bluuebunny/crossref_metadata_2025 huggingface dataset:
Preserved pharmacokinetics and pharmacodynamics of insulin degludec and liraglutide when administered as insulin degludec/liraglutide in a Chinese population
Authors: Liu Hongzhong , Luo Bin , Chen Xia , Ingwersen Steen H. , Jia Ting , Vestergård Jacobsen Lisbeth , Hu Pei
Published: November 2021

We report the findings of a single‐dose, randomized, three‐period cross‐over, clinical trial in healthy Chinese individuals (n = 24) comparing the pharmacokinetics of insulin degludec/liraglutide (IDegLira) with its individual components. Furthermore, we report a population pharmacokinetic analysis of a 26‐week, phase III, treat‐to‐target, randomized trial of 720 Chinese individuals with type 2 diabetes. Participants were randomized to IDegLira, degludec or liraglutide, all once daily with metformin. The pharmacokinetic profiles of IDegLira were similar to its individual components. Dose proportionality was indicated for both IDegLira components. Although there were no relevant covariate effects on degludec exposure, liraglutide exposure was inversely correlated with bodyweight. In conclusion, for the Chinese population, the pharmacokinetics of the fixed‐ratio combination IDegLira is similar to that of its individual components.
Effects of heat hardening on life parameters and thermostability of Bradysia odoriphaga larva and adults
Authors: Zhu Guodong , Zhao Haipeng , Xue Ming , Qu Cheng , Liu Shouzhu
Published: November 2021

Environmental temperature is an important factor restricting insect population dynamics. Due to the ongoing global warming, interest in the impact of heat stress on insects has grown. High temperature in summer is a key barrier for Bradysia odoriphaga (Diptera: Sciaridae), a devastating vegetable pest o in China. It is well known that moderate thermal hardening can enhance the thermotolerance of many insects, which is beneficial for adaptation to environmental thermal stress. In order to determine whether heat hardening was beneficial for B. odoriphaga to adapt to high summer temperatures, we studied the biological performance, antioxidant responses and hsp70 and hsp90 expression of B. odoriphaga 4th instar larvae and adults after pre‐exposure to mild heat hardening temperatures (30–36°C). Mild heat hardening (32–36°C) enhanced the larval thermal tolerance to extreme heat stress. However, life parameters were significantly inhibited, development was delayed, longevity was shortened, and fecundity was decreased. Mild heat hardening (30–34°C) caused serious adverse effects on life parameters and less enhancement of heat resistance for 4th instar larvae. Mild heat hardening at 36°C weakened the heat tolerance of adults. The activity of four antioxidant enzymes in B. odoriphaga changed dramatically after heat hardening at 32–36°C. During recovery at 25°C, catalase (CAT), peroxidase (POD) and glutathione‐S‐transferase (GST) in tested larvae maintained successive higher activities after heat hardening. Simultaneously, the expression levels of hsp70 and hsp90 increased significantly after thermal hardening. Higher expression levels were also detected in larvae, pupae and adults after 48 hr recovery at 25°C. Overall, mild heat hardening played an important role in heat tolerance plasticity of B. odoriphaga larvae, and the antioxidant system and hsp70 and hsp90 genes were extremely relevant to this adaptation process.
Dementia diagnosis in the hospital and outcomes among patients with advanced dementia documented in the Minimum Data Set
Authors: Hua Cassandra L. , Thomas Kali S. , Bunker Jennifer N. , Gozalo Pedro L. , Bélanger Emmanuelle , Mitchell Susan L. , Teno Joan M.
Published: November 2021

Background

Individuals with dementia do not always have a diagnosis of dementia noted on their hospital claims. Whether this lack of documentation is associated with patient outcomes is unknown. We examined the association between a dementia diagnosis listed on a hospital claim and patient outcomes among individuals with a Minimum Data Set (MDS) assessment.

Methods

A retrospective cohort study was conducted using administrative claims data and nursing home MDS assessments. Hospitalized patients aged 66 and older with advanced dementia noted on an MDS assessment completed within 120 days prior to their first hospitalization in 2017 were included. Advanced dementia was defined based on an MDS diagnosis of dementia, dependency in four or more activities of daily living, and a Cognitive Function Scale score indicative of moderate to severe impairment. Multilevel regression with a random intercept at the hospital level was used to examine the relationship between documentation of dementia in inpatient hospital Medicare claims and the following patient outcomes after adjusting for patient and hospital characteristics: invasive mechanical ventilation (IMV) use, intensive care unit or coronary care unit (ICU/CCU) use, 30‐day mortality, and hospital length of stay (LOS).

Results

In 2017, among 120,989 patients with advanced dementia and a nursing home stay, 90.57% had a dementia diagnosis on their hospital claims. In adjusted models, documentation of a dementia diagnosis was associated with lower use of the ICU/CCU (adjusted odds ratio [AOR]: 0.78 [95% confidence interval 0.74, 0.81]), use of IMV (AOR: 0.50 [0.47, 0.54]), and 30‐day mortality (AOR: 0.81 [0.77, 0.85]). Patients with a dementia diagnosis had a shorter LOS.

