Orbital character of the spin-reorientation transition in TbMn6Sn6.

Ferromagnetic (FM) order in a two-dimensional kagome layer is predicted to generate a topological Chern insulator without an applied magnetic field. The Chern gap is largest when spin moments point perpendicular to the kagome layer, enabling the capability to switch topological transport properties, such as the quantum anomalous Hall effect, by controlling the spin orientation. In TbMn6Sn6, the uniaxial magnetic anisotropy of the Tb3+ ion is effective at generating the Chern state within the FM Mn kagome layers while a spin-reorientation (SR) transition to easy-plane order above TSR = 310 K provides a mechanism for switching. Here, we use inelastic neutron scattering to provide key insights into the fundamental nature of the SR transition. The observation of two Tb excitations, which are split by the magnetic anisotropy energy, indicates an effective two-state orbital character for the Tb ion, with a uniaxial ground state and an isotropic excited state. The simultaneous observation of both modes below TSR confirms that orbital fluctuations are slow on magnetic and electronic time scales < ps and act as a spatially-random orbital alloy. A thermally-driven critical concentration of isotropic Tb ions triggers the SR transition.

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.

Research during COVID-19 Pandemic: Perspectives from the Ethics Committees of a Lower Middle Income Country.

The pandemic of Coronavirus Disease 2019 (COVID-19) has created paradoxically a good opportunity globally to conduct research in the field of health and social science, and a Lower Middle-Income Country (LMIC) like Nepal is not an exception in this regard. During this ongoing pandemic, the Ethical Review Board (ERB) of Nepal Health Research Council (NHRC) has received numerous research proposals regarding COVID-19. As its main responsibility is to ensure participants' safety, at the same time maintaining the scientific standard of research, the ERB has meticulously gone through all the proposals received so far. During this situation of a health emergency, the ERB of NHRC has had a different experience compared to the usual time. Its strength, weakness, opportunities, and threats have been like never before.

Quantum limit transport and destruction of the Weyl nodes in TaAs.

Weyl fermions are a recently discovered ingredient for correlated states of electronic matter. A key difficulty has been that real materials also contain non-Weyl quasiparticles, and disentangling the experimental signatures has proven challenging. Here we use magnetic fields up to 95 T to drive the Weyl semimetal TaAs far into its quantum limit, where only the purely chiral 0th Landau levels of the Weyl fermions are occupied. We find the electrical resistivity to be nearly independent of magnetic field up to 50 T: unusual for conventional metals but consistent with the chiral anomaly for Weyl fermions. Above 50 T we observe a two-order-of-magnitude increase in resistivity, indicating that a gap opens in the chiral Landau levels. Above 80 T we observe strong ultrasonic attenuation below 2 K, suggesting a mesoscopically textured state of matter. These results point the way to inducing new correlated states of matter in the quantum limit of Weyl semimetals.

Prevalence and Predictors of Alcohol Consumption among the Squatter of Kathmandu Valley.

BACKGROUND: Alcohol consumption has grown up sharply over the past decades in Nepal. Conversely, little is known about this phenomenon among the urban poor. We assessed pattern, frequency, context, and type of alcohol consumption among the urban poor of Nepal. METHODS: We executed a cross-sectional study, taking 422 households from four squatter settlements of Kathmandu Valley. Modified Nepalese version standard questionnaire was used for data collection. Data was objectively analyzed in SPSS full version 19. RESULTS: The study reported 39.81% (95% CI: 32.41-47.21) current drinkers, with male (65.99%, 95% CI: 57.85-74.13) outnumbering female (16.89%, 95% CI: 4.98-28.80). One out of ten drinkers drank daily (male: 13.08%, female: 13.16%). A third (30.36%) of all current drinkers acknowledged drinking more than one type of alcohol (male: 28.46%, female: 36.84%). Nearly half (47.60%) of the drinkers drank in social gathering (male: 47.90%, female: 47.60%). Home was the place of drinking for nearly one-fifth (18.60%) of the drinkers. Males most commonly drank alcohol with their friends (34.60%), whereas female drank with family members (25.60%). Nearly half of the drinkers drank during evening hour (45.24%). Multivariable analysis detected likelihood of drinking 5.86 times (95% CI: 2.50-13.72) in male and 3.16 times (95% CI: 1.39-7.13) in those with family history of alcohol. CONCLUSIONS: We found high prevalence of alcohol consumption than the national average among the urban poor with a marked gender difference by pattern. Gender sensitive alcohol prevention and control programs need a greater start.

