Oscillating bounce solutions and vacuum tunneling in de Sitter spacetime

We study a class of oscillating bounce solutions to the Euclidean field equations for gravity coupled to a scalar field theory with two, possibly degenerate, vacua. In these solutions the scalar field crosses the top of the potential barrier $k>1$ times. Using analytic and numerical methods, we examine how the maximum allowed value of $k$ depends on the parameters of the theory. For a wide class of potentials $k_{\rm max}$ is determined by the value of the second derivative of the scalar field potential at the top of the barrier. However, in other cases, such as potentials with relatively flat barriers, the determining parameter appears instead to be the value of this second derivative averaged over the width of the barrier. As a byproduct, we gain additional insight into the conditions under which a Coleman-De Luccia bounce exists. We discuss the physical interpretation of these solutions and their implications for vacuum tunneling transitions in de Sitter spacetime.Comment: 31 pages, 11 figure

EFFICACY OF HERBIVORE EXCLUSION ON PLANTED TREE SEEDLING VITALITY ON A RECLAIMED SURFACE MINE IN EASTERN KENTUCKY

Conventional Appalachian surface-mine reclamation techniques repress natural forest regeneration, and tree plantings are often necessary for reforestation. Reclaimed Appalachian surface mines harbor a suite of mammal herbivores that forage on recently planted seedlings. Anecdotal reports across Appalachia have implicated herbivory in the hindrance and failure of reforestation efforts, yet empirical evaluation of herbivory impacts on planted seedling vitality in this region remains relatively uninitiated. First growing-season survival, height growth, and mammal herbivory damage of black locust (Robinia pseudoacacia L.), shortleaf pine (Pinus echinata Mill.), and white oak (Quercus alba L.) are presented in response to varying intensities of herbivore exclusion. Seedling survival was generally high, and height growth was positive for all species. The highest herbivory incidence of all tree species was observed in treatments offering no herbivore exclusion. While seedling protectors lowered herbivory incidence compared with no exclusion, full exclusion treatments resulted in the greatest reduction of herbivore damage. Although herbivory from rabbits, small mammals, and domestic animals was observed, cervids (deer and elk) were responsible for 95.8% of all damaged seedlings. This study indicates that cervids forage heavily on planted seedlings during the first growing-season, but exclusion and tree species selection is effective at reducing herbivory

Forest Development over a Twenty-Year Chronosequence of Reforested Urban Sites

Urbanization causes a variety of negative ecological impacts, impairing forests, streams, and other ecosystems. While urban forests are the subject of increasing research attention, planted urban forests are less well-understood than remnant forests; however, these systems may be distinct in terms of ecosystem structure and function. The current study investigates a chronosequence of reforested urban sites in Lexington, KY, USA, with a focus on overstory and understory woody plant community characteristics. Monitoring plots were established in each of the 20 sites; tree height, dbh, and species were surveyed for the overstory, and species and height were surveyed for the understory. Canopy height increased non-linearly with time since planting, rapidly increasing in years 6–10, but remaining relatively steady after year 15. While the overstory was dominated by planted native species, the understory was predominately non-native species, some of which are considered invasive. Overall, the nonlinear logistic relationship of canopy height to time since planting may be driven by species-specific effects—with trees such as ash (Fraxinus spp. L.) and black locust (Robinia pseudoacacia L.) important during the early years after planting, but declining over time due to pests and other pressures. Alternatively, this complex relationship of canopy height with time may be driven by uncontrolled factors such as site quality, landscape position, planted species, etc. The significance of invasive species in the understory suggests that the long-term health of these sites will be compromised without intentional ongoing maintenance to ensure continued forest development toward desired native community characteristics

First-Year Vitality of Reforestation Plantings in Response to Herbivore Exclusion on Reclaimed Appalachian Surface-Mined Land

