Life Stages Research Articles

Will they always be living the Sisyphus punishment? The triple whammy for racialized women: a qualitative investigation of primary care researchers in Canada

Existing literature overlooks the role of gender and race on research productivity, particularly in the context of primary care research. This study examines how gender and race influence the research productivity of primary care researchers in Canada, addressing a gap in existing literature. Qualitative, descriptive methods were used, involving 60-min interviews with 23 Canadian primary care researchers. 13 participants were female (57%) and 10 participants (43%) were male. Fourteen participants were White (non-racialized; 61%), 8 were racialized (35%) and 1 did not comment on race (4%). Reflexive thematic analysis captured participant perceptions of factors influencing research productivity, including individual, professional, institutional, and systemic aspects. Systemic bias and institutional culture, including racism, sexism, and unconscious biases against racialized women, emerge as key barriers to research productivity. The parenting life stage further compounds these biases. Barriers include lack of representation in faculty roles, toxic work environments, research productivity metrics, and exclusion by colleagues. Participants indicated that institutional reforms and systemic interventions are needed to foster a diverse, equitable, and inclusive environment. Strategies include recruiting equity-focused leaders, increasing representation of racialized female faculty, diversity training, mentorship programs, providing meaningful support, flexible work arrangements, and protected research time. Sponsors can offer more targeted grants for female and racialized researchers. Adjusting metrics for gender, race, parenthood, and collaborative metrics is proposed to enhance diversity and inclusion among researchers. This study underscores the importance of addressing systemic bias at institutional and systemic levels to create a fair and supportive environment for primary care researchers. A multitude of strategies are needed including increasing representation of racialized female faculty, creating supportive and psychologically safe work environments, and public reporting of data on faculty composition for accreditation and funding decisions. Together, these strategies can alleviate the triple whammy and free these researchers from the Sisyphus Punishment - the absurdity of being asked to climb a hill while pushing a boulder with no hope of reaching the top. College of Family Physicians of Canada.

From Oh Baby To Child's Pose: Yoga’s Health Implications For Women Across Maternal Life Stages

From Oh Baby To Child's Pose: Yoga’s Health Implications For Women Across Maternal Life Stages

The Effect of Mindfulness and Loneliness on Sense of Purpose in Individuals in the Age of Quarter Life Crisis

Sustainable Development Goals (SDGs) represent a global effort to achieve sustainable prosperity for all, with a strong focus on the quality of the next generation, particularly the youth. The future of a nation is closely tied to the quality of its young population. Early adulthood is a crucial period for determining career paths and life goals, which directly impact personal development and self-quality. One of the critical challenges faced during this period is the quarter life crisis (QLC), characterized by confusion over life purpose. In Indonesia, data shows that more than half of youth experience QLC, typically occurring between the ages of 18 and 35. This study aims to explore the factors influencing a sense of purpose to offer effective strategies for addressing the quarter life crisis. The research was conducted using a quantitative approach with non-probability sampling and survey methods. The sample consisted of 196 respondents (71.7% female and 28.3% male). Data analysis was performed using multiple linear regression with the assistance of SPSS version 8.0 software. Results revealed that mindfulness and loneliness have a significant impact (p<0.05) on the sense of purpose in individuals experiencing QLC, with an R-squared value of 0.090, indicating a 9% influence. These findings highlight the need for targeted counseling and psychological support services to address the quarter life crisis. Providing counseling that focuses on enhancing mindfulness and reducing loneliness can help individuals strengthen their sense of purpose, ultimately enabling them to navigate this challenging life stage more effectively.

Reconciliation in palliative care: A concept analysis.

