bluuebunny/crossref_metadata_2025 huggingface dataset:
Practical Rhumb Line Calculations on the Spheroid
Authors: Bennett G. G.
Published: October 2009

About ten years ago this author wrote the software for a suite of navigation programmes which was resident in a small hand-held computer. In the course of this work it became apparent that the standard text books of navigation were perpetuating a flawed method of calculating rhumb lines on the Earth considered as an oblate spheroid. On further investigation it became apparent that these incorrect methods were being used in programming a number of calculator/computers and satellite navigation receivers. Although the discrepancies were not large, it was disquieting to compare the results of the same rhumb line calculations from a number of such devices and find variations of some miles when the output was given, and therefore purported to be accurate, to a tenth of a mile in distance and/or a tenth of a minute of arc in position. The problem has been highlighted in the past and the references at the end of this show that a number of methods have been proposed for the amelioration of this problem. This paper summarizes formulae that the author recommends should be used for accurate solutions. Most of these may be found in standard geodetic text books, such as, but also provided are new formulae and schemes of solution which are suitable for use with computers or tables. The latter also take into account situations when a near-indeterminate solution may arise. Some examples are provided in an appendix which demonstrate the methods. The data for these problems do not refer to actual terrestrial situations but have been selected for illustrative purposes only. Practising ships' navigators will find the methods described in detail in this paper to be directly applicable to their work and also they should find ready acceptance because they are similar to current practice. In none of the references cited at the end of this paper has the practical task of calculating, using either a computer or tabular techniques, been addressed.
Developing International Specifications for Future Nautical Charts – Possibilities and Pitfalls
Authors: Kerr Adam J.
Published: October 2009

This paper and the following six papers were presented at the NAV95 Conference held in London, November 199j. The full proceedings, under the title containing 30 papers, can be obtained from the Director (£25 to Members, £35 to Non-Members).
Route Guidance Systems: Getting it Right from the Driver's Perspective
Authors: Burnett Gary , Joyner Sue
Published: October 2009

This paper presents a brief overview of current human factors research into route guidance systems. A short description of different interface styles is given and a review of two road-based studies of three existing route guidance systems is provided. A general discussion then highlights a range of issues of relevance to driver-system interfaces, drawing on results both from the studies carried out, and other research. Specific aspects addressed include the content and means of presenting route guidance information, and the potential effect of interface design on driver visual behaviour and performance.
Interference to GPS in the Marine Environment
Authors: Ward N. , Johannessen R.
Published: October 2009

This paper was presented at a Workshop organized by the Institute in London in October 1995 on the subject of GPS Interference – Is it a Problem? Copies of the Workshop Notes can be obtained from the Director (£50 to Members, £75 Non-members, £10 to students).
The Great Ellipse on the Surface of the Spheroid
Authors: Williams Roy
Published: October 2009

On any surface which fulfils the required continuity conditions, the shortest path between two points on the surface is along the are of a geodesic curve. On the surface of a sphere the geodesic curves are the great circles and the shortest path between any two points on this surface is along the arc of a great circle, but on the surface of an ellipsoid of revolution, the geodesic curves are not so easily defined except that the equator of this ellipsoid is a circle and its meridians are ellipses.
The Development of Inland VTS in the Netherlands
Authors: Stuurman Pieter M.
Published: October 2009

This paper, and the two following papers, were included in the VTS-96 Symposium held in Rotterdam in April 1996. They are reproduced by kind permission of the Symposium Organizing Committee.

In the Netherlands, inland waterways occupy an important position in the transport of goods to and from the hinterland. To guarantee safety at dangerous junctions, VTS-centres have been introduced since 1952. Some years ago an extra dimension was added to some of these VTScentres, namely the promotion of the optimal use of a limited waterway, to guarantee a smooth traffic flow. This is certainly necessary for the river Waal, which can be considered as the aorta to the German hinterland.

Automatic data exchange between all inland VTS-centres and the German information centres along the Rhine contributes to a great extent to the operation of the VTS-centres. In case of an accident, appropriate measures can be taken immediately, saving human life and respecting the environment.
Light Signals for Indicating Course Alterations: A report for the Mercantile Marine Institute of Japan
Authors: Iijima Y. , Satoh S.
Published: October 2009

This report summarizes a study of signals for indicating course alterations conducted by the Course Signal Committee of The Mercantile Marine Institute of Japan (President Captain Inazo Ara) as part of the 1995 project entitled ‘Research on Improving Course Signals etc’ sponsored by The Japan Foundation for Shipbuilding Advancement.
The Collision Avoidance Regulations as a Regulator of International Navigation Rights: Underlying Principles and their Adequacy for the Twenty-first Century
Authors: Plant Glen
Published: October 2009

The high seas freedom of navigation, and the lesser rights of transit, archipelagic sea lane and innocent passage applicable in straits used for international navigation, archipelagic sea lanes and the territorial sea respectively, have been said to embrace two notions: ‘one is the right to make progress over the surface of the sea, the other is the duty to make progress only in an orderly way, as to speed, steering, lights and so on – the manner of operation of the right’.
On The Selection of Discrete Grid Systems for On-Board Micro-based Weather Routeing
Authors: Motte R. H. , Calvert S.
Published: October 2009

