bluuebunny/crossref_metadata_2025 huggingface dataset:
Considerations in Safe to Sleep® messaging: Learning from African–American mothers
Authors: Stiffler Deborah , Matemachani Sherry Mukasa , Crane Lisa
Published: November 2019

Purpose

The purpose of this study was to identify why African–American mothers do not tend to follow the Safe to Sleep® recommendations and to begin to identify a way to frame the Safe to Sleep® message so that African–American mothers might be more likely to follow these recommendations.

Design

We recruited African–American mothers with infants over the age of 6 months to participate in two focus groups facilitated by a community engagement manager experienced in focus group facilitation. We used ethnography to find shared patterns of behavior and beliefs in African–American women related to safe sleep.

Results

We identified 14 concepts and formulated them into three categories: it's just easier; can't fight culture and grandma; and Effectively teaching mother. From these we were able to identify the shared value of multifaceted learning.

Practice implications

African–American mothers say that they are generally aware of the Safe to Sleep® recommendations, even though the majority of mothers do not follow them. The reasons they give for not following them are that they are not comfortable doing so, they feel they are unable to do so, or find it unnecessary. Many of the mothers attempted to follow the Safe to Sleep® recommendations but abandoned the effort due to the stress of their crying infant. Trying to follow the Safe to Sleep® recommendations were stressful for the mothers, even though there was concern expressed by some that their infant could indeed suffocate or die from sudden infant death syndrome. The mothers gave suggestions on how they would change the message or the delivery of the message.
Numerical expressions of otolith shape and morphometric relationships for five fish species in tidal‐linked lagoons in the northern Arabian Sea
Authors: Qamar Nazia , Panhwar Sher Khan , Awan Khawar Parvez , Farooq Noureen
Published: November 2019

Otoliths from five fish species, including Acanthopagrus latus, Daysciaena albida, Ellochelon vaigiensis, Mugil cephalus and Mystus gulio, were used to develop numerical expressions involving otolith shape indices and morphometric parameters. A total of 342 fish specimens in lagoons (24°39′ 0N, 68°50′0E) were sampled from August 2014 to July 2015. A linear model related to fish sizes, otolith sizes and weights were applied, with estimated coefficients of determinations (r2 = 0.99–0.53). Otolith shape indices, including form factor, roundness, aspect ratio, circularity, rectangularity and ellipticity for each fish species, also were analysed. The results of the present study are the first to describe relationships between otolith dimensions, fish morphometrics and shape indices of highly valued fish species and can be an important input for further trophic modelling to study food web dynamics.
Toxic shock‐like syndrome following third molar extraction: case report
Authors: Aquino V.M. , Hildebrand J.M. , Hester J.
Published: November 2019

Streptococcal toxic shock‐like syndrome (TSLS) is a rare and fatal infection associated with Streptococcus pyogens (group A streptococcus). While there are documented cases of TSLS, it is rarely observed following extraction on non‐infected wisdom teeth. We describe the diagnostic criteria and successful treatment of a case of TSLS resulting in multisystem organ failure following uncomplicated extraction of his wisdom teeth in a healthy 18‐year‐old male.
The performance of a postinduction fentanyl test in identifying severe obstructive sleep apnea syndrome
Authors: Wu Ru , Wang Xuan , Zhuang Peijun , Zhou Zhijian , Li Yihang , Zhang Fan
Published: November 2019

Background

Children with severe obstructive sleep apnea syndrome (OSAS) are more sensitive to opioids. Identifying such children and reducing or even eliminating opioids are necessary but difficult. We have previously shown that patients sensitive to intraoperative fentanyl require less opioids postoperatively.

Aim

The objective of this study was to evaluate the performance of a postinduction fentanyl test in identifying severe obstructive sleep apnea syndrome.

Methods

A prospective, observational, assessor‐blinded study was carried out with 104 sleep study assessed children undergoing elective adenotonsillectomy. Intravenous fentanyl (1 µg/kg) was administered as a test in nonpremedicated, spontaneously breathing, sevoflurane‐induced patients before endotracheal intubation. The respiratory rates before and after fentanyl administration were studied. The primary outcome was the sensitivity and specificity of the postinduction fentanyl test in identifying severe OSAS compared with polysomnography.

Results

A postinduction fentanyl test had a likelihood ratio of 7.2 (95% CI: 3.6‐14.6) and an area under the curve value of 0.896 (95% CI: 0.821‐0.947) to identify severe obstructive sleep apnea syndrome. The pragmatic cut‐off value for the postinduction fentanyl test was found to be 50%. Using a reduction in respiratory rate of >50%, the postinduction fentanyl test detected severe OSAS with a sensitivity of 87%, a specificity of 88%, a positive predictive value of 85%, and a negative predictive value of 89%.

Conclusion

Our study showed that a postinduction fentanyl test had good predictive value in identifying severe obstructive sleep apnea syndrome and early postoperative adverse respiratory events and could provide a reference for postoperative analgesia in children undergoing adenotonsillectomy.
The relationship between ingroup identity and Paranoid ideation among people from African and African Caribbean backgrounds
Authors: McIntyre Jason C. , Elahi Anam , Barlow Fiona Kate , White Ross G. , Bentall Richard P.
Published: November 2019

Objectives

People from ethnic minority groups experience higher rates of paranoid delusions compared with people from ethnic majority groups. Identifying with social groups has been shown to protect against mental health symptoms; however, no studies have investigated the relationship between social identification and paranoia in ethnic minority populations. Here, we investigated the association between British identification and paranoia in a sample of people from African and African Caribbean backgrounds living in the United Kingdom. We also assessed the role of potential mediating (self‐esteem and locus of control) and moderating (contact with White British people) factors.

