bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring optic nerve head perfusion to monitor glaucoma: a study on structure–function relationships using laser speckle flowgraphy
Authors: Calzetti Giacomo , Mursch‐Edlmayr Anna Sophie , Bata Ahmed M. , Ungaro Nicola , Mora Paolo , Chua Jacqueline , Schmidl Doreen , Bolz Matthias , Garhöfer Gerhard , Gandolfi Stefano , Schmetterer Leopold , Wong Damon
Published: April 2021

Purpose

We aimed to describe the global and localized correlations among visual field (VF) sensitivity, optic nerve head (ONH) perfusion measured by laser speckle flowgraphy (LSFG) and neural structure measured by optical coherence tomography (OCT) in open‐angle glaucoma (OAG) and to compare the floor effect for LSFG and OCT.

Methods

Cross‐sectional, multicenter study including one eye each from fifty OAG patients (mean age 69.3 years; average VF mean deviation, MD, −8.5 dB, range −25.17 to 0.85 dB) and fifty‐one controls. Patients underwent SITA standard 24‐2 automated perimetry and measurement of ONH perfusion, peripapillary retinal nerve fibre layer thickness (RNFLT) and macular ganglion cell‐inner plexiform layer thickness (GCIPLT). We tested the presence of a significant change (breakpoint) in the correlation slope with VF sensitivity to assess floor effect.

Results

The correlation between the LSFG parameter Mean All (MA) of the global disc area and MD (r = 0.56, p < 0.001) did not show a breakpoint, in contrast to the correlations between MD and OCT global parameters, which showed breakpoints at −8.53 and −4.05 dB for RNFLT and GCIPLT, respectively. Global and localized correlations with VF sensitivity were stronger for LSFG compared to OCT. In particular, LSFG outperformed OCT in the correlation with the central VF sector (r = 0.50, p < 0.001 and r = 0.06, p = 0.67 for MA and RNFLT, respectively).

Conclusion

The global and sectoral correlations with VF sensitivity and the favourable floor effect compared to OCT indicate LSFG as a promising tool to monitor progression particularly in late‐stage glaucoma. Further longitudinal studies are warranted.
Efficacy of bleb‐independent penetrating canaloplasty in primary angle‐closure glaucoma: one‐year results
Authors: Zhang Shaodan , Hu Cheng , Cheng Huanhuan , Gu Juan , Samuel Kwizera , Lin Haishuang , Deng Yuxuan , Xie Yanqian , Hu Jingjing , Le Rongrong , Xu Shuxia , Tham Clement C. , Liang Yuanbo
Published: April 2021

Purpose

To report the efficacy and safety of bleb‐independent penetrating canaloplasty in the management of primary angle‐closure glaucoma (PACG).

Methods

This single‐centre prospective interventional case series enrolled 57 eyes from 53 PACG patients with medically uncontrolled intraocular pressure (IOP) and peripheral anterior synechiae of over 270°. Penetrating canaloplasty, mainly consisted of tensioning suture‐aided Schlemm’s canal dilation and a trabeculectomy, was performed to create a direct communication between the anterior chamber and the Schlemm’s canal. Postoperative IOP, number of glaucoma medications and procedure‐related complications were evaluated. Rate of success was defined as IOP ≤ 21, ≤18 and ≤15 mmHg, and a ≥30% IOP reduction without (complete) or with/without (qualified) IOP‐lowering medications.

Results

A total of 45 eyes had 360° catheterization successfully completed. The mean preoperative IOP was 33.9 ± 11.7 mmHg (range, 13–59.6 mmHg), on 3.2 ± 0.8 glaucoma medications (range 2–5), which was decreased to 15.4 ± 3.7 mmHg (range, 8.6–22.5) and 0.2 ± 0.6 (range, 0–3) medications at 6 months and 14.8 ± 3.5 mmHg (range, 9–24) and 0.1 ± 0.3 (range, 0–1) medications at 12 months postoperatively. Complete success at 12 months were achieved in 78.9% (95% CI: 0.65–0.93), 71.1% (0.56–0.86) and 50.0% (0.33–0.67) eyes at IOP ≤ 21, ≤18 and ≤15 mmHg, respectively. Transient IOP elevation (>30 mmHg, 26.7%) and hyphema (11.1%) were the most common early surgical complications.

Conclusion

Penetrating canaloplasty in PACG appeared to have good efficacy and safety profiles in this pilot study. Further studies are justified.
Depression, stress and self‐stigma towards seeking psychological help in veterinary students
Authors: Lokhee S , Hogg RC
Published: April 2021

Previous research indicates that the prevalence of depression among veterinarians and veterinary students is high. Although self‐stigma in seeking psychological help is reportedly elevated in veterinary students, its impact on mental health has been largely unexplored. The aim of this study was to compare the levels of study‐related stress, depression symptoms and self‐stigma in veterinary students with those of non‐veterinary students, and examine whether stress and self‐stigma positively predicted depression symptoms in veterinary students. A total of 287 veterinary students and 317 non‐veterinary students from Australian universities completed an online questionnaire measuring study‐related stress, self‐stigma and depression symptoms. Results showed that veterinary students reported significantly higher levels of stress and self‐stigma than non‐veterinary students, but there was no significant difference between veterinary and non‐veterinary students in depression symptoms. Multiple regression analysis indicated that stress and self‐stigma both predicted depression symptoms in veterinary students. These findings suggest that reducing stress and help‐seeking self‐stigma in veterinary students may be important in improving their wellbeing levels. These findings are important in developing a whole‐of‐career life course approach to understanding the professional and psychological experiences of veterinarians.
A comprehensive assessment of secondary school students’ computational thinking skills
Authors: Polat Elif , Hopcan Sinan , Kucuk Sevda , Sisman Burak
Published: April 2021

