bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of respiratory motion artifacts in gadoxetate-enhanced MR with a deep learning–based filter using convolutional neural network
Authors: Kromrey M.-L. , Tamada D. , Johno H. , Funayama S. , Nagata N. , Ichikawa S. , Kühn J.-P. , Onishi H. , Motosugi U.
Published: June 2020

Objectives

To reveal the utility of motion artifact reduction with convolutional neural network (MARC) in gadoxetate disodium–enhanced multi-arterial phase MRI of the liver.

Methods

This retrospective study included 192 patients (131 men, 68.7 ± 10.3 years) receiving gadoxetate disodium–enhanced liver MRI in 2017. Datasets were submitted to a newly developed filter (MARC), consisting of 7 convolutional layers, and trained on 14,190 cropped images generated from abdominal MR images. Motion artifact for training was simulated by adding periodic k-space domain noise to the images. Original and filtered images of pre-contrast and 6 arterial phases (7 image sets per patient resulting in 1344 sets in total) were evaluated regarding motion artifacts on a 4-point scale. Lesion conspicuity in original and filtered images was ranked by side-by-side comparison.

Results

Of the 1344 original image sets, motion artifact score was 2 in 597, 3 in 165, and 4 in 54 sets. MARC significantly improved image quality over all phases showing an average motion artifact score of 1.97 ± 0.72 compared to 2.53 ± 0.71 in original MR images (p < 0.001). MARC improved motion scores from 2 to 1 in 177/596 (29.65%), from 3 to 2 in 119/165 (72.12%), and from 4 to 3 in 34/54 sets (62.96%). Lesion conspicuity was significantly improved (p < 0.001) without removing anatomical details.

Conclusions

Motion artifacts and lesion conspicuity of gadoxetate disodium–enhanced arterial phase liver MRI were significantly improved by the MARC filter, especially in cases with substantial artifacts. This method can be of high clinical value in subjects with failing breath-hold in the scan.

Key Points

• This study presents a newly developed deep learning–based filter for artifact reduction using convolutional neural network (motion artifact reduction with convolutional neural network, MARC).

• MARC significantly improved MR image quality after gadoxetate disodium administration by reducing motion artifacts, especially in cases with severely degraded images.

• Postprocessing with MARC led to better lesion conspicuity without removing anatomical details.
How to create an operational multi-model of seasonal forecasts?
Authors: Hemri Stephan , Bhend Jonas , Liniger Mark A. , Manzanas Rodrigo , Siegert Stefan , Stephenson David B. , Gutiérrez José M. , Brookshaw Anca , Doblas-Reyes Francisco J.
Published: June 2020

Seasonal forecasts of variables like near-surface temperature or precipitation are becoming increasingly important for a wide range of stakeholders. Due to the many possibilities of recalibrating, combining, and verifying ensemble forecasts, there are ambiguities of which methods are most suitable. To address this we compare approaches how to process and verify multi-model seasonal forecasts based on a scientific assessment performed within the framework of the EU Copernicus Climate Change Service (C3S) Quality Assurance for Multi-model Seasonal Forecast Products (QA4Seas) contract C3S 51 lot 3. Our results underpin the importance of processing raw ensemble forecasts differently depending on the final forecast product needed. While ensemble forecasts benefit a lot from bias correction using climate conserving recalibration, this is not the case for the intrinsically bias adjusted multi-category probability forecasts. The same applies for multi-model combination. In this paper, we apply simple, but effective, approaches for multi-model combination of both forecast formats. Further, based on existing literature we recommend to use proper scoring rules like a sample version of the continuous ranked probability score and the ranked probability score for the verification of ensemble forecasts and multi-category probability forecasts, respectively. For a detailed global visualization of calibration as well as bias and dispersion errors, using the Chi-square decomposition of rank histograms proved to be appropriate for the analysis performed within QA4Seas.
The contributions of fronts, lows and thunderstorms to southern Australian rainfall
Authors: Pepler Acacia S. , Dowdy Andrew J. , van Rensch Peter , Rudeva Irina , Catto Jennifer L. , Hope Pandora
Published: June 2020

A systematic analysis of the main weather types influencing southern Australian rainfall is presented for the period 1979–2015. This incorporates two multi-method datasets of cold fronts and low pressure systems, which indicate the more robust fronts and lows as distinguished from the weaker and less impactful events that are often indicated only by a single method. The front and low pressure system datasets are then combined with a dataset of environmental conditions associated with thunderstorms, as well as datasets of warm fronts and high pressure systems. The results demonstrate that these weather types collectively account for about 86% of days and more than 98% of rainfall in Australia south of 25° S. We also show how the key rain-bearing weather systems vary throughout the year and for different regions, with the co-occurrence of simultaneous lows, fronts and thunderstorm conditions particularly important during the spring and summer months in southeast Australia.
Sporadic colorectal cancer in adolescents and young adults: a scoping review of a growing healthcare concern
Authors: Christodoulides Natasha , Lami Mariam , Malietzis George , Rasheed Shahnawaz , Tekkis Paris , Kontovounisios Christos
Published: June 2020

Purpose

Sporadic colorectal cancer (CRC) amongst adolescents and young adults (AYA) is increasing in incidence. The reasons for this trend are not well understood. Current guidelines do not specifically address this patient cohort. A scoping review was performed to summarise the range of available evidence and identify key areas that need to be addressed in current guidelines.

