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Gait adaptability training programs to prevent falls in healthy older adults can be proposed in virtual reality. The development of training programs requires the characterization of the target population. Before proposing an innovative training program to develop gait adaptability behavior of healthy older adults in fully immersive virtual reality, we had to compare gait adaptability behavior between healthy older adults and young adults in virtual reality. Twenty healthy older adults (with no fall history) and twenty young adults performed a goal-directed locomotion task in a totally secure virtual reality set-up. Gait adaptability behavior was investigated via a set of measures taking into account gait speed, pointing accuracy, and the evolution of the relationship between the participant and the environment through both inter-trial and trial-by-trial analyses. Mann-Whitney tests and linear regressions were performed to determine potential age differences. The results reveal some common and specific strategies in gait adaptability behavior between healthy older and young adults. In both populations, successive gait adjustments depend on the state of the agent-environment system. However, older adults walked more slowly than young adults (p <.001) with a greater coupling at the end of the target approach (p =.003). In the context of fall prevention in healthy older adults, fully immersive VR appears as a relevant tool to propose relevant gait training programs to improve gait adjustments. • Older adults initiated their gait adjustments earlier in comparison to young adults. • Gait adaptability behavior depends on the current state of the agent-environment system. • Virtual reality appears as a relevant tool to propose relevant training programs in older adults. [ABSTRACT FROM AUTHOR]

In many primates, the acoustic properties of alarm calls can provide information on the level of perceived predatory threat as well as influence the antipredator behavior of nearby conspecifics. The present study examined the harmonics-to-noise ratio (tonality of spectral structure) of alarm calls emitted by white-faced capuchin monkeys (Cebus capucinus) in trees directed at photographic models of a boa constrictor, neotropical rattlesnake, scorpion eater snake, and white snake-shaped control presented on the ground. The average and peak harmonics-to-noise ratios of initial alarm calls by infants, juveniles, and adults and those of nearby second callers were analyzed using PRAAT software. Averaged for age class, the peak harmonics-to-noise ratio of alarm calls directed at the boa constrictor model, characterizing a primary capuchin predator, was reliably higher than the peak harmonics-to-noise ratio of alarm calls directed at the harmless scorpion eater model. This effect was influenced by the higher harmonics-to-noise ratio of infant alarm calls and it disconfirmed our prediction, based on primate vocalization research, that snake perception would increase arousal and alarm-call noisiness. Levels of call tonality did not distinguish the boa and rattlesnake or rattlesnake and scorpion eater models for any age class. Higher alarm-call tonality appeared contagious to nearby perceivers, with focal alarm calling influencing the level of tonality of the first calls of second callers. Together, these findings suggest that the higher peak harmonics-to-noise ratio of capuchin alarm calling directed at snakes is contagious and possibly conveys information about the level of perceived predatory threat.

The diet of an individual animal is subject to change over time, both in response to short‐term food fluctuations and over longer time scales as an individual ages and meets different challenges over its life cycle. A metabarcoding approach was used to elucidate the diet of different life stages of a migratory songbird, the Eurasian reed warbler (Acrocephalus scirpaceus) over the 2017 summer breeding season in Somerset, the United Kingdom. The feces of adult, juvenile, and nestling warblers were screened for invertebrate DNA, enabling the identification of prey species. Dietary analysis was coupled with monitoring of Diptera in the field using yellow sticky traps. Seasonal changes in warbler diet were subtle, whereas age class had a greater influence on overall diet composition. Age classes showed high dietary overlap, but significant dietary differences were mediated through the selection of prey; (i) from different taxonomic groups, (ii) with different habitat origins (aquatic vs. terrestrial), and (iii) of different average approximate sizes. Our results highlight the value of metabarcoding data for enhancing ecological studies of insectivores in dynamic environments. [ABSTRACT FROM AUTHOR]