Conventional Appalachian surface-mine reclamation techniques repress natural forest regeneration, and tree plantings are often necessary for reforestation. Reclaimed Appalachian surface mines harbor a suite of mammal herbivores that forage on recently planted seedlings. Anecdotal reports across Appalachia have implicated herbivory in the hindrance and failure of reforestation efforts, yet empirical evaluation of herbivory impacts on planted seedling vitality in this region remains relatively uninitiated. First growing-season survival, height growth, and mammal herbivory damage of black locust (Robinia pseudoacacia L.), shortleaf pine (Pinus echinata Mill.), and white oak (Quercus alba L.) are presented in response to varying intensities of herbivore exclusion. Seedling survival was generally high, and height growth was positive for all species. The highest herbivory incidence of all tree species was observed in treatments offering no herbivore exclusion. While seedling protectors lowered herbivory incidence compared with no exclusion, full exclusion treatments resulted in the greatest reduction of herbivore damage. Although herbivory from rabbits, small mammals, and domestic animals was observed, cervids (deer and elk) were responsible for 95.8% of all damaged seedlings. This study indicates that cervids forage heavily on planted seedlings during the first growing-season, but exclusion is effective at reducing herbivory

Coleman - de Luccia instanton of the second order in a brane world

The second order Coleman - de Luccia instanton and its action in the Randall - Sundrum type II model are investigated and the comparison with the results in Einstein's general relativity is done in the present paper.Comment: 4 pages, accepted in IJT

The Skyrme Energy Functional and Naturalness

Recent studies show that successful relativistic mean-field models of nuclei are consistent with naive dimensional analysis and naturalness, as expected in low-energy effective field theories of quantum chromodynamics. The nonrelativistic Skyrme energy functional is found to have similar characteristics.Comment: 8 pages, REVTeX 3.0 with epsf.sty, plus 2 figure

Enhancing the early home learning environment through a brief group parenting intervention: study protocol for a cluster randomised controlled trial.

BACKGROUND: The quality of the home learning environment has a significant influence on children's language and communication skills during the early years with children from disadvantaged families disproportionately affected. This paper describes the protocol and participant baseline characteristics of a community-based effectiveness study. It evaluates the effects of 'smalltalk', a brief group parenting intervention (with or without home coaching) on the quality of the early childhood home learning environment. METHODS/DESIGN: The study comprises two cluster randomised controlled superiority trials (one for infants and one for toddlers) designed and conducted in parallel. In 20 local government areas (LGAs) in Victoria, Australia, six locations (clusters) were randomised to one of three conditions: standard care (control); smalltalk group-only program; or smalltalk plus (group program plus home coaching). Programs were delivered to parents experiencing socioeconomic disadvantage through two existing age-based services, the maternal and child health service (infant program, ages 6-12 months), and facilitated playgroups (toddler program, ages 12-36 months). Outcomes were assessed by parent report and direct observation at baseline (0 weeks), post-intervention (12 weeks) and follow-up (32 weeks). Primary outcomes were parent verbal responsivity and home activities with child at 32 weeks. Secondary outcomes included parenting confidence, parent wellbeing and children's communication, socio-emotional and general development skills. Analyses will use intention-to-treat random effects ("multilevel") models to account for clustering. RECRUITMENT AND BASELINE DATA: Across the 20 LGAs, 986 parents of infants and 1200 parents of toddlers enrolled and completed baseline measures. Eighty four percent of families demonstrated one or more of the targeted risk factors for poor child development (low income; receives government benefits; single, socially isolated or young parent; culturally or linguistically diverse background). DISCUSSION: This study will provide unique data on the effectiveness of a brief group parenting intervention for enhancing the early home learning environment of young children from disadvantaged families. It will also provide evidence of the extent to which additional one-on-one support is required to achieve change and whether there are greater benefits when delivered in the 1st year of life or later. The program has been designed for scale-up across existing early childhood services if proven effective. TRIAL REGISTRATION: 8 September 2011; ACTRN12611000965909 .This research was commissioned and funded by the Victorian Government Department of Education and Early Childhood (now the Department of Education and Training, DET). JN, MT, SB, TH, VH, EW and NH were employees of the Parenting Research Centre when this study was designed and conducted. JN, SB, EW & NH are currently supported by the Australian Communities Foundation through the Roberta Holmes Transition to Contemporary Parenthood Program (Coronella sub-fund); EW was part-funded by the Centre for Research Excellence in Child Language at Murdoch Children’s Research Institute (NHMRC grant 1023493). OU is funded by the UK National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula at the Royal Devon and Exeter NHS Foundation Trust. The views expressed in this publication are those of the authors and not necessarily those of the funding bodies

Impact of a brief group intervention to enhance parenting and the home learning environment for children aged 6-36 months: A cluster randomised controlled trial

