bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing changes in the quality of quantitative health educations research: a perspective from communities of practice
Authors: Wright Katherine M. , Gruppen Larry D. , Kuo Kevin W. , Muzyk Andrew , Nahmias Jeffry , Reed Darcy A. , Sandhu Gurjit , Shelgikar Anita V. , Stojan Jennifer N. , Uchida Toshiko L. , Wallihan Rebecca , Hurtubise Larry
Published: April 2022

Background

As a community of practice (CoP), medical education depends on its research literature to communicate new knowledge, examine alternative perspectives, and share methodological innovations. As a key route of communication, the medical education CoP must be concerned about the rigor and validity of its research literature, but prior studies have suggested the need to improve medical education research quality. Of concern in the present study is the question of how responsive the medical education research literature is to changes in the CoP. We examine the nature and extent of changes in the quality of medical education research over a decade, using a widely cited study of research quality in the medical education research literature as a benchmark to compare more recent quality indicators.

Methods

A bibliometric analysis was conducted to examine the methodologic quality of quantitative medical education research studies published in 13 selected journals from September 2013 to December 2014. Quality scores were calculated for 482 medical education studies using a 10-item Medical Education Research Study Quality Instrument (MERSQI) that has demonstrated strong validity evidence. These data were compared with data from the original study for the same journals in the period September 2002 to December 2003. Eleven investigators representing 6 academic medical centers reviewed and scored the research studies that met inclusion and exclusion criteria. Primary outcome measures include MERSQI quality indicators for 6 domains: study design, sampling, type of data, validity, data analysis, and outcomes.

Results

There were statistically significant improvements in four sub-domain measures: study design, type of data, validity and outcomes. There were no changes in sampling quality or the appropriateness of data analysis methods. There was a small but significant increase in the use of patient outcomes in these studies.

Conclusions

Overall, we judge this as equivocal evidence for the responsiveness of the research literature to changes in the medical education CoP. This study identified areas of strength as well as opportunities for continued development of medical education research.
Factors impacting the access and use of formal health and social services by caregivers of stroke survivors: an interpretive description study
Authors: Garnett Anna , Ploeg Jenny , Markle-Reid Maureen , Strachan Patricia H.
Published: April 2022

Background

Evidence has shown that family and friend caregivers of stroke survivors are significantly and negatively impacted by caregiving. The negative effects of caregiving may persist over time suggesting that caregivers might benefit from ongoing engagement with supportive services. However, little is known about caregivers’ use of formally funded health and social services, or the factors influencing their access to and use of these services. The aim of this study is to increase understanding of the factors that influence stroke caregivers’ access and use of formal health and social services, from the perspective of stroke caregivers and healthcare providers.

Methods

A qualitative study was conducted with stroke caregivers and health providers in Ontario, Canada using interpretive description. In-depth interviews were conducted with caregivers of survivors who experienced a stroke between six months to five years previous and healthcare providers who support caregivers and stroke survivors. All participants provided written informed consent. Interview data were analyzed using constant comparison to identify codes and develop key thematic constructs.

Results

A total of 40 interviews were conducted with 22 stroke caregivers at an average 30-months post-stroke and 18 health providers. Factors that influenced stroke caregivers’ access and use of services included: finances and transportation; challenges caregivers faced in caring for their health; trust that they could leave their family member and trust in health providers; limited information pertaining to services and a lack of suitable services; and the response of their social networks to their caregiving situation.

Conclusion

Stroke caregivers experience significant challenges in accessing and using formal health and social services. These challenges could be addressed by increasing availability of subsidized community-based supports such as respite and counselling tailored to meet the ongoing needs of caregivers. Systemic change is needed by the health system that readily includes and supports caregivers throughout the stroke recovery continuum, particularly in the community setting.
Expression status of p53 and organic cation transporter 1 is correlated with poor response to preoperative chemotherapy in esophageal squamous cell carcinoma
Authors: Izutsu Masahiro , Domoto Takanori , Kamoshida Shingo , Ohsaki Hiroyuki , Matsuoka Hiroshi , Umeki Yusuke , Shiogama Kazuya , Hirayama Masaya , Suda Koichi , Uyama Ichiro
Published: April 2022

Background

Esophageal squamous cell carcinoma (ESCC) is a highly malignant neoplasm. DNA-damaging drugs, such as cisplatin (CDDP) and 5-fluorouracil (5-FU), are most frequently used in preoperative chemotherapy for ESCC. However, the response to preoperative chemotherapy varies among patients. p53, encoded by TP53, participates in apoptotic pathways following chemotherapy with DNA-damaging drugs, and mutation of TP53 contributes to chemoresistance. Organic cation transporter 1 (OCT1) participates in the uptake of CDDP, and its reduced expression is associated with CDDP resistance. The aim of this study was to evaluate the predictive impact of the expression status of p53 and OCT1 in response to preoperative chemotherapy in ESCC.

Methods

We retrospectively assessed 66 ESCC patients who received preoperative chemotherapy with CDDP/5-FU (CF) or docetaxel/CDDP/5-FU (DCF). p53 and OCT1 expression in pretreatment biopsy specimens was immunohistochemically determined and correlated with histological response to preoperative chemotherapy.

Results

p53 with wild-type (p53WT-ex) and mutant-type (p53MT-ex) expression patterns was identified in 40.9% and 59.1% of patients, respectively. High expression of OCT1 (OCT1High) was detected in 45.5%, and the remaining 54.5% showed low expression (OCT1Low). In a univariate analysis of the entire cohort, p53MT-ex was significantly correlated with poor response (P = 0.026), whereas OCT1Low showed marginal significance (P = 0.091). In a combined analysis, tumors with either p53MT-ex or OCT1Low showed a significant correlation with poor response compared with tumors with both p53WT-ex and OCT1High (P < 0.001). The sensitivity, specificity, and accuracy of combined p53/OCT1 were 93.9%, 47.1%, and 81.8%, respectively. Multivariate analysis identified p53 (P = 0.017), OCT1 (P = 0.032), and combined p53/OCT1 (P < 0.001) as independent predictors of histological response. When samples were stratified according to chemotherapy regimen in the univariate analysis, combined p53/OCT1 was the only significant factor for poor response in the CF (P = 0.011) and DCF (P = 0.021) groups, whereas p53 showed no statistical significance.

