bluuebunny/crossref_metadata_2025 huggingface dataset:
Medroxyprogesterone Reverses Tolerable Dose Metformin-Induced Inhibition of Invasion via Matrix Metallopeptidase-9 and Transforming Growth Factor-β1 in KLE Endometrial Cancer Cells
Authors: Suh Dong Hoon , Lee Sunray , Park Hyun-Sook , Park Noh Hyun
Published: November 2020

This study was performed to evaluate the anticancer effects of tolerable doses of metformin with or without medroxyprogesterone (MPA) in endometrial cancer cells. Cell viability, cell invasion, and levels of matrix metallopeptidase (MMP) and transforming growth factor (TGF)-β1 were analyzed using three human endometrial adenocarcinoma cell lines (Ishikawa, KLE, and uterine serous papillary cancer (USPC)) after treatment with different dose combinations of MPA and metformin. Combining metformin (0, 100, 1000 µM) and 10 µM MPA induced significantly decreased cell viability in a time- and dose-dependent manner in Ishikawa cells, but not in KLE and USPC cells. In KLE cells, metformin treatment alone significantly inhibited cell invasion in a dose-dependent manner. The inhibitory effect of metformin was reversed when 10 µM MPA was combined, which was significantly inhibited again after treatment of MMP-2/9 inhibitor and/or TGF-β inhibitor. Changes of MMP-9 and TGF-β1 according to combinations of MPA and metformin were similar to those of invasion in KLE cells. In conclusion, the anticancer effects of tolerable doses of metformin varied according to cell type and combinations with MPA. Anti-invasive effect of metformin in KLE cells was completely reversed by the addition of MPA; this might be associated with MMP-9 and TGF-β1.
Association of UBE3C Variants with Reduced Kidney Function in Patients with Diabetic Kidney Disease
Authors: Chen Ying-Chun , Wu Mei-Yi , Yu Zhi-Lei , Chou Wan-Hsuan , Lai Yi-Ting , Kao Chih-Chin , Faridah Imaniar Noor , Wu Mai-Szu , Chang Wei-Chiao
Published: November 2020

Diabetic kidney disease (DKD) is the leading cause of morbidity and mortality in patients with diabetes mellitus (DM) and the most common variant of end-stage renal disease (ESRD) globally. The economic burden of ESRD treatment with dialysis is substantial. The incidence and prevalence of ESRD in Taiwan remain the highest worldwide. Therefore, identifying genetic factors affecting kidney function would have valuable clinical implications. We performed microarray experiments and identified that ubiquitin protein ligase E3C (UBE3C) is differentially expressed in two DKD patient groups with extreme (low and high) urine protein-to-creatinine ratios. A follow-up genotyping study was performed in a larger group to investigate any specific variants of UBE3C associated with DKD. A total of 263 patients were included in the study, comprising 172 patients with DKD and 91 control subjects (patients with DM without chronic kidney disease (CKD)). Two UBE3C variants (rs3802129(AA) and rs7807(CC)) were determined to be associated with reduced kidney function. The haplotype analysis revealed that rs3802129/rs3815217 (block 1) with A/G haplotype and rs8101/rs7807 (block 2) with T/C haplotype were associated with higher risks of CKD phenotypes. These findings suggest a clinical role of UBE3C variants in DKD risk.
Discrete-Event Simulation Thermal Model for Extrusion-Based Additive Manufacturing of PLA and ABS
Authors: Bhandari Sunil , Lopez-Anido Roberto A.
Published: November 2020

The material properties of thermoplastic polymer parts manufactured by the extrusion-based additive manufacturing process are highly dependent on the thermal history. Different numerical models have been proposed to simulate the thermal history of a 3D-printed part. However, they are limited due to limited geometric applicability; low accuracy; or high computational demand. Can the time–temperature history of a 3D-printed part be simulated by a computationally less demanding, fast numerical model without losing accuracy? This paper describes the numerical implementation of a simplified discrete-event simulation model that offers accuracy comparable to a finite element model but is faster by two orders of magnitude. Two polymer systems with distinct thermal properties were selected to highlight differences in the simulation of the orthotropic response and the temperature-dependent material properties. The time–temperature histories from the numerical model were compared to the time–temperature histories from a conventional finite element model and were found to match closely. The proposed highly parallel numerical model was approximately 300–500 times faster in simulating thermal history compared to the conventional finite element model. The model would enable designers to compare the effects of several printing parameters for specific 3D-printed parts and select the most suitable parameters for the part.
Physicochemical Properties and Cell Viability of Shrimp Chitosan Films as Affected by Film Casting Solvents. I-Potential Use as Wound Dressing
Authors: Eulálio Hugo Yves C. , Vieira Mariana , Fideles Thiago B. , Tomás Helena , Silva Suédina M. L. , Peniche Carlos A. , Fook Marcus Vinícius L.
Published: November 2020

