Performance evaluation of different coating materials in delamination for micro-milling applications on high-speed steel substrate.

This is the final version. Available from MDPI via the DOI in this record. The objective of the present work is to carry out analytical and finite element analysis for commonly used coating materials for micro-milling applications on high-speed steel substrate and evaluate the effects of different parameters. Four different coating materials were selected for micro-milling applications: titanium nitride (TiN), diamond-like carbon (DLC), aluminium titanium nitride (AlTiN) and titanium silicon nitride (TiSiN). A 3D finite element model of coating and substrate assembly was developed in Abaqus to find the Hertzian normal stress when subjected to normal load of 4 N, applied with the help of a rigid ball. The radius of the rigid ball was 200 µm. For all the coating materials, the length was 3 mm, the width was 1 mm, and the thickness was 3 µm. For the high-speed steel substrate, the length was 3 mm, the width was 1 mm, and the thickness was 50 µm. Along the length and width, coating and substrate both were divided into 26 equal parts. The deformation behaviour of all the coating materials was considered as linear-elastic and that of the substrate was characterized as elastic-plastic. The maximum normal stress developed in the FEA model was 12,109 MPa. The variation of the FEA result from the analytical result (i.e., 12,435.97 MPa is 2.63%) which is acceptable. This confirms that the FEA model of coating-substrate assembly is acceptable. The results shows that the TiSiN coating shows least plastic equivalent strain in the substrate, which serves the purpose of protecting the substrate from plastic deformation and the TiSiN of 3 micron thickness is the most optimum coating thickness for micro-milling applications

Proliferative and anti-proliferative effects of dietary levels of phytoestrogens in rat pituitary GH3/B6/F10 cells - the involvement of rapidly activated kinases and caspases

<p>Abstract</p> <p>Background</p> <p>Phytoestogens are a group of lipophillic plant compounds that can have estrogenic effects in animals; both tumorigenic and anti-tumorigenic effects have been reported. Prolactin-secreting adenomas are the most prevalent form of pituitary tumors in humans and have been linked to estrogen exposures. We examined the proliferative effects of phytoestrogens on a rat pituitary tumor cell line, GH₃/B₆/F₁₀, originally subcloned from GH₃cells based on its ability to express high levels of the membrane estrogen receptor-α.</p> <p>Methods</p> <p>We measured the proliferative effects of these phytoestrogens using crystal violet staining, the activation of several mitogen-activated protein kinases (MAPKs) and their downstream targets via a quantitative plate immunoassay, and caspase enzymatic activities.</p> <p>Results</p> <p>Four phytoestrogens (coumestrol, daidzein, genistein, and <it>trans</it>-resveratrol) were studied over wide concentration ranges. Except <it>trans</it>-resveratrol, all phytoestrogens increased GH₃/B₆/F₁₀cell proliferation at some concentration relevant to dietary levels. All four phytoestrogens attenuated the proliferative effects of estradiol when administered simultaneously. All phytoestrogens elicited MAPK and downstream target activations, but with time course patterns that often differed from that of estradiol and each other. Using selective antagonists, we determined that MAPKs play a role in the ability of these phytoestrogens to elicit these responses. In addition, except for <it>trans</it>-resveratrol, a serum removal-induced extrinsic apoptotic pathway was blocked by these phytoestrogens.</p> <p>Conclusion</p> <p>Phytoestrogens can block physiological estrogen-induced tumor cell growth <it>in vitro </it>and can also stimulate growth at high dietary concentrations in the absence of endogenous estrogens; these actions are correlated with slightly different signaling response patterns. Consumption of these compounds should be considered in strategies to control endocrine tumor cell growth, such as in the pituitary.</p

The PELskin project: part II—investigating the physical coupling between flexible filaments in an oscillating flow

The fluid-structure interaction mechanisms of a coating composed of flexible flaps immersed in a periodically oscillating channel flow is here studied by means of numerical simulation, employing the Euler-Bernoulli equations to account for the flexibility of the structures. A set of passively actuated flaps have previously been demonstrated to deliver favourable aerodynamic impact when attached to a bluff body undergoing periodic vortex shedding. As such, the present configuration is identified to provide a useful test-bed to better understand this mechanism, thought to be linked to experimentally observed travelling waves. Having previously validated and elucidated the flow mechanism in Paper 1 of this series, we hereby undertake a more detailed analysis of spectra obtained for different natural frequency of structures and different configurations, in order to better characterize the mechanisms involved in the organized motion of the structures. Herein, this wave-like behaviour, observed at the tips of flexible structures via interaction with the fluid flow, is characterized by examining the time history of the filaments motion and the corresponding effects on the fluid flow, in terms of dynamics and frequency of the fluid velocity. Results indicate that the wave motion behaviour is associated with the formation of vortices in the gaps between the flaps, which itself are a function of the structural resistance to the cross flow. In addition, formation of vortices upstream of the leading and downstream of the trailing flap is seen, which interact with the formation of the shear-layer on top of the row. This leads to a phase shift in the wave-type motion along the row that resembles the observation in the cylinder case

How participatory is parental consent in low literacy rural settings in low income countries? Lessons learned from a community based study of infants in South India