Methods

A systematic literature search was conducted adhering to the PRISMA statement. All potentially eligible studies were screened, and data extraction was performed by two reviewers independently. The studies were then divided into 5 broad subgroups: (1) risk factors, (2) screening, (3) clinicopathological and molecular features, (4) presentation and (5) management. Descriptive statistics were used for data analysis.

Results

A total of 17 studies were included from 2010 to 2019. Overall, young adults with CRC tend to present with non-specific symptoms. The majority of these patients have a delayed diagnosis and more advanced disease at presentation, with a rise in prevalence of distal colon and rectal cancers. AYAs tend to have poorly differentiated tumours and are managed more aggressively. Overall 5-year survival varies between studies.

Conclusion

This is, to our knowledge, the first scoping review presenting the range of available evidence on CRC in AYAs. Although the rise in incidence is recognised by specialist bodies, recommendations are limited by the sparsity of available data. We seek to highlight the need for further research, define the role of earlier screening and raise awareness to promote thorough assessment of young patients.
Anaemia is associated with severe RBC dysfunction and a reduced circulating NO pool: vascular and cardiac eNOS are crucial for the adaptation to anaemia
Authors: Wischmann Patricia , Kuhn Viktoria , Suvorava Tatsiana , Muessig Johanna M. , Fischer Jens W. , Isakson Brant E. , Haberkorn Sebastian M. , Flögel Ulrich , Schrader Jürgen , Jung Christian , Cortese-Krott Miriam M. , Heusch Gerd , Kelm Malte
Published: June 2020

Anaemia is frequently present in patients with acute myocardial infarction (AMI) and contributes to an adverse prognosis. We hypothesised that, besides reduced oxygen carrying capacity, anaemia is associated with (1) red blood cell (RBC) dysfunction and a reduced circulating nitric oxide (NO) pool, (2) compensatory enhancement of vascular and cardiac endothelial nitric oxide synthase (eNOS) activity, and (3) contribution of both, RBC dysfunction and reduced circulatory NO pool to left ventricular (LV) dysfunction and fatal outcome in AMI. In mouse models of subacute and chronic anaemia from repeated mild blood loss the circulating NO pool, RBC, cardiac and vascular function were analysed at baseline and in reperfused AMI. In anaemia, RBC function resulted in profound changes in membrane properties, enhanced turnover, haemolysis, dysregulation of intra-erythrocytotic redox state, and RBC-eNOS. RBC from anaemic mice and from anaemic patients with acute coronary syndrome impaired the recovery of contractile function of isolated mouse hearts following ischaemia/reperfusion. In anaemia, the circulating NO pool was reduced. The cardiac and vascular adaptation to anaemia was characterised by increased arterial eNOS expression and activity and an eNOS-dependent increase of end-diastolic left ventricular volume. Endothelial dysfunction induced through genetic or pharmacologic reduction of eNOS-activity abrogated the anaemia-induced cardio-circulatory compensation. Superimposed AMI was associated with decreased survival. In summary, moderate blood loss anaemia is associated with severe RBC dysfunction and reduced circulating NO pool. Vascular and cardiac eNOS are crucial for the cardio-circulatory adaptation to anaemia. RBC dysfunction together with eNOS dysfunction may contribute to adverse outcomes in AMI.
Mucinous borderline ovarian tumors with BRAFV600E mutation may have low risk for progression to invasive carcinomas
Authors: Ohnishi Kaori , Nakayama Kentaro , Ishikawa Masako , Ishibashi Tomoka , Yamashita Hitomi , Nakamura Kohei , Minamoto Toshiko , Iida Kouji , Razia Sultana , Ishikawa Noriyoshi , Kyo Satoru
Published: June 2020

Purpose

Mucinous ovarian carcinomas (MOCs) are relatively rare. It has been proposed that a subset of mucinous cystadenomas (MCAs) may progress to mucinous borderline tumors (MBTs), and then to MOCs. KRAS is the predominantly mutated gene in MOC; however, other associated mutations and the mechanism underlying carcinogenesis in MOC remain unclear. Here, we assessed molecular genetic alterations in mucinous ovarian tumors and constructed mutation profiles.

Methods

Using the Sanger sequencing method, we assessed genetic mutations (KRAS, BRAF, TP53, and PIK3CA) in 16 cases of MOC, 10 cases of MBT, and 12 cases of MCA.

Results

Among MOC cases, the prevalence of G12D and G13D KRAS mutations was 43.8% (7/16). No MOC cases showed V600E BRAF and TP53 mutations. Among MBT cases, the prevalence of G12D KRAS mutation was 20.0% (2/10), those of TP53 and PIK3CA mutations were nil, and that of V600E BRAF mutation was 40% (4/10). None of the genetic mutations assessed were detected among MCA cases.

