bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of COVID-19 Anxiety in Division I Student-Athletes
Authors: Sanborn Victoria , Todd Lauren , Schmetzer Hanna , Manitkul-Davis Nasha , Updegraff John , Gunstad John
Published: May 2021

Anxiety and depressive symptoms are prevalent in athletes. The pandemic of novel coronavirus (COVID-19) may increase risk for symptoms due to fear of exposure during competition or uncertainty regarding participation. The current study examined the prevalence of COVID-19 anxiety in 437 National Collegiate Athletic Association Division I student-athletes and its association with psychological symptoms. Only 0.2% of participants endorsed COVID-19 anxiety symptoms above cutoff. COVID-19 anxiety did not change after postponement of fall sports or differ between persons competing in different seasons. However, higher levels of COVID-19 anxiety were significantly associated with depression, anxiety, and stress. Though student-athletes generally reported low levels of psychological symptoms, females endorsed significantly higher levels than males. Low levels of COVID-19 anxiety in student-athletes may reflect protective factors (e.g., health knowledge, emotion regulation) or the tendency for this population to minimize psychological symptoms. Further investigations on the psychological impact of COVID-19 in athletes is needed.
Sea of doubts
Authors: Enserink Martin
Published: May 2021

Dozens of papers linking high carbon dioxide to unsettling changes in fish behavior fall under suspicion.
Pseudomonas aeruginosa Ventilator-Associated Pneumonia Rabbit Model for Preclinical Drug Development
Authors: Nguyen Nhu T. Q. , Gras Emmanuelle , Tran Nguyen D. , Nguyen Nhi N. Y. , Lam Hanh T. H. , Weiss William J. , Doan Thien N. M. , Diep Binh An
Published: May 2021

Development and validation of large animal models of
Pseudomonas aeruginosa
ventilator-associated pneumonia are needed for testing new drug candidates in a manner that mimics how they will be used clinically. We developed a new model in which rabbits were ventilated with low tidal volume and challenged with
P. aeruginosa
to recapitulate hallmark clinical features of acute respiratory distress syndrome (ARDS): acute lung injury and inflammation, progressive decrease in arterial oxygen partial pressure to fractional inspired oxygen PaO
2
:FiO
2
, leukopenia, neutropenia, thrombocytopenia, hyperlactatemia, severe hypotension, bacterial dissemination from lung to other organs, multiorgan dysfunction, and ultimately death.
Endoplasmic Reticulum-Associated Degradation Controls Virus Protein Homeostasis, Which Is Required for Flavivirus Propagation
Authors: Tabata Keisuke , Arakawa Masashi , Ishida Kotaro , Kobayashi Makiko , Nara Atsuki , Sugimoto Takehiro , Okada Tetsuya , Mori Kazutoshi , Morita Eiji
Published: May 2021

The results of this study reveal the cellular ERAD system controls the amount of each viral protein in virus-infected cells and that this “viral protein homeostasis” is critical for viral propagation. Furthermore, we clarified that the “convoluted membrane (CM),” which was previously considered a structure with unknown function, serves as a kind of waste dump where viral protein degradation occurs.
Differential Inhibition of HIV Replication by the 12 Interferon Alpha Subtypes
Authors: Tauzin Alexandra , Espinosa Ortiz Armando , Blake Olivia , Soundaramourty Calaiselvy , Joly-Beauparlant Charles , Nicolas Alexandre , Droit Arnaud , Dutrieux Jacques , Estaquier Jérôme , Mammano Fabrizio
Published: May 2021

The initial response against viruses relies in large part on type I interferons, which include 12 subtypes of IFN-α. These cytokines bind to a common receptor on the cell surface and trigger the expression of incompletely overlapping sets of genes.
The Stability of Model Human Coronaviruses on Textiles in the Environment and during Health Care Laundering
Authors: Owen Lucy , Shivkumar Maitreyi , Laird Katie
Published: May 2021

Synthetic textiles such as polyester could potentially act as fomites of human coronaviruses, indicating the importance of infection control procedures during handling of contaminated textiles prior to laundering. This study provides novel evidence that human coronaviruses can persist on textiles for up to 3 days and are readily transferred from polyester textile to other surfaces after 72 h of incubation.
Case to highlight a rare differential diagnosis of necrotising fasciitis in the presence of a stoma: peristomal pyoderma gangrenosum
Authors: Chong Cheryl , Palanisamy Prasad , Yeo Eugene Shen-Ann
Published: May 2021

Peristomal pyoderma gangrenosum (PPG) is a rare clinical entity, which can masquerade as the more common and lethal necrotising fasciitis. The authors present a case of PPG in a 65-year-old woman who underwent robotic abdominoperineal resection for low rectal carcinoma and returned 8 days postoperation for peristomal skin ulcerations and pain, accompanied by leucocytosis; thus, she was treated as per necrotising fasciitis and underwent surgical debridement. Thereafter, her wound continued to worsen despite conventional wound care with vacuum-assisted closure and demonstrated signs of pathergy. The case was referred to dermatology where a diagnosis of PPG was made. This case report presents a cautionary tale for fellow clinicians, highlights the diagnostic challenge, and presents an updated literature review on diagnosis and management of this unique condition.
Ectopic ACTH secretion from a metastatic gastric carcinoma with neuroendocrine component
Authors: Montebello Annalisa , Portelli Darryl , Gruppetta Mark
Published: May 2021

