bluuebunny/crossref_metadata_2025 huggingface dataset:
Inferring community assembly mechanisms from functional and phylogenetic diversity: The relative contribution of environmental filtering decreases along a sand desertification gradient in a desert steppe community
Authors: Wang Xing , Song Nai‐Ping , Yang Xin‐Guo , Chen Lin , Qu Wen‐Jie , Wang Lei
Published: February 2021

The stress‐dominance hypothesis (SDH) predicts that environmental filtering will dominate in harsh habitats, while limiting similarity is more important in favourable environments. Here, we test the generality of the SDH to disentangle the relative importance of these two ecological processes along a sand desertification gradient. Data were collected from randomly selected locations in a desert steppe community in Northwest China. In this region, intense habitat fragmentation has resulted in a series of original soil habitat patches called soil islands. These soil islands typically contain Sierozem soils historically subjected to low (L), medium (M), and high (H) levels of sand desertification. Along this sand desertification gradient, soil properties and leaf traits (LDMC, leaf dry matter content; SLA, specific leaf area; LC, leaf carbon concentration; LP, leaf phosphorus concentration; and LN, leaf nitrogen concentration) were measured. We then tested for trait and phylogenetic convergence or divergence using a null model approach. Along the sand desertification gradient, trait convergence trend decreased, while trait divergence trend increased. Similarly, the phylogenetic convergence trends decreased. Traits displaying convergence included LDMC, SLA, and LCC, while LP and LN displayed divergence. The strength of LDMC convergence was negatively correlated with community weighted mean trait values (CWM) for LDMC. In contrast, the strength of LN divergence was positively correlated with CWM for LN. Our results pertaining to LDMC and LN support the SDH. Along the sand desertification gradient, the strength of environmental filtering gradually decreased, while the intensity of limiting similarity gradually increased.
Long‐term assessment of remediation treatments applied to an area affected by a mining spill in Spain
Authors: Pastor‐Jáuregui Rocío , Paniagua‐López Mario , Aguilar‐Garrido Antonio , Martín‐Peinado Francisco , Sierra‐Aragón Manuel
Published: February 2021

This study evaluated the effectiveness of remediation treatments in the long‐term (20 years) for one of the largest mine spills in the world, the Aznalcóllar accident. Soil recovery was carried out through the application of various rates of organic (compost and manure) and inorganic amendments (materials rich in iron oxides and calcium carbonate). Different amendment combinations were grouped in four treatments (T1 to T4) and applied in different sectors depending on the soil properties and the degree of initial contamination. To assess the degree of soil recovery, physicochemical properties, total, water‐soluble, and bioavailable concentrations of the main contaminants (Pb, As, Zn, and Cu) were determined over time. Applied treatments increased pH, calcium carbonate, and organic carbon content of soils, reduced electrical conductivity, and decreased mobility of contaminants, indicating that remediation treatments were efficient recovering soils contaminated by potentially harmful elements (PHEs). However, 20 years after the accident, total concentrations of Pb and As still exceed the intervention levels of the current regulations in certain areas. These areas are located in the sectors closest to the mine and where treatments T1 and T2 were applied. In these cases, the added doses of organic amendments, iron oxide–rich soils, and carbonate amendments were not sufficiently effective, so the application of new treatments is recommended to complete the total recovery of the Guadiamar Green Corridor.
Did anthropause generate a research pause during the pandemic? The experiences of a non‐medical journal
Authors: Zhang Jiao
Published: February 2021

Key points

Contradicting expectations, a non‐medical journal received increasing submissions during the pandemic, even though laboratories remained closed.

Peer reviewers and handling editors were both more responsive and provided faster turnaround times during 2020.

The reasons for increased submission to the journal may have been due to reanalysis of older data or extracting more findings from research done pre‐pandemic.
In‐office insertion tympanostomy tubes in children using single‐pass device
Authors: Truitt Theodore O. , Kosko James R. , Nimmons Grace L. , Raisen Jay , Skovlund Sandra M. , Rimell Frank , Cofer Shelagh A.
Published: February 2021

Objectives

Insertion of tympanostomy tubes (TT) is generally accomplished in children in the operating room under general anesthesia. We report on 229 children treated in‐office with a novel device.

Methods

Investigators participated in an IRB‐approved, prospective, single arm, multisite investigation of in‐office TT placement in awake children. Topical anesthetic was applied, and protective restraint was used. TT placement was performed with a single‐pass TT insertion device. Safety was assessed by monitoring procedural events.

Results

Four hundred and forty‐four ears were treated in 229 children at 10 sites. Children were in age groups 6‐24 months (n = 211, mean = 13 months) and 5‐12 years (n = 18, mean = 8.3 years). Two hundred and fifteen children received bilateral TT placement, and 14 received unilateral placement. Overall, 226/229 (98.7%) children had successful TT placement in the office (209/211 in 6‐24 months and 17/18 in 5‐12 years). Three children were rescheduled for the operating room due to anatomical challenges or patient movement. Median procedure time for bilateral cases in both age groups was 4:53. Two minor adverse events (AEs) were reported in one patient. Per independent assessment of 30 procedure videos by clinicians, TT placement was tolerated acceptably by all children.

