bluuebunny/crossref_metadata_2025 huggingface dataset:
Note on some representations of general solutions to homogeneous linear difference equations
Authors: Stević Stevo , Iričanin Bratislav , Kosmala Witold , Šmarda Zdeněk
Published: September 2020

It is known that every solution to the second-order difference equation$x_{n}=x_{n-1}+x_{n-2}=0$xn=xn−1+xn−2=0,$n\ge 2$n≥2, can be written in the following form$x_{n}=x_{0}f_{n-1}+x_{1}f_{n}$xn=x0fn−1+x1fn, where$f_{n}$fnis the Fibonacci sequence. Here we find all the homogeneous linear difference equations with constant coefficients of any order whose general solution have a representation of a related form. We also present an interesting elementary procedure for finding a representation of general solution to any homogeneous linear difference equation with constant coefficients in terms of the coefficients of the equation, initial values, and an extension of the Fibonacci sequence. This is done for the case when all the roots of the characteristic polynomial associated with the equation are mutually different, and then it is shown that such obtained representation also holds in other cases. It is also shown that during application of the procedure the extension of the Fibonacci sequence appears naturally.
Correction to: Use of medical face masks versus particulate respirators as a component of personal protective equipment for health care workers in the context of the COVID-19 pandemic
Authors: Conly John , Seto W. H. , Pittet Didier , Holmes Alison , Chu May , Hunter Paul R. ,   on behalf of the WHO Infection Prevention and Control Research and Development Expert Group for COVID-19
Published: September 2020

An amendment to this paper has been published and can be accessed via the original article.
An Anchorage Technique for Shear Strengthening of RC T-Beams Using NSM-BFRP Bars and BFRP Sheet
Authors: Diab Hesham M. , Sayed Ahmed M.
Published: September 2020

This study presents a detailed experimental program for reinforced concrete T-beams strengthened in shear with near-surface mounted (NSM) basalt fiber-reinforced polymer (BFRP) bars. This paper aims to introduce and evaluate a nonmechanical anchorage technique for shear strengthening using NSM-BFRP bars. T-beams were strengthened using manually manufactured closed or U-shaped hybrid BFRP stirrups (BFRP bars and BFRP sheets). The experimental program was developed to study the effects of these anchorage techniques. The results showed that the shear capacity increased by 8%–46% for beams strengthened with NSM-BFRP bars without anchorage. However, the presence of the proposed anchorage system increased the shear capacity of the strengthened beams by 39.6%–81.6%. Moreover, the maximum strains induced in the BFRP bars ranged from 27 to 59% of their ultimate strains according to the spacing between the NSM and the presence of the anchorage. The proposed anchorage technique prevented the premature debonding of the NSM-BFRP bars.
Meta-modeling of a simulation chain for urban air quality
Authors: Hammond J. K. , Chen R. , Mallet V.
Published: September 2020

Urban air quality simulation is an important tool to understand the impacts of air pollution. However, the simulations are often computationally expensive, and require extensive data on pollutant sources. Data on road traffic pollution, often the predominant source, can be obtained through sparse measurements, or through simulation of traffic and emissions. Modeling chains combine the simulations of multiple models to provide the most accurate representation possible, however the need to solve multiple models for each simulation increases computational costs even more. In this paper we construct a meta-modeling chain for urban atmospheric pollution, from dynamic traffic modeling to air pollution modeling. Reduced basis methods (RBM) aim to compute a cheap and accurate approximation of a physical state using approximation spaces made of a suitable sample of solutions to the model. One of the keys of these techniques is the decomposition of the computational work into an expensive one-time offline stage and a low-cost parameter-dependent online stage. Traditional RBMs require modifying the assembly routines of the computational code, an intrusive procedure which may be impossible in cases of operational model codes. We propose a non-intrusive reduced order scheme, and study its application to a full chain of operational models. Reduced basis are constructed using principal component analysis (PCA), and the concentration fields are approximated as projections onto this reduced space. We use statistical emulation to approximate projection coefficients in a non-intrusive manner. We apply a multi-level meta-modeling technique to a chain using the dynamic traffic assignment model LADTA, the emissions database COPERT IV, and the urban dispersion-reaction air quality model SIRANE to a case study on the city of Clermont-Ferrand with over 45, 000 daily traffic observations, a 47, 000-link road network, a simulation domain covering $$180\,\text {km}^2$$

180

km
2

. We assess the results using hourly NO$$_2$$

2

concentration observations measured at stations in the agglomeration. Computational times are reduced from nearly 3 h per simulation to under 0.1 s, while maintaining accuracy comparable to the original models. The low cost of the meta-model chain and its non-intrusive character demonstrate the versatility of the method, and the utility for long-term or many-query air quality studies such as epidemiological inquiry or uncertainty quantification.
Combined application of single-energy metal artifact reduction and reconstruction techniques in patients with Cochlear implants
Authors: Wei Fanqin , Li Jiahui , Zhou Chunxiang , Li Yun , Wang Xianren , Huang Bixue , Sun Qiyang , Xiong Guanxia
Published: September 2020

Background

The purpose of this study was to develop an effective method of reducing metal artifacts in cochlear implant (CI) electrodes.

Methods

The temporal bones of 30 patients (34 ears) after CI were examined with 320-detector row computed tomography, which was evaluated by two senior radiologists using a double-blind method. Noise, artifact index, signal-to-noise ratio, and the subjective image quality score were compared before versus after using single-energy metal artifact reduction (SEMAR). The electrode position, single electrode visibility, and electrode count were evaluated using SEMAR combined with either multi-planar reconstruction (MPR) or maximum intensity projection.

Results

The two radiologists’ measurements had good consistency. SEMAR significantly reduced the image noise and artifacts index and significantly improved the signal-to-noise ratio and subjective image quality score ( P < 0.01). The combination of SEMAR with MPR was conducive to accurate assessment of electrode position and single-electrode visibility. The combination of SEMAR with MIP facilitated accurate and intuitive matching of the assessed electrode count with the number of electrodes implanted during the operation ( P = 0.062).

Conclusion

SEMAR significantly reduces metal artifacts generated by CI electrodes and improves the quality of computed tomography images. The combination of SEMAR with MPR and maximum intensity projection is beneficial for evaluating the position and number of CI electrodes.
Assessing motivation and learning strategy usage by dually enrolled students
Authors: Day Molly C. , Kelley Heather M. , Browne Blaine L. , Kohn Steven J.
Published: September 2020

Theoretical frameworks grounded in the social cognitive theory are used to discuss the need for assessing motivation, self-efficacy for learning and performance, metacognitive self-regulation of dually enrolled students. This study assessed motivation and learning strategy usage by Dually Enrolled Students participating in Georgia’s Dual Enrollment program. The research was conducted on 213 high school aged 14 to 18 years, in grades 9–12, and attended a high school in a seven-county service area in southwest Georgia. Participants all were taking classes under a program that allows them to simultaneously earn high school and college credit, and required them to attend a high school and college concurrently either at a technical college of the Technical System of Georgia, or a state college of the University System of Georgia. The research questions were answered using a cross-sectional survey, the Motivated Strategies for Learning Questionnaire, and demographics were used to classify participants based on age, grade, gender, number of classes completed in the Dual Enrollment program, teacher type for instruction, and the format/location of college class taken. The study’s findings added to the existing knowledge base regarding teenage students who are expected to conform to the role of college student simply because they were deemed academically equipped to take college classes. Furthermore, the findings of this study suggest the importance of implementing additional acceptance requirements to make sure students possess the maturity, motivation, and learning strategy application knowledge to be successful in college classes and that faculty has been trained to accommodate the learning needs of this specific type of learner.
“N”-shaped Y/X coda spectral ratio observed for in-line-type OBS networks; S-net and ETMC: interpretation based on natural vibration of pressure vessel
Authors: Sawazaki Kaoru , Nakamura Takeshi
Published: September 2020

We have identified “N”-shaped Y/X amplitude spectral ratios in S-coda records from a significant number of OBSs (ocean bottom seismometers) belonging to in-line-type ocean bottom networks of S-net and ETMC deployed around the Japan Trench and Sagami Trough, respectively. The “N”-shape reflects a sharp peak and notch at approximately 5–13 Hz and 10–23 Hz, respectively. This shape does not characterize OBSs belonging to node-type ocean bottom network of DONET deployed near the Nankai Trough. For S-net stations, the “N”-shape is not clearly formed for stations installed within grooves dug in the seafloor. We interpret the “N”-shaped Y/X amplitude spectral ratio is caused by the natural vibrations of a cylindrical pressure vessel that is placed sideways (long-axis lies in the horizontal plane) on the seafloor. The notch and peak frequencies in the Y/X amplitude spectral ratio likely correspond to natural frequencies of longitudinal (X-direction) and torsional and/or bending (Y-direction) vibrations, respectively. These natural vibrations are not observed for buried OBSs or those installed within grooves in the seafloor probably because they are better coupled to the seafloor. We propose a simple model to evaluate the extent to which the peak and notch have formed, which depends on the natural frequencies and coupling of the pressure vessel. We suggest users of in-line-type OBSs carefully examine if there are different responses between the X and Y components when frequencies about > 3 Hz are used. When installing OBS networks in the future, installing OBSs and cables within grooves dug in the seafloor or by burial will be effective in suppressing such natural vibrations.
A five year trend analysis of malaria prevalence in Guba district, Benishangul-Gumuz regional state, western Ethiopia: a retrospective study
Authors: Alkadir Shemsia , Gelana Tegenu , Gebresilassie Araya
Published: September 2020

Background

In Ethiopia, malaria is a serious public health concern and has great impact on socio-economy. The trend analysis of malaria data from health facilities is useful for understanding its transmission dynamics and implementing evidence-based malaria control strategies. The aim of this study was to determine the trends of malaria infection in Guba district, western Ethiopia.

Methods

A retrospective study was undertaken at Mankush Health Centre, western Ethiopia. All malaria cases reported from 2014 to 2018 were carefully reviewed from the laboratory record books to determine the trends of malaria morbidity. Data were analyzed using SPSS version 20.0.

Results

In total, 16,964 malaria suspects were diagnosed using microscopy over the last 5 years, of which 8658 (51.04%) were confirmed positive cases.Plasmodium falciparum,P. vivax, and mixed infection (both species) accounted for 75.2, 24.5 and 0.28% of the cases, respectively. Males patients were more affected (n = 5028, 58.1%) than female ones (n = 3630, 41.9%). Of the total confirmed cases, 60.4% were age group of subjects (≥ 15 years) followed by 22.6% of 5–14 years and 15.9% of under 5 years. High malaria prevalence was observed in spring (September to November) season, while the least was observed in autumn (March to May) with the prevalence of 45.6 and 11.5%, respectively.

Conclusions

The study demonstrated that malaria is a public health concern, in whichP. falciparumis the predominant species followed byP. vivax. Therefore, the district health bureau and other concerned stakeholders should strength evidence-based malaria control and prevention interventions to interrupt disease transmission and eventual reduction malaria of malaria cases in Guba district.
Evaluation of a clinical pharmacist team-based telehealth intervention in a rural clinic setting: a pilot study of feasibility, organizational perceptions, and return on investment
Authors: Murry Logan T. , Parker Christopher P. , Finkelstein Rachel J. , Arnold Matthew , Kennelty Korey
Published: September 2020

Background

Remote, centralized clinical pharmacist services provided by board-certified clinical pharmacists have been shown to effectively assist in chronic disease management. We assess the feasibility of implementing a pharmacist-led, remote, centralized pharmacy service to improve A1c levels in patient with diabetes in a rural clinic setting.

Methods

This was a non-randomized pilot and feasibility study. Participants were enrolled in a pharmacist-led telehealth intervention service, with data prior to enrollment used as baseline data for control. To be included, patients needed to have A1c readings of greater than 7% to be considered uncontrolled. A1c changes were reported for two groups based on A1c ranges: between 7 and 10% and ≥ 10%. Clinical pharmacists and clinical pharmacy interns initiated contact with patients via telephone communication and managed the patients remotely. The following outcomes were evaluated: organization perceptions (patients, providers, and clinic staff), changes in A1c, medication discrepancies, impact of an internally operated Patient Assistance Program, and potential return on investment (ROI).

Results

Fifty-two patients were initially identified and referred to the service with 43 patients consenting to participate in the intervention. Patient and provider survey responses were recorded. In the initial analysis occurring during the first 3 to 5 months of the program, there was considerable improvement in diabetes control as measured by A1c. For patients with uncontrolled diabetes with a baseline A1c > 7% but less than < 10% and ≥ 10%, the intervention resulted in an A1c decrease of 0.57% and 2.55%, respectively. Clinical pharmacists and clinical pharmacy interns identified at least one medication discrepancy in 44% of patients, with number of discrepancies ranging from 1 to 5 per patient. At the conclusion of the study window, 42 potentially billable encounters were documented, which would have generated a net profit of $1140 USD, had they been submitted for reimbursement. Given the potential revenue generation, the service theoretically yields a ROI of 1.4 to 1.

Conclusions

Initial results suggest that a pharmacist-led telehealth intervention has potential to decrease A1c levels in patients with diabetes, assist in identification of medication discrepancies, provide a positive return on investment for rural clinics, and potentially increase reimbursement for providers and clinics tasked with managing patients with uncontrolled diabetes.
Optimal growth under socially responsible investment: a dynamic theoretical model of the trade-off between financial gains and emotional rewards
Authors: Gomes Orlando
Published: September 2020

Socially responsible investment (SRI) evolved, along the last two decades, from an almost unexplored topic in science to a recurrent theme of research and debate in Economics and Finance. The growing interest on the theme has two fundamental causes. On one hand, empirical evidence unveils a change of behavior of investors, who typically no longer restrict their decision-making to a strict financial analysis; ethical, social, environmental, and political concerns are also on the forefront of investors’ assessments. On the other hand, the economic science is witnessing a paradigm shift characterized by a progressive departure from the orthodox rational deliberation framework and in the direction of the introduction of behavioral elements. In this study, an intertemporal model is proposed to serve as a benchmark for the evaluation of the implications of social and environmental awareness upon investors’ decisions and investment performance. The model is a simple optimal control framework that highlights the trade-off between financial returns and the satisfaction emanating from investing in firms or projects guided by ethical values and by good governance principles. Better financial outcomes may come with a social damage that the representative agent in the model will include, with a negative sign, in her utility function. Long-term steady-state results and transitional dynamics are duly evaluated for neoclassical and endogenous growth versions of the model.
A feature fusion technique for improved non-intrusive load monitoring
Authors: Reddy Raghunath , Garg Vishal , Pudi Vikram
Published: September 2020

Load identification is an essential step in Non-Intrusive Load Monitoring (NILM), a process of estimating the power consumption of individual appliances using only whole-house aggregate consumption. Such estimates can help consumers and utility companies improve load management and save power. Current state-of-the-art methods for load identification generally use either steady state or transient features for load identification. We hypothesize that these are complementary features and so a hybrid combination of them will result in an improved appliance signature. We propose a novel hybrid combination that has the advantage of being low-dimensional and can thus be easily integrated with existing classification models to improve load identification. Our improved hybrid features are then used for building appliance identification models using Naive Bayes, KNN, Decision Tree and Random Forest classifiers. The proposed NILM methodology is evaluated for robustness in changing environments. An automated data collection setup is established to capture 7 home appliances aggregate data under varying voltages. Experimental results show that our proposed feature fusion based algorithms are more robust and outperform steady state and transient feature-based algorithms by at least +9% and +15% respectively.
Evaluating of the association between ABO blood groups and coronavirus disease 2019 (COVID-19) in Iraqi patients
Authors: Ad’hiah Ali H. , Allami Risala H. , Mohsin Raghdan H. , Abdullah Maha H. , AL-Sa’ady Ali J. R. , Alsudani Mustafa Y.
Published: September 2020

Background

Susceptibility to the pandemic coronavirus disease 2019 (COVID-19) has recently been associated with ABO blood groups in patients of different ethnicities. This study sought to understand the genetic association of this polymorphic system with risk of disease in Iraqi patients. Two outcomes of COVID-19, recovery and death, were also explored. ABO blood groups were determined in 300 hospitalized COVID-19 Iraqi patients (159 under therapy, 104 recovered, and 37 deceased) and 595 healthy blood donors. The detection kit for 2019 novel coronavirus (2019-nCoV) RNA (PCR-Fluorescence Probing) was used in the diagnosis of disease.

Results

Mean age was significantly increased in patients compared to controls (49.8 ± 11.7 vs. 28.9 ± 6.6 years; p < 0.001). A similar observation was made in recovered (42.1 ± 10.4 vs. 28.9 ± 6.6 years; p < 0.001) and deceased (53.6 ± 9.7 vs. 28.9 ± 6.6 years; p < 0.001) cases. The mean age was also significantly increased in deceased cases compared to recovered cases (53.6 ± 9.7 vs. 42.1 ± 10.4 years; p < 0.001). There were gender-dependent differences in COVID-19 prevalence. The percentage of COVID-19 was higher in males than in females (all cases: 59.7 vs. 40.3%; recovered cases: 55.8 vs. 44.2%). Such male-gender preponderance was more pronounced in deceased cases (67.6 vs. 32.4%). Logistic regression analysis revealed that groups AB and B + AB were significantly associated with increased risk to develop COVID-19 (OR = 3.10; 95% CI 1.59–6.05; pc = 0.007 and OR = 2.16; 95% CI 1.28–3.63; pc = 0.028, respectively). No ABO-associated risk was observed in recovered cases. On the contrary, groups A (OR = 14.60; 95% CI 2.85–74.88; pc = 0.007), AB (OR = 12.92; 95% CI 2.11–79.29; pc = 0.042), A + AB (OR = 14.67; 95% CI 2.98–72.33; pc = 0.007), and A + B + AB (OR = 9.67; 95% CI 2.02–46.24; pc = 0.035) were associated with increased risk of death in deceased cases.

Conclusions

The findings of this study suggest that group AB may be a susceptibility biomarker for COVID-19, while group A may be associated with increased risk of death.
A flexible model for studying fringe field effect on parallel plate actuators
Authors: Elshenety Ahmad , El-Kholy E. E. , Abdou Ahmed F. , Soliman Mostafa , Elhagry Mohsen M.
Published: September 2020

Electrostatic parallel plate actuators are common in micro-electro-mechanical systems due to their compatibility with micro-fabrication technology. Parallel plate actuators suffer from an instability problem called the pull-in phenomenon that happens when the applied DC voltage exceeds a certain value called the static pull-in voltage. The value of this critical voltage is important in many applications that depend on parallel plate actuators such as switches and static gas sensors. The fringe field around the edges of the plates could severely affect the performance of the actuator. This paper introduces a new model for the parallel plate actuator to calculate the value of static pull-in voltage. The proposed model considers the fringe field between the two plates. The static pull-in voltage of some PolyMUMPs actuators is practically measured and compared to the simulation results that involve the fringe field effect. The model is simulated using MATLAB to show the influence of that field on the static pull-in voltage. The MATLAB results of the proposed model are validated with ANSYS.
Drainage of transudative pleural effusion: how does it affect weaning from mechanical ventilation?
Authors: Gharraf Heba Said , AbdAllah Alaa El Din
Published: September 2020

Background

Pleural collections of the transudative type occur frequently in patients who need mechanical ventilation (MV). Treatment of the etiology of the effusion takes a prolonged duration of time. The study intended to assess the effect of transudative effusion drainage through chest tube on the process of weaning from MV.

Results

No statistically significant difference was found between the two studied groups regarding age, sex, and comorbidities. Total duration of MV was significantly shorter in patients of group I compared with patients of group II (P = 0.002). Successful weaning from MV within 2 days after the start of the study was statistically significantly more achieved in patients of group I (56.7%) compared with patients of group II (23.3%) (P = 0.017). One and 3 days after beginning of the study, patients in group I showed a significant improvement in oxygenation as demonstrated by a statistically significantly higher value of PaO2/FiO2 ratio compared with patients of group II (P = 0.003 and 0.008, respectively).

Conclusion

More work is needed to determine the physiological benefits of transudate pleural effusion drainage and the effect of the specific procedure on the clinical parameters. Further studies are needed to study different modalities or tools of drainage of transudate effusion and the effect of each on the different clinical outcomes in comparison with each other to reach the optimum way of drainage of transudate effusion with the best results and least complications.
Addressing concerns about smoking cessation and mental health: theoretical review and practical guide for healthcare professionals
Authors: Taylor Gemma M. J. , Baker Amanda L. , Fox Nadine , Kessler David S. , Aveyard Paul , Munafò Marcus R.
Published: September 2020

Smoking rates in people with depression and anxiety are twice as high as in the general population, even though people with depression and anxiety are motivated to stop smoking. Most healthcare professionals are aware that stopping smoking is one of the greatest changes that people can make to improve their health. However, smoking cessation can be a difficult topic to raise. Evidence suggests that smoking may cause some mental health problems, and that the tobacco withdrawal cycle partly contributes to worse mental health. By stopping smoking, a person's mental health may improve, and the size of this improvement might be equal to taking antidepressants. In this article we outline ways in which healthcare professionals can compassionately and respectfully raise the topic of smoking to encourage smoking cessation. We draw on evidence-based methods such as cognitive–behavioural therapy (CBT) and outline approaches that healthcare professionals can use to integrate these methods into routine care to help their patients stop smoking.
Hypofractionated Versus Standard Fractionated Radiotherapy in Patients With Early Breast Cancer or Ductal Carcinoma In Situ in a Randomized Phase III Trial: The DBCG HYPO Trial
Authors: Offersen Birgitte V. , Alsner Jan , Nielsen Hanne M. , Jakobsen Erik H. , Nielsen Mette H. , Krause Mechthild , Stenbygaard Lars , Mjaaland Ingvil , Schreiber Andreas , Kasti Unn-Miriam , Overgaard Jens ,   on behalf of the Danish Breast Cancer Group Radiation Therapy Committee
Published: September 2020

PURPOSE

Given the poor results using hypofractionated radiotherapy for early breast cancer, a dose of 50 Gy in 25 fractions (fr) has been the standard regimen used by the Danish Breast Cancer Group (DBCG) since 1982. Results from more recent trials have stimulated a renewed interest in hypofractionation, and the noninferiority DBCG HYPO trial (ClincalTrials.gov identifier: NCT00909818 ) was designed to determine whether a dose of 40 Gy in 15 fr does not increase the occurrence of breast induration at 3 years compared with a dose of 50 Gy in 25 fr.

PATIENTS AND METHODS

One thousand eight hundred eighty-two patients > 40 years of age who underwent breast-conserving surgery for node-negative breast cancer or ductal carcinoma in situ (DCIS) were randomly assigned to radiotherapy at a dose of either 50 Gy in 25 fr or 40 Gy in 15 fr. The primary end point was 3-year grade 2-3 breast induration assuming noninferiority regarding locoregional recurrence.

RESULTS

A total of 1,854 consenting patients (50 Gy, n = 937; 40 Gy, n = 917) were enrolled from 2009-2014 from eight centers. There were 1,608 patients with adenocarcinoma and 246 patients with DCIS. The 3-year rates of induration were 11.8% (95% CI, 9.7% to 14.1%) in the 50-Gy group and 9.0% (95% CI, 7.2% to 11.1%) in the 40-Gy group (risk difference, −2.7%; 95% CI, −5.6% to 0.2%; P = .07). Systemic therapies and radiotherapy boost did not increase the risk of induration. Telangiectasia, dyspigmentation, scar appearance, edema, and pain were detected at low rates, and cosmetic outcome and patient satisfaction with breast appearance were high with either no difference or better outcome in the 40-Gy cohort compared with the 50-Gy cohort. The 9-year risk of locoregional recurrence was 3.3% (95% CI, 2.0% to 5.0%) in the 50-Gy group and 3.0% (95% CI, 1.9% to 4.5%) in the 40-Gy group (risk difference, −0.3%; 95% CI, −2.3% to 1.7%). The 9-year overall survival was 93.4% (95% CI, 91.1% to 95.1%) in the 50-Gy group and 93.4% (95% CI, 91.0% to 95.2%) in the 40-Gy group. The occurrence of radiation-associated cardiac and lung disease was rare and not influenced by the fractionation regimen.

CONCLUSION

Moderately hypofractionated breast irradiation of node-negative breast cancer or DCIS did not result in more breast induration compared with standard fractionated therapy. Other normal tissue effects were minimal, with similar or less frequent rates in the 40-Gy group. The 9-year locoregional recurrence risk was low.
MSclassifier: median-supplement model-based classification tool for automated knowledge discovery
Authors: Adabor Emmanuel S. , Acquaah-Mensah George K. , Mazandu Gaston K.
Published: September 2020

High-throughput technologies have resulted in an exponential growth of publicly available and accessible datasets for biomedical research. Efficient computational models, algorithms and tools are required to exploit the datasets for knowledge discovery to aid medical decisions. Here, we introduce a new tool, MSclassifier, based on median-supplement approaches to machine learning to enable an automated and effective binary classification for optimal decision making. The MSclassifier package estimates medians of features (attributes) to deduce supplementary data, which is subsequently introduced into the training set for balancing and building superior models for classification. To test our approach, it is used to determine HER2 receptor expression status phenotypes in breast cancer and also predict protein subcellular localization (plasma membrane and nucleus). Using independent sample and cross-validation tests, the performance of MSclassifier is evaluated and compared with well established tools that could perform such tasks. In the HER2 receptor expression status phenotype identification tasks, MSclassifier achieved statistically significant higher classification rates than the best performing existing tool (90.30% versus 89.83%, p=8.62e-3). In the subcellular localization prediction tasks, MSclassifier and one other existing tool achieved equally high performances (93.42% versus 93.19%, p=0.06) although they both outperformed tools based on Naive Bayes classifiers. Overall, the application and evaluation of MSclassifier reveal its potential to be applied to varieties of binary classification problems. The MSclassifier package provides an R-portable and user-friendly application to a broad audience, enabling experienced end-users as well as non-programmers to perform an effective classification in biomedical and other fields of study.
Impact of sin taxes on consumption volumes of sweetened beverages and soft drinks in Saudi Arabia
Authors: Megally Rania , Al-Jawaldeh Ayoub
Published: September 2020