The aim was to gain a deeper understanding of the meaning of reconciliation as a concept in palliative care. Terminal illnesses affect almost all aspects of life and being close to death may lead to a need for reconciliation. The end of life is stressful on an existential level for both patients and relatives. It can therefore be of relevance for palliative care nurses to understand the meaning of reconciliation. This study used a design for a literature study in accordance with a hybrid model. A deductive qualitative content analysis of autobiographies about being seriously ill and in a palliative stage in life was used to test the meaning of reconciliation. Ethical aspects concerning the use of autobiographies and the ethical principles of the Helsinki Declaration were considered. The theoretical perspective was the caritative theory of caring. The result showed that for patients in palliative care, reconciliation can be described as a strive for acceptance, to live in a truthful way, to forgive and be forgiven. People wish to create meaning in their existence and reconcile as a whole in body, spirit, and soul. By striving to unite suffering, life, and death as well as a peaceful relationship with relatives, people can achieve reconciliation at the end of life. Reconciliation is something ongoing and can be a force in what has been, what is, and what will be. We conclude that reconciliation is a concept of importance when caring for patients in end-of-life care. However, reconciliation can be expressed in different ways without necessarily using the concept itself. A broader and deeper understanding of the concept facilitates conversations about the meaning of reconciliation in palliative care and can enable patients who strive to achieve reconciliation to be more easily identified and supported.

High chytrid prevalence and infection intensities in tadpoles of Mixophyes fleayi

Context The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has caused catastrophic biodiversity loss globally, but species and life stages within species respond differently to the pathogen. Although tadpoles are often reported to be less vulnerable to disease, they can constitute important infection reservoirs in ecosystems. Aims We aimed to describe Bd infection patterns of a long-lived tadpole in a species where post-metamorphic animals appear to exhibit limited mortality as a result of chytridiomycosis. We further investigated how oral dekeratinisation can be used as an indicator of infection. Methods We conducted surveys of tadpoles of Mixophyes fleayi (Fleay’s barred frog) over 2 years, at two rainforest streams on the east coast of Australia, to assess patterns in Bd infection prevalence and intensity. We developed an integrated hierarchical model propagating pathogen-detection errors and incorporating how Bd infections affect oral dekeratinisation. Key results We found that Bd infection prevalence was strongly associated with lower temperatures and a larger body size, consistent with Bd optimal thermal range and a cumulative risk of exposure for tadpoles. The individual probability of a tadpole being infected with Bd was estimated to be 0.58 [95% HPDI: 0.432, 0.713], the odds of which were approximately eight times greater than for adults at the same sites. Tadpoles infected with Bd were 113 [29, 293] times more likely to have oral dekeratinisation than were uninfected tadpoles, where uninfected individuals were estimated to have a 0.05 [95% HPDI: 0.011, 0.11] probability of having mouthpart loss. Conclusions Our results showed that M. fleayi tadpoles are more likely to be infected with Bd than are adults, suggesting that tadpoles could contribute to Bd maintenance in streams. We further showed that sites can be rapidly assessed for Bd by visually checking for oral dekeratinisation. Implications Long-lived tadpoles, in general, may contribute to Bd maintenance in ecosystems. We suggest continued exploration of Bd immunocompetence across amphibian life stages to further understand the vastly different infection patterns.

COGNITIVE FUNCTION OF THE ELDERLY IN PALEMBANG CITY NURSING HOMES: AN EPIDEMIOLOGICAL STUDY

Elderly refers to individuals who have reached the final stage of life, namely 60 years old and above. Physiologically, the elderly will experience various declines in body functions. The decline in cognitive function is among the most common in the elderly. The incidence of cognitive decline in the elderly in Indonesia is relatively high, which is as much as 32.4%, and is most vulnerable at the age of 65 years. Cognitive impairment can cause older adults to have difficulty in doing daily activities (bathing, dressing, washing, cooking), managing finances, getting lost on the road, and other disturbances that make the elderly less independent and confident, then tend to withdraw from social activities. The disturbances can also lead to anxiety disorders and depression. This study aims to determine the profile of cognitive function in the elderly at Palembang Nursing Homes. This cross-sectional study involves all elderly individuals in Palembang City Nursing Homes who meet the inclusion-exclusion criteria. The Indonesian version of the Montreal Cognitive Assessment (MoCA-Ina) was used to assess cognitive function. In this study, as many as 69 elderly (87.34%) had experienced a decline in cognitive function. Then, the dominant characteristics in the group that experienced a decrease in cognitive function were >90 years old (100%), women (91.38%), college graduates (100%), never worked (100%), had a history of stroke (92.86%), did not remember or did not know about cognitive impairment history in the family (93.33%). Delayed recall was the aspect that experienced the most disruption (96.2%). This study has revealed that the prevalence of cognitive impairment in Palembang Nursing Homes is exceptionally high. Therefore, it is imperative to implement routine screenings to identify early cognitive impairment in the elderly to provide immediate treatment.

