bluuebunny/crossref_metadata_2025 huggingface dataset:
A Predictive Model of Antibody Binding in the Presence of IgG-Interacting Bacterial Surface Proteins
Authors: Kumra Ahnlide Vibha , de Neergaard Therese , Sundwall Martin , Ambjörnsson Tobias , Nordenfelt Pontus
Published: March 2021

Many bacteria can interfere with how antibodies bind to their surfaces. This bacterial antibody targeting makes it challenging to predict the immunological function of bacteria-associated antibodies. The M and M-like proteins of group A streptococci (GAS) exhibit IgGFc-binding regions, which they use to reverse IgG binding orientation depending on the host environment. Unraveling the mechanism behind these binding characteristics may identify conditions under which bound IgG can drive an efficient immune response. Here, we have developed a biophysical model for describing these complex protein-antibody interactions. We show how the model can be used as a tool for studying the binding behavior of various IgG samples to M protein by performingin silicosimulations and correlating this data with experimental measurements. Besides its use for mechanistic understanding, this model could potentially be used as a tool to aid in the development of antibody treatments. We illustrate this by simulating how IgG binding to GAS in serum is altered as specified amounts of monoclonal or pooled IgG is added. Phagocytosis experiments link this altered antibody binding to a physiological function and demonstrate that it is possible to predict the effect of an IgG treatment with our model. Our study gives a mechanistic understanding of bacterial antibody targeting and provides a tool for predicting the effect of antibody treatments in the presence of bacteria with IgG-modulating surface proteins.
Treatment With Endothelin-A Receptor Antagonist BQ123 Attenuates Acute Inflammation in Mice Through T-Cell-Dependent Polymorphonuclear Myeloid-Derived Suppressor Cell Activation
Authors: Chen Ziyang , Zhang Xiaogang , Lv Shuaijun , Xing Zhe , Shi Mengyu , Li Xinyao , Chen Meiqi , Zuo Shaowen , Tao Yingxu , Xiao Gang , Liu Jingping , He Yumei
Published: March 2021

The endothelin-A receptor antagonist BQ123 is an effective treatment agent for hypertension and obese cardiomyopathy. However, the role of BQ123 in controlling acute inflammatory diseases and its underlying mechanisms are not well understood. Here, we showed that BQ123 activated polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in mice and that the IL13/STAT6/Arg1 signaling pathway is involved in this process. Importantly, both treatment with BQ123 and the transfer of BQ123-induced PMN-MDSCs (BQ123-MDSCs) were effective in relieving inflammation, including dextran sulfate sodium (DSS)-induced colitis, papain-induced pneumonia, and concanavalin A (ConA)-induced hepatitis, in mice. The treatment effects were mediated by the attenuation of the inflammation associated with the accumulation of PMN-MDSCs in the colon, lung, and liver. However, concurrent injection of Gr1 agonistic antibody with BQ123 induced PMN-MDSC aggravated the observed acute inflammation. Interestingly, no remission of inflammation was observed in Rag2 knockout mice administered BQ123-MDSCs, but co-injection with CD3+ T cells significantly relieved acute inflammation. In summary, BQ123-induced PMN-MDSCs attenuated acute inflammation in a T cell-dependent manner, providing a novel potential strategy to prevent the occurrence of acute inflammation.
Frequency of Effector Memory Cells Expressing Integrin α4β7 Is Associated With TGF-β1 Levels in Therapy Naïve HIV Infected Women With Low CD4+ T Cell Count
Authors: Kasarpalkar Nandini J. , Bhowmick Shilpa , Patel Vainav , Savardekar Lalita , Agrawal Sachee , Shastri Jayanthi , Bhor Vikrant M.
Published: March 2021

Integrin α4β7expressing CD4+T cells are preferred targets for HIV infection and are thought to be predictors of disease progression. Concurrent analysis of integrin α4β7expressing innate and adaptive immune cells was carried out in antiretroviral (ART) therapy naïve HIV infected women in order to determine its contribution to HIV induced immune dysfunction. Our results demonstrate a HIV infection associated decrease in the frequency of integrin α4β7expressing endocervical T cells along with an increase in the frequency of integrin α4β7expressing peripheral monocytes and central memory CD4+T cells, which are considered to be viral reservoirs. We report for the first time an increase in levels of soluble MAdCAM-1 (sMAdCAM-1) in HIV infected individuals as well as an increased frequency and count of integrinβ7HiCD8+memory T cells. Correlation analysis indicates that the frequency of effector memory CD8+T cells expressing integrin α4β7is associated with levels of both sMAdCAM-1 and TGF-β1. The results of this study also suggest HIV induced alterations in T cell homeostasis to be on account of disparate actions of sMAdCAM-1 and TGF-β1 on integrin α4β7expressing T cells. The immune correlates identified in this study warrant further investigation to determine their utility in monitoring disease progression.
A Rapid and Efficient Screening System for Neutralizing Antibodies and Its Application for SARS-CoV-2
Authors: Han Xiaojian , Wang Yingming , Li Shenglong , Hu Chao , Li Tingting , Gu Chenjian , Wang Kai , Shen Meiying , Wang Jianwei , Hu Jie , Wu Ruixin , Mu Song , Gong Fang , Chen Qian , Gao Fengxia , Huang Jingjing , Long Yingyi , Luo Feiyang , Song Shuyi , Long Shunhua , Hao Yanan , Li Luo , Wu Yang , Xu Wei , Cai Xia , Gao Qingzhu , Zhang Guiji , He Changlong , Deng Kun , Du Li , Nai Yaru , Wang Wang , Xie Youhua , Qu Di , Huang Ailong , Tang Ni , Jin Aishun
Published: March 2021

