151 research outputs found
Predictability in an unpredictable artificial cultural market
In social, economic and cultural situations in which the decisions of
individuals are influenced directly by the decisions of others, there appears
to be an inherently high level of ex ante unpredictability. In cultural markets
such as films, songs and books, well-informed experts routinely make
predictions which turn out to be incorrect.
We examine the extent to which the existence of social influence may,
somewhat paradoxically, increase the extent to which winners can be identified
at a very early stage in the process. Once the process of choice has begun,
only a very small number of decisions may be necessary to give a reasonable
prospect of being able to identify the eventual winner.
We illustrate this by an analysis of the music download experiments of
Salganik et.al. (2006). We derive a rule for early identification of the
eventual winner. Although not perfect, it gives considerable practical success.
We validate the rule by applying it to similar data not used in the process of
constructing the rule
Thermal Field Theory and Generalized Light Front Coordinates
The dependence of thermal field theory on the surface of quantization and on
the velocity of the heat bath is investigated by working in general coordinates
that are arbitrary linear combinations of the Minkowski coordinates. In the
general coordinates the metric tensor is non-diagonal. The
Kubo, Martin, Schwinger condition requires periodicity in thermal correlation
functions when the temporal variable changes by an amount
. Light front quantization fails since
, however various related quantizations are possible.Comment: 10 page
Realising the Olympic dream: vision, support and challenge
The sporting arena is replete with examples and anecdotes of great inspirational coaches that have led teams to success, often in the face of adversity and against seemingly better opponents. The role of the coach in developing and motivating athletes has also been the focus of much research in sport psychology (e.g., Challaduria 1990; Smith & Smoll, 2007). Despite the ease with which one readily accepts that coaches can be inspirational, the sport coaching literature is somewhat devoid of research on inspirational coaches and the effects of such coaches on athletic success. The purpose of the current paper is to theoretically delineate the inspirational effects of coaches in sport. Given the relative paucity of inspiration-related research in sport we draw upon contemporary theories of leadership from organisational and military psychology (e.g., transformational and charismatic leadership theories). We propose a sport-specific model of leadership that centres around the vision, support, and challenge meta-cognitive model developed by Arthur and Hardy in military contexts. The model posits that �great� coaches inspire their athletes by: (a) creating an inspirational vision of the future; (b) providing the necessary support to achieve the vision; and (c) providing the challenge to achieve the vision. The underlying proposition is that the vision provides meaning and direction for followers� effort. That is, the vision serves as the beacon around which all the sweat, pain and sacrifice involved in achieving success at the highest level in sport is directed. At the heart of this model is the notion that athletes can achieve their dreams provided they are inspired to do so; this is because all other things being equal the person who is motivated to practice longer and train harder will ultimately be the best. The current paper will delineate the coach�s role in inspiring the athlete to train harder and longer
Structure of the Quark Propagator at High Temperature
In the high temperature, chirally invariant phase of QCD, the quark
propagator is shown to have two sets of poles with different dispersion
relations. A reflection property in momentum space relates all derivatives at
zero-momentum of the particle and hole energies, the particle and hole damping
rates, and the particle and hole residues. No use is made of perturbation
theory.Comment: 8 pages, Latex twocolum
Alarming signs and symptoms in febrile children in primary care: An observational cohort study in The Netherlands
__Abstract__
Context: Febrile children in primary care have a low risk for serious infection. Although several alarming signs and symptoms are proposed to have predictive value for serious infections, most are based on research in secondary care. The frequency of alarming signs/symptoms has not been established in primary care; however, in this setting differences in occurrence may influence their predictive value for serious infections. Objective: To determine the frequency of alarming signs/symptoms in febrile children in primary care. Design: Observational cohort study. Clinical information was registered in a semi-structured way and manually recoded. Setting: General practitioners' out-of-hours service. Subjects: Face-to-face patient contacts concerning children (aged ≤16 years) with fever were eligible for inclusion. Main outcome measures: Frequency of 18 alarming signs and symptoms as reported in the literature. Results: A total of 10,476 patient contacts were included. The frequency of alarming signs/symptoms ranged from n = 1 (ABC instability; 40°C as reported by the parents; 12.9%) to 8,647 contacts (parental concern; 82.5%). Conclusion: Although the prevalence of specific alarming signs/symptoms is low in primary care, ≥50% of children have one or more alarming signs/symptoms. There is a need to determine the predictive value of alarming signs/symptoms not only for serious infections in primary care, but as well for increased risk of a complicated course of the illness
The electron thermal propagator at p>>T: An entire function of p_{0}
The retarded electron propagator S_{R}(p_{0},p) at high momentum p>>T was
shown by Blaizot and Iancu to be an entire function of complex p_{0}. In this
paper a specific form for S_{R}(p_{0},p) is obtained and checked by showing
that its temporal Fourier transform S_{R}(t, p) has the correct behavior at
large t. Potential infrared and collinear divergences from the emission of soft
photons do not occur.Comment: 8 page
Residual feed intake and relationships with performance of Nellore cattle selected for post weaning weight
The Majorana Neutrinoless Double-Beta Decay Experiment
The proposed Majorana double-beta decay experiment is based on an array of
segmented intrinsic Ge detectors with a total mass of 500 kg of Ge isotopically
enriched to 86% in 76Ge. A discussion is given of background reduction by:
material selection, detector segmentation, pulse shape analysis, and
electro-formation of copper parts and granularity. Predictions of the
experimental sensitivity are given. For an experimental running time of 10
years over the construction and operation of Majorana, a half-life sensitivity
of ~4x10^27 y (neutrinoless) is predicted. This corresponds to an effective
Majorana mass of the electron neutrino of ~0.03-0.04 eV, according to recent
QRPA and RQRPA matrix element calculations.Comment: 10 pages, 7 figure
Características corporais associadas com a adaptação ao calor em bovinos naturalizados brasileiros
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