Patterns in participation: Factors influencing parent attendance at two, centre-based early childhood interventions

Interventions training parents of at-risk children have received considerable empirical support but their effectiveness is undermined by low attendance rates. This research sought to clarify why parents, even with the best of intentions, fail to follow through to full participation in workshop programs; and to provide insight into ways to improve parental engagement. We examined participation in Parents as Partners, a school-based, early childhood intervention. Demographic and ongoing educational, social, emotional and behavioural data for 136 parent-child dyads were gathered from parents, teachers and children. Mitigation of a wide range of factors previously identified as barriers to attendance was also attempted. A post-intervention survey was conducted to examine parents’ insights into their attendance patterns. Overall, 91 parents attended and 44 failed to attend any workshops. Higher parent education and SEI, and better child language skills were good predictors of attendance (87%), but poor predictors of nonattendance (42%). Additionally, parent-child dyad profiles suggested that children of nonattending parents were more likely to benefit from workshop content than attenders’ children. Survey data suggested that attenders organised their schedules to facilitate follow-through but nonattenders were unable to do so. Family characteristics and practical reasons were central, interacting factors affecting attendance. Parental self-organisation appeared to moderate follow-through and to stem from lifestyle constraints related to lower SEI and parent education. This produced high nonattendance rates in parents of children who most needed support. It is urgent to discover to what extent innovative delivery platforms currently being explored (e.g., internet/social media) can improve parental engagement

Genetic diversity and potential responses of New Zealand Rotifera and Antarctic Collembola to environmental changes

Environmental changes can impact the diversity and abundance of biotic communities as well as their dispersal among geographic regions. The availability of sensitive molecular techniques has enabled assessments of diversity at levels previously unattainable and allowed investigation of how biota are influenced by their environment. This thesis examines the use of mitochondrial DNA sequence variation in New Zealand freshwater rotifers (Rotifera) and Antarctic springtails (Collembola) to assess diversity and determine responses to environmental changes. Using mitochondrial cytochrome c oxidase subunit I (COI) DNA sequences, I examined the diversity of New Zealand rotifers. The rotifer phylum is comprised of a variety of species and individuals are often abundant in freshwater systems globally. Species are associated with specific trophic states and in New Zealand are routinely monitored as biological indicators of ecosystem health. At present, species’ identification relies on morphological characters which is time consuming and requires appropriate taxonomic expertise. Here, I assessed the use of COI sequences as an alternative for the routine identification of New Zealand rotifers. A total of 177 individuals were sequenced from 45 morphologically-recognised taxa. High intraspecific variation was found among 14 species (3.4 - 39.0% divergence) and based on comparisons with sequences available on GenBank, 18 species were genetically distinct from their global conspecifics (>6.6% divergence). I conclude that these distinct haplotypes are potentially endemic among putatively cosmopolitan species. A better understanding of rotifer diversity in New Zealand will allow the detection and potential control of future non-indigenous species’ incursions. In order to assess the effects of environmental temperature changes on the genetic structure of populations, I examined the diversity of COI sequences of Antarctic springtails relative to the environmental conditions during which they were active. The target species, Gomphiocephalus hodgsoni, is known to harbour high genetic (COI) diversity as well as having considerable variation in their ability to tolerate sub-zero temperature – specifically, there appear to be “warm” and “cold” adapted individuals. I sequenced 151 individuals collected in pitfall traps near Spaulding Pond, Taylor Valley and found 19 unique COI haplotypes that separated into two distinct groups (1.6% divergence), with one haplotype group comprising 80% of the sequenced population. During two-hourly sampling, air temperature was the strongest predictor of activity between the two haplotype groups (R2 = 0.56) and when combined with subsurface soil temperature, relative humidity and photosynthetically active radiation, explanatory power increased to R2 = 0.71. Air temperatures are predicted to continue increasing across most of Antarctica which is expected to impact springtails by a detectable amount. Monitoring programmes focussed on the temporal and spatial changes in COI haplotype diversity may provide a sensitive measure of population responses to climate change. Collectively, these two studies contribute baseline data of the current genetic diversity and population structure among New Zealand rotifers and Antarctic springtails and provide a platform by which to monitor future environmental changes

Social mobility or social reproduction? A case study of the attainment patterns of students according to their social background and ethnicity