The purpose of this paper is to show the effect of incorporating various discrete grid systems in a micro-based, ship weather-routeing system, which employs Bellman's dynamic programming algorithm, and either a cost-objective or time-objective performance measure. A simple ship speed and power function is utilized, in the cost computation. The calculation of the least-cost/least-time route is briefly described, but it is the derivation of the discrete grids and their influence on the route decisions that forms the paper's emphasis. The measure of cost within this paper is necessarily notional.
Air Navigation Systems: Chapter 3. The Beginnings of Directional Radio Techniques for Air Navigation, 1910–1940
Authors: Kendal Brian
Published: October 2009

This paper is the third chapter of a series on Air Navigation Systems during the period from the early oceanic flights and the inception of commercial aviation to the introduction of INS in civil aircraft. Some initial comments on the paper are included in the Forum section of this issue of theJournal. Further comments would be welcomed by the author and the editor.
The Weather of the 1979 Fastnet Yacht Race
Authors: Watts Alan
Published: October 2009

It is over 10 years since this ill-fated Fastnet Race claimed the lives of fifteen yachtsmen and the total loss of five yachts. A total of twenty-four crews abandoned their yachts and in all, 136 people were saved by being winched into helicopters and taken on board merchant and naval ships as well as other yachts. Some eighteen yachts needed the assistance of lifeboats because they had lost their rudders.
Computer-drawn Charts for EROPS Flights
Authors: Lawrence W. P.
Published: October 2009

The advent of EROPS extended-range flights by twin-engined aircraft demonstrated the need for a computer program to draw charts to assist the flight planner in operational decision-making. An EROPS Planning Aid program (EROPA) was written by the author to run on a desktop computer. This article briefly describes the EROPS rules, and how EROPA is used. Then the subject of chart-drawing using a desktop computer is discussed, and other related applications are considered.
The Electronic Chart: Present Status and Future Problems
Authors: Kerr A. J. , Eaton R. M. , Anderson N. M.
Published: October 2009

1. INTRODUCTION. Interest in the use of video displays for nautical chart presentation has increased rapidly during the last two years. Eaton et al. at the Second International Hydrographic Technical Conference provided a list of ten different systems already in production. Oshima speaking at a Workshop on the subject in Canada, early in 1985, mentioned that some 4000 Japanese fishing boats and 150 merchant vessels now carry electronic charts of varying degrees of complexity.
Indication of Effective Speed and Deceleration to Vessels in Port Approaches
Authors: Ratcliffe S. , Lyon P. R.
Published: October 2009

1. INTRODUCTION. The controlled deceleration of a ship in the final approaches to the berthing area is of crucial importance to ensure that the ship is stopped in time and can be manoeuvred to the berth by assistant tugs. Shipborne instrumentation cannot be relied upon entirely to assist the ship handler in this aspect because, with very few exceptions, it does not give sufficiently accurate information at very low speeds and minimum underkeel clearances. Traditionally of course, it is part of the ship handler's skill to judge the ship speed and deceleration by eye and it is important that this skill is finely developed to arrive correctly at the manoeuvring area. It is however the case that the judgment of very low speeds becomes increasingly difficult with the larger ships, yet it is with such ships that this judgment is the most critical.
The Last Transatlantic
Authors: Richey Michael
Published: October 2009

On 15 July 1988 in position 39° 08′ N., 58° 43′ W., some 470 miles south-east of Halifax, Nova Scotia, Jester was abandoned and her skipper taken off by the M/V Nilam, a 60000-ton bulk carrier bound for New York.

The boat was engaged in the single-handed transatlantic race from Plymouth to Newport, Rhode Island. The race, which started on 5 June, was Jester's eighth and her fourteenth transatlantic passage. The incident, a knockdown, occurred some 40 days out.
ARPA Accuracy Testing
Authors: Lenart Andrzej S.
Published: October 2009

In this paper, methods and formulas for testing ARPA (Automatic Radar Plotting Aid) equipment according to IMO requirements are developed. The International Maritime Organization (IMO) and International Electrotechnical Commission (IEC) requirements for tracking accuracy are also discussed.
A Brief History of Ancient Chinese Sailing Directions
Authors: Guang-Qi Sun
Published: October 2009

abstract

This paper, based on documentary records, attempts a brief, systematic investigation of the main characteristics of ancient Chinese sailing directions in terms of content and form as well as development. The evolution of Chinese sailing directions can be divided historically into the following periods and categories:

1. Non-written records.

2. Primitive written forms.

3. From non-quantitative description to quantitative description.

4. Quantitative description with charts,

5 . Charts aided by written descriptions.

In the course of his examination of these categories, the author analyses the most important sailing directions in Chinese history, and concludes that, Zheng He Hang Hai Tu (Zheng He's Nautical Charts) compiled in the first half of the fifteenth century, are not only the first illustrative sailing directions which do not rely on written directions but appear to be the first nautical chart collection for ocean-going sailing in history.

