bluuebunny/crossref_metadata_2025 huggingface dataset:
The significance of early breastfeeding experiences on breastfeeding self‐efficacy one week postpartum
Authors: Nilsson Ingrid M. S. , Kronborg Hanne , Rahbek Keren , Strandberg‐Larsen Katrine
Published: March 2020

Many new mothers do not reach their breastfeeding goals. Breastfeeding self‐efficacy is a modifiable determinant influenced by prior and new breastfeeding experiences. More knowledge about factors associated with early breastfeeding experiences and breastfeeding self‐efficacy would allow us to qualify breastfeeding counselling and increase breastfeeding duration. This study aimed to identify prevalence and factors associated with early negative breastfeeding experience, low breastfeeding self‐efficacy in the first week postpartum, and drop in self‐efficacy from late pregnancy to early postpartum period. A prospective longitudinal study was performed in Denmark from 2013 to 2014, including 2, 804 mothers.

Results showed that 1 week postpartum almost 10% of mothers had negative breastfeeding experiences, 36% had low breastfeeding self‐efficacy, and 26% drop in self‐efficacy from pregnancy. Negative breastfeeding experiences were significantly associated with epidural analgesia, interrupted skin‐to‐skin contact immediately postpartum, short previous breastfeeding duration, and lacking social support. Low breastfeeding self‐efficacy was associated with low breastfeeding intention, short previous breastfeeding duration, and negative breastfeeding experiences in the first week postpartum. Finally, significant associations of drop in breastfeeding self‐efficacy from late pregnancy were no or short education, early negative breastfeeding experiences, prior short breastfeeding duration, and low general breastfeeding self‐efficacy in pregnancy. Negative breastfeeding experiences in the first week postpartum is crucial for maternal breastfeeding self‐efficacy 1 week following birth. It is important to identify and support mothers at risk of negative breastfeeding experiences in the first week following birth and address factors that might increase the probability of early successful breastfeeding experiences.
Sex‐specific telomere length and dynamics in relation to age and reproductive success in Cory’s shearwaters
Authors: Bauch Christina , Gatt Marie Claire , Granadeiro José Pedro , Verhulst Simon , Catry Paulo
Published: March 2020

Individuals in free‐living animal populations generally differ substantially in reproductive success, lifespan and other fitness‐related traits, but the molecular mechanisms underlying this variation are poorly understood. Telomere length and dynamics are candidate traits explaining this variation, as long telomeres predict a higher survival probability and telomere loss has been shown to reflect experienced “life stress.” However, telomere dynamics among very long‐lived species are unresolved. Additionally, it is generally not well understood how telomeres relate to reproductive success or sex. We measured telomere length and dynamics in erythrocytes to assess their relationship to age, sex and reproduction in Cory's shearwaters (Calonectris borealis), a long‐lived seabird, in the context of a long‐term study. Adult males had on average 231 bp longer telomeres than females, independent of age. In females, telomere length changed relatively little with age, whereas male telomere length declined significantly. Telomere shortening within males from one year to the next was three times higher than the interannual shortening rate based on cross‐sectional data of males. Past long‐term reproductive success was sex‐specifically reflected in age‐corrected telomere length: males with on average high fledgling production were characterized by shorter telomeres, whereas successful females had longer telomeres, and we discuss hypotheses that may explain this contrast. In conclusion, telomere length and dynamics in relation to age and reproduction are sex‐dependent in Cory's shearwaters and these findings contribute to our understanding of what characterises individual variation in fitness.
Wage‐led versus profit‐led demand: A comprehensive empirical analysis
Authors: Oyvat Cem , Öztunalı Oğuz , Elgin Ceyhun
Published: March 2020

This study investigates various economic factors’ impact in determining the relationship between functional income distribution and aggregate demand from both a theoretical and an empirical viewpoint. We base our analysis on a demand‐driven growth model for an open economy that allows for either profit‐led or wage‐led regimes. Our results strongly indicate that a higher level of trade openness is associated with a lower probability of being wage‐led. We find evidence that lower wage inequality makes an economy more wage‐led and that countries with a greater private credit‐to‐gross domestic product (GDP) ratio are more likely to be profit‐led.
Aquinas, Darwin and Natural Law: Teleology and Immutability of Species
Authors: Pienaar Sebastiana
Published: March 2020

Natural Law theory is the theory that nature has built within it a set of objective norms or laws which are universally applicable and can be discovered by reason. It is derived from nature rather than from the rules of society in determining an objectivist moral theory. It has a long history of tradition beginning with the ancient Greeks and Romans up to the present day.

