bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal and perinatal outcomes and placental pathologic examination of 29 SARS‐CoV‐2 infected patients in the third trimester of gestation
Authors: Blasco Santana Luis , Miraval Wong Eduardo , Álvarez‐Troncoso Jorge , Sánchez García Laura , Bartha José L. , Regojo‐Zapata Rita M.
Published: April 2021

Aim

On December 31, 2019, an unknown outbreak of pulmonary disease was reported in China. The novel coronavirus SARS‐CoV‐2 was the etiologic agent of this disease, and responsible of the current pandemic of COVID‐19. Accumulated evidence on placental features is based most on case‐reports and small case‐series, with differing results.

Methods

We gathered a cohort of 29 infected pregnant mothers who delivered 32 newborns, and had placentas available for pathologic examination. Placentas were compared with a control group.

Results

Of the 29 mothers, clinical and radiological features were similar to what was already described in COVID‐19. Pregnancy modified some analytical parameters. One of the mothers succumbed to the disease. Of the 32 newborns, 1 developed an early infection, with positive reverse‐transcriptase polymerase chain reaction (RT‐PCR) at 48 h of life, with an initial RT‐PCR negative. SARS‐CoV‐2 presence was assessed on placental tissue with immunohistochemistry and RT‐PCR, both were negative. All newborns had good clinical outcomes. No differences in morphological placental findings were found among both groups.

Conclusion

Lack of statistically significant differences among case and control groups suggest that placentas from SARS‐CoV‐2 infected mothers represent a cohort of normal placentas only submitted because of maternal SARS‐CoV‐2 status. To the best of our knowledge, no irrefutable cases of vertical transmission have been yet described. Other authors have failed to demonstrate presence of viral RNA in placental tissue. Accumulated knowledge suggests that if vertical transmission is possible, it is a rare event.
Clinical Characteristics and Controllable Risk Factors of Osteoporosis in Elderly Men with Diabetes Mellitus
Authors: Li Chunling , Wang Shufang , Du Mengru , Wei Yihan , Jiang Sheng
Published: April 2021

Objective

To analyze the clinical characteristics and controllable risk factors of osteoporosis in elderly men with type‐2 diabetes mellitus (T2DM).

Methods

A total of 250 elderly OP patients with T2DM were included in the present study. Patients with one or more common chronic diseases (including hypertension, coronary heart disease, heart failure, chronic bronchitis, chronic nephrosis, and cirrhosis), and a course of more than 3 years were defined as complicated with chronic diseases. Blood glucose, cholesterol, triglyceride, low‐density lipoprotein, high‐density lipoprotein, calcium, phosphorus, glycosylated hemoglobin, urea nitrogen, creatinine, fasting insulin, liver function, and 25‐hydroxy vitamin D3 levels were measured. Bone mineral density was also measured.

Results

A total of 16 patients (6.4%) had severe osteoporosis. Furthermore, 66 patients (26.4%) had blood glucose control that reached the standard, while 176 patients (70.4%) used more than two anti‐diabetic drugs. The serum testosterone level was lower than the median in 87 patients (34.8%) and in 56 smokers (22.4%). Furthermore, 138 patients (55.2%) were overweight and obese, six patients (2.4%) were underweight, 197 patients (78.8%) had chronic diseases, 88 patients (35.2%) were sticking to exercise, and 117 patients (46.8%) had less exercise. In addition, 92 patients (36.8%) were treated with osteotrophy‐protective agents, and 24 patients (9.6%) received anti‐osteoporosis therapy. Smoking, poor glycemic control, low testosterone levels, less exercise, and complications with chronic diseases were the most relevant controllable risk factors.

Conclusion

For elderly male osteoporosis patients with type‐2 diabetes, smoking cessation, blood sugar control up to the standard, regular exercise, active prevention and treatment of complications, and appropriate testosterone supplementation are necessary for preventing and curing osteoporosis.
Difference in Therapeutic Strategies for Joint‐Preserving Surgery for Non‐Traumatic Osteonecrosis of the Femoral Head between the United States and Japan: A Review of the Literature
Authors: Kuroda Yutaka , Okuzu Yaichiro , Kawai Toshiyuki , Goto Koji , Matsuda Shuichi
Published: April 2021

For patients with non‐traumatic osteonecrosis of the femoral head (ONFH), core decompression (CD) and bone grafts (BG) are mainly performed in the West, while osteotomy is found to be predominant in Japan. It is not well recognized how the surgical procedures for joint preservation in patients with ONFH are completely different between the United States and Japan. This paper identifies the contexts and the differences in treatment strategies for ONFH between the two countries. We compared the surgical trends of the two countries over three periods, 1997–2001, 2002–2006, and 2007–2011 (the US data for the third period was 2007–2008), based on a 2014 US paper and a 2013 national publication in Japan. We compared the details of surgery for non‐traumatic ONFH under the same conditions in the two reports. For the period 1997–2001, the rates of surgeries for ONFH in the US were as follows: total hip arthroplasty (THA), 86%; CD, 10%; and osteotomy, 0.4%. In Japan, THA was 61%, osteotomy 38%, and CD 0%. For the recent period, 2007–2011 (US 2007–2008), the rate of THA was 91%, CD 6%, and osteotomy 0.1%, in the US, compared to a THA rate of 73%, CD 0%, and osteotomy 26% in Japan. The results for the interim period (2002–2006) were between the old and new data. The use of joint‐preserving surgery for ONFH differs greatly between the US and Japan. The first‐line joint‐preserving surgery was CD in the US and osteotomy in Japan. Each procedure was rarely done in the other country. From about 2000 to 2010, the percentage of THA increased in both countries. The proportion of joint‐preserving surgery (CD in the US and osteotomy in Japan) declined. The decrease in joint‐preserving procedures may be largely attributed to improved long‐term outcomes of THA due to technological advances. There is also a reluctance for young ONFH patients to undergo joint‐preserving procedures, such as osteotomy, that require long‐term hospitalization.
Regional variations of sulfur isotope compositions for metallic deposits in South Korea
Authors: Jo Jaeguk , Jeong Youngah , Shin Dongbok
Published: April 2021

