Adverse Maternal Outcomes in High-Order Multiple Pregnancies in a Private Health Facility in Nigeria: A 10-Year Experience

Background: Naturally occurring high-order multiple (HOM) pregnancies are rare (1 - 7 per 10,000) even in Nigeria noted to have the highest twinning rates. Worldwide multiple pregnancies are increasing and are associated with increased adverse maternal outcomes. Materials and Methods: This was a retrospective study of all patients with HOM pregnancy in Prime Medical Consultants between Jan 2004 to Dec 2013. We identified all the patients with high-order multiple pregnancy and extracted relevant data from the ante-natal and labour ward records, theatre records, and patients case notes. Demographic characteristics, gestational age at delivery, preterm rupture of membranes, preterm labour, hypertensive disease in pregnancy, proteinuria, anaemia, and postpartum haemorrhage were data extracted from the records. Results: The incidence of HOM pregnancy in this hospital was 0.24%. The mean maternal age was 35.7 ± 1.81 years. Over 85% of all the high-order multiple pregnancies in this hospital were from in-vitro fertilization and embryo transfer treatments for infertility. About 11% of the HOM pregnancy ended as spontaneous miscarriages. The mean gestational age at birth was 31 ± 1.5 weeks, and primary postpartum haemorrhage (22.2%) was the most common maternal adverse outcome from birth. Conclusion: The high incidence of HOM pregnancy in this hospital was mainly from in-vitro fertilization and embryo transfer. The HOM pregnancies are associated with high occurrence of preterm labour, caesarean sections and primary postpartum haemorrhage.

MULTIPLE RECIPROCITY METHOD WITH TWO SERIES OF SEQUENCES OF HIGH-ORDER FUNDAMENTAL SOLUTION FOR THIN PLATE BENDING

The boundary value problem of plate bending problem on two_parameter foundation was discussed.Using two series of the high_order fundamental solution sequences, namely, the fundamental solution sequences for the multi_harmonic operator and Laplace operator, applying the multiple reciprocity method(MRM), the MRM boundary integral equation for plate bending problem was constructed. It proves that the boundary integral equation derived from MRM is essentially identical to the conventional boundary integral equation. Hence the convergence analysis of MRM for plate bending problem can be obtained by the error estimation for the conventional boundary integral equation. In addition, this method can extend to the case of more series of the high_order fundamental solution sequences.

Consensus algorithm for multiple quadrotor systems under fixed and switching topologies

The distributed leadless consensus problem for multiple quadrotor systems under fixed and switching topologies is investigated. The objective is to design protocols achieving consensus for networked quadrotors＇ positions and attitudes. Because the model of a quadrotor is a strong high-order nonlinear coupling system, the approach of feedback linearization is employed to transform the model into a group of four linear subsystems among which there is no coupling. Then, a consensus algorithm is proposed which consists of a local feedback controller and interactions from the finite neighbors under fixed undirected topologies. Especially, the problem of choosing the parameters in the consensus algo-rithm is also addressed, enlightened by the results of the robust control theory. Furthermore, it is proved that the proposed algo-rithm also guarantees the consensus under undirected switching topologies. Simulation results show the effectiveness of the pro- posed algorithm.

Effect of multiple rescattering processes on harmonic emission in spatially inhomogeneous field

The effect of multiple rescattering processes on the harmonic emission from He atom in a spatially inhomogeneous field is discussed by solving the one-dimensional time-dependent Schrtdinger equation and the classical equation of motion. By establishing the physical model of the harmonic emission in the inhomogeneous field, we discuss the related characters of the multiple rescatterings process in the harmonic generation process. It shows that the second rescattering rather than the first rescattering tends to determine the harmonic cutoff energy when the inhomogeneous parameter is larger than 0.0055. Additionally, with the classica/simulation, the underlying physical mechanism of the continuum-continuum harmonics is also revealed. Moreover, this work may provide new physical insight into the harmonic generation in an inhomogeneous field, and is beneficial to further extract the harnaonic emission from molecular systems.

High-Order Iterative Methods Repeating Roots a Constructive Recapitulation

This paper considers practical, high-order methods for the iterative location of the roots of nonlinear equations, one at a time. Special attention is being paid to algorithms also applicable to multiple roots of initially known and unknown multiplicity. Efficient methods are presented in this note for the evaluation of the multiplicity index of the root being sought. Also reviewed here are super-linear and super-cubic methods that converge contrarily or alternatingly, enabling us, not only to approach the root briskly and confidently but also to actually bound and bracket it as we progress.