Performance enhancement of polymer nanocomposites via multiscale modelling of processing and properties

This paper provides an overview of research on modelling of the structure–property interactions of polymer nanocomposites in manufacturing processes (stretch blow moulding and thermoforming) involving large-strain biaxial stretching of relatively thin sheets, aimed at developing computer modelling tools to help producers of materials, product designers and manufacturers exploit these materials to the full, much more quickly than could be done by experimental methods alone. The exemplar systems studied are polypropylene and polyester terephalate, with nanoclays. These were compounded and extruded into 2mm thick sheet which was then biaxially stretched at 155°C for the PP and 90 to 100°C for the PET. Mechanical properties were determined for the unstretched and stretched materials, together with TEM and XRD studies of structure. Multi-scale modelling, using representative volume elements is used to model the properties of these products.

Distinguishing between direct and indirect effects of predators in complex ecosystems

1. Global declines in biodiversity have stimulated much research into the consequences of species loss for ecosystems and the goods and services they provide. Species at higher trophic levels are at greater risk of human-induced extinction yet remarkably little is known about the effects of consumer species loss across multiple trophic levels in natural complex ecosystems. Previous studies have been criticized for lacking experimental realism and appropriate temporal scale, running for short periods that are not sufficient to detect many of the mechanisms operating in the field.
2. We manipulated the presence of two predator species and two groups of their prey (primary consumers) and measured their independent and interactive effects on primary producers in a natural marine benthic system. The presence of predators and their prey was manipulated in the field for 14 months to distinguish clearly the direct and indirect effects of predators on primary producers and to identify mechanisms driving responses.
3. We found that the loss of either predator species had indirect negative effects on species diversity and total cover of primary producers. These cascading effects of predator species loss were mediated by the presence of intermediate consumers. Moreover, the presence of different intermediate consumers, irrespective of the presence or absence of their predators, determined primary producer assemblage structure. We identified direct negative effects of predators on their prey and several indirect effects of predators on primary producers but not all interactions could have been predicted based on trophic level.
4. Our findings demonstrate the importance of trophic cascade effects coupled with non-trophic interactions when predicting the effects of loss of predator species on primary producers and consequently for ecosystem functioning. There is a pressing need for improved understanding of the effects of loss of consumers, based on realistic scenarios of diversity loss, to test conceptual frameworks linking predator diversity to variation in ecosystem functioning and for the protection of biodiversity, ecosystem functioning and related services.

Development and validation of an ultrasensitive fluorescence planar waveguide biosensor for the detection of paralytic shellfish toxins in marine algae

Marine dinoflagellates of the genera Alexandrium are well known producers of the potent neurotoxic paralytic shellfish toxins that can enter the food web and ultimately present a serious risk to public health in addition to causing huge economic losses. Direct coastal monitoring of Alexandrium spp. can provide early warning of potential shellfish contamination and risks to consumers and so a rapid, sensitive, portable and easy-to-use assay has been developed for this purpose using an innovative planar waveguide device. The disposable planar waveguide is comprised of a transparent substrate onto which an array of toxin-protein conjugates is deposited, assembled in a cartridge allowing the introduction of sample, and detection reagents. The competitive assay format uses a high affinity antibody to paralytic shellfish toxins with a detection signal generated via a fluorescently labelled secondary antibody. The waveguide cartridge is analysed by a simple reader device and results are displayed on a laptop computer. Assay speed has been optimised to enable measurement within 15 min. A rapid, portable sample preparation technique was developed for Alexandrium spp. in seawater to ensure analysis was completed within a short period of time. The assay was validated and the LOD and CCß were determined as 12 pg/mL and 20 pg/mL respectively with an intra-assay CV of 11.3% at the CCß and an average recovery of 106%. The highly innovative assay was proven to accurately detect toxin presence in algae sampled from the US and European waters at an unprecedented cell density of 10 cells/L. © 2012 Elsevier B.V. All rights reserved.

Censoring the 1970s: The BBFC and the Decade that Taste Forgot

This book is a study of the British Board of Film Censors in the 1970s. In permitting and refusing specific material to be shown on cinema screens the BBFC were dictating patterns of taste and helping shape and determine notions of acceptability. Contentious and controversial texts like A Clockwork Orange (1971), Straw Dogs (1971) The Devils (1971) and Life of Brian (1979) have been used to draw attention to the way in which the BBFC operated in the 1970s. While it is true to say that these films encountered major censorship problems, what of the hundreds of other films which were being classified at the same time? Did all films struggle with the British censors in this period, and can these famous examples be fitted into broader patterns of censorship policy and practice?