Conclusion

In‐office TT placement in awake young children using topical anesthetic, enabled by a single pass delivery device, was safe, successful and well tolerated. The American Academy of Otolaryngology (AAO) recently released a Position Statement supporting in‐office TT placement in appropriate children. These results affirm an in‐office alternative for clinicians and parents who have concerns with the risk, inconvenience and cost of surgery in an operating room under general anesthesia.

Level of Evidence: 2c.

Clinical Trials Registration Number: NCT03544138.
Development and Validation of a Model to Predict Long‐Term Survival After Liver Transplantation
Authors: Goldberg David , Mantero Alejandro , Newcomb Craig , Delgado Cindy , Forde Kimberly , Kaplan David , John Binu , Nuchovich Nadine , Dominguez Barbara , Emanuel Ezekiel , Reese Peter P.
Published: February 2021

Patients are prioritized for liver transplantation (LT) under an “urgency‐based” system using the Model for End‐Stage Liver Disease score. This system focuses solely on waitlist mortality, without considerations of posttransplant morbidity, mortality, and health care use. We sought to develop and internally validate a continuous posttransplant risk score during 5‐year and 10‐year time horizons. This retrospective cohort study used national registry data of adult deceased donor LT (DDLT) recipients with ≥90 days of pretransplant waiting time from February 27, 2002 to December 31, 2018. We fit Cox regression models at 5 and 10 years to estimate beta coefficients for a risk score using manual variable selection and calculated the absolute predicted survival time. Among 21,103 adult DDLT recipients, 11 variables were selected for the final model. The area under the curves at 5 and 10 years were 0.63 (95% confidence interval [CI], 0.60‐0.66) and 0.67 (95% CI, 0.64‐0.70), respectively. The group with the highest (“best”) scores had 5‐year and 10‐year survivals of 89.4% and 85.4%, respectively, compared with 45.9% and 22.2% for those with the lowest (“worst”) scores. Our score was significantly better at predicting long‐term survival compared with the existing scores. We developed and validated a risk score using nearly 17 years of data to prioritize patients with end‐stage liver disease based on projected posttransplant survival. This score can serve as the building block by which the transplant field can change the entire approach to prioritizing patients to an approach that is based on considerations of maximizing benefits (ie, survival benefit–based allocation) rather than simply waitlist mortality.
Influence of microstructure and roughness level on corrosion resistance of the austenitic stainless steel welded joint
Authors: Kovačina Jovanka , Jegdić Bore , Radojković Bojana , Marunkić Dunja , Stevanović Sanja , Simović Anđela
Published: February 2021

The influence of microstructure and surface roughness of the X5CrNi18‐10 austenitic stainless steel‐welded joint on resistance to uniform, pitting, and intergranular corrosion, as well as on the stability of the passive film, was evaluated. The microstructure was revealed by optical microscopy and scanning electron microscopy, whereas surface topography and roughness levels were determined by atomic force microscopy. Corrosion characteristics were obtained by the electrochemical potentiokinetic reactivation method with double loop, electrochemical impedance spectroscopy method, as well as by potentiodynamic measurements. The degree of sensitization of heat‐affected zone (HAZ) was significantly lower than the threshold value required for the occurrence of intergranular corrosion. However, HAZ showed a significantly greater tendency to pitting and uniform corrosion compared to weld metal and base metal. No effect of roughness levels (RMS from 3.6 to 54 nm) on the pitting potential value of the welded joint was observed (unlike in HAZ). The polished surface shows significantly higher corrosion resistance than the grinded surface. Generally, polishing improved corrosion resistance, especially in HAZ, which is very important because HAZ is a critical place for the occurrence of pitting and other types of corrosion.
Phase Morphology of Multiblock Copolymers Differing in Sequence of Blocks
Authors: Behl Marc , Balk Maria , Mansfeld Ulrich , Lendlein Andreas
Published: February 2021

The chemical nature, the number length of integrated building blocks, as well as their sequence structure impact the phase morphology of multiblock copolymers (MBC) consisting of two non‐miscible block types. It is hypothesized that a strictly alternating sequence should impact phase segregation. A library of well‐defined MBC obtained by coupling oligo(ε‐caprolactone) (OCL) of different molecular weights (2, 4, and 8 kDa) with oligotetrahydrofuran (OTHF, 2.9 kDa) via Steglich esterification results in strictly alternating (MBCalt) or random (MBCran) MBC. The three different series has a weight average molecular weight (Mw) of 65 000, 165 000, and 168 000 g mol−1 for MBCalt and 80 500, 100 000, and 147 600 g mol−1 for MBCran. When the chain length of OCL building blocks is increased, the tendency for phase segregation is facilitated, which is attributed to the decrease in chain mobility within the MBC. Furthermore, it is found that the phase segregation disturbs the crystallization by causing heterogeneities in the semi‐crystalline alignment, which is attributed to an increase of the disorder of the OCL semi‐crystalline alignment.
Polythiourethanes Crosslinked with Dynamic Disulfide Bonds: Synthesis via Nonisocyanate Approach, Thermomechanical and Reprocessing Properties
Authors: Ge Wenming , Zhao Bingjie , Liu Weiming , Nie Kangming , Zheng Sixun
Published: February 2021

