bluuebunny/crossref_metadata_2025 huggingface dataset:
Uptake of cash benefits among children with a disability in Norway: The role of parental socioeconomic characteristics and immigrant background
Authors: Alecu Andreea Ioana , Brekke Idunn , Holmstrøm Henrik , Syse Astri
Published: October 2024

Caring for a disabled child involves both indirect and direct economic costs, which in turn may create a financial burden for the family. Using Norway as a case, we examine if public compensatory measures reach those most in need, by assessing whether socioeconomic disadvantages and immigrant background impact adversely on the uptake of a nationally available cash benefits eligible for parents caring for a child with a disability. We take advantage of national administrative register data on children with a selection of well‐defined diagnoses born between 2009 and 2017 (N = 14,469). Our results show nonnegligible, but relatively minor, social inequalities in the uptake of cash benefits related to socioeconomic and immigrant background. Our findings indicate that this state's financial support seems to reach those most in need. However, it is essential to deepen our understanding of how socioeconomic and immigrant backgrounds influence access to and utilization of municipal healthcare services. Notably, the application process for these services often involves a greater degree of discretion on the part of welfare professionals. Further research is needed to illuminate the nuanced dynamics of these factors in the context of accessing healthcare services at the local level.
Revealing the power of informal social support: Impact on rural migrants' entrepreneurial income
Authors: Wu Guanghao , Li Jiajia , Tian Yuan , Yu Jingting
Published: October 2024

Entrepreneurship is a typical socially embedded activity and informal social support reflects the functional manifestation of unique social relationships among rural migrants. Given the limited attention in existing research, we employed data from the nationally representative China Labor‐force Dynamics Survey to investigate the impact and mechanism of informal social support on rural migrants' entrepreneurial income. We found that informal social support and its sub‐dimensions (instrumental and emotional support) significantly positively affect rural migrants' entrepreneurial income. A series of endogeneity and robustness tests substantiate this conclusion. Mechanism analysis suggests that these effects occur through the enhancement of entrepreneurial passion and mental health. Furthermore, using a cutting‐edge machine learning method (generalised random forests) to determine the basis for variable selection in heterogeneity testing, the results reveal that industry and age have the highest importance. Subsequent analysis shows that the above effects were more significant among rural migrant entrepreneurs in labour‐intensive industries and the younger generation. Finally, the theoretical and practical significance of this study has been discussed.
Antibodies in breast milk: Pro‐bodies designed for healthy newborn development
Authors: Verhasselt Valerie , Tellier Julie , Carsetti Rita , Tepekule Burcu
Published: October 2024

This manuscript sheds light on the impact of maternal breast milk antibodies on infant health. Milk antibodies prepare and protect the newborn against environmental exposure, guide and regulate the offspring's immune system, and promote transgenerational adaptation of the immune system to its environment. While the transfer of IgG across the placenta ceases at birth, milk antibodies are continuously replenished by the maternal immune system. They reflect the mother's real‐time adaptation to the environment to which the infant is exposed. They cover the infant's upper respiratory and digestive mucosa and are perfectly positioned to control responses to environmental antigens and might also reach their circulation. Maternal antibodies in breast milk play a key role in the immune defense of the developing child, with a major impact on infectious disease susceptibility in both HIC and LMIC. They also influence the development of another major health burden in children—allergies. Finally, emerging evidence shows that milk antibodies also actively shape immune development. Much of this is likely to be mediated by their effect on the seeding, composition and function of the microbiota, but not only. Further understanding of the bridge that maternal antibodies provide between the child and its environment should enable the best interventions to promote healthy development.
Three‐dimensional visualization of uterine nerve fiber distribution using fluorescence micro‐optical sectioning tomography (fMOST): A pilot study
Authors: Deng Yonglan , Zhang Yirong , Gao Fei , Lin Yifeng , Li Pei , Qiu Yanjuan , Yang Lin
Published: October 2024

Study Objective

This study aimed to observe and quantitatively analyze the morphology and distribution of uterine nerve fibers using fluorescence micro‐optical sectioning tomography (fMOST). The goal was to provide an accurate morphological reference for pathological evaluations of uterine nerves.

Measurements and Main Results

Using fMOST technique, we observed and analyzed the distribution of nerve fibers within the uterus. Our findings revealed a radial dispersion of nerve fibers radiating from myometrium to endometrium. The cervix uteri region exhibited a high density of nerve fibers, displaying terminations in a flower spray pattern. In contrast, nerve fibers in corpus uteri were comparatively sparse. However, we identified a unique “vine‐like” pattern of a single nerve fiber extending from myometrium to endometrial layer in areas with concentrated nerves.

