Stages Of Life Cycle Research Articles

ОЦІНКА ПОТОЧНОГО СТАНУ РАДІАЦІЙНОГО ЗАБРУДНЕННЯ ТЕРИТОРІЇ МАЙДАНЧИКУ УРАНОВОЇ СПАДЩИНИ КОЛИШНЬОГО ВО «ПХЗ»

The article summarizes the results of long-term radioecological monitoring of the environment radioactive state within the former 'Prydniprovsk chemical plant' and adjacent territories at the preparatory stage life cycle of uranium legacy site. Data analysis have been determined the background activity levels of natural radionuclides (in particular 238U, 226Ra, 230Th, 210Pb, 210Po) in soils, underground and surface waters, air (fall density and volume activity), exhalation of 222Rn from the soil surface and its volume activity. The results of the determined dynamics and trends in the formation of pollution of environmental elements, which form the main factors of exposure of workers and the population, are presented. Areas with elevated dose rate (≥0.5 μSv·h-1) occupy more than 30% of the entire legacy site territory. In the soil activity may be 10 to 1000 times higher than background (30-50 Bq·kg-1) and can exceed 1000 times the exemption level. In aerosols 238U and 226Ra activitis exceeding the background (0.1 µBq·m-2·s-1, 11.5 µBq·m3) by 100-200 times only during periods of earthworks, under normal conditions they are up to 1.5-2.0 times. The monthly average activity 222Rn in the air of open space are 4-5 times higher of the background (median 200±68 Bq∙m-3), in some areas they can exceed by up to 50 times. In the buildings premises on the site 222Rn can exceed the reference level (250 Bq∙m-3) by 1-5 times, and in individual basements by up to 100 times. The data analysis proves that main ways of exposure of workers are external gamma radiation, the inhalation exposure routes from aerosol pollution and the spread of OA 222Rn in the air can be significant only for workers work at the legacy site and do not pose a threat to the city's population. Radiation assessment contamination of underground and surface water showed in present conditions aquatic pathways cannot form any significant contributions to the radiation exposure dose of the public. The obtained results and data analysis of monitoring observations were used to substantiate the measures of the remediation strategy legacy site.

The Role of Peptides in Combatting HIV Infection: Applications and Insights.

Peptide-based inhibitors represent a promising approach for the treatment of HIV-1, offering a range of potential advantages, including specificity, low toxicity, and the ability to target various stages of the viral lifecycle. This review outlines the current state of research on peptide-based anti-HIV therapies, highlighting key advancements and identifying future research directions. Over the past few years, there has been significant progress in developing synthetic peptide-based drugs that target various stages of the viral life cycle, including entry and replication. These approaches aim to create effective anti-HIV therapies. Additionally, peptides have proven valuable in the development of anti-HIV vaccines. In the quest for effective HIV vaccines, discovering potent antigens and designing suitable vaccine strategies are crucial for overcoming challenges such as low immunogenicity, safety concerns, and increased viral load. Innovative strategies for vaccine development through peptide research are, therefore, a key focus area for achieving effective HIV prevention. This review aims to explore the strategies for designing peptides with anti-HIV activity and to highlight their role in advancing both therapeutic and preventive measures against HIV.

Uncovering the Motor Dynamics of Obsessive-Compulsive Rituals Through Cluster Analysis.

Rituals represent a prominent human behavior in different contexts such as daily routines, life cycle stages, and psychopathology, for example, obsessive compulsive disorder (OCD) where they are referred to as compulsions. OCD compulsions differ from habitual behaviors and stereotypies regarding their formal features: acts repetition, the addition of nonfunctional acts, and attentional focus on basic motor units. This study aims to categorize OCD compulsions based on the motor patterns of acts repetition and inclusion of nonfunctional acts. We analyzed 28 video-recorded OCD compulsions; we adopted a cluster analytic model to identify distinct patterns within the data and determine cluster characteristics. Our findings revealed a moderate negative covariance between nonfunctionality and repetitiveness, indicating that as nonfunctionality increased, repetitiveness decreased. Three distinct clusters in OCD rituals were identified according to the motor pattern: "idiosyncratic rituals," characterized by strong incorporation of nonfunctional acts; "iterative rituals" showing high repetitiveness; and "routines," with minimal repetition and limited inclusion of nonfunctional acts. These motor patterns highlight evolutionarily conserved behavioral strategies aimed at coping with conditions of environmental unpredictability. The findings might allow fine-grained discrimination of ritual compulsions and help target personalized interventions.

