Dynamics of magnetization at infinite temperature in a Heisenberg spin chain.

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.

Stable quantum-correlated many-body states through engineered dissipation.

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

Formation of robust bound states of interacting microwave photons.

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Restrictions on contraceptive services for unmarried youth: a qualitative study of providers' beliefs and attitudes in India.

Sexual and reproductive health (SRH) of unmarried youth is an important issue, particularly in Indian society, where premarital sex is socially restricted. It is an uncomfortable subject for most people, including healthcare providers, who are responsible for catering to the reproductive health needs of youth. This is because of the prevailing social norms, where sex outside marriage is discouraged and stigmatised. These social norms give importance to virginity, and children outside marriage are not welcome. The present qualitative study was conducted in public health facilities (primary and secondary) to explore the attitudes of healthcare providers in providing contraceptive services to unmarried youth. In-depth interviews were conducted with family planning (FP) service providers (frontline healthcare workers [ASHAs] nurses and FP counsellors) between October 2017 and September 2018. Almost a quarter of the providers were either hesitant or against providing contraceptives to unmarried youth. Providers stated that they preferred emergency contraceptive pills for unmarried girls if they had already engaged in unprotected sex. Providers expressed strong personal views against premarital sex because they believed it was against existing social norms. Some providers were concerned about the possible negative reactions of the community if they recommended any contraceptive to unmarried youth. A few providers even considered it illegal to provide contraceptives to unmarried youth, though there is no such law in the country. Findings further indicated that though the country had launched programmes for improving adolescents and youth SRH, service providers were still conflicted between medical eligibility and social beliefs.

Noise-resilient edge modes on a chain of superconducting qubits.

Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model, which exhibits nonlocal Majorana edge modes (MEMs) with [Formula: see text] parity symmetry. We find that any multiqubit Pauli operator overlapping with the MEMs exhibits a uniform late-time decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This characteristic allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Furthermore, the MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism. Our work elucidates the complex interplay between noise and symmetry-protected edge modes in a solid-state environment.

Optimization of external (in air) particle induced gamma-ray emission (PIGE) methodology for rapid, non-destructive, and simultaneous quantification of fluorine, sodium, and phosphorus in nuclear waste immobilization matrices.

External (in air) PIGE methodology has been optimized for rapid quantification of fluorine, sodium, and phosphorus in fluorapatite waste immobilization matrices for Molten Salt Reactor (MSR). The present methodology addresses the issue of distinguishing hydroxyapatite and fluorapatite phases through XRD patterns. Fluctuations in proton beam current have been monitored by prompt γ-ray from nitrogen (2312 keV) through 14N(p,p'γ)14N nuclear reaction and have successfully been applied as a new method of current normalization, for the first time, in external PIGE method with lower Compton background and negligible spectral interference. The proposed method was also compared with the earlier method of current normalization using 165 keV (181T(p,p'γ)181Ta) from the Tantalum window used for obtaining "in air" beam. For the fluctuation of beam current within 5-10 nA, nitrogen from air can be used as an effective current normalizer. Moreover, the uncertainty (within ±3%) was also improved in the present method of current normalization. Fluorine can be estimated from trace to major concentrations using 197 keV (19F(p,p'γ)19F) γ-ray with highest sensitivity as compared to other prompt γ-rays (110 keV and 1236 keV). The matrix effect in PIGE was also eliminated by diluting the sample in cellulose. The method was validated using the synthetic samples (Ca10(PO4)6F2, Na2Eu2Ca6(PO4)6F2, Na1.5Eu1.5Ca7(PO4)6F2, Na1Eu1Ca8(PO4)6F2, Na0.5Eu0.5Ca9(PO4)6F2, and Sr10(PO4)6F2). The results were found to be satisfactory and in good agreement with stoichiometric amounts. Elements such as Na, P, and Ca were determined in the fluorapatite samples using PIGE and EDXRF, respectively, as a part of chemical quality control. Moreover, in external PIGE, 1266 keV γ-ray (31P(p,p'γ)31P) provides more accurate P concentrations in the samples.

Efficacy of Eutectic Mixture of Local Anesthetic Cream and Vibrator Device in Pain Reduction during Peripheral Venous Cannulation in a Tertiary Care Center of Central Nepal.

