Predicting signatures of anisotropic resonance energy transfer in dye-functionalized nanoparticles

Resonance energy transfer (RET) is an inherently anisotropic process. Even the simplest, well-known F\"orster theory, based on the transition dipole-dipole coupling, implicitly incorporates the anisotropic character of RET. In this theoretical work, we study possible signatures of the fundamental anisotropic character of RET in hybrid nanomaterials composed of a semiconductor nanoparticle (NP) decorated with molecular dyes. In particular, by means of a realistic kinetic model, we show that the analysis of the dye photoluminescence difference for orthogonal input polarizations reveals the anisotropic character of the dye-NP RET which arises from the intrinsic anisotropy of the NP lattice. In a prototypical core/shell wurtzite CdSe/ZnS NP functionalized with cyanine dyes (Cy3B), this difference is predicted to be as large as 75\% and it is strongly dependent in amplitude and sign on the dye-NP distance. We account for all the possible RET processes within the system, together with competing decay pathways in the separate segments. In addition, we show that the anisotropic signature of RET is persistent up to a large number of dyes per NP.Comment: 9 pages, 5 figures. Supplementary information available at http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra22433d/unauth#!divAbstrac

Framework for Supporting Genomic Operations

Next Generation Sequencing (NGS) is a family of technologies for reading the DNA or RNA, capable of producing whole genome sequences at an impressive speed, and causing a revolution of both biological research and medical practice. In this exciting scenario, while a huge number of specialized bio-informatics programs extract information from sequences, there is an increasing need for a new generation of systems and frameworks capable of integrating such information, providing holistic answers to the needs of biologists and clinicians. To respond to this need, we developed GMQL, a new query language for genomic data management that operates on heterogeneous genomic datasets. In this paper, we focus on three domain-specific operations of GMQL used for the efficient processing of operations on genomic regions, and we describe their efficient implementation; the paper develops a theory of binning strategies as a generic approach to parallel execution of genomic operations, and then describes how binning is embedded into two efficient implementations of the operations using Flink and Spark, two emerging frameworks for data management on the cloud

Single culture and co-culture of two Synechococcus phylotypes respond differently to nanoflagellate grazing

Cyanobacteria belonging to the genus Synechococcus are found in lake waters typically as planktonic single cells and monospecific microcolonies. In oligotrophic lakes, single cells dominate in spring, while microcolonies are mostly found in late summer-autumn when the large colonial cyanobacteria increase in number. Since grazing activity is known as one of the major factors inducing microbial phenotypical changes, the formation of Synechococcus microcolonies was proposed as an efficient defence strategy against sizeselective predators. To better understand this ecological interaction, we explored the effect of grazing by the mixotrophic nanoflagellate Poteriochromonas sp. on the aggregation of two freshwater Synechococcus strains belonging to different phylogenetic clades (phycoerythrin-rich cells, PE, Group A; phycocyanin-rich cells, PC, Group I). During four days of incubation, we followed the dynamics of single-cells, microcolonies, and flagellates in semicontinuous cultures under different treatments (single culture and co-culture, with and without predators) by flow cytometry, epifluorescence microscopy and PhytoPAM. In single culture with the addition of Poteriochromonas, we observed the formation of grazing-induced monoclonal PE microcolonies, conversely limited in PC. In co-culture, there was an interaction between PE and PC, with an active microcolony formation by both PE and PC, and an increase of PC photosynthetic fitness (Fv/Fm). In co-culture, the microenvironment, generated by the formation of PE microcolonies, PC cells, bacteria and Poteriochromonas, can be the site of a beneficial "communication signalling" among Synechococcus cells for attaining the best spatial distribution for the fitness of the group

The use of polymorphic state modifiers in solid lipid microparticles: The role of structural modifications on drug release performance