After the pandemic of COVID-19, neutralizing antibodies (NAbs) against SARS-CoV-2 have been developed for the prophylactic and therapeutic purposes. However, few methodologies are described in detail on how to rapidly and efficiently generate effective NAbs to SARS-CoV-2. Here, we integrated and optimized a strategically screening method for NAbs, which has enabled us to obtain SARS-CoV-2 receptor-binding domain (RBD) specific NAbs within 6 days, followed by additional 9 days for antibody production and function analysis. Using this method, we obtained 198 specific Abs against SARS-CoV-2 RBD from the blood samples of COVID-19 convalescent patients, and 96 of them showed neutralizing activity. At least 20% of these NAbs exhibited advanced neutralizing potency and high affinity, with the top two NAbs showing half-maximal inhibitory concentration (IC50) to block authentic SARS-CoV-2 at 9.88 and 11.13 ng/ml, respectively. Altogether, our study provides an effective methodology with high applicable value for discovering potential preventative and therapeutic NAbs for the emerging infectious diseases.
Whom Should Be Saved? A Proposed Ethical Framework for Allocating Scarce Medical Resources to COVID-19 Patients Using Fuzzy Logic
Authors: Saadeh Heba , Saadeh Maha , Almobaideen Wesam
Published: March 2021

COVID-19 is a global pandemic that affected the everyday life activities of billions around the world. It is an unprecedented crisis that the modern world had never experienced before. It mainly affected the economic state and the health care system. The rapid and increasing number of infected patients overwhelmed the healthcare infrastructure, which causes high demand and, thus, shortage in the required staff members and medical resources. This shortage necessitates practical and ethical suggestions to guide clinicians and medical centers when allocating and reallocating scarce resources for and between COVID-19 patients. Many studies proposed a set of ethical principles that should be applied and implemented to address this problem. In this study, five different ethical principles based on the most commonly recommended principles and aligned with WHO guidelines and state-of-the-art practices proposed in the literature were identified, and recommendations for their applications were discussed. Furthermore, a recent study highlighted physicians' propensity to apply a combination of more than one ethical principle while prioritizing the medical resource allocation. Based on that, an ethical framework that is based on Fuzzy inference systems was proposed. The proposed framework's input is the identified ethical principles, and the output is a weighted value (per patient). This value can be used as a rank or a priority factor given to the patients based on their condition and other relevant information, like the severity of their disease status. The main idea of implementing fuzzy logic in the framework is to combine more than one principle when calculating the weighted value, hence mimicking what some physicians apply in practice. Moreover, the framework's rules are aligned with the identified ethical principles. This framework can help clinicians and guide them while making critical decisions to allocate/reallocate the limited medical resources during the current COVID-19 crisis and future similar pandemics.
Determining Trap Compliances, Microsphere Size Variations, and Response Linearities in Single DNA Molecule Elasticity Measurements with Optical Tweezers
Authors: Mo Youbin , Fizari Mounir , Koharchik Kristina , Smith Douglas E.
Published: March 2021

We previously introduced the use of DNA molecules for calibration of biophysical force and displacement measurements with optical tweezers. Force and length scale factors can be determined from measurements of DNA stretching. Trap compliance can be determined by fitting the data to a nonlinear DNA elasticity model, however, noise/drift/offsets in the measurement can affect the reliability of this determination. Here we demonstrate a more robust method that uses a linear approximation for DNA elasticity applied to high force range (25–45 pN) data. We show that this method can be used to assess how small variations in microsphere sizes affect DNA length measurements and demonstrate methods for correcting for these errors. We further show that these measurements can be used to check assumed linearities of system responses. Finally, we demonstrate methods combining microsphere imaging and DNA stretching to check the compliance and positioning of individual traps.
Endogenous Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Plays a Protective Effect Against Noise-Induced Hearing Loss
Authors: Ruel Jérôme , Guitton Matthieu J. , Gratias Paul , Lenoir Marc , Shen Sanbing , Puel Jean-Luc , Brabet Philippe , Wang Jing
Published: March 2021

Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a member of the vasoactive intestinal polypeptide (VIP)-the secretin-glucagon family of neuropeptides. They act through two classes of receptors: PACAP type 1 (PAC1) and type 2 (VPAC1 and VPAC2). Among their pleiotropic effects throughout the body, PACAP functions as neuromodulators and neuroprotectors, rescuing neurons from apoptosis, mostly through the PAC1 receptor. To explore the potential protective effect of endogenous PACAP against Noise-induced hearing loss (NIHL), we used a knockout mouse model lacking PAC1 receptor expression (PACR1−/−) and a transgenic humanized mouse model expressing the human PAC1 receptor (TgHPAC1R). Based on complementary approaches combining electrophysiological, histochemical, and molecular biological evaluations, we show PAC1R expression in spiral ganglion neurons and in cochlear apical cells of the organ of Corti. Wild-type (WT), PAC1R−/−, and TgHPAC1R mice exhibit similar auditory thresholds. For most of the frequencies tested after acute noise damage, however, PAC1R−/− mice showed a larger elevation of the auditory threshold than did their WT counterparts. By contrast, in a transgene copy number-dependent fashion, TgHPAC1R mice showed smaller noise-induced elevations of auditory thresholds compared to their WT counterparts. Together, these findings suggest that PACAP could be a candidate for endogenous protection against noise-induced hearing loss.
Changes in Degree Centrality of Network Nodes in Different Frequency Bands in Parkinson’s Disease With Depression and Without Depression
Authors: Liao Haiyan , Yi Jinyao , Cai Sainan , Shen Qin , Liu Qinru , Zhang Lin , Li Junli , Mao Zhenni , Wang Tianyu , Zi Yuheng , Wang Min , Liu Siyu , Liu Jun , Wang Chunyu , Zhu Xiongzhao , Tan Changlian
Published: March 2021

Background

Depression induces an early onset of Parkinson’s disease (PD), aggravates dyskinesia and cognitive impairment, and accelerates disease progression. However, it is very difficult to identify and diagnose PD with depression (PDD) in the early clinical stage. Few studies have suggested that the changes in neural networks are associated with PDD, while degree centrality (DC) has been documented to be effective in detecting brain network changes.

Objectives

The objectives of this study are to explore DC changes between patients with PDD and without depression (PDND) and to find the key brain hubs involved with depression in PD patients.

Methods

One hundred and four PD patients and 54 healthy controls (HCs) underwent brain resting-state functional magnetic resonance imaging. The Data Processing and Analysis of Brain Imaging and Resting-State Functional Magnetic Resonance Data Analysis Toolkit were used for processing and statistical analysis. The DC value of each frequency band was calculated. One-way analysis of variance and a two-sample t-test for post hoc comparison were used to compare the differences of the DC values in different frequency bands among PDD, PDND, and healthy control group. Gaussian random field was used for multiple comparison correction. Pearson correlation analysis was performed between each individual’s DC map and clinical indicators.

Results

The DC value of different brain regions changed in PDD and PDND in different frequency bands. The prefrontal lobe, limbic system, and basal ganglia were the main brain regions involved. PDD patients showed a wider range and more abnormal brain areas in the slow-4 frequency band (0.027–0.073 Hz) compared to the HCs. PDD showed a decreased DC value in the medial frontal gyrus, bilateral cuneus gyrus, right lingual gyrus, bilateral supplementary motor area (SMA), bilateral superior frontal gyrus, and left paracentral lobule, but an increased DC value in the bilateral brainstem, midbrain, bilateral parahippocampal gyrus, cerebellum, left superior temporal gyrus, bilateral insula, left fusiform gyrus, and left caudate nucleus in the traditional frequency band (0.01–0.08 Hz) compared to PDND patients. PDND patients displayed more abnormal functions in the basal ganglia in the slow-4 frequency band.

Conclusion

The DC changes in PDD and PDND are frequency dependent and frequency specific. The medial frontal gyrus, SMA, and limbic system may be the key hubs for depression in PD.
The Relationship Between Breast Milk Components and the Infant Gut Microbiota
Authors: Boudry Gaëlle , Charton Elise , Le Huerou-Luron Isabell , Ferret-Bernard Stéphanie , Le Gall Sophie , Even Sergine , Blat Sophie
Published: March 2021

The assembly of the newborn's gut microbiota during the first months of life is an orchestrated process resulting in specialized microbial ecosystems in the different gut compartments. This process is highly dependent upon environmental factors, and many evidences suggest that early bacterial gut colonization has long-term consequences on host digestive and immune homeostasis but also metabolism and behavior. The early life period is therefore a “window of opportunity” to program health through microbiota modulation. However, the implementation of this promising strategy requires an in-depth understanding of the mechanisms governing gut microbiota assembly. Breastfeeding has been associated with a healthy microbiota in infants. Human milk is a complex food matrix, with numerous components that potentially influence the infant microbiota composition, either by enhancing specific bacteria growth or by limiting the growth of others. The objective of this review is to describe human milk composition and to discuss the established or purported roles of human milk components upon gut microbiota establishment. Finally, the impact of maternal diet on human milk composition is reviewed to assess how maternal diet could be a simple and efficient approach to shape the infant gut microbiota.
Investigation on the Incidence of Syncope in Children and Adolescents Aged 2–18 Years in Changsha
Authors: Hu Erlin , Liu Xiaoyan , Chen Qianqian , Wang Cheng
Published: March 2021

Objectives:Syncope is a common clinical symptom, while there are less relevant literature and targeted research on childhood morbidity. This article makes a cross-section survey on the incidence of syncope in children and adolescents aged 2–18 years in Changsha.

Materials and Methods:There were 4,352 children and adolescents aged 2–18 years randomly selected from six primary and secondary schools and three kindergartens in Changsha from March 2018 to November 2018. There were 4,916 standardized questionnaires issued, and 4,352 (88.53%) valid questionnaires were recovered.

Results:(1) Incidence: 17.37% of children and adolescents aged 2–18 years who had at least more than one syncope; the incidence in the adolescence (28.85%) was higher than that in the school age (8.32%) and in the preschool age (2.71%) (P< 0.01). (2) Age at onset: 13.9 ± 3.1 years old, with a peak age of 16 years. (3) Gender difference: The incidence in adolescent females was higher than that in males (31.72 vs. 26.25%,P< 0.05). In inducements, females had higher rates than males in sweltering environment (P< 0.01), whereas males had higher rates than females in urination (P< 0.05). Dizziness, nausea, sweating, and facial pallor were higher in females than in males in presyncope (P< 0.05).

