Signatures of quantum phases in a dissipative system.

Lindbladian formalism, as tuned to dissipative and open systems, has been all-pervasive to interpret non-equilibrium steady states of quantum many-body systems. We study the fate of free fermionic and superconducting phases in a dissipative one-dimensional Kitaev model-where the bath acts both as a source and a sink of fermionic particles with different coupling rates. As a function of these two couplings, we investigate the steady state, its entanglement content, and its approach from varying initial states. Interestingly, we find that the steady state phase diagram retains decipherable signatures of ground state critical physics. We also show that early-time fidelity is a useful marker to find a subclass of phase transitions in such situations. Moreover, we show that the survival of critical signatures at late-times, strongly depend on the thermal nature of the steady state. This connection hints at a correspondence between quantum observables and classical magnetism in the steady state of such systems. Our work uncovers interesting connections between dissipative quantum many-body systems, thermalization of a classical spin and many-body quantum critical phenomena.

Robust determinants of neurocognitive development in children: evidence from the Pune Maternal Nutrition Study.

Neurocognitive development is a dynamic process over the life course and is influenced by intrauterine factors as well as later life environment. Using data from the Pune Maternal Nutrition Study from 1994 to 2008, we investigate the association of in utero, birth, and childhood conditions with offspring neurocognitive development in 686 participants of the cohort, at age 12 years. The life course exposure variables in the analysis include maternal pre-pregnancy size and nutrition during pregnancy, offspring birth measurements, nutrition and physical growth at age 12 years along with parental education and socio-economic status. We used the novel Bayesian Model Averaging (BMA) approach; which has been shown to have better predictive performance over traditional tests of associations. Our study employs eight standard neurocognitive tests that measure intelligence, working memory, visuo-conceptual and verbal learning, and decision-making/attention at 12 years of age. We control for nutritional-metabolic information based on blood measurements from the pregnant mothers and the children at 12 years of age. Our findings highlight the critical role of parental education and socio-economic background in determining child neurocognitive performance. Maternal characteristics (pre-pregnancy BMI, fasting insulin during pregnancy) and child height at 12 years were also robust predictors on the BMA. A range of early factors - such as maternal folate and ferritin concentrations during pregnancy, and child's head circumference at birth - remained important determinants of some dimensions of child's neurocognitive development, but their associations were not robust once we account for model uncertainty. Our results suggest that intrauterine influences on long- term neurocognitive outcomes may be potentially reversible by post-birth remediation. In addition to the current nutritional interventions, public health policy should also consider social interventions in children born into families with low socio-economic status to improve human capital.

Twins in Guinea-Bissau have a 'thin-fat' body composition compared to singletons.

The 'thrifty phenotype' hypothesis proposed that fetal undernutrition increases risk of diabetes in later life. Undernourished low birthweight Indian babies are paradoxically more adipose compared to well-nourished European babies, and are at higher risk of diabetes in later life. Twin pregnancies are an example of in utero growth restrictive environment due to shared maternal nutrition. There are few studies of body composition in twins. We performed secondary analysis of anthropometric body composition of twins and singletons in Guinea-Bissau, an economically deprived African country.Anthropometric data were available on 7-34 year-old twins (n = 209, 97 males) and singletons (n = 182, 86 males) in the Guinea-Bissau Twin Registry at the Bandim Health Project. Twins had lower birthweight (2420 vs 3100 g, p < 0.001); and at follow-up, lower height (HAZ mean Z-score difference, -0.21, p = 0.055), weight (WAZ -0.73, p = 0.024) and BMI (BAZ -0.22, p = 0.079) compared to singletons but higher adiposity (skinfolds: +0.33 SD, p = 0.001). Twins also had higher fasting (+0.38 SD, p < 0.001) and 2-hour OGTT glucose concentrations (+0.29 SD, p < 0.05). Linear mixed-effect model accounting for intrapair correlations and interactions confirmed that twins were thinner but fatter across the age range. Data on maternal morbidity and prematurity were not available in this cohort.African populations are known to have a muscular (less adipose) body composition. Demonstration of a thin-fat phenotype in twins in a low socio-economic African country supports the thesis that it could be a manifestation of early life undernutrition and not exclusive to Indians. This phenotype could increase risk of diabetes and related conditions.

