Interactions between poly(ethylene glycol) and protein in dichloromethane/water emulsions: A study of interfacial properties

From adsorption kinetics and interfacial rheological studies performed by using a pendant-drop method, i.e. in conditions close to those of the primary emulsion of the water-in-oil-in-water emulsion-encapsulation technique, it was shown that adsorption of the hen egg-white lysozyme (HEWL) at the water/dichloromethane (DCM) interface can be efficiently slowed down by modulating some parameters. It was shown that a decrease of the ionic strength of the aqueous phase, and the optimization of the density of the poly(ethylene glycol) (PEG) adsorbed film by increasing the PEG concentration or by modulating the polymer chain length, can significantly decrease the rate of adsorption of HEWL at the water/DCM interface. Moreover, it was shown that the choice of the dissolution phase of PEG (DCM or water) clearly influences the results

Interactions between poly(ethylene glycol) and protein in dichloromethane/water emulsions. 2. Conditions required to obtain spontaneous emulsification allowing the formation of bioresorbable poly(D,L lactic acid) microparticles

From microscopic observations, it was established that an oil-in-water emulsion with droplets of a size in the micrometer range can spontaneously form at room temperature without additional external stirring as soon as a solvent that is only partly miscible to water-like dichloromethane (DCM) is put in contact with an aqueous mixture of polyethylene glycol (PEG) and a protein. Experimental results show that emulsification only occurs if the system simultaneously includes PEG with middle chain, an organic solvent partly miscible to water and for which PEG affinity is sufficiently high, and a protein. From adsorption kinetics, it appears that this spontaneous emulsification process is related to the rapid diffusion of DCM towards water through the formation of interfacial turbulences, once the accumulation of PEG close to the DCM/water interface occurs. The oil droplets formed would be then stabilized by adsorbed protein molecules. Since the presence of polylactic acid in the organic phase did not prevent the emulsion formation, we studied the feasibility of formulating microparticles using this polymer. From results, it appears that microcapsules with a polymeric shell, with a homogeneous size of about 50 microm and able to encapsulate a model hydrophobic drug, such as amiodarone, can be obtained by using this spontaneous emulsification method

A multi-model approach to evaluate the role of environmental variability and fishing pressure in sardine fisheries

Understanding the fluctuations in population abundance is a central question in fisheries. Sardine fisheries is of great importance to Portugal and is data-rich and of primary concern to fisheries managers. In Portugal, sub-stocks of Sardina pilchardus (sardine) are found in different regions: the Northwest (IXaCN), Southwest (IXaCS) and the South coast (IXaS-Algarve). Each of these sardine sub-stocks is affected differently by a unique set of climate and ocean conditions, mainly during larval development and recruitment, which will consequently affect sardine fisheries in the short term. Taking this hypothesis into consideration we examined the effects of hydrographic (river discharge), sea surface temperature, wind driven phenomena, upwelling, climatic (North Atlantic Oscillation) and fisheries variables (fishing effort) on S. pilchardus catch rates (landings per unit effort, LPUE, as a proxy for sardine biomass). A 20-year time series (1989-2009) was used, for the different subdivisions of the Portuguese coast (sardine sub-stocks). For the purpose of this analysis a multi-model approach was used, applying different time series models for data fitting (Dynamic Factor Analysis, Generalised Least Squares), forecasting (Autoregressive Integrated Moving Average), as well as Surplus Production stock assessment models. The different models were evaluated, compared and the most important variables explaining changes in LPUE were identified. The type of relationship between catch rates of sardine and environmental variables varied across regional scales due to region-specific recruitment responses. Seasonality plays an important role in sardine variability within the three study regions. In IXaCN autumn (season with minimum spawning activity, larvae and egg concentrations) SST, northerly wind and wind magnitude were negatively related with LPUE. In IXaCS none of the explanatory variables tested was clearly related with LPUE. In IXaS-Algarve (South Portugal) both spring (period when large abundances of larvae are found) northerly wind and wind magnitude were negatively related with LPUE, revealing that environmental effects match with the regional peak in spawning time. Overall, results suggest that management of small, short-lived pelagic species, such as sardine quotas/sustainable yields, should be adapted to a regional scale because of regional environmental variability

