Penicillium populations in dry-cured ham manufacturing plants.

Seven ham manufacturing plants were sampled for 1 year to assess the mycoflora present in the air and on hams, with special attention given to potential mycotoxin producers. Temperature and relative humidity were recorded in the ripening rooms. Maturing rooms held hams from 2 to 3 through 6 to 7 ripening months, and aging rooms held hams for the following 6 to 7 months, until the 14-month ripening point, when they were ready for the market. Mean temperatures and relative humidities registered during the study were 14.9 degrees C and 62.4%, respectively, in maturing rooms and 16.3 degrees C and 57.6% in aging rooms. Aspergilli and penicillia, potential mycotoxin producers, were isolated in all the plants from the air and the ham. Aspergilli represented 5% of the isolates, while penicillia were largely dominant, with Penicillium nalgiovense being the most represented species (around 60% of the penicillia), followed by Penicillium nordicum, with 10 and 26% of the penicillia isolated, respectively, from the air or the ham. Ochratoxin A production ability, checked in vitro at 250C, was observed in 50% of the P. nordicum isolates obtained both from the air and the ham. Air and ham surface contamination by penicillia was greater in the ripening rooms, where higher temperatures were registered. A certain correlation was also observed between air and ham surface contamination. On the basis of this study, P. nordicum, the ochratoxin A producer that is notable on proteinaceous substrates, is normally present in ham manufacturing plants in Italy, even though not a dominant species. Further studies are necessary to clarify and ensure if dry-curing conditions minimize the potential risk of ochratoxin A formation in the product

Influence of water activity and anti-fungal compounds on development and competitiveness of Fusarium verticillioides

This investigated the roles of water activity (aw) and fungicides on the competitiveness of two Fusarium verticillioides strains against other spoilage fungi commonly present in maize (F. proliferatum, Aspergillus niger, A. flavus, A. ochraceus and Penicillium verrucosum). Fungal strains were inoculated on artificial media containing maize flour. The effects were determined of three aw levels (0.99, 0.98 and 0.95) and three fungicides (tebuconazole, procloraz and prothioconazole) on fungal interactions, the Index of Dominance (ID) of isolates and fumonisin B1+B2 (FBs) production. The two strains of F. verticillioides showed similar behaviour in conditions where water was freely available (0.99 aw); at 0.98 and 0.95 aw both F. verticilliodes strains had the lowest total ID scores (8–6 and 10–12, respectively). They showed the same ability to compete against other fungi having the highest ID scores against P. verrucosum and A. ochraceus and the lowest against A. niger and A. flavus. The lowest water activity gave (0.95 aw) was the most conducive for fumonisin production with significant differences to 0.98 and 0.99 aw. In a co-inoculation experiment, only FBs production from P. verrucosum was greater in the presence of the F. verticilliodes strains other fungi. The use of fungicides reduced Indices of Dominancy (ID) for both F. verticilliodes strains. A significant reduction in F. verticilloides growth was observed when combining water stress and fungicide treatments. This information provides increased understanding of the colonisation patterns of F. verticillioides in relation to other mycobiota and to both environmental and chemical stresses, and has implications in relation to future climate change scenarios

Mapping the physico-chemical properties of mineral dust in western Africa: mineralogical composition

International audienceIn the last few years, several ground-based and air-borne field campaigns have allowed the exploration of theproperties and impacts of mineral dust in western Africa,one of the major emission and transport areas worldwide.In this paper, we explore the synthesis of these observationsto provide a large-scale quantitative view of the mineralogi-cal composition and its variability according to source regionand time after transport.This work reveals that mineral dust in western Africa is amixture of clays, quartz, iron and titanium oxides, represent-ing at least 92 % of the dust mass. Calcite ranged between0.3 and 8.4 % of the dust mass, depending on the origin. Ourdata do not show a systematic dependence of the dust min-eralogical composition on origin; this is to be the case as, inmost of the instances, the data represent the composition ofthe atmospheric burden after 1–2 days after emission, whenair masses mix and give rise to a more uniform dust load.This has implications for the representation of the mineraldust composition in regional and global circulation modelsand in satellite retrievals.Iron oxides account for 58±7 % of the mass of elementalFe and for between 2 and 5 % of the dust mass. Most of themare composed of goethite, representing between 52 and 78 %of the iron oxide mass. We estimate that titanium oxides ac-count for 1–2 % of the dust mass, depending on whether thedust is of Saharan or Sahelian origin.The mineralogical composition is a critical parameter forestimating the radiative and biogeochemical impact of min-eral dust. The results regarding dust composition have been used to estimate the optical properties as well as the iron frac-tional solubility of Saharan and Sahelian dust.Data presented in this paper are provided in numeri-cal form upon email request while they are being turnedinto a public database, the Dust-Mapped Archived Proper-ties (DUST-MAP), which is an open repository for compo-sitional data from other source regions in Africa and world-wide

Comparing Alzheimer’s and Parkinson’s diseases networks using graph communities structure