Anomalous electronic structure and magnetoresistance in TaAs2.

The change in resistance of a material in a magnetic field reflects its electronic state. In metals with weakly- or non-interacting electrons, the resistance typically increases upon the application of a magnetic field. In contrast, negative magnetoresistance may appear under some circumstances, e.g., in metals with anisotropic Fermi surfaces or with spin-disorder scattering and semimetals with Dirac or Weyl electronic structures. Here we show that the non-magnetic semimetal TaAs2 possesses a very large negative magnetoresistance, with an unknown scattering mechanism. Density functional calculations find that TaAs2 is a new topological semimetal [ℤ2 invariant (0;111)] without Dirac dispersion, demonstrating that a negative magnetoresistance in non-magnetic semimetals cannot be attributed uniquely to the Adler-Bell-Jackiw chiral anomaly of bulk Dirac/Weyl fermions.

Magnetotransport of single crystalline YSb.

We report magnetic field dependent transport measurements on a single crystal of cubic YSb together with first principles calculations of its electronic structure. The transverse magnetoresistance does not saturate up to 9 T and attains a value of 75 000% at 1.8 K. The Hall coefficient is electron-like at high temperature, changes sign to hole-like between 110 and 50 K, and again becomes electron-like below 50 K. First principles calculations show that YSb is a compensated semimetal with a qualitatively similar electronic structure to that of isostructural LaSb and LaBi, but with larger Fermi surface volume. The measured electron carrier density and Hall mobility calculated at 1.8 K, based on a single band approximation, are [Formula: see text] cm(-3) and [Formula: see text] cm(2) Vs(-1), respectively. These values are comparable with those reported for LaBi and LaSb. Like LaBi and LaSb, YSb undergoes a magnetic field-induced metal-insulator-like transition below a characteristic temperature T m, with resistivity saturation below 13 K. Thickness dependent electrical resistance measurements show a deviation of the resistance behavior from that expected for a normal metal; however, they do not unambiguously establish surface conduction as the mechanism for the resistivity plateau.

'Hard' crystalline lattice in the Weyl semimetal NbAs.

We report the effect of hydrostatic pressure on the magnetotransport properties of the Weyl semimetal NbAs. Subtle changes can be seen in the ρ(xx)(T) profiles with pressure up to 2.31 GPa. The Fermi surfaces undergo an anisotropic evolution under pressure: the extremal areas slightly increase in the k(x)-k(y) plane, but decrease in the k(z)-k(y)(k(x)) plane. The topological features of the two pockets observed at atmospheric pressure, however, remain unchanged at 2.31 GPa. No superconductivity can be seen down to 0.3 K for all the pressures measured. By fitting the temperature dependence of specific heat to the Debye model, we obtain a small Sommerfeld coefficient γ(0) = 0.09(1) mJ (mol·K(2))(-1) and a large Debye temperature, Θ(D) = 450(9) K, confirming a 'hard' crystalline lattice that is stable under pressure. We also studied the Kadowaki-Woods ratio of this low-carrier-density massless system, R(KW) = 3.2 × 10(4) µΩ cm mol(2) K(2) J(-2). After accounting for the small carrier density in NbAs, this R(KW) indicates a suppressed transport scattering rate relative to other metals.

Access to Drugs and Out of Pocket Expenditure in Primary Health Facilities.

