bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of the technology for laying corrugated pipes for creating culverts under roads
Authors: Serebrennikov A A , Serebrennikov D A
Published: March 2021

The widespread use of polypropylene corrugated pipes for free-flow culverts requires that the construction technology ensure compliance with their physical and mechanical characteristics during their service. The use of polypropylene corrugated pipes for culverts in road construction poses greater demands on them. The paper considers the behavior of a buried pipe in interaction with the surrounding soil. The contradictions in the current building codes and regulations have been revealed. It has been proven that for polypropylene corrugated pipes, the resistance of the backfill soil, depending on the degree of compaction, is an essential factor in ensuring the long-term stability of the circular cross-section of the pipe. Theoretical calculations have confirmed that, depending on the backfill depth, the relative deformation of polypropylene corrugated pipes may exceed the maximum permissible values. An engineering solution has been proposed that provides an increase in the rigidity of the pipe bearing reaction under compressive forces and a decrease in the load from vehicles.
Quality of construction materials as an indicator of the design of railway transport facilities in Russia
Authors: Korchagin A , Zaycev D
Published: March 2021

The purpose of the research is to assess the global quality of project design documentation for capital construction at the preliminary stage of investment projects in the context of the properties and qualities of applied construction materials. The problem of the assessment of the quality of construction and finishing materials in the subdivisions of Russian Railways, the largest Russian company, raises fundamental issues of regulatory and methodological support during the choice of engineering solutions and reasonability grounds of investments in the construction and reconstruction of transport infrastructure facilities. According to the formal indicators for the assessment of the properties of materials in the company, the authors used a method based on a separate analysis of the regulatory and methodological support of the construction preparation process. The main quality criterion was adopted in the form of deviations in documentation by the internal examination service of the company projects due to the unreliability in the determination of the physical properties of material resources. The main tool to influence the design process is the formalization of requirements for accounting construction materials, especially innovative ones, in project design documentation. These requirements are reflected in the proposed methodology for the generation of documentation at the early stages of investment project. A retrospective analysis of the verification results of infrastructure projects in the company showed that after the introduction of uniform requirements for the applied materials and the introduction of the basic provisions of materials science in the methodological documents, a positive trend has occurred during internal verification. The decrease in the number of incorrectly determined values of the need for construction materials indicate that cost certification has become more explicit and accessible to developers. It is proved that the tool for the management of the quality of construction materials by specifying the structure of documents justifying the main design decisions is the most effective. The idea is confirmed that the greatest responsibility for the efficiency of the applied material resources falls on the early stages of project development. The efforts made by the Company in this direction lead to positive changes.
Recursive method in assigning materials in construction projects
Authors: Zaycev D , Korchagin A , Solovev V , Guzhov S
Published: March 2021

The paper considers the issues of improvement of the evaluation methods of new materials in construction. The features of regulatory control over the use of resources in Russia are characterized by the presence of a dual approach to choosing a regulatory framework, which in some cases leads to incorrect choice of materials. Engineering solutions during design are closely dependent on the cost parameters laid down in the regulatory and methodological framework. As a result, the problem of improving norms and methodologies is relevant for highly significant regulation. The property of recursivity of design solutions, normative support of construction and quantitative parameters of construction materials used in the design of structures is noted. The mutual influence of the process of developing standards and their further application in projects made it possible to use the recurrent formula tool for pre-design analysis of the possibility of using certain materials. The method allows performing a separate analysis of the possibility of application in projects for different materials, which can be useful when introducing new materials. On the basis of the proposed calculation method, conclusions on the need to improve the process of developing standards were drawn. The main problems of regulating the consumption of construction resources at the present stage are formulated. The need to design new standards based on the practice of applying new materials in construction projects was noted. The paper suggests the mechanisms to solve the problem of improving the reliability of determining a set of construction materials when designing construction works in transport construction, which would reduce the time for developing new and updating the existing standards. The assessment of the applicability of construction materials should not remain within the framework of subjective decisions of the engineering practice; on the contrary, it should improve the calculation methods to justify the applicability of materials.
Effect of calcination temperature on physicochemical and antimicrobial properties of green synthesised ZnO/C/Ca nanocomposites using Calotropis gigantea leaves
Authors: Govindasamy G Ambarasan , S. M. N. Mydin Rabiatul Basria , Sreekantan Srimala , Harun Nor Hazliana
Published: March 2021

