University of Plymouth

About: University of Plymouth is a education organization based out in Plymouth, Plymouth, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 7301 authors who have published 20396 publications receiving 679758 citations.

Impacts of discarded plastic bags on marine assemblages and ecosystem functioning.

Abstract: The accumulation of plastic debris is a global environmental problem due to its durability, persistence, and abundance. Although effects of plastic debris on individual marine organisms, particularly mammals and birds, have been extensively documented (e.g., entanglement and choking), very little is known about effects on assemblages and consequences for ecosystem functioning. In Europe, around 40% of the plastic items produced are utilized as single-use packaging, which rapidly accumulate in waste management facilities and as litter in the environment. A range of biodegradable plastics have been developed with the aspiration of reducing the persistence of litter; however, their impacts on marine assemblages or ecosystem functioning have never been evaluated. A field experiment was conducted to assess the impact of conventional and biodegradable plastic carrier bags as litter on benthic macro- and meio-faunal assemblages and biogeochemical processes (primary productivity, redox condition, organic matter content, and pore-water nutrients) on an intertidal shore near Dublin, Ireland. After 9 weeks, the presence of either type of bag created anoxic conditions within the sediment along with reduced primary productivity and organic matter and significantly lower abundances of infaunal invertebrates. This indicates that both conventional and biodegradable bags can rapidly alter marine assemblages and the ecosystem services they provide.

Child Speech Recognition in Human-Robot Interaction: Evaluations and Recommendations

Abstract: An increasing number of human-robot interaction (HRI) studies are now taking place in applied settings with children. These interactions often hinge on verbal interaction to effectively achieve their goals. Great advances have been made in adult speech recognition and it is often assumed that these advances will carry over to the HRI domain and to interactions with children. In this paper, we evaluate a number of automatic speech recognition (ASR) engines under a variety of conditions, inspired by real-world social HRI conditions. Using the data collected we demonstrate that there is still much work to be done in ASR for child speech, with interactions relying solely on this modality still out of reach. However, we also make recommendations for child-robot interaction design in order to maximise the capability that does currently exist.

Heating effects on water repellency in Australian eucalypt forest soils and their value in estimating wildfire soil temperatures

Abstract: Wildfires can induce or enhance soil water repellency under a range of vegetation communities. Accord- ing to mainly USA-based laboratory studies, repellency is eliminated at a maximum soil temperature (T )o f 280-400 ◦ C. Knowledge of T reached during a wildfire is important in evaluating post-fire soil physical prop- erties, fertility and seedbed status. T is, however, notoriously difficult to ascertain retrospectively and often based on indicative observations with a large potential error. Soils under fire-prone Australian eucalypt forests tend to be water repellent when dry or moderately moist even if long unburnt. This study aims to quantify the temperature of water repellency destruction for Australian topsoil material sampled under three sites with contrasting eucalypt cover (Eucalyptus sieberi, E. ovata and E. baxteri). Soil water repellency was present prior to heating in all sam- ples, increased during heating, but was abruptly eliminated at a specific T between 260 and 340 ◦ C. Elimination temperature varied somewhat between samples, but was found to be dependent on heating duration, with longest duration resulting in lowest elimination temperature. Results suggest that post-fire water repellency may be used as an aid in hindcasting soil temperature reached during the passage of a fire within repellency-prone environments.

Temperate and tropical algal-sea anemone symbioses

Abstract: In this review, we seek to develop new insights about the nature of algal-sea anemone symbioses by comparing such associations in temperate and tropical seas. Temperate seas un- dergo pronounced seasonal cycles in irradiance, temperature, and nutrients, while high irradi- ance, high temperature, and low nutrients are seasonally far less variable in tropical seas. We compare the nature of symbiosis between sea anemones ( = actinians) and zooxanthellae (Sym- biodinium spp.) in both regions to test tropical paradigms against temperate examples and to identify directions for future research. Although fewer anemone species are symbiotic in tem- perate regions, they are locally dominant and ecologically important members of the benthic community compared to the tropics. Zooxanthella densities tend to be lower in temperate anemones, but data are limited to a few species in both temperate and tropical seas. Zooxanthella densities are far more stable over time in temperate anemones than in tropical anemones, suggesting that temperate symbioses are more resistant to fluctuations in environmental parameters such as irradiance and temper- ature. Light-saturated photosynthetic rates of temperate and tropical zooxanthellae are similar, but temperate anemone hosts receive severely reduced carbon supplies from zooxanthellae during winter months when light is reduced. Symbiont transmission modes and specificity do not show any trends among anemones in tropical vs. temperate seas. Our review indicates the need for the following: (1) Investigations of other temperate and tropical symbiotic anemone species to assess the generality of trends seen in a few "model" anemones. (2) Attention to the field ecology of temperate and tropical algal-anemone symbioses, for example, how symbioses function under seasonally variable environmental factors and how zooxanthellae persist at high densities in darkness and winter. The greater stability of zooxan- thella populations in temperate hosts may be useful to understanding tropical symbioses in which bleaching (loss of zooxanthellae) is of major concern. (3) Study of the evolutionary history of symbiosis in both temperate and tropical seas. Continued exploration of the phylo- genetic relationships between host anemones and zooxanthella strains may show how and why zooxanthellae differ in anemone hosts in both environments.

Enclave space: a new metageography of development?

Abstract: Nothwithstanding crisis and critique, development remains an enduring frame within which much social and economic transformation is interpreted and envisaged. In the context of arguments about the need for a nuanced spatial vantage point on development, this paper asks what this means in the context of new conjunctures and constellations? It focuses on intensified processes and patterns of uneven development manifest as enclaves. The paper explores these drawing on literatures about Southeast Asia, sub-Saharan Africa and the Gulf.