The Millennium Eruption of Changbaishan Tianchi Volcano is VEI 6, not 7

The Millennium Eruption (AD 946–947) of Changbaishan Tianchi Volcano is one of the largest known eruptions in recorded history. With the help of previously published isopachs and distal ash thicknesses, we re-calculate the bulk volume of its distal eruptive product, the B-Tm ash, as 27–62 km3 and the total eruption volume as 40–98 km3. The updated volume estimates are around half of those estimated by previous studies of this seminal eruption. Our work shows that the Millennium Eruption is a VEI-6 eruption, rather than VEI-7 as previously envisaged, and its magnitude is also lower than previously thought. This has implications for regional frequency-magnitude relationships and may also partially explain the limited regional, rather than global, climatic effects of the Millennium Eruption

Intermittent non-axial dipolar-field dominance of twin Laschamp excursions

Geomagnetic excursions represent the dynamic nature of the geodynamo. Accumulated palaeomagnetic records indicate that such excursions are dominated by dipolar-fields, but exhibit different structures. Here we report a palaeomagnetic record from the varved sediments of Lake Suigetsu, central Japan, which reveals fine structures in the Laschamp Excursion and a new post-Laschamp excursion that coincides with the Δ14C maxima. The record’s high-resolution chronology provides IntCal20 mid-ages and varve-counted durations. Both excursions comprise multiple subcentennial directional-swings. Simulations of filtering effects on sediment-magnetisations demonstrate that this high-resolution record replicates most of the features in existing, lower-resolution Laschamp excursion records, including the apparent clockwise open-loop of the virtual geomagnetic pole pass. The virtual geomagnetic poles during the ‘swing’ phases make four clusters centred in hemispherically-symmetric regions, three of which encompass the virtual geomagnetic poles associated with the Laschamp Excursion recorded in lavas at various locations. The stationary dipolar-field sources under each cluster should have intermittently dominated one after another during the excursions

Understanding levels of social economy development : an examination of Northern Canadian communities

This study offers a preliminary analysis of the role specific social factors have on social economy development in the Yukon, Northwest Territories and Nunavut. Because of the marked differences in levels of social economy development in Northern Canadian communities, this research attempts to explain these variations through an examination of social variables that have been identified as impacting levels of developmen

Clonal Expansion of Lgr5-Positive Cells from Mammalian Cochlea and High-Purity Generation of Sensory Hair Cells

Death of cochlear hair cells, which do not regenerate, is a cause of hearing loss in a high percentage of the population. Currently, no approach exists to obtain large numbers of cochlear hair cells. Here, using a small-molecule approach, we show significant expansion (>2,000-fold) of cochlear supporting cells expressing and maintaining Lgr5, an epithelial stem cell marker, in response to stimulation of Wnt signaling by a GSK3β inhibitor and transcriptional activation by a histone deacetylase inhibitor. The Lgr5-expressing cells differentiate into hair cells in high yield. From a single mouse cochlea, we obtained over 11,500 hair cells, compared to less than 200 in the absence of induction. The newly generated hair cells have bundles and molecular machinery for transduction, synapse formation, and specialized hair cell activity. Targeting supporting cells capable of proliferation and cochlear hair cell replacement could lead to the discovery of hearing loss treatments.United States. National Institutes of Health (DE-013023)United States. National Institutes of Health (DC-007174)United States. National Institutes of Health (DC-013909)United States. National Institutes of Health (RR-00168

The Importance of Collaborative Design for Narrowing the Gender Gap in Engineering: An Analysis of Engineering Identity Development in Elementary Students

Research suggests that, to narrow the gender gap in engineering, we should focus on helping young girls identify with engineering both because gendered attitudes emerge around kindergarten and because identity is more predictive than performance on persistence in the field. This qualitative study sought to understand the impact of collaborative engineering design on the development of engineering identities in elementary-school students and compared the findings across gender. We focused on three tiers of collaboration embedded into the engineering design process: peer groups, role models, and shared goals. More specifically, the elementary students worked in small teams and partnered with undergraduate engineers to help design and build dancing robots that come together for a coordinated dance performance. We used ethnographic methods, including pre- and post-program student interviews, video-recorded program sessions, and documentation of student work, to investigate elementary students’ engineering identities. Three themes emerged from our analysis. First, working with peers encouraged students who were initially uninterested in engineering, the majority of whom were girls, to join the program and helped them to engage in the activities. Second, partnering with engineer role models contributed to the elementary students’ developing identities as engineers: The girls were most influenced by the personal bonds they formed, while the boys were most influenced by the technical skills they learned. Third, all girls and most boys preferred the idea of working toward a shared goal over competitive projects that, as described by the students, can cause bad feelings and hurt friendships. Our work supports and extends elementary engineering literature by considering the role of multiple tiers of collaboration in identity development in girls and boys. Our results suggest that engineering design programs that foster collaboration can help more students, especially more girls, engage in and identify with engineering, thereby contributing to the narrowing of the gender gap

Eruption plumes extended more than 30 km in altitude in both phases of the Millennium eruption of Paektu (Changbaishan) volcano

