Critical Period Research Articles

Shyness and self-consistency and congruence among Chinese adolescents: mediating role of social comparison orientation and moderating role of self-focused attention

During the critical period of personality shaping and self-development, adolescents face unique challenges and opportunities. This study, based on Cognitive-Behavioral Theory, explored the relationship between shyness and self-consistency and congruence (hereinafter referred to as SCC), as well as its underlying mechanisms. Through a questionnaire survey on shyness, social comparison orientation, self-focused attention, and SCC among 984 adolescents, the results revealed that (1) Adolescent shyness negatively predicted SCC. (2) Social comparison orientation partially mediated the relationship between shyness and SCC. (3) Self-focused attention moderated the direct pathway of this mediation process, where a high level of self-focused attention exacerbated the negative impact of shyness on SCC. These findings offered a new perspective on understanding SCC and underscored the importance of addressing the information processing mechanisms of social comparison orientation and self-focused attention among shy adolescents in interventions aimed at promoting their psychological harmony and healthy growth.

Creation and validation of the online self-disclosure via educational platforms scale

Globally, higher education (HE) institutions now implement some element of hybrid learning, heightened since the COVID-19 pandemic and temporary shift to online learning. To communicate, online self-disclosure (revealing information about the self) is required. The majority of HE students are aged between 18-24 years, which is considered the developmentally sensitive period of ‘emerging adulthood’. Having only ever known a digitally-connected world, emerging adults self-disclose differently to other generations when communicating via an online environment. Whilst communicating online with HE staff, students may self-disclose in a way that misaligns with the expectations of staff; this may result in miscommunication or over-disclosure (revealing inappropriate information to a misjudged audience). Over-disclosing via online educational platforms (e.g., Moodle, MS Teams, and e-mail) may result in negative feedback from staff and this may impact student experience, engagement and attainment. Problematically, no standardized measure exists that captures student self-disclosure via online educational platforms and so research on this topic is currently limited and theoretically unstable. Via a three-phase study, comprising four studies and 283 participants, we have created and conducted an initial evaluation of the online self-disclosure via educational platforms (OSDEP) scale. The OSDEP scale is the first psychometric tool to specifically measure HE students’ online self-disclosure behaviors specifically within an online educational context. The OSDEP scale can be used for future educational and pedagogical research to further understand HE students’ online self-disclosure behaviors and to what extent these may be associated with topics such as mental health, engagement, attainment, and student experience.

Discrimination experiences and problematic alcohol and cannabis use in young adulthood.

Limited research has examined how discrimination in young adulthood relates to substance use. We examined how multiple and specific types (e.g., race-based) of experiences of unfair treatment are related to problematic alcohol and cannabis use. We analyzed cross-sectional data from a diverse cohort of young adults (mean age 24.7) predominantly residing in southern California (n = 2303) to examine associations of multiple (count) and specific experiences (race-, sexual orientation-, gender-based) of perceived everyday discrimination with self-reported alcohol and cannabis use outcomes (consequences, use disorders, and solitary use). We also tested interactions between the three specific discrimination experiences and sociodemographic characteristics (e.g., race-based discrimination × race/ethnicity). In this diverse sample (e.g., 47% Latinx/o and 22% Asian; 22% sexual/gender diverse; 56% female) of young adults, about 46% reported up to four different discrimination experiences and 27% reported race-, 26% gender-, and 5% sexual orientation-based discrimination. Race- and gender-based discrimination and experiencing more types of discrimination were associated with worse cannabis use outcomes. Race-based discrimination was associated with fewer alcohol consequences and lower Alcohol Use Disorders Identification Test (AUDIT) scores. Associations with sexual orientation-based discrimination and the interactions were not significant. Findings build on limited research on associations of discrimination with cannabis use in young adults. More work is needed to understand the mechanisms by which discrimination influences drinking behaviors. This study advances the field by examining the unique contributions of specific and multiple types of discrimination experiences in young adulthood, a critical developmental period in which substance use peaks.

