About multi-resolution techniques for large eddy simulation of reactive multi-phase flows

A numerical technique for mesh refinement in the HeaRT (Heat Release and Transfer) numerical code is presented. In the CFD framework, Large Eddy Simulation (LES) approach is gaining in importance as a tool for simulating turbulent combustion pro- cesses, also if this approach has an high computational cost due to the complexity of the turbulent modeling and the high number of grid points necessary to obtain a good numerical solution. In particular, when a numerical simulation of a big domain is performed with a structured grid, the number of grid points can increase so much that the simulation becomes impossible: this problem can be overcomed with a mesh refinement technique. Mesh refinement technique developed for HeaRT numerical code (a staggered finite difference code) is based on an high order reconstruction of the variables at the grid interfaces by means of a least square quasi-eno interpolation: numerical code is written in modern Fortran (2003 standard of newer) and is parallelized using domain decomposition and message passing interface (MPI) standard

Observational evidence for a different IMF in the early Galaxy

The unexpected high incidence of carbon-enhanced, s-process enriched unevolved stars amongst extremely metal-poor stars in the halo provides a significant constraint on the Initial Mass Function (IMF) in the early Galaxy. We argue that these objects are evidence for the past existence of a large population of intermediate-mass stars, and conclude that the IMF in the early Galaxy was different from the present, and shifted toward higher masses.Comment: 14 pages, 1 color figure, accepted for publication on Ap

Lie group analysis of a generalized Krichever-Novikov differential-difference equation

The symmetry algebra of the differential--difference equation $$\dot u_n = [P(u_n)u_{n+1}u_{n-1} + Q(u_n)(u_{n+1}+u_{n-1})+ R(u_n)]/(u_{n+1}-u_{n-1}),$$ where $P$, $Q$ and $R$ are arbitrary analytic functions is shown to have the dimension 1 \le \mbox{dim}L \le 5. When $P$, $Q$ and $R$ are specific second order polynomials in $u_n$ (depending on 6 constants) this is the integrable discretization of the Krichever--Novikov equation. We find 3 cases when the arbitrary functions are not polynomials and the symmetry algebra satisfies \mbox{dim}L=2. These cases are shown not to be integrable. The symmetry algebras are used to reduce the equations to purely difference ones. The symmetry group is also used to impose periodicity $u_{n+N}=u_n$ and thus to reduce the differential--difference equation to a system of $N$ coupled ordinary three points difference equations

CAD in mammography: lesion-level versus case-level analysis of the effects of prompts on human decisions

Object: To understand decision processes in CAD-supported breast screening by analysing how prompts affect readers’ judgements of individual mammographic features (lesions). To this end we analysed hitherto unexamined details of reports completed by mammogram readers in an earlier evaluation of a CAD tool. Material and methods: Assessments of lesions were extracted from 5,839 reports for 59 cancer cases. Statistical analyses of these data focused on what features readers considered when recalling a cancer case and how readers reacted to CAD prompts. Results: About 13.5% of recall decisions were found to be caused by responses to features other than those indicating actual cancer. Effects of CAD: lesions were more likely to be examined if prompted; the presence of a prompt on a cancer increased the probability of both detection and recall especially for less accurate readers in subtler cases; lack of prompts made cancer features less likely to be detected; false prompts made non-cancer features more likely to be classified as cancer. Conclusion: The apparent lack of impact reported for CAD in some studies is plausibly due to CAD systematically affecting readers’ identification of individual features, in a beneficial way for certain combinations of readers and features and a damaging way for others. Mammogram readers do not ignore prompts. Methodologically, assessing CAD by numbers of recalled cancer cases may be misleading

Aspectos ecológicos de la ficoflora de ambientes acuáticos del Chaco Oriental (Argentina)