Conclusions

Our results suggest that either p53MT-ex or OCT1Low expression in pretreatment biopsy specimens may be a potential predictor of poor response to preoperative chemotherapy with the CF-based regimens in ESCC, although the specificity needs to be improved.
Proteolysis dependent cell cycle regulation in Caulobacter crescentus
Authors: Fatima Nida I , Fazili Khalid Majid , Bhat Nowsheen Hamid
Published: April 2022

Caulobacter crescentus, a Gram-negative alpha-proteobacterium, has surfaced as a powerful model system for unraveling molecular networks that control the bacterial cell cycle. A straightforward synchronization protocol and existence of many well-defined developmental markers has allowed the identification of various molecular circuits that control the underlying differentiation processes executed at the level of transcription, translation, protein localization and dynamic proteolysis. The oligomeric AAA+ protease ClpXP is a well-characterized example of an enzyme that exerts post-translational control over a number of pathways. Also, the proteolytic pathways of its candidate proteins are reported to play significant roles in regulating cell cycle and protein quality control. A detailed evaluation of the impact of its proteolysis on various regulatory networks of the cell has uncovered various significant cellular roles of this protease in C. crescentus. A deeper insight into the effects of regulatory proteolysis with emphasis on cell cycle progression could shed light on how cells respond to environmental cues and implement developmental switches. Perturbation of this network of molecular machines is also associated with diseases such as bacterial infections. Thus, research holds immense implications in clinical translation and health, representing a promising area for clinical advances in the diagnosis, therapeutics and prognosis.
Evaluating the impact of possible interobserver variability in CBCT-based soft-tissue matching using TCP/NTCP models for prostate cancer radiotherapy
Authors: Zhang Xiangbin , Wang Xin , Li Xiaoyu , Zhou Li , Nie Shihong , Li Changhu , Wang Xuetao , Dai Guyu , Deng Zhonghua , Zhong Renming
Published: April 2022

Background

Prostate alignment is subject to interobserver variability in cone-beam CT (CBCT)-based soft-tissue matching. This study aims to analyze the impact of possible interobserver variability in CBCT-based soft-tissue matching for prostate cancer radiotherapy.

Methods

Retrospective data, consisting of 156 CBCT images from twelve prostate cancer patients with elective nodal irradiation were analyzed in this study. To simulate possible interobserver variability, couch shifts of 2 mm relative to the resulting patient position of prostate alignment were assumed as potential patient positions (27 possibilities). For each CBCT, the doses of the potential patient positions were re-calculated using deformable image registration-based synthetic CT. The impact of the simulated interobserver variability was evaluated using tumor control probabilities (TCPs) and normal tissue complication probabilities (NTCPs).

Results

No significant differences in TCPs were found between prostate alignment and potential patient positions (0.944 ± 0.003 vs 0.945 ± 0.003, P = 0.117). The average NTCPs of the rectum ranged from 5.16 to 7.29 (%) among the potential patient positions and were highly influenced by the couch shift in the anterior–posterior direction. In contrast, the average NTCPs of the bladder ranged from 0.75 to 1.12 (%) among the potential patient positions and were relatively negligible.

Conclusions

The NTCPs of the rectum, rather than the TCPs of the target, were highly influenced by the interobserver variability in CBCT-based soft-tissue matching. This study provides a theoretical explanation for daily CBCT-based image guidance and the prostate-rectum interface matching procedure.

Trial registration: Not applicable.
The association between lymphocyte-monocyte ratio and postoperative acute kidney injury in patients with acute type A aortic dissection
Authors: Chen Wenxiu , Song Xiaochun , Hong Liang , Xu Huan , Qian Yan , Zhang Wenhao , Sun Jiakui , Shen Xiao , Liu Ying , Wang Xiang , Shi Qiankun , Liu Han , Mu Xinwei , Zhang Cui
Published: April 2022

Background

The aim of this study was to investigate the relationship between baseline lymphocyte-monocyte ratio (LMR) and postoperative acute kidney injury (AKI) in patients with acute type A aortic dissection (ATAAD).

Methods

ATAAD patients undergoing surgery in Nanjing First Hospital were enrolled from January 2019 to April 2021. Lymphocyte and monocyte were measured on admission. Multivariable logistic regression analyses were performed to explore the relationship between LMR and postoperative AKI. We also used receiver operating characteristic (ROC), net reclassification index (NRI) and integrated discrimination improvement (IDI) analyses to assess the predictive ability of LMR.

Results

Among the 159 recruited patients, 47 (29.6%) were diagnosed with AKI. Univariate logistic regression analysis indicated that ATAAD patients with higher levels of LMR were prone to have lower risk to develop AKI (odds ratio [OR], 0.493; 95% confidence interval [CI] 0.284–0.650, P = 0.001). After adjustment for the potential confounders, LMR remained an independent related factor with postoperative AKI (OR 0.527; 95% CI 0.327–0.815, P = 0.006). The cutoff value for LMR to predict AKI was determined to be 2.67 in the ROC curve analysis (area under curve: 0.719). NRI and IDI further confirmed the predictive capability of LMR in postoperative AKI.

Conclusion

Elevated baseline LMR levels were independently associated with lower risk of postoperative AKI in ATAAD patients.
Safety and effectiveness of taliglucerase alfa in patients with Gaucher disease: an interim analysis of real-world data from a multinational drug registry (TALIAS)
Authors: Titievsky Lina , Schuster Tilman , Wang Ronnie , Younus Muhammad , Palladino Andrew , Quazi Kabir , Wajnrajch Michael P. , Hernandez Betina , Becker Pamela S. , Weinreb Neal J. , Chambers Christina , Mansfield Roy , Taylor Louise , Tseng Li-Jung , Kaplan Paige
Published: April 2022

Background

Limited real-world data from routine clinical care are available on the safety and effectiveness of treatment with taliglucerase alfa in patients with Gaucher disease (GD).

