Structured information extraction from scientific text with large language models

Extracting structured knowledge from scientific text remains a challenging task for machine learning models. Here, we present a simple approach to joint named entity recognition and relation extraction and demonstrate how pretrained large language models (GPT-3, Llama-2) can be fine-tuned to extract useful records of complex scientific knowledge. We test three representative tasks in materials chemistry: linking dopants and host materials, cataloging metal-organic frameworks, and general composition/phase/morphology/application information extraction. Records are extracted from single sentences or entire paragraphs, and the output can be returned as simple English sentences or a more structured format such as a list of JSON objects. This approach represents a simple, accessible, and highly flexible route to obtaining large databases of structured specialized scientific knowledge extracted from research papers.

Systematic update to the mammalian relative potency estimate database and development of best estimate toxic equivalency factors for dioxin-like compounds

The World Health Organization (WHO) assesses potential health risks of dioxin-like compounds using Toxic Equivalency Factors (TEFs). This study systematically updated the relative potency (REP) database underlying the 2005 WHO TEFs and applied advanced methods for quantitative integration of study quality and dose-response. Data obtained from fifty-one publications more than doubled the size of the previous REP database (∼1300 datasets). REP quality and relevance for these data was assessed via application of a consensus-based weighting framework. Using Bayesian dose-response modeling, available data were modeled to produce standardized dose/concentration-response Hill curves. Study quality and REP data were synthesized via Bayesian meta-analysis to integrate dose/concentration-response data, author-calculated REPs and benchmark ratios. The output is a prediction of the most likely relationship between each congener and its reference as model-predicted TEF uncertainty distributions, or the 'best estimate TEF' (BE-TEF). The resulting weighted BE-TEFs were similar to the 2005 TEFs, though provide more information to inform selection of TEF values as well as to provide risk assessors and managers with information needed to quantitatively characterize uncertainty around TEF values. Collectively, these efforts produce an updated REP database and an objective, reproducible approach to support development of TEF values based on all available data.

Direct current cardioversion in pregnancy: a multicentre study

OBJECTIVE

Direct current cardioversion (DCCV) in pregnancy is rarely required and typically only documented in single case reports or case series. A recent UK confidential enquiry reported on several maternal deaths where appropriate DCCV appeared to have been withheld.

DESIGN

Retrospective cohort study.

SETTING

Seventeen UK and Ireland specialist maternity centres.

SAMPLE

Twenty-seven pregnant women requiring DCCV in pregnancy.

MAIN OUTCOME MEASURES

Maternal and fetal outcomes following DCCV.

RESULTS

Twenty-seven women had a total of 29 DCCVs in pregnancy. Of these, 19 (70%) initial presentations were to Emergency Departments and eight (30%) to maternity settings. There were no maternal deaths. Seventeen of the women (63%) had a prior history of heart disease. Median gestation at DCCV was 28 weeks, median gestation at delivery was 35 weeks, with a live birth in all cases. The abnormal heart rhythms documented at the first cardioversion were atrial fibrillation in 12/27 (44%) cases, atrial flutter in 8/27 (30%), supraventricular tachycardia in 5/27 (19%) and atrial tachycardia in 2/27 (7%). Fetal monitoring was undertaken following DCCV on 14/29 (48%) occasions (10 of 19 (53%) at ≥26 weeks) and on 2/29 (7%) occasions, urgent delivery was required post DCCV.

CONCLUSIONS

Direct current cardioversion in pregnancy is rarely required but should be undertaken when clinically indicated according to standard algorithms to optimise maternal wellbeing. Once the woman is stable post DCCV, gestation-relevant fetal monitoring should be undertaken. Maternity units should develop multidisciplinary processes to ensure pregnant women receive the same standard of care as their non-pregnant counterparts.

Application of the variational autoencoder to detect the critical points of the anisotropic Ising model

We generalize the previous study on the application of variational autoencoders to the two-dimensional Ising model to a system with anisotropy. Due to the self-duality property of the system, the critical points can be located exactly for the entire range of anisotropic coupling. This presents an excellent test bed for the validity of using a variational autoencoder to characterize an anisotropic classical model. We reproduce the phase diagram for a wide range of anisotropic couplings and temperatures via a variational autoencoder without the explicit construction of an order parameter. Considering that the partition function of (d+1)-dimensional anisotropic models can be mapped to that of the d-dimensional quantum spin models, the present study provides numerical evidence that a variational autoencoder can be applied to analyze quantum systems via the quantum Monte Carlo method.

Quantifying the advantage of domain-specific pre-training on named entity recognition tasks in materials science

A bottleneck in efficiently connecting new materials discoveries to established literature has arisen due to an increase in publications. This problem may be addressed by using named entity recognition (NER) to extract structured summary-level data from unstructured materials science text. We compare the performance of four NER models on three materials science datasets. The four models include a bidirectional long short-term memory (BiLSTM) and three transformer models (BERT, SciBERT, and MatBERT) with increasing degrees of domain-specific materials science pre-training. MatBERT improves over the other two BERT_BASE-based models by 1%∼12%, implying that domain-specific pre-training provides measurable advantages. Despite relative architectural simplicity, the BiLSTM model consistently outperforms BERT, perhaps due to its domain-specific pre-trained word embeddings. Furthermore, MatBERT and SciBERT models outperform the original BERT model to a greater extent in the small data limit. MatBERT’s higher-quality predictions should accelerate the extraction of structured data from materials science literature.