Polythiourethanes (PTUs) crosslinked with dynamic disulfide bonds are synthesized via a nonisocyanate approach. First, a difunctional five‐membered cyclic trithiocarbonate (1) is synthesized via the reaction of diglycidyl ether of bisphenol A (DGEBA) with carbon disulfide (CS2). Thereafter, the step‐growth polymerizations of 1 with α,ω‐diamino poly(propylene oxide)s with various molar masses are carried out to obtain a series of linear poly(mercapto thiourethane)s. These linear poly(mercapto thiourethane)s are readily crosslinked upon formation of disulfide bonds, which are generated via radical coupling reaction with the side mercapto groups. These crosslinked PTUs can be tailored into the materials from thermosetting plastics to crosslinked elastomers, depending on the molar masses of α,ω‐diamino poly(propylene oxide)s. More importantly, these crosslinked PTUs display excellent reprocessing properties at elevated temperatures, which is attributable to the metathesis reaction of dynamic disulfide bonds.
Photoresponsive Vesicles Enabling Sequential Release of Nitric Oxide (NO) and Gentamicin for Efficient Biofilm Eradication
Authors: Duan Yutian , Zhang Mingyang , Shen Zhiqiang , Zhang Mengdan , Zheng Bin , Cheng Sheng , Hu Jinming
Published: February 2021

The development of new antibacterial agents that can efficiently eradicate biofilms is of crucial importance to combat persistent and chronic bacterial infections. Herein, the fabrication of photoresponsive vesicles capable of the sequential release of nitric oxide (NO) and gentamicin sulfate (GS) is reported, which can not only efficiently disperse Pseudomonas aeruginosa (P. aeruginosa) PAO1 biofilm but also kill the planktonic bacteria. Well‐defined amphiphilic diblockcopolymers of poly(ethylene oxide)‐b‐poly(4‐((2‐nitrobenzyl)(nitroso)amino)benzyl methacrylate) (PNO) is first synthesized through atom transfer radical polymerization (ATRP). The PNO diblock copolymer self‐assembled into vesicles in aqueous solution, and a hydrophilic antibiotic of GS is subsequently encapsulated into the aqueous lumens of vesicles. The vesicles undergo visible light‐mediated N‐NO cleavage, releasing NO and disintegrating the vesicles with the release of the GS payload. The sequential release of NO and GS efficiently eradicate P. aeruginosa PAO1 biofilm and kill the liberated bacteria, showing a better antibiofilm effect than that of NO or GS alone.
Functional and structural characterization of Hyp730, a highly conserved and dormancy‐specific hypothetical membrane protein
Authors: Fannin Stewart , Rangel Jonathan , Bodurin Abiodun P. , Yu Tannon , Mistretta Brandon , Mali Sujina , Gunaratne Preethi , Bark Steven J. , Ebalunode Jerry O. , Khan Arshad , Widger William R. , Sen Mehmet
Published: February 2021

Membrane proteins represent major drug targets, and the ability to determine their functions, structures, and conformational changes will significantly advance mechanistic approaches to both biotechnology and bioremediation, as well as the fight against pathogenic bacteria. A pertinent example is Mycobacterium tuberculosis (H37Rv), which contains ~4000 protein‐coding genes, with almost a thousand having been categorized as ‘membrane protein’, and a few of which (~1%) have been functionally characterized and structurally modeled. However, the functions and structures of most membrane proteins that are sparsely, or only transiently, expressed, but essential in small phenotypic subpopulations or under stress conditions such as persistence or dormancy, remain unknown. Our deep quantitative proteomics profiles revealed that the hypothetical membrane protein 730 (Hyp730) WP_010079730 (protein ID Mlut_RS11895) from M. luteus is upregulated in dormancy despite a ~5‐fold reduction in overall protein diversity. Its H37Rv paralog, Rv1234, showed a similar proteomic signature, but the function of Hyp730‐like proteins has never been characterized. Here, we present an extensive proteomic and transcriptomic analysis of Hyp730 and have also characterized its in vitro recombinant expression, purification, refolding, and essentiality as well as its tertiary fold. Our biophysical studies, circular dichroism, and tryptophan fluorescence are in immediate agreement with in‐depth in silico 3D‐structure prediction, suggesting that Hyp730 is a double‐pass membrane‐spanning protein. Ablation of Hyp730‐expression did not alter M. luteus growth, indicating that Hyp730 is not essential. Structural homology comparisons showed that Hyp730 is highly conserved and non‐redundant in G+C rich Actinobacteria and might be involved, under stress conditions, in an energy‐saving role in respiration during dormancy.
Spatially explicit depiction of a floral epiphytic bacterial community reveals role for environmental filtering within petals
Authors: Hayes Rebecca A. , Rebolleda‐Gómez Maria , Butela Kristen , Cabo Leah F. , Cullen Nevin , Kaufmann Nancy , O'Neill Steffani , Ashman Tia‐Lynn
Published: February 2021

The microbiome of flowers (anthosphere) is an understudied compartment of the plant microbiome. Within the flower, petals represent a heterogeneous environment for microbes in terms of resources and environmental stress. Yet, little is known of drivers of structure and function of the epiphytic microbial community at the within‐petal scale. We characterized the petal microbiome in two co‐flowering plants that differ in the pattern of ultraviolet (UV) absorption along their petals. Bacterial communities were similar between plant hosts, with only rare phylogenetically distant species contributing to differences. The epiphyte community was highly culturable (75% of families) lending confidence in the spatially explicit isolation and characterization of bacteria. In one host, petals were heterogeneous in UV absorption along their length, and in these, there was a negative relationship between growth rate and position on the petal, as well as lower UV tolerance in strains isolated from the UV‐absorbing base than from UV reflecting tip. A similar pattern was not seen in microbes isolated from a second host whose petals had uniform patterning along their length. Across strains, the variation in carbon usage and chemical tolerance followed common phylogenetic patterns. This work highlights the value of petals for spatially explicit explorations of bacteria of the anthosphere.
Evaluation of the occurrence of pathogenic free‐living amoeba and bacteria in 20 public indoor swimming pool facilities
Authors: Reyes‐Batlle María , Gabriel Marta F. , Rodríguez‐Expósito Rubén , Felgueiras Fátima , Sifaoui Ines , Mourão Zenaida , de Oliveira Fernandes Eduardo , Piñero José E. , Lorenzo‐Morales Jacob
Published: February 2021

Recently, indoor swimming pool activities have increased to promote health‐enhancing physical activities, which require establishing suitable protocols for disinfection and water quality control. Normally, the assessment of the microbial quality of the water in the pools only considers the presence of different bacteria. However, other less frequent but more resistant pathogens, such as free‐living amoebas (FLA), are not contemplated in both existing recommendation and research activities. FLA represent a relevant human health risk, not only due to their pathogenicity but also due to the ability to act as vehicles of other pathogens, such as bacteria. Therefore, this work aimed to study the physicochemical characteristics and the occurrence of potentially pathogenic FLA and bacteria in water samples from 20 public indoor swimming facilities in Northern Portugal. Our results showed that some swimming pools presented levels of pH, free chlorine, and conductivity out of the recommended limits. Pathogenic FLA species were detected in two of the facilities under study, where we also report the presence of both, FLA and pathogenic bacteria. Our findings evidence the need to assess the occurrence of FLA and their existence in the same environmental niche as pathogenic bacteria in swimming pool facilities worldwide and to establish recommendations to safeguard the health of the users.
Surgical Management of Parkinson's Disease in the Elderly
Authors: Azevedo Paula , Aquino Camila C. , Fasano Alfonso
Published: February 2021

Background

Deep Brain Stimulation (DBS) is an increasingly popular therapy for Parkinson's Disease (PD). Despite the experience gained over time with DBS of either the subthalamus or the globus pallidus pars interna, there is still no consensus regarding the age limit for DBS indication.

Objectives

This narrative review of the literature discusses the issues of age and DBS, emphasizing the critical need for good quality evidence to support the surgical management of elderly patients with PD.

Methods

We searched PubMed using the terms Parkinson's Disease; Parkinson's Disease therapy; deep brain stimulation; antiparkinsonian agents therapeutic use; age factors; aged; aged, 80 and over; middle aged; treatment outcome; and risk assessments.

Results

We identified several limitations of the available evidence, such as under‐representation of older patients in DBS studies, small sample sizes in studies with older participants, heterogeneity of outcomes, and conflicting results.

Conclusions

Despite preliminary suggestions that age might affect the outcomes of DBS, the evidence to support the hypothesis of age as an independent predictor of DBS outcomes is limited and results are controversial. Ultimately, finding an age‐independent biomarker predicting DBS outcome is the final goal to expand this powerful treatment to all patients age in an effective and safe manner.
Recent advances in proteome‐wide label‐free target deconvolution for bioactive small molecules
Authors: Sun Jichao , Prabhu Nayana , Tang Jun , Yang Fan , Jia Lin , Guo Jinan , Xiao Kefeng , Tam Wai Leong , Nordlund Pär , Dai Lingyun
Published: February 2021

Small‐molecule drugs modulate biological processes and disease states through engagement of target proteins in cells. Assessing drug–target engagement on a proteome‐wide scale is of utmost importance in better understanding the molecular mechanisms of action of observed beneficial and adverse effects, as well as in developing next generation tool compounds and drugs with better efficacies and specificities. However, systematic assessment of drug–target engagement has been an arduous task. With the continuous development of mass spectrometry‐based proteomics instruments and techniques, various chemical proteomics approaches for drug target deconvolution (i.e., the identification of molecular target for drugs) have emerged. Among these, the label‐free target deconvolution approaches that do not involve the chemical modification of compounds of interest, have gained increased attention in the community. Here we provide an overview of the basic principles and recent biological applications of the most important label‐free methods including the cellular thermal shift assay, pulse proteolysis, chemical denaturant and protein precipitation, stability of proteins from rates of oxidation, drug affinity responsive target stability, limited proteolysis, and solvent‐induced protein precipitation. The state‐of‐the‐art technical implications and future outlook for the label‐free approaches are also discussed.
Emerging roles of microRNA‐208a in cardiology and reverse cardio‐oncology
Authors: Wang Xiang , Chen Xinxin , Xu Hui , Zhou Shanshan , Zheng Yang , Keller Bradley B. , Cai Lu
Published: February 2021

Cardiovascular diseases (CVDs) and cancer, which are the leading causes of mortality globally, have been viewed as two distinct diseases. However, the fact that cancer and CVDs may coincide has been noted by cardiologists when taking care of patients with CVDs caused by cancer chemotherapy; this entity is designated cardio‐oncology. More recently, patients with CVDs have also been found to have increased risk of cancers, termed reverse cardio‐oncology. Although reverse cardio‐oncology has been highlighted as an important disease state in recent studies, how the diseased heart affects cancer and the potential mediators of the crosstalk between CVDs and cancer are largely unknown. Here, we focus on the roles of cardiac‐specific microRNA‐208a (miR‐208a) in cardiac and cancer biology and explore its essential roles in reverse cardio‐oncology. Accumulating evidence has shown that within the heart, increased miR‐208a promotes myocardial injury, arrhythmia, cardiac remodeling, and dysfunction and that secreted miR‐208a in the circulation may have novel roles in promoting tumor proliferation and invasion. This review, therefore, provides insights into the novel roles of miR‐208a in reverse cardio‐oncology and strategies to prevent secondary carcinogenesis in patients with early‐ or late‐stage heart failure.
A report on seven fetal cases associated with 15q11‐q13 microdeletion and microduplication
Authors: Huang Xiuzhu , Chen Jieping , Hu Wenlong , Li Lu , He Huiyan , Guo Hui , Liao Qiuyan , Ye Mei , Tang Donge , Dai Yong
Published: February 2021

Background

The 15q11‐q13 region contains three breakpoints (BP1 to BP3), and copy number variations often occur in the region.

Aims

15q11‐q13 microdeletion and microduplication are usually associated with Prader‐Willi and Angelman syndromes, respectively. It is not yet clear to what extent microdeletion and microduplication affect the physical health of the fetus and the child. In this study, we examined seven fetuses ranging in gestational age from 15 to 27 weeks.

Materials & Methods

Detailed prenatal screening and laboratory examinations were performed, while karyotype analysis and chromosomal microarray analysis (CMA) of the amniotic fluid and umbilical cord blood were applied for genetic analysis.

Results

CMA analysis showed that four fetuses harbored a microdeletion and one fetus showed a microduplication at 15q11.2 BP1‐BP2, two fetuses had a microdeletion at 15q11‐q13 BP2‐BP3, and one fetus had an additional microdeletion at 16p13.11.

Discussion

There is no clear standard for the clinical diagnosis of 15q11‐q13 microdeletion and microduplication, some of them have clinical phenotypes or are clinically affected.

Conclusion

Therefore, parents of such fetuses should be informed of the possibility of microdeletions or microduplications to mitigate the psychological burden, and medical consultation and assistance should be provided when communicating the results of the mid‐gestation screening.
A novel SPINK5 donor splice site variant in a child with Netherton syndrome
Authors: Mintoff Dillon , Borg Isabella , Vornweg Julia , Mercieca Liam , Merdzanic Rijad , Numrich Johannes , Aquilina Susan , Pace Nikolai Paul , Fischer Judith
Published: February 2021

Background

Netherton syndrome (NS) is a genodermatosis caused by loss‐of‐function mutations in SPINK5, resulting in aberrant LEKTI expression.

Method

Next‐generation sequencing of SPINK5 (NM_001127698.1) was carried out and functional studies were performed by immunofluorescence microscopy of a lesional skin biopsy using anti‐LEKTI antibodies.

Results

We describe a novel SPINK5 likely pathogenic donor splice site variant (NM_001127698.1:c.2015+5G>A) in a patient with NS and confirm its functional significance by demonstrating complete loss of LEKTI expression in lesional skin by immunofluorescence analysis.

Conclusion

The 2015+5G>A is a novel, likely pathogenic variant in NS. Herein we review and assimilate documented SPINK5 pathogenic variants and discuss possible genotype–phenotype associations in NS.
On an initial value problem for time fractional pseudo‐parabolic equation with Caputo derivative
Authors: Luc Nguyen Hoang , Jafari Hossein , Kumam Poom , Tuan Nguyen Huy
Published: February 2021

In this paper, we consider a pseudo‐parabolic equation with the Caputo fractional derivative. We study the existence and uniqueness of a class of mild solutions of these equations. For a nonlinear problem, we first investigate the global solution under the initial data u0 ∈ L2. In the case of initial data u0 ∈ Lq,  q ≠ 2, we obtain the local existence result. Our main tool here is using fundamental tools, namely, Banach fixed point theorem and Sobolev embeddings. In addition, we give an example to illustrate the effectiveness of the method has been proposed.
On calculation of the pitch and angle of pitch of a closed ruled surface of dimension (k + 1) using a rotation minimizing frame in Euclidean space ℝn
Authors: Keskin Özgür , Altin Ayşe , Ekmekci Faik Nejat , Yayli Yusuf
Published: February 2021

In this paper, first, the pitch and the angle of pitch of a closed ruled surface of dimension (k + 1) are calculated according to a rotation minimizing frame in Euclidean space
. To calculate this pitch and this angle of pitch of the closed ruled surface of dimension (k + 1), three different ruled surfaces are taken according to the rotation minimizing frame. Therefore, for these three different ruled surfaces, three different situations are found. Second, by taking any curve in four‐dimensional Euclidean space, the closed ruled surface of this curve, its orthogonal trajectory, the pitch, and the angle of pitch of this closed ruled surface are obtained according to the rotation minimizing frame. Finally, the pitch and the angle of pitch of the closed ruled surface of dimension (k + 1) are generalized to n‐dimensional Euclidean space with the help of the rotation minimizing frame.
An accelerated hybrid projection method with a self‐adaptive step‐size sequence for solving split common fixed point problems
Authors: Zhou Zheng , Tan Bing , Li Songxiao
Published: February 2021

This paper attempts to solve the split common fixed point problem for demicontractive mappings. We give an accelerated hybrid projection algorithm that combines the hybrid projection method and the inertial technique. The strong convergence theorem of this algorithm is obtained under mild conditions by a self‐adaptive step‐size sequence, which does not need prior knowledge of the operator norm. Some numerical experiments in infinite‐dimensional Hilbert spaces are provided to illustrate the reliability and robustness of the algorithm and also to compare it with existing ones.
The Metabolism and Potential Bioactivity of Chlorophyll and Metallo‐chlorophyll Derivatives in the Gastrointestinal Tract
Authors: Zhong Siqiong , Bird Amanda , Kopec Rachel E.
Published: February 2021

Chlorophyll is the vivid chromophore which imparts the green color to plant leaves, and is consumed by humans through green vegetables. The basic porphyrin structure of chlorophyll binds magnesium in plants, but can bind different divalent metals (e.g., copper, zinc, iron) facilitated by food processing techniques and/or chemical synthesis. This review covers the known elements of chlorophyll and metallo‐chlorophyll absorption, distribution, metabolism, excretion in vitro and in vivo. The review discusses what is understood about the ability of these novel metallo‐chlorophyll derivatives to deliver essential metals. This review also detail chlorophyll and metallo‐chlorophyll toxin binding properties which largely occur during digestion, focusing on toxins including dioxins, heterocyclic aromatic amines, polyaromatic hydrocarbons, and aflatoxin. Finally, the article highlights the gaps in the understanding of the metabolism and metal and toxin‐binding bioactivity of this family of molecules.
Is There a Carcinogenic Risk Attached to Vitamin B12 Deficient Diets and What Should We Do About It? Reviewing the Facts
Authors: Loedin Alexandra K. , Speijer Dave
Published: February 2021

The number of individuals partaking in veganism has increased sharply in the last decade. Therefore, it is critical to look at the implications of vegan diets for public health. Although there are multiple health benefits of a vegan diet, studies have also linked the diet with deficiencies in various micronutrients. This study focuses on vitamin B12, because of its critical role in DNA synthesis and methylation. In light of these connections, a critical review of recent scientific literature is conducted to understand the effects of a B12 deficient diet on the genome and epigenome, and whether it can give rise to cancer. It is observed that a B12 deficiency leads to increased uracil misincorporation, leading to impaired DNA synthesis and genomic instability. The deficiency also leads to global hypomethylation of DNA, a hallmark of early carcinogenesis. The findings of this study highlight the need for increased awareness among vegans to ensure adequate B12 intake through supplementation or consumption of fortified products as a preventative measure. Additionally, the biofortification of staple crops and an improved version of fermented products with increased B12 content can be developed when inadequate intake seems otherwise inevitable.
Strategic method of determining parameter values in frequency modulated continuous wave radar for low noise floor over middle‐long range
Authors: Park Junhyeong , Jung Dae‐Hwan , Park Seong‐Ook
Published: February 2021

Heterodyne architecture has been frequently chosen to resolve the problem of dc offset in frequency modulated continuous wave (FMCW) radar. However, heterodyne FMCW radars use different local oscillators, resulting in uncorrelated phase noise (UPN) in beat signals. Therefore, the inherent leakage signal in the heterodyne FMCW radar also has UPN and raises the noise floor in the power spectrum. In this letter, we propose a strategic decision method for parameter values in the heterodyne FMCW radar to achieve a low noise floor over the middle‐long range. In addition, we experimentally discover the relation between the UPN and the processing gain for the first time. Based on this relation, we devise an exact formula for the degree of improvement achieved due to the proposed strategic decision method. Experimental results confirm the devised formula and show that the proposed method significantly reduces the noise floor over the middle‐long range.
End‐to‐end domain knowledge‐assisted automatic diagnosis of idiopathic pulmonary fibrosis (IPF) using computed tomography (CT)
Authors: Yu Wenxi , Zhou Hua , Goldin Jonathan G. , Wong Weng Kee , Kim Grace Hyun J.
Published: February 2021

Purpose

Domain knowledge (DK) acquired from prior studies is important for medical diagnosis. This paper leverages the population‐level DK using an optimality design criterion to train a deep learning model in an end‐to‐end manner. In this study, the problem of interest is at the patient level to diagnose a subject with idiopathic pulmonary fibrosis (IPF) among subjects with interstitial lung disease (ILD) using a computed tomography (CT). IPF diagnosis is a complicated process with multidisciplinary discussion with experts and is subject to interobserver variability, even for experienced radiologists. To this end, we propose a new statistical method to construct a time/memory‐efficient IPF diagnosis model using axial chest CT and DK, along with an optimality design criterion via a DK‐enhanced loss function of deep learning.

Methods

Four state‐of‐the‐art two‐dimensional convolutional neural network (2D‐CNN) architectures (MobileNet, VGG16, ResNet‐50, and DenseNet‐121) and one baseline 2D‐CNN are implemented to automatically diagnose IPF among ILD patients. Axial lung CT images are retrospectively acquired from 389 IPF patients and 700 non‐IPF ILD patients in five multicenter clinical trials. To enrich the sample size and boost model performance, we sample 20 three‐slice samples (triplets) from each CT scan, where these three slices are randomly selected from the top, middle, and bottom of both lungs respectively. Model performance is evaluated using a fivefold cross‐validation, where each fold was stratified using a fixed proportion of IPF vs non‐IPF.