Chitosan solubility in aqueous organic acids has been widely investigated. However, most of the previous works have been done with plasticized chitosan films and using acetic acid as the film casting solvent. In addition, the properties of these films varied among studies, since they are influenced by different factors such as the chitin source used to produce chitosan, the processing variables involved in the conversion of chitin into chitosan, chitosan properties, types of acids used to dissolve chitosan, types and amounts of plasticizers and the film preparation method. Therefore, this work aimed to prepare chitosan films by the solvent casting method, using chitosan derived from Litopenaeus vannamei shrimp shell waste, and five different organic acids (acetic, lactic, maleic, tartaric, and citric acids) without plasticizer, in order to evaluate the effect of organic acid type and chitosan source on physicochemical properties, degradation and cytotoxicity of these chitosan films. The goal was to select the best suited casting solvent to develop wound dressing from shrimp chitosan films. Shrimp chitosan films were analyzed in terms of their qualitative assessment, thickness, water vapor permeability (WVP), water vapor transmission rate (WVTR), wettability, tensile properties, degradation in phosphate buffered saline (PBS) and cytotoxicity towards human fibroblasts using the resazurin reduction method. Regardless of the acid type employed in film preparation, all films were transparent and slightly yellowish, presented homogeneous surfaces, and the thickness was compatible with the epidermis thickness. However, only the ones prepared with maleic acid presented adequate characteristics of WVP, WVTR, wettability, degradability, cytotoxicity and good tensile properties for future application as a wound dressing material. The findings of this study contributed not only to select the best suited casting solvent to develop chitosan films for wound dressing but also to normalize a solubilization protocol for chitosan, derived from Litopenaeus vannamei shrimp shell waste, which can be used in the pharmaceutical industry.
Development of the Structure of Cemented Carbides during Their Processing by SLM and HIP
Authors: Bricín David , Ackermann Michal , Jansa Zdeněk , Kubátová Dana , Kříž Antonín , Špirit Zbyněk , Šafka Jiří
Published: November 2020

The study focuses on microstructural evolution in a WC-Co powder mixture during Selective Laser Melting (SLM) and hot isostatic pressing (HIP) processing. This powder mixture contained a 13 ± 0.6% weight fraction of Co binder and WC particles of mean size of 3.0 ± 1.9 μm. SLM of the mixture produced samples of various densities, depending on the volumetric energy density (VED) applied. High VED levels led to densities of up to 88%. The aspects affected by changes in VED included the pore density as well as the resulting types of phases and the size of WC phase particles. At high VED, the material began to develop cracks due to embrittlement. This had multiple causes: coarsening of α-phase (WC), evaporation of β-phase (Co binder), and precipitation of η-phase. At low VED levels, pores formed, typically of nonsymmetric shapes, with sizes larger than 500 μm. Subsequent HIP processing led to an increased density, up to 96% of solid material. Contributions to this increased density were provided by structure transformations, namely, coarsening of α-phase by up to 1300% when compared to the powder grain size, and formation of η-phase. The results provided a basis for steering further research to explore to a greater depth the SLM and HIP processing of selected WC-Co powder mixtures with as yet unused ranges of process parameters.
In-Depth Comparison of an Industrially Extruded Powder and Ingot Al Alloys
Authors: Bombač David , Cvahte Peter , Balog Martin , Kugler Goran , Terčelj Milan
Published: November 2020

An industrial press was used to consolidate compacted aluminum powder with a nominal diameter in the range of 1 µm. Direct and indirect hot-extrusion processes were used, and suitable process parameters were determined from heating conditions, ram speeds and billet temperatures. For comparison, a direct-extrusion press for hot extrusion of a conventional aluminum alloy AA 1050 was used. The extruded Al powder showed better mechanical properties and showed a thermal stability of the mechanical properties after annealing treatments. To increase the theoretical density of the directly extruded Al powder, single-hit hot-compression tests were carried out. Activation energies for hot forming were calculated from hot-compression tests carried out in the temperature range 300–580 °C, at different strain rates. Processing maps were used to demonstrate safe hot-working conditions, to obtain an optimal microstructure after hot forming of extruded Al powder.
True and Illusory Benefits of Modeling: Comment on “Genome-Scale Metabolic Network Reconstruction and In Silico Analysis of Hexanoic Acid Producing Megasphaera elsdenii. Microorganisms 2020, 8, 539”
Authors: Panikov Nicolai S.
Published: November 2020

Lee et al [...]
Tectono-Metamorphic Evolution of Serpentinites from Lanzo Valleys Subduction Complex (Piemonte—Sesia-Lanzo Zone Boundary, Western Italian Alps)
Authors: Assanelli Matteo , Luoni Pietro , Rebay Gisella , Roda Manuel , Spalla Maria Iole
Published: November 2020

In the upper Tesso Valley the folded contact between Piemonte Zone ophiolites and Sesia-Lanzo Zone continental crust is exposed. Here serpentinites, metabasites, calcschists and fine-grained gneisses are deformed by four ductile superposed groups of structures, associated with different mineral assemblages. Different serpentinite lithologies have been recognized and studied in detail. Mylonitic D2 structures are pervasive and mineral assemblages point to re-equilibration at T of 450 ± 50 ∘C and P of 0.8 ± 0.3 GPa, under blueschist/epidote amphibolite-facies conditions. Pre-D2 structures and mineral assemblages are relics within S2 and indicate a re-equilibration under eclogite-facies conditions, at T of 570 ± 50 ∘C and P > 1.8 GPa. Post-D2 occurs under greenschist-facies conditions. Numerical modeling of a subduction zone allows exploration of the geodynamic context in which such PT path could have developed, and to make hypotheses about the possible timing of such a scenario, in agreement with the timing generally proposed for the Alpine subduction and collision. Model predictions indicate that pre-D2 mineral assemblages may have developed during Paleocene at 60–90 km depth and 115–145 km from the trench, or, alternatively, during lower Eocene at ca. 70–90 km depth, and 135–160 km from the trench.
Molecular Dynamics Studies of Poly(Lactic Acid) Nanoparticles and Their Interactions with Vitamin E and TLR Agonists Pam1CSK4 and Pam3CSK4
Authors: Megy Simon , Aguero Stephanie , Da Costa David , Lamrayah Myriam , Berthet Morgane , Primard Charlotte , Verrier Bernard , Terreux Raphael
Published: November 2020