Conclusions

The fMOST technique is able to effectively elucidate the morphology and distribution of uterine nerve fibers. This method enables three‐dimensional visualization of nerves in myometrium and offers a novel approach to observe the pathological changes in uterine nerves.
Growing older, growing more diverse: Sea turtles and epibiotic cyanobacteria
Authors: Kanjer Lucija , Filek Klara , Mucko Maja , Lupić Mateja Zekan , Frleta‐Valić Maša , Gračan Romana , Bosak Sunčica
Published: October 2024

Cyanobacteria are known for forming associations with various animals, including sea turtles, yet our understanding of cyanobacteria associated with sea turtles remains limited. This study aims to address this knowledge gap by investigating the diversity of cyanobacteria in biofilm samples from loggerhead sea turtle carapaces, utilizing a 16S rRNA gene amplicon sequencing approach. The predominant cyanobacterial order identified was Nodosilineales, with the genus Rhodoploca having the highest relative abundance. Our results suggest that cyanobacterial communities become more diverse as sea turtles age, as we observed a positive correlation between community diversity and the length of a sea turtle's carapace. Since larger and older turtles predominantly utilize neritic habitats, the shift to a more diverse cyanobacterial community aligned with a change in loggerhead habitat. Our research provides detailed insights into the cyanobacterial communities associated with loggerhead sea turtles, establishing a foundation for future studies delving into this fascinating ecological relationship and its potential implications for sea turtle conservation.
Sleep in the dromedary camel: features of the ‘first night effect’
Authors: Beniaich Younes , Farsi Hicham , M'hani Mohammed El Mehdi , Piro Mohammed , Achaâban Mohamed Rachid , Challet Etienne , Pévet Paul , Satté Amal , El Allali Khalid
Published: October 2024

The ‘first night effect’ (FNE) is a well‐known phenomenon in polysomnographic (PSG) sleep studies, resulting in significant variations in the macrostructure of wakefulness and sleep states, particularly between the initial and subsequent sleep recording sessions. The FNE phenomenon during sleep has been studied in various species, revealing complex variations between several sessions of sleep recording. The present study used a non‐invasive PSG method to examine differences between various vigilance states in four adult female dromedary camels during 4 consecutive nights and days of sleep recording. The results indicate the presence of a FNE in the architecture of the dromedary camel's vigilance states. On the first night, the proportions of wakefulness and light non‐rapid eye movment (NREM) sleep (drowsiness) were higher, at a mean (standard error of the mean [SEM]) of 40.92% (0.88%) and 14.93% (0.37%), respectively; while the proportion of rumination (mean [SEM] 29.55% [0.92%]) was lower compared to consecutive nights. No FNE was found on deep NREM sleep, while night‐time REM sleep had a shorter proportion during the first night compared to subsequent consecutive nights. A significantly lower REM/total sleep time (TST) ratio was observed on the first night. Daytime comparisons did not show any significant differences for the different vigilance states. The increase in wakefulness and light NREM sleep and the reduction in REM sleep and REM/TST sleep on the first night indicate a decline in sleep quality in the dromedary camel due to the FNE. Thus, we recommend excluding from a PSG sleep study at least the first session/night of the recordings to ensure accurate results.
Demographic History and Adaptive Evolution of Indo‐Pacific Bottlenose Dolphins (Tursiops aduncus) in Western Australia
Authors: Marfurt Svenja M. , Chabanne Delphine B. H. , Wittwer Samuel , Bizzozzero Manuela R. , Allen Simon J. , Gerber Livia , Nicholson Krista , Krützen Michael
Published: October 2024

Demographic processes can substantially affect a species' response to changing ecological conditions, necessitating the combined consideration of genetic responses to environmental variables and neutral genetic variation. Using a seascape genomics approach combined with population demographic modelling, we explored the interplay of demographic and environmental factors that shaped the current population structure in Indo‐Pacific bottlenose dolphins (Tursiops aduncus) along the Western Australian coastline. We combined large‐scale environmental data gathered via remote sensing with RADseq genomic data from 133 individuals at 19 sampling sites. Using population genetic and outlier detection analyses, we identified three distinct genetic clusters, coinciding with tropical, subtropical and temperate provincial bioregions. In contrast to previous studies, our demographic models indicated that populations occupying the paleo‐shoreline split into two demographically independent lineages before the last glacial maximum (LGM). A subsequent split after the LGM 12—15 kya gave rise to the Shark Bay population, thereby creating the three currently observed clusters. Although multi‐locus heterozygosity declined from north to south, dolphins from the southernmost cluster inhabiting temperate waters had higher heterozygosity in potentially adaptive loci compared to dolphins from subtropical and tropical waters. These findings suggest ongoing adaptation to cold‐temperate waters in the southernmost cluster, possibly linked to distinct selective pressures between the different bioregions. Our study demonstrated that in the marine realm, without apparent physical boundaries, only a combined approach can fully elucidate the intricate environmental and genetic interactions shaping the evolutionary trajectory of marine mammals.
Haemoglobin Gene Repertoire in Teleost and Cichlid Fishes Shaped by Gene Duplications and Genome Rearrangements
Authors: Omelchenko Dmytro , Bitja‐Nyom Arnold Roger , Matschiner Michael , Malinsky Milan , Indermaur Adrian , Salzburger Walter , Bartoš Oldřich , Musilova Zuzana
Published: October 2024

Haemoglobin is a key molecule for oxygen transport in vertebrates. It exhibits remarkable gene diversity in teleost fishes, reflecting adaptation to various aquatic environments. In this study, we present the dynamic evolution of haemoglobin subunit genes based on a comparison of high‐quality genome assemblies of 24 vertebrate species, including 17 teleosts (of which six are cichlids). Our findings indicate that teleost genomes contain a range of haemoglobin genes, from as few as five in fugu to as many as 43 in salmon, with the latter being the largest repertoire found in vertebrates. We find evidence that the teleost ancestor had at least four Hbα and three or four Hbβ subunit genes, and that the current gene diversity emerged during teleost radiation, driven primarily by (tandem) gene duplications, genome compaction, and rearrangement dynamics. We provide insights into the genomic organisation of haemoglobin clusters in different teleost species. We further show that the evolution of paralogous rhbdf1 genes flanking both teleost clusters (LA and MN) supports the hypothesis for the origin of the LA cluster by rearrangement within teleosts, rather than by the teleost specific whole‐genome duplication. We specifically focus on cichlid fishes, where adaptation to low oxygen environment plays role in species diversification. Our analysis of six cichlid genomes, including Pungu maclareni from the Barombi Mbo crater lake, for which we sequenced a representative genome, reveals 18–32 copies of the Hb genes, and elevated rates of non‐synonymous substitutions compared to other teleosts. Overall, this work facilitates a deeper understanding of how haemoglobin genes contribute to the adaptive potential of teleosts.
The many ways toward punctuated evolution
Authors: Duran‐Nebreda Salva , Vidiella Blai , Spiridonov Andrej , Eldredge Niles , O'Brien Michael J. , Bentley R. Alexander , Valverde Sergi
Published: October 2024

Punctuated equilibria is a theory of evolution that suggests that species go through periods of stability followed by sudden changes in phenotype. This theory has been debated for decades in evolutionary biology, but recent findings of stasis and punctuated change in evolutionary systems such as tumour dynamics, viral evolution, and artificial evolution have attracted attention from a broad range of researchers. There is a risk of interpreting punctuated change from a phenomenological, or even metaphorical, standpoint and thus opening the possibility of repeating similar debates that have occurred in the past. How to translate the lessons from evolutionary models of the fossil record to explain punctuated changes in other biological scales remains an open question. To minimize confusion, we recommend that the step‐like pattern seen in many evolutionary systems be referred to as punctuated evolution rather than punctuated equilibria, which is the theory generally linked with the similar pattern in the fossil record. Punctuated evolution is a complex pattern resulting from the interaction of both external and internal eco‐evolutionary feedback. The interplay between these evolutionary drivers can help explain the history of life and the whole spectrum of evolutionary dynamics, including diversification, cyclic changes, and stability.
CuBe: a geminivirus‐based copper‐regulated expression system suitable for post‐harvest activation
Authors: Garcia‐Perez Elena , Vazquez‐Vilar Marta , Lozano‐Duran Rosa , Orzaez Diego
Published: October 2024

The growing demand for sustainable platforms for biomolecule manufacturing has fuelled the development of plant‐based production systems. Agroinfiltration, the current industry standard, offers several advantages but faces limitations for large‐scale production due to high operational costs and batch‐to‐batch variability. Alternatively, here, we describe the CuBe system, a novel bean yellow dwarf virus (BeYDV)‐derived conditional replicative expression platform stably transformed in Nicotiana benthamiana and activated by copper sulphate (CuSO4), an inexpensive and widely used agricultural input. The CuBe system utilizes a synthetic circuit of four genetic modules integrated into the plant genome: (i) a replicative vector harbouring the gene of interest (GOI) flanked by cis‐acting elements for geminiviral replication and novelly arranged to enable transgene transcription exclusively upon formation of the circular replicon, (ii) copper‐inducible Rep/RepA proteins essential for replicon formation, (iii) the yeast‐derived CUP2‐Gal4 copper‐responsive transcriptional activator for Rep/RepA expression, and (iv) a copper‐inducible Flp recombinase to minimize basal Rep/RepA expression. CuSO4 application triggers the activation of the system, leading to the formation of extrachromosomal replicons, expression of the GOI, and accumulation of the desired recombinant protein. We demonstrate the functionality of the CuBe system in N. benthamiana plants expressing high levels of eGFP and an anti‐SARS‐CoV‐2 antibody upon copper treatment. Notably, the system is functional in post‐harvest applications, a strategy with high potential impact for large‐scale biomanufacturing. This work presents the CuBe system as a promising alternative to agroinfiltration for cost‐effective and scalable production of recombinant proteins in plants.
Distributional justice and climate risk assessment: An analysis of disparities within direct and indirect risk
Authors: Anderson M. J. , Conrow L. , Hobbs M. , Paulik R. , Blackett P. , Logan T.
Published: October 2024