Conclusions

Among patients with advanced dementia, those whose dementia diagnosis was documented on their inpatient hospital Medicare claim experienced lower use of ICU/CCU, use of IMV, lower 30‐day mortality, and shorter LOS than those whose diagnosis was not documented.
Decomposing the gender reservation wage gap in Italy: A regional perspective
Authors: Brown Sarah , Popli Gurleen , Sasso Alessandro
Published: November 2021

We investigate the determinants of the reservation wage gap between unemployed men and women, using data from the Italian Labour Force Survey. We conduct detailed decomposition analysis at the mean and at different percentiles of the reservation wage distribution using the Recentered Influence Function regression approach. Given the regional differences in labor market participation and employment rates across Italy, we focus on regional differences in the gender reservation wage gap. We find evidence of a positive gender reservation wage gap, which is highest in the South, with men reporting higher reservation wages across all regions and at all percentiles of the reservation wage distribution. The decomposition results suggest that, while a large part of the gender gap in reservation wages is explained by personal characteristics such as education and age, a significant portion of the gap is explained by different job preferences (especially commuting and working time preferences) between men and women. We also find evidence of differences in the relative effects of personal, household and job characteristics across regions, and at different percentiles of the reservation wage distribution.
Harmonizing Ratings From Different School Environment Assessment Methods: A Simplified Approach
Authors: Zhao Xue , Lee Rebecca E. , Ledoux Tracey A. , Hoelscher Deanna M. , McKenzie Thomas L. , O'Connor Daniel P.
Published: November 2021

Background

This study describes a method for harmonizing data collected with different tools to compute a rating of compliance with national recommendations for school physical activity (PA) and nutrition environments.

Methods

We reviewed questionnaire items from 84 elementary schools that participated in the Childhood Obesity Research Demonstration (CORD) project, which was 3 distinct childhood obesity prevention projects in 7 communities in California, Massachusetts, and Texas. Each project used tools specific to its programs, schools, and communities. While this approach increased the feasibility of data collection, it created a challenge with the need to combine data across projects. We evaluated all questionnaire items and retained only those items that assessed one or more recommendations and constructed several items to indicate compliance or noncompliance with the respective associated recommendations.

Results

Ten constructed items covered 11 of the 20 recommendations. Analysis indicated that the scores detected variability in compliance both among communities and among school within communities.

Conclusions

The scores captured differences in compliance with the national recommendations at multiple levels. Our method, designed for creating common scores, may be useful in integrated data analysis, systematic reviews, or future studies requiring harmonizing of data collected via different tools.
High sleep fragmentation parallels poor subjective sleep quality during the third wave of the Covid‐19 pandemic: An actigraphic study
Authors: Conte Francesca , De Rosa Oreste , Rescott Marissa Lynn , Arabia Teresa Pia , D’Onofrio Paolo , Lustro Alessio , Malloggi Serena , Molinaro Danila , Spagnoli Paola , Giganti Fiorenza , Barbato Giuseppe , Ficca Gianluca
Published: November 2021

Studies on sleep during the Covid‐19 pandemic have mostly been conducted during the first wave of contagion (spring 2020). To follow up on two Italian studies addressing subjective sleep features during the second wave (autumn 2020), here we assess sleep during the third wave (spring 2021) in a sample of healthy adults from Campania (Southern Italy). Actigraphic data (on 2 nights) and the Pittsburgh Sleep Quality Index were collected from 82 participants (40 F, mean age: 32.5 ± 11.5 years) from 11 March to 18 April 2021, when Campania was classified as a “red zone”, i.e. it was subjected to strict restrictions, only slightly looser than those characterizing the first national lockdown (spring 2020). Although objective sleep duration and architecture appeared in the normal range, the presence of disrupted sleep was indexed by a relevant degree of sleep fragmentation (number of awakenings ≥ 1 min: 12.7 ± 6.12; number of awakenings ≥ 5 min: 3.04 ± 1.52), paralleled by poor subjective sleep quality (Pittsburgh Sleep Quality Index global score: 5.77 ± 2.58). These data suggest that the relevant subjective sleep impairments reported during the first wave could have relied on subtle sleep disruptions that were undetected by the few objective sleep studies from the same period. Taken together with sleep data on previous phases of the pandemic, our findings show that the detrimental effects on sleep determined by the initial pandemic outbreak have not abated across the subsequent waves of contagion, and highlight the need for interventions addressing sleep health in global emergencies.
Dual attention deep learning network for automatic steel surface defect segmentation
Authors: Pan Y. , Zhang L.
Published: November 2021

A dual attention deep learning network is developed to classify three types of steel defects, locate their positions, and depict their shapes on the steel surface in an automatic and accurate manner. The novel pixel‐level detection algorithm called DAN‐DeepLabv3+ integrates a dual attention module into the DeepLabv3+ framework in pursue of more precise segmentation results. For one thing, the dual parallel attention module helps to explicitly model rich contextual dependencies over local feature representations in the spatial and channel dimensions. For another, the popular DeepLabv3+ in an encoder‐decoder architecture is useful in capturing multi‐scale contextual information and sharp object boundaries. The DAN‐DeepLabv3+ is applied to an available dataset containing 6666 images, where three types of steel defects are taken by high‐frequency cameras and have been annotated manually. Experimental results show that, compared with other deep learning models, DAN‐DeepLabv3+ based on the Xception backbone exhibits the best segmentation performance under the mean intersection over union (IoU) of 89.95% and the frequency‐weighted IoU of 97.34%. Besides, the F1‐score for the three kinds of defects can reach 86.90%, 99.20%, and 92.81%. From the comparative study, it has been found that the adoption of the dual attention module and DeepLabv3+ contributes to boosting the segmentation performance. The significance of the proposed hybrid model lies in the enhancement in accurately detecting single or multiple steel defects, which has proven to outperform other classical methods.
Imitation and culture: What gives?
Authors: Heyes Cecilia
Published: November 2021

