bluuebunny/crossref_metadata_2025 huggingface dataset:
The association of photo‐induced collagen degeneration and the development of telangiectasias in rosacea
Authors: Thompson Katherine G. , Rainer Barbara M. , Leung Sherry , Qi Ji , Kang Sewon , Chien Anna L.
Published: January 2021

Rosacea is a chronic, often progressive disorder characterized by facial erythema, telangiectasias, papules, pustules, and/or rhinophyma. In this study, we investigated the tissue structure in rosacea compared to controls. We performed a case–control study between five patients with mild‐to‐moderate erythematotelangiectatic rosacea (ETR) and five matched controls. Facial biopsy samples from rosacea patients and controls were stained with picrosirius red for collagen and CD31 for microvessel identification. Mean collagen content was significantly greater in control samples (19.603% ±8.821%) compared to rosacea samples (16.812% ± 7.787%, p = 0.030). In contrast, mean microvessel density was significantly higher in rosacea patients (4.775 E‐5 ± 1.493 E‐5 µm−3) compared to controls (2.559 E‐5 ± 8.732 E‐6 µm−3, p = 0.004). Mean microvessel lumen area was also significantly higher in rosacea patients (491.710 ± 610.188 µm2) compared to controls (347.879 ± 539.624 µm2, p = 0.003). We identified a correlation between decreased collagen content and increased microvessel size and density in rosacea patients that was not observed in controls. These structural changes to the dermal matrix may contribute to the characteristic vessel growth and dilation in rosacea.
Analysis of the effectiveness of chemical peelings in the treatment of acne vulgaris assessed using high‐frequency ultrasound—A comparative study
Authors: Zdrada Julita , Odrzywołek Wiktoria , Deda Anna , Wilczyński Sławomir , Błońska‐Fajfrowska Barbara
Published: January 2021

Background

The use of high‐frequency ultrasound for noninvasive assessment of skin during chemical peeling therapies may be a useful tool.

Aims

To determine whether high‐frequency ultrasound is a useful tool to noninvasive assessment of skin and evaluation therapy progress.

Patients/Methods

The 14 women underwent four treatments with chemical peelings at 2‐week intervals. Before, after 4 weeks and after 9 weeks, photographic documentation and scans were recorded using a high‐resolution ultrasound system.

Results

As a result of applying pyruvic acid peeling, the thickness of the entrance echo on the forehead, cheek, and chin was reduced. After applying the peeling consisting of a mixture of glycolic and salicylic acids, the thickness of the entrance echo of the epidermis decreased on the forehead, cheek, and chin. As a result of applying a 50% pyruvic acid peeling, the density of dermis on the forehead, cheeks, and chin increased. A similar increase in the density of dermis was observed on the forehead, cheeks, and chin after applying a mixture of glycolic and salicylic acid.

Conclusion

High‐frequency ultrasound is a useful tool for monitoring the progress in the treatment of acne vulgaris using chemical peelings.
The Effectiveness of a Teen Outreach Pregnancy Prevention Program: Results From Youth After‐School Clubs
Authors: Sturgill Ronda , Martinasek Mary , Manke Laura
Published: January 2021

BACKGROUND

Teen pregnancy continues to burden families, communities, and society. Programs continue to educate and impower youth and young adults to make positive behavioral decisions.

METHODS

We evaluated a program aimed at high‐risk youth in after‐school programs. The goal of the program was to instill a sense of community and empathy, as well as sexual health decision‐making. The evaluation was a multiyear evaluation from external evaluators.

RESULTS

There were statistically significant changes in empathy toward others in the community and a feeling of safety at school. Other positive changes noted were that students felt empowered to use condoms, other barriers, or birth control in the future when having sexual relations. The program noted a positive direction in students feeling they develop plans or goals and stick to them.

CONCLUSIONS

These programs serve to instill a sense of empowerment, community, and responsibility in students. Evaluation data can serve as a metric of the merit of these programs and the impact on school health programs and communities.
Investigating paediatric hypoglycaemia: Dynamic studies at a tertiary paediatric hospital
Authors: Graves Lara E , Stewart Kelly , Ambler Geoffrey R , Bhattacharya Kaustuv , Srinivasan Shubha
Published: January 2021

Aim

Paediatric hypoglycaemia often requires specific investigations to determine aetiology. Samples from the time of hypoglycaemia may not be available and a diagnostic fasting test may be required. Additionally, fasting studies can determine safe fasting intervals and prolonged oral glucose challenges can assess hypoglycaemia due to abnormal post‐prandial glucose handling. This audit reviewed the current utility and yield of fasting studies, prolonged oral glucose challenges and starch loads.

Methods

Retrospective audit of clinical record to determine purpose and outcome of tests performed at a Tertiary Paediatric Endocrine/Metabolic Testing Unit in Sydney, Australia, from 2013 to 2018 inclusive.

Results

One hundred and thirty‐eight children (aged 3 weeks–17 years) underwent 170 tests: 122 fasting studies, 20 five‐hour OGTTs, 22 uncooked corn starch loads and six modified waxy maize starch (Glycosade) loads. The majority were for diagnostic purposes (n = 113, 66%), with 57 (34%) to guide management in patients with known diagnoses. Following diagnostic studies, 35 (31%) patients received a pathological diagnosis, the most common of which (n = 19, 17%) was accelerated starvation. Hypoglycaemia developed in n = 15/113 (13%) during the diagnostic studies. Management studies helped determine length of safe fast, adjustment of medication or diet and document resolution of pathology.

Conclusion

Fasting studies remain a safe and effective method to assist with diagnoses, confirm or exclude pathological causes of childhood hypoglycaemia and to guide management of known diagnoses in the paediatric population.
Influence of physical properties on the taste and flavor of strawberry jam
Authors: Kurotobi Tomoka , Hoshino Takayoshi , Kazami Yukari , Hayakawa Fumiyo , Hagura Yoshio
Published: January 2021

This study investigated the influence of the type and concentration of pectin on the sensory attributes and physical properties of a model strawberry jam. The methods used for the sensory evaluation and determination of physical characteristics that affect human taste and flavor perception are outlined. Increasing pectin concentration altered the solid (elastic) properties of the model strawberry jam. Each sensory attribute showed high correlation with various physical properties as determined by viscosity measurements. These results allowed us to predict the human oral cavity conditions during taste and flavor perception. From this study, it is clear that humans assess the physical properties of foods by the tongue movements and adjustments in the oral cavity conditions according to the taste and flavor characteristics.
Molecular pathophysiology of human MICU1 deficiency
Authors: Kohlschmidt Nicolai , Elbracht Miriam , Czech Artur , Häusler Martin , Phan Vietxuan , Töpf Ana , Huang Kai‐Ting , Bartok Adam , Eggermann Katja , Zippel Stephanie , Eggermann Thomas , Freier Erik , Groß Claudia , Lochmüller Hanns , Horvath Rita , Hajnóczky György , Weis Joachim , Roos Andreas
Published: January 2021

Aims

MICU1 encodes the gatekeeper of the mitochondrial Ca2+ uniporter, MICU1 and biallelic loss‐of‐function mutations cause a complex, neuromuscular disorder in children. Although the role of the protein is well understood, the precise molecular pathophysiology leading to this neuropaediatric phenotype has not been fully elucidated. Here we aimed to obtain novel insights into MICU1 pathophysiology.

Methods

Molecular genetic studies along with proteomic profiling, electron‐, light‐ and Coherent anti‐Stokes Raman scattering microscopy and immuno‐based studies of protein abundances and Ca2+ transport studies were employed to examine the pathophysiology of MICU1 deficiency in humans.

Results

We describe two patients carrying MICU1 mutations, two nonsense (c.52C>T; p.(Arg18*) and c.553C>T; p.(Arg185*)) and an intragenic exon 2‐deletion presenting with ataxia, developmental delay and early onset myopathy, clinodactyly, attention deficits, insomnia and impaired cognitive pain perception. Muscle biopsies revealed signs of dystrophy and neurogenic atrophy, severe mitochondrial perturbations, altered Golgi structure, vacuoles and altered lipid homeostasis. Comparative mitochondrial Ca2+ transport and proteomic studies on lymphoblastoid cells revealed that the [Ca2+] threshold and the cooperative activation of mitochondrial Ca2+ uptake were lost in MICU1‐deficient cells and that 39 proteins were altered in abundance. Several of those proteins are linked to mitochondrial dysfunction and/or perturbed Ca2+ homeostasis, also impacting on regular cytoskeleton (affecting Spectrin) and Golgi architecture, as well as cellular survival mechanisms.

Conclusions

Our findings (i) link dysregulation of mitochondrial Ca2+ uptake with muscle pathology (including perturbed lipid homeostasis and ER–Golgi morphology), (ii) support the concept of a functional interplay of ER–Golgi and mitochondria in lipid homeostasis and (iii) reveal the vulnerability of the cellular proteome as part of the MICU1‐related pathophysiology.
Challenging the German Empire: Strategic nationalism in Alsace‐Lorraine in the First World War
Authors: Prott Volker
Published: January 2021

This article introduces the concept of ‘strategic nationalism’ to explain the shift of national allegiance of most Alsatians and Lorrainers from Germany to France during the First World War. Combining the historiographical concept of ‘national indifference’ with rational‐choice theories of nationalism, the article examines why a growing number of local citizens came to defy the authorities' relentless demand of national loyalty. Contrary to previous studies that emphasize the dictatorial character of the regime and the passivity of local citizens, the article argues that national attitudes were shaped by strategic interests and highly responsive to shifts in state policy, regional circumstances and the course of the war. From mid‐1918, it was less escalating state repression or dormant Francophile sympathies, but half‐hearted liberalization of policy, the authorities' unfaltering insistence on national loyalty and imminent military and economic collapse that prompted people to see France as an attractive alternative to German rule.
Professional values and professional quality of life among mental health nurses: A cross‐sectional study
Authors: Başoğul Ceyda , Baysan Arabaci Leyla , Mutlu Satıl Ece , Büyükbayram Aslan Ayşe
Published: January 2021

This study aims to investigate the relationship between the professional values and professional quality of life of nurses working in mental health units. This descriptive, cross‐sectional, and correlational study was conducted with a sample of 120 nurses working in mental health units of one regional, one public, and one university hospital in western Turkey. Data were collected using an introductory information form, the Nurses Professional Values Scale‐Revised, and the Professional Quality of Life‐IV Scale. A statistically positive relationship was found between nurses' professional values, compassion satisfaction, and burnout. Nurses' professional values, education level, whether considering changing units, and allocation of time to social life were significant predictors of professional quality of life, explaining 44% of the total variance for Compassion Satisfaction and 24% for Burnout. Whether considering changing units was the most important predictor of compassion satisfaction, and truth value was the most important predictor of burnout. Nurses providing care based on professional values were found to have higher compassion satisfaction and burnout levels, and nurses with higher compassion satisfaction were found to experience less compassion fatigue.
Single tests of implantable cardioverter defibrillators can be performed in selected patients at a low risk of neuronal damage
Authors: Gestrich Christopher , Mellert Fritz , Schaefer Magdalena , Treede Hendrik , Schrickel Jan Wilko , Schacht Daniel , Thudium Marcus
Published: January 2021

Background

Defibrillator testing (DFT) is still used in selected patients to ensure adequate therapy. To do so, ventricular fibrillation is induced and terminated by the implanted cardioverter defibrillator (ICD). Studies have shown increases in neuronal damage markers without a measurable clinical effect in patients after defibrillator threshold testing with multiple shocks.

Objective

The aim of this study was to measure clinical outcomes, neuronal damage parameters (NSE and S100), and intraoperative cerebral perfusion (Doppler, near infra‐red spectroscopy [NIRS]) in patients undergoing single DFT after transvenous ICD implantation and comparing them to untested patients.

Method

We included 23 patients. Nine underwent surgery with a single DFT, 14 were not tested. Cognitive impairment was tested using the Mini‐Mental‐Status Test (MMST) and the DEMTECt 24 h prior and postsurgery. We also measured S100 and Neuron‐Specific Enolase (NSE) at these timepoints. During surgery we measured medial cerebral artery velocity and cerebral tissue oxygen saturation (rSO2).

Results

We found no significant differences between the patient groups except for a significant increase in mean arterial blood pressure and an increase in rSO2 after testing. One patient with cerebral vasculopathy had a significant increase in his NSE values without showing clinical symptoms. This patient also had low rSO2 measurements and a decrease in medial cerebral artery velocity after DFT, other than the other patients.

Conclusion

Single DFT did not lead to signs of neuronal damage or cognitive impairment except in one case with pre‐existing cerebral vasculopathy. Therefore, our results support the use of DFT in carefully selected patients.
Lead age as a predictor for failure in pediatrics and congenital heart disease
Authors: Whitehill Robert D. , Chandler Stephanie F. , DeWitt Elizabeth , Abrams Dominic J. , Walsh Edward P. , Kelleman Michael , Mah Douglas Y.
Published: January 2021

Background

Pediatric and congenital heart disease (CHD) patients have a high rate of transvenous (TV) lead failure.

Objective

To determine whether TV lead age can aid risk assessment for lead failure to guide the decision of whether a lead should be replaced or reused at the time of a generator change.

Methods

Retrospective cohort study of patients <21 years old undergoing TV device implant from 2000 to 2014 at our institution. Patient, device, and lead variables were collected. Leads were compared in groups based on how many generator changes were completed.

Results

A total of 393 leads in 257 patients met inclusion criteria, 60 leads failed (15%). Failed leads were more likely to have not yet undergone generator change (p = .048). CHD (p = .045), Tendril lead type (p = .02) and silicone insulation (p = .02) were associated with failure. In multivariate analysis, younger leads (p = .022), number of generator changes (p = .003), CHD (p = .005) and silicone insulation (p = .004) remained significant while Tendril lead type did not (p = .052). Survival curves show an early decline around 4 years.

Conclusions

Lead failure rate in pediatric and CHD patients is high. Leads that have not yet undergone a generator change were more likely to fail in this cohort. The strategy of serial replacement based on lead age needs further research to justify in this population.
Trajectory of left ventricular ejection fraction among individuals eligible for implantable cardioverter‐defibrillator
Authors: Carlson Selma , Gravely Amy , Adabag Selçuk
Published: January 2021

Objective

Examine the trajectory of left ventricular ejection fraction (EF) among patients eligible for implantable cardioverter‐defibrillator (ICD) therapy.

Background

EF is the cornerstone criterion for ICD therapy, but the risk of sudden cardiac death remains after an improvement in EF.

Methods

We examined the trajectory of EF among 1178 participants of the Sudden Cardiac Death in Heart Failure Trial (SCD‐HeFT) who had three or more assessments of EF, at least 90 days apart. A follow‐up EF > 35% or >10% absolute increase in EF from baseline were examined as the criteria for EF improvement.

Results

At first follow‐up, 381 (32%) patients had an improvement of EF to >35%. However, EF had returned back to ≤35% in 109 (27%) of these patients at second follow‐up. Similarly, 446 (38%) patients experienced a >10% improvement in EF at first follow‐up, but 109 (24%) of these had a subsequent >10% decrease in EF at the second follow‐up. Of the 32 patients with normalized EF (≥55%) at first follow‐up, 18 (56%) had a subsequent >10% decrease in EF. The fluctuation in EF was present in both ischemic and nonischemic cardiomyopathy but a higher proportion of patients with nonischemic cardiomyopathy had an improvement in EF to >35% at first follow‐up compared to those with ischemic cardiomyopathy (38% vs. 27%, p = < .0001).

Conclusion

There is substantial fluctuation of EF among patients who are eligible for ICD therapy.
Cardiac resynchronization therapy pacemaker implant in a patient with ARTO mitral device in situ
Authors: Nguyen Thomas , Williams Steven E. , Falkner Gillian , Shetty Anoop K.
Published: January 2021

The ARTO device is a percutaneous device for functional mitral regurgitation composed of a transseptal anchor and a T‐bar sitting in the coronary sinus which reduce the minor axis of the mitral valve. We present a case showing the technical feasibility of an LV lead implant in patients with an ARTO device in situ.
Elevation of vitellogenin expression in Sunn pest is associated with pre‐migration and migration phases of the life cycle
Authors: Dageri Asli , Guz Nurper , Gurkan Mehmet Oktay
Published: January 2021

Sunn pest, Eurygaster maura L. (Hemiptera: Scutelleridae), a species with an obligatory diapause, is a major destructive pest of cereal products in central Asia, Europe and North Africa. Adults feed voraciously, causing total destruction of wheat fields in just a couple of days. Insect vitellogenins (Vgs) play a major role in reproduction by supplying the resources needed for oocyte development. In this study, we identified and characterized three E. maura Vg genes (EmVgs: EmVg1, EmVg2 and EmVg3) in the cDNA library generated from the fat body of overwintering E. maura. We examined expression levels of EmVgs in the phases of the life cycle, different tissues and at different developmental stages. mRNA levels in the female adults started to increase in the pre‐migration phase and reached peak level in the adults that freshly migrated to lowlands. This pattern suggests that the elevation of EmVg expression is associated with pre‐migration and migration phases of the insect's life cycle. EmVgs were primarily expressed in the fat body, which could be a possible EmVg expression site. EmVgs were expressed throughout developmental stages, suggesting that they might be prominent for nymphal development of E. maura.
Protein deficiency during Trichinella spiralis infection impairs lung immunity against newborn larvae
Authors: Vila Cecilia C. , Saracino María P. , Lombardo Tomás , Falduto Guido H. , Díaz Mariángeles , Calcagno Marcela A. , Pallaro Anabel N. , Baldi Pablo C.
Published: January 2021

The goal of this study was to analyse the effects of a protein‐deficient (PD) diet on antibody‐dependent cell‐mediated cytotoxicity (ADCC) in vitro against newborn larvae (NBL) of Trichinella spiralis in the lungs of infected rats. Two groups of weaning Wistar rats received a PD diet (6.5% casein) and other two received a control diet (C, 20% casein). After ten days, one group of each diet was infected (PDI and CI) with muscle larvae. Lung tissue extracts (LTE) and lung cell suspension (LCS) were obtained. PDI had lower titres of anti‐NBL antibodies in LTE than CI. In ADCC assays using control cells, NBL mortality percentage was lower with LTE from PDI than LTE from CI (P < .01). In assays using control cytotoxic sera, ADCC was exerted by LCS from CI at all days post‐infection (p.i.), but only by LCS from 13 days p.i. from PDI. ADCC assays combining LTE and LCS from the same group showed a lower response for PDI than for CI (P < .0001). LCS from PDI contained lower numbers of neutrophils, eosinophils and FcεRI+ cells than CI. PD may diminish ADCC activity against T spiralis NBL in lungs through alterations in specific antibodies and effector cells.
Cocked, Locked, and Loaded: An Analysis of the Five Policy Regimes of Concealed Carry on College Campuses
Authors: LaPlant Kristina M. , Seckinger Deryl Mack , Lee Keith E. , LaPlant James T.
Published: January 2021

What are the predictors of the five types of policy regimes on campus carry across the 50 U.S. states? This study explores the roles of problem environment, gun culture, state policy liberalism, region, and racial politics to answer that research question. We argue that morality policy, the role of region in the adoption of public policy, and the southern subculture of violence are useful theoretical lenses for examining campus carry. We find that the problem environment—measured as gun murders per 100,000 population and the violent crime rate on college campuses—is negatively related to the adoption of campus carry policy regimes, while the gun culture (measured as gun purchases per capita and the total number of gun‐related interest groups) is positively related to the adoption of campus carry. State policy liberalism is a significant predictor of the type of policy regime adopted across the states, and the interaction term of percentage minority population and the South is a powerful predictor of adopting campus carry. The findings highlight the extant significance of the role of region, but it is conditioned by racial politics in the case of campus carry. Morality policy suggests that the rapid spread of concealed carry on college campuses may have hit a ceiling.

Related Articles

Butz, Adam M., Michael P. Fix, and Joshua L. Mitchell. 2015. “Policy Learning and the Diffusion of Stand‐Your‐Ground Laws.” Politics & Policy 43 (3): 347‐377. https://doi.org/10.1111/polp.12116

Joslyn, Mark R., and Donald P. Haider‐Markel. 2018. “Motivated Innumeracy: Estimating the Size of the Gun Owner Population and its Consequences for Opposition to Gun Restrictions.” Politics & Policy 46 (6): 827‐850. https://doi.org/10.1111/polp.12276

Smith‐Walter, Aaron, Holly L. Peterson, Michael D. Jones, and Ashley Nicole Reynolds Marshall. “Gun Stories: How Evidence Shapes Firearm Policy in the United States.” Politics & Policy 44 (6): 1053‐1088. https://doi.org/10.1111/polp.12187
Determinants of nutritional status during the first 1000 days of life in Lebanon: Sex of the child matters
Authors: Chehab Rana F. , Nasreddine Lara , Forman Michele R.
Published: January 2021

Background

The first 1000 days of life support child growth and long‐term health, but few studies address this period in Lebanon and the Eastern Mediterranean Region.

