Symbolic play provides a fertile context for language development

In this study we test the hypothesis that symbolic play represents a fertile context for language acquisition because its inherent ambiguity elicits communicative behaviours that positively influence development. Infant-caregiver dyads (N = 54) participated in two 20-minute play sessions six months apart (Time 1 = 18 months, Time 2 = 24 months). During each session the dyads played with two sets of toys that elicited either symbolic or functional play. The sessions were transcribed and coded for several features of dyadic interaction and speech; infants’ linguistic proficiency was measured via parental report. The two play contexts resulted in different communicative and linguistic behaviour. Notably, the symbolic play condition resulted in significantly greater conversational turn-taking than functional play, and also resulted in the greater use of questions and mimetics in infant-directed speech (IDS). In contrast, caregivers used more imperative clauses in functional play. Regression analyses showed that unique properties of symbolic play (i.e., turn-taking, yes-no questions, mimetics) positively predicted children’s language proficiency, whereas unique features of functional play (i.e., imperatives in IDS) negatively predicted proficiency. The results provide evidence in support of the hypothesis that symbolic play is a fertile context for language development, driven by the need to negotiate meaning

Ejection of Supernova-Enriched Gas From Dwarf Disk Galaxies

We examine the efficiency with which supernova-enriched gas may be ejected from dwarf disk galaxies, using a methodology previously employed to study the self-enrichment efficiency of dwarf spheroidal systems. Unlike previous studies that focused on highly concentrated starbursts, in the current work we consider discrete supernova events spread throughout various fractions of the disk. We model disk systems having gas masses of 10^8 and 10^9 solar masses with supernova rates of 30, 300, and 3000 per Myr. The supernova events are confined to the midplane of the disk, but distributed over radii of 0, 30, and 80% of the disk radius, consistent with expectations for Type II supernovae. In agreement with earlier studies, we find that the enriched material from supernovae is largely lost when the supernovae are concentrated near the nucleus, as expected for a starburst event. In contrast, however, we find the loss of enriched material to be much less efficient when the supernovae occur over even a relatively small fraction of the disk. The difference is due to the ability of the system to relax following supernova events that occur over more extended regions. Larger physical separations also reduce the likelihood of supernovae going off within low-density "chimneys" swept out by previous supernovae. We also find that, for the most distributed systems, significant metal loss is more likely to be accompanied by significant mass loss. A comparison with theoretical predications indicates that, when undergoing self-regulated star formation, galaxies in the mass range considered shall efficiently retain the products of Type II supernovae.Comment: 16 pages, 14 figures, to appear in Astrophysical Journal; higher resolution figures available through Ap

Language, culture, and group membership: An investigation into the social effects of colloquial Australian English

Languages are strong markers of social identity. Multiple features of language and speech, from accent to lexis to grammatical constructions, mark speakers as members of specific cultural groups. In the current article, we present two confederate-scripted studies that investigated the social effects of the Australian hypocoristic use (e.g., uggie, uni, derro)—a lexical category emblematic of Australian culture. Participants took turns with a confederate directing each other through locations on a map. In their directions, the confederate used either hypocoristic (e.g., uni) or standard forms (e.g., university). The confederate’s cultural group membership and member prototypicality were manipulated by ethnic background and accent: In a highly prototypical in-group condition, the confederate had an Anglo-Celtic background and Australian English (AusE) accent; in a low prototypical in-group condition, the confederate had an Asian background and AusE accent; and in the out-group condition, the confederate had an Asian background and non-AusE accent. Hypocoristic use resulted in significantly higher participant-rated perceived common ground with the confederate when the confederate was an in-group but not an out-group member, which in some instances was moderated by in-group identification. The results suggest that like accents, culturally significant lexical categories function as markers of in-group identity, which influence perceived social closeness during interaction

The Role of Attenuation and Land Management in Small Catchments to Remove Sediment and Phosphorus: A Modelling Study of Mitigation Options and Impacts

