Investigation of the Role of Elastic Unitarity in High-Energy Scattering: Gribov's Theorem and the Froissart Bound

We re-examine V. Gribov's theorem of 1960 according to which the total cross-section cannot approach a finite non-zero limit with, at the same time, a diffraction peak having a finite slope. We are very close to proving by an explicit counter-example that elastic unitarity in the elastic region is an essential ingredient of the proof. By analogy, we raise the question of the saturation of the Froissart-Martin bound, for which no examples incorporating elastic unitarity exist at the present time.Comment: 11 pages, 1 figures, latex with sproc.st

On near-cloaking for linear elasticity

We make precise some results on the cloaking of displacement fields in linear elasticity. In the spirit of transformation media theory, the transformed governing equations in Cosserat and Willis frameworks are shown to be equivalent to certain high contrast small defect problems for the usual Navier equations. We discuss near-cloaking for elasticity systems via a regularized transform and perform numerical experiments to illustrate our near-cloaking results. We also study the sharpness of the estimates from [H. Ammari, H. Kang, K. Kim and H. Lee, J. Diff. Eq. 254, 4446-4464 (2013)], wherein the convergence of the solutions to the transmission problems is investigated, when the Lam\'e parameters in the inclusion tend to extreme values. Both soft and hard inclusion limits are studied and we also touch upon the finite frequency case. Finally, we propose an approximate isotropic cloak algorithm for a symmetrized Cosserat cloak.Comment: 7 figures, 7 tables; Note that the earlier version of this preprint was titled 'Some results in near-cloaking for elasticity systems'. This new version of the manuscript has also seen some major upgrade. We have added a new section on 'Cloaking parameters and isotropic approximation'. In there, we propose an approximate isotropic cloak algorithm for a symmetrized Cosserat cloa

PEMBUATAN BOARD GAME UNITE AND FIGHT

cooperation is an important aspect that need to be taught as soon as possible, especially to teenager which is an important phase of individuality shaping. One of the example of such activity is outbound, but outbound is difficulties to be prepared, thus a convenient media to introduce the importance of cooperation is made in the form of board game with unique point in how to win the game. After that, board game with similar mechanic and companion app analyzed. The result then used to design the board game and companion app. The design of board game and companion app then made using adobe photoshop CS6 and unity. The board game made with cooperative play, action point allowance, variable phase order, programmed movement, dice rolling and grid movement mechanic. After made then the board game tested by doing blind test play with 10 people, after that each participant will be asked to fill the validation questionnaires, from their answers in the questionnaire inferred that the board game has positive result, which is to tell the participant that cooperation, communication and coordination is important, also the board game could attract their attention

On the Stability Domain of Systems of Three Arbitrary Charges

We present results on the stability of quantum systems consisting of a negative charge $-q_1$ with mass $m_{1}$ and two positive charges $q_2$ and $q_3$, with masses $m_{2}$ and $m_{3}$, respectively. We show that, for given masses $m_{i}$, each instability domain is convex in the plane of the variables $(q_{1}/q_{2}, q_{1}/q_{3})$. A new proof is given of the instability of muonic ions $(\alpha, p, \mu^-)$. We then study stability in some critical regimes where $q_3\ll q_2$: stability is sometimes restricted to large values of some mass ratios; the behaviour of the stability frontier is established to leading order in $q_3/q_2$. Finally we present some conjectures about the shape of the stability domain, both for given masses and varying charges, and for given charges and varying masses.Comment: Latex, 24 pages, 14 figures (some in latex, some in .eps