Abstract The diet of an individual animal is subject to change over time, both in response to short‐term food fluctuations and over longer time scales as an individual ages and meets different challenges over its life cycle. A metabarcoding approach was used to elucidate the diet of different life stages of a migratory songbird, the Eurasian reed warbler (Acrocephalus scirpaceus) over the 2017 summer breeding season in Somerset, the United Kingdom. The feces of adult, juvenile, and nestling warblers were screened for invertebrate DNA, enabling the identification of prey species. Dietary analysis was coupled with monitoring of Diptera in the field using yellow sticky traps. Seasonal changes in warbler diet were subtle, whereas age class had a greater influence on overall diet composition. Age classes showed high dietary overlap, but significant dietary differences were mediated through the selection of prey; (i) from different taxonomic groups, (ii) with different habitat origins (aquatic vs. terrestrial), and (iii) of different average approximate sizes. Our results highlight the value of metabarcoding data for enhancing ecological studies of insectivores in dynamic environments.

This paper focuses on the analysis of Bebras Challenge tasks to find Informatics tasks that develop abstract thinking. Our study seeks to find which Bebras tasks develop abstraction and in what way. We analysed hundreds of tasks from the Czech contest to identify those tasks requiring participants to abstract directly or use abstract structures. Results show that an agreement among experts on stating which task is focused on abstraction is at a moderate level. We discovered that tasks focused on abstraction occur four to five times less frequently in sets of contest tasks than algorithmic tasks. Our findings proved that abstract tasks results compared with algorithmic ones did not differ in neither age nor gender group of contestants. [ABSTRACT FROM AUTHOR]

In many countries where tuberculosis (TB) is endemic, the Bacillus Calmette–Guérin (BCG) vaccine is given as close to birth as possible to protect infants and children from severe forms of TB. However, BCG has variable efficacy and is not as effective against adult pulmonary TB. At present, most animal models used to study novel TB vaccine candidates rely on the use of adult animals. Human studies show that the infant immune system is different to that of an adult. Understanding how the phenotypic profile and functional ability of the immature host immune system compares to that of a mature adult, together with the subsequent BCG immune response, is critical to ensuring that new TB vaccines are tested in the most appropriate models. BCG-specific immune responses were detected in macaques vaccinated within a week of birth from six weeks after immunization indicating that neonatal macaques are able to generate a functional cellular response to the vaccine. However, the responses measured were significantly lower than those typically observed following BCG vaccination in adult rhesus macaques and infant profiles were skewed towards the activation and attraction of macrophages and monocytes and the synthesis in addition to release of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-α. The frequency of specific immune cell populations changed significantly through the first three years of life as the infants developed into young adult macaques. Notably, the CD4:CD8 ratio significantly declined as the macaques aged due to a significant decrease in the proportion of CD4+ T-cells relative to a significant increase in CD8+ T-cells. Also, the frequency of both CD4+ and CD8+ T-cells expressing the memory marker CD95, and memory subset populations including effector memory, central memory and stem cell memory, increased significantly as animals matured. Infant macaques, vaccinated with BCG within a week of birth, possessed a significantly higher frequency of CD14+ classical monocytes and granulocytes which remained different throughout the first three years of life compared to unvaccinated age matched animals. These findings, along with the increase in monokines following vaccination in infants, may provide an insight into the mechanism by which vaccination with BCG is able to provide non-specific immunity against non-mycobacterial organisms. [ABSTRACT FROM AUTHOR]

Studies examining the effect of embodied cognition have shown that linking one's body movements to a cognitive task can enhance performance. The current study investigated whether concurrent walking while encoding or recalling spatial information improves working memory performance, and whether 10-year-old children, young adults, or older adults (M age = 72 years) are affected differently by embodiment. The goal of the Spatial Memory Task was to encode and recall sequences of increasing length by reproducing positions of target fields in the correct order. The nine targets were positioned in a random configuration on a large square carpet (2.5 m × 2.5 m). During encoding and recall, participants either did not move, or they walked into the target fields. In a within-subjects design, all possible combinations of encoding and recall conditions were tested in counterbalanced order. Contrary to our predictions, moving particularly impaired encoding, but also recall. These negative effects were present in all age groups, but older adults' memory was hampered even more strongly by walking during encoding and recall. Our results indicate that embodiment may not help people to memorize spatial information, but can create a dual-task situation instead. [ABSTRACT FROM AUTHOR]