Background Venous cannulation is a commonly performed procedure which often leads to patient anxiety. Application of a vibrator device and or prior use of topical anesthetics are proven methods to decrease associated pain. Objective To compare the clinical efficacy of prior use of Eutectic Mixture of Local Anesthetic (EMLA) cream and vibrator device in pain reduction during peripheral venous cannulation. Method A true experimental study was conducted in November 2019 among 78 patients aged 20-60 years receiving peripheral cannulation at operation theatre. They were included using consecutive sampling and sorted to interventional and noninterventional group using simple random sampling lottery method. Participants in the non-interventional group received peripheral cannulation using routine technique whereas participants in the interventional group received topical Eutectic Mixture of Local Anesthetic cream or vibrator device prior to cannulation. Perceived post cannulation pain intensity was measured using numerical pain rating scale. Kruskal-Wallis test was used for data comparison. Result The mean age of the participants was 40.57 ± 12.5 years. The median pain score of Eutectic Mixture of Local Anesthetic cream, vibrator and no intervention was 3, 3 and 6 respectively. The reduction in median pain intensity was significantly greater with topical anesthetic cream and vibrator device when compared to the noninterventional group (p < 0.05). Conclusion Prior interventions with Eutectic Mixture of Local Anesthetic or vibrator device are useful in reducing pain intensity during peripheral venous cannulation. Routine use of these in day to day practice could be a part of standard nursing care practice.

Preterm Birth, Exasperation to the South Asian Countries.

When a child is born before 37 weeks or 259 days of pregnancy, it is termed as preterm birth. Pre-term birth is prevalent in both developed and developing country. However, difference lies in their survival. In lower and middle income countries, most preterm babies die due to lack of even simple interventions. India ranks top in the world for deaths due to complications of preterm birth. Similarly, other South Asian countries, Pakistan, Bangladesh, Afghanistan and Nepal rank 3rd, 6th, 9th and 20th in the same. The aim of this review paper is to provide a landscape analysis on the burden of pre-term birth and challenges in the context of South Asian region. Databases such as PubMed, Scopus and Google Scholar were searched from 2000 to 2020 and 27 articles are included in the study. It was found that pre-term birth causes huge burden in the form of morbidity, mortality as well as socio economic losses. Preterm birth was associated with increased sepsis, cardiovascular disease, respiratory illness, hypothermia, neurological and gastrointestinal complications. South Asian countries have distinct challenges in eliminating or reducing preterm births which are: poor quality health surveillance data, inadequate trained health workforce, insufficient finance and funding, service delivery and other methodological challenges. Ending pre-term birth is important as it is directly related to Sustainable Development Goal 3. Therefore, there should be increase in priority given to increase financing, quality data gathering, adopting innovative measures as well as joint efforts of all the sectors to control the pre-term birth.

TB disease patterns by HIV and diabetes status.

BACKGROUND: TB is commonly categorised as pulmonary (PTB) or extrapulmonary TB (EPTB). Knowledge of TB disease patterns (PTB and/or EPTB) and determining risk factors remains limited.METHODS: This was a prospective cohort study using point-of-care ultrasound (POCUS) in Indian patients with presumed TB. Clinical and imaging data were used to develop refined case definitions for PTB, concurrent PTB and EPTB (PTB + EPTB) and EPTB without PTB (EPTB). These groups were analysed by HIV (HIV+/-) and diabetes mellitus (DM+/-) status.RESULTS: Of 172 HIV-/DM- patients with TB, 48% had PTB, 23% PTB + EPTB and 29% had EPTB, totalling 52% with any EPTB (PTB + EPTB or EPTB). In HIV+/DM- patients with TB (n = 35), 6% had PTB, 40% had PTB + EPTB and 54% had EPTB, accounting for 94% with EPTB. In HIV-/DM+ patients with TB (n = 61), 61% had PTB, 28% had PTB + EPTB and 11% had EPTB, representing 39% with EPTB.CONCLUSION: Refined case definitions revealed high proportions of EPTB even without HIV or DM. HIV further altered the TB disease pattern towards EPTB and DM towards PTB. Therefore, the dichotomy between PTB or EPTB does not represent the actual spectrum of TB disease. EPTB should receive higher priority in research and clinical practice.

Utilization of accelerator and reactor based nuclear analytical techniques for chemical characterization of automobile windshield glass samples and potential of statistical analyses using trace elements towards glass forensics.

