Age-dependent Patterns Research Articles

COVID-19: A Challenge to Physiology of Aging.

The death toll of the current COVID-19 pandemic is strongly biased toward the elderly. COVID-19 case fatality rate (CFR) increases with age exponentially, its doubling time being about 7 years, irrespective of countries and epidemic stages. The same age-dependent mortality pattern known as the Gompertz law is featured by the total mortality and its main constituents attributed to cardiovascular, metabolic, neurological, and oncological diseases. Among patients dying of COVID-19, most have at least one of these conditions, whereas none is found in most of those who pass it successfully. Thus, gerontology is indispensable in dealing with the pandemic, which becomes a benchmark for validating the gerontological concepts and advances. The two basic alternative gerontological concepts imply that either aging results from the accumulation of stochastic damage, or is programmed. Based on these different grounds, several putative anti-aging drugs have been proposed as adjuvant means for COVID-19 prevention and/or treatment. These proposals are reviewed in the context of attributing the molecular targets of these drugs to the signaling pathways between the sensors of resource availability and the molecular mechanisms that allocate resources to storage, growth and reproduction or to self-maintenance and repair. Each of the drugs appears to reproduce only a part of the physiological responses to reduced resource availability caused by either dietary calories restriction or physical activity promotion, which are the most robust means of mitigating the adverse manifestations of aging. In the pathophysiological terms, the conditions of the endothelium, which worsen as age increases and may be significantly improved by the physical activity, is a common limiting factor for the abilities to withstand both physical stresses and challenges imposed by COVID-19. However, the current anti-epidemic measures promote sedentary indoor lifestyles, at odds with the most efficient behavioral interventions known to decrease the vulnerability to both the severe forms of COVID-19 and the prevalent aging-associated diseases. To achieve a proper balance in public health approaches to COVID-19, gerontologists should be involved in crosstalk between virologists, therapists, epidemiologists, and policy makers. The present publication suggests a conceptual background for that.

Treatment with Cinacalcet in Hemodialysis Patients with Severe Secondary Hyperparathyroidism, Influences Bone Mineral Metabolism and Anemia Parameters

Background: Due to the premium rate of Chronic Kidney Disease, we have increased our knowledge with respect to diagnosis and treatment of Bone Mineral Disease (BMD) in End- Stage Renal Disease (ESRD). Currently, various treatment options are available. The medication used for Secondary Hyper-Parathyroidism gives promising results in the regulation of Ca, P and Parathormone levels, improving the quality of life. The aim of the present study was to investigate the relation of cinacalcet administration to not only parathormone, Ca and P but also to anemia parameters such as hematocrit and hemoglobin. Materials and Methods: retrospective observational study was conducted in a Chronic Hemodialysis Unit. One-hundred ESRD patients were recruited for twenty-four months and were evaluated on a monthly rate. Biochemical parameters were related to medication prescribed and the prognostic value was estimated. Cinacalcet was administered to 43 out of 100 patients in a dose of 30-120 mg. Results: Significant differences were observed in PTH, Ca and P levels with respect to Cinacalcet administration. Ca levels appeared to be higher at 30mg as compared to 60mg cinacalcet. Furthermore, a decreasing age-dependent pattern was observed with respect to cinacalcet dosage. A positive correlation was observed between Dry Weight (DW) and cinacalcet dose. Finally, a positive correlation between Hematocrit and Hemoglobin and cinacalcet was manifested. Conclusions: Cinacalcet, is a potential cardiovascular and bone protective agent, which is approved for use in ESRD patients to assist SHPT. A novel information was obtained from this study, regarding the improvement of the control of anemia.

Host age is not a consistent predictor of microbial diversity in the coral Porites lutea

Corals harbour diverse microbial communities that can change in composition as the host grows in age and size. Larger and older colonies have been shown to host a higher diversity of microbial taxa and this has been suggested to be a consequence of their more numerous, complex and varied micro-niches available. However, the effects of host age on community structure and diversity of microbial associates remain equivocal in the few studies performed to date. To test this relationship more robustly, we use established techniques to accurately determine coral host age by quantifying annual skeletal banding patterns, and utilise high-throughput sequencing to comprehensively characterise the microbiome of the common reef-building coral, Porites lutea. Our results indicate no clear link between coral age and microbial diversity or richness. Different sites display distinct age-dependent diversity patterns, with more anthropogenically impacted reefs appearing to show a winnowing of microbial diversity with host age, possibly a consequence of corals adapting to degraded environments. Less impacted sites do not show a signature of winnowing, and we observe increases in microbial richness and diversity as the host ages. Furthermore, we demonstrate that corals of a similar age from the same reef can show very different microbial richness and diversity.

The Gut Virome Database Reveals Age-Dependent Patterns of Virome Diversity in the Human Gut

The gut microbiome profoundly affects human health and disease, and their infecting viruses are likely as important, but often missed because of reference database limitations. Here, we (1) built a human Gut Virome Database (GVD) from 2,697 viral particle or microbial metagenomes from 1,986 individuals representing 16 countries, (2) assess its effectiveness, and (3) report a meta-analysis that reveals age-dependent patterns across healthy Westerners. The GVD contains 33,242 unique viral populations (approximately species-level taxa) and improves average viral detection rates over viral RefSeq and IMG/VR nearly 182-fold and 2.6-fold, respectively. GVD meta-analyses show highly personalized viromes, reveal that inter-study variability from technical artifacts is larger than any “disease” effect at the population level, and document how viral diversity changes from human infancy into senescence. Together, this compact foundational resource, these standardization guidelines, and these meta-analysis findings provide a systematic toolkit to help maximize our understanding of viral roles in health and disease.

The role of spatial and spatial-temporal analysis in children's causal cognition of continuous processes.

Past research has largely ignored children’s ability to conjointly manipulate spatial and temporal information, but there are indications that the capacity to do so may provide important support for reasoning about causal processes. We hypothesised that spatial-temporal thinking is central to children’s ability to identify the invisible mechanisms that tie cause and effect together in continuous casual processes, which are focal in primary school science and crucial to understanding of the natural world. We investigated this in two studies (N = 107, N = 124), employing two methodologies, one shorter, the other more in depth. Further tasks assessed spatial-temporal (flow of liquid, extrapolation of relative speed, distance-time-velocity), spatial (two mental rotation, paper folding), verbal (expressive vocabulary), and nonverbal (block design) ability. Age dependent patterns were detected for both causal and predictor tasks. Two spatial-temporal tasks were unique and central predictors of children’s causal reasoning, especially inference of mechanism. Nonverbal ability predicted the simpler components of causal reasoning. One mental rotation task predicted only young children’s causal thinking. Verbal ability became significant when the sample included children from a wide range of socioeconomic backgrounds. Causal reasoning about continuous processes, including inferences of causal mechanism, appears to be within the reach of children from school entry age, but mechanism inference is uncommon. Analytic forms of spatial-temporal capacity seem to be important requirements for children to progress to this rather than merely perceptual forms.

CircGRIA1 shows an age-related increase in male macaque brain and regulates synaptic plasticity and synaptogenesis

Circular RNAs (circRNAs) are abundant in mammalian brain and some show age-dependent expression patterns. Here, we report that circGRIA1, a conserved circRNA isoform derived from the genomic loci of α-mino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subunit Gria1, shows an age-related and male-specific increase in expression in the rhesus macaque prefrontal cortex and hippocampus. We show circGRIA1 is predominantly localized to the nucleus, and find an age-related increase in its association with the promoter region of Gria1 gene, suggesting it has a regulatory role in Gria1 transcription. In vitro and in vivo manipulation of circGRIA1 negatively regulates Gria1 mRNA and protein levels. Knockdown of circGRIA1 results in an age-related improvement of synaptogenesis, and GluR1 activity-dependent synaptic plasticity in the hippocampal neurons in males. Our findings underscore the importance of circRNA regulation and offer an insight into the biology of brain aging.

