bluuebunny/crossref_metadata_2025 huggingface dataset:
Exact Solution of the Startup Electroosmotic Flow of Generalized Maxwell Fluids in Triangular Microducts
Authors: Akyildiz F. Talay , Siginer Dennis A.
Published: April 2021

The unsteady electroosmotic flow of generalized Maxwell fluids in triangular microducts is investigated. The governing equation is formulated with Caputo–Fabrizio time-fractional derivatives whose orders are distributed in the interval [0, 1). The linear momentum and the Poisson–Boltzmann equations are solved analytically in tandem in the triangular region with the help of the Helmholtz eigenvalue problem and Laplace transforms. The analytical solution developed is exact. The solution technique used is new, leads to exact solutions, is completely different from those available in the literature, and applies to other similar problems. The new expression for the velocity field displays experimentally observed ‘velocity overshoot’ as opposed to existing analytical studies none of which can predict the overshoot phenomenon. We show that when Caputo–Fabrizio time-fractional derivatives approach unity the exact solution for the classical upper convected Maxwell fluid is obtained. The presence of elasticity in the constitutive structure alters the Newtonian velocity profiles drastically. The influence of pertinent parameters on the flow field is explored.
Mouse middle-ear forward and reverse acoustics
Authors: Motallebzadeh Hamid , Puria Sunil
Published: April 2021

The mouse is an important animal model for hearing science. However, our knowledge of the relationship between mouse middle-ear (ME) anatomy and function is limited. The ME not only transmits sound to the cochlea in the forward direction, it also transmits otoacoustic emissions generated in the cochlea to the ear canal (EC) in the reverse direction. Due to experimental limitations, a complete characterization of the mouse ME has not been possible. A fully coupled finite-element model of the mouse EC, ME, and cochlea was developed and calibrated against experimental measurements. Impedances of the EC, ME, and cochlea were calculated, alongside pressure transfer functions for the forward, reverse, and round-trip directions. The effects on sound transmission of anatomical changes such as removing the ME cavity, pars flaccida, and mallear orbicular apophysis were also calculated. Surprisingly, below 10 kHz, the ME cavity, eardrum, and stapes annular ligament were found to significantly affect the cochlear input impedance, which is a result of acoustic coupling through the round window. The orbicular apophysis increases the delay of the transmission line formed by the flexible malleus, incus, and stapes, and improves the forward sound-transmission characteristics in the frequency region of 7–30 kHz.
Modelling and measurement of laser-generated focused ultrasound: Can interventional transducers achieve therapeutic effects?
Authors: Aytac-Kipergil Esra , Desjardins Adrien E. , Treeby Bradley E. , Noimark Sacha , Parkin Ivan P. , Alles Erwin J.
Published: April 2021

Laser-generated focused ultrasound (LGFU) transducers used for ultrasound therapy commonly have large diameters (6–15 mm), but smaller lateral dimensions (<4 mm) are required for interventional applications. To address the question of whether miniaturized LGFU transducers could generate sufficient pressure at the focus to enable therapeutic effects, a modelling and measurement study is performed. Measurements are carried out for both linear and nonlinear propagation for various illumination schemes and compared with the model. The model comprises several innovations. First, the model allows for radially varying acoustic input distributions on the surface of the LGFU transducer, which arise from the excitation light impinging on the curved transducer surfaces. This realistic representation of the source prevents the overestimation of the achievable pressures (shown here to be as high as 1.8 times). Second, an alternative inverse Gaussian illumination paradigm is proposed to achieve higher pressures; a 35% increase is observed in the measurements. Simulations show that LGFU transducers as small as 3.5 mm could generate sufficient peak negative pressures at the focus to exceed the cavitation threshold in water and blood. Transducers of this scale could be integrated with interventional devices, thereby opening new opportunities for therapeutic applications from inside the body.
Hand Movements in Communicative and Noncommunicative Situations in Very Young Infants: A Preliminary Study
Authors: Somogyi Eszter , Salomon Laurent , Fagard Jacqueline
Published: April 2021

As a step toward understanding the developmental relationship between handedness and language lateralization, this longitudinal study investigated how infants (N = 21) move their hands in noncommunicative and communicative situations at 2 weeks and at 3 months of age. The authors looked at whether left-right asymmetry in hand movements and in duration of self-touch appeared across conditions and whether the direction of asymmetry depended on the communicative nature of the situation. The authors found that asymmetries appeared less consistently than suggested in literature and did not only depend on the communicative nature of the situation. Instead, hand activity and self-touch patterns depended on age, the presence of the mother, the degree of novelty of the situation, and the presence of an object. The results partly support previous studies that pointed out an early differentiation of communicative hand movements versus noncommunicative ones in infants. It is in terms of the amount of global hand activity, rather than in those of the laterality of hand movements that this differentiation emerged in this study. At 3 months, infants moved their hands more in the communicative conditions than in the noncommunicative conditions and this difference appeared as a tendency already at 2 weeks of age.
Examining the Role of Risk Compensation in Extreme Sports
Authors: Gardner Megan M. , Grimm Jeff T. , Conner Bradley T.
Published: April 2021