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Efficient extraction of information from materials science literature is needed

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Domain-specific materials science pre-training improves results

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Even simpler domain-specific models can outperform more complex general models

A bottleneck in efficiently connecting new materials discoveries to established literature has arisen due to a massive increase in publications. Four different language models are trained to automatically collect important information from materials science articles. We compare a simple model (BiLSTM) with materials science knowledge to three variants of a more complex model: one with general knowledge (BERT), one with general scientific knowledge (SciBERT), and one with materials science knowledge (MatBERT). We find that MatBERT performs the best overall. This implies that language models with greater extents of materials science knowledge will perform better on materials science-related tasks. The simpler model even consistently outperforms BERT. Furthermore, the performance gaps grow when the models are given fewer examples of information extraction to learn from. MatBERT’s higher-quality results should accelerate the collection of information from materials science literature.

Evidence of horizontal urban heat advection in London using six years of data from a citizen weather station network

Recent advances in citizen weather station (CWS) networks, with data accessible via crowd-sourcing, provide relevant climatic information to urban scientists and decision makers. In particular, CWS can provide long-term measurements of urban heat and valuable information on spatio-temporal heterogeneity related to horizontal heat advection. In this study, we make the first compilation of a quasi-climatologic dataset covering six years (2015-2020) of hourly near-surface air temperature measurements obtained via 1560 suitable CWS in a domain covering south-east England and Greater London. We investigated the spatio-temporal distribution of urban heat and the influences of local environments on climate, captured by CWS through the scope of Local Climate Zones (LCZ)-a land-use land-cover classification specifically designed for urban climate studies. We further calculate, for the first time, the amount of advected heat captured by CWS located in Greater London and the wider south east England region. We find that London is on average warmer by about 1.0 ∘C-1.5 ∘C than the rest of south-east England. Characteristics of the southern coastal climate are also captured in the analysis. We find that on average, urban heat advection (UHA) contributes to 0.22 ± 0.96 ∘C of the total urban heat in Greater London. Certain areas, mostly in the centre of London are deprived of urban heat through advection since heat is transferred more to downwind suburban areas. UHA can positively contribute to urban heat by up to 1.57 ∘C, on average and negatively by down to -1.21 ∘C. Our results also show an important degree of inter- and intra-LCZ variability in UHA, calling for more research in the future. Nevertheless, we already find that UHA can impact green areas and reduce their cooling benefit. Such outcomes show the added value of CWS when considering future urban design.

Influence of state reopening policies in COVID-19 mortality

By the end of May 2020, all states in the US have eased their COVID-19 mitigation measures. Different states adopted markedly different policies and timing for reopening. An important question remains in how the relaxation of mitigation measures is related to the number of casualties. To address this question, we compare the actual data to a hypothetical case in which the mitigation measures are left intact using a projection of the data from before mitigation measures were eased. We find that different states have shown significant differences between the actual number of deaths and the projected figures within the present model. We relate these differences to the states different policies and reopening schedules. Our study provides a gauge for the effectiveness of the approaches by different state governments and can serve as a guide for implementing best policies in the future. According to the Pearson correlation coefficients we obtained, the face mask mandate has the strongest correlation with the death count than any other policies we considered.

Temporal changes in total and metabolically active ruminal methanogens in dairy cows supplemented with 3-nitrooxypropanol

The purpose of this study was to investigate the effect of 3-nitrooxypropanol (3-NOP), a potent methane inhibitor, on total and metabolically active methanogens in the rumen of dairy cows over the course of the day and over a 12-wk period. Rumen contents of 8 ruminally cannulated early-lactation dairy cows were sampled at 2, 6, and 10 h after feeding during wk 4, 8, and 12 of a randomized complete block design experiment in which 3-NOP was fed at 60 mg/kg of feed dry matter. Cows (4 fed the control and 4 fed the 3-NOP diet) were blocked based on their previous lactation milk yield or predicted milk yield. Rumen samples were extracted for microbial DNA (total) and microbial RNA (metabolically active), PCR amplified for the 16S rRNA gene of archaea, sequenced on an Illumina platform, and analyzed for archaea diversity. In addition, the 16S copy number and 3 ruminal methanogenic species were quantified using the real-time quantitative PCR assay. We detected a difference between DNA and RNA (cDNA)-based archaea communities, revealing that ruminal methanogens differ in their metabolic activities. Within DNA and cDNA components, methanogenic communities differed by sampling hour, week, and treatment. Overall, Methanobrevibacter was the dominant genus (94.3%) followed by Methanosphaera, with the latter genus having greater abundance in the cDNA component (14.5%) compared with total populations (5.5%). Methanosphaera was higher at 2 h after feeding, whereas Methanobrevibacter increased at 6 and 10 h in both groups, showing diurnal patterns among individual methanogenic lineages. Methanobrevibacter was reduced at wk 4, whereas Methanosphaera was reduced at wk 8 and 12 in cows supplemented with 3-NOP compared with control cows, suggesting differential responses among methanogens to 3-NOP. A reduction in Methanobrevibacter ruminantium in all 3-NOP samples from wk 8 was confirmed using real-time quantitative PCR. The relative abundance of individual methanogens was driven by a combination of dietary composition, dry matter intake, and hydrogen concentrations in the rumen. This study provides novel information on the effects of 3-NOP on individual methanogenic lineages, but further studies are needed to understand temporal dynamics and to validate the effects of 3-NOP on individual lineages of ruminal methanogens.