Corrigendum: Pre-conceptional Maternal Vitamin B12 Supplementation Improves Offspring Neurodevelopment at 2 Years of Age: PRIYA Trial.

[This corrects the article DOI: 10.3389/fped.2021.755977.].

Pre-conceptional Maternal Vitamin B12 Supplementation Improves Offspring Neurodevelopment at 2 Years of Age: PRIYA Trial.

Background: The first thousand days window does not include the pre-conceptional period. Maternal pre-conceptional health has a profound influence on early embryonic development (implantation, gastrulation, placentation etc). Nutrition provided by B-complex vitamins is important for fetal growth, especially neural development. We report effects of a maternal pre-conceptional vitamin B12 and multi micronutrient (MMN) supplementation on offspring neurodevelopmental performance. Methods: In the Pune Rural Intervention in Young Adolescents trial (PRIYA), adolescents (N = 557, 226 females) were provided with vitamin B12 (2 µg/day) with or without multiple micronutrients, or a placebo, from preconception until delivery. All groups received mandatory iron and folic acid. We used the Bayley's Scale of Infant Development (BSID-III) at 24-42 months of age to investigate effects on offspring neurodevelopment. Results: Participants had similar baseline B12 levels. The levels improved in the B12 supplemented groups during pre-conception and pregnancy (28 weeks gestation), and were reflected in higher cord blood holotranscobalamin (holo-TC) levels compared to the placebo group. Neurodevelopmental outcomes in the B12 alone group (n = 21) were better than the placebo (n = 27) in cognition (p = 0.044) and language (p = 0.020) domains (adjusted for maternal baseline B12 levels). There was no difference in neurodevelopmental outcomes between the B12 + MMN (n = 26) and placebo group. Cord blood Brain Derived Neurotrophic Factor (BDNF) levels were highest in the B12 alone group, though not significant. Conclusion: Pre-conceptional vitamin B12 supplementation improved maternal B12 status and offspring neurodevelopment at 2 years of age. The usefulness of cord BDNF as a marker of brain development needs further investigation. Our results highlight the importance of intervening during pre-conception.

Maternal vitamin B12, folate during pregnancy and neurocognitive outcomes in young adults of the Pune Maternal Nutrition Study (PMNS) prospective birth cohort: study protocol.

INTRODUCTION: The Developmental Origins of Health and Disease (DOHaD) hypothesis proposes that intrauterine and early life exposures significantly influence fetal development and risk for disease in later life. Evidence from prospective birth cohorts suggests a role for maternal B12 and folate in influencing neurocognitive outcomes in the offspring. In the Indian setting, B12 deficiency is common during the pregnancy while rates of folate deficiency are lower. The long-term influences of maternal nutrition during the pregnancy on adult neurocognitive outcomes have not been examined. The Pune Maternal Nutrition Study (PMNS) is a preconceptional birth cohort into its 24th year and is considered a unique resource to study the DOHaD hypothesis. We found an association between maternal B12 status in pregnancy and child's neurocognitive status at 9 years of age. We now plan to assess neurocognitive function and MRI measurements of brain structural-functional connectivity at young adult age to study its association with maternal nutritional exposures during the pregnancy. METHODS AND ANALYSIS: As part of ongoing prospective follow-up in young adults of the PMNS at the Diabetes Unit, KEM Hospital Research Center, Pune India, the following measurements will be done: neurocognitive performance (Standardised Tests of Intelligence, Verbal and Visual Memory, Attention and Executive Functions), temperament (Adult Temperament Questionnaire), psychopathology (Brief Symptom Inventory and Clinical Interview on Mini Neuropsychiatric Interview 7.0). Brain MRI for structural T1, resting-state functional connectivity and diffusion tensor imaging will be performed on a subset of the cohort (selected based on exposure to a lower or higher maternal B12 status at 18 weeks of pregnancy). ETHICS AND DISSEMINATION: The study is approved by Institutional ethics committee of KEM Hospital Research Center, Pune. The results will be shared at national and international scientific conferences and published in peer-reviewed scientific journals. TRIAL REGISTRATION NUMBER: NCT03096028.

