Performance modeling of a manufacturing cell with a single material transporter: An approximation

We consider a flexible manufacturing system with a number of workstations, a single material transporter, and a common storage space of finite capacity. The material handling delay times are explicitly considered in the model and assumed to follow a two-stage Coxian distribution. The material processing times on a workstation also have a two-stage Coxian distribution. The routing of parts within the system follows a Markov chain. An approximate performance model is developed and the results are compared with the exact or simulation results. We also investigate how this performance model compares to a simulation with deterministic routing and processing times. Finally, we study the effect, on the performance measures, of ignoring the material transporter or of modeling the transporter as a central server with aggregation of routing information.     

Aging of mesenchymal stem cell in vitro

Background  

A hot new topic in medical treatment is the use of mesenchymal stem cells (MSC) in therapy. The low frequency of this subpopulation of stem cells in bone marrow (BM) necessitates their in vitro expansion prior to clinical use. We evaluated the effect of long term culture on the senescence of these cells.     

The Crosstalk Between Brain Mediators Regulating Food Intake Behavior in Birds: A Review

International Journal of Peptide Research and Therapeutics - Appetite is controlled by a complex system of central and peripheral signals interacting to modulate the ingestion response. Several...     

Response of Pseudomonas tolaasii,the causal agent of mushroom brown blotch disease to the volatile compounds produced by endofungal bacteria

Volatile organic compounds (VOCs) produced by bacteria have significant potential to control phytopathogens. In this study, the VOCs produced by endofungal bacteria Pseudomonas sp. Bi1, Bacillus sp. De3, Pantoea sp. Ma3 and Pseudomonas sp. De1 isolated from wild growing mushrooms were evaluated in vitro for their antagonistic activity against Pseudomonas tolaasii Pt18, the causal agent of mushroom brown blotch disease. The gas chromatography–mass spectrometry (GC–MS) analysis revealed that strains Pseudomonas sp. Bi1, Pseudomonas sp. De1, Bacillus sp. De3 and Pantoea sp. Ma3 produced eight, sixteen, nine, and twelve VOCs, respectively. All antagonistic endofungal bacteria produced VOCs which significantly reduced brown blotch symptoms on mushroom caps and inhibited the growth of P. tolaasii Pt18 at the varying levels. Scanning electron microscopy revealed severe morphological changes in cells of P. tolaasii Pt18 following exposure to the VOCs of Pseudomonas sp. Bi1 and De1. Furthermore, The VOCs produced by endofungal bacteria significantly reduced swarming, swimming, twitching, chemotaxis motility and biofilm formation by P. tolaasii Pt18 cells, which are essential contributors to pathogenicity. This is to first report about the inhibition effects of VOCs produced by antagonistic bacteria on virulence traits of P. tolaasii. Our findings provide new insights regarding the potential of antibacterial VOCs as a safe fumigant to control mushroom brown blotch disease.

     

Effect of biotic and abiotic elicitors on production of betulin and betulinic acid in the hairy root culture of Betula pendula Roth

Abstract

Betulin (B) and betulinic acid (BA) are two triterpenoids with a wide range of biological and medicinal activities in different organs of Betula pendula. This research aimed to increase the accumulation of B and BA in the hairy root culture of B. pendula by seven biotic and abiotic elicitors. Hairy root was induced in the stem’s inner bark of B. pendula using the C58C1 strain in the WPM (Woody Plant Medium). The effects of different concentrations of elicitors and different time of root harvest in hairy root culture of B. pendula showed that highest level of growth index (GI), B, and BA was acquired in treated hairy roots with chitosan (CTS), chlorocholine chloride (CCC) and chitosan nano-fiber (CTS NF). Highest GI of B. pendula hairy roots was 13 that was obtained in the roots treated with CTS 150?mg l^?1 on the 8th day. The highest content of BA was 1.3?mg g^?1 DW after treatment with 1?mg l^?1CCC on the 4th and 6th days and 200?mg l^?1CTS NF on the 10th day. The highest B content (0.94?mg g^?1DW) was obtained in the treated hairy root by 2?mg l^?1 CCC after 4 and 6?days.     

Evolutionarily conserved motifs and modules in mitochondrial protein–protein interaction networks

Advances in organelle interactomics have led to new insights into organelle functions. In this study, we considered the common mitochondrial PIN of four evolutionarily distant eukaryotic species, namely Homo sapiens, Mus musculus, Drosophila melanogaster and Caenorhabditis elegans. By comparative interactomics analysis of mitochondrial PINs in these organisms, five conserved modules were identified. Modules comprise the main mitochondrial tasks, including proteins involved in translation process, mitochondrial import inner membrane proteins, TCA cycle enzymes, mitochondrial electron transport chain, and metabolic enzymes. Furthermore, we reemphasize that subgraphs of network, i.e., motifs and themes, may represent evolutionarily conserved topological units which are biologically significant.     

Are Treponema pallidum Specific Rapid and Point-of-Care Tests for Syphilis Accurate Enough for Screening in Resource Limited Settings? Evidence from a Meta-Analysis

Background

Rapid and point-of-care (POC) tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP) specific reference standards.

Methods

Five electronic databases (1980–2012) were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit.

Results

In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI) for the sensitivities of popular tests were: i) Determine, 90.04% (80.45, 95.21), ii) SD Bioline, 87.06% (75.67, 94.50), iii) VisiTect, 85.13% (72.83, 92.57), and iv) Syphicheck, 74.48% (56.85, 88.44), while specificities were: i) Syphicheck, 99.14% (96.37, 100), ii) Visitect, 96.45% (91.92, 99.29), iii) SD Bioline, 95.85% (89.89, 99.53), and iv) Determine, 94.15% (89.26, 97.66). In whole blood samples, sensitivities were: i) Determine, 86.32% (77.26, 91.70), ii) SD Bioline, 84.50% (78.81, 92.61), iii) Syphicheck, 74.47% (63.94, 82.13), and iv) VisiTect, 74.26% (53.62, 83.68), while specificities were: i) Syphicheck, 99.58% (98.91, 99.96), ii) VisiTect, 99.43% (98.22, 99.98), iii) SD Bioline, 97.95%(92.54, 99.33), and iv) Determine, 95.85% (92.42, 97.74).

Conclusions

Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource limited settings with poor access to laboratories or screening for syphilis.