In many countries where tuberculosis (TB) is endemic, the Bacillus Calmette–Guérin (BCG) vaccine is given as close to birth as possible to protect infants and children from severe forms of TB. However, BCG has variable efficacy and is not as effective against adult pulmonary TB. At present, most animal models used to study novel TB vaccine candidates rely on the use of adult animals. Human studies show that the infant immune system is different to that of an adult. Understanding how the phenotypic profile and functional ability of the immature host immune system compares to that of a mature adult, together with the subsequent BCG immune response, is critical to ensuring that new TB vaccines are tested in the most appropriate models. BCG-specific immune responses were detected in macaques vaccinated within a week of birth from six weeks after immunization indicating that neonatal macaques are able to generate a functional cellular response to the vaccine. However, the responses measured were significantly lower than those typically observed following BCG vaccination in adult rhesus macaques and infant profiles were skewed towards the activation and attraction of macrophages and monocytes and the synthesis in addition to release of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-α. The frequency of specific immune cell populations changed significantly through the first three years of life as the infants developed into young adult macaques. Notably, the CD4:CD8 ratio significantly declined as the macaques aged due to a significant decrease in the proportion of CD4+ T-cells relative to a significant increase in CD8+ T-cells. Also, the frequency of both CD4+ and CD8+ T-cells expressing the memory marker CD95, and memory subset populations including effector memory, central memory and stem cell memory, increased significantly as animals matured. Infant macaques, vaccinated with BCG within a week of birth, possessed a significantly higher frequency of CD14+ classical monocytes and granulocytes which remained different throughout the first three years of life compared to unvaccinated age matched animals. These findings, along with the increase in monokines following vaccination in infants, may provide an insight into the mechanism by which vaccination with BCG is able to provide non-specific immunity against non-mycobacterial organisms.

Studies examining the effect of embodied cognition have shown that linking one’s body movements to a cognitive task can enhance performance. The current study investigated whether concurrent walking while encoding or recalling spatial information improves working memory performance, and whether 10-year-old children, young adults, or older adults (Mage = 72 years) are affected differently by embodiment. The goal of the Spatial Memory Task was to encode and recall sequences of increasing length by reproducing positions of target fields in the correct order. The nine targets were positioned in a random configuration on a large square carpet (2.5 m × 2.5 m). During encoding and recall, participants either did not move, or they walked into the target fields. In a within-subjects design, all possible combinations of encoding and recall conditions were tested in counterbalanced order. Contrary to our predictions, moving particularly impaired encoding, but also recall. These negative effects were present in all age groups, but older adults’ memory was hampered even more strongly by walking during encoding and recall. Our results indicate that embodiment may not help people to memorize spatial information, but can create a dual-task situation instead.

We investigated the effects of aging on attentional functions using the Attention Network Test (ANT), which enables simultaneous testing of alerting, orienting, and executive networks, and their interactions. Participants were 38 young adults (M age = 21.35 years) and 36 older adults (M age = 71.17 years). Although the older adults exhibited a slower overall response, the three attentional functions showed different modulation according to age group and the trial block being completed. Older adults exhibited significant impairment in the alerting function, regardless of whether they were completing the first or second block of trials, whereas their executive function decreased significantly only in Block 2 owing to cognitive fatigue. Both age groups performed similarly for the orienting function. Future researchers should seek to further clarify the specificity of attention function with people aged over 70 years to address their attention disturbance. [ABSTRACT FROM AUTHOR]

