Metastable states as a key to the dynamics of supercooled liquids

Computer simulations of a model glass-forming system are presented, which are particularly sensitive to the correlation between the dynamics and the topography of the potential energy landscape. This analysis clearly reveals that in the supercooled regime the dynamics is strongly influenced by the presence of deep valleys in the energy landscape, corresponding to long-lived metastable amorphous states. We explicitly relate non-exponential relaxation effects and dynamic heterogeneities to these metastable states and thus to the specific topography of the energy landscape

Satellite animal tracking feasibility studies

A study was initiated in Tsavo National Park to determine movements and home ranges of individual elephants and their relations to overall distribution patterns and environmental factors such as rainfall. Methods used were radio tracking and observations of visually identifiable individuals. Aerial counts provided data on overall distribution. Two bulls and two cows were radio-tagged in Tsavo West and two bulls and four cows in Tsavo East, providing home range and movement data. The movements of individuals were useful in interpreting relatively major shifts in elephant distribution. Results point to the following preliminary conclusions: (1) elephants in the Tsavo area undertook long distance movements in fairly direct response to localized rainfall; (2) a subdivision of the overall population into locally distinct units may exist during the dry season but did not occur after significant rainfall; and (3) food appears to be the primary factor governing movements and distribution of elephants in the area

Satellite (IRLS) tracking of elk

The practicability of tracking free roaming animals in natural environments by satellite systems is reported. Satellite systems combine continuous tracking with simultaneous monitoring of physiological and environmental parameters through a combination of radio tracking and biotelemetric ground systems that lead to a better understanding of animal behavior and migration patterns

Evolution of Relative Magnetic Helicity: New Boundary Conditions for the Vector Potential

We recently proposed a method to calculate the relative magnetic helicity in a finite volume for a given magnetic field which however required the flux to be balanced separately on all the sides of the considered volume. In order to allow finite magnetic fluxes through the boundaries, a Coulomb gauge is constructed that allows for global magnetic flux balance. We tested and verified our method in a theoretical fore-free magnetic field model. We apply the new method to the former calculation data and found a difference of less than 1.2\%. We also applied our method to the magnetic field above active region NOAA 11429 obtained by a new photospheric-data-driven MHD model code GOEMHD3. We analyzed the magnetic helicity evolution in the solar corona using our new method. It was found that the normalized magnetic helicityis equal to -0.038 when fast magnetic reconnection is triggered. This value is comparable to the previous value (-0.029) in the MHD simulations when magnetic reconnection happened and the observed normalized magnetic helicity (-0.036) from the eruption of newly emerging active regions. We found that only 8\% of the accumulated magnetic helicity is dissipated after it is injected through the bottom boundary. This is in accordance with the Woltjer conjecture. Only 2\% of magnetic helicity injected from the bottom boundary escapes through the corona. This is consistent with the observation of magnetic clouds, which could take away magnetic helicity into the interplanetary space, in the case considered here, several halo CMEs and two X-class solar flares origin from this active region.Comment: Accepted to be pulished on A&

Revisiting and modeling the magnetism of hole-doped CuO_2 spin chains in Sr{14-x}Ca_xCu_{24}O_{41}

Magnetization measurements of Sr{14-x}Ca_xCu_{24}O_{41} with 0 <= x <=12 in magnetic fields up to 16 T show that the low-temperature magnetic response of the CuO_2 spin chains changes strongly upon Ca doping. For x=0 quantum statistical simulations yield that the temperature and field dependence of the magnetization can be well described by an effective Heisenberg model in which the ground state configuration is composed of spin dimers, trimers, and monomers. For x>0 a constant contribution to the low-temperature magnetic susceptibility is observed which cannot be explained in terms of simple chain models. Alternative scenarios are outlined.Comment: 2 pages, submitted to the proceedings of the ICM, Kyoto, Japan, August 200

In Restless Character: A Short Story and Writing Analysis

Creativity is the process of making something new. For those who desire to use their creativity, this process is discouraging because so many things have already been created. Originality becomes a battle to find a subject that remains untouched. However, Salman Rushdie, author of the1981 Booker Prize-winning novel Midnight\u27s Children, gives a theory for how newness enters the world as written in his 1992 essay Imaginary Homelands. In this essay, he explores the negative and positive consequences resulting from the co-mingling of cultures, and he comes to the conclusion that the merging of two or more things unalike will bring forth something undone before, though the pieces previously existed without co-habitation. When these pieces rest upon one object or person, they have inadvertently created something new out of old things. This is how newness enters the world. For the field of English, creativity means combining pre-existing ideas and experiences into one project and creating an original piece of writing. In order for writers to advance in their field, they must understand basic techniques in the mechanics of writing, some struggles that they may face, and how to succeed in the publishing arena. Unlike other fields, the technique of writers rests on creating a work of art without easy access to sensory tools. Artists appeal to sight, musicians appeal to sound, chefs appeal to taste and smell, clothing designers appeal to touch and sight, etc. Writers must show readers their creation using concrete details to evoke sensory recognition and refrain from simply telling readers the story through vague descriptions. In her guide to narrative craft, Janet Burroway writes that Your job as a fiction writer is to focu

