Life Cycle Patterns Research Articles

Hydrological drought life-cycle: Faster onset and recovery in humid than semi-arid basins in China

The hydrological drought life-cycle begins at the onset and includes intensification and recovery stages. Previous studies have mainly considered each stage separately, so a comprehensive life-cycle pattern analysis is lacking. Moreover, differences in hydrological drought life-cycle patterns across different climatic basins still need in-depth research. This study proposed an integrated framework for analyzing the life-cycle patterns of hydrological droughts and used it to compare semi-arid and humid basins of China. The empirical analysis involved long-term (≥30 years) monthly runoff and precipitation data from six basins—three in semi-arid and three in humid zones of China. We identified the onset thresholds of hydrological drought events from the response relationship of hydrological drought to meteorological drought, considering both duration and severity thresholds. Then, using the “time–speed” process relationship, the intensification and recovery stages of hydrological drought events were quantified. Finally, the life-cycle patterns of hydrological drought in humid and semi-arid basins of China were compared. The results indicated that: (1) the proposed integrated framework, utilizing life-cycle analysis techniques to investigate the onset thresholds, intensification, and recovery of hydrological drought, provided valuable insights into their differences across different climatic basins; (2) compared to the semi-arid basins of northern China, the humid basins exhibited lower onset thresholds, slower intensification, and quicker recovery. This indicated that, in the humid basins of southern China, the onset thresholds for hydrological drought are reached rapidly after meteorological drought, followed by more gradual intensification and faster recovery stages. This underscored the importance of recognizing the distinctive life-cycle patterns of hydrological drought in different climatic zones so that tailored strategies for effective drought prevention and mitigation can be devised

Hard Ticks as Vectors: The Emerging Threat of Tick-Borne Diseases in India.

Hard ticks (Ixodidae) play a critical role in transmitting various tick-borne diseases (TBDs), posing significant global threats to human and animal health. Climatic factors influence the abundance, diversity, and vectorial capacity of tick vectors. It is imperative to have a comprehensive understanding of hard ticks, pathogens, eco-epidemiology, and the impact of climatic changes on the transmission dynamics of TBDs. The distribution and life cycle patterns of hard ticks are influenced by diverse ecological factors that, in turn, can be impacted by changes in climate, leading to the expansion of the tick vector's range and geographical distribution. Vector competence, a pivotal aspect of vectorial capacity, involves the tick's ability to acquire, maintain, and transmit pathogens. Hard ticks, by efficiently feeding on diverse hosts and manipulating their immunity through their saliva, emerge as competent vectors for various pathogens, such as viruses, parasites and bacteria. This ability significantly influences the success of pathogen transmission. Further exploration of genetic diversity, population structure, and hybrid tick vectors is crucial, as they play a substantial role in influencing vector competence and complicating the dynamics of TBDs. This comprehensive review deals with important TBDs in India and delves into a profound understanding of hard ticks as vectors, their biology, and the factors influencing their vector competence. Given that TBDs continue to pose a substantial threat to global health, the review emphasizes the urgency of investigating tick control strategies and advancing vaccine development. Special attention is given to the pivotal role of population genetics in comprehending the genetic diversity of tick populations and providing essential insights into their adaptability to environmental changes.

New perspectives on South Atlantic storm track through an automatic method for detecting extratropical cyclones' lifecycle

AbstractThis study introduces new insights into the climatology of South Atlantic (SAt) cyclones by employing a novel cyclone life cycle detection method, the CycloPhaser. Utilizing the minimum relative vorticity series and its derivative at the cyclone centre, the program effectively identifies distinct phases in the cyclone life cycle. Cyclone tracks are obtained through the analysis of relative vorticity at 850 hPa, using the ERA5 dataset. The study identified six main cyclone life cycle patterns from the analysis of 28,458 systems. The predominant cyclone type, accounting for approximately 60% of the analysed systems, exhibited a four‐phase configuration: incipient, intensification, mature and decay. Detailed statistics for each developmental phase and the overall life cycle are presented, offering valuable comparisons and new insights while corroborating previous research findings. Key genesis regions in the SAt are identified, along with track density maps that reveal distinct preferences in cyclone developmental cycle. The main outcome of this study is the demonstration that the automated classification procedure enables the analysis of cyclones' life cycles to be conducted promptly and with low computing costs, facilitating the comprehensive study of cyclone behaviour with high efficiency.

