bluuebunny/crossref_metadata_2025 huggingface dataset:
5 Cold stored platelets correct cardiac surgery induced platelet dysfunction
Authors: Scorer Tom , Mumford Andrew
Published: May 2021

Introduction

Platelet dysfunction (thrombocytopathy) is a major problem in the bleeding patient and increases morbidity and healthcare costs. The thrombocytopathy resulting from cardiopulmonary bypass (CPB) can be used to study therapies targeted to improve outcomes in other scenarios, such as trauma. Platelet transfusion is used widely to correct thrombocytopathy. However, the current standard, room temperature stored platelets (RTP) have several disadvantages including; short shelf life, risk of bacterial contamination and deterioration in platelet function during storage. Cold stored platelets (CSP) are a potential alternative product with longer shelf life, reduced contamination risk and better-preserved platelet function.

Methods

Usingex vivomixing studies, we investigated whether CSP were better able to reverse the thrombocytopathy associated with cardiac surgery than RTP. Blood samples were collected from 20 cardiac surgery patients. Donor platelets were split into two bags and stored at either 4°C (CSP), or 22°C (RTP) for up to seven days. The donor platelets were mixed with the patient blood samples to simulate platelet transfusion. The mixed samples were analysed using the TEG 5000 and using a collagen coated flow chamber at arterial shear. Patient samples were analysed alongside healthy controls (n = 20).

Results

After mixing the patient samples with CSP, the TEG R times were shorter than in samples mixed with RTP (p<0.0001), indicating more rapid initiation of clot formation. In the flow chamber experiments, the clot volume was greater in the patient samples mixed with CSP compared with samples mixed with RTP (p<0.0001).

Conclusions

These findings suggest that CSP, but not RTP can partially reverse the thrombocytopathy associated with cardiac surgeryex vivo, at clinically relevant mixing volumes. Reversal of thrombocytopathy by mixing CSP was greatest in the arterial shear model, which may indicate superiorin vivoefficacy that requires confirmation in clinical trials.

* this abstract presentation was awarded First Place.
Effectiveness of school-based interventions in delaying sexual debut among adolescents in sub-Saharan Africa: a protocol for a systematic review and meta-analysis
Authors: Maina Beatrice W , Juma Kenneth , Igonya Emmy Kageha , Osindo Jane , Wao Hesborn , Kabiru Caroline W
Published: May 2021

Introduction

Early sexual debut is associated with poor sexual and reproductive health outcomes across the life course. A majority of interventions aimed at delaying sexual debut among adolescents in sub-Saharan Africa (SSA) have been implemented in schools with mixed findings on the effectiveness of such interventions. This systematic review will summarise and synthesise existing evidence on the effectiveness of school-based interventions in delaying sexual debut among adolescents aged 10–19 years.

Methods and analysis

We will conduct a comprehensive database search of peer-reviewed studies published in PubMed, Scopus, Science Direct, Web of Science, HINARI and EBSCO (PsycINFO, Global Health, CINAHL) and in Cochrane library, National Institute of Health and Turning Research into Practice databases for ongoing studies yet to be published. All studies conducted in SSA between January 2009 and December 2020, regardless of the study design, will be included. Two authors will independently screen all retrieved records and relevant data on sexual debut extracted.

Data will be pooled using the random effects model. Dichotomous outcomes will be reported as risk ratios and continuous data as mean difference at 95% CI. Heterogeneity will be assessed using the I² statistic. Findings will be presented in tables and charts, while providing a description of all included studies, themes and concepts drawn from literature.

Ethics and dissemination

Ethical approval is not required. The findings will be disseminated through peer-reviewed publications, presentations at relevant conferences and other convening focusing on adolescent sexual and reproductive health.
Study protocol for the Healthier Wealthier Families (HWF) pilot randomised controlled trial: testing the feasibility of delivering financial counselling to families with young children who are identified as experiencing financial hardship by community-based nurses
Authors: Price Anna M H , Zhu Anna , Nguyen Huu N J , Contreras-Suárez Diana , Schreurs Natalie , Burley Jade , Lawson Kenny D , Kelaher Margaret , Lingam Raghu , Grace Rebekah , Raman Shanti , Kemp Lynn , Woolfenden Susan , Goldfeld Sharon
Published: May 2021

Introduction

Poverty and deprivation can harm children’s future health, learning, economic productivity and societal participation. The Australian Healthier Wealthier Families project seeks to reduce the childhood inequities caused by poverty and deprivation by creating a systematic referral pathway between two free, community-based services: universal, well-child nursing services, which provide health and development support to families with children from birth to school entry, and financial counselling. By adapting the successful Scottish ‘Healthier Wealthier Children’ model, the objectives of this Australian pilot are to test the (1)feasibilityof systematising the referral pathway, and (2) short-termimpactson household finances, caregiver health, parenting efficacy and financial service use.

Methods and analysis

This pilot randomised controlled trial will run in three sites across two Australian states (Victoria and New South Wales), recruiting a total of 180 participants. Nurses identify eligible caregivers with a 6-item, study-designed screening survey for financial hardship. Caregivers who report one or more risk factors and consent are randomised. The intervention is financial counselling. The comparator is usual care plus information from a government money advice website. Feasibility will be evaluated using the number/proportion of caregivers who complete screening, consent and research measures, and access financial counselling. Though powered to assess feasibility, impacts will be measured 6 months post-enrolment with qualitative interviews and questionnaires about caregiver-reported income, loans and costs (adapted from national surveys, for example, the Household, Income and Labour Dynamics in Australia Survey); health (General Health Questionnaire 1, EuroQol five-dimensional questionnaire, Depression, Anxiety, Stress Scale short-form); efficacy (from the Longitudinal Study of Australian Children); and financial service use (study-designed) compared between arms.

