1,615 research outputs found
Study to develop improved methods to detect leakage in fluid systems, phase 3
Research was undertaken to design and fabricate a prototype flight weight ultrasonic contact sensor leak detection system and to perform the necessary testing to collect enough data to establish design parameters and develop necessary baseline operating characteristics. The prototype system consists of five channels and is capable for monitoring frequencies from 1 KHz to 110 KHz
Fluctuating shapes of the fireballs in heavy-ion collisions
We argue that energy and momentum deposition from hard partons into
quark-gluon plasma induces an important contribution to the final state hadron
anisotropies. We also advocate a novel method of Event Shape Sorting which
allow to analyse the azimuthal anisotropies of the fireball dynamics in more
detail. A use of the method in femtoscopy is demonstrated.Comment: contribution to Proceedings of the XXIV Baldin seminar on high energy
physics problems (Relativistic Nuclear Physics and Quantum Chromodynamics),
Sept. 17-22, 2018, Dubna, Russia, 6 page
Enteric parasites and AIDS
OBJECTIVE: To report on the importance of intestinal parasites in patients with AIDS, showing relevant data in the medical literature, with special emphasis on epidemiology, diagnosis and treatment of enteroparasitosis, especially cryptosporidiasis, isosporiasis, microsporidiasis and strongyloidiasis. DESIGN: Narrative review.OBJETIVO: Relatar a importância das parasitoses intestinais em pacientes com Aids, mostrando dados relevantes na literatura médica, com enfoque em especial, abordando a epidemiologia, diagnóstico e tratamento das enteroparasitoses, principalmente da criptosporidíase, isosporíase, microsporidíase e estrongiloidíase.TIPO DE ESTUDO: Revisão narrativa.Instituto de Infectologia Emílio RibasUniversidade Federal de São Paulo (UNIFESP)University of Mogi das CruzesEscola Paulista de MedicinaUNIFESP, EPMSciEL
Hydrodynamics of embedded planets' first atmospheres - III. The role of radiation transport for super-Earth planets
The population of close-in super-Earths, with gas mass fractions of up to 10%
represents a challenge for planet formation theory: how did they avoid runaway
gas accretion and collapsing to hot Jupiters despite their core masses being in
the critical range of ? Previous
three-dimensional (3D) hydrodynamical simulations indicate that atmospheres of
low-mass planets cannot be considered isolated from the protoplanetary disc,
contrary to what is assumed in 1D-evolutionary calculations. This finding is
referred to as the recycling hypothesis. In this Paper we investigate the
recycling hypothesis for super-Earth planets, accounting for realistic 3D
radiation hydrodynamics. Also, we conduct a direct comparison in terms of the
evolution of the entropy between 1D and 3D geometries. We clearly see that 3D
atmospheres maintain higher entropy: although gas in the atmosphere loses
entropy through radiative cooling, the advection of high entropy gas from the
disc into the Bondi/Hill sphere slows down Kelvin-Helmholtz contraction,
potentially arresting envelope growth at a sub-critical gas mass fraction.