Southern Korean peninsula comprises five major geotectonic provinces, throughout which various metallic deposits are distributed. We reviewed sulfur isotope data (n = 1,574) of sulfide minerals collected from previous works for 177 metallic deposits in the provinces to interpret the sulfur isotope characteristics of each province, comprising different wall rocks and geologic settings. The averaged δ34S values of each metallic deposit associated with Precambrian metamorphic rocks and Jurassic granitoids in the Gyeonggi massif and Yeongnam massif range from −7.1 to +10.3‰ (av. +4.5‰) and from −3.6 to +7.8‰ (av. +3.5‰), respectively. The Taebaeksan basin produced the highest δ34S value among the five, −0.4 to +13.2‰ (av. +6.1‰). This was influenced by sulfate sulfur derived from marine carbonate host rock. The Okcheon metamorphic belt, comprising metasedimentary and metavolcanics rocks, shows an isotope range from +1.9 to +8.3‰ (av. +5.7‰). The sulfur isotope distribution of the Gyeongsang basin with a range from −1.2 to +11.7‰ (av. +5.2‰) can be divided into two zones: higher δ34S values from the inner zone related to the volcanic rocks and magnetite‐series Cretaceous granitoids, and lower δ34S values from the outer zone related to the organic‐rich sedimentary rocks. Sulfur isotope variations of metallic deposits in each geotectonic province were mainly influenced by igneous sulfur and inherent wall rock sulfur sources, 32S‐enriched sedimentary sulfur (e.g., Precambrian metasedimentary rocks and biogenic sulfur‐rich sedimentary rocks), and 34S‐enriched seawater sulfur (e.g., carbonates and acid to intermediate volcanic rocks). These wall rocks also contributed to the changes in δ34S values for granitoid rocks and metallic deposits by time, ore genetic type, and ore species in South Korea.
Mapping Malaria by Sharing Spatial Information Between Incidence and Prevalence Data Sets
Authors: Lucas Tim C. D. , Nandi Anita K. , Chestnutt Elisabeth G. , Twohig Katherine A. , Keddie Suzanne H. , Collins Emma L. , Howes Rosalind E. , Nguyen Michele , Rumisha Susan F. , Python Andre , Arambepola Rohan , Bertozzi-Villa Amelia , Hancock Penelope , Amratia Punam , Battle Katherine E. , Cameron Ewan , Gething Peter W. , Weiss Daniel J.
Published: April 2021

As malaria incidence decreases and more countries move towards elimination, maps of malaria risk in low-prevalence areas are increasingly needed. For low-burden areas, disaggregation regression models have been developed to estimate risk at high spatial resolution from routine surveillance reports aggregated by administrative unit polygons. However, in areas with both routine surveillance data and prevalence surveys, models that make use of the spatial information from prevalence point-surveys might make more accurate predictions. Using case studies in Indonesia, Senegal and Madagascar, we compare the out-of-sample mean absolute error for two methods for incorporating point-level, spatial information into disaggregation regression models. The first simply fits a binomial-likelihood, logit-link, Gaussian random field to prevalence point-surveys to create a new covariate. The second is a multi-likelihood model that is fitted jointly to prevalence point-surveys and polygon incidence data. We find that in most cases there is no difference in mean absolute error between models. In only one case, did the new models perform the best. More generally, our results demonstrate that combining these types of data has the potential to reduce absolute error in estimates of malaria incidence but that simpler baseline models should always be fitted as a benchmark.
How to use laser safely in times of COVID‐19: Systematic review
Authors: Lago Andrea Dias Neves , Cordon Rosely , Gonçalves Leticia Machado , Menezes Carlos Felipe Sousa , Furtado Guilherme Silva , Rodrigues Fernanda Cristina Nogueira , Marques Daniele Meire Conde
Published: April 2021

Aim

To conduct a systematic review of the literature on biosafety with the use of lasers.

Methods

The systematic review of literature was performed using MEDLINE (PubMed), Science Direct and Web of Science databases. The electronic search strategy included terms in the Medical Subject Heading (MeSH) related to biosafety in dentistry and laser, forms of contamination with aerosols, as well as their synonyms. The selected keywords were “aerosol virus transmission dentistry,” “laser‐generated air contaminants,” “biosafety dentistry laser” combined with the terms AND/OR.

Results

A total of 1334 abstracts were reviewed, resulting in inclusion of 23 reviews. The dental surgeons are professionals with a high risk of contamination; high‐power lasers form aerosols that need to be controlled and low‐power lasers must be protected to minimize the risks of cross‐infection.

