177,514 research outputs found
Fanny Persiani / R. Cazes
No full textAppartient à l’ensemble documentaire : IconMUS1Appartient à l’ensemble documentaire : IconMUSNumAppartient à l’ensemble documentaire : IconMUS0AutographesFac-similé
I regimi fiscali di favore per l’innovazione delle imprese tra passato, presente e futuro: dalla Strategia di Lisbona al Pillar II
No full textFungi and arsenic: tolerance and bioaccumulation by soil saprotrophic strains
No full textArsenic, a common metalloid, is worldwide recognised as important toxic element for human beings and
living organisms (1,2). Natural processes as well as anthropogenic activities contribute to its diffusion and
occurrence in the environment (1,2). Fungi, as geoactive agents, can play very important geological roles in
several processes, including decomposition, biogeochemical cycling, element biotransformations, metal and
mineral transformations, bioweathering and soil formation (3,4). Fungi can tolerate and accumulate high
concentration of arsenic and for some species, biovolatilization via methylation was reported (5).
In this research, relationships between some soil saprotrophic microfungi and arsenic in relation to growth
responses and bioaccumulation were investigated. In particular, Absidia spinosa Lendn., Purpureocillium
lilacinum (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson (formerly Paecilomyces lilacinus),
Metarhizium marquandii (Massee) Kepler, S.A. Rehner & Humber (formerly Paecilomyces marquandii) and
Cephalotrichum nanum (Ehrenb.) S. Hughes (formerly Doratomyces nanus), previously isolated from areas
with high natural As concentrations, were studied in two different cultural media, namely Malt Extract Agar
and Czapek-Dox Agar, and three different concentrations (10, 20 and 50 mg/L) of sodium arsenite (NaAsO2)
were tested. Metabolic responses and fungal tolerance to As have been investigated by tolerance indices,
namely Rt:Rc (%) and T.I. (%), based on growth data, diametric extension and dry weights, respectively.
Most of fungi resulted tolerant to all tested As concentrations, and values of tolerance indices varied
according to cultural media and As concentrations. pH medium after fungal growth was measured to study
pH variation and metabolic responses. As bioaccumulation in all fungi was observed with chemical analyses
by hydride generation atomic fluorescence spectrometry. As tolerance and bioaccumulation by fungi and
their metabolic responses shed further light in fungal geoactive roles in the environmental fate of As and
provide potential applications in bioremediation.
1) R. Singh, S. Singh, P. Parihar, V. P. Singh, S. M. Prasad (2015) Ecotox. Environ. Safe., 112, 247-270
2) A. Sarkar, B. Paul (2016) Chemosphere, 158, 37-49
3) A. Ceci, M. Kierans, S. Hillier, A. M. Persiani, G. M. Gadd (2015) Appl. Environ. Microbiol., 81, 4955-4964
4) A. Ceci, F. Pinzari, F. Russo, A. M. Persiani, G. M. Gadd (2019) Appl. Microb. Biotechnol., 103, 53-68
5) M. Singh, P.K. Srivastava, P.C. Verma, R.N. Kharwar, N. Singh, R.D. Tripathi (2015) J. Appl. Microb., 119, 1278-
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Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Biodiversity of fungi as bioresources to face diversity of soil threats
No full textDegradation threats affect soils and ecosystems, providing fundamental services for humans and living organisms. Contamination represents a major soil threat and can impair several soil functions, such as biomass production, storage, filtration and transformation of nutrients and water, and biodiversity pool (1). Despite in a smaller measure than in the past, agriculture is one of the major drivers of soil contamination, contributing with pesticides, herbicides and fertilizers added to improve crop yield. More than 3000 different types of pesticides have been used in the European agroecosystems in the past 50 years and less than 0.1% of applied pesticide to crops are estimated to reach target pests while the rest enters the environment (1). Even if contamination can reduce soil biodiversity, in microbial communities tolerant microorganisms can develop (1). Several studies have demonstrated the efficacy of indigenous fungi as a promising tool for soil bioremediation and as bioresources to reverse contamination processes in mid-term (2). The application of fungi as bioresources can also help to prevent or at least reduce the application of agrochemicals, improving at the same time quality and quantity of the yields in the contest of sustainable agricultural practices. Indeed, several soil fungi can act as plant growth promoters, both improving nutrition and stimulating protection against pests (3). Considering the pivotal role of developing nature-based solutions in coping with future challenges (e.g. world population increase, rock phosphate exhaustion), in the last years the Fungal Biodiversity Laboratory of Sapienza University of Rome focused its research mainly on selecting suitable fungal strains as bioresources for agriculture and bioremediation. The biological characterization of historically contaminated sites by DDT and HCH, respectively in Poland and in the Czech Republic, allowed to individuate indigenous fungi suitable for integrated, sustainable and cost-effective solutions for future applications in bioremediation of persistent chlorinated compounds. While, investigations on the ability of saprotrophic fungi to solubilize inorganic phosphates allowed to screen and individuate, among several strains preserved in the culture collection of Fungal Biodiversity Laboratory, a pool of strains applicable to improve phosphorus plant nutrition (4). As appear clear from these experiences, culture collections play a pivotal role in finding and screening microorganisms, which possess interesting traits as bioresources. In fact, the conservation of organisms isolated from specific environments in fungal collections, even after years, can provide useful tools and bioresources to develop new cost-effective and environmentally friendly biotechnologies and improve new feasible practices in a context of sustainable bioeconomy. References 1. Stolte, J., Tesfai, M., Øygarden, L., Kværnø, S., Keizer, J., Verheijen, F., Panagos,P., Ballabio, C. & Hessel, R., 2015. Soil threats in Europe. 2. Ceci, A., Pinzari, F., Russo, F., Persiani, A. M. & Gadd, G. M., 2019. Appl. Microbiol. Biotechnol. 103, 53–68. 3. Owen, D., Williams, A. P., Griffith, G. W. & Withers, P. J. A., 2015. Appl. Soil Ecol. 86, 41–54. 4. Ceci, A., Pinzari, F., Russo, F., Maggi, O. & Persiani, A. M., 2018. Ambio. 47, 30–40
Rischio biologico da funghi: un problema sottovalutato
No full textL’aerobiologia è una scienza multidisciplinare che studia le sorgenti, la dispersione e l’impatto del particolato biologico presente nell’atmosfera ed il suo effetto in ambienti aperti o confinati, attraverso analisi quali-quantitative.
