Age-related change in the relationship between circadian period, circadian phase, and diurnal preference in humans

2002 ◽  
Vol 318 (3) ◽  
pp. 117-120 ◽  
Author(s):  
Jeanne F. Duffy ◽  
Charles A. Czeisler
Keyword(s):  
Circadian Period ◽  
Circadian Phase ◽  
Age Related ◽  
Diurnal Preference ◽  
The Relationship

Circadian sleep-wake cycle organization in squirrel monkeys

1985 ◽  
Vol 248 (3) ◽  
pp. R353-R362 ◽  
Author(s):  
D. B. Wexler ◽  
M. C. Moore-Ede
Keyword(s):  
Sleep Onset ◽  
Nrem Sleep ◽  
Squirrel Monkeys ◽  
Circadian Cycle ◽  
Circadian Period ◽  
Constant Illumination ◽  
Circadian Phase ◽  
Internal Phase ◽  
The Difference ◽  
The Relationship

To investigate the relationship between circadian rhythms of body temperature and sleep-wake stages, four squirrel monkeys were prepared for unrestrained monitoring of temperature, locomotor activity, electroencephalogram, electroculogram, and electromyogram. Continuous records for each animal were made for several 12-h light-dark (LD) cycles and then after a few days in constant illumination (LL). All animals maintained consolidated sleep-wake cycles and had a longer circadian period (mean 24.7 h) in LL than in LD (mean 24.1 h). The increased period reflected greater time per circadian cycle spent awake in LL (mean 14.0 h) than in LD (mean 12.8 h). Total night NREM sleep was less in LL (mean 6.5 h) than in LD (mean 8.2 h). Sleep onset occurred at later phases in LL (187 +/- 6 degrees) than in LD (170 +/- 2 degrees). Because the circadian phase measure of NREM sleep was unchanged between LD and LL conditions, the difference in sleep onsets reflected balanced changes in NREM circadian waveforms. Wake-up phases were the same in both conditions (mean 342 degrees). In summary, during free run squirrel monkeys maintain a stable consolidated circadian sleep-wake cycle with a period greater than 24 h, but they exhibit only minimal internal phase restructuring.

Cognitive Factors Mediate the Relation Between Age and Flight Path Maintenance in General Aviation

2016 ◽  
Vol 6 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Kathleen Van Benthem ◽  
Chris M. Herdman
Keyword(s):  
Cognitive Functioning ◽  
Flight Path ◽  
General Aviation ◽  
Cognitive Factors ◽  
Pilot Performance ◽  
Pilot Error ◽  
Age Related ◽  
And Performance ◽  
Relationship Of ◽  
The Relationship

Abstract. Identifying pilot attributes associated with risk is important, especially in general aviation where pilot error is implicated in most accidents. This research examined the relationship of pilot age, expertise, and cognitive functioning to deviations from an ideal circuit trajectory. In all, 54 pilots, of varying age, flew a Cessna 172 simulator. Cognitive measures were obtained using the CogScreen-AE ( Kay, 1995 ). Older age and lower levels of expertise and cognitive functioning were associated with significantly greater flight path deviations. The relationship between age and performance was fully mediated by a cluster of cognitive factors: speed and working memory, visual attention, and cognitive flexibility. These findings add to the literature showing that age-related changes in cognition may impact pilot performance.

The Association Between Cardio-Ankle Vascular Index and Primary Idiopathic Complete Atrioventricular Block in an Elderly Population

Angiology ◽  
2021 ◽  
pp. 000331972110287
Author(s):  
Turhan Turan ◽  
Faruk Kara ◽  
Selim Kul ◽  
Muhammet Rasit Sayın ◽  
Sinan Sahin ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Atrioventricular Block ◽  
Elderly Population ◽  
Complete Atrioventricular Block ◽  
Age Related ◽  
And Gender ◽  
The Relationship ◽  
Block Frequency ◽  
Complete Atrioventricular ◽  
Relevant Factors

The most common cause of complete atrioventricular block (CAVB) is age-related fibrotic degeneration and is referred to as primary idiopathic complete atrioventricular block (iCAVB). This study aims to investigate the relationship between iCAVB and arterial stiffness using the cardio-ankle vascular index (CAVI). In this study, of 205 CAVB patients, 41 patients with iCAVB implanted with a dual-chamber permanent pacemaker and 40 age- and gender-matched controls were studied. Arterial stiffness was assessed by a VaSera VS-1000 CAVI instrument. The CAVI values of patients with iCAVB were significantly higher compared with the controls (9.63 ± 1.42 vs 8.57 ± 1.12, P < .001). Idiopathic complete atrioventricular block frequency was higher among patients with abnormal CAVI values than those with borderline and normal CAVI ( P = .04). In multivariate analysis, only CAVI was an independent predictor of iCAVB after adjusting for other relevant factors (odds ratio, 2.575; 95% CI [1.390-4.770]; P = .003). The present study demonstrated that CAVI, as a marker of arterial stiffness, was increased among elderly patients with iCAVB. Thus, we provide a possible additional mechanism linking easily measured CAVI with iCAVB.

