Rigidity properties of a three-way prestressed segmented ceramic plate

Rigidity properties of three way prestressed segmented ceramic plat

Bending-stiffness Properties of a Prestressed Segmented Ceramic Plate

Bending, twisting, and Poisson stiffness of prestressed segmented ceramic plat

Precise Switching of Flagellar Gene Expression in Escherichia Coli by the FlgM–FliA Regulatory Network

A remarkable feature of flagellar synthesis in Escherichia coli is that gene expression is sequential and coupled to the assembly process. The interaction of two key proteins, the flagellar sigma factor FliA and its anti-sigma factor FlgM serves as a major checkpoint in the assembly process that temporally separates middle and late gene expression. While the sequential nature within each gene class has been studied using large-scale transcriptional data, much less is known about the timing controlled by the checkpoint mechanism. In this article, we analyze timing, sensitivity and robustness of the FlgM–FliA core regulatory mechanism based on quantitative molecule data and a detailed stochastic as well as reduced deterministic reaction kinetics model. We find that the pool of free anti-sigma factor FlgM, accumulated during middle gene expression, acts as a molecular timer that determines the delay between successful completion of the hook basal body subunit and the start of expression of flagellar filament proteins. Furthermore, we find that the number of free FliA molecules needs to be tightly controlled for a precise switch from middle to late gene expression. A sensitivity analysis based on the reduced reaction kinetics model reveals that the checkpoint mechanism is very sensitive to changes in levels of competing sigma factors, allowing the bacterium to rapidly adapt to a changing environment. In addition, we find that the reduced model also shows a high sensitivity to the effective synthesis rates of FliA and FlgM. However, this high sensitivity does not generally carry over to the original parameters of transcriptional and translational processes in the detailed model. As a consequence, care has to be taken whenever interpreting results from the robustness analysis of reaction kinetic models comprising lumped or effective parameters

Supplementation of lactobacillus-fermented rapeseed meal in broiler diet reduces Campylobacter jejuni cecal colonization and limits the l-tryptophan and l-histidine biosynthesis pathways

BACKGROUND: Campylobacter jejuni (C. jejuni), a widely distributed global foodborne pathogen, primarily linked with contaminated chicken meat, poses a significant health risk. Reducing the abundance of this pathogen in poultry meat is challenging but essential. This study assessed the impact of Lactobacillus-fermented rapeseed meal (LFRM) on broilers exposed to C. jejuni-contaminated litter, evaluating growth performance, Campylobacter levels, and metagenomic profile. RESULTS: By day 35, the litter contamination successfully colonized broilers with Campylobacter spp., particularly C. jejuni. In the grower phase, LFRM improved (P &lt; 0.05) body weight and daily weight gain, resulting in a 9.2% better feed conversion ratio during the pre-challenge period (the period before artificial infection; days 13–20). The LFRM also reduced the C. jejuni concentration in the ceca (P &lt; 0.05), without altering alpha and beta diversity. However, metagenomic data analysis revealed LFRM targeted a reduction in the abundance of C. jejuni biosynthetic pathways of l-tryptophan and l-histidine and gene families associated with transcription and virulence factors while also possibly leading to selected stress-induced resistance mechanisms. CONCLUSION: The study demonstrated that LFRM inclusion improved growth and decreased cecal Campylobacter spp. concentration and the relative abundance of pivotal C. jejuni genes. Performance benefits likely resulted from LFRM metabolites. At the molecular level, LFRM may have reduced C. jejuni colonization, likely by decreasing the abundance of energy transduction and l-histidine and l-tryptophan biosynthesis genes otherwise required for bacterial survival and increased virulence.</p

Sloan/Johnson-Cousins/2MASS Color Transformations for Cool-Stars

We present multi-color transformations and photometric parallaxes for a sample of 40 low mass dwarfs selected from the Sloan Digital Sky Survey (SDSS) and the General Catalog of Trigonometric Stellar Parallaxes. Our sample was re-observed at the Manastash Ridge Observatory (MRO) using both Sloan and Johnson-Cousin filters and color transformations between the two photometric systems were derived. A subset of the sample had previously measured Johnson-Cousins photometry and parallaxes as well as 2MASS photometry. We observed these stars at MRO using Sloan filters and used these data to derive photometric parallax relations as well as SDSS/Johnson-Cousins/2MASS color transformations. We present the data and derived transformations for use in future low mass star studies.Comment: 7 pages, Accepted for publication in PAS

