Discriminative Speaker Representation via Contrastive Learning with Class-Aware Attention in Angular Space

The challenges in applying contrastive learning to speaker verification (SV) are that the softmax-based contrastive loss lacks discriminative power and that the hard negative pairs can easily influence learning. To overcome the first challenge, we propose a contrastive learning SV framework incorporating an additive angular margin into the supervised contrastive loss in which the margin improves the speaker representation's discrimination ability. For the second challenge, we introduce a class-aware attention mechanism through which hard negative samples contribute less significantly to the supervised contrastive loss. We also employed gradient-based multi-objective optimization to balance the classification and contrastive loss. Experimental results on CN-Celeb and Voxceleb1 show that this new learning objective can cause the encoder to find an embedding space that exhibits great speaker discrimination across languages.Comment: Accepted by ICASSP 2023, 5 pages, 2 figure

Early Functional and Cognitive Declines Measured by Auditory-Evoked Cortical Potentials in Mice With Alzheimer’s Disease

Alzheimer’s disease (AD) is characterized by a progressive loss of memory and cognitive decline. However, the assessment of AD-associated functional and cognitive changes is still a big challenge. Auditory-evoked cortical potential (AECP) is an event-related potential reflecting not only neural activation in the auditory cortex (AC) but also cognitive activity in the brain. In this study, we used the subdermal needle electrodes with the same electrode setting as the auditory brainstem response (ABR) recording and recorded AECP in normal aging CBA/CaJ mice and APP/PS1 AD mice. AECP in mice usually appeared as three positive peaks, i.e., P1, P2, and P3, and three corresponding negative peaks, i.e., N1, N2, and N3. In normal aging CBA mice, the early sensory peaks P1, N1, and P2 were reduced as age increased, whereas the later cognitive peaks N2, P3, and N3 were increased or had no changes with aging. Moreover, the latency of the P1 peak was increased as age increased, although the latencies of later peaks had a significant reduction with aging. In AD mice, peak P1 was significantly reduced in comparison with wild-type (WT) littermates at young ages, proceeding AD phenotype presentation. In particular, the later cognitive peak P3 was diminished after 3 months old, different from the normal aging effect. However, the latencies of AECP peaks in AD mice generally had no significant delay or changes with aging. Finally, consistent with AECP changes, the accumulation of amyloid precursor protein (APP) at the AC was visible in AD mice as early as 2 months old. These data suggest that AECP could serve as an early, non-invasive, and objective biomarker for detecting AD and AD-related dementia (ADRD)

Woody species have stronger facilitative effects on soil biota than on plants along an aridity gradient

Questions: Woody shrub encroachment affects community structure and composition. However, most studies focus on their effects on understorey plant communities, and the relative importance of shrubs in affecting plants vs. soil biota communities is poorly known. Location: Inner Mongolian Steppe, China. Methods: We examined the effect of shrubs on multiple community attributes, including plants, soil biota (bacteria, fungi and nematodes), and soil fertility, and quantified how these effects changed from semi‐arid to hyper‐arid conditions (from 281 to 110 mm of mean annual precipitation). In addition, we assessed whether the effects of shrubs on plant communities were directly mediated by biotic filtering in seed germination and establishment, or indirectly mediated by plant biomass or soil fertility in the case of soil organisms. Results: The effect of shrubs on soil biota was generally more positive than on plants, and it increased with aridity. We found that a larger proportion of belowground taxa depended on shrub presence (36%) than plants (20%). Soil nematodes and soil bacteria were directly influenced by shrub presence whereas soil fungi were indirectly influenced by enhanced soil fertility. Shrubs also increased plant biomass under all conditions but only increased plant species richness in the most arid conditions. Despite the generally positive effect of shrubs, and the fact that they weakened the filtering effects of aridity on seed germination, aridity was a stronger predictor of changes in species composition than shrub presence was, particularly for plants. Conclusions: Our results illustrate the variety of positive effects of shrubs and show that they are particularly important in supporting biodiversity in the most arid conditions. These strong and positive effects could partially buffer the impacts of increasing aridity on dryland soil biodiversity, but our study suggests that facilitative interactions may not be able to completely mitigate the impacts of increasing aridity on drylands.This research was funded by National Natural Science Foundation of China [31901140, 31570453] and China Scholarship Council. SS was supported by the Spanish Government under a Ramón y Cajal contract (RYC-2016- 20604)

The government’s responses to incompatibility challenges to women: the case studies of Hong Kong and Taiwan

