Amplified fragment length polymorphism of clinical and environmental Vibrio cholerae from a freshwater environment in a cholera-endemic area, India

<p>Abstract</p> <p>Background</p> <p>The region around Chandigarh in India has witnessed a resurgence of cholera. However, isolation of <it>V. cholerae </it>O1 from the environment is infrequent. Therefore, to study whether environmental nonO1-nonO139 isolates, which are native to the aquatic ecosystem, act as precursors for pathogenic O1 strains, their virulence potential and evolutionary relatedness was checked.</p> <p>Methods</p> <p><it>V. cholerae </it>was isolated from clinical cases of cholera and from water and plankton samples collected from freshwater bodies and cholera-affected areas. PCR analysis for the <it>ctxA, ctxB, tcpA, toxT </it>and <it>toxR </it>genes and AFLP with six primer combinations was performed on 52 isolates (13 clinical, 34 environmental and 5 reference strains).</p> <p>Results</p> <p>All clinical and 3 environmental isolates belonged to serogroup O1 and remaining 31 environmental <it>V. cholerae </it>were nonO1-nonO139. Serogroup O1 isolates were <it>ctxA, tcpA </it>(ElTor), <it>ctxB </it>(Classical), <it>toxR </it>and <it>toxT </it>positive. NonO1-nonO139 isolates possessed <it>toxR</it>, but lacked <it>ctxA </it>and <it>ctxB</it>; only one isolate was positive for <it>toxT </it>and <it>tcpA</it>. Using AFLP, 2.08% of the <it>V. cholerae </it>genome was interrogated. Dendrogram analysis showed one large heterogeneous clade (n = 41), with two compact and distinct subclades (1a and 1b), and six small mono-phyletic groups. Although <it>V. cholerae </it>O1 isolates formed a distinct compact subclade, they were not clonal. A clinical O1 strain clustered with the nonO1-nonO139 isolates; one strain exhibited 70% similarity to the Classical control strain, and all O1 strains possessed an ElTor variant-specific fragment identified with primer ECMT. Few nonO1-nonO139 isolates from widely separated geographical locations intermingled together. Three environmental O1 isolates exhibited similar profiles to clinical O1 isolates.</p> <p>Conclusion</p> <p>In a unique study from freshwater environs of a cholera-endemic area in India over a narrow time frame, environmental <it>V. cholerae </it>population was found to be highly heterogeneous, diverse and devoid of major virulence genes. O1 and nonO1-nonO139 isolates showed distinct lineages. Clinical isolates were not clonal but were closely related, indicating accumulation of genetic differences over a short time span. Though, environment plays an important role in the spread of cholera, the possibility of an origin of pathogenic O1 strains from environmental nonO1-nonO139 strains seems to be remote in our region.</p

Deep optical survey of the stellar content of Sh2-311 region

The stellar content in and around Sh2-311 region have been studied using the deep optical observations as well as near-infrared (NIR) data from 2MASS. The region contains three clusters, viz. NGC 2467, Haffner 18 and Haffner 19. We have made an attempt to distinguish the stellar content of these individual regions as well as to re-determine their fundamental parameters such as distance, reddening, age, onto the basis of a new and more extended optical and infrared photometric data set. NGC 2467 and Haffner 19 are found to be located in the Perseus arm at the distances of 5.0 $\pm$ 0.4 kpc and 5.7 $\pm$ 0.4 kpc, respectively, whereas Haffner 18 is located at the distance of 11.2 $\pm$ 1.0 kpc. The clusters NGC 2467 and Haffner 19 might have formed from the same molecular cloud, whereas the cluster Haffner 18 is located in the outer galactic arm, i.e. the Norma-Cygnus arm. We identify 8 class II young stellar objects (YSOs) using the NIR $(J - H)/(H - K)$ two colour diagram. We have estimated the age and mass of the YSOs identified in the present work and those by Snider et al. (2009) using the $V/(V - I)$ colour-magnitude diagram. The estimated ages and mass range of the majority of the YSOs are $\lesssim$1 Myr and $\sim$0.4 - 3.5 \msun, respectively, indicating that these sources could be T-Tauri stars or their siblings. Spatial distribution of the YSOs shows that some of the YSOs are distributed around the H II region Sh2-311, suggesting a triggered star formation at its periphery.Comment: 19 pages, 13 figures, 9 table; Accepted for publication in New Astronom

Studies on intra-specific variations in the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae) under different geographical regions

Studies on intraspecific variations in insect pests are an important tool for preparation of management strategy in different geographical regions. In this paper we tried to establish that these variations are also found in the diamondback moth (P. xylostella) populations under north Indian conditions with respect to reproductive biology.The pest populations were collected from five different geographical regions viz. Hisar (800feet), Kangra (2200feet), Solan (4200 feet), Theog (7500feet) and Kinnaur (9000feet) and then reared under laboratory conditions at 25±1oC on cauliflower. The life table analysis revealed that the female from the Kangra population laid maximum eggs (332.16 eggs/female) whereas the number of eggs laid by the female from the Hisar, Solan, Theog and Kinnaur population was 189.53, 207, 252 and 270 eggs/female, respectively. The doubling time (DT) was observed to be the lowest for Kangra (3.12 days) and maximum for the Hisar (4.59 days) population, whereas weekly multiplication rate was minimum for the Solan (2.252) and maximum for the kangra (4.73) population. The true generation time was the lowest for the Kangra (18.54 days) and highest for the Hisar (24.38 days) population. The true intrinsic rate of increase (rm) was found to be maximum (0.222 female progeny/female/day) for the Kangra whereas for the Kinnaur, Theog, Solan and Hisar population it was 0.203, 0.202, 0.182 and 0.151 female progeny/female/day thereby indicating that the Kangra population is more prolific as compared to the population from other geographical regions. The results are indicative of geographical variations among different populations of P. xylostella