Performance in and perceptions of computational thinking (CT) are considered vital dimensions for comprehensively assessing CT skills of students. In this study, secondary school students’ CT performance and their perceptions were examined in terms of certain variables including gender, grade level, achievement and self‐efficacy. Casual‐comparative and correlational methods were used. The sample of the study consisted of a total of 328 fifth‐ and sixth‐grade (10–12 years old) secondary school students taking visual programming lessons. CT performance and perception tests were employed as data collection tools. The results show that CT performance of boys was higher than that of girls. A significant difference was found in both CT performance and perception depending on grades. The results show that achievement in math positively affected CT performance and perception. However, achievement in IT affected CT performance less than achievement in math. Implications are discussed in terms of theoretical insights, practices for improving CT skills in secondary schools and directions for further research.

Practitioner notes

What is already known about this topic

Due to the complex structure of computational thinking (CT) in association with computers, cognition, learning and psychology, CT skills should be evaluated from a variety of perspectives.

CT performance and perception are considered vital dimensions for comprehensively assessing students’ CT skills.

What this paper adds

This paper proposes a CT performance test and a CT perception scale for secondary school students to explore their skills in terms of certain variables including gender, grade level and achievements in math and information technology (IT) courses.

This paper provides some evidence that CT performance of boys is better than that of girls. A significant difference was found in both CT performance and perception depending on grades. The results of the study show that math course achievement positively affected CT performance and perception. However, IT course achievement affected CT performance less than math course achievement.

Implications for practice and/or policy

CT performance is affected by different variables. Therefore, it may be beneficial to include specific topics in the curriculum that involve the use of more CT skills.

Girls’ interest and participation in practices such as programming can be encouraged.

Teachers should provide students with cognitive scaffolding to help them and to have them collaborate with each other during CT activities, especially at higher grades.

IT course content should include systematic and comprehensive CT activities to improve students’ CT skills. We suggest developing and implementing a holistic curriculum combined with IT and math lessons to improve students’ CT performance.
Robust Lexically Mediated Compensation for Coarticulation: Christmash Time Is Here Again
Authors: Luthra Sahil , Peraza‐Santiago Giovanni , Beeson Keia'na , Saltzman David , Crinnion Anne Marie , Magnuson James S.
Published: April 2021

A long‐standing question in cognitive science is how high‐level knowledge is integrated with sensory input. For example, listeners can leverage lexical knowledge to interpret an ambiguous speech sound, but do such effects reflect direct top‐down influences on perception or merely postperceptual biases? A critical test case in the domain of spoken word recognition is lexically mediated compensation for coarticulation (LCfC). Previous LCfC studies have shown that a lexically restored context phoneme (e.g., /s/ in Christma#) can alter the perceived place of articulation of a subsequent target phoneme (e.g., the initial phoneme of a stimulus from a tapes‐capes continuum), consistent with the influence of an unambiguous context phoneme in the same position. Because this phoneme‐to‐phoneme compensation for coarticulation is considered sublexical, scientists agree that evidence for LCfC would constitute strong support for top–down interaction. However, results from previous LCfC studies have been inconsistent, and positive effects have often been small. Here, we conducted extensive piloting of stimuli prior to testing for LCfC. Specifically, we ensured that context items elicited robust phoneme restoration (e.g., that the final phoneme of Christma# was reliably identified as /s/) and that unambiguous context‐final segments (e.g., a clear /s/ at the end of Christmas) drove reliable compensation for coarticulation for a subsequent target phoneme. We observed robust LCfC in a well‐powered, preregistered experiment with these pretested items (N = 40) as well as in a direct replication study (N = 40). These results provide strong evidence in favor of computational models of spoken word recognition that include top–down feedback.
The identification of artefacts in reporting of drug‐induced deaths using structural breaks analysis of time series statistics
Authors: Petruželka Benjamin , Mravčík Viktor , Barták Miroslav , Babor Thomas F.
Published: April 2021

Introduction

Drug‐related mortality is a key epidemiological indicator that is collected nationally and internationally. Significant efforts were made in 2006–2007 to improve the quality of data concerning drug‐related mortality in the Czech Republic. The aim of this article is to identify the effect of a quality improvement project on the drug‐induced mortality data reported in the General Mortality Registry (GMR), and to demonstrate how to identify, quantify and interpret changes in drug‐induced mortality based on the example of the Czech Republic.

Methods

We extracted data on illicit drug‐induced deaths from the Czech Republic GMR and Special Mortality registry (SMR) for the years between 2004 and 2012, and aggregated monthly and quarterly time series. We applied a new procedure to identify structural breakpoints in time series based on dating structural changes in standard linear regression models.

Results

In the GMR, breakpoints were identified in three time series: (i) opioid‐related deaths; (ii) other stimulant‐related deaths; and (iii) total drug‐induced deaths. In the SMR, the structural breaks were identified for opioids, volatile substances and selection D time series. In each of these time series, the analysis identified a decrease in the intercepts in the different segments.