Objective

To examine the determinants of nutritional status among Lebanese children ≤2 years old by child's sex.

Methods

We analysed data from a nationally representative cross‐sectional survey of 466 mother‐child dyads. We classified socio‐economic, maternal, and child characteristics using a hierarchical conceptual framework into distal, intermediate, and proximal levels, respectively. Sex‐stratified weighted multiple linear regression was computed to identify the determinants of length‐for‐age z‐scores (LAZ) and weight‐for‐length z‐scores (WLZ).

Results

The mean (standard deviation) of LAZ and WLZ was −0.3 (1.6) and 0.5 (1.5) among boys and −0.1 (1.4) and 0.5 (1.0) among girls, respectively. At the distal level, maternal intermediate or high school education was associated with higher boys' LAZ (β 1.0, 95% confidence interval (CI) 0.2, 1.8), and less crowded households were associated with higher girls' LAZ (β 0.8, 95% CI 0.3, 1.4). At the intermediate level, maternal obesity was associated with lower girls' LAZ (β −0.9, 95% CI −1.4, −0.4). At the proximal level, birth length directly (β 0.1, 95% CI 0.0, 0.2) and breast‐feeding duration inversely (β −0.1, 95% CI −0.1, −0.0) associated with girls' LAZ. For WLZ, paternal attainment of university degree or technical diploma was associated with lower boys' WLZ (β −0.9, 95% CI −1.8, −0.1). Among the proximal determinants, birthweight was directly associated with boys' WLZ (β 1.2, 95% CI 0.6, 1.8), while being a third or later child was associated with lower girls' WLZ (β −0.5, 95% CI −0.8, −0.2). Child age was directly associated with WLZ among boys and girls (β 0.1, 95% CI 0.0, 0.1).

Conclusions

Nutritional status determinants differed by child's sex in Lebanon. These findings may help inform interventions to improve child growth.
In Concreto Antinomies, Predictability, and Lawmaking
Authors: Feis Guglielmo
Published: January 2021

This paper investigates whether or not cases of in concreto antinomies (ICAs for short, also called indirect antinomies, accidental antinomies, normative conflicts due to the facts, predicaments, or paranomies) can be predicted. I distinguish two main theoretical positions: “Prodetection” argues that we can predict in concreto antinomies; “unpredictability” argues that we cannot predict them.

I exemplify the two positions by relying on a disagreement found in the literature; then, after reviewing that disagreement, I (i) provide arguments for both positions; (ii) highlight the problematic issues for a definition of in concreto antinomy based on conceptual independence; (iii) point out some problems in Martínez Zorrilla’s threefold conception of normative conflicts; and (iv) advocate the need to introduce a case for “practically unpredictable” normative conflicts.
COPD: COagulation‐associated Pulmonary Disease?
Authors: Mkorombindo Takudzwa , Dransfield Mark T.
Published: January 2021

See related article
Leveraging Auxiliary Information on Marginal Distributions in Nonignorable Models for Item and Unit Nonresponse
Authors: Akande Olanrewaju , Madson Gabriel , Hillygus D. Sunshine , Reiter Jerome P.
Published: January 2021

Often, government agencies and survey organizations know the population counts or percentages for some of the variables in a survey. These may be available from auxiliary sources, for example administrative databases or other high-quality surveys. We present and illustrate a model-based framework for leveraging such auxiliary marginal information when handling unit and item nonresponse. We show how one can use the margins to specify different missingness mechanisms for each type of nonresponse. We use the framework to impute missing values in voter turnout in a subset of data from the US Current Population Survey. In doing so, we examine the sensitivity of results to different assumptions about the unit and item nonresponse.
Functional ANOVA Modelling of Pedestrian Counts on Streets in Three European Cities
Authors: Bolin David , Verendel Vilhelm , Berghauser Pont Meta , Stavroulaki Ioanna , Ivarsson Oscar , Håkansson Erik
Published: January 2021

The relation between pedestrian flows, the structure of the city and the street network is of central interest in urban research. However, studies of this have traditionally been based on small data sets and simplistic statistical methods. Because of a recent large-scale cross-country pedestrian survey, there is now enough data available to study this in greater detail than before, using modern statistical methods. We propose a functional ANOVA model to explain how the pedestrian flow for a street varies over the day based on its density type, describing the nearby buildings, and street type, describing its role in the city’s overall street network. The model is formulated and estimated in a Bayesian framework using hour-by-hour pedestrian counts from the three European cities, Amsterdam, London and Stockholm. To assess the predictive power of the model, which could be of interest when building new neighbourhoods, it is compared with four common methods from machine learning, including neural networks and random forests. The results indicate that this model works well but that there is room for improvement in capturing the variability in the data, especially between cities.
The Limits of Realism and the Proletariat on the Horizon: Fedor Reshetnikov's Where Is It Better?
Authors: STUHR‐ROMMEREIM HELEN
Published: January 2021

