Speech Dereverberation Based on Integrated Deep and Ensemble Learning Algorithm

Reverberation, which is generally caused by sound reflections from walls, ceilings, and floors, can result in severe performance degradation of acoustic applications. Due to a complicated combination of attenuation and time-delay effects, the reverberation property is difficult to characterize, and it remains a challenging task to effectively retrieve the anechoic speech signals from reverberation ones. In the present study, we proposed a novel integrated deep and ensemble learning algorithm (IDEA) for speech dereverberation. The IDEA consists of offline and online phases. In the offline phase, we train multiple dereverberation models, each aiming to precisely dereverb speech signals in a particular acoustic environment; then a unified fusion function is estimated that aims to integrate the information of multiple dereverberation models. In the online phase, an input utterance is first processed by each of the dereverberation models. The outputs of all models are integrated accordingly to generate the final anechoic signal. We evaluated the IDEA on designed acoustic environments, including both matched and mismatched conditions of the training and testing data. Experimental results confirm that the proposed IDEA outperforms single deep-neural-network-based dereverberation model with the same model architecture and training data

Size-selective purification of hepatitis B virus-like particle in flow-through chromatography: types of ion exchange adsorbent and grafted polymer architecture

Hepatitis B virus-like particles expressed in Escherichia coli were purified using anion exchange adsorbents grafted with polymer poly(oligo(ethylene glycol) methacrylate) in flow-through chromatography mode. The virus-like particles were selectively excluded, while the relatively smaller sized host cell proteins were absorbed. The exclusion of virus-like particles was governed by the accessibility of binding sites (the size of adsorbents and the charge of grafted dextran chains) as well as the architecture (branch-chain length) of the grafted polymer. The branch-chain length of grafted polymer was altered by changing the type of monomers used. The larger adsorbent (90 μm) had an approximately twofold increase in the flow-through recovery, as compared to the smaller adsorbent (30 μm). Generally, polymer-grafted adsorbents improved the exclusion of the virus-like particles. Overall, the middle branch-chain length polymer grafted on larger adsorbent showed optimal performance at 92% flow-through recovery with a purification factor of 1.53. A comparative study between the adsorbent with dextran grafts and the polymer-grafted adsorbent showed that a better exclusion of virus-like particles was achieved with the absorbent grafted with inert polymer. The grafted polymer was also shown to reduce strong interaction between binding sites and virus-like particles, which preserved the particles' structure

Dynamic behaviours of damaged stability for floating energy storage unit after accidental collision

The transient dynamic behaviour of floating energy storage unit (FESU) is a result of coupling between three non-linear effects, which are sloshing of floodwater, wave loading, and FESU dynamics. The coupling of these effects would result in the catastrophic failure of the FESU in extreme conditions. Computational Fluid Dynamics (CFD) has shown that it holds great potential in solving the problem in the time domain, which is suitable for the transient stage. In this study, CFD simulation of damaged stability was conducted by using OpenFOAM to determine the dynamic response of FESU under the effects of floodwater and wave in transient flooding. OpenFOAM CFD simulation was conducted for the flooding of barge shaped FESU with different water inlet and air outlet sizes in still water condition followed by damaged stability in Stokes’ fifth-order beam wave and head wave condition. Dynamic responses of FESU, such as roll, pitch, heave, and floodwater volume flow rates were determined using the dynamic meshing solver of OpenFOAM. Simulation results showed similarity to experimental results within the time frame of 16 seconds. Reduction in water inlet area and air outlet area decreased the flooding time and flow rate of flood water. The amplitude of vibration of roll and pitch motion increased as the flood water volume was increased due to the force of floodwater exerted on the wall. Sloshing effects also caused the model to roll and pitch in secondary vibrational motion. Due to the coupling effect of the three non-linear criteria, the inflow and outflow of floodwater changed with time, which concludes that transient effects should not be ignored in the damaged stability assessment of FESU