Poly(lactic acid) (PLA) nanoparticles (NPs) are widely investigated due to their bioresorbable, biocompatible and low immunogen properties. Interestingly, many recent studies show that they can be efficiently used as drug delivery systems or as adjuvants to enhance vaccine efficacy. Our work focuses on the molecular mechanisms involved during the nanoprecipitation of PLA NPs from concentrated solutions of lactic acid polymeric chains, and their specific interactions with biologically relevant molecules. In this study, we evaluated the ability of a PLA-based nanoparticle drug carrier to vectorize either vitamin E or the Toll-like receptor (TLR) agonists Pam1CSK4 and Pam3CSK4, which are potent activators of the proinflammatory transcription factor NF-κB. We used dissipative particle dynamics (DPD) to simulate large systems mimicking the nanoprecipitation process for a complete NP. Our results evidenced that after the NP formation, Pam1CSK4 and Pam3CSK4 molecules end up located on the surface of the particle, interacting with the PLA chains via their fatty acid chains, whereas vitamin E molecules are buried deeper in the core of the particle. Our results allow for a better understanding of the molecular mechanisms responsible for the formation of the PLA NPs and their interactions with biological molecules located either on their surfaces or encapsulated within them. This work should allow for a rapid development of better biodegradable and safe vectorization systems with new drugs in the near future.
The Effects of Non-Nutritive Artificial Sweeteners, Aspartame and Sucralose, on the Gut Microbiome in Healthy Adults: Secondary Outcomes of a Randomized Double-Blinded Crossover Clinical Trial
Authors: Ahmad Samar Y. , Friel James , Mackay Dylan
Published: November 2020

Non-nutritive artificial sweeteners (NNSs) may have the ability to change the gut microbiota, which could potentially alter glucose metabolism. This study aimed to determine the effect of sucralose and aspartame consumption on gut microbiota composition using realistic doses of NNSs. Seventeen healthy participants between the ages of 18 and 45 years who had a body mass index (BMI) of 20–25 were selected. They undertook two 14-day treatment periods separated by a four-week washout period. The sweeteners consumed by each participant consisted of a standardized dose of 14% (0.425 g) of the acceptable daily intake (ADI) for aspartame and 20% (0.136 g) of the ADI for sucralose. Faecal samples collected before and after treatments were analysed for microbiome and short-chain fatty acids (SCFAs). There were no differences in the median relative proportions of the most abundant bacterial taxa (family and genus) before and after treatments with both NNSs. The microbiota community structure also did not show any obvious differences. There were no differences in faecal SCFAs following the consumption of the NNSs. These findings suggest that daily repeated consumption of pure aspartame or sucralose in doses reflective of typical high consumption have minimal effect on gut microbiota composition or SCFA production.
Development of a High-throughput Agar Colony Formation Assay to Identify Drug Candidates against Medulloblastoma
Authors: Sedeeq Mohammed , Maklad Ahmed , Gueven Nuri , Azimi Iman
Published: November 2020

Medulloblastoma (MB) is the most common malignant childhood brain cancer. High-risk MB tumours have a high incidence of metastasis and result in poor patient survival. Drug screens, commonly used to identify potential novel therapeutic agents against MB, focus on 2D cell proliferation and viability assays given that these assays are easily adaptable to high-throughput regimes. However, 2D models fail to address invasive characteristics that are crucial to MB metastasis and are thus not representative of tumour growth in vivo. In this study, we developed a 3D 384-well agar colony formation assay using MB cells of molecular subgroup 3 that is associated with the highest level of metastasis. Two fluorescence substrates, resazurin and glycyl-phenylalanyl-aminofluorocoumarin (GF-AFC) that measure cell viability via distinct mechanisms were used to assess the growth of MB cells in the agar matrix. The assay was optimised for seeding density, growth period, substrate incubation time and homogeneity of the fluorescent signals within individual wells. Our data demonstrate the feasibility to multiplex the two fluorescent substrates without detectable signal interference. This assay was validated by assessing the concentration-dependent effect of two commonly used chemotherapeutic agents clinically used for MB treatment, vincristine and lomustine. Subsequently, a panel of plasma membrane calcium channel modulators was screened for their effect on the 3D growth of D341 MB cells, which identified modulators of T-type voltage gated and ORAI calcium channels as selective growth modulators. Overall, this 3D assay provides a reproducible, time and cost-effective assay for high-throughput screening to identify potential drugs against MB.
Boosting the Brain Delivery of Atazanavir through Nanostructured Lipid Carrier-Based Approach for Mitigating NeuroAIDS
Authors: Khan Saif Ahmad , Rehman Saleha , Nabi Bushra , Iqubal Ashif , Nehal Nida , Fahmy Usama A. , Kotta Sabna , Baboota Sanjula , Md Shadab , Ali Javed
Published: November 2020

