On the energetic origin of self-limiting trenches formed around Ge/Si quantum dots

At high growth temperatures, the misfit strain at the boundary of Ge quantum dots on Si(001) is relieved by formation of trenches around the base of the islands. The depth of the trenches has been observed to saturate at a level that depends on the base-width of the islands. Using finite element simulations, we show that the self-limiting nature of trench depth is due to a competition between the elastic relaxation energy gained by the formation of the trench and the surface energy cost for creating the trench. Our simulations predict a linear increase of the trench depth with the island radius, in quantitative agreement with the experimental observations of Drucker and coworkers

Counterfactual quantum certificate authorization

We present a multi-partite protocol in a counterfactual paradigm. In counterfactual quantum cryptography, secure information is transmitted between two spatially separated parties even when there is no physical travel of particles transferring the information between them. We propose here a tripartite counterfactual quantum protocol for the task of certificate authorization. Here a trusted third party, Alice, authenticates an entity Bob (e.g., a bank) that a client Charlie wishes to securely transact with. The protocol is counterfactual with respect to either Bob or Charlie. We prove its security against a general incoherent attack, where Eve attacks single particles.Comment: 6 pages, 2 figures, close to the published versio

Inter-hospital obstetric referrals: public versus private sector to a tertiary care teaching hospital in South Kerala, India

Background: Inter-hospital Emergency obstetric transfers should be carried out effectively and efficiently to avoid maternal and fetal morbidity and mortality. Authors would like  to analyse the determinants ,patterns and reasons for referrals to tertiary hospital  for women with obstetric high-risk, complications and obstetric emergencies  from both public and private sectors and look into course in hospital and their feto-matermal morbidities.Methods: Descriptive study done at a tertiary care teaching hospital where 124 obstetrical referrals from nearby private and public health sectors were recruited.Results: Infertility treated obstetric referrals were at significant risk of referral (p value-0.002). Public sector referrals had past history of early pregnancy loss which was significant (p value-0.002). Public sector had statistically significant in -labour referrals (p value-0.04). All the obstetric referrals from public health sector reached within half an hour while one third of private sector referrals travelled more than an hour for emergency obstetric care (p value 0.001). Bronchial Asthma caused significant morbidity among public sector referrals (p value-0.001). Public sector referrals <31 weeks were nil while 55 % obstetric referrals were referred <31 weeks from various private hospitals seeked neonatal care with significant p value (0.016). NICU admissions were statistically significant in private sector referrals (p-value 0.001). Mean hospital stay in private sector referrals was 10.17 days and it was 7.62 days in government referrals.Conclusions: Specific guidelines for whom to refer, how to refer, when to refer and where to refer would be helpful in making timely referral. More stringent documentation in the referral slips and more co-ordination between the referral unit and the higher centers are required to build a strong health system

Screening for perceived stress among pregnant women availing antenatal care at a tertiary care teaching institution in Kerala, India

Background: Stress during pregnancy can have serious adverse outcomes on the mother, the foetus and the new-born. It can lead to low-birth-weight, preterm births and neuro-psychological effects such as anxiety and depression during pregnancy and puerperium. This cross-sectional research aims to assess the severity of stress among postnatal women in Kerala. This study analysed socio-demographic, obstetric, family dynamics, neonatal characteristics and psychiatric determinants of postpartum stress using perceived stress scale (PSS) among postnatal women in a tertiary hospital in Kerala state, India.Methods: 119 women between 2 to 6 weeks of postpartum period were subjected to a pre-tested pre-structured standard questionnaire. Terminal illness, still birth delivery and comorbid psychiatric illness was excluded. Screening and diagnosis of postpartum stress was done based on perceived stress scale (PSS) and graded as mild 0-13, moderate 14-26, severe 27-40.Results: Study findings indicated a statistically significant association between postpartum stress and risk factors such as unplanned/unwanted pregnancy. The mean age of women was 27±4.8 years. Support from spouse and in-laws was a negative predictor of developing both postnatal stress and depression. Family income, education of couple and husbands’ occupations were non-determinant factors (p>0.05) in this study. Psychiatric illness in the family and past history of psychiatric illness also contributed to postnatal stress. The most important variable which influenced perceived stress during pregnancy was lengthier NICU stay. Even breastfeeding problems and associated neonatal issues worsened the stress scales significantly in the immediate postnatal period.Conclusions: This research concluded that stress detection and timely counselling along with mental and physical support will mitigate stress and postpartum depression

Response to the Letter to the Editor Regarding "Survey among Medical Students during COVID-19 Lockdown: The Online Class Dilemma"