Temperature-Dependent Sex Determination in Crocodilians and Climate Challenges

The sex of crocodilians is determined by the temperature to which the eggs, and hence the developing embryo are exposed during critical periods of development. Temperature-dependent sex determination is a process that occurs in all crocodilians and numerous other reptile taxa. The study of artificial incubation temperatures in different species of crocodiles and alligators has determined the specific temperature ranges that result in altered sex ratios. It has also revealed the precise temperature thresholds at which an equal number of males and females are generated, as well as the specific developmental period during which the sex of the hatchlings may be shifted. This review will examine the molecular basis of the sex-determination mechanism in crocodilians elucidated during recent decades. It will focus on the many patterns and theories associated with this process. Additionally, we will examine the consequences that arise after hatching due to changes in incubation temperatures, as well as the potential benefits and dangers of a changing climate for crocodilians who display sex determination based on temperature.

Development of ocular dominance columns across rodents and other species: revisiting the concept of critical period plasticity

Development of ocular dominance columns across rodents and other species: revisiting the concept of critical period plasticity

Spatial heterogeneity of soil moisture caused by drainage and its effects on cadmium variation in rice grain within individual fields

Paddy drainage is the critical period for rice grain to accumulate cadmium (Cd), however, its roles on spatial heterogeneity of grain Cd within individual fields are still unknown. Herein, field plot experiments were conducted to study the spatial variations of rice Cd under continuous and intermittent (drainage at the tillering or grain-filling or both stages) flooding conditions. The spatial heterogeneity of soil moisture and key factors involved in Cd mobilization during drainages were further investigated to explain grain Cd variation. Rice grain Cd levels under continuous flooding ranged from 0.16 to 0.22 mg kg−1 among nine sampling sites within an individual field. Tillering drainage slightly increased grain Cd levels (0.19–0.31 mg kg−1) with little change in spatial variation. However, grain-filling drainage greatly increased grain Cd range to 0.33–0.95 mg kg−1, with a huge spatial variation observed among replicated sites. During two drainage periods, soil moisture decreased variously in different monitoring sites; greater variation (mean values ranged from 0.14 to 0.27 m3 m−3) was observed during grain-filling drainage. Accordingly, 2.9–3.3-fold variation in soil Eh and 0.55–0.67-unit variation in soil pH were observed among those sites. In the soil with low moisture, ferrous fractions such as ferrous sulfide (FeS) were prone to be oxidized to ferric fractions; meanwhile, the followed generation of hydroxyl radicals involved in Cd remobilization was enhanced. Consequently, soil dissolved Cd changed from 2.97 to 8.92 μg L−1 among different sampling sites during grain-filling drainage; thus, large variation was observed in grain Cd levels. The findings suggest that grain-filling drainage is the main process controlling spatial variation of grain Cd, which should be paid more attention in paddy Cd evaluation.

Persistent vocal learning in an aging open-ended learner reflected in neural FoxP2 expression

BackgroundMost vocal learning species exhibit an early critical period during which their vocal control neural circuitry facilitates the acquisition of new vocalizations. Some taxa, most notably humans and parrots, retain some degree of neurobehavioral plasticity throughout adulthood, but both the extent of this plasticity and the neurogenetic mechanisms underlying it remain unclear. Differential expression of the transcription factor FoxP2 in both songbird and parrot vocal control nuclei has been identified previously as a key pattern facilitating vocal learning. We hypothesize that the resilience of vocal learning to cognitive decline in open-ended learners will be reflected in an absence of age-related changes in neural FoxP2 expression. We tested this hypothesis in the budgerigar (Melopsittacus undulatus), a small gregarious parrot in which adults converge on shared call types in response to shifts in group membership. We formed novel flocks of 4 previously unfamiliar males belonging to the same age class, either “young adult” (6 mo − 1 year) or “older adult” (≥ 3 year), and then collected audio-recordings over a 20-day learning period to assess vocal learning ability. Following behavioral recording, immunohistochemistry was performed on collected neural tissue to measure FoxP2 protein expression in a parrot vocal learning center, the magnocellular nucleus of the medial striatum (MMSt), and its adjacent striatum.ResultsAlthough older adults show lower vocal diversity (i.e. repertoire size) and higher absolute levels of FoxP2 in the MMSt than young adults, we find similarly persistent downregulation of FoxP2 and equivalent vocal plasticity and vocal convergence in the two age cohorts. No relationship between individual variation in vocal learning measures and FoxP2 expression was detected.ConclusionsWe find neural evidence to support persistent vocal learning in the budgerigar, suggesting resilience to aging in the open-ended learning program of this species. The lack of a significant relationship between FoxP2 expression and individual variability in vocal learning performance suggests that other neurogenetic mechanisms could also regulate this complex behavior.