Atazanavir (ATZ) presents poor brain availability when administered orally, which poses a major hurdle in its use as an effective therapy for the management of NeuroAIDS. The utilization of nanostructured lipid carriers (NLCs) in conjunction with the premeditated use of excipients can be a potential approach for overcoming the limited ATZ brain delivery. Methods: ATZ-loaded NLC was formulated using the quality by design-enabled approach and further optimized by employing the Box–Behnken design. The optimized nanoformulation was then characterized for several in vitro and in vivo assessments. Results: The optimized NLC showed small particle size of 227.6 ± 5.4 nm, high entrapment efficiency (71.09% ± 5.84%) and high drug loading capacity (8.12% ± 2.7%). The release pattern was observed to be biphasic exhibiting fast release (60%) during the initial 2 h, then trailed by the sustained release. ATZ-NLC demonstrated a 2.36-fold increase in the cumulative drug permeated across the rat intestine as compared to suspension. Pharmacokinetic studies revealed 2.75-folds greater Cmax in the brain and 4-fold improvement in brain bioavailability signifying the superiority of NLC formulation over drug suspension. Conclusion: Thus, NLC could be a promising avenue for encapsulating hydrophobic drugs and delivering it to their target site. The results suggested that increase in bioavailability and brain-targeted delivery by NLC, in all plausibility, help in improving the therapeutic prospects of atazanavir.
Changes in Beneficial C-glycosylflavones and Policosanol Content in Wheat and Barley Sprouts Subjected to Differential LED Light Conditions
Authors: Muthusamy Muthusamy , Kim Jong Hee , Kim Suk Hee , Kim Joo Yeol , Heo Jeong Wook , Lee HanGyeol , Lee Kwang-Sik , Seo Woo Duck , Park Soyoung , Kim Jin A , Lee Soo In
Published: November 2020

The spectral quality and intensity of light, photoperiodism, and other environmental factors have profound impacts on the metabolic composition of light-dependent higher plants. Hence, we investigate the effects of fluorescent light (96 μmol m−2s−1) and white (100 μmol m−2s−1), blue (100 μmol m−2s−1), and red (93 μmol m−2s−1) light-emitting diode (LED) light irradiation on the C-glycosylflavone and policosanol contents in young seedlings of wheat and barley. Ultra-high-performance liquid chromatography (UHPLC) analyses of C-glycosylflavone contents in barley reveal that the saponarin content is significantly enhanced under blue LED light irradiation. Under similar conditions, isoorientin and isoschaftoside contents are improved in wheat seedlings. The contents of these C-glycosylflavones differed along with the light quality and growth period. The highest accumulation was observed in sprouts after three days under blue LED light irradiation. GC/MS analyses of policosanol contents showed that 1-hexacosanol (C26:o–OH) in barley and 1-octacosanol (C28:o–OH) in wheat seedlings were reduced under LED light irradiation, compared to seedlings under fluorescent light conditions. Nonetheless, the policosanol contents gradually improved with the extension of growth times and treatments, irrespective of the light quality. Additionally, a positive correlation was observed between the expression pattern of biosynthesis-related genes and the respective metabolite content in barley. This study demonstrates that blue LED light irradiation is useful in maximizing the C-glycosylflavone content in barley and wheat sprouts.
Influence of Maternal Habitat on Salinity Tolerance of Zygophyllum coccineum with Regard to Seed Germination and Growth Parameters
Authors: Mohamed Elsayed , Kasem Ahmed M. M. A. , Gobouri Adil A. , Elkelish Amr , Azab Ehab
Published: November 2020

Zygophyllum coccineum is a facultative halophyte widely distributed in desert wadis and coastal areas in Egypt. Here, we investigated the influences of maternal habitat on tolerance to salt stress during germination and seedling growth under salinity (0, 100, 200, 400 mM NaCl) of three populations of Z. coccineum from a saline habitat (Manzala coast) and non-saline habitats (Wadi Houf and Wadi Asyuti). In all populations, seed germination started within two days in distilled water but germination indices were reduced significantly with salt level increase. Germination percentage was not significantly greater for seeds from non-saline habitats than for those from the saline habitat under moderate salinity (100, 200 mM NaCl), but only seeds from the saline habitat were able to germinate under high salt stress (400 mM NaCl). Germination recovery was greater for seeds from the saline habitat compared to non-saline populations. At the seedling level, the Manzala population showed the lowest inhibition of shoot length and leaf area under salinity (200 and 400 mM NaCl) compared to non-saline habitats. In the same context, the Manzala population had the maximum chlorophyll a content, superoxide dismutase and esterase activities under salinity compared to non-saline populations, but salinity had a non-significant effect on chlorophyll b between the three populations. Carotenoids were enhanced with the increase of salt levels in all populations. These results suggest the salt tolerance of Manzala population is derived from maternal salinity and adaptive plasticity of this species may play an important role in the wide distribution of Z. coccineum.
Sacred Covenant and Huguenot Ideology of Resistance: The Biblical Image of the Contractual Monarchy in Vindiciae, Contra Tyrannos
Authors: Sălăvăstru Andrei Constantin
Published: November 2020