The present study describes the al gal flora of some streams and tropical swamps ("esteros") settled in the Eastern Chaco between the Pilcomayo (25°15'S; 57°45'W) and Amores (28°15'S; 59°30'W) rivera towards the Paraguay-Paraná axis. Samples taken during 1984 at different hydrometric levels within the annual hydrologic re gime, were compared. The quali and quantitative study of the phytoplankton was carried out, as well as the periphytic flora from natural substrates with addition of SEM analyses. Counts of phytoplankton were done by the Utermohl method. Phytoplankton density was low during the high water period (between 15 and 280 ind.ml-1), and high species richness were found. During the low water period the phytoplankton density ranged from 20 to 1746 ind.ml-1. The highest density was recorded in highly salinitized water bodies with blooms of halophilous species (Glenodinium balticum and Protoperidinium achromaticum).  In response to high salinity and alkalinity diatoms such as Nitzschia acicularis var. closterioides, Surirella striatula, Campylodiscus clypeus and Bacillaria paradoxa were found in the phytoplankton. Besides, Audouinella sp. (Rhodophyta) and Enteromorpha sp. (Chlorophyta) were observed in the periphyton. In the tropical swamps the phytoplankton density ranged from 22 to 525 ind.ml-1 with high species number of Euglenophyta. Acidity indicators species (within Chrysophyceae, Xanthophyceae and Diatomophyceae) were recorded in the periphyton. Thus, local populations showed strong differences with respect to other regional waterbodies of the Northeastem of Argentina.The present study describes the al gal flora of some streams and tropical swamps ("esteros") settled in the Eastern Chaco between the Pilcomayo (25°15'S; 57°45'W) and Amores (28°15'S; 59°30'W) rivera towards the Paraguay-Paraná axis. Samples taken during 1984 at different hydrometric levels within the annual hydrologic re gime, were compared. The quali and quantitative study of the phytoplankton was carried out, as well as the periphytic flora from natural substrates with addition of SEM analyses. Counts of phytoplankton were done by the Utermohl method. Phytoplankton density was low during the high water period (between 15 and 280 ind.ml-1), and high species richness were found. During the low water period the phytoplankton density ranged from 20 to 1746 ind.ml-1. The highest density was recorded in highly salinitized water bodies with blooms of halophilous species (Glenodinium balticum and Protoperidinium achromaticum).  In response to high salinity and alkalinity diatoms such as Nitzschia acicularis var. closterioides, Surirella striatula, Campylodiscus clypeus and Bacillaria paradoxa were found in the phytoplankton. Besides, Audouinella sp. (Rhodophyta) and Enteromorpha sp. (Chlorophyta) were observed in the periphyton. In the tropical swamps the phytoplankton density ranged from 22 to 525 ind.ml-1 with high species number of Euglenophyta. Acidity indicators species (within Chrysophyceae, Xanthophyceae and Diatomophyceae) were recorded in the periphyton. Thus, local populations showed strong differences with respect to other regional waterbodies of the Northeastem of Argentina

Longitudinal effect of eteplirsen versus historical control on ambulation in Duchenne muscular dystrophy

To continue evaluation of the long-term efficacy and safety of eteplirsen, a phosphorodiamidate morpholino oligomer designed to skip DMD exon 51 in patients with Duchenne muscular dystrophy (DMD). Three-year progression of eteplirsen-treated patients was compared to matched historical controls (HC). METHODS: Ambulatory DMD patients who were 657 years old and amenable to exon 51 skipping were randomized to eteplirsen (30/50mg/kg) or placebo for 24 weeks. Thereafter, all received eteplirsen on an open-label basis. The primary functional assessment in this study was the 6-Minute Walk Test (6MWT). Respiratory muscle function was assessed by pulmonary function testing (PFT). Longitudinal natural history data were used for comparative analysis of 6MWT performance at baseline and months 12, 24, and 36. Patients were matched to the eteplirsen group based on age, corticosteroid use, and genotype. RESULTS: At 36 months, eteplirsen-treated patients (n = 12) demonstrated a statistically significant advantage of 151m (p < 0.01) on 6MWT and experienced a lower incidence of loss of ambulation in comparison to matched HC (n = 13) amenable to exon 51 skipping. PFT results remained relatively stable in eteplirsen-treated patients. Eteplirsen was well tolerated. Analysis of HC confirmed the previously observed change in disease trajectory at age 7 years, and more severe progression was observed in patients with mutations amenable to exon skipping than in those not amenable. The subset of patients amenable to exon 51 skipping showed a more severe disease course than those amenable to any exon skipping. INTERPRETATION: Over 3 years of follow-up, eteplirsen-treated patients showed a slower rate of decline in ambulation assessed by 6MWT compared to untreated matched HC. Ann Neurol 2016;79:257-271

