Droplet Initiated Rupture of High Viscosity Jets to Create Uniform Emulsions

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Creating highly monodisperse emulsions of high viscosity fluids has long been a challenging task. Even with the advent of micro-engineered emulsification systems such as membranes and microchannels obtaining a good degree of uniformity is hampered as these systems are very prone to jetting. We present a method of increasing the range at which uniform droplets can be produced by the use of droplet initiated jet rupture. In this method, a third, low viscosity inner phase, is introduced in the dispersed phase forcing the dispersed phase to form a shell around each drop and effectively reverts the system from jetting to dripping. Formulations are chosen so that the resulting core-shell droplets are unstable and soon rupture to form highly monodisperse emulsions. The rate of internal droplet production is found to be the governing parameter in the system and must be below a critical frequency. This frequency is found to be well predicted by Plateau–Rayleigh instability theory of jet rupture, where the perturbations caused by internal drops are at a wavelength larger than the circumference of the would-be jet. This method is easy to implement in conventional microfluidic designs and equipment and greatly facilitates the ability to produce very uniform emulsions of high viscosity

From Single to Core-Shell Drops in Non-Confined Microfluidics

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.For many encapsulation applications such as nutrients, cells and drugs, large core-shell drops are required. Conventional confined microfluidic devices are limited to a rather small sized (< 1mm) droplets because of difficulties associated with phase separation at low flow rates. We report a microfluidic device which can produce such large range of drop sizes (~200 Am- 6 mm) with varying shell thickness (~1 Am- 1 mm) under the maximum influence of buoyancy, which has so far remained unexplored. The existing physical model for single drop formation is extended for the core-shell drop. The facile nature of working with such systems means scale up would be easy

Language attitudes and use in a transplanted setting: Greek Cypriots in London

In this paper we explore language attitudes and use in the Greek Cypriot community in London, England. Our study is based on an earlier survey carried out in Nicosia, Cyprus and we compare attitudes to language and reported language use in the two communities. We thereby highlight the significance of sociolinguistic variables on similar groups of speakers. We further extend our investigation to include codeswitching practices in the London community. \ud Analysis of language attitudes and use within the Greek-Cypriot population of London, and comparisons with findings in Nicosia, reflect symbolic forces operating in the two contexts. Despite obvious differences between the two communities, (most obviously the official languages and distinct cultural backgrounds of the two nations), the Greek Cypriot Dialect continues to play an active role in both. English is however the ‘default choice‘ for young Cypriots in the UK and Standard Modern Greek occupies a much more limited role than in Cyprus. It is argued that differences in language attitudes and use can be interpreted in light of different market forces operating in the nation (i.e. Cyprus) and the Diaspora (i.e. UK)

Modeling the evolution of a classic genetic switch

Abstract Background The regulatory network underlying the yeast galactose-use pathway has emerged as a model system for the study of regulatory network evolution. Evidence has recently been provided for adaptive evolution in this network following a whole genome duplication event. An ancestral gene encoding a bi-functional galactokinase and co-inducer protein molecule has become subfunctionalized as paralogous genes (GAL1 and GAL3) in Saccharomyces cerevisiae, with most fitness gains being attributable to changes in cis- regulatory elements. However, the quantitative functional implications of the evolutionary changes in this regulatory network remain unexplored. Results We develop a modeling framework to examine the evolution of the GAL regulatory network. This enables us to translate molecular changes in the regulatory network to changes in quantitative network function. We computationally reconstruct an inferred ancestral version of the network and trace the evolutionary paths in the lineage leading to S. cerevisiae. We explore the evolutionary landscape of possible regulatory networks and find that the operation of intermediate networks leading to S. cerevisiae differs substantially depending on the order in which evolutionary changes accumulate; in particular, we systematically explore evolutionary paths and find that some network features cannot be optimized simultaneously. Conclusions We find that a computational modeling approach can be used to analyze the evolution of a well-studied regulatory network. Our results are consistent with several experimental studies of the evolutionary of the GAL regulatory network, including increased fitness in Saccharomyces due to duplication and adaptive regulatory divergence. The conceptual and computational tools that we have developed may be applicable in further studies of regulatory network evolution