This paper explores levels of achievement amongst boys who attended a selective school in Birmingham, UK through consideration of their social background and ethnicity. It seeks to answer three main questions. Firstly, to what extent does academic attainment vary between students from different socio-economic groups and ethnic backgrounds? Secondly, what are the possible reasons for these variations? Thirdly, what can selective schools do to close the gaps in attainment between these groups? The study explores quantitative data of student attainment (n=625) to map areas of comparatively low achievement across the city of Birmingham. This map identifies areas of high vulnerability (HV) to poor performance, specifically by identifying the postcodes of neighbourhoods containing students who are most likely to underachieve. Qualitative data was also gathered amongst students (n=121) who were embarking on their General Certificate of Secondary Education (GCSE) studies. All were asked to single out factors that might affect their academic performance. These findings were then cross-referenced with the postcode study to help analyse possible reasons for under performance. The main finding of this research was that the study school experiences a distance-decay effect in relation to examination success. Boys from Black and Minority Ethnic (BME) groups generally performed worse than White British (WB) boys, while students from deprived areas of the city were also less likely to succeed. Students from poorer communities tend to live in environments of relatively low aspiration, although one inner city area was identified as anomalous with regard to the achievements of its students. We conclude that social reproduction, rather than social mobility, is occurring within the case study school and suggest a range of initiatives to raise the levels of achievement of those who are most socially disadvantaged

Subject-specific information enhances spatial accuracy of high-density diffuse optical tomography

Functional near-infrared spectroscopy (fNIRS) is a widely used imaging method for mapping brain activation based on cerebral hemodynamics. The accurate quantification of cortical activation using fNIRS data is highly dependent on the ability to correctly localize the positions of light sources and photodetectors on the scalp surface. Variations in head size and shape across participants greatly impact the precise locations of these optodes and consequently, the regions of the cortical surface being reached. Such variations can therefore influence the conclusions drawn in NIRS studies that attempt to explore specific cortical regions. In order to preserve the spatial identity of each NIRS channel, subject-specific differences in NIRS array registration must be considered. Using high-density diffuse optical tomography (HD-DOT), we have demonstrated the inter-subject variability of the same HD-DOT array applied to ten participants recorded in the resting state. We have also compared three-dimensional image reconstruction results obtained using subject-specific positioning information to those obtained using generic optode locations. To mitigate the error introduced by using generic information for all participants, photogrammetry was used to identify specific optode locations per-participant. The present work demonstrates the large variation between subjects in terms of which cortical parcels are sampled by equivalent channels in the HD-DOT array. In particular, motor cortex recordings suffered from the largest optode localization errors, with a median localization error of 27.4 mm between generic and subject-specific optodes, leading to large differences in parcel sensitivity. These results illustrate the importance of collecting subject-specific optode locations for all wearable NIRS experiments, in order to perform accurate group-level analysis using cortical parcellation

RARγ is critical for maintaining a balance between hematopoietic stem cell self-renewal and differentiation

Hematopoietic stem cells (HSCs) sustain lifelong production of all blood cell types through finely balanced divisions leading to self-renewal and differentiation. Although several genes influencing HSC self-renewal have been identified, to date no gene has been described that, when activated, enhances HSC self-renewal and, when activated, promotes HSC differentiation. We observe that the retinoic acid receptor (RAR)γ is selectively expressed in primitive hematopoietic precursors and that the bone marrow of RARγ knockout mice exhibit markedly reduced numbers of HSCs associated with increased numbers of more mature progenitor cells compared with wild-type mice. In contrast, RARα is widely expressed in hematopoietic cells, but RARα knockout mice do not exhibit any HSC or progenitor abnormalities. Primitive hematopoietic precursors overexpressing RARα differentiate predominantly to granulocytes in short-term culture, whereas those overexpressing RARγ exhibit a much more undifferentiated phenotype. Furthermore, loss of RARγ abrogated the potentiating effects of all-trans retinoic acid on the maintenance of HSCs in ex vivo culture. Finally, pharmacological activation of RARγ ex vivo promotes HSC self-renewal, as demonstrated by serial transplant studies. We conclude that the RARs have distinct roles in hematopoiesis and that RARγ is a critical physiological and pharmacological regulator of the balance between HSC self-renewal and differentiation

Keeping parents involved: Predicting attrition in a self-directed, online program for childhood conduct problems