Discussion and Conclusions

The structural breaks identified and quantified in the GMR time series were plausibly caused by the quality improvement efforts that started in 2006. These results demonstrate that it is critical for the analysis and use of drug mortality data collected in the registries to identify practice changes in the relevant registries, to quantify their influence and to adjust mortality estimates accordingly.
Endoscopic ultrasound‐guided rendezvous with a combination of 22‐gauge needle and 0.018‐inch guidewire for acute cholangitis with Cronkhite‐Canada syndrome
Authors: Takahashi Kosuke , Yasuda Ichiro , Hanaoka Tatsuyuki
Published: April 2021

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Long‐term cognitive outcome after radiosurgery in epileptic hypothalamic hamartomas and review of the literature
Authors: Hamdi Hussein , Albader Faisal , Spatola Giorgio , Laguitton Virginie , Trebuchon Agnes , Bartolomei Fabrice , Regis Jean
Published: April 2021

Objective

Epileptic patients with hypothalamic hamartoma (HH) frequently present cognitive impairments. Surgical techniques aiming at HH can be very efficient for epilepsy relief and cognitive improvement but are also demonstrated to carry a significant risk of additional reduction in memory function in these already disabled patients. Gamma knife radiosurgery (GKS) offers an efficient minimally invasive procedure. We evaluated the effect of stereotactic radiosurgery on cognitive outcome.

Methods

We designed a prospective single‐center case series study. Thirty‐nine epileptic patients (median age = 17 years, range = 4–50) with HH underwent preoperative and postoperative testing of intelligence quotient (IQ; all patients), including a working memory component, and other memory function testing (for patients ≥16 years old). All patients were prospectively evaluated and underwent complete presurgical and postsurgical clinical, electrophysiological, endocrinal, and visual assessments. In all patients, the postoperative assessment was performed at least 3 years after radiosurgery. We explored what variables correlate with cognitive outcome. Literature review was done for other surgical techniques and their risks for cognitive complications after surgery.

Results

No decline was observed in intellectual ability (including working memory) after GKS, and no memory decline was seen in adults. We observed significant improvement (>1 SD inz‐score) in working memory index (46%) and processing speed index (35%), as well as improvement in full‐scale IQ (24%), verbal comprehension index (11%), perceptual organization index (21%), verbal learning (20%), and visual learning (33%). Before GKS, the probability of seizure cessation was higher in patients with higher cognitive performance. After GKS, the cognitive improvement was significantly higher in the seizure‐free patients compared to the non‐seizure‐free patients.

Significance

We found clear cognitive improvement in a high percentage of patients but importantly no significant decline in intellectual ability (including working memory) and no decline in memory in adult patients 3 years after GKS. GKS compares favorably to the other surgical techniques in terms of cognitive outcome, with similar seizure freedom.
Machine learning in geography–Past, present, and future
Authors: Lavallin Abigail , Downs Joni A.
Published: April 2021

This paper concentrates on the different meanings of machine learning (ML) from its origins to the present and potential future, focusing on contributions within the discipline of geography. Understanding the history of ML is important both for understanding current trends and predicting future applications. The 1950s saw the first idea of ML with the Turing Test, which was described as a ‘learning machine’ that could acquire information and become artificially intelligent. This thought prevailed until the 1960s with the release of Perceptron I, which caused a shift to attempt to code computers to learn from input data in order to run like a human brain. The 1980s and 1990s saw the advancement of computing technologies which enabled ML within artificial intelligence to prosper. The development of artificial neural networks during this time shifted ML from a knowledge‐driven approach to a data‐driven one. The 2000s saw ML becoming more widespread within geography and other disciplines as unsupervised methods enabled the analysis of large data sets. More recently, deep learning emerged to enable processes to be integrated into many software services and applications. Present day ML has been defined by Stanford University (2017) as “the science of getting computers to act without being explicitly programmed”. Academic research alongside industry and government investments in ML now account for some of the most important technological advancements. The use of ML within geography has been increasing at a rapid rate paving the way for future advancements in the discipline.
Noninvasive early diagnosis of intestinal diseases based on artificial intelligence in genomics and microbiome
Authors: Zhang Weitong , Chen Xingjian , Wong Ka‐Chun
Published: April 2021

The maturing development in artificial intelligence (AI) and genomics has propelled the advances in intestinal diseases including intestinal cancer, inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS). On the other hand, colorectal cancer is the second most deadly and the third most common type of cancer in the world according to GLOBOCAN 2020 data. The mechanisms behind IBD and IBS are still speculative. The conventional methods to identify colorectal cancer, IBD, and IBS are based on endoscopy or colonoscopy to identify lesions. However, it is invasive, demanding, and time‐consuming for early‐stage intestinal diseases. To address those problems, new strategies based on blood and/or human microbiome in gut, colon, or even feces were developed; those methods took advantage of high‐throughput sequencing and machine learning approaches. In this review, we summarize the recent research and methods to diagnose intestinal diseases with machine learning technologies based on cell‐free DNA and microbiome data generated by amplicon sequencing or whole‐genome sequencing. Those methods play an important role in not only intestinal disease diagnosis but also therapy development in the near future.
The Collateral Costs of Clearing
Authors: MONNET CYRIL , NELLEN THOMAS
Published: April 2021

We study three generic clearing arrangements in the presence of two‐sided limited commitment: simple bilateral clearing, segregated collateral clearing through a third party, and—most sophisticated—central counterparty (CCP) clearing. Clearing secures the settlement of obligations from over‐the‐counter forward contracts that smooth the income of risk‐averse traders. Clearing requires collateral to guarantee settlement; this is costly, as it reduces income from investment. More sophisticated clearing arrangements require more collateral. As a result, the welfare gains of CCP clearing may be mostly due to segregation, while mutualization of losses could contribute little to welfare.
The mental health and wellbeing survey of Australian optometrists
Authors: Bentley Sharon A , Black Alex , Khawaja Nigar , Fylan Fiona , Griffiths Amanda M , Wood Joanne M
Published: April 2021

Purpose

To investigate the prevalence of mental health conditions and burnout among practising optometrists in Australia.

Methods

A cross‐sectional survey of registered practising Australian optometrists was undertaken over a three‐week period from mid‐November 2019. The survey comprised three well‐established mental health scales (Kessler Psychological Distress Scale [K10], Depression Anxiety Stress Scales [DASS‐21] and Maslach Burnout Inventory [MBI]) and an open‐ended question inviting comments.

Results

Five hundred and five respondents completed the K10, representing 8.8% of registered optometrists in Australia; 466 completed all three scales. Prevalence of moderate to severe psychological distress (K10 ≥ 25) was 30.7% (95% CI 26.7%–34.7%), with similar findings for depression and anxiety (DASS‐21). Prevalence of high burnout, as indicated by MBI‐GS exhaustion was 56.1% (95% CI 51.7%–60.4%), cynicism 57.1% (95% CI 52.7%–61.5%) and professional efficacy 23.1% (95% CI 19.4%–26.8%). Optometrists aged ≤ 30 years were 3.5 times more likely to report moderate to severe psychological distress compared to optometrists aged >30 years (OR = 3.54, P < 0.001, 95% CI 2.38–5.25). The most frequently mentioned work‐related issues concerned retail pressures, workload and career dissatisfaction.

Conclusions

The rates of mental health conditions and burnout reported by practising Australian optometrists were high compared with the general population and other health professionals. Younger age and burnout were significant risk factors for psychological distress. Interventions are required to address these issues, particularly for younger optometrists, and could include workplace modifications and building resilience to improve personal mental wellbeing and ensure patient safety.
Protective effects of sunlight exposure against PRK‐induced myopia in infant rhesus monkeys
Authors: Yang Xiaowei , Yang Yifang , Wang Yong , Wei Qi , Ding Hui , Zhong Xingwu
Published: April 2021

Purpose

Extensive clinical evidence suggests that time spent outdoors might reduce the risk of myopia. This study aimed to determine whether increasing sunlight exposure has a protective effect on hyperopic‐defocus induced myopia in a non‐human primate.

Methods

Twelve 2‐month‐old rhesus monkeys were treated monocularly with photorefractive keratectomy (PRK) (4.0 D) and divided randomly into two groups: artificial light (AL; n = 6) and natural light (NL; n = 6). Monkeys in the AL group were reared under artificial (indoor) lighting (08:00–20:00 h). Monkeys in the NL group were exposed to natural (outdoor) lighting for 4 h (09:00–11:00 and 15:00–17:00 h). Ocular refraction, corneal power and axial dimensions were measured before sunlight exposure and every 10 days after PRK. At day 180, retinal histology and apoptosis activity were evaluated by hematoxylin and eosin (H&E) staining and terminal deoxynucleotidyl transferase biotin (dUTP) nick end labelling (TUNEL) assay.

Results

Mean (±SD) PRK induced anisometropia was +3.11 (0.33) D. At the end of the experiment, both eyes of the NL monkeys exhibited significantly more hyperopia and shorter vitreous chamber depths (VCD), compared with AL monkeys (p < 0.05). The NL group exhibited a significantly slower rate of compensation to the induced anisometropia than the AL group (p < 0.05). The retinas of both groups exhibited normal histology and levels of apoptosis.

Conclusions

Moderate sunlight exposure exerts protective effects against the myopic shift resulting from PRK‐induced defocus in monkeys. These results are consistent with current clinical findings that increased outdoor exposure protects against myopia development. Sunlight exposure should serve as an independent positive factor in human myopia control.
The effect of low light levels on postural stability in older adults with age‐related macular degeneration
Authors: Dev Mahesh K , Wood Joanne M , Black Alex A
Published: April 2021

Purpose

To investigate the effect of low light levels on postural stability in older adults with and without age‐related macular degeneration (AMD).

Methods

Participants included 28 older adults [14 with AMD (mean age ± S.D., 83.4 ± 6.7 years) and 14 controls with normal vision (74.6 ± 3.3 years)]. Postural stability was assessed with eyes open on both a firm and foam surface under four lighting conditions in a randomised order: photopic (~436 lux, vertically at the eye), sudden reduction to mesopic (~436 to ~1 lux), adapted mesopic (~1 lux) and adapted mesopic with a light emitting diode (LED) door frame lighting system (~1.3 lux), using the root mean square (RMS) of the centre of pressure measures derived from an electronic force plate in the anterior‐posterior (AP) and medio‐lateral (ML) directions. Visual function was assessed binocularly (visual acuity, contrast sensitivity and visual fields), physical function was assessed using standardised measures (sit‐to‐stand, grip strength and the timed walk test) and self‐reported difficulties under low light levels were recorded using the Low Luminance Questionnaire. Data were analysed using linear mixed models.

Results

For all participants, low light levels significantly increased postural sway on the foam surface in the AP (p = 0.01) but not ML (p = 0.80) direction, but had no effect on postural stability on the firm surface. On the foam surface, while AP‐RMS sway was significantly greater in the sudden (p < 0.001) and adapted (p = 0.02) mesopic compared to the photopic condition, sway for the adapted mesopic with the LED lighting system was not significantly different to the photopic condition (p = 0.20). On the foam surface, AP‐RMS (p = 0.02) and ML‐RMS (p < 0.001) sway were significantly greater in the AMD compared to the control group. None of the measures of visual function was significantly associated with AP‐ or ML‐RMS sway.

Conclusions

On the foam surface, low light levels significantly reduced postural stability in older adults with and without AMD, and postural stability was significantly reduced for the AMD group compared to controls, regardless of light level. Importantly, the LED lighting system reduced sway under mesopic conditions, which was not significantly greater than that measured under photopic conditions in either group. These findings have important implications for enhancing the visual environment for older adults with and without AMD to improve postural stability and reduce the risk of falls in low lighting environments.
Health‐related quality of life in children at the diagnosis of Vernal Keratoconjunctivitis
Authors: Artesani Maria Cristina , Esposito Mariacristina , Sacchetti Marta , Sansone Andrea , Romanzo Antonino , Buzzonetti Luca , Fiocchi Alessandro Giovanni , Mennini Maurizio
Published: April 2021

Background

Vernal keratoconjunctivitis (VKC) is a bilateral, chronic, allergic condition mostly affecting children. Clinical evaluations may not necessarily reflect the impact of the disease on the patients’ health‐related quality of life (HRQoL). We aimed to evaluate HRQoL in children at VKC diagnosis and to analyze correlations between HRQoL and clinical and laboratory variables.

Methods

We studied 5‐ to 12‐year‐old patients with VKC. Data on clinical history, instrumental eye evaluations, blood examinations, and visual analog scale (VAS) for the subjective symptoms were collected. HRQoL was assessed through a disease‐specific validated Quality of Life in Children with Vernal Keratoconjunctivitis (QUICK) questionnaire.

Results

Seventy subjects were included in the analysis (female/male: 10/60; tarsal/mixed VKC form: 36/34). Clinical severity of VKC according to the Bonini scale was as follows: 14, mild; 36, moderate; and 20, severe. No significant difference was found concerning the distribution of patient age, gender, and history of allergic manifestations between tarsal and mixed VKC. A significant positive correlation was found between all QUICK scores and VAS scores, including different VAS subscale, while no significant correlation was found between QUICK scores and total sign scores, Schirmer's test, and corneal thickness. The presence of active severe VKC was not associated with worse HRQoL.

Conclusions

Our evidence shows that VKC patients experience impairment of HRQoL, especially in relation to the perception of symptoms independently of the ophthalmologic changes found, and that the QUICK questionnaire could be a useful tool to evaluate HRQoL in children with VKC, which may improve patients’ classification and management.
Development and validation of a nomogram to predict intraoperative blood transfusion for gastric cancer surgery
Authors: Huang Haoquan , Cao Minghui
Published: April 2021

Objective

To construct and validate a nomogram composed of preoperative variables to predict intraoperative blood transfusion for gastric cancer surgery.

Background

Intraoperative transfusion for gastric cancer surgery is a common medical procedure that is associated with increased postoperative complications.

Methods

A total of 999 patients who underwent gastrectomy between January 2010 and June 2019 were randomly allocated into the primary and validation cohorts in a 2:1 ratio. In the primary cohort, logistic analyses were performed to identify independent predictors for transfusion. Using the Akaike information criterion, selected variables were incorporated to construct a nomogram. Validations of the nomogram were performed in the primary and validation cohorts. The discrimination ability of the nomogram was assessed by the concordance index (C‐index), and calibration was assessed by calibration curves and the Hosmer–Lemeshow goodness‐of‐fit test.

Results

The following risk factors for transfusion were identified and used to construct the nomogram: ASA status (III‐IV vs I‐II: odds ratio [OR] 1.74), comorbidities (yes vs no: OR 1.57), tumour location (diffuse vs lower: OR 4.05), cTNM stage (III vs I: OR 1.95), and a preoperative haemoglobin level less than 80 g/L (vs over 120 g/L: OR 35.30). The C‐index was 0.859 and 0.850 in the primary and validation cohorts, respectively, which both indicated good discrimination of the nomogram. Additionally, both calibration curves and Hosmer–Lemeshow tests (p‐value 0.184 and 0.887, respectively) demonstrated high agreement between the predictions and actual outcomes.

Conclusion

A nomogram composed of preoperative variables to predict blood transfusion for gastric cancer surgery was effectively developed and validated. This nomogram could be used to improve the utilisation of red blood cells for gastrectomy.
Do stock markets play a role in determining COVID‐19 economic stimulus? A cross‐country analysis
Authors: Shafiullah Muhammad , Khalid Usman , Chaudhry Sajid M.
Published: April 2021

This paper makes an innovative contribution to the extant literature by analysing the determinants of economic stimulus packages implemented by governments in response to the COVID‐19 pandemic. In particular, we explore whether stock market declines observed in many countries can predict the size of COVID‐19 stimulus packages. Moreover, we explore whether a country's level of income can augment the underlying relationship between stock market declines and stimulus packages. The findings reveal that a larger stock market decline results in a larger stimulus package; however, this effect is only observed in countries that have an income level greater than the mean and/or median per capita gross domestic product (GDP). Moreover, our results show that monetary policy is more responsive to a stock market decline than fiscal policy. Thus, our results underscore the importance of international donor agencies such as the World Bank and International Monetary Fund (IMF) in supporting less affluent countries in coping with the adverse impacts of the COVID‐19 pandemic on their economies.
Mechanical Properties of Additively Manufactured Periodic Cellular Structures and Design Variations
Authors: Spear Derek G. , Palazotto Anthony N. , Kemnitz Ryan A.
Published: April 2021

Advances in manufacturing technologies have led to the development of a new approach to material selection, in which architectured designs can be created to achieve a specific mechanical objective. Cellular lattice structures have been at the forefront of this movement due to the ability to tailor their mechanical response through tuning of the topology, surface thickness, cell size, and cell density. In this work, the mechanical properties of additively manufactured periodic cellular lattices are evaluated and compared, primarily through the topology and surface thickness parameters. The evaluated lattices were based upon triply periodic minimal surfaces (TPMS), including novel variations on the base TPMS designs, which have not been tested previously. These lattices were fabricated out of Inconel 718 (IN718) through the selective laser melting (SLM) process. Specimens were tested under uniaxial compression, and the resultant mechanical properties were determined. Further discussion of the fabrication quality and deformation behavior of the lattices is provided. Results of this work indicate that the Diamond TPMS lattice has superior mechanical properties to the other lattices tested. Additionally, with the exception of the primitive TPMS lattice, the base TPMS designs exhibited superior mechanical performance to their derivative lattice designs.
Computation of Hydrodynamic and Capillary Phenomena in Binder Jet Three-Dimensional Printing
Authors: Wagner Joshua J. , Fred Higgs C.
Published: April 2021

The fundamental operation in binder jet three-dimensional printing is the deposition of liquid binder into a powder layer to selectively bond particles together. Upon droplet impact, the binder spreads into the powder bed forming a bound network of wetted particles called a primitive. A computational fluid dynamics framework is proposed to directly simulate the capillary and hydrodynamic effects of the interfacial flow that is responsible for primitive formation. The computational model uses the volume-of-fluid method for capturing dynamic binder-air interfaces, and the immersed boundary method is adopted to include particle geometries on numerical Cartesian grids. Three-phase contact angles are prescribed through an interface extension algorithm. Binder droplet impact on powder beds of varying contact angle are simulated. Furthermore, the numerical model is used to simulate liquid bridges connecting binary and ternary particle systems, and the resulting capillary and hydrodynamic forces are validated by comparison with published experimental and theoretical model results.
Particle velocity = group velocity: A common assumption in the different theories of Louis de Broglie and Erwin Schrödinger
Authors: Lima Nathan , Karam Ricardo
Published: April 2021

The identification of particle velocity with the velocity of a wave group was a crucial assumption that resolved important inconsistencies in the theoretical developments of Louis de Broglie and Erwin Schrödinger. Interestingly, this was one of the few common aspects of their work. In this paper, we present a reconstruction of how group velocity became essential for both de Broglie and Schrödinger, as well as a comparison of important differences in their theories. Pedagogical lessons to be extracted from this episode are also outlined.
A simple model system to study coupled photonic crystal microcavities
Authors: Perrier Alain , Guilloit Yvan , Cren Élodie Le , Dumeige Yannick
Published: April 2021

We have designed and experimentally studied several systems of standard coaxial cables with different impedances which mimic the operation of so-called photonic structures like coupled photonic crystal microcavities. Using elementary cells of half-meter long coaxial cables, we got resonances around 100 MHz, a range of frequencies that can be easily studied with standard teaching laboratory apparatus. Resonant mode frequency splitting has been obtained in the case of double and triple coupled cavities. Good agreement between experimental results and the transfer matrix model has been observed. The aim here is to demonstrate that a standard coaxial cable system is a very cheap and easy to implement structure to explain to undergraduate students complex phenomena that usually occur in the optical domain.
Obesity and Natural Spaces in Adults and Older People: A Systematic Review
Authors: Teixeira Andreia , Gabriel Ronaldo , Quaresma Luis , Alencoão Ana , Martinho José , Moreira Helena
Published: April 2021

