1,631 research outputs found
Late Precontact Settlement on the Northern Seward Peninsula Coast: Results of Recent Fieldwork
Changing Arctic settlement patterns are associated with shifts in socioeconomic organization and interaction at both the inter- and intraregional levels; analysis of Arctic settlement patterns can inform research on the emergence and spread of Arctic maritime adaptations. Changes in late precontact settlement patterns in Northwest Alaska suggest significant shifts in subsistence and/or social organization, but the patterns themselves are not well understood. Prior research around Kotzebue Sound suggests three possible scenarios: (1) population decrease and dispersion from settlement centers after 550 cal bp, (2) population stability and dispersion after 550 cal bp, and (3) different settlement patterns in the northern and southern areas of Kotzebue Sound. We analyze site distribution and radiocarbon data from new research on the northern Seward Peninsula coast to address questions about local late precontact settlement patterns. Our results point to denser late precontact occupation of this region than previously understood, suggesting either population stability and dispersion after 550 cal bp or the development of differential settlement patterns around the Kotzebue Sound region. This research provides new information about late precontact settlement patterns in Northwest Alaska and contributes to the broader debate about the changing nature of Arctic maritime adaptations during the dynamic late Holocene period. Results also indicate that people in this region were well integrated into both Kotzebue Sound and more distant socioeconomic systems despite potential reduction or change in interaction spheres during the late precontact period
Large violation of Bell inequalities with low entanglement
In this paper we obtain violations of general bipartite Bell inequalities of
order with inputs, outputs and
-dimensional Hilbert spaces. Moreover, we construct explicitly, up to a
random choice of signs, all the elements involved in such violations: the
coefficients of the Bell inequalities, POVMs measurements and quantum states.
Analyzing this construction we find that, even though entanglement is necessary
to obtain violation of Bell inequalities, the Entropy of entanglement of the
underlying state is essentially irrelevant in obtaining large violation. We
also indicate why the maximally entangled state is a rather poor candidate in
producing large violations with arbitrary coefficients. However, we also show
that for Bell inequalities with positive coefficients (in particular, games)
the maximally entangled state achieves the largest violation up to a
logarithmic factor.Comment: Reference [16] added. Some typos correcte
Evaluation of the Audicor Acoustic Cardiography Device as a Diagnostic Tool in Horses with Mitral or Aortic Valve Insufficiency
Mitral and aortic valve insufficiencies have been commonly reported in horses. The objective of this study was to establish the use of acoustic cardiography (AudicorÂŽ) in horses with aortic (AI) or mitral valve insufficiency (MI). A total of 17 healthy horses, 18 horses with AI, and 28 horses with MI were prospectively included. None of the horses was in heart failure. Echocardiography and AudicorÂŽ analyses were conducted. Electromechanical activating time (EMAT), rate-corrected EMATc, left ventricular systolic time (LVST), rate-corrected LVSTc, and intensity and persistence of the third and fourth heart sound (S3, S4) were reported by AudicorÂŽ. Graphical analysis of the three-dimensional (3D) phonocardiogram served to visually detect murmurs. AudicorÂŽ snapshot variables were compared between groups using one-way ANOVA followed by Tukeyâs multiple-comparisons test. The association between AudicorÂŽ snapshot variables and the corresponding echocardiographic variables was investigated by linear regression and BlandâAltman analyses. Heart murmurs were not displayed on AudicorÂŽ phonocardiograms. No significant differences were found between AudicorÂŽ variables obtained in clinically healthy horses and horses with valvular insufficiency. The AudicorÂŽ device is unable to detect heart murmurs in horses. AudicorÂŽ variables representing cardiac function are not markedly altered, and their association with corresponding echocardiographic variables is poor in horses with valvular insufficiency that are not in heart failure
Resonance energy transfer: The unified theory revisited
Resonanceenergy transfer (RET) is the principal mechanism for the intermolecular or intramolecular redistribution of electronic energy following molecular excitation. In terms of fundamental quantum interactions, the process is properly described in terms of a virtual photon transit between the pre-excited donor and a lower energy (usually ground-state) acceptor. The detailed quantum amplitude for RET is calculated by molecular quantum electrodynamical techniques with the observable, the transfer rate, derived via application of the Fermi golden rule. In the treatment reported here, recently devised state-sequence techniques and a novel calculational protocol is applied to RET and shown to circumvent problems associated with the usual method. The second-rank tensor describing virtual photon behavior evolves from a Greenâs function solution to the Helmholtz equation, and special functions are employed to realize the coupling tensor. The method is used to derive a new result for energy transfer systems sensitive to both magnetic- and electric-dipole transitions. The ensuing result is compared to that of pure electric-dipoleâelectric-dipole coupling and is analyzed with regard to acceptable transfer separations. Systems are proposed where the electric-dipoleâmagnetic-dipole term is the leading contribution to the overall rate
Joint system quantum descriptions arising from local quantumness
Bipartite correlations generated by non-signalling physical systems that
admit a finite-dimensional local quantum description cannot exceed the quantum
limits, i.e., they can always be interpreted as distant measurements of a
bipartite quantum state. Here we consider the effect of dropping the assumption
of finite dimensionality. Remarkably, we find that the same result holds
provided that we relax the tensor structure of space-like separated
measurements to mere commutativity. We argue why an extension of this result to
tensor representations seems unlikely
ISO-3D Applications of 3-Dimensional Electromagnetic Induction by Sources in the Oceans: a MAST-3 Project. Final report of ISO-3D Working Group.