Glass forensics is an important area in forensic crime investigations, wherein glass origin or source finding is necessary mainly through chemical composition. In the present work, Nuclear Analytical Techniques namely external (in air) Particle Induced Gamma-ray Emission (PIGE) and Instrumental Neutron Activation Analysis (INAA) were utilized for complete chemical characterization of twenty-five "as received" windshield glass samples of six car manufactures. Concentrations of four major elements (Si, Na, Mg and Al) by PIGE using proton beam and nineteen elements including sixteen trace elements by INAA using research reactor neutrons were determined. Both the methods were validated by analysing matrix matched glass certified (standard) reference materials. Trace elemental concentrations including rare earth elements (REEs) and ternary plot using concentrations of major, transition elements and REEs were utilized to obtain preliminary grouping of the analyzed glass samples. Statistical tools namely K-mean, Cluster Analysis and Principal Component Analysis (PCA) using trace elemental concentrations were utilized for grouping studies, important for forensic applications. Among these statistical analysis techniques, PCA results confirmed that windshield glasses from six manufactures clearly belong to six different groups.

Vitamin D repletion in primary hyperparathyroid patients undergoing parathyroidectomy leads to reduced symptomatic hypocalcaemia and reduced length of stay: a retrospective cohort study.

INTRODUCTION: Vitamin D deficiency co-exists with and can confuse the diagnosis of primary hyperparathyroidism (PHPT). Vitamin D replete (VDR) status may prevent significant postparathyroidectomy hypocalcaemia; however, reports from previous studies are conflicting. This study aimed to assess differences in early and/or late postoperative hypocalcaemia and length of stay (LOS) postparathyroidectomy between VDR and vitamin D non-replete (VDNR) PHPT patients. METHODS: This was a retrospective cohort study of a prospectively maintained single surgeon operative database. All records of patients who underwent parathyroidectomy over a four-year period (July 2014 to December 2018) were extracted. Data were collected on vitamin D and corrected calcium levels pre- and postoperatively as well as postoperative complications and LOS. RESULTS: On presentation, there were 91 (47.9%) VDR and 99 (52.1%) VDNR patients. Following vitamin D therapy there were 148 (77.9%) VDR and 42 (22.1%) VDNR. The multivariate analysis showed that vitamin D status was the only significant factor impacting on the hypocalcaemia symptoms (OR 4.9, 95% CI 1.8-13.7, p = 0.002) and the most significant factor for the calcium supplementation (OR 6.5, 95% CI 2.1-19.4, p = 0.001). Bilateral neck exploration was associated with increased likelihood of transient hypocalcaemia (p = 0.007) but no other post-op complication. Median LOS was significantly shorter for VDR (1 day) versus VDNR (1.5 days) patients (p = 0.001). CONCLUSION: There is a statistically significant increased likelihood of postoperative hypocalcaemia symptoms, requirement for calcium supplements and increased LOS in VDNR patients. This study suggests optimising preoperative vitamin D status improves patient experience and could reduce healthcare costs.

Prevalence and Associated Factors of Cesarean Section in Dhulikhel Hospital, Kathmandu University Hospital.

Background The Cesarean Section (CS) is a major obstetric life-saving procedure used to avoid pregnancy and childbirth complications. Cesarean sections are becoming more popular across the world, as well as in Nepal. Objective To assess the prevalence of cesarean section and its associated factors among women in Dhulikhel, Nepal. Method A cross-sectional study was conducted where 1246 pregnant women of age 15-45 years, admitted and delivered in hospital, were selected through purposive sampling technique and interviewed using structured questionnaires in Dhulikhel Hospital, Kathmandu University Hospital, Kavre, Nepal. Result The prevalence of cesarean section among women was 39.7% where the most common indication was previous cesarean section with scar tenderness, 27.9%. Half of the participants, i.e. 50.6%, were primigravida. Majority of women, 97.5% had done their antenatal checkup and among them 74.8% had their checkup in Dhulikhel Hospital, Kathmandu University Hospital. Most of them, i.e.76.2% had emergency cesarean section and 69.5% had primary cesarean section. Women of the age group 30-45 years (AOR=2.23) and women with higher secondary education level (AOR=2.03) were two times more likely to perform cesarean section. Women involved in service (AOR=1.37) and business (AOR=1.23) had greater odds of performing cesarean section than homemakers. Women giving birth to infants weighing 3.51- 5.00 kg were more likely to perform cesarean section (AOR=1.33). Conclusion The prevalence of cesarean section is noticeably high where the educated, employed and higher aged women are more inclined to cesarean section. More obstetric factors could be explored to determine the rise in cesarean section in Nepal which can help in decision making for clinicians.

