bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of gas permeability of abrasive tools on their structural and mechanical parameters
Authors: Bagaiskov Yu
Published: December 2021

Quality assurance and processing capacity are essential performance parameters of abrasive tools. It is of prime importance for grinding wheels operating at a speed of 35–60 m/s. In this case, the opportunities to increase the high-rate grinding efficiency without burns are associated with using high-porosity and low-hardness wheels. Artificial pore-forming agents are used to manufacture tools. Introduction of pore-forming agents decreases grinding forces and increases the maximum grinding depth without burns. The porosity of filled compound materials can be attributed to the conception of gas permeability. The gas permeability parameter describes the openness degree of such structures and the velocity of the air volumes passing through porous materials. The porosity and gas-permeability degrees of the material of high-porous ceramic-bond abrasive tools with various parameters, depending on the abrasive material type, porogen grain size and content, and the composite structure number have been studied. It appeared that the porosity degree of high-porous abrasive tools, made both of fused alumina and silicon carbide increases as the structure number, grain size, and content of burning porogens increases. Besides, the increase degree of fused alumina is a little higher than that of silicon carbide. The gas permeability degree depends on the factors mentioned above in nearly the same way. Compared to porosity, the effect of gas permeability increases due to an altered structure, grain size, and content of porogens is much higher, up to 6 times. In this case, the gas permeability value is primarily characteristic of the pore size; in other words, the speed and volume of the air or lubrication and cooling fluid penetrating the material structure increase correspondingly at nearly the same increase of the pore size by several times and at the same volume porosity degree. The gas permeability degree can be used for quantitative and qualitative description of the material structure of high-porous abrasive tools, as well as their structural and mechanical parameters. The operating parameters of tools can depend on the gas permeability level of their materials. Thus, the results of abrasive processing can be foreseen.
Assessment of the current technical condition of electrical equipment based on an artificial neural network
Authors: Manusov V Z , Otuzbaev M R , Scherbinina M A , Ivanov G V
Published: December 2021

Assessment of the current technical condition is an important task, so the state of electrical equipment depends on its further operability. Thanks to modern computing devices, it is possible to implement actively artificial intelligence and computer-assisted learning methods that allow achieving high efficiency in data processing. A study was conducted and an algorithm for diagnosing the technical condition based on an artificial neural network was developed. A model based on a multilayer perceptron is proposed, which allows evaluating the technical condition of a high-voltage power transformer. The result of the technical diagnostics of the model is the assignment of the condition to one of the five classes, proposed by the guidelines presented by the International Council on Large Electrical Systems. The methodology is presented on the example of a 250 MVA transformer with a certain defect history, which allowed us to show the reliability and validity of the obtained results. It is shown that the use of the proposed model makes it possible to achieve accuracy in determining the technical condition of 0.95. The introduction of this model into an automated monitoring and diagnostics system will allow assessing the technical condition of electrical equipment in real time with sufficient accuracy.
Short-term forecasting of wind and solar power generation
Authors: Manusov V Z , Khaldarov S K , Palagushkin B V
Published: December 2021

It is important to note that the generated power of renewable sources depends on the natural conditions at a particular geographic point, the level of wind flow speeds and solar radiation. The patterns characterizing these parameters depend on the time of year, locality and are purely probabilistic in nature. Taking into account the above-mentioned conditions for the effective implementation of “green” objects in the power supply system, the purpose of this work is to build forecasting models that are more likely to be able to determine what part of the load can be covered by the power supply system based on wind power and solar installations. This purpose was achieved by constructing and training artificial neural networks with data on the speed of wind flow and solar radiation obtained from real renewable energy facilities. The most significant result is the identification of the necessary forecasting horizon, taking into account the preservation of a relatively good quality of metrics, as well as understanding what additional data is required to improve this quality. The significance of the results obtained lies in the fact that they make it possible to determine what reserve capacity is required to be included in the project.
The comparison of a discrete-continuous approach and a method of finite differences in solving the problem of unsteady-state heat and moisture transfer in the building envelope
Authors: Zhou Z , Zubarev K P
Published: December 2021

This article is devoted to the development of methods for calculating heat and humidity regime in the building envelope. The equation of steady-state thermal conductivity with boundary conditions of the third kind and the formula for calculating heat losses of a building based on the heat transfer equation have been considered. The equation of unsteady-state thermal conductivity as well as its solution using the discrete-continual approach has also been studied. The solution of the unsteady-state heat conductivity problem with invariable over time boundary conditions using the discrete-continuous approach was proposed by A.B. Zolotov and P.A. Akimov. The subsequent modernization of the solution was conducted by V.N. Sidorov and S.M. Matskevich. The unsteady-state equation of moisture transfer based on Fick’s second law using the theory of moisture potential is derived. The solution of the unsteady-state moisture transfer equation using the finite difference method according to an explicit difference scheme as well as the solution of the unsteady-state moisture transfer equation using the discrete-continuous approach is demonstrated. To prove the effectiveness of using the discrete-continuous approach in the area of the unsteady-state humidity conditions we compared the calculation results of the distribution of moisture in a single-layer enclosing structure made of aerated concrete using two methods of moisture potential theory. It was found that the difference in the results of calculation by the discrete-continual formula and by the method of finite differences does not exceed 3.2%.
Temperature regime of painted parts in awning-type drying chambers at low ambient temperatures
Authors: Yakovlev P , Prosvirina I
Published: December 2021

