Investigation of Pilots\u27 Visual Entropy and Eye Fixations for Simulated Flights Consisted of Multiple Take-Offs and Landings

Eye movement characteristics might provide insights on pilots\u27 mental fatigue during prolonged flight. The visual entropy, eye fixation numbers, and eye fixation durations of ten novice pilots and ten expert pilots were analyzed for a four-hour simulated flight task consisting of four consecutive flight legs. Each flight leg lasted approximately one hour and contained five flight phases: takeoff, climb, cruise, descend, and landing. The pilots maneuvered the simulated B-52 aircraft following instrument flight rules (IFR) in a moderate-fidelity Microsoft Flight Simulator environment. Our results indicate that experts’ eye movement characteristics were significantly different from those of novices. In detail, novices\u27 eye movements were more random, produced longer eye fixation durations, and had fewer eye fixation numbers on the areas of interest (AOIs) than the experts. In addition, the repetitive task (i.e., four consecutive flights) significantly impacted the eye movement characteristics for both experts and novices. Visual entropy and eye fixation duration increased, while eye fixation numbers decreased for both groups as the repetition index increased. Finally, the flight phases also affected eye movement characteristics. The results show that both experts\u27 and novices\u27 visual entropies were relatively higher during climb, cruise, and descend phases, whereas those were relatively lower during the takeoff and landing phases. The present results provide a foundation for us to better understand the similarities and dissimilarities of eye movement characteristics between the experts and novices for a prolonged flight. Lastly, potential scaffolding training methods and pilot anomaly alerting systems, derived from such eye movements, are introduced

Cholesterol granuloma in the wall of a mandibular dentigerous cyst: a rare case report

Cholesterol granuloma is an inflammatory reaction to cholesterol crystals deposition. It may develop in a variety of sites including the middle ear, mastoid process or even paranasal sinuses. Very few cases of cholesterol granuloma occurring in the jaws were reported. This report presents a rare case of cholesterol granuloma that developed in the wall of a large mandibular dentigerous cyst. The condition was treated with hemimandibulectomy followed by reconstruction with a free fibular flap

Enhanced production of tropane alkaloids in transgenic Scopolia parviflora hairy root cultures over-expressing putrescine N-methyl transferase (PMT) and hyoscyamine-6β-hydroxylase (H6H)

Scopolia parviflora adventitious roots were metabolically engineered by co-expression of the two gene putrescine N-methyl transferase (PMT) and hyoscyamine-6β-hydroxylase (H6H) cDNAs with the aid of Agrobacterium rhizogenes. The transformed roots developed into morphologically distinct S. parviflora PMT1 (SpPMT1), S. parviflora PMT1 (SpPMT2), and S. parviflora H6H (SpH6H) transgenic hairy root lines. Consequent to the introduction of these key enzyme genes, the production of the alkaloids hyoscyamine and scopolamine was enhanced. Among the transgenic hairy root lines, SpPMT2 line possessed the highest growth index. The treatment of transgenic hairy roots with growth regulators further enhanced the production of scopolamine. Thus, the results suggest that PMT1, PMT2, and H6H genes may not only be involved in the metabolic regulation of alkaloid production but also that these genes may play a role in the root development

MRI size assessment of cerebral microvasculature using diffusion-time-dependent stimulated-echo acquisition: A feasibility study in rodent

In this study, a stimulated-echo (STE) method was employed to robustify the cerebral vessel size estimation nearair-tissue, bone-tissue interfaces, and large vessels. The proposed solution is to replace the relaxation rate changefrom gradient-echo (GRE) with that from STE with long diffusion time after the injection of an intravascularcontrast agent, superparamagnetic iron oxide nanoparticles. The corresponding diffusion length of STE is shorterthan the length over which the unwanted macroscopicfield inhomogeneities but is still longer than the corre-lation length of thefields induced by small vessels. Therefore, the unwantedfield inhomogeneities are refocused,while preserving microscopic susceptibility contrast from cerebral vessels. The mean vessel diameter (dimen-sionless) derived from the diffusion-time-varying STE method was compared to the mean vessel diameter ob-tained by a conventional spin-echo (SE) and GRE combination based on Monte-Carlo proton diffusion simulationsand in vivo rat experiments at 7 T. The in vivo mean vessel diameter from the MRI experiments was directlycompared to available reference mouse brain vasculature obtained by a knife-edge scanning microscope (KESM),which is considered to be the gold standard. Monte-Carlo simulation revealed that SE and GRE-based MRrelaxation rate changes (??R2and??R2*, respectively) can be enhanced using single STE-based MR relaxation ratechange (??RSTE) by regulating diffusion time, especially for small vessels. The in vivo mean vessel diameter fromthe STE method demonstrated a closer agreement with that from the KESM compared to the combined SE andGRE method, especially in the olfactory bulb and cortex. This study demonstrates that STE relaxation rate changescan be used as consistent measures for assessing small cerebral microvasculature, where macroscopicfield in-homogeneity is severe and signal contamination from adjacent large vessels is significant