Conclusion

These results suggest that MBT with V600E BRAF mutation may rarely progress to MOC, while MBT with G12D or G13D KRAS mutation may more commonly progress to MOC.
Effects of transcranial direct current stimulation of left and right inferior frontal gyrus on creative divergent thinking are moderated by changes in inhibition control
Authors: Khalil Radwa , Karim Ahmed A. , Kondinska Angela , Godde Ben
Published: June 2020

Divergent thinking (DT) as one component of creativity is the ability to search for multiple solutions to a single problem and is reliably tested with the Alternative Uses Task (AUT). DT depends on activity in the inferior frontal gyrus (IFG), a prefrontal region that has also been associated with inhibitory control (IC). Experimentally manipulating IC through transcranial direct current stimulation (tDCS) led to alterations in DT. Here, we aimed at further examining such potential mediating effects of IC on DT (measured as flexibility, fluency, and originality in the AUT) by modulating IC tDCS. Participants received either cathodal tDCS (c-tDCS) of the left IFG coupled with anodal tDCS (a-tDCS) of the right IFG (L−R + ; N = 19), or the opposite treatment (L + R−; N = 21). We hypothesized that L + R− stimulation would enhance IC assessed with the Go NoGo task (GNGT), and that facilitated IC would result in lower creativity scores. The reversed stimulation arrangement (i.e., L− R +) should result in higher creativity scores. We found that tDCS only affected the originality component of the AUT but not flexibility or fluency. We also found no effects on IC, and thus, the mediation effect of IC could not be confirmed. However, we observed a moderation effect: inhibition of left and facilitation of right IFG (L−R +) resulted in enhanced flexibility and originality scores, only when IC performance was also improved. We conclude that inducing a right-to-left gradient in IFG activity by tDCS is efficient in enhancing DT, but only under conditions where tDCS is sufficient to alter IC performance as well.
Besnoitia besnoiti–driven endothelial host cell cycle alteration
Authors: Velásquez Zahady D. , Lopez-Osorio Sara , Pervizaj-Oruqaj Learta , Herold Susanne , Hermosilla Carlos , Taubert Anja
Published: June 2020

Besnoitia besnoiti is an important obligate intracellular parasite of cattle which primarily infects host endothelial cells of blood vessels during the acute phase of infection. Similar to the closely related parasite Toxoplasma gondii, B. besnoiti has fast proliferating properties leading to rapid host cell lysis within 24–30 h p.i. in vitro. Some apicomplexan parasites were demonstrated to modulate the host cellular cell cycle to successfully perform their intracellular development. As such, we recently demonstrated that T. gondii tachyzoites induce G2/M arrest accompanied by chromosome missegregation, cell spindle alteration, formation of supernumerary centrosomes, and cytokinesis impairment when infecting primary bovine umbilical vein endothelial cells (BUVEC). Here, we follow a comparative approach by using the same host endothelial cell system for B. besnoiti infections. The current data showed that—in terms of host cell cycle modulation—infections of BUVEC by B. besnoiti tachyzoites indeed differ significantly from those by T. gondii. As such, cyclin expression patterns demonstrated a significant upregulation of cyclin E1 in B. besnoiti–infected BUVEC, thereby indicating parasite-driven host cell stasis at G1-to-S phase transition. In line, the mitotic phase of host cell cycle was not influenced since alterations of chromosome segregation, mitotic spindle formation, and cytokinesis were not observed. In contrast to respective T. gondii–related data, we furthermore found a significant upregulation of histone H3 (S10) phosphorylation in B. besnoiti–infected BUVEC, thereby indicating enhanced chromosome condensation to occur in these cells. In line to altered G1/S-transition, we here additionally showed that subcellular abundance of proliferating cell nuclear antigen (PCNA), a marker for G1 and S phase sub-stages, was affected by B. besnoiti since infected cells showed increased nuclear PCNA levels when compared with that of control cells.
A novel difficulty grading system for laparoscopic living donor nephrectomy
Authors: Takagi Kosei , Kimenai Hendrikus J. A. N. , Terkivatan Turkan , Tran Khe T. C. , Ijzermans Jan N. M. , Minnee Robert C.
Published: June 2020

Background

Several difficulty grading systems have been developed as a useful tool for selecting patients and training surgeons in laparoscopic procedures. However, there is little information on predicting the difficulty of laparoscopic donor nephrectomy (LDN). The aim of this study was to develop a grading system to predict the difficulty of LDN.

Methods

Data of 1741 living donors, who underwent pure or hand-assisted LDN between 1994 and 2018 were analyzed. Multivariable analyses were performed to identify factors associated with prolonged operative time, defined as a difficulty index with 0 to 8. The difficulty of LDN was classified into three levels based on the difficulty index.

Results

Multivariable analyses identified that male (odds ratio [OR] 1.69, 95% CI 1.37–2.09, P < 0.001), BMI > 28 (OR 1.36, 95% CI 1.08–1.72, P = 0.009), pure LDN (OR 1.99, 95% CI 1.53–2.60, P < 0.001), multiple renal arteries (OR 2.38, 95% CI 1.83–3.10, P < 0.001) and multiple renal veins (OR 2.18, 95% CI 1.52–3.16, P < 0.001) were independent risk factors influencing prolonged operative time. The difficulty index based on these factors was calculated and categorized into three levels: low (0–2), intermediate (3–5), and high (6–8) difficulty. Operative time was significantly longer in the high difficulty group (225 min) than in the low (169 min, P < 0.001) and intermediate difficulty group (194 min, P < 0.001). The conversion rate was higher in the high difficulty group (4.4%) than in the low (2.1%, P = 0.04) and the intermediate difficulty group (3.0%, P = 0.27). No significant difference in major complications was found between the groups.