The paper considers the problem of colouring large-sized objects, such as modules of sea and river vessels at low ambient temperatures. The temperature distribution depends on the thermal resistance of the walls of the drying chamber, the main characteristics of the heater fan, the dimensions of the chamber and the painted module, the gaps between the walls. The calculation should take into account the aerodynamic resistance of the drying chamber with the part placed in it, the influence of free convection, heat loss and the peculiarities of air distribution inside the shelter. The paper presents the results of a study of the influence of the size of the drying chamber, the size of the painted module, ambient temperatures and air coming from the heater, fan parameters, methods of placing the fan and exhaust ventilation on the range of air temperature changes in the tent. The methods of numerical modelling and experimental studies were used in the study. Based on the results obtained, a calculation method is proposed that allows determining the decrease in temperature inside the chamber relative to the temperature of the air coming from the heater. To automate the calculations, a program has been developed to determine the parameters of the air after heating with a fan heater.
Heat capacity of dispersed rocks
Authors: Galkin A F , Yu Pankov V
Published: December 2021

Protection of automobile roads from negative cryogenic processes is a current issue to which significant attention is devoted in both scientific and engineering communities. In many cases important for practice, the the thermal factor determines the reliability and security of the use of the road in the cryolithic zone. The heat capacity of dispersed rocks is among the most important indicators of the physical properties determining the intensity of thermal processes in the road surfaces and road foundations. The precision of determination of the total heat capacity of the rocks in thawed and frozen state largely determines the precision of the forecast of the thermal regime of roads in the cryolithic zone. A complex assessment of the impact of ice content of the dispersed rocks on the value of total heat capacity was done. 2D and 3D charts which allow to assess the possible range of change in the heat capacity of the dispersed rocks in thawed and frozen state, in both a wide range and in the typical range of values, were produced. Among the main criteria determining the extent of the seasonal freezing and thawing of the soils of the active layer is the Stefan number, a dimensionless criterion. An overall assessment of the impact of ice content on the ground (rock) foundations of the roads and of the air temperature in the warm period of the year on the quantitative values of the Stefan number was done. Charts allowing to determine in both a wide and typical range the changes of values of the Stefan numbers, permitting to assess the possible range of changes of the Stefan number, were made. It was determined, in particular, that for the typical dispersed rocks of the road foundations in the cryolithic zone the range of change in the Stefan numbers is 2.1-6.5.
Determination of melt composition in an open-arc ore-thermal furnace
Authors: Vasilev V V
Published: December 2021

The aim of the study is to improve the technical and economic performance of the normal electrocorundum production process in an ore-thermal furnace by automated control of the melt composition at the final stage. The essence of the research is to exploit the valve effect of an AC arc. The expression for the Al2O3 content in the melt was obtained from the electrical characteristics of the melt. Studies have shown a fairly high degree of accuracy in the convergence of the results of the proposed method with laboratory data.
Investigation of the effect of laser surface modification on the hardness and wear resistance of a titanium alloy
Authors: Belyaev L V , Zhdanov A V
Published: December 2021

The effect of laser modification of the surface on the value of the coefficient of elasticity, hardness, coefficient of friction and the amount of wear of the counter body when testing products made of a deformable titanium alloy was investigated. It was found that the indicators of hardness and wear resistance of a titanium alloy depend on the modes of laser modification. These dependencies are extreme in nature, they have maxima and minima. The quantitative values of hardness and wear resistance indicators for the specified material before and after laser treatment of its surface in various modes are given.
Local thermodynamic equilibrium in a laser-induced plasma channel formed by interaction of femtosecond laser radiation with argon
Authors: Kochuev D A , Galkin A F , Chernikov A S , Chkalov R V , Voznesenskaya A A , Khorkov K S , Egorova A V
Published: December 2021

In this paper, we estimate the possibility of applying local thermodynamic equilibrium conditions for a laser-induced plasma channel formed by femtosecond laser radiation in an argon medium at different pressures. The presence of a local thermodynamic equilibrium was determined on the basis of the time of heat exchange of electrons with argon atoms. The Saha equation is used to estimate the concentration of free electrons, the temperature of the laser-induced plasma channel, and its conductivity. A necessary condition for using this ratio was the presence of a state of local thermodynamic equilibrium in the plasma under study.
Modeling of led luminaires with optimal temperature operation of leds
Authors: Shirobokova T A , Surinsky D O , Egorov S V
Published: December 2021

In this article the design of light-emitting diode lamps with optimum thermal operating mode of the LEDs used are considered. Thermal analysis of the model is performed using SolidWorks Simulation software.
Surface acoustic wave temperature properties in alpha-GeO2 crystal
Authors: Taziev R M
Published: December 2021

In this study, the surface acoustic wave (SAW) temperature properties in flux-grown α-GeO2 crystal are numerically investigated. It is shown that the SAW velocity temperature change substantially depends only on the temperature coefficient of three elastic constants: C66, C44 and C14 for crystal cuts and wave propagation directions, where SAW has high electromechanical coupling coefficient. The SAW temperature coefficient of delay (TCD) for these crystal cuts are in the range from -40 ppm /°C to -70 ppm /°C. In contrast to alpha-quartz, the surface wave TCD values are not equal to zero in Z-, Y- , and Z- rotated cuts of α-GeO2 single crystal. Its values are comparable in the magnitude with the surface wave TCD values in lithium tantalate. In the crystal grown from the melt, the interdigital transducer (IDT) conductance has two times larger amplitude than that in hydrothermally grown a-GeO2. The leaky acoustic wave excited by IDT on Z+120°-cut and wave propagation direction along the X-axis, has an electromechanical coupling coefficient 5 times less than that for surface wave.
A phenomenological theory-based viscosity model for shear thickening fluids
Authors: Lin Kun , Qi Jiapeng , Liu Hongjun , Wei Minghai , Peng Hua Yi
Published: December 2021

A viscosity model for shear thickening fluids (STFs) based on phenomenological theory is proposed. The model considers three characteristic regions of the typical material properties of STFs: a shear thinning region at low shear rates, followed by a sharp increase in viscosity above the critical shear rate, and subsequently a significant failure region at high shear rates. The typical S-shaped characteristic of the STF viscosity curve is represented using the logistic function, and suitable constraints are applied to satisfy the continuity of the viscosity model. Then, the Levenberg–Marquardt algorithm is introduced to fit the constitutive model parameters based on experimental data. Verification against experimental data shows that the model can predict the viscosity behavior of STF systems composed of different materials with different mass concentrations and temperatures. The proposed viscosity model provides a calculation basis for the engineering applications of STFs (e.g., in increasing impact resistance and reducing vibration).
Substrate specificity of glycoside hydrolase family 1 β-glucosidase AtBGlu42 fromArabidopsis thalianaand its molecular mechanism
Authors: Horikoshi Shu , Saburi Wataru , Yu Jian , Matsuura Hideyuki , Cairns James R Ketudat , Yao Min , Mori Haruhide
Published: December 2021

Plants possess many glycoside hydrolase family 1 (GH1) β-glucosidases, which physiologically function in cell wall metabolism and activation of bioactive substances, but most remain uncharacterized. One GH1 isoenzyme AtBGlu42 in Arabidopsis thaliana has been identified to hydrolyze scopolin using the gene deficient plants, but no enzymatic properties were obtained. Its sequence similarity to another functionally characterized enzyme Os1BGlu4 in rice suggests that AtBGlu42 also acts on oligosaccharides. Here, we show that the recombinant AtBGlu42 possesses high kcat/Km not only on scopolin, but also on various β-glucosides, cellooligosaccharides, and laminarioligosaccharides. Of the cellooligosaccharides, cellotriose was the most preferred. The crystal structure, determined at 1.7 Å resolution, suggests that Arg342 gives unfavorable binding to cellooligosaccharides at subsite +3. The mutants R342Y and R342A showed the highest preference on cellotetraose or cellopentaose with increased affinities at subsite +3, indicating that the residues at this position have an important role for chain length specificity.
GC Determination of Fluorouracil in Serum by Using Hexafluroroacetylacetone as Derivatizing Reagent
Authors: Zounr Rizwan Ali , Khuhawar Muhammad Yar , Khuhawar Taj Muhammad Jahangir , Lanjwani Muhammad Farooque , Khuhawar Muzamil Yar
Published: December 2021

A gas chromatographic (GC) procedure has been developed for the determination of fluorouracil (5-FU) after pre-column derivatization with hexafluoroacetylacetone. GC separation was from column DB-1 (30 m × 0.32 mm id) and the determination was by flame-ionization detection. The derivatization conditions were optimized at pH 4, heating at 90°C for 40 min and extraction of the derivative was in chloroform. Using the conditions nucleobases cytosine, uracil, thymine, adenine and guanine separated completely from fluorouracil. The linear calibration range and LOD for 5-fluorouracil were 0.5–40.0 and 0.2 μg/mL, respectively. The derivatization, elution and separation were repeatable in terms of retention time and peak height/peak area (n = 5) and relative standard deviations (RSD) were within 3.5%. The method was applied for the analysis of serum spiked with 5-FU with recovery of 95.5–97.5% with RSD 1.5–3.1%.
Effectiveness of 13-Valent Pneumococcal Conjugate Vaccine Against Medically Attended Lower Respiratory Tract Infection and Pneumonia Among Older Adults
Authors: Lewnard Joseph A , Bruxvoort Katia J , Fischer Heidi , Hong Vennis X , Grant Lindsay R , Jódar Luis , Cané Alejandro , Gessner Bradford D , Tartof Sara Y
Published: December 2021

Background

Among older adults, 13-valent pneumococcal conjugate vaccine (PCV13) has been found efficacious against nonbacteremic pneumonia associated with vaccine-serotype pneumococci. However, the burden of lower respiratory tract infection (LRTI) and pneumonia preventable by direct immunization of older adults continues to be debated.

