Comparison of 16S rRNA gene sequences of genus Methanobrevibacter

BACKGROUND: The phylogeny of the genus Methanobrevibacter was established almost 25 years ago on the basis of the similarities of the 16S rRNA oligonucleotide catalogs. Since then, many 16S rRNA gene sequences of newly isolated strains or clones representing the genus Methanobrevibacter have been deposited. We tried to reorganize the 16S rRNA gene sequences of this genus and revise the taxonomic affiliation of the isolates and clones representing the genus Methanobrevibacter. RESULTS: The phylogenetic analysis of the genus based on 786 bp aligned region from fifty-four representative sequences of the 120 available sequences for the genus revealed seven multi-member groups namely, Ruminantium, Smithii, Woesei, Curvatus, Arboriphilicus, Filiformis, and the Termite gut symbionts along with three separate lineages represented by Mbr. wolinii, Mbr. acididurans, and termite gut flagellate symbiont LHD12. The cophenetic correlation coefficient, a test for the ultrametric properties of the 16S rRNA gene sequences used for the tree was found to be 0.913 indicating the high degree of goodness of fit of the tree topology. A significant relationship was found between the 16S rRNA sequence similarity (S) and the extent of DNA hybridization (D) for the genus with the correlation coefficient (r) for logD and logS, and for [ln(-lnD) and ln(-lnS)] being 0.73 and 0.796 respectively. Our analysis revealed that for this genus, when S = 0.984, D would be <70% at least 99% of the times, and with 70% D as the species "cutoff", any 16S rRNA gene sequence showing <98% sequence similarity can be considered as a separate species. In addition, we deduced group specific signature positions that have remained conserved in evolution of the genus. CONCLUSIONS: A very significant relationship between D and S was found to exist for the genus Methanobrevibacter, implying that it is possible to predict D from S with a known precision for the genus. We propose to include the termite gut flagellate symbiont LHD12, the methanogenic endosymbionts of the ciliate Nyctotherus ovalis, and rat feces isolate RT reported earlier, as separate species of the genus Methanobrevibacter

FE Analysis of High Pressure Laminate Panel for High Rise Building

:In present study, numerical analysis carried out on Aluminium, Duralcan and their composite (HPL-High pressure laminate) Panels, implemented through a finite element model (FEM) as a unique quasi-static solution for adequacy of HPL as cladding for high rise buildings. The HPL panel is multi-stiffened material made by bonding stiff between high strength skins facing to low-density material. In current study, different sizes and different materials stiffened panels analyzed under lateral and wind response at high-rise building. The details study on materials (Aluminium, Duralcan and HPL) provide losses during the shear strength due to buckling. The model is implemented and calibrated with a numerical model developed in previous studies. High Pressure Laminates provides resistance to environmental effects, more durable and cheaper for decor surface. An achievement in overall performance under cyclic loading and high wind pressure of HPL is observed as an infill panel, later on also utilized as cladding. Furthermore, thermal insulation study should be carried out to check full occupancy of HPL for in situ practices

Superconductivity with high upper critical field in Ta-Hf Alloys

High upper-critical field superconducting alloys are required for superconducting device applications. In this study, we extensively characterized the structure and superconducting properties of alloys Ta$_{x}$ Hf$_{1-x}$ (x = 0.2, 0.4, 0.5, 0.6 and 0.8). The substitution of Hf (T$_{C}$ = 0.12 K, type-I superconductor) with Ta (T$_{C}$ = 4.4 K, type-I superconductor) shows an anomalous enhancement of T$_{C}$ with variation of composition. Interestingly, all compositions exhibited strongly coupled bulk type-II superconductivity with a high upper critical field. In particular, for compositions x = 0.2, and 0.4, the upper critical field (H$_{C2}$) approached the Pauli limiting field.Comment: 8 pages, 6 figure

RF Controlled Robotic Vehicle with Metal Detection Project

The project is intended to cultivate a robotic vehicle that can sense metals ahead of it on its path similar to detecting land mines. The robot is controlled by a remote using RF technology. It consists of a metal detector circuit interfaced to the control unit that alarms the user behind it about a doubted land mine ahead. An 8051 series of microcontroller is used for the preferred operation. For controlling the movement of robot either to forward, backward & right or left commands are sent to the receiver by using push buttons of the transmitter. At the receiving end two motors are interfaced to the microcontroller where they are used for the movement of the vehicle. The RF transmitter acts as a RF remote control that has the advantage of sufficient range (up to 200 meters) with proper antenna, while the receiver decodes before serving it to another microcontroller to drive DC motors via motor driver IC for necessary work. A metal detector circuit is attached on the robot body and its operation is carried out automatically on sensing any metal underneath. The instant the robot senses this metal it produces an alarm sound through buzzer. This is to aware the operator of a probable metal (eg: land mine) ahead on its path. Further the project can be enhanced by mounting a wireless camera on the robot so that the operator can govern the movement of the robot remotely by observing it on a screen