This study explored the relations between sensation seeking, impulsivity, risk compensation, and extreme-sports injury to better understand contributing factors to risk taking in extreme sports and subsequent adverse outcomes. Data included cross-sectional survey responses from 1,107 college students (Mage = 19.47,SD = 2.14). Poisson, logistic, and negative binomial regressions were used to investigate the relations of interest. Results indicate that sensation seeking and impulsivity are significantly associated with both risk compensation and extreme-sports injury. Risk compensation is significantly and positively associated with extreme-sports injury in mountain biking and snowboarding. Risk compensation did not significantly moderate the relation between the personality constructs of interest and extreme-sports injury. These results show that the role of risk compensation in extreme-sports injury is highly sport-specific. These results highlight the importance of considering both personality and risk compensation in prevention and intervention efforts.
Role of the SOS Response in the Generation of Antibiotic Resistance
In Vivo
Authors: Crane John K. , Alvarado Cassandra L. , Sutton Mark D.
Published: April 2021

The SOS response to DNA damage is a conserved stress response in Gram-negative and Gram-positive bacteria. Although this pathway has been studied for years, its relevance is still not familiar to many working in the fields of clinical antibiotic resistance and stewardship.
Pyrogallol and Fluconazole Interact Synergistically
In Vitro
against Candida glabrata through an Efflux-Associated Mechanism
Authors: Yao Dongting , Zhang Guanyi , Chen Weiqin , Chen Jia , Li Zhen , Zheng Xin , Yin Hongmei , Hu Xiaobo
Published: April 2021

Candida glabrata
is currently the first or second most commonly encountered non-
albicans Candida
species worldwide. The potential severity of
Candida
resistance mandates the discovery of novel antifungal agents, including those that can be used in combination therapies.
Mutations in Ehrlichia chaffeensis Genes ECH_0660 and ECH_0665 Cause Transcriptional Changes in Response to Zinc or Iron Limitation
Authors: Torres-Escobar Ascención , Juárez-Rodríguez María D. , Ganta Roman R.
Published: April 2021

Ehrlichia chaffeensis
, a tick-transmitted bacterium, causes human monocytic ehrlichiosis by replicating within phagosomes of monocytes/macrophages. A function disruption mutation within the pathogen’s gene encoding a phage head-to-tail connector protein resulted in the rapid clearance of the pathogen
in vivo
, while aiding in induction of sufficient immunity in a host to protect against wild-type infection challenge.
Quantitative Assessment of Nucleocytoplasmic Large DNA Virus and Host Interactions Predicted by Co-occurrence Analyses
Authors: Meng Lingjie , Endo Hisashi , Blanc-Mathieu Romain , Chaffron Samuel , Hernández-Velázquez Rodrigo , Kaneko Hiroto , Ogata Hiroyuki
Published: April 2021

NCLDVs can infect a wide range of eukaryotes, although their life cycle is less dependent on hosts compared to other viruses. However, our understanding of NCLDV-host systems is highly limited because few of these viruses have been isolated so far.
Central administration of sodium-glucose cotransporter-2 inhibitors increases food intake involving adenosine monophosphate-activated protein kinase phosphorylation in the lateral hypothalamus in healthy rats
Authors: Takeda Kenji , Ono Hiraku , Ishikawa Ko , Ohno Tomohiro , Kumagai Jin , Ochiai Hidetoshi , Matumoto Ai , Yokoh Hidetaka , Maezawa Yoshiro , Yokote Koutaro
Published: April 2021

Introduction

Sodium glucose cotransporter-2 (SGLT2) inhibitors are widely used for diabetes treatment. Although SGLT2 inhibitors have been clinically observed to increase food intake, roles or even the presence of SGLT2 in the central nervous system (CNS) has not been established. We aimed to elucidate potential functions of SGLT2 in the CNS, and the effects of CNS-targeted SGLT2 inhibitors on food intake.

Research design and methods

We administered three kinds of SGLT2 inhibitors, tofogliflozin, dapagliflozin, and empagliflozin, into the lateral ventricle (LV) in rats and evaluated their effects on food intake. We also evaluated the effects of tofogliflozin administration in the third (3V) and fourth ventricle (4V). Intraperitoneal administration of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist known to suppress food intake, was combined with central tofogliflozin to elucidate whether GLP-1 signaling antagonizes the effect of central SGLT2 inhibitors on food intake. To elucidate potential molecular mechanisms mediating changes in feeding, hypothalamic areas associated with food intake regulation were harvested and analyzed after intracerebroventricular administration (ICV) of tofogliflozin.

Results

Bolus ICV injection of tofogliflozin induced a robust increase in food intake starting at 1.5 hours postinjection, and lasting for 5 days. No effect was observed when the same dose of tofogliflozin was administered intraperitoneally. ICV dapagliflozin and empagliflozin significantly enhanced food intake, although the strength of these effects varied among drugs. Food intake was most markedly enhanced when tofogliflozin was infused into the LV. Fewer or no effects were observed with infusion into the 3V or 4V, respectively. Systemic administration of liraglutide suppressed the effect of ICV tofogliflozin on food intake. ICV tofogliflozin increased phosphorylation of AMPK and c-fos expression in the lateral hypothalamus.