The Bible had been a fundamental source of legitimacy for the French monarchy, with biblical imagery wielded as a powerful propaganda weapon in the ideological warfare which the kings of France often had to wage. All Christian monarchies tried to build around themselves a sacral aura, but the French kings had soon set themselves apart: they were the “most Christian”, anointed with holy oil brought from heaven, endowed with the power of healing, and the eldest sons of the Church. Biblical text was called upon to support this image of the monarchy, as the kings of France were depicted as following in the footsteps of the virtuous kings of the Old Testament and possessing the necessary biblical virtues. However, the Bible could prove a double-edged sword which could be turned against the monarchy, as the ideological battles unleashed by the Reformation were to prove. In search for a justification for their resistance against the French Crown, in particular after 1572, the Huguenots polemicists looked to the Bible in order to find examples of limited monarchies and overthrown tyrants. In putting forward the template of a proto-constitutional monarchy, one of the notions advanced by the Huguenots was the Biblical covenant between God, kings and the people, which imposed limits and obligations on the kings. This paper aims to examine the occurrence of this image in Vindiciae, contra tyrannos (1579), one of the most important Huguenot political works advocating resistance against tyrannical kings, and the role it played in the construction of the Huguenot theory of resistance.
Assessment of Valuable and Critical Elements Recovery Potential in Ashes from Processes of Solid Municipal Waste and Sewage Sludge Thermal Treatment
Authors: Kasina Monika , Kowalski Piotr Rafał , Kajdas Bartłomiej , Michalik Marek
Published: November 2020

Due to the increasing amount of produced and accumulated wastes, a potential source of elements might be the global waste stream coming from the waste incineration process. As a result of this process, bottom ash, fly ash and air pollution control residues are produced. The goal of this study was to evaluate the raw material potential of the anthropogenic materials which are fly ashes from municipal waste incineration and municipal sewage sludge incineration, and the possibility for the recovery of metallic or other economically valuable elements by comparison of their chemical composition with the chemical composition of Earth materials (ultramafic, mafic and felsic igneous rocks, various sedimentary rocks), and with their lowest content in currently exploited ores. Fly ashes contain more valuable and critical elements when compared to Earth materials; however, they are less concentrated in comparison to the content in currently exploited ores. Since natural resources are becoming depleted, the costs of exploitation, mineral processing and related operations are increasing and the fly ashes are easily accessible. Cheap materials do not demand complicated treatment which might be considered as a future source of P, Zn, Sn, Cr, Pb, Au and Ag, and thus fulfilling the assumptions of close-loop economy and to maximize natural resources protection.
Monitoring Bark Beetle Forest Damage in Central Europe. A Remote Sensing Approach Validated with Field Data
Authors: Fernandez-Carrillo Angel , Patočka Zdeněk , Dobrovolný Lumír , Franco-Nieto Antonio , Revilla-Romero Beatriz
Published: November 2020

Over the last decades, climate change has triggered an increase in the frequency of spruce bark beetle (Ips typographus L.) in Central Europe. More than 50% of forests in the Czech Republic are seriously threatened by this pest, leading to high ecological and economic losses. The exponential increase of bark beetle infestation hinders the implementation of costly field campaigns to prevent and mitigate its effects. Remote sensing may help to overcome such limitations as it provides frequent and spatially continuous data on vegetation condition. Using Sentinel-2 images as main input, two models have been developed to test the ability of this data source to map bark beetle damage and severity. All models were based on a change detection approach, and required the generation of previous forest mask and dominant species maps. The first damage mapping model was developed for 2019 and 2020, and it was based on bi-temporal regressions in spruce areas to estimate forest vitality and bark beetle damage. A second model was developed for 2020 considering all forest area, but excluding clear-cuts and completely dead areas, in order to map only changes in stands dominated by alive trees. The three products were validated with in situ data. All the maps showed high accuracies (acc > 0.80). Accuracy was higher than 0.95 and F1-score was higher than 0.88 for areas with high severity, with omission errors under 0.09 in all cases. This confirmed the ability of all the models to detect bark beetle attack at the last phases. Areas with no damage or low severity showed more complex results. The no damage category yielded greater commission errors and relative bias (CEs = 0.30–0.42, relB = 0.42–0.51). The similar results obtained for 2020 leaving out clear-cuts and dead trees proved that the proposed methods could be used to help forest managers fight bark beetle pests. These biotic damage products based on Sentinel-2 can be set up for any location to derive regular forest vitality maps and inform of early damage.
High-Sensitivity Large-Area Photodiode Read-Out Using a Divide-and-Conquer Technique
Authors: Royo Guillermo , Sánchez-Azqueta Carlos , Aldea Concepción , Celma Santiago
Published: November 2020

In this letter, we present a novel technique to increase the sensitivity of optical read-out with large integrated photodiodes (PD). It consists of manufacturing the PD in several pieces, instead of a single device, and connecting a dedicated transimpedance amplifier (TIA) to each of these pieces. The output signals of the TIAs are combined, achieving a higher signal-to-noise ratio than with the traditional approach. This work shows a remarkable improvement in the sensitivity and transimpedance without the need for additional modifications or compensation techniques. As a result, an increase in sensitivity of 7.9 dBm and transimpedance of 8.7 dBΩ for the same bandwidth is achieved when dividing the photodiode read-out into 16 parallel paths. The proposed divide-and-conquer technique can be applied to any TIA design, and it is also independent of the core amplifier structure and fabrication process, which means it is compatible with every technology allowing the integration of PDs.
Motion Inference Using Sparse Inertial Sensors, Self-Supervised Learning, and a New Dataset of Unscripted Human Motion
Authors: Geissinger Jack H. , Asbeck Alan T.
Published: November 2020

In recent years, wearable sensors have become common, with possible applications in biomechanical monitoring, sports and fitness training, rehabilitation, assistive devices, or human-computer interaction. Our goal was to achieve accurate kinematics estimates using a small number of sensors. To accomplish this, we introduced a new dataset (the Virginia Tech Natural Motion Dataset) of full-body human motion capture using XSens MVN Link that contains more than 40 h of unscripted daily life motion in the open world. Using this dataset, we conducted self-supervised machine learning to do kinematics inference: we predicted the complete kinematics of the upper body or full body using a reduced set of sensors (3 or 4 for the upper body, 5 or 6 for the full body). We used several sequence-to-sequence (Seq2Seq) and Transformer models for motion inference. We compared the results using four different machine learning models and four different configurations of sensor placements. Our models produced mean angular errors of 10–15 degrees for both the upper body and full body, as well as worst-case errors of less than 30 degrees. The dataset and our machine learning code are freely available.
Agreement of Gait Events Detection during Treadmill Backward Walking by Kinematic Data and Inertial Motion Units
Authors: Gottlieb Uri , Balasukumaran Tharani , Hoffman Jay R. , Springer Shmuel
Published: November 2020

Backward walking (BW) is being increasingly used in neurologic and orthopedic rehabilitation as well as in sports to promote balance control as it provides a unique challenge to the sensorimotor control system. The identification of initial foot contact (IC) and terminal foot contact (TC) events is crucial for gait analysis. Data of optical motion capture (OMC) kinematics and inertial motion units (IMUs) are commonly used to detect gait events during forward walking (FW). However, the agreement between such methods during BW has not been investigated. In this study, the OMC kinematics and inertial data of 10 healthy young adults were recorded during BW and FW on a treadmill at different speeds. Gait events were measured using both kinematics and inertial data and then evaluated for agreement. Excellent reliability (Interclass Correlation > 0.9) was achieved for the identification of both IC and TC. The absolute differences between methods during BW were 18.5 ± 18.3 and 20.4 ± 15.2 ms for IC and TC, respectively, compared to 9.1 ± 9.6 and 10.0 ± 14.9 for IC and TC, respectively, during FW. The high levels of agreement between methods indicate that both may be used for some applications of BW gait analysis.
Non-Invasive Sheep Biometrics Obtained by Computer Vision Algorithms and Machine Learning Modeling Using Integrated Visible/Infrared Thermal Cameras
Authors: Fuentes Sigfredo , Gonzalez Viejo Claudia , Chauhan Surinder S. , Joy Aleena , Tongson Eden , Dunshea Frank R.
Published: November 2020

Live sheep export has become a public concern. This study aimed to test a non-contact biometric system based on artificial intelligence to assess heat stress of sheep to be potentially used as automated animal welfare assessment in farms and while in transport. Skin temperature (°C) from head features were extracted from infrared thermal videos (IRTV) using automated tracking algorithms. Two parameter engineering procedures from RGB videos were performed to assess Heart Rate (HR) in beats per minute (BPM) and respiration rate (RR) in breaths per minute (BrPM): (i) using changes in luminosity of the green (G) channel and (ii) changes in the green to red (a) from the CIELAB color scale. A supervised machine learning (ML) classification model was developed using raw RR parameters as inputs to classify cutoff frequencies for low, medium, and high respiration rate (Model 1). A supervised ML regression model was developed using raw HR and RR parameters from Model 1 (Model 2). Results showed that Models 1 and 2 were highly accurate in the estimation of RR frequency level with 96% overall accuracy (Model 1), and HR and RR with R = 0.94 and slope = 0.76 (Model 2) without statistical signs of overfitting
Improvement of Robot Accuracy with an Optical Tracking System
Authors: Liu Ying , Li Yuwen , Zhuang Zhenghao , Song Tao
Published: November 2020

Robot positioning accuracy plays an important role in industrial automation applications. In this paper, a method is proposed for the improvement of robot accuracy with an optical tracking system that integrates a least-square numerical algorithm for the identification of kinematic parameters. In the process of establishing the system kinematics model, the positioning errors of the tool and the robot base, and the errors of the Denavit-Hartenberg parameters are all considered. In addition, the linear dependence among the parameters is analyzed. Numerical simulation based on a 6-axis UR robot is performed to validate the effectiveness of the proposed method. Then, the method is implemented on the actual robot, and the experimental results show that the robots can reach desired poses with an accuracy of ±0.35 mm for position and ±0.07° for orientation. Benefitting from the optical tracking system, the proposed procedure can be easily automated to improve the robot accuracy for applications requiring high positioning accuracy such as riveting, drill, and precise assembly.
What Role Does Rural Place Play in the Lives of Mid-Life Women in Sweden and Ireland?
Authors: Herbert Alison
Published: November 2020

Rural place is a significant influencer of the ageing and states of well-being experienced by older women. This paper extends existing knowledge on gendered rural place by examining its influence on mid-life (45–65 years) women in rural Sweden and rural Ireland. This paper also examines rural place identity, self-identity and the enhancement of the self, and the multiple pathways to place attachment at mid-life. Qualitative data were gathered in 2019 from ten women living in Sweden’s rural Värmland region, and in 2012–2013 from 25 women living in Ireland’s rural Connemara region. Adopting a social constructionist approach within a lifecourse framework, methodology was informed by constructivist grounded theory, using one-to-one semi-structured interviews. These distinct studies show both similarity and difference in rural place identity and self-identity among mid-life women, and highlight nuances around place attachment, the home, social relationships, and the natural environment. The data show a compelling need for a greater consideration of the critical and diverse role rural place plays in shaping women’s experiences of ageing and well-being both at mid-life and in older age.
Evaluation of Geomagnetic Induced Current on 275 kV Power Transformer for a Reliable and Sustainable Power System Operation in Malaysia
Authors: Zawawi Anis Adiba , Ab Aziz Nur Fadilah , Ab Kadir Mohd Zainal Abidin , Hashim Halimatun , Mohammed Zmnako
Published: November 2020