In studying over 250 film files from the BBFC archive, this work reveals how 1970s films such as Vampire Circus (1971), Confessions of a Window Cleaner (1974) and Carry on Emmannuelle (1978) also ran in to trouble with the film censor. This work explores the complex process of negotiation and compromise which affected all film submissions in the 1970s and the way in which the BBFC actively, and often sympathetically, negotiated with film directors, producers and distributors to assign the correct category to each film. The lack of any defined formal censorship policy in this period allowed the BBFC to work alongside the film industry and push cultural, social and artistic boundaries; however it also left the Board open to accusations of favouritism, subjectivity and personal bias.

This work is not simply a study of controversial films and contentious issues, but rather engages with wider issues of changing permission, legal struggles, the influence of the media and the legislative and governmental controls which both helped and hindered the BBFC in this important post-war decade. The approach used within this work focuses on historical and archival research, making it importantly inter-textual and offering a great deal to scholars from a number of associated disciplines, including history, social policy, media and communications and politics.

Photosynthetic pigments in soils from northern Victoria Land (continental Antarctica) as proxies for soil algal community structure and function

Although soil algae are among the main primary producers in most terrestrial ecosystems of continental Antarctica, there are very few quantitative studies on their relative proportion in the main algal groups and on how their distribution is affected by biotic and abiotic factors. Such knowledge is essential for understanding the functioning of Antarctic terrestrial ecosystems. We therefore analyzed biological soil crusts from northern Victoria Land to determine their pH, electrical conductivity (EC) water content (W), total and organic C (TC and TOC) and total N (TN) contents, and the presence and abundance of photosynthetic pigments. In particular, the latter were tested as proxies for biomass and coarse-resolution community structure. Soil samples were collected from five sites with known soil algal communities and the distribution of pigments was shown to reflect differences in the relative proportions of Chlorophyta, Cyanophyta and Bacillariophyta in these sites. Multivariate and univariate models strongly indicated that almost all soil variables (EC, W, TOC and TN) were important environmental correlates of pigment distribution. However, a significant amount of variation is independent of these soil variables and may be ascribed to local variability such as changes in microclimate at varying spatial and temporal scales. There are at least five possible sources of local variation: pigment preservation, temporal variations in water availability, temporal and spatial interactions among environmental and biological components, the local-scale patchiness of organism distribution, and biotic interactions. (C) 2009 Elsevier Ltd. All rights reserved.

Novel hydrolysis-probe based qPCR assay to detect saxitoxin transcripts of dinoflagellates in environmental samples

Paralytic Shellfish Poisoning (PSP) is a serious human illness caused by ingestion of seafood enriched with paralytic shellfish toxins (PSTs). PSTs are neurotoxic compounds produced by marine dinoflagellates, specifically by Alexandrium spp., Gymnodinium catenatum and Pyrodinium bahamense. Every year, massive monitoring of PSTs and their producers is undertaken worldwide to avoid PSP incidences. Here we developed a sensitive, hydrolysis probe-based quantitative PCR (qPCR) assay to detect a gene essential for PST synthesis across different dinoflagellate species and genera and tested it on cDNA generated from environmental samples spiked with Alexandrium minutum or Alexandrium fundyense cells. The assay was then applied to two environmental sample series from Norway and Spain and the results were complemented with cell counts, LSU-based microarray data and toxin measurements (enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) biosensor method). The overall agreement between the results of the qPCR assay and the complementary data was good. The assay reliably detected sxtA transcripts from Alexandrium spp. and G. catenatum, even though Alexandrium spp. cell concentrations were mostly so low that they could not be quantified microscopically. Agreement between the novel assay and toxin measurements or cell counts was generally good; the few inconsistencies observed were most likely due to disparate residence times of sxtA transcripts and PSTs in seawater, or, in the case of cell counts, to dissimilar sxtA4 transcript numbers per cell in different dinoflagellate strains or species. © 2013 Elsevier B.V.