In the present study, green synthesised ZnO nanoparticles using Calotropis gigantea (C. gigantea) leaf extract which were produced at different calcination temperatures (i.e. 400 °C and 500 °C) were evaluated against skin ulcer pathogens since no study is reviewed before. The results from x-ray powder diffraction and energy-dispersive spectroscopy confirmed the presence of ZnO nanoparticles along with natural compounds from medicinal plant (i.e. Ca and C). The capping and stabilising phytochemical agents of C. gigantea leaves such as phenol and carbonyl were identified through UV–Vis and FTIR. Scanning electron microscopy and transmission electron microscopy revealed that increasing the calcination temperature altered the size and shape of the prepared samples. ZnO nanoparticles which were prepared at calcination temperatures of 400 °C and 500 °C were quasi-spherical and irregular rod in shape. The minimum inhibitory and the minimum bactericidal concentrations of ZnO-400C were 0.625 and 1.25 mg ml−1, whereas those of ZnO-500C were 1.25 and 20 mg ml−1 against Staphylococcus aureus (S. aureus). Remarkably, the ZnO-400C revealed excellent bactericidal activity against skin ulcer pathogens, with MBC ranging from 0.3125 mg ml−1 to 2.5 mg ml−1. The time-kill kinetics assay demonstrated that 1.25 mg ml−1 ZnO-400C captured a significant reduction of ≤2.5 log10 in the S. aureus population after 6 h of incubation. ZnO-400C sample significantly reduced the biofilm formed by S. aureus which might be associated to the presence of Zn2+, Ca2+ and reactive oxygen species (ROS). A strong interaction and exfoliation between natural calcium and carbon from C. gigantea and ZnO nanoparticles offered new insights to inactivate skin ulcer pathogens synergically.
Electrical and magnetic properties of La0.7Ca0.3MnO3 nanoparticle prepared by reactive milling method
Authors: Thi Dung Nguyen , Van Dang Nguyen , Thanh Tran Dang
Published: March 2021

La0.7Ca0.3MnO3 nanoparticle in an orthorhombic structure with space group of Pnma was prepared by a combination of the reactive milling method and annealing at 900 °C for 1 h in air. The mean crystal size determined through the powder x-ray diffraction data is 18 ± 2 nm. Based on the dependences of the resistivity and the magnetisation on temperature and applied magnetic field, the electrical-magnetic properties, the magnetoresistance and the magnetocaloric effects have been investigated. It shows La0.7Ca0.3MnO3 nanoparticle undergoes a metal-insulator and a ferromagnetic-paramagnetic phase transitions at T
MI = 252 K and T
C = 253 K, respectively. The temperature dependences of resistivity of material in the absence and presence of 4 kOe in a range of 30–300 K were fitted to the phase segregation model. The magnetoresistance and the magnetocaloric effects related to the double-exchange interactions taking place around T
MI and T
C were observed, corresponding to the values of the magnetoresistance MR = 9.29% and the maximum magnetic entropy change ∣ΔS
max∣ = 0.18 J/kg.K under an applied magnetic field of 4 kOe. Besides, the low field magnetoresistance value at low temperature region and the change of the specific heat of La0.7Ca0.3MnO3 nanoparticle have also been concerned.
Microstructure and mechanical behaviour of Ti-Cu foams synthesized via powder metallurgy technique
Authors: Sharma Abhishek , Mishra Pushyamitra
Published: March 2021

In the present study titanium based copper alloy foams were synthesized using acrawax as a space holder through powder metallurgy route. The effects of distinct pore size range and Cu content on the microstructural features, density, compressive and flexural behaviour was investigated. Results show that the amount of microporosity generated was more in case of foams with coarser pores than finer ones and also it increased with increase in Cu content. The presence of fine pores and lower amount of Cu led to generation of minimal amount of microporosity; resulting into greater relative density of Ti-Cu foams. The plastic collapse stress, plateau stress and bending strength of Ti-Cu foams decreased while densification strain increased with increase in Cu content. The maximum value of plastic collapse stress is reported for Ti-3Cu foam with fine pores. The plateau strength and bending strength of Ti-3Cu foam with fine pores was found to be higher than that of Pure Ti foams and was found to be the most optimized in terms of the characteristic features. The higher values of relative density, plateau and bending strength of Ti-3Cu foams makes them more preferable over pure Ti foams for implants applications.
Reductions in NO2 concentrations in Seoul, South Korea detected from space and ground-based monitors prior to and during the COVID-19 pandemic
Authors: Seo Seunghwan , Kim Si-Wan , Kim Kyoung-Min , Lamsal Lok N , Jin Hyungah
Published: March 2021

Nitrogen oxides detected in urban regions are primarily emitted by transportation methods and are crucial precursors for air pollutants and climate forcers such as ozone and fine particulate matter. We investigate the trends of nitrogen dioxide (NO2) obtained from a satellite instrument and surface monitors over the megacity, Seoul, South Korea, from 2005 to 2019. Both satellite Ozone Monitoring Instrument NO2 and surface in situ concentrations decreased by up to 30% between 2015 and 2019 while significant trends were not observed between 2005 and 2015. Further analysis shows the continual reduction of NO2 concentrations prior to and during the COVID-19 pandemic in 2020. This study highlights the efficacy of South Korean pollution control policies targeting vehicular emissions. However, this study also found inconsistencies between trends observed in the official bottom-up emission inventory and data collected from space and surface sites. Further research will be urgently needed to understand the causes for the discrepancies.
Contribution of the intensity of intraseasonal oscillation to the interannual variation of tropical cyclogenesis over the western North Pacific
Authors: Cao Xi , Wu Renguang , Xu Jing , Feng Juan , Zhang Xiping , Dai Yifeng , Liu Yuyun
Published: March 2021

