bluuebunny/crossref_metadata_2025 huggingface dataset:
Mycobacterium tuberculosis, antimicrobials, immunity, and lung–gut microbiota crosstalk: current updates and emerging advances
Authors: Osei Sekyere John , Maningi Nontuthuko E. , Fourie Petrus B.
Published: January 2020

Increasingly, gut microbiota distortions are being implicated in the pathogenesis of several infectious and noninfectious diseases. Specifically, in the absence of an eubiotic microbiota, mice are more prone to colonization and infection by Mycobacterium tuberculosis (Mtb). In this qualitative analysis, the following were observed: (1) antimicrobials cause long‐term gut microbiota perturbations; (2) Mtb causes limited and transient disturbances to the lung–gut microbiota; (3) pathogens (e.g., Helicobacter hepaticus) affect microbiota integrity and reduce resistance to Mtb; (4) dysbiosis depletes bacterial species regulating proper immune functioning, reducing resistance to Mtb; (5) dysregulated immune cells fail to express important pathogen‐recognition receptors (e.g., macrophage‐inducible C‐type lectin; MINCLE) and Mtb‐killing cytokines (e.g., IFN‐γ, TNF‐α, and IL‐17), with hampered phagocytic capability; (6) autophagy is central to the immune system's clearance of Mtb, control of inflammation, and immunity–microbiome balance; (7) microbiota‐produced short‐chain fatty acids, which are reduced by dysbiosis, affect immune cells and increase Mtb proliferation; (8) commensal species (e.g., Lactobacillus plantarum) and microbiota metabolites (e.g., indole propionic acid) reduce tuberculosis progression; and (9) fecal transplants mostly restored eubiosis, increased immune resistance to Mtb, restricted dissemination of Mtb, and reduced tuberculosis‐associated organ pathologies. Overuse of antimicrobials, as shown in mice, is a risk factor for reactivating latent or treated tuberculosis.
The Bright and Dark Sides of Customer Switching
Authors: Cai Dongling , Jiang Li
Published: January 2020

We investigate price and stock competition between two retailers selling to a market with uncertain size. Prior to knowing the actual market size, retailers choose stocking quantities before prices under prestocking but adopt the reverse sequence under prepricing. After the actual market size is realized, each customer chooses to purchase from a retailer to maximize utility. Each retailer satisfies its local demand up to availability. A customer with unmet demand at the local retailer may continue to visit the other retailer; we call this phenomenon customer switching. Absent customer switching, retailers always choose the same price and stocking quantity, and tailor decisions to suit market conditions. In the presence of customer switching, product value and market condition are crucial to whether and how retailers adapt their strategies. Retailers can adopt differential strategies, whereby the retailer that overprices the other stocks more as well, to profit from accommodating the spillover demand. Customer switching can also force the retailers to price low and stock less while both could benefit from pricing high and stocking more. These findings are robust with respect to the decision sequence. Compared to prepricing, prestocking weakens retailers’ incentive for strategic divergence but enables them to make higher profits when the market condition is sufficiently optimistic.
Uncertain Risk Assessment and Management: Case Studies of the Application of the Precautionary Principle in Portugal
Authors: Gonçalves Vasco Barroso
Published: January 2020

This study intends to clarify how the precautionary principle (PP) has been interpreted and applied by the courts in Portugal in the analysis of conflicts associated with uncertain and serious potential risks to human health and the environment. It also aims to contribute to the debate of when and how to apply precautionary measures. To this end, recent court cases in the areas of waste incineration, high‐voltage power lines, as well as dam and wind farm construction were considered. The degree of consistency in the courts’ decisions and their reasons in the different judicial bodies was analyzed with the support of a theoretical framework based on three attributes: the level of seriousness of potential hazards, level of evidence required, and the severity of precautionary actions taken. Different positions among courts were observed, with contradictory arguments in the same case or in similar cases. A greater propensity for favorable decisions in the acceptance of restraining orders was verified in the courts of lower instances, where human health could be threatened. However, the decisions of the Supreme Administrative Court, which were always unfavorable to the restraining orders, seem to reflect the priority given to national economic and political interests over local or regional environmental interests. They may also reflect the Supreme Court's reluctancy to apply the PP in the absence of a firm legally binding PP in national legislation. To address this situation, more explicit legal requirements and criteria for the analysis of uncertain risks and the weighting of interests by area of activity are needed.
Sparse Principal Component Analysis via Axis-Aligned Random Projections
Authors: Gataric Milana , Wang Tengyao , Samworth Richard J.
Published: January 2020

We introduce a new method for sparse principal component analysis, based on the aggregation of eigenvector information from carefully selected axis-aligned random projections of the sample covariance matrix. Unlike most alternative approaches, our algorithm is non-iterative, so it is not vulnerable to a bad choice of initialization. We provide theoretical guarantees under which our principal subspace estimator can attain the minimax optimal rate of convergence in polynomial time. In addition, our theory provides a more refined understanding of the statistical and computational trade-off in the problem of sparse principal component estimation, revealing a subtle interplay between the effective sample size and the number of random projections that are required to achieve the minimax optimal rate. Numerical studies provide further insight into the procedure and confirm its highly competitive finite sample performance.
Agenesia pulmonar
Authors: Oyola Mercedes , Gordillo Gisel , García Carlos A. , Torres David
Published: January 2020