Women's mental health during late pregnancy: A survey conducted in Shandong Province, China.

The study aimed to investigate the general mental health status and its associated factors in women during late pregnancy. The objective was to provide a scientific basis for developing psychological interventions tailored to this specific population. The research was conducted from May 2021 to July 2022, involving the recruitment of 200 women attending maternal and child health clinics for their late-pregnancy checkups. Data collection was carried out using a comprehensive approach, involving several validated tools. The participants completed a general demographic and sociological questionnaire along with four standardized psychological assessment scales: the 12-item General Health Questionnaire (GHQ-12), the Athens Insomnia Scale (AIS-8), the Generalized Anxiety Disorder 7 (GAD-7), and the 9-question Patient Health Questionnaire (PHQ-9). A total of 200 valid questionnaires were collected for analysis. The study revealed that the overall prevalence of positive detection of general mental health problems in women during late pregnancy was 11%. Significant differences were observed in the positive detection rate of general mental health status based on various factors such as the quality of relationships with husbands, pregnancy intentions, insomnia, anxiety, and depression (p<0.01). Furthermore, participants with general mental health problems displayed notably higher scores on the AIS-8, PHQ-9, and GAD-7 scales compared to those without such problems (p<0.01). Regression analysis indicated that pregnancy intention and PHQ-9 scores were influential factors affecting the general mental health of women during late pregnancy (p<0.05). The study highlights high rates of general mental health problems during late pregnancy, with unplanned pregnancy and elevated depression scores as key risk factors. Regular mental health screening and targeted interventions are essential to support women during this critical period and enhance the well-being of both mothers and babies.

Antihypertensive utilization patterns among pregnant persons with pre-existing hypertension in the US: A population-based study.

Hypertension among persons with childbearing potential is on the rise. Maintaining proper blood pressure during pregnancy is vital to prevent maternal and neonatal complications. Yet, limited evidence on the risk-benefit of various antihypertensives presents challenges for informed decision-making during this critical period. This study aimed to examine the utilization patterns of different classes of antihypertensives among persons with pre-existing hypertension before, during, and after pregnancy. We used MarketScan® Commercial Database 2011-2020 to analyze antihypertensive utilization among pregnant persons aged 12 to 55 identified via a validated algorithm. Pre-existing hypertension was defined as ≥1 inpatient or ≥2 outpatient encounters for hypertension within the 180 days preceding the LMP. Antihypertensive utilization was described during target periods: 0-3 months (0-3M) before pregnancy, 1st/2nd/3rd trimester (T1/2/3), 0-3M, and 4-6M after pregnancy. We identified 1,950,292 pregnancies, of which 20,576 (12,978 live and 7,598 non-live) had pre-existing hypertension. Both groups had similar antihypertensive use (80.1% and 81.0%, respectively) during the 6 months before pregnancy (baseline). For live-birth pregnancies, 13.9% of baseline users discontinued treatment during pregnancy, while 28.9% of non-users initiated antihypertensives during pregnancy, and 17.2% started postpartum. Before pregnancy, the predominant antihypertensives included thiazide diuretics (21.9%), combined α- and β-blockers (18.4%), and dihydropyridines (16.2%). During pregnancy, thiazide diuretics, cardioselective β-blockers, and ACE inhibitors declined (T3: 3.0%, 4.2%, and 0.8%). Dihydropyridine use was steady during pregnancy, but preference shifted from amlodipine to nifedipine in T3 (2.2.% vs.10.8%). Central α2-agonists increased during pregnancy (up to 15.2% in T3) compared to both pre- (9.8%) and post-pregnancy (5.7%). ARBs mirrored ACE inhibitors, with less than 1% utilization in later trimesters. Combination agents dropped from 10.8% pre-pregnancy to 0.8% in T3, then rebounded to 7.3% post-pregnancy. Research is warranted to evaluate the choice of antihypertensives and optimal timing to switch to safer alternatives, considering maternal and fetal outcomes.