The purpose of this essay is to argue Darwin's theory of natural law can be accommodated by Aquinas’ theory of natural law. The secondary literature of both figures is vast and changing, but this essay will mostly be restricted to looking at their primary texts on the topic. From this, it will be evident they shared many thoughts in common – the primary one being that morality begins with biology. There are objections to the compatibility of their theories, but space restricts me to addressing only two of them: teleology and immutability of species.
Understanding cortical pain perception in humans
Authors: Tobimatsu Shozo
Published: March 2020

Pain is a conscious experience and a highly subjective sensation with a complex and often non‐linear relationship between nociceptive input and pain perception. Our understanding of the neural correlates of pain perception in humans has increased significantly since the advent of neuroimaging. Relating neural activity changes to the varied pain experiences has led to the concept that cognition, emotion, context, and injury can separately influence pain perception. In this mini review, the current concept of the central pain mechanism (CPM) is described. First, the concept of the “pain matrix” is stated: Nociceptive stimuli elicit responses in an extensive cortical network including somatosensory, insular, and cingulate areas, as well as frontal and parietal areas. Then, electrophysiological assessments of the CPM are reviewed based on the literature and our recent studies. In particular, supraspinal (cortical) mechanisms for pain perception and pain relief are outlined. The insular cortex has key roles in sensory‐associated as well as cognitive‐associated processing for pain perception.
A QTL atlas for grain yield and its component traits in maize (Zea mays)
Authors: Zhou Zhipeng , Li Guoliang , Tan Siyu , Li Dongdong , Weiß Thea Mi , Wang Xiangfeng , Chen Shaojiang , Würschum Tobias , Liu Wenxin
Published: March 2020

Grain yield and its component traits are essential targets in maize breeding. These traits are genetically complex and controlled by a large number of quantitative trait loci (QTL). The aim of this study was to compile reported QTL and major genes for grain yield and its component traits in a QTL atlas, as a valuable resource for the maize community. To this end, 1,177 QTL related to maize yield were collected from 56 studies published between 1992 and 2018. These QTL were projected to genetic map “IBM2 2008 Neighbors”, which led to the identification of 135 meta‐QTL. Some genomic regions appear to be hotspots for yield‐related meta‐QTL, often affecting more than one of the investigated traits. Moreover, we catalogued 20 major maize loci associated with yield and identified 65 maize homologs of 21 rice yield‐related genes. Interestingly, we found that a significant proportion of them are located in meta‐QTL regions. Collectively, this study provides a reference for QTL fine‐mapping and gene cloning, as well as for molecular marker‐assisted breeding of yield‐related traits in maize.
Genome‐wide association mapping and genomic prediction of Fusarium head blight resistance, heading stage and plant height in winter rye (Secale cereale)
Authors: Gaikpa David Sewordor , Koch Silvia , Fromme Franz Joachim , Siekmann Dörthe , Würschum Tobias , Miedaner Thomas
Published: March 2020

Rye is a multi‐purpose cereal crop grown in Central and Eastern Europe as well as in Western Canada. Fusarium head blight (FHB) is one of the diseases that have a severe negative impact on rye, but knowledge about FHB resistance at the genomic level is totally missing in rye. The objective of this study was to elucidate the genetic architecture of FHB resistance in winter rye using genome‐wide association (GWA) mapping complemented by genomic prediction (GP) in comparison with marker‐assisted selection (MAS). Additionally, plant height and heading stage were analysed. A panel of 465 S1‐inbred lines of winter rye was phenotyped in three environments (location–year combinations) for FHB resistance by inoculation with Fusarium culmorum and genotyped with a 15k SNP array. Significant genotypic variation and high heritabilities were found for FHB resistance, heading stage and plant height. FHB did not correlate with heading stage, but was moderately correlated with plant height (r = −.52, p < .001) caused by some susceptible short inbred lines. The GWA scan identified 15 QTL for FHB resistance that jointly explained 74% of the genotypic variance. In addition, we detected 11 QTL for heading stage and 8 QTL for plant height, explaining 26% and 14% of the genotypic variance, respectively. A genome‐wide prediction approach resulted in 44% higher prediction abilities than marker‐assisted selection for FHB resistance. In conclusion, genomic approaches appear promising to improve and accelerate breeding for complex traits in winter rye.
Empathic accuracy and cognitions during conflict: An in‐depth analysis of understanding scores
Authors: Hinnekens Céline , Sillars Alan , Verhofstadt Lesley L. , Ickes William
Published: March 2020

Empathic accuracy research indicates that partners achieve only moderate success at reading each other's thoughts. The current study identifies specific patterns of online thought that contribute to empathic inaccuracy during conflict interactions. Married/cohabiting partners completed a conflict interaction and reported their own thoughts during video‐assisted recall of the interaction, also inferring the thoughts of the other partner. Content analysis of these online thoughts demonstrated a high degree of mindfulness about the process of communication, along with a perspective bias, in which partners tended to construe their own communication as constructive and the other partner's communication as avoidant and confrontational. Specific mind‐reading errors linked to both the thematic content and affective tone of online thought predicted lower overall empathic accuracy.
Evidence for physiological seed dormancy cycling in the woody shrub Asterolasia buxifolia and its ecological significance in fire‐prone systems
Authors: Collette J. C. , Ooi M. K. J.
Published: March 2020

Dormancy cycling is a key mechanism that contributes to the maintenance of long‐term persistent soil seed banks, but has not been recorded in long‐lived woody shrub species from fire‐prone environments. Such species rely on seed banks and dormancy break as important processes for post‐fire recruitment and recovery.

We used germination experiments with smoke treatments on fresh seeds and those buried for 1 year (retrieved in spring) and 1.5 years (retrieved the following late autumn) to investigate whether Asterolasia buxifolia, a shrub from fire‐prone south‐eastern Australia with physiologically dormant seeds, exhibited dormancy cycling.