Design

Cross‐sectional quantitative survey design.

Methods

We recruited 335 people from African and African Caribbean backgrounds who completed online self‐report measures of identification with Great Britain, self‐esteem, locus of control, positive and negative contact with White British people, and paranoia.

Results

A parallel moderated mediation model indicated that British identification was associated with lower paranoia when participants experienced primarily positive contact with White British people. British identification was associated with higher paranoia when participants had primarily negative contact with White British people. Both effects were mediated by changes in locus of control, but self‐esteem was not implicated in either pathway.

Conclusions

Identification with the majority culture is associated both positively and negatively with paranoid beliefs depending on the types of social interactions people experience. The findings have implications for preventative social prescribing initiatives and for understanding the causes of the high rates of psychosis in ethnic minority populations.

Practitioner points

People from African and African Caribbean backgrounds experience high rates of paranoia, which may stem from social causes such as lack of belonging and negative social experiences.

Among people from African backgrounds living in the UK, British identification is associated with lower paranoia when people’s social experiences with White British people are positive and higher paranoia when their social experiences with White British people are negative.

It is recommended that social interventions designed to reduce paranoia in vulnerable groups foster positive social contact and community belonging, which should enhance feelings of personal control.

Understanding the complex interplay between social identity and social contact in the development of paranoia may help therapists and researchers better understand the phenomenology and risk factors of paranoid symptomology.
An Additional Form of Appropriation: A Note
Authors: McCann Anthony
Published: November 2019

Forms of appropriations continually evolve as Congress attempts to balance the interest of the appropriations committees against those committees and program supporters interested in assuring funding for their priorities. The 21st Century Cures Act is the latest attempt to balance these forces. The Act contains a two‐step process (i) the creation of an account via mandatory appropriations and (ii) the added requirement that funds be appropriated from the account via the annual appropriations process in order to be available for programmatic activity.
Revisiting predictive bias of cognitive ability tests against Hispanic American job applicants
Authors: Berry Christopher M. , Zhao Peng , Batarse Juan Carlos , Reddock Craig
Published: November 2019

Previous studies have concluded that cognitive ability tests are not predictively biased against Hispanic American job applicants because test scores generally overpredict, rather than underpredict, their job performance. However, we highlight two important shortcomings of these past studies and use meta‐analytic and computation modeling techniques to address these two shortcomings. In Study 1, an updated meta‐analysis of the Hispanic–White mean difference (d‐value) on job performance was carried out. In Study 2, computation modeling was used to correct the Study 1 d‐values for indirect range restriction and combine them with other meta‐analytic parameters relevant to predictive bias to determine how often cognitive ability test scores underpredict Hispanic applicants’ job performance. Hispanic applicants’ job performance was underpredicted by a small to moderate amount in most conditions of the computation model. In contrast to previous studies, this suggests cognitive ability tests can be expected to exhibit predictive bias against Hispanic applicants much of the time. However, some conditions did not exhibit underprediction, highlighting that predictive bias depends on various selection system parameters, such as the criterion‐related validity of cognitive ability tests and other predictors used in selection. Regardless, our results challenge “lack of predictive bias” as a rationale for supporting test use.
Distribution of the HLA‐DPB1 alleles in a Russian population living in the Chelyabinsk region (South Ural of Russia)
Authors: Burmistrova Alexandra L. , Vavilov Mikhail N. , Khromova Elena B. , Suslova Tatiana A.
Published: November 2019

The purpose of this work was to establish the distribution of HLA‐DPB1 alleles in Russians living in the Chelyabinsk region (Russia). DPB1 frequencies were determined in 100 unrelated Russian, living in the Chelyabinsk region. All subjects were healthy unrelated blood donors, between 18 and 55 years of age. Typing was performed by NGS (DNA‐technology, Moscow). For population genetics analysis GENE[RATE] (https://hla-net.eu/tools/) software was used. DPB1*04:01 prevails in this population (gf = 0.3667). Other frequent HLA‐DPB1 alleles were: DPB1*04:02, DPB1*02:01, DPB1*03:01 (gf = 0.1490; 0.1481; 0.1385, respectively). Rare alleles (gf ≤ 0.03) were DPB1*17:01, DPB1*01:01, DPB1*06:01, DPB1*14:01, DPB1*05:01, DPB1*13:01, DPB1*09:01, DPB1*10:01, DPB1*11:01, DPB1*23:01, DPB1*124:01, DPB1*15:01, DPB1*16:01, DPB1*105:01, DPB1*150:01.
Coups d'état and the foreign exchange market
Authors: Balima Hippolyte Weneyam
Published: November 2019

I empirically examine the effect of coups d'état on the foreign exchange market using a monthly panel dataset covering 150 countries over the period 1980–2015. Specifically, I investigate whether foreign exchange market's participants sanction a country following a coup d'état event by allowing depreciations of its national currency against a weighted basket of currencies of its trading partners. I combine different identification strategies and find that the occurrence of a coup d'état induces a depreciation of the nominal effective exchange rate in the coup d'état country and generates negative spillover effects on neighbouring countries. Once a coup occurs, a country level of financial buffers and the flexibility of its exchange rate regime allow reducing the magnitude of the depreciation. In addition, I provide evidence that coups also increase the likelihood of experiencing a currency crisis by about 2 percentage points in coup d'état countries compared to non‐coup d'état countries.
Postural preinspiratory cortical activity, genioglossus activity and fluid shift in awake obstructive sleep apnoea patients
Authors: Launois Claire , Nierat Marie‐Cécile , Attali Valérie , Raux Mathieu , Arnulf Isabelle , Similowski Thomas , Redolfi Stefania
Published: November 2019

New Finding

What is the central question of this study?