Chronic Adolescent Restraint Stress Downregulates miRNA-200a Expression in Male and Female C57BL/6J and BALB/cJ Mice

Adolescence is a critical developmental period when the brain is plastic, and stress exposure can have lasting physiological consequences. One mechanism through which adolescent stress may have lasting effects is by altering microRNAs (miRNAs), leading to wide-scale gene expression changes. Three prior independent studies used unbiased approaches (RNA sequencing or microarray) to identify miRNAs differentially expressed by chronic variable stress in male rodents. In all three studies, miRNA-200a was differentially expressed in areas of the brain associated with emotion regulation. The current study extends this research to determine if chronic non-variable adolescent stress downregulates miRNA-200a expression by looking at two strains (BALB/cJ and C57BL/6J) of male and female mice. We utilized a 14-day (2 h/day) restraint stress protocol and verified stress effects on adolescent body weight gain and circulating corticosterone concentrations relative to non-restraint controls. Mice were then left undisturbed until they were euthanized in adulthood, at which time brains were collected to measure miRNA-200a in the ventral hippocampus. Three weeks after adolescent stress ended, differences in body weight between groups were no longer significant; however, animals exposed to stress had less miRNA-200a expression in the ventral hippocampus than control animals. These data implicate miRNA-200a expression as a potential mechanism by which adolescent stress can have persistent impacts on multiple outcomes in both male and female mice.

P-368 In vitro culture with rutin and VEGF-A before xenotransplantation protects ovarian tissue from ischemia and oxidative damage but not from growing follicle depletion

