bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of water pollution and source identification in Merbok River Kedah, Northwest Malaysia
Authors: Haidr Ateshan Msahir , Rosmilah Misnan , Som Cit Sinang , Isa Koki Baba
Published: November 2020

This study investigates the temporal water quality variations and pollution sources identification in Merbok River using principal component analysis. The variables analyzed include As, Cd, Pb, Fe, Cr, Mn, Zn, Ni, Ca, Mg, Na, K, NH4, F, Cl, Br, NO2, NO3, SO4, PO4, pH, BOD, DO, COD, turbidity, and salinity. These variables were analyzed using inductively coupled plasma mass spectrometry, ion chromatography, and YSI multiprobe. Principal component analysis (PCA) was utilized to evaluate the variations of the most significant water quality parameters and identify the probable source of the pollutants. From the results of PCA, 86% of the total variations were observed in the water quality data with strong dominance of toxic heavy metals (As, Pb, and Cr), parameters associated with industrial discharge, domestic inputs, overland runoff (NH4, pH, BOD, DO, COD), agrochemicals (NO2, NO3, SO4, PO4), and weathering of basement rocks (Ca, Mg, Cl, F, K, and Na). Most of these parameters were present in concentrations exceeded the reference standards limits used in this study, indicating pollution of the river water. Together with the presence of microbial contamination, the results suggest potential human health risk due to water uses, fish and shellfish consumption. Moreover, the results revealed that anthropogenic activities and weathering were the main sources of pollutants in Merbok River.
Modification of pseudobrookite Fe1.7Mn0.3-xNixTiO5: Influence of Ni-substitution on the magnetic properties
Authors: Sunandar Mashadi , Sarwanto Yosef , Adi Wisnu Ari , Yunasfi Yunasfi
Published: November 2020

In this study, the synthesis of pseudobrookite Fe1.7Mn0.3-xNixTiO5 with variations in composition (x = 0.01, 0.05, 0.1, and 0.15) using a mechanical milling technique has been performed. High purity powder of α-Fe2O3, TiO2, MnCO3, and NiO were prepared as raw materials. The mixture was milled for 5 hours using high energy milling equipment, and sintered at 1000 °C for 5 hours. The refinement result of X-ray diffraction profile shows that the all of pseudobrookite Fe1.7Mn0.3-xNixTiO5 samples have a single phase with particle size of less than 1 μm. The VSM result shows all the samples were ferromagnetic behavior. We concluded that the substitution Ni into Mn on the pseudobrookite Fe1.7Mn0.3-xNixTiO5 can change the magnetic properties of the material from paramagnetic to ferromagnetic through a mechanism of double exchange interaction.
Mortality prediction for acute decompensated heart failure patient using fuzzy neural network
Authors: Abu Yazid Mohamad Haider , Talib Mohamad Shukor , Satria Muhammad Haikal , Harun Habibollah , Abd Ghazi Azmee
Published: November 2020

It has been reported that patients admitted with acute decompensated heart failure (ADHF) face high risk of mortality where 30-day mortality rates are reaching 10%. Identifying patient with high and low risk of mortality could improve clinical outcomes and hospital resources allocation. This paper proposed the use of fuzzy neural network to predict mortality for the patient admitted with ADHF. Results show that fuzzy neural network can predict mortality for ADHF patient with good prediction accuracy with overall accuracy of 88.8% for partition 50 and 90.40% for partition 80.
What is the probability that two elements of a finite ring have product zero?
Authors: Khasraw Sanhan Muhammad Salih
Published: November 2020

In this paper, the probability that two elements of a finite ring have product zero is considered. The bounds of this probability are found for an arbitrary finite commutative ring with identity 1. An explicit formula for this probability in the case of, the ring of integers modulo, is obtained.
Enzyme activity and stability of lactase immobilized on two different supports: Calcium alginate and magnetic chitosan
Authors: Mohd Zawawi Farah Syafiqah , Karim Latiffah , Omar Siti Radhiah , Ali Asma’
Published: November 2020

Lactase is a very important enzyme to cure lactose intolerance problem. However, it is naturally existing in soluble form and cannot be reused. The current study was performed to compare the productivity and stability of lactase immobilized on calcium alginate and magnetic chitosan. The reusability of immobilized enzyme was measured for 28 days. Thermal stability was measured at 27, 37, 50 and 70 ºC. Lactase immobilized on calcium alginate showed a better stability after 21 days where it retained up to 62% of enzyme activity. However, lactase on magnetic chitosan expresses a better thermal stability as it produced 6% more sugar than lactase on calcium alginate at the optimum temperature 50 ºC. Lactase immobilized on calcium alginate and magnetic chitosan showed significantly different enzymatic activity, stability, and reusability.
Characterization of nio-bczy as composite anode prepared by a one-step sol-gel method
Authors: Osman Nafisah , Mohd Senari Shazana , Md Jani Abdul Mutalib
Published: November 2020

A high polarization resistance (Rp) at intermediate temperature (500–800°C) operation has become one of the major challenges in the development of proton-conducting fuel cells (PCFCs). Rp is the resistance of the cell that contributes by the electrodes parts which are anode and cathode as well as their interfacial components. The present study focused on the NiO-Ba(Ce0.6Zr0.4)0.9Y0.1O3-δ (NiO-BCZY) composite anode and its interfacial parts where the oxidation process takes place. The NiO-BCZY with a ratio of 50:50 was prepared by a sol-gel method and characterized by X-Ray Diffractometer (XRD), Field Emission Scanning Electron Microscopy/Energy Dispersive X-ray (FESEM/EDX), and Electrochemical Impedance Spectroscopy (EIS). At calcination temperature of 1100°C, NiO and BCZY oxides can preserve their phases to form composite anode as proven by XRD analysis. Morphology of the composite anode as observed by FESEM was spherical with particle size in the range of 30-70 nm. XRD analysis showed the formation of Ni-BCZY after undergoing reduction process under wet H2:N2 (10%:90%). As confirmed by the EIS data, the increased conductivity of the composite anode in wet H2:N2 (10%:90%) indicates that the NiO in the composite anode was reduced to Ni metal. The fabricated NiO-BCZY composite anode has shown a good potential to be a promising anode in PCFC application.
Effects of graphene polymer nano composite coating on corrosion resistance of Astm A106 carbon steel pipe
Authors: Andsaler Adiba Rhaodah , Philip Wilver , Sudin Izman , Mohd Yusop Mohd Zamri
Published: November 2020

Wide application prospects of graphene in the corrosion protection coatings field are owing to its excellent mechanical properties, outstanding chemical stability, corrosion resistance, and high corrosion resistance. Anti-corrosion composite was prepared using multilayer graphene powder as a filler and epoxy resin in this work to investigate the effect of graphene compositions in the zinc-rich epoxy (ZRE) as the modified anti-corrosion coating for carbon steel pipe. Using SEM for morphology along with the electrochemical performance was associated with changed content composite coating of graphene and pure epoxy resin coating. The measurement for open-circuit potential (OCP), the potentiostat polarization curve (Tafel Plot), and the electrochemical impedance spectroscopy (EIS) of the coating were conducted in order to investigate the influence of additional of graphene on the basic properties and corrosion resistance. From the experimental results, the increasing content of graphene led by the increasing value of OCP as the test system was stable, also the coating of high content graphene sustained a moderately high OCP ability with the increase of immersion time. From the results in the industrial environment, 0.1wt% Graphene + 99.9wt% ZRE in a 240μm coating layer would be sufficient as the corrosion rate is 0.0087204mmpy and three times lower compare to 100wt% ZRE. In a nutshell, the addition of graphene improves the impenetrability of the composite coating.
Physico-mechanical and morphological properties of rice husk-coconut husk fiber reinforced epoxy composites
Authors: Chang Hui Josephine Lai , Azman Fatin Fakhira , Baini Rubiyah
Published: November 2020

In the recent years, many researches focus on “waste to wealth” concept, where agro-waste is converted into various valuable products especially on natural fiber polymeric composites. Selected fibers for this research were rice husk (RH) and coconut husk (CH). This research focused on the property enhancement of RH-CH fiber reinforced epoxy composites and comparison RH reinforced epoxy composites, CH reinforced epoxy composites, and RH-CH reinforced epoxy composites. RH-CH reinforced epoxy composites were well-fabricated by mixing epoxy resin and different ratios of two types natural fibers via compression molding and stir casting methods. All the fabricated RH-CH reinforced epoxy composites were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Vickers Hardness Test (VHT), and tensile test (TT). FTIR results showed that 10wt% RH-CH reinforced epoxy composites created the strongest covalent bonding between cellulose inside RH-CH fiber and epoxide group compared to RH reinforced epoxy composites and CH reinforced epoxy composites. The combination of RH and CH fiber with the introduction of epoxy resin reduced the hydroxyl groups compared to either RH or CH fiber composites, respectively. This proved that mixture of RH and CH with epoxy matrix improved the properties of pure RH and CH and thus, better composites were fabricated. SEM images of 10wt% RH-CH reinforced epoxy composites showed better dispersion of RH-CH fiber within polymer matrix compared to RH reinforced epoxy composites and CH reinforced epoxy composites under the magnification of 2000. Both RH reinforced epoxy composites and CH reinforced epoxy composites showed porosity within the matrix. VHT showed that 10wt% RH-CH reinforced epoxy composites showed the smallest indentation value compared to RH reinforced epoxy composites and CH reinforced epoxy composites due to the highest interfacial adhesion between matrix and filler, which was proven by the SEM images. Tensile test of 10wt% RH-CH reinforced epoxy composites showed the highest tensile modulus with value of 2.6MPa. RH-CH reinforced epoxy composites showed higher tensile strength and modulus compared to RH and CH reinforced epoxy composites. Overall, it could be concluded that 10wt% RH-CH reinforced epoxy composites performed the best in terms of physical, mechanical, and morphological perspective than RH reinforced epoxy composites and CH reinforced epoxy composites. This proved that RH and CH could be well-introduced as reinforcing filler in epoxy matrix to fabricate better composites for structural application.
Experiences of patients with lysosomal storage disorders treated with enzyme replacement therapy: a qualitative systematic review protocol
Authors: Koto Yuta , Ueki Shingo , Yamakawa Miyae , Sakai Norio
Published: November 2020

Objective:

The objective of the review is to investigate the experiences of patients with lysosomal storage disorders treated with enzyme replacement therapy and the experiences of their families.

