Experimental Recreation of the Sub-Glacial System, an Analysis of Hold Time versus Strengthening to Shed Light on the Mechanics of Stick-Slip Ice Streams

Ice streams in Antarctica are known to move ice rapidly, in a narrow band, over a loose permeable substrate to the sea- contributing to sea-level rise and the decay of the Antarctic Ice Sheet. It has been observed that some of these ice streams move in a “stick-slip” fashion, lurching ahead small steps at a time. Past workers have proposed this observation is indicative of temporal strengthening in the ice stream when it’s sitting at rest, but have not satisfactorily concluded which components of the glacial system are directly causing the strengthening. To understand the mechanics dictating ice stream motion, and in turn put better constraints on predictions regarding the continued decay of the Antarctic Ice Sheet, we have resorted to experimentally recreating the sub-glacial system in the lab, in two “ringshear” devices designed by Dr. Iverson at Iowa State University. Two main questions we wanted answered were: (A) “Do we observe a significant relationship between hold time and strengthening?” and (B) “Which component(s) (ice, water, and sediment) contribute to the strengthening, and by how much does each contribute?” To do this we ran a suite of “slide-hold-slide” experiments, in each case adding one more component of the glacial system, where time held still (corresponding to the “stick” phase of motion), was measured against the maximum strength the material achieved upon forcing it to undergo further shear (corresponding to the “slip” phase of motion). Our results indicate that there is indeed a significant relationship between hold times and strengthening, and that all three components (ice, water, sediment) contribute to strengthening- however, with each component contributing differently depending on how long of a hold time they have undergone. These results are in agreement with first order physical principles, but further work is required to develop the mathematical relationships relating strengthening to hold time for each component of the system

Use of accelerometry to investigate physical activity in dogs receiving chemotherapy

Objectives: To perform a preliminary study to assess whether single-agent palliative or adjuvant chemotherapy has an impact on objectively measured physical activity in dogs. Methods: Fifteen dogs with neoplasia (treatment group) wore ActiGraph™ accelerometers for 5-day periods before, during and after receiving single-agent adjuvant or palliative chemotherapy. Mean 5-day total physical activity and time spent in three different intensities of activity (sedentary, light-moderate and vigorous) before, during and after receiving chemotherapy were compared to a group of 15 healthy dogs (control group). Results were also compared within the treatment group across time. Results: Prior to chemotherapy, treated dogs tended to be less active than control dogs. Treatment group dogs were slightly more active at restaging than they were prior to treatment but had similar activity levels to control dogs. Marked effects of chemotherapy on physical activity were not detected. Physical activity was slightly lower in treated dogs during chemotherapy when compared to control dogs but there was a slight increase in physical activity of treated dogs during chemotherapy when compared with pretreatment recordings. There was little change in the mean 5-day total physical activity between treated dogs during chemotherapy and at restaging but a mild decrease in time spent sedentary and increase in time spent in light-moderate activity at this comparison of time points. Clinical Significance: Single-agent adjuvant or palliative chemotherapy had minimal impact on physical activity levels in dogs with neoplasia

Earthquake Arrival Association with Backprojection and Graph Theory

The association of seismic wave arrivals with causative earthquakes becomes progressively more challenging as arrival detection methods become more sensitive, and particularly when earthquake rates are high. For instance, seismic waves arriving across a monitoring network from several sources may overlap in time, false arrivals may be detected, and some arrivals may be of unknown phase (e.g., P- or S-waves). We propose an automated method to associate arrivals with earthquake sources and obtain source locations applicable to such situations. To do so we use a pattern detection metric based on the principle of backprojection to reveal candidate sources, followed by graph-theory-based clustering and an integer linear optimization routine to associate arrivals with the minimum number of sources necessary to explain the data. This method solves for all sources and phase assignments simultaneously, rather than in a sequential greedy procedure as is common in other association routines. We demonstrate our method on both synthetic and real data from the Integrated Plate Boundary Observatory Chile (IPOC) seismic network of northern Chile. For the synthetic tests we report results for cases with varying complexity, including rates of 500 earthquakes/day and 500 false arrivals/station/day, for which we measure true positive detection accuracy of > 95%. For the real data we develop a new catalog between January 1, 2010 - December 31, 2017 containing 817,548 earthquakes, with detection rates on average 279 earthquakes/day, and a magnitude-of-completion of ~M1.8. A subset of detections are identified as sources related to quarry and industrial site activity, and we also detect thousands of foreshocks and aftershocks of the April 1, 2014 Mw 8.2 Iquique earthquake. During the highest rates of aftershock activity, > 600 earthquakes/day are detected in the vicinity of the Iquique earthquake rupture zone

