2,055 research outputs found
The influence of pre-experimental experience on social discrimination in rats (Rattus norvegicus)
The authors used laboratory rats (Rattus norvegicus) of known relatedness and contrasting familiarity to assess the potential effect of preexperimental social experience on subsequent social recognition. The authors used the habituation-discrimination technique, which assumes that multiple exposures to a social stimulus (e.g., soiled bedding) ensure a subject discriminates between the habituation stimulus and a novel stimulus when both are introduced simultaneously. The authors observed a strong discrimination if the subjects had different amounts of preexperimental experience with the donors of the 2 stimuli but a weak discrimination if the subjects had either equal amounts of preexperimental experience or no experience with the stimuli. Preexperimental social experience does, therefore, appear to influence decision making in subsequent social discriminations. Implications for recognition and memory research are discussed
Professional Reading
The Swordbearers: Supreme Command in the First World War, and The Theory and Practice of Wa
Organ Culture Studies of Pehmphigus Antibodies
The ultrastructural and light microscopic features of acantholysis produced in organ culture were compared with those of human pemphigus lesions. In both, an intraepidermal split was seen and typical suprabasal acantholytic cells were present. These cells contained small bundles of tonofilaments, usually located away from the cell periphery. Desmosomal plaques with inserted tonofilaments frequently remained along the periphery of acantholytic cells and along the upper portion of the periphery of basal cells. The ultrastructural similarity between in vitro and in vivo lesions provides additional evidence to suggest that organ cultures may provide a valid model for studying the dynamics of pemphigus lesion formation
Decoherence due to three-body loss and its effect on the state of a Bose-Einstein condensate
A Born-Markov master equation is used to investigate the decoherence of the
state of a macroscopically occupied mode of a cold atom trap due to three-body
loss. In the large number limit only coherent states remain pure for times
longer than the decoherence time: the time it takes for just three atoms to be
lost from the trap. For large numbers of atoms (N>10^4) the decoherence time is
found to be much faster than the phase collapse time caused by intra-trap
atomic collisions
A Multilepton signal for supersymmetric particles in Tevatron data?
The CDF and D0 collaborations have both reported unusual events in the
dilepton+jets sample with very high lepton and missing transverse energies. It
is possible, but very unlikely, that these events originate from top quark pair
production; however, they have characteristics that are better accounted for by
decays of supersymmetric quarks with mass in the region of 300 GeV: , ,
. Such a supersymmetric
origin also leads to events with large transverse missing energy and either 0,
1, 2 same-sign, or 3 isolated leptons.Comment: 11 pages, 1 figure include
Modeling direction discrimination thresholds for yaw rotations around an earth-vertical axis for arbitrary motion profiles
Understanding the dynamics of vestibular perception is important, for example, for improving the realism of motion simulation and virtual reality environments or for diagnosing patients suffering from vestibular problems. Previous research has found a dependence of direction discrimination thresholds for rotational motions on the period length (inverse frequency) of a transient (single cycle) sinusoidal acceleration stimulus. However, self-motion is seldom purely sinusoidal, and up to now, no models have been proposed that take into account non-sinusoidal stimuli for rotational motions. In this work, the influence of both the period length and the specific time course of an inertial stimulus is investigated. Thresholds for three acceleration profile shapes (triangular, sinusoidal, and trapezoidal) were measured for three period lengths (0.3, 1.4, and 6.7Â s) in ten participants. A two-alternative forced-choice discrimination task was used where participants had to judge if a yaw rotation around an earth-vertical axis was leftward or rightward. The peak velocity of the stimulus was varied, and the threshold was defined as the stimulus yielding 75Â % correct answers. In accordance with previous research, thresholds decreased with shortening period length (from ~2Â deg/s for 6.7Â s to ~0.8Â deg/s for 0.3Â s). The peak velocity was the determining factor for discrimination: Different profiles with the same period length have similar velocity thresholds. These measurements were used to fit a novel model based on a description of the firing rate of semi-circular canal neurons. In accordance with previous research, the estimates of the model parameters suggest that velocity storage does not influence perceptual thresholds
Can Asymptotic Freedom Explain the Neutrino Anomalies?
We estimate renormalization effects on ĎνĚ
/ Ďν and ăyăνĚ
in the standard four-quark model, improving on a calculation by Altarelli, Petronzio, and Parisi. Even with systematic overestimates, the Weinberg-Salam model does not give a satisfactory account of the data
Two Coupled Harmonic Oscillators on Non-commutative Plane
We investigate a system of two coupled harmonic oscillators on the
non-commutative plane \RR^2_{\theta} by requiring that the spatial coordinates
do not commute. We show that the system can be diagonalized by a suitable
transformation, i.e. a rotation with a mixing angle \alpha. The obtained
eigenstates as well as the eigenvalues depend on the non-commutativity
parameter \theta. Focusing on the ground state wave function before the
transformation, we calculate the density matrix \rho_0(\theta) and find that
its traces {\rm Tr}(\rho_{0}(\theta)) and {\rm Tr}(\rho_0^2(\theta)) are not
affected by the non-commutativity. Evaluating the Wigner function on
\RR^2_{\theta} confirms this. The uncertainty relation is explicitly determined
and found to depend on \theta. For small values of \theta, the relation is
shifted by a \theta^2 term, which can be interpreted as a quantum correction.
The calculated entropy does not change with respect to the normal case. We
consider the limits \alpha=1 and \alpha={\pi\over 2}. In first case, by
identifying \theta to the squared magnetic length, one can recover basic
features of the Hall system.Comment: 15 pages, 1 figur
Phenomenology as a resource for patients
Patient support tools have drawn on a variety of disciplines, including psychotherapy, social psychology, and social care. One discipline that has not so far been used to support patients is philosophy. This paper proposes that a particular philosophical approach, phenomenology, could prove useful for patients, giving them tools to reflect on and expand their understanding of their illness. I present a framework for a resource that could help patients to philosophically examine their illness, its impact on their life, and its meaning. I explain the need for such a resource, provide philosophical grounding for it, and outline the epistemic and existential gains philosophy offers. Illness often begins as an intrusion on one's life but with time becomes a way of being. I argue that this transition impacts on core human features such as the experience of space and time, human abilities, and adaptability. It therefore requires philosophical analysis and response. The paper uses ideas from Husserl and Merleau-Ponty to present such a response in the form of a phenomenological toolkit for patients. The toolkit includes viewing illness as a form of phenomenological reduction, thematizing illness, and examining illness as altering the ill person's being in the world. I suggest that this toolkit could be offered to patients as a workshop, using phenomenological concepts, texts, and film clips to reflect on illness. I conclude by arguing that examining illness as a limit case of embodied existence deepens our understanding of phenomenology.Š The Author 2012. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved
Maximal variance reduction for stochastic propagators with applications to the static quark spectrum
We study a new method -- maximal variance reduction -- for reducing the
variance of stochastic estimators for quark propagators. We find that while
this method is comparable to usual iterative inversion for light-light mesons,
a considerable improvement is achieved for systems containing at least one
infinitely heavy quark. Such systems are needed for heavy quark effective
theory. As an illustration of the effectiveness of the method we present
results for the masses of the ground state and excited states of
mesons and baryons. We compare these results with the experimental
spectra involving quarks.Comment: 31 pages with 7 postscript file
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