An elderly gentleman was admitted to hospital with severe hypokalaemia of 1.75mmol/L. A background of a recently diagnosed metastatic gastric carcinoma with a neuroendocrine component pointed towards the diagnosis of ectopic ACTH secretion causing this dangerous electrolyte imbalance. He was treated with aggressive potassium supplementation and the adrenal steroid synthesis blocker metyrapone to acutely control his Cushing’s syndrome. Chemotherapy consisting of carboplatin/etoposide combination was initiated but unfortunately the patients’ health deteriorated, and he died three months after his initial diagnosis. This case highlights the accelerated presentation of hypercortisolism due to ectopic ACTH secretion. It discusses the classification of neuroendocrine tumours and their varied prognosis depending on the underlying tumour grade. It emphasises the importance of having a multidisciplinary team to be able to care for two underlying pathologies simultaneously: both the severe hypercortisolism and his metastatic gastric tumour.
Patient with respiratory distress, facial oedema and refractory hypokalaemia
Authors: Senarathne Udara Dilrukshi , Dayanath Bolonghoge Krishantha Trixy Priyank , Punchihewa Ramani , Gunasena Bandu
Published: May 2021

Small cell lung carcinoma, when associated with co-occurrence of complications such as paraneoplastic syndrome and superior vena cava syndrome, poses a greater management challenge to the clinical team. We report a 56-year-old man who was eventually diagnosed with stage III small cell lung carcinoma, presenting with respiratory distress, facial and upper body oedema, proximal muscle weakness, hypokalaemia, new-onset hypertension and hyperglycaemia. His medical management was complicated by associated superior vena cava syndrome and Cushing’s syndrome leading to refractory hypokalemia, immunosuppression and depression. Although the patient improved clinically and biochemically with the chemotherapy and other treatments, the development of neutropenic pneumonia led to his demise. This case highlights the importance of a multidisciplinary approach to achieve better patient care and the need for good clinical vigilance to identify possible humoral manifestations of aggressive malignancies such as small cell carcinoma of the lung to assist their early detection.
Taser barb penetration causing phalangeal fracture
Authors: de Courcey Cynthia , Jones Matthew A
Published: May 2021

We present an unusual case of phalangeal fracture resulting from direct penetration by the barb of a conducted electrical weapon (Taser). When a Taser is triggered, compressed gas propels two barbs with trailing insulated wires which deliver a pulsed electrical discharge on contact. A 51-year-old man presented with a single barb of the Taser embedded in the diaphysis of the proximal phalanx and an associated open fracture. The barb was removed under local anaesthesia. The fracture was stable and was mobilised in a flexible splint. Oral antibiotics were commenced in recognition of the risk of flexor sheath and bone inoculation. While the most severe complications associated with Taser are related to the electrical component, the most common injuries are associated with falls and barb penetrations. Clinicians must be mindful of the risk of fracture, infection and soft tissue injury when such a foreign body penetrates a phalanx.
Uncommon presentation and complications of herpes zoster infection involving the cervical, vagus and accessory nerves which caused a delay in diagnosis and treatment
Authors: Wang Ziqi , Lotina Thomas , Malaty John
Published: May 2021

A 70-year-old man with a history of invasive anal squamous cell carcinoma treated with excision and chemoradiation presented to the emergency department with right-sided neck pain and submandibular lymphadenopathy. CT imaging of the head and neck was unrevealing. The patient eventually developed cranial nerves X and XI dysfunction, manifesting as severe vocal cord paralysis (dysphonia), dysphagia, asymmetric palate elevation/deviation and trapezius muscle atrophy, in addition to scalene muscle atrophy. After an extensive workup, the patient’s symptoms were determined to be due to sequelae of varicella zoster infection, which was confirmed with antibody titers. The patient’s dysphagia and dysphonia eventually improved with vocal cord medialisation injection and Botox injection. However, despite delayed treatment with acyclovir and valacyclovir, the patient continued to have neuropathic pain and exhibit signs of CN X and CN XI paresis, in addition to scalene muscle atrophy.
Spontaneous and recurrent subdural haematoma in a patient with May-Hegglin anomaly
Authors: Doherty John Anthony , Millward Christopher Paul , Sarsam Zaid
Published: May 2021

Both acute and chronic subdural haematomas typically occur following trauma. Non-traumatic causes are less common, but aetiologies include arteriovenous malformation, intracranial aneurysm rupture, tumour-associated haemorrhage and coagulopathies. May-Hegglin anomaly is an example of a coagulopathy, which is caused by a mutation in the gene encoding non-muscle myosin heavy chain 9 (MYH9) and therefore falls into a group of diseases referred to as MYH9-related diseases (MYH9-RD). The symptomology of MYH9-RD is often mild, and patients tend to experience epistaxis, gingival bleeding and bruising. Life-threatening haemorrhage rarely occurs. In this short report, we describe a patient with known May-Hegglin anomaly who presented with a potentially life-threatening, spontaneous subdural haematoma requiring surgery on two occasions. This is only the second such report in the literature, and the first of spontaneous and recurrent haemorrhage in association with May-Hegglin anomaly.
Sphingosine 1-phosphate, a potential target in neovascular retinal disease
Authors: Alshaikh Rasha A , Ryan Katie B , Waeber Christian
Published: May 2021

Neovascular ocular diseases (such as age-related macular degeneration, diabetic retinopathy and retinal vein occlusion) are characterised by common pathological processes that contribute to disease progression. These include angiogenesis, oedema, inflammation, cell death and fibrosis. Currently available therapies target the effects of vascular endothelial growth factor (VEGF), the main mediator of pathological angiogenesis. Unfortunately, VEGF blockers are expensive biological therapeutics that necessitate frequent intravitreal administration and are associated with multiple adverse effects. Thus, alternative treatment options associated with fewer side effects are required for disease management. This review introduces sphingosine 1-phosphate (S1P) as a potential pharmacological target for the treatment of neovascular ocular pathologies. S1P is a sphingolipid mediator that controls cellular growth, differentiation, survival and death. S1P actions are mediated by five G protein-coupled receptors (S1P1–5 receptors) which are abundantly expressed in all retinal and subretinal structures. The action of S1P on S1P1 receptors can reduce angiogenesis, increase endothelium integrity, reduce photoreceptor apoptosis and protect the retina against neurodegeneration. Conversely, S1P2 receptor signalling can increase neovascularisation, disrupt endothelial junctions, stimulate VEGF release, and induce retinal cell apoptosis and degeneration of neural retina. The aim of this review is to thoroughly discuss the role of S1P and its different receptor subtypes in angiogenesis, inflammation, apoptosis and fibrosis in order to determine which of these S1P-mediated processes may be targeted therapeutically.
Development and validation of a machine learning model to predict mortality risk in patients with COVID-19
Authors: Stachel Anna , Daniel Kwesi , Ding Dan , Francois Fritz , Phillips Michael , Lighter Jennifer
Published: May 2021

New York City quickly became an epicentre of the COVID-19 pandemic. An ability to triage patients was needed due to a sudden and massive increase in patients during the COVID-19 pandemic as healthcare providers incurred an exponential increase in workload,which created a strain on the staff and limited resources. Further, methods to better understand and characterise the predictors of morbidity and mortality was needed.

Methods

We developed a prediction model to predict patients at risk for mortality using only laboratory, vital and demographic information readily available in the electronic health record on more than 3395 hospital admissions with COVID-19. Multiple methods were applied, and final model was selected based on performance. A variable importance algorithm was used for interpretability, and understanding of performance and predictors was applied to the best model. We built a model with an area under the receiver operating characteristic curve of 83–97 to identify predictors and patients with high risk of mortality due to COVID-19. Oximetry, respirations, blood urea nitrogen, lymphocyte per cent, calcium, troponin and neutrophil percentage were important features, and key ranges were identified that contributed to a 50% increase in patients’ mortality prediction score. With an increasing negative predictive value starting 0.90 after the second day of admission suggests we might be able to more confidently identify likely survivors

Discussion

This study serves as a use case of a machine learning methods with visualisations to aide clinicians with a better understanding of the model and predictors of mortality.

Conclusion

As we continue to understand COVID-19, computer assisted algorithms might be able to improve the care of patients.
Study protocol for a randomised controlled trial examining the effect of blood and plasma donation on serum perfluoroalkyl and polyfluoroalkyl substance (PFAS) levels in firefighters
Authors: Silver Gabriel , Krastev Yordanka , Forbes Miriam K , Hamdorf Brenton , Lewis Barry , Tisbury Michael , Taylor Mark P , Gasiorowski Robin
Published: May 2021

Introduction

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a diverse group of compounds that have been used in hundreds of industrial applications and consumer products including aqueous film-forming foam (AFFF) for many years. Multiple national and international health and environmental agencies have accepted that PFAS exposures are associated with numerous adverse health effects. Australian firefighters have been shown to have elevated levels of PFAS in their blood, specifically perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS), due to the historical use of AFFF. While PFAS concentrations decline over time once the source of exposure has been removed, their potential adverse health effects are such that it would be prudent to develop an intervention to lower levels at a faster rate than occurs via natural elimination rates.

Methods and analysis

This is a randomised controlled trial of current and former Australian firefighters in the Metropolitan Fire Brigade/Fire Rescue Victoria, and contractors, with previous occupational exposure to PFAS and baseline elevated PFOS levels. The study is investigating whether whole blood donation every 12 weeks or plasma donation every 6 weeks will significantly reduce PFAS levels, compared with a control group. We have used covariate-adaptive randomisation to balance participants’ sex and blood PFAS levels between the three groups and would consider a 25% reduction in serum PFOS and PFHxS levels to be potentially clinically significant after 12 months of whole blood or plasma donation. A secondary analysis of health biomarkers is being made of changes between screening and week 52 in all three groups.

Ethics and dissemination

This trial has been approved by Macquarie University Human Research Ethics Committee (reference number: 3855), final protocol V.2 dated 12 June 2019. Study results will be disseminated via peer-reviewed publications and presentations at conferences.