What is the relationship between imitation and culture? This article charts how definitions of imitation have changed in the last century, distinguishes three senses of “culture” used by contemporary evolutionists (Culture1–Culture3), and summarises current disagreement about the relationship between imitation and culture. The disagreement arises from ambiguities in the distinction between imitation and emulation, and confusion between two explanatory projects—the anthropocentric project and the cultural selection project. I argue that imitation gives cultural evolution an inheritance mechanism for communicative and gestural skills (but not technological skills), and cultural selection yields the cognitive mechanisms that make imitation possible.
From cyberfascism to terrorism: On 4chan/pol/ culture and the transnational production of memetic violence
Authors: Thorleifsson Cathrine
Published: November 2021

This article examines the fascists imaginaries that are produced and circulated at 4chan /pol/. Based on analysis of memes and posts collected during a 6‐month period in 2019, it explores the diagnoses given by anonymous users to the imagining of the ultra‐nation and dehumanized others, and the prescriptions for the remedies needed to bring about its saving. It argues that the cultural practices of /pol/ where fascist fantasies of white supremacy are spread fast and anonymously in a transnational milieu through transgressive play frames are particularly powerful for the amplification of the logic of an endangered ultra‐nation that needs urgent violent defence to obtain racial palingenesis. As such cyberfascism co‐produced in a leaderless network among users scattered across continents lends itself to calls for violent action against minority communities, including terrorism.
Placing myself in a new normalized life: The process of becoming a first‐time father. A grounded theory study
Authors: Vidaurreta Marta , Lopez‐Dicastillo Olga , Serrano‐Monzó Inmaculada , Belintxon Maider , Bermejo‐Martins Elena , Mujika Agurtzane
Published: November 2021

Becoming a first‐time father is an important transition period in men's lives that is frequently accompanied by joy and happiness. Engaging fathers has a broader impact on family and community and on fathers' own well‐being. This study explores the process of men becoming first‐time fathers and the experiences and challenges involved. Seventeen interviews with men in different stages of pregnancy, childbirth, and the postpartum period were conducted. Through a grounded theory design, a novel four‐stage theoretical model emerged that represents the journey to first‐time fatherhood. These stages are beginning the journey, fatherhood in limbo, facing reality, and settling down. Participants suggested that achieving a new normality was the final stage where they finally felt located with a sense of mastery in their journey to fatherhood. The novel theoretical approach of addressing the process of men's transition allowed more complete access to their perspectives. Men's needs are different at every phase of the transition to fatherhood, and the use of these findings can help care providers in caring for every man according to the stage he is facing.
United States Healthcare Burden of Pediatric Functional Gastrointestinal Pain Disorder Hospitalizations from 2002 to 2018
Authors: Hollier John M. , Salemi Jason L. , Shulman Robert J.
Published: November 2021

Background

The healthcare burden of pediatric functional gastrointestinal pain disorders (FGIDs) is unclear. Our study aimed to characterize the burden of these hospitalizations in the United States (US).

Methods

We utilized the US National Inpatient Sample from 2002 to 2018 to capture pediatric hospitalizations (ages 4 to 18 years old) with a primary discharge diagnosis of abdominal pain, constipation, irritable bowel syndrome, dyspepsia, abdominal migraine, cyclic vomiting syndrome, or fecal incontinence. We calculated the FGID hospitalization prevalence rate, length of stay (LOS), and inflation‐adjusted costs annually and assessed for statistically significant trend changes using joinpoint analyses.

Key Results

22.3 million pediatric hospitalizations were captured, and 1 in 64 pediatric hospitalizations were attributed to a primary FGID hospitalization. The overall FGID hospitalization prevalence rate initially remained stable but decreased significantly from 2013 to 2018. Constipation and abdominal pain hospitalization rates, respectively, increased and decreased significantly over time. Constipation hospitalizations were more prevalent for younger non‐Hispanic Blacks and Hispanics. FGID hospitalization rates stratified by sex were similar. Mean LOS was 2.3 days; average LOS increased significantly from 2002 to 2013 and then stabilized. FGID hospitalization costs averaged $6,216 per admission and increased significantly for all FGIDs except dyspepsia. Endoscopic procedures were the most common interventions.

