Heap Defragmentation in Bounded Time

Knuth’s buddy system is an attractive algorithm for managing storage allocation, and it can be made to operate in real time. However, the is-sue of defragmentation for heaps that are managed by the buddy system has not been studied. In this paper, we present strong bounds on the amount of storage necessary to avoid defragmentation. We then present an algorithm for defragmenting buddy heaps and present experiments from applying that algorithm to real and syn-thetic benchmarks. Our algorithm is within a factor of two of optimal in terms of the time re-quired to defragment the heap so as to respond to a single allocation request. Our experiments show our algorithm to be much more efficient than extant defragmentation algorithms

Operative Treatment of Isolated Bicondylar Hoffa Fracture With a Modified Swashbuckler Approach

Introduction: An isolated coronal fracture of either or both femoral condyles is a rare entity and is usually associated with high-energy injury trauma. Such fractures should be meticulously fixed for a good functional outcome as they involve the articular surface of a weight bearing joint. A modified swashbuckler approach provides adequate exposure for appropriate reduction and fixation of such fractures. Case Presentation: A 32-year-old male sustained a bicondylar Hoffa fracture of the right femur which was treated by open reduction and internal fixation using a modified swashbuckler approach. At two years of follow-up, the patient had excellent radiological and functional outcome. Conclusions: In our study, we treated this rare fracture successfully using a modified swashbuckler approach and found it to be a good approach for such fractures as compared to the conventional approach

SAGAXsearch: An XML Information Retrieval Mechanism: AN XML INFORMATION RETRIEVAL MECHANISM USING SELF ADAPTIVE GENETIC ALGORITHMS

The XML technology, with its self-describing and extensible tags, is significantly contributing to the next generation semantic web. The present search techniques used for HTML and text documents are not efficient when retrieving relevant XML documents. In this paper, Self Adaptive Genetic Algorithms are presented to learn about the tags, which are useful in indexing. The indices and relationship strength metric are used to extract fast and accurate semantically related elements in the XML documents. The Experiments are conducted on the DataBase systems and Logic Programming (DBLP) XML corpus and are evaluated for precision and recall. The proposed SAGAXsearch outperforms XSEarch3 and XRank20 with respect to accuracy and query execution time

Hafnium carbide formation in oxygen deficient hafnium oxide thin films

On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO$_{2-x}$) contaminated with adsorbates of carbon oxides, the formation of hafnium carbide (HfC$_x$) at the surface during vacuum annealing at temperatures as low as 600 {\deg}C is reported. Using X-ray photoelectron spectroscopy the evolution of the HfC$_x$ surface layer related to a transformation from insulating into metallic state is monitored in situ. In contrast, for fully stoichiometric HfO$_2$ thin films prepared and measured under identical conditions, the formation of HfC$_x$ was not detectable suggesting that the enhanced adsorption of carbon oxides on oxygen deficient films provides a carbon source for the carbide formation. This shows that a high concentration of oxygen vacancies in carbon contaminated hafnia lowers considerably the formation energy of hafnium carbide. Thus, the presence of a sufficient amount of residual carbon in resistive random access memory devices might lead to a similar carbide formation within the conducting filaments due to Joule heating

Pyrrolidine-based cationic γ-peptide: a DNA-binding molecule works as a potent anti-gene agent

Pyrrolidine-based cationic peptides showing high stability to enzyme degradation and strong binding affinity towards DNA are widely investigated as tools to interfere in gene expression. Several studies have been focused on γ-peptide analogs with modifications on the peptide backbone in the attempt to overcome solubility, uptake, and aggregation issues. Pyrrolidine-based γ-peptide derivatives having two different modes of backbone conformation show interesting properties in terms of secondary structure and affinity of binding towards nucleic acids. In this paper, we illustrate our results obtained on two cationic 8-mer γ-peptides Gp1 and Gp2, and how they differ in side-chain spacing along the backbone was tested for DNA binding and DNA transfection activity. Both γ-peptides are stable toward protease digestion. Gp1 binds to DNA more tightly than GP2. This binding ability of Gp1 is attributed to its characteristic of single-chain PPII-like conformation. The Gp1 shows a reduction in its electrophoretic mobility when treated with plasmid DNA. The DNA transfection ability of γ-peptide Gp1 was compared with commercially available transfection reagent Effectene. In each case, Gp1 significantly enhanced the transfection efficiency (40%) of plasmid in Schneider cells compared to the commercial reagent (18%). The other γ-peptide GP2 is not active

Pyrazole-based analogs as potential antibacterial agents against methicillin-resistance staphylococcus aureus (MRSA) and its SAR elucidation

Methicillin-resistant Staphylococcus aureus (MRSA) is becoming lethal to humanity due to easy transmission and difficult-to-treat skin and flimsy diseases. The most threatening aspect is the rapid resistance development of MRSA to any approved antibiotics, including vancomycin. The development of new, efficient, and nontoxic drug candidate to fight against MRSA isolates is the need of the hour. The intriguing molecular structure and versatile bioactive pyrazole core attracting to development required novel antibiotics. This review presents the decade developments of pyrazole-containing derivatives with a broad antibacterial movement against diverged bacterial strains. In specific, we correlated the efficacy of structurally diversified pyrazole analogs against MRSA and discussed different angles of structure-activity relationship (SAR). The current survey highlights pyrazole hybrids' present scenario on MRSA studies, covering articles published from 2011 to 2020. This collective information may become an excellent platform to plan and develop new pyrazole-based small MRSA growth inhibitors with minimal side effects. (C) 2020 Elsevier Masson SAS. All rights reserved

Temperature and terahertz frequency dependence of the dielectric properties of Fe3O4 thin films deposited on Si substrate

The Fe$_3$O$_4$/Si films are considered to be promising materials for THz spintronic applications due to their high temperature magnetic transition and semiconducting properties. In this article, we present the real part of the dielectric constant ($\epsilon_1$) and the optical conductivity ($\sigma_1$) of Fe$_3$O$_4$ films of different thicknesses deposited on Si substrate (Fe$_3$O$_4$/Si) in the THz range at temperatures 2- 300 K. Although the magnetization of the films with thickness $\geq$ 115 nm shows a clear change at the Verwey transition temperature T$_v$ = 121 K, their optical properties in the THz frequency range are drastically different from each other. We have shown that $\sigma_1$ is maximum and $\epsilon_1$ is minimum when the Fe$^{+2}$/Fe$^{+3}$ ratio is equal to 0.54 which is the ratio of Fe+2/Fe+3 for pure Fe$_3$O$_4$. The $\sigma_1$ reduces and $\epsilon_1$ increases at all temperatures when the Fe$^{+2}$/Fe$^{+3}$ ratio deviates from 0.54. We have shown that a slight change in the Fe$^{+2}$/Fe$^{+3}$ ratio can induce large changes in the optical properties which shall have implications in the application of the Fe3O4 films in THz spintronics.Comment: 18 pages, 6 figure