La agenesia pulmonar es una alteración poco frecuente, con predominio en el sexo femenino y sin preferencia por la lateralidad. Reportamos el caso de un recién nacido masculino con diagnóstico prenatal de hernia diafragmática. Al nacer, se descartó esta patología y se hizo una impresión diagnóstica de malformación adenomatoide quística (malformación congénita de la vía aérea pulmonar) vs. agenesia pulmonar. El paciente falleció a los seis días de vida y la necropsia confirmó una agenesia pulmonar.
Enfermedad crónica en adultos mayores
Authors: Durán Adriana , Valderrama Laura , Uribe Ana Fernanda , González Angélica , Máximo Molina Juan
Published: January 2020

Metodología. Se seleccionó una muestra de 500 adultos mayores, entre los 60 y 96 años de edad. Se utilizó un cuestionario de factores psicosociales para el adulto mayor diseñado por Baca, González y Uribe.Resultados. Se observó que la hipertensión, la diabetes y la osteoporosis son las enfermedades más comunes en los adultos mayores, aunque el mayor porcentaje de esta población se encuentra sin ningún tipo de enfermedad. Asimismo, se observó que los adultos mayores casados y viudos presentaban más enfermedades en comparación con los que se encontraban solteros, separados o en unión libre.Conclusiones. La enfermedad crónica continúa siendo un problema en los adultos mayores y su presencia está relacionada, no sólo con la disminución de la funcionalidad del ser humano, sino también, con el control y la prevención de las enfermedades y la dificultadpara acceder a los sistemas de salud.
Deterioro cognitivo y envejecimiento: no hay evidencia de deterioro gradual de la memoria de trabajo, dependiente de la edad, en la rata Wistar
Authors: Bríñez José Arturo , Velásquez Silvio , Gómez Juan Daniel
Published: January 2020

La memoria de trabajo es un sistema neuro-conductual en el que participan la memoria a corto y a largo plazo, la orientación espacial, la planeación y la ejecución de tareas espaciales y lingüísticas, la adaptación social, las operaciones cognitivas complejas y los logros académicos, y que se ha utilizado para estudiar los cambios cognitivos asociados al envejecimiento.
De Gregor Mendel y la docencia sin licencia
Authors: Suárez Fernando , Ordóñez Adriana
Published: January 2020

Gregor Mendel, padre de la genética, fracasó en su intento por obtener la licenciatura que lo acreditara como profesor, pero su fracaso fue el origen de su posterior triunfo histórico. La fidelidad de Mendel hacia la defensa del preformismo fue la base de los experimentos en Pisum sativum. Su historia demuestra que la licencia no necesariamente certifica al verdadero maestro y que el buen maestro no requiere de licencia.
Linfoma nasal de células T asesinas naturales
Authors: Chavarriaga María Claudia , Moreno Ximena
Published: January 2020

El linfoma nasal de células T asesinas naturales, también conocido como granuloma letal de la línea media, es una entidad poco frecuente. Se trata de un linfoma extraganglionar de comportamiento agresivo que, usualmente, se origina en la cavidad nasal, prevalente en países orientales y en hombres en la tercera década de la vida. Su asociación con infección por el virus de Epstein-Barr actualmente está bien documentada. Su tratamiento es aún controvertido; la tendencia actual está a favor de la radioterapia.A continuación se presenta un caso de linfoma nasal de células T asesinas naturales y la revisión de la literatura, con el fin de proveer un mayor entendimiento de la enfermedad.
Evaluación del sistema de navegación magnética intracardiaca Niobe®, revisión sistemática de la literatura científica
Authors: Ruiz-Aragón Jesús , Molina-Linde Juan Máximo , Márquez-Pelaéz Sergio , Rodríguez-López Rocío
Published: January 2020

Introducción y objetivos. Los métodos actuales de ablación conllevan sistemas de navegación manual y ablación cardiaca, y presentan ciertas limitaciones. El objetivo de este trabajo ha sido evaluar la eficacia y seguridad de los nuevos sistemas de navegación magnética intracardiaca.Métodos. Se hizo una revisión sistemática en las bases MedLine, Embase, Cochrane Library, CRD, ECRI, Hayes y bases de datos de HTA. Como términos Mesh se usaron: “electrophisiologic techniques”, “magnetics”, “stereotaxic techniques”, “heart catheterization” y “catheter ablation”. Los criterios de inclusión fueron estudios con adultos y lesiones cardíacas. La intervención fue el sistema de navegación magnética intracardiaca Niobe®. Los resultados medidos fueron: tiempos totales de procedimiento, tiempo de fluoroscopia, tiempo de colocación del catéter, tiempo de mapeo y tiempo de ablación. La calidad se evaluó con los cuestionarios CASPe y STROBE.Resultados. Se localizaron 467 referencias y se incluyeron 14. Hubo dos ensayos clínicos de calidad moderada y 10 estudios observacionales con calidad baja a moderada. Los ensayos presentaron un tiempo total de procedimiento mediante la intervención, igual o superior al comparador (151 y 113 vs. 151 y 77,2 minutos), mientras que los tiempos de fluoroscopia fueron inferiores (17,8 y 10,6 vs. 27,1 y 15,0 minutos). En los estudios observacionales, el tiempo total de intervención osciló entre 59 y 243 minutos para los sistemas magnéticos, frente a 57 a 332 minutos empleando técnicas convencionales. Los trabajos reflejaron la técnica magnética como segura, sin efectos secundarios graves.Conclusiones. No se ha logrado obtener información de calidad para afirmar que los sistemas de navegación magnética intracardiaca superen con claridad a los sistemas convencionales.
Encefalitis de Bickerstaff, síndrome o espectro de Fisher Bickerstaff, reporte de dos casos
Authors: Pérez Juan Carlos , Mateus Sergio Andrés , Mosquera Juan Manuel
Published: January 2020

