bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue life prediction of magneto-rheological elastomers in magnetic field
Authors: Hosseini Seyyed Mohammad , Shojaeefard Mohammad Hassan , Saeidi Googarchin Hamed
Published: February 2021

Fatigue life is one of the most important characteristics of materials. Predicting fatigue life in magnetorheological elastomer (MRE) under combined and repetitive loads is an unavoidable step to increase the safety coefficient of MREs. In this study, high-temperature vulcanization silicon rubber (HTVSR) based MREs were fabricated by incorporating the different soft carbonyl iron particles (CIP) that samples with 10%, 20%, and 30% of CIP volume were made. Fatigue behavior of MRE under the combination of compression-tension and torsion loading in the presence and absence of magnetic fields was studied by using the multiaxial fatigue testing machine. The relationship between maximum energy density function (W
max) and fatigue life (N) was achieved that it can predict fatigue life in MREs. The results showed that the dissipation energy was smaller in the presence of a magnetic field at the same CIP volume percentage and increased as the CIP volume percentages grew, because the agglomeration in the samples became more. And also with a magnetic field, at the same CIP volume percentages, the strength of the MRE increased that led to the fatigue life of MRE increasing.
Photoelectron spectroscopy reveals molecular diffusion through physisorbed template layers on Au(111)
Authors: Yang Jiacheng , Wang Qi , Wan Shanshan , Wu Di , Chen Mengting , Kashtanov Stepan , Duhm Steffen
Published: February 2021

Molecular exchange processes in organic heterostructures are often detrimental to the performance of nano-optoelectronic devices. Bilayers of vacuum sublimed organic semiconductors on inorganic substrates can serve as reductionist model for organic–organic interfaces and the coupling strength of the template layer on the substrate is a decisive factor for possible molecular exchange. We use density-functional theory modelling and x-ray photoelectron spectroscopy to show that the coupling of the pentacene oxo-derivatives 6,13-pentacenequinone (P2O) and 5,7,12,14-pentacenetetrone (P4O) with Au(111) is weak. Consequently, as shown by ultraviolet photoelectron spectroscopy, subsequently deposited copper-phthalocyanine (CuPc) diffuses through the template layers to the Au(111) substrate.
A theorem of Besicovitch and a generalization of the Birkhoff Ergodic Theorem
Authors: Hagelstein Paul , Herden Daniel , Stokolos Alexander
Published: February 2021

A remarkable theorem of Besicovitch is that an integrable function

f
f

on

R

2

\mathbb {R}^2

is strongly differentiable if its associated strong maximal function

M
S

f

M_S f

is finite a.e. We provide an analogue of Besicovitch’s result in the context of ergodic theory that provides a generalization of Birkhoff’s Ergodic Theorem. In particular, we show that if

f
f

is a measurable function on a standard probability space and

T
T

is an invertible measure-preserving transformation on that space, then the ergodic averages of

f
f

with respect to

T
T

converge a.e. if and only if the associated ergodic maximal function

T
∗

f

T^*f

is finite a.e.
Note on time-regularity for weak solutions to parabolic systems of 𝑝-Laplace type
Authors: Bortz Simon , Egert Moritz , Saari Olli
Published: February 2021

We show that local weak solutions to parabolic systems of

p
p

-Laplace type are Hölder continuous in time with values in a spatial Lebesgue space and Hölder continuous on almost every time line. We provide an elementary and self-contained proof building on the local higher integrability result of Kinnunen and Lewis.
Structure of geometrically non-reduced varieties
Authors: Ji Lena , Waldron Joe
Published: February 2021

We prove a structural result for geometrically non-reduced varieties and give applications to Fano varieties. For example, we show that if

X
X

is the generic fibre of a Mori fibre space of relative dimension

n
n

, and the characteristic is

p
>
2
n
+
1

p>2n+1

, then any geometric non-reducedness of

X
X

comes from the base of some fibration.
Estimating the Marginal Causal Effect and Potential Impact of Waterpipe Smoking on Risk of Multiple Sclerosis Using the Targeted Maximum Likelihood Estimation Method: A Large, Population-Based Incident Case-Control Study
Authors: Abdollahpour Ibrahim , Nedjat Saharnaz , Almasi-Hashiani Amir , Nazemipour Maryam , Mansournia Mohammad Ali , Luque-Fernandez Miguel Angel
Published: February 2021

There are few if any reports regarding the role of lifetime waterpipe smoking in the etiology of multiple sclerosis (MS). In a population-based incident case-control study conducted in Tehran, Iran, we investigated the association between waterpipe smoking and MS, adjusted for confounders. Cases (n = 547) were patients aged 15–50 years identified from the Iranian Multiple Sclerosis Society between 2013 and 2015. Population-based controls (n = 1,057) were persons aged 15–50 years recruited through random digit telephone dialing. A doubly robust estimation method, the targeted maximum likelihood estimator (TMLE), was used to estimate the marginal risk ratio and odds ratio for the association between waterpipe smoking and MS. The estimated risk ratio and odds ratio were both 1.70 (95% confidence interval: 1.34, 2.17). The population attributable fraction was 21.4% (95% confidence interval: 4.0, 38.8). Subject to the limitations of case-control studies in interpreting associations causally, these results suggest that waterpipe use, or strongly related but undetermined factors, increases the risk of MS. Further epidemiologic studies, including nested case-control studies, are needed to confirm these findings.
Health-Care Utilization Due to Suicide Attempts Among Homeless Youth in New York State
Authors: Sakai-Bizmark Rie , Kumamaru Hiraku , Estevez Dennys , Marr Emily H , Haghnazarian Edith , Bedel Lauren E M , Mena Laurie A , Kaplan Mark S
Published: February 2021

