1,078 research outputs found
Heavy Quark Dynamics in the QGP
We assess transport properties of heavy quarks in the Quark-Gluon Plasma
(QGP) that show a strong non-perturbative behavior. A T-matrix approach based
on a potential taken from lattice QCD hints at the presence of heavy-quark (HQ)
resonant scattering with an increasing strength as the temperature, ,
reaches the critical temperature, T_c \simeq 170 \; \MeV for deconfinement
from above. The implementation of HQ resonance scattering along with a
hadronization via quark coalescence under the conditions of the plasma created
in heavy-ion collisions has been shown to correctly describe both the nuclear
modification factor, , and the elliptic flow, , of single
electrons at RHIC and have correctly predicted the of D mesons at LHC
energy.Comment: 10 pages, 4 figures, Proceedings of EPIC@LHC Workshop, 6-8 July, Bar
Micromycetes on bark and wood of Podocarpus parlatorei (Podocarpaceae) from Argentina. VIII. Rosellinia (Xylariaceae, Ascomycota)
Durante un estudio de la biodiversidad de micromicetes que crecen en la corteza y madera de Podocarpus parlatorei, se encontraron tres especies de Rosellinia. Se registra por primera vez a Rosellinia franciscae para Sudamérica y a Rosellinia starbaeckii para la Argentina. Se amplía el área de distribución de Rosellinia aquila desde una región templada hacia una región subtropical del noroeste del país. Se brindan descripciones, ilustraciones, comentarios, datos de distribución geográfica y hábitat para todas las especies.During biodiversity studies on micromycetes growing on bark and decorticated wood of Podocarpus parlatorei, three species belonging to Rosellinia were collected. Rosellinia franciscae is reported for the first time for South America and Rosellinia starbaeckii is a new record from Argentina. The distribution area of Rosellinia aquila in Argentina is enlarged from a temperate region to a subtropical region in the northwest of the country. Descriptions, illustrations, data on geographical distribution, habitat, and notes on the fungi described are provided.Fil: Catania, Myriam del V.. Fundación Miguel Lillo; ArgentinaFil: Romero, Andrea Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botanica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botanica; Argentin
Microbes and Persistent Organic Pollutants in the Marine Environment
Marine pollution has increased reaching the entire marine environment, from the surface to the deepest sediment, and has become more concerning in the last 70 years. Persistent organic pollutants (POPs) are a fraction of ocean waste that includes, among the others, polycyclic aromatic hydrocarbons (PAHs) and plastic polymers. These chemicals have an extremely long half-life, and (bio)accumulate and damage the marine flora and fauna, and, ultimately, human health. Some organisms have evolved enzymes to attack POPs in the environment and transform them into biomass and CO2. Several microorganisms degrade many POPs in relatively short time. A wide variety of bacteria has been isolated with different techniques, and key catabolic enzymes used to degrade the most persistent oil hydrocarbon fractions have been identified. For plastic waste, there is less evidence of microbial degradation, but a few recent studies are revealing that a biodegradation potential exists for some of the most recalcitrant plastic polymers as well. The scientific community is focusing on microorganisms and their enzymes for POP uptake and removal from the environment, while searching novel biopolymers (also from microbiological origin) to substitute oil-derived plastics
A Logical Approach to Cooperative Information Systems
``Cooperative information system management'' refers to the capacity of several computing systems to communicate and cooperate in order to acquire, store, manage, query data and knowledge. Current solutions to the problem of cooperative information management are still far from being satisfactory. In particular, they lack the ability to fully model cooperation among heterogeneous systems according to a declarative style. The use of a logical approach to model all aspects of cooperation seems very promising. In this paper, we de®ne a logical language able to support cooperative queries, updates and update propagation. We model the sources of information as deductive databases, sharing the same logical language to ex- press queries and updates, but containing independent, even if possibly related, data. We use the Obj-U-Datalog (E. Bertino, G. Guerrini, D. Montesi, Toward deductive object data- bases, Theory and Practice of Object Systems 1 (1) (1995) 19±39) language to model queries and transactions in each source of data. Such language is then extended to deal with active rules in the style of Active-U-Datalog (E. Bertino, B. Catania, V. Gervasi, A. Ra aet a, Ac- tive-U-Datalog: Integrating active rules in a logical update language, in: B. Freitag, H. Decker, M. Kifer, A. Voronkov (Eds.), LBCS 1472: Transactions and Change in Login Databases, 1998, pp. 106±132), interpreted according to the PARK semantics proposed in G. Gottlob, G. Moerkotte, V.S. Subrahmanian (The PARK semantics for active rules, in: P.M.G. Apers, M. Bouzeghoub, G. Gardarin (Eds.), LNCS 1057: Proceedings of the Fifth International Con- ference on Extending Database Technology, 1996, pp. 35±55). By using active rules, a system can e ciently perform update propagation among di erent databases. The result is a logical environment, integrating active and deductive rules, to perform update propagation in a cooperative framework
Application of Precision Agriculture for the Sustainable Management of Fertilization in Olive Groves