The present research investigated locus of control, sex and age to identify which influenced crime perceptions and to what extent. A 2 (internal versus external locus of control) x 2 (male versus female) x 3 (young, middle and older adult) between groups' design was used. Sixty participants completed Rotter's (1966) Locus of Control Questionnaire and a perceptions of crime questionnaire. A 3x2x2 MANOVA was conducted. Only one main effect of sex was present, with males reporting themselves to be less likely to report suspicious behaviour than females. No other main effects were present across the remaining eight crime perception questions. Only one significant interaction existed, which suggested that older males and younger females were in favour of increased punishment for petty crimes. When investigating petty crime perceptions, locus of control is a less important consideration than sex and age differences. [ABSTRACT FROM AUTHOR]

Outline: Lung ultrasound can detect B‐lines in both disease states and normal patients. B‐lines are sensitive indicators for interstitial oedema, but research is limited in terms of what is a 'normal' amount in healthy adults. Current belief is that 3 B‐lines in laterobasal areas can be normal. We aimed to determine what is normal in healthy patients of different ages. We hypothesised that older patients and patients with the previous history of lung disease or smoking would have more B‐lines. Methods: We performed a cross‐sectional study on a convenience sample of 200 volunteers: 100 aged 18–49 (median age 33.5) and 100 aged 50–91 (median age 70.5). Volunteers were recruited in 2017 from two participating sites. All participants were scanned by a single researcher using a standardised lung protocol. Multivariate regression was conducted to determine independent predictors of B‐line presence. Results: B‐lines were found in 12.5% (95%CI: 8.4–17.6) of all volunteers (n = 25/200), with 20% (95%CI: 13.3–28.9) prevalence in the younger group and 5% (95%CI: 1.9–10.7) in the older group (P < 0.0001). A total of 84% (95%CI: 65.3–93.6) had only 1 B‐line (n = 21/25). 31.3% (95%CI: 20.0–45.6) of young females had B‐lines. Only one volunteer had ≥3 B‐lines in one scanned area. Participants with chronic lung disease had more B‐lines (P = 0.03). Smokers (n = 13) also had more B‐lines (31% vs. 11% of non‐smokers). Smoking and younger age were independent predictors of B‐line presence multivariate logistic regression models, but only for females. Conclusion: ≥2 B‐lines are uncommon in healthy, ambulatory adults. Further research is needed to investigate the higher prevalence found in young females. [ABSTRACT FROM AUTHOR]

Background: The prevalence of anterior cruciate ligament (ACL) injuries increases during maturation and peaks during late adolescence. Previous studies suggested an age-related association between participation in injury prevention programs and reduction of ACL injury. However, few studies have investigated differences in biomechanical changes after injury prevention programs between preadolescent and adolescent athletes. Purpose/Hypothesis: The purpose was to investigate the influence of age on the effects of the FIFA Medical and Research Centre (F-MARC) 11+ injury prevention warm-up program on differences in biomechanical risk factors for ACL injury between preadolescent and adolescent female soccer players. It was hypothesized that the ACL injury risk factors of knee valgus angle and moment would be greater at baseline but would improve more after training for preadolescent athletes than adolescent athletes. It was further hypothesized that flexor-extensor muscle co-contraction would increase after training for both preadolescent and adolescent athletes. Study Design: Controlled laboratory study. Methods: Institutional Review Board–approved written consent was obtained for 51 preadolescent female athletes aged 10 to 12 years (intervention: n = 28, 11.8 ± 0.8 years; control: n = 23, 11.2 ± 0.6 years) and 43 adolescent female athletes aged 14 to 18 years (intervention: n = 22, 15.9 ± 0.9 years; control: n = 21, 15.7 ± 1.1 years). The intervention groups participated in 15 in-season sessions of the F-MARC 11+ program 2 times per week. Pre- and postseason motion capture data were collected during 4 tasks: preplanned cutting, unanticipated cutting, double-legged jump, and single-legged jump. Lower extremity joint angles and moments were estimated through biomechanical modeling. Knee flexor-extensor muscle co-contraction was estimated from surface electromyography. Results: At baseline, preadolescent athletes displayed greater initial contact and peak knee valgus angles during all activities when compared with the adolescent athletes, but knee valgus moment was not significantly different between age groups. After intervention training, preadolescent athletes improved and decreased their initial contact knee valgus angle (–1.24° ± 0.36°; P = .036) as well as their peak knee valgus moment (–0.57 ± 0.27 percentage body weight × height; P = .033) during the double-legged jump task, as compared with adolescent athletes in the intervention. Compared with adolescent athletes, preadolescent athletes displayed higher weight acceptance flexor-extensor muscle co-contraction at baseline during all activities (P < .05). After intervention training, preadolescent athletes displayed an increase in precontact flexor-extensor muscle co-contraction during preplanned cutting as compared with adolescent intervention athletes (0.07 ± 0.02 vs –0.30 ± 0.27, respectively; P = .002). Conclusion: The F-MARC 11+ program may be more effective at improving some risk factors for ACL injury among preadolescent female athletes than adolescent athletes, notably by reducing knee valgus angle and moment during a double-legged jump landing. Clinical Relevance: ACL prevention programs may be more effective if administered early in an athlete’s career, as younger athletes may be more likely to adapt new biomechanical movement patterns. [ABSTRACT FROM AUTHOR]