Transition to supine posture induces an inspiratory load associated with cortical activation in awake healthy subjects. Some obstructive sleep apnoea patients exhibit this cortical activity in the sitting position contributing to the arousal‐dependent compensation of their upper airway abnormalities. Does a transition to the supine posture in awake obstructive sleep apnoea patients increase this cortical activity?

What is the main finding and its importance?

The transition to supine posture induces a reduction in the cortical activity despite evidence of an increase in genioglossus activity, suggesting that genioglossus activation is not driven by cortical activity.

The anatomy and mechanical properties of the upper airway (UA) depend on posture. Lying in a supine position causes cephalad fluid shift to the neck, thus narrowing the UA and predisposing the individual to obstructive sleep apnoea (OSA). Increased UA dilator muscle activity during wakefulness prevents the UA collapse but the underlying mechanism has not yet been elucidated. In the sitting position during wakefulness, some OSA patients exhibit preinspiratory cortical activity (preinspiratory potential, PIP) probably related to UA abnormalities. The aim of this study was to investigate changes in the preinspiratory cortical activity and UA dilator muscle in OSA patients during postural challenge. An electroencephalogram was used to detect PIP, and the genioglossus electromyographic activity and ventilation were analysed in 17 awake, male OSA patients while they were sitting, just after lying down, and then in response to leg positive pressure to enhance cephalad fluid shift. The prevalence of PIP decreased from 53% (sitting) to 12% (supine) (P = 0.002) in association with increased genioglossus activity (tonic from median (25th, 75th centiles) 2.3 (1.8, 2.8)% to 3.6 (1.7, 5.0)% of voluntary deglutition, P = 0.019; phasic from 2.3 (1.9, 2.8)% to 3.7 (2.0, 6.1)%, P = 0.024), and with increased transcutaneous carbon dioxide pressure (from 43.0 (42.4, 44.2) to 44.6 (43.5, 45.2) mmHg). No change was observed during leg‐positive‐pressure application. Moving from the sitting position to the supine position reduces respiratory‐related premotor cortical activity in awake OSA patients. The concomitant increase in genioglossus activity, therefore, is not driven by cortical respiratory activity.
Application of a Reduced Mechanism by Computational Singular Perturbation Method to the Calculation of the Ignition Delays of a Turbulence Diffusion Flame CH4/H2/N2
Authors: Gnentedem Cyrille , Awakem David , Obounou Marcel , Ekobena Fouda Henri Paul , Njomo Donatien
Published: November 2019

This work presents an application of a reduced chemical kinetic mechanism using computational singular perturbation (CSP) based on the significant indices of the modes on the evolution of species and the degree of participation of reactions. With this approach, the mechanism of Yang and Pope is reduced to 22 reversible reactions (RR22). In this study, the tabulation of ignition delays is made with Yang and Pope mechanism, GRI 3.0, and the reduced mechanism RR22; the results obtained show a good agreement among the three mechanisms. The “Modèle Intermittent Lagrangien” (MIL) necessary to calculate the chemical source term of the transport equation of the species requires the library of ignition delays determined above and a probability density function (PDF) of the mixture fraction presumed by a beta distribution. The scalar variance, one of the key parameters for the determination of the presumed beta function, is obtained by solving its own transport equation with the unclosed scalar dissipation rate modeled using either an algebraic model or a transport equation. All these models are introduced in the computational fluid dynamics “Code-Saturne” to simulate a turbulent CH4/H2/N2 jet flame (DLR Flame A) performed at the Deutsches Zentrum für Luft-und Raumfahrt (DLR), or German Aerospace Center. A set of comparisons is made and the results of simulations show a good agreement among the three mechanisms as well with the experimental data.
Spectroscopic reflectometry for characterization of Through Silicon Via profile of Bosch etching process
Authors: Bauer Joachim , Fursenko Oksana , Marschmeyer Steffen , Heinrich Friedhelm , Villasmunta Francesco , Villringer Claus , Zesch Christoph , Schrader Sigurd
Published: November 2019

Through Silicon Via (TSV) technology is a key in 3D integration of circuits by the creation of interconnects using vias, which go through the full silicon wafer. Typically, a highly-selective Bosch Si etch process is used. It is characterized by a high etch rate at a high aspect ratio, whereby scallops on the sidewalls are generated. In this work, square via arrays with dimensions from 3 to 50 μm and up to 300 μm depth were fabricated and analyzed by spectroscopic reflectometry. The reflectometric data are compared to simulations by a novel theoretical approach. In order to simulate the reflectance spectra of TSV arrays, a combination of 2D and 3D rigorous coupled wave analysis was applied. Besides the via depth, the sidewall angle and the corner radius of the bottom profile were considered in the model. The general requirements on spectral resolution in TSV metrology are discussed.
Energy-resolved coincidence counting using an FPGA for nuclear lifetime experiments
Authors: Vretenar Mario , Erceg Nataša , Karuza Marin
Published: November 2019