Conclusions

SGLT2 inhibitors in the CNS increase food intake. SGLT2 activity in the CNS may regulate food intake through AMPK phosphorylation in the lateral hypothalamic area.
Modest effects of dietary supplements during the COVID-19 pandemic: insights from 445 850 users of the COVID-19 Symptom Study app
Authors: Louca Panayiotis , Murray Benjamin , Klaser Kerstin , Graham Mark S , Mazidi Mohsen , Leeming Emily R , Thompson Ellen , Bowyer Ruth , Drew David A , Nguyen Long H , Merino Jordi , Gomez Maria , Mompeo Olatz , Costeira Ricardo , Sudre Carole H , Gibson Rachel , Steves Claire J , Wolf Jonathan , Franks Paul W , Ourselin Sebastien , Chan Andrew T , Berry Sarah E , Valdes Ana M , Calder Philip C , Spector Tim D , Menni Cristina
Published: April 2021

Objectives

Dietary supplements may ameliorate SARS-CoV-2 infection, although scientific evidence to support such a role is lacking. We investigated whether users of the COVID-19 Symptom Study app who regularly took dietary supplements were less likely to test positive for SARS-CoV-2 infection.

Design

App-based community survey.

Setting

445 850 subscribers of an app that was launched to enable self-reported information related to SARS-CoV-2 infection for use in the general population in the UK (n=372 720), the USA (n=45 757) and Sweden (n=27 373).

Main exposure

Self-reported regular dietary supplement usage (constant use during previous 3 months) in the first waves of the pandemic up to 31 July 2020.

Main outcome measures

SARS-CoV-2 infection confirmed by viral RNA reverse transcriptase PCR test or serology test before 31 July 2020.

Results

In 372 720 UK participants (175 652 supplement users and 197 068 non-users), those taking probiotics, omega-3 fatty acids, multivitamins or vitamin D had a lower risk of SARS-CoV-2 infection by 14% (95% CI (8% to 19%)), 12% (95% CI (8% to 16%)), 13% (95% CI (10% to 16%)) and 9% (95% CI (6% to 12%)), respectively, after adjusting for potential confounders. No effect was observed for those taking vitamin C, zinc or garlic supplements. On stratification by sex, age and body mass index (BMI), the protective associations in individuals taking probiotics, omega-3 fatty acids, multivitamins and vitamin D were observed in females across all ages and BMI groups, but were not seen in men. The same overall pattern of association was observed in both the US and Swedish cohorts.

Conclusion

In women, we observed a modest but significant association between use of probiotics, omega-3 fatty acid, multivitamin or vitamin D supplements and lower risk of testing positive for SARS-CoV-2. We found no clear benefits for men nor any effect of vitamin C, garlic or zinc. Randomised controlled trials are required to confirm these observational findings before any therapeutic recommendations can be made.
Head injury assessment in rugby union: clinical judgement guidelines
Authors: Falvey Éanna , Tucker Ross , Fuller Gordan , Raftery Martin
Published: April 2021

Background/aim

Clinical judgement is a recognised component of a complete off-field concussion assessment. This study identifies guidance criteria for team medical staff when using clinical judgement in their decision-making process during the World Rugby off-field concussion-assessment screen (HIA1).

Methods

Retrospective study of examining doctor clinical judgement in 1149 HIA1 assessments after a meaningful head impact event completed on rugby union players participating in elite-level international and national competitions between September 2015 and June 2018. We assessed (1) an abnormal subtest result as worse performance compared with preseason baseline values; (2) the proportion of cases where clinicians overruled abnormal HIA1 assessment subtest results and (3) made recommendations on how clinical judgement decisions may be made more safely based on the accuracy of clinical judgement decisions assessed against the final concussion diagnosis.

Results

One or more subtests were abnormal compared with baseline values in 857 of 1149 HIA1 assessments. Clinical judgement was used to return players to the game despite abnormal subtest results on 424 out of 857 occasions (49%). In a significant majority of cases 356/424 (84%), clinical judgement decisions were correct, with players later cleared of a concussion. An application of guided clinical judgement potentially decreased false negative assessments by 33% (21/63).

Conclusions

Clinical judgement should be applied in the diagnosis of concussion but done so cautiously. We propose doctors should only use clinical judgement to overrule either one of; or a combination of (1) an abnormal tandem gait and (2) one abnormal cognitive test.
Making a business plan for starting a transitional pain service within the US healthcare system
Authors: Sun Eric C , Mariano Edward R , Narouze Samer , Gabriel Rodney A , Elsharkawy Hesham , Gulur Padma , Merrick Sharon K , Harrison T Kyle , Clark J David
Published: April 2021

Chronic pain imposes a tremendous economic burden of up to US$635 billion per year in terms of direct costs (such as the costs of treatment) and indirect costs (such as lost productivity and time away from work). In addition, the initiation of opioids for pain is associated with a more than doubling of pharmacy and all-cause medical costs. The high costs of chronic pain are particularly relevant for anesthesiologists because surgery represents an inciting event that can lead to chronic pain and long-term opioid use. While the presence of risk factors and an individual patient’s postoperative pain trajectory may predict who is at high risk for chronic pain and opioid use after surgery, to date, there are few interventions proven to reduce these risks. One promising approach is the transitional pain service. Programs like this attempt to bridge the gap between acute and chronic pain management, provide continuity of care for complicated acute pain patients after discharge from the hospital, and offer interventions for patients who are on abnormal trajectories of pain resolution and/or opioid use. Despite awareness of chronic pain after surgery and the ongoing opioid epidemic, there are few examples of successful transitional pain service implementation in the USA. Key issues and concerns include financial incentives and the required investment from the hospital or healthcare system. We present an economic analysis and discussion of important considerations when developing a business plan for a transitional pain service.
Using steady shear rate sweep protocol to determine zero shear viscosity of unaged and aged unmodified bituminous binders
Authors: Mubashirhussain Syed , Chowdary Venkaiah
Published: April 2021

Rutting is one of the most significant distresses occurring in bituminous pavements at higher pavement temperatures. Researchers have been focusing on developing bitumen binder parameters that can be used to predict the rutting resistance of bituminous mixtures, and zero shear viscosity (ZSV) has proven its efficacy as a binder rutting parameter. A stepwise steady shear rate sweep test with two cycles of forward and backward sweeps was conducted at very low shear rates to determine the ZSV of unaged, short-term aged, and long-term aged unmodified bitumen binders. Convergence of the steady-state viscosities was observed at different shear rates in the first forward sweep. The response of the binders was independent of the shear rate, time, and the effect of shear history was negligible. As the shear rates corresponded to the ZSV regime, the ZSV was determined from the first forward sweep. The ZSV correlated well with the three existing rutting parameters.
Cosmological constraints on entropic cosmology with matter creation
Authors: Gohar Hussain , Salzano Vincenzo
Published: April 2021

We investigate entropic force cosmological models with the possibility of matter creation and energy exchange between the bulk and the horizon of a homogeneous and isotropic flat Universe. We consider three different kinds of entropy, Bekenstein’s, the non-extensive Tsallis–Cirto’s, and the quartic entropy, plus some phenomenological functional forms for matter creation rate to model different entropic force models and put the observational constraints on them. We show that while most of them are indistinguishable from a standard $$\Lambda $$
Λ
CDM scenario, the Bekenstein entropic force model with a matter creation rate proportional to the Hubble parameter is statistically highly favored over $$\Lambda $$
Λ
CDM. As a general result, we also find that both the Hawking temperature parameter $$\gamma $$
γ
, which relates the energy exchange between the bulk and the boundary of the Universe, and the matter creation rate $$\Gamma (t)$$

Γ
(
t
)

, must be very small to reproduce observational data.
NEURAL NETWORK-BASED REPAIRING SKULL DEFECTS: AN INITIAL ASSESSMENT OF PERFORMANCE AND FEASIBILITY
Authors: ZHANG QUAN , XU YAWEN , ZHOU JINGYU , PENG BO , ZHANG QIANYU , JIA WEI
Published: April 2021

Accurate 3D reconstruction of the defective part is critically important for repairing defects in the human skull. After investigating the feasibility of 3D convolution neural network (CNN)-based approach, DeepMedic CNN is chosen for repairing defects of the human skull. Training set of 3D CNN model is produced by randomly segmenting the initial 3D model of the skull which come from a whole CT scan of a healthy person. The 3D CNN model was evaluated using a computer-simulated 3D skull model containing the defective part, and in vivo patient. The results showed that based on 160 groups of computer-simulated 3D CT data, the average dice similarity coefficient (DSC), sensitivity (SE) and Hausdorff distance (HD) are 89.31%, 91.81%, and 25.9%, respectively. These quantitative indexes showed that the proposed method is able to do a reliable bone structure predication. For in vivo patient, the obtained model is also able to generate a suitable 3D bone model for the data under consideration. This approach could increase the computational efficiency of the repairing process without the need for segmentation and reconstruction of the skull, and thereby has potential applications to motivating further accurate repairing of defects of skull.
EXPERIMENTAL STUDY OF DOUBLE CABLE-CONDUIT DRIVING DEVICE FOR MRI COMPATIBLE BIOPSY ROBOTS
Authors: JIA XIAOHONG , ZHANG YONGDE , DU HAIYAN , YU YAN
Published: April 2021

Magnetic resonance imaging (MRI) is better than other imaging equipment in detecting tumors, and navigation for robotic breast intervention biopsy. However, material requirements for robots driving devices are demanding incredibly because of the environment. Given this problem, a novel double cable-conduit driving method is put forward in this paper, which can be used in MRI for breast intervention robots. Besides, lebus grooves are adopted to the driving wheels, which enable the system to realize remote-range and large-scale driving on the premise that the precision can be further enhanced. The driving characteristic of the novel cable-conduit is established. Moreover, the cable-conduit experimental data proves the results of theoretical deduction. Finally, the cable-conduit driving device is compensated, the average errors in the [Formula: see text], [Formula: see text], and [Formula: see text] directions of the needle tip entering the tissue are less than 2[Formula: see text]mm. The consequence verifies that it can meet the requirements for breast biopsy robot application under MR environment.
PREDICTION OF HYPERTENSION RISKS WITH FEATURE SELECTION AND XGBOOST
Authors: PENG YAN , XU JING , MA LING , WANG JIE
Published: April 2021

There are about 1 billion hypertensives patients on a global scale. Hypertension has become the main cause of shorter lifespan and disability for humans worldwide. In this essay, we constructed a new model based on hybrid feature selection and the standard XGBoost for hypertension detection and prediction. After having successfully utilized Lasso regression to identify hypertension-related factors, we used the standard XGBoost model for hypertension prediction. The result from the experiments conducted on the data from the BRFSS shows that proposed model can achieve 77.2% accuracy and 84.6% AUC, both about 7% higher than that without the nonoptimized model. Our proposed model can not only be used to predict the risk of hypertension, but also provide customers with suggestions on how to lead a healthy lifestyle.
Discussion of “How Does Culture Impinge Upon Managers’ Demeanor of Earnings Management? Evidence From Cross-Country Analysis”
Authors: Radhakrishnan Suresh , Janakiraman Surya
Published: April 2021

