Prospective evaluation of BDProbeTec strand displacement amplification (SDA) system for diagnosis of tuberculosis in non-respiratory and respiratory samples.

Nucleic acid amplification techniques (NAATs) have been demonstrated to make significant improvements in the diagnosis of tuberculosis (TB), particularly in the time to diagnosis and the diagnosis of smear-negative TB. The BD ProbeTec strand displacement amplification (SDA) system for the diagnosis of pulmonary and non-pulmonary tuberculosis was evaluated. A total of 689 samples were analysed from patients with clinically suspected TB. Compared with culture, the sensitivity and specificity for pulmonary samples were 98 and 89 %, and against final clinical diagnosis 93 and 92 %, respectively. This assay has undergone limited evaluation for non-respiratory samples and so 331 non-respiratory samples were tested, identifying those specimens that were likely to yield a useful result. These were CSF (n = 104), fine needle aspirates (n = 64) and pus (n = 41). Pleural fluid (n = 47) was identified as a poor specimen. A concern in using the SDA assay was that low-positive samples were difficult to interpret; 7.8 % of specimens fell into this category. Indeed, 64 % of the discrepant results, when compared to final clinical diagnosis, could be assigned as low-positive samples. Specimen type did not predict likelihood of a sample being in the low-positive zone. Although the manufacturers do not describe the concept of a low-positive zone, we have found that it aids clinical diagnosis

Evaluation of Yeasts and Yeast Products in Larval and Adult Diets for the Oriental Fruit Fly, Bactrocera dorsalis, and Adult Diets for the Medfly, Ceratitis capitata, and the Melon Fly, Bactrocera curcurbitae

Several yeasts and yeast products were tested in adult diets for the medfly Ceratitis capitata (Wiedemann), oriental fruit fly Bactrocera dorsalis (Hendel), and melon fly, Bactrocera curcurbitae (Coquillett) (Diptera: Tephritidae) and in larval liquid diet for mass-rearing B. dorsalis. Three hydrolyzed brewer's yeasts (FNILS65, FNI200 and FNI210), one glutamine enriched yeast (GSH), one vitamin-enriched yeast (RDA500), Korea yeast, whole cell yeasts, and combinations of them were evaluated. Adult flies fed on a diet with FNI210FNI210 + GSH and RDA500 produced the highest number of eggs in all three tested fruit fly species. However, no significant difference was seen in egg hatch from flies fed on these diets with yeast in comparison to the control standard diet. When these yeasts were incorporated into a larval liquid diet with wheat germ oil, FNI200 and FNIL65 showed significantly higher pupal recovery than those from FNI210 and better adult flying and mating than those from Korea yeast. Glutamine enriched yeast enhanced fly performance, especially with FNI200 + GSH and FNILS65 + GSH, but not vitamin enriched yeast. Among the larvae reared with FNI200 + GSH, FNILS65 + GSH and torula yeast, those reared in FNILS65 + GSH diet with wheat germ oil developed the best. In order to select the most cost-effective yeast for liquid diet, FNILS65 + GSH and wheat germ oil was combined with whole cell yeast (LBI2240 series) and compared to the control diet (conventional mill feed diet currently used in the rearing facility). A ratio of 3:1 of LBI2240 and FNILS65 + wheat germ oil was selected as the most effective yeast for oriental fruit fly liquid larval diet based on cost and performance parameters

Low energy electron irradiation induced deep level defects in 6H-SiC: The implication for the microstructure of the deep levels E1/E 2

The deep level defects in 6H-SiC induced by low energy electron irradiation was investigated. Electron energies of 0.2, 0.3, 0.5 and 1.7 MeV were used to produce the deep level defects in the n-type 6H-SiC materials. The deep level transient spectroscopy (DLTS) technique, combined with isochronal thermal annealing experiments, was used for the study of the defects. It was observed that deep levels ED1, E1/E2 and Ei were created with irradiation energies of 0.3 MeV or greater than that. The deep levels were found to be associated with primary atom displacement on the C atom of SiC sublattice and had microstructure containing the carbon vacancy.published_or_final_versio

Boundary entropy of supersymmetric Janus solutions

In this paper we compute the holographic boundary entropy for half-BPS Janus deformations of the $AdS_3\times S^3\times T^4$ vacuum of type IIB supergravity. Previous work \cite{Chiodaroli:2009yw} has shown that there are two independent deformations of this sort. In one case, the six-dimensional dilaton jumps across the interface, while the other case displays a jump of axion and four-form potential. In case of a jump of the six-dimensional dilaton, it is possible to compare the holographic result with the weak-coupling result for a two-dimensional interface CFT where the radii of the compactified bosons jump across the interface. We find exact agreement between holographic and CFT results. This is to be contrasted with the holographic calculation for the non-supersymmetric Janus solution, which agrees with the CFT result only at the leading order in the jump parameter. We also examine the implications of the holographic calculation in case of a solution with a jump in the axion, which can be associated with a deformation of the CFT by the $Z_2$-orbifold twist operator.Comment: 35 pages, pdf-LaTeX, 5 figures, v2: minor changes, typos corrected, reference adde

Morphological characteristics of motor neurons do not determine their relative susceptibility to degeneration in a mouse model of severe spinal muscular atrophy