Geomagnetic induced current (GIC) occurs as a direct consequence of abnormal space weather which starts from the sun and may flow into a power system network through neutral grounding connections. The flow of GIC through grounded neutral power transformer has been a major concern to researchers since it can potentially affect power system equipment. Most of the previous research was focused on high and mid latitude countries only. However, it has been proven that the GIC is not only limited to high and mid latitudes, but also extends to power systems at lower geographic latitudes. This paper aims to investigate the impacts of GIC on selected 275 kV subpower system networks in Peninsular Malaysia, which is among the low latitude countries. Its impact in terms of magnitude and duration is also assessed together with the use of neutral earthing resistor (NER) as a potential blocking component to reduce the impact of GIC on the Malaysian power system network. Results demonstrated that when GIC exists in the power system, power transformers undergo half-cycle saturation that may lead to a reactive power loss and power system voltage instability. In this case, the power transformer can only withstand a maximum GIC value of 7 A, and beyond this value, if prolonged, may lead to voltage instability. It turned out that GIC magnitude had more impact compared to duration. However, long duration with high magnitude of GIC is the most hazardous to power transformers and could potentially cause major faults in the power system network. As part of mitigation, NER with a value of 315.10 Ω can be used to limit the GIC current flow and thus provide protection to the power system network. Clearly, the issue of GIC undoubtedly affects the reliability, security and sustainability of power system operation, especially networks with highly critical load and capacity and, therefore, thorough studies are required to assess and mitigate this issue.
The Analysis Performance of a Grid-Connected 8.2 kWp Photovoltaic System in the Patagonia Region
Authors: Vidal Humberto , Rivera Marco , Wheeler Patrick , Vicencio Nicolás
Published: November 2020

Solar PV structures for locations at high latitudes in the Northern and Southern Hemispheres are increasingly in the spotlight. The work reported in this paper analyses the behaviour of a grid-connected 8.2 kWp photovoltaic system to either feed on-site electrical loads (a public institution, Corporación Nacional Forestal (CONAF), located 5.5 km south of Punta Arenas, lat. 53° S) or to feed into the electrical grid when the photovoltaic system generation is higher than the on-site load demand. The system simulation uses the PVSyst software with Meteonorm derived and measured climate information sets (ambient temperature, solar irradiation and wind speed). The agreement between the simulated and measured energy yield is analysed including the evaluation of the optimal generation energy of the PV array, the energy that is fed into the network, the performance ratio, and the normalised energy generation per installed kWp. The PV system considered in this work generates 7005.3 kWh/year, out of which only 6778 kWh/year are injected into the grid. The measured annual performance ratio is around 89%. The normalised productions of the inverter output or final system yield, i.e., useful energy, is 3.6 kWh/kWp/day. The measured annual average capacity factor obtained from this study is 15.1%. These performance parameters will encourage greater use of photovoltaic technology in the Chilean Patagonia region.
Cosmic-Ray Extremely Distributed Observatory
Authors: Homola Piotr , Beznosko Dmitriy , Bhatta Gopal , Bibrzycki Łukasz , Borczyńska Michalina , Bratek Łukasz , Budnev Nikolay , Burakowski Dariusz , Alvarez-Castillo David E. , Almeida Cheminant Kevin , Ćwikła Aleksander , Dam-o Punsiri , Dhital Niraj , Duffy Alan R. , Głownia Piotr , Gorzkiewicz Krzysztof , Góra Dariusz , Gupta Alok C. , Hlávková Zuzana , Homola Martin , Jałocha Joanna , Kamiński Robert , Karbowiak Michał , Kasztelan Marcin , Kierepko Renata , Knap Marek , Kovács Péter , Kuliński Szymon , Łozowski Bartosz , Magryś Marek , Medvedev Mikhail V. , Mędrala Justyna , Mietelski Jerzy W. , Miszczyk Justyna , Mozgova Alona , Napolitano Antonio , Nazari Vahab , Ng Y. Jack , Niedźwiecki Michał , Oancea Cristina , Ogan Bogusław , Opiła Gabriela , Oziomek Krzysztof , Pawlik Maciej , Piekarczyk Marcin , Poncyljusz Bożena , Pryga Jerzy , Rosas Matías , Rzecki Krzysztof , Zamora-Saa Jilberto , Smelcerz Katarzyna , Smolek Karel , Stanek Weronika , Stasielak Jarosław , Stuglik Sławomir , Sulma Jolanta , Sushchov Oleksandr , Svanidze Manana , Tam Kyle M. , Tursunov Arman , Vaquero José M. , Wibig Tadeusz , Woźniak Krzysztof W.
Published: November 2020

The Cosmic-Ray Extremely Distributed Observatory (CREDO) is a newly formed, global collaboration dedicated to observing and studying cosmic rays (CR) and cosmic-ray ensembles (CRE): groups of at least two CR with a common primary interaction vertex or the same parent particle. The CREDO program embraces testing known CR and CRE scenarios, and preparing to observe unexpected physics, it is also suitable for multi-messenger and multi-mission applications. Perfectly matched to CREDO capabilities, CRE could be formed both within classical models (e.g., as products of photon–photon interactions), and exotic scenarios (e.g., as results of decay of Super-Heavy Dark Matter particles). Their fronts might be significantly extended in space and time, and they might include cosmic rays of energies spanning the whole cosmic-ray energy spectrum, with a footprint composed of at least two extensive air showers with correlated arrival directions and arrival times. As the CRE are predominantly expected to be spread over large areas and, due to the expected wide energy range of the contributing particles, such a CRE detection might only be feasible when using all available cosmic-ray infrastructure collectively, i.e., as a globally extended network of detectors. Thus, with this review article, the CREDO Collaboration invites the astroparticle physics community to actively join or to contribute to the research dedicated to CRE and, in particular, to pool together cosmic-ray data to support specific CRE detection strategies.
Fault Detection for Complex System under Multi-Operation Conditions Based on Correlation Analysis and Improved Similarity
Authors: Liang Shi , Zeng Jiewei
Published: November 2020