La encefalitis de Bickerstaff es una entidad infrecuente de origen posinfeccioso, de presentación grave y con un curso clínico generalmente benigno, cuya diferenciación con el síndrome de Fisher aún no es clara y su asociación con el síndrome de Guillain - Barré está ya establecida. Presentamos dos casos atendidos en el Hospital Universitario San Ignacio.
Resonancia magnética cerebral: secuencias básicas e interpretación
Authors: Rivera Diego Miguel , Puentes Sofía , Caballero Ligia
Published: January 2020

La resonancia magnética cerebral se ha establecido como una herramienta muy valiosa para el diagnóstico de enfermedades neurológicas, debido a su capacidad de proveer excelente detalle y caracterización de los tejidos.En este artículo se explican las bases físicas de la resonancia magnética y las diferentes secuencias usadas en el protocolo de imágenes cerebrales, con el objetivo de proporcionar al lector las herramientas básicas para comprender las imágenes del cerebro.
Profilaxis antibiótica en quemaduras
Authors: Nieto Luis Eduardo , Acosta Luis Manuel Alejandro , Bedoya Miguel Andrés , Tapias Vanesa
Published: January 2020

Introducción. Las quemaduras son un importante problema de salud, en especial en los países en vía de desarrollo, y presentan múltiples condiciones de morbilidad con altos porcentajes de mortalidad por procesos infecciosos.Desarrollo. Se hizo una búsqueda de la literatura médica disponible, con el objetivo de llegar a conclusiones acerca de la profilaxis antibiótica en el paciente con quemaduras.Conclusiones. Los antibióticos profilácticos reducen todas las causas de mortalidad en pacientes de la unidad de cuidado intensivo y en pacientes con quemaduras; administrados en las primeras dos semanas, reducen la mortalidad cerca a la mitad. Infortunadamente, la información disponible es insuficiente y estas medidas no se pueden generalizar. La profilaxis perioperatoria reduce la infección de las áreas quemadas, pero no la mortalidad, y los antibióticos tópicos aplicados en las lesiones disminuyen las tasas de infección y colonización bacteriana en algunos grupos etarios. Es necesario aportar nuevos y sólidos datos.
Effect of AlxGa1−xN buffer layer on the structural and electrical properties of AlGaN/GaN/AlxGa1−xN double heterojunction high electron mobility transistor structures
Authors: Nam Yongjun , Choi Uiho , Lee Kyeongjae , Jang Taehoon , Jung Donghyeop , Nam Okhyun
Published: January 2020

In this paper, the authors report the effect of the AlxGa1−xN buffer layer on the structural and electrical properties of an AlGaN/GaN/AlxGa1−xN double heterojunction high electron mobility transistor (HEMT). As the Al composition of the buffer layer increased, the two-dimensional electron gas (2DEG) confinement of the channel was shown to improve, which was confirmed by the simulation. The AlGaN buffer HEMT showed improved structural characteristics, such as the surface morphology, crystal quality, and interface roughness compared with the conventional HEMT with a C-doped GaN buffer. A slight decrease in 2DEG characteristics owing to the negative polarization charge was observed. However, in the breakdown voltage characteristics, comparable results were obtained as 652 V for the HEMT with C-doped GaN, 624 V for the HEMT with an Al0.044Ga0.956N buffer, and 642 V for the HEMT with an Al0.088Ga0.912N buffer, although the AlGaN buffers were not doped for semi-insulating.
Longer vowel duration correlates with greater tongue root advancement at vowel offset: Acoustic and articulatory data from Italian and Polish
Authors: Coretta Stefano
Published: January 2020

Voiced stops tend to be preceded by longer vowels and produced with a more advanced tongue root than voiceless stops. The duration of a vowel is affected by the voicing of the stop that follows, and in many languages vowels are longer when followed by voiced stops. Tongue root advancement is known to be an articulatory mechanism, which ensures the right pressure conditions for the maintenance of voicing during closure as dictated by the aerodynamic voicing constraint. In this paper, it is argued that vowel duration and tongue root advancement have a direct statistical relationship. Drawing from acoustic and ultrasound tongue imaging data from 17 speakers of Italian and Polish in total, it is proposed that the comparatively later closure onset of voiced stops is responsible for both greater root advancement and shorter closure durations of voiced stops. It is further shown that tongue root advancement is initiated during the vowel, and vowel duration and tongue root position at vowel offset are positively correlated so that longer vowel durations correspond to greater tongue root advancement.
A cluster-based direct source localization approach for large-aperture horizontal line arrays
Authors: Wang Lu , Yang Yixin , Liu Xionghou
Published: January 2020