It is well known that soil, hillslopes, and watercourses in small catchments possess a degree of natural attenuation that affects both the shape of the outlet hydrograph and the transport of nutrients and sediments. The widespread adoption of Natural Based Solutions (NBS) practices in the headwaters of these catchments is expected to add additional attenuation primarily through increasing the amount of new storage available to accommodate flood flows. The actual type of NBS features used to add storage could include swales, ditches, and small ponds (acting as sediment traps). Here, recent data collected from monitored features (from the Demonstration Test Catchments project in the Newby Beck catchment (Eden) in northwest England) were used to provide first estimates of the percentages of the suspended sediment (SS) and total phosphorus (TP) loads that could be trapped by additional features. The Catchment Runoff Attenuation Flux Tool (CRAFT) was then used to model this catchment (Newby Beck) to investigate whether adding additional attenuation, along with the ability to trap and retain SS (and attached P), will have any effect on the flood peak and associated peak concentrations of SS and TP. The modelling tested the hypothesis that increasing the amount of new storage (thus adding attenuation capacity) in the catchment will have a beneficial effect. The model results implied that a small decrease of the order of 5–10% in the peak concentrations of SS and TP was observable after adding 2000 m3 to 8000 m3 of additional storage to the catchmen

Climate change mitigation for agriculture: water quality benefits and costs

New Zealand is unique in that half of its national greenhouse gas (GHG) inventory derives from agriculture--predominantly as methane (CH4) and nitrous oxide (N2O), in a 2:1 ratio. The remaining GHG emissions predominantly comprise carbon dioxide (CO2) deriving  from  energy  and  industry  sources.  Proposed strategies to  mitigate  emissions  of  CH4  and  N2O  from  pastoral  agriculture in New Zealand are: (1) utilising extensive and riparian afforestation of pasture to achieve CO2 uptake (carbon sequestration); (2) management of nitrogen through budgeting and/or the use of nitrification inhibitors, and minimising soil anoxia to reduce N2O emissions; and (3) utilisation of alternative waste treatment technologies to minimise emissions of CH4. These mitigation measures have associated co-benefits and co-costs (disadvantages) for rivers, streams and lakes because they affect land use, runoff loads, and receiving water and habitat quality. Extensive afforestation results in lower specific yields (exports) of nitrogen (N), phosphorus (P), suspended sediment (SS) and faecal matter and also has benefits for stream habitat quality by improving stream temperature, dissolved oxygen and pH regimes through greater shading, and the supply of woody debris and terrestrial food resources. Riparian afforestation does not achieve the same reductions in exports as extensive afforestation but can achieve reductions in concentrations of N, P, SS and faecal organisms. Extensive afforestation of pasture leads to reduced water yields and stream flows. Both afforestation measures produce intermittent disturbances to waterways during forestry operations (logging and thinning), resulting in sediment release from channel re-stabilisation and localised flooding, including formation of debris dams at culverts. Soil and fertiliser management benefits aquatic ecosystems by reducing N exports but the use of nitrification inhibitors, viz. dicyandiamide (DCD), to achieve this may under some circumstances impair wetland function to intercept and remove nitrate from drainage water, or even add to the overall N loading to waterways. DCD is water soluble and degrades rapidly in warm soil conditions. The recommended application rate of 10 kg DCD/ha corresponds to 6 kg N/ha and may be exceeded in warm climates. Of the N2O produced by agricultural systems, approximately 30% is emitted from indirect sources, which are waterways draining agriculture. It is important therefore to focus strategies for managing N inputs to agricultural systems generally to reduce inputs to wetlands and streams where these might be reduced to N2O. Waste management options include utilising the CH4 resource produced in farm waste treatment ponds as a source of energy, with conversion to CO2 via combustion achieving a 21-fold reduction in GHG emissions. Both of these have co-benefits for waterways as a result of reduced loadings. A conceptual model derived showing the linkages between key land management practices for greenhouse gas mitigation and key waterway values and ecosystem attributes is derived to aid resource managers making decisions affecting waterways and atmospheric GHG emissions