Maize Abiotic Stress Treatments in Controlled Environments.

Maize (Zea mays) is one of the world's most important crops, providing food for humans and livestock and serving as a bioenergy source. Climate change and the resulting abiotic stressors in the field reduce crop yields, threatening food security and the global economy. Water deficit (i.e., drought), heat, and insufficient nutrients (e.g., nitrogen and phosphorus) are major environmental stressors that affect maize yields, and impact growth and development at all stages of the plant life cycle. Understanding the biological processes underlying these responses in maize has the potential to increase yields in the face of abiotic stress. Optimizing individual or combined abiotic stress treatments in controlled environments reduces potential noise in data collection that can be present under less controlled growth conditions. Here, we describe methods and conditions for controlled abiotic stress treatments and associated controls during early vegetative growth of maize, conducted in greenhouses or growth chambers. This includes the environmental conditions, equipment, soil preparation, and intensity and duration of heat, drought, nitrogen deficiency, and phosphorous deficiency. Controlled experiments at early growth stages are informative for future in-field studies that require greater labor and inputs, saving researchers time and growing space, and thus research funds, before testing plants across later stages of development. We suggest that stress treatments be severe enough to result in a measurable phenotype, but not so severe that all plants die prior to sample collection. This protocol is designed to set important standards for replicable research in maize.

Predictability of midlatitude Rossby‐wave packets

AbstractRossby‐wave packets (RWPs) along the midlatitude jet are a fundamental ingredient of extratropical dynamics. RWPs have been linked to enhanced atmospheric predictability and the occurrence of extreme weather events. We here investigate the predictability of Northern Hemispheric RWPs as physical entities, defined by enhanced values of the Rossby‐wave envelope field. Using a catalogue of RWPs identified and tracked in reanalysis data, we analyze RWP predictability in a 19‐year period of NOAA GEFSv12 reforecasts. Our analysis adopts the so‐called distance and amplitude score (DAS), a verification metric that avoids both the double‐penalty issue of field‐based verification of coherent features and the complications of an object‐based approach. Applied to the envelope field, forecast errors defined by this metric asymptote towards saturation, but do not completely reach saturation within the 10 days lead time available to this study. The growth rate of the median DAS is highest initially and decreases with lead time. This is a nontrivial result, because the underlying envelope field largely de‐emphasizes phase information, but still exhibits very similar error‐growth characteristics to fields that contain the full phase information. Variations in RWP predictability are dominated by the stage of the RWP life cycle, with higher predictability found for the propagation stage than the onset and decay stages. In addition, RWP predictability exhibits a seasonal cycle, with higher predictability in winter than in summer. Controlling for seasonality and the stage of the life cycle, we find that (i) high‐amplitude RWPs exhibit higher predictability than low‐amplitude RWPs up to 6 days lead time and (ii) there is a general pattern of relatively high predictability over Eurasia. Finally, predictability of the propagating stage is higher if forecasts are initialized after RWP onset than if initialized before onset. In this sense, RWP onset acts as a predictability barrier to the subsequent propagation stage.

The carbon footprint of vegetable imports into Aruba: A closer look at sea and air transport

This study aimed to give insights into low-carbon vegetable import strategies for Aruba, a Dutch Caribbean island. Our selected products were potatoes, lettuce, onions, tomatoes, and green beans. The products originated from 13 different countries, and 25 product-country combinations were identified. The system boundaries were from the farm until arrival at the supermarket. We identified actual maritime transport routes, and calculated greenhouse gas (GHG) emissions of passenger aircrafts flying from Amsterdam to Aruba. Vegetables imported by air had significantly higher GHG emissions (4.2–8.3 kg CO2eq per kg) than products imported by sea (0.4–2.3 kg CO2eq per kg). GHG emissions of road transport generally contributed more than those of other life cycle stages, except when products showed a high contribution of agriculture. Although sea transport was calculated with much detail, it usually did not contribute much to the GHG emissions. We recommend Life Cycle Practitioners to consider aircraft characteristics when calculating GHG emissions of air transport, and to include the weight of the 80 kg AKE container, used for cooled airfreight, when allocating impacts between passengers and freight. For this case study, GHG emissions of specific passenger aircrafts always resulted in lower GHG emissions compared to generic calculations.

Effects of environmental factors on host-parasite interaction patterns in backyard-tethered goats of Kerala, India

The environment is the most important stratum in the epidemiological triad of a parasitic disease and any variations in the environmental factors may decide the dynamic occurrence and existence of different lifecycle stages of these parasites. The present study investigated the correlations between key biometeorological and demographical parameters with the incidence of different gastrointestinal parasites and hemoparasites among goats. Four hundred and thirty-two goats were screened for parasitic infection in a yearlong survey conducted from July 2022 to June 2023 in the Teaching Veterinary Clinical Complex, Mannuthy, Kerala, India. The weather parameters (Tmax, Tmin, RH, THI, and bright sunshine hours), air quality parameters [AQI, PM2.5, and PM10], and demographic parameters (gender and age) were recorded along with the test positivity of different categories of gastrointestinal parasites and hemoparasites in goats by routine fecal sample examination and blood smear examination, respectively. The infection level was ranked based on the severity of the infection. The mean and daily variations in biometeorological parameters were calculated and the data were statistically analyzed to figure out the pertinent correlations in host-parasite-environment interaction patterns. High levels of parasitic infections with significant month-wise variations and climate-correlated peak infection patterns were noticed. The incidence of parasites was negatively correlated to all parameters except humidity, indicating more severe parasitism during monsoon months. The significant variations in the host-parasite interaction dynamics point towards the need for detailed explorations concerning the lifecycle of each specific parasite with a focus on the possible environment-favourable and resistant lifecycle stages. Future studies may be designed from a biometeorological perspective to develop a crucial understanding of host-parasite-environment interactions in goats ensuring sustainable goat farming.

Expanding Insights: Harnessing Expansion Microscopy for Super-Resolution Analysis of HIV-1–Cell Interactions

Expansion microscopy has recently emerged as an alternative technique for achieving high-resolution imaging of biological structures. Improvements in resolution are achieved by physically expanding samples through embedding in a swellable hydrogel before microscopy. However, expansion microscopy has been rarely used in the field of virology. Here, we evaluate and characterize the ultrastructure expansion microscopy (U-ExM) protocol, which facilitates approximately four-fold sample expansion, enabling the visualization of different post-entry stages of the HIV-1 life cycle, focusing on nuclear events. Our findings demonstrate that U-ExM provides robust sample expansion and preservation across different cell types, including cell-culture-adapted and primary CD4+ T-cells as well as monocyte-derived macrophages, which are known HIV-1 reservoirs. Notably, cellular targets such as nuclear bodies and the chromatin landscape remain well preserved after expansion, allowing for detailed investigation of HIV-1–cell interactions at high resolution. Our data indicate that morphologically distinct HIV-1 capsid assemblies can be differentiated within the nuclei of infected cells and that U-ExM enables detection of targets that are masked in commonly used immunofluorescence protocols. In conclusion, we advocate for U-ExM as a valuable new tool for studying virus–host interactions with enhanced spatial resolution.

Contrasting the development of larval and adult body plans during the evolution of biphasic lifecycles in sea urchins.

Biphasic lifecycles are widespread among animals, but little is known about how the developmental transition between larvae and adults is regulated. Sea urchins are a unique system for studying this phenomenon because of the stark differences between their bilateral larval and pentaradial adult body plans. Here, we use single-cell RNA sequencing to analyze the development of Heliocidaris erythrogramma (He), a sea urchin species with an accelerated, non-feeding mode of larval development. The sequencing time course extends from embryogenesis to roughly a day before the onset of metamorphosis in He larvae, which is a period that has not been covered by previous datasets. We find that the non-feeding developmental strategy of He is associated with several changes in the specification of larval cell types compared to sea urchins with feeding larvae, such as the loss of a larva-specific skeletal cell population. Furthermore, the development of the larval and adult body plans in sea urchins may utilize largely different sets of regulatory genes. These findings lay the groundwork for extending existing developmental gene regulatory networks to cover additional stages of biphasic lifecycles.

Plasmodium falciparum protein phosphatase PP7 is required for early ring-stage development.

Plasmodium falciparum causes malaria and is responsible for more than 600,000 deaths each year. Although effective drugs are available to treat disease, the spread of drug-resistant parasites endangers their future efficacy. It is hoped that a better understanding of the biology of malaria parasites will help us to discover new drugs to tackle the resistance problem. Our work is focused on the cell signaling mechanisms that control the development of the parasite throughout its complex life cycle. All signal transduction pathways are ultimately regulated by reversible protein phosphorylation by protein kinase and protein phosphatase enzymes. In this study, we investigate the function of calcium-dependent protein phosphatase PP7 and show that it is essential for the development of ring-stage parasites following the invasion of human erythrocytes. Our results contribute to the understanding of the erythrocytic stages of the parasite life cycle that cause malaria pathology.

Can letrozole be repurposed for the treatment of visceral leishmaniasis?

Visceral leishmaniasis, caused by Leishmania infantum in New World countries, is the most serious and potentially fatal form of leishmaniasis, if left untreated. There are currently no effective prophylactic measures, and therapeutic options are limited. Therefore, we investigated whether the aromatase inhibitor letrozole (LET), which is already used to treat breast cancer, has an antileishmanial activity and/or immunomodulatory potential and therefore may be used to treat L. infantum infection. LET was active against L. infantum promastigote and amastigote life cycle stages in an in vitro infection model using human THP-1 cell-derived macrophages. In human peripheral blood leukocytes ex vivo, LET reduced the internalized forms of L. infantum by classical monocytes and activated neutrophils. Concomitantly, LET stimulated the production of IL-12/TNF-α and decreased the production of IL-10/TGF-β by peripheral blood phagocytes, while in T and B cells, it promoted the production of TNF-α/IFN-γ and decreased that of IL-10. In a murine infection model, LET significantly reduced the parasite load in the liver after just 5 days and in the spleen after 15 days. During in vivo treatment with LET, the production of TNF-α/IFN-γ also increased. In addition, the proportion of developing granulomas decreased and that of mature granulomas increased in the liver, while there was no significant change in organ architecture in the spleen. Based on these data, repositioning of LET may be promising for the treatment of visceral leishmaniasis in humans.

Optimizing germination dynamics in seven key industrial and medicinal hemp varieties through seed priming techniques: An initial study for hemp cultivation in Pakistan

Seed germination is crucial for studying factors influencing production conditions since it represents the initial physiological stage of the plant's life cycle. Hemp seeds are grown to obtain cannabinoids; however, these varieties, hybrids, and feminized seeds are costly in the market with low germination rates. Therefore, optimizing the germination of hemp seeds can play an important role in maintaining plant populations and crop establishment and can reduce seed costs. This study was aimed at evaluating the germination potential of seven hemp varieties/cultivars (Cannabis sativa L.) in response to priming with Indole Butyric Acid (IBA), moringa leaf crude extract, hydro-priming, and a control. Results showed that IBA at 1000 ppm significantly improved germination rates; while the hydro-priming exhibited the fastest germination across all varieties/cultivars. Two cultivars viz., Santhica-70 and Fedora-17 exhibited the highest germination percentages of 83% and 77%, respectively with IBA treatment; while CBD Pink Kush exhibited a germination rate of 63%. This study represents the first comprehensive investigation into seed germination and seedling growth of hemp varieties, offering insights into optimized priming agent selection for industrial and medicinal hemp crop cultivation in Pakistan, highlighting the importance of variety-specific traits and priming techniques for maximizing crop yield.