Methods

Taliglucerase Alfa Surveillance (TALIAS), a multinational prospective Drug Registry of patients with GD, was established to evaluate the long-term safety (primary objective) and effectiveness (secondary objective) of taliglucerase alfa. We present an interim analysis of the data from the Drug Registry collected over the 5-year period from September 2013 to January 2019.

Results

A total of 106 patients with GD (15.1% children aged < 18 years; 53.8% females) treated with taliglucerase alfa have been enrolled in the Drug Registry, as of January 7, 2019. The median duration of follow-up was 795 days with quartiles (Q1, Q3) of 567 and 994 days. Fifty-three patients (50.0%) were from Israel, 28 (26.4%) were from the United States, and 25 (23.6%) were from Albania. At the time of enrollment, most patients (87.7%) had received prior enzyme replacement therapy (ERT). Thirty-nine of the 106 patients had treatment-emergent adverse events (AEs). Twelve of the 106 patients experienced serious AEs; two patients experienced four treatment-related serious AEs. Four patients died, although none of the deaths was considered to be related to taliglucerase alfa treatment by the treating physicians. Nine patients discontinued from the study, including the four who died. At baseline, patients with prior ERT had a higher mean hemoglobin concentration and platelet counts than treatment-naïve patients, likely reflecting the therapeutic effects of prior treatments. During follow-up, the hemoglobin concentration and platelet counts increased in the treatment-naïve patients and remained relatively constant or increased slightly in patients with prior ERT. Spleen and liver volumes decreased in treatment-naïve patients.

Conclusions

The interim data showed no new or emergent safety signals. The overall interim data are consistent with the clinical program experience and known safety and effectiveness profile of taliglucerase alfa.
How we teach children with asthma to use their inhaler: a scoping review
Authors: McCrossan Patrick , Mallon Orla , Shields Michael D. , Russell Catherine , Kennedy Lesley , O’Donoghue Dara
Published: April 2022

Background

One reason that asthma remains poorly controlled in children is poor inhaler technique. Guidelines recommend checking inhaler technique at each clinical visit. However, they do not specify how best to train children to mastery of correct inhaler technique. Many children are simply shown how to use inhalers which results in less than 50% with correct inhaler technique. The aim of this scoping review is to explore published literature on teaching methods used to train children to master correct inhaler technique.

Methods

We searched (from inception onwards): Medline, Embase, Scopus, Web of Science, CINAHL and the Cochrane library. We included quantitative studies, (e.g. randomised controlled trials, cohort studies and case-control studies), published from 1956 to present, on teaching inhaler technique to children with asthma. Data was extracted onto a data charting table to create a descriptive summary of the results. Data was then synthesised with descriptive statistics and visual mapping.

Results

Thirty-three papers were identified for full text analysis. Educational interventions were found to be taking place in a variety of clinical areas and by a range of healthcare professional disciplines. ‘Brief-Instruction’ and ‘Teach-Back’ were identified as two primary methods of providing inhaler technique training in the majority of papers. Secondary themes identified were; use of written instruction, physical demonstration, video demonstrations and/or use of inhaler devices to augment inhaler technique training.

Conclusion

There are a variety of means by which inhaler technique has been taught to children. These methods are likely applicable to all inhaler types and often involve some form of physical demonstration. Children of all ages can be trained to use their inhaler correctly and by a range of healthcare professionals. We have not analysed the effectiveness of these different interventions, but have described what has been trialled before in an attempt to focus our attentions on what may potentially work best. The majority of these methods can be dichotomised to either ‘Brief-Intervention’ or ‘Teach-Back’. Based on our analysis of this scoping review, we consider the following as areas for future research; how many times does a given intervention have to be done in order to have the desired effect? For what duration does the intervention need to continue to have a long-lasting effect? And, what is the best outcome measure for inhaler technique?.

Trial registration

Systematic review registration: Open Science Framework (osf.io/n7kcw).
De novo mutation of CYBB gene in a boy presenting as intra-abdominal infection of Burkholderia contaminans: a case report
Authors: Zhao Qianqian , Yin Jing , Ma Jijun , Liu Xiaoxue , Wu Jiawen , Li Chongwei
Published: April 2022

Background

Chronic granulomatous disease (CGD) is an inborn error of immunity. It is characterized by recurrent bacterial or fungal infections, including infections by Burkholderia species. This is due to respiratory burst dysfunction of phagocytes. Currently, there is no report on Burkholderia contaminans (B. Contaminans) infection in children with CGD.

Case presentation

We present a previously healthy, 17-month-old Chinese boy infected with B. Contaminans in the intra-abdominal regions. Immunological screening, including assessment of cellular immunity and humoral immunity did not yield conclusive results. The level of nicotinamide adenine dinucleotide phosphatase (NADPH) activity was decreased and whole-exome sequencing identified a de novo mutation in the CYBB gene.

Conclusions

For specific pathogens such as B. Contaminans, immune assessment should be carried out even if there is no positive medical history or specificity in basic immunity screening.
Targeting SHP2 phosphatase in breast cancer overcomes RTK-mediated resistance to PI3K inhibitors
Authors: Heynen Guus J. J. E. , Lisek Kamil , Vogel Regina , Wulf-Goldenberg Annika , Alcaniz Joshua , Montaudon Elodie , Marangoni Elisabetta , Birchmeier Walter
Published: April 2022

Background

PI3K signaling is frequently activated in breast cancer and is targeted by PI3K inhibitors. However, resistance of tumor cells to PI3K inhibition, often mediated by activated receptor tyrosine kinases, is commonly observed and reduces the potency of PI3K inhibitors. Therefore, new treatment strategies to overcome resistance to PI3K inhibitors are urgently needed to boost their efficacy. The phosphatase SHP2, which plays a crucial role in mediating signal transduction between receptor tyrosine kinases and both the PI3K and MAPK pathways, is a potential target for combination treatment.

Methods

We tested combinations of PI3K and SHP2 inhibitors in several experimental breast cancer models that are resistant to PI3K inhibition. Using cell culturing, biochemical and genetic approaches, we evaluated tumor cell proliferation and signaling output in cells treated with PI3K and SHP2 inhibitors.

Results

Combination treatment with PI3K and SHP2 inhibitors counteracted both acquired and intrinsic breast cancer cell resistance to PI3K inhibition that is mediated by activated receptor tyrosine kinases. Dual PI3K and SHP2 inhibition blocked proliferation and led to sustained inactivation of PI3K and MAPK signaling, where resistant cells rapidly re-activated these pathways upon PI3K inhibitor monotreatment. In addition, we demonstrate that overexpression of SHP2 induced resistance to PI3K inhibition, and that SHP2 was frequently activated during the development of PI3K inhibitor resistance after prolonged treatment of sensitive cells.

Conclusions

Our results highlight the importance of SHP2 as a player in resistance to PI3K inhibitors. Combination treatment with PI3K and SHP2 inhibitors could pave the way for significant improvements in therapies for breast cancer.
Application of magnetic nanoparticles in cell therapy
Authors: Chen Yuling , Hou Shike
Published: April 2022

Fe3O4 magnetic nanoparticles (MNPs) are biomedical materials that have been approved by the FDA. To date, MNPs have been developed rapidly in nanomedicine and are of great significance. Stem cells and secretory vesicles can be used for tissue regeneration and repair. In cell therapy, MNPs which interact with external magnetic field are introduced to achieve the purpose of cell directional enrichment, while MRI to monitor cell distribution and drug delivery. This paper reviews the size optimization, response in external magnetic field and biomedical application of MNPs in cell therapy and provides a comprehensive view.
The therapeutic potential of stem cell-derived exosomes in the ulcerative colitis and colorectal cancer
Authors: Guo Gang , Tan Zhaobang , Liu Yaping , Shi Feiyu , She Junjun
Published: April 2022

Background

Mesenchymal stem cells (MSCs) therapy is a novel treatment strategy for cancer and a wide range of diseases with an excessive immune response such as ulcerative colitis (UC), due to its powerful immunomodulatory properties and its capacity for tissue regeneration and repair. One of the promising therapeutic options can focus on MSC-secreted exosomes (MSC-Exo), which have been identified as a type of paracrine interaction. In light of a wide variety of recent experimental studies, the present review aims to seek the recent research advances of therapies based on the MSC-Exo for treating UC and colorectal cancer (CRC).

Methods

A systematic literature search in MEDLINE, Scopus, and Google Scholar was performed from inception to December 2021 using the terms [(“colorectal cancer” OR “bowel cancer” OR “colon cancer” OR “rectal cancer”) AND (exosome) AND (stem cell) AND (“inflammatory bowel disease” OR “Crohn's disease” OR “colitis”)] in titles and abstracts.

Findings

Exosomes derived from various sources of MSCs, including human umbilical cord-derived MSCs (hUC-MSCs), human adipose-derived MSCs (hAD-MSCs), human bone marrow-derived MSCs (hBM-MSCs), and olfactory ecto-MSCs (OE-MSCs), have shown the protective role against UC and CRC. Exosomes from hUC-MSCs, hBM-MSCs, AD-MSCs, and OE-MSCs have been found to ameliorate the experimental UC through suppressing inflammatory cells including macrophages, Th1/Th17 cells, reducing the expression of proinflammatory cytokines, as well as inducing the anti-inflammatory function of Treg and Th2 cells and enhancing the expression of anti-inflammatory cytokines. In addition, hBM-MSC-Exo and hUC-MSC-Exo containing tumor-suppressive miRs (miR-3940-5p/miR-22-3p/miR‐16‐5p) have been shown to suppress proliferation, migration, and invasion of CRC cells via regulation of RAP2B/PI3K/AKT signaling pathway and ITGA2/ITGA6.

Key messages

The MSC-Exo can exert beneficial effects on UC and CRC through two different mechanisms including modulating immune responses and inducing anti-tumor responses, respectively.
Enhancement of pacing function by HCN4 overexpression in human pluripotent stem cell-derived cardiomyocytes
Authors: Saito Yukihiro , Nakamura Kazufumi , Yoshida Masashi , Sugiyama Hiroki , Akagi Satoshi , Miyoshi Toru , Morita Hiroshi , Ito Hiroshi
Published: April 2022

Background

The number of patients with bradyarrhythmia and the number of patients with cardiac pacemakers are increasing with the aging population and the increase in the number of patients with heart diseases. Some patients in whom a cardiac pacemaker has been implanted experience problems such as pacemaker infection and inconvenience due to electromagnetic interference. We have reported that overexpression of HCN channels producing a pacemaker current in mouse embryonic stem cell-derived cardiomyocytes showed enhanced pacing function in vitro and in vivo. The aim of this study was to determine whether HCN4 overexpression in human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) can strengthen the pacing function of the cells.

Methods

Human HCN4 was transduced in the AAVS1 locus of human induced pluripotent stem cells by nucleofection and HCN4-overexpressing iPSC-CMs were generated. Gene expression profiles, frequencies of spontaneous contraction and pacing abilities of HCN4-overexpressing and non-overexpressing iPSC-CMs in vitro were compared.

Results

HCN4-overexpressing iPSC-CMs showed higher spontaneous contraction rates than those of non-overexpressing iPSC-CMs. They responded to an HCN channel blocker and β adrenergic stimulation. The pacing rates against parent iPSC line-derived cardiomyocytes were also higher in HCN4-overexpressing iPSC-CMs than in non-overexpressing iPSC-CMs.