Methods

We analyzed data from an open cohort of adults aged ≥65 years enrolled in Kaiser Permanente Southern California health plans from 2016 to 2019 who received PCV13 concordant with US Advisory Committee on Immunization Practices guidelines. We estimated PCV13 vaccine effectiveness (VE) via the adjusted hazard ratio for first LRTI and pneumonia episodes during each respiratory season, comparing PCV13-exposed and PCV13-unexposed time at risk for each participant using a self-matched inference framework. Analyses used Cox proportional hazards models, stratified by individual.

Results

Among 42 700 adults who met inclusion criteria, VE was 9.5% (95% confidence interval [CI], 2.2% to 16.3%) against all-cause medically attended LRTI and 8.8% (95% CI, –.2% to 17.0%) against all-cause medically attended pneumonia. In contrast, we did not identify evidence of protection against LRTI and pneumonia following receipt of the 23-valent pneumococcal polysaccharide vaccine. PCV13 prevented 0.7 (95% CI, .2 to 1.4) and 0.5 (95% CI, .0 to 1.0) cases of LRTI and pneumonia, respectively, per 100 vaccinated persons annually; over 5 years, 1 case of LRTI and 1 case of pneumonia were prevented for every 27 and 42 individuals vaccinated, respectively.

Conclusions

PCV13 vaccination among older adults substantially reduced incidence of medically attended respiratory illness. Direct immunization of older adults is an effective strategy to combat residual disease burden associated with PCV13-type pneumococci.
Detecting cardiomyopathies in pregnancy and the postpartum period using ECG
Authors: Adedinsewo D , Johnson P W , Douglass E J , Attia Z I , Phillips S D , Goswami R M , Yamani M H , Connolly H M , Rose C H , Sharpe E E , Lopez-Jimenez F , Friedman P A , Carter R E , Noseworthy P A
Published: December 2021

Background

Cardiovascular disease (CVD) has been identified as a major threat to maternal health in the US and UK with cardiomyopathy being one of the most common acquired CVD in the pregnant and postpartum period. Diagnosing cardiomyopathy in pregnancy is challenging due to an overlap of cardiovascular symptoms with normal pregnancy symptoms.

Purpose

The purpose of this study was to evaluate the effectiveness of an ECG based deep learning model in identifying cardiomyopathy among pregnant and postpartum women.

Methods

We utilized an ECG based deep learning model to detect cardiomyopathy in a cohort of pregnant or postpartum women seen at multiple hospital sites. Model performance was evaluated using area under the curve (AUC), accuracy, sensitivity, and specificity. We compared the diagnostic probabilities of the deep learning model with natriuretic peptides and a multivariable model consisting of demographic and clinical parameters.

Results

1,807 women were included. 7%, 10% and 13% had LVEF ≤35%, <45% and <50% respectively. The ECG based deep learning model identified cardiomyopathy with an AUC of 0.92 for left ventricular ejection fraction (LVEF) ≤35%, 0.89 for LVEF <45% and 0.87 for LVEF <50%. For LVEF ≤35%, AUC was higher in Black (0.95) and Hispanic (0.98) women compared to white (0.91). Natriuretic peptides and the multivariable model had AUCs of 0.85 and 0.72 respectively.

Conclusions

A deep learning model effectively identifies cardiomyopathy in pregnant or postpartum women, outperforms natriuretic peptides and traditional clinical parameters with the potential to become a powerful initial screening tool for cardiomyopathy in the obstetric care setting.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This study was made possible using resources supported by the Mayo Clinic Women's Health Research Center and the Mayo Clinic Building Interdisciplinary Research Careers in Women's Health (BIRCWH) Program funded by the National Institutes of Health (NIH), grant number K12 HD065987. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Improving adherence to cholesterol lowering guidelines through an interactive digital tool
Authors: Rashid S , Suero-Abreu G A , Tysarowki M , Um H , Zhang Y , Shah K , Douglas A , Matassa D
Published: December 2021

Background

Statins are the cornerstone of primary and secondary prevention of atheroscleoric cardiovascular disease (ASCVD). Our previous retrospective analysis of 1042 consecutive patient encounters at a large urban academic institution found that one in five patients were not prescribed an appropriate statin therapy. These patients tended to be younger, of Black race, and met statin-eligibility solely via a 10-year ASCVD risk score ≥7.5%. Only one-third of patients had follow-up cholesterol levels ordered to monitor treatment efficacy.

Purpose

To improve adherence to cholesterol guidelines at our academic institution.

Methods

We implemented multiple interventions over a four-month period to support clinical decision making of guideline directed statin therapy: a) development of an online interactive tool, b) physician education on updated cholesterol guidelines and utilization of the tool, c) display of guideline summary in the workspace, and d) a documentation reminder in the electronic health record. We randomly selected encounter dates, from which 622 consecutive patient visits were analyzed. The primary outcome measures were: prescription rates of statins, documentation of a 10-year ASCVD risk score, and follow-up cholesterol levels ordered to monitor treatment efficacy.

