Faster Family-wise Error Control for Neuroimaging with a Parametric Bootstrap

In neuroimaging, hundreds to hundreds of thousands of tests are performed across a set of brain regions or all locations in an image. Recent studies have shown that the most common family-wise error (FWE) controlling procedures in imaging, which rely on classical mathematical inequalities or Gaussian random field theory, yield FWE rates that are far from the nominal level. Depending on the approach used, the FWER can be exceedingly small or grossly inflated. Given the widespread use of neuroimaging as a tool for understanding neurological and psychiatric disorders, it is imperative that reliable multiple testing procedures are available. To our knowledge, only permutation joint testing procedures have been shown to reliably control the FWER at the nominal level. However, these procedures are computationally intensive due to the increasingly available large sample sizes and dimensionality of the images, and analyses can take days to complete. Here, we develop a parametric bootstrap joint testing procedure. The parametric bootstrap procedure works directly with the test statistics, which leads to much faster estimation of adjusted \emph{p}-values than resampling-based procedures while reliably controlling the FWER in sample sizes available in many neuroimaging studies. We demonstrate that the procedure controls the FWER in finite samples using simulations, and present region- and voxel-wise analyses to test for sex differences in developmental trajectories of cerebral blood flow

Nanovesicles loaded with origanum onites and satureja thymbra essential oils and their activity against food-borne pathogens and spoilage microorganisms

Food poisoning is a common cause of illness and death in developing countries. Essential oils (EOs) could be effective and safe natural preservatives to prevent and control bacterial contamination of foods. However, their high sensitivity and strong flavor limit their application and biological effectiveness. The aim of this study was firstly the chemical analysis and the antimicrobial evaluation of the EOs of Origanum onites L. and Satureja thymbra L. obtained from Symi island (Greece), and, secondly, the formulation of propylene glycol-nanovesicles loaded with these EOs to improve their antimicrobial properties. The EOs were analyzed by GC-MS and their chemical contents are presented herein. Different nanovesicles were formulated with small average sizes, high homogeneity, and optimal ζ-potential. Microscopic observation confirmed their small and spherical shape. Antibacterial and antifungal activities of the formulated EOs were evaluated against food-borne pathogens and spoilage microorganisms compared to pure EOs. Propylene glycol-nanovesicles loaded with O. onites EO were found to be the most active formulation against all tested strains. Additionally, in vitro studies on the HaCaT cell line showed that nanovesicles encapsulated with EOs had no toxic effect. The present study revealed that both EOs can be used as alternative sanitizers and preservatives in the food industry, and that their formulation in nanovesicles can provide a suitable approach as food-grade delivery system

Controlling Legionella pneumophila in water systems at reduced hot water temperatures with copper and silver ionization

Background: Hospital-acquired Legionnaires’ disease is associated with the presence of Legionella pneumophila in hospital water systems. In the United Kingdom, the Department of Health recommends maintaining hot water temperatures >55°C and cold water temperatures <20°C at the point of delivery to prevent proliferation of L pneumophila in water systems. In this study, we evaluated the efficacy of copper and silver ionization to control L pneumophila at deliberately reduced hot water temperatures (43°C) within a newly installed water system in a new building linked to a large health care facility in the United Kingdom. / Methods: One thousand, five hundred ninety-eight water samples were collected between September 2011 and June 2017. Samples were tested using accredited methods for L pneumophila, copper and silver ion levels, and total viable counts. Energy consumption and water usage data were also collected to permit carbon emission calculations. / Results: The results of 1,598 routine samples from September 2011 to June 2017, and the recordings of temperatures at outlets in this facility, demonstrated effective (100%) L pneumophila control throughout the study period with an average hot water temperature of 42°C. The energy savings and reduction of carbon emissions were calculated to amount to 33% and 24%, respectively, compared to an equivalent temperature-controlled system. Water system management interventions were required to achieve consistently adequate levels of copper and silver across outlets. / Conclusions: This study demonstrated that it is possible to control L pneumophila independent of temperature when copper and silver ionization is introduced into a new building in conjunction with an appropriately managed water system

Effect of the Position in the Build Chamber on the Fatigue Strength of Additively Manufactured Maraging Steel MS1

The quality of additively produced parts and the achievable mechanical response may be affected by several factors, such as build orientation, heat treatment, or machining. A further rarely investigated factor is the position of the built part in the chamber with respect to inert gas flow. Previous studies have highlighted that the interaction between gas flow and laser track may induce an intense vaporization with consequent lack of fusion, particle entrainment, drop in density and denudation of the produced part, which is likely to detrimentally affect mechanical properties. This study addresses the effect of part position on the fatigue strength of heat-treated maraging steel MS1 produced by an EOSINT M280 machine in a nitrogen environment. Novelty arises from the lack of studies in this field, especially under fatigue. A factorial plan with subsequent statistical analysis highlighted that positioning the part upstream with respect to the gas flow leads to a slightly lower fatigue strength; however, no significant differences are observed. The failure mode, involving initiation from subsurface porosities of the same size, is also unaffected. Finally, a fatigue limit of 26% of the ultimate tensile strength is found, which is consistent with previous outcomes