Conclusion

The biosafety of using lasers is important for professionals can be more oriented as to the correct use of this equipment. This study has the relevance of showing biosafety measures for the professional, staff and patients, as well as suggesting that more studies that are clinical should be conducted in this area.
Regulated hypothermia in response to endotoxin in birds
Authors: Amaral‐Silva Lara do , Gargaglioni Luciane H. , Steiner Alexandre A. , Oliveira Marcos T. , Bícego Kênia Cardoso
Published: April 2021

Key points

The costs associated with immune and thermal responses may exceed the benefits to the host during severe inflammation. In this case, regulated hypothermia instead of fever can occur in rodents as a beneficial strategy to conserve energy for vital functions with consequent tissue protection and hypoxia prevention.

We tested the hypothesis that this phenomenon is not exclusive to mammals, but extends to the other endothermic group, birds.

A decrease in metabolic rate without any failure in mitochondrial respiration, nor oxygen delivery, is the main evidence supporting the regulated nature of endotoxin‐induced hypothermia in chicks.

Thermolytic mechanisms such as tachypnea and cutaneous vasodilatation can also be recruited to facilitate body temperature decrease under lipopolysaccharide treatment, especially in the cold.

Our findings bring a new perspective for evolutionary medicine studies on energy trade‐off in host defence because regulated hypothermia may be a phenomenon spread among vertebrates facing a severe immune challenge.

A switch from fever to regulated hypothermia can occur in mammals under circumstances of reduced physiological fitness (e.g. sepsis) to direct energy to defend vital systems. Birds in which the cost to resist a pathogen is additive to the highest metabolic rate and body temperature (Tb) among vertebrates may also benefit from regulated hypothermia during systemic inflammation. Here, we show that the decrease in Tb observed during an immune challenge in birds is a regulated hypothermia, and not a result of metabolic failure. We investigated O2 consumption (thermogenesis index), ventilation (respiratory heat loss), skin temperature (sensible heat loss) and muscle mitochondrial respiration (thermogenic tissue) during Tb fall in chicken chicks challenged with endotoxin [lipopolysaccharide (LPS)]. Chicks injected with LPS were also tested regarding the capacity to raise O2 consumption to meet an increased demand driven by 2,4‐dinitrophenol. LPS decreased Tb and the metabolic rate of chicks without affecting muscle uncoupled, coupled and non‐coupled mitochondrial respiration. LPS‐challenged chicks were indeed capable of increasing metabolic rate in response to 2,4‐dinitrophenol, indicating no O2 delivery limitation. Additionally, chicks did not attempt to prevent Tb from falling during hypothermia but, instead, activated cutaneous and respiratory thermolytic mechanisms, providing an additional cooling force. These data provide the first evidence of the regulated nature of the hypothermic response to endotoxin in birds. Therefore, it changes the current understanding of bird's thermoregulation during severe inflammation, indicating that regulated hypothermia is either a convergent trait for endotherms or a conserved response among vertebrates, which adds a new perspective for evolutionary medicine research.
Informational masking with speech-on-speech intelligibility: Pupil response and time-course of learning
Authors: Versfeld Niek J. , Lie Sisi , Kramer Sophia E. , Zekveld Adriana A.
Published: April 2021

Previous research has shown a learning effect on speech perception in nonstationary maskers. The present study addressed the time-course of this learning effect and the role of informational masking. To that end, speech reception thresholds (SRTs) were measured for speech in either a stationary noise masker, an interrupted noise masker, or a single-talker masker. The utterance of the single talker was either time-forward (intelligible) or time-reversed (unintelligible), and the sample of the utterance was either frozen (same utterance at each presentation) or random (different utterance at each presentation but from the same speaker). Simultaneously, the pupil dilation response was measured to assess differences in the listening effort between conditions and to track changes in the listening effort over time within each condition. The results showed a learning effect for all conditions but the stationary noise condition—that is, improvement in SRT over time while maintaining equal pupil responses. There were no significant differences in pupil responses between conditions despite large differences in the SRT. Time reversal of the frozen speech affected neither the SRT nor pupil responses.
Flow-induced crystallization of a multiblock copolymer under large amplitude oscillatory shear: Experiments and modeling
Authors: Nébouy Matthias , Chazeau Laurent , Morthomas Julien , Fusco Claudio , Dieudonné-George Philippe , Baeza Guilhem P.
Published: April 2021

Following a previous work investigating the flow-induced crystallization (FIC) of polybutylene terephthalate/polytetrahydrofuran (PBT/PTHF) multiblock copolymers under steady shear, we propose here to deal with the case of large amplitude oscillatory shear (LAOS). For this purpose, we focus on a single copolymer (Mw¯=50kgmol−1) made, in average, of a sequence of nine soft and eight hard segments. We show unambiguously that LAOS accelerates the polymer crystallization when increasing (i) the frequency from 0.5 up to 50 rad s−1 (at a constant strain amplitude of 100%) or (ii) the strain amplitude from 10 to 300% (at a constant frequency of 2.5 rad s−1). Based on this data, we demonstrate that high oscillatory shear rates have similar effects as the steady shear rate regarding the gelation time, i.e., that frequency- and strain amplitude-related effects are secondary. We carefully analyze the stress response through Fourier-transform decomposition that emphasizes the rich rheological behavior of our material during its liquid-to-solid phase transition. With the help of x-ray scattering experiments (ex situ SAXS and WAXS), we then propose a global scenario rationalizing the whole set of rheological observations based on the copolymer structure. In parallel, we propose to use a recent model that we developed to simulate the stress response in the case of steady shear-promoted FIC and adapt it to the case of LAOS. Remarkably, our model, which is based on modified Doi–Edwards equations only, provides good qualitative agreement with the data when varying the strain amplitude or the frequency. Furthermore, it is found to predict quantitatively the gelation time of the system.
Proteolytic Maturation of the Outer Membrane
c
-Type Cytochrome OmcZ by a Subtilisin-Like Serine Protease Is Essential for Optimal Current Production by Geobacter sulfurreducens
Authors: Kai Ayako , Tokuishi Takahiro , Fujikawa Takashi , Kawano Yoshihiro , Ueki Toshiyuki , Nagamine Miyuki , Sakakibara Yoichi , Suiko Masahito , Inoue Kengo
Published: April 2021