Emergent ecology in a microscale model of the surface ocean.

Microbial processes operate at the microscale, which is not resolved by existing ecosystem models. Here, we present a novel model that simulates a 1 mL three-dimensional cube using a hybrid Lagrangian-Eulerian approach, at ecologically relevant timescales. The model simulates individual microbes, including three phytoplankton size classes with healthy, senescent, and dead lifecycle stages; copiotrophic and oligotrophic heterotrophic bacteria; and dissolved organic matter at 50 µm resolution. Diffusion, shear, sedimentation, chemotaxis, and attachment processes are explicitly resolved. The emerging quantitative representation of the ecosystem shows that (1) copiotrophs grow mostly attached to eukaryotic phytoplankters and get almost all of their carbon from them vs. oligotrophs that grow on exudates and lysates of cyanobacteria; (2) contrasting diel patterns in substrate appearance in the phycosphere vs. ambient water and growth of particle-associated copiotrophs vs. free-living oligotrophs; (3) attached bacteria reduce carbon flux from the phycosphere, lowering chemotactic efficiency toward eukaryotes below that toward cyanobacteria; (4) shear reduces chemotactic efficiency and fitness of the copiotroph; and (5) the main benefit of chemotaxis is to locate attachment partners. These patterns are consistent with available observations. Our study provides insights into the microscale ecology of marine bacteria, and the open-source code is a tool for further research in this area.IMPORTANCEA large amount of global CO2 fixation is performed by marine phytoplankton, and a substantial fraction of that is released as dissolved organic carbon and further processed by heterotrophic bacteria. The interaction between phytoplankton and bacteria, i.e., the carbon flux between them, is therefore an important process in the global carbon and climate system. Some bacteria have developed specialized behavioral traits, like swimming and attachment, to increase their carbon acquisition. These interactions occur at the micrometer scale, for example, the immediate vicinity of phytoplankters (the phycosphere), but existing biogeochemical models typically only simulate down to the 1 meter vertical or ~100 kilometer horizontal scale. We present a new microscale model and use it to predict fluxes and other features in the surface ocean. The model makes important predictions about the fluxes between various types of phytoplankton and bacteria and the role of behavioral traits, and it provides a basis and tool for further research in this area.

The HSV-1 encoded CCCTC-binding factor, CTRL2, impacts the nature of viral chromatin during HSV-1 lytic infection.

HSV-1 genomes are rapidly heterochromatinized following entry by host cells to limit viral gene expression. Efficient HSV-1 genome replication requires mechanisms that de-repress chromatin associated with the viral genome. CCCTC-binding factors, or CTCF insulators play both silencing and activating roles in cellular transcriptional regulation. Importantly, the HSV-1 genome encodes several CTCF insulators that flank IE genes, implying that individual HSV-1 encoded CTCF insulators regulate IE transcription during all stages of the HSV-1 life cycle. We previously reported that the HSV-1 encoded CTCF insulator located downstream of the LAT (CTRL2) controlled IE gene silencing during latency. To further characterize the role of this insulator during the lytic infection we leveraged a ΔCTRL2 recombinant virus to show that there was a genome replication defect that stemmed from decreased IE gene expression in fibroblasts and epithelial cells at early times following initiation of infection. Further experiments indicated that the defect in gene expression resulted from chromatin inaccessibility in the absence of the insulator. To elucidate how chromatin accessibility was altered in the absence of the CTRL2 insulator, we showed that enrichment of Alpha-thalassemia/mental retardation, X-linked chromatin remodeler (ATRX), and the histone variant H3.3, both of which are known for their roles in maintaining repressive histone markers on the HSV-1 viral genome were increased on IE regions of HSV-1. Finally, both H3K27me3 and H3K9me3 repressive histone marks remained enriched by 4 hours post infection in the absence of the CTRL2 insulator, confirming that the CTRL2 insulator is required for de-repression of IE genes of viral genomes. To our knowledge these are the first data that show that a specific CTCF insulator in the HSV-1 genome (CTRL2) regulates chromatin accessibility during the lytic infection.

