Classical Trajectories of the Continuum States of the PT{\cal{PT}} symmetric Scarf II potential

We apply the factorization technique developed by Kuru et. al. [Ann. Phys. {\bf 323} (2008) 413] to obtain the exact analytical classical trajectories and momenta of the continuum states of the non Hermitian but ${\cal{PT}}$ symmetric Scarf II potential. In particular, we observe that the strange behaviour of the quantum version at the spectral singularity has an interesting classical analogue.Comment: 7 pages, 8 figure

Scattering in a varying mass PT symmetric double heterojunction

We observe that the reflection and transmission coefficients of a particle within a double, PT symmetric heterojunction with spatially varying mass, show interesting features, depending on the degree of non Hermiticity, although there is no spontaneous breakdown of PT symmetry. The potential profile in the intermediate layer is considered such that it has a non vanishing imaginary part near the heterojunctions. Exact analytical solutions for the wave function are obtained, and the reflection and transmission coefficients are plotted as a function of energy, for both left as well as right incidence. As expected, the spatial dependence on mass changes the nature of the scattering solutions within the heterojunctions, and the space-time (PT) symmetry is responsible for the left-right asymmetry in the reflection and transmission coefficients. However, the non vanishing imaginary component of the potential near the heterojunctions gives new and interesting results.Comment: 7 pages, 8 figure

Incidence, causes and feto-maternal outcomes of obstructed labour in a tertiary health care centre

Background: Obstructed labour is one of the most common preventable cause of maternal and neonatal morbidity and mortality in developing countries. This study was undertaken to assess the incidence, causes and feto-maternal outcomes of obstructed labour.Methods: This prospective study was carried out in the Department of Obstetrics and Gynaecology at Patna Medical College and Hospital, Patna, Bihar, India over a period of one year from February 2012 to February 2013. The 228 patients diagnosed to have obstructed labour were studied.Results: Out of 2556 deliveries conducted during this period, 228 cases of obstructed labour were found constituting an incidence of 8.9%. Majority of the patients were unbooked (89.47%), between 21-30 years of age (90.35%) and with parity 3 or more. The most common cause of obstructed labour was malposition (45.61%) followed by cephalopelvic disproportion (43.85%) and malpresentation (8.7%). caesarean section was the most common mode of delivery. In 21.92% of cases ruptured uterus was diagnosed pre-operatively among which, 2.63% has scar rupture and in remaining cases rupture was in unscarred uterus due to obstructed labour diagnosed intra-operatively. PPH was seen intra-operatively in 17.54% of cases and bladder trauma in 3.5% of cases. Most common post-operative complications were paralytic ileus (52.6%) followed by severe anaemia (48.2%) and infections (23.68%). Only 0.8% patients developed vesico-vaginal fistula as a late sequela of obstructed labour. The maternal mortality was 3.5% and perinatal mortality was 39%.Conclusions: In present study, the incidence of obstructed labour is very high. Good antenatal care, education of primary health care providers and traditional birth attendants on dangers of obstructed labour and the need for early referral is suggested to reduce the incidence of this condition