Results

Out of the 622 patients, 232 met statin indication. In this post-intervention group, statin prescriptions rates improved when compared to the pre-intervention group (90.5% vs 82.3%, p=0.006). Among the patients who met statin indication solely via a 10-year ASCVD risk score ≥7.5%, there was an increase in documentation of the calculated 10-year ASCVD risk score (72.3% vs 57.8%; p=0.039) and in statin prescription rate (90.8% vs 67.6%; p<0.001). In addition, there was an increase in follow-up cholesterol levels ordered in all patients included in our study who met statin indication (64.1% vs 33.3%; p<0.001).

Conclusion

Our study showed higher rates of statin prescription, 10-year ASCVD risk score documentation, and treatment monitoring after multiple interventions, including an easily accessible online interactive tool, at a large urban academic institution.

Funding Acknowledgement

Type of funding sources: None. Statin Prescription Rates
The feasibility of algorithm-based ECG interpretation in remote monitoring – 53,748 recordings from the Dutch HartWacht program
Authors: Blok S , Slaats B M I , Somsen G A , Tulevski I I , Hofstra L , Winter M M
Published: December 2021

Background

Symptom driven remote monitoring programs for cardiac arrhythmias hold great promise, but scalability is limited due to high additional workload for healthcare providers. The Dutch HartWacht arrhythmia program consists of a connected single lead ECG device operated remotely by the patient, an algorithm for classification and a dedicated team of specialized nurses and cardiologists for additional remote interpretation. Correct classification as sinus rhythm (SR) by the algorithm would reduce workload of the HartWacht team, as it makes double-checking redundant.

Purpose

We investigated agreement of the ECG-classification between the algorithm and the HartWacht team and determined feasibility of the algorithm to classify sinus rhythm (SR).

Methods

We investigated the algorithm accompanying a single lead, handheld ECG-device that is integrated in the Dutch HartWacht program. We retrospectively studied the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the algorithm for classifying SR on home measured 30-second single lead ECGs. We included all recordings that were classified as SR by the algorithm. We used the classification of the HartWacht team as a reference standard.

Results

Between April 2020 and January 2021, 1,671 patients with (suspected) arrhythmias (female = 982 (59%), mean age = 58 (±15) years, participating in the HartWacht program, recorded 53,748 ECGs, of which the algorithm interpreted 35,388 (66%) as SR, 10,899 (20%) as possible AF and 7,461 (14%) as other. All recordings were also interpreted by the HartWacht team. Compared to the classification by the team, the algorithm showed a sensitivity for SR of 0.953, specificity of 0.985, PPV of 0.996 and NPV of 0.841. A total of 137 (0,3%) ECGs from 50 (2,8%) patients showed false positive outcomes, classifying recordings as SR while the HartWacht team detected arrhythmias. In 42 of those patients, arrhythmias were detected by the algorithm in other recordings within the program. The remaining 8 (0,5%) patients made a total of 14 (<0,1%) recordings with false positive outcomes without having any other recordings with arrhythmias within the HartWacht program.

Conclusion

For classifying SR in home measured single lead ECGs, the algorithm and the HartWacht team showed a nearly perfect agreement. The recordings without agreement did not lead to relevant individual changes in diagnostic or therapeutic strategy for the patient. Therefore, the algorithm is feasible as standalone classification. With 66% of the recordings within the HartWacht program showing SR, a corresponding workload reduction can be achieved which importantly increases scalability and cost-effectiveness of remote monitoring of arrhythmia patients.

Funding Acknowledgement

Type of funding sources: None.
Cesarean section and breastfeeding outcomes in an Indigenous Qom community with high breastfeeding support
Authors: Martin Melanie , Keith Monica , Olmedo Sofía , Edwards Deja , Barrientes Alicia , Pan Anwesha , Valeggia Claudia
Published: December 2021

Background and objectives

Cesarean section may lead to suboptimal breastfeeding outcomes, though evidence has been mixed. Factors, such as premature birth, birth weight and maternal age may independently increase risk of cesarean and hinder breastfeeding initiation, while maternal preferences, support and sociostructural barriers may influence breastfeeding practices beyond the immediate postpartum period.

Methodology

We assessed impacts of cesarean section and gestational factors on breastfeeding duration among Indigenous Qom mothers in Argentina who have strong traditional breastfeeding support. We modeled transitions from exclusive breastfeeding to complementary feeding and from complementary feeding to full weaning in a Bayesian time-to-event framework with birth mode and gestational covariates (n = 89 infants).

Results

Estimated median time to full weaning was 30 months. Cesarean-delivered babies were weaned an average of 5 months later adjusting for gestational age, maternal parity and infant sex. No factors were associated with time-to-complementary feeding, and time-to-complementary feeding was not associated with time-to-full weaning.

Conclusions and implications

Among Indigenous Qom mothers in Argentina, cesarean section was not associated with suboptimal breastfeeding outcomes. Although some Qom mothers do experience early breastfeeding problems, particularly following first birth, problems are not more frequent following cesarean delivery. Traditional postpartum kin and community support during prolonged postpartum periods may be instrumental in helping mothers to overcome early breastfeeding problems due to cesarean or other risk factors.
Early Exposure to County Income Mobility and Adult Individual Health in the United States
Authors: Daza Sebastian , Palloni Alberto
Published: December 2021

Objectives

Previous research in the United States suggests contextual income mobility may play a role in explaining the disparities between life expectancy in the United States and peer countries. This article aims to extend previous research by estimating the consequences of average individual exposure to mobility regimes during childhood and adolescence on adult health.

