A Review of Various Routing Protocols in VANET

Vehicular Ad Hoc Networks (VANET) is a subclass of Mobile ad hoc networks which provides a distinguished approach for Intelligent Transport System (ITS). VANET's provide communication between vehicles moving on the roads.Many protocols have been adopted to serve different topology and scenarios. We introduce and reviewPosition based Routing Protocols, Broadcast based routing protocols, Multicast/Geocast routing protocols, Cluster based routing protocols. The survey of routing protocols in VANET is very essential and necessary for smart ITS. This paper also discusses the advantages / disadvantages and the applications of the above mentioned routing protocols for vehicular ad hoc networks. The challenges and perspectives of routing protocols for VANET's are finally discussed

Effect of ESD on complex programmable logic device and field programmable gate arrays

Complex electronics devices are becoming more sensitive to electrostatic discharge (ESD). These components are being developed with higher density (extra memory bits per unit volume) and are becoming faster (MHz, GHz, THz, etc.). These upgrades in technology do not come without a "technological price". By enhancing the products' performance to meet the users' demands and requirements, one drawback is the reduction in the ESD sensitivity voltage levels. Indirect and direct air/contact discharge test has been conducted on the ALS-SDA-CPLD/FPGA trainer kit linked to the digital to analog converter (DAC) module. The Field Programmable Gate Arrays (FPGA) and Complex Programmable Logic Devices (CPLD) are found to be very ESD sensitive. The FPGA 3s50 IC was affected during the contact discharge to the input pin. There was damage to the bond pad as well as the metal top layer was damaged. The DAC ICs were affected during the ESD discharge " one due to direct ESD effects and the other due to indirect ESD effects. There was dielectric breakdown damage observed in the CPLD 9572 IC

Distribution of mercury in a tropical estuary (India) situated near a chloro-alkali plant

The distribution of mercury in water, sediment and some biological samples of the Rushikulya estuary, east coast of India were assessed during Jan-Dec. 1989. Both the dissolved plus acid leachable mercury contents in water and the sediment mercury discerned conspicuous spatial and seasonal fluctuations. Adsorption on to the suspended particulates was found to be the most likely mechanism for removal of mercury from the water column. Exchange of mercury from sediments to water was observed at high salinities (20-30x10-3). The residual mercury contents in the biological samples revealed that bio-accumulation by bottom-dwelling organisms are higher than the pelagic components

Structural insights into the role of the Smoothened cysteine-rich domain in Hedgehog signalling.

Smoothened (Smo) is a member of the Frizzled (FzD) class of G-protein-coupled receptors (GPCRs), and functions as the key transducer in the Hedgehog (Hh) signalling pathway. Smo has an extracellular cysteine-rich domain (CRD), indispensable for its function and downstream Hh signalling. Despite its essential role, the functional contribution of the CRD to Smo signalling has not been clearly elucidated. However, given that the FzD CRD binds to the endogenous Wnt ligand, it has been proposed that the Smo CRD may bind its own endogenous ligand. Here we present the NMR solution structure of the Drosophila Smo CRD, and describe interactions between the glucocorticoid budesonide (Bud) and the Smo CRDs from both Drosophila and human. Our results highlight a function of the Smo CRD, demonstrating its role in binding to small-molecule modulators

Mathematical analysis of ESD generated EM radiated fields on electronic subsystem

Electrostatic Discharge (ESD) generated Electromagnetic (EM) radiated fields can cause malfunctioning or upsets in an electronic system. This paper presents a mathematical computation of the effects of spatial electric fields from an ESD source. These fields may affect the normal functioning of an electronic system. This work uses a MATLAB program to model the response of Very High Frequency (VHF) amplifier to ESD generated radiated EM fields. The ESD source is a Capacitive Spark Discharge (CSD) source. The transient current element has been modeled as a short dipole. The electric field intensity and the magnetic field intensity have been computed by varying distance along the θ = π/2 direction for the CSD current. The frequency spectra of these E and H fields are obtained by taking Discrete Fourier Transform (DFT). The open circuit voltage induced by ESD generated transient fields at the antenna terminals and the voltage coupled to the input of the VHF amplifier fed by antenna is computed by varying distances. The time domain representation of the real part of the voltage at the output terminals of the VHF amplifier is computed by varying distance from the ESD source. Mathematical computation is carried out to predict the effect of the radiated fields on the induced voltages of a subsystem for various distances from the ESD source

Genetic separation of Sae2 nuclease activity from Mre11 nuclease functions in budding yeast

Sae2 promotes the repair of DNA double-strand breaks in Saccharomyces cerevisiae. The role of Sae2 is linked to the Mre11/Rad50/Xrs2 (MRX) complex, which is important for the processing of DNA ends into single-stranded substrates for homologous recombination. Sae2 has intrinsic endonuclease activity, but the role of this activity has not been assessed independently from its functions in promoting Mre11 nuclease activity. Here we identify and characterize separation-of-function mutants that lack intrinsic nuclease activity or the ability to promote Mre11 endonucleolytic activity. We find that the ability of Sae2 to promote MRX nuclease functions is important for DNA damage survival, particularly in the absence of Dna2 nuclease activity. In contrast, Sae2 nuclease activity is essential for DNA repair when Mre11 nuclease is compromised. Resection of DNA breaks is impaired when either Sae2 activity is blocked, suggesting roles for both Mre11 and Sae2 nuclease activities in promoting the processing of DNA ends in vivo. Finally, both activities of Sae2 are important for sporulation, indicating that the processing of meiotic breaks requires both Mre11 and Sae2 nuclease activities

Distinct repeat motifs at the C-terminal region of CagA of Helicobacter pylori strains isolated from diseased patients and asymptomatic individuals in West Bengal, India

Background: Infection with Helicobacter pylori strains that express CagA is associated with gastritis, peptic ulcer disease, and gastric adenocarcinoma. The biological function of CagA depends on tyrosine phosphorylation by a cellular kinase. The phosphate acceptor tyrosine moiety is present within the EPIYA motif at the C-terminal region of the protein. This region is highly polymorphic due to variations in the number of EPIYA motifs and the polymorphism found in spacer regions among EPIYA motifs. The aim of this study was to analyze the polymorphism at the C-terminal end of CagA and to evaluate its association with the clinical status of the host in West Bengal, India. Results: Seventy-seven H. pylori strains isolated from patients with various clinical statuses were used to characterize the C-ternimal polymorphic region of CagA. Our analysis showed that there is no correlation between the previously described CagA types and various disease outcomes in Indian context. Further analyses of different CagA structures revealed that the repeat units in the spacer sequences within the EPIYA motifs are actually more discrete than the previously proposed models of CagA variants. Conclusion: Our analyses suggest that EPIYA motifs as well as the spacer sequence units are present as distinct insertions and deletions, which possibly have arisen from extensive recombination events. Moreover, we have identified several new CagA types, which could not be typed by the existing systems and therefore, we have proposed a new typing system. We hypothesize that a cagA gene encoding higher number EPIYA motifs may perhaps have arisen from cagA genes that encode lesser EPIYA motifs by acquisition of DNA segments through recombination events