In this paper, the problem of source localization using one-step direct position determination (DPD) approaches with large-aperture horizontal line arrays is considered. In practice, it may be difficult to keep the array configuration and overlarge inter-element spacing may cause the split beam problem when decentralized DPD approaches are applied. A cluster-based coherent MUSIC DPD approach is proposed to handle the unfavourable array configuration. The large-aperture array is divided into several small-aperture arrays, which form a coherent cluster to keep the largest covariance lag unchanged. Experimental results with the SWellEx96 data demonstrate the performance gain achieved by cluster-based coherent processing.
Geoacoustic inversion using ray-based blind deconvolution of shipping sources
Authors: Zhang Xuedong , Durofchalk Nicholas C. , Niu Haiqiang , Wu Lixin , Zhang Renhe , Sabra Karim G.
Published: January 2020

The ray-based blind deconvolution algorithm can provide an estimate of the channel impulse responses (CIRs) between a shipping source of opportunity and the elements of a receiving array by estimating the unknown phase of this random source through wideband beamforming along a well-resolved ray path. However, due to the shallow effective depth (typically <10 m) and low frequency content (typically less than a few kHz) associated with shipping sources, the interfering direct and surface arriving pair and subsequent bottom and surface-bottom arrival pair cannot always be resolved in the CIR arrival-time structure. Nevertheless, this study demonstrates that the bottom reflection loss can be inferred from the ratio of the magnitude spectra of these two arrival pairs if a frequency-dependent correction (which can be purely data based) is applied to correct for the dipole source effect. The feasibility of the proposed approach is demonstrated to invert for the geoacoustic parameters of a soft-layer covering the ocean floor using a nonlinear least-square algorithm.
Sml1 Inhibits the DNA Repair Activity of Rev1 in Saccharomyces cerevisiae during Oxidative Stress
Authors: Yao Rui , Zhou Pei , Wu Chengjin , Liu Liming , Wu Jing
Published: January 2020

Rev1 was critical for cell growth in
S. cerevisiae
, and the deletion of
REV1
caused a severe growth defect in cells exposed to oxidative stress (2 mM H
2
O
2
). Furthermore, we found that Sml1 physically interacted with Rev1 and inhibited Rev1 phosphorylation, thereby inhibiting Rev1 DNA antioxidant activity. These findings indicate that Sml1 could be a novel regulator for Rev1 in response to DNA damage by oxidative stress.
Human IgM Inhibits the Formation of Titan-Like Cells in Cryptococcus neoformans
Authors: Trevijano-Contador Nuria , Pianalto Kaila M. , Nichols Connie B. , Zaragoza Oscar , Alspaugh J. Andrew , Pirofski Liise-anne
Published: January 2020

Human studies have shown associations between cryptococcal meningitis and reduced IgM memory B cell levels, and studies in IgM- and/or B cell-deficient mice have demonstrated increased
Cryptococcus neoformans
dissemination from lungs to brain. Since immunoglobulins are part of the immune milieu that
C. neoformans
confronts in a human host, and its ability to form titan cells is an important virulence mechanism, we determined the effect of human immunoglobulins on
C. neoformans
titan cell formation
in vitro
.
Human Papillomavirus 58 E7 T20I/G63S Variant Isolated from an East Asian Population Possesses High Oncogenicity
Authors: Boon Siaw Shi , Xia Chichao , Lim Jin Yan , Chen Zigui , Law Priscilla T. Y. , Yeung Apple C. M. , Thomas Miranda , Banks Lawrence , Chan Paul K. S.
Published: January 2020

Epidemiological studies have revealed that a wild-type variant of HPV58 carrying an E7 variation, T20I/G63S (V1), is associated with a higher risk of cervical cancer. We previously reported that this increased oncogenicity could be the result of the virus’s greater ability to degrade pRB, thereby leading to an increased ability to grow in an anchorage-independent manner. In addition to this, this report further showed that this HPV variant induced activation of the AKT and K-Ras/ERK signaling pathways, thereby explaining its genuine oncogenicity in promoting cell proliferation, migration, invasion, and formation of tumors, all to a greater extent than the prototype HPV58 and other common variants.
Saccharomyces cerevisiae: First Steps to a Suitable Model System To Study the Function and Intracellular Transport of Human Kidney Anion Exchanger 1
Authors: Sarder Hasib A. M. , Li Xiaobing , Funaya Charlotta , Cordat Emmanuelle , Schmitt Manfred J. , Becker Björn
Published: January 2020

Distal renal tubular acidosis (dRTA) is a common kidney dysfunction characterized by impaired acid secretion via urine. Previous studies revealed that α-intercalated cells of dRTA patients express mutated forms of human kidney anion exchanger 1 (kAE1) which result in inefficient plasma membrane targeting or diminished expression levels of kAE1. However, the precise dRTA-causing processes are inadequately understood, and alternative model systems are helpful tools to address kAE1-related questions in a fast and inexpensive way. In contrast to a previous study, we successfully expressed full-length kAE1 in
Saccharomyces cerevisiae
. Using advanced microscopy techniques as well as different biochemical and functionality assays, plasma membrane localization and biological activity were confirmed for the heterologously expressed anion transporter. These findings represent first important steps to use the potential of yeast as a model organism for studying trafficking, activity, and degradation of kAE1 and its mutant variants in the future.
Simple, Mobile-based Artificial Intelligence Algorithm in the detection of Diabetic Retinopathy (SMART) study
Authors: Sosale Bhavana , Aravind Sosale Ramachandra , Murthy Hemanth , Narayana Srikanth , Sharma Usha , Gowda Sahana G V , Naveenam Muralidhar
Published: January 2020

Introduction

The aim of this study is to evaluate the performance of the offline smart phone-based Medios artificial intelligence (AI) algorithm in the diagnosis of diabetic retinopathy (DR) using non-mydriatic (NM) retinal images.