Suicide remains the leading cause of death among homeless youth. We assessed differences in health-care utilization between homeless and nonhomeless youth presenting to the emergency department or hospital after a suicide attempt. New York Statewide Inpatient and Emergency Department Databases (2009–2014) were used to identify homeless and nonhomeless youth aged 10–17 who utilized health-care services following a suicide attempt. To evaluate associations with homelessness, we used logistic regression models for use of violent means, intensive care unit utilization, log-transformed linear regression models for hospitalization cost, and negative binomial regression models for length of stay. All models adjusted for individual characteristics with a hospital random effect and year fixed effect. We identified 18,026 suicide attempts with health-care utilization rates of 347.2 (95% confidence interval (CI): 317.5, 377.0) and 67.3 (95% CI: 66.3, 68.3) per 100,000 person-years for homeless and nonhomeless youth, respectively. Length of stay for homeless youth was statistically longer than that for nonhomeless youth (incidence rate ratio = 1.53, 95% CI: 1.32, 1.77). All homeless youth who visited the emergency department after a suicide attempt were subsequently hospitalized. This could suggest a higher acuity upon presentation among homeless youth compared with nonhomeless youth. Interventions tailored to homeless youth should be developed.
Five-Year Safety and Satisfaction With the Lightweight Breast Implant
Authors: Orel Govrin-Yehudain , Noam Calderon , Jacky Govrin-Yehudain
Published: February 2021

Background

The B-Lite lightweight breast implant (LWBI) weighs approximately 30% less than traditional silicone implants while maintaining an equivalent size, form, and function. The LWBI thus places less stress on breast tissues and preserves tissue stability and integrity over time, reducing weight-related complications and reoperation rates.

Objectives

The authors sought to assess the long-term (>5 years) safety and performance of the LWBI in primary and revision augmentation procedures.

Methods

A retrospective, single-center, single surgeon analysis of prospectively collected data was performed on 827 consecutive primary and revision augmentation patients operated between December 2013 and January 2019. A total 1653 implants (250-835 cc, mostly round, textured, extra high-profile) were implanted employing standard surgical techniques. Direct physician-to-patient follow-up ranged from 6 to 67 months. Chart data on reoperations and overall complications as well as patient and surgeon satisfaction were analyzed.

Results

The 5-year per patient Kaplan–Meier reoperation free rate was very high (97.1%). Only 2 of 5 total cases of capsular contracture (CC) grade III required reoperation (Kaplan–Meier rate = 0.2%, CI = 0.1–1.0). No cases of rupture or breast implant-associated anaplastic large cell lymphoma were recorded. A total 94.9% of patients rated the aesthetic outcome, and 95.5% of patients rated the natural look and feel of their breasts at 4 to 5 (satisfied-very satisfied). Similarly, the surgeon rated 4 to 5 on 95.4% of the patients’ aesthetic outcomes.

Conclusions

The favorable safety profile, high patient and surgeon satisfaction, and inherent benefits of reduced weight should make the LWBI a strongly considered strategic alternative to traditional implants.

Level of Evidence: 3
How to Prevent and Treat Complications in Facelift Surgery, Part 1: Short-Term Complications
Authors: Sinclair Nicholas R , Coombs Demetrius M , Kwiecien Grzegorz , Zins James E
Published: February 2021

This article provides a review of available evidence with regard to short-term complications in facelift surgery. The article reviews both the most common complications and less common, but well-described ones. The goal is to offer objective means to minimize postoperative complications and a guide for treatment when they occur.
Social Work Faculty Engagement in Social Policy Practice: A Quantitative Study of the Canadian Experience
Authors: Shewell Hugh , Schwartz Karen , Ongaro Kim
Published: February 2021

This article reports on a quantitative study of how Canadian social work educators engage in social policy practice. The first part of the article contextualises social policy in Canada, explains how social policy has been incorporated into Canadian social work education and concludes by posing the research question. The second part presents the study’s findings of how and to what extent Canadian social work academics engage with social policy including its development, analysis and implementation. Thirty-one educators representing seventeen of Canada’s forty schools of social work responded to a standard questionnaire used in a collection of cross-national studies. The Canadian responses were analysed to determine (1) the level and type of engagement in policy including the perceived impact on social policy and (2) the institutional and individual factors associated with their engagement. Some comparisons are made with other countries studies. The third part of the article provides overall concluding comments linking the first part with the findings of the second, speculates on the reasons for some of the findings and poses some ideas for future research. Finally, it laments the increased focus of Canadian social work on individual pathology.
Dietary conjugated linoleic acid links reduced intestinal inflammation to amelioration of CNS autoimmunity
Authors: Fleck Ann-Katrin , Hucke Stephanie , Teipel Flavio , Eschborn Melanie , Janoschka Claudia , Liebmann Marie , Wami Haleluya , Korn Lisanne , Pickert Geethanjali , Hartwig Marvin , Wirth Timo , Herold Martin , Koch Kathrin , Falk-Paulsen Maren , Dobrindt Ulrich , Kovac Stjepana , Gross Catharina C , Rosenstiel Philip , Trautmann Marcel , Wiendl Heinz , Schuppan Detlef , Kuhlmann Tanja , Klotz Luisa
Published: February 2021