Conclusion

We developed a novel grading system with simple preoperative donor factors to predict the difficulty of LDN. This grading system may help surgeons in patient selection to advance their experiences and/or teach fellows from simple to difficult LDN.
Influence of operative timing on the early post-operative radiological and clinical outcome after kyphoplasty
Authors: Palmowski Yannick , Balmer Sophie , Bürger Justus , Schömig Friederike , Hu Zhouyang , Pumberger Matthias
Published: June 2020

Purpose

To clarify the relationship between operative timing and the early post-operative radiological and clinical outcome after kyphoplasty.

Methods

We conducted a retrospective cohort study including patients who underwent kyphoplasty of a single vertebra. Patients were divided into three groups (acute [< 2 weeks], subacute [2–6 weeks] or chronic [6–51 weeks]) based on the interval between fracture and surgery. The relative vertebral body height (VBH) and local kyphotic angle (LKA) of the fractured vertebra (measured on plain radiographs) as well as pain and use of analgesics were compared pre- and post-operatively (day 2) and between the groups.

Results

A total of 230 patients (100 with acute, 91 with subacute and 39 with chronic fractures) with fractures from T4 to L5 were included. In all groups, there was a significant post-operative improvement in the anterior (8.9–12.9%) and middle (10.7–13.4%) VBH (all groups: p < 0.001), LKA (acute: 3.8°, p < 0.001; subacute: 4.3°, p < 0.001; chronic: 1.7°, p = 0.046) and pain. The use of analgesics significantly decreased post-operatively in the acute and subacute groups, but did not significantly change in the chronic group. Patients from acute (p = 0.042) and subacute (p = 0.027) groups showed significantly better post-operative correction of the LKA than the chronic group.

Conclusion

Kyphoplasty is effective for vertebral height restoration as well as pain relief for both acute, subacute and chronic fractures. However, the achievable correction of the fracture-related local kyphosis decreases significantly after 6 weeks. Therefore, we recommend making a final decision about conservative vs. operative treatment within 6 weeks to ensure better height restoration in surgically treated patients.
The importance of multisection sagittal and coronal magnetic resonance imaging evaluation in the assessment of temporomandibular joint disc position
Authors: Litko-Rola Monika , Szkutnik Jacek , Różyło-Kalinowska Ingrid
Published: June 2020

Objectives

The aim of this study was to evaluate diagnoses of temporomandibular (TMJ) disc displacement by comparing evaluations done on the basis of central sagittal scans only, the most often used in temporomandibular disorder (TMD) patients, with a multisection evaluation done with both sagittal and coronal scans.

Materials and methods

Multisection MRI analysis of 382 TMJs was conducted in 191 patients with disc displacement according to RDC/TMD criteria. Disc position in the intercuspal position (IP) was assessed two times using two different methods. The first method involved a TMJ disc position evaluation on the central slide in the oblique sagittal plane only. In the second method, the TMJ disc position was assessed on all oblique sagittal and coronal images. McNemar’s χ2 test was used to evaluate the differences between the sensitivities of two methods.

Results

The first method (central oblique sagittal scans assessment) identified 148 TMJs (38.7%) with normal disc position compared with 89 TMJs (23.3%) with normal disc position found by the second method (all oblique sagittal and coronal scans assessment). The sensitivity of analysis in both planes was significantly higher than in the sagittal plane only (p < 0.001).

Conclusions

The multisection analysis in the sagittal and coronal plane allows to distinguish the correct disc position from disc displacement and thus improve evaluation of TMJ internal derangement.

Clinical relevance

The multisection sagittal and coronal images should be recommended as a standard in MRI of the TMJ disc displacement in patients with TMD to avoid false-negative diagnoses.
Hyperspectral analysis for perioperative perfusion monitoring—a clinical feasibility study on free and pedicled flaps
Authors: Thiem D. G. E. , Frick R. W. , Goetze E. , Gielisch M. , Al-Nawas B. , Kämmerer P. W.
Published: June 2020

Objectives

In reconstructive surgery, flap monitoring is crucial for early identification of perfusion problems. Using hyperspectral imaging (HSI), this clinical study aimed to develop a non-invasive, objective approach for perfusion monitoring of free and pedicled flaps.

Material and methods

HSI of 22 free (FF) and 8 pedicled flaps (PF) in 30 patients was recorded over time. Parameters assessed were tissue oxygenation/superficial perfusion (0–1 mm) (StO2 (0–100%)), near-infrared perfusion/deep perfusion (0–4 mm) (NIR (0–100)), distribution of haemoglobin (THI (0–100)), and water (TWI (0–100)). Measurements up to 72 h were correlated to clinical assessment.

Results

Directly after flap inset, mean StO2 was significantly higher in FF (70.3 ± 13.6%) compared with PF 56.2 ± 14.2% (p = 0.05), whereas NIR, THI, and TWI were similar (NIR_p = 0.82, THI_p = 0.97, TWI_p = 0.27). After 24 h, StO2, NIR, THI, and TWI did not differ between FF and PF. After 48 h, StO2, NIR, and TWI did not differ between FF and PF whereas THI was significantly increased in FF compared with PF(p = 0.001). In three FF, perfusion decreased clinically and in HSI, 36(1), 40(2), 5(3), and 61(3) h after flap inset which was followed by prompt intervention.

Conclusions

StO2 < 40%, NIR < 25/100, and THI < 40/100 indicated arterial occlusion, whereas venous problems revealed an increase of THI. In comparison with FF, perfusion parameters of PF were decreased after flap transfer but remained similar to FF later on.

