Dipole matrix elements in helium in the first order shielding approximation

First order shielding approximation used to calculate off-diagonal matrix elements of dipole moment operator for heliu

Theoretical study of the absorption spectra of the sodium dimer

Absorption of radiation from the sodium dimer molecular states correlating to Na(3s)-Na(3s) is investigated theoretically. Vibrational bound and continuum transitions from the singlet X Sigma-g+ state to the first excited singlet A Sigma-u+ and singlet B Pi-u states and from the triplet a Sigma-u+ state to the first excited triplet b Sigma-g+ and triplet c Pi-g states are studied quantum-mechanically. Theoretical and experimental data are used to characterize the molecular properties taking advantage of knowledge recently obtained from ab initio calculations, spectroscopy, and ultra-cold atom collision studies. The quantum-mechanical calculations are carried out for temperatures in the range from 500 to 3000 K and are compared with previous calculations and measurements where available.Comment: 19 pages, 8 figures, revtex, eps

Challenges in diagnosing scrub typhus among hospitalized patients with undifferentiated fever at a national tertiary hospital in northern Vietnam

BACKGROUND: Scrub typhus (ST) is a leading cause of non-malarial febrile illness in Southeast Asia, but evidence of its true disease burden is limited because of difficulties of making the clinical diagnosis and lack of adequate diagnostic tests. To describe the epidemiology and clinical characteristics of ST, we conducted an observational study using multiple diagnostic assays at a national tertiary hospital in Hanoi, Vietnam. METHODOLOGY/PRINCIPAL FINDINGS: We enrolled 1,127 patients hospitalized with documented fever between June 2012 and May 2013. Overall, 33 (2.9%) patients were diagnosed with ST by PCR and/or screening of ELISA for immunoglobulin M (IgM) with confirmatory tests: 14 (42.4%) were confirmed by indirect immunoperoxidase assay (IIP), and 19 (57.6%) were by IIP and PCR. Living by farming, conjunctival injection, eschar, aspartate aminotransferase elevation, and alanine aminotransferase elevation were significantly associated with ST cases (adjusted odds ratios (aORs): 2.8, 3.07, 48.8, 3.51, and 4.13, respectively), and having a comorbidity and neutrophilia were significantly less common in ST cases (aORs: 0.29 and 0.27, respectively). The majority of the ST cases were not clinically diagnosed with rickettsiosis (72.7%). Dominant IIP reactions against a single antigen were identified in 15 ST cases, whereas indistinguishably high reactions against multiple antigens were seen in 11 ST cases. The most frequently observed dominant IIP reaction was against Karp antigen (eight cases) followed by Gilliam (four cases). The highest diagnostic accuracy of IgM ELISA in acute samples was 78%. In a phylogenetic analysis of the 56-kDa type-specific antigen gene, the majority (14 cases) were located in the Karp-related branch followed by the Gilliam-related (two cases), Kato-related (two cases), and TA763-related clades (one case). CONCLUSIONS/SIGNIFICANCE: Both the clinical and laboratory diagnoses of ST remain challenging at a tertiary hospital. Implementation of both serological and nucleic acid amplification assays covering endemic O. tsutsugamushi strains is essential

Alanine Scanning mutagenesis of the prototypic cyclotide reveals a cluster of residues essential for bioactivity

The cyclotides are stable plant-derived mini-proteins with a topologically circular peptide backbone and a knotted arrangement of three disulfide bonds that form a cyclic cystine knot structural framework. they display a wide range of pharmaceutically important bioactivities, but their natural function is in plant defense as insecticidal agents

Vibrational Excitations in Weakly Coupled Single-Molecule Junctions: A Computational Analysis

In bulk systems, molecules are routinely identified by their vibrational spectrum using Raman or infrared spectroscopy. In recent years, vibrational excitation lines have been observed in low-temperature conductance measurements on single molecule junctions and they can provide a similar means of identification. We present a method to efficiently calculate these excitation lines in weakly coupled, gateable single-molecule junctions, using a combination of ab initio density functional theory and rate equations. Our method takes transitions from excited to excited vibrational state into account by evaluating the Franck-Condon factors for an arbitrary number of vibrational quanta, and is therefore able to predict qualitatively different behaviour from calculations limited to transitions from ground state to excited vibrational state. We find that the vibrational spectrum is sensitive to the molecular contact geometry and the charge state, and that it is generally necessary to take more than one vibrational quantum into account. Quantitative comparison to previously reported measurements on pi-conjugated molecules reveals that our method is able to characterize the vibrational excitations and can be used to identify single molecules in a junction. The method is computationally feasible on commodity hardware.Comment: 9 pages, 7 figure