A close interaction between gut immune responses and distant organ-specific autoimmunity including the CNS in multiple sclerosis has been established in recent years. This so-called gut–CNS axis can be shaped by dietary factors, either directly or via indirect modulation of the gut microbiome and its metabolites. Here, we report that dietary supplementation with conjugated linoleic acid, a mixture of linoleic acid isomers, ameliorates CNS autoimmunity in a spontaneous mouse model of multiple sclerosis, accompanied by an attenuation of intestinal barrier dysfunction and inflammation as well as an increase in intestinal myeloid-derived suppressor-like cells. Protective effects of dietary supplementation with conjugated linoleic acid were not abrogated upon microbiota eradication, indicating that the microbiome is dispensable for these conjugated linoleic acid-mediated effects. Instead, we observed a range of direct anti-inflammatory effects of conjugated linoleic acid on murine myeloid cells including an enhanced IL10 production and the capacity to suppress T-cell proliferation. Finally, in a human pilot study in patients with multiple sclerosis (n = 15, under first-line disease-modifying treatment), dietary conjugated linoleic acid-supplementation for 6 months significantly enhanced the anti-inflammatory profiles as well as functional signatures of circulating myeloid cells. Together, our results identify conjugated linoleic acid as a potent modulator of the gut–CNS axis by targeting myeloid cells in the intestine, which in turn control encephalitogenic T-cell responses.
DBS for refractory epilepsy: is closed-loop stimulation of the medial septum the way forward?
Authors: Magloire Vincent , Lignani Gabriele
Published: February 2021

This scientific commentary refers to ‘Closed-loop stimulation of the medial septum terminates epileptic seizures’, by Takeuchi et al. (doi:10.1093/brain/awaa450), and ‘Medial septal GABAergic neurons reduce seizure duration upon optogenetic closed-loop stimulation’, by Hristova et al. (doi:10.1093/brain/awab042).
“Famous, Beloved, Reviled, Respected, Feared, Celebrated:” Media Construction of Greta Thunberg
Authors: Ryalls Emily D , Mazzarella Sharon R
Published: February 2021

In the 16 months before TIME magazine naming Greta Thunberg its Person of the Year, as her influence grew, so too did the news media’s attempts to make sense of her. This project analyzes profiles of Greta Thunberg to understand how journalists constructed the persona that has become “Greta.” We argue the paradoxical framing of Thunberg as exceptional and fierce and childlike contributes to an alternative construction of girlhood grounded in the positive portrayal of her Autism Spectrum Disorder (ASD) diagnosis. While featuring ASD as her “superpower” is potentially progressive, we argue foregrounding Thunberg’s whiteness and age cements her construction as the iconic voice of the climate crisis movement, potentially downplaying the need for collective action to end climate change.
Six-Month Psychophysical Evaluation of Olfactory Dysfunction in Patients with COVID-19
Authors: Boscolo-Rizzo Paolo , Menegaldo Anna , Fabbris Cristoforo , Spinato Giacomo , Borsetto Daniele , Vaira Luigi Angelo , Calvanese Leonardo , Pettorelli Andrea , Sonego Massimo , Frezza Daniele , Bertolin Andy , Cestaro Walter , Rigoli Roberto , D’Alessandro Andrea , Tirelli Giancarlo , Da Mosto Maria Cristina , Menini Anna , Polesel Jerry , Hopkins Claire
Published: February 2021

This study prospectively assessed the 6-month prevalence of self-reported and psychophysically measured olfactory dysfunction in subjects with mild-to-moderate COVID-19. Self-reported smell or taste impairment was prospectively evaluated by SNOT-22 at diagnosis, 4-week, 8-week, and 6-month. At 6 months from the diagnosis, psychophysical evaluation of olfactory function was also performed using the 34-item culturally adapted University of Pennsylvania Smell Identification Test (CA-UPSIT). 145 completed both the 6-month subjective and psychophysical olfactory evaluation. According to CA-UPSIT, 87 subjects (60.0%) exhibited some smell dysfunction, with 10 patients being anosmic (6.9%) and seven being severely microsmic (4.8%). At the time CA-UPSIT was administered, a weak correlation was observed between the self-reported alteration of the sense of smell or taste and olfactory test scores (Spearman’s r = −0.26). Among 112 patients who self-reported normal sense of smell at last follow-up, CA-UPSIT revealed normal smell in 46 (41.1%), mild microsmia in 46 (41.1%), moderate microsmia in 11 (9.8%), severe microsmia in 3 (2.3%), and anosmia in 6 (5.4%) patients; however, of those patients self-reporting normal smell but who were found to have hypofunction on testing, 62 out of 66 had a self-reported reduction in sense of smell or taste at an earlier time point. Despite most patients report a subjectively normal sense of smell, we observed a high percentage of persistent smell dysfunction at 6 months from the diagnosis of syndrome coronavirus 2 (SARS-CoV-2) infection, with 11.7% of patients being anosmic or severely microsmic. These data highlight a significant long-term rate of smell alteration in patients with previous SARS-COV-2 infection.
Persistence With Biologic Therapy and Associated Costs of Patients With Inflammatory Bowel Disease: A German Retrospective Claims Data Analysis
Authors: Mahlich Joerg , May Melanie , Feig Chiara , Straub Vincent , Schmelz Renate
Published: February 2021

Background

In recent years, biologic agents became a relevant and promising treatment option for inflammatory bowel diseases (IBDs). However, high treatment costs and moderate remission rates lead to a high interest in treatment persistence and corresponding economic consequences.