Recycling, therefore, operates vigorously, in line with results by previous
studies. However, we also identify an "inner core" -- in size 25% of
the Bondi radius -- where streamlines are more circular and entropies are much
lower than in the outer atmosphere. Future studies at higher resolutions are
needed to assess whether this region can become hydrodynamically-isolated on
long time-scales.Comment: 16 pages, 12 figures, accepted for publication at MNRA
Production of Secondary Metabolites in Extreme Environments: Food- and Airborne Wallemia spp. Produce Toxic Metabolites at Hypersaline Conditions
<div><p>The food- and airborne fungal genus <i>Wallemia</i> comprises seven xerophilic and halophilic species: <i>W</i>. <i>sebi</i>, <i>W</i>. <i>mellicola</i>, <i>W</i>. <i>canadensis</i>, <i>W</i>. <i>tropicalis</i>, <i>W</i>. <i>muriae</i>, <i>W</i>. <i>hederae</i> and <i>W</i>. <i>ichthyophaga</i>. All listed species are adapted to low water activity and can contaminate food preserved with high amounts of salt or sugar. In relation to food safety, the effect of high salt and sugar concentrations on the production of secondary metabolites by this toxigenic fungus was investigated. The secondary metabolite profiles of 30 strains of the listed species were examined using general growth media, known to support the production of secondary metabolites, supplemented with different concentrations of NaCl, glucose and MgCl<sub>2</sub>. In more than two hundred extracts approximately one hundred different compounds were detected using high-performance liquid chromatography-diode array detection (HPLC-DAD). Although the genome data analysis of <i>W</i>. <i>mellicola</i> (previously <i>W</i>. <i>sebi sensu lato</i>) and <i>W</i>. <i>ichthyophaga</i> revealed a low number of secondary metabolites clusters, a substantial number of secondary metabolites were detected at different conditions. Machine learning analysis of the obtained dataset showed that NaCl has higher influence on the production of secondary metabolites than other tested solutes. Mass spectrometric analysis of selected extracts revealed that NaCl in the medium affects the production of some compounds with substantial biological activities (wallimidione, walleminol, walleminone, UCA 1064-A and UCA 1064-B). In particular an increase in NaCl concentration from 5% to 15% in the growth media increased the production of the toxic metabolites wallimidione, walleminol and walleminone.</p></div
Aerobiology over Antarctica – a new initiative for atmospheric ecology
The role of aerial dispersal in shaping patterns of biodiversity remains poorly understood, mainly due to a lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. It has been long known that the rate of dispersal to an ecosystem can significantly influence ecosystem dynamics, and that aerial transport has been identified as an important source of biological input to remote locations. With the considerable effort devoted in recent decades to understanding atmospheric circulation in the south-polar region, a unique opportunity has emerged to investigate the atmospheric ecology of Antarctica, from regional to continental scales. This concept note identifies key questions in Antarctic microbial biogeography and the need for standardized sampling and analysis protocols to address such questions. A consortium of polar aerobiologists is established to bring together researchers with a common interest in the airborne dispersion of microbes and other propagules in the Antarctic, with opportunities for comparative studies in the Arctic
Antimicrobial efficiency of functionalized cellulose fibres as potential medical textiles
This chapter presents an overview of methods for cellulose fibres functionalization in order to introduce antimicrobial activity. In view the need for ecologically friendly textiles antimicrobial finishing is introduced, together with some strategies for the functionalization of fibres using biodegradable polysaccharides such as the use of chitosan. Additionally,the methods used for the microbiological testing of these fibres are discussed and the current disadvantages of these methods indicated. Moreover, a new strategy for a reliable methodology regarding the antimicrobial testing of oriented fibre-based polymers such as cellulose is discussed, which could also be useful within several other polymer industrial fields
Synergistic interactions in microbial biofilms facilitate the establishment of opportunistic pathogenic fungi in household dishwashers
Biofilms formed on rubber seals in dishwashers harbor diverse microbiota. In this study, we focussed on the microbial composition of bacteria and fungi, isolated from a defined area of one square centimeter of rubber from four domestic dishwashers and assessed their abilities to in vitro multispecies biofilm formation. A total of 80 isolates (64 bacterial and 16 fungal) were analyzed. Multiple combinations of bacterial isolates from each dishwasher were screened for synergistic interactions. 32 out of 140 tested (23%) four-species bacterial combinations displayed consistent synergism leading to an overall increase in biomass, in all experimental trails. Bacterial isolates from two of the four dishwashers generated a high number of synergistically interacting four-species consortia. Network based correlation analyses also showed higher co-occurrence patterns observed between bacterial members in the same two dishwasher samples, indicating cooperative effects. Furthermore, two synergistic fourspecies bacterial consortia were tested for their abilities to incorporate an opportunistic fungal pathogen, Exophiala dermatitidis and their establishment as biofilms on sterile ethylene propylene diene monomer M-class (EPDM) rubber and polypropylene (PP) surfaces. When the bacterial consortia included E. dermatitidis, the overall cell numbers of both bacteria and fungi increased and a substantial increase in biofilm biomass was observed. These results indicate a novel phenomenon of cross kingdom synergy in biofilm formation and these observations could have potential implications for human health
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