A Survey: Detection and Prevention of Wormhole Attack in Wireless Sensor Networks

Wireless Sensor Networks refers to a multi-hop packet based network that contains a set of mobile sensor nodes. Every node is free to travel separately on any route and can modify its links to other nodes. Therefore, the network is self organizing and adaptive networks which repeatedly changes its topology. The relations among nodes are restricted to their communication range, and teamwork with intermediate nodes is necessary for nodes to forward the packets to other sensor nodes beyond their communication range. The network2019;s broadcasting character and transmission medium help the attacker to interrupt network. An attacker can transform the routing protocol and interrupt the network operations through mechanisms such as selective forwarding, packet drops, and data fabrication. One of the serious routingdisruption attacks is Wormhole Attack. The main emphasis of this paper is to study wormhole attack, its detection method and the different techniques to prevent the network from these attack

A prospective observational study conducted in tertiary teaching hospital of Uttar Pradesh to compare safety and efficacy of PPIUCD and interval IUCD (380A)

Background: The objective of this study was to compare the efficacy and safety of PPIUCD and interval IUCD.Methods: This was a prospective observational study conducted on women attending the OPD and indoor services of S.N. Medical college, Agra. 800 women willing for PPIUCD insertion were included in the study after informed consent excluding chorioamnionitis, PROM>18 hours, unresolved PPH and puerperal sepsis. Another 200 willing women were inserted interval IUCD according to MEC criteria of WHO. All were followed up for 1 year.Results: It was found that rate of expulsion was more in PPIUCD group compared to interval IUCD group (6%vs 1.5% p value <.05),rate of removal was almost similar in both groups (11.5%inPPIUCD and 14%in interval IUCD group), cause of removal was mainly social in PPIUCD group while bleeding was more in interval IUCD group compared to PPIUCD (85.7%vs26%).Conclusions: Postpartum insertion of IUCD is a safe effective, feasible and reversible method of contraception

A new Lagrangian drift mechanism due to current–bathymetry interactions:applications in coastal cross-shelf transport

We show that in free surface flows, a uniform, streamwise current over small-amplitude wavy bottom topography generates cross-stream drift velocity. This drift mechanism, referred to as the current-bathymetry interaction induced drift (CBIID), is specifically understood in the context of a simplified nearshore environment consisting of a uniform alongshore current, onshore propagating surface waves, and monochromatic wavy bottom making an oblique angle with the shoreline. CBIID is found to originate from the steady, non-homogeneous solution of the governing system of equations. Similar to Stokes drift induced by surface waves, CBIID also generates a compensating Eulerian return flow to satisfy the no-flux lateral boundaries, e.g. the shoreline. CBIID increases with an increase in the particle's initial depth, bottom undulation's amplitude, and the strength of the alongshore current. Additionally, CBIID near the free (bottom) surface increases (decreases) with an increase in bottom undulation's wavelength. Maximum CBIID is obtained for long wavelength bottom topography that approximately makes $\pi/4$ angle with the shoreline. Unlike Stokes drift, particle excursions due to current-bathymetry interactions might not be small, hence analytical expressions based on the small-excursion approximation could be inaccurate. We provide an alternative $z$-bounded approximation, which leads to highly accurate expressions for drift velocity and time period of particles especially located near the free surface. Realistic parametric analysis reveals that in some nearshore environments, CBIID's contribution to the net Lagrangian drift can be as important as Stokes drift, implying that CBIID can have major implications in cross-shelf tracer transport

Modified Stokes drift due to resonant interactions between surface waves and corrugated sea floor with and without a mean current