Methods

A retrospective health claims data analysis was conducted including biologic naive patients diagnosed with IBD between 2013 and 2018. Observation points were at 12 and 18 months of follow-up, starting from the first biologic prescription. Nonpersistence was defined as either no further prescription or prescription of another biologic agent within the days of supply per original prescription. Biologic agents included were Adalimumab, Golimumab, Infliximab, Ustekinumab, and Vedolizumab.

Results

In total, 1444 patients with IBD were included in this analysis, mostly treated with Adalimumab (46.9%) and Infliximab (39.9%) as their first biologic treatment. After 12 months, 72.2% of patients were still persistent with their initial biologic treatment with the highest shares for Infliximab (74%) and Vedolizumab (72.4%). 27.8% of patients were nonpersistent, mostly due to a switch of biologic agent (75.8%). Cox regression identified female, hospitalizations, and simultaneous prescriptions of corticosteroids and immunomodulators as risk factors for nonpersistence. Treatment costs per year were approximately 3000€ higher for nonpersistent patients (27,146€) than for persistent patients (23,839€), mostly due to inpatient treatment costs.

Conclusions

The persistence of biologic therapy in this study was rather high at 72% after 12 months, while nonpersistence was mostly due to switches to other biologic agents. Lack of persistence is associated with increased cost, mostly due to nonbiologic medication and inpatient treatment.
Left ventricular remodelling in masters athletes
Authors: Papatheodorou E , Merghani A , Bakalakos A , Hughes R , Torlasco C , Downs E , D"silva A , Finocchiaro G , Malhotra A , Tome M , Moon JC , Al Fakih K , Papadakis M , Sharma S
Published: February 2021

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): I have received a research fellowship grant from the UK based charity Cardiac Risk in the Young

Objectives

We investigated the effect of long-term exercise and sex on left ventricular (LV) geometry in a large group of female and male masters athletes.

Background

Studies assessing LV geometry in masters athletes are scarce.

Methods

Different types of LV geometry were identified according to echocardiography-derived relative wall thickness (RWT) and left ventricular mass (LVM) values as per international guidelines. 4 groups were formed: normal (normal LVM/normal RWT), concentric hypertrophy (increased LVM/increased RWT), eccentric hypertrophy (increased LVM/normal RWT), and concentric remodeling (normal LVM/increased RWT).

Results

A total of 277 healthy, elite, caucasian endurance masters athletes (65% female; mean age54.8 ± 7.7 years) were assessed. The athletes were exercising for a mean 32 ± 11.7 years and have completed a median 70 competitions including a median 13 marathon-type competitions. Females exhibited lower absolute LVM (127.7 ± 30.31g vs 196.57 ± 45.0g, p < 0.001), indexed LVM (76.8 ± 18.0 g/m2 vs. 103.6 ± 22.7 g/m2; p < 0.001), RWT (0.36 ± 0.07 vs. 0.42 ± 0.08; p < 0.001) and absolute LV end-diastolic dimension (LVEDD) (46.3 ± 4.1 mm vs 50.1 ± 5.11 mm, p < 0.001) but greater indexed LVEDD (27.7 ± 2.7mm/m2 vs 26.5 ± 2.7 mm/m2, p < 0.001) compared with male athletes. Most female athletes showed normal LV geometry (72% vs 38% in male athletes, P < 0.001) and significantly less concentric remodeling (12% vs 35%, p < 0.001) and concentric hypertrophy (5% vs 13%, p = 0.01) (table & figure).

Conclusions

A sex-specific response to chronic exercise is observed. Male masters athletes exhibit significantly more frequently abnormal LV geometry with concentric LV remodeling and/or concentric hypertrophy.

Cohort characteristics Male masters athletes N = 97 Female masters athletes N = 180 P value Age (years) 55.0 ± 9.0 54.7 ± 6.9 0.68 Years of exercise 32.0 ± 12.8 33.3 ± 11.1 0.14 LV Mass (g) 127.7 ± 30.31 196.57 ± 45.0 <0.001 LV Mass Indexed (g/m2) 76.8 ± 18.0 103.6 ± 22.7 <0.001 LVEDD (mm) 46.3 ± 4.1 50.1 ± 5.11 <0.001 LVEDD Indexed (mm/m2) 27.7 ± 2.7 26.5 ± 2.7 <0.001 Normal Remodeling 36 (37) 130 (72) <0.001 Eccentric Hypertrophy 14 (14) 18 (10) 0.27 Concentric Remodeling 34 (35) 23 (13) <0.001 Concentric Hypertrophy 13 (13) 9 (5) 0.01 LV Left Ventricular, LVEDD: Left Ventricular End Diastolic Dimension Abstract Figure. Patterns of left ventricular remodeling
The evaluation of myocardial performance index in patients with COVID-19: An echocardiographic follow-up study
Authors: Kaya H , Asoglu R , Afsin A , Tibilli H , Kurt E , Kafadar S , Gulacti U , Kafadar H
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

The epidemic of pneumonia caused by a new coronavirus rapidly spread all over the world. World Health Organization called the condition as coronavirus disease 2019 (COVID-19). COVID-19 has become a life-threatening public health emergency internationally. COVID-19 mostly presents by respiratory tract symptoms including fever, dry cough, and dyspnea. The disease progression causes pneumonia and acute respiratory distress syndrome. Pathophisyology of cardiovascular effects of COVID-19 have not been well known yet. Myocardial dysfunction may occur in cytokine-originated immune reactions. Myocardial performance index (MPI) is a feasible parameter that reflects systolic and diastolic cardiac functions.