<p>Abstract</p> <p>Background</p> <p>A requisite for ethical human subjects research is that participation should be informed and voluntary. Participation during the informed consent process by way of asking questions is an indicator of the extent to which consent is informed.</p> <p>Aims</p> <p>The aims of this study were to assess the extent to which parents providing consent for children's participation in an observational tuberculosis (TB) research study in India actively participated during the informed consent discussion, and to identify correlates of that participation.</p> <p>Methods</p> <p>In an observational cohort study of tuberculosis in infants in South India, field supervisors who were responsible for obtaining informed consent noted down questions asked during the informed consent discussions for 4,382 infants who were enrolled in the study. These questions were post-coded by topic. Bivariate and multivariate analysis was conducted to examine factors associated with asking at least one question during the informed consent process.</p> <p>Results</p> <p>In total, 590 out of 4,382 (13.4%) parents/guardians asked any question during the informed consent process. We found that the likelihood of parents asking questions during the informed consent process was significantly associated with education level of either parent both parents being present, and location.</p> <p>Conclusions</p> <p>The findings have implications for planning the informed consent process in a largely rural setting with low levels of literacy. Greater effort needs to be directed towards developing simple participatory communication materials for the informed consent process. Furthermore, including both parents in a discussion about a child's participation in a research study may increase the extent to which consent is truly informed. Finally, continuing efforts need to be made to improve the communication skills of research workers with regard to explaining research processes and putting potential research participants at ease.</p

Linked read technology for assembling large complex and polyploid genomes

Background: Short read DNA sequencing technologies have revolutionized genome assembly by providing high accuracy and throughput data at low cost. But it remains challenging to assemble short read data, particularly for large, complex and polyploid genomes. The linked read strategy has the potential to enhance the value of short reads for genome assembly because all reads originating from a single long molecule of DNA share a common barcode. However, the majority of studies to date that have employed linked reads were focused on human haplotype phasing and genome assembly. Results: Here we describe a de novo maize B73 genome assembly generated via linked read technology which contains ~ 172,000 scaffolds with an N50 of 89 kb that cover 50% of the genome. Based on comparisons to the B73 reference genome, 91% of linked read contigs are accurately assembled. Because it was possible to identify errors with \u3e 76% accuracy using machine learning, it may be possible to identify and potentially correct systematic errors. Complex polyploids represent one of the last grand challenges in genome assembly. Linked read technology was able to successfully resolve the two subgenomes of the recent allopolyploid, proso millet (Panicum miliaceum). Our assembly covers ~ 83% of the 1 Gb genome and consists of 30,819 scaffolds with an N50 of 912 kb. Conclusions: Our analysis provides a framework for future de novo genome assemblies using linked reads, and we suggest computational strategies that if implemented have the potential to further improve linked read assemblies, particularly for repetitive genomes

DNA Barcoding of Recently Diverged Species: Relative Performance of Matching Methods

Recently diverged species are challenging for identification, yet they are frequently of special interest scientifically as well as from a regulatory perspective. DNA barcoding has proven instrumental in species identification, especially in insects and vertebrates, but for the identification of recently diverged species it has been reported to be problematic in some cases. Problems are mostly due to incomplete lineage sorting or simply lack of a ‘barcode gap’ and probably related to large effective population size and/or low mutation rate. Our objective was to compare six methods in their ability to correctly identify recently diverged species with DNA barcodes: neighbor joining and parsimony (both tree-based), nearest neighbor and BLAST (similarity-based), and the diagnostic methods DNA-BAR, and BLOG. We analyzed simulated data assuming three different effective population sizes as well as three selected empirical data sets from published studies. Results show, as expected, that success rates are significantly lower for recently diverged species (∼75%) than for older species (∼97%) (P<0.00001). Similarity-based and diagnostic methods significantly outperform tree-based methods, when applied to simulated DNA barcode data (P<0.00001). The diagnostic method BLOG had highest correct query identification rate based on simulated (86.2%) as well as empirical data (93.1%), indicating that it is a consistently better method overall. Another advantage of BLOG is that it offers species-level information that can be used outside the realm of DNA barcoding, for instance in species description or molecular detection assays. Even though we can confirm that identification success based on DNA barcoding is generally high in our data, recently diverged species remain difficult to identify. Nevertheless, our results contribute to improved solutions for their accurate identification

Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays

We measure the mean lifetime, tau=2/(Gamma_L+Gamma_H), and the width difference, DeltaGamma=Gamma_L-Gamma_H, of the light and heavy mass eigenstates of the B0s meson, B0sL and B0sH, in B0s -> J/psi phi decays using 1.7 fb^-1 of data collected with the CDF II detector at the Fermilab Tevatron ppbar collider. Assuming CP conservation, a good approximation for the B0s system in the Standard Model, we obtain DeltaGamma = 0.076^+0.059_-0.063 (stat.) +- 0.006 (syst.) ps^-1 and tau = 1.52 +- 0.04 (stat.) +- 0.02 (syst.) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation. Dedicated to the memory of our dear friend and colleague, Michael P. Schmid

Limits on Anomalous Triple Gauge Couplings in ppbar Collisions at sqrt{s}=1.96 TeV

We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ boson production. The boson pairs are produced in ppbar collisions at sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. In this search one W decays to leptons, and the other boson (W or Z) decays hadronically. Combining with a previously published CDF measurement of Wgamma boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.Comment: 7 pages, 3 figures. Submitted to Phys. Rev.