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Meteoric beryllium-10 fluxes from soil inventory measurements in the East River watershed, Colorado, USA
No full textMeteoric beryllium-10 (10Bemet) has a wide range of applications as a geochronometer and tracer of geological processes. 10Bemet is produced in the atmosphere by cosmic rays and delivered to Earth’s surface primarily via precipitation. 10Bemet is particularly suitable for quantifying surface process rates where use of in situ-produced 10Be is challenging, such as landscapes with quartz-poor bedrock. However, using 10Bemet for dating and quantifying surface process rates requires constraining depositional fluxes across space and time. Although empirical and physical models for predicting fluxes exist, the predictions can deviate substantially from measured values. Here we quantify 10Bemet flux in the East River watershed in Colorado, USA where precipitation is dominated by snowfall. We measured the 10Bemet inventory in soils on five glacial moraines 13–18 ka in age that span 700 m of elevation and calculated 10Bemet fluxes by dividing each inventory by moraine age. Inheritance-corrected fluxes range from 1.12–3.79x106 atoms cm-2 yr-1, and are well correlated with elevation, mean annual precipitation, mean snow depth, and snow water equivalent (R2 = 0.84 to 0.99). Regression models based on elevation, precipitation, snow depth and snow water equivalent predict watershed-averaged fluxes of 1.23x106–3.62x106 atoms cm-2 yr-1. Predicted fluxes from a published empirical model that estimates fluxes as a function of precipitation were within a factor of 1.1–1.6 of measured values at each site. Fluxes predicted by physically-based general circulation models (GCM) are generally within a factor of three of our estimated watershed-averaged values, but the GCM predictions are too coarse to capture the within-watershed spatial variability in fluxes. Our results highlight both the importance of factors that drive variability in 10Bemet delivery to soils and how local calibration can improve estimates of 10Bemet flux in mountain watersheds.Department of EnergyMaster of Science (M.S.
Module 2
No full textThis module contains materials on cartographic basics (data formats, querying, shapefile basics) concepts and practice, and a brief exercise reviewing Module 1 concepts
Constitutive heterochromatin controls nuclear mechanics, morphology, and integrity through H3K9me3 mediated chromocenter compaction
Full text linkAberrant nuclear morphology is a hallmark of human disease and causes nuclear dysfunction. Perturbed nuclear mechanics via reduced heterochromatin weakens the nucleus resulting in nuclear blebbing and rupture. While the role of heterochromatin is known, the separate roles of constitutive heterochromatin methylation states remains elusive. Using MEF and HT1080 cells, we isolated the individual contribution of constitutive heterochromatin H3K9 methylation states through histone methyltransferase inhibitors. Inhibition of SUV39H1 via Chaetocin downregulates H3K9 trimethylation (me3), while inhibition of G9a via BIX01294 downregulates H3K9 dimethylation (me2). Overall, the loss of H3K9me3 increased nuclear blebbing and rupture in interphase nuclei due to decreased nuclear rigidity from decompaction of chromocenters. Oppositely, loss of H3K9me2 decreased nuclear blebbing and rupture with increased nuclear rigidity and more compact chromocenters. We show that facultative heterochromatin and HP1 alpha are non-essential for chromocenter compaction. Constitutive heterochromatin provides essential nuclear mechanical support to maintain nuclear shape and integrity through chromocenter compaction
Module 4
No full textThis unit contains materials on projections concepts and practice, and a brief exercise reviewing Module 3 concepts
Brittle-to-Ductile Transitions of Polyelectrolyte Complexes: Humidity, Temperature, and Salt
No full textPolyelectrolyte complexation is an entropically driven, associative phase separation that results in a polymer-rich polyelectrolyte complex (PEC) and a polymer-poor supernatant. PECs show promise as a new class of sustainable materials since they can be processed using aqueous solutions rather than organic solvents. Previous reports have looked at the mechanical properties and glass transitions of PECs as a function of temperature, relative humidity (rH), and salt concentration (CS), but establishing a universal understanding of how these parameters affect PEC mechanics has yet to be achieved. We examined the effects of temperature, rH, and CS on the mechanical properties of PECs formed from poly(methacrylic acid) and poly(trimethyl aminoethyl methacrylate) with a goal of establishing design rules for their mechanical response. Relative humidity was shown to have the most dramatic effect on the mechanical properties, with temperature and salt concentration having far less of an impact. Furthermore, we observed that the glass transition of PECs is tied to both temperature and relative humidity, creating a glass transition rHg/Tg line that can be modulated by added salt. Finally, we looked at the thermodynamics behind the glass transition of PECs, which yielded similar energies as the condensation of water. We propose the use of water and/or salt as a low energy and efficient method of processing PECs for various applications
Self-perceived middle-distance race pace is faster in advanced footwear technology spikes
No full textBackground: Quantifying the potential benefits of advanced footwear technology (AFT) track shoes (i.e., “spikes”) in middle-distance events is
challenging, because repeated maximal effort trials (as in sprinting) or aerobic running economy trials (as in long-distance running) are not
feasible.
