bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceived barriers and primary care access experiences among immigrant Bangladeshi men in Canada
Authors: Turin Tanvir C , Rashid Ruksana , Ferdous Mahzabin , Naeem Iffat , Rumana Nahid , Rahman Afsana , Rahman Nafiza , Lasker Mohammad
Published: September 2020

Objective

The study aimed to explore the experience of male members of a rapidly grown community of Bangladeshi immigrants while accessing primary healthcare (PHC) services in Canada.

Design

A qualitative research was conducted among a sample of Bangladeshi immigrant men through a community-based participatory research approach. Focus group discussions were conducted to collect the qualitative data where thematic analysis was applied.

Setting

The focus group discussions were held in various community centres such as individual meeting rooms at public libraries, community halls and so on arranged in collaboration with community organisations while ensuring complete privacy.

Participant

Thirty-eight adults, Bangladeshi immigrant men, living in Calgary were selected for this study and participated in six different focus groups. The sample represents mostly married, educated, Muslim, Bangla speaking, aged over 25 years, full-time or self-employed and living in an urban centre in Canada >5 years.

Result

The focus groups have highlighted long wait time as an important barrier. Long wait at the emergency room, difficulties to get access to general physicians when feeling sick, slow referral process and long wait at the clinic even after making an appointment impact their daily chores, work and access to care. Language is another important barrier that impedes effective communication between physicians and immigrant patients, thus the quality of care. Unfamiliarity with the healthcare system and lack of resources were also voiced that hinder access to healthcare for immigrant Bangladeshi men in Canada. However, no gender-specific barriers unique to men have been identified in this study.

Conclusion

The barriers to accessing PHC services for Bangladeshi immigrant men are similar to that of other visible minority immigrants. It is important to recognise the extent of barriers across various immigrant groups to effectively shape public policy and improve access to PHC.
Association between a 46-SNP Polygenic Risk Score and melanoma risk in Dutch patients with familial melanoma
Authors: Potjer Thomas P , van der Grinten Tara W J , Lakeman Inge M M , Bollen Sander H , Rodríguez-Girondo Mar , Iles Mark M , Barrett Jennifer H , Kiemeney Lambertus A , Gruis Nelleke A , van Asperen Christi J , van der Stoep Nienke
Published: September 2020

Background

Familial clustering of melanoma suggests a shared genetic predisposition among family members, but only 10%–40% of familial cases carry a pathogenic variant in a known high-risk melanoma susceptibility gene. We investigated whether a melanoma-specific Polygenic Risk Score (PRS) is associated with melanoma risk in patients with genetically unexplained familial melanoma.

Methods

Dutch familial melanoma cases (n=418) were genotyped for 46 SNPs previously identified as independently associated with melanoma risk. The 46-SNP PRS was calculated and standardised to 3423 healthy controls (sPRS) and the association between PRS and melanoma risk was modelled using logistic regression. Within the case series, possible differences were further explored by investigating the PRS in relation to (1) the number of primary melanomas in a patient and (2) the extent of familial clustering of melanoma.

Results

The PRS was significantly associated with melanoma risk, with a per-SD OR of 2.12 (95% CI 1.90 to 2.35, p<0.001), corresponding to a 5.70-fold increased risk (95% CI 3.93 to 8.28) when comparing the top 90th to the middle 40–60th PRS percentiles. The mean PRS was significantly higher in cases with multiple primary melanomas than in cases with a single melanoma (sPRS 1.17 vs 0.71, p=0.001). Conversely, cases from high-density melanoma families had a lower (but non-significant) mean PRS than cases from low-density families (sPRS 0.60 vs 0.94, p=0.204).

Conclusion

Our work underlines the significance of a PRS in determining melanoma susceptibility and encourages further exploration of the diagnostic value of a PRS in genetically unexplained melanoma families.
The illness-disease dichotomy and the biological-clinical splitting of medicine
Authors: Tesio Luigi , Buzzoni Marco
Published: September 2020

In a recent paper, Sharpe and Greco (2019) argue that some clinical conditions, such as chronic fatigue syndrome (sometimes called myalgic encephalomyelitis), should be treated by altering the patient's experience and response to symptoms without necessarily searching for an underlying cause. As a result, we should allow for the existence of ‘illnesses without (underlying) diseases’. Wilshire and Ward (2019) reply that this possibility requires unwarranted causal assumptions about the psychosocial origins of conditions not predicted by a disease model. In so doing, it is argued that Sharpe and Greco introduce epistemological and methodological problems with serious medical consequences, for example, patients feel guilt for seeking treatment for illnesses that only exist ‘all in the mind’, and medical researchers are discouraged from looking for more effective treatments of such conditions. We propose a view that integrates the insights of both papers. We abandon both the strict distinction between disease and illness and the naïve unidirectional account of causality that accompanies it. This, we claim, is a step towards overcoming the current harmful tendencies to conceptually separate (1) Symptom management and disease-modifying treatments. (2) Rehabilitative-palliative care and ‘causal’ curing. (3) Most importantly, biomedicine and clinical medicine, where the latter is currently at risk of losing its status as scientific.
Higher risk of major adverse cardiac events after acute myocardial infarction in patients with schizophrenia
Authors: Attar Rubina , Wester Axel , Koul Sasha , Eggert Svend , Polcwiartek Christoffer , Jernberg Tomas , Erlinge David , Andell Pontus
Published: September 2020

Background

Patients with schizophrenia are a high-risk population due to higher prevalences of cardiovascular risk factors and comorbidities that contribute to shorter life expectancy.

