Methane Beneath Greenlands Ice Sheet Is Being Released

Methane is a potent greenhouse gas, but a complete accounting of global methane sources and sinks is still ongoing. Sediments beneath glaciers and ice sheets harbour carbon reserves that, under certain conditions, can be converted to methane. However, the formation and release of such methane is an unquantified component of the arctic methane budget. Lamarche-Gagnon et al. present direct measurements of dissolved methane in proglacial discharge from a land-terminating glacier of the Greenland Ice Sheet. This proglacial discharge was supersaturated with methane and had diffusive methane fluxes similar to other terrestrial rivers for the duration of the summer measurement period. Their results suggest that variability in proglacial discharge is associated with methane release from subglacial environments, implicating both the form and evolution of the subglacial hydrologic system as a newly discovered control in the arctic methane cycle.The study by Lamarche-Gagnon et al. is an important example of how the cryosphere can interact with the surrounding Earth system in unexpected and potentially significant ways. Characterizing the ability of subglacial sediments to convert and store methane and the ability of the subglacial hydrologic system to export this methane to the atmosphere, through both modeling and observational studies, are critical steps in improving our knowledge of the sources and sinks of arctic methane and better constraining their future changes

Parents and teachers need to step up for young girls with ADHD

Many young girls are charging headlong into stressful academic environments without knowing they have a learning or behavioral disorder such as attention-deficit hyperactivity disorder (ADHD). This lack of critical awareness of their mind’s wiring leaves many girls trudging through their academic careers convinced they’re lazy, irresponsible or too incompetent for their field

Spatial Mismatch for Low-Wage Workers in post-Katrina New Orleans

The theme of this study is spatial mismatch, a concept that gave rise to an ever-expanding body of research concerned with how and why residential and employment distributions have shifted within cities and across metropolitan areas. The concept grew out of John F. Kain\u27s research on how racial discrimination and segregation affects the spatial patterns of people/subgroups and jobs in the postwar American urban environment. Specifically, Housing Segregation posits that housing-market discrimination is at the root of increased unemployment among inner-city, nonwhite workers; concurrently, the pace and volume of decentralization (of residents and employment) from central-cities reinforces low-income, overwhelmingly African-American isolation and immobility. This study contributes to the New Orleans literature by providing a pre- and post-Katrina snapshot of spatial mismatch. The analysis addresses research questions aimed at gauging the extent to which mismatch and job-isolation have changed for poor workers in the New Orleans metro area since Hurricane Katrina

Going Postal: What Can Reform do for You?

The sending and receiving of post and parcel is a vital aspect of daily living in the United States. Despite this vitality, the setup for post and parcel delivery in the United States has been heavily criticized. This Note, in response to these criticisms, explores whether postal reform is warranted in the United States today. To do so, this Note examines the origins of the public/private dichotomy inherent in the delivery of post and parcel, governmental regulation of the United States Postal Service and its private competitors, and the monopolies possessed by the United States Postal Service. It then analyzes the advantages and disadvantages of the current regime from the perspective of the United States Postal Service’s private-sector competitors and consumers. Ultimately, this Note concludes that postal reform is necessary and proposes avenues for such reform