Methods: We introduce a novel approach to assess the benefits of AFT spikes, consisting of a series of 200-m runs at self-perceived middle-distance race pace with 10 min recovery, and conduct 4 experiments to evaluate its validity, sensitivity, reproducibility, and utility.
Results: In Experiment 1, participants ran 1.2% slower in spikes with 200 g added mass vs. control spikes, which is exactly equal to the known
effects of shoe mass on running performance. In Experiment 2, participants ran significantly faster in AFT prototype spikes vs. traditional spikes.
In Experiment 3, we compared 2 other AFT prototype spikes against traditional spikes on 3 separate days. Group-level results were consistent
across days, but our data indicates that at least 2 separate sessions are needed to evaluate individual responses. In Experiment 4, participants ran
significantly faster in 2 AFT spike models vs. traditional spikes (2.1% and 1.6%). Speed was similar between a third AFT spike model and the
traditional spikes. These speed results were mirrored by changes in step length as participants took significantly longer steps in the 2 faster AFT
spike models (2.3% and 1.9%), while step length was similar between the other spikes.
Conclusion: Our novel, interval-based approach is a valid and reliable method for quantifying differences between spikes at middle-distance
running intensit
Place-making in Edmonton’s Chinatown: Co-creating regenerative tourism opportunities
No full textBased in a western Canada, Edmonton’s Chinatown suffers from economic stagnation, high levels of socially depreciative behaviours associated with drug addiction and poor access to housing. Efforts to revitalize the neighborhood are underway; attention to recreation and tourism enhancement and strategic investment are part of this process. We will share our experiences as researchers involved place-making efforts to co-create a regenerative tourism strategy for the neighborhood's next 10 years. Our qualitative research workshop will share background about our case study site, methods used to collect data and engage in co-creative activities, and reflections on our struggles to maintain a place-making focus, while simultaneously navigating challenging relationships among community stakeholders. Our project employed walking interviews, focus groups, and mapping of tourism assets
Engaging Careholders in Regenerative Development: Aspirations and Concerns
No full textThe Colca Valley in Peru, known for its rich cultural, natural, and historical assets, is a significant tourism destination. This research explores regenerative tourism, a transformative framework that enhances ecological integrity, cultural heritage, and community well-being. Central to this approach is the co-creation process, integrating indigenous knowledge and systems thinking. The study introduces "careholders," community members with a moral and ethical responsibility for tourism development. The primary research question is: How do the people of the Colca Valley understand their tourism assets, and what are their aspirations for the future of tourism? The literature review highlights the dual impacts of tourism, emphasizing both benefits and challenges. It underscores the synergy between community-based tourism and participatory planning in advancing regenerative principles. Recent discussions emphasize engaging community members as essential for sustainable and regenerative tourism outcomes. This study aims to fill the gap in understanding local residents' perceptions of their tourism assets and aspirations. Using a qualitative methodology, semi-structured interviews with stakeholders in the Colca Valley will be conducted. Thematic analysis will identify recurring patterns and insights. Expected findings include diverse understandings of tourism assets, aspirations for cultural preservation, economic equity, and ecological sustainability, and concerns about over-tourism and exclusion from decision-making processes. These insights will inform strategies for aligning tourism development in the Colca Valley with regenerative principles
Exploring the Appeal of the Business Events Profession to Future Workforce
No full textThis study examines global perceptions of the business events profession, focusing on its appeal to the future workforce. Utilizing survey responses from 217 individuals aged 18–35, the analysis identifies three key perception factors: professional appeal, job insecurity and stress, and career perks. Regional comparisons reveal that North American respondents rate the profession’s positive attributes significantly higher than their European counterparts. Textual analysis of the open-ended responses highlights both limited public knowledge about the field and positive sentiments tied to its dynamic nature and professional traits. Findings underscore the importance of targeted communication strategies to attract young talent and address regional and perception-based challenges