Conclusions & Inferences

FGID hospitalization prevalence rates decreased recently, possibly due to national healthcare policy implementation. Nonetheless, constipation admissions increased. LOS was stable in recent years but associated costs‐per‐hospitalization were increasing over time, probably due to endoscopic procedures. More studies are needed to explain these prevalence and cost trends.
Position guidelines and evidence base concerning determinants of childhood obesity with a European perspective
Authors: Martinez J. Alfredo , Sassi Franco , Moreno Luis A. , Tur Josep A.
Published: November 2021

Childhood obesity is one of the most pressing global public health issues, with rates increasing fastest in countries at low levels of income. Obesity occurring during childhood is likely to persist throughout the life course, and it is a cause of increased disease risk from the early years of life. This supplement is the result of collaborations involving a large and multidisciplinary group of researchers that were established in the context of the ongoing European Horizon 2020 project Science and Technology in childhood Obesity Policy (STOP). The aim, as in the entire STOP project, is to generate evidence that can support better policies to tackle the problem of childhood obesity in Europe and elsewhere. Quality of life and health well‐being concerning children needs to consider personalized, population, and planetary facets to tackle childhood obesity at early stages of life, for in‐deep phenotyping, integrating personalized medicine and precision public health interventions at global levels. This supplement contributes to this aim.
Phenotypic heterogeneity and genotypic spectrum of inborn errors of immunity identified through whole exome sequencing in a Thai patient cohort
Authors: Tengsujaritkul Maliwan , Suratannon Narissara , Ittiwut Chupong , Ittiwut Rungnapa , Chatchatee Pantipa , Suphapeetiporn Kanya , Shotelersuk Vorasuk
Published: November 2021

Background

Inborn errors of immunity (IEI) comprise more than 400 rare diseases with potential life‐threatening conditions. Clinical manifestations and genetic defects are heterogeneous and diverse among populations. Here, we aimed to characterize the clinical, immunologic, and genetic features of Thai pediatric patients with IEI. The use of whole‐exome sequencing (WES) in diagnosis and clinical decision making was also assessed.

Methods

Thirty six unrelated patients with clinical and laboratory findings consistent with IEI were recruited from January 2010 to December 2020. WES was performed to identify the underlying genetic defects.

Results

The median age of disease onset was 4 months (range: 1 month to 13 years), and 24 were male (66.7%). Recurrent sinopulmonary tract infection was the most common clinical presentation followed by septicemia and severe pneumonia. Using WES, we successfully identified the underlying genetic defects in 18 patients (50%). Of the 20 variants identified, six have not been previously described (30%). According to the International Union of Immunological Societies (IUIS), 38.9% of these detected cases (7/18) were found to harbor variants associated with genes in combined immunodeficiencies with associated or syndromic features (Class II).

Conclusion

The diagnostic yield of WES in this patient cohort was 50%. Six novel genetic variants in IEI genes were identified. The clinical usefulness of WES in IEI was demonstrated, emphasizing it as an effective diagnostic strategy in these genetically heterogeneous disorders.
Self‐reported exercise‐induced dyspnea and airways obstruction assessed by oscillometry and spirometry in adolescents
Authors: Veneroni Chiara , Pompilio Pasquale Pio , Alving Kjell , Janson Christer , Nordang Leif , Dellacà Raffaele , Johansson Henrik , Malinovschi Andrei
Published: November 2021

Background

Self‐reported exercise‐induced dyspnea (EID) is common among adolescents. Possible underlying pathologies are exercise‐induced bronchoconstriction (EIB) and laryngeal obstruction (EILO). The forced oscillation technique (FOT) may evaluate exercise‐induced changes in airway caliber.

Aim

To investigate in adolescents the relationship between EID, EIB (post‐exercise fall in forced expiratory volume in 1s (FEV1)≥10%), EILO, and post‐exercise challenge changes in FOT parameters.

Methods

One hundred and forty‐three subjects (97 with EID) of 13–15 years old underwent a standardized exercise challenge with FOT measurement and spirometry repeatedly performed between 2 and 30 min post‐exercise. EILO was studied in a subset of 123 adolescents. Subjects showing greater changes than the healthy subgroup in the modulus of the inspiratory impedance were considered FOT responders.

Results

EID‐nonEIB subjects presented similar post‐exercise changes in all FOT parameters to nonEID‐nonEIB adolescents. Changes in all FOT parameters correlated with FEV1 fall. 45 of 97 EID subjects responded neither by FEV1 nor FOT to exercise. 19 and 18 subjects responded only by FEV1 (onlyFEV1responders) or FOT (onlyFOTresponders), respectively. Only a lower baseline forced vital capacity (FVC)%predicted and a higher FEV1/FVC distinguished the onlyFEV1responders from onlyFOTresponders. FOT parameters did not present specific post‐exercise patterns in EILO subjects.

Conclusion

FOT can be used to identify post‐exercise changes in lower airway function. However, EID has a modest relation with both FEV1 and FOT responses, highlighting the need for objective testing. More research is needed to understand whether onlyFEV1responders and onlyFOTresponders represent different endotypes.
Carpetbaggers, Confederates, and Richard Nixon: The 1960 Presidential Election, Historical Memory, and the Republican Southern Strategy
Authors: Galsworthy Tim
Published: November 2021

This article investigates the Republican Party's interactions with the South during the 1960 presidential election. It argues that southern Republican growth was built on foundations laid in 1960. Furthermore, this article illustrates the crucial importance of historical memory in southern political development. It presents white southern sentiment about the Civil War and Reconstruction as a key obstacle Republicans faced, illuminating the memory‐heavy language politicians and southern supporters employed to foster desertions from the Democratic standard. By placing historical memory at the center of its analysis, this study sheds new light on the Republican “Southern Strategy” and the figures most responsible for shaping Republican fortunes in the former Confederacy.
Immune and stromal related genes in colon cancer: Analysis of tumour microenvironment based on the cancer genome atlas (TCGA) and gene expression omnibus (GEO) databases
Authors: Wu Yue , Jia Haowei , Zhou Hangyuan , Liu Xinyu , Sun Junfeng , Zhou Xiaoyan , Zhao Hongchao
Published: November 2021

