bluuebunny/crossref_metadata_2025 huggingface dataset:
Opinions of Educational Administrators on Glass Ceiling Syndrome Preventing Women from Becoming Senior Managers
Authors: Akkaya Burcu
Published: February 2020

The purpose of this study is to reveal the opinions of educational administrators about the factors that arise from the glass ceiling syndrome which prevents women from becoming senior managers in educational organizations. In addition, in this study, suggestions have been developed for women to overcome the obstacles they face in reaching senior management positions. Qualitative method was used in this research. The research was conducted as a descriptive study in the survey model. The participants of the study consisted of educational administrators working in Niğde province. Semi-structured interview technique was used to examine and reveal the views of the participants in depth. Content analysis method was used in the analysis of data. According to the results, all participants think that women face glass ceiling barriers in the promotion of senior managerial positions. Obstacles to the glass ceiling are mostly due to individual factors. Individual factors were followed by organizational and social factors, respectively. Among the individual factors, the most important obstacles are women's negative view of management and their family responsibilities. Women do not aspire to management tasks because they require more workload and responsibility. In addition, male-dominated organizational policies and the sexist approach, which sees management as man's job are barriers for women. It has been suggested that women should be more willing and challenging to overcome the glass ceiling barriers. In addition, suggestions were made for senior management positions such as allocating quotas and providing flexible working hours for women.
Increased diaphragm motor unit discharge frequencies during quiet breathing in people with chronic tetraplegia
Authors: Nguyen D. A. T. , Lewis R. H. C. , Boswell‐Ruys C. L. , Hudson A. L. , Gandevia S. C. , Butler Jane E.
Published: February 2020

Key points

Respiratory muscle strength is compromised in people with tetraplegia, which may be compensated for by an increase in neural drive to the diaphragm.

We found that the discharge frequencies of diaphragm motor units are higher in people with chronic tetraplegia compared with able‐bodied people during quiet breathing.

Furthermore, we found that the area of single motor unit potentials was increased in people with tetraplegia.

These results suggest an increased motoneurone output to the diaphragm and remodelling of diaphragm motor units to maintain ventilation in tetraplegia.

People with tetraplegia have reduced inspiratory muscle strength, ∼40% of able‐bodied individuals. Paralysed or partially paralysed respiratory muscles as a result of tetraplegia compromise lung function, increase the incidence of respiratory infections and can cause dyspnoea. We hypothesised that reduced inspiratory muscle strength in tetraplegia may increase neural drive to the inspiratory muscles to maintain ventilation. We recorded the discharge properties of single motor units from the diaphragm in participants with chronic tetraplegia (8 males, 42–78 years, C3–C6 injury, AIS A–C) and able‐bodied control participants (6 males matched for age and body mass index). In each group, 117 and 166 single motor units, respectively, were discriminated from recordings in the costal diaphragm using a monopolar electrode. A linear mixed‐effects model analysis showed higher peak discharge frequencies of motor units during quiet breathing in tetraplegia (17.8 ± 4.9 Hz; mean ± SD) compared with controls (12.4 ± 2.2 Hz) (P < 0.001). There were no differences in tidal volume, inspiratory time or mean air flow between groups. Motor unit potentials in tetraplegia, compared with controls, were larger in amplitude (1.1 ± 0.7 mV and 0.5 ± 0.3 mV, respectively, P = 0.007) and area (1.83 ± 1.49 µV ms and 0.69 ± 0.52 µV ms, respectively, P = 0.003). The findings indicate that diaphragm motor unit remodelling is likely to have occurred in people with chronic tetraplegia and that there is an increase in diaphragm motor unit discharge rates during quiet breathing. These neural changes ensure that ventilation is maintained in people with chronic tetraplegia.
Obstacle-Crossing Task-Related Usual Gait Patterns of Older Adults Differentiating Falls and Gait Ability
Authors: Ko Seung-uk , Jerome Gerald J. , Simonsick Eleanor M. , Ferrucci Luigi
Published: February 2020

Obstacle crossing, such as stepping over a curb, exerts additional demands on balance control, and therefore the study of usual-pace gait patterns associated with obstacle-crossing performance may provide additional insight into understanding falls and deterioration of gait in older adults. Participants included 432 adults aged 60–96 years (218 women). Participants who failed the obstacle-crossing task (n = 181) walked slower with smaller knee range of motion than participants who successfully completed the obstacle-crossing task (all ps < .001). Participants who failed the obstacle crossing reported a greater likelihood of falling in the previous year, more balance problems, lower walking ability, and needed longer time to complete 5 chair stands than those who passed the task (all ps < .05). Obstacle-crossing task may identify gait patterns in older adults who appear functionally intact, but who are nonetheless at risk of fall and balance problems.
Neanderthal-Denisovan ancestors interbred with a distantly related hominin
Authors: Rogers Alan R. , Harris Nathan S. , Achenbach Alan A.
Published: February 2020

The ancestors of Neanderthals and Denisovans interbred with hominins who had been separate since the beginning of the Pleistocene.
Chlamydia trachomatis Oligopeptide Transporter Performs Dual Functions of Oligopeptide Transport and Peptidoglycan Recycling
Authors: Singh Raghuveer , Liechti George , Slade Jessica A. , Maurelli Anthony T.
Published: February 2020

Peptidoglycan, the sugar-amino acid polymer that composes the bacterial cell wall, requires a significant expenditure of energy to synthesize and is highly immunogenic. To minimize the loss of an energetically expensive metabolite and avoid host detection, bacteria often recycle their peptidoglycan, transporting its components back into the cytoplasm, where they can be used for subsequent rounds of new synthesis. The peptidoglycan-recycling substrate binding protein (SBP) MppA, which is responsible for recycling peptidoglycan fragments in
Escherichia coli
, has not been annotated for most intracellular pathogens.
BPIFB3 Regulates Endoplasmic Reticulum Morphology To Facilitate Flavivirus Replication
Authors: Evans Azia S. , Lennemann Nicholas J. , Coyne Carolyn B.
Published: February 2020

Flaviviruses and other arthropod-transmitted viruses represent a widespread global health problem, with limited treatment options currently available. Thus, a better understanding of the cellular requirements for their infection is needed. Both DENV and ZIKV rely on expansion of the endoplasmic reticulum (ER) and the induction of autophagy to establish productive infections. However, little is known regarding the interplay between the requirements for autophagy initiation during infection and the mechanisms used by these viruses to avoid clearance through the autophagic pathway. Our study highlights the importance of the host factor BPIFB3 in regulating flavivirus replication and further confirms that the RETREG1-dependent reticulophagy pathway is antiviral to both DENV and ZIKV.
Successful management of emphysematous gastritis with invasive gastric mucormycosis
Authors: Sharma Digvijoy
Published: February 2020

The present manuscript reports two extremely rare cases of coexisting emphysematous gastritis with gastric mucormycosis. The cases were managed successfully, considering the high mortality associated with both conditions independently. The aim of the manuscript is to elucidate the importance of prompt diagnosis, early surgical intervention for source control and concomitant application of antifungal therapy for a favourable outcome.
Case of small bowel perforation secondary to nivolumab and ipilimumab related tumour regression
Authors: Patel Kishen Rajan , Lee Lennard YW , Tripathy Arvind , McKean David
Published: February 2020

A 56-year-old man undergoing immunotherapy treatment for metastatic melanoma presented with sudden onset testicular pain radiating into his abdomen. On examination, the abdomen was generally tender with associated guarding. Imaging revealed a perforation of the small bowel at the site of a metastatic lesion. Histology revealed that this process was non-inflammatory in nature. A diagnosis of small bowel perforation secondary to immunotherapy driven rapid tumour regression was made. The patient was treated with a small bowel resection plus anastomosis and made a full recovery. This case highlights the rare potential side effect of immunotherapy in causing non-inflammatory bowel perforations secondary to rapid tumour regression.
A case of occult bilateral optic nerve aplasia with pituitary dysfunction: hidden anomaly missed on ultrasound
Authors: Saxena Harsha , Takkar Brijesh , Kumar Amber , Sarawagi Radha
Published: February 2020

We report a case of ‘occult’ bilateral optic nerve aplasia (ONA) where pituitary dysfunction was discovered subsequently. The initial ultrasonography had missed ONA in a child with bilateral microcornea, small non-dilating pupils and roving eye movements. Due to presence of relevant clinical signs in this case, ONA was re-evaluated with MRI, and was subsequently discovered to be associated with life-endangering hypopituitarism. This case raises the possible underestimation of ONA, and hence also the risk of missing life-threatening endocrine disorders.
Headache: tip of the iceberg
Authors: Kommineni Usha Bhanu , Krishnamurthy Rashmi
Published: February 2020

We report the case of a 64-year-old pseudophakic patient in a rural area who chronically suffered from headache with eye pain and was on analgesics for pain relief but never turned up to an ophthalmologist. There was lack of awareness to visit an ophthalmologist for headache as he thought that after undergoing cataract surgery, the role of ophthalmologist was limited. His approach to our centre was only after intense headache with sudden loss of vision. He had actually developed secondary glaucoma due to pupillary block angle closure as a late complication following yttrium aluminium garnet capsulotomy. After medical and surgical management, he regained his complete vision with total relief from headache.
Systemic septic emboli in tricuspid endocarditis due to an atrial communication with a right-to-left shunt
Authors: Farrant Olivia , Scozzi Gabriella , Hughes Rebecca
Published: February 2020

We present the case of a patient admitted to hospital in septic shock. He had a history of tricuspid valve infective endocarditis (IE) 6 months prior and regularly injected intravenous drugs. A bedside echo on arrival confirmed vegetations on his tricuspid valve, torrential tricuspid regurgitation and signs of significantly raised right-sided pressures. The admission chest radiograph showed consolidative changes in the lungs, suggestive of septic pulmonary emboli. He was commenced on antibiotics and treated in the high-dependency unit. He subsequently developed an acutely ischaemic right foot and nasal tip. Suspicions were raised of a paradoxical septic embolus through a right-to-left shunt, subsequently confirmed on bubble echo which showed passage of agitated saline between the atria. This was not apparent clinically or on echocardiogram during his previous episode of tricuspid valve IE, raising the possibility of the development of an acquired inter-atrial communication since his previous episode.
Impact of type 2 diabetes on postoperative outcome after hip fracture: nationwide population-based study in Taiwan
Authors: Lee Tien-Ching , Lee Yu-Li , Chen Jian-Chih , Chen Chung-Hwan , Ho Pei-Shan
Published: February 2020

The impact of diabetes mellitus (DM) on hip fracture (HFx) is still controversial. We used nationwide population-based data in Taiwan to observe postoperative outcomes of HFx in patients with type 2 diabetes mellitus (T2DM) and found that the impact of T2DM may be related to medication of blood glucose control.

Objective

Published studies evaluating diabetic patients with HFx have shown controversial outcomes. We assessed the impact of T2DM on postoperative outcomes after HFx in elderly patients using the nationwide population database in Taiwan.

Research design and methods

We used data from the National Health Research Institute in Taiwan to recruit patients who had undergone operations for HFx between 2000 and 2009. The recruited patients with T2DM were divided into the oral antidiabetic drug (OAD) cohort and the insulin cohort according to the use or non-use of insulin. Patients without DM were propensity score matched in a 1:1 ratio by four variables. We used the χ2test, linear regression and Cox proportional hazards model to assess variables, including length of hospital stay, medical cost, complications, early readmission, and 1-year mortality.

Results

We identified 5490 subjects in total. The insulin cohort exhibited prolonged hospital stay (11.8 days), higher medical costs, more complications within 30 and 90 after hip surgery, earlier readmission, and higher 1 year mortality rate (25.8%) than the OAD and non-DM cohorts. The OAD cohort had longer hospital stay (10.1 days) and higher readmission rate but fewer complications and mortality rates (14.9%) than the non-DM cohort.

Conclusions

After matching confounding factors, the T2DM with OAD control groups were not associated with higher complication or mortality rates but were associated with higher readmission rates. However, diabetic patients with insulin control have poor outcome. The impact of T2DM on the postoperative outcomes of patients with HFx may be related to blood glucose control medication.
Did psychosocial status, sociodemographics and smoking status affect non-attendance in control participants in the Danish Lung Cancer Screening Trial? A nested observational study
Authors: Malmqvist Jessica , Siersma Volkert , Thorsen Hanne , Heleno Bruno , Rasmussen Jakob Fraes , Brodersen John
Published: February 2020

Objectives

We investigated if psychosocial status, sociodemographics and smoking status affected non-attendance in the control group in the randomised Danish Lung Cancer Screening Trial (DLCST).

Design and setting

This study was an observational study nested in the DLCST. Due to large non-attendance in the control group in the second screening round we made an additional effort to collect questionnaire data from non-attenders in this group in the third screening round. We used a condition-specific questionnaire to assess psychosocial status. We analysed the differences in psychosocial status in the third and preceding rounds between non-attenders and attenders in the control group in multivariable linear regression models adjusted for sociodemographics and smoking status reported at baseline. Differences in sociodemographics and smoking status were analysed with χ2tests (categorical variables) and t-tests (continuous variables).

Primary outcome measure

Primary outcome was psychosocial status.

Participants

All control persons participating in the third screening round in the DLCST were included.

Results

Non-attenders in the third round had significantly worse psychosocial status than attenders in the scales: ‘behaviour’ 0.77 (99% CI 0.18 to 1.36), ‘self-blame’ 0.59 (99% CI 0.14 to 1.04), ‘focus on airway symptoms’ 0.22 (99% CI 0.08 to 0.36), ‘stigmatisation’ 0.51 (99% CI 0.16 to 0.86), ‘introvert’ 0.56 (99% CI 0.23 to 0.89) and ‘harms of smoking’ 0.35 (99% CI 0.11 to 0.59). Moreover, non-attenders had worse scores than attendees in the preceding screening rounds. Non-attenders also reported worse sociodemographics at baseline.

Conclusions

Non-attenders had a significantly worse psychosocial status and worse sociodemographics compared with attenders. The results of our study contribute with evidence of non-response and attrition driven by psychosocial status, which in turn may be influenced by the screening intervention itself. This can be used to adjust cancer screening trial results for bias due to differential non-attendance.

Trial registration number

Clinicaltrials.gov Protocol Registration System (NCT00496977).
Exploring the role of early-life circumstances, abilities and achievements on well-being at age 50 years: evidence from the 1958 British birth cohort study
Authors: Dodgeon Brian , Patalay Praveetha , Ploubidis George B , Wiggins Richard D
Published: February 2020

Objectives

We aim to examine the relative contributions of pathways from middle childhood/adolescence to mid-life well-being, health and cognition, in the context of family socio-economic status (SES) at birth, educational achievement and early-adulthood SES. Our approach is largely exploratory, suspecting that the strongest mediators between childhood circumstances and mid-life physical and emotional well-being may be cognitive performance during school years, material and behavioural difficulties, and educational achievement. We also explore whether the effects of childhood circumstances on mid-life physical and emotional well-being differ between men and women.

Setting/participants

Data were from the National Child Development Study, a fully-representative British birth cohort sample of 17 415 people born in 1 week in 1958.

Primary/secondary outcome measures

Our four primary mid-life outcome measures are: cognitive performance, physical and emotional well-being and quality of life. Our intermediate adult outcomes are early-adulthood social class and educational/vocational qualifications.

Results

Using structural equation modelling, we explore numerous pathways through childhood and early adulthood which are significantly linked to our outcomes. We specifically examine the mediating effects of the following: cognitive ability at ages 7, 11 and 16 years; childhood psychological issues; family material difficulties at age 7 years: housing, unemployment, finance; educational/vocational qualifications and social class position at age 42 years.

We find that social class at birth has a strong indirect effect on the age 50 outcomes via its influence on cognitive performance in childhood and adolescence, educational attainment and mid-life social class position, together with small direct effects on qualifications and social class position at age 42 years. Teenage cognitive performance has a strong positive effect on later physical health for women, while educational/vocational qualifications have a stronger positive effect on emotional well-being for men.

Conclusion

Our findings provide an understanding of the legacy of early life on multiple aspects of mid-life health, well-being, cognition and quality of life, showing stronger mediated links for men from childhood social class position to early adult social class position. The observed effect of qualifications supports those arguing that education is positively associated with subsequent cognitive functioning.
Adding evidence of the effects of treatments into relevant Wikipedia pages: a randomised trial
Authors: Adams Clive E , Montgomery Alan A , Aburrow Tony , Bloomfield Sophie , Briley Paul M , Carew Ebun , Chatterjee-Woolman Suravi , Feddah Ghalia , Friedel Johannes , Gibbard Josh , Haynes Euan , Hussein Mohsin , Jayaram Mahesh , Naylor Samuel , Perry Luke , Schmidt Lena , Siddique Umer , Tabaksert Ayla Serena , Taylor Douglas , Velani Aarti , White Douglas , Xia Jun
Published: February 2020

Objectives

To investigate the effects of adding high-grade quantitative evidence of outcomes of treatments into relevant Wikipedia pages on further information-seeking behaviour by the use of routinely collected data.

Setting

Wikipedia, Cochrane summary pages and the Cochrane Library.

Design

Randomised trial.

Participants

Wikipedia pages which were highly relevant to up-to-date Cochrane Schizophrenia systematic reviews that contained a Summary of Findings table.

Interventions

Eligible Wikipedia pages in the intervention group were seeded with tables of best evidence of the effects of care and hyperlinks to the source Cochrane review. Eligible Wikipedia pages in the control group were left unchanged.

Main outcome measures

Routinely collected data on access to the full text and summary web page (after 12 months).

Results

We randomised 70 Wikipedia pages (100% follow-up). Six of the 35 Wikipedia pages in the intervention group had the tabular format deleted during the study but all pages continued to report the same data within the text. There was no evidence of effect on either of the coprimary outcomes: full-text access adjusted ratio of geometric means 1.30, 95% CI: 0.71 to 2.38; page views 1.14, 95% CI: 0.6 to 2.13. Results were similar for all other outcomes, with exception of Altmetric score for which there was some evidence of clear effect (1.36, 95% CI: 1.05 to 1.78).

Conclusions

The pursuit of fair balance within Wikipedia healthcare pages is impressive and its reach unsurpassed. For every person who sought and clicked the reference on the ‘intervention’ Wikipedia page to seek more information (the primary outcome), many more are likely to have been informed by the page alone. Enriching Wikipedia content is, potentially, a powerful way to improve health literacy and it is possible to test the effects of seeding pages with evidence. This trial should be replicated, expanded and developed.

Trial registration number

IRCT2017070330407N2.
Status and contents of physical activity recommendations in European Union countries: a systematic comparative analysis
Authors: Gelius Peter , Tcymbal Antonina , Abu-Omar Karim , Mendes Romeu , Tribuzi Morais Sara , Whiting Stephen , Breda Joao
Published: February 2020

Objectives

We analysed the information on current national physical activity recommendations in all EU Member States provided by governments in a joint EU/WHO survey on the implementation status of the EU Council Recommendation on Health-Enhancing Physical Activity across Sectors.

Design

Cross-sectional survey.

Participants

The representatives of the 28 EU Member State governments to the EU Physical Activity Focal Point Network.

Outcome measures

National recommendations on: (A) minimum frequency, duration, intensity and lengths of bouts of physical activity, (B) preventing inactivity or sedentary behaviour and (C) further recommendations for additional health benefits, obesity prevention and specific types of activity.

Results

An official document could be located for 23 of the 28 EU Member States, while four are currently developing recommendations. For children and adolescents, most countries follow the 2010 WHO Global Recommendations for Physical Activity, but there are notable differences in the delimitation of age groups. 14 countries also followed WHO in their recommendations for adults, and 11 countries have additional advice on avoiding inactivity and sitting among adults. 18 Member States have recommendations for older adults, 12 of which follow WHO. Thirteen countries also address at least one special population (eg, pregnant women, people with disabilities and people with chronic diseases), but the level of detail varies substantially between countries.

Conclusions

The large majority of EU Member States either has physical activity recommendations in place or is in the process of developing them. There is a general tendency to use the WHO Global Recommendations as a basis, with the greatest variation observable for children and adolescents. Comparing results with a previous round of data collection shows that the number of EU countries with physical activity recommendations is increasing and that both special groups and sedentary behaviour have become more important in recent years.
James Michael Evans
Authors: Evans Paul
Published: February 2020

After working in a successful small animal practice, he joined the pharmaceutical industry. He became an author of books for pet owners and the profession, and set up the Pet Health Counsellor programme.
Classical invariants for non-Hermitian anharmonic potentials
Authors: Singh Ram Mehar , Bhardwaj S.B. , Sharma Kushal , Malik Anand , Chand Fakir
Published: February 2020

Keeping in view the importance of complex dynamical systems, we investigate the classical invariants for some non-Hermitian anharmonic potentials in one dimension. For this purpose, the rationalization method is employed under the elegance of the extended complex phase space approach. The invariants obtained are expected to play an important role in studying complex Hamiltonian systems at the classical as well as quantum levels.
Weak and strong warm logamediate anisotropic inflationary universe model
Authors: Javed Wajiha , Nawazish Iqra , Khan Mohsin Raza , Övgün Ali
Published: February 2020

In this paper we investigate a warm inflation scenario of a locally rotationally symmetric Bianchi type-I model using a background of modified Chaplygin gas. We determine the field equations and perturbations parameters, such as the scalar power spectrum, scalar spectral index, scalar potential, and tensor-to-scalar ratio under the slow roll approximation. We determine these parameters in the direction of the Hubble parameter during both the weak and strong logamediate inflationary regimes. These cosmological parameters show that the anisotropic model is compatible with WMAP 7 from the 2018 Planck observational data.
Combined treatments with metformin and phosphodiesterase inhibitors alleviate nonalcoholic fatty liver disease in high-fat diet fed rats: a comparative study
Authors: Heeba Gehan H. , El-Deen Reham M. , Abdel-latif Rania G. , Khalifa Mohamed M.A.
Published: February 2020

Nonalcoholic fatty liver disease (NAFLD) is an excessive accumulation of fats in the liver resulting in hepatic inflammation and fibrous tissue formation along with insulin resistance. This study was designed to investigate the possible protective effects of metformin alone and in combination with different phosphodiesterase inhibitors (PDEIs). Rats were fed a high-fat diet (HFD) for 16 weeks to induce NAFLD. Starting from week 12, rats received metformin alone or in combination with pentoxifylline, cilostazol, or sildenafil. HFD administration resulted in hepatic steatosis and inflammation in rats. In addition, liver index, body composition index, activities of liver enzymes, and serum lipids deviated from normal. Further, significant elevations were recorded compared to control in terms of serum glucose, insulin, and HOMA-IR (homeostasis model assessment index for insulin resistance), oxidative stress parameters, hepatic TNF-α and NF-κB gene expression, and iNOS protein expression. Rats treated with metformin showed a significant improvement in the aforementioned parameters. However, the addition of pentoxifylline to metformin treatment synergized its action and produced a fortified effect against HFD-induced NAFLD better than other PDEIs. Data from this study indicated that combined treatment of metformin and pentoxifylline had the most remarkable ameliorated effects against HFD-induced NAFLD; further clinical investigations are needed to approve PDEIs for NAFLD treatment.
Loss of endothelin type B receptor function improves insulin sensitivity in rats
Authors: Rivera-Gonzalez Osvaldo J. , Kasztan Malgorzata , Johnston Jermaine G. , Hyndman Kelly A. , Speed Joshua S.
Published: February 2020

High salt intake (HS) is associated with obesity and insulin resistance. ET-1, a peptide released in response to HS, inhibits the actions of insulin on cultured adipocytes through ET-1 type B (ETB) receptors; however, the in vivo implications of ETB receptor activation on lipid metabolism and insulin resistance is unknown. We hypothesized that activation of ETB receptors in response to HS intake promotes dyslipidemia and insulin resistance. In normal salt (NS) fed rats, no significant difference in body mass or epididymal fat mass was observed between control and ETB deficient rats. After 2 weeks of HS, ETB-deficient rats had significantly lower body mass and epididymal fat mass compared to controls. Nonfasting plasma glucose was not different between genotypes; however, plasma insulin concentration was significantly lower in ETB-deficient rats compared to controls, suggesting improved insulin sensitivity. In addition, ETB-deficient rats had higher circulating free fatty acids in both NS and HS groups, with no difference in plasma triglycerides between genotypes. In a separate experiment, ETB-deficient rats had significantly lower fasting blood glucose and improved glucose and insulin tolerance compared to controls. These data suggest that ET-1 promotes adipose deposition and insulin resistance via the ETB receptor.
Distinguishing Brans–Dicke–Kerr type naked singularities and black holes with their thin disk electromagnetic radiation properties
Authors: Shahidi Shahab , Harko Tiberiu , Kovács Zoltán
Published: February 2020

The possible existence of naked singularities, hypothetical astrophysical objects, characterized by a gravitational singularity without an event horizon is still an open problem in present day astrophysics. From an observational point of view distinguishing between astrophysical black holes and naked singularities also represents a major challenge. One possible way of differentiating naked singularities from black holes is through the comparative study of thin accretion disks properties around these different types of compact objects. In the present paper we continue the comparative investigation of accretion disk properties around axially-symmetric rotating geometries in Brans–Dicke theory in the presence of a massless scalar field. The solution of the field equations contains the Kerr metric as a particular case, and, depending on the numerical values of the model parameter $$\gamma $$γ, has also solutions corresponding to non-trivial black holes and naked singularities, respectively. Due to the differences in the exterior geometries between black holes and Brans–Dicke–Kerr naked singularities, the thermodynamic and electromagnetic properties of the disks (energy flux, temperature distribution and equilibrium radiation spectrum) are different for these two classes of compact objects, consequently giving clear observational signatures that could discriminate between black holes and naked singularities.
Casimir force between ideal metal plates in a chiral vacuum
Authors: Høye Johan S. , Brevik Iver
Published: February 2020

We calculate the Casimir force between two parallel ideal metal plates when there is an intervening chiral medium present. Making use of methods of quantum statistical mechanics, we show how the force can be found in a simple and compact way. The expression for the force is in agreement with that obtained recently by Jiang and Wilczek (Phys Rev B 99:125403, 2019), in their case with the use of Green function methods.
Interplay of epidemic spreading and strategy-mixed awareness diffusion on multiplex networks
Authors: Kan Jia-Qian , Ma Chuang , Zhang Hai-Feng , Xiang Bing-Bing
Published: February 2020

In this paper, the interplay of epidemic spreading and the strategy-mixed awareness diffusion within the framework of multiplex networks is studied. In the model, epidemics can spread through a physical-contact layer and the awareness can diffuse through a virtual-contact layer. Each node on physical-contact layer is randomly matched one-to-one with a node of virtual-contact layer, but the connectivity is distinct in each of them. In view of the complexity of human behaviors, we assume that the diffusion of awareness is ruled by two mixed contagion dynamics: a fraction [Formula: see text] of individuals adopt the herd-like dynamics and the others follow the epidemic-like dynamics. We analyze the epidemic threshold based on the microscopic Markov chain approach. Meanwhile, combing with the Monte Carlo (MC) simulations, we show that the strategy-mixed awareness diffusion mechanism can enrich the dynamics of epidemic spreading, including the crossover phenomenon of the final epidemic size, the two-stage effect of the local awareness rate, and so forth.
Mapping Road Based on Multiple Features and B-GVF Snake
Authors: Wang Fengping , Li Ying
Published: February 2020

As a significant application in aerial image, road mapping is still a difficult task since roads show complex features caused by the influence of spectral reflectance, shadows and occlusions. To achieve a satisfying result, a new method combing multiple road features and biased gradient vector flow (B-GVF) snake is studied in this paper. First, an exponential function is applied to fuse the color-based and structure-based measure for gaining the saliency maps which is viewed as the candidate region of B-GVF snake; Secondly, the initial road boundary is calculated from the candidate region using a region-growing algorithm, and then an gradient map is produced by an Gaussian filtering function; at last, a normally biased GVF external force is proposed for mapping road edges, which keeps the diffusion along the tangential direction of the isophotes and biases along the normal direction. Experimental results show that the proposed approach has the good performance in Completeness, Correctness, and F-measure comparing with other state-of-the-art methods.
Fault Diagnosis Method for Wind Turbine Gearbox Based on Image Characteristics Extraction and Actual Value Negative Selection Algorithm
Authors: Xu Xiaoli , Liu Xiuli
Published: February 2020

With the development of information theory and image analysis theory, the studies on fault diagnosis methods based on image processing have become a hot spot in the recent years in the field of fault diagnosis. The gearbox of wind turbine generator is a fault-prone subassembly. Its time frequency of vibration signals contains abundant status information, so this paper proposes a fault diagnosis method based on time-frequency image characteristic extraction and artificial immune algorithm. Firstly, obtain the time-frequency image using wavelet transform based on threshold denoising. Secondly, acquire time-frequency image characteristics by means of Hu invariant moment and correlation fusion gray-level co-occurrence matrix of characteristic value, thus, to extract the fault information of the gearing of wind turbine generator. Lastly, diagnose the fault type using the improved actual-value negative selection algorithm. The application of this method in the gear fault diagnosis on the test bed of wind turbine step-up gearbox proves that it is effective in the improvement of diagnosis accuracy.
An Improved Plantar Regional Division Algorithm for Aided Diagnosis of Early Diabetic Foot
Authors: Lian Zuozheng , Wang Haizhen , Chen Mingjun , Li Jingyou
Published: February 2020

The early stages of diabetic foot represent a critical treatment period, but patients show no obvious symptoms. Upon the development into foot ulcers, a risk of amputation exists for which treatment costs are high. In this study, considering the plantar pressure as an important physiological parameter of the foot, we proposed methods to assist the diagnosis of early diabetic foot. Plantar pressure images of early diabetic foot patients were collected and de-noised. An improved automatic regional division algorithm of plantar pressure images was proposed. Laplacian spectrum features were extracted according to the maximum pressure point, pressure center point, and pressure values of the different plantar regions, including plantar shape and tactile features. Finally, based on these data, a support vector classifier was designed and sequential minimal optimization algorithms were used to train the classifier on the plantar pressure data of the left and right foot in 70 subjects to identify early diabetic foot. The results showed that the average recognition rates of the algorithm were high, providing an important reference for the diagnosis of early diabetic foot.
MEMS Inertial Sensor Fault Diagnosis Using a CNN-Based Data-Driven Method
Authors: Gao Tong , Sheng Wei , Zhou Mingliang , Fang Bin , Zheng Liping
Published: February 2020