BACKGROUND: The Government of Nepal promulgated health as a human right via Interim constitution and implemented Free Health Service Program in 2008 as a commitment to universalize basic health care services. So, the aim of this study was to understand reported access to medicine and health care services received by outpatients in public primary facilities. METHODS: The study followed cross sectional study design. Two hundred and thirty-four For data 234 out patients were interviewed on the day of the field visit in March and October 2014 across 28 primary health facilities of seven purposively selected districts representing three ecological belts and five development regions of the country. RESULTS: Our study revealed that the average number of medicines prescribed per patient was 2.65 per case in primary public health facilities, of which 91.2% were dispensed. Around 86.6% dispensed medicines were appropriately labeled and 84% of outpatients had proper knowledge of dosage and timing of medicine use. Around 55.6% of outpatients purchased some or all prescribed medicines from nearby private facilities which were not available in public facilities. Around 40% of them travelled more than half an hour to reach the facility. CONCLUSIONS: The gap in medicines prescribed and dispensed, Out of Pocket expenditure coupled with opportunity cost of travelling, appear as hurdles in access to basic health care services. So increasing free medicines list in public primary facilities with all round the year availability might answer major part of the problem.

Assessment of Knowledge Regarding Oral Hygiene among Parents of Pre-School Children Attending Pediatric Out Patient Department in Dhulikhel Hospital.

BACKGROUND: Level of knowledge regarding oral hygiene among the parents of pre-school children plays an important role on maintaining the good oral hygiene of their children. In Nepal, sufficient research has not been carried out on this area. OBJECTIVE: Objective of this study is to assess the level of knowledge on oral hygiene of preschool children's parents attending pediatric outpatient department in Dhulikhel Hospital. METHOD: A descriptive study was conducted from November 2012 to January 2013 among one hundred parents of preschool children visiting pediatrics outpatient department of Dhulikhel Hospital. Paper and pencil based semi structured questionnaire was used for collecting data. Questions related to demographic information and knowledge were asked. Thirty questions were used for assessing knowledge level. Knowledge score was calculated by allocating one point for each correct answer and zero point for each wrong answer. Analyzed data were presented in terms of numbers and percentages. Total knowledge scores were categorized based on percentage. Knowledge score was categorized on four group - exclusive intervals - namely-poor (0-40%), moderate (40-60%), good (60-80%) and excellent (80-100%). Mann-Whitney U test and Kruskal-Wallis test were applied to check significance difference and chisquare test was used to check association among different background characteristic. RESULT: It was found that 81% had moderate knowledge, 15% had poor knowledge and 4% had good knowledge about oral hygiene. Median knowledge score was found to be 15 with range 10 to 21. Following variables were found to be significant difference on knowledge category: Education status (p<0.001), education level (p= 0.041), past experience about oral health problem (p = 0.008), Further significant association was found between knowledge category and educational status (p<0.001) and between knowledge category and past experience (p< 0.001). CONCLUSION: Knowledge regarding oral hygiene was found satisfactory among the parents of preschool children visiting pediatric OPD of Dhulikhel Hospital.

Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4Si2 and CeIrAl4Si2.

We have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions T(N1) and T(N2) in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition T(N2). Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) µ(B) Ce(-1), respectively, and are parallel to the crystallographic c-axis in agreement with magnetic susceptibility measurements.

Magnetotransport of single crystalline NbAs.

We report transport measurement in zero and applied magnetic field on a single crystal of NbAs. Transverse and longitudinal magnetoresistance in the plane of this tetragonal structure does not saturate up to 9 T. In the transverse configuration (H ∥ c, I ⊥ c) it is 230,000% at 2 K. The Hall coefficient changes sign from hole-like at room temperature to electron-like below ∼150 K. The electron carrier density and mobility calculated at 2 K based on a single band approximation are 1.8 × 10(19) cm(-3) and 3.5 × 10(5) cm(2) Vs(-1), respectively. These values are similar to reported values for TaAs and NbP, and further emphasize that this class of noncentrosymmetric, transition-metal monopnictides is a promising family to explore the properties of Weyl semimetals and the consequences of their novel electronic structure.

Menopausal Health Status of Women of Kapilvastu District of Nepal.