Background: Obesity is an important public health issue that has increased globally in the last decade and continues to be one of the main causes of morbidity and premature mortality. An accumulating body of evidence suggests that contact with nature is a valuable resource for the promotion of a more active lifestyle and seems to have a central role in maintaining a healthy weight. The authors conducted a systematic review to summarize the findings of studies that investigated the relationship between natural spaces and obesity. Methods: Following Primary Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a literature search was conducted using 11 databases for studies fully available in English and published between 2010 and 2020, with adults (18–64 y) and/or older people (≥65 y). Results: Fifty studies were found that met all the inclusion criteria. The majority (68%) of papers found that higher availability and less distance to green and blue spaces are associated with lower levels of adiposity. These associations were positive, even after adjusting for the demographic and socioeconomic factors. Conclusions: Exploring the characteristics of green and blue spaces seems to be a promising tool for urban planning and health policies. The authors suggest the implementation of exercise programs in contact with nature for future interventions.
Stressors Experienced by Professional Jockeys
Authors: King Lewis , Cullen Sarah Jane , McArdle Jean , McGoldrick Adrian , Pugh Jennifer , Warrington Giles , Losty Ciara
Published: April 2021

The purpose of this study was to explore the sources of stress reported by professional jockeys. In total, 15 jockeys participated in semistructured interviews that included apprentice, conditional, and senior jockeys. Reflexive thematic analysis was used to analyze qualitative data that included inductive and deductive approaches. Jockeys reported a wide range of stress sources. Four core themes were identified and categorized as competitive (current form or being in a slump, pressure, horse, injury, opponents, tactical, and race day), racing industry (weight, workload, travel demands, injury concerns, suspension, and facilities), interpersonal (trainer, other jockeys, expectations of others, support networks, and communication), and career stressors (career uncertainty, career opportunities, and transitions). The findings highlight unique stressors to the jockey population, as well as stressors common with other athlete groups. Practical applied recommendations and future research directions are provided.
Not by turnout alone: Measuring the sources of electoral change, 2012 to 2016
Authors: Hill Seth J. , Hopkins Daniel J. , Huber Gregory A.
Published: April 2021

Evidence from 30,000 election precincts: Voters switching from Obama to Trump substantially drove vote change, 2012 to 2016.
Underwater maneuvering of robotic sheets through buoyancy-mediated active flutter
Authors: Byun Junghwan , Park Minjo , Baek Sang-Min , Yoon Jaeyoung , Kim Woongbae , Lee Byeongmoon , Hong Yongtaek , Cho Kyu-Jin
Published: April 2021

Soft robotic skins leverage the dynamic active fluttering in leaves for underwater maneuvering.
Evaluation of the Diagnostic Accuracy of Antibody Assays for Patients with Scrub Typhus
Authors: Kim Choon-Mee , Kim Dong-Min , Yun Na Ra
Published: April 2021

This study was carried out to evaluate the accuracy of various antibody tests for scrub typhus, namely, the indirect immunofluorescence assay (IFA) from the Korea Centers for Disease Control and Prevention (KCDC) and four commercial kits (companies A to D). The test accuracy was based on the diagnosis of scrub typhus, as defined by a positive PCR or culture.
Subduction initiation of the western Proto-Tethys Ocean: New evidence from the Cambrian intra-oceanic forearc ophiolitic mélange in the western Kunlun Orogen, NW Tibetan Plateau
Authors: Zhang Qichao , Li Zhong-Hai , Wu Zhenhan , Chen Xuanhua , Zhang Ji'en , Yang Yan
Published: April 2021

The supra-subduction zone ophiolite or ophiolitic mélange formed in the forearc setting is generally considered to be a key geological record for subduction initiation (SI) with petrological characteristics comparable to the SI-related rock sequence from forearc basalt (FAB) to boninite in the Izu-Bonin-Mariana subduction zone. Nevertheless, the standard FAB and boninite are generally difficult to observe in the forearc rocks generated during SI. Yet, a typical rock sequence indicating the SI of the western Proto-Tethys Ocean is reported for the first time in the Qimanyute intra-oceanic forearc system in the western Kunlun Orogen, Northwest Tibetan Plateau. The magmatic compositions, which range from less to more high field strength element (HFSE)-depleted and large ion lithophile element (LILE)-enriched, are changing from oceanic plagiogranites (ca. 494 Ma) to forearc basalt-like gabbros (FAB-Gs, ca. 487 Ma), boninites, and subsequent Nb-enriched gabbros (NEGs, ca. 485 Ma), which are thus consistent with the Izu-Bonin-Mariana forearc rocks as well as the Troodos and Semail supra-subduction zone-type ophiolites. The geochemical data from the chemostratigraphic succession indicate a subduction initiation process from a depleted mid-oceanic-ridge (MORB)-type mantle source with no detectable subduction input to gradual increasing involvement of subduction-derived materials (fluid/melts and sediments). The new petrological, geochemical, and geochronological data, combined with the regional geology, indicate that the well-sustained FAB-like intrusive magmas with associated boninites could provide crucial evidence for SI and further reveal that the SI of the western Proto-Tethys Ocean occurred in the Late Cambrian (494–485 Ma).
Artery of Percheron occlusion with first-pass recanalisation of the first segment of posterior cerebral artery
Authors: Elsayed Sherif , Al Balushi Ali , Schupper Alexander , Shoirah Hazem
Published: April 2021