Climate change and natural hazard risk assessments often overlook indirect impacts, leading to a limited understanding of the full extent of risk and the disparities in its distribution across populations. This study investigates distributional justice in natural hazard impacts, exploring its critical implications for environmental justice, equity, and resilience in adaptation planning. We employ high‐resolution spatial risk assessment and origin–destination routing to analyze coastal flooding and sea‐level rise scenarios in Aotearoa New Zealand. This approach allows the assessment of both direct impacts (property exposure) and indirect impacts (physical isolation from key amenities) on residents. Indirect impacts, such as isolation and reduced access to resources, have significant adverse effects on well‐being, social cohesion, and community resilience. Including indirect impacts in risk assessments dramatically increases the overall population burden, while revealing complex effects on existing inequalities. Our analysis reveals that including indirect impacts increases the overall population burden, but the effect on inequalities varies. These inequalities can be exacerbated or attenuated depending on scale and location, underscoring the need for decision‐makers to identify these nuanced distributions and apply context‐specific frameworks when determining equitable outcomes. Our findings uncover a substantial number of previously invisible at‐risk residents—from 61,000 to 217,000 nationally in a present‐day event—and expose a shift in impact distribution toward underserved communities. As indirect risks exacerbate disparities and impede climate adaptation efforts, adopting an inclusive approach that accounts for both direct and indirect risks and their [un]equal distribution is imperative for effective and equitable decision‐making.
Nongovernmental organizations, collective payments for ecosystem services programs, and forest loss: A cross‐national analysis
Authors: McKinney Laura , Sommer Jamie M. , Shandra John M.
Published: October 2024

Objective

We evaluate the debate concerning the impact of collective nongovernmental organization payment for ecosystem services on forest loss in low‐ and middle‐income nations.

Methods

We analyze data for a sample of 79 low‐ and middle‐income nations using a two‐stage least squares regression model to address endogeneity on the payment for ecosystem services variable.

Results

We find that collective nongovernmental organization led payment for ecosystem services programs correspond to less forest loss in low‐ and middle‐income nations. We also find that agricultural exports, agricultural land area, total population growth, rural population growth, and urban population growth are related to increased forest loss.

Conclusion

We conclude that nongovernmental organizations can cooperate with Indigenous populations in low‐ and middle‐income nations to protect forests by using payment for ecosystem services programs.
Unearthing the impact of land use on deep soil carbon−an example from the southwestern Australian wheatbelt
Authors: Kierath Dan , O'Connor James , Leopold Matthias , Bolan Nanthi S.
Published: October 2024

Climate change resulting from anthropogenic greenhouse gas (GHG) emissions is both a topic that is gaining greater societal attention and an area where greater efforts are being made for their mitigation. Increasing soil organic carbon (SOC) has been proposed as one of the mechanisms through which atmospheric carbon can be sequestered and has the potential co‐benefit of also improving soil productivity. A wide range of factors have been found to influence SOC contents, especially when depth is considered, and as such regionally specific sampling is useful to understand SOC dynamics. In this study, soil samples from an agricultural property in the West Australian Wheatbelt were analysed. The samples came from four different land uses: salinity revegetation, annual grazing, forage shrub, and perennial grazing. Samples were taken at four depth intervals up to 1 m and their general characteristics as well as each of their total organic carbon, dissolved organic carbon and microbial biomass carbon values analysed. A microbial incubation experiment was conducted over 28 days to assess the stability of the soil carbon and the extent to which this depends on the soil's clay content. This study found that depth and land use were statistically significant in both SOC concentrations and SOC stability. Soil clay content was a significant factor in the stability of SOC, explaining 38% of the variation in SOC stability. Furthermore, the study reveals that excluding soil below 30 cm depth in SOC analysis can result in a global underestimation of SOC values. An understanding of this is important for wheatbelt producers to be better equipped to understand and respond to, the market pressures exerted by societies and industries to move closer to their claimed net‐zero emissions targets.
Life and repetition in Husserl's analyses from the first half of the 1920s
Authors: Rybák David
Published: October 2024

In his later writings, Husserl posits the original life of transcendental consciousness as the ultimate subject of phenomenological inquiry. Through self‐criticism in his work, Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy, Husserl realises that the transcendence of representation remains unnoticed after the transcendental reduction. Consequently, he develops the method of apodictic reduction to reveal what is apodictic in consciousness. This method specifically reveals the living presence, as well as the constitution of immanent consciousness, to which the transcendence of representation belongs. Husserl refers to this transcendence as the first transcendence, in contrast to the second transcendence of the constitution of the world. The constitution of the first transcendence is not separate from the living streaming presence but rather belongs to the life of consciousness itself. And it is only through this transcendence of representation that the identifiable (and re‐identifiable) I with its life is constituted.
Transfusion‐transmissible coinfections among US blood donors
Authors: Conti Galen , Notari Edward P. , Dodd Roger Y. , Gorlin Jed , Custer Brian , Reik Rita , Hailu Benyam , Whitaker Barbee I. , Stramer Susan L. ,   for the U.S. Transfusion‐Transmissible Infections Monitoring System (TTIMS)
Published: October 2024

Background

Transfusion‐transmissible infection (TTI) prevalence among US blood donors has been widely documented. Here we estimate the prevalence of donors presenting with ≥2 TTIs (multiple infections past or present referred to as coinfections) and describe their demographics and associations.

Methods

Data from the Transfusion‐Transmissible Infections Monitoring System were compiled for October 2020–September 2023 (3 years). Prevalence per million donations (pmd) was calculated for each TTI coinfection combination with demographic characteristics summarized. The odds of each TTI coinfection combination were estimated using logistic regression. Reactivity by NAT and/or serology (HIV, HBV, and HCV) defined donors as consensus positive (CP) for each infection while serology‐based algorithms defined syphilis CP and the subset with active syphilis infections (ASIs).

Results

About 22 million donations were included, with 212 coinfections (9.7 pmd). Around 2% of donations positive for any TTI (n = 10,516) were coinfections. Coinfection prevalence per TTI combination ranged from 0.3 pmd for HIV CP and HCV CP, to 4.3 pmd for HIV CP and syphilis CP. There were high proportions of coinfections from donors who were male, aged 25–54 years, white or black, first time, and residing in the southern US Census Region. The odds of a second TTI occurring in an individual donor with a TTI ranged from 23 (95% CI: 13, 41) times more likely for HBV CP and ASI to 395 (95% CI: 298, 524) times more likely for HIV CP and ASI.

Conclusions

Coinfections are relatively uncommon among blood donors in the United States; however, associations exist among HIV, HBV, HCV, and syphilis infections.
Part-Load Performance Analysis of a Modular Biomass Boiler With a Combined Heat and Power Industrial Rankine Cycle and Supplementary sCO2 Brayton Cycle
Authors: Haffejee Rashid A. , Rousseau Pieter , Laubscher Ryno
Published: October 2024

The addition of a supplementary high-efficiency cycle integrated with an existing steam power cycle may increase energy efficiency and net generation. In this article, part-load performance and operation of a modular biomass boiler with an existing industrial Rankine steam heat and power cycle and supplementary supercritical CO2 (sCO2) Brayton cycle are analyzed. The aim is to leverage the high efficiency of the sCO2 cycle by retrofitting sCO2 heaters in the existing biomass boiler, increasing net power output and thermal efficiency. With nominal load performance previously investigated, understanding part-load performance and operation is vital to determining cycle feasibility. A quasi-steady-state one-dimensional thermofluid network model was used to simulate the integrated cycle performance for loads ranging from 100% to 60%. The model solves the mass, energy, momentum, and species balance equations, capturing detailed component characteristics. Two control methodologies are explored for the sCO2 Brayton cycle, namely inventory control and inventory control combined with throttling valve control. Inventory control is selected as the better-performing control strategy for load following, maintaining high thermal efficiency across partial loads. At 60% load, the sCO2 compressor operates near the pseudo-critical point, leading to a sharp decrease in sCO2 cycle capacity, which requires careful management of inventory control. Two sCO2 heater configurations are investigated, namely a single convective-dominant heater, and a dual heater configuration with a radiative and a convective heater. The single heater configuration is preferred to minimize adverse impacts on the Rankine cycle superheaters.
State-Space Basins for Monopedal Jumping With Stable Landing
Authors: Upadhye Sameer A. , Yim Justin K. , Peng William Z. , Song Hyunjong , Kim Joo H.
Published: October 2024

Maintaining stability in jumping robots remains a challenge due to their hybrid dynamics. Despite recent advances, existing research lacks a clear definition and comprehensive criteria for jumping stability. To address this gap, the definition of a post-landing stable state is presented and used to formulate state-space partitions, or post-landing stable state basins, that serve as general stability criteria for flight-to-stance tasks. A hybrid-phase approach is applied to solve the flight and stance phases as separate sub-problems through analytical and optimization-based methods, subject to nonlinear system dynamics, environmental contact constraints, and task requirements. Post-landing stable state basins are constructed for a monoped jumping robot, Salto-1P, for two tasks, targeted jumping and cat-like righting, to demonstrate the use of the basins as comprehensive criteria for jumping stability. The stance-phase sub-problem solution, or landing state basin, is analyzed to determine the effect of and identify safe sets of landing state variables for balance after landing. This basin is also validated against simulated controller-specific basins of attraction. The basins obtained reveal the relationships between stability, task requirements, initial state variables such as body orientation and velocity, and landing state variables such as body angle at landing.
Modeling and Simulation of Sand Particle Trajectories and Erosion in a Transonic Fan Stage
Authors: Ghenaiet Adel
Published: October 2024