Nineteenth‐century Russian representations of peasants largely reflect, as Donald Fanger plainly framed it, “the changing moods and attitudes of the most influential segment of educated society,” and inform us about that society, rather than peasants themselves. There were, however, both subjects of literature and writers of it who fell between the polls of peasant and elite. Fedor Reshetnikov, the orphaned son of a postman, was such a writer, and his 1868 novel concerning ex‐peasants' rural to urban migration, Where Is It Better? (Gde luchshe?) diverges from and critiques the expectations of its audience of educated readers. Populist‐leaning critics and editors, seeking literary access to the landed peasantry, hoped that Reshetnikov would be uniquely able to bridge the distance between these educated readers and the masses. While Nikolai Nekrasov's Who Lives Well in Rus'? (1866–77) incorporates memory of Reshetnikov into a composite, symbolic character who carries out this mediating role, the author himself did not provide the mediation that was expected. Where Is It Better? instead dramatizes the failure of ex‐peasant characters to integrate into urban society. Published in the midst of debates over how to prevent the formation of an urban proletariat in Russia, Where Is It Better? makes visible a contingent of the population that political and aesthetic discussions treated as something that should not be given form. In doing so, Reshetnikov does not present a viewpoint from outside of the terms described by Fanger, but rather apprehends the limitations imposed by those terms.
On Wiener's violent oscillations, Popov's curves, and Hopf's supercritical bifurcation for a scalar heat equation
Authors: Guidotti Patrick , Merino Sandro
Published: January 2021

A parameter‐dependent perturbation of the spectrum of the scalar Laplacian is studied for a class of nonlocal and non‐self‐adjoint rank one perturbations. A detailed description of the perturbed spectrum is obtained both for Dirichlet boundary conditions on a bounded interval as well as for the problem on the full real line. The perturbation results are applied to the study of a related parameter‐dependent nonlinear and nonlocal parabolic equation. The equation models a feedback system that admits an interpretation as a thermostat device or in the context of an agent‐based price formation model for a market. The existence and the stability of periodic self‐oscillations of the related nonlinear and nonlocal heat equation that arise from a Hopf bifurcation are proved. The bifurcation and stability results are obtained both for the nonlinear parabolic equation with Dirichlet boundary conditions and for a related problem with nonlinear Neumann boundary conditions that model feedback boundary control. They follow from a Popov criterion for integral equations after reducing the stability analysis for the nonlinear parabolic equation to the study of a related nonlinear Volterra integral equation. While the problem is studied in the scalar case only, it can be extended naturally to arbitrary Euclidean dimension and to manifolds.
Hematologic evaluation of intraoperative autologous blood collection and allogeneic transfusion in cardiac surgery
Authors: Henderson Reney A. , Judd Miranda , Strauss Erik R. , Gammie James S. , Mazzeffi Michael A. , Taylor Bradley S. , Tanaka Kenichi A.
Published: January 2021

Background

Acute normovolemic hemodilution is recommended as a technique to reduce allogeneic red blood cell (RBC) transfusions in cardiac surgery, but its efficacy to reduce non‐RBC transfusion has not been consistently demonstrated. We hypothesized that intraoperative large‐volume autologous whole blood (AWB) collection and reinfusion improves viscoelastic coagulation parameters.

Study Design and Methods

Prospective observational study of cardiac surgery patients at the University of Maryland Medical Center between December 2017 and August 2019. Rotational thromboelastometry parameters were compared between AWB and control groups (n = 25 in each group) at three time points: T1, baseline; T2, on cardiopulmonary bypass (CPB) after the cross‐clamp removal; and T3, 30‐60 minutes after protamine administration. The study's primary outcomes were whole blood viscoelastic coagulation parameters that included EXTEM clotting time (CT), FIBTEM amplitude at 10 minutes, and EXTEM amplitude at 10 minutes (EXTEM‐A10). Chest tube drainage and allogeneic transfusion were secondary outcomes.

Results

Reinfusion of AWB after CPB resulted in a significantly shorter EXTEM CT; mean difference, −11.4 seconds (−21.4 to −1.4; P = .03). It also resulted in a greater percentage increase in EXTEM A10 from T2 to T3; mean difference, 7.8% (95% CI, 1.1%‐14.5%; P = .02). Statistical significance was not found in 24‐hour chest tube drainage.

Conclusion

Large‐volume AWB collection and reinfusion are feasible in selected cardiac surgical patients, and may be associated with prohemostatic effects according to thromboelastometry, warranting further investigation with a prospective randomized study.
Modified Posicast Control Design Method Based on the Parameters of a Fractional Order System
Authors: Yumuk Erhan , Güzelkaya Müjde , Eksin İbrahim
Published: January 2021

In this study, a novel design method for half-cycle and modified posicast controller structures is proposed for a class of the fractional order systems. In this method, all required design variable values, namely, the input step magnitudes and their application times are obtained as functions of fractional system parameters. Moreover, empirical formulas are obtained for the overshoot values of the compensated system with half-cycle and modified posicast controllers designed utilizing this method. The proposed design methodology has been tested via simulations and ball balancing real-time system. It is observed that the derived formulas are in coherence with outcomes of the simulation and real-time application. Furthermore, the performance of modified posicast controller designed using proposed method is much better than other posicast control method.
Slot-Die Coating Operability Window for Nanoparticle Bed Deposition in a Microscale Selective Laser Sintering Tool
Authors: Behera Dipankar , Liao Daniel , Cullinan Michael A.
Published: January 2021

