303 research outputs found
Chukotsk or Chukchi: Some Thoughts on the Transposition of Soviet Geographical Names
... To some cartographers and gazetteer writers the transposition of Russian geographical names into English may seem a subject well suited for an arbitrary rule of thumb; but is it? ... The reason for the current trend towards indiscriminate transliteration of Soviet geographical names is not far to seek. It is the simplest way to avoid the problems of adaptation, and at the same time enables all those who may now have a need to know the Russian version of the names to avoid learning the 32 letters of the Cyrillic alphabet - at the price of a minor distortion and some uncertainty in spelling and pronunciation. By the same token it is also the crudest manner of transposition. It literally deprives the English language of a galaxy of geographical names for a vast and increasingly important part of the earth. It is a way of dodging an issue instead of facing it. ..
The genetic structure of Nautilus pompilius populations surrounding Australia and the Philippines.
Understanding the distribution of genetic diversity in exploited species is fundamental to successful conservation. Genetic structure and the degree of gene flow among populations must be assessed to design appropriate strategies to prevent the loss of distinct populations. The cephalopod Nautilus pompilius is fished unsustainably in the Philippines for the ornamental shell trade and has limited legislative protection, despite the species' recent dramatic decline in the region. Here, we use 14 microsatellite markers to evaluate the population structure of N. pompilius around Australia and the Philippines. Despite their relative geographical proximity, Great Barrier Reef individuals are genetically isolated from Osprey Reef and Shark Reef in the Coral Sea (FST =0.312, 0.229, respectively). Conversely, despite the larger geographical distances between the Philippines and west Australian reefs, samples display a small degree of genetic structure (FST =0.015). Demographic scenarios modelled using approximate Bayesian computation analysis indicate that this limited divergence is not due to contemporary gene flow between the Philippines and west Australia. Instead, present-day genetic similarity can be explained by very limited genetic drift that has occurred due to large average effective population sizes that persisted at both locations following their separation. The lack of connectivity among populations suggests that immigrants from west Australia would not facilitate natural recolonization if Philippine populations were fished to extinction. These data help to rectify the paucity of information on the species' biology currently inhibiting their conservation classification. Understanding population structure can allow us to facilitate sustainable harvesting, thereby preserving the diversity of genetically distinct stocks. This article is protected by copyright. All rights reserved
Equivalent circuit parameter extraction of low-capacitance high-damping PTs
Existing equivalent circuit extraction techniques are inaccurate for piezoelectric transformers (PTs) with low-input capacitance or high damping. A new method is presented, offering improved accuracy in both damping resistance and resonant frequency extraction compared with state-of-the-art methods. Effectiveness is evaluated on two sample PTs, with the proposed method achieving up to 84% decrease in error compared with previous methods
Destabilization of dark states and optical spectroscopy in Zeeman-degenerate atomic systems
We present a general discussion of the techniques of destabilizing dark
states in laser-driven atoms with either a magnetic field or modulated laser
polarization. We show that the photon scattering rate is maximized at a
particular evolution rate of the dark state. We also find that the atomic
resonance curve is significantly broadened when the evolution rate is far from
this optimum value. These results are illustrated with detailed examples of
destabilizing dark states in some commonly-trapped ions and supported by
insights derived from numerical calculations and simple theoretical models.Comment: 14 pages, 10 figure
The Influence of Minimalist Footwear on Knee and Ankle Load during Depth Jumping
Plyometric training is used by athletes to promote strength and explosive power. However plyometric activities such as depth jumping are associated with a high incidence of injuries. This study examined the influence of minimalist and conventional footwear on the loads experienced by the patellofemoral joint and Achilles tendon. Patellofemoral and Achilles tendon forces were obtained from ten male participants using an eight camera 3D motion capture system and force platform data as they completed depth jumps in both footwear conditions. Differences between footwear were calculated using paired t-tests. The results show that the minimalist footwear were associated with significantly lower patellofemoral contact force/ pressure and also knee abduction moment. It is therefore recommended based on these observations that those who are susceptible to knee pain should consider minimalist footwear when performing plyometric training
Field Measurements of Terrestrial and Martian Dust Devils
Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types
Glauber Dynamics for the mean-field Potts Model
We study Glauber dynamics for the mean-field (Curie-Weiss) Potts model with
states and show that it undergoes a critical slowdown at an
inverse-temperature strictly lower than the critical
for uniqueness of the thermodynamic limit. The dynamical critical
is the spinodal point marking the onset of metastability.
We prove that when the mixing time is asymptotically
and the dynamics exhibits the cutoff phenomena, a sharp
transition in mixing, with a window of order . At the
dynamics no longer exhibits cutoff and its mixing obeys a power-law of order
. For the mixing time is exponentially large in
. Furthermore, as with , the mixing time
interpolates smoothly from subcritical to critical behavior, with the latter
reached at a scaling window of around . These results
form the first complete analysis of mixing around the critical dynamical
temperature --- including the critical power law --- for a model with a first
order phase transition.Comment: 45 pages, 5 figure
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