With the increasing availability of single-board computers equipped with fast analog-to-digital converters based on field-programmable gate arrays (FPGA), researchers and educators gain access to relatively inexpensive hardware that can be programmed for advanced coincidence counting. We demonstrate this capability by developing software for a dual-channel open-source data acquisition platform, enabling it to perform energy- and time-resolved coincidence counting and testing our system using an 241Am source. Measuring the coincidence between alpha and gamma radiation allowed us to determine the half-life of the 237Np excited state. The obtained value of 67.7 ± 0.1 ns is compatible with the value cited in the literature. Furthermore, the use of digital signal processing enabled us to sort time-resolved counts by alpha and gamma energy, which resulted in additional information on the decay scheme. Correlation heatmaps between the two spectra were plotted and used to verify the decay scheme. The half-lives of the other features visible in the gamma spectrum were determined as well.
Equilibrium and stability of thin spherical shells in Newtonian and relativistic gravity
Authors: LeMaitre Philip , Poisson Eric
Published: November 2019

We consider thin spherical shells of matter in both Newtonian gravity and general relativity and examine their equilibrium configurations and dynamical stability. Thin-shell models are admittedly a poor substitute for realistic stellar models. But the simplicity of the equations that govern their dynamics, compared to the much more complicated mechanics of a self-gravitating fluid, allows us to deliver, in a very direct and easy manner, powerful insights into their equilibria and stability. We explore, in particular, the link between the existence of a maximum mass along a sequence of equilibrium configurations and the onset of dynamical instability. Such a link is well-established in the case of fluid bodies in both Newtonian gravity and general relativity, but the demonstration of this link is both subtle and difficult. The proof is very simple, however, in the case of thin shells, and it is constructed with nothing more than straightforward algebra and a little calculus.
A sundial with hour lines portraying the Earth
Authors: Heierli Joachim
Published: November 2019

The study of sundials is an age-old discipline of science. The greatest developments were achieved in the Antiquity and in the Middle Ages, but modern physicists also contributed their part. In 1956, a former student of Wolfgang Pauli, Heinz Schilt, constructed an underwater sundial in his garden pond, using refraction to reshape the sundial's hour lines. His approach is developed further in this paper and combined with Thales' geometric concept of gnomonic projection. Together, this leads to a beautiful result: Snell's law can be used to build a sundial whose hour lines portray the Earth and its meridians. A prototype has been built to demonstrate the idea.
Activity of Different Antistaphylococcal Therapies, Alone or Combined, in a Rat Model of Methicillin-Resistant Staphylococcus epidermidis Osteitis without Implant
Authors: Albac S. , Labrousse D. , Hayez D. , Anzala N. , Bonnot D. , Chavanet P. , Aslangul E. , Croisier D.
Published: November 2019

We developed a rat model of methicillin-resistant
Staphylococcus epidermidis
(MRSE) osteitis without implant to compare the efficacy of vancomycin, linezolid, daptomycin, ceftaroline, and rifampin either alone or in association with rifampin. A clinical strain of MRSE was inoculated into the proximal tibia. Following a 1-week infection period, rats received either no treatment or 3, 7, or 14 days of human-equivalent antibiotic regimen. Quantitative bone cultures were performed throughout the 14-day period.
The Impacts of
msaABCR
on
sarA
-Associated Phenotypes Are Different in Divergent Clinical Isolates of Staphylococcus aureus
Authors: Rom Joseph S. , Ramirez Aura M. , Beenken Karen E. , Sahukhal Gyan S. , Elasri Mohamed O. , Smeltzer Mark S.
Published: November 2019

The staphylococcal accessory regulator (
sarA
) plays an important role in
Staphylococcus aureus
infections, including osteomyelitis, and the
msaABCR
operon has been implicated as an important factor in modulating expression of
sarA
. Thus, we investigated the contribution of
msaABCR
to
sarA
-associated phenotypes in the
S. aureus
clinical isolates LAC and UAMS-1. Mutation of
msaABCR
resulted in reduced production of SarA and a reduced capacity to form a biofilm in both strains.
Structural Conservation and Diversity of PilZ-Related Domains
Authors: Galperin Michael Y. , Chou Shan-Ho
Published: November 2019

c-di-GMP is a ubiquitous bacterial second messenger that regulates motility, biofilm formation, and virulence of many bacterial pathogens. The PilZ domain is a widespread c-di-GMP receptor that binds c-di-GMP through its RXXXR and [D/N]
h
SXXG motifs; some PilZ domains lack these motifs and are unable to bind c-di-GMP. We used structural and sequence analysis to assess the diversity of PilZ-related domains and define their common features. We show that the hydrophobic residue
h
in the second position of the second motif is highly conserved; it may serve as a readout for c-di-GMP binding. We describe three principal classes of PilZ-related domains, canonical, tetramer-forming, and divergent PilZ domains, and propose the evolutionary pathways that led to the emergence of these PilZ types.
OCT angiography in optic disc drusen: comparison with structural and functional parameters
Authors: Engelke Hendrik , Shajari Mehdi , Riedel Julian , Mohr Niklas , Priglinger Siegfried G , Mackert Marc J
Published: November 2019

Background

Optic disc drusen (ODD) can cause retinal nerve fibre layer (RNFL) defects with progressive visual field (VF) loss. Microvascular changes are discussed as a cause. We measured the vessel density (VD) of the optic disc in ODD using optical coherence tomography angiography and compared it with a normal population. Another intent was to determine the sensitivity and correlations in comparison with functional (VF) and structural parameters (RNFL, minimum rim width (MRW), ganglion cell complex (GCC)).