Trial registration number

Australian New Zealand Clinical Trials Registry (ACTRN12619000204145).
Genetic testing in motor neuron disease and frontotemporal dementia: a 5-year multicentre evaluation
Authors: Cairns Lauren M , Rankin Julia , Hamad Asma , Cooper Nicola , Merrifield Katrina , Jain Vani , Rosser Elisabeth , Rogers Megan , Buston Sarah , Stopford Cheryl , Jones Gabriela , Lefroy Henrietta , Németh Andrea H , Holden Simon , Douglas Andrew G L
Published: May 2021

Introduction

Motor neuron disease (MND) and frontotemporal dementia (FTD) comprise a neurodegenerative disease spectrum. Genetic testing and counselling is complex in MND/FTD owing to incomplete penetrance, variable phenotype and variants of uncertain significance. Affected patients and unaffected relatives are commonly referred to clinical genetics to consider genetic testing. However, no consensus exists regarding how such genetic testing should best be undertaken and on which patients.

Objective

We sought to ascertain UK clinical genetics testing practice in MND/FTD referrals, with the aim of helping inform guideline development.

Methods

MND/FTD clinical genetics referrals comprising both affected patients and unaffected relatives between 2012 and 2016 were identified and a standardised proforma used to collate data from clinical records.

Results

301 referrals (70 affected, 231 unaffected) were reviewed across 10 genetics centres. Previously identified familial variants were known in 107 cases and 58% subsequently underwent testing (8 of 8 diagnostic and 54 of 99 predictive). The median number of genetic counselling appointments was 2 for diagnostic and 4 for predictive testing. Importantly, application of current UK Genomic Test Directory eligibility criteria would not have resulted in detection of all pathogenic variants observed in this cohort.

Conclusion

We propose pragmatic MND/FTD genetic testing guidelines based on appropriate genetic counselling.
The effect of diet in infancy on asthma in young adults: the Merthyr Allergy Prevention Study
Authors: Hand Sadiyah , Dunstan Frank , Jones Ken , Doull Iolo
Published: May 2021

Introduction

Early infant diet might influence the risk of subsequent allergic disease.

Methods

The Merthyr Allergy Prevention Study (MAPS) was a randomised controlled trial in infants at high risk of allergic disease. The trial determined whether a cow’s milk exclusion diet for the first 4 months of life decreased the risk of allergic disease including asthma compared with a normal diet. A soya milk preparation was offered to those in the intervention group. A standardised questionnaire for allergic disease was completed at ages 1, 7, 15 and 23 years, with clinical assessment at 1, 7 and 23 years. The effect of the intervention on the risk of atopy, asthma and wheeze at age 23 years was determined.

Findings

487 subjects entered the study; at age 23 years 299 completed the questionnaire, of which 119 attended clinical assessment. Subjects randomised to the intervention group had a significantly increased risk of atopy (adjusted OR 2.97, 95% CI 1.30 to 6.80; p=0.01) and asthma (OR 2.07, 95%CI 1.09 to 3.91; p=0.03) at age 23 years, but not wheeze (OR 1.43, 95%CI 0.87 to 2.37; p=0.16). Earlier exposure to cow’s milk was associated with a decreased risk of wheeze and asthma at age 23 years, while earlier exposure to soya milk was associated with an increased risk of atopy and asthma.

Interpretation

In infants at high risk of allergic disease, either cow’s milk exclusion or early soya milk introduction for the first 4 months of life increases the risk of atopy, wheeze and asthma in adulthood.
Interaction between Genetic Risk Scores for reduced pulmonary function and smoking, asthma and endotoxin
Authors: Sikdar Sinjini , Wyss Annah B , Lee Mi Kyeong , Hoang Thanh T , Richards Marie , Beane Freeman Laura E , Parks Christine , Thorne Peter S , Hankinson John L , Umbach David M , Motsinger-Reif Alison , London Stephanie J
Published: May 2021

Rationale

Genome-wide association studies (GWASs) have identified numerous loci associated with lower pulmonary function. Pulmonary function is strongly related to smoking and has also been associated with asthma and dust endotoxin. At the individual SNP level, genome-wide analyses of pulmonary function have not identified appreciable evidence for gene by environment interactions. Genetic Risk Scores (GRSs) may enhance power to identify gene–environment interactions, but studies are few.

Methods

We analysed 2844 individuals of European ancestry with 1000 Genomes imputed GWAS data from a case–control study of adult asthma nested within a US agricultural cohort. Pulmonary function traits were FEV1, FVC and FEV1/FVC. Using data from a recent large meta-analysis of GWAS, we constructed a weighted GRS for each trait by combining the top (p value<5×10−9) genetic variants, after clumping based on distance (±250 kb) and linkage disequilibrium (r2=0.5). We used linear regression, adjusting for relevant covariates, to estimate associations of each trait with its GRS and to assess interactions.

Results

Each trait was highly significantly associated with its GRS (all three p values<8.9×10−8). The inverse association of the GRS with FEV1/FVC was stronger for current smokers (pinteraction=0.017) or former smokers (pinteraction=0.064) when compared with never smokers and among asthmatics compared with non-asthmatics (pinteraction=0.053). No significant interactions were observed between any GRS and house dust endotoxin.