Dynamics of the event structure of the life course in Russia

The article presents the results of a comparative analysis of the life-event structure of generations of Russians based on empirical data from the Russian Social Survey (RSS) wave 9, comparable with ESS. The analysis showed that the life calendar of currently living generations of Russians is quite strongly structured - events occur in certain and rather narrow time intervals and in a certain sequence. A feature of the life calendar in Russia is a high concentration of all the basic events of the first phase of adult life in a narrow time interval, a short period of entry into adulthood. Events of the late stage of life show greater chronological diversity and scenario variability. Significant differences in the life-event matrix of generations in Russia were found, including an increase in the average age of onset of almost all basic life events, an expansion of the boundaries of age-related life stages, an extension of the path of growing up and the transition from maturity to old age, as well as diversification of life scenarios in the professional and family-marital spheres. When comparing the indices of standardisation of the main events between generations, a trend towards destandardisation of life paths was revealed: in older generations, the level of similarity is significantly higher than among younger generations. The main changes occurred in the generation of 1970-1979 and accelerated in the next generation of 1980-1989. Macro-demographic factors, as well as changes in socio-economic and historical conditions, the transition to a post-industrial society might be named among possible reasons. The trend towards destandardisation of life paths in older generations primarily affected people with a higher level of education, while in younger generations it acquired a broader social and class character; gender differences began to appear in the generation of the 1980s. The authors suggest that the increase in destandardisation of life paths may have multidirectional social and individual consequences. On the one hand, new opportunities for development, building a life path taking into account individual characteristics, talents and desires, greater flexibility of life trajectories, a decrease in normativity and social pressure. On the other hand, this may lead to increased uncertainty, social tension, increased inequalities, and a deepening conflict between “fathers and children,” which will increase social risks in the foreseeable future.

Gender difference in nutritional knowledge, dietary pattern and nutritional status of undergraduates in Ado-Ekiti, Southwest Nigeria

BackgroundPoor nutritional knowledge at an early stage of life suggests developing poor dietary habits that later lead to obesity and attendant complications of non-communicable diseases.ObjectiveThis study examined gender differences in nutritional knowledge, dietary pattern and the prevalence of overweight/obesity among students of a private tertiary institution in Ado-Ekiti, Ekiti State, Nigeria.MethodsA total of 214 students were recruited to this study from the six colleges of the university. A semi-structured questionnaire was used to collect information on personal and lifestyle characteristics, dietary patterns and physical activity. Weight and height measures were used to calculate Body Mass Index (BMI). Data were analyzed using descriptive statistics and chi square test at 5% level of significance.ResultsThe mean age of the students was 19±1.89years. Monthly allowance of ≥₦50, 000.00 ($70) was received by 64%; 80% and 78% of them had fathers and mothers respectively with university degrees. Physical exercise was not done by 40%, 69% took < 3meals/day and 60% skipped breakfast; 71% and 21% had medium and high dietary diversity scores respectively. The mean BMI was 24.6±3.70; 36% had a BMI ≥25. Regarding their nutritional knowledge, 16% were high. There were no gender differences in BMI, nutritional knowledge or dietary diversity.ConclusionsThe study revealed less than ideal nutritional knowledge and dietary diversity and prevalence of overweight/obesity. Great emphasis needs to be given to nutrition education and promotion among university students.

Circular plastic consumption in everyday life: a nexus of practice perspective

Plastic consumption is posing a critical challenge to global sustainability. Yet our understanding of the social and everyday dynamics of how and why people use plastics remains limited. Particularly, significant gaps in understanding exist concerning how plastics are embedded in households’ daily routines and practices and how this varies across different daily life settings. This article aims to bridge this gap by offering an in-depth exploration of the social and material dimensions of plastic consumption in varied Dutch households. Employing a theoretically and methodologically innovative approach, the article advances understanding of the connectivity of daily practices influencing household plastic use. Combining a social practice theoretical framework with a future-oriented, multi-modal imaginary methodology, we explore practice dynamics across diverse households of distinct life stages and compositions. Our analysis uncovers the complex interplay between daily practice arrangements and their systemic integration, revealing how daily life’s material, spatial and temporal dimensions are shaped and enabled by plastics. The study highlights the nuanced ways in which social variations in the organisation and institutional structures of daily life and engagement with socio-technical systems lock people into plastic consumption or enable transformative possibilities for sustainable change. By shedding light on the often overlooked social and everyday dynamics of plastic consumption, the article deepens theoretical understanding of practice connectivity while also opening new avenues for envisioning and facilitating transformation towards circular plastic consumption.