Ring Slotted Circularly Polarized U-Shaped Printed Monopole Antenna for Various Wireless Applications

In this communication, the design and performance of strip line feed U-shaped printed monopole antenna for Bluetooth/WI-Max/WLAN communications systems is reported. Proposed monopole antenna has an eight shaped slot on the patch and an eight shaped ring structure in the ground plane with metallic reflector just beneath the radiating element. The CST Microwave Studio 2014 is used for the simulation analysis of antennas while measurements are performed by applying Vector Network Analyzer. This radiating structure provides triple broad impedance bandwidths i.e. 265MHz (in 2.280 GHz to 2.545 GHz frequency range), 116 MHz (in 2.660 GHz to 2.776 GHz frequency range) and&nbsp;2.12 GHz (in 3.83 GHz to 5.956 GHz frequency range), wider 3dB axial ratio bandwidth 1.33 GHz (in 4.69GHz to 6.02GHz range), flat gain (with maximum gain close to 5.56 (dBi) and good radiation patterns in the desired frequency range. This antenna may be a useful structure for 2.45GHz Bluetooth communication band as well as in WLAN and&nbsp;Wi-Max communications bands

Ring Slotted Circularly Polarized U-Shaped Printed Monopole Antenna for Various Wireless Applications

In this communication, the design and performance of strip line feed U-shaped printed monopole antenna for Bluetooth/WI-Max/WLAN communications systems is reported. Proposed monopole antenna has an eight shaped slot on the patch and an eight shaped ring structure in the ground plane with metallic reflector just beneath the radiating element. The CST Microwave Studio 2014 is used for the simulation analysis of antennas while measurements are performed by applying Vector Network Analyzer. This radiating structure provides triple broad impedance bandwidths i.e. 265MHz (in 2.280 GHz to 2.545 GHz frequency range), 116 MHz (in 2.660 GHz to 2.776 GHz frequency range) and 2.12 GHz (in 3.83 GHz to 5.956 GHz frequency range), wider 3dB axial ratio bandwidth 1.33 GHz (in 4.69GHz to 6.02GHz range), flat gain (with maximum gain close to 5.56 (dBi) and good radiation patterns in the desired frequency range. This antenna may be a useful structure for 2.45GHz Bluetooth communication band as well as in WLAN and Wi-Max communications bands

Triple-Notched Band CPW fed UWB Antenna with Metallic Reflector for High Gain Performance

This paper exhibits the design and performance of a coplanar waveguide (CPW) fed triple notched band ultra-wide band (UWB) antenna. Proposed prototype has two U-shaped slots on the patch and an inverted U slot in feed line with a metal reflector beneath the radiating element. Proposed structure renders wider impedance bandwidth extended between frequencies 2.71GHz to 12.92 GHz for VSWR &lt; 2 with three rejection bands in the frequency ranges 3.456 to 3.988 GHz (WI-MAX IEEE 802.16), 5.27 to 6.032 GHz (WLAN IEEE 802.11 a/h/j/n) and 7.88 to 8.65 GHz (X-band down link satellite system) for VSWR &gt; 2. The utmost simulated gain of proposed antenna with reflector is close to 9.9dBi at 7.4GHz. A sharp reduction observed in the efficiency values of the proposed structure at stop bands. Perhaps, this structure proved as a useful tool for various applications in modern communication systems including UWB

Impacts of organic and conventional crop management on diversity and activity of free-living nitrogen fixing bacteria and total bacteria are subsidiary to temporal effects

A three year field study (2007-2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted at the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. The result demonstrated that there was no consistent effect of either organic or conventional soil management across the three years on the diversity or quantity of either diazotrophic or total bacterial communities. However, ordination analyses carried out on data from each individual year showed that factors associated with the different fertility management measures including availability of nitrogen species, organic carbon and pH, did exert significant effects on the structure of both diazotrophic and total bacterial communities. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. The diazotrophic community showed no significant change in diversity across the three years, however, the total bacterial community significantly increased in diversity year on year. Diversity was always greatest during March for both diazotrophic and total bacterial communities. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. Seasonal effects were less consistent in this quantitative study