Driven quantum many-body systems and out-of-equilibrium topology.

In this review we present some of the work done in India in the area of driven and out-of-equilibrium systems with topological phases. After presenting some well-known examples of topological systems in one and two dimensions, we discuss the effects of periodic driving in some of them. We discuss the unitary as well as the non-unitary dynamical preparation of topologically non-trivial states in one and two dimensional systems. We then discuss the effects of Majorana end modes on transport through a Kitaev chain and a junction of three Kitaev chains. Following this, transport through the surface states of a three-dimensional topological insulator has also been reviewed. The effects of hybridization between the top and bottom surfaces in such systems and the application of electromagnetic radiation on a strip-like region on the top surface are described. Two unusual topological systems are mentioned briefly, namely, a spin system on a kagome lattice and a Josephson junction of three superconducting wires. We have also included a pedagogical discussion on topology and topological invariants in the appendices, where the connection between topological properties and the intrinsic geometry of many-body quantum states is also elucidated.

Observing Dynamical Quantum Phase Transitions through Quasilocal String Operators.

We analyze signatures of the dynamical quantum phase transitions in physical observables. In particular, we show that both the expectation value and various out of time order correlation functions of the finite length product or string operators develop cusp singularities following quench protocols, which become sharper and sharper as the string length increases. We illustrated our ideas analyzing both integrable and nonintegrable one-dimensional Ising models showing that these transitions are robust both to the details of the model and to the choice of the initial state.

Probing ADP Induced Aggregation Kinetics During Platelet-Nanoparticle Interactions: Functional Dynamics Analysis to Rationalize Safety and Benefits.

Platelets, one of the most sensitive blood cells, can be activated by a range of external and internal stimuli including physical, chemical, physiological, and/or non-physiological agents. Platelets need to respond promptly during injury to maintain blood hemostasis. The time profile of platelet aggregation is very complex, especially in the presence of the agonist adenosine 5'-diphosphate (ADP), and it is difficult to probe such complexity using traditional linear dose response models. In the present study, we explored functional analysis techniques to characterize the pattern of platelet aggregation over time in response to nanoparticle induced perturbations. This has obviated the need to represent the pattern of aggregation by a single summary measure and allowed us to treat the entire aggregation profile over time, as the response. The modeling was performed in a flexible manner, without any imposition of shape restrictions on the curve, allowing smooth platelet aggregation over time. The use of a probabilistic framework not only allowed statistical prediction and inference of the aggregation signatures, but also provided a novel method for the estimation of higher order derivatives of the curve, thereby allowing plausible estimation of the extent and rate of platelet aggregation kinetics over time. In the present study, we focused on the estimated first derivative of the curve, obtained from the platelet optical aggregometric profile over time and used it to discern the underlying kinetics as well as to study the effects of ADP dosage and perturbation with gold nanoparticles. In addition, our method allowed the quantification of the extent of inter-individual signature variations. Our findings indicated several hidden features and showed a mixture of zero and first order kinetics interrupted by a metastable zero order ADP dose dependent process. In addition, we showed that the two first order kinetic constants were ADP dependent. However, we were able to perturb the overall kinetic pattern using gold nanoparticles, which resulted in autocatalytic aggregation with a higher aggregate mass and which facilitated the aggregation rate.

Does the safe childbirth checklist (SCC) program save newborn lives? Evidence from a realistic quasi-experimental study, Rajasthan, India.

