209 research outputs found
Reviewing Human Language Identification
Get PDFAbstract. This article overviews human language identification (LID) experiments, especially focusing on the modification methods of stimulus, mentioning the experimental designs and languages used. A variety of signals to represent prosody have been used as stimuli in perceptual experiments: lowpass-filtered speech, laryngograph output, triangular pulse trains or sinusoidal signals, LPC-resynthesized or residual signals, white-noise driven signals, resynthesized signals preserving or degrading broad phonotactics, syllabic rhythm, or intonation, and parameterized source component of speech signal. Although all of these experiments showed that "prosody" plays a role in LID, the stimuli differ from each other in the amount of information they carry. The article discusses the acoustic natures of these signals and some theoretical backgrounds, featuring the correspondence of the source, in terms of the sourcefilter theory, to prosody, from a linguistic perspective. It also reviews LID experiments using unmodified speech, research into infants, dialectology and sociophonetic research, and research into foreign accent
N,N’-Bis(2-chloroethyl)-N-nitrosourea (BCNU)-induced Apoptosis of Neural Progenitor Cells in the Developing Fetal Rat Brain
Get PDFN,N’-bis(2-chloroethyl)-N-nitrosourea
(BCNU) is one of the major drugs used in chemotherapy against malignant
gliomas due to its effects, such as induction of bifunctional alkylation of
DNA and formation of interstrand DNA cross-linkages, and induces cortical
malformations in the fetal and neonatal rat brain. In this study, pregnant
rats were treated with 7.5 mg/kg of BCNU on gestational day 13 (GD 13), and
their fetuses were collected from 12 to 72 hours after BCNU treatment in
order to examine the timecourses of morphological and immunohistochemical
changes in neural progenitor cells in the developing brain. The number of
pyknotic cells in the telencephalon peaked at 24 h and then gradually
decreased until 72 h. The majority of these pyknotic cells were positive
for cleaved caspase-3, a key executioner of apoptosis. The pyknotic cells
showed the ultrastructural characteristics of apoptosis. The number of
p53-positive cells began to increase prior to the appearance of apoptotic
cells and p21-positive cells. The number of phosphorylated-histone
H3-positive cells (mitotic cells) decreased from 24 to 36 h. The number of
Iba1-positive cells (microglial cells) in the telencephalon increased from
12 to 48 h. These results suggest that BCNU induces p53-dependent apoptosis
and reduces proliferative activity, resulting in reduction of the weight of
the telencephalon and the thickness of the telencephalic wall in the fetal
brain. This study will help to clarify the mechanisms of BCNU-induced fetal
brain toxicity
2004～2005年度における本学部学生の英語能力測定の試み
Get PDFIn order to provide effective English language education in limited class hours, it is necessary to measure the English proficiency of the students. This paper oversees the curricula of English at this university to discuss the necessity of the proficiency measurement. Then, it analyzes the results of TOEIC and the freshman test. The paper makes suggestion on the goal setting, the necessary learning hours, and the curriculum
Liposomal Fasudil, a Rho-Kinase Inhibitor, for Prolonged Pulmonary Preferential Vasodilation in Pulmonary Arterial Hypertension
Get PDFCurrent pharmacological interventions for pulmonary arterial hypertension (PAH) require continuous infusions, multiple inhalations, or oral administration of drugs that act on various pathways involved in the pathogenesis of PAH. However, invasive methods of administration, short duration of action, and lack of pulmonary selectivity result in noncompliance and poor patient outcomes. In this study, we tested the hypothesis that encapsulation of an investigational anti-PAH molecule fasudil (HA-1077), a Rho-kinase inhibitor, into liposomal vesicles results in prolonged vasodilation in distal pulmonary arterioles. Liposomes were prepared by hydration and extrusion method and fasudil was loaded by ammonium sulfate-induced transmembrane electrochemical gradient. Liposomes were then characterized for various physicochemical properties. Optimized formulations were tested for pulmonary absorption and their pharmacological efficacy in a monocrotaline (MCT) induced rat model of PAH. The entrapment efficiency of optimized liposomal fasudil formulations was between 68.1 ± 0.8% and 73.6 ± 2.3%, and the cumulative release at 37 °C was 98–99% over a period of 5 days. Compared to intravenous (IV) fasudil, a ~ 10 fold increase in the terminal plasma half-life was observed when liposomal fasudil was administered as aerosols. The t1/2 of IV fasudil was 0.39 ± 0.12 h. and when given as liposomes via pulmonary route, the t1/2 extended to 4.71 ± 0.72 h. One h after intratracheal instillation of liposomal fasudil, mean pulmonary arterial pressure (MPAP) was reduced by 37.6 ± 5.7% and continued to decrease for about 3 h, suggesting that liposomal formulations produced pulmonary preferential vasodilation in MCT induced PAH rats. Overall, this study established the proof-of-principle that aerosolized liposomal fasudil is a feasible option for a non-invasive, controlled release and pulmonary preferential treatment of PAH
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