Unsupervised extraction of recurring words from infant-directed speech

To date, most computational models of infant word segmentation have worked from phonemic or phonetic input, or have used toy datasets. In this paper, we present an algorithm for word extraction that works directly from naturalistic acoustic input: infant-directed speech from the CHILDES corpus. The algorithm identifies recurring acoustic patterns that are candidates for identification as words or phrases, and then clusters together the most similar patterns. The recurring patterns are found in a single pass through the corpus using an incremental method, where only a small number of utterances are considered at once. Despite this limitation, we show that the algorithm is able to extract a number of recurring words, including some that infants learn earliest, such as Mommy and the child’s name. We also introduce a novel information-theoretic evaluation measure

Predictors of Failure from Primary Therapy for Giardiasis in San Diego: A Single Institution Retrospective Review.

This study aimed to determine the presence of giardiasis among HIV patients in San Diego, the rate of failure of metronidazole treatment, and factors associated with treatment failure. We used a 7 year retrospective single-center case series of HIV-infected individuals with giardiasis at University of California San Diego Medical Center. Data were analyzed for the changes in the hematological, biochemical, and immunologic results at pre- and at-diagnosis levels. We also compared the changes at the diagnosis level among patients who were treated successfully and those who experienced treatment failure as defined by retreatment with a second course of antibiotics. In 29 Giardia lamblia-infected HIV patients, following diagnosis of G. lamblia, there was a non-significant decrement in cluster of differentiation 4 (CD4), but a statistically significant increase in the number of white blood cell (WBC). Other indices did not differ between pre- and at-diagnosis levels. Twenty patients (69%) were treated with a single course of metronidazole or tinidazole and seven patients (24.1%) were treated with more than one course of metronidazole. These seven patients had statistically significant higher hemoglobin at the time of diagnosis, but further studies are required to confirm if this is a consistent finding and if this can predict failure from primary therapy

Thermal-infrared spectral observations of geologic materials in emission

The thermal-infrared spectra of geologic materials in emission were studied using the prototype Thermal Emission Spectrometer (TES). A variety of of processes and surface modifications that may influence or alter the spectra of primary rock materials were studied. It was confirmed that thermal emission spectra contain the same absorption features as those observed in transmission and reflection spectra. It was confirmed that the TES instrument can be used to obtain relevant spectra for analysis of rock and mineral composition

PRODUCTIVITY GROWTH IN THE CARIBBEAN: A MEASURE OF KEY COMPONENTS

Productivity growth is decomposed into two components: technical change and efficiency change. This assesses their relative importance to the international competitiveness of the agricultural sectors of selected Caribbean countries. A nonparametric programming method is employed to compute Malmquist multifactor productivity indexes, which contrasts the innovation of races of these countries. Keywords: Multifactor productivity, Malmquist indexes, Caribbean agriculture, Relative efficiency, Technical efficiencyMultifactor productivity, Malmquist indexes, Caribbean agriculture, Relative efficiency, Technical efficiency, Productivity Analysis, Research Methods/ Statistical Methods,

Quasi-normal modes of rotating relativistic stars - neutral modes for realistic equations of state

We compute zero-frequency (neutral) quasi-normal f-modes of fully relativistic and rapidly rotating neutron stars, using several realistic equations of state (EOSs) for neutron star matter. The zero-frequency modes signal the onset of the gravitational radiation-driven instability. We find that the l=m=2 (bar) f-mode is unstable for stars with gravitational mass as low as 1.0 - 1.2 M_\odot, depending on the EOS. For 1.4 M_\odot neutron stars, the bar mode becomes unstable at 83 % - 93 % of the maximum allowed rotation rate. For a wide range of EOSs, the bar mode becomes unstable at a ratio of rotational to gravitational energies T/W \sim 0.07-0.09 for 1.4 M_\odot stars and T/W \sim 0.06 for maximum mass stars. This is to be contrasted with the Newtonian value of T/W \sim 0.14. We construct the following empirical formula for the critical value of T/W for the bar mode, (T/W)_2 = 0.115 - 0.048 M / M_{max}^{sph}, which is insensitive to the EOS to within 4 - 6 %. This formula yields an estimate for the neutral mode sequence of the bar mode as a function only of the star's mass, M, given the maximum allowed mass, M_{max}^{sph}, of a nonrotating neutron star. The recent discovery of the fast millisecond pulsar in the supernova remnant N157B, supports the suggestion that a fraction of proto-neutron stars are born in a supernova collapse with very large initial angular momentum. Thus, in a fraction of newly born neutron stars the instability is a promising source of continuous gravitational waves. It could also play a major role in the rotational evolution (through the emission of angular momentum) of merged binary neutron stars, if their post-merger angular momentum exceeds the maximum allowed to form a Kerr black hole.Comment: 12 pages, 5 figures, submitted to Ap

The end of HIV: Still a very long way to go, but progress continues.

In an Editorial accompanying PLOS Medicine's Special Issue on Advances in Prevention, Treatment and Cure of HIV/AIDS, Guest Editors Steven Deeks, Sharon Lewin, and Linda-Gail Bekker discuss priorities in the field and the content of the issue