Background: The consumption of sweetened drinks plays a major role in increasing the burden of diseases such as obesity and cardiovascular diseases. The prevalence rate of obesity and overweight individuals in Saudi Arabia has increased alarmingly among children over the past decade, revealing a crucial need the initiate and monitor effective prevention measures of obesity. Hence, this paper aims to measure the impact of sin taxes of sugar-sweetened beverages on the consumption level of such beverages in Saudi Arabia. Building enough evidence to guide other countries in the Eastern Mediterranean Region (EMR) on how to reduce the level of sugar intake consumption to reduce obesity and malnutrition has an impact on the economy as a whole.

Methods: The excise taxes on sugar-sweetened beverages were applied in 2017. The impact of this was measured using a time series data set that covered sales volumes of soft drinks in Saudi Arabia from 2010 to 2020.

Results: Sin taxes had a significant negative impact on the sales volume over the years. A significance level of <1% was found as sales volume of soft drinks decreased by 57.64% from 2010 to 2017 when sin taxes were applied on energy and soft drinks.

Conclusions: Sin tax policy is recommended to other countries in the EMR to reduce obesity levels among children. These recommendations advocate the recommended priority actions by the World Health Organization for the strategy on nutrition for the EMR 2020-2030.
Infection prevention and control during the COVID-19 pandemic: challenges and opportunities for Kenyan public hospitals
Authors: Maina Michuki , Tosas-Auguet Olga , English Mike , Schultsz Constance , McKnight Jacob
Published: September 2020

Background: Infection prevention and control, and water sanitation and hygiene have an essential role in ensuring the quality of care and patient outcomes in hospitals. Using a modification of the World Health Organization’s water sanitation and hygiene facility improvement tool, we undertook assessments in 14 public hospitals in Kenya in 2018. The hospitals received written feedback on areas where they could make improvements. Following the first confirmed cases of COVID-19 in Kenya, we were drawn to ask whether the results of our pre-pandemic survey had led to action, and whether or not the threat of COVID-19 had focused more attention on infection prevention and control and water sanitation and hygiene.

Methods: Using a semi-structured interview guide, we carried out phone interviews with key hospital leaders in 11 of the 14 hospitals. The data were transcribed and coded into thematic areas. We draw on these interviews to describe the status and awareness of infection prevention and control.

Results: The infection prevention and control committee members are training health workers on infection prevention and control procedures and proper use of personal protective equipment and in addition, providing technical support to hospital managers. While some hospitals have also accessed additional funds to improve infection prevention and control, they tended to be small amounts of money.  Long-standing challenges with supplies of infection prevention and control materials and low staff morale persist.  Crucially, the reduced supply of personal protective equipment has led to fear and anxiety among health care personnel.

Conclusions: As funds are mobilised to support care for COVID-19, we ask that funds prioritise infection prevention and control measures. This would have a profoundly positive effect on within hospital virus transmission, patient and staff safety but also lasting benefits beyond the COVID-19 pandemic.
Lissajous scanning structured illumination microscopy
Authors: Kim Hyunwoo , Seo Yeong-Hyeon , Jeon Jaehun , Jeong Ki-Hun
Published: September 2020

High-resolution fluorescent microscopic imaging techniques are in high demand to observe detailed structures or dynamic mechanisms of biological samples. Structured illumination microscopy (SIM) has grabbed much attention in super-resolution imaging due to simple configuration, high compatibility with common fluorescent molecules, and fast image acquisition. Here, we report Lissajous scanning SIM (LS-SIM) by using a high fill-factor Lissajous scanning micromirror and laser beam modulation. The LS-SIM was realized by a Lissajous scanned structured illumination module, relay optics, and a conventional fluorescent microscope. The micromirror comprises an inner mirror and an outer frame, which are scanned at pseudo-resonance with electrostatic actuation. The biaxial scanning frequencies are selected by the frequency selection rule for high fill-factor (> 80%) Lissajous scanning. Structured illumination (SI) was then realized by modulating the intensity of a laser beam at the least common multiple (LCM) of the scanning frequencies. A compact Lissajous scanned SI module containing a fiber-optic collimator and Lissajous micromirror has been fully packaged and coupled with relay optics and a fiber-based diode pumped solid state (DPSS) laser including acousto-optic-modulator (AOM). Various structured images were obtained by shifting the phase and orientation of the illumination patterns and finally mounted with a conventional fluorescent microscope. The LS-SIM has experimentally demonstrated high-resolution fluorescent microscopic imaging of reference targets and human lung cancer cell PC-9 cells. The LS-SIM exhibits the observable region in spatial frequency space over 2x, the line-edge sharpness over 1.5x, and the peak-to-valley (P-V) ratio over 2x, compared to widefield fluorescent microscopy. This method can provide a new route for advanced high-resolution fluorescent microscopic imaging.
High-speed range and velocity measurement using frequency scanning interferometry with adaptive delay lines [Invited]
Authors: Pallikarakis Christos A. , Huntley Jonathan M. , Ruiz Pablo D.
Published: September 2020