All seeds had an obligation for winter seasonal temperatures and smoke to promote germination, even after ageing in the soil. A high proportion of germination was recorded from fresh seeds. but germination after the first retrieval was significantly lower, despite high seed viability. After the second retrieval, germination returned to the initial level. This indicates a pattern of annual dormancy cycling; one of the few observations, to our knowledge, for a perennial species. Additionally, A. buxifolia’s winter temperature and smoke requirements did not change over time, highlighting the potential for seeds to remain conditionally dormant (i.e. restricted to a narrow range of germination conditions) for long periods.

For physiologically dormant species, such as A. buxifolia, we conclude that dormancy cycling is an important driver of successful regeneration, allowing seed bank persistence, sometimes for decades, during fire‐free periods unsuitable for successful recruitment, while ensuring that a large proportion of seeds are available for recruitment when a fire occurs.
Deterring rodent seed‐predation using seed‐coating technologies
Authors: Taylor Justin B. , Cass Kristina L. , Armond David N. , Madsen Matthew D. , Pearson Dean E. , St. Clair Samuel B.
Published: March 2020

With many degraded environments undergoing restoration efforts, there is a growing need for the optimization of direct seeding practices. Seeds planted on wildlands are often consumed by rodents, leading to reduced plant establishment. Coating seeds in rodent aversive products may prevent seed‐predation. We tested 10 seed‐coating formulations containing products expected to deter rodents, namely: ghost and cayenne pepper powders; essential oils from bergamot, neem, and pine; methyl‐nonyl‐ketone, anthraquinone, activated carbon, beta‐cyclodextrin, and a blank coating containing no rodent deterrents to serve as a control treatment. Each treatment was applied to Pseudoroegneria spicata (bluebunch wheatgrass) seeds. These seeds germinated similarly to uncoated control seeds unless the coating contained methyl‐nonyl‐ketone which reduced germination. When seeds were offered to Ord's kangaroo rats (Dipodomys ordii), they strongly avoided the treatments in favor of uncoated control seeds. Notably, the blank coating, lacking active ingredients, still elicited 99% avoidance. However, these results indicated behavior when alternative food sources are readily available, a scenario rare in nature. To address this, a second feeding experiment was conducted to observe D. ordii's behavior under calorie‐restricted conditions. D. ordii were subjected to a fast period, then offered only one treatment. Under these conditions, many subjects chose to consume coated seeds, but to a lesser degree than subjects offered control seeds. Seeds coated in ghost pepper, neem oil, and activated carbon reduced consumption by 47–50%. Given these lab results, we would expect these treatments to increase native plant establishment following the direct seeding of wildlands by protecting seeds from rodent predation.
Termodynamics
Authors: Wolverton Mark
Published: March 2020

We humans like to congratulate ourselves for our ingenuity. Yet nature’s passive designs often outperform our expensive, energy-hungry technologies. And while engineers and architects can improve their designs by mimicking the natural world, nature always has another lesson to teach. That has certainly been the case for termites and air conditioning. This study highlights what engineers and architects can learn from termites about heating and cooling.
Droplet Impacting on a Hydrophobic Surface: Influence of Surface Wetting State on Droplet Behavior
Authors: Abubakar Abba Abdulhamid , Yilbas Bekir Sami , Hassan Ghassan , Al-Qahtani Hussain , Ali Haider , Al-Sharafi Abdullah
Published: March 2020

Water droplet impacting onto a hydrophobic surface is considered and the influence of the surface wetting state on the droplet dynamics is examined. Pressure variation in the impacting droplet is predicted numerically using the level set model. The droplet spreading and the retraction on the hydrophobic surface are assessed for various wetting states of the hydrophobic surface. Experiment is carried out to validate the predictions of the droplet shape and the restitution coefficient. It is found that predictions of impacting droplet shape and the restitution coefficient agree with those obtained from the experiment. The local pressure peaks formed in the droplet fluid, particularly in the retraction period, causes alteration of the droplet vertical height and the shape. Droplet spreading is influenced by the wetting state of the hydrophobic surface; hence, increasing contact angle of the hydrophobic surface lowers the spreading diameter of the droplet on the surface. The transition time of the droplet changes with the wetting state of the hydrophobic surface such that increasing droplet contact angle reduces the transition time of the droplet on the surface. The droplet remains almost round after the first bounding for large contact angle hydrophobic surface.
Magnetic Resonance Compatible Knee Extension Ergometer
Authors: Jaber Youssef , Jimenez Francisco Ericber , Bartlett Miles F. , Fitzgerald Liam F. , Kent Jane A. , Sup Frank C.
Published: March 2020