Methods

We analysed the VD of 25 patients with ODD and an age-matched control population including 25 healthy participants using AngioVue (Optovue, Fremont, CA, USA). We obtained data about RNFL, GCC, Bruch’s membrane opening MRW (Spectralis HRA & OCT; Heidelberg Engineering, Germany) and VF (standard automated perimetry; SITA 24-2). Low image quality and pathologies interfering with the diagnostics were excluded. Parametric data were analysed using the t-test and non-parametric values using the Mann-Whitney U test. Linear regression analysis was used to determine correlations using the Bravais-Pearson test.

Results

The VD was significantly reduced in the ODD group especially the peripapillary capillary VD (n=45 vs 50 eyes; mean 43.15% vs 51.70%). Peripapillary RNFL thickness correlated with the VD significantly (r=0.902 (n=44), 0.901 (n=44), 0.866 (n=45)). The RNFL analysis showed a reduction in ODD, especially the superior hemisphere (mean 107 µm, 129 µm; 49 vs 50 eyes). The GCC was significantly lower in the ODD group (n=38 vs 40; mean 87 µm vs 98 µm). Positive correlation between the VD and the GCC was significant (n=37, r=0.532). There is a significant negative correlation (n=19; r=−0.726) between the VD and the pattern standard deviation (PSD).

Conclusion

This study reveals significant peripapillary microvascular changes in patients with ODD correlating with the RNFL and GCC reduction. There is a negative correlation between the PSD and the VD.
Development and implementation of electronic medical handovers across psychiatric hospitals: quality improvement initiative
Authors: Skelton Luke , Rogers Jonathan , Kalafatis Chris
Published: November 2019

A lack of integration between internal processes and failure to use the full potential of information technology (IT) systems is common in psychiatric hospitals. We aimed to reduce the number of out-of-hours medical errors by ensuring that there is consistent and transparent weekend medical handover by creating an electronic handover system that is easy to use, robust and embedded into the existing trust IT systems. We employed quality improvement (QI) methodology to address this issue.

After trialling in a single site followed by six cycles of improvement, the weekend medical handover system is now in use across four boroughs and has been integrated into trust policy. It has received qualitative and quantitative evidence of improvement, with 100% of doctors reporting the system improved patient care and a 64% (from 11 to 4 events/year) reduction in moderate, severe and catastrophic adverse incidents occurring out-of-hours within the older adult service (p=0.29, χ21.117).

The increasing number of complex patients with comorbid medical illness in psychiatric inpatient services demands robust handover systems similar to that of an acute trust. This QI work offers a template for achieving this across other psychiatric trusts and demonstrates the positive change that can be achieved.
Patterns of sexualised recreational drug use and its association with risk behaviours and sexual health outcomes in men who have sex with men in London, UK: a comparison of cross-sectional studies conducted in 2013 and 2016
Authors: Curtis Tyrone J , Rodger Alison J , Burns Fiona , Nardone Anthony , Copas Andrew , Wayal Sonali
Published: November 2019

Objective

London has one of the highest identified prevalence of chemsex (sexualised recreational drug use) among men who have sex with men (MSM) in Europe. We examine MSM’s patterns of chemsex and its association with HIV/STI risk behaviours, STI diagnoses and sexual healthcare-seeking behaviours, including if HIV testing behaviour met UK national guidelines (three monthly if engaging in chemsex).

Methods

Cross-sectional survey data from 2013 (n=905) and 2016 (n=739) were collected using anonymous, self-administered questionnaires from MSM recruited in commercial gay venues in London, UK. Descriptive and multivariable analyses, stratified by self-reported HIV status, were conducted. Adjusted prevalence ratios (aPR) with 95% CIs were calculated.

Results

Comparing the 2013 and 2016 surveys, chemsex prevalence in the past year remained stable, in both HIV-negative/unknown-status MSM (20.9% in 2013 vs 18.7% in 2016, p=0.301) and HIV-positive MSM (41.6% in 2013 vs 41.7% in 2016, p=0.992). Combined 2013–2016 data showed that compared with other MSM, those reporting chemsex were more likely to report HIV/STI risk behaviours, including condomless anal intercourse with serodifferent HIV-status partners (HIV-negative/unknown-status men: aPR 2.36, 95% CI 1.68 to 3.30; HIV-positive men: aPR 4.19, 95% CI 1.85 to 9.50), and STI diagnoses in the past year (HIV-negative/unknown-status men: aPR 2.10, 95% CI 1.64 to 2.69; HIV-positive men: aPR 2.56, 95% CI 1.57 to 4.20). 68.6% of HIV-negative/unknown-status men reporting chemsex attended sexual health clinics and 47.6% had tested for HIV more than once in the past year.