The present study compares the contributions of seasonal, intraseasonal, and synoptic variations of environmental factors, i.e., mid-level moisture, vertical instability, and lower-level relative vorticity, to the interannual variation of tropical cyclone (TC) genesis over the western North Pacific (WNP) during July-August-September-October (JASO) of 1979–2015. It is found that the TC genesis frequency has a significant positive correlation with the intensity of intraseasonal oscillation, but a weak correlation with the intensity of synoptic variation of environmental factors during JASO in the WNP. In addition, the intraseasonal components of convection and lower-level vorticity at the location of TC genesis have a larger contribution than the interannual and synoptic components to the differences between more and less TC years over the WNP. The present results indicate that the intensity of intraseasonal oscillation of environmental factors has an important effect on the interannual variation of the TC genesis frequency over the WNP. This study enhances our understanding of the impacts of intraseasonal oscillation on the interannual variation of the WNP TC activity and indicates that the intensity of intraseasonal oscillation has the potential to be used in the seasonal prediction of the WNP TC genesis.
A self-powered glucose sensor based on BioCapacitor principle with micro-sized enzyme anode employing direct electron transfer type FADGDH
Authors: Lee Inyoung , Okuda-Shimazaki Junko , Tsugawa Wakako , Ikebukuro Kazunori , Sode Koji
Published: March 2021

Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin; consequently, blood glucose levels increase to become abnormally high. Accordingly, the primary treatment of diabetes is to control glycemic levels continuously. To continuously control glycemic levels, several medical devices have been developed to monitor blood glucose levels, represented by sensors and monitors for the self-monitoring of blood glucose. The ultimate goal for those engaged in research to develop medical devices is to develop implantable biodevices, namely self-powered autonomously operated artificial pancreas systems. One of the most challenging issues in realizing an implantable artificial pancreas is the long-term continuous supply of electricity, which is currently dependent on rechargeable batteries, requiring periodical replacement. In this work, we report the development of a direct electron transfer type enzyme-based miniaturized self-powered glucose sensor based on the BioCapacitor principle with a micro-sized enzyme anode area (0.15 mm × 0.75 mm), which has only 0.1 mm2 of electrode surface. As a result, a BioCapacitor utilizing a biofuel cell with a micro-sized enzyme anode was operated by self-power. In addition, the glucose concentration was detected within the range from 13 mM to 100 mM based on the frequency of charge/discharge cycles of the BioCapacitor. Although further improvement of the current density of the micro-sized anode is necessary to monitor a glucose concentration range lower than 13 mM, this self-powered glucose sensor with a micro-sized electrode based on the BioCapacitor principle was operated continuously for 6.6 h at 37 °C in 100 mM potassium phosphate buffer (pH 7.0). Our success indicates the potential to realize self-powered, autonomous, and implantable sensing modules for bio devices such as glucose-sensing systems for an artificial pancreas.
Kinematic design of linkage-based haptic interfaces for medical applications: a review
Authors: Torabi Ali , Nazari Ali A , Conrad-Baldwin Everly , Zareinia Kourosh , Tavakoli Mahdi
Published: March 2021

A haptic interface recreates haptic feedback from virtual environments or haptic teleoperation systems that engages the user’s sense of touch. High-fidelity haptic feedback is critical to the safety and success of any interaction with human beings. Such interactions can be seen in haptic systems utilized in medical fields, such as for surgical training, robotic tele-surgery, and tele-rehabilitation, which require appropriate haptic interface design and control. In order to recreate high-fidelity soft and stiff contact experiences for the user in the intended application, different designs strike different trade-offs between the desirable characteristics of an interface, such as back-drivability, low apparent inertia and low friction for the best perception of small reflected forces, large intrinsic stiffness and force feedback capability for the best perception of large reflected forces, a large-enough workspace for exploring the remote or virtual environment, and the uniformity of haptic feedback and its adequate sensitivity over the workspace. Meeting all of the requirements simultaneously is impossible, and different application-driven compromises need to be made. This paper reviews how various kinematic designs have helped address these trade-offs in desired specifications. First, we investigate the required characteristics of linkage-based haptic interfaces and inevitable trade-offs between them. Then, we study the state of the art in the kinematic design of haptic interfaces and their advantages and limitations. In all sections, we consider the applications of the intended haptic interfaces in medical scenarios. Non-linkage-based haptic interfaces are also shortly discussed to show the broad range of haptic technologies in the area. The potentials of kinematic redundancy to address the design trade-offs are introduced. Current challenges and future directions of haptic interface designs for medical applications are shortly discussed, which is finally followed by the conclusion.
Effect of pH on the Quantification of Common Chemistry Analytes in Body Fluid Specimens Using the Roche cobas Analyzer for Clinical Diagnostic Testing
Authors: Nandakumar Vijayalakshmi , Dolan Christopher T , Baumann Nikola A , Block Darci R
Published: March 2021

Objectives

To determine the influence of pH on recovery of analytes in body fluids (BFs), investigate the mechanism of pH interference, measure the frequency of abnormal-pH BFs received, and compare pH measured by meter and paper.

Methods

We performed pH titration in residual BFs. A low-pH BF was spiked and neutralized to investigate pH interference. We measured analytes on a Roche cobas c501 analyzer (Roche Diagnostics) and calculated the percent recovery. Measurement of pH using a meter and paper was conducted on 122 BF samples received in the laboratory.