A magnetic resonance (MR) compatible ergometer has been developed to study contracting lower limb muscles during acquisition of MR spectroscopy data, a technique to noninvasively measure metabolic energy in muscle tissue. Current active and passive MR-compatible ergometer designs lack torque or velocity control to allow precise mechanical measurements during isotonic and isokinetic contractions; incorporating load and velocity controllers while maintaining MR-compatibility is the main challenge. Presented in this paper is the design and evaluation of an MR-compatible ergometer designed to control knee torque or velocity up to 420 N·m and 270 deg/s and is able to operate in a 3 Tesla magnetic field. The ergometer comprising of a passive component with no electronics or ferrous materials is located inside the bore of the scanner. The active component with the electronics and actuator located outside of the magnetic field in an adjacent room. The active components connect to the passive components via a cable that passes through the waveguide, a hole in the wall of the scanner room. System evaluations were performed and human subject evaluations were performed that measured the mechanical performance and show the mean percent errors below 9% in isotonic and 2% in isokinetic conditions.
Thermodynamic Cycle Analysis of an Automotive Internal Combustion Engine With the Characteristics of the Commercial BMW N54 Spark-Ignition Model
Authors: Douvartzides Savvas , Karmalis Ioannis , Ntinas Nikolaos
Published: March 2020

An analytical method is presented for the thermodynamic analysis of an automotive internal combustion engine with the characteristics of the commercial BMW N54 spark-ignition model. A 3-L displacement volume, six in-line cylinder, four-stroke gasoline engine is considered with two 0.57 bar boost pressure turbochargers and an air-to-air intercooler. Thermodynamic, fluid flow, and heat transfer phenomena are mathematically analyzed to provide results on the chemical composition of the cylinder gases, on their temperature and pressure, on the amount and properties of the residual exhaust gases, on the volumetric and mechanical efficiencies, on the specific fuel consumption, the torque and brake power output, the thermal efficiency, and the energy balance of the engine. The analysis provides results in very close agreement with the actual torque and brake power characteristics reported by the BMW manufacturer.
Mathematical Model of the Solar Pyrolysis of Biomass
Authors: Kaczor Zuzanna , Buliński Zbigniew , Werle Sebastian
Published: March 2020

The paper presents a two-dimensional computational fluid dynamics (CFD) model of lab-scale fixed-bed pyrolytic reactor. The goal of the work was to verify assumptions regarding construction and operating parameters of the pyrolytic reactor and examining heat transfer conditions and the final temperature distribution in the system taking into account the endothermic pyrolysis reactions occurrence. The impact of the most important numerical parameters on simulation results was also investigated. Model was prepared in ansys fluent 18.2 software. The studies have shown large temperature gradients both in the biomass deposit and at the reactor walls. The analysis has confirmed the validity of the proposed reactor construction concept and allowed to specify the range of thermal power value necessary for obtaining the pyrolysis process in a system with given properties and dimensions. Increasing the heat flux supplying the reactor from 160 to 480 W caused acceleration and intensification of biomass thermal decomposition, while the average final bed temperature after 10 min of heating in each case was reaching similar level. Low thermal conductivity of the bed and strong heat absorption due to pyrolysis suppress heat transfer through the bed, which causes significant temperature differences between the warmest and coldest regions of the bed. However, temperature unevenness and hence the unevenness of the pyrolysis process can provide favorable conditions for measuring the gas composition leaving the reactor due to the relatively balanced time stream of pyrolysis gases.
Performance Analysis of a Cascading Adsorption Cycle Powered by High-Temperature Heat Sources for Low-Temperature Cooling in Hot Climates
Authors: Abbaz Dalila , Chaker Abla , Bourouis Mahmoud
Published: March 2020

Cascade adsorption refrigeration technology using high-temperature driving heat is a very promising option for low-temperature cooling applications due to the large temperature difference between the heat source and the cold distributed. The present work carried out a feasibility and parametric study in order to analyze the functioning of a cascading adsorption cycle using the working pair zeolite/ammonia in beds operating at high temperatures and activated carbon/ammonia in those operating at low temperatures. At the nominal thermal conditions, namely, heating, condensing, and evaporating temperatures of 280 °C, 35 °C, and (−5) °C, respectively, the coefficient of performance (COP) and the specific refrigerating capacity (SCP) of the cycle were 0.53 and 67.1 W/kg. When the driving temperature is varied from 260 °C to 320 °C, the COP increases by 57% and the SCP by 36%. The performance of the cascading adsorption cycle at negative evaporating temperatures is very satisfactory.
Guide to making XPS measurements on nanoparticles
Authors: Baer Donald R.
Published: March 2020

This guide briefly summarizes issues and considerations important for the use of x-ray photoelectron spectroscopy (XPS) for characterizing nanoparticles, which are important in many areas of science and technology. Because the surfaces play a major role in determining nanoparticle behaviors, XPS is an increasingly useful tool for understanding their properties, including addressing variations and nonreproducibility issues associated with these materials. The unusual physical and chemical behaviors of these particles must be considered in preparing and characterizing these materials. This guide is one of a series intended to highlight the best practices in the use of XPS.
Selective atomic layer etching of HfO2 over silicon by precursor and substrate-dependent selective deposition
Authors: Lin Kang-Yi , Li Chen , Engelmann Sebastian , Bruce Robert L. , Joseph Eric A. , Metzler Dominik , Oehrlein Gottlieb S.
Published: March 2020