Clinical relevance

HSI provides objective and non-invasive perfusion monitoring after flap transplantation in accordance to the clinical situation. With HSI, signs of deterioration can be detected hours before clinical diagnosis.
Measuring the polymerization stress of self-adhesive resin composite cements by crack propagation
Authors: Wiedenmann Felicitas , Becker Fabian , Eichberger Marlis , Stawarczyk Bogna
Published: June 2020

Objectives

To test the polymerization stress of nine self-adhesive resin composite cements (G-CEM, iCEM, Bifix SE, Maxcem Elite, PANAVIA SA, SoloCem, SmartCem 2, SpeedCEM, RelyX Unicem 2) and one glass ionomer cement (control group; Ketac Cem).

Materials and methods

The crack propagation of a feldspar ceramic (n = 130) was determined by measuring crack lengths that originated from Vickers indentations, prior to and after the application and polymerization of the self-adhesive resin cements. Results for crack propagation were converted to polymerization stress values, and statistical analysis was performed using one-way ANOVA followed by Scheffé post hoc test.

Results

SmartCem 2 presented higher stress values than iCEM, SoloCem, and Ketac Cem, while Ketac Cem showed lower values than Bifix SE, Maxcem Elite, SmartCem 2, SpeedCEM, and RelyX Unicem 2.

Conclusions

Self-adhesive resin composite cements differ in their polymerization stress, which may affect the durability of the restoration. For restorations made from ceramics with lower flexural strength, such as feldspar ceramics, resin composite cement materials with less polymerization stress should be preferred.

Clinical Relevance

As a high polymerization shrinkage may increase crack propagation, the determination of the polymerization stress of self-adhesive resin composite cements employed for fixing all-ceramic restorations is an important factor.
Transperineal minimally invasive APE: preliminary outcomes in a multicenter cohort
Authors: van Oostendorp S. E. , Roodbeen S. X. , Chen C. C. , Caycedo-Marulanda A. , Joshi H. M. , Tanis P. J. , Cunningham C. , Tuynman J. B. , Hompes R.
Published: June 2020

Background

Abdominoperineal excision (APE) for rectal cancer is associated with a relatively high risk of positive margins and postoperative morbidity, particularly related to perineal wound healing problems. It is unknown whether the use of a minimally invasive approach for the perineal part of these procedures can improve postoperative outcomes without oncological compromise. The aim of this study was to evaluate the feasibility of minimally invasive transperineal abdominoperineal excision (TpAPE)

Methods

This multicenter retrospective cohort study included all patients having TpAPE for primary low rectal cancer. The primary endpoint was the intraoperative complication rate. Secondary endpoints included major morbidity (Clavien–Dindo ≥ 3), histopathology results, and perineal wound healing.

Results

A total of 32 TpAPE procedures were performed in five centers. A bilateral extralevator APE (ELAPE) was performed in 17 patients (53%), a unilateral ELAPE in 7 (22%), and an APE in 8 (25%). Intraoperative complications occurred in five cases (16%) and severe postoperative morbidity in three cases (9%). There were no perioperative deaths. A positive margin (R1) was observed in four patients (13%) and specimen perforation occurred in two (6%). The unilateral extralevator TpAPE group had worse specimen quality and a higher proportion of R1 resections than the bilateral ELAPE or standard APE groups. The rate of uncomplicated perineal wound healing was 53% (n = 17) and three patients (9%) required surgical reintervention.

Conclusions

TpAPE seems to be feasible with acceptable perioperative morbidity and a relatively low rate of perineal wound dehiscence, while histopathological outcomes remain suboptimal. Additional evaluation of the viability of this technique is needed in the form of a prospective trial with standardization of the procedure, indication, audit of outcomes and performed by surgeons with vast experience in transanal total mesorectal excision.
Is time preference and present bias associated with the decision to start, quit or maintain physical activity over time?
Authors: Eberth Barbara , van der Pol Marjon , Kemenev Dmitri
Published: June 2020

Aim

It is commonly observed that individuals transition into and out of physical activity behaviours over time. A better understanding of the determinants of these transitions is important in order to develop effective interventions. Our focus is on examining the role of time preference and present bias (how present or future oriented individuals are) in the decision to start, quit and maintain physical activity over time.

Subject and methods

We examine changes in different types of physical activity participation over time, allowing us to distinguish between physical activity initiation versus maintenance. We use data from the National Longitudinal Survey of Youth 1979 (NLSY79).

Results

We show that present bias impacts maintenance but not initiation of physical activity behaviour. The time preference rate impacts maintenance of strengthening exercise in men only.

Conclusion

The results of our study suggest that interventions aimed at overcoming present bias, such as commitment devices in the form of deposit contracts, may be effective in maintaining physical activity but not initiating physical activity.
In situ TEM oxidation study of Fe thin-film transformation to single-crystal magnetite nanoparticles
Authors: Lari Leonardo , Steinhauer Stephan , Lazarov Vlado K.
Published: June 2020

