Inter Vehicle Distance based connectivity aware routing in vehicular adhoc networks

Connectivity in vehicular traffic environment has witnessed significant attention due to the direct impact on the performance of most of the traffic safety applications of intelligent transport system. Various parameters such as density, speed, direction, link quality and inter vehicle distance (IVD) have been utilized for measuring connectivity. IVD has greater impact on connectivity and controls the impact of other parameters. Usage of real time IVD for measuring connectivity has not received sufficient attention in VANETs. This paper proposes IVD based connectivity aware routing (Ivd-CAR) for enhancing connectivity aware data dissemination. IVD calculation is robust and can effectively handle instantaneous GPS failure. Two localization techniques; namely, cooperative localization and Geometry based Localization are developed. Standard deviation of real time IVDs of a forwarding path is derived. Distribution of IVDs of a forwarding path is employed for estimating connectivity. Segment vehicle based next hop vehicle selection is utilized for incorporating network load, link quality and direction into consideration while selecting forwarding path. Simulations are carried out in ns2 to evaluate the performance of Ivd-CAR in realistic traffic environment. Comparative analysis of simulation results attests the superiority of Ivd-CAR to the state-of-the-art techniques: CSR and A-CAR

A New Nested Allele-Specific Multiplex Polymerase Chain Reaction Method for Haplotyping of VKORC1 Gene to Predict Warfarin Sensitivity

The vitamin K epoxide reductase complex 1 gene (VKORC1) is commonly assessed to predict warfarin sensitivity. In this study, a new nested allele-specific multiplex polymerase chain reaction (PCR) method that can simultaneously identify single nucleotide polymorphisms (SNPs) at VKORC1 381, 861, 5808, and 9041 for haplotype analysiswas developed and validated. ExtractedDNAwas amplified in the first PCR DNA, which was optimized by investigating the effects of varying the primer concentrations, annealing temperature, magnesium chloride concentration, enzyme concentration, and the amount of DNA template. The amplification products produced from the first round of PCR were used as templates for a second PCR amplification in which both mutant and wild-type primers were added in separate PCR tubes, followed by optimization in a similar manner. The final PCR products were resolved by agarose gel electrophoresis and further analysed by using a VKORC1 genealogic tree to infer patient haplotypes. Fifty patients were identified to have H1H1, one had H1H2, one had H1H7, 31 had either H1H7 or H1H9, one had H1H9, eight had H7H7, and one had H8H9 haplotypes. This is the first method that is able to infer VKORC1 haplotypes using only conventional PCR methods

Performance of reactivated carbon nanotubes in adsorbing cadmium from aqueous solution

cadmium loaded carbon nanotubes (CNTs) for re-adsorption of the same metal cadmium (Cd). The desorption of cadmium ions (Cd2+) by batch mode laboratory experiments was investigated for hydrochloric and nitric acids, where the former gave better desorption compared to the other acid. Initial experiments revealed that hydrochloric acid (HCl) was better than nitric acid (HNO3)for the desorption of Cd2+ from the CNTs. Optimization study was conducted by design expert software using various molarities of HCl, which resulted in pH of 1.39 (0.1 M), pH 2.43 (0.01 M) and pH 3.53 (0.005 M). Contact time of 20, 50, 80, 110 and 140 minutes were used with fixed agitation of 200 rpm to study the effect of time on the desorption process. Statistical model was developed for the optimum desorption process, which provided a regression model with R2 value of 0.987. The desorbed CNTs were washed with deionized water to remove residual acids and then dried for re-adsorption process. The re-adsorption capacity of cadmium was also determined by batch mode experiments. This study revealed that pH and contact time influenced the desorption and re-adsorption capacity of the CNTs. The optimum condition for desorption was pH 1.39 (0.1 M) hydrochloric acid for 50 minutes agitation. This study also revealed that with this optimum condition, three (3) cycles of desorption process was necessary to remove all cadmium ion from the used CNTs. Re-adsorption capacity of the CNTs, after 3 cycles, was reduced from 8.28 mg/g to 4.23 mg/g. This indicated that about 50% of the adsorption capacity of the CNTs were destroyed or reduced due to the desorption process. Such reduction can also be linked to the destruction of the active sites of the CNT adsorbents

Environmental bacteriophages active on biofilms and planktonic forms of toxigenic Vibrio cholerae: Potential relevance in cholera epidemiology.