Gauge Problem in the Gravitational Self-Force II. First Post Newtonian Force under Regge-Wheeler Gauge

We discuss the gravitational self-force on a particle in a black hole space-time. For a point particle, the full (bare) self-force diverges. It is known that the metric perturbation induced by a particle can be divided into two parts, the direct part (or the S part) and the tail part (or the R part), in the harmonic gauge, and the regularized self-force is derived from the R part which is regular and satisfies the source-free perturbed Einstein equations. In this paper, we consider a gauge transformation from the harmonic gauge to the Regge-Wheeler gauge in which the full metric perturbation can be calculated, and present a method to derive the regularized self-force for a particle in circular orbit around a Schwarzschild black hole in the Regge-Wheeler gauge. As a first application of this method, we then calculate the self-force to first post-Newtonian order. We find the correction to the total mass of the system due to the presence of the particle is correctly reproduced in the force at the Newtonian order.Comment: Revtex4, 43 pages, no figure. Version to be published in PR

Links between climate change mitigation, adaptation and development in land policy and ecosystem restoration projects: lessons from South Africa

Links between climate change adaptation, mitigation and development co-benefits in land policy and ecosystem restoration projects are hampered by limited understanding of how multi-faceted policy, institutions and projects interact. This paper explores perceptions of co-benefits produced by two community-level projects that pursue ecosystem restoration in South Africa. It develops a new analytical framework to assess the enabling and constraining factors in delivering triple wins for adaptation, mitigation and development. The aim is to investigate the potential for integrating community perspectives into policy and project development and implementation. Data collected through mixed-methods (policy analysis, semi-structured interviews, participatory site visits and focus groups) are analysed using thematic analysis. We find that while the projects investigated have potential to deliver triple wins, siloed approaches presently hinder effective implementation. In particular, project focus on job creation hampers the achievement of longer-term mitigation and adaptation benefits. Operational flexibility, long-term goals, multi-sectoral cooperation and enabling frameworks are imperative to the achievement of triple wins. Findings provide valuable lessons that can be applied across sub-Saharan Africa towards achieving triple wins in climate and development policy and practice, especially those developed with job creation and ecological restoration aims

Kin against kin: internal co-selection and the coherence of kinship typologies

Across the world people in different societies structure their family relationships in many different ways. These relationships become encoded in their languages as kinship terminology, a word set that maps variably onto a vast genealogical grid of kinship categories, each of which could in principle vary independently. But the observed diversity of kinship terminology is considerably smaller than the enormous theoretical design space. For the past century anthropologists have captured this variation in typological schemes with only a small number of model system types. Whether those types exhibit the internal co-selection of parts implicit in their use is an outstanding question, as is the sufficiency of typologies in capturing variation as a whole. We interrogate the coherence of classic kinship typologies using modern statistical approaches and systematic data from a new database, Kinbank. We first survey the canonical types and their assumed patterns of internal and external co-selection, then present two data-driven approaches to assess internal coherence. Our first analysis reveals that across parents’ and ego’s (one’s own) generation, typology has limited predictive value: knowing the system in one generation does not reliably predict the other. Though we detect limited co-selection between generations, “disharmonic” systems are equally common. Second, we represent structural diversity with a novel multidimensional approach we term kinship space. This approach reveals, for ego’s generation, some broad patterning consistent with the canonical typology, but diversity (and mixed systems) is considerably higher than classical typologies suggest. Our results strongly challenge the descriptive adequacy of the set of canonical kinship types.Introduction Classic Typologies of Kinship - Hawaiian - Eskimo - Dravidian Systems - Sudanese Systems - Crow/Omaha - The Classic Typology: Recap Our Database - Languages - Kin Types Testing Typological Cohesion: Clearing the Ground with New Data Testing Typological Cohesion: Introducing New Methods - Creating the Kinship Space - Interpreting the Kinship Space -- Cluster Identification -- Eskimo -- Cross-parallal and Sudanese -- Hawaiian Conclusions: On the Internal Coherence of Canonical Type