Purpose

To investigate patients with and without schizophrenia experiencing an acute myocardial infarction (AMI) in relation to guideline recommended in-hospital management, discharge medications and 5-year major adverse cardiac events (MACE: composite of all-cause mortality, rehospitalisation for reinfarction, stroke or heart failure).

Methods

All patients with schizophrenia who experienced AMI during 2000–2018 were identified (n=1008) from the nationwide Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registry and compared with AMI patients without schizophrenia (n=2 85 325). Kaplan-Meier survival curves and multivariable Cox regression models were used to compare the populations.

Results

Patients with schizophrenia presented with AMI approximately 10 years earlier (median age 64 vs 73 years), and had higher prevalences of diabetes, heart failure and chronic obstructive pulmonary disease. They were less likely to be invasively investigated or discharged with aspirin, P2Y12 inhibitors, ACE inhibitors/angiotensin II receptor blockers, beta-blockers and statins (all p<0.005). AMI patients with schizophrenia had higher adjusted risk of MACE (aHR=2.05, 95% CI 1.63 to 2.58), mortality (aHR=2.38, 95% CI 1.84 to 3.09) and hospitalisation for heart failure (aHR=1.39, 95% CI 1.04 to 1.86) compared with AMI patients without schizophrenia.

Conclusion

Patients with schizophrenia experienced an AMI almost 10 years earlier than patients without schizophrenia. They less often underwent invasive procedures and were less likely to be treated with guideline recommended medications at discharge, and had more than doubled risk of MACE and all-cause mortality. Improved primary and secondary preventive measures, including adherence to guideline recommendations, are warranted and may improve outcome.
Orthostatic hearing loss: audiovestibular manifestations of spontaneous intracranial hypotension
Authors: Schon Frederick , Karunakaran Arun , Shanmuganathan Sarah , Nitkunan Arani
Published: September 2020

A 36-year-old woman with severe postural headaches caused by spontaneous intracranial hypotension developed bilateral hearing loss. Her hearing loss varied in severity and also at times affected one ear more than the other. She noticed her hearing returned to normal on lying flat, and this was confirmed on audiometry. Her hearing fully recovered after treatment with blood patches. Audiovestibular symptoms affect up to 70% of people with spontaneous intracranial hypotension but are probably under-reported. Cerebrospinal fluid and inner ear fluids are related in two separate channels: the vestibular and the cochlear aqueducts. We discuss their role in the postural hearing loss of spontaneous intracranial hypotension.
Diversity and community structure of ammonia-oxidizing archaea in rhizosphere soil of four plant groups in Ebinur Lake wetland
Authors: Chen Ting , Hu Wenge , He Shuaibing , Zhang Xue , Niu Yanhui
Published: September 2020

The aim of this study was to reveal the differences in the community structure of ammonia-oxidizing archaea (AOA) between rhizosphere and non-rhizosphere soil, to provide a theoretical basis for further study on the relationship between halophyte rhizosphere soil microorganisms and salt tolerance. The results of diversity and community structure showed that the diversity of the AOA community in rhizosphere soil of Reeds was higher than that in non-rhizosphere soil in spring and lower than that in non-rhizosphere soil in summer and autumn. In summer, the diversity of rhizosphere soil of Karelinia caspica was higher than that of non-rhizosphere soil and lower than that of non-rhizosphere soil in spring and autumn. The diversity of rhizosphere soil of Halocnemum strobilaceum in 3 seasons was lower than that in non-rhizosphere soil. The diversity of rhizosphere soil of Salicornia was higher than that in non-rhizosphere soil in 3 seasons. In addition, the relative abundance of AOA in rhizosphere soil of 4 plants was higher than that in non-rhizosphere soil. The AOA community in all soil samples was mainly concentrated in Crenarchaeota and Thaumarchaeota. Redundancy analysis results showed salinity, soil water moisture, pH, and soil organic matter were important factors affecting the differentiation of AOA communities.
Vacuum solutions in the Einstein–Aether Theory
Authors: Campista M. , Chan R. , da Silva M.F.A. , Goldoni O. , Satheeshkumar V.H. , Villas da Rocha Jaime F.
Published: September 2020

The Einstein–Aether (EA) theory belongs to a class of modified gravity theories characterized by the introduction of a time-like unit vector field called aether. In this scenario, a preferred frame arises as a natural consequence of a broken Lorentz invariance. In the present work, we have obtained and analyzed some exact solutions allowed by this theory for two particular cases of a perfect fluid, both with Friedmann–Lemaître–Robertson–Walker symmetry: (i) a fluid with constant energy density (p = –ρ0) and (ii) a fluid with zero energy density (ρ0 = 0) corresponding to the vacuum solution with and without cosmological constant (Λ), respectively. Our solutions show that the EA and general relativity (GR) theories only differ in coupling constants. This difference is clearly shown because of the existence of singularities that are not in GR theory. This characteristic appears in the solutions with p = –ρ0 as well as with ρ0 = 0, where this last one depends only on the aether field. Furthermore, we consider the term of the EA theory in the Raychaudhuri equation and discuss the meaning of the strong energy condition in this scenario and found that this depends on the aether field. The solutions admit an expanding or contracting system. Bounce, singular, constant, and accelerated expansion solutions were also obtained, exhibiting the richness of the EA theory from the dynamic point of view of a collapsing system or of a cosmological model. The analysis of energy conditions, considering an effective fluid, shows that the term of the aether contributes significantly for the accelerated expansion of the system for the case in which the energy density is constant. On the other hand, for the vacuum case (ρ0 = 0), the energy conditions are all satisfied for the aether fluid.
The cross section of $$e^+e^-\rightarrow \Lambda \overline{\Sigma }{}^0+\text {c.c.}$$ as a litmus test of isospin violation in the decays of vector charmonia into $$\Lambda \overline{\Sigma }{}^0+\text {c.c.}$$
Authors: Ferroli Rinaldo Baldini , Mangoni Alessio , Pacetti Simone
Published: September 2020

Under the aegis of isospin conservation, the amplitudes in Born approximation, i.e., considering the only one-photon-exchange mechanism, of the decay $$\psi \rightarrow \Lambda \overline{\Sigma }{}^0+\text {c.c.}$$

ψ
→
Λ

Σ
¯

0

+
c.c.

, where $$\psi $$
ψ
is a vector charmonium, and of the reaction $$e^+e^-\rightarrow \Lambda \overline{\Sigma }{}^0+\text {c.c.}$$

e
+

e
-

→
Λ

Σ
¯

0

+
c.c.

at the $$\psi $$
ψ
mass, are parametrized by the same electromagnetic coupling. It follows that, the modulus of such a coupling can be extracted from the data on the two observables: the decay branching fraction and the annihilation cross section. By considering the first two vector charmonia, $$J/\psi $$

J
/
ψ

and $$\psi (2S)$$

ψ
(
2
S
)

, it is found that, especially in the case of $$\psi (2S)$$

ψ
(
2
S
)

, there is a substantial discrepancy between the values of the modulus of the same electromagnetic coupling extracted from the branching ratio and the cross section. We propose, as a possible explanation for such a disagreement, the presence in the decay amplitude of isospin-violating contributions driven by two different mechanisms, that, however, appear to be more favored in the $$\psi (2S)$$

ψ
(
2
S
)

than in the $$J/\psi $$

J
/
ψ

decays.
Quadruply charmed dibaryons as heavy quark symmetry partners of the DDK bound state
Authors: Wu Tian-Wei , Liu Ming-Zhu , Geng Li-Sheng , Hiyama Emiko , Valderrama Manuel Pavon , Wang Wen-Ling
Published: September 2020

Both unitary chiral theories and lattice QCD simulations show that the DK interaction is attractive and can form a bound state, namely, $$D^*_{s0}(2317)$$

D

s
0

∗

(
2317
)

. Assuming the validity of the heavy antiquark–diquark symmetry, the $$\Xi _{cc}{\bar{K}}$$

Ξ

cc

K

¯

interaction is the same as the DK interaction, which implies the existence of a $$\Xi _{cc}{\bar{K}}$$

Ξ

cc

K

¯

bound state with a binding energy of $$49-64$$

49
-
64

MeV. In this work, we study whether a $$\Xi _{cc}\Xi _{cc}{\bar{K}}$$

Ξ

cc

Ξ

cc

K

¯

three-body system binds. The $$\Xi _{cc}\Xi _{cc}$$

Ξ

cc

Ξ

cc

interaction is described by exchanging $$\pi $$
π
, $$\sigma $$
σ
, $$\rho $$
ρ
, and $$\omega $$
ω
mesons, with the corresponding couplings related to those of the NN interaction via the quark model. We indeed find a $$\Xi _{cc}\Xi _{cc}{\bar{K}}$$

Ξ

cc

Ξ

cc

K

¯

bound state, with quantum numbers $$J^P=0^-$$

J
P

=

0
-

, $$I=\frac{1}{2}$$

I
=

1
2

, $$S=1$$

S
=
1

and $$C=4$$

C
=
4

, and a binding energy of 80–118 MeV. With the same formalism, we find that the $$\Xi _{cc}\bar{\Xi }_{cc}{\bar{K}}$$

Ξ

cc

Ξ

¯

cc

K

¯

system also binds, yielding a $$I(J^P)=\frac{1}{2}(0^+)$$

I

(

J
P

)

=

1
2

(

0
+

)

state and a $$\frac{1}{2}(1^+)$$

1
2

(

1
+

)

state with binding energies of 56–68 MeV and 56–67 MeV respectively. As a byproduct, we show the existence of a $$NN{\bar{K}}$$

N
N

K

¯

state with a binding energy of 35–43 MeV, consistent with the results of other theoretical works and experimental data, which serves as a consistency check on the predicted $$\Xi _{cc}\Xi _{cc}{\bar{K}}$$

Ξ

cc

Ξ

cc

K

¯

bound state.
Impact of Information Sharing Modes on the Dual-Channel Closed Loop Supply Chains Under Different Power Structures
Authors: Wang Tong-Yuan , Wang Zeng-Qiang , He Peng
Published: September 2020

In this paper, we develop game-theoretic models regarding dual-channel closed loop supply chain (CLSC) to identify whether the retailer has incentives to share private demand information with the manufacturer and/or the collector, and how different information sharing modes influence the chain members’ operational performances under different channel power structures. Given that the collector recycles used products, four information sharing modes (i.e., no information sharing, information sharing with the manufacturer, information sharing with the collector, and information sharing with both the manufacturer and the collector) are examined in the manufacturer Stackelberg and collector Stackelberg supply chains, respectively. We find that the retailer’s sharing information behavior always benefits for the collector and the entire supply chain. The retailer, however, has no incentive to share demand information voluntarily. As for the manufacturer, the retailer’s sharing information behavior always benefits him in the collector Stackelberg scenario, while may hurt him in the manufacturer Stackelberg scenario. Furthermore, the impact of channel power structure in the four information sharing modes is also discussed. The results show that the manufacturer Stackelberg model or the collector Stackelberg model may be the better structure for chain members depending on the retailer’s demand forecast accuracy.
A Comparison of Nonlinear Bending and Vibration of Hybrid Metal/CNTRC Laminated Beams with Positive and Negative Poisson’s Ratios
Authors: Yu Yin , Shen Hui-Shen
Published: September 2020

Carbon nanotube reinforced composite (CNTRC) is one of the novel classes of advanced composite materials. This paper investigates the nonlinear bending and nonlinear vibration responses of hybrid laminated beams made of CNTRC layers bonded with metal layers on the top and bottom surfaces. We proposed a hybrid metal/CNTRC laminated beam for which out-of-plane Poisson’s ratio is negative. The effective material properties of CNTRC layers are graded in a piece-wise pattern across the thickness of the beam. The material properties of both CNTRC layer and metal layer are temperature dependent. The beams are rested on an elastic foundation and are located in thermal environments. Reddy’s higher-order beam model is used to establish the motion equations of the hybrid metal/CNTRC laminated beam. The motion equations include the von Kármán geometric nonlinearity, the thermal effects and the beam-foundation interaction. By employing a two-step perturbation approach, the bending and nonlinear vibration solutions are obtained. A comparison of nonlinear responses of hybrid metal/CNTRCl laminated beams with positive and negative Poisson’s ratios (NPRs) under different thermal environmental conditions is carried out and discussed in detail.
Temperature-Dependent Vibration of Various Types of Sandwich Beams with Porous FGM Layers
Authors: Rahmani Mohsen , Dehghanpour Sajjad
Published: September 2020

By using a high order sandwich beams theory which is modified by considering the transverse flexibility of the core, free vibration characteristics of two models of sandwich beams are studied in this paper. In type-I, functionally graded layers coat a homogeneous core, and in type-II, an FG core is covered by homogeneous face sheets. To increase the accuracy of the model of the FGM properties, even and uneven porosity distributions are applied, and all materials are considered temperature-dependent. Nonlinear Lagrange strain and thermal stresses of the face sheets and in-plane strain of the core are considered. To obtain the governing equations of motion, Hamilton’s principle is used and a Galerkin method is used to solve them for simply supported and clamped boundary conditions. To verify the results of this study, they are compared with the results of literatures. Also, the effect of variation of temperature, some geometrical parameters and porosities on the frequency are studied.
Control of Magnetoelectric Load to Maintain Stable Compression Ratio for Free Piston Linear Engine Systems
Authors: Yang Bo , Yuan Chenheng , Li Jiahui
Published: September 2020

The free piston linear engine system (FPLE) is considered as a promising powerplant, which has the advantages such as compact structure, short transfer path and variable compression ratio (CR) because the crank connecting rod is removed. However, the absence of crank-connecting rod inevitably produces uncertainty to the stable operation of the FPLE. A control system of the piston motion regulating for the FPLE is necessary. In this paper, the nonlinear dynamic model simulating the piston motion in a dual-piston FPLE is derived based on energy and force balance. The feasibility of the dynamic model is verified by experiment and simulation results. Based on instability mechanism analysis, a magnetoelectric load controller with motion stroke feedback is designed to maintain the piston position in a predefined CR by regulating the magnetoelectric force. The proposed magnetoelectric load controller is shown to have good control performance for the FPLE. The piston is always stabilized at the predefined position after a short adjustment time. The time of eliminating disturbance for the operation process is less than the start process. Furthermore, the increase in disturbance will result in the increase of time for adjustment.
Numerical and Experimental Analyses of Free and Forced Vibration of Thin-Walled Beams
Authors: Jrad Wassim , Mohri Foudil , Robin Guillaume , Daya El Mostafa
Published: September 2020

The flexural–torsional vibration behavior of unrestrained and braced thin-walled beams is investigated by experimental and finite elements approaches. In the experimental part, tests in free and forced vibrations of thin walled beams with arbitrary sections are analyzed. By the help of an instrumental hammer test and a shaker machine, the natural frequencies and the response spectra of the beams are extracted in the range 1–400[Formula: see text]Hz. Beam displacements are measured by some accelerometer transducers. The behavior is also investigated by the finite element method. In mesh process, 3D beams are adopted and an additional DOF is affected to the warping. The model is implemented in a home-made model. The numerical and experimental results are compared to numerical simulations of a commercial code. Test results and numerical simulations of the present model agree well. The model seems to be accurate especially in the presence of higher vibration and coupled modes.
Monogenic reciprocal trinomials and their Galois groups
Authors: Jones Lenny
Published: September 2020

Let [Formula: see text] denote the cyclic group of order [Formula: see text], and let Hol([Formula: see text]) denote the holomorph of [Formula: see text]. In this paper, for any odd integer [Formula: see text], we find necessary and sufficient conditions on an integer [Formula: see text], with [Formula: see text], such that [Formula: see text] is irreducible over [Formula: see text]. When [Formula: see text] is prime and [Formula: see text] is irreducible, we show that the Galois group over [Formula: see text] of [Formula: see text] is isomorphic to either Hol([Formula: see text]) or Hol([Formula: see text]), depending on whether there exists [Formula: see text] such that [Formula: see text]. Finally, we prove that there exist infinitely many positive integers [Formula: see text] such that [Formula: see text] is irreducible over [Formula: see text] and that [Formula: see text] is a basis for the ring of integers of [Formula: see text], where [Formula: see text].
Analysis of achievable distances of BB84 and KMB09 QKD protocols
Authors: Khan Muhammad Mubashir , Arfeen Asad , Ahsan Usama , Ahmed Saneeha , Mumtaz Tahreem
Published: September 2020

Quantum key distribution (QKD) is a proven secured way to transmit shared secret keys using quantum particles. Any adversarial attempt to intercept and eavesdrop secret key results in generating errors alerting the legitimate users. Since QKD is constrained by quantum mechanics principles, the practical transmission of the key at a greater distance is an issue. In this paper, we discover and analyze the key factors associated with transmission media, hardware components and protocol implementation of the QKD system that causes hindrance in distance range. Practical implementation of BB84 and KMB09 protocols is discussed to determine the achievable distance given current technology. We find that by using ultra low loss fiber, short-pulse laser and superconducting nanowire single photon detector the maximum achievable distance for both of the quantum protocols is 250[Formula: see text]km.
Phase operators and phase states associated with the su(n + 1) Lie algebra
Authors: Hajji S. , Maroufi B. , Mansour M. , Daoud M.
Published: September 2020

The main aim of this work is to build unitary phase operators and the corresponding temporally stable phase states for the [Formula: see text] Lie algebra. We first introduce an irreducible finite-dimensional Hilbertian representation of the [Formula: see text] Lie algebra which is suitable for our purpose. The phase operators obtained from the [Formula: see text] generators are defined and the phase states are derived as eigenstates associated to these unitary phase operators. The special cases of [Formula: see text] and [Formula: see text] Lie algebras are also explicitly investigated.
The isodominism class of the graphs
Authors: Tolue Behnaz , Rafiei Amin
Published: September 2020

In this paper, the new concept [Formula: see text]-isodominism between two graphs is introduced, where [Formula: see text] is a positive integer. The [Formula: see text]-isodominism is a pair of the graph isomorphism which depends on the smallest [Formula: see text]-dominating sets. By this tool, a graph with one vertex, complete graphs, wheels and stars are in the same [Formula: see text]-isodominism class. Furthermore, some results about the [Formula: see text]-isodominism classes of paths, cycles and star polygon are presented.
A multiple parallel mediation between transformational leadership and project-based performance — A process model
Authors: Ul Haq Inzamam , Paracha Adil Tahir , Shakeel Wajid
Published: September 2020

Purpose: Our purpose to write this paper is to analyze how VRIO mediates the relationship between transformational leadership and project performance by examining the direct and mediated relationships on project performance outcomes. This study combined the two dynamic concepts: project management and strategic management with the support of both literatures.

Design/methodology/approach: The resource-based view is operationalized to analyze the effect of project management assets and characteristics to gain a competitive edge in the industry and market as whole. The parallel mediation has been analyzed applying VRIO framework between transformational leadership and project performance, moreover its impact on firm-based performance is supported by the literature.

Finding: Transformational leadership scientifically predicts project performance. Results demonstrated two mediations to be accepted (Rare resources and Valuable Resources) however, both got rejected in the Pakistani context.

Research Limitations: The sample size considered for our study was only 256 and data were gathered from comparatively small software companies due to the fact that software companies in Islamabad and Rawalpindi are small comparatively in India or USA.

Practical Implication: The research contributions are quite interesting; these would be followed by the transformational leaders in software industry to attain competitive edge in market using project assets characteristics.

Originality/value: A useful combination of transformational leadership and resource-based view theory is used to reach project potential and improvements to sustain in competition.
Continuous Empirical Wavelets Systems
Authors: Gilles Jérôme
Published: September 2020

The recently proposed empirical wavelet transform was based on a particular type of filter. In this paper, we aim to propose a general framework for the construction of empirical wavelet systems in the continuous case. We define a well-suited formalism and then investigate some general properties of empirical wavelet systems. In particular, we provide some sufficient conditions to the existence of a reconstruction formula. In the second part of the paper, we propose the construction of empirical wavelet systems based on some classic mother wavelets.
Probabilistic Modeling for Frequency Vectors Using a Flexible Shifted-Scaled Dirichlet Distribution Prior
Authors: Zamzami Nuha , Bouguila Nizar
Published: September 2020