Conclusions:The incidence of syncope in children and adolescents aged 2–18 years in Changsha is 17.37%. The incidence of syncope is different between males and females in different age groups; there are gender differences in syncope inducements and presyncope.
Osthole Attenuates Macrophage Activation in Experimental Asthma by Inhibitingthe NF-ĸB/MIF Signaling Pathway
Authors: Li Ruyi , Song Peng , Tang Guofang , Wei Jianghong , Rao Lizong , Ma Libing , Jiang Ming , Huang Jianwei , Xu Qing , Wu Jingjie , Lv Qian , Yao Dong , Xiao Bo , Huang Haiming , Lei Liping , Feng Juntao , Mo Biwen
Published: March 2021

Inhibition of activated macrophages is an alternative therapeutic strategy for asthma. We investigated whether a coumarin compound, osthole, isolated from Cnidiummonnieri (L.) Cuss, alleviated macrophage activation in vivo and in vitro. Osthole could reduce expression of a marker of activated macrophages, cluster of differentiation (CD)206, in an ovalbumin-challenge model of asthma in mice. Osthole could also inhibit infiltration of inflammatory cells, collagen deposition and production of proinflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor-ɑ, macrophage migration inhibitory factor (MIF)] in asthmatic mice. In vitro, expression of phosphorylated-IĸBɑ, MIF and M2 cytokines (Ym-1, Fizz-1, arginase-1) in IL-4-induced macrophages decreased upon exposure to the NF-ĸB inhibitor MG-132. In our short hairpin (sh)RNA-MIF-knockdown model, reduced expression of M2 cytokines was detected in the IL-4 + shRNA-MIF group. Osthole could attenuate the proliferation and migration of an IL-4-induced rat alveolar macrophages line (NR8383). Osthole could reduce IL-4-induced translocation of nuclear factor-kappa B (NF-ĸB) in NR8383 cells. Collectively, our results suggest that osthole ameliorates macrophage activation in asthma by suppressing the NF-ĸB/MIF signaling pathway, and might be a potential agent for treating asthma.
Interferon-Lambda 1 Inhibits Staphylococcus aureus Colonization in Human Primary Keratinocytes
Authors: Wu Xia , Zhao Yan , Gu Ying , Li Kun , Wang Xiaojie , Zhang Jianzhong
Published: March 2021

Atopic dermatitis (AD) is a common inflammatory skin disease. Staphylococcus aureus (S. aureus) colonization in skin lesions occurs in approximately 70% of AD patients. It has been found that IFN-λ1 can inhibit the colonization of S. aureus in normal human nasal mucosa. IFN-λ1 can increase IL-28RA in infected human keratinocytes. In this study, we found that IFN-λ1 can increase mRNA expression of FLG and antimicrobial peptides (AMPs) and inhibit TSLP mRNA expression in infected human keratinocytes. IFN-λ1 can increase intracellular ROS level, decrease STAT1 phosphorylation, and inhibit the colonization of S. aureus in human primary keratinocytes. These effects were attenuated by knocking-down IL-28R and NADPH oxidase inhibitor, suggesting that this function was mediated by JAK-STAT1 signaling pathway. These results suggest that IFN-λ1 might have an inhibitory effect on S. aureus colonization in AD lesions. Our findings might have potential value in the treatment for AD.
The Influence of Contextual Aspects in Talent Development: Interaction Between Relative Age and Birthplace Effects in NBA-Drafted Players
Authors: Leite Nuno , Arede Jorge , Shang Ximing , Calleja-González Julio , Lorenzo Alberto
Published: March 2021

The aims of this study were two-fold: (1) to inspect separately for the relative age and birthplace effects for players selected in the National Basketball Association (NBA) draft; (2) to explore the interaction among these factors and analyse this interaction in players' career performance. The database was obtained from the official records of the players (n = 1,738), who were selected during the annual editions of the NBA Draft from 1990 to 2019. The participants' date of birth was analyzed according to the month of birth and divided into four quartiles. The place of birth was compared to the distribution of the general population' places of birth based on different communities' sizes. Chi-square analysis were used to determine if the relative age and birthplace of the players drafted differed in any systematic way from official census population distributions. Cluster analysis and standardized residuals were calculated to analyse the interaction among the contextual factors and the players' career performance. The data revealed that early-born players (Q1 and Q2) were over-represented. Moreover, players born in smaller cities (<100,000) were over-represented. The interaction analysis revealed that the players born in the bigger communities relate mainly with relatively younger players, and clusters that correspond to players born in smaller communities integrated the relatively older players. No differences were found in the players' career performance. Researchers, coaches and practitioners should be aware of the interaction between contextual factors to help nurture the development of sport talent regardless of age-related issues or communities' size.
Tracking Control of Pneumatic Artificial Muscle-Activated Robot Arm Based on Sliding-Mode Control
Authors: Lin Chih-Jer , Sie Ting-Yi , Chu Wen-Lin , Yau Her-Terng , Ding Chih-Hao
Published: March 2021