Temporal patterns and life cycle dynamics of social media user activity during disasters: A data-driven approach for effective crisis communication

Situational awareness of social media user activity during disasters is essential for effective and efficient crisis communication. Social media platforms such as Twitter and Facebook have emerged as critical channels for governments, relief agencies, and volunteer organizations to disseminate important information to the public during disasters. However, existing models are often limited to a specific disaster event, lacking a comprehensive and generalized approach. This paper introduces a novel life cycle concept to investigate the dynamics of social media engagement during multiple wildfires and bombing/shooting events in the United States. We extensively analyze millions of tweets and identify significant temporal commonalities, unveiling generic diurnal and life cycle patterns within each disaster category. This study proposes two models for the Hourly Distribution of Tweets and Daily Distribution of Tweets to explore different evolutionary stages characterizing diurnal and life cycle patterns. The hourly model accurately calculates peak engagement times for wildfire and bombing/shooting events, with peak engagement occurring between 9:00 AM and 12:00 PM. The daily models reveal that the highest diffusion rate is observed between two to four days from the wildfire formation day, while the peak engagement of a bombing/shooting event comes within the first 24 h of the incident. The findings enhance the understanding of social media dynamics during disasters and assist crisis communication agencies in developing communication strategies that ensure prompt and effective dissemination of critical information to affected populations.

Habitat shift of adult Caligus undulatus (Copepoda: Siphonostomatoida: Caligidae) from host fish to plankton in response to host behavior.

Before 2019, adults of the sea louse Caligus undulatus were reported exclusively in plankton from ocean samples worldwide and were not known to parasitize fish hosts. In 2019, the first instance of this caligid parasitizing a fish host, Japanese sardinella Sardinella zunasi, was reported in the Seto Inland Sea, Japan. The presently reported study aimed to investigate the biology and ecology of adult C. undulatus in plankton communities in the Seto Inland Sea and surrounding waters from March 2020 to November 2021. The occurrence of sea lice in plankton communities was restricted to the period of August-January, mainly between October and December with maximum plankton abundance (10.5 ind. per 1000 m3) recorded on 30 November 2020. All post-naupliar stages of C. undulatus were found on the host fish, and they represented a typical life cycle pattern known for Caligus species. The sex ratios in both planktonic and parasitic adults were not significantly different. The frequency of occurrence of planktonic and parasitic adult females with egg strings was 68 and 46%, respectively. The number of eggs per string was significantly higher in parasitic adult females (mean ± SD: 16.9 ± 8.6) than in planktonic females (10.4 ± 10.8). These data suggest that adult females were detached from their hosts and continued to produce eggs without feeding. Seasonal migration of S. zunasi to brackish water for spawning may result in the detachment of mature caligids from the host and may be effective in protecting the offspring, which are less tolerant of less brackish water.

Trace elemental and stable isotopic signatures to reconstruct the large-scale environmental connectivity of fish populations

Animal movements and connectivity across different environments constitute essential components of virtually all ecological and evolutionary processes. In the present study, we measured multiple trace-element profiles and stable isotopes to reconstruct life cycle patterns of Eleutheronema rhadinum, and patterns of connectivity among populations of E. rhadinum across 3 distinct ecoregions in the eastern China Sea. Our results indicated that E. rhadinum larvae from different regions exhibited distinct otolith core levels of trace elements and stable isotopes, serving as discriminative markers of geographical origin. We used the maximum likelihood approach and linear discriminant analysis to trace back the origins of the mixed adult fish stocks. After leaving their nursery areas, juvenile fish from colder northern regions migrated south to overwinter in the South China Sea, where they mixed with the local populations. After overwintering, the adult fish began their long journey north, with the migrating population including individuals of both East China Sea and South China Sea origins. Meanwhile, fish in the Beibu Gulf exhibited a lower degree of interaction with the South China Sea populations and minimal interaction with those in the East China Sea. Trace elements and stable isotopes revealed the spatiotemporal connectivity of E. rhadinum across the 3 different ecoregions. This study provides critical information on how marine connectivity supports temperature-mediated fish community movement patterns within coastal ecosystems.

Spatial Distribution and Influencing Factors of Single-Person Households with Social Isolation in Seoul, South Korea

Previous studies on social isolation and quality of life in single-person households (SPHs) faced limitations in identifying socially isolated groups in a citywide and detailed spatial range. The emergence of big data from various sources offers new possibilities for studying the relationship between SPHs and social isolation. This study examined the spatial distribution of SPHs at high risk of social isolation by age group and the influencing factors for Seoul, South Korea, using Seoul Citizen Life Data. Local indicators of spatial association clustering and spatial econometric models were used for the analyses. The results show, first, that SPHs are concentrated in areas with a high proportion of small- and medium-sized houses and non-apartment-type housing. Second, clear spatial distribution patterns based on life-cycle characteristics exist, with young people clustering near universities and employment centers and older people clustering in residential areas. Third, these life-cycle patterns are not as evident for SPHs with a higher risk of social isolation. Our findings show that not all SPHs can be considered a group with a high risk of social isolation, and the residential patterns of socially isolated SPHs differ from those of typical SPHs throughout their life cycle.

Effect of life cycle and venation pattern on the coordination between stomatal and vein densities of herbs.

Life cycle (annual vs perennial) and leaf venation pattern (parallel and reticular) are known to be related to water use strategies in herb species and critical adaptation to certain climatic conditions. However, the effect of these two traits and how they influence the coordination between vein density (vein length per area, VLA) and stomatal density (SD) remains unclear. In this study, we examined the leaves of 53 herb species from a subtropical botanical garden in Guangdong Province, China, including herbs with different life cycles and leaf venation patterns. We assessed 21 leaf water-related functional traits for all species, including leaf area (LA), major and minor VLA, major and minor vein diameter (VD), SD and stomatal length (SL). The results showed no significant differences in mean SD and SL between either functional group (parallel venation vs reticular venation and annual vs perennial). However, parallel vein herbs and perennial herbs displayed a significantly higher mean LA and minor VD, and lower minor VLA compared to reticular vein herbs and annual herbs, respectively. There was a linear correlation between total VLA and SD in perennial and reticular vein herbs, but this kind of correlation was not found in annual and parallel vein herbs. The major VLA and minor VD were significantly affected by the interaction between life cycle and leaf venation pattern. Our findings suggested that VLA, rather than SD, may serve as a more adaptable structure regulated by herbaceous plants to support the coordination between leaf water supply and demand in the context of different life cycles and leaf venation patterns. The results of the present study provide mechanistic understandings of functional advantages of different leaf types, which may involve in species fitness in community assembly and divergent responses to climate changes.

Life cycle and post-mortem ingrowth patterns of a leadless pacemaker system.

Life cycle and post-mortem ingrowth patterns of a leadless pacemaker system.

Life cycle and seasonal regulation of Onychogomphus forcipatus unguiculatus in the Seybouse River, Algeria (Insecta: Odonata)

Understanding the seasonal regulation and life cycle patterns of Odonata is critical to identifying the factors that influence their voltinism. While the life history and seasonal regulation of Odonata, particularly gomphids, has been studied extensively, few studies have focused on North African gomphids. This study aims to contribute to the understanding of the life cycle of Onychogomphus forcipatus unguiculatus (Vander Linden, 1823), a western Mediterranean gomphid, on the Seybouse River in northeastern Algeria and discuss its seasonal regulation. Our results imply that a generation of O. f. unguiculatus requires two years to develop. The appearance of small (F-6) larvae in early spring can be attributed to the hatching of eggs in the previous year, followed by their overwintering in interstitial habitats. This abrupt appearance of small larvae is the result of their unique life history strategy of developing and surviving in specialized habitats during winter, then continuously growing and developing. The senior cohort overlaps with its junior counterpart, overwintering primarily in instars F-1, F-2, and, to a lesser extent, F-3, before beginning to emerge in late spring and early summer. By examining the voltinism and life cycle patterns of O. f. unguiculatus, this study contributes to our understanding of the reproductive strategies and population dynamics of this western Mediterranean gomphid, as well as of factors affecting the phenology and ecology of Odonata, particularly in North Africa, and in this manner contributes to overall efforts to protect and manage freshwater ecosystems in this region.

In-house or outsourcing? The impact of remanufacturing strategies on the dynamics of component remanufacturing systems under lifecycle demand and returns

We consider a component manufacturing and remanufacturing system where, due to the end-of-life warranty, new and after-sales demand must be satisfied. Two kinds of demand exhibit different lifecycle patterns with different scales and a time lag, while a third correlated component return lifecycle with again a different lag and scale, driven by adoption of remanufacturing, is also presented. To achieve supply and demand balance during demand lifecycles, companies need a strategic decision on their remanufacturing: remanufacturing outsourcing strategy (ROS) or remanufacturing in-house strategy (RIS), yet inadequately studied from system dynamics perspective. We developed base-stock system dynamics models and analytically explored the dynamic implications of RIS and ROS remanufacturing strategies under correlated lifecycle demand and returns. Applying z-transform and discrete time simulation, we found that RIS outperforms ROS system including less peak capacity cost, less inventory holding cost and less backlog cost. Also, the bullwhip of the RIS is always less than the ROS system. However, the adoption of the RIS may result longer-lasting manufacturing production and thus lead to a higher cost: an important cost needs to be strategically considered. Thereby, from system dynamics perspective, the component manufacturer needs carefully consider trade-offs between production and inventory costs, as well as their demand lifecycle characteristics to choose the right remanufacturing strategy.

Adequate and sustainable social security for all: responses in a new context

Introduction: Social security in old age is one of the fundamental human rights. The current global tendency in population aging forces one to search for new, innovative solutions that will ensure that future pension schemes will be tailored to the generational needs and will fulfill the conditions to ensure a decent life for the elderly.Objective: The aim of this paper is to analyze the context of current efforts to ensure adequate pension scheme levels and to summarize possible solutions of this problem.Materials and methods: The author describes the demographic situation and social security in different areas of the world, focusing on a case study and analyzing existing data from international opinions.Results: Social security reforms must take full account of how social security schemes can support people particularly at risk in poverty in their working lives. It’s essential for social security to be flexible and adaptable to current life cycle patterns and individual needs.

Integrated Learning Model: A Blend of Project-Based Approach and SDLC Concepts for Software Engineering Courses, Evaluated through EUCS

Online learning and face-to-face learning are two examples of current learning models. Online learning has the advantage of time and place flexibility as it can be conducted remotely. Meanwhile, face-to-face learning excels in the teacher-student relationship as they can meet in person. However, particularly in online learning, not all subjects can be taught optimally, such as practical courses. Blended learning is one solution for a combined learning model that can leverage both online and face-to-face learning. One of the most challenging subjects in online learning is software engineering, which requires practical exercises to write application code. There are various types of blended learning models, but we propose a blended learning model specifically based on the Software Development Lifecycle (SDLC) pattern in software engineering course materials. We do this to maximize the learning process. We also integrate blended learning with a project-based concept, as this course is well-suited for project-based learning. In evaluating this model, we analyze the satisfaction level using the end-user computing satisfaction method. The sample consists of 60 students from the Computer Science program, selected using accidental sampling. The data analysis and processing methods employed in this study include t-tests, F-tests, and multiple linear regression. The research yields a satisfaction level of 71%. The results of hypothesis testing also show that the variables Ease of Use and Timeliness have a significant positive partial impact on student satisfaction.

From Field Data to Practical Knowledge: Investigating the Bioecology of the Oak Lace Bug-An Invasive Insect Species in Europe.