Abstract Study question Can pre-treatment with antioxidant and vascular endothelial factor (VEGF-A) help to maintain healthy tissue structure and follicle pool in xenotransplanted human ovarian tissue? Summary answer Rutin and VEGF-A help to prevent fibrosis and oxidative stress damage in grafted ovarian tissue but cannot preserve growing follicles. What is known already Nowadays, ovarian tissue (OT) cryopreservation and autotransplantation become established fertility preservation methods in numerous countries. However, even if hundreds of children has been born thanks to this procedure, most crucial process during which 70-80% of the follicles are lost in the graft is the transplantation itself. As the graft restores vascularisation and regains its function the tissue undergoes ischemia and oxidative stress. There have been attempts made to improve this critical postoperative period by administration of different growth factors, hormones, antoxidants or mechanical tissue damage. Study design, size, duration Pieces of frozen-tharwed OT (2,5 × 2,5 mm) from 10 women were transplanted into immunodeficient mice for 4 weeks. Before xenotransplantation OT fragments were in vitro cultured for 36h in culture media supplemented with 1 μg/ml rutin and 50 ng/ml VEGF-A (n = 10 OT, pretreated grafted) or without (n = 10 OT, non-pretreated grafted). Frozen-thawed OTs were used as non-grafted controls for ischemia-reperfusion injury, apoptosis and follicle loss evaluation. Participants/materials, setting, methods OTs were received from cancer patients (n = 10) undergoing cryopreservation at National Cancer Institute. Xenotransplantation was performed at Life Sciences Centre, Vilnius University. Retrieved grafts were devided into one small piece for immunochistochemical evaluation of α-SMA and apoptosis by TUNEL, and one bigger piece for qPCR analysis of genes related to tissue integrity (PRDX1, SOD1, FN1, COL6A1, CASP3, ANGPT2, mouse CD31) and follicle development (FOXO3, FSHR, GDF9), house keeping gene being GAPDH/Gapdh. Main results and the role of chance After 4 weeks of grafting, multiple genes and protein expressions were evaluated. Vascularisation evaluation: compared to non-grafted group, in grafted OTs we observed significantly more vessels (α-SMA staining, p &amp;lt; 0.0001 and ANGPT2 expression, p &amp;lt; 0.05), as well 1,5-fold higher relative expression of mouse CD31 in pretreated grafted group vs non-pretreated grafted group. Qxidative stress and apoptosis evaluation: expression of SOD2, PRDX1 and CASP3 genes was lower in both grafted groups compared to non-grafted control, significant alterations between xenotransplanted groups were found. Structural gene evaluation: in non-grafted control we could find higher expression of COL6A1 and FN1 genes compared to grafted groups and statistical difference of COL6A1 expression in between grafted groups (p &amp;lt; 0.05). Follicle pool evaluation: primordial follicle activation was measured by FOXO3 gene expression change, though we did not find significant differences between any of three groups, p = 0.06 was observed between grafted OT groups. Maturing follicles were evaluated by expression changes in GDF9 and FSHR genes. We observed significant decrese in expression of these genes in grafted groups (p &amp;lt; 0.05). Results from TUNEL are awaited, thus are the quantification of apoptotic cells, which will provide valuable insights for correlation with vascularisation and oxidative stress. Limitations, reasons for caution This study was performed only in a long-term xenotransplantation setting, we cannot know if rutin and VEGF-A had a significant influence during the first days of OT transplantation. Due to the small size of OT grafted, counting and distribution of follicles was not performed, Wider implications of the findings This study shows that pretreatment of OTs with rutin and VEGF-A could be potentially used in human setting due to protection of ischemia and oxidative stress, especially if the survival of growing follicles is not required, as it is in cases of prepubertal girls. Trial registration number not applicable

P-617 The investigation of the shared genetic architecture between hypothyroidism and age at menopause

Abstract Study question Is there a shared genetic architecture and a putative causal association between hypothyroidism and age at menopause (AM)? Summary answer There is a genetic correlation and a causal relationship between Hypothyroidism and AM. What is known already Thyroid disease is more common in women. The interplay between thyroid function and the gonadal axes remains interconnected throughout a woman’s reproductive cycle. Notably, the menopausal phase represents a critical period for metabolic alterations, wherein thyroid hormones and metabolic status are intricately intertwined. Study design, size, duration Data from publicly available genome-wide association study (GWAS) summary statistics of hypothyroidism (European-based: 51,194 hypothyroidism cases and 443,383 controls) and AM (European-based: N = 141,926) were used to investigate shared genetic assosiation. Participants/materials, setting, methods Shared genetics between hypothyroidism and AM were explored using linkage disequilibrium score regression, ρ-HESS, cross-trait meta-analysis, colocalization analysis and summary data-based Mendelian randomization, and investigated causal associations using Mendelian randomization. Main results and the role of chance The estimated liability scale of the single nucleotide polymorphisms (SNPs) heritability for AM and hypothyroidism was 13.0% and 5.1%, respectively. A substantial negative genetic association (rg = -0.081, P = 0.0055) was found by bivariate LDSC between hypothyroidism and AM. Local Genetic Correlations identified a strong local signal at 6p21.32-21.33 (chromosome 6: 31571218-32682664) (P = 1.39E-5). Ten important common SNPs were found. Hypothyroidism had a causal effect on AM, but not vice versa. Genetic association between hypothyroidism and AM in blood were enriched in Genotype-Tissue Expression (GTEx) data. In addition, two potentially functional genes, PPM1F and RPL23AP1, were identified to be associated with both hypothyroidism and AM. Limitations, reasons for caution Hypothyroidism encompasses primary and secondary forms, and due to limited data availability, our study could not perform phenotype-specific analyses. Second, even though our research identified genes associated with hypothyroidism and AM, more experimental research and long-term studies are required to fully understand the biological mechanisms underlying the observed genetic relationships. Wider implications of the findings Our study, thorough genome-wide cross-trait analysis, reveals a shared genetic architecture and causal relationship between hypothyroidism and AM. These may open up a new avenue for future research between hypothyroidism and AM. Trial registration number Not applicable