Introduction:

Lysosomal storage disorders are rare diseases caused by mutations in genes encoding proteins required for lysosomal function. The onset of lysosomal storage disorders vary from infancy to adulthood, depending on the specific disease and disease type. Enzyme replacement therapy is the standard treatment for some lysosomal storage disorders. The adherence to the treatment by patients and their families is affected not only by the symptoms but also by the scheduling of hospital visits. No qualitative systematic review on this topic has examined the experiences of patients and their families.

Inclusion criteria:

Qualitative studies dealing with the experiences of patients with lysosomal storage disorders receiving enzyme replacement therapy and their families will be included. These may include experiences related to satisfaction or dissatisfaction with being diagnosed, difficulties and expectations continuing treatment, the advantages or disadvantages related to school and work life, and the psychological burden and supports on families. This review will consider studies in all settings because relevant experiences of patients and their families may occur outside medical institutions.

Methods:

MEDLINE, CINAHL Plus, APA PsycINFO, Scopus, and Igaku Chuo Zasshi databases will be examined from 1991 to the present. Studies published in any language will be included. The study selection, critical appraisal, data extraction, and data synthesis will be performed in accordance with the guidelines for systematic reviews of qualitative evidence in the JBI Manual for Evidence Synthesis.

Systematic review registration number:

PROSPERO CRD42019147751
Association between developmental coordination disorder or low motor competence, and risk of impaired bone health across the lifespan: protocol for a systematic review and meta-analysis
Authors: Tan Jocelyn , Hart Nicolas H. , Rantalainen Timo , Chivers Paola
Published: November 2020

Objective:

This systematic review will assess the association between developmental coordination disorder or low motor competence and impairments in bone health across the lifespan.

Introduction:

Individuals with developmental coordination disorder tend to have a pattern of physical activity associated with bone health impairments. Preliminary studies have found impairments in bone health measures, including fractures, throughout the lifespan with potential public health ramifications. As studies in this area are of small samples across wide age ranges, no comprehensive picture of bone health in this group has been formed, hindering action. A systematic review is needed to determine the potential risk of bone impairment in this population.

Inclusion criteria:

Studies that assess the relationship between developmental coordination disorder/low motor competence and bone health, regardless of measures used, will be included in the review. There will be no exclusions based on region, study design, or participant demographic characteristics.

Methods:

Published studies and gray literature will be searched, with no limits on publication date or language. Assessment of studies for inclusion, as well as data extraction, will be performed by two reviewers, with data cross checked for accuracy. Studies will be appraised using the appropriate JBI tool for the study design. Data to be extracted include unadjusted results and effect sizes for bone health measures. A narrative synthesis will be performed and if there is a sufficient number of studies, a meta-analysis using the same outcome measures will be performed on odds ratios of abnormal bone phenotype and fracture in this population.

Systematic review registration number:

PROSPERO CRD42020167301
Characteristics and predictors of suicidality in young people with clinical depression: a systematic review protocol
Authors: Moller Carl I. , Davey Christopher G. , Badcock Paul B. , Cotton Sue M.
Published: November 2020

Objective:

The objective of this review is to examine clinical, psychosocial, and biological factors associated with suicidality in young people diagnosed with depression. This review will describe risk and protective factors, focusing on modifiable attributes, in order to inform suicide prevention and early intervention strategies.

Introduction:

Suicide is the world's second-leading cause of death among young people. Depression is closely associated with suicide; however, it lacks specificity as a predictor of suicidal behavior. There is a clear need to improve our understanding of both risk and protective factors associated with the full spectrum of suicidality in young people, across a range of depressive disorders.

Inclusion criteria:

Studies that include young people 15 to 25 years of age with a diagnosis of depression made in accordance with a diagnostic classification standard will be considered. Diagnosis must be made using a structured clinical interview or be received through standard clinical practice. Analytical cross-sectional studies, prospective and retrospective cohort studies, and case-control studies will be included. Studies must include an assessment of suicidality made using standardized or non-standardized tools. A broad range of inpatient and outpatient settings will be considered.

Methods:

MEDLINE, Embase, and PsycINFO will be searched for studies published in English, with no date limitation. Two independent reviewers will conduct study screening, assess methodological quality, and extract data using standardized tools. If there is sufficient homogeneity across studies, meta-analyses using a random-effects model will be conducted. If quantitative meta-analysis is not possible, a narrative synthesis will be undertaken.

Systematic review registration number:

PROSPERO CRD42020151612.
Understanding the experience of diagnostic overshadowing associated with severe mental illness from the consumer and health professional perspective: a qualitative systematic review protocol
Authors: Molloy Renee , Munro Ian , Pope Nicole
Published: November 2020

Objective:

The objective of this review is to identify, appraise, and synthesize available qualitative evidence related to diagnostic overshadowing in mental health consumers who present with clinical manifestations of physical illness.

Introduction:

A lived experience of mental illness is associated with compromised physical health and decreased life expectancy. Mental health consumers face greater barriers to accessing treatment for physical illnesses and are less likely to receive appropriate physical care than those without mental illness. Physical illnesses may go underdiagnosed and undertreated in mental health consumers because clinicians tend to focus on the mental illness to the exclusion of other health problems, a phenomenon called diagnostic overshadowing. This systematic review will combine the experiences of mental health consumers and health care professionals to gain deeper understanding of diagnostic overshadowing.

Inclusion criteria:

This review will consider qualitative studies that include the experiences of diagnostic overshadowing in mental health consumers and/or the health care professionals who treat them. Studies conducted in any health care facility or service offering care for physical illnesses will be considered.

Methods:

MEDLINE, CINAHL, PsycINFO, and Scopus will be searched along with sources of gray literature. Studies in English published from 2004 onward will be considered. Retrieval of full-text studies, assessment of methodological quality, and data extraction will be performed independently by two reviewers. Findings will, where possible, be pooled using JBI SUMARI with the meta-aggregation approach. A ConQual Summary of Findings will be presented.

Systematic review registration number:

PROSPERO CRD42020186418
Overview of registries for anaphylaxis: a scoping review protocol
Authors: Stiles Samantha L. , Roche Ingrid , Said Maria , Clifford Rhonda M. , Sanfilippo Frank M. , Loh Richard , Salter Sandra M.
Published: November 2020

Objective:

This review will describe the scope and operational features of global registries for anaphylaxis and assess their contribution to improving knowledge and care of anaphylaxis by measuring their research output.

Introduction:

The incidence of anaphylaxis is increasing around the world. Structured reporting systems, such as patient registries, are needed to better understand the burden of anaphylaxis and protect the growing number of allergic patients.

Inclusion criteria:

The concept to be mapped is registries across the world that enroll patients who have experienced anaphylaxis. Published and gray literature sources will be considered if they describe the scope and operational features of anaphylaxis registries. Only full-text studies published in English will be included. There will be no date restriction.

Methods:

The JBI methodology for scoping reviews will be followed. Embase, MEDLINE, Scopus, and CINAHL will be searched from inception date for relevant articles. Identified keyword and index terms will be adapted for searches of gray literature sources, using Google advanced search functions. The authors and developers of identified registries will be contacted, where possible, to obtain additional information about the development and structure of systems. Data will be extracted by two independent reviewers. Any discrepancies will be resolved by a third reviewer. Tables and a narrative summary will be used to describe and compare the scope and features of anaphylaxis registries and outline their output to assess their contribution to research, clinical practice, and public health policy for anaphylaxis.
Study on Failure Prediction Methodology of Flexible Pipes Under Large Torsion Considering Layer Interaction
Authors: Wu Shanghua , Yang Zhixun , Yin Yuanchao , Lu Qingzhen , Chen Jinlong , Yue Qianjin , Yan Jun , Gao Bo
Published: November 2020

Flexible pipes are distinctive multi-layer structures that are designed to resist different loads when they are utilized in severe deep-water environments. However, they lack a special structural layer to withstand torsion. Tensile armors mainly resist torque although they are designed to bear only tension with the consideration of torque balance. Especially, when a flexible pipe is loaded out from the cargo vessel into the installation vessel, twist angle could be accumulated at high level so that some failure modes will occur due to the large torsion. However, the failure mechanism is very complicated owing to the interaction effect between the different layers. First, the interaction mechanism between the layers of flexible pipes is analyzed under large torsion, and a few potential failure modes are identified, such as the tensile armors strength failure and inner structural layers collapse failure. In addition, to offer a quantitative prediction of the maximum allowable twist angle for flexible pipes, a mechanical model is set up to analyze their torsion behavior. The theoretical descriptions of the involved failure behaviors are investigated, and the theoretical methodology of the failure criteria for predicting the torsion resistance capacity is proposed. Finally, a numerical model is established through experimental verification. The numerical results illustrate that the theoretical prediction methodology is conservative, which can be used to predict the torsion resistance capacity of flexible pipes and to guide their operation and installation in engineering.
Assessment of the Acoustic Reflectometry Technique to Detect Pipe Blockages
Authors: Monteiro Paulo C. C. , da Silva Monteiro Luciana L. , Netto Theodoro Antoun , Vidal J. L. A.
Published: November 2020