Corythucha arcuata, commonly known as the oak lace bug (OLB), is an insect species originally native to North America that has become an invasive species of significant concern in Europe. This invasive pest has been observed in various European countries, raising concerns about its impact on forest ecosystems. In 2015, it was first documented in Romania, further highlighting the need for research on its bioecology and life cycle. This study investigated the bioecology of the OLB in the southern region of Romania, focusing on its life cycle, development, and population dynamics. The results indicated that the OLB has three generations per year and overwinters in the adult stage in sheltered locations. Temperature significantly influenced the timing of egg hatching, nymph appearance, and adult development, with variation observed between generations. Additionally, a life table analysis provided insights into the population dynamics of the OLB in its natural environment, revealing variation in egg laying trends across generations. This research contributes to a better understanding of the OLB's bioecology and provides essential data for forest managers developing science-based management strategies to mitigate its impact. By elucidating the life cycle and development patterns of the OLB in southern Romania, this study aids in the development of predictive models and life tables tailored to the region. These findings empower forest managers with the knowledge needed to make informed decisions for effective OLB management, ultimately preserving the health of forest ecosystems.

Aparecium: understanding and detecting scam behaviors on Ethereum via biased random walk

Ethereum’s high attention, rich business, certain anonymity, and untraceability have attracted a group of attackers. Cybercrime on it has become increasingly rampant, among which scam behavior is convenient, cryptic, antagonistic and resulting in large economic losses. So we consider the scam behavior on Ethereum and investigate it at the node interaction level. Based on the life cycle and risk identification points we found, we propose an automatic detection model named Aparecium. First, a graph generation method which focus on the scam life cycle is adopted to mitigate the sparsity of the scam behaviors. Second, the life cycle patterns are delicate modeled because of the crypticity and antagonism of Ethereum scam behaviors. Conducting experiments in the wild Ethereum datasets, we prove Aparecium is effective which the precision, recall and F1-score achieve at 0.977, 0.957 and 0.967 respectively.

Life Cycle and Damage Patterns of Tea Mosquito Bug (Helopeltis theivora Waterhouse), a Newly Recorded Pest on Arabica coff ee in Northern Thailand

The symptoms of “shot hole leaves” and “excess bud growth” in Arabica coffee have signifi cantly increased in northern Thailand since 2017, resulting in the death of shoots and reduced fl owering, ultimately leading to yield loss. This study investigates whether the “shot hole leaves” symptom is caused by the tea mosquito bug (Helopeltis theivora Waterhouse) (Hemiptera: Heteroptera: Miridae) by rearing tea mosquito bugs with coffee and reproducing the same symptoms under laboratory conditions. Furthermore, we examine whether the “shot hole leaves” symptom is associated with the “excess bud growth” symptom in the fi eld. Our results show that H. theivora can complete their life cycle on Arabica coffee trees. Female bugs lay an average of 87.60±41.82 eggs underneath the soft tissue near young leaves on coffee branches, with a hatching rate of 73.97±6.69%, and an average incubation period of 8.20±0.97 days. The longevity of the fi rst to fi fth nymphal stages was 4.02±1.58, 3.36±0.93, 3.27±0.74, 3.23±0.96, and 3.83±1.18 days, respectively. The adult bugs had a lifespan ranging from 2 to 24 days, with an average of 11.61±7.89 days. The “shot hole leaves” symptom appear approximately 14 days after H. theivora begin feeding on young coffee shoots. We found that the bud number is signifi cantly higher on twigs with the symptom, indicating that both symptoms are caused by H. theivora. The study concludes by discussing control practices of H. theivora on coffee trees.

Homeownership rates, housing policies, and co-residence decisions

Abstract Homeownership rates differ widely across European countries. We document that part of this variation is driven by differences in the fraction of adults co-residing with their parents. Comparing Germany and Italy, we show that in contrast to homeownership rates per household, homeownership rates per individual are very similar during the first part of the life cycle. To understand these patterns, we build an overlapping-generations model where individuals face uninsurable income risk and make consumption-saving and housing tenure decisions. We embed an explicit intergenerational link between children and parents to capture the three-way trade-off between owning, renting, and co-residing. Calibrating the model to Germany we explore the role of income profiles, housing policies, and the taste for independence and show that a combination of these factors goes a long way in explaining the differential life-cycle patterns of living arrangements between the two countries.