Ocean conditions influence the quality of recruiting benthic marine invertebrate larvae—Insights from fatty acids

AbstractMany marine benthic invertebrates have a pelagic life stage, during which larvae need to accumulate enough reserves to complete metamorphosis to a settled benthic juvenile. Currently, very little is known about how ocean conditions affect quality of the larvae. We studied this for three settlement seasons (2017–2019) by collecting returning Dungeness crab (Metacarcinus magister) megalopae at the Oregon coast and analyzing them for fatty acid biomarkers. We found that the larvae are omnivorous and have versatile diets. The daily larval abundance was positively correlated with larval quality. Despite the relatively high day‐to‐day variation, we found pronounced seasonal and inter‐annual differences in the body condition (size and total fatty acid content) and biomarker composition of megalopae. Especially, the early season recruits of 2017 had lower content of lipids and polyunsaturated fatty acids known to be beneficial to crustaceans. This is likely related to lingering effects of the eastern Pacific marine heat wave (2014–2016) on pelagic communities. The larvae were rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) with lower levels in benthic juveniles, indicating an ontogenetic diet shift and likely lower availability of DHA and EPA in the benthic environment. The pulsed megalopa recruitment may provide substantial carbon and lipid inputs to the nearshore ecosystem as a form of pelagic subsidy. Our results reveal that ocean conditions may have an effect on the quality of returning larvae, which likely influence their recruitment performance and early juvenile success, and thus potentially also the population size and commercial catch 4 yr later.

Fitness and Survival of the Fall Armyworm, Spodoptera Frugiperda (Lepidoptera: Noctuidae) on Maize in West Java, Indonesia

An important pest of maize is a new invasive species called Spodoptera frugiperda, also known as the fall armyworm (FAW), causing a considerable economic impact in Indonesia since 2019. This insect has a large host range, a quick generation time at the right temperature, a high rate of reproduction, and a high dispersal capacity. In population ecology and pest management, fitness and survival are crucial. This research was aimed to determine some biological aspects and demographic statistics of three FAW populations (lowland, midland, and highland) in a laboratory setting with 25 ± 2 °C, 75 ± 5% relative humidity, and a 12:12 (L:D) hour photoperiod. Findings indicated no variation in the length of the FAW life stage or its reproductive capacity. Nonetheless, notable variations were noted in the average fecundity of females, with FAW of the highland population laying the most eggs (1242.1 eggs). FAW had the shortest mean generation time (T), the highest intrinsic rate of increase (rm), the finite rate of increase (λ), and the highest net reproductive rate (R0) of the highland population. Overall FAW collected from highland, midland, and lowland can adapt well when brought to a laboratory with a constant temperature at 25 ± 2 °C without detriment to the parameters of the life table. The knowledge gained from this study is crucial for managing FAW because it improves comprehension of its life cycle and adaptability to various altitudes, enabling us to take appropriate action to stop its spread.

Happy childhood: the search for an informative system of characteristics through the prism of eventfulness

The results of a study devoted to identifying the potential of using information about childhood events to explain the subsequent perception of childhood as a happy one are presented. Based on the assumption that the specificity of the eventfulness of the very first stage of life can determine the existence of groups with happy and unhappy childhood according to subjective estimates, a selection of childhood events has been made that most allow differentiating those who evaluate their childhood as happy and unhappy. As an empirical basis, the results of a survey of representatives of a youth group who have crossed the age of majority or are on its border are used. Among the 100 initial childhood events for analysis, groups of life episodes were identified, the presence and age of occurrence of which are associated with a retrospective assessment of childhood as happy. These are events related to the manifestation of subjectivity and its recognition by adults; consumer and financial socialization ; establishing relationships with peers and parents; independent movements and mobility; a variety of leisure practices and prosocial behavior; some manifestations of infantilism; the absence or later onset of certain traumatic events, deviant behavior practices, actions to change appearance. The listed groups of life episodes form the basis of an informative system of characteristics of a subjectively prosperous childhood and can be used in the future to implement models of multidimensional analysis.

