1,721 research outputs found
Implicit Coordination in Two-Agent Team Problems; Application to Distributed Power Allocation
The central result of this paper is the analysis of an optimization problem
which allows one to assess the limiting performance of a team of two agents who
coordinate their actions. One agent is fully informed about the past and future
realizations of a random state which affects the common payoff of the agents
whereas the other agent has no knowledge about the state. The informed agent
can exchange his knowledge with the other agent only through his actions. This
result is applied to the problem of distributed power allocation in a
two-transmitter band interference channel, , in which the
transmitters (who are the agents) want to maximize the sum-rate under the
single-user decoding assumption at the two receivers; in such a new setting,
the random state is given by the global channel state and the sequence of power
vectors used by the informed transmitter is a code which conveys information
about the channel to the other transmitter.Comment: 6 pages, appears as WNC3 2014: International Workshop on Wireless
Networks: Communication, Cooperation and Competition - International Workshop
on Resource Allocation, Cooperation and Competition in Wireless Network
Impacts of Air Pollution on Human Health, Plant and Vegetation
The subject has long been a matter of concern since the industrialization of the country brought in its pollution hazards. The present exposure to the environmental chemicals is more likely to produce toxicity that adult exposure. Subtle functional deviations in the off-springs of exposed mothers may be one of the most sensitive indications of potential harm from environmental chemicals. The air pollutants contaminate air, water and soil, corrode materials, dirty buildings and clothing, harm plants and wild life and affect human health. To determine that an environmental change is going to be unfavorable requires a careful study of ecological system, known as the ecosystem. In an ecosystem the living organisms are inter-related and well-adjusted to their environment, comprising biotic components of plants, animals and microbes. The correlation between growth transitions of green plants, which grow outdoors and are continuously exposed to pollutants, and pollutant concentrations have helped decipher pollution zones. These zones extend in the direction of the prevailing wind, assuming an elliptic shape; the axis of the ellipse being oriented from south-west to north-east direction with the pollution source at the south-west end. In such instances the north-east extension of the ellipse penetrates deep into the natural and rural habitats
Binary Atomic Silicon Logic
It has long been anticipated that the ultimate in miniature circuitry will be
crafted of single atoms. Despite many advances made in scanned probe microscopy
studies of molecules and atoms on surfaces, challenges with patterning and
limited thermal stability have remained. Here we make progress toward those
challenges and demonstrate rudimentary circuit elements through the patterning
of dangling bonds on a hydrogen terminated silicon surface. Dangling bonds
sequester electrons both spatially and energetically in the bulk band gap,
circumventing short circuiting by the substrate. We deploy paired dangling
bonds occupied by one movable electron to form a binary electronic building
block. Inspired by earlier quantum dot-based approaches, binary information is
encoded in the electron position allowing demonstration of a binary wire and an
OR gate
Complete genome sequence of carbonic anhydrase producing psychrobacter sp. SHUES1
© 2016 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence.
The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fmicb.2016.01442Recent advances in biotechnology have allowed the study of new bacterial strains, which can produce enzymes that can be used in the bioremediation of heavy metals. Microbially induced carbonate precipitation (MICP) is a recent well-recognized process that has the potential to precipitate heavy metals, mainly those with a valency of +2 (Kumari et al., 2016). There are two enzymes, urease, and carbonic anhydrase, that play an important role in the MICP process. The role of carbonic anydrase (EC 4.2.1.1) in MICP is generally underestimated and most of the studies in past mainly focus on urease-producing microorganisms (Li et al., 2013, 2014; Kumari et al., 2014). In the present study, Psychrobacter sp. SHUES1 was isolated from frozen alkaline soil sample collected at Shanghai, China. This bacterium produced lipase and protease at 4°C in a plate assay. The ability of Psychrobacter sp. to show extracellular lipolytic activity at low temperatures is widely known (Xuezheng et al., 2010); however, the remarkable property of this strain was in the precipitation of heavy metals including cadmium and zinc in parallel to the MICP process. Therefore, to know the type of enzyme or genes involved in the process of metal precipitation, this research aims to sequence the whole genome of Psychrobacter sp. SHUES1, and thus provide a genomic insight into its behavior. Genomic DNA from Psychrobacter sp. SHUES1 was extracted using the DNeasy Blood & Tissue Kit (Qiagen, USA), and its quantity and quality were evaluated on the Qubit. The extracted DNA was subjected to whole-genome shotgun sequencing using the NEBNext Ultra DNA Library Prep Kit (Illumina, San Diego, CA). Library construction was performed with the following process: DNA fragmentation, end repair, adding “A” to the 3′ end, adaptor ligation and amplification. After library construction, the generated cluster was sequenced on an Illumina HiSeq2500 sequencing system, according to a paired end 2 × 125 nt multiplex program. 13,716,515 raw reads resulted in 13,144,818 quality-filtered trimmed reads, yielding a not less than 3 Mb genome size. De novo genome assembly was performed using SPAdes-3.5.0. After purification, the assembly produced 3,115,590 bp of sequence across 115 contigs with an N50 of 47,049 bp, with a longest sequence of 182,144 bp, and a G+C content of 43.5% (Table 1). Gene prediction and annotation were carried out using Prodigal_v2.6.1, blastp in the National Center for Biotechnology Information (NCBI) “nr” database. Gene ontology (GO) functional annotation of genes was carried out using the blast2GO algorithm, dominated by the following features: biological process (44%), molecular process (42%), and cellular component (14%). Clusters of Orthologous Groups (COG) annotation was carried out in the NCBI COG database using rpsblast. A total of 2627 protein-coding genes, 45 tRNA-coding genes, and 6 rRNA genes were predicted in the draft genome. TABLE 1 www.frontiersin.org Table 1. Genome features of Psychrobacter sp. SHUES1. The most significant finding of the whole genome sequencing of Psychrobacter sp. SHUES1 was the presence of carbonic anhydrase gene in it. Carbonic anhydrase participates in all physiological processes dealing with CO2 and HCO3, such as cellular pH regulation, calcification, acid, and ion transport (Smith and Ferry, 2000; Achal and Pan, 2011). It catalyses the interconversion of CO2 and HCO3, which ultimately promotes the precipitation of calcium carbonate in the presence of Ca2+ ions. Although there are a number of genome sequences of Psychrobacter sp. deposited in NCBI database, this is the first characterization of the genome sequence of strain SHUES1, which produces carbonic anhydrase which has a significant role in metal bioremediation based on the ability to promote the precipitation of metal carbonates. This sequencing result also suggests the importance of carbonic anhydrase in the MICP process which is a novel element in this field of research. The present study is especially valuable in the area of biomineralization based on MICP processes, in the bioremediation of metals and in the development of microbial concrete (biocement). Urease is the main enzyme responsible in such studies; however, in our study the urease gene was not present in Pyschrobacter sp. SHUES1. This indicates the importance of carbonic anhydrase, as a less studied secondary enzyme for the MICP process. It is hoped that this research will encourage other researchers to look for this carbonic anhydrase precipitation pathway when carrying out MICP studies
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