid clinicians in implementing these strategies. The aim of this research was to develop a repeatable and quantifiable peer assisted learning model of clinical education for paired undergraduate physiotherapy students. Additionally, the project aimed to evaluate the impact of clinician engagement in the model development process on their self-rated ability to facilitate peer assisted learning. A series of four workshops was conducted to facilitate development and refinement of a peer assisted learning model by physiotherapy clinical educators. The workshops introduced relevant peer learning principles and a range of clinically relevant educational tools to educators. Consensus was targeted on the tools and approaches that would underpin the peer assisted learning model. A survey investigating participants’ self-rated ability to facilitate components of peer assisted learning was administered prior to, and on completion of, the workshop series. Educators agreed on a model to facilitate student peer interaction in clinical reasoning, observation of performance, risk identification and mitigation, and feedback and coaching. Tools to evaluate student and clinical educator outcomes were developed. On completion of the workshops, participants reported significantly more confidence in their ability to facilitate peer assisted learning. Development of a peer assisted learning model of clinical education that is acceptable to clinical educators was achieved through stakeholder involvement from concept stage. Assessment of educator knowledge and confidence, combined with critical review of stakeholder feedback at multiple stages in model development, appeared effective in conveying ownership of the model to clinical educators and identifying the support required for confidence in facilitating peer assisted learning

Programme frequency, type, time and duration do not explain the effects of balance exercise in older adults:A systematic review with a meta-regression analysis

ObjectiveThe objective of this systematic review was to examine the effects of different balance exercise interventions compared with non-balance exercise controls on balance task performance in older adults.DesignSystematic review.Data sourcesMedline, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Scopus and Cochrane Database of Systematic Reviews were searched until July 2017.Eligibility criteria for selecting studiesSystematic reviews and meta-analyses of randomised trials of balance exercise interventions for older adults were identified for extraction of eligible randomised trials. Eligibility criteria for inclusion of randomised trials in meta-analyses were comparison of a balance exercise intervention with a control group that did not perform balance exercises, report of at least one end-intervention balance outcome measurement that was consistent with the five subgroups of balance exercise identified, and full-text article available in English.ResultsNinety-five trials were included in meta-analyses and 80 in meta-regressions. For four balance exercise types (control centre of mass, multidimensional, mobility and reaching), significant effects for balance exercise interventions were found in meta-analyses (standardised mean difference (SMD) 0.31–0.50), however with considerable heterogeneity in observed effects (I2: 50.4%–80.6%). Risk of bias assessments (Physiotherapy Evidence Database score and funnel plots) did not explain heterogeneity. One significant relationship identified in the meta-regressions of SMD and balance exercise frequency, time and duration explained 2.1% of variance for the control centre of mass subgroup.ConclusionLimitations to this study included the variability in design of balance interventions, incomplete reporting of data and statistical heterogeneity. The design of balance exercise programmes provides inadequate explanation of the observed benefits of these interventions.</jats:sec