Defensible use of self-reported cannabis use problem scales in age comparative frameworks requires that measured constructs have equal psychometric properties across age groups. This study compares the psychometric properties of the Cannabis Abuse Screening Test (CAST) across three age groups (18-24, 25-29, 30-40). Data was collected online from an accessible sample of 1316 cannabis users. Factor analysis compared the optimal factor structure and dimensionality diffraction. Multi-group Model Invariance tests examined measurement invariance across the three age groups. CAST was two-dimensional in all age groups with one factor measuring cannabis use problems and the other measuring deviation from a common standard of use. The two-dimensional structure was more pronounced in older age groups. Weak factorial invariance was supported, suggesting that the meaning of the CAST factors is equivalent across age groups. Partial, but not full, strong factorial invariance was supported, indicating that only the cannabis use problem factor can be defensibly used to measure age group mean differences. Results confirm a well-defined two-dimensional CAST structure and factorial invariance across age groups. However, caution is needed when using the two items measuring deviation from a common standard in an age-comparative framework. Replication studies based on a representative sample are needed. [ABSTRACT FROM AUTHOR]

Three methods of age estimation were compared for Dentex dentex. Based on sectioned otoliths, scales appeared to be relevant only up to 5 years and whole otoliths up to 12 years. The maximum estimated age was 36 years, which constitutes to date the oldest age reported. [ABSTRACT FROM AUTHOR]

Abstract: The Rb–Sr decay system is one of the most widely used geochronometers for obtaining ages and cooling rates of terrestrial magmatic, metamorphic, and hydrothermal events. It has also been extensively applied to date extraterrestrial, early solar system events. The accuracy of Rb–Sr ages, however, strongly depends on the accuracy of the 87Rb decay constant (λ87Rb). We determined λ87Rb relative to the decay constants of 235U and 238U by comparing Rb–Sr ages of minerals with U–Pb ages obtained from the same intrusion. Comparison of U–Pb emplacement ages with high-precision Rb–Sr mineral ages from three rapidly cooled igneous rocks covering an age range of ca. 2.5Ga yields an unweighted mean λ87Rb of 1.393±0.004×10−11 yr−1 (i.e., ±0.3%), corresponding to a half-life of 49.76×109 years. Because this decay constant is 2% lower than the presently recommended one, many previously published ages are 2% too young and the resulting geologic interpretations may need revision. [Copyright &y& Elsevier]