Conclusions

Chemsex in London MSM remained stable but high, particularly among HIV-positive men. Irrespective of HIV status, chemsex was associated with engagement in HIV/STI risk behaviours. Frequency of HIV testing in the past year among HIV-negative/unknown-status men was below national recommendations. Promoting combination prevention strategies, including three monthly HIV/STI testing, access to pre-exposure prophylaxis/antiretroviral treatment and behavioural interventions among MSM reporting chemsex, remains vital to address sexual health inequalities in MSM.
Constraining the parameters of high-dimensional models with active learning
Authors: Caron Sascha , Heskes Tom , Otten Sydney , Stienen Bob
Published: November 2019

Constraining the parameters of physical models with $$>5-10$$>5-10 parameters is a widespread problem in fields like particle physics and astronomy. The generation of data to explore this parameter space often requires large amounts of computational resources. The commonly used solution of reducing the number of relevant physical parameters hampers the generality of the results. In this paper we show that this problem can be alleviated by the use of active learning. We illustrate this with examples from high energy physics, a field where simulations are often expensive and parameter spaces are high-dimensional. We show that the active learning techniques query-by-committee and query-by-dropout-committee allow for the identification of model points in interesting regions of high-dimensional parameter spaces (e.g. around decision boundaries). This makes it possible to constrain model parameters more efficiently than is currently done with the most common sampling algorithms and to train better performing machine learning models on the same amount of data. Code implementing the experiments in this paper can be found on GitHub "Image missing"
Conformal GUT inflation, proton lifetime and non-thermal leptogenesis
Authors: Kumar K. Sravan , Moniz Paulo Vargas
Published: November 2019

In this paper, we generalize Coleman–Weinberg (CW) inflation in grand unified theories (GUTs) such as $$\text {SU}(5)$$SU(5) and $$\text {SO}(10)$$SO(10) by means of considering two complex singlet fields with conformal invariance. In this framework, inflation emerges from a spontaneously broken conformal symmetry. The GUT symmetry implies a potential with a CW form, as a consequence of radiative corrections. The conformal symmetry flattens the above VEV branch of the CW potential to a Starobinsky plateau. As a result, we obtain $$n_{s}\sim 1-\frac{2}{N}$$ns∼1-2N and $$r\sim \frac{12}{N^2}$$r∼12N2 for $$N\sim $$N∼ 50–60 e-foldings. Furthermore, this framework allow us to estimate the proton lifetime as $$\tau _{p}\lesssim 10^{40}$$τp≲1040 years, whose decay is mediated by the superheavy gauge bosons. Moreover, we implement a type I seesaw mechanism by weakly coupling the complex singlet, which carries two units of lepton number, to the three generations of singlet right handed neutrinos (RHNs). The spontaneous symmetry breaking of global lepton number amounts to the generation of neutrino masses. We also consider non-thermal leptogenesis in which the inflaton dominantly decays into heavy RHNs that sources the observed baryon asymmetry. We constrain the couplings of the inflaton field to the RHNs, which gives the reheating temperature as $$10^{6}\text { GeV}\lesssim T_{R}<10^{9}$$106GeV≲TR<109 GeV.
Brownian Motion and Quantum Mechanics
Authors: Tsekov Roumen
Published: November 2019

A theoretical parallel between the classical Brownian motion and quantum mechanics is explored via two stochastic sources. It is shown that, in contrast to the classical Langevin force, quantum mechanics is driven by turbulent velocity fluctuations with diffusive behavior. In the case of simultaneous action of the thermal and quantum noises, the quantum Brownian motion is described as well.
Homology and Cohomology of the Super Schrödinger Algebra S(1/1) with Coefficients in the Trivial Module
Authors: He Yan , Wu Yuezhu , Zhu Linsheng
Published: November 2019

In this paper we study the homology and cohomology groups of the super Schrödinger algebra [Formula: see text] in (1 + 1)-dimensional spacetime. We explicitly compute the homology groups of [Formula: see text] with coefficients in the trivial module. Then using duality, we finally obtain the dimensions of the cohomology groups of [Formula: see text] with coefficients in the trivial module.
(n + 2)-Angulated Quotient Categories
Authors: Zheng Qilian , Wei Jiaqun
Published: November 2019

The notion of [Formula: see text]-mutation pairs of subcategories in an n-exangulated category is defined in this article. When (Ƶ, Ƶ) is a [Formula: see text]-mutation pair in an n-exangulated category (C, [Formula: see text]), the quotient category Ƶ/[Formula: see text] carries naturally an (n+2)-angulated structure. This result generalizes a theorem of Zhou and Zhu for extriangulated categories.
Green Synthesis of Gold Nanoparticles Using Longan Polysaccharide and their Reduction of 4-nitrophenol and Biological Applications
Authors: Zhang Xiaoyu , Fan Liyuan , Cui Yanshuai , Cui Tianming , Chen Shengfu , Ma Guanglong , Hou Wenlong , Wang Longgang
Published: November 2019