Meltwater Routing in GEOS: Current Activities and Plans

No abstract availabl

The Crystallisation of Pharmaceuticals Using Tailored Supramolecular Gels

Due to ever increasing pressure for pharmaceutical companies to characterise and patent the polymorph landscape of new APIs, it is important that as many forms as possible are identified in the early stages of drug development. Novel polymorph screening techniques are required to expand the scope of traditional solution-phase methods, and access highly metastable or difficult to nucleate solid forms. This work exemplifies a modern polymorph screen, using a wide variety of experimental and computational methods to comprehensively characterise the polymorph landscape of mexiletine hydrochloride. Instead of the six forms described in previous literature, this screen revealed seven: an enantiotropic pair of anhydrous polymorphs that are stable at different temperatures, one anhydrous metastable form, three families of isostructural channel solvates, and a fourth solvate of unknown structure. Two new channel solvates, and new routes to three known forms were discovered by crystallising mexiletine within drug-mimetic supramolecular gels. As gelation was often turned off when a new polymorph crystallised within the gel, these changes in solid form are likely driven by strong interactions between the drug and gelator. The crystallisation of high temperature stable Form 2 from a gel at room temperature is a particularly striking example of the powerful stabilising effect of these tailored supramolecular gels. A complementary study into the gel-phase crystallisation of diatrizoic acid showed that the drug followed the same two-step crystallisation regime as the gelator, leading to the formation of two novel drug-gelator salt solvates. These results suggest that the polymorph landscape of the gelator has influenced the drug crystallisation, which may provide a new avenue of inquiry for the design of supramolecular gelators for pharmaceutical crystallisation. From this work, it is clear that supramolecular gels are a valuable tool for pharmaceutical polymorph screening

Space for Two to Think: Large, High-Resolution Displays for Co-located Collaborative Sensemaking

Large, high-resolution displays carry the potential to enhance single display groupware collaborative sensemaking for intelligence analysis tasks by providing space for common ground to develop, but it is up to the visual analytics tools to utilize this space effectively. In an exploratory study, we compared two tools (Jigsaw and a document viewer), which were adapted to support multiple input devices, to observe how the large display space was used in establishing and maintaining common ground during an intelligence analysis scenario using 50 textual documents. We discuss the spatial strategies employed by the pairs of participants, which were largely dependent on tool type (data-centric or function-centric), as well as how different visual analytics tools used collaboratively on large, high-resolution displays impact common ground in both process and solution. Using these findings, we suggest design considerations to enable future co-located collaborative sensemaking tools to take advantage of the benefits of collaborating on large, high-resolution displays

Physically Based and Stochastic Models for Greenland Moulin Formation, Longevity, and Spatial Distribution

Nearly all proglacial water discharge from the Greenland Ice Sheet is routed englacially, from the surface to the bed, via moulins. Identification of moulins in high-resolution imagery is a frequent topic of study, but the processes controlling how and where moulins form remain poorly understood. We seek to leverage information gained from the development of a physical model of moulin formation, remotely sensed ice-sheet data products, and an analytic model of ice-flow perturbations to develop a predictive stochastic model of moulin distribution across Greenland. Here we present initial results from the physical model of moulin formation and characterize the sensitivity of moulin geometry to a range of model parameters. This parameterization of moulin formation is the first step in developing a stochastic model that will be a predictive, computationally efficient representation of the englacial hydrologic system

A Physical Model of Moulin Formation and Evolution

Nearly all proglacial water discharge from the present-day Greenland Ice Sheet is routed englacially via moulins. Identification of these moulins in high-resolution imagery is a frequent topic of study, but the processes controlling how and where moulins form, including on past ice sheets for which remote-sensing data are not available, remain poorly understood. Because moulins may reasonably compose approximately 10-15% of the englacial-subglacial hydrologic system, the evolution and shape of moulins can alter the timing of meltwater inputs to the bed. This evolution can impact both the form of the subglacial hydrologic system and the structure of associated geomorphological structures. Here, we develop a physical model of moulin formation and evolution to constrain the role of englacial processes in controlling the form and structure of the subglacial hydrologic system. Ice deformation within and around a moulin is both viscous and elastic, with the rate of turbulent and heat dissipation from water circulation in the moulin controlling both moulin wall melting and warming of the surrounding ice. We find moulin geometry is responsive to changes in these parameters over hours to days, indicating that diurnal and multi-day variations in surface melt can substantially alter the geometry of a moulin and the pressure-discharge relationship at the bed of the ice sheet. These results should be considered carefully when determining surface water inputs for subglacial hydrologic models. In the future, a parameter space study of these results will be combined with an analytic model to create a predictive, stochastic model of moulin and crevasse locations. This future model will be applicable to constraining the potential for surface-to-bed connections in regions where the exact ice-sheet surface morphology is not known, including ice sheets under future warming atmospheric conditions, and paleo ice sheets, where moulins created modern landforms