This study investigates the correlation between the structural and release properties of solid lipid microparticles (MPs) of tristearin containing 5 % w/w of four different liquid additives used as crystal modifiers: isopropyl myristate (IM), ethyl oleate (EO), oleic acid (OA) and medium chain triglycerides (MCT). All additives accelerated the conversion of the unstable α-form of tristearin, formed after the MPs manufacturing, to the stable β-polymorph and the transformation was completed within 24 h (for IM and EO) or 48 h (for OA and MCT). The kinetic of polymorphic transition at 25 ◦C was investigated by simultaneous synchrotron SAXS/WAXS and DSC analysis after melting and subsequent cooling of the lipid mixture. After crystallization in the α-phase, additives accelerate the solid-solid phase transformation to β-tristearin. SAXS data showed that two types of structural modifications occurred on MPs during storage: compaction of the crystal packing (slight decrease in lamellar thickness) and crystal growth (increased number of stacked lipid lamellae). The release behavior of a model hydrophilic drug (caffeine) at two different amounts (15 % and 30 %) from MPs was studied in water and biorelevant media simulated the gastric and intestinal environment. It was particularly significant that the introduction of IM, EO and MCT were able to prolong the drug release in water, passing from a diffusion-based Higuchi kinetics to a perfect zero-order kinetic. Moreover, the overall release profiles were higher in biorelevant media, where erosion/digestion of MPs was observed. After 6 months, a moderate but statistically significant change in release profile was observed for the MPs with IM and EO, which can be correlated with the timedependent structural alterations (i.e. larger average crystallite size) of these formulations; while MPs with OA or MCT displayed stable release profiles. These findings help to understand the correlation between release behavior, polymorphism and supramolecular-level structural modification of lipid formulations containing crystal modifiers

Digitization in the Market for Entrepreneurial Finance: Innovative Business Models and New Financing Channels

Digitization creates new financial channels that complement traditional intermediaries, but may raise concerns over fraud, cybersecurity, or bubbles. Artificial intelligence and machine learning change the way in which traditional investors work. This special issue focuses on economic, cultural, and regulatory determinants of fintech development, and on the new forms of information production and processing engendered by digital entrepreneurial finance. We provide a general overview of digitization in the market for entrepreneurial finance, illustrate how the different articles in the special issue contribute to advance our knowledge, and identify promising avenues for research

LZER0: A Cost-Effective Multi-Purpose GNSS Platform

Recent advances in Global Navigation Satellite System (GNSS) technology have made low-cost sensors available to the mass market, opening up new opportunities for real-time ground deformation and structure monitoring. In this paper, we present a new product developed in this framework by the National Institute of Oceanography and Applied Geophysics–OGS in collaboration with a private company (SoluTOP SAS): a cost-effective, multi-purpose GNSS platform called LZER0, suitable not only for surveying measurements, but also for monitoring tasks. The LZER0 platform is a complete system that includes the GNSS equipment (M8T single-frequency model produced by u-blox) and the web portal where the results are displayed. The GNSS data are processed using the RTKLIB software package, and the processed results are made available to the end user. The relative positioning mode was adopted both with real-time and post-processing RTKLIB engines. We present three applications of LZER0—cadastral, monitoring, and automotive—which demonstrate that it is a flexible, multi-purpose platform that is easy to use in terms of both hardware and software, and can be easily deployed to perform various tasks in the research, educational, or professional sectors

Plant scientists' research attention is skewed towards colourful, conspicuous and broadly distributed flowers

Despite the perception that plant science focuses on strictly scientific criteria, this analysis finds that there is an aesthetic bias in regards to which plants, based on certain traits, receive more research attention. Scientists' research interests are often skewed toward charismatic organisms, but quantifying research biases is challenging. By combining bibliometric data with trait-based approaches and using a well-studied alpine flora as a case study, we demonstrate that morphological and colour traits, as well as range size, have significantly more impact on species choice for wild flowering plants than traits related to ecology and rarity. These biases should be taken into account to inform more objective plant conservation efforts.Peer reviewe