Collateral Optimization : Liquidity & Funding Value Adjustments, - Best Practices -

The purpose of this paper is to understand how the current financial landscape shaped by the crises and new regulations impacts Investment Banking’s business model. We will focus on quantitative implications, i.e. valuation, modeling and pricing issues, as well as qualitative implications, i.e. best practices to manage quantitative aspects and handle these functions to the current Investment Banking organization. We considered two pillars to shape our vision of collateral optimization: 1. Collateral as a refinancing instrument. Collateral is shifting from a mere hedging instrument for counterparty risk to a strategic refinancing instrument. 2. Improve asymmetric collateral quality and profitability. Recent requirements on collateralization highly impact collateral management through the increase in haircuts and funding of good-quality collateral. As a result, more and more banks are considering their net collateral balance as a KPI, i.e. monitoring their net collateral balance position and identifying the need in cash funding or transforming. We built our approach on three key standards: • In most cases, banks should prioritize the reception of cash and delivery of securities, what we call “Asymmetric Collateral Management”. - This implies banks have to capitalize on their valuation functions to boost profitability of the net collateral balance and take advantage of pricing conditions (e.g. for CSA Discounting, precise valuation and pricing of LVA/FVA). • Regarding Management of Non-Cash Collateral, banks should focus on - Optimization of the cash-circuit to manage the various levers of Non-Cash Collateral Transformation into Cash (repo market, central bank loans, re-hypothecation of received non-cash collateral as collateral for other deals). - Management of the collateral quality (both received and delivered), to source and receive high quality collateral and deliver lower quality collateral (Cheapest-To-Deliver Collateral Management). • Considering Management of Liquidity Issues, banks should carefully consider Collateral Management in case of liquidity issues (e.g. sale in case of default, use of re-hypothecation). Being unable to deliver good quality collateral can be seen as a negative sign for the counterparty’s financial health. We will further study the Collateral Offer Services of top financial institutions, providing specific expertise and a tailor-made approach to the new challenges of Collateral Management

Environmental and Socio-Economical Impacts of the Peruvian Anchoveta Supply Chains: Work Plan and First Results

The Peruvian anchoveta fishery (the largest mono-specific fleet worldwide) supplies mostly a chain of fishmeal and fish oil aimed at producing animal feeds, mostly in other continents, whereas others supply chains for direct human consumption only use <1% of the anchoveta landing. Although improving during the last 10 years, this situation is surprising in a country where part of the human population suffers from malnutrition when not starvation (having also in mind that anchoveta products are rich in proteins and with high content in omega 3). Furthermore, the viability of the fishmeal and fish oil supply chain is questionable due to its high impact on the environment and its low employment rate. Its energy consumption (and related fossil fuel use, green house effect production, etc.) is high all along the supply chain: extraction, transformation, inter-continental transport of fish products and animal protein outputs, etc. A research program, lead by IMARPE and IRD, was launched in 2009 and will quantify the environmental and socio-economical impacts of the Peruvian anchoveta supply chains for direct and indirect human consumption, from end to end. The first step will be a comparison of impacts resulting from the extraction phase according to the type of boat (small-scale, semi-industrial or industrial) and, within each of these three categories, to boat size (ranging from 2 to 600 t of holding capacity, with large overlapping between boat types. Partial results on this first step will be presented, in particular a life cycle analyses, employment and economical rent.Keywords: Contributions of Fisheries to Socioeconomic Wellbeing, Fish and Aquaculture Sectors Development, Fisheries Economic

The small pelagic fishery of the Pemba Channel, Tanzania: what we know and what we need to know for management under climate change

Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance