bluuebunny/crossref_metadata_2025 huggingface dataset:
Symmetric and asymmetric adjustment of bank deposit interest rates: empirical evidence from Kenya
Authors: Nyangu Moses Nzuki , Waweru Freshia Wangari , Marwa Nyankomo
Published: October 2021

Purpose

This paper examines the sluggish adjustment of deposit interest rate categories with response to policy rate changes in a developing economy.

Design/methodology/approach

Symmetric and asymmetric error correction models (ECMs) are employed to test the pass-through effect and adjustment speed of deposit rates when above or below their equilibrium levels.

Findings

The findings reveal an incomplete pass-through effect in both the short run and long run while mixed results of symmetric and asymmetric adjustment speed across the different deposit rate categories are observed. Collusive pricing arrangement behavior is supported by deposit rate categories that adjust more rigidly upwards than downwards, while negative customer reaction behavior is supported by deposit rate categories that adjust more rigidly downwards than upwards.

Practical implications

Even though the findings indicate an aspect of increased responsiveness over the period, the sluggish adjustment of deposit rates imply that monetary policy is still ineffective and not uniform across the different deposit rate categories.

Originality/value

To the best of the authors' knowledge, this is the first study to empirically examine both symmetric and asymmetric adjustment behavior of deposit interest rate categories in Kenya. The findings are key to policy makers as they provide insights on how long it takes to adjust different deposit rate categories to monetary policy decisions. In addition, the behavior of deposit rates partly explains why interest rates capping was imposed in Kenya in 2016.
A self-assessment tool for social responsibility in higher education. Reporting on a national policy development process in Portugal
Authors: Fonseca Susana , Lobo Fernandes Joana
Published: October 2021

Purpose

Providing higher education institutions (HEIs) with a tool for self-assessing their social responsibility (SR) that generates the information and knowledge necessary to a strategic approach to adopting the Green Paper recommendations about the SR of HEIs. Setting out the collaborative policy development process to construct the tool “Indicators of SR of HEIs” (ISRHEI).

Design/methodology/approach

After a literature review, including self-assessment (SA) tools and leading guidelines, a working group of 24 Portuguese HEIs was created to co-construct the ISRHEI tool, which was then subject to validation in a pilot study.

Findings

There are 34 indicators in the ISRHEI tool, structured by sequential levels according to the HEI alignment with SR (policies, procedures, practices and monitoring along a strategic continuum) hoping to achieve impacts on the organisational, educational, cognitive and social level.

Originality/value

This is an innovative and national policy development process for SR in Portugal. It gives insights into guiding documents, SA indicators for SR and the process of developing consensus on this topic amongst 24 HEIs in Portugal. The ISRHEI tool is tailored to the specific characteristics and level of development of HEIs.
Entrepreneurial leadership and team creativity: the roles of team psychological safety and knowledge sharing
Authors: Mehmood Muhammad Shahid , Jian Zhang , Akram Umair , Akram Zubair , Tanveer Yasir
Published: October 2021

Purpose

Creativity is vital for the innovation and survival of organizations. The present study aimed to explore the impact of entrepreneurial leadership on team creativity through team psychological safety and knowledge sharing. Social learning theory (SLT) was used to explore the relationships in this study.

Design/methodology/approach

Data were collected from the manufacturing sector of Pakistan, and a sample composed of 70 team leaders and 378 team members was used.

Findings

The results showed the positive influence of entrepreneurial leadership on team creativity. Furthermore, team psychological safety and knowledge sharing mediated the relationship between entrepreneurial leadership and team creativity. Finally, team psychological safety and knowledge sharing sequentially mediated the relationship between entrepreneurial leadership and team creativity.

Research limitations/implications

A small sample size and cross-sectional research design may hinder the generalizability of the findings. The findings suggest that leaders should practice entrepreneurial leadership principles to develop team creativity. Organizations should provide training and development programmes for their leaders and employees to learn the importance of entrepreneurial behaviors and how to explore and exploit entrepreneurial opportunities.

Originality/value

This study extends the leadership and creativity literature by exploring the role of entrepreneurial leadership in developing team creativity. Furthermore, this study was conducted in established organizations to explore entrepreneurial leadership's influence on team creativity. In contrast, earlier scholars recognized entrepreneurial leadership as a leadership style of entrepreneurs and thus examined its implications in new ventures or small and medium enterprises.
Support for environmental, social and economic tourism industry development in Cyprus
Authors: Charalambous Constantinos , Violaris John
Published: October 2021

Purpose

This paper aims to study and analyse thematic literature on sustainability and its challenges in destinations that highly depend on tourism. The aim of the paper is to focus on the opportunities and challenges for the sustainability of the tourist industry in Cyprus. The criteria for tourism sustainability are identified in UNESCO publications and are categorized as environmental, social and economic/financial. The paper examines the theory as well as the empirical applications regarding these criteria for the island of Cyprus, emphasizing the steps which have been taken by the government as well as other organizations towards maintaining industry sustainability. Opportunities that arise as a result of European Commission-funded programmes are also mentioned. Identification of the challenges is also very significant as they hinder sustainability practices. The paper tackles this issue and provides proposals as to the possible solutions to these challenges.