BACKGROUND: The WHO Safe Childbirth Checklist (SCC) is a facility-based reminder tool focusing on essential care to improve quality of intrapartum care. We aimed to assess the impact of an intervention package using the SCC tool on facility-based stillbirths (SBs) and very early neonatal deaths (vENDs), in Rajasthan, India. METHODS: Within a quasi-experimental framework, districts were selected as intervention or comparison, matched by annual delivery load. The SCC tool was introduced at all district and sub-district level health facilities in the seven intervention districts, followed by monthly supportive supervision visits. In addition, supply of drugs and equipment were facilitated in all facilities (2013-2015). Facilities in the comparison districts provided routine care. Analysis included only the facilities with a specialized newborn care unit and information on all births was collected from facility registers. The primary outcome was the combined facility-based stillbirths and very early neonatal deaths (within 3-days after birth). We used generalized estimating equation with a Poisson regression model, with time as a linear term and adjusted for facility type in our model to estimate the effect of the intervention. [ClinicalTrials.gov: NCT01994304]. RESULTS: 77,239 births were recorded from 19 intervention facilities and 59,800 births from 15 comparison facilities. The intervention facilities reported 1621 stillbirths and 505 vENDs compared to 1390 stillbirths and 420 vENDs from the comparison facilities (RR 0.89, CI 0.81, 0.97). This translated to 11.16% (p = 0.01) reduction in total mortality (11.39% in stillbirths alone) in the intervention facilities. CONCLUSION: Our results suggest that the SCC program is an effective intervention that could potentially avert 40,000 intrapartum deaths in India annually, most of reduction coming from prevention of stillbirths.

Exploring the possibilities of dynamical quantum phase transitions in the presence of a Markovian bath.

We explore the possibility of dynamical quantum phase transitions (DQPTs) occurring during the temporal evolution of a quenched transverse field Ising chain coupled to a particle loss type of bath (local in Jordan-Wigner fermion space) using two versions of the Loschmidt overlap (LO), namely, the fidelity induced LO and the interferometric phase induced LO. The bath, on the one hand, dictates the dissipative evolution following a sudden quench and on the other, plays a role in dissipative mixed state preparation in the later part of the study. During a dissipative evolution following a sudden quench, no trace of DQPTs are revealed in both the fidelity and the interferometric phase approaches; however, remarkably the interferometric phase approach reveals the possibility of inter-steady state DQPTs in passage from one steady state to the other when the system is subjected to a quench after having reached the first steady state. We further probe the occurrences of DQPTs when the system evolves unitarily after being prepared in a mixed state of engineered purity by ramping the transverse field in a linear fashion in the presence of the bath. In this case though the fidelity approach fails to indicate any DQPT, the interferometric approach indeed unravels the possibility of occurrence of DQPTs which persists even up to a considerable loss of purity of the engineered initial state as long as a constraint relation involving the dissipative coupling and ramping time (rate) is satisfied. This constraint relation also marks the boundary between two dynamically inequivalent phases; in one the LO vanishes for the critical momentum mode (and hence DQPTs exist) while in the other no such critical mode can exist and hence the LO never vanishes.

Is socioeconomic segregation of the poor associated with higher premature mortality under the age of 60? A cross-sectional analysis of survey data in major Indian cities.

OBJECTIVES: Although urbanisation is generally associated with poverty reduction in low-income and middle-income countries, it also results in increased socioeconomic segregation of the poor. Cities with higher levels of socioeconomic segregation tend to have higher mortality rates, although the evidence is based on ecological associations. The paper examines whether socioeconomic segregation of the poor is associated with higher under-60 years ('premature') mortality risk in Indian cities and whether this association is confounded by contextual and compositional sociodemographic and socioeconomic factors. SETTING AND PARTICIPANTS: A population representative sample of over one million from 39 427 households living in 1876 urban wards within 59 Indian districts (cities) from the third (2008) District Level Household Survey (DLHS-3). PRIMARY OUTCOME AND OTHER MEASURES: The outcome was any death under the age of 60 reported by households in the preceding 4years of the DLHS-3. Socioeconomic segregation, estimated at the district (city) level, was measured using an isolation index of the poor and the index of dissimilarity. RESULTS: Poor households living in cities where the poor were more isolated had higher probabilities of premature mortality than poor households living in cities where the poor were less isolated. In contrast, it did not matter whether rich households lived in more or less socioeconomically segregated cities. A 1 SD increase in the isolation index was associated with an absolute increase of 1.1% in the probability of premature mortality for the poorest households. CONCLUSION: Increasing segregation of the poor may result in higher premature mortality. As low-income and middle-income countries become increasingly urbanised, there is a risk that this may lead to increased segregation of the poor as well as increased premature mortality.

Differential cataract blindness by sex in India: Evidence from two large national surveys.