This study discusses a circular trajectory tracking function through a proposed pneumatic artificial muscle (PAM)-actuated robot manipulator. First, a dynamic model between a robot arm and a PAM cylinder is introduced. Then the parameters thereof are identified through a genetic algorithm (GA). Finally, PID is used along with a high-order sliding-mode feedback controller to perform circular trajectory tracking. As the experimental results show, the parameters of sampling time and moment of inertia are set to accomplish the trajectory tracking task in this study. In addition, the maximum error between the objective locus and the following locus was 11.3035 mm when applying theta-axis control to the circular trajectory of the robot arm with zero load or lower load. In an experiment of controller comparison, the results demonstrate that a high-order sliding-mode feedback controller is more robust in resisting external interference and the uncertainty of modeling, making the robot arm have good performance when tracking.
Temporal Changes in Sensitivity of Zymoseptoria tritici Field Populations to Different Fungicidal Modes of Action
Authors: Birr Tim , Hasler Mario , Verreet Joseph-Alexander , Klink Holger
Published: March 2021

Septoria tritici blotch (STB; Zymoseptoria tritici), one of the most important foliar diseases in wheat, is mainly controlled by the intensive use of fungicides during crop growth. Unfortunately, Z. tritici field populations have developed various extents of resistance to different groups of fungicides. Due to the complete resistance to quinone outside inhibitors (QoIs), fungicidal control of STB relies mainly on demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs) as well as multi-site inhibitors. In this study, temporal changes in the sensitivity of Z. tritici to selected DMIs (tebuconazole, propiconazole, prothioconazole, prochloraz), SDHIs (boscalid, bixafen), and multi-site inhibitors (chlorothalonil, folpet) were determined in microtiter assays using Z. tritici field populations isolated in 1999, 2009, 2014, and 2020 in a high-disease-pressure and high-fungicide-input area in Northern Germany. For the four tested DMI fungicides, a significant shift towards decreasing sensitivity of Z. tritici field populations was observed between 1999 and 2009, whereby concentrations inhibiting fungal growth by 50% (EC50) increased differentially between the four DMIs. Since 2009, EC50 values of tebuconazole, propiconazole, and prochloraz remain stable, whereas for prothioconazole a slightly increased sensitivity shift was found. A shift in sensitivity of Z. tritici was also determined for both tested SDHI fungicides. In contrast to DMIs, EC50 values of boscalid and bixafen increased continuously between 1999 and 2020, but the increasing EC50 values were much smaller compared to those of the four tested DMIs. No changes in sensitivity of Z. tritici were observed for the multi-site inhibitors chlorothalonil and folpet over the last 21 years. The sensitivity adaptation of Z. tritici to both groups of single-site inhibitors (DMIs, SDHIs) mainly used for STB control represents a major challenge for future wheat cultivation.
Clostridia in Insect Processed Animal Proteins—Is an Epidemiological Problem Possible?
Authors: Grenda Tomasz , Kwiatek Krzysztof , Goldsztejn Magdalena , Sapała Magdalena , Kozieł Nina , Domaradzki Piotr
Published: March 2021

The aim of this study was the evaluation of the insect processed animal protein (IPAP) contamination level by Clostridium spp. Particularly, we screened for the occurrence of pathogenic species of Clostridia. The samples of IPAP were derived from yellow mealworm (Tenebrio molitor) and black soldier fly (Hermetia illucens) available in the Polish market. The IPAPs were added to experimental feeds for poultry. The differences between the contamination levels of the control (without the addition of IPAP) and experimental (with the addition of IPAP) groups were monitored. The samples were also examined by culture and PCR-based methods to detect 16S rDNA and genes determining botulinum toxin (BoNT) production. Statistical significance was noticed among the feed with the IPAP addition, as well as an increase of contamination by Clostridium spp. In one sample of IPAP, the occurrence of ntnh and bont/D genes determining the production of BoNT/D was noticed. However, a positive result was noticed only at the step of the liquid culture; the Clostridium botulinum type D strain was not isolated. Phenotypically, and according to the 16S rDNA analysis, genetically similar strains to C. botulinum species were isolated. Considering the microbiological safety of IPAP and expanding possibility of its use in livestock animal feed, it seems to be reasonable to provide complex risk assessment on the potential transfer of Clostridia into feed compounds, to assure the safety and sustainable development of insect PAP industry.
Multi-Feature Patch-Based Segmentation Technique in the Gray-Centered RGB Color Space for Improved Apple Target Recognition
Authors: Fan Pan , Lang Guodong , Guo Pengju , Liu Zhijie , Yang Fuzeng , Yan Bin , Lei Xiaoyan
Published: March 2021

In the vision system of apple-picking robots, the main challenge is to rapidly and accurately identify the apple targets with varying halation and shadows on their surfaces. To solve this problem, this study proposes a novel, multi-feature, patch-based apple image segmentation technique using the gray-centered red-green-blue (RGB) color space. The developed method presents a multi-feature selection process, which eliminates the effect of halation and shadows in apple images. By exploring all the features of the image, including halation and shadows, in the gray-centered RGB color space, the proposed algorithm, which is a generalization of K-means clustering algorithm, provides an efficient target segmentation result. The proposed method is tested on 240 apple images. It offered an average accuracy rate of 98.79%, a recall rate of 99.91%, an F1 measure of 99.35%, a false positive rate of 0.04%, and a false negative rate of 1.18%. Compared with the classical segmentation methods and conventional clustering algorithms, as well as the popular deep-learning segmentation algorithms, the proposed method can perform with high efficiency and accuracy to guide robotic harvesting.
Influence of Fly Ash and Polyacrylamide Mixtures on Growth Properties of Artemisia ordosica in the Desert Region of North China
Authors: Niu Jiping , Su Xiaoling , Tang Zejun
Published: March 2021