Large-Scale Spatio-Temporal Patterns of Mediterranean Cephalopod Diversity

Species diversity is widely recognized as an important trait of ecosystems’ functioning and resilience. Understanding the causes of diversity patterns and their interaction with the environmental conditions is essential in order to effectively assess and preserve existing diversity. While diversity patterns of most recurrent groups such as fish are commonly studied, other important taxa such as cephalopods have received less attention. In this work we present spatio-temporal trends of cephalopod diversity across the entire Mediterranean Sea during the last 19 years, analysing data from the annual bottom trawl survey MEDITS conducted by 5 different Mediterranean countries using standardized gears and sampling protocols. The influence of local and regional environmental variability in different Mediterranean regions is analysed applying generalized additive models, using species richness and the Shannon Wiener index as diversity descriptors. While the western basin showed a high diversity, our analyses do not support a steady eastward decrease of diversity as proposed in some previous studies. Instead, high Shannon diversity was also found in the Adriatic and Aegean Seas, and high species richness in the eastern Ionian Sea. Overall diversity did not show any consistent trend over the last two decades. Except in the Adriatic Sea, diversity showed a hump-shaped trend with depth in all regions, being highest between 200–400 m depth. Our results indicate that high Chlorophyll a concentrations and warmer temperatures seem to enhance species diversity, and the influence of these parameters is stronger for richness than for Shannon diversityVersión del editor4,411

Non-indigenous species refined national baseline inventories: A synthesis in the context of the European Union's Marine Strategy Framework Directive

Refined baseline inventories of non-indigenous species (NIS) are set per European Union Member State (MS), in the context of the Marine Strategy Framework Directive (MSFD). The inventories are based on the initial assessment of the MSFD (2012) and the updated data of the European Alien Species Information Network, in collaboration with NIS experts appointed by the MSs. The analysis revealed that a large number of NIS was not reported from the initial assessments. Moreover, several NIS initially listed are currently considered as native in Europe or were proven to be historical misreportings. The refined baseline inventories constitute a milestone for the MSFD Descriptor 2 implementation, providing an improved basis for reporting new NIS introductions, facilitating the MSFD D2 assessment. In addition, the inventories can help MSs in the establishment of monitoring systems of targeted NIS, and foster cooperation on monitoring of NIS across or within shared marine subregions.Henn Ojaveer and Maiju Lehtiniemi wish to acknowledge the project COMPLETE (Completing management options in the Baltic Sea region to reduce risk of invasive species introduction by shipping), co-financed by the European Union's funding Programme Interreg Baltic Sea Region (European Regional Development Fund). João Canning-Clode was supported by a starting grant in the framework of the 2014 FCT Investigator Programme (IF/01606/2014/CP1230/CT0001) and wish to acknowledge the support of Fundação para a Ciência e Tecnologia (FCT), through the strategic project UID/MAR/04292/2019 granted to MARE

Non-indigenous species refined national baseline inventories : A synthesis in the context of the European Union's Marine Strategy Framework Directive

Refined baseline inventories of non-indigenous species (NIS) are set per European Union Member State (MS), in the context of the Marine Strategy Framework Directive (MSFD). The inventories are based on the initial assessment of the MSFD (2012) and the updated data of the European Alien Species Information Network, in collaboration with NIS experts appointed by the MSs. The analysis revealed that a large number of NIS was not reported from the initial assessments. Moreover, several NIS initially listed are currently considered as native in Europe or were proven to be historical misreportings. The refined baseline inventories constitute a milestone for the MSFD Descriptor 2 implementation, providing an improved basis for reporting new NIS introductions, facilitating the MSFD D2 assessment. In addition, the inventories can help MSs in the establishment of monitoring systems of targeted NIS, and foster cooperation on monitoring of NIS across or within shared marine subregions. Highlights • Refined MSFD baseline inventories of non-indigenous species (NIS) are set in EU. • The inventories are given per EU Member State (MS) and MSFD subregion up to 2012. • The NIS lists provide a basis for reporting new NIS introductions in EU after 2012. • Our work constitutes a milestone for the MSFD Descriptor 2 implementation