Spinal muscular atrophy (SMA) is a leading genetic cause of infant mortality, resulting primarily from the degeneration and loss of lower motor neurons. Studies using mouse models of SMA have revealed widespread heterogeneity in the susceptibility of individual motor neurons to neurodegeneration, but the underlying reasons remain unclear. Data from related motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), suggest that morphological properties of motor neurons may regulate susceptibility: in ALS larger motor units innervating fast-twitch muscles degenerate first. We therefore set out to determine whether intrinsic morphological characteristics of motor neurons influenced their relative vulnerability to SMA. Motor neuron vulnerability was mapped across 10 muscle groups in SMA mice. Neither the position of the muscle in the body, nor the fibre type of the muscle innervated, influenced susceptibility. Morphological properties of vulnerable and disease-resistant motor neurons were then determined from single motor units reconstructed in Thy.1-YFP-H mice. None of the parameters we investigated in healthy young adult mice - including motor unit size, motor unit arbor length, branching patterns, motor endplate size, developmental pruning and numbers of terminal Schwann cells at neuromuscular junctions - correlated with vulnerability. We conclude that morphological characteristics of motor neurons are not a major determinant of disease-susceptibility in SMA, in stark contrast to related forms of motor neuron disease such as ALS. This suggests that subtle molecular differences between motor neurons, or extrinsic factors arising from other cell types, are more likely to determine relative susceptibility in SMA

Epigenetics and obesity: the devil is in the details

Obesity is a complex disease with multiple well-defined risk factors. Nevertheless, susceptibility to obesity and its sequelae within obesogenic environments varies greatly from one person to the next, suggesting a role for gene × environment interactions in the etiology of the disorder. Epigenetic regulation of the human genome provides a putative mechanism by which specific environmental exposures convey risk for obesity and other human diseases and is one possible mechanism that underlies the gene × environment/treatment interactions observed in epidemiological studies and clinical trials. A study published in BMC Medicine this month by Wang et al. reports on an examination of DNA methylation in peripheral blood leukocytes of lean and obese adolescents, comparing methylation patterns between the two groups. The authors identified two genes that were differentially methylated, both of which have roles in immune function. Here we overview the findings from this study in the context of those emerging from other recent genetic and epigenetic studies, discuss the strengths and weaknesses of the study and speculate on the future of epigenetics in chronic disease research

Time to switch from CLSI to EUCAST? A Southeast Asian perspective.

Despite the importance of antimicrobial susceptibility testing (AST) to clinical management of infection and to antimicrobial resistance (AMR) surveillance, methodologies and breakpoints of the two most commonly used systems worldwide, CLSI and EUCAST, are far from harmonized. Most laboratories in resource-constrained settings such as Southeast Asia, including our own, currently follow CLSI disk diffusion AST guidelines. Many aspects of the EUCAST system, not least the freely available nature of all output, are likely to be attractive to laboratories in our setting, but published reports of the practical differences between CLSI and EUCAST methodologies are lacking. Our manuscript highlights key differences between CLSI and EUCAST disk diffusion AST methodologies, and the practical implications of adopting EUCAST guidelines in our laboratory network. We discuss potential barriers to adoption of EUCAST guidelines in resource-Clinical Microbiology and Infection constrained settings including difficulties in obtaining horse blood for media supplementation and the need for an MIC method for AST of N. gonorrhoeae. We highlight the need for a globally harmonized AST system that is practical and freely available, and we hope this commentary will be useful for laboratories considering switching between CLSI and EUCAST

Impact of CLSI and EUCAST breakpoint discrepancies on reporting of antimicrobial susceptibility and AMR surveillance.

We investigated the impact of breakpoint discrepancies between CLSI and EUCAST on susceptibility interpretation of clinical isolates at the Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos and performed a literature search to compare our findings to published reports. Zone diameters for first-line antimicrobial agents tested against non-duplicate clinical isolates of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa in 2017 were interpreted separately using EUCAST 2018 and CLSI 2018 breakpoints and greement measured. Applying EUCAST instead of CLSI breakpoints to 428 E. coli, 208 K. pneumoniae and 78 P. aeruginosa isolates would have increased rates of ciprofloxacin resistance (59.1% vs 46.5% in E. coli, 37.5% vs 13.9% in K. pneumoniae, 28.2% vs 10.3% in P. aeruginosa) and amoxicillinclavulanic acid resistance (52.3% vs 19.9% in E. coli, 35.6% vs 22.1% in K. pneumoniae). Our results are supported by a literature search which identified 20 articles whose main objective was comparing susceptibility interpretation between CLSI and EUCAST. 19/20 articles reported significant discrepancies in one or more pathogen-antimicrobial combinations, nearly always due to a reduction in susceptibility rates and/or increase in resistance rates when applying more restrictive EUCAST breakpoints. We conclude that breakpoint discrepancies between CLSI and EUCAST have a significant impact on susceptibility interpretation of clinical isolates and AMR surveillance initiatives, and highlight the need for globally harmonized clinical breakpoints

Topological Photonics

Topology is revolutionizing photonics, bringing with it new theoretical discoveries and a wealth of potential applications. This field was inspired by the discovery of topological insulators, in which interfacial electrons transport without dissipation even in the presence of impurities. Similarly, new optical mirrors of different wave-vector space topologies have been constructed to support new states of light propagating at their interfaces. These novel waveguides allow light to flow around large imperfections without back-reflection. The present review explains the underlying principles and highlights the major findings in photonic crystals, coupled resonators, metamaterials and quasicrystals.Comment: progress and review of an emerging field, 12 pages, 6 figures and 1 tabl