Methods

This cross-sectional study prospectively enrolled 922 individuals with diabetes mellitus. NM retinal images (disc and macula centered) from each eye were captured using the Remidio NM fundus-on-phone (FOP) camera. The images were run offline and the diagnosis of the AI was recorded (DR present or absent). The diagnosis of the AI was compared with the image diagnosis of five retina specialists (majority diagnosis considered as ground truth).

Results

Analysis included images from 900 individuals (252 had DR). For any DR, the sensitivity and specificity of the AI algorithm was found to be 83.3% (95% CI 80.9% to 85.7%) and 95.5% (95% CI 94.1% to 96.8%). The sensitivity and specificity of the AI algorithm in detecting referable DR (RDR) was 93% (95% CI 91.3% to 94.7%) and 92.5% (95% CI 90.8% to 94.2%).

Conclusion

The Medios AI has a high sensitivity and specificity in the detection of RDR using NM retinal images.
Complexity-Based Analysis of the Relation between Human Muscle Reaction and Walking Path
Authors: Kamal Shahul Mujib , Sim Sue , Tee Rui , Nathan Visvamba , Namazi Hamidreza
Published: January 2020

Legs are the contact point of humans during walking. In fact, leg muscles react when we walk in different conditions (such as different speeds and paths). In this research, we analyze how walking path affects leg muscles’ reaction. In fact, we investigate how the complexity of muscle reaction is related to the complexity of path of movement. For this purpose, we employ fractal theory. In the experiment, subjects walk on different paths that have different fractal dimensions and then we calculate the fractal dimension of Electromyography (EMG) signals obtained from both legs. The result of our analysis showed that the complexity of EMG signal increases with the increment of complexity of path of movement. The conducted statistical analysis also supported the result of analysis. The method of analysis used in this research can be further applied to find the relation between complexity of path of movement and other physiological signals of humans such as respiration and Electroencephalography (EEG) signal.
An Analysis on the Parametric Optimization of Electrochemical Honing Process
Authors: Diyaley Sunny , Chakraborthy Shankar
Published: January 2020

Electrochemical honing (ECH) is a nontraditional machining process hybridizing the conjoint benefits of electrochemical machining (ECM) and mechanical honing actions. In this process, maximum amount of material is removed through anodic dissolution, followed by mechanical abrasion. In present day manufacturing industries, it has found wide ranging applications, mainly in finishing of varieties of gears, due to its various advantages, like increased material removal rate, long tool life, burr-free operation, achievement of higher surface finish and dimensional accuracy, generation of no residual stress, reduced noise, less material damage, etc. In order to achieve maximum machining capability from this process, it is always recommended to set its various input parameters at their optimal operating levels. In this paper, four powerful metaheuristic algorithms, i.e. firefly algorithm, differential evolution (DE) algorithm, cuckoo search (CS) algorithm and teaching–learning-based optimization (TLBO) algorithm are applied for single as well as multi-objective optimization of pulsed-ECH (PECH) and ECH processes. It is observed that TLBO algorithm supersedes other techniques in optimizing the two ECH processes with respect to the value of the derived optimal solution, consistency of the solutions and computational speed.
Effect of Green Practices on Organizational Performance: An Evidence from Pakistan
Authors: Shuhui Yang , Yu Zhang , Rehman Khan Syed Abdul , Abbas Hina
Published: January 2020

This research examines the effects of green supply chain (SC) practices including recycling techniques, green logistics (G2), environmental protection trainings and programs, and green manufacturing. A data sample of 339 manufacturing firms was collected from the industrial area of Punjab, Pakistan. By using Structural Equation Modelling (SEM), the findings indicated that except GL, the remaining green practices (GP) have significant and positive association with the organizational performance. In addition, GL have insignificant effect on firms’ performance due to government non seriousness, no financial subsidies on green technologies, heavy import duties, scarcity of green technologies/vehicles in Pakistan and that most firms import green vehicles from European and Western countries which incur huge costs into SC system in terms of long lead time. This study will help the policymakers and SC managers to understand the problems and current situation of GSCM in the manufacturing firms of Pakistan. Further, we also discuss research limitations, areas for future research.
Interpolation of compact bilinear operators
Authors: Mastyło Mieczysław , Silva Eduardo B.
Published: January 2020

This paper is devoted to the study of the stability of the compactness property of bilinear operators acting on the products of interpolated Banach spaces. We prove one-sided compactness results for bilinear operators on products of Banach spaces generated by abstract methods of interpolation, in the sense of Aronszajn and Gagliardo. To get these results, we prove a key one-sided bilinear interpolation theorem on compactness for bilinear operators on couples satisfying an extra approximation property. We give applications to general cases, including Peetre’s method and the general real interpolation methods.
Relaxation methods for optimal control problems
Authors: Papageorgiou Nikolaos S. , Rădulescu Vicenţiu D. , Repovš Dušan D.
Published: January 2020