Conclusions

Evaluation of interactions using GRSs supports a greater impact of increased genetic susceptibility on reduced pulmonary function in the presence of smoking or asthma.
Carbon–carbon bond formation and green chemistry: one dream and 30 years hence
Authors: Li Chao-Jun
Published: May 2021

Carbon–carbon bond formation is the core of organic synthesis, in which organometallic reagents play the key role in the forms of 1,2-nucleophilic additions, conjugate additions, and transition-metal catalyzed cross-couplings. These reactions have enabled the production of a wide range of organic molecules in our society. Despite the enormous power of organometallic reagents in chemical synthesis, they have inherent drawbacks in the eyes of future sustainability. This account summarizes our efforts over the past three decades on the exploration of new scientific means to overcome the drawbacks and limitations of these classical organometallic reactions.
BIFURCATION AND CHAOS IN A DISCRETE PREDATOR–PREY MODEL WITH HOLLING TYPE-III FUNCTIONAL RESPONSE AND HARVESTING EFFECT
Authors: SINGH ANURAJ , DEOLIA PREETI
Published: May 2021

In this paper, we study a discrete-time predator–prey model with Holling type-III functional response and harvesting in both species. A detailed bifurcation analysis, depending on some parameter, reveals a rich bifurcation structure, including transcritical bifurcation, flip bifurcation and Neimark–Sacker bifurcation. However, some sufficient conditions to guarantee the global asymptotic stability of the trivial fixed point and unique positive fixed points are also given. The existence of chaos in the sense of Li–Yorke has been established for the discrete system. The extensive numerical simulations are given to support the analytical findings. The system exhibits flip bifurcation and Neimark–Sacker bifurcation followed by wide range of dense chaos. Further, the chaos occurred in the system can be controlled by choosing suitable value of prey harvesting.
Toward an Economically Optimal Team Design in IT-Related Innovation Projects
Authors: Bitzer Michael , Bürger Olga , Häckel Björn , Voit Christian
Published: May 2021

Driven by the increased relevance of digitalised and hypercompetitive business environments, companies need to focus on IT-related innovation projects (ITIPs) to guarantee long-term success. Although prior research has illustrated that an appropriate team design can increase project performance, an approach for determining the economically optimal team design from an ex ante perspective is missing. Against this backdrop, we follow analytical modelling research and develop a model that determines the optimal team design for an ITIP by transferring central findings of previous research regarding relevant influencing factors, e.g., team size and academic background diversity, into an ex ante economic evaluation. Thereby, our model allows the comparison of different team designs (i.e., team compositions) with regard to the prospective monetary project performance. Generally, the results show that only about a fifth of the random team designs resulted in a positive profit. In contrast, the well-founded, optimal team designs proposed by our model led to a positive profit in almost 90% of all cases. Regarding the influencing parameters, we observe that team size is the most important factor since a deviation from the optimum has a much more significant effect on the expected profit than do other factors such as work experience. To ensure the real-world fidelity and applicability of our model, we discuss the underlying assumptions with two practitioners. Our contribution is manifold: Inter alia, from an academic perspective, we enhance existing research on team design by converting well-accepted qualitative findings from a frequently investigated field outside business administration (i.e., [social] psychology) into a quantitative model that allows for the ex ante economic evaluation of team design parameters. For practitioners, we provide a model that assists managers in designing ITIP teams that are more likely to deliver desired results. This model enables managers to avoid relying only on gut feeling when designing ITIP teams, as is currently often the case due to a lack of alternative approaches.
On a class of separable modules
Authors: Ech-chaouy Rachid , Idelhadj Abdelouahab , Tribak Rachid
Published: May 2021

A module [Formula: see text] is called [Formula: see text]-separable if every proper finitely generated submodule of [Formula: see text] is contained in a proper finitely generated direct summand of [Formula: see text]. Indecomposable [Formula: see text]-separable modules are shown to be exactly the simple modules. While direct summands of an [Formula: see text]-separable module do not inherit the property, in general, the question of the stability under direct sums is unanswered. But we obtain some partial answers. It is shown that any infinite direct sum of [Formula: see text]-separable modules is [Formula: see text]-separable. Also, we prove that if [Formula: see text] and [Formula: see text] are [Formula: see text]-separable modules such that [Formula: see text] is [Formula: see text]-projective, then [Formula: see text] is [Formula: see text]-separable. We conclude the paper by providing some characterizations of several classes of rings in terms of [Formula: see text]-separable modules. Among others, we prove that the class of rings [Formula: see text] for which every (injective) [Formula: see text]-module is [Formula: see text]-separable is exactly that of semisimple rings.
Subjectivity in the Creation of Machine Learning Models
Authors: Cummings Mary L. , Li Songpo
Published: May 2021