We provide a framework that builds upon the findings of Chaney, Lodh and Nandy (2021) for future research to examine the mechanism through which national culture is related to earnings management. In particular, the framework can be used to examine how specific contexts, reference points, corporate culture and economic institutions affect the relation between national culture and earnings management.
Application of multivariate geostatistical simulation and fractal analysis for detection of rare-earth element geochemical anomalies in the Esfordi phosphate mine, Central Iran
Authors: Shamseddin Meigooni Mojtaba , Lotfi Mohammad , Afzal Peyman , Nezafati Nima , Razi Maryam Kargar
Published: April 2021

The present study was conducted to determine different geochemical anomalies of rare-earth elements (REEs) using a combined approach of stepwise factor analysis (SFA), sequential Gaussian simulation (SGS), and concentration–area (C-A) fractal modeling based on surface lithogeochemical samples obtained from the Esfordi phosphate mine (Central Iran). The Esfordi mine is one of the important mines in the Bafq metallogenic zone due to average and maximum grades of 0.5 and 1.7%, respectively for REEs. With SFA operating in two steps, the REEs were placed in the first factor of the second stage (F1-2). Then, SGS and C-A fractal modeling were performed on F1-2 factor scores for classification of anomalies. A log-ratio matrix was used to evaluate the correlation of these results with anomalous lithogeochemical samples, as well as to determine the relationship of anomalies with rock types and mineralized units and, finally, to validate the results of the SGS–fractal modeling. The results confirmed an appropriate correlation between F1-2 anomalies and high concentration in further rock samples. The main anomalies were found to have good correlation with an apatite–iron unit and in general with other apatite-bearing units based on overall accuracy values. The apatite-bearing units with high values of REEs were located in the northern and central parts of the mine. The results of the SFA, SGS and C-A fractal modeling show that this hybrid approach can be useful in determining anomalies with high accuracy.
Supporting Mixed-domain Mixed-precision Matrix Multiplication within the BLIS Framework
Authors: Van Zee Field G. , Parikh Devangi N. , Geijn Robert A. Van De
Published: April 2021

We approach the problem of implementing mixed-datatype support within the general matrix multiplication (
gemm
) operation of the BLAS-like Library Instantiation Software framework, whereby each matrix operand
A
,
B
, and
C
may be stored as single- or double-precision real or complex values. Another factor of complexity, whereby the matrix product and accumulation are allowed to take place in a precision different from the storage precisions of either
A
or
B
, is also discussed. We first break the problem into orthogonal dimensions, considering the mixing of domains separately from mixing precisions. Support for all combinations of matrix operands stored in either the real or complex domain is mapped out by enumerating the cases and describing an implementation approach for each. Supporting all combinations of storage and computation precisions is handled by typecasting the matrices at key stages of the computation—during packing and/or accumulation, as needed. Several optional optimizations are also documented. Performance results gathered on a 56-core Marvell ThunderX2 and a 52-core Intel Xeon Platinum demonstrate that high performance is mostly preserved, with modest slowdowns incurred from unavoidable typecast instructions. The mixed-datatype implementation confirms that combinatorial intractability is avoided, with the framework relying on only two assembly microkernels to implement 128 datatype combinations.
Recycling Krylov Subspaces and Truncating Deflation Subspaces for Solving Sequence of Linear Systems
Authors: Daas Hussam Al , Grigori Laura , Hénon Pascal , Ricoux Philippe
Published: April 2021

This article presents deflation strategies related to recycling Krylov subspace methods for solving one or a sequence of linear systems of equations. Besides well-known strategies of deflation, Ritz-, and harmonic Ritz-based deflation, we introduce an Singular Value Decomposition based deflation technique. We consider the recycling in two contexts: recycling the Krylov subspace between the restart cycles and recycling a deflation subspace when the matrix changes in a sequence of linear systems. Numerical experiments on real-life reservoir simulation demonstrate the impact of our proposed strategy.
Algorithm 1015
Authors: Guthe Stefan , Thuerck Daniel
Published: April 2021

We present a new algorithm for solving the dense linear (sum) assignment problem and an efficient, parallel implementation that is based on the successive shortest path algorithm. More specifically, we introduce the well-known epsilon scaling approach used in the Auction algorithm to approximate the dual variables of the successive shortest path algorithm prior to solving the assignment problem to limit the complexity of the path search. This improves the runtime by several orders of magnitude for hard-to-solve real-world problems, making the runtime virtually independent of how hard the assignment is to find. In addition, our approach allows for using accelerators and/or external compute resources to calculate individual rows of the cost matrix. This enables us to solve problems that are larger than what has been reported in the past, including the ability to efficiently solve problems whose cost matrix exceeds the available systems memory. To our knowledge, this is the first implementation that is able to solve problems with more than one trillion arcs in less than 100 hours on a single machine.
2-Approximating Feedback Vertex Set in Tournaments
Authors: Lokshtanov Daniel , Misra Pranabendu , Mukherjee Joydeep , Panolan Fahad , Philip Geevarghese , Saurabh Saket
Published: April 2021