Purpose

We aimed to evaluate the MPI in patients with COVID-19.

Methods

The study consisted of 40 patients diagnosed with COVID-19 who had mild pneumonia and had not needed intensive care treatment. Transthoracic echocardiographic examination was performed in all patients at the acute stage of infection and after clinical recovery. The average time interval between the baseline and recovery echocardiography exam was about 28 ± 3,4 days. Blood samples were studied on day 0 and on days 7, 14, 21, and 28.  Immunofluorescence assay was used for COVID-19 antibody titers.  Respiratory secretions were sent for RT-PCR tests.

Results

The mean age was 54 ± 11 years ( male 26 (65% ) ). Statistically significant higher MPI (0.56 ± 0.09 versus 0.44 ± 0.07, p < 0.001), longer isovolumic relaxation time (112.3 ± 13.4 versus 91.8 ± 12.1ms, p < 0.001), longer deceleration time (182.1 ± 30.6 versus 161.5 ± 43.5ms, p = 0.003), shorter ejection time (279.6 ± 20.3 versus 298.8 ± 36.8ms, p < 0.001) and higher E/A ratio (1.53 ± 0.7 versus  1.22 ± 0.4, p < 0.001), were observed during acute period of  infection compared to ones after clinical recovery. Compared with basal values, no significant change in left ventricular systolic ejection fraction was observed after clinical recovery (60.3± 3.2% versus 61.7 ± 2.4%, p > 0.05). Isovolumic contraction time was similar at acute infection and after clinical recovery ( 44.3 ± 7.8 versus 40.6 ± 9.7ms, p > 0.05)

Conclusion

In conclusion, our study suggests global reversible LV dysfunction in COVID-19 patients with preserved LV systolic function based on tissue Doppler derived MPI. This could be due to isolated subclinical diastolic dysfunction. To our knowledge, this study is the first echocardiographic follow-up study that evaluated the systolic and diastolic function of the left ventricle in COVID -19 patients. The underlying mechanism and its clinical significance can be established by further studies.
Temporal changes of left atrial function after orthotopic heart transplantation using cardiac magnetic resonance imaging in a single-center prospective study
Authors: Dohy Z , Szabo L , Czimbalmos C , Szakal-Toth Z , Parazs N , Tarjanyi Z , Kiraly A , Suhai FI , Teszak T , Sax B , Merkely B , Vago H
Published: February 2021

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ÚNKP-19-3-I New National Excellence Program of the Ministry for Innovation and Technology; National Research, Development and Innovation Office of Hungary (NKFIA; NVKP_16-1-2016-0017 National Heart Program)

Background

The geometry and function of the left atrium (LA) change after orthotopic heart transplantation (HTX) with bicaval technique, as the LA has a recipient part around the pulmonary veins and a donor part, and these often contract separately. Because of this altered LA function, the recognition of left ventricular diastolic dysfunction can be challenging. The standard echocardiographic diastolic parameters are often in abnormal range in HTX patients despite of normal left ventricular diastolic function.

Purpose

The aim of our prospective study was to investigate the LA volumes and function and their temporal changes after HTX  using cardiac magnetic resonance (CMR).

Method

To better understand the cardiac characteristics of HTX patients, we started a prospective trial in January 2018. CMR was performed at one, three and six months after HTX. Left atrial contour detection was performed in 2- and 4-chamber views. Patients who had ≥Grade II allograft rejection before the CMR examination, were excluded (n = 6). In the remaining HTX patients (n = 37, 52 ± 12y, 29 male) and in a control group (n = 20, 49 ± 5y, 15 male) LA ejection fraction (EF), BSA-corrected maximum and minimum LA volume (Vi), stroke volume (SVi) were evaluated using bi-plane mode. LA global longitudinal strain (GLS) was defined with CMR based deformation imaging, called feature tracking.

Results

HTX patients had significantly higher LA volumes (maxLAVi 65 ± 22 vs. 46 ± 7 ml/m2, minLAVi 47 ± 21 vs. 18 ± 6 ml/m2) lower LASVi (19 ± 5 vs. 29 ± 4 ml/m2), LAEF (31 ± 10 vs. 62 ± 8%) and LA-GLS (10 ± 4 vs. 39 ± 11%) compared to the control group (p < 0.0001).  Analysing the temporal changes in HTX patients, we found an increase in the LA-GLS already at three months (10 ± 4 vs. 12 ± 3%, p < 0.05). The LAEF improved significantly at six months (29 ± 10 vs. 33 ± 10%, p < 0.05).

Conclusion

After HTX the LA volumes and function differ markedly from the normal population. The LA funcional parameters showed a moderate improvement after HTX. Better understanding the changes of left atrial function after HTX could help us to recognise  pathological conditions.