Variation in the Local Grey Mullet Populations (Mugil cephalus) on the Western Pacific Fringe

Background: Understanding population genetic structures is crucial for planning and implementing conservation programmes to preserve species’ adaptive and evolutionary potential and thus ensure their long-term persistence. The grey mullet (Mugil cephalus) is a globally distributed coastal fish. Its populations in waters surrounding Taiwan on the western Pacific fringe are divided into at least two stocks (migratory and residential), but questions remain regarding their genetic divergence and gene flow. Methods and Results: To cast more light on this, allozyme variations at 21 presumptive gene loci of 1217 adult grey mullets from 15 localities in Japan, Taiwan and mainland China, and four gene loci from 1470 juveniles from three localities in Taiwan were used to investigate patterns of genetic variation. The mean expected heterozygosity (He) was 0.128—ranging from 0.031 (Matsu) to 0.442 (Kaoping)—and the mean observed heterozygosity (Ho) was 0.086—ranging from 0.017 (Kaohsiung) to 0.215 (Kaoping). Both AMOVA and the high overall mean FST of 0.252 indicated enormous genetic differentiation among populations and the positive mean value of FIS was 0.328, indicating a deficiency of heterozygotes. PCoA indicated that the samples of M. cephalus could be split into three groups and STRUCTURE analysis showed that all individuals were grouped into three genetic clusters. The results of mutation-drift equilibrium tests did not suggest that the populations experienced any recent genetic bottleneck. The results from all localities in the present investigation showed significant change in the GPI-A genotype frequencies with latitudes—e.g., increases in GPI-A*135/135 homozygote frequencies and GPI-A*100/100 frequencies were highly correlated with latitudinal cline. All migratory populations with the GPI-A genotype were almost exclusively the GPI-A*100/100 homozygote. During the life history of M. cephalus, the GPI-A*100/135 heterozygote frequency significantly decreases with age. Conclusions: Based on these data, we suggest that each GPI-A genotype represents trait combinations of higher fitness in some portions of the environment. Furthermore, the genotypic frequencies change in accordance with life stages, suggesting that selection occurs throughout the life span.

Recommendation of consensus definition of sea turtle fibropapillomatosis

AbstractSea turtle fibropapillomatosis (FP) is an emerging transboundary contagious disease that affected concomitantly two different marine hot spots in the Northern Atlantic Ocean and in the South China Sea at the beginning of the twentieth century. FP reached a panzootic status in the 1990s in green turtle (Chelonia mydas) populations, with increased risks of emergence and spread of the disease which have been correlated with climate induced terrestrial and oceanic physical and chemical changes. During 2023–2024, scientific experts performed a bibliographic review and recommend the consensus definition of sea turtle fibropapillomatosis. FP is an emerging transboundary viral terrestrial and aquatic contagious neoplastic syndrome involving cancerous molecular transmission pathways, which may affect all species of sea turtles at all life stages. The diagnosis of the most common verrucous form of FP is pathognomonic by visual examination of a sea turtle. We summarize the main clinical characteristics of FP, moderated by a degree of confidence of research findings adapted from the Intergovernmental Panel on Climate Change (IPCC) assessment reports. We recommend the implementation of a universal and transparent monitoring strategy of sea turtle fibropapillomatosis in sentinel bays, under the governance of the World Organisation for Animal Health.