This work seeks to develop a fundamental understanding of slot-die coating as a nanoparticle bed deposition mechanism for a microscale selective laser sintering (μ-SLS) process. The specific requirements of the μ-SLS process to deposit uniform sub-5 μm metal nanoparticle films while enabling high throughput fabrication make the slot-die coating process a strong candidate for layer-by-layer deposition. The key challenges of a coating system are to enable uniform nanoparticle ink deposition in an intermittent layer-by-layer manner. Identifying the experimental parameters to achieve this using a slot-die coating process is difficult. Therefore, the main contribution of this study is to develop a framework to predict the wet film thickness and onset of coating defects by simulating the experimental conditions of the μ-SLS process. The single-layer deposition characteristics and the operational window for the slot-die coating setup have been investigated through experiments and two-dimensional computational fluid dynamics simulations. The effect of coating parameters such as inlet speed, coating speed, and coating gap on the wet film thickness has been analyzed. For inlet speeds higher than the coating speed, it was found that the meniscus was susceptible to high instabilities leading to coating defects. Additionally, the study outlines the conditions for which the stability of the menisci upstream and downstream of the slot-die coater can affect the uniformity and thickness range of the coating.
Intrinsic Heat Treatment Induced Graded Surficial Microstructure and Tribological Properties of Selective Laser Melted Titanium
Authors: Kang Nan , Coniglio Nicolas , Cao Yang , Zhao Chunling , El Mansori Mohamed , Zhao Yu , Lin Xin , Coddet Christian
Published: January 2021

In the course of the selective laser melting (SLM) process, the part is built layer by layer involving partial remelting/heating of the previous layer, called as intrinsic heat treatment. Therefore, superficial properties of as-built parts are somewhat different from that of the inside of the part. In this work, the nano-tribological behavior of the commercial pure Ti (CP-Ti) sample built using SLM was investigated considering the near-surface regions with focus on the effect of intrinsic heat treatment. Microstructure and nano-testing allow identifying specific sliding behaviors in three attitude regions: (I) surface (0–50 µm), (II) subsurface (50–200 µm), and (III) inner-part (below 200 µm). The average hardness drops slightly when moving from Regions I and II (3.35 GPa) to Region III (3.09 GPa). The coefficient of friction (COF) values vary from 0.18 to 0.45 for all three regions, and the Region III presents highest worn trace width of 5.8 μm. Regions I and III promote a stick-and-slip behavior while sliding is smooth and continuous in Region II. This gradient microstructural characterization enables associating the behavior of Region II to large-sized lath martensite α′ morphology, which is different from the Regions I and III with finer microstructure. A finite element analysis (FEA) thermal model suggests that the existence of the three identified regions is the consequence of the intrinsic heat treatment induced by the SLM process, in which the remelting/heating and recrystallization have been considered as the main reasons for microstructure coarsening and refinement between Regions I and II, Regions II and III, respectively.
Neural Network for Balance of Plant SOFC-GT Actuator Control
Authors: Tsai Alex , Emami Tooran , Tucker David
Published: January 2021

This work aims to study the feasibility of using an online feedforward artificial neural network (ANN) to control various actuators in a hybrid fuel cell gas turbine (FC-GT) simulation plant. This unique facility known as Hybrid Performance, or HYPER, is housed at the US Department of Energy’s National Energy Technology Laboratory in Morgantown, WV. Using a cyber-physical approach, HYPER incorporates a high-fidelity FC model in software, which interacts with a gas turbine and corresponding balance of plant components in hardware, in real time. This methodology allows research of FC-GT operational issues as well as control application studies for such systems in a safe manner. An open loop perturbation of the FC model load current is used to retrieve target data from load bank and bypass airflow valve actuators which control turbine speed and FC cathode airflow respectively. The steady state FC anodic side fuel flow is also fed to a supervised ANN which learns the pattern of actuator response to the given FC perturbations. By mimicking the manually operated actuators, the FC solid temperature gradient is maintained within safe operating bounds. The feedforward ANN is useful for its simplicity and flexibility in controlling a variety of desired actuator responses based on input combinations. The benefits and drawbacks of using ANN’s are discussed, as well as suggestions for improvement.
LES-Verified RANS-Based Deterministic and Continuous Multiple-Objective Combustor Design Optimization
Authors: Briones Alejandro M. , Erdmann Timothy J. , Rankin Brent A.
Published: January 2021