METHODS: Phages isolated from environmental waters in Bangladesh were tested for their host specificity towards V. cholerae O1 and O139, and the ability to disperse V. cholerae biofilms formed in the laboratory. Representative phages were further characterized by electron microscopy and whole genome sequencing. Selected phages were then introduced in various combinations to biofilms of toxigenic V. cholerae added to samples of river water, and the dispersion of biofilms as well as the growth kinetics of V. cholerae and the phages were monitored. RESULTS: A phage cocktail composed of three different phages isolated from surface waters in Bangladesh and designated as JSF7, JSF4, and JSF3 could significantly influence the distribution and concentration of the active planktonic form and biofilm associated form of toxigenic V. cholerae in water. While JSF7 showed a biofilm degrading activity and dispersed cells from both V. cholerae O1 and O139 derived biofilms thus increasing the concentration of planktonic V. cholerae in water, JSF4 and JSF3 showed strong bactericidal activity against V. cholerae O1 and O139 respectively. A mixture of all three phages could effectively reduce both biofilm-associated and planktonic V. cholerae in river water microcosms. SIGNIFICANCE: Besides potential applicability in phage-mediated control of cholera, our results have relevance in appreciating possible intricate role of diverse environmental phages in the epidemiology of the disease, since both biofilms and phages influence the prevalence and infectivity of V. cholerae in a variety of ways

Adsorption of lead from aqueous solution by a novel carbon based adsorbent

Lead (Pb), due to its bioaccumulation ability, has been noted to have detrimental effects on the human body affecting the metabolism, blood and kidneys (Bansal and Goyal, 2005; Bowen, 1996). It is, therefore, imperative that lead be removed from water and wastewater to protect public health and aquatic lives. Multiwall carbon nanotubes (MWCNT) were reported by Li et al. (2003) to have metal sorption capacity of 3–4 times higher than those of powder and granular activated carbon. However, membrane clogging and separation of the nanomaterials from the filtrate pose a challenge. In this work, a novel composite material consisting of carbon nanotubes (CNT) and granular activated carbon (GAC) was synthesised to solve the filtration problem in a static filter. Various percentages of nickel (1%, 3%, 5 and 7%) were used as substrate catalyst during production of the adsorbent and these were linked to the morphology and adsorption capacity of the novel material in lead adsorption. Analyses showed that increased nickel content in the substrate from 1% to 7%, during adsorbent production, resulted in a rough surface of the CNT and increased lead removal from 24% to 89%. Equilibrium concentrations of lead for the adsorbents were achieved at about 60 minutes of contact time. The novel composite material has the potential to remove toxic materials from water and bring benefit to the society

Comparing metals adsorption by carbon adsorbents: evaluating absorption properties of different carbon adsorbents

Pollution of the aquatic environment by heavy metals has detrimental effect on living species. In this work, novel carbon nano-materials (CNM) and commercial granular activated carbon (GAC) adsorbents were evaluated for removal of heavy metal matrix (Cu, Ni and Pb) from aqueous solution to meet Department of Environment (DOE) Malaysia's guideline. Results from the characterization of GAC and CNM showed that GAC had higher surface area and more functional groups. Optimum adsorption capacity of GAC and CNM were observed at pH 5 and 1 g/L dosage, while equilibrium adsorption conditions were generally noticed by 60 minutes of agitation at 100 rpm. The initial metal concentrations and functional groups on adsorbents were the major factors affecting the affinity of metals by both GAC and CNM

Aspects of the planetary Birkhoff normal form

The discovery in [G. Pinzari. PhD thesis. Univ. Roma Tre. 2009], [L. Chierchia and G. Pinzari, Invent. Math. 2011] of the Birkhoff normal form for the planetary many--body problem opened new insights and hopes for the comprehension of the dynamics of this problem. Remarkably, it allowed to give a {\sl direct} proof of the celebrated Arnold's Theorem [V. I. Arnold. Uspehi Math. Nauk. 1963] on the stability of planetary motions. In this paper, using a "ad hoc" set of symplectic variables, we develop an asymptotic formula for this normal form that may turn to be useful in applications. As an example, we provide two very simple applications to the three-body problem: we prove a conjecture by [V. I. Arnold. cit] on the "Kolmogorov set"of this problem and, using Nehoro{\v{s}}ev Theory [Nehoro{\v{s}}ev. Uspehi Math. Nauk. 1977], we prove, in the planar case, stability of all planetary actions over exponentially-long times, provided mean--motion resonances are excluded. We also briefly discuss perspectives and problems for full generalization of the results in the paper.Comment: 44 pages. Keywords: Averaging Theory, Birkhoff normal form, Nehoro{\v{s}}ev Theory, Planetary many--body problem, Arnold's Theorem on the stability of planetary motions, Properly--degenerate kam Theory, steepness. Revised version, including Reviewer's comments. Typos correcte