Dissecting Mg2+-RNA interactions using atomistic molecular dynamics

The central dogma of molecular biology summarizes one of the most important mechanisms for the functioning of living organisms, stating that deoxyribonucleic acid (DNA) is transcribed into ribonucleic acid (RNA), which is then translated into proteins. However, it is still not sufficient to capture how important RNA are for cellular life. Nucleic acids are at the core of any living cell on this planet and thus deserve indisputably deserve scientific attention. In particular, RNA molecules are proposed as the key chemical species that ignited the beginning of life on prebiotic earth. Independently of this hypothesis, studying RNA molecules today is essential for numerous applications in life sciences, spanning from drug development to cancer treatment. That being said, in the last half century there have been unprecedented efforts into understanding RNAs and their role in the cell to the utmost detail. RNA is transcribed from DNA and translated into proteins, which then perform an abundance of functions in the cell. On top of that, it can catalyze chemical reactions, regulate gene expression and even carry genetic information which is retrotranscribed into DNA. The outstanding versatility of RNA molecules is due to their unique chemical features, resulting in a very flexible backbone combined with strong interactions between the nucleobases. The balance between canonical base pairs and a multitude of backbone conformations is the main factor for RNA being well structured yet dynamical. On the other hand, RNA folding can only occur in the presence of positively charged particles that compensate the electrostatic repulsion arising from the negatively charged sugar-phosphate backbone, inevitably tying nucleic acids and ions together. Metal ions are instrumental for proper RNA folding and dynamics, while also being crucial cofactors for ribozyme catalysis. Monovalent cations (Na+, K+) are the workhorses compensating the overall negatively charged nucleic acids, while divalent cations are frequently the protagonists of relevant folding events and catalysis. Mg2+ ions, which are the most freely available divalent cations in cells, commonly perform as structural pillars in RNA tertiary structures. Despite the ubiquitous presence of Mg2+ around RNA, the experimental characterization of their interaction is challenging, because Mg2+ do not offer a direct spectroscopic handle for detection and requires high-resolution X-ray crystallography. On top of that, their assignment through X-ray diffraction is difficult, since the Mg2+ is isoelectronic with water and Na+ ions. Therefore, the use of theoretical and computational tools can clearly help reinforce the experimental characterization of Mg2+-RNA interaction and contribute to the most needed dynamical view of these molecules. The results presented in this thesis aim to provide a meaningful description of the interaction between Mg2+ ions and RNA through atomistic molecular dynamics coupled with enhanced sampling techniques. The simulations done in this work were designed to tackle the two most fundamental issues in describing divalent ions interaction with RNA using molecular dynamics. First, the quality and fidelity of the models used, and second the proper sampling of rare events. Through the employment of modified state-of-the-art simulations techniques, I was able to predict Mg2+ binding sites and their correspondent affinities on an RNA duplex. The affinities qualitatively agree with the interaction frequency trends observed in the structural databases (PDB 1 or NDB 2). Furthermore, I evaluated relevant aspects of RNA simulation concerning force field choices for Mg2+ ions, RNA backbone non-bridging oxygens, and water. Lastly, I developed a robust methodological framework that allows for future molecular dynamics simulations aimed to study multiple concurrent binding events associated with high free-energy barriers. Since RNA folding is intrinsically dependent on ionic conditions, I hope that this work will facilitate future research on this important subject

GSU Event Portal

This project provides an event ticket buying service for the registered members of the service. This project will be engineered by a three-member team that will create the website, document the project, and define the constraints of the project. The website that will be developed will display current and future events given in major cities throughout the United States. Each city will have venues that the website will provide tickets for. The project will center on entertainment events. Entertainment events are defined as sporting, such as baseball, basketball, football and hockey, concerts and movies. The project is intended to provide registered members first choice of entertainment tickets. Non-registered guests are unable to browse the website. The sponsor of the entertainment events is given a venue of distributing tickets of their events. The project will be developed using HTML, CSS, jQuery, and .Net (C#). The application will aim to fulfil the above mentioned features, along with specific backend functions such as administrator access and database manipulation

Computational analysis reveals increased blood deposition following repeated mild traumatic brain injury.

Mild traumatic brain injury (mTBI) has become an increasing public health concern as subsequent injuries can exacerbate existing neuropathology and result in neurological deficits. This study investigated the temporal development of cortical lesions using magnetic resonance imaging (MRI) to assess two mTBIs delivered to opposite cortical hemispheres. The controlled cortical impact model was used to produce an initial mTBI on the right cortex followed by a second injury induced on the left cortex at 3 (rmTBI 3d) or 7 (rmTBI 7d) days later. Histogram analysis was combined with a novel semi-automated computational approach to perform a voxel-wise examination of extravascular blood and edema volumes within the lesion. Examination of lesion volume 1d post last injury revealed increased tissue abnormalities within rmTBI 7d animals compared to other groups, particularly at the site of the second impact. Histogram analysis of lesion T2 values suggested increased edematous tissue within the rmTBI 3d group and elevated blood deposition in the rm TBI 7d animals. Further quantification of lesion composition for blood and edema containing voxels supported our histogram findings, with increased edema at the site of second impact in rmTBI 3d animals and elevated blood deposition in the rmTBI 7d group at the site of the first injury. Histological measurements revealed spatial overlap of regions containing blood deposition and microglial activation within the cortices of all animals. In conclusion, our findings suggest that there is a window of tissue vulnerability where a second distant mTBI, induced 7d after an initial injury, exacerbates tissue abnormalities consistent with hemorrhagic progression