Flow assurance is an important aspect of deepwater pipeline design and operation since one of the critical issues is the eventual initiation and growth of hydrate or paraffin blockages under certain conditions. Another relevant problem is the incidence of inorganic scale deposition in oil well production tubes during operation. Offshore operators can obtain enormous benefits if information regarding the position and extent of an eventual blockage is available since mitigation measures can be optimized. This work deals with experimental and numerical simulations of an acoustic system to identify and measure blockages. The technique uses a short duration acoustic pulse that is injected into the pipe. When the pulse encounters an impedance discontinuity, a portion is reflected toward the acoustic source. The analysis of the measured signal reflections can provide valuable data related to the location and size of the blockages. An experimental setup with a steel pipe of 4 in. internal diameter and length of 100 m was developed to evaluate the suitability of the technique for gas pipelines. In parallel, finite element analyses were performed using the commercial software abaqus to simulate the same physical parameters. The experiments were numerically reproduced with good correlation proving the potential of the technique. Subsequently, a parametric study was carried out to examine the acoustic detection capability using different blockage types. Finally, a prototype of the acoustic reflectometry detection system was developed and tested in a full-scale onshore water-filled pipeline to show the feasibility of the method for detecting blockages.
A Novel Combination Algorithm of Different Methods of Maximum Power Point Tracking for Grid-Connected Photovoltaic Systems
Authors: Ali Mahmoud N.
Published: November 2020

This paper proposes a novel algorithm to combine two or more techniques of maximum power point tracking (MPPT) to increase the output dc power and the efficiency of photovoltaic (PV) arrays. Different MPPT methods have dissimilar responses for the same environmental circumstances. The combination of multiple methods has the advantage of ever acquiring maximum power as the environmental conditions change. The proposed algorithm is used to enhance the selection of the most suitable duty cycle of the combined methods, based on the power-voltage characteristics, to get the best tracking response. Multiple classical and/or artificial intelligence (AI)-based MPPT methods can be combined based on this selection algorithm. To demonstrate its effectiveness, two examples are illustrated. The first one is the combination of two classical MPPT methods, which are the incremental conductance (INC) and the perturb-and-observe (P&O). The second example is to combine two AI-based MPPT, which are the artificial neural network (ANN) and the fuzzy logic control (FLC). The simulation results of the application of the proposed algorithm to a grid-connected PV system model justify its capability to acquire better static and dynamic responses than the responses of individual MPPT methods.
Thermodynamic and Economic Assessment of Solar Thermal Power Plants for Cameroon
Authors: Biboum Alain C. , Yilanci Ahmet
Published: November 2020

In this study, it is aimed to conduct the thermodynamic and economic analysis of solar thermal power plants using parabolic trough collectors (PTC), linear Fresnel reflectors (LFR), and solar tower (ST) technologies for Cameroon. The analysis is performed for each power plant with the installed capacity of 5 MWe. Initial investment costs for the solar thermal power plants using PTC, LFR, and ST technologies are estimated to be 33.49 Million USD, 18.77 Million USD, and 36.31 Million USD, while levelized costs of electricity (LCOE) are found to be varying from 145.6 USD/MWh to 186.8 USD/MWh, 112.2 USD/MWh to 154.2 USD/MWh, and 179.2 USD/MWh to 220.4 USD/MWh, respectively. For the solar thermal power plants using PTC, LFR, and ST technologies, payback periods are obtained to be 6.57 years, 6.84 years, and 6.02 years, and also, internal rates on the return are calculated to be 21.03%, 20.42%, and 22.47%, respectively. Overall energy and exergy efficiency values are found to be 13.39% and 14.37%; 11.90% and 13.74%; 12.13% and 13.64% for the solar thermal power plants using PTC, LFR, and ST technologies, respectively. In conclusion, it is seen that LFR technology presents the best performance with the combination of thermodynamic and economic metrics for the deployment of solar thermal power plants in the countries in sub-Saharan Africa like Cameroon.
Magnetohydrodynamics of Lubricant in Recessed Conical Hybrid Journal Bearing With Taper Error
Authors: Kumar Abhishek , Sharma Satish C.
Published: November 2020

To improve the performance accuracy of a conical journal bearing system, the surface error needs to be considered in the analysis since a tiny difference in dimensional values can alter the performance; the consideration of surface error may degrade the performance behavior of bearing. However, a better way to overcome such degradation may be to make use of magnetohydrodynamics (MHDs) of fluid. Therefore, the present work is planned to investigate the impact of taper error and MHD lubricant in recessed conical hybrid journal bearing. In this article, the Reynolds equation is derived under stated assumptions along with frictional power loss expression and finally solved using the finite element analysis, Newton–Raphson method, and generalized minimum residual method. The conducted research helped in determination of optimum values of recess width, land width ratio, and restrictor design parameter, and also obtaining the results corresponding to distinct performance indices. The outcome of these results may inspire practicing designers for the development of better tribo components.
Patient and general practitioner views of tools to delay diagnostic imaging for low back pain: a qualitative study
Authors: Traeger Adrian C , Checketts Juliet , Tcharkhedian Elise , O’Connor Denise A , Klinner Christiane , Sharma Sweekriti , Vyas Parima , Albarqouni Loai , McCaffery Kirsten
Published: November 2020

Objective

Delayed prescribing is a promising strategy to manage patient requests for unnecessary tests and treatments. The purpose of this study was to explore general practitioner (GP) and patient views of three communication tools (Overdiagnosis Leaflet, Dialogue Sheet and ‘Wait-and-see’ Note) to support delayed prescribing of diagnostic imaging.