In desert regions, there is a significant presence of dust and sand particles lifted by storms and drawn into aircraft engines, resulting in considerable erosion. This numerical study investigates the dynamics of sand particles affecting the front components of a high-bypass turbofan engine (HBTFE). The components under consideration include a Pitot intake, a spinner, a fan rotor, inlet guide vanes (IGVs), and outlet guide vanes (OGVs). This research focuses on the engine's operating conditions during takeoff from a Saharan airfield. The flow field is solved separately, and the data are transferred to an in-house particle trajectory code based on the Lagrangian model. The finite element method (FEM) is used to track sand particles as they move through the mesh cells, facilitating an accurate assessment of impacts and conditions necessary for calculating erosion rates. The results obtained indicate that a significant number of sand particles frequently impact the rotor blade, from the hub to approximately 80% of its span, due to deflection by the Pitot intake lip and outer contour. The pressure side (PS) of the rotor blade experiences severe erosion, with the highest erosion rates occurring at the leading edge (LE) and toward the trailing edge (TE). At the exit of the rotor, a substantial amount of particles flows through the OGVs and erode the PS, while fewer particles from the lower sections of the fan blade pass via the IGVs to the engine's core. These findings highlight erosion-prone regions that require special protective coatings.
A Digital Engineering Analysis of an Additively-Manufactured Turbine Vane
Authors: Berdanier Reid A. , Tien Leland , Thole Karen A.
Published: October 2024

Additive manufacturing (AM) has transformed the ability to accelerate gas turbine component research and development at a fraction of the cost and time associated with conventional manufacturing. However, whereas prior works have assessed manufacturing variability in cast turbine airfoils, limited data are available to understand the impact of as-built deviations in AM turbine parts. As metal additive airfoils are becoming more prevalent in research turbine architectures, it is increasingly important to understand the effects of potential hardware deviations specific to additively-manufactured parts. With this goal in mind, the current study utilizes a digital engineering approach to evaluate the aerodynamic impact of surface deviations on a high-pressure turbine vane design created for research purposes. Reynolds-averaged Navier–Stokes-based computational fluid dynamics studies derived from structured light scans of as-built turbine vanes are used to quantify performance relative to design-intent geometries. Further computational analyses compare results from individual serialized parts with an average vane doublet geometry serving as a surrogate for the entire wheel. Particular emphasis in the study focuses on external surface defects caused by internal cooling features that are inherent through additive manufacturing and how these features can impact the vane performance. Ultimately, this study identifies specific regions of the vane that are subject to increased sensitivity, which benefits future designers intending to use AM as a tool for turbine research and development.
The Impact of Wind Exposure on Power Plant Cold Weather Readiness in Winter Storm Elliot
Authors: Moelling David , Femiana Early , Zheng Stanley
Published: October 2024

Winter Storm Elliot was a severe winter storm hitting the northeast USA from December 21 to December 26 2022. Temperatures dropped rapidly and high winds picked up. The electric power grid in the Northeast USA was stressed to the limit. According to FERC 1702 individual large electric generating plants experienced 3,565 unplanned outages, debates or failures to start. These resulted in 90500 MW of coincident outages, debates and failures to start. Penalties for failure to provide committed power were over $2 billion USD. Most if not all of these power plants had existing cold weather readiness plans that had been exercised in previous winter operations. The coincident occurrence of very cold temperatures and high wind speeds were a key factor. FERC noted that most freezing events occurred above the rated minimum operating temperature of the affected power plants. This paper will discuss the overall risks to plant operation from freezing conditions and role of high winds in exposing weak points in the plants. Examples of use of wind walls/screens to shield exposed plant components, insulation of supports and valve actuators, and periodic purge of normally stagnant water piping during wind/cold conditions will be discussed. The role of wind in preventing the refill and restart of idled steam generators will also be discussed. The impact of local screening on pipe racks and ground level equipment as modeled by CFD will be illustrated.
The Operational Stability and Energy Efficiency of Coal-Fired Power Plant Under Ultra-Low Power Load Ratio: Feedwater Preheating System Issues
Authors: Du Zeyu , Liu Ming , Yan Junjie
Published: October 2024

The world energy supply continues to evolve and adapt to low carbon and sustainable sources due to energy shortage and environmental issues. As a result, the share of renewable energy sources in the energy mix sharply increases in many countries. However, wind and photovoltaic power is intermittent, and high penetration of renewable power poses high peak shaving pressure on the power system. Therefore, the peak shaving techniques for coal-fired power plant (CFPP) should be developed, aiming to decrease the adjustable minimal power load ratio. When the coal-fired power plant operates under low load ratio, it significantly deviates from the design condition, which will affect the operational safety and economic performances. In this study, the drainage obstruction issues of the feedwater preheating system are analyzed and addressed. Off-design analysis models of coal-fired power plant are developed. Simulation results show that the feedwater preheating system increases the net energy efficiency by 2.90%, 3.11%, 2.49% under 100%, 30% and 20% power load ratio conditions, respectively. The pressure difference between adjacent regenerative heaters (RH) decreases with the load ratio, thus increasing the risk of the drainage obstruction phenomenon. Then, schemes, including the RH’s switch-off, connecting the drainage pipe to deaerator (DRTR) or condenser, or installing the drainage pump (DP) in the drainage pipe are proposed and evaluated. Scheme A connects RH2’s and RH3’s drainage pipes to the DRTR, which can improve the unit’s operational stability and energy efficiency greatly when the drainage obstruction occurs in high-pressure feedwater preheating system. Scheme B connects RH7s and RH8’s drainage pipes to the condenser and Scheme C installs DPs in RH7s and RH8’s drainage pipelines. Scheme B and Scheme C can both enhance the operational stability of low-pressure feedwater preheating system under low load ratio condition. Scheme C have better energy efficiency performance than scheme B, but with more retrofit expense on the pump purchases. Results of this study can provide some guidance for the safe operation of the feedwater preheating system.
Surrogate-Based Optimization of a Proton-Exchange Membrane Fuel Cell for Hybrid Propulsion
Authors: Chen Hao , Zaccaria Valentina , Kyprianidis Konstantinos
Published: October 2024

