Effects Of Sex Research Articles

The calcium-sensing-receptor (CaSR) in adipocytes contributes to sex-differences in the susceptibility to high fat diet induced obesity and atherosclerosis

Female mice are more resistant to obesogenic effects of a high-fat diet (HFD), compared to male mice. Although the underlying mechanisms are poorly understood, sex hormones seem to play an important role. Interestingly, the activity of the oestrogen receptor-α (ERα) is affected by the calcium-sensing-receptor (CaSR). Therefore, we investigated sex-differences upon diet-induced obesity and the role of adipocyte-specific CaSR herein. Adipocyte-specific Casr deficient mice (AdipoqCre+Casrflox) and control mice (Casrflox) were injected with AAV8-PCSK9 to make them prone to develop atherosclerosis and fed an obesity-inducing diet for 12 weeks. Female mice have lower visceral white adipose tissue (vWAT) mass compared to male mice, while this sex-difference is abolished upon adipocyte-specific Casr deficiency. Furthermore, while females showed elevated levels of inflammatory cytokines and CD3+CD8+ T cell accumulation in vWAT, compared to males, adipocyte-specific Casr deficiency abrogated this sex-phenotype and demonstrated an inhibition of inflammatory signalling pathways. The expression of Erα, as well as associated genes involved in adipocyte differentiation, was increased in female mice in a mostly adipocyte-specific Casr dependent manner. Interestingly, circulating lipid levels were reduced in female compared to male mice, which correlated with decreased atherosclerotic plaque formation. These systemic effects were abrogated upon adipocyte-specific Casr deficiency. Our findings indicate that female mice show a more pronounced vWAT dysfunction compared to males upon obesity. This sex effect is abolished upon adipocyte-specific Casr deficiency. In contrast, females show diminished atherosclerotic plaque formation compared to males, an effect that was abrogated by adipocyte-specific Casr deficiency. This work was supported by a grant from the Interdisciplinary Center for Clinical Research within the faculty of Medicine at the RWTH Aachen University, by the Corona Foundation, by the Deutsche Forschungsgemeinschaft (DFG), the BMBF and Free State of Bavaria and the DZHK.

Perineuronal nets' role in metabolism.

Perineuronal nets (PNNs), specialized extracellular matrix (ECM) structures that envelop neurons, have recently been recognized as key players in the regulation of metabolism. This review explores the growing body of knowledge concerning PNNs and their role in metabolic control, drawing insights from recent research and relevant studies. The pivotal role of PNNs in the context of energy balance and whole body blood glucose is examined. This review also highlights novel findings, including the effects of astroglia, microglia, sex and gonadal hormones, nutritional regulation, circadian rhythms, and age on PNNs dynamics. These findings illuminate the complex and multifaceted role of PNNs in metabolic health.

Fetal sex effects on maternal health can now be tested via randomization: A first-in-class illustration in cows on glucoregulatory outcomes

BackgroundThe maternal-offspring relationship, such as whether fetal sex influences maternal health, is essential to explore to advance prenatal and maternal health. While associations exist between fetal sex and maternal health outcomes, it is unclear whether these reflect a causal relationship. ObjectiveTo demonstrate that fetal sex can be randomly assigned to test the causal effect of fetal sex on maternal outcomes. MethodsHolstein dairy cows were stratified and randomized using sealed opaque envelopes to be artificially inseminated with either X- or Y-sorted bull semen until 40 cows became pregnant. Monthly body weight measurements were recorded, and an intravenous glucose tolerance test was performed 30 days before the expected calving day. The primary outcome was insulin area under the curve (AUC), and secondary outcomes were clearance rate, half-life, and AUC for glucose, insulin, and non-esterified fatty acid concentrations. An intention-to-treat (ITT) approach using multiple imputation was employed for primary analysis, and an as-treated (AT) approach was used for secondary analysis. ResultsWe demonstrated that we could successfully randomize the assignment of fetal sex to dams and test for causal effects of fetal sex on glucoregulatory outcomes using dairy cows as a model. Insulin AUC was not statistically different between groups (ITT p = 0.857, AT p = 0.874), and other outcomes were also not statistically different (p > 0.05). ConclusionWe demonstrated that causal effects of fetal sex on maternal outcomes can be causally tested in dairy cows. Our study did not provide statistical evidence to support an effect of fetal sex on maternal glucose-related outcomes.