Results

Enzyme activity in BFs was unaffected when pH = 7.4-8.5 lactate dehydrogenase, pH = 7.3-10.2 amylase, pH = 6.0-9.9 lipase, and pH = 1.3-11.7 all other analytes. BFs had mean (range) pH of 8.0 (5.1-8.9), with a mean (range) difference (paper ‒ meter) of ‒0.4 (‒0.6 to 1.1).

Conclusions

Irreversible loss of enzyme activity occurs in BFs at low pH. Few clinical BFs have pH < 7.0, but laboratories should incorporate pH measurement in BF workflows.
Queueing theory model of Krebs cycle
Authors: Kloska Sylwester , Pałczyński Krzysztof , Marciniak Tomasz , Talaśka Tomasz , Nitz Marissa , Wysocki Beata J , Davis Paul , Wysocki Tadeusz A
Published: March 2021

Motivation

Queueing theory can be effective in simulating biochemical reactions taking place in living cells, and the article paves a step toward development of a comprehensive model of cell metabolism. Such a model could help to accelerate and reduce costs for developing and testing investigational drugs reducing number of laboratory animals needed to evaluate drugs.

Results

The article presents a Krebs cycle model based on queueing theory. The model allows for tracking of metabolites concentration changes in real time. To validate the model, a drug-induced inhibition affecting activity of enzymes involved in Krebs cycle was simulated and compared with available experimental data.

Availabilityand implementation

The source code is freely available for download at https://github.com/UTP-WTIiE/KrebsCycleUsingQueueingTheory, implemented in C# supported in Linux or MS Windows.

Supplementary information

Supplementary data are available at Bioinformatics online.
Nutrient provisioning of its host myrmecophytic tree by a temporary social parasite of a plant-ant
Authors: Dejean Alain , Petitclerc Frédéric , Azémar Frédéric , Rossi Vivien
Published: March 2021

One of the most advanced ant–plant mutualisms is represented by myrmecophytes sheltering colonies of some plant-ant species in hollow structures called domatia. In turn, the myrmecophytes benefit from biotic protection and sometimes nutrient provisioning (myrmecotrophy). Furthermore, over the course of evolution, some ant species have become social parasites of others. In this general context, we studied the relationship between its host trees and Azteca andreae (Dolichoderinae), a temporary social parasite of the plant-ant Azteca ovaticeps, and, as such, obligatorily associated with myrmecophytic Cecropia obtusa trees (Urticaceae). A first experiment showed that the δ15N values of the young leaves of Cecropia sheltering a mature A. andreae colony were very similar to those for trees sheltering Azteca alfari or A. ovaticeps, two typical Cecropia mutualists for which myrmecotrophy is known. In a second experiment, by injecting a 15N-labelled glycine solution into locusts given as prey to A. andreae colonies, we triggered an increase in δ15N in the young leaves of their host Cecropia. Thus, 15N passed from the prey to the host trees, explaining the outcomes of the first experiment. We discuss these results in light of the notion of ‘by-product benefits’.
Comparison of the urgent referral for suspected breast cancer process with patient age and a predictive multivariable model
Authors: Ramzi S , Cant P J
Published: March 2021

Background

The urgent 2-week wait referral for suspected breast cancer system (U2WW) in the UK prioritizes primary care referrals to one-stop breast clinics as ‘urgent’ or ‘choose and book’ (C&B). The aim of this study was to evaluate the accuracy of U2WW in discriminating cancer versus no cancer, and to consider alternative criteria.

Methods

Clinical features elicited in primary care and demographics of consecutive female patients in a specialist breast clinic were collated at the time of consultation from May 2008 to July 2017. U2WW was compared with patient age alone and a multivariable model in terms of accuracy and net cost for eight underlying cost–benefit assumptions.

Results

There were 7915 eligible referrals: 4877 urgent (61.6 per cent) and 3038 C&B (38.4 per cent) referrals. Breast cancer was diagnosed in 546 patients (6.9 per cent): 491 (10.1 per cent) in urgent and 55 (1.8 per cent) in C&B referrals (P < 0.001). The multivariable model summated the significant variables: age (odds ratio (OR) 1.07, 95 per cent c.i. 1.07 to 1.08), tumour (OR 4.85, 3.62 to 6.52), observed change (OR 1.73, 1.34 to 2.23), pain (OR 0.46, 0.35 to 0.61) and gravidity (OR 0.72, 0.54 to 0.95). The area under the curve was 0.651 for U2WW, 0.784 for age alone, and 0.824 for the multivariable model (P <0.001 for all comparisons). Considering the cost assumptions, age alone and the multivariable model were either more accurate than U2WW, or as accurate but less costly.

