2,236 research outputs found
Forward Attention in Sequence-to-sequence Acoustic Modelling for Speech Synthesis
This paper proposes a forward attention method for the sequenceto- sequence
acoustic modeling of speech synthesis. This method is motivated by the nature
of the monotonic alignment from phone sequences to acoustic sequences. Only the
alignment paths that satisfy the monotonic condition are taken into
consideration at each decoder timestep. The modified attention probabilities at
each timestep are computed recursively using a forward algorithm. A transition
agent for forward attention is further proposed, which helps the attention
mechanism to make decisions whether to move forward or stay at each decoder
timestep. Experimental results show that the proposed forward attention method
achieves faster convergence speed and higher stability than the baseline
attention method. Besides, the method of forward attention with transition
agent can also help improve the naturalness of synthetic speech and control the
speed of synthetic speech effectively.Comment: 5 pages, 3 figures, 2 tables. Published in IEEE International
Conference on Acoustics, Speech and Signal Processing 2018 (ICASSP2018
Impacts of gravitational-wave standard siren observation of the Einstein Telescope on weighing neutrinos in cosmology
We investigate the impacts of the gravitational-wave (GW) standard siren
observation of the Einstein Telescope (ET) on constraining the total neutrino
mass. We simulate 1000 GW events that would be observed by the ET in its
10-year observation by taking the standard CDM cosmology as a fiducial
model. We combine the simulated GW data with other cosmological observations
including cosmic microwave background (CMB), baryon acoustic oscillations
(BAO), and type Ia supernovae (SN). We consider three mass hierarchy cases for
the neutrino mass, i.e., normal hierarchy (NH), inverted hierarchy (IH), and
degenerate hierarchy (DH). Using Planck+BAO+SN, we obtain eV
for the NH case, eV for the IH case, and
eV for the DH case. After considering the GW data, i.e., using
Planck+BAO+SN+GW, the constraint results become eV for the
NH case, eV for the IH case, and eV for
the DH case. We find that the GW data can help reduce the upper limits of by 13.7%, 7.5%, and 10.3% for the NH, IH, and DH cases, respectively. In
addition, we find that the GW data can also help break the degeneracies between
and other parameters. We show that the GW data of the ET could
greatly improve the constraint accuracies of cosmological parameters.Comment: 8 pages, 4 figure
Monitoring thermal pollution in rivers downstream of dams with Landsat ETM+ thermal infrared images
Dams play a significant role in altering the spatial pattern of temperature in rivers and contribute to thermal pollution, which greatly affects the river aquatic ecosystems. Understanding the temporal and spatial variation of thermal pollution caused by dams is important to prevent or mitigate its harmful effect. Assessments based on in-situ measurements are often limited in practice because of the inaccessibility of water temperature records and the scarcity of gauges along rivers. By contrast, thermal infrared remote sensing provides an alternative approach to monitor thermal pollution downstream of dams in large rivers, because it can cover a large area and observe the same zone repeatedly. In this study, Landsat Enhanced Thematic Mapper Plus (ETM+) thermal infrared imagery were applied to assess the thermal pollution caused by two dams, the Geheyan Dam and the Gaobazhou Dam, located on the Qingjiang River, a tributary of the Yangtze River downstream of the Three Gorges Reservoir in Central China. The spatial and temporal characteristics of thermal pollution were analyzed with water temperatures estimated from 54 cloud-free Landsat ETM+ scenes acquired in the period from 2000 to 2014. The results show that water temperatures downstream of both dams are much cooler than those upstream of both dams in summer, and the water temperature remains stable along the river in winter, showing evident characteristic of the thermal pollution caused by dams. The area affected by the Geheyan Dam reaches beyond 20 km along the downstream river, and that affected by the Gaobazhou Dam extends beyond the point where the Qingjiang River enters the Yangtze River. Considering the long time series and global coverage of Landsat ETM+ imagery, the proposed technique in the current study provides a promising method for globally monitoring the thermal pollution caused by dams in large rivers
Consumer perception towards internet health information resources
This research aims to examine consumer perception towards Internet health information resources. Data was collected among 205 respondents by using convenience sampling and was analyzed using descriptive statistics. Descriptively, there was more females' respondent than males' respondent in this survey where all of them are recently undertaking degree courses. The result shows perceived ease of use and perceived usefulness was the main factor that motivates students in using internet health information resources
