Boundary element method modelling of KEMAR for binaural rendering: Mesh production and validation

Head and torso simulators are used extensively within acoustic research, often in place of human subjects in time-consuming or repetitive experiments. Particularly common is the Knowles Electronics Manikin for Acoustic Research (KEMAR), which has the acoustic auditory properties of an average human head. As an alternative to physical acoustic measurements, the boundary element method (BEM) is widely used to calculate the propagation of sound using computational models of a scenario. Combining this technique with a compatible 3D surface mesh of KEMAR would allow for detailed binaural analysis of speaker distributions and decoder design - without the disadvantages associated with making physical measurements. This paper details the development and validation of a BEM-compatible mesh model of KEMAR, based on the original computer-aided design (CAD) file and valid up to 20 kHz. Use of the CAD file potentially allows a very close match to be achieved between the mesh and the physical manikin. The mesh is consistent with the original CAD description, both in terms of overall volume and of local topology, and the numerical requirements for BEM compatibility have been met. Computational limitations restrict usage of the mesh in its current state, so simulation accuracy cannot as yet be compared with acoustically measured HRTFs. Future work will address the production of meshes suitable for use in BEM with lower computational requirements, using the process validated in this wor

Establishing Social Learning in an Engineering MOOC : Benefits for Diversity and Inclusion in Engineering Education

Recent Higher Education Statistics Agency data shows that only 20% of engineering students at UK Universities are female, despite the hard work being undertaken by many educational institutions to address this gender imbalance via outreach events and special interventions focussing on girls/women in STEM. It has been argued that student-centred teaching methods, together with changes in the engineering curriculum itself, which emphasise the social, creative, and human-centred aspects of the discipline, are required to effect real change in engaging with those from traditionally underrepresented groups. Through analysing quantitative data on age, gender, learner type, and commenting rates in peer-to-peer discussions, we examine the development and delivery of an engineering MOOC, before, during, and after COVID-19-related lockdowns in the UK, to identify what aspects of online learning might be harnessed to improve diversity in engineering education. The results show that the MOOC attracted a better gender balance than reported for UK-based in-person engineering programmes. In addition, we show that careful structuring of discussion prompts encouraged higher levels of social learning. We recommend the continued use of interactive and discursive elements within a blended learning environment to positively impact diversity and inclusion in engineering education specifically, and STEM education in general

Long non-coding RNA ROCR contributes to SOX9 expression and chondrogenic differentiation of human mesenchymal stem cells

Long non-coding RNAs (lncRNAs) are expressed in a highly tissue-specific manner where they function in various aspects of cell biology, often as key regulators of gene expression. In this study we established a role for lncRNAs in chondrocyte differentiation. Using RNA sequencing we identified a human articular chondrocyte repertoire of lncRNAs from normal hip cartilage donated by neck of femur fracture patients. Of particular interest are lncRNAs upstream of the master chondrocyte transcription factor SOX9 locus. SOX9 is an HMG-box transcription factor which is essential for chondrocyte development by directing the expression of chondrocyte specific genes. Two of these lncRNAs are upregulated during chondrogenic differentiation of MSCs. Depletion of one of these lncRNA, LOC102723505, which we termed ROCR (regulator of chondrogenesis RNA), by RNAi disrupted MSC chondrogenesis, concomitant with reduced cartilage-specific gene expression and incomplete matrix component production, indicating an important role in chondrocyte biology. Specifically, SOX9 induction was significantly ablated in the absence of ROCR, and overexpression of SOX9 rescued the differentiation of MSCs into chondrocytes. Our work sheds further light on chondrocyte specific SOX9 expression and highlights a novel method of chondrocyte gene regulation involving a lncRNA

Current Developments and Future Trends for the OAI Protocol for Metadata Harvesting

The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) has been widely adopted since its initial release in 2001. Initially developed as a means to federate access to diverse e-print archives through metadata harvesting and aggregation, the protocol has demonstrated its potential usefulness to a broad range of communities. Two years out from the release of the stable production version of the protocol (2.0), there are many interesting developments within the OAI community. Communities of interest have begun to use the protocol to aggregate metadata relative to their needs. The development of a registry of OAI data providers with browsing and searching capabilities as well as accessibility to machine processing is helping to provide a scalable solution to the question of who is providing what via the OAI protocol. Work is progressing on the technical infrastructure for extending the OAI protocol beyond the traditional harvesting structure. However, serious challenges, particularly for service providers, still exist. This paper provides an overview of the current OAI environment and speculates on future directions for the protocol and OAI community.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/59513/1/Shreevesetal_576-589_LT_53_4.pd