In many primates, the acoustic properties of alarm calls can provide information on the level of perceived predatory threat as well as influence the antipredator behavior of nearby conspecifics. The present study examined the harmonics‐to‐noise ratio (tonality of spectral structure) of alarm calls emitted by white‐faced capuchin monkeys (Cebus capucinus) in trees directed at photographic models of a boa constrictor, neotropical rattlesnake, scorpion eater snake, and white snake‐shaped control presented on the ground. The average and peak harmonics‐to‐noise ratios of initial alarm calls by infants, juveniles, and adults and those of nearby second callers were analyzed using PRAAT software. Averaged for age class, the peak harmonics‐to‐noise ratio of alarm calls directed at the boa constrictor model, characterizing a primary capuchin predator, was reliably higher than the peak harmonics‐to‐noise ratio of alarm calls directed at the harmless scorpion eater model. This effect was influenced by the higher harmonics‐to‐noise ratio of infant alarm calls and it disconfirmed our prediction, based on primate vocalization research, that snake perception would increase arousal and alarm‐call noisiness. Levels of call tonality did not distinguish the boa and rattlesnake or rattlesnake and scorpion eater models for any age class. Higher alarm‐call tonality appeared contagious to nearby perceivers, with focal alarm calling influencing the level of tonality of the first calls of second callers. Together, these findings suggest that the higher peak harmonics‐to‐noise ratio of capuchin alarm calling directed at snakes is contagious and possibly conveys information about the level of perceived predatory threat. Recognizable white‐faced capuchin monkeys (Cebus capucinus) in Costa Rica traveling in trees were presented different snake models on the ground while their alarm calls were recorded. The most dangerous snake represented by a model boa constrictor elicited the highest peak alarm‐call tonality in spectral structure, especially that of infant capuchins, compared with a scorpion eater model representing a harmless snake. The peak tonality of focal alarm calls had socially contagious properties by influencing the alarm‐call tonality of nearby capuchins. Young white‐faced capuchin in Costa Rica alarm calling at a model boa constrictor [ABSTRACT FROM AUTHOR]

Acute subdural hematoma is a serious complication following traumatic brain injury. Large volume hematomas or those with underlying brain injury can cause mass effect, midline shift, and eventually herniation of the brain. Acute subdural hematomas in the young are associated with high-energy trauma and often have underlying contusions, while acute subdural hematomas in the elderly are associated with minor trauma and an absence of underlying contusions, even though the elderly are more likely to be on anticoagulants or anti-platelet therapy. In the young patients with high impact injuries the hematomas tend to be small and the underlying brain injury and swelling is responsible for the increased intracranial pressure and midline shift. In the elderly, the injuries are low impact (e.g fall from standing), the underlying brain is intact, and the volume of the hematoma itself produces symptoms. In addition the use of anticoagulants and antiplatelet agents in the elderly population has been thought to be a poor prognostic indicator and is considered to be responsible for larger hematomas and poor outcome. When managed conservatively, acute subdural hematomas can sometimes progress to chronic subdural hematoma formation, further enlargement, seizures, and progressive midline shift. Another potential difference in the young and the elderly is brain atrophy, which increases the potential space to accommodate a larger hematoma. It is not known if these two groups differ in other ways that might have implications for treatment or prognosis. In this paper, we investigate the clinical course of 80 patients admitted to our institution with acute subdural hematomas, to identify differences in patients above or below the age of 65 years. The natural progression/resolution of acute subdural hematomas was mapped by measuring volume expansion/regression over time. In this retrospective chart review, we investigated clinical baseline metrics and subsequent volumetric expansion outcomes between patients < 65 years old (N=44) and those > 65 years old (N=36). Volume was estimated by the ABC/2 method. We observed a statistically significant difference between groups in use of anticoagulants χ 2 =40.305 with p < 0.001, corrective platelet administration χ 2 =19.380 with p < 0.001, gender χ 2 =14.573 with p < 0.001, and Glasgow Coma Scale with χ 2 =23.125 (p=0.026). Overall outcomes were similar in the two groups. Younger patients on average had worse presenting GCS scores, but recovered comparable to older patients. No significant difference in rate of volume expansion, resolution time, or need for surgical treatment was seen between these two groups. We conclude that the initial volume, size, and severity of subdural hematoma determined by the Glasgow Coma Scale score is more likely to predict surgery or future expansion than age of the patient. Patients on oral anti-coagulants that are given appropriate medical reversal agents early do quite well and no impact on the eventual outcome could be demonstrated. Further work is needed to establish better predictors of future volume expansion, and progression to chronic subdural hematoma based on improved severity scales., Competing Interests: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.