Search

Transport of rodlike particles in confinement environments of macromolecular networks plays crucial roles in many important biological processes and technological applications. The relevant understanding has been limited to thin rods with diameter much smaller than network mesh size, although the opposite case, of which the dynamical behaviors and underlying physical mechanisms remain unclear, is ubiquitous. Here, we solve this issue by combining experiments, simulations and theory. We find a nonmonotonic dependence of translational diffusion on rod length, characterized by length commensuration-governed unconventionally fast dynamics which is in striking contrast to the monotonic dependence for thin rods. Our results clarify that such a fast diffusion of thick rods with length of integral multiple of mesh size follows sliding dynamics and demonstrate it to be anomalous yet Brownian. Moreover, good agreement between theoretical analysis and simulations corroborates that the sliding dynamics is an intermediate regime between hopping and Brownian dynamics, and provides a mechanistic interpretation based on the rod-length dependent entropic free energy barrier. The findings yield a principle, that is, length commensuration, for optimal design of rodlike particles with highly efficient transport in confined environments of macromolecular networks, and might enrich the physics of the diffusion dynamics in heterogeneous media. Transport of rodlike particles in macromolecular networks is relevant to various biological processes and technological applications, where thin rods have been mainly in focus. Here the authors investigate diffusion dynamics of thick rods in confinement media of macromolecular networks, and uncover dependence of translational diffusion upon rod length. [ABSTRACT FROM AUTHOR]

Fermented rice is a traditional dish of Bangladesh and believed to contain various beneficial bacterial species. This study has been conducted to isolate and characterize bacteria from the samples of fermented rice. For this purpose, the samples were collected from three different districts of Bangladesh, namely Chapainawabganj, Rajshahi and Kushtia. A total of three bacterial isolates, denoted as Isolate 1, Isolate 2 and Isolate 3, were isolated from the fermented rice samples and identified by a series of morphological and biochemical tests. The three isolates were gram-positive, round-shaped and non-motile. For the biochemical characterization, the isolated bacteria were tested with several media like Mannitol Salt Agar, MacConkey Agar, EMB Agar, TSI Agar, Simmons Citrate Agar, Urea Agar, BSA and Starch Agar with Catalase assay. Thus the isolates have been confirmed as Staphylococcus sp. both morphologically and biochemically. The isolates were also tested for their antibiotic sensitivities by the disc diffusion method with twelve different antibiotics. All of the isolated bacteria showed resistance to three of the antibiotics, namely aztreonam, ampicillin and penicillin, and showed susceptibility to four, such as imipenem, ciprofloxacin, rifampicin and doxycycline. According to this study, it can be concluded that Staphylococcus sp. could be found in the fermented rice, and antibiotics are available to control these bacteria. [ABSTRACT FROM AUTHOR]

With the advent of different mobile computing technologies, mobile devices have opened up a plethora of computational infrastructure to provide improved performance for compute-intensive applications to the end users. Mobile Device Cloud (MDC) technology brings the code offloading mechanism from distant cloud to neighbor mobile devices. However, the major challenges of code offloading in MDC systems include maximization of computation speedup and reliability; unfortunately, these two performance parameters often oppose each other. In this paper, an optimization framework, namely TESAR, has been devised to tradeoff between application execution speedup and reliability while maintaining device energy within a predefined range. We also provide an algorithm for developing a dependency tree among the modules of an application so as to allow higher number of parallel executions, wherever and whenever it is possible. The emulation results of the proposed algorithm outperform the relevant state-of-the-art works in terms of application completion time, communication latency and rescheduling overhead. [ABSTRACT FROM AUTHOR]

In directional wireless sensor networks (DSNs), sensor nodes with directional antennas provide extended network lifetime and better coverage performance. However, one of the key challenges of directional nodes is to discover their neighbors due to difficulty in achieving synchronization among their directed transmissions and receptions. Existing solutions suffer from high discovery latency and poor percentage of neighbor discovery either due to lack of proper coordination or centralized management of the discovery operation. In this work, we develop a collaborative neighbor discovery (COND) mechanism for DSNs. Each COND node polls to directly discover its neighbors in a distributed way and collaborates with the already discovered nodes so as to allow indirect discovery. It helps to increase the neighbor discovery performance significantly. A Markov chain-based analytical model is developed to quantify theoretical performances of the proposed COND system. The performance of the COND system is evaluated in Network Simulator Version 3, and simulation results reveal that it greatly reduces the discovery latency and increases neighbor discovery ratio compared to state-of-the-art approaches. [ABSTRACT FROM AUTHOR]