The green synthesis of gold nanoparticles (Au NPs) for catalytic and biological applications has been drawing great attention. To compare with plant extracts, the polysaccharides may be good reducing and stabilizing agents. In this work, we describe the preparation of longan polysaccharide stabilized gold nanoparticles (Aun-LP NPs) by reduction of gold ions using a green synthetic method. The formation of gold nanoparticles (Au NPs) was confirmed by UV-Vis spectra. TEM showed that Au NPs had a small size (7.8–15.6[Formula: see text]nm) and were highly dispersed without any aggregation. XPS confirmed that the surface elemental composition of Aun-LP NPs was C, O, and Au. DLS demonstrated that Aun-LP NPs had good stability and negative zeta potential. In addition, Aun-LP NPs had high catalytic activity for the reduction of 4-nitrophenol. More importantly, Aun-LP NPs had ignorable cytotoxicity towards HeLa cells and showed good antioxidant activity. Taken together, the results indicated that longan polysaccharide can be used as reducing agents and stabilizers for the preparation of metallic nanoparticles, and the product had wide applications.
Concentration-Controlled and Phytic Acid-Assisted Synthesis of Self-Assembled LiFePO4 as Cathode Materials for Lithium-Ion Battery
Authors: Li Yin , Zhang Keyu , Chen Zhengjie , Wang Yunke , Wang Li , Liang Feng , Yao Yaochun
Published: November 2019

The olivine LiFePO4 with various morphologies and different growth lattice planes was prepared by a controllable hydrothermal method with changing precursor concentration and using phytic acid as phosphorus source. The microstructure, crystal orientation and electrochemical performance of the prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and charge–discharge tests. The results show that the morphologies of all samples change from spindle-like to hierarchical plate-like and then to long plate-like shape, and the main exposed facets transform from (100) to (001). This indicates that the precursor concentration and phytic acid play important roles in exposing facets and controlling the morphology of LiFePO4. In order to illustrate these phenomena, a reasonable assembly process is provided and the formation is explained. Li ion diffusion coefficient along [100] and [001] directions was calculated by using electrochemical impedance spectroscopy (EIS). The results show that the diffusion coefficient of (100) facet is higher than that of (001) facet, indicating a good electrochemical performance for (100) facet. In addition, the capacity test is carried out, which also confirms the above results. With the precursor concentration of 0.5[Formula: see text]M, the obtained LiFePO4 with self-assembled hierarchical structure, smaller size and (100) facet shows the best electrochemical performance: 162.1[Formula: see text]mAh/g at 0.1[Formula: see text]C and 112.4[Formula: see text]mAh/g at 10[Formula: see text]C. Using phytic acid as phosphorus source and controlling precursor concentration to prepare high performance LiFePO4 open up a new prospect for the production of cathode materials for lithium ion batteries.
A Personalized Music Recommender System Using User Contents, Music Contents and Preference Ratings
Authors: Su Ja-Hwung , Chin Chu-Yu , Liao Yi-Wen , Yang Hsiao-Chuan , Tseng Vincent S. , Hsieh Sun-Yuan
Published: November 2019

Recently, the advances in communication technologies have made music retrieval easier. Without downloading the music, the users can listen to music through online music websites. This incurs a challenging issue of how to provide the users with an effective online listening service. Although a number of past studies paid attention to this issue, the problems of new user, new item and rating sparsity are not easy to solve. To deal with these problems, in this paper, we propose a novel music recommender system that fuses user contents, music contents and preference ratings to enhance the music recommendation. For dealing with problem of new user, the user similarities are calculated by user profiles instead of traditional ratings. By the user similarities, the unknown ratings can be predicted using user-based Collaborative Filtering (CF). For dealing with problems of rating sparsity and new items, the unknown ratings are initialized by acoustic features and music genre ratings. Because the unknown ratings are initially imputed, the rating data will be enriched. Thereupon, the user preference can be predicted effectively by item-based CF. The evaluation results show that our proposed music recommender system performs better than the state-of-the-arts methods in terms of Root Mean Squared Error.
Measuring and Monte Carlo Modelling of X-Ray and Gamma-Ray Attenuation in Personal Radiation Shielding Protective Clothing
Authors: Kozlovska Michaela , Solc Jaroslav , Otahal Petr
Published: November 2019

A collection of personal protective equipment (PPE), suitable for use in case of accident in nuclear facilities or radiological emergencies, was gathered at the National Institute for Nuclear, Chemical and Biological Protection, Czech Republic. The shielding characteristics of the various PPE materials were measured via narrow geometry spectral attenuation measurements with point radionuclide sources covering a broad range of photon energies. Photon relative penetration and attenuation for relevant energies of the spectra were the principal experimentally determined quantities for tested PPE. Monte Carlo simulations in the MCNPX™ code were carried out to determine photon attenuation for respective energies in the tested PPE, and the results were compared to those determined experimentally. Energy depositions in a unit volume of an ORNL phantom were simulated in a radioactive aerosols atmospheric environment to determine effective doses both for the whole body and in various organs in the human torso during exposure to different dispersed radioactive aerosols while wearing one of the PPE protecting against X- and gamma-ray. This work aimed to determine the effective dose and its decrease for individual PPE protecting against X- and gamma-ray.
Assessment of Corneal Pachymetry Distribution and Morphologic Changes in Subclinical Keratoconus with Normal Biomechanics
Authors: Song Peng , Yang Kaili , Li Pei , Liu Yu , Liang Dengfeng , Ren Shengwei , Zeng Qingyan
Published: November 2019

