AMCTD: Adaptive Mobility of Courier nodes in Threshold-optimized DBR Protocol for Underwater Wireless Sensor Networks

In dense underwater sensor networks (UWSN), the major confronts are high error probability, incessant variation in topology of sensor nodes, and much energy consumption for data transmission. However, there are some remarkable applications of UWSN such as management of seabed and oil reservoirs, exploration of deep sea situation and prevention of aqueous disasters. In order to accomplish these applications, ignorance of the limitations of acoustic communications such as high delay and low bandwidth is not feasible. In this paper, we propose Adaptive mobility of Courier nodes in Threshold-optimized Depth-based routing (AMCTD), exploring the proficient amendments in depth threshold and implementing the optimal weight function to achieve longer network lifetime. We segregate our scheme in 3 major phases of weight updating, depth threshold variation and adaptive mobility of courier nodes. During data forwarding, we provide the framework for alterations in threshold to cope with the sparse condition of network. We ultimately perform detailed simulations to scrutinize the performance of our proposed scheme and its comparison with other two notable routing protocols in term of network lifetime and other essential parameters. The simulations results verify that our scheme performs better than the other techniques and near to optimal in the field of UWSN.Comment: 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

Knowledge and awareness of pregnant women about ultrasounsd scanning and prenatal diagnosis

Objective: Antenatal screening and ultrasound scan has become an integral part of the antenatal care in the present time. The aim of this study is to accurately describe the background knowledge and awareness of pregnant women about ultrasound scan and prenatal diagnosis.Methods: It is a clinic based cross sectional study. Four hundred women, attending the antenatal clinics, were asked to fill in a pre tested structured questionnaire. Different variables of interest were collected. Statistical Program for the social sciences (SPSS) was used for the data management.Results: Over 93.5% of the women were aware that ultrasound examination is an important investigation. They believed that it should be performed at least twice during pregnancy but were not sure about the timing of the test. Most of them felt that it was to check the growth of the baby and 97% of women considered ultrasound to be safe. However, only 26% of women had any knowledge about Down\u27s syndrome or its screening.Conclusion: Pregnant women in our set-up are aware of importance of ultrasound examination during pregnancy. However, there is a need to improve public awareness of problems like Down\u27s syndrome

Maternal anaemia and its impact on perinatal outcome in a tertiary care hospital in Pakistan

Maternal anaemia is a common problem in pregnancy, particularly in developing countries. We investigated the relationship between maternal anaemia and perinatal outcome in a cohort of 629 pregnant women from October 2001 to 2002. Of these, 313 were anaemic (haemoglobin \u3c 11 g/L). Perinatal outcomes included preterm delivery, low birth weight, intrauterine growth retardation, perinatal death, low Apgar scores and intrauterine fetal death. Univariate and multivariate analyses were performed. The risk of preterm delivery and low birth weight among the anaemic women was 4 and 1.9 times more respectively than the non-anaemic women. The neonates of anaemic women also had 1.8 times increased risk having low Apgar scores at 1 minute and there was a 3.7 greater risk of intrauterine fetal death among the anaemic women than the non-anaemic women

Maternal deaths in a developing country: A study from the Aga Khan University Hospital, Karachi, Pakistan 1988-1999

Objective: The maternal deaths occurring over a twelve-year period (1988-1999) in a tertiary referral center were reviewed. The purpose of the study was to assess the causes of these maternal deaths.Setting: The Aga Khan University Hospital (AKUH) Karachi, Pakistan.Methods: The medical records of maternal deaths were reviewed. These were women who had either registered for delivery at the hospital; or were referred from another hospital or from home, when an emergency developed. They were either admitted to the Medicine, Surgery and the Obstetrics and Gynaecology Departments at the hospital.Results: A total of 81 maternal deaths were identified, of which five were the registered patients. Causes of deaths were eclampsia, puerperal sepsis and pulmonary embolism. The maternal mortality ratio in the registered patients was 20 per 100,000 live births. Ninety percent of the women were between the age group of 15-35 years. Of these forty two percent were primigravidas, forty four percent of the women died due to direct causes, of which sepsis was the most common cause and accounted for twenty five percent of the total deaths. Indirect causes were responsible for 55.6% of the deaths, including hepatic failure in 21%, other infectious disease in 17% and malignancy in 5% of the cases.Conclusion: In developing countries other than obstetrical causes, infectious diseases contribute to the death of women during childbearing years. Comprehensive medical services and adequate obstetrical emergency services can lower maternal mortality rates at all levels