Burstiness and overdispersion phenomena of count vectors pose significant challenges in modeling such data accurately. While the dependency assumption of the multinomial distribution causes its failure to model frequency vectors in several machine learning and data mining applications, researchers found that by extending the multinomial distribution to the Dirichlet Compound multinomial (DCM), both phenomena modeling can be addressed. However, Dirichlet distribution is not the best choice, as a prior, given its negative-correlation and equal-confidence requirements. Thus, we propose to use a flexible generalization of the Dirichlet distribution, namely, the shifted-scaled Dirichlet, as a prior to the multinomial, which grants the model a capability to better fit real data, and we call the new model the Multinomial Shifted-Scaled Dirichlet (MSSD). Given that the likelihood function plays a key role in statistical inference, e.g., in maximum likelihood estimation and Fisher information matrix investigation, we propose to improve the efficiency of computing the MSSD log-likelihood by approximating its function based on Bernoulli polynomials where the log-likelihood function is computed using the proposed mesh algorithm. Moreover, given the sparsity and high-dimensionality nature of count vectors, we propose to improve its computation efficiency by approximating the novel MSSD as a member of the exponential family of distribution, which we call EMSSD. The clustering is based on mixture models, and for learning a model, selection approach is seamlessly integrated with the estimation of the parameters. The merits of the proposed approach are validated via challenging real-world applications such as hate speech detection in Twitter, real-time recognition of criminal action, and anomaly detection in crowded scenes. Results reveal that the proposed clustering frameworks offer a good compromise between other state-of-the-art techniques and outperform other approaches previously used for frequency vectors modeling. Besides, comparing to the MSSD, the approximation EMSSD has reduced the computational complexity in high-dimensional feature spaces.
REMIAN
Authors: Ma Qian , Gu Yu , Lee Wang-Chien , Yu Ge , Liu Hongbo , Wu Xindong
Published: September 2020

Missing value (MV) imputation is a critical preprocessing means for data mining. Nevertheless, existing MV imputation methods are mostly designed for batch processing, and thus are not applicable to streaming data, especially those with poor quality. In this article, we propose a framework, called
Real-time and Error-tolerant Missing vAlue ImputatioN
(REMAIN), to impute MVs in poor-quality streaming data. Instead of imputing MVs based on
all
the observed data, REMAIN first initializes the MV imputation model based on
a-RANSAC
which is capable of detecting and rejecting anomalies in an efficient manner, and then incrementally updates the model parameters upon the arrival of new data to support real-time MV imputation. As the correlations among attributes of the data may change over time in unforseenable ways, we devise a
deterioration detection
mechanism to capture the deterioration of the imputation model to further improve the imputation accuracy. Finally, we conduct an extensive evaluation on the proposed algorithms using real-world and synthetic datasets. Experimental results demonstrate that REMAIN achieves significantly higher imputation accuracy over existing solutions. Meanwhile, REMAIN improves up to one order of magnitude in time cost compared with existing approaches.
CQF Magma package
Authors: Koprowski Przemysław
Published: September 2020

CQF is a free, open-source Magma package for doing computations in quadratic forms theory. We present some selected ingredients of the package.
The Book Review Column
Authors: Green Frederic
Published: September 2020

In this column, we review these three books: 1. The Problem With Software: Why Smart Engineers Write Bad Code, by Adam Barr. Answers to a question many of us have probably asked; and what we can do about it. Review by Shoshana Marcus. 2. Elements of Parallel Computing, by Eric Aubanel. A textbook on the underpinnings of this important and fascinating area of computer science. Review by Michele Amoretti. 3. Theorems of the 21st Century: Volume I, by Bogdan Grechuk. The background, context, and statement of numerous important (accessible) mathematical theorems from the past 20 years. Review by William Gasarch.
Technical Report Column
Authors: Kelley Dean
Published: September 2020

Welcome to the Technical Reports Column. If your institution publishes technical reports that you'd like to have included here, please contact me at the email address above.
The Busy Beaver Frontier
Authors: Aaronson Scott
Published: September 2020

The Busy Beaver function, with its incomprehensibly rapid growth, has captivated generations of computer scientists, mathematicians, and hobbyists. In this survey, I o er a personal view of the BB function 58 years after its introduction, emphasizing lesser-known insights, recent progress, and especially favorite open problems. Examples of such problems include: when does the BB function rst exceed the Ackermann function? Is the value of BB(20) independent of set theory? Can we prove that BB(n + 1) > 2BB(n) for large enough n? Given BB(n), how many advice bits are needed to compute BB(n + 1)? Do all Busy Beavers halt on all inputs, not just the 0 input? Is it decidable, given n, whether BB(n) is even or odd?
Database Theory Column
Authors: Tao Yufei
Published: September 2020

The 39th edition of the ACM SIGMOD-SIGACT-SIGAI Symposium on Principles of Database Systems (PODS) was planned to take place from June 14 to June 19, 2020, in Portland, OR, USA. Due to the coronavirus pandemic, it was organized instead as a virtual (online) conference on the same dates. As in previous years, the symposium was held jointly with the ACM International Conference on Management of Data (SIGMOD). PODS focuses on the theoretical aspects of data management systems, and the co-location with SIGMOD stimulates interaction between theory-oriented and system-oriented research.
Electrodeposition of Single γ-phase Zn–Ni Alloy from Deep Eutectic Solvents using Metal Oxides as Precursors
Authors: Ren Xiangyu , Tang Jie , Xu Cunying , Wang Shuxian , Li Jianru , Lu Jingling , Hua Yixin , Zhang Qibo , Ru Juanjian
Published: September 2020