Resolving the “megacryst paradox”: Feldspar orientation relationships record crystal mobility in granites

K-feldspar megacrysts are common in silicic plutons, but there is a long-running debate around how they form and what their presence tells us about magmatic systems. Field, textural, and geochemical evidence supports growth in a melt-rich environment, but experimental evidence and phase-equilibria modeling indicate that K-feldspar grows late in the crystallization sequence, when the magma is highly crystalline. We provide a new perspective on this problem by examining the arrangement of plagioclase inclusions within megacrysts to test whether they exhibit the systematic low-energy crystallographic relationships expected from attachment by synneusis in melt-rich environments where crystals have space to rotate. We use electron backscatter diffraction to quantify the crystal orientations and find that the megacrysts’ plagioclase inclusions do occupy these preferred orientations and therefore were incorporated in a melt-rich environment. K-feldspar is also present as an interstitial network, but plagioclase crystals hosted within this network have non-systematic orientations. This transition from systematic to non-systematic plagioclase orientations marks the point at which the crystals formed a rigid, interconnected framework that impeded rotation into low-energy orientations. Phase-equilibria modeling indicates that this transition occurred when the magma was ∼55% crystalline. The remaining ∼45% melt crystallized at the eutectic, forming the interstitial phases. Thus, we resolve the “megacryst paradox”; the megacrysts grew freely in melt, and the groundmass K-feldspar formed after crystal lock-up. Megacrysts therefore provide a detailed textural and chemical record of a critical period in the system’s evolution: the transition from a mobile and potentially eruptible magma to an immobile mush.

Lifetime trauma exposure and arthritis in older adults.

Experiencing potentially traumatic events across one's lifecourse increases risk for poor physical health outcomes. Existing models emphasize the effects of any lifetime trauma exposure, risk accumulation (multiple traumas over time), and sensitive periods of exposure (specific exposure timepoints leading to lasting consequences). We examined how different indices of trauma exposure across the lifecourse were associated with later life arthritis, a common and debilitating health condition. Data include 5,717 Health and Retirement Study participants (age mean = 65.3, SD = 12.9) who reported on lifetime adversity and trauma in 2006-2008. Lifetime trauma exposure was modeled as any trauma, accumulation of traumas, and lifecourse profiles (no exposure, childhood only, adulthood only, childhood and adulthood exposure). Outcomes included prevalent arthritis at baseline and incident arthritis across 12 years of follow-up. Covariate-adjusted generalized linear models for prevalence ratios (PR) and Cox proportional hazards models for hazard ratios (HR) were conducted. Any lifetime trauma was associated with both prevalent arthritis at baseline (PR = 1.13, 95%CI 1.05-1.22) and incident arthritis over 12 years (HR = 1.25, 95%CI 1.17-1.47). Greater trauma accumulation was significantly associated with both prevalent and incident arthritis. Childhood exposure was particularly strongly associated with prevalent and incident cases, with adulthood exposure being unassociated with incident arthritis. Across models, trauma exposure was associated with prevalent cases of both immune-related and osteoarthritis types. Higher lifetime trauma burden, especially during childhood, may predispose individuals to arthritis later in life. Early intervention or prevention efforts should identify trauma as an important risk factor for musculoskeletal health across the lifecourse.