Transportation analysts are inundated with requests to apply popular machine learning modeling techniques to datasets to uncover never-before-seen relationships that could potentially revolutionize safety, congestion, and mobility. However, the results from such models can be influenced not just by biases in underlying data, but also through practitioner-induced biases. To demonstrate the significant number of subjective judgments made in the development and interpretation of machine learning models, we developed Logistic Regression and Neural Network models for transportation-focused datasets including those looking at driving injury/fatalities and pedestrian fatalities. We then developed five different representations of feature importance for each dataset, including different feature interpretations commonly used in the machine learning community. Twelve distinct judgments were highlighted in the development and interpretation of these models, which produced inconsistent results. Such inconsistencies can lead to very different interpretations of the results, which can lead to errors of commission and omission, with significant cost and safety implications if policies are erroneously adapted from such outcomes.
Network Analysis of Internal Migration in Austria
Authors: Pitoski Dino , Lampoltshammer Thomas J. , Parycek Peter
Published: May 2021

Human migration, and urbanization as its direct consequence, are among the crucial topics in regional and national governance. People’s migration and mobility flows make a network structure, with large cities acting as hubs and smaller settlements as spokes. The essential method by which these phenomena can be analyzed comprehensively is network analysis. With this study, we first contribute to capacity building regarding the analysis of internal (national) migration data by providing a set of network indicators, models, and visualizations tested and argued for in terms of applicability and interpretability for analyzing migration. Second, we contribute to the understanding of the shape and scale of the phenomenon of internal migration, particularly toward urbanization and mobility flows between human settlements (i.e., cities, towns, and villages). Third, we demonstrate the utility of our approach on the example of internal migration flows in Austria on the settlement level and provide a longitudinal analysis for the period from 2002 to 2018. To the best of our knowledge, this is the first time that the key traits of a network of internal migration are identified for a European country, which, when accompanied by additional country analyses, has the potential to reveal the migration patterns in the region and beyond.
Classifying Co-resident Computer Programs Using Information Revealed by Resource Contention
Authors: Langehaug Tor , Borghetti Brett , Graham Scott
Published: May 2021

Modern computer architectures are complex, containing numerous components that can unintentionally reveal system operating properties. Defensive security professionals seek to minimize this kind of exposure while adversaries can leverage the data to attain an advantage. This article presents a novel covert interrogator program technique using light-weight sensor programs to target integer, floating point, and memory units within a computer’s architecture to collect data that can be used to match a running program to a known set of programs with up to 100% accuracy under simultaneous multithreading conditions. This technique is applicable to a broad spectrum of architectural components, does not rely on specific vulnerabilities, nor requires elevated privileges. Furthermore, this research demonstrates the technique in a system with operating system containers intended to provide isolation guarantees that limit a user’s ability to observe the activity of other users. In essence, this research exploits observable noise that is present whenever a program executes on a modern computer. This article presents interrogator program design considerations, a machine learning approach to identify models with high classification accuracy, and measures the effectiveness of the approach under a variety of program execution scenarios.
Conceptualizing Smart Government: Interrelations and Reciprocities with Smart City
Authors: Anthopoulos Leonidas , Sirakoulis Kleanthis , Reddick Christopher G.
Published: May 2021

Smart government (SG)
is an emerging topic, which increasingly attracts attention from scholars who work in public administration, political, and information sciences.
Smart city (SC)
on the other hand, is an emerging and multidisciplinary domain of study. It is not clear whether the two terms SG and SC co-exist or concern different domains that interrelate and interact. The aim of this paper is to investigate the term SG; to conceptualize it with components; to define the importance of these components to the SG with their relative strengths; and to clarify its relationship with the SC term. In this respect, this paper follows a multi-method approach: a comprehensive literature review to define and conceptualize the SG, and determine its components, and a Delphi study for validating the literature findings and for calculating the relative components’ strengths. The SG definitions that are in literature have several weaknesses and the authors proposed a definition to the SG that overcomes them, while a model with three rings, three dimensions and 13 components conceptualizes it. The Delphi study showed that all the SG conceptual entities are useful, and highlighted that
Citizens Engagement, Economic Growth, and Accountability
are more important compared to the others, but it is hard to decide about the less important component. Third, the
ICT Innovation
entity appears to be the most important compared to
emerging technologies
and
data
. Finally, SC and SG are indeed related but, SC is proved to be a complimentary part of the broader SG term.
Firm Dynamics and Trade
Authors: Alessandria George , Arkolakis Costas , Ruhl Kim J.
Published: May 2021

We review the literature that studies the dynamics of firms in foreign markets, at both the intensive and extensive margins, and their aggregate implications. We first summarize a set of micro facts on exporter entry, expansion, contraction, and exit and several macro facts about the response of aggregate trade flows to trade-policy and business-cycle shocks. We then present the canonical model developed to account for these facts and discuss its connection to the empirical evidence. We show how three model features—future uncertain profits, an investment in market access, and high depreciation of that access upon exit—generate transition dynamics and long-run aggregate outcomes from a cut in tariffs. The model and its extensions contribute to our understanding of trade integration and the evolution of future trade barriers. We discuss the key challenges faced by the canonical model, its possible extensions, and applications of the framework to recent global events.
Regulation of Cell Death and Signaling by Pore-Forming Resistosomes
Authors: Bi Guozhi , Zhou Jian-Min
Published: May 2021