The Impact of Gender on Conference Authorship in Audio Engineering : Analysis Using a New Data Collection Method

Contribution: This paper provides evidence of the lack of gender diversity at audio engineering conferences, using a novel and inclusive gender determination method to produce a new dataset of author gender. Background: Audio engineering has historically been male-dominated; whilst the number of non-male audio engineers has increased recently, the industry mindset has changed very little. Studies into the gender diversity of this field are required to force a shift in mindset and create a more inclusive environment. Research Questions: To what extent is there an imbalance in the representation of different genders at audio engineering conferences? Do conference topic, presentation type, or author position have an impact on the gender balance? Methodology: A novel method was designed to obtain pronouns of authors where possible, avoiding removal of data or potential false positives. The main limitation of this methodology is the time required for gender determination. Gender composition was analyzed across 20 conferences, with gender balance further analyzed within four key categories: conference topic, presentation type, position in the author byline, and the number of authors listed. Findings: This data-driven study demonstrates a clear lack of gender diversity in conference authorship in audio engineering. The results show low overall representation of non-male authors at audio engineering conferences, with significant differences across conference topics, and a notable lack of gender diversity within invited presentations. Index Terms— Audio Engineering, Conferences, Gender, Underrepresentation, Bias, Discrimination, STEM, Engineering Pipelin

Three-body resonances in He-6, Li-6, and Be-6, and the soft dipole mode problem of neutron halo nuclei

Using the complex scaling method, the low-lying three-body resonances of $^6$He, $^6$Li, and $^6$Be are investigated in a parameter-free microscopic three-cluster model. In $^6$He a 2$^+$, in $^6$Li a 2$^+$ and a 1$^+$, and in $^6$Be the 0$^+$ ground state and a 2$^+$ excited state is found. The other experimentally known 2$^+$ state of $^6$Li cannot be localized by our present method. We have found no indication for the existence of the predicted 1$^-$ soft dipole state in $^6$He. We argue that the sequential decay mode of $^6$He through the resonant states of its two-body subsystem can lead to peaks in the excitation function. This process can explain the experimental results in the case of $^{11}$Li, too. We propose an experimental analysis, which can decide between the soft dipole mode and the sequential decay mode.Comment: REVTEX, Submitted to Phys. Rev. C, 12 pages, 2 postscript figures are available upon request. CALTECH, MAP-16

Duration of the parasitic phase determines subsequent performance in juvenile freshwater pearl mussels (Margaritifera margaritifera)

Host–parasite systems have been useful in understanding coevolutionary patterns in sympatric species. Based on the exceptional interaction of the long‐lived and highly host‐specific freshwater pearl mussel (FPM; Margaritifera margaritifera) with its much shorter‐lived host fish (Salmo trutta or Salmo salar), we tested the hypotheses that a longer duration of the parasitic phase increases fitness‐related performance of mussels in their subsequent post parasitic phase, and that temperature is the main factor governing the duration of the parasitic phase. We collected juvenile mussels from naturally and artificially infested fish from eight rivers in Norway. Excysted juvenile mussels were maintained separately for each collection day, under similar temperature and food regimes, for up to 56 days. We recorded size at excystment, post excystment growth, and survival as indicators of juvenile fitness in relation to the duration of the parasitic phase. We also recorded the daily average temperatures for the entire excystment period. We observed strong positive relationships between the length of the parasitic phase and the post parasitic growth rate, size at excystment and post parasitic survival. Temperature was identified as an important factor governing excystment, with higher temperatures decreasing the duration of the parasitic phase. Our results indicate that juvenile mussels with the longest parasitic phase have better resources (larger size and better growth rate) to start their benthic developmental phase and therefore to survive their first winter. Consequently, the parasitic phase is crucial in determining subsequent survival. The temperature dependence of this interaction suggests that climate change may affect the sensitive relationship between endangered FPMs and their fish hosts.publishedVersio