Long-term changes in adiposity markers during and after antidepressant therapy in a community cohort

Research on antidepressant-related weight changes over more than 12 months is scarce and adjustment for the effects of depressive episodes has rarely been applied. Accordingly, our aim was to assess the associations of the use of any antidepressants, subclasses of antidepressant and specific compounds prior to baseline and during a 5.5-year follow-up with changes in adiposity markers, and the effect of sex on these associations, with adjustment for multiple confounders including the effects of depressive episodes and their severity. Data stemmed from a prospective cohort study including 2479 randomly selected 35–66 year-old residents of an urban area (mean age 49.9 years, 53.3% women) who underwent physical and psychiatric evaluations at baseline and follow-up. Weight, height, waist circumference, and body fat were measured by trained nurses and information on diagnosis and antidepressant use prior to baseline and during follow-up was collected through standardized interviews. In the fully adjusted models, the number of antidepressants, mainly SSRIs and TCAs, used prior to baseline, was associated with a lower increase of body-mass index (BMI, β (95%CI) = −0.12 (−0.19, −0.05)) and waist circumference (β = −0.28 (−0.56, −0.01)), whereas participants treated with antidepressants during the follow-up had a steeper increase in BMI (β = 0.32 (0.13, 0.50)) and waist circumference (β = 1.23 (0.44, 2.01)). Within the class of SSRIs, the use of fluoxetine, sertraline or escitalopram during follow-up was associated with a steeper increase in adiposity markers. The associations of SSRIs with BMI and waist circumference were only observed when the SSRIs were used during the second period of the follow-up. Sex did not moderate these associations. Our findings suggest an increase of adiposity markers during sustained treatment with TCAs and SSRIs, which however return to normal levels after cessation of treatment. Hence, the benefit of long-term administration of these antidepressants should be carefully weighed against the potential risk of weight gain.

FGF21 mediating the Sex-dependent Response to Dietary Macronutrients.

Sex is key variable influencing body composition and substrate utilization. At rest, females maintain greater adiposity than males and resist the mobilization of fat. Males maintain greater lean muscle mass and mobilize fat readily. Determining the mechanisms that direct these sex-dependent effects is important for both reproductive and metabolic health. Here, we highlight the fundamental importance of sex in shaping metabolic physiology and assess growing evidence that the hepatokine fibroblast growth factor-21 (FGF21) plays a mechanistic role to facilitate sex-dependent responses to a changing nutritional environment. First, we examine the importance of sex in modulating body composition and substrate utilization. We summarize new data that point toward sex-biased effects of pharmacologic FGF21 administration on these endpoints. When energy is not limited, metabolic responses to FGF21 mirror broader sex differences; FGF21-treated males conserve lean mass at the expense of increased lipid catabolism, whereas FGF21-treated females conserve fat mass at the expense of reduced lean mass. Next, we examine the importance of sex in modulating the endogenous secretion of FGF21 in response to changing macronutrient and energy availability. During the resting state when energy is not limited, macronutrient imbalance increases the secretion of FGF21 more so in males than females. When energy is limited, the effect of sex on both the secretion of FGF21 and its metabolic actions may be reversed. Altogether, we argue that a growing literature supports FGF21 as a plausible mechanism contributing to the sex-dependent mobilization vs preservation of lipid storage and highlight the need for further research.

Insights from neighbourhood walking interviews using the Living Environments and Active Aging Framework (LEAAF) in community-dwelling older adults

We aimed to understand whether neighbourhood characteristics are associated with movement and social behaviors using walking interviews with 28 community-dwelling older adults (aged 65+). Results indicated support for each component and each relationship in our proposed “Living Environments and Active Aging Framework”. Additional themes such as neighbourhoods with children, moving to neighbourhoods with opportunities for social activity and movement, and lingering effects of pandemic closures provided novel insights into the relationship between the living environment (neighbourhood) and active aging. Future work exploring sex and gender effects on these relationships, and work with equity-deserving groups is needed.

Sex Disparity in the In-Hospital Outcomes of Patients with Kidney Disease Admitted for Myocardial Infarction: Insights from a Large National Database.

There is limited evidence as to the effect of sex on the outcomes of patients admitted for ST-elevation myocardial infarction (STEMI) who have a concomitant diagnosis of chronic kidney disease (CKD) and end-stage renal disease (ESRD). We aimed to determine if there are differences in the outcomes between males and females in these patient populations. Data were obtained from the National Inpatient Sample database and patients were selected using the International Classification of Diseases, Ninth and Tenth Revision (ICD-9 and -10) codes. Hospitalizations for patients with CKD who had STEMI from 2012 to 2020 were included. The primary outcome of interest was in-hospital mortality. Secondary outcomes evaluated included ischemic stroke, major bleeding complications, pressor requirement, permanent pacemaker implantation, percutaneous coronary intervention, coronary artery bypass grafting, surgery, pericardiocentesis, mechanical circulatory support, and mechanical ventilation. A total of 1,283,255 STEMI patients without CKD, 158,715 STEMI patients with CKD, and 22,690 STEMI patients with ESRD were identified and analyzed. Among patients with STEMI and CKD, females demonstrated higher in-hospital mortality compared to male counterparts (16.7% vs. 12.7%, aOR = 1.13, 95% CI: 1.05-1.21, p < 0.01). While there was no sex difference in the in-hospital mortality among STEMI patients with ESRD, female patients in this group were less likely to receive coronary artery bypass grafting and mechanical circulatory support. Increased in-hospital mortality rates were shown for females admitted for STEMI with CKD. Among patients with ESRD who had STEMI, females were less likely to receive coronary artery bypass grafting and mechanical circulatory support. Further research needs to be conducted to better explain this said difference in outcomes.

Sex of an Observer Effects on Adults' Motor, Cognitive, and Affective Dart-Shooting Performance.

Men and women are characterized by specific physiological, cerebral and emotional characteristics, as well as by the differing nature of their gestures and behaviors. Here, we examined the effects of an observer's sex on motor, cognitive and affective behaviors during dart-shooting. We compared men and women's kinematic and affective parameters when perfoming alone or when performing in the presence of an observer of a different sex. We found a sex effect on motor and cognitive performance in interaction with participants' emotional states. We observed improved accuracy and reaction time in men compared to women, which we attributed to (a) differences in emotional sensitivities between the two sexes and (b) men's superiority on precision tasks linked to men's higher proportion of cerebral white matter. Our findings also suggested a sex difference in the social effect of an observer's sex on motor and cognitive performance. Although there was no effect on affective aspects of performance, emotional state seemed to interact strongly with this social effect.

Association of Anxiety/Depressive Symptoms with Psychotic-like Experiences: The Moderation Effect of Sex and Resilience.

Psychotic-like experiences (PLEs) are a part of the continuum of psychosis and are common in the general population. While most of these experiences are transient, they are strongly correlated with an increased risk of various adverse psychological outcomes. Anxiety and depressive symptoms also occur frequently in the adolescent population. Much research has previously demonstrated a correlation between these two symptoms and PLEs. However, few investigations have examined what influences this association, and sex and resilience may be important moderators. This study selected a sample of first-year students from a university in Shanghai. A total of 2970 adolescents completed questionnaires measuring sociodemographic characteristics, anxiety/depressive symptoms by SCL-90, resilience by CD-RISC, and self-reported PLEs by PQ-16. The findings indicated that PLEs were prevalent in the sample, with at least one PQ-16 item present in 42.5% of individuals. Anxiety/depressive symptoms were significantly associated with PLEs, and there was a sex difference in this association (p < 0.001). What is more, this relationship was stronger in males than in females. Additionally, we found a significant interaction (p < 0.001) between resilience and anxiety/depressive symptoms when looking at the correlates of PLEs. Those with stronger resilience showed a considerably weaker connection between PLEs and symptoms of anxiety and depression. These findings can potentially inform the development of targeted new clinical interventions.

Variable and interactive effects of Sex, APOE and TREM2 on the deposition of tau in entorhinal and neocortical regions.

The canonical AD pathological cascade posits that the accumulation of amyloid beta ( ) is the initiating event, accelerating the accumulation of tau in the entorhinal cortex (EC), which subsequently spreads into the neocortex. Here in a sample of over 1300 participants with multimodal imaging and genetic information we queried how genetic variation affects these stages of the AD cascade. We observed that females and homozygotes are more susceptible to the effects of on the primary accumulation of tau, with greater EC tau for a given level of . Furthermore, we observed for individuals who have rare risk variants in Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) and/or homozygotes there was a greater spread of primary tau from the EC into the neocortex. These findings offer insights into the function of sex, APOE and microglia in AD progression, and have implications for determining personalised treatment with drugs targeting and tau.

Diagnostic yield from symptomatic gastroscopy in the UK: British Society of Gastroenterology analysis using data from the National Endoscopy Database

ObjectiveThis national analysis aimed to calculate the diagnostic yield from gastroscopy for common symptoms, guiding improved resource utilisation.DesignA cross-sectional study was conducted of diagnostic gastroscopies between 1 March 2019 and...

Association between the triglyceride–glucose index and serum soluble Klotho in middle-aged and older adults from NHANES 2007–2016

Klotho, an anti-aging protein, is believed to participate in metabolic diseases and play a potential protective role by regulating insulin sensitivity. This study aimed to explore the relationship between the triglyceride-glucose (TyG) index (a simple marker of insulin resistance) and serum soluble Klotho (S-Klotho) levels. The cross-sectional study comprised 5237 adults aged 40–79 years who participated in the National Health and Nutrition Examination Surveys (NHANES) 2007–2016. The TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. The serum levels of S-Klotho were measured by enzyme-linked immunosorbent assay. The association between the TyG index and S-Klotho levels was investigated by multiple linear regression models, smoothed curve fitting, segmented linear regression models, subgroup analyses, and interaction tests. The TyG index was inversely associated with serum S-Klotho level after full adjustment (β = − 45.11, 95% CI (− 79.53, − 10.69), P = 0.011). Furthermore, we also found a non-linear correlation and saturation phenomenon between the TyG index and serum S-Klotho levels, with a turning point of 9.56. In addition, a significant interaction effect of sex was found between the two (P for interaction < 0.001), with a more pronounced association observed in females. Further studies are required to explore the mechanisms and verify the correlation.

Preparedness and Anxiety of Dental Students in the Transition from Preclinical to Clinical Practice

Aim: This study aimed to investigate the preparedness and anxiety levels of dental students transitioning to clinical practice and to examine the effects of sex, university, and observations. Material and Method: A total of 182 students (58 male, 124 female) transitioning from preclinical to clinic participated in the study. The survey consisted of sections covering socio-demographic data, students' opinions on their preparedness for clinical practice, anxiety levels measured by the State-Trait Anxiety Inventory (STAI), and confidence levels in various skill areas. Spearman's Rank correlation test was used for correlation analysis, while the Mann Whitney-U test for pairwise group comparisons. Results: No differences were found in preparedness between sexes, but males exhibited significantly higher confidence in various dental skills. Conversely, females reported significantly higher levels of state and trait anxiety. State university students (n=48) reported heightened workload expectations and elevated levels of state and trait anxiety. Conversely, private university students (n=134) demonstrated increased confidence and preparedness in dental practice-related knowledge and skills. Students who participated in observations (n=96) had lower preparedness and confidence levels in several dental areas, coupled with higher trait anxiety levels, compared to their peers who did not participate in observations (n=86). Finally, STAI scores were positively correlated with workload, negatively correlated with knowledge, skills, and confidence. Conclusion: Sex, school, and observation status have an impact on students' preparedness for clinical education, anxiety, and confidence in their professional abilities. Therefore, assessments and orientation programs that take these aspects into account can benefit students at this time of change.

Sex, tissue, and mitochondrial interactions modify the transcriptional response to rapamycin in Drosophila

BackgroundMany common diseases exhibit uncontrolled mTOR signaling, prompting considerable interest in the therapeutic potential of mTOR inhibitors, such as rapamycin, to treat a range of conditions, including cancer, aging-related pathologies, and neurological disorders. Despite encouraging preclinical results, the success of mTOR interventions in the clinic has been limited by off-target side effects and dose-limiting toxicities. Improving clinical efficacy and mitigating side effects require a better understanding of the influence of key clinical factors, such as sex, tissue, and genomic background, on the outcomes of mTOR-targeting therapies.ResultsWe assayed gene expression with and without rapamycin exposure across three distinct body parts (head, thorax, abdomen) of D. melanogaster flies, bearing either their native melanogaster mitochondrial genome or the mitochondrial genome from a related species, D. simulans. The fully factorial RNA-seq study design revealed a large number of genes that responded to the rapamycin treatment in a sex-dependent and tissue-dependent manner, and relatively few genes with the transcriptional response to rapamycin affected by the mitochondrial background. Reanalysis of an earlier study confirmed that mitochondria can have a temporal influence on rapamycin response.ConclusionsWe found significant and wide-ranging effects of sex and body part, alongside a subtle, potentially time-dependent, influence of mitochondria on the transcriptional response to rapamycin. Our findings suggest a number of pathways that could be crucial for predicting potential side effects of mTOR inhibition in a particular sex or tissue. Further studies of the temporal response to rapamycin are necessary to elucidate the effects of the mitochondrial background on mTOR and its inhibition.

Differential Effect of Sex on Mortality According to Age in Heart Failure.