A
tournament
is a directed graph
T
such that every pair of vertices is connected by an arc. A
feedback vertex set
is a set
S
of vertices in
T
such that
T
−
S
is acyclic. We consider the Feedback Vertex Set problem in tournaments. Here, the input is a tournament
T
and a weight function
w
:
V
(
T
) → N, and the task is to find a feedback vertex set
S
in
T
minimizing
w
(
S
) = ∑

v∈S

w
(
v
). Rounding optimal solutions to the natural LP-relaxation of this problem yields a simple 3-approximation algorithm. This has been improved to 2.5 by Cai et al. [SICOMP 2000], and subsequently to 7/3 by Mnich et al. [ESA 2016]. In this article, we give the first polynomial time factor 2-approximation algorithm for this problem. Assuming the Unique Games Conjecture, this is the best possible approximation ratio achievable in polynomial time.
The Complexity of Approximating the Matching Polynomial in the Complex Plane
Authors: Bezáková Ivona , Galanis Andreas , Goldberg Leslie Ann , Štefankovič Daniel
Published: April 2021

We study the problem of approximating the value of the matching polynomial on graphs with edge parameter γ, where γ takes arbitrary values in the complex plane.

When γ is a positive real, Jerrum and Sinclair showed that the problem admits an FPRAS on general graphs. For general complex values of γ, Patel and Regts, building on methods developed by Barvinok, showed that the problem admits an FPTAS on graphs of maximum degree Δ as long as γ is not a negative real number less than or equal to −1/(4(Δ −1)). Our first main result completes the picture for the approximability of the matching polynomial on bounded degree graphs. We show that for all Δ ≥ 3 and all real γ less than −1/(4(Δ −1)), the problem of approximating the value of the matching polynomial on graphs of maximum degree Δ with edge parameter γ is #P-hard.

We then explore whether the maximum degree parameter can be replaced by the connective constant. Sinclair et al. showed that for positive real γ, it is possible to approximate the value of the matching polynomial using a correlation decay algorithm on graphs with bounded connective constant (and potentially unbounded maximum degree). We first show that this result does not extend in general in the complex plane; in particular, the problem is #P-hard on graphs with bounded connective constant for a dense set of γ values on the negative real axis. Nevertheless, we show that the result does extend for any complex value γ that does not lie on the negative real axis. Our analysis accounts for complex values of γ using geodesic distances in the complex plane in the metric defined by an appropriate density function.
Fault Diagnosis of Rolling Bearing Using Improved Wavelet Threshold Denoising and Fast Spectral Correlation Analysis
Authors: Tian Shaoning , Zhen Dong , Guo Junchao , Li Haiyang , Zhang Hao , Gu Fengshou
Published: April 2021

Rolling bearings are important parts of mechanical equipment. However, the early failures of the bearing are usually masked by heavy noise. This brings about difficulties to the extraction of its fault features. Therefore, there is a need to develop a reliable method for early fault detection of the bearing. Considering this issue, a novel fault diagnosis method using the improved wavelet threshold denoising and fast spectral correlation (Fast‐SC) is proposed. First, to solve the discontinuity of the hard threshold function and avoid the constant deviation triggered by the soft threshold function, a piecewise continuous threshold function is proposed by using a new threshold selection rule to denoise the original signal. In the new threshold function, the adjuster α is introduced to improve the traditional wavelet denoising algorithm, so as to enhance the signal‐to‐noise ratio (SNR) of the original signal more effectively. Then, the denoised signal is analysed by Fast‐SC to identify the rolling bearing fault features. Finally, simulation analysis and experimental data demonstrate that the proposed approach is effective for rolling bearing fault detection compared with Fast‐SC and the combined method based on traditional wavelet threshold and Fast‐SC.
Local Cultural IP Development and Cultural Creative Design Based on Big Data and Internet of Things
Authors: Bi Wei , Wang Guangming
Published: April 2021

Relying on the development of cultural tourism resources and the development of cultural tourism industry to achieve regional industrial revitalization is an important way of implementing postdisaster reconstruction in areas suffering from major natural disasters. To this end, this article proposes a local cultural IP development and cultural creative design method based on big data and the Internet of Things to explore new ideas for postdisaster reconstruction in such areas. First, we collect traditional and modern cultural element data and carry out data cleaning and processing through the Internet of Things. Second, we use data mining to perform multilayer collaborative processing on regional cultural data based on ontology modeling and tensor decomposition. Based on our approach, local cultural categories can be effectively screened and filtered out. Finally, we establish a cultural IP development model based on the Internet of Things and verify the validity and applicability of the model through system testing and simulation analysis.
Deep CNN and Deep GAN in Computational Visual Perception‐Driven Image Analysis
Authors: Nandhini Abirami R. , Durai Raj Vincent P. M. , Srinivasan Kathiravan , Tariq Usman , Chang Chuan-Yu
Published: April 2021

