Phenomenon of Interest, Framework, or Theory? Building Better Explanations in Community Psychology

Theories are a fundamental part of research. They provide guidance for the development of research questions and testable hypotheses as well as inform study methods and designs. However, in this issue, Jason, Stevens, Ram, Miller, Beasley, and Gleason (2016) raise important questions including: Are prominent “theories” in community psychology really theories? How useful are these “theories” for developing specific predictions and testable hypotheses? And, how can the field continue to develop and test theories that promote its agenda of social change? To answer these questions, Jason et al. (2016) identify and evaluate three “prominent theories” in community psychology – the ecological perspective (Kelly, 1968), psychological sense of community theory (Sarason, 1974), and empowerment (Rappaport, 1981). Based on their evaluation, they “conclude that community psychology theories have tended to function as frameworks” (p.  2). That is, these “theories” provide general guidance for what elements to study but fall short of offering specific predictions about the relationships between these elements. Jason et al (2016) conclude that the lack of predictive and explanatory theories in community psychology hinders progress in both the research development of explanatory mechanisms of social change as well as practice initiatives to promote social change. However, despite these major contributions, in this response I contend that the “prominent theories” identified by Jason et al (2016) were never intended to be theories in the first place. While Jason et al (2016) are right to call for more application of theory in community psychology, I provide a more optimistic view of the field’s current use of theory.&nbsp

Phenomenon of Interest, Framework, or Theory? Building Better Explanations in Community Psychology

Theories are a fundamental part of research. They provide guidance for the development of research questions and testable hypotheses as well as inform study methods and designs. However, in this issue, Jason, Stevens, Ram, Miller, Beasley, and Gleason (2016) raise important questions including: Are prominent “theories” in community psychology really theories? How useful are these “theories” for developing specific predictions and testable hypotheses? And, how can the field continue to develop and test theories that promote its agenda of social change? To answer these questions, Jason et al. (2016) identify and evaluate three “prominent theories” in community psychology – the ecological perspective (Kelly, 1968), psychological sense of community theory (Sarason, 1974), and empowerment (Rappaport, 1981). Based on their evaluation, they “conclude that community psychology theories have tended to function as frameworks” (p.  2). That is, these “theories” provide general guidance for what elements to study but fall short of offering specific predictions about the relationships between these elements. Jason et al (2016) conclude that the lack of predictive and explanatory theories in community psychology hinders progress in both the research development of explanatory mechanisms of social change as well as practice initiatives to promote social change. However, despite these major contributions, in this response I contend that the “prominent theories” identified by Jason et al (2016) were never intended to be theories in the first place. While Jason et al (2016) are right to call for more application of theory in community psychology, I provide a more optimistic view of the field’s current use of theory.&nbsp

Network selection and influence effects on children's and adolescents’ internalizing behaviors and peer victimization:A systematic review

In interpersonal models of developmental psychopathology, friendships and affiliations with peers have been considered as both consequences and determinants of children's and adolescents’ internalizing behaviors and peer victimization. Longitudinal stochastic actor-oriented models (SAOMs) allow developmental researchers to disentangle peer selection processes where children or adolescents choose friends who are similar to themselves in internalizing behaviors or peer victimization from peer influence processes where children or adolescents become more similar to their friends over time in internalizing behaviors or peer victimization. This paper highlights the methods and results from a systematic review that screened 1447 empirical articles and located 28 using SAOMs to understand the interplay between peer social networks and internalizing behaviors or peer victimization. The results provide some evidence for both peer selection and influence related to depression, social anxiety, and peer victimization. Additionally, the results provide insight into directions for additional substantive and methodological research. Based on the findings of this review, future research is recommended that considers specific tests of peer selection and influence mechanisms, developmental and gender differences, individual and contextual moderators, multiplex relationships, methodological quality, and direct replication of prior studies

Stochastic Degree Sequence Model with Edge Constraints (SDSM-EC) for Backbone Extraction

It is common to use the projection of a bipartite network to measure a unipartite network of interest. For example, scientific collaboration networks are often measured using a co-authorship network, which is the projection of a bipartite author-paper network. Caution is required when interpreting the edge weights that appear in such projections. However, backbone models offer a solution by providing a formal statistical method for evaluating when an edge in a projection is statistically significantly strong. In this paper, we propose an extension to the existing Stochastic Degree Sequence Model (SDSM) that allows the null model to include edge constraints (EC) such as prohibited edges. We demonstrate the new SDSM-EC in toy data and empirical data on young children's' play interactions, illustrating how it correctly omits noisy edges from the backbone

Environmental Impact of the Pre-Columbian Geoglyph Builders of Western Amazonia

A debate that has received much attention in recent years is the nature and scale of pre-Columbian impact in the Amazon lowlands. While the notion that Amazonia is a “pristine wilderness" has long been debunked, several papers have proposed that human impact in western regions was more sporadic and on a smaller scale than impacts in central and eastern regions, and that western Amazonia supported sparse pre-Columbian populations. The discovery of over 400 geometrically-patterned earthworks (geoglyphs) in the western Brazilian Amazon, which until recently lay under in-tact tropical forest, has raised important questions about the kind of societies that built them and the impact that they had on the terra firme upland landscapes. This study represents the very first investigations into human-environment interactions in the geoglyph region. By analysing phytoliths, charcoal and stable carbon isotopes from a series of soil profiles in the vicinities of two well-dated and excavated geoglyph sites, this study aims to discern the nature of the environment before, during and after the construction and use of the sites, and the spatial and temporal scales of landscape transformations that were effected by the geoglyph cultures. The data call for a re-appraisal of what is meant by “scales" of human impact in Amazonia, and propose that an understanding of the diversity of human-environment interactions must be considered through studies that closely combine regionally-sensitive archaeological and palaeoecological data.AHRCNCR

The impact of a native hemiparasite on a major invasive shrub is affected by host size at time of infection.