Conclusion

The U2WW is surpassed by patient age as a single referral criterion. A multivariable model based on demographics and simple clinical features outperformed both. The continued use of the U2WW needs to be reconsidered.
Huntington’s disease-specific mis-splicing unveils key effector genes and altered splicing factors
Authors: Elorza Ainara , Márquez Yamile , Cabrera Jorge R , Sánchez-Trincado José Luis , Santos-Galindo María , Hernández Ivó H , Picó Sara , Díaz-Hernández Juan I , García-Escudero Ramón , Irimia Manuel , Lucas José J
Published: March 2021

Correction of mis-splicing events is a growing therapeutic approach for neurological diseases such as spinal muscular atrophy or neuronal ceroid lipofuscinosis 7, which are caused by splicing-affecting mutations. Mis-spliced effector genes that do not harbour mutations are also good candidate therapeutic targets in diseases with more complex aetiologies such as cancer, autism, muscular dystrophies or neurodegenerative diseases. Next-generation RNA sequencing (RNA-seq) has boosted investigation of global mis-splicing in diseased tissue to identify such key pathogenic mis-spliced genes. Nevertheless, while analysis of tumour or dystrophic muscle biopsies can be informative on early stage pathogenic mis-splicing, for neurodegenerative diseases, these analyses are intrinsically hampered by neuronal loss and neuroinflammation in post-mortem brains. To infer splicing alterations relevant to Huntington’s disease pathogenesis, here we performed intersect-RNA-seq analyses of human post-mortem striatal tissue and of an early symptomatic mouse model in which neuronal loss and gliosis are not yet present. Together with a human/mouse parallel motif scan analysis, this approach allowed us to identify the shared mis-splicing signature triggered by the Huntington’s disease-causing mutation in both species and to infer upstream deregulated splicing factors. Moreover, we identified a plethora of downstream neurodegeneration-linked mis-spliced effector genes that—together with the deregulated splicing factors—become new possible therapeutic targets. In summary, here we report pathogenic global mis-splicing in Huntington’s disease striatum captured by our new intersect-RNA-seq approach that can be readily applied to other neurodegenerative diseases for which bona fide animal models are available.
Host versus cell-dependent effects of β-arrestin 1 expression in prostate tumorigenesis
Authors: Adekoya Timothy O , Smith Nikia , Thomas Ariel J , Lane Tonya S , Burnette Nija , Rivers Elizabeth J , Li Yahui , Chen Xiaoxin L , Richardson Ricardo M
Published: March 2021

Prostate cancer (PCa) constitutes a serious health challenge and remains one of the main causes of cancer-related death among men. The more aggressive form of the disease has been attributed to androgen independence, resulting in a lack of response to androgen deprivation therapy and sustained activation of other growth pathways. The scaffold proteins β-arrestin 1 and 2 (βarr1 and βarr2), which are known to mediate G protein-coupled receptor desensitization and internalization, were also shown to modulate prostate tumorigenesis. βarr1 is significantly overexpressed (>4-fold) in PCa cells relative to βarr2. In this study, we investigated the effect of βarr1 overexpression in PCa development and progression using the mouse and human PCa cell xenografts, and autochthonous transgenic adenocarcinoma of the mouse prostate (TRAMP) models deficient in β-arrestin depletion of βarr1 in TRAMP mice (TRAMP/βarr1−/−) increased PCa growth and decreased overall survival relative to control TRAMP or TRAMP/βarr2−/− animals. Prostate tissues from TRAMP/βarr1−/− tumors displayed an increase in androgen receptor (AR) expression, whereas overexpression of βarr1 in TRAMP-C1 (TRAMP-C1-βarr1-GFP) which derived from TRAMP decreased AR expression, cell proliferation and tumor growth in nude mice xenografts, relative to control TRAMP-C1-GFP. Knockdown of βarr1 expression in human MDA PCa 2b cells (MDA PCa 2b-βarr1−/−) also decreased AR expression cell proliferation and tumor growth relative to control (MDA PCa 2b-Sham) cells. Interestingly, both TRAMP-C1-βarr1-GFP and MDA PCa 2b-βarr1−/− xenografts showed a decrease in AKT phosphorylation but an increase in MAPK activation. Altogether, the data indicate that the effect of βarr1 in modulating AR signaling to regulate PCa aggressiveness is cell and host autonomous.
Microscale Physiological Events on the Human Cortical Surface
Authors: Paulk Angelique C , Yang Jimmy C , Cleary Daniel R , Soper Daniel J , Halgren Mila , O’Donnell Alexandra R , Lee Sang Heon , Ganji Mehran , Ro Yun Goo , Oh Hongseok , Hossain Lorraine , Lee Jihwan , Tchoe Youngbin , Rogers Nicholas , Kiliç Kivilcim , Ryu Sang Baek , Lee Seung Woo , Hermiz John , Gilja Vikash , Ulbert István , Fabó Daniel , Thesen Thomas , Doyle Werner K , Devinsky Orrin , Madsen Joseph R , Schomer Donald L , Eskandar Emad N , Lee Jong Woo , Maus Douglas , Devor Anna , Fried Shelley I , Jones Pamela S , Nahed Brian V , Ben-Haim Sharona , Bick Sarah K , Richardson Robert Mark , Raslan Ahmed M , Siler Dominic A , Cahill Daniel P , Williams Ziv M , Cosgrove G Rees , Dayeh Shadi A , Cash Sydney S
Published: March 2021