Results

Using DK‐enhanced loss function increases the model performance of the baseline CNN model from 0.77 to 0.89 in terms of study‐wise accuracy. Four other well‐developed models reach satisfactory model performance with an overall accuracy >0.95 but the benefits brought on by the DK‐enhanced loss function is not noticeable.

Conclusions

We believe this is the first attempt that (a) uses population‐level DK with an optimal design criterion to train deep learning‐based diagnostic models in an end‐to‐end manner and (b) focuses on patient‐level IPF diagnosis. Further evaluation of using population‐level DK on prospective studies is warranted and is underway.
Joint calibrationless reconstruction of highly undersampled multicontrast MR datasets using a low‐rank Hankel tensor completion framework
Authors: Yi Zheyuan , Liu Yilong , Zhao Yujiao , Xiao Linfang , Leong Alex T. L. , Feng Yanqiu , Chen Fei , Wu Ed X.
Published: February 2021

Purpose

To jointly reconstruct highly undersampled multicontrast two‐dimensional (2D) datasets through a low‐rank Hankel tensor completion framework.

Methods

A multicontrast Hankel tensor completion (MC‐HTC) framework is proposed to exploit the shareable information in multicontrast datasets with respect to their highly correlated image structure, common spatial support, and shared coil sensitivity for joint reconstruction. This is achieved by first organizing multicontrast k‐space datasets into a single block‐wise Hankel tensor. Subsequent low‐rank tensor approximation via higher‐order singular value decomposition (HOSVD) uses the image structural correlation by considering different contrasts as virtual channels. Meanwhile, the HOSVD imposes common spatial support and shared coil sensitivity by treating data from different contrasts as from additional k‐space kernels. The missing k‐space data are then recovered by iteratively performing such low‐rank approximation and enforcing data consistency. This joint reconstruction framework was evaluated using multicontrast multichannel 2D human brain datasets (T1‐weighted, T2‐weighted, fluid‐attenuated inversion recovery, and T1‐weighted‐inversion recovery) of identical image geometry with random and uniform undersampling schemes.

Results

The proposed method offered high acceleration, exhibiting significantly less residual errors when compared with both single‐contrast SAKE (simultaneous autocalibrating and k‐space estimation) and multicontrast J‐LORAKS (joint parallel‐imaging–low‐rank matrix modeling of local k‐space neighborhoods) low‐rank reconstruction. Furthermore, the MC‐HTC framework was applied uniquely to Cartesian uniform undersampling by incorporating a novel complementary k‐space sampling strategy where the phase‐encoding direction among different contrasts is orthogonally alternated.

Conclusion

The proposed MC‐HTC approach presents an effective tensor completion framework to jointly reconstruct highly undersampled multicontrast 2D datasets without coil‐sensitivity calibration.
Comparison between surface electrodes and ultrasound monitoring to measure TMS evoked muscle contraction
Authors: Kaczmarczyk Isabella , Rawji Vishal , Rothwell John C. , Hodson‐Tole Emma , Sharma Nikhil
Published: February 2021

Introduction

Transcranial magnetic stimulation (TMS) is widely used to explore cortical physiology in health and disease. Surface electromyography (sEMG) is appropriate for superficial muscles, but cannot be applied easily to less accessible muscles. Muscle ultrasound (mUS) may provide an elegant solution to this problem, but fundamental questions remain. We explore the relationship between TMS evoked muscle potentials and TMS evoked muscle contractions measured with mUS.

Methods

In 10 participants, we performed a TMS recruitment curve, simultaneously measuring motor evoked potentials (MEPs) and mUS in biceps (BI), first dorsal interosseous (FDI), tibialis anterior (TA), and the tongue (TO).

Results

Resting motor threshold (RMT) measurements and recruitment curves were found to be consistent across sEMG and mUS.

Discussion

This work supports the use of TMS‐US to study less accessible muscles. The implications are broad but could include the study of a new range of muscles in disorders such as amyotrophic lateral sclerosis.
Performance of Subyearling Fall Chinook Salmon Tagged with 8-, 9-, and 12-mm Passive Integrated Transponder Tags in the Snake River
Authors: Tiffan Kenneth F. , Rhodes Tobyn N. , Bickford Brad K. , Lebeda Dalton D. , Connor William P. , Mullins Frank L.
Published: February 2021

Inferences based on tagged individuals from a population are limited in part by the minimum size of fish that can be tagged. Smaller tags allow a greater proportion of a population to be represented by tagging and should reduce potential tag effects on fish performance. We evaluated different performance metrics of juvenile fall Chinook Salmon Oncorhynchus tshawytscha tagged with 8-, 9-, and 12-mm PIT tags in the Snake River. We did not find evidence that posttagging mortality of 45–49-mm-FL fish tagged with 8-mm tags was higher than the posttagging mortality of larger fish tagged with 9- and 12-mm tags. The incisions of fish tagged with 8-mm tags using 14-guage needles healed faster than those of fish tagged with larger tags using 12-guage needles. For individuals that received 8-mm tags, growth in length and mass was higher for 45–49-mm fish than for 50–59-mm fish and 60-mm and larger fish. Growth of the larger size-classes (50–59 and ≥60 mm) was also generally higher for those tagged with 8-mm tags compared to those tagged with 9- and 12-mm tags, respectively. There were no strong relationships between tag burden (i.e., tag weight expressed as a percentage of fish weight) at the time of tagging and growth metrics for any tag size or fish size-class. Releases made to compare the detection efficiency of the three tag types in the juvenile fish bypass at Lower Granite Dam, Washington, showed that 99–100% of all fish were detected. Survival of fish from rearing areas to Lower Granite Dam generally increased with fish size and varied by year, but there was no strong evidence of a tag size effect. The 8-mm PIT tag allowed us to represent a larger portion (i.e., 6.2–24.1%) of the subyearling fall Chinook Salmon population in the Snake River without compromising fish performance or detectability at the dam.
A constitutive model for the accumulated strain of unsaturated soil under high‐cycle traffic loading
Authors: Cao Zhigang , Chen Jingyu , Alonso Eduardo E. , Tarragona Anna Ramon , Cai Yuanqiang , Gu Chuan , Zhang Qi
Published: February 2021

