Improving the Implementation of International Development Law: Replacing the SDGs with INDCs

Article published in the Michigan State University School of Law Student Scholarship Collection

Global Goal-Setting: How the Current Development Goal Model Undermines International Development Law

Article published in the Michigan State International Law Review

Acute Large-Vessel Occlusion Masquerading as Traumatic Injury

A patient presented to an urban level 1 trauma center/accredited thrombectomy-capable stroke center for evaluation of suspected traumatic injury and was quickly determined to have symptoms suspicious for acute stroke that included dense hemiparesis with preserved mental status. He received a thrombectomy with an eventual return to neurologic baseline and discharge to acute inpatient rehabilitation 14 days after presentation

Physical Ageing of the Contact Line on Colloidal Particles at Liquid Interfaces

Young's law predicts that a colloidal sphere in equilibrium with a liquid interface will straddle the two fluids, its height above the interface defined by an equilibrium contact angle. This equilibrium analysis has been used to explain why colloids often bind to liquid interfaces, an effect first observed a century ago by Ramsden and Pickering and later exploited in a wide range of material processes, including emulsification, water purification, mineral recovery, encapsulation, and the making of nanostructured materials. But little is known about the dynamics of binding. Here we show that the adsorption of polystyrene microspheres to a water-oil interface is characterized by a sudden breach and an unexpectedly slow relaxation. Particles do not reach equilibrium even after 100 seconds, and the relaxation appears logarithmic in time, suggesting that complete equilibration may take months. Surprisingly, viscous dissipation appears to play little role. Instead, the observed dynamics, which bear strong resemblance to aging in glassy systems, agree well with a model describing activated hopping of the contact line over nanoscale surface heterogeneities. These results may provide clues to longstanding questions on colloidal interactions at an interface.Engineering and Applied SciencesPhysic

Visualizing the turbulent energy cascade: Fourier and physical space

The transfer of kinetic energy from large to small scales is a hallmark of turbulent fluids. While it is generally well understood in a statistical sense, a mechanistic understanding of the exact processes is still lacking. In this manuscript, we filter the velocity field in bands of wavenumbers distributed logarithmically to investigate the transfer of energy in Fourier space, an approach which also provides a way of visualizing the energy cascade in real space. We use this method to study how energy is transferred to small scales in different flow configurations. In the case of a statistically steady homogeneous isotropic turbulent flow at moderate Reynolds numbers, we demonstrate that the transfer between bands of wavenumbers is well described by a phenomenological model originally proposed by Tennekes & Lumley (1972). We then apply this method to investigate the formation of small scales during the interaction between two vortex tubes and show that the transfer of energy in these problems correlates with the dynamics of vorticity formation at ever decreasing scales. This enticing correlation between vortices and energy transfer, however, does not fully capture the transfer of energy in a structureless homogeneous isotropic turbulent flow, where strain also plays an important role

Change, Choice, and Commercialization: Backpacker Routes in Southeast Asia

South-East Asia has the oldest and largest backpacker trails. This paper examines the geographies of such flows, drawing upon the largest survey to date of backpackers in Asia using qualitative research to survey the key changes from the 1970s to the 2000s. Backpacker trails have changed significantly and new routes have emerged including the ‘northern trail’ (Bangkok - Cambodia - Vietnam - Laos). It is to be expected that routes change as backpackers constantly seek new places, pioneering for later mass tourism. However, this paper suggests that using institutionalization as a framework, these changing trails and backpacker ‘choices’ can be seen as driven by growing commercialization and institutionalization. This then operates in combination with external variables (travel innovations - low cost airlines, and new transport networks); exogenous shock (political instability, terrorism); and growing regional competition from emerging destinations such as Vietnam and Cambodia

A synthesis of automated planning and reinforcement learning for efficient, robust decision-making

Automated planning and reinforcement learning are characterized by complementary views on decision making: the former relies on previous knowledge and computation, while the latter on interaction with the world, and experience. Planning allows robots to carry out different tasks in the same domain, without the need to acquire knowledge about each one of them, but relies strongly on the accuracy of the model. Reinforcement learning, on the other hand, does not require previous knowledge, and allows robots to robustly adapt to the environment, but often necessitates an infeasible amount of experience. We present Domain Approximation for Reinforcement LearnING (DARLING), a method that takes advantage of planning to constrain the behavior of the agent to reasonable choices, and of reinforcement learning to adapt to the environment, and increase the reliability of the decision making process. We demonstrate the effectiveness of the proposed method on a service robot, carrying out a variety of tasks in an office building. We find that when the robot makes decisions by planning alone on a given model it often fails, and when it makes decisions by reinforcement learning alone it often cannot complete its tasks in a reasonable amount of time. When employing DARLING, even when seeded with the same model that was used for planning alone, however, the robot can quickly learn a behavior to carry out all the tasks, improves over time, and adapts to the environment as it changes