Purpose. To investigate the pachymetry distribution of central cornea and morphologic changes in subclinical keratoconus with normal biomechanics and determine their potential benefit for the screening of very early keratoconus. Methods. This retrospective comparative study was performed in 33 clinically unaffected eyes with normal topography and biomechanics from 33 keratoconus patients with very asymmetric ectasia (VAE-NTB; Corvis Biomechanical Index defined) and 70 truly normal eyes from 70 age-matched subjects. Corneal topographic, tomographic, and biomechanical metrics were measured using Pentacam and Corvis ST. The distance and pachymetry difference between the corneal thinnest point and the apex were defined as DTCP-Apex and DPTCP-Apex, respectively, to evaluate the pachymetry distribution within the central cornea. The discriminatory power of metrics was analysed via the receiver operating characteristic curve. A logistic regression analysis was used to establish predictive models. Results. The parameters, DTCP-Apex and DPTCP-Apex, were significantly higher in VAE-NTB than those in normal eyes. For differentiating normal and VAE-NTB eyes, the Belin-Ambrósio deviation (BAD-D) showed the largest area under the curve (AUC; 0.799), followed by ARTmax (0.798), DTCP-Apex (0.771), tomography and biomechanical index (0.760), maximum pachymetry progression index (PPImax, 0.756), DPTCP-Apex (0.753), and back eccentricity (B_Ecc, 0.707) with no statistically significant differences among these AUCs. In the VAE-NTB group, the parameter B_Ecc was significantly and positively correlated with DTCP-Apex (P=0.011) and DPTCP-Apex (P=0.035), whereas the posterior elevation difference had a significant positive association with DPTCP-Apex (P=0.042). A model using the indices DTCP-Apex, B_Ecc, PPImax, and index of height asymmetry demonstrated the highest AUC of 0.846 with 91.43% specificity. Conclusions. Abnormal pachymetry distribution within the central cornea and subtle morphologic changes are detectable in subclinical keratoconus with normal biomechanics. This may improve VAE-NTB eyes detection.
Mining TCGA Database for Tumor Microenvironment-Related Genes of Prognostic Value in Hepatocellular Carcinoma
Authors: Deng Zhenfeng , Wang Jilong , Xu Banghao , Jin Zongrui , Wu Guolin , Zeng Jingjing , Peng Minhao , Guo Ya , Wen Zhang
Published: November 2019

Hepatocellular carcinoma (HCC) is one of the most common and lethal malignancies. Recent studies reveal that tumor microenvironment (TME) components significantly affect HCC growth and progression, particularly the infiltrating stromal and immune cells. Thus, mining of TME-related biomarkers is crucial to improve the survival of patients with HCC. Public access of The Cancer Genome Atlas (TCGA) database allows convenient performance of gene expression-based analysis of big data, which contributes to the exploration of potential association between genes and prognosis of a variety of malignancies, including HCC. The “Estimation of STromal and Immune cells in MAlignant Tumors using Expression data” algorithm renders the quantification of the stromal and immune components in TME possible by calculating the stromal and immune scores. Differentially expressed genes (DEGs) were screened by dividing the HCC cohort of TCGA database into high- and low-score groups according to stromal and immune scores. Further analyses of functional enrichment and protein-protein interaction networks show that the DEGs are mainly involved in immune response, cell adhesion, and extracellular matrix. Finally, seven DEGs have significant association with HCC poor outcomes. These genes contain FABP3, GALNT5, GPR84, ITGB6, MYEOV, PLEKHS1, and STRA6 and may be candidate biomarkers for HCC prognosis.
Grouting Reinforcement Technique in Wind Oxidation Zone by Power Law Superfine Cement Slurry Considering the Time‐Varying Rheological Parameters
Authors: Zhu Dengxing , Guo Yu , Wang Wei , Guo Gangye , An Tieliang
Published: November 2019

With the recovery of the wind oxidation zone in 13116 working face of Gubei Coal Mine as the engineering background, the occurrence condition of coal seam and the bedrock wind oxidation zone characteristics were analyzed. On this basis, the time‐varying rheological parameters of superfine cement slurry and the permeability characteristic parameters of roof strata in wind oxidation zone were measured; then, a grout diffusion equation was established with the parameters obtained previously for the permeability characteristics of roof strata in the wind oxidation zone of Gubei Coal Mine. The grouting design was applied in actual engineering projects and its engineering effect has been proved to be satisfactory. The results indicate that superfine cement slurry whose water‐cement ratio is 0.6 is a typical power‐law slurry consistent with time‐varying rheological parameters. It has better rheological properties during pumpable period, and its rheological parameters can be controlled by highly dispersive nano‐SiO2 and polycarboxylate superplasticizer. For grouting in wind oxidized zone, comprehensive consideration must be given to effective permeability Ke, porosity  ∅ , and time‐varying rheological parameters c0, k, and n. To realize effective diffusion of grouting in coal and rock mass, grouting pressure and diffusion time must be reasonably designed rather than excessively increased.
Determinants of Maternal Insulin Resistance during Pregnancy: An Updated Overview
Authors: Kampmann Ulla , Knorr Sine , Fuglsang Jens , Ovesen Per
Published: November 2019

Insulin resistance changes over time during pregnancy, and in the last half of the pregnancy, insulin resistance increases considerably and can become severe, especially in women with gestational diabetes and type 2 diabetes. Numerous factors such as placental hormones, obesity, inactivity, an unhealthy diet, and genetic and epigenetic contributions influence insulin resistance in pregnancy, but the causal mechanisms are complex and still not completely elucidated. In this review, we strive to give an overview of the many components that have been ascribed to contribute to the insulin resistance in pregnancy. Knowledge about the causes and consequences of insulin resistance is of extreme importance in order to establish the best possible treatment during pregnancy as severe insulin resistance can result in metabolic dysfunction in both mother and offspring on a short as well as long-term basis.