In this paper, we propose a novel fault diagnosis (FD) approach for micro-electromechanical systems (MEMS) inertial sensors that recognize the fault patterns of MEMS inertial sensors in an end-to-end manner. We use a convolutional neural network (CNN)-based data-driven method to classify the temperature-related sensor faults in unmanned aerial vehicles (UAVs). First, we formulate the FD problem for MEMS inertial sensors into a deep learning framework. Second, we design a multi-scale CNN which uses the raw data of MEMS inertial sensors as input and which outputs classification results indicating faults. Then we extract fault features in the temperature domain to solve the non-uniform sampling problem. Finally, we propose an improved adaptive learning rate optimization method which accelerates the loss convergence by using the Kalman filter (KF) to train the network efficiently with a small dataset. Our experimental results show that our method achieved high fault recognition accuracy and that our proposed adaptive learning rate method improved performance in terms of loss convergence and robustness on a small training batch.
A Review on Design of Multiband Bandpass Filter Using Different DGS Structures to Enhance the Performance
Authors: Kumar Kapil , Dixit Amit , Kala Pradyot , Yadav Savita , Pant Reena
Published: February 2020

In this paper, we discussed about the work done by researchers for the enhancement of performance of a multiband BPF by introducing different defected ground structure (DGS) geometries. A DGS structure on a conventional inductively coupled band pass filter is used to miniaturize the resonator. By introducing a DGS on the transversal dimension of the CPW, it enhances filter performance. The DGS cell also transforms a single band to a multiband BPF by using this structure. The design technique of the filters with the DGS can be explained at very high frequencies in GHz ranges and give very accurate simulated and measured results.
Switched-Capacitor Common-Mode Feedback-Based Fully Differential Operational Amplifiers and its Usage in Implementation of Integrators
Authors: Basu Joydeep , Mandal Pradip
Published: February 2020

For stabilizing the common-mode output voltage of fully differential operational amplifiers, switched-capacitor (SC) type of common-mode feedback (CMFB) is a familiar technique. This is appropriate for implementing high-gain wide-swing low-power op-amps due to its benefits of minimum power consumption, superior linearity across a large amplifier output swing range, and improved feedback loop stability in comparison to continuous-time CMFB. However, the usage of SC-CMFB requires careful attention to some realistic aspects, details of many of which are available in literature. Nonetheless, its adverse effect on the op-amp’s differential-mode gain has not been investigated much. The explanation for this effect is the SC-CMFB-induced equivalent resistive loading, and this is particularly significant in amplifiers like folded cascode which are intended to provide a high gain. This issue of drop in op-amp dc gain because of SC-CMFB, and the consequence on the realization of continuous-time and discrete-time forms of integrators utilizing such amplifiers is the topic of discussion in this paper. Relevant analytical derivations and circuit simulations at the transistor level are provided. A couple of design guidelines and circuit topologies for minimizing the loading-induced gain reduction are also presented.
Quantitative Anderson localization of Schrödinger eigenstates under disorder potentials
Authors: Altmann Robert , Henning Patrick , Peterseim Daniel
Published: February 2020

This paper analyzes spectral properties of linear Schrödinger operators under oscillatory high-amplitude potentials on bounded domains. Depending on the degree of disorder, we prove the existence of spectral gaps among the lowermost eigenvalues and the emergence of exponentially localized states. We quantify the rate of decay in terms of geometric parameters that characterize the potential. The proofs are based on the convergence theory of iterative solvers for eigenvalue problems and their optimal local operator preconditioning by domain decomposition.
Four-Variable Simultaneous Optimization of the Cooling and Acoustic Power with Particle Swarm Optimization
Authors: Chan It Sing , Ghazali Normah Mohd , Zolpakar Nor Atiqah , Mohamad Maziah
Published: February 2020

The low performance of the thermoacoustic refrigerator has made it uncompetitive to currently available refrigeration systems and hence its path towards commercialization is being restricted. Recently, evolutionary algorithm such as genetic algorithm has become popular among researchers in optimizing the performance of the thermoacoustic refrigerator due to its capability to provide a solution with a global maximum or minimum through simultaneous optimization of several objectives. The purpose of this study was to maximize the performance of the thermoacoustic refrigerator using the Multi-Objective Particle Swarm Optimization (MOPSO), an evolutionary optimization tool that has not been tried in this field before. By optimizing the two conflicting objectives which are maximizing the cooling power and minimizing the acoustic power required, simultaneous optimization of inter-dependent controlling parameters has been performed for two, three and four parameters. Comparing with the results of past studies, MOPSO has improved the stack COP by 6.92% compared to the parametric optimization approach and 2.96% higher than the maximum COP achieved by multi-objective genetic algorithm (MOGA) with an optimum COP of 1.39. Also, a maximum cooling power of 10.8 W was obtained. This study has highlighted the potential of MOPSO in providing optimized conditions for conflicting objectives desired for a thermoacoustic system.
Moments of moments of characteristic polynomials of random unitary matrices and lattice point counts
Authors: Assiotis Theodoros , Keating Jonathan P.
Published: February 2020