Fatigue response of additively manufactured as-built 15-5 PH stainless steel and effects of machining and thermal and surface treatments

Additively produced 15-5 PH stainless steel has wide industrial applications, but the combined effects of heat treatment, machining, and shot-peening and their order have not been deeply investigated. This topic is addressed here by a 2-by-3 experimental plan that has involved S–N curve and fatigue limit determination, using vertically built cylindrical samples, tested under rotating bending. The obtained responses have been analyzed by an ANOVA-based statistical approach for comparison of fatigue trends. Results indicate that heat treatment without machining may be even detrimental for fatigue due to embrittlement. Conversely, machining with subsequent shot-peening, even without heat treatment, has a remarkable impact and leads to a doubled fatigue strength with respect to as-built material. This strength is also quite close to that achievable for wrought material. The study has been completed by micrography and fractography, to reveal the dependence of microstructure, crack initiation sites, and failure mode on the performed treatments

Fatigue response of additively manufactured Maraging Stainless Steel CX and effects of heat treatment and surface finishing

This paper deals with the novel topic of the fatigue response of additively manufactured Maraging Stainless Steel CX. A two-by-two factorial plan was arranged, to experimentally assess the effects of heat treatment and machining on the fatigue strength in both finite and infinite life domains. The two factors were regarded as on–off, taking the untreated unmachined condition as a reference for comparisons. Cylindrical specimens with vertical build orientation were involved in the fatigue campaign under four-point rotating bending. The results indicate that the fatigue strength may be remarkably incremented (up to five times) with respect to the as received conditions, especially thanks to surface smoothing and taking advantage of a very low porosity level. Heat treatment strengthening mechanisms were also interpreted in the light of optical and electron microscope observations. Fatigue enhancement arises from precipitate size increment throughout the conducted heat treatment, although the fracture mode turns to be more brittle

Metasecretome-selective phage display approach for mining the functional potential of a rumen microbial community

BACKGROUND: In silico, secretome proteins can be predicted from completely sequenced genomes using various available algorithms that identify membrane-targeting sequences. For metasecretome (collection of surface, secreted and transmembrane proteins from environmental microbial communities) this approach is impractical, considering that the metasecretome open reading frames (ORFs) comprise only 10% to 30% of total metagenome, and are poorly represented in the dataset due to overall low coverage of metagenomic gene pool, even in large-scale projects. RESULTS: By combining secretome-selective phage display and next-generation sequencing, we focused the sequence analysis of complex rumen microbial community on the metasecretome component of the metagenome. This approach achieved high enrichment (29 fold) of secreted fibrolytic enzymes from the plant-adherent microbial community of the bovine rumen. In particular, we identified hundreds of heretofore rare modules belonging to cellulosomes, cell-surface complexes specialised for recognition and degradation of the plant fibre. CONCLUSIONS: As a method, metasecretome phage display combined with next-generation sequencing has a power to sample the diversity of low-abundance surface and secreted proteins that would otherwise require exceptionally large metagenomic sequencing projects. As a resource, metasecretome display library backed by the dataset obtained by next-generation sequencing is ready for i) affinity selection by standard phage display methodology and ii) easy purification of displayed proteins as part of the virion for individual functional analysis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-356) contains supplementary material, which is available to authorized users

Micromeria thymifolia Essential Oil Suppresses Quorum-sensing Signaling in Pseudomonas aeruginosa

The chemical composition, antimicrobial and antiquorum sensing activity of the essential oil of Micromeria thymifolia (Scop.) Fritsch were investigated. Limonene, piperitone epoxide and piperitenone epoxide were found as the main constituents using a gas chromatography-mass spectrometry technique. In vitro antimicrobial activity of the oil was tested against six bacterial and seven fungal strains and high antimicrobial potential was noticed. Minimum inhibitory concentration varied from 0.031 mg/mL to 0.5 mg/mL for bacterial and 0.062 mg/mL to 0.5 mg/mL for fungal strains. The antiquorum properties of the essential oil were evaluated on Pseudomonas aeruginosa PAO1. The oil was tested at subMiC concentrations for anti-quorum sensing activity. The analyses on quorum-sensing functions have been carried out by evaluating twitching and swarming of bacterial cultures and the total amount of pyocyanin production produced by P. aeruginosa. This study showed that M thymifolia essential oil exhibited antiquorum sensing activity and may be used as an antipathogenic drug