Despite ongoing advances in our understanding of local single-cellular and network-level activity of neuronal populations in the human brain, extraordinarily little is known about their “intermediate” microscale local circuit dynamics. Here, we utilized ultra-high-density microelectrode arrays and a rare opportunity to perform intracranial recordings across multiple cortical areas in human participants to discover three distinct classes of cortical activity that are not locked to ongoing natural brain rhythmic activity. The first included fast waveforms similar to extracellular single-unit activity. The other two types were discrete events with slower waveform dynamics and were found preferentially in upper cortical layers. These second and third types were also observed in rodents, nonhuman primates, and semi-chronic recordings from humans via laminar and Utah array microelectrodes. The rates of all three events were selectively modulated by auditory and electrical stimuli, pharmacological manipulation, and cold saline application and had small causal co-occurrences. These results suggest that the proper combination of high-resolution microelectrodes and analytic techniques can capture neuronal dynamics that lay between somatic action potentials and aggregate population activity. Understanding intermediate microscale dynamics in relation to single-cell and network dynamics may reveal important details about activity in the full cortical circuit.
Large-Scale Phenomic and Genomic Analysis of Brain Asymmetrical Skew
Authors: Kong Xiang-Zhen , Postema Merel , Schijven Dick , Castillo Amaia Carrión , Pepe Antonietta , Crivello Fabrice , Joliot Marc , Mazoyer Bernard , Fisher Simon E , Francks Clyde
Published: March 2021

The human cerebral hemispheres show a left–right asymmetrical torque pattern, which has been claimed to be absent in chimpanzees. The functional significance and developmental mechanisms are unknown. Here, we carried out the largest-ever analysis of global brain shape asymmetry in magnetic resonance imaging data. Three population datasets were used, UK Biobank (N = 39 678), Human Connectome Project (N = 1113), and BIL&GIN (N = 453). At the population level, there was an anterior and dorsal skew of the right hemisphere, relative to the left. Both skews were associated independently with handedness, and various regional gray and white matter metrics oppositely in the two hemispheres, as well as other variables related to cognitive functions, sociodemographic factors, and physical and mental health. The two skews showed single nucleotide polymorphisms-based heritabilities of 4–13%, but also substantial polygenicity in causal mixture model analysis, and no individually significant loci were found in genome-wide association studies for either skew. There was evidence for a significant genetic correlation between horizontal brain skew and autism, which requires future replication. These results provide the first large-scale description of population-average brain skews and their inter-individual variations, their replicable associations with handedness, and insights into biological and other factors which associate with human brain asymmetry.
A Tapered-pulsed Fidaxomicin Regimen Following Treatment in Patients With Multiple Clostridioides difficile Infection Recurrences
Authors: Skinner Andrew M , Tan Xing , Sirbu Benjamin D , Danziger Larry H , Gerding Dale N , Johnson Stuart
Published: March 2021

We treated 46 patients with multiple recurrent Clostridioides difficile infections (mrCDI) using a tapered-pulsed (T-P) fidaxomicin regimen, the majority of whom failed prior T-P vancomycin treatment. Sustained clinical response rates at 30 and 90 days were 74% (34/46) and 61% (28/46). T-P fidaxomicin shows promise for management of mrCDI.
Risk Factors Associated With Hospital Readmission and Costs for Pouchitis
Authors: Gonzalez Adalberto , Gupta Kapil , Rahman Asad Ur , Wadhwa Vaibhav , Shen Bo
Published: March 2021

Background

Pouchitis is the most common long-term complication in patients with restorative proctocolectomy and ileal pouch-anal anastomosis. This study aimed to identify readmission rates for pouchitis and risk factors associated with readmissions in an extensive national database.

Methods

We performed a retrospective analysis using the National Readmission Database to determine if patient demographics and clinical characteristics were predictors of hospital readmission within 30 days for adult patients (age >18 years) discharged with a principal diagnosis of pouchitis (ICD-9 code—569.71) from January 2013 to December 2013. Both univariable and multivariable analyses were performed to assess factors associated with 30-day readmission.

Results

A total of 1538 patients with pouchitis who were discharged alive were identified. 10.2% [95% confidence interval: 7.6, 12.7] of these were readmitted within 30 days of discharge. The average days to readmission were 18.6 ± 1.01. Multivariable analysis of risk factors associated with readmission showed older age as a protective factor for readmission [odds ratio (OR) = 0.88 (0.81, 0.96); P < 0.005]. Sex and the presence of permanent ileostomy were not associated with readmission in patients with pouchitis. The length of stay during readmissions was associated with postoperative wound infection [OR = 7.7 (94.0, 11.30); P < 0.001], ileus [OR = 4.5 (1.6, 7.4); P < 0.002], permanent ileostomy [OR = 3.7 (1.7, 5.7); P < 0.001], and long-term use of nonsteroidal anti-inflammatory drugs [OR = 3.2 (1.06, 5.3); P < 0.003].

Conclusions

Readmissions in pouchitis patients are frequent. Long-term use of nonsteroidal anti-inflammatory drugs, ileus, permanent ileostomy, and postoperative wound infection is associated with increased length of stay in readmissions.
Ethics in an Epidemic: Nine Issues to Consider
Authors: Raines James C
Published: March 2021

This article addresses nine ethical concerns facing school social workers during an epidemic and other emergency situations when they must rely on electronic communication platforms, such as Doxy.me, Skype, or Zoom. These issues of concern are use of appropriate terminology, client self-determination, technological competence, informed consent, confidentiality, boundary issues, social justice, record keeping, and professional self-care. The article combines research on the psychosocial effects of quarantine on students and their families and data about the effectiveness of telemental health. It provides legal expectations from the Family Educational Rights and Privacy Act as well as ethical guidance from the American Telemedicine Association and the National Association of Social Workers’ Code of Ethics to provide practical strategies about how to help students and their families during a time of prolonged stress. The article takes a strengths-based approach to crisis intervention by indicating both the advantages and the disadvantages of using electronic communication tools to provide continuity of care to clients.
Newly discovered 14th-century polyphony in Oxford
Authors: Mason Joseph W
Published: March 2021

