In defence of a multi-paradigmatic approach to theory development in community psychology

It was once said, "There is nothing more practical than a good theory" (Lewin, 1952, p. 169) and yet Community Psychology (CP) as a practical discipline is beset with a theory-practice gulf that does not appear to be narrowing. The article by Jason, Stevens, Ram, Miller, Beasley, and Gleason (2016) plays a commendable role in outlining the challenges faced by community-based researchers and practitioners in developing, testing and utilizing theoretical approaches that could reliably benefit the health and well-being of target groups in a community. Quite rightly, Jason et al. (2016) have acknowledged that theories used in the field of CP should more accurately be termed as frameworks, rather than constituting actual theories, since theories would be expected to offer a comprehensive methodology for explaining and predicting behaviors in a range of settings. And herein lies the problem… Should the CP discipline be aimed at transposing findings, and theories, developed from research conducted in one type of social environment to a host of other potentially similar social settings? Researchers and practitioners alike may experience tensions in attempting to replicate an intervention, based on a theory, with other samples and settings. There are recent worrying trends from one study to show that with "the current (selective) publication system [in academic journals], replications may increase bias in effect size estimates" (Nuijten, et al., 2015, p.172). Likewise, we find there is a tendency in academia to avoid publishing non-significant findings (Franco, Malhotra, & Simonvits, 2014), even though a more honest and transparent approach to theory development and testing in CP would be through registration of hypotheses before a study has commenced, just as Jason et al. (2016) have endorsed. This would certainly be a way forward, but until funding agencies and academic journals are unified in their insistence for all a priori hypotheses to be communicated prior to conducting a study, this may be only one way to build theories that are trustworthy in the field of CP

Seasonal variation in utilization of biogenic microhabitats by littorinid snails on tropical rocky shores

Mobile species may actively seek refuge from stressful conditions in biogenic habitats on rocky shores. In Hong Kong, the upper intertidal zone is extremely stressful, especially in summer when organisms are emersed for long periods in hot desiccating conditions. As a result, many species migrate downshore between winter and summer to reduce these stressful conditions. The littorinids Echinolittorina malaccana and E. vidua, for example, are found on open rock surfaces high on the shore in winter but the majority migrate downshore in summer to the same tidal height as a common barnacle, Tetraclita japonica. In the laboratory, where environmental conditions could be controlled to approximate those occurring on the shore, we tested whether the downshore migration allowed littorinids to select barnacles as biogenic habitats to reduce stress and if this behaviour varied between seasons. In summer, littorinids demonstrated a strong active preference for the barnacles, which was not observed in the cool winter conditions, when animals were found on open rock surfaces even when barnacles were present. Littorinids, therefore, only actively select biogenic habitats during the summer in Hong Kong when they migrate downshore, suggesting that such habitats may play an important, temporal, role in mitigating environmental stress on tropical shores. © 2012 The Author(s).published_or_final_versio

Latent Class Analysis and Latent Profile Analysis

Latent class analysis (LCA) and latent profile analysis (LPA) are powerful techniques that enable researchers to glean insights into “hidden” psychological experiences to create typologies and profiles to provide better-informed community-based policies and practice. These analytic methods have been used in a variety of domains, such as: psychosis symptomatology in the general population (Kibowski & Williams, 2012; Murphy, Shevlin, & Adamson, 2007; Shevlin, Murphy, Dorahy, & Adamson, 2007); substance abuse (Cleveland, Collins, Lanza, Greenberg, & Feinberg, 2010; James, McField, & Montgomery, 2013), peer victimization (Nylund, Bellmore, Nishina, & Graham, 2007), and anti-social/self-defeating behavior (Rosato & Baer, 2010). LCA and LPA are versatile methods of dealing with data of interest to community-based researchers in a deep and psychologically grounded way. This chapter will address the nuances of how and when to use LCA and LPA. Case studies of LCA and LPA will also be presented to illustrate the applicability of these techniques

Feeding preferences of the herbivorous crab Grapsus albolineatus: The differential influence of algal nutrient content and morphology