AIMS: Women suffer disproportionately more from cataract blindness compared to males in low- and middle-income countries. Two large population-based surveys have been undertaken in India at an interval of 7 years and data from these surveys provided an opportunity to assess the trends in gender differentials in cataract blindness. MATERIALS AND METHODS: Data were extracted from the surveys to discern sex differences in cataract blindness. Multivariate analysis was performed to adjust for confounders and their impact on gender differences in cataract blindness. Blindness was defined as presenting vision <20/400 in the better eye, and a cataract blind person was defined as a blind person where the principal cause of loss of vision was cataract. RESULTS: Prevalence of cataract blindness was higher in females compared to males in both surveys. The odds of cataract blindness for females did not change over time as observed in the surveys (1999-2001 and 2006-2007). Adjusted odds ratio from logistic regression analysis revealed that females continued to be at a higher risk of cataract blindness. CONCLUSIONS: Sex differences continued in India in relation to cataract blindness despite the gains made by the national program.

Human resources, patient load, and infrastructure at institutions providing diabetic care in India: The India 11-city 9-state study.

BACKGROUND: There is a lack of information on the practice patterns and available human resources and services for screening for eye complications among persons with diabetes in India. OBJECTIVES: The study was undertaken to document existing health care infrastructure and practice patterns for managing diabetes and screening for eye complications. METHODS: This cross-sectional, hospital-based survey was conducted in 11 cities where public and private diabetic care providers were identified. Both multispecialty and standalone diabetic care facilities were included. A semi-structured questionnaire was administered to senior representative(s) of each institution to evaluate parameters using the World Health Organization health systems framework. RESULTS: We interviewed physicians in 73 hospitals (61.6% multispecialty hospitals; 38.4% standalone clinics). Less than a third reported having skilled personnel for direct ophthalmoscopy. About 74% had provision for glycated hemoglobin testing. Only a third had adequate vision charts. Printed protocols on management of diabetes were available only in 31.5% of the facilities. Only one in four facilities had a system for tracking diabetics. Half the facilities reported having access to records from the treating ophthalmologists. Direct observation of the services provided showed that reported figures in relation to availability of patient support services were overestimated by around 10%. Three fourths of the information sheets and half the glycemia monitoring cards contained information on the eye complications and the need for a regular eye examination. CONCLUSIONS: The study highlighted existing gaps in service provision at diabetic care centers in India.

Perceptions and practices related to diabetes reported by persons with diabetes attending diabetic care clinics: The India 11-city 9-state study.

BACKGROUND: India has the second largest population of persons with diabetes and a significant proportion has poor glycemic control and inadequate awareness of management of diabetes. OBJECTIVES: Determine the level of awareness regarding management of diabetes and its complications and diabetic care practices in India. METHODS: The cross-sectional, hospital-based survey was conducted in 11 cities where public and private providers of diabetic care were identified. At each diabetic care facility, 4-6 persons with diabetes were administered a structured questionnaire in the local language. RESULTS: Two hundred and eighty-five persons with diabetes were interviewed. The mean duration since diagnosis of diabetes was 8.1 years (standard deviation ± 7.3). Half of the participants reported a family history of diabetes and 41.7% were hypertensive. Almost 62.1% stated that they received information on diabetes and its management through interpersonal channels. Family history (36.1%), increasing age (25.3%), and stress (22.8%) were the commonest causes of diabetes reported. Only 29.1% stated that they monitored their blood sugar levels at home using a glucometer. The commonest challenges reported in managing diabetes were dietary modifications (67.4%), compliance with medicines (20.5%), and cost of medicines (17.9%). Around 76.5% were aware of complications of diabetes. Kidney failure (79.8%), blindness/vision loss (79.3%), and heart attack (56.4%) were the commonest complications mentioned. Almost 67.7% of the respondents stated that they had had an eye examination earlier. CONCLUSIONS: The findings have significant implications for the organization of diabetes services in India for early detection and management of complications, including eye complications.

Eye care infrastructure and human resources for managing diabetic retinopathy in India: The India 11-city 9-state study.