Empirical Research on Factors Influencing Chinese Farmers’ Adoption of Green Production Technologies

During a critical period of structural reform in China’s agricultural supply chain, accelerating the promotion and application of green production technologies emerges as a pivotal strategy to ensure the quality and safety of agricultural products while advancing agricultural modernization. This study empirically examines the factors influencing farmers’ adoption of green production technologies using an ordered logistic model based on survey data collected from 533 respondents in Shandong Province. The survey targeted regions where major economic crops such as corn and soybeans are cultivated, employing simple random sampling to ensure the data’s representativeness and reliability. The findings underscore several critical factors influencing farmers’ willingness to adopt green production technologies, including the presence of quality inspections, evaluations of restrictions on prohibited pesticide use, sales performance of green products, availability of government subsidies, and traceability of agricultural products. To foster greater adoption of green production technologies and propel the transformation of China’s agriculture, it is recommended to advocate and guide green agricultural practices, enhance green agricultural subsidy policies, and strengthen agricultural product market management systems. These measures are essential for ensuring sustainable agricultural development in China.

Dendritic morphology of developing hippocampal neurons in Cyp11a1 null mice.

Neurosteroids have a variety of neurological functions, such as neurite growth, neuroprotection, myelination, and neurogenesis. P450scc, encoded by CYP11A1 gene, is the cholesterol side chain cleavage enzyme that catalyzes the first and rate limiting step in the steroidogenesis. In this study, we examine the dendritic morphology in developing hippocampal neurons of Cyp11a1 null mice at P15, a critical period for synapse formation and maturation. Knockout mice were maintained until P15 with hormone administration. The Golgi-Cox method stained CA1 and CA3 pyramidal neurons in the hippocampus to reveal dendritic morphology. We demonstrated that Cyp11a1 null mice usually die within 7 days after birth and thus collected brain samples at postnatal day 5 (P5) for examination. There were significant shrinkage of dendrite size and diminishment of dendritic branching in CA1 and CA3 pyramidal neurons in the hippocampus of Cyp11a1 null mice, suggesting a developmental delay. We wonder if this delay may catch up later in life. Since the age of P15 is a critical period for synapse formation and maturation, the Cyp11a1 null mice were rescued by receiving hormone administration until P15 that the dendritic morphology in the developing hippocampal neurons could be examined. The results indicated that the total dendritic length, number of dendritic branches, as well as dendritic arborization in the CA1 and CA3 pyramidal neurons are significantly decreased in P15 knockout mice when compared to the wild type. The spine densities were also significantly decreased. In addition, the western blot analysis revealed decrease PSD-95 expression levels in the knockout mice compared to the wild type at P15. These results suggested that Cyp11a1 deficiency impairs the dendritic structures in the developing hippocampal pyramidal neurons.

Selonsertib, an ASK1 Inhibitor, Ameliorates Ovalbumin-Induced Allergic Asthma during Challenge and Sensitization Periods.

Apoptosis signal-regulating kinase 1 (ASK1) is an upstream signaling molecule in oxidative stress-induced responses. Because oxidative stress is involved in asthma pathogenesis, ASK1 gene deficiency was investigated in animal models of allergic asthma. However, there is no study to investigate whether ASK1 inhibitors could be applied for asthma to date. Selonsertib, a potent and selective ASK1 inhibitor, was applied to BALB/c mice of an ovalbumin (OVA)-induced allergic asthma model. Selonsertib suppressed antigen-induced degranulation of RBL-2H3 mast cells in a concentration-dependent manner. The administration of selonsertib both before OVA sensitization and OVA challenge significantly reduced airway hyperresponsiveness, and suppressed eosinophil numbers and inflammatory cytokine levels in the bronchoalveolar lavage fluid. Histopathologic examination elucidated less inflammatory responses and reduced mucin-producing cells around the peribronchial regions of the lungs. Selonsertib also suppressed the IgE levels in serum and the protein levels of IL-13 in the bronchoalveolar lavage fluid. These results suggest that selonsertib may ameliorate allergic asthma by suppressing immune responses and be applicable to allergic asthma.