Methods

This study draws its data from two longitudinal datasets that track the county of residence of respondents during childhood and adolescence, the Panel Study of Income Dynamics and the National Longitudinal Survey of Youth 1997. We implement marginal structural models to assess the association of the average exposure to county income mobility on five health outcomes and behaviors.

Results

The results are only partially consistent with a systematic association between exposure to income mobility and health outcomes. Evidence obtained from the National Longitudinal Survey of Youth suggests less income mobility might increase the probability of smoking by age 30.

Discussion

The paper provides a precise assessment of the hypothesis that childhood exposure to income mobility regimes may influence health status through behavior later in life and contribute to longevity gaps. Only partial evidence on smoking suggests an association between income mobility and health, so we discuss potential reasons for the disparities in results with previous research.
Intersectoral collaboration in a Dutch community health promotion programme: building a coalition and networks
Authors: de Jong Marja , Tijhuis Yvon , Koelen Maria , Wagemakers Annemarie
Published: December 2021

In health promotion programmes (HPP), it is crucial to have intersectoral collaboration within coalitions and to build networks between health and other societal sectors. A health broker role is recognized as being helpful in connecting the coalition with the broader network, and participatory action research (PAR) is deemed supportive because it facilitates evaluation, reflection, learning and action. However, there is a lack of insight into how processes that affect collaboration develop over time. Therefore, this study aimed to provide insights into the coalition’s processes that facilitate building and maintaining intersectoral collaboration within a HPP coalition and network and how these processes contribute to the coalition’s ambitions. As part of PAR, the coalition members used the coordinated action checklist (CAC) and composed network analysis (CNA) in 2018 and 2019. The CAC and CNA results were linked back into the coalition in five group sessions and used for reflection on pro-gress and future planning. Coalition governance, interaction with the context, network building and brokerage, and generating visibility emerged as the most prominent processes. Important insights concerned the health broker’s role and positioning, the programme coordinator’s leadership and the importance of visibility and trust leading to investment in continuation. The combined research instruments and group sessions supported discussion and reflection, sharing visions and adjusting working strategies, thereby strengthening the coalition’s capacity. Thus, PAR was useful for evaluating and simultaneously facilitating the processes that affect collaboration.
Systematic identification of genomic elements that regulateFCGR2Aexpression and harbor variants linked with autoimmune disease
Authors: Dahlqvist Johanna , Fulco Charles P , Ray John P , Liechti Thomas , de Boer Carl G , Lieb David J , Eisenhaure Thomas M , Engreitz Jesse M , Roederer Mario , Hacohen Nir
Published: December 2021

Background: FCGR2A binds antibody–antigen complexes to regulate the abundance of circulating and deposited complexes along with downstream immune and autoimmune responses. Although the abundance of FCRG2A may be critical in immune-mediated diseases, little is known about whether its surface expression is regulated through cis genomic elements and non-coding variants. In the current study, we aimed to characterize the regulation of FCGR2A expression, the impact of genetic variation and its association with autoimmune disease. Methods: We applied CRISPR-based interference and editing to scrutinize 1.7 Mb of open chromatin surrounding the FCGR2A gene to identify regulatory elements. Relevant transcription factors (TFs) binding to these regions were defined through public databases. Genetic variants affecting regulation were identified using luciferase reporter assays and were verified in a cohort of 1996 genotyped healthy individuals using flow cytometry. Results: We identified a complex proximal region and five distal enhancers regulating FCGR2A. The proximal region split into subregions upstream and downstream of the transcription start site, was enriched in binding of inflammation-regulated TFs, and harbored a variant associated with FCGR2A expression in primary myeloid cells. One distal enhancer region was occupied by CCCTC-binding factor (CTCF) whose binding site was disrupted by a rare genetic variant, altering gene expression. Conclusions: The FCGR2A gene is regulated by multiple proximal and distal genomic regions, with links to autoimmune disease. These findings may open up novel therapeutic avenues where fine-tuning of FCGR2A levels may constitute a part of treatment strategies for immune-mediated diseases.
Convergence of Lagrange finite elements for the Maxwell eigenvalue problem in two dimensions
Authors: Boffi Daniele , Guzmán Johnny , Neilan Michael
Published: December 2021

We consider finite element approximations of the Maxwell eigenvalue problem in two dimensions. We prove, in certain settings, convergence of the discrete eigenvalues using Lagrange finite elements. In particular, we prove convergence in three scenarios: piecewise linear elements on Powell–Sabin triangulations, piecewise quadratic elements on Clough–Tocher triangulations and piecewise quartics (and higher) elements on general shape-regular triangulations. We provide numerical experiments that support the theoretical results. The computations also show that, on general triangulations, the eigenvalue approximations are very sensitive to nearly singular vertices, i.e., vertices that fall on exactly two ‘almost’ straight lines.
Balanced Curves and Minimal Rational Connectedness on Fano Hypersurfaces
Authors: Ran Ziv
Published: December 2021