O8.5. SIGNS OF ADVERSITY - A NOVEL MACHINE LEARNING APPROACH TO CHILDHOOD TRAUMA, BRAIN STRUCTURE AND CLINICAL PROFILES

BackgroundChildhood maltreatment (CM) is a major psychiatric risk factor and leads to long-lasting physical and mental health implications throughout the affected individual’s lifespan. Nonetheless, the neuroanatomical correlates of CM and their specific clinical impact remain elusive. This might be attributed to the complex, multidimensional nature of CM as well as to the restrictions of traditional analysis pipelines using nosological grouping, univariate analysis and region-of-interest approaches. To overcome these issues, we present a novel transdiagnostic and naturalistic machine learning approach towards a better and more comprehensive understanding of the clinical and neuroanatomical complexity of CM.MethodsWe acquired our dataset from the multi-center European PRONIA cohort (www.pronia.eu). Specifically, we selected 649 male and female individuals, comprising young, minimally medicated patients with clinical high-risk states for psychosis as well as recent-onset of depression or psychosis and healthy volunteers. As part of our analysis approach, we created a new Matlab Toolbox, which performs multivariate Sparse Partial Least Squares Analysis in a robust machine learning framework. We employed this algorithm to detect multi-layered associations between combinations of items from the Childhood Trauma Questionnaire (CTQ) and grey matter volume (GMV) and assessed their generalizability via nested cross-validation. The clinical relevance of these CM signatures was assessed by correlating them to a wide range of clinical measurements, including current functioning (GAF, GF), depressivity (BDI), quality of life (WHOQOL-BREF) and personality traits (NEO-FFI).ResultsOverall, we detected three distinct signatures of sexual, physical and emotional maltreatment. The first signature consisted of an age-dependent sexual abuse pattern and a corresponding GMV pattern along the prefronto-thalamo-cerebellar axis. The second signature yielded a sex-dependent physical and sexual abuse pattern with a corresponding GMV pattern in parietal, occipital and subcortical regions. The third signature was a global emotional trauma signature, independent of age or sex, and projected to a brain structural pattern in sensory and limbic brain regions. Regarding the clinical impact of these signatures, the emotional trauma signature was most strongly associated with massively impaired state- and trait-level characteristics. Both on a phenomenological and on a brain structural level, the emotional trauma pattern was significantly correlated with lower levels of functioning, higher depression scores, decreased quality of life and maladaptive personality traits.DiscussionOur findings deliver multimodal, data-driven evidence for a differential impact of sexual, physical and emotional trauma on brain structure and clinical state- and trait-level phenotypes. They also highlight the multidimensional nature of CM, which consists of multiple layers of highly complex trauma-brain patterns. In broader terms, our study emphasizes the potential of machine learning approaches in generating novel insights into long-standing psychiatric topics.

Exploratory analysis of age and sex dependent DNA methylation patterns on the X-chromosome in whole blood samples

BackgroundLarge numbers of autosomal sites are found differentially methylated in the aging genome. Due to analytical difficulties in dealing with sex differences in X-chromosome content and X-inactivation (XCI) in females, this has not been explored for the X chromosome.MethodsUsing data from middle age to elderly individuals (age 55+ years) from two Danish cohorts of monozygotic twins and the Scottish Lothian Birth Cohort 1921, we conducted an X-chromosome-wide analysis of age-associated DNA methylation patterns with consideration of stably inferred XCI status.ResultsThrough analysing and comparing sex-specific X-linked DNA methylation changes over age late in life, we identified 123, 293 and 55 CpG sites significant (FDR < 0.05) only in males, only in females and in both sexes of Danish twins. All findings were significantly replicated in the two Danish twin cohorts. CpG sites escaping XCI are predominantly de-methylated with increasing age across cohorts. In contrast, CpGs highly methylated in both sexes are methylated even further with increasing age. Among the replicated sites in Danish samples, 16 (13%), 24 (8.2%) and 3 (5.5%) CpGs were further validated in LBC1921 (FDR < 0.05).ConclusionsThe X-chromosome of whole blood leukocytes displays age- and sex-dependent DNA methylation patterns in relation to XCI across cohorts.

Structural Uncertainty in Onchocerciasis Transmission Models Influences the Estimation of Elimination Thresholds and Selection of Age Groups for Seromonitoring.