In this note, we give a combinatorial and noncomputational proof of the asymptotics of the integer moments of the moments of the characteristic polynomials of Haar distributed unitary matrices as the size of the matrix goes to infinity. This is achieved by relating these quantities to a lattice point count problem. Our main result is a new explicit expression for the leading order coefficient in the asymptotic as a volume of a certain region involving continuous Gelfand–Tsetlin patterns with constraints.
Cerebrovascular carbon dioxide reactivity and flow-mediated dilation in young healthy South Asian and Caucasian European men
Authors: Junejo Rehan T. , May Sophie , Alsalahi Sultan , Alali Mohammad , Ogoh Shigehiko , Fisher James P.
Published: February 2020

South Asians living in the United Kingdom have a 1.5-fold greater risk of ischemic stroke than the general population. Impaired cerebrovascular carbon dioxide (CO2) reactivity is an independent predictor of ischemic stroke and cardiovascular mortality. We sought to test the hypothesis that cerebrovascular CO2 reactivity is reduced in South Asians. Middle cerebral artery blood velocity (MCA Vm) was measured at rest and during stepwise changes in end-tidal partial pressure of CO2 ([Formula: see text]) in South Asian ( n = 16) and Caucasian European ( n = 18) men who were young (~20 yr), healthy, and living in the United Kingdom. Incremental hypercapnia was delivered via the open-circuit steady-state method, with stages of 4 and 7% CO2 (≈21% oxygen, nitrogen balanced). Cerebrovascular CO2 reactivity was calculated as the change in MCA Vm relative to the change in [Formula: see text]. MCA Vm was not different in South Asians [59 (9) cm/s, mean (standard deviation)] and Caucasian Europeans [61 (12) cm/s; P > 0.05]. Similarly, cerebrovascular CO2 reactivity was not different between the groups [South Asian 2.53 (0.76) vs. Caucasian European 2.61 (0.81) cm·s−1·mmHg−1; P > 0.05]. Brachial artery flow-mediated dilation was lower in South Asians [5.48 (2.94)%] compared with Caucasian Europeans [7.41 (2.28)%; P < 0.05]; however, when corrected for shear rate no between-group differences in flow-mediated dilation were observed ( P > 0.05). Flow-mediated dilation was not correlated with cerebrovascular CO2 reactivity measures. In summary, cerebrovascular CO2 reactivity and flow-mediated dilation corrected for shear rate are preserved in young healthy South Asian men living in the United Kingdom.

NEW & NOTEWORTHY Previous reports have identified an increased risk of ischemic stroke and peripheral endothelial dysfunction in South Asians compared with Caucasian Europeans. The main finding of this study is that cerebrovascular carbon dioxide reactivity (an independent predictor of ischemic stroke) is not different in healthy young South Asian and Caucasian European men.
Cardiac-specific inactivation of Prdm16 effects cardiac conduction abnormalities and cardiomyopathy-associated phenotypes
Authors: Nam Jeong Min , Lim Ji Eun , Ha Tae Woong , Oh Bermseok , Kang Ji-One
Published: February 2020

A variant in the PRDM16 locus has been correlated with QRS duration in an electrocardiogram genome-wide association study, and the deletion of PRDM16 has been implicated as a causal factor of the dilated cardiomyopathy that is linked to 1p36 deletion syndrome. We aimed to determine how a null mutation of Prdm16 affects cardiac function and study the underlying mechanism of the resulting phenotype in an appropriate mouse model. We used cardiac-specific Prdm16 conditional knockout mice to examine cardiac function by electrocardiography. QRS duration and QTc interval increased significantly in cardiac-specific Prdm16 knockout animals compared with wild-type mice. Further, we assessed cardiomyopathy-associated features by trichrome staining, densitometry, and hydroxyproline assay. Prdm16-null hearts showed greater fibrosis and cardiomyocyte hypertrophy. By quantitative real-time PCR, Prdm16-null hearts upregulated extracellular matrix-related genes ( Ctgf, Timp1) and α-smooth muscle actin ( Acta2), a myofibroblast marker. Moreover, TGF-β signaling was activated in Prdm16-null hearts, as evidenced by increased Tgfb1–3 transcript levels and phosphorylated Smad2. However, the inhibition of TGF-β receptor did not reverse the aberrations in conduction in cardiac-specific Prdm16 knockout mice. To determine the underlying mechanisms, we performed RNA-seq using mouse left ventricular tissue. By functional analysis, Prdm16-null hearts experienced dysregulated expression of ion channel genes, including Kcne1, Scn5a, Cacna1h, and Cacna2d2. Mice with Prdm16-null hearts develop abnormalities in cardiac conduction and cardiomyopathy-associated phenotypes, including fibrosis and cellular hypertrophy. Further, the RNA-seq findings suggest that impairments in ion homeostasis (Ca2+, K+, and Na+) may at least partially underlie the abnormal conduction in cardiac-specific Prdm16 knockout mice.

NEW & NOTEWORTHY This is the first study that describes aberrant cardiac function and cardiomyopathy-associated phenotypes in an appropriate murine genetic model with cardiomyocyte-specific Prdm16-null mutation. It is noteworthy that the correlation of PRDM16 with QRS duration is replicated in a murine animal model and the potential underlying mechanism may be the impairment of ion homeostasis.