Mental awareness improved mild cognitive impairment and modulated gut microbiome

There is ample scientific and clinical evidence of the effects of gut microbiota on the brain but no definitive evidence that the brain can affect changes in gut microbiota under the bi-directional gut-brain axis concept. As there is no pharmacotherapeutic intervention for the early stages of cognitive decline, research has focused on cognitive stimulation in reversing or slowing the impairment. Elderly patients diagnosed with mild cognitive impairment underwent a randomized-control trial of mindful awareness practice. Neuropsychological assessments, inflammatory markers, and gut microbiota profiles were tested. Here, we report that their cognitive impairment was improved and associated with changes in gut bacterial profile. A cognition-score-dependent-abundance was observed in Ruminococcus vs Recognition Trials (RT), Digit Span Backward (DSB), Semantic Fluency Span (SFS) and Memory Domain (MD); Coprococcus vs DSB, Color Trails Test 2 (CTT2) and Block Design (BD); Parabacteroides vs DSB and SFS; Fusobacterium vs DSB and CTT2; Enterobacteriaceae vs BD and SFS; Ruminococcaceae vs DSB; Phascolarctobacterium vs MD. The study showed for the first-time, alteration in the cognitive capacity leading to the corresponding changes in microbiota profiles. This strongly suggests that signals from the different segments of brain could dictate directly or indirectly the abundances of specific gut microbes

Metaphoric drawing narrative career counselling: Teaching work value and career identity statuses via experiential learning method

Metaphoric cards as a tool in counselling sessions are getting more scholarly attention in the fields of career counselling and education. In general, metaphoric cards consist of visual image that depicted daily life events and human expressions which are used as an alternative form of expression other than verbal communication. This paper aims to introduce metaphorical drawing as the experiential learning method in teaching narrative career counselling course. This is a qualitative study consists of metaphorical drawing and written reflection with six participants by using thematic analysis research method. The metaphorical drawing results revealed that, two new themes had been emerged in the exploration of work value and identity status. The results showed that some but not all participants benefited from the metaphorical drawing session to fully express their identity statuses. However, the combination of written reflection and verbal explanation of the metaphorical drawing did help the participants to convey their identity concern. In conclusion, metaphorical drawing session could be adopted in counsellor education to promote more understanding of narrative counselling technique and also in teaching work value and career identity status. For future research, it is important to look into how metaphorical technique can be introduced to school students in understanding their career choices

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Temporal Variation of Bacterial Respiration and Growth Efficiency in Tropical Coastal Waters ▿

We investigated the temporal variation of bacterial production, respiration, and growth efficiency in the tropical coastal waters of Peninsular Malaysia. We selected five stations including two estuaries and three coastal water stations. The temperature was relatively stable (averaging around 29.5°C), whereas salinity was more variable in the estuaries. We also measured dissolved organic carbon and nitrogen (DOC and DON, respectively) concentrations. DOC generally ranged from 100 to 900 μM, whereas DON ranged from 0 to 32 μM. Bacterial respiration ranged from 0.5 to 3.2 μM O2 h−1, whereas bacterial production ranged from 0.05 to 0.51 μM C h−1. Bacterial growth efficiency was calculated as bacterial production/(bacterial production + respiration), and ranged from 0.02 to 0.40. Multiple correlation analyses revealed that bacterial production was dependent upon primary production (r2 = 0.169, df = 31, and P < 0.02) whereas bacterial respiration was dependent upon both substrate quality (i.e., DOC/DON ratio) (r2 = 0.137, df = 32, and P = 0.03) and temperature (r2 = 0.113, df = 36, and P = 0.04). Substrate quality was the most important factor (r2 = 0.119, df = 33, and P = 0.04) for the regulation of bacterial growth efficiency. Using bacterial growth efficiency values, the average bacterial carbon demand calculated was from 5.30 to 11.28 μM C h−1. When the bacterial carbon demand was compared with primary productivity, we found that net heterotrophy was established at only two stations. The ratio of bacterial carbon demand to net primary production correlated significantly with bacterial growth efficiency (r2 = 0.341, df = 35, and P < 0.001). From nonlinear regression analysis, we found that net heterotrophy was established when bacterial growth efficiency was <0.08. Our study showed the extent of net heterotrophy in these waters and illustrated the importance of heterotrophic microbial processes in coastal aquatic food webs

Flipside Asia: ah noi's guide to Singapore.

This documentary is a social satire about the consumerist society of Singapore that is presented in a pseudo-travelogue visual format.Bachelor of Communication Studie