BackgroundThe World Health Organization recommends monitoring Onchocerca volvulus Ov16 serology in children aged <10 years for stopping mass ivermectin administration. Transmission models can help to identify the most informative age groups for serological monitoring and investigate the discriminatory power of serology-based elimination thresholds. Model predictions depend on assumed age-exposure patterns and transmission efficiency at low infection levels.MethodsThe individual-based transmission model, EPIONCHO-IBM, was used to assess (1) the most informative age groups for serological monitoring using receiver operating characteristic curves for different elimination thresholds under various age-dependent exposure assumptions, including those of ONCHOSIM (another widely used model), and (2) the influence of within-human density-dependent parasite establishment (included in EPIONCHO-IBM but not ONCHOSIM) on positive predictive values for different serological thresholds.ResultsWhen assuming EPIONCHO-IBM exposure patterns, children aged <10 years are the most informative for seromonitoring; when assuming ONCHOSIM exposure patterns, 5–14 year olds are the most informative (as published elsewhere). Omitting density-dependent parasite establishment results in more lenient seroprevalence thresholds, even for higher baseline infection prevalence and shorter treatment durations.ConclusionsSelecting appropriate seromonitoring age groups depends critically on age-dependent exposure patterns. The role of density dependence on elimination thresholds largely explains differing EPIONCHO-IBM and ONCHOSIM elimination predictions.

Age-specific occurrence of pathological fractures in patients with spina bifida.

Pathological fractures (PFs) are common in patients with spina bifida. However, most previous studies refer to the overall fracture rate and largely neglecting putative age-dependent aspects. The aim of this retrospective study was to characterize patterns of fracture occurrence in childhood. In a retrospective study, we identified PF, all in the lower limbs, in 13% of 210 patients with spina bifida aperta. We further identified a bimodal frequency distribution of pathological fractures, with peaks at 1-5 and 10-12 years. We could thereby distinguish two groups of patients: (i) Children with a first fracture before an age of 6 years developed frequently multiple fractures within the following years, but fracture series typically stopped by 6 years-of-age. (ii) Children with a first fracture after the age of 6 years had fewer fractures, but these occurred also in adolescence. PF occurred rarely after the age of 13 years. The age at fracture correlated with the fracture site with 85% of the fractures occurring in the femur in the first five years of life and an increased frequency of tibia and foot fractures later in life. While, overall high lesion levels and preceding immobilizing events were risk factors for PF, femur fractures in children under 6 years-of-age occurred independent of their lesion level, and the age at verticalization did not correlate with PF rates.Conclusion: Based on these findings, standardized and effective preventive physiotherapeutic and/or pharmacological interventions to tackle PF in spina bifida need to consider age-specific differences in occurrence and reoccurrence of fractures.What is Known:• Pathological fractures are common in patients with spina bifida aperta, and associated risk factors include high lesion level, immobilization and low bone density.What is New:• We first report a bimodal frequency distribution of pathological fractures in childhood (first peak 1-5 years, second peak 10-12 years) and link early-onset fracture occurrence with the risk of multiple fractures arise in a short time period but a the chance of self-limitation of fracture series within a few years.• We show that femur fractures in children under 6 years-of-age occurred independent of their lesion level, and the age at verticalization did not correlate with PF rates.• We further link the age-dependent occurrence pattern with the risk of further fractures and with the chance of self-limitation of fracture series. The earlier a first fracture occurs, the more probable multiple fractures arise in a short time period. Nevertheless, early fracture series are often self-limiting within a few years.• Femur fractures in children under 6 years-of-age occurred independent of their lesion level, and the age at verticalization did not correlate with PF rates.• Based on these findings, physiotherapeutic and/or pharmaceutical concepts need to be developed in an age-adapted manner and in consideration of the potential self-limiting nature of fracture series.

Tissue expression distribution characterization of the host defense peptide dCATH in Anas platyrhynchos

Cathelicidin host defense peptides (cHDPs) widely exist in animals with the functions of innate immunity and acquired immunity. To investigate the tissue and sequential expression patterns of the dCATH gene, which encodes the only cHDPs found in waterfowls, we analyzed the internal organs of healthy ducks (Shaxoxing Sheldrake) from 1-day-old to 28-day-old raised in the natural environment. The dCATH mRNA expression level across tissues was determined via quantitative real-time polymerase chain reaction (qRT-PCR). Monoclonal antibody against the mature dCATH peptide used in enzyme-linked immunosorbent assay (ELISA) was prepared by the lymphocyte hybridoma technique for the first time. The concentration of the dCATH peptide in tissues was determined by ELISA. It showed that the dCATH mRNA had a clear tissue-specificity and age-dependent expression pattern, and it was highly expressed in the bone marrow and moderately expressed in the liver, kidney, spleen, pancreas and bursa of healthy duck. The peptide levels of dCATH in liver, kidney, spleen, pancreas and bursa changed with the age of duck, and the peptide concentration in these organs was between 88 and 128 ng/g tissue. For the first time, we characterized the concentration of the cHDP dCATH in vivo. Our study may represent new insights into the crosstalk of innate immunity, tissue development and age.