On a general hypersurface $X$ of degree $n$ (resp. $<n$) in ${\mathbb {P}}^n$ and any $e\geq n-1$ (resp. arbitrarily large $e$), we construct families of rational curves of degree $e$ going through the maximal number of general points. This solves in many cases the problem of rational curve interpolation on $X$.
Structural and biochemical elements of efficiently degradable proteasome substrates
Authors: Tomita Takuya
Published: December 2021

Most regulated proteolysis in cells is conducted by the ubiquitin-proteasome system (UPS), in which proteins to be eliminated are selected through multiple steps to achieve high specificity. The large protease complex proteasome binds to ubiquitin molecules that are attached to the substrate and further interacts with a disordered region in the target to initiate unfolding for degradation. Recent studies have expanded our view of the complexity of ubiquitination as well as the details of substrate engagement by the proteasome and at the same time have suggested the characteristics of substrates that are susceptible to proteasomal degradation. Here, I review some destabilizing elements of proteasome substrates with particular attention to ubiquitination, initiation region and stability against unfolding and discuss their interplay to determine the substrate stability. A spatial perspective is important to understand the mechanism of action of proteasomal degradation, which may be critical for drug development targeting the UPS including targeted protein degradation.
Pontonia margaritaVerrill, 1869 (Decapoda: Caridea: Palaemonidae) as a symbiont ofPinna rugosaSowerby, 1835 (Mollusca: Bivalvia) on both coasts of the Baja California Peninsula, Mexico
Authors: Vélez-Arellano Nurenskaya , Medina-Gómez Sandra P , Magaña Joaquín D , Camacho-Mondragón Marian A , Rábago-Quiroz Carlos H
Published: December 2021

Many caridean shrimps live in symbiosis with bivalves, the shrimps finding refuge and food in the mucus in their host’s mantle cavity. We report for the first time the presence of Pontonia margarita Verrill, 1869 on both coasts of Baja California Peninsula, Mexico, as a symbiont of the pen shell Pinna rugosa Sowerby, 1835. The symbiont was found in Laguna Ojo de Liebre (LOL), which faces the Pacific Ocean, and in Bahía Concepción (BC), on the eastern coast facing the Gulf of California. A total of 569 specimens of Pinna rugosa were studied, 472 from LOL (104–277 mm shell length (SL)) and 97 from BC (130–234 mm SL). A total of 376 Pontonia margarita individuals were extracted in LOL (19–41 mm total length (TL)) and 41 in BC (20–48 mm TL). The prevalence of Pontonia margarita was 46% in LOL and 28% in BC. The regression analyses for both sexes of Pontonia margarita showed a high correlation between TL and total weight and abdominal length and TL. The data showed a moderate correlation between TL and the length of the major and minor chelae, and TL and length of the minor chela. There was no significant relationship between biometric parameters of the host and the symbiont. The presence of gravid females of Pontonia margarita (52% in LOL and 39% in BC) in shells suggests reproduction during autumn.
Too Vulnerable to Participate? A Systematic Literature Review of the Gap between a Right to Participate and Participation, in Welfare Services
Authors: Strømland Monica , Bahus Marianne K , Andersen Anders J W
Published: December 2021

There is a need to reconceptualize children as competent and reflective actors in their own lives, acknowledging their right to be heard and to participate in meaningful ways. This article explores and suggests the means to overcome the gap between the formal right to participate and meaningful participation in welfare services that involve evaluating a child’s family environment. For this purpose, we conducted a systematic literature review to synthesize the qualitative literature on how children and young people who have been in contact with child welfare services experience participation in the making of decisions that affect their well-being. The articles collected from eight scientific databases indicate that despite a growing general emphasis on the importance of child participation over the past 25 years, the operationalization of children’s right to be heard is challenging in child welfare services. There are challenges at both the organizational level, with the failure to fully acknowledge and operationalize children’s right to be heard in a sufficient manner, and at the individual level, with a need to improve opportunities for communication that facilitate trustful relationships between child welfare social workers and children in need. Based on previous studies of participation in a child welfare context at different levels, we conclude that a legally clear framework in combination with the realization of Skivenes and Strandbu’s definition of participation would increase the chances that children’s interests and right to be heard are respected, protected, and implemented.
The kinematic properties of Milky Way stellar halo populations
Authors: Lane James M M , Bovy Jo , Mackereth J Ted
Published: December 2021

In the Gaia era, stellar kinematics are extensively used to study Galactic halo stellar populations, to search for halo structures, and to characterize the interface between the halo and hot disc populations. We use distribution function-based models of modern data sets with 6D phase space data to qualitatively describe a variety of kinematic spaces commonly used in the study of the Galactic halo. Furthermore, we quantitatively assess how well each kinematic space can separate radially anisotropic from isotropic halo populations. We find that scaled action space (the ‘action diamond’) is superior to other commonly used kinematic spaces at this task. We present a new, easy to implement selection criterion for members of the radially anisotropic Gaia–Enceladus merger remnant. Assuming a 1:1 ratio of Gaia–Enceladus stars to more isotropic halo, we find our selection achieves a sample purity of 86 per cent in our models with respect to contamination from the more isotropic halo. We compare this criterion to literature criteria, finding that it produces the highest purity in the resulting samples, at the expense of a modest reduction in completeness. We also show that selection biases that underlie nearly all contemporary spectroscopic data sets can noticeably impact the E−Lz distribution of samples in a manner that may be confused for real substructure. We conclude by providing recommendations for how authors should use stellar kinematics in the future to study the Galactic stellar halo.
Adolescents on the Autism Spectrum: Music Therapists’ Work with Speech-Language Pathologists
Authors: Guerriero Angela , Culp Mara E , Pierce-Goldstein Lisa
Published: December 2021