ВИКОРИСТАННЯ ВІДКРИТИХ ДЖЕРЕЛ ІНФОРМАЦІЇ ДЛЯ ВИВЧЕННЯ ДІЛОВОЇ РЕПУТАЦІЇ СУБ’ЄКТІВ ГОСПОДАРЮВАННЯ: ВІТЧИЗНЯНИЙ ДОСВІД

Economic transformations in the national and global economy and the spread of crisis phenomena are intensifying competition in the market. In today's environment, business entities have long realized that they cannot afford to delay and wait for the consequences when faced with a deterioration or loss of business reputation among a certain circle of contact groups. In addition, it should be borne in mind that there is a dynamic growth of the Internet audience and a clear shift of communications to the online sphere. Therefore, business reputation plays an important role in the stable position of business entities, which allows them to maintain the level of demand for their products, maintain business relations, attract investments, etc. In addition, business reputation is an important element for business entities today, as it is important primarily for society, as it is the main and impartial subject of its assessment. Business reputation is a full-fledged intangible asset, and therefore the formation, management and use of it as a tool to ensure competitive advantages in the market in a highly competitive environment is becoming increasingly important. At the same time, the operation of any business entity, from the moment of its foundation, forms its reputation in the market among buyers, suppliers, investors and other counterparties. A positive business reputation contributes to the rapid development of an enterprise by increasing the number of potential customers, increasing sales, and, consequently, the company's share in the total market capacity. Thus, the concept of "business reputation" is not abstract, as it is primarily characterized by positive effects in the course of its activities and is accompanied by the corresponding costs of its formation and maintenance at a certain level. Under such conditions, it can be argued that the development and application of effective methods of constructing reputation in accordance with the goals and objectives of reputation management is of strategic importance in the activities of a business entity. And the main task of the top management of any business entity is to form an effective mechanism for managing reputational assets at each stage of the business life cycle, which will ultimately allow achieving a competitive advantage in the market and, as a result, stable functioning in the future.

Does tax refund policy boost executive compensation?

Tax reforms have a profound impact on corporate compensation. While existing research has extensively examined the effects of tax cuts and breaks on corporate compensation, the relationship between tax refunds and executive compensation remains largely unexplored. To address this gap, this paper employs a difference-in-differences approach to investigate the causal effect of China’s value-added tax credit refund policy on executive compensation. The findings reveal that the tax refund policy increases executive compensation, primarily by enhancing net income, which lays the financial foundation for higher executive compensation. These effects also exhibit heterogeneity across corporate regions, life cycle stages, ownership structures, and executive categories. This paper is the first to explore the relationship between tax refunds and executive compensation, providing valuable insights into how external tax policies influence corporate internal incentive structures.

Tylvalosin tartrate inhibits the replication stage of the porcine reproductive and respiratory syndrome virus life cycle

The aetiological agent of porcine reproductive and respiratory syndrome, a deadly disease that affects pigs and seriously jeopardises the global swine industry, is a porcine reproductive and respiratory syndrome virus (PRRSV). Tylvalosin tartrate, which is a macrolide antibiotic, is the active ingredient in Aivlosin. In recent years, tylvalosin tartrate has widely been used to control porcine reproductive and respiratory syndrome in swine herds in China. However, whether tylvalosin tartrate has exerts anti-PRRSV effects remains controversial. In the present study, tylvalosin tartrate exhibited no effect on PRRSV susceptibility but suppressed the replication of PRRSV and the activity of infecting Marc-145 cells. Next, the relationship between the replication cycle of PRRSV and the activity of tylvalosin tartrate was further assessed. Tylvalosin tartrate did not affect the attachment and release stages of PRRSV or act during the internalisation stage of the virus in HuN4; however, contrasting effects were noted for strains CH-1a and SDVD-HN21. Tylvalosin tartrate acted on the replication stage of PRRSV and was not strain-specific in the replication stage of the PRRSV life cycle. The study findings provide an initial clarification of the inhibitory effects of tylvalosin tartrate on PRRSV, providing new insights into the treatment of PRRS.