Design

Qualitative study.

Setting

Primary and emergency care in Sydney, Australia.

Participants

16 GPs and 14 patients with recent episode of low back pain.

Outcome

Views on the tools to delay diagnostic imaging for low back pain. Data were collected using a combination of focus groups and individual interviews.

Analysis

Two researchers independently performed a thematic analysis, and the author team reviewed and refined the analysis.

Results

GP participants responded positively to the Overdiagnosis Leaflet. The Dialogue Sheet and ‘Wait-and-see’ Note raised several concerns about patient pushback, adding to time pressure and being overwhelmed with hard-to-find paper resources. GPs preferred to communicate verbally the reasons to delay an imaging test. For patients, the reactions to the tools were more positive. Patients valued written information and a signed agreement to delay the test. However, patients expressed that a strong desire for diagnostic imaging would likely over-ride any effect of written advice to delay the test. The term ‘false alarm’ to describe overdiagnosis was poorly understood by patients.

Conclusions

GPs and patients agreed that a leaflet about overdiagnosis could support a delayed prescribing approach to imaging for low back pain. The Dialogue Sheet and ‘Wait-and-see’ Note were acceptable to patients but not to GPs.
Measuring the Higgs self-coupling via Higgs-pair production at a 100 TeV p–p collider
Authors: Mangano Michelangelo L. , Ortona Giacomo , Selvaggi Michele
Published: November 2020

Higgs pair production provides a unique handle for measuring the strength of the Higgs self interaction and constraining the shape of the Higgs potential. Among the proposed future facilities, a circular 100 TeV proton–proton collider would provide the most precise measurement of this crucial quantity. In this work, we perform a detailed analysis of the most promising decay channels and derive the expected sensitivity of their combination, assuming an integrated luminosity of 30 $$\hbox {ab}^{-1}$$

ab

-
1

. Depending on the assumed detector performance and systematic uncertainties, we observe that the Higgs self-coupling will be measured with a precision in the range 3.4–7.8% at 68% confidence level.
Charged scalar production at the compact linear collider for the $$S_3 \otimes \mathbb {Z}_2$$ model
Authors: De Conto G. , Machado A. C. B. , Montaño J. , Chimenti P.
Published: November 2020

We present a model with$$S_3 \otimes \mathbb {Z}_2$$S3⊗Z2model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and$$10^{-5}$$10-5pb for the$$e^- e^+ \rightarrow H^+ H^-$$e-e+→H+H-process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the$$e \overline{e} \rightarrow e \overline{e}$$ee¯→ee¯+ missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.
Tests of CPT invariance in gravitational waves with LIGO-Virgo catalog GWTC-1
Authors: Wang Sai , Zhao Zhi-Chao
Published: November 2020

A discovery of gravitational waves from binary black holes raises a possibility that measurements of them can provide strict tests of CPT invariance in gravitational waves. When CPT violation exists, if any, gravitational waves with different circular polarizations could gain a slight difference in propagating speeds. Hence, the birefringence of gravitational waves is induced and there should be a rotation of plus and cross modes. For CPT-violating dispersion relation$${\omega ^{2}=k^{2}}$$ω2=k2$${\pm 2\zeta k^{3}}$$±2ζk3, where a sign$${\pm }$$±denotes different circular polarizations, we find no substantial deviations from CPT invariance in gravitational waves by analyzing a compilation of ten signals of binary black holes in the LIGO-Virgo catalog GWTC-1. We obtain a strict constraint on the CPT-violating parameter, i.e.,$$\zeta =0.14^{+0.22}_{-0.31}\times 10^{-15}\,\text {m}$$ζ=0.14-0.31+0.22×10-15m, which is around two orders of magnitude better than the existing one. Therefore, this study stands for the up-to-date strictest tests of CPT invariance in gravitational waves.
Shake slice and shake concordant links
Authors: Bosman Anthony M.
Published: November 2020

We can construct a [Formula: see text]-manifold by attaching [Formula: see text]-handles to a [Formula: see text]-ball with framing [Formula: see text] along the components of a link in the boundary of the [Formula: see text]-ball. We define a link as [Formula: see text]-shake slice if there exists embedded spheres that represent the generators of the second homology of the [Formula: see text]-manifold. This naturally extends [Formula: see text]-shake slice, a generalization of slice that has previously only been studied for knots, to links of more than one component. We also define a relative notion of shake[Formula: see text]-concordance for links and versions with stricter conditions on the embedded spheres that we call strongly[Formula: see text]-shake slice and strongly[Formula: see text]-shake concordance. We provide infinite families of links that distinguish concordance, shake concordance, and strong shake concordance. Moreover, for [Formula: see text] we completely characterize shake slice and shake concordant links in terms of concordance and string link infection. This characterization allows us to prove that the first non-vanishing Milnor [Formula: see text] invariants are invariants of shake concordance. We also argue that shake concordance does not imply link homotopy.
The special rank of virtual knot groups
Authors: Mira-Albanés Jhon Jader , Rodríguez-Nieto José Gregorio , Salazar-Díaz Olga Patricia
Published: November 2020