The use of hydrogen in transportation is considered a promising solution to reduce CO2 emissions and combat climate change. Among the various technologies, PEM fuel cells represent a consolidated choice for hydrogen propulsion given their lightweight and relatively low cost. However, despite a few cases of successful applications of PEM fuel cells in road and rail transport, there are still barriers hindering the full exploitation of this technology, especially in the aerospace sector. Research is needed to assess the long-term viability, and modeling tools are of utmost importance for this task. The highly complex architectures necessary for hybrid propulsion require new methods for design and optimization, for which accurate but computationally fast models are critical. This paper presents a new methodology of using surrogate-based optimization to assist the design of the power system for a regional electric aircraft. A multi-objective optimization framework has been developed considering the weight, and efficiency of the power system, as well as the operating current density of the fuel cell stack. A surrogate model based on Gaussian Process regression and Singular Value Decomposition is employed to reduce the computational cost. The results show that the surrogate-based optimization approach could accelerate the optimization process without significantly affecting the prediction accuracy. This approach could be used to guide the design of experiments/high-fidelity simulations for the optimal design and energy management of power systems for electric aircraft.
Steam Turbine Modernization Options for Combined Cycle Power Plants-Addressing Industry Challenges
Authors: Smiarowski Michael
Published: October 2024

The modernizations, or retrofits of steam turbines, for combined cycle power plants represents a significant opportunity in the power industry due to the phase out of coal generation and the need for dispatchable power. Many steam turbines operating in combined cycle are reaching or surpassed the 200-thousand equivalent operating hours milestone, where a steam turbine modernization would be a viable option for consideration. A large segment of the combined cycle fleet is looking to modernize their equipment to increase efficiency, reliability, and life extension. These units are also focusing on operational flexibility to better meet their demand flexibility needs with more renewables coming on-line.

This paper will outline several steam turbine modernization options available for combine cycle power plants and cite current industry challenges, such as lead-time and logistics impacts, that have made preplanning more important than ever.
Multi-Fidelity Machine Learning Analysis of Wind Patterns Around High-Rise Buildings
Authors: Mortazavian Javad , Goudarzi Navid
Published: October 2024

This study presents a multi-fidelity machine learning (ML) approach to predict the fluctuating components of surface pressure coefficients on high-rise buildings across the entire wind rose. Employing an artificial neural network (ANN), the model is trained using a combination of four Reynolds-averaged Navier-Stokes (RANS) simulations at 10°, 20°, 30°, and 40° wind directions, and two large-eddy simulations (LES) at 0° and 45° wind directions. Hyperparameter optimization, model regularization, and feature scaling were conducted to enhance the performance of the trained model and prevent overfitting. Evaluation metrics including root mean square error (RMSE) for the model prediction accuracy study and R2 for the model fit study were utilized; low RMSE and R2 > 0.8 indicated well-trained models. The optimal and regularized model achieved R2 = 0.92 with nine standardized input features. Results demonstrate the effectiveness of the multi-fidelity approach in accurately predicting wind loads across the whole wind rose, offering valuable insights for different city/community planning applications.
(Two) Wheels on the Bus: Road User Perceptions of a Bike Bus and How This Links to Addressing Global Health Challenges
Authors: Harrington Deirdre M. , Bardid Farid , Cory Katherine , Dixon James , Dodd Sarah , Ferguson Neil , Roberts Jennifer J. , Bonner James
Published: October 2024

Background: Excessive car use hampers progress toward tackling global health challenges, including climate and sustainability issues, and is linked to lower physical activity. Local communities have been developing solutions through bike buses. This paper, one of the first on bike buses, explores how a bike bus is perceived by other road and place users. Methods: An interdisciplinary survey instrument with dialogic-style questions was distributed on flyers to road and place users on 1 bike bus route including when the bike bus was passing. Responses were thematically analyzed using analytic framing to identify themes and subthemes. This paper focuses on 2 domains related to physical activity’s link to the global health challenges of climate change and sustainability issues of excess car traffic: climate actions and community-level activism. Results: Overall, 172 responses were received from 542 distributed flyers (31.8%). The climate actions domain identified a bike bus as a solution that creates a transport mode shift, reduces emissions, and improves air quality. Themes associated with community-level activism domain include perception that a bike bus is a form of activism or a protest and that it is a disruption to the status quo on the roads. Conclusions: Our findings indicate that this active mobility practice goes beyond the utility of getting children to school and being a way to promote physical activity. A bike bus is seen as local community action that could create a transport mode shift, draw attention to road space allocation, and help tackle global health challenges.
Mechanosensing by Piezo1 in gastric ghrelin cells contributes to hepatic lipid homeostasis in mice
Authors: Zhang Jinshan , Zhao Yawen , Wu Shaohong , Han Mengxue , Gao Luyang , Yang Ke , Chen Hui , Wang Cunchuan , Xu Geyang
Published: October 2024