A Comparison of Low-Gravity Measurements On-Board Columbia During STS-40

The first NASA Spacelab Life Sciences mission (SLS-1) flew 5 June to 14 June 1991 on the orbiter Columbia (STS-40). The purpose of the mission was to investigate the human body\u27s adaptation to the low-gravity conditions of space flight and the body\u27s readjustment after the mission to the 1 g environment of earth. In addition to the life sciences experiments manifested for the Spacelab module, a variety of experiments in other scientific disciplines flew in the Spacelab and in Get Away Special (GAS) Canisters on the GAS Bridge Assembly. Several principal investigators designed and flew specialized accelerometer systems to better assess the results of their experiments by means of a low-gravity environment characterization. This was also the first flight of the NASA Microgravity Science and Applications Division (MSAD) sponsored Space Acceleration Measurement System (SAMS) and the first flight of the NASA Orbiter Experiments Office (OEX) sponsored Orbital Acceleration Research Experiment accelerometer (OARE). We present a brief introduction to seven STS-40 accelerometer systems and discuss and compare the resulting data. During crew sleep periods, acceleration magnitudes in the 10-6 to 10-5 g range were recorded in the Spacelab module and on the GAS Bridge Assembly. Magnitudes increased to the 10-4 g level during periods of nominal crew activity. Vernier thruster firings caused acceleration shifts on the order of 10-4 g and primary thruster firings caused accelerations as great as 10-2 g. Frequency domain analysis revealed typical excitation of Orbiter and Spacelab structural modes at 3.5, 4.7, 5.2, 6.2, 7, and 17 Hz

Assessment of a Large-Scale Unbiased Malignant Pleural Effusion Proteomics Study of a Real-Life Cohort

Background: Pleural effusion (PE) is common in advanced-stage lung cancer patients and is related to poor prognosis. Identification of cancer cells is the standard method for the diagnosis of a malignant PE (MPE). However, it only has moderate sensitivity. Thus, more sensitive diagnostic tools are urgently needed. Methods: The present study aimed to discover potential protein targets to distinguish malignant pleural effusion (MPE) from other non-malignant pathologies. We have collected PE from 97 patients to explore PE proteomes by applying state-of-the-art liquid chromatography-mass spectrometry (LC-MS) to identify potential biomarkers that correlate with immunohistochemistry assessment of tumor biopsy or with survival data. Functional analyses were performed to elucidate functional differences in PE proteins in malignant and benign samples. Results were integrated into a clinical risk prediction model to identify likely malignant cases. Sensitivity, specificity, and negative predictive value were calculated. Results: In total, 1689 individual proteins were identified by MS-based proteomics analysis of the 97 PE samples, of which 35 were diagnosed as malignant. A comparison between MPE and benign PE (BPE) identified 58 differential regulated proteins after correction of the p-values for multiple testing. Furthermore, functional analysis revealed an up-regulation of matrix intermediate filaments and cellular movement-related proteins. Additionally, gene ontology analysis identified the involvement of metabolic pathways such as glycolysis/gluconeogenesis, pyruvate metabolism and cysteine and methionine metabolism. Conclusion: This study demonstrated a partial least squares regression model with an area under the curve of 98 and an accuracy of 0.92 when evaluated on the holdout test data set. Furthermore, highly significant survival markers were identified (e.g., PSME1 with a log-rank of 1.68 × 10−6 ).info:eu-repo/semantics/publishedVersio

A Method for Combining Isolates of Phytophthora sojae to Screen for Novel Sources of Resistance to Phytophthora Stem and Root Rot in Soybean

Soybean cultivars with specific single resistance genes (Rps) are grown to reduce yield loss due to Phytophthora stem and root rot caused by the oomycete pathogen Phytophthora sojae. To identify novel Rps loci, soybean lines are often screened several times, each time with an isolate of P. sojae that differs in virulence on various Rps genes. The goal of this study was to determine whether several isolates of P. sojae that differ in virulence on Rpsgenes could be combined into a single source of inoculum and used to screen soybean lines for novel Rps genes. A set of 14 soybean differential lines, each carrying a specific Rps gene, was inoculated with three isolates of P. sojae, which differed in virulence on 6 to 10 Rps genes, individually or in a 1:1:1 mixture. Inoculum containing the 1:1:1 mixture of isolates was virulent on 13 Rps genes. The mixed-inoculum method was used to screen 1,019 soybean accessions in a blind assay for novel sources of resistance. In all, 17% of Glycine max accessions and 11% of G. soja accessions were resistant (≤30% dead plants), suggesting that these accessions may carry a novel Rps gene or genes. Advantages of combining isolates into a single source of inoculum include reduced cost, ability to screen soybean germplasm with inoculum virulent on all known Rps genes, and ease of identifying novel sources of resistance. This study is a precursor to identifying novel sources of resistance to P. sojae in soybean using RXLR effectors