Abstract Figure. Strain analysis of the left atrium
Fully automated artificial intelligence-based myocardial scar quantification for diagnostic and prognostic stratification in patients following acute myocardial infarction
Authors: Lange T , Stiermaier T , Backhaus SJ , Boom P , Kowallick JT , Lotz J , Kutty S , Bigalke B , Gutberlet M , De Waha-Thiele S , Desch S , Hasenfuss G , Thiele H , Eitel I , Schuster A
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Background Myocardial infarct size (IS) remains one of the strongest predictors of adverse cardiac events following acute myocardial infarction (AMI). Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) can precisely quantify the extent of injury but requires manual post-processing. Whether novel user-independent artificial intelligence (AI) based fully-automated analyses may facilitate clinical workflow and deliver similar information for risk stratification is unknown.

Methods 913 AMI patients from two multi-center trials (AIDA-STEMI n = 704 with ST-elevation myocardial infarction [STEMI] and TATORT-NSTEMI n = 245 with non-ST-elevation-infarction [NSTEMI]) were included in this sub-study. IS was quantified manually using conventional software (Medis, Leiden Netherlands) and fully automated AI-based software (NeoSoft). All automatically detected IS were evaluated visually and corrected if necessary. Analyzed data were tested for agreement and prediction of major adverse clinical events (MACE) within one year after AMI.

Results Automated and manual IS were similarly associated with outcome in cox regression analyses (HR 1.05 [95% CI 1-02-1.07] p < 0.001 for automated IS and HR 1.04 [95% CI 1.02-1.06]; p < 0.001 for manual IS). Comparison of C-statistics derived area under the curve (AUC) resulted in equivalent MACE prediction (AUC 0.65 for automated vs. AUC 0.66 for manual, p = 0.53). Manual correction of the automated scar detection did not lead to an improved risk prediction of MACE (AUC 0.65 to 0.66, p = 0.43). There was good agreement of automated and manually derived IS (intraclass correlation coefficient [ICC] 0.75 [0.07-0.89]) which was further improved after manual correction of the underlying contours (ICC 0.98 [0.97-0.98]).

Conclusion AI-based software enables automated scar quantification with similar prognostic value compared to conventional methods in patients following AMI.
Long-term risk of sudden cardiac death in hypertrophic cardiomyopathy - a cardiac magnetic resonance outcome study
Authors: Seitz A , Greulich S , Herter D , Guenther F , Probst S , Bekeredjian R , Gawaz M , Sechtem U , Mahrholdt H
Published: February 2021

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Robert Bosch Stiftung; Deutsche Forschungsgemeinschaft

Background

Sudden cardiac death (SCD) is an appalling complication of hypertrophic cardiomyopathy (HCM). There is an ongoing discussion about the optimal SCD risk stratification strategy in HCM since established SCD risk models have suboptimal discriminative power.

Objective

To evaluate the prognostic value of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for SCD risk stratification compared to the ESC SCD risk score and traditional SCD risk factors in an >10-year follow-up study.

Methods

220 consecutive patients with HCM and LGE-CMR were enrolled. Follow-up data was available in 203 patients (median age 58 years, 61% male) after a median follow-up period of 10.4 years.

Results

LGE was present in 70% of patients with a median LGE amount of 1.6%, the median ESC 5-year SCD risk score was 1.84. In the overall cohort, SCD rates were 2.3% at 5 years, 4.8% at 10 years, and 15.7% at 15 years, independent from established risk models. A LGE amount of >5% (LV mass) portends the highest risk for SCD with SCD prevalences of 5.5% at 5 years, 13.0% at 10 years and 33.3% at 15 years. Conversely, patients with no or ≤5% LGE amount (of LV mass) have favorable prognosis.

Conclusions

LGE-CMR in HCM patients allows effective 10-year SCD risk stratification beyond established risk factors. LGE amount might be added to established risk models to improve its discriminatory power. Specifically, patients with >5% amount of LGE should be carefully monitored and might be adequate candidates for primary prevention ICD during the clinical long-term course.

Abstract Figure.
Prediction error aggregation behaviour for remote sensing augmented forest inventory approaches
Authors: Kotivuori Eetu , Maltamo Matti , Korhonen Lauri , Strunk Jacob L , Packalen Petteri
Published: February 2021

In this study we investigated the behaviour of aggregate prediction errors in a forest inventory augmented with multispectral Airborne Laser Scanning and airborne imagery. We compared an Area-Based Approach (ABA), Edge-tree corrected ABA (EABA) and Individual Tree Detection (ITD). The study used 109 large 30 × 30 m sample plots, which were divided into four 15 × 15 m subplots. Four different levels of aggregation were examined: all four subplots (quartet), two diagonal subplots (diagonal), two edge-adjacent subplots (adjacent) and subplots without aggregation. We noted that the errors at aggregated levels depend on the selected predictor variables, and therefore, this effect was studied by repeating the variable selection 200 times. At the subplot level, EABA provided the lowest mean of root mean square error ($\overline{\mathrm{RMSE}}$) values of 200 repetitions for total stem volume (EABA 21.1 percent, ABA 23.5 percent, ITD 26.2 percent). EABA also fared the best for diagonal and adjacent aggregation ($\overline{\mathrm{RMSE}}$: 17.6 percent, 17.4 percent), followed by ABA ($\overline{\mathrm{RMSE}}$: 19.3 percent, 18.2 percent) and ITD ($\overline{\mathrm{RMSE}}$: 21.8, 21.9 percent). Adjacent subplot errors of ABA were less correlated than errors of diagonal subplots, which resulted also in clearly lower RMSEs for adjacent subplots. This appears to result from edge tree effects, where omission and commission errors cancel for trees leaning from one subplot into the other. The best aggregate performance was achieved at the quartet level, as expected from fundamental properties of variance. ABA and EABA had similar RMSEs at the quartet level ($\overline{\mathrm{RMSE}}$ 15.5 and 15.3 percent), with poorer ITD performance ($\overline{\mathrm{RMSE}}$ 19.4 percent).
Network analysis of earthquake ground motion spatial correlation: a case study with the San Jacinto seismic nodal array
Authors: Sheng Yixiao , Kong Qingkai , Beroza Gregory C
Published: February 2021