Conclusions

Overexpression of HCN4 showed enhancement of If current, spontaneous firing and pacing function in iPSC-CMs. These data suggest this transgenic cell line may be useful as a cardiac pacemaker.
Time accurate solution to Benjamin–Bona–Mahony–Burgers equation via Taylor–Boubaker series scheme
Authors: Izadi Mohammad , Samei Mohammad Esmael
Published: April 2022

The object of this paper is to develop an accurate combined spectral collocation approach to numerically solve the generalized nonlinear Benjamin–Bona–Mahony–Burgers equation. The first stage is devoted to discretization in time, which is carried out with the aid of the well-known Taylor series expansions. Then the spectral collocation procedure based on the Boubaker polynomials is applied for the resulting discretized spatial operator in each time step. A detailed error analysis of the presented technique is carried out with regard to the space variable. The advantages of the hybrid technique are shown via performing several simulations through four test examples. Comparisons between our numerical results and the outcomes of some existing schemes indicate that the proposed technique is not only simple and easy-to-implement, but also sufficiently accurate using a moderate number of bases and a large time step.
Acquisition repeatability of MRI radiomics features in the head and neck: a dual-3D-sequence multi-scan study
Authors: Xue Cindy , Yuan Jing , Zhou Yihang , Wong Oi Lei , Cheung Kin Yin , Yu Siu Ki
Published: April 2022

Radiomics has increasingly been investigated as a potential biomarker in quantitative imaging to facilitate personalized diagnosis and treatment of head and neck cancer (HNC), a group of malignancies associated with high heterogeneity. However, the feature reliability of radiomics is a major obstacle to its broad validity and generality in application to the highly heterogeneous head and neck (HN) tissues. In particular, feature repeatability of radiomics in magnetic resonance imaging (MRI) acquisition, which is considered a crucial confounding factor of radiomics feature reliability, is still sparsely investigated. This study prospectively investigated the acquisition repeatability of 93 MRI radiomics features in ten HN tissues of 15 healthy volunteers, aiming for potential magnetic resonance-guided radiotherapy (MRgRT) treatment of HNC. Each subject underwent four MRI acquisitions with MRgRT treatment position and immobilization using two pulse sequences of 3D T1-weighed turbo spin-echo and 3D T2-weighed turbo spin-echo on a 1.5 T MRI simulator. The repeatability of radiomics feature acquisition was evaluated in terms of the intraclass correlation coefficient (ICC), whereas within-subject acquisition variability was evaluated in terms of the coefficient of variation (CV). The results showed that MRI radiomics features exhibited heterogeneous acquisition variability and uncertainty dependent on feature types, tissues, and pulse sequences. Only a small fraction of features showed excellent acquisition repeatability (ICC > 0.9) and low within-subject variability. Multiple MRI scans improved the accuracy and confidence of the identification of reliable features concerning MRI acquisition compared to simple test-retest repeated scans. This study contributes to the literature on the reliability of radiomics features with respect to MRI acquisition and the selection of reliable radiomics features for use in modeling in future HNC MRgRT applications.
Quasi-linear analysis of dispersion relation preservation for nonlinear schemes
Authors: Xu Fengyuan , Yan Pan , Li Qin , You Yancheng
Published: April 2022

In numerical simulations of complex flows with discontinuities, it is necessary to use nonlinear schemes. The spectrum of the scheme used has a significant impact on the resolution and stability of the computation. Based on the approximate dispersion relation method, we combine the corresponding spectral property with the dispersion relation preservation proposed by De and Eswaran (J Comput Phys 218:398–416, 2006) and propose a quasi-linear dispersion relation preservation (QL-GRP) analysis method, through which the group velocity of the nonlinear scheme can be determined. In particular, we derive the group velocity property when a high-order Runge–Kutta scheme is used and compare the performance of different time schemes with QL-GRP. The rationality of the QL-GRP method is verified by a numerical simulation and the discrete Fourier transform method. To further evaluate the performance of a nonlinear scheme in finding the group velocity, new hyperbolic equations are designed. The validity of QL-GRP and the group velocity preservation of several schemes are investigated using two examples of the equation for one-dimensional wave propagation and the new hyperbolic equations. The results show that the QL-GRP method integrated with high-order time schemes can determine the group velocity for nonlinear schemes and evaluate their performance reasonably and efficiently.
The role of the underburden at Elgin Franklin in the understanding of the overburden 4D signal
Authors: Barens Leon , Vidal-Gilbert Sandrine , Cruickshank Chris
Published: April 2022

Elgin, Franklin, and West Franklin are high-pressure high-temperature fields located in the Central North Sea. The fields share a similar reservoir and overburden geology. During the life of the fields, they have undergone a similar depletion over time. However, each field shows a different 4D behavior in the overburden. The 4D signal on Elgin is the strongest and is located away from the wells. The Franklin 4D signal is in line with expectation as the strongest signal close to the wells. On West Franklin, the 4D signal is small and barely distinguishable from noise. To explain the differences in 4D signal between the fields, a detailed underburden salt interpretation is performed. The differences in underburden between Elgin (thick with an abundance of salt) and West Franklin (marginal underburden with proximal salt) show a strong correlation with the 4D signals of the overburden. The renewed salt interpretation is used to update a vintage geomechanical model, from which strains and stresses are computed. During the stress initialization of the geomechanical model, the underlying salt (thick sheet or salt weld) creates stress perturbations on the salt/rock interface. When the reservoir compaction is simulated, the 3D model simulates the vertical stretches differently in the overburden for the fields. The stretching varies according to the underburden thickness and presence of salt below the underburden. The results of the geomechanical modeling help explain the differences observed in the overburden 4D signal of the fields.
Obesity-associated Blunted Subcutaneous Adipose Tissue Blood Flow After Meal Improves After Bariatric Surgery
Authors: Saari Teemu , Koffert Jukka , Honka Henri , Kauhanen Saila , U-Din Mueez , Wierup Nils , Lindqvist Andreas , Groop Leif , Virtanen Kirsi A , Nuutila Pirjo
Published: April 2022

Context

Glucose-dependent insulinotropic peptide (GIP) and meal ingestion increase subcutaneous adipose tissue (SAT) perfusion in healthy individuals. The effects of GIP and a meal on visceral adipose tissue (VAT) perfusion are unclear.

Objective

Our aim was to investigate the effects of meal and GIP on VAT and SAT perfusion in obese individuals with type 2 diabetes mellitus (T2DM) before and after bariatric surgery.