The Impact of Chronic Exercise on Cognitive Function: An Overview of Reviews

Objective: Understanding the associations between cognitive function and chronic exercise has gained significant attention in the last decade. This overview aims to consolidate current knowledge and shed light on potential benefits of long-term exercise on cognitive abilities. Method: Relevant databases, including Scopus, PubMed, and Web of Science, were searched through predefined keywords related to chronic exercise and cognitive function. We included all relevant systematic-reviews and meta-analysis in our data-synthesizing. Results: We identified 74 references across PubMed (33), Scopus (35), and Web of Sciences (6). After deduplication, 52 unique references remained. Screening by title and abstract yielded 28 relevant studies. Full-text review based on inclusion criteria resulted in nine eligible articles. Most were meta-analyses, examining 10 to 71 randomized controlled trials on executive functions across various age groups and health statuses. Both acute and chronic exercises demonstrated small to moderate positive effects on cognitive functions, with chronic exercise outcomes influenced by type, duration, frequency, session length, age, and cognitive status. Conclusion: Extensive research underscores a robust and compelling link between involving in regular, long-term physical exercise and enhancement of cognitive functioning. This connection emphasizes the critical role that consistent physical activity plays in safeguarding mental well-being and maintaining sharp cognitive abilities throughout various life stages. Positive effect of sustained physical exercise on cognitive functioning serves as a compelling reason to integrate exercise as a fundamental component of a holistic approach to mental wellness and cognitive longevity.

An Examination of EOL Trajectories and Audit of EOL Documentation In Patients Admitted Under the Department for Older Persons Services

Abstract Background End of Life Care is a core element of care provided in acute hospitals, with 44% of Irish deaths taking place in the hospital setting. Our audit looks at the quality of documentation around end of life for older patients and looks to characterize these hospitalized patients’ terminal life stages. Methods Inclusion criteria were patients over the age of 65 who died under the care of the Department for Older Persons Services in 2023 utilizing a retrospective chart review. The Oxford Audit Assessment Tool for Care of the Dying was used to evaluate end of life documentation for patients recognized as dying in the acute hospital setting using a 1–5-point scale. The hospital courses of patients who died were characterized along one of six in-hospital courses: (1) acutely unwell, (2) end stage organ failure, (3) dwindling trajectory, (4) unexpected cardiac arrest, (5) admission with known specialist palliative care needs, and (6) combination of medical complexity and high dependency. Data points included Clinical Frailty Score and NecPal Score, as well as length of hospital stay, length of dying and specialist palliative care input. Results Greater than 90% of patients under the Department for Older Persons service had satisfactory, good or excellent documentation around end-of-life care. One-third of patients who died under the service were acutely unwell, one-fifth of the patients who died in hospital followed a dwindling trajectory, and 15% of patients were admitted with known indication and need for specialist palliative care. Approximately 10% of patients who died suffered an unexpected cardiac arrest. Conclusion Overall, documentation at end of life was quite good and specialist palliative care services were frequently involved. Older patients frequently experience a complex interplay of high dependency, medical complexity and palliative care needs at end of life, highlighting the need for skilled serious illness communication.

Classification of Vase Life Day Based on Petal Colorimetric Data in Cut Lisianthus Using AutoML

This study investigated the potential of petal colorimetric data to classify vase life stages in cut lisianthus flowers (Eustoma grandiflorum). We analyzed the changes in the petal color space over time, focusing on the b* value as an indicator of senescence due to increasing yellowing caused by copigmentation. A comparative analysis was conducted between two cultivation methods: soil (S) and hydroponic (H) cultivation. The objective was to evaluate the performance of machine learning models trained to classify vase life stages based on petal color data. Automated machine learning models exhibited better performance in H-cultivated cut flowers, effectively distinguishing days within the vase life stages from Days 1 to 14 for H cultivation. Cut flowers cultivated under S conditions showed less variation in the color space from Days 1 to 9, maintaining a relatively uniform color range. This made it more difficult to distinguish the vase life stages compared to H cultivation. These findings demonstrate that petal color metrics can serve as reliable indicators of cut flower senescence and potentially facilitate nondestructive methods for classifying vase life stages. This technology holds promise for wider applications in the floriculture industry, improving quality control, and extending the vase life of various cut-flower crops.

Navigating neighborhoods: Density, size, and species diversity influences on tree survival in subtropical secondary forests