scholarly journals Plasma angiopoietin-2 is associated with age-related deficits in cognitive sub-scales in Ugandan children following severe malaria

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Benson J. Ouma ◽  
Paul Bangirana ◽  
John M. Ssenkusu ◽  
Dibyadyuti Datta ◽  
Robert O. Opoka ◽  
...  
Keyword(s):  
Severe Malaria ◽  
Parental Education ◽  
Preschool Education ◽  
Kidney Injury ◽  
Malaria Episode ◽  
Enzyme Linked Immunosorbent Assay ◽  
Testing Time ◽  
Age Related ◽  
Angiopoietin 2 ◽  
The Relationship

Abstract Background Elevated angiopoietin-2 (Angpt-2) concentrations are associated with worse overall neurocognitive function in severe malaria survivors, but the specific domains affected have not been elucidated. Methods Ugandan children with severe malaria underwent neurocognitive evaluation a week after hospital discharge and at 6, 12 and 24 months follow-up. The relationship between Angpt-2 concentrations and age-adjusted, cognitive sub-scale z-scores over time were evaluated using linear mixed effects models, adjusting for disease severity (coma, acute kidney injury, number of seizures in hospital) and sociodemographic factors (age, gender, height-for-age z-score, socio-economic status, enrichment in the home environment, parental education, and any preschool education of the child). The Mullen Scales of Early Learning was used in children < 5 years and the Kaufman Assessment Battery for Children 2nd edition was used in children ≥ 5 years of age. Angpt-2 levels were measured on admission plasma samples by enzyme-linked immunosorbent assay. Adjustment for multiple comparisons was conducted using the Benjamini–Hochberg Procedure of False Discovery Rate. Results Increased admission Angpt-2 concentration was associated with worse outcomes in all domains (fine and gross motor, visual reception, receptive and expressive language) in children < 5 years of age at the time of severe malaria episode, and worse simultaneous processing and learning in children < 5 years of age at the time of severe malaria who were tested when ≥ 5 years of age. No association was seen between Angpt-2 levels and cognitive outcomes in children ≥ 5 years at the time of severe malaria episode, but numbers of children and testing time points were lower for children ≥ 5 years at the time of severe malaria episode. Conclusion Elevated Angpt-2 concentration in children with severe malaria is associated with worse outcomes in multiple neurocognitive domains. The relationship between Angpt-2 and worse cognition is evident in children < 5 years of age at the time of severe malaria presentation and in selected domains in older years.

086 Sleep midpoint after job loss predicts breakfast skipping patterns

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A36-A36
Author(s):  
Leah Callovini ◽  
Gaby Gubka ◽  
Candace Mayer ◽  
Darlynn Rojo-Wissar ◽  
David Glickenstein ◽  
...  
Keyword(s):  
Job Loss ◽  
Activity Patterns ◽  
Sleep Onset ◽  
Daily Routine ◽  
Cross Sectional ◽  
Circadian Phase ◽  
Breakfast Skipping ◽  
Occupational Transitions ◽  
The Relationship ◽  
Significant Covariates

Abstract Introduction Few studies have examined circadian phase after job loss, an event that upends daily routine. It is common that a daily routine begins with the consumption of breakfast, and breakfast behavior may contribute to health status in adults. Therefore, we sought to examine whether a later midpoint of sleep was associated with breakfast skipping among adults whose schedules were no longer dictated by employment. Methods Data were obtained from the Assessing Daily Activity Patterns Through Occupational Transitions (ADAPT) study. The sample of 155 participants had involuntarily lost their jobs in the last 90 days. Both cross-sectional and 18-month longitudinal analyses assessed the relationship between sleep midpoint after job loss and current and later breakfast skipping. Assessment periods were 14 days. Sleep was measured via actigraphy, and breakfast skipping was measured via daily diary (1 = had breakfast; 0 = did not have breakfast). The midpoint of sleep was calculated as the circular center based on actigraphy sleep onset and offset times. Results The midpoint of sleep at baseline was negatively associated with breakfast consumption at baseline (B = -.09, SE = .02, p = .000). Also, a later midpoint was associated with breakfast skipping over the next 18 months (estimate = -.08; SE = .02; p = .000). Prospective findings remained significant when adjusting for gender, ethnicity, age, perceived stress, body mass index (BMI), education, and reemployment over time. Education (estimate = 14.26, SE = 6.23, p &lt; .05) and BMI (estimate = -.51, SE = .25, p &lt; .05) were the only significant covariates. No other sleep indices predicted breakfast behavior cross-sectionally or prospectively. Conclusion Consistent with research in adolescents, unemployed adults with a later circadian phase are more likely to skip breakfast more often. Breakfast skipping was also associated with higher BMI. Taken together, these findings provide support for the future testing of sleep/wake scheduling interventions to modify breakfast skipping and potentially mitigate weight gain after job loss. Support (if any) #1R01HL117995-01A1

