Computer-mediated collaboration and the transitioning of intercultural spaces

The following implementation of computer-mediated collaboration\ud aims to help international students improve the quality of their intercultural experiences by applying strategies for synthesizing and applying knowledge obtained\ud through cross-cultural interactions. It does this by engaging learners in computermediated collaborative activities that help increase their factual knowledge in\ud areas of individual relevance, develop personally effective retrieval and application frameworks and improve their ability to monitor their own thinking and\ud learning

Calculation of Damping Rates in Thin Inhomogeneous Ferromagnetic Films Due to Coupling to Lattice Vibrations

This article describes calculations of ferromagnetic resonance damping rates due to coupling between the magnetization and lattice vibrations through inhomogeneities. The mechanisms we have explored include generation of shear phonons through inhomogeneous anisotropy and generation of both longitudinal and shear phonons through inhomogeneous magnetostriction. In both cases, inhomogeneities couple the uniform precession to finite wave vector phonons. For both coupling mechanisms, the predicted damping rate is on the order of 106 s-21 in transition metals. The damping rate by these mechanisms is inversely proportional to the fifth power of the shear phonon velocity, and may play a significant role in mechanically softer materials such as magnet/polymer nanocomposites

Locking and Tracking Magnetic Resonance Spectra of NV- Center for Real-time Magnetometry using a Differential Photon-Rate Meter

We describe a real-time data processing and frequency control method to track peaks in optically detected magnetic resonance of nitrogen-vacancy centers in diamond. This procedure allows us to measure magnetic field continuously with sensitivity ~6 uT/Hz^{1/2} and to track resonances at sweep rates exceeding 110 uT/s. We use a custom-built differential photon rate meter and active feedback control to "lock" the microwave excitation frequency of the magnetic resonance. Our scheme covers a broad magnetic field range, limited by the frequency range of the microwave generator. This measurement procedure automates the processing of voltage pulse outputs from the photon counters, and it provides sensitivity comparable to traditional photon counting method

The Effect of Player Performance on Free Agency Contract Value in Major League Baseball

This study estimates the effect of player performance on free agency contract values in Major League Baseball (MLB). We hypothesize that performance, as measured by Wins Above Replacement (WAR), has a positive effect on the contract value. To test this, we specify and estimate a linear regression for contract value as a function of current and lagged WAR values and other control variables. Using data from 82 major league position players during the 2013 and 2014 seasons, our results indicate that the current and lagged values of WAR have a significant, positive effect on contract value. Among the control variables, the contract length has a significant, positive effect on the contract value. The model is used to predict free agent contract values set during the 2015 off-season. This prediction for 25 players has an average error of 35%, without systematic over-or under-prediction

Localized Ferromagnetic Resonance in Inhomogeneous Thin Films

The effect of sample inhomogeneity on the ferromagnetic resonance linewidth is determined by diagonalization of a spin wave Hamiltonian for ferromagnetic thin films with inhomogeneities spanning a wide range of characteristic length scales. A model inhomogeneity is used that consist of size D grains and an anisotropy field Hp that varies randomly from grain to grain in a film with thickness d and magnetization Ms. The resulting linewidth agrees well with the two-magnon model for small inhomogeneity, HpD « πMsd. For large inhomogeneity, HpD » πMsd the precession becomes localized and the spectrum approaches that of local precession on independent grains

Normal Mode Mixing and Ferromagnetic Resonance Linewidth

The normal modes of an inhomogeneous thin film are obtained by diagonalization of the perturbed Hamiltonian. The resulting modes are mixtures of the spin-wave modes and the uniform mode. We find that the ferromagnetic resonance intensity spectrum of the diagonalized system has a Lorentzian profile, and that the results correspond to the two-magnon model for weak perturbations. For stronger perturbations, the density of states is smoothed, and the spectrum becomes asymmetric due to the low-frequency cutoff of the spin-wave manifold. The technique is expected to be valid for perturbation amplitudes that are large enough to invalidate the assumptions of the two-magnon model

Eigen Modes and Ferromagnetic Resonance Line Width of Inhomogeneous Thin Films

In this paper, we describe modeling of the effects of magnetic inhomogeneity on ferromagnetic resonance line width using eigen mode analyses of inhomogeneous thin magnetic films

Geospatial modeling approach to monument construction using Michigan from A.D. 1000–1600 as a case study

Building monuments was one way that past societies reconfigured their landscapes in response to shifting social and ecological factors. Understanding the connections between those factors and monument construction is critical, especially when multiple types of monuments were constructed across the same landscape. Geospatial technologies enable past cultural activities and environmental variables to be examined together at large scales. Many geospatial modeling approaches, however, are not designed for presence-only (occurrence) data, which can be limiting given that many archaeological site records are presence only. We use maximum entropy modeling (MaxEnt), which works with presence-only data, to predict the distribution of monuments across large landscapes, and we analyze MaxEnt output to quantify the contributions of spatioenvironmental variables to predicted distributions. We apply our approach to co-occurring Late Precontact (ca. A.D. 1000–1600) monuments in Michigan: (i) mounds and (ii) earthwork enclosures. Many of these features have been destroyed by modern development, and therefore, we conducted archival research to develop our monument occurrence database. We modeled each monument type separately using the same input variables. Analyzing variable contribution to MaxEnt output, we show that mound and enclosure landscape suitability was driven by contrasting variables. Proximity to inland lakes was key to mound placement, and proximity to rivers was key to sacred enclosures. This juxtaposition suggests that mounds met local needs for resource procurement success, whereas enclosures filled broader regional needs for intergroup exchange and shared ritual. Our study shows how MaxEnt can be used to develop sophisticated models of past cultural processes, including monument building, with imperfect, limited, presence-only data

Tropomyosin 4 Regulates Osteoclast Function through Actin Adhesion Structures

Biological Sciences: 1st Place (The Ohio State University Edward F. Hayes Graduate Research Forum)Osteoclasts, large, multinucleated cells which resorb bone, function to maintain bone degradation vital for maintenance and repair of bone tissue. Osteoclasts function by forming unique actin structures for migration, podosomes, and bone resorption, actin rings. The actin cytoskeleton also transports V-ATPases to the plasma membrane. Thus regulation of actin is central to the understanding osteoclast function. Tropomyosins are proteins that bind to actin and regulate other proteins association with actin. The purpose of this study is to investigate the role of tropomyosins, specifically tropomyosin 4, in osteoclasts. Our research initially demonstrated the presence of eight tropomyosins in osteoclasts. Confocal imaging demonstrated that the eight tropomyosins were distributed in distinct locations. Of these eight tropomyosins, tropomyosin 4 colocalized with the interior faces of both actin rings and podosomes. To investigate the role of tropomyosin 4 expression was suppressed by RNA interference. The suppression led to reductions in actin ring thickness, bone resorption, and motility. Suppression also led to improper V-ATPase trafficking which was not due to a decrease in expression or complex formation. In addition, we produced stable cell lines that overexpressed tropomyosin 4. Overexpression resulted in abnormal podosomes that were thicker than normal and unusually distributed along with reduced cell motility. Further, actin ring formation was disrupted and bone resorption was abolished. Together the studies suggest that tropomyosin 4 regulates the adhesion structures of osteoclasts by stabilizing the actin in podosomes and actin rings and thus affecting osteoclast migration and resorption.No embarg