BACKGROUND: There is a paucity of information on the availability of services for diagnosis and management of diabetic retinopathy (DR) in India. OBJECTIVES: The study was undertaken to document existing healthcare infrastructure and practice patterns for managing DR. METHODS: This cross-sectional study was conducted in 11 cities and included public and private eye care providers. Both multispecialty and stand-alone eye care facilities were included. Information was collected on the processes used in all steps of the program, from how diabetics were identified for screening through to policies about follow-up after treatment by administering a semistructured questionnaire and by using observational checklists. RESULTS: A total of 86 eye units were included (31.4% multispecialty hospitals; 68.6% stand-alone clinics). The availability of a dedicated retina unit was reported by 68.6% (59) facilities. The mean number of outpatient consultations per year was 45,909 per responding facility, with nearly half being new registrations. A mean of 631 persons with sight-threatening-DR (ST-DR) were registered per year per facility. The commonest treatment for ST-DR was laser photocoagulation. Only 58% of the facilities reported having a full-time retina specialist on their rolls. More than half the eye care facilities (47; 54.6%) reported that their ophthalmologists would like further training in retina. Half (51.6%) of the facilities stated that they needed laser or surgical equipment. About 46.5% of the hospitals had a system to track patients needing treatment or for follow-up. CONCLUSIONS: The study highlighted existing gaps in service provision at eye care facilities in India.

Perception of care and barriers to treatment in individuals with diabetic retinopathy in India: 11-city 9-state study.

BACKGROUND: Diabetic retinopathy is a leading cause of visual impairment. Low awareness about the disease and inequitable distribution of care are major challenges in India. OBJECTIVES: Assess perception of care and challenges faced in availing care among diabetics. MATERIALS AND METHODS: The cross-sectional, hospital based survey was conducted in eleven cities. In each city, public and private providers of eye-care were identified. Both multispecialty and standalone facilities were included. Specially designed semi-open ended questionnaires were administered to the clients. RESULTS: 376 diabetics were interviewed in the eye clinics, of whom 62.8% (236) were selected from facilities in cities with a population of 7 million or more. The mean duration of known diabetes was 11.1 (±7.7) years. Half the respondents understood the meaning of adequate glycemic control and 45% reported that they had visual loss when they first presented to an eye facility. Facilities in smaller cities and those with higher educational status were found to be statistically significant predictors of self-reported good/adequate control of diabetes. The correct awareness of glycemic control was significantly high among attending privately-funded facilities and higher educational status. Self-monitoring of glycemic status at home was significantly associated with respondents from larger cities, privately-funded facilities, those who were better educated and reported longer duration of diabetes. Duration of diabetes (41%), poor glycemic control (39.4%) and age (20.7%) were identified as the leading causes of DR. The commonest challenges faced were lifestyle/behavior related. CONCLUSIONS: The findings have significant implications for the organization of diabetes services in India.

Clinical outcomes of xeno-free autologous cultivated limbal epithelial transplantation: a 10-year study.

PURPOSE: Ocular burns can damage the corneal epithelial stem cells located at the limbus. This study evaluated the efficacy of xeno-free autologous cell-based treatment of limbal stem cell deficiency. METHODS: This retrospective study included 200 patients, above 8 years of age, with clinically diagnosed unilateral total limbal stem cell deficiency due to ocular surface burns treated between 2001 and 2010. A small limbal biopsy was obtained from the unaffected eye. The limbal epithelial cells were expanded ex vivo on human amniotic membrane for 10-14 days using a xeno-free explant culture system. The resulting cultured epithelial monolayer and amniotic membrane substrate were transplanted on to the patient's affected eye. Postoperative corneal surface stability, visual improvement and complications were objectively analysed. RESULTS: A completely epithelised, avascular and clinically stable corneal surface was seen in 142 of 200 (71%) eyes at a mean follow-up of 3 ± 1.6 (range: 1-7.6) years. A two-line improvement in visual acuity, without further surgical intervention, was seen in 60.5% of eyes. All donor eyes remained healthy. CONCLUSIONS: Autologous cultivated limbal epithelial transplantation using a xeno-free explant culture technique was effective in long-term restoration of corneal epithelial stability and improvement of vision in eyes with ocular surface burns.