DMSK: A practical 2400-bps receiver for the mobile satellite service: An MSAT-X Report

The partical aspects of a 2400-bps differential detection minimum-shift-keying (DMSK) receiver are investigated. Fundamental issues relating to hardware precision, Doppler shift, fading, and frequency offset are examined, and it is concluded that the receiver's implementation at baseband is more advantageous both in cost and simplicity than its IF implementation. The DMSK receiver has been fabricated and tested under simulated mobile satellite environment conditions. The measured receiver performance in the presence of anomalies pertinent to the link is presented in this report. Furthermore, the receiver behavior in a band-limited channel (GMSK) is also investigated. The DMSK receiver performs substantially better than a coherent minimum-shift-keying (MSK) receiver in a heavily fading environment. The DMSK radio is simple and robust, and results in a lower error floor than its coherent counterpart. Moreover, this receiver is suitable for burst-type signals, and its recovery from deep fades is fast

Naval History by Conspiracy Theory: The British Admiralty before the First World War and the Methodology of Revisionism

Revisionist interpretations of British naval policy in the Fisher era claim that an elaborate smoke screen was created to hide the Royal Navy’s real policies; while documents showing the true goals were systematically destroyed. By asserting this, revisionists are able to dismiss those parts of the documentary record that contradict their theories, while simultaneously excusing the lack of evidence for their theories by claiming it has been destroyed. This article shows that this methodology is misleading and untenable

High pressure X-ray preionized TEMA-CO2 laser

The construction of a high-pressure (up to 20 atm) transversely excited CO2 laser using transverse X-ray preionization is described. High pressure operation was found to be greatly improved in comparison to UV-preionized systems. Homogeneous discharges have been achieved in the pressure range 5–20 atm, yielding a specific laser output in the order of 35 J/l

Myosin II activity dependent and independent vinculin recruitment to the sites of E-cadherin-mediated cell-cell adhesion

<p>Abstract</p> <p>Background</p> <p>Maintaining proper adhesion between neighboring cells depends on the ability of cells to mechanically respond to tension at cell-cell junctions through the actin cytoskeleton. Thus, identifying the molecules involved in responding to cell tension would provide insight into the maintenance, regulation, and breakdown of cell-cell junctions during various biological processes. Vinculin, an actin-binding protein that associates with the cadherin complex, is recruited to cell-cell contacts under increased tension in a myosin II-dependent manner. However, the precise role of vinculin at force-bearing cell-cell junctions and how myosin II activity alters the recruitment of vinculin at quiescent cell-cell contacts have not been demonstrated.</p> <p>Results</p> <p>We generated vinculin knockdown cells using shRNA specific to vinculin and MDCK epithelial cells. These vinculin-deficient MDCK cells form smaller cell clusters in a suspension than wild-type cells. In wound healing assays, GFP-vinculin accumulated at cell-cell junctions along the wound edge while vinculin-deficient cells displayed a slower wound closure rate compared to vinculin-expressing cells. In the presence of blebbistatin (myosin II inhibitor), vinculin localization at quiescent cell-cell contacts was unaffected while in the presence of jasplakinolide (F-actin stabilizer), vinculin recruitment increased in mature MDCK cell monolayers.</p> <p>Conclusion</p> <p>These results demonstrate that vinculin plays an active role at adherens junctions under increased tension at cell-cell contacts where vinculin recruitment occurs in a myosin II activity-dependent manner, whereas vinculin recruitment to the quiescent cell-cell junctions depends on F-actin stabilization.</p

Adverse effects of superactivated charcoal administered to healthy volunteers.