During actual engineering, due to the influence of complex operation conditions, the data of complex systems are distinct, and the range of similarity differs under complex operation conditions. Simultaneously, the length of the data used to calculate the similarity will also impact the result of the fault detection. According to these, this paper proposes a fault detection method based on correlation analysis and improved similarity. In the first place, the complex operation conditions are divided into several simple operation conditions via the existing historical data. In the next place, the length of the data used to calculate the similarity is determined by correlation analysis. Then, an improved similarity calculation method is proposed to make the range of the similarity under multi-operation conditions identical. Finally, this method is applied to the suspension system of the maglev train. The experiment results indicate that the method proposed in this paper can not only detect the fault or abnormal state of the suspension system but also observe the health index (HI) changes of the system at distinct times under multi-operation conditions.
Can Zika Virus Infection in High Risk Pregnant Women Be Differentiated on the Basis of Symptoms?
Authors: Sanchez Clemente Nuria , Brickley Elizabeth , Furquim de Almeida Marcia , Witkin Steven , Duarte Passos Saulo ,   the Jundiai Zika Cohort Group
Published: November 2020

Zika virus (ZIKV) infection in pregnancy is associated with congenital neurological abnormalities. Our understanding of the full clinical spectrum of ZIKV infection is incomplete. Using data from this prospective cohort study consisting of 650 women attending a high-risk pregnancy clinic during the Zika virus outbreak in Brazil, we investigated the extent to which specific symptoms can be utilized to differentiate ZIKV-infected pregnant women from those with other pregnancy-related problems. All were tested for ZIKV in urine by RT–qPCR. Demographic and clinical data including physical symptoms during follow-up were recorded and analyzed with respect to Zika virus exposure status. Forty-eight (7.4%) women were positive for ZIKV by RT–qPCR. The majority (70.8%) were asymptomatic, and only four ZIKV-positive women (8.3%) reported symptoms during pregnancy that met the WHO case definition. Zika-positive and -negative women reported similar frequencies of ZIKV-like symptoms (as per the WHO definition): fever (16.7% vs. 13.6%), arthralgia/arthritis (10.4% vs. 11.3%), rash (4.2% vs. 5.3%), and conjunctivitis (2.1% vs. 3.2%). Most pregnant women positive for ZIKV in urine are asymptomatic and do not deliver a baby with microcephaly. Physical symptoms alone did not differentiate between high-risk pregnant women positive or negative for ZIKV.
Rancang Bangun Aplikasi Sistem Pakar Berbasis Mobile Untuk Mendiagnosis Penyakit Kulit Pada Kucing Persia
Authors: Pangestu Aditya Sugih , Tanamal Rinabi
Published: November 2020

Dalam menjalankan kehidupan sehari-hari, tentunya setiap manusia pasti pernah mengalami kesepian. Banyak orang cenderung memelihara hewan dengan tujuan untuk menghilangkan rasa kesepian tersebut. Salah satu hewan yang banyak dipelihara adalah kucing. Kucing merupakan hewan peliharaan yang cocok dipelihara dengan tujuan menemani kegiatan sehari-hari saat mempunyai waktu luang. Jenis kucing relatif sangat banyak, tetapi banyak orang yang lebih memilih memelihara kucing Persia karena kucing Persia lebih cocok hidup di dalam rumah, relatif tidak berisik, dan lebih mudah dikandangkan. Pada penelitian ini, penyakit yang diteliti hanya penyakit kulit pada kucing Persia. Setiap pemelihara tidak selalu mempunyai waktu luang dalam memperhatikan peliharaan mereka, terutama dalam hal kesehatan karena kurangnya informasi yang didapat. Maka dari itu, penelitian ini bertujuan membantu para pemelihara untuk selalu memperhatikan kesehatan kucing peliharaan mereka dengan menggunakan aplikasi sistem pakar untuk mendiagnosis penyakit kulit pada kucing Persia berbasis mobile. Sistem dibuat dengan menggunakan Thunkable yang merupakan software apps builder untuk membuat aplikasi Android dan iOS tanpa harus melakukan coding di mana user hanya perlu melakukan drag and drop sesuai dengan keinginan dan kebutuhan. Aplikasi sistem pakar ini dibangun dengan Decision Tree untuk mendapatkan keputusan, kemudian dirancang dengan mesin inferensi menggunakan forward chaining sebagai metode untuk menarik kesimpulan dari keputusan yang ada. Untuk mendapatkan suatu keputusan, diperlukan knowledge dari pakar yang ahli pada bidang kesehatan hewan dengan cara melakukan wawancara secara intensif untuk mendapatkan data yang lengkap dan akurat. Dapat disimpulkan dari hasil penelitian ini bahwa aplikasi Meow'Diagnosis berjalan dengan baik dan berguna untuk mendiagnosis penyakit kulit kucing Persia.