Range (i.e., absolute distance), displacement, and velocity of a moving target have been measured with a frequency scanning interferometer that incorporates a100,000scans−1vertical-cavity surface-emitting laser with 100 nm tuning range. An adaptive delay line in the reference beam, consisting of a chain of switchable exponentially growing optical delays, reduced modulation frequencies to sub-gigahertz levels. Range, displacement, and velocity were determined from the phase of the interference signal; fine alignment and linearization of the scans were achieved from the interferogram of an independent reference interferometer. Sub-nanometer displacement resolution, sub-100-nm range resolution, and velocity resolution of12µms−1have been demonstrated over a depth measurement range of 300 mm.
Reflection of whispering gallery modes propagating on a surface of an optical fiber from its cleave
Authors: Kudashkin Dmitry V. , Deriskiba Alexandr A. , Vatnik Ilya D. , Suchkov Sergey V. , Churkin Dmitry V.
Published: September 2020

We experimentally and numerically study the dynamics of whispering gallery modes slowly propagating within the cladding of an optical fiber near its end facet. We demonstrated that modes reflect from the fiber cleave. The reflection coefficient appears to reach 70% for the sample under study. Use of a facet provides a simple method to confine the axial propagation of the modes.
Modelo espacial de risco de incêndio intraurbano: fatores de população e carga de incêndio
Authors: França Carlos David Veiga , Melo Silas Nogueira de , De Castro Claudio Eduardo , Dos Santos Luiz Carlos Araújo
Published: September 2020

Embora os incêndios urbanos façam centenas de vítimas fatais e causem inúmeros prejuízos materiais a cada ano e em todo o mundo, poucos estudos se dedicam à formulação de um modelo simples de estimação do risco de incêndios urbanos. Nesse sentido, o objetivo do presente artigo é criar e implementar um modelo espacial de risco de incêndio intraurbano com apenas duas variáveis: população e valor de carga de incêndio. Uma área urbana brasileira de porte médio foi selecionada para análise empírica. Foram utilizados mapas e técnicas estatísticas como os índices de Moran, regressão linear e regressão de erro espacial. Os resultados evidenciam que as ocorrências de incêndio são concentradas no espaço intraurbano, bem como a variável população não foi estatisticamente significativa, mas a variável carga de incêndio foi positiva e significativa na associação com o risco de incêndio. As implicações dos resultados, em termos de políticas públicas, normas técnicas e protocolos são discutidas na conclusão.
Reporte de resultados negativos a Trichinella spp. por digestión artificial en cerdos domésticos del valle inferior del río Negro, Patagonia Argentina
Authors: WINTER Marina , RIBICICH Miriam Mabel , PERERA Nélida , COROMINAS María José , MANCINI Sergio , CARRIÓN-ANDRETICH Martín , ÁVILA Agustín , ABATE Sergio D.
Published: September 2020

Actualmente, el género Trichinella está constituido por 10 especies y 3 genotipos. La transmisión ocurre únicamente por ingestión de tejido muscular infectado. Entre los potenciales hospedadores se conforma un ciclo doméstico y un ciclo silvestre con posible retroalimentación constante entre ambos. Desde el año 2017 el funcionamiento del Matadero Social de San Javier, en el valle inferior del río Negro, permite a productores acceder a una faena segura que además brinde garantías al consumidor. El objetivo del presente trabajo fue evaluar la presencia de larvas L1 de Trichinella spp. en porcinos domésticos procedentes de criaderos de pequeña y mediana escala. Se analizaron por el método de digestión artificial 10 gramos de diafragma de cada porcino doméstico, conformando pooles de hasta 10 animales. En total 942 porcinos domésticos resultaron negativos a la presencia de larvas L1 de Trichinella spp. No obstante debe tenerse presente que sistemas de producción con las características de los que provienen los animales analizados, estarían potencialmente expuestos a la retroalimentación de Trichinella spp. desde la fauna silvestre. En este marco, resulta necesario garantizar el control veterinario en la faena de porcinos y presas de caza y sostener acciones de vigilancia, actualización y promoción en relación a la prevención de la triquinelosis.
Bearing Steel Technologies: 12th Volume, Progress in Bearing Steel Metallurgical Testing and Quality Assurance
Authors: Beswick John M.
Published: September 2020

Description

The latest volume in this historical series features a collection of 32 peer-reviewed papers highlighting the latest research and developments in rolling bearing steels and testing.

An excellent source of reference for the bearing steel technology industry, this new edition includes key research from global steel experts from nine countries. The book comprises articles from several of the presentations offered at the 12th International Symposium on Rolling Bearing Steels held in 2019.