Finally, the author points out that, although western sailing directions have contributed greatly to navigational science and technology, the Chinese contribution to the development of sailing directions, deserves greater recognition.
Very‐low‐frequency earthquakes indicate a transpressional stress regime in the Nankai accretionary prism
Authors: Ito Yoshihiro , Asano Youichi , Obara Kazushige
Published: October 2009

We investigated the stress field within the Nankai accretionary prism of southwestern Japan, where very‐low‐frequency (VLF) earthquakes occur associated with thrust faulting. A northwest–southeast azimuth of the maximum horizontal principal stress previously estimated from borehole breakouts in wells drilled in the region by deep‐sea drilling vessel Chikyu suggests trench‐normal shortening, although strike‐slip and normal faulting are also possible within a thrust‐dominated tectonic environment. We estimated stress orientations and stress ratios by using stress tensor inversion to derive moment tensor solutions for VLF earthquakes in three regions along the Nankai Trough: off Kumano, off Muroto, and Hyuga‐nada. The stress orientations we obtained indicate that the regions off Kumano and off Muroto are within a transpressional stress regime with trench‐normal shortening, whereas the Hyuga‐nada region on the westernmost edge of the Nankai accretionary prism is in a reverse‐faulting regime.
Annual push moraines as climate proxy
Authors: Beedle Matthew J. , Menounos Brian , Luckman Brian H. , Wheate Roger
Published: October 2009

We reconstruct the terminus position of a mountain glacier in British Columbia, Canada from annual push moraines formed between 1959 and 2007. Our reconstruction represents the longest, annually‐resolved record of length change for a North American glacier. Comparison of annual recession with climate records indicates that glacier recession is controlled by air temperatures during the ablation season and accumulation season precipitation during the previous decade. Analysis among records of glacier frontal variation and mass balance in western North America similarly reveals an immediate terminus reaction to summer and net balance and a delayed reaction to winter and net balance. Other mountain ranges may contain long series of push moraines that could be exploited as climate proxies, and to improve understanding of glacier response to climate.
Aseismic slow slip on an inland active fault triggered by a nearby shallow event, the 2008 Iwate‐Miyagi Nairiku earthquake (Mw6.8)
Authors: Iinuma T. , Ohzono M. , Ohta Y. , Miura S. , Kasahara M. , Takahashi H. , Sagiya T. , Matsushima T. , Nakao S. , Ueki S. , Tachibana K. , Sato T. , Tsushima H. , Takatsuka K. , Yamaguchi T. , Ichiyanagi M. , Takada M. , Ozawa K. , Fukuda M. , Asahi Y. , Nakamoto M. , Yamashita Y. , Umino N.
Published: October 2009

Using GPS observations, we have detected an aseismic slip event on the intraplate Dedana Fault that was triggered by the Iwate‐Miyagi Nairiku earthquake (Mw6.8, 13 Jun 2008 UTC) on a nearby but separate fault. The observations cannot be satisfactorily explained in terms of either viscoelastic relaxation or poroelastic rebound, and we cannot explain the observed displacement time series without presuming that aseismic slip occurred on the Dedana Fault. This slip was likely triggered by the mainshock stress change. The detection of future such aseismic slip events on intraplate faults is likely to require denser geodetic networks than are currently in operation, but is important for fully characterizing the seismic hazard associated with intraplate earthquakes.
Vortex‐like plasma flow structures observed by Cluster at the boundary of the outer radiation belt and ring current: A link between the inner and outer magnetosphere
Authors: Zong Q.‐G. , Wang Y. F. , Yang B. , Zhang H. , Tian A. M. , Dunlop M. , Fritz T. A. , Kistler L. M. , Korth A. , Daly P. W. , Pedersen A.
Published: October 2009

Two vortex‐like plasma flow structures have been observed at the outer radiation belt and/or the ring current region on 11 April 2002, from 0415 to 0635 UT, when the Cluster fleet entered (in the Southern Hemisphere) and exited (in the Northern Hemisphere) the boundary layer of the inner magnetosphere near 2130 MLT. On 11 April 2002 during the period of interest, the solar wind speed was high, and the geomagnetic activity was moderate. These two vortices have opposite rotation directions and are characterized by bipolar signatures in the flow Vx components with peak‐to‐peak amplitudes of about 40 km/s. The inflection points of the plasma flow coincide precisely with the local maxima of the duskward core flow Vy (30 km/s) which exceed the surrounding flow by 3–4 times in magnitude for both vortices. A pair of bidirectional current sheets and bipolar electric fields (Ey) are found to be closely associated with these vortices. Whereas magnetic field disturbances are observed only in Bx and By components, the magnetic magnitude stays almost unchanged. Vortices observed both inbound and outbound at the boundary of the radiation belt at nearly the same location (L shell and latitude), suggesting they may last for more than 140 min. The scale sizes of the two vortices are about 810 km and 1138 km, respectively. Interestingly, it is found that Earth's ionospheric singly charged oxygen are precipitating in the vortex dynamic process, having energies less than 1 keV and having a strong field‐aligned pitch angle distribution. These plasma flow vortices are suggested to be formed at the interface between the enhanced ionospheric outflow stream from the polar ionosphere and a sudden braking and/or azimuthal deflection of bursty bulk flows generated by the tail reconnection. These observed flow vortices provide a link among the inner magnetosphere, the tail plasma sheet, and the Earth's ionosphere by coupling magnetic shear stresses and plasma flow momentum.
Relationship of the BOLD Signal with VEP for Ultrashort Duration Visual Stimuli (0.1 to 5 ms) in Humans
Authors: Yeşilyurt Barış , Whittingstall Kevin , Uğurbil Kâmil , Logothetis Nikos K , Uludağ Kâmil
Published: October 2009