In this work, we present an in situ transmission electron microscopy (TEM) study of Fe thin films to Fe nanoparticle formation and their oxidation to single-crystal magnetite nanoparticles. Amorphous Fe thin films were prepared by sputtering on TEM carbon grids. The thin Fe films were continuously heated in situ from room temperature to 700 °C under vacuum (4 × 10–4 Pa). With the increase in temperature, the continuity of the thin film starts breaking, and Fe nanoparticle nucleation centers are formed. At 600 °C, the thin film transforms into metallic Fe nanoparticles (NPs) with a small presence of different Fe oxide NPs. Further increase in the temperature to 700 °C resulted in the full oxidation of the NPs (i.e., no core–shell were found). Zero-loss energy filtered diffraction and HRTEM analysis of the lattice spacing reveals that all NPs have fully transformed into single-phase magnetite NPs. The structural study of the magnetite NPs shows that magnetite NPs are free of antiphase domain boundary defects. This work demonstrates that under low partial pressure of oxygen at elevated temperatures a complete oxidation of Fe NPs into magnetite single-crystal nanoparticles can be achieved.
An updated review of nanofluids in various heat transfer devices
Authors: Okonkwo Eric C. , Wole-Osho Ifeoluwa , Almanassra Ismail W. , Abdullatif Yasser M. , Al-Ansari Tareq
Published: June 2020

The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in the later part of the twentieth century. This is evident from the increased number of studies related to nanofluids published annually. The increasing attention on nanofluids is primarily due to their enhanced thermophysical properties and their ability to be incorporated into a wide range of thermal applications ranging from enhancing the effectiveness of heat exchangers used in industries to solar energy harvesting for renewable energy production. Owing to the increasing number of studies relating to nanofluids, there is a need for a holistic review of the progress and steps taken in 2019 concerning their application in heat transfer devices. This review takes a retrospective look at the year 2019 by reviewing the progress made in the area of nanofluids preparation and the applications of nanofluids in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling. This review aims to update readers on recent progress while also highlighting the challenges and future of nanofluids as the next-generation heat transfer fluids. Finally, a conclusion on the merits and demerits of nanofluids is presented along with recommendations for future studies that would mobilise the rapid commercialisation of nanofluids.
Causal inference in collaboration networks using propensity score methods
Authors: Windzio Michael
Published: June 2020

Using panel data of school-class networks of 11–13-year-old students, this study investigates effects of schoolwork collaboration-networks on grades and school-related well-being. It suggests propensity score weighting-regression as a method of causal inference for data collected in social contexts, and in studies analyzing node-attributes as outcomes of interest. It will argued that this alternative approach is useful when stochastic actor-based models (SAOMs) show convergence problems in sparse networks. Three methods of causal analysis dealing with the problems of endogeneity bias and interference between observations will be discussed in this study: first, SAOMs for the co-evolution of networks and behavior/attitudes will be estimated, but this results in a systematic loss of data. Second, propensity score matching compares treated cases with untreated nearest neighbors. However, the stable-unit-treatment-value assumption (SUTVA) requires that the analysis controls for network embeddedness in the final analysis. This is possible by using propensity score weighting-regression, which is a flexible approach to capture treatment diffusion via multiplex networks.
Changes in Income Distribution for Different Family Types in Poland
Authors: Jędrzejczak Alina , Pekasiewicz Dorota
Published: June 2020

This paper compares income distributions for the family types distinguished by the number of children. The primary contribution to the literature of the current paper was to provide evidence that between 2015 and 2016, when the child benefit Family 500+ program was implemented, there was a reduction in income inequality and poverty, especially for families with many children. The basis for the calculations was microdata from the Household Budget Survey conducted by Statistics Poland. It is the basic source of information on the revenues, expenditures, quantitative food consumption and other aspects of the living conditions of particular groups of the population. The data obtained from this survey allow for the analysis of different factors influencing income distribution and its inequality by means of selected income inequality measures: Gini index and the quintile and decile share ratios. To conduct poverty analysis, the head-count ratio, poverty gap and squared poverty gap indices were applied. The results of the analysis revealed noticeable changes in the income distribution of Polish households, which resulted in poverty reduction, especially for families with many children. In total, mean equivalent income increased by 127 PLN and poverty decreased by 1.2 percentage points. Approximately 160,000 households came out of poverty. The two-sample parametric tests for differences in means and proportions showed that in 2016, the means were significantly larger and poverty rates significantly smaller for all family types but the differences were larger for large families.
A Shadow-Test Approach to Adaptive Item Calibration
Authors: van der Linden Wim J. , Jiang Bingnan
Published: June 2020

A shadow-test approach to the calibration of field-test items embedded in adaptive testing is presented. The objective function used in the shadow-test model selects both the operational and field-test items adaptively using a Bayesian version of the criterion of <mml:math xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:mnf="http://cambridge.org/core/manifest" xmlns:cup="http://contentservices.cambridge.org" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:m="http://cambridge.org/core/metadata" xmlns:core="http://cambridge.org/core" xmlns:c="http://cambridge.org/core/content">Ds\documentclass[12pt]{minimal}
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\begin{document}$$D_{\mathrm{s}}$$\end{document}-optimality. The constraint set for the model can be used to hide the field-test items completely in the content of the test as well as to deal with such practical issues as random control of their exposure rates. The approach runs on efficient implementations of the Gibbs sampler for the real-time updating of the ability and field-test parameters. Optimal settings for the proposed algorithms were found and used to demonstrate item calibration with smaller than traditional sample sizes in runtimes fully comparable with conventional adaptive testing.
Uranium and neptunium retention mechanisms in Gallionella ferruginea/ferrihydrite systems for remediation purposes
Authors: Krawczyk-Bärsch Evelyn , Scheinost Andreas C. , Rossberg André , Müller Katharina , Bok Frank , Hallbeck Lotta , Lehrich Jana , Schmeide Katja
Published: June 2020