Heart failure exhibits sex-based differences in prevalence, clinical characteristics, and outcomes. However, these differences may have an interaction with age. This study investigates these disparities in Asian patients with acute heart failure according to age. We pooled data from the KorHF (Korea Heart Failure) and the KorAHF (Korean Acute Heart Failure) registries including 3200 patients between 2005 and 2009 and 5625 patients between 2011 and2014, respectively, hospitalized for acute heart failure in Korea. Patients were categorized by their age into 2 groups: those with age ≥70 years and those with age <70 years. The primary endpoint was in-hospital and postdischarge outcomes according to sex, stratified by age. Of 8825 patients, 45.7% had an age <70 years, and 54.3% had an age ≥70 years. Women were older on average in both groups. Differences in baseline characteristics were more apparent in the older group, with women having a higher prevalence of hypertension and valvular heart disease, whereas more men had chronic kidney disease, previous myocardial infarction, chronic obstructive pulmonary disease, and strokes. Both in-hospital and postdischarge mortalities showed differences only in the older group, with men dying more (5.08% versus 7.41%, P<0.001; 17.95% versus 22.20%, P<0.001 respectively). This pattern persisted to adjusted analyses, which revealed that men have a 54% (odds ratio, 1.54 [95% CI, 1.17-2.04]) and 30% (hazard ratio, 1.30 [95% CI, 1.13-1.51]) increased in-hospital and 1-year mortality, respectively, compared with women. In patients hospitalized with acute heart failure, male sex is an independent predictor of mortality in older patients but not younger patients.

Cull guinea pigs: carcass and non-carcass traits in males and females compared to their fattening counterparts.

Culling of guinea pigs can provide a large number of animals per year for meat production, but little information is available in the scientific literature on the carcass characteristics and non-carcass components of these animals. The objective of this study was to evaluate the carcass and non-carcass characteristics of cull guinea pigs in comparison to their fattening counterparts. Forty-eight fattening (3 months-age, 24 females and 24 males) and forty-eight cull (14 months-age, 24 females and 24 males) guinea pigs were slaughtered and carcass yield, linear measurements, tissular composition, and non-carcass components were evaluated. In general, cull guinea pigs had higher carcass, tissue, and non-carcass component weights. Cull male and both female guinea pig groups had similar carcass yields. Cull animals had higher carcass and hind leg lengths, lumbar and thoracic circumferences, and carcass compactness than their young counterparts. However, a sex effect was found for leg compactness depending on whether they were fattened or cull. Tissue percentages values were similar between fattening and culling animals of the same sex. However, females had a higher percentage of fat tissue than males. Fattening females had the best muscle to bone ratio, followed by cull males. The non-carcass elements were more represented in fattening animals than in culls, probably due to an allometric growth of the viscera in relation to the rest of the body. In commercial and cooking terms, this information is valuable for producers and researchers who need to understand the factors that influence carcass characteristics of guinea pigs.

A competing risks machine learning study of neutron dose, fractionation, age, and sex effects on mortality in 21,000 mice

This study explores the impact of densely-ionizing radiation on non-cancer and cancer diseases, focusing on dose, fractionation, age, and sex effects. Using historical mortality data from approximately 21,000 mice exposed to fission neutrons, we employed random survival forest (RSF), a powerful machine learning algorithm accommodating nonlinear dependencies and interactions, treating cancer and non-cancer outcomes as competing risks. Unlike traditional parametric models, RSF avoids strict assumptions and captures complex data relationships through decision tree ensembles. SHAP (SHapley Additive exPlanations) values and variable importance scores were employed for interpretation. The findings revealed clear dose–response trends, with cancer being the predominant cause of mortality. SHAP value dose–response shapes differed, showing saturation for cancer hazard at high doses (> 2 Gy) and a more linear pattern at lower doses. Non-cancer responses remained more linear throughout the entire dose range. There was a potential inverse dose rate effect for cancer, while the evidence for non-cancer was less conclusive. Sex and age effects were less pronounced. This investigation, utilizing machine learning, enhances our understanding of the patterns of non-cancer and cancer mortality induced by densely-ionizing radiations, emphasizing the importance of such approaches in radiation research, including space travel and radioprotection.

The metabolic cost of breathing for exercise ventilations: effects of age and sex.