Fragments transmitting 14th-century polyphony were discovered in Oxford in 2018. These fragments were from a large book of motets, copied and used in England in the 14th century. A reconstruction of the original source is provided and the notation of the source is analysed. A hypothesis that the book was copied or used in 14th-century Oxford is offered.
Lifecourse-varying structural stigma, minority stress reactions and mental health among sexual minority male migrants
Authors: van der Star Arjan , Bränström Richard , Pachankis John E
Published: March 2021

Background

Increasing evidence suggests that structural stigma (e.g. discriminatory laws, policies and population attitudes) can give rise to minority stress reactions (i.e. rejection sensitivity, internalized homophobia and identity concealment) to compromise sexual minorities’ mental health. Yet, many sexual minorities encounter divergent structural stigma climates over the life course, with potential implications for their experience of minority stress reactions and mental health. We take advantage of sexual minority male migrants’ lifecourse-varying exposures to structural stigma contexts to examine this possibility.

Methods

A sample of 247 sexual minority men who had migrated from 71 countries to the low-structural-stigma context of Sweden completed a survey regarding migration experiences, minority stress reactions and mental health. This survey was linked to objective indices of structural stigma present in these men’s countries of origin, diverse in terms of structural stigma.

Results

Country-of-origin structural stigma was significantly associated with poor mental health and this association was mediated by rejection sensitivity and internalized homophobia, but only among those who arrived to Sweden at an older age and more recently.

Conclusions

Prolonged exposure to high levels of structural stigma can give rise to stressful cognitive, affective and behavioural coping patterns to jeopardize sexual minority men’s mental health; yet, these consequences of structural stigma may wane with increased duration of exposure to more supportive structural contexts.
Airborne pollen concentrations and daily mortality from respiratory and cardiovascular causes
Authors: Jaakkola Jouni J K , Kiihamäki Simo-Pekka , Näyhä Simo , Ryti Niilo R I , Hugg Timo T , Jaakkola Maritta S
Published: March 2021

We conducted a time-series analysis of the relations between daily levels of allergenic pollen and mortality in the Helsinki Metropolitan Area with 153 378 deaths; 9742 from respiratory and 57 402 from cardiovascular causes. Daily (average) pollen counts of alder, birch, mugwort and grass were measured. In quasi-Poisson regression analysis, abundant alder pollen increased the risk of non-accidental deaths with an adjusted cumulative mortality rate ratio (acMRR) of 1.10 (95% CI 1.01–1.19) and of deaths from respiratory-diseases with acMRR of 1.78 (95% CI 1.19–2.65). Abundant mugwort pollen increased cardiovascular mortality (1.41, 1.02–1.95). These findings identify an important global public health problem.
Better air but not for all? Changes in second-hand smoke exposure at workplaces in 29 European countries over 10 years
Authors: Schneider Sven , Lunau Thorsten , Eikemo Terje A , Kotz Daniel , Bambra Clare , Kuntz Benjamin , Dragano Nico
Published: March 2021

Background

As the largest study of its kind to date, this article aims to describe the scope, trends over time, socio-demographic risk groups and the association with different progressive regulations relating to workplace second-hand smoke (SHS) exposure in 29 European countries during a period of high regulatory action.

Methods

Three waves of the European Working Conditions Surveys (2005, 2010 and 2015) were evaluated, including a total of 95 718 workers. The samples are representative for all employed residents of the 29 countries included. All interviews were conducted face-to-face at respondents’ homes (computer-assisted personal interviews). SHS exposure among the overall working population of 29 countries—including smokers—was examined. Workplace regimes were grouped corresponding to the sub-scale ‘workplace’ as used in the Tobacco Control Scale.

Results

Between 2005 and 2015, SHS exposure in the European countries declined from around 19.0% (95% CI 16.1–22.0) to 9.9% (8.3–11.5). High SHS-exposure was reported by workers with the lowest level of education [11.5% (9.7–13.2)], among high-skilled manual labourers [14.3% (12.1–16.4)] and among those without a standard employment contract [11.2% (9.3–13.1)]. The highest exposure was reported by workers in the food service industry [19.7% (16.8–22.6)]. Countries with less workplace-related smoking prevention regulations were found to have the highest overall levels of exposure.