The small molecule DIPQUO promotes osteogenic differentiation via inhibition of glycogen synthase kinase 3-beta signaling

Bone fractures are common impact injuries typically resolved through natural processes of osteogenic regeneration and bone remodeling, restoring the biological and mechanical function. However, dysfunctionality in bone healing and repair often arises in the context of aging-related chronic disorders, such as Alzheimer's disease (AD). There is unmet need for effective pharmacological modulators of osteogenic differentiation and an opportunity to probe the complex links between bone biology and cognitive disorders. We previously discovered the small molecule DIPQUO, which promotes osteoblast differentiation and bone mineralization in mouse and human cell culture models, and in zebrafish developmental and regenerative models. Here, we examined the detailed function of this molecule. First, we used kinase profiling, cellular thermal shift assays, and functional studies to identify glycogen synthase kinase 3-beta (GSK3-β) inhibition as a mechanism of DIPQUO action. Treatment of mouse C2C12 myoblasts with DIPQUO promoted alkaline phosphatase expression and activity, which could be enhanced synergistically by treatment with other GSK3-β inhibitors. Suppression of the expression or function of GSK3-β attenuated DIPQUO-dependent osteogenic differentiation. In addition, DIPQUO synergized with GSK3-β inhibitors to stimulate expression of osteoblast genes in human multipotent progenitors. Accordingly, DIPQUO promoted accumulation and activation of β-catenin. Moreover, DIPQUO suppressed activation of tau microtubule-associated protein, an AD-related effector of GSK3-β signaling. Therefore, DIPQUO has potential as both a lead candidate for bone therapeutic development and a pharmacological modulator of GSK3-β signaling in cell culture and animal models of disorders including AD.

COVID-19 testing in outbreak-free care homes: what are the public health benefits?

BACKGROUND

COVID-19 care home outbreaks represent a significant proportion of COVID-19 morbidity and mortality in the UK. National testing initially focused on symptomatic care home residents, before extending to asymptomatic cohorts.

AIM

The aim was to describe the epidemiology and transmission of COVID-19 in outbreak free care homes.

METHODS

A two-point prevalence survey of COVID-19, in 34 Liverpool care homes, was performed in April and May 2020. Changes in prevalence were analysed. Associations between care home characteristics, reported infection, prevention and control interventions, and COVID-19 status were described and analysed.

FINDINGS

No resident developed COVID-19 symptoms during the study. There was no significant difference between: the number of care homes containing at least one test positive resident between the first (17.6%, 95% confidence interval (CI) 6.8-34.5) and second round (14.7%, 95% CI 5.0-31.1) of testing (p>0.99); and the number of residents testing positive between the first (2.1%, 95% CI 1.2-3.4) and second round (1.0%, 95% CI 0.5-2.1) of testing (P=0.11). Care homes providing nursing care (risk ratio (RR) 7.99, 95% CI 1.1-57.3) and employing agency staff (RR 8.4, 95% CI 1.2-60.8) were more likely to contain test positive residents. Closing residents shared space was not associated with residents testing positive (RR 2.63, 95% CI 0.4-18.5).

CONCLUSIONS

Asymptomatic COVID-19 care homes showed no evidence of disease transmission or development of outbreaks; suggesting that current infection prevention and control measures are effective in preventing transmission. Repeat testing at two to three weeks had limited or no public health benefits over regular daily monitoring of staff and residents for symptoms. These results should inform policies calling for regular testing of asymptomatic residents.

Effect of mitigation measures on the spreading of COVID-19 in hard-hit states in the U.S

State government-mandated social distancing measures have helped to slow the growth of the COVID-19 pandemic in the United States. Many of the current predictive models of the development of COVID-19, especially after mitigation efforts, partially rely on extrapolations from data collected in other countries. Since most states enacted stay-at-home orders towards the end of March, the resulting effects of social distancing should be reflected in the death and infection counts by the end of April. Using the data available through April 25th, we investigate the change in the infection rate due to the mitigation efforts and project death and infection counts through September 2020 for some of the most heavily impacted states: New York, New Jersey, Michigan, Massachusetts, Illinois, and Louisiana. We find that with the current mitigation efforts, five of those six states have reduced their base reproduction number to a value less than one, stopping the exponential growth of the pandemic. We also project different scenarios after the mitigation is relaxed.

Multicentre study on pulmonary arterial hypertension therapies in fontan patients: underutilised or of limited use?