International organizations such as the International Monetary Fund and the World Bank raise concerns about the financial sustainability issues of pension systems. These issues have attracted increasing attention because of the challenges presented by lower growth and financial market volatility, making it harder for governments to fulfil their promises on pension policies (Ebbinghaus, 2011). In order to tackle these challenges, it is not uncommon that governments reform pension schemes with an emphasis on individual responsibility (Yeh et al., 2018). They particularly stress the earnings-related pension measures as an important means to assist people to accumulate pension income (Foster, 2014). Employees are the target group for measures relating to earnings-related pension measures. The amount of pension income accumulated through these measures is highly related to employees’ earnings

Negotiating The Maze: Confronting Dysphagia Together With My Stroke-Afflicted Family Member

Aim: To generate a descriptive theory grounded in the responses of family caregivers caring for their family stroke survivors with dysphagia during hospitalization. Design and Method: A qualitative study employing the grounded theory method was used. Fifteen family caregivers participated in comprehensive interviews. The interview data were analyzed using the constant comparative method. Findings: ‘Negotiating the maze: Confronting dysphagia with my stroke-afflicted family member’ was the core category guiding the care process for dysphagia family members among caregivers. After surviving stroke, the caregivers felt ‘more confusion less rejoicing’ as the antecedent condition. The following three interaction categories were identified: (1) ‘being overwhelmed by nasogastric (NG) tube issues’; (2) ‘searching for the right helper and information’; and (3) ‘food culture conflicts with the formula diet administered through the NG tube’. Additionally, ‘Maintaining positivity’ described the consequence of this process. Conclusions: This study highlights the critical perspective of family members who care for dysphagia stroke survivors in the hospital. Participants were under tremendous pressure during the disease treatment process. However, all attempted to maintain a positive attitude and treasured the chance to accompany their family members. Clinical Relevance: These findings can assist health professionals in charting the effects of dysphagia and in understanding the problems and needs according to the subjective perspectives of family caregivers. They can also provide a necessary foundation for comprehensive care interventions for family caregivers of stroke survivors with dysphagia

A Student Perspective on the Effectiveness of PASS in Seminar Courses: A Mixed-Method Study

The General Education Foundation (GEF) Programme, consisting of two seminar courses, namely “In Dialogue with Humanity” and “In Dialogue with Nature,” has been a common core requirement of The Chinese University of Hong Kong since 2012. Aided by selected classics, students from all faculties engage in dialogues with their teachers and each other to reflect on what it means to have a good life, what an ideal society is, and the nature of intellectual pursuit in the sciences. Reading classics and discussing serious questions in class, however, can be challenging for some students. To help students meet these challenges, Peer Assisted Study Sessions (PASS) were introduced in the pilot stage of GEF in 2010 and, with subsequent refinements, continue to this day. The seminar-style and interdisciplinary nature of GEF makes it an atypical case for PASS. This paper will examine and evaluate how PASS can improve student learning in seminar-style courses like GEF with a mixed-method study from a student perspective. According to evidence from online surveys and focus group interviews, PASS successfully 1) improves students’ understanding of the course content at a cognitive level, 2) assists and motivates them to prepare better for seminar discussions, effecting a behavioural change, and 3) facilitates affective learning outcomes in terms of confidence and motivation. Major challenges—including students’ misperceptions about PASS, differences in leaders’ approaches and organisational difficulties—are identified. Proposed solutions to these challenges will also be discussed

A cost-effective and universal strategy for complete prokaryotic genomic sequencing proposed by computer simulation

Background: Pyrosequencing techniques allow scientists to perform prokaryotic genome sequencing to achieve the draft genomic sequences within a few days. However, the assemblies with shotgun sequencing are usually composed of hundreds of contigs. A further multiplex PCR procedure is needed to fill all the gaps and link contigs into complete chromosomal sequence, which is the basis for prokaryotic comparative genomic studies. In this article, we study various pyrosequencing strategies by simulated assembling from 100 prokaryotic genomes. Findings. Simulation study shows that a single end 454 Jr. run combined with a paired end 454 Jr. run (8 kb library) can produce: 1) ∼90% of 100 assemblies with 99.99%; 4) average false gene duplication rate is < 0.7%; 5) average false gene loss rate is < 0.4%. Conclusions: A single end 454 Jr. run combined with a paired end 454 Jr. run (8 kb library) is a cost-effective way for prokaryotic whole genome sequencing. This strategy provides solution to produce high quality draft assemblies for most of prokaryotic organisms within days. Due to the small number of assembled scaffolds, the following multiplex PCR procedure (for gap filling) would be easy. As a result, large scale prokaryotic whole genome sequencing projects may be finished within weeks. © 2012 Jiang et al; BioMed Central Ltd.published_or_final_versio