Neighborhood effects significantly impact individual tree survival through mechanisms of resource competition and species interactions within forest ecosystems. However, the specific impacts of these effects, particularly how biodiversity feedback affects survival across diverse life stages and spatial scales in subtropical secondary forests, remains insufficiently documented. To bridge this gap, we conducted an extensive analysis of neighborhood effects at different life stages and spatial scales in the subtropical secondary forests of the Wuyi Mountains in Southeast China, uncovering key insights into the community structure and dynamics. Our investigation over a five-year period encompassed all individuals within our study plot, quantifying effects of neighborhood density, individual size in resource competition, and species diversity in the neighborhood across various life stages. Employing mixed-effects models, we established quantitative relationships to assess the impact of these factors on tree survival at different spatial scales. Our findings confirmed that density dependence adversely affects sapling survival at smaller scales. As trees mature and spatial test scales expand, the detrimental effects of conspecific resource competition on individual mortality decrease, whereas heterospecific resource competition notably impairs survival probabilities in later successional stages, suggesting a shift from intraspecific to interspecific competition as the dominant influence on mortality during secondary succession. Additionally, we detected consistent patterns in conspecific and heterospecific density effects with increasing spatial scale. These effects transitioned from interspecific differences at smaller scales to more uniform positive effects at larger scales, which may be attributed to the strong spatial dependency of neighborhood density effects, potentially due to increased habitat heterogeneity. Furthermore, our study highlights the crucial role of heterospecific neighborhood effects in enhancing survival. We observed significant positive impacts of species diversity and heterospecific interactions on individual tree survival, particularly at smaller spatial scales during the sapling stage. Importantly, our research unveils significant variability in species sensitivity to different neighborhood effects, which change with life stage and spatial scale. This underscores the necessity of accounting for life stage variations among species and the influence of spatial heterogeneity on neighborhood effects such as density. Our findings delineate distinct competition mechanisms between the earlier and later phases of forest succession, emphasizing the distinctive recovery processes of subtropical secondary forests. These insights are essential for informing forest management and conservation strategies, ensuring a nuanced understanding of forest community dynamics.

Vulnerable periods for the mouse mammary gland: comparison of the effects of ethinyl estradiol exposures during two early stages of development

The mammary gland is responsive to endogenous hormones and environmental chemicals that are estrogen receptor (ER) agonists. The mouse mammary gland offers the opportunity to dissect the most sensitive windows of exposure. 17α-ethinyl estradiol (EE2) is a pharmaceutical ER agonist that often serves as a positive control for estrogen-active chemicals. Here, adult female mice were exposed to EE2 starting either at pregnancy day 7, or on lactational day 1, and exposures continued until the litters were weaned. The pups were therefore exposed during gestation + the juvenile period, or during the juvenile period alone. The morphology of the mammary gland was evaluated in both male and female offspring at two life stages: weaning (postnatal day [PND]21) and at puberty (PND32). Other hormone-sensitive outcomes evaluated included body weight, anogenital index, frequency of open vagina, and weight of the uterus. We found age- and sex-dependent effects of EE2 on these estrogen-responsive endpoints including the morphology of the mammary gland. Importantly, EE2 altered mammary gland morphology even when exposures were limited to the juvenile period. However, the number of endpoints that were affected in animals from the EE2-Juvenile-Only period were fewer, and typically of a lower magnitude, compared to those observed in the EE2-Gest-Juvenile group. Understanding the effects of environmental estrogen exposures during the juvenile period is critical because humans are exposed to estrogenic pollutants throughout life, including in early childhood.

Fecundity without nectar is insufficient for the persistence of a blue butterfly.

Organisms with complex life cycles undergo ecological transitions between life stages, often resulting in stage-specific resource use. The relative contribution of each stage-specific resource to vital rates influences population dynamics and subsequently whether habitats can support viable populations. In lepidopterans, survival to reproduction requires sufficient resources for immature life stages, but the extent to which resources for adults are critical to population persistence is variable. We studied Boisduval's blue butterflies (Icaricia icarioides), in a greenhouse experiment, to quantify the effect of the adult diet, nectar, on vital rates. Butterflies fed ad libitum produced 3.4 times more eggs, on average, over their lifetime and lived 6 more days relative to those which only had access to water. We used these experimental data to parameterize a population model to test if vital rates with and without nectar result in viable population growth rates. Despite individual females laying 68 eggs without nectar, we found that Boisduval's blue butterfly populations will not persist without the improved fecundity associated with nectar resources (λ<1). In this species, although amino acids in the adult diet contributed to various improvements in fecundity, these improvements did not translate to improvements in population growth rates. Incorporating our experimental vital rates into a population model indicates that the relative abundance and quality of nectar can alter at what threshold other resource(s) are limiting the population.