The electrodeposition behavior of Zn–Ni alloy on a Cu electrode has been studied in the choline chloride-urea-ethylene glycol (ChCl-urea-EG) based deep eutectic solvent (DES). The nickel and zinc sources are introduced into the solvent by the dissolution of nickel oxide (NiO) and zinc oxide (ZnO), respectively. Cyclic voltammetry indicates that the electroreduction of Ni(II) or Zn(II) species in the DES is a diffusion-controlled process and the diffusion coefficient of Zn(II) species is an order of magnitude larger than that of Ni(II) species. Under the examined condition, the anomalous codeposition of Zn–Ni alloy is observed, which is different from normal codeposition of Zn–Ni alloy in similar DESs using metal chlorides as precursor. The deposition potential is found to play an important role in controlling the composition and surface morphology of the resultant Ni-Zn alloys. The phase structure of the deposits depends on the Ni content, and changes from a mixture of η-phase and γ-phase to single γ-phase with (411) plane orientation. A mechanism for this electrodeposition process has been proposed on the basis of the formation of complex ions [NiO·urea·Cl]−, [ZnO∙urea·Cl]− and [ChCl·O·urea]2− in ChCl-urea-EG-ZnO-NiO electrolyte during the electrodeposition, emphasizing that the metal oxides were dissolve in DES by forming metal complex ions, the cathodic reduction of metal complex ions generates complex ions [ChCl·O·urea]2− with alloys (NixZny), and [ChCl·O·urea]2− is oxidized to release O2 at anode.
All-Dry Synthesis of Single Crystal NMC Cathode Materials for Li-Ion Batteries
Authors: Zheng Lituo , Bennett J. Craig , Obrovac M. N.
Published: September 2020

Single crystal (SC) cathode materials with a layered structure are considered to be state-of-the-art for lithium ion batteries. However, their production involves many steps and can produce large amounts of wastewater. Here we report an all-dry method for making SC cathode materials, with LiNi0.6Mn0.2Co0.2O2 (SC-NMC) used as a specific example. It was found that a SC-NMC precursor in the form of a previously unobserved rock-salt (Ni, Mn, Co)O solid solution phase can be made phase pure by ball milling. This demonstrates that precursors with atomic scale mixing can be achieved by dry methods. It is furthermore shown that large precursor particle sizes are not necessary to form large SC-NMC particles, as is commonly believed. Instead, large crystallites could just as easily be made from submicron precursors by adjusting the sintering time in air. As a result, highly crystalline SC-NMC with precisely controlled average crystallite sizes ranging from ∼2–10 μm could be made from submicron precursor powders made using an all-dry process.
Effect of Surface Oxygen Concentration on Wafer Strength in Floating Zone Si Wafers
Authors: Fujise Jun , Ko Bonggyun , Ono Toshiaki , Tanaka Masaki
Published: September 2020

The critical stress behavior of low-oxygen-concentration silicon wafers was elucidated by measuring the critical stress of slip generated owing to scratches using the high-temperature three-point bending test method. It is well known that floating zone (FZ) wafers with low oxygen concentrations tend to easily cause slips from dislocation sources such as scratches. The first point observed in the study is that the critical shear stress of FZ wafers had no temperature dependence above 973 K, which may suggest the presence of long-range obstacles for dislocation motion. The second point is that slip generation from scratches was less likely to occur when oxygen atoms were inwardly diffused into the wafer surface by high-temperature thermal treatment. These results will contribute to solving the problem of slip generation from backside scratches, often created during the insulated gate bipolar transistor manufacturing process in which FZ wafers are used.
Comparison of two formats of journal club for postgraduate students at two centers in developing critical appraisal skills
Authors: Kaur Manpreet , Sharma Hanjabam B. , Kaur Simran , Sharma Ratna , Sharma Renuka , Kapoor Raj , Deepak Kishore K.
Published: September 2020

Journal club (JC) is an integral part of postgraduate medical education. Although several innovations have been attempted to improve its effectiveness, the influence of the number of sessions remains unexplored. The current study investigated the effect of the number of sessions (one vs. four) of conduction of journal club on critical appraisal skills of postgraduate students at two institutions. A quasi-experimental study was conducted comparing the effectiveness of JC in a one- versus four-session JC format using two objective tests: Critical Appraisal Skills Test (CAST) and Population, Intervention, Comparison, Outcome (PICO) score. The degree of changes (pre-JC vs. post-JC session) after each format exposure, association of prescores to postscores, and correlation between the CAST and PICO scores were discerned. CAST score was higher in the four-session format ( P = 0.03), whereas PICO score increased in the single-session format of JC ( P = 0.03). Also, the change in CAST score was higher in the four-session versus single-session JC format ( P = 0.04). We conclude that a four-session format of JC is more effective in augmenting critical appraisal skills of postgraduate students, whereas a single session is sufficient for improving factual knowledge.
From initial segment to cauda: a regional characterization of mouse epididymal CD11c+ mononuclear phagocytes based on immune phenotype and function
Authors: Mendelsohn A. C. , Sanmarco L. M. , Spallanzani R. G. , Brown D. , Quintana F. J. , Breton S. , Battistone M. A.
Published: September 2020