Wireless Sensor Network Based Real-Time Pedestrian Detection and Classification for Intelligent Transportation System

Pedestrian safety has become a critical consideration in developing society especially road traffic, an intelligent transportation need of the hour is the solution left. India tops the world with 11% of global road accidents. With this data, we have moved in the direction of computer vision applications for efficient and accurate pedestrian detection for intelligent transportation systems (ITS). The important application of this research is robot development, traffic management and control, unmanned vehicle driving (UVD), intelligent monitoring and surveillance system, and automatic pedestrian detection system. Much research has focused on pedestrian detection, but sustainable solution-driven research must still be required to overcome road accidents. We have proposed a wireless sensor network-based pedestrian detection system that classifies the real-time set of pedestrian activity and samples the reciprocally received signal strength (RSS) from the sensor node. We applied a histogram of oriented gradient (HOG) descriptor algorithm K-nearest neighbor, decision tree and linear support vector machine to measure the performance and prediction of the target. Also, these algorithms have performed a comparative analysis under different aspects. The linear support vector machine algorithm was trained with 481 samples. The performance achieves the accuracy of 98.90%and has accomplished superior results with a maximum precision of 0.99, recall of 0.98, and F-score of 0.95 with 2% error rate. The model’s prediction indicates that it can be used in the intelligent transportation system. Finally, the limitation and the challenges discussed to provide an outlook for future research direction to perform effective pedestrian detection

Multiwavelength study of a young open cluster NGC 7419

Using new UBVRI H αCCD photometric observations and the archival infrared and X-ray data, we have carried out a multiwavelength study of a Perseus arm young open star cluster NGC 7419. An age of 22.5 ± 3.0 Myr and a distance of 3230+330-430 pc are derived for the cluster. Our photometric data indicate a higher value of colour excess ratio E(U-B)/E(B-V) than the normal one. There is an evidence for mass segregation in this dynamically relaxed cluster and in the range 1.4-8.6 M⊚, the mass function slope is in agreement with the Salpeter value. Excess emissions in near-infrared and H α support the existence of a young (≤ 2 Myr) stellar population of Herbig Ae/Be stars (≥3.0 M⊚) indicating a second episode of star formation in the cluster region. Using XMM-Newton observations, we found several X-ray sources in the cluster region but none of the Herbig Ae/Be stars is detected in X-rays. We compare the distribution of upper limits for Herbig Ae/Be stars with the X-ray distribution functions of the T Tauri and the Herbig Ae/Be stars from previous studies, and found that the X-ray emission level of these Herbig Ae/Be stars is not more than LX~ 5.2 × 1030 ergs-1, which is not significantly higher than for the T Tauri stars. Therefore, X-ray emission from Herbig Ae/Be stars could be the result of either unresolved companion stars or a process similar to T Tauri stars. We report an extended X-ray emission from the cluster region NGC 7419, with a total X-ray luminosity estimate of ~1.8 × 1031 erg s-1 arcmin-2. If the extended emission is due to unresolved emission from the point sources then we estimate ~288 T Tauri stars in the cluster region each having X-ray luminosity ~1.0 × 1030 ergs-1. Investigation of dust attenuation and 12CO emission map of a square degree region around the cluster indicates the presence of a foreground dust cloud which is most likely associated with the local arm star-forming region (Sh2-154). This cloud harbours uniformly distributed pre-main-sequence stars (0.1-2.0 M⊚ ), with no obvious trend of their distribution with either (H-K) excess or AV. This suggests that the star formation in this cloud depend mostly upon the primordial fragmentation

Compensated hole-entry Hybrid Journal Bearing by CFV Restrictor under Micropolar Lubricants / Nathi Ram...[et al.]

In this work, the performance of hole-entry hybrid journal bearing compensated by constant flow valve (CFV) restrictor under micropolar lubricants has been numerically simulated. Reynolds equation for micropolar fluid lubricated bearing has been solved with finite element technique. Performance of bearing has been evaluated as a function of coupling number N² . The simulated characteristics of bearing under micropolar lubricants have been compared with similar bearing under Newtonian lubricant. The results are presented for the selected micropolar parameters N² and lm. Simulated results indicate that the bearing under micropolar lubricants exhibits the increased values of minimum fluid film thickness, stiffness and damping coefficients than similar bearing under Newtonian lubricant. Further, the coefficient of friction decreases for a bearing when it is operating under micropolar lubricant than Newtonian lubricant

Demonstration of Bias-Controlled Algorithmic Tuning of Quantum Dots in a Well (DWELL) MidIR Detectors

The quantum-confined Stark effect in intersublevel transitions present in quantum-dots-in-a-well (DWELL) detectors gives rise to a midIR spectral response that is dependent upon the detector\u27s operational bias. The spectral responses resulting from different biases exhibit spectral shifts, albeit with significant spectral overlap. A postprocessing algorithm was developed by Sakoglu that exploited this bias-dependent spectral diversity to predict the continuous and arbitrary tunability of the DWELL detector within certain limits. This paper focuses on the experimental demonstration of the DWELL-based spectral tuning algorithm. It is shown experimentally that it is possible to reconstruct the spectral content of a target electronically without using any dispersive optical elements for tuning, thereby demonstrating a DWELL-based algorithmic spectrometer. The effects of dark current, detector temperature, and bias selection on the tuning capability are also investigated experimentally