The Millennium Eruption of Paektu volcano, on the border of China and North Korea, generated tephra deposits that extend >1000 km from the vent, making it one of the largest eruptions in historical times. Based on observed thicknesses and compositions of the deposits, the widespread tephra dispersal is attributed to two eruption phases fuelled by chemically distinct magmas that produced both pyroclastic flows and fallout deposits. We used an ensemble-based method with a dual step inversion, in combination with the FALL3D atmospheric tephra transport model, to constrain these two different phases. The volume of the two distinct phases has been calculated. The results indicate that about 3-16 km3 (with a best estimate of 7.2 km3) and 4-20 km3 (with a best estimate of 9.3 km3) of magma were erupted during the comendite and trachyte phases of the eruption, respectively. Eruption rates of up to 4 × 108 kg/s generated plumes that extended 30-40 km up into the stratosphere during each phase

How reliable is µXRF core scanning at detecting tephra layers in sedimentary records?:A case study using the Lake Suigetsu archive (central Japan)

Here, we evaluate the ability of micro X-ray fluorescence (µXRF) core scanning to identify non-visible volcanic ash (cryptotephra) layers in sedimentary records. Its suitability is assessed using the annually resolved lacustrine sediments of Lake Suigetsu (Japan) for which there is high-resolution ITRAX µXRF core scanning data, and a detailed crypto-tephrostratigraphy (formerly established via density separation techniques). The studied core sections contain 10 visible and 30 cryptotephra markers that span a range of glass concentrations (from 1000 to >20 000 shards per gram of dried sediment) and compositions (basalts, trachy-andesites, phonolites, trachytes and rhyolites), thus providing an ideal case study. The ITRAX core scanner produced recognisable µXRF elemental responses for the visible ash layers, including those just 1 mm thick. However, just 10% of the cryptotephra layers could be unequivocally identified. Although this study demonstrates that µXRF core scanning should not be used as an independent method within a similar geological setting, we show it can provide a powerful tool alongside traditional techniques. Where detected, µXRF profiles can verify and refine cryptotephra positions (here to a sub-millimetre resolution), and help establish reworking signatures. These insights create possibilities for ultra-precise synchronisation of records, improved chronological modelling and help generate more complete eruption histories

Bimolecular Fluorescence Complementation of Alpha-synuclein Demonstrates its Oligomerization with Dopaminergic Phenotype in Mice

Alpha-synuclein (αSyn) is encoded by the first causal gene identified in Parkinson's disease (PD) and is the main component of Lewy bodies, a pathological hallmark of PD. aSyn-based animal models have contributed to our understanding of PD pathophysiology and to the development of therapeutics. Overexpression of human wildtype αSyn by viral vectors in rodents recapitulates the loss of dopaminergic neurons from the substantia nigra, another defining pathological feature of the disease. The development of a rat model exhibiting bimolecular fluorescence complementation (BiFC) of αSyn by recombinant adeno-associated virus facilitates detection of the toxic αSyn oligomers species. We report here neurochemical, neuropathological and behavioral characterization of BiFC of αSyn in mice. Overexpression and oligomerization of αSyn through BiFC is detected by conjugated fluorescence. Reduced striatal dopamine and loss of nigral dopaminergic neurons are accompanied neuroinflammation and abnormal motor activities. Our mouse model may provide a valuable tool to study the role of αSyn in PD and to explore therapeutic approaches

Informing mHealth and Web-Based Eating Disorder Interventions: Combining Lived Experience Perspectives With Design Thinking Approaches

Background: App-based interventions designed to prevent and treat eating disorders have considerable potential to overcome known barriers to treatment seeking. Existing apps have shown efficacy in terms of symptom reduction; however, uptake and retention issues are common. To ensure that apps meet the needs and preferences of those for whom they were designed, it is critical to understand the lived experience of potential users and involve them in the process of design, development, and delivery. However, few app-based interventions are pretested on and co-designed with end users before randomized controlled trials. Objective: To address the issue, this study used a highly novel design thinking approach to provide the context and a lived experience perspective of the end user, thus allowing for a deeper level of understanding. Methods: In total, 7 young women (mean age 25.83, SD 5.34, range 21-33 years) who self-identified as having a history of body image issues or eating disorders were recruited. Participants were interviewed about their lived experience of body image and eating disorders and reported their needs and preferences for app-based eating disorder interventions. Traditional (thematic analysis) and novel (empathy mapping; visually depicting and empathizing with the user’s personal experience) analyses were performed, providing a lived experience perspective of eating disorders and identifying the needs and preferences of this population in relation to app-based interventions for eating disorders. Key challenges and opportunities for app-based eating disorder interventions were also identified. Results: Findings highlighted the importance of understanding and identifying problematic eating disorder symptoms for the user, helpful practices for recovery that identify personal values and goals, the role of social support in facilitating hope, and aspects of usability to promote continued engagement and recovery. Conclusions: Practical guidance and recommendations are described for those developing app-based eating disorder interventions. These findings have the potential to inform practices to enhance participant uptake and retention in the context of app-based interventions for this population