Joint estimation of growth and survival from mark-recapture data to improve estimates of senescence in wild populations.

Understanding age-dependent patterns of survival is fundamental to predicting population dynamics, understanding selective pressures, and estimating rates of senescence. However, quantifying age-specific survival in wild populations poses significant logistical and statistical challenges. Recent work has helped to alleviate these constraints by demonstrating that age-specific survival can be estimated using mark-recapture data even when age is unknown for all or some individuals. However, previous approaches do not incorporate auxiliary information that can improve age estimates of individuals. We introduce a survival estimator that combines a von Bertalanffy growth model, age-specific hazard functions, and a Cormack-Jolly-Seber mark-recapture model into a single hierarchical framework. This approach allows us to obtain information about age and its uncertainty based on size and growth for individuals of unknown age when estimating age-specific survival. Using both simulated and real-world data for two painted turtle (Chrysemys picta) populations, we demonstrate that this additional information substantially reduces the bias of age-specific hazard rates, which allows for the testing of hypotheses related to aging. Estimating patterns of senescence is just one practical application of jointly estimating survival and growth; other applications include obtaining better estimates of the timing of recruitment and improved understanding of life-history trade-offs between growth and survival.

Age-related patterns of yolk androgen deposition are consistent with adaptive brood reduction in spotless starlings

Female birds can influence offspring development by adjusting egg size or by a differential allocation of egg resources. Such maternal effects can be expected to be shaped by natural selection, given the costs connected to the allocation of maternal resources. Among egg components, yolk androgens play an important role in affecting offspring life-history traits. Despite their relevance for nestling development, factors accounting for the observed within- and between-clutch variation are still poorly known. By using a cross-sectional sampling approach, we tested the effect of female age, laying order and laying date on the deposition of yolk androstenedione (A4) and testosterone (T), since young and older females could maximize their fitness differently according to breeding conditions. We found a remarkable lack of differences in overall yolk androgen levels across different ages. However, comparing first-year with older females, our results showed that age did not influence yolk T levels at the beginning of the breeding season, whereas at the end, first-year females transferred lower hormone levels than older females. Within clutches, both androgens increased across the laying sequence, suggesting that late nestlings benefit from an increased allocation that could compensate hatching asynchrony. However, when considering A4, we found that, whereas older females always increased A4 levels across the laying sequence, first-year females did not increase it at the end of the breeding season, thus increasing the likelihood of brood reduction when environmental conditions became hardest. These findings suggest that yolk A4 variation may be particularly important at the within-clutch scale, by providing females with a tool to modify nestling hierarchies. The study of maternal effects shows that avian mothers can adjust offspring development to environmental conditions by altering egg composition. The effects of maternal age on such egg allocation process depend on the balance of benefits and costs that affects each age class. We examine if young and older mothers differ in terms of yolk androgen deposition and egg quality, since age may influence offspring fitness, and could represent a costly maternal investment. We found an absence of overall age-dependent patterns in yolk androgen deposition, except when we considered laying order and laying date. In late clutches, when breeding conditions are harsher, 1-year-old females carried out a lower deposition of both resources (yolk mass) and modifiers (androgens) than older mothers did. We suggest that such a pattern would reinforce the effects of hatching asynchrony, favouring brood reduction at the end of the breeding season by first-year females.