The relationship between the age of Schistosoma mansoni cercariae and their ability to penetrate and infect the mammalian host

Parasitology ◽  
1983 ◽  
Vol 87 (3) ◽  
pp. 481-492 ◽  
Author(s):  
J. Ruth Lawson ◽  
R. A. Wilson
Keyword(s):  
Schistosoma Mansoni ◽  
Stratum Corneum ◽  
Mass Mortality ◽  
Mammalian Host ◽  
Energy Reserves ◽  
Age Related ◽  
Abdominal Route ◽  
Relationship Of ◽  
The Relationship ◽  
Related Mortality

SummaryThe ability of the cercariae of Schistosoma mansoni to penetrate the tails of mice was shown to remain constant throughout their lives. However, their capacity to establish themselves and then reach maturity decreased as they aged. The abdominal route of penetration produced consistently higher maturation rates than the tail route. Significantly different maturation rates were obtained by modifying the standard tail infection technique. Evidence is presented that age-related mortality of schisto-somula occurs within 24 h of penetration and may be associated with the exhaustion of energy reserves during the penetration of the stratum corneum. The relationship of this age-related mortality to ‘mass mortality’ is discussed.

Spatial memory in Canadian and Indian young and older adults: the effects of age, culture and cultural orientation

2021 ◽  
Author(s):  
Khushi Patel
Keyword(s):  
Older Adults ◽  
Spatial Memory ◽  
Cultural Orientation ◽  
Strategy Use ◽  
Age Related ◽  
Cultural Research ◽  
Cross Cultural Research ◽  
Context Specific ◽  
Performance Gains ◽  
The Relationship

Cross-cultural research suggests that individualistic Americans have a tendency to process focal objects; in contrast, collectivist Asians have a tendency to bind objects and context (Park & Huang, 2010). However, little is known whether the reported cultural differences are moderated by cultural orientation. In light of these results and the well-reported age-related decline in binding abilities, the current study examined cultural and age differences in cultural orientation, spatial memory and strategy use with young and older Canadian and Indian adults. There was little difference between Canadian and Indian participants’ cultural orientation. While cultural orientation did not moderate the relationship between culture and spatial memory, spatial memory and strategy use differed as a function of age. The use of context-specific strategies resulted in performance gains in older adults, however overall older adults had poor spatial memory, with Indian older adults scoring significantly lower than Canadian older adults on the courtyard task.

Shared Neural Circuits for Visuospatial Working Memory and Arithmetic in Children and Adults

2021 ◽  
pp. 1-17
Author(s):  
Anna A. Matejko ◽  
Daniel Ansari
Keyword(s):  
Working Memory ◽  
Brain Activity ◽  
Strong Relationship ◽  
Neural Substrates ◽  
Visuospatial Working Memory ◽  
Age Related ◽  
Arithmetic Networks ◽  
The Right ◽  
The Relationship ◽  
Superior Frontal Sulcus

Abstract Visuospatial working memory (VSWM) plays an important role in arithmetic problem solving, and the relationship between these two skills is thought to change over development. Even though neuroimaging studies have demonstrated that VSWM and arithmetic both recruit frontoparietal networks, inferences about common neural substrates have largely been made by comparisons across studies. Little work has examined how brain activation for VSWM and arithmetic converge within the same participants and whether there are age-related changes in the overlap of these neural networks. In this study, we examined how brain activity for VSWM and arithmetic overlap in 38 children and 26 adults. Although both children and adults recruited the intraparietal sulcus (IPS) for VSWM and arithmetic, children showed more focal activation within the right IPS, whereas adults recruited the bilateral IPS, superior frontal sulcus/middle frontal gyrus, and right insula. A comparison of the two groups revealed that adults recruited a more left-lateralized network of frontoparietal regions for VSWM and arithmetic compared with children. Together, these findings suggest possible neurocognitive mechanisms underlying the strong relationship between VSWM and arithmetic and provide evidence that the association between VSWM and arithmetic networks changes with age.

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