Cephalopod ontogeny and life cycle patterns

Life cycle definitions provide the background for conceptualizing meaningful questions to address the mechanisms that generate different life cycle patterns. This review provides explicit definitions and explanations of the steps in a cephalopod life cycle, from fertilization to death. Each large step, or phase, is characterized by a particular developmental process and morphology. Each phase is composed of smaller developmentally distinct steps, or stages. The cephalopod life cycle is comprised of all or some of the following phases: Embryonic, Paralarval, Juvenile, Subadult, Adult and Senescent, and each life cycle is taxon-specific. All cephalopods have direct development and maintain a consistent body plan throughout ontogeny (i.e., no true larval phase and no metamorphosis). Most cephalopods have a life cycle marked by a long early life and a short adult life followed by senescence. Cephalopods have two developmental modes: they produce either small planktonic hatchlings as paralarvae, or large hatchlings as juveniles. All cephalopods go through a Hatchling stage soon after eclosion during which they rely on two modes of nutrition: endogenous (yolk) and exogenous (prey). Many cephalopods with planktonic paralarvae will become benthic early in their life cycle during their Settlement stage or remain pelagic during their Metapelagic stage. Juvenile growth is fast and ontogenetic changes (outside of gonadal maturation) generally cease at the end of the Juvenile phase. The Subadult phase begins when the definitive adult morphology (except for size and body proportions) is acquired (e.g., full complement of photophores). Sexual organs undergo most of their development during the Subadult phase. The Adult phase starts with spawning competency and concludes when gonads are spent. The Senescent phase begins with spent gonads and ends with death. Using this new terminology, we examine the patterns of cephalopod life cycles and find that there are four main patterns based on the presence of a Paralarval phase and the habitat occupied by each phase: Holopelagic (all phases are pelagic), Holobenthic (all phases are benthic), Merobenthic and Meropelagic (phases alternate between benthic and pelagic environments). In these two last patterns, the main difference is the presence of a Paralarval phase in Merobenthic species. The definitions and terminology proposed here provide a unifying framework for future ecological, evolutionary and life cycles research on cephalopods.

Online attention dynamics: The triangle framework of theory, big data and simulations

In computational social science era, the theory, big data and simulations should be well combined and deeply integrated, and this work serves as a typical example. Online collective actions have great impacts to societies, and we focus on the life cycle pattern of coexisting multiple online cases. We propose the analysis framework of “Theory-Big Data-simulation” (TDS). The theory includes two essential action rules of netizens. We combined macro-level analysis (big data analysis) and micro-level behavior (agent-based modeling), to surpport the theory. For the big data, macro-level life cycle pattern (persistent) is caused by micro-level individual actions. For macro-level verification, basic assumption is that netizens are allocating limited attentions to limited coexisting online events, which has been supported by our big data from the Weibo platform (N=197,985). For the micro-level, we use agent-based modeling to verify the behavioral rules of Netizens. We set two agent categories (Netizens & Hots), which behave and interact autonomously. Based on multiple-round simulations, we obtained optimal solution outcomes. Besides, we have implemented mutual validation between big data and agent-based modeling, which has not been considered before. Three big data sets have been applied to check both validity and robustness of our solutions. For the dataset A, we use 89 online cases of the Shaanxi Province in China. For the dataset B, we used 147 online cases of the whole China in 2021. For the dataset C, we used 138 online cases under specific topic (the pandemic). It suggests that three optimal solutions have both validity and robustness. As three big data sets have different levels, cases, topics and durations, the model’s generality can be well supported. Hence, general behavior pattern of the Netizens can be revealed, which is of great significance for investigating human behavior online. Moreover, our work contains rich managerial implications, which helps to improve social simulation and prediction. Also, our TDS analysis framework can support or inspire other researches.

Retirement Saving Over the Life Cycle: Evidence from a Developing Country

ABSTRACT Despite its importance, little is known about how individuals save for retirement through tax-advantaged vehicles over their working lives. Using Thailand’s population of tax returns, this study examines the age profile of retirement saving and explores its implications for retirement savings adequacy. We find that the life-cycle pattern in retirement saving is hump-shaped across age. It rises from 3.0% when one begins working to 4.6% at age 46–48, then declines as one approaches retirement. The retirement saving rates peak later for higher-income workers. For all income groups, we also document the large role of the low-risk saving vehicle throughout the working life. Based on the predicted life-cycle saving profile, we estimate the income replacement rate from tax-advantaged saving vehicles to be around 24%, which is in line with evidence from advanced economies.