The ubiquitous β-Proteobacterium Gallionella ferruginea is known as stalk-forming, microaerophilic iron(II) oxidizer, which rapidly produces iron oxyhydroxide precipitates. Uranium and neptunium sorption on the resulting intermixes of G. ferruginea cells, stalks, extracellular exudates, and precipitated iron oxyhydroxides (BIOS) was compared to sorption to abiotically formed iron oxides and oxyhydroxides. The results show a high sorption capacity of BIOS towards radionuclides at circumneutral pH values with an apparent bulk distribution coefficient (Kd) of 1.23 × 104 L kg−1 for uranium and 3.07 × 105 L kg−1 for neptunium. The spectroscopic approach by X-ray absorption spectroscopy (XAS) and ATR FT-IR spectroscopy, which was applied on BIOS samples, showed the formation of inner-sphere complexes. The structural data obtained at the uranium LIII-edge and the neptunium LIII-edge indicate the formation of bidentate edge-sharing surface complexes, which are known as the main sorption species on abiotic ferrihydrite. Since the rate of iron precipitation in G. ferruginea-dominated systems is 60 times faster than in abiotic systems, more ferrihydrite will be available for immobilization processes of heavy metals and radionuclides in contaminated environments and even in the far-field of high-level nuclear waste repositories.
The reaction of cucumber to the introduction of ionic liquids into the soil
Authors: Biczak Robert , Pawłowska Barbara , Podsiadło Cezary , Śnioszek Martyna , Telesiński Arkadiusz
Published: June 2020

This paper presents the influence of two bromides, tetrabutylammonium and tetrabutylphosphonium, on the growth and development of cucumber seedlings. The tests were performed at two dates, i.e. 10 and 20 days, after the introduction of increasing amounts of ionic liquids (ILs) into the soil. The applied ILs showed phytotoxicity dependent mainly on the concentration of the substance, which is proved by the inhibition of the length of aboveground parts and their roots and the yield of cucumber fresh mass, from which EC50 values were calculated. The phytotoxicity symptoms were the result of oxidative stress, one of the manifestations of which was a decrease in assimilative pigments, linearly correlated with an increase in bromide concentration in the medium. The stress is also proven by the large increase in hydrogen peroxide, malondialdehyde and free proline in cucumber leaves. The reaction of this plant to oxidative stress was an increase in the activity of antioxidative enzymes such as catalase and peroxidase. As a result of statistical analysis, it was proved that all changes of biomarkers of phytotoxicity of examined ILs and oxidative stress indicators in cucumber seedlings depended more on the applied concentration of these salts than on the date of the study.
The Influence of Laparoscopic Sleeve Gastrectomy on Body Composition and Fat Distribution in Obese Caucasian Men and Women
Authors: Tałałaj Marek , Bogołowska-Stieblich Agata , Wąsowski Michał , Binda Artur , Jaworski Paweł , Wrzosek Małgorzata , Tarnowski Wiesław
Published: June 2020

Background

The aim of the study was to assess changes in body composition in patients subjected to laparoscopic sleeve gastrectomy (LSG).

Methods

Changes in body composition following LSG were determined in a group of 155 patients with obesity (117 women and 38 men), with dual-energy X-ray absorptiometry (DXA). Whole body fat mass (FM) and lean body mass (LBM) were determined, and abdominal fat mass (AbdF) was assessed within the region extending from the top of the pubic bone up to the line between 12th thoracic and 1st lumbar vertebras.

Results

Over the period of 12 months following LSG, body mass index decreased by 28.2 ± 9.0% (p < 0.001). The reduction of body weight by 35.4 ± 12.6 kg (p < 0.001) was the result of a decrease in FM by 23.9 ± 8.9 kg (p < 0.001) and LBM by 10.5 ± 3.8 kg (p < 0.001). AbdF decreased from 13.2 ± 3.1 to 8.2 ± 2.7 kg (p < 0.001), but abdominal fat to total fat mass ratio increased from 24.9 ± 4.7 to 28.0 ± 5.8% (p < 0.001). The loss of AbdF was more pronounced in men than in women. The rate of FM loss was attenuated with patients’ age.

Conclusions

Over the period of 12 months following LSG, the reduction of FM was more than twice as much as decrease of LBM. The loss of AbdF was slower than a loss of peripheral subcutaneous fat.
Analytic Eigenbranches in the Semi-classical Limit
Authors: Haller Stefan
Published: June 2020

We consider a one parameter family of Laplacians on a closed manifold and study the semi-classical limit of its analytically parametrized eigenvalues. Our results establish a vector valued analogue of a theorem for scalar Schrödinger operators on Euclidean space by Luc Hillairet which applies to geometric operators like Witten’s Laplacian on differential forms.
Brand experience manual: bridging the gap between brand strategy and customer experience
Authors: Motta-Filho Mauricy A.
Published: June 2020

The importance of customer experiences in developing strong brands is broadly acknowledged in the Branding literature. Yet, the divide between the functions managing the brand and those responsible for devising the interactions through which customers experience the brand persists. This paper aims to bridge the gap between Brand Strategy and Customer Experience by introducing the concept of the Brand Experience Manual. Throughpractice-based design research, this paper describes the development of a Brand Experience Manual over four iteration cycles. Throughout this process, this paper explores ways of conveying the experience proposition made by the brand, developing a framework for defining and a tool for communicating the Brand Experience Proposition to the teams responsible for the New Service Development. Additionally, this paper offers a theoretical basis for the advancement of acustomer experience-centric approach to Branding.
Danaher’s Ethical Behaviourism: An Adequate Guide to Assessing the Moral Status of a Robot?
Authors: Smids Jilles
Published: June 2020