Conclusion

This multinational series of cross-sectional surveys on the trends in passive smoking in the workplace have shown that countries with more comprehensive workplace smoking bans overall report lower levels of SHS exposure among their work force as compared with slow progressing countries.
Shannon entropy as a metric for conditional gene expression inNeurospora crassa
Authors: Ameri Abigail J , Lewis Zachary A
Published: March 2021

Neurospora crassa has been an important model organism for molecular biology and genetics for over 60 years. Neurospora crassa has a complex life cycle, with over 28 distinct cell types and is capable of transcriptional responses to many environmental conditions including nutrient availability, temperature, and light. To quantify variation in N. crassa gene expression, we analyzed public expression data from 97 conditions and calculated the Shannon Entropy value for Neurospora’s approximately 11,000 genes. Entropy values can be used to estimate the variability in expression for a single gene over a range of conditions and be used to classify individual genes as constitutive or condition-specific. Shannon entropy has previously been used measure the degree of tissue specificity of multicellular plant or animal genes. We use this metric here to measure variable gene expression in a microbe and provide this information as a resource for the N. crassa research community. Finally, we demonstrate the utility of this approach by using entropy values to identify genes with constitutive expression across a wide range of conditions and to identify genes that are activated exclusively during sexual development.
Integrated processing method for microseismic signal based on deep neural network
Authors: Zhang Hang , Ma Chunchi , Jiang Yupeng , Li Tianbin , Pazzi Veronica , Casagli Nicola
Published: March 2021

Denoising and onset time picking of signals are essential before extracting source information from collected seismic/microseismic data. We proposed an advanced deep dual-tasking network (DDTN) that integrates these two procedures sequentially to achieve the optimal performance. Two homo-structured encoder–decoder networks with specially designed structures and parameters are connected in series for handling the denoising and detection of microseismic signals. Based on the similarity of data types, the output of the denoising network will be imported into the detection network to obtain labels for the signal duration. The procedures of denoising and duration detection can be completed in an integrated way, where the denoised signals can improve the accuracy of onset time picking. Results show that the method has a good performance for the denoising of microseismic signals that contain various types and intensities of noise. Compared with existing methods, DDTN removes the noise with a minor waveform distortion. It is ideal for recovering the microseismic signal while maintaining a good capacity for onset time picking when the signal-to-noise ratio is low. Based on that, the second network can detect a more accurate duration of microseismic signals and thus obtain more accurate onset time. The method has great potential to be extended to the study of exploration seismology and earthquakes.
Phase-weighted slant stacking for surface wave dispersion measurement
Authors: Cheng Feng , Xia Jianghai , Zhang Kai , Zhou Changjiang , Ajo-Franklin Jonathan B
Published: March 2021

Surface wave retrieval from ambient noise records using seismic interferometry techniques has been widely used for multiscale shear wave velocity (Vs) imaging. One key step during Vs imaging is the generation of dispersion spectra and the extraction of a reliable dispersion curve from the retrieved surface waves. However, the sparse array geometry usually affects the ability for high-frequency (>1 Hz) seismic signals’ acquisition. Dispersion measurements are degraded by array response due to sparse sampling and often present smeared dispersion spectra with sidelobe artefacts. Previous studies usually focus on interferograms’ domain (e.g. cross-correlation function) and attempt to enhance coherent signals before dispersion measurement. We propose an alternative technique to explicitly deblur dispersion spectra through use of a phase-weighted slant-stacking algorithm. Numerical examples demonstrate the strength of the proposed technique to attenuate array responses as well as incoherent noise. Three different field examples prove the flexibility and superiority of the proposed technique: the first data set consists of ambient noise records acquired using a nodal seismometer array; the second data set utilizes distributed acoustic sensing (DAS) and a marine fibre-optic cable to acquire a similar ambient noise data set; the last data set is a vibrator-based active-source surface wave data. The enhanced dispersion measurements provide cleaner and higher-resolution spectra without distortions which will assist both human interpreters as well as ML algorithms in efficiently picking curves for subsequent Vs inversion.
Linear Periods of Automorphic Sheaves for GL2n
Authors: Lysenko S
Published: March 2021

We calculate, in the framework of the geometric Langlands program, the periods of cuspidal automorphic sheaves for $\operatorname{GL}_{2n}$ along the Levi subgroup $\operatorname{GL}_n\times \operatorname{GL}_n$. We also solve the corresponding local problem.
Borel and Volume Classes for Dense Representations of Discrete Groups
Authors: Farre James
Published: March 2021

We show that the bounded Borel class of any dense representation $\rho : G\to{\operatorname{PSL}}_n{\mathbb{C}}$ is non-zero in degree three bounded cohomology and has maximal semi-norm, for any discrete group $G$. When $n=2$, the Borel class is equal to the three-dimensional hyperbolic volume class. Using tools from the theory of Kleinian groups, we show that the volume class of a dense representation $\rho : G\to{\operatorname{PSL}}_2{\mathbb{C}}$ is uniformly separated in semi-norm from any other representation $\rho ^{\prime}: G\to{\operatorname{PSL}}_2 {\mathbb{C}}$ for which there is a subgroup $H\le G$ on which $\rho $ is still dense but $\rho ^{\prime}$ is discrete or indiscrete but stabilizes a point, line, or plane in ${\mathbb{H}}^3\cup \partial{\mathbb{H}}^3$. We exhibit a family of dense representations of a non-abelian free group on two letters and a family of discontinuous dense representations of ${\operatorname{PSL}}_2{\mathbb{R}}$, whose volume classes are linearly independent and satisfy some additional properties; the cardinality of these families is that of the continuum. We explain how the strategy employed may be used to produce non-trivial volume classes in higher dimensions, contingent on the existence of a family of hyperbolic manifolds with certain topological and geometric properties.