Female genital tuberculosis revisted

Objective: To assess the clinical presentation of genital tuberculosis and to study various modes of diagnosis and treatment.SETTING: The Aga Khan University Hospital (AKUH), Karachi.Method: A retrospective case review of all index female cases of genital tuberculosis, admitted to AKUH over twelve years of period.Result: A total of 40 cases of genital tuberculosis were reported during this time period. Majority of cases were between 25-45 years. The commonest presenting symptoms were infertility (42.5%) and abdominal pain (42%). Others included fever, ascites, irregular vaginal bleeding, oligomenorrhea, chest pain and pain in the flanks. Main mode of treatment was antituberculous drug therapy for duration of nine months. Only 3 patients had successful pregnancies.Conclusion: Genital tuberculosis should be excluded when managing infertility in females

Gestational diabetes in a developing country, experience of screening at the Aga Khan University Medical Centre, Karachi

In order to determine the prevalence of glucose intolerance in pregnancy, 1267 consecutive women attending the antenatal clinic of the Aga Khan University Medical Centre were subjected to a 75 g glucose challenge followed 2 hr later by plasma glucose determination irrespective of gestation on the first antenatal visit. The test was repeated at 28-32 weeks of gestation if the patients had an abnormal initial screen at less than 28 weeks gestation and a normal glucose tolerance test on diagnostic follow-up and for those who had a risk factor for gestational diabetes and a normal initial screen at less than 28 weeks gestation. The glucose challenge test was abnormal (2 hr plasma glucose greater than 140 mg%) in 8.6% of the screened population. Follow-up oral glucose tolerance test on these patients revealed a prevalence of 3.2% of gestational diabetes and 1.9% of impaired glucose tolerance test based on the modified O\u27Sullivan criteria. Improvement in cost effectiveness of screening programmes was adjudged possible by avoiding glucose tolerance tests in patients with 2 hr plasma glucose value of greater than 170 mg% after a 75 g oral glucose challenge for screening

Ground state magnetic structure of Mn3_3Ge

We have used spherical neutron polarimetry to investigate the magnetic structure of the Mn spins in the hexagonal semimetal Mn$_3$Ge, which exhibits a large intrinsic anomalous Hall effect. Our analysis of the polarimetric data finds a strong preference for a spin structure with $E_{1g}$ symmetry relative to the $D_{6h}$ point group. We show that weak ferromagnetism is an inevitable consequence of the symmetry of the observed magnetic structure, and that sixth order anisotropy is needed to select a unique ground state

Crystal and magnetic structure of the oxypnictide superconductor LaO(1-x)FxFeAs: evidence for magnetoelastic coupling

High-resolution and high-flux neutron as well as X-ray powder-diffraction experiments were performed on the oxypnictide series LaO(1-x)FxFeAs with 0<x<0.15 in order to study the crystal and magnetic structure. The magnetic symmetry of the undoped compound corresponds to those reported for ReOFeAs (with Re a rare earth) and for AFe2As2 (A=Ba, Sr) materials. We find an ordered magnetic moment of 0.63(1)muB at 2 K in LaOFeAs, which is significantly larger than the values previously reported for this compound. A sizable ordered magnetic moment is observed up to a F-doping of 4.5% whereas there is no magnetic order for a sample with a F concentration of x=0.06. In the undoped sample, several interatomic distances and FeAs4 tetrahedra angles exhibit pronounced anomalies connected with the broad structural transition and with the onset of magnetism supporting the idea of strong magneto-elastic coupling in this material.Comment: 8 pages, 7 figures, regular articl

Incommensurate antiferromagnetic fluctuations in single-crystalline LiFeAs studied by inelastic neutron scattering

We present an inelastic neutron scattering study on single-crystalline LiFeAs devoted to the characterization of the incommensurate antiferromagnetic fluctuations at $\mathbf{Q}=(0.5\pm\delta, 0.5\mp\delta, q_l)$. Time-of-flight measurements show the presence of these magnetic fluctuations up to an energy transfer of 60 meV, while polarized neutrons in combination with longitudinal polarization analysis on a triple-axis spectrometer prove the pure magnetic origin of this signal. The normalization of the magnetic scattering to an absolute scale yields that magnetic fluctuations in LiFeAs are by a factor eight weaker than the resonance signal in nearly optimally Co-doped BaFe$_2$As$_2$, although a factor two is recovered due to the split peaks owing to the incommensurability. The longitudinal polarization analysis indicates weak spin space anisotropy with slightly stronger out-of-plane component between 6 and 12 meV. Furthermore, our data suggest a fine structure of the magnetic signal most likely arising from superposing nesting vectors.Comment: 9 pages, 8 figure