The spatial correlation of earthquake ground motion intensity can be measured from strong motion data; however, the data used in past studies is sparsely sampled in space, and only the interstation distance was considered as a correlation variable. These limitations mean that we have only weak constraints on the true correlation structure of ground motion and that potentially important aspects of spatial correlation are unconstrained. In this study, we combine a large-N seismic array and graph analytics to explore this issue at a local scale using small local and regional earthquakes. Our result suggests site conditions, and how they interact with the incident seismic wavefield, strongly condition the spatial correlation of ground motion. Future progress in characterizing ground motion spatial variability will require dense wavefield measurements, either through nodal deployments, or perhaps distributed acoustic sensing measurements, of seismic wavefields. Aftershock sequences of major earthquakes would provide particularly data-rich targets of opportunity.
Characterization of drilling-related noise and curvelet-based evaluation of seismic-interferometric reflections for imaging of iron-bearing formations in Pilbara, Western Australia
Authors: Chamarczuk M , Malinowski M , Draganov D , Grant A , Asgharzadeh M , Urosevic M
Published: February 2021

Here we analyse ambient noise (AN) data generated during drilling of exploration boreholes and recorded using a dense array deployed over one of the numerous shallow iron-ore mineralization targets in the Pilbara region (Western Australia). Drilling and drilling-related operations were reoccurring in a sequence as described by the drillers’ field notes, which created the rare opportunity to analyse AN data in time segments when only one type of technical process was predominantly active. Consequently, most of the recorded AN sources did not overlap in time and space. We extract the recordings in 15-min-long segments matching the time-span of single field-note entry and identify individually acting AN sources associated with specific field operations. The temporal variations of noise spectrograms and AN cross-correlations show dependency on the sequence of a few consecutive field operations and specific frequency–amplitude patterns associated with single field operations. These changes are directly reflected by the events visible in the retrieved virtual-source gathers (VSG), implying significant changes in noise temporal and spatial stationarity. Some VSGs represent the mixed contributions of surface and air waves. To remove the contributions of these arrivals to the reflection imaging, we visually inspect all data and select only field operations acting as stationary-phase sources specifically for the reflection retrieval. This was done for different receiver configurations inside PilbArray, and as a result, we obtain a collection of VSGs containing coherent body-wave reflections. Database of visually inspected VSGs is used to develop and benchmark a semi-automatic curvelet-based method for accurate parametrization of the reflection events retrieved from passive data and to compare the imaging quality of the different field operations. Common-midpoint stacks from manually and automatically selected VSGs show reflectivity consistent with the one obtained from the active-source data and related to the structure hosting shallow iron mineralization. Our results demonstrate the capacity of AN seismic interferometry to retrieve body-wave reflections and image shallow mineralization. They also provide an intermediate step toward automating the passive reflection imaging with similar data sets.
Social inequalities in availability of health-promoting interventions in Québec elementary schools
Authors: Riglea Teodora , Kalubi Jodi , Sylvestre Marie-Pierre , Maximova Katerina , Dutczak Hartley , Gariépy Geneviève , O’Loughlin Jennifer
Published: February 2021

Availability of health-promoting interventions (HPIs) may vary across schools serving students with different socioeconomic backgrounds. Our objectives were to describe social inequalities across elementary schools in: (i) level of importance that school principals attribute to 13 common health-related issues among students in their school; (ii) availability of HPIs within their school addressing eight health topics and (iii) (mis)alignment between perceived importance and HPI availability. Data were collected in telephone interviews with school principals in a convenience sample of 171 elementary schools (59% of 291 schools contacted). Schools were categorized as serving very advantaged, moderately advantaged or disadvantaged students. Principals reported how important 13 health issues were among students in their schools and provided data on HPI availability for 8 health issues, 4 of which required school action under government mandates. Higher proportions of principals in schools serving disadvantaged students (36% of all 171 schools) perceived most health issues as important. The mean number of HPIs in the past year was 12.0, 12.1 and 11.7 in schools serving very advantaged, moderately advantaged and disadvantaged students, respectively. Only availability of mental health HPIs differed by school deprivation (60, 43 and 30% in very, moderately and disadvantaged, respectively). Although most schools offered oral health HPIs, dental problems were not perceived as important. Smoking was perceived as not important and smoking-related HPIs were relatively rare (9%). Given rapid evolution in public health priorities, (mis)alignment between perceived importance of specific health issues and HPI availability in elementary schools warrants ongoing reflection.
Ultra mare in servicio domini regis: English barons and the defence of Normandy, 1194–1204
Authors: Hopkinson Nick
Published: February 2021