Introduction

The Fontan circulation is successful in abolishing cyanosis and chronic volume overload in congenital heart disease (CHD) patients with single ventricle physiology. “Fontan failure” is a major cause of poor quality of life and mortality in these patients. Recently, pulmonary arterial hypertension (PAH) therapies have been used in Fontan patients with variable success, even though patients included in these studies are generally at the best end of the spectrum.

Aim

To assess contemporary patterns of PAH therapy in Fontan patients in large specialist CHD centres.

Methods

We identified all adult patients with a Fontan-type circulation under active follow-up in 8 specialist CHD centres between 2009 and 2019. Patients on PAH therapies were matched by age and gender to untreated patients (1:1 or 1:2). Baseline data were collated immediately prior to initiation of therapy (treated group) or from a synchronous routine clinical assessment (untreated group).

Results

During the study period, 70 Fontan patients were started on PAH therapy (6.5% of those under follow-up). The majority 63 (90.0%) were started on monotherapy with a phosphodiesterase-5 (PDE5) inhibitor, 6 (8.6%) patients were started on an endothelin receptor antagonist (ERA) and 1 (1.4%) received early sequential therapy with a PDE5 inhibitor and ERA. Prostacyclin analogues were not used, and no patients received triple therapy. Overall, 51 (72.9%) patients started therapy electively (49% in outpatient clinic, 51% as day case admission), while 18 (25.7%) were treated following urgent hospital admission with fluid overload +/− acute kidney injury. The remainder (2,2.9%) started therapy following cardiac surgery. Adverse events during treatment were rare. Patients starting PAH therapy were matched to 112 untreated patients (table 1). Patients were well matched between groups for age (p=0.52) and sex (p=0.27). Treated patients were more likely to be significantly impaired than matched patients (56.7% vs. 8.6% in NYHA class III/IV, p<0.0001) and were more likely to have ascites (16.2% vs. 0.9%, p=0.0002). Treated patients were also more likely to have a lower albumin level (43 [14–56] vs. 45 [29–54], p=0.01) or to be on a loop diuretic e.g. furosemide (p<0.0001), at a higher daily dose (p<0.0001) than matched patients. Only a quarter of patients on therapies had no high-risk features (24.2%), 80% of whom were from a single centre.

Conclusion

A small minority of Fontan patients followed in specialist centres receive PAH therapies. PAH therapy was reserved in most centres for patients with more advanced disease, targeting predominantly those with a “failing Fontan” in an individualised approach, in line with the recent adult CHD American Heart Association (AHA) guidelines. Further studied are needed to establish the role of PAH therapies in Fontan patients, provided that adult patients with advanced disease who are at increased risk of adverse outcome are included.

Figure 1

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Dr Constantine received an educational grant from Actelion Pharmaceuticals, a Janssen company of Johnson & Johnson, which helped to pay for travel for data collection.

The single-use rhinolaryngoscope: an evaluation and cost comparison

BACKGROUND

This study investigated whether the single-use rhinolaryngoscope is clinically and economically comparable to the conventional reusable rhinolaryngoscope within a tertiary otolaryngology centre in the UK.

METHODS

A non-blinded, prospective and single-arm evaluation was carried out over a 5-day period, in which micro-costing was used to compare single-use rhinolaryngoscopes with reusable rhinolaryngoscopes.

RESULTS

Overall, 68 per cent of the investigators perceived the single-use rhinolaryngoscope to be 'good' or 'very good', while 85 per cent believed the single-use rhinolaryngoscope could replace the reusable rhinolaryngoscope (n = 59). The incremental costs of reusable rhinolaryngoscope eyepieces and videoscopes in the out-patient clinic, when compared to single-use rhinolaryngoscopes, were £30 and £11, respectively. The incremental costs of reusable rhinolaryngoscope eyepieces and videoscopes in the acute surgical assessment unit, when compared to single-use rhinolaryngoscopes, were -£4 and -£73, respectively.

CONCLUSION

The single-use rhinolaryngoscope provides a clinically comparable, and potentially cost-minimising, alternative to the reusable rhinolaryngoscope for use in the acute surgical assessment unit of our hospital.

A-09 The Relationship Between Subjective Cognitive Complaints, Depression, and Executive Functioning in mTBI Veterans

Objective

Among individuals with mild traumatic brain injury (mTBI), those with depression report greater subjective cognitive complaints than those without depression. In mTBI patients with general cognitive complaints, depression may account for poor performance on objective neuropsychological measures. This study seeks to expand this research by examining depression, subjective executive functioning (EF) complaints, and objective EF performance in Veterans with mTBI.

Method

Fifty-seven Veterans with deployment-related mTBI (12% female; age M = 42.0, SD = 13.6; years education M = 15.0, SD = 1.8) with (n = 29) or without (n = 28) a chart diagnosis of depression. Participants were administered the Behavioral Rating Inventory of Executive Functioning (BRIEF) and objective neuropsychological measures of working memory (i.e., Weschler Adult Intelligence Scale-IV Working Memory Index) and aspects of EF (i.e., Trail Making Test B and Delis-Kaplan Executive Functioning System (D-KEFS) subtests).