In this paper, we show that Stokes drift may be significantly affected when an incident intermediate or shallow water surface wave travels over a corrugated sea-floor. The underlying mechanism is Bragg resonance -- reflected waves generated via nonlinear resonant interactions between an incident wave and a rippled bottom. We theoretically explain the fundamental effect of two counter-propagating Stokes waves on Stokes drift and then perform numerical simulations of Bragg resonance using High-order Spectral method. A monochromatic incident wave on interaction with a patch of bottom ripple yields a complex interference between the incident and reflected waves. When the velocity induced by the reflected waves exceeds that of the incident, particle trajectories reverse, leading to a backward drift. Lagrangian and Lagrangian-mean trajectories reveal that surface particles near the up-wave side of the patch are either trapped or reflected, implying that the rippled patch acts as a non-surface-invasive particle trap or reflector. On increasing the length and amplitude of the rippled patch; reflection, and thus the effectiveness of the patch, increases. The inclusion of realistic constant current shows noticeable differences between Lagrangian-mean trajectories with and without the rippled patch. Theoretical analysis reveals additional terms in the Stokes drift arising from the particular solution due to mean-current--bottom-ripple interactions, irrespective of whether Bragg resonance condition is met. Our analyses may be useful for designing artificial, corrugated sea-floor patches for mitigating microplastics and other forms of ocean pollution. We also expect that sea-floor corrugations, especially in the nearshore region, may significantly affect oceanic tracer transport

Vaginal foreign body in a 6 year old girl: a game for the child but a challenge for the gynaecologist

A 6 year old girl visited our gynaecology out-patient department of S.R.N hospital, Allahabad, India with the complaint of relapsing blood stained vaginal discharge for 3 months. Different gynaecologists, including us, tried treating the condition with different courses of antibiotics. To each, the girl responded only for few days and relapsed again. We investigated completely into the background of the child's home and school environment, her playing habits and her behaviour with her kins. Then, we got her various investigations done but with no derangement. With the backup of her history, examination and investigations, we performed another detailed examination of her genitals. The findings were intriguing as to their cause, and it definitely was a lesson to all of us.

Role of carboprost in prevention of postpartum hemorrhage

Background: Postpartum hemorrhage (PPH) is one of the most common causes of maternal death throughout the world. Pregnancy and childbirth involves significant health risks, even to women with no preexisting health problem. The objective of this study was to analyze the role of carboprost in prevention of PPH.Methods: This prospective observational study was conducted in the department of obstetrics and gynaecology of Dr. Sushila Tiwari Memorial Hospital, Haldwani, Uttarakhand, India. A total number of 100 cases delivering in the labour room that fulfilled the selection criteria were included. Carboprost 250 microgram (1 ml) was administered intramuscularly to each of the case just after the delivery of the anterior shoulder of baby. Duration of third stage, amount of blood loss, incidence of PPH and side effect profile was studied.Results: Carboprost reduces the duration and amount of blood loss in the third stage of labour but is associated with a number of unpleasant side effects.Conclusions: Active management of third stage of labour is recommended in all cases. Carboprost is highly efficacious in reducing the incidence of PPH

Performance Evaluation of Maximal Ratio Receiver Combining Diversity with Prime Interleaver for Iterative IDMA Receiver

The antenna diversity mechanism is established as the well known mechanism for reduction of probability of occurrence of communication failures (outages) caused by fades. In receiver diversity, multiple antennas are employed at the receiver side in case of transmitter diversity, multiple antennas are the integral part of transmitter section.. In this paper, Maximal Ratio Receiver Combining (MRRC) diversity technique is evaluated to mitigate the effect of fading in IDMA scheme employing random interleaver and prime interleaver with single transmit two receiving antennas in low rate coded environment. For the performance evaluation, channel is assumed to be Rayleigh multipath channel with BPSK modulation. Simulation results demonstrate the significant improvement in BER performance of IDMA with maximal ratio receiver combining (MRRC) diversity along with prime interleaver and random interleaver and it has also been observed that BER performance of prime interleaver is similar to that of random interleaver with reduced bandwidth and memory requirement at transmitter and receiver side. Keywords: Multipath Fading, MRRC diversity, Multi user detection, Interleave-Division Multiple Access (IDMA) Scheme, Random Interleaver, Prime Interleave