We thank the editor for allowing us to respond to the comments by Akshara et al. The authors concur with us on unpreparedness and goes on to highlight how female doctors are over-worked during the pandemic. In this response, we also discuss why providing free data will not bring about significant change in students’ perception of online classes. We then advise how students can learn basic examination skills during the pandemic. Finally, we express our views on government and universities and finish with a recommendation that would help future doctors in times like the COVID-19 pandemic. &nbsp

Determinants and outcomes of caesarean delivery: elective versus emergency in a tertiary care teaching institute in Kerala, India

Background: Globally, the caesarean delivery rate is rising continuously, making caesarean one of the most common surgical procedures. The purpose was to analyse the determinants and maternofoetal outcomes in elective versus emergency caesarean sections in a tertiary care centre.Methods: All women, who gave birth by Caesarean deliveries done over a period of 1 year (January 2018-December 2018), were studied in Travancore Medical College in Kerala, India. Indications of caesarean, whether emergency or elective, medical morbidities, Gestational age at decision, birthweights and extended hospital stay and new-borns needed to resuscitate were looked into. The data was collected and analysed from the hospital registry.Results: Out of the 378 selected patients, 95 patients in group of elective and 283 emergency caesarean section were studied. The indications of emergency caesarean sections were failed induction, non-progression of labour, CPD, Previous caesarean in labour, foetal distress. The most frequent indicator for elective lower segment caesarean section (LSCS) was patient with previous LSCS not willing for vaginal birth, followed by breech presentation and high risk pregnancy ( BOH and ART). Younger mothers, gestational age remote from term, low-birth weight, and extended hospital stay were statistically significant in mothers undergoing emergency caesarean delivery. Fever, urinary tract infections, need for maternal and neonatal ventilation, blood transfusion, scar dehiscence were more common in the emergency caesarean group.Conclusions: The antenatal morbidity, low birth weights, decision taken preterm for salvaging the baby, postoperative complications and extended stay were more in the emergency caesarean when compared to elective caesarean

Prevalence and determinants of postnatal depression in a tertiary care teaching institute in Kerala, India

Background: Pregnancy and childbirth produce a variety of physiological, psychological and social consequences. Attitudes toward pregnancy and childbirth vary from culture to culture. Prevalence estimates range from 13 to 19% in resource-rich settings and 11 to 42% in resource- limited settings PND has a significant impact on the mother, the family, her partner and mother-infant interaction. This research aims to aid the early diagnosis of postnatal depression and the socio-demographic, obstetric, family dynamics, neonatal characteristics and psychiatric determinants of depression using EPDS among postnatal women in a tertiary hospital in Kerala state, India.Methods: 119 women between 2 to 6 weeks of postpartum period were subjected to a pre-tested pre-structured standard questionnaire. Diagnosis of depression was made using the Edinburgh postnatal depression scale. Possible depression is values >13 or more are invariably associated with depression.Results: Young age at marriage (p-value 0.022), love marriage (p-value 0.040) and low social support inadequate relationship with the in-laws was significantly associated with PND (p-0.003). Low birth weight was a significant determinant of PND (p-value-0.018). Gender of the new-born, fear and preference towards any particular gender and order of female child in multiparous woman had no association in determining postnatal depression. Childcare stress (p-value-0.011), psychiatry history in family and personal history of depression and mothers with low self-esteem (p-value-0.001) had odds of developing postnatal depression in the study.Conclusions: Early screening of the women and counselling of women and their family will reduce the maternal morbidity and adverse child outcomes

Development of a ROT22 - DATAMAP interface

This report (Contract NAS2-10331- Mod 10), outlines the development and validation of an interface between the three-dimensional transonic analysis program ROT22 and the Data from Aeromechanics Test and Analytics-Management and Analysis Package (DATAMAP). After development of the interface, the validation is carried out as follows. First, the DATAMAP program is used to analyze a portion of the Tip Aerodynamics and Acoustics Test (TAAT) data. Specifically, records 2872 and 2873 are analyzed at an azimuth of 90 deg, and record 2806 is analyzed at 60 deg. Trim conditions for these flight conditions are then calculated using the Bell performance prediction program ARAM45. Equivalent shaft, pitch, and twist angles are calculated from ARAM45 results and used as input to the ROT22 program. The interface uses the ROT22 results and creates DATAMAP information files from which the surface pressure contours and sectional pressure coefficients are plotted. Twist angles input to ROT22 program are then iteratively modified in the tip region until the computed pressure coefficients closely match the measurements. In all cases studied, the location of the shock is well predicted. However, the negative pressure coefficients were underpredicted. This could be accounted for by blade vortex interaction effects