Ghrelin is an orexigenic peptide released by gastric ghrelin cells that contributes to obesity and hepatic steatosis. The mechanosensitive ion channel Piezo1 in gastric ghrelin cells inhibits the synthesis and secretion of ghrelin in response to gastric mechanical stretch. We sought to modulate hepatic lipid metabolism by manipulating Piezo1 in gastric ghrelin cells. Mice with a ghrelin cell–specific deficiency of
Piezo1
(

Ghrl-Piezo1
−/−

) had hyperghrelinemia and hepatic steatosis when fed a low-fat or high-fat diet. In these mice, hepatic lipid accumulation was associated with changes in gene expression and in protein abundance and activity expected to increase hepatic fatty acid synthesis and decrease lipid β-oxidation. Pharmacological inhibition of the ghrelin receptor improved hepatic steatosis in

Ghrl-Piezo1
−/−

mice, thus confirming that the phenotype of these mice was due to overproduction of ghrelin caused by inactivation of Piezo1. Gastric implantation of silicone beads to induce mechanical stretch of the stomach inhibited ghrelin synthesis and secretion, thereby helping to suppress fatty liver development induced by a high-fat diet in wild-type mice but not in

Ghrl-Piezo1
−/−

mice. Our study elucidates the mechanism by which Piezo1 in gastric ghrelin cells regulate hepatic lipid accumulation, providing insights into potential treatments for fatty liver.
Supplemental Material: Translithospheric carbonatite magmatic system of the world’s largest REE deposit, Bayan Obo, China
Authors: Xue Guoqiang , Zhang Ji'en , al. et
Published: October 2024

Resistivity values of rocks, and interpretations of the low resistivity zones, plus introductions on magnetotelluric data collection, analysis, and inversion.  
Supplemental Material: From flow to furnace: Low viscosity of three-phase lavas measured at Kīlauea 2018 eruption conditions
Authors: Halverson Brenna , Whittington Alan G.
Published: October 2024

Recorded viscosity data, original high-resolution images of samples, and data analysis spreadsheets for all calculations done. Also contains full description of experimental procedures and considerations for those wishing to conduct similar experiments in future.  
Glucagon-like peptide-1 receptor agonists before upper gastrointestinal endoscopy and risk of pulmonary aspiration or discontinuation of procedure: cohort study
Authors: Alkabbani Wajd , Suissa Karine , Gu Kristine D , Cromer Sara J , Paik Julie M , Bykov Katsiaryna , Hobai Ion , Thompson Christopher C , Wexler Deborah J , Patorno Elisabetta
Published: October 2024

Objective

To assess whether use of glucagon-like peptide-1 (GLP-1) receptor agonists before upper gastrointestinal endoscopy is associated with increased risk of pulmonary aspiration or discontinuation of the procedure compared with sodium-glucose cotransporter-2 (SGLT-2) inhibitors.

Design

Cohort study.

Setting

Two deidentified US commercial healthcare databases.

Participants

43 365 adults (≥18 years) with type 2 diabetes who used a GLP-1 receptor agonist or SGLT-2 inhibitor within 30 days before upper gastrointestinal endoscopy.

Main outcome measures

The primary outcome was pulmonary aspiration on the day of or the day after endoscopy, defined using diagnostic codes. The secondary outcome was discontinuation of endoscopy. Risk ratios and corresponding 95% confidence intervals (CIs) were estimated after fine stratification weighting based on propensity score.

Results

After weighting, 24 817 adults used a GLP-1 receptor agonist (mean age 59.9 years; 63.6% female) and 18 537 used an SGLT-2 inhibitor (59.8 years; 63.7% female). Among users of GLP-1 receptor agonists and SGLT-2 inhibitors, the weighted risk per 1000 people was, respectively, 4.15 and 4.26 for pulmonary aspiration and 9.79 and 4.91 for discontinuation of endoscopy. Compared with SGLT-2 inhibitor use, GLP-1 receptor agonist use was not associated with an increased risk of pulmonary aspiration (pooled risk ratio 0.98, 95% CI 0.73 to 1.31), although it was associated with a higher risk for discontinuation of endoscopy (1.99, 1.56 to 2.53).

Conclusions

In this comparative cohort study, no increased risk of pulmonary aspiration during upper gastrointestinal endoscopy was observed among adults with type 2 diabetes using GLP-1 receptor agonists compared with SGLT-2 inhibitors within 30 days of the procedure; however, GLP-1 receptor agonists were associated with a higher risk of discontinuation of endoscopy, possibly owing to a higher risk of retained gastric content. In the absence of evidence from randomized trials, these findings could inform future practice recommendations on the preprocedural protocol for patients requiring endoscopy.