Few studies have examined how parasite impact is affected by host size. In a glasshouse experiment, we investigated the impact of the Australian native hemiparasitic vine, Cassytha pubescens, on a major invasive shrub, Ulex europaeus, of different sizes. Infected plants had significantly lower total, shoot and root biomass, but the parasite's impact was more severe on small than large hosts. When infected small but not large hosts had significantly lower nodule biomass. Irrespective of size, infection significantly decreased host shoot/root ratio, predawn and midday quantum yields, maximum electron transport rates and carbon isotope composition, and host nodule biomass g-1 root biomass significantly increased in response to infection. Infection did not affect host foliar nitrogen concentration or midday shoot water potential. Parasite biomass was significantly lower on small relative to large hosts, but was similar g-1 host total biomass. Parasite stem nitrogen, phosphorous and potassium concentration were significantly greater when C. pubescens was growing on small than large hosts. Our results clearly show that C. pubescens strongly decreases performance of this major invasive shrub, especially when hosts are small. This suggests that C. pubescens could be used most effectively as a native biocontrol when deployed on smaller hosts

Direct 3D printing of polymers onto textiles: Experimental studies and applications

© Emerald Group Publishing Limited. Purpose - The purpose of this paper is to investigate the adhesion of polymer materials printed directly onto fabrics using entry-level fused deposition modelling (FDM) machines. A series of functional and decorative parts were designed to explore the limitations and to identify potential applications. Design/methodology/approach - A series of shapes and structures were designed as 3D computer-aided design (CAD) solids to determine whether complex parts could be printed directly onto the surface of fabrics. The structures were fabricated using an entry-level FDM printer with acrylonitrile butadiene styrene, polylactic acid (PLA) and nylon on eight different types of synthetic and man-made woven and knit fabrics. The results were recorded according to four parameters - the warp, bond, print quality and flex - before comparing the data sets. Findings - Among the three polymers, PLA showed the best results when printed on the eight different types of fabrics, having extremely good adhesion with little warp, yet displaying a high quality of print with good flexural strength. For the fabrics, woven cotton, woven polywool and knit soy had excellent adhesion when the three polymers were deposited. Research limitations/implications - Future work should cover a wider range of polymers and textiles and incorporate more functional features for testing. Other aspects include modifying the fibre surface through mechanical or chemical means to achieve a more efficient adhesion with the fibre and examining the deposition process in terms of temperature, pressure and build density. Future work should also investigate the feasibility for large-scale production. Practical implications - This paper supports work on wearable electronics by integrating comfortable textiles with hard wearing parts without compromising on quality and fit and combining additive manufacturing processes with textiles to maintain the drape characteristics of the fabric. Polymer-textile deposition will contribute to new applications and functional products such as orthopaedic braces for medical use or for decorative features such as buttons and trimmings for garments. Originality/value - This paper has contributed to new knowledge by providing a better understanding of polymer materials being printed directly onto fabrics using entry-level FDM machines

Environmental impact of geometric earthwork construction in pre-Columbian Amazonia

There is considerable controversy over whether pre-Columbian (pre-A.D. 1492) Amazonia was largely “pristine” and sparsely populated by slash-and-burn agriculturists, or instead a densely populated, domesticated landscape, heavily altered by extensive deforestation and anthropogenic burning. The discovery of hundreds of large geometric earthworks beneath intact rainforest across southern Amazonia challenges its status as a pristine landscape, and has been assumed to indicate extensive pre-Columbian deforestation by large populations. We tested these assumptions using coupled local- and regional-scale paleoecological records to reconstruct land use on an earthwork site in northeast Bolivia within the context of regional, climate-driven biome changes. This approach revealed evidence for an alternative scenario of Amazonian land use, which did not necessitate labor-intensive rainforest clearance for earthwork construction. Instead, we show that the inhabitants exploited a naturally open savanna landscape that they maintained around their settlement despite the climatically driven rainforest expansion that began ∼2,000 y ago across the region. Earthwork construction and agriculture on terra firme landscapes currently occupied by the seasonal rainforests of southern Amazonia may therefore not have necessitated large-scale deforestation using stone tools. This finding implies far less labor—and potentially lower population density—than previously supposed. Our findings demonstrate that current debates over the magnitude and nature of pre-Columbian Amazonian land use, and its impact on global biogeochemical cycling, are potentially flawed because they do not consider this land use in the context of climate-driven forest–savanna biome shifts through the mid-to-late Holocene