Corrigendum to “Counting adolescents in: the development of an adolescent health indicator framework for population-based settings”

The authors were recently made aware of an oversight such that parts of the text in the Introduction and Methods sections, which describe shortcomings in the existing literature and the methods in this work to identify frameworks and indicators, were missing attribution to published work cited elsewhere in the manuscript. To clarify, we adjust the relevant sections to fully attribute the prior work in three areas, as described below. Underlined text is additional to the original: While both school- and community-based modalities can provide nationally representative data among eligible adolescents, several shortcomings in adolescent health measurement in LMICs were noted by the GAMA Advisory Group (Reference 13 as in the original paper). First, these measurements do not equally cover all adolescent subgroups, with evidence gaps being largest for males, younger adolescents aged 10–14 years, adolescents of diverse genders, ethnicities, and religions, as well as those out of school and migrants. Second, age-disaggregated data are often lacking—due in part to incomplete age coverage—limiting their use for program planning. Third, several aspects of adolescent health are inadequately covered including mental health, substance use, injury, sexual and reproductive health among unmarried adolescents, and positive aspects of adolescent health and well-being. Fourth, the definitions and assessment methods used across adolescent health indicator frameworks are inconsistent. For example, adolescent overweight and obesity—a major cause of non-communicable diseases and a public health risk for future and intergeneration health—is inconsistently captured across indicator frameworks and strikingly absent from the SDGs (Reference 13 as in the original paper). Additional shortcomings include, current adolescent health data systems often lack intersectoral coordination beyond health (e.g., with education, water and sanitation, and social protection systems) and suffer from irregularities in coverage and timing (Reference 6 as in the original paper). Broadly, these indicator frameworks and strategy documents captured disease burden, health risks, and prominent social determinants of health during adolescence. To be congruent with the existing global recommendations and guidelines (References 3–7 as in the original paper) and global measurement efforts (References 10 and 16 as in the original paper), the indicator framework documents had to meet three inclusion criteria, as laid out by the GAMA Advisory Group (Reference 14 as in the original paper): (1) provide recommendations about the measurement of adolescents' health and well-being; (2) include indicators for “adolescents” covering the adolescent age range (10–19 years) in the whole or part; and (3) be global or regional in scope. Using the GAMA's approach (Reference 13 as in the original paper), the recommendations of Lancet Adolescent Health Commission (Reference 6 as in the original paper), and several other guidelines (References 7, 9, 12, 17–19 as in the original paper), we selected adolescent health and well-being domains based on four key aspects of adolescents in LMICs: a) population trends; b) disease burden; c) drivers of health inequality; and d) opportunity for interventions

Counting adolescents in: the development of an adolescent health indicator framework for population-based settings

Changing realities in low- and middle-income countries (LMICs) in terms of inequalities, urbanization, globalization, migration, and economic adversity shape adolescent development and health, as well as successful transitions between adolescence and young adulthood. It is estimated that 90% of adolescents live in LMICs in 2019, but inadequate data exist to inform evidence-based and concerted policies and programs tailored to address the distinctive developmental and health needs of adolescents. Population-based data surveillance such as Health and Demographic Surveillance Systems (HDSS) and school-based surveys provide access to a well-defined population and provide cost-effective opportunities to fill in data gaps about adolescent health and well-being by collecting population-representative longitudinal data. The Africa Research Implementation Science and Education (ARISE) Network, therefore, systematically developed adolescent health and well-being indicators and a questionnaire for measuring these indicators that can be used in population-based LMIC settings. We conducted a multistage collaborative and iterative process led by network members alongside consultation with health-domain and adolescent health experts globally. Seven key domains emerged from this process: socio-demographics, health awareness and behaviors; nutrition; mental health; sexual and reproductive health; substance use; and healthcare utilization. For each domain, we generated a clear definition; rationale for inclusion; sub-domain descriptions, and a set of questions for measurement. The ARISE Network will implement the questionnaire longitudinally (i.e., at two time-points one year apart) at ten sites in seven countries in sub-Saharan Africa and two countries in Asia. Integrating the questionnaire within established population-based data collection platforms such as HDSS and school settings can provide measured experiences of young people to inform policy and program planning and evaluation in LMICs and improve adolescent health and well-being