We consider a nonlinear optimal control problem with dynamics described by a differential inclusion involving a maximal monotone map [Formula: see text]. We do not assume that [Formula: see text], incorporating in this way systems with unilateral constraints in our framework. We present two relaxation methods. The first one is an outgrowth of the reduction method from the existence theory, while the second method uses Young measures. We show that the two relaxation methods are equivalent and admissible.
Understanding usability evaluation setup for VR products in industry
Authors: Karre Sai Anirudh , Mathur Neeraj , Reddy Y. Raghu
Published: January 2020

VR development practices have a diverse set of practices compared to traditional software development. Tasks like scene design, acoustic design, vergence manipulation, image depth, etc. are specific to VR apps and hence require evaluation processes that may be different from the traditional means. Usability Evaluation is one such process which is being executed in an unconventional way by Industrial Practitioners today. In this paper, the researchers detail a Systematic Literature Review of the Usability Evaluation Methods practised by Industrial researchers while building VR Products. The researchers found that VR Product teams follow unique methods to improve usability in their products. Further, the researchers consolidate these methods and provide insights into choosing the best to build a real-world VR Product based on the defined product constraints
Puzzle
Authors: Conitzer Vincent
Published: January 2020

Please send solutions to the author by e-mail, with the title of this puzzle in the subject header. By agreement with the editors, the best solution will be published in the next issue of SIGecom Exchanges, provided that that solution is of sufficiently high quality. Quality is judged by the author, taking into account at least soundness, completeness, and clarity of exposition. A solution may be published even if it does not solve all cases.
Corrective Intra-Articular Osteotomy Using a 3D-Printed Model and Induced Membrane Technique for AO/OTA C3 Distal Femur Fracture with Articular Malunion and Metaphyseal Nonunion
Authors: Saka Natsumi , Watanabe Yoshinobu , Sasaki Gen , Kawano Hirotaka
Published: January 2020

Comminuted distal femur fracture is a challenging injury, and care must be taken to reduce the articular fragment and acquire the sufficient stability for the metaphyseal comminution. We report the case of a AO/OTA C3-type distal femur fracture with articular malunion and metaphyseal nonunion. Articular malunion was treated with corrective osteotomy using a 3D-printed model for planning, and metaphyseal nonunion was treated with an induced membrane technique. Conclusion. Two major complications in the comminuted periarticular fracture can be addressed by an osteotomy and induced membrane technique. A 3D-printed model is a useful tool to evaluate the morphology of the malunited articular surface.
The Kinetic Model of the Peel Brittleness of Stored Cucumis Melons Based on Visible/Near-Infrared Spectroscopy
Authors: Xu Defang , Zhao Huamin , Zhang Shujuan , Li Chengji , Zhao Fei
Published: January 2020

A kinetic model based on visible/near-infrared spectroscopy of the peel brittleness of “Xintian-125” Cucumis melons, the research object, stored under room temperature, was established in order to realize real-time monitoring of the peel brittleness of Cucumis melons and for prediction of storage time. The NIR and peel brittleness of melons stored for 1, 4, and 7 days were collected and measured. SG was confirmed to be the best pretreatment by comparing the PLS models established with 4 pretreatment methods, and the differences of the prediction set determination coefficient and root-mean-square were 0.818 and 23.755, respectively. CARS and SPA were adopted to extract the feature wavelengths and establish the peel brittleness of PLS prediction model. The model’s prediction accuracy was 0.919, and the prediction root-mean-square was 25.413, indicating that NIR is able to realize the prediction of the peel brittleness of Cucumis melons. As a result, a NIR-based peel brittleness kinetic model was created. The

P

value of the regression model was less than 0.001, and the model’s correlation coefficient was 0.8503, showing that the model is of extreme significance and high precision. The zero-order reaction equation was overfitted according to the variation tendency of the average peel brittleness of stored melons. The model’s correlation coefficient was 0.981, the standard error was 4.624, and the linear relation between the stored period and NIR was established based on it. The research proves that the NIR-based technology is able to realize quick and loss-free inspection of melons’ peel brittleness and prediction of the stored period.
Assessment of Risk Factors for Fractures in Patients with Type 2 Diabetes over 60 Years Old: A Cross-Sectional Study from Northeast China
Authors: Guo Yan , Wang Yingfang , Chen Feng , Wang Jiabei , Wang Difei
Published: January 2020