Life history and age-dependent mortality processes in tropical reptiles

AbstractActuarial senescence appears to be a common process, and senescence patterns are highly variable across the tree of life. To date, studies on animal senescence have largely focused on model species, such as as fruit flies, humans and a few other endotherms. In contrast, our knowledge about ageing remains fragmentary in ectotherm vertebrates, such as reptiles. Here, we examined life history and age-dependent mortality patterns in three tropical tortoises (Kinixys erosa, Kinixys homeana and Kinixys nogueyi) and snakes (Bitis gabonica, Bitis nasicornis and Causus maculatus). Our study revealed that tortoises of the genus Kinixys had a higher survival and a lower recruitment than snakes of the genera Bitis and Causus, indicating a slower life history. Furthermore, we confirmed that survival decreased more slowly with age in tortoises than in snakes. In addition, we highlighted contrasting patterns of age-dependent mortality among the three genera. In Kinixys, the relationship between mortality rate and age was positive and linear, suggesting gradual senescence over tortoise lifetime. In contrast, the relationship between mortality rate and age was negative and sharp in Bitis and Causus, possibly owing to a ‘negative senescence’. Our study is one of the few to have examined and compared the demography and age-dependent mortality patterns of tropical reptiles. Among other things, our results suggest that although negative senescence has never been reported in endotherm vertebrates, it could be a common phenomenon in ectotherms.

Dynamic expressions of hypothalamic genes regulate seasonal breeding in a natural rodent population.

Seasonal breeding is a universal reproductive strategy in many animals. Hypothalamic genes, especially type 2 and 3 iodothyronine deiodinases (Dio2/3), RFamide-related peptide 3 (Rfrp-3), kisspeptin (Kiss-1) and gonadotropin-releasing hormone (GnRH), are involved in a photoperiodic pathway that encodes seasonal signals from day length in many vertebrate species. However, the seasonal expression patterns of these genes in wild mammals are less studied. Here, we present a four-year field investigation to reveal seasonal rhythm and age-dependent reproductive activity in male Brandt's voles (Lasiopodomys brandtii) and to detect relationships among seasonal expression profiles of hypothalamic genes, testicular activity, age and annual day length. From breeding season (April) to nonbreeding season (October), adult male voles displayed a synchronous peak in gonadal activity with annual day length around summer solstice, which was jointly caused by age structure shifts and age-dependent gonadal development patterns. Overwintered males maintained reproductive activity until late in the breeding season, whereas most newborn males terminated gonadal development completely, except for a minority of males born early in spring. Consistently, the synchronous and opposite expression profiles of Dio2/3 suggest their central function to decode photoperiodic signals and to predict the onset of the nonbreeding season. Moreover, changes in Dio2/3 signals may guide the actions of Kiss-1 and Rfrp-3 to regulate the age-dependent divergence of reproductive strategy in wild Brandt's vole. Our results provide evidence on how hypothalamic photoperiod genes regulate seasonal breeding in a natural rodent population.

Age-dependent dysregulation of redox genes may contribute to fibrotic pulmonary disease susceptibility

Aging is associated with enhanced oxidative stress and increased susceptibility to numerous diseases. This relationship is particularly striking with respect to the incidence of fibrotic lung disease. To identify potential mechanisms underlying the association between aging and susceptibility to fibrotic lung disease we analyzed transcriptome data from 342 disease-free human lung samples as a function of donor age. Our analysis reveals that aging in lung is accompanied by modest yet progressive changes in genes modulating redox homeostasis, the TGF-beta 1 signaling axis, and the extracellular matrix (ECM), pointing to an aging lung functional network (ALFN). Further, the transcriptional changes we document are tissue-specific, with age-dependent gene expression patterns differing across organ systems. Our findings suggest that the age-associated increased incidence of fibrotic pulmonary disease occurs in the context of tissue-specific, age-dependent transcriptional changes. Understanding the relationship between age-associated gene expression and susceptibility to fibrotic pulmonary disease may allow for more accurate risk stratification and effective therapeutic interventions within this challenging clinical space.