In this paper we introduce the special rank for virtual knots and some properties of this number are studied. Although we do not know if it can be considered as a nontrivial extension of the meridional rank given by [H. U. Boden and A. I. Gaudreau, Bridge number for virtual and welded knots, J. Knot Theory Ramifications 24 (2015), Article ID: 1550008] and by [M. Boileau and B. Zimmermann, The [Formula: see text]-orbifold group of a link, Math. Z. 200 (1989) 187–208], we prove that classical knots with special rank [Formula: see text] are [Formula: see text]-bridge knots. Therefore, a modified version of the so called Cappell and Shaneson conjecture could be considered.
A PRINCIPAL–AGENT APPROACH TO CAPACITY REMUNERATION MECHANISMS
Authors: ALASSEUR CLÉMENCE , FARHAT HEYTHEM , SAGUAN MARCELO
Published: November 2020

We propose to study electricity capacity remuneration mechanism design through a principal–agent approach. The principal represents the aggregation of electricity consumers (or a representative entity), subject to the physical risk of shortage, and the agent represents the electricity capacity owners, who invest in capacity and produce electricity to satisfy the demand of consumers, and are subject to financial risks. Following the methodology of [J. Cvitanić, D. Possamaï & N. Touzi (2018) Dynamic programming approach to principal–agent problems, Finance and Stochastics 22(1), 1–37], we propose an optimal contract, from the perspective of consumers, which complements the revenue capacity owners achieved from the spot energy market, and incentivizes both parties to perform an optimal level of investment while sharing the physical and financial risks. Numerical results provide insights on the necessity of a capacity remuneration mechanism and also show how this is especially true when the level of uncertainties on demand or production side increases.
Solving equation systems in ω-categorical algebras
Authors: Bodirsky Manuel , Quinn-Gregson Thomas
Published: November 2020

We study the computational complexity of deciding whether a given set of term equalities and inequalities has a solution in an [Formula: see text]-categorical algebra [Formula: see text]. There are [Formula: see text]-categorical groups where this problem is undecidable. We show that if [Formula: see text] is an [Formula: see text]-categorical semilattice or an abelian group, then the problem is in P or NP-hard. The hard cases are precisely those where [Formula: see text] has a uniformly continuous minor-preserving map to the clone of projections on a two-element set. The results provide information about algebras [Formula: see text] such that [Formula: see text] does not satisfy this condition, and they are of independent interest in universal algebra. In our proofs we rely on the Barto–Pinsker theorem about the existence of pseudo-Siggers polymorphisms. To the best of our knowledge, this is the first time that the pseudo-Siggers identity has been used to prove a complexity dichotomy.
Generalized Sidelobe Canceller Beamforming with Combined Postfilter and Sparse NMF for Speech Enhancement
Authors: Priyanka S. Siva , Kumar T. Kishore
Published: November 2020

A multi-microphone array speech enhancement method using Generalized Sidelobe Canceller (GSC) beamforming with Combined Postfilter (CP) and Sparse Non-negative Matrix Factorization (SNMF) is proposed in this paper. GSC beamforming with CP and SNMF is implemented to reduce directional noise, diffuse noise, residual noise and to separate interferences in adverse environment. In this paper, the directional noise is reduced using GSC beamforming, whereas the diffuse noise in each subband is reduced with a combined postfilter using Unconstrained Frequency domain Normalized Least Mean Square (UFNLMS) algorithm. Finally, the residual noise at the output of CP is eliminated by SNMF which optimizes the noise. The performance of the proposed method is evaluated using parameters like PESQ, SSNR, STOI, SDR and LSD. The noise reduction for four and eight microphones is compared and illustrated in spectrograms. The proposed method shows better performance in terms of intelligibility and quality when compared to the existing methods in adverse environments.
*-Controlled frames in Hilbert C*-modules
Authors: Shateri Tayebe Lal
Published: November 2020

The main purpose of this paper is to introduce the notion of *-T-controlled frames in Hilbert [Formula: see text]-modules. We present some results of frames in the view of *-T-controlled frames in Hilbert [Formula: see text]-modules. Also, we define *-w-frames and give their relations to *-T-controlled frames and multiplier operators.
Transformation of FASTA files into feature vectors for unsupervised compression of short reads databases
Authors: Tang Tao , Li Jinyan
Published: November 2020