Creating an Experiential and Values-Based Classroom

In my project, I will present strategies to create an engaging and experiential environment where students are co-creators of value in the course. I will share how to incorporate Xavier’s Mission into the student learning and the classroom environment by discussing how to create pedagogy that links Bloom’s Taxonomy to Xavier’s Jesuit Values. Additionally, I will discuss strategies to facilitate experiential learning and solicit student feedback. These include tactics related to formal and informal feedback, ungraded assignments, team-based projects, and classroom discussions. Collectively, this project highlights the importance of creating a comfortable learning environment in which students increase their knowledge through the process of “learn-do-teach”; students learn through lecture and discussion, do through in-class assignments, assessments, and activities, and teach by sharing their knowledge—with their peers and professional partners—on team-based experiential learning projects

Ising magnets with mobile defects

Motivated by recent experiments on cuprates with low-dimensional magnetic interactions, a new class of two-dimensional Ising models with short-range interactions and mobile defects is introduced and studied. The non-magnetic defects form lines, which, as temperature increases, first meander and then become unstable. Using Monte Carlo simulations and analytical low- and high-temperature considerations, the instability of the defect stripes is monitored for various microscopic and thermodynamic quantities in detail for a minimal model, assuming some of the couplings to be indefinitely strong. The robustness of the findings against weakening the interactions is discussed as well

Purpose and Order

In the study of religion there is major emphasis put on how religion works and what religion is, but less emphasis on why religion exists at all. I use the work of Emile Durkheim and several examples to explain my own ideas on why religion exists. I theorize that religion is a survival tool for human beings to find order and meaning in the complex and chaotic environment we inhabit. Durkheim also believes religion brings order and meaning to humans. I argue that as humans progress, we are able to find order and meaning without conventional religion. Durkheim believes that in totem religion, order comes through belief in the sacred. I agree, but believe the sacred only brings order through creating an absolute. The same type of absolute can be seen in the foundation of every major religious system. An example of an absolute in Buddhism is the four noble truths. They explain the chaos in the world to be due to karma. Belief in this absolute is no different than belief in the sacred because they are both tools to create a sense of order. Physics explains that the world has order in the same way Buddhism does. The speed of light is a mathematical constant, an absolute through which seemingly random events can be explained. The four noble truths and the speed of light are both absolutes that lead to understanding the complex world we live in. People still need order, but now have options that are not belief-oriented. My theory connects with Durkheim’s but also explains that people are finding new systems to create order and meaning in their lives. Although these new systems have the same core ideas, do they bring the same fulfillment as conventional religion

Gait Intervention for Improvements in Human Top Speed Running

Between individuals faster sprinting speeds are achieved by applying greater stance average forces against the running surface. Recent evidence further indicates that elite level performers also strike the ground with leg kinematics that differ from those of non-elites and that these leg movements act to enhance the force transients occurring in the milliseconds following foot-ground impact. I investigated whether sprint performance could be enhanced through a short term gait intervention, consisting of 3 laboratory training sessions wherein subjects (n = 6) completed 5 high-speed runs on an instrumented force treadmill at 90% of their measured top sprint. The subjects received immediate visual feedback of the previous bout of sprinting by reviewing the video record obtained from a laterally positioned camera with a frame rate of 1000 Hz. The subjects also received verbal cues throughout their participation, which were focused on encouraging leg postures more suitable for applying greater vertical forces into the ground. Incremental tests to top speed were administered on the force treadmill prior to and following the gait intervention. Paired sample t-tests were used to analyze the pre- vs. post-intervention variables which included; ground contact time, aerial time, swing time, stride time, and step length. Following the gait intervention top speeds increased by 6.7% [SD 1.3] and ground reaction forces increased by 0.03 xWb. 3D video analysis revealed that the velocity of the ankle and foot immediately before touchdown also increased by 7.3%. This permitted the leg to use a posture better able to apply the high vertical forces needed in the first half of stance. These data indicate that an acute training intervention can augment sprinting performance within a time frame that is too brief for the improvement to be attributed to changes within the musculature of the individual subjects. I conclude that running speed can be taught by providing knowledgeable cues that focus on the mechanics of the foot-ground impact