Results

Principal component analysis identified similar domains of EF to the BRIEF, including: task monitoring (Trail Making Test B, D-KEFS Letter Fluency, and D-KEFS Tower Test, eigenvalue = 1.93) and shifting (D-KEFS: Color-Word Interference Conditions 3 and 4, and Category Switching, eigenvalue = 1.24). Individuals with depression had greater subjective EF complaints in each BRIEF domain than non-depressed individuals (p’s ≤ .01). However, subjective complaints in these domains were not related to objective performance (r’s = −0.17,-0.19, p’s > .05). Moreover, depressed and non-depressed individuals performed similarly on all EF measures (p’s > .05).

Conclusions

mTBI Veterans with depression report more subjective EF complaints than those without depression. The lack of association between subjective complaints and objective EF performance suggests it is important to treat depression in mTBI patients to remedy perceived cognitive deficits.

Deep learning on the 2-dimensional Ising model to extract the crossover region with a variational autoencoder

The 2-dimensional Ising model on a square lattice is investigated with a variational autoencoder in the non-vanishing field case for the purpose of extracting the crossover region between the ferromagnetic and paramagnetic phases. The encoded latent variable space is found to provide suitable metrics for tracking the order and disorder in the Ising configurations that extends to the extraction of a crossover region in a way that is consistent with expectations. The extracted results achieve an exceptional prediction for the critical point as well as agreement with previously published results on the configurational magnetizations of the model. The performance of this method provides encouragement for the use of machine learning to extract meaningful structural information from complex physical systems where little a priori data is available.

Maternal bacteria to correct abnormal gut microbiota in babies born by C-section

INTRODUCTION

There is evidence that caesarean section (CS) is associated with increased risk of childhood obesity, asthma, and coeliac disease. The gut microbiota of CS-born babies differs to those born vaginally, possibly due to reduced exposure to maternal vaginal bacteria during birth. Vaginal seeding is a currently unproven practice intended to reduce such differences, so that the gut microbiota of CS-born babies is similar to that of babies born vaginally. Our pilot study, which uses oral administration as a novel form of vaginal seeding, will assess the degree of maternal strain transfer and overall efficacy of the procedure for establishing normal gut microbiota development.

METHODS AND ANALYSIS

Protocol for a single-blinded, randomized, placebo-controlled pilot study of a previously untested method of vaginal seeding (oral administration) in 30 CS-born babies. A sample of maternal vaginal bacteria is obtained prior to CS, and mixed with 5 ml sterile water to obtain a supernatant. Healthy babies are randomized at 1:1 to receive active treatment (3 ml supernatant) or placebo (3 ml sterile water). A reference group of 15 non-randomized vaginal-born babies are also being recruited. Babies' stool samples will undergo whole metagenomic shotgun sequencing to identify potential differences in community structure between CS babies receiving active treatment compared to those receiving placebo at age 1 month (primary outcome). Secondary outcomes include differences in overall gut community between CS groups (24 hours, 3 months); similarity of CS-seeded and placebo gut profiles to vaginally-born babies (24 hours, 1 and 3 months); degree of maternal vaginal strain transfer in CS-born babies (24 hours, 1 and 3 months); anthropometry (1 and 3 months) and body composition (3 months).

ETHICS AND DISSEMINATION

Ethics approval by the Northern A Health and Disability Ethics Committee (18/NTA/49). Results will be published in peer-reviewed journals and presented at international conferences.

REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12618000339257).

Initial Experience With Autologous Skin Cell Suspension for Treatment of Deep Partial-Thickness Facial Burns

Facial burns present a challenge in burn care, as hypertrophic scarring and dyspigmentation can interfere with patients’ personal identities, ocular and oral functional outcomes, and have long-term deleterious effects. The purpose of this study is to evaluate our initial experience with non-cultured, autologous skin cell suspension (ASCS) for the treatment of deep partial-thickness (DPT) facial burns. Patients were enrolled at a single burn center during a multicenter, prospective, single-arm, observational study involving the compassionate use of ASCS for the treatment of large total BSA (TBSA) burns. Treatment decisions concerning facial burns were made by the senior author. Facial burns were initially excised and treated with allograft. The timing of ASCS application was influenced by an individual’s clinical status; however, all patients were treated within 30 days of injury. Outcomes included subjective cosmetic parameters and the number of reoperations within 3 months. Five patients (4 males, 1 female) were treated with ASCS for DPT facial burns. Age ranged from 2.1 to 40.7 years (mean 18.2 ± 17.3 years). Average follow-up was 231.2 ± 173.1 days (range 63–424 days). Two patients required reoperation for partial graft loss within 3 months in areas of full-thickness injury. There were no major complications and one superficial hematoma. Healing and cosmetic outcomes were equivalent to, and sometimes substantially better than, outcomes typical of split-thickness autografting. Non-cultured, ASCS was successfully used to treat DPT facial burns containing confluent dermis with remarkable cosmetic outcomes. Treatment of DPT burns with ASCS may be an alternative to current treatments, particularly in patients prone to dyspigmentation, scarring sequelae, and with limited donor sites.