Joint care can outweigh costs of nonkin competition in communal breeders

Competition between offspring can greatly influence offspring fitness and parental investment decisions, especially in communal breeders where unrelated competitors have less incentive to concede resources. Given the potential for escalated conflict, it remains unclear what mechanisms facilitate the evolution of communal breeding among unrelated females. Resolving this question requires simultaneous consideration of offspring in noncommunal and communal nurseries, but such comparisons are missing. In the Seychelles warbler Acrocephalus sechellensis, we compare nestling pairs from communal nests (2 mothers) and noncommunal nests (1 mother) with singleton nestlings. Our results indicate that increased provisioning rate can act as a mechanism to mitigate the costs of offspring rivalry among nonkin. Increased provisioning in communal broods, as a consequence of having 2 female parents, mitigates any elevated costs of offspring rivalry among nonkin: per-capita provisioning and survival was equal in communal broods and singletons, but lower in noncommunal broods. Individual offspring costs were also more divergent in noncommunal broods, likely because resource limitation exacerbates differences in competitive ability between nestlings. It is typically assumed that offspring rivalry among nonkin will be more costly because offspring are not driven by kin selection to concede resources to their competitors. Our findings are correlational and require further corroboration, but may help explain the evolutionary maintenance of communal breeding by providing a mechanism by which communal breeders can avoid these costs

Increased hippocampal excitability in miR-324-null mice

MicroRNAs are non-coding RNAs that act to downregulate the expression of target genes by translational repression and degradation of messenger RNA molecules. Individual microRNAs have the ability to specifically target a wide array of gene transcripts, therefore allowing each microRNA to play key roles in multiple biological pathways. miR-324 is a microRNA predicted to target thousands of RNA transcripts and is expressed far more highly in the brain than in any other tissue, suggesting that it may play a role in one or multiple neurological pathways. Here we present data from the first global miR-324-null mice, in which increased excitability and interictal discharges were identified in vitro in the hippocampus. RNA sequencing was used to identify differentially expressed genes in miR-324-null mice which may contribute to this increased hippocampal excitability, and 3′UTR luciferase assays and western blotting revealed that two of these, Suox and Cd300lf, are novel direct targets of miR-324. Characterisation of microRNAs that produce an effect on neurological activity, such as miR-324, and identification of the pathways they regulate will allow a better understanding of the processes involved in normal neurological function and in turn may present novel pharmaceutical targets in treating neurological disease

Fish and mussels: importance of fish for freshwater mussel conservation

Co-extinctions are increasingly recognized as one of the major processes leading to the global biodiversity crisis, but there is still limited scientific evidence on the magnitude of potential impacts and causal mechanisms responsible for the decline of affiliate (dependent) species. Freshwater mussels (Bivalvia, Unionida), one of the most threatened faunal groups on Earth, need to pass through a parasitic larval (glochidia) phase using fishes as hosts to complete their life cycle. Here, we provide a synthesis of published evidence on the fish–mussel relationship to explore possible patterns in co-extinction risk and discuss the main threats affecting this interaction. We retrieved 205 publications until December 2015, most of which were performed in North America, completed under laboratory conditions and were aimed at characterizing the life cycle and/or determining the suitable fish hosts for freshwater mussels. Mussel species were reported to infest between one and 53 fish species, with some fish families (e.g., Cyprinidae and Percidae) being used more often as hosts than others. No relationship was found between the breadth of host use and the extinction risk of freshwater mussels. Very few studies focused on threats affecting the fish–mussel relationship, a knowledge gap that may impair the application of future conservation measures. Here, we identify a variety of threats that may negatively affect fish species, document and discuss the concomitant impacts on freshwater mussels, and suggest directions for future studies.The Portuguese Foundation for Science and Technology—FCT through POPH/FSE funds supported VM, MI and MLL under grants (SFRH/BD/108298/2015), (SFRH/BPD/90088/2012), (SFRH/BD/115728/2016), respectively. KD acknowledges the support from the Czech Science Foundation (13-05872S). RS acknowledges the support of the strategic programme UID/BIA/04050/2013 (POCI-01-0145- FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI). This study was conducted as part of the project FRESHCO: Multiple implications of invasive species on Freshwater Mussel co-extinction processes, supported by FCT (contract: PTDC/AGRFOR/1627/2014)