29,547 research outputs found
Letter to Sound Rules for Accented Lexicon Compression
This paper presents trainable methods for generating letter to sound rules
from a given lexicon for use in pronouncing out-of-vocabulary words and as a
method for lexicon compression.
As the relationship between a string of letters and a string of phonemes
representing its pronunciation for many languages is not trivial, we discuss
two alignment procedures, one fully automatic and one hand-seeded which produce
reasonable alignments of letters to phones.
Top Down Induction Tree models are trained on the aligned entries. We show
how combined phoneme/stress prediction is better than separate prediction
processes, and still better when including in the model the last phonemes
transcribed and part of speech information. For the lexicons we have tested,
our models have a word accuracy (including stress) of 78% for OALD, 62% for CMU
and 94% for BRULEX. The extremely high scores on the training sets allow
substantial size reductions (more than 1/20).
WWW site: http://tcts.fpms.ac.be/synthesis/mbrdicoComment: 4 pages 1 figur
Structure, bonding and morphology of hydrothermally synthesised xonotlite
The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies
CHARACTERIZATION AND TARGETING OF THE ENDOCANNABINOID SYSTEM IN TRAUMATIC BRAIN INJURY
Traumatic Brain Injuries (TBI) are considered one of the leading causes of death and disability worldwide. One emerging area of TBI research is the involvement of the endocannabinoid system (ECS) in response to brain injury. The ECS is modulated by exogenous cannabinoids such as ∆9-tetrahydrocannabinol (THC) found in Cannabis sativa. THC is a partial agonist of both cannabinoid receptors CB1R and CB2R. CB1R activation is associated with neuroprotective effects and contributes to analgesia and anxiolytic effects, whereas CB2R activation reduces inflammation. Therefore, the treatment of rats subjected to TBI with THC post-injury may restore motor function and improve behavioral profiles of injured rats. In order to assess behavioral and physiological changes associated with TBI following a closed head impact injury in a rat model, two experiments were performed. Rats were subjected to a closed-head injury impact equivalent to a mild/moderate TBI, or sham injury, and subsequently treated with THC or vehicle treatment. In the first experiment, 9 rats of both sexes were randomly assigned to: 1) SHAM TBI + Vehicle; 2) SHAM TBI + 1 mg/kg THC; 3) TBI + Vehicle; or 4) TBI + 1 mg/kg THC. Rats were subjected to a number of behavioural measures to assess drug effect, anxiety, working memory, and locomotor function following injury. Rats were assessed prior to TBI to establish a baseline, and on the above measures for 7 days following TBI. In the second experiment, 3 rats of both sexes were randomly assigned to 1) TBI + Vehicle or 2) TBI + 10mg/kg THC and tested for locomotor performance only. According to the data collected, TBI significant decreased male but not female locomotor recovery on the rotarod. Additionally, 1 mg/kg THC administration 1 h post-TBI significantly decreased male Sham-TBI, but not female locomotor activity. In the second experiment, visible differences in locomotor recovery were seen between TBI-VEH vs. TBI+THC 10 mg/kg on day 1-4 following TBI and drug administration, but according to the data collected, 10 mg/kg THC administration 1 h post-TBI did not significantly impact locomotor recovery post injury. THC or TBI did not significantly change other behavioural measures collected. These data demonstrate the importance of exploring the therapeutic potential of cannabinoids such as THC following TBI, which could contribute to reducing the longevity of lasting post-injury symptomology
X-ray polarimetry with an active-matrix pixel proportional counter
We report the first results from an X-ray polarimeter with a micropattern gas
proportional counter using an amorphous silicon active matrix readout. With
100% polarized X-rays at 4.5 keV, we obtain a modulation factor of 0.33 +/-
0.03, confirming previous reports of the high polarization sensitivity of a
finely segmented pixel proportional counter. The detector described here has a
geometry suitable for the focal plane of an astronomical X-ray telescope.