Design/methodology/approach

The paper provides a review of scientific and theoretical research studies by various authors on the concept and principles of sustainable tourism, the effects of tourism on society and the sustainable tourism strategy.

Findings

The basic principles of sustainable tourism development apply to all destinations, including Cyprus. The development of tourism is associated only with the observance of the principles of sustainable tourism development, which takes the form of balanced environmental and economic development and involves the observance of public interests.

Originality/value

The paper presents a viewpoint on sustainable tourism and the principles and development thereof.
Listening to Strangers, or: Three Arguments for Bounded Solidarity
Authors: Pippenger Nathan
Published: October 2021

Bounded solidarity has recently been criticized on the grounds that it valorizes homogeneity, arbitrarily prioritizes compatriots over outsiders, and is ultimately unnecessary to democracy. In response, defenders argue that solidarity is valuable because it supports the welfare state or a republican ideal of nondomination. This article argues that such defenses fail to demonstrate that bounded solidarity is not superfluous in the way that critics have claimed, leaving the ideal vulnerable to dismissal. Drawing on deliberative democratic theory, it shows that bounded solidarity among citizens is necessary in order to establish the epistemic preconditions of democratic self‐determination. Understood in epistemic terms, bounded solidarity—a disposition among citizens to gather, and assign weight to, the perspectives of other citizens—deserves support because it is inextricable from the valuable goal of democratic self‐rule.
Cytomorphological features of extramammary Paget’s disease of the vulva in a patient with diagnoses of squamous cell carcinoma of the cervix status post‐chemoradiation, and high‐grade vulvar intraepithelial neoplasia: The importance of basic principles
Authors: Gonzalez Maria Fernanda , Duhoki Dereen Mohammed
Published: October 2021

Background

Extramammary Paget’s disease (EMPD) is a rare neoplasm that commonly affects post‐menopausal women. It usually presents in the anogenital area where apocrine sweat glands are abundant, most commonly in the vulva. The disease is characterised by slow growth and high local recurrence rates. Clinically, EMPD presents as well‐demarcated erythematous lesions or plaques that may be ulcerated. Microscopically, it shows a group of atypical cells with abundant clear cytoplasm and nuclear pleomorphism.

Methods

We present the case of a 58‐year‐old female with a history of poorly differentiated squamous cell carcinoma of the cervix, status post‐radical‐hysterectomy with bilateral salpingo‐oophorectomy, and chemoradiation in 2016. The patient also had a long‐standing history of vulvar pain, skin changes on her left labia, and itching.

Results

Punch biopsies of the vulva revealed acanthosis and acantholysis of the epidermis with an intraepidermal scattering of single, or clusters of, large cells with round/oval nuclei and abundant clear cytoplasm. The cells were positive for p16, CK19, CK7, and PAX8, supporting the diagnosis of EMPD without evidence of dysplasia. The concurrent Papanicolaou smear showed a hypercellular specimen composed of hyperchromatic tissue fragments with high nuclear‐to‐cytoplasmic ratios and apoptotic bodies. The presence of intracytoplasmic mucin and the tridimensionality of the fragments supported the diagnosis of adenocarcinoma.

Conclusions

This study compares the histological and cytomorphological features of EMPD with high‐grade squamous intraepithelial lesions, since the pathogenesis, precursor lesions, etiological associations, staging, clinical treatment, and prognosis differ substantially and may have a significant clinical impact on the patient's treatment.
Assemblage reorganization of South African dragonflies due to climate change
Authors: Basel Ashleigh M. , Simaika John P. , Samways Michael J. , Midgley Guy F. , MacFadyen Sandra , Hui Cang
Published: October 2021

Aim

Climate change is expected to cause large shifts in species assemblages such as dragonflies and damselflies (Insecta: Odonata). Here, we assess the influence of environmental drivers of turnover on Odonata assemblages. Secondly, we map the predicted spatial variation in species composition, first as a gradient of assemblage similarity, and then as discrete bioregions delineating major areas of odonate endemism. Finally, we map the magnitude of expected change in species turnover in response to climate change under two emission scenarios.

Location

South Africa.

Methods

We used a spatial database comprising of 164 species of odonates and 20 covariates, to explore changes in compositional turnover using generalized dissimilarity models. Bioregions were compiled through various clustering techniques.

Results

Present‐day odonate bioregions correspond to climatic zones and are clearly separated by transitional zones with rapid spatial turnover. Present odonate bioregions are projected to undergo extensive reorganization by 2050 and 2070. Temporal turnover in species composition is expected to reach up to 80% in the large arid interior and 64% along the coast. Half of all South Africa's protected areas are likely to experience climate induced changes to dragonfly bioregions in the near future.

Main conclusions

Species assemblages are rapidly changing. This work highlights future shifts in climate will result in complex and nonlinear responses in Odonata communities. With ongoing climate change, current odonate bioregions are predicted to expand while others will contract considerably in size within the next 30 years. The current demarcated protected areas may be inadequate to protect dragonflies as climates change. Odonata can be used to track forefronts of climate change, which will likely affect a larger array of taxa as well.
MSC derived EV loaded with miRNA‐22 inhibits the inflammatory response and nerve function recovery after spinal cord injury in rats
Authors: Sheng Yongjia , Zhou Xiaohong , Wang Jin , Shen Heping , Wu Shasha , Guo Weiqun , Yang Yi
Published: October 2021

Our previous research has found that miRNA‐22 can inhibit the occurrence of pyroptosis by targeting GSDMD and decrease the production and release of inflammatory factors. In consideration of the therapeutic effects of mesenchymal stem cells (MSCs), MSCs‐EV were loaded with miRNA‐22 (EV‐miRNA‐22) to investigate the inhibitory effect of EV‐miRNA‐22 on the inflammatory response in SCI in rats in this study. LPS/Nigericin (LPS/NG) was used to induce pyroptosis in rat microglia in vitro. Propidium iodide (PI) staining was performed to observe cell permeability, lactate dehydrogenase (LDH) release assay was adopted to detect cytotoxicity, flow cytometry was conducted to detect pyroptosis level, immunofluorescence (IF) staining was utilized to observe the expression level of GSDMD (a key protein of pyroptosis), Western blot was performed to detect the expression of key proteins. For animal experiments, the T10 spinal cord of rats was clamped by aneurysm clip to construct the SCI model. BBB score, somatosensory evoked potential (SEP) and motor evoked potential (MEP) were performed to detect nerve function. HE staining and Nissl staining were used to detect spinal cord histopathology and nerve cell damage. EV‐miRNA‐22 could inhibit the occurrence of pyroptosis in microglia, suppress the cell membrane pore opening, and inhibit the release of inflammatory factors and the expression of GSDMD. In addition, EV‐miRNA‐22 showed higher pyroptosis‐inhibiting ability than EV. Consequently, EV‐miRNA‐22 could inhibit the nerve function injury after SCI in rats, inhibit the level of inflammatory factors in the tissue and the activation of microglia. In this study, we found that miRNA‐22‐loaded MSCs‐EV (EV‐miRNA‐22) could cooperate with EV to inhibit inflammatory response and nerve function repair after SCI.
Children with chronic nausea and orthostatic intolerance have unique brain network organization: A case‐control trial
Authors: Fortunato John E. , Laurienti Paul J. , Wagoner Ashley L. , Shaltout Hossam A. , Diz Debra I. , Silfer Jessy L. , Burdette Jonathan H.
Published: October 2021

Background

Determine whether subjects with chronic nausea and orthostatic intolerance share common alterations in key brain networks associated with central autonomic control: default mode, salience, and central executive networks, and the insula, a key component of the salience network.

Methods

Ten subjects (ages 12–18 years; 8 females, 2 males) with nausea predominant dyspepsia, orthostatic intolerance, and abnormal head‐upright tilt test were consecutively recruited from pediatric gastroenterology clinic. These subjects were compared with healthy controls (n = 8) without GI symptoms or orthostatic intolerance. Resting‐state fMRI and brain network modularity analyses were performed. Differences in the default mode, salience, and central executive networks, and insular connectivity were measured.

Key Results

The community structure of the default mode network and salience network was significantly different between tilt‐abnormal children and controls (p = 0.034 and 0.012, respectively), whereas, no group difference was observed in the central executive network (p = 0.48). The default mode network was more consistently “intact,” and the consistency of the community structure in the salience network was reduced in tilt‐abnormal children, especially in the insula.

Conclusions and Inferences

Children with chronic nausea and orthostatic intolerance have altered connectivity in the default mode network and salience network/insula, which supports over‐monitoring of their body and altered processing of bodily states resulting in interoceptive hyper self‐awareness. The connectivity of the salience network would not support optimal regulation of appropriate attention to internal and external stimuli, and the hyper‐connected default mode network may result in a persistent self‐referential state with feelings of emotion, pain, and anxiety.
A dated phylogeny shows Plio‐Pleistocene climates spurred evolution of antibrowsing defences in the New Zealand flora
Authors: Maurin Kévin J. L. , Smissen Rob D. , Lusk Christopher H.
Published: October 2021

Some plant traits may be legacies of coevolution with extinct megafauna. One example is the convergent evolution of ‘divaricate’ cage architectures in many New Zealand lineages, interpreted as a response to recently extinct flightless avian browsers whose ancestors arrived during the Paleogene period. Although experiments have confirmed that divaricate habit deters extant browsers, its abundance on frosty, droughty sites appears consistent with an earlier interpretation as a response to cold, dry Plio‐Pleistocene climates.

We used 45 protein‐coding sequences from plastid genomes to reconstruct the evolutionary history of the divaricate habit in extant New Zealand lineages. Our dated phylogeny of 215 species included 91% of New Zealand eudicot divaricate species.

We show that 86% of extant divaricate plants diverged from non‐divaricate sisters within the last 5 Ma, implicating Plio‐Pleistocene climates in the proliferation of cage architectures in New Zealand.

Our results, combined with other recent findings, are consistent with the synthetic hypothesis that the browser‐deterrent effect of cage architectures was strongly selected only when Plio‐Pleistocene climatic constraints prevented woody plants from growing quickly out of reach of browsers. This is consistent with the abundance of cage architectures in other regions where plant growth is restricted by aridity or short frost‐free periods.
A numerical simulation framework for bubbly flow and sound generation in laboratory-scale breaking waves
Authors: Gao Qiang , Shen Lian , Deane Grant B.
Published: October 2021

A simulation framework for bubbly flow and the sound radiated by breaking waves is presented. It consists of a two-phase flow solver, an algorithm to track bubbles and bubble creation rates, and a module to compute the sound generated by newly-formed bubbles. The sounds from breaking, third-order Stokes waves of 0.25 m wavelength and two slopes are calculated. The results show encouraging agreement with existing laboratory observations and identify the importance of air cylinder breakup in bubble creation. Remaining problems include modeling boundary effects that inhibit bubble coalescence in seawater and the generation of sound by the breakup of air cylinders.
Multilaboratory Comparison of Omadacycline MIC Test Strip to Broth Microdilution MIC against Gram-Negative, Gram-Positive, and Fastidious Bacteria
Authors: Koeth L. K. , DiFranco-Fisher J. M. , Hardy D. J. , Palavecino E. L. , Carretto E. , Windau A.
Published: October 2021

The performance of the Liofilchem omadacycline MIC Test Strip (MTS) was evaluated in a multisite study. Three testing sites collected/tested clinical isolates and one site tested challenge isolates that totaled 175
S. aureus
, 70
S. lugdunensis
, 121
E. faecalis
, 100
E. faecium
, 578 Enterobacterales, 142
Haemophilus
spp., 181
S. pneumoniae
, 45
S. anginosus
group, 35
S. pyogenes
,and 20
S. agalactiae
.
Population Pharmacokinetics and Dosing Optimization of Vancomycin in Pediatric Liver Transplant Recipients
Authors: Shoji Kensuke , Saito Jumpei , Nakagawa Hidenori , Funaki Takanori , Fukuda Akinari , Sakamoto Seisuke , Kasahara Mureo , Momper Jeremiah D. , Capparelli Edmund V. , Miyairi Isao
Published: October 2021

We evaluated vancomycin pharmacokinetics in pediatric LT recipients and developed a population pharmacokinetics model by considering various factors that might account for alterations in vancomycin pharmacokinetics. Our analyses revealed that lower serum creatinine levels and a shorter duration from the day of LT were associated with higher vancomycin clearance and led to subtherapeutic drug exposure.
Pregnancy-related healthcare utilisation in Agincourt, South Africa, 1993–2018: a longitudinal surveillance study of rural mothers
Authors: Sack Daniel E , Wagner Ryan G , Ohene-Kwofie Daniel , Kabudula Chodziwadziwa W , Price Jessica , Ginsburg Carren , Audet Carolyn M
Published: October 2021

Introduction

Pregnancy-related health services, an important mediator of global health priorities, require robust health infrastructure. We described pregnancy-related healthcare utilisation among rural South African women from 1993 to 2018, a period of social, political and economic transition.

Methods

We included participants enrolled in the Agincourt Health and Socio-Demographic Surveillance System in Mpumalanga Province, South Africa, a population-based longitudinal cohort, who reported pregnancy between 1993 and 2018. We assessed age, antenatal visits, years of education, pregnancy intention, nationality, residency status, previous pregnancies, prepregnancy and postpregnancy contraceptive use, and student status over the study period and modelled predictors of antenatal care utilisation (ordinal), skilled birth attendant presence (logistic) and delivery at a health facility (logistic).

Results

Between 1993 and 2018, 51 355 pregnancies occurred. Median antenatal visits, skilled birth attendant presence and healthcare facility deliveries increased over time. Delivery in 2018 vs 2004 was associated with an increased likelihood of ≥1 additional antenatal visits (adjusted OR (aOR) 10.81, 95% CI 9.99 to 11.71), skilled birth attendant presence (aOR 4.58, 95% CI 3.70 to 5.67) and delivery at a health facility (aOR 3.78, 95% CI 3.15 to 4.54). Women of Mozambican origin were less likely to deliver with a skilled birth attendant (aOR 0.42, 95% CI 0.39 to 0.45) or at a health facility (aOR 0.43, 95% CI 0.41 to 0.46) versus South Africans. Temporary migrants reported fewer antenatal visits (aOR 0.35, 95% CI 0.33 to 0.38) but were more likely to deliver with a skilled birth attendant (aOR 1.91, 95% CI 1.66 to 2.2) or at a health facility (aOR 1.4, 95% CI 1.24 to 1.58) versus permanent residents.

Conclusion

Pregnancy-related healthcare utilisation and skilled birth attendant presence at delivery have increased steadily since 1993 in rural northeastern South Africa, aligning with health policy changes enacted during this time. However, mothers of Mozambican descent are still less likely to use free care, which requires further study and policy interventions.
Novel method to select meaningful outcomes for evaluation in clinical trials
Authors: McLeod Charlie , Norman Richard , Wood Jamie , Mulrennan Siobhain , Morey Sue , Schultz André , Messer Mitch , Spaapen Kate , Stoneham Matthew , Wu Yue , Smyth Alan , Blyth Christopher , Webb Steve , Mascaro Steven , Woodberry Owen , Snelling Tom
Published: October 2021

Background

A standardised framework for selecting outcomes for evaluation in trials has been proposed by the Core Outcome Measures in Effectiveness Trials working group. However, this method does not specify how to ensure that the outcomes that are selected are causally related to the disease and the health intervention being studied. Causal network diagrams may help researchers identify outcomes that are both clinically meaningful and likely to be causally dependent on the intervention, and endpoints that are, in turn, causally dependent on those outcomes. We aimed to (1) develop a generalisable method for selecting outcomes and endpoints in trials and (2) apply this method to select outcomes for evaluation in a trial investigating treatment strategies for pulmonary exacerbations of cystic fibrosis (CF).

Methods

We conducted a series of online surveys and workshops among people affected by CF. We used a modified Delphi approach to develop a consensus list of important outcomes. A workshop involving domain experts elicited how these outcomes were causally related to the underlying pathophysiological processes. Meaningful outcomes were prioritised based on the extent to which each outcome captured separate rather than common aspects of the underlying pathophysiological process.

Results

The 10 prioritised outcomes were: breathing difficulty/pain, sputum production/clearance, fatigue, appetite, pain (not related to breathing), motivation/demoralisation, fevers/night sweats, treatment burden, inability to meet personal goals and avoidance of gastrointestinal symptoms.

Conclusions

This proposed method for selecting meaningful outcomes for evaluation in clinical trials may improve the value of research as a basis for clinical decisions.
Diet-dependent acid load is associated with mean arterial pressure in a cohort of non-obese, non-black, postmenopausal women
Authors: Banerjee Tanushree , Sebastian Anthony , Frassetto Lynda
Published: October 2021

Higher sodium (Na+) intake is associated with higher blood pressure (BP). Whether this relationship is stronger with diet-dependent acid load (DAL) and in patients diagnosed with hypertension or normal BP is not well determined. We studied 170 postmenopausal women randomized to receive potassium bicarbonate or placebo for 36 months, after which 24-hour urine and arterialized blood samples were collected. We investigated the association between DAL estimated as urinary potential renal acid load (UPRAL) and mean arterial pressure (MAP) using a mixed-effects model, adjusting for age, anthropometrics, creatinine clearance, and treatment. Adjusted regression estimates for changes in Na+ and UPRAL on MAP after 12 months of follow-up were calculated, and further adjustments were made for changes in potassium (K+) and body mass index (BMI). MAP was inversely associated with UPRAL (β [95% confidence interval]: –0.11 [–0.25, –0.001]). There was an effect modification by hypertension (p-interaction = 0.04); MAP decreased significantly in normotensives, but the association was not significant in hypertensives. A decrease of 0.70 mm Hg in MAP [0.13, 1.69] per 50 mmol/24 hour reduction in Na+ was noted when the model was adjusted for change in K+. Our results with UPRAL exhibited a stronger dose–response for MAP, which remained significant after adjusting for BMI. UPRAL was independently associated with MAP even after adjusting for potential confounders, and the data showed that this association was more pronounced in normotensive patients.

Novelty: First longitudinal study on the association of UPRAL and MAP. Association was a more robust relationship than that between U [Na+/K+] ratio and MAP. UPRAL may play a significant role in the pathogenesis of primary hypertension.
Challenges in modelling diffusiophoretic transport
Authors: Ramírez-Hinestrosa Simón , Frenkel Daan
Published: October 2021

The methodology to simulate transport phenomena in bulk systems is well-established. In contrast, there is no clear consensus about the choice of techniques to model cross-transport phenomena and phoretic transport, mainly because some of the hydrodynamic descriptions are incomplete from a thermodynamic point of view. In the present paper, we use a unified framework to describe diffusio-osmosis(phoresis), and we report non-equilibrium molecular dynamics (NEMD) on such systems. We explore different simulation methods to highlight some of the technical problems that arise in the calculations. For diffusiophoresis, we use two NEMD methods: boundary-driven and field-driven. Although the two methods should be equivalent in the limit of very weak gradients, we find that finite Peclet-number effects are much stronger in boundary-driven flows than in the case where we apply fictitious color forces.

Graphic abstract
A study of traversable wormhole solutions in extended teleparallel theory of gravity with matter coupling
Authors: Ditta Allah , Hussain Ibrar , Mustafa G. , Errehymy Abdelghani , Daoud Mohammed
Published: October 2021

This study is devoted to explore the physical aspects of wormhole geometry under embedded class-1 spacetime in $$f(T,\tau )$$

f
(
T
,
τ
)

gravity, where $$\tau $$
τ
denotes the trace of the energy-momentum tensor and T is the torsion. We derive the embedded class-1 solutions by considering spherically symmetric static spacetime. The shape function is calculated in the framework of embedded class-1 spacetime. It is necessary to mention here that the calculated shape function can be used in other modified theories of gravity. To complete this study, we take diagonal and off-diagonal tetrad, and try to build a comparison by considering the validity region of energy conditions in embedded class-1 spacetime. The embedded surface diagram is given to understand the connection between the two different regions of spacetime. The validity regions of all the energy conditions are calculated. A detailed graphical analysis is provided for validity regions of all the energy conditions. The presence of exotic matter is confirmed in both the cases as the null energy condition is violated.
High harmonic generation in crystalline silicon irradiated by an intense ultrashort laser pulse
Authors: Apostolova Tzveta , Obreshkov Boyan
Published: October 2021

We investigate the high harmonic generation in bulk silicon irradiated by intense near-infrared laser pulses with pulse duration $$\le $$
≤
 100 fs. For peak field strength of the applied laser is below 1 V/Å, the spectral intensity of the emitted harmonics follows the prediction of perturbative nonlinear optics—the frequency comb consists of a series of discrete peaks at odd harmonic orders. For a pulse duration longer than 30 fs and peak laser field strength exceeding 1 V/Å, non-perturbative effects and generation of even order harmonics occur. The appearance of even harmonics is due to optical rectification of the transmitted pulse, which includes weak quasi-DC component with electric field as low as 3 V/$$\upmu $$
μ
m. In the strong coupling regime, when the peak field strength inside vacuum exceeds 1.5 V/Å, the laser creates dense breakdown plasma of electron–hole pairs, which in turn results in severe spectral broadening of the transmitted pulse. The harmonic spectrum superimposes onto a continuous background, the spectral width of individual harmonics is substantially broadened, and their central wavelength undergoes a blue shift that covers the spacing between adjacent harmonic orders.

Graphic abstract
MODELING THE NONLINEAR FISCAL REACTION FUNCTION IN MALAYSIA
Authors: LEE CHEE LOONG , AHMAD RIAYATI , Khalid NORLIN , KARIM ZULKEFLY ABDUL
Published: October 2021

The fiscal reaction function (FRF) provides valuable insights into a country’s fiscal sustainability and output stability. However, there is no consensus yet on how to model it. Thus, this study investigates the best functional form for the FRF by adopting a nonlinear autoregressive distributed lag approach that accounts for a potential structural break in the data across periods. We examine the case of Malaysia and address the country’s data by using a break-point of the unit root test. The test results indicate the presence of a structural break in the country’s FRF. Moreover, the primary balance of Malaysia has an asymmetrical reaction to the country’s public debt and the output gap. This result suggests that a nonlinear behavior of FRF with a structural break is an accurate approach for the fiscal authority in Malaysia (for example, the Ministry of Finance) in designing prudent fiscal policy. This study finds that an asymmetric fiscal reaction in Malaysia neither guarantees fiscal sustainability nor supports output stability, thus suggesting the need for an independent fiscal council to promote prudent fiscal policy.
MTKeras: An Automated Metamorphic Testing Platform
Authors: Liu Yelin , Zhou Zhi Quan , Chen Tsong Yueh , Liu Yang , Towey Dave
Published: October 2021

This paper presents an automated, domain-independent, metamorphic testing platform called MTKeras. In this paper, we report on an investigation demonstrating the effectiveness and usability of MTKeras through five case studies in the four domains of image classification, sentiment analysis, search engines and database management systems. We also report on the effectiveness of combining metamorphic relation (input) patterns in individual metamorphic relations, enhancing the failure-finding abilities of the individual relations. The results of our experiments support combining patterns, and the use of MTKeras. The research reported in this paper shows the applicability of metamorphic relation patterns, and introduces a practical tool for the research community.
Recommending Relevant Tutorial Fragments for API-Related Natural Language Questions
Authors: Wu Di , Jing Xiao-Yuan , Chen Haowen , Kong Xiaohui , Xuan Jifeng
Published: October 2021

Application Programming Interface (API) tutorial is an important API learning resource. To help developers learn APIs, an API tutorial is often split into a number of consecutive units that describe the same topic (i.e. tutorial fragment). We regard a tutorial fragment explaining an API as a relevant fragment of the API. Automatically recommending relevant tutorial fragments can help developers learn how to use an API. However, existing approaches often employ supervised or unsupervised manner to recommend relevant fragments, which suffers from much manual annotation effort or inaccurate recommended results. Furthermore, these approaches only support developers to input exact API names. In practice, developers often do not know which APIs to use so that they are more likely to use natural language to describe API-related questions. In this paper, we propose a novel approach, called Tutorial Fragment Recommendation (TuFraRec), to effectively recommend relevant tutorial fragments for API-related natural language questions, without much manual annotation effort. For an API tutorial, we split it into fragments and extract APIs from each fragment to build API-fragment pairs. Given a question, TuFraRec first generates several clarification APIs that are related to the question. We use clarification APIs and API-fragment pairs to construct candidate API-fragment pairs. Then, we design a semi-supervised metric learning (SML)-based model to find relevant API-fragment pairs from the candidate list, which can work well with a few labeled API-fragment pairs and a large number of unlabeled API-fragment pairs. In this way, the manual effort for labeling the relevance of API-fragment pairs can be reduced. Finally, we sort and recommend relevant API-fragment pairs based on the recommended strategy. We evaluate TuFraRec on 200 API-related natural language questions and two public tutorial datasets (Java and Android). The results demonstrate that on average TuFraRec improves NDCG@5 by 0.06 and 0.09, and improves Mean Reciprocal Rank (MRR) by 0.07 and 0.09 on two tutorial datasets as compared with the state-of-the-art approach.
A Novel Overlapping Method to Alleviate the Cold-Start Problem in Recommendation Systems
Authors: Al-Sabaawi Ali M. Ahmed , Karacan Hacer , Yenice Yusuf Erkan
Published: October 2021