Methods

We recruited 10 obese individuals with T2DM scheduled for bariatric surgery and 10 control individuals. Participants were studied under 2 stimulations: meal ingestion and GIP infusion. SAT and VAT perfusion was measured using 15O-H2O positron emission tomography–magnetic resonance imaging at 3 time points: baseline, 20 minutes, and 50 minutes after the start of stimulation. Obese individuals were studied before and after bariatric surgery.

Results

Before bariatric surgery the responses of SAT perfusion to meal (P = .04) and GIP-infusion (P = .002) were blunted in the obese participants compared to controls. VAT perfusion response did not differ between obese and control individuals after a meal or GIP infusion. After bariatric surgery SAT perfusion response to a meal was similar to that of controls. SAT perfusion response to GIP administration remained lower in the operated-on than control participants. There was no change in VAT perfusion response after bariatric surgery.

Conclusion

The vasodilating effects of GIP and meal are blunted in SAT but not in VAT in obese individuals with T2DM. Bariatric surgery improves the effects of a meal on SAT perfusion, but not the effects of GIP. Postprandial increase in SAT perfusion after bariatric surgery seems to be regulated in a GIP-independent manner.
Epic Humor: Elpidio Valdés and the Mythopoetics of Populist Laughter
Authors: Morales-Franceschini Éric
Published: April 2022

Whether emplotted as epic or as tragedy, the tales told about a nation’s revolutionary past do not tend to elicit laughter as much as awe and solemnity. This is the case with Cuba’s national epic, the story of its nineteenth-century wars for independence (1868–98)—the story of Cuba Libre. This essay analyzes how the animated cartoon shorts and film series Elpidio Valdés (1974–2003) comically inflects the story of Cuba Libre with ridiculing laughter and choteo (folk humor). The series puts forth both a hero more akin to a populist trickster than a Spartan and a revolutionary war more akin to carnivalesque drama than to the Homeric epic. In so doing, it subtly critiques the didactic and panegyric rhetoric that has shrouded the national (as well as the socialist) epic and, in its stead, offers a jocular and fallible revolutionary subject in a more participatory and less austere epic.
Entry Barriers, Idiosyncratic Distortions, and the Firm Size Distribution
Authors: Fattal-Jaef Roberto N.
Published: April 2022

This paper studies the interaction between barriers to firm entry and distortions to allocative efficiency in a standard model of firm dynamics. We derive a strategy to infer entry barriers based on cross-country differences in the firm size distribution and idiosyncratic distortions. The inferred barriers resemble regulation-based indicators in advanced economies but are substantially higher in middle- and low-income countries. Regulation-based indicators cannot account for cross-country differences in average firm size and underestimate the aggregate productivity gains associated with their removal by up to 8 percent on average. (JEL D21, D24, H25, L11, L60)
Editorial
Authors: Σοφός Αλιβίζος (Λοΐζος) , ΣΙΑΚΑΣ Σπύρος
Published: April 2022

Το παρόν τεύχος είναι αφιερωμένο στην εφαρμοσμένη αξιοποίηση βίντεο στην εκπαίδευση, στη βάση της διαθεματικής προσέγγισης ενός κεντρικού θέματος και της διεπιστημονικής ανάδειξης εννοιών  από γειτονικές επιστημονικές περιοχές. Στόχος του ειδικού τεύχους είναι να ενθαρρύνει τους εκπαιδευτικούς να δημιουργήσουν βίντεο με εκπαιδευτικό περιεχόμενο και να τα αξιοποιήσουν στη διδασκαλία τους ως διευρυμένα περιβάλλοντα εργασίας και μάθησης.

Όταν μιλάμε για αξιοποίηση βίντεο στην εκπαιδευτική διαδικασία εστιάζουμε σε δύο βασικές διαστάσεις: α) την απόκτηση βασικών γνώσεων και δεξιοτήτων για τη δημιουργία ενός βίντεο και β) την εφαρμογή γνώσεων και δεξιοτήτων για την παραγωγή εκπαιδευτικού υλικού, τόσο για τη δια ζώσης όσο και για την εξ αποστάσεως εκπαίδευση.

Κάθε ένα από τα άρθρα που παρουσιάζεται ακολούθως περιέχει και τις δύο αυτές διαστάσεις και αποτυπώνει τόσο τη φιλοσοφία, τη μεθοδολογία δημιουργίας του βίντεο όσο και την τεκμηρίωση των εκπαιδευτικών δραστηριοτήτων που έχουν παραχθεί.

Σε αυτό το τεύχος, δημοσιεύονται συνολικά 9 άρθρα.  Αυτά χωρίζονται σε τρεις κατηγορίες α) τα επιμορφωτικά (4 άρθρα), β) τα ιστορικά (3 άρθρα) και γ) τα κοινωνικά (1 άρθρο). Επιπλέον παρουσιάζεται ακόμα ένα άρθρο που ανήκει στην κατηγόρια της μυθοπλαστικής ταινίας.

Το πρώτο επιμορφωτικό ντοκιμαντέρ με τίτλο «Δεν πετάμε, ανακυκλώνουμε!»,  αναφέρεται σε θέματα «Περιβαλλοντικής Εκπαίδευσης» όπως στην αποσαφήνιση της έννοιας της ανακύκλωσης, εστιαζόμενη στο σύγχρονο πρόβλημα της ρύπανσης των πόλεων με σκουπίδια. Το δεύτερο με τίτλο «Ζωή χωρίς εξάρτηση» στοχεύει στην ενημέρωση των μαθητών σε θέματα που αφορούν την εξάρτηση από τη χρήση ναρκωτικών ουσιών  και μεθόδους για την πρόληψη αυτού. Στο τρίτο με τίτλο «Η διαδρομή του βιβλίου: από το συγγραφέα στον αναγνώστη» περιγράφεται η διαδικασία δημιουργίας ενός βιβλίου και τα επιμέρους στάδια που αυτή περιλαμβάνει. Στο τέταρτο και τελευταίο επιμορφωτικό ντοκιμαντέρ με τίτλο «Έλληνες ζωγράφοι της Σχολής του Μονάχου» παρουσιάζονται οι κύριοι εκπρόσωποι της Σχολής του Μονάχου και τα έργα τους που φιλοξενούνται στην Εθνική πινακοθήκη Αθηνών.

