Propagation of Neutron Cross Section, Fission Yield, and Decay Data Uncertainties in Depletion Calculations

Propagation of nuclear data uncertainties in reactor calculations is interesting for design purposes and libraries evaluation. Previous versions of the GRS XSUSA library propagated only neutron cross section uncertainties. We have extended XSUSA uncertainty assessment capabilities by including propagation of fission yields and decay data uncertainties due to the their relevance in depletion simulations. We apply this extended methodology to the UAM6 PWR Pin-Cell Burnup Benchmark, which involves uncertainty propagation through burnup

Observation of electron transfer mediated decay in aqueous solution

Photoionization is at the heart of X ray photoelectron spectroscopy XPS , which gives access to important information on a sample s local chemical environment. Local and non local electronic decay after photoionization in which the refilling of core holes results in electron emission from either the initially ionized species or a neighbour, respectively have been well studied. However, electron transfer mediated decay ETMD , which involves the refilling of a core hole by an electron from a neighbouring species, has not yet been observed in condensed phase. Here we report the experimental observation of ETMD in an aqueous LiCl solution by detecting characteristic secondary low energy electrons using liquid microjet soft XPS. Experimental results are interpreted using molecular dynamics and high level ab initio calculations. We show that both solvent molecules and counterions participate in the ETMD processes, and different ion associations have distinctive spectral fingerprints. Furthermore, ETMD spectra are sensitive to coordination numbers, ion solvent distances and solvent arrangemen

Potential therapeutic applications of microbial surface-activecompounds

Numerous investigations of microbial surface-active compounds or biosurfactants over the past two decades have led to the discovery of many interesting physicochemical and biological properties including antimicrobial, anti-biofilm and therapeutic among many other pharmaceutical and medical applications. Microbial control and inhibition strategies involving the use of antibiotics are becoming continually challenged due to the emergence of resistant strains mostly embedded within biofilm formations that are difficult to eradicate. Different aspects of antimicrobial and anti-biofilm control are becoming issues of increasing importance in clinical, hygiene, therapeutic and other applications. Biosurfactants research has resulted in increasing interest into their ability to inhibit microbial activity and disperse microbial biofilms in addition to being mostly nontoxic and stable at extremes conditions. Some biosurfactants are now in use in clinical, food and environmental fields, whilst others remain under investigation and development. The dispersal properties of biosurfactants have been shown to rival that of conventional inhibitory agents against bacterial, fungal and yeast biofilms as well as viral membrane structures. This presents them as potential candidates for future uses in new generations of antimicrobial agents or as adjuvants to other antibiotics and use as preservatives for microbial suppression and eradication strategies

Elucidation of the RamA Regulon in Klebsiella pneumoniae Reveals a Role in LPS Regulation

Klebsiella pneumoniae is a significant human pathogen, in part due to high rates of multidrug resistance. RamA is an intrinsic regulator in K. pneumoniae established to be important for the bacterial response to antimicrobial challenge; however, little is known about its possible wider regulatory role in this organism during infection. In this work, we demonstrate that RamA is a global transcriptional regulator that significantly perturbs the transcriptional landscape of K. pneumoniae, resulting in altered microbe-drug or microbe-host response. This is largely due to the direct regulation of 68 genes associated with a myriad of cellular functions. Importantly, RamA directly binds and activates the lpxC, lpxL-2 and lpxO genes associated with lipid A biosynthesis, thus resulting in modifications within the lipid A moiety of the lipopolysaccharide. RamA-mediated alterations decrease susceptibility to colistin E, polymyxin B and human cationic antimicrobial peptide LL-37. Increased RamA levels reduce K. pneumoniae adhesion and uptake into macrophages, which is supported by in vivo infection studies, that demonstrate increased systemic dissemination of ramA overexpressing K. pneumoniae. These data establish that RamA-mediated regulation directly perturbs microbial surface properties, including lipid A biosynthesis, which facilitate evasion from the innate host response. This highlights RamA as a global regulator that confers pathoadaptive phenotypes with implications for our understanding of the pathogenesis of Enterobacter, Salmonella and Citrobacter spp. that express orthologous RamA proteins

Screening of cucurbitaceous rootstocks against root-knot nematodes (Meloidogyne spp.) and soilborne pathogens (Fusarium spp. and Pythium spp.)

Abstract. One of the main problems in cucumber greenhouse production is control of soil-borne pathogens and root-knot nematodes. Grafting cucumber plants represent an alternative method to control that is safety and does not pollute the environment. Immune forms to these pests are not established, but in some studies are found sources belong to Cucurbitaceae family that possesses resistant or tolerant response. The aim of this study was to screening cucurbitaceous rootstock genotypes to root-knot nematodes (Meloidogyne spp.), Fusarium spp. and Pythium spp. During the period 2014-2015 in the Maritsa Vegetable Crops Research Institute, Plovdiv thirteen breeding materials belonging to Cucurbitaceae family were tested: Gergana, Kiara F , TG, TD (Cucumis 1 sativus); CM 720, SB-2, SB-3, Turban (C. maxima); Muskatna 51-17, Carotina, (C. moschata); Turban × Muskatna 51-17, CM 720 × Carotina (C. maxima × C. moschata F ); Local (Lagenaria siceraria). Two parallel trials were performed in greenhouse conditions. Local isolates of pests were used for the screening 1 tests. Plants were grown in pots and inoculated with mixed infection of Fusarium spp. and Pythium spp. In trial with root-knot nematodes the plants were inoculated with 6000 second stage juveniles (J2). The response was recorded 60 days after inoculation. Results indicated that Carotina was resistant when the pots were inoculated with Meloidogyne spp. Resistant response to soil-borne pathogens possesses cucumber lines TG and TD and Lagenaria. Tested cucurbitaceous material can be used directly for grafting cucumber plants, and also be able to used as a basis for starting breeding program for rootstocks with tolerance to Meloidogyne spp., Fusarium spp. and Pythium sp