Nonlinear Optics: The Enabling Technology for Quantum Information Science

Nonlinear optical processes such as parametric down conversion and squeezed light generation are key elements of most quantum protocols, leading to crucial applications such as quantum imaging, sub-shot-noise metrology, and secure communication

RNA reference materials with defined viral RNA loads of SARS-CoV-2—A useful tool towards a better PCR assay harmonization

SARS-CoV-2, the cause of COVID-19, requires reliable diagnostic methods to track the circulation of this virus. Following the development of RT-qPCR methods to meet this diagnostic need in January 2020, it became clear from interlaboratory studies that the reported Ct values obtained for the different laboratories showed high variability. Despite this the Ct values were explored as a quantitative cut off to aid clinical decisions based on viral load. Consequently, there was a need to introduce standards to support estimation of SARS-CoV-2 viral load in diagnostic specimens. In a collaborative study, INSTAND established two reference materials (RMs) containing heat-inactivated SARS-CoV-2 with SARS-CoV-2 RNA loads of ~107 copies/mL (RM 1) and ~106 copies/mL (RM 2), respectively. Quantification was performed by RT-qPCR using synthetic SARS-CoV-2 RNA standards and digital PCR. Between November 2020 and February 2021, German laboratories were invited to use the two RMs to anchor their Ct values measured in routine diagnostic specimens, with the Ct values of the two RMs. A total of 305 laboratories in Germany were supplied with RM 1 and RM 2. The laboratories were requested to report their measured Ct values together with details on the PCR method they used to INSTAND. This resultant 1,109 data sets were differentiated by test system and targeted gene region. Our findings demonstrate that an indispensable prerequisite for linking Ct values to SARS-CoV-2 viral loads is that they are treated as being unique to an individual laboratory. For this reason, clinical guidance based on viral loads should not cite Ct values. The RMs described were a suitable tool to determine the specific laboratory Ct for a given viral load. Furthermore, as Ct values can also vary between runs when using the same instrument, such RMs could be used as run controls to ensure reproducibility of the quantitative measurements.Peer Reviewe

Maternal Colonization With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses.

Background: Maternal rectovaginal colonization with group B Streptococcus (GBS) is the most common pathway for GBS disease in mother, fetus, and newborn. This article, the second in a series estimating the burden of GBS, aims to determine the prevalence and serotype distribution of GBS colonizing pregnant women worldwide. Methods: We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus), organized Chinese language searches, and sought unpublished data from investigator groups. We applied broad inclusion criteria to maximize data inputs, particularly from low- and middle-income contexts, and then applied new meta-analyses to adjust for studies with less-sensitive sampling and laboratory techniques. We undertook meta-analyses to derive pooled estimates of maternal GBS colonization prevalence at national and regional levels. Results: The dataset regarding colonization included 390 articles, 85 countries, and a total of 299924 pregnant women. Our adjusted estimate for maternal GBS colonization worldwide was 18% (95% confidence interval [CI], 17%-19%), with regional variation (11%-35%), and lower prevalence in Southern Asia (12.5% [95% CI, 10%-15%]) and Eastern Asia (11% [95% CI, 10%-12%]). Bacterial serotypes I-V account for 98% of identified colonizing GBS isolates worldwide. Serotype III, associated with invasive disease, accounts for 25% (95% CI, 23%-28%), but is less frequent in some South American and Asian countries. Serotypes VI-IX are more common in Asia. Conclusions: GBS colonizes pregnant women worldwide, but prevalence and serotype distribution vary, even after adjusting for laboratory methods. Lower GBS maternal colonization prevalence, with less serotype III, may help to explain lower GBS disease incidence in regions such as Asia. High prevalence worldwide, and more serotype data, are relevant to prevention efforts

The Digital MIQE Guidelines Update: Minimum Information for Publication of Quantitative Digital PCR Experiments for 2020

Digital PCR (dPCR) has developed considerably since the publication of the Minimum Information for Publication of Digital PCR Experiments (dMIQE) guidelines in 2013, with advances in instrumentation, software, applications, and our understanding of its technological potential. Yet these developments also have associated challenges; data analysis steps, including threshold setting, can be difficult and preanalytical steps required to purify, concentrate, and modify nucleic acids can lead to measurement error. To assist independent corroboration of conclusions, comprehensive disclosure of all relevant experimental details is required. To support the community and reflect the growing use of dPCR, we present an update to dMIQE, dMIQE2020, including a simplified dMIQE table format to assist researchers in providing key experimental information and understanding of the associated experimental process. Adoption of dMIQE2020 by the scientific community will assist in standardizing experimental protocols, maximize efficient utilization of resources, and further enhance the impact of this powerful technology

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

The impact of exposure to luxury brands on social media on self-esteem, conformity, and the counterfeit market

Billions of people worldwide use a variety of social media platforms, with Facebook alone amassing “1.56 billion daily active users as of March 31, 2019” (Appel et al., 2019). The majority of luxury consumers are daily active users of social media for personal use or to research products and trends. The counterfeit market cannot survive without the foundations built by luxury brands. There is an abundance of literature available on both of these industries discussing them in relation to the research objectives to some extent. This research paper investigates the impact of exposure to luxury brands on social media and its effect on self-esteem, conformity, and the counterfeit goods market. This investigation is carried out using primary and secondary data. Secondary data in the form of a literature review is used to examine the evidence relating to the chosen research objectives and hypotheses. A quantitative questionnaire is used as the methodology tool to gather primary data to further expand on the secondary data findings, with a total of 186 respondents. The findings of this study reveals that exposure to luxury brands on social media have little impact on self-esteem, conformity, and the counterfeit market of the research sample. It is evident that more research should be undertaken to revaluate and re-examine the results using the recommendations for future research