Στο πρώτο ιστορικό ντοκιμαντέρ με τίτλο «Achaia Clauss, το Οινόκαστρο της Μαυροδάφνης» παρουσιάζεται  η ιστορία της πρώτης ελληνικής οινοποιίας. Στο δεύτερο με τίτλο «Το Αιγαίο στις φλόγες» γίνεται αναφορά στις μεγαλύτερες και ηρωικότερες ναυμαχίες του Αιγαίου πελάγους. Στο τρίτο με τίτλο «Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών - ιστορία πίσω από το όνομα» πραγματεύεται η ονομασία του Εθνικού και Καποδιστριακού Πανεπιστημιακού Αθηνών (ΕΚΠΑ) και το εκπαιδευτικό έργο του Ιωάννη Καποδίστρια.

Στο κοινωνικό ντοκιμαντέρ με τίτλο «ΕνεργητικΑδρανείς» εστιάζει στη συναισθηματική διάσταση της καθημερινότητας των ανθρώπων την εποχή της πανδημίας Covid-19.

Στο πεδίο των μυθοπλαστικών βίντεο περιέχεται η ταινία με τίτλο «Μόνος στο δρόμο» που ως βασική θεματική έχει την εξαφάνιση των μικρών παιδιών.

 

Ευχόμαστε καλή ανάγνωση και καλή αξιοποίηση στην εκπαίδευση.
Eκπαιδευτική ταινία «ΕνεργητικΑδρανείς»: Πως το βίωμα γεννά τη μάθηση και την ενσυναίσθηση ( στο πλαίσιο του μαθήματος της Νεοελληνικής Γλώσσας της Γ Λυκείου)
Authors: Πυρίδου Κωνσταντίνα , Σοφός Αλιβίζος (Λοΐζος)
Published: April 2022

Το ξέσπασμα της νόσου του κορονοϊού το Δεκέμβριο του 2019 έχει φέρει πολλές χώρες- και μέσα σ’ αυτές και τη δική μας -αντιμέτωπες με μια νέα, αναμφισβήτητα πρωτόγνωρη πραγματικότητα. Η νόσος Covid-19 ήταν αρχικά ένας κλυδωνισμός στον τομέα της υγείας για να μετατραπεί πολύ γρήγορα σ’ έναν πρωτόγνωρο κοινωνικό κλυδωνισμό. Σε κάθε περίπτωση, η καθημερινή υπερ-έκθεση μπροστά στο αδυσώπητο καθεστώς της παγκόσμιας εξάπλωσης του ιού και, κατ´επέκταση, η εξοικείωση με την ειδησεογραφία που δε θα ήταν υπερβολή να ισχυριστούμε ότι ήταν συνυφασμένη με εικόνες θανάτου, αλλά και η αίσθηση της αιχμαλωσίας - λόγω του κατ´ οίκον εγκλεισμού - και της συνεπακόλουθης αναπροσαρμογής της καθημερινότητάς μας, μας υποχρεώνουν να αναστοχαστούμε την τεταμένη ψυχική μας κατάσταση ως διαμορφωτικό πλέον παράγοντα της διαδικασίας κοινωνικού μετασχηματισμού που θα ακολουθήσει, μετά το πέρας της πανδημίας, στη δημόσια σφαίρα του 21ου αιώνα. Η εκπαιδευτική ταινία ΕνεργητικΑδρανείς αποτελεί μια απόπειρα προσέγγισης της συναισθηματικής διάστασης της καθημερινότητάς μας. Εκπαιδευτικά στοχεύει στην πληροφόρηση, στη συναισθηματική εμπλοκή και ενδυνάμωση των εκπαιδευομένων.
Η παιδαγωγική αξιοποίηση της εκπαιδευτικής μυθοπλαστικής ταινίας μικρού μήκους «Μόνος στο δρόμο» για την ευαισθητοποίηση στο ζήτημα της πρόληψης εξαφάνισης ανηλίκων
Authors: Μαρκάκη Ασπασία , Κωνστάντη Μαρία , Νησανάκη Αντωνία , Καρακώστα Αντιγόνη , Σοφός Αλιβίζος (Λοΐζος) , Κανύχης Παναγιώτης
Published: April 2022

Η εκπαιδευτική μυθοπλαστική ταινία μικρού μήκους “Μόνος στο δρόμο” πραγματεύεται το θέμα των εξαφανισμένων παιδιών. Συγκεκριμένα αφορά τα παιδιά που εξαφανίζονται χωρίς κάποια προφανή αιτία, για παράδειγμα καθώς παίζουν ή κάνουν κάποια άλλη δραστηριότητα, ή καθώς περπατάνε από μια τοποθεσία σε μία άλλη. Απευθύνεται στην ηλικιακή ομάδα παιδιών 4-8 ετών, που φοιτούν δηλαδή στο νηπιαγωγείο, στην α’ και β’ δημοτικού. Η επιλογή της ηλικιακής αυτής ομάδας έγινε λόγω της ιδιαίτερης ευαλωτότητάς της σε περιστατικά εξαφανίσεων. Επίσης, η επιλογή του είδους της μυθοπλασίας καθορίστηκε από τα αναπτυξιακά χαρακτηριστικά της εν λόγω ηλικιακής ομάδας, καθώς τα παιδιά αυτής της ηλικίας χρειάζονται μία προσομοίωση ενός περιστατικού εξαφάνισης ώστε να το επεξεργαστούν, να ταυτιστούν με τον ήρωα και να διατυπώσουν τις δικές τους ιδέες. Η ταινία συνοδεύεται από αναλυτικές οδηγίες προς τους εκπαιδευτικούς, εκπαιδευτικέςδραστηριότητες και πρόσθετο εκπαιδευτικό υλικό, που στηρίζονται στο περιεχόμενο της ταινίας, καθιστώντας την ένα ολοκληρωμένο παιδαγωγικό εργαλείο.
Το κόστος μετοχικού κεφαλαίου και οι παράγοντες συστημικού κινδύνου που το επηρεάζουν σε μια ενιαία αγορά
Authors: Μπασδέκης Χαράλαμπος
Published: April 2022