The tropical rocky shore crab Grapsus albolineatus selectively consumes rare filamentous algae over more abundant foliose algae during the winter in Hong Kong. Laboratory experiments have shown that growth of G. albolineatus is enhanced and mortality reduced when given a diet of filamentous algae as opposed to foliose algae. In the laboratory, G. albolineatus consumed filamentous algae (Enteromorpha clathrata, Hincksia mitchelliae and Chaetomorpha antennina) in greater amounts than any foliose algae (Dermonema frappieri, Pterocladia tenuis, Porphyra suborbiculata, Ulva fasciata, Endarachne binghamiae) in both multiple choice and no choice experiments. The most energy-rich alga was Pterocladia, while Porphyra had the highest protein content. Filamentous algae had lower overall nutrient contents than foliose algae. Consumption rates for Enteromorpha and Hincksia were, however, sufficiently higher than for Porphyra, which ensured that the net intake of nutrients per day was greater. Even though protein assimilation efficiency was higher for Porphyra than Hincksia, G. albolineatus assimilated more protein, per day, from Hincksia. When the confounding effects of morphology and nutrient value were separated, by offering the crab choices of commercially available algae (Laminaria sp.) cut into different forms (foliose and filamentous), G. albolineatus showed a strong preference for the filamentous form, despite both forms having the same nutrient value Preference for filamentous forms is likely to be constrained by the morphology of the chelae, which have delicate tips, and appear unable to tear foliose algae Algal morphology, therefore, appears to be of prime importance and the nutrient content and digestibility of algae of secondary importance in determining the feeding preferences of G. albolineatus. The high consumption rate of filamentous algae outweighs their relative nutrient deficiencies, indicating that they are better suited to meeting the physiological needs of the crab than foliose algae.published_or_final_versio

Penis-rejection in a mangrove littorinid snail: why do females reject males?

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Knowing when to stop: Rhythms of locomotor activity in the high-shore limpet, Cellana grata Gould

The high shore limpet, Cellana grata, forages whilst awash, moving upshore with the rising tide and retreating downshore on the ebbing tide to become inactive in refuges. Spraying inactive, emersed individuals with seawater at low tide invokes a locomotory response, with limpets moving up the shore. Controlled laboratory experiments under continuous white or red light (to simulate light or dark periods respectively) and continuous emersion, immersion or seawater spray showed that C. grata possesses a free-running endogenous rhythm of locomotor activity. This rhythm was maintained over 30. days in continuous seawater spray and white light. Maximum entropy spectral analysis (MESA) revealed two major components to this rhythm, at 7.2. h and 12.4. h. The 12.4. h component is of a circatidal nature and appears to initiate activity, allowing individuals to anticipate immersion by the incoming tide, although this clock can be over-ridden by strong wave splash or spraying vigorously with seawater. The 7.2. h period, however, was the most significant component and is suggested to act as a stopwatch enabling the limpet to assess the duration of each foraging excursion in order to prevent being stranded at the wrong height on the shore. The environmental stimulus for both components of the endogenous rhythm in C. grata appears to be the time of first exposure to wave wash from the incoming tide. C. grata, therefore, has behavioural rhythms entrained to initiate and also terminate activity, which play a role in the limpet maintaining a fixed vertical level on the shore when inactive. © 2010 Elsevier B.V.postprin

Early development of algal assemblages under different regimes of physical and biotic factors on a seasonal tropical rocky shore

The roles of physical factors and herbivory in structuring the early development of algal assemblages were investigated on a seasonal, tropical rocky shore in Hong Kong. Physical stress was manipulated by irrigating areas with filtered seawater, whilst herbivore access was controlled using fences. Algal colonisation was monitored at 2 tidal heights (high- and lowshore), once in the cool and dry season and once in the hot and wet season. Dry areas were only colonised in the lowshore and, even when herbivores were excluded, dry highshore areas never developed a macroalgal cover. Algal assemblages did however, develop in highshore irrigated areas where, in the presence of herbivores, encrusting algae (e.g. Hapalospongidion gelatinosum and coralline crusts) developed. In areas excluding herbivores, ephemeral erect algae (e.g. Ulva spp.) developed. All lowshore treatments developed algal assemblages. In the hot season, after an initial phase of erect algae, encrusting algae developed where herbivores had access, whereas, in the cool season, erect Corallina spp. dominated these treatments. In herbivore exclusions, erect ephemeral algae developed in the hot season with a sparse cover of encrusting algae (Ralfsia expansa and coralline crusts) whilst, in the cool season, a cover of Corallina spp. and erect ephemeral algae became abundant. When irrigation was terminated, erect algal cover decreased dramatically in each season in the highshore, although encrusting algae persisted at reduced cover. In lowshore areas, algal cover decreased marginally when irrigation was terminated and only during the hot season. The timing (i.e. hot or cool season) of liberation of rock space was, therefore. important for the development of algal assemblages. In lowshore areas, assemblages dominated by encrusting algae typical of rocky shores in Hong Kong developed only in the presence of herbivores and only during the hot season. During the cool season, Corallina spp. became dominant, while exclusion of herbivores (during either season) resulted in the development of ephemeral, erect algal assemblages.published_or_final_versio