Successful sperm maturation and storage rely on a unique immunological balance that protects the male reproductive organs from invading pathogens and spermatozoa from a destructive autoimmune response. We previously characterized one subset of mononuclear phagocytes (MPs) in the murine epididymis, CX3CR1+ cells, emphasizing their different functional properties. This population partially overlaps with another subset of understudied heterogeneous MPs, the CD11c+ cells. In the present study, we analyzed the CD11c+ MPs for their immune phenotype, morphology, and antigen capturing and presenting abilities. Epididymides from CD11c-EYFP mice, which express enhanced yellow fluorescent protein (EYFP) in CD11c+ MPs, were divided into initial segment (IS), caput/corpus, and cauda regions. Flow cytometry analysis showed that CD11c+ MPs with a macrophage phenotype (CD64+ and F4/80+) were the most abundant in the IS, whereas those with a dendritic cell signature [CD64− major histocompatibility complex class II (MHCII)+] were more frequent in the cauda. Immunofluorescence revealed morphological and phenotypic differences between CD11c+ MPs in the regions examined. To assess the ability of CD11c+ cells to take up antigens, CD11c-EYFP mice were injected intravenously with ovalbumin. In the IS, MPs expressing macrophage markers were most active in taking up the antigens. A functional antigen-presenting coculture study was performed, whereby CD4+ T cells were activated after ovalbumin presentation by CD11c+ epididymal MPs. The results demonstrated that CD11c+ MPs in all regions were capable of capturing and presenting antigens. Together, this study defines a marked regional variation in epididymal antigen-presenting cells that could help us understand fertility and contraception but also has larger implications in inflammation and disease pathology.
Consensus of Second-Order Multiagent Systems with Directed Signed Networks and Communication Delays
Authors: Pei Huiqin , Lai Qiang , Li Guang
Published: September 2020

This paper is concerned with the consensus problem for second-order multiagent systems (MASs) with directed signed networks and local communication delays. First, under a strongly connected directed graph, some properties for signed digraph and the model of second-order MASs are provided. A distributed nonlinear consensus control protocol is proposed for implementing consensus of second-order MASs with signed digraph and communication delay. Then, for structurally balanced and unbalanced networks, the consensus of second-order MASs with directed signed networks and local delays is proved via the Lyapunov method and Barbalat lemma. Simulation examples are given to demonstrate the effectiveness of our results.
A Hybrid Method for Ultrashort-Term Wind Power Prediction considering Meteorological Features and Seasonal Information
Authors: Zhou Baobin , Liu Che , Li Jianjing , Sun Bo , Yang Jun , Arpino Fausto
Published: September 2020

High-precision wind power prediction is important for the planning, economics, and security maintenance of a power grid. Meteorological features and seasonal information are strongly related to wind power prediction. This paper proposes a hybrid method for ultrashort-term wind power prediction considering meteorological features (wind direction, wind speed, temperature, atmospheric pressure, and humidity) and seasonal information. The wind power data are decomposed into stationary subsequences using the ensemble empirical mode decomposition (EEMD). The principal component analysis (PCA) is used to reduce the redundant meteorological features and the algorithm complexity. With the stationary subsequences and extracted meteorological features data as inputs, the long short-term memory (LSTM) network is used to complete the wind power prediction. Finally, the seasonal autoregressive integrated moving average (SARIMA) is innovatively used to fit seasonal features (quarterly and monthly) of wind power and reconstruct the prediction results of LSTM. The proposed method is used to predict 15-minute wind power. In this study, three datasets were collected from a windfarm in Laizhou to validate the prediction performance of the proposed method. The experimental results showed that the prediction accuracy was significantly improved when meteorological features were considered and further improved with seasonal correction.
The Character and Economic Preference of City Network of China: A Study Based on the Chinese Global Fortune 500 Enterprises
Authors: Zhao Xinzheng , Su Jing , Chao Jing , Liu Xiaoqiong , Li Tongsheng , Rui Yang , Yang Jun
Published: September 2020

Based on the data of Chinese enterprises that entered the Fortune 500 list in 2015, this paper utilizes the eclectic model to construct the inter-city association network. Using the network analysis method, the spatial connection characteristics of 311 inter-city networks at prefecture level and above and 20 urban agglomerations networks in China are examined, respectively. The research found the following: (1) the overall connectivity of city network is poor, the centripetal concentration is strong, and the network is not complete. The city network structure shows three tendencies, with a concentration in political centers, a concentration in coastal areas, and a concentration in resource-based cities. The external economic dependence of each node city in national city network is high, and the city network structure has distinctly flattening characteristics. (2) Network function of cities is obviously different in multiscale region. Large cities and regional centers have more balanced function systems than the small- and medium-sized cities do. (3) The network of urban agglomerations is characterized by decentralization of power, differentiation of status, and dependence on external connections. The radiation effect of three major urban agglomerations in coastal China is strong, but the radiation effect of other urban agglomerations needs to be strengthened. (4) Both city networks and agglomeration economies have positive impact on economic growth of the city. The economic performance of city networks is differentiated between urban agglomeration cities and nonurban agglomeration cities, as well as between cities of different scale levels. This study provides new evidence for understanding the spatial relations and expansion of Chinese city networks.