Η πολιτική απελευθέρωσης των Ευρωπαϊκών αγορών στοχεύει στη δημιουργία μιας ενιαίας ομοιογενούς αγοράς, όπου θα λειτουργεί ο θεμιτός ανταγωνισμός και η κάθε χώρα - μέλος θα έχει κοινά και τα επιμέρους χαρακτηριστικά (κόστος κεφαλαίου, επίπεδο κινδύνου) με δεδομένο ότι αποτελεί προϊόν της διαδικασίας σύγκλησης. Συνεπώς ελέγχουμε αν το ενιαίο θεσμικό πλαίσιο έχει φέρει αποτελέσματα και αν αντικατοπτρίζει την πραγματικότητα. Αν δηλαδή τα αποτελέσματα αυτά είναι άμεσα ή αν θα φανούν σε βάθος χρόνου. Υπό αυτό το πρίσμα ελέγχουμε την πορεία του κόστους μετοχικού κεφαλαίου στις χώρες της Ευρωπαϊκής Ένωσης και αν παρατηρούνται τάσεις σύγκλισης ή απόκλισης. Εν συνεχεία ελέγχουμε τα επιμέρους επίπεδα κινδύνου που σχετίζονται με το κόστος κεφαλαίου (πολιτικός, νομικός, συναλλαγματικός κίνδυνος) για να δούμε αν επιβεβαιώνουν ή μη τα αποτελέσματα της πορείας του κόστους κεφαλαίου και σε περίπτωση που παρατηρούνται τάσεις απόκλισης ή αργής σύγκλισης να εξάγουμε χρήσιμα συμπεράσματα προς ποια κατεύθυνση κινείται η αγορά και σε ποιους λόγους οφείλεται η τυχούσα ύπαρξη μη ταχείας σύγκλισης ή ακόμα και απόκλισης.Για τους λόγους αυτής της ανάλυσης μας χρησιμοποιούμε ένα εκτεταμένο Υπόδειγμα Αποτίμησης Κεφαλαιακών Στοιχείων. Χωρίζουμε τις χώρες της Ευρωπαϊκής Ένωσης σε δυο γκρουπ και σε δυο χρονικές περιόδους. Το πρώτο γκρουπ χωρών περιλαμβάνει τις πρώτες 15 χώρες που ήταν ήδη μέλη στην Ευρωπαϊκή Ένωση, οι οποίες θεωρείται ότι πληρούν όλα τα κριτήρια εισόδου στην Ο.Ν.Ε. (υπάρχει πλήρης ολοκλήρωση και κατ’ επέκταση επιμερισμός του κινδύνου) και πολλές εξ αυτών αποτελούν ήδη μέλη αυτής της Ένωσης. Το άλλο γκρουπ χωρών αποτελείται από τα 10 νέα μέλη στην Ευρωπαϊκή Ένωση. Όσον αφορά τις χρονικές περιόδους η πρώτη εκτείνεται από τον Ιανουάριο του 2000 μέχρι και τον Απρίλιο του 2003 και η δεύτερη από το Μάιο του 2003 που μπήκαν τα νέα 10 μέλη στην Ευρωπαϊκή Ένωση ως και το Δεκέμβριο του 2007. Αυτό που θα κάνουμε είναι να ελέγξουμε να συγκρίνουμε το συστηματικό κίνδυνο τόσο σε επίπεδο χωρών – εντός του κάθε γκρουπ - , όσο και σε επίπεδο μεταξύ των γκρουπ ανά χρονική περίοδο και συνολικά, προκειμένου να εξάγουμε χρήσιμα συμπεράσματα για την πορεία του. Το επόμενο βήμα είναι να ελέγξουμε πως εξελίσσεται ο συστηματικός κίνδυνος των 10 νέων χωρών στις 15 ήδη υπάρχουσες χώρες του γκρουπ, προκειμένου να δούμε τα επίπεδα επιρροής – αν υπάρχουν – των νέων μελών της Ευρωπαϊκής Ένωσης στα παλιά μέλη αυτής πριν και μετά την ένταξη των νέων μελών στην Ευρωπαϊκή Ένωση.
Company Competitiveness Profiles on the example of Polish enterprises in the Silesian Region in 2020
Authors: Flak Olaf , Głód Grzegorz
Published: April 2022

Motivation: The concept of competitiveness is used to define the ratio of enterprises to competitors and results from many internal features and the ability to deal with an external environment. However, comparing main elements of company competitiveness to each other does not give detailed position in the market sector, which is the main area of competition. Therefore it is necessary to look for a different method of companies comparison in the field of their competitiveness.

Aim: The purpose of this paper is to present a assessment method of company competitiveness based on the Company Competitiveness Profile in a market sector. The Company Competitive Profile consists of different variables of a competitive potential, a strategy of competition and a competitive advantage. This method is verified based on results of the Company Competitiveness Barometer conducted in 2021 in 177 Polish companies in the Silesian Region. The Company Competitiveness Barometer is an online research tool for assessing company competitiveness which has been used by the authors since 2012.

Results: The questionnaire used in the Company Competitiveness Barometer contains 48 questions. 45 of them are related to the characteristics of the company that are affecting its competitiveness, and 3 questions are metric questions. The questionnaire can be found on http://sensorium24.com. There were 2 hypotheses which were verified in the paper: H1: The configuration of the components of the Company Competitiveness Profile is different in different sectors of the economy. H2: Each company can be characterized in a sector by its individual Company Competitive Profile. The papers presents verification of two hypothesis which concern the Company Competitive Profiles and their use in assessment of company competitiveness in an economic sector. This is also an added value and an original contribution to company research methodology.