Optimization procedures are performed using RANS models due to computational wall-clock time constraints. These trends are verified against selected LES counterpart simulations. The optimization study is performed on a subsonic small-scale cavity-stabilized combustor. Steady, compressible three-dimensional simulations are performed using a multi-phase Realizable k-ε Reynolds-averaged Navier-Stokes (RANS) approach or Dynamic Kinetic Energy Subgrid-scale LES. There are nineteen geometrical input parameters and four output parameters, viz., a pattern factor proxy (maximum exit temperature), a combustion efficiency proxy (averaged exit temperature), total pressure losses (TPL), and “melting” liner area. The RANS-based optimization with initial training sample of sixty design points leads to an optimum design point that dominates the baseline design, among other designs. The non-dominated design points release 57% of the heat inside the cavity in comparison to 43% from the baseline. Dominated combustors release as low as 23% of the heat in the cavity. The optimum, a dominated and the baseline design are compared with LES counterparts. The RANS predicted trends in terms of dominated and non-dominated design points were also confirmed by LES simulations, even though the output parameters quantitative values may differ. Discrepancies between RANS and LES appear more pronounced for the optimum design. This is attributed to the fact the LES permits pressure waves to escape the domain whereas RANS can only moderate pressure-induced disturbances. By allowing boundary-induced disturbances in the LES the flow field resembles that of RANS. Therefore, it is concluded that RANS and LES follow similar total pressure loss, pattern factor, and combustion efficiency trends as function of combustor design.
Hydrogen in Pipelines: Impact of Hydrogen Transport in Natural Gas Pipelines
Authors: Kurz Rainer , Lubomirsky Matt , Bainier Francis
Published: January 2021

The increased use of renewable energy has made the need to store electricity a central requirement. One of the concepts to address this need is to produce hydrogen from surplus electricity, and to use the existing natural gas pipeline system to transport the hydrogen. Generally, the hydrogen content in the pipeline flow would be below 20%, thus avoiding the problems of transporting and burning pure hydrogen. The natural gas – hydrogen mixtures have to be considered both from a gas transport and a gas storage perspective.

In this study, the impact of various levels of hydrogen in a pipeline system are simulated. The pipeline hydraulic simulation will provide the necessary operating conditions for the gas compressors, and the gas turbines that drive these compressors. The result of the study addresses the impact on transportation efficiency in terms of energy consumption and the emission of green house gases. Further, necessary concepts in the capability to store gas to better balance supply and demand are discussed.
Stress Rupture Behavior of Disk Superalloys Exposed to Low-Temperature Hot Corrosion Environment
Authors: Dua Dipankar , Khajavi Mohammad , White Gary , Thirumurthy Deepak , Singh Jaskirat
Published: January 2021

Siemens Energy has a large fleet of aero-derivative gas turbines. The performance and durability of these power turbines largely depend on the capability of hot section components to resist high-temperature surface attacks and to maintain their mechanical properties. Hot corrosion attack occurs due to exposure of turbine components to sulfur-bearing fuels/air together with other corrosive compounds during turbine operation. This paper investigates the impact of low-temperature hot corrosion on the stress rupture of commonly used gas turbine disk alloys, including Inconel 718, Incoloy 901, and A-286. The results indicate that Inconel 718 and Incoloy 901 maintain their creep strength advantage over A-286 in a low-temperature hot corrosion inducing environment at 1100°F. All three materials exhibited an equivalent life reduction in the corrosive environments at 1100°F. Moreover, the results demonstrate that the stress-rupture life of materials in hot-corrosion environments depends on the combined and cumulative effects of corrosion-resistant and hardening elements.
Applicability of Harmonic Balance for the Determination of Blade Stability Within the Prescribed Motion Approach
Authors: Chenaux Virginie Anne , Schuff Matthias , Quero David
Published: January 2021

To predict blade aerodynamic damping during the design phase, unsteady linearized CFD methods are commonly used as they offer a reasonable accuracy at acceptable computational costs. However, for moderate blade oscillation amplitudes, nonlinear aerodynamic effects may appear, yielding eventually an evolution into a stable, limit cycle oscillation (LCO). In the perspective of raising performance and safety, identifying such scenarios might open new development possibilities. Therefore, a valuable alternative to expensive CFD time domain methods consists in applying the nonlinear frequency domain harmonic balance (HB) approach to determine the aerodynamic response. An appropriate number of higher harmonics have to be retained depending on the severity of the aerodynamic nonlinearity under consideration. This number can be identified using either a convergence study with an increasing number of harmonics, or a direct comparison with time-domain simulations. For weak to moderate aerodynamic nonlinearities, this work proposes a guideline to determine the number of harmonics without additional, comparative simulations. First, the HB convergence properties are derived using the well-known Duffing oscillator. Next, the method is applied to a compressor rotor blade subjected to a prescribed harmonic motion for conditions with and without aerodynamic nonlinearities.
Boundary Layer Flashback Model for Hydrogen Flames in Confined Geometries Including the Effect of Adverse Pressure Gradient
Authors: Björnsson Ólafur H. , Klein Sikke A. , Tober Joeri
Published: January 2021

The combustion properties of hydrogen make premixed hydrogen-air flames very prone to boundary layer flashback. This paper describes the improvement and extension of a boundary layer flashback model from Hoferichter [1] for flames confined in burner ducts. The original model did not perform well at higher preheat temperatures and overpredicted the backpressure of the flame at flashback by 4–5x. By simplifying the Lewis number dependent flame speed computation and by applying a generalized version of Stratford’s flow separation criterion [2], the prediction accuracy is improved significantly. The effect of adverse pressure gradient flow on the flashback limits in 2° and 4° diffusers is also captured adequately by coupling the model to flow simulations and taking into account the increased flow separation tendency in diffuser flow. Future research will focus on further experimental validation and direct numerical simulations to gain better insight into the role of the quenching distance and turbulence statistics.