Given that there are both sex-based structural differences in the respiratory system and age-associated declines in pulmonary function, the purpose of this study was to assess the effects of age and sex on the metabolic cost of breathing (V̇o2RM) for exercise ventilations in healthy younger and older males and females. Forty healthy participants (10 young males 24 ± 3 yr; 10 young females 24 ± 3 yr; 10 older males 63 ± 3 yr, 10 older females 63 ± 6 yr) mimicked their exercise breathing patterns (voluntary hyperpnea) in the absence of exercise across a range of exercise intensities. At peak exercise, V̇o2RM represented a significantly greater fraction of peak oxygen consumption (V̇o2peak) in young females, 12.7 ± 4.0%, compared with young males, 10.7 ± 3.0% (P = 0.027), whereas V̇o2RM represented 13.5 ± 2.3% of V̇o2peak in older females and 13.2 ± 3.3% in older males. At relative ventilations, there was a main effect of age, with older males consuming a significantly greater fraction of V̇o2RM (6.6 ± 1.9%) than the younger males (4.4 ± 1.3%; P = 0.012), and older females consuming a significantly greater fraction of V̇o2RM (6.9 ± 2.5%) than the younger females (5.1 ± 1.4%; P = 0.004) at 65% V̇emax. Furthermore, both younger and older males had significantly better respiratory muscle efficiency than their female counterparts at peak exercise (P = 0.011; P = 0.015). Similarly, younger participants were significantly more efficient than older participants (6.5 ± 1.5% vs. 5.5 ± 2.0%; P = 0.001). Normal age-related changes in respiratory function, in addition to sex-based differences in airway anatomy, appear to influence the ventilatory responses and the cost incurred to breathe during exercise.NEW & NOTEWORTHY Here we show that at moderate and high-intensity exercise, older individuals incur a higher cost to breathe than their younger counterparts. However, as individuals age, the sex difference in the cost of breathing narrows. Collectively, our findings suggest that the normative age-related changes in respiratory structure and function, and sex differences in airway anatomy, appear to influence the ventilatory responses to exercise and the oxygen cost to breathe.

Dynamics of a goshawk population across half a century is driven by the variation of first-year survival.

Population dynamics are driven by stochastic and density-dependent processes acting on demographic rates. Individuals differ demographically, and to capture these differences, models of population dynamics are usually structured by age and stage, rarely by sex. An effect of sex on population dynamics is expected if the dynamics of males and females differ, requiring an unequal sex ratio at birth and/or sex-specific survival probabilities. Goshawks (Accipiter gentilis) show large sexual size dimorphism and differential survival, but it is unknown whether males and females contribute differently to population dynamics. We studied a goshawk population in northern Germany over 47 years using brood monitoring data, collected feathers and nestling ringing data. We jointly analyzed the data using a two-sex integrated population model and performed retrospective and prospective population analyses to understand whether the demographic drivers of population change differ between the sexes. The population showed large fluctuations, during which the number of breeding pairs doubled, but the long-term trend of the population was slightly negative. Female survival exceeded male survival during the first year of life. Females started to reproduce at a younger age than males, productivity increased with female age, the sex ratio of nestlings was male biased and there was moderate male immigration. Despite these differences, temporal variation in sex ratio did not contribute to population dynamics and the contribution of temporal variation in survival was similar for both sexes. Variation in first-year survival was the strongest driver in this population, regulated by a weak density-dependent feedback acting through female first-year survival. Overall, the contributions of the two sexes to population dynamics were similar in this monogamous species with strong sexual size dimorphism.

Reference Standard of Median Nerve Conduction Study in Korea.

To establish the reference standard of the median nerve conduction study (NCS) in Korea. A total of 648 median motor and 602 median sensory NCSs from 349 Korean healthy volunteers were tested and analyzed prospectively. Equipment calibration, assessment of intraand inter-rater reliability, and the NCSs per se were conducted according to a predetermined protocol. A reference standard was established from uncertainty components for the following parameters: the onset and peak latencies; the baseline-to-peak and peak-to-peak amplitudes; the area and duration of the negative wave; and the nerve conduction velocity. The effects of sex, age and stimulation intensity were analyzed. Each measured value of 648 median motor and 602 median sensory nerves were obtained and presented with both mean and expanded uncertainties, as well as mean and standard deviations. The cut-off values with expanded uncertainty were determined for different age and sex groups. After adjusting for anthropometric covariates, all parameters except duration were affected by age, and sex appeared to influence both duration and area. While stimulation intensity significantly affected some parameters including latencies, the effect sizes were negligible. We propose the median NCS reference standard using the largest Korean dataset ever available. The use of the traceable and reliable reference standard is anticipated to promote more accurate and dependable diagnosis and appropriate management of median neuropathies in Korea.