Adolescents on the autism spectrum may experience challenges with multiple domains of communication that impact their quality of life. Both music therapists and speech-language pathologists (SLPs) implement activities to address these challenges. Empirical evidence suggests that incorporating music into treatment can be an effective way to improve communication. The purpose of this article is to provide suggestions for music therapists assisting adolescents on the autism spectrum to improve their communication skills and ways to collaborate with SLPs in doing so. In this paper, we discuss interprofessional collaborative models (e.g., interdisciplinary, transdisciplinary) and competencies (e.g., coordination, adaptability), as well as music-based clinical experiences that appeal to adolescents, and target improvement of communication skills for learners with complex communication needs.
The nucleotide messenger (p)ppGpp is an anti-inducer of the purine synthesis transcription regulator PurR inBacillus
Authors: Anderson Brent W , Schumacher Maria A , Yang Jin , Turdiev Asan , Turdiev Husan , Schroeder Jeremy W , He Qixiang , Lee Vincent T , Brennan Richard G , Wang Jue D
Published: December 2021

The nucleotide messenger (p)ppGpp allows bacteria to adapt to fluctuating environments by reprogramming the transcriptome. Despite its well-recognized role in gene regulation, (p)ppGpp is only known to directly affect transcription in Proteobacteria by binding to the RNA polymerase. Here, we reveal a different mechanism of gene regulation by (p)ppGpp in Firmicutes: (p)ppGpp directly binds to the transcription factor PurR to downregulate purine biosynthesis gene expression upon amino acid starvation. We first identified PurR as a receptor of (p)ppGpp in Bacillus anthracis. A co-structure with Bacillus subtilis PurR reveals that (p)ppGpp binds to a PurR pocket reminiscent of the active site of phosphoribosyltransferase enzymes that has been repurposed to serve a purely regulatory role, where the effectors (p)ppGpp and PRPP compete to allosterically control transcription. PRPP inhibits PurR DNA binding to induce transcription of purine synthesis genes, whereas (p)ppGpp antagonizes PRPP to enhance PurR DNA binding and repress transcription. A (p)ppGpp-refractory purR mutant in B. subtilis fails to downregulate purine synthesis genes upon amino acid starvation. Our work establishes the precedent of (p)ppGpp as an effector of a classical transcription repressor and reveals the key function of (p)ppGpp in regulating nucleotide synthesis through gene regulation, from soil bacteria to pathogens.
Distinctive Features of Ertapenem-Mono-Resistant Carbapenem-Resistant Enterobacterales in the United States: A Cohort Study
Authors: Adelman Max W , Bower Chris W , Grass Julian E , Ansari Uzma A , Soda Elizabeth A , See Isaac , Lutgring Joseph D , Jacob Jesse T
Published: December 2021

Background

Carbapenem-resistant Enterobacterales (CRE) are highly antibiotic-resistant bacteria. Whether CRE resistant only to ertapenem among carbapenems (ertapenem “mono-resistant”) represent a unique CRE subset with regards to risk factors, carbapenemase genes, and outcomes is unknown.

Methods

We analyzed surveillance data from 9 CDC Emerging Infections Program (EIP) sites. A case was the first isolation of a carbapenem-resistant Enterobacter cloacae complex, Escherichia coli, Klebsiella aerogenes, K. oxytoca, K. pneumoniae, or K. variicola from a normally sterile site or urine in an EIP catchment area resident in 2016–2017. We compared risk factors, carbapenemase genes, antibiotic susceptibility, and mortality of ertapenem “mono-resistant” cases to “other” CRE cases (resistant to ≥1 carbapenem other than ertapenem) and analyzed risk factors for mortality.

Results

Of 2009 cases, 1249 (62.2%) were ertapenem-mono-resistant and 760 (37.8%) were other CRE. Ertapenem-mono-resistant CRE cases were more frequently ≥80 years old (29.1% vs 19.5%; P < .0001) and female (67.9% vs 59.0%; P < .0001). Ertapenem-mono-resistant isolates were more likely to be Enterobacter cloacae complex (48.4% vs 15.4%; P < .0001) but less likely to be isolated from a normally sterile site (7.1% vs 11.7%; P < .01) or to have a carbapenemase gene (2.4% vs 47.4%; P < .0001). Ertapenem-mono-resistance was not associated with 90-day mortality in logistic regression models. Carbapenemase-positive isolates were associated with mortality (odds ratio, 1.93; 95% CI, 1.30–2.86).

Conclusions

Ertapenem-mono-resistant CRE rarely have carbapenemase genes and have distinct clinical and microbiologic characteristics from other CRE. These findings may inform antibiotic choice and infection prevention practices, particularly when carbapenemase testing is not available.