OBJECTIVES: Activated charcoal is frequently administered to drug overdose patients, who may experience nausea and vomiting secondary to the drug overdose. Drinking a charcoal slurry orally may be difficult for them necessitating a gastric tube. The purpose of this study is to report the frequency of adverse effects from oral superactivated charcoal (SAC) given to healthy volunteers. METHODS: Healthy adult study subject volunteers were given a single 2000 mg (first 13 subjects) or 3000 mg (remaining 35 subjects) dose of acetaminophen. Subjects were randomized to receive no charcoal (ctrl) or 75 grams of SAC administered orally in a slurry 3 hours following the acetaminophen dose. The adverse effects of both groups were recorded and compared. RESULTS: There were 48 study subject runs. The mean age was 27.4 years (SD6.5). SAC was administered to 24 subjects. Adverse effect rates were as follows (*one-tail p 71kg) completed SAC consumption significantly faster than the 12 lighter subjects (18.7 vs 7.8 minutes, p = 0.04, single sided). This comparison included the two subjects (both lighter) who did not finish SAC consumption, so this difference was no longer significant when these two subjects were removed. CONCLUSIONS: Superactivated charcoal consumption is associated with significant adverse effects in some healthy volunteers, which may impede a drug overdose patient's ability to willingly drink charcoal slurry in a reasonable period of time.P20 RR11091/RR/NCRR NIH HHS/United State

Stacks and D-Brane Bundles

In this paper we describe explicitly how the twisted ``bundles'' on a D-brane worldvolume in the presence of a nontrivial B field, can be understood in terms of sheaves on stacks. We also take this opportunity to provide the physics community with a readable introduction to stacks and generalized spaces.Comment: 24 pages, LaTeX; v2: references adde

Aerodynamic Forces Acting on Ahmed-Type Vehicles under Fluctuating Headwind Conditions

Aerodynamic forces of Ahmed-type road vehicles subjected to atmospheric fluctuation were studied in an advanced wind tunnel with programmable settings enabling the generation of pulsating wind speeds. The experiments were performed with a time-averaged airflow speed of approximately 13 m/s, with the fluctuating speed ranging from 2.58 to 2.90 m/s, and periods ranging from 1.5 to 5.0 s. The results of the time-dependent drag and lift forces acting on the vehicle were compared with those under steady wind conditions. Further, the influence of the rear slant angle of the Ahmed model on the forces was addressed. The fluctuation in wind speed showed a greater effect on the aerodynamic forces than predicted. The amplitude of the drag force under the pulsating wind became larger in a vehicle having a shape that experienced a large drag force under steady wind conditions. It is concluded that even under fluctuating wind conditions, there exists a critical angle of 30 at which the vehicle experiences either high or low fluid forces

Measurement of the bb¯ dijet cross section in pp collisions at s√=7 TeV with the ATLAS detector

The dijet production cross section for jets containing a b-hadron (b-jets) has been measured in proton–proton collisions with a centre-of-mass energy of s√=7 TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2fb−1. The cross section is measured for events with two identified b-jets with a transverse momentum pT>20 GeV and a minimum separation in the η–ϕ plane of ΔR=0.4. At least one of the jets in the event is required to have pT>270 GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization

Search for dark matter produced in association with a Higgs boson decaying to two bottom quarks in pp collisions at √s=8 TeV with the ATLAS detector

This article reports on a search for dark matter pair production in association with a Higgs boson decaying to a pair of bottom quarks, using data from 20.3  fb−1 of pp collisions at a center-of-mass energy of 8 TeV collected by the ATLAS detector at the LHC. The decay of the Higgs boson is reconstructed as a high-momentum b¯b system with either a pair of small-radius jets, or a single large-radius jet with substructure. The observed data are found to be consistent with the expected Standard Model backgrounds. Model-independent upper limits are placed on the visible cross sections for events with a Higgs boson decaying into b¯b and large missing transverse momentum with thresholds ranging from 150 to 400 GeV. Results are interpreted using a simplified model with a Z′ gauge boson decaying into different Higgs bosons predicted in a two-Higgs-doublet model, of which the heavy pseudoscalar Higgs decays into a pair of dark matter particles. Exclusion limits are also presented for the mass scales of various effective field theory operators that describe the interaction between dark matter particles and the Higgs boson