Nucleotide-binding leucine-rich repeat receptors (NLRs) are the largest class of immune receptors in plants. They play a key role in the plant surveillance system by monitoring pathogen effectors that are delivered into the plant cell. Recent structural biology and biochemical analyses have uncovered how NLRs are activated to form oligomeric resistosomes upon the recognition of pathogen effectors. In the resistosome, the signaling domain of the NLR is brought to the center of a ringed structure to initiate immune signaling and regulated cell death (RCD). The N terminus of the coiled-coil (CC) domain of the NLR protein HOPZ-ACTIVATED RESISTANCE 1 likely forms a pore in the plasma membrane to trigger RCD in a way analogous to animal pore-forming proteins that trigger necroptosis or pyroptosis. NLRs that carry TOLL-INTERLEUKIN1-RECEPTOR as a signaling domain may also employ pore-forming resistosomes for RCD execution. In addition, increasing evidence supports intimate connections between NLRs and surface receptors in immune signaling. These new findings are rapidly advancing our understanding of the plant immune system.
Short-term research projects in cognitive neuroscience for undergraduate students: a contingency plan to maintain quality teaching during COVID-19 pandemic
Authors: Jaberzadeh Shapour , Mansouri Farshad Alizadeh
Published: May 2021

The Corona Virus Disease 19 (COVID-19) pandemic has imposed serious restrictions for academic institutions to maintain their research and teaching practical subjects. Universities have implemented adaptive measures to maintain educational activities and achieve the learning objectives for undergraduate and postgraduate students by shifting to online teaching and learning. Although such approaches have enabled delivering the theoretical content of courses during the pandemic, universities have faced serious difficulties in running practicals with actual research experiments and teaching hand-on skills because such activities potentially override the required safety guidelines. Here, we report an adaptive measure, implemented at Monash University, to run home-based studies in cognitive neuroscience and achieve learning objectives, which are normally delivered in face-to-face practicals. We introduce two specifically designed short-term research projects and describe how different aspects of these projects, such as tutorials, experiments, and assessments, were modified to meet the required social distancing. The results of cognitive tests were closely comparable between the laboratory-based and home-based experiments indicating that students followed the guidelines and the required procedures for a reliable data collection. Our assessments of students’ performance and feedback indicate that the majority of our educational goals were achieved, while all safety guidelines and distancing requirements were also met.
Antidiabetic, Antimicrobial, and Molecular Profiling of Selected Medicinal Plants
Authors: Aryal Babita , Niraula Purushottam , Khadayat Karan , Adhikari Bikash , Khatri Chhetri Dadhiram , Sapkota Basanta Kumar , Bhattarai Bibek Raj , Aryal Niraj , Parajuli Niranjan
Published: May 2021

Natural products have been the center of attraction ever since they were discovered. Among them, plant-based natural products were popular as analgesics, anti-inflammatory, antidiabetic, and cosmetics and possess widespread biotechnological applications. The use of plant products as cosmetics and therapeutics is deep-rooted in Nepalese society. Although there are few ethnobotanical studies conducted, extensive research of these valuable medicinal plants has not been a priority due to the limitation of technology and infrastructure. Here, we selected 4 traditionally used medicinal plants to examine their bioactive properties and their enzyme inhibition potential. α-Glucosidase and α-amylase inhibitory activities were investigated using an in vitro model followed up by antioxidant and antimicrobial activities. The present study shows that ethyl acetate fraction of Melastoma melabathrium (IC50 9.1 ± 0.3 µg/mL) and water fraction Acacia catechu (IC50 9.0 ± 0.6 µg/mL) exhibit strong α-glucosidase inhibition. Likewise, the highest α-amylase inhibition was shown by crude extracts of Ficus religiosa (IC50 29.2 ± 1.2 µg/mL) and ethyl acetate fractions of Shorea robusta (IC50 69.3 ± 1.1 µg/mL), and the highest radical scavenging activity was shown by F. religiosa with an IC50 67.4 ± 0.6 µg/mL. Furthermore, to identify the metabolites within the fractions, we employed high-resolution mass spectrometry (LC-HRMS) and annotated 17 known metabolites which justify our assumption on activity. Of 4 medicinal plants examined, ethyl acetate fraction of S. robusta, ethyl acetate fraction of M. melabathrium, and water or ethyl acetate fraction of A. catechu extracts illustrated the best activities. With our study, we set up a foundation that provides authentic evidence to the community for use of these traditional plants. The annotated metabolites in this study support earlier experimental evidence towards the inhibition of enzymes. Further study is necessary to explore the clinical efficacy of these secondary molecules, which might be alternatives for the treatment of diabetes and pathogens.
Nasal Carriage and Methicillin Resistance of Staphylococcus aureus among Schoolchildren in Sana’a City, Yemen
Authors: Othman Arwa Mohammed , Al-Huraibi Belques Sharaf , Assayaghi Rowa Mohammed , Al-Shami Huda Zaid
Published: May 2021