Development of the N400 for Word Learning in the First 2 Years of Life: A Systematic Review
The N400 ERP component is a direct neural index of word meaning. Studies show that the N400 component is already present in early infancy, albeit often delayed. Many researchers capitalize on this finding, using the N400 component to better understand how early language acquisition unfolds. However, variability in how researchers quantify the N400 makes it difficult to set clear predictions or build theory. Not much is known about how the N400 component develops in the first 2 years of life in terms of its latency and topographical distributions, nor do we know how task parameters affect its appearance. In the current paper we carry out a systematic review, comparing over 30 studies that report the N400 component as a proxy of semantic processing elicited in infants between 0 and 24 months old who listened to linguistic stimuli. Our main finding is that there is large heterogeneity across semantic-priming studies in reported characteristics of the N400, both with respect to latency and to distributions. With age, the onset of the N400 insignificantly decreases, while its offset slightly increases. We also examined whether the N400 appears different for recently-acquired novel words vs. existing words: both situations reveal heterogeneity across studies. Finally, we inspected whether the N400 was modulated differently with studies using a between-subject design. In infants with more proficient language skills the N400 was more often present or showed itself here with earlier latency, compared to their peers; but no consistent patterns were observed for distribution characteristics of the N400. One limitation of the current review is that we compared studies that widely differed in choice of EEG recordings, pre-processing steps and quantification of the N400, all of which could affect the characteristics of the infant N400. The field is still missing research that systematically tests development of the N400 using the same paradigm across infancy
Generation and Handling of Hard Drive Duplicates as Piece of Evidence
An important area in digital forensics is images of hard disks. The correct production of the images as well as the integrity and authenticity of each hard disk image is essential for the probative force of the image to be used at court. Integrity and authenticity are under suspicion as digital evidence is stored and used by software based systems. Modifications to digital objects are hard or even impossible to track and can occur even accidentally. Even worse, vulnerabilities occur for all current computing systems. Therefore, it is difficult to guarantee a secure environment for forensic investigations. But intended deletions of dedicated data of disk images are often required because of legal issues in many countries.
This article provides a technical framework on the protection of the probative force of hard disk images by ensuring the integrity and authenticity using state of the art technology. It combines hardware-based security, cryptographic hash functions and digital signatures to achieve a continuous protection of the image together with a reliable documentation of the status of the device that was used for image creation. The framework presented allows to detect modifications and to pinpoint the exact area of the modification to the digital evidence protecting the probative force of the evidence at a whole. In addition, it also supports the deletion of parts of images without invalidating the retained data blocks.
Keywords: digital evidence, probative force hard disk image, verifiable deletion of image data, trusted imaging softwar
Long time, large scale limit of the Wigner transform for a system of linear oscillators in one dimension
We consider the long time, large scale behavior of the Wigner transform
W_\eps(t,x,k) of the wave function corresponding to a discrete wave equation
on a 1-d integer lattice, with a weak multiplicative noise. This model has been
introduced in Basile, Bernardin, and Olla to describe a system of interacting
linear oscillators with a weak noise that conserves locally the kinetic energy
and the momentum. The kinetic limit for the Wigner transform has been shown in
Basile, Olla, and Spohn. In the present paper we prove that in the unpinned
case there exists such that for any the
weak limit of W_\eps(t/\eps^{3/2\gamma},x/\eps^{\gamma},k), as \eps\ll1,
satisfies a one dimensional fractional heat equation with . In the pinned case an analogous
result can be claimed for W_\eps(t/\eps^{2\gamma},x/\eps^{\gamma},k) but the
limit satisfies then the usual heat equation
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