Replication of EPHA1 and CD33 associations with late-onset Alzheimer's disease: a multi-centre case-control study

<p>Abstract</p> <p>Background</p> <p>A recently published genome-wide association study (GWAS) of late-onset Alzheimer's disease (LOAD) revealed genome-wide significant association of variants in or near <it>MS4A4A, CD2AP, EPHA1 </it>and <it>CD33</it>. Meta-analyses of this and a previously published GWAS revealed significant association at <it>ABCA7 </it>and <it>MS4A</it>, independent evidence for association of <it>CD2AP, CD33 </it>and <it>EPHA1 </it>and an opposing yet significant association of a variant near <it>ARID5B</it>. In this study, we genotyped five variants (in or near <it>CD2AP, EPHA1, ARID5B</it>, and <it>CD33</it>) in a large (2,634 LOAD, 4,201 controls), independent dataset comprising six case-control series from the USA and Europe. We performed meta-analyses of the association of these variants with LOAD and tested for association using logistic regression adjusted by age-at-diagnosis, gender, and <it>APOE ε4 </it>dosage.</p> <p>Results</p> <p>We found no significant evidence of series heterogeneity. Associations with LOAD were successfully replicated for <it>EPHA1 </it>(rs11767557; OR = 0.87, p = 5 × 10^-4) and <it>CD33 </it>(rs3865444; OR = 0.92, p = 0.049), with odds ratios comparable to those previously reported. Although the two <it>ARID5B </it>variants (rs2588969 and rs494288) showed significant association with LOAD in meta-analysis of our dataset (p = 0.046 and 0.008, respectively), the associations did not survive adjustment for covariates (p = 0.30 and 0.11, respectively). We had insufficient evidence in our data to support the association of the <it>CD2AP </it>variant (rs9349407, p = 0.56).</p> <p>Conclusions</p> <p>Our data overwhelmingly support the association of <it>EPHA1 </it>and <it>CD33 </it>variants with LOAD risk: addition of our data to the results previously reported (total n > 42,000) increased the strength of evidence for these variants, providing impressive p-values of 2.1 × 10^-15(<it>EPHA1</it>) and 1.8 × 10^-13(<it>CD33</it>).</p

Antiferromagnetic spintronics

Antiferromagnetic materials are magnetic inside, however, the direction of their ordered microscopic moments alternates between individual atomic sites. The resulting zero net magnetic moment makes magnetism in antiferromagnets invisible on the outside. It also implies that if information was stored in antiferromagnetic moments it would be insensitive to disturbing external magnetic fields, and the antiferromagnetic element would not affect magnetically its neighbors no matter how densely the elements were arranged in a device. The intrinsic high frequencies of antiferromagnetic dynamics represent another property that makes antiferromagnets distinct from ferromagnets. The outstanding question is how to efficiently manipulate and detect the magnetic state of an antiferromagnet. In this article we give an overview of recent works addressing this question. We also review studies looking at merits of antiferromagnetic spintronics from a more general perspective of spin-ransport, magnetization dynamics, and materials research, and give a brief outlook of future research and applications of antiferromagnetic spintronics.Comment: 13 pages, 7 figure

Stabilization of weak ferromagnetism by strong magnetic response to epitaxial strain in multiferroic BiFeO3

Multiferroic BiFeO3 exhibits excellent magnetoelectric coupling critical for magnetic information processing with minimal power consumption. However, the degenerate nature of the easy spin axis in the (111) plane presents roadblocks for real world applications. Here, we explore the stabilization and switchability of the weak ferromagnetic moments under applied epitaxial strain using a combination of first-principles calculations and group-theoretic analyses. We demonstrate that the antiferromagnetic moment vector can be stabilized along unique crystallographic directions ([110] and [-110]) under compressive and tensile strains. A direct coupling between the anisotropic antiferrodistortive rotations and the Dzyaloshinskii-Moria interactions drives the stabilization of the weak ferromagnetism. Furthermore, energetically competing C- and G-type magnetic orderings are observed at high compressive strains, suggesting that it may be possible to switch the weak ferromagnetism &quot;on&quot; and &quot;off&quot; under the application of strain. These findings emphasize the importance of strain and antiferrodistortive rotations as routes to enhancing induced weak ferromagnetism in multiferroic oxides.ope