Suppression of spin-state transition in epitaxially strained LaCoO_{3}

Epitaxial thin films of LaCoO_{3} (E-LCO) exhibit ferromagnetic order with a transition temperature T_c = 85 K, while polycrystalline thin LaCoO_{3} films (P-LCO) remain paramagnetic. The temperature-dependent spin-state structure for both E-LCO and P-LCO was studied by x-ray absorption spectroscopy at the Co L_{2,3} and O K edges. Considerable spectral redistributions over temperature are observed for P-LCO. The spectra for E-LCO, on the other hand, do not show any significant changes for temperatures between 30 K and 450 K at both edges, indicating that the spin state remains constant and that the epitaxial strain inhibits any population of the low-spin (S = 0) state with decreasing temperature. This observation identifies an important prerequisite for ferromagnetism in E-LCO thin films.Comment: 5 pages, 5 figures, submitted to Physical Review

Risk Factors for Stunting in Children under the Age of 5 in Rural Guatemalan Highlands

Background: Previously, a study conducted by UNICEF found that malnutrition affects approximately 80% of the indigenous children in Guatemala. Objective: Identify prevalence and risk factors for stunted growth in communities surrounding Lake Atitlán, Guatemala. Methods: Height-for-age measurements of children under the age of five, N = 84, determined stunting prevalence and presumed burden of malnutrition in this region of the Guatemalan highlands. Mothers of a subset of this sample, N = 29, were interviewed to assess factors contributing to stunting. Analysis assessed the following risk factors: inadequate nutrition, increased infectious disease risk, high rate self-report illness, inadequate breastfeeding, and inadequate utilization of prenatal care. Findings: The majority of children under the age of five were stunted (65.6%) and likely malnourished. ANOVA analysis showed significant differences in mean height-for-age Z scores (HAZs) between groups with and without adequate nutrition (F = 7.069, p = 0.013), as well has with and without high rates of self-report illness (F = 6.894, p = 0.014). Both groups with inadequate nutrition (mean HAZs = –2.9, 95% CI = [–3.58, –2.24]) and high rates of self-report illness (mean HAZs = –2.8, 95% CI = [–3.13, –2.38]) had mean HAZs that are indicative of stunting. No other risk factors were associated with stunting. Conclusion: These pilot study results offer methods by which to obtain baseline data for assessing nutritional and public health interventions to improve stunting and malnutrition status as well as the health outcomes of children in rural, indigenous communities

Electronic Medical Record-Assisted Telephone Follow-Up of Breast Cancer Survivors During the COVID-19 Pandemic: A Single Institution Experience

PURPOSE: The COVID-19 outbreak rapidly became a public health emergency and led to radical changes in patient management. From the start of the pandemic, we used electronic medical record-assisted telephone follow-up (E-TFU) of cancer survivors (CS) to minimize hospital exposure. The aim of this prospective study was to assess how breast cancer survivors (bCSs) perceived E-TFU. MATERIALS AND METHODS: A 15-item survey was e-mailed to bCSs who had been managed with E-TFU. The responses were measured using Likert-like scales and were correlated with the main characteristics of the bCS using Pearson's test. RESULTS: One hundred thirty-seven of 343 bCSs (40%) completed the survey between March 9 and June 2, 2020. Their median age was 59 years. Although 80.3% of bCSs were satisfied with E-TFU, only 43.8% would like to have E-TFU in the future. A low educational level was correlated with higher COVID-19-related anxiety (P = .025). An older age (P = .002) and a low educational level (P < .0001) were correlated with the need to be accompanied to reach the hospital. A personal history of second cancer was inversely correlated with understanding medical advice (P = .015) and the expectation of feeling relief after a follow-up visit (P = .0027). Furthermore, pandemic phase II was correlated with satisfaction with E-TFU (P = .010). CONCLUSION: E-TFU was an important means of avoiding hospital contacts during the COVID-19 pandemic, and the majority of bCSs in the survey were satisfied with this procedure. Further studies are needed to investigate the implementation of telemedicine even outside an emergency situation

First-principles investigation of 180-degree domain walls in BaTiO_3

We present a first-principles study of 180-degree ferroelectric domain walls in tetragonal barium titanate. The theory is based on an effective Hamiltonian that has previously been determined from first-principles ultrasoft-pseudopotential calculations. Statistical properties are investigated using Monte Carlo simulations. We compute the domain-wall energy, free energy, and thickness, analyze the behavior of the ferroelectric order parameter in the interior of the domain wall, and study its spatial fluctuations. An abrupt reversal of the polarization is found, unlike the gradual rotation typical of the ferromagnetic case.Comment: Revtex (preprint style, 13 pages) + 3 postscript figures. A version in two-column article style with embedded figures is available at http://electron.rutgers.edu/~dhv/preprints/index.html#pad_wal