There is currently a great interest to combine electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to study brain function. Earlier studies have shown different EEG components to correlate well with the fMRI signal arguing for a complex relationship between both measurements. In this study, using separate EEG and fMRI measurements, we show that (1) 0.1 ms visual stimulation evokes detectable hemodynamic and visual-evoked potential (VEP) responses, (2) the negative VEP deflection at ∼80 ms (N2) co-varies with stimulus duration/intensity such as with blood oxygenation level-dependent (BOLD) response; the positive deflection at ∼120 ms (P2) does not, and (3) although the N2 VEP–BOLD relationship is approximately linear, deviation is evident at the limit of zero N2 VEP. The latter finding argues that, although EEG and fMRI measurements can co-vary, they reflect partially independent processes in the brain tissue. Finally, it is shown that the stimulus-induced impulse response function (IRF) at 0.1 ms and the intrinsic IRF during rest have different temporal dynamics, possibly due to predominance of neuromodulation during rest as compared with neurotransmission during stimulation. These results extend earlier findings regarding VEP–BOLD coupling and highlight the component- and context-dependency of the relationship between evoked potentials and hemodynamic responses.
Performance of the ALOGPS 2.1 program for octanol-water partition coefficient prediction with organic chemicals on the Canadian Domestic Substances List
Authors: Rayne Sierra , Forest Kaya
Published: October 2009

The KOWWIN and ALOGPS octanol-water partition coefficient (K~ow~) estimation software programs were compared for their capacity to accurately predict log K~ow~ values of 1596 organic compounds on the publicly available Domestic Substances List (DSL) from Environment Canada for which experimental data is available. KOWWIN contained a significantly lower number and magnitude of prediction errors compared to ALOGPS, particularly at experimental log K~ow~ values <2. Substantial predictive differences were observed between the two programs for 9093 compounds not having experimental K~ow~ data on the Canadian DSL. Predictive differences of up to 40 log K~ow~ units were found between KOWWIN and ALOGPS, and in some cases, the discrepancies were sufficiently large that strongly opposing hydrophobicity classifications were obtained.
Role of phosphoinositides in STIM1 dynamics and store-operated calcium entry
Authors: Walsh Ciara M. , Chvanov Michael , Haynes Lee P. , Petersen Ole H. , Tepikin Alexei V. , Burgoyne Robert D.
Published: October 2009

Ca2+ entry through store-operated Ca2+ channels involves the interaction at ER–PM (endoplasmic reticulum–plasma membrane) junctions of STIM (stromal interaction molecule) and Orai. STIM proteins are sensors of the luminal ER Ca2+ concentration and, following depletion of ER Ca2+, they oligomerize and translocate to ER–PM junctions where they form STIM puncta. Direct binding to Orai proteins activates their Ca2+ channel function. It has been suggested that an additional interaction of the C-terminal polybasic domain of STIM1 with PM phosphoinositides could contribute to STIM1 puncta formation prior to binding to Orai. In the present study, we investigated the role of phosphoinositides in the formation of STIM1 puncta and SOCE (store-operated Ca2+ entry) in response to store depletion. Treatment of HeLa cells with inhibitors of PI3K (phosphatidylinositol 3-kinase) and PI4K (phosphatidylinositol 4-kinase) (wortmannin and LY294002) partially inhibited formation of STIM1 puncta. Additional rapid depletion of PtdIns(4,5)P2 resulted in more substantial inhibition of the translocation of STIM1–EYFP (enhanced yellow fluorescent protein) into puncta. The inhibition was extensive at a concentration of LY294002 (50 μM) that should primarily inhibit PI3K, consistent with a major role for PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in puncta formation. Depletion of phosphoinositides also inhibited SOCE based on measurement of the rise in intracellular Ca2+ concentration after store depletion. Overexpression of Orai1 resulted in a recovery of translocation of STMI1 into puncta following phosphoinositide depletion and, under these conditions, SOCE was increased to above control levels. These observations support the idea that phosphoinositides are not essential but contribute to STIM1 accumulation at ER–PM junctions with a second translocation mechanism involving direct STIM1–Orai interactions.
Deep-level spectroscopy studies of confinement levels in SiGe quantum wells
Authors: Antonova Irina V. , Neustroev Efim P. , Smagulova Svetlana A. , Kagan Miron S. , Alekseev Pavel S. , Ray Samit K. , Sustersic Nathan , Kolodzey James
Published: October 2009

The recharging of quantum confinement levels in SiGe quantum wells (QWs) was studied by charge deep-level transient spectroscopy (Q-DLTS) for Si/SiGe/Si structures with different Ge contents in the SiGe layer. The set of levels were observed as the different slopes in the Arrhenius plots for the same Q-DLTS peak in different temperature ranges. These activation energies were compared to the energies of quantum confinement levels in the QW calculated in frames of six-band model taking into account spin-orbit interaction and attributed to a thermally activated tunneling of holes from the SiGe QW.
A gradient-directed Monte Carlo method for global optimization in a discrete space: Application to protein sequence design and folding
Authors: Hu Xiangqian , Beratan David N. , Yang Weitao
Published: October 2009