Amorphous silicon readout technology will enable additional extensions and
improvements.Comment: 4 pages, 4 figures, 1 tabl
Macroscopic coherence effects in a mesoscopic system: Weak localization of thin silver films in an undergraduate lab
We present an undergraduate lab that investigates weak localization in thin
silver films. The films prepared in our lab have thickness, , between 60-200
\AA, a mesoscopic length scale. At low temperatures, the inelastic dephasing
length for electrons, , exceeds the thickness of the film (), and the films are then quasi-2D in nature. In this situation, theory
predicts specific corrections to the Drude conductivity due to coherent
interference between conducting electrons' wavefunctions, a macroscopically
observable effect known as weak localization. This correction can be destroyed
with the application of a magnetic field, and the resulting magnetoresistance
curve provides information about electron transport in the film. This lab is
suitable for Junior or Senior level students in an advanced undergraduate lab
course.Comment: 16 pages, 9 figures. Replaces earlier version of paper rejected by
Am. J. Phys. because of too much content on vacuum systems. New version deals
with the undergraduate experiment on weak localization onl
Parity Effect in a Small Superconducting Particle
Matveev and Larkin calculated the parity effect on the ground state energy of
a small superconducting particle in the regimes where the mean level spacing is
either large or small compared to the bulk gap. We perform a numerical
calculation which extends their results into the intermediate regime, where the
level spacing is of the same order as the bulk gap.Comment: 6 LaTeX pages, including 2 EPS figures; corrected reference and
spellin
Health and education provider collaboration to deliver adolescent sexual and reproductive health in Sri Lanka
The complex nature of adolescent sexual and reproductive health (ASRH) determinants demands a multidisciplinary and intersectoral approach. Collaborative approaches are central to the delivery of quality health care and services but the focus is often health sector specific. Few research studies have explored the views and experiences of health workers and teachers and examined how ASRH services and information are provided by professionals across the education and health sector. Sri Lanka has made considerable progress towards addressing the Millennium Development Goals (MDG), however, there are still gaps reflected in adolescent health, social indicators, and the delivery of services. Enhancing the collective efforts of teachers and health professionals may help to improve the quality and use of services and ASRH knowledge. This study aimed to identify the experiences, needs, knowledge, attitudes and practices of primary healthcare and education professionals and the strategies that best support them to deliver sexual and reproductive health information, education, counseling and clinical services to Sri Lankan adolescents. Qualitative and survey data were gathered from 65 nurses, midwives, public health inspectors, medical officers, teachers, counselors and principals in the district of Kalutara. Knowledge, attitudes and service gaps were identified in relation to contraception and policy guiding practice. Participants highlighted concerns with confidence, roles and training that were said to affect student access to appropriate health services. ASRH Collaborative practices were noted across the sectors and strategies suggested for improvement. Findings suggest that inter-professional educa-tion and training may provide opportunities to enhance collaboration supported and guided by appropriate policy, supervision and job descriptions (i.e. roles and responsibilities)
Progression and assessment in foreign languages at Key Stage 2
The teaching of primary languages has been increasing steadily, in response to the future entitlement for all Key Stage 2 (KS2) pupils aged 7-11 to learn a foreign language by 2010. However, there remain concerns about progression both within KS2 and through to secondary school and about how learners' progress is assessed. This paper presents findings on the issues of progression and assessment taken from case studies which formed part of a project funded by the then Department for Education and Skills (DfES), now the Department for Children, Schools and Families (DCSF). This project set out to evaluate 19 local authority (LA) Pathfinders in England that were piloting the introduction of foreign language learning at KS2 between 2003 and 2005. Findings revealed that there was inconsistency between schools, even within each LA Pathfinder, in the use of schemes of work and that assessment was generally underdeveloped in the majority of the Pathfinders. In order to set these findings in context, this paper examines the issues of progression and assessment in foreign language learning in England. Finally, it investigates the challenges English primary schools face in terms of progression and assessment in the light of the new entitlement and discusses implications for the future. Managing progression, both within KS2 and through to secondary school at KS3 (ages 11-14), is one of the key factors in determining the overall success of starting languages in primary school
Ground State Properties of One Dimensional S=1/2 Heisenberg Model with Dimerization and Quadrumerization
The one dimensional S=1/2 Heisenberg model with dimerization and
quadrumerization is studied by means of the numerical exact diagonalization of
finite size systems. Using the phenomenological renormalization group and
finite size scaling law, the ground state phase diagram is obtained in the
isotropic case. It exhibits a variety of the ground states which contains the
S=1 Haldane state, S=1 dimer state and S=1/2 dimer state as limiting cases. The
gap exponent is also calculated which coincides with the value for the
dimerization transition of the isotropic Heisenberg chain. In the XY limit, the
phase diagram is obtained analytically and the comparison is made with the
isotropic case.Comment: 4 pages, 7 figure
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Designing information for families caring for people with dementia
A health communication project, to develop information to support families caring for people with dementia, is described. Close collaboration of designers with carers – ‘experts by experience’ – and clinicians and other professionals – ‘experts by training’ – was used. Carer consultation led to a printed (rather than digital) handbook. An iterative process of carer and clinician consultation and design shaped the material form of the handbook. Carers’ needs for different kinds of information were met by a modular approach, and tailored module design. Evaluation following distribution of the handbook suggested it improved carers’ understanding of dementia significantly compared to the information from diverse sources supplied previously. It did not, however, influence people’s confidence in their ability to care, which appeared to be supported better through carer education courses. The specific contribution of information design and its potential for delivering return on investment are discussed
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