Diversity and dynamics of protist communities in subtidal North Sea sediments in relation to metal pollution and algal bloom deposition

The Belgian Coastal Zone (BCZ) is heavily polluted by trace metals, that pose a potential threat to the marine ecosystem in the area, including to humans (a.o. via fisheries). Trace metals accumulate in silty, organically enriched sediments and changes in the environment can lead to the resuspension of the metals, with the activity of the benthic microbes as one potential factor influencing the release of TM into the water column. Benthic microbial activity and dynamics in turn are regulated by the availability of growth substrates, and sedimentation of phytoplankton blooms represents a major source of organic material for the benthic biota in subtidal areas. It remains unclear however, how microbial communities, phytodetritus deposition and TM behaviour interact in subtidal sediments. We aimed to obtain a better insight in the interactions between microbial communities, metal contaminants and algae-derived organic matter in contaminated sediments of the BCZ. Our study focussed on protist (unicellular eukaryotes) communities, which are largely understudied but ecologically very important since they occupy a central position in the benthic food webs, especially in the microbial loop. Both field studies and microcosm experiments were performed, and molecular fingerprinting techniques (18S rDNA and rRNA- based DGGE and clone libraries) were used to characterise protistan diversity and dynamics in the contaminated sediments. A high diversity was found, with members ecologically important as primary producers (mainly diatoms), grazers (Rhizaria, Alveolata, Amoebozoa, heterotrophic stramenopiles), saprobes (Fungi) or pathogen/parasites (e.g. Marine Alveolates Group I, Pirsonia sp.). Our results showed that phytoplankton deposition after the spring algal bloom stimulates microbial activity and activates the development of the microbial loop, and a positive link is suggested between this increased microbial activity and the observed increased mobilisation and upward metal fluxes. Moreover, we found indications that the diversity and structure of the protistan communities in these sediments are affected by the trace metals, as evidenced by both the field and experimental data

Multi-currency credit default swaps

Credit default swaps (CDS) on a reference entity may be traded in multiple currencies, in that, protection upon default may be offered either in the currency where the entity resides, or in a more liquid and global foreign currency. In this situation, currency fluctuations clearly introduce a source of risk on CDS spreads. For emerging markets, but in some cases even in well-developed markets, the risk of dramatic foreign exchange (FX)-rate devaluation in conjunction with default events is relevant. We address this issue by proposing and implementing a model that considers the risk of foreign currency devaluation that is synchronous with default of the reference entity. As a fundamental case, we consider the sovereign CDSs on Italy, quoted both in EUR and USD. Preliminary results indicate that perceived risks of devaluation can induce a significant basis across domestic and foreign CDS quotes. For the Republic of Italy, a USD CDS spread quote of 440 bps can translate into an EUR quote of 350bps in the middle of the Euro-debt crisis in the first week of May 2012. More recently, from June 2013, the basis spreads between the EUR quotes and the USD quotes are in the range around 40bps. We explain in detail the sources for such discrepancies. Our modeling approach is based on the reduced form framework for credit risk, where the default time is modeled in a Cox process setting with explicit diffusion dynamics for default intensity/hazard rate and exponential jump to default. For the FX part, we include an explicit default-driven jump in the FX dynamics. As our results show, such a mechanism provides a further and more effective way to model credit/FX dependency than the instantaneous correlation that can be imposed among the driving Brownian motions of default intensity and FX rates, as it is not possible to explain the observed basis spreads during the Euro-debt crisis by using the latter mechanism alone

Dinamiche di innovazione nelle politiche regionali di rigenerazione urbana: un’analisi multi-livello delle esperienze del Piemonte e della Puglia

La rigenerazione urbana, intesa quale processo rivolto non solo alla riqualificazione fisica (urbanistica ed edilizia), ma anche all’inclusione sociale e alla rinascita culturale di parti di città o regioni urbane, in alternativa all’espansione del territorio urbanizzato o a singoli interventi di riqualificazione fisica del patrimonio edilizio esistente, richiede una radicale innovazione delle politiche pubbliche e delle pratiche urbanistiche. I processi di innovazione, secondo la letteratura, si sviluppano seguendo cicli che alternano fasi di diffusione e consolidamento a fasi di stagnazione e arretramento. Questo contributo indaga su tali processi ponendo a confronto le esperienze regionali del Piemonte e della Puglia, ritenendole significative per lo sforzo di innovazione operato nel campo della rigenerazione urbana. A tal fine utilizza una versione modificata dell’approccio noto come “Multi-Level Perspective (MLP)” per analizzare le diverse sfere (cognitive, istituzionali, organizzative e operative) che incidono sulle dinamiche di innovazione e per cogliere i flussi multi-livello che legano le innovazioni sviluppate in un determinato contesto, da un lato, alle routine cognitive, regolative e operative che lo caratterizzano, dall’altro, alle più ampie dinamiche che influenzano le trasformazioni del contesto stesso. Ponendo a confronto le due politiche regionali di rigenerazione urbana si individuano i fattori che hanno favorito la diffusione e stabilizzazione di esperienze innovative, e quelli che ne hanno ostacolato lo sviluppo o portato alla stagnazione e al declino del loro carattere innovativo