Section topics of the symposium included
Influence of Material, Heat Treatment, and Microstructure in Resisting White Etching Crack Damage
Authors: Paladugu Mohanchand , Hyde R. Scott
Published: September 2020

In this study, steels that had undergone different heat treatments resulting in different microstructures were tested under rolling contact fatigue (RCF) and under specific test conditions known to cause white etching cracks (WECs). The test conditions included high slide-to-roll ratios and a lubricant known to promote WECs. It was observed that case-carburized AISI 3310 steel showed longer fatigue life than martensitically through-hardened 52100 steel with respect to a WEC damage mode. To understand how and why the case-carburized steel showed longer life, other material heat-treated combinations were tested and different material strengthening mechanisms were considered. The study examined carburized steel that had been heat treated differently and RCF tested. The 3310 steel was carburized at a lower carbon potential, and post carburize austenitization was done at a lower temperature so that lesser solute quantities would dissolve into the austenite phase prior to the quench step. The carburized steel samples with less solute dissolution showed higher hardness and more compressive stresses than the original carburized steel; however, they showed 75% shorter RCF life than the original carburized steel. These results suggest that solid solution strengthening is the prime contributor to fatigue resistance under WEC damage conditions. In addition, coarse microstructure morphologies obtained through high austenitization temperatures were shown to exhibit poor WEC damage resistance.
Improved Processing Techniques for Inclusion-Free Steel for Bearing and Mechanical Component Applications
Authors: DellaCorte Christopher
Published: September 2020

High-hardness, high-carbide powder metallurgy tool steels such as M62 enable the use of ball bearings at extremely high load and stress levels increasing the potential for rolling contact fatigue failure attributed to nonmetallic inclusions. Ever-cleaner steels are sought, but the results have been uneven, owing to the random nature of the occurrence of such material flaws. Careful melting processes and thorough ingot inspections prior to bearing manufacture are common approaches to avoid inclusions. Selecting only the cleanest portions of an ingot may result in bearings relatively free from material flaws. This approach is not always successful because detrimental flaws that exist deep within an ingot can pass inspections undetected, potentially causing subsequent failure. Recent efforts to commercialize an intermetallic material, 60NiTi, for rolling element bearings demonstrates a pathway to produce bearing steel that is free from unwanted ceramic particle inclusions. In this paper, the process used to make bearing-grade, inclusion-free NiTi alloys is described and applied to steelmaking. At its core, the NiTi process differs from steelmaking in one key aspect. NiTi alloys are made from elementally pure starting materials that are melted, blended, and processed in equipment that minimizes exposure to oxygen and other sources of contamination, ensuring an inclusion-free product. In contrast, the predominant method to make bearing steel is to employ a successive series of melt purification steps to reduce contamination levels below required thresholds. This paper describes the processes developed and applied to high-carbide tool steel, M62. The resulting material and microstructures are evaluated and compared to M62 prepared by conventional powder production and consolidation techniques. It is hoped that the application of materials manufacturing techniques used for fracture-sensitive ceramics and intermetallic materials such as NiTi can provide a pathway to nonmetallic inclusion-free steels for rolling element bearings and other failure critical applications.
High Performance Ferrium Steels for Aerospace Gearing and Bearing Applications
Authors: Taskin Kerem
Published: September 2020

Certain aerospace bearing components used in jet turbine engines suffer from standstill corrosion, and alloy development to date has not been able to address this issue due to the difficulty of balancing corrosion resistance and the high performance that is necessary for these applications. Integrated computational materials engineering (ICME) technologies are effective tools to rapidly design and develop novel alloys and achieve target property goals, and these tools have been successfully utilized in the development and deployment of high-performance aerospace steels. This paper begins with an overview of ICME tools and the methodology employed to utilize these tools in designing aerospace gear steels followed by a review of the design and development of a novel, high-performance, solution-nitridable bearing steel. The work describes the microstructural design concepts that were developed to achieve the targeted properties and presents the results of characterization and testing on a commercial-scale heat of the finalized alloy composition.
Design and Validation of a Modular Rolling Contact Fatigue/Rolling-Sliding Contact Fatigue Testing Machine
Authors: Novack Nicholas , Cryderman Robert L. , Rimroth Trace A.
Published: September 2020

A variety of testing machines have been developed to test rolling contact fatigue (RCF) and rolling–sliding contact fatigue (RSCF). Many of the RSCF machines have been designed to run at a fixed slide ratio using a geared driveline between the test specimen and the load wheel, which limits the versatility. As more complex stress states are being studied for applications in bearings and gears, the need has arisen for a modular testing machine that could allow the operator to vary both the Hertzian contact stress and the slide ratio to evaluate the effects of contact conditions and microstructure on RSCF. The solution was to build a machine that applies the contact load with a hydraulic cylinder and varies the slide ratio by driving the specimen and load roller through two independent motors, all of which the operator can control through a customizable LabVIEW interface. The equipment was designed around a specimen with a 25.4-mm diameter and a 152.4-mm length. This geometry is large enough to allow evaluation of commercial heat treatments and materials; additionally, it is capable of running two wear tracks on each specimen to reduce the number of specimens required. The hydraulic load application system is capable of developing Hertzian contact stress levels up to 3.2 GPa, with higher stresses possible by altering the load wheel geometry (e.g., crown radius). Damage in the test specimens is characterized postmortem through a variety of techniques. Some preliminary test results are presented to demonstrate the capabilities of the test equipment to evaluate the effects of steel microstructure on RSCF.