Microbial fuel cells are a promising technology for energy generation from various waste types. However, the molecular mechanisms of microbial extracellular electron transfer to the electrode need to be elucidated.
G. sulfurreducens
is a common key player in electricity generation in mixed-culture microbial fuel cell systems and a model microorganism for the study of extracellular electron transfer.
The comparative lake ecology of two allopatric Arctic Charr, Salvelinus alpinus, populations with differing life histories in Cumberland Sound, Nunavut
Authors: Young Angela L. , Tallman Ross F.
Published: April 2021

The lake ecology of high-latitude fishes is strongly influenced by seasonal feeding opportunities and environmental stochasticity in Arctic environments. Arctic Charr (Salvelinus alpinus (Linnaeus, 1758)) populations are prevalent throughout the Arctic and show multiple life history strategies across their range. Unlike Old World populations, the lake ecology of Arctic Charr populations on south Baffin Island remains poorly defined. We examined the comparative seasonal lake ecology of two differing Arctic Charr populations (anadromous and landlocked) in Cumberland Sound, Nunavut. Anadromous Charr showed no evidence of feeding occurring within freshwater once they began seaward migrations. Anadromous Charr achieve sexual maturation at a larger size and younger age than landlocked Charr. Landlocked Charr used more lake habitats than anadromous Charr with feeding opportunities as an apparent influence on habitat selection. Landlocked Charr fed year round. They adopted a cannibalistic feeding strategy in the winter but consumed a variety of prey items in the fall. Littoral habitat was found to be important to all sizes of Charr in both seasons. Smaller anadromous Charr (<350 mm) did not use the benthic habitat. The variable ecology and form demonstrated further emphasizes the phenotypic adaptability of Arctic Charr that allows its widespread distribution in the Arctic.
LncRNA MSC-AS1 facilitates lung adenocarcinoma through sponging miR-33b-5p to up-regulate GPAM
Authors: Li Sai , Yang Shenghui , Qiu Chun , Sun Datong
Published: April 2021

Many reports have indicated that long non-coding RNAs (lncRNAs) are closely associated with the occurrence and development of various cancers. Musculin antisense RNA 1 (MSC-AS1) is a an lncRNA known to act as an oncogene in several types of human cancers; however, its specific function in lung adenocarcinoma (LUAD) is still unclear. For this study, we designed and conducted experiments to clarify the function of the lncRNA MSC-AS1 in LUAD and its underlying mechanisms. We found that the expression of MSC-AS1 was significantly higher in LUAD tissues and cells than that in normal ones. Through loss-of function assays, we confirmed that the proliferation of LUAD cells was significantly restrained by down-regulation of MSC-AS1 and the rate of cell apoptosis was accelerated. The results from our mechanistic experiments showed that MSC-AS1 interacts with microRNA-33b-5p (miR-33b-5p). Moreover, glycerol-3-phosphate acyltransferase, mitochondrial (GPAM) was found to be a direct target gene of miR-33b-5p, and it has similar functions to MSC-AS1. Further, inhibition of miR-33b-5p or overexpression GPAM reversed the inhibitory effects of MSC-AS1 silencing on LUAD cell growth. In short, MSC-AS1 facilitates LUAD progression through sponging miR-33b-5p to up-regulate GPAM.
Stable isotope analysis reveals that humpback whales (Megaptera novaeangliae) primarily consume capelin (Mallotus villosus) in coastal Newfoundland, Canada
Authors: Johnson Kelsey F. , Davoren Gail K.
Published: April 2021

On the Newfoundland (Canada) foraging ground, humpback whales (Megaptera novaeangliae (Borowski, 1781)) are found associated with a dominant forage fish species, capelin (Mallotus villosus (Müller, 1776)), that experienced a population collapse in the early 1990s and has not recovered. Our primary goal was to reconstruct dietary proportions of humpback whales on their summer foraging grounds off the northeast coast of Newfoundland during July–August 2016 and 2017 using a Bayesian stable isotope mixing model (MixSiar). Modelled dietary proportions were similar in both years, with capelin comprising ∼90% of the diet. However, both δ13C and δ15N in humpback whale skin differed significantly between years, resulting in minimal isotopic niche overlap (9%). Lipid-extracted and nonlipid-extracted skin samples were used to develop a lipid normalization equation: Δ13C = –3.184 + 1.011(C:N). Overall, findings suggest that capelin is the primary prey type of humpback whales in coastal Newfoundland, despite the continued collapsed state of the capelin population. Findings also reiterate that dietary reconstruction from stable isotope analysis of cetacean skin can be misinterpreted without concurrently sampled isotopic ratios of potential prey types.
Applying Simulation Optimization for Agile Vehicle Fleet Sizing of Automated Material Handling Systems in Semiconductor Manufacturing
Authors: Chang Kuo-Hao , Cuckler Robert
Published: April 2021

Automated material handling systems (AMHS) have been widely used in semiconductor manufacturing. However, the performance of AMHS heavily hinges on vehicle fleet sizing, which is a complex yet crucial problem. For example, a small fleet size may increase the average wait time, but a large fleet size can also result in traffic congestion. This tradeoff is difficult and can be further exacerbated by profound uncertainty in the manufacturing process. In the literature, the existing models are focused on improving the mean-based performance of AMHS, where the resulting optimal vehicle fleet size is fixed, lacking the ability and flexibility to respond to the changes and/or special requirements that suddenly come up in the manufacturing process. Another drawback with the existing models is that they are not able to characterize the upside/downside risks associated with the resulting vehicle fleet size. This paper, motivated by a real project, presents a novel quantile-based decision model to fill the gap. The adjustment of [Formula: see text] values in the proposed decision model allows for agile vehicle fleet sizing according to the production situations, resulting in the satisfactory performance of AMHS. We develop a simulation optimization solution method, called ES-AMHS in short, to enable the efficient derivation of the optimal vehicle fleet size. A comprehensive numerical analysis is conducted to evaluate the efficiency and efficacy of the solution method. Finally, an empirical study in cooperation with a wafer fab in Taiwan is presented to show the practical usefulness of this methodology in a real-world setting.
Measurements of the cross-section of 111Cd(n,n′)111mCd reaction for 241Am/Be neutrons
Authors: Ahmed G. S. M. , Tohamy M. , Bühler P. , Comsan M. N. H.
Published: April 2021

The cross-section of the [Formula: see text] reaction was measured with [Formula: see text] neutrons using a natural cadmium target [Formula: see text]. The neutron fluence and mean neutron energy of the source were determined using the ISO 8529-1 neutron spectrum and the known cross-sections of the monitor reaction [Formula: see text]. In order to measure the poor [Formula: see text]-ray activity of the reaction products, an HPGe detector with 70% detection efficiency surrounded by an adequate graded shield was applied. The efficiency calculations for the detector were performed using standard point calibration sources and the EFFTRAN efficiency code. Using the measured values of the neutron flux and the induced [Formula: see text]-ray activity of [Formula: see text], the cross-section of the [Formula: see text] reaction at the average neutron energy of 4.05 MeV was found to be [Formula: see text] mb. An estimation of the contribution to the total cross-section by the accompanied reactions [Formula: see text] and [Formula: see text] was achieved and the related cross-sections were found to be 0.16 mb and 8.99 mb, respectively.
EAT-ML: Efficient Automatic Tuning for Machine Learning Models in Cyber Physical System
Authors: Zhang Hongli , Huang Shouming
Published: April 2021

In cyber physical system, the machine learning model is a competitive tool and has been successfully applied in this field. However, applying machine learning models to specific problems requires highly experienced manual tuning, which is a process of constant trial and error. Therefore, it often takes huge resources and time when faced with complex problems. In this paper, we propose an efficient method EAT-ML for automatically tuning machine learning models in cyber physical system. This method can automatically tune the hyperparameters of the machine learning model by using a controller with little human intervention. Specifically, the controller sequentially selects the hyperparameters of the machine learning model, and then uses the accuracy obtained on the verification set as the reward value signal. Finally, the PPO algorithm is used to calculate the loss function to update the internal parameters of the controller. In order to further improve the efficiency of the tuning method, we use the previous optimization experience by reconstructing the advantage function. In the experiment, our proposed method can show the best performance on most tasks by comparing other automatic tuning methods. In addition, the effectiveness and feasibility of the various components of the proposed method are also verified through ablation experiments.
A Unifying Coalgebraic Semantics Framework for Quantum Systems
Authors: Liu Ai , Sun Meng
Published: April 2021

As a quantum counterpart of labeled transition system (LTS), quantum labeled transition system (QLTS) is a powerful formalism for modeling quantum programs or protocols, and gives a categorical understanding for quantum computation. With the help of quantum branching monad, QLTS provides a framework extending some ideas in non-deterministic or probabilistic systems to quantum systems. On the other hand, quantum finite automata (QFA) emerged as a very elegant and simple model for resolving some quantum computational problems. In this paper, we propose the notion of reactive quantum system (RQS), a variant of QLTS capturing reactive system behavior, and develop a coalgebraic semantics for QLTS, RQS and QFA by an endofunctor on the category of convex sets, which has a final coalgebra. Such a coalgebraic semantics provides a unifying abstract interpretation for QLTS, RQS and QFA. The notions of bisimulation and simulation can be employed to compare the behavior of different types of quantum systems and judge whether a coalgebra can be behaviorally simulated by another.
Shrinking braids and left distributive monoid
Authors: Li Linjun
Published: April 2021