Positive parenting programs have a strong evidence base for improving parent–child relationships, strengthening families, and reducing childhood behavior disturbances. Their reach is less than optimal however, with only a minority of families in need of help participating. Father involvement is particularly low. Online, self-directed programs have the potential to improve participation rates. This article examines risk factors for dropout/attrition from a free, evidence-based, self-directed, father-inclusive parenting program, Parentworks, which was made available across Australia. Parents (N = 2,967) enrolled in the program and completed preintervention questionnaires. There was a steady and consistent loss of participants through the sequence of core program modules, until a final sample of 218 completed the postintervention questionnaire. A range of demographic and parent and child variables were tested as predictors of 3 subgroups: nonstarters, partial completers, and full completers. Nonstarters (n = 1,625) tended to have older children with fewer behavioral problems and report higher psychopathology and dysfunctional parenting than those who partially (n = 1,124) or fully completed. Contrary to findings from face-to-face research, single parents had the highest completion rates. Coparticipation of partners and interparental conflict had no impact on completion rates. Fathers participated at relatively high levels. Results show that parents with the greatest need tend to engage with online programs, and online programs may be particularly useful for fathers, single parents, and those in conflicted relationships. Directions for future program design and research are discussed

Spatial and temporal scales matter when assessing the species and genetic diversity of springtails (Collembola) in Antarctica

Seven species of springtail (Collembola) are present in Victoria Land, Antarctica and all have now been sequenced at the DNA barcoding region of the mitochondrial cytochrome c oxidase subunit I gene (COI). Here, we review these sequence data (n = 930) from the GenBank and Barcode of Life Datasystems (BOLD) online databases and provide additional, previously unpublished sequences (n = 392) to assess the geographic distribution of COI variants across all species. Four species (Kaylathalia klovstadi, Cryptopygus cisantarcticus, Friesea grisea, and Cryptopygus terranovus) are restricted to northern Victoria Land and three (Antarcticinella monoculata, Cryptopygus nivicolus, and Gomphiocephalus hodgsoni) are found only in southern Victoria Land, the two biogeographic zones which are separated by the vicinity of the Drygalski Ice Tongue. We found highly divergent lineages within all seven species (range 1.7–14.7%) corresponding to different geographic locations. Levels of genetic divergence for the southern Victoria Land species G. hodgsoni, the most widespread species (~27,000 km2), ranged from 5.9 to 7.3% divergence at sites located within 30 km, but separated by glaciers. We also found that the spatial patterns of genetic divergence differed between species. For example, levels of divergence were much higher for C. terranovus (>10%) than for F. grisea (5%) populations and over 87% of the total genetic variation (based on AMOVA) on either side of a single, 16 km width glacier. Collectively, these data provide evidence for limited dispersal opportunities among populations of springtails due to geological and glaciological barriers (e.g., glaciers and ice tongues). Some locations harbored highly genetically divergent populations and these areas are highlighted from a conservation perspective such as avoidance of human-mediated transport between sites. We conclude that species-specific spatial and temporal scales need to be considered when addressing ecological and physiological questions as well as conservation strategies for Antarctic Collembola

Genetic diversity among populations of Antarctic springtails (Collembola) within the Mackay Glacier ecotone

Climate changes are likely to have major influences on the distribution and abundance of Antarctic terrestrial biota. To assess arthropod distribution and diversity within the Ross Sea region, we examined mitochondrial DNA (COI) sequences for three currently recognized species of springtail (Collembola) collected from sites in the vicinity, and to the north of, the Mackay Glacier (77°S). This area acts as a transition between two biogeographic regions (northern and southern Victoria Land). We found populations of highly divergent individuals (5%–11.3% intraspecific sequence divergence) for each of the three putative springtail species, suggesting the possibility of cryptic diversity. Based on molecular clock estimates, these divergent lineages are likely to have been isolated for 3–5 million years. It was during this time that the Western Antarctic Ice Sheet (WAIS) was likely to have completely collapsed, potentially facilitating springtail dispersal via rafting on running waters and open seaways. The reformation of the WAIS would have isolated newly established populations, with subsequent dispersal restricted by glaciers and ice-covered areas. Given the currently limited distributions for these genetically divergent populations, any future changes in species’ distributions can be easily tracked through the DNA barcoding of springtails from within the Mackay Glacier ecotone