Modelling and experimental investigation of carangiform locomotion for control

We propose a model for planar carangiform swimming based on conservative equations for the interaction of a rigid body and an incompressible fluid. We account for the generation of thrust due to vortex shedding through controlled coupling terms. We investigate the correct form of this coupling experimentally with a robotic propulsor, comparing its observed behavior to that predicted by unsteady hydrodynamics. Our analysis of thrust generation by an oscillating hydrofoil allows us to characterize and evaluate certain families of gaits. Our final swimming model takes the form of a control-affine nonlinear system

The oral microbiome and adverse pregnancy outcomes.

Significant evidence supports an association between periodontal pathogenic bacteria and preterm birth and preeclampsia. The virulence properties assigned to specific oral pathogenic bacteria, for example, Fusobacterium nucleatum, Porphyromonas gingivalis, Filifactor alocis, Campylobacter rectus, and others, render them as potential collaborators in adverse outcomes of pregnancy. Several pathways have been suggested for this association: 1) hematogenous spread (bacteremia) of periodontal pathogens; 2) hematogenous spread of multiple mediators of inflammation that are generated by the host and/or fetal immune response to pathogenic bacteria; and 3) the possibility of oral microbial pathogen transmission, with subsequent colonization, in the vaginal microbiome resulting from sexual practices. As periodontal disease is, for the most part, preventable, the medical and dental public health communities can address intervention strategies to control oral inflammatory disease, lessen the systemic inflammatory burden, and ultimately reduce the potential for adverse pregnancy outcomes. This article reviews the oral, vaginal, and placental microbiomes, considers their potential impact on preterm labor, and the future research needed to confirm or refute this relationship

Regulation of protein kinase B and glycogen synthase kinase-3 by insulin and beta-adrenergic agonists in rat epididymal fat cells - Activation of protein kinase B by wortmannin-sensitive and -insensittve mechanisms

Previous studies using L6 myotubes have suggested that glycogen synthase kinase-3 (GSK-3) is phosphoryl ated and inactivated in response to insulin by protein kinase B (PKB, also known as Akt or RAG) (Cross, D, A, E., Alessi, D, R., Cohen, P., Andjelkovic, M., and Hemmings, B, A. (1995) Nature 378, 785-789), In the present study, marked increases in the activity of PKB have been shown to occur in insulin-treated rat epididymal fat cells with a time course compatible with the observed decrease in GSK-3 activity, Isoproterenol, acting primarily through beta(3)-adrenoreceptors, was found to decrease GSK-3 activity to a similar extent (approximately 50%) to insulin, However, unlike the effect of insulin, the inhibition of GSK by isoproterenol was not found to be sensitive to inhibition by the phosphatidylinositol 3'-kinase inhibitors, wortmannin or LY 294002, The change in GSK-3 activity brought about by isoproterenol could not be mimicked by the addition of permeant cyclic AMP analogues or forskolin to the cells, although at the concentrations used, these agents were able to stimulate lipolysis. Isoproterenol, but again not the cyclic AMP analogues, was found to increase the activity of PKB, although to a lesser extent than insulin. While wortmannin abolished the stimulation of PKB activity by insulin, it was without effect on the activation seen in response to isoproterenol, The activation of PKB by isoproterenol was not accompanied by any detectable change in the electrophoretic mobility of the protein on SDS-polyacrylamide gel electrophoresis. It would therefore appear that distinct mechanisms exist for the stimulation of PKB by insulin and isoproterenol in rat fat cells

Technical note: Fourier transform infrared spectral analysis in tandem with 31P nuclear magnetic resonance spectroscopy elaborates detailed insights into phosphate partitioning during skimmed milk microfiltration and diafiltration

peer-reviewedOur previous study identified peaks in the 31P nuclear magnetic resonance (31P NMR) spectra of skim milk, denoting the interaction of different phosphate species such as inorganic and casein-associated phosphate during the separation of colloidal and serum phases of skim milk by microfiltration (MF) and diafiltration (DF). In the current study, we investigated the same samples generated by the aforementioned separation using attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy analysis. The results confirmed that the technique was not only capable of differentiating between the mineral equilibrium of the casein phosphate nanocluster (CPN) and milk serum, but also complemented the application of 31P NMR. An ATR-FTIR broad band in the region of 1,055 to 1,036 cm−1 and a specific band at 1,076 cm−1 were identified as sensitive to the repartitioning of different phosphate species in milk in accordance with the 31P NMR signals representing casein-associated phosphate and inorganic phosphate in the serum. A third ATR-FTIR signal at 1,034 cm−1 in milk, representing precipitated inorganic calcium phosphate, had not previously been detected by 31P NMR. Thus, the results indicate that a combination of ATR-FTIR and 31P NMR spectroscopies may be optimally used to follow mineral and protein phase changes in milk during membrane processing

Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures

Brown’s vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with blade–vortex interactions, and thus the accuracy with which the acoustic signature of a helicopter rotor can be predicted. The vorticity transport model can accurately resolve the structure of the wake of the rotor and allows significant flexibility in the way that the blade loading can be represented. The Second Higher-Harmonic Control Aeroacoustics Rotor Test was initiated to provide experimental insight into the acoustic signature of a rotor in cases of strong blade–vortex interaction. Predictions of two models for the local blade aerodynamics are compared with the test data. A marked improvement in accuracy of the predicted high-frequency airloads and acoustic signature is obtained when a lifting-chord model for the blade aerodynamics is used instead of a lifting-line-type approach. Errors in the amplitude and phase of the acoustic peaks are reduced, and the quality of the prediction is affected to a lesser extent by the computational resolution of the wake, with the lifting-chord model producing the best representation of the distribution of sound pressure below the rotor

Impact of the Quick-Response Code Based In-Class Assignments on Students Engagement and Retention

The paper describes a teaching technique alternative to online-based student response systems. We explore the potential of quick response (QR) code sheets as a tool for formative assessment, feedback, as well as a way to increase class engagement, student participation, information retention, and as a method to develop communication skills. The technique is neither institution nor course bound and can be implemented in classes of numerous sizes and levels. While it resembles more traditional teaching methods than computerized student response systems, it is student centered and accommodates digital natives’ approach to information gathering

Timed Insemination vs. Modified Estrus Detection in Beef Heifers

Th e objective of this study was to compare a modified estrus detection and fixed time AI vs. no estrus detection and fixed time AI on subsequent pregnancy rates. Yearling heifers were estrus synchronized and AI at 72 ± 2 h after prostaglandin injection. In one group estrus was not detected and all heifers received gonadotropin releasing hormone at the fixed- time AI; in the other group estrus was detected at 58 ± 2 and 70 ± 2 h after prostaglandin and inseminated in the following order at 72 ± 2 h: heifers in estrus at 58 h, heifers in estrus at 70 h, and heifers not appearing in estrus at either observation. Similar AI conception and final pregnancy rates were achieved without the added labor of estrus detection

A novel NGS library preparation method to characterize native termini of fragmented DNA.

Biological and chemical DNA fragmentation generates DNA molecules with a variety of termini, including blunt ends and single-stranded overhangs. We have developed a Next Generation Sequencing (NGS) assay, XACTLY, to interrogate the termini of fragmented DNA, information traditionally lost in standard NGS library preparation methods. Here we describe the XACTLY method, showcase its sensitivity and specificity, and demonstrate its utility in in vitro experiments. The XACTLY assay is able to report relative abundances of all lengths and types (5' and 3') of single-stranded overhangs, if present, on each DNA fragment with an overall accuracy between 80-90%. In addition, XACTLY retains the sequence of each native DNA molecule after fragmentation and can capture the genomic landscape of cleavage events at single nucleotide resolution. The XACTLY assay can be applied as a novel research and discovery tool for fragmentation analyses and in cell-free DNA

Using Range Information to Detect Spoofing in Platoons of Vehicles

GNSS are well known to be accurate providers of position information across the globe. Because of high signal availabilities, capable/robust receivers, and well-populated satellite constellations, operators typically believe that the location information provided by their GNSS receiver is correct. More sophisticated users are concerned with the integrity of the derived location information. Attacks on GNSS availability and integrity are known as jamming and spoofing. Jamming involves the transmission of signals that interfere with GNSS reception so that the receiver is unable to provide a position or time solution; various methods to detect jamming, and possibly overcome it, have been considered in the literature. Spoofing is the transmission of counterfeit GNSS signals so as to mislead a GNSS receiver into reporting an inaccurate position or time. If undetected, spoofing might be much more dangerous than a jamming attack. A variety of approaches have been proposed in the literature to recognize spoofing. Of interest here are methods which compare GNSS information to measurements available from other, non-GNSS sensors. Recent ION conferences have included several examinations of combining GNSS and non-GNSS data toward spoof detection. This paper considers the use of range-only information to detect GNSS spoofing of a platoon of vehicles equipped with inter-vehicle communications: a statistical model of the problem is developed in which the spoofer is assumed to have limited geographical impact (i.e. only spoofs a subset, nominally one, of the vehicles in the platoon); under a Neyman-Pearson formulation the (generalized) likelihood ratio test to fuse the GNSS and range measurements is presented; examples are included to demonstrate the resulting performance