La componente biologica aerodiffusa consta principalmente di polline, spore fungine, propaguli di licheni, gemme di muschi, cellule algali, batteri, cisti di protozoi e virus. La loro concentrazione atmosferica è molto variabile e molti sono i fattori che concorrono nel modificarla. I parametri che influenzano questa variabilità sono le condizioni meteorologiche, l’alternarsi delle stagioni, il clima e la presenza di sorgenti locali. Inoltre le particelle aerodisperse possono essere trasportate nell’aria sia singolarmente che in aggregazione con altre particelle liquide o solide e ciò, insieme ad altri fattori, contribuisce a determinare il tempo di permanenza del particolato stesso nell’atmosfera.
Il monitoraggio aerobiologico viene effettuato per evidenziare le variazioni quantitative e qualitative delle particelle aerodisperse che si verificano nel tempo e si è dimostrato un valido strumento di indagine anche nel campo dell’allergologia, al fine di conoscere la loro concentrazione a fini diagnostici e terapeutici, sia in ambienti esterni che confinati, redigere calendari pollinici e sviluppare modelli previsionali di emissione e trasporto di pollini e spore. Il decreto legislativo 626/94 sulla sicurezza sul lavoro (e sue modificazioni) introduce, per la prima volta, la valutazione del rischio causato da agenti biologici. Infatti, oltre a indicare gli agenti chimici e fisici di rischio, viene introdotto anche un elenco di agenti biologici, che comprende virus, batteri, funghi e parassiti. In questa legge, accanto alle specie di microrganismi considerati, è indicata la loro potenzialità allergenica, ma nell’ultima decina d’anni ci si è resi conto che i potenziali allergeni biologici sono molto più numerosi di quelli indicati, infatti le allergie hanno un impatto socio-economico sia per il loro continuo aumento, sia per l’inabilità temporanea o permanente al lavoro che possono comportare in moltissime categorie di lavoratori.
In questo lavoro si intende mostrare una panoramica, sia nazionale che internazionale, della situazione della valutazione del rischio biologico da spore fungine aerodisperse
The prognostic impact of the metastatic lymph nodes ratio in colorectal cancer
No full textBackground: This study was designed to validate the prognostic significance of the ratio of positive to examined lymph nodes (LNR) in patients with colorectal cancer. Methods: 218,314 patients from the SEER database and 1,811 patients from the three independent multicenter were included in this study. The patients were divided into 5 groups on a basis of previous published LNR: LNR0, patients with no metastatic lymph nodes; LNR1, patients with the LNR between 0.1 and 0.17; LNR2, patients with the LNR between 0.18 and 0.41; LNR3, patients with the LNR between 0.42 and 0.69; LNR4, patients with the LNR >0.7. The 5-year OS and CSS rate were estimated using Kaplan-Meier method and the survival difference was tested using log-rank test. Multivariate Cox analysis was used to further assess the influence of the LNR on patients' outcome. Results: The 5-year OS rate of patients within LNR0 to LNR4 group was 71.2, 55.8, 39.3, 22.6, and 14.6%, respectively (p < 0.001) in the SEER database. While the 5-year OS rate of those with LNR0 to LNR4 was 75.2, 66.1, 48.0, 34.0, and 17.7%, respectively (p < 0.001) in the international multicenter cohort. In the multivariate analysis, LNR was demonstrated to be a strong prognostic factor in patients with < 12 and ≥12 metastatic lymph nodes. Furthermore, the LNR had a similar impact on the patients' prognosis in colon cancer and rectal cancer. Conclusion: The LNR allowed better prognostic stratification than the positive node (pN) in patients with colorectal cancer and the cut-off values were well validated
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Soil fungal mycelium, abundance and species diversity as affected by fire in Mediterranean environment
No full textThe risk of accidental fires and fire severity is further destined to increase in Mediterranean European countries as a consequence of the climatic changes in progress. Fire may affect soil microbial community that regulates nutrient cycling in the terrestrial ecosystems. Previous studies have shown that fire causes an increase of total microbial biomass and activity and a reduction in functional diversity in soil of Mediterranean maquis. Aim of this study was to assess the effect of fire on soil fungi that are the main decomposers of plant litter. Fungal mycelium mass, abundance and species density were measured in burned and unburned soils. Fungal mycelium generally decreased during the first two years after fire; abundance and species density of total mycoflora decreased during the post-fire summer. Fungal mycelium, abundance and species density reached the lowest values during summer season with the lowest soil water content values, for both control and burned plots. Data suggest that fire represents, for soil fungal community, a disturbance superimposing to the soil water stress in the dry season in Mediterranean ecosystems and this effect is expected to increase in the next years on the basis of climatic change in progress
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