BACKGROUND: Women face numerous health problems in their post-reproductive and menopausal years, including issues such as pelvic pain, incontinence and obstetric fistula. In Nepal, the importance of these health issues is increasing with the aging of the population, yet women are often unable to access adequate health care due to entrenched gender structures and misconceptions regarding menopause. This study aimed to describe the prevalence of menopause, the associated health problems and their severity amongst women aged 40-60 years in Kapilvastu. METHODS: A descriptive study was conducted in Kapilvastu district. Multi stage cluster sampling technique was adopted: Illakas of Kapilvastu were identified, then one Village Development Committee (VDC) from each Illaka of the district, and two wards from each of these VDCs, were selected randomly. RESULTS: The median age of onset of menopause was 47 years (25 th and 75 percentiles = 43 and 50 years), and >90% of women had entered menopause by 54. All symptoms in the Menopause Rating Scale were experienced to some extent by at least 30% of women, even amongst the premenopausal group. The most common problems experienced by menopausal women were: sexual problems (81.7%, 95%CI: 78.0-85.4), physical and mental exhaustion (81.5%, 95%CI: 77.8-85.2) and joint and muscular discomfort (78.5%, 95%CI: 74.6-82.4). The symptoms most frequently deemed "severe" or "very severe" were: sexual problems (40.5%), joint and muscular discomfort (27.4%), and sleep problems (21.0%). th CONCLUSIONS: Middle-aged women in Kapilvastu experienced menopausal symptoms to a substantial degree. The prevalence and severity of these symptoms increased with the menopausal transition, and with increasing age. Menopause itself did not appear to be the primary risk factor for typical "menopausal" symptoms.

Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds.

The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 K with an ordered moment of µsat = 0.8 µB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.

Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn5.

We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn5. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J1-J2 model that also naturally explains the magnetic spin-spiral ground state of CeRhIn5 and yields a dominant in-plane nearest-neighbor magnetic exchange constant J0=0.74(3) meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn5 (T=Co, Rh, Ir) class of heavy-fermion materials.

Probing excitonic states in suspended two-dimensional semiconductors by photocurrent spectroscopy.

The optical response of semiconducting monolayer transition-metal dichalcogenides (TMDCs) is dominated by strongly bound excitons that are stable even at room temperature. However, substrate-related effects such as screening and disorder in currently available specimens mask many anticipated physical phenomena and limit device applications of TMDCs. Here, we demonstrate that that these undesirable effects are strongly suppressed in suspended devices. Extremely robust (photogain > 1,000) and fast (response time < 1 ms) photoresponse allow us to study, for the first time, the formation, binding energies, and dissociation mechanisms of excitons in TMDCs through photocurrent spectroscopy. By analyzing the spectral positions of peaks in the photocurrent and by comparing them with first-principles calculations, we obtain binding energies, band gaps and spin-orbit splitting in monolayer TMDCs. For monolayer MoS2, in particular, we obtain an extremely large binding energy for band-edge excitons, E bind ≥ 570 meV. Along with band-edge excitons, we observe excitons associated with a van Hove singularity of rather unique nature. The analysis of the source-drain voltage dependence of photocurrent spectra reveals exciton dissociation and photoconversion mechanisms in TMDCs.

Assessment of district health system within inter-sectoral context in Nepal.

BACKGROUND: Inter-sectoral coordination has been one of the different factors in the district health system that produces efficient output which has been identified by the Alma Ata declaration as an essential component to achieve notion of 'Health for All'. This study was therefore aimed to describe the major four key functions of the health systems and to find out the situation of inter-sectoral coordination in Nepal. METHODS: A mixed method with Focus Group Discussion (FGD) and In-Depth Interview with relevant personnel to collect the majority of the data was carried out from June 2012 to November 2012 from six districts selected purposively based on the health performance indicators. RESULTS: The major findings in relation to the key functions of district health systems showed that the overall management of the district health system happens under the leadership of chief of District Health Office of Public health office with the cooperation of all the personnel in different sections in a predetermined pattern and inter-sectoral coordination and collaboration exist only to a very limited extent. CONCLUSIONS: The major constraints for inter-sectoral coordination to be effective is lack of its planning and enforcement where inter-sectoral coordination could be important for both preventive and promotive health care, waste management, water supply and sanitation, health service utilization, pesticides and human health, agriculture and nutrition, air pollution. The main components in the district health system needs an immediate attention and inter-sectoral effort should be initiated from the central level and implemented in all the levels.