Intending the Worst: The Case of ISIS’s Specific Intent to Destroy the Christians of Iraq

Genocide has been called the “crime of crimes.” That superlative is well-stated. Genocide is the intentional destruction of an entire people—a worse crime is almost beyond comprehension. The very word conjures some of the most horrific images in recorded history. And yet our legal understanding of this most-important crime is limited. Because the crime of genocide requires specific intent, even horrific atrocities will not qualify as genocide as a matter of law if done for a purpose other than the intended destruction of a target group. Thus whether actions qualify as genocide and what type of evidence is sufficient to establish genocide is widely debated. The question of genocide and specific intent has prompted decades of debate within the academic literature. For example, scholars debate whether the “purpose-based” or the knowledge-based” approach is best for determining if specific intent exists. Yet despite dozens of articles and books on the subject, there are so few agreed-upon actual cases of genocide that resolving academic debates or understanding what constitutes specific intent is difficult. Scholars predominately extrapolate from decisions made by international tribunals such as those established to prosecute the perpetrators of the Bosnian and Rwandan genocides. But even those decisions are limited to the actions of individuals. The nations of the world, including the United States, failed to declare that genocide was happening at the time of the Bosnian and Rwandan genocides. So what actions by a political organization constitute specific intent sufficient for the nations of the world to declare that an ongoing genocide is taking place? On March 17, 2016 Secretary of State John Kerry issued a declaration that ISIS was committing genocide against certain minority groups in Iraq. This was only the second such declaration of genocide during an ongoing conflict in history. Secretary Kerry’s declaration thus serves as an exceptionally rare precedent by which certain academic debates can be resolved. This Article seeks to answer what constitutes specific intent to commit genocide by thoroughly examining the evidence and arguments presented to Secretary Kerry related to the Christians of Iraq. The Article provides an overview of the academic debate regarding specific intent, details the evidence against ISIS that was presented to Secretary Kerry, and looks at the specific legal arguments that were raised to show that ISIS had the requisite specific intent. The article concludes by extrapolating what evidence and arguments may have been persuasive to secure the declaration. In doing so, the Article seeks to provide authoritative on the crucially important question of what is necessary to show specific intent and to determine that genocide is taking place

Paper Session III-A - Closed Loop Systems

National Aeronautics and Space Administration (NASA) is unique in its search for man made, closed loop life support systems and in its total engineering methods. Short term space travel has given NASA tremendous knowledge in closed loop systems and the vision of extended space travel will require the expansion of this knowledge base. Earth and its surrounding atmosphere has been operating as a closed loop life support system for billions of years. It has gone through many changes to best suit an equilibrium state. In recent years, man has developed to a level where we can effect that state. With this in mind, the task of protecting our life support system on earth and designing the systems for long duration space travel have great communality

Legal, ethical & social issues in the case of an intrusive remote monitoring software

In 2008, a laptop was stolen from a high school student in the USA. The laptop was being monitored by remote recovery software. The thief sold the laptop in question to another student who in turn sold it to a teacher. The software continued to monitor the private daily life of this teacher. This paper provides an overview of the resultant lawsuit. We examine the ethical, privacy and legal dilemmas highlighted by this case

Narrow Linewidth DFB Lasers for Cold Atom Technologies

No abstract available