The early work of John Coburn and Harold Winters revealed a synergistic effect in ion-enhanced Si etching by the concurrent irradiation of Ar+ and XeF2. This finding provided an important foundation for the development of plasma dry etching processes. The experimental results of Coburn and Winters also found effects that are useful for the development of atomic layer etching (ALE) processes characterized by a self-limited etch rate. ALE approaches are widely established and can be utilized in either directional or isotropic etching by employing proper surface modification and product removal steps. Nevertheless, the development of material selective ALE processes is still limited. An approach that combines substrate-selective deposition with etching opens a new processing window for selective ALE. The authors studied the deposition behavior of mixtures of methane (CH4) with trifluoromethane (CHF3) and mixtures of methane with octafluorocyclobutane (C4F8) on HfO2 and Si surfaces. The experimental results show that a CH4/C4F8 mixture produces a comparable fluorocarbon (FC) deposition thickness on both HfO2 and Si during the deposition step. In contrast, a CH4/CHF3 mixture deposits an FC film on Si, whereas it fluorinates the HfO2 surface with negligible FC deposition. Utilizing these behaviors allows for an ALE process based on CH4/CHF3 for selective removal of HfO2 over Si. Surface characterization data that provide mechanistic insights into these processes are also provided and discussed.
Effects of spatial elements and sound sources on sound field in Main Hall of Chinese Buddhist temple
Authors: Zhang Dongxu , Lai Ruipeng , Zhang Mei , Kang Jian
Published: March 2020

In Chinese Han Buddhist temples, the Main Hall is the paramount indoor religious location, for which acoustic quality is very important for several Buddhist rites held within; however, the sound field in the Main Hall has not yet been analyzed scientifically. By combining sound field measurement with acoustic simulation, this study investigated the effects of spatial elements and sound source characteristics in a Main Hall, revealing that both fabric sound absorbers and Buddha statues mounted within had a pronounced effect on the sound field. Using an acoustic model of the Main Hall of the Xiantong Temple as an example, when various fabric sound absorbers were removed, the mid-frequency reverberation time (T30m) and mid-frequency early decay time (EDTm) increased by 32.3% and 46.8%, respectively. When fabric sound absorbers and Buddha statues were removed, the sound pressure level was not significantly affected. The form of the roof did not significantly impact the indoor sound field. The directivity of the sound sources did not significantly affect the T30m but did affect the EDTm and the speech transmission index (STI). When monks chanted sutras face-to-face, the STI was maximized. Additionally, changing the positions of sound sources moderately affected the EDT and STI.
Antecedents and Consequences of Student-Athletes’ Identity Profiles in Upper Secondary School
Authors: Moazami-Goodarzi Ali , Sorkkila Matilda , Aunola Kaisa , Ryba Tatiana V.
Published: March 2020

This study examined the identity profiles that upper secondary school Finnish student-athletes show and the extent to which these profiles were associated with their athletic and academic achievements and withdrawal from sports and school. A total of 391 adolescent athletes (51% female) completed assessments of student and athletic identity four times during their time in upper secondary school. Using growth mixture modeling, three groups were identified: dual identity (77%), changing identity (5%), and athletic identity (18%). The higher the academic achievement was at Time 1, the more likely the athletes were to show a dual identity than an athletic identity profile. Similarly, athletes with dual identity showed higher subsequent academic achievement at Time 4 than those with an athletic identity profile. Finally, athletes with dual identity were more likely and athletes with athletic identity less likely to withdraw from sport activities during upper secondary school than would be expected by chance.
Managing a Professional Sport Franchise: An Extended Case Approach to Learning
Authors: Snelgrove Ryan , Wood Laura , Wigfield Dan
Published: March 2020

This article describes the use of an extended case that simulates the front-office management of a National Basketball Association franchise during the off-season. Undergraduate students in an introduction to sport management course are tasked with making a series of sequential and interconnected decisions over a semester related to hiring a coach, producing a press release and press conference, analyzing player performance, creating a turnaround plan, managing a roster, establishing a culture following change, and relaunching the team’s brand. The benefits of this approach include the application of knowledge to practice, an understanding of a sport sector, making decisions in teams, adapting to new organizational environments, understanding how to make sequential decisions, and understanding how decisions are interconnected over time and across departments.
Efficient tandem solar cells with solution-processed perovskite on textured crystalline silicon
Authors: Hou Yi , Aydin Erkan , De Bastiani Michele , Xiao Chuanxiao , Isikgor Furkan H. , Xue Ding-Jiang , Chen Bin , Chen Hao , Bahrami Behzad , Chowdhury Ashraful H. , Johnston Andrew , Baek Se-Woong , Huang Ziru , Wei Mingyang , Dong Yitong , Troughton Joel , Jalmood Rawan , Mirabelli Alessandro J. , Allen Thomas G. , Van Kerschaver Emmanuel , Saidaminov Makhsud I. , Baran Derya , Qiao Qiquan , Zhu Kai , De Wolf Stefaan , Sargent Edward H.
Published: March 2020

Growing perovskite on textured silicon

Wide–band gap perovskites could boost the efficiency of silicon solar cells by forming tandem cells, but usually the perovskite must be grown on a smoothed side of the silicon cell because the material grown on the rough light-trapping side often does not fully coat the silicon surface and its rough texture is prone to phase separation. Hou
et al.
grew thick films of a perovskite with a band gap of ∼1.68 electron volts and used a passivant, 1-butanethiol, to limit its phase separation. The tandem cells had a certified power conversion efficiency of 25.7% and had negligible losses after 400 hours of operation.