We apply the gradient-directed Monte Carlo (GDMC) method to select optimal members of a discrete space, the space of chemically viable proteins described by a model Hamiltonian. In contrast to conventional Monte Carlo approaches, our GDMC method uses local property gradients with respect to chemical variables that have discrete values in the actual systems, e.g., residue types in a protein sequence. The local property gradients are obtained from the interpolation of discrete property values, following the linear combination of atomic potentials scheme developed recently [M. Wang et al., J. Am. Chem. Soc. 128, 3228 (2006)]. The local property derivative information directs the search toward the global minima while the Metropolis criterion incorporated in the method overcomes barriers between local minima. Using the simple HP lattice model, we apply the GDMC method to protein sequence design and folding. The GDMC algorithm proves to be particularly efficient, suggesting that this strategy can be extended to other discrete optimization problems in addition to inverse molecular design.
Improved charge transport through Si based multiple quantum wells with substoichiometric SiOx barrier layers
Authors: Berghoff Birger , Suckow Stephan , Rölver Robert , Spangenberg Bernd , Kurz Heinrich , Sologubenko Alla , Mayer Joachim
Published: October 2009

The vertical charge transport through Si/SiOx multiple quantum wells (QWs) is investigated. Upon thermal annealing, segregation of excess Si from the SiOx layers leads to the formation of highly conductive pathways between Si grains from adjacent QWs separated by ultrathin silicon oxide barriers with barrier heights of 0.53–0.65 eV. Compared to stoichiometric Si/SiO2 layer stacks, conductivity is increased by up to ten orders of magnitude, which opens the way to an efficient charge carrier extraction in photovoltaic systems with distinct quantum confinement.
Phonon dynamics of Zn(Mg,Cd)O alloy nanostructures and their phase segregation
Authors: Ghosh Manoranjan , Dilawar Nita , Bandyopadhyay A. K. , Raychaudhuri A. K.
Published: October 2009

In this paper we report phonon dynamics in chemically synthesized Zn1−xMgxO (0≤x≤0.07) and Zn1−yCdyO (0≤y≤0.03) alloy nanostructures of sizes ∼10 nm using nonresonant Raman and Fourier transformed infrared spectroscopy. Substitution by Mg makes the unit cell compact while Cd substitution leads to unit cell expansion. On alloying, both A1 (LO) and E1 (LO) mode of wurtzite ZnO show blueshift for Zn1−xMgxO and redshift for Zn1−yCdyO alloy nanostructures due to mass defect and volume change induced by the impurity atoms. Significant shift has been observed in E1 (LO) mode for Zn1−xMgxO (73 cm−1 for x=0.07) and Zn1−yCdyO (17 cm−1 for y=0.03) nanostructures. The variation in Zn(Mg,Cd)–O bond length determined from the blue- (red-) shift of IR bands on alloying with Mg (Cd) is consistent with their respective ionic sizes and the structural changes predicted by x-ray diffraction study. However, on progressive alloying one can detect phase segregation (due to presence of interstitial Mg and Cd ions) in the alloy nanostructures for relatively higher Mg and Cd concentrations. This is confirmed by the gradual absence of the characteristic IR and Raman bands of wurtzite ZnO near 400–600 cm−1 as well as by x-ray and TEM studies.
Ferromagnetic resonance of individual magnetic double layer microwires
Authors: Au Yat-Yin , Ingvarsson Snorri
Published: October 2009

Ferromagnetic resonance measurements were done on individual magnetic double layer microwires. Two magnetic precession modes, namely, the acoustic (in-phase) and the optical (out-of-phase) modes, were clearly revealed. Their frequency dependencies on applied magnetic field were measured, fitted with simple theoretical predictions, and explained in the context of interlayer magnetostatic dipolar coupling. The effectiveness of exciting the two precession modes by injected microwave electric current was studied against different layer dimensions. The results are highly relevant to fast switching of small magnetic devices relying on Amperian field generated by in-plane current inside the devices.
Quantum size effects on spin-tunneling time in a magnetic resonant tunneling diode
Authors: Saffarzadeh Alireza , Daqiq Reza
Published: October 2009

We study theoretically the quantum size effects of a magnetic resonant tunneling diode (RTD) with a (Zn,Mn)Se dilute magnetic semiconductor layer on the spin-tunneling time and the spin polarization of the electrons. The results show that the spin-tunneling times may oscillate and a great difference between the tunneling time of the electrons with opposite spin directions can be obtained depending on the system parameters. We also study the effect of structural asymmetry which is related to the difference in the thickness of the nonmagnetic layers. It is found that the structural asymmetry can greatly affect the traversal time and the spin polarization of the electrons tunneling through the magnetic RTD. The results indicate that, by choosing suitable values for the thickness of the layers, one can design a high-speed and perfect spin-filter diode.
Electrode conformation-induced negative differential resistance and rectifying performance in a molecular device
Authors: Deng X. Q. , Zhou J. C. , Zhang Z. H. , Zhang H. , Qiu M. , Tang G. P.
Published: October 2009

Carrying out theoretical calculations using the nonequilibrium Green’s function method combined with the density functional theory, the transport properties of a carbon wire connected to two Au electrodes are investigated. The results show that the negative differential resistance and rectifying performance can be observed apparently when a pure carbon chain is connected to two asymmetric Au electrodes. The main origin of the negative differential resistance behavior is a suppression of the highest occupied molecular orbital resonance at certain bias voltage. Also shown is that it is possible to make the negative differential resistance disappear and rectifying performance be weakened only by adding side groups to a wire.
Room-temperature grain growth in sputtered nanoscale Pd thin films: Dynamic scaling behaviour on SiO2
Authors: Ruffino F. , Irrera A. , De Bastiani R. , Grimaldi M. G.
Published: October 2009