Background: Recent advances in large datasets analysis offer new insights to modern biology allowing system-level investigation of pathologies. Here we describe a novel computational method that exploits the ever-growing amount of "omics" data to shed light on Alzheimer's and Parkinson's diseases. Neurological disorders exhibit a huge number of molecular alterations due to a complex interplay between genetic and environmental factors. Classical reductionist approaches are focused on a few elements, providing a narrow overview of the etiopathogenic complexity of multifactorial diseases. On the other hand, high-throughput technologies allow the evaluation of many components of biological systems and their behaviors. Analysis of Parkinson's Disease (PD) and Alzheimer's Disease (AD) from a network perspective can highlight proteins or pathways common but differently represented that can be discriminating between the two pathological conditions, thus highlight similarities and differences. Results: In this work we propose a strategy that exploits network community structure identified with a state-of-the-art network community discovery algorithm called InfoMap, which takes advantage of information theory principles. We used two similarity measurements to quantify functional and topological similarities between the two pathologies. We built a Similarity Matrix to highlight similar communities and we analyzed statistically significant GO terms found in clustered areas of the matrix and in network communities. Our strategy allowed us to identify common known and unknown processes including DNA repair, RNA metabolism and glucose metabolism not detected with simple GO enrichment analysis. In particular, we were able to capture the connection between mitochondrial dysfunction and metabolism (glucose and glutamate/glutamine). Conclusions: This approach allows the identification of communities present in both pathologies which highlight common biological processes. Conversely, the identification of communities without any counterpart can be used to investigate processes that are characteristic of only one of the two pathologies. In general, the same strategy can be applied to compare any pair of biological networks

Aerosols attenuating the solar radiation collected by solar tower plants: the horizontal pathway at surface level [Póster]

Póster elaborado para el Solar Paces 2015 celebrado del 12 al 16 de octubre de 2015 en Cape Town (Sudáfrica

On the Parity Problem in One-Dimensional Cellular Automata

We consider the parity problem in one-dimensional, binary, circular cellular automata: if the initial configuration contains an odd number of 1s, the lattice should converge to all 1s; otherwise, it should converge to all 0s. It is easy to see that the problem is ill-defined for even-sized lattices (which, by definition, would never be able to converge to 1). We then consider only odd lattices. We are interested in determining the minimal neighbourhood that allows the problem to be solvable for any initial configuration. On the one hand, we show that radius 2 is not sufficient, proving that there exists no radius 2 rule that can possibly solve the parity problem from arbitrary initial configurations. On the other hand, we design a radius 4 rule that converges correctly for any initial configuration and we formally prove its correctness. Whether or not there exists a radius 3 rule that solves the parity problem remains an open problem.Comment: In Proceedings AUTOMATA&JAC 2012, arXiv:1208.249

Solar energy attenuated in a Solar Thermal Energy plant, due to aerosol extinction between the heliostats and the optical receiver

Presentación realizada en: 15th EMS Annual Meeting and 12th European Conference on Applications of Meteorology (ECAM) celebrado del 7 al 11 de septiembre de 2015 en Sofía, Bulgaria

Smoke and clouds above the Southeast Atlantic: upcoming field campaigns probe absorbing aerosol’s impact on climate

ArticleFrom July through October, smoke from biomass burning fires on the southern African sub-continent are transported westward through the free troposphere over one of the largest stratocumulus cloud decks on our planet. Biomass burning aerosol (smoke) absorbs shortwave radiation efficiently. This fundamental property implicates smoke within myriad small-scale processes with potential large-scale impacts on climate that are not yet well-understood. A coordinated, international team of scientists from the United States, United Kingdom, France, South Africa and Namibia will provide an unprecedented interrogation of this smoke-and-cloud regime from 2016 to 2018, using multiple aircraft and surface-based instrumentation suites to span much of the breadth of the southeast Atlantic

Aerosols attenuating the solar radiation collected by solar tower plants: the horizontal pathway at surface level

Aerosols attenuate the solar radiation collected by solar tower plants (STP), along two pathways: 1) the atmospheric column pathway, between the top of the atmosphere and the heliostats, resulting in Direct Normal Irradiance (DNI) changes; 2) the grazing pathway close to surface level, between the heliostats and the optical receiver

Complex refractive index and single scattering albedo of Icelandic dust in the shortwave part of the spectrum

Icelandic dust can impact the radiative budget in high-latitude regions directly by affecting light absorption and scattering and indirectly by changing the surface albedo after dust deposition. This tends to produce a positive radiative forcing. However, the limited knowledge of the spectral optical properties of Icelandic dust prevents an accurate assessment of these radiative effects. Here, the spectral single scattering albedo (SSA) and the complex refractive index (mCombining double low linen-ik) of Icelandic dust from five major emission hotspots were retrieved between 370-950 nm using online measurements of size distribution and spectral absorption (βabs) and scattering (βsca) coefficients of particles suspended in a large-scale atmospheric simulation chamber. The SSA(λ) estimated from the measured βabs and βsca increased from 0.90-0.94 at 370nm to 0.94-0.96 at 950nm in Icelandic dust from the different hotspots, which falls within the range of mineral dust from northern Africa and eastern Asia. The spectral complex refractive index was retrieved by minimizing the differences between the measured βabs and βsca and those computed using the Mie theory for spherical and internally homogeneous particles, using the size distribution data as input. The real part of the complex refractive index (n(λ)) was found to be 1.60-1.61 in the different samples and be independent of wavelength. The imaginary part (k(λ)) was almost constant with wavelength and was found to be around 0.004 at 370nm and 0.002-0.003 at 950nm. The estimated complex refractive index was close to the initial estimates based on the mineralogical composition, also suggesting that the high magnetite content observed in Icelandic dust may contribute to its high absorption capacity in the shortwave part of the spectrum. The k(λ) values retrieved for Icelandic dust are at the upper end of the reported range for low-latitude dust (e.g., from the Sahel). Furthermore, Icelandic dust tends to be more absorbing towards the near-infrared. In Icelandic dust, k(λ) between 660-950nm was 2-8 times higher than most of the dust samples sourced in northern Africa and eastern Asia. This suggests that Icelandic dust may have a stronger positive direct radiative forcing on climate that has not been accounted for in climate predictions