The incidence of colon cancer is amongst the top three in the world. The tumour microenvironment plays an important role in the occurrence and development of colon cancer. Stromal cells and immune cells are the main components of the tumour microenvironment. Our study detected genes, which affected the infiltration of stromal, immune cells and the way they affected the prognosis of colon cancer patients. We found that the colon's immune system had a special way to affect the tumour microenvironment. Moderate infiltration of stromal and immune cells was proved to be important protective factors for colon cancer patients, which has not been found in other tumours. C3, C5, CXCL12, GNAI1, LPAR1, PENK, PYY, SAA1 and SST were the differential expression hub genes of moderate‐stromal and immune score group. They had a more significant correlation with tumour purity and infiltration of B cells, CD8+ T cells, CD4+ T cells, macrophage, neutrophil, democratic cells. The proteins encoded by C3, C5, CXCL12, GNAI1, PENK, PYY, SST were detected in colon cancer cells. These genes had the potential to become markers to predict the prognosis of patients with colon cancer.
Gut tissue‐resident memory T cells in coeliac disease
Authors: Sollid Ludvig M.
Published: November 2021

This mini‐review describes observations of the 1990ies with culturing of gluten‐specific and astrovirus‐specific CD4+ T cells from duodenal biopsies from subjects who presumably had a long time between the exposure to gluten or astrovirus antigens and the sampling of the biopsy. In these studies, it was also observed that antigen‐specific CD4+ T cells migrated out of the gut biopsies during overnight culture. The findings are suggestive of memory T cells in tissue which are resident, but which also can be mobilised on antigen stimulation. Of note, these findings were made years before the term tissue‐resident memory T cells was invoked. Since that time, many observations have accumulated on these gut T cells, particularly the gluten‐specific T cells, and we have insight into the turnover of CD4+ T cells in the gut lamina propria. These data make it evident that human antigen‐specific CD4+ T cells that can be cultured from gut biopsies indeed are bone fide tissue‐resident memory T cells.
Interest rate rules and inflation risks in a macro‐finance model
Authors: Horvath Roman , Kaszab Lorant , Marsal Ales
Published: November 2021

Long‐term bond yields contain a risk premium, an important part of which is compensation for inflation risks. The substantial increase in the Fed funds rate in the mid‐2000s did not raise long‐term US Treasury yields due to the reduction in the term premium (so‐called Greenspan conundrum) which was typically thought to be exogenous for monetary policy. We show using a New Keynesian macro‐finance model that the term premium is endogenous and is greatly influenced by the specification of the Taylor rule. Finally, we estimate our model using various specifications of Taylor rule on US data in 1961–2007 by the generalized methods of moments and evaluate the performance of our model.
Impersonals, passives, and impersonal pronouns: Lessons from Lithuanian
Authors: Šereikaitė Milena
Published: November 2021

This study examines the properties of VoiceP and impersonal pronouns by contrasting two constructions in Lithuanian: the‐ma/‐taimpersonal and the canonical passive. I argue that, while these two constructions overlap morphologically, they are syntactically distinct. The‐ma/‐taimpersonal is related to the‐no/‐toconstruction in Polish and in Ukrainian. Although it patterns with the Ukrainian‐no/‐topassive in allowing an auxiliary, it behaves like an active VoiceP with a null projected initiator in a thematic‐subject position, a pattern found in the Polish‐no/‐toimpersonal and other impersonals crosslinguistically. I show that the Lithuanian passive lacks a syntactically realized initiator and selects for a type of Voice without a specifier. I also analyze the properties of the impersonal pronoun of the‐ma/‐taimpersonal, demonstrating that it is a bare N that lacks inherently specified ɸ features (number, gender, and person) and has no case. This finding supports existing proposals that treat impersonal pronouns in different languages as defective.
Stomatal responses in grapevine become increasingly more tolerant to low water potentials throughout the growing season
Authors: Herrera Jose Carlos , Calderan Alberto , Gambetta Gregory A. , Peterlunger Enrico , Forneck Astrid , Sivilotti Paolo , Cochard Herve , Hochberg Uri
Published: November 2021