Dynamic scaling behavior has been observed during the room-temperature growth of sputtered Pd films on SiO2 using the scanning electron microscopy technique. By the analyses of the dependence of the Pd grain size and surface density on the film thickness, the dynamical growth exponent z=4.2±0.3 was obtained, suggesting a conservative growth process. The analysis of the fraction of surface covered by Pd as a function of film thickness (up to a maximum of 8.5×1016atoms∕cm2, corresponding to 125nm) allowed us to identify two different growth regimes in the investigated range: films thinner than 1.8×1016atoms∕cm2 (26.5nm) that grow as an outside-cluster system and thicker film that exhibit an islandlike growth.
Remediation of Cr(VI) by biogenic magnetic nanoparticles: An x-ray magnetic circular dichroism study
Authors: Telling N. D. , Coker V. S. , Cutting R. S. , van der Laan G. , Pearce C. I. , Pattrick R. A. D. , Arenholz E. , Lloyd J. R.
Published: October 2009

Biologically synthesized magnetite (Fe3O4) nanoparticles are studied using x-ray absorption and x-ray magnetic circular dichroism following exposure to hexavalent Cr solution. By examining their magnetic state, Cr cations are shown to exist in trivalent form on octahedral sites within the magnetite spinel surface. The possibility of reducing toxic Cr(VI) into a stable, nontoxic form, such as a Cr3+-spinel layer, makes biogenic magnetite nanoparticles an attractive candidate for Cr remediation.
Making the random phase approximation to electronic correlation accurate
Authors: Grüneis Andreas , Marsman Martijn , Harl Judith , Schimka Laurids , Kresse Georg
Published: October 2009

We show that the inclusion of second-order screened exchange to the random phase approximation allows for an accurate description of electronic correlation in atoms and solids clearly surpassing the random phase approximation, but not yet approaching chemical accuracy. From a fundamental point of view, the method is self-correlation free for one-electron systems. From a practical point of view, the approach yields correlation energies for atoms, as well as for the jellium electron gas within a few kcal/mol of exact values, atomization energies within typically 2–3 kcal/mol of experiment, and excellent lattice constants for ionic and covalently bonded solids (0.2% error). The computational complexity is only O(N5), comparable to canonical second-order Møller–Plesset perturbation theory, which should allow for routine calculations on many systems.
Generation and manipulation of droplets in an optoelectrofluidic device integrated with microfluidic channels
Authors: Lee Do-Hyun , Hwang Hyundoo , Park Je-Kyun
Published: October 2009

This letter describes an optoelectrofluidic platform integrated with microfluidic channels for continuous generation and programmable manipulation of water-in-oil droplet emulsions. A microchannel was integrated into a film-based optoelectrofluidic device by selective perforation of poly(dimethylsiloxane) layer for simultaneously performing microfluidic generation and optoelectrofluidic manipulation of droplets in a single device. By using this device, we could continuously generate, interactively transport, and merge multiple droplets using optically induced virtual electrodes.
Comparison of Alzheimer Aβ(1–40) and Aβ(1–42) amyloid fibrils reveals similar protofilament structures
Authors: Schmidt Matthias , Sachse Carsten , Richter Walter , Xu Chen , Fändrich Marcus , Grigorieff Nikolaus
Published: October 2009

We performed mass-per-length (MPL) measurements and electron cryomicroscopy (cryo-EM) with 3D reconstruction on an Aβ(1–42) amyloid fibril morphology formed under physiological pH conditions. The data show that the examined Aβ(1–42) fibril morphology has only one protofilament, although two protofilaments were observed with a previously studied Aβ(1–40) fibril. The latter fibril was resolved at 8 Å resolution showing pairs of β-sheets at the cores of the two protofilaments making up a fibril. Detailed comparison of the Aβ(1–42) and Aβ(1–40) fibril structures reveals that they share an axial twofold symmetry and a similar protofilament structure. Furthermore, the MPL data indicate that the protofilaments of the examined Aβ(1–40) and Aβ(1–42) fibrils have the same number of Aβ molecules per cross-β repeat. Based on this data and the previously studied Aβ(1–40) fibril structure, we describe a model for the arrangement of peptides within the Aβ(1–42) fibril.
Destruction of spirochete
Borrelia burgdorferi
round-body propagules (RBs) by the antibiotic Tigecycline
Authors: Brorson Øystein , Brorson Sverre-Henning , Scythes John , MacAllister James , Wier Andrew , Margulis Lynn
Published: October 2009