We consider a natural generalization of braids which we call shrinking braids. We state the relations of shrinking braids and use them to define algebraically the monoid [Formula: see text]. We endow a subset of [Formula: see text] with a left distributive monoid structure and use it to extend the Dehornoy order on [Formula: see text] to an order on [Formula: see text]. By using this order, we prove that [Formula: see text] is isomorphic to the monoid which is generated (geometrically) by shrinking braids.
Numerical analysis of the generalized Starobinsky inflationary model
Authors: Meza Stefano , Altamirano David , Mughal Muhammad Zahid , Rojas Clara
Published: April 2021

In this work, we study numerically one kind of generalization of the Starobinsky inflationary model (power-law type), which is characterized by the parameter [Formula: see text]. In order to find the parameter [Formula: see text] that fixes with observations, we compute the cosmological parameters [Formula: see text], [Formula: see text] and [Formula: see text] for several values of [Formula: see text]. We have found that the value of [Formula: see text] reproduces the value of [Formula: see text], [Formula: see text] and [Formula: see text] is in agreement with the current observational data.
MULTIPLE OPTIMIZATION ANALYSIS OF MRR, SURFACE ROUGHNESS, SOUND İNTENSITY, ENERGY CONSUMPTION, AND VIBRATION VALUES IN MACHINABILITY OF TC4 TITANIUM ALLOY
Authors: AKKUŞ HARUN
Published: April 2021

Research on machining continues increasingly today. The effects of independent variables (cutting speed, feed rate, cutting depth) on dependent variables (material removal rate (MRR), average surface roughness (Ra), sound intensity, energy consumption, and vibration) are among the most researched topics in machining. It is also important to achieve optimum results with low cost and time savings in machining.

In this study, titanium alloy TC4 material was turned on CNC lathe. Taguchi L[Formula: see text] mixed level design was used in experimental design. MRR, Ra, sound intensity, energy consumption, and vibration values were measured for the determined cutting parameters. The measured values were researched experimentally and statistically. Effective parameters were determined. It was concluded that the cutting parameter that has the greatest effect on MRR, Ra, energy consumption, and vibration is the feed rate. In addition, the depth of cut was the parameter that most affected the sound intensity. Control experiments were carried out after determining the optimum machining parameters. With multiple optimization, the predictions were made with approximately 89% accuracy (92.75% for MRR, 92.49% for Ra, 89.45% for sound intensity, 92.70% for energy consumption, 96.16% for vibration).
On power invariant rings
Authors: Khalifa Mohamed
Published: April 2021

Let [Formula: see text] be a commutative ring with identity, [Formula: see text] be an indeterminate and [Formula: see text] be the set of elements [Formula: see text] of [Formula: see text] such that there exists an [Formula: see text]-homomorphism of rings [Formula: see text] with [Formula: see text]. O’Malley called [Formula: see text] to be power invariant (respectively, strongly power invariant) if whenever [Formula: see text] is a ring such that [Formula: see text] is isomorphic to [Formula: see text] (respectively, whenever [Formula: see text] is a ring and [Formula: see text] is an isomorphism of [Formula: see text] onto [Formula: see text]), then [Formula: see text] and [Formula: see text] are isomorphic (respectively, then there exists an [Formula: see text]-automorphism [Formula: see text] of [Formula: see text] such that [Formula: see text]) [M. O’Malley, Isomorphic power series rings, Pacific J. Math. 41(2) (1972) 503–512]. We prove that a ring [Formula: see text] is power invariant in each of the following case: [Formula: see text] [Formula: see text] is a domain in which [Formula: see text] is comparable to each radical ideal of [Formula: see text] (for instance a domain with Krull dimension one), [Formula: see text] [Formula: see text] is a domain in which Jac[Formula: see text] (i.e. the Jacobson radical of [Formula: see text]) is comparable to each radical ideal of [Formula: see text] and [Formula: see text] [Formula: see text] is a Prüfer domain. Also in each of the aforementioned case, we prove that either [Formula: see text] is strongly power invariant or [Formula: see text] is isomorphic to a quasi-local power series ring. Let [Formula: see text] be a unital module over [Formula: see text]. We show that if [Formula: see text] is reduced and strongly power invariant, then Nagata’s idealization ring [Formula: see text] is strongly power invariant (but the converse is false). Ishibashi called a ring [Formula: see text] to be strongly[Formula: see text]-power invariant if whenever [Formula: see text] is a ring and [Formula: see text] is an isomorphism of [Formula: see text] onto [Formula: see text], then there exists an [Formula: see text]-automorphism [Formula: see text] of [Formula: see text] such that [Formula: see text] for each [Formula: see text]. We prove that if [Formula: see text] is a ring in which [Formula: see text] is nil, then [Formula: see text] is strongly[Formula: see text]-power invariant for all positive integer [Formula: see text]. We deduce that every polynomial ring in finitely many indeterminates is strongly[Formula: see text]-power invariant for all positive integer [Formula: see text].
A NONLINEAR FUZZY LINGUISTIC PREDICTION MODEL FOR ACUTE HYPERGLYCEMIA USING CARDIAC ELECTROPHYSIOLOGICAL SIGNALS
Authors: FENG YU , LUO LINTAO
Published: April 2021