The leaf of a deciduous species completes its life cycle in a few months. During leaf maturation, osmolyte accumulation leads to a significant reduction of the turgor loss point (ΨTLP), a known marker for stomatal closure. Here we exposed two grapevine cultivars to drought at three different times during the growing season to explore if the seasonal decrease in leaf ΨTLP influences the stomatal response to drought. The results showed a significant seasonal shift in the response of stomatal conductance to stem water potential (gs~Ψstem), demonstrating that grapevines become increasingly tolerant to low Ψstem as the season progresses in coordination with the decrease in ΨTLP. We also used the SurEau hydraulic model to demonstrate a direct link between osmotic adjustment and the plasticity of gs~Ψstem. To understand the possible advantages of gs~Ψstem plasticity, we incorporated a seasonally dynamic leaf osmotic potential into the model that simulated stomatal conductance under several water availabilities and climatic scenarios. The model demonstrated that a seasonally dynamic stomatal closure threshold results in trade‐offs: it reduces the time to turgor loss under sustained long‐term drought, but increases overall gas exchange particularly under seasonal shifts in temperature and stochastic water availability. A projected hotter future is expected to lower the increase in gas exchange that plants gain from the seasonal shift in gs~Ψstem. These findings show that accounting for dynamic stomatal regulation is critical for understanding drought tolerance.
Evaluation of lymphocyte‐specific programmed cell death protein 1 receptor expression and cytokines in blood and urine in canine urothelial carcinoma patients
Authors: Pinard Christopher J. , Stegelmeier Ashley A. , Bridle Byram W. , Mutsaers Anthony J. , Wood R. Darren , Wood Geoffrey A. , Woods J. Paul , Hocker Samuel E.
Published: November 2021

Urothelial carcinoma (UC) is the most common urinary tumour in dogs. Despite a range of treatment options, prognosis remains poor in dogs. In people, breakthroughs with checkpoint inhibitors have established new standards of care for muscle‐invasive bladder cancer patients and elevated levels of programmed cell death protein 1 (PD‐1) suggest immune checkpoint blockade may be a novel target for therapy. The goal of this study was to determine if canine UC patients express elevated levels of lymphocyte‐specific PD‐1 and/or urinary cytokine biomarkers compared to healthy dogs. Paired blood and urine were evaluated in 10 canine UC patients, five cystitis patients and 10 control dogs for lymphocyte‐specific PD‐1 expression via flow cytometry and relative cytokine expression. In UC patients, PD‐1 expression was significantly elevated on CD8+ lymphocytes in urine samples. UC patients had a higher CD4:CD8 ratio in their urine compared to healthy dogs, however, there was no significant variation in the CD8:Treg ratio between any group. Cystitis patients had significantly elevated levels of CD4+ T cells, CD8+ T cells and Tregs in their blood samples compared to UC patients and healthy dogs. Cytokine analysis demonstrated significant elevations in urinary cytokines (granulocyte‐macrophage colony‐stimulating factor, interferon‐gamma [IFN‐γ], interleukin (IL)‐2, IL‐6 IL‐7, IL‐8 and IL‐15, IP‐10, KC‐like, IL‐18, monocyte chemoattractant protein‐1 and tumour necrosis factor‐alpha). Several of these cytokines have been previously correlated with both lymphocyte‐specific PD‐1 expression (IFN‐γ, IL‐2, IL‐7 and IL‐15) in muscle‐invasive urothelial carcinoma in humans. Our results provide evidence of urinary lymphocyte PD‐1 expression and future studies could elucidate whether veterinary UC patients will respond favourably to anti‐PD‐1 immune checkpoint inhibitor therapy.
Analysis on Combined Heat and Power and Combined Heat and Power Hybrid Systems for Unconventional Drilling Operations
Authors: Dranuta Diego , Johnson Derek
Published: November 2021

The United States (U.S.) has experienced a natural gas “boom” due to the development of unconventional shale plays, but well development is energy intensive. Operations use electric drilling rigs typically powered by either three high-horsepower diesel engines (HHPDE) or three dedicated natural gas engines (DNGE) and associated generators. From a first law analysis, HHPDEs peak at about 42% efficient at full load, while DNGE peak at about 30%. Most fuel energy is lost as heat rejected by the exhaust and radiators. Concurrently, during cold seasonsor or in cold regions rigs utilize boilers to provide steam throughout the rig to prevent freezing and provide comfort.

Our analysis focused on a combined heat power (CHP) approach to improve the utilization factor (UF) of fossil energy consumed during unconventional drilling operations. Engine activity, boiler fuel consumption, and exhaust gas temperatures were recorded during winter drilling of an entire well in the Marcellus shale. Four characteristic activity cycles were extracted from recorded activity to represent four energy consumption scenarios. Exhaust and jacket water heat exchangers (E-HEX, JW-HEX) were designed and simulated, and results were analyzed in 0-D models for the four case scenarios. A 584-kWh hybrid energy management system (HEMS) was also designed and simulated into the model as another method to reduce fossil energy fuel consumption during well development.

HHPDE UF improved on average from 35.7% to 55.7% if only E-HEX were used and improved to 72.7% if JW-HEX were also used. DNGE average UF increased from 19.0% to 34.9% using E-HEX only. HEMS utilization improved UF up to an average of 76.9% and 39.1% for HHPDE CHP and DNGE CHP systems, respectively.
Analysis of Premixed Laminar Combustion of Methane With Noble Gases as a Working Fluid
Authors: Baghirzade Mammadbaghir , Nasim Md Nayer , Nawaz Behlol , Aguilar Jonathan , Shahsavan Martia , Morovatiyan Mohammadrasool , Mack John Hunter
Published: November 2021