This is an elderly patient who was found unconscious at home. CT of the head without contrast was unremarkable, while CT angiography of the head and neck revealed a subocclusive thrombus on the precommunicating (P1) segment of the left posterior cerebral artery (PCA). MRI brain revealed bilateral regions of diffusion restriction in the paramedian thalami and bilateral medial mesencephalon. Initial angiography confirmed the presence of a subocclusive thrombus in the P1 segment of the left PCA. Thrombectomy was performed achieving recanalisation of the left PCA and reperfusion of bilateral thalami via a visualised artery of Percheron. Postoperatively, the patient was kept on a daily dose of 325 mg of aspirin. The patient did not improve neurologically. A follow-up MRI brain showed diffusion restriction in the left occipital lobe and petechial haemorrhages in the bilateral thalami. The family eventually opted for palliative measures, and the patient expired on day 14 of admission due to acute respiratory failure from palliative extubating.
Management of an acute cerebral embolic infarct with thrombolysis and mechanical thrombectomy in the presence of an aortic arch floating thrombus
Authors: Udeaja Yagazie Zina , Ahmed Kasim , Choudhury Ghalib , Sekaran Lakshmanan
Published: April 2021

An aortic arch floating thrombus is a rare cause of embolic ischaemic cerebral infarction. Previously, thrombolysis or mechanical thrombectomy has been used to treat acute cerebral infarction in this context; however, combination therapy using both modalities is yet to be published. The optimal management of aortic arch floating thrombi is debated. Endovascular removal, thrombolysis, vitamin K antagonists and recently, direct oral anticoagulants have been utilised to treat aortic arch floating thrombi. Herein, we highlight the case of a patient presenting with dense hemiparesis, dysphasia and chest pain. CT imaging revealed a left middle cerebral artery thrombus and concurrent aortic arch floating thrombus. He was successfully treated with acute thrombolysis and subsequent mechanical thrombectomy of the cerebral thrombus resulting in resolution of his neurological symptoms. Repeat imaging demonstrated persistence of the aortic arch floating thrombus despite thrombolysis. The aortic arch floating thrombus was managed successfully with direct oral anticoagulant therapy.
Challenge of diagnosing splenic torsion in a paediatric patient with gastroschisis
Authors: Gordon Elliott S , Wagner Lauren A , Kennedy Joanne M
Published: April 2021

Gastroschisis is an uncommon congenital defect of the abdominal wall resulting in intestinal prolapse, most commonly associated with short gut syndrome or bowel obstruction. Wandering spleen, movement of the spleen due to the underdevelopment of splenic ligaments, has a prevalence of 0.25% and is asymptomatic in 15% of paediatric cases. An 11-year-old patient, admitted with a history of gastroschisis repaired at birth, presents with 18 months of intermittent, worsening abdominal pain. Imaging demonstrated splenomegaly and tortuosity of the splenic vein with abnormal positioning of the superior mesenteric artery and vein. The patient was found to have a wandering spleen with subacute splenic infarct secondary to splenic torsion, necessitating emergent surgical intervention. This patient experienced an extremely rare complication of gastroschisis that has not previously been reported. This complication is caused by a lack of appropriate abdominal fixation points for the spleen.
Celiac artery aneurysm causing an acute abdomen
Authors: Castelhano Rute , Win Khine Myat , Carty Sara
Published: April 2021

Abdominal pain is a very common presentation in the accident and emergency department. However, vasculitis is not the usual first differential diagnosis. This paper discusses a case of polyarteritis nodosa presenting with acute abdominal pain alone. Common surgical conditions were obviously considered, but they were not found to cause the patient’s problems. We describe how investigations led to this diagnosis discussed in detail in this paper. It is important to remember that prompt recognition of unusual life-threatening conditions can lead to timely intervention.
Successful endovascular therapy for recurrent acute limb ischaemia due to persistent sciatic artery aneurysm after femoropopliteal bypass
Authors: Ukita Kohei , Shutta Ryu , Nishino Masami , Tanouchi Jun
Published: April 2021

Persistent sciatic artery (PSA) is a rare vascular anomaly that can cause acute limb ischaemia (ALI) due to peripheral thromboembolism following aneurysm formation, and surgical repair or exclusion with or without femoropopliteal bypass is the standard treatment for these symptomatic cases of PSA. Here, we report a case of a 70-year-old man with right PSA aneurysm who suffered from recurrent ALI despite the history of right femoropopliteal bypass at the age of 58 for occlusion of right PSA and graft (femoropopliteal bypass graft)-to-tibial bypass at the age of 68 for occlusion of right posterior tibial artery. We performed a catheter angiographic examination using an intravascular ultrasound and performed an endovascular therapy (EVT) for the purpose of jailing the internal iliac artery. This is a rare case of PSA aneurysm presenting with recurrent ALI after femoropopliteal bypass successfully treated with EVT.
Early-stage Burkitt lymphoma remained in remission 7 years from diagnosis after only one cycle of chemoimmunotherapy
Authors: Al Sbihi Ali , Manasrah Nouraldeen , Sano Dahlia , Lonardo Sarah
Published: April 2021

Burkitt lymphoma (BL) is a rare, mature, fast-growing and highly aggressive B-cell neoplasm. It has a high-proliferation rate with distinctive genetic changes in the C-MYC oncogene. Treatment usually requires intense and frequent chemotherapy regimens with central nervous system prophylaxis as the usual regimens used for other non-Hodgkin’s lymphoma yield poor survival in BL. This report discusses a patient who was diagnosed with a stage II, high-grade BL who received one cycle of intense chemotherapy and refused further treatment. That patient remained in complete remission in his last follow-up; 7 years from diagnosis without requiring other therapies for his lymphoma.