Background. Staphylococcus aureus (S. aureus) is a frequent cause of serious health problems with high morbidity and mortality. The risk of S. aureus infections is increased with the emergence of methicillin-resistant S. aureus (MRSA). This study aims to determine the nasal carriage rate of both S. aureus and MRSA among schoolchildren in Sana’a city. Methods. This is a cross-sectional study conducted from January 2018 to May 2020. Five hundred and thirty-six students were enrolled. Their age ranged from 5 to 19 years with the mean age and standard deviation equal to 13.3 ± 3.5 years. Nasal swabs were collected from each student for culturing and methicillin susceptibility testing. Results. Students with positive culture were 271 (51%) males and 265 (49%) females. S. aureus was isolated from 129 (24%) students whereas the overall prevalence of MRSA was 8 (1.5%). S. aureus was significantly recovered from students at the age group of 10–14 years (χ2 = 7.02;

p
=
0.03

), females than males (OR = 1.96; χ2 = 10.75;

p
=
0.001

), and students who were admitted into hospitals (OR = 1.6; χ2 = 4.89;

p
=
0.03

). Nevertheless, there were no significant differences between MRSA carriage and students’ age (χ2 = 2.3;

p
=
0.32

), gender (OR = 1.02; χ2 = 0.001;

p
=
0.63

), and hospital admission (OR = 1.4; χ2 = 0.25;

p
=
0.62

). Conclusions. The prevalence of MRSA is low among schoolchildren in Sana’a city. Age, gender, and previous hospital admission were statistically associated with nasal carriage of S. aureus but not MRSA nasal carriage.
The Effects of Harvesting on the Dynamics of a Leslie–Gower Model
Authors: Xie Jingli , Liu Hanyan , Luo Danfeng
Published: May 2021

In this paper, we study a Leslie–Gower predator-prey model with harvesting effects. We carry out local bifurcation analysis and stability analysis. Under certain conditions, the model is shown to undergo a supercritical Hopf bifurcation resulting in a stable limit cycle. Numerical simulations are presented to illustrate our theoretic results.
Novel Automated K-means++ Algorithm for Financial Data Sets
Authors: Du Guoyu , Li Xuehua , Zhang Lanjie , Liu Libo , Zhao Chaohua
Published: May 2021

The K-means algorithm has been extensively investigated in the field of text clustering because of its linear time complexity and adaptation to sparse matrix data. However, it has two main problems, namely, the determination of the number of clusters and the location of the initial cluster centres. In this study, we propose an improved K-means++ algorithm based on the Davies-Bouldin index (DBI) and the largest sum of distance called the SDK-means++ algorithm. Firstly, we use the term frequency-inverse document frequency to represent the data set. Secondly, we measure the distance between objects by cosine similarity. Thirdly, the initial cluster centres are selected by comparing the distance to existing initial cluster centres and the maximum density. Fourthly, clustering results are obtained using the K-means++ method. Lastly, DBI is used to obtain optimal clustering results automatically. Experimental results on real bank transaction volume data sets show that the SDK-means++ algorithm is more effective and efficient than two other algorithms in organising large financial text data sets. The F-measure value of the proposed algorithm is 0.97. The running time of the SDK-means++ algorithm is reduced by 42.9% and 22.4% compared with that for K-means and K-means++ algorithms, respectively.
Reliability-Based Opportunistic Maintenance Modeling for Multi-Component Systems with Economic Dependence under Base Warranty
Authors: Wang Rongcai , Cheng Zhonghua , Dong Enzhi , Guo Chiming , Rong Liqing
Published: May 2021

Maintenance usually plays a key role in controlling a multi-component production system within normal operations. Furthermore, the failure of components in the production system will also cause large economic losses for users due to the shutdown. Meanwhile, manufacturers of the production system will be confronted with the challenges of the warranty cost. Therefore, it is of great significance to optimize the maintenance strategy to reduce the downtime and warranty cost of the system. Opportunistic maintenance (OM) is a quite important solution to reduce the maintenance cost and improve the system performance. This paper studies the OM problem for multi-component systems with economic dependence under base warranty (BW). The irregular imperfect preventive maintenance (PM) is performed to reduce the failure rate of components at a certain PM reliability threshold. Moreover, the OM optimization model is developed to minimize the maintenance cost under the optimal OM reliability threshold of each component. A simulated annealing (SA) algorithm is proposed to determine the optimal maintenance cost of the system and the optimal OM threshold under BW. Finally, a numerical example of a belt conveyor drive device in a port is introduced to demonstrate the feasibility and advantages of the proposed model in maintenance cost optimization.
Decision and Coordination of Cross-Border E-Commerce Supply Chain: Based on Four Modes of Cooperation
Authors: Yan Wei , Zhou Huijun , Li Hui
Published: May 2021

Due to the explosive growth trend of cross-border e-commerce, a series of problems such as high transportation costs and insufficient publicity are to be solved urgently by researching on supply chain from both decision-making and coordination perspectives. Under the four-incomplete cooperative Stackelberg decision-making modes of cross-border e-commerce supply chain members, the transportation cost of overseas suppliers and the promotion strategy of domestic retailers determine the profit of the supply chain together and further influence the choice of the optimal decision-making plan. Furthermore, the Shapley value method and full cooperative income incremental sharing mechanism are used to redistribute the profits under different cooperation modes, and it is expected to provide scientific decision-making reference for domestic cross-border e-commerce enterprises to rationally choose cooperative relationships.