Aims. Previous evidence has demonstrated an increased fracture risk among the population with type 2 diabetes mellitus (T2DM). This study investigated the prevalence of bone fractures in elderly subjects (with and without type 2 diabetes) and identified any fracture risk factors, especially the risk factors for common known fractures in particular diabetic populations. Methods. This cross-sectional study was conducted with community-dwelling people over 60 years old in nine communities from the city of Shenyang, which is the capital of Northeast China’s Liaoning Province. A total of 3430 elderly adults (2201 females, mean±standard deviation age 68.16±6.1 years; 1229 males, 69.16±6.7 years) were included. Our study measured the heel bone mineral density (BMD) and used the timed “up and go” (TUG) test and other indicators. In addition, we performed logistic regression analysis to explore the risk factors for fractures in the general population and the diabetic population and to analyze the differences. Results. The results revealed that a total of 201 elderly persons (5.8%), with an average age of 70.05±6.54 years, suffered from a history of fragility fractures, which affected more females (74.6%) than males (p=0.001). The prevalence of fractures in the T2DM population was 7.3%, which was much higher than the 5.2% in non-T2DM population (p<0.05). In the non-T2DM population, the BMD was lower and the TUG time was longer in the fracture group than in the nonfracture group (p<0.001). However, in the T2DM population, the BMD and TUG values were similar between the fracture group and the nonfracture group (p>0.05). Logistic regression analysis showed that the female sex (OR 1.835), TUG time>10.2 s (OR 1.602), and T‐score≤−2.5 (OR 1.750) were independent risk factors for fragility fractures in the non-T2DM population, but they were not risk factors in the T2DM population. Conclusions. This study found that low BMD and slow TUG time were independent risk factors for fractures in non-T2DM patients, while no associations were found in the T2DM population. Patients with T2DM have a higher risk for fractures even when they have sufficient BMD and a short TUG time. TUG and BMD underestimated the risk for fractures in the T2DM population.
Automatic Segmentation and Measurement on Knee Computerized Tomography Images for Patellar Dislocation Diagnosis
Authors: Sun Limin , Kong Qi , Huang Yan , Yang Jiushan , Wang Shaoshan , Zou Ruiqi , Yin Yilong , Peng Jingliang
Published: January 2020

Traditionally, for diagnosing patellar dislocation, clinicians make manual geometric measurements on computerized tomography (CT) images taken in the knee area, which is often complex and error-prone. Therefore, we develop a prototype CAD system for automatic measurement and diagnosis. We firstly segment the patella and the femur regions on the CT images and then measure two geometric quantities, patellar tilt angle (PTA), and patellar lateral shift (PLS) automatically on the segmentation results, which are finally used to assist in diagnoses. The proposed quantities are proved valid and the proposed algorithms are proved effective by experiments.
Metabolomics of the Protective Effect of Ampelopsis grossedentata and Its Major Active Compound Dihydromyricetin on the Liver of High‐Fat Diet Hamster
Authors: Fan Lanlan , Qu Xiaosheng , Yi Tao , Peng Yong , Jiang Manjing , Miao Jianhua , Xiao Peigen
Published: January 2020

The flavonoid dihydromyricetin (DMY) is the main component of Ampelopsis grossedentata (Hand‐Mazz) W. T. Wang (AG), a daily beverage and folk medicine used in Southern China to treat jaundice hepatitis, cold fever, and sore throat. Recently, DMY and AG were shown to have a beneficial effect on lipid metabolism disorder. However, the mechanisms of how DMY and AG protect the liver during lipid metabolism disorder remain unclear. In this study, we first analyzed the chemical compounds of AG by HPLC‐DAD‐ESI‐IT‐TOF‐MSn. Of the 31 compounds detected, 29 were identified based on previous results. Then, the effects of DMY and AG on high‐fat diet hamster livers were studied and the metabolite levels and metabolic pathway activity of the liver were explored by 1H NMR metabolomics. Compared to the high‐fat diet group, supplementation of AG and DMY attenuated the high‐fat‐induced increase in body weight, liver lipid deposition, serum triglycerides and total cholesterol levels, and normalized endogenous metabolite concentrations. PCA and PLS‐DA score plots demonstrated that while the metabolic profiles of hamsters fed a high‐fat diet supplemented with DMY or AG were both far from those of hamsters fed a normal diet or a high‐fat diet alone, they were similar to each other. Our data suggest that the underlying mechanism of the protective effect of DMY and AG might be related to an attenuation of the deleterious effect of high‐fat diet‐induced hyperlipidemia on multiple metabolic pathways including amino acid metabolism, ketone body metabolism, energy metabolism, tricarboxylic acid cycle, and enhanced fatty acid oxidation.
Compact Local Structure-Preserving Algorithms for the Nonlinear Schrödinger Equation with Wave Operator
Authors: Huang Langyang , Tian Zhaowei , Cai Yaoxiong
Published: January 2020

Combining the compact method with the structure-preserving algorithm, we propose a compact local energy-preserving scheme and a compact local momentum-preserving scheme for the nonlinear Schrödinger equation with wave operator (NSEW). The convergence rates of both schemes are Oh4+τ2. The discrete local conservative properties of the presented schemes are derived theoretically. Numerical experiments are carried out to demonstrate the convergence order and local conservation laws of the developed algorithms.
Muscle Synergy and Musculoskeletal Model-Based Continuous Multi-Dimensional Estimation of Wrist and Hand Motions
Authors: Kim Yeongdae , Stapornchaisit Sorawit , Kambara Hiroyuki , Yoshimura Natsue , Koike Yasuharu
Published: January 2020

In this study, seven-channel electromyography signal-based two-dimensional wrist joint movement estimation with and without handgrip motions was carried out. Electromyography signals were analyzed using the synergy-based linear regression model and musculoskeletal model; they were subsequently compared with respect to single and combined wrist joint movements and handgrip. Using each one of wrist motion and grip trial as a training set, the synergy-based linear regression model exhibited a statistically significant performance with 0.7891 ± 0.0844 Pearson correlation coefficient (r) value in two-dimensional wrist motion estimation compared with 0.7608 ±  0.1037 r value of the musculoskeletal model. Estimates on the grip force produced 0.8463 ± 0.0503 r value with 0.2559 ± 0.1397 normalized root-mean-square error of the wrist motion range. This continuous wrist and handgrip estimation can be considered when electromyography-based multi-dimensional input signals in the prosthesis, virtual interface, and rehabilitation are needed.
Farrerol Directly Targets GSK-3β to Activate Nrf2-ARE Pathway and Protect EA.hy926 Cells against Oxidative Stress-Induced Injuries
Authors: Yan Chaoqun , Zhang Xiaoyan , Miao Junqiu , Yuan Hongxia , Liu Enli , Liang Taigang , Li Qingshan
Published: January 2020