Life Cycle Assessment guidelines for the sustainable production and recycling of aggregates:The Sustainable Aggregates Resource Management project (SARMa)

The mining/quarrying industry is a sector of industry where there are very few Life Cycle Assessment (LCA) tools, and where the role of LCA has been poorly investigated. A key issue is the integration of three inter-dependent life cycles: Project, Asset and Product. Given the unique features of mining LCAs, this Note from the Field presents a common methodology implemented within the Sustainable Aggregates Resource Management (SARMa) Project (www.sarmaproject.eu) in order to boost adoption of LCA in the aggregate industry in South Eastern Europe. The proposed methodology emphasises the importance of resource efficiency and recycling in the context of a Sustainable Supply Mix of aggregates for the construction industry. Through its adoption, aggregate producers, recyclers, and governmental planners would gain confidence with LCA tools and conduct consistent and meaningful life cycle analyses of natural and recycled aggregates. © 2011 Elsevier Ltd. All rights reserved.

Identification of vegetable oil botanical speciation in refined vegetable oil blends using an innovative combination of chromatographic and spectroscopic techniques

European Regulation 1169/2011 requires producers of foods that contain refined vegetable oils to label the oil types. A novel rapid and staged methodology has been developed for the first time to identify common oil species in oil blends. The qualitative method consists of a combination of a Fourier Transform Infrared (FTIR) spectroscopy to profile the oils and fatty acid chromatographic analysis to confirm the composition of the oils when required. Calibration models and specific classification criteria were developed and all data were fused into a simple decision-making system. The single lab validation of the method demonstrated the very good performance (96% correct classification, 100% specificity, 4% false positive rate). Only a small fraction of the samples needed to be confirmed with the majority of oils identified rapidly using only the spectroscopic procedure. The results demonstrate the huge potential of the methodology for a wide range of oil authenticity work.

Varieties of resource nationalism in sub-Saharan Africa’s energy and minerals markets

This article examines resource nationalism in sub-Saharan Africa's energy and minerals markets. It does so by exploring economic and political developments in three cases: Nigeria as an example of a petro-state established by means of expropriation in the wake of decolonisation; South Africa, a mature mining industry shaped by its settler colonial history; and Mozambique, a new and therefore highly-dependent entrant into the league of significant natural gas producers. Extractive industries have played a controversial role in sub-Saharan Africa due in particular to the prevalence of the resource curse. Nevertheless, energy exports will continue to play an important role in fuelling economic growth and, potentially, also development as new deposits of natural gas and oil are discovered across the region. Resource nationalism has, moreover, increasingly constrained operations of the traditionally dominant Western energy companies, in particular as competition from state-owned energy companies in sub-Saharan Africa and from emerging powers such as China is increasing.

Characterisation of UK and Irish Cold-Pressed Rapeseed Oils in Relation to Quality Indices and Constituents.

Cold-pressed rapeseed oil (CPRSO) is produced when seeds from an oilseed rape crop are mechanically crushed whilst at a low temperature. CPRSO’s popularity is rapidly expanding and is now produced in most Northern European countries including both N.Ireland and ROI. The CPRSO industry is still relatively new and therefore not as widely researched as other high quality oils. Fifteen CPRSO from The UK, Ireland and France were examined to determine characteristic differences between the oils. Two samples of extra-virgin olive oil and two samples of refined rapeseed oil were also included in the investigation to assess performance against market competitors. The antioxidant potential of the oils was assessed using the ABTS and DPPH radical scavenging assays. Both unexpectedly showed that refined rapeseed oil had the highest potential whilst there was significant difference between many of the CPRSO’s. The acid value (ACOS method Cd 3d-63) ranged widely from 0.47-3.41. To predict the stability during storage, an accelerated oxidation test was carried out where the oils were placed in an oven (60°C) and peroxide value was monitored. The results showed extra-virgin olive oil underwent the least oxidation during the trial. The refined rapeseed oil suffered the worst levels of oxidation whilst the CPRSO’s performed similarly but with some variation. Fatty acid composition was investigated with GC-MS and some of the major fatty acids were found to differ significantly between producers. Minor compound analysis was achieved with extraction and identification through HPLC. All results are critically discussed and compared to relevant published studies.