Science
, this issue p.
1135
Triple-halide wide–band gap perovskites with suppressed phase segregation for efficient tandems
Authors: Xu Jixian , Boyd Caleb C. , Yu Zhengshan J. , Palmstrom Axel F. , Witter Daniel J. , Larson Bryon W. , France Ryan M. , Werner Jérémie , Harvey Steven P. , Wolf Eli J. , Weigand William , Manzoor Salman , van Hest Maikel F. A. M. , Berry Joseph J. , Luther Joseph M. , Holman Zachary C. , McGehee Michael D.
Published: March 2020

Tuning band gaps with three halides

Tandem solar cells can boost solar cell efficiency by using two active layers to absorb the solar spectrum more completely, provided that the two cells are current-matched. Inorganic-organic perovskites tuned to the appropriate wide band gap (∼1.7 electron volts) as top cells that contained iodine and bromine or bromine and chlorine have short carrier diffusion lengths and undergo photo-induced phase segregation. Xu
et al.
now report a method for incorporating chloride that allows for fabrication of stable triple-halide perovskites with a band gap of 1.67 electron volts. Two-terminal tandem silicon solar cells made with this material had a power conversion efficiency of 27%.

Science
, this issue p.
1097
A scalable realization of local U(1) gauge invariance in cold atomic mixtures
Authors: Mil Alexander , Zache Torsten V. , Hegde Apoorva , Xia Andy , Bhatt Rohit P. , Oberthaler Markus K. , Hauke Philipp , Berges Jürgen , Jendrzejewski Fred
Published: March 2020

Gauge invariance with cold atoms

There is considerable interest in developing quantum computational technologies that can simulate a series of physical phenomena inaccessible by classical computers. Mil
et al.
propose a modular scheme for quantum simulation of a U(1) lattice gauge theory based on heteronuclear spin-changing collisions in a mixture of two bosonic quantum gases isolated in single wells of a one-dimensional optical lattice. They engineered the elementary building block for a single well and demonstrate its reliable operation that preserves the gauge invariance. The potential for scalability of the proposed scheme opens up opportunities to address challenges in quantum simulating the continuum limit of the gauge theories.

Science
, this issue p.
1128
Origins and clonal convergence of gastrointestinal IgE
+
B cells in human peanut allergy
Authors: Hoh Ramona A. , Joshi Shilpa A. , Lee Ji-Yeun , Martin Brock A. , Varma Sushama , Kwok Shirley , Nielsen Sandra C. A. , Nejad Parastu , Haraguchi Emily , Dixit Priya S. , Shutthanandan Swetha V. , Roskin Krishna M. , Zhang Wenming , Tupa Dana , Bunning Bryan J. , Manohar Monali , Tibshirani Robert , Fernandez-Becker Nielsen Q. , Kambham Neeraja , West Robert B. , Hamilton Robert G. , Tsai Mindy , Galli Stephen J. , Chinthrajah Rebecca S. , Nadeau Kari C. , Boyd Scott D.
Published: March 2020

Peanut-allergic patient GI tissues implicate local IgE class-switching and common IgH genetic rearrangements in pathogenesis.
Compounds with Therapeutic Potential against Novel Respiratory 2019 Coronavirus
Authors: Martinez Miguel Angel
Published: March 2020

Currently, the expansion of the novel human respiratory coronavirus (known as SARS-CoV-2 [severe acute respiratory syndrome coronavirus 2], COVID-2019 [coronavirus disease 2019], or 2019-nCoV [2019 novel coronavirus]) has stressed the need for therapeutic alternatives to alleviate and stop this new epidemic. The previous epidemics of infections by high-morbidity human coronaviruses, such as SARS-CoV in 2003 and the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, prompted the characterization of compounds that could be potentially active against the currently emerging novel coronavirus, SARS-CoV-2.
Vib-PT, an Aromatic Prenyltransferase Involved in the Biosynthesis of Vibralactone from
Stereum vibrans
Authors: Bai Na , Li Guo-Hong , Luo Shao-Liu , Du Liangcheng , Hu Qian-Yi , Xu Han-Ke , Zhang Ke-Qin , Zhao Pei-Ji
Published: March 2020

Vibralactone is a lead compound with a novel skeleton structure that shows strong inhibitory activity against pancreatic lipase. Vibralactone is not encoded by the genome directly but rather is synthesized from phenol, followed by prenylation and other enzyme reactions. Here, we used an RNA silencing approach to identify and characterize a prenyltransferase in a basidiomycete species that is responsible for the synthesis of vibralactone. The identified gene,
vib-PT
, was expressed in
Escherichia coli
to obtain a soluble and enzymatically active fusion Vib-PT protein.
In vitro
characterization of the enzyme demonstrated the catalytic mechanism of prenylation and broad substrate range for different aromatic acceptors and prenyl donors. These characteristics highlight the possibility of Vib-PT to generate prenylated derivatives of aromatics and other compounds as improved bioactive agents or potential prodrugs.
Development of a New Scoring System To Accurately Estimate Learning Outcome Achievements via Single, Best-Answer, Multiple-Choice Questions for Preclinical Students in a Medical Microbiology Course
Authors: Dangprapai Yodying , Ngamskulrungroj Popchai , Senawong Sansnee , Ungprasert Patompong , Harun Azian
Published: March 2020