Computational visual perception, also known as computer vision, is a field of artificial intelligence that enables computers to process digital images and videos in a similar way as biological vision does. It involves methods to be developed to replicate the capabilities of biological vision. The computer vision’s goal is to surpass the capabilities of biological vision in extracting useful information from visual data. The massive data generated today is one of the driving factors for the tremendous growth of computer vision. This survey incorporates an overview of existing applications of deep learning in computational visual perception. The survey explores various deep learning techniques adapted to solve computer vision problems using deep convolutional neural networks and deep generative adversarial networks. The pitfalls of deep learning and their solutions are briefly discussed. The solutions discussed were dropout and augmentation. The results show that there is a significant improvement in the accuracy using dropout and data augmentation. Deep convolutional neural networks’ applications, namely, image classification, localization and detection, document analysis, and speech recognition, are discussed in detail. In‐depth analysis of deep generative adversarial network applications, namely, image‐to‐image translation, image denoising, face aging, and facial attribute editing, is done. The deep generative adversarial network is unsupervised learning, but adding a certain number of labels in practical applications can improve its generating ability. However, it is challenging to acquire many data labels, but a small number of data labels can be acquired. Therefore, combining semisupervised learning and generative adversarial networks is one of the future directions. This article surveys the recent developments in this direction and provides a critical review of the related significant aspects, investigates the current opportunities and future challenges in all the emerging domains, and discusses the current opportunities in many emerging fields such as handwriting recognition, semantic mapping, webcam‐based eye trackers, lumen center detection, query‐by‐string word, intermittently closed and open lakes and lagoons, and landslides.
Impact of MMP2 rs243865 and MMP3 rs3025058 Polymorphisms on Clinical Findings in Alzheimer’s Disease Patients
Authors: Durmanova Vladimira , Javor Juraj , Parnicka Zuzana , Minarik Gabriel , Ocenasova Agata , Vaseckova Barbora , Reznakova Veronika , Kralova Maria , Hromadka Tomas , Shawkatova Ivana
Published: April 2021

Alzheimer’s disease (AD) is a chronic neurodegenerative disease of the central nervous system with higher prevalence in elderly people. Despite numerous research studies, the etiopathogenesis of AD remains unclear. Matrix metalloproteinases (MMPs) are endopeptidases involved in the cleavage of extracellular matrix proteins and basement membrane compounds. In the brain, the pathological role of MMPs includes the disruption of the blood-brain barrier leading to the induction of neuroinflammation. Among various MMPs, MMP-2 and MMP-3 belong to candidate molecules related to AD pathology. In our study, we aimed to evaluate the association of MMP2 rs243865 and MMP3 rs3025058 polymorphisms with AD susceptibility and their influence on age at onset and MoCA score in patients from Slovakia. Both MMP gene promoter polymorphisms were genotyped in 171 AD patients and 308 controls by the PCR-RFLP method. No statistically significant differences in the distribution of MMP2 rs243865 (-1306 C>T) and MMP3 rs3025058 (-1171 5A>6A) alleles/genotypes were found between AD patients and the control group. However, correlation with clinical findings revealed later age at disease onset in MMP2 rs243865 CC carriers in the dominant model as compared to T allele carriers (CC vs. CT+TT:

78.44
±
6.28

vs.

76.36
±
6.39

,

p
=
0.036

). The results of MMP3 rs3025058 analysis revealed that 5A/6A carriers in the overdominant model tended to have earlier age at disease onset as compared to other MMP3 genotype carriers (5A/6A vs. 5A/5A+6A/6A:

76.61
±
5.88

vs.

78.57
±
6.79

,

p
=
0.045

). In conclusion, our results suggest that MMP2 rs243865 and MMP3 rs3025058 promoter polymorphisms may have influence on age at onset in AD patients.
Analysis of Coordinated Operation of the Clean Energy System Based on the Multiobjective Optimization Model
Authors: Wang Xunyang , Ma Zhicheng , Liang Chen , He Shien , Wang Yongqiang
Published: April 2021

With the increase in the proportion of clean energy connected to the grid, the effective coordination of the operation of various energy power has become a new challenge facing the current power system scheduling. The coordinated operation of the clean energy power generation system can alleviate the contradiction between power generation and output power fluctuations and overcome the bottleneck of new energy development. Considering the natural characteristics of clean energy, this paper aims to make full use of clean energy, reduce system operating costs, increase system power generation, and reduce output fluctuations; we establish a multiobjective optimization model for coordinated scheduling of clean energy power systems. The model seeks to maximize power generation and minimize output fluctuations, power purchase costs, and maintenance costs under the constraints of the grid structure. In this paper, the

GA
_
PSO

joint algorithm has an accelerated effect on the target optimization calculation, and then the superiority of the

GA
_
PSO

algorithm is verified by the

I
E
E
E
14

standard system. The standard IEEE39 node test system is used to verify the rationality and feasibility of the model built and provides a reference strategy for the coordinated operation mechanism of the clean energy system. According to the model, in the example in this paper, the maximum value of photovoltaic power prediction is 1290 MW, and the minimum value is 210 MW; the maximum value of wind power prediction is 780 MW, and the minimum value is 28 MW; the minimum cost of power purchase and maintenance is 56,950.395; the maximum generating capacity is 5.045 GW; the minimum output fluctuation is 0.120 GW.
Design and Experimental Analysis of Multiband Compound Reconfigurable 5G Antenna for Sub‐6 GHz Wireless Applications
Authors: Ahmad Ikhlas , Dildar Haris , Khan Wasi Ur Rehman , Shah Syed Amir Ali , Ullah Shakir , Ullah Sadiq , Umar Syed Muhammad , Albreem Mahmoud A. , Alsharif Mohammed H. , Vasudevan Kasturi
Published: April 2021