FASTA data sets of short reads are usually generated in tens or hundreds for a biomedical study. However, current compression of these data sets is carried out one-by-one without consideration of the inter-similarity between the data sets which can be otherwise exploited to enhance compression performance of de novo compression. We show that clustering these data sets into similar sub-groups for a group-by-group compression can greatly improve the compression performance. Our novel idea is to detect the lexicographically smallest k-mer (k-minimizer) for every read in each data set, and uses these k-mers as features and their frequencies in every data set as feature values to transform these huge data sets each into a characteristic feature vector. Unsupervised clustering algorithms are then applied to these vectors to find similar data sets and merge them. As the amount of common k-mers of similar feature values between two data sets implies an excessive proportion of overlapping reads shared between the two data sets, merging similar data sets creates immense sequence redundancy to boost the compression performance. Experiments confirm that our clustering approach can gain up to 12% improvement over several state-of-the-art algorithms in compressing reads databases consisting of 17–100 data sets (48.57–197.97[Formula: see text]GB).
Digital quantum simulation of hadronization in Yang–Mills theory
Authors: Li De-Sheng , Wu Chun-Wang , Zhong Ming , Wu Wei , Chen Ping-Xing
Published: November 2020

A quantum algorithm of SU([Formula: see text]) Yang–Mills theory is formulated in terms of quantum circuits. It can nonperturbatively calculate the Dyson series and scattering amplitudes with polynomial complexity. The gauge fields in the interaction picture are discretized on the same footing with the lattice fermions in momentum space to avoid the fermion doubling and the gauge symmetry breaking problems. Applying the algorithm to the quantum simulation of quantum chromodynamics, the quark and gluon’s wave functions evolved from the initial states by the interactions can be observed and the information from wave functions can be extracted at any discrete time. This may help us understand the natures of the hadronization which has been an outstanding question of significant implication on high energy phenomenological studies.
Thermodynamics of non-commutative scalar-tensor-vector gravity black holes
Authors: Saghafi Sara , Nozari Kourosh , Hajebrahimi Milad
Published: November 2020

In this paper, we analyze the thermodynamic stability of Schwarzschild Modified Gravity (MOG) black holes in a non-commutative framework. We show that, unlike a commutative MOG black hole, in the coherent state picture of non-commutativity MOG black holes are thermodynamically stable. At the final stage of evaporation a stable remnant with zero temperatures and finite entropy is left in this non-commutative framework. Also, we consider the Parikh–Wilczek tunneling mechanism of massive particles from non-commutative MOG black holes and demonstrate that information leaks out of non-commutative MOG black holes in the form of some non-thermal correlations.
SIR model with time-varying contact rate
Authors: Al-Salti Nasser , Al-Musalhi Fatma , ELmojtaba Ibrahim , Gandhi Vilmurugan
Published: November 2020

The contact rate is defined as the average number of contacts adequate for disease transmission by an individual per unit time and it is usually assumed to be constant in time. However, in reality, the contact rate is not always constant throughout the year due to different factors such as population behavior, environmental factors and many others. In the case of serious diseases with a high level of infection, the population tends to reduce their contacts in the hope of reducing the risk of infection. Therefore, it is more realistic to consider it to be a function of time. In particular, the study of models with contact rates decreasing in time is well worth exploring. In this paper, an SIR model with a time-varying contact rate is considered. A new form of a contact rate that decreases in time from its initial value till it reaches a certain level and then remains constant is proposed. The proposed form includes two important parameters, which represent how far and how fast the contact rate is reduced. These two parameters are found to play important roles in disease dynamics. The existence and local stability of the equilibria of the model are analyzed. Results on the global stability of disease-free equilibrium and transcritical bifurcation are proved. Numerical simulations are presented to illustrate the theoretical results and to demonstrate the effect of the model parameters related to the behavior of the contact rate on the model dynamics. Finally, comparisons between the constant, variable contact rate and variable contact rate with delay in response cases are presented.
Assessing the lifetime performance index of weighted Lomax distribution based on progressive type-II censoring scheme for bladder cancer
Authors: Ramadan Dina A.
Published: November 2020

In this paper, Health-related quality of life has not been adequately measured in bladder cancer. A recently developed reliable and disease-specific quality of life instrument (Bladder Cancer Index, BCI) was used to measure. Progressive type II censoring schemes have potential usefulness in practice where budget constraints in place or there is a necessity for the speedy test. To test the process capability, the lifetime performance index [Formula: see text] is widely recommended for evaluating the performance of the product’s lifetime and evaluating the lifetime performance index [Formula: see text] for the three-parameter Weighted-Lomax distribution (WLx) under progressive type-II censoring sample for a lower specification limit ([Formula: see text]). The statistical inference concerning [Formula: see text] is conducted via obtaining the maximum likelihood of [Formula: see text] on the base of progressive type-II censoring. The asymptotic normal distribution of the MLE of [Formula: see text] and the confidence interval is proposed. Moreover, the hypothesis testing of [Formula: see text] for evaluating the lifetime performance of WLx data is conducted. Also, assuming the conjugate prior distribution and squared error loss function, this study constructs a Bayes estimator of [Formula: see text]. The Bayes estimator of [Formula: see text] is then utilized to develop a credible interval in the condition of known [Formula: see text]. Moreover, we propose a Bayesian test to assess the lifetime performance of products. We also propose a Bayesian test to assess the lifetime performance of products. Finally, two examples are given, one of them is considering a real life data of the remission times of bladder cancer patients in endurance lifetime test and the other is a simulated example to illustrate the usage of the proposed procedure.