A nonlinear fuzzy linguistic prediction (NFLP) model for acute hyperglycemia prediction is proposed in this paper. The model used IF–THEN expressions which are human-readable and easy to understand. Using cardiac electrophysiological signals as the input, the model can predict actuation durations and concentrations of acute hyperglycemia. The prediction results are compared with the ones of four classical models which are partial least squares (PLS), least-square support vector machine (LSSVM), back-propagation neural network (BPNN) and Takagi–Sugeno (T–S) model. The results show that the proposed method has high prediction accuracy. The method can provide support for clinical diagnosis of acute hyperglycemia.
Improving Reliability Performance of Molecular Communication Based on Drift Diffusion with Ratio Detection Algorithm
Authors: Wang Xinlei , Wu Zhenqiang , Jia Zhen
Published: April 2021

Reliability is a vital issue in the area of communication. In this paper, we particularly investigate the reliability issue for molecular communication based on drift diffusion (MCD2). Since molecules easily accumulate in the channel to produce strong internal symbol interference (ISI), the receiver nanomachine will generate high bit error rate (BER) for the process of decode information. Based on this problem, on the premise of considering channel diffusion noise and ISI noise, the expression of channel BER is deduced to analyze reliability. Then a ratio detection algorithm (RDA) is proposed to reduce BER to improve the reliability performance that enables the receiver nanomachine to adapt the channel condition. Furthermore, an expression of signal to interference plus noise ratio is defined in numerical simulation to verify our goal with different parameters, as well as with the adoption of RDA. The results indicate that the performance of RDA in reducing BER works well in general case in improving reliability performance for MCD2.
On homothetic Killing vectors in stationary axisymmetric vacuum spacetimes
Authors: Sherif Abbas M. , Dunsby Peter K. S. , Goswami Rituparno , Maharaj Sunil D.
Published: April 2021

In this paper, we consider homothetic Killing vectors in the class of stationary axisymmetric vacuum (SAV) spacetimes, where the components of the vectors are functions of the time and radial coordinates. In this case, the component of any homothetic Killing vector along the [Formula: see text] direction must be constant. First, it is shown that either the component along the radial direction is constant or we have the proportionality [Formula: see text], where [Formula: see text]. In both cases, complete analyses are carried out and the general forms of the homothetic Killing vectors are determined. The associated conformal factors are also obtained. The case of vanishing twist in the metric, i.e. [Formula: see text] is considered and the complete forms of the homothetic Killing vectors are determined, as well as the associated conformal factors.
Drying-Induced Pressure Rise and Fracture Mechanics Modeling of the Sphagnum Capsule
Authors: Kang Jingtian , Liu Suixin , Wang Changguo
Published: April 2021

The Sphagnum capsule can disperse spores at an extraordinarily high velocity and acceleration during drying. Briefly, the pressure rise induced by the decrease in the environmental humidity inside the spore chamber causes crack growth between the lid and the capsule wall. At a critical condition, the lid of the capsule suddenly fractures, and the top spores are propelled by the high pressure. Motivated by this phenomenon, we develop a similar mechanics model to study the drying-induced pressure rise and the fracture mechanism of the Sphagnum capsule in this paper. We investigate the drying-induced pressure rise and obtain the deformation configuration for various stiffness ratios of different parts. We also establish a fracture mechanics model and calculate the energy release rate to study the lid separation during the ejection of spores. We find that the energy release rate increases with crack growth when the crack is short, maximizes at an intermediate central crack angle of around [Formula: see text], and gradually decreases with further increase in the central crack depending on the loading type. Such a nonmonotonic relationship between the energy release rate and the crack length can be readily used to explain the spontaneously fast unsteady crack growth and the following potential crack arrest reported in the literature. The results and the modeling method obtained in this paper can be used to explain similar fracture-related spore launching of plants and design bioinspired structures to realize the drying-induced fast movement.
Modeling of Thin Plate Flexural Vibrations by Partition of Unity Finite Element Method
Authors: Zhou Tong , Chazot Jean-Daniel , Perrey-Debain Emmanuel , Cheng Li
Published: April 2021

This paper presents a conforming thin plate bending element based on the Partition of Unity Finite Element Method (PUFEM) for the simulation of steady-state forced vibration. The issue of ensuring the continuity of displacement and slope between elements is addressed by the use of cubic Hermite-type Partition of Unity (PU) functions. With appropriate PU functions, the PUFEM allows the incorporation of the special enrichment functions into the finite elements to better cope with plate oscillations in a broad frequency band. The enrichment strategies consist of the sum of a power series up to a given order and a combination of progressive flexural wave solutions with polynomials. The applicability and the effectiveness of the PUFEM plate elements are first verified via the structural frequency response. Investigation is then carried out to analyze the role of polynomial enrichment orders and enriched plane wave distributions for achieving good computational performance in terms of accuracy and data reduction. Numerical results show that the PUFEM with high-order polynomials and hybrid wave-polynomial combinations can provide highly accurate prediction results by using reduced degrees of freedom and improved rate of convergence, as compared with the classical FEM.
Mineralization and sustainable development in the West African Craton: from field observations to modelling
Authors: Aïfa Tahar
Published: April 2021