Ethics and dissemination

Ethics committees of the Royal Children’s Hospital (HREC/57372/RCHM-2019) and South West Sydney Local Health District (2019/ETH13455) have approved the study. Participants and stakeholders will receive results through regular communication channels comprising meetings, presentations and publications.

Trial registration number

ACTRN12620000154909; prospectively registered. Pre-results.
Role of parents in fatigue of children with a chronic disease: a cross-sectional study
Authors: Kramer Niels , Nijhof Sanne L , van de Putte Elise M , Ketelaar Marjolijn , Grootenhuis Martha A , van der Ent Kors , Swart Joost F , van Grotel Martine , Dalmeijer Geertje W , Nap-van der Vlist Merel M
Published: May 2021

Objective

As parents majorly impact their child’s well-being, and as fatigue is a highly prevalent threat to the well-being of children with a chronic disease, we aimed to explore the association between parental factors and fatigue in children with a chronic disease.

Design

Cross-sectional study

Setting

Two Dutch children’s hospitals.

Population

Children 2–18 years of age with either an autoimmune disease, cystic fibrosis or post-cancer treatment, and one of their parents.

Main outcome measures

Paediatric fatigue was measured using the PedsQL Multidimensional Fatigue Scale. Parental factors included parental pain, fatigue and physical symptoms, parental distress, catastrophising thoughts about their child’s pain and family empowerment. Multiple linear regressions were used to study associations with paediatric fatigue. A multivariable regression model was used to assess the effect of the different parental factors on paediatric fatigue. All analyses were adjusted for the age and sex of the child.

Results

204 families participated (mean age 11.0±4.3 and 43.5±6.3 years for children and parents, respectively; 69% participation rate). More parental pain, fatigue and physical symptoms, and more parental distress and pain catastrophising were associated with more paediatric fatigue. More parental empowerment was associated with less paediatric fatigue on both subscales. In the multivariable model, only paediatric age remained significantly associated with fatigue. In a separate multivariable model for children 8–18 years old, more parental distress (β=−1.9, 95% CI −3.7 to −0.1) was also significantly associated with more paediatric fatigue.

Conclusions

In a population of children with a chronic disease, parental factors, both physical and psychosocial, were associated with paediatric fatigue. Our study provides evidence that more family empowerment is associated with less paediatric fatigue. This exploratory study adds to our knowledge of associated factors with fatigue in paediatric chronic disease, providing starting points for targeted interventions.
Feasibility of investigating methylphenidate for the treatment of sarcoidosis-associated fatigue (the FaST-MP study): a double-blind, parallel-arm randomised feasibility trial
Authors: Atkins Christopher , Jones Andy , Clark Allan B , Stockl Andrea , Fordham Richard , Wilson Andrew M
Published: May 2021

Introduction

Sarcoidosis-associated fatigue (SAF) is a common clinical problem with limited treatment options. This study was undertaken to determine the feasibility of performing a definitive trial to determine the clinical efficacy methylphenidate in SAF.

Methods

This was a parallel-arm, double-blind, placebo-controlled randomised controlled feasibility trial enrolling sarcoidosis patients reporting significant fatigue. Patients with a Fatigue Assessment Scale score of more than 21 were randomised to receive up to either 10 mg two times per day methylphenidate or identical placebo capsules two times per day, in a dose escalation fashion, for up to 24 weeks. Outcomes included number of participants eligible and willing to participate, withdrawal rates, adherence rates and ability to maintain blinding.

Results

Of 385 patients screened, 56 (14.5%) were eligible and 23 (41% of eligible patients) were randomised. No withdrawals occurred. One participant in the methylphenidate arm discontinued study medications due to chest pain. The side effect profile was not different between the groups. Median medication adherence rates were 98% and 99% in the methylphenidate and placebo arms, respectively. A greater proportion of participants receiving methylphenidate predicted their allocated treatment while blinded compared with those receiving placebo (93.3% vs 57.1%). The investigator could not predict the treatment allocation. Both groups showed clinically meaningful improvements in fatigue from baseline, although no between-group difference was seen.

Conclusions

The data support the feasibility of performing a double-blind parallel trial powered to determine the clinical efficacy of methylphenidate for SAF, however, a multicentre study will be required.

Trial registration number

NCT02643732.
Importance of beta-lactam pharmacokinetics and pharmacodynamics on the recovery of microbial diversity in the airway of persons with cystic fibrosis
Authors: Hahn Andrea , Burrell Aszia , Chaney Hollis , Sami Iman , Koumbourlis Anastassios C , Freishtat Robert J , Zemanick Edith T , Louie Stan , Crandall Keith A
Published: May 2021

Cystic fibrosis (CF) is a chronic lung disease characterized by acute pulmonary exacerbations (PExs) that are frequently treated with antibiotics. The impact of antibiotics on airway microbial diversity remains a critical knowledge gap. We sought to define the association between beta-lactam pharmacokinetic (PK) and pharmacodynamic target attainment on richness and alpha diversity. Twenty-seven children <18 years of age with CF participated in the prospective study. Airway samples were collected at hospital admission for PEx, end of antibiotic treatment (Tr), and >1 month in follow-up (FU). Metagenomic sequencing was performed to determine richness, alpha diversity, and the presence of antibiotic resistance genes. Free plasma beta-lactam levels were measured, and PK modeling was performed to determine time above the minimum inhibitory concentration ( fT>MIC). 52% of study subjects had sufficient fT>MIC for optimal bacterial killing. There were no significant differences in demographics or PEx characteristics, except for F508del homozygosity. No significant differences were noted in richness or alpha diversity at individual time points, and both groups experienced a decrease in richness and alpha diversity at Tr compared with PEx. However, alpha diversity remained decreased at FU compared with PEx in those with sufficient fT>MIC but increased in those with insufficient fT>MIC (Shannon −0.222 vs +0.452, p=0.031, and inverse Simpson −1.376 vs +1.388, p=0.032). Fluoroquinolone resistance was also more frequently detected in those with insufficient fT>MIC (log2 fold change (log2FC) 2.29, p=0.025). These findings suggest sufficient beta-lactam fT>MIC is associated with suppressed recovery of alpha diversity following the antibiotic exposure period.
Self-care practice among hypertensive patients in Ethiopia: systematic review and meta-analysis
Authors: Tadesse Degena Bahrey , Gerensea Hadgu
Published: May 2021

Background

In high-income and low-income countries, including Ethiopia, hypertension (HTN) is a serious public health concern. As a consequence, a massive self-care practice (SCP) is necessary, and the domains of SCP, including adherence to medication, physical activity, weight management, low-salt diet, non-smoking, moderate alcohol usage, and dietary management, are required. However, there is no nationwide study on HTN SCPs in Ethiopia. This meta-analysis, therefore, aimed to estimate the pooled level of HCP among individuals living with HTN in Ethiopia.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline was used to report this systematic review and meta-analysis. We systematically searched the databases PubMed/MEDLINE, Embase, Google Scholar and Science Direct for studies conducted in Ethiopia. All observational studies published until July 2020 were included. Data were analysed using R V.3.5.3 software, and the pooled prevalence with 95% CIs was presented using tables and forest plots. The presence of statistical heterogeneity (I2) within the included studies was evaluated. We used a funnel plot to identify evidence of publication bias. The random-effects meta-analysis model was employed to estimate the pooled proportion of good HTN SCPs.

This was submitted for registration with the International Prospective Register of Systematic Reviews in March 2020 and accepted with the registration number CRD42020175743 (https://www.crd.york.ac.uk/PROSPERO).

Results

Our search databases produced 356 papers. Twelve of these papers fulfilled the inclusion and were found suitable for the review. The total population in this study was 3938. Off these hypertensive populations, 44% (95% CI 34 to 53) had good SCP. The subgroup analysis for each component of SCP was done. The subgroup analysis of good adherence to low-salt diet, alcohol abstinence, medication adherence, non-smoking, physical exercise and weight management was 52% (95% CI 39% to 66%), 77% (95% CI 69% to 88%), 65% (95% CI 45% to 85%), 92% (95% CI 88% to 95%), 43% (95% CI 30% to 56%) and 51% (95% CI 32% to 69%), respectively. In conclusion, nearly half of patients with HTN had good SCPs.
Characterisation of vaping liquids used in vaping devices across four countries: results from an analysis of selected vaping liquids reported by users in the 2016 ITC Four Country Smoking and Vaping Survey
Authors: Fix Brian Vincent , OConnor Richard J , Goniewicz Maciej Lukasz , Leigh Noel L , Cummings Michael , Hitchman Sara C , Fong Geoffrey T , el Nahas Georges , Hammond David , McNeill Ann , Borland Ron , King Bill , Palumbo Mary N
Published: May 2021

Objectives

This study presents an analysis of vaping products (VPs) purchased in the USA, Canada, England and Australia and assesses whether differences in regulations were associated with differences in the chemical composition of the VPs.

Methods

April–September 2017, a total of 234 VP refill liquids and prefilled cartridges were purchased in convenience samples of retail locations in each country. Products were chosen from brands and styles most commonly reported by current VP users in the 2016 ITC Four Country Smoking and Vaping Survey. All products were tested for nicotine, tobacco-specific nitrosamines (TSNAs), minor tobacco alkaloids, organic acids and flavouring chemicals.

Results

Consistent with the laws in Canada and Australia at the time of product purchase, nicotine was not detected in any of the VPs (n=10 in Canada; n=15 in Australia). US liquids (n=54) had a mean nicotine concentration of 16.2 mg/mL, (range=0.0–58.6) and English liquids (n=166) had a mean concentration of 11.9 mg/mL ((range=0.0–31.2) F(3244)=12.32, p<0.001). About 5% of English samples exceeded the UK’s 20 mg/mL nicotine limit. Substantial country differences were observed in levels ofTSNAs, with the USA being higher than elsewhere. Of all products tested, 18.8% contained at least one organic acid. Liquids purchased in England contained far more identifiable flavouring chemicals than those in the other countries.

Conclusions

VP composition, particularly with respect to nicotine and flavouring, varies by country, likely reflecting both marketplace preferences and country-specific regulations. There are differences between nicotine levels claimed on the package and actual levels, particularly in England.
Genome-wide analysis reveals regional patterns of drift, structure, and gene flow in longfin smelt (Spirinchus thaleichthys) in the northeastern Pacific
Authors: Sağlam İsmail K. , Hobbs James , Baxter Randall , Lewis Levi S. , Benjamin Alyssa , Finger Amanda J.
Published: May 2021

The southernmost stock of longfin smelt (Spirinchus thaleichthys) is approaching extirpation in the San Francisco Estuary (SFE); however, patterns of genetic structure, diversity and gene flow which are vital for management are poorly understood in this species. Here, we use genome-wide data to evaluate population structure of longfin smelt across a broad latitudinal scale across estuaries ranging from the SFE to Yakutat Bay and Lake Washington, and fine scale within the Fraser River and the SFE. Results indicate high genetic structure between major estuaries, fine-scale structure within the Fraser River, and low levels of structure within the SFE. Genetic structure was more pronounced between northern estuaries whereas southern estuaries showed shared ancestry and ongoing gene flow, most notably unidirectional northward migration out of the SFE. Furthermore, we detected signatures of local adaptation within the Fraser River and the Skeena River estuaries. Taken together, our results identify broad patterns of genetic diversity in longfin smelt shaped by co-ancestry, unidirectional migration and local adaptation. Results also suggest that the SFE population is genetically distinct from northernmost populations and an important source for maintaining nearby populations.
Mixedwood management positively affects forest health during insect infestations in eastern North America1
Authors: MacLean David A. , Clark Kenneth L.
Published: May 2021

Mixedwood stands are composed of hardwoods and softwoods, with neither comprising greater than 75%–80% of basal area or aboveground biomass. By conferring associational resistance and greater resilience to forests when stressed or disturbed, the more diverse composition of mixedwood stands contributes to forest health. We analyzed three examples where mixedwood stands are more resistant to insect infestations in eastern North America. In balsam fir (Abies balsamea L. Mill.) and spruce (Picea spp.) forests, susceptibility and vulnerability to spruce budworm infestations is reduced with increasing hardwood density. In mid-Atlantic oak-dominated forests, oak mortality following gypsy moth infestations was much greater in oak-dominated forests than in oak–pine mixedwoods, while pine mortality during southern pine beetle infestations was greater in pine-dominated forests than in oak–pine mixedwoods. Overall, mixedwood stands have greater resistance to infestations of defoliators and bark beetles and recover more rapidly from disturbances, reducing economic losses associated with tree mortality and mitigating short-term impacts to ecosystem functioning resulting from insect damage, especially carbon sequestration. Finally, we discuss challenges and opportunities for mixedwood management to minimize insect damage. Management strategies that incorporate mixedwood stands may provide better continuity in supply of forest products and ecosystem services in the face of projected increases in insect infestations associated with changing climate.
Gravitational waves from colliding vacuum bubbles in gauge theories
Authors: Lewicki Marek , Vaskonen Ville
Published: May 2021

We study production of gravitational waves (GWs) in strongly supercooled cosmological phase transitions in gauge theories. We extract from two-bubble lattice simulations the scaling of the GW source, and use it in many-bubble simulations in the thin-wall limit to estimate the resulting GW spectrum. We find that in presence of the gauge field the GW source decays with bubble radius as $$\propto R^{-3}$$

∝

R

-
3

after collisions. This leads to a GW spectrum that follows $$\Omega _{\mathrm{GW}} \propto \omega ^{2.3}$$

Ω
GW

∝

ω

2.3

at low frequencies and $$\Omega _{\mathrm{GW}} \propto \omega ^{-2.9}$$

Ω
GW

∝

ω

-
2.9

at high frequencies, marking a significant deviation from the popular envelope approximation.
Efficiency Loss and Coordination in the Online Shopping Supply Chain with Competitive Shipping Companies
Authors: Hu Yihong , Qiang Qiang
Published: May 2021

This paper studies efficiency loss and coordination mechanism in a supply chain with one online retailer and multiple competitive shipping companies in the presence of congestion effects. We build a three-level game between customers, shipping companies and the retailer. The equilibrium market structure is determined. The optimal volume–investment ratio for each shipping company is the same for both centralized and decentralized supply chains, and it is dependent on the delivery time function, independent of competitors’ decisions. The efficiency loss of the decentralized supply chain with one retailer and one shipping company is found to be 1/4, independent of the delivery time function and the demand function. The loss is reduced when competition is introduced into shipping companies and an upper bound of efficiency loss with multiple homogeneous shipping companies is derived. Revenue-sharing contracts may be designed to allow the decentralized supply chain to perform as well as a centralized one. The necessity of coordination is reduced when competition is introduced and the number of competitive companies increases. Finally, we extend the model to consider heterogeneous shipping companies and find that the disparity between shipping companies increases the efficiency loss because in the decentralized supply chain less efficient shipping companies also provide service. This research explicates the relationship options between e-commerce retailers and shipping companies, providing managerial insights for industry practitioners.
Influence of the proton relay spacer on hydrogen electrocatalysis by cobalt hangman porphyrins
Authors: Roubelakis Manolis M. , Bediako D. Kwabena , Dogutan Dilek K. , Nocera Daniel G.
Published: May 2021

A cobalt hangman porphyrin system with a phenyl spacer between the porphyrin ring and an internal carboxylic acid group as well as its non-hangman analogue were synthesized and utilized for the study of the proton-coupled electron transfer (PCET) kinetics attendant to electrocatalytic hydrogen evolution. Cyclic voltammetry (CV) together with simulations show that a short distance between the proton relay and the redox active cobalt center as well as the increased proton donating strength results in superior catalytic activity. The mechanism of hydrogen generation is at the nexus of proton transfer–electron transfer (PTET) and concerted proton–electron transfer (CPET), as opposed to an ETPT mechanism that is characteristic of hangman systems with longer proton relay networks.
Fabrication of Ag/PDMS Substrate of High-Density Hot Spots and Its Application in in situ Detection
Authors: Wang Chaonan , Xu Meifeng , Xu Tian , Jin Yonglong
Published: May 2021

Through a replacement reaction approach, Ag nanostructure was easily prepared on economical digital video disc (DVD) and polydimethysiloxane (PDMS) with surface structure duplicating from the former. Distinct nanoscale morphology was observed, featuring intersecting Ag nanoplates with abundant hot spots on the DVD and spherical Ag nanoparticles on the PDMS. Surface-enhanced Raman scattering (SERS) spectra, using crystal violet as a probe, revealed a superior enhancement effect in Ag/DVD versus that in Ag/PDMS. Considering the desirable flexibility and transparency of PDMS for in situ detection, we further developed a protocol to introduce intersecting Ag nanoplates onto the PDMS surface. The resulting Ag/PDMS substrate was endowed with remarkable sensitivity, excellent uniformity and good stability under mechanical bending. Furthermore, effective in situ detection of malachite green on fish was demonstrated, highlighting the great potential of our approach for the in situ detection of target molecules on a curved surface.
Effects of Tactile Textures on Preference in Visuo-Tactile Exploration
Authors: Park Wanjoo , Jamil Muhammad Hassan , Gebremedhin Ruth Ghidey , Eid Mohamad
Published: May 2021

The use of haptic technologies has recently become immensely essential in Human-Computer Interaction to improve user experience and performance. With the introduction of tactile feedback on a touchscreen device, commonly known as surface haptics, several applications and interaction paradigms have become a reality. However, the effects of tactile feedback on the preference of 2D images in visuo-tactile exploration task on touchscreen devices remain largely unknown. In this study, we investigated differences of preference score (the tendency of participants to like/dislike a 2D image based on its visual and tactile properties), reach time, interaction time, and response time under four conditions of feedback: no tactile feedback, high-quality of tactile information (sharp tactile texture), low-quality of tactile information (blurred tactile texture), and incorrect tactile information (mismatch tactile texture). The tactile feedback is rendered in the form of roughness that is simulated by modulating the friction between the finger and the surface and is derived from the 2D image. Thirty-six participants completed visuo-tactile exploration tasks for a total of 36 trials (3 2D images × 4 tactile textures × 3 repetitions). Results showed that the presence of tactile feedback enhanced users’ preference (tactile feedback conditions were rated significantly higher than the no tactile feedback condition for preference regardless of the quality/correctness of tactile feedback). This finding is also supported through results from self-reporting where 88.89% of participants preferred to experience the 2D image with tactile feedback. Additionally, the presence of tactile feedback resulted in significantly larger interaction time and response time compared to the no tactile feedback condition. Furthermore, the quality and correctness of tactile information significantly impacted the preference rating (sharp tactile textures were rated statistically higher than blurred tactile and mismatched tactile textures). All of these findings demonstrate that tactile feedback plays a crucial role in users’ preference and thus motivates further the development of surface haptic technologies.
Estimating Distances in Action Space in Augmented Reality
Authors: Gagnon Holly C. , Rosales Carlos Salas , Mileris Ryan , Stefanucci Jeanine K. , Creem-Regehr Sarah H. , Bodenheimer Robert E.
Published: May 2021

Augmented reality
(
AR
) is important for training complex tasks, such as navigation, assembly, and medical procedures. The effectiveness of such training may depend on accurate spatial localization of AR objects in the environment. This article presents two experiments that test egocentric distance perception in augmented reality within and at the boundaries of action space (up to 35 m) in comparison with distance perception in a matched
real-world
(
RW
) environment. Using the Microsoft HoloLens, in Experiment 1, participants in two different RW settings judged egocentric distances (ranging from 10 to 35 m) to an AR avatar or a real person using a visual matching measure. Distances to augmented targets were underestimated compared to real targets in the two indoor, RW contexts. Experiment 2 aimed to generalize the results to an absolute distance measure using verbal reports in one of the indoor environments. Similar to Experiment 1, distances to augmented targets were underestimated compared to real targets. We discuss these findings with respect to the importance of methodologies that directly compare performance in real and mediated environments, as well as the inherent differences present in mediated environments that are “matched” to the real world.
Eye Tracking Interaction on Unmodified Mobile VR Headsets Using the Selfie Camera
Authors: Drakopoulos Panagiotis , Koulieris George-alex , Mania Katerina
Published: May 2021

Input methods for interaction in smartphone-based virtual and mixed reality (VR/MR) are currently based on uncomfortable head tracking controlling a pointer on the screen. User fixations are a fast and natural input method for VR/MR interaction. Previously, eye tracking in mobile VR suffered from low accuracy, long processing time, and the need for hardware add-ons such as anti-reflective lens coating and infrared emitters. We present an innovative mobile VR eye tracking methodology utilizing only the eye images from the front-facing (selfie) camera through the headset’s lens, without any modifications. Our system first enhances the low-contrast, poorly lit eye images by applying a pipeline of customised low-level image enhancements suppressing obtrusive lens reflections. We then propose an iris region-of-interest detection algorithm that is run only once. This increases the iris tracking speed by reducing the iris search space in mobile devices. We iteratively fit a customised geometric model to the iris to refine its coordinates. We display a thin bezel of light at the top edge of the screen for constant illumination. A confidence metric calculates the probability of successful iris detection. Calibration and linear gaze mapping between the estimated iris centroid and physical pixels on the screen results in low latency, real-time iris tracking. A formal study confirmed that our system’s accuracy is similar to eye trackers in commercial VR headsets in the central part of the headset’s field-of-view. In a VR game, gaze-driven user completion time was as fast as with head-tracked interaction, without the need for consecutive head motions. In a VR panorama viewer, users could successfully switch between panoramas using gaze.
The Role of Subsurface Scattering in Glossiness Perception
Authors: Gigilashvili Davit , Shi Weiqi , Wang Zeyu , Pedersen Marius , Hardeberg Jon Yngve , Rushmeier Holly
Published: May 2021

This study investigates the potential impact of subsurface light transport on gloss perception for the purposes of broadening our understanding of visual appearance in computer graphics applications. Gloss is an important attribute for characterizing material appearance. We hypothesize that subsurface scattering of light impacts the glossiness perception. However, gloss has been traditionally studied as a surface-related quality and the findings in the state-of-the-art are usually based on fully opaque materials, although the visual cues of glossiness can be impacted by light transmission as well. To address this gap and to test our hypothesis, we conducted psychophysical experiments and found that subjects are able to tell the difference in terms of gloss between stimuli that differ in subsurface light transport but have identical surface qualities and object shape. This gives us a clear indication that subsurface light transport contributes to a glossy appearance. Furthermore, we conducted additional experiments and found that the contribution of subsurface scattering to gloss varies across different shapes and levels of surface roughness. We argue that future research on gloss should include transparent and translucent media and to extend the perceptual models currently limited to surface scattering to more general ones inclusive of subsurface light transport.
Comprehensive Analysis of the Aging Behavior of Nickel-Rich, Silicon-Graphite Lithium-Ion Cells Subject to Varying Temperature and Charging Profiles
Authors: Schindler Markus , Sturm Johannes , Ludwig Sebastian , Durdel Axel , Jossen Andreas
Published: May 2021

Especially for material combinations incorporating silicon-graphite anodes and nickel-rich cathodes, lifetime and energy density have to be balanced appropriately. In particular, silicon-graphite anodes show increased aging effects due to the extensive volume expansion of silicon and even small variations of its content lead to significant changes in the cell properties because of its large specific capacity. Two batches of the same cell, which differ slightly in their silicon content, were investigated using various charging profiles for a temperature range from 0 °C to 40 °C. The total number of EFC of both cell batches was shown to be strongly dependent on temperature. In addition, cells with reduced silicon content showed EFCs three times higher than their higher silicon counterparts. Contrary to expectations, an extended CV-charging sequence led to an increase in EFC and a decrease in variance. The exclusion of critical voltage ranges shows the most significant influence on both the total of EFC and the variance between the cells. As a result, to increase cell lifetime it is recommended that cells should be preconditioned at low ambient temperatures and extended CV-charging sequences should be considered. If the operational strategy allows the reduction of the upper-voltage-limit, critical voltage areas should be avoided.
From the Editor: Zeros and Crystal Balls
Authors: Rajeshwar Krishnan
Published: May 2021

Well, folks, the much-heralded event, viz. the dawn of the year 2000, is well and truly behind us. While “Y 2 Chaos” and “Millennium Meltdown” did not come to pass after all, this past New Year did seem different somehow — a feeling that is reinforced every time I put down the date somewhere. Does it have to do with all those zeroes, I wonder?
Technology in the Next Century: Reflections on Electrochemistry and Solid-State Science and Technology
Authors: Bruckner-Lea Cindy , Celler George K. , Kelly Robert G. , Lessard Jean , McConnell Robert D. , Niki Katsumi , Rajeshwar Krishnan
Published: May 2021

Prediction is hard, and in the technology world, it can even be a foolhardy exercise. Yet, as we come to the end of the 20th century—a century that saw us reach the moon, split the atom, and crack the genetic code—it is only natural to ask what the 2lst century will hold for us. In doing so, it is also instructive to pause and glance back at what has been accomplished in the last century, perhaps also with a view to learn from the missed opportunities of the past.
GaN Electronics for High Power, High Temperature Applications
Authors: Pearton S. J. , Ren F. , Zhang A. P. , Dang G. , Cao X. A. , Cho H. , Abernathy C. R. , Han J. , Baca A. G. , Monier C. , Chang P. , Shul R J. , Zhang L. , Van Hove J. M. , Chow P. P. , Klaassen J. J. , Polley C. J. , Wowchack A. M. , King D. J. , Chu S. N. G. , Hong M. , Polyakov A. Y. , Smirnov N. B. , Govorkov A. V. , Chyi J.-I. , Lee C.-M. , Nee T.-E. , Chuo C.-C. , Chi G. C.
Published: May 2021

The commercialization of blue, green, and white GaN-based light-emitting diodes and violet laser diodes has created tremendous interest both from an applications viewpoint and for the basic science of the AlGaInN materials system. The fact that extremely efficient light emission can be achieved in heteroepitaxial layers of these materials grown on lattice mismatched substrates such as sapphire is counter to the experience of almost 40 years of semiconductor light source technology.
Hopping Across Interfaces: Heterogeneous Electron Transfer Dynamics
Authors: Forster Robert J.
Published: May 2021

From molecular electronic devices to catalysis and corrosion, the dynamics of heterogeneous electron transfer underpin key scientific and technological advances. Microelectrodes and high performance instrumentation enable the study of heterogeneous electron transfer reactions under unusual conditions and at short timescales. Localized, even atomically resolved, measurements of electron transfer dynamics allow construction of precise maps of surface reactivity.
Atomistic Modeling and Simulation
Authors: Philpott Michael R.
Published: May 2021

Personal computers (PCs) are cheap, and Moore’s law increases are still available in CPU speed (currently 1.3 GHz) and information storage density (about 40 Gb in-2). In short, the combination of price, hardware advance, and user-friendly software has put advanced modeling capabilities firmly in the office and laboratory.
Flexible Organic Photovoltaics with Colorful Semi-Transparent Metal/Dielectric/Metal Top Electrode
Authors: Kim Jae Won , Yuk Dohun , Lee Woojin , Rasool Shafket , Kim Jin Young
Published: May 2021

Organic solar cells (OSCs) have the advantages of a semi-transparent thin film, and of changing colors through controlling optical energy bandgap of organic semiconducting materials. In addition, the flexible OSCs can also be fabricated to be applied in multiple applications such as film-type or foldable solar cells. Here, we have fabricated flexible semi-transparent organic solar cells (STOSCs) with high transparency accompanying highly vivid red, green, and blue colors. To gain high transparency of STOSCs, we employed Fabry-Pérot etalon-type electrodes. An antimony oxide (Sb2O3) cavity layer was introduced between two thin silver layers. By adjusting the thickness of Sb2O3 from 45 nm to 100 nm, vivid colors of red, green, and blue semi-transparent top electrodes were achieved. Besides, selecting well-matched photoactive layers for each color, a less drop of short-circuit current density (Jsc) has been observed. Finally, we obtained high maximum transmittance of 22.52%, 30.10%, and 22.13%, with a power conversion efficiency of 9.16%, 9.85%, and 12.64% for red, green, and blue STOSCs, respectively. Likewise, a power conversion efficiency of 5.75% was achieved with a green-colored large area sub-module.
Undergraduate research programs build skills for diverse students
Authors: Bruthers C. Brooke , Hedman Emma L. , Matyas Marsha Lakes
Published: May 2021

While many professional societies, colleges, and universities offer undergraduate summer research experience (URE) programs for students, few have systematically evaluated their programs for impacts on the fellows. The American Physiological Society (APS) developed and administered multiple UREs with varying target groups: students with and without prior research experiences and students from disadvantaged groups, including underrepresented racial/ethnic minorities (URM), persons with disabilities, first generation college students, and persons with financial or social disadvantages. Each program had specific goals and measurable objectives. To assess the impact of these programs, APS both documented student completion of program tasks (e.g., designing experiments, analyzing data, writing abstracts) and developed reliable and valid survey instruments to quantify students’ self-ratings on a variety of research and career planning skills related to the program objectives. Results indicate that fellows as a whole and for most individual programs gained skills and knowledge in numerous areas: experimental design, data management, lab safety, statistical analysis, data presentation, scientific writing, scientific presentation, professional networking, professional networking at scientific meetings, authorship attribution, animal use in research, human subjects in research, roles of lab mates and mentors, and research career training and planning. Furthermore, there were few differences within the diversity comparison groups (women vs. men, URM fellows vs. non-URM fellows, etc.). Suggestions for improvement of URE programs are proposed.
Postbaccalaureate terminal degree and career choices of students who performed undergraduate research
Authors: Sens Donald A. , Bobylev Mikhail , Cisek Karen L. , Garrett Scott H. , Somji Seema , Sens Mary A. , Doze Van A.
Published: May 2021

This study analyzed terminal degree and career choices of students who performed undergraduate research. In one analysis, the study compared terminal degree and career choices between a course-based undergraduate research experience (CURE) and traditional non-course-based undergraduate research experiences at one primarily undergraduate institution (PUI). Students who pursued postbaccalaureate programs chose terminal degrees at levels exceeding 75%, with no significant difference between a CURE experience and a traditional research experience. Analysis of terminal degree and career choices at four PUIs providing traditional research experiences showed a marked difference in the number of students pursuing terminal degrees. Two PUIs showed rates > 75%, whereas students at the other two PUIs pursued terminal degrees <50% of the time. The majority of students not pursuing terminal degrees chose M.S. degrees in education and healthcare. An analysis was also performed among students participating in traditional summer undergraduate research on a research-intensive university (RIU) campus with a medical school. Students were accepted from two programs, an NIH IDeA Network of Biomedical Research Excellence (INBRE) program recruiting students from the RIU and an NSF Research Experiences for Undergraduates (REU) program recruiting undergraduates from rural PUIs and minority-serving institutions, particularly tribal colleges. Analysis showed that >70% of the students who pursued postbaccalaureate programs chose terminal degrees. INBRE undergraduates displayed a marked preference for the M.D. degree (73.9% vs. 17.4%), whereas the REU students chose the Ph.D. degree (75.0% vs. 22.9%). American Indian students were also analyzed separately for career choice and showed an equal preference for the M.D. and Ph.D. degrees when pursuing postbaccalaureate education. Overall, the results provide evidence that undergraduate student research stimulates student careers in areas needed by the nation’s citizen stakeholders.
Transthyretin amyloid fibrils alter primary fibroblast structure, function, and inflammatory gene expression
Authors: Dittloff Kyle T. , Iezzi Antonio , Zhong Justin X. , Mohindra Priya , Desai Tejal A. , Russell Brenda
Published: May 2021

Transthyretin (TTR) cardiac amyloidosis involves deposition of fibrils of misfolded TTR in the aging human heart, leading to cardiac dysfunction and heart failure. Our novel in vitro studies show that TTR fibrils alter primary cardiac fibroblast cytoskeletal and nuclear structure and focal adhesion formation. Furthermore, both fibrillar and tetrameric TTR significantly increased cellular migration velocity and caused upregulation of inflammatory genes determined by transcriptomic RNA and protein analysis. These findings may suggest new therapeutic approaches.
Direct cardiac versus systemic effects of inorganic nitrite on human left ventricular function
Authors: O’Gallagher Kevin , Cabaco Ana R. , Ryan Matthew , Roomi Ali , Gu Haotian , Dancy Luke , Melikian Narbeh , Chowienczyk Philip J. , Webb Andrew J. , Shah Ajay M.
Published: May 2021

This is the first study to assess the direct and indirect effects of inorganic nitrite on invasive measures of left ventricular function in humans in vivo. Inorganic nitrite has a modest direct myocardial effect, improving diastolic function. Systemic administration of nitrite has larger effects related to alterations in cardiac preload and afterload. The changes induced by nitrite appear favorable for potential use in conditions characterized by LV diastolic dysfunction.
The underlying mechanism of intersite discrepancies in ejection time measurements from arterial waveforms and its validation in the Framingham Heart Study
Authors: Liu Jing , Pahlevan Niema M.
Published: May 2021

Based on a new understanding of pressure wave propagation, we propose a novel dicrotic wave decomposition model considering the dicrotic wave as an independent traveling component. The proposed model can explain the mechanism underlying the intersite discrepancies in ejection time measurement from arterial waveforms and then, in principle, enhance the accuracy of both classical physics-based as well as more contemporary artificial intelligence-based pulse wave analysis methods in clinical and wearable radial blood pressure monitoring applications.
Adipocyte-specific deletion of HuR induces spontaneous cardiac hypertrophy and fibrosis
Authors: Guarnieri Adrienne R. , Anthony Sarah R. , Gozdiff Anamarie , Green Lisa C. , Fleifil Salma M. , Slone Sam , Nieman Michelle L. , Alam Perwez , Benoit Joshua B. , Owens A. Phillip , Kanisicak Onur , Tranter Michael
Published: May 2021

The presence of functional brown adipose tissue in humans is known to be associated with cardiovascular health. Here, we show that adipocyte-specific deletion of the RNA binding protein HuR, which we have previously shown to reduce BAT-mediated thermogenesis, is sufficient to mediate a spontaneous development of cardiac hypertrophy and fibrosis. These results may have implications on the mechanisms by which BAT function and adipose tissue homeostasis directly mediates cardiovascular disease.
Effect of Taro Starch, Beet Juice, Probiotic, and/or Psicose on Gut Microbiota in a Type 2 Diabetic Rat Model: A Pilot Study
Authors: Surono Ingrid S. , Wardana Ata Aditya , Waspodo Priyo , Saksono Budi , Venema Koen
Published: May 2021

Background and Objectives. The gut microbiota has been shown to be involved in the development and severity of type 2 diabetes (T2D). The aim of the present study was to test the effect of potential functional food ingredients, alone or in combination, on the gut microbiota composition in diabetic rats in a pilot study of 1 week of feeding. Methods. In a pilot study to modulate the composition of the gut microbiota, (i) native taro starch, (ii) modified taro starch, (iii) beet juice, (iv) psicose, (v) the probiotic L. plantarum IS-10506, (vi) native starch combined with beet juice, (vii) native starch to which beet juice was adsorbed, (viii) modified starch combined with beet juice, and (ix) modified starch to which beet juice was adsorbed were fed to rats in which T2D was induced with streptozotocin (STZ). After one week, the composition of the gut microbiota was evaluated by sequencing the PCR-amplified V3-V4 region of the 16S rRNA gene. Results and Conclusions. The next-generation sequencing showed that 13 microbial taxa of the gut microbiota were significantly different between groups, depending on the treatment. The results of this pilot study will be used to design a 4-week intervention study in STZ-induced T2D rats to determine the best functional food for counteracting T2D, including their effects on satiety hormones. This should ultimately lead to the development of functional foods for prediabetic and diabetic individuals.