Antibiotic resistance in patients with chronic ear discharge awaiting surgery in Nepal.

SETTING: Biratnagar Eye Hospital, Biratnagar, Nepal, which offers ear surgery for chronic suppurative otitis media (CSOM). OBJECTIVE: In patients with CSOM awaiting surgery, to determine the 1) sociodemographic characteristics 2) bacterial isolates and their antibiotic resistance patterns and 3) characteristics of those refused surgery, including antibiotic resistance. DESIGN: A cohort study using hospital data, January 2018-January 2020. RESULTS: Of 117 patients with CSOM and awaiting surgery, 64% were in the 18-35 years age group, and 79% were cross-border from India. Of 118 bacterial isolates, 80% had Pseudomonas aeruginosa and 16% had Staphylococcus aureus. All isolates showed multidrug resistance to nine of the 12 antibiotics tested. The lowest antibiotic resistance in P. aeruginosa was for vancomycin (29%) and moxifloxacin (36%), and for S. aureus, this was vancomycin (9%) and amikacin (17%). Fourteen (12%) patients underwent surgery: myringoplasty (n = 7, 50%), cortical mastoidectomy with tympanostomy (n = 4, 29%) and modified radical mastoidectomy (n = 3, 21%). Those infected with P. aeruginosa and with resistance to over six antibiotics were significantly more likely to be refused for surgery. CONCLUSION: Patients awaiting ear surgery were predominantly infected with multidrug-resistant P. aeruginosa and were consequently refused surgery. This study can help inform efforts for improving surgical uptake and introducing cross-border antimicrobial resistance surveillance.

LIEU: Hôpital ophtalmologique de Biratnagar, Népal, qui propose des interventions chirurgicales de l'oreille aux patients atteints d'otite moyenne chronique suppurée (CSOM). OBJECTIF: Déterminer 1) les caractéristiques sociodémographiques, 2) les isolats bactériens et leurs profils de résistance aux antibiotiques et 3) les caractéristiques des patients se voyant refuser la chirurgie (dont résistance aux antibiotiques) chez les patients atteints de CSOM en attente de chirurgie. MÉTHODE: Étude de cohorte réalisée à l'aide de données hospitalières, janvier 2018-janvier 2020. RÉSULTATS: Sur les 117 patients atteints de CSOM en attente de chirurgie, 64% appartenaient à la tranche d'âge des 18­35 ans et 79% étaient des patients transfrontaliers en provenance d'Inde. Sur 118 isolats bactériens, 80% étaient des isolats de Pseudomonas aeruginosa et 16% de Staphylococcus aureus. Tous les isolats ont montré une résistance à neuf des 12 antibiotiques testés. Les plus faibles résistances chez P. aeruginosa étaient celles à la vancomycine (29%) et à la moxifloxacine (36%). Pour S. aureus, il s'agissait de celles à la vancomycine (9%) et à l'amikacine (17%). Quatorze (12%) patients ont subi une intervention chirurgicale : myringoplastie (n = 7, 50%), mastoïdectomie corticale avec tympanotomie (n = 4, 29%) et mastoïdectomie radicale modifiée (n = 3, 21%). Les patients infectés par P. aeruginosa avec une résistance à plus de six antibiotiques étaient significativement plus susceptibles de se voir refuser la chirurgie. CONCLUSION: Les patients en attente de chirurgie de l'oreille étaient principalement infectés par un isolat multirésistant de P. aeruginosa, et se sont donc vu refuser la chirurgie. Cette étude peut permettre d'orienter les efforts visant à améliorer le taux de chirurgies réalisées et à mettre en place une surveillance transfrontalière des résistances antimicrobiennes.

Clinical profile of Thrombocytopenia in Acute Febrile Illnesses; a hospital-based study.