Recommendation systems (RSs) are tools for interacting with large and complex information spaces. They provide a personalized view of such spaces, prioritizing items likely to be of interest to the user. The main objective of RSs is to tool up users with desired items that meet their preferences. A major problem in RSs is called: “cold-start”; it is a potential problem called so in computer-based information systems which comprises a degree of automated data modeling. Particularly, it concerns the issue in which the system cannot draw any inferences nor have it yet gathered sufficient information about users or items. Since RSs performance is substantially limited by cold-start users and cold-start items problems; this research study takes the route for a major aim to attenuate users’ cold-start problem. Still in the process of researching, sundry studies have been conducted to tackle this issue by using clustering techniques to group users according to their social relations, their ratings or both. However, a clustering technique disregards a variety of users’ tastes. In this case, the researcher has adopted the overlapping technique as a tool to deal with the clustering technique’s defects. The advantage of the overlapping technique excels over others by allowing users to belong to multi-clusters at the same time according to their behavior in the social network and ratings feedback. On that account, a novel overlapping method is presented and applied. This latter is executed by using the partitioning around medoids (PAM) algorithm to implement the clustering, which is achieved by means of exploiting social relations and confidence values. After acquiring users’ clusters, the average distances are computed in each cluster. Thereafter, a content comparison is made regarding the distances between every user and the computed distances of the clusters. If the comparison result is less than or equal to the average distance of a cluster, a new user is added to this cluster. The singular value decomposition plus (SVD[Formula: see text]) method is then applied to every cluster to compute predictions values. The outcome is calculated by computing the average of mean absolute error (MAE) and root mean square error (RMSE) for every cluster. The model is tested by two real world datasets: Ciao and FilmTrust. Ultimately, findings have exhibited a great deal of insights on how the proposed model outperformed a number of the state-of-the-art studies in terms of prediction accuracy.
Personalized API Recommendations
Authors: Yang Wenhua , Zhou Yu , Huang Zhiqiu
Published: October 2021

Application Programming Interfaces (APIs) play an important role in modern software development. Developers interact with APIs on a daily basis and thus need to learn and memorize those APIs suitable for implementing the required functions. This can be a burden even for experienced developers since there exists a mass of available APIs. API recommendation techniques focus on assisting developers in selecting suitable APIs. However, existing API recommendation techniques have not taken the developers personal characteristics into account. As a result, they cannot provide developers with personalized API recommendation services. Meanwhile, they lack the support for self-defined APIs in the recommendation. To this end, we aim to propose a personalized API recommendation method that considers developers’ differences. Our API recommendation method is based on statistical language. We propose a model structure that combines the N-gram model and the long short-term memory (LSTM) neural network and train predictive models using API invoking sequences extracted from GitHub code repositories. A general language model trained on all sorts of code data is first acquired, based on which two personalized language models that recommend personalized library APIs and self-defined APIs are trained using the code data of the developer who needs personalized services. We evaluate our personalized API recommendation method on real-world developers, and the experimental results show that our approach achieves better accuracy in recommending both library APIs and self-defined APIs compared with the state-of-the-art. The experimental results also confirm the effectiveness of our hybrid model structure and the choice of the LSTM’s size.
Python Code Smell Refactoring Route Generation Based on Association Rule and Correlation
Authors: Wang Guanglei , Chen Junhua , Gao Jianhua , Huang Zijie
Published: October 2021

Code smell is a software quality problem caused by software design flaws. Refactoring code smells can improve software maintainability. While prior works mostly focused on Java code smells, only a few prior researches detect and refactor code smells of Python. Therefore, we intend to outline a route (i.e. sequential refactoring operation) for refactoring Python code smells, including LC, LM, LMC, LPL, LSC, LBCL, LLF, MNC, CCC and LTCE. The route could instruct developers to save effort by refactoring the smell strongly correlated with other smells in advance. As a result, more smells could be resolved by a single refactoring. First, we reveal the co-occurrence and the inter-causation between smells. Then, we evaluate the smells’ correlation. Results highlight seven groups of smells with high co-occurrence. Meanwhile, 10 groups of smells correlate with each other in a significant level of Spearman’s correlation coefficient at 0.01. Finally, we generate the refactoring route based on the association rules, we exploit an empirical verification with 10 developers involved. The results of Kendall’s Tau show that the proposed refactoring route has a high inter-agreement with the developer’s perception. In conclusion, we propose four refactoring routes to provide guidance for practitioners, i.e. {LPL [Formula: see text] LLF}, {LPL [Formula: see text] LBCL}, {LPL [Formula: see text] LMC} and {LPL [Formula: see text] LM [Formula: see text] LC [Formula: see text] CCC [Formula: see text] MNC}.
Metaheuristics and Software Engineering: Past, Present, and Future
Authors: Alba Enrique , Ferrer Javier , Villalobos Ignacio
Published: October 2021

