CAN STRUCTURAL CHANGE EXPLAIN THE DECREASE IN RETURNS TO TECHNICAL ANALYSIS?

Practioners Abstract: Returns to managed futures funds and Commodity Trading Advisors (CTAs) have decreased dramatically during the last several years. Since these funds overwhelmingly use technical analysis, this research examines futures prices to determine if there is evidence of a structural change in futures price movements that could explain the reduction in fund returns. Bootstrap tests are used to test significance of a change in statistics related to daily returns, close-to-open changes, breakaway gaps, and serial correlation. Results indicate that several statistics have changed across a broad range of commodities indicating futures price fluctuations have changed. The lower price volatility, decreased price reaction time, and decreased serial correlation may partly explain the lower returns from technical analysis.Marketing,

High-energy kink in high-temperature superconductors

In conventional metals, electron-phonon coupling, or the phonon-mediated interaction between electrons, has long been known to be the pairing interaction responsible for the superconductivity. The strength of this interaction essentially determines the superconducting transition temperature TC. One manifestation of electron-phonon coupling is a mass renormalization of the electronic dispersion at the energy scale associated with the phonons. This renormalization is directly observable in photoemission experiments. In contrast, there remains little consensus on the pairing mechanism in cuprate high temperature superconductors. The recent observation of similar renormalization effects in cuprates has raised the hope that the mechanism of high temperature superconductivity may finally be resolved. The focus has been on the low energy renormalization and associated "kink" in the dispersion at around 50 meV. However at that energy scale, there are multiple candidates including phonon branches, structure in the spin-fluctuation spectrum, and the superconducting gap itself, making the unique identification of the excitation responsible for the kink difficult. Here we show that the low-energy renormalization at ~50 meV is only a small component of the total renormalization, the majority of which occurs at an order of magnitude higher energy (~350 meV). This high energy kink poses a new challenge for the physics of the cuprates. Its role in superconductivity and relation to the low-energy kink remains to be determined.Comment: 13 pages, 4 figure

Quantum Melting of the Charge Density Wave State in 1T-TiSe2

We report a Raman scattering study of low-temperature, pressure-induced melting of the CDW phase of 1T-TiSe2. Our Raman scattering measurements reveal that the collapse of the CDW state occurs in three stages: (i) For P<5 kbar, the pressure dependence of the CDW amplitude mode energies and intensities are indicative of a ``crystalline'' CDW regime; (ii) for 5 < P < 25 kbar, there is a decrease in the CDW amplitude mode energies and intensities with increasing pressure that suggests a regime in which the CDW softens, and may decouple from the lattice; and (iii) for P>25 kbar, the absence of amplitude modes reveals a melted CDW regime.Comment: 5 pages, 4 figure

Gestures and words in naming: Evidence from cross-linguistic and cross-cultural comparison

We report on an analysis of spontaneous gesture production in 2-year-old children who come from three countries (Italy, UK and Australia) and whom speak two languages (Italian and English), in an attempt to tease apart the influence of language and culture when comparing children from different cultural and linguistic environments. Eighty-seven monolingual children aged 24-30 months completed an experimental task measuring their comprehension and production of nouns and predicates. The Italian children scored significantly higher than the other groups on all lexical measures. With regards to gestures, British children produced significantly fewer pointing and speech combinations compared to the Italian and Australian children, who did not differ from each other. In contrast, Italian children produced significantly more representational gestures than the two other groups. We conclude that spoken language development is primarily influenced by the input language over gesture production, whereas the combination of cultural and language environments affects gesture productions

Borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis in deer ticks, Delaware.

During the 1998 hunting season in Delaware, 1,480 ticks were collected from 252 white- tailed deer; 98% were Ixodes scapularis, a significant increase from the 85% reported in 1988. Ticks were tested for Borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis. Infection rates remained stable in New Castle and Kent counties, but increased from <1% to 8% in sussex county

Case report on trial: Do you, Doctor, swear to tell the truth, the whole truth and nothing but the truth?

We are in the era of "evidence based medicine" in which our knowledge is stratified from top to bottom in a hierarchy of evidence. Many in the medical and dental communities highly value randomized clinical trials as the gold standard of care and undervalue clinical reports. The aim of this editorial is to emphasize the benefits of case reports in dental and oral medicine, and encourage those of us who write and read them