Oxidative stress-mediated endothelial injury is considered to be involved in the pathogenesis of various cardiovascular diseases. Farrerol, a typical natural flavanone from the medicinal plant Rhododendron dauricum L., has been reported to show protective effects against oxidative stress-induced endothelial injuries in our previous study. However, its action molecular mechanisms and targets are still unclear. In the present study, we determined whether farrerol can interact with glycogen synthase kinase 3β- (GSK-3β-) nuclear factor erythroid 2-related factor 2- (Nrf2-) antioxidant response element (ARE) signaling, which is critical in defense against oxidative stress. Our results demonstrated that farrerol could specifically target Nrf2 negative regulator GSK-3β and inhibit its kinase activity. Mechanistic studies proved that farrerol could induce an inhibitory phosphorylation of GSK-3β at Ser9 without affecting the expression level of total GSK-3β protein and promote the nuclear translocation of Nrf2 as well as the mRNA and protein expression of its downstream target genes heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) in EA.hy926 cells. Further studies performed with GSK-3β siRNA and specific inhibitor lithium chloride (LiCl) confirmed that GSK-3β inhibition was involved in farrerol-mediated endothelial protection and Nrf2 signaling activation. Moreover, molecular docking and molecular dynamics studies revealed that farrerol could bind to the ATP pocket of GSK-3β, which is consistent with the ATP-competitive kinetic behavior. Collectively, our results firstly demonstrate that farrerol could attenuate endothelial oxidative stress by specifically targeting GSK-3β and further activating the Nrf2-ARE signaling pathway.
An Integral Equation Formalism for Integrating a Nonlinear Initial-Boundary Value Problem for a Boussinesq Equation
Authors: Jang T. S.
Published: January 2020

In this paper, a new nonlinear initial-boundary value problem for a Boussinesq equation is formulated. And a coupled system of nonlinear integral equations, equivalent to the new initial-boundary value problem, is constructed for integrating the initial-boundary value problem, but which is inherently different from other conventional formulations for integral equations. For the numerical solutions, successive approximations are applied, which leads to a functional iterative formula. A propagating solitary wave is simulated via iterating the formula, which is in good agreement with the known exact solution.
Kernel-Based Aggregating Learning System for Online Portfolio Optimization
Authors: Wang Xin , Sun Tao , Liu Zhi
Published: January 2020

Recently, various machine learning techniques have been applied to solve online portfolio optimization (OLPO) problems. These approaches typically explore aggressive strategies to gain excess returns due to the existence of irrational phenomena in financial markets. However, existing aggressive OLPO strategies rarely consider the downside risk and lack effective trend representation, which leads to poor prediction performance and large investment losses in certain market environments. Besides, prediction with a single model is often unstable and sensitive to the noises and outliers, and the subsequent selection of optimal parameters also become obstacles to accurate estimation. To overcome these drawbacks, this paper proposes a novel kernel-based aggregating learning (KAL) system for OLPO. It includes a two-step price prediction scheme to improve the accuracy and robustness of the estimation. Specifically, a component price estimator is built by exploiting additional indicator information and the nonstationary nature of financial time series, and then an aggregating learning method is presented to combine multiple component estimators following different principles. Next, this paper conducts an enhanced tracking system by introducing a kernel-based increasing factor to maximize the future wealth of next period. At last, an online learning algorithm is designed to solve the system objective, which is suitable for large-scale and time-limited situations. Experimental results on several benchmark datasets from diverse real markets show that KAL outperforms other state-of-the-art systems in cumulative wealth and some risk-adjusted metrics. Meanwhile, it can withstand certain transaction costs.
Cyclic Testing of Bolt‐Weld Joints Reinforced by Sleeves Connecting Circular CFST Columns to Steel Beams
Authors: Bu Yonghong , Yang Qi , Wang Yihong , Zhang Dongfang
Published: January 2020

This study examined the design of joints reinforced by sleeves for connecting circular concrete‐filled steel tube columns to steel beams. Six half‐scale specimens, including four bolt‐weld joints reinforced by sleeves and two bolt and stiffened end‐plate joints, were designed and tested under cyclic loading to evaluate the seismic behavior of these joints. The joint construction and beam‐column stiffness ratio were taken as the main parameters in the tests. The seismic behaviors, including the failure modes, hysteretic curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The experimental results showed that no obvious bolt loosening, fracture, or widespread weld cracking appeared in the joints reinforced by sleeves. Furthermore, the joint strength and stiffness were markedly increased by the sleeves in the joint core area. Overall, most specimens exhibited full hysteresis loops and excellent ductilities, the equivalent viscous damping coefficients were 0.263∼0.532, and the ductility coefficients were 1.77∼3.42. The interstory drift ratios satisfied the requirements specified by technical regulations. The connections of these types exhibit favorable energy dissipations and can be effectively utilized for building construction in earthquake‐prone areas. This research should contribute to the future engineering applications of concrete‐filled steel tube to composite structure.