C-24 Longitudinal Trajectories of Working Memory Performance in Typically Aging Older Adults

Objective

Cross-sectional studies have shown age-related differences in working memory (WM), but the trajectory is unclear due to the scarcity of longitudinal studies. Additional research is needed to better characterize the course of age-related changes in WM in older adults. The present study sought to address this gap in the literature by conducting serial assessments of WM in a longitudinally followed cohort of typically aging adults. We hypothesized a significant age × time interaction, such that WM would show pronounced declines with advancing age.

Methods

640 functionally intact participants in an aging cohort (clinical dementia rating = 0; age range 52-99, mean age = 75) completed a computerized WM measure, Running Letter Memory (RLM), every ~15 months for up to 8.5 years (mean follow-up = 1.9 years). Longitudinal changes in RLM scores were analyzed using linear mixed effects models, allowing for random slopes and intercepts. All models were adjusted for sex and education.

Results

RLM performance did not significantly decline over time (b = -.14, p = .43). As hypothesized, there was a significant age × time interaction predicting RLM scores (b = -.08, p = .006). Specifically, RLM performance remained relatively stable (or slightly improved) until around age 75, beyond which increasingly precipitous declines were observed with advancing age.

Conclusion

The present results suggest that WM performance does not evidence declines until the mid-70s in typically aging adults, at which point increasingly steep decline trajectories are observed with advancing age. These findings highlight that cognitive aging does not occur at a constant rate in late life.

Autologous Breast Reconstruction Skin Paddle Designs: Classification and Aesthetic Outcomes

Objective Present study was conducted to identify common mastectomy patterns and autologous skin paddle designs, to identify patient characteristics that influence these patterns, and assess aesthetic outcomes associated with each pattern.

Methods Autologous breast reconstructions over 5 years were reviewed. Mastectomy type and resultant skin paddle were categorized into four mastectomy type/skin paddle design groups based on the amount of native “Skin Spared” after mastectomy and the resultant flap skin paddle designed. Groups were designated as skin-sparing mastectomy 1 (SS1)/large elliptical skin paddle, skin-sparing mastectomy 2 (SS2)/small elliptical skin paddle, skin-sparing mastectomy 3 (SS3)/areola skin paddle, and skin-sparing mastectomy 4 (nipple-sparing mastectomy, SS4)/no skin paddle. Surveys were performed to validate the classification system and critique aesthetic outcomes.

Results A total of 89 autologous breast reconstructions were included. Radiotherapy was used in 45.6% of SS1 patients versus 29.2% in SS2 and 12.5% in SS3/SS4. Mean body mass index (BMI) was 30 in SS1/SS2 and 26 in SS3/SS4 mastectomy types (p = 0.045). Delayed reconstruction was performed in 96.5% SS1 versus 62.5% in SS2 and only 25% of SS3/SS4 (p < 0.0001). Physicians and Non-MD personnel correctly categorized 85.8 and 76.1% of skin paddle designs, respectively. Over 75% of those surveyed rated the reconstruction aesthetic outcome as “good-excellent” regardless of the pattern group.

Conclusions Patients in SS1/SS2 groups had a higher incidence of radiotherapy, delayed reconstruction, and higher BMI compared with the SS3/SS4 groups. The classification system is recognizable and may provide improved patient education and communication between healthcare providers. All mastectomy type/skin paddle designs received high aesthetic ratings.

Maternal and fetal outcomes in pregnancies complicated by the inherited aortopathy Loeys-Dietz syndrome

OBJECTIVE

Pregnancies in women with Loeys-Dietz syndrome (LDS) are rare and are typically documented in case reports only. Early reports suggested high rates of maternal complications during pregnancy and the puerperium, including aortic dissection and uterine rupture, but information on fetal outcomes was very limited.

DESIGN

A retrospective cohort study.

SETTING

Eight specialist UK centres.

SAMPLE

Pregnant women with LDS.

METHODS

Data was collated on cardiac, obstetric, and neonatal outcomes.

MAIN OUTCOME MEASURES

Maternal and perinatal outcomes in pregnancies complicated by LDS.

RESULTS

Twenty pregnancies in 13 women with LDS were identified. There was one miscarriage, one termination of pregnancy, and 18 livebirths. In eight women the diagnosis was known prior to pregnancy but only one woman had preconception counselling. In four women the diagnosis was made during pregnancy through positive genotyping, and the other was diagnosed following delivery. Five women had a family history of aortic dissection. There were no aortic dissections in our cohort during pregnancy or postpartum. Obstetric complications were common, including postpartum haemorrhage (33%) and preterm delivery (50%). In all, 14/18 (78%) of deliveries were by elective caesarean section, at a median gestational age at delivery of 37 weeks. Over half the infants (56%) were admitted to the neonatal unit following delivery.

CONCLUSION

Women with LDS require multidisciplinary specialist management throughout pregnancy. Women should be referred for preconception counselling to make informed decisions around pregnancy risk and outcomes. Early elective preterm delivery needs to be balanced against a high infant admission rate to the neonatal unit.

TWEETABLE ABSTRACT

Pregnancy outcomes in women with Loeys-Dietz syndrome.