This Special Publication combines results obtained by interdisciplinary groups from numerous academic institutions working on Paleoproterozoic formations to decipher the origins of the main mineralization resources in the West African Craton (WAC) and their impacts on African economic development. Structural, geophysical, sedimentological, stratigraphical, geochemical, petrophysical and mineralogical analyses have been used to highlight the complexities involved in mineralization emplacement and its origin and evolution within the WAC. Fourteen articles, mainly of basic research carried out in the WAC and surrounding areas, contribute to new knowledge in mineral research with updated references. They show that the geodynamic evolution of the WAC is complex from one area to another: it involves subduction, collision and obduction during several deformation phases ranging from Birimian (2.3–2.0 Ga) to Pan-African (650–450 Ma) events. Mineralization is mainly controlled by tectonics within shear zones, orogenic belts, basins and faulting systems occurring in the various corridors. Mineralized fluid circulation is stressed and injected into appropriate formations and precipitate several types of well-documented ore deposits: porphyry, metal-bearing, volcanogenic massive sulfide, sedimentary exhalative and lateritic. Various modelling techniques, when integrated, help in understanding the mechanisms of mineralization emplacement, some of which are still a matter of debate. Traditional and industrial exploitation of ore deposits, mainly gold, may inadvertently cause pollution to water tables and rivers, thus affecting the environment including watersheds. The challenge for further studies is mitigation for sustainable development that can be appropriately used to minimize such damage.

The aim of this volume is thus to bring new insights to research activities on ore deposits within the WAC.
A Numerical Study on the Impact of Cathode Catalyst Layer Loading on the Open Circuit Voltage in a Proton Exchange Membrane Fuel Cell
Authors: Moore Michael , Shukla Shantanu , Voss Stephan , Karan Kunal , Weber Adam , Zenyuk Iryna , Secanell Marc
Published: April 2021

The open circuit voltage (OCV) in a proton exchange membrane fuel cell (PEMFC) is typically recorded as being approximately 300 mV lower than the equilibrium voltage computed by the Nernst equation. While a number of causes have been proposed, the voltage drop is generally attributed to the oxidation of crossover hydrogen in the cathode. A single phase, through-the-channel model is presented that includes hydrogen transport across the membrane, an empirical model for the hydrogen oxidation reaction (HOR) fit to experimental data obtained at high potentials and a multi-step kinetic model to describe the oxygen reduction reaction (ORR). Model predictions were compared to experimentally obtained OCVs and the results show that the model is capable of capturing the experimentally observed changes in OCV with platinum loading, as well as fuel cell performance; and that, at low Pt loadings, small quantities of unreacted hydrogen leave the cathode because the HOR is kinetically limited by oxide blocking and anion adsorption. A parametric study is used to show that a minimum OCV is achieved at ultra-low loadings. Results also show that only a multi-step ORR model can simultaneously capture polarization data and the OCV.
Editors’ Choice—Dealloying-Driven Cerium Precipitation on Intermetallic Particles in Aerospace Aluminium Alloys
Authors: Kosari A. , Ahmadi M. , Tichelaar F. , Visser P. , Gonzalez-Garcia Y. , Zandbergen H. , Terryn H. , Mol J. M. C.
Published: April 2021

Cerium-based compounds have been studied for decades as non-toxic candidates for the protection of aerospace aluminium alloys (AAs) like AA2024-T3. However, the complex heterogeneous microstructure of these alloys has hindered a thorough understanding of the subsequent stages of corrosion protection provided by this class of inhibitors. Thus, this work is devoted to unravelling the interaction mechanisms of different intermetallic particles (IMPs) in AA2024-T3 with cerium nitrate at the nanoscopic scale. This has been fulfilled through detailed top-view and cross-sectional analytical TEM investigations along with electrochemical evaluations. In line with our recent findings, we here report dealloying of IMPs as the main factor governing the rate of local cerium precipitation in contrast to micro-galvanic corrosion between IMPs and the surrounding matrix. Furthermore, we discuss a connection between the electrochemical response of the AA2024-T3 system and the morphological and compositional evolutions of individual IMPs including Al2CuMg, Al2Cu, Al7Cu2Fe(Mn) and Al76Cu6Fe7Mn5Si6 at different stages of a 96-h exposure.
Structural, Mechanical and Magnetic Characterization of Rare Earth Double Doped SrBi2Nb2O9 lead Free Ceramics
Authors: Sangula Nagamani , Jaladi Nitchal Kiran , Bhimavarapu Siva Basivi Reddy , Bhuvanagiri Nageswara Rao , Jaladi Anindhya Kiran , Konapala Sambasiva Rao
Published: April 2021

Lead free dielectric materials of Strontium Bismuth Niobate SrBi2Nb2O9 (SBN) and rare earth double doped SrBi1.8Pr0.1Gd0.1Nb2O9 (SBPGN), SrBi1.8Pr0.1Y0.1Nb2O9 (SBPYN), SrBi1.8Eu0.1Gd0.1Nb2O9 (SBEGN) and SrBi1.8Eu0.1Y0.1Nb2O9 (SBEYN) were prepared by two-stage solid-state reaction route. The XRD studies have confirmed the formation of single-phase orthorhombic crystal structure. The microstructural analysis showed the formation of plausible needle shaped grains in the prepared ceramics. The FTIR study was used to investigate the effect of preparation and doping processes on the band intensities of the spectra. Mechanical studies showed that SBEGN and SBEYN ceramics exhibited mild wear (<10−6 mm3 Nm−1) compared to others. The low friction coefficient values of SBPYN (0.044), SBEGN (0.058) and SBEYN (0.002) to that of SBN necessitate lattice strain in these materials. The VSM studies on the rare earth double doped SBN ceramic materials confirmed the induction and existence of magnetic order in SBPGN and SBEGN.