Persistence of tissue spirochetes of
Borrelia burgdorferi
as helices and round bodies (RBs) explains many erythema-Lyme disease symptoms. Spirochete RBs (reproductive propagules also called coccoid bodies, globular bodies, spherical bodies, granules, cysts, L-forms, sphaeroplasts, or vesicles) are induced by environmental conditions unfavorable for growth. Viable, they grow, move and reversibly convert into motile helices. Reversible pleiomorphy was recorded in at least six spirochete genera (>12 species). Penicillin solution is one unfavorable condition that induces RBs. This antibiotic that inhibits bacterial cell wall synthesis cures neither the second “Great Imitator” (Lyme borreliosis) nor the first: syphilis. Molecular-microscopic techniques, in principle, can detect in animals (insects, ticks, and mammals, including patients) helices and RBs of live spirochetes. Genome sequences of
B. burgdorferi
and
Treponema pallidum
spirochetes show absence of >75% of genes in comparison with their free-living relatives. Irreversible integration of spirochetes at behavioral, metabolic, gene product and genetic levels into animal tissue has been documented. Irreversible integration of spirochetes may severely impair immunological response such that they persist undetected in tissue. We report in vitro inhibition and destruction of
B. burgdorferi
(helices, RBs = “cysts”) by the antibiotic Tigecycline (TG; Wyeth), a glycylcycline protein-synthesis inhibitor (of both 30S and 70S ribosome subunits). Studies of the pleiomorphic life history stages in response to TG of both
B. burgdorferi
and
Treponema pallidum
in vivo and in vitro are strongly encouraged.
Psychology through international congresses: Differences between regions, countries, and congresses
Authors: Adair John G. , Unik Lauren M. , Huynh Cam‐Loi
Published: October 2009

A published database of presentations from the seven most recent International Congresses of Applied Psychology (ICAPs) was compared to a similar but unpublished database (Adair, Anguas‐Plata, Unik, & Radons, 2009) on the International Congresses of Psychology (ICPs) for the years 1996–2004. Analyses revealed phenomena characteristic of attendance at both international congresses: Participation rates spike dramatically for host countries; less dramatic regional surges in participation occur when the congress is held in a neighbouring country. Psychologists from 117 different countries participated in the seven recent congresses (ICAP and ICP) from 1994 to 2006. Overall ICP was double the size of ICAP, and represented a larger set of countries at each of its congresses. Regardless of location, most participants at both congresses came from the same 11 economically advantaged and seven majority‐world countries. Congress presentations are dispersed across a much larger number of countries than are journal publications. The USA, for example, had modest 14.4% (ICAP) and 11.6% (ICP) presentation rates, much smaller than its majority share of publications (Adair, 2009). By contrast, the USA had the greater share of invited addresses at both ICAP (33.7%) and ICP (28.9%) congresses. Nonetheless, the majority‐world countries contributing to both ICAP and ICP are clearly indicative of where the discipline is gaining strength and importance to international psychology. The emergence of Iran as a new leading national contributor to the two most recent international congresses, and the rise in the proportion of presentations by majority‐world psychologists at ICAPs from only about one in five to more than one of every three presentations in recent congresses are findings consistent with Zakaria's (2008) analysis of changes taking place in the world. Within international congresses, certainly, the “rise of the rest” is changing the face of international psychology.
WHY ARE IRISH ATTITUDES TO IMMIGRANTS AMONG THE MOST LIBERAL IN EUROPE?
Authors: Turner Tom
Published: October 2009

There has been a dramatic inflow of immigrants into Ireland in recent years. Yet recent European Social Surveys indicate that Irish attitudes towards immigrants are among the most liberal in Europe. We test the association between a number of economic and cultural measures and attitudes to immigrants at the aggregate national level. Although Ireland fits the expected association and in the predicted direction the most notable feature of our results is the lack of a clear pattern between these measures and attitudes to immigrants across the European countries in the sample.
SeSaMoNet: an RFID-based economically viable navigation system for the visually impaired
Authors: Biader Ceipidor U. , Medaglia C.M. , Serbanati A. , Azzalin G. , Barboni M. , Rizzo F. , Sironi M.
Published: October 2009

In this article, the authors present secure and safe mobility network (SeSaMoNet), a navigation and environment description system for users with visual impairments. The system is designed with attention to usability and accessibility features and for its great scalability. The spread of mobile technology such as handheld devices and related software, personal digital assistants and smartphones, wireless communication, text-to-speech, databases and finally radio frequency identification made it possible for the authors to build a portable, easy to use orientation and navigation aid that still has a great development margin. A double version, Symbian and Windows Mobile, allows quite every type of user equipment to be supported. The system aims to provide a non-intrusive and accessible way to expand the experiences of people with visual impairments and provide them with useful information about the environment beyond the tactile probing of the closest surroundings. This article expands previous work, detailing the usability and accessibility issues the authors faced and the new features introduced in the last period.
Bub3p Facilitates Spindle Checkpoint Silencing in Fission Yeast
Authors: Vanoosthuyse Vincent , Meadows John C. , van der Sar Sjaak J.A. , Millar Jonathan B.A. , Hardwick Kevin G.
Published: October 2009

Although critical for spindle checkpoint signaling, the role kinetochores play in anaphase promoting complex (APC) inhibition remains unclear. Here we show that spindle checkpoint proteins are severely depleted from unattached kinetochores in fission yeast cells lacking Bub3p. Surprisingly, a robust mitotic arrest is maintained in the majority of bub3Δ cells, yet they die, suggesting that Bub3p is essential for successful checkpoint recovery. During recovery, two defects are observed: (1) cells mis-segregate chromosomes and (2) anaphase onset is significantly delayed. We show that Bub3p is required to activate the APC upon inhibition of Aurora kinase activity in checkpoint-arrested cells, suggesting that Bub3p is required for efficient checkpoint silencing downstream of Aurora kinase. Together, these results suggest that spindle checkpoint signals can be amplified in the nucleoplasm, yet kinetochore localization of spindle checkpoint components is required for proper recovery from a spindle checkpoint-dependent arrest.
Anesthesia Prevents Auditory Perceptual Learning
Authors: Aberg Kristoffer C. , Albrecht Eric , Tartaglia Elisa M. , Farron Alain , Soom Patrice , Herzog Michael H.
Published: October 2009

Background

An auditory perceptual learning paradigm was used to investigate whether implicit memories are formed during general anesthesia.