Etching kinetics of nanodiamond seeds in the early stages of CVD diamond growth

We present an experimental study on the etching of detonation nanodiamond (DND) seeds during typical microwave chemical vapor deposition (MWCVD)conditions leading to ultra-thin diamond film formation, which is fundamental for many technological applications. The temporal evolution of the surface density of seeds on the Si(100) substrate has been assessed by scanning electron microscopy (SEM). The resulting kinetics have been explained in the framework of a model based on the effect of the particle size, according to the Young-Laplace equation,on both chemical potential of carbon atoms in DND and activation energy of the reaction with atomic hydrogen. The model describes the experimental kinetics of seeds' disappearance by assuming that nanodiamond particles with a size smaller than a "critical radius", r*, are etched away while those greater than r* can grow. Finally, the model allows to estimate the rate coefficients for growth and etching from the experimental kinetics

Size dependent etching of nanodiamond seeds in the early stages of CVD diamond growth

We present an experimental study on the etching of detonation nanodiamond (DND) seeds during typical microwave chemical vapor deposition (MWCVD) conditions leading to ultra-thin diamond film formation, which is fundamental for many technological applications. The temporal evolution of the surface density of seeds on Si(100) substrate has been assessed by scanning electron microscopy (SEM). The resulting kinetics have been explained in the framework of a model based on the effect of particle size, according to the Young-Laplace equation, on both chemical potential of carbon atoms in DND and activation energy of reaction. We found that seeds with size smaller than a critical radius, r*, are etched away while those greater than r* can grow. Finally, the model allows to estimate the rate coefficients for growth and etching from the experimental kinetics.Comment: 28 pages; 15 Figures, 3 Table

Linguistic and content validation of the translated and culturally adapted patient-generated subjective global assessment (PG-SGA)

The Patient-Generated Subjective Global Assessment (PG-SGA) is an instrument to screen, assess and monitor malnutrition and risk factors, and to triage for interventions. After having translated and culturally adapted the original PG-SGA for the Italian setting, according to International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Principles, we tested linguistic validity, i.e., perceived comprehensibility and difficulty, and content validity (relevance) of the Italian version of the PG-SGA in patients with cancer and a multidisciplinary sample of healthcare professionals (HCPs). Methods: After the translation and cultural adaptation of the original PG-SGA for the Italian setting, the patient component (i.e., PG-SGA Short Form (SF) was tested for linguistic validity (i.e., comprehensibility ad difficulty) in 120 Italian patients with cancer and 81 Italian HCPs. The full PG-SGA, i.e., patient and professional component of the PG-SGA, was tested for content validity, i.e., relevance, in 81 Italian HCPs. The data were collected by a questionnaire and evaluations were operationalized by a 4-point scale. Through item and scale indices we evaluated the comprehensibility (I–CI, S–CI), difficulty (I-DI, S-DI) and content validity (I-CVI, S-CVI). Scale indices 0.80–0.89 were considered acceptable, and scale indices ≥0.90 were considered excellent. Results: Patients perceived comprehensibility and difficulty of the PG-SGA SF (Boxes) as excellent (S–CI = 0.98, S-DI = 0.96). Professionals perceived comprehensibility of the professional component (Worksheets) as excellent (S–CI = 0.92), difficulty as acceptable (S-DI = 0.85), and content validity of the full PG-SGA as excellent (S-CVI = 0.92). Dietitians gave higher scores (indicating better scores) on comprehensibility, difficulty, and content validity of Worksheet 4 (physical exam) than the other professions. In Worksheet 4, four items were considered most difficult to complete and were considered below acceptable range. Relevance was perceived as excellent by professionals for both the patient component (S-CVI = 0.93) and the professional component (S-CVI = 0.90), resulting in S-CVI = 0.92 for the full PG-SGA. Slight textual modifications were implemented resulting in the final version of the Italian PG-SGA. Conclusions: Translation and cultural adaptation of the original PG-SGA resulted in the Italian version of the PG-SGA that maintained its original purpose and meaning and can be completed adequately and easily by patients and professionals. The Italian PG-SGA is considered relevant for screening, assessing and monitoring malnutrition and risk factors, as well as triaging for interventions by Italian HCPs.</p

are drug eluting stents superior to bare metal stents in patients with unprotected non bifurcational left main disease insights from a multicentre registry

Aims To compare long-term clinical outcome following drug-eluting stents (DES) or bare-metal stents (BMS) implantation on lesions located at the ostium or the shaft of the left main in a large real-world population. The advent of DES decreased the risk of unprotected left main coronary artery (ULMCA) restenosis when compared with BMS, but it is unclear if this advantage continues when non-bifurcational lesions are considered. Methods and results The GISE-SICI registry is a retrospective, observational multicentre registry promoted by the Italian Society of Invasive Cardiology in which 19 high-volume participating centres enrolled 1453 consecutive patients who underwent percutaneous coronary intervention on ULMCA between January 2002 and December 2006. From the registry, a total of 479 consecutive patients with ostial and shaft lesions who underwent DES ( n = 334) or BMS ( n = 145) implantation were analysed with extensive multivariable and propensity score adjustments. At 3-year follow-up, risk-adjusted survival rates were higher in patients treated with DES than in those treated with BMS. The adjusted hazard ratio (HR) for the risk of mortality after DES implantation relative to BMS implantation was 0.37 (95% CI: 0.15–0.96, P = 0.04). The adjusted HR for the risk of cardiac mortality was 0.31 (95% CI: 0.09–1.04, P = 0.06). The adjusted 3-year rates of target lesion revascularization (TLR) were not significantly lower in the DES group than in the BMS group ( P = 0.60). Conclusion In a large population of patients with lesions located at the ostium or the shaft of the left main in a real-world setting, DES were associated with favourable clinical outcomes when compared with BMS, although there was no evidence of a significant reduction in TLR with DES vs. BMS