Integrated ‘one-stop’ support for student success: recommendations from a regional university case study

Cohesive integration practices within ‘one-stop’ student support services are critical for student success, however empirical studies in this area are limited in number and scope. This case study addresses this gap by exploring the lived experience of staff and managers who support students at a regional Australian university’s integrated student service. This integrated service provides students with support through the following services: the library, ICT help, student support and retention, learning support and student services. Semi-structured interviews with integrated service managers and staff, alongside observations of front-facing staff and students, provided the data set for this research. Thematic analysis was used to code 18 interview transcripts and seven observation journal entries to analyse and develop themes of experience. The five identified themes form a hierarchal relationship across individual and interpersonal levels of participant experience. On the individual level, are the themes of understanding, skills and student-centred philosophy. Building upon these individual-level themes are the two interpersonal level themes of communication and collaboration. Recommendations derived from these findings encompass practical strategies for universities looking to enhance their integrated service point operations. These strategies include comprehensive professional development, enhancing communication and supporting collaborations. Overall, this case study highlights the critical interpersonal and individual factors that affect this integrated service’s ability to support student success

Activation of C−H, N−H, and O−H Bonds via Proton-Coupled Electron Transfer to a Mn(III) Complex of Redox-Noninnocent Octaazacyclotetradecadiene, a Catenated-Nitrogen Macrocyclic Ligand

The article of record as published may be found at https://doi.org/10.1021/jacs.8b10250Reaction of 1,3-diazidopropane with an electron-rich Mn(II) precursor results in oxidation of the metal center to a Mn complex with concomitant assembly of the macrocyclic ligand into the 1,2,3,4,8,9,10,11-octaazacyclotetradeca-2,9-diene-1,4,8,11-tetraido (OIM) ligand. Although describable as a Werner Mn(V) complex, analysis by X-ray diffraction, magnetic measurements, X-ray photoelectron spectroscopy, cyclic voltammetry, and density functional theory calculations suggest an electronic structure consisting of a Mn(III) metal center with a noninnocent OIM diradical ligand. The resulting complex, (OIM)Mn(NHtBu), reacts via proton-coupled electron transfer (PCET) with phenols to form phenoxyl radicals, with dihydroanthracene to form anthracene, and with (2,4-ditert-butyltetrazolium-5-yl)amide to extrude a tetrazyl radical. PCET from the latter generates the isolable corresponding one-electron reduced compound with a neutral, zwitterionic axial 2,4-ditert-butyltetrazolium-5-yl)amido ligand. Electron paramagnetic resonance and density functional theoretical analyses suggest an electronic structure wherein the manganese atom remains Mn(III) and the OIM ligand has been reduced by one electron to a monoradical noninnocent ligand. The result indicates PCET processes whereby the proton is transferred to the axial ligand to extrude tBuNH2, the electron is transferred to the equatorial ligand, and the central metal remains relatively unperturbed.Office of Naval Research under award number N00014-16-1-2055 and by the National Science Foundation under award 1362016. DFT calculations were supported by the Office of Naval Research Multi-University Research Initiative Grant No. N0001417WX00357. The CENTC elemental analysis center at Rochester University is supported by NSF under award number 0650456. NMR instrumentation at Temple University is supported by a CURE grant from the Pennsylvania Department of Health. The XPS measurements carried out at the University of Delaware surface analysis facility were supported by the NSF under grant 1428149 and by the NIH NIGMS COBRE program under grant P30-GM110758.Office of Naval Research under award number N00014-16-1-2055 and by the National Science Foundation under award 1362016. DFT calculations were supported by the Office of Naval Research Multi-University Research Initiative Grant No. N0001417WX00357. The CENTC elemental analysis center at Rochester University is supported by NSF under award number 0650456. NMR instrumentation at Temple University is supported by a CURE grant from the Pennsylvania Department of Health. The XPS measurements carried out at the University of Delaware surface analysis facility were supported by the NSF under grant 1428149 and by the NIH NIGMS COBRE program under grant P30-GM110758

Sentiment score of relevant posts identified from social media by date.

<p>Relevant posts mentioned impact of unplanned school closure due to Chicago teachers’ strike from September 8–21 (two days before to three days after strike) on students and their families (N = 930). Sentiment score was calculated as: (positive posts—negative posts)/(positive posts + negative posts + neutral posts)^a-b. ^aSentiment score < 0 suggests negative sentiment; score > 0 suggests positive sentiment. ^bScore on September 21 reflects only four relevant posts, all expressing negative sentiment.</p

Number of relevant posts identified from social media by sentiment^a and date.

<p>Relevant posts mentioned impact of unplanned school closure due to Chicago teachers’ strike from September 8–21, 2012 (two days before and three days after strike) on students and their families (n = 930). ^aSentiment definitions: Positive: The author expressed a good or favorable experience as a result of the closure. Example of positive post: “Another day without school, a day to play.” Negative: The author expressed inconveniences or undesirable effect as a result of the closure. Example of negative post: “I can’t find childcare”. Neutral: The author did not express any particular sentiment. Example of neutral post: “Schools will be open at 8:00 to serve breakfast to students”.</p