Routing scheme for macro mobility handover in hierarchical mobile IPv6 network

Significant problems in basic mobile IPv6 occur due to its inability to support micro-mobility because of long delay and high packet loss during handover. Hierarchical mobile IPv6 (HMIPv6) as an extension of basic Mobile IPv6 solves the problem by separating the handover management to macromobility and micro-mobility. HMIPv6 introduced a new protocol element called Mobility Anchor Point (MAP) to manage the mobility. HMIPv6 can reduce the delay and the amount of signaling during handover. However the protocol still cannot meet the requirement for traffic that is delay sensitive such as voice especially in macro mobility management. Duplicate address detection and the transmission time for the handover operation could cause high handover delay

Optical delay control of large-spectral-bandwidth laser pulses

In this letter we report the first experimental observation of temporal delay control of large-spectral-bandwidth multimode laser pulses by means of electromagnetically induced transparency (EIT). We achieved controllable retardation with limited temporal distortion of optical pulses with an input spectral bandwidth of 3.3 GHz. The experimental results compare favorably with theoretical predictions.Comment: Submitted to Optics Letters (January 2009

Pedagogical reflections of Muslim-Filipino Madrasah teachers: A phenomenological study

The purpose of the paper wasto explore the pedagogical reflections of Madrasah teachers or Asatidzas program implementers of Madrasah Education Program (MEP) in selected Arabic Language and Islamic Values Education (ALIVE) schools in Metro Manila, Philippines and identify salient themes on their lived experiences on teaching and learning process. Thisstudy utilized qualitative method of research usingtranscendental phenomenological approach of Moustakas (1994) as adapted from Husserl (1931), employing in-depth interviews and understanding of the participants’ description of their lived experiences. The authors used purposive sampling with ten research participants across Metro Manila. There were four (4) major themes identified in the study: (1) Teacher with divine responsibility; (2) Teacher as role model; (3) Teacher equipped with pedagogical practices; (4) Student-centered approach to teaching and learning. This study providedenrichment of evidence-based research especially on the lived experiences of grassroots implementers. Fewer studies on MEP were conducted especially on instructional process and particularly in teaching and learning process in the Philippines. The results servedas groundwork for more in-depth understanding of Madrasah teachers’ pedagogical practices as an integral part of the educative process

Optimal shapes of compact strings

Optimal geometrical arrangements, such as the stacking of atoms, are of relevance in diverse disciplines. A classic problem is the determination of the optimal arrangement of spheres in three dimensions in order to achieve the highest packing fraction; only recently has it been proved that the answer for infinite systems is a face-centred-cubic lattice. This simply stated problem has had a profound impact in many areas, ranging from the crystallization and melting of atomic systems, to optimal packing of objects and subdivision of space. Here we study an analogous problem--that of determining the optimal shapes of closely packed compact strings. This problem is a mathematical idealization of situations commonly encountered in biology, chemistry and physics, involving the optimal structure of folded polymeric chains. We find that, in cases where boundary effects are not dominant, helices with a particular pitch-radius ratio are selected. Interestingly, the same geometry is observed in helices in naturally-occurring proteins.Comment: 8 pages, 3 composite ps figure

Stereochemical Criteria for Prediction of the Effects of Proline Mutations on Protein Stability

When incorporated into a polypeptide chain, proline (Pro) differs from all other naturally occurring amino acid residues in two important respects. The φ dihedral angle of Pro is constrained to values close to −65° and Pro lacks an amide hydrogen. Consequently, mutations which result in introduction of Pro can significantly affect protein stability. In the present work, we describe a procedure to accurately predict the effect of Pro introduction on protein thermodynamic stability. Seventy-seven of the 97 non-Pro amino acid residues in the model protein, CcdB, were individually mutated to Pro, and the in vivo activity of each mutant was characterized. A decision tree to classify the mutation as perturbing or nonperturbing was created by correlating stereochemical properties of mutants to activity data. The stereochemical properties including main chain dihedral angle φ and main chain amide H-bonds (hydrogen bonds) were determined from 3D models of the mutant proteins built using MODELLER. We assessed the performance of the decision tree on a large dataset of 163 single-site Pro mutations of T4 lysozyme, 74 nsSNPs, and 52 other Pro substitutions from the literature. The overall accuracy of this algorithm was found to be 81% in the case of CcdB, 77% in the case of lysozyme, 76% in the case of nsSNPs, and 71% in the case of other Pro substitution data. The accuracy of Pro scanning mutagenesis for secondary structure assignment was also assessed and found to be at best 69%. Our prediction procedure will be useful in annotating uncharacterized nsSNPs of disease-associated proteins and for protein engineering and design

Statics, metastable states and barriers in protein folding: A replica variational approach

Protein folding is analyzed using a replica variational formalism to investigate some free energy landscape characteristics relevant for dynamics. A random contact interaction model that satisfies the minimum frustration principle is used to describe the coil-globule transition (characterized by T_CG), glass transitions (by T_A and T_K) and folding transition (by T_F). Trapping on the free energy landscape is characterized by two characteristic temperatures, one dynamic, T_A the other static, T_K (T_A> T_K), which are similar to those found in mean field theories of the Potts glass. 1)Above T_A, the free energy landscape is monotonous and polymer is melted both dynamically and statically. 2)Between T_A and T_K, the melted phase is still dominant thermodynamically, but frozen metastable states, exponentially large in number, appear. 3)A few lowest minima become thermodynamically dominant below T_K, where the polymer is totally frozen. In the temperature range between T_A and T_K, barriers between metastable states are shown to grow with decreasing temperature suggesting super-Arrhenius behavior in a sufficiently large system. Due to evolutionary constraints on fast folding, the folding temperature T_F is expected to be higher than T_K, but may or may not be higher than T_A. Diverse scenarios of the folding kinetics are discussed based on phase diagrams that take into account the dynamical transition, as well as the static ones.Comment: 41 pages, LaTeX, 9 EPS figure

Protein folding using contact maps

We present the development of the idea to use dynamics in the space of contact maps as a computational approach to the protein folding problem. We first introduce two important technical ingredients, the reconstruction of a three dimensional conformation from a contact map and the Monte Carlo dynamics in contact map space. We then discuss two approximations to the free energy of the contact maps and a method to derive energy parameters based on perceptron learning. Finally we present results, first for predictions based on threading and then for energy minimization of crambin and of a set of 6 immunoglobulins. The main result is that we proved that the two simple approximations we studied for the free energy are not suitable for protein folding. Perspectives are discussed in the last section.Comment: 29 pages, 10 figure

Dinamica unor indici biochimici în tratamentul litiazei urinare cu Shilintong

Summary Urinary enzymes N-acetil-β-D-glucosam inidase (NAG), Lactate dehydrogenase (LDH), β2-microglobulin (β2-M) levels in blood and urine were measured in the 20 patients with urolithiasis treated with Shilintong and in 26 patients treated using alternate drugs for urolithiasis in association with antibacterial treatment. It was found that the levels of β2-M were high in both the groups before the treatment in com parision to the control group. While it was found that after the treatment the high level of β2-M are present only in first group, this indicates the process of tubular damage. The levels of NAG and LDH were found to remain high in both the groups before and after the treatment this indicates cellular dam age to the tubules indicating the development of pyelonephrites. Shellintong has been found not to be nephrotoxic