This study investigated the effects of consolidated soil layer (CSL) composed of fly ash (FA) and polyacrylamide (PAM) on the growth of Artemisia ordosica through plot experiments in Inner Mongolia, North China. It could provide a feasibility reference for ecological restoration and combating desertification in the desert areas. The germination and growth characteristics of Artemisia ordosica were studied in the control soil and 6 kinds of CSL, which were formed with 3 addition rates of FA (5%, 10%, and 15% (w/w) soil) and 2 addition rates of PAM (0.006% and 0.012% (w/w) soil). The results showed that CSL could provide good growth conditions for Artemisia ordosica in arid regions, especially for plant height, basal diameter, total fresh weight, and total dry weight in F5P1 as seen in 2017 and 2018. The FA, the PAM, and the interaction of FA and PAM all had significant impacts on the percentage of seedling emergence and total fresh weight (p < 0.05). The effects of CSL on the emergence and growth properties of Artemisia ordosica were evaluated by principal component analysis, and the CSL consisting of 5% FA and 0.006% PAM was recommended for plant growth.
The Effects of Various Doses and Types of Effective Microorganism Applications on Microbial and Enzyme Activity of Medium and the Photosynthetic Activity of Scarlet Sage
Authors: Borowiak Klaudia , Wolna-Maruwka Agnieszka , Niewiadomska Alicja , Budka Anna , Schroeter-Zakrzewska Anita , Stasik Rafał
Published: March 2021

The aim of this study was to examine the influence of various types and levels of effective microorganism (EM) applications on scarlet sage. For this purpose, EMs were applied at the following three concentrations: 1:10, 1:50, and 1:100. Moreover, two types of treatments (spraying and watering) and a combination of the two were also examined. Photosynthetic intensity was analyzed, including the net photosynthesis rate (PN), stomatal conductance (gS), and intercellular CO2 concentration (Ci). Additionally, chlorophyll a, b, and a + b, and the chlorophyll b/a ratio were analyzed. The microbial content in the medium and soil enzyme activity were also evaluated to examine the effect of EMs on soil biological properties. The investigations revealed a high positive effect of EMs on the photosynthetic activity of most EM combinations compared with the control. The greatest positive effect was noted for the highest EM concentration application for both types of treatments. There was no such influence on soil activity. An increase was noted only in the number of fungi and dehydrogenase activity, while the rest of the soil biological status parameters revealed significant variability, and mostly small or no effects were recorded.
Implications of Antibiotic Use during the COVID-19 Pandemic: The Example of Associated Antimicrobial Resistance in Latin America
Authors: Álvarez-Moreno Carlos , Valderrama-Beltrán Sandra , Rodriguez-Morales Alfonso J.
Published: March 2021

Antimicrobials are essential for infection management [...]
Quantity and Quality of Aquaculture Enrichments Influence Disease Epidemics and Provide Ecological Alternatives to Antibiotics
Authors: Karvonen Anssi , Räihä Ville , Klemme Ines , Ashrafi Roghaieh , Hyvärinen Pekka , Sundberg Lotta-Riina
Published: March 2021

Environmental heterogeneity is a central component influencing the virulence and epidemiology of infectious diseases. The number and distribution of susceptible hosts determines disease transmission opportunities, shifting the epidemiological threshold between the spread and fadeout of a disease. Similarly, the presence and diversity of other hosts, pathogens and environmental microbes, may inhibit or accelerate an epidemic. This has important applied implications in farming environments, where high numbers of susceptible hosts are maintained in conditions of minimal environmental heterogeneity. We investigated how the quantity and quality of aquaculture enrichments (few vs. many stones; clean stones vs. stones conditioned in lake water) influenced the severity of infection of a pathogenic bacterium, Flavobacterium columnare, in salmonid fishes. We found that the conditioning of the stones significantly increased host survival in rearing tanks with few stones. A similar effect of increased host survival was also observed with a higher number of unconditioned stones. These results suggest that a simple increase in the heterogeneity of aquaculture environment can significantly reduce the impact of diseases, most likely operating through a reduction in pathogen transmission (stone quantity) and the formation of beneficial microbial communities (stone quality). This supports enriched rearing as an ecological and economic way to prevent bacterial infections with the minimal use of antimicrobials.
Repurposing of the Tamoxifen Metabolites to Combat Infections by Multidrug-Resistant Gram-Negative Bacilli
Authors: Miró-Canturri Andrea , Ayerbe-Algaba Rafael , Vila-Domínguez Andrea , Jiménez-Mejías Manuel E. , Pachón Jerónimo , Smani Younes
Published: March 2021

The development of new strategic antimicrobial therapeutic approaches, such as drug repurposing, has become an urgent need. Previously, we reported that tamoxifen presents therapeutic efficacy against multidrug-resistant (MDR) Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli in experimental infection models by modulating innate immune system cell traffic. The main objective of this study was to analyze the activity of N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen, three major metabolites of tamoxifen, against these pathogens. We showed that immunosuppressed mice infected with A. baumannii, P. aeruginosa, or E. coli in peritoneal sepsis models and treated with tamoxifen at 80 mg/kg/d for three days still reduced the bacterial load in tissues and blood. Moreover, it increased mice survival to 66.7% (for A. baumannii and E. coli) and 16.7% (for P. aeruginosa) when compared with immunocompetent mice. Further, susceptibility and time-kill assays showed that N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen exhibited minimum inhibitory concentration of the 90% of the isolates (MIC90) values of 16 mg/L, and were bactericidal against clinical isolates of A. baumannii and E. coli. This antimicrobial activity of tamoxifen metabolites paralleled an increased membrane permeability of A. baumannii and E. coli without affecting their outer membrane proteins profiles. Together, these data showed that tamoxifen metabolites presented antibacterial activity against MDR A. baumannii and E. coli, and may be a potential alternative for the treatment of infections caused by these two pathogens.
Cystic Fibrosis: Recent Insights into Inhaled Antibiotic Treatment and Future Perspectives
Authors: Taccetti Giovanni , Francalanci Michela , Pizzamiglio Giovanna , Messore Barbara , Carnovale Vincenzo , Cimino Giuseppe , Cipolli Marco
Published: March 2021

Although new inhaled antibiotics have profoundly improved respiratory diseases in cystic fibrosis (CF) patients, lung infections are still the leading cause of death. Inhaled antibiotics, i.e., colistin, tobramycin, aztreonam lysine and levofloxacin, are used as maintenance treatment for CF patients after the development of chronic Pseudomonas aeruginosa (P. aeruginosa) infection. Their use offers advantages over systemic therapy since a relatively high concentration of the drug is delivered directly to the lung, thus, enhancing the pharmacokinetic/pharmacodynamic parameters and decreasing toxicity. Notably, alternating treatment with inhaled antibiotics represents an important strategy for improving patient outcomes. The prevalence of CF patients receiving continuous inhaled antibiotic regimens with different combinations of the anti-P. aeruginosa antibiotic class has been increasing over time. Moreover, these antimicrobial agents are also used for preventing acute pulmonary exacerbations in CF. In this review, the efficacy and safety of the currently available inhaled antibiotics for lung infection treatment in CF patients are discussed, with a particular focus on strategies for eradicating P. aeruginosa and other pathogens. Moreover, the effects of long-term inhaled antibiotic therapy for chronic P. aeruginosa infection and for the prevention of pulmonary exacerbations is reviewed. Finally, how the mucus environment and microbial community richness can influence the efficacy of aerosolized antimicrobial agents is discussed.
Generating Synthetic Fermentation Data of Shindari, a Traditional Jeju Beverage, Using Multiple Imputation Ensemble and Generative Adversarial Networks
Authors: Hazra Debapriya , Byun Yung-Cheol
Published: March 2021

Fermentation is an age-old technique used to preserve food by restoring proper microbial balance. Boiled barley and nuruk are fermented for a short period to produce Shindari, a traditional beverage for the people of Jeju, South Korea. Shindari has been proven to be a drink of multiple health benefits if fermented for an optimal period. It is necessary to predict the ideal fermentation time required by each microbial community to keep the advantages of the microorganisms produced by the fermentation process in Shindari intact and to eliminate contamination. Prediction through machine learning requires past data but the process of obtaining fermentation data of Shindari is time consuming, expensive, and not easily available. Therefore, there is a need to generate synthetic fermentation data to explore various benefits of the drink and to reduce any risk from overfermentation. In this paper, we propose a model that takes incomplete tabular fermentation data of Shindari as input and uses multiple imputation ensemble (MIE) and generative adversarial networks (GAN) to generate synthetic fermentation data that can be later used for prediction and microbial spoilage control. For multiple imputation, we used multivariate imputation by chained equations and random forest imputation, and ensembling was done using the bagging and stacking method. For generating synthetic data, we remodeled the tabular GAN with skip connections and adapted the architecture of Wasserstein GAN with gradient penalty. We compared the performance of our model with other imputation and ensemble models using various evaluation metrics and visual representations. Our GAN model could overcome the mode collapse problem and converged at a faster rate than existing GAN models for synthetic data generation. Experiment results show that our proposed model executes with less error, is more accurate, and generates significantly better synthetic fermentation data compared to other models.
Near-Field Scanning Millimeter-Wave Microscope Operating Inside a Scanning Electron Microscope: Towards Quantitative Electrical Nanocharacterization
Authors: Polovodov Petr , Théron Didier , Lenoir Clément , Deresmes Dominique , Eliet Sophie , Boyaval Christophe , Dambrine Gilles , Haddadi Kamel
Published: March 2021

The main objectives of this work are the development of fundamental extensions to existing scanning microwave microscopy (SMM) technology to achieve quantitative complex impedance measurements at the nanoscale. We developed a SMM operating up to 67 GHz inside a scanning electron microscope, providing unique advantages to tackle issues commonly found in open-air SMMs. Operating in the millimeter-wave frequency range induces high collimation of the evanescent electrical fields in the vicinity of the probe apex, resulting in high spatial resolution and enhanced sensitivity. Operating in a vacuum allows for eliminating the water meniscus on the tip apex, which remains a critical issue to address modeling and quantitative analysis at the nanoscale. In addition, a microstrip probing structure was developed to ensure a transverse electromagnetic mode as close as possible to the tip apex, drastically reducing radiation effects and parasitic apex-to-ground capacitances with available SMM probes. As a demonstration, we describe a standard operating procedure for instrumentation configuration, measurements and data analysis. Measurement performance is exemplarily shown on a staircase microcapacitor sample at 30 GHz.
Intelligent Monitoring Platform to Evaluate the Overall State of People with Neurological Disorders
Authors: Vicente-Samper Jose Maria , Avila-Navarro Ernesto , Esteve Vicente , Sabater-Navarro Jose Maria
Published: March 2021