Age-dependent variability in spatiotemporal gait parameters and the walk-to-run transition

Adolescents tend to exhibit more variability in their gait patterns than adults, suggesting a lack of gait maturity during this period of ongoing musculoskeletal growth and development. However, there is a lack of consensus over the age at which mature gait patterns are achieved and the factors contributing to gait maturation. Therefore, the purpose of this study was to investigate gait control and maturity in adolescents by determining if differences existed between adolescents and adults in a) the amount of spatiotemporal variability of walking and running patterns across a range of speeds, and b) how swiftly gait patterns are adapted to increasing gait speed during the walk-to-run transition. Forty-six adolescents (10–12-year-olds, n = 17; 13–14-year-olds, n = 12; and 15–17-year-olds, n = 17) and 12 young adults completed an incrementally ramped treadmill test (+0.2 km·h−1 every 30 s) to determine the preferred transition speed (PTS) during a walk-to-run transition. Age-related differences in the variability of stride lengths and stride durations were assessed across 4 speeds (self-selected walking speed, PTS − 0.06 m·s−1, PTS + 0.06 m·s−1, PTS + 0.83 m·s−1). Repeated measures ANOVAs (p < 0.05) compared coefficients of variation for these spatiotemporal parameters, while a one-way ANOVA compared the numbers of gait transitions and speed increments used to identify PTS between the adolescent groups and young adults. Compared to adults, 10–12yo exhibited more spatiotemporal variability during all gait conditions, while 13–17yo only exhibited more variability at PTS + 0.06 m·s−1. No age-dependent pattern was observed in PTS values, but 10–12yo completed more gait transitions over more speed increments than 15–17yo and adults. The development of mature gait patterns is thus a progressive process, with walking maturing at an earlier age than running. As 10-12yo were unable to swiftly adapt gait patterns to the changing task demands, their control mechanisms of gait may not have fully matured yet.

Shall we treat patients with benign epileptiform discharges of childhood without epileptic seizures?

Benign epileptiform discharges of childhood are age-dependent electroencephalogram patterns associated with idiopathic benign focal epilepsy. Multiple studies have demonstrated that focal epileptiform discharges can be registered in patients without any clinical manifestations of epilepsy. Long-term follow-up of clinically healthy children with benign epileptiform discharges of childhood on electroencephalogram demonstrated that 14 % of them developed epileptic seizures with age and 50 % developed various cognitive and behavioral disorders. The question of whether or not to treat such patients (with benign epileptiform discharges of childhood on electroencephalogram but without epileptic seizure) is still being widely discussed. Individual decision making with the consideration of potential risks and benefits for a patient is preferable in this case. Valproic acid is the drug of first choice in these patients.

Male age: negative impact on sperm DNA fragmentation.

The main goal of semen processing in Assisted Reproductive Techniques (ART) is to select sperm with good viability and, at the same time, remove Reactive Oxygen Species (ROS) sources (such as leukocytes) and reduce the percentage of morphologically abnormal sperm for fertility treatment. We performed a comparative analysis on sperm DNA fragmentation after Density Gradient Centrifugation (DGC) using products sold by two competing companies. Our results showed comparable DNA Fragmentation Index (DFI) after treatment with both DGC products. However, in both cases, a comparable number of samples do not benefit from the treatment. Interestingly, increasing evidences indicated that male age has a negative impact on sperm DNA fragmentation, but the mechanisms underlying age-dependent patterns of sperm decline have not yet been fully understood. Thus, we performed a comparative analysis of DFI before and after treatment with DGC products in age-stratified sample populations. Our results showed a worsening of the baseline DFI in the eldest group and the benefits of DGC on sperm DNA were compromised. In conclusion, our work consolidates the current evidences suggesting that both paternal and maternal aging, critically affects reproductive success.

Feedback Enhances Preschoolers' Performance in an Inhibitory Control Task.

Accomplishing inhibition tasks requires not only inhibitory skills but also goal maintenance. The present study aimed to disentangle goal maintenance from inhibition. Therefore, we experimentally manipulated goal-maintenance demands by means of feedback. Three-year-old (n = 84) and 4-year-old (n = 75) preschoolers were randomly assigned to one of four experimental conditions. Results revealed an age-dependent pattern: three-year-olds that were assigned to one of the conditions with feedback outperformed those assigned to the control condition without feedback. It seems that especially performance-related feedback reduced goal-maintenance demands in 3-year-olds, resulting in enhanced inhibitory performance. Four-year-olds, in contrast, showed high performance across all conditions. Age-differences between the 3- and 4-year-olds were only significant for the control condition. Thus, with feedback, performance of the 3-year-olds was similar to that of the 4-year-olds. The present results seem to indicate that in an inhibition task, 3-year-olds’ struggle not only with inhibiting a prepotent response but also with adhering to the task goal.