This work aims at giving an updated vision on the successful combination between Metaheuristics and Software Engineering (SE). Mostly during the 90s, varied groups of researchers dealing with search, optimization, and learning (SOL) met SE researchers, all of them looking for a quantified manner of modeling and solving problems in the software field. This paper will discuss on the construction, assessment, and exploitation tasks that help in making software programs a scientific object, subject to automatic study and control. We also want to show with several case studies how the quantification of software features and the automatic search for bugs can improve the software quality process, which eases compliance to ISO/IEEE standards. In short, we want to build intelligent automatic tools that will upgrade the quality of software products and services. Since we approach this new field as a cross-fertilization between two research domains, we then need to talk not only on metaheuristics for SE (well known by now), but also on SE for metaheuristics (not so well known nowadays). In summary, we will discuss here with three time horizons in mind: the old times [before the term search-based SE (SBSE) was used for this], the recent years on SBSE, and the many avenues for future research/development. A new body of knowledge in SOL and SE exists internationally, which is resulting in a new class of researchers able of building intelligent techniques for the benefit of software, that is, of modern societies.
Impact of Rail Fastener Looseness on Vertical Dynamic Responses of High-Speed Vehicle and Ballastless Track
Authors: Li Jianbo , Shi Hongmei
Published: October 2021

The fastener system is an essential component of the high-speed ballastless track system. A detailed analysis for the effect of fastener looseness on the vertical dynamic response of the vehicle–track coupling system is conducted from the time domain, frequency domain and time–frequency domain in this paper. A fine fastener system model is employed, which includes two spring rods and one rail pad. The preloaded force is proposed to simulate the defect of the fastener, and a looseness coefficient is defined to represent the loose degree of the fastener. First, three fastener system models are introduced into the model, respectively, and the difference in the vehicle–track dynamic is analyzed and compared. The results show that the proposed model is more consistent with the real situation and more suitable to simulate fastener defects. Then, the detailed analysis of vehicle and track dynamic responses is explored in the case of different degrees of loose fasteners and the case of completely loose fasteners. According to the simulation results, there is little impact on the dynamic response of the vehicle–track system when the looseness coefficient is less than 0.9. When the fasteners are completely loosened, the dynamic response of the wheelset and the rail significantly increases. The vibration responses of rail and wheelset enhance with the increase of the number of the completely loose fastener. The loose fasteners affect the low-frequency part of the wheelset vibration response and the high-frequency part of the rail vibration response. Finally, a time–frequency analysis method is used to analyze the system vibration response under the combined effect of the completely loose fastener and the track irregularity. The track irregularity still dominates the excitation of the system, and the vibration response of the wheelset and the rail is more sensitive to the fastener defect at low speed.
SPACE CALIBRATION OF THE ROBOT SYSTEM IN PUNCTURE SURGERY
Authors: LI CHANGLE , LI ZEQUN , ZHANG XUEHE , LIU GANGFENG , ZHAO JIE
Published: October 2021

Traditional manual puncture surgery has low positioning accuracy and poor stability. Moreover, the computed tomography method can cause strong radiation damage. Therefore, this study intends to establish a robotic system in puncture surgery, which is based on optical registration to improve safety, accuracy, and efficiency. As the accuracy of surgical space calibration influences the accuracy of the surgical system, this study proposes an improved automatic calibration algorithm for linear rotation. The algorithm can reduce error caused by manual calibration and system noise. Recalibration is not required provided that the pose of the digital reference frame is unchanged, thereby improving accuracy and efficiency. The proposed algorithm is experimentally verified to prove its effectiveness. Results show that the average errors of position and posture are 0.25[Formula: see text]mm and 0.2∘, respectively. The accuracy of calibration fully meets the needs of surgery.
Ultrasound-Induced Microbubble Cavitation Combined with Paclitaxel-Loaded Nanoparticles for the Elimination of PC-3 Cells in vitro
Authors: Wang Ziqi , Chen Chuanrong , Zou Penglin , Tao Yuchen , Gao Feng , Jia Chao , Liu Long , Duan Yourong , Shi Qiusheng
Published: October 2021

Castration-resistant prostate cancer (CRPC) and its metastases are the main reasons for the high mortality of prostate cancer. Currently, paclitaxel (PTX)-based chemotherapeutics are used as first-line drugs to treat CRPC, but this treatment does not show good effects and is accompanied by serious side effects, which may be because intravenously injected chemotherapeutic drugs have difficulties gathering at the tumor site. Therefore, a safe and effective drug delivery carrier is urgently needed to enhance the therapeutic effects of chemotherapeutic drugs against CRPC. Methoxy polyethylene glycol-polylacticco-glycolic acid-polylysine (mPEG-PLGA-PLL) nanoparticles (NPs) have shown high drug encapsulation efficiency and good therapeutic effects against ovarian cancer and pancreatic cancer, but there are few studies on their treatment against CRPC. To expand the applications of mPEG-PLGA-PLL NPs, in this study, mPEG-PLGA-PLL NPs loaded with PTX (PTX-NPs) were synthesized. The synthesized PTX-NPs had a uniform particle size and no obvious aggregation. PTX-NPs can be uptaked by PC-3 cells, which significantly promotes the inhibition of proliferation and apoptosis effects of PTX on cells and reduces the expression levels of CDK6, Cyclin D1 and Bcl-2 (cyclins and an apoptosis inhibitor), and these effects can be further enhanced by ultrasound-induced microbubble cavitation (UIMC). Our research provides a new nanocarrier for the treatment of CRPC, laying the foundation for further research in the future.