Public perceptions of hazards associated with Brazil nuts (Bertholletia excelsa) : evaluation of risk within an European context

One of the most important economic plants of the Amazon is the Brazil nut (Bertholletia excelsa). Brazil nuts for international trade are mainly obtained from wild collection rather than from plantations, often cited as one of the most important products of extractive reserves in Amazonia. The European Commission (2003/493/EC) has imposed strict regulations on the import from Brazil of Brazil nuts in their shells, as the shells have been found to contain high levels of aflatoxins, which can lead to liver cancer. This may have a negative impact on the Brazilian exports of shelled Brazil nuts, due to possible public awareness. The aim of the present research is to assess public perceptions regarding Brazil nuts and to contrast these with other nuts in general through the use of the Portuguese version of the Perceived Food Risk Index (PFRI). A sample of 418 consumers was drawn through a door-to-door interview using a random route walk procedure and following a quota sampling controlled for sex, age and location. Consumers were asked to choose the most relevant quality and preservation characteristics and to identify their consumption patterns for Brazil nuts and for nuts in general. Risk perception was evaluated over ten risk characteristics, for each of the following hazards: i) aflatoxins; ii) biological contaminants; iii) organoleptic changes; iv) fragments and strange bodies and v) microbial contamination. Additionally, subjects were asked to rate the probability of each hazard occurring in Brazil nuts or in nuts in general. Results show high consumptions of nuts in general, and a reduced consumption of Brazil nuts, although with low differences on the dimensions of risk perception. Concluding, this work adds to knowledge about the perceptions of risk connected to Brazil nuts consumption, namely that consumers perceive Brazil nuts as safe as nuts in general

Universality of the off-equilibrium response function in the kinetic Ising chain

The off-equilibrium response function $\chi (t,t_w)$ and autocorrelation function $C(t,t_w)$ of an Ising chain with spin-exchange dynamics are studied numerically and compared with the same quantities in the case of spin-flip dynamics. It is found that, even though these quantities are separately different in the two cases, the parametric plot of $\chi (t,t_w)$ versus $C(t,t_w)$ is the same. While this result could be expected in higher dimensionality, where $\chi (C)$ is related to the equilibrium state, it is far from trivial in the one dimensional case where this relation does not hold. The origin of the universality of $\chi(C)$ is traced back to the optimization of domains position with respect to the perturbing external field. This mechanism is investigated resorting to models with a single domain moving in a random environment.Comment: 24 pages, 7 figure

Tools for the high penetration of PV Systems in the EU electrical networks: results of PVCROPS Project

The Solar Energy Industrial Initiative established the objective of integrating PV into the grid to provide up to 12% of the EU electricity demand. The FP7 project PVCROPS has developed solutions to allow the high penetration of PV systems in EU electrical networks and to reduce its Levelized Cost (LCoE) increasing PV system performance. The solutions consist of documents like technical specifications and toolboxes for design, prediction, integration of batteries and automatic detection of performance failures. Six of them are on-line free tools and thirteen are marketable products. These tools allow reducing the LCoE up to 30%, increasing the Performance Ratio up to 9% and PV penetration of 30%. The tools developed by PVCROPS are detailed in www.pvcrops.e

Radiative Decays of Excited Vector Mesons

Radiative decays of the $1^3S_1$ radial and $1^3D_1$ orbital excitations of the $\rho$, $\omega$ and $\phi$ are calculated in the quark model, using wave functions obtained variationally from the Hamiltonian with standard quark-model parameters. The larger radiative widths should be measurable at new high-intensity facilities being proposed, and in some cases may be measurable in data from existing experiments. The radiative decays are a strong discriminator between the $1^3S_1$ and $1^3D_1$ excitations, and can also be used to provide unique information about the decay products.Comment: 23 pages, 6 figure