Methods

Eighty-seven patients who had an American Society of Anesthesiologists physical status of I-III and were scheduled to undergo an elective surgery with general anesthesia were randomly assigned to one of two groups. One group received auditory stimulation during surgery, whereas the other did not. The auditory stimulation consisted of pure tones presented via headphones. The Bispectral Index level was maintained between 40 and 50 during surgery. To assess learning, patients performed an auditory frequency discrimination task after surgery, and comparisons were made between the groups. General anesthesia was induced with thiopental and maintained with a mixture of fentanyl and sevoflurane.

Results

There was no difference in the amount of learning between the two groups (mean +/- SD improvement: stimulated patients 9.2 +/- 11.3 Hz, controls 9.4 +/- 14.1 Hz). There was also no difference in initial thresholds (mean +/- SD initial thresholds: stimulated patients 31.1 +/- 33.4 Hz, controls 28.4 +/- 34.2 Hz). These results suggest that perceptual learning was not induced during anesthesia. No correlation between the bispectral index and the initial level of performance was found (Pearson r = -0.09, P = 0.59).

Conclusion

Perceptual learning was not induced by repetitive auditory stimulation during anesthesia. This result may indicate that perceptual learning requires top-down processing, which is suppressed by the anesthetic.
Prevention of Atelectasis in Morbidly Obese Patients during General Anesthesia and Paralysis
Authors: Reinius Henrik , Jonsson Lennart , Gustafsson Sven , Sundbom Magnus , Duvernoy Olov , Pelosi Paolo , Hedenstierna Göran , Fredén Filip
Published: October 2009

Background

Morbidly obese patients show impaired pulmonary function during anesthesia and paralysis, partly due to formation of atelectasis. This study analyzed the effect of general anesthesia and three different ventilatory strategies to reduce the amount of atelectasis and improve respiratory function.

Methods

Thirty patients (body mass index 45 +/- 4 kg/m) scheduled for gastric bypass surgery were prospectively randomized into three groups: (1) positive end-expiratory pressure of 10 cm H2O (PEEP), (2) a recruitment maneuver with 55 cm H2O for 10 s followed by zero end-expiratory pressure, (3) a recruitment maneuver followed by PEEP. Transverse lung computerized tomography scans and blood gas analysis were recorded: awake, 5 min after induction of anesthesia and paralysis at zero end-expiratory pressure, and 5 min and 20 min after intervention. In addition, spiral computerized tomography scans were performed at two occasions in 23 of the patients.

Results

After induction of anesthesia, atelectasis increased from 1 +/- 0.5% to 11 +/- 6% of total lung volume (P < 0.0001). End-expiratory lung volume decreased from 1,387 +/- 581 ml to 697 +/- 157 ml (P = 0.0014). A recruitment maneuver + PEEP reduced atelectasis to 3 +/- 4% (P = 0.0002), increased end-expiratory lung volume and increased Pao2/Fio2 from 266 +/- 70 mmHg to 412 +/- 99 mmHg (P < 0.0001). PEEP alone did not reduce the amount of atelectasis or improve oxygenation. A recruitment maneuver + zero end-expiratory pressure had a transient positive effect on respiratory function. All values are presented as mean +/- SD.

Conclusions

A recruitment maneuver followed by PEEP reduced atelectasis and improved oxygenation in morbidly obese patients, whereas PEEP or a recruitment maneuver alone did not.
Patterns of Communication during the Preanesthesia Visit
Authors: Zollo Raymond A. , Lurie Stephen J. , Epstein Ronald , Ward Denham S.
Published: October 2009

Background

Effective communication in the preanesthesia clinic is important in patient-centered care. Although patient-physician communication has been studied by recordings in other contexts, there have been no observational studies of the communication patterns of anesthesiologists and patients during the preanesthesia interview.

Methods

Two experienced standardized patients were trained to portray the same clinical situation by using different coping styles (maximizing information or "monitoring" vs. minimizing information or "blunting"). Interviews of standardized patients by anesthesiologists took place in the preanesthesia clinic and recorded with the knowledge of the subjects. Audio recordings were analyzed, and the visit was separated into nine components. Discussion of the risks/informed consent process was examined, looking for discussion of common morbidities. The standardized patients completed a survey on the patient-centeredness of the interview.

Results

Twenty-seven subjects participated in this study. Interviews with the monitor required more time: 17.4 min (confidence interval [CI] 15.2-19.6, n = 24) versus 14.5 min (CI 13.1-16.0, n = 25), P < 0.05. Most interview time was spent in obtaining the history; 2.4 min (CI 1.8-3.1) was spent discussing risks with the monitor, and only 1.6 min (CI 1.2-2.0) was spent with the blunter (P < 0.05). Neither the monitor nor the blunter scored the interview highly for involving the patient in determining the goals of the anesthetic and recovery.

Conclusions

Direct recording of interactions with standardized patients is a feasible method of studying the communication skills of anesthesiologists. For this study, the anesthesia providers were able to modify their approach depending on patient type, but the monitor received more information.