Screening for Atrial Fibrillation

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Taxonomy of Individual Variations in Aesthetic Responses to Fractal Patterns

In two experiments, we investigate group and individual preferences in a range of different types of patterns with varying fractal-like scaling characteristics. In Experiment 1, we used 1/f filtered grayscale images as well as their thresholded (black and white) and edges only counterparts. Separate groups of observers viewed different types of images varying in slope of their amplitude spectra. Although with each image type, the groups exhibited the "universal" pattern of preference for intermediate amplitude spectrum slopes, we identified 4 distinct sub-groups in each case. Sub-group 1 exhibited a typical peak preference for intermediate amplitude spectrum slopes ("intermediate"; approx. 50%); sub-group 2 exhibited a linear increase in preference with increasing amplitude spectrum slope ("smooth"; approx. 20%), while sub-group 3 exhibited a linear decrease in preference as a function of the amplitude spectrum slope ("sharp"; approx. 20%). Sub-group 4 revealed no significant preference ("other"; approx. 10%). In Experiment 2, we extended the range of different image types and investigated preferences within the same observers. We replicate the results of our first experiment and show that individual participants exhibit stable patterns of preference across a wide range of image types. In both experiments, Q-mode factor analysis identified two principal factors that were able to explain more than 80% of interindividual variations in preference across all types of images, suggesting a highly similar dimensional structure of interindividual variations in preference for fractal-like scaling characteristics.

Derivation of Candidate Clinical Decision Rules to Identify Infants at Risk for Central Apnea

BACKGROUND AND OBJECTIVES

Central apnea complicates, and may be the presenting complaint in, bronchiolitis. Our objective was to prospectively derive candidate clinical decision rules (CDRs) to identify infants in the emergency department (ED) who are at risk for central apnea.

METHODS

We conducted a prospective observational study over 8 years. The primary outcome was central apnea subsequent to the initial ED visit. Infants were enrolled if they presented with central apnea or bronchiolitis. We excluded infants with obstructive apnea, neonatal jaundice, trauma, or suspected sepsis. We developed 3 candidate CDRs by using 3 techniques: (1) Poisson regression clustered on the individual, (2) classification and regression tree analysis (CART), and (3) a random forest (RF).

RESULTS

We analyzed 990 ED visits for 892 infants. Central apnea subsequently occurred in the hospital in 41 (5%) patients. Parental report of apnea, previous history of apnea, congenital heart disease, birth weight ≤2.5 kg, lower weight, and age ≤6 weeks all identified a group at high risk for subsequent central apnea. All CDRs and RFs were 100% sensitive (95% confidence interval [CI] 91%-100%) and had a negative predictive value of 100% (95% CI 99%-100%) for the subsequent apnea. Specificity ranged from 61% to 65% (95% CI 58%-68%) for CDRs based on Poisson models; 65% to 77% (95% CI 62%-90%) for CART; and 81% to 91% (95% CI 78%-92%) for RF models.

CONCLUSIONS

All candidate CDRs had a negative predictive value of 100% for subsequent central apnea.

Dose-dependent modulation of myogenesis by HGF: implications for c-Met expression and downstream signalling pathways

Hepatocyte growth factor (HGF) regulates satellite cell activation, proliferation, and differentiation. We analyzed the dose-dependent effects of HGF on myogenesis. Murine C2C12 and human donor-derived skeletal muscle myoblasts were treated with 0, 2, or 10 ng/ml HGF followed by assessment of proliferation and differentiation. HGF (2 ng/ml) significantly promoted cell division, but reduced myogenic commitment and fusion. Conversely, 10 ng/ml HGF reduced proliferative capability, but increased differentiation. c-Met expression analysis revealed significantly decreased expression in differentiating cells cultured with 2 ng/ml HGF, but increased expression in proliferating cells with 10 ng/ml HGF. Mitogen-activated protein kinase (MAPKs: ERK, JNK, or p38K) and phosphatidylinositol-3-kinase (PI3K) inhibition abrogated the HGF-stimulated increase in cell number. Interestingly, PI3K and p38 kinase facilitated the negative effect of HGF on proliferation, while ERK inhibition abrogated the HGF-mediated decrease in differentiation. Dose-dependent effects of HGF are mediated by changes in c-Met expression and downstream MAPK and PI3K signalling.

Approaches to describing inter-rater reliability of the overall clinical appearance of febrile infants and toddlers in the emergency department

Objectives. To measure inter-rater agreement of overall clinical appearance of febrile children aged less than 24 months and to compare methods for doing so.

Study Design and Setting. We performed an observational study of inter-rater reliability of the assessment of febrile children in a county hospital emergency department serving a mixed urban and rural population. Two emergency medicine healthcare providers independently evaluated the overall clinical appearance of children less than 24 months of age who had presented for fever. They recorded the initial ‘gestalt’ assessment of whether or not the child was ill appearing or if they were unsure. They then repeated this assessment after examining the child. Each rater was blinded to the other’s assessment. Our primary analysis was graphical. We also calculated Cohen’s κ, Gwet’s agreement coefficient and other measures of agreement and weighted variants of these. We examined the effect of time between exams and patient and provider characteristics on inter-rater agreement.