STARTEC: Novel processing technologies in the development of a decision support tool to ensure safe and nutritious Ready-To-Eat foods

Ready-to-eat (RTE) foods can be readily consumed with minimum or without any further preparation; their processing is complex—involving thorough decontamination processes— due to their composition of mixed ingredients. Compared with conventional preservation technologies, novel processing technologies can enhance the safety and quality of these complex products by reducing the risk of pathogens and/ or by preserving related health-promoting compounds. These novel technologies can be divided into two categories: thermal and non-thermal. As a non-thermal treatment, High Pressure Processing is a very promising novel methodology that can be used even in the already packaged RTE foods. A new “volumetric” microwave heating technology is an interesting cooking and decontamination method directly applied to foods. Cold Plasma technology is a potential substitute of chlorine washing in fresh vegetable decontamination. Ohmic heating is a heating method applicable to viscous products but also to meat products. Producers of RTE foods have to deal with challenging decisions starting from the ingredients suppliers to the distribution chain. They have to take into account not only the cost factor but also the benefits and food products’ safety and quality. Novel processing technologies can be a valuable yet large investment for several SME food manufacturers, but they need support data to be able to make adequate decisions. Within the FP7 Cooperation funded by the European Commission, the STARTEC project aims to develop an IT decision supporting tool to help food business operators in their risk assessment and future decision making when producing RTE foods with or without novel preservation technologies.

Docking the value of pigmeat? Prevalence and financial implications of welfare lesions in Irish slaughter pigs.

Expansion of the meat inspection process to incorporate animal-based welfare measurements could contribute towards significant improvements in pig (Sus scrofa domesticus) welfare and farm profitability. This study aimed to determine the prevalence of different welfare-related lesions on the carcase and their relationship with carcase condemnations (CC) and carcase weight (CW). The financial implications of losses associated with CC and CW reductions related to the welfare lesions were also estimated. Data on tail lesions, loin bruising and bursitis, CW and condemnation/trimming outcome (and associated weights) were collected for 3,537slaughter pigs (mean [± SEM] carcase weight: 79.2 [± 8.82] kg). Overall, 72.5% of pigs had detectable tail lesions, whilst 16.0 and 44.0% were affected by severe loin bruising and hind limb bursitis, respectively. There were 2.5% of study carcases condemned and a further 3.3% were trimmed. The primary cause of CC was abscessation. While tail lesion severity did not increase the risk of abscessation, it was significantly associated with CC. Male pigs had a higher risk of tail lesions and of CC. The financial loss to producers associated with CC and trimmings was estimated at €1.10 per study pig. CW was reduced by up to 12 kg in cases of severe tail lesions. However, even mild lesions were associated with a significant reduction in CW of 1.2 kg. The value of the loss in potential CW associated with tail lesions was €0.59 per study pig. Combined with losses attributable to CC and trimmings this represented a loss of 43% of the profit margin per pig, at the time of the study, attributable to tail biting. These findings illustrate the magnitude of the impact of tail biting on pig welfare and on profitability of the pig industry. They also emphasise the potential contribution that the inclusion of welfare parameters at meat inspection could make to pig producers in informing herd health and welfare management plans.

A survey of location inference techniques on Twitter

The increasing popularity of the social networking service, Twitter, has made it more involved in day-to-day communications, strengthening social relationships and information dissemination. Conversations on Twitter are now being explored as indicators within early warning systems to alert of imminent natural disasters such earthquakes and aid prompt emergency responses to crime. Producers are privileged to have limitless access to market perception from consumer comments on social media and microblogs. Targeted advertising can be made more effective based on user profile information such as demography, interests and location. While these applications have proven beneficial, the ability to effectively infer the location of Twitter users has even more immense value. However, accurately identifying where a message originated from or author’s location remains a challenge thus essentially driving research in that regard. In this paper, we survey a range of techniques applied to infer the location of Twitter users from inception to state-of-the-art. We find significant improvements over time in the granularity levels and better accuracy with results driven by refinements to algorithms and inclusion of more spatial features.