During the preclinical years, single-best-answer multiple-choice questions (SBA-MCQs) are often used to test the higher-order cognitive processes of medical students (such as application and analysis) while simultaneously assessing lower-order processes (like knowledge and comprehension). Consequently, it can be difficult to pinpoint which learning outcome has been achieved or needs improvement. We developed a new scoring system for SBA-MCQs using a step-by-step methodology to evaluate each learning outcome independently. Enrolled in this study were third-year medical students (n= 316) who had registered in the basic microbiology course at the Faculty of Medicine, Siriraj Hospital, Mahidol University during the academic year 2017. A step-by-step SBA-MCQ with a new scoring system was created and used as a tool to evaluate the validity of the traditional SBA-MCQs that assess two separate outcomes simultaneously. The scores for the two methods, in percentages, were compared using two different questions (SBA-MCQ1 and SBA-MCQ2). SBA-MCQ1 tested the students’ knowledge of the causative agent of a specific infectious disease and the basic characteristics of the microorganism, while SBA-MCQ2 tested their knowledge of the causative agent of a specific infectious disease and the pathogenic mechanism of the microorganism. The mean score obtained with the traditional SBA-MCQs was significantly lower than that obtained with the step-by-step SBA-MCQs (85.9% for the traditional approach versus 90.9% for step-by-step SBA-MCQ1;p< 0.001; and 81.5% for the traditional system versus 87.4% for step-by-step SBA-MCQ2;p< 0.001). Moreover, 65.8% and 87.8% of the students scored lower with the traditional SBA-MCQ1 and the traditional SBA-MCQ2, respectively, than with the corresponding sets of step-by-step SBA-MCQ questions. These results suggest that traditional SBA-MCQ scores need to be interpreted with caution because they have the potential to underestimate the learning achievement of students. Therefore, the step-by-step SBA-MCQ is preferable to the traditional SBA-MCQs and is recommended for use in examinations during the preclinical years.
A Multiweek Project Examining the Chemotactic Behavior of Tetrahymena in an Undergraduate Biology Laboratory
Authors: Hongo Rachel , Grammer Robert T. , Barton Christopher E.
Published: March 2020

A multi-week laboratory project has been developed to incorporate elements of student investigation, chemotactic behavior of protists, and genetic effects on chemotactic activity of Tetrahymena.  The chemotaxis assay is based on spectrophotometric detection of protist-induced light scattering as cells migrate into a density gradient containing a known attractant. The three-week project consists of an introductory chemotaxis assay, investigation of dose-response effects, and culminates with the exploration of a Tetrahymena genetic mutant with known defects in motility.  Additionally, this project incorporates a microscopic investigation of cellular structure and swimming behavior of mutant and wild-type cells.  Students have responded well to the nature of the project, displaying clear understanding of the mechanism of the assay as well as the response of the protists to environmental manipulation and the molecular defects in the mutant cells.
Scientific Writing Workshop Improves Confidence in Critical Writing Skills among Trainees in the Biomedical Sciences
Authors: Wortman-Wunder Emily , Wefes Inge
Published: March 2020

Written communication is a key research skill, yet the current model of pre- and postdoctoral training in the biomedical sciences lacks consistent formal training in this area, leading to crises of confidence when tackling research writing. A 15-hour non-credit workshop, “Secrets of Successful Scientific Writing,” was developed in collaboration with an experienced instructor of scientific writing. The workshop consisted of six 2.5-hour sessions and was offered six times; a total of 126 trainees attended over these six offerings. Topics included strategies to engage the audience, principles of psychological linguistics to maximize sentence effectiveness, conventions of biomedical journal writing, technical writing and the history of scientific publishing, and two sessions on grant writing. Student confidence in and familiarity with targeted writing skills were assessed by self-evaluation questions administered immediately before and after each session. The workshop was determined to be effective at improving the confidence of participants regarding specific writing skills in the biomedical sciences, with all but two of the measures showing that the workshop had a large effect size. We conclude that a short, structured workshop can help improve the confidence and knowledge of pre- and postdoctoral writers, preparing them to better meet the writing challenges of their professional careers.
Testing the “Grandma Hypothesis”: Characterizing Skin Microbiome Diversity as a Project-Based Learning Approach to Genomics
Authors: Pérez-Losada Marcos , Crandall Kelly M. , Crandall Keith A.
Published: March 2020