Hydrodynamic and diffusional-thermal instabilities affect the flame dynamics, which result in non-planar flame fronts with self-accelerating cellularities and wrinkles. In premixed flames, the driving mechanism for perturbations is hydrodynamic instabilities, which are associated with thermal expansion. Under high-pressure conditions, such as in spark-ignition engines, the flame curvature and morphology might be influenced by the hydrodynamic instabilities. This study focuses on the replacement of nitrogen with a noble gas (argon and krypton) as the working fluid in the premixed combustion of methane to investigate its effect on flame stability and dynamics. The utilization of noble gases can also enhance the ideal thermal efficiency of internal combustion engines due to the higher specific heat ratio they possess and may also reduce the NOx emissions markedly because of the lack of nitrogen in the working fluid. The experiments are conducted for various equivalence ratios (φ = 0.8, 1.0, 1.2) in a constant volume combustion chamber (CVCC) at atmospheric and elevated initial pressures and atmospheric temperature. As an outcome of this study, to understand the influence of krypton on methane combustion, spherically propagating flames are analyzed in terms of the laminar flame burning velocity, cellular instability, unburned gas Markstein length, and flame morphology utilizing a Z-type Schlieren optical diagnostic technique and fractal analysis, which is a promising approach to analyze flame surfaces. The fractal dimension of the flame fronts is calculated by a box-counting algorithm. The results are compared against the previously examined case studies in which argon was used as the primary working fluid.
High-Fidelity Energy Deposition Ignition Model Coupled With Flame Propagation Models at Engine-Like Flow Conditions
Authors: Kazmouz Samuel J. , Scarcelli Riccardo , Kim Joohan , Cheng Zhen , Liu Shuaishuai , Dai Meizhong , Pomraning Eric , Senecal Peter K. , Lee Seong-Young
Published: November 2021

With the heightened pressure on car manufacturers to increase the efficiency and reduce the carbon emissions of their fleets, more challenging engine operation has become a viable option. Highly dilute, boosted, and stratified charge, among others, promise engine efficiency gains and emissions reductions. At such demanding engine conditions, the spark-ignition process is a key factor for the flame initiation propagation and the combustion event. From a computational standpoint, there exists multiple spark-ignition models that perform well under conventional conditions but are not truly predictive under strenuous engine operation modes, where the underlying physics needs to be expanded. In this paper, a hybrid Lagrangian-Eulerian spark-ignition (LESI) model is coupled with different turbulence models, grid sizes, and combustion models. The ignition model, previously developed, relies on coupling Eulerian energy deposition with a Lagrangian particle evolution of the spark channel, at every time-step. The spark channel is attached to the electrodes and allowed to elongate at a speed derived from the flow velocity. The LESI model is used to simulate spark ignition in a non-quiescent crossflow environment at engine-like conditions, using CONVERGE commercial CFD solver. The results highlight the consistency, robustness, and versatility of the model in a range of engine-like setups, from typical with RANS and a larger grid size to high fidelity with LES and a finer grid size. The flame kernel growth is then evaluated against schlieren images from an optical constant volume ignition chamber with a focus on the performance of flame propagation models, such as G-equation and thickened flame model, versus the baseline well-stirred reactor model. Finally, future development details are discussed.
On-Engine Expansion Measurement of Exhaust Manifold for Calibrating Thermo-Mechanical Fatigue FEA Model
Authors: Kulkarni Girish J. , Kakde Pravin , Parekar Vinod , Mestry Kapil , Bhosle Sandeep
Published: November 2021

An attempt was made as part of this work to acquire on-engine measurements to identify how closely current Finite Element Analysis (FEA) models replicate actual on-engine exhaust manifold behavior. Further correlation study with FEA models was performed to understand and eliminate the gaps to improve the overall FEA process.

Dry cast iron exhaust manifolds experience thermo-mechanical fatigue (TMF) during engine operation. This is one of the critical failure modes. Literature is available to perform TMF assessment of exhaust manifold e.g. [1–6]. However, it is difficult to accurately predict TMF life of exhaust manifold in FEA due to dependency on multiple factors such as non-linear material behavior [3], temperature dependent material behavior, oxidation effect, creep effect, accuracy in prediction of metal temperatures and joint friction effects. Typically, non-linear material models, creep effects and oxidation effects are accounted by advanced fatigue processing software. Non-linear material models account for material and for temperature dependent non-linearity [4]. These non-linear material model and fatigue parameters are often developed using uniaxial specimen level testing. These doesn’t account for all the complexity during on-engine test due to factors such as friction and bolt loads that can influence manifold behavior. FEA processes for exhaust manifolds are seldom calibrated with on-engine measurements due to the complexity of obtaining these measurements in an environment that has severe temperatures and vibrations.

The correlation study highlighted that exhaust manifold was over constrained by excessive clamping in FEA. This raised question on the gasket coefficient of friction (COF) and working preloads. These settings were investigated to get better correlation.