This is the final version of the article. Available from the publisher via the DOI in this record.This study evaluated the effectiveness of a group parenting intervention designed to strengthen the home learning environment of children from disadvantaged families. Two cluster randomised controlled superiority trials were conducted in parallel and delivered within existing services: a 6-week parenting group (51 locations randomised; 986 parents) for parents of infants (aged 6-12 months), and a 10-week facilitated playgroup (58 locations randomised; 1200 parents) for parents of toddlers (aged 12-36 months). Each trial had three conditions: intervention (smalltalk group-only); enhanced intervention with home coaching (smalltalk plus); and 'standard'/usual practice controls. Parent-report and observational measures were collected at baseline, 12 and 32 weeks follow-up. Primary outcomes were parent verbal responsivity and home learning activities at 32 weeks. In the infant trial, there were no differences by trial arm for the primary outcomes at 32 weeks. In the toddler trial at 32-weeks, participants in the smalltalk group-only trial showed improvement compared to the standard program for parent verbal responsivity (effect size (ES) = 0.16; 95% CI 0.01, 0.36) and home learning activities (ES = 0.17; 95% CI 0.01, 0.38) but smalltalk plus did not. For the secondary outcomes in the infant trial, several initial differences favouring smalltalk plus were evident at 12 weeks, but not maintained to 32 weeks. For the toddler trial, differences in secondary outcomes favouring smalltalk plus were evident at 12 weeks and maintained to 32 weeks. These trials provide some evidence of the benefits of a parenting intervention focused on the home learning environment for parents of toddlers but not infants. TRIAL REGISTRATION: 8 September 2011; ACTRN12611000965909 .This research was commissioned and funded by the Victorian Government Department of Education and Early Childhood Development (DEECD), and designed and conducted at the Parenting Research Centre. NH, EW, SB, AS, MT, MY and JN were employees of the Parenting Research Centre when this study was conducted. EW was part-funded by the Centre for Research Excellence in Child Language at Murdoch Childrens Research Institute (NHMRC grant 1023493). NH, EW, SB and JN are funded by the Australian Communities Foundation (Coronella sub-fund) at La Trobe University. OU is supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula at the Royal Devon and Exeter NHS Foundation Trust. Views expressed are those of the authors and not necessarily those of DEECD, NIHR, NHS or the Department of Health

The agreement between parent-reported and directly measured child language and parenting behaviors

Parenting behaviors are commonly targeted in early interventions to improve children\u27s language development. Accurate measurement of both parenting behaviors and children\u27s language outcomes is thus crucial for sensitive assessment of intervention outcomes. To date, only a small number of studies have compared parent-reported and directly measured behaviors, and these have been hampered by small sample sizes and inaccurate statistical techniques, such as correlations. The Bland-Altman Method and Reduced Major Axis regression represent more reliable alternatives because they allow us to quantify fixed and proportional bias between measures. In this study, we draw on data from two Australian early childhood cohorts (N = 201 parents and slow-to-talk toddlers aged 24 months; and N = 218 parents and children aged 6-36 months experiencing social adversity) to (1) examine agreement and quantify bias between parent-reported and direct measures, and (2) to determine socio-demographic predictors of the differences between parent-reported and direct measures. Measures of child language and parenting behaviors were collected from parents and their children. Our findings support the utility of the Bland-Altman Method and Reduced Major Axis regression in comparing measurement methods. Results indicated stronger agreement between parent-reported and directly measured child language, and poorer agreement between measures of parenting behaviors. Child age was associated with difference scores for child language; however, the direction varied for each cohort. Parents who rated their child\u27s temperament as more difficult tended to report lower language scores on the parent questionnaire, compared to the directly measured scores. Older parents tended to report lower parenting responsiveness on the parent questionnaire, compared to directly measured scores. Finally, speaking a language other than English was associated with less responsive parenting behaviors on the videotaped observation compared to the parent questionnaire. Variation in patterns of agreement across the distribution of scores highlighted the importance of assessing agreement comprehensively, providing strong evidence that simple correlations are grossly insufficient for method comparisons. We discuss implications for researchers and clinicians, including guidance for measurement selection, and the potential to reduce financial and time-related expenses and improve data quality. Further research is required to determine whether findings described here are reflected in more representative populations