The constantly evolving nature of genomics provides new challenges for students in Public Health as they try to understand how genomic information relates to health and disease. As Public Health curricula attempt to keep pace with the most recent advances in genomics, students should gain experience with analyzing genomic data and applying genomic tools to the study of health-related issues. To advance undergraduate and graduate student education and provide a more comprehensive view of genomics, we developed an educational project including both pedagogic and research components to characterize skin microbial communities (microbiomes) using targeted amplicon sequencing of their genomes (metataxonomy). All students completed the lab procedures, analyzed 16S rRNA genomic data (formative assessments), and wrote a five-page scientific report summarizing and discussing their results (summative assessment). Student grades for the summative assessment ranged from 31.5 to 40 (out of 40) points. They also successfully completed two practicums (problem sets) focused on microbiome sequence data and responded to 12 minute-papers related to genomic topics covered in class. In all these exercises the 2019 students outperformed 2018 students, who did not participate in this educational lab project. By fulfilling all the requirements of this project-based learning experience, students better understood the complexity of genomics and acquired a valuable set of marketable experience and skills in molecular technologies, bioinformatics and statistics (quantitative skills). Additionally, students were able to generate new valuable microbial 16S rRNA genomic data and test hypotheses about the composition and diversity of the microbes living on our skin (microbiota).
PIWIL4 Maintains HIV-1 Latency by Enforcing Epigenetically Suppressive Modifications on the 5′ Long Terminal Repeat
Authors: He Zhangping , Jing Shuliang , Yang Tao , Chen Jingliang , Huang Feng , Zhang Wanying , Peng Zhilin , Liu Bingfeng , Ma Xiancai , Wu Liyang , Pan Ting , Zhang Xu , Li Linghua , Cai Weiping , Tang Xiaoping , Zhang Junsong , Zhang Hui
Published: March 2020

HIV-1 latency is systematically modulated by host factors and viral proteins. During this process, the suppression of HIV-1 transcription plays an essential role in promoting HIV-1 latency. In this study, we found that PIWIL4 repressed HIV-1 promoter activity and maintained HIV-1 latency. In particular, we report that PIWIL4 can regulate gene expression through its association with the suppressive activity of HDAC4. Therefore, we have identified a new function for PIWIL4: it is not only a suppressor of endogenous retrotransposons but also plays an important role in inhibiting transcription and leading to latent infection of HIV-1, a well-known exogenous retrovirus. Our results also indicate a novel therapeutic target to reactivate the HIV-1 latent reservoir.
Ending TB in Southeast Asia: current resources are not enough
Authors: Bhatia Vineet , Srivastava Rahul , Reddy K Srikanth , Sharma Mukta , Mandal Partha Pratim , Chhabra Natasha , Jhalani Shubhi , Mandal Sandip , Arinaminpathy Nimalan , Aditama Tjandra Yoga , Sarkar Swarup
Published: March 2020

The Southeast Asia Region continues to battle tuberculosis (TB) as one of its most severe health and development challenges. Unless there is a substantial increase in investments for TB prevention, diagnosis, care and treatment, there will be catastrophic effects for the region. The uncontrolled TB burden impacts socioeconomic development and increase of drug resistance in the region. Based on epidemiological inputs from a mathematical model, a costing analysis estimates that the desired targets of ending TB are achievable with additional interventions, and critical thresholds require an increase in spending by almost double the current levels. The data source for financial allocation to TB programmes is the report submitted by countries to WHO, while projections are based on modelling. The model accounts for funding needs for all strategies based on published data and accounts for programme and patient costs. This paper delineates the resource needs, availability and gaps of ending TB in the region. It is estimated that close to US$2 billion per year are needed in the region for TB-related activities for a meaningful bending of the incidence curve towards ending TB.
Toward improving respectful maternity care: a discrete choice experiment with rural women in northeast Nigeria
Authors: Umar Nasir , Quaife Matthew , Exley Josephine , Shuaibu Abdulrahman , Hill Zelee , Marchant Tanya
Published: March 2020

Introduction

There is a limited understanding of the importance of respectful maternity care on utilisation of maternal and newborn health services. This study aimed to determine how specific hypothetical facility birth experience of care attributes influenced rural Nigerian women’s stated preferences for hypothetical place of delivery.

Methods

Attributes were identified through a comprehensive review of the literature. These attributes and their respective levels were further investigated in a qualitative study. We then developed and implemented a cross-sectional discrete choice experiment with a random sample of 426 women who had facility-based childbirth to elicit their stated preferences for facility birth experience of care attributes. Women were asked to choose between two hypothetical health facilities or home birth for future delivery. Choice data were analysed using multinomial logit and mixed multinomial logit models.

Results

Complete data for the discrete choice experiment were available for 425 of 426 women. The majority belonged to Fulani ethnic group (60%) and were married (95%). Almost half (45%) had no formal education. Parameter estimates were all of expected signs suggesting internal validity. The most important influence on choice of place of delivery was good health system condition, followed by absence of sexual abuse, then absence of physical and verbal abuse. Poor facility culture, including an unclean birth environment with no privacy and unclear user fee, was associated with the most disutility and had the most negative impact on preferences for facility-based childbirth.

Conclusion

The likelihood of poor facility birth experiences had a significant impact on stated preferences for place of delivery among rural women in northeast Nigeria. The study findings further underline the important relationship between facility birth experience and utilisation. Achieving universal health coverage would require efforts toward addressing poor facility birth experiences and promoting respectful maternity care, to ensure women want to access the services available.