This article analyses the provision of military service by English barons in the wars in Normandy between 1194 and 1204, a topic that has not previously been examined in any depth. It demonstrates that an important section of the English baronage provided regular military service in Normandy, driven by their own personal interests in the duchy and the pursuit of royal favour and rewards. It concludes that these barons were not fundamentally opposed to providing service overseas, and that this was not a factor in the loss of Normandy, but became an important political lever in their conflict with King John.
Evolutionary forces in diabetes and hypertension pathogenesis in Africans
Authors: Meeks Karlijn A C , Bentley Amy R , Adeyemo Adebowale A , Rotimi Charles N
Published: February 2021

Rates of type 2 diabetes (T2D) and hypertension are increasing rapidly in urbanizing sub-Saharan Africa (SSA). While lifestyle factors drive the increases in T2D and hypertension prevalence, evidence across populations shows that genetic variation, which is driven by evolutionary forces including a natural selection that shaped the human genome, also plays a role. Here we report the evidence for the effect of selection in African genomes on mechanisms underlying T2D and hypertension, including energy metabolism, adipose tissue biology, insulin action and salt retention. Selection effects found for variants in genes PPARA and TCF7L2 may have enabled Africans to respond to nutritional challenges by altering carbohydrate and lipid metabolism. Likewise, African-ancestry-specific characteristics of adipose tissue biology (low visceral adipose tissue [VAT], high intermuscular adipose tissue and a strong association between VAT and adiponectin) may have been selected for in response to nutritional and infectious disease challenges in the African environment. Evidence for selection effects on insulin action, including insulin resistance and secretion, has been found for several genes including MPHOSPH9, TMEM127, ZRANB3 and MC3R. These effects may have been historically adaptive in critical conditions, such as famine and inflammation. A strong correlation between hypertension susceptibility variants and latitude supports the hypothesis of selection for salt retention mechanisms in warm, humid climates. Nevertheless, adaptive genomics studies in African populations are scarce. More work is needed, particularly genomics studies covering the wide diversity of African populations in SSA and Africans in diaspora, as well as further functional assessment of established risk loci.
Locally Complete Intersection Maps and the Proxy Small Property
Authors: Briggs Benjamin , Iyengar Srikanth B , Letz Janina C , Pollitz Josh
Published: February 2021

It is proved that a map ${\varphi }\colon R\to S$ of commutative Noetherian rings that is essentially of finite type and flat is locally complete intersection if and only if $S$ is proxy small as a bimodule. This means that the thick subcategory generated by $S$ as a module over the enveloping algebra $S\otimes _RS$ contains a perfect complex supported fully on the diagonal ideal. This is in the spirit of the classical result that ${\varphi }$ is smooth if and only if $S$ is small as a bimodule; that is to say, it is itself equivalent to a perfect complex. The geometric analogue, dealing with maps between schemes, is also established. Applications include simpler proofs of factorization theorems for locally complete intersection maps.
Feeling better on hemodialysis: user-centered design requirements for promoting patient involvement in the prevention of treatment complications
Authors: Willis Matthew A , Hein Leah Brand , Hu Zhaoxian , Saran Rajiv , Argentina Marissa , Bragg-Gresham Jennifer , Krein Sarah L , Gillespie Brenda , Zheng Kai , Veinot Tiffany C
Published: February 2021

Objective

Hemodialysis patients frequently experience dialysis therapy sessions complicated by intradialytic hypotension (IDH), a major patient safety concern. We investigate user-centered design requirements for a theory-informed, peer mentoring-based, informatics intervention to activate patients toward IDH prevention.

Methods

We conducted observations (156 hours) and interviews (n = 28) with patients in 3 hemodialysis clinics, followed by 9 focus groups (including participatory design activities) with patients (n = 17). Inductive and deductive analyses resulted in themes and design principles linked to constructs from social, cognitive, and self-determination theories.

Results

Hemodialysis patients want an informatics intervention for IDH prevention that collapses distance between patients, peers, and family; harnesses patients’ strength of character and resolve in all parts of their life; respects and supports patients’ individual needs, preferences, and choices; and links “feeling better on dialysis” to becoming more involved in IDH prevention. Related design principles included designing for: depth of interpersonal connections; positivity; individual choice and initiative; and comprehension of connections and possible actions.

Discussion

Findings advance the design of informatics interventions by presenting design requirements for outpatient safety and addressing key design opportunities for informatics to support patient involvement; these include incorporation of behavior change theories. Results also demonstrate the meaning of design choices for hemodialysis patients in the context of their experiences; this may have applicability to other populations with serious illnesses.

Conclusion

The resulting patient-facing informatics intervention will be evaluated in a pragmatic cluster-randomized controlled trial in 28 hemodialysis facilities in 4 US regions.
Conflicting information from the Food and Drug Administration: Missed opportunity to lead standards for safe and effective medical artificial intelligence solutions
Authors: Hernandez-Boussard Tina , Lundgren Matthew P , Shah Nigam
Published: February 2021

The Food & Drug Administration (FDA) is considering the permanent exemption of premarket notification requirements for several Class I and II medical device products, including several artificial Intelligence (AI)–driven devices. The exemption is based on the need to rapidly more quickly disseminate devices to the public, estimated cost-savings, a lack of documented adverse events reported to the FDA’s database. However, this ignores emerging issues related to AI-based devices, including utility, reproducibility and bias that may not only affect an individual but entire populations. We urge the FDA to reinforce the messaging on safety and effectiveness regulations of AI-based Software as a Medical Device products to better promote fair AI-driven clinical decision tools and for preventing harm to the patients we serve.