Enhancing DevSecOps practice with Large Language Models and Security Chaos Engineering

Recently, the DevSecOps practice has improved companies’ agile production of secure software, reducing problems and improving return on investment. However, overreliance on security tools and traditional security techniques can facilitate the implementation of vulnerabilities in different stages of the software lifecycle.. Thus, this paper proposes the integration of a Large Language Model to help automate threat discovery at the design stage and Security Chaos Engineering to support the identification of security flaws that may be undetected by security tools. A specific use case is described to demonstrate how our proposal can be applied to a retail company that has the business need to produce rapidly secure software.

Life Cycle Fluoropolymer Management in Proton Exchange Membrane Electrolysis

Concerns over the life cycle impacts of fluoropolymers have led to their inclusion in broad product restriction proposals for per- and poly-fluorinated alkyl substances (PFAS), despite their non-bioavailable properties and low exposure potential in complex, durable goods such as non-consumer electrical products. Based on the hypothesis that manufacturers are most able to manage the environmental impacts of their products, practical engineering approaches to implementing life cycle fluoropolymer stewardship are evaluated to bridge the ongoing debate between precautionary and risk-based approaches to PFAS management. A life cycle thinking approach is followed that considers product design and alternatives, as well as the product life cycle stages of material sourcing, manufacturing, field deployment, and end-of-life. Over the product life cycle, the material sourcing and end-of-life stages are most impactful in minimizing potential life cycle PFAS emissions. Sourcing fluoropolymers from suppliers with fluorosurfactant emissions control and replacement minimizes the potential emissions of bio-available PFAS substances. A stack-as-service approach to electrolyzer operations ensures a takeback mechanism for the recycling of end-of-life fluoropolymer materials. Retaining electrolytic hydrogen’s license to operate results in over USD 2 of environmental and health benefits per kilogram of hydrogen produced from reduced greenhouse gas and air pollutant emissions compared to conventional hydrogen production via steam methane reforming.

Life-cycle seismic performance of bridges with thin-walled steel piers under bi-directional excitations

In corrosive environments, steel bridges demonstrate time-dependent seismic performance and varied directional responses to bi-directional excitation at different life-cycle stages. However, current seismic assessment methods for bridges have not adequately addressed the time-dependent effects of bi-directional excitation directionality on seismic responses throughout their entire life cycle. Thus, this study aims to investigate the time-varying directional effects of bi-directional seismic excitations on steel bridges with multiple parameters and to propose a method for predicting the range of critical incident angles while considering the aging effects of bridges. Initially, time-dependent functions that characterize steel corrosion are integrated into multiscale finite element models of the steel bridges to simulate corrosion progression across their life-cycle stages. Subsequently, a quantitative analysis of the bi-directional seismic response of steel bridges is conducted throughout their life cycle, accounting for the directionality of seismic excitation. Finally, a method and process for predicting the range of time-varying bi-directional critical incident angles with 95 % probability are derived by fitting the statistical probability distribution boundary values of the critical incident angle deviation index. The study's findings indicate that the aging effects of steel bridges amplify the displacement response under bi-directional seismic excitation, with the maximum displacement response difference exceeds 40 %. The service time may increase the sensitivity of steel bridges to changes in incident angles, potentially amplifying the displacement response by a factor of 1.69. The study's findings highlight the importance of considering aging effects and bi-directional excitation directionality in bridge seismic assessments.