Results. We analyzed 159 of the 173 patients enrolled. Median age was 9.5 months (lower and upper quartiles 4.9–14.6), 99/159 (62%) were boys and 22/159 (14%) were admitted. Overall 118/159 (74%) and 119/159 (75%) were classified as well appearing on initial ‘gestalt’ impression by both examiners. Summary statistics varied from 0.223 for weighted κ to 0.635 for Gwet’s AC2. Inter rater agreement was affected by the time interval between the evaluations and the age of the child but not by the experience levels of the rater pairs. Classifications of ‘not ill appearing’ were more reliable than others.

Conclusion. The inter-rater reliability of emergency providers’ assessment of overall clinical appearance was adequate when described graphically and by Gwet’s AC. Different summary statistics yield different results for the same dataset.

First Report of Meloidogyne marylandi Infecting Bermudagrass in Oklahoma

Meloidogyne marylandi is a nematode commonly associated with turfgrasses and has been reported to occur in Texas and Arkansas (1,3). In the fall of 2013, a stand of ultradwarf bermudagrass (Cynodon dactylon × C. transvaalensis) plants in a sand-based, research putting green in Stillwater, Oklahoma, exhibited symptoms of decline. Roots of the affected plants had small galls and upon staining of the root system, numerous egg masses were evident. Egg masses were collected, placed in water, and the morphology of 20 hatched, second-stage juveniles were examined. The characteristics of the juveniles were: body length averaged 393.1 ± 19.87 (range: 361 to 425) μm, mean width averaged 16.6 ± 0.7 (15.6 to 17.8) μm, stylet lengths averaged 12.1 ± 0.7 (10.4 to 12.9) μm, dorsal gland orifice from stylet base averaged 2.9 ± 0.4 (2.5 to 3.6) μm, tail lengths averaged 53.7 ± 3.8 (46.2 to 60.4) μm, and the hyaline region of the tails averaged 10.4 ± 1.1 (8.4 to 12.7) μm. Genomic DNA was extracted from six females that were removed from roots. Amplification and sequencing of the mitochondrial DNA region between COII and 16S rRNA genes was performed with primers 1RNAF (5'-TACCTTTGACCAATCACGCT-3') and CO11R (5'-GGTCAATGTTCAGAAATTTGTGG-3') as previously described (2). A PCR product approximately 510 bp in length was obtained and sequenced at the Oklahoma State University Core Facility. Sequences were compared with those in NCBI's nucleotide database using BLAST and had 97% identity with two sequences from M. marylandi (KC473862.1 and KC473863.1) and the next most similar species being M. graminis (JN241898.1) with 83% identity. To our knowledge, this is the first report of the root-knot nematode M. marylandi in Oklahoma. As bermudagrass becomes more commonly used for putting greens in the turfgrass transition zone, M. marylandi may become a more common and damaging pathogen in the region. References: (1) A. A. Elmi et al. Grass For. Sci. 55:166, 2000. (2) M. A. McClure et al. Plant Dis. 96:635, 2012. (3) J. L. Starr et al. Nematrop. 37:43, 2007.

Effects of an exogenous protease on the fermentation and nutritive value of corn silage harvested at different dry matter contents and ensiled for various lengths of time

The objective of this experiment was to evaluate the effects of adding an experimental protease to corn plants harvested at different maturities on silage fermentation and in vitro ruminal starch digestibility (IVSD). Corn plants were harvested at maturities resulting in plants with 31 or 40% dry matter (DM). Plants were chopped, kernel processed, and treated with (1) only a 0.1 M phosphate buffer (pH 5.5, 5% vol/wt of fresh forage), (2) buffer with protease to obtain a final concentration of 20mg of protease/kg of wet forage, and (3) buffer with protease to obtain a final concentration of 2,000 mg of protease/kg of wet forage. Treated forages (about 500 g) were ensiled in nylon-polyethylene pouches and stored between 21 and 23°C for 0, 45, 90, and 150 d. Data were analyzed as a 2 × 3 × 4 factorial arrangement of treatments, with the main effects of harvest DM, dose of protease, days of ensiling, and their interactions. The treatment with the highest dose of protease resulted in more robust fermentations across harvest DM with higher concentrations of lactic and acetic acids compared with untreated silage. Concentrations of soluble protein (% of crude protein) increased with time of ensiling, regardless of DM content at harvest. However, averaged over both harvest DM contents, it increased by 37% for silages treated with the high dose of protease compared with an average 11% increase for untreated silages and silage treated with the low dose of protease, between d 0 and 45. Averaged over both harvest DM contents, the concentration of soluble protein peaked in silages treated with the high dose of protease after 45 d of ensiling, whereas it peaked at d 90 in untreated silages and silage treated with the low dose of protease. Similar changes occurred in the concentration of NH3-N due to length of ensiling and treatment with protease. In fresh forages, the concentration of starch for early- and late-harvested forages was similar, but IVSD was lower in the latter. After 45 d of ensiling, IVSD was highest in both early- and late-harvested silages that were treated with the high level of protease. After 150 d of ensiling, IVSD was similar among silages treated with protease, regardless of DM at harvest. Treating corn plants with a high dose of an experimental protease at harvest accelerated proteolysis during ensiling, resulting in corn silages with levels of IVSD after 45 d of ensiling that were only obtained in untreated corn silages after 150 d of ensiling.