Olive tree growing (Olea europaea L.) has considerably increased in the last decades, as has the consumption of extra virgin olive oil in the world. Precision agriculture is increasingly being applied in olive orchards as a new method to manage agronomic variability with the aim of providing individual plants with the right input amount, limiting waste or excess. The objective of this study was to develop a methodology on a GIS platform using GEOBIA algorithms in order to build prescription maps for variable rate (VRT) nitrogen fertilizers application in an olive orchard. The fertilization plan was determined for each tree by applying its own nitrogen balance, taking into account the variability of nitrogen in soil, leaf, production, and actual biometric and spectral conditions. Each olive tree was georeferenced using the S7-G Stonex instrument with real-time kinematic RTK positioning correction and the trunk cross section area (TCSA) was measured. Soil and leaves were sampled to study nutrient variability. Soil and plant samples were analyzed for all major physical and chemical properties. Spectral data were obtained using a multispectral camera (DJI multispectral) carried by an unmanned aerial vehicle (UAV) platform (DJI Phantom4). The biometric characteristics of the plants were extracted from the achieved normalized vegetation index (NDVI) map. The obtained prescription map can be used for variable rate fertilization with a tractor and fertilizer spreader connected via the ISOBUS system. Using the proposed methodology, the variable rate application of nitrogen fertilizer resulted in a 31% reduction in the amount to be applied in the olive orchard compared to the standard dose
Blue biotechnology: oil bioremediation using hydrocarbon-degrading bacteria immobilized on biodegradable membranes
A novel bioremediation system to clean up oil contaminated water was developed combining hydrocarbon (HC) degrading bacteria immobilized and polylactic acid (PLA) or polycaprolactone (PCL) membranes prepared by electrospinning. The bioremediation efficiency was tested on crude oil using highly performant HC degrading bacterial strains isolated from marine and soil environments. The membrane morphology, the microbial adhesion and proliferation were evaluated using scanning electron microscopy (SEM). The SEM analysis highlighted that the fibers of the electrospun mats were in nanoscale with a similar diameter size distribution. The electrospun membranes exhibited high oil absorption capacity (q): approximately q = 40 g/g for PLA and q = 20 g/g for PCL. The bacterial strains were able to attach to the PLA and PCL membranes after 48h, reaching high proliferation and biofilm formation within the whole structure in 5 days. The biodegradation efficiency of the bacteria-membrane systems was tested by GC-FID analysis and compared with planktonic cells after 5 and 10 days incubation. The bacterial immobilization is a promoting factor for biodegradation and a new tool to be developed for bioremediation of aquatic systems
De novo design of antimicrobial and antibiofilm peptides starting from desert truffle Tirmania pinoyi peptides
With the aim of discovering new routes in the research of antimicrobials, we focused on polypeptide-
enriched extracts derived from edible desert truffle mushroom Tirmania pinoyi. The extracts
showed an interesting activity with MIC=50 μg/mL against Staphylococcus aureus ATCC 29213
and Pseudomonas aeruginosa ATCC 15442. Through mass spectrometry analysis (RP-HPLC/
nESI-MS/MS) the following eight novel peptides FDVVPKTAANFRAL, AVTVGASTLADERA,
FLVGGASLKPEF, VARIFAVFNDTF, HLVDEPQNLLK, LGEYGFQNALLR, FAVNGGCAKET,
SREDLHPKL were detected. To characterize them online websites were used: IAMPpred,
DPBAAS, Cell-PPD, ToxinPred, HemoPI, PeptideCutter and HLP. The analysis indicated that
some peptides showed negative or neutral charge, hydrophobic ratio between 42% and 67%,
Boman Index < 2.25 kCal/mol. According to the “APD3: Antimicrobial Peptide Calculator and
Predictor” tool of the Antimicrobial Peptide Database (APD) similarities (around 30-40%) with
known antimicrobial peptides (AMPs) identified in amphibians were also detected. In contrast, the
predicted antimicrobial, antifungal and antibiofilm activity was not significant.
In order to improve biological and physico-chemical properties, the sequences of natural peptides
were modified using APD3, by replacing some hydrophilic and negative charged amino acids
with hydrophobic and positive ones. The derivative sequences (GWDVVPKTWWKFRAL,
KWTWGASTLAKKRA, FLRGGWSLKPKF, KWRIFWVFNKTF, HLVKRWQNLLK,
KGKYRFWNALLR, FARWGGCAKRT, SRKWLHPWL) showed net positive charge between
+2 and +4, hydrophobic ratio between 42% and 48%, Boman Index < 2.25 kCal/mol and high
stability. Moreover, the predicted antimicrobial, antifungal and antibiofilm activity was high, without
toxic or hemolytic effects.
In conclusion, bioinformatic analysis has demonstrated that novel peptides discovered in T. pinoyi
may be considered new platforms for the design of novel antimicrobial and antibiofilm peptides to
counteract multi-drug resistant pathogens
Fever with perinasal and tongue lesions: A diagnostic challenge
The diagnosis may be challenging, and high suspicion index should be maintained in immunosuppressed patients with unusual mucocutaneous lesions, even in non-endemic areas for mucocutaneous leishmaniasis
Cover crop impact on soil organic carbon, nitrogen dynamics and microbial diversity in a mediterranean semiarid vineyard
Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season; soil respiration, determined by incubation experiments, microbial biomass and diversity was analyzed after CC burial. The microbial diversity was evaluated by bacterial and fungal automated ribosomal intergenic spacer analysis (ARISA) and high-throughput sequencing of 16SrDNA. CC increased nitrate content and, although it had no relevant effect on SOC, almost doubled its active microbial component, which contributes to SOC stabilization. An unexpected stability of the microbial communities under different soil managements was assessed, fungal diversity being slightly enhanced under CT while bacterial diversity increased under CC. The complete nitrifying genus Nitrospira and plant growth-promoting genera were increased under CC, while desiccation-tolerant genera were abundant in CT. Findings showed that temporary CC applied in semiarid vineyards does not optimize the provided ecosystem services, hence a proper management protocol for dry environments should be set up
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