Background Thrombocytopenia is a common haematological abnormality noted in clinical practice, however, it can be missed in cases where specific investigations are not asked for. Acute Febrile Illness with thrombocytopenia is a diagnostic and therapeutic challenge, as thrombocytopenia has an inverse relation to mortality and morbidity in various febrile illnesses. Vector-borne and zoonotic diseases (like malaria, dengue, scrub typhus, and leptospirosis), infections and sepsis are some of the common causes of fever with thrombocytopenia. Objective To identify the causes of fever with thrombocytopenia, assess the clinical complications associated with febrile thrombocytopenia, and overall study the clinical profile of thrombocytopenia in a tertiary care hospital Method Medical records of all adult patients, admitted to a tertiary level hospital, with fever and thrombocytopenia (platelet count < 1,00,000 /mm3 ) were assessed (from October 2009 to March 2011). Detailed case history, general physical examination findings, routine and specific examinations were recorded according to a pre-decided format. Data were analysed using SPSS 16.0 Result Acute febrile illness with thrombocytopenia was most commonly seen in Dengue patients. Headache and arthralgia were more commonly encountered in scrub typhus. Platelet transfusions were necessitated in a large number of patients, especially in scrub typhus. Malaria patients had the highest mortality rate. Conclusion Acute Febrile Illnesses (AFI) are of varied origins, and proper diagnosis is imperative. The degree of thrombocytopenia in infections has a prognostic value. It can also help in differential diagnosis and clear identification of aetiology of acute febrile illnesses. Timely identification and management of thrombocytopenia in acute febrile illness can positively impact the overall patient outcome.

Mapping of a novel major effect Hessian fly field partial-resistance locus in southern soft red winter wheat line LA03136E71.

KEY MESSAGE: Hessian fly resistance has centralized around resistance loci that are biotype specific. We show that field resistance is evident and controlled by a single locus on chromosome 7D. Hessian flies (Mayetiola destructor Say) infest and feed upon wheat (Triticum aestivum L) resulting in significant yield loss. Genetically resistant cultivars are the most effective method of Hessian fly management. Wheat breeders in the southern USA have observed cultivars exhibiting a "field resistance" to Hessian fly that is not detectable by greenhouse assay. The resistant breeding line "LA03136E71" and susceptible cultivar "Shirley" were crossed to develop a population of 200 random F4:5 lines using single seed descent. The population was evaluated in a total of five locations in North Carolina during the 2019, 2020, and 2021 seasons. A subsample of each plot was evaluated for the total number of tillers, number of infested tillers, and total number of larvae/pupae. From these data, the percent infested tillers, number of larvae/pupae per tiller, and the number of larvae/pupae per infested tiller were estimated. In all within and across environment combinations for all traits recorded, the genotype effect was significant (p < 0.05). Interval mapping identified a single large effect QTL distally on the short arm of chromosome 7D for all environment-trait combinations. This locus was identified on a chromosome where no other Hessian fly resistance/tolerance QTL has been previously identified. This novel Hessian fly partial-resistance QTL is termed QHft.nc-7D. Fine mapping must be conducted in this region to narrow down the causal agents responsible for this trait, and investigation into the mode of action is highly suggested.

Probing the solute-drag effect and its role in stabilizing the orthorhombic phase in bulk La-doped HfO2 by X-ray and gamma ray spectroscopy.

The recent observation of ferroelectricity in ultra thin films of hafnium oxide (HfO2) has been attributed to the orthorhombic (o) phase of HfO2 with space group Pca21. Although this oxide is polymorphic in nature, this polar o-phase is known to be stabilized in the doped thin film oxide. The objective of the present experiment is to stabilize the o-phases in La doped bulk polycrystalline HfO2 and investigate their evolution with the doping concentration through Time Differential Perturbed Angular Correlation (TDPAC), X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) measurements. The present work reports the presence of both the polar Pca21 phase and the antipolar Pbca phase at different La-concentrations. Two o-phases of HfO2 with space groups Pca21 and Pbca, difficult to distinguish by other complimentary methods, could be unambiguously identified by utilizing the atomic scale sensitivity of the electric field gradient (EFG) embedded in TDPAC spectroscopy. The determination of the oxidation state and the local environment of La-atoms by XANES and EXAFS measurements illuminates the microscopic role of the dopant in stabilizing the o-phase. The "solute drag model" proposes a critical crystallite size for the nucleation of the o-phase in bulk HfO2 and explains the role of the La-dopant in stabilizing the o-phase. Thus the present study shows the possibility of stabilizing the polar o-phase and hence attaining ferroelectricity in bulk HfO2 to augment the scope of future application for this ferroelectric device.