Leptogenesis and Low-energy Observables

We relate leptogenesis in a class of theories to low-energy experimental observables: quark and lepton masses and mixings. With reasonable assumptions motivated by grand unification, one can show that the CP-asymmetry parameter takes a universal form. Furthermore the dilution mass is related to the light neutrino masses. Overall, these models offer a natural explanation for a lepton asymmetry in the early universe.Comment: 10 pages, revised discussion on light neutrino masse

Nonmesonic weak decay spectra of Λ4^4_\LambdaHe

To comprehend the recent Brookhaven National Laboratory experiment E788 on $^4_\Lambda$He, we have outlined a simple theoretical framework, based on the independent-particle shell model, for the one-nucleon-induced nonmesonic weak decay spectra. Basically, the shapes of all the spectra are tailored by the kinematics of the corresponding phase space, depending very weakly on the dynamics, which is gauged here by the one-meson-exchange-potential. In spite of the straightforwardness of the approach a good agreement with data is acheived. This might be an indication that the final-state-interactions and the two-nucleon induced processes are not very important in the decay of this hypernucleus. We have also found that the $\pi+K$ exchange potential with soft vertex-form-factor cutoffs $(\Lambda_\pi \approx 0.7$ GeV, $\Lambda_K \approx 0.9$ GeV), is able to account simultaneously for the available experimental data related to $\Gamma_p$ and $\Gamma_n$ for $^4_\Lambda$H, $^4_\Lambda$He, and $^5_\Lambda$He.Comment: 12 pages, 4 figures, 1 table, submitted for publication; v2: major revision, 18 pages, one author added, table, figures and bibliography change

Bulk-sensitive photoemission spectroscopy of A_2FeMoO_6 double perovskites (A=Sr, Ba)

Electronic structures of Sr_2FeMoO_6 (SFMO) and Ba_2FeMoO_6 (BFMO) double perovskites have been investigated using the Fe 2p->3d resonant photoemission spectroscopy (PES) and the Cooper minimum in the Mo 4d photoionization cross section. The states close to the Fermi level are found to have strongly mixed Mo-Fe t_{2g} character, suggesting that the Fe valence is far from pure 3+. The Fe 2p_{3/2} XAS spectra indicate the mixed-valent Fe^{3+}-Fe^{2+} configurations, and the larger Fe^{2+} component for BFMO than for SFMO, suggesting a kind of double exchange interaction. The valence-band PES spectra reveal good agreement with the LSDA+U calculation.Comment: 4 pages, 3 figure

Fano resonance in electronic transport through a quantum wire with a side-coupled quantum dot: X-boson treatment

The transport through a quantum wire with a side coupled quantum dot is studied. We use the X-boson treatment for the Anderson single impurity model in the limit of $U=\infty$. The conductance presents a minimum for values of T=0 in the crossover from mixed-valence to Kondo regime due to a destructive interference between the ballistic channel associated with the quantum wire and the quantum dot channel. We obtain the experimentally studied Fano behavior of the resonance. The conductance as a function of temperature exhibits a logarithmic and universal behavior, that agrees with recent experimental results.Comment: 6 pages, 10 eps figs., revtex

Leptogenesis and neutrino parameters

We calculate the baryonic asymmetry of the universe in the baryogenesis-via-leptogenesis framework, assuming first a quark-lepton symmetry and then a charged-neutral lepton symmetry. We match the results with the experimentally favoured range. In the first case all the oscillation solutions to the solar neutrino problem, except the large mixing matter solution, can lead to the allowed range, but with fine tuning of the parameters. In the second case the general result is quite similar. Some related theoretical hints are discussed.Comment: RevTex, 21 pages with 8 figure

Neutron beam test of CsI crystal for dark matter search

We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear recoils and $\gamma$'s below 10 keV. The response of CsI crystals to nuclear recoil was studied with mono-energetic neutrons produced by the $^3$H(p,n)$^3$He reaction. This was compared to the response to Compton electrons scattered by 662 keV $\gamma$-ray. Pulse shape discrimination between the response to these $\gamma$'s and nuclear recoils was studied, and quality factors were estimated. The quenching factors for nuclear recoils were derived for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM