bluuebunny/crossref_metadata_2025 huggingface dataset:
CHOROIDAL NEVUS TRANSFORMATION INTO MELANOMA PER MILLIMETER INCREMENT IN THICKNESS USING MULTIMODAL IMAGING IN 2355 CASES
Authors: Shields Carol L. , Dalvin Lauren A. , Yu Michael D. , Ancona-Lezama David , Di Nicola Maura , Williams Basil K. , Lucio-Alvarez J. Antonio , Ang Su Mae , Maloney Sean M. , Welch R. Joel , Shields Jerry A.
Published: March 2019

Purpose:

To analyze risk of nevus transformation into melanoma per millimeter increment.

Methods:

Retrospective analysis of 3,806 choroidal nevi for transformation into melanoma per incremental millimeter thickness (flat [≤1.0 mm], thin [1.1–2.0 mm], thicker [2.1–3.0 mm], and thickest [>3.0 mm])

Results:

The median nevus thickness was 1.4 mm, and nevi were categorized (flat, thin, thicker, and thickest) in 1,140 (30%), 2052 (54%), 555 (15%), and 59 (<1%), respectively. There were differences in tumor diameter (2.5, 4.8, 7.5, and 9.3 mm; P < 0.01), optical coherence tomography detection of overlying subretinal fluid (<1, 4, 15, and 11%; P < 0.01), overlying retinal edema (<1, 3, 14, and 25%; P < 0.01), overlying drusen (23, 49, 64, and 64%; P < 0.01), overlying retinal pigment epithelial detachment (1, 4, 4, and 9%; P < 0.01), and overlying lipofuscin hyperautofluoresence (<1, 3, 6, and 7%; P < 0.01). Choroidal nevus transformation into melanoma (n = 90/2,355 cases, 3.8%) was found by Kaplan–Meier 7-year estimates (2.2, 6.1, 31.7, and 34.5%; P < 0.0001) and by hazard ratio (HR) compared with nevus ≤1.0 mm (not available, 4.7 [P = 0.01], 35.7 [P < 0.0001], and 52.0 [P < 0.0001]). For all thicknesses, those with growth displayed increase in mean basal diameter of 2.4 mm and thickness of 1.1 mm, optical coherence tomography increase in subretinal fluid (65%), autofluorescence increase in lipofuscin (40%), and ultrasonography increase in hollowness (30%). Multivariable risk factors, recalled by the mnemonic “To Find Small Ocular Melanoma Doing IMaging” (TFSOM-DIM) representing Thickness >2 mm (ultrasonography), Fluid subretinal (optical coherence tomography), Symptom vision loss (Va), Orange pigment (autofluorescence), Melanoma hollow (ultrasonography), and DIaMeter >5 mm, revealed factors per incremental thickness category (compared with flat) including thin (Fluid overlying, HR 6.1; DIaMeter >5 mm, HR 3.3), thicker (Fluid subretinal ≤3 mm from nevus, HR 5.7; Melanoma acoustic hollowness, HR 2.7), and thickest (Orange pigment, HR 9.1).

Conclusion:

Each incremental increase in choroidal nevus thickness demonstrated risk of growth into melanoma with HR (compared with flat) 4.7 for thin, 35.7 for thicker, and 52.0 for thickest. The increase from ≤2.0 mm to >2.0 mm thickness conferred the greatest rise for transformation.
Fibrin Glue–Assisted Closure of Macroperforation in Predescemetic Deep Anterior Lamellar Keratoplasty With a Donor Obtained From Small Incision Lenticule Extraction
Authors: Jacob Soosan , Dhawan Pallavi , Tsatsos Michael , Agarwal Amar , Narasimhan Smita , Kumar Arun
Published: March 2019

Purpose:

To report a case with multiple macroperforations and a double anterior chamber (AC) after predescemetic deep anterior lamellar keratoplasty.

Methods:

A patient was referred after undergoing complicated excision of pseudopterygium that extended onto the cornea. At presentation, an eccentric lamellar patch graft extending over the pupillary axis with a double AC was seen. Surgical intervention showed a predescemetic plane of dissection with 2 macroperforations and iris plugging of the peripheral perforations. Suturing and fibrin glue alone did not seal the macroperforation, and a donor lenticule from small incision lenticule extraction (SMILE) was used to close the larger perforation using fibrin glue. A trephine was then used to mark a larger area of predescemetic dissection that included the original patch graft. A donor corneal graft was sutured after stripping Descemet membrane (DM).

Results:

Postoperatively, the double AC resolved, and vision improved to 0.50 decimal equivalent (20/40) by 3 weeks. At 18-month postoperative follow-up, corrected distance visual acuity (CDVA) was 0.67 (20/30). The donor graft remained clear, and the SMILE lenticule with underlying sutures could be visualized.

Conclusions:

A donor lenticule from SMILE surgery is a useful adjunct to seal macroperforations in deep anterior lamellar keratoplasty because the thin uniform lamellar tissue is easily applied using fibrin glue and gives uniform and good apposition on both host and donor sides. It can be used immediately without further preparation unlike hand-fashioned patch grafts.
Doxycycline Injection for Sclerotherapy of Lower Eyelid Festoons and Malar Edema: Preliminary Results
Authors: Godfrey Kyle J. , Kally Peter , Dunbar Kristen E. , Campbell Ashley A. , Callahan Alison B. , Lo Christopher , Freund Robert , Lisman Richard D.
Published: March 2019

Purpose:

To investigate the safety and efficacy of direct, intralesional doxycycline hyclate injection for improving the appearance of cosmetically significant lower eyelid festoons and malar edema.

Methods:

An Institutional Review Board approved, retrospective review was performed of 15 consecutive patients with malar edema and/or festoons injected with doxycycline hyclate at a concentration of 10 mg/ml. Pre- and postinjection photographs were reviewed and graded on a scale of 0 to 3 (0: no festoon; 1: small festoon; 2: medium festoon; 3: large festoon) by 2 masked physician observers. Patients were excluded from the final analysis if they received an alternate dose concentration, had incomplete photographic records, or did not follow up. Student t test was used for statistical analysis.

Results:

Twenty consecutive treatment areas of 11 patients were included in the analysis. Final follow up ranged from 3 to 104 weeks, with a mean follow up of 22.5 weeks. The average (standard deviation) initial festoon grade of 2.5 (0.58) decreased to 0.9 (0.82) with a p value of <0.001. The average number of injections performed per side was 1.4 (range: 1–2). The mean volume per injection was 0.72 ml (range: 0.15–2.0 ml). Commonly documented subjective complaints were burning sensation with injection, pain, bruising, and erythema. There were no other dermatologic or visual complications following treatment.

Conclusions:

These preliminary results suggest that intralesional injections of doxycycline hyclate at a concentration of 10 mg/ml may be an effective treatment option for cosmetically significant lower eyelid festoons and malar edema. Future prospective studies with increased patient numbers, increasing concentrations, combination therapies with local anesthetic or regional nerve blocks, and longer follow up are needed to validate these results and determine optimal injection technique.
Evaluation of Folate Receptor-Mediated Cervical Dyeing as a Method for Detection of Cervical Lesions
Authors: Zhao Yun , Li Mingzhu , Li Yali , Lv Qiubo , Chen Fei , Li Bin , Zhang Zhenyu , Guo Hongyan , Lu Dan , Wang Fengying , Zhai Jianjun , Feng Limin , Lai Ailuan , Li Hongxia , Yao Chen , Wei Lihui
Published: March 2019

Objectives

The aim of the study was to evaluate the performance of a folate receptor–mediated tumor detection (FRD) assay for detection of cervical high-grade lesions.

Materials and Method

A total of 1504 patients with abnormal cytology and/or positive human papillomavirus (HPV) testing during primary screening from November 2014 to August 2015 were enrolled. The patients were recruited from the Peking University People's Hospital and 12 other hospitals. Folate receptor–mediated tumor detection was applied in all the patients before colposcopy to compare the detection rate, sensitivity, specificity, positive predictive value, negative predictive value, and coincidence rate with HPV and cytology tests according to the pathologic diagnosis.

Results

In the total of 1504 patients, 503 patients were negative for intraepithelial lesion or malignancy, 440 patients were cervical intraepithelial neoplasia (CIN) 1, 254 patients were CIN 2, 257 patients were CIN 3, 46 patients were squamous cell carcinoma, and 4 patients were adenocarcinoma in situ. The sensitivity of FRD was 77.72%, which was less than cytology (80.39%) and HPV testing (95.54%). The specificity of FRD was 60.02%, which was greater than cytology (30.12%) and HPV testing (14.95%). The coincidence rate of FRD to the pathologic diagnosis (66.62%) was also significantly greater than atypical squamous cells of undetermined significance cytology and above (48.87%) and HPV testing (45.01%, p < .0001). The detection rate of FRD for all grades of lesions increased with the severity of lesions.

Conclusions

Folate receptor–mediated tumor detection has a slightly lower sensitivity and a higher specificity than cytology and HPV testing for detection of CIN 2+. Simplicity of FRD requires less professional skill. Folate receptor–mediated tumor detection could be a candidate test for cervical cancer screening especially in low- and middle-income countries. However, FRD still needs more clinical trial data to demonstrate its ability in general screening population.
ECLS for Legionella: All Ages Welcome in the ELSO Registry
Authors: Dorfman Molly V. , Clark Jonna D. , Brogan Thomas V.
Published: March 2019

We describe the use of extracorporeal life support (ECLS) for Legionellosis in the pediatric and adult populations and report complications, morbidity, and mortality by conducting a retrospective review of patients from the Extracorporeal Life Support Organization registry, including two cases at our pediatric institution. A total of 194 patients with ECLS for Legionella pneumophila infection who received ECLS were included in the analysis. Overall survival was 71%. Lower body weight and VA ECLS were associated with lower survival. ECLS complications including central nervous system (CNS) hemorrhage, cardiopulmonary resuscitation, pulmonary infection, and documented infections were rare but more common among nonsurvivors. Mortality in children (64%) was significantly higher than for adults (27%, p = 0.015). Infants fared very poorly with a mortality of 88%. As demonstrated, ECLS can successfully support patients with severe respiratory failure caused by L. pneumophila infection. Consideration should be given to its use in high-risk pediatric patients with severe acute hypoxemic respiratory failure of unclear etiology. ECLS is a beneficial tool for appropriate candidates with rare disease. Pulmonary respite may provide time for diagnosis and lung recuperation.
Correlation Among Antifactor Xa, Activated Partial Thromboplastin Time, and Heparin Dose and Association with Pediatric Extracorporeal Membrane Oxygenation Complications
Authors: McMichael Ali B. V. , Hornik Christoph P. , Hupp Susan R. , Gordon Sharon E. , Ozment Caroline P.
Published: March 2019

Anticoagulation is essential during extracorporeal membrane oxygenation (ECMO) to prevent catastrophic circuit clotting. Several assays exist to monitor unfractionated heparin (UFH), the most commonly used anticoagulant during ECMO, but no single test or combination of tests has consistently been proven to be superior. This retrospective observational study examines the correlation among antifactor Xa level, activated partial thromboplastin time (aPTT), and UFH dose and the association between antifactor Xa level and aPTT with survival and hemorrhagic and thrombotic complications. Sixty-nine consecutive neonatal and pediatric ECMO patients from September 2012 to December 2014 at a single institution were included. Spearman rank correlation was used to compare antifactor Xa level, aPTT, and UFH dose. Significant but poor correlation exists between antifactor Xa level and UFH dose ρ = 0.1 (p < 0.0001) and aPTT and UFH dose ρ = 0.26 (p < 0.0001). Antifactor Xa level and aPTT were weakly correlated to each other ρ = 0.38 (p < 0.0001). In an univariate analysis, there was no difference between survival and antifactor Xa level, aPTT, or UFH dose. Multiple anticoagulation tests may be superior to a single test during ECMO.
The Association of Nurse Practitioner Scope-of-Practice Laws With Emergency Department Use
Authors: McMichael Benjamin J. , Spetz Joanne , Buerhaus Peter I.
Published: March 2019

Background:

Overuse and inappropriate use of emergency departments (EDs) remains an important issue in health policy. After implementation of Medicaid expansion, many states experienced an increase in ED use, but the magnitude varied. Differential access to primary care might explain such variation.

Objective:

To determine whether the increase in ED use among Medicaid enrollees following Medicaid expansion was smaller in states that allowed greater access to primary care providers by permitting nurse practitioners (NPs) to practice without physician oversight.

Research Design:

Examining data on ED use by Medicaid beneficiaries, we estimated random effects models to examine changes in ED visits. Models for 8 different clinical conditions were estimated, with each model including a linear time trend, indicators for Medicaid expansion and for the absence of physician oversight requirements, and an interaction between these 2 indicators.

Results:

States requiring physician oversight of NPs had a 28% increase in ED visits relative to the preexpansion period, while states allowing NP practice without physician oversight had only a 7% increase. The increase in the share of visits covered by Medicaid in no-oversight states was 40% of the size of the increase in oversight states.

Conclusions:

Allowing NPs to practice without physician oversight was associated with a reduction in the magnitude of increase in ED use following Medicaid expansion. States that restrict NP practice should weigh the costs of maintaining these restrictions against the potential benefits of lower ED use. States considering Medicaid expansion should also consider relaxing NP scope-of-practice laws.
Retooling of Paper-based Outcome Measures to Electronic Format
Authors: Hannan Edward L. , Barrett Stacey C. , Samadashvili Zaza , Schmaltz Stephen P.
Published: March 2019

Background:

Risk adjustment is critical in the comparison of quality of care and health care outcomes for providers. Electronic health records (EHRs) have the potential to eliminate the need for costly and time-consuming manual data abstraction of patient outcomes and risk factors necessary for risk adjustment.

Methods:

Leading EHR vendors and hospital focus groups were asked to review risk factors in the New York State (NYS) coronary artery bypass graft (CABG) surgery statistical models for mortality and readmission and assess feasibility of EHR data capture. Risk models based only on registry data elements that can be captured by EHRs (one for easily obtained data and one for data obtained with more difficulty) were developed and compared with the NYS models for different years.

Results:

Only 6 data elements could be extracted from the EHR, and outlier hospitals differed substantially for readmission but not for mortality. At the patient level, measures of fit and predictive ability indicated that the EHR models are inferior to the NYS CABG surgery risk model [eg, c-statistics of 0.76 vs. 0.71 (P<0.001) and 0.76 vs. 0.74 (P=0.009) for mortality in 2010], although the correlation of the predicted probabilities between the NYS and EHR models was high, ranging from 0.96 to 0.98.

Conclusions:

A simplified risk model using EHR data elements could not capture most of the risk factors in the NYS CABG surgery risk models, many outlier hospitals were different for readmissions, and patient-level measures of fit were inferior.
Meeting the Needs of People Who Identify as Lesbian, Gay, Bisexual, Transgender, and Queer in Palliative Care Settings
Authors: Higgins Agnes , Hynes Geralyn
Published: March 2019

The end-of-life needs of people who identify as lesbian, gay, bisexual, transgender, and queer (LGBTQ) are in many ways identical to those of non-LGBTQ people; however, for a variety of reasons, they are at risk of receiving suboptimal care, irrespective of whether they are being cared for at home or in a nursing home, hospital, or hospice. Although research on the needs of LGBTQ people at the end of life is sparse, drawing on what is available this article explores some of their unique concerns that practitioners should consider during their interactions.
Culturally Acceptable Advance Care Planning and Advance Directives for Persons Experiencing Homelessness
Authors: Stone Whitney , Mixer Sandra J. , Mendola Annette
Published: March 2019

Although the process of dying is a universal human experience, it often magnifies individuals’ unique cultural differences. Persons experiencing homelessness (PEHs) have unique barriers, challenges, and wishes for end-of-life care. There is insufficient evidence about how to provide culturally congruent advance care planning (ACP) through advance directive (AD) completion for PEHs. This study addressed this knowledge gap, and its findings serve as the basis for developing additional strategies to promote a satisfying ACP experience for this population when they complete an AD. The purpose of this study was to discover if an AD form recreated for PEHs would positively affect their completion of the AD as well as their overall experience with ACP. Guided by the culture care theory and qualitative ethnonursing methodology, 38 individuals (30 PEHs and 8 student nurses) were interviewed. Data were analyzed using the 4 phases of ethnonursing analysis. The 3 themes abstracted were (1) “it needs to be done,” (2) the presence or absence of trusted family support, and (3) ACP for PEHs is facilitated by an AD workshop. Nursing interventions based on study findings can be used to help promote a dignified, meaningful ACP experience for vulnerable populations.
Biliary Stricture: The Achilles Heel of Pediatric Living Donor Liver Transplantation
Authors: Yoshizumi Tomoharu , Harada Noboru , Mori Masaki
Published: March 2019

Since a 1989 report demonstrating successful living donor liver transplantation (LDLT), living donors have been increasingly used to overcome the disparity between organ supply and demand, especially in the cases of pediatric patients. Although short-term graft outcomes after LDLT have improved significantly because of progress in surgical techniques and immunosuppression, biliary stricture (BS) remains the Achilles heel of pediatric LDLT and is the major cause of significant long-term morbidity. BS results in poor quality of life or even in graft loss after LDLT, with a reported incidence of BS after pediatric LDLT of 10% to 35%. The suggested risk factors for BS after LDLT are hepatic arterial thrombosis, bile duct ischemia, acute cellular rejection, older donor age, and ABO incompatibility. Duct-to-duct biliary reconstruction, which enables an endoscopic approach to be attempted after BS, is the preferred technique for LDLT. Endoscopic approaches are less invasive and more convenient for recipients than surgical and percutaneous interventions. However, the major cause of end-stage liver disease in pediatric recipients is biliary atresia, and hepaticojejunostomy is needed to reconstruct the bile duct because of the lack of recipient bile duct. Endoscopic approaches for BS are usually less favorable in patients with hepaticojejunostomy than in those with duct-to-duct biliary reconstruction. Treatment options for BS after hepaticojejunostomy at many centers thus involve interventional radiology or surgical reintervention. Although endoscopic approaches remain controversial in pediatric recipients, several reports have shown them to be safe and less invasive.
Seizure Prediction Models in the Neonatal Intensive Care Unit
Authors: Sansevere Arnold J. , Kapur Kush , Peters Jurriaan M. , Fernández Ivan Sánchez , Loddenkemper Tobias , Soul Janet S.
Published: March 2019

Purpose:

Conventional video-EEG monitoring is required to diagnose seizures accurately in neonates. This tool is resource-intense and has limited availability in many centers. Seizure prediction models could help allocate resources by improving efficiency in which conventional video-EEG monitoring is used to detect subclinical seizures. The aim of this retrospective study was to create a neonate-specific seizure prediction model using clinical characteristics and EEG background findings.

Methods:

We conducted a 3-year retrospective study of all consecutive neonates who underwent conventional video-EEG monitoring at a tertiary care pediatric hospital. Variables including age, EEG indication, high-risk clinical characteristics, and EEG background informed seizure prediction models based on a multivariable logistic regression model. A Cox proportional hazard regression model was used to construct time to first EEG seizure.

Results:

Prediction models with clinical variables or background EEG features alone versus combined clinical and background EEG features were created from 210 neonates who met inclusion criteria. The combined clinical and EEG model had a higher area under the curve for combined sensitivity and specificity to 83.0% when compared to the clinical model (76.4%) or EEG model (66.2%). The same trend of higher sensitivity of the combined model was found for time to seizure outcome.

Conclusions:

While both clinical and EEG background features were predictive of neonatal seizures, the combination improved overall prediction of seizure occurrence and prediction of time to first seizure as compared with prediction models based solely on clinical or EEG features alone. With prospective validation, this model may improve efficiency of patient-oriented EEG monitoring.
Coscinodiscus wailesii
mutes unsteady sinking in dark conditions
Authors: Du Clos Kevin T. , Karp-Boss Lee , Villareal Tracy A. , Gemmell Brad J.
Published: March 2019

Several species of large, centric diatoms exhibit an unsteady sinking behaviour characterized by order-of-magnitude oscillations in sinking speed that occur over seconds. We show that under nutrient-depleted conditions,
Coscinodiscus wailesii
exhibits significantly stronger unsteady sinking behaviour in the light than in the dark. Results suggest that regulating unsteady sinking in response to irradiance as well as nutrient conditions may help
C. wailesii
balance its requirements for light and nutrients, which are often spatially separated.
Innate colour preferences of a hawkmoth depend on visual context
Authors: Kuenzinger William , Kelber Almut , Weesner Jordan , Travis Jonathan , Raguso Robert A. , Goyret Joaquín
Published: March 2019

Solitary insects that feed on floral nectar must use innate knowledge to find their first flower. While innate preferences for flower colours are often described as fixed, species-specific traits, the nature and persistence of these preferences have been debated, particularly in relation to ontogenetic processes such as learning. Here we present evidence for a strong context-dependence of innate colour preferences in the crepuscular hawkmothManduca sexta. Contrary to expectations, our results show that innate colour biases shift with changes in the visual environment, namely illuminance and background. This finding reveals that innate responses might emerge from a contextual integration of sensory inputs involved in object class recognition rather than from the deterministic matching of such inputs with a fixed internal representation.
Sperm competition accentuates selection on ejaculate attributes
Authors: Vuarin Pauline , Hingrat Yves , Lesobre Loïc , Jalme Michel Saint , Lacroix Frédéric , Sorci Gabriele
Published: March 2019

Ejaculate attributes are important factors driving the probability of fertilizing eggs. When females mate with several males, competition between sperm to fertilize eggs should accentuate selection on ejaculate attributes. We tested this hypothesis in the North African houbara bustard (Chlamydotis undulata undulata) by comparing the strength of selection acting on two ejaculate attributes when sperm from single males or sperm from different males were used for insemination. In agreement with the prediction, we found that selection on ejaculate attributes was stronger when sperm of different males competed for egg fertilization. These findings provide the first direct comparison of the strength of selection acting on ejaculate attributes under competitive and non-competitive fertilizations, confirming that sperm competition is a major selective force driving the evolution of ejaculate characteristics.
Robert Neville Haszeldine. 3 May 1925—13 October 2016
Authors: Munn R. W. , Taylor D. R.
Published: March 2019

Robert Neville Haszeldine was particularly associated with fluorine chemistry. He did outstanding synthetic work on inorganic and organic fluorocarbon derivatives, including fluoroalkyl Grignard and lithium reagents; fluoroalkyl derivatives of mercury, phosphorus, nitrogen and sulphur; fluoroalkyl silicones; fluoro-olefins; and hexafluorobenzene, pentafluoropyridine and their derivatives. He also made major contributions to the study of free-radical addition reactions and developed new routes to carbenes. He discovered a new class of polymers by copolymerizing a nitroso-compound with an olefin or fluoro-olefin to give the –N–O–C–C– repeating unit. His research revealed a mastery of modern ideas on the mechanism of organic and inorganic reactions coupled with outstanding experimental skill and originality. His work yielded over 500 publications, plus more than 150 patents concerning industrial applications of fluorocarbons, and he was awarded several medals. As head of chemistry at the University of Manchester Institute of Science and Technology (UMIST) he developed a world-class fluorine research group and oversaw a new building for the department, which became one of the largest in the UK. Later, as principal of UMIST, he instigated academic developments just before the government severely cut university funding and imposed full-cost fees for overseas students, drastically reducing UMIST's income. His crisis plan for budget cuts proved divisive, and he took early retirement, citing intolerable financial pressures on UMIST. Initially, he continued with consultancy; later, he became deeply involved with his local community, and created a garden that received local and national recognition, including a plant variety named after him.
Ronald Charles David Breslow. 14 March 1931—25 October 2017
Authors: Brown John M.
Published: March 2019

Ronald Breslow was one of the leading organic chemists of his generation. He had received the perfect start in gaining a Harvard doctorate at the age of 24 supervised by the legendary Bob Woodward, followed by a year of postdoctoral work in Cambridge with the equally legendary, but scientifically distinct, Alexander Todd. An academic career of 62 years at Columbia University followed, starting in 1955, and scientific success arose quickly. He was a physical organic chemist, using this discipline as a vehicle for tackling all manner of scientific problems and venturing as needed into biology, physics or medicine. He prepared the simplest aromatic species, solved the mechanism of action of Vitamin B1, built bridges between organic chemistry and enzymology, and developed an anti-cancer drug with a distinct enzyme target. Rewards, honours and prestigious lecture invitations arrived throughout his career, in recognition of the scope and originality of his achievements. He met Esther at Harvard, and they married on completion of his PhD. After returning to the USA, she pursued a successful career in biochemistry at Weill Cornell Medical School in New York. They raised two daughters, Stephanie and Karen, who both became successful attorneys. He had strong family values and was very proud of all their achievements. Towards his co-workers, he was open, eager to engage in discussion and committed to supporting them, both during time at Columbia and thereafter. His warmth encouraged positive responses to his style of supervision, and lively discussions. He was an accomplished classical and jazz pianist, the family cook, and they scuba-dived on annual vacations.
Thinking twice about the evolution of photosynthesis
Authors: Cardona Tanai
Published: March 2019

Sam Granick opened his seminal 1957 paper titled ‘Speculations on the origins and evolution of photosynthesis’ with the assertion that there is a constant urge in human beings to seek beginnings (I concur). This urge has led to an incessant stream of speculative ideas and debates on the evolution of photosynthesis that started in the first half of the twentieth century and shows no signs of abating. Some of these speculative ideas have become commonplace, are taken as fact, but find little support. Here, I review and scrutinize three widely accepted ideas that underpin the current study of the evolution of photosynthesis: first, that the photochemical reaction centres used in anoxygenic photosynthesis are more primitive than those in oxygenic photosynthesis; second, that the probability of acquiring photosynthesis via horizontal gene transfer is greater than the probability of losing photosynthesis; and third, and most important, that the origin of anoxygenic photosynthesis pre-dates the origin of oxygenic photosynthesis. I shall attempt to demonstrate that these three ideas are often grounded in incorrect assumptions built on more assumptions with no experimental or observational support. I hope that this brief review will not only serve as a cautionary tale but also that it will open new avenues of research aimed at disentangling the complex evolution of photosynthesis and its impact on the early history of life and the planet.
A battle for transmission: the cooperative and selfish animal mitochondrial genomes
Authors: Klucnika Anna , Ma Hansong
Published: March 2019

The mitochondrial genome is an evolutionarily persistent and cooperative component of metazoan cells that contributes to energy production and many other cellular processes. Despite sharing the same host as the nuclear genome, the multi-copy mitochondrial DNA (mtDNA) follows very different rules of replication and transmission, which translate into differences in the patterns of selection. On one hand, mtDNA is dependent on the host for its transmission, so selections would favour genomes that boost organismal fitness. On the other hand, genetic heterogeneity within an individual allows different mitochondrial genomes to compete for transmission. This intra-organismal competition could select for the best replicator, which does not necessarily give the fittest organisms, resulting in mito-nuclear conflict. In this review, we discuss the recent advances in our understanding of the mechanisms and opposing forces governing mtDNA transmission and selection in bilaterians, and what the implications of these are for mtDNA evolution and mitochondrial replacement therapy.
The molecular, cellular and pathophysiological roles of iRhom pseudoproteases
Authors: Dulloo Iqbal , Muliyil Sonia , Freeman Matthew
Published: March 2019

iRhom proteins are catalytically inactive relatives of rhomboid intramembrane proteases. There is a rapidly growing body of evidence that these pseudoenzymes have a central function in regulating inflammatory and growth factor signalling and consequent roles in many diseases. iRhom pseudoproteases have evolved new domains from their proteolytic ancestors, which are integral to their modular regulation and functions. Although we cannot yet conclude the full extent of their molecular and cellular mechanisms, there is a clearly emerging theme that they regulate the stability and trafficking of other membrane proteins. In the best understood case, iRhoms act as regulatory cofactors of the ADAM17 protease, controlling its function of shedding cytokines and growth factors. It seems likely that as the involvement of iRhoms in human diseases is increasingly recognized, they will become the focus of pharmaceutical interest, and here we discuss what is known about their molecular mechanisms and relevance in known pathologies.
Human indoor climate preferences approximate specific geographies
Authors: Just Michael G. , Nichols Lauren M. , Dunn Robert R.
Published: March 2019

Human engineering of the outdoors led to the development of the indoor niche, including home construction. However, it is unlikely that domicile construction mechanics are under direct selection for humans. Nonetheless, our preferences within indoor environments are, or once were, consequential to our fitness. The research of human homes does not usually consider human evolution, and, therefore, we are without previous predictions about indoor climate preference. We worked with citizen scientists to collect indoor climate data from homes (
n
= 37) across the USA. We then compared these data to recent global terrestrial climate data (0.5° grid cells,
n
= 67 420) using a climate dissimilarity index. We also compared some climate-related physiological parameters (e.g. thermoneutral zone (TNZ)) between humans and a selection of non-human primates. On average, our study homes were most similar in climate to the outdoor conditions of west central Kenya. We found that the indoor climates of our study homes largely matched the TNZ of humans and other primates. Overall, we identified the geographical distribution of the global outdoor climate that is most similar to the interiors of our study homes and summarized study home indoor climate preferences.
Multiple exposures, reinfection and risk of progression to active tuberculosis
Authors: Ackley Sarah F. , Lee Robyn S. , Worden Lee , Zwick Erin , Porco Travis C. , Behr Marcel A. , Pepperell Caitlin S.
Published: March 2019

A recent study reported on a tuberculosis (TB) outbreak in a largely Inuit village. Among newly infected individuals, exposure to additional active cases was associated with an increasing probability of developing active disease within a year. Using binomial risk models, we evaluated two potential mechanisms by which multiple infections during the first year following initial infection could account for increasing disease risk with increasing exposures. In the
reinfection model
, each infectious contact confers an independent risk of an infection, and infections contribute independently to active disease. In the
threshold model
, disease risk follows a sigmoidal function with small numbers of infectious contacts conferring a low risk of active disease and large numbers of contacts conferring a high risk. To determine the dynamic impact of reinfection during the early phase of infection, we performed simulations from a modified Reed–Frost model of TB dynamics following spread from an initial number of cases. We parametrized this model with the maximum-likelihood estimates from the reinfection and threshold models in addition to the observed distribution of exposures among new infections. We find that both models can plausibly account for the observed increase in disease risk with increasing infectious contacts, but the threshold model confers a better fit than a nested model without a threshold (
p
= 0.04). Our simulations indicate that multiple exposures to infectious individuals during this critical time period can lead to dramatic increases in outbreak size. In order to decrease TB burden in high-prevalence settings, it may be necessary to implement measures aimed at preventing repeated exposures, in addition to preventing primary infection.
Enhancement of an organic–metallic hybrid charring agent on flame retardancy of ethylene-vinyl acetate copolymer
Authors: Xu Bo , Ma Wen , Shao Lushan , Qian Lijun , Qiu Yong
Published: March 2019

An organic triazine charring agent hybrid with zinc oxide (OTCA@ZnO) was prepared and well characterized through Fourier transform infrared spectrometry (FTIR), solid-state nuclear magnetic resonance (SSNMR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The flame retardancy and thermal behaviour of intumescent flame retardant ethylene-vinyl acetate (EVA) composites combining OTCA@ZnO and ammonium polyphosphate (APP) were investigated using limited oxygen index (LOI), UL-94 vertical burning, cone calorimetry and TGA. The structure and morphology of chars were investigated by scanning electron microscopy (SEM), FTIR, laser Raman spectroscopy analysis (LRS) and X-ray photoelectron spectroscopy (XPS). Results revealed that OTCA@ZnO exhibited excellent thermal stability and dispersity after hybridization. The flame retardancy and smoke suppression properties of EVA were significantly improved by introducing APP/OTCA@ZnO. TGA results indicated that APP/OTCA@ZnO presented an excellent synergistic effect and promoted the char formation of EVA composites. Residue analysis results showed more char with high quality connected by richer P–O–C, P–N and P–O–Si structures was formed in APP/OTCA@ZnO system than APP/HOTCA/ZnO system, which consequently suppressed more efficiently the combustion and smoke production due to thein situcatalytic carbonization effect of hybrid.
The three-dimensional flower-like Bi
2
WO
6
assisted by ethanolamine through a microwave method for efficient photocatalytic activity
Authors: Liu Xingchen , Wang SuZhen , Wang Song , Shi Han , Zhang Xiaolong , Zhong Zhicheng
Published: March 2019

The three-dimensional flower-like Bi
2
WO
6
was synthesized through a one-step microwave method (the reaction temperature was 434 K and the reaction took 10 min) with the assistance of ethanolamine (EA). The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, PL, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller analysis. Methyl orange was used as target pollutant to evaluate the photocatalysis property of samples. Furthermore, the influence of the mechanism of EA on the structure and catalytic performance of Bi
2
WO
6
was discussed. The detailed characterizations revealed that the three-dimensional flower-like Bi
2
WO
6
was successfully synthesized with the assistance of EA. The results confirmed that EA significantly influenced the morphology of Bi
2
WO
6
products. The addition of EA can effectively alter the pressure of the reaction and improve the crystal phase and structure of Bi
2
WO
6
photocatalysts, enhancing the photocatalytic activity of samples and improving the photocatalytic efficiency. EA can serve as an assembling agent and structure-directing agent resulting in the formation of flower-like architectures. With the increase of the amount of EA, the as-prepared Bi
2
WO
6
sample gradually forms a flower-like structure, leading to a shorter time of light holes migrating to the surface of the catalyst. It makes the compound rate significantly decreased, and improves the photocatalytic efficiency of the sample.
Fluctuating reproductive rates in Hawaii's humpback whales,
Megaptera novaeangliae
, reflect recent climate anomalies in the North Pacific
Authors: Cartwright R. , Venema A. , Hernandez V. , Wyels C. , Cesere J. , Cesere D.
Published: March 2019

Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales,
Megaptera novaeangliae
, between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother–calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.
Damage shielding mechanisms in hierarchical composites in nature with potential for design of tougher structural materials
Authors: Marthin Otte , Gamstedt E. Kristofer
Published: March 2019

Load-carrying materials in nature, such as wood and bone, consist of relatively simple building blocks assembled into a hierarchical structure, ranging from the molecular scale up to the macroscopic level. This results in composites with a combination of high strength and high toughness, showing very large fracture surfaces indicating energy dissipation by cracking on multiple length scales. Man-made composites instead consist typically of fibres embedded in a uniform matrix, and frequently show brittle failure through the growth of critical clusters of broken fibres. In this paper, a hierarchical structure inspired by wood is presented. It is designed to incapacitate cluster growth, with the aim of retaining high strength. This is done by introducing new structural levels of successively weaker interfaces with the purpose of reducing the stress concentrations if large clusters appear. To test this hypothesis, a probability density field of further damage growth has been calculated for different microstructures and initial crack sizes. The results indicate that the hierarchical structure should maintain its strength by localization of damage, yet rendering large clusters less harmful by weakening the resulting stress concentration to its surroundings, which would lead to an increase in strain to failure. In this context, the potential of using the biomimetic hierarchical structure in design of composite materials is discussed.
Predictive Bayesian selection of multistep Markov chains, applied to the detection of the hot hand and other statistical dependencies in free throws
Authors: Chang Joshua C.
Published: March 2019

Consider the problem of modelling memory effects in discrete-state random walks using higher-order Markov chains. This paper explores cross-validation and information criteria as proxies for a model’s predictive accuracy. Our objective is to select, from data, the number of prior states of recent history upon which a trajectory is statistically dependent. Through simulations, I evaluate these criteria in the case where data are drawn from systems with fixed orders of history, noting trends in the relative performance of the criteria. As a real-world illustrative example of these methods, this manuscript evaluates the problem of detecting statistical dependencies in shot outcomes in free throw shooting. Over three National Basketball Association (NBA) seasons analysed, several players exhibited statistical dependencies in free throw hitting probability of various types—hot handedness, cold handedness and error correction. For the 2013–2014 to 2015–2016 NBA seasons, I detected statistical dependencies in 23% of all player-seasons. Focusing on a single player, in two of these three seasons, LeBron James shot a better percentage after an immediate miss than otherwise. Conditioning on the previous outcome makes for a more-predictive model than treating free throw makes as independent. When extended specifically to LeBron James' 2016–2017 season, a model depending on the previous shot (single-step Markovian) does not clearly beat a model with independent outcomes. An error-correcting variable length model of two parameters, where James shoots a higher percentage after a missed free throw than otherwise, is more predictive than either model.
A modelling approach for the nonlinear dynamics of assembled structures undergoing fretting wear
Authors: Armand J. , Pesaresi L. , Salles L. , Wong C. , Schwingshackl C. W.
Published: March 2019

Assembled structures tend to exhibit nonlinear dynamic behaviour at high excitation levels due to the presence of contact interfaces. The possibility of building predictive models relies on the ability of the modelling strategy to capture the complex nonlinear phenomena occurring at the interface. One of these phenomena, normally neglected, is the fretting wear occurring at the frictional interface. In this paper, a computationally efficient modelling approach which enables considerations of the effect of fretting wear on the nonlinear dynamics is presented. A multi-scale strategy is proposed, in which two different time scales and space scales are used for the contact analysis and dynamic analysis. Thanks to the de-coupling of the contact and dynamic analysis, a more realistic representation of the contact interface, which includes surface roughness, is possible. The proposed approach is applied to a single bolted joint resonator with a simulated rough contact interface. A tendency towards an increase of real contact area and contact stiffness at the interface is clearly observed. The dynamic response of the system is shown to evolve over time, with a slight decrease of damping and an increase of resonance frequency, highlighting the impact of fretting wear on the system dynamics.
Dispersion of waves and transmission–reflection in blood vessels with structured stents
Authors: Frecentese S. , Papathanasiou T. K. , Movchan A. B. , Movchan N. V.
Published: March 2019

A new model is proposed for elastic waves induced by a pulsating flow in a stenotic artery containing several stents. Dispersion properties of the waves depend on the stent structure—this feature is addressed in the present paper. Several vascular stenting procedures include overlapping stents; this configuration is also included in the model. The dispersion and transmission properties are analysed; the analytical derivations are accompanied by illustrative numerical examples.
Unravelling the macro-evolutionary ecology of fish–jellyfish associations: life in the ‘gingerbread house’
Authors: Griffin Donal C. , Harrod Chris , Houghton Jonathan D. R. , Capellini Isabella
Published: March 2019

Fish–jellyfish interactions are important factors contributing to fish stock success. Jellyfish can compete with fish for food resources, or feed on fish eggs and larvae, which works to reduce survivorship and recruitment of fish species. However, jellyfish also provide habitat and space for developing larval and juvenile fish which use their hosts as means of protection from predators and feeding opportunities, helping to reduce fish mortality and increase recruitment. Yet, relatively little is known about the evolutionary dynamics and drivers of such associations which would allow for their more effective incorporation into ecosystem models. Here, we found that jellyfish association is a probable adaptive anti-predator strategy for juvenile fish, more likely to evolve in benthic (fish living on the sea floor), benthopelagic (fish living just above the bottom of the seafloor), and reef-associating species than those adapted to other marine habitats. We also found that jellyfish association likely preceded the evolution of a benthic, benthopelagic, and reef-associating lifestyle rather than its evolutionary consequence, as we originally hypothesized. Considering over two-thirds of the associating fish identified here are of economic importance, and the wide-scale occurrence and diversity of species involved, it is clear the formation of fish–jellyfish associations is an important but complex process in relation to the success of fish stocks globally.