This paper critically assesses John Danaher’s ‘ethical behaviourism’, a theory on how the moral status of robots should be determined. The basic idea of this theory is that a robot’s moral status is determined decisively on the basis of its observable behaviour. If it behaves sufficiently similar to some entity that has moral status, such as a human or an animal, then we should ascribe the same moral status to the robot as we do to this human or animal. The paper argues against ethical behaviourism by making four main points. First, it is argued that the strongest version of ethical behaviourism understands the theory as relying on inferences to the best explanation when inferring moral status. Second, as a consequence, ethical behaviourism cannot stick with merely looking at the robot’s behaviour, while remaining neutral with regard to the difficult question of which property grounds moral status. Third, not only behavioural evidence ought to play a role in inferring a robot’s moral status, but knowledge of the design process of the robot and of its designer’s intention ought to be taken into account as well. Fourth, knowledge of a robot’s ontology and how that relates to human biology often is epistemically relevant for inferring moral status as well. The paper closes with some concluding observations.
Investigating the use of an ensemble of evolutionary algorithms for letter identification in tremulous medieval handwriting
Authors: da Silva Ronnypetson Souza , Da Costa-Abreu Márjory , Smith Stephen
Published: June 2020

Ensemble classifiers are known for performing good generalization from simpler and less accurate classifiers. Ensembles have the ability to use the variety in classification patterns of the smaller classifiers in order to make better predictions. However, to create an ensemble it is necessary to determine how the component classifiers should be combined to generate the final predictions. One way to do this is to search different combinations of classifiers with evolutionary algorithms, which are largely employed when the objective is to find a structure that serves for some purpose. In this work, an investigation is carried about the use of ensembles obtained via evolutionary algorithm for identifying individual letters in tremulous medieval writing and to differentiate between scribes. The aim of this research is to use this process as the first step towards classifying the tremor type with more accuracy. The ensembles are obtained through evolutionary search of trees that aggregate the output of base classifiers, which are neural networks trained prior to the ensemble search. The misclassification patterns of the base classifiers are analysed in order to determine how much better an ensemble of those classifiers can be than its components. The best ensembles have their misclassification patterns compared to those of their component classifiers. The results obtained suggest interesting methods for letter (up to 96% accuracy) and user classification (up to 88% accuracy) in an offline scenario.
Marital goals: Circular value-based model and measurement
Authors: Czyżkowska Anna , Cieciuch Jan
Published: June 2020

The aim of the research presented in this article was to develop a comprehensive model and measurement of marital goals. The aim of Study 1 was to validate the initial model of marital goals according to Schwartz’s model of values (defined as general transsituational goals). The sample consisted of 684 participants (50% female), all of whom were either married or cohabiting couples aged between 25 and 60 years (M = 37.2;SD = 5.3). The obtained results led to a modification of our initial theoretical model. In the final version of the model, we distinguished eight types of marital goals located in a circular way around two basic dimensions that were similar but not identical to those of Schwartz’s model: (1) oneself versus other focus and (2) relationship commitment versus avoidance. We validated the model in Study 2 in another sample of 1268 participants (50% female) with married couples aged between 18 and 86 years (M = 47.2;SD = 16.1). The measurement model was confirmed through a confirmatory factor analysis; the circular structure was confirmed through multidimensional scaling; the validity of the distinguished goals was confirmed through correlational analyses with value priorities, and marital satisfaction.
Occupying the Fringes: The Struggles of Women in Artisanal and Small-Scale Gold Mining in Rural Ghana—Evidence from the Prestea–Huni Valley Municipality
Authors: Arthur-Holmes Francis , Abrefa Busia Kwaku
Published: June 2020

Across many mineral-rich developing countries, artisanal and small-scale mining (ASM) has been noted as a crucial socio-economic activity for most rural people. Over the past 2 decades, there has been growing participation of women in the ASM sector with extant studies examining why women participate in ASM, the roles they play and how their involvement enhances their socio-economic development. However, the socio-structural dynamics and gendered relations within ASM are poorly understood and underexplored despite the increasing participation of women in the sector. Based on field observations and interviews involving 49 women miners in the Prestea–Huni Valley Municipality of Ghana, this paper discusses the on-site challenges of women in ASM through multiple standpoint and African feminism theoretical perspectives. It also examines how understanding the struggles of women can reduce their work-related risks and promote gender-sensitive policies for rural women’s empowerment in ASM. The study finds that the struggles of working women in ASM involve cultural marginalisation and gendered work patterns, poor working environment, poor work support services for women with children, lack of legal and economic rights, and inter-ethnic discrimination by employers. We argue that policymakers, relevant stakeholders, and the government through the district assemblies should collaborate with small-scale mining employers to enhance gender-sensitive on-site regulatory policies, ensure safe working environments for workers, and provide locally appropriate work support services for women in ASM. We further argue that, government and regulatory institutions need to promote gender mainstreaming for ‘inclusion of women’ in the management structure at mine sites and also the extraction and processing stages of ASM.