Primary succession on a seasonal tropical rocky shore: The relative roles of spatial heterogeneity and herbivory

Hong Kong is within the tropics and has a seasonal climate. In winter, shores support patches of ephemeral macroalgae and areas of seemingly bare rock close to crevices where molluscan herbivores are abundant. Using a factorial design of herbivore exclusions in areas far and close to crevices, the development of algal assemblages was monitored in mid-shore, cleared areas, in winter. To estimate the role of herbivore mucus deposition, half the treatments received a mucus application. Algal development was estimated from macroalgal and biofilm development and chlorophyll a levels. In all areas, biofilms (diatoms, unicellular cyanobacteria) developed rapidly in herbivore exclusions followed by ephemeral macroalgae (Enteromorpha spp. and Porphyra suborbiculata). In herbivore access treatments, however, the algal assemblage was influenced by treatment location; few macroalgae developed in areas close to crevices, and the rock was dominated by cyanobacteria. A negative relationship between macroalgae and biofilms suggested that ephemeral algae were competitively dominant. In areas distant from herbivore refuges, ephemeral macroalgae did develop, illustrating that the effectiveness of molluscan herbivores was limited to 50 to 100 cm from these refuges. The absence of large herbivorous fish, and the sparse numbers of herbivorous crabs at this site, means that algae can achieve a spatial escape from consumption, and where this occurs competition between producers is important in assemblage development. Mucus appeared to play a limited role, only sometimes stimulating initial stages of unicellular cyanobacteria and macroalgae. With the onset of summer, macroalgae died back, and rock space became available for colonization. Unicellular cyanobacteria developed rapidly but were replaced in all treatments by the encrusting macroalga, Hapalospongidion gelatinosum, which dominated treatments until the end of the experiment. On seasonal, tropical shores processes influencing community structure can, therefore, be temporally variable and their relative importance, even at the same shore level, can change with season.published_or_final_versio

Primary succession on a seasonal tropical rocky shore: The relative roles of spatial heterogeneity and herbivory

Hong Kong is within the tropics and has a seasonal climate. In winter, shores support patches of ephemeral macroalgae and areas of seemingly bare rock close to crevices where molluscan herbivores are abundant. Using a factorial design of herbivore exclusions in areas far and close to crevices, the development of algal assemblages was monitored in mid-shore, cleared areas, in winter. To estimate the role of herbivore mucus deposition, half the treatments received a mucus application. Algal development was estimated from macroalgal and biofilm development and chlorophyll a levels. In all areas, biofilms (diatoms, unicellular cyanobacteria) developed rapidly in herbivore exclusions followed by ephemeral macroalgae (Enteromorpha spp. and Porphyra suborbiculata). In herbivore access treatments, however, the algal assemblage was influenced by treatment location; few macroalgae developed in areas close to crevices, and the rock was dominated by cyanobacteria. A negative relationship between macroalgae and biofilms suggested that ephemeral algae were competitively dominant. In areas distant from herbivore refuges, ephemeral macroalgae did develop, illustrating that the effectiveness of molluscan herbivores was limited to 50 to 100 cm from these refuges. The absence of large herbivorous fish, and the sparse numbers of herbivorous crabs at this site, means that algae can achieve a spatial escape from consumption, and where this occurs competition between producers is important in assemblage development. Mucus appeared to play a limited role, only sometimes stimulating initial stages of unicellular cyanobacteria and macroalgae. With the onset of summer, macroalgae died back, and rock space became available for colonization. Unicellular cyanobacteria developed rapidly but were replaced in all treatments by the encrusting macroalga, Hapalospongidion gelatinosum, which dominated treatments until the end of the experiment. On seasonal, tropical shores processes influencing community structure can, therefore, be temporally variable and their relative importance, even at the same shore level, can change with season.published_or_final_versio