Adrenal Ganglioneuroma.

Adrenal ganglioneuromas are rare sympathetic differentiated tumors which originate from neural crest cells. These lesions are usually discovered incidentally on imaging and tend to be hormonally silent. Preoperative diagnosis of adrenal ganglioneuroma remains extremely challenging and the gold standard treatment is adrenalectomy. There is good prognosis after surgery without recurrence. We herein report a case of adrenal ganglioneuroma in a 15 year old female who presented with complaint of abdominal discomfort. Contrast Enhanced Computed Tomography abdomen showed a large septated hypodense right suprarenal mass which was echogenic on Ultrasonography. It showed T1 hypointense and T2 hyperintense signal on Magnetic Resonance Imaging of abdomen and pelvis. Excisional biopsy and histological examination of the mass was suggestive of adrenal ganglioneuroma. This report presents the clinical and radiological data for the rare tumor which would share some experience to facililate the diagnosis of adrenal ganglioneuroma.

Measuring gender norms about relationships in early adolescence: Results from the global early adolescent study.

INTRODUCTION: Gender norms are increasingly recognized as drivers of health and wellbeing. While early adolescence constitutes a critical window of development, there is limited understanding about how adolescents perceive gender relations across different cultural settings. This study used a mixed-method approach, grounded in the voices of young people around the world, to construct and test a cross-cultural scale assessing the perceptions of gender norms regulating romantic relationships between boys and girls in early adolescence. METHODS: The study draws on the Global Early Adolescent study (GEAS), a study focusing on gender norms and health related outcomes over the course of adolescence in urban poor settings worldwide. In-depth interviews were first conducted among approximately 200 adolescents between 10-14 years in seven sites across 4 continents to identify common scripts guiding romantic relations in early adolescence. These scripts were then transformed into a multidimensional scale. The scale was tested among 120 adolescents in each of 14 GEAS sites, followed by a second pilot among 75 adolescents in six sites. We evaluated the psychometric criteria of each sub-scale using principal component analysis, and parallel analysis, followed by exploratory factor analysis to guide the selection of a more parsimonious set of items. RESULTS: Results suggested a two-factor structure, consisting of an "adolescent romantic expectations" subscale and a "Sexual Double Standard" subscale. Both subscales yielded high internal validity in each site, with polychoric Cronbach alpha values above 0.70 with the exception of Kinshasa for the adolescent romantic expectations scale (0.64) and Hanoi for the sexual double standard scale (0.61). CONCLUSION: This study reveals common perceptions of gendered norms about romantic engagement in early adolescence, normative for both sexes, but socially valued for boys while devaluated for girls. The findings illustrate that social hierarchies of power in romantic relationships form early in adolescence, regardless of cultural setting.

Optimization of lithium content in LiFePO4 for superior electrochemical performance: the role of impurities.

Carbon coated Li x FePO4 samples with systematically varying Li-content (x = 1, 1.02, 1.05, 1.10) have been synthesized via a sol-gel route. The Li : Fe ratios for the as-synthesized samples is found to vary from ∼0.96 : 1 to 1.16 : 1 as determined by the proton induced gamma emission (PIGE) technique (for Li) and ICP-OES (for Fe). According to Mössbauer spectroscopy, sample Li1.05FePO4 has the highest content (i.e., ∼91.5%) of the actual electroactive phase (viz., crystalline LiFePO4), followed by samples Li1.02FePO4, Li1.1FePO4 and LiFePO4; with the remaining content being primarily Fe-containing impurities, including a conducting FeP phase in samples Li1.02FePO4 and Li1.05FePO4. Electrodes based on sample Li1.05FePO4 show the best electrochemical performance in all aspects, retaining ∼150 mA h g-1 after 100 charge/discharge cycles at C/2, followed by sample Li1.02FePO4 (∼140 mA h g-1), LiFePO4 (∼120 mA h g-1) and Li1.10FePO4 (∼115 mA h g-1). Furthermore, the electrodes based on sample Li1.05FePO4 retain ∼107 mA h g-1 even at a high current density of 5C. Impedance spectra indicate that electrodes based on sample Li1.05FePO4 possess the least charge transfer resistance, plausibly having influence from the compositional aspects. This low charge transfer resistance is partially responsible for the superior electrochemical behavior of that specific composition.