14C as a tool to trace terrestrial carbon in a complex lake system: implications for foodweb structure and carbon cycling

Carbon and nitrogen stable isotope analysis (SIA) has identified the terrestrial subsidy of freshwater food-webs but relies on different 13C fractionation in aquatic and terrestrial primary producers. However dissolved inorganic carbon (DIC) is partly comprised of 13C depleted respiration of terrestrial C and ‘old’ C derived from weathering of catchment geology. SIA thus fails to differentiate between the contribution of old and recently fixed terrestrial C. DIC in alkaline lakes is partially derived from weathering of 14C-free carbonaceous bedrock This
yields an artificial age offset leading samples to appear significantly older than their actual age. As such, 14C can be used as a biomarker to identify the proportion of autochthonous C in the food-web. With terrestrial C inputs likely to increase, the origin and utilisation of ‘old’ or ‘recent’ allochthonous C in the food-web can also be determined. Stable isotopes and 14C were measured for biota, particulate organic matter (POM), DIC and dissolved organic carbon (DOC) from Lough Erne, Northern Ireland, a humic but alkaline lake. High winter δ15N values in calanoid zooplankton (δ15N =24‰) relative to phytoplankton and POM (δ15N =6‰ and 12‰ respectively) may reflect several microbial trophic levels between terrestrial C and calanoids. Furthermore winter calanoid 14C ages are consistent with DOC from inflowing rivers (87 and 75 years BP respectively) but not phytoplankton (355 years BP). Summer calanoid δ13N, δ15N and 14C (312 years BP) indicate greater reliance on phytoplankton. There is also temporal and spatial variation in DIC, DOC and POM C isotopes.

14C as a tool to trace terrestrial carbon in a complex lake system: implications for food-web structure and carbon cycling

Globally lakes bury and remineralise significant quantities of terrestrial C, and the associated flux of terrestrial C strongly influences their functioning. Changing deposition chemistry, land use and climate induced impacts on hydrology will affect soil biogeochemistry and terrestrial C export¹ and hence lake ecology with potential feedbacks for regional and global C cycling. C and nitrogen stable isotope analysis (SIA) has identified the terrestrial subsidy of freshwater food webs. The approach relies on different ¹³C fractionation in aquatic and terrestrial primary producers, but also that inorganic C demands of aquatic primary producers are partly met by ¹³C depleted C from respiration of terrestrial C, and ‘old’ C derived from weathering of catchment geology. SIA thus fails to differentiate between the contributions of old and recently fixed terrestrial C. Natural abundance ¹⁴C can be used as an additional biomarker to untangle riverine food webs² where aquatic and terrestrial δ ¹³C overlap, but may also be valuable for examining the age and origin of C in the lake. Primary production in lakes is based on dissolved inorganic C (DIC). DIC in alkaline lakes is partially derived from weathering of carbonaceous bedrock, a proportion of which is¹⁴C-free. The low ¹⁴C activity yields an artificial age offset leading samples to appear hundreds to thousands of years older than their actual age. As such, ¹⁴C can be used to identify the proportion of autochthonous C in the food-web. With terrestrial C inputs likely to increase, the origin and utilisation of ‘fossil’ or ‘recent’ allochthonous C in the food-web can also be determined. Stable isotopes and 14C were measured for biota, particulate organic matter (POM), DIC and dissolved organic carbon (DOC) from Lough Erne, Northern Ireland, a humic alkaline lake. Temporal and spatial variation was evident in DIC, DOC and POM C isotopes with implications for the fluctuation in terrestrial export processes. Ramped pyrolysis of lake surface sediment indicates the burial of two C components. ¹⁴C activity (507 ± 30 BP) of sediment combusted at 400˚C was consistent with algal values and younger than bulk sediment values (1097 ± 30 BP). The sample was subsequently combusted at 850˚C, yielding 14C values (1471 ± 30 BP) older than the bulk sediment age, suggesting that fossil terrestrial carbon is also buried in the sediment. Stable isotopes in the food web indicate that terrestrial organic C is also utilised by lake organisms. High winter δ ¹⁵N values in calanoid zooplankton (δ ¹⁵N = 24%¸) relative to phytoplankton and POM (δ ¹⁵N = 6h and 12h respectively) may reflect several microbial trophic levels between terrestrial C and calanoids. Furthermore winter calanoid 14C ages are consistent with DOC from an inflowing river (75 ± 24 BP), not phytoplankton (367 ± 70 BP). Summer calanoid δ ^13C, δ ¹⁵N and ¹⁴C (345 ± 80 BP) indicate greater reliance on phytoplankton.

¹ Monteith, D.T et al., (2007) Dissolved organic carbon trends resulting from changes in atmospheric deposition chemistry. Nature, 450:537-535

² Caraco, N., et al.,(2010) Millennial-aged organic carbon subsidies to a modern river food web. Ecology,91: 2385-2393.