In this paper, a printed low‐profile antenna with frequency and pattern reconfigurable functionality is designed in three modes. Each mode operates at different frequency bands and has several options available for pattern reconfiguration in these bands. The proposed antenna consists of eight pin‐diode switches (S1 to S8). The switches S1 and S2, installed in the radiating patch, are used for frequency reconfigurability to control the operating bands of the antenna. The rest of the six switches (S3, S4, S5, S6, S7, and S8), loaded in the stubs on the rear side of the antenna, are used for pattern reconfiguration to control the main lobe beam steering. When all switches are off, the proposed antenna operates in a wideband mode, covering the 3.82‐9.32 GHz frequency range. When S1 is on, the antenna resonates in the 3.5 GHz (3.09‐4.17 GHz) band. When both S1 and S2 are on, the resonant band of the antenna is shifted to 2.5 GHz band (2.40‐2.81 GHz). A very good impedance matching with a return loss of less than ‐10 dB is attained in these bands. The beam steering is done at each operating frequency by controlling the on and off states of the six pin‐diode switches (S3, S4, S5, S6, S7, and S8). Depending on the state of the switches, the antenna can direct the beam in seven distinct directions at 4.2 GHz, 4.5 GHz, and 5 GHz. The main beam of the radiation pattern is steered in five different directions at 5.5 GHz, 3.5 GHz, and 2.6 GHz operating bands for the given state of the mentioned switches. The proposed antenna supports several sub‐6 GHz 5G bands (2.6 GHz, 3.5 GHz, 4.2 GHz, 4.5 GHz, and 5 GHz) and can be used in handheld 5G devices.
Hydroxychloroquine Potentiates Apoptosis Induced by PPARα Antagonist in 786-O Clear Cell Renal Cell Carcinoma Cells Associated with Inhibiting Autophagy
Authors: Mao Ruizhe , Shi Jian , Ma Xuyi , Xu Haiyan
Published: April 2021

Clear cell renal cell carcinoma (ccRCC) is the major pathological pattern of renal cell carcinoma. The ccRCC cells exhibit a certain degree of inherent drug resistance due to some genetic mutations. In recent years, peroxisome proliferator-activated receptor-α (PPARα) antagonists have been reported as a targeted therapeutic drug capable of inducing apoptosis and cell cycle arrest in the ccRCC cell line. Autophagy, which can be induced by stress in eukaryotic cells, plays a complex role in the proliferation, survival, and death of tumor cells. In our study, we found that the expression of PPARα was low in highly differentiated ccRCC tissues and 786-O cell line but high in poorly differentiated ccRCC tissues. The level of PPARα expression in ccRCC tissues is correlated to the grade of differentiation, but not to the sex or age of ccRCC patients. The findings also revealed that the PPARα antagonist GW6471 can lower cell viability and induce autophagy in the 786-O ccRCC cell line. This autophagy can be inhibited by hydroxychloroquine. When treated with a combination of hydroxychloroquine and GW6471, the viability of the 786-O cells was decreased further when compared to the treatment with GW6471 or hydroxychloroquine alone, and apoptosis was promoted. Meanwhile, when human kidney 2 cells were cotreated with hydroxychloroquine and GW6471, cell viability was only slightly influenced. Hence, our finding indicates that the combination of GW6471 and hydroxychloroquine may constitute a novel and potentially effective treatment for ccRCC. Furthermore, this approach is likely to be safe owing to its minimal effects on normal renal tissues.
Antiprotozoal Drug Handling and Management Practices in Asella District, Central Oromia, Ethiopia
Authors: Ababu Ashenafi , Endashaw Dereje , Fesseha Haben , Mathewos Mesfin
Published: April 2021

Background and Methods. Protozoal infections such as dourine caused by trypanosomes are found to be a threat to the life and productivity of the equine population. Inappropriate drug use is a problem of the whole world; however, the degree of the problem is higher in developing countries like Ethiopia. Data on handling and management practices of antiprotozoal drugs are not in place; thus, we estimate the handling and management practice via a simple cross-sectional study design in randomly selected veterinary clinics and private pharmacies in and around Asella, Oromia, central Ethiopia. Results. The preliminary survey comprising 70 animal health professionals and animal owners was undertaken through observation, interview using a structured questionnaire, and discussion with key informants to evaluate their handling and management practices of antiprotozoal drugs. According to the finding of this preliminary survey, there was inadequate antiprotozoal drug distribution and only few drugs, namely, diminazene diaceturate, amprolium, and sulfa drugs, were available with different trade names being imported from different manufacturing countries. Among the current available antiprotozoal drugs circulating in the area, those manufactured and imported from China were highly distributed in the majority of veterinary drug shops. The assessment showed that there was a gap in achieving the required knowledge and practice of proper handling and management issues in the professionals and awareness problems in the community. The study indicated that there were inappropriate transportation and storage practices. Moreover, selling drugs without prescription, ignoring farmers without properly informing the drug withdrawal period, and administration of drugs by nonprofessionals were the other most critical and unethical practices in the area. It is emphasized that this inappropriate handling and management practice, scarcity of antiprotozoal drugs, easy accessibility, and distribution by nonprofessionals could potentially affect the quality, safety, and effectiveness of antiprotozoal drugs which may lead to drug resistance development. Conclusion. Hence, continuous awareness creation in the community, capacity building, training, and upgrading programs to the professionals, as well as strict enforcement of drug control and administration regulation of the country, are essential in the overall effort of improving animal health and productivity through the control of protozoan diseases in and around Asella.