Impacts of frost heave susceptibility and temperature-changing conditions on freeze-thaw deterioration of welded tuffs

Damage development in rocks by freeze-thaw cycles, a phenomenon that is typical to cold regions, is known to reduce the strength and durability of structures. In this study, a series of freeze-thaw tests were performed on frost and non-frost heave rocks to examine the impact of frost heave susceptibility and temperature-changing conditions on rock behaviors. The freeze-thaw life and uniaxial compressive strength (UCS) of rocks subjected to freeze-thaw cycles were estimated using a model that was based on fatigue damage mechanisms. Furthermore, we proposed a method for estimating the freeze-thaw life of rocks, using expansive strain as an important factor. The results indicated that the Shikotsu welded tuff (a non-frost heave rock) exhibited higher durability than the Noboribetsu welded tuff (a frost heave rock); this may be because the Shikotsu welded tuff had a larger pore radius and more unsaturated pores. The one-dimensional (1D) cooling-heating conditions induced significantly less damage than the three-dimensional (3D) conditions, owing to the continuous migration of free water into the unfrozen zone. The damage model estimated that for the Noboribetsu welded tuff, the freeze-thaw life in the 1D conditions was approximately eight times longer than that in the 3D conditions. Notably, with respect to the Shikotsu welded tuff, a critical freeze-thaw period induced significant expansion, resulting in damage development in the tuff. The freeze-thaw life of each rock sample was estimated based on the magnitude of the volumetric expansive strain. This study contributes to the rational assessment of the stability and durability of rock structures in cold regions.

Family Influence on Student Mental Health and Academic Achievement in University Transition

This study explores the crucial role of social support in facilitating the transition of adolescents from high school to university, focusing on two respondents, BM and MM. BM, in his second semester at a state university, struggles with the challenges of living independently in a boarding house, feeling significant emotional strain due to limited parental communication. MM, a student at a private university, maintains a close and supportive relationship with his father, despite the absence of his mother since he was two years old. The research highlights the importance of different types of social support—appraisal, belonging, and tangible—in aiding students' adaptation to university life. Appraisal support involves the availability of someone to discuss problems, while belonging support encompasses emotional and task-related assistance from family members. Tangible support refers to material assistance provided by parents. The findings indicate that effective social support, particularly from family, is essential for promoting mental health, academic success, and overall well-being during this critical transition period. The study underscores the need for future research to explore these dynamics further, considering broader cultural and socio-economic contexts that influence the availability and effectiveness of social support.

Hypersensitivity of the nicotinic acetylcholine receptor subunit (CHRNA2L9′S/L9′S) in female adolescent mice produces deficits in nicotine-induced facilitation of hippocampal-dependent learning and memory

Adolescence is characterized by a critical period of maturation and growth, during which regions of the brain are vulnerable to long-lasting cognitive disturbances. Adolescent exposure to nicotine can lead to deleterious neurological and psychological outcomes. Moreover, the nicotinic acetylcholine receptor (nAChR) has been shown to play a functionally distinct role in the development of the adolescent brain. CHRNA2 encodes for the α2 subunit of nicotinic acetylcholine receptors associated with CA1 oriens lacunosum moleculare GABAergic interneurons and is associated with learning and memory. Previously, we found that adolescent male hypersensitive CHRNA2L9′S/L9′ mice had impairments in learning and memory during a pre-exposure-dependent contextual fear conditioning task that could be rescued by low-dose nicotine exposure. In this study, we assessed learning and memory in female adolescent hypersensitive CHRNA2L9′S/L9′ mice exposed to saline or a subthreshold dose of nicotine using a hippocampus-dependent task of pre-exposure-dependent contextual fear conditioning. We found that nicotine-treated wild-type female mice had significantly greater improvements in learning and memory than both saline-treated wild-type mice and nicotine-treated CHRNA2L9′S/L9′ female mice. Thus, hyperexcitability of CHRNA2 in female adolescent mice ablated the nicotine-mediated potentiation of learning and memory seen in wild-types. Our results indicate that nicotine exposure during adolescence mediates sexually dimorphic patterns of learning and memory, with wild-type female adolescents being more susceptible to the effects of sub-threshold nicotine exposure. To understand the mechanism underlying sexually dimorphic behavior between hyperexcitable CHRNA2 mice, it is critical that further research be conducted.