Using reduced COF and non-linear material model for manifold capscrews, helped to achieve better correlation. Replacing material properties of manifold capscrews with nonlinear data provided capability to simulate localized yielding of capscrews and hence the corresponding load loss. Using these new settings for few other case studies also showed improvement in correlation of manifold warpage and thermal fatigue life prediction. Outcome of this work was a refined FEA approach which showed better FEA to Test correlation for exhaust manifold subject to thermal loading.
Investigating the Origins of Cyclic Variability in Internal Combustion Engines Using Wall-Resolved Large Eddy Simulations
Authors: Wu Sicong , Patel Saumil S. , Ameen Muhsin M.
Published: November 2021

Modern internal combustion engines (ICE) operate at the ragged edge of stable operation characterized by high cycle-to-cycle variations (CCV). A key scientific challenge for ICE is the understanding, modeling, and control of CCV in engine performance, which can contribute to partial burns, misfire, and knock. The objective of the current study is to use high-fidelity numerical simulations to improve the understanding of the causes of CCV. Nek5000, a leading high-order spectral element, open source code, is used to simulate the turbulent flow in the engine combustion chamber. Multi-cycle, wall-resolved large-eddy simulations (LES) are performed for the General Motors (GM), Transparent Combustion Chamber (TCC-III) optical engine under motored operating conditions. The mean and root-mean-square (r.m.s.) of the in-cylinder flow fields at various piston positions are validated using PIV measurements during the intake and compression strokes. The large-scale flow structures, including the swirl and tumble flow patterns, are analyzed in detail and the causes for cyclic variabilities in these flow features are explained. The energy distribution across the different scales of the flow are quantified using one-dimensional energy spectra, and the effect of the tumble breakdown process on the energy distribution is examined. The insights from the current study can help us develop improved engine designs with reduced cyclic variabilities in the in-cylinder flow leading to enhanced engine performance.
Optimization of a Marine Medium-Speed Engine With Multi-Injector System by 1D Predictive Simulation
Authors: Liu Dai , Zhang Peng , Liu Long , Xia Qian , Ma Xiuzhen
Published: November 2021

The thermal efficiency and emission of large bore marine medium-speed diesel engine are required to be improved under the stringent legislations. A multi-injector system has been proposed in order to improve the thermal efficiency and NOx emission instantaneously. However, application of the multi-injector system increased the complexity of parameter optimization and control. To develop proper control strategy of the novel multi-injector system, a 1D engine model of the original engine configurations was developed initially, including a predictive combustion model in commercial 1D simulation program (GT-Power). After calibrated by test results and literature data under various engine loads, the engine model was modified from a central single injector engine to a multi-injector engine. On the basis of a conventional direct-injection diesel engine, another two injectors were added to the cylinder as side injectors in the model. And the fundamental combustion characteristics and engine performance of the marine medium-speed diesel engine with multi-injector are investigated under various injection quantity ratio between the central injector and side injectors. The effects of injection timing and split injection are also studied by simulation. The result indicated that the effective thermal efficiency and NOx emission of the medium speed marine diesel engine are optimized instantaneously by changing the injection strategies of the central and side injectors. Finally, the preferred injection strategy is proposed by the 1D model.
Numerical Investigation of the Impact of Spray – Bowl Interaction on Thermal Efficiency of a Gasoline Compression Ignition Engine
Authors: Addepalli Srinivasa Krishna , Pamminger Michael , Scarcelli Riccardo , Wallner Thomas
Published: November 2021

Gasoline compression ignition (GCI) is a promising way to achieve high thermal efficiency and low emissions while leveraging conventional diesel engine hardware. GCI is a partially premixed combustion concept, which derives its superiority from good volatility and long ignition delay of gasoline-like fuels. The present study investigates the interaction between the piston bowl and the spray plume of a compression ignition engine that operates with a late fuel injection strategy using computational fluid dynamics (CFD) analysis. Simulations were carried out on a single cylinder of a multi-cylinder heavy-duty compression ignition engine. The engine operates at a speed of 1038 rev/min., and a compression ratio of 17. Incylinder turbulence was modelled using RNG k-ε model and the fuel spray break up was modelled using KH-RT model. A reduced chemical kinetic mechanism was used to model combustion chemistry. After validating the combustion and performance characteristics of the baseline piston against experimental results, several new piston bowl designs were generated using CAESES. Full cycle engine simulations for four selected bowl profiles were carried out. The results compare the spray-bowl interaction of the new piston bowl designs with the baseline design. It was found that the lip location and center depth of the bowl profile are the critical design parameters that influence the air utilization and heat transfer losses. The impact of spray-bowl interaction on thermal efficiency of the engine is investigated.
Estimation of Wiebe Function Parameters for Syngas and Anode Off-Gas Combustion in Spark-Ignition Engines
Authors: Yang Ruinan , Ran Zhongnan , Assanis Dimitris
Published: November 2021

Wiebe functions, analytical equations that estimate the fuel mass fraction burned (MFB) during combustion, have been effective at describing spark-ignition (SI) engine combustion using gasoline fuels. This study explores if the same methodology can be extended for SI combustion with syngas, a gaseous fuel mixture composed of H2, CO, and CO2, and anode-off gas; the latter is an exhaust gas mixture emitted from the anode of a Solid Oxide Fuel Cell, containing H2, CO, H2O, and CO2. For this study, anode off-gas is treated as a syngas fuel diluted with CO2 and vaporized water. Combustion experiments were run on a single-cylinder, research engine using syngas and anode-off gas as fuels. One single Wiebe function and three double Wiebe functions were fitted and compared with the MFB profile calculated from the experimental data. It was determined that the SI combustion process of both the syngas and the anode-off gas could be estimated using a governing Wiebe function. While the detailed double Wiebe function had the highest accuracy, a reduced double Wiebe function is capable of achieving comparable accuracy. On the other hand, a single Wiebe function is not able to fully capture the combustion process of a SI engine using syngas and anode off-gas.