Mechanistic insight into 3-methylmercaptopropionate metabolism and kinetical regulation of demethylation pathway in marine dimethylsulfoniopropionate-catabolizing bacteria
The vast majority of oceanic dimethylsulfoniopropionate (DMSP) is thought to be catabolized by bacteria via the DMSP demethylation pathway. This pathway contains four enzymes termed DmdA, DmdB, DmdC and DmdD/AcuH, which together catabolise DMSP to acetylaldehyde and methanethiol as carbon and sulfur sources, respectively. Whilst molecular mechanisms for DmdA and DmdD have been proposed, little is known of the catalytic mechanisms of DmdB and DmdC, which are central to this pathway. Here we undertake physiological, structural and biochemical analyses to elucidate the catalytic mechanisms of DmdB and DmdC. DmdB, a 3-methylmercaptopropionate (MMPA)-coenzyme A (CoA) ligase, undergoes two sequential conformational changes to catalyze the ligation of MMPA and CoA. DmdC, a MMPA-CoA dehydrogenase, catalyzes the dehydrogenation of MMPA-CoA to generate MTA-CoA with Glu435 as the catalytic base. Sequence alignment suggests that the proposed catalytic mechanisms of DmdB and DmdC are likely widely adopted by bacteria using the DMSP demethylation pathway. Analysis of the substrate affinities of involved enzymes indicates that Roseobacters kinetically regulate the DMSP demethylation pathway to ensure DMSP functioning and catabolism in their cells. Altogether, this study sheds novel lights on the catalytic and regulative mechanisms of bacterial DMSP demethylation, leading to a better understanding of bacterial DMSP catabolism
Hydrogen sulfide ameliorates isoflurane-induced cognitive impairment in mice: Implication of caspase-3 activation
Purpose: Isoflurane could induce cognitive impairment and activate caspase-3. However, the mechanism of action is unclear and target interventions are unavailable. The present study examined the potential protective function of hydrogen sulfide (H2S) against isoflurane-induced cognitive impairment.Methods: Effects of NaHS (5 mg/kg) on cognitive impairment induced by isoflurane (1.4% for 2 h) were assessed using a fear-conditioning test in a group of 8-month old mice. H4 human neuroglioma cells, which were transfected with upregulated human amyloid precursor protein were treated for 3 or 6 h with 2% isoflurane, in the presence of 100-μM NaHS in the mice. A group of mice treated with normal saline in place of the NaHS in each case served as control. Western blotting, fluorescence assay, and a mitochondrial swelling assay were employed to observe the results of caspase-3 activation, mitochondrial dysfunction, and ROS and ATP levels.Results: NaHS significantly mitigated isoflurane-induced cognitive impairment in mice. In cultured cells, NaHS reduced caspase-3 activation, ROS, mitochondria membrane reduction, mitochondrial permeability transition pore opening, and cellular ATP level. NaHS could ameliorate cognitiveimpariment induced by isoflurane through inhibiting caspase-3 activation, oxidative stress, and mitochondrial dysfunction.Conclusion: These results indicate that hydrogen sulfide (H2S) has potential protective function against isoflurane-induced cognitive impairment. Further investigation of NaHS as an intervention to attenuate anesthesia-associated neurotoxicity is vital.
Keywords: Hydrogen sulfide, isoflurane-cognition,fear conditioning,neurotoxicit
Serum levels of cytokines in water buffaloes experimentally infected with Fasciola gigantica
Fasciola gigantica infection in water buffaloes causes significant economic losses especially 27 in developing countries. Although modulation of the host immune response by cytokine 28 neutralization or vaccination is a promising approach to control infection with this parasite, our 29 understanding of cytokine's dynamic during F. gigantica infection is limited. To address this, 30 we quantified the levels of serum cytokines produced in water buffaloes following experimental 31 infection with F. gigantica. Five buffaloes were infected via oral gavage with 500 viable F. 32 gigantica metacercariae and blood samples were collected from buffaloes one week before 33 infection and for 13 consecutive weeks thereafter. The levels of 10 cytokines in serum samples 34 were simultaneously determined using ELISA. F. gigantica failed to elicit the production of 35 various pro-inflammatory cytokines, including interleukin-1β (IL-1β), IL-2, IL-6, IL-12, and 36 IFN-γ. On the other hand, evidence of a Th2 type response was detected, but only early in the 37 course of parasite colonization and included modest increase in the levels of IL-10 and IL-13. 38 The results also revealed suppression of the immune responses as a feature of chronic F. 39 gigantica infection in buffaloes. Taken together, F. gigantica seems to elicit a modest Th2 40 response at early stage of infection in order to downregulate harmful Th1- and Th17-type 41 inflammatory responses in experimentally infected buffaloes. The full extent of anti-F. 42 gigantica immune response and its relation to pathogenesis requires further study
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