The road base is normally situated above the water table and thus in unsaturated state. Experimental results show that the accumulated strains of the unsaturated road base aggregate under high‐cycle traffic loads are significantly influenced by the matric suction. To predict the accumulated strain of unsaturated road base aggregate under high‐cycle traffic loads, a constitutive model was developed based on the Barcelona Basic Model (BBM) and the shakedown concept. In this model, the shakedown and plastic creep boundaries of the aggregate under cyclic loads were supposed to exist and to have the same shape as the “static” yield surface in BBM. The strain accumulation rates were described as an exponential function of the distance between the peak cyclic stress point and the conjugated point at the current cyclic yield surface. An explicit calculation methodology was adopted to avoid large calculation errors and to improve the calculation efficiency of the model. Comparison between model predictions and testing results proved the accuracy of the proposed model, which can be used as a basic model to predict the long‐term deformation of unsaturated road base aggregate under high‐cycle traffic loads.
A privacy‐focused approach for anomaly detection in IoT networks
Authors: Martins Pedro , Reis André B. , Salvador Paulo , Sargento Susana
Published: February 2021

IoT devices present a series of liabilities to administrators that aim for fully secure networks. Owing to their heterogeneity and limited processing power, administrators often implement monitoring mechanisms to prevent unauthorized use of resources and data exfiltration. However, most approaches allow for easy discrimination of private behavioral patterns of its users or nodes by their MAC or IP addresses. Inferring data exchange patterns at the physical layer is a more complex task, as a single signal power indicator may correspond to a mixture of simultaneous data transmissions. This article proposes privacy‐focused mechanisms by resorting to physical layer data analysis and one‐class classification models to perform anomaly detection in IoT networks. We present a full processing pipeline that considers the signal that identifies and models patterns on the channel activity and silence periods. We train our models with data captured from interactions with an Amazon Echo with devices generating background noise and test them against a similar scenario with a tampered network node periodically uploading data. Our data show that the best performing model, kernel density estimation, is able to detect anomalies with a 99% precision rate, even surpassing the tested neural networks approaches. We also propose a framework that aims to deploy validated models into production IoT environments. We designed an end‐to‐end data flow that autonomously extracts data and classifies them at the anomaly detection server. The envisioned components were designed to be horizontally scaled for a myriad of data streams and machine learning algorithms working in parallel.
A real‐time optimization algorithm for the fixed‐stress splitting scheme
Authors: Honório Hermínio T. , Martins Bruno , Maliska Clovis R.
Published: February 2021

The efficient solution of the systems of equations arising from coupled consolidation problems is a matter of concern worldwide. The fixed‐stress splitting scheme is an effective approach for solving these equations either in a sequential manner or as a preconditioner for a fully coupled approach. Recent studies show that it is possible to improve the convergence rate of the fixed‐stress approach by choosing a proper tuning parameter. In this work, we present an optimization algorithm that dynamically searches for the optimal tuning parameter for each time step of the simulation, hence the denomination of real‐time optimization. The numerical examples show that the optimal tuning parameter indeed can change during the simulation, which highlights the importance of the dynamic search provided by the optimization algorithm. In some situations, the optimized fixed‐stress algorithm proposed in this work is able to reduce the total number of iterations by up to 70% compared to the non‐optimized version.
Thermo‐elastic topology optimization with stress and temperature constraints
Authors: Meng Qingxuan , Xu Bin , Wang Chao , Zhao Lei
Published: February 2021

A thermo‐elastic topology optimization with stress and temperature constraints is proposed to attack the complex multiphysics problem in this paper. Based on the rational approximation of material properties (RAMP), the coupled equations of mechanic and temperature field are solved. Two optimization problems, volume minimization with temperature and stress constraints, and traditional compliance minimization with volume and temperature constraints, are discussed for comparison. The stress stabilizing control scheme (SSCS) combined with global stress measure is presented to tackle highly nonlinear and local nature of stress with thermal expansion in varying temperature field. The adjoint method is applied to achieve the sensitivity of multiphysics field and the density function is updated utilizing the method of moving asymptotes (MMA). Representative examples are investigated to demonstrate the effectiveness and utility of the proposed method. Clear topology and stable iterative process can be obtained for complex coupled problem by means of the SSCS. Meanwhile, the topology with stress and temperature constraints has obvious sensitivity to even subtle change in temperature. The optimization design considering several stress constraints under multithermal conditions can work well in different temperature ranges.