The percentage of people around the world who are living with some kind of disability or disorder has increased in recent years and continues to rise due to the aging of the population and the increase in chronic health disorders. People with disabilities find problems in performing some of the activities of daily life, such as working, attending school, or participating in social and recreational events. Neurological disorders such as epilepsy, learning disabilities, autism spectrum disorder, or Alzheimer’s, are among the main diseases that affect a large number of this population. However, thanks to the assistive technologies (AT), these people can improve their performance in some of the obstacles presented by their disorders. This paper presents a new system that aims to help people with neurological disorders providing useful information about their pathologies. This novelty system consists of a platform where the physiological and environmental data acquisition, the feature engineering, and the machine learning algorithms are combined to generate customs predictive models that help the user. Finally, to demonstrate the use of the system and the working methodology employed in the platform, a simple example case is presented. This example case carries out an experimentation that presents a user without neurological problems that shows the versatility of the platform and validates that it is possible to get useful information that can feed an intelligent algorithm.
Evolution of the Electricity Distribution Networks—Active Management Architecture Schemes and Microgrid Control Functionalities
Authors: Sirviö Katja H. , Laaksonen Hannu , Kauhaniemi Kimmo , Hatziargyriou Nikos
Published: March 2021

The power system transition to smart grids brings challenges to electricity distribution network development since it involves several stakeholders and actors whose needs must be met to be successful for the electricity network upgrade. The technological challenges arise mainly from the various distributed energy resources (DERs) integration and use and network optimization and security. End-customers play a central role in future network operations. Understanding the network’s evolution through possible network operational scenarios could create a dedicated and reliable roadmap for the various stakeholders’ use. This paper presents a method to develop the evolving operational scenarios and related management schemes, including microgrid control functionalities, and analyzes the evolution of electricity distribution networks considering medium and low voltage grids. The analysis consists of the dynamic descriptions of network operations and the static illustrations of the relationships among classified actors. The method and analysis use an object-oriented and standardized software modeling language, the unified modeling language (UML). Operational descriptions for the four evolution phases of electricity distribution networks are defined and analyzed by Enterprise Architect, a UML tool. This analysis is followed by the active management architecture schemes with the microgrid control functionalities. The graphical models and analysis generated can be used for scenario building in roadmap development, real-time simulations, and management system development. The developed method, presented with high-level use cases (HL-UCs), can be further used to develop and analyze several parallel running control algorithms for DERs providing ancillary services (ASs) in the evolving electricity distribution networks.
Dynamic Neural Network-Based Adaptive Tracking Control for an Autonomous Underwater Vehicle Subject to Modeling and Parametric Uncertainties
Authors: Muñoz Filiberto , Cervantes-Rojas Jorge S. , Valdovinos Jose M. , Sandre-Hernández Omar , Salazar Sergio , Romero Hugo
Published: March 2021

This research presents a way to improve the autonomous maneuvering capability of a four-degrees-of-freedom (4DOF) autonomous underwater vehicle (AUV) to perform trajectory tracking tasks in a disturbed underwater environment. This study considers four second-order input-affine nonlinear equations for the translational (x,y,z) and rotational (heading) dynamics of a real AUV subject to hydrodynamic parameter uncertainties (added mass and damping coefficients), unknown damping dynamics, and external disturbances. We proposed an identification-control scheme for each dynamic named Dynamic Neural Control System (DNCS) as a combination of an adaptive neural controller based on nonparametric identification of the effect of unknown dynamics and external disturbances, and on parametric estimation of the added mass dependent input gain. Several numerical simulations validate the satisfactory performance of the proposed DNCS tracking reference trajectories in comparison with a conventional feedback controller with no adaptive compensation. Some graphics showing dynamic approximation of the lumped disturbance as well as estimation of the parametric uncertainty are depicted, validating effective operation of the proposed DNCS when the system is almost completely unknown.
3D Cavitation Shedding Dynamics: Cavitation Flow-Fluid Vortex Formation Interaction in a Hydrodynamic Torque Converter
Authors: Ran Zilin , Ma Wenxing , Liu Chunbao
Published: March 2021

Recent experiments have shown interactions between the cavitation and fluid vortex formation in a hydrodynamic torque converter. This study aimed to clarify the unsteady cavitation trigger mechanism and flow-induced vibration caused by turbulence–cavitation interactions. The mass transfer cavitation model and modified Reynolds-averaged Navier–Stokes k–ω model were used with a local density correction for turbulent eddy viscosity to investigate the cavitation structure in a hydrodynamic torque converter under various operating conditions. The model results were then validated against test data. The multi-block structured gridding technique was used to develop an orthogonally structured grid of a three-dimensional full-flow passage as an alternative analysis method for the cavitation flow. The results indicated that the re-entrant jet is the main cause of the shedding cavitation and breaking O-type cavitation. The re-entrant jet is driven by the reverse pressure gradient to move upstream towards the stator nose, and it lifts and splits the attached cavitation, which periodically induces shedding cavitation. When the cavitation was considered, the prediction error of